!T
Fp'
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.
I
SYSTEMATIC fiELD STUDY'
OF NO" .EMISSION CONTROL
METHODS FOR UTILITY BOilERS
>.
..
by
William Bartok
Allen R. Crawford
. Gregory J. Piegari
p'repared under .Contract No.' CPA 70-90
December 31, 1971
for the
Office of Air Programs.
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
G RU.4GNOS.71
J
'I
, I...
ESSO RESEARCH AND ENGINEERING COMPANY
Govern ment Research' laboratory'
linden, New Jersey
!
I;
f
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Hi
FOREHORD
This report presents the findings of the Boiler Test Program por-
tion of a '~ystems Study of Nitrogen Oxide Control Methods for Stationary
Sources - Phase II," performed in the Government Research Laboratory of
Esso Research and Engineering Company under the sponsorship of the Office
of Air Programs of the Environmental Protection Agency (Contract No.
CPA 70-90). Dr. William Bartok was the contractor's Project Director,
and Mr. Allen R. Crawford acted as the senior member of the Boiler Test
Program study team. . The findings of other research conducted under this
contract, "Laboratory Studies and Mathematical Modeling of NOx Formation
in Combustion Processes" are presented in a companion report (GRU.3GNOS.71).
. To facilitate the presentation of this study the overall findings
of the Boiler Test Program and the recommendations based thereon have
been ,arranged to precede the detailed discussion of the results.
We wish to acknowledge the cooperation of electric utility con-
cerns, American Electric Power, Consolidated Edison Company, the Los Angeles
Department of Water and Power, Public Service Electric and Gas Company of
New Jersey, and the Tennessee Vally Authority, which made this study possi-
ble. The participation of boiler manufacturer subcontractors, Babcock.&.
Wilcox, Combustion Engineering, Inc., and Foster Wheeler Corp. in. some
o.f the boiler emission tests is also acknowledged. Finally, we wish to
express our appreciation to the Esso Research and Engineering Company
rcscorch technicians, Messrs. L. W. Blanken, T. C. GAydo~, and W..H. Reilly
for their skilled performance of the boiler emission tests.
Mr. Stanley J. Bunas was the EPA Technical Project Officer
during the initial part of this program and Mr. Robert E. Hall was
the Technical Project Officer during the latter part.
. .
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'-
v
T ABLE OF CONTENTS
.
FOREWORD
1.
2.
SUMMARY. . .
INTRODUClION .
. . . . . .
... .0...............
. . . .
. . .
. . .
. . . . .
. . . . .
- .'
. . . .
. . . . . . . . .
OVERALL FINDINGS OF BOILER TEST PROGRAM. .
. . . . . . . .
3.
2.1
Overall Correlations and Conclusions.'
. . . . . .
2.1.1
.2.1.2
2.1.3
2.1.4
2.2
. . . . .
Gas Fired Boilers. . . . . . .
Oil Fired Boilers. . . .
Coal Fired Boners. . . . . .
Overall Conclusions. . . . . .
. . . . . . . .
. . . . .
. . . . .
. . . . . .
. . . . .
......
Emission Factors by Fuel ,
Type and Boiler Firing Method
...............
GENERAL RECOMMENDATIONS FOR
BOILER OPERATORS AND MANUFACTURERS
. . . . .
4.
3.1
3.2
. . . .
Recommendations for Exisiting Boilers
Recommendations for New Boilers. . .
.....
........
BOILER TEST PROGRAM DESIGN AND PROCEDURES.
. . . .
4.1
. . . .
Statistical Field Program Design. . .
.....
4.1.1
4.1.2
4.1. 3
4.2
Boiler Selection. . . . . . . '. . . . . .
Representative Sample Selection. . .
Boiler Test Program Design. . . . .
. . . . .
. . . . .
.. . . . .
Design of Mobile Sampling
and Analytical System. . . . .
. . . . .
4.3.i
4.3.2
Sampling System. . . . . . . . . . . . . . . . . . .
Analytical Instrument Train. .
Integration of Samp1ing-
Analytical System into Mobile Van. . . . . . .
Comparisons of Van Data with
Ot he r Methods. . . . . . . . ... . . . . . . . . . .
. . . . .
4.3 Test Procedures. .
4.2.1
4.2.2
4.2.3
4.2.4
. . . . . .
. . . . . .
. . . . .
Planning the Program with Boiler
Owner-Operators and Mnaufacturers. ;
Conducting the Test Program. . . . .
........
. . . . .
Page
Hi
xi
1
3
3
4
10
14
21
30
34
34
36
37
38
38
41
42
45
45
48
51
55
58
59
60
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r--
I
I
5.
6.
. 6.3
7.
8.
vi
TABLE OF CONTENTS (ContI d.)
CCii.'1.BUSTION HODIFlCATION TECHNIQUES
FOR NO EI-1lSSION CONT ROL. . . . . . . .
x
.8 . . .
. . . . . .
5.1
5.2
5.3
5.4
5.5
5.6
5.7
Load ?eduction . . . . . . . . . . . . . . . . . . . . . . .
Low. Excess Air Firing. . . . . . . . . . . . . . . . .
Staged Combust ion. . . . . . . . . . . . . . . . . . . . . .
Flue Gas Recirculation. . . . . . . . . . . . . . . .
Air Preheat Temperature. . . . . . . . . . . . .
Burner Tilt. . . . . . . . . . . . . . . . . . . . . . . . .
Other Modifications. . . . . . . . . . . . . . . . . .
RESULTS OF THE BOILER TEST PROGRAH. . . .
. . . . . .
6.1
6.2
Boiler Designation and Description. . . . . . . . . . . . .
Individual Emission Results
on Gas Fired Boilers. . . . . . . . . . . . .
. . . .
,6.2.1
6.2.2
6.2.3
Front Wall Gas Fired Boilers. . . . . . . . . .
Horizontally Opposed Gas Fired Boilers. . . . .
Tangential and Vertical Gas-Fired Boilers
Individual Emission Results
on Oil Fired Boilers. . . .
. . . . . . .
. . . .
. . . . .
6.3.1
6.3.2
6.3.3
6.3.4
Front Wall Oil Fired Boilers. . . . . . . . . . . . .
Horizontally Opposed Oil Fi!ed Boilers. . . . . . . .
Tangential Oil Fired Boilers. . . . . . . . . . . . .
Oil Fired Cyc}one Boiler. . . . . . . . . . . .
6.4
Individual Emission Results
on Coal Fired Boilers. . . .
. . . . .
. . . . . . . .
6.4.1
6.4.2
Coal Fired Front Wall Boilers
Coal Fired Horizontally Opposed
and Cyclone Boilers. . . . . .
......
. . . . .
. . . .
. . . . .
6.5
Steam-Side Analyses by Boiler
Manufacturers on Coal Boilers.
. . . . . . .
. . . .
. . . .
RECOHHENDATIONS FOR FlITURE UTILITY BOILER TESTING
. . . . .
REFERENCES. .
. . . . . . .
. . . . .
. . . . .
. . . . . .
'. Pag~
61
61
. 61
62
63
64
64
64
65
66
68
68
79
95
.100
100
109
. 120
126
128
128
133
140
143
148
APPENDIX A. . . . . . . . . . . . .
APPENDLX B. . . . . . . . . .
APPENDIX C. . . . . . . . .
. . . . . . 149
. . . . . . . . . . . . . . . 160
. . . . . . . . '. . . . . . . . 213
ABSTRACT.
. . . . .
. . . .
. 216
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,I
No.
2-1
2-2
2-3
2-4
2,..5
2-6
2-7 .
2-8
2-9
2-10
2-11
I 2-12
...' 2-13
2-14
4-1
4-2
4-3
4-4
4-5
4-6
4-:7
4-8
.4-9
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
vii
LIST OF TABLES
Summary of NOx Emissions from Gas Fired Boilers. . . . . . . .
Linear Regression Analyses of NOx Emissions
from Uncontrolled Gas Fired Boilers. . . . . . . . . . . . . .
Summary of NOx Emissions from Oil Fired Boilers. .
Summary of NOx Emissions from Coal Fired Boilers. . . .
Linear Regression Analyses of NOx Emissions
From Uncontrolled Coal Fired Boilers. . . . . . . . . . . . .
Correlation of Coal Nitrogen Content
wi th NOx Emissions. . . . . . . . . . . . . . . . . . . . . .
Summary of NO Emissions. . . . . . . . . . . . . . . . . . .
Boiler Test P~ogram Summary. . . . . . . . . . . . . . . . . .
Coal Fired Utility Boilers Operating and
Design Problems or Limitations. . . . . . . . . . . . . . . .
Oil Fired Utility Boilers Operating and
Design Problems or Limitations.. . . . . . . . . . . . .
Gas Fired Utility Boilers Operating and
Design Problems and Limitations. . . . . . . . . . . . . . . .
Emission Factors for Gas Fired Boilers. . . . . . . . .'. . .
Emission Factors for Oil Fired Boilers. . . . . . . . . . . .
Emission Factors for Coal Fir.ed Boilers. . . . . . . . . . . .
Boiler.Subpopulations to be Studied. . . . . . . .
Planning the Tes t Program. . . . . . . . . . . . . . .
Continu~us Analytical Instrumen~s in Esso Van. . . . . .
Comparison of Environmetrics Analyzer
'with NDIR (S02 Scrubbing). . . . . . . .
Comparison of Environmetrics Analyzer
with NDIR (No S02 Scrubbing) . . . . . . . . . . . . . . . . .
Comparison of Whittaker Polarographic
NOx and NQIR. NO Instruments. . ". . . . . . . . . .
Comparison of Van'InstrumeI}ts in Boiler - Tests. . '. . . . . . .
Boiler H Analytical Comparisons. . . . . . . . . .
Boiler C Analytical Comparisons. . . . . . . . . . . . .
. . . .
. . . .
Summary of Boiler Design Information. . . . . . '. . . . . . .
Boiler A Experimental Design ~ Gas Fired. . . . .
Summary of Emission Data from Boiler A
(180 MW. Fron t Wall. Gas Fired). . . . . .
BOiler A - Gas Fired, NOx Reduction
Through Combustion Control. . . . ~ . . . . . . . . . .
Boiler A - Gas Fired. Analysis of Variance . . . .
Summary of Emission Data from Boiler B
(80 MW. Front Wall, Gas Fired) . . . . . . .
Boiler B Experimental Design - Fi~ing Gas. . . . . . . . . . .
Boiler B - Gas Fired, NOx Reduction
Through Combustion Control. . . . .
Summary of Emission Data from, Boiler C
(315 MW. Front Wall. Gas Fired). .
. . . .
.....
. . . . .
. . . .
. . . .
~
5
8
11
15
16
18
20
21
23
27-
29
31
32
33
40
42
'49
53
54
55
56
56
'37
67
68
69
70
70
72
73
75
77
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No.
6-10
6-11
6-12
6-13
6-14
6-l4A
6-15
6-16
6-17
6-18
6-19
6-20
6-21
6-22 .
6-23
6-24
6-25
.6-26
6-27
6-28
6-29
6-30
6-31
6-32
6-33
6-34
6-35
6-36
viii
LIST OF TABLES (Cone'd.)
Summary of Emission Data from Boiler D
(350 MWt Horizontally Opposed, Gas Fired). . . . . . . .
Boiler D Experimental Design - Firing Gas.
Boiler D - Gas Fired, NOx Reduction
Through Combustion Control. . . . . . . . . . . . ... . . . .
Summary of Emission Data from Boil~r E
(450 H\.J, Horizontally Opposedt Gas Fired). . . . . . . . . . .
Boiler E - Gas Firedt NOx Reduction
Through Combustion Control. . . . . . . . . . . . . . . . . .
Boiler E - Gas Fired - Analysis of
Variance of NOx Emissions. . . . . . . . . . . .
Summary of Emission Data from Boiler F
(600 HW t Horizontally Opposed, Gas Fired). . . . . . . . . . .
Boiler F - Gas Fired, NOx Reduction
Through Combustion Control. . . . . " . . . . . . . . . . . .
Boiler G Experimental Design - Firing Gas. . . . . . . .
Summary of Emission Data from Boiler G
(220 HW, "All-Wall", Gas Fired). . .
Boiler G - Gas Fired, NOx Reduction
Through Combustion Control. . . . . . . . . . . . . . . . . .
Su~~ary of Emission Data from Boiler H
(320 MW, Tangential, Gas Fired). . . . . . . . . . . . . . . .
Summary of Emission Data from Boiler I
(66 }h~, Ver~icai, G~s Fired) . . . .
. . . .
. . . .
..........
.......
Experimental Design for Boiler A - Firing Oil. . . . . . . . .
Summary of Emission Data from Boil~r A
(180 1'1W, Front Wall, Oil Fired). .. . . . . . . . . . . . . .
Boiler A - Oil Fired, .NOx Reduction
Through Combustion Control. . . . . .
Summary of Emission Data from Boiler B
(82 1'1H, Front Hall, Oil Fired) . . . . . . . . . . . . . . . .
Test Program Design for Boiler B - Firing Oil. . . . . . . . .
Boiler B - Oil Fired, NOx Reduction
Through Combustion Control. . . . . . . . . . . . . . . . . .
Summary of Emission Data from Boiler J
(250 MW, Front Wall, Twin Furnace, Oil Fired). .
Summary of Emission Data from Boiler D
(350 ~n.J, Horizontally Opposed, Oil Fired). . . . . . . .
Test Program Design for Boiler D - Firing Oil. . . . . .
Boiler D - Oil Fired, NOx Emission Reduction
Through Combustion Control. . . . . . . . . . . . . . . . . .
Test Program Design for Boiler E - Firing Oil. . . . . .
Summary of Emission Data from Boiler E
(480 ~~, Horizontally Opposed, Oil Fired).
Boiler E-Oil Fired, NOx Reduction
Through Combustion Cont rol . . . . . . . . . . . . . . . . . .
Summary of Emission .Data from Boiler G
(220 MW, "All-Wall", Oil Fired). . . . . . . . . . . . .
Test Program Design for Boiler G - Firing Oil. . . . . . . . .
.........
. . . .
. . . .
. . .
Page.
78
79
82
83
84
86
87
90
91
92
93
,96
98
100
101
103
104
105
107
108
109
110
11.1
113
H4
116
117
118
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No.
6-37
6-38
6-39
6-40
6-41
6-42
6-43
6-44
6-45,
6-46
6-47
6-48
6-49
6-50
6-51
7-1
,ix
LIST OF TABLES (Cont' d. )
Page
Summary of Emission Data from Boiler H
(320 H\.J, "All-Wall", Oil Fired). . . . . . . . . . . . . . . .
Test Program Design for Boiler H - Firing Oil. . . . . . . . .
Boiler H - Firing Oil - Grand Average
NOx Emissions PPN at 3% 02, Dry Basis. . . . . . . . . . . . .
Summary of Emission Data from Boiler K
(66 N\.J, Tangential, Oil Fired) . . . . . . . . . . . . .
Summary of Emission Data from Boiler L
(400 1'1W, Cyclone, Oil Fired),. . . . . . . . . . . . . . . . .
Summary of Emission Data from Boiler M
(175 N\.J, Front Wall, Coal Fired) . . . . , . . . . . . . . . .
Test Program Design for Boiler M - Firing Coal. . . . . . . .
Summary of Emission Data from Boiler C
(315 N\.J, Front Wall, Coal and Mixed
Coal/Gas Fired)' . . . . . . . . . . . . . . . . . . .
Summary of Emission Data from Boiler F . . . .
(600 HW, Horizontally Opposed , Coal Fired) . . . . . . .
Summary of Emission Data from Boiler N
(820 N\.J, Horizontally Opposed, Coal Fired) . . . . '. . . . . .
Summary of Emission Data from Boiler P ,
(300 HW, Tangential, Coal Fired),. . . . . . . . . . . . . . .
Summary of Emission Data from Boiler Q
'(704 HW, Cyclone, Coal Fired). ~ .. . . . . . . . . . . . . .
Summary of Emission Data from Boiler a
(575 HW, Tangential, Coal Fired) ',' . . . . . . . . . . . ~ .
Test Program Design for BoiJer a - Firing Coal
(NOx Emissions, PPM at 3% 02' Dry Basis. . . ',' . . . . . . .
Test Program Design for Boiler a - Firing ~oal
(Reduced Load Conditions - Staged Firing Patterns) . . . . . .
Number and Types of Utility Boilers to be Tested
in First Year of a Recommended Boiler Test Program, . . . . . 143
121
122
122
125
127
130
131
134
135
136
137
138
139
140
141
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No.
2-1
2-2
2-3
2-4
2-5
2-6
2-7
4-1
~
4-2
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
" 6-10
6-11
6-12
6-13
6-14
Gas Fired Boilers Uncontrolled NOx
Emissions Per Furnace. . . . . . . . . . .
Gas Fired Boilers Uncontrolled NOx
E~ission Per Furnace Firing Wall. . . . . . . . . . . . . . .
Regressions for Gas Fired Boilers
(Uncontrolled NOx Emissions vs.
Gross Load Per Furnace Firing Wall). .
Oil Fired Boilers Uncontrolled NOx
Emissions Per Furnace Firing Wall. . . . . . . . . . . .
Regressions for Oil Fired Boilers
Uncontrolled NOx Emissions vs.
Load Per Furnace Firing Wall. . . . . . . . . .
Coal Fired Boilers Un"controlled NOx
Emissions vs. Gross Load Per Furnace Firing Wall
Correlations of Average Reduction in Uncontrolled
NO Emissions with Reductions in Boiler Load. . . . .
x "
x
LIST OF FIGURES
. . . . .
. . . .
. . . .
. . . . 13
. . . . 17
. . . . 19
Esso Research Transportable Sampling
and Analytical System. . . . . . . . . . . . . . . . . . . . .
Floor Plan of Sampling-Analytical Van. . . . . . . . . . . . .
NOx Emissions from Boiler A
(180 MW, Front Wall, (;a!': Fired). , . . . . . . . . . . .
NOx Emissions from Boiler B
(80 }ru, Front Wall, Gas Fired)
NOx Emissions from Boiler D
(350 MW, Horizontally Opposed, Gas Fired). . . . . . . .
NOx Emissions from Boiler E
(480M1~, Horizontally OppoE~d, Gas Fired).
NOx Emissions from Boiler F
(600 r-ru, Horizontally Opposed, Gas Fired). . . . . . . .
NOx Emissions from Boiler G
(220 HW, "All-Wall", Gas Fired).
NOx Emission from Boiler H
(320 MW, Tangential, Gas Fired).
NOx Emissions from Boiler A
(180 M1~, Front Wall, Oil Fired).
NOx Emissions from Boiler B
(82 MW, Front Wall, Oil Fired) . . ". . . . . . . .
NOx Emissions from Boiler D
(350 }ru, Horizontally Opposed, Oil Fired).
NOx Emissions from Boiler E
(480 r-ru', Horizontally Oppose~, Oil Fir~d).
NOx Emissions from Boiler G
(220 r-1W, "All-Wall", Oil Fired).
NOx' Emissions from Boiler H
(320 MW, Tangential, Oil Fired). . . . . . . . .
NOx Emissions from Boiler M
" (175 r-1W, Front Wall, Coal Fired) . . .
......
. . . .
. . . . .
. . . .
.....
. . . .
. . . . .
. . . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
Page
6
7
9
12
47
52
7J.
74
81
85
89
94
97
102
106
112
115
119
124
132
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xi
SUNHARY
As a major part of Esso's "Systems Study of Nitrogen Oxide
Control Methods for Stationary Sources in Phase II," funded by the EPA
under Contract No. CPA 70-90, a utility boiler field test program was
conducted. The objectives of this study were to determine new or im-
proved NOx emission factors by fossil fuel type and boiler design, and
to assess the scope of applicability of combustion modification tech-
niques for controlling NOx emissions from such installations. In
addition, the concentrations of other combustion flue gas species were
also determined, to evaluate the effect of combustion modification
techniques on the emission of other potential pollutants, such as un-
burned combustibles.
A specially designed mobile sampling-analytical van was
assembled for the purpose of this boiler test program. This system was
equipped with continuous monitoring in~trumentation for the measurement
of NO, NOZ' COZ' 0Z' CO and hydrocarbons, with the later addition of
an SOZ monitor. Probing of the flue gases from boiler duct-work was
~ccomplished by simultaneously withdrawing sample streams from JZ
different locations, varied as dictated by the duct configuration.
Usually, four sample streams compositing the contents of three probes
each were monitored during test runs.
A statistically designed test program was conducted with the
cooperation of utility ownet-operators. Boilers to De tested in the
. program were selected based on fuel type fired, boiler size and design,
and special features of interest to.NOx emission control. The objective
was to make the boilers selected a reasonable "micro-sample" of the.
U. S. boiler population'. Wall-fired, tangentially-fired, cyclone-fired,
and vertically-fired boilers were tested in the program. Althogether,
17 boilers and Z5 boiler-fuel combinations were tested.
The NOZ portion of the total NOx content in the flue gas was
to average five per cent or less, whenever NOZ could be measured. For
data which did not include NOZ measurements, the NOx was calculated as
of the NO measured.
fotmd
test
105%
Major combustion operating parameters investigated included
the variation of boiler load, level of excess air, firing pattern (staged,
"off-stoichiometric", or "biased firing"), flue gas recirculation, burner
tilt, and air preheat temperature. It was found that while NOx e\lll.S~l.On
levels reached very high levels {on the order of 1000 ppm) in large gas
fired boilers, combustion modifications, particularly low excess air
firing and staged air supply resulted in some cases in emission reductions
at full load on the order of 80%. However, even for gas fired boilers,
the degree of effectiveness of combustion modifications varied with
individual boiler characteristics, such as burner design and spacing.
Load reductions resulted in large reductions in NO emissions for gas
fired boilers. x
-------
xii
Similar trends on the effectiveness of combustion modifica-
tions were observed with fuel oil firing, albeit with a lesser degree
of effectiveness. NOx emission reduction from oil firing is less.
responsive to load changes and the application of combustion modifica-
tion t~chniques is somewhat more difficult tpan in gas firing.
In coal firing, promising exploratory data were obtained on
two of the seven coal fired boilers tested. For coal, the key to
NOx reductions (apart from operating under reduced load) appears to be
the firing of. burners with substoichiometric quantities of air, followed by
second stage air injection for the burn-out of combustibles. This was
accomplished in a 175 MW front wall fired boiler and in a 575 MW
tangentially fired boiler with better than 50% reductions in NOx'
operating at 80-85% of full load. Boiler manufacturers participated
in testing three coal fired boilers manufactured by them to assess
the steam-side consequences (i.e., effects on thermal performance,
slagging characteristics, coal in the fly-ash, and other boiler
operability features) of applying combustion modifications. In the
short-term tests conducted in this program, the boiler manufacturers
(Babcock and Wilcox, Combustion Engineering and Foster-Wheeler) did
not find undue problems caused by combustion modifications.
Unburned combustible emissions, Le., CO and hydrocarbons were
found to be very low under base-line boiler operating conditions for all
boilers tested. However, using low excess air firing, the CO levels can
increase sharply, and in fact, set the lower limit on excess air. In
tests where unburned. carbon in the fly ash was measured by boiler ma.nu-
facturers".combus tion modifications (staging with low excessqir firing)
did not resulf in increased carbon in the fly.ash. More detailed testing
will be needed under carefully tontrolled conditions.
. The emission factors established in this study in conjunction
with the overall correlations developed for NO emissions will allow
. x
making better estimates for individual boilers, according to fuel type
fired, boiler size and design.
It is concluded that modification of combustion operating
. conditions offers good promise for the reduction of NO emissions from
utility boilers. Further cooperative testing with boi!er owner- .
operators and manufacturers are required to optimize and demonstrate
the general applicability of these techniq.ues to the control of NOx
emissions from gas and oil fired installations and to establish their
complete potential for coal fired boilers.
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l~
INTRODUCTION
In Phase I of a "Systems Study of Nitrogen Oxide Control Methods,,(l)
sponsored by NAPCA (Contract No. PH 22-68-55), Esso Research and Engineering'
Company characterized the stationary NOx emission problem in th~ U.S.,
assessed existing and potential control technology on the basis of cost-
effectiven~ss, and developed a comprehensive set of 5-year R&D plans f0r
stationary NOx emission control. In addition, a first-generation mathe-
matical model of NOx formation in gas-fired combustion processes was formu-
lated, and knowledge gaps pertinent to the NOx control problem were defined.
The Phase I'study established that stationary NOx emissions
predominantly result from fossil fuel combustion processes. Electric
utility boilers were found to represent the largest stationary NOx emission
source category. Combustion modification techniques have been identified
as, potentially the most attractive for stationary NOx control because
of their relative simplicity and potentially low cost. However, the scope
of applicability and degree of effectiveness of combustion modification
techniques had to be defined on a systematlc basis for the variety of
combustion installations which emit NO . .
x
As part of EPA's program on stationary NOx emission control, based
on the recommendations of the Phase I NOx systems study, Esso Research and
Engineering Company initiated further 'studies on this air.pollution control
problem under Contract CPA 70-90. . .
The present Phase II portion,of the NOx systems study had the
following major objectives:
(a)
A statistically designed systematic study was designed ,
and conducted on utility boilers. One objective of this field
study was to obtain new or improved emission factors based
on parametrit variations of fuel type, boiler size and design, and
operating features. Another major objective of this systematic
study (hereafter referred to as the "Boiler Test Program"),
was to evaluate the effects of limited changes in design and
. operating parameters on NOx emissions from existing powe~
plant boilers. A representative sample of the U. S. boiler
population was selected for these tests, in some of which
boiler manufacturers also participated to assess the effects
of operating changes on boiler performance.
(b)
The first-generation mathematical model of NOx forma-
. tion and decomposition in combustion processes was
extended. Additional kinetic information was used, and
the model was programmed to incorporate the combustion of
fuel oil droplets and coal particles. Mixi~g effects were
. '
-------
-.2.-
If
simulated by programming a "macromixtng" model to improve
the model's approximation of actual combustion conditions.
The predictions of this mo~el were compared with actual
experimental and test data. Further development of the
model was found necessary for its use to guide research
on combustion modification techniques for reducing NOX
emissions from existing equipment and to predict good
combustor design.
(c)
Laboratory studies were conducted to define basic
factors affecting nitrogen oxide formation in the
combustion of fossil fuels. Flame k:i.netics, the con-
centration of potential intermediate species and the
relative role of bound nitrogen in the fuel w~re
investigated. These laboratory studies were designed
to provide a better understanding of the complex mechanism
of NOx formation in combustion processes and to provide in-
formation for the development of the NOx mathematical model.
(d)
Major modifications deemed necessary for. the control
of NOx and other pollutant emissions were outlined in
cooperation with boiler operators and boiler manufacturers.
The recommended modifications are discussed in this report.
This reIJort preseJ?ts the detailed findings?f the Boiler Test Program.
Work performed on laboratory-scale combustion phenomena and mathematical
modeling.is ,discussed in a separate. companion report (GRU, 3GNOS. 71).' .
. .
-------
- 3 -
2.
OvERALL FINDING'S OF BOILER TES'i' PROCRAI1
The NOx emission data obtained in our Boiler Test Program
were analyzed with the objective of developing overall correlations on
all of the boilers tested with gas, oil, and coal firing. As discussed
in this section, it was possible to arrive at statistically sJgnificant
overall correlations applicable to all (or most) boilers tested within
a given fuel category, regardless of the type of firing. Furthermore,
the relationship between NOx emissions and boiler load was established
according to fuel type, covering again all types of firing methods.
These overall correlations are useful from several standpoints.
First, they provide a common basis for rationalizing the NOx emission
data measured in testing boilers of different size and type, fired with
different fuels, and subjected to combustion operating changes for NOx
emission control. Second, they can be used in conjunction with the NOx
emission factors developed based on the results of this study for making
definitely improved emission estimates for boilers for which the emission
levels have not been determined. Third, and perhaps most important,
these overall correlations can be used for planning on a rational basis
future field emission tests aimed at optimizing combustion control methods
for different types of utility boilers and operations.
The overall correlations and conclusions resulting from this
study, concerning the control of ' NO x emissions from utility boilers,
are discussed 'in this section including emission factors for NO and
° " 'h . C, 1 . ' . " ..1' ' ..1 X .
C. FurtL er sect~ons o~ t~l:'S report ~~J..J. u:LSCUSS our ~~COn1l1h~nuat~0l1S
for boiler operators and manufacturers on emission controi, the details of
this study and our recommendations' OR future boiler emission field testing
studies.
2.1
Overall Correlations and Conclusions
In section 6 the individ~al boiler test results are
for gas, oil and coal fuels. In this section we will analyze
for all boilers tested according to fuel type, and then these
be compared for all three fuels.
F:-esented
the results
resul ts will
Summary tables of NOx emissions have been prepared for boilers
firing' gas, oil, and coal, respectively. Each bqiler is identified in
these tables by its code letter, size (MW generating capacity), and type
of firing. Uncontrolled NOx emissions and per cent reductions for each
of the combustion control methods applied are shown corresponding to the
boiler load levels tested in the experimental program. '
-------
- 4 -
2.1.1
Gas Fired Boilers
As shown in Table 2-1, NOx emissions from uncontrolled gas
fired 'boilers operated at full load varied between 155 ppm and 992 ppm
(corrected to 3% 02' dry basis), or an average of 589 ppm. Although at
full load there is some relationship between rated boiler size and NOx
emission level (ppm NOx = 381 + 0.718 MW; r = 0.47), a better and more
logical relationship exists between NOx emissions and rated furnace size
(ppm NOx = 297 + 1.715 (MW per furnace); r = 0.61). Thus, about 37% of
the variation in NOx emissions about t~e average value of 589 ppm is
"explained" by the variation in furnace load. Figure 2-1 is a plot of
uncontrolled NOx emissions vs. gross load per furnace for the gas fired
boilers tested. Data points representing the individual furn~ces are
connected by lines so that the reduction in.NOx emissions with r.eduction
in load 'for each boiler can be seen.
Figure 2-1 indicates a second relationship--the NOx emissions
from the front wall fired boilers tested change more with load changes
than those from the horizontally opposed boilers, and average about
twice the NOx emissions for equivalent furnace load. This relationship
suggests that an improved correlation may exist between NOx emissions
and load per furnace firing wall. The number of furnace firing walls
. for .front wall, opposed wall, and .tangentially fired boilers having
,single furnaces are 1, 2, and 4, respectively. Figure 2-2 is a plot of
NOx emissions vs. load in MW per furnace firing wall. The regression
equation for full load, uncontrolled firing is ppm NOx = 187 + 4.0 (MW
per furnace firing wall) (r = 0.72). If Boiler G ("all-wall" firing) is
omitted, the regression equation becomes ppm NO~ = 28 + 5.57 (~M per furnace
firing wall) (r = 0.89). The unusual configuration of Boiler G ("all-wall" ,
with division wall) results in six furnace firing walls.
Figure 2-2 also indicates the change in uncontrolled NOx
emissions with change in load for each gas fired boiler tested. With
the exception of the "all-wa 11" fired Boiler G, all of the NOx data
fall within a relatively narrow band when plotted on this basis.
Regression analysis indicates that about 80% of the variation in NOx
emissions is related to,or explained by the variation in the gross load
per gas firing furnace wall. Tabie 2-2 summarizes the regression
equations developed for uncontrolled, gas fired boilers according to
type of firing. (Vertical firing from a single row of burners was
assumed to be equivalent to a single furnace firing wall.)
-------
TABLE 2-1
SUMMARY CJII NO EMISSIONS FRQI CAS FIRED BOILERS
~
80t ler Full Load tond 1 t lona Intermediate Load Conditions Low Load Condit 1008
Uncontrolled 1. Reduct ton in N Uncontrolled 1 '%. Reduct ion in N Uncant ra lied '1. Reduce Ion tn N
Type Cross NO an hI tOOIl LEo< CroBs NO D'Qhs tons LEA Gr08' NO Do 1881009 LEA
Code Size of Loed p~ or 31. 02' and "NO "Fu 11 Load ppo',\ at 31. 02. and "NO "Full Load p~ at 31. 02' and "NO "Full
Letter (M\I\ Firt" (Mil) Dry 8..1. LEo< Stoaln Staaln PortsU FCR control' (HW\ Dry 8..10 . iLF~ tulna Stoalna Ports" FCR ontrol n (1'1\1) Ory 1\801. LEo< StaRtn Sta~lna Ports" FCR onerol"
(4)
A (5) 180 F1J 180 390 15 49 60 -- -- 60 120 230 118 42 52 -- -- 52 70 116 7 30 43 -- --. 43
8 80 F1J 82 497 15 24 37 -- -- 37 50 240 I~: 17 -- -- -- -- 20 90 -- -- 28 -- -- 28
C (5\ 315 F\I 315 992 6 -- -- -- -- -- 223 768 -- 33 -- -- 33 186 515 .. -- -- -- -- --
A1:erege 192 F1J 192 626 13 37 48 -- -- 48 131 413 -24 30 42 -- -- 42 92 240 7 30 36 -- h 36.
D 350 HO 350 946 21 50 62 47 -- 77 -- -. -- -- -- -. -- -- 150 341 -- 66 -- 39 20 81
E (1)(5) 480 HO 480 736 9 -- -- 38 -- 81 360 610 6 -- -- 53 -- 57 250 363 9 -- -- 32- -- 70
F (5) 600 HO 559 570 16 -- -- -- -- -- 410 335 19 -- -- -- -- -- 325 253 61 53 70 -- -- 10
C (5\ 220 A\I 220 675 2J 58 60 -- -- 60 190 550 21 35 48 .. -- 48 125 313 25 58 66 -- -- 66
,.verage 412 HO 402 732 17 54 61 42 -- 73 320 498 15 35 48 53 -- 52 212 318 32 59 68 36 20 72
H (2) (5) 320 T 320 34D -- -- -- -- -- 66 240 2lD -. -- -- -- 60 65 -. -- -- -- -- -- -- --
I 13\ 66 V 66 155 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Grand Ave 290 ALL 286 589 16 45 54 42 -- 64 228 423 19 31 44 53 60 51 161 284 26 52 52 36 20 60
V1
(I) Deto oupplled by boller operator.
(2) tlet. supplied by boiler operator. Separate effects of individual controls 'not !De. silTed.
(3) Insufficient date for estL'Mttng effects of cornbu8tion controls.
(4) Type of firing codes: f\I. front wall, HO. horizontally opposed, AW..11 vall, T. tangential.
(5) 1\I1n furNice or division v.ll in lingle furnace.
v . vertical.
-------
1000
900
800
700
U)
"ii)
ro
OJ
>. '600
...
c
..
N
0 '
~ 500
.('1)
.oj
ro
E
Co
Co
.. 400
x
a
:2:
300
-'6 '-
Figure 2.;.1
GAS FIRED BOILERS
UNCONTROLLED NO EMISSIONS PER FURNACE
x
200
Code Type of Firing Boilers
o Front Wall A,B,C
100 0 Har, Opposed D,E,F
\J "AII Wall" G
6.' Tangential H
<> Vertical I
o
0 100 200 300
Gross Load per Furnace, 'MW
-------
1000
\I)
\I)
~
a:J
>. 600
...
"0
..
N
o
~
('t)
...
~
E
a.
a. 400
..
x
o
2
"300
"- 7 -
"Figure 2-2
"GAS FIRED BOILERS
UNCONTROLLED NOx EMISSIONS PER
.FURNACE FIRING WALL
900
800
7QO
500
Code Type of Firing
200
o
o
Broken line Y
segments are L.::1
extrapolations. \1
Front Wall
Hor. Opposed
"AII Wall"
Tangential
Ver.tical
o
o
50 75 100 125
Gross Load per Furnace Firing Wall, MW
150
25
Boilers
A,B,C
D,E,F
G
H
I
175
-------
-'S'-
TABLE 2-2
LINEAR REG~:SSION k~ALYSES OF NOx EMISSIONS
FROM L~CONTROLLED GAS FIRED BOILERS
r
i
r Boiler Data
~-
,
-..---.
'-"-'--TOYf~~--'---'''lN~.':'--~f''l- .,," ,m.. . _. ---...----......---. -.. . '- -'-I Corre- Is td.
, ,'Data! I lation - Devi-
Firin 1points! Regression Equations(lI) ~ coet£. ~ation
I: ,. I .
FW , 9 hpm NO = -118 + 7.01 Hlv/FFW t 0.97(C~ 74:
HO ! 8, !ppm NO:= -43 + 5.31 M\v/FJ:lv ! 0.S3(bj) 143:
FW and HO ! 17 ppm NO = -70 + 5.95 M\v/FF\.J O..9l(c 117 i
FW, HO, T i 19 ppm NOx= -17 + 5.51 MW/F~v 0.90(c. 118:
i FW, HO, T:~ v.J 20 ppm NO: = -36 + 5.61. ,,'/FFW . O. 89( c~ 123 i
! All Types ~d 23 ppm NOx =--ll~_~~ 35- MW~~~...- ...?:_~~-~~l.--~.~~j
;A,B,C
:D,E,F.
;
~A,B,C,D,E,F
.
iA,B,C,D,E,F,H
I
,
!A,B,C,D,E,F,H,I
! {\., B,D, E,F ',G ,H, I
~_-""'-'-==-......o----~
(a)
(b)
( c)
ppm NOx corrected to 3% 02' dry basis; MW/FFi.J = 'load per furnace firing wall, MW.
Significant at the 0.1% confidence level.
Significant at the 1'7. level.
Figure 2-3 presents the plot of the regression equations listed in Table 2-2
for front wall 'and' opposed wall, and for the combination of front wall,
O~P?~~J. \:J£111, 8tH} Lc.l~g~iltidlly fired L0il~rs. l-."s expcct;::d, thE: s.tandard
deviations of NOx emissions are siz~ble, but these correlations are highly
significant and should be valuable for the purpose of making emission
estimates.
-In summary, for gas fired hoilers operated at full load, in
six out of the nine boilers tested it was possible to reduce NO emissions
by an average of 64%.. The use of low excess air- with staged fi~ing
accounted for the bulk of this reduction. At intermediate (2/3) to
, low (1/2) loads, the application of all control methods tested reduced
NOx emissions by 50 to 60% compared with uncontrolled NOx emissions at
these load levels. The use of existing "NO-ports" and flue gas
recirculation equipment was also found to be effe~tive for the few
boilers where this type of equipment was available.
-------
1000
900
800
700
If)
If)
~
DJ . 600
>-
,..
. C).
..
N
0..--
~ 500
~
.....
IU
E
.0.
0.
400
..
x
o
z
300
200
100
o
o
- 9 -
Figure 2-3
REGRESSIONS FOR GAS FIRED BOILERS
.... ....
. t .
f/~
't:
QJ
8'
~
*
Insufficient data
for meaningful correlation.
25
50 75 . 100 125
Gross Load per Furnace Firing Wall, MW
150
175
-------
- 10 -
2.1. 2
Oi1 Fired Boilers
. Table 2-~ presents a summary.of NOx emissions measured from
the nine oil fired 00ilers tested. Uncontrolled NOx emissions at full
load varied bet\-leen 200 ppm and 580 ppm, \-lith an average of 360 ppm NOx'
compared to a range between 155 ppm and 990 ppm, and an average of about
590 ppm NOx for gas fired boilers. The relationship bet\oleen uncontrolled
NO emissions and gross load in NW per furnace firing wall at full load is
pp~ NOx = 228 + 1.59 ~v/F~v (r=0.59) for all nine oil fired boilers tested,
and ppm NO.. = 237 + 1.324 MW/FFW (r=O.SO) when the front wall, horizontally
opposed, and tangential oil fired boilers only are included in the correlation.
These correlations are not as good as the corresponding correlation
coefficients of r,= 0.72 and r = 0.89 for gas firing. Variation in fuel
oil nitrogen content, viscosity, preheat temperature, spray pattern as
well as the method of spray atomization, burrier design characteristics,
and air-fuel mixing patterns probably account for a large port.ion of these
variations in NOx emissions from oil fired boilers. Our limited testing
indicated a average increase of 44 ppm NOx per 0.1% combined nitrogen
in the fuel for fuel oils containing combined nitrogen in the range of
0.3 to 0.6 wt.%. This corresponds to an average conversion of about 30%
of the fuel nitrogen into NOx. However, adjusting the NOx emission data
for fuel nitrogen content had only a marginal effect on the regression
analyses, except for tangentially fired boilers.
In Figure 2-4 a plot of NOx emissions from uncontrolled oil
fired boilers operating over a range of load levels is presented. Comparison
of the data in Figure 2-2 with those in Figure 2-4 for gas and oil firing
respectively, shows the NOx emissions from oil fired boilers exhibtt,
considerably mere vn~i~ticn tha~ those f~o~ gdS ri~~J boil~r~. In
addition, NOx emissions from oil fired boilers decrease at a rate less
than proportional to the corresponding fractional load reductions, while
NOx emissions from gas fired boilers decrease at a higher fractional rate
than the corresponding load reductions. In Figure 2-5, the regression lines
of uncontrolled NO emissions vs. load per furnace firing wall are plottcQ
, x
for oil fired boilers.
The NO emission reduction achieved through the application
x
of combustion controls for each of the oil fired boilers tested are also
given in Table 2-3. Use of all available control methods resulted in
45% to 60% reduction in NOx for front wall fired boilers at full load,
and from 30% to 50% reduction at about 2/3 load. Low excess air firing,
staging, and flue air recirculation were all successful in reducin,g NOx
emission either separately or in combination to varying degrees of
effectiveness. Only one of the front-wall fired boilers tested (J) was'
equipped with flue gas recirculation into the'windbox.
One of the two oil fired, horizontally opposed wall
boilers tested developed process control equipment problems during
testing, and therefore, could not be tested with, all possible combustion
control methods. With other front wall oil fired boilers a 38% reduction
in NOx w~s obtained at full load, and 55% at about 1/2 load through a
combination of low excess air firing with staging, and the use of the
available ''NO-ports''. The "all-wall" fired unit tested was not equipped
-------
TABLE 2-3..
SIJI1HARY OF NOK !'HISSI ON~; PRCII OIL FIRED BOILERS
,
'J.'"
~~ .,-
1~ ~
Boiler Full Loed Cond 1 t 10n8 Intem~.!dl..e LOild Conditions Low Load .Cond it 10ns
Uncont ro lIed ~ Reduct ion 10 N UnControlled 1. Reduct ton in N Uncontrolled "L Reduct 100 in N
Type Cros8 NOx eo 188 {008, LEA Cros8 NOx euls81ona. LEA Grols NO IJDlaalona, LEA
Code Size of Loed ppn 8t 3t 02' and ''NO "Full Loed ppn at 3t 02' and "NO "Full toed p~ at 3t 02' .nd ''NO ''Pull
Letter (MW) Fir!n. IHw) Drv eaa!. LEA tOR In. Stooln. Ports" FCR ~ontrol" (HW) Drv eaolo 1~~ f
-------
600
500
If)
If)
rtS
c:)
>- 400
~
(:)
..
N
o
~ 300_,
('t'\
....,
rtS
E
a. .
'a. 200
..
x
o
:2:
- 12 -
Figure 2-4
OIL FIRED BOI LERS
UNCONTROLLED NOx EMISSIONS
, PER FURNACE FIRING WALL
Letters inside symbols
denote boiler codes.
25
75
50
100
Gross Load per Furnace Firing Wall, MW
, ..,~t.
Code type of firing Boilers
o Front Wall A,B,J
o Hor.Opposed D,E
V All Wall G
6
125
1-50
H,K
175 .
-------
. - 13 -
;~
I .
I
Figure 2- 5
REGRESSIONS FOR OIL FIRED BOILERS
UNCONTROLLED NOx EMI SSIONS VS. LOAD
.. PER FURNACE FIRING WALL
.
600 .
500
VI
VI
II:!
CD
>- 400
...
c
..
N
a
~ 300
C'l"I
. ......
II:!
E
0.
0. 200
..
x
o
:2
o
o
25
50 75 100 125
Gross Load per Furnace Firing Wall, MW
150
175
-------
- 'Iii -
with "big" oil guns which \"ould have allO\.'ed staging at full load; however,
at about 80'% of full load, staged firin'g with 10\01 overall excess air
resulted in a 44% reduction' in NO , compared to uncontrolled NO emissions'
at th is load leve 1. x x,
The 320 HI;! tangential boiler was tested at only 2/3 load so
that staging could be accomplished, since "big" oil guns were not available
for supplying additional fuel to the operating burners. Even th.ough NO
emissions were relatively low on an uncontrolled basis (215 ppm), the x
use of low excess air with staged firing and with flue gas recirculation
resulted -?pf'!"oe
-------
TAJILE 2-4'
SUMMARY OF NOA EMISSIONS'FROK COAL FIRED BOILERS
Int,irmediete Load Conditions
Low Load Conditions
Uncontrolled
NOx EmlRsions,
ppin at 37. 02'
Dry Bos is
R~ductjon In NO ~
StagIng LEA ~Full~..J
+ Control'.
Staging ,
Uncontr/) Dry Ba. is
'H 175 FW
: c(2) 315 FW" 275 1490 '
j --
I F(2) 600 HO 563 838 i ::
1 NP> BOO HO 77B 905 I
i 0(2) 575 !
! p(2) T I
300 T 300 568 ! 27
! ,
Q 700 CY 665 1170
GRAND 495 ALL . 516 994 ; 27
AV
50
39
42
52
, 278
I
42
702
, '
-------
- 16 -
bottom of the furnace, and a layer .of insulating tile \.]as placed along
the fur!1ace walls from the floor to an elevation above the top row of
burners. This design results in high furnace flame temperatures, and
relatively slO\.] heat absorptiori in the lower furnace (maintaining the
slag molten), and therefore, promotes high NOx emission levels.
The linear regression analyses of the uncontrolled NOx emissions
from coal fired boilers are summarized in Table 2-5 at all load levels
tested, c8rresponding to the data of Figure 2-6. Again, eliminating the
data on Boiler C, the correlations improve significantly for both full
load and variable load test conditions. Since the assignment of three
as the number of furnace firing walls for the cyclone boiler Q was
established somewhat arbitrarily, a regression analysis (number 5)
was also made without including the data on Boilers Q and C for comparison
with the regression analysis (number 4 in Table 2-5) on all coal fired
boile~s, except C. Both regressions are highly significan~ with over
80,? of the variations in uncontrolled NOx emissions explained by, or
related to the single parameter, load per furnace firing wall in megawatts,
over the entire load range tested. While as expected, the standard
deviations in ppm NOx are quite large, correlations (2, 4, and 5) in
Table 2-5 should be useful for emission estimate purposes.
TABLE 2-5
LINEAR REGRESSION ANALYSES OF NOx
EMISSIONS FROM u~CONTROLLED COAL FIRED BOILERS
t I ' Correta- I
-
No. of tion Std. .
!
Data E~uations (a) Coeff. Deviat ion i
Boiler Data Points Regression r ppm
I'. All boilers at full " I
load only" 5 ppm NOx= 569 '+ 2. 76 MWIFFW I .45 361
I I -r
? All boilers at full f
;
load (Boiler C 293 + 3.65 MW/FFW! .96 (b)' I j
omitted) 4 ppm NO = 88 I
x I
3. All boilers at all I 0 . 57 (b) I
loads 15 ppm NO = 423 + 3.49 MW/FFW 1 I 299
i
x I I
4. All boilers at all
loads (Boiler C I 0.94 (c)
12 ppm NO = 252 + 3.82 MW/FFW I 89
omitted) ,
x \
5. All boiler at all ;
"I
loads, (Boilers C J 0.9l(c)
and Q omitted) 10 ppm NOx= 256 + 3.68 MW/FFW j 93
t
(a)
(b)
(c)
ppm NOx corrected to 3% 02' dry basis, ~/FF\~ = load pe,r furnace fixing wall, MW.
~ignificant at the 5% confidence ievel.
significant at the 0.1% confidence level.
-------
1600
1400
1200
II)
II)
(';$.
(Q 1000
>.
'"-
Q
..
N
o
~
('/"\
....
11:1
E
0.
0.
..
x
o
:2::
- 17 -
Figure 2-6
COAL FIRED BOILERS
UNCONTROLLED NOx EMISSIONS VS. GROSS LOAD
PER FURNACE FIRING WALL
BOO
600
Type of Firing
o Front Wall
D Opposed Wall
~ Tangential. .
\J Cyclone
Letters inside symbols
denote boiler codes.
Broken line segments
are extra olations.
250 300
Gr~ss Load per Furnace Firing Wall, MW
200
i
0
0 50 100 150 200
350
-------
- 18 -
As shO\-m in Table 2-4, Boiler H, a front-wa 11 fired boiler and
Boiler 0, S tangentially fired boiler, were tested with a wide range of
combustion controls at about 80/0 of full load. In both of these boilers
it was found possible to significantly reduce NOx emissions through the
application of staged firing \>"ith lo\>" overall excess air. None of the
other five b0ilcrs could be tested under what amo~nts to proper staging
oper~tions. Potential slagging problems were the chief reason why the
builer 0perators refrained [rom the use at 1m, excess air, 0. from combining
low ~:«(".: is a ic \:ith staged fir ing on these coa1. dred boilers. A minor
excepticn was Boiler P~ a tangentially fired boiler which was operated
for short periods of time ,vith 1ml1 excess air firing, resulting in reduced
NOx emissions.
An analysis was made to det~rmine whether the limited. data on
the bound nitrogen content of the coal fuels fired could be correlated
with the measured emissions. Unlike the data obtained on two oil fired
boilers, for which different fuel oils could be incorporated into the
experimental program designs, so that the effect of varying nitrogen
cOntent on NOx emissions could be measured independently of load, excess
air and other parameters, in coal firing the coal fuels varied according-
to what was available during the test programs. A regression equation
(ppm NOx c 291 + 3.67 ~M/FB~, r c 0.95) of uncontrolled NOx emissions
measured at maximum load vs. load per furnace firing wall (including all
boilers except C) was used to predict NOx emissions without taking into
account the effect of fuel nitrogen content. The differ~nces between
the actual measured uncontrolled NOx emissions and these"predicted"
values were correl~ted with the average nitrogen conteni of the coal
fuel fired in each of the boilers tested, as shO\.Jn in Table 5-6. The
regre.ssion coefficient of 884 suggests an 88, ppm increase in NOx emissions
per 0.1% increase in fuel nit'rogen content for 1.15 to 1.40 wt. %
. nitrogen content coals. Considerably more' data are needed to define
this relationship as the above correlation is not precise, and assumes
that all of the increase in NOx' can be attriuuted to the increase in
coal nitrogen content (equivalent to all average coal nitrogen conversion
of about 50% into NOx)' without taking into 'account other combustion variables.
TABLE 2-6
CORR8-ATION OF COAL NITROGEN CONTENT WITH NO
. . . x
EHISS IONS
660
838
905
405
568
1170
I 'Predicted" (Actual- Coal
HW NOx Emis-~dicted" Nitrogen
! FFW ~SionsL..e'pm,. NO 6) ! Content
!
i 70 547 j '113 1.33
;141) 808 ; 30 1.38
~ 195; 1006 \ -101 . 1.17
59 i 508 . -103 i 1.25
: 75; 566 2' 1.33
222 1106 64 1.30
"Predicted"
6
IBOilerj
I M t
! F ;
! ~
! N
°
p
Q
Highest Actual
Load I ppm NOx
Fired iEmissions
I
~
140
563 '
)
778 . ;
470 j
300
665
34
78
-108
-37
34
7
* "Predicted" ppm NOx = 291 + 3.67 w..l/FFW, r = 0.95.
** .lIpredicted"6= -1142 + 884 (N content, wt.%). i: == 0.74.
-------
100
"'C
IU
0
-1
::I 80
I..L..
....
IU
II)
s::::
0
II) 60
II)
E
W
x
0
2: 4"0
"'C
(1)
0
....
....
!::
0 20
(.)
s::::
::>
......
0
~
o
o
10 .
Figure 2-7
CORRELATION OF AVERAGE REDUCTIONS IN UNCONTROLLED
NO EMISSIONS WITH RED"UCTIONS IN BOILER LOAD
x
20
30
50
60
40
80
70
90
Gross Boiler Load, as % of Full Load
o
"'C
IU
o
-1
20 -
::I
I..L..
..:..
ro
II)
s::::
40 .~
11)"
II)
E
W
....
\0
X I
60 ~
s::::
s::::
o
.....
(.)
80 ::I
"'C
(1)
e::::
~
100
100
-------
TABLE 2-7
SUMMARY OF NO . EMISSIONS
1I.
Combustion Opecating Modification and Furnace Load(l)
Type (2) 70 Reduction in NOx Emission
Fuel of Low Exc. Air Staging' LEA + Stag inS! r Flue Gas Rec. "Fu 11" (3)
, Fired FirinS! Full Int. Low Full Int. Lo',ol Full Int. Low i Full T Int. T,ow Full Tn t. I T.ow
GAS FW 13 24 7 37 30 30 48 42 36 I I 48 42 I 36
-- -- !
j I '
I . ! ; I i I
' ! I I . I I
HO ' 17 15 32 54 35 59 61 48 68 -- i -- 20 ! 73 I 52 72
i I ' j ! I ' I 1
' I I 1 I I
i j ; I I I I i ! !
: I I ! I ! ! J
T -- -- i -- -- 1 -- -- I -- -- ! -- -- i 60 i -- ; 66 . 65 -- \
i ! I r
. t ' I ! ' ~ I I
I I '
! , I , (
. ! ~ , I t i r i I .
i ' ; \ I i i
ALL 16 19 26 \ 45 i 31 52 54 44 52 I 60 ! 20 ! .64 ~ 51 60
I : ( t I i i -- !
, (Average) I : ! ! ( !
. j I ! ! , !
, i i J i ! i i f !
f I ! I I ! j '
, i ' J
'--4 ~ : '
., ! i I J I I i
. i ' ' !
' ' I
FW N
; 0
! i ; I
HO 10 16 34 . 34 44 ! 42 ~ -- 38 35 : 55 ,
. I
i \ ! I
i 28 22 ! . ! 59 '
T -- 17 45 -- 10 13 -- , I
I ; . ;
; j
I
! I
. I '
:
i j I 38
' 19 19 18 30 22 38 37 32 28 23 47 42
i . ! . j .
i j , ! ...
. j !
,
I (
i
I \ ~
t !,
COAL FW 14 -- 40 ' 55 I -- 60
I I '
!
i \ 1
HO -- : --
. ! i :
I I
T 27 18 -_ ! i 39 i -- 50 42 50 42
!
I
27 ' ! 52 42 : 42
ALL 1.7 -- 39 ' -- I 52 -- 55
i . !
(Average)' ! .i
I'
(1) Furnace load: "Full" == 85%-105%, "In termed ia te" == 60%-85%, Low == 50%-60% of rating.
(2) Type of firing: FW = Front Wall, HO = Horizontally Opposed, T == Tangential.
(3) "Full control": combination of techniques achievable on boilers tested.
\ OIL
I
.
I
i
,
I
I :
I ALL \
" (AVerage)!
. I
i
I
I
;
;
!
i 20
i
! 47
I
I
I
! 34
I
,
,
1
\
I
I
!--
"
; --'
i
i
I --
I
,
27
20
28 I
,
I
\
12 !
29
) 20
i 39
,
;
i 35
!
,
1--
! 21
\
I
. --
50
46
41
: 21
32
31
-------
- 21 -
2.1.4
Overall Concl Hsions .
As discussed in detail in sections 6 and 2.1, extensive
experience has been obtained. and significant accomplishments hav~ be~n
made during this study in testing utility boilers for NO. emission control
by combustion modifications. A total of 277 test runs w~re made on 17
boilers (25 boiler-fuel combinations) as shown below in Table 2-8.
TABLE 2-8
BOILER' TEST PROGRAM SU}~~Y
(Number of Boilers and Test Runs by Fuel and Type of Firing)
T
I
clone !Vertical
Fuel Fired
Front
Wall
Hor izon ta lly
° osed
"All-Wall"
I
i
Coal I 2-24 2-10 2-35 1-6
Gas 1 3-30 2-23 1-14 I 1-8
I: Oil i 3-52 2-36 1-13 2-13 1- 5
Coal & Gas 11-6 j"
I I
Tota 1 I 9-112 6-69 2-26 ! 5-55 2-11
1-4
1-4
Tota 1
7-75
8-79
9-117
1-6
.125-277 i
. Significant red~ctions of NOx eruissioll~ \,ert= ol>tain",d on many of the "boilers
tested. The remaining ~ajor problems and. limitations have been defined
for each of the three types of fossi~ fuel.
Under base line operating conditions, i.e., without control, NOx
emissions from medium and 'large gas fired boilers at full load ranged from
about 400 ppm to a high of almost 1000 ppm for front wall and horizontally
opposed fired boilers (all concentrations corrected to 3% 02, dry basis).
A medium sized tangential fired boiler had an NOx emission level of only
330 ppm on an uncontrolled basis. The application of combustion modifica-
tions to gas fired boilers was successful in reducing NOx emissions by 40%
to 80% at full load and by over 90% at reduced loads. Combustion modifications
on wall fired boilers included the application of low excess a~r, staged
combustion, and use of NO ports, where available. These results indicate
that effecrive NOx emission control can be applied to gas fired boil~rs through
operationally feasible combustion modification techniques.
-------
- 22 -
. NO emissions from uncontrolled oil fired boilers were generally
lower (300-560 ppm) than NOx emissions. from uncontrolled gas fired boilers
of the same design and size. However. in most cases, the application of
combustion modifications to oil fired boilers could not reduce NO emissions
x
to as low levels as achieved on the same boilers whel1 firing gas. Part of
this difference is probably due to the bound nitrogen content of oil
fuels. although ~ther factors, particularly droplet atomization, vaporiza-
tion and combustion characteristics may be equally important. Therefore,
additional research is needed to sort out these effects. On a front wall
. fired boiler equipped with flue gas recirculation into the wind box. the
combination of low excess air. staged firing and flue gas recirculation re-
suited in about 60% reduction of NOx' The maximum NOx reduction with the
combination of low excess air and staged combustion was about 45%. Additional
research is needed on selected boilers to determine the optimum combination
of controls where a variety of control options are possible.
Coal fired boilers presented the greatest difficulty in applying
combustion control. Full load. uncontrolled NOx emissions from large size.
coal fired boilers ranged from 800 to about 1500 ppm in wall and cyclone
fired boilers, while large tangentially fired.boilers emitted about one-half
of these levels. Of the seven coal fired boilers tested. combustion
modifications resulting in substantially reduced NOx emissions could be
applied in only two of these units. In both cases (a front wall and a
corner tired boiler) low excess air combined with staged firing (resulting
in a loss in boiler rating of about 15/0 to 2070) resulted in NOx emission
reduction of over 50%, compared with full load conditions without controi.
The other five boilers could not be tested at sufficiently low excess air
levels to expect much improvement in NOx emissions. In some cases, this
~lt!S due to cbseTved. r221 sli:ibglr;g prvblc::ms, ami in others, a reluctauce
of boiler operators to r~sk potential problems even for a limited period
of test time. Additional field testing of a carefully selected sample
of coal fired utility boilers is required to define the scope of applicability
.of combustion modification techniques on a re~listic basis.
The Boiler Test Program resulted in the definition of a number
of problem areas which currently limit the control of NOx emissions from
coal fired boilers, and to a much lesser extent, from oil and gas fired
boilers. Tables 2-9. 2-10 and 2-11 summarize our experience on the
operating, design, and fuel quality problems, and on the limitations
associated with each combustion control technique. The code letters
indicate our assessment of the relative severity of the problem from
"no effect" (D) to "major problem or limitation" (A). If insufficien~
experience had been obtained to properly rank the problem area, a
question mark was used in these tables. Some vf the major problems will
be discussed below in further detaiL Since coal firing enta-ils the
largest problem area, the features of Table 2-9 will be discussed before
those of Tables 2-10 and 2-11.
In coal fir-ing, improper slagging conditions can be a major operating
problem severely limiting the use of low excess air and staged firing for the
reduction or NOx emissions. For example, dry bottom furnaces require a
buildup of dry slag that tends to form balls that roll off the furnace
surfaces for normal gravity -collection and removal. If, however, local
temperatures become so high that the normally dry slag becomes molten, it may
-------
- '23 -
TABLE 2-9
COAL FIRED UTILITY BOILERS
OPERATING Mom DESIGN PROBLEHS OR LH1ITATIONS
.
Comb us tion Control Technique
Low \;'1 ue Gas Load I .1 Ai r
Excess Staged Reci r- Reduc- Burner,Damper
Air Firing ulation tion, Tilt i Setting
A. Operating Prob lems & Limits
1. Slagging A-C B ? B ? ?
2. Steam Temperature Control A-C B A-C A A B
3. Furnace Wall Temp. Limits B C B C B B
4. Flame Impingement on Furna ce Wa 11 A A ? + C B
5. Flame Impingement - Burner A B ? D C B
6. Corrosion - Furnace Walls & Tubes ? ? ?-C D D. ?
7. Corrosion - Ducts, Air Heater + ?-D ?-C B D D
8. High CO and Combustible Emissions A A ? D D B
9. H~gh Particulate Emissions ? ? ? ? ? ?
10.. Reduced Operating Flexibility B .B ? A B B
11. Reduced Safety Margin B C C D D C
12. High Operating Cost + A-C ? A D D
13. Flame Stability B B ?-A D D .' t
B. "Design;' Instruu~nt or .
. Control Limitations
1. Lack of Flue Gas Recirc. Facility D D A D' D D
2. Lack of "NO-Ports" D B D D D D
3. Lack of Auto. Damper Controls A A C C D A
4. Lack of 02 Instrument A A A D D B
5. Lack of CO, H.C. and Combus tible A A A D .O B
Instruments
6. Lack of Automatic Control System A C C C C C
7. Burner Design ? ? ? D A D
C. Fuel Quality Limitations
1. High N - Content B D B D D D
2. Poor Slagging Characteristics A A ? A A ?
3. High Iron Pyrites Content A A ? B B B
4. High Sulfur Content C C ? D D ?
5. Low Heating Value Fuel B B ? D 0 0
..
,~~
'.
f
i
I
I
I
A - Major Problem or Limitation
B - Moderate Problem or Limitation
C - Minor Prohlem or Limitation
D - No Problem or Limitation
? - Extent of Problem or Limitation
+ - ContrQl Technique Aids Problem
Unknown
-------
- 24.-
run down furnace walls in rivulets and the~ freeze on furnace bottom'sur-
faces necessitatiog a shutdown for expensive slag removal. Wet bottom fur-
naces, on the other hand, require uniformly high temperatures so that the'
slag remains sufficiently fluid to flow easily to the slag taps. These condi-
tions are aggravated by the use of coals with slagging characteristics dif-
ferent than called for by the furnace design.
Steam temperature control may limit the full use of combustion
control techniques to reduce NO emissions if insufficient temperature C011-
x
trol flexibility is available. Flue gas recirculation, steam or water at-
temperation, flue gas dampers, and burner tilt are common methods of super-
heat and reheat temperature control. However, most current boilers are
limited by design to the use of one or two of these methods of temperature
control. Thus, the use of low excess air, staged combustion, maximum flue
gas recirculation, and combinations of these techniques may cause.. changes
in boiler heat distribution that can only be partially compensated for by
the other temperature controls. Further, detailed experimentation is needed
to find the optimum combination of combustion modifications at full and re-
duced loads for significant NOx reductions with adequate boiler steam tem-
perature control.
Flame impingement on furnace walls must be avoided to limit cor-
rosion and excessive local temperatures at ~he water tubes. Thus, the use
of low excess air may necessitate the readjustment of primary and secondary
air damper damper positions, burner tilt (if available) position, and' .
'impeller position, to avoid long flames tha t impinge on furnace walls.
.This emphasizes again the necessity of visual inspection of the furnace,
along with adequatQ experimentation in order to fully exploit the operating
flexibility inherent to each boiler design. .
The definition of corrosion }1roplems within the furnace area,
such as tub~ wall wastage, requires long-term testing with combustion con-
trol techniques for full understanding and quantification. Our Boiler Test
Program emphasized short, intensive, multifactor experimental designs in
order to maximize the information obtained within the relatively brief pe-
riods of time that could be allocated to each boiler. Based on this expe-
rience, it will be possible to plan longer tests at the most effective set
of .combustion control combinations. The proper adjustment of burners fir-
ing near the walls so that combustion modifications can be applied to the
bulk of the burners should' be helpful in avoiding furnace corrosion problems.
Thus, the "~ailoring" of combustion modifications to meet tnp. requi t"pmpnts
of individual boiler designs and fuel qualities are required for optimizing
NOx emission control.
Problems caused by condensation of corrosive ~aterials due to
'formation of sulfur trioxide can be reduced by low excess air and staged
firing. However, a practical operating limitation of the use of low excess
air or the combinatl.on of low excess air with staged firing is the potentially
excessive formation of CO, and other combustibles. Proper instrumentation,
coupled with good maintenance of equipment, and adjustment of individual
burners ar~ necessary in order to obtain the full benefi.t of these control
techniques. Improper 'operations of one or two burners can completely offset
the effectiveness of low excess air and staged firing for NO control.
x
. .
-------
-.25
. The quantitative effect of combustion control techniques on par-
ticulate formation has not been adequately characterized in coal fired
boilers. Consequently, additional research is needed in order to assess
the possible advantages and disadvantages of combustion modifications for
NOx emission reduction on the emission of particulates.
It is readily apparent that some reduction in operating flexibil-
ity results from the full use of combustion modifications for NO control.
x
For example, the use of low excess air calls for close attention to indivi-
dual burner operation; this means good maintenance practices and frequent
measurement and observation of furnace conditions. \fhere burner tilt af-
fects NOx emissions, its use for steam temperature control is restricted.
The use of flue gas recirculation and air damper settings for NOx reduction
also limit their use for steam temperature control. However, the reduction
of NO emissions and improved fuel economy due to low excess air firing
x
offer sufficient incentives that some loss of operating flexibility may be-
come acceptable. Properly instrumented boilers, operated under sound main-
tenance and operating practices, should reduce this potential problem area
to a minimum, without significantly limiting the application of combustion
modification techniques.' .
Obviously, safe operating practices must be maintained while em-
ploying combustion modification techniques for NOx emission control. Flame
stability can be impaired with low excess air, staged firing and excessive
flue gas recirculation. However, unsafe conditions are well known and can
be avoided while operating to reduce NOx if good design, operating, and main-
tenance practices are employed. .
The effect of combustion modification techniques on operating
costs is generally well understood. The use of low excess air reduces op-
erating costs, while reduction in load increases operating costs per unit
output. Generally, tbe use of staged firing results in reduced load, and
therefore, increased unit operating costs. However, where the fuel burning
capacity of individual burners can be increased, staged firing may resuit
in reduced NOx emissions with little reduction in load. Burner tilt and
air damper settings should have little effect on operating costs, while ad-
ditional research is needed on the economic effect of flue gas recircula-
tion.
Design, instrument and control limitations may reduce the applica-
tion of combustion modification techniques, particularly on older boilers.
Thus, most coal fired boilers lack facilities for flue gas recirculation
into the windbox, and we know of no coal burning boilers with "NO-ports"
for two-stage combustion. .However, where flue gas recirculation into the
.furnace for temperature control is available, it may be possible to add
additional duct-work for recirculation into the windbox at relatively low
cost. Also, the secondary air ports in some coal fired boilers can be ad-
justed with s.taged coal firing to obtain mos.t of the advantages of staged
firing with little or no additional equipment costs. Our experience indi-
cates the qecessity for adequate instruments for continuous measurement of
-------
- 26' -
the level of excess air a~d incompletely burned CO or other combustibles
in order to use low excess air and staged combustion techniques with full
effectiveness. It should also be'noted that non-base loaded boilers which
are required to change load frequently would be able to employ combustion
control a higher proportion of operating time if automatic equipment and
controls become available for changing air damper settings, turning'
individual burners on and off, etc. Finally, the effect of burne'r design
in conjunction 'vith combustion modification techniques is not completely
understood, and theretore, should be further investigated.
Coal quality can play an important role in the potential
scope of applicability of combustion modification techniques. The im-
portance of matching coal slagging characteristics' with furnace d~sign para-
meters have been discussed earlier. Use of fuels containing' high levels of
iron pyrites can severely restrict the application of low ~xcess air and
staged firing in cyclone and other wet bottom furnaces due to possible metal
corrosion. Additional field testing is needed in order to determine how to
avoid corrosion problems and slagging difficulties while employing effec-
. tive NOx reduction with combustion modification techniques such as flue gas
recirculation, low""excess air and staged firing., In' the case of cyclone
boilers, recirculation directly into the cyclones may be required. The role
of nitrogen in the coal fuel must be studied in detail from the standpoint
of its impact on combustion modifications for NOxemission control.
The application of combustion modification techniques for NO
,emission reduction on oil fired boilers'presents considerably fewer pr3blems
and unknown areas'than for coal fired boilers. For example, problems asso-
ciated with slagging, and ireil pyrites in the iuel are virtually eliminated.
In addition, the measurement and cont~ol of fuel to air ratios on individual
burners is considerably easier in oil firing than in coal firing, thus sim-
plifying the application of low excess air and staged firing.
Table 2-10 summarizes the problems and limitations associated with
NO emission control for oil fired boilers in a similar manner as Table 2-1.0
dO~s for coal fired boilers. The more important limitations and problems for
t~is equipment category are discussed briefly below. .'
The formation of smoke or haze is often a major limitation in ob-
taining the full benefit of applying low excess air in oil fired boilers.
However, the design and operating problems associated with low excess air
are well known. To achieve low excess air without increasing haze or smoke
generation, it is necessary to have adequate windbox pressures for good air
control, well-designed burner throats and impellers for proper air turbu-
lence, well-matched patterns of oil atomization with air flow, balanced
burners for proper air/fuel ratio on each burner, and good instrumenta-
tion to keep the air/fuel ratio under control as the demand for steam
change$. Important advantages of low excess air firing in addition to lower
NO emissions are increased boiler efficiency and reduced low-temperature
. x
corros ion.
s upp ly
Staged firing accomplished by providing air ports above the top
row of burners, and modified staged firing or introducing air only through
some burners in conjunction with low excess air have consistently resulted in
significantly reduc~d NOx emissions from oil fired boilers. The use of extra
fuel capacity oil guns have enabled some boilers to maintain full load op-
ation with staged firing. Thus, proper design and operating practices necessary
, .
-------
- 27 -
TABLE 2-10
OIL FIRED UTILITY BOILERS
OPERATING AND DESIGN PROBLErlS OR LIMITATIONS
Combustion Control Techniques
Low IFlue Gas[ Load \ Air
,
Excess Staged Recir- Reduc- I Burne r Damper
Air Firing:culation tion I Tilt Settin~
:
A. Operating Problems and Limits
L Haze or Smoke Formation A B C D D B
2. Steam Temperature Control A C A D A C
3. Furnace Wall Temp. Limits C A A D D C
4. Flame Impingement - Furnace Walls B B ? D D C
5. Flame Stability C B A D D C
6. Corrosion - Furnace Walls & Tub es C C D D D D
7. Corrosion - Ducts, Air Heater C. C D D D D
8. High CO, H.C. and Combustible A B B D " D A
Emiss ions i '
9. Hi~h Particulate Emissions A ? ? D D ?
10; Reduced Operating Flexibility B B B A B C
11. Reduced Safety Margin A B C D D C
12. High Operating' Costs + B C A D D
B. Design, ,Instrument or
,Control Limitation I I I
L Lack of Flue Gas Recirculation D D A D D D
Facilities I i I
2. Lack of "NO-Ports" D I A i D D D D
3. Lack of Auto. Damper Controls A A C D D D
4. Lack of ,CO, H.C. or Combustible A A B D D C
Instruments \ I
5. Lack of Automatic Control System B C I C C C C
6. Burner Design ? C I D D A D
I
7. Fuel Control to Burners A A C D D D'
C. Fuel Quality Limitations
L High N-Content B D B D D D
2. High S-Content C C C D 'D D
3. High Metals/Ash Content D D D D D D
A - Major Problem'or Limitation
B Moderate Problem or Limitation
C - Minor Problem or Limitation
D - No Problem or Limitation
? - Extent of Problem or Limitation
+ - Control 'l'echnique Aids Problem
j
Unknown
-------
- 28 -
for low excess air firing generally'eliminate the potential problems
associated with staged firing. The problem of determining the proper
pattern of burner firing at various loads in order to obtain low NOx
emissions without excessive CO and hydrocarbon formation, or temperature
control problems can be solved by detailed, well-planned statistical
experimental programs on each class of boilers.
Limited field testing of flue gas recirculation into the
combustion zone has proven effective for NOx reduction on oil fired boilers.
Howeve~, additional research is needed to determine the best combination
of low NOx e:nissions ,,,ithout causing problems of temperature control, or
high CO and particulate emission levels. '
, Because of the alternative combustion modification techniques
available for the effective reduction of NOx emissions, the use of load
reduction with its high operating cost penalty appears to be relatively
unattractive for NOx control for oil fired boilers. Assuming the availability
of proper instrumentation and control equipment, the major problem of NOx
reduction from oil fired boilers is to det~rmine the optimum comhination of
available combustion control techniques that effectively reduce NOx at each
load without aggravating potential operating problems. Again, the problem of
NOx emissions due to fuel nitrogenoxidatiun must be assessed.
, The application of combustion modification techniques for NOx
emission reduction from gas fired boilers presents fewer problem,areas or
limitations than either oil or coal firing. Our evaluations are summarized
in Table 2-11 for this equipment category. Experience on many boilers has
shown that lm~ NOx e~icsic~s can be obtained un well-maintained and operated
boilers through the application of the proper combination of combustion
modification te'chniques. However, the demonstration of efficient, planned
multifactor experimental programs to rapidly achieve optimum NOx reduction
within the inherent boiler flexibility is needed to take full advantage of
potential improvements. In addition, research is needed in order to determine
the most effective burner design for wall and tangentially fired boilers.
-------
.. ",
'- 29 -
TABLE 2-1'1
GAS FIRED UTILITY BOILERS
OPERATING AND DESIGN PROBLEMS AND I.INITATIONS
A.
Operating Proh1ems or Limits
1.
2.
3.
4.
s.
6.
7.
8.
Haze .Formation
Steam Temperature Control
Furnace Wall Temp. Limits
Flame Impingement on Furnace Walls
Flame Stability
Corrosion - Furnace Walls & Tubes
Corrosion - Ducts, Air Heater
High CO, H.C. and Combustible
Emissions
High Particuiate Emissions
Reduced Operating Flexibility
Reduced Safety Margin
High Operating.Costs
9.
10.
11.
12.
"
B:
Design, Instrument or
Control Limitation
1.
Lack of Flue Gas Recirculation
Facilities
Lack of "NO-Ports"
Lack of Auto. Damper Controls
Lack of CO, H.C. or Combustible
Ins trumen ts
Lack of Automatic Control System
Burner Design
Fuel Control to Burners
2.
3.
4.
s.
6.
7.
C.
Fuel Quality Limitations
A - Major Problem or Limitation.
B - Moderate Problem or Limitation
C Minor Problem or Limitation'
D - No Problem or Limitation
? - Extent of Problem or Limitation
+ - Control Technique Aids Problem
Low
Excess Staged
Air Firing
Combustion Control Techniques
Flue Gafi Load j
Recir- ,Red uc- ' Burne r
cuJ.?tiorl ~,~
-------
- 30 -
'2.2
Emission Factors by Fuel
Type and Boiler Firing Hcthod
Nit rogen oxide and carbon monoxide emission factors corresponding
to uncontrolled, base-line operating conditions, were calculated for each
boiler tested. These emission factors ~re summarized in Tables 2-12, 2-13,
and 2-14, respectively, for gas, oil, and coal fired utility boilers tested
in our. program. No attempt was made to calculate corresponding hydrocarbon
emission factors, since as discussed earlier, the measurable levels of
. hydrocarbon emissions were negligibly sma~l.
Inspection of the emission factor data, expr~ssed both as parts
per million (corrected to 3% oxygen in the dry flue gas), and quantity of
NOx eh~ressed as equivalent N02 per unit energy input (calculated both as
lb. N02 per 106 Btu and gm. N02 per 106 caluries), indicates a wide varia-
tion of NOx emission factors depending on fuel type and method of firing.
In general, coal firing results in the highest NOx emission factors, but the
distinction between gas and oil firing is blurred, because of the strong
influence of boiler design, size, firing intensity, bound nitrogen con-
tent of the fuel oils, and other factors.
Within a given category of boiler firing design, tangential fir-
ing appears to yield the lowest emission factors, as expected, based on
prior information (1). The high intensity cyclone firing design is at the
other extreme, resUlting in high values of the NOx emission factors. Car-
bqn monoxide emissions, under normal operating conditions, were found to be
low, without, exception. This is reflected by the very low values of the CO
emission factors tabulated. However. using modified combustion operating
conditions for NOx control, particularly with low excess air firing or with
the combination of staged firing with overall low excess air, the CO emis-
sions may increase sharply when the excess'air is reduced below a critical
.level. As discussed in Sections 6 and 2.1 of this report, the critical level
,of excess air depends on the ruel type and boiler design and operating
characteristics. The emission factors ~~termined in this study in conjunc-
tion with the overall correlations of NOx emissions discussed in Section 2.1,
will be useful for obtaining better emission estimates for individual boilers
'than those which coul,n be C'alculated based on "average" va lues available
prior to this study (.!..' ~).
-------
TABLE 2-12
EMISSION FACTORS FOR GAS FIRED BOILERS
Boiler Emission Factor
Size and NO". CO
..
Load(l) Type of ppm, at 3% °2, 1b/106 BTU gm/106 ca1. ppm, at 3% 02, 1b/106 BTU . 6
Code MW. Firing(2) Drv Basis (3) (3) Dry Basis gm/10 ca1.
Small
-
B 80F FW 497 0.65 1.16 52 0.043 0.074
I 66F V 155 0.20 0.36 12 0.010 0.017
Medium
A 180F FW 1390 0.51 0.92 14 0.011 0.020
C 315F FW 992 1.29 2.32 (6) (6) (6)
i G 22"OF AW 675 0.88 1.58 . 14 0.012 0.020 i
I H' t 320F T 340 0.44 0.79 175 0.145 0.249 I
1, D ~ 355F HO 946 (515) (4) 1.23 2.21 86 (67) (4) 0.068 0.122
! i
, 0.028-0.571
~ Large
I
~ E 480F HO 736 (140) (5) 0.96 1. 73 20-400 0.016-0.33
. F 600F- HO 1570 0.74 1.33 8 0.006 0.011 I
:
I
4",.)
~
(3)
(4 )
(5 )
(6)
(1) Load: F = Full Load, R = ,Reduced Load
(2) Type of Firing: FW = Front Wall
V = Vertical
AW = All Wall
T = Tangential
HO = Horizontally Opposed
Expressed as equivalent N02 .
Using "NO-ports"
Using staged combustion
Not ava ilable
-------
TABI.E 2-13
EMISSION. FACTORS FOR OIL FIRED BOILERS
..
Boiler Emission Factor
- CO
NO ;
Size and x
-
1b/106 BTU 6
Load(l) Type of .ppm, at 3% 02' gm/10 ca1. ppm, at 3% 02' Ib/106 BTU gm/106 ca1.
Code HW . Firing (2) Dry Basis (3) (3) Dry Basis
-
I Small tBa
B .t 82F FW 0.78 1.41 64 0.052 0.094
K :: 66F T 1203 .0.27 0.49 28 0.023 0.041
2
,
,
. Medium ,!
. i
I
. ~ 367
A . i 180F FW 0.50 0.89 19 0.016 0.028
J I 250F FW ~ 360 0.49 0.87 30 0.025 0.044 .
$
D ~ 349F HO 1457 (300) (4) 0.62 1.11 66 0.055 0.097
G 1 220F AW (235 0.32 0.57 19 0.015 0.028
H .'. 216R T p61 0.22 0.39 13 0.011 0.019
~
! r
~ it I
1 Large ~
\
, ' ! i
I. E. . 359F HO '~ 246 (200) (4) 0.33 0.60 14 0.017 0.021 f
; 415F cr ~ 530 0.72 1.29 6 0.005 0.009
L ,.
. ~
. ..
W
N
(1) Load: F= Full Load, R = Reduced Load
(2) Type of Firing: FW = Front Wall
HO = Horizontally Opposed
AW = All Wall
T = Tangential
CY = Cyclone
(3) Expressed as equivalent N02
(4) Using "NO-ports" .
-------
TABLE 2-14
EMISSION FACTORS FOR COAL FIRED BOILERS
Boiler Emission Factor
-
NO. CO
- x
Size (1) Type of ppm, at 3% 02 1b/106 BTU 6 ppm, at 3% 02
gm/ lOcaL lb/l06 BT~ 6
Code MW Firing (2) Dry Basis (3) (3) Dry Basis gm/IO cal.
Small
-
~
M l40R FW 660 0.90 ! 1.63 97 0.081 0.146
.'
Medium
C 275F . FW 1490 2.04 3.68 (4) (4) (4)
p 300F T 568 0.78 1.40 25 0.022 0.038
Large
F 563F HO 838 1.15 ! 2.07 20 0.017 0.030
N 780F ~ HO 905 1.24 2.24 (4) (4) (4)
o 400R i T 405 0.55 1.00 20 0.017 0.030
I I
Q 670F i CY 1170 1.60 2.89 (4) (4) (4)
I ,
'.
,w
w
(1) Load: F= Full Load, R = Reduc~d Load
(2) Type of Firing: FW = Front Wall
T = Tangential
HO = Horizontally Opposed
CY ::= Cyclone
(3) Expressed as equivalent'N02
(4) Not available
-------
- 34 -
3. GENE&\L RECOMMENDATIONS FOR
BOILER OPE&\TORS k~D ~~UFACTURERS
Further detailed stlldies are tC'.juired in close coopera!:.ion
with hoiler operator~ and r.1[!nufacturers to optimize and demonstrate
combustion control ",cthods for NO p.mjsslons' from utility boilers. In
x .
the ca~e of g.1S and oil fired LI:1its, field demonstrations are
needed on a sustained basis, to allow the optimization of combustion
modification techniques found effective in this study, and to evaluate
the long-term consequences of implementing such techniques on boiler
operability and ste~m-side pcrfor~an~c. For coal fired utility boilers,
the promising results obt<3ined by combinini.; staged. combusti.or~ with 10\';
excess air firing should be follo;'icd up '...'ith further, mo~-e detailed
exploration of this and other techniques. As the state-of-the-art and
experience reaches a level comparable to that \-lhich e~:ists now for. gc.S
and oil fired boilers, demonstration of the best technology on coal fired
utility boilers will be required, including t~e thorough assessment cf
slagging, corrosion, flame and potential safety problems.
KnoHledge availahle at present on combustion modifications
for NOx control. is insufficient for generating detailed, step-by-step
instructions of use to boiler operators and boiler manufacturers \_'110
'wish"to opcrat~ or build low NOy emitting units. Still, it is po~sible
. 'to formulate general recommendations and to suggest rational approaches
to the problem based on the experience gained by us in these
. EPA-sponsored investigations, and by others working in this rapidly
evolving field. The general recommendations or guidelines are b~st
separat~d into two categories:
1-
2.
Existing boilers
New boilers
Our recommendations are outlined in the following sections of this report.
3.1
Recommendations for Existing Boilers
To achieve acceptable levels of NOy emissions, a step-by-step
approach is recommended for modifying the operation, and possibly some
design features of existing boilers. It must be remembered that the
applicability of general principles will be different for each boiler,
depending on its size, fossil fuel type and quality, firing method and
intensity, and peculiarities of the baiJpr cipsi~'1. I~ thi.s context, th~
overall correlations presented in Section 2.1 will be oJ use.
As a first step, the operator should catalogue (preferably
with the aid of the manufacturer) the load demand on the boiler, boiler
design
-------
- 35 -
f)
Hhat load reduction 15 permissible without affecting
nc.t\vork 51'S tcm pcr formance and rescrve cap.3c ity?
The boiler should be operated at the 1m,'est acceptable
load level, particularly for gas fired units '",hich respond
more sharply to ioad reductions than \Vith other types of
firing. ,For the difficult-ta-control cyclone boilers load
reducti.on r.1
-------
- 36 - ,
o
Can flue gases be recirculated into the primary combustion
zone? If the boiler is cquipp.cd \.:ith appropriate ~as
handling equipment to the air supply to recirculate flue gases
used for steam temperature control, this fe.1ture should be
exploited. If flue gas recirculation is available but only
into the bottom of the furnace, the option of insta lling
additional ducting, fans, filters, etc., should be considered.
In addition to the above, all "minor" operating changes
discussed in this rerort should be carefully consi.dered. Once the most
appropriate combination of combustion operating conditions and equipment
modifications are selected [or the particular boiler(s) to be controlled,
standi1rd modes of operation should be established by step\.;ise implementation of
the changes. Naturally, the procedures adopted for One boiler should
be applicable \-Jith minimal changes to similar units.
3.2
Recommendations for New Boilers
Obviously, both the boiler operator and the manufacturer \-Jill
have more latitude to bring into line ne\-Jly designed boilers than existing
ones 'from 'the crnissibn standpoint. To meet existing or anticipated
performance standards, ~hich in fact may become more stringent as nC\-J
technology becomes available, \-JC feel that it \wuld be wise to provide
. for .sufficient boiler flexibility in the desibn phase to satisfy such future
needs. Th is may be accomplished \.; ithout incurring prohibitive costs by.
cOf1sidering the follo~~ing £...:::~.:.:,:.s i.n L:le speciri~aLi(;n of a new boiler.
.
Provide for staged combustion and low excess air firing
by individual control of fuel ai1d air flow to burners.
Install oversized burners to allow for changing burner
patterns in staging.
.
Design the unit with "NO-ports" or other overfire air
capabilities and a sufficiently high secondary air supply
capacity to penetrate into the flame zone.
.
Install flue gas recirculation facilities into the primary
combustion ZOne.
e
Consider designing oversized furnaces, particularly for
gas fired units which respond well to this type of change,
and for cyclone boilers which await the development of novel
designs (c.g., recirculation into or staging in the cyclone)
to control NO.. emissions by other means.
....
.
In~tall monitoring instrumentation for NOX) unburned
combustibles and other pollutants to see \olhethcr the
cbntrol steps are indeed effective and the boiler ~omplies
with regulations.
-------
- 37 - .
4.
BOILER TEST PROGRAN DESIGN AND PROCEDURES
A top priority reco~~endation of our Phase I NOx Stationary
NOx Systems study(l> was to conduct a systematic investigation of the
feasibility of applying combustion modification techniques to the control
of NOx emissions from utility boilers, and to obtain reliable emission
factor data on this class of equipment. .
Limited experience exclusively with gas and oil fired boilers,
has shown the attractive potential of NOx emission control using
combustion modification techniques such as low. excess air firing, two-
stage combustion, flue gas recirculation, changing burner spacing and
location and combination of such techniques(l). It was also known that
certain firing types. such as tangential anrl vertical firing, result
in inherently lower NOx emissions than other types, e.g., wall firing.
The purpose of our Boiler Test Program was to systematically
measure NOx and other combustion gas emissions from utility
boilers, based on a statistically designed program incorporating the variation
of fuel type, boiler design and size, and combustion operating variables.
.Using this approach, we designed the test program to provide information
on the scope of applicability of combustion modification techniques for
NOx control, as limited by the operability of the boilers teste~ and to
define problem areas and equipment design changes required for optimizing
the use of the control techniques investigated.
Particular &ttEn~i0n ~as p~,jd to ccnsi~er2tion9 of 6ther
undesirable emissions or boiler operability problems resulting from
the practice of NOx control techniques. Sampling and analysis on a
real-time basis to yield statistically meaningful information was
another consideration. Also, the cooperation of electric utility
companies had to be obtained for emi2~ion tests on their equipment,
based on the variation of combup~lon operating conditions within the
limits of flexibility of the equipment~ Finally, for a few carefully
selected coal fired utility boilers, the participation of the boiler
manufacturers was obtained to provide guidance on the limits of
operability of the boilers, and to assess the steam-side boiler
performance consequences of operating changes made for NOx emission control.
This section of the report presents our approach to the
statistically d~signed Boiler Test Program in which 17 boilers were
tested, including the description of the mobile sampling-analytical
system equipped with multiple probes and, continuous gas analyzers.
-------
- 38 -
4.1
Statistical Field Program Design .
There are three major sampling problem areas in designing field
test programs that require the use of sound statigtical principles for
their efficient solution. First is the problem of selecting a properly
sized, representative sample of boilers. for testing from all United States
utility boilers. A second problem occurs in selecting the number, location
and period of time to obtain flue gas samples from each boiler. Finally,
the operating conditions for each test run, as well as the order and number
. of test runs conducted on each boiler presents a problem of statistical
experimental design. This section describes each of these problems
with the corresponding statistical principles involved in its solut~on.
4.1.1
Boiler Selection
Selecting a proper representative sample of United States' boilers
for a limited NOx emission field test program is a particularly difficult
problem because of the wide diversity of boilers in use, and the high
dependence of NO emission rates on boiler design, operatin~ and fuel
factors. x
There are about 3,000 utility boilers currently in use in the
United ~tates. These boilers vary considerably in age, design, size and
fuel usage since boilers are custom-designed to economically meet the specific
requirements of individual customers. Fuel availability, quality and cost, as
well as changing boiler design and construction technology, in addition to other
economic factors,have all contributed to the diversity of utility boilers
in use.
The conceptual steps involved in statistically designing the
selection of boilers were:
(1)
(2)
Determine the total. number of boil~rs to be tested considering
limitations of cost, time, anc.other factors.
Determine the major boiler design, fuel and operating factors
for classification of boilers into strata or sub-populations.
Allocate the total sample of boilers to the sub-populations in
an optimum manner.
Select individual boilers within each sub-population to minimize
travel, administrative and other costs.
(3)
(4)
To plan the Boiler Test Program, the detailed information on boiler
operating and design features and emissions obtained through the Steam-
~lectric Plant Survey of our Phase I Stationary NO Study(l) was analyzed.
The total number of boiler-fuel combination to be 1ested was limited
by the seven-month period available for the test program. Allowing one
day each for system set up and breakdown, plus an average of three
days required for testing (12 to 24 test runs), resulted in about one
week of time available for testing a boiler-fuel combination. However,
wherever practical, boilers capable of burning more than one fuel were
selected, resulting in saving two days for each additional fuel as
well as giving better precision in comparing fuels within boiler
types. An average of three days testing per boiler-fuel combination
was the minimum time required to explore adequately NOx emission
-------
- 39 -
reduction through confuustion control on most boilers. Allowing for
tr~vel time, boiler operating problems, and the required analytical
train maintenance, resulted in a maximum of about 20 to 30 boiler-fuel'
combinations which could be tested in an optimum s.i.tuation dur.ing the
contractual period. .
Classification of boilers into subpopulations or strata has many
advantages. Emission data is assured for each prime subdivision of the
entire population of boilers. Improved precision of the total estimated
boiler emissions is obtained through stratified sampling. The complex
sampling problem is reduced to manageable size and maximum use is made
of prior information.
The three major variables used in classifying boilers for sampling
were fuel burned (coal, gas and oil), type of firing (front wal~, opposed
wall, tangential, vertical and cyclone) and boiler size (steam rates of .
less than 1, I to 3 and over 3 million pounds of steam per hour). This
classification system defines 45 subpopulations without considering other
important variables such as burner configuration, number of furnaces,
iurnace loading, burner types, air system, boiler operating flexibility
and fuel grade. Breakdown of boilers into the above three size
categories represents the gross distribution of electric utility
'boilers in the U.S.. weighted by actual electrical generation.'
Table 4-1 presents the planned proportional, stratified sample
of test boilers. 'The allocation of test boilers to the subpopulations
was determined using the statistical guidelines of optimum allocation
considering the number of boilers in use within each subpopulation, the
relative variation of boilers in each subpcpulation,andthe cost of testing
within e3ch subpcpulaticn. This id~al plan call~ci ior twenty boilers (34 boiler-
fuel combinations) to be tested with replication in the most important
groups. Thus, 6 our of 7 of the "A", groups, 3 out of the "B" ~roups, 5 out
8 "e" and 9 out of 10 "D" groups were to be sampled.
The selection of individual boilers to represent each subgroup
was based on a number of technical as well as economic factors. Boiler
operating flexibil~ty, availability of special combustion control equip-
ment such as flue gas recirculation and two-stage combustion "NO-ports,"
and the ability to burn more than one type of fuel were key factors~ To
reduce administrative costs, the number of cooperating companies was
minimized consistent with wide geographic dispersion of boilers to assure
a variety of fuel compositions. Stations with several boilers, particularly
those that burned more than one fuel type were given special consideration
in order to minimize travel time and administrative costs. In addition,
station management experience in operating boilers under a varie~y of
operating conditions and. their willingness to run their boilers according
.to a .planned statistical program were considered in selecting boilers.
Thus, to briefly summarize this section, there were many statistical
principles which guided the selection of boilers, even though a strict
probability sampling plan was not used. A proportional, stratified sample
of boilers .was selected for testing~ Replication within seyeral important
strata was planned so that objective measur~s of bOiler-to-)oiler variation
could be obtained. Pait'ed sampling was employed to reduce ;'costs and to
enhance the comparison of emissions from different fuels within the same
boilers. A minimum number of companies and stations were selected in
order .to minimize necessary rreetings for agreement and approval of test
-------
1-"--
TABLE 4-1
--
BOILER SUBPOPULATIONS TO BE STUDIED
Boiler
Size as Fuel and Type of Firing
Steam Rate Oil Coal Gas
(106 Lbs./Hr.) FW HO V T CY FW HO V T CY FW HO V T CY
-
A C C B .A A C A D D C
- - - -
<1 5 9 9 13 10 9
13
-
1-3 A B C D B A C A B C D
"4 -
1 12 15 2 7 18 2 12 15 18
2 14* 8 8 14*
8 17 . 11
11
-
~3 D D D D D C D
-
16 3 6 19 3 16' .\
20
..
.t-
o
I
* All-Wall Fired Boiler
A
B
C
D
Estimated. % of United States Boilers Within Each Fuel Type
>12
8 to 12
4 to 8
<4
Code Letters
Code Numbers
1 to 20 identify 'boilers in original program plan. .
Type of Firin~ Codes:
FW - Front Wall .
HO - Horizontally Opposed
V - Vertical
T Tangential
CY Cyclone
-------
",
- 41 -
prograJIIS, and to minimize travel time so that a maximum number of boilers
could be tested in the allotted time period. In addition, representative
boilers of all four major' U. S. boiler manufacturers (Babcock, and Hilcox,
Combustion Engineering, Foster-Wheeler and Riley Stoker) were tested.'
4.1.2
Representative Sample Selection
The characterization of flue gases from existing stacks or
ducts requireiO a sampling program that is s,tatistically s:i..gnificant.
Since the volume of gas passing any given cross-section of the duct
per unit time is the product of the average gas velocity and the cross-
sectional area, and the composition of the stream may vary within the
given cross-section, one must be sure that the sampling procedure
provides a true characterization of the flue gas stream.
In choosing the location for the measurement of the gas
two things must be kept in mind. First, the determination should
where the gas flow is as uniform as possible and second, the area
be convenient for setting up equipment.
stream,
be made
should
Having selected the location at which to make the test, the
number and location of sampling points must be determined. The number
of areas samples should be large enough to insure a xeasonably accurate
measurement of the average velocity over the entire cross-section.
However, where there is a fluctuation in the velocity with time at anyone
point it is Rreferable to make many observations at a few points to
a few observations at many points.
For this test ,program the number of equal duct areas that could
be monitored reliably was 12. Three ,points were composited and measured
for two minutes once every eight minutes., This procedure was repeated
four times for each test. During the two minute test period the flue
gas composition cycled one to two time~ and an average value was recorded.
In,some tests where large variati0us pccurred, each point was recorded
to determine the differences betwen extremes for a particular'boiler
test configuration. Thus,a total of 16 measurements (of 3 point C0mpo-
sites) were obtained from each test run. The average of these 16 measure-
ments is equivalent to a proportional, stratified sample of,48 grab
samples. This measurement system also provided the opportunity for
internal check of time-to-time variation as well as variation within the
cross section of the duct for each 'test run. ThuR, g!."oss errors and
responses to unplanned boiler changes could be detected and evaluated be-
fore final run average emissions were calculated.
-------
4.1. 3
- 42 ,-
Boiler Test Program Des~~
Modern statistical experimental design offered effective guidance
in planning the test program for each'boiler so that required data could be
obtained with minimum cost, time, and effort. A sys tematicprocedure was
used to ~ssure that all pertinent information was gathered and evaluated
in planning each test program. Table 4-2 provides an outline of this pro-
cedure \.;hich \.as used in planning test programs on all boilers.
TABLE 4-2
1.
Planning the Test Program
Design the Test Program
a.
b.
Hold a Conference of all Parties Concerned
1.
2.
State the objectives of the test program.
Agree on magnitude of emission differences con-
sidered worthwhile. '
Choose the operating factors to be studied.
Determine the practical range of each factor
and specific levels.
Choose end measurements to be made.
Consider sampling variability and precision
of test methods.
Determine limitations of time~ cost,operating
flexibility, manpower, testing equipment, weather, etc.
3.
4.
5.
6.
7.
, Design Program in Preliminary Form
c.
2.
1.
2;
3.
Prepare a systematic a'nd. inclusive schedule.
Provide for sequential staging of schedule.
Eliminate effects of varia~les not under study
by controlling, balancing, or randomizing them.
Minimize number of experimental runs.
4.
Review the Design with All Concerned
1.
2.
Adjust program if desirable.
Spell out steps in unmistakable terms.
Plan and Carry Out Experimental Work
1.
2.
Develop methods, test equipment, and sampling equipment.
Determine sampling and testing errors and standardi~e
procedures.
Repeat base runs to determine true repeatability error.
Run experimental trials sequentially.
3.
4.
The major objectives of the boiler test programs were to (1)
obtain base-line uncontrolled emission rates on boilers representative of
the most important types in the United States, and (2) to determine the
applicability 'of the'potential combustion controls toNOx ~mission control.
. .
-------
- {13 -
Due to limited time, it was not possible to determine optimum boiler
operating conditions for NO control, although in a number of cases
the general optimal region ~ould be outlined from analysis of the
test results obtained.
The most important guiding principles used in planning each
test program were: (1) minimize the number of test runs required to
meet test program objectives by using the most efficient experimental
design available considering each boiler's operating flexibility and the
estimated experimental error, (2) make use ot all accumulated knowiedge
and experience available in crystallizing test objectives and planuing
the experimental design for each boiler test program, (3) utilize the
sequential approach to experimental design by planning readily augmentable
blocks of experimental runs, (4) take advantage of fractional factorial designs
where the possible number of experimental runs obtained through varying
pertinent operating factors was too large, (5) replicate a suf-
,ficient number of test runs to obtain a reliable measure of experimental
error or repeatability, (6) determine the. order of runs by a pure
random selection process unless this procedure would lead to excessive
operating costs or a greatly reduced number. of test runs per day and
,
(7) reduce the effects of variables not under study by controlling,
balancing, or randomizing them. .
These guiding principles, basel! on both theory and practice,
,led us to. take advantage of factorial type experimental designs in most
boiler test programs. Full factorial designs make it possible (1) to estim-
ate the main effects of each factor inde?endent of each other, (2) to
determine the dependence of the effect of every factor upon the level oi the
others (interactions), (3) to deter~ne the effects with maximum precision,
and (4) 'to obtain an estimate of the experimen.tal error for the purpose
of as~essing the significance. of the effects. Where the number of operating
variables was too large to perform a complete factorial design, frac-
tional designs were used.
The combustion control variables included in most of the
experimental programs were load, excess air level and some form of "
staged combustion. With two levels of each of the three variables tested,
a complete factorial would require 8 runs while a total of 27 runs would be
required for a full factorial design of 3 variables each at 3 levels.
The need to test a relatively large number of boiler-fuel combinations
restricted the "number of test runs feasible on each boiler, and thus most
operating variables were tested at only two levels. An except~on to this
general rule was boiler load. The first few oil and gas fired boilers in
the study were tested at three load levels in order to determine if emission
rates .changed linearly with load and also if there were significant excess air
and staging interactions with load. Later, boilers were generally tested
at only two load levels since interactions were found to be fairly small,
Roughly linear relationships were found between NOx emissions and load, and
rather complete combustion control evaluation was desired at full load and at
I .
-------
- 44 - .
reduced load conditions. \-lhere 5 or 6 operating variables were avail-
able for testing, a complete factorial.experiment at two levels would
require 32 and 64 runs, respectively. Consequently, partially
replicated factorials were designed with emphasis placed on areas
felt to be of the greatest interest, such as full load, low excess
air, anJ/or staged combustion. . .
A practical balance was sought between the statistical desir-
ability of pure randomization of the order of test runs (which would
'often greatly reduce the number of test runs accomplished per day) com-
pared to ordering test runs in light of operating costs and convenience.
In most cases, it was felt that the increased number of runs available
per day through evaluation of operating considerations more than offset
the possible loss in quantification of statistical probabilities. In
addition, the effect of variable fuel quality and unmeasured boiler'
operating factors with time were minimized by limiting the test program
to fewer test days. Another violation of pure randomization of run
order was often made to assure better "p8:ired comparisons" within one
day's runs. For example, the lowest level of excess air that could be used
at a given load without exceeding acceptable hydrocarbon or carbon monoxid~
emission limits* was heavily dependent upon a number of boiler design and
operating conditions, and therefore, was difficult to predict in advance.
Thus, it. was often .desirable to first reduce the excess air to the
minimum possible under the prevailing boiler conditions, and then make
a run at a higher excess air level, with a known minimum difference,
rather than make these runs in the reverse order.
*.
Measureable hydrocarbon emissions in this study were found to be negligible.
The "acceptable" level of CO was set at 200 ppm, which corresponded to
the practice of some of the boiler operators, and was found to correspond
to the level of excess air below which a sharp rise in CO emissions would
occur.
. .
. . ~~"i/1 ..
-------
- 45 -
4.2
Design of Mobile Sampling
and Analytical System
Neeting the objectives of our field program of measuring NO
and related products of combustion emitted. from a variety. of power boflers
required a versatile, transportable sampling and.anal~tical train~ Such
a system had to be self-contained, mobile, and include provisions for wet
chemical analysis of grab samples. ~linimum set-up time was another re-
quirement for the sampling and analytical system, which had to be
installed at the actual sampling site to reduce the possibility of changes
in the flue gas composition. Ideally, the instruments should have been
located at the sampling.point, but since this location was frequently in-
accessible and was usually unsheltered, some compromise had to b~ made.
Other requirements for the instruments for the measurement of the concentra-
tion of the flue gas components were easy calibration, maintenance-free and
repeatable operation, and the aoiiity to monitor gas con~ositions continuously.
The last requirement is of extreme importance in a field program, where
directional effects of operating changes must be assessed immediately.
Finally, the instrumental methods 'had to be compared against
wet chemical methods of analysis, as needed, to validate the accuracy of
the sampling system and continuous monitoring instrumentation.
4.2.1
Sampling Svstem
The -objective of obtaining data from coal, as well as .oil and
gas fired boilers required the development of an elaborate sampling
system. Consideration of the solubility of N02 in water, the presence
of oxides of sulfur, and the high ~o~centration of particulates in the
combustion gases were taken into account in the design of the sampling
system. The sampling system was designed with adequate flexibility to
allow gas sampling from different size boilers or other stationary combus-
tion equipment. It could handle flue gases with heavy particulate loading
from coal fired units, as well as light particulate loading from oil fired
units. The sampling assembly was a dry-type system with appropriate particu-
late filters, pumps, and a refrigeration unit to cool the samples to.a
35°F dew point before analysis.
. The sampling points for flue gas comp0nents were usually located
in the duct-work between the economizer and the air heater. This was done
to provide reasonably homogeneous gas samples at the temperatures to which the
probes could be subjected, and to avoid dilution of the samples 9Y
leakage in the air heaters of the boilers tested. In this part of the
duct-work, temperatures usually ranged between 550°F and 800°F, and gas
velocities were between 30 and 80 feet per second.
-------
- 46 -
The variability of ducting between different boilers required
the design of adjustable sampling probes. These probes were designed
with interchangeable gas sampling tubes. Since we sampled from "equal
areas" in ducts of different sizes, the probes ,...ere assembled on location
for the particular duct. A special pitot tube and a thermocouple were
located at the midpoint of each probe with a sampling tube. The re- .
maining two gas sampling tubes were then assembled and the entire probe
was ready to be inserted into the duct. Each probe was fitted with a
quick disconnect as a mounting assembly for easy insertion into the
boiler. All pieces of the sampling equipment between the van and the
- probes were of the quick-disconnect type for ease of assel;tbly and
assurance of a leak-proof connection at all intermediate points. Figure
4-1 shO\"s a schematic diagram of the sampling and analytical system'.,
Detailed illustrations of this system are given in the Appendix.
In running field tests, the gas samples were withdrawn from
the boiler under vacuum through stainless steel probes to heated paper
filters where the particulate matter was removed. These paper filters
were maintained at 300-500°F. The gases were then passed through
rotameters, which were followed by a packed gla$s wool column for S03
removal. Initially, the gas temperatures were kept as high as possible
to minimize condensation in the particulate filters. After leaving
the packed. column at 250-300°F, the gas samples passed at temperatures
above the dew-point through heated Teflon lines to the vacuum/pressure
'pumps. The sample was then split with a portion at 120°F sent to
. the 'NOZ instrUment and the balance o'f the stream refrigerated to
a 35°F dew-point before being sent to the van for analysis. Usually,
the van was located 100 to 200 feet from this point and the gas stream
flowed through Teflon lines throughout this dis tance.
The sampling system performed well during the test program,
however, some difficulties were encounter~d with the vacuum pressure pumps.
The pumps originally acquired for our sampling system were stainless steel
bellows pumps. These pumps were manufactured with a clearance volume for
slugging liquid entrainment. After about 40 hours of use the pumps began
to leak and inspection revealed that the bellows became deformed and
perforated with pinholes. The probable cause of failure was condensate
remaining in the pump during the compression stroke deforming the bellows.
The manufacturer (~!etal Bellows Corp.) supplied replacement sets of pumps
and we revised the sampling system in an attempt to overcome the problem.
Water knockouts were incorporated before the pumps and the pumps were
mounted upside down to facilitate draining of liquids that condensed dur-
ing shutdown. This procedure did not eliminate the problem 'and rtew' Teflon
faced neoprene diaphragm pumps (Diapumps) had to be installed. These
proved to be satisfactory in use for the remainder of the field test
program.
. .
-------
Probe (4 each)
Boiler
Duct
800°F
Thermocouple
Pitot Tube
500°F
Particulate filters (heated)
rotameters
heated lines
co .
C02
NO
S02
02
Hydrocarbons I
Figure 4-1
ESSO RESEARCH TRANSPO'RTA8LE SAMPLING
AND ANALYTICAL SYSTEM
cd!
Remote Instruments
(at boiler duct>
35°F
refrig era tor
Solenoid
Valve
H20
to NO 2
w
Solenoid
Valve
D
v
w
.D-
v
v
v
Sampling
van
. !
I
~
"
. I
vent
5 psi relief
valve
-------
- 48 -
Another problem of air leaking into the lines was found to
be due to the flexible lines. Hhile these lines we.re designed for
high pressures and temperatures, their flexibility was not sufficient
for our purpose. After severe bends, necessitated by probe locations,
leaks would develop when the lines were heated to high temperatures.
He are currently experimenting with a new design which eliminates tpe
protective wire braid from the line on a replacement basis. Preliminary
evaluation shows that this type of line is superior to the old one. Also,
pressure-testing all lines at each boiler in' future work will be required
to correct this problem.
4.2.2
Analytical Instrument Train
The selection of instruments for the measurement of- flue gas.
composition was complicated by the relatively short delivery time neces-
sitated by the requirement to begin the field test program in the early
part of the contractual period. The instruments had to be installed and
wired in a console and checked out before the test program could begin.
Beckman Instruments Inc. was chosen as the supplier for these instruments
because of their ability to deliver monitoring instrumentation in a short
time and Esso Research and Engineering Company's prior familiarity with
their analyzers in other air pollutant measurement trains. Another reason
. was the availability of the field service organ~zationof Beckman which was
felt' to be an important asset for field studies.
The instruments selected for monitoring flue gases were
i:hose tllat had been demonstrated to be accurate and relatively troubl~-
free in previously used exhaust gas analytical trains at Esso. Our van
was equipped \vi.th Beckman non-dispersive infrared analyzers to measure NO,
CO, C02 and S02, a non-dispersive ultrav~olet analyzer for N02 measurement,
a polarographic 02 analyzer and a flame ionization detector for
hydrocarbon analY6is. The meas~£ing ranges 0f these continuous moniter:
are listed in Table 4-3.
. .
-------
-.49 -
TABLE 4-3
Continuous Analytical
Instruments in Esso Van
Beckman
Instruments
Technique
Measuring
Range
0-400 ppm
0-2000 ppm
NO
Non-dispersive infrared
N02
Non-dispersive ultraviolet
0-100 ppm
0-400 ppm
°2
Polarographic
0-5%
0-25%
C02
Non-dispersive infrared
0-20%
GO
Non-dispersive infrared
0-200 ppm
0-1000 ppm
S02
Non-dispersive infrared
0-600 ppm
0-3000 ppm
. Hydrocarbons
Flame ionization detection
0-10 PlJHi
0-100 ppm
0-1000 ppm
The instruments were housed in a console which was shock-mounted
inside the van. All connections tothe console were made beneath the floor
to prevent a tripping hazard. Separate raceways for piping and electric
wires terminated in the base of the cabinet. Each analyzer was cODnected
in parallel to the sample and calibration gas lines to insure that each
analyzer would be operated independently of the others.
In the original design of the sampling-analytical train and during
its construction, sufficient flexibility was engineered into o~r system to
allow additional analyzers to be installed, and for modifications and special
sample handling techniques to be incorporated. In addition to analytical
instrumentation for continuously measuring all of the major flue gas com-
ponents including NO, N02, CO, C02, 02 and hydrocarbons (with an instrument
added later to measure S02ft the temperature and velocity of the gases in
the duct coul~ also be measured. A novel programmable sample timer was
installed to allow any sample cycle to be simply dialed into the equipment.
-------
- 50'-
Normally, measurements from fo~r different locations within the ducts
could be made in eight minvtes. After steady state conditions 'in the
b~ilcr had been established, the sampling time of 32 minutes per test
allowed 4 repeats of each location assuring that reproducible data
were obtained. The programmable sample timer proved to be very useful
when monitoring operations at very low excess air levels, because the
most sensitive areas had to be monitored more frequently.
Separate calibration gas cylinders in appropriate concentra-
tions with N~ carrier gas for each analyzer were installed in the van.
Each cylinde~ was equipped with a regulator, safety relief valve, ex-
cess flow check valve and other necessary valves and piping. The
cylinders \yere secU1:ely fastened to the body nnd frame of the vehicle
to insure safe transportation. Each cylinder was piped directly to
the analyzer for iase of operation.
probes.
from the
quired.
The sample gases were pumped to the van from four separate
While one sample was being monitored, the other three were vented
van to insure that a fresh sample would be available when re-
This operation was performed automatically by the sample timer.
The.gases were analyzed as received at'the 35°F dew point except
for the NO instrument which had twin chemical driers for the removal of
water. The driers were filled with fresh indicating drierite before each,
run and were only used until the color change had reached the mid~point of
the tubes.
The hydrocarbon instrument, a Beckman Model 400 flame ionization
detector, measured unly the hydl-ocarDons that reach the 'instrument. Only
hydrocarbons volatile under the sampling conditions could' be measured by this
instrument because of the sample preparation system. The, initial filt,ration at
300-500°F removed solid as well as liquid particulates. The glass wool packed
column, maintained at 250°-300°F, might have removed lower boiling liquids. The
gases were then refrigerated to a 35°F dew point before being analyzed for
hydrocarbons. The condensate from the refirgeration unit was analyzed for
organic carbon in selected test runs, and was found to contain on the average
20-?0 ppm hydrocarbon equivalent in the flue gas.
In addition to the recorders in the van, separate trend re-
corders for NO, 02 and CO were provided for remote observation of flue
gas concentrations in the control room of the utility. The effects of
changes in operating variables, therefore, were continuously displaced
to provide 'information to the operating personnel in the control roam.
While in most cases the instruments performed satisfactorily,
some special problems did arise. The GO instrument, which has a long
path infrared cell, \-las found to be sensitive to 200 ppm CO full scale. Hoisture
interference was a major problem for this long path instrument. Changes
'were made in the filter cells, heater circuits, and in the gold coating
of'the sample cell. .These changes reduced the problem .but could not
completely eliminate it. Although this problem may be circumvented by
using chemical driers upstream of the sample cell, a more satisfactory
solution is desirable for future measurements of this type. Narrow
band-path optical filters will be installed to reduce moisture inter-
ference with. the response of the sample cell.
-------
51.-
The NOZ instrument, a non-dispersive ult'ravinlet analyzer, \.as
designed for 100 ppm NOZ full scale. However, the accuracy of measuring
extremely, small amuunts of NOZ in the flue gases was affected by the noise
level of the instrument. This noise level was substantially increased by
the remote location of the N02 instrument, and the varying temperature
environment.
Our experience demonstrated that with the NOZ analyzer (an in-
strument designed for a laboratory environment) even tilOugh it was shock
mounted for vibration, the sensitivity of the mirror adjuStment was such
that we lost calibration during runs due to boil~r-induced and other
vibrations of very low frequency. Also, because this instrument \.,as used
for measuring hot samples of the corrosive flue gas which h3!a not been
subjected to condensation, the analyzer was fouled easily. Small tempera-
ture variations due to the wind-chill factor at unprotected outside
boiler locations could cause condensation in the analyzer. Then, an
elaborate clf'aning procedure ;"~$ required, which could not be performed
during actual testing. Based on these findings, our future plans
are to redesign this portion of the analytical system.
Integration of Sampling-
Analytical System into Hobile Van
The van used to house the instruments, sampling train, and wet
chemical laboratory is a Winnebago mobile home shell. The basis for theselec-
tion was availability, allowable payload weight and' a self-contained '
, propulsion syste!TI to prQvide maximum mobility. Thp. Bhell is Z7 feet long
by 7 feet 6 inches wide and is mounted on ,a Dodge truck chassis. The.
driver compartment is located in the first 5 feet of the shell. The van
is air conditioned and heated for all~weather operation. A gasoline-
powered electric generator housed in a compartment of the chassis provides
power for lighting and air'conditioning during the initial equipment de-
ployment. However, during samplin~ and data collection the van operated
with electricity provided at the generating station. A floor plan of the
van is presented in Figure 4-Z.
4.Z.3
The instruments are housed in a permanent shock mo.unted instru-
ment console. The calibration gases are permanently installed in the rear
of the van. These cyclinders are securely mounted for traveling and each
bottle has its own low pressure safety valve and velocity check in addi-
tion to standard regulators and valves. The rear of the van is designed as
a laboratory bench including a sink. It is used for experimentation
and as a foul weather workbench. A swingaway desk top and a file cabinet
provide an area fo~ data analysis inside the van. A Sony programmable desk
calculator for preliminary data reduction is part of the equipment carried
in the van.
-------
~tep
ro
(1)
....
«
....
(1)
>
....
Q
""IL.-~-'.
(1)
(1) S::,
i.L :so, Desk Top
ul
Figure 4-2
FLOOR PLAN OF SAM PLI NG-ANAL YTICAL VAN
Overhead Wall Cabinet
portable]
Instrument
Cabinet
Closet
Instrument Cabinet
o Heater
Overhead Wall
Cabi net
00
00
Cyl.
Step.
Bench
....
(1).
.... VI
s::
Sink :::; N.
o
U
Bench
-------
-.53 -
An electrical distribution center for the van includes voltage
regulators ahead of the instrumentation to anticipate any large variations
in line voltage between generating stations. Normal power requirements are
14 KVA for the van and the remote sampling train.
The van holds its own water supply and has a
for equipment deployment. The external connections to
disconnects in an umbilical area.
portable winch
the van are all quick
4.2.4
Comparisons of Van Data ~ith Other Methods
A number of times during t~e test program comparisons were
made wi th other methods for determining the gaseous composition of the
test stream. Generally excellent agre~ment has been obtained and
summaries of these data are presented in the following tables. The NDIR NO
values reported in these comparison tables are the quantities of x
NO measured adjusted by a factor of 1.05 to take into account the NO~ portion
<-
of the total NOx' The same correction factor was found to be acceptable
in actual test runs when the N02 analyzex was malfunctioning or its.
reading was within the n~ise range of the instrument.
.The Envirometrics N5-200 instrument was compared with the
Beckman NDIR .NO analyzer. The NS-200 was operated in two modes: (1) witt\ a
scrubber to remove SO? as is done with the Dynasciences analyzer based on
a similar electrochemical principle and (2) without the scrubber to allow com-
pensation for Sr.2 in dual mode operation. The S02 compensation wa~ calculated
manually for the purposes of this test. While the scrubber did.
remove some of the NO and N02 in the sample gas, operation wi.th the
scrubber appeared to give closer agreement with NDIR than operation
without the scrubber; there seemed t~ be an approximately 20 ppm
uncertainty in the 502 reading. These comparisons are shown in Tables 4-4
and 4-5.
TABLE 4-4
COMPARISON OF ENVIRONMETRICS ANALYZER*
WITH NDIR (502 SCRUBBING)
Average
NOx
Environmetrics
ppm (Dry Basis)
170
155
200
200
205
190
175
185
185
=
NOx
NDIR
ppm (Dry Basis)
173
153
207
196
207
201
177
191
188
Difference
ppm
-3
+2
-7
+4
-2
-11
-2
-6
-5
*
Readings to nearest 5 ppm (1000 ppm full scale).
-------
- ,5'4 -
TABLE 4-5
COMPARISON OF, ENVIROMETRICS ANALYZER*
WITH NDIR (NO SO? SCRUBBING)
Compensated>':** NOx
NOx Reading** S02 Reading NOx Reading NDIR Difference
ppm (Dry Basis) ppm (Dry Basis) ppm (Dry Basis) ppm (Dry Basis ppm
530 325 170' 177 7
465 245 195 187 8
505 280 195 . 173 22
,475 310 135 170 35
545 355 155 190 35
Average = 166 179 21
*
**
***
Readings to nearest 5 ppm (1000 ppm full scale).
NOx reading is 100% of NO, 80% of NOx' 110% of S02.
Manually calculated compensation (Envirometrics analyzer
has automatic compensation mode}.
. A comparison between the Beckman NDIR and a Whittaker
(Dynasciences) polarographic NO instrument was als~ performed on
flue gas from a 200 ~M boil~r ~ng,Q.5% sul£ur fuel oil. Numerous
changes were made r1l1ring the course of t:hp. t:P.!';t!':, inc1.ur1i.ng the varia-
tions of' excess ai 1:, flue gas recirculation, and staged fi ring of the burner:'"
No details of the exact c0nditions are presented in Table 2-6, since the pur-
pose of these. me.asurements was to compare the relative reading$ of the
two analyzers.
-------
-.55 -
TABLE 4-6
CmlPARISON OF HHITTAKER POLAROGRAPHIC NO
AND NDIR NO INSTRU"HENTS x
Polarographic,*
ppm NO" (drv)
NDIR*
ppm NO, (dry)
Difference
ppm
376
340
293
251
281
220
320
385
352
315
286
249
271
227
330
414
Average =
24
25
7
2
10
7
10
29
14
*
Each point is the ave rage of four readings
over an eight minute period. Flue gas oxygen
varied between 1.8 and 2.7 percent.
levels
The polarographic instrument responds t~ both NO and N02:
this particular sensor was found to respond ]00% to NOZ in dry NZ'
Th~ NIHR responds only to NO. A liqui.d scrubber for S02 was used on
the polarographic instrument. Tests indicated that it absorbed 1.5
p.ircent of the inlet NO in a dry N2 s 1: r&am. No tests were conducted
to determine the amount of N02 removed in the scrubber but the man-
ufacturer states that less than 5% is removed. During the four hour
test period, it was not necessary' to zero or span the polarographic
instrument and" the NDIR instrument required only infrequent calibration.
I .
i
No independent N02 measurements were made during this comparison
NOZ measurements using a .Beckman NDUV N02 analyzer in previous tests
und~r similar conditions were in the 10 to 20 ppm range. lienee, although
the polarographic instrument responds .to both NO and N02, the absorption
of part of the N02 by the scrubber and the low anticipated level of NOZ
should cause the readings of the two instruments to be in fairly close
agreement. .
test.
-------
- 56 -
Comparisons made against a DuPont 461 NO 'analyzer and another
NDlR CO instrument are presented below; 'These dat~ were obtained' by
sampling the flue gas generated in a coal fired fluid bed laboratory
comb us tor. For five gas meas urements, the NO readings by all methods
were corrected to 3% 02 on a dry basis. x
Others *
Van*
Difference, ppm
CO, ppm (3% 02)
NO , ppm (3% 02)
x
631
687
648
680
17
7
* 02 level 5%.
Both NO and CO checks gave good agreement. Comparison. data
obtained in testing boiler A on NOx' 02' and C02 are presented in
Table 2-7.
TABLE 4-7
COMPARISON OF VAN INSTRUMENTS IN BOILER TESTS
Van Others * NOx
NOx ppm 02 C02 N0xt ppm 02 C02 Difference
Probe (3% O~ % % (3% ° ~ % % ppm'
.1 129 2.7 10.7 125 2.9 10.1 4
2 J 151' 1.0 11.6 136 1.2 11.1 15
3 201 2.6 10.8 192 2.8 10.5 9
I. 379 2.3 10.9 357 2.2 10.8 22
't
Average of 3 samples by PDS for NOx and Orsat analysis for 02"
For all three species compared in Table 4-7, the differences obtained
with different analytical methods were within the accuracy of the measur~-
ments.
*
The following tables provide comparison data on NOx and 02
obtained at Boiler H and Boiler C with wet chemical methods performed by an
outside laboratory"
TABLE 4-8
BOILER H ANALYTICAL COMPARISONS
Van
NOx' ppm
(3% 02L
°2
.%
Others*
NOx' ppm
(3% 0zL
°2
%
NOx
Difference
ppm
Test IV
Avg. of 5
Samples
217
6.2
217
6.4
o
Test IX
Avg. of 3
Samples
148
3.9
180
3.9
32
*
Average of PDS for NO and Orsat analyses for '02' '
x .
-------
-: 57.-
. TABLE 4-9
- -' .
BOILER C ANALYTICAL COMPARISONS
Van
NOx' ppm
(3% 02L
°2
%
Othe rs *
NOx' ppm
(3% ° 2L
°2
%
NOx
Difference
ppm
Test V
Avg. of 4
Samples 400 2.6 400 2.6 0
Tes t II
Avg. of 12
Samples 270 2.2 300 2.6 30
Test III
Avg. of 4
Samples 675 3.3 678 3.0 3
Average of PDS for NOx and Orsat analyses for 02
In general, the agreement was excellent between NDIR and PDS
methods, similar to the conclusions of a recent study by Fisher and
Hu1s(1) which showed that an NDIR NO analyzer gave comparable reading8
over a wide range to those obtained by the PDS method. However, in their
comparisons the Saltzman technique gave consistently lower values (by
about 100 ppm) than either the NDIR or PDS methods. .
*
I
I .
-------
4.3
- 58 -
Test P.rocedures
The planning and implementation of measuring emissions from
utility boilers consisted of the 'fol10wing major phases in this study:
a
First, on a preliminary basis, candidate boilers were
selected for testing, corresponding to the considerations
discussed in Section 4.1, Le., based on thedistribu- .
tion of utility boilers by fuel type, size, and type of
firing.
o
Second, the voluntary cooperation of utility owner-
, operators was solicited. In these initial meetings with
them, our program plans, major objectives, and the desir-
able boiler features for emission testing were discussed
with the owner-operators. For testing emissions from
three specially selected coal fired boilers, personnel
of the boiler manufacturer subcontractors who suggested
representative boilers of their manufacture also partici-
pated in the meetings with the utility owner-operators.
o
Third, the final boiler selection, the detailed schedule
for the test program, and the changes in boiler operating
variable:; ~vere agreed upon with the utility' owner-
operators prior to testing. Sequentiallyblocked
test programs were designed for each boilQr in such a way
that important findings of the initial emission tests could
be used to modify the plans for subsequent testing of t~e
boiler. during the course of the program.
o
Fourth, acoording to the oVerall Boiler Test Program
schedule, the Esso sampling-~nalytical van was deployed
to each generating station where emission testing would
take place. Our equipment was set up for measuring
emissions under diverse operating conditions effected by
the operating utility personnel cooperating with us, and
the program plans were imp1em,ented t.o obtain data under
base-line and modified operating conditions, within the
limits of flexibility of the equipment tested. Steam-
side data were gathered on 'the "three selected coal fired
boilers by their respective manufacturers, to assess the
thermal consequences of operatins changes made for re-
ducing NOx emissions.
Detailed aspects of planning and conducting the Boiler Test
Program wit\1 owner-operators and manufacturers are discussed
in this section.
-------
- .59
4.3.1
Planning the Program with Boiler
Owner-Operators and Manufacturers
Our preliminary boiler'selection for testing was based on the
information available to us through the detailed steam-electric plant
survey conducted as part of the Phase I stationary NO study (1) which
provided data on 670 boiler-fuel combinations, and ot~er infor;ation
sources. In addition to trying fo~ a proper balance of boilers to be
tested according to type of fuel, type of firing, and size, we strongly
focused on the potential operating flexibility of the boilers for
implementing changes beneficial to NOx emission control, as identified
in our Phase I study. '
Thus, we were able to generate a preliminary list of boilers
to be tested, representing on a weighted basis the most important
utility boiler-fuel combinations. Of the 20 boilers initially selected,
15 were actually tested and two additional boilers were included in the
program.
Major variables of interest to NOx emission control were the
, boiler load, level of excess air, potential for staged combustion, flue
gas recirculation, air preheat temperature, and other characteristics
which could affect the level of NOx emissions, e.g., fuel composition,
furnace and burner configuration and operation. '
Representatives of electric utility companies who cooperated
with us in the Phase I stationary NOx study (l) by supplying data on the
design and operation of their boilers and emission levels measured by
them were visited to solicit their cooperation in the Boiler Tes~ Program.
Our strategy was to visit the minimum number of utility headquarters for
in-priniciple agreement to participate in the program, and then to take
advantage of the availability of several utility boilers at a given
generating station chosen for testing, to maximize the amount of informa-
tion obtained on representative major boiler types. Also, in scheduling
the tests, we felt it was desirable to carry out the early part of the
program near the Linden Esso Research Center to enable us to make neces-
sary corrections and changes in the sampling-analytical system. Further-
more, we attempted to include utilities in the program with .background
and experience in emission testing and control. In general, these first
meetings with the utilities consisted of brief presentations of the
Phase I stationary NOx study findings, and of the plans and objectives of
the Boiler Test Program. As a result of these discussions, we obtained
the agreement ,of the utility owner-operators to cooperate in the program
and their permission to visit candidate bo1.1ers to obtain a better under-
standing of their design and operation, and to discuss plans and potential prob-
lems with operating personnel. Thus, we were able to validate our thinking
about the conceptual test program design, and modify it by additions or '
substitutions of boilers to be tested based on the information gathered
during these visits and discussions..
-------
. "if'
60 -
The detailed review of the test plans with boiler operating
and boiler manufacturing personnel also included the discussion of
provisions for sampling locations, additional ope~.~ting data logging,
fuel sampling, and other pertinent variables to be monitored during
. the emi,ssion measurements.
4.3.2
Conducting the Test Program
Conducting the test program efficiently was greatly simplified
d~e to the detailed planning and preparation for testing carried out
jointly with boiler owner-operators, and manufacturers. Thus, the agreed
upon operating program, detailed data recording forms, communication links
with all parties, alternative experimental pla~s {in case of unplanned
changes in loads, fuels or equipment), arrangement for manpower to obtain
fuel samples, overtime provisions, etc., provided a basis for rapid
accomplishments and decisions on necessary changes .to plans.
Flue gas samples were taken to represent planned steady state
furnace and steam conditions. Thus, it was necessary to determine by
careful observations of furnace flames, control room instruments, and flue
gas measurements that the operating variables such as load, ex~~ss air,
flue gas recirculation rates, damper settings, etc., were at their proper
levels for each experimental run. .
The .length of e
-------
- 61 -
. ,
, 5.
CO}ffiUSTION MODIFICATION'TECHNI9UE& FOR NO
h
ENlSSION CONTROL
Our Phase I stationary NO study (l) assessed combustion modi-
fication techniques for NO emissioR control in two broad categories:
x
(a) Modification of combustion operating conditions.
(b) Modification of combustion equipment design features.
To investigate the scope of applicability of combustion modi-
fications for NO emission control from utility boilers, limited by
available equipm~nt, only changes in combustion operating conditions
could be considered for the present study. '
The Boiler Test Program was designed to explore the broad limits
of applicability of combustion modifications, within the flexibility of the
eqUipment. Known combustion operation modifications (1, 3, 4) previously applied
in full scale tests exclusively on gas and oil fired installations provided
the starting point for our tests. The prime objective of the Esso field tests
was to conduct a statistically designed program with all three fossil fuel
types on a representative sample of boilers, taking into account the known
major variables. The major combustion operation changes explored in our study
are discussed in this section.
5.1
Load Reduction
Operating boilers under ~educed load conditions decreases the
combustion.intensity or volumetric heat release rate. The net effect
is to produce lower effective peak temperatures for NO formation i~ the
furnace section of the furnace. Our experimental design called for measuring
emissions at normal ("full") load conditions, and at various fractional load
levels, as feasible with each boiler-fuel combination tested. The lower limit
of reduced load operation was usually set by considerations of steam tempera-
.ture control, and the demand on generating capacity.
5.2
Low Excess Air Firing
Low excess air firing of gas and oil in boilers reduces NOx emissions,
primarily because of the lack of availability of oxygen. Firing with "low
excess air" is of course a relative term, because of the boiler-to-boiler
variations in the "normal" level of excess air, as established by the boiler
operators, depending on fuel type and boiler design and operating conditions.
In our Boiler Test Program, the objective was to measure emissions under base-
line, "normal" excess air conditions, and then to determine the extent of reduc-
tion in NOx by asking the operator to run the furnace with the lowest permissible
excess air supply. The lowest practical excess air levels were dictated by the
need to limi~ the emissions of unburned combustibles (CO, hydrocarbons and smoke)
to control operating problems, excessive vibrations, and for coal fired instal-
lations, to avoid potential slagging problems and corrosion problems due to
the reducing environment resulting from changes in combustion operation.
-------
- 62 -
5.3
"Staged Combustion"
The so-called "two-stage. combustion" technique for control of
NOx.emissions from gas and oil fired utility boilers was originally
. developed as a cooperative effort between the Southern California Edison
Company and the Babcock and Wilcox Company in the late 1950's (l). A
standardized design and operating procedure was est?blished. consisting
of firing the fuel with only 90-95% stoichiometric air, and supplying
the additional air required for burn-out of the combustibles through
second-stage IINO-portsll (air registers located ten feed above the top
row of burners). NOx emissions are reduced, because the bulk of the
combustion occurs under fuel rich conditions. and interstage cooling
minimizes further NO format{on during the second stage burnout.
x .
Use of the standardized two-stage combustion technique results
in average reductions on the order of 40-S0% in NOx compared with single
stage operation. However, test results obtained in two 750 MWgas fired.
horizontally opposed boilers indicated. even more Jramatic reductions by
admi tting air only through the top row of burners, and maintaini.\g a low
overall low excess air level of about 5% (l.l). Recent work on gas fired
utility boilers of the Southern California Edison Company (5, 6) showed that
the staged combustion principle could be further modified to reduce NOx
by "off-stoichiometric firing" of some burners fuel-rich. others fuel-lean,
or in staggered configurations of some burners supplying air only. This.
type of firing has also been called "biased firingll (JJ.
In our Boiler Test Program, we were guided by both theoretical
and practical considerations in applying lI:'!taged combustionll forNOx con-
trol. (All modifications of the standardized two-stage combustion. tech-
nique are called "staged combustion" in this report.) To assure that
. combustion should occur under fuel rich, reducing conditions, the burners
supplied with both fuel and air were opera~ed, where feasible, under sub-
stoichiometric air conditions. Also, to delay the mixing of secondary
air with .fuel rich combustion zones, our ,objective was to operate burners
on air only as close to the top row or level of burners as possible. This
was not always feasible, for the following re~sons:
o In some boilers, the operato~ determined the burner pattern
for best steam temperature control, which did not necessarily
correspond to optimum NO control (when mass flow is reduced
superheat capacity is adected). . .
. The flame monitoring system for
burners each allowed the use of
middle burners only in another,
burner cells of three vertical
"air only" operation of the
gas fired boiler tested.
. ~he maximum possible increase in fuel supply to burners
operating on both fuel and air determined the number of
burners which could be operated on "air only" under normal
full load conditions. . Otherwise, modified staged combustion
was also accompanied by a reductio~ in boiler load.
-------
- --- _.~-~~-~--.
..~--~-~-- ~ .--
" - 63 -
Wher.e the optimum configuration of opernting the top row of burners was
not possible, w~ attempted to introduce maximum separation between the
burners firing fuel. This approach allowed testing of the "staged"
combustion" approach successfully in several installations where optimum'
staging for NOx control could not be achieved because of constraints"
imposed by steam temperature control requirements.
A specific consideration in applying staged combustion operation
to pulverized coal fired utility boilers was that the staging had to be
implemented by mills, to prevent plugging of idle coal pipes. This 'olas
no handicap in the two successful sets of tests for staging pulverized
coal boilers, because the mills supplying the top row (or level) of
burners could be shut down.
5.4
Flue Gas Recirculation
Recirculation of flue gases into the combustion zone has been
shown to be an effective method of reducing NOx emissions from gas fired
laboratory and domestic size oil fired combustion equipment (1). The
reason for lower NOx emissions is two-fold: (i) the temperat~re of the
flame zone is reduced by recirculating cool flue gases, and (ii) the
concentration of oxygen available for NO production is reduced. Of these
two, the thermal effect is generally accepted to be more important (!,1).
The effect of flue gas recirculation in. stationary equipment is thus
similar to" that of exhaust gas recirculation in internal combustion
engines: lowering the combustion temperature results in lower NOx
emissions. In effect, ~ven steam or w~ter injection have been sho~rn to
have similar effects on NOx prod~ction by thermal dilution (!). The
injection of such inert diluents could not be tested in our field program
limited by the available boiler equipment, as the boilers were not equipped
for steam or water injection.
The applicability of flue gas recirculation to NOx control for
utility boilers has' been regarded as questionable by some investigators (!).
" Flue gas recirculation is a standard design feature in some utility boilers
. for steam temperature control. Commonly, the flue gases are recirculated
into the bottom of the furnace, rather than into the primary combustion
zone. " Thus, the earlier tests which measured only small, if any, effect
on NOx emissions with flue gas recirculation into the bottom of the furnace
were not considered by us to be convincing evidence for the lack of effec-
tiveness of this technique.
Since in utility boilers flue gas recirculation into the primary
combustion zone is usually not available, a special point was made in
planning the boiler test program to include measurements on such facilities.
As discussed in this report, a front wall, oil fired boiler with flue gas
recirculation into the windbox, and also a tangential, gas or oil fire"d
unit with recirculation into the combustion zone were identified, and agree-
ment of the owner-operators was obtained to measure emissions from
these boilers.
-------
- 64 -
5.5
Air Preheat Temp~rature
Since NOx emissions ,are very strongly influenced by
peak temperatures of the combustion process, any modification
these temperatures is expected to lower NOx emissions. Thus,
ai~,preheat temperature has been predicted to result in lower
the effective
that lowers
lowering the
NOx emissions
(1:.., J) .
In general, this approach is not very practical, because the
, boiler op~ratorscan vary air preheat temperature only within rather
narrow limits in existing units, without upsetting the thermal balance
of the system. Major steam side redesign would be required for effecting
large changes in air preheat temperature. However, we found it.p.ossible
in our test program to make minor excursions in air preheat temperature,
by by-passing a portion of the flow around the air heater.
5.6
Burner Tilt
Tilting burners is a design feature used in tangentially fired
boilers for superheat temperature control. This additional flexibility
in combustion operations was exploited, where possible, in planning and
conducting our Boiler Test Program.
, Varying burner tilt away from the horizontal position can to
some extent "enlarge" or "constrict" the effective furnace combustion
zone. Thus, depending on flame patterns and transport effects, a longer
effective residence time may be available,for NOx formation, or conversely,
a lower combustion intensity may prevail in the enlarged combustion zone,
leading to lower NOx emission's. The firs.t one of these two alternatives
was expected to be more likely because of the diffuse, swirling fireball
pattern prevailing in tangentially fired boilers.
5.7
Other Modifications
In addition to the comb.us,tion, op.erating .variables discussed
above, the effects of some other variables were also explored inasmuch
as possible with the boilers tested. One example of this type'of
"opportunistic" approach was to vary the primary to secondary air ratio
in the burner air supply. Restricting the flow of air through the
secondary air regis ters increases turbulence in the flame, resul.ting in
more intense combustion conditions, which can lead to somewhat higher.
levels of NO emissions. Although it was recognized at an early stage
of the program that burner configuration could have' a maj or effect on NO
emission, a systemati,: exploration of this factor was beyond the scope of
our study.
In summary, it must be emphasized that while the selection of
combustion operating modifications for NOx control was made based on
considerations of known theoretical and practical factors, the actual
detailed implementation of the program plans had to be adapted to particu-
lar set d2sign and operating features of .each b6iler tested. Details of
the results obtained in this study on exploring combustion modification
techniques, individually, or in combination with one another, are presented
in the following section of this report.
-------
- 65 -
6.
RESULTS OF THE BOILER TEST PROGRAM
As discussed in Section 4.1 of this report, a statistically designed
'field test program was conducted to measure NOx and other emissions from
utility boilers. Details of the experimental approach taken included the study of
a representative sample of U. S. fossil fuel power boilers according to
fuel type, boiler size, method of firing, flexibility for combustion
operating changes, geographical location, and being representative of
current design practices of manufacturers.
Features of the Esso Research sampling-analytical van including
the description of the equipment and a discussion of the sampling and
analytical procedures used in the Boiler Test Program have been discussed
in Section 4.2. '
Our prime objective in the Boiler Test Program was to assess
the scope of applicability of combustion modification techniques limited
by the design and operability of representative boilers for the control of
NOx emissions. Since such combustion modifications may lead to adverse
effects on the emissions of other pollutant species, such as CO, hydrocarbons
and other unburned combustibles, our approach was to continuously monitor
the concentrations of CO and hydrocarbons during the test runs, as well as
visually observe the condition of the stack plume for haze or particulate
emissions.
, , Another i::1port~nt c,oro1.lary of effecting cC:l:.bustion operating
changes for NQx emission c9ntrol is the 'potential impact on boiler
performance. It was not possible within the scope of this study to
optimize the performance of the boilers tested in a detailed manner; but
rather" we ~ave worked very closely with the operating personnel of the
cooperating utility companies to gain information on gross changes that
might have occurred. For three of the.coal fired boilers, however, the
respective boiler manufacturers participated in the test programs
(Babcock and Wilcox at Boiler Q, Combustion Engineering at Boiler 0, and
Foster-Wheeler at Boiler N). The role of the boiler manufa~turers was to
give us and the operators guidance on the limits of flexibility in operating
the boilers, to ascertain whether the boilers were in normal operating
condition, and to obtain detailed steam side data for the characterization
of boiler performance corresponding to the emission test conditions.
A natural consequence of the systematically designed boiler
test' program was to obtain base-line emission data on NO, NOZ, CO and
hydrocarbons in addition to the usual constituents of the combustion
flue gases. . Test runs under base-line boiler operating conditions
were necessary for comparison of the emission levels obtained via
combustion modifications with standard practices. As a result of
these tests, we were able to accumulate reliable emission data on boilers
of different design types (wall fired, tangentially fired, cyclone fired,
and vertically fired) using gas, ofl, and coal fuels. Thus, by measuring
-------
66 -
base line emissions on the 17 boilers tested (25 boiler-fuel combinations),
adequate information was generated to establish improved emission factors for NO ,
CO and hydrocarbons in power generation. This is useful information, x
th" ".. f d .
as e average em1SB10n actors use 1n the past are clearly not aoolicable
to individual. units (!), (.!!), and a definite improvement has been mad~ on"
this problem in this study.
The best way to characterize the nature of our boiler test
program is to call it "exploratory" in natu!='e. Because of the scarcity
of information available on NOx emission control for utility boilers
. ,
it was deemed necessary to obtain such information on as many units
as possible within the contractual period. As a consequence, we did not
attempt to optimize, or "demonstrate" the feasibility of NOx emissions
by combustion modification techniques, but rather, to explore the broad
limits of emission control attainable with different firing patterns, in a
variety of boilers for all three fossil fuel types. Furthermore, in exploring
the effectiveness of combustion operating changes, we paid particular attention
to the definition of potential problem areas, ~uch as slagging, corrosion, flame
lift-off and impingement, and safety considerations. The sum total of the informa-
tion gathered proved to be necessary for establishing what the future direction
should be for the application of combustion modifications for pollutant emission
control, and in addition, what design changes may be required for reducing NO
emissions to minimum levels. x
Significant progress was achieved on a systematic basis in the
course of the Boiler Test Program on the control of NOvemissions from boilers.
As will be discussed, the results indicate an excellent potential for emis-
sion control for gas fired boilers, promising, but somewhat less effectiv.e
control for oil fired boilers, and a major remaining problem area for the
control of NO and other pollutant emissions from coal fired boilers.
x .
The results of our Boiler
of this report, organized according
of boiler firing methods studied.
Test Frogram are discussed in this section
to fuel type and corresponding to the types
6.1
Boiler Designation and Description
Design characteristics of the 17 boilers tested for NOx emission.
control in the Boiler Test Program are summarized in Table 6-1. This table
lists for each boiler coded in alphabetical order the general design informa-
tion (e.g., full load rating, type of firing, fuels burned, manufacturer,
etc.), specifics of the .furnace design (e.g., furnace volume and heating
surface, number and configuration of burners, etc.), 'and availability of NOx
emission control equipment (e.g., NO-ports, flue gas recirculation, etc.).
-------
~.U.:!.
SUMMARY OF BOILER. D.ES IGN INFORKATION
Design
Characteristics -L.. B C D -L -L- -L ----!L -L ---1L- ...1...- M -1L -L P. ..-JL
~ 3.
t. Maximum Cont. Rating ~O lb.
steam/hr.) 1,200 810 1,900 2,060 3,316 4,000 1,638 2,305 680 1,900 620 2,450 1,000 5,280 3,850 2.750 4.900
2. Full load rating - MW 180 80 315 350 .480 600 220 . 320 66 250 66 450 175 820 575 300 704
3. Type of firing F.W. F.W. F.W. H.O. H.O. H.O. A.W. T V F.W. T CY F.W. H.O. T T CY
4. Manufacturer C.E. R F-W B6M B6M F-W B.5
-------
- 68 -
6.2
Individual Emission Results on Gas Fired Boilers
Test programs were run on eight boilers firing gas: three front
wall fired, three horizontally opposed fired, one "all-wall", and one vertically
fired boilc~. A tangentially fired boiler which was tested on oil firing was
also scheduled for gas fifing. However, abnormal weather conditions and local
gas shortage at that time forced us to cancel the scheduled gas fired program.
Fortunately, the boiler operator-owner has kindly supplied their own represent-
ative emission data over a variety of operatin~ conditions on this bdiler. Thus,
our total sample covers nine gas fired boilers ~nd 79 test runs.
6.2.1
Front Wall Gas Fired Boilers
Boilers A, B, and C are front wall fired boilers built by Combustion
Engineering, Riley Stoker} and Foster-~~eele~ rated at 180, 80 and 315 ~n~, gen-
erating capacity, respectively. The experimental procedures and results for
Boiler A are presented in some detail. Only the highlights will be discussed
for the other two boilers since the same principles and approaches were used.
For Boiler A, the test program design shown in Table 6-2 was developed
according to sound statistical principles. All of the major operating vari-
ables (load, excess air level,and staging) were varied in accordance with ~ par-
tially replicated factorial design so that the response to each major factor
and the 'interactions between factors as well as experimental error could be
measured independently with maximum efficiency. Other major design features
such as "NO-ports", flue gas recirculation into the wind box, tilting burners,
etc. were not available with boiler A. The levels of each factor were set at
the extreme limits of their practicF!1 ape!"~ting rfl.nge.. R~plicate runs (on' dif-
ferent days) were made at full load at all four combinations of excess air and
staging so that a pure measure of repeatability or experimental error could' be
obtained independent of higher order interactions. In addition, independent
analysis of NOx' 02 and C02 were I1]ade by the boiler operator for comparison to our
measurements. Loaas were set at the highest (full load) and low~st (120 ~M)
operating levels, with all 16 burners in use. An additional low load level
(70 ~) was provided (at the lo,.,est efficient load using 12 burners) so tha't
any non-linearity of emissions with load could be determined. At full load, the
lowest permissible level of excess air was determined by limiting CO emissions
to increase to a maximum of about 200 ppm. At the lowest load, flame stability
determine~ the lower limit of excess' air. The staging patterns set for each
loadwere'based upon extensive plant experience to reach a balance between reduction
of NOx and CO emission with adequate steam temperature control. Table 6-2 summarizes
the NOx emissions measured on the basis of the test program design. "
TABLE 6-2
BOILER A EXPERU!ENTAL DESIGN 00 GAS FIRED
(Average .NOx Emissions, ppm @ 3% 02' Dry Basis)
(Ll) 180 ~ (L2) 120 MW (L3) 70 ~
Hi Air Lo Air Hi Air Lo Air Hi Air Lo Air
81 Normal Firing , 387 ~ 331 @ 230 (j) 188 @ 116 @ 108
. 393 334
--.-..--.-.. h___~_.~
S2 Staged Firing (ID 195 (5) 156 @ 133 @ 88 Q) 81 @ 66
I 6)' 201 G 155
'-
. "t:ircled numb~rs indica te run numbers.
-------
TABLE 6-3
SUMMARY OF EMISSION DATA FROM BOILER A (180 MW, FRONT WALL, GAS FIRED)
- Opera tine: Data
Boiler . Flue Independent
Gross Steam Fuel Gas Staged No. 0 Burners Ave. F1ue Gas Components (1) Gas Ana 1 vs is (4)
Run Load Flow Flow Excess Firing Air % Dr Basis 370 0, Drv Basis - PDm Temp. % ppm
No. 0.1\.1) 103 1bs/hr 103 Ft3/Hr ~ir (1) (2) Fir 1n2 On1v u2 CU2 NUx CO HC of 02 CO, NOx
1 70 420 650 Hi yes 10 2 2.88 10.3 81 16 -- 630
2 71 420 650 Lo no 12 0' 1.23 11.3 108 13 -- 626
3 119 740 1060 Lo no 16 0 1.05 11.5 188 17 -- 663
4 120 744 1020 Hi yes 12 4 3.08 '10.6 133 15 < 3 658 2.9 10.1 125
5 182 1225 1520 Lo yes 12 4 ; 1.68 11.5 156 20-100 <1 711 1.2 11.1 136
6 182 1225 1530 Hi yes. 12 4 3.23 10.8 195 16 <1 712 2.8 10.5 ,192
7 180 1220 1540 Hi no 16 0 2.78 11.0 387 14 <1 718 2.2 10.8 357
8 181 1235 1540 to no 16 0 1.15 12.0 331 18-150 <1 714
9 70 420 620 Hi no 12 0 3.05 10.4 116 13 <1 612
10 70 420 620 LO yes 10 2 1.70 11.1 66 21-140 <1 612
11 121' 760 1030 LO yes 12 4 1.13 11.4 88 20-200 <1 650
12 122 760 1030 Hi no 16 0 2.35 10.8 230 15 <1 670
13 179 1220 1570 LO no 16 0 1.05 7.9 334 17-90 <1 712
..14 181 1220 1530 Hi no 16 0 - 2.75 10.6 393 14 <1 720
15 180 1220 1530 Hi yes 12 4 3..08 10.5 201 15 <1 716
16 180 1220 1530 LO yes 12 4 1.68 11.3 155 15-85 <1 708
'"
-.0
(1) Test program design.
(2) Burner Patterns: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
A 0 0 A 0 0 0 0 A O. 0 A 0 0 0 0
XXX X XXXX OAAO 0000
000 0 0 0 0 0 0 0 0 U 0 0 0 0
Staged: Yes No Yes No
Load: 70 MW 70 MW 120 MW and 180 MW.
(3) *Average of 16 Data points per run. Each data point from a:composite
(4) Average of 3 samples by PDS or Orsat Analysis~ .
Key:
o - Firing Fuel
A - Air Only
X - No Air or Fuel
of 3 gas sample streams.
-------
- 70 - .
Table 6-3 presents a summ'ary of emission and operating data for
each of 16 runs made on Boiler A. Table 6-4 and Figure 6-1 present the
detailed NOx emission test results. Uncontrolled, ful,l load NOx emissions
averaged 390 ppm (3%, 02' dry basis). Reducing load by one-third (120 ~M)
resulted in a 41% reduction in NOx' while a 60% reduction in load (70 MW)
resulted in a 70% re.duction in NOx emissions. The application of low excess
air at full, 67%, and 40% load reduced NOx emissions by 49, 42, and 30%,
respectively, while the combination of low excess air and staging reduced
NOx emissions by 60% at full load, 52%. at 67% load, and by 43% at 40% load,
compared with uncontrolled emissions at each of these loads.
TABLE 6-4
BOILER A - GAS FIRED
NO REDUCTION THROUGH COMBUSTION CONTROL
-x
Load Combustion Control
MW % Reduction None . Staging LEA + Staging
Low Exce\ss Air
180 390 ppm 0% 332 ppm 15% 198 ppm 49% 156 ppm 60%
.0% 0% 0% 0% 0%
120 230 ppm 0% 188 ppm 18% 133 ppm 42% 88 ppm 52%
33% 41% 43% 33% 44%
'70 'I 116 ppm 0% 108 ppm 7% 81 ppm 30% 66 ppm 43%
61% 70% 67% I 59%, 58%
Analysis of variance summarized in Table 6-5 indicates quanti-
tatively the significance of each of the main factors and their inter-
actions.
TABLE 6-5
BOILER A - GAS FIRED
ANALYSIS OF VARIANCE
Degrees of I Mean F FO.001
Source 0 f Va r ia t ion Freedom Square Ratio
1. Load 2 31,564 1,973 22
2,. Excess Air 1 3,710 232 29
3. Staging 1 34,454 2,153 I 29
4. Load x Air Interaction 2 ,432 I 27 I 22
I
5. Load x Staging I 2 5,385 I 337 22 I
I I
I I
6. Excess Air x Staging {~ {3~ I
I : ' , I
7. Load x Air x Staging I 7 116 I I
. I
i j i
f 10 I
8. Repeats I !,
! : \
i I i I.
I
15 ! -- -- i I
I
9.
Tot~l
-------
500.
Figure ~-1
NO EMISSIONS FROM BOILER A
x .
(180 MW, Front Wall, Gas Fired)
-Circled numbers
denote run numbers.
400
II)
II)
n:s
co
>.
'"-
Q 300
..
N
0 I
~ "
('() I-'
......
n:s
E 200
c..
c..
..
X
.0
2
100 Normal Firing
Staged Firing
o
o
25
50
75 100 125
Gross Boiler Load, MW
150
175
200
-------
TABLE 6-6
SUMMARY OF EMISSION DATA FROM BOILER B (80 MW, FRONT WALL, GAS FIRED)
Operating Data Gas Components(2)
Boi 1er ! No. of Ave. Flue Flue
Gross I Steam Fuel Staged ---1~urners % ppm Gas
Ruri Load Flow Gas Flow Excess Firing Air Dry Basis 3 % 02, Dry Basis Temp.
No. MW 103 Lb/Hr 103Ft 3/Hr Aidl \ (5) Firj~ng Only °2 C02 NOx CO HC(~) of.
-
9 20.5 I 175 240 Low Yes 10 2 3.50 10.0 65 60-360 <1 565
10 20.5 175 240 Normal I No 10 o . 4.65 9.1 90' 52 <1 519
I
11 49.5 I 425 (..3) 626
540 Low No 12 0 2.03 10.4 170 <1
12 50.0 425 538 Normal Yes 10 2 5.08 8.7 200 63 <1 640
I 81.5 I 789
13 740 900 Normal Yes 1C 2 5.03 8.6 3761 56 <1
I . .
, I
14 81.9 740 890 i Low No 12 0 2.59 10.3 421 68-185 <1 763
15 81.5 740 900 ' 10 2 2.80 9.9 311 108-370 <1 784
t Low I Yes
t I
:
I
16 82.0 740 900 i ! 12 0 4.18 9.5 497 52 <1 778
Normal! No !
.
.....,
N
(1) Test program design.
(2) Average of 16 data points per run.
(3) Not measured.
(4) Excluding hydrocarbons co~lected in condensate.
(5) Burner patterns:
Each data point from a composite of 3 gas sample streams.
Staged
Load
OAOOA,O
000000
Yes
20 MW
OEOOEO
000000
No
20 HW
OAOQA.O
OPOOOO
Yes.
50 MW
000000
000000
No
& 80 MW
o = Fuel and air
A = Air only
N = Burner out of s~rvice
-------
- 73 -
The estimated experimental error from the repeated. full load
test is equal to 3.2 ppm NOx (~= 3.2). Combining the sum of squares
for the nonsignificant (excess air x staging) and (load x excess air x
staging) interactions with repeats results in a revised estimated experi-
mental error of 4 ppm NOx (J16 =.4), with 7 degrees of freedom. This
revised estimate of error was used in testing the significance of the
three main effects and the remaining two-factor interactions. All are
highly significant (p < 0.001), with staging and load accounting for most
of the variation in NOx emissions.
Ninety-five percent confidence limits can be estimated for each
of the test runs by adding and subtracting 8 ppm (j: t.055 = t 1.90 x 4.0 =
+ 8). As discussed before, detailed analysis of the results obtained in
testing Boiler A is shown in order to demonstrate that the. point estimates
presented in Table 6-2 and plotted in Figure 6-1 are highly significant
and that summary tables such as 6-3 do show real differences.
co emissions averaged between 13 to 17 ppm except when low excess
air was applied at higher loads. The inherent cycling of fuel and air with
automatic controls resulted in a range of CO values at low excess air. Thus,
a slight reduction in excess air below a critical level could result in
. greatly increased CO emissions. Individual-probes gave widely different
. results as the average level of excess air was reduce~ indicating that some
individual burners produced high CO values. Hydrocarbons consistently
measured less than one ppm. -
Table 6-6 presents a summary of operaLing anu emission data obtained
from Boiler B~ firing gas. The statistical design including the corresponding
NOx emission results is shown in Table 6-7. A full factorial design was run
at full load while a fractional factorial (two level, latin square) was run at
intermediate and low loads. Thus, all 8 runs were made in one day of testing
with emphasis on full load runs. Figure 4-2 presents the NOx data obtained
from this boiler in graphical form.
TABLE 6-7
BOILER B EXPERI~lliNTAL DESIGN - FIRING GAS
(Average NOx Emissions,ppm at 3% 02' Dry Basis)
Ll (82 MW) L2 (50 MW) L3 (20 Ht-!)
Al (Normal) AZ (Lo Ai r) Al (No mal) A2 {Lo Air) Al (Normal) A2 (Lo Ai r) .
S 1 (Normal "1<'i !'ing) @'497 @ 421 @ 170 @ 90
S2(Staged Firing) @ 376 @ 311 @ 200 @ 65
* Circled numbers denote run numbers.
-------
500
.~ 400
V)
rtS
cc
>-
~
. Q
...
. ON 3~0 .
~
('/'\
..... .
rtS
E
a.
.~ 200
x
o
2
100
o
o
. - 74 -
Figure 6- 2
NOx EMISSIONS FROM BOilER B
(80 MW, Front Wall, Gas Fired)
Circled numbers
denote run numbers.
Normal
Firing
100
80
Gross Boiler load, MW
-------
- 75 -
Uncontrolled, full load.NOx emissions averaged about 500 ppm. This
relatively high level for a small boiler (80 ~fiv) is probably due to the rela-
tively close spacing of the 12 front 'wall burners as discussed more fully in
section 2.3. However, significant NO emission reductions were obtained
through combustion control. ReducingXload by 76% to 20 ~nv reduced uncontrolled
emissions by 82% and "fully controlied "emissions (low excess air plus staging)
by 80%. An estimated standard deviation for experimental error of 5.5 ppm NOx
was calculated from the full factorial results. This compares with 3.2 ppm for
boiler A. At full load, the application of low excess air, staged firing, and
the combination of low excess air witp staged firing reduced NOx emissions by
15%, 24%, and 37%, respectively. Table 4-8 summarizes these and other compari-
sons on NO emissions for this boiler.
x .
TABLE 6-8
BOILER B - GAS FIRED
NOx REDUCTION THROUGH COMBUSTION
CONTROL
Load Combustion Control
MW % Reduction None Low Ex'ces s Ai r Staged Fi ring LEA Staging
82 497 ppm 421 ppm 15% 376 ppm 24% 311 ppm 37%
0% 0% 0% 0% 0%
50 240 ppm * 170 ppm 29%* 200 ppm 17%
39% 52% 60% 47%
-
20 90 ppm 65 ppm 28%
76% 82% .' 80%
-- '---~---_.' ----- .Q_.--!
* Estimated value to provide basis for comparison.
Due to the limited time available for testing this boiler, only
the staged firing pattern**, shown below, was applied:
OAOOAO
000000
Where:
A - Air only
o - Air and Fuel
However, the following staged firing patterns would be likely to result in im-
proved NOx emission performance if the boiler could be modified to achieve full
load with four to six burners on air only. Other firing patters of interest
may include the following which would tend to delay mixing of the air with
fuel. and prevent excessively high NOx and CO emissions:
OAOOAO
OOAAOO
or
OAOAOA
AOAOAO
Additional experimentation is needed to optimize this boiler from the standpoint
of NOx emission, control. In principle. mixing of air and fuel is delayed
best by imposing a maximum possible separation between the "on air only"
burners, but this objective may entail other emission or operating problems.
**
B~sed on prior experience of the utility owner-operator.
-------
- 76 -
Table 6-9 presents a summary of operating and emission data obtained
from Boiler C. This twin furnace boiler has a capacity of about 315 ~~. The
superheater furnace (from which emissions were sampled) provides about 55% of
the boiler heat release at full load and 50% at one-half load. Uncontrolled,
full load NOx emissions were 990 ppm; These high emission levels (confirmed
on coal and combined coal-gas firing) are likely to result from the particular
design features of this boiler. Originally, this boiler was designed to burn
coal and to maintain a wet bottom (molten slag) under low load firing. Thus,
the twin furnaces were designed with the bottom row of burners close to the
flat floor of the furnace. In addition, the bottom and sides of each furnace
up to the top row of burners are insulated so that-slag is maintained in the
molten state. These design features result in relatively lo\v heat absorption
rates, and therefore high flame temperatures and high NO emission levels.
x
A 41% reduction of load resulted in a reduction of 47% in NO
emissions. Partial staging (firing fuel lean on the top row of burner:
and more fuel rich on the bottom two rows), combined with low excess a-ir
at 29% reduced load resulted in a 48% reduction in NOx emissions. Only
very limited data could be obtained on emissions from this boiler because
of boiler operating difficulties.
-------
- 77 -
'i.
. TABLE 6-9
ens MW Front Wall c'as Fired'
.Average-Flue. --=1
Operating Data Gas Components
3% 0
- Dry2
Fue 1 Gas Bas is
Run Furnace Load Flow Staged Dry Basis NOx Flue Gas
No. (MW) (2) 106 ft 3/hr. Firing (3) Excess Air O? (%) CO? (%) (PPM) Temp. of
1;3 157 1.46 No Low 2.4 16.6 931 649
I
14 155 1.46 No High 4.5 9.2 992 648
!
15 93 0.83 No Low 4.4 9.1 529 532
16 . 93 0.83 No High 6.4 7.4 ' 515 588
17 /111 1.04 Yes Low 2.9 9.8 515 620 I
1.05 Yes High 4.6 8.9 -',",
18 112 {bt; -""r- i
SUMMARY OF EMISSION DATA FROM BOILER C
(1)
(1) Measurements on one of twin furnaces.
(2) Total turbine MW generated is about double this number.
(3) Staged firing: No - equal fuel rate on all 3 rows; Yes - fuel lean on top
row (20% 'of total fuel) and rich on middle and bottom rows
(40% of total fuel).
. .
-------
TABLE 6-10
SUMMARY Of EMISSION ;)ATA FROM BOILER D
(350 MW, Horizontally Opposed, Gas Fired)
Operating Data . Ave. Flue Gas Compon,=nts
'
Total
Gross Steam Fuel 3% 02. Drv Basis F1 ue Gas
Run. Load - . Flow Gas E xce s s "NO-. 1 Staging 02 CO2 Temperature
No.. MW 106 1b/hr 106ft3/hr Air(l) Ports" (2) % % NOx. ppm CO. ppm of
1 355 2.13 2.93 Low . Shut Yes 1.5 11.1 355 105-195 693
2 357 2.15 2.93 Low Open Yes 2.0 10.6 213 100 -185 693
3 355 2.15 2.93 Low Open No 1.9 10.7 381 84 692
4 355 2.15 2.93 Low Shut. No 1.6 10.8 783 74 692 .
5 356 2.15 2.95 Hi Shut No 2.6 10.2 946 86 693
6 355 2.15 2.94 Hi Open No 2.8 10.0 515 67 695
11 356 2.15 2.95 Hi Open Yes 3.4 9.6 275 75 701
17 153 0.95 1.39 Low Shut No 1.3 11.2 249 57 631 .
18 153 1.00 1.39 Low Open Yes 2.1 10.8 56 76 621
14. 152 0.95 1.37 Low Open Yes -2.1 10.6 72 68 566
16 152' 0.97 1.38 Low Shut No 1.7 10.7 299 64 576
15 152 0.95 1.37 Low Open No 1.7 10.5 165 74 598
13 152 0.95 1.36 Low Shut Yes 1.7 10.7 87 54 593
19 151 1.00 1.35 . Low Open Yes 1.7 10.5 75 .59 594
20 153 1.00 1.36 Low Shut Yes 1.6 10.6 121 192 601
(1)
(2)
II] [} [1
[] [U [J
3-burner cell
Test program design.
Staging: No - All 24 burners firing gas equally.
Yes - Top burner in each 3 upper burner cell
on air only, except for Runs 19 and 20
in which middle burner in each upper
cellon air only.
Burner Configuration
-...J
00
I.
-------
- 79 -
6.2.2
Horizontally Opposed Gas Fired Boilers
Boilers D, E and F are horizontally-opposed fired boilers. Boiler G
is an unusual "a1l-wa11" fired boiler which was fired during our test program in
several modes including, horizontally opposed firing and, therefore, will be
discussed with this group of boilers tested.
Table 6-l0presents a summary of emissions from boiler D with gas
firing. The primary operating variables included in the statistically planned
experimental program were load, staging, excess .air and "NO-port" setting
(open or closed). The staging pattern which had demonstrated the lowest NOx
emissions with safe operating conditions from prior test runs conducted by the
boiler operator was used, i.e., the top burner of each upper 3 burner cellon
air only, as show~ in Table 6-10. To obtain an independent check on this
stag'ing pattern, t\-lO :::-uns (19 and 20) were made with the middle burner of each
upper cellon air only. "Normal" flue gas recirculations (for steam temperature
control) was used in all runs, except in runs 17 and 19 were there was maximum
flue gas recirculation into the bottom of the furnace. Because of the shortage
of gas fuel, six originally planned test runs had to be omitted. The
statistical design and the corresponding NOx measurements are shown in
Table 6-11.
TABLE 6-11
BOILER D EXPERIMENTAL. DESIGN - FIRING GAS
(Aver8ge NOx F.missions,
r'pm at
~"I n~
--.,) 'oJ ~ ,
Dry Basis)
A2 High
Excess
Air
Stage
Fi rin
Norma
Firin
Stage
Fi ri n
Norma
Firin
2 .(150 MW)
Al Low
Excess
Air
783 .
FGR
72
75
165
. "NO-Ports "Closed
Max. FGR Min. FGR
87
121
299
946
Note:
Circ led numbers denote run numbers. Staged firing: top burner on .
air only except for Runs 19 and 20 with middle burner on air only.
FGR = Flue gas recirculation for steam temperature control (i.e., into
the. bottom of the furnace).
-------
- 80 -
Table 6~10and Figure 6-3 s~arize the effects of changing operat-
ing variables on NOx emission rates for this boiler. Full load (350 MW)
operation with no combustion controls applied resulted in 946 ppm NOx (corrected
to 3% 02' dry basis). Low excess air at full load reduced NOx emissions by
21% (Runs 1, 2 and 3 vs. 5, 6 and 11). Opening the "NO-ports" which were
designed specifically to reduce NOx emissions resulted in about 50% reduction'
in NOx at full load, (Runs 2, 3 and 6 vs. 1. 4 and 5) and about 40% NOx re-
duction at reduced load (Runs 14, 15 and 19 vs. 13, 16 and 20). It should
be noted that under normal operating conditions, the "NO-ports" of this boiler
are kept closed at reduced load. Staging reduced NOx emissions by 50% at full
load (Runs 1, 2 and 11 vs. 3, 4 and 6) and by 65% a t reduced loa'd
(Runs 13 and 14 vs. Runs 15 and 16). Maximum flue gas recirculation (Runs 18
and 17) resulted in a NOx reduction of about 20% compared to no flU9. gas re-
circulation (Runs 14 and 16). The effect of changing the staging pattern
from "top burner-air only" to "middle burner air-only" increased NOx emissIons
by about 20% (Runs 19 and 20 vs. Runs 14 and 13). The combinations of low
excess air, staging, and keeping "NO-ports" open reduced NOx emissions by
almost 80% at full load (213 ppm vs. 946 ppm). The combination of staging,
"NO-ports" open, maxi.mum flue gas recirculation, and low excess aj r resulted
in over 80% lower NOx emissions than using only.lmV' excess air at reduced
load. The recirculation of flue gases into. the bottom of the furnace pro-
duced an 18% reduction in NOx emission (Runs 17 and 18 vs. 16 and 14). Reduc-
ing load by 57%, reduced NOx emissions by an average of 64% (Runs 1, 2,' 3 and
4 vs. Runs 13, 14, 15 and 16). Table 6-12 presents a summary of' the measured
reductions in N9x emissions.
co emissions avera~~d 70 ppm, e~cept
where CO emissions as h~gh as 195 were recorded
fOT ~ few low exce~s
air runs
from Boiler D.
Table 6-13 presents a summary of emissions data from Boiler E,
firing gas. Boiler E is equipped with 8 "iW-ports" for reducing NOx
emissions. In addition, the top burne= of each two upper burner cells
has its gas line sea led closed, with its a ir ducts open as shown in
Table 6-13. Thus, this boiler always uses staged firing when burning gas,
and it could not be tested under a firing configuration without staging.
(Emission data were obtained trom the operator on the conditions which
prevailed before this change).
The operating variables included in the single re~licated,}actoria~
design were load (450 and 220 MW), excess air (normal and h1gh) and _NO-ports
(open or closed). Table 6-14 and Figure 6-4 summarize the e.ffects of chang-
ing operating variables on NOx emission rates for boiler E. Full load N~x.
emissions without combustion controls were only 236 ppm due to the benef~c1al
effect of staged firing.
Analysis of variance for boiler E indicates quantitatively the
significance of the NOx reductions found, as shown in Table 4-l4A.
, .
The three-factor interaction mean square provides an estimated
standard deviation for experimental error equal to 4.2 ppm NOx (-{l8 = 4.2),
with one degree of freedom. This estimate agrees well \.,lth the standard -
deviation for. experimentaJ error calculated from boiler A replicated runs of
3.2 ppm NOx, 'and 5.5 ppm NOx for boiler B.
"
"....,
-------
900
800
700
,~ 600
VI
rt!
I:C
>-
....
c
"'.. '500
N
o
~
('t)
....
rt! 400
E
a.
a.
..'
x
o
:2 300
200
100
o
O'
- 81 -
Figure 6-3
NO EMISSIONS FROM BOilER D
x
(350 . MW, Horizontally Opposed, Gas Fired)
Circled numbers
denote run numbers.
.::-
./J
~
't
I
. 0
~
..
e
H iN'h /1'1'"
. ~: I~.'
low Air
low Air
Normal
Firing
low Air
Sta~ed
Firing
100
200
300
. 400
500
Gross Boiler -toad.
"
-------
- 82 -
TABLE 6-12
BOILER D - GAS FIRED
NOx REDUCTION THROUGH COMBUSTION CONTROL.
Load Combustion Control
Low Open Full
MW % Reduction None Excess Air 'NO-Ports" Staging FGR Cant rol"
350 946 ppm-O% 21% .47% 50% 77%
0% O~
-
150 341 ppm41. 39% 66% 20% 81%
57% 64%
* Estimated to provide basis for compar~son.
-------
TABLE 6-13
SUMMARY OF EMISSION DATA FROM BOILER E
(450 MW, Horizontally Opposed, Gas Fired)
Operating Data Ave. Flue Gas Components
r'uel
Gross Gas Flow Excess No. 0 f Drv Basis 3% 02. Drv Basis F1 ue Gas
Run Loacf 106Ft3 NO- Air Burners. 02 CO2 Tempe rat ure
No. (MW) Hr. Ports Level (1) Fid ng % % NOx. DDm CO. ppm of
8 227 2.20 Closed Normal 24 3.0 10.1 120 15-70 509
5 227 2.15 Open Normal 24 2.9 10.0 70 20-1000 510
6 225 2.11 Open High 24 4.5 8.9 95 15 511
7 227 2.15 Closed High 24 4.5 8.9 166 15 508
..
3 448 3.65 Closed High 24 4.0 9.6 236 12 624
2 443 3.65 Open High. 24. 4.0 9.6 145 13 628
1 443 3.65 Open Normal 24 3.0 9.8 140 20-400 624
4 443 . 3.65 Closed Normal 24 3.0 9.8 198 61 621
I
~
l..>
(1)
(2)
Test program design
Average of 16 data points per run.
Each data point has a composite of 3 gas sampling points.
.., - -
~ ~ [fJ.[fJ
~~
~urner Configuration
~rontand Rear Furnace Faces)
~
I ~ I
-------
- 8f. ...
TABLE 6-14
BOILER E - GAS FIRED
NOx REDUCTION THROUGH COMBUSTION. CONTROL
Load Comb us tion Control (In Addition to Staged Firing)
Low Open . LEA +
N1~ % Reduction None Excess Air NO-Ports NO -Ports
450 236 ppm-O% 198 ppm-16% 145 ppm-39% 140 ppm-41%
0% 0% 0% 0% 0%
220 166 ppm 120 ppm-28% 95 ppm-43% 70 ppm-58%
51% 30% 39% 35% 50%
-------
300
ell
ell
!U
ca
>.
,.,.
CI
.. 200
N
a
~
('('\
~
!U
E
a.
a.
..
x
a
z 100
o
o
- Circled numbers
denote run numbers.
100
Figure 6-4
NO EMISSIONS FROM BOILER E
x
(480 MW, Horizontally Opposed, Gas Fired)
"NO-Ports"
C I 0 s ed
"NO-Ports"
Open
. ~\'(
t.~cess
\\\q" . .
200 300
Gross Boiler Load, MW
400
.Q:)
V1
500
-------
- 86 -
TABLE 6-14A
BOILER E - GAS FIRED - ANALYSIS OF VARIANCE OF NO
x
EMISSIONS
Degrees of Mean F
Source of Variation Freedom Square Ratio
1. Load 1 8978 126(b)
2. Excess Air 1 1624 23(a)
3. 1'NO-Ports II 1 .9112 128(0)
4. (Load X Air) I.nteraction 1 98 1 4 (e)
5. (Load X Ports) Interactionl 1 98 . (e)
6. 1 364 1.\d)
(Air X Ports) Interaction 5.1
7. (Load X Ai r X Ports)
Interaction 1 18 (71. 3, d. f. = 3).
8. Total 7 20292
(a) significant at .the 5% level (F.05 (1,3) = 10.1)
(b) significant at the 1% level (F.01 (1,3) = 34.1)
(c) revised estimate of experimental error (98 + 98 + 18)
. (d). possible significance, F.10 = 5.S
(e) not significant
+ 3 = 71.3
-------
~ 6-15
SUMMARY OF EMISSION DAJ:A FROM BOILER F. (600 MW, ,HORIZONTALLY OPPOSED, GAS FIRED)
Average Flue Gas Components and TemDeratures (2)
Operating Conditions Duct Number 21 Duct Number 22
i---. .'-""-- NOx (ppm) NO.... (oDm)
. Gross No. of
Run -Load Burners Staging '02 3% 02. C02 CO Temp. 02 3% 02 C02 CO Temp.
No. MW Firinsz. (1) % Drv Basis % ppm of' % nrv R':'o.f", % DDm of
1 554 24 No 3.1 571 7.9 7 633 1.2 478 8.8 8 600
2 563 24 No 3.5 510 1'.8 8 643 2.3 542 8.4 8 610
3 415 24 No 4.1 345 7.6 13 566 3.0 339 8.2 14 545
I 4 406 24 No 2.5 314 8.3 5 530 1.2 271 9.1 5
I --
I 5 325 24 No 2.3 225 8.6 9 513 1.2 185 9.2 10 --
6 326 24 No 4.0 ;:53 9.1 20 525 .2.7 239 9.9 20 --
7 327 16 Yes 4.4 120 9.3 3 535 3.1 88 10.0 4 --
8 324 16 Yes 3.2 109 9.9 4 520 1.6 '79 11.0 10 --
9 322 16 Yes 2.6 105 10.3 -- 520 1.1 77 11.2 -- --
........... ......'-_..~ ..---:;:...,'.. - Y?--"'Wo' ..---..-.... --.
I
'00
--.J
. I
(1)
Staging:
no, a.11 burners firing equal amounts of fuel.
yes, top row of burners on air only.
(2)
Average of eight composite samples 'of 3 gas streams at actual stack conditions.
Note:
Computer results on periodic tests: ,
Fuel rate (106 ft.3/hr), run 1:5.12; run 2:5.22; run 3:3.81; run 7:3.07 and run 8:3.04.
Heat rate (BTU/K\'ffi), run 1 :9,834:; run 2 :9,875; run 3 :9,824; run 7:10,077 and run 8 :10,088.
(heat rate 11-13% above design heat rat(~ due to high pressure heaters out of service, and
other facto,rs) .
-------
- 88 -
co emission levels were low except for Runs 1 ahd 5 whe re 400 to '
1000 ppm levels were reached. A slight increase in excess air is expected
to reduce these high CO emissions levels with very little increase in NOx
emission rates.
Table 6-15 presents a summary of emission data from BoiLer F.
This boiler has two separate ducts leading from the economizers to the air
heaters. Our flue gas samples were taken from two probes (3 sampling points
per probe) inserted into each duct. The NOx and 02 concentration meqsurements
for duct number 1 were consistently higher than the corresponding measurements
for duct number 2. These differences we re real and not masked by overall
averages. as verified by oxygen measurements taken indpendently by the boiler
operator. Due to a shortage of gas fuel at the time of testing Boiler F. it
was not possible 'to make additional runs.
Figure 6-5 presents Boiler F NOx emission data in graphical form.
while Table 6-16 summarizes the NOx reductions obtained in the same
format as used for the boilers discussed before. Staged combustion at
42% reduced load resulted in about 80% reduction in NOx compared to full
load. uncontrolled NOx. while low excess air with staged firing resulted
5.0 about 86% NOx reduct ion. Low excess a ir firing a lone reduced t{0x ' ,
emiss~ons by 15 to 25%
-------
--------~-~----.- --- -~~--~- .
700
600
.~ 500
en
rtI
co
>.
...
c
.. 400
N
o
~
('()
....
rtI -300
.E
a.
a.
..
x
o
2: 200
100
o
o
- 89 -
Figure 6-5
NO EMISSIONS FROM BOilER F
x
(600 MW Horizontally Opposed, Gas Fired)
Circled numbers
denote run numbers.
.~
~
~"
()IU
o
~
.~
~
Staged
Firing
Normal
Firing
100
200
800
300 400 500
Gross Boiler load, MW
600
700
-------
- 90 -
TABLE 6-16
BOILER F - GAS FIRED
NOx REDUCTION THROUGH COr-mUSTION CONTROL
I
Load Comb us tion Control
I I ..
% Staged LEA + Staged
MW Reduction None Low Excess Air Firing Fir:i:ng
560 0 560 ppm-O% 478 ppm-15% --- ---
410 27% 335 ppm-40~~ 271 ppm-19% --- ---
43%
325 42% 253 ppm-55% 185ppm-27% 120ppm-53% 77ppm-70%.
61%
-------
- 91 -
'The experimental design ~d the measured average NOx emissions for
Boiler G, firing gas, are shown in Table 6-17. This b0iler was selected for
testing because of its unusual flexibility. The "all-~..all" Hring furnace
provided an opportunity to simUlate different burner' Datterns and their effects
'on NOx emissions under both staged and unstaged firi~.:.:: conditions. T.here were
. several practical limitations that resulted in the actual experimental design
of 14 runs shown in Table 6-17. Only two days were available for testing this
boiler on gas firing, thus limiting the test program to a total of 14 runs.
Full load (220 MH) could be achieved with normal firing (24 burners) and
''min1m\.nn NOx, staged firing" (18 burners). A maximwn load of 190 M\~ could be
achieved with opposed wall firing (16 burners firing) and a maximum load of
. 125 MW could be reached with simulated corner firing (12 burners firing).
Eight small "NO-ports", located above the top row of front and rear burners,
could not be closed. Thus, a limited degree of two-stage combustion ~s in-
herent to the design of this boiler. Within these constraints, the program
was designed to provide the maximum amount of information. NOx emission re-
duction due to reduced load and low excess air were in line with the reductions
experienced in Boilers A through F.. The emission data obtained in testing
Boiler G are swnmarized in Table 6-18.
TABLE 6-17
BOILER G EXPERIMENTAL DESIGN - FIRING GA5*
(Average NOx Ernrnissions, ppm at
3% O~, Dr\' BaDis)
... .
Burner Firing (L,). 220 MW (L2) 190 }1\.] (L 1) 125 MW
Pattern - Burner No. Hi Ai r La Air Hi Ai r La Air Hi Air Lo Air
(51) Normal - All Burners 675 519 313 236
Firing - All Wall (j)
-------
TABLE 6-18
.,-_.~_..~-.._---__._5J.P.1MAR~LQF. PITSSION DATA F,ROM BOILER~ (220 MW., "ALL-WALL", GAS FIRED)
Operating Data
I Run
I::'
!13
! 14
.
~ll
i
: lla
I
~ 7
1
, 8
!
j 5
~
I 5a
;
: 6
1
Gross
Load
(NW)
124
123
123
125
123
121
124
188
190
191
: 2 220,
i 1 220
~ 3 223
~18
(1)
(2)
(3)
Steam Flow
103 1bs/hr
Fuel
Gas Flow
106 Ft3/hr
Excess
Air
Level (1
High
High
High
High
..----
.). at
Burners
Fi ring Ai r
Ga"" On1 v
Burners
on Ai r
On1v (3)
890
860
840
870
860
840
850
1.05
1.05
1.05
.1.05
1.05
1.00
1.04
1.53
1. 53
1.55
1.83
1.84
1.86
1.80
No
24
18
16
12
1,3,5,7,9,11,13
None
1330
1350
1360
1630
1640
1640
1640
o
6
8
12
None
Yes
Yes
9,10,12
3,4,9,10
Yes
High
Low
12
24
18
16
16
16
No
o
o
No.
None
Low
Low
6
8
o
Yes
9,10,12
3,4,9,10
Yes
Low
No
None
3,4,9,10
High
8
6
o
None
Yes
Low
Low
I 18
24
No i 24
Yes I 18
'-...,...---......--
Yes
9,10,12
N,)
Burne:-s:
N.o Fuel
or Alr(3)
None
None
None
None
I
2,4,6,8,10,12
3,4,9,10
High
High
i
o ,None l' None
._J_-~- .__::.:~.,::,-_.~ _~_~~ne
Test program design.
Average of 16 measurement per run.
Refer to burner pair ~~mbers shown in burner configuration diagram.
Rear DivisionWa11
~.. 71~~~~.rh~~ Right
----- - _u_- .,--.- t03)
: (O @J ~: fJ) 0 O! @
I ;' . r.:- ,rr', h'/
I @ ,::).:. ',2,: 'oJ) . \.6~
\- - - - - .
Left End Front
End
None
None
None
None
None
None
-_.
Avg. Flue
Components
ppm,3% 02
Dry Basis 02
NOx CO %
313
150
225
350
350
236
107
284
400
359
270
519
675
286
-
21
19 4.6
19 4.6
19 5.6
19 5.6
24 2.4
86 2.8
35 2.7
28 2.6
--
25
34
14
14
Gasl
(2) I
C02
%
4.9
8.31
i
8.4 i
i
8.21
7.4 I
j
7.4 i
i
9.31
8.81
10.2 i
10.1 !
I
9.3)
10.11
i
10.2/
j
9.2;
,
9.7\
I
-D
N
4.0
2.2
1.7
3.3
3.9
-------
93 - . '
, ,
.>
.'
All forms of staged combustion produced significant NOx emission
reductions, with the combination of Ipw excess air and staged firing cons~st-
ently giving further improvements: At a load of 125 MW, without low excess
air, the highest NOx emissions resulted from simulated corner firing (S'6,
only 12 burners firing and no staging), followed by Sl, normal firing of,24
burners, S3 horizontally opposed staged firing, S2 "minimum .NOx" firing pat-
tern (18 burners firing and burners 6 on air only), and S5, simulated corner
staged firing ( 12 burners firing and 12 burners on air only). These results
are in the expected order. With no staging, 12 burners produced more NOx than
24 burners fired at only one-half the fuel rate. With staged firing, the
simulated corner firing produced lower NOx than horizontally opposed firing.
For full load staged firing, 3 pairs of burners could be opera~ed on air only.
Experience gained in testing this boiler indicates that pairs 9, 10 and 12 on
air only would give minimum NOx emissions.
Carbon monoxide em~ssions measured from Boiler G were less than
100' ppm and hydrocarbon measured less than 1 ppm. No visible haze was al-
lowed to occur during our tests. Consequently, comb~stion was essentially
complete in all runs.
The results obtained in testing Boiler G are presented again in
Table 6-19 and Figure 6-6 to aid in the analysis and interpretation of the
data. Full load, uncontrolled (except for the "built-in" two-stage combustion)
"NOx' emissions of 675 ppm measured'in,this boiler were rather high. The boiler
operator indicated that changing the gas spuds to a newer design had resulted
in 'roughly cioubling the NOx emission levels. Although we had no opportunity
to verify this increase by running .tests with the two different gas burner
designs, this factor points out a potentia~ly fruitful area for em~ssion
control research.
TABLE 6-19
BOILER G - GAS FIRED NOx REDUCTIONS
THROUGH COMBUSTION CONTROL
Combustion Control
Load Sta~ed Firing Staged Fi rin~ + LEA
MW % Reduction None LEA 'Min. N()" I H.-a. - 'Min. NOxt lu f'\
220 675 ppm 23% 58% 60%
0 0%
190 550 ppm( l~ 21% (2) 35% 48%
,14%
125 I 313 ppm 25% 52% 58% 66% 53%
43% .54%
(1)
(2)
Estimated'from trend line calculated from runs 3 and 12.
Reduction due to low excess air in horizontally opposed firing runs at 190 ~~.
. '
-------
700
600
II)
~ 500
D:J
>-
...
cr
..
N /1"'0
o '-tV
~
«)
...
ru
K 300
a.
..
x
o
:2
200
100
o
o
- 94 -
Figure 6-6
NOx EMISSIONS FROM BOILER G
(220 MW "ALL-WALL", GAS FIRED)
Circled numbers
denote run numbers.
Simulated
Corner
Firing, No
Staging
Simulated
Corner
Staged
Firing
Normal
"All Wall"
Firing
.~
~.
~
CJ(U
o
~
.~
~
Horizontally
Opposed Firing
Runs 5, 6 & 14 Stag'
Run 5a Not Staged
4 } "Minimum NOx
2 Staged Firing
I 50
250
100150 200
Gross Boiler Load, MW
300
-------
- 95 ~
6.2.3
Tangential and Vertical
Gas-Fired Boilers
Boiler H in our test program was a medium sized (320 ~v), tangentially
fired boiler. Although this boiler is operated with either gas or oil, only
the latter fuel was fired during our tests. Therefore, a summary of gas fired
emission data and operating variables were requested from the boiler owner
.operator which were kiridly supplied to us. These experimental runs, made over
a period of Lime, led to their "finall acceptable operating modes" for loads
varying between 320 MW and 60 MW as indicated in runs 31 through 36. Operating
variables tested by the boiler operator in addition to load \-lere staging (air
only to a row of burners), flue gas recirculation' (through secondary air dampers),
burner tilt, air damper settings, and excess air level. .
Analysis of the NO emission data presented in Table 6-20 indicates
that flue gas recirculation ~t low excess air levels provides a prattical
and effective means of reducing NO emissions from this boiler operated on
gas fuel. Figure 6-7 presents theXrelationship between percent flue gas
recirculation and NO emissions. The use ~f 18% (at 320 MW load) to 43% (at
60 MW load) fluegasXrecirculation with low excess air (while maintaining
low CO emissions) appears to provide good NO emission control for this
tangeritially fired boiler. The use of stagea firing was reported by the
boiler operator to introduce operating difficulties, and therefore, has not
been used by them for reducing NO emissions. Burner tilt and air damper
'setting are adj ustp.d at each loadXto avoid higher water tube meta 1 tempera-
tures with minimum use of attemperation sprays. Thus, the use of. their
"fl1'nal"'cce~"'~b'e n-~~-...~-- --.I-" ..,cc"""'-'~-"ed - -~.. '-"~~n ~n un' e ~- ~
. t.. -t~,,-a ~ '-l)C:J.ui...~il6 ~h'.JU'=.: ~g \",'lHt-'J...i..:"L1-.." .i..t\.il.,.i;..l..l..,-' ~L ::;V;,x. ffiJ..L>S.i...Cns .
from' 340 ppm to 110 ppm at full load (320 MW) with further reduction between
65 ppm and 85 ppm NOx at lower loads. . .
The emission data obtained in testing Boiler I are summarized in
Table 6-21. This 'boiler was originally designed as a wet bottom vertical
coal fired boiler. It has been converted to gas firing. Boiler I has six
burners in a single row firing downwards from the roof of the furnace. Our
planned series of experiments on this boiler could not be performed com-
pletely. High load demands at the time of 'the test program did not allow
emission tests at reduced loads. Also, after running four tests, the boiler
was suddenly taken "off line" due to fuel gas shortage caused by cold weather
conditions. Thus, some planned experiments with low excess air firing,
staging and adjusting air damper positions to vary air-fuel mixing could
not be performed. Plant experience using Orsat measurements indicated that
air leaks upstream of our probes amounted to between 5% and 8% of the total
flue gas. Thus, our 02 measurements were probably 1.0% to 1.6% higher than
the residual 02 concentrations at actual furnace conditions.
Analysis of the data obtained at full load conditions suggests
that air damper positions at the burner as well as staged firing have an
important influence on NO and CO emissions from this boiler. A high
excess air level (5.3% 02xin the flue gas) .with air dampers 80% to 100%
open resulted in relatively low NOx emissions of 155 ppm and low CO emissions
of about 12 ppm. Lowering excess air to the point where CO emissions
-------
TABLE 6-20
Boiler ppm
Run Load ,'% Flue Gas Burner Primary/Secondary % 02 3% 02, Dry Basis Run
No.- MH -- Stalling R e.'~; ...,." 1 '" ~; '''T'I Tilt Air DamDers Drv Basis NOv CO Conditions
1 320 No 0 Normal Normal 3.3 340 175 (2)
3 320 No 0 +Max. (up) 'Normal 2.7 335 50 (2)
5 320 No 30 Normal Normal 2.2 105 50 (2)
6 320 No 16 Normal Normal 2.7 165 80 (2)
9 320 No 0 Normal 32 'i'.l 00% 2.7 245 100 (2)
10 315 Yes 0 Normal Closed 5.5 375 200 (2)
11 280 Yes 0 Normal Closed 5.6 320 80 '(2)
13 280 No 35 Normal ,Open 2.5 95 50 (2)
14 320 No 27 Normal Open 2.9 90 50 (2) ,
15 320 No 17 Normal Open 2.4 130 60 (2)
16 240 No 0 Normal Normal 5.0 230 2100 (2)
17 240 No 0 Normal Normal 7.5 435 50 (2)
18 240 No 0 +Max. (up) Normal 6.0 390 50 (2)
20 240 No 39 Normal Normal 2.9 95 50 (2)
21 240 No 21 Normal Normal 4.1 135 100 (2)
24 240 Yes 0 Normal Open 6.2 345 50 (2)
25 240, Yes 0 Normal Open 5.7 315 160 (2)
26 ' 240 No 41 Normal Normal 2.7 90 100 (2)
28 320 Yes 21 Normal Open 2.2 105 150 (2)
31 320 No 18 Normal Normal 2.0 no 50 (3)
32 240 No 23 Normal Normal 2.2 80 600 (3)
33 160 No 32 Normal Normal 2.9 65 50 (3)
34 120 No 37 Normal Normal 5.5 65 50 (3)
35 80 No 43 Normal Normal 8.9 " 85 50 (3)
36 60 No 43 Normal Normal 11.0 85 50 (3)
I I
~ ..' .,.~..,-
SUMMARY OF EMISSION DATA FROM BOILER H
, '(320 MW, TANGENTIAL, GAS FIRED(l)
\0
0\
"(1)' Data supplied by boiler owner-operator;
(2) Initial experimental runs.
(3) 'tr'ina 1 acceptable operating mode. II
-------
~
C'<'\
500
II)
II)
C'i:S
co
>-
...
o
, 30
N
a
....
C'i:S
E 200
a.
a.
..
x
a
2
100
Figure 6-7
*
NO EMISSIONS FROM BOilER H
x .
(320 MW, Tangential, Gas Fired>
Circled numbers
denote run numbers.
Regression curve for all data
/
.\0
"
o
o
5
10
35
15
20
25
30
40
45
0;0 Flue Gas Recirculation
*
Emission date supplied by.boiler operator.
-------
TABLE 6-21
SUMMARY OF EMISSION .DATA FROM BOILER I (66MW, VERTICAL, GAS FIRED)
Gross Number Burner (1)
Boiler Load Stearn of . Air Average Flue Gas Components
Run Equivalent Generation Burners Staged Dampers Drv Bas; g 3% 0'> n,." ""'c::;c:: Flue Gas
No. fMtJ) 103 lb Ihr Firing Firing /:. Open 0" % CO" % NO.. CO Temp. of.
1 66 683 6 No 80-100 5.3 9.4 155 12 553
2 66 682 6 No 1,0-45 3.2 9.7 252 405 551
3 66 682 6 No' 20 3.4 9.6 235 143 548
Yes (2150
4. 66 683 6 2.5 10.9 127 528 555
I -.,.... -
(1)' Average of 12 data points.
Each data point measured on a cqmposite of 3 gas streams.
\D
.~
I
(2)
2 end burners fired fuel lean, 4 inner burnersflred fuel. rich.
-------
- 99 -
becam~ high (405 ppm) , but closing the air dampers to only 40-45% open,
increased the NO emission level to 252 ppm. This increase might be ex-
plained by highef flame temperatures caused by better air-fuel mixing.'
In Run 3 the excess air level was increased slightly to reduce CO emissions
to about 140 ppm, and the dampers were closed to a 20% open position. NO
emissions were reduced by less than 10%. In Run 4, the end burners were x
run fuel lean, while the middle 4 burners were run at a fuel,rich condition.
The excess air was reduced to the point that the CO emissions increased to
over 500 ppm. This method of operation resulted in NO emissions of about
x
127 ppm.
Our overall conclusions on combustion modifications for NO
.x
emission control for gas fired boilers are discussed in section, 2 of this
report.
. .
-------
- 100 -:
6.3
Individual Emission Results
on Oil Fired Boilers
Field test programs were run on nine oil fired boilers. Three
front ~all fired (A, B, J), two horizontally opposed (D, E), one 'all-wall "
(G), two tangential (R, K), and a cyclone fired boiler (L) were tested.
Six of these boilers (A, B, D, E, G and R) were also tested while firing
. gas as discussed in section 4.2. Comparison of the emissions data obtained
on these boilers fired with either gas or oil is discussed in section 2
of this report. .
'j
6.3.1
Front Wall Oil-Fired Boilers
Boilers A, Band J are front wall fired boilers, manufac.tured by
Combustion Engineering, Riley Stoker and Babcock and Wilcox, respectively.
Boiler J was selected for testing because of its unusual feature of flue
gas recirculation directly into the windbox. Unfortunate1y..; this boiler
was not equipped for gas firing and thus .the comparison of emissions. as
affected by fuel type could not be made.
Table 6-22 presents the average NO emission results correspond-
ing to the statistical experimental design w!th oil firing of Boiler A.
A'sUTmnsry of the 16 test runs made on Boiler A, fired with "low sulfur"
fuel oils, is given in Table 6-23. Runs 1-14 were made with one grade
of oil, while Runs 15-18 were made with a second grade of oil containing
lower sulfur and nitrogen levels. Figure 4-8 presents the NO. ~missions
.. - x
in graphical form. Loads and relative excess air levels were the same
in gas and oil fired test program designs; however, a third level of
staging was used in oil firing. To achieve full load operation with
staged firing,. specia 1 "b~g" oil guns had to be used so that 12 burners
could fire the same amount of fuel oil as 16 normal guns. Thus, at full.
TABLE 6-22
EXPERIMENTAL DESIGN FOR BOILER A - FIRING OIl
_(Average NOx Emissions, ppm at 3% 02' Dry Basis)*
Ll (180 MW) L2 (120 MW) L3 (80 MW)
Al AZ Al A2 Al A2
Lo Air Hi Air Lo Ai I' Hi Air Lo Air Hi Air
S! (All Burners . 238 CD 367 ~ 241 f.4--; 322 C~ 191 (f 266 (1
EQ ua!) 259 8 181 a1
S2 (Staged 201 H 253 @- 185 (~ 241 ~'
Fi ring) 160 a I 232 \./-v
S ("Big" 011 315 @ 418 @
3
Guns)
* Circled numbers denote run numbers.
-------
TABLE 6-23
SUMMARY OF EMISSION DATA FROM BOILER A (180 MW,'FRONT WALL, OIL FIRED)
Avg. Flue Gas Components(l) (2) Flue
Gross
Bo iler Fuel Staged No. of J ppm. 3% °2. ppm. 3% 02, Gas
~
Run Load Steam Flow Oil Fired Firing Burners '?o, Dr Bas'is D !'; D/o, Drv Rasis Dry Basis Temp.
No. HW 103 1bs.. /hr.(4) 103 1bs. /hr. (3) Firing 0 C02- NO CO HC O' C02- NO of
-2- --x -2- --x-
77 460 38 12 1 12.7 266 14 <1 603
1 No ! 4.6
2 77 470 39 No 12 2.0 14.8 191 20 <1 586
3 122 750 57 No 16 4.6 12.7 322 19 <1 632
I 4. 120 758 56 No 16 1.7 14.9 241 25 <1 642
I 5 182 1220 83 No 16 I 3.9 13.1 367 19 <1 3.5 13.0 348 682
I 6 182 1240 82 No 16 1.7 14.7 238 42 <1 1.3 14.4 217 688
I
I 9 119 750 56 Yes 12 3.5 13.4 185 29 <1 3.1 13.3 169 687
i
/10 119 740 57 Yes 12 I 4.8 12.5 241 18 <1 4.4 12.2 ~07 '688
III 179 1210 82 Yes 12 4.9 12.4 253 21 <1 4.3 12.1 238 . 588
[ ~
I 12 . 179 1220 82 Yes 1-2 3.7 13.5 201 32 <1 3.3 13.0 189 585 0
113 82 12 j 12.9 408 18 <1 632 ......
179 1210 No 1 4.4
i 14 178 1219 82 No 12 I 2.5 14.6 315 32 <1 643 ".
; 15 178 1215 83 Yes 12 3.9 12.8 160 43 <1 684
i 16 120 730 57 Yes 12 5.4 1l.6 232 26 688
/17 119 750 56 No 16 ! L8 14.5 181 31 681
18. ! 179 1210 83 No 16 i 3.1 13.4 252 24 673
,
i
(1) Average of 16 data points per run. Each data
(2) Analyses obtained by boiler operator. NOx by
(3) Burner patterns: 000 0 0 0 0 0
o 0 0 0 0 ° 0 0
o 0 0 0 0 0 0 0
000 0 0 0 0 0
No No
70 MW 120 MW
Staging:
Load:
point from a composite of 3 gas streams.
PDS: 02 and C02 by Orsat analyses.
o 0 0 0 0 0 0 0 Key:
EOOE AOOA
OEEO OAAO
o 0 0 0 0 0 0 0
No Yes
120 MW and
180 MW
o - Firing Fuel
A - Air Only
E - No air or fuel
(4)
Burner Gun Size: Normal Normal No'rmal "Big"
All runs with "low sulfur" fuel oiL Runs 1-14 with one grade of fuel oil, Runs 15-18 with another lower
Sand N content fuel oil.
-------
500
.~ 4-00
<11.
~
CJ
->.
,...
C
.. 300
N
a
~
('t)
..
~ 200
E
a.
a.
..
x
a
:2 100
o
o
C i rc I ed numbers
denote run numbers.
50 -
Figure 6-8
NOx EMISSIONS FROM BOILER A
(180 MW, Front Wall, Oil Fired)
High Excess Air IHJ -12 Big Guns
5 Normal Firing
Low Excess Air [H] -12
High Excess Air 11
6
Low Excess Air
Low Excess Air
100 - 150
Gross Boiler Load, MW
Big Guns
Staged Firing
. Normal Firing
Staged Firi rag
200
~
o
N
250
-------
. - 103 -
loadt 51 denotes firing with 16 oil gusn;52t firing 12 "big" guns.with four
burners on air only; and S3 ~ firing 12 "big" gtffiS.
Analysis of the results obtained indicates that reducing the load
in oil firing does not reduce NO. emissions as much as reducing the load in
gas firing. Low excess air firi~g, howevert did reduce NO emissions ~etween
18% and 35% for all loads and types of firing. Staged fi~!ng reduced NO
emissiono between 25% to 35%. The combination of 'low excess air with st~ged
firing resulted in the largest reduction of about 45% in NO emissions. The
effects of these combustion modifications on NO emissions ~re summarized in
Table 6-24. x
TABLE 6-24
BOILER A - OIL FIRED
NO REDUCTION THROUGH COMBUSTION CONTROL
-x
Load Combustion Control
MW % Reduction None Lo\,;I Excess Air Staging LEA .+ Staging
180 367 ppm 0% 238ppm 35% 253ppm 31%. 201p'pm 45%' I
0% 0%
120 322ppm 0% 241pprn 25% 241ppm 25% 185ppm 43% I
33 i~ ... ...,,... 11~ ' 5% 8% j
J.J:../O
80 266ppm 0% 190ppm 28%
56 % 28% 20%
_-
The use of 12 "big" oil guns at full load and no' staging resulte'd
in an average 20% increase in NOx emissions, compared with staged firing with
16 smaller burners. The use of low sulfur (0.18% vs. 0.45% by weight)t low
nitrogen (0.21% vs. 0.36% by weight) fuel oil reduced NOx an average of 30%
(to 183 ppm from 263 ppm) at comparable operating conditions (Runs 15 through
18 vs. Runs 12, lOt 4 and 5). This corresponds roughly to a 30% conversion to
NOx of the differential in fuel nitrogen between the two fuel oils. Because
of other differences in fuel oil quality, these changes in emission may also
have been due to factors other than fuelN content.
Table 6-25 presents a summary of emission data obtained from Boiler
B firing oil. The primary operating variables included in the experimental
design were load, excess air levelt staged firingt and grade of fuel oil. The
full load rating.of this front wall Riley Stroker boiler is about 80 megawatts.
The lowest load with which the boiler could be operated efficiently while
firing all 12 burners was about 50 megawatts. With 10 burners firingt the
lowest effective load was about 20 megawatts. Excess air was limited to the
-------
TABLE 6-25
SUMMARY OF EMISSION DATA FROM BOILER B
(82 MW, FRONT WA~.L, OIL FIRED)
! -
Flue Gas Components (1) and Temperatures
Total No. of Burner 3% °2 ITemp.
Gross Steam Oil (3) Burners Position Dry Basis Drv Basis
Run Load Flow Flow Excess on -r Air (inches 02 C02 NOx CO (4) Burner
No. HW 103 1b/hr. Bb1/hr. Staging Air Fuel i On1v out) % % (PPM) (PPM) of Patterr
r
1" 2LO 190 160 No Low 10 i 0 10 4.3 12.8 185 45 515 OXOOXO
I 000000
i
i OAOOAO
2 20.5 190 160 Yes High 10 ' 2 10 6.1 11.2 207 38 524
i 000000
3 50.5 440 330 Yes Low 10 2 14 3.9 13.0 252 94 623 OAOOAO
000000
-4 51.5 450 325 No Normal 12 ' 0 1/1 4.5 12.4 361 46 637 000000
000000
5 81.5 750 550 Yes Low 10 i 2 22 3.3 13.3 293 59-130 758 OAOOAO
i
.~ 000000
6 81.8 745 520 No Normal 12 I 0 22 3.9 13.2 560 59 768 000000
000000
"I
7 81.5 750 540 Yes Normal 10 I 2 22 5.0 12.3 373 63 775 OAOO/\O
000000
8 81.5 745 530 No Low 12 0 22 2.4 14.2 453 79-970 750 000000
000000
17 20.0 170 160 " Yes Low 10 2 10 5.3 12.2 203 87 477 OAOOAO
000000
I I
18 21.0 180 162 No Normal 10 I 0 10 5.8 11.8 258 -- 488 i OxOOXO
I
I ! 000000
i ! 000000
19 50.0 425 320 No Low 12 ! 0 14 2.6 14.1 218 104 602
I 000000
21 82.0 750 445 No Normal 12 0 22 3.4 13.6 600 69 760 i 000000
I 000000
22 82.0 750 S~O Yes Low 10 2 22 3.5 13.7 99-580 209 748 OAOOAO
i 000000
I
23 82.0 750 540 No Low 12 0 22 2.0 14.6 70-379 265 I 737 I 000000.
I " 000000 I
24 82.0 750 540 Yes ! Normal 10 2 22 5.1 12.3 434 64 I 76':) ! OAOOM :
I I 000000 :
(1) Hydrocarbon emissions measured <1 ppm.
(2) Burner Code: X No Fuel or Air, A Air Only, 0 Fuel and Air
(3) Runs 1-8 on "low S" 0.31% N fuel oil.
runs 1-17 on "normal S", 0.41% N fuel oil.
(4) Runs 17 and 18 air preheater by-pass used.
I
~
o
.p-
I
-------
----- _.- -~- - .1- -~- .---
. - 105 -
lowest air level at which the boiler could be operated with a clear stack
(slight "e fficiency haze". only) *, and at CO levels generally less than 200-
300 ppm. Staging was accomplished by introducing air only through two burners
of the top row,. as shown in Table 6-25.
Tables 6-26 and 6-27 summarize the effects of changing the boiler
operating variables on NOx emission levels. This information is presented.
graphically in Figure 6-9. Reducing load from 82 HW to 21 HW {Le., by 74%)
reduced NOx emissions by 35%to 60%. Staging (introducing air on1y through
two top row burners) reduced NOx emissions by 20% to 35%. Reducing excess
air when operating at full load consistently reduced NOx emissions by about
20% both under normal and staged firing conditions. Comparison of NOx emis-
sions from low N oil firing (Runs 21 through 24) with NOx emissions for higher
N oil firing (Runs 5 through 8) at full load showed a reduction i~ NOx emis-
sions of about 9%. The combination of staged combustion with low excess air
firing reduced NOx emissions by 46% at the full load of 82 HW, by 30% at 50
NW, and by 21% at 21 1'IW load.
TABLE 6-26
TEST PROGRAM DESIGN FUR BOILER B' - FIRING OIL
(NOx Emissions, ppm at 3% 02, Dry Basis)*
L, (82 MW<) . L? (50 MW) L3 (20 MW)
, Al (Normal) A2 (Lo Air) A1(Norma1) A2 (Lo Air) . A1 (Normal) A2 (Lo Air)
Sl(Norma1'Firing) (6) 560 @. .453 @) 361 @ ..318 ~. 258 CD 185
~
~ 600 ~ 486
S2(Staged Firing) (j) 373 8 293 @ 290 ~ 252 @ 207 @ 2Q3
@) 434 335
-
*
Circle'd numbers are test run numbers.
Runs 1 through 8 fuel oil composition: 0.31% N, 0.26% S, andO.03 ash
Runs 17 through 24 fuel oil composition: 0.41% N, 0.32% S, andO.lO ash
*
"Efficiency haze" is a term used by the boiler operator to describe a
slightly opaque stack condition resulting from lowering the excess air
level for increasing boiler efficiency.
-------
600
500
400
VI
VI .
ra
co
>-
. ...
Q
,
N
o
~ 300
('()
..:.
ra
E
a.
a.
,
x
o
z
200
100
o
o
- 106 -
Figure 6-9
NO EMISSIONS FROM BOilER B
x .
(82 MW, Front Wall, Oil Fired)
Circled numbers
. denote run numbers.
.~ r
~
~"
(.JflJ
o
~
~
.;:?
20
60
Gross Boiler load, MW
80
40
Normal Firing
Staged Firing
100
120
-------
107 -
TABLE'6-27
BOILER B - OIL FIRED'
NOx REDUCTION THROUGH COMBUSTION CONTROL
Load Combustion Control -
N\'l % Reduction None Los Excess A'ir Staged Firing' LEA + Staging
.-
82 580 ppm 0% 470ppm 19% 404ppm 30% 3l4ppm 46%
0%
50 36lppm 3l8ppm 12% 290ppm 20% 252ppm 30%
39% 38% 32% 28% 20%
21 258ppm l85ppm 28% 207ppm 20% 203ppm 21%
74% 54% 61% 49% 35%
Table 6-28 presents the summary' of the emission data obtained from
Boiler J. This medium-sized (250 MW), twin-furnace, front wall 'boiler had
duct work for flue gas recirculation into the windbox of each furna~e. Boiler
. boiler. In. addition, sampling pump failures and boiler control problems
have more uncertainty than those obtained later on. Our sampiing and analytical
system had been substa..itially improvt:d after the "break-inl! experience on this'
bpiler. In addition, sampling pUwp failures and boiler control problems
resulted ir:t an incomplete implementation of the statistical experi,men tal design.
In spite of the above limitations, analysis of the data led
to the following conclusions. Thp combination of full capacity flue gas
recirculation with low excess air and staged firing reduced NOx emissions
by more than 50% at full load (from about 340 ppm to less than 150 ppm) and
about 50% at two-thirds load (from about 300 ppm to 155 ppm). Staged firing
(top row fired lean, and middle and bottom rows fired rich) without flue gas
recirculation reduced NOx emissions by about 20%.
Regression analysis indicated that about 75% of the variation in
NOx emissions could be explained by, or were related Co combustion controls.
With NOx expressed in parts per million corrected to 3% 02, dry basis, the
regression equation was:
2
ppm NOx = 238 - 25.4 Xl + 0.31 X2X3 - 17.6 X2X4
. whe re :
Xl = extent of flue gas recir~ulation (0 for none, I for partial, '
2 fur full capacity),
X2 = excess air level (% 02,in flue' gas),
X3 = load (MW),
X4 = staging (0 for normal firing and I for staged firing).
A slightly better fit was obtained by correlat;ing t~e logarithm of the NOx
emissions measured as ppm with the above variables.
-------
108 - .
Log (ppm NOx) = 2.36 - 0.0559 X/ + 0.0049 X2X3 - 0.0279 X2X4
The correlation coefficients and standard errors of estimate for the linear
and the logarithmic regressions were r = 0.86 and 0.90, and s = 32 ppm
and U.054 log units, respectively. y
Run
No.
1
2.
3
4
5
6
7 ,
8
9
10
11
12
13
14
15
16
17
18
(1 )
(2)
(3)
(4)
(5)
Gross
Boiler
Load
(HW) (1 )
79
84
86
84
86
86
81~
86
116
118
124
127
122
127
84
83
84
83
TABLE 6-:-28
SU~lliARY OF EMISSION DATA FROM BOILER J
(250 HW, Front Hall , Twin Furnace, Oil Fired)
Staged
Firing
(2 )
Excess
Air
Level
(3)
Extent of
Flue Gas
Capacity
Used
.Partia1
Partial
Partial
None
None
None
Flue Gas Components(4)
and Tern eratures
Dry Basis ppm, at 3% j
% 02,DryBasis of
CO~ CO NOx Tern.
o
1.0
1.0
1.6
2.6
1.0
0.9
14.4
15.1
13.8
13.8
15.0
14.4
!'Jo~e
') ') 1""
; L..":" ; ":"'-'. /
None
None
Full
None
Partial
None
None
None
None
Full
Full
2.3
2.5
1.4
2.9
1.9
2.0
2.0
3.1
2..9
1.0
1.2
13.5
13.9
14.3
13.2
13.7
13.8
13.7
12.7
12.8
14.9
14.7
20
(5 )
270
41
10
8
(5 )
53
239
218
198
353
298
229 .
274 .
267
305
142
350
265
270
.370
260
246
153
174
532
510
550
514
520 '
515
695
590
582
545
545
545
550
Per furnace, including 7 MW equivalent for each 100,000 lb. of steam
supplied to customer.
Staged firing: yes - top row of burners fired fuel lean (about 20%
of total fuel), bottom 2 rows fuel rich (about 40% each).
Test program design.
Yes.
No
No
No
No
Yes
Low
Low
Low
High
Low
Low
Average flue gas composition from No.2 furnace only (average of 6 to
8 flue :gas samples).
>1000 ppm on probe with lowest 02 measurements.
Yes.
HiS~
Yes
No
Yes
. No
Yes
Yes
No
No
Yes
Yes
No
High
High
Low
High
Low
High
High
High
High
Low
Low
-------
Run
. No.
6.3.2
~ 109 -
Horizonta1~y Opposed Oil .Fired Boilers
Table 6-29 presents the summary of emission data obt~ined in test- .
ing with oil fi-.:-ing boiler D, a 350 HW, horizontally opposed single furnace
~.::ibcocl, and Wilcox boiler equipped with "NO-ports" for two-stage combustion.
Gross
BoiJ er
LoaJ
MW
6
5
'I
...
349
348
351
352
350
351
151
15[1
Ii;;'
I 154
I 154
3
1
4
7
8
9.
10
11
12
Total
Steam
FlOl.]
06 1b/hr
I ,
I
I
I
215
215
215
215
216
216
96
100
99
98
98
.98
TABLE 6-29
SUHHARY OF ENISSION DATA FROH BOILER D
(350 ~~, Horizontally Opposed, Oil Fired)
9perating Data
Fuel
Oil Flow
Bb1s/hr
-
485
487
484
486
484
484
237
245
. '240
245
244
242
Excess
Air
Level
Low
Lo'..,
Low
High
Lm-I
High
Low
LO\.]
. Lm.]
Low
High
High
-
"NO-
Ports"
Burner
Staging
(2)
Open No
Shut No
Open Yes
Open Y~s
Shut Yes
Shut. Yes
. Op~n No
Sh ut No
- Shut y~s
Open Yes
~~~~_\ ~::
IFlue Gas Co~?onents (1)T !
I . . and emperature,
Dry Basis I 3% 02
02 C02 NOx CO
% % (ppm) (~pm)
1.8 14.8 308 66
1.4 14.8 442 53
2 . 2 ! 13 . 0 I 284 61
3.4112.4 297 65
1.8~13.5 292 92
3.0 ~1}.6 302 85
2.1(14.6 173 59
1.7:14.9 228 60
2:2 1.l!.4. 152 , 52.!
2.6.14.21118 ! 59
3 . 6 ; 13. 5 1 139 " 55
. '
3.2,13.8 i 17~J..L.45
Temp.
of
711
69'1
69/
703
692
699
617
609
615
615
619
620
J
3 burne r
only).
o 0 0 0 0 0 A 0
(f\ A (f\ (f\ A A 0 A
o a 0 0 0 0 a 0
Front Face Rear Face
Code: a Fuel and air.
A Air only.
Average of 16 data points per run.
of 3 gas sample streams.
"Off-stoichiometric" combustion, middle burner of each
cellon air only (except cell No.7, top burner on air
(1)
(2)
Each data point based on composite
BURNER CONFIGURATION
-------
- 110 - .
. ~e expe:i~ental design and' the average NOx emissions measured in
tes~1ng B07ler D f1r1ng fuel oil are summarized in Table 6-30. The operating
v~r~ables 1~cluded ~n the experimental program were load, excess air, staged
hnng and NO-port setting. The staged firing was performed with the mid-
dIe bUD1er of each 3 burner cellon air only, except for cell number 7 which
had the toP. burner ~n air only (as shown in Table 6-29) due to a mechanical
problem. ~1th the limited time available for field testing, staged firing
was emphas1zed over normal firing.
TABLE 6-30
TEST PROGRAM DESIGN FOR BOILER D - FIRING OIL
. .
(NOx Emissions, ppm at 3% 02, Dry Basis)*
(81) Normal
Firing-
"NO-Ports"
(AI) Hi Air
(A2) Lo Air
(AI) Hi Air
(A2) Lo Air
173
(S'2) Staged
Firing
139
118
*
Circled numbers denote nm numbers.
In order to provid~ an indirect comparison of NOx emissions
reduced by combustion control. for boiler D firing gas or oil, estimates
were made of uncontrolled emissions at full and partial loads as shown in
the footnotes of Table 6-31. Thus, the high excess air, normal firing,
closed "NO-port" results were estimated assuming that the reduction in NOx
emissions due to the application of low excess. air supply was the same for
normal as for staged firing. Although these estimates are subject to con-
siderable error, they provide bases for comparisons without affecting all
of the other direct re12tionships as shown in Figure 6-10 for oil firing.
Low excess air firing with staged combustion reduced NOx emissions by less
than 5% at full load and about 15% at reduced load, compared with the same
mode of operation but using high excess air. The use of open "NO-ports"
combined wit'h low excess air and normal firing reduced NOx by 30% at full
load, and 24% at reduced load. "Full combustion control" (low excess air,
with staged combustion and open "NO-ports") reduced NOx emissions an estimated
38% at full load, and 55% at reduced load. As in .other boilers burning
either gas or oil, the fractional reductions in NOx emissions for'~u11 con-
tro1"are les~ for oil than for gas firing. However, since uncontrolled gas
fired NOx emissions are higher for gas then oil, "fully controlled" NOx
emissions for the two fuels are similar to each other.
'. .
-------
- 111 -
TABLE 6-31
BOILER D - OIL FIRED
NOx EMISSION REDUCTION THROUGH CO~ffiUSTION CONTROL
Estimated:
302
442 x 292 = 457ppm
177
228 x 153 = 264ppm
\
I
I
!
l
i
\
[
\
I
I
I
I
I
Load Combustion Control
"/0 Low "NO"
NW Reduction None Rxcess Air Ports Staging "Full"
350 57 (I);pm 442ppm 3% 308ppm 33% 297wm35% 284wm38%
0% 0%
154 264 ppm(~ 228ppm 14% 173ppm 34% 139ppm 47'i 118ppm 55%
56'10 42% 48% 44% 53%. 58%
(1)
(2)
Estimated:
A multiple regression analysis of the data indicated. that 92%
(r 1:8 0.96) of the variation in NOx emissions from Boiler D firing oil was
r~lated to, or explained by the ,combustion controls as shown in the fol10wi~g
regression equation:
111 + 1.~4 Xl - 45.9 X2 - 0.258 (XIX3)
Xl = gross load (MW)
}C2 = "NO-Ports" (1 for closed, 2 for open position)
X3 = Staged Firing (1 no staging, 2 staging)
The estimated standard error of estimate calculated from this
regression model with 8 degrees of freedom was 29 ppm NOx' Since this
'standard error is considerably higher than our estimated standard deviation
for experimental error, it is apparent that such a regression model is over-
simplified. Extensive field testing on an oil fired boiler is needed to
provide the data for a more realistic, but more necessarily complex empirical
model.
ppm NO =
x
Whe re :
Table 6-32 presents the experimental design and a summary of the
emission data from Boiler E, firing oil. This large (480 MW), opposed wall
fired boiler is equipped with "NO-ports" above the top row of burners. The
statistically designed field test program on this boiler could not be completed
because boiler control equipment failed to operate properly. However, as
shown in Table 6-32, nine runs were made and some important information on
NOx emission control could be obtained.
-------
500
400
If)
If) 300
I\S
QJ
>,
:0...
0
N
0
~
C'<'I
......
I\S
E 200
0.
0.
..
X
0
Z
100
o
o
100 .
- 112 -
Figure 6-10
NO EMISSIONS FROM BOILER 0
x
(350 MW, Horizontally Opposed, Oil Fired)
"NO-Ports" Closed, Normal
Firing, La Air
IINO-Portsll Open, Normal
Firing, La Air
IINO-Portsll Closed, Staged
Fir i ng, Hi Air
II NO -Ports II 0 pen, Stag ed
Firing, Hi Air
"NO -Ports II Closed, Staged
Firing, La Air.
.. IINO-Ports II Open, Staged
Firing, . La Air
Circled numbers
denote run. numbers.
200
300 400 500
. .
Gross Boiler Load, MW
-------
113-
TABLE 6-32
TEST PROGRAM DESIGN FOR BOILER E - FIRING OIL*
(NOx Emissions, ppm at 3% 02, Dry Basis)
- ~1)(455 HH) (L2) (L.) (228 HH)
"NO-Ports" 364 HH)
Excess Air ~) Hi (A2) Lo (AI) Hi (A2~ _lA 1)-BJ (A?~
(P ) "NO-Ports" (Sl) Normal ~ i46 Q) -223 \.9j 219 '@ 183 r-~ -163
. 1 Closed ' Firin~
(S2') Staged ~ @ (;-
-- -- r:v --
Firing
(P ) "NO-Ports" (51) Normal '1\ 200 0 0 164 @ 163 (5) 155
0 --
2
Open Firing
(S2) Staged () -- 0 -- @ --
Firing
* Circled numbers denote run numbers.
Operating conditions and emission test data for Boiler E are given
in Table 6-33. The degree of NOx emission reduction obtained is summarized
in Table 6-34, a-s a function of the combustion controls applied. These re-
~ults are presented graphically in Fignr.e 0-11. Unrontro] led, full load NOx
emissions of 246 ppm were relatively low from this boiler when fired with
low sulfur fuel oil. However, NOx emissions did not decrease in proportion
to load reductions. Low excess air, and the use of "NO-ports", each reduced
NOx emissions but the combination of these controls showed no significant
improvement over the use of "NO-ports" alone. Additional field tests are
required to optimize combustion conLro~s on this type of boiler.
-------
TABL1~ 6-33
,
I
SUMMARY OF EMISSION DATA FROM BOILER E
(480 MW, HORIZONTALLY OFfOSED, OIL FIRED)
,
Operating Data
~ Gros s . Flue Gas Components (1) (2) Flue
; Boiler Fue 1 Oil Main Steam Excess No. of Dry Basis 3% 07, Dry Basis Gas
Run ~ Load Flow Flow "NO- air Burners O. CU2 Temp.
I (MW) 103 Ibs./h::-. 103 1bs./hr. Ports" Level (3) %2 NOx ppm CO, of
No. : Firing % ppm
! -
4 i 227 115 145 Closed Low 16 3.5 13.1 163 12 525
i
i 124
5 ' 229 150 Open High 16 5.0 11. 3 155 14 523
j
9 I 364 175 228 Closed High 16 5.3 12.4 219 19 59"4
i
.
2 I 454 216 285 Closed 16 4.7 13.1 246 15 636
! High
I
3 ! 454 215 290 Closed Low 16 3.6 13.9 22 i 20 625
i
1
1 I 459 220 290 .Open High 16 4.6 13.1 200 21 63.4
I . .
11 358 175 236 Open High 16 4.6 13.1 164 21 649 !
!
10 368. 173 233 Open Low 16 4.0 13.5 163 21 621
8 3E?8 175 230 Closed Low 16 3.6 13.9 '83 19 622
I--
I--
~
~1)
(2)
(3)
Average of 16 data points per run.
Hydrocarbons measured <~ ppm.
Tes~ program design.
Each data point from a composite of 3 gas 9treams.
-------
3QO
VI
VI
CI:S
.aJ
>-
... .
o. 200
..
N
a
~
('('I
.....
CI:S
E
0-
0-
..
x
a
z
100
o
o
. . - 115
'7
Figure 6-11
NO EMISSIONS FROM BOILER E
x
(480 Megawatts, Horizontally Opposed, Oi I
Circled numbers
denote run numbers.
Fired)
{II NO -Ports II
~ Closed
)
\ II NO -Ports II
Open
100
500
600
200 300 400
Gross Boi ler Load, MW
. .
-------
- 116 -
TABLE 6-34
BOILER E OIL FIRED'
NOx REDUCTION THROUGH COHBUSTION CONTROL
Loaa
% Combustion Controls
MI-J Reduction None ',' tEA "NO-Port's" "Fu 11"
455 246 ppm 223 ppm-9% 200 ppm-19% --
0%
"
365 219 ppm 183 ppm-16% 164 ppm- 2 5'70 163 ppm
20% 11% 18'70 18% 26%
228 163 ppm 155 pprn
50% !7% 22%
Table 6-35 presents the emission data and corresponding operating
conditions for the field tests run on boiler G when firing oil. This boiler
(described earlier in Section 6.2 in connection with tests on gas firing) is
an "-all-wall" fired, 220 HW Babcock and Wilcox boiler. It has a single
furnace with a division wall. The burner con,figuration is 'shown in Table
6-35. The major objective in testing this boiler with oil ,firing was to
utilize the flexibility of its burner configuration in the same manner as in
the gas fired test program. Because of the high tube failure experienced at
the division walls, ~ severe limitation on conducting these tests was the
upper limit of water tube, metal temperatures. In addition, the unavailability
cr special high capacity oil guns me'ant that each gun taken out of service
reduced load correspondingly. Thus, the experimental plan was designed to pro-
vide base level emissions at full load, and various firing patterns at the
highest loads attainable. Since the boiler had not been run previously with
most of planned burner patterns, alternate rUf,S were planned in ,case operating
limits forced cancellation of original plans. Normally this boiler fires all
of its burners regardless of load. Te.!:l.;; 6-36 shm'lS the IT!~trix of the planned
runs (1 through 14) as well as the test actually made on NOx emis'3:,ons. The
NOx emission data are presented in graphical form in Figure 6-12.
In line with the behavior of some of the other boilers tested for
NOx control, this boiler proved to be less f1.exible with oil than with gas
firing. The high water tube metal temperatures developed when Run 8 was
attempted forced the cancellation. of Runs 8, 9, 10, 11, 13 and 14. Runs, 15 .
and 16 were made to verify an unexpected increase in NOx emissions with de~
creasing load experienced in Runs 1, 2, 7 and 12. The conditions for Run 19
(6 burners on air) were approached gradually through Runs 17 (3 burners on
air) and 18 (4 burners on air) to prevent conditions leading to high water
tube metal temueratures. Run 20 was then made by gradually lowering the load
and using the ~taged firing pattern of Run 19 until water tube metal tempera-
tures be~an to increase at a load of 150 MW.
Analysis of the tweive nms provided the following conclusions.
Low excess air reduced NOx.~rnissiQOs by 10 ~o 20%. Staged firing reduced
NOx emissions by about 35% at normal excess air 1,evels under both opposP.J wall'
(burner pairs 3, 4, 9, 10 on aL,- only) and "minimum NOx" (burner pair
12 on air onlv). Smaller redurti0'lS were C't!:ained when only one or two
pairs of burn~rs were operated op air only. '
J'
-------
TABLE 6-35
SUMMARY OF EMISSION DATA FROM BOILER G
(220 MW, It ALL-WALL It, OIL FIRED)
, , 1 I
Operating Data Flue Gas Compo s it ion ~l}
- 'CO
HC
Gross Number' of Burners ppm ppm
Boiler Fuel Excess Burners on NOx, ppm Dry Basis 3% 0., 3% 02
Run Load Stearn Flow Oil Flow Air Staging (3) Firing Air Air Only 3% 02 0 C02 Dr/ Dry
No. {MW) 103 1bs/hr 103 1bs/hI Level (5' Oil Onlv (2) Dry Basis "/02 % Basis Basis
1 219 1620 100 Normal No 24 0 0 235 2.6 13.2 19 ~
2 220 1620 101 High No 24 0 0 291 3.9 11.9 19 <1
5 189 1360 90 Normal Yes (4) 16 8 3,4,9,10 pahf 236 5.0 11.3 13 ,<1
3 189 1350 88 Normal Yes 18 6 9,10,12 p airs 170 4.8 11.6 '17 <1
7 122 840 58 Normal No .24 {) 0 293 5.3 11.4 20 <1 '
12 123 840 59 High No 24 0 0 319 6.6 10.3 22 <1
15 154 ,1050 72 Normal No 24 0 ' 0 308 5.7 11.4 12 <1
16'. 195 1380 88 Normal No 24 0 O' 267 4.5 12.5 14 <1
17 195 1380 88 ~orma1 Yes 22 2 9 pair 234 4.5 12.5 14 <1
18' 195 1380 89 Normal Yes 20 4 9,10 pairs 199 4.5 12.4 16 <1
19 199 1400 91 Normal Yes 18 6 9,10,12 pairs 183 4.4 12.5 15 <1
20 160 1000 72 Normal Yes 18 6 9,10,12 pairs 172 5.7 11.3 16 <1
,-- ' ., ....., '_"00_- ._,_.
,....
,....
.......
(1)
(2)
(3)
Average of 8-16 measurements per run.
Diagram of burner pair numbers.
See burner configuration diagram.
Each data point from a composite of three gas streams.
Left End
Rear Wall
,Division Wall,
Right End
(4)
(5)
Simulation of horizontally
Test program design.
-------
- 118 -
.'
TABLE 6- 36
TEST PROGRAM DESIGN FOR BOILER G - FIRING 01L*
(NO x Emissions, ppm at 3% 02' Dry Basis)
(L1)220 MW (LZ),190 MW (L~) 150 N1.f (L/ 120 MH 1
Firing (A1?Hi ~A2) ~or- (A1?Hi(A2)Nor- (A 1) Hi (A2) Nor-(A1)Hi (AZ )"No r~
Patterns A~r malA~r A~r mal Air Air mal Air Air mal Air!
(Sl)NormCll 0291 1 235 @ 267 e 308 @ 324 .cv 293
All Burners
(52) "Hinimum NOx" tID () 170 @In {) @
9,10,12 on Air ~ 183
(53) H.O. ~ G 193 G @
3,4,9,10, on Air
(S4)Tang. {D ~.
A1g. on Air
(SS)Special 0243 @
. 9 on Ai r
(S6)Special @ 199 0
9,10 on Air
-------
300
II)
'II)
!1:S
CQ.
>.
...
o 200.
...
N
o
~
('f)
......
!1:S
E
a.
a.
...
x
o
z
100
o
o
- 119 -
. Figure 6-12
NO 'EMISSIONS FROM BOILER G
x
(220 MW, "AII Wallll, Oil Fired)
Circled numbers
denote run numbers.
Burner pair 9 .
on Air Only
Staged' Firing
. 1fQ\. \
Burner pairs ~ I
9, 10 on Air Onl~ --69)
~
Normal Firing-
All Burners
Burner pairs 9, 10,
12 on Air Only
50
100
150
Gross Boiler. ,Load
200
250
300
-------
- 120
6.3.3
Tangential Oil Fired Boilers
Table 6-37 presents the summary of emission data obtained from
boiler H firing oil. The operating variables included in the experimental
design on this tangential boiler were 'staged firing, excess air, burner tilt,
flue gas recirculation, and air damper settings. All 25 test runs were made
at a load of about 220 MYl, the highest load attainable with staged firing.
Based on information supplied by the boiler operator, uncontrolled NOx
emissions at full load (320 HW) from th is boiler were about 215 ppm.
Staged firing was accorilplished by introducing air only through the
bottom row of burners on each furnace. (This furnace is designed "upside-
down", i.e., the combustion gases travel down through the furnace and super-
heat sections of the boiler.) Excess air levels were establishe'd at' normal
(3-4% 02) and high (5-6% 02 levels). The boiler operator would not allow
firing with low excess air because of the possibility of emitting visible plumes.
(Normally, the appearance of the stack is clear except for the appearance
of water vapor during cold weather.) Th'~ burners were fired at the ext reme
ranges of tilt, i.e., 300 down from horizontal (normal) to 100 up from
horizontal. Flue gas recirculation was established at the maximum and
minimum .settings attainable based On reaching the necessary steam temperature
levels. Primary and secondary air damper settings were adjusted as shown in
Table 6-37, i.e., maximum primary and minimum secondary, or minimum primary
and maximum secondary.
Table 6-38 Ibts ~~Oh .:::D:'SSl.Ons according to the statistical experi-
mental. design. A single replicated factorial design was run at the normal
excess air level,while a one-half replicated factorial design was run at the
high excess air level. Several two and three-factor interactions were found
to be statistically signifi~ant, tending to mask the main effects.
Therefore, Table 6-39 was calculated to indicate more clearly the effects
of varying flue gas recirculation, staging,and excess air levels by averag-
ing the results over all burner tilt and air damper settings. Table 6-39
indicates the grand weighted average values of all main' effects listed in
order of importance.
-------
TABl.E 6-37
SUMMARY OF EMISSION DATA FROM BOILER H
(320 MW, Tangential, Oil Fired)
Burner ~ Flula -' ComDonents (1)
Cross Ai r Dampe rs, Tilt FroJ Gas Fuel Oil - Main % °2 in Fl ue Gas Flue Gas
Bo! 1er- % (}Pen Excess Degree~ Red.r- Flow Steam Flue Drv Basis 3%0 ,~Basis Temper-
Run Load Staged Pri- Secon- Air Horzon- cula- 003 Flow \ Gas 02 C02 NOv CO ature
~o. (MW) Flring(2). marv clary Level (3) tallv, tioiJ. 1bs/hr) J:>o 1b/hr E W % % (ppm) (ppm) of
_.
. -
1 221 No 100 39 Normal -30 MS:1: 1006 1. 34 '3.6 3.3 3.9 12.8 141 .9 714
! 2 216 No 100 52 Normal +10 Min 962 1. 32 13.7 3.2 3.6 12.9 161 13 665
3 217 No 50 39 High +10 Min 976 1. 32 \5.9 6.2 6.3' 10.4 203 16 685
4 221 No 50 39 High -30 Nax 1029 1. 32 5.7 6.2 6.2 10.3 217 18 706
I 5 217 Yes 50 95 High -30 Min 1010 1. 33 6.7 6.6 6.3 10.1 .204 17 695
, 6 216 Yes 50 100 High +10 Max 1016 1. 33 6.6 7.0 6.4 10.1 177 18 706
I '7 215 Yes 100 20 Normal +10 Max 994 1. 33 3.2 3.4 3.3 12.7' 131 13 694
I S 219 . Yes 100 30 Normal -30. }!in 1024 1. 33 4.7 3.6 4.1 13.4 139 13 679 I
I 9 218 No 95 0 Normal +10 . Max 958 1.31 3.7 3.7 3.9 12.8 148 11 703
I 10 219 No 100 0 High -30 Min . 998 1. 33 6.0 6.0 5.0 10.8 235 12 679
i 11 214 No 40 70 High -30 Min 976 1. 33 6.6 5.3 6.3 10.7 174 14 671
i !2 217 No 40 100 Normal +10 Hax 982 . 1.32 3.7 3.8 3.9 12.4 194 14 703
-l} 208 Yes 50 75 Normal +10. Mit! 986 . 1.32 5.1 5.3 5.4 11.2 139 14 667
14 21-7 Yes 50 80 Normal -30 Max 1024 1..31 4.0 4.5 4.5, 11.7' 144 14 703
.High : 10.3 170 15 671
15 214 Yes 100 30 -30 Max 1000 1. 32 6.1 6.2 6.1
16 207 Yes 100 30 High +10 Min 980 1. 33 6.2 6.1 6.5 9.8 185 15 659
17 219 No 100 20 'High +10 Max 1014 1. 33 5.7 5.7 5 ;5/ 10.9 184 15 530
18 209 No 50 60 Normal +10 Min 972 1. 34 4.8 4.2 4.9 11. 7 14'3 14 639
19 213 No 50 60 Normal -30 Min 992 1. 33 5.3 4.8 5.3 11. 3 171 22 653
20 223 No 50 90 Normal -30 Max 1022 1. 34 3.9 4.1 4.3 11.8 150 24 712
Z1 219 No - 100 20 Normal -30 Min 992 1. 33 5.3 4.6 5.3 11.1 244 21 657
22 217 Yes 100 20 Normal -30 Max 1018 1. 32 4.0 3.9 4.0: 12.6 110 23 675
23 211 Yes 50 100 Normal -30 Min 1004 1. 31 5.2 5.5 5.6 11. 2 136 27 653
24 212 Yes 50 100 Normal +10 Max 996 1. 31 4.0 4.3 4.1 12.4 97 28 676
25 201 Yes 100 I) Normal +10 Min 972 1. 31 4.5 5.3 5..3 11.4 150 27 622
-
(1)
(2)
Average of 16 data points per run. Each data point from a composite
of 3 gas streams.
Staging: no-all 24 burners firing equally; yes-16 burners firing,
bottom level on air only.
Test program design.
(3)
~
N
....
-------
i n
I
- 122 -
TABLE 6-38
TEST PROGRA}l DESIGN FOR BOILER H-FIRING OIL
(NOx Emissions, ppm at 3% 02' Dry Basis)
-,H :
(R~)Nax. Flue Gas Recycle (R') )Hin. Flue Gas Recvcle '
( I)Norma 1 (SZ)Staged '- 1 (SZ)Staged
Air Dampers (S1) Norma 1
Firing Firing Firing Firing
(D l) (1) (DZ) (D1) I (DZ) (D1) i (DZ) I (D1) i (DZ) ,
-- ~..
! ! ' ! I I
(AI) Norma 1 (Tl) (2) 141 I 150 llO I 244 1171 1139
I I 144 136 I
Excess i ; f j I
Air (T2) . 148 i 194 I 131 97 161 ' 1156 i I
i 143 139
:: ! ! I i I I I
i I
I i i : I ! '
I I ' j 174 (3») I
(A2 )High (Tl) I 217 141 I 235 j 204 I
I I i ! i
Excess , i
Air (T2) I 184 ! ~ ; 177 203 i 184 i
I ' ! ; .1
J i )
I j !
( 1)
(Dl). -
(DZ) -
Primary air dampers at
minimum settings.
Primary air dampers at
maximum settings.
maximum open, secondary air dampers at
minimum open, secondary air dampers at
(2)
(Tl) - Burners tilted down.
(T2) -'Burners tilted up.
(3)
Extra run not used in ca1cu~ating grand averages in Table 6-39.
TABLE 6-39
BOILER H~FIRING OIL GRAND AVERAGE NOx EMISSIONS*
PPM AT 3% 02, DRY BASIS
(Rl)Maximum Flue (R2)Minimum Flue
Gas Recirculation Gas Recirculation Grand
SI S2 51 verage
Al (Normal Air) 158 120 180 142 150
A2 (Hi Exc. Air) 200 159 219 194 193
Grand Averages 179 140 200 168 172
* NO emissions averaged over all burner tilt and air damper settings tested.
. x
-------
- 123 -
'. As shown in Table 6-39, the overall grand average of NOx emissions
was 172 ppm. The base-line emi-ssion level (minimum flue gas recirculation,
norma.l firing, and normal excess air) was 180 ppm NOx' Increasing excess
air with normal firing and minimum flue gas recirculation increased NOx
emissions by about 22% to 219 ppm. The lowest average NOx emissions
(120 ppm) resulted from combining maximum flue gas recirculation and
staging with normal excess air firing. Additional improvements were
made by tilting the burners up with minimum opening of the primary
dampers (97 ppm NOx) , or by normal burner tilt and maximum primary air
settings.
Figure 6-13 presents graphically the average NO emissions
listed in Table 6-39. The separate effects of changing t~e three
most important operating variables (excess air, firing mode and recir-
cul~tion levels) are readily seen in this figure.
Table 6-40 presents a summary of emission and operating data
obtained in testing boiler K, a small, oil fired tangential boiler.
This boiler had been selected for our Boiler Test Program because
gas as well as different grades of fuel oil were expected to be
fired, supplied from barges adjacent to the plant. However, the oil lines
and docking facilities were removed a few weeks prior to our actuai test
program. Consequently, only a limited number of test runs could be made
.on this boiler. . . -
Boiler K and another boiler provide stearn to a single turbine
generator. The second boiler was d~wn for repair work, consequently,
boiler K could not he run it less t~a~ 600,obo lb. of steam per hour
due to minimum turbin~ ~team requirements. Although a more detailed
- test program was planned, gas was not available due~o cold weather
conditions, and only one grade of oil could be fired. No fuel adjustments
could be made On the lower level of ~,..rners because of the absence of
pressure gauges. Therefore, "si"1ulated" staging using the lower level
burners could not be performed:
Run 1 was made under normal "full load" (620,000 lbs. of
steam per hour) conditions with all burners firing equally. Runs 2 and 3
were made to simulate staged combustion at the lowest excess air level
available as dictated by plant smoke measurements. No reductions in NOx
emissions were found resulting from these highly limited attempts at
staged firing.
-------
300
250
VI
:G 200
co
>.
:>...
.0
..
N
o
"~ 150
.C<)
--'
ro
E
0-
a..
..
OX 100
2
50
o
- 124 -
Figure 6-13
NO EMISSIONS FROM BOilER H
x
(320 MW, Tangential, Oil Fired)
Boi ler operated at
220 MW load. Each
data point based on
average of 2 to 4 runs.
"~Jormal"
"High II
Excess Air Level
. .
}. .Normal .
Firing
Staged
Firing
-------
TABLE 6-40
SUMMARY OF EMISSION DATA FROM BO~LER K (66 MW.. TANGENTIAL. OIL FIRED)
.>
- Componen ts (1)
Gross Number Flue. Gas
Boiler .Steam of NOv (ppm) CO (ppm)
Run Load(4) Flow Burners ' "Staged" Dry Basis 3% 02 3% 02 , Flue Gas
~
No. NW 103 Ib/hr Firing Firing O.~ '70 CO? % Dry Basis Dry Basis Temp. °F
I 1 \ 66 620 8 No 2.4 14.9 146 27 I 674
I Yes(2)
2 66 608 8 4.0 13.4 203 I 28 I 673
I . I !
' I
I I
i I Yes (3) !
3 66 600 8 2.8 14.0 146 37 685
I I I
! i ! I I
(1)
Av~rage of two data points.
Each data point from composite of three gas sample streams.
. ......
Hydrocarbons not measured. ~
(2) . 2 opp~site burners on top level fir~d fuel lean (1/2 normal fuel rate).
(3)' 4 burners on ~op level fired fuel lean (about 1/2 normal fuel rate).
(4)
Estimated.
Electrical equivalent of boiler steam generation.
-------
- 126 -
6.3.4
Oil Fired Cyclone Boiler
Table 6-41 presents a summary of emission and operating data
obtained in testing Boiler L, a 400'MW cyclone fired boiler. This boiler
was originally designed for coal firing, but subsequently it was fitted
for oil firing and \\li11 also be equipped for gas firing in the near future.
The emissions from the two ducts sampled are given separate'ly in Table 6-41,
due to the wide differences in the gas compositions of the two du~ts.
Boiler L had limited operating flexibility. consequently, the
only operating variables studied in the field tests were load (full and
partial), excess air level, and simulated staged combustion. Analysis
of the NOx emission data indicates that at full load emissions averag~d
about 530 ppm, while a reduction in load of 38% (from 415 MW to-260 ~~v)
reduced NOx emissions by over 60%. This is a significantly larger NOx,
reduction than those measured in other oil fired boilers operated at
reduced load, and may be inherent to the cyclone firing design. Run 5
. was made- to simulate staged combustion (within the flexibility of this
boiler). Two upper level cyclones were fired on air only, while the
other six cyclones were fired at increased rates to maintain
load. This change resulted in an increase of NO~ emissions by ,about 507.
(206 to 310 ppm) , presumably because of the higher intensity firing of
the operating six cyclones.
It appears that NO emission~ from cyclone furnaces will be
difficult to control,becausexof their inflexibility. . Most of the combustion
takes place within the individual cyclone where low excess air, two-stage
combustion, and flue gas recirculation controls could not be tested with'
existing designs. However, dropping the load on the boiler may be an
interim solution' for such boilers if regulations restrict the allowable
level of NO emissions.
x
. .
-------
. ~
.;
TABLE 6-41
SUMMARY OF EMISSION DATA FROM BOILER L (400 MW. CYCLONE. OIL FIRED)
Flue Gas Compositions(l) and Temperatures
..
Gross Duct No. 1 Duct No. 2
Boiler No. of Dry Basis ppm, 3io 0" . Dry Basis ppm, 3'70 ° 2
Run Load Cyclones % Drv Basis.t.. Temp. % Dry Basis Temp.
No. (MW) Firing 02 C02 NO CO of 02 C02- -- NOx CO OF ° ,%(2»)
. 2' 0
~
1 421 I 8 4.1 12.2 548 8 610 2.7 12.8 572 6 666 2.1
I
2 I 410 8 4.9 11.4 505 6 615 4.3 11.8 497 6 670 2.7
I
3 I 255 8 4.6 12.0 214 -- 592 6.5 7.4 200 -- 652 I 2.2
I f
, .,
4 262 { 8 2.5 13.3 211 3 580 4.9 11.3 200 3 580 4.2
; I 111.2 3151. I j
j 6 (3)
5 I 275" I 5.1 1. 620 6.9 9.5 306 I 2 604 j 4.5
I !
I :
.
....
.. N
.....,
(1~
(2)
Average of four data points.
Each data point from composite of three gas sample streams.
(3)
Boiler 02 recorder data.
6 cyclones firing oil and 2 cyclones on air only to simulate staged combustion.
-------
- 128' -
6.4
Individual. Emission Results' on Coal Fired Boilers
Seven coal fired boilers were included in the field tests
consisting of two front wall, t~'IO horizontally opposed ~yall, two tangential,
and One cyclone fired unit. Coal fired boilers presented the greatest
difficulty in applying combustion operating modifications for NOx control.
Full load, uncontrolled NOx emissions from large, coal fired boilers.
ranged between 800 and 1500 ppm for wa 11 and cyclone fired boiler.s,
while tangentially fired boilers emitted about one-half o'f th~se level's.
Of the seven cQal fired boilers tested, combustion modifications resulting
in substantially reduced NOx emissions could be applied in only ~o of
the units. In both cases (one a front wall, the other one a tangentially
fired boiler), the combination of overall low excess air with staged
firing resulted in a reduction in NO emissions of over 50% and a 10.5s
in load rating of about 15-20%, comp~red with uncontrolled, full load
operations. The other five coal fired boilers could not be tested at
sufficiently low excess air levels to expect much improvement in NOx
emissions. In some cases this was due to directly observed, real slagging
. problems~ and in others it was due to a reluctance of boiler operators
to risk the occurrence of potential problems even for a limited period
of test time. The results of the field program on all the coal fired
boilers tested are discussed. in this section.
6.4.1
Coal Fired Front Wall Boilers
, Table 6~42 presents a summary of the emission and operating
data obtained in test"il1g Boiler M. This 175 1>fi-l, 16-burner, front wall
fired, pUl\lBriz~d Cr101. nabc0cl~ .:~d ~Jilccx boi.l~l. li.du a single dry-bottom
furnace with a divis10n wall. In additi?n to being representative ,of
medium sized, coal fired front wall boilers, this unit had two unique
features for field testing that favored its inclusion into our sample
of boilers to be tested. First, it was equipped with limestone injection
into the furnace for sulfur oxide emission control and second, special
water cooled probes were available for sampling flue ,gases at elevated
temperatures. The first of these features provided an opportunity to
check ,whether dry limestone injection could affect NOx emission's (perhaps
through catalytic decomposition activity at high temperatures), while
the second one enabled us to check whether the NOx concentration wOuld
remain "frozen" (as expected) between high temperature locations and
our usual sampling locations at 600-700°F. Due to the significantly
different concentration levels measured in this boiler, which were
caused by imperfect combustion control of burners ,the emission data.
are presented separately in Table 6-42 for each of the two ducts probed.
The average NOx emissions in each of the two ducts sampled
for each run are given in Table 6-43, arranged according to the statistical
experimental plan. All runs were made at a load of about 140 MW, in
order to obtain a direct comparison of staged combustion with normal
firing. Staged combustion was accomplished by operating the top row
of burners on air only, i.e., shutting down the pulverizer mill supplying
coal to the top row. Other combustion operating variables included in
the experimental plan were excess air level and position of the secondary
air dampers (relatively open vs.closed down). In addition to a complete
factorial design' with no limestone injection, a two-level, two-factor
latin square design was used with limestone injection. Although this
-------
129 -
complimentary latin square with limestone injection (to complete the
factOrial) waS also planned, mechanical problems with the limestone
injection system forced the cancellation of these planned runs. Runs 20
and"20a were made to compare the gas composition from duct sampling
locations just upstream of the air heater at about 670°F with those
sampled from the superheater section at 1480 to 1640°F.
-4. . .- .
. .
-------
I.
i
TABLE 6-42
SUMMARY OF EMISS ION DATA FROM BOILER M (175 MW, FRONT WALl.;, COAL FIRED)
! Gross I -. . -J I .---,- : Flue Gas component,s and
Bo~leri Steam Limestone Secondary! Excess IStag~n~ ., Left Duct
~ Load! Flow I Injection I Air Air! r."Drv BasJs I m %....02'. y...Basis~%.Dr
! MW :1031bs./hr.! 1031bs./hr. Dam ers Leve1(2)! . 02 C02 NOx' CO Tem .1 02
I "'-----r -
I Low I Yes 2.4 15.5 '318 j 54
I Low I Yes 3.7 14.0 383 I 61
!Low I Yes 4.1 15.0 296 !115
; Normal : Yes 3.9 13.9 415 j 46
,Low' No 3.9 15.6 587 i 99
I Normal ,No 5.1 14.0 670 1105
jNorma1 \ No 5.2 14.1 651 jl03
iLow 'Yes 4.0 14.5 356 1120
!Low Yes 3.6 15.5 I 237 1179
jNorma1 ,Yes 5.3 13.9 I 524 29
tLow ,No 3.3 15.1 676 I 44
:Norma1 'No 4.2 .14.3 650 II 20
lNorma1 : No 2.6 16.0 641 19
'Low I No 2.4 16.1 654 I 67
Normal: Yes 3.1 16.1,' 315 I 48 !
Low j Yes 12.3 16.5,264 j 50, I
Normal No 4.8 13.4,6311148 (3)1.
Normal No 5.0 13.0 I 697 1798 1
,Normal No I 4.8 12~91 705 11111(3)1
Run
No.
1
6
6a :
7
8
9
10
11
11a:
12 : 138
13 136
14 139 i
,
15' 148 I
16 1'.0
17 130 I
18 130,
19 140!
20 140:
20a 140
139 975
140: 978
137! 985
140. 975
140 I 975
139 i 970
141 i 9'70
138, 965
1,005
970
960
980
1,050
980
900
890
940
950
950
I
i
I
\
I
,
I
i
i
i
I
,
i
I
!
i
i
\
!
24
o
o
o
o
o
o
o
o
o
o
o
o
20
20
20
20
o
o
Closed
Closed
Closed
Open
Open
: Closed
i Open
! Open
i Open
i Closed
! Closed
Open
Open
Closed
Closed
Open
Open
: Open
~ Open
(1) Average of two data points for each d~ct.
(2)
(3)
Test program design.
694 j 6.1 12.4
721 !3.1 14.7i
695 !2.4,16.71
717 ; 6.0 ! 11.8
720 i 2.0117.21
701 ! 3.3 115.811
722 i 3.0 ! 16.1
652 ! 2.6! 15.9)
678 j2.1,16.81
660 1 3.9 : 14.6!
675 ! 1.3117.11
667 f 2.2 I 16.11
661 j 1.1117.1/
667 i 1.4 i 17.2~
687 I 3.2 f 16.41
671 ; 2.4116.8,
675 i 3.2! 15.1:
670 1 4.9! 12.8:
, ,
660 . 4.8112.8)
331 j 46
275 j 94
233 ! 86
286 i 79
468 i 95
654 ! 115
552 ! 96
244 1 396
213 i 938
335 i 41
512 j 37
513 i 19
482 i 36
455 ~ 92
232 (658(3)
197 i 96
494 t 168
696 ~ 728 (3)
708 11106(3)
Each data point from composite of three gas sample streams.
CO analyzer reading observed to drift during runs.
725
728
711
731
732
724
747
691
719
760
740
746
674
713
706
673
724
1480
1640
....
(..>
o
. .-.
-------
131-
TABLE 6-43
TEST PROGRAJ1 DESIGN FOR BOILER M-FIRING COAL*
( Average NOx Emissions Per Duct) ppm at 3% 02) Dry Basis)
,-posit10n ot
ISecondary Air
i Dampers
,
i
:(L1) No
! Limes tone
i Injection
(D1) Open
(D2) C10s ed
Down
"(L2)
I Limes tone
!
i
(D1) Open
(D2) Closed
Down
Injection
* Circl~d numbers denote
(S1) Normal
Firing
(S2) Staged
Firing
--
I(A1) Normal
i Exc. Air
! ...~,
r~ I 651,552
I~ 650,513
i 697,696
!~O\ 705.708
!@ 670,654 Itlr676,512 ~524,335
~) 631,494 (3'
r' ~.
!CD
I
(A2) Low
Exc. Air
(A2) Normal
Exc. Air
(A2) Low
Exc. Air
-------
- 132 -
Figure 6-14
NO EMISSIONS FROM BOilER M
x
(175 MW, Front Wall, Coal Fired)
800
700
Normal Excess Air.
Excess Air
600
II)
II)
~
co
>- 500
~
c
..
N
0
'~ 400
('('\
+J
11:1
E
0..
0..
.. 300
x
0
;;;:::
m
200
~ No Limestone Injection
fli3 Limestone Injection
100 .
o
o
Staged
Norma I
Firing Pattern
-------
133.-
The summary of emission data obtained in testing Boiler C
firing coal alone and mixed, firing of coal and gas is presented in
rable 6-44. Because of potential slagging and flame impingement problems,
the full effect of staged firing with low excess air could not be tested
on this boiler, for firing coal alone. A 40% reduction in load from
275 HW to 160 HW resulted in a 20% reduction in NO emissions.
x
Mixed fuel firing (2/3 coal and 1/3 gas) produced NO emissions
which were intermediate between the very high levels measured ~ith coal
firing and the somewhat lower but still high NO emissions measured with
x '
gas firing. (The data obtained on this boiler with gas firing alone have
been discussed in Section 6.2.)
The very high emission levels measured in this boiler are likely
to be a consequence of the furnace design. In this unit, the bottom row
of burners are located relatively closely to the flat bottom of the furnace
and insulating tile had been installed on the inside furnace walls up to
an elevation above the top row of burners. This boiler design was aimed
at maintaining wet bottom conditions under low load firing conditions
for easy removal of the slag.
6.4.2 ,Coal Fired Horizontally
Opposed and Cyclone Hoilers
Coal fired Boilers F, N, P and Q could be tested only with very
,limited cOUlbus tion op8raling modific<;1 tions. Consequently, none of ,the'
test programs conducted on these boilers resulted in significant NOx
reductions through combustion contr.ol. However, full load, uncontrolled
emissions were measured for the purpose' of developing representative
emission factors. In addition, the effect of operating these boilers
under reduced, load conditions on NOx emissions was determined. Tables
6-45 (Boiler F), 6-46 (Boiler N), 6~47 (Boiler p), and 6-48 (Boiler Q)
present summaries of NOx emiss~on data and boiler operating variables
for these units. In all cases, load reduction resulted in decreased
NOx emissions. However, the fractional decreases in NOx, were less steep
in general than those measured for gas firing at corresponding fractional load
levels. The cyclone fired Boiler Q showed the relatively highest sensitivity
of NOx emission reduction to load- reduction. In testing Boiler P, a
300 ~v tangentially fired unit, the air preheater was bypassed in Run
No.2 with a limited portion of the flow, resulting in somewhat,lower
NOx emissions than those prevailing under normal operating conditions.
. The emission data obtained on these and all
boilers ~ested in this study are discussed further in
report in the context of general conclusions.,
other coa I fired
Section 2 of this
-------
TABLE 6-44
SUMMARY OF EMISSION DATA FROM BOILER C
(315 MW J FRONT WALLt COAL AND MIXED COAL/GAS FIRED)
Operating Data Average Flue Gas components(l)
Fuel ~L) ' ! I
Gross I
Run (4) Boiler Coal ,
Load or Excess %. Dr Ba s is 3% 02 J Dry Basis'
, Staging (3) Aid5) 02 C02
No. " M\~ Coal/Gas ppm Nay
1 275 C No I . Low 3.5 15.4 1490
I
2 263 C No High 5.4 13.4 1480
3 I 160 I c No Low 5.7 12.7 1160
J
I I .
4 160 I C- No High 7.5 I 10.7 I 1200
I I !
.
i ! I
S I 193 I c Yes Low 4.6 13.7 I 1190
I t
I 6 ( 186 C Yes High 6.5 . ~ 11.7 I 1280 I
f ~
I
i 280 ' CIG 3.9 I 13.2 J 1240 i
lA ! I No Low I
i ! I .
, !
! 2A ( 280 CIG No 'High. t 5.3 12.0 1080 J
I c I
I '
. ;
i
' r I .
i 3A I 148 C/G No High I 6.1 11.7 I 970
I
I I
i I
f \
! I !
4A 145 ' CIG No "High 7.1 10.6 860
i I !
I !
I t i
SA 194 I CIG 3.2 I 630
Yes Low 15.0 1
6/1 193 C/G- High 5.4 12.3 "' 830
Yes,
~ "
,
t-'
U)
,p.
(1)
(2)
(3)
Average of 15 to 16 data points per run. Each data point from a composite of 3 gas sample
streams. (C6 and hydrocarbons were not measured in these runs.)
Mixed fuel firing: top row on gas, middle and bottom rows on coal.
Staged firing: No - equal amount of fuel fired in all three rows; Yes - fuel firing in
lean top row, fuel rich in middle and bottom burner rows.
One of two twin furnaces tested.
Test program design.
(4 )
(5)
-------
TABLE 6-45
SuMMARY OF EMISSION DATA FROM BOILER F
(600 MW, HORIZONTALLY OPPOSED, COAL FIRED)
- Operating Data Ave. Flue Gas ComDonents(l) Flue
Gross Fuel Heat. Gas
Run Boiler Load No. of . Rate Tons Rate(2) %. Drv Basis Ppm. 3%02 Dry Basis Temp.
--
No. MW Burners Coa1/Hr BTU /J::WH 02 C02 NOx CO of
1 563 24 200 9lB2 6.2 11.5 838 (3) 684
f. 2 462 20 167 9319 4.9 11.8 781 18 619
I 3 I 366 20 138 9755 4.7 11.4 621 21 563
4 359 29 137 9922 5.8 9.7 665 23 603
.....
w
VI
(1)
Average of 12 to 16 data points per run.
(Hydrocarbon not measured)
Each data point from a composite of three sample gas streams.
(2)
(3)
Data obta1n~d from on-line c~mputer of boiler.
Not measured.
-------
-
- j
Operating Date Ave. Flue
Gross I No. of No. of Gas Components Flue
Boiler Excess I Pulverizers Burners Burners on 1-D~ Basis~ (1) Gas
Fuel Data Steam Flow Operating Firing Air Only 0 C02 I NO~, ppm, Temp.
Run Load Air I %2 of
103 1bs. /hr. 103 lbs./hr. (2) Coal (3) ~ 37. 0,
No. I MW Leve 1.L
!. i ! I 731
l' ! 771 580 4590 Normal! 1 through 5 I 30 0 5.9 I 12.5 902
I ~ I '
I I I
! I I ! 908 i 725 !.
I . 2 I 785 583 I 4590 Normal 1 through 5 30 0 6.1 12.2 I I
I s I r .
. I f . i ,
' i I t ; ~ i i
I I i 1 0 11.2 I 767 658
i 12 . 577 448 3600 No rma 1 2 through 4 i 24 7.1 r
I ,
I f ~ ( I I I
! ! I 2 I I /
Normal 24 6 7.0 11.0 733 I 650'1
l3A ' 580 440 . 3600 through 4 t
. I I ! ! . I
' ! I . j \ 650 j
) I I
I f I 2 ! 18 12 6.9 10.8 723 ,
! l3B ~ 580 I 432 3600 Normal through 4 : ( I
! i "1 i ;
i ' I i I t i
i ,. ..
(1)
(2)
. (3)
-<..
TABLE 6-46
SUMMARY OF EMISSION DATA FROM BOILER N
(820 MW. HORIZONTALLY OPPOSE~. COAL FIRED)
......
w
'"
Average of 16 data points per run. Each data point from a composite of three gas sample streams.
Numbered consecutively from front top to bottom and rear top to bottom. .No. 6 pulverized feeding the six
bottom rear-wall burners was inoperative during the tests due to mechanical problems.
In Run l3A air only was introduced through the top row of the front-wall burners.
In Run l3B air only was introduced through the top row of the front-wall burners and through the bottom
row of the rear-wall burners.
-------
TABLE 6-47
SUMMARY OF EMISSION DATA FROM BOILER P
(300 MW, TANGENTIAL, COAL FIRED)
.
- Gas components(l)
Operating Date Average Flue
.- --...--..----
Gross Flue
Boiler Steam Flow Air Drv ~asis 3% °2,ppm, Gas
-j Load
Run . ~ain Reheat Excess A5r ?reheater Dry Basis Temp.
No. j MW 10 lb./hr. 1061b. /hr. Level (3 Bypass \}2 C02 NOX CO of
1 I 240 2.00 1.45 Normal Closed f 3.9 14.3 418 12 (2) J
I 2 237 1.87 1.37 Normal Open I 4.3- 13.8 395 23 557 )
I '
I 3 300 (2) (2) Low Closed 3.0 13.8 414 25 595
i
~
I I 1 I
4 I 300 2.30 1.85 High Closed . 5.6 12.0 568 24 720
I t I f
i 5 250 2.30 1.85 Low Closed f 2.2 15.5 301 67 i (2) I
! r - -,
.:-.
w
.......
(1) Average of 12 to 16 data points per run.
Each data point from a composite of three gas sample streams.
(2)
(3)
Not measured.
Test program design.
-------
TABLE 6-48
SUMMARY OF EMISSION DATA FROM BOILER Q
(704 MW, CYCLONE, COAL FIRED)
.- . I
I
Operating Date (1)
Flue Gas Components
hro~ I I No. of Dry Dry t I Flue
Boiler Feed Excess Burners Basis Basis I 3% °2» Gas
Load t Water Flow Air Firing I Dry Basis Temp.
Run ° C02 '
Staging(2) %2 ; NOx' ppm of
No. MW . 103 lb ./hr. Leve 1 Coal %
1 665 4,650 Norma 1 . No S 14 5.3 13.1 1197 628
! I
2 1 668 4,700 Normal No 14 5.3 i 13.2 1112 616
i I i I
3 ! 660 4,700 Normal Yes 14 5.4 I 13.0 1203 624
I I I
4 ! 545 3,700 Normal No t 14 5.3 13.3 t 886 594
j t : I
, t
! i
I I i
J 5 545 3,700 Normal Yes 14 " 5.1 13.6 I 915 610
i I I f I
i '
6 548 3,100 Normal Yes '.I 14 5.6 13.0 846 ' 612
, I
!
!-'
W
(X)
(1)
(2)
Average of 16 data points per run. Each data point from a composite of
three gas sample streams. CO emissions were not meas4red. Hydrocarbons emissions measured <1 ppm.
"Staged firing" simulated by operating top cyclone burners under highly fuel-lean conditions.
-------
TABLE 6-49
SUMMARY OF EMISSION DATA FROM BOILER 0
(575 MW, TANGENTIAL, COAL FIRED) (l)
I Avcraoe Flue Gas omonnentB.J} 1(: Flue ("..a
Coal ~urner Staglnl':;" j D3m,,~; 'Seu lnR lIurner{D Temp.
Boiler Cla.sl- Tilt Leve 16 Dry Oas ia 110.. npm CO. nnm
-
Gross Steam Air Superheat Reheat fier Degrees Excess , O~ CO) J~. 02' n.02' of
Run Load FtOli F lOll Temp. Temp. Setting (rom I "Coal AUX1li~ry Le~:f (6) Flring On Air
No. X'w' 103 1bs/hr 103 1bs/hr °F ....:L...- Hor {zonta 1 Air" AI. Coals Onlv Dry BaSis Dry P...ls
-
1 468 165 158 1030 1015 Hin. -30 Ye, Max. Hin. LOll 2,3,4. 1 2.4 16.4 235 26 582
2 470 164 155 1055 1005 Hln. +30 Yet Max. Min. LOll 2,3,4,5 1 2.2 16.1 319 130 607
3 462 161 155 1032 1005 Hin. 0 Yet Hin. Max. Low 2.3,4, 1 2,3 15.4 254 29 597
4 478 169 170 1025 1010 Max. -30 No lIin. Max. Norma 1 ALL 0 3.2 14.4 405 26 6@6
5 480 167 168 1045 1010 Hax. 0 No Max. Hln. Normal ALL 0 2.8 14.7 369 31 615
8 458 166 162 1020 995 Hin. -30 Yet Min. Max. Norma 1 2.3,4, 1 3.3 15.0 255 42 599
9 455 158 160 1042 995 Hin. 0 Yet Hax. Hin. Norma 1 2,3,4.5 1 3.6 14.8 251 45 601
6 464 163 150 1010 980 Max. -30 No Max. Hln. Low ALL 0 2.1 16.3 377 71 600
7 465 16] 151 1050 1005 Max. 0 No I'\in. Max. Low ALL 0 2.2 16.3 385 93 595
10 479 170 171 1022 1000 IIln. -30 No Max. IIln. Norma 1 ALL 0 3.0 15.8 453 (~) 612
11 480 170 171 1050 1005 Hln. 0 No IIln. Max. Norma 1 ALL 0 3.1 15.6 387 (~) 616
lOA 478 168 170 1070 1015 IIln. -]0 No Max. IIln. Norma 1 ALL 0 2.8 16.2 467 (~) 624
30 ]00 148 091 890 830 Hin. 0 No Max.' IIin. Low 2,3,4 0 1.3 17.2 253 (~) 497
31 ]00 137 092 894 833 Hin. +10 Ye,. Hax. Min. Low 2,3,4 1 1.7 16.5 195 (~) 527
32 320 140 101 905 840 IIln. +10 No Max.. Mln, Low 3,4,5 0 1.5 16.5 274 ~) 528
3] 310 1]9 ~OO 920 855 Hin. +10 Yet Max. Min, Low ].4.5 1 2.5 15.5 152 (~) 525
]4 306 137 091 935 877 IIln. +10 No Max. IIln. Low 1,3,5 0 1.5 16.1 266 (~) 527
35 320 138 092 9]8 893 IIln. +10 Yel Max. Min. Low 1,3,5 2,4 1.3 16.1 2]7 ~) 544
14 445 177 151 1005 968 Hin. -30 No Hln. Max. LOll ALL 0 1.9 16.7 364 15 581
15 450 176 155 1018 995 Hln. 0 No Max. liin. Low ALL 0 2.1 16.5 392 22 582
18 440 In 149 987 970 Hln. -30 No Max. Hin. Low ALL 0 1.9 16.5 401 16 574
19 440 174 147 1020 995 Hln. 0 No Hin. Hax. Law ALL 0 1.9 16.5 345 44 568
n 428 173 139 1010 972 Max. 0 Yel Max. Min. Low 2,3.4,5 1 2.5 16.5 192 46 589
12 430 173 138 1014 976 Max. -30 Yel Min. Max. Low 2,3,4,5 1 2.2 16.4 198 111 571
16 445 168 150 1005 965 Max. -30 Yel Max. Hin. Normal 2,3,4,5 1 3.4 15.3 240 45 600
17 455 169 16] 1025 996 Max. 0 Vel Hin. Max. Norma 1 2,3,4,5 1 3.2 15.3 239 49 601
20 420 155 138 915 965 Hln. 0 Ve. Max. IIin. Low 2,3,4,5 1 2.1 16.6 187 67 584
Z1 420 154 144 952 910 Max. 0 Vel Min. Max. Low 2,3,4,5 1 2.4 16.4 177 133 583
22 435 158 141 955 907 Max. -30 Vel t>\ax. Mln. Low 2,3,4,5 1 2.2 16.5 i97 89 584
23 452 168 153 962 915 Min. -30 Yet Hin. Max. Low 2,3,4,5 1 2.1 16.6 195 53 587
.....
W
\!)
(1) Only Furnace B of tVln-furnace boller ceaced.
(2) Staged firing accordin8 to burner patterna indicated In table.
(]) Average of four data polnta. Each data point (rom composite of
(4) CO noC measured. .
(5) Hydrocarbona measured <1 ppm.
(6) Test program dealgn.
Burner levela numbered fram top to bottom (see burner configuration shown in Table 4-51).
three gas sample atreaat9.
-------
- 140
6.4.3
Coal Fired Tangential Boilers
. /
A summary of the emission data obtained and the operating
conditions for Boiler ° are presented in Table 6-49. This large (575 ~M)t
corner firedt twin furnace Combustion Engineering boiler had considerable
flexibility for combustion control. The statistically planned t~st program
and average NOx emissions for each of the 24 runs made under essentially
constant load conditions are shown in Table 6-50. The combustion control
variables \vere (1) firing pattern (normal and staged); (2) burner tilt
(horizontal) up and dmm); (3) air damper settings (maximum "coal air"*
with minimum auxiliary air and minimum "coal air" with maximum auxiliary
air); (4) excess air level (normal and low); and (5) coal classifier
setting (maximum and minimum).
*
Secondary air in this installation is referred to as "coal air".
TABLE 6-50
TEST PROGRAM DESIGN FOR BOILER ° - FIRING COAL**
(NOx EMISSIONSt PPM AT 3%.02' DRY BASIS
(AI) . Normal
Excess
Air
(Cl~
(C2)
(S ) Normal
(TI)
Horizontal
Tilt
-(i)Y"'---(D --) _.
369
G)
Firin
...-.....-........-.-""..---.-
Air Dam er
(A2) Low
Excess
Air
(Cl)
(C2)
** Circled numbers denote run numbers.
Cl - Maximum, C2 - minimum classifier setting. .
Dl - "Coal air" dampers open, auxiliary air dampers closed.
D2 - "Coal air" dampers closed, auxiliary dampers'open.
Sl - Normal firing.
S2 - Staged .firing, top row of burners on air only.
Uncontrolled NOx emissions operating at 80-85% of full load
(normal firing and excess air) averaged about 405 ppm. . Low excess air
firing alone reduced NOx emissions by less than 10%. However, staged
firing with normal excess air reduced NOx emiss"ions by an average of
about 40% (246 from 405 ppm), and with low excess air firing by about
50% (204 ppm from 405 ppm). The overall average effects of burner tiltt
eir damper settings, and classifier settings on NOx emissions were small;
however, interaction effects were found to be significant, indicating
that for each combination of firing and excess ai~ there is probably one
optimum combioation of classifier setting with burner t'ilt and air damper
position.
-------
- 141 -
. The NO emissions measured in Boiler 0 under reduced load
conditions (300-~20 }M) with various patterns of staged firing are.
presented in Table 6-51. These runs were made to obtain information on
the effect of burner spacing and staged firing on NO emissions.
x
TABLE 6-51
TEST PROGRAN DESIGN FOR BOILER 0 ~ FIRING COAL
(REDUCED LOAD CONDITIONS - STAGED FIRING PATTERNS)
Run Burner Rmvs ppm NOy I
No. Firing Coal On Air Only ; JIo u2J, i
-.pry Bas~s I
I
I
!
30 2, 3, 4 None 253
31 2, 3, 4 1 195
32 3, 4, 5 None 274
33 3, 4, 5 1 1?2
34 1, 3, 5 None 266
35 1, 3, 5 2 273
, .
Burner.Configuration
In the reduced loa~, staged [iring testst all uth~r variables
were standardized, i.e., emissipn measurements were made at a minimum
coal classifier setting of +100, and air dampers at maximum "coa lair"
and minimum auxiliary air settings. Staged firing with the firing coal
reduced NO emissions from 253 to 195 ppm, or about 23%, compared with
firing the~e rows without overfi=e air. However, increasing the
separation between the operating burners in the bottom three rows
(3t 4t and 5) and 'overfiring with air in the top row resulted in
lowering NO emissions from 274 ppm to 152 ppm or about 45%. Intro-
ducing air fn Row No.2 between opera ting Rows No. land 3 actually
increased the NO emissions from 253 to 273 ppm.
x
A multiple regression analysis of all 30 runs made on Boiler 0
resulted in the following regression equation:
ppm NOx = 352 - 114 Xl + 0.00394 X ~ - 30.7 X3 - 14.1 (XlX4)
Xl = Staging (single stage-l, staged firing-2)
X2 = Load (MW)
X1 = Classifier setting (mimimum-l, maximum-2)
Xi. = Air damper setting (maximum "coal air"/minimum
auxiliary - 1, minimum "coal air"/ maximum
auxiliary air-2
where:
The multiple correlation coefficient was found to be 0.94, indicating
that 88% of the variation in NOx emissions were related to, or explained
by the independent variables. The stand~rd er~or of estimate was 31 ppm
NOx for these tests.
-------
- .142 -
6.5
Steam-Side Analyses by Boiler
Manufacturers on Coal Boilers
For the coal fired Boilers 0, N, and Q, the respective manufacturers
. of these boilers (Combustion Engineering, Foster Wheeler, and Babcock and
Wilcox) par.ticipated in the emission test programs. Their role was to
provide advice 00 the limits of operability of the boilers when combustion
modifications were to be tested for NOx emission control, to pre-check
the boilers prior to testing,and to asseBS the consequences of combustion
modifications on thern~l performance, boiler operability, amount of
. unburned carbon, and other boiler operating variables.
. .
The findings of the boiler manufacturers in connection with
our Boiler Test Program are presented in their reports given in Appendix B
of this report. During the short duration tests carried out in these
studies, no noticeable effect could be detected on boiler operability
resulting from combustion modifications, such as the Successful application
of low excess air firing and two-stage combustion to Boiler 0, where NOx
emissions were reduced by over 50%. Carbon in the fly-ash showed no
increase, and no slagging problems were encountered. Because of the
inability of the boiler operators to apply combustion operating
modifications for NOx emission control to the horizontally opposed
Boiler N, and the cyclone Boiler Q, respectively, the manufacturers'
reports on these units essentially reflect normal operating conditions.
. Clearly, these evaluatioHs are Qf a preliminary riature, and
the findings on Boiler 0, while promising, should not be construed as
demonstrated technology. Long-term evaluations in cooperation with
'boiler operators and manufacturers will be needed to define and demonstrate
the applicability of combustion modifications to the operation of utility
boilers for pollutant emission control.
-------
- 143 -
7.
RECONHENDATIONS FOR FUTURE UTILITY BOTLERTESTING
.
As discussed in previous sections, the msjor problem area in
. reducing NO emissions by cOmbustion modifications is to apply these
techniques ro coal fired boilers. In spite of the excellent progress
made in controlling emissi.ons from gas and oil fired boilers, detailed
demonstration of the technology sti..l1 a Iso rema ins to be performed for
boilers fired with these fuels.
The data obtained in Phases I and II of our Systems Study of
Nitrogen Oxides Control Methods for Stationary Sources provides a sound
basis for the selection of boiler types to be tested in the future
Table 7-1 shows the number of boilers of each type which appear to be
the logi.cal choice for ftlture field testing. .
TABLE 7-1
NUMBER AND TYPES OF UTIL1TY
BOILERS TO BE TESTED IN A RECO}~1ENDED BOILER TEST PROGRAM
Fuel Fired
Type of Firing Coal Oil Ga.s Expected Total
Wall 2 to 3 (4) 1 .to.2 (6) 1 (6) 3 to 6 (16)
or
Tangential 3 to 4 (2) 1 t'o 2 (2) 1 (1) l;. to 7 (5)
Cyclone 1 to 2 (1) None. (1) (0) 1 to 2 (2)
Vertical (0) (0) (1) 0 ( 1)
Expected Total 6 t9 8 (7) 2 to 3 (9) 1 to 2 (8) 9 to 12 (24)
Note: Numbers in parenthesis indicate the number of boilers tested in
Phase II Boiler Test Program on each fuel.
Major emphasis should be placed on coal fired boilers (6 to 8) with oil
next (2 to 3) and gas fired boilers least (1 to 2). Wall fired and
tangential boilers should be given equal emphasis. One or two coal
fired cyclone furnace boilers may be tested if sufficiently flexible
boilers can be located and arrangements with the owner-operators can
be made.
The prime factors evaluated bv fuel a~d type of firing in de-
veloping Table 7-1, were (1) amount of Upited States NOx emissions, (2)
difficulty of NOx emission reduction by combustion modification, (3)
extent of field research and demonstrated success in NOx emission
reduction, (4) operating flexibility, and (5) relative number of large
size bo~lers in. each group.
-------
- 144 -
Coal fired utility boilers are the largest single source of
stationary No,,; emissions in the V..S., Le., 3 million tons emitted in 1970
compar:d to 0:5 million tons for gas and 0.3 million tons for oil firing. '
Coal fued bo~lers have experienced very limited field testing, with less
success in NOx reduction compared to gas fired boilers, while oil fired
boilers are in an intermediate position. The operating flexibility of coal
fired boilers is generally less than that of oil fired boilers, with gas
fired boilers generally having the greatest flexibility. Tangentially fired
boilers have m~re flexibility, (for example, tilting burners and primarv
to secondary a~r damper settings) than wall fired boilers. Cyclone furnaces
have the least flexibility, especially when firing coal. The numb~r of
boilers reported in Esso's steam electric plant survey (1) generating over
2 million pounds of steam per hour by fuel and type of firing are: Coal,
40 tangential, 24 cyclone, and 16 wall fited; Gas, 9 tangential, 18 wall,
1 cyclone fired; and Oil, 4 tangential and 6 wall fired.
The coal types to be considered for future testing should.
include Eastern bituminous and sub-bitum~nous, Midwest bituminous and
Western low-sulfur bituminous and lignite coals. Oil types to be
considered include typical oils having low and very low sulfur content,
low and high nitrogen content, and low and high ash and metals content.
The basis for selecting specific boilers for testing within
. each of the fuel type groups should include the evaluation of many operating
factors, in addition to being representative of current design practices
for large utili.ty. boilers. .
Operating flexibility is a prime selection factor. Thus, designed
flexibility (equipment for flue gas recirculation, air ducts for over-
firing with air, control .of air and fuel to individual burners, tilting
burners, etc.), operating flexibility (ability and willingness to fire
with low excess air, to reduce loads, and to employ staged firing), and
fuel flexibility (range of fuel types and grades) should be evaluated.
In addition,. the boiler operators' willingness to cooperate by providing
proper sampling access, assistance in obtaining fuel samples, good
supervision for faster change in operations, research-minde1ness and
experience in NOx control would be evaluated. Obviously, the boilers
selected must be in good repair .and have the proper instrumentation and
controls so that proper data for fuel usage, combustion and steam side
analysis can be obtained. The continued cooperation of boiler manufacturers
and boi~er operators should be obtained to help in the boiler selection
process.
The basis for selection of individual boilers in cooperation
with boiler manufacturers and boiler operators has been discussed above.
However, the order in which the selected boilers are tested is also an
importan~ consideration. The best approach should aim at the objective
of obtaining the required test results with maximum efficiency. The
normal cycle of planning, testing, and analysis of results should be
-------
-
145 -
used for each major group of boil~rs. Thus, testing of a coal fired
tangent~al boiler would be followed by testing of a wall fired boiler and
of a cyclone fired boiler, before testing the second coal fired tangential
boiler. This would allow the -necessary time for planning the second series
, of tangential boiler tests bas~d on a more thorough analysis of the initially
tested tangential boiler. In addition, the relative desirability of testing
a third tangentially fired boiler compared to testing ,a third wall fired -
boiler can be properly evaluated. Thus, full benefit of cumulative experience
and information can be taken at each planning cycle.
Since it is desirable to test representative types of coal and
oil fuels that are fired in different geographic regions of the United
States, it is also desirable to use the concept of cluster sampling in
order to minimize travel time. Consideration should be given to testing
in fringe areas where different fuel types can be supplied to the same
boilers.
Thus, the proper selection and efficient scheduling of boiler
tests depends upon having a large backlog of suitable boilers of each
fuel-design group available for testing. The cooperation of boiler
manufacturers and boiler operators which contributed to the accomplishments
of the present Boiler Test Program would be needed for initia~ planning
and periodic updating of future field testing efforts.
The experimental program to investigate NO emission control by
changing operat~ng variables should utilize the knowledge and experience
gained in our Boiler '!'est !>rograr:l. ¥]itb the c.ooper-atian of boiler.
manufacturers and boiler operators, a systematic planning process should
be used to assure full exploitation of. the operating flexibility o~ each
boiler in an efficient manner.
It appears to be generally desirable to hold an initial planning
meeting at the station with all parties concerned in order to obtain
accurate, up-to-date information on operating flexibility, boiler
condition, scheduled overhaul periods, data acquisition and logging
facilities, availability of sampling ports, etc. A formal l,ist of the
operating factors, their practical range, how they are interrelated, the
time it takes to c.hange from one operating level to the next one and the
potential operating problems or limits related to each variable should be
agreed upon. Potential experimental programs should be considered ftom a
practical operating standpoint. The expected number of test runs
achievable per day will be then established. Problems of accurate
measurement of key variables such as fuel burned and air flow should be
considered, as well as determining how to obtain representative samples
of the fuel burned.
The information obtained at the initial planning meeting would
then be used to develop a proposed test schedule, listing the test runs to be
made each day, with the specific levels of all operating variables. This
plan must be based upon sound statistical experimental design principles
and incorporate all practical operating-limitations. Thus, provisions
should be made for blocking the tests to minimize the effect of unavoidable
changes from day-to-day, and from fuel batch-to-batch on the variables of .
-------
. .
- 146 -
inierest. Sequential blocking should be planned so that advantage can be
taken of current information on variables showing no effect or unexpected
effects in scheduling the next series of tests. The Box-\Vilson strategy
of designing initial tests in the form of efficient fractional factorial
desigr.s, using the method of "steepest ascent" to procede rapidly to
the operating region of maximum initial improvement and then pl,anning the
necessary runs for full exploration of the optimum region should be considered.
The proposed test s checule at each boiler should be reviewed
with all concerned prior to actual testing. At this time, possible
improvements in the proposed program can be evaluated, adjustments can
be made in line with current operating or fuel restrictions, and thp.
responsibilities of each party during the experimental program ca~ be
clearly established. In addition, the necessary boiler pre-testing
inspections, checking of instrument calibration, measuring air leakage
into flue ducts, calibration of coal scales, development of. data
recoraing forms, etc., can be performed. A comprehensive check list
developed from our Boiler Test Program should be helpful in assuring that
all necessary planning details have been accomplished.
Carrying out the test program efficiently can be greatly
, simplified due to the detailed planning and preparation for testing:
carried out jointly with boiler manufacturers and boiler operators. Thus,
the agreed upon. operating program, detailed data recording forms,
communication links with all parties, alternative experimental plans
(i~ case" of unplanned changes in loads, fuelH or equipment), arrangement
for manpower for taking fuel samples, ,overtime, provisional, etc. would provide
basis for rapid accomplishment if all proceeds according to plans, and for
rapid decisions on necessary changes to plans.
. Flue gas samples are to be taken to represent planned steady
state furnace and steam conditions. Thus, it is necessary to determine
by careful observations of furnace flames, control room instruments and
flue gas measurements that the operating variables .such as load, excess
air, exhaust recirculation rates, air damper settings, etc. are at their prop.er
levels for each experimental run. The exercise of experienced judgment
is extremely useful at this point, as a few illustrations will demonstrate.
Low excess air has been demonstrated to be an effective NOx control
variable as well as providing improved boiler efficiency and reduced main-
tenance due to low temperature corrosion in oil and coal fuel boilers.
Thus, in testing low excess air firing (in combination with other control
variables), it is desirable to lower the excess air as much as practical.
The practical limit should be determined by furnace observation to check
burner flames (pattern, impingement on walls, color, stability, etc.)
slagging conditions, damper adjustments; control room checking of fuel
and air flows, oxygen in flue gas measurements, steam temperatures, wind
box pressures, and instrumented van checking of flue gas components across
the sampling points. Detailed recording of operating and emission.
data should be started only when all checks indicate proper levels, steady
conditions and adherence to proper safety and other operating practices.
Other operating variable settings requiring the same detailed checking
and experienced judgment during testing are burner tilt, primary and
secondary air damper settings, degree of staged. firing, and extent of
flue gas recirculation. .
-------
- 147 -
In a few carefully selected cases, it would be desirable to
determine the effect of 'electrostatic precipitators on NO emissions,
by sampling before and after'the precipitator. Similarly~ the effect of'
combustion modifications on particulates before and after the precipitator
should be considered.
The length of each steady state run must be sufficiently long so
that accurate and representative, gaseous and particulate emission can be
determined. Experience has demonstrated that 30 to 45 minutes of
continuous measurements covering 12 sampling points are adequate for
gaseous components. Particulate measurements are not continuous but
are cumulative, and generally require longer sampling periods for adequate
representation of an operating condition. Thus, a two-stage .program may
be the best approach. First, run a series of designed experimental runs
for gaseous components to determine the operating region of best NOx
control. . Second, make relatively long baseline and NOx control runs to
repeat the measurement of gaseous components but primarily to make particulate
measurements as well as slagging and corrosion observations.
The actual results of each block of experimental runs should
be compared to the results expected on the basis of both theoretical know-
ledge and practical experience. This preliminary analysis should then
provide a flexible basis for curtailing or expanding experimentation where
qesirable,. since the original b~ocks should have been designed to be
augmentable. .In addition, it is desirable to take advantage of unplanned
changes in operating conditions and equipment availabilities where possible.
-------
- 148 -
8.
REFERENCES
1.
Bart"()k, \oJ., Crawford, A.R., Cln1ningharn, A.R., Hall, H.J., Hanny, E.H.,
and Skopp, A., "Systems Study of Nitrogen Oxide Cont rol Methods for
Sta1:ionary Sources", Esso Research and Engineering Company, Final
Report No. r.R-NOS-69, Contract No. PH 22-68-55 (NTIS PB 192 789),
{November, 1969). "
2.
Fisher, G.E., and Huls, T .A., "A Comaprison of Phenoldisulfonic Acid,
Non-Dispersive Infrared, Saltzman Methods for the Determination of
Oxides of Nitrogen in Automotive Exhaust", J. Air. Poll. Contr. 'Assoc.
~, 666 (1970).
3.
Bartok, W., Crawford, A.R., and Skopp, A., "Control of NOx Emissions
from, Stationary Sources", Chern. Eng. Progr. g, 64 (1971).
4.
Bartok, W., Crawford, A.R., Cunningham, A.R., Hall, H.J., Manny, E.H.,
and Skopp, A., "Stationary Sources and Control of Nitrogen Oxide
Emissions", Proceeding of the Second lnte mational Clean Air Congress,
pp. 801-818, Academic Press, New York (1971).
5.
Bre~n, B.P., Bell, A.W., Bayard de Volo, N., Bagwell, F.A. and
"Rosenthal, K.; "Combustion Control" for Elimination 0 f Nitric Oxide
Emissions from Fo'ssii Fuel POvler Plants", Thirteenth Symposium
(late rnational) un COlllbustion, pp. 391-403, The Combustion Institute,
Pittsburgh, 1971.
6.
Bagwell, F.A., Rosenthal, K.E., Teixeira, D.P., Breen, B.P., Bayard de
Volo, N., and Kerho, S., "Utility Boiler Operating Modes for Reduced
Nitric Oxide Emissions", J. Air Poll. Contr. Assoc., £l., 702 (1971).
7.
Sommer1ad, R.E., \oJelden~ R.P., and Pai, R.lI., "Nitrogen Oxide
an. Analytical Evaluation of Test Data", presented at American
Conference, 33rd Annual Mtg. Chicago (April, 1971).
Emission.-
Power"
8.
Duprey, R.L., "Compilation of Air Pollutant Emission Factors,
PHS Publication No. 999-AP-42, 1968.
-------
149 -
APPENDIX A
SAMPLING-ANALYTICAL VAN DETAILS
This section of the report contains illustrative photographs
of the exterior and interior of ~sso. Research and Engineering Company's
sampling-analytical van used for emission measurements in the Boiler Test
Program.
-------
- 150 -
EXTERIOR VIE\{ OF SM-[PLD~G-ANALYTICAL
VA~i ()~ LOCATION
n _.3=1"" '.'
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PORTN3LE INSTRlNENT CABINET INSIDE VAN
Pill-iPS, REFIGERATIONS AJ.~D NOZ SENSOR
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- 160 -
APPENDIX B
This section 0 f the report presents the data supplied by two 0 f
the boiler manufacturers, Combustion Enginee~ing and Babcock and \.Jilcox,
who participated in the test programs at Boilers 0 and Q, respectively.
Their reports have been incorporated directly, \.Jith the exception that the
.boilers have been coded instead 0 f designated by name. Because it was not
possible to explore combustion modifications for NOx emission control at
Boiler N, Foster-Hheeler did not perform a steams ide analysis on that uni t .
-------
. - lql -
APPENDIX B-1
BOILER 0
MONTHLY PROGRESS REPORT NO.3
JUNE 1, 1971 TO JUNE 30, 1971
ON
SUBCONTRACT NO. ESC-12
BOILER FIELD TEST SUPPORT
TO
ESSO RESEARCH AND ENGINEERING COMPANY
. PRIME CONTRACT CPA 70-90
PREPARED FOR THE
OFFICE OF AIR PROGRN1S
CT~!rI ~'r'J ~\TI !"\ut! 1'(1 .1"'?27
..\,." .1 ,,1 t II.,,"'" 'V,"-
JULY 10, 1971
COMBUSTION ENGINEERING, INC.
.FIELD TESTING AND PERFORt~ANCE RESULTS
1000 PROSPECT HILL ROAD
WINDSOR, CONNECTICUT 06095
(203) 688-1911
J. D. CA VE RS
, .
-------
I .
- 162 -
SECT! ON I
---~_.-
PURPOSE ArID SCOPE
Field test support (subcontract) to the oxides of the nitrogen program nOl'I
being conducted by Esso Resc(\rr.h and Engineering Company under contract flCPA 70-90
at Boile r O.
SECTION II - PROGRESS
Labor~tory Analy-sis
Ultimate coal analyses I'lere performed on four composite and tl'lO single coal
, samples at the C-E Laboratory in Hindsor, Connecticut. The samples were analyzed
using the ASTM 0271 procedure with the results tabulated on Sheet 81.
Unit Output, Efficiency, and Net Heat Input Calculations
Unit output was calculated by the heat balance'method using test, board, and
computer data: The method and results are listed on Sheets 82 and 83. The results
of the unit efficiency calculations using the heat losses method are listed on
Sheets 82 and 83 with the procedure explained on Sheets 84 thru 86. Unit efficiency
was calculated with and without the reject loss included in the total losses.
Heat input from fuel was determined using the efficiency (W/D reject loss)
divided into the unit output.
The net heat input to the furnac~ is the sum of the heat input from fuel and
the heat credits and losses as listed on Sheets 82 and 83. A sample calculation
of the credits and losses to the heat input from fuel is shown on Sheet 87.
A plot of efficiency (H/O reject loss) versus main steam flm'l (adjusted) is
SiiO\'ln on'S.beet 88. ies~ efficieilcies are compani!d 1..0 the average efficiency (HiO
reject loss) as calculated for the. performance tests, Aug., 1962. The plot sho\'IS
tha~ two stage combustion does not adversly affect unit efficiency.
. Board, . Computer and Test Data
The test data is summar'ized on Sheets 89 and, 310. The coal scales \'Iere only
used to determine ~1 load output per furnace as they were not considered accurate
enough to determine heat input to furnace. . Rehet1.t 'flot" \'/aS determined by using
the plot on Sheet 811 which was obtained from performance test data, Aug., 1962.
Main steam flow and first stage pressure were adjusted to specified nozzle condi-
tions and are plotted on Sheet 812. This plot was used as a check on the accuracy
of the main steam flow. The values designated by the 0 symbol fall significantly
be10',', the curve; this is due to the very 10\'1 'superheat outlet temperatures at Y1hich
the boiler was operating during these tests. The gas and air flows are tabulated
for each test \"ith a sample calculation sho\'m on Sheets 813 thru B16. 80ard .and .
comp~ter data are tabulated on Sheets 817 thru 822.
Carbon Heat Loss Variation
A plot of percent carbon heat loss on a test basis with respect to changes
in percent 02, degree nozzle tilt, and superheat outlet temperature is shown on
Sheet 823. For all high load tests (four and five mill operation) except Test
20 the carbon heat 10s5 is below .30 percent.. The high carbon heat 10s5 (.74
percent) obtained on Test 20 was due to the c1ean furnace walls (note drop in
-------
- 163 -
superheater outlet temperature) \'/hich allo\'/ed for an increase in furnace \'/a11
absorptio~ rates and reduced flame temperature which reduced coniliustion efficiency.
Lo\'l load tests (three mill operation) I'lere performed after the outage and
the high carbon heat loss for Test 30 is due to the clean furnace walls. The
carbon heat loss for Tests 31 thru 33 decreased to the expected level as the
furnace became di rti er. Tests 34 and, 35 \'lere performed I'lith the #1, 3 and 5
mills in service. Combustion efficiency decreased due to the large spacing be-
tween the fuel nozzles. The combustion efficiency improved on Test 35 I./hen
auxiliary and primary air \'Ias admitted bet\>/een elevations #1 and 3.
, Effect of Furnace Cleanliness on Four and Five 11ill Operation
All furnace cleanliness data was obtained through visual observation of the
furnac~ wateli'/alls. A plot on Sheet B24 shOl'/s superheat outlet temperature ver-
sus percent 02 \'lith changes in nozzle tilt, mills in service, and furnace clean-
liness. ' ,
With heavy slag (3 to 4 inches) on the furnace walls, higher temperatures
were obtained at horizontal tilt than at minus 30 degree tilt. In both cases, the
temperature increased as percent 02 increased due to an increased mass gas flol'l.
There vias no change in temperature betvleen four and five mill operation as the
heavy slag prevented a substantial increase or decrease in furnace absorption rates.
When the slag on the furnace walls was light (1 to 2 inches) and four mills
in service at horizontal tilt, the outlet temperature i,ncreased as percent 02 in-
creased. At minu~ 30 degree tilt, a single point shows that at a high percent 02
the mass ~as flOl.J effect overrides the minus 30 degre~ tilt effect as the tempera-
ture ,did not decrease. With five mill operation and 10\'1 percent 02, the spread
bet\'Ieen minus 30 degree and horizontal tilt is shown by single points. The effect
. shown here is that greater furnace absorption occurs with the minus 30 degree tilt
due to the increased gas residence time in the furnace which decreases the tempera-
ture of the gas to ,the superheat sections.
During the short duration of each test in this test series, steam temperature
characteristics and furnace slagging conditions were unaffected by four mill (\'/ith
overfire air) operation.
Unit Inspection
An inspection of the nozzle compartments and the windbox was performed after
the test period with the results shown on Sheets 825 - 828. .
The nozzle tilt at horizontal and minus 30 degree positions were satisfactory
although a few linkages were broken. A plus 30 degree tilt could be obtained in
the rear corners but not in the front corners due to binding linkage's. A majority
of the tests were performed at either horizontal or minus 30 degree tilt, therefore
the unavailability of the plus 30 degree tilt in the front corners is of no con-
sequence. '
The windbox dampers in the "full open" position were operating satisfactorily
except the bottom five compartments in the right front corner \'lhich remained in a
fixed po~ition due to a broken linkage. The leakage gap measurement indicates
that some of the dampers \'Iere not' closing comp'lete1y \'Ihen the damper control \1aS
in the "full closed" position.
-------
- 16l, -
Nozzle Air rlo\'l Distribution
-----_.._..,.._---_._~--------
II, nozzle ai)' flOl'/ dist)'ibutio'n ptogrC11n \'/as )"un \'Iith, the results tabulat:!c! on
Sheet 829. This calculation \'laS n1Z1c1c .u's'ing desi91l specifications fOt" \'/incJboy.
and nozzle cO:;ipadnlent geometry. The calculated petc'~nt theoretical air to the
combustion 70ne is plotted versus PPM of NO, adjusted to 3 percent 02, on Sheet.
830. This p'iot sho\'/s that NO decl't:t!ses as percent theoretical air to the burner
zone decreases.
f\ tabulation of the \.lindbox and nozzle compa)'tl11C'nt geometry used in the cal-
culations are given on Sheet 831.
Pulverizer Fineness
ft. tabulation of pUl'!2rizer fineness ('!t four classifier settings are shm.:n
on Sheet 1332.
SECfION III ~ CURRENT prOBLEMS
At the present time there are no ptoblems that I'lill interfer'e l'Jith the comple-
tion of data analysis and reporting.
SECTION IV - FUTURE WORK
Thi.s 'is, the final progress report on .subcontract
commitment to th i s contracti s fi ni shed, shaul d there
and/or interpretiJti O~ 0f the test delta or perfoy'rnJncc
the \'/I:-i tel'.
ESC-12. Although CEls
be need for clarification
rcsul ts, please contact
., ."'; J
// (/, /
(/ ,,- ..:....~. /..'" /"'/
:f /(, LL"~<
J. D. Cavers
JDC/s1
Attachments
-------
Baile r 0
Cont.ract. 16357
Project. 900096
Combustion Engineering, Inc.
Field Tesling and
Pert'ormance RelNlts
UL TQMATtE FUEL AIN]A!LVS[E~
COHPOSITE PROXIMATE. ANALYSES COXPOSlTE ULTlMAT~ ANAI.Y:>ES
AS IU1:MVED AS RECEIVED
Volat.ile fixed
Hobt.ur. Hat.t.er Carbon Ash HHV Moist.'.Lre Carbon Hydro gen Oxygen Nitrogen Sul!ur Ash HHV
~ ~ ~ ---L .L eTUjLB % -L % -L '/. -L .L BTUjLB't
1,4,8,9, ....
12,16,17, 7.5 34.6 43.3 14.6 11, ~.6O 7.'> 61.3 4.3 7.1 1.5 3.7 14.6 14,369 '",
'J>
22,23
! . 5,6,10,11,
13,14,18,19, 7.9 34.4 39.9 17.8 10,500 7.'~ 57.8 4.1 7.4 1.3 3.7 17.8 14,260
30,31,33
2,7,21,32 7.6 35.3 41.1 16.0 11,010 7." 59.5 4.2 7.7 1.1 3.9 16.0 14,481
3,15,35 8.1 35.2 39.3 17.4 10,600 8.1 57.3 3.8 8.3 1.4 3.7 17.4 14,348
20 9.9 35.0 39.9 15.2 11,020 9.'~ 60.8 4.4 4.6 1.4 3.7 15.2 14,842
3- 7.0 32.5 37.5 23.0 9,670 7.0 53.5 3.8 7.1 1.3 4.j 23.0 14,005
*I!KV calculat.ed on moist.ure and aah tree basie.
SHEET B1
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Boile r 0
Caot.rac~ 16357
Pro.)8c ~ 'iC)l.()94
C",,!>.IoUon W1C1noor1Ag. Ioc.
FieLd. Too1.~ e.aS
p..tormr.c,;o Bosulte
UNIT iEFFOCUSNCY AN8d3
NET HEAT D~PU-r CALCULATfiCNS
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17. C=J,.~ ...i1 f-:-U'W"8 P:!lG 428 4:24 414 456 '.47 1,22 417 418 408 I,J8 433 iJ)J )97 :.18 I.1B
18. (,::>:4 l\11 Tea;;:;. r 1>15 623 1>19 630 !~ f:JJ7 6Jl 620 b27 622 4)2 642 6)8 6J3 656
19. Cold r.ri Ectt"..a..l.py 0'. () H 1)12 1)17 IJ15 1319 U27 1)00 1)22 1)15 lJ20 1311> 1322 1.330 1328 1321. 1)36 !-'
20. :tr:u Prcul.U'e PSICI J67 )70 )62 )78 '160 365 :;65 )S5 JSO 37S 375 )45 )l.S 3':>0 305 0\
21. :<.liv T~:.p. F 1024 ~99 lOCO 1018 :t1...\ 981> lC13 lOCO '1'15 9q1 lC11> ?IJ'I 9$6 968 lOCO 0\
22. aHV k:r.&lP7 q; .@ ani /1.B 15)5 1523 lS2) 15J2 1 ':<1 1516 i530 1:'21 1521 1H8 IS32 1518 151S '1506 1523
2J. u,n..1py I>W~ ~~ H 223 ~6 208 213 ~1{}2 200 208 201> ' 201 3)2 210 188 188 182 107
2~. !ot.o.l ii..'i .u:.. 2 1 e 10~rJ/HR .28':'.9 256.S 2;1. 7 278.0 2/.1..1 267.3 2S8.4 256.0 2AS.7 268.7 272.5 228.0 225.6 2.<9.8 2)S.2
25. M Spre.7 fl?w . 1 U!/HR' 0 27.0 10.') 0 1:.. 5 0 10.0 0 8.0 0 10.0 0 0 0 0
21>. ~ 5;:.r0\7 Preuure P51G 1500 1500 lS{o 151;0 1;00 1500 15CO 1500 ISCO 1500 1 s<:o 1500 1500 1500 1500
27. iUi 5t':"h1 Taap. r )51 'SJ 35J 354 352 )50 345 J46 J44 360 J5e J21 320 3:13 32J
28. ~-i! &pray I.J>n.'ll~ ~ @ ani /LB 325 J21> 32' ).8 ,~5 32Jo 318 319 317 J)4 )32 294 21) 296 2\'1>
29. r.ot,...1;oy DH:." . ~ H 1210 1197 11~'/ l204 1~:' 1192 1212 1202 1204 1lW, 1200 1224 122) 1210 1227
30. 'roa.l it., 3;:.:....,. 8. 13 106e1\1/HR 0 )2.) 12.0 0 l'i;5 0 12.1 0 9.6 ,0 12.0 0 0 0 0
31. 1'otu liT .boor-be4 b1 Uer ~ .3 . @ . ~ io~rJ/HR 1938.5 1952.3 lS29.2 1955.7 '201;;.9 1871>.7 1'116.1 1854.1> 1849.4 191>1.7 2003.' 1758.5 1740.4 181S.3 111)2.3
f.FY!CIU.cy - r.E..L! W:;o!:.S'>!I.TI>JD
Dry fA. L..ou 1> ).88 ).76 3.1>9 4.07 4.07 '.86 '.87 '.91 ).97 4.15 4.24 3.56 ).S7 3. S) ,.48
~l.tcr. in jir Loa. 1> .09 .09 .09 .10 .10 .09 .09 .09 .10 .10 .10 .09 .09 .08 .08
Mo11\.W'8 tr:.a. F~.l 1.0.. 1> 4.62 4.58 4.42 4.59 4.7) 4.7J 4.S7 4.59 4.59 4.76 4.77 1..56 4.70 ~.70 4.~9
Carbon Hu,t, 1..0.. 1> .27 .19 .14 .~ 05 .10 .06 .02 .08 .07 .rY/ .06 .10 .12 .14
N.cHat.ioQ Loa. ~ .22 .22 .23 .22 .21 .22 .~6 .23 .23 .21 .21 - .2A .2.4 .2:; .23
Heat i-cn in '11 Aah " .05 .05 .06 .OS .06 .06 .05 .05 .05 .06 .(1/ .05 .06 .06 .06
..h P1~ Lou 1> ~ ----.u ~ ---'~ -~, ~ -22. -.:6l --a.U ~ ----?d --.....u --a.U ~ ~
Tot..&.l 1.08~U 1> 9.36 9.2l. 8.86 9.29 ~.4J, 9.28 9.08 9.12 9.25 9.59 9.bB 0.79 8.99 8.9~ 8.60
aeject- ~H " _.:ti. ----.21 --.3l. ~ J,.2l. .J.&I. ~ ~ ~ -...li ~ -W!1 .J..J.j --..e~ ~
Tot'll "0.". (1",,1. R.J.o~ Lo..) 1> 10.20 10.16 9.03 11.11> U.12 ' 10.89 10.06 10.;>~ 10.)8 10.46 10.2'/ 10.40 9.80 9.45
Lf(101..,01 ("/0 iioJ"~ 1.0..) 1> 9O.bl. 90.76 91.1.4 90.71 90,51> 90.72 90.92 90.88 90.75 9O.U 90.32 9i.21 91.Cl 91.06 91.40
Klti010ncy (.. a.Jo<:~ 1.010) 1> 89.72 89.64 90.17 80.94 88.84 as. sa 89.11 89.92 89.79 89.62 89.S4 89.73 89.52 90.20 9Q.5S
lilT PJ..lT Im,-! - 10~/H1I,
H..~ J~p..:' r~aa r~el IDn1~ o..,,,,,~/&tt. (V/O ieJ"'" Lo..D 2138.7 2151.1 2C07.0 21S6.0 2226.0 2068.7 2107 . 5 2040.7 2037.9 2169.8 2222.5 1928.0 1912.3 199).5 2OO!t.7
@ (. j :;""oJ".., Ii&&~ 1n Pr.h...~811 .ur 198.5 191>.9 lS).l 21l.S 217.8 193.6 198.3 19S.1 200.1 204.6 218.2 173.1 173.6 176., 174.5
~ (.j ::'...lb1o n...~ 1n Puol 5.9 5.5 5.4 5.6 5.6 5.4 50S S.2 5.2 5.7 5.7 5.6 5.' 5.8 S.6
(-J I..oLon'. H..~ or Voporhat101D 91.2 91.3 82.5 91.9 9'7.9 91.0 89.4 87.0 86.9 95.4 97.8 82.2 8~.1 87.7 82.4
1(1 (-) CCEab~.Ublo H...~ Lo.. -ld ---!...J.. --U --..ai ~\.J. ---4J. -.l.l --...Jt. -.L.A --1A1 -L1I -J...a -W -.W.. ~f
tio\' Ii... ~ Input W.I>.l 2258.1 21l0.2 2200.3 2,~).4 217...6 2220.6 21S3.1> 21S4.7 2.<85.2 231.8.0 2023.) 2005.2 2OOS.S
-------
Boiler 0
~ l.6J71
'"Jon 9OQ096
~U= 1q1A.....u/L %aG.
F1al4 T04"t1l>6'.....s
Portor=o 1I..,.Uo
lUJNBT EFFBCmENCV ta\rNlD
U\IlET MEAT H\IJ LE> U if CA8..cc:tUJL~TD DIN) ~
msr 110. l.i U ~ U ~ .u z& u ~ J1 1i .u ]A 11
UIiU WTPIIT . IIJ,U 8IJ.AII:S IIITIfUO
1. r""':""ter n.o. ~~/tm 1648 1655 1587 1576 1660 1619 1708 17~ l.2J.:! 1158 12/,0 US6 U71 U9'
2. .1'\1 Pr........ PBl~ 2450 2~ 2)20 2)20 2720 2700 2790 2700 1650 1600 1 c;oo 1850 1950 11!7O
). FII Tep. at leon. , ~ 526 510 Sl2 '12 ~O 51' '16 1086 1086 1087 loBIo W 1083
10. InthalP7 at t,con. (). C) B1'II/UI sa 518 1099 501 501 1099 505 506 1071 1071 1072 1069 1066 1060
5. SUO Pr...~ PSlG 21.85 2250 2000 2005 2Iol0 .2420 21060 2520 1/025 1590 1650 1650 1625 1.650
6. :iI!O T"'P. , 1015 10)10 . 978 1010 919 956 960 96) 892 9ll 905 9210 9)) 9)1.
7. SIlO EnI.h4.lP7 G. S 1mJ/UI 1/078 lIo88 lIo6O lIo8O U05 lIo)l lIo)2 1/0)2 lIo27 110)2 1/026 11038 1IoU lIA5
9. inthalP1 DUt. 0 . ~ H 9610 970 961 979 9QI. 9)2 927 926 956 961 95/0 969 979 m
9. Total S!I AD.. tall~ 10~/HII 1588.7 1605.10 1525.1 15102.9 1500.6 1508.9 158).) 1621.10 .U87.10 1112.8 U83.0 11109.2 11.1,6.10 U67.,
10. SH SprAJ' nOlI 1o'UI/IJi 0 0 0 0 0 0 0 0 0 0 0 0 0 0
11. 51! 5prq Pr........ PSlG 2350 2.1.80 2220 2220 2620 2600 2690 2600 1"0 1700 lSOO 1750 1750 1770
12. 51! Sptv T""I'. r "5 ))6 32) )22 3(.]. )60 359 )6) 269 279 295 2910 290 )00
1). 51! I)pn.r Ilrt hall{ \ ~ B1'II /UI )10 )11 297 296 ))7 3)6 "5 3" 2/,0 251 268 267 26) 27)
a. inuuUP1 Ditt. - H 1168 1177 116) l18Io 1063 1.095 1097 109) llII7 1161 1158 1171 1182 1172
15. Total:;ll 5prq £1>0. 1 g 10~j\!n 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16. Col4 l1li Flow 1 LII/HIl 1250 1250 1270 l242., 1265 1192.5 1290 1)27.5 962., 885 9<0 c;oo . 892.5 910
17. Co14 i.W Proaaur. PSl~ 1015 Iol2 W Iol2 JI.XJ 10<0 1009 i>22 2'17 )00 )010 29) 29) 299 .....
14. Cal4 l1li Tep. r 628 6105 6U. 656 5)7 552 558 '51 5107 S/oO . 5)) 5109 "') m .0\
19. Col4 l1li ""tbalP7 0. @ H 1)21 1))1 1)29 1))'( 1267 1275 l280 1275 l2D4 1279 1276 1205 12910 l297 ....
20. 1!i'.II Pro. ouro PSlO 357 )62 )S) ) So:! )105 )30 )510 )79 2J,O 2;j) 255 250 245 250
21. iIHO Tcop. r 982 1008 964 98'; 872 912 912' 916 83/0 856 8106 962 882 690
22. .uii) u,thuP1 @ @ BtV/UI 1SlJ, 1527 15010 1518 1456 11071S 1/077 1/078 1loloO 11052 1I0.Io6 1455 110" lL69
2). kltM.1P1 D1rt~ ~ H .193 196 175 l4l 189 20) 197 2D) 156 17) 1'/0 170 171 172
210. Total All Aba. '" X 10~/Hi 2Iol.) 2105.0 222.) 2210.9 239.1 2102.1 2510.1 269.5 150.2 153.1 156.10 15).0 152.6 156.5
25. b.H Sprq now 1 /HIl 0 0 0 (. 0 0 0 0 0 0 0 0 0 0
26. .iiJI Sprq p,.'U81U'. PBlO 1500 1500 1500 1.soo 1500 1500 1500 1500 1500 1500 1500 1500 1500 1:00
27. IU! ~P""7 T""I>. r ,,) ))S )21 )20 359 )58 )57 )60 268 278 2910 29) ~ 2'17
28. RH 5pral !A~hali @ 0 BTII/LB )06 )08 2910 :m :m ))2 ))1 ')10 21..0 250 266 265 261 269
29. io>balP7 DUt. - ~ H l208 1219 l2lO 122!i 1123 UIo6 11106 u.u. 1200 l202 1180 1190 l2OIo 1200
)\I. Total l1li Sprq " 16 =/H!l 0 0 0 0 0 0 0 0 0 0 0 0 0 0
)1. T..al!lf Aboorbecl hl oller ~ . ~ . @ . ~ /HB. 18)0.0 1850.10 17107.10 1747.0 1739.7 1751.0 18)7.10 l89O.9 1))7.6 1265.9 1))9.,. 1)02.2 1299.0 1)210.0
unClUCI - li!.AT LOS.SiS II!:rHUD
Drr Cu 1.0.. ~ ).71 ).70 ).108 ).70 ).)8 ).)6 ).50 ,.108 ).06 2.90 2.7) ).01 ).00 2.90
1Io1.ture 1n I.1t 1.0.. ~ .09 .09 .08 .09 .08 .06 .00 .OS .07 .07 .07 .07 .07 .07
"1.t.u...~ tMra ~.l 1.0.. - 10.56 -4.55 10.60 ",II} 10.910 10." 10.56 10.55 10.69 10.61. 10.107 10.6) 10.6) 10.)10
Carbo.. H..t 1.0... - .06 .0It .07 .1.1 .710 .26 .21 .21 .65 .20 .28 .)5 .67 .43
Jl&d.iat.1«a 1..0.. - .2) .23 .24 .2.\ .24 .210 .2) .22 .)1 .)J .)1 .)2 .)2 .)1
M..; Loaa I.D r~ "ala ~ .05 .010 .06 .M .010 .05 .010 .010 .05 .05 .010 .05 .07 .05
Aab Pi t 1.0... ~ -a.D -a.D ~ ~ -a.D ---oll -a.D --& ~ ~ -..u -.6..1 ~ ~
Toul 1.0.... - 8.9) 8.92 9.83 9.)..?, 9.65 8.75 8.810 8.al 9.05 8.101 8.15 9.6a 8.911 0.)2
a.Joct T.cao ~ -LJ.1 .J...l.!l ~ --.d~. ~ .....1.J& J..Io!. -& ~ ....LI.b ~ ~ -cl! ~
Total 1.0.... (lad. a."oc\ Lou) ~ 10.)5 10.32 9.72 10.00. 10. 7 10.2) 10.25 9.75 10.10) 9.87 9.01 9.57 9.18
i!!1ch''''1 (11/0 a.J.ct 1.0..) ~ 91.07 91.08 91.17 90.83 90." 91.25 91.16 91.09 90.95 91.59 91.8' 91.)2 91.02 91.60
~t1chDC1 (II IlaJect 1.0..) ~ 89.65 89.68 90.28 90.00 89." 89.77 89.7' 90.25 89.57 90.1) 90.99 90.1,) 90.1.10 90.82
IiiT HUT LWPlJT . 10'sro/Ha
Heat la,..t tr.. Fual ~t Ou\~/ltt. (W/O a."..." I.o..il 2009.10 2031.6 1916.6 19105.2 1925.5 1914.9 2015.6 2075.9 1/070.7 1)82.1 1.1058.2 11026.0 11027 . 2 1U1o.2
D (.) s..n.lbl. Heat 1n Pr.heated A1r 188.6 19).' 170.2 178.9 167.8 166.5 177.0 185.6 llIo.5 ill.l 1110.) 1<0.5 U9.S 115.9
(.) s..nll1to.1. Moa> 1n Fuel 5.) 5.2 5.5 5.5 10.8 10.9 5.2 5.2 10.1 10.0 3.7 10.) ).1 ).6
(-) 1.6>- Weat at ~.por1..>1"" 85.7 86.6 810.) 85.6 6'/,0 al.1o 85.9 88.5 610.7 60.0 61.9 62.7 62.6 59.10
~ (-) C~,,"1.D1. llaat 1.0.. -L.i -U ~ --l.}. ...lA.a ---1.Jl -Aaa --...lI.o4 .:..J..i --3.Jl -A.l ~ -i.1 a~j
h. Hau lAp\4 2116.10 2lIo2.l 20101.7 19910.9 2(03.9 2107 . 7 2173.8 1515.0 1/0)10.6 1~0.2 lIo83.1 1/076.9
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Boiler ()
Contract 16357
Project 900095
- H,8 -
r0~bustion Engineering, lhe.
Fi~ld Testing & '
'Pe:rformance Resu1 ts
?At.~PLE' CAlCULATrmi OF 'E;:-qCIENCY - HEAT' lOSSE~. r.1ETHOD
TEST #1
1'.. DRY GAS LOSS, DGl,
DGL = (DP'L'Ig. AH}(.24)(TGL - TAE} X 10-4
, Where:, .24 = lristar.taneous Soecific Heat of. Dry Products,
T(;f: = Temperature of Gas L'lg. AH
.TN: = TelllDera ture of Air Ent. AH
Dp:Lyg; AH = Dry Products l'lg. AH
DEL = (956 ~ 52)( .24)( 265 - ,96) X 10-:4,.
DEL = 3: 88~~
Z.. MOISTURE'IN AIR LOSS~ ~lAL
MAL= (.013)(DA Lvg. I\H)(.46)(TGL,- TAi) X 10-4-
Where:: .013 =, St:lndard Speci fi'c .Humidity
.46: = Instantaneous SpecHie Heat. of \~ater- Vapor
DJ:..: Lvg. Ai-i
,.
Dc} i;i r" in truuuct5. L"Jg. Ai-{
MAL; =: ( .013 )(921. 58)( .46}( 265
~1AL =". 095~
96 r X 10-4
\~.. ~101ST(JRE- FRat., FUEl. LOSS; f.iFT ,
MFL=' MF[1089.: --TAE:.+-.46:'(TCi)-J> 10-4-. " "
, Where: fl1089 - TAc+h.46 .-(Tei)] JI.ccounts' ~or Evap~r~ting & ,
: Superheatlng the 001sture In
[- J' El From the fuel.
MFL = 41'.40 1089 ---96,'+- .46 '(265} X 10-4; ,
MFL = 4.62% - -
4... CARBON HEAT LOSS ~ C'-
Ct, =~
100% --% \:~~on in fly Ash [~ carb~~v :nf~~{ Ash (14 '!50~
Where:. 14,450 = HHV of Carbon
121.6: ,C' 1:4 (I.1,450) 'J"-
100_--1.4, 11160 '
-. .-
CL. =:-
CL= .277,
Sheet 84
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. - 169 -
Boiler 0
Contract 16357
Project 900096
5: RADIATION LOSS. RL
Combustion Engineering, Inc.
Field Testing &
Performance Results
Determined' From AB~~.CurveL
RL =:: .22%
6:: HEAr LOSS IN FL YASH, FAL.
%. ASH
~Al --
. - -- HHV
( .22) (T GL: - - - T AE-~
Where~: .22."==Specific Heat of Fly Ash'
llL6
F~L := 11160
FAL == .05%
.(.22)(265'- .96)'
i.. ASH. PIT' lOSS ~ APl .
Determined 'using :curves :on sheets. BS-1- 'an-d. B5:-2..~
. . Q) FiJrnace.: Wi dth, Feet -.-40 :167 - .
r.:::-..
\£I. Furnace cLJeptil ,Feet :-40.167 -
@. Furnace', Diagonal ~ Feet '-57:0
@. Furnace' He; ght; .Feet -:-1-14 ..83:
@.
@.
([).
@.
@ Curve:: Va 1 iJe : of-'Radiat to IT 'Tlfru' . Aperture ,.~ (%' Hea.t: loss) :: - .23
@ %.Ash"in"Fuel~ As::Ffred:-1-4..6.
@ HHV. Fue 1', as' Fi red. BTlJ/lB.:- .111"60::
.@~ @: (l04)/@. Ash Ffred/106BTtT -lJ.mr
~ % Ash Fi~ed.Go;ng.to Ashpit -0
@. Slagging.or Dry Ash Bottom? - -DrY Ash
@. Curve, ValueSens;ble and i..atent Heat of Ash (% Heat loss) -0
, .
h"?-.. - ,,-...
~ Total Ash' Pit ~lass :=i~}+ Q3i := =.2.1::+ 0 ~ :.~~%
DB tance:: n ring {.'_to- :Hopper: Ape:r:tur.e.',: Feet::; ':"49~ 66::
Rati6(]",G)-.81"
Ashpit- Aperture: (Area), .Feet~:- HYCL42. :
RatioC~-.015 :
Sheet 135
-------
- 170 -
~:s~ CC~~~L~T:C~.
~ -
:'1u.':tper)
p:... .rur:'~c'co-i.jicithO,~Fe~t. : .!... t..: .10A: . % A;~~"'i"r~'-?u'~i)-o'a's-'-:~re'c----- 0
!:2:,": :Furnnce Dept~, Feet. : . . ; .'''' ]:<7' '11.:' Httl 'l'\1e) I as Fired, 37U/# ,
'-3----Furna~c 'Di'-~o~a' - -reet-.' --l...--~12'-{-10}-.~'lG4l (11)" 'Sf. ~--d/10o'""
i- ~:. I '- I.J ::.e,:. ....., .~!:.. .1::. '.': h '. . ' i\ . l':,"-,:, . -'1 .)--
!- ~ .:.. .(Only ore CJ.. v:tded ftrr:.3.ce-) .:..... ';":':0'-:-:-:::-::-+3..;'... % As!"... ?ired. gO~.:1g tv ASl'.p:z. t,;u .
. '..~'t\Irnacc..r.ei;ht,.- ?ce.+ . . . .~.- -~-J..li-;-$lClg3~::!;.ci- - nC:'.F ash'L.oo:..tN.::? .
~5"..':-.Dist<\nce FirinE; 1: to..Hop'p'~r_'Apert}Ire',?;t-::.)5..: Cur:v~: VaJue Sensible & La~n~ HC~~;;j~~f~Pi~~:Fi ::~:.~f'~~~;~~ '..~~e;a ~~~_~;te_~~;p.~
:.~.-..
.......
. ..1. ...
. .':. .',' .
(::::-:1 :~~j~~~~~:-
ASE?IT : :-SA":'
(H.~.
.. .,. '0"" .
. . -.' . .
'-------.. .....-. t... '..".".
...-'.' ""'0 -. '0 .0
. -..,.--
.. . - . - . .
'"S'hect -i3s:r'
-------
f"
[
- 171 -
- - ...:..::=--....-...,
I,
'i.
i,
I " I I . , r 1 " I ,';';:'"i"~:-':7'!"'::
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.!. '".. I.. ;: 'r i.;' ;. " ',,,;,. ..':~;~,.~:::".,-",',:,'.,,'..,.. .:..:!, . i .~t ..: :, 'I
';.. "..''''''''''-'''' -', ' . I ! ; "0.:,' "-i'-~""~' '~'..
: " ,1. :~..!' " ~", ,', ','" I'" ::-i' ',..':':,', ~~h_,~-_--L:-5fice-t 85''':2--''
~~i>V,/~: ,
I:~.;~':, f-',
;';777~-'f .~'
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:" :1.:,::::' il.."; ,':1.
-".b~.'...' .. .0_"'"
.: :':J;,:.:::,'.:::::-:-:.i..
. "'.' .... .
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. :. :.' . ~
.. .. '.0 ...' ...
.. .. 0'
I':" r
-------
- 172 -
BoHe r 0
. Contract 16357
Program.900096
Co~bustion Engineering, Inc.
Field Testing &
Performance Results
8:.
REJECT LOSS, Rt
RL = LB/HR Rejected ( HHV, Rejects} X 102.
Total BTU/hR Input
~lhere : Tbtal . BTU/HR Input -i s :Estimated Using ~nit.
I
I
I .
5650 2
RL_= 3495 (2]51.7 X lOb) X 10
RL = .92%
I
I .
Absorptton .X.l .11J
Sheet 86
-------
'- 173 -
Boiler 0
Contract 16357
Praje.c.t. 900096
SAM'?[E CALCULATION OF HEI\T CREDITS"
ANO:LOSSES TO HEAT INPUT FROM FUEL
TESI -#1-'
CRED1TS.
1".. Sensible Heat In Preheated Air, HPA
HPA~ =. Hr Content-.Ai r @ AH Out Temp ~ [~A(,no\'l)
HP1\: = lOT (185~~3) ==198~5:X 10~B'nJ/HR
EnL. -. AH]~
2:.. Sensible: Heat- in Fuel ~ HF~
IfF == Co a r FT ow (. 3) ( Co a 1 ' Temp. - .80):
Where~
.3>=Mean "Spedffc :Hea.t '.of -Co:al
80: == Datam 'Temperature'
HF=196.,OOO~(.3)(181'--80) =:5~9.:X 106STU/HR
LOSSES'
L. latent Heat' of"Vapori zation, HV
HV ::-. MF (Heat', Input-,From Fuel) (1030)
Combustion Engineering, .Inc.
Field Testing &
Performance Results
Where~: l030:="BT(J/LB.~of'Hea:t .,to: :Vappr.ize:,~later.: in' Fuel~& Water.
Formed :by ~ Combusti.ori of tiydroge!1:
HV,=4-1".4-(ZJ38:1) (1030) ==9l:Z:X'106iTU/HR
2:'.. Cbmbustible:Heat'LOss. CHl
aiL = Cl. (Heat Input from Flien
CHL = .2T (2] 38. 7) =::5~8~X "lO~BTU/HR
Sheet ~i
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Boiler 0
:ONTRl\CT 16357
P20JECT 900096
~
V>
V>
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l..&-
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W.
- 1 71~
COMBUSTION ENGINEERING, INC.
FIELD. TESTING &
, PERfORr.1ANCE RESULTS.
EEFFCIENCY (\01/0 REJECT" lOSS)
VERSUS
r~AIN STEAH FLO\oJ (ADJUSTED)
92~O
_.. ; :.~i-;-~ ~~~~ -----...-..- --- -P~~f:~t:
" - --;--:.-~_. -~.~ . . .
~J- ' : --. -"-
! , I J i ' : ' : ;~- ': ,~ -~:- :-
I ; I " , .. .
. . +~~-~~ . . ' . [-'-i-i-- -,=.j . ~~ " '-': ~ =- '1 ~:
. I '-, ," ----:--j------,-----.----. ---
~:bU. -j- ;--+--EJr=-=-=F~~':~:~~tJ~
-~--t-".- _O----r---'''''- -~-[J----"'-"r ,- ..--.--1....---,-.-.
. ~-: ' -L~, :=:-:.~_: ' i_:~.=-~~~~~~=:- -~~~. 0.~~f _..~~~ =~~-0~:.~~~:1
91".5
9J.0 ~=it:-- -~;t::~= .:=r:~~-f=~~2=~ft:~
-'-'~ '~- ~~=-=-~"....: -'2;,.,--1-8'-'- -.-,- - =sI
=t-: . r ' : -~~'. .--.,:: ~ ,-~==~-!=-Q+--~~~=-~: =~~~~=:~
90:5 -. ", . ----j--- i _1__- -----1.. -..-:.--.
=_: . : ~~-- ::~=:.~. ::. -T~~=':~- : =~I-~ ; : ~~~~~~~~-; .,-
90;0.='- ~~-~'~,~= '£e=::; == =f:~,: :~~~:~~~L~~-5~
3000 3lO0 32.0.0: 3300 3400 350.Q:
MAIN STEAW FlO\I (AD.JUSTED) - 103LB/HR
0-.5 Mills In' Service
0--4 11;l1s In Service
Dashed line. is Average Effi-ciency
(W/O Reject Loss) As Determined
For Performance Tests, Aug., 1962.
Sheet 68
-------
Boiler 0
C"""ract. 1.6)57
Pro jec' 9QOC)96
~.uo.. ~r1A4. 1zIc.
F1eld Tollt.1II11 aDd
Port........co !I.ooal\8
~UMMA~V ~0t~ T~~tr ~Atr~
,.,m
T~'T 10. l .i 1 . j i Z J 2 12 II M 1.1 U. 11
Date 1./15/71 I./15/n I./15/n 1t/l5/n 4/l5/n 4116/71 4/l6/n 411.6/71 1t/l6/71 I./17/n It/17/n It/2l/n It/2l/n 1./20/71 I./ZJ/.11
aroaa Loa4 III 1,60 1+70 It60 1,75 1,75 1,60 1,65 1,55 1,55 1,80 1,80 /UO 1,)0 447 I,SO
7LUaS - lo"Le/Ka
11&111 &..-. (lah«.) )25).8 )207.) )057.0 ))26.1, )1005.1, )21,).1 )187 . 7 )16).8 )120.0 3381.) ))60.0 )4)6.1, )1.10.5 )509.) 310'/8.8
IIUn St..... (MJuahd) )280.) )197.7 )102.9 ))7).0 )))2.1, ))08.0 )187 . 7 )195.1, )1)5.6 )101.8.9 ))4).2 )109.9 )069.5 )21,6.1 )2)6.1,
aob""t St.oaa (Grapl» 2555 21,90 21,20 261.0 2585 2570 21,85 2485 21,1, 5 2660 2595 21,2 5 21+00 2525' 251.5
!jet, ProdIlC 'a liet.. !II - B 2018.5 2004.0 1867.1 2lJ.l.1 2191.1 19S1o.7 196).) 20)2.1 206l.7 2137 . 5 221).) 1796.) l802. 5 18)5.2 1802.2
Dry Proc1uc'" let.. 111 - B 1906.2 1891.7 1765.0 2026... 2070.2 181,)." 185).) 192).6 1952.9 2019.6 2092.) 1695.) 1699.8 1728.6 1701.2
Wet .I.1r Ent.. 411 - B 1855.) 181oD.) 17U.O 1976.2 2017.0 1792.9 1.B02.8 1876.0 1905.8 1967.8 20)9./0 1648.8 1(5).0 1679.) 161.6.) I
D..,. .I.1r liet. 111 - B 18)1." 1816.6 1688.9 1950.7 1'.90.9 1770.0 1779.6 1851..9 1881.1, 1942.6 201).2 1627.6 16)1.8 16~7.8 1625.2
Wot. Prod\IC,," L~I' 111 - B 21.59.9 2lI,1,.2 1997.8 2291.0 2)1.4.10 2091.7 2100.8 217/0.1, 2201>.0 2287.2 2369.2 1922.0 1928.7 196).6 1926.5 I-'
Dry Prod~ch LVI. !II - B 201,5.7 20)0.2 1894.0 2174.) 222l. 5 1978.5 1989.1 2064.0 2095./0 2167.1. 2245.) 1819.5 1821+.) 1855.4 1825.7 --..J
lio' Air LVI. 411 - B 1996.5 1980.5 leu.6 2126.0 2170./. 1929.9 19J.O.2 2018.) 2050.1 2117.5 2194.4 1771,.5 1779.2 l1!Ul.7 1772.1, \./1
Dry .I.1r LVI. AI! - B 1970.8 1954.9 1817.9 2098.7 2l.42:' 1905.1 1915.) 1992.) 202).8 2090.2 2166.1 1751.8 1756.10 1781,.6 1749.7
~IIE - P3l0
lat St.aS' 1562 15)5 1.521, 1599 1581 15SO 1.S1,.2 1518 JJ.91 161.1 1607 11,78 lJ.68 15)1, 1 SJ.8
lot. 9I.&go <.Acljuat.8d) 1559 1529 1.5)8 157) 156/0 1.55) 151,5 15)8. lS210 1580 1575 151.9 151.5 lS106 1553
TLX?lliATU!!LS - 'r
SII Outlot - B lO37 1056 . 1032 1.030 10!,6 1015 1.060 lO29 1037 101.9 lO6I, lou. 101.9 992 101.8
BIJ Oullot - B 1021, m lOCO 1018 lOU 986 lq1) 1000 995 991 1016 969 986 968 1000
I>Ii Oullot - A 1017 1019 10)) 1064 1062 1031 101.6 1(5) 105) 104l 1~ 10]0 10)2 1016 1054
BIJ OuUot. - A 985 998 1000 1025 1001. 989 1.019 101) lOll 1004 1.01) 985 'rX) 980 1020
BIJ 11llot - B 598 SIo2 585 60S 59J 60S 600 619 598 608 60) 642 61,5 621, 6SO
icoa. lA. - B 522 516 515 526 S22 S2l S2) 518 517 518 529 520 520 SU 518
C... i:a\or1JlS All - C/O 610/6)2 61.2/6)2 6lIt/6)1 61 5/6)2 617/6)1, 1/)9/623 ~)/6)O 6.12/627 6.12/626 61.7/6)) 62J.j 6d,O 602/61.1 (J;):1j610 6010/61) bOl/fj;)5
/Q OCJ::i.UJlWJS
O:z-B . 2.62 2.68 2.89 ).59 ).)6 2.55 2..64 . ).64 ).95 ).)8 ).58 2.)2 2:SO 2.01. 2.19
. 1xc 0" .I.1r - B . 1).9 11,.) 15.7 20.2 18.6 13.5 14.2 20.5 22.6 18.8 20.1. l2.1 1).2 10.) U.I,
CWJ, ~
COAl Fl.- - A = 192.) 178.6 177.6 l82.2 1.86.8 185.6 188.4 180.0 177.9 1.98.2 190.1 181.) 1.67.6 1.87.8 1.9,.0
B 196.0 187.1, 186.8 l89.0 195.5 .194.1. 197.6 189.8 181,.5 198.9 200.7 182.8 171,.8 198.8 195.7
C6al to PI&n>&c. - A . 1,9.5 1,8.8 J.8.7 1,9.1 1,8.9 J.8.9 J.8.8 1,8.7 1,9.1 1,9.9 J.8.7 49.8 1.9.0 108.6 1,9.3
B . SO. 5 51.2 51.) SO.9 51.1. 51.1 51.2 51.) 50.9 50.1 51.) 50.2 51.0 51..1, 50.2
IIW Per hnIac. - A J 227.7 229.4 22J..0 2)).2 2)2.) 221,.9 226.9 221.6 223.1, 2)9.5 2)).8 2lJ..1 210.7 21.7.2 22It.1
B J 2)2.) 2J.O.6 2)6.0 2.101.8 21,2.7 235.1 2)8.1 2)).4 2)1.6 :zr.o. 5 21+6.2 215.9 219.) 229.8 225.9
I I!lU. 1U.:l!t't S - LBNA
eo M~. lleJect. now - It 31095 ),95 3It95 5625 5625 5625 562S )495 3It95 )615 )t.l5 loWS 1,905 )615 )61.5
...
-------
Boiler 0
eaar..., ~ST
ProP=' 9CIC096
Ca:ba..uoz>~. lDo.
11al.4 T...U."4 <=1
Porf"""",,,o ioc:o.Uo
SUMMA~Y ~dJF TE~T DATA
nsr 110. U 12 11 U i2 .2l .ii 21 .12 .11 J3. 13. JA 11
0.\.8 It/n/71 1t/21/7l 1t/20/n 4!2O/n 1t/22/7l 1t/22/n 1t/22/71 It/Z2/n 4/19/7l 1t/19/n 1t/19/71 1t/19/n 4/19/7l 1t/19/7l
aro.. Loa4 tDI W 1055 J,I,O IJ8 1,20 J,lB 1.37 4l>5 300 JOO 310 310 J05 310
lWiS - lo3t.a/KII
IIA.la Ste.. (Inte«.) 3360.0 3329.2 31,93.1 3482.2 3067.8 2929.2 3150.0 3229.5 JOBO.o 2?OO.0 2741.1 2710.6 2717.2 27~.9 ......
J:l.t.1lI Ste.... (AdJu.ted) 3208.8 3212.8 3266.0 3186.2 3251.9 3061.0 332).3 3439.1, 2l.79.4 2281.5 2371.1 :(317.6 2296.0 2)103.1,
a.heAt Staaa (Greph). 2500 2500 2540 21,8 5 2530 2)85 , 2580 2655 1925 1770 1840 1000 1785 1820 '-J
\lot Products Eat. AI! - B 1949.5 2<»'5.8 1770.9 1839.6 1825.4 1778.1 1872.9 191.3.0 1345.4 l288.1 1313.8 1367.1 1338.1 12<}4.9 0'1
I>r7 Products Eat. All - B 181.3.2 1Wl.9 1668.2 1734.9 1117.1, 1677.9 1767.5 18J4.1 1266.9 1213.9 1238.3 1290.1 1261.6 l222.1
"'ot J.1r Ult. AIi - B 1795.8 1860.5 1620.9 1687 . 5 1678.3 1632.0 1718.9 1781..1, 1231.0 1180.0 J..2O:l.9 12~5. 7 122~.1 1182.8
Dr1 J.1r "'Eo.t. AH - B 1772.9 1836.6 1600.2 1665.7 1656.7 1611.1 1696.9 1761.6 1215.1 1165.0 liB7.Io 1239.6 1209.1, 467.6
\let Products 1.1'«. All - B 2086.0 n56.9 1894.8 1968.3 1953.2 1902.4 200J. 9 2079.0 11,39.5 1378.2 l4D5. 9 ll.b2. 8 11031.8 1385.6
0"1 Produch Lv«.. All - B 1978.1 2047.2 1790.7 1861.9 181.3. 5 1000.9 1896.9 1968.4 1359.8 1302.9 1329.0 1384. ~ 135J..1 13U.6
\let 11.. l.1'g. AH - Ii 1932.2 ' 2001.5 174J..9 1816.2 180~.9 17~6.1, 1850.1 1920.1, 1325.1 l27O.3 l294.9 1351.10 1)18.9 1273.5
I>r7 Air l.1'g. AH - B 1907.5 1975.9 1722.4 17?2.9 . 1782.8 1733.9 l826.3 1895.7 1300.0 1254.0 1278.3 1334.0 1)01.9 1:/57.0
~RE - PSlG
let StAge 1526 15)1, 1511 1515, 1435 1391 11,94 15ll 1091, 10)7 110) 1071 1063 1003
let Sug. (AdJ""hd) 1SJ,l 1545 1~38 1536 1507 lJ,81 1530 1559 1335 l296 1329 1317 1310 1327
~TUI!!'.S - .,
611 o..tlet - B 1~5 1034 978 1010 919 956 960 963 892 911 '105 924 9J3 .9310
!III o...tlet - 8 982 1008 961. 989 872 912 912 916 8JI, 856 8/,6 86.2 8SZ 890
611 o...tlet - A 1042 1061 1044 1053 968 990 9S4 9!)2 911, 9J3 916 9I0Io 9~ m
!III 0ut.1et - A 991, i018 1002 1022 £94 '936 919 920 853 U:l S49 870 907 918
RIt Inlet - 8 676 64l 639 64J, 536 553 559 566 5105 SIo2 532 5J.9 5~6 562
Ee"". In. - 8 52) 526 510 512 512 510 515 516 1,86 1oB6 487 1084 W 48J
Ca. Eahr1n& AH - C!D 608/61.6 61.3/620 598/607 607/61) 588/591 'JIJ9/m 599/607 599/607 545/553 5109/554 551/558 549/5~9 54t/5~ 551/559
IUSCKI..!.tJiWUS
02 - B J 3.14 3.~ 2.08 2.57 2.36 2.~ 2.29 2.1,1, 1.96 2.28 2.00 2.88 2.27 2.18
KiA: 0.. J.1r J 17.2 20.1' 10.7 13.6 12.3 13.7 12.0 12.8 10.1 11.9 10.3 15.5 11.8 n.Io
CO.l1, !CALES
Coal Flow - A ~S/KII l82.1 182.2 180.0 191.1 1n.7 .168.0 180.0 1n.1, 152.3 137.1 144.5 138.5 138.~ 148.8
B LBS/IIR 181.7 179.7 186.5 186.1 166.5 165.2 1710.3 1 '/8.1, 151.9 152.6 153.1 148.6 133.9 LU.5
Coal To ~. - 4 J 50.1 50.10 1,9.1 50.7 SO.8 50.1, 50.8 109.0 50.1 1,7.3 48.6 48.2 50.8 51.3
B J 1,9.9 1,9.6 50.9 1,9.3 49.2 49.6 49.2 51.0 1,9.9 52.7 51.4 51.8 1,9.2 1oE. 7
III 1'... '.......c. - A " 22J. ~9 229.3 216.0 222.1 213.1, 210.7 222.0, 227.9 150.3 141.9 150.7 149.4 154.9 1~9.0
B ;. 22J..1 225.7 22l..0 215.9 206.6 207.3 215.0 237.1 149.7 158.1 159.3 160.6 150.1 151.0
~ JW.I. RiJECTS - L9/p.R
'" 1'1&11'. lieJect now - 8 1,'105 1,905 361.5 3615 31,95 4905 4905 3495 291,0 2940 l8I,5 181.5 1815 1815
....
0
-------
'.
Boile r 0
Contract 16357
Prolect 900096
3000
2800
I
I .
2600
'.
. . ' .
~. 2400
---
Jtt
~
0.
,.... 2200
><
:x
~
a.. 2000'
H
CI1
5
~. 1800
1600
1400
1200
. ~.'
,,' '...
. .
,.
r . "
177 ;,.'
Combustion Engineering,
Fi~ld.Tcst1n~ and
Performance Result£
Inc.
'. ,
. "
.'.
1U:RE.:\T STE.. ~1 FLOH .
VERSUS
HAl~r STE~! FLm;
~;=:~~=r~~m~.~~l~i~t~]
~ - ~;~~~~~~i~~~~~~~~
~~~~~~~~~~~i;E~~it~t~~~
~'~~_._-~~-=:~~~~~=x!~~~t:~~;;~~~~~
---==--==.-::::.::::.--==--==.. ::.-:.:===- ~-::=::'1 :'::':--=--:='::/."~-=::" -:=-:~ -=--= =-.~. :::: :-~
~~~=~~~~?~~~~~~~~
'ii~le.=ti~=
~~:_~~~~~~~~{ji1~~~~~~~~:~I;~~~~
~~:~~~~~~~~~~~~S~~iit~~~4~k:~~~,~t~[~r:i
f~~. '~~~~~~~~~~1t~;:;ii~~~t~~{~;~~;[~'~:=0~=:~~tif!J~~~.~
;~~~~~~~~~~~~~~~~}~~!~i~mYJf~i~~ REHEAT STOOl FLOW ~
. =
CALCULATED USING
PERF0R}lANCr; TEST
DATA, AUG. 1962.
-
-
-
1000
2000
3000 3500
XI03tB/HR
4000
4500
1500
2500
M.U~ STE~ .Fum
Sheet B11
-------
i
I
Bo i1 (' r 0
CONTRACT 16357
PROJECT 900096
(!)
......
V).
C1..
-
CI
UJ.
t-
V)
:::J
....,
o
~
-
ILl
0::
:::J
V)
V)
I.LJ
0::
~
LLJ
(!)
ex:
t-
V)
t-
V>
0:::.
.......
L1-
I
-~..o
- 118 -
COMBUSTION ENGINEERING,
FIELD TESTING &
PERFORMANCE RESULTS
INC.
MAINsrEA11 FLO',oJ (flDJUSTED)
VE RSUS
FIRST-STAGE PRESSURE (ADJUSTED)
2200 2400 2600 2800 3000 3200 3400 3600
MAIN. STEAM FLOW (ADJUSTED)
- 103LB/HR
Sheet 812
-------
. .
- 179 -
'RoUP. r 0
Contract 16357
Project 900096
SN~PlErALCUlATION OF GAS & AIR FLOWS
TEST "1
"I. ULTH1ATE COAL ANALYSIS -
Carbon -.61.3%
Hydrogen-- 4.3%
NHrogen-- 1.5%
Oxygen - - 7 :1%
,Sulfur -- 3:7%
Moisture-:- 7:5%
Ash - -14.6%
TOTAl.l00:0%
HHV- = :1",160' BTlf/LB.
2. TREORETICAL DRY AI-Ri TDA
TDA-=li1:54-(%'C)- +'34.,34 (% H - ¥r-+ 4.32-0~ S)J.x 104
~ HHV X 10~ '
Wher.e: 11 :54-= oLBS. ~Ai r to': Burn One lb~ C
34~34.= -lBS_~i,r to'- Burn One Lb. H
4:32 :=,'LBS.:Afr to' Bu'rn One- Lb. S
TDA-=l-'1.54'(6L3) +34.34 (4.3 - i;-+ 4.32.'(3.7)1 X 104 '
- L- 11.,160 X lOb . j
TDA~==753~20 LBl106B1:lJ'
.. :3:; MOISTURFIN AIR,. ,MA
MA:'== .013 (TDA)-
Where: .OT3:= oStandard'Spec;fit. Humidity~
MA:'==.013:(753~20l = '9]~rlBJ_106BT.lf
.~~" THEORETICAL WET"'AlR; TWA
"fWA-=:TDA +-MA
T~A-=:753.20 + 9:7g.'= '762.~99: LB/l06BIU-
!5~ FUEL IN PRODUCTS, F
I
F:=: J10~HV -~ f~g - % scq -
Where: % SCl_= ,CL_(HHV" Fue.1/14',450)' ,
---- (100'--14.6--- .2)'
F---. 11,160 X lOb
- X 104~ 76:34 LBL106BTU
Combustion 'Engineering, Inc.
Field Testing &
Performance Results
SheGt B13
-------
Redler 0
Contract 16357
Project 900096
. - 180 -
6:.. 1101STURr FRor.' FUEL. I"F
MF =-
(% Moisture) +.9 (% H)
HHV X lOb
X 104
Wh~re.:. 9 = LB 1'10i sture: Formed by Bur.ning .1 19- Hydrogen:
~1F=jT.5) + 9 (4.3)
11 ,160 X 1 Db
7.. GAS. FlOHS. ENTERING AIRHEATER AT.13"9~; EXCESS AIR
X 104-=c4L40:LB/l06B.TU
A~. - Dry Air. DA
~- %. E- A' J
DA. = 1 + x~~~s 1r i (TDA) (K)
. ~
Where: K = 1 _. (% SC(/100)
ITA {r + ~ ~o 9 J 753.20) (: 998) = ,856 :171811 06STU
Ok (Flow). =.DA (Heat Inollt-From Ftip.l)
UA (Rm'J) = 856.17 (2138:7) = "183L4.-X 10~LB/HR
K.. Moisture. In Air. MA
.. MA. = .013.": (DA)
~~ = .0]3~ (856:17) =~11:13:LBll0~BTU
c. Wet. Air,. \-fA
WA =- DA +. MA.
HA. = 856: 1 T +-11: 13: = ==867 :30 :LB/1 O~BTlJ
WA (Flm'/) = ~IA (Heat:Input:From.Fu-el)
~JA~ (Flow) = 867.;30 (2138:7) =:.1855:3:X 103 -LB/HR.
D~ Wet Products. WP
WP: = F +. WA
w~= 76.34 +.867:30:=-943:64.LS/l06BTU
Wp: (Flow) =owr: (Heat Input-.From Fuel)
~W (Flow) =.943~64-(2138.7) =02018.5 X 103 tB/HR
Combustion Engineering. Inc.
Field Testing &
Performance Res~lts
-Sheet 1314
-------
- 181 -.
Combustion Engineering, inc.
Field Testinq &
Performance Results
Boile r 0
Contract 16357
Project 900096
E~ 'Dry Products, DP
op:= WP -.MA - MF
DP = ~~3.64.--11:13 - -41-.40 = 891.~ lllB/106BTU
DP (Flow) = JP (Heat Input From Fuel)
OP~ (Flow) ==891:11 (2138.7) = 1906.2 X 103LB/HR
8~ GAS: FlOHS'LEAVING'AIRHEATER AT'2Z.6 % EXCESS AIR
,A~ D~v Air; DA" .
OA-=: [1'+,% ExceSS'Air]'(TDA} (K)
100
01\:== C'+-22:6:]"(7SJ:20H.99a) = :92T."S8:LB/l06BTU
100, .
, .
01\ (FTm'l) ="DA-(Heat' Input .From Flie.l.) ,
, DA (Flow) ==-921 :58 :(2138.'7} = ,197U.8, X 103 'LB/HR
,I ,
B~, Moisture:in Air,' MA:,
MA =,.. 013 . ( DA)
MA:== .013:: (92l:58} = ,,11 :,9.8 'LBJlO~Ttr
C:. Wet~Air; WA"
WA =::DA +-MA
WA ='"-921: 58 +.:..11:98:= =933~'56:'lBJ1cfiT1f
\{A, (flow) ="WA~(Heat :Input '.From Fue.1:)'
WA (FTow) ==933:56 (2T.38.:7,} = ::19'9:6.5,)( 103LB/HR'
0:. Wet~Products. WP_-
WP =: F:+-WA
WP =:76~34 +-933:56:=:-1009:90'1Bf-106BTU'
WP'(Flow) =~WP (Heat'Input From Fuel)'
WP (Flow) =:-1009.90 (2"38.7) = ,2159:.9 X 103LB/HR.
. .
Sheet 1315
-------
- 182 - .
Co~bustion Engineering, Inc.
, Field Testing &
. Pefformance Results
Boiler 0
Contract 16357
p'roj ec t 900096
E~, Drv Products, OP
OP' =~Wp:--MA---MF
DP', =0 1009.90 - - 1 L 98 - -4 L 40 = 956'.52" LBI1 06STLr
Dr (F1riw) =.OP (Heat Input Ffom Fuel)
Dp: (Flovl) ==956;52.(2138:7) = '20.45~7 "X103LB/HR
Sheet,B16
-------
Bo i1 e r 0 Co:abu8t1on !na1n..rlnl, Inc.
Field Test,inl and
Cocr\r..,\ 16)57 Pcrrtcrman:. ReoU.1t8
ProJoc\ 900096
~(QLt~~~ ~~D [;:~fIViHJ2) UT ~ ~ D~uA
nsr 10. 10. i 1 .. .i A I II i 12
0.\8 1o/l5/71 1o/l5/71 1o/l5/71 1o/l5/71 4/1 stll 1o/l6/7l 4/16/n 4/16/71 4/16/n 1o/l7/n
lie.. Loe4 - III 460 470 /J,O 475 475 /J,O 465 455 455 1080
FLLNS - lo'LslIUt
KA1n su... (Int.C.) )25).8 )207.' )057.0 );26.- )315.8 )21.).1 )187.7 )163.8 )120.0 )381.)
KA1n 5\- A/B 169O/16SO 168WJ.62O 161.O/1blO 1720/1600 1no/1680 1600/1620 1660/1620 161.0/1600 1620/1590 17SO/1700
Main Ste.u. Total )400 1370 llO 3470 J/.2O 33SO 33SO JJOO J280 J500
Air Flo;' A/B 1620/1580 1580/1560 1590 5SO 1710/;.700 1no/1680 1670/1500 l5SO/15OO 1670/1620 1670/1620 1790/1710
A.1r '10... Tot.&l )220 )200 JlSO ;500 J500 )200 )200 J300 J300 J500
r..4wat.8r (Int...-) )/,,46.5 )417.9 )21.8.9 JS:!8.0 . JSil.7 )1.20.0 JJ89. 7 JJJS.8 )J07. 5 3561..9
'eedwat.cr Total J500 J4S0 J400 :JS2O 3520 J/.SO J400 JJSO 3300 J525
SH m.SH 51"'.J 8 I.5/IIS % 4/17.5 ~O % % % % % % %
I!!I D£511 Spr., 8 I.5/IIS % 0/27 010 0/0 0/14.5 % 0/10 % 0/8 %
1)4 Heater Dra.1n JOO 290 290 JI0 JOS JOO JOO 290 285 JOO
IJb Huter Drun )25 )25 )25 )35 ))0 335 J2S J25 J20 )25
SH D'-'JI! Sp'.' 1 LS/RS % % % % % % % % % %
IiH D<.:;cI Spr., 1 LS/IIS % % % % % % 0/2 % % 0/0.
lnJ. ..ter lAakott 52 52 52 :.;: 52 51 Sl 51 51 52
InJ. W4t.er 82 82 80 8J 82 81 78 80 79 85
Soot. ltlow1n1 Sta. (In\OC.) 1654/1594 lS09/146J 1567/1546 1494/1533 1612/1626
-c.a. now A/B 1492/1 S2I. 1528/1490 l.I,U/lJ. 74 1629/:.604 198J/1512
l'\U.SSUaLS - PSI0
Dna 2SSO 25SO 25SO 2570 2570 25SO 25SO 25SO 2550 25SO
SII Du'a' A/B 24SO/2I.SO 24SO/2I.SO 24SO/2I.SO 24S012l.SO 24SO/2I.SO 24SO/2I.4O 21.50/24 SO 2450/2440 24SO/2I.4O 21. SO/24 SO
I!!I o.a.l... A/B )80/)67 )80/)70 )72/)62 )W/J78 )'12/)00 )77/)65 m/)65 J68/JS5 365/J so 38S/J75
Ka.1n St... 2400 21.00 2400 2 t,2O 2420 21.00 2400 2400 2400 2400
'oCld...aUr 27SO 27SO 27 SO 2700 2780 27SO 27SO 27SO 27W 2800
8H lnl.' A/B I/JS/II)2 II) 5/1,02 )98/392 418/412 418/412 401/)97 W2/)98 )94/J9O )82/Joo 417/410
I'!!6:>SUI!i.S - lB. H,!C) ~
CO
Purnac. A/B -0.70/-0. SO -0.70/-0. SO -0.70/-< .70 -o.6O/...;).ioS -0.60/-0.48 -0.65/-0.52 -0.75/-<),52 -0.62/-0.40 -o.S5/-o./IJ -o.70/-o./IJ I.,..)
K1ch T""I>' SIt DIrt. A/B 0.90/0.85 0.90/0.90 0.90/0.90 1.2/1.2 ' 1.~.0 0.75/0.80 0.75/0.90 0.80/0.90 0.80/0.90 0.80/1.0
IUI DHt. A/B 0.12/0.10 0.1)/0.10 0.13/0.10 0.161').12 0.15 0.11 0.14/0.09 O.IJ/u.07 0.14/0.10 0.14/0.10 0.18/0.18
4>" Tap. SII DHt. A/B 2.7/2.) 2.7/2.2 2.7/2.2 ).::,'2.5 ).2/2.4 2.8/2.2 2.~2.2 ).0/2.) 2.8/2.J J.2/2.5
ken. our. A/B 0.95/1.] 0.95/1.] 0.95/1.25 l.l/l.4 1.1/1.)5 1.0/1.2 0.95 1.25 1.0/1.] 1.0/1.) 1.1S/l./IJ
All DHt. A/B 2.8/1.8 2.7/2.0 2.7/2.0 ).0/2.4 ).0/2.) 2.6/2.2 2.7/2.J 2.7/2.2 2.7/2.2 ].:>/2.5
c/O 2.5/].5 2.6/J.5 2.7/).6 ].0/4.0 2.8/3.8 2.6/).5 2.5/3.5 2. 7/J. 7 2.7/J.7 2.5/4.0
Cire. Pu.op DHt. (P:II.I) 24 25 25 24 24 25 25 25 25 25
FD F... Dbcb. A/B 5.2/5.8 5.2/5.5 5.2/5.5 6.0/6.0 6.0/6.0 P/5.5 5.0/5.5 502/6.2 5.2/6.2 6.0/6.0
c/O 6.5/7.0 6. S/7.0 6.2/7.0 6.8/7.2 6.8/7.2 6.2/7.0 6.0/6.5 7.0/7.2 6.8/7.5 7.)/8.0
IJ.r l.e&'I1.oc All 1-8 ).2 2.9 2.9 ).2 ).2 ).0 2.7 ].2 J.O 3.5
C-D ).7 ).7 ].5 4.0 4.0 ).6 ).) 4.0 J.8 4.5
111~ 1 as/!.S 2.)/2.7 2.)/2.) 2.2/2.) 2.5.'2~ 7 2.7/2.9 2.)/2.5 2.2/2.J 2.4/2.7 2.5/2.7 2.7/3.0
li1ndbox a RS/LS 2.7/2.5 2.7/2.4 2.]/2.) 2.7/2.5 2''}{2.7 2.}{2.] 2'X2.0 2.8/2.8 2.8/2.8 ].J/3.)
11) F... lnla' 1/8 10.7/9.8 10'X9.4 lO'W.5 12.0/ U.O 12.0 11.0 10.8 10.2 10.6 10.0 U.0/1O.2 U.0/10.~ 12.5/11.5
C/O 9.7/10.5 9.5 0.2 9.5 0.2 10. 5hO. 5 10.5/11.2 9.0/10.0 9.2/10.0 10.0/10.5 9.7/10.5 10.5/11.5
T!.I\PWA1\JP.I.S - 'F
SIt DuU., A a/L 960/1035 995/10SO 1000/105] 1015/,070 1025/1080 99 5/1050 1000/1055 1005/1065 1010/1070 1010/1065
11/1 DuU.' 1 P./L 9SX980 97X990 98iJ/990 995ll00S 97X995 955/975 985/1000 97X994 950/1005 980/1000
SII DuUo' a a/L 1012 050 1025 070 1015/1045 lOO5/.\OJO 1022 10SO 1000/1020 10) 5/1065 1005 1030 i02O/1045 1010/1020
IUI uuUo\ 8 P./L 980/10)0 965/10)0 970/1010 981J,' iOOS 980/1012 970/97 5 990/100 5 975/m 990/990 900/930
SII DuU... A 1010 1020 10)8 L055 1060 1025 10JO 1045 10SO 1040
iiH DuU... A 980 995 1010 .1015 1000 980 1000' 1000 1000 1010
SIt w.l'" a 1 OIIJ 1055 10)8 1025 1047 1015 1055 1026 1011J 1025
IUI WU.. 8 1025 1055 1010 101) iOl0 980 1010 995 m 995
Icoc. L1J1k 10b0o A/B -/- -/- -/- -../-- -/-- 620/620 625/630 625/625 625/625 625/~3O
ea. !.o4I.lAc All Ala 295/255 290/272 290/270 29,/290 )00/2'/) 292/288 293/288 )00/265 )02/267 29 5/290
c/O 266/26) 266/265 268/266 27\/275 278/280 27 5/275 279/200 260/259 261./262 265/260
IJ.r En'.rlAc ..~ A/B 92/95 96/99 100/10] 10)/107 105/108 10J/106 106/109 97/98 100/102 W/95
c/~ 97/95 1~98 105/102 10111105 ilO/l07 10'1/105 ilo/l07 98/100 10J/loo 61 iJlJ;
0Gu I.nUrl.n8 AH A/B 601/612 60 614 603/61) bl; 1625 615/627 6O)/6l4 6OS/615 IIJ6/bJ,6 1li>/617
. c/O bl4/ 620 618/626 61J/bl7 61', /622 62J/627 6l2/blJ 619/621 616/bJ,4 617/617 621 /621
-Sit Pl.t.en Outlet Heir. A/8 78)/778 779/799 797/7W 787/7710 796/787 787/779 7'IJ/794 799/774 793/775 792/778
"1Ior. SIt v.;U'" Hdr. A/B 907/911 916/939 929/917 952/919 962/937 '126/90] 93~932 942h914 942/932 947/918
-Sit Outl.t. &11-. 10SS/l04l 1059/1059 1077/1066 1101/1065 1106/1090 1069/1042 1079 1087 1091 1050 1076/1061. 1088/1058
- DuU.. Hdr. A/B 1012/1050 1024/1037 10J9/1040 1054 {l04'/ 1037/1049 1009/1016 1036/1045 102'//102'/ 1033/10)1. 10)1./1030
8.ur LMY1n.g IJI A/8 540/515 540/5)0 5)9/m 54: 1542 548/546 SIoO/535 5103/5J6 548/51 5 548/)17 5W540
0 c/O 510/5JO 514/535 Sl]/SJl Sli/536 521/541 519/5310 526/542 ';[;4/522 507/526 5{,9i526
~ 8$ Spra.,y Water B )54 J55 ]55 )56 . 354 35] )48 348 J47 J63
-wi Spr&7 Wat.er B )51 J53 J53 ]54 352 350 )105 346 344 360
.~ -t.;,; ':-:J-!~,.:
-------
Boiler 0
c:.-u-" 16351
Pro Joe\ 900096
C_Uon !ng1r....r1nC. 1nc.
Field tl).rtln& U14
Perta"'Jal1C8 auu.lt..
~DA~D A tNH"Q) CIp~~UTER DAirA
n:sr 10. .. i 1 ~ 1 i Z. a i J,Q,
0&\8 4/15/11 4/15/11 4/15/11 4/15111 10/15/11 4/16/11 10/16/11 I,/l6/11 10/16/11 10/17/11
Oro.. Load ~ II!I 1,60 1,70 1,60 1,75 1,75 1,60 1,65 1,55 1,55 1,80
~
IIUl Aap8 Al/ A2 0/58 0/56 0/61. 5/./510 5)/56 5/./51. 55/510 0/58 0/58 55/55
JJ/1.4 52/5) 5)/5) 5)/% SO/SO 52/52 so/so 51/51 54/54 51/ Po SO/52
A5/111 srI~ 51.).0 54 52/62 510/6) 52/61. 52/65 Sb/O 5100 SO/6I.
9]/11) 5S 62 Sl./6I. 57/60 58/61. 58/62 61./61 5~/64 54/62 5)/61
BIo/II5 59/61. 58/61. 60/61. 6)/60 62/60 S4/56 510/56 58/58 56/S4 55/55
PI&I... s..~ IJ.r ~ 111. JlO 0/-1.1 0/-1.1, -1.8/-1.) -2.0/-1.4 0/-1.1, -1.8/-1.2
Al/ 0/-1.2 -1.6/-1.3 -1.8/-1.4 0/-1.4
A)/1.4 -1.7/-1.6 -1.8/-1.7 -2.1/-2.1 -1.8/-1.6 -1.8/-1.7 -2.0/-1.6 -2.2/-1.9 -2.0/-2.0 -2.0/-1.5 -1.8/-1.8
A5/111 -1.5/0 -1.8/0 -2.1/0 -1.6/-1.4 -1.7/-1.5 -1.8/-1.8 -1.8/-1.8 -1.6/0 -1.5/0 -1.5/-1. 5
B2/&) -2.1/-1.1, -2.0/-1." -2.6/-1.9 -2.)/-1.7 -2.2/-1.7 -2.4/-1.8 -2.)/-2.0 -2.1/-1.5 -2.2/-1.6 -1.8/-1.2
B4/B5 -1.0/~.9 -1.0/~.9 -1.)/-1." -1.0/-1.1 -1.5/-1.0 -1.8/-1.5 -1.9/-1.5 -1.7/-1.) -1.9/-1.4 -1.6/-1.1
PI&I... 111..-.. ~ In. H~ 0/12.5 0/1).0 0/11.5 11.5/12.0 11.0/11.5 11.0/12.0 11.0/11.5 0/12.0 12. 5/12.0
Al/1.2 0/12.0
A)/IU, 12.5/10.0 12.5/10.0 12.0/9.0 12'f{9.5 11.5/10.0 11.5/9.0 11.t.O 12.0/LO.0 12.0/10.0 12.0/lO.0
AS/51 12. S/O 12.5/0 12.0/0 12.0 0.5 11.5/10.0 11.5/10.5 11.s 10.0 12 . 5/0 12.0/0 12.0/12.0
B2/&) 1).0/14.0 1).0/1).5 1).0/1).0 12.S/1).5 12.0/1).0 12.0/13.0 11.S/12.S 14.0/13.5 13.0/13.0 1). S/13. 5
84/115 12.0/12.5 12.5/11.0 11.5/11.5 11.0/10.5 11.0/10.0 10.0/11.0 9.S/10.5 12.0/12.0 12.0/11.0 12 .0/12.0
PI&I... Cool IJ.1' - 'P
Al/A2 92/165 910/172 97/172 182/174 182/176 18)/175 182/175 105/176 10:1/170 181/178
A)/1.4 178/174 177/178 177/174 100/174 180/176 178/174 178/174 181/177 1OO/11'J 178/170
A5/Bl 17X88 17X9O 17S/92 176/16#! 176/16#! 173/1U, 17S/164 174/10) 170/'13 172/166
B2/I;) 192 176 185 176 178/117 185/178 185/176 100/174 180/175 172/176 174/178 187/178
84/B5 180/174 180,tc;67 188/161. 178/186 178/174 166/116 165/176 166/17) 16J,/l14 168/119
'_or I!PIt Al/A2 0/10.6 0 0.0 0/9.8 8.J/9.0 7.2/9.0 7.8/8.8 8.0/9.0 0/10.8 0/10.0 8.8/8.7
A)/1.4 10.3/8.) 10.6/5.9 9.8/8.0 9.)/7.4 9.)/1.5 9.1/7.6 9.1/7.5 11.1/9.4 11.0/9.4 6.7/6.8 ~
AS/ll1 10.1/0 11.2/0 10.2/0 9.)/6.8 9.)/6.8 9.)/8.2 9.4/8.2 U.)/O 11.7./0 9.J/8.5 ex>
1;211;) 10'X9.4 ll'X9.6 10.%8.6 9. S/8.2 9.5/8.2 9.2/8.9 9.2/8.9 le.8/LO.2 10.5/10.0 8.5/8.1 +'
BIo/II5 11.0 11.3 11.2 1.4 10.0 :.0.4 9.7/9.8 9.6/9.8 5.9/9.2 5.9/9.2 10.6/10.8 10.5/10.5 8.5/8.9
""-,,... - ~ Ope
Al/A2 0/88 0/89 0/84 65/80 60/80 64/80 65/80 f{95 f{96 79/00
A)/1.4 83/94 82/95 - 8'ih1 73/86 74/86 86/98 86/98 '13100 99 100 94/99
A 5/81 96/0 1!J3/0 84/0 67/55 76/55 86/67 B8/tB "~O 100/0 79/77
B2/11) 82/91 82/90 89/88 71/8) 71/82 84/79 . 85/81 94 91 94/'11 98/81
B4/D5 80/8) 00/8) 78/82 73/76 84/74 61./96 66/97 96/100 96/100 83/82
MlOCw.AtlWJS
Dna IAY.l - In. -1.5 -1.5 -1.5 -1.5 -1.5 -1.1 -1.0 -1.3 -1.5 -1.2
PIIoI Nou.lo TU\ A/D - 0&&. -)0/-)0 -15/'30 -5/0 -10/-30 % '12/-30 .6/0 '25/-30 '12/0 '11. 5/-30
~A/D-~' 3.3/2.7 3.)/).4 ).8/3.6 ).9/4.8 4.)/3.8 ).5/).2 ).5/3.0 3.0/..8 3.5/4.U 4.0/4.6
Pon Ampo A/B 74/73 73/72 72/72 77/7S 77/75 73/73 72/7) 72/77 72/77 78/n
C/D 75/82 75/82 74/82 78/85 7X85 7X81 7X80 78/85 78/84 80/88
11) pon J.mpo A/B 160/ll.O lSO/151 152/145 182/180 lOO 100 155 L61 155 160 15B/158 155/157 100/175
C/O 143/147 141/1108 142/147 157/162 156/164 139/142 1)9/142 H6/1SO 144/1 SO 161/165
Bo1lor C1ro. Pump :i&" 42/40 42/41 42/11J 42/1,0 42/11J 4)/41 42/41 43/41 4)/41 42/41
C/D 41/41 41/1.2 41/42 1.1/41 41/41 41/41 42/42 41/41 41/42 1.2/42
rD P... lnlo\ V ODe 0 - ~ Ope ;e/ 58
A/B 510/510 Sl./53 510/52 5e/58 58/57 56/56 56/55 60/59 59/59
C/D tIJ/59 59/58 58/58 65/61. 64/63 57/56 57/>6 62/62 62/61 65/61.
111 Pon - ~~Pood 72/71 72/72 n/71 85/81. 8)/8) 73/7) 73/72 7)/72 71/71 78/76
C/D tB/68 66/66 66/66 72/72 72/72 6)/63 64/61. 68/67 66/66 73/72
SH = Vo.l.. A/B - ~ Ope % 0/4) XO % % % % % % %
iQj (!I;:;H Vo.l.. A/D - ~ Opw % 0/108 012 % 0/37. 5 % 11/25 % 0/5 %
DUIpoI' Poo. A - ~ Ope
Top AWt./Coal 6/6 6/6 6/6 6/) )/6 )/6 6/) 6/6 6/6 3/6
Ala./Coal 6/6 6/6 6/3 6/) )/6 )/6 6/3 6/4 6/6 3/6
AWl./Cool )/6 )/6 4/3 4/) 4/6 4/6 3/3 :'/1. 3/6 1./6
Aux./Coal 3/6 3/6 3/) 1,/3 4/6 )/6 )/) 3/.. 3/6 4/6
AWl'/Cool .3/6 3/6 )/) 3/3 4/6 )/6 3/) J/4 ;/6 4/6
Bot. Au.x. ) ) 3 3 I. ) 3 3 3 4
Daapor Po.. B - ~ Open
Top AWl./Cool 6/6 6/6 /J6 6/3 )/6 3/6 6/3 6/6 6/6 J/~
1UJl./Coal'" 6/6 6/6 6/3 6/) 3/6 3/6 6/) 6/4 6/6 3/6
'" Aux./CoAl 3/6 J/6 4/) 4/) 4/6 4/6 )/3 1./4 J/6 4/6
~ Aux./Coo.l )/6 J/6 )/) 4/) 4/6 4/6 )/) 3/4 3/6 4/~
Aux./Cool 3/6 3/6 )/) )/J 4/6 )/6 3/3 3/4 3/6 4/6
'" &t..,Au..J.. ) ) ) ) 4 ) ) 3 3 4
;;
-------
- .1 - - 1"\
.~01.L~ L v
C.....ut 16)S7
Pro Jee t 9OOC1I6
i83~A~LQ1
Tt.Sf MO.
D&to
\Co.. 1.044 - '"
,1;.,,;:; - l03U1/HR
Main ::it..aa {lnt.el.)
Mal.n ~t.e&ll !/'d
Main SUac Total
Air n"; A/B
Air flo" Tot,&1
hltd,w&t.er (Intec.)
r.ec1-.ur 1'0t.&1
:ill OI.SH Spray 8 LS/RS
kit [)'-"H Spror ~ LSf.2'
0.6O/0.tu
0.1)/0.C8
2.5/2.0
1.0/1.~.
2.)/2.1
2.4/2./;
28
5.0/5. )
6.8/7.0
J.~.
~. .\
).2/)..1
).0/).')
9.5/9.:;
8.8/9. J
990/1030
955/9110
985/101D '
9SO/9'I\
1015
975
100.1
970
610/6).2
29 5/)(X)
273/26)
1l0/101
113/1.15
0.60/0.75
0.W/0.70
2.8/2.1
1.1/1.)
2.5/2.)
2.5/).5
26.5
5.0/5.)
6.5/7.0
2.8
).8
2.1/2.)
2.6/2.5
10.4/1D.0
9.0/9.8
1016/1060
976/1000
1010/1026
990/995
1045
1000
10)0
1005
610/612
292/296
2h4/266
106/I 10
U3/111
602/616
614/6OlI
538/S/.2
SOI/522
786/71)
9)2/9)1
1l0l/1076
1034/103 1
))6
))5
lQJATA
~
4/20/71
~O
34']).1
1800/1'/W
)650
1500/1490
)000
32)).2
)2SO
0/0
0/0
)20
)SO
0/0
0/0
59
85
~ 58/1391
2140
2010/2000
)5e/H)
19SO
2320
)89/@
-O.SO/-o.25
0.55/0.55
0.15/0.10
2.5/1.9
0.95/1.2
2.3/2.0
2.)/3.0
29
5.0/5.0
6.0/7.0
).)
4.0
-/-
).3/).)
9.5/9.0
8.0/7.5
1015/1065
900/1000
980/995
950/970
1045
1000
985
968
610/610
)05/)08
276/267
114/116
118/ti 5
598/6Ce
601/600
5~6/550
512/S22
794/768
9)2/8I!J
1095/1036
1032/995
32)
)21
Co==hu~~!.a!'! ~-&i!'!~r!!'::. !n!:..
Field Test.1n& atd
Per(onunce keau.lt s
U
4/20/11
4)8
)482.2
1790/17)0
3600
1485/aoo
JOOO
)211.3
)100
0/0
0/0
295
330
0/0
0/0
59
84
1455/1)7~
2145
2010/<005
)58/352
1995
2320
)91/)90
-0.55/-0.28
0.55/0.62
0.~/0.70
2.5/1.9
0.95/1.2
2.4/2.0
2.5/).1
29
~. 5/4. 5
6.0/6.1
2.6
).6
2.~/2. 5
2.6/2.5
9.5/9.0
8.1/8.8
1019/1060
990/1015
lOC~/1018
985/980
1060
1015
1025
lcOO
610/612
)0/,/)10
279/222
116/U8
=/1l6
597/610
608/602
505/S51
516/S28
79)/77~
9)1/919
lloo/I066
lCX, 6/1 o:!S
)22
)20
&9.
4/22/71
1020
)067.8
1600/1560
3210
Ij,J,Q/1300
2890
)360.0
)450
0/0
0/0
270
3SO
0/0
0/0
65
9~
1)68/1341
.2500
2l.2O/2410
355/345
23',0
2720
374/)76
I-'
ex>
I..n
-0.70/-0.35
0.50/0.55
0.11/0.0)
2.2/1.7
0.9/1.1
2.2/2.0
2.)/2.6
24.9
5.5/5.5
6.0/6.1
).0
).6
2J./2.5
2.6/2.6
8.9/8.7
7.7/8.0
9)8/985
870/9SO
9"A/9J1J
87)/811
964
935
915
867
600/600
m/2e;.
255/250
103/106
WI/I c/,
581/ S93
590/584
522/525
~9J/SO~
715/75)
852i845
1012/9S3
916/900
)61
359
-------
Boiler 0
Cootroct 16351
ProJoct 'iOOO'J6
CQ!lbwstl0n t.n!1neer1ns. Inc.
Field Teat.Ing ard
Port4 51./0 54/0 50/65 50/65 5%0 5%0 49/6) ~8/62 JI~
B2/83 5V60 56/61 51/61 53/61 53/63 57 00 57 61 54/00 54/00
BI./B5 55/5~ 61/ 5~ 00/54 51./~9 5V~9 61/61 61/61 53/~7 5)/~ 57/54
Pol.. s..ppl, 11.. - 1ft. 1I:zO -2.2/-1.4 -1.5/-1.0 0/-{).3 0/-1.3 -1.9/-1.~ -2.S/-1.9 0/-1.1
Al/u 0/-1.0 . 0/-{).9 -2.0,'-1.2
A)/ AI" -2.0/-1.8 -2.7/-1.1 -1.8/-1.5 -2.0/-1.5 -1.8/-1.0 -1.1/-0.9 -1.9/-1.5 -2.2/-1.8 -2.2/-1.9 -2.3/-1. 6
A5/B1 -2.0/-1.8 -1.7/0 -1.5/0 -2.0/-1.3 -1.5/-1.0 -1.0/0 -1.9/0 -2.1/-1.3 -2.1/-1.8 -2.1/0
B2/83 -2.2/-1.8 -2.0/-1.5 -2.0/-1.4 -2.1/-1.5 -1.~/-1.0 -2.1/-1.3 -1.9/-1.3 -1.9/-1.2 -2.1/-1.8 -2.5/-1.1
81./B5 -2.0/-1.1 -1.1/-1.5 -1.1/-1.0 -1.6/-1.2 -1.3/-0.8 -1.2/-{).5 -1.3/-{).9 -1.5/-1.0 -2.8/-1.~ -1. 7/-1.4
. N.. Dhch&rs' - 10. H:zO 0/12.0
u/u 12.0/ll.5 0/12.5 0/12.1 12.5/U.0 12.5/12.0 0/1).0 0/12.0 12.0/11.0 12.5/12.?
A31 AI" U.0/l0.0 12.0/10.5 12.0/U.5 10.0/10.0 1l.5/10.0 12.9/U.5 12.0/10. S 11.5/10.0 11.5/10.0 12.0/10.0
A 5/81 12.0/12.0 12.5/0 12.5/0 12.0/12.0 11.5/11.5 13.0/0 12.5/0 U.5/U.5 11.5/11.5 12.0/0
8V83 13.0/13.0 12.0/1).5 1).0/1).5 .1).0/1).0 13.0/1).0 12.5/1).5 12.5/1).5 13.5/1).5 l).O/LJ.o 12.5/12.5
111./85 1l.0/11.0 12.0/12.0 11.5/11.5 U.0/I0.0 11.5/10.5 11.5/U.5 11.0/11.5 11.0/11.0 U .0/10.0 11.0/11.0
N.. Coal A1r - 'f
Al/U 182/170 102/110 108/170 178/169 176/169 102/170 102/169 177/H,i, 175/169 t05/168
03/AI" 180/165 178/165 178/161 178/161 178/166 178/166 177 /166 118/11>4 178/166 178/167
A5/81 170/163 177/103 177/106 175/167 175/168 176/104 178/106 174/166 174/168 176/10~ I-'
82/83 185/175 195/175 190/176 190/171 170/170' 176/176 170/175 188/172 186/172 16)/175
111./85 168/180 1111./175 1111./175 186/114 116/189 16)/116 184/175 177/166 178/186 183/117 ())
Food'" iII'II u/u 9.0/6.6 0/9.1 0/9.6 9.0/8.7 9.2/8.8 0/10.3 0/10.4 8.8/8.5 8.6/8.2 0/10.8 0-
A3/AI" 6.8/8.1 9 .6/10.0 9.6/10.0 8.~/6.3 6.6/6.5 11.2/10.6 11.2/10.6 6.2/6.0 8.0/1.9 11.2/12.0
A5/B1 8.9/8.5 10.)/0 10.)/0 1.9/9.2 6.1/9.3 1l.7/0 11.1/0 1.6/6.1 1.6/7.9 11.8/0
s2/83 8.5/6.6 10.6/9.2 9./(9.2 8.6/8.9 9.2/9.3 11.2/10.5 11.1/10.5 8.1/6.~ 8.0/8.2 12.1./10.9
111./&5 8.5/8.9 9.8/10.3 9.9 10.3 8.0/8.1 1.7/7.4 10.1/U.5 10.1/U.6 1.6/7.1 . 7.5/7.7 10.9/12.7
Emau.otor - ~ Open
. Al/u 78/79 0/'10 0/90 82/78 6)/00 0/95 0/95 60/77 79/77 0/100
.)/ AI" 93/99 92/96 92/98 79/88 00/69 9B/1oo 97/100 73/87 77/86 98/100
A5/81 79/77 ~O 98/0 71/100 73/100 1Xt 1~0 57/100 69/100 100/0
82/8) 97/82 100 86 loo;{87 100/84 100/88 97 96 6695 100/62 82/8) 100/62
BI./85 83/8) 9 100 9~ 100 00/70 78/66 9!1 100 96/100 77/62 77/1iJ. 86/100
HI S;w.AlW..US
Dr.... wvel - In. -1.1 -1.6 -1.4 -1.8 -1.6 -1.6 -1.5 -1.5 -1.6 -1.6
Fu.l ~o..lo TUt I./B - 1)0&. +3/0 -30/-30 % +15/-30 +12.5/0 -30/-30 % +20/-)0 -~/O %
~A/8-" 3.9/4.4 2.7/2.7 2.5/2.5 ).2/2.~ 2.1/2.7 3.4/3.~ 3.6/).6 2.5/2.5. 2.5/2.5 2.1/2.~
fAn AmpA I./B 76/75 72/71 12/71 71/15 71./72 1)/74 13/73 72/70 71/69 70/10
C!D 79/87 7)/77 7f{78 15/61 7X6~ 7X61 7X62 73/80 72/79 72/17
1D FAn o..p. I./B 178/110 134/137 1~ 1)1 1)9/151 1~ 156 U2 54 152 165 139/1~5 ~0/11.2 130/136
C/D 100/167 125/125 125/12 \ 135/133 IJ5/lJ~ 131/1.100 14l/1~ 127/125 1)2/l26 120/122
BQUer Clrc. P\&ap Aapa
A/B 1.3/1.2 ~7/45 ~/~6 ~6/45 1.7/~ ~/~3 ~/42 ~5/45 46/46 4)/4)
C!D ~/1.2 ~5/45 45/40 ~/~ ~/~ 43/~ 1.2/ ~3 ~5/45 ~/45 1.2/~
I'D Fon Inlet Van.. - J Upon
I./B 56/56 53/52 5)/5~ 55/5~ 54/5~ ~/57 56/56 51/50 51/50 . 50/50
C/!J 1>4/6) 57/51 55/55 60/59 6)/62 62/62 66/65 58/58 57/57 56/55
1D FAn - ~ Speed
A/8 76/73 66/66 65/65 10/70 73/72 12/72 76/16 71/10 69/68 6)/63
C!D 73/12 56/55 55/55 62/62 6)/63 6)/63 67/67 56/58 59/59 51/50
:iH D.:iIt VAl.. A/B - 1> Open % % % .0/0 % % % % % %
rill m.:iH VAl.. AlB - 1> Open 0/2S % % % % % % % % %
c...per i'oo. A - 1> ~ 3/3
rap 11U./Coal 6/3 6/6 6/6 2/6 6/6 6/6 2/6 4/) 6/6
O....../Cool 6/3 6/2 6/6 )/) 2/6 6/6 6/6 2/6 )/) 2/6
.... ./coal 1./3 )/2 2/6 3/3 )/6 2/6 ~/2 )/6 )/3 )/6
O,.../Cool 1./3 . 3/2 2/6 3/3 )/6 )/6 V2 3/6 )/) 3/6
OIU./COal 3/3 )/2 2/6 )/3 3/6 3/6 1./2 )/6 )/3 3/6
r Sot. A:a. 3 3 ) 3 4 3 ~ 4 4 3
_per Po.. 6 - i Open 2/6
rap AIU./Coal 6/) 6/6 6/6 4/3 6/6 6/6 2/6 1./3 6/1>
.. o..../co&l 6/) 6/2 6/6 )/3 2/6 6/6 6/6 2/6 )/) 2/0
... '..../coAl 1./3 )/2 2/6 )/3 3/6 2/6 ~/2 3/6 )/3 3/6
0
O..../Cool 1./3 )/2 2/6 )/J )/6 )/6 4/2 )/6 )/) )/1>
o..../Coal )" 3/2 2/6 3/3 )/6 3/6 1./2 3/6 3/3 )/1>
/.
Bo~. Aw.. 3 ) 3 ~ 3 ) ~ ) 4 3
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Boiler 0 C~t.1Ufi r.nginGiTiui, I:=.
n.ld T..tln4 ar.4
ecm.....t 16) 57 Perr :It... A/B 1S20/lJ.85 1620/1590 1'/00/1650 1550/1490 11,10/1)8) 14)0/1)90 1425/1)90 lJoOO/1)75 1425/UOO
IIo.1D 5c.... T ot.&l )090 ~ 1~ 2950 2710 21150 2900 2850 27)0
Ur now A/B lIo2D/1385 1620 U50/U25 1090/930 lL2O/looo 1120/1000 1000/975 103)/920
I.1r no"Tot.&l 2820 )OZ) )1)0 2100 2020 2000 2120 2000 1m
'.ed.v:iUI' {Int. C.) )27).8 )4/,6.2 )552.0 :,54).6 2)46.2 2520.0 2400.5 2)66.6 24.l'.9
reodvat.or T T"",. 51! OUt. A/B 0.50/0.60 0.50/0.60 0.50/0.60 O.,",>/O.'JIJ 0.)5/0.)0 0.65/0.70 0.65/0.65 0.)0/0.)0 0.)0/0.)0
BIt DIU. A/B O. Ulo. OJ 0.12/0.010 0.14/0..50 . O.IJ'.,IO.02 . 0.08/0.01, 0.08/0.04 0.07/0.04 0.6'/0. 'JIJ 0.35/0.)5
.Low T_. 51! OUt. A/B 2.2/1.7 2.)/1.9 2. 5/2.0 1.5/1.1 1.~.1 l'Yol.6 1.5/1.5 1.~.1 1.4/1.1
Ie"". DIrt. A/B 0.85/1.0 0.9/1.2 1.0/1.2 O. ;5/1.5 0.5 0.75 0.5 0.65 0.5/0.75 0.45 0.55 0.5/0.7
All OUt. A/B 2.1/1.9 2J/2.0 2.2/2.1 1.8/1.8 1.6/1.2 1.6/1.1 1.6/1.1 1.6/1.1 1.)/1.0
C/O 2.1/2.8 2.)/).1 2.5/).10 1.5/2.0 1.5/1.9 1.5/2.1 1.4/2.0 1.4/1.7 1.5/1.9
CI.... """" OUt. (1':IlD) 24.8 26.0 21.0 )6 )5.5 34.5 )5 )5 )4
PI) 'UI Dhch. A/B 4.5/4.5 5.5/6.0 5.9/6.) 5.0/5.0 4.)/10.) 5.5/5.4 4.5/4.5 4.)/4.5 4.0/4.0
c/O 5.9/6.0 7.0/7.0 7.1/'1.2 6.0/6.0 4.5/4.) 6.2/6.5 M/5.5 5.0/5.5 5.0/5.0
Ur 1.o&oUIa All A-B 2.6 ).6 4.0 ).5 1.9 4.0 ).0 ).1 ).5
C...{) ).) 4.) 4.5 4.4 2.) 4.8 4.0 ).9 2.5
W1n4bo1 A 1!.5~ 2.0/2.) ).2/).) ).)/).5 ,.4/).10 1.5/1.6 ).S/).6 2.S/).0 2.9/).0 2.6/2.6
- B RS/L5 2.)/2.) ).)/).) ).6/).5 3.1./).4 1.({l.6 ).9/4.2 ).0/).0 2.9/).2 2.5/2.5
10 'AA w~ AlB 8.7/8.2 9.0/9.S 9.5/9.1 5,9/5.9 6.5/5.5 6.5/5.5 6.5/5.5 6.1/5.) 6.0/5.)
c/O 7.4/8.0 8.1/8.9 8.5/9.2 5.0/5.7 5.0/5.7 5.2/6.0 5.)/6.0 5.0/5.6 501/5.8
TUKlUTUUS - 'r
011 Outl~ A B/L 953/995 960/985 955/982 t!I 5/905 900/926 900/922 909/9)0 925/960 91.5/975
III! Outlet A B/L 890/917 900/900 900/905 eo5/845 822/851 826/844 827/872 855/905 875/920
III OUU~ B ilL 945/955 947/915 91.5/960 '-75/895 885/9010 893/914 '/<)6/921 915/911J 925/950
iH OuU~ B B/L 915/905 890/918 895/910 0.l5/a:l5 817/843 819/950 826/872 1!I.5/800 865/905
51! Ml.~ " 970 975 9!JJ 910 920 ~lJ 932 950 920
8H Outlet. A 905 905 995 9J,O 846 840 861. 895 910
III Outlot 8 955 968 940 1!90 90) 905 924 935 940
iH Mln 8 908 908 895 8)0 8~5 840 859 sao 895
So"". L1mt 1\&be. A/B 601/604 600/603 fI:xJ/605 ~;95/S8I) 594/597 590/ S9) 595/597 585/590 590/600
au 1.0& Y1n& All A/B 2111/286 285/280 2I!8/2/!) ~Y:!/265 264/2/1/ 270/272 268/272 28)/2/!) 2110/280
C/O 254/259 262/267 26)/269 2~0/2)5 239/243 2/J./2)8 247/245 249/246 249/250
Air ("l0l'1o& All A/8 106/108 107 /ill 100/112 95/100 109/112 112/115 11)/116 UIlll8 116/118
c/O 109/107 110/109 1l4/lll 100/100 . 114/112 117/llIo 118/1l6 11S/116 118/116
.8Qu iilhrlna All A/B -/- 590/594 59)/599 ~47/551 545/550 548/553 5109/556 SJ.7/558 HJ/561
- $ -/- 599/598 60)/556 546/549 548/551 552/556 552/S64 551/557 5S4/~
-Ur Leo oUIa All -/- 519/522 5))/52) ',81./494 4JJ9/498 ~92/49S 490/502 50)/500 sa./508
. C/D -/- ~ 96/518 199/5.19 1.6)/~78 ~/AII7 Mil /483 1n/"es 476/491 176/501
.~ Pl.aUIJ Out.let. Hdr. A/B 7741765 791/774 765/756 761/7U 762/750 754/717 774175) 799/77) 006/77 5
fi '!!or. SII o..th~ Hdr. 1,/8 870/87) 897/850 88'1/855 915/31:0 828/805 8)0/805 e29/812 8)7/822 85)/!!:!7
'SH ()oUol Hdr. A/B 1021/990 lO27/1OOO 1021!/995 SIIJ/- 962/915 957/940 972/9Y:! m/971 101S/975
OI/lf DIlll.l !Jar. A/B 9)0/940 91.)/938 90/937 --/- 870/85S 866/865 878/876 9li/898 928/912
~ -9ft Spr&J' \:i.a.".r B )59 )6) 269 279 295 29!. 290 )00
- 51"'" w.~0I' B )57 )60 :b:8 278 291. 29) ;99 297
,~,-'!"'G.',
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Boiler 0
c:cmr.., 1&)57
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CO<:bQ.t1oD J:a~r1.Q4, IDa.
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PertCJ:"DADCo R.oINl t.e
~DARD AND ~e~~'1~UYre~ DAT~
~ ZI. &1 iD. J2 J1 U n Ji. ».
Date 4/Z2/7l 4/22/n 4/Z2/7l 1,/l9/n 4/19/n 4/19/n 4/19/n 4/19/n 4/19/n
cn.e I.oe4 -., us "1 ~ )00 JOO )10 )10 )OS )10
~
IIUl Aaj>8 1.1/1.2 0/59 0/57 0/57 o/~ 0/'16 :!SO 't 59/0 60/0
A3/1.4 WS4 S4/5) :00 55/58 S2/5S 55 SZSS 5%0 53/0
AS/Bl SUO ~o 55~ %0 % 5~0 ~~ 52 1/1 52/1/1
82/B3 596:1 5861 55 6:1 56/62 065 0/65 O/~
84/Bs 61/6:1 61/62 SS/6O &;)/0 ~/O SS/59 SS/55 0/S4 0/5S
p,uy. ~ Air - :t~ 0/-1.6 0/-1.0 0/-0.5 0/-<'.9 0/-2.1 % % -1.0/0 -1.1/0
AJ/1.4 -2.4/-1.9 -1.5/-0.9 -1.)/-0.1 -1.0/-1.2 -2.4/-2.3 -1.1/-0.9 -1.1/-1.8 -1. 5/0 -1.1/0
A5/Bl -2.1/0 -1.0/0 -0.1/0 C!O . % -1.1/0 -1.1/0 -1. S/-o.8 -1.7/-1.0
B2/B3 -2.)/-2.0 -1.1/-1.1 -1.0/-0.9 -1.9/-1.0 -).0/-2.2 0/-0.5 0/-1.2 0/-1.4 0/-1.6
I14/B5 -1.1/-1.1 -1.0/-0.4 -0.9/-0.5 -l.:!/O -2.3/0 -1.0/-0.3 -1.4/-0.9 0/-0.8 0/-1.1
p,uy. D1ecl>erp - In.. H~
U/1.2 0/12.0 0/12.5 0/13.0 01J.;!.0 0/11.0 % % JJ .0/0 JJ .0/0
A3/1.4 U.S/lO.O 12.5/10.0 12.5/10.5 12. 5/1t;:0 U.5/10.0 12.5/11.0 11.5/10.0 12.0/0 12.0/0
AS/Hl 12.0/0 12.0/0 13.0/0 0'0 % 12.0/0 12.S/0 12.5/U.5 12.0/U.5
B2/B3 12 .0/12.1 1).0/13.0 14.0/13.5 13.0/1::';5 12.5/1).0 0/14.0 0/13.0 0/13.0 0/13.5
B4/B 5 10.0/11.5 13.0/12.5 12.0/12.0 13.0/0 11.5/0 13.0/11.0 13.0/11.0 0/12.0 0/12. 0
!'I>ly. Coe.l .ur - 'F
1.1/1.2 103/167 10S/178 100/177 92/]73 9S/185 1"}{95 102/150 17S/1., 1'/!!/1I.I.
A3/1.4 171./166 178/1~ 180/165 178/1'15 178/160 165 181 178/190 175/U8 178/111
A5/Bl 172/100 1 n/102 170/100 83/1!8 8X92 169/95 16X96 176/163 172/160
B2/B3 l8I./l72 186/17. 179/1710 161,/172 158 72 75/140 120 185 112/171 110/170
84/Bs 179/176 179/179 1~78 170/1:)6 173/109 178/165 176/170 110/138 126/162 .....
r_... IIPIC 1.1/1.2 :AM t.7 0 0.0 0/U..2 0/9.7 % % 11.0/0 U.2/o co
AJ/1.4 10. 10.9 10.5 11.) 10.2/11.0 U.O/lJ..O 9.7/9.8 10.5/10.0 10../9.9 10.';0 10.3/0 0:>
A5/Hl 10.8/0 U.O/O 10.8/0 ('/0 % 10.6/0 10.5/0 10.5/10.3 10.5/10.3
B2/BJ U.;a.7 12.2/10.5 ).2.2/10.10 U.6/9.8 U.l/9.2 0/10.9 0/10.7 0/10.8 0/10.7 I
lmaunu, - ~~ 9.).8 9.9/12.10 9.8/12.4 ll.~/O U.O/O 10.8/10.9 10.8/10.8 0/10.5 0/10.6
1.1/1.2 X92 ,%93 %95 .:Ala. (,'8) % %0 100/0 100/0
A3/1.4 90 00 9 00 92 100 H.o 89 ,,(X) ~/1oo 93 72 9./0 95/0
A5/11J. 1,0 1'1,0 1001:' (1/0 %0 8XO 86/0 0:5/100 85/100
B2/!IJ 100 2 100 8 r-/'18 9481. 094 0/94 0/93 0/93
BIo/B5 73/91 79/98 78/96 97/0 93/0 93/86 93/86 0/85 0/<6
KlCW"1tr I ""'EaJS
Dr... w..l - 10. -1.5 -1.7 -2.0 -1.5 -1.7 -1.8 -1.6 -1.6 -1.5
rual .0..10 flU I./B - De,. % -22/-)0 -22/-)0 % -12/+10.5 -12/+10 -12/+10 -12/-10 -12/'10
~I./B-S 2.0/2.0 2.6/2.6 2.8/2.8 2../2,5 2.6/2.6 2.0/2.0 2.6/2.6 2.4/2.4 2.S/2.5
r... ""po 4/B 70/69 72/72 73/73 70/65 66/62 69/64 68/63 66/63 65/63
c/D 7}{16 ~80 %.81 66/72 6X70 6X64 67/72 67:.72 65/72
ID r... .\ape I./B 139 34 13 0 137 5 l2O/1l 5 115 12 U6 113 116/113 llJ:5 110 105/UO
. C/O U9/12O 1.27 /1Jl 13 1/13 5 100/102 100/102 102/1ar. 102/1OJ. 100/102 100/102
8011... C1roc. IWp :ir 104/42 101/40 41./104 53/51 54/S3 SZ/51 B/n S3/5O 52/SO
C/O 42/42 101/41 "/44 52/02 53/S4 SO/52 51/52 50/51 SO/51
ro Fea 1010' V..... - S Ope
4/B 50/49 5I./Slo 56/55 IJJ/.l )6/36 )9/39 37/38 37/38 37/56
c/O 55/5) 59/59 62/62 "/42 42/41 107/46 44/1,4 "/42 55/42
10 r... - S Ope
I./B 63/6) 65/65 69/68 6)/63 61/61. 61/60 /1:)//1:) 51./54 56/55
C/O Sl/51 57/57 60/00 )5/.'4 i.2/41 )7/37 37/)8 )2/32 . ))/32
SIt Dj;SIf Val.. 4/B - s OpeD % % % % % % % % %
l1li ~ \'al... I./B - s OpeD % % % % % % % % %
D&aper Poe. A - S Ope
Top AWl./Coal 6/6 6/6 6/6 1/1 4/.6 1/1 6/6 4/3 2/3
A..../Coe.l 4/.2 6/6 4/2 1/) 2/) 1/1 1/1 1/1 3/6
AWl./Coe.l )/2 2/6 )/2 3/) )/) 2/10 2/3 2/3 2/3
Aux./Coe.l )/2 2/6 3/2 )/) )/) )/10 2/) 2/1 2/1
!ux./Coe.l )/2 2/6 )/2 "/1 3/1 3/4 2/3 1/) 1/)
Bot. Au.. ) 2 ) 1 1 4 ) ) 2
0- Po.. B - S Open
Top Aux./Coe.l 6/6 6/6 6/6 1/1 4/6 1/1 6/6 ./3 2/3
to AWl./Coe.l 4/2 6/6 1./2 1/) 2/3 1/1 1/1 1/1 3/6
~ AUI./Coe.l )/2 2/6 3/2 3/J )/3 2/4 2/3 2/) 2/)
... AWl./Coel 3/2 2/6 3/2 )/J 3/3 3/4 2/3 2/1 2/1
Ir A"" ./Coal )/2 2/6 3/2 1./1 )/1 )/4 2/J 1/) 1/)
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proj~ct 9000096
COli1bustion En9incering, inc.
Field Testing &
Performance Results
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gap i~ .25" - . 50"
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-------
- 192 -
l~SPECnO;; Co: :-iOZZ:'Z C()::?\~7:'!~:~~T :'0:D i'7I~D30X
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-------
A ,.- (+30)
B: -- (0)
- 193 -
UIS1'ECTIO~ OF ~:OZZ:.::: CO:2.\'1T.':::)''T A~m HIXJ30X
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194 - .
I~SPECTIO~ OF ::OZ~:'E CO::?\:\TYE:ir AXu h'I:.'"J30X
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-----
-------
Boiler 0 NOZZLE AIR FLOW DISTRIBUTION ~ lL1.LJ TI:::;TJlhj to
CONTRACT 16357 PERFORMANCE RESULTS
PROJECT 900096
TEST NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14' 15
Compartment Flow-l AUK. % 8.36 8.34 8.01 7.58 5.21 5.01 7.89 8.11 8.42 .5.15 7.65 8.48 9.67 7.19 3.47
2 Coal % 3.38 3..38 3.24 7.57 7.77 8.23 8.15 3.28 3.40 7.87 7.44 3.43 3.90 8.58 9.38
3 AUK. % 15.38 15.36 14.71 13.92 10.25 9.86 14.51 14.94 15.49 10.16 14.07 15.61 17.77 10.68 7.42
4 COill % 8.45 8.48 8.47 7.57 7.77 8.23 8.15 8.23 8.33 7.87 7.44 8.21 9.58 8.58 9.38
5 Aua. % 11.14 11.12 13.44 12.72.12.93 12.44 10.50 13.64' 11. 22 12.83 12.85 11. 30 7.93 10.68 12.04
6 Coal % 8.45 8.48 8.47 7.57 7.77 8.23 8.15 8.23 8.33 7.87 7.44 8.21 9.58 8.58 9.38
7 l.uK. % 11.14 11.12 10.65 :12.72 12.93 12.44 10.50 10.81 11. 22 12.83 12.85 11. 30 7.93 ::10.68 12.04
8 Coal % 8.45 8.48 8.47 7.57 7.77 8.23 8;15 8.23 8.33 7.87 7.l14 8.21 9.58 8.58 9.38
9 Aux. % 11.14 11.12 10.65 10.08 12.93 12.44 10.50 10.81 11.22 12.83 10.19 11. 30 7.93 10.68 12.04
10 Coal % 8.45 8.48 8.47 7.57 7.77 8.23 8.15 8.23 8.33 7.87 7.44 8.21 9.58 8.58 9.38
11 Aux. % 5.66 5.64 5.112 5.13 6.90 6.f.5 5.35 5.'19 5.71 6.85 5.18 5.74 6.55 7.19 6.09
Fuel Compartment rlow % 33.02 33.~0 33.88 37.86 30.03 41.15 40.76 32.911 33.32 39.33 37.21 32.02 30.31 42.90 46.88
Flow Above Center of riring % 60.73 60.71 61.55 53.13 47.80 47.09 53.27 61. 86 60.80 117.82 53.17 60.80 62.39 50.00 46.38
Theoretical Air to Comb. Zone % 91.80 92.13 94.18 115.63 115.52 110.65 109.75 97.73 98.57 115.71 115.511 90.02 87.84 106.33 109.51
....
TEST NO. 16 17 18 19 20 . 21 22 23 30 31 32 33 34 35 ...:>
V>
Compartment Flow-1 AUK. % 8.76 7.62 3.4.5 7.22 9.12 8.63 10.13 8.83 .36 9.38 . .34 13.50 15.38 5.50
2 Coal % 3;511 3.08 9.44 8.56 3.68 3.118 4.09 3.57 .37 4.22 .35 5.46 14.03 13.23
3 Aux. % 16.13 14.01 7.38. 10.69 7.48 14.118 18.63 14.83. .78 8.57 .76 .76 .97 18.98.
4 Coal % 8.77 8.13 9.44 8.56 9.28 8.29 9.57 7.88 12.73 11. 85 .36 .36 .46 5.76
5 Aux. % 7.20 12.80 11.97 10.69 12.14 11.117 8.32 11. 76 18.26 13.91 11.:)1 11. 08 14.05 11.69
6 Coal % 8.77 7.30 9.44 8.56 9.28 8. ~'9 9.57 7.88 12.73 11.85 13.13 12.52 14.02 13.23
7 Aux. % 11. 68 12.80 11.97 10.69 12.14 11.1!7 8.32 11. 76 18.26 13.91 17.87 11.08 14.05 11.69
8 Coal % 8.77 7.30 9.44 8.56 9.28 8.~9 9.57 7.88 12.73 11. 85 13.13 12.52 .46 .38
9 Aux. % 11. 68 12.80 11. 97 10.69 12.14 11.117 8.32 11. 76 23.05 13.91 17.87 11. 08 .97 .81
10 Coal % 8.77 7.30 9.44 8.56 9.28 8.:?9 9.57 7.88 .37 .28 13.13 12.52 14.03 13.23
11 Aux. % 5.93 6.86 6.06 7.22 6.18 5.64 3.91 5.97 .36 .27 12.05 9.12 11. 57 5.50
Fuel Compartment Flow % 35.07 30.02 47.18 42.82 37.14 33.16 38.27 31.51 .38.20 35,55 3g.38 37.55 42.09 39.59
Flow Above Center of Firing % 59.01 59.34 46.40 50.00 57.05 60.:)7 611.46 60.'62 38.85 53.85 50.39 61. 01 51. 89 61. 77
Theoretical Air to Comb. Zone % 93.29 98.84 108.82 109.51 93.77 91.'76 85.68 90.47 108.89 91. 87 102.25 85.93 103.19 108.39
Sheet B?:
-------
Boiler 0
. Contract lbj57
Pro.iect 9000096
l,t):lilJ:l:> LI 1111 l "'J to. 0'0' .., ,.
Field Testinu & .
Perfp.rmqn~p R~sults
VI
::r
ro
ro
M'
CD
W
<=>
NQ (~DJUSTED TO 3% Q2)
~ERSIJS ..
THEORETICAL AIR TO COMBUSTION ZONE
THEORETICAL AIR TO THE COMB. ZONE - %
.PPM of NO Obtained
hom Contra r Room'
Chart RecOrder
..... '
'-D
0-.
0- 3 Mill Tests
o - 4 & 5 Mill Tests
-------
. Bo i 1 p. r 0
TRf,CT 16357
';JECT 900095
- 197 -
COM~USTION ENSI~EERING, I~~.
FIEL~ TESTI~IS & P:.Rr-ORf1MICE
RESULTS
IIIND30X AND NOZZLE CO~:PART:.£NT GEOI"ETRY.
USED HI NOZZLE / I R FLO:.I DISTRI3UTION PROSRM-1
Nozzle Nozzle # of Free Area Duct Area
Compartment Compartment Dampers Per at. Nozzle at Damper
# Height - Ins. Compartment - Fr2 - FT2
1 ~ 1.74
19.25 2 4.61
2 20.00 2 . 0.70 4.76
3
3.20
3
8.38
35.25
4
2
0.70
4..76 .
20.00
5
3.20
8.38
3
35.25
6
4.76
2
0.70
20.00 .
7
3.20
8.38
35.25
3
8
4.76
2
0.70
20.00. .
9 35.25 3 3.20 8.38
10 20.00 2 0.70 4.76
11 ~ 2 1.74 4.61
Sheet -:31
-------
Baile r 0
Contract 16357
Pr.oject 900096
Mill
% - 200 ~'1esh
Mill
% - 200 Hesh
Mill
. % - 200 Mesh
Hill
%. -.200 Mesh
1.98 -
PULVERIZER 'Fnm:ITSS TEST
"B" FlJ1GACE
crassifier SetLin~ - 0
B~l
70~8
B~.2.
7r.:o. .
B-3.
79-.2.
Classifier 'Setting - .1
B-1
74..6
B-2
69.:2
B-3
71.13
cras-surer -Sett:ing ..,. -2
B~l
74..2
B-'2
73:0.
B-3
72:.D.
CIassifier'Settin~ - ~
B-1
79..6
B~2
78"..0
B-;}
84~O
Combu!:,'.ian Eng-ineeririg, Inc..
Fjeld Testing and
'Performance Results
B-4
65~8
B-4
65,; 8
B-h
71:8
. B-l.
75.6
B-5
82.6
B-5
8.0.2
B-5
82.:.6
B-5
85.8
-------
. ~ 199 -
APPENDIX B-2
.
BOILER Q .
Final Report
to
ESSO RESEARCH AND ENGINEERING.
FOR
ENGINEERING. AND CONSULTING SERVICES
. PROVID;ED
IN CONNECTION WITH A FIELD TEST PROGRAM
TO MEASURE GASEOUS EMISSIONS FROM
A BABCOCK & WILCOX STEAM GENERATOR
July 16, 1971
i .
. I
/
-------
OBJECTIVE
200 -
The objective of this contract was to measure boiler thermal
performance in connection with an ESSO Research and Engineering Company
field test program to measure gaseous emissions from a Babcock & Wilcox
steam generator. The gaseous emission of prime concern during these
tests was the measurement of nitric oxide (NO) in the flue gas.
BACKGROUND AND SCOPE OF 'vlORK
This report covers the results of the engineering and consulting
services provided by B&W to ERE in connection with an ERE field test
program to measure gaseous emissions from steam generators of' various
boiler manufacturers. '
The Air Pollution Control Office of the Environmental Protection
Agency ~~d ERE requested that the Babcock & Wilcox Company provide
engineering and consulting services to aid AP.CO and ERE in a field
test program (Systems Study of Nitrogen Oxide Control Methods for
Stationary Sources Phase II, CPA 70-90). '
This program was to determine the level of nitric oxide emitted from
several B&W steam generators. Testing of one B&W steam generator was
done Under 00,[ I S contract with ERE. .
The scope of test work for which B&W proposed to supply engineering
services was:
5.
1.
Help the contractor select the boilers, negotiate with the
utility owner-operators, plan the testing, and set the
experimentation limits for safe and proper testing.
Perform a pre-testing check-out of the boiler to assure
that it is in proper operating condition for the testing.
2.
3.
Acquire data on the thermal performance of the boiler while
the contractor measures the NOx and other emissions.
Help the contractor and boiler operators to solve any
problems which might be encountered during testing.
4.
6.
Monitor the boiler operatiQIl during testing to assure that
unsafe or unacceptable operation is avoided.
Evaluate thermal performance data and assist the contractor
in evaluating the NOx and other emissions data, as required.
. .
-------
- 201 -
OF WORK
ft was decided to test a coal fired once through Universal Pressure
Steam Generator designated as Boiler Q. Figure 1. The steam generator
has the following full load design conditions:
Main Steam Flow 4,900,000 pounds per hour
Main Steam Pressure 2,400 pounds per square inch
Ma~ Steam Temperature 1,0530F
Reheat Steam Flow 3,450,000 pounds per hour
Reheat Steam Pressure 305 pounds per square inch
Reheat Steam Temperature 1,0030F
The steam generator is fired by 14 Babcock & Wilcox cyclone
burners which are arranged as ShOin1 in Figure 2. Seven cyclones
are on the front wall and seven are on the rear ivall. Each
cyclone is 10 feet in diameter and 12 feet long. Coal preparation
for firing requires a minimum of 90% by weight passing through a
Number 4 mesh sieve. Coal flow to each cyclone is controlled by
lt~ own coal feeder. The steam generator was put in commercial
'.operation on May 19,1963, with a nominal full load electrical
output of 650 megawatts (050,000 kilowatts).
A meeting was held with ERE, the boiler owner-operator and B&W at the
steam plant on April 27, 1971 to discuss the test program and set.
experimentation limits. The pl'ii4e concarr:,:: ;)f th~ Babcock ~ ~'lilcr)x .
Company for these tests ~ere; the maintaining of a minimum limit
on total air of 122% to prevent. iron sulfide formation, and the
preventing of slag chilling to limit slag tapping problems.
Load changes were dependent upon operation requirements.
A proposed test program was formulated by ESSO following the
meeting and the proposed test program was submitted to the boiler-operator.
A copy of this proposed test program is included as Figure 5. Test
,runs which could not be made were deleted and the resulting test
schedule consisted of 6 test runs. These test runs are tabulated
in Figure 6.
Pre':'testlng consisted of a.test run designated as "A" on .
May 10, 1971. Data accumulated during this run were compared
with the design data and previous test data; it was found that
the boiler '.ras operating near design temperatures, pressures and
flows. From .this comparison it was determined that the steam .
gen~rato~ was in proper operating condition for testing.
-------
- 202 -
PERFORMANCE OF ITEl1 ~
In preparation for determining thermal. performance it was
decided that the following items would be desirable indications
of equipment operation during test runs:
1.
Panel board or computer data points indicating temperatures,
pressures and flows affecting the boiler.
Panel board indications of damper positions.
2.
3.
Boiler efficiency as calculated by the Affi1E Short Form
(including air heater leakage). .
Reheat flow calculated by heat balance.
It.
5.
Coal flow.
6. .Recirculated flue gas in pounds per hour.
7.
Flue gas flow in pounds per hour.
The above data would permit the evaluation of changes in thermal
and operating performance if major changes occurred during
nitric oxide testing. Operating performance for long term
~ffects under various operating conditions could not be evaluated
.with the short. duration of testing.
PK~'RTi'()nM l\1'.T,CT~ nF, T'T''RMR 4. ,~1'JD. ~
.--...- -.........- l.:.: -...,,- -------- . --. JJI'
No problems were encountered with. boiler operation during testing
and no unsafe operations were performed.
PERFORMANCE OF ITEM 6
SUMHARY OF PERFORMANCE OF ITEM 6
Thermal performance was evaluated using the data acquired
during testing on May 10, 1971 and May 11, 1971. A summary
sheet showing the results is listed in Figure 4. Included
in the summary are significant items to. compare test results.
No significant changes in thermal performance can be noted
in comparing test runs 1 td 3 and test runs 4 to 6. . No
significant reductions in nitric oxide production were made
by changing operating variables at each of the 2 separate
boiler loads; however, reducing generator output and hence
boiler loading produced a reduced nitric oxide production.
-------
.- 203 -
TEST % OF
BOILER MEGAWATT FULL LOAD NITRIC OXIDE NITRIC OXIDE
NUMBER EFFICIENCY LOADING' . STEAM FLOW AVERAGE HIGH VALUE
MW % PPM PPM
1 91.13 670 96.2 992 1063
4 91.61 542 76.8 731 793
Change +.48 -128 -19.J.,. -261 -270.
% Reduction 19.1% 19.J.,.% 26.3% 25.J.,.%
.
DETAILS OF PERFORMANCE OF ITEM 6
TEST CONDITIONS
Test conditions for the 6 test runs are tabulated in
Figure 6.
Test run 1 and test run 2 vary. gas tempering lUld gas
recirculation to determine the effect on nitric oxide
production. The location of admission of gas recirculation
and t~mper1ng gas to the boiler is shown on Figure 1.
Test run 1 and test run 3 vary coal feeder bias to determine
the effect on nitric oxide production. In test run 3 coal
flow was reduced in the upper row of cyclones, and. increased
in the lower row while maintaining constant boiler load.
Test run 1 and test r~"'1 4 vary boiler load to determine the
effect on nitric oxide productfon. In test run 5 coal flow
was reduced in the upper row of cyclones and increased in the
lower row of cyclones.
Test run 5 and test run 6 vary secondary air to .the upper
cyclones to determine the effect on NO production. During
test run 6 seconaary air was increased to the upper row of
cyclones until the boiler excess 02 increased fr~m .3.9 to
4.9%. . .
The overall effect created in Tests 3, 5, and 6 was to
produce a staging of the burners--a method found to reduce
nitric oxide production in gas and oil fired boilers.
Increased flue gas recirculation (test run 2) was found
helpful in reducing NO in boilers equipped with cell type
burners on gas and oil.
-------
- 204 -
TEST PROCEDURE
When test conditions were obtained and the boiler had reached
steady state conditions test data were recorded. Coal samples
were obtained by the boiler-operator at a location immediately above -
the coal feeders. Fly-ash samples were obtained by the boiler-operator
at the economizer. Fiqure 1 indicates the locations of coal and.
ash samples. Ash samples from the slag tank were not obtained.
Flue gas analysis to determine air heater leakage 'was made at
the ai~ heater inlet and outlet at the two load conditions.
Coal analysis was performed by ERE and the boiler-operator. Proximate
analysis was determined for each of the 6 test runs. Ultimate
analysis was determined for a composite sample of test runs 1,
2, and 3; and test runs 4-, 5, and 6. . .
Per cent combustibles in the flue dust samples were determined
by 'the boil er-operator for each of the test runs.
TEST EQUIPHENT
Test equipm~nt to obtain data for thermal performance consisted
of:
Panel board and computer logged data points.
'Water manometers (when available) to determine gas recircu-
lation fan 'static pressure.
Coal and ash sampling equipment s~pplied by the boiler-operator.
G.aseous emission analyzers supplied by ESSOResear.ch and
Engineering Company.
Gas analysis of flue gas en~ering and leaving the air heater
by TVA.
Coal and ash analysis by ESSO and TVA laboratories.
TEST CALCULATIONS
Boiler efficiency was calculated by the ASME Abbreviated
Efficiency Test Method. This method determines boiler
efficiency by heat loss. The heat losses are recorded in
the ASME test forms. Calculations were based on flue gas
analysis from the boiler-operator because the higher values of excess
oxygen in the ESSO analysis indicated possible leakage of air into
the sampling lines. Dry refuse calculations were based on
the assumption of 70% of the ash went to the slag tank and
30% passed through the boiler. Combustibles in the slag
tank, were assumed to be zero. Unmeasured.losses were assumed
to be 0.6%. These assumptions were based on the test results
. .
-------
. . .';)5 - .
of the acceptance test run by the boiler-:-operator on this boiler. The
as fired heatil1g value of the coal was used for efficiency calculation.
The ultimate analysis was used for the heat loss due to dry gas and the
heat loss due to HZO from the combustion of HZ.
The two composite ultimate analyses by ESSO were converted to 6 as
fired ultimate analyses using the moisture content as determined by the
boiler-operator. The boiler-operator analyses had a higher mositure
content. This ultimate analysis was then used in calculations.
Reheat flow was determined by heat balance around the parallel
flow high pressure feedwater heaters which take extraction
steam from the high pressure turbine and the cold reheat steam.
Losses from the main steam flow are tabulated in the reheat
flow calculation summary.
Coal flow was determined by using total heat output in the
steam, boiler efficiency and the heating value of the coal.
Recirculated gas flow was calculated by using the fan
characteristic curves, motor horsepower, and static pressure
where available. The recirculated gas flow was proportioned
into gas recirculation and tempering gas flow by assuming
flow to be a function of damper position.
Nitric oxide data reduction.of the ESSO test data consisted
of averaging the results of each individual probe for each
test run. All probes were averaged to obtain a test run
aVCT8.ge. Result's shoWl:. in Fig'..1re 4. :i.ndicate t~st run
averages and the high probe average. Nitric oxide values
in this report are as 'recorded and no corrections to a
Uniform oxygen have been made. The higher values 'of excess
oxygen of the ESSO data compared with the bOiler-operator's data indicated
possible leakage of air into the ESSO sampling lines and thus
lowering the concentration of nitric oxide in the sample.
DISCUSSION OF RESULTS
The change in operating conditions of the boiler during the first.
three test runs indicate almost no change in boiler efficiency. The
criterion used is that during normal boiler efficiency testing two of
three test runs must fall within a plus or minus 0.25 percentage point
band. During the first 3 test runs no significant reduction in nitric
oxide production was made by changing the gas recirculation and .
tempering gas or the feeder bias 'of the upper and lower cyclones.
The change in operating conditions during the last 3 tests indicated
. almost no change in boiler efficiency during these tests. Only slight
variations in nitric oxide production were made during the last 3 tests
when feeder 'bias and increased air to the upper cyclones were the
operating variables that were changed.
-------
- 206 -
The change in boiler load from test 1 to test 4 indicated a 25%
reduction in nitric oxide when boiler load was reduced 19.4%. Boiler
efficiency c~anged from 91.13 per cent at the high load to 91.61 per
cent at the low load. A slight increase in efficiency at some lower
loads is not unusual. .
CONCLUSIONS
No significant change in boiler efficiency was experienced during the
tests and nitric oxide production was only decreased significantly by
red1+cing boiler load. .
-------
'- 207 -
FIGURE 1
BOILER Q
rLU£ /JUST
SIIMI'L ING
L OCA T/ON
SECTION iliA
£ss 0 SAMPLE
PROBES
224'-0"
I
COAL
SAMPLE"
Lac A Tlol'l
A BOv£
FCEO£f?5
.YiP
II
NOTE
A
1.'06.
ii' !-~~I
I--,.,.L~,-o"-J-.,~-!-u,..~
ur.,...soo
$0'-0-
I
)O'..~
#0/£ A
WORK. POIN T EL£VA. TION
FOfl (YCt.. ON£ DR/iWJN G
. .
-------
~-
- 208 -
THE BABCOCK Be WILCOX COMPA-NY
No r £:
PU/?NA c C 32' D££P
(,3'WIV£
~
l3oIL£R.
15' 0" /6' 6" - /1/ b # /5'0"
/6' ,"
26'3"
9'6"
--L
q
1-
..3
2.
I
6' ') II
16 I (:/'
/,' 611
/6 I 6 II
b';hl-
WORK POINT
£LCVA TION
CYCLONE AI?/? ANGEM£"NT
I~ TO TA L 7 ..sHOWN
VIEW FACING F/(DNT OR REAR- WALL
. EACH CYCLCJN£ 10' DIAMETER 12' LONG
CUSTOMER
SUDJECT
£550 .
eYe L 0 IV EAR RAN G L": r-1 OJ T
Jon No. /3 f W I)~-,O
FliTUR£ 2
OV E.P.SZMA/IIA
DATE 6 - 3 - 71
-------
- 209 -
THE BABCOCK & WILCOX COMPANY
.~
~
£:
I L ER.
~
~OIJE 2-
7'~,1f
~
. ,o,eoBE /
7'''/
. -
f/lOBe 1- PRoBE J 80
-- 7' Lf" 7' f'--
, I
I
T
/.5' 0 II
I.
~~'6"~ l' ~
SEC!T/OIV A A
£ E C
f7l{.os£ Puc r PROIl £'
7'1{ 17'4"
z.:~/1,1I
~
~I
T -6- +
I . ,
+ "t-
I ,
/5' 0" + +
1 I I
~
~" }, 0" i
1'.6 "
ECONOMIzE/? O()TLET t:JtJcr
ONE SHOWN
LO~l1r/oN of ;: YERr/~IIL ?!f(J8£'S Mfl/fKE/J
IJ£PT/I V 3 SAMPLE Pl?oB£ T(.)B£S .sHowN
roR ON£' 'p/eoB£
,
CUSTOMER £' S SO
SUBJECT GA S r'/?OB£ SAM PLC LO(!A TIONS
JOB No. B(w UO-IO
FIr; u/T£ .:5
BY E PS
DATE 6 -3-71
an- 801ty
-------
- 210 -
"liDS J20-1
THE BABCOCK & WILCOX COMPANY
TEST /JUI" P. r, R. 1 j!.. 3 4- S G
DATt: K<:> Dfl 'fR. $-10-11 <-ID-" .t; - 10- 71 5 - /,".." 5 -,,-,1 5-1/-7/
M £: C.A '-'HI r TS 1-'\ \lJ ~7o bG. 8 {,(,o S4-2. .550 SSo
MAIIJ 'STEJ\I-'I FLow loOO:lt/h.r: ~., 13. 4 178. 4 7 8 b. 37 52.. '37'13. J7'f?
Rr H EAr PL..ovJ IDOO /kh, 3?3A. 3485 34- ~<1 2. {.. 77 270F\ 2. 1 JI
TOTAL C6/iL rL-OW 1000 -!II\-... 5S~ 556 595 Y I{S, 5 L} 7lf, $ LJ80,5
HEAT ,~ Pur lOb rHIJ/hr S'1 2.5 6f3D 0/85 l/G 80 ~b2.5 IfGlb
-
Hf:Af OUTPtJT lOb Brv!r.r 5397 $&02.. 5612. 'iZ-B8 lfZS7 4 Z 77
£ F f/ t ./ f. lJ c y 0/0 ~1.13 In 1f7 90, 7~ 9f.6/ 9?, O"?. '11,73
As F/R..€D H f: A T. Vf\lVr. Grv/.:l... 10\(,00 /I 03.0 10410 10500 9750 <)~00
FL ur (;AS RE('IRt 1000 #/..... i.{f5 /I So 4$6 I.f 35 '-1'-(0 1./10
GA5 IF:.I...J, PE" P,,/ 1-) (.,. IOOOIlj;..,y 92.5 LiDO Cf70 /075 It) 80 I () 10
"1, ':1 -
o x Y G E I~** % ~OL 1./.0 lJ,D "+,0 3,2, :,.9
C 0 ~** % V~L 11./.6 /L{,b JlI, (., /4. a It/,P, /3, 8 ~
l3ug'Jrr" I~ St:R\I'tE IJ \.H~ 13 E R JI.f ILf ,'-I 1'1 l't Jlf
A I fl. HEll Tr. ~ L£'At.A6E ";,.., g 3 8.? 8.3 12.,2 /2.'- , I. 0 ""
ME",SUQ.t:t> ftlT G"5 T. 0- ~~g 2.C?'1 2.l:{9 ;:''1D ?. 't () 2rrz.
r-
GO~P',F..CT(;\) ~~IT b-/ls)' of 3ot) 310 3/0 :30 b 30b "0 ,q
GA!> FLow To AHTR IDOO~/"'r Gc:2.3 ~2.o0 bbOO '1395 'f & 'to SaoO
Avn~M.[ Fr:t: I) E'"R. .sPH EY ~ 0')) I~
c.'f'~I-O'JE':) . I-'t 8~rrw, RPM /I q 5 IZ-05 '~(.2. ~8 5 /272 12.1f-
t.V~,1 huES S-7 fDP RP H I (!.. 3S 12.42 I () 9~ 103 b 735 181
AvE No' f'P'1 ME'''SUn.(1) I'P M VOl. 'fer?. ' - -'tt i!. If ! joo2. 73/ 77'3 696
AVF o~ °/~ MEA5rJR.tD °In VOL $.',+ S.4 5,'1 $,3 1-/.8 5,5/
A v E 'C 0, 10 MEASIlxE:D 01-. VOL 13.0 /3.2..' 13.0 13,3 13,£"" 12,9
, H, r. ~ P ~ 0 13 E NUMBER. N u p...IfH R. 3 3 3~+ 2. 4 4-
HIC,H l.Jo VAtl)1:: ' PPH VOL If) {...~ 'I ~I ID I/?. 7'73 a1l8 77b
~CALC.UI.ATEr>
** Heasured bv
boiler-operator
.
CUSTOMeR E.SSo JOB /10. C3f.W OP-ID
SUBJECT TEST R(~ul.."'S' 5UMp.I\f\P...~ SHEEr F/ G UR£', 4
BY E P S
OATf. fr.-8 -71
-------
- 211 -
FIGURE 5
BOILER q
~.
. '--ER tJ ('.'" . (" £ /J
No
~
/~.s / P /? O~ flilp1-L
,.
.-
PiA N :+:.
'I r~S r l?.ts!.MJ-LgJ~ /J A
L, 700 M w) l. 1,
J,(At./... ,SI
CY&L""'t$
. F I ~ I,JG
('" .0 &.0
I?,.-I' f",o"" I? (,I,v I Ii-' /1'-' '! 1': f.~' . 'is)
S .I'd /J1 GLJ . L 3 (40 (J M (..I.) t_---
S1. (1"1' P R~ SJ (7;, l'pl..Jl f ,,(f)L. r:
J"~ (019",/..., IJ Ifl. d ~~' (0)< )0:0<"
o 0.'<.0 xOItO
. "
0, (Pr-,.-{ ft., bA )I. S CJ
. A, "p,.~..,. f'.). M IrJ II
P...(VJ/NJ" 7 1'-
--2!.~~2 I(J
Pt..fJ/-..J:J!. L./ /EJrRo/oJJ Pre. f)",y (RIJ. ~tJ~'" ~,,.J 1
If Ti""1t 1:1*.r/l"I~)
/.., L~ L~
(". Sf S'- S'l I JI/
-, ~
- .
P, Rt I J' (II) i~
~\. 3 7 I .
I
~\.-" R, 1/ e I
-
R".. 2- '" h.) !I~
,
P/..rJ/'l:J71 DA,Y I (f c) 1..1-' I -.s" 1 p~ y ~ ( (! (,J N~ ,''' -/ u ).)~ - 3 ( ~ VAl.!. /1 ../ b)
t.1 I-\- 1-1.
S, S, S".... J~ s~
PI «., 'I J~I (II) " (I.f? ~
- -
1<'2- (/ J.) 1/ 2
"v R. (/!) ~ 7
Rz. (I il) 3 (Il.) 7
J1~G/7J
I1.R. C,
-------
FIGURE 6
BOILER Q NO PROGRAM
- EXCESS CYCLONE
RUN AIR FLUE GAS FEEDER AIR
NO. LOAD LEVEL RECIRCULATION TEMPERING BIAS BIAS
1 Max. 120% Minimum Maximum Zero Zero
2 Max. 120% Increase Decrease Zero Zero
3 Max. 120~ Minimum Maximum +Bottom Zero
-Top
-
4 550 mw 12~ + Minimum Maximum Zero Zero
5 550 mw 120% + . . Minimum Maximum Bottom Normal Zero
-Top (50%)
6 550 mw 120 + Minimum .Maximum Bottom Normal Zero-BottorI:
-Top (5~) + - Top
~
I-'
.~
,
5-6-71
O.S. Office
-------
- 213
APPENDIX C
Representative samples of fuels fired were obtained from the
boilers tested in this study. This section of the report presents a
summary of the fuel compositions determined for coal, oil and gas
fired boilers.
. ,
. ,"
-------
- 214-
APPF.;N!)tX (-1
~l:!g2
rn'Jfit:late "'r..I\"~{s t Bv \Ie I ~ht t!lt It:.1ce AM Ivlth :. 'P.....'Jl!t ht --1
...,d.Jtile OJ(y~"n Ii!!\' ~:; ;::d,~~;:"l
6o!.lu PU:l 1"('. M;;'Ii!lture "5h MoIItter CIII:1,,<:In H\'dr<, en Nit rl'llen Su trut' (hv iJlff.\ ~r:'/ ::,
.. .. ., .. H .' .. A> ., I
Rec'd O'y Ree'd Ory R.c'd O'y Rec'd "'y R~c 'd O'y Rec'd O'i Rec'd O'y Rec'd O'y R.'C' 'J Ny
C 1-6 1.18 12.0 ! 18.0. '.70 1.60 1.82 I IZ9ll
C 1-6 8.1.. 12.(.9 29.0 119.3 73.01 .4.4/0 1.09 2.21 1)114
C 1.6 6.95 \<.2 61.02 4.22 1.38 1.59 12E01
C 1.6 1.98 16.65 68.6) , .... .f.B 1.0') 2.91 11.S9b
r 1.2 1.14 14.23 14.39 1).4 '4.2 I. 1..1\ 4.61 1.38 1.39 1.17 1.18 "".13 .18 12719 2SH
F 3-< . 1.41 14.00 14.20 30.3 130.7 12.6 13.6 , ' .61 <.68 lo)] L)') 1.14 1.16 , .87 .94 12375 JOSq I
P 1.4 1.29 12.81 lJ.53 JJ.I 31.3 69.2 73.1 4.52 4.77' 1.31 1.38 0.12 ~.16 6.15 ' ."'9 113~2 30 fO
p 1.1. 6.64 11. .06 15.06 32.4 )1.0.7 66.7 11.\ 4.2~ 4.S8 1.36 1.46 0.61 0.72 6.29 .11. It6]10 p.s04 I
17 .93 I
o ClT.'Jp. of
17 .21,32 6.94 16.87 32.49 60.18 5.06 1.24 3.98 14,]2 10912
0 Cre,p. of
3.15.35 6.1\ 17 .93 32.51 59.\1 4.91 1.27 3.82 12.50 10161
0 1.105 12.69 13.71 35.40 38.25 63.97 69.12 \.33 4.86 1.24 , 1.34 3.38 3.65 15.42 .52 116186 2583
0 Reject 4 1.<8 55.41 56.31 40.36 . 0.96 )973 OJ)
c 8.15 20.35 22.1& 3L36 }/. .1\ 56.64 51.67 4.86 4.29 1.15 1.25 10.17 .54 IOn! 1".:'"
0 ReJecl 3) 3.56 100.19 101.67 1.0.02 ~1.50 6691 .9;10
0 6.82 16.42 11.62 32.\5 34.94 61.39 .5.88 '.' \.03 4.51 1.18 1.27 3.42 3.67 11055 IE""
0 Reject I] 2.\0 41.10 G.8.31 28.92 '9.66 \801 956
0 COd 1 9 8.80 16.69 18.30 33.14 36.31. 59.\\ 6\.30 \.15 4.56 1.21 1.32 3.80 .17 13.61 .35 10195 18];
0 Reject 9 1.79 56.13 57.15 1.1.21 1.96 3774 843
0 I 6.28 2.18 14.14 1\.38 )).96 35.45 1.\.02 6.99 2.47 .18 11550 LOSS 1.44
0 2 8.53 2.06 15.65 16.76 3\ .91 38.45 39.91 2.i3 II .18 .48 10914 It>B1. 0.86
0 3 8.41 1.53 13.40 110.102 37.18 40.00 40.95 '4.05 3.62 .M 110M. 1882 0.58
0 4 8.50 l. 37 12.94 IJ .91 36.65 39.\0 41.91 . 5.18 3.\9 .81 11334 221; 0.16
0 \ 8.51 1.71 13.52 14.53 37.17 39.93 40.80 43.53 3.30 ).\1. IU26 1953 0.18
0 Reject 5 23.03 68.32
0 6 1.99 1.1.4 17.02 18.23 3\ .06 37.5':1 39.93 42.77 3.51. 3.79 10655 1414 0.42
0 1 8.47 1.66 16.77 18.02 31. .58 J7 .15 40.18 4).17 4.03 '.J) 10Mb 1482 h
0 8 8.29 1.21. 15.41 16.60 35.92 38.68 40.38 ).48 3.61 3.95 10988 18H 0.14
0 Reject 8 32.'8 ~b.50
0 9 8.54 1.S'2 16.1\ 11.39 3\.04 37.73 40.27 1.3.36 3.66 .91. 10898 un 0.40
0 10 7.65 1.70 11.09 18.\9 3J .84 36.02 41.42 44.09 4.19 .1.6 10115 1405 0.))
0 11 8.\1 1.46 18.17 19.57 33.44 36.02 39.88 '-2.95 4.01.8 .3\ 10)82 1181 D.]:!
0 12 7.76 1.24 16.96 18.16 34.46 36.90 40.82 43.10 3.13 3.99 10189 1551 0.21
0 I] 8.10 1.52 11 .24 18.48 32.90 35.25 41.76 44.75 3.66 3.92 10590 13108 0.39
0 Reject I] 24.63 58.10
0 \4 9.14 1.61 19.08 20.66 32 .78 35.50 .. .00 62.2) 3.39 3.67 I 10156 0991 0.t.8
0 15 8.10 1.10 19.81 21.30 33.81 )6.24 38 .22 0.96 4.03 .32 10131 0858 0.58'
0 16 1.38 1.22 16.65 11.16 33.52 35.15 42.45 <5.21 3.45 .68 lr;.~~E 1623 0.30
0 17 ; 1.54 1.26 15.78 16.85 34.l2 )6.44 ~2 .S6 4S .105 3.41 .il tU>2j r l11Z o. J8 ,
o 18 7.94 I.]] 16.80 18.07 31..,21 36.\7 I 41.08 '4.03 3.54 1.19 '10612 14U 0.32 !
G Rcj..:c:t.. 18 35 .69j 38.51 i I I ;~i;J b.41 ~~~~; ,! 658
0 19 8./1 t.1.9 1\.70 16.94 37.90 ~ J .06 , 0.50
0 20 9.88 LS3 15.22 16.63 35.05 38.30 39.85 1.).54 3.68 ~.02 11027 2049 3.62
0 21 6.4\ 1.36 12 .54 13.22 )7.87 39.93 £3.11. 45.£9 3.45 .610 11632 :!265 1.21
0 Reject 21 29.<8 59.37
0 22 7.59 1.14 13.52 14.47 35.7~ 3B.21o 43.11. '6.1S 3.6\ .90 11415 2211 --
0 23 6.88 1.35 13 .63 14.44 35.5 37.65 43.95 46.56 3.83 .06 .1514 2197 1.09
0 30 7.38 1.\8 22.19 23.\8 "roo 38.36 40.76 4.22 .1.8 (:l911, 0535 ;2.~1
0 31 '.'l" 20.21 21.58 32.65 34.87 3~ .06 4L71 3.72 .97 10193 0885 0.79
0 32 7.4~ 1.19 20.81 22.09 32.22 34.20 39.49 41.92 3.1\ .98 10222 0850 1.21
0 Reject 32 21.41 69.74 I
o 33 6.26 1.65 20.19 21.18 34.3 35.99 39.2\ 41.18 1..28 .1.9 10421 Q9}/. 1.)9
o 34 7.02 1.82 22.9 24.26 32.5 }/..3\ 37.47 39.\7 4.20 .1.1. 9615 0216 1.90
o 35 7.89 1.85 19.1 21.06 34.0 36.26 38.32 40.83 3.83 .08 10185 0852 1.80
: I
H Compo of IL
12.13.14.1.5 7.87 1\.1 31.61 61.1.5 5.04 1.30 3.30 lJ.16 1103)
H Coa::p. of 16
17,18.19,20 8.00 15.99 32.6 61.16 5.14 1.35 3.32 !J.03 10900
H Compo of
8,6A,9.11A 1.58 14.1.! 32.0 62.82 5.12 1.110 2.\3 13.64 11211
H Compo of
1.7,6 1.29 13.9 32.2 63.87 5.08 1.)9 2.29 13.38 11356
H 1 9.3 9.3 14.) 15.8 33.6 3].1 42.8 41.1 2.1. .1 loa10 1990
H 1 9.3 9.3 It..O IS.4 )3.6 31.1 (.).1 47.5 2.1. .6 10940 2000
H 10 9.1. 9.4 1J.9 15.) 33.6 )7.1 43.1 47.6 2.4 .6 10910 ~ 110
H 6 9.8 9.8 14.2 15.7 32.1 3\.6 I.).? 48.7 2.\ .8 lQqOO 2080
H II 9.9 9.9 14.5 16.1 33.2 36.9 42.4 41.0 3.1 .1. 10820 2010
H 12 9.7 9.1 14.6 16.2 32.1 35.6 43.6 48.2 3.\ .1. 10630 199Q
H 13 9.\ 9.\ 16.2 11.9 32.8 36.2 41.5 45.9 3.\ .9 11620 1130
H 14 10.0 10.0 1S.8 11.5 32.0 ]5.5 42.2 47.0 3.2 .5 ta620 1800
H 8 9.1 9.1 lI..2 U.1 33.0 36.6 1.3.1 41.1 2.3 .6 ...dOl'll. 2120
H 6A 9.' 9.5 13.1 l4.5 33.8 31.3 <3.6 G.8.2 2.4 .1 IIlJO 2300
H 9 9.1. 9.1. 14.5 16.0 :\3.1 31.2 42.4 46.8 2.8 .1 118\0 1980
H 1'-' 9.2 9.2 13.8 15.2 )].8 3J.2 t.3.2 41.6 2.\ .1 1()Q)0 21)t.O
H 15 9.9 9.9 15.0 16.6 32.4 36.0 42.7 41.4 3.\ .9 IOBOO IqQO
H 17 9.1 9.1 16.1.8 18.2 33.6 37.2 1.0.) lo4.6 3.1 .1. 10';';0 1680
" 18 10.2 10.2 14.7 16.4 )4.8 38.8 40.3 44.8 3.1 .5 10100 19.:'0
H 16 10.3 10.3 15.7 17.\ )J.1 31.6 40.3 44.Q 3.3 .1 10';60 1"0
H 19 9.\ 9.\ 15.S 17.) 34.3 J7.9 40.4 44.11J 3.6 .0 IObbO 1180
H 20 9.4 9.1. 12.6 13.7 )).8 39.5 42.4 46.8 2.3 .5 tt210 nQO
Q Camp. of
1.2 6. 3 6.16 15 .62 31.0 61.64 5.05 1.30 3.60 14.9S 11090
Q Cemp. of
4.5 6. 6 8.44 21.91 30.3 '4.39 4.71 1.08 4.45 13.1.1 91tt5
Q 1 8.6 17.1 36.8 1.\.\ .1 IbOO
Q 2 8.8 . 1\.\ 39.2 45.3 .9 20QO
Q 3 9.3 19.6 31.3 43.% .3 1470
Q 4 10.4 21.2 36.9 '1.«J .5 1170
Q \ 11.2 22.9 36.3 100.8 .9 I)
-------
- 215 -
APPENDIX C-2 ,
OIL ANALYSES
~
.
ASh C H} N Sulfur Fe Ni j V HHV I Kin. Vis.
Boiler Run No. Wt. % \olt. % Wt. % Wt. % Wt. % pprn pprn i pprn llTU!lb at 210° F
J 1-4 0.04 86.3 111.6 0.29 0.94 8 ,7 I 56 18,820
J 0:09 87.8 i 11.4 0.32 0.60 48 9 18 18 , 81 7
t !
i L 1-5 0.02 85 .15 ~ 11. 76 0.53 0.46 2.0 7.5 ~ 29 19 , 185 35.86
! "
I
~ K 1-15 0.04 86.49 ~12.06 0.62 0.99 12 23 i 100 18,921 303
t ~ [;
~ ~,
I '
A '11 0.011 85.16; 11. 82 0.36 0.45 6.5 25 19 18.989 ' 6.22
{ I~
A 15-18 0.015 86.30! 12.45 0.21 0.18 2.5 16 I 3.0 19,725, 9.26
~
/i -1-8 ,0.24 4
\ B 0.009 88.07; 11. 38 0.31 1.0 3 18.946 16.97
I
J B 117-24 0.10 87.77 ~11.33 -0.41 0.31 4.0 7.0 3.0 18,795 39.12
~ #
~ D 1-8 ' 0.35 88.15 111.13 0.46 0.42 7 12 11 18,773 45.05
~
I H !9-16 0.010 I 0.44 5 20 12 I 8.72
86.51 112.24 ,0.30 19,235 l
c 'F 86.02 12.62 '0.25 0.46 8 11
7 ',1-5,8-10 0.007 2.5 19,315' 7.58
~ 36;-29 i12 ,06 J O.!f2 ~
~ ..... 1,. 2 & 7 ' 0".022 c. ~4 ' I. 2/. 21 18,990! 17.63
' v j~~T
. 18,966 i
f G 7,12,15-20 0.025 186. 35 111.68 I 0.42 0.44 11 34 20 16.73
L-
I
I
,
"'-~"
,.
APPENDIX C-3
TYPICAL GAS ANALYSIS
HHV ~
tomponents Mole % BTU!ft-
02 .02 0
N2 1.01 0
CH4 91.41 927
C2H6 4.49 80
C02 1.40 0
C3Ha 1.32 33
i-C4H10 0.09 3
n-C4H10 0.17 6
, i-C5 H12 0.05 2
n-C' H 0.04 2,
5 12 -
Tot a1 100.00 1053
-------
216
Unc.lassified
~curit C!Qssil,cQt!on -" . s
DOCUMENT CONTROL DATA. R /!, D
(Socurlty C'ID..It'callon o( tltlo. bod... o( ab.tr.ct .nd Ind../ntf Ct"Inot""on muo' boo ontor.d ,,"'.n th. 0"01131/'0 rl ,. e/...",.d
1. O~IGINATIf04G ACTIVITY (C0f'J'orolo ltuthM) 12.0. Af;PORT 11tTC\JAITY CLA.I'FICATIOt-.!
Esso Research and Engineering Company
Government Research Laboratory
Linden, New Jersey 07036
J. REPOAT TITL.E
Unclassified
2". GROUP
N/A
Systematic Field Study of NOx Emission Control Methods for Utility Boilers
.. O£SCRIPTIVE NOTItI (Typo of "'pOII and Ine/u.'vo dal..)
Final Report, June 1, 1970 to July 31, 1971
B. ~\U THORIS, (FI,., rurm-, mlddl. In/Uol, III.' n.mo)
William Bartok, Allen R. Crawford and Gregory J. Piegari
........
e. RltPOR T DA Tit
7G. TOTAL NO. orr PAGES
710. ~IO. OF R£FI
December 31, 1971
82
u. CONTRACT OR GRANT NO.
N. O."GIHATOR'D REPORT HUW'I!I£RII.
CPA 70-90
b. PROJI:C THO.
GRU .4GNOS. 71
e.
.b. OTHER REPOAT HOIOI (An" ollt., n&lD1bere f!I.''''''' b. ."'tlned
"'.. report)
d.
10. DIJ'T",eUTION .7A 71:...£.. 7
Approved for Public Release, Distribution Unlimited.
11. $UPP'LEMENTARY NOTEI
u. Sponsoring ctlVlty
Office of Air Programs of
the Environmental Protection
Agency
I'. AQIT"''''CT
'As a major part of Esso's "Systems Study of Nitrogen Oxide Control Methods
for Stationary Sources in Phase II," funded by the EPA under Contract No. CPA 70-90,
a utility boiler field test program was conducted. The objectives of this study were
to determine new or improved NO emission factors by fossil fuel type and boiler design,
and to assess the scope of app11cability of combustion modification techniques for
controlling NO emissions from such installations. In addition, the concentrations of
x
other combustion flue gas species were also determined, to evaluate the E:ffect of
combustion modification techniques on the emission of other potential pollutants, such
as unburned combustibles.
A specially designed mobile sampling-analytical van was assembled for the
purpose of this boiler test program. This system was equipped with continuous
monitor1ng instrumentation for the measurement of NO, NOZ' C02' 0Z' CO and hydrocarbons,
with the later addition of an S02 monitor. Probing of the flue. gases from boiler
duct-work was accomplished by simultaneously withdrawing sample streams from 12
different locations, varied as dictated by the duct configuration. Usually, four sample
streams compositing the contents of three probes each were monitored during test runs.
(Continued)
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1~73
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217
ABS1RACT (Continued)
A statistically designed test program was conducted with the
cooperation of utility owner-operators. Boilers to be tested in the
program were selected based on fuel type fired, boiler size and design,
and special features of interest to NOx emission control. The objective
was to make the boilers selected a reasonable "micro-sample" of the
U.S. boiler population. Wall-fired, tangentially-fired, cycJone-fired,
and vertically-fired boilers were tested in the program. Altogether,
17 boilers and 25 boiler-fuel combinations were tested. .
. The N02 portion of the total NO content in the flue gas was
to average five per cent or less, wheneve~ NO could be measured. For
which did not include N02 measurements, the Nb . was calculated as 105%
. x
of the NO measured.
found
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Major combustion operating parameters investigated included
the variation of boiler load, level of excess air, firing pattern (staged,
"off-stoichiometric", or "biased firing"), flue gas recirculation, burner
tilt, and air preheat temperature. It was found that while NO emission
levels reached very high levels (on the order of 1000 ppm) in 1arge gas
fired boilers, combustion modifications, particularly low excess air
firing and staged air supply resulted in some cases in emission ~eductions
at full load on the order of 80%. However, even for gas fired boilers,
,the degree of effectiveness of combustion modifications varied with
. individual boile~ characteristics; such as burner design and spacing.
Load reductions resulted in large reductions in NO emissions for gas
x
fired boilers.
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Similar trends on the effectiveness of combustion modifications
were observed with fuel oil firing, albeit with a lesser degree of
effectiveness. NO emission reduction from oil firing is less responsive
to load changes ana the application of combustion modification techniques
is somewhat more difficult than in gas firing.
In coal firing, promising exploratory data were obtained on
two of the seven coal fired boilers tested. For coal, the key to
NO reductions (apart from operating under reduced load) appears to be
th~ firing of burners with substoichiometric quantities of air, followed by
second stage air injection for the burn-out of combustibles. This was
accomplished in a 175 MW front wall fired boiler and in a 575 MW
tangentially fired boiler with better than 50% reductions in NOx'
operating at 80-85% of full load. Boiler manufacturers participated
in testing three coal fired boilers manufactured by them to assess
the steam-side consequences (i.e., effects on thermal performance,
slagging characteristics, coal in the fly-ash, and other boiler
'operability features) of applying combustion modifications. In the
short-term tests conducted in this program, the boiler manufacturers
(Babcock and Wilcox, Combustion Engineering'and Foster-Wheeler) did
not find undue problems caused by combustion modifications.
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218
ABSTRACT (Continued)
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Unburned combustible emissions, i.e., CO and hydrocarbons were
found to be very low under base-line boiler operating conditions for all
boilers tested. However, using low excess air firing, the CO levels can
increase sharply, and in fact, set the lower limit on excess air. In
tests where unburned carbon in the fly ash was measurE~d by boiler manu-
facturers, combustion modifications (staging with low excess air firing)
did not result in increased carbon in the fly ash. More detailed testing
will be needed under carefully controlled conditions.
The emission factors established in this study in conjunction
with the overall correlations developed for NOx emissions will allow
making better estimates for individual boilers, according to fuel type
fired, boiler size and design.
It is concluded that modification of combustion operating
conditions offers good promise for the reduction of NOx emissions from
utility boilers; Further cooperative testing with boiler owner-
pperators and manufacturers are required to optimize and demonstrate
the general applicability of these techniques to the control of NOx
emissions from gas and oil fired installations and to establish their
real potential for coal fired boilers.
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