r/EPA
United States
Environmental Protection
Agency
Region 5
230 South Dearborn Street
Chicago, Illinois 60604
EPA 905/9-82-003'
April 1982
Environmental Evaluation of
European Powerplant
Cooling Systems
A Polish Research Project
-------
EPA Number: 905/9-82-003
Date: April , 1982
ENVIRONMENTAL EVALUATION OF EUROPEAN POWERPLANT COOLING SYSTEMS
A POLISH RESEARCH PROJECT
By - Mieczyslaw Gadkowski*, Dr. Eng.
Ewa Czarnecka-Nieminska**, Eng.
Hana Spoz-Dragan, Eng.
Institute for Meteorology and Water Management
61 Podlesna Street
01-673 Warsaw, Poland
PL-480 Project No. JB-5-537-4, under auspicies of
Maria Skladowska-Curie Fund.
U.S. Project Officer
Howard Zar
U.S. Project Consultant
Bruce Tichenor
REGION V
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
CHICAGO, ILLINOIS 60604
Ij •*--* %• ~'t\ t'< ir?**, y-\ >-fi -i. *.•• -' - v s y—« , , „ _
u._. L..I, ,01...-•,«..,.{ F-::-!,-c-'on Agency
Region V, L;'\-.-.;-/
230 South O.vUt!; ; -j btrst
Chicago, Illinois 60604
* Current Address - Instalecport, Bab-Al-Mondam, P.O. Box 14076,
Baghdad, Irag
** Current Address - University of Nortre Dame, Notre Dame, Indiana
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DISCLAIMER
This report has been reviewed by the Region V Office of the U.S.
Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or recommendation
for use.
Environment,-, Fr*«a=n Asency
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FOREWARD
This report presents the results of a cooperative study by
the Institute of Meteorology and Water Management of Warsaw, Poland.
Funds were provided by the U.S. EPA under the Special Foreign Currency
Program, P.L. 480, and by Poland under auspicies of the Maria Skladowska-
Curie Fund. The report was submitted in three sections in accord with
Project JB-5-537-4. The three sections and their authors are noted
below:
Part 1. Equipment for Water Treatment and Condenser Cleaning
in Once-Through Cooling Systems - M. Gadkowski
Part 2. Impact of Open and Closed Cooling Systems on Surface Water
Quality - E. Czarnecka, M. Gadkowski and.H. Spoz-Dragan
Part 3. Make-up Water Demand and Water Loss in Closed Cycle
Cooling Systems - M. Gadkowski and H. Spoz-Dragan
111
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ABSTRACT
Section 1 - The following methods of protecting cooling systems against the
detrimental influence of impurities contained in cooling water
are discussed, with emphasis on Polish experience.
- removal of mechanical impurities contained in water drawn for
cooling
- removal of mechanical and chemical sediments formed on condenser
tubes
- protection of cooling systems against the formation of mechanical
and chemical sediment or scale and biological fouling
Current techniques are evaluated and several proposals are presented. It
is apparent that most technical approaches emphasize power production needs,
while technical solutions which take into account both power engineering and
the interests of the environment, such as fish protection, are less common.
Section 2 - Effects of power plant cooling systems on surface water quality
are discussed based on investigations done for this project and
on prior Polish investigations. For open cycle cooling systems,
no significant differences between influent and effluent concen-
trations of metals were determined. For closed cycle cooling
systems, higher concentrations of metals in the effluent were
found than predicted. The possible contribution of washout of
air pollutants in the cooling tower is discussed.
Section 3 - Studies were conducted regarding the relation between evaporative
water loss and makeup water demand at a number of Polish power
plants with closed cycle cooling systems. Comparisons are made
with similar results for other European power stations. Recom-
mendations for reduction of water supply requirements at the
Polish plants are given.
IV
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CONTENTS
Foreward , i i i
Abstract i v
Figures vii
Tables ix
Acknowledgment xi
1. Equipment for water treatment of condenser cleaning in once-through
cooling systems 1
1.1 Cooling System Impurities 1
1.2 Equipment for removal of debris - 2
1.2.1 Floating skimmers 3
1.2.2 Coarse grills 3
1.2.3 Fine grills 6
1.2.4 Traveling screens 8
1.2.5 Revolving drum screens 11
1.2.6 Siphon intakes 11
1.2.7 Shaft intakes 17
1.2.8 Horizontal intakes 17
1.3 Some methods of biological pollution control 17
1.4 Control of chemical impurities 21
1.5 Methods of cleaning condensers 22
1.5.1 Mechanical removal of deposits 22
1.5.2 Chemical cleaning of condensers 22
2. Impact of Open and Closed Cooling Systems on Surface Water Quality
Quality 25
2.1 Open cooling systems 26
2.1.1 Discussion of project results for open cooling systems 26
2.2 Impact of Closed Cooling Systems on Surface Water Quality 33
2.2.1 Discussion of field research results 33
2.2.2 Evaluation of the pollutant load washed out of the air 39
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3. Makeup Water Demand and Water Loss in Closed
Cycle Cooling Systems •. 44
3.1 Makeup water demand analysis for closed cycle cooling
systems 44
3.2 Evaporation losss in cooling towers 44
3.3 Drift - Qd ... .. 52
3.4 Makeup water to the closed cooling system 53
3.4.1 Water treatment plant makeup water demand
Qp 54.
3.4.2 The analysis of demand or make-up water in electric
power plants with closed cooling systems 54
3.5 Total water balance of steam power plants with closed cycle
cool ing systems 61
3.6 Discussion 67
References 70
Appendix
A. Specifications for steam power plants 74
VI
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FIGURES
Number Page
1 Floating skimmers 4
2 Trash bars , 4
3 Plan of mobile screen cleaner 7
4 Action of traveling screens 9
5 Traveling screens at Havre Power Plant 10
6 Different ways of water in-flow through the
revolving drum screens 13
7 Screen structure with double entry cup screens 14
8 Double entry drum screen open water setting 15
9 Siphon intakes at French Power Plants 16
10 Shaft and horizontal intakes 18
11 Overgrowing of surface at Patnow Power Plant 20
(Dreissenia Polimorpha)
12 Mortality of Dreissenia Polimorpha in function of time.. 20
13 Effects of cleaning of the 55 MW condenser produced
by Siemens Company 23
14 Installation for the rusted pipes of the condenser
chemical cleaning 23
15 Location map for Investigated Power Plants 27
VII
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16 Share of evaporative heat exchange in closed cooling systems
based on Baer et al. (1974, 1979) 49
17 Evaporation losses in closed cooling systems in percentage of
cooling water, flow assuming a At of 10°C, based on Baer et al.
(1974, 1979) 49
18 Make-up water consumption coefficients in cu m/h and unit
heat discharge in power plants under investigation 58
19 Make-up water consumption coefficients in cu m/MWh and K
coefficients in power plants under investigation 59
20 Make-up water consumption coefficients in cu m/Gcal and K
coefficients in power plants under investigation 60
21 Daily electric energy production and water consumption in
Power Plant No. 7 63
22 Daily electric energy production and water consumption in
Power Plant No. 9 , 64
23 Daily electric energy production and water consumption in
Power Plant No. 10 65
24 Daily electric energy production and water consumption
in Power Plant No. 11 66
VIII
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TABLES
Number Page
1 Characteristic parameters of coarse grills 5
2 Characteristic parameters of rotary screens 12
3 Comparison of changes of cooling water quality chemistry between
intake and discharge in Polish power plants with open cooling
systems . 28
4 Comparison of changes of cooling water quality chemistry between
intake and discharge in Polish power plants with open cooling
systems 29
5 Range of metal concentrations observed in cooling water in Gdansk,
Rybnik and Skawina power plants 31
6 Comparison of metals concentration changes between the intake
and discharge 32
7 Proportion of intake water from the Nysa Luzycka in the period of
field studies 34
8 Results of cooling water chemical analyses performed from October
to December, 1977 at the Turow power plant 35
9 Results of analysis of cooling water made on June 4, 1975 at the
Laziska power plant 36
10 Results of cooling water chemical analyses carried out by the
Water Management Division of IMWM at the Turow, Miechowice
and Lagisza power plants 38
11 Average values of pollutants concentrations in the air passing
through the cooling tower 40
12 Degree of pollutant wash-out from the air in cooling towers of
the Turow, Miechowice, Lagisza and Laziska power plants .. 41
13 The change of quality of water at the cooling tower 43
14 Evaporation losses in a cooling tower depending on the heat load,
sprayer surface and the cooling tower height 45
15 Balance of water demand for the cooling system in Steam Power
Plant No. 7 (Oct. 1976 - Sept. 1977) 46
16 Cooling tower studies at Neurath C Steam Power Plant 47
17 Evaporation losses in closed cooling systems according to other
authors 51
IX
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18 Drift value in m^/s for a 1 GW Steam Power Plant according to
Heine and Weidlich (1974) ..................................... 52
19 Make-up water demand ....... ......................... ... ....... 55
20 Monthly and annual average make-up water consumption indices in
over the periods under investigation ......... .......... 56
21 Monthly and annual average make-up water consumption indices in
over the periods under investigation .......... ... ..... 57
22 Water consumption for particular purposes in power plants under
investigation m^/MWh ............................ ......... ..... 62
23 Share of fresh water consumption for particular purposes in power
plants under investigation (Percentage) ...... ........... ...... 63
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ACKNOWLEDGMENTS (PART 1)
e
The Principal Investigator gratefully acknowledges the advice and assistance
of the following specialists and colleagues in the research and preparation
of this report:*
- Mr. A. Jakubik, Mr. H. Maciejewski, Mr. M. Mienkins, Mr. P. Kotula,
Mr. E. Rygula of the South Energetics Region for cooperation in the
collection of data concerning water consumption at existing power
plants and for advice on the methods of cleaning condensers.
- Mr. W. Marianski of Central Energetics Design Office "Energoprojekt"
at Warsaw.
- Mr. J. Pacyna., Ms. G. Kmiec, Mr. A. Kuklinski, Mr. A. Lisowski of
the Technical University of Wroclaw for their field and laboratory
investigations.
- Mr. H. Kirnbauer and Mr. A. J. Freedman (VGB Speisewassertagung 1965,
49-57 - special publication).
* It was not possible to contact Dr. Gadkowsk.i in Poland to learn
whether additional acknowledgements are appropriate for Part 2
and 3 of the report.
XI
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1. EQUIPMENT FOR WATER TREATMENT AND CONDENSER CLEANING IN ONCE-THROUGH
COOLING SYSTEMS
1.1 Cooling System Impurities
Impurities found in once-through cooling systems can be categorized
as mechanical, biological or chemical. Some Polish and European experience
with the three types of impurities is described below.
1.11 Mechanical Impurities
Mechanical impurities may consist of parts of trees and plants
floating in the water, tangles or single threads of algae and water fungi
and sediments. These impurities may cause the clogging of intakes and
other devices supplying water to the power plant. The collection and dis-
charge of impurities retained on the intakes may sometimes create a serious
problem. For example, in the Skawina (Poland) Steam Power Plant once-
through cooling system several tons of algae and water fungi growing in the
long inlet channels are collected daily on coarse grids in some periods of
the year.
The clogging of the grills, screens and condensers by fry or by adult
specimens of small fish may cause serious difficulties in the operation of
the wat'ar intake. Cases of clogging of fine grills by fry swarms were noted
on the water intake for the Siekierki Steam Power Plant in Warsaw during the
first two years of operation of the plant. In this period, the catch some-
times amounted to several tons of fry daily. Also, at the Elblag Steam Power
Plant (Elblag, Poland), cases of clogging of condensers by adult specimens
of stickleback (Gasterostens Aculcatus Linne) were noted.
If the water contains large amounts of mineral suspensions, particu-
larly of clay and Kaolin, these impurities may precipitate in the tubes of
condensers.
1.12 Biological Impurities
Biological impurities may include colonies of various water organisms,
which can foul the intake surfaces, or bacteria and small water organisms
that may grow in the condenser tubes. The growth of water organisms in the
condensers hinders the water flow through the condensers, impairs heat ex-
change and favors the development of biological corrosion. Biological
corrosion occurs as a result of emissions by lichen and bacteria of sub-
stances resulting from bio-chemical decomposition.
In Poland, these circumstances have been noted for several years in
the Stalowa Wola Steam Power Plant, which draws water from the relatively
clean San River. During the winter (December and January), fouling of
the condenser tubes by large fibrous floccules composed mainly from Mucor
sp. (Phycomycetes) and Fusarium Aquaeductum (Myco-mycetes) fungi have been
observed quite often; moreover, Sphaerotilus natans, a filamentous bacteria,
have also been seen. The probable cause of the fouling was the waste dis-
charged into the river by a sugar factory situated 70 km upstream of the
water intake. The fouling was controlled by heating empty condensers to
a temperature of 70° C. At this temperature, the fouling organisms were
killed and then washed away by the cooling water. Due to this control
technique, this fouling problem no longer occurs.
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Biological contamination and the risk of fouling of surfaces is particu-
larly important for sea water intakes. This problem is discussed more fully
later in this report.
1.1.3 Chemical Impurities
Chemical impurities
of sediments in condensers
the power plant.
in cooling water may result in the precipitation
or in corrosion of the mechanical components of
The cooling system contains many devices made from various metals or
alloys which form corrosion cells, while the cooling water acts as an electro-
lyte. The joint between copper and steel is particularly susceptible to
electromechanical corrosion, as copper in the presence of sulphide, cyanide
and ammonium ions may pass into the solution and precipitate, coating the
steel surface and forming a cathode of a large area (Kirnbauer A., Freedman
A.J. 1965). The intensity of electrolytic corrosion increases with the
increase of water salinity. The presence of oxygen, carbon dioxide and
dissolved salts, particularly chlorides, sulphides and sulphates, cause
rapid galvanic oxygen corrosion. If the concentration of chlorides in the
cooling water exceeds 150 mg/1, the steel faces the hazard of pitting, and
the deep pits, despite their small diameter, may lead to piercing of the
metal. High concentration of sulphate ions hinders the formation of pro-
tective layers on internal surfaces of tubes made from brass alloys. High
pH may also lead to the destruction of the protective layer on the condenser
tubes. A high concentration of calcium carbonates in the cooling water may
cause the formation of deposits on wooden parts or in the fill of wet cooling
towers. Their weight leads to the breaking off of individual components.
Corrosion of nails and screws may also occur.
Local corrosion may be caused also by sediments formed by:
- chemical impurities in water
- suspensions in water
- microbiological vegetation
At different points in the facility, the sediments have a different
porosity, at times resulting in pitting due to difficult access for air.
1.2 Equipment for Removal of Debris
The following devices are available to remove material from cooling
water prior to the condenser:
- floating skimmers
- coarse grills
- fine grills
- travel ing screens
- revolving drum screens
- siphon intakes
Most of the discussion of these devices that follows is drawn from
Polish experience.
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1.2.1 Floating Skimmers (Fig. 1)
Floating skimmers are situated on the shore line, across the inlet
to the intake. The purpose of these skimmers is to protect the intake
against the inflow of floating material of large size. The skimmers consist
of a number of floating sections of several meters length, flexibly joined
together. The floating sections may be made from metal floats joined together
by means of a platform and also equipped with vertical trash bars. The
length of the trash bars is approximately 1.0 m, and their spacing is 30
- 50 cm. The positioning of the skimmers should allow the floating material
to continue down the river.
1.2.2 Coarse Grills
Coarse grills are common in water intakes for power plants. These
grills are designed to stop large floating objects. They also protect the
next, more sen filtration devices and cooling water pumps against the
risk of damage.
In typical equipment configurations, the intake water passes through
the coarse grills, and then through fine grills or mesh screens. In Hungary,
however, some specialists recommend the use of these three grill, sets:
- coarse grills with a bar spacing of 10 to 12 cm
- medium grills with a bar spacing of 3 to 5 cm
- fine grills with a bar spacing of 0.6 to 1.0 cm
Fine grills with mesh screens of 1 x 1 mm to 3 x 3 mm spacing, may
also be utilized.
Coarse grills are usually constructed from a number of segments made
from flat metal components joined together by means of braces. To facilitate
cleaning, the segments of the grill are positioned at an angle of 15 degrees
from the vertical, although vertical grills can be seen in older installations.
The spacing of the grill bars is from 2.0 to 8.0 cm. In modern installations,
the spacing of the bars is usually from 3.0 to 5.0 cm. Characteristic parame-
ters of coarse grill construction are shown in Fig. 2 where:
CN,- angle of deflection of the grill from the vertical plane,
usually equal to 15 degrees
h - height of the grill, m
b - width of the grill segment, m
c - spacing of the bars, cm
The dimensions of coarse grills used in several power stations are
shown in Table 1. For-the removal of rubbish trapped on coarse grills, grill
cleaners are usually applied; they may be designed as stationary or traveling.
Stationary grill cleaners are located on every span. One traveling cleaner
may serve the whole width of the water intake.
The stationary grill cleaners have the following components:
- a scraper with a rake and devices for the control of operation
- a rubbish chute
- a belt or trough for the removal of the rubbish
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platform
floating skimmer
Rg.1. Floating skimmers
W////////////////'"
Fig.2. Trash bars
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Table 1
GHAHAGTERISTIG PAEM2TERS 0? COARJ3 GRILLS
Power
Station
Starachowice
Patnow I
Patnow II
Gdansk II
Gdansk II
Patnow II
Patnow II
Rhodes
Siekierki II
Opole
Lacq-Artix
Greil
St-Ouen
Ilontereau I
?aire sur
Marne
Montereau II
Martiques -
Ponteau
vpaT, nf. height width mesh snacing ,>
Country "®ar °J: h b c" source of
•* construction /ffl/ /°/ /c°/ information
Poland 1950
" " 1967 :
"' 1967
« -i 970
" 1973
n 1973
" 1973
Greece 1975
^oland under
construction
H ti
France 1956 4.15
» 1956 9.2
11 1 96 3
" 1959
" 1962
" 1964
" 1971 9.12
3.70
3.12
3.12
2.40
4.2C
2.10
2.37
3.00
2.14
2.11
4.0
5.0
4.0 Marian ski
/1978/
4.C »
4.C »
3.0 "
4.0 «
3.0 "
3.0 "
2.0 "
2.5 "
7.2 Pov/er plant Operate
2.5 "
6,0 "
8.0 "
5.0 "
5.0 "
tt
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In the operation of the grill cleaner, free upward and downward
movement of the scraper is important, as well as a provision for the change
of the rake position within a range of approximately 180 degrees. When
the scraper moves downwards, the rake should be deflected from the grill
face, while during upward movement, the rake should adhere to the grill.
The speed of the scraper movement is usually within the limits of 1.5 -
2.0 meter/min.
Traveling cleaners are additionally equipped with a platform facili-
tating the movement of the cleaner, with a travel drive and with a truck for
the removal of rubbish. A diagram of a traveling grill cleaner is shown in
Fig. 3.
1.2.3 Fine Grills
Fine grills are used in older plants as the final screening devices.
The basic construction of these grills is similar to that for coarse grills.
The difference lies in closer spacing of the grill bars. The spacing of bars
in a fine grill lies usually within the limits of 0.5 - 1.0 cm.
The delicate construction of fine grills is one of their major draw-
backs. The need to minimize the bar spacing dictates that very fine bars be
used. Such bars are quite fragile and are subject to mechanical damage.
Serious problems are caused in fine grill installations by the use of elastic
cleaning brushes. These brushes are ineffective in removing the material
caught between the bars. Moreover, these brushes erode very quickly and
require frequent replacement.
Because of the build-up of material on fine grills, the hydraulic re-
sistance, usually kept at a level of approximately 10 cm, (periodically
increases up to 50 cm or higher), causes damage to the grill and sometimes
requires its replacement. Operating experience indicates that in the
future fine grill design should consider the following items:
- High strength bars, resistant to mechanical damage, should be used
- Long bristle cleaning brushes which can extend to the entire depth
of the grills
- Use of two rows of bars
- A mechanism which enables replacement of fine grills from the top
to allow convenient rinsing with high pressure water streams and
facilitates maintenance such as painting
It is expected, however, that even if these additional steps are
taken, the difficulties discussed above may still persist. In Poland, fine
grills have been replaced by traveling screens because of the above mentioned
problems. It is envisioned that fine grills will be left only in one station
(Pom Rzany plant near Szczecin) which has a power output of 240 MW. Satis-
factory operation of fine grills in this power station is a consequence of
the type of water intake utilized. Uater drawn from the river is supplied
to the power station by a wide channel operating as a sedimentation tank.
The construction of these grills is similar to that used in other power
stations. The spacing of the bars is 5 mm.
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Fig.3. Plan of mobile screen cleaner
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1.2.4 Traveling Screens
Traveling screens were introduced in the 1950s with the development
of medium and large steam power plants (above 100 MW). This action was
necessitated largely by intake blockage due to increased water uptake and
the use of large cooling water pumps. At first, two screens were used for
each pump with the screens arranged either in parallel or in series. After
some time, a standard design using one screen for one pump, was adopted.
Diagrams of the construction location and operation of traveling screens
are shown in Figures 4 and 5.
The basic components of traveling screens are cleaning baskets. They
have the form of a frame with a tight mesh screen. The cleaning baskets are
connected by means of articulated joints with driving chains, forming a
closed, moving filtering belt. The belt speed depends on the purity of water
and belt contamination. When the water and the filtering mesh are clean,
the screens may be fixed. When the contamination of the filtering mesh
increases, it must be put into operation and rinsed. Initially, screens
with belt speed of approximately 2.5 m/min. were installed. Currently,
screens with variable belt speed of 1.5 or 3.0 m/min. are installed. The
usefulness of screens with infinitely variable belt speed is being analyzed.
The mesh screen is usually made from bronze, phosp.hor-bronze or stilon,
a synthetic fiber.
The diameter of the wire is between 0.6 - 1.2 mm. The size of the
mesh opening lies within the limits of 2 x 2 to 10 x 10 mm, usually from
4 x 4 to 6 x 6 mm The surface area of the screens.is usually sized 4m^ per
1 m Vs of filtered water. The water flow velocity is maintained within the
limits of 0-3 - 0.5 m/s, but velocities exceeding 0.4 m/s occur when the sur-
face of the screen becomes fouled. In most cases, the resistance of flow of
water through the traveling screens does not exceed 10 cm. In general, the
fouling of the screens is not permitted to exceed 30 per cent of the active
surface.
Two types of construction are used: screens with panels (older types)
and double-wheeled screens (newer types). Also, various inflows to the
screens are used: axial inflow, bottom inflow, lateral inflow. Axial inflow
screens are the most common. The water is directed to the interior of the
screens flow to the sides and through the screen. Then the direction of flow
changes and the water enters the pump structure.
Screens also include emergency gates which open automatically when ex-
cessive hydraulic resistance occurs. Such gates protect the screen against
damage. Because the gates are used rarely and the time of operation with an
open gate is short, no supplementary grills are installed behind them. The
driving mechanisms of the traveling screens are usually located above the
water level on the operators platform. Traveling screens also include nozzles
for washing the screen and devices for the removal of debris.
Difficult operating conditions for the driving chains and the connec-
tions between the baskets and the chains are weak features of traveling screens.
The component parts operate under water for prolonged periods of time. Under
normal operating conditions, they require annual inspection and overhaul.
Polish experience has shown that in climatic zones with harsh winters
the screen driving mechanisms require a casing protecting the screens against
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L,
Elements of the screen •
1 - framing
2- screen drive wheel
3 - baskets
A- mesh screen
5 - pumps chamber
6-emergency gate
Type of construction :
H- double-wheel travelling screen
I - travelling screen with panels
The path of inflow
a) - axial inflow
b)- lateral inflow
c) - bottom inflow
a)
b)
c)
W/////////L—2y//////////M
y/mm
mm/M
Rg A Action of travelling screens
9
-------
'""""'"////ZZZZZZZT/.
<^-~\-~-_ \
i ^ + — — -
Fig. 5. Travelling screens at Havre Power Plant
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icing in order to facilitate the performance of maintenance and overhaul in
winter conditions.- Characteristic parameters of traveling screens are shown
in Table 2 for installations in Poland, France and Greece. The characteristic
parameters of traveling screens include the following:
- inflow capacity (Q), M 3/$
- height of screen /h/ for double-wheeled screens
- length of the fi-ltering belt /L/,m for screens with slides
- width of the filtering belt /b/, m
- size of the mesh, mm
- diameter of the wire, mm
1.2.5 Revolving Drum Screens
Revolving drum screens are an improved type of traveling screen system
which is less susceptible to damage during operation. They have been used in
many power stations in various European countries; for example, Lac-Arctic,
Vaire sur Marne and Porcheville in France, Carragado in Portugal, Northflect
in Great Britain and Limasol in Cyprus.
The filtration of water by revolving drum screens is similar to filtra-
tion by traveling screens. Baskets with mesh screens are mounted on two
wheels which form the basic structure of the drum and its side closure. De-
signs with baskets arranged on the periphery of the revolving drum screen are
most common, but in some cases the baskets are placed on the sides of the drum.
Diagrams of revolving drum screen flow patterns are shown in Figures 6S 7, 8.
The variable factors characterizing revolving drum screens incTude:
- inflow capacity
- dimensions of the revolving drum screen
- type of mesh screen
- rotational speed of the revolving drum screen
In Poland, revolving drum screens have not been used. However, the
design of the first revolving drum screen with an inflow capacity of 10 m 3/s
has been proposed by Marianski (1977). Its characteristics are as follows:
- diameter (0) = 10.0 m
- width (b) = 2.4 m
- phosphor-bronze wires of 5 x 5 mm mesh
- water flow velocity through the screen 0,6 - 0.85 m/s
- maximum rotational speed of the revolving drum screen 5 m/min.
with a range of rotational speeds of 1.2 - 6.0 m/min.
1.2.6 Siphon Intakes
Siphon intakes facilitate selective withdrawal of water from a given
depth and a given distance from the shore. They also ensure more efficient
use of pumps and screening systems. Such facilities provide for less con-
taminated water than a shore intake. Siphon intakes are commonly used in power
stations cooled with sea water. Among power stations cooled with river water,
siphon intakes have been installed in the French power stations at Cordemais
and Vitry sur Seine (Fig. 9). In the Cordemais Power Plant situated on the
Loire River, a design utilizing one siphon for each unit of 700 MW has been
used. Each siphon draws 25.0 m 3/$ of water from the river. The velocity of
water flow through the siphon is 3.0 m/s.
11
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DEBRiS REMOVAL. „•» ->7<£M
MINIMUM WATER LEVEL//
DEBRIS EwlOVP. VS1
SECTION ON A-A
ROTATION
SCREENED
WATER
SCREENED WATER
DIRECTION OF FLOW
UNSCREENED WATER
SCREENED
WATER
Single entry cup screen
Double entry cap screen
Fig.6. DIFFEH12NT WAYS OP WATER IN FLOW THOUGH THE REVOLVING
- SCREENS
/by D«v«lopci8Dt Document for Proposed B»«t Technolosy Available for
Lilainlzing Adverse 2aviroi»3«atal lepact of Cooling wator Xataiee
Struct or aa. 13 «S.i2nvlroaciaiital Prot««tlon AseBCy«T7aaaingio
-------
.*,,.
DOUBLE ENTRY CUP
SCREEN
Figure 7. Screen structure with double entry cup screens
/by Development Document for Proposed Best Technology Available for
^Inlslzing Adverse Environmental lapact of Cooling Water Intake .
Structures.U.S.Environmental Protection Agency.Washington. B.C.
SPA 440/1-74/015.December 1073. 175 p./
14
-------
B
-»-/ -•—~^r.— MESH SCREEN
SECTION A-A
RUBBISH
HOOD
RUBBISH
TROUGH
SCREEN MESH
BOTH SIDES
SYPHON PIPE
TO PUMPS
UNSCREENED
WATEfl
ELEVATION B-B
FIGURE 8. DOUBLE ENTRY DRUMSCREEN OPEN WATER SETTING
for
p.
15
-------
a)
travelling screen
siphon intake
1 ! 1 •
siphon intake
b)
trash bars
travelling screen
Rg.9 . Siphon intakes at French Power Plants
a) Cardemais
b) Vitry Sur-Sein
16
-------
1.2.7 Shaft intakes
For water intakes in deeper lakes and water reservoirs, our proposal is
a siphon- intake in the form of a shaft with bottom water intake (as presented
in Fig. 10 a). It is assumed that this kind of equipment would enable the
withdrawal of water at lower temperatures while reducing the number of fish
at the intake. A cap protecting the intake from the top constitutes an
important part of the system. A cap in the form of a movable platform has
been suggested; it could be removed for cleaning of collected debris. Another
suggestion is to provide the cap with a coarse grill with hooks. The grill
should make it possible to remove coarse impurities settling on the bottom in
the region of water intake. No operating experience on this technique was
found.
1.2.8 Horizontal Intakes
Horizontal water inflow to the cleaning equipment is a characteristic
feature of water intakes in once-through cooling systems. Horizontal flow,
however, causes considerable inflow of trash and aquatic organisms to the
cleaning equipment. Our proposal of a horizontal intake with vertical water
filtration has been suggested to avoid the problem. Fig. lOb illustrates this
kind of equipment.
The filtration pond, protected at the inlet by a coarse grill, is the
basic element of the horizontal intake. A mesh screen, with about a 5 x 5 mm
mesh size, constitutes the floor of 'the pond. Collection chambers under this
screen deliver water to a return basin and then to the pumps. The area of the
filtration pond should ensure the water filtration rate of V<10 cm/s. The pond
should be segmented to allow service for routine cleaning and replacement of
the mesh screen. In addition, horizontal intakes include skimmers and methods
of removing floating trash. Horizontal intakes minimize the mass of material
flowing to the condenser and protect adult fish, as well as fry. This tech-
nique has not yet been used. No operating experience is available.
1.3 Some Methods of Biological Pollution Control
Among the various biological fouling problems which can hinder the
operation of the steam power plant cooling systems, are the following:
- shellfish, which form colonies on the surface of intake and
"pumping stations structures and on the intake pipelines
- algae, fungi and bacteria, which grow mainly in the condensers
and also on the surface of cooling tower fill and other com-
ponents
Colonies of shellfish can be particularly troublesome in sea water
intakes. In Central and Eastern Europe, the fouling by shellfish of water
intakes from lakes and reservoirs can cause serious problems. Specifically,
the presence of the shellfish Dresseia Polimorpha in stagnant water, is
troublesome. This shellfish originates from the catchment area of the Black
Sea and Caspian Sea and has been spread by commerce to a much larger scale.
Under natural conditions, the larval hatching period lasts from June until
August. Larvae of Dresseia Polimorpha swim freely, but adults are sedentary.
Operation of once-through cooling systems causes elevated temperatures which
17
-------
a) shaft intake
pumps
1 - cap
2 - inlet
3 - shaft
4 - coarse grill
5 - travelling screens
b) horizontal intake
stop logs
trash removal
elevator
chamber
\
pumps
1 ii
skimmer
i==i
1 - coarse grill
2- horizontal screen ( 5*5mm size of the mesh)
3- debris log
Fig.10. Shaft and horizontal intakes
18
-------
accelerate the growth cycle of Dresseia Polimorphea. For example, on the
five Konin lakes which are used for the cooling of the Patnow and Konin
Steam Power Plants during 1970, the first appearance of the slowly swimming
Dresseia Polimorpha larvae was observed in April, and by May large numbers
of Dresseia Polimorpha were observed in all the Konin lakes. In May, foul-
ing of intake surfaces by Dresseia Polimorpha was noted. In 1969, at the
Patnow Power Plant, the degree of fouling of the water intake was observed
on artifical substrate with surface areas of 100 cm2. On September 23, 1969,
the number of specimens counted was 381; and on November 11, the number was
364. The size distribution of the Dresseia Polimorpha specimens are shown
in Fig. 11. Much larger colonies of Dresseia Polimorpha have been found
in the Moldavia Power Plant, USSR, which draws water from the Kuchurganski
reservoir. Research conducted in July 1968, Swierdlow, et a!., 1-970, dis-
closed the following:
- layer of mussels, 25 - 50 mm thick
- weight of the wet mass of fouling, 3.6. - 4.0 kg/m2
- number of Dresseia Polimorpha specimens, 90,000 - 200,000/m2
Colonies of Dresseia Polimorpha were covering all moving and stationary
parts of the intake immersed in water. Biological research regarding the
development of Dresseia Polimorpha shows that fouling should be controlled
twice in a year: during the spring (in May) in order to destroy the wintered
forms,and in the fall (in October), in order to destroy generations, of the
current year. In order to find optimum methods for the control of Dresseia
Polimorpha, various chemical agents and thermal methods have been laboratory
tested. Because of the high tolerance of Dresseia Polimorpha, chemical
agents have proven unsuitable for its control. For example, attempts to
control Dresseia Polimorpha by means of copper sulphate CuS04 have shown
that the lethal concentration of CuS04 at 12.5°C is 24,300 mg/1. This dose
is reduced as the temperature increases and the lethal concentration at
27.5°C reaches 300 mg CuS04/l. In Polish surface water, the permissible
concentration of CuS04 is 0.3 mg/1. If copper ions are used, the lethal
concentration is 4 mg/1 Cu at 20-22°C with an exposure time of 48 hours.
For practical purposes, thermal treatment has proven to be more efficient.
The results of laboratory tests of controlling Dresseia Polimorpha by water
heating are shown in Fig. 12. According to Swierdlow (1970), the lethal ex-
posure time of Dresseia Polimorpha at a temperature of 40-49°C is 3 - 15
minutes. At the above mentioned Moldavia Power Plant, a thermal control meth-
od for Dresseia Polimorpha has been used. Water is heated to a temperature of
50°C in the condensers, while the output of the plant was reduced by one half
and the cooling water pumps are switched off. The heated water is directed
immediately to the intake,
A similar method has been applied for control of the growth of shell-
fish in the Bulgarian Warna Power Plant using the saline water of Warne Lake
for cooling. To"prevent fouling, water heated up to 45°C is recirculated to
the intake. The procedure is repeated once a month during the spring and
summer. The first hot water release takes place in April or May. An exposure
time of 50 minutes is used. -
Similar methods of control of Dresseia Polimorpha and other shellfish
have been used at other power plants. The degree of heating and the time
of exposure of each species of fouling organisms needs to be determined.
For example, some water organisms such as Mytilus Edulis and barnacles,
19
-------
Itime of exposure
(h)
3,5
3,0--
2,5--
2,0--
1.5 -•
1.0 -•
0,5 -•
0.0,.
temperature 35°C
temperature 40 °C
H 1 1 H
0 10 20 30 40 50 60 70
90 100 % mortality
Fig. 12 Mortality of Dreissenia Polimorpha in function of time
, number
of individuals
80--
70-
60 • •
50-
40"
30 •-
20--
1
10--
0
0 X <
_ ° X X X
0 n x
o -Sept.23,1969
* - Nov. 11,1969
O
y
x x
* 7 *
0 2 4 6 8 10 12 14 16 15 20 22 24^ 26 28 30 32 L(mm)
individual length of Dreissenia Polimorpha
Fig. .11 Overqrowing of surface at Patndw Power Plant (Dreissenia Polimorpha)
C
20
-------
living in the waters of the Pacific Ocean, are resistant to high tempera-
tures and withstand, without serious harm, exposures of 38°C for one hour
(Mininmi, 1967).
Chemical methods have proven to be more effective for the control of
biological fouling. Chlorination is used both in once-through and recircu-
lating cooling systems. As chlorination is well discussed elsewhere, and
it is not a subject of this project, it is not discussed in this report.
An interesting method of controlling biological fouling inside cooling
water installations has been used at the Hartiques Ponteau Power Plant
(Magou, 1971). In this power plant, all closed pipes and channels have been
designed in a way which prevents the formation of areas of slow water move-
ment; it was assumed that water velocities above 2.0 m/s would inhibit
biological growth. The surfaces of the .water channels have been covered with
a toxic lining. Other countries also pay attention to the dependence of the
biological fouling on water velocity. The safe flow rate may be different
in any given case, dependent on the requirements for growth of organisms
covering the intake surface. In Bulgaria, for example, it has been assumed
that the rate of 2.0 m/s protects surfaces against fouling, whereas in the
USSR the safe rate has been assumed to be 3.3 m/s.
1.4 Control of Chemical Impurities
The control of chemical impurities is relatively easy in closed cycle
systems where make-up water may be treated chemically. However, in once-
through cooling systems, such treatment is practically impossible. It seems
that at present the only available method for control of chemical impurities
in oncethrough cooling systems is the use of CEPI devices installed on en-
dangered pipe. The CEPI apparatus is composed of a cylindrical body with
strong magnets inside. Chemical impurities flowing through a strong electro-
magnetic field lose their ability to form macrocrystals. The crystals separ-
ated from the water flowing through the electromagnetic field disintegrate
forming a suspension in the form of soft sludge or slime which is carried
away with the water. The action of the CEPI apparatus has a purely physical
character and is not connected with any chemical reaction. The chemical
composition of water remains unchanged, and its hardness is not reduced.
The duration of the magnetic induction effect, i.e. the period in which
the magnetically caused potential change prevents the formation of scale, is
approximately 3 days. This means that in once-through systems the CEPI °
apparatus has to be installed only in one place, while in closed systems the
CEPI units should be installed both in make-up water and in cooling water.
The CEPI units may be installed in water of a salinity lower than
3000 mg/1, and in systems where the thermal load does not exceed 25,000 kcal/h.
CEPI units have been used in industrial installations since 1945.
Up till now, over 100,000 units of various sizes have been manufactured.
Units produced in quantity have a maximum capacity of 8000 rrr/h. For once-
through cooling systems, this capacity is too low and would require the instal-
lation of a special set of CEPI units or the construction of special units of
high efficiency. The details of construction and operation 'of these units are
protected by Vermeiren's patent. CEPI equipment is manufactured by S.A. Euprex-
Antwerpia, a Belgian enterprise..
21
-------
1.5 METHODS OF CLEANING CONDENSERS
1.5.1 Mechanical Removal of Deposits
The most common mechanical method of protecting the internal surface of
condenser tubes against the formation of deposits is the continuous passage
of elastic rubber balls of a diameter larger than the diameter of the condenser
tubes. The system consists of devices for collecting the balls from the con-
denser outlet and sending them to the inlet chamber of the condenser.
Two types of balls are usually used: smooth balls and balls with an
abrasive surface. However, both these types of balls have a number of draw-
backs. This is caused by the nature of the sediments precipitating in the
tubes. These sediments usually have a non-homogeneous thickness and chemical
chemical composition, which results in non-homogeneous hardness and adhesion
to the tube walls. In such cases, the use of balls with an abrasive surface
can cause selective local abrasion of the condenser protective layer. In
extreme cases, this can lead to leakage of tubes, especially those with
surface deformations.
On the other hand, spongy balls, because of their highly developed
soft surface, quickly become abraded and their dimensions are reduced, caus-
ing the need of frequent replacement. The high elasticity of spongy balls
also requires the installation of complex screens catching the balls after
the condenser in order to return them to the cycle.
To eliminate these drawbacks, a new technology of balls production
has been developed in Poland and has been used at the Skawina plant and other
facilities. The balls are made of a spongy mass, permeable to water and
characterized by a rigid and rough surface formed in special patterns. This
facilitates delicate and effective abrasion of sediments from the tubes sur-
face, without any damage to the condenser tubes. Initial experiments show
that these balls fully prevent deposits from accumulating on the tube sur-
face and reduce chemical scaling to a high degree. It is believed that the
use of balls will reduce the necessity of chemical cleaning of condensers to
only once every three or four years. The installation of the system for con-
tinuous condenser cleaning by means of rubber balls can also reduce the
temperature of the steam-condensate by several degrees centigrade.
1.5.2 Chemical Cleaning of Condensers
Chemical cleaning of condensers aims at the removal of deposits and for-
mation on internal tube surfaces or protective layers, preventing corrosion
and precipitation of deposits. Because of the use of compounds that are harm-
ful to the environment, chemical cleaning of condensers is usually performed
only in closed system cleaning installations. The frequency of cleaning de-
pends on the rate of accumulation of deposits. In most cases, such cleaning
is performed once a year, at the start of normal unit maintenance. If systems
of cleaning by means of balls are in use, chemical cleaning may be limited to
only once every 2 or even 3 years. If water is strongly contaminated, clean-
ing may then be necessary twice a year. The total time for cleaning amounts
to 20 - 24 hours. The effect of chemical cleaning is presented in Fig. 13.
Although this method effectively removes mineral deposits, it causes
corrosion of the condensers by dezincification of brass. This fault was
eliminated by the introduction of a nitrogen shield. The method consisted
of displacement of air by nitrogen introduced under pressure (Fig. 14).
22
-------
a)
b)
17
16
o15
' 14
a 13
'= 12
S 9
If
Chemical
cleaning
xi xn i n m iv v vi vnvnrxx xi xn xi xii i n ui iv v vi viivn ixxxi x»
Months
Fig, 13. Effects of cleaning of -the 55MW condenser produced
by Siemens Comp.
_2
)t
i.
Rinse
waier
Je
-**•
fflfl
2 13
T
Fig. 14. Instatlaiton for -fhe rusted pipes of the condenser
chemical cleaning
1-condenser; 2 - circulating pump; 3-acid cylinder;
4-tank; 5-outlet pipelines; 6-nrtrogen cylinder
23
-------
The oxygen-free atmosphere significantly limits the process of corrosion
and increases the effectiveness of cleaning.
The next development in the cleaning of condensers involves the use of
fatty acids for cleaning. For cleaning, an addition of fatty acids with the
trade name of "Kowod" is used. The amount of the acid by weight depends on
the quantity and quality of the sediments on the tubes. Small amounts of
hydrochloric acid, glucose and hydrazine are added to the acid as agents which
heighten the effect of cleaning and reduce the corrosive action of the
solution (Jakubik, Maciejewski 1976). Neutralization is achieved by using a
diluted solution of sodium carbonate and phosphate. An aqueous solution con-
taining H3 803, KMntty and FeSCty is used to coat the surface. In Polish power
plants, the common practice of cleaning the condensers by this method ensures
good cleaning and high smoothness of the cleaned condenser surfaces; thus,
longer periods occur between cleaning operations.
As "Kowod" is a product produced on a small scale, another chemical pro-
duct "Emulkator" has been introduced for industrial application. Chemical
cleaning of the condenser tubes by means of "Emulkator" is similar to that in
the case of "Kowod".
Some types of sediments and impurities require additional treatment.
In the case of compacted sediments with a low level of calcium carbonate,
chemical cleaning must be preceded by thermal treatment (heating to 55-60°).
Because of differential linear expansion of the metal and sediments, the heat-
ing leads to the cracking and loosening of the sediments, and therefore
facilitates the penetration of the acid. If organic substances or particles
of coal and dust are present on the surface of mineral deposits, then the
tubes should be cleaned by a hydraulic method prior to chemical cleaning.
If the surfaces of the condenser tubes are contaminated with oil or
other petroleum derivatives, the tubes should be washed first with a warm
solution of sodium phosphate and carbonate with the addition of detergents
such as Sulfapol or Alfenol, with simultaneous hydromechanical cleaning of
tubes using solution. After such preliminary preparation, chemical cleaning
is performed. In some cases, the cleaning cycle will need to be repeated
several times.
24
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2. IMPACT OF OPEN AND CLOSED COOLING SYSTEMS ON SURFACE WATER QUALITY
The impacts of the operation of a steam power plant on surface water quality
may be divided into two groups:
1. Impacts other than those associated with cooling systems
2. Impacts associated with cooling systems
The first group of problems are a result of faulty operation and maintenance
or shortcomings in design and construction, for example:
- lack of proper protection against discharges of oil and grease
- improper design of sewerage systems and sewage treatment systems
- lack of equipment for treatment of toxic compounds arising from
the processes within the power plant
This group of problems may also include changes caused by power plant con-
struction and ash storage. In Polish experience, drainage at the construction
area results in uniform decreases of groundwater level, sometimes reaching
several centimeters and covering an area of a few square kilometers. After
construction is finished, the groundwater may need to be kept at a lower level
by pumping.
Changes of the hydrogeological regime in the area of the ash pond are
caused by infiltration of runoff waters into the earth. Since these waters
may include various harmful or toxic compounds which are leached from the ash,
the situation requires careful analysis. The problem is particularly important
if the ashpond is located near groundwater or surface water used for public
water supply.
The second group of problems include those mainly connected with cooling
system operation. Previously, much attention has been placed on'thermal prob-
lems connected with open cooling system operation, particularly on ecological
changes. Lately, more attention has been given to the impact of cooling system
operation on surface water quality.
Open and closed cooling systems have somewhat different problems. Sources
of water pollution from open cooling systems can be: corrosion, chlorination,
and chemical compounds used for condenser cleaning. Closed cooling systems
have various additional sources:
- Concentration of cooling water compounds caused by evaporation
in cooling towers
- water treatment for cooling purposes
- protection against precipitation
- use of corrosion inhibitors
- use of special means of protection against growth of water
organisms in cooling system installations
- wash-out of pollutants from the air by cooling towers
Concentration of compounds found in cooling water, blowdown water, and sew-
age are usually low; however, even these concentrations of heavy metals and toxic
compounds can be dangerous in the environment. Heavy metals such as Hg, Zn,
and Cr accumulate in sediments and aquatic organisms. Bioaccumulation can lead
to toxic concentrations in higher trophic levels.
This discussion describes previous Polish research and the results of
25
-------
research carried out for the purpose of this report. Fig. 1 presents the location
of the Polish power plants th-at were investigated.
2.1 Open Cooling Systems
Broad research on water quality in open cooling systems and. the impact of
steam power plants with open cooling systems on surface water quality has been
carried out in France. Measurements were made in 1964 at the Vaire-sur-Marne
power plant. The results of those measurements showed that, except for some
changes in nitrite content, the power plant had little effect on water quality.
2.1.1 Discussion of Project Results for Open Cooling Systems
To evaluate the changes in cooling water quality at local power plants with
open cooling systems, results of studies carried out by the Institute of Meteor-
ology and Water Management (IMWM) between 1972 and 1977 at the Kozienice, Stalowa
Wola, Dolna Odra, and Ostroleka power plants are used (9,10,11,12,13). Measure-
ments at the Gdansk, Rybnik and Skawina power plants were carried out during the
1975-77 period (14,15,16,17,18) and continued in 1978-79 by the IMWM Water
Management Division (WMD). Samples were taken considering the transport
time of cooling water through the cooling system.
In Tables 3 and 4 a comparison of frequency of occurrence of positive and
negative differences between intake and discharge quality is made. A plus sign
indicates the concentration was higher at the discharge than at the intake.
The analysis of basic parameters of cooling water quality indicates that
changes occur mainly for nitrogen compounds:
- The content of nitrate compounds in cooling water does not sig-
nificantly change except for the Kozienice power plant, where the
increase of nitrate concentration was observed in 22 of 39 samples
taken.
- Nitrite concentration appears to increase as a result of passage
through the cooling system. In 33 of 41 samples taken at the Kozie-
nice power plant, nitrite concentration increased at the point of
discharge. This trend of increase in nitrite concentration was also
indicated by measurements taken at the Dolna Odra and Ostroleka power
plants. Analyses of water at the Gdansk power plant show a decrease
of nitrite content at the discharge in 10 of 12 samples taken.
*
- Decrease of ammonia nitrogen content was observed at the Rybnik and
Gdansk power plants; however, at the Stalowa Wola and Ostroleka power
plants, the content of ammonia nitrogen in the cooling water increased.
- A small increase of organic nitrogen content was observed at the
Stalowa Wola and Ostroleka power plants, but measurements taken at
the Kozienice power plant do not show this phenomena.
- In 5 of 6 power plants under investigation, a small decrease of
is observed in water after passage through the cooling system.
- At the Gdansk and Rybnik power plants an increase of COD was observed.
26
-------
ro
Fig.JS Location map for investigated
power plants
-------
1'able 3 . Comparison of changes of cooling water quality chemistry between intake
and discharge in Polish power plants with open cooling systems
ro
oo
Power Plant
Indicator
Kozienice
No. of
samp.
Reaction (pH) 40
BOD 41
COD 41
Ammoni a 41
Nitrite 41
Nitrate 39
Org. nitrogen 41
Orthophosphates 41
Org. phosphates 40
Dissolved solids
Suspended solids
Conductivity 41
Period frequen-
cy of research
Change
- 1 +
Stalowa Wola
No. of
samp.
13 15 5
24 16 5
20 21 5
18 18 5
5 33 5
16 22 5
24 17 5
22 17 5
20 20
13 18 5
Peb.73-Deo.75
twice a month
Change
- I*
Dolna Odra
Wo. of
samp.
311 14
4 1 14
2 3 14
1 4 9
32 14
4 1 14
0 5
40 14
14
14
1 2
Oct. 75-July 76
every second
month
Change
- | +
Ostrol§ka
No. of
samp.
52 8
85 8
84 8
43 8
1 8 8
58 8
8
6 6
8
7 5
7 6
8
Apr.75-0ct.77
every second
month
Change
- I +
1 4
5 3
2 5
2 5
2 5
2 5
3 2
Aug.72-0ct.77
once- a month
Luring the day of sampling, 10 1 samples were taken once a day. Ranges of changes in
concentration were several times higher than the accuracy and sensitivity of measur-
ments.
-------
Table ^ Comparison of changes of cooling water quality chemistry
between intake and discharges in Polish power plants with open cooling systems
ro
Power plant Gdansk Rybnik
Indicator a«mo
pH 12
BOD 12
COD 12
Ammonia 4
Nitrite 12 »
'Nitrate 4
Org. Nitrogen 12
Sulphates 12
Chlorides 12
Phospha'tes
Alkalinity 11
Hardness 12
Dissolved solids 12
Suspended solids 12
Conductivity
Period and frequen- Jan//8
Change No. of
48 9
10 2 9
48 9
3 1 9
10 2 9
3 1 9
53 9
57 9
57 9
7
47 9
66 9
57 9
47 8
4
- June 78 March
Change
- I +
Skawina
No. of Change
4 5 10 1 5
3 6,
2 6 10 6 4
80 926
45 7 4-3
45 954
2 1
54 10 82
3 4 10 6 4
3 3 10 2 8
32 905
2 6 10 3 6
5 4
2 5
22 10 55
78 - Nov. 78
cy of research twice a month, once a month,
metals every 3 days metals 5
x a month
March 78 - Dec. 78
once a month, metals:
S eri es I March-Aug .
every 2 days, Series II
monthly Sept. -Dec.
every 30 minutes
-------
These changes in nitrogen compound concentration may be an artifact of the
sensitivity of the tests. The range of changes in concentration of water quali-
ty parameters is higher in all cases than the range of the accuracy of measure-
ments; however, no trend of the changes in water quality parameter concentration
is evident.
Metals
To learn more of the impact of open cooling systems on changes in cooling
water chemical composition, analyses of intake and discharge water were sup-
plemented by analyses of heavy metal concentrations at the Gdansk, Rybnik and
Skawina power plants. The Water Management Division performed analyses of Fe,
Zn, Cu, Pb, Ni, and Cr. Changes in the concentrations of these metals during
passage through the cooling system would indicate corrosion or deposition.
Changes in the chemical form of the metals from chemically bound to more toxic
ionized forms could harm aquatic food chains. Tables 5a,b,c show the range of
metal concentrations in the intake and discharge water in the power plants
under investigation.
To determine the potential for corrosion products in the cooling water,
analyses of condenser materials were conducted. Condensers in Polish power
plants are constructed of 2 kinds of material: M-70 and MC-70. M-70 condensers
are used in older.power plants (Siekierki, Skawina, Miechowice, Gdansk). This
alloy contains 69-72 per cent copper, 0.07 per cent arsenic with the remainder
of zinc. MC-70 condensers are used in new power plants (Turbw, Lagisza, Rybnik).
MC-70 alloy consists of 69 to 71 per cent copper, 0.7 to 1.0 per cent tin, 0.02
per cent phosphorus, with the remainder of zinc.
During the research on metal concentrations in cooling water, it was ex-
pected that the main source of cooling water pollution would be corrosion. To
describe the impact of corrosion processes on the changes of cooling water qual-
ity, a comparison of positive and negative differences between intake and dis-
charge concentrations were compared for the metals under investigation (Table 6).
Increase in metal content was considered a positive difference. The analysis
of metal concentration changes in cooling water shows differences between facil-
ities and metals in the frequencies of occurrence of metal increases or decreases
in discharge water compared to intake water.
In the case of iron, an increase of concentration at the discharge was ob-
served at the Gdansk and Skawina power plants and a decrease in the case of the
Series II at the Skawina power plant. For copper analyses in all power plants
under investigation, there was a consistent increase of concentration at the
discharge compared to the intake. Like copper, increases of zinc content through
the cooling system were observed for almost all power plants under investigation.
Lead content in cooling water was observed to change slightly due to passing
through the cooling installations. In the case of chromium and nickel for both
plants under investigation (Gdansk and Rybnik), an increase of concentrations
of these metals in discharge water in comparison to intake water were observed.
Statistical Analysis
As shown by the results of the analyses, there is little consistency in
the relationships developed for the various metals. Because of this, additional
statistical analyses of the acquired data were conducted. Student's t test was
applied, since less than 120 data points were acquired. For the probability
level 0( = 0.9, differences between values of metals concentrations at the
intake and discharge were shown not to be statistically important. Apparent
30
-------
Table 5a. Range of metals concentration changes observed at the
Metal
Iron
Zinc
Copper
Chromium
Nickel
Gdansk
No. of
sampl es
56
37
56
54
44
Power Plant Cooling Water
Range of con-
centration at
the intake
0.15-1.5
0.0-0.1
0.0-0.05
0.001-0.014
0.0-0.006
Range of concen-
tration at the
di scharge
0.1-3.5
0.005-0.15
0.002-0.06
0.003-0.016
0.001-0.006
Table 5b. Range of metals concentration changes observed at the
Rybnik
Metal No. of
samples
Zi nc 36
Copper 39
Lead 40
Chromium 31
Nickel 41
Power Plant Cooling
Range of con-
centration at
the intake
0.04-0.2
0.008-0.035
0.001-0.014
0.0005-0.005
0.003-0.011
Water
Range of concen-
tration at the
discharge
0.04-0.2
0.01-0.04
0.001-0.019
0.0005-0.005
0.005-0.013
Table 5c.
Range of metals concentration changes observed at
the Skawina Power Plant Cooling Water
Metal
m.9/1
Iron
Zinc
Copper
Lead
Iron
Zinc
Copper
Lead
No. of
samples
92
88
77
80
96
94
87
94
Range of con-
centration at
the intake
Series I
0.17-1.8
0.08-0.72
0.001-0.016
0.007-0.07
Series II
0.7-2.1
0.1-0.8
0.002-0.015
0.006-0.06
Range of concen-
tration at the
discharge
0.21-2.3
0.08-0.97
0.0-0.016
0.0-0.08
0.7-2.2
0.1-0.9
0.001-0.017
0.007-0.06
31
-------
Table 6. Comparison of metals concentration changes between the intake and discharge
to
ro
r'ower Plant
Metal
Iron
Zinc
Copper
Lead
Chromium
Nickel
Gdansk
No. of
samp.
56
37
56
-
54
44
Change
+
43
34
43
-
46
33
-
12
3
8
-
4
2
Rybnik
No. of
samp*
—
36
39
40
31
41
Change
+
_
24
31
12
14
25
-
_
10
7
25
10
14
Skawina
serie) I
No. of
samp.
92
88
77
80
-
- -
Change
+
46
38
45
31
«
-
-
39
40
6
28
-
-
aerie? II
No. of
samp.
96
94
. 87
94
-
-
Change
•f
35
48
55
41
-
-
-
54
39
18
43
-
-
-------
differences between means for the short research series should be considered
to result in'large part from sampling or analytical error.
Summarizing the results of our research in power plants with open cooling
systems, one may say that no'Significant changes of basic parameters of cooling
water quality during permanent power plant operation have been determined. The
chemical quality of water discharged from open cooling systems depends on the
chemical quality of intake water. However, during cooling system cleaning, it
is expected that an increase of metal concentrations in water discharged from
the cooling system will occur.
Thus, the operation of open cooling systems has an effect on concentrations
of pollutants in cooling water which is too low to be observed given the large
values of water involved. The results tend to confirm the opinion normally held
that open cycle cooling systems contribute only trace amounts of metals to the
environment.
2.2 Impact of Closed Cooling Systems on Surface Water Quality
2.2.1. Discussion of Field Research Results
Studies to describe the impact of closed cooling systems on surface water
quality have been carried out by the Krakow and Gdansk Divisions of the Institute
of Meteorology and Water Management for the following power plants: Turow,
Lagisza, Laziska, and Miechowice. Analyses were made of wastewatewater manage-
ment for these plants. The water supply system for each cooling system is dis-
cussed below as well as the mass balance for pollutants discharged from the
plants.
Research at the Turow power plant was. carried out in 1975 and 1977 by the
Institute's Division in Wroclaw (Ref. 19, 20). The plant has an installed
capacity of 2000 MW and uses lignite. Make-up water is drawn primarily from
the Witka River. Periodically, part of the make-up water is taken from the
Nysa Luzycka River as indicated in Table 7. The cooling system consists of
9 cooling towers with a flow rate of 27,000 m^/h each with a cooling range of
9 degrees C. Research on water quality changes in the cooling system was
carried out from October to December, 1977. Analyses of mean daily samples
of cooling water were made. Results are presented in Table 8. Comparison of
make-up water drawn from the Witka River and the Nysa Luzycka River with water
discharged from the cooling towers shows that an increase of pollutant con-
centrations in the discharge is mainly due to evaporation. In the case of
nitrates, a significant increase of concentration is observed as a par-
tial result of the large decrease of nitrite content. This indicates a high
intensity of nitrification. Water discharged from cooling towers contains
several times more sulphur and sulphates. Also, the concentrations of TDS-TSS
in water discharged from the cooling system is significantly higher than in
the make-up water.
The Krakow Division of the Institute of Meteorology and Water Management
carried out a series of water and wastewater measurements in the Laziska power
plant. This power plant, originally constructed in 1918, had an installed
capacity of 1230 MW after reconstruction in 1973. The closed cooling system
of the power plant is equipped with 12 cooling towers of an approximate hy-
draulic output of 4,000, 6,000, 4 x 8,000, 2 x 17,000 and 4 x 30,000 m3/h.
33
-------
Sable .7 . Proportion of intake Water from the Hysa Luzycka in
the period of field studies
Period of field
studies
Oct. 26/27
Oct. 27/28
HOT. 16/17
Nov. 17/18
Nov. 29/30
Hov. 30/Dec. 1
Total make - up
water nr/ day
105 954
100 053
95 940'
99 360
68 622 .
'93 423
Intake water from
the Nysa Luzycka %
17,6
7.2
. 1.3
0.0
6.1
9.5
34
-------
Table 8. Results of cooling water chemical analyses performed,
from October to December,1977 at the Turow power plant
—
Indicator
Water flow nr/day
Reaction pH
Alkalinity oval/1
Hardness n
COD mg02/l
Ammonia mg/1
Nitrate "
Nitrite w
Organic nitrogen "
Phosphorus "
Total Sulphur • "
Sulphates "
Chlorides "
Silica " '
Iron Mg/1
Copper yHs/l
Zinc yU.g/1
Chromium yk g/1
Mercury ,/A g/1
Lead • /img/1
Nickel yt(mg/l
Dry residue mg/1
Total" dissolved solids mg/1
Total suspended solids mg/1
Witka
Intake
87.180
7.22
0.53
5.05
39.6
0.152
2.363
0.110
0.658
0.0433
53.12
51.85
19.15
14.28
346.7
12.8
60.5
2.0
3.80
28.0
53.0
213.7
197.3
16.3
wysa
Intake
8054.4
7.64
1.82
7.80
39.52
2.140
2.224
0.330
1.122
0.5306
85.76
84.12
41.4
16.38
814.0
15.8
65.6
6.2
0.44
29.2
26.8
380.4
327.6
52.8
Water in
cooling cycle
8.06
8.06
2.32
20.73
48.40
0.350
10.295
0.020
1.290
0.400
234.68
227.95
64.0
56.75
470.8
21,2
60.0
11.0
1.68
29.8 :
55.3
794.5
762.5
32
more sulphur and sulphates. Also the concentrations of TD5-ISo in
water discharged from the cooling system increases significantly
as compared to its amount in the make-up water.
35
-------
Table 9. Results of analyses of cooling water made on June 4,1975
at the Laziska Power Plant
Parameter
Reaction pH
BODe mg02/l
COD mgO^/l
Alkalinity mval/1
Hardness tt
Calcium mg/1
Magnesium B
Sodium "
Potasium "
Silica H
Iron K
Manganese "
Copper n
Zinc "
Lead "
Nickel "
Mercury "
Arsenic "
Chromium u
Cobalt "
Cadmium M
Vanadium "
Chlorides "
Sulphates "
Phosphates "
Ammonia M
Nitrite »
Nitrate - u
Organic nitrogen "
Phenols "
Cyanides "
Dry residue "
Dissolved solids "
Suspended solids "
Intake
8.1
3.8
29.6
1.9
9.75
101.5
65.5
100.0
8.5
' 8.0
0.05
1.54
0.007
0.074
0.002
0.0
0.0
0.0045
0.0
0.012
0.0031
0.032
36.9
100.1
0.0
0.0
0.0
0.081
0.85
0.016
0.004
810.0
810.0
0.0
Slowdown
8.7
2.4
11.0
2.7
14.6
144.3
89.7
175.0.
-
14.0
1.5
0.0
0.002
0.034
0.004
0.0
0.0
0.0065
0.0
0.016
0.004
0.038
124,0
1038.0
0.165
0.0
0.0
0.036
2.79
0.002
0.0013
2050.0
2032.0
18.0
Concentration
coefficient
.
-
1.50
1.42
1.50
1.75
-
1.75
-
-
0.20
0.46
2.00
-
~. •
1.44
-
1.33
1.20
1.10
3.36
2.54
-
-'
-
0.44
3.28
0.12
0.32
2.53
2.51
-
36
-------
To supply water lost from the power plant cooling system, decarbonized mine
water is used. Usage of make-up water for the cooling system ranges from
2,200 to 2,250 m^/h. Measurement of make-up water carried out on June 4, 1975
included the analyses of the chemical composition of mine water added to the
cooling system and water discharged from cooling towers. Results of the
analyses are presented in Table 9. ,
Mine water contains quite a lot of salt with sulphates and chlorides in
the largest concentrations. Slowdown water discharged from the cooling towers
contains concentrations of sulphates and chlorides which are three times
higher due to evaporation. Relatively higher concentration of organic nitro-
gen are observed which could be a result of microorganisms present in the
cooling water. Attention should be given to zinc and copper concentration -
decreases. This phenomenon has not yet been explained.
To investigate the changes of water quality during its passage through
the cooling system, field research was carried out for the Turpw, Drzymala,
and Lagisza power plants by the Institute of Environmental Engineering
at Wroclaw Technical University during the period from August, 1978 to
April, 1979. The characteristics of the Turow power plant in Bogatynia
and its water management were presented above. The Drzymala power plant in
Miechowice and the Lagisza power plant use lignite. The amount of sulphur
in the lignite used in the Drzymala power plant in Miechowice is about
0.9 per cent, and in the Lagisza power plant it ranges from 1 to 1.5 per
cent. The Miechowice power plant of 220 MW installed capacity (4 units
of 55 MW each) is supplied with make-up water from municipal sources. Pre-
liminary preparation of water is made before it gets to the cooling system.
Twenty five percent of the water is decarbonized with lime in a settling
basin and passed through mechanical filters. Seventy five percent of the
water is neutralized with hydrochloric acid and the addition of blowdown
water containing phosphate from boilers. The closed cooling system of the
Miechowice power plant is equipped with 4 wooden cooling towers.
The Lagisza power plant (7 units of 120 MW each) is supplied with make-
up water from the Czarna Przemsza intake in the amount of 27,000 m3 per day.
The make-up water for the cooling system is prepared by decarbonization with
lime and coagulation with ferrous sulphate - FeS04. The closed cooling system
of the Lagisza power plant is equipped with 6 hyperbolic reinforced concrete
cooling towers.
In the three power plants under investigation, water samples were taken
once a day during 3 consecutive days of each month (27 samples). Analyses
were made for make-up water and for water circulating in the cooling system.
Results of the cooling water analyses are presented in Table 10. For each
indicator of water quality presented in Table 10, a mean concentration co-
efficient (ratio of particular compound content in circulating water to
its content in make-up water) was calculated, representing the degree of
concentration of make-up compounds in the closed cooling systems. In all
cooling systems under investigation, concentration coefficients calculated
for heavy metals differ significantly from concentration coefficients calcu-
lated for other indicators. The biggest differences were observed in the
Turow power plant for mercury (calculated concentration coefficients for
chlorides - 1.3, for mercury - 2.4). Smaller, but significant differences
are also noticed for iron, zinc, lead, molybdenum in the Turow power plant,
for nickel in the Miechowice and Lagisza power plants, for manganese in all
power plants, and for mercury in the Miechowice power plant.
37
-------
Table 10. Results of cooling water chemical analyses carried out by the Water Management Division
of IMVM at the Turow, Miechowice and Lagisza power plants
Indicator
Heaction
PH
Alkalinity
mval/1
Hardness
germ. deg.
Calcium
mg/1
Magnesium,,
Sodium "
Potasium M
Airf6nia «
Nitrite "
Nitrate "
Sulphates"
Chlorides"
Iron "
Zinc "
Copper "
Lead "
Nickel "
Manganese11
Mercury M
Molybdebum"
Dissolved
solids M
Suspended
solids »
Turow
Make-up
water
7.6
1.96
39.18
68.9
23.5
79.1
14.0
0.043
0.0138
6.12
2003
66.1 '
0.408
0.039
0.011
0.014
0.008
0.051
0.0
0.004
787.8
153.1
Cooling
v/ater
7.3
1.89
34.60 .
81.0
25.7
93.5
15.4
0.044
0.0144
8.5
235.6
85.7
0.651
0.066
0.017
0.025
0.012
0.090
0.0
0.008
756.6
136.9
Calcul.
concent r.
coeff.
_
—
0.83
1.2
1.1
1.2
1.1
1.02
1.04
1.4
1.2
1.3
1.6
1.7
1.5
1.8
1.4
1.7
2.4
1.9
0.96
0.90
Miechowice
Make-up
water
7.2
1.89
56.83
134.8
29.6
71.9
13.7
0.30
0.0167
5.63
262.7
80.9
0.375
0.031
0.017
0.021
0.014
0.046
0.0
0.011
874.3
255.4
Cooling
water
7.1
1.89
59.4
148.7
36.1
86.1
16.9
0.033
0.0184
7.0
348.9
111.9
0.493
0.040
0.024
0.030
0.021
0.070
0.0
0.015
862.0
260.0
Calcul.
c on cent r.
coeff.
_
_
1.05
1.1
1.2
1.2
1.2
1.1
1.1
1.2
1.3
1.4
1.3
1.3
1.4
1.4
1.5
1.5
1.5
1.3
0.99
1.02
Lagisza
Make-up
water
7.5
2.06 '
60.0
141.6
26.4
55.9
14.8
0.038
0.0193
3.19
248.1
79.4
0.483
0.038
0.020
0.030
0.018
0.041
0.0
0.016
854.9
169.6
Cooling
water
7.4
1.97
54.35
169.1
34.6
71.0
17.4
0.042
0.0202
3.71
310.0
87.5
0.565
0.050
0.028
0.039
0.028
0.061
0.0
0.021
820.1
165.2
Calcul.
concent r.
coeff.
• •—
_
0.91
1.2
1.4
1.3
1.2
1.1
1.05
1.2
1.2
1.1
1.2
1.3
1.4
1.3
1.6
1.5
1.4
1.3
0.96
0,97
to
CO
-------
The higher concentration coefficient for heavy metals is not only a result
of evaporation but also suggests the possibility of the contribution of metals
from other pollution sources, e.g. corrosion and wash out by water from the air
in cooling towers. The issue of wash out of pollutants by water from the air
in cooling towers is discussed in the next section of this report.
Differences of the concentration coefficients of various forms of nitrogen
may indicate intensive nitrification. In the cooling waters of the investi-
gated closed systems, the concentration coefficient of nitrites is higher than
the concentration coefficients for ammonia and nitrites. Concentration coeff-
icients equal to or less than 1 for dissolved and suspended substances are the
result of precipitation in the cooling tower basin.
2.2.2 Evaluation of the Pollutant Load Washed Out of the Air
The load of pollutants washed from the air can be defined by the following
dependency:
U = Q Ao /{, • Xp
where:
U - the load of pollutants washed from the air mg/s
Q - cooling system flow rate (m 3/s)
"Xo - volumetric ventilation coefficient, volume of air passi-ng through
the cooling tower /m3 of circulating water. On the basis of theoret-
ical work by the Polish Energy Institute (13), it was calculated that
the average value of the coefficient is equal to 430 m3 of air per
m3 of circulating water
/^ - rate of wash out from the air (%)
Xp - Concentration of pollutants in the air entering the cooling tower
(rag/ra3)
Wash out of pollutants from the air is a relatively new problem which
has not been analyzed previously with respect to cooling towers. The follow-
ing are the first Polish results as carried out by the Institute of Environ-
mental Protection of the Technical University of Wroclaw. The field tests
were carried out from November 1977 till April 1979 on the cooling towers of
the Turow, Lagisza and Miechowice power plants.
A total of 130 measurements were made on the concentrations of pollutants
in the air flowing through the cooling tower. The monitoring locations in the
air were located at the inlet to the cooling tower and above the sprayers. The
tests were mainly aimed at defining the wash-out of metals (iron, zinc, copper,
nickel, manganese, mercury), as well as sulphur dioxide and nitric oxides. The
results of the field tests are given in Tables 11 and 12. The tests performed
show that an average of 20% of the examined pollutants contained in the air pass
into the cooling water. Calculations show that in the cooling tower of the
Turow power plant which has a daily cooling capacity of 27,000 m3/h, the aver-
age daily loss of air pollutants to the cooling water is: 3.9 kg sulphur dioxide,
10,4 kg nitric oxides, 4.7 kg iron, 16.8 g zinc, 26.9 g copper, 33.7 g lead,
9.1 g nickel, 11 g manganese, 5.7 g mercury. At the Lagisza power plant, 6
series of detailed examinations were made to measure the change of air pollution
adjacent to the cooling tower up to 4 m high and the change of pollution in water
flowing from the sprayers. These tests showed that the concentrations of most
pollutants in the air increase with height. This is especially true with regard
39
-------
Table II. Average values of pollutant concentration in the air passing through the cooling
tower /measured outside the cooling tower at the inlet/
Power
plant
Turow
Miechowlce
LagLsza
Laziska
Time oi
sampling
/hours/
10-13
13-16
16-22
22-10
10T13
13-16
16-22
22-10
10-13
13-16
16-22
22-10
10-13
13-16
16-22
22-10
Gases
SO
fc-2
mg/nr
0.102
0.069
0.051
0.027
0.172
0.112
0.068
0.046
0.210
0.099
0.084
0.071
0.161
0.091
0.086
0.071
WO
X3
mg/nr
0.449
0.264
0.234
0.147
0.608
0.408
0.264
0.208
0.391
0.266
0.160
0.106
0.399
0.209
0.166
0.138
Metals
Fe
mg/nr
x 10~2
8.48
7.73
6.99
6.01
7.283
6.41
5.58
4.60
7.653
7.194
7.050
6.022
8.12
7.48
5.96
3.81
Zn
mg/nr
x 10~A
3.02
1.59
1.02
0.755
2.177
1.494
1.005
0.811
2.442
1.942
1.707
1.089
2.41
2.06
1.41
1.03
Cu
mg/nr5
x 10~4
5.05
3.20
2.04
1.26
1.908
1.587
1.164
0.962
1.873
1.518
1.457
1.048
2.03
1.46
0.961
0.812
Pb'
mg/nr
x 10~4
5.88
3.94
2.89
2.37
5.888
5.217
3.99
3.20
6.092
5.900
4.712
3.652
6.05
5.06
4.52
3.82
Ni_
mg/nr
x 10~4
2.68
1.047
0.846
0.745
2.124
1.773
1.370
1.196
2.413
1.954
1.787
1.313
2.45
1.61
1.18
0.969
Mn '
5
mg/nr
x 10~4
2.22
10.17
8.32
6.70
8.143
6.690
6.013
5.43
8.602
7.74
7.802
6.730
8.86
7.12
5.28
5.01
Hg
mg/m
x 10~6
9.9
7.81
7.10
5.06
6.623
5.987
4.927
4.908
6.978
6.088
5.343
4.848
7.22
5.12
4.82
4.12
pi
o
-------
Table 12 . Degree of pollutants wash-out from the air by water in cooling
towers of the Turow, Hiechowice, Lagisza anrt Laziska oower plants
% Reduction 'in Air Pollutant Concentration Aoove tne'Sprays as Compared with tjie Inlet
Power plant
Bogatynia
Miechowice
Lagisza
Laziska
min
mean
max
mirr,
mean
max.
min
mean
•max
min
mean
max
Gases
so2
0.00
18,19
37.50
4.00
18.67,
31.20
3.80
20.42
37.00
' 7.00
8.15 '
8.80
NOX
0.00
19.94
60.80
5.10
18.07
30.10
0.80
17.49
31.00
10.80
13.95
18.80
•• • — i
Metals
Fe
0.40
18.13
13.00
3.00
20.24
40,00 •
2.90
17.78
30.00
6.00
9.15
13.70
Zn
1.00
20.49-
36.00
3.50
18.70 ,
37.00
1.80
19.25
31.00
5.40
10.10
15.60
Cu
0.10
20.50
47.00
4.20
17.67
33.00
6.60
18.33
31.00
6.40
7.75
10.30
Pb
3.20
22.01
42.00
3.90
20.53 '
34.70
3.40
19.91
30.00
7.50 '
12.40
18.30
fll
2.00
16.69
41.00
1.60
20.70 '
44.00
5.00
16.26
27.00
8.00 '
10.82
14.40
Mn
3.00
19.94
37.00
3.60
25.40
76.00
3.20
20.29
35.00
7.80
9.98
12.60
Hg
4.80
22.02
48.00
4.00
23.11
43.00
5.10
17.57
30.00
5.80
10.42
15.60
-------
to such metals as: Ni, Pb, Cu, Zn for which concentration grew with height in
every instance. At 4 m the increase of concentration of the above metals in
mg/nP x 10"* above ground level varied within the limits: Ni: 5-11.2%, Pb:
2.6 - 11.5%, Cu: 3.7 - 8.8%, Zn: 6.0 - 18.0%. With regard to the remaining
pollutants, this tendency is also indicated, although it was not as prominent
in each of the series of measurements. The change in quality of water flowing
from the sprayer was examined at sampling points located at 1, 3, 5 and 7 m.
above the water surface in the cooling tower basin. The change of quality of
water at these elevations is shown in Table 13. The results show the following
increases of pollutants in water between the 7m and 1m levels: Chlorides
,C1- - 17%, total nitrogen - 11%, sulphates - 18.5%, calcium compounds - 35.2%,
manganese compounds - 28.9%, phosphorus compounds - 16.2%, iron Fe 31.2%,
copper Cu - 22.8%, zinc Zn - 17.6%, chromium Cr - 23.7%, mercury Hg -43.1%,
Nickel Ni - 16.4%, cadmium Cd 44.0%, cobalt Co - 17.4%, vanadium V - 20.6%.
In spite of the considerable increase of pollutants contained in water,
flowing from the sprayer system in the cooling tower, no comparable permanent
increase of such pollutants was observed in the water continuously circulating
in the cooling system. Chemical laboratory tests made to clarify this process
showed that most of the washed out compounds go through further transformations
in the cooling water, resulting from the increase in pH of the water and result-
ing precipitation of residues. The contents of most of the compounds washed
out from the air in the cooling water, consisting mainly of metals, are largely
dependent on the reaction rate and the temperature of the water. In the con-
ditions existing in the cooling tower basin, most of the pollutants washed out
from the air are precipitated.
42
-------
'fable 13 . The change of quality of water at the cooling tower
Pollutants
Chloridea uig Cl~7 1
Total nitrogen mg M/l
Sulphates mg S/l
Calcium compounds mg/1
Manganese compounds mg/1
Phosphorus compounds mg
Iron ;ug Pe/1
Copper jug Cu/1 „
Zinc jug Zn/1
Chromium ,ug Cr/1
Mercury jug Hg/1
Mickel jug M/l
Cadmium ,ug Cd/1
Cobalt ;ug Co/1
Vanadium ;ug V/l
Water flowing from the sprayer
Height above the water surface
in the cooling tower basin
/m/
7 5
87.8 94.8
1.842 1.878
308 326
79.5 88.5
40.2 43.7
0.185 0.195
254 274
27.0 28.7
41.5 43.0
2.02 2.23
0.058 0.065
31.5 33.0
32.2 34.0
28.7 30.8
16.0 17.2
3 I 1
97*0 102.7
1.936 2.042
349 365
97.5 107.5
45.7 51.8
0.203 0.215
309 334
30.5 33.6
45.6 48.8
2.47 2.50
0.077 0.083
34.8 36.7
36.7 46.3
33.0 33.7
17.7 19.3
Water in the cooling
tower basin
deep below the water sur-
face in the cooling tower
basin /m/
0.0 0.7
103.7 101.8
2.185 2.241
369 356
109.3 109.5
53.4 50.0
0.228 0.233
342 356
34.2 37.7
50,5 59.3
2.60 2.70
0.088 0.096
37.5 39.2
46.6 49.0
33.7 32.8
20.2 20.8
1.5
104.2
2.827
347
114.2
48.8
0.250
361
40.0
60.3
2.80
0.105
40.2
49.5
34.3
22.3
-p.
GO
-------
3. Make-up Water Demand and Water Loss in Closed Cycle Cooling Systems
Important considerations in the evaluation of cooling systems are the
seasonal variation of make-up water demand and the dependence of total make-
up water demand and water loss on plant efficiency. Project JB-5-537-4
explored the following topics:
- The theoretical basis for the calculation of evaporation loss
- A comparison of theoretical values of evaporation loss with values ob-
tained from field studies and with values presented by other authors
- An analysis of different elements of make-up water balance
- An analysis of the total water demand of steam power plants for closed
cooling system use as well as for other purposes
3.1 Make-up Water Demand Analysis for Closed Cycle Cooling Systems
The amount of make-up water needed to compensate for losses in closed
cycle cooling systems is defined by:
Qm • Qe + Qd + Qb + Qp (1)
where:
Qe = amount of water lost by evaporation
Qd = amount of water lost by drift
Qb = amount of water lost by blowdown
Qp = amount of water needed by the power plant water treatment system
The separate components of the balance depend on many varying techni-
cal and natural factors.
3.2 Evaporation Losses in Cooling Towers
The calculation of evaporation losses assume that the whole volume of
air going up through the cooling towers will be saturated with water vapor.
Zembaty and Radwanski (1978), on the basis of the theoretical calculations,
report that the share of evaporation in total heat loss amounts to:
- up to 38% for very low temperature
- up to 62% in January
- up to 70% in October and April
- up to 81% in July
Utilizing the theoretical basis presented by Zembaty and Radwanski
-(1978), an additional calculation of the change of evaporation losses
has been made as a function of the following parameters:
- heat discharge load of cooling tower: A = ^» At (Kcal/s)
- surface of horizontal cross-section of spray system: F (m2)
- effective height of the cooling tower He (m)
Calculations were made for the following assumed cooling system speci-
fications:
- air temperature ta = 15°C /
- relative humidity of air: ^ = 70%
- cooling water flow: Q - 8000 1/s
- temperature rise through the condenser t = 8.35°C
44
-------
The results of calculations given in Table 1 show that the fraction of
heat lost through evaporation depends on the heat load of the cooling tower
and on atmospheric conditions. Atmospheric conditions determine the share of
total heat lost during the evaporation of water. Under the assumed atmos-
pheric conditions, the coefficients defining the share of heat lost by
evaporation amounts to approximately 72% and does not depend on changes of
other parameters. This value corresponds with the results of research per-
formed in the Neurath C Power Plant (Baer et al. 1974, 1979) which are dis-
cussed later in this report.
Table 14
Evaporation Losses in a Cooling Tower Depending on the Heat Load
Sprayer Surface and the Cooling Tower Height
Coefficients
of change of
basic quanti- F
ties
Surface of
the Sprayer
2 M
Q « 1.0 4,415
Q « 0.75 4,415
Q = 0.5 4,415
Fz= 1.25 5,500
Fz= 1.0 4,415
Fz= 0.75 3,300
He= 2.0 . 4,415
He= 1.5 4,415
He= 1.0 4,415
He= 0.5 4,415
Effective
height of
the cooling
tower HQ (m)
100
100
100
100
100
100
200
150
100
50
Heat load
of cooling
tower (A)
Kcal/s
75,000
56,250
37,500
75,000
75,000
75,000
75,000
75,000
75,000
75,000
Fraction of
Qe heat lost
kg/s during
evaporation
93.6 72.5
69.5 71.7
45.8 70.9
92.2 71.4
93.5 72.3
93.7 72.5
93.7 72.5
93.7 72.5
93.5 72.5
94.1 72.6
The results of theoretical calculations were compared with the results of
a one year field study of water balance in the closed cooling system of Power
plant No. 7 (see Table 15) which was the subject of detailed analysis. Plant
No. 7 consists of four generating units of approximately 55 MW capacity each,
giving a total capacity of 220 MW. The cooling system consists of 4 steel
structure natural draft cooling towers with asbestos fill, each receiving
a 10,000 m3/h water load. The cross sectional surface of each cooling tower
base is 1,256 m2 and that of the spray system is 1,190 m2. The height of the
cooling towers is H = 45 m, and height of the spray system is H2 = 5.0 m;
the air inlet is at Hg = 2.8 m. City water is supplied to the cooling system.
As noted in Table 2, some of the make-up water is decarbonized with lime and
neutralized with hydrochloric acid. The concentration coefficient K is on the
order of 6.
The daily water consumption of the power plant was measured on a water-
meter while the quantity of water for cooling purposes was established from
the changes of water level in the cooling tower basin and changes of water
45
-------
Table 15
Balance
Data
1
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
July
Aug
Sept
of daily water demand
Power Plant Make-up
m3
fresh
water
2
92,371
117,435
141,420
167,902
129,042
158,932
209,600
252,907
253,463
291,818
280,698
242,615
decarbo-
nized
3
77,656
75,280
76,152
78,148
138,981
106,548
62,680
62,275
42,675
-
-
33,559
for the
Water
total
4
170,027
192,280
217,572
246,050
268,023
265,480
272,280
316,182
296,138
291,818
280,698
276,174
cooling system
in Steam Power Plant Ho 7
Cooling System Balance
m^
blow-
down
5
1304
1259
1025
1392
1008
1146
1050
1134
1195
1131
1066
1053
sludge
disch-
arge
6
2702
1276
2800
6006
1554
2600
900
21,300
34,000
52,500
25,500
16,600
drift
7
12,484
16,563
18,737
21,308
22,616
13,344
24,141
25,339
20,193
19,575
19,895
29,981
evapo-
ration
8
153,537
173,617
196,010
217,350
242,845
239,390
246,180
268,409
240,750
217,612
224,237
237,540
Heat dis-
charge to
the cool-
ing sys -
tern G cal
9
109,235
137,473
154,766
188,042
193,366
187,135
190,712
195,113
176,603
156,602
165,125
174,145
.(Oct 1976 - Sept
Elec-
tric
ener-
gy pro-
duct ,
MWh
10
59,238
76,374
85,981
101,262
104,128
100,773
102,699
105,069
88,212
82,422
86,908
91,655
1977)
Coefficient
of evapora-
tion losses
m3/MWh
11
2.59
2.27
2,28
2.15
2.33
2.38
2.40
2.55
2.73
2.64
2.58
2.59
nr/Gcz
12
1.40
1.26
1.27
1.16
1.26
1.28
1.29
1.38
1.44
1.39
1.36
1..36
-------
level in the cooling water channel. The quantity of blowdown water discharged
was measured with a sampling bucket and stop watch.
The water demand data for the cooling system are given in Table 15 for
the period under investigation (October 1976 - November 1977). Since there
was no way to measure the drift, its value was assumed at 0.1 percent Q since
drift eliminators were not present; the amount of evaporative loss as a per-
centage of the total make-up water, (column 8) divided by (column 4) in
Table 15 ranges from approximately 75 to 90% with an average of 86%. From
May to August, the percentage is lower than during the remaining months of
the year. The amount of heat discharged due to evaporation as compared with
the total heat discharge of the cooling system is approximately 68 to 83% and
during the period under investigation its average is approximately 77%. From
May to October, the percentage is slightly higher than during the remaining
months of the year. The steam power plant make-up water balance is character-
ized by the following proportions:
- evaporation 85.9%
- drift 7.9%
- blowdown 6.2%
The foregoing calculations can be partly compared with the results of
unique measurements made at the 300 MW Neurath C Power Plant, Federal Republic
Germany for a cooling tower of 100 m height and 74.5 m diameter at the base.
The cooling cycle parameters are as follows:
- Q - cooling water flow = 29,600 m3/h
-4"t* - temperature rise through the condenser = 12.6° C
- C|< - power plant discharge of heat, 1243 Kcal/kWh
- temperature of hot water discharge - 34.2° C
- temperature of intake water - 21.6° C
- temperature of air - 9.5° C
- wet - bulb temperature - 7.6° C
- air relative humidity - 77%
- design drift - 0.054% Q
- design evaporation losses - 1.61% Q « 1.59 1/kWh
which equals 68.6% of the total heat loss
Studies by numerous specialists from many countries were carried out
from July 1973 till July 1976. 187 series of measurements were made covering
all seasons of the year, as shown in Table 16 below.
Cooling Tower Studies at Neurath C Steam Power Plant
Year Season of Study Period J1uraber_ of Series
the Year of Measurements
1973 Summer July 18 to July 22 14
1973 Autumn Sept. 28 to Oct. 6 28
1973 Winter Dec. 14 to Dec. 16 29
1974 Summer June 25 to Aug. 25 20
1975 Winter Feb. 7 26
1975 Summer June 17 to June 20 11
1976 Winter Feb. 1 to Feb. 5 9
1976 Summer July 2 to July 6 50
187
' 47
-------
The site measurements included:
- cooling water flow
- water temperature
- climatic conditions
- thermodynamic state of cooling tower plume
- distribution of droplet size
- speed and direction of wind up to 1600 m altitude
The results of research were presented in the papers of Baer et al.
(1974; 1979) and Dittrich and Ernst (1980). Utilizing the above papers, the
portion of evaporative heat loss was calculated. The values obtained are given
in Figures 16 and 17. The calculations show that the proportion of evaporative
heat loss varies within a wide range depending on climatic conditions, par-
ticularly temperature and humidity of the ambient air.
In winter when the air is cool and humid, the portion of evaporative heat
loss amounts to approximately 50% while in the summer, when the weather is
hot and dry, it can reach 90%. The average heat exchange due to evaporation
amounts to approximately 72.9% at a mean air temperature of 14 degrees C.
Through a least squares analysis the average portion of evaporative heat loss
was shown to be expressed as:
Ac = 60 + 0.833 ta(%) (2)
where:
Ac = share of evaporation in the process of heat exchange
ta = air temperature, degrees C.
Evaporation losses, as a percentage of total cooling water flow, as nor-
malized to t = 10 degrees C are shown in Figure 17. The losses change within
the range of 0.9 to 1.7% Q. The average value of evaporation losses for the
Neurath Steam Power Plant for t = 11.44 C amounted to 1.565% Q. An esti-
mate of cooling water evaporation losses in percent of cool water demand is:
Qe = (0.11 H- 0.00156 ta) t (3)
where:
Qe - evaporation losses in percentage of cooling water demand
ta - temperature of air °C
t - heating in condenser °C
A comparison of the field study results obtained at Steam Power Plant
No. 7 and Neurath C show that the results obtained are very close. The differ-
ence between the estimates of the portion of evaporative heat loss obtained
by different methods, was within 3%.
Several additional studies of cooling system evaporative water loss have
been reported. A summary of some of these studies is presented below.
Berman (1957) presented the relationship between evaporative water loss
and air temperature as:
Qe =
-------
*
* a. o>
o
^
•' i
srsr
"8
§ 2 8
«m ait*
Co.
r«tlT
/&•**
I Z
Q3
M
O
f
!
S
ut
1C
*
r
• • *
<-• 4/
. •**?*
. /*• ••
•. v-*- •
"*.*';•• *•
.. v
t.
X
*
(*
.r.
'f
S
j!
5i
i
?
r
-------
This dependency can also be presented by the following formula:
Qe = (0.096 + 0.00213 ta)^ t Q /100 (5)
where:
ta = air temperature, °C
In later publications, a detailed analysis of the amount of evaporation
losses in a closed cooling system was also presented by Ortner (1973), who
related his calculations to the Rhineland region (GFR). To define the amount
of evaporation losses, Ortner applied Merkel's equation from 1921 (VIK 1970):
: £
Ai
Qe =
where:
Qe - evaporation losses (1/kWh)
^Cfc - heat discharged to the cooling system, assuming C|< = 1200 Kcal/kWh
- change of enthalpy of air between the inlet and outlet from the
cooling tower (Kcal/kg)
A x - change in content of water vapor in the air between the outlet and
inlet to the cooling tower (kg/kg)
r - coefficient compensating for change of heat balance as a result of
evaporation^ = 1 (unit loss).
The monthly amounts of evaporation loss are presented in Table 17. Calcu-
lations show that the average annual evaporation losses amount to 1.36 1/KWh.
Further calculations. (Andres, Ortner, Schiffers, 1974) show that evapor-
ation losses in conventional power plants amount to 1.38 1/kWh with nuclear
power plants having an increased amount of heat discharged in the cooling sys-
tem of up to 1720 Kcal/kWh and evaporative loss of 1.98 1/kWh. The following
increase of evaporation losses at higher air temperature was noted (Ortner,
Ritter, 1976):
Atmosph. Cond. Temp, of air °C Hum, of air% Increase in evap. loss. %
Annual average
Summer
Hot period
8.9
11.1
34.0
80.4
76.0
57.0
.
1.17
40.0
According to Heine and Weidlich, the values in Table 17 show that evapora-
tion losses are over 10% higher than those given by Ortner, while the seasonal
changes for these values are smaller.
EdF (1975) gives values of evaporation losses for nuclear plants. This
paper points out that for closed cooling systems with natural draft cooling
towers the share of heat discharged by evaporation varies within 60 to 70%,
though in some cases it can reach even 90%. Evaporation losses in France
were determined to be on average basis 1.980 1/kWh (Table 17). It was also
stated that under extreme conditions of 35°C air temperature and 30% humidi-
ty, evaporation losses can rise to 2.88 1/kWh, 45% higher than the annual
average.
50
-------
Table 17
Evaporation losses in closed cooling systems according to other authors
Author, reference region,
Subject matter
Months
Jan I Peb I Mar
Apr May |Jun Jul JAug |Sep joct [Nov [Dec
Annu-
al ave-
rage
Ortner /1973/, Rhineland
region GFR
Evaporation losses 1/kWh 1.14 1.15 1.23 1.34 1.48 1.60 1.61 1.59 1.47 1.32 1.21 1.15 1.36
Ortner /1973/, Rhineland
region GFR
Portion of heat exchange
due to evaporative
lessee % 51.3 51.7 55.3 60.3 66.6 72.0 72.4 71.5 66.1 59.4 54.4 51.7 61.1
Heine, Weidlich /1974/
region UDR
en Evaporation losses for
'" power plants using
saturated steam 1/kWh 2.09 2.12 2.23 2.30 2.48 2.48 2.52 2.52 2.45 2.34 2,20 2.09 2.32
Heine, Weidlich /1974/
region GDR
Evaporation losses for
power plants using
superheated steam 1/kWh 1,37 1.40 1.44 1.51 1.62 1.62 1.66 1.66 1.58 1.51 1.44 1.37 1.52
Ed* /1975/
Evaporation losses for
nuclear power plants
1 /KWh 1.73 1.80 1.87 1.98 2.09 2.16 2.23 2.15 2.12 2.02 1.91 1.73 1.98
-------
For Poland, annual average losses (1/kWh) are presented below:
Open Closed • Pond
Author System System System
Gadkowski (1971) 0.68 1.47 0.85
Spoz (1979) 0.85 2.04 0.97
Using the theoretical calculations and the results of field studies
made in Poland and in the GFR, it can be stated that the portion of heat ex-
change due to evaporation depends on meteorological conditions and mainly
on the air temperature. This dependence can be taken approximately as a
linear relationship. In the average Polish climatic condition, the share of
heat exchange due to evaporation losses is approximately 77%. In the case
of a conventional modern steam power plant with heat discharge to cooling
system C|< of approximately 1200 Kcal/kWh, this results in evaporation losses
of 1.714 1/kWh. This value is higher than the values given by other authors.
In earlier papers, only values given by Berman (1957) are very close to the
measured values.
3.3 Drift - Q
-------
They reported that drift depends on the construction of the cooling tower and
the kind of eliminators and conclude that it is difficult to make a general
drift loss estimate. In connection with the above, they have presented re-
sults of research on the contents of droplets in the plume leaving the cooling
tower. Both the drift and vapor condensation have an impact on the contents
of the droplets.
As stated by Dittrich and Ernst (1980), the droplet content increases
from about 0.2 g/kg of air to about 1.5 g/kg. The droplet content rises with
rising ambient humidity and decreases with rising ambient temperature. The
largest portion of water droplets form in the plume as a result of condensa-
tion. The diameter of such droplets is less than 10 m. Only a small portion
of the droplets in the plume are entrained by the air flowing through the
cooling tower. The diameter of these droplets is approximately 100 m. The
rate at which water droplets are entrained by the air flow is 2 kg/s which
equals approximately 0.0244% Q. In research conducted for this project, an
attempt was made to define the region subjected to the activity of the
cooling tower through examinations of rainfall, of the soil and of vegeta-
tion growing in the region. The research was conducted near the Lagisza
.power plant by a team from the University School of Wroclaw, supervised by
J. Pacyna. Examination of rainfall was made at 12 locations over a period
of 6 months from December 1979 till May 1980. The soil was examined twice
at 3 locations. The results show that the cooling towers cause an increase
of rainfall along a strip of about 2 km windward. Approximately 600 m
from the cooling tower, an increase of almost 30% of rainfall was observed,
and within 1300 m, rainfall increase amounted to nearly 10%.
In the case of the Lagisza power plant, the area of increased rain-
fall covers a part of the power plant such as: coal storage, slag storage,
warehouses, railway tracks and water tanks. Rainfall in the region surround-
ing the cooling tower shows an increase of concentration of pollutants such
as dissolved solids, sulphides, potassium chloride and sodium. The observed
increase of the average concentration amounted to: sulphides 2.6 times,
chlorides 3.0 times, calcium 3.6 times, magnesium 3.3 times. The authors
of this research state that this increase indicates the intensive absorption
in the cooling tower plume of pollutants contained in the air. These studies
did not indicate any significant impact of the cooling tower on the changes
of concentration of chemical compounds in the soil and growing plants.
3.4 Make-up Water to the Closed Cooling System
The amount of make-up water can be expressed by the following:
K L
Qm , _.„„„ [ Q (1 + ..„) ] + Qd + Q (7)
K - 1 Sa
where:
K - cycles of concentration; a dimensionless number which expresses the
number of times the concentration of any constituent is multiplied
from its original value in the make-up water
L - load of pollutants introduced to the cooling water as a result of
treatment of make-up water or washed out from the air (mg/1)
Sa - admissible concentration of pollutants in cooling water
53
-------
The importance of the component L/Sa should be evaluated individually
e.g., reducing the carbonate hardness of make-up water from 6° to 1 to 2°; by
using sulphuric acid one obtains an increase of sulphates in make-up water of •
approximately 80 mg/1 (1° of hardness = 10 mg/1 CaO (1). At an admissible
value for sulphate concentration of 500 mg/1, the expression L/Sa can consti-
tute about 15% of of Qe. The component L/Sa amounts to nearly 10% of Qe for
hydrochloric acid neutralization.
3.4.1 Water Treatment Plant Make-up Water Demand Qp
At the Polish steam power plants discussed in this report, Qp (water
for treatment) amounts to 3.5 to 4.5% of makeup water needs (Qm). Water station
Qp demands are rarely analyzed in the literature. This problem was discussed
by Ortner (1973), who reports Qp values for several power plants. In Power
Plant B these demands amount to 5 to 6% of the make-up water, in Power Plant
C, 6 to 8% of the make-up water. Detailed studies carried out in the E Power
plant from June 1966 till December 1968 have shown Qp to be 0.8 to 1.25%
of the make-up water. For the case K = 4, the equation indicates Q4 to be
0.019 to 0.035 1/kWh. Analogous research carried out in the F Power Plant from
November 1969 till the end of 1971 has shown the following Qp values as a pro-
portion of the make-up water:
- average for the year 1971 - 1.8%
- median value from November 1964 till June 1970 - 1.25%
- highest daily values from 'November 1964 till June 1970 (noted approxi-
mately twice a month) 3.3 to 6.6%
- average elementary Qp demand - 0.05 1/kWh
3.4.2 The Analysis of Demand for Make-up Water in Electric Power Plants
with Closed Cooling Systems
As part of the research carried out for this project, water demand was
examined in 12 power plants, the specifications of which are presented in
Appendix A.
The range of concentration of various pollutants in cooling water in
these plants results in a variation in K of between 2 and 10, whereas the dis-
charge of heat to the cooling cycle varies from 1160 to 3300 Kcal/kWh. The
ranges of variation of water demand indices, shown in Tables 19 to 21 and in
Figures 18, 19 and 20 point out the lack of close relationship between the unit
water consumption coefficients and the water concentrations coefficient K.
Instead, there is a clear relationship between the water consumption indices
and the unit heat discharge to the cooling system (Fig. 18). The higher the
unit heat discharge, the higher is the unit water consumption, assuming simi-
lar water management systems. The annual and monthly average indices of make-
up water consumption per unit of heat discharged to the cooling system
(Table 21) range within much narrower limits than the indices per unit of
electric energy production (Table 20).
The results obtained in Project J8-5-537-4 were compared with the re-
sults presented in earlier papers. For example, Lenssen (1968) reports that
the make-up water demand Qm varies due to temperature in the range 2.4 to
3 1/KWh for an average coefficient of concentration K in the range 4 to 5.
More detailed studies on the make-up water demand Qm were made by Ortner with
regard to lignite fired power plants located in the Rhineland region (GFR).
54
-------
Table 19
en
en
'ower
»lant
1
2
3
4
5
6
7
8
9
10
11
12
Installed
power
/MW/
15.8
93,9
156.4
161.3
179
200
220
600
840
860
1229.5
1400
Years of
observa-
tion
1961-63
1960-62
1966-68
1961-62
1960-62
1963-78
1958-78
1967-68
1975-78
1975-78
1973-78
1966-68
M a k e - u
in
average
monthly
3.85-9.08
3.00-6.10
1.78-4.70
3.12-5.19
1.77-3.93
1.89-4.80
1.93-4.02
1.15-4.05
1.70-2.94
2.39-3.35
2.02-3,28
1.77-3.35
p water demand
m3/ MWh
average
annual
5.32-5.53
3.95-4.15
2.89^-3.35
3.97-4.09
2.67-3.23
2.42-3.23
2.33-2.96
2.09-2.73
1.97-2.45
2.76-3.05
2.55-2.76
2.37-2.56
in m / Goal
average
monthly
1.21-2.75
1.30-2.59
0.89-2.05
1.30-2.16
0.87-1.93
1.15-2.60 '
1.04-2.18
0.84-3.39
1.25-2.16
1.78-2.41
1.32-2.58
1.27-2.59
average
annual
1.54-1.65
1.68-1.76
1.32-1.45
1.65-1.701
1.31-1.58
1.39-1.91
1.36-1.66
1.56-2.30
1.45-1.80
1.99-2.26
1.59-1.97
1.84-2.00
-------
Table 20
o
Monthly and annual average make-up water consumption indices in nr/MWh over the
under investigation
Power
plant
1
2
3
4
5
6
7
8
9
10
11
12
Jan
4.02
3.18
3.02
3.42
2.62
2.51
2.34
2.59
2.03
2.80
2.37
2.19
Feb
4.74
3.83
3.21
3.44
3.17
2.67
2.46
2.86
2.02
2.86
2,40
2.19
Mar
4.51
3.97
2,62
3.68
2.78
2.81
2.56
2.89
2.17
2.88
2.54
2.05
Apr
5.31
4.70
2.95
4.46
3.15
2.87
2.65
2.70
2.23
2.84
2.67
2.35
May
5.65
5.14
3.08
3.82
3.27
3.24
2.87
2.74
2.30
2.99
2.85
2.67
Jun
6.29
4.86
3.08
4.38
3.14
3.36
3.07
3.23
2.41
2.88
2.91
2.87
Jul
6.77
4.85
3.14
4.87
3.01
3.04
3.08
3.46
2.36
2.92
3.05
2.78
Aug
6.87
4.17
3.83
4.16
2.84
3.04
3.00
2.81
2.33
2.94
3.05
2.57
Sept
6.86
3.70
3.33
4.62
3.02
2.93
2.81
2.71
2.37
2.85
2.80
2.49
Oct
5.46
3.68
3.60
3.83
2.56
3.13
2.71
2.48
2.32
3.02
2.52
2.46
Nov
4.48
3.36
3.74
3.81
2.95
2.60
2.48
2.21
2.07
2.92
2.48
2.22
periods
Dec
4.54
3.09
2.50
2.85
2.62
2.55
2.34
2.57
1.90
3.00
2.35
2.16
Annu-
al
ave -
ra^e
5.44
4.04
3.13
4.03
2.93
2.88
2. $7
2.77
2.17
2.90
2.66
. 2.41
Notice: for power plant No 11 the average covers the period 1973-78.
-------
Table 21
Monthly and annual average make-up water consumption indices in m /Goal over the periods
under investigation
Power
plant
1
2
3
4
5
6
7
8
9
10
11
12
Jan
1.22
1.36
1.34
1.42
1.29
1.48
1.29
1.52
1.49
2.09
1.69
1.67
Peb
1.44
1.63
1.43
1.44
1.56
1.57
1.34
1.78
1.48
2.13
1.71
1.64
Mar
1.37
1.69
1.17
1.53
1.37
1.65
1.44
1.85
1.60
2.17
1.81
1.57
Apr
1.61
2.00
1.31
1.86
1.56
1.75
1.47
1.65
1.65
2.12
1.90
1.79
May
1.71
2.18
1.37
1.60
1.61
1.90
1.58
1.68
1.70
2,23
2.02
2.03
Jun
1.91
2.07
1.37
1.82
1.54
1.97
1.69
1.95
1.77
2.15
2.07.
2.19
Jul
2.05
2.06
1.39
1.89
1.49
1.79
1.73
2.10
1.74
2.18
2.17
2.11
Aug
2.08
1.77
1.50
1.90
1.40
1.79
1.66
2,51
1.71
2:. 19
2.18
1.96
Sept
2.08
1.58
1.47
1.65
1.56
1.72
1.53
2.11
1.74
2.13
1.99
1.90
Oct
1.66
1.57
1.59
1.58
1.26
1.84
1.49
2.01
1.70
2,26
1.79
1.87
Nov
1.36
1.43
1.66
1.59
1.45
1.63
1.38
1.92
1.93
2.18
1.76
1.69
Dec
1.37
1.31
1.26
1.61
1.29
1.44
1.29
2.10
1.40
2.23
1,67
1.64
Annu -
al
avera-
ge
1.60
1.72
1.41
1.68
1.44
1.71
1.49
1.93
1.63
2.17
1,89
1.84
Notices for power Wo 11 the average covers the period 1973-78,
-------
Ul
00
1 10,0
u 9,0
I/)
C f\C\
'u
1 7'°
o
.i GI°
| sp-
ID
o 4,0,
O
| 3-°
% 2,0-
i
1/-W
.
:
•
•
1
»
3
: 3
X-
1
3
('
„ Ran
^ coeff
i
a
. 3
t,
t 3
Range of average monthly water consumption
coefficients
ge of average annual water consumption
icients
•
• 3
t
i «
•
«
\\
a
>• *
^ V
)
:
t
•
1 , H ^
1500
2000
2500 3000
Heat discharge Real /KWh
Fig. 18 Make-up water consumption coefficients in cu m/MWh and unit heat discharge in power plants under investigation
-------
Range of average monthly water consumption
f
i I
E 10,0-
3
9,0-
U) '
c
& 8.0
0 '
it
o *
o
c 6^0
"S.
1 5,0
n i
U)
8 4,0
f30
•
§• 2P
i
^ 1,0
o
•
g
'
.. J
T'
: i
' •
1 :
?'
5
j
.
1 1
•
• i
»
I
. :
1 > 1
i
>
•
• *
* <
3
-j
M K
9
b
J
r
*
•
1— 1—
1 coefficients
Range of average annual water consumption
coefficients
i
° 4
m
w
b
•
»
f
— , — i 1 ; — i
^
3
6
10 Coefficient K
Fig, 1.7 Make-up water consumption coefficients in cu m/MWh and K coefficients in power plants under investiqation
-------
ro
Make-up water consumption coefficients cu m / Gcal
\_«
£)
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-------
These studies involved the following power plants:
A - Fortuna - 1000 MW
B - Frimmersdorf - 2600 MW ,
C - An old type power plant with approximately 50 MW units
E - Nideraussen - 2700 MW
F - Weisweiler - 2300 MW
G - an old type power plant with approximately 50 MW units of
total power of 220 MW
The studies were conducted during the period from June 1966 to December
1968. The average make-up water demand Qm amounts to 2.435 1/kWh, but for
particular months and power plants, it varies between 1.63 to 3.60 1/kWh.
The results of the analysis of water management in Polish power plants show
that the annual average index of water demand in modern Polish steam power
power plants (Power Plants 5 to 12) averages 2.67 1/kWh and is about 10%
higher than the corresponding index from the GFR (2.435 1/kWh). In Polish
power plants, water management is more flexible because seasonal changes
of indices generally do not exceed 20%. Therefore, the units m^/Gcal
for heat load to the cooling system are more appropriate for analysis than
the units m^/MWh. The average value of this index for Polish steam power
plants (excluding Power Plant No. 10) is 1.68 m^/Gcal with changes for
other power plants ranging up to approximately 15%. The analysis of index
m^/Gcal shows that the water demand only slightly depends on the quality
of intake water. In many cases, lower rates are obtained for more polluted
water, showing that the water consumption does not strongly depend on
the concentration coefficient K, but on other processes within the power
plant.
3.5 Total Water Balance of Steam Power Plants with Closed Cycle Cooling
Systems
The analysis of total water balance was developed based on data from 5
steam power plants for power plant capacity and water consumption, including
the cooling system, the steam system, the heat generating system, hydro-
transport and administrative use per month over the period of 1975-1978.
Table 22 summarizes water consumption for particular purposes. Also shown
is the source of water for ash transport, normally made-up by blowdown and
waste water from the demineralizers and clarifiers. Small amounts of fresh
water for ash sluicing are used only for certain time periods in power
plants No. 6 and No. 11, but these quantities were not measured. Power
plant No. 7 is provided with a dry ash and slag discharge system. The
small quantities of water used for slag quenching are given in the Table.
The municipal hot water heating systems are, as a rule, supplied with boiler
blowdown and polluted condensates. For this purpose, only Power Plant
No. 7 utilizes fresh water while Power Plant No. 6 utilizes only small quan-
tities which are noted under the demand for the steamwater cycle. Approxi-
mately 85-95% of fresh water supplied to the steam power plant is utilized
to compensate for the losses of the cooling system, almost 4 to 12% compen-
sate for the losses of the power cycle and nearly 1 to 3% is utilized for
administrative purposes (Table 22). Figures No. 21 to No. 24 show the course
of average daily changes of the total water demand in particular months,
demand for cooling system make-up and for production of electric energy over
the period 1975-1978 under investigation. The maximum unit cooling water
demand occurs in summer, when the electric energy production is normally
lower. In winter, when the unit water demand is lower, the production of
electric power is normally higher.
61
-------
Table 22
o
Water consumption for particular purposes in power plants under investigations nr/MWh
Steam
power
plant
6
7
9
10
11
Year
1975
1976
1977
1978
1975.
1976
1977
1978
1975
1976
1977
1978
1975
1976
1977
1978
1975
1976
1977
1978
Noticei 1.
2.
3.
4.
5.
Cooling cycle
fresh
water
3.12
2.86
2.88
2.99
2.62
2.74
2.85
2.56
2.45
2.16
2.10
1.97
2.81
2.67
3.05
3.05
2.55
2.55
2.71
2.68
water
treatment
plant
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
0.076
0.037
0.044
0.043
0.098
0.098
0.104
0.104
Within the range of
Water in
Polluted
S'team -water cycle
fresh
water
0.21
0.19
0.18
0.21
0.36
0.32
0.28
0.30
0.19
0.19
0.15
0.18
0.12
0,12
0.12
0.12
0.16
0.17
0.17
0.17
water pre-
paration
plant
0.068
0.048
0.043
0.047
0.013
0.012
0.013
0.014
0.040
0.040
0.030
0.040
0,017
0.016
0.016
0.017
0,032
0.023
0.029
0.021
Hot
water
heating
systems
0.0260 3/
0.0115
0.0309
0.0398
o.ooga4/
0.0105
0.0228
0.0170
0.0243''
0.021
0.020
0.019
0.00683/
0.0087
0.0121
0.0119
Ash
tran-
sport
n.d.
n.d.
n.d.
n.d*
„,
-
-.
— K/
0.050 5/
0.074
0.021
0.023
0.57 5/
0.85
0.49
0.43
n.d.
n.d.
n.d.
n.d.
Slag
Qu-
en-
ching
—
—
-
—
0.050
0,016
0.061
0.121
_
—
—
-
—
—
-
-
•M
—
—
—
Admini-
strati-
ve pur-
poses
0.023
0.021
0,019
0.022
0.060
0.046
0.037
0.043
0.050
0.065
0.072
0.074
'0.080
0.041
0.037
0.027
0.025
0.020
0.021
0.022
Total
fresh
water
demand
3.35
3.07
3,08
3.22
3.10
3.14
3.25
3.04
2.69
2.42
2.32
2.22
3.01
2.83
3.21
3.20
2.74
2.74
2.90
2.87
150 nr/ month per power plant
not processed
condensates boiler blowdowns
Presh water
Cooling tower blowdown waste water from
demineraliziers and clarifiers.
-------
Of*
a
5 >,
E a
u'
8
o
10-
9
8
7
6
5
4-
3
-
o
o
o
4
3
2
II III IV V VI VII Vlil IX X XI XII
1975
i i l
II III IV V VI VII VIIIIX X XI XII
1976
II III IV V VI VII VIIX X XI XII
1977
\
ii lii iv v vi vii viii ix x xi xii
1978
make-up water consumption for cooling purpose
total water consumption
electric energy production
Daily electric energy production and water consumption in power plant No 7
-------
£
3
o
34-
32
30-
28-
26-
24-
22-
.c
o
o
o
14-
13-
12
11
10-
9.
ii iii iv v vi vii viii ix x xi xii I i! in iv v vi vii viii ix x xi xii i li HI iv v vi vii vin ix x xi A i 11 111 iv v vi vii viinx x xi X'H
1975 1976 i 1977 1978
make-up water consumption for cooling purpose
total water consumption
electric energy production
Fig..22 Daily electric energy production and water cpnsurnption in power plant- No 9.
-------
en
01
350
oA8
8A6
- AA
A2
AO
38
36
3A
32
30
28
26
2A
II III IV \) VI VII VIII IX X XI XI!
VI VIIIIX
1975
IV* V V! VI! VIIIIX X
1976
1977
III IV V VI VII VIIIIX X XI XII
1978
make-up water consumption for cooling purpose
total water consumption
electric energy production
Fin.
Dnilu
-------
CT>
cn
(J
O
O
O
56
54
52
50
48
46
44
42
40
38
ill iv v vi vii viii kx xl
1975
XI!
IV V VI VII VIII IX X XI XII
1976
IV V VI VII VIII IX X XI XII
1977
II III IV V VI VII VIII IX X XI XII
1978
make-up water consumption for cooling purpose
total water consumption
electric energy production •
Fig. 24 Daily electric energy production and water consumption in power plant- No 11
-------
This has an impact on the annual water demand of the steam power plant.
The changes in water demand are largely in conformity with the pattern of change
of electric energy, capacity of the plant.
The results of the present study were compared with the results presented
in earlier papers, e.g., Ortner (1973) reports that the average total water
demand for a power plant amounted to 2.80 1/kWh. However, in old type power
plants, the demand was much higher, e.g. in Power Plant C demand averaged 3.8
1/kWh, and in the Power Plant G, it averaged 3.2 1/kWh. In particular seasons
of the year the indices of total water consumption in the power plants varied
30 to 40%. Total make-up water demand for power plants with closed cooling sys-
tems was also defined by Heine and Weidlich. According to these authors, modern
power plants with superheated steam have average values of the total demand
amounting to 3.017 1/kWh for K - 2 and 2.267 1/kWh for K = 3. It should also
be mentioned that these values are lower than the average indices of demand de-
fined by Ortner, based on statistical analysis of measured consumption.
The data obtained in the present project show that the average index of
the total water demand in Polish steam power plants with closed cooling systems
amounts to 2.92 1/kWh which 1s approximately 4% higher than the corresponding
index of 2.80 1/kWh for GFR power plants. However, water demand in Power
Plants No. 6, 10, and 11 could be reduced by elimination of the excessive blow-
down resulting from the excessive use of water for ash disposal. This point
is confirmed by the proportion of the amount of total waste water discharge in
these steam power plants (Table 23).
3.6 Discussion
Research was conducted on the water balance of steam power plants, both
in the cooling system and for the entire plant. Research on the total water
balance was carried out in 5 steam power plants located in Silesia. Data
from 12 other power plants were utilized, including a special analysis for
Plant Mo. 7. It has been noted that closed cycle system water consumption
constitutes 85-95% of the total water consumption. Water-steam cycle con-
sumption was noted to range within approximately 4 to 12%, while social and
administrative needs consume 1 to 3%. Other needs are mainly for waste
water. The heat generating cycle losses are usually due to polluted conden-
sates and boiler blowdown. Cooling system blowdown and waste water from de-
mineralization stations and clarifiers are utilized for hydro-transport needs.
The amount of waste water discharge, as compared with the water demand, ranges
within 5 to 30%. In the case of steam power plants, where the share of total
waste water ranges within as much as 20 to 30%, it seems to be the result of
faulty functioning of the ash disposal system which causes excessive make-up
water consumption and increased waste water discharge.
Cooling water evaporation losses constitute the largest factor in make-up
water balance.. In Poland, the share of evaporation in the process of heat
discharge in the closed cooling towers amounts to 77%, which is approximately
3% higher than in the GFR. This difference may be due to climatic conditions.
The portion of evaporation losses in total make-up requirements ranged from
75 to 90%, with an annual' average of approximately 85%. The analysis of make-
up water consumption shows that a definite relation exists between consumption
of water for these purposes and the unit heat discharge into the cooling system.
On the other hand, there is no evident relationship between water consumption
and the quality of water. The maximum unit water consumption is in May and
June; the minimum unit water consumption is in January and December. As a rule,
deviations from the annual average do not exceed 20% - depending on the season
67
-------
Table 23
Share of fresh water consumption for particular purposes
in power plants under investigation /%/
Steam
power
plant
Year
Cool-
ing
cycle
Water
steam
cycle
Hot wa-
ter hea-
ting
system
Ash tran-
sport and
slag gue-
nching
Admini-
strati-
ve pur-
poses
Total
waste
water
10
11
1975
1976
1977
1978
1975
1976
1977
1978
1975
1976
1977
1978
1975
1976
1977
1978
1975
1976
1977
1978
93.1
93.2
93.5
92.9
84.5
87.3
87.7
84.2
91.1
89.4
90.4
88,6
93.4
94.3
95.0
95.3
93.1
93.1
93.4
93.3
6.2
6.1
5.9
6.4
11.7
10.3
8.6
9.9
7.0
7.9
6.5
8.1
4.0
4.2
3.7
3.8
5.9
6.2
5.9
5.9
0.8
0.4
1.0
1.2
0.3
0.3
0.7
0.6
'0.9
0.9
0.9
0.8
n.d.
n.d.
n.d.
n.d.
0.02
0.03
0.04
0.04
n.d.
n.d.
n.d.
n.d.
1.6
0.5
1.9
3.9
1.8
3.0
0.9
, 1.0
18.9.
30.0
15.3
13.4
n.d.
n.d.
n.d.
n.d.
0.7
0.7
0.6
0.7
1.9
1.5
1.1
1.4
1.9
2.7
3.1
3:3
2.6
1.7
1.2
0.9'
1.0
0.7
0.7
0.8
24.8
20.7
22.1
9.2
7.3
4.9
5.8
7.5
12.2
11.8
8.4
9.6
22,9
34.7
30.6
31.9
25.4
17.8
15.2
18.3
68
-------
treatment of the make-up water. One of the reasons for higher water consumption
could be faulty sewage management, mainly as a result of inefficient ash-removal
systems. A significant decrease of water demand by the power plant can be ob-
tained by reusing water for the cooling system and by use of sedimentary waters
from ash disposal and municipal sewage. Such solutions also limit or even elim-
inate troublesome discharges resulting from ash system disposal. Experience
gained in Poland shows that these approaches may allow reduction of the total
water supply requirement by approximately 15 to 20% with considerable reduction
of the amount and load of discharged pollutants (Gadkowski, et al. 1980). Be-
cause of large variations in the amount of heat discharged to the cooling
systems, ft is suggested that indices of water demand in 1/Mcal or M^/Gcal of
discharged heat should be used when comparisons of power plant water need are
made.
69
-------
Appendix A
o
Specification of steam power plants
Po-
wer Year
pla-
nt
1 2
1 1961
1962
1963
2 1960
1961
1962
3 1966
196?
1968
4 1961
1962
5 1960
1961
Rat-
ed
out-
put
MW
3
15.8 ,
93.6
156.4
161.3
179
Running
time
per year
0? hour
4
1200
4100
4700
4700
4640
3700
5200
Heat dis-
charge to •
the cool-
ing system
Koal/kWh
5
3300
2350
2290
2190
2270
2400
2030
C o
make-up water
source
6
water from deep
well
bituminous coal
mine water and
waste water from
chemical plant
bituminous coal
mine water
highly polluted
river
bituminous coal
mine water /1C$)/
waste water from
chemical plant
/20$/, municipal
water /70# /
oling water
make-up water prepa- concentra -
ration method *£&ee R
7 8 -
water decarbonized, 10
with lime corrected by
sodium metahexaphos -
phate to 2 mg PP0R /I
level * °
water deoarbonized 2.5
with lime
decarbonized with 2.5
lime
hydrochloride acid 2.0
grafting to general
hardness 1-1.5 mval/1
hydrochloride acid 6,0
grafted water
-------
1 | 2 3
4 .
6 1963 200 6200
"1964
1965
1866
196?
1968
1975
1976
1977
1978
6000
6200
6550
6950
6600
5800
6100
60000
5500
7 1958 220 5900
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1975
1976
1977
1978
5300
4700
6600
6500
6700
5900
6000
5600
5800
5500
3900
4100
5200
4400
8 1965 160 5200
1966 360 5800
1967 540 4600
1968 600 3800
9 1975 840 4800
1976'
1977
1978
5100
5300
5500
5
1740 municipal
1740
1711
1690
1650
1680
1715
1715
1715
1715
1770 municipal
1770
1770
1770
1770
1770
1770
1770
1770
1850
1800
1840
1840
1840
1840
6 7 8
*
water hydrochloric acid
grafting and stabili-
zation with silenal S 4-7
*
water deoarboni zation with 7«2
lime and filtration
1370 water from highly water prepared on ea- 2«4
1310 polluted river tion exchangers
1235
1360
1360 river water decarboni zation with
1360
1360
1360
lime and coagulation
with ferric sulphate
-------
ro
1
10
11
12
2
1975
1976
1977
1978
1958
1959
1960
1961
1962
1963
1964
1965
1966
1973
1974
1975
1976'
1977
1978
1964
1965
1966
1967
1968
I 3
860
199.1
199.1
199.1
187.5
175.0
175.0
175.0
175.0
175.0
1229.5
1229.5
1229.5
1229.5
1229.5
1229.5
905.8
1283.3
1400.0
1400.0
1400.0
I «
4900
5000
5000
5000
5860
5690
5870
5800
6100
5900
5800
5100
4920
5500
5500
5500
5700
5300
5100
5900
5200
5150
5600
5700
I 5 I
1340
1340
1340
1340
2310
2310
2310
2310
2310
2310
2310
2310
1957
1423
1445
1407
1400
1400
1400
1360
1330
1310
1290
1280
6 . I 1 \
water from river, sulphiric acid grafting
municipal mains and
mine water
bituminous coal till 1960 de carbonization
mine water with lime and hydrochlo -
ride acid grafting from
1960 de carbonization with
lime and coagulation with
ferric sulphate and at a - •
bilization with sodium
polyphosphate
•
river water without preparation
8
3
till 1960
K a 4
after
1960
K = 2.5-
3.0
3.6
-------
REFERENCES
Section 1:
1. Jabukik A. and H. Maciejewski. Influence of Methods of Cooling
Water Treatment and Turbine Condenser Screen cleaning on the reduction
of fuel consumption in power stations, Energetyka, April 1976.
2. Kirnbauer, H. and A.J. Freedman. VGB Speiserwassertagung, Special
Publication, 1965, 49-57.
3. Magou, J. et al. La Centrale Termique de Martique-Ponteau.
La Technique Moderne, 1971.
4. Maciejewski, H. Methods of Elimination of the Results of Improper
Water Quality in Water-steam and Cooling systems, 1978.
5. Mainier. Les ouvrages Hydrauliques de la Centrale de Lacq-Artix.
La Technique Moderne, May 1960, Number Special.
6. Marianski W., et al. Analysis of Conditions of Operation of Travelling
Screens and Grill Cleaning on Cooling Water Intakes for Power Plants,
Conclusions and Recommendations Concerning the Range and Directions
of their Modernization. Energopropjekt - Warsaw, November 1978.
7. Minimi, M. I circuiti dell Asqua Refrigerenta Nelle Central!
Termoelecttriche, L'Energia Ellecttrica Mr 1, 1967.
8. Svierdlov, A. J., Simanski, 6. A., Kikis 0. V., and I. I, Nolcanov.
Novyi Sposob Borby z Obrastanism Circulacionnycg Traktov Blocriych
TES Rakovinanri Molljuskov. Electriceskie stanci No, 8, 1971.
Section 2:
9. Dojlido, J. Studies of the In-fluence of Heated Water Dischange
from the Uozienice Power Plant on Physical and Chemical Processes and
Water Quality in the Vistula River. IMWM, Warsaw, Sept. 1976
10. Dojlido, J., et al. Studies of the Influence of the Heated
Water Dischange from the Stalowa Wola Power Plant on the San River.
IMWM, Warsaw, Nov. 1976
11. Kloze, J., et al. Evaluation of Experimental Results Carried Out
in the Dabie Lake and the Odra River During 1974-1976. IMWM, Warsaw
1975 & 1977.
12. Kloze, J. et al. Evaluation of changes of Hydrpthermal Chemical
and Biological, as well as Ichtyological Conditions in the Dabie Lake
and the Odra River caused by Odra Power Plant operation .
IMWM, Warsaw, April, 1978.
73
-------
13. Bierwagen, H., Dojlido, J. and E. Gantz. Investigations Carried
Out from April 72 till March 73 in Order to Establish the Influence
of Heated Water Discharges from the Ostroteka Power Plant on Hydro-
Chemical Conditions in the Narev River and the Zegrze Lake.
IMWM, Warsaw, 1973.
14. Bachanek, S., Pietkswsks, B., and T. Zido Analytical and Technological
Examination of Wastewater from the Gdansk Power Plant. IMWM, Gdynia, 1975.
15. Dania A., and E. Kaliszewsks. Thermal, Hydrochemical, Hydrobiological and
Ichthyological Analysis of Water in Rybnik Reservoir Carried Out During
Phases of Construction and Operation. Energopomiar, Gliwice, 1976.
16. Kalisrewsks, E., Wieczorek, J., and M. Wyszatkieiscz Existing
Water Quality in the Zory and the Rybnik Reservoirs and Projections for
the Near Future. Energopomiar, Gliwice, 1979.
17. Kaliszewska, E. Chemical and Biological Analysis, of Water in the
Rybnik Reservoir to Establish the Environmental Impact of the Heated
Water Dischange, Energopomiar, Gliwice, 1979.
18. Florcryk, H., Golowin, S., and A. Sol ski. Impact of the Heated
Water Discharge on Chemical and Biological Conditions in the Vistula
River. IMWM, Wroclaw, Nov. 1970.
19. Florcryk, H., Golowin, S., and A. Solski. Analytical and Technological
Examination of Wastewater from the Turow Power Plant, IMWM, Wroclaw,
Nov. 1975.
20. Tyralsla, W. Studies of the Changes in Water Quality in the Turow
Power Plant Closed Cooling System. IMWM, Wroclaw, Nov. 1977.
21. Zembaty, W., and S. Radwanski Cooling Tower Projections for Power
Plant Cooling Systems. Institute of Energetics, 12824, Warsaw, 1978.
22. Pacyna, J., et al. Studies of Washout of some Pollutants from
Power Plant Cooling Towers. Institute of Environmental Protection
Engineering, Warsaw Technical University, Wroclaw, 1979.
Section 3:
23. Berman, L.D. Isparitielnoje ochlozdienje cirkulacjonnoj wody,
Gosenergoizdat, Moskwa - Leningrad, 1957.
24. Andres, 0., G. Ortner, and A. Schiffers. 1970-1985. Zusatzwasser fur
nasse kuhlturne. Energie 26. Jahrgang, Juli/August 1974, Heft 7/8,
s. 235-243.
25. Baer E., H. Brandes, P. Brog, W. Casper, C. Dibelius, W. Dittrich,
A. Ederhof, G. Eenest, K. Natusch, W. Ott, M. Pollach, M. Poppe. W. Roller,
H. Rogener, H. Ruhl, H. Scharrer, and 0. Wurz. Undersuchungen ab
einem Naturzug - Nasskuhlturm. Fortschritberichte VDI Reihe 15. nr 6,
Juli 1974 s. 60.
74
-------
26. Baer, E., Bartels, H. Brandes, F. Buchhloz, L. Candron, P. Dewagenaere,
G. Dibelius, H. Dittrich, A. Ederhof, W. Egler, G. Ernst, H. Rogener,
W. Erlangen, P. Violett, and D. Wurz. Thermodynamische Untersuchungen
am Naturzug - Nasskuhturme des kraftwerkes Neuratss and Model!e fur
das Betriebsverhalten und die Schwadenausbreitung. Fortschrift -
Bertichte VSI Reihe 15, nr 7 Dez. 19 s. 217, 1974.
27. Dittrich, H., and G. Ernst. Field measurements of cooling towers.
Results and conclusion. Cooling Tower Workshop; Electric Power Research
Institute; San Francisco, California, September 1980, s. 7.
28. Dossier, E. Electricite de France. Direction de 1 Equipment,
Note N.V. Le 31 Janvier, 1975.
29. Freier, R. Kesselspeisewasser. Kuhlwasser Walter d. Breuyter Co. 2
Aufl. Berlin. 1963.
30. Gadkowski et al. Water Demand in Energetics. Archieve of Hydrotechnic
9, 1971.
31. Gadkowski et.al. Water Management Optimization in Closed Cooling
Systems. IMWM, Warsaw, 1980.
32. Heine, A., and H. G. Weidlich. Die Umweltbeeinflussung durch
Kuhlsysteme von Warmekraftwerken unter den bedingungen der DDR.
Energietechnik 24, Heft 7, Juli, 1974.
33. Heller, L. 13. Kuhwasserprobleme der Kraftwerke Energie - Technik,
VEB - Verlag Technik 2 Jg., H.2.
34. Lensen, G. Wasser in dar Energiewirtschaft Vertrag. 14 Marz. 1968,
Schlussbereicht. Wasser Berlin, 1968.
35. Ortner, G. Die Wasserwirtschaft der Warmekraftwerke am Beispiel der
Rheinischen Braunkohlekraftwerke. Von der Fakultat fur Bauwesen der
Westfalischen Technischen Hochschule Aachen. Dezember 1973.
36. Pacyna J., Kuklinski A. and 6. Kmiec. Impact of Cooling Tower
Operations on the Environment Institute of Environment Protection
Engineers, Warsaw Technical University, Warsaw, 1970.
37. Spoz, J. Water Demand and Water Use in Power Plants. Water
Management 6, 1979.
38. Zembaty, W., and J. Radwanski. Cooling Tower Projections for Power
Plant Cooling Systems. Institute of Energetics, Warsaw, 1978.
39. V.I.K. Der Kuhwassergrenpreis eines Kondensationsdampfraktwerkes.
Verlag Energisberatung, Essen, 1970.
40. Ortner, G., K. Ritter. Die Verdeungsverluste als begrenzender
Faktor fur Standorte thermischer Krafwerke an mittleren Flusen.
Energie 27. Jahrgang, Heft 8, August 1976.
75
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 905/9-82-003
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Environmental Evaluation of European Power Plant Cooling
Systems
A Polish Research Project
5. REPORT DATE
April, 1-982
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
M. Gadkowski, E. Czarnecka - Nieminska, & H. Spoz-Dragar
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Institute for Meterology & Water Management
61 Podlesna Street
Warsaw, Poland
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
JB - 5-537-4
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency, Region V
230 S. Dearborn Street
Chicago, Illinois 60604
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
A PL-480 project under auspicies of the Maria Skladowska - Curie Fund
16. ABSTRACT
Section 1 - The following methods of protecting cooling systems against the detrimental
influence of impurities contained in cooling water are discussed, with
emphasis on Polish experience.
- removal of mechanical impurities contained in water drawn for cooling
- removal of mechanical and chemical sediments formed on condenser tubes
- protection of cooling systems aqainst the formation of mechanical and
chemical sediment or scale and biological fouling
Current techniques are evaluated and several proposals are presented. It is apparent
that most technical approaches emphasize power production needs, while technical
solutions which take into account both power engineering and the interests of the
environment, such as fish protection, are less common.
Section 2 - Effects of power plant cooling systems on surface water quality are discuss
based on investigations done for this project and on prior (see attached
s~heet)
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lD6NTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS (TIlis Report/
21. NO. OF PAGES
Release Unlimited
20. SECURITY CLASS (Thispage)
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
-------
16. ABSTRACT (continued)
Polish investigations. For open cycle cooling systems, no
significant differences between influent and effluent
concentrations of metals were determined. For closed
cycle cooling systems, higher concentrations of metals in
the effluent were found than predicted. The possible
contribution of washout of air pollutants in the
cooling tower is discussed.
Section 3 - Studies were conducted regarding the relation between
evaporative water loss and makeup water demand at a number
of Polish power plants with closed cycle cooling systems.
Comparisons are made with similar results for other
European power stations. Recommendations for reduction
of water supply requirements at the Polish plants are
given.
US- E.vi.on-,.^ ,j ,'. r::
230 South DaJfi; -.rn t%,.
Chicago, Illinois 60604
------- |