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1

Using ozone to treat cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

Webster, L.

1995-07-01

2

Mycobacteria in Finnish cooling tower waters.  

UK PubMed Central (United Kingdom)

Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4)  cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination.

Torvinen E; Suomalainen S; Paulin L; Kusnetsov J

2013-08-01

3

Alternative cooling tower water treatment methods  

Energy Technology Data Exchange (ETDEWEB)

The factors that contribute to proper water balance include total alkalinity, calcium hardness, and pH. In order to keep the cooling tower from scaling or corroding, a manipulation of these components is often necessary. This has traditionally been achieved with the use of chemicals, including but not limited to the following: acid, soda ash, sodium bicarbonate, calcium bicarbonate, algicide, and bactericide. Extensive research has shown that a balanced water system can also be achieved by using the proper combination of copper with a known halogen. Microbiologists have determined that a small amount of copper, acting as a supplement to chlorine at 0.4 ppm, has the same efficiency as 2.0 ppm free chlorine. Therefore, by using the following combination of components and procedures, the desired results can still be achieved: production of copper compound ions as a supplement to the chemical regimen; analysis and manipulation of make-up water; the use of copper as a coagulant for reduction of scale; copper as a supplemental bacterial disinfectant; and copper as an algicide.

Wilsey, C.A. [Water Clear, Mound, MN (United States)

1996-11-01

4

Water cooling tower and water level control system therefor  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an improved water cooling tower system including a water cooling tower structure having a top portion, a bottom portion, an intermediate portion therebetween, a water-collecting basin operatively disposed in the bottom portion of the structure, a heat exchange means operatively disposed in the intermediate portion of the structure, means for recirculating the water from the water-collecting basin to the top portion of the structure and feeding the recirculated water into the top of the heat exchange means, means for moving air through the heat exchange means drawing heat from the water for evaporating a portion of the water while cooling the non-evaporated water, means for utilizing the cooled water for at least one of air-conditioning and water-cooling purposes, conduit means operatively coupling a source of fresh water to the water-collecting basin for restoring the water lost in the evaporation process, the conduit means including a signal-responsive hydraulic valve means operatively coupled therein, the hydraulic valve means including a water inlet, a water outlet, a control port, and means responsive to the control signals at the control port for opening and closing the hydraulic valve means, the hydraulic valve mans being responsive to an ADD WATER control signal for passing the fresh make-up water through the fresh water conduit to the water-collecting basin and being further responsive to a DON'T ADD control signal for preventing the passage of fresh make-up water through the conduit means, the water in the water-collecting basin having a predetermined desired water level.

Kinkead, C.W.

1989-06-06

5

Cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A cooling tower in which the heat exchangers are arranged to form radially spaced concentric vertical cylinder walls, with air shields being positioned between the concentric cylinder walls to direct air flow through the exchangers. The air shields are upwardly inclined toward the tower center to approximate natural air flow.

Kosten, G.J.

1981-01-06

6

Hybrid cooling tower  

Energy Technology Data Exchange (ETDEWEB)

In hybrid cooling towers dry and wet cooling are combined. In this way the length of the visible vapour plume in comparison with the wet cooling tower is reduced and the cold water temperature is lower in comparison with the dry cooling tower. The paper describes in simple mathematical terms the operational performance of natural draught hybrid cooling towers and the propagation of the vapour plume, in order to be able to make calculations for a wide range of environmental conditions. A general answer cannot be given as to whether the higher costs associated with hybrid cooling towers are in reasonable proportion to the advantages.

Navarrete, P.; Schnabel, G.; Ernst, G.

1984-10-01

7

Program for monitoring LDB concentrations in cooling-tower waters  

Energy Technology Data Exchange (ETDEWEB)

A brief description is presented in tabular form describing the program employed by the Industrial Hygiene Department of the Oak Ridge National Laboratory to monitor and control levels of Legionella in cooling tower waters. Guidelines are listed to protect personnel from an exposure that could lead to legionnaire's disease.

Porter, W.E.

1983-01-01

8

Factors stimulating propagation of legionellae in cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

The authors survey of cooling tower water demonstrated that the highest density of legionellae, {ge}10{sup 4} CFU/100 ml, appeared in water containing protozoa, {ge}10{sup 2} MPN/100 ml, and heterotrophic bacteria, {ge}10{sup 6} CFU/100 ml, at water temperatures between 25 and 35C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 10{sup 5} CFU/100 ml, occurs in summer. The counts of legionellae correlated positively with increases in water temperature, pH, and protozoan counts, but not with heterotrophic bacterial counts. The water temperature of cooling towers may promote increases in the viable counts of legionellae, and certain microbes, e.g., protozoa or some heterotrophic bacteria, may be a factor stimulating the propagation of legionellae.

Yamamoto, Hiroyuki; Sugiura, Minoru; Kusunoki, Shinji; Ezaki, Takayuki; Ikedo, Masanari; Yabuuchi, Eiko (Gifu Univ. (Japan))

1992-04-01

9

Gasifier waste water treatment: Phase I cooling tower assessment  

Energy Technology Data Exchange (ETDEWEB)

Details of an advanced study of the treatability of waste waters from the fixed-bed gasification of lignite describe the test equipment and results at a pilot plant in North Dakota using stripped-gas liquor (SGL) as cooling tower makeup. Ammonia, alkalinity, phenol, and other non-hydantoin organics were removed from the cooling water by stripping and/or biological degradation, with the phenol concentration in the exhaust air exceeding the odor threshold. It will be necessary to control foaming of the circulating water, but both glycol and silicon based agents performed well during the test. It will also be necessary to reduce the high level of biofouling on heat transfer surfaces, although stainless steel fouling was not a major problem. The conclusion is that SGL is limited by potentially serious operating problems without additional treatment. 5 references, 4 figures, 7 tables.

Mann, M.D.; Willson, W.G.; Hendrikson, J.G.; Winton, S.L.

1985-02-01

10

Complex development of cooling towers  

International Nuclear Information System (INIS)

[en] Development of the design of cooling towers and recirculated cooling water systems at the Industrial Design Co. (IPARTERV). Cooling technological elements, drift eliminators, water distribution systems, water spray equipments, packings. Building technology, building constructions. Reconstruction of cooling towers. Desirable future of the power economy

1990-06-02

11

Numerical study of coupled heat and mass transfer in geothermal water cooling tower  

International Nuclear Information System (INIS)

Cross flow mechanical cooling towers, widely spreads all over the south region of Tunisia are used for cooling geothermal water for agriculture and domestic ends. These towers are sized empirically and present several problems in regard to operation and electrical energy consumption. This work aims to study the thermal behaviour of this type of cooling towers through a developed mathematical model considering the variation of the water mass flow rate inside the tower. The analysis of the water and air temperatures distribution along the cooling tower had underlined the negative convection phenomenon at a certain height of the tower. This analysis has shown also that the difference in water temperature between the inlet and the outlet of the tower is much higher than the one of air due to the dominance of the evaporative potential compared to the convective one. In addition, the variations of the air humidity along the cooling tower and the quantity of evaporated water have been investigated. The loss of water by evaporation is found to be 5.1% of the total quantity of water feeding the cooling tower. Interesting future prospects are expected for validation of the developed model to optimize the operating of the cooling tower.

2080-01-00

12

Numerical study of coupled heat and mass transfer in geothermal water cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Cross flow mechanical cooling towers, widely spreads all over the south region of Tunisia are used for cooling geothermal water for agriculture and domestic ends. These towers are sized empirically and present several problems in regard to operation and electrical energy consumption. This work aims to study the thermal behaviour of this type of cooling towers through a developed mathematical model considering the variation of the water mass flow rate inside the tower. The analysis of the water and air temperatures distribution along the cooling tower had underlined the negative convection phenomenon at a certain height of the tower. This analysis has shown also that the difference in water temperature between the inlet and the outlet of the tower is much higher than the one of air due to the dominance of the evaporative potential compared to the convective one. In addition, the variations of the air humidity along the cooling tower and the quantity of evaporated water have been investigated. The loss of water by evaporation is found to be 5.1% of the total quantity of water feeding the cooling tower. Interesting future prospects are expected for validation of the developed model to optimize the operating of the cooling tower. (author)

Bourouni, K. [U.R. Energetique des Batiments et Systemes Solaires, Ecole Nationale d' Ingenieurs de Tunis, BP 37, Le Belvedere, 1002 Tunis (Tunisia); Bassem, M.M.; Chaibi, M.T. [Institut National de Recherche en Genie Rural Eaux et Forets, BP 10, Ariana 2080 (Tunisia)

2008-05-15

13

Improve crossflow cooling tower operation  

International Nuclear Information System (INIS)

This paper reports how various crossflow cooling tower elements can be upgraded. A typical retrofit example is presented. In the past decade, cooling tower technology has progressed. If a cooling tower is over ten years old, chances are the heat transfer media and mechanical equipment were designed over 30 to 40 years ago. When a chemical plant expansion is projected or a facility desires to upgrade its equipment for greater output and energy efficiency, the cooling tower is usually neglected until someone discovers that the limiting factor of production is the quality of cold water returning from the cooling tower.

1989-01-01

14

Cooling tower acquitted  

Energy Technology Data Exchange (ETDEWEB)

Considers the problem of Legionnaires' disease in connection with cooling towers, but also draws attention to other sources of infection eg showers, atomised humidification etc. A recent Health and Safety Executive guidance note puts the problem in perspective; 100-200 cases are reported annually in England and Wales. The current split between wet and dry cooling systems for all applications is considered. The most effective way to limit risk is to ensure that cooling towers are properly sited, have good drift eliminators, are frequently cleaned, designed to avoid dead legs and that a water treatment programme including biocides is carefully applied.

Daly, E.

1987-04-01

15

Deuterium- and 18O-content in the cooling water of power station cooling towers  

International Nuclear Information System (INIS)

[en] The 0-18/0-16 and D/H isotope ratios of water from two different cooling towers were determined by mass spectrometry. The observed isotope fractionation corresponds to that known from natural evaporation or transpiration processes: cooling tower I: delta(D) = 46.8 per thousand, delta(18O) = 7.6 per thousand cooling tower II: delta(D) = 33.9 per thousand delta(18O) = 5.7 per thousand Evaluation of simple compartment models of a cooling tower and a distillation device suggests that there exists some isotope discrimination within the open trickling unit of a cooling tower analogous to that in a rectification column. In a real cooling tower, however, this effect is compensated largely by the recycling of the cooling water, resulting only in a small enrichment of the heavy isotopes. This can be understood as the result of three partial effects: 1) a fractionation in the vapor pressure equilibrium, 2) a kinetic effect due to diffusion of the water vapor into a turbulent atmosphere, and 3) an exchange effect which is proportional to relative humidity. This low enrichment of the heavy isotope excludes the technical use of cooling towers as isotope separation devices. (orig.)[de] Die Isotopenverhaeltnisse 0-18/0-16 und D/H im Wasser von zwei verschiedenen Kuehltuermen wurden durch Massenspektroskopie bestimmt. Die beobachtete Fraktionierung der Isotope entspricht derjenigen, die aus natuerlichen Verdampfungs- und Transpirationsprozessen bekannt ist: Kuehlturm I: delta(D) = 46,8 Promille, delta(18O) = 7,6 Promille Kuehlturm II: delta(D) = 33,9 Promille, delta(18O) = 5,7 Promille. Die Auswertung von einfachen Faechermodellen eines Kuehlturms und einer Destillationsvorrichtung laesst darauf schliessen, dass in der offenen Rieseleinheit eines Kuehlturms aehnlich wie bei der in einer Rektifizierkolonne eine gewisse Isotopentrennung stattfindet. In einem wirklichen Kuehlturm wird dieser Effekt jedoch groesstenteils durch die Rezyklierung des Kuehlwassers kompensiert, was zu einer nur geringen Anreicherung der schweren Isotope fuehrt. Dies kann man als das Ergebnis von drei Teileffekten verstehen: 1) einer Fraktionierung im Dampfdruckgleichgewicht, 2) einem kinetischen Effekt aufgrund der Diffusion von Wasserdampf in eine turbulente Atmosphaere hinein und 3) einem Austauscheffekt, der proportional zur relativen Feuchte ist. Diese geringe Anreicherung der schweren Isotope schliesst die technische Anwendung von Kuehlturmen als Isotopentrennvorrichtungen aus. (orig.)

1976-01-01

16

Legionella oakridgensis: unusual new species isolated from cooling tower water.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new spe...

Orrison, L H; Cherry, W B; Tyndall, R L; Fliermans, C B; Gough, S B; Lambert, M A; McDougal, L K; Bibb, W F; Brenner, D J

17

Legionella in cooling towers.  

Science.gov (United States)

Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test). PMID:10281778

Witherell, L E; Novick, L F; Stone, K M; Duncan, R W; Orciari, L A; Kappel, S J; Jillson, D A

18

Legionella in cooling towers.  

UK PubMed Central (United Kingdom)

Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test).

Witherell LE; Novick LF; Stone KM; Duncan RW; Orciari LA; Kappel SJ; Jillson DA

1986-11-01

19

Cooling tower wood deterioration by fungi in the service water system of a test reactor  

International Nuclear Information System (INIS)

Wood deterioration in wet cooling towers is a universal industrial problem. Wood deterioration in the cooling tower has been a problem in the cooling water circuit of a Fast Breeder Test Reactor at Kalpakkam which uses an open recirculation cooling system. Studies on the fungal flora and water quality of the service and source water were carried out to examine the factors responsible for wood deterioration. Data on weight loss following exposures to different fungal species showed that deterioration was more pronounced in the case of aspergillus niger (14%), as compared to others: Penicillium citrinum (11%), pacilomyces sp. (10%) trichoderma viride (8%), aspergillus flavus (9%), A. terreus (11%), and control (6%). (author)

1998-01-01

20

Resonance in the water circuit of a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

During the start-up tests of a cooling-tower circuit pressure resonance took place. With the aid of a mathematical model this resonance was investigated and the results were analyzed. The elastic behavior of leaking non-return valves appeared to be responsible for the onset of the resonance. The preventive function of a by-pass around each valve, was analyzed. In the final start-up test the leakage flow was eliminated and a by-pass had been installed for safety reasons. The measures taken proved to be satisfactory for all operating conditions.

van de Sande, E.; Belde, A.P.; Hamer, B.J.G.; Provoost, G.A.

1983-01-01

 
 
 
 
21

Legionella oakridgensis: unusual new species isolated from cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

A new species of Legionella represented by 10 strains isolated from industrial cooling towers is described. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects, it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis.

Orrison, L.H. (Centers for Disease Control, Atlanta, GA); Cherry, W.B.; Tyndall, R.L.; Fliermans, C.B.; Gough, S.B.; Lambert, M.A.; McDougal, L.K.; Bibb, W.F.; Brenner, D.J.

1983-02-01

22

Evaluation Of Cooling Tower Degradation  

International Nuclear Information System (INIS)

Cooling tower degradation has been evaluated for the last 10 years. Its heat transfer capacity has been decreasing after several years of operation due to aging. Evaluation is carried out by calculating the degradation rate, namely the annual increase of outlet temperatures of the cooling tower. Data was randomly taken daily at 15 MW reactor power. Data was taken after the reactor operation of ± 8 hours. Evaluation since 1990 shows that the degradation rate is nearly one degree per year. This degradation can be by minimized, replacement of damaged components, non-excessive operation and design modification of the cooling tower namely by extending the period of contract between water and air.

2000-01-00

23

Water tower  

CERN Document Server

The water tower, being built on the highest point of the site, 460.5 m above the sea level. The tank will hold 750 m3 of water, and the tower will be topped by a knob which can serve as a geological survey reference mark.

1970-01-01

24

Detection of Legionella pneumophila by PCR-ELISA Method in Industrial Cooling Tower Water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water supply and Cooling Tower Water (CTW) are among the most common sources of Legionella pneumophila (LP) contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene ...

Soheili Majid; Nejadmoghaddam Mohammad Reza; Babashamsi Mohammad; Ghasemi Jamileh; Jeddi Tehrani Mahmood

25

Cooling-water pumps in cooling circuits with wet cooling tower  

International Nuclear Information System (INIS)

[en] The nature of recooling operation influences the delivery head of the cooling-water pumps and their control. According to the cooling-water flow and delivery heads different pump designs are provided. The author describes a number of control alternatives and also gives a survey of the pump designs and the possibilities of their construction and location. (orig.)[de] Die Art des Rueckkuehlbetriebes beeinflusst die Foerderhoehe der Kuehlwasserpumpen und deren Regelung. Abhaengig von den Kuehlwasserstroemen und Foerderhoehen werden unterschiedliche Pumpenbauarten vorgesehen. Der Verfasser beschreibt verschiedenen Regelmoeglichkeiten, ausserdem gibt er einen Ueberblick ueber die Bauarten der Pumpen und deren Ausfuehrungs- sowie Aufstellungsmoeglichkeiten. (orig.)

1976-01-01

26

Hypotheses of calculation of the water flow rate evaporated in a wet cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The method developed by Poppe at the University of Hannover to calculate the thermal performance of a wet cooling tower fill is presented. The formulation of Poppe is then validated using full-scale test data from a wet cooling tower at the power station at Neurath, Federal Republic of Germany. It is shown that the Poppe method predicts the evaporated water flow rate almost perfectly and the condensate content of the warm air with good accuracy over a wide range of ambient conditions. The simplifying assumptions of the Merkel theory are discussed, and the errors linked to these assumptions are systematically described, then illustrated with the test data.

Bourillot, C.

1983-08-01

27

Detection of Legionella spp. in cooling tower water by the polymerase chain reaction method.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The presence of Legionella spp. in cooling tower water was investigated by using the polymerase chain reaction. Total Legionella spp. detection was performed with 20-mer 5S rRNA complementary DNA sequence primers, and specific Legionella pneumophila detection was performed with 20-mer and then 21-me...

Koide, M; Saito, A; Kusano, N; Higa, F

28

Recent developments in cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The last few years have brought about some interesting developments in large cooling towers. Cooling tower technology and research have already been reviewed from the researcher's point of view. The present article describes some practical problems from the planning engineer's point of view. Only development trends in wet natural-draught cooling towers are considered. The shape of cooling towers has been improved as well as their internals. Hints for cooling tower operation are given on the basis of operating experience in winter.

Honekamp, H.; Katzmann, A.

1981-07-01

29

Water cooling towers and Legionella. The practice between now and later; Koeltorens en Legionella. De praktijk tussen nu en later  

Energy Technology Data Exchange (ETDEWEB)

Attention is paid to the management of water cooling towers with respect to those hazards, the status quo of research on the subject in the Netherlands, Dutch and foreign legislation and future expectations.

Kalsbeek, R.G. [A. Kalsbeek - Assen, Assen (Netherlands)

2001-04-01

30

A STUDY ON LEGIONELLA PNEUMOPHILA, WATER CHEMISTRY, AND ATMOSPHERIC CONDITIONS IN COOLING TOWERS AT THE SAVANNAH RIVER SITE  

Energy Technology Data Exchange (ETDEWEB)

Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical, biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant elevated Legionella concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.

Smith, C.; Brigmon, R.

2009-10-20

31

A comparison of legionella and other bacteria concentrations in cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

A field study was conducted in which water samples collected from air conditioning cooling water reservoirs of high-rise buildings throughout an urban area were assayed for Legionella and for total bacteria. Buildings included within the study had ongoing biocidal treatment programs for the cooling towers. Separate sample analyses were performed to measure the viable colony concentrations of total bacteria and of Legionella in the process waters. The occurrence and viable counts of Legionella in 304 environmental water samples were determined by inoculating them onto plates of buffered charcoal yeast extract (BCYE) agar medium (a presumptive screening method). The samples were collected during summer months between July and September. BCYE plate cultures of 50 (16.4%) of the samples yielded Legionella with viable counts ranging from 2 to 608 colony forming units per milliliter. In the water samples, 281 (92.4%) yielded viable counts of bacteria that ranged from 9 to 1.2 x 10{sup 6} per milliliter. This study demonstrates that Legionella are commonly present in the water of air conditioning cooling towers and that there is no significant correlation between concurrently sampled culture plate counts of Legionella and total bacteria plate counts. Correspondingly, there is no demonstrated validity for use of total bacterial counts as an inferential surrogate for the concentration of Legionella in the water. 19 refs., 3 figs., 1 tab.

Cappabianca, R.M.; Jurinski, N.B.; Jurinski, J.B. [NuChemCo, Inc., Annandale, VA (United States)

1994-05-01

32

Cooling tower with forced convection  

International Nuclear Information System (INIS)

Using air or magnetic cushions and linear motor drives, frictional losses as well as noise and wear are reduced, so that a blower of large mass can rotate economically and with high efficiency at the point where the cooling tower diameter is largest. This blower at the basis of the cooling tower consists of an endless blade row between two rotating ring elements of cooling tower diameter. (HP)

1977-01-01

33

Energy conservation strategies, the ignored cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Because of their apparent lack of sophistication, cooling towers are usually considered orphans of the facilities operation. Historically, cooling towers have been neglected in refrigeration air conditioning systems, electric power generating stations, manufacturing plants, and chemical process plants. Operators are aware of the importance of their sophisticated equipment but, they take the apparently simple cooling towers and cold water returning for granted, Since the box looks sturdy and the fans are rotating, the operators think all is well and ignore the quality of water coming off the tower. A cooling tower is purchased for Design Conditions of performance which are specified. Design Conditions relate to the volume of circulating water (GPM), hot water temperature (HWT), cold water temperature (CWT) discharge, and wet bulb temperature (WBT). The WBT consisting of ambient temperature and relative humidity. After the tower is on line and the CWT becomes inadequate, many engineers look to solutions other than the obvious. All cooling towers are purchased to function at 100% of capability in accordance with Design Condition. In the real world of on-stream utilization, the level of operation is lower. It can be deficient as much as 30% due to a variety of reasons which are not necessarily due to the failure of the performance of the tower.

Burger, R.

1997-06-01

34

Optimizing cooling tower performance refrigeration systems, chemical plants, and power plants all have a resource quietly awaiting exploitation - cold water  

International Nuclear Information System (INIS)

The cooling towers are hidden bonanzas for energy conservation and dollar savings when properly engineered and maintained. In many cases, the limiting factor of production is the quality and quantity of cold water coming off the cooling tower. The savings accrued in energy conservation and additional product manufactured can be an important factor on the operator's company's profit and loss sheet (7). Energy management analysis is a very important consideration in today's escalating climate of costs of energy. It is advisable to consider a thorough engineering inspection and evaluation of the entire plant to leave no stone unturned iii the search to reduce energy consumption (8). The cooling tower plays the major role on waste heat removal and should be given a thorough engineering inspection and evaluation by a specialist in this field. This can be performed at nominal cost and a formal report submitted with recommendations, budget costs, and evaluation of the thermal, structural, and mechanical condition of the equipment. This feasibility study will assist in determining the extent of efficiency improvement available with costs and projected savings. It can be stated that practically all cooling towers can be upgraded to perform at higher levels of efficiency which can provide a rapid, cost-effective payback. However, while all cooling tower systems might not provide such a dramatic cost payback as these case histories, the return of a customer's investment in upgrading his cooling tower can be a surprising factor of operation and should not be neglected.

1993-01-01

35

Cooling towers, the money converters  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the losses of revenue/capacity for power plants operating with the cooling tower operating at less than peak performance. The topics of the article include lost generating revenue, nominal cooling towers, importance of wet bulb temperature, and includes two case histories: one of a South American refinery and the other a pharmaceutical company.

Burger, R. [Burger and Associates, Inc., Dallas, TX (United States)

1996-11-01

36

Wet cooling towers: rule-of-thumb design and simulation  

Energy Technology Data Exchange (ETDEWEB)

A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature, power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.

Leeper, S.A.

1981-07-01

37

Top of a cooling tower  

International Nuclear Information System (INIS)

This is a supplement to DP 24 14 172.8 which refers to air slightly in motion, aiming at an improvement of the efficiency of a cooling tower, with the result that the tower's hight can be reduced while keeping up to the same capacity by means of partially lateral screening against mean and major wind velocities. This screening, which can easily be arranged onto and removed from any peripheral section of the cooling tower, is to prevent the upper cooling tower openings to be closed by side-winds passing over them. A pylon in the centre of the cooling tower overlooks its upper edge by several meters. Ropes stretched from the pylon's top to the upper tower periphery form a pyramidal pole. Its lower part may be covered with fabrics and plastics as a screening, stretching from one rope to another. When all areas will be covered they form a closed truncated cone tapering the cooling tower upwards. According to the master patent, they prevent cold air from entering the cooling tower with air slightly in motion. According to the supplement, the screening is rolled up at the side sheltered from the wind when there are major wind velocities. That part remaining at the windward side diverts the wind upwards and waste steam can escape freely on all sides. A control mechanism individually powered for rolling the (plastic or) fabric coverings is described. (HP)

1977-01-01

38

Variations of starting conditions contribution to cooling tower plume predictions  

International Nuclear Information System (INIS)

[en] The paper deals with quantitative contribution of variations of starting conditions to cooling tower plume predictions. The starting conditions are: plume velocity and temperature and concentration of water drops in the plume at the cooling tower outlet. For the same thermal discharge and meteorological conditions, starting conditions are given by characteristics of cooling towers. (author)

1977-01-01

39

Detection of Legionella from Teaching Hospital Cooling Tower Water of Air Conditioning Systems in Eastern Province of Saudi Arabia  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to investigate the frequency of contamination of Legionella in the King Fahd Hospital of the University (KFHU) cooling tower water of air conditioning system and other water supplies. A total of 300 samples were collected from various sites in KFHU. Water samples were collected from the cooling tower (88), hot-shower head (40), cold-shower head (59), engineering building (12) and drinking fountain (12). Swab samples were also collected from shower heads (44) and air ventilator (45). Overall Legionella was detected in only 5 (5.68%) out of 88 water samples and yielded 7 isolates. All other water samples that were collected from other sites were negative for the presence of Legionella. Culturing the hospital water supply for Legionella was the first step in the assessment of the risk for hospital-acquired Legionnaires’ (LD). Legionella is a common cause of hospital-acquired pneumonia, especially for immunocompromised patients.

Nasreldin Elhadi; Hatem Qutub

2012-01-01

40

Legionella anisa: a new species of Legionella isolated from potable waters and a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Between March 1980 and June 1981, five strains of Legionella-like organisms were isolated from water. Four were recovered from potable water collected from hospitals in Chicago, IL, and Los Angeles, CA, during outbreaks of nosocomial legionellosis. The fifth strain was isolated from water collected from an industrial cooling tower in Jamestown, NY. The strains exhibited biochemical reactions typical of Legionella species and were gram-negative motile rods which grew on buffered charcoal-yeast extract agar but not on blood agar, required cysteine, and were catalase positive, urease negative, nitrate negative, hippurate negative, and nonfermentative. All strains were positive for oxidase and beta-lactamase and produced a brown, diffusible pigment. The fatty-acid composition and ubiquinone content of these strains were consistent with those of other Legionella species. Direct fluorescent-antibody examination of the five strains with conjugates to previously described Legionella species demonstrated no cross-reactions except with the conjugates to L. longbeachae serogroup 2 and L. bozemannii serogroup 2. Four strains gave a 4+ reaction to the L. longbeachae serogroup 2 conjugate and the fifth strain gave a 1+ reaction. Each of the five strains gave a 4+ reaction with the conjugate to L. bozemanii serogroup 2. DNAs from the five strains were highly related (84 to 99%) and showed 5 to 57% relatedness to other Legionella species. These strains constitute a new species in the genus Legionella, and the name Legionella anisa sp. nov. is proposed.

Gorman, G.W.; Feeley, J.C.; Steigerwalt, A.; Edelstein, P.H.; Moss, C.W.; Brenner, D.J.

1985-02-01

 
 
 
 
41

Construction and function of the flue-gas desulphurisation system integrated in the cooling tower with flue-gas outlet and cooling water recooling  

Energy Technology Data Exchange (ETDEWEB)

After the electrostatic filter the flue gases are transported via a suction draught and a rectangular channel to the flue gas desulphurisation plant installed in the cooling tower where they are distributed to vertical scrubbing tubes. A slightly alcalic scrubbing solution consisting of Ca(OH/sub 2/) and Ca(HCOO/sub 2/) and CaCl/sub 2/ washes the flue gases in parallel flow. The desulphurised flue gases are separated from the water by means of deflection and mist collectors and mixed to the cooling tower plumes via flue gas chimneys. The formation of CaSO/sub 3/ prevents pH-value control.

Eckel, H.

1983-01-01

42

Cooling towers criticised in legionella inquiry  

Energy Technology Data Exchange (ETDEWEB)

Air conditioning plant in hundreds of British hospitals provides an ideal place for the bacteria that cause legionnaires' disease to breed and spread. So concludes a report into last year's outbreak of the disease at Stafford disrict general hospital, in which at least 28 people died. Legionella bacteria breed in lukewarm water, feeding on organic detritus. They are widely found, but only become dangerous if they are breathed in. For this reason fine sprays of water containing the bacteria are especially potent sources of the disease. Many air-conditioning systems in large institutions such as hospitals use water sprays in cooling towers to dissipate heat removed from air by chillers during warm weather. At Stafford, the cooling tower was close to the air inlet for the air conditioning system. So, when conditions became right for the bacteria to breed prolifically in the cooling tower, the bacteria were sucked into the air-conditioning system and spread through the hospital. Most of the deaths occurred among people who had attended the outpatients' clinic. The cooling tower and inlets for fresh air for the air-conditioning system, which were immediately below the cooling tower, were not separated. Once the air in the cooling tower had become contaminated with the infected spray of water, there was nothing to prevent this air from being circulated to the outpatients' department. Government guidelines say that hot water should be above 50/sup 0/C and cold water below 20/sup 0/C to inhibit the growth of bacteria causing legionnaires' disease. The bacteria multiply best at temperatures between 20 and 45/sup 0/C.

1986-06-12

43

Frost protection for atmospheric cooling tower  

International Nuclear Information System (INIS)

When the atmospheric temperature is near or lower than zero it is necessary to reduce the air flow entering in a cooling tower. A wire netting mounted on the air inlet is sprinkled with cold water. The level of the ice curtain and consequently the air flow is regulated by aspersion by hot water

1986-04-30

44

Energy savings in cooling tower packings  

Energy Technology Data Exchange (ETDEWEB)

The cooling tower packing, also called fill or contact media, where the heat and moisture transfer and the related cooling of the water take place, is the heart of the cooling tower. The share of the packing in the total cost of the tower is normally only 10-20%, depending on type and size of cooling tower. Thus, enough emphasis is not always placed on the importance of the selection of the packing. This is due to the fact that the relationship between the efficiency of the packing and the size of the tower is not always adequately considered. This paper shows how a high-efficiency film-type fill considerably reduces the required cross-section and the first cost of a counterflow tower. The actual value of the savings obtained by using a high-efficiency film-type fill can be measured by its so-called limit value, which will be several times higher than its actual cost. Energy balance and cost calculations are presented for three examples from industrial practice. 3 refs.

Skold, J.O.

1981-10-01

45

Legionella pollution in cooling tower water of air-conditioning systems in Shanghai, China.  

UK PubMed Central (United Kingdom)

AIMS: To determine Legionella pollution prevalence, describe the amount of Legionellae with respect to temperature in Shanghai cooling tower water (CTWs) in various types of public sites. METHODS AND RESULTS: Six urban districts were selected as the study fields, adopting multiple-phase sampling methods. Routine culture was used to identify Legionellae. Of the samples, 58.9% (189/321) were observed to be positive, 19.9% were isolated over 100 CFU ml(-1). Legionella pneumophila serogroup 1 was the most frequently isolated species (155/189, 82.0%), followed by Leg. micdadei that was at the second place (44/189, 23.3%). The mean CFU ml(-1) of Legionellae in CTWs reached its peak from July to September. Over all 15.4% of the samples exceeding 100 CFU ml(-1) were observed in a hospital setting. CONCLUSIONS: The prevalence of Legionella pollution in CTWs, especially in CTWs of subway stations and hospitals, is worrying, and the positive rate and CFU ml(-1) of Legionellae in CTWs have a close relationship with air temperature. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates pollution prevalence rates in different types of sites and various seasons, and provides a proportion of different serogroups of Legionellae. It illuminates an urgent need for dealing with the potential risk of legionellosis in Shanghai, through improved control and prevention strategies.

Lin H; Xu B; Chen Y; Wang W

2009-02-01

46

Improved facility and sensitivity in the use of guinea pigs for the isolation of Legionella pneumophila from cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

The established criteria for the determination of the optimum time for the sacrifice of guinea pigs inoculated with samples of cooling tower water were found to be inadequate for the detection of low levels of Legionella pneumophila. By ignoring the requirement for fever and by sequentially sacrificing the infected guinea pigs on days 3 through 5 postinoculation, we simplified the procedure, and the sensitivity of detection was improved a great deal.

Leinbach, E.D.; Winkler, H.H.; Wood, D.O.; Coggin, J.H. Jr.

1983-03-01

47

Understanding cooling towers: The route to energy savings  

Energy Technology Data Exchange (ETDEWEB)

In order to save operating costs for cooling towers it is important to know how and where energy is used in the tower. A cooling tower uses electrical energy in two areas. The pump that circulates the water through the cooling tower and the heat exchanger loop is the first user. In order to reduce energy consumption one must either reduce the volume of water pumped or the resistance to flow. The second user of power is the fan. Like the water pump, either the volume of air or the resistance to flow must be reduced in order to save energy. The early water cooling towers were very simple devices. They were put together with locally available materials with very few engineering calculations and only a few crude rules of thumb to estimate the thermal capacity. While modern towers operate on the same principles as the early towers, the cooling process is much better understood and the thermal capacity of a new tower can be predicted to within 1%. Probably the biggest overall difference between the modern tower and the tower of the past is the capability of getting much more cooling out of a smaller package with less energy usage. In order to achieve this higher level of performance, the various components of the tower have been refined and fine tuned to work together as a coherent system.

Smith, M.

1987-01-01

48

Application of Response Surface Methodology (RSM) for Optimization of Operating Parameters and Performance Evaluation of Cooling Tower Cold Water Temperature  

Directory of Open Access Journals (Sweden)

Full Text Available The performance of a cooling tower was analyzed with various operating parameters tofind the minimum cold water temperature. In this study, optimization of operating parameters wasinvestigated. An experimental design was carried out based on central composite design (CCD) withresponse surface methodology (RSM). This paper presents optimum operating parameters and theminimum cold water temperature using the RSM method. The RSM was used to evaluate the effectsof operating variables and their interaction towards the attainment of their optimum conditions.Based on the analysis, air flow, hot water temperature and packing height were high significanteffect on cold water temperature. The optimum operating parameters were predicted using the RSMmethod and confirmed through experiment.

Ramkumar RAMAKRISHNAN; Ragupathy ARUMUGAM

2012-01-01

49

Modeling of Direct Contact Wet Cooling Tower in ETRR-2  

International Nuclear Information System (INIS)

The Egyptian Testing and Research Reactor no.2 (ETRR-2) was commissioned at 1997 with maximum power 22 MW for research purposes; an induced draft wet cooling tower (counter flow type) was putted in operation in 2003 instead of the first one. Investigations are achieved to evaluate cooling tower performance to guarantee that the cooling tower capable to dissipate heat generated in reactor core. Merkel and Poppe analysis was applied to simulate this cooling tower packing. Merkel analysis was applied to predict water outlet temperature from cooling tower and also to show the effect of ambient conditions on this temperature. Poppe analysis was applied to predict Merkel number which evaluate cooling tower. The Runge-Kutta numerical method was applied to solve the differential equations in this model and an engineering equation solver (EES) is the language used to model the cooling tower. This research illustrates that the cooling tower achieves good performance in various sever ambient condition at maximum operating condition of reactor power. The results show that at severe summer condition of wet bulb temperature equals 24 degree c and tower inlet temperature equals 37 degree c, the outlet water temperature equals 30.4 degree c from cooling tower, while the Merkel number is be found 1.253

2008-01-01

50

PERFORMANCE ANALYSIS OF MECHANICAL DRAFT COOLING TOWER  

Energy Technology Data Exchange (ETDEWEB)

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT's consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

2009-02-10

51

Plant Vogtle cooling tower studies  

Energy Technology Data Exchange (ETDEWEB)

Intensive ground-based field studies of plumes from two large, natural-draft cooling towers were conducted in support of the MTI modeling effort. Panchromatic imagery, IR imagery, meteorological data, internal tower temperatures and plant power data were collected during the field studies. These data were used to evaluate plume simulations, plume radioactive transfer calculations and plume volume estimation algorithms used for power estimation. Results from six field studies indicate that a 3-D atmospheric model at sufficient spatial resolution can effectively simulate a cooling tower plume if the plume is of sufficient size and the ambient meteorology is known and steady. Small plumes and gusty wind conditions degrade the agreement between the simulated and observed plumes. Thermal radiance calculations based on the simulated plumes produced maximum IR temperatures (near tower exit) which were in good agreement with measured IR temperatures for the larger plumes. For the smaller plumes, the calculated IR temperature was lower than the measured temperature by several degrees. Variations in maximum IR plume temperature with decreasing power (one reactor was undergoing a shutdown process), were clearly observed in the IR imagery and seen in the simulations. These temperature changes agreed with those calculated from an overall tower energy and momentum balance. Plume volume estimates based on camcorder images at three look angles were typically 20--30 percent larger than the plume volumes derived from the simulations, although one estimate was twice the simulated volume. Volume overestimation is expected and will have to be accounted for to some degree if plume volume is to be a useful diagnostic quantity in power estimation. Volume estimation with MTI imagery will require a large, stable plume and two looks in the visible bands (5m GSD) along with a solar shadow.

O' Steen, L.

2000-01-26

52

Legionella in Puerto Rico cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.

Negron-Alviro, A.; Perez-Suarez, I.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico)

1988-12-31

53

Legionella spp. in Puerto Rico cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, P.R., were assayed for various Legionella spp. and serogroups by using direct immunofluorescence. Several water quality parameters were also measured for each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila serogroups 1 to 6, L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species; its density reached 10{sup 5} cells per ml, which is within the range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (acridine orange direct count) were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems and that, without continuous biocide treatment, they may reach densities that present a health risk.

Negron-Alvira, A.; Perez-Suarez, I.; Hazen, T.C. (Univ. of Puerto Rico, Rio Piedras (Puerto Rico))

1988-10-01

54

Response of corn and soybeans to simulated saline aerosol drift from brackish water cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Field studies were conducted on corn (Zea mays L.) and soybeans (Glycine max (L.) Merr.) for 8 weeks during each summer from 1973 to 1977 to acquire information on the response of these crops to saline aerosol deposition from brackish water cooling towers. The studies involved two sources of Chalk Point, Md.) and various salt deposition rates (0.97-22.24 kg ha/sup -1/ week/sup -1/). Soybeans exhibited greater sensitivity than corn to simulated saline aerosol drift early in their growth cycle, but corn yields were impacted more than soybean yields from the foliar salt treatments. Vegetative symptoms of salt injury on corn were progressively more pronounced as the plants matured than was the case with soybeans. Polynomial regression analyses of yields vs. salt deposition rates produced linear relationships for both crops. Corn yields were described by the relationship Y/sub c/ = 97.9-1.94X and soybean yields by the relationship Y/sub sb/ = 103.5-1.73X, where X equaled the rate of salt deposition, and yields (Y) were expressed as percent of nontreated controls. Changes in leaf Cl levels in corn in response to foliar-applied salts were described by the relationship Y = 0.20 + 0.07X - 0.001X/sup 2/, and leaf Na contents by the relationship Y = 0.099 + 0.024X. Changes in leaf Cl levels in soybeans in response to foliar-applied salts were described by the relationship Y = 0.059 + 0.073X + 0.004X/sup 2/ - 0.0004X/sup 3/, and leaf Na levels by the relationship Y = 0.086 + 0.011X + 0.0006X/sup 2/, where X equaled the salt deposition rate (kg ha/sup -1/ week/sup -1/) and Y equaled the element contents (%). In an effort to explore methods for assessing the levels of crop yield reductions in areas where salt deposition is suspected but no control plants are possible, corn yields were described by the relationship Y/sub c/ = 105 - 35.5X/sub 1/ and Y/sub c/ = 102 - 63.7X/sub 2/, where Y/sub c/ equaled the percent of nontreated controls, and X/sub 1/ and X/sub 2/ equaled the Cl and Na contents (%), respectively.

Mulchi, C.L.; Armbruster, J.A.

1981-10-01

55

Vortex-augmented cooling tower-windmill combination  

Science.gov (United States)

A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passages to provide power as a by-product.

McAllister, Jr., John E. (Aiken, SC)

1985-01-01

56

Bacterial aerosols produced from a cooling tower using wastewater effluent  

Energy Technology Data Exchange (ETDEWEB)

A cooling tower, which receives make-up water from a municipal wastewater treatment plant, was studied. Wastewater effluent was super-chlorinated, then treated with lime and a commercial coagulant to remove phosphates, calcium, magnesium, and suspended solids before it was pumped into the cooling tower. The chlorination and coagulation described above were used to reduce deposition of scale and slime on the power plant condenser surfaces. Bacterial counts were made of the cooling tower basin waters and of the aerosols exiting the cooling tower vents. It was dicovered that 39% of bacteria exiting the cooling tower vents were of the genus Pseudomonas. A few pathogenic microbes were also found to be present in the aerosolized particles but their numbers were so low that they were considered insignificant.

Adams, A.P.; Garbett, M.; Rees, H.B.; Lewis, B.G.

1980-03-01

57

[Microbial emission, immission and changes in the germ count in the cooling water during operation of wet cooling towers III. communication: laboratory tests for the determination of the reduction kinetics of Escherichia coli in cooling tower plumes (author's transl)].  

Science.gov (United States)

The present paper reports on laboratory tests for the determination of the reduction rate of micro-organisms. The investigations were carried out with a pure culture of E. coli, a germ type from the enterobacterial group. By a suitable variation of the thermodynamic parameters it was possible to simulate the conditions through which the cooling tower plume passes inside the chimney of the cooling tower and when it mixes with ambient air. The results allow the following changes in the germ counts in the plume of a wet cooling tower to be expected: 1. As long as the cooling tower plume contains droplets, the capacity of the carried germs to form colonies does not change materially. 2. In the case of unsaturated plumes we must distinguish between two situations: a) The tests in which the germ suspension was sprayed into unsaturated air without any admixture of secondary air, did not demonstrate any dependence of the reduction rate on the relative humidity. b) In contrast to this, the tests in which the germ-carrying droplets were evaporated by admixing a stream of unsaturated secondary air, showed that the capacity to form colonies clearly decreased with diminishing relative air humidity. Case b) is of importance for the dissemination and immission of germs from cooling towers, because here, too, the visible plume initially laden with drops is dried by the admixture of unsaturated ambient air. PMID:388949

Baer, E; Billing, J; Ernst, G; Werner, H P; Wurz, D

1979-09-01

58

The effect of civil engineering and access conditions on the cooling water pumps and the various types of cooling water pumps for cooling towers  

International Nuclear Information System (INIS)

[en] Starting with the pump inlet construction one can see that the designer must decide early on between the acceleration bend and the inlet chamber. To achieve smooth flow, four main conditions must be largely fulfilled. The rotor of cooling tower pumps is usually of the semiaxial type, where one must distinguish between non-adjustable, settable and adjustable rotors. The cooling tower pumps for drain and recirculation cooling are preferably made as spiral casing pumps. For nominal sizes of 1600 and larger, the pump casings are made of concrete, for economic reasons. For combined cooling, the type of pipe casing is decided for the same reasons. The above nominal size limit again decides a conrete design. Of the well-known control processes, the pre-rotor and rotor blade adjustment are at present the most economical. Both types of control are compared. (orig.)[de] Beginnend mit dem Pumpeneinlaufbauwerk ist festzustellen, dass der Planer sich fruehzeitig zwischen dem Beschleunigungskruemmer und der Einlaufkammer entscheiden muss. Zur Erzielung einer stoerungsfreien Zustroemung muessen vier wesentliche Bedingungen weitgehend erfuellt werden. Das Laufrad von Kuehlturmpumpen ist in der Regel von halbaxialer Bauart, wobei noch zwischen nicht verstellbaren, einstellbaren und verstellbaren Laufraedern zu unterscheiden ist. Die Kuehlturmpumpen fuer die Ablauf- und Rueckkuehlung werden vorzugsweise als Spiralgehaeusepumpen ausgefuehrt; bei Nennweiten 1600 und groesser bestehen die Pumpengehaeuse aus Wirtschaftlichkeitsgruenden aus Beton. Bei dem kombinierten Kuehlbetrieb bietet sich aus denselben Gruenden die Rohrgehaeusebauart an; auch hier gilt die oben angegebene Nennweitengrenze fuer die Betonausfuehrung. Von den bekannten Regelverfahren sind z.Z. bei Kuehlturmpumpen die Vorleitrad- und Laufschaufelverstellung am wirtschaftlichsten. Beide Regelarten werden miteinander verglichen. (orig.)

1977-01-01

59

Wet or wet/dry cooling tower  

International Nuclear Information System (INIS)

A wet or wet/dry cooling tower is described having heat exchanger elements to provide heat exchange between water and cooling air and having an arrangement for transferring the cooled water to a return to the water distribution, the same having below the heat exchanger elements a number of adjacent inclined run-off surfaces, water-guiding plates into which the bottom longitudinal edges of the run-off surfaces merge, the plates having vertical areas and having channels which are disposed one above another and which extend transversely of the substantially vertical cooling-air flow, and water-collecting troughs which are disposed perpendicularly to the water-guiding plates at the bottom end of the lateral vertical edges of such plates, the run-off surfaces covering the distance between two adjacent water-guiding plates, the channels extending at an inclination to the horizontal and terminating in lateral vertical edges of such plates, characterised in that the run-off surfaces are connected by way of edged or rounded transition zones to the surface zones of the water-guiding plates and the channels are embodied by guide-groove structures which are stamped out of the surface zones at least on one side and which supply at least from the transition zones the cooling water from the run-off surfaces to the water-collecting troughs with the use of the surface tension of such water. 10 figs

1984-05-29

60

Pilot scale cooling tower fouled fill treatment: AFCATT (Anti-Fouling Chemical Additive Test Tower)  

Energy Technology Data Exchange (ETDEWEB)

Polyvinylchloride (PVC) film-type cellular fill is the fill of choice in replacing cement asbestor board fill in existing cooling towers and in new cooling towers because of its high thermal performance, ease of installation, and low initial cost. However, PVC fill has been found to foul quickly with biological and sediment material, significant reducing tower performance and the fill`s useful life. The Anti-Fouling Chemical Additives Test Tower (AFCATT) has been built to study accumulation rates of fouling deposits in corrugated PVC film fill and to study methods of cleaning and preventing the fouling deposits. This small mechanical draft cooling tower is located next to the Unit 4 natural draft cooling tower at Georgia Power Company`s Plant Bowen. The once-through mechanical draft tower receives hot water from the condenser and returns the cold water to the basin of the host tower. The pilot tower is divided into four chambers allowing for three different treatment programs and one control to be run simultaneously. PVC fill packs are suspended from load cells to allow the weight of the fill packs to be measured continuously. Six vendors participated in the summer 1993 test program. Each proposed different methods of cleaning the fouled fill and were given the opportunity to try their proposed method of fill cleaning. The success of each treatment program was determined by its ability to reduce fill pack weight (i.e., reduce fouling).

Newton, M.T.; Noble, R.T.; Philpot, E.F.; Eastis, J.H. [Southern Company Services, Birmingham, AL (United States)

1995-02-01

 
 
 
 
61

New process for evaporating cooling tower blowdown demonstrated  

Energy Technology Data Exchange (ETDEWEB)

A successful demonstration of a new process for evaporating cooling tower blowdown will compensate for the use of sewage water for cooling at Nevada Power Co.'s Sunrise station, where a new method was needed to concentrate and dispose of waste water. Heat is extracted from the cooling system by a falling-film heat exchanger and used to evaporate the waste water. The binary cooling tower (BCT) process is patented. Possible alternatives will be explored before a full-scale system is installed at Sunrise. The process is described, accompanied by schematic drawings. (DCK)

Slate, R.; Zeien, C.; Sanderson, W.

1980-05-01

62

The effects of natural winds on cooling towers  

International Nuclear Information System (INIS)

Natural winds can affect both the thermal performance and structural design of cooling towers. From the thermal performance viewpoint the severity of wind effects is dependent upon the type of cooling tower being considered. In general, natural winds can cause stripping of falling water near the peripherary of the air inlet, reversal of the airflow into the tower and changes in the recooled water temperature. In the context of C.E.G.B. experience, these effects will be discussed with particular regard to remedial measures and predictive methods. From the structural design viewpoint the effects of natural winds are very important. It has been established that the shells of cooling towers vibrate at their resonant frequencies due to the turbulent nature of the incident wind. Consequently, in evaluating the wind induced stresses in cooling tower shells, it is essential to consider not only the static and quasi-static response of the shell but also its resonant response. As the fluctuating wind loading distribution on the surface of a cooling tower on a particular site cannot be defined explicitly at this time, it is necessary to evaluate wind induced stresses in a shell of a proposed design using wind tunnel test results appropriate to the site under consideration. The development of these wind tunnel test techniques and the results obtained for a typical C.E.G.B. cooling tower installation will be discussed

1975-10-06

63

Optimization of cooling tower performance analysis using Taguchi method  

Directory of Open Access Journals (Sweden)

Full Text Available This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression were carried out in order to determine the effects of process parameters on cooling tower effectiveness and to identity optimal factor settings. Finally confirmation tests verified this reliability of Taguchi method for optimization of counter flow cooling tower performance with sufficient accuracy.

Ramkumar Ramakrishnan; Ragupathy Arumugam

2013-01-01

64

Experimental study of cooling tower performance using ceramic tile packing  

Directory of Open Access Journals (Sweden)

Full Text Available Deterioration of the packing material is a major problem in cooling towers. In this experimental study ceramic tiles were used as a packing material. The packing material is a long life burnt clay, which is normally used as a roofing material. It prevents a common problem of the cooling tower resulting from corrosion and water quality of the tower. In this study, we investigate the use of three different types of ceramic packings and evaluate their heat and mass transfer coefficients. A simple comparison of packing behaviour is performed with all three types of packing materials. The experimental study was conducted in a forced draft cooling tower. The variations in many variables, which affect the tower efficiency, are described.

Ramkumar Ramkrishnan; Ragupathy Arumugam

2013-01-01

65

Performance characteristics of counter flow wet cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are one of the biggest heat and mass transfer devices that are in widespread use. In this paper, we use a detailed model of counter flow wet cooling towers in investigating the performance characteristics. The validity of the model is checked by experimental data reported in the literature. The thermal performance of the cooling towers is clearly explained in terms of varying air and water temperatures, as well as the driving potential for convection and evaporation heat transfer, along the height of the tower. The relative contribution of each mode of heat transfer rate to the total heat transfer rate in the cooling tower is established. It is demonstrated with an example problem that the predominant mode of heat transfer is evaporation. For example, evaporation contributes about 62.5% of the total rate of heat transfer at the bottom of the tower and almost 90% at the top of the tower. The variation of air and water temperatures along the height of the tower (process line) is explained on psychometric charts.

Khan, Jameel-Ur-Rehman; Yaqub, M.; Zubair, Syed M. E-mail: smzubair@kfupm.edu.sa

2003-08-01

66

Theoretical and experimental analyses of cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are used in many HVAC and industrial applications for heat rejection purposes. This paper presents a quick method for estimating the size and performance of forced draft countercurrent cooling towers. A practical and realistic tentative technique is introduced and compared with experimental results. The predictions appear to be helpful to designers of cooling towers. An interactive computer code is developed for illustrating the theoretical predictions. Experimental results obtained, together with those available in the current literature, were used to validate the prediction formulations developed.

Soeylemez, M.S.

1999-07-01

67

Dry cooling tower operating experience in the LOFT reactor  

International Nuclear Information System (INIS)

A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features

1980-08-22

68

Dry cooling tower operating experience in the LOFT reactor  

Energy Technology Data Exchange (ETDEWEB)

A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features.

Hunter, J.A.

1980-01-01

69

Different types of cooling towers influence the design and the conditions of the inlet of cooling water pumps  

International Nuclear Information System (INIS)

[en] Possible solutions of performance and number of cooling water pumps to be installed for 300 mw conventional to 2000 mw nuclear unit powers are shown. As four influencing parameters greatly vary, each pump is individually manufactured. The specific fast-running pumps are sensitive to disturbances on the suction side. 11 examples for the useful shape of chambers and arched beams of the inlet building are given according to their importance. Characteristic and proved inlet chamber types were determined by electron-analog tests and model tests. What one understands by non-destructive flow to the pumps, is determined by means of four criteria, e.g. cavitation and NPSH value (net positive suction head) or according to DIN 'Haltedruckhoehe'. As all four criteria cannot be fulfilled to a maximum, one must be able to decide between them. The constructions of cooling water pumps, pipe and spiral casing with variation are treated in nine examples. Finally, the types of control are discussed. Construction and fabrication of a single cooling pump for a 1300 mw unit would be possible today; pressure joints diameter 4500 mm. (orig.)[de] Fuer Blockleistungen von 300 MW konventionell bis 2000 MW nuklear werden Loesungsmoeglichkeiten fuer Leistung und Anzahl der einzusetzenden Kuehlwasserpumpen aufgezeigt. Da vier Einflussgroessen stark variieren, erfolgt Herstellung in Einzelfertigung. Die spezifisch schnellaeufigen Pumpen sind empfindlich gegen Stoerungen auf der Saugseite. Entsprechend der Bedeutung von Kammern und Kruemmern des Einlaufbauwerkes werden hier 11 Beispiele fuer deren zweckmaessige Gestaltung dargestellt. Charakteristische und bewaehrte Einlaufkammertypen wurden durch Elektroanalogversuche und durch Modellversuche ermittelt. Was als stoerungsfreie Zustroemung zu den Pumpen zu verstehen ist, wird anhand von vier Kriterien ermittelt, z.B. Kavitation und z.B. NPSH-Wert (net positive suction head) oder nach DIN 'Haltedruckhoehe'. Da nicht alle vier Kriterien maximal gut erfuellt werden koennen, muss optimal zwischen ihnen entschieden werden. An neun Beispielen sind die Bauarten von Kuehlwasserpumpen behandelt, Rohr und Spiralgehaeuse mit Variationen. Abschliessend Besprechung von Regelungsarten. - Konstruktion und Fertigung einer einzigen Kuehlwasserpumpe fuer einen 1300-MW-Block waere heute durchfuehrbar; Druckstutzen-Durchmesser 4500 mm. (orig.)

70

Saving of time in acid-cleaning a large boiler by using the cooling tower pond as a demineralized water storage container  

Energy Technology Data Exchange (ETDEWEB)

One of the possibilities for carrying out the cleaning of the water-steam circuit prior to admission of steam to the turbine is to acid-clean the plant with hydrofluoric acid in the forced-flow process without blow-out and consequently with by-pass operation. The paper reports how the uncovered cooling tower pond was used for the storage of demineralized water at Voitsberg No. 3 Power Plant after the appropriate preliminary tests had been carried out.

Ebersold, W.; Schlizio, H.

1984-02-01

71

MATHEMATICAL MODELING OF EMISSIONS FROM COOLING TOWERS USING COAL GASIFICATION WASTEWATER  

Science.gov (United States)

The report describes a computer program that calculates atmospheric emissions from counterflow cooling towers when using pretreated coal gasification wastewaters as tower makeup water. Air stripping and biological oxidation are both incorporated into the mathematical model as pos...

72

Origin and prevention of infection with Legionella pneumophila through cooling towers and evaporative cooling towers  

International Nuclear Information System (INIS)

[en] Evaporative cooling towers and industrial ventilator cooling towers have repeatedly been described as the origin of Legionnaires' disease. This article describes the design and function of cooling towers and evaporative cooling towers, sums up knowledge on the colonization of such systems with Legionella pneumophila, and describes conditions permitting the transmission of Legionella. Furthermore, design, maintenance, cleaning and disinfection measures are indicated which are believed to reduce the risk of infection through industrial and evaporative cooling towers. (orig.)[de] Rueckkuehlwerke klimatechnischer Anlagen und industrielle Ventilator-Kuehltuerme sind mehrfach als Ausgangspunkt von Legionellose-Epidemien beschrieben worden. In der vorliegenden Arbeit werden Aufbau und Funktion von Kuehltuermen und Rueckkuehlwerken erlaeutert, Erkenntnisse ueber die Besiedlung dieser Anlagen mit Legionellen zusammengefassten und die Situationen geschildert, in denen es zur Uebertragung von Legionellen kam. Darueber hinaus werden Konstruktions-, Wartungs-, Reinigungs-, und Desinfektionsmassnahmen aufgefuehrt, die zur Verminderung des Infektionsrisikos durch Kuehltuerme und Rueckkuehlwerke als wirksam angesehen werden. (orig.)

1994-01-01

73

Legionella pneumophila in cooling water systems. Report of a survey of cooling towers in London and a pilot trial of selected biocides.  

UK PubMed Central (United Kingdom)

Fourteen recirculating cooling water systems were surveyed during the summer, 1981, to see what factors might influence the prevalence of Legionella pneumophila. The effect on the organism of three anti-microbials was studied, each in two systems, by intermittent treatment at two week intervals. L. pneumophila was isolated from six of the 14 cooling systems at the beginning of the trial but by the end was present in ten. An association was found between the presence of the organism and the concentration of dissolved solids, and chlorides and the pH. There also appeared to be associations with exclusion of light and higher water temperatures. Repeated tests on eight untreated systems showed that two were consistently infected, three became and remained infected, one was infected on a single occasion and two were never infected with L. pneumophila. Treatment of a contaminated system, either with a 10 p.p.m mixture of a quaternary ammonium compound and tributyltinoxide or slow release chlorine briquettes (maximum recorded free chlorine level 1.2 p.p.m.), did not eliminated legionellae. Treatment of two infected towers with a chlorinated phenol (100 p.p.m.) eliminated legionellae for at least three days, but after 14 days the organism was again found.

Kurtz JB; Bartlett CL; Newton UA; White RA; Jones NL

1982-06-01

74

Reducing the risk of Legionnaires' disease associated with cooling towers  

Energy Technology Data Exchange (ETDEWEB)

To reduce the health and legal risks associated with Legionnaires' disease, facility managers should take steps to minimize Legionella bacteria in plumbing systems, open industrial equipment, water features, cooling towers, and other aerosolizing water systems. The risk of Legionnaires' disease associated with cooling towers can be reduced by controlling Legionella bacteria in cooling water and preventing transmission of the bacteria from towers to people. This paper presents nine reasonable ways to accomplish these goals. (orig.)

Freije, M.R. [HC Information Resources Inc., Carlsbad, CA (United States)

2008-08-15

75

Response of cooling towers to wind loads  

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with the study of two cooling towers of 122 m and 200 m high above ground level. These cooling towers have been analysed for wind loads using ANSYS software by assuming fixity at the shell base. The wind loads on these cooling towers have been calculated in the form of pressures by using the circumferentially distributed design wind pressure coefficients as given in IS: 11504 - 1985 code [1] along with the design wind pressures at different levels as per IS:875 (Part 3) - 1987 code [2]. The analysis has been carried out using 8-noded shell element (SHELL 93) with 5 degrees of freedom per node. The results of the analysis include membrane forces, viz., meridional force (Nf) and hoop force (Nq), and bending moments, viz., meridional moment (Mf) and hoop moment (Mq). The vertical distribution of membrane forces and bending moments along 0o and 70o meridians and the circumferential distributions at base, throat and top levels have been studied for both the cooling towers. For circumferential distribution, non-dimensional values have been obtained by normalizing the membrane forces and bending moments using the reference values at 0o meridian. Similarly, the reference values at the base have been used for vertical distribution. These non-dimensional curves for both the cooling towers have been compared in the present study for the feasibility of any generalisation.

G. Murali; C. M. Vivek Vardhan; B. V. Prasanth Kumar Reddy

2012-01-01

76

Investigation of N-acyl homoserine lactone (AHL) molecule production in Gram-negative bacteria isolated from cooling tower water and biofilm samples.  

UK PubMed Central (United Kingdom)

In this study, 99 Gram-negative rod bacteria were isolated from cooling tower water, and biofilm samples were examined for cell-to-cell signaling systems, N-acyl homoserine lactone (AHL) signal molecule types, and biofilm formation capacity. Four of 39 (10 %) strains isolated from water samples and 14 of 60 (23 %) strains isolated from biofilm samples were found to be producing a variety of AHL signal molecules. It was determined that the AHL signal molecule production ability and the biofilm formation capacity of sessile bacteria is higher than planktonic bacteria, and there was a statistically significant difference between the AHL signal molecule production of these two groups (p < 0.05). In addition, it was found that bacteria belonging to the same species isolated from cooling tower water and biofilm samples produced different types of AHL signal molecules and that there were different types of AHL signal molecules in an AHL extract of bacteria. In the present study, it was observed that different isolates of the same strains did not produce the same AHLs or did not produce AHL molecules, and bacteria known as AHL producers did not produce AHL. These findings suggest that detection of signal molecules in bacteria isolated from cooling towers may contribute to prevention of biofilm formation, elimination of communication among bacteria in water systems, and blockage of quorum-sensing controlled virulence of these bacteria.

Haslan E; Kimiran-Erdem A

2013-09-01

77

Wet/dry cooling tower and method  

Energy Technology Data Exchange (ETDEWEB)

A wet/dry cooling tower wherein a liquid to-be-cooled is flowed along channels of a corrugated open surface or the like, which surface is swept by cooling air. The amount of the surface covered by the liquid is kept small compared to the dry part thereof so that said dry part acts as a fin for the wet part for heat dissipation.

Glicksman, Leon R. (Lynnfield, MA); Rohsenow, Warren R. (Waban, MA)

1981-01-01

78

Cooling towers and legionella; Koeltorens en legionella  

Energy Technology Data Exchange (ETDEWEB)

A brief description is given of the principle of cooling towers, the prevention of legionella in cooling towers, and related regulations. Also the intermediate results of a survey on open cooling towers in the Rotterdam area are presented. Finally, attention is paid to the procedure to handle cases in which legionella has been detected. [Dutch] Jaarlijks vinden er op de wereld epidemieen van legionellose plaats, veroorzaakt door open koeltorens. in dit artikel wordt achtereenvolgens een korte beschrijving gegeven van het werkingsprincipe van koeltorens; de relatie tussen koeltorenbeheer en legionella in open koeltorens; en de huidige stand van zaken op het gebied van regelgeving. Daarnaast worden tussentijdse resultaten van een in Rotterdam gestarte inventarisatie van open koeltorens gegeven. Tenslotte wordt de procedure uiteengezet van de aanpak bij ziektegevallen waarbij legionellose wordt geconstateerd.

Schalekamp, J.D. [Afdeling Medische Milieukunde, Gemeentelijke Gezondheidsdienst voor Rotterdam en omstreken, Rotterdam (Netherlands)

2003-03-01

79

Corrosion control studies in a mini cooling tower  

International Nuclear Information System (INIS)

Generally, raw water is used for cooling the condensers in packaged air conditioning (AC) units installed in separate buildings. These AC units and their cooling water systems are operated on as-and-when required basis. The cooling water remains untreated generally. The Fast Breeder Test Reactor (FBTR) at Kalpakkam, TamiInadu, India is a 40 MWt sodium cooled, (uranium and plutonium) mixed carbide fuelled nuclear test reactor. In FBTR, four freon-based packaged AC units having 40 TR capacities with cooling water system have been installed in Annexe Building. Palar river water serves as the make-up to the system. The heat extracted from condensers is rejected in natural draft cooling tower. Initially, algae fouling and increased corrosion attacks were observed in the system. Sodium hypo chlorite dosing reduced the algae fouling considerably. Corrosion monitoring program was initiated with installation of corrosion monitoring set up. Inhibitors and dispersants like hydroxy ethylidene diphosphonic acid, sodium hexa meta phosphate, sodium dodecyl sulphate, ortho phosphoric acid and poly acrylic acid were used. It has been observed that minimum corrosion rate of 5 mpy could be obtained with 20 ppm of Hydroxy Ethylidene Diphosphonic Acid (HEDP) and 20 ppm of poly acrylic acid as against 9 mpy for the untreated water. This paper describes the problems associated with irregular operation of cooling water systems in corrosion control and experience gained in control of bio fouling and corrosion in cooling water system installed in packaged AC units having natural draft cooling tower. (author)

2008-01-01

80

Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.  

UK PubMed Central (United Kingdom)

The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

Liu Y; Zhang W; Sileika T; Warta R; Cianciotto NP; Packman A

2009-01-01

 
 
 
 
81

Water cooling considerations for the SSC  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this note is to specify parameters for hypothetical SSC water cooling systems, in order that the comparative advantages of these system can be studied. The various methods of heat rejection considered include: cooling towers, cooling ponds, ground water recharge system, water-to-air (dry) cooling towers, use of tunnel sump water, or some combination.

O' Meara, J.

1984-11-02

82

Piers cooling towers. From first idess to realizations  

International Nuclear Information System (INIS)

After a first part consecrated at the historical aspect of vertical piers cooling towers the second part indicates the experience pulled of the Chooz and Golfech cooling towers conception and realization.

1988-01-01

83

Piers cooling towers. From first idess to realizations  

Energy Technology Data Exchange (ETDEWEB)

After a first part consecrated at the historical aspect of vertical piers cooling towers the second part indicates the experience pulled of the Chooz and Golfech cooling towers conception and realization.

Bozetto, P.; Jalil, W.; Diver, M.; Tzincoca, A.

1988-09-01

84

Cooling tower windage: a new aspect to environmental assessment  

Energy Technology Data Exchange (ETDEWEB)

Results of the several investigations provided quantitative estimates of windage from Oak Ridge Gaseous Diffusion Plant cooling towers. Windage water deposited on the ground has the potential to reach nearby streams through runoff. Windage deposited on moisture depleted soils would not be significant. During winter months at Oak Ridge soils generally have a high moisture content such that windage deposition could be quickly transported as runoff. It is during this time that cooling towers are sometimes operated without fan-induced draft. Since windage water contains the same hexavalent chromium concentration (9 ppM) as the recirculating cooling water system, the runoff stream from the K-892J tower constitues a NPDES violation as an unpermitted discharge. As a long-term abatement strategy, concrete aprons were constructed along each side of new cooling towers at the Paducah, Kentucky Gaseous Diffusion Plant. The maximum distance of windage impact is wind dependent. If apron construction is envisioned as an abatement strategy at Oak Ridge, the maximum distance of impact can be inferred graphically from the several points where windage (fans off) and drift (fans on) loss curves intersect under the different meteorological conditions. Once the hexavalent chromium laden runoff stream reaches Poplar Creek, it is diluted well below the standards for drinking water and poses little potential for biological effects to aquatic systems.

Taylor, F.G.; Park, S.H.

1980-01-01

85

Cooling tower windage: a new aspect to environmental assessment  

International Nuclear Information System (INIS)

Results of the several investigations provided quantitative estimates of windage from Oak Ridge Gaseous Diffusion Plant cooling towers. Windage water deposited on the ground has the potential to reach nearby streams through runoff. Windage deposited on moisture depleted soils would not be significant. During winter months at Oak Ridge soils generally have a high moisture content such that windage deposition could be quickly transported as runoff. It is during this time that cooling towers are sometimes operated without fan-induced draft. Since windage water contains the same hexavalent chromium concentration (9 ppM) as the recirculating cooling water system, the runoff stream from the K-892J tower constitues a NPDES violation as an unpermitted discharge. As a long-term abatement strategy, concrete aprons were constructed along each side of new cooling towers at the Paducah, Kentucky Gaseous Diffusion Plant. The maximum distance of windage impact is wind dependent. If apron construction is envisioned as an abatement strategy at Oak Ridge, the maximum distance of impact can be inferred graphically from the several points where windage (fans off) and drift (fans on) loss curves intersect under the different meteorological conditions. Once the hexavalent chromium laden runoff stream reaches Poplar Creek, it is diluted well below the standards for drinking water and poses little potential for biological effects to aquatic systems

1980-04-23

86

Gasifier wastewater treatment: Phase I cooling tower assessment  

Energy Technology Data Exchange (ETDEWEB)

The principle goal of the gasification research at UNDERC is to develop environmental data on the treatability of wastewaters from the fixed-bed gasification of lignite. Research activities are focused around the cooling tower, where the reuse of treated gasification wastewaters has not been demonstrated in this country. The objective of Phase I cooling tower testing was to evaluate the effectiveness of using minimally treated wastewater (solvent extracted and steam stripped - referred to as stripped gas liquor) as makeup to a cooling tower. Ammonia, alkalinity, phenol, and other non-hydantoin organics were removed from the cooling water by stripping and/or biological degradation. Foaming of the circulating water will be a problem using SGL as makeup and foaming control will be required. The SGL feed cooling system supported a high level of biological activity (1 to 10 million/ml). Pseudomonas aeruginosa was identified as the predominant specie in the system. Severe fouling can be expected for all carbon steel surfaces. Fouling of stainless steel was not a major problem. General corrosion rates of 10 to 24 mils/yr were measured for carbon steel in various parts of the system. Carbon steel heat exchanger tube analysis indicated pitting corrosion penetration rates of 20 to 125 mils/yr under deposits. Computer analysis also indicated a strong potential for scaling from calcium carbonate precipitation. Results from this study indicate that the use of stripped gas liquor similar to that produced by the UNDERC pilot gasifier as cooling tower makeup is limited by a number of potentially serious operating problems. This water could be used for cooling tower makeup only after additional treatment or possibly with the use of biocides, corrosion inhibitors, and other control methods. 12 references, 6 figures, 7 tables. (DMC)

Mann, M.D.; Willson, W.G.; Hendrikson, J.G.; Winton, S.L.

1984-01-01

87

Inversions - incidence and effects on natural-draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The effects of side winds on natural-draught cooling towers have long been known and investigated. Another phenomenon affecting the characteristics of a natural-draught cooling tower is that of inversion, which has only discevered in recent years. The effects of inversion on big natural-draught cooling towers are discussed.

Tesche, W.

1981-07-01

88

Additional data on the effect of wind on the cooling performance of natural draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The cooling bahaviour of a natural draught cooling tower varies according to the effect of the wind, since the wind flow around the cooling tower causes a change in pressure distribution on the cooling tower shell compared with ratios when there is no wind, and consequently the air inflow and outflow conditions and the flow inside the cooling tower vary. An accurate understanding of the effect of wind on the cooling performance is therefore necessary for the design of a cooling tower. This paper describes a simple computerized model, by means of which the cooling air flow of a natural draught cooling tower subjected to wind effects can be predicted.

Dibelius, G.; Ederhof, A.

1981-06-01

89

Noise from cooling towers of power parks  

International Nuclear Information System (INIS)

[en] A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A-weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed

1975-01-01

90

Repair and completion of damaged cooling tower  

International Nuclear Information System (INIS)

This paper reports on a large hyperbolic cooling tower, under construction and nearly completed, struck by a falling tower crane during a tornado. Damage occurred at the upper edge where a V-shaped notch was gouged. Also, considerable cracking beneath the notch was observed. The extent of the damage was documented by precision survey techniques and visual inspection. A comprehensive analytical study was performed to insure that the completed tower would meet the design criteria. The repair plan involved repairing the cracks, sawing back the notch in a step fashion, refurbishing the scaffolding, rebuilding the gouged region, and then carrying the construction to completion. Also, two circumferential stiffening rings were added to the shell

1989-01-01

91

Repair and completion of damaged cooling tower  

Energy Technology Data Exchange (ETDEWEB)

This paper reports on a large hyperbolic cooling tower, under construction and nearly completed, struck by a falling tower crane during a tornado. Damage occurred at the upper edge where a V-shaped notch was gouged. Also, considerable cracking beneath the notch was observed. The extent of the damage was documented by precision survey techniques and visual inspection. A comprehensive analytical study was performed to insure that the completed tower would meet the design criteria. The repair plan involved repairing the cracks, sawing back the notch in a step fashion, refurbishing the scaffolding, rebuilding the gouged region, and then carrying the construction to completion. Also, two circumferential stiffening rings were added to the shell.

Gould, P.L. (Washington Univ., St. Louis, MO (United States). Dept. of Civil Engineering); Guedelhoefer, O.C. (Raths, Raths and Johnson, Inc., Willowbrook, IL (US))

1989-03-01

92

Effectiveness of bromicide against Legionella pneumophila in a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are considered to be man-made amplifiers of Legionella. Thus the proper maintenance and choice of biocides is important. The only biocide that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies were conducted on an industrial cooling tower shown to contain Legionella, using 1-bromo-3-chloro-5,5-dimethylhydantoin (Bromicide, Great Lakes Chemical Corp.). At the manufacturer's recommended concentrations neither the density nor the activity of Legionella was affected. At concentrations greater than 2.0 ppM free residual, the Bromicide was not effective in reducing Legionella to source water concentrations, nor was it effective in reducing the INT activity of the bacterium in situ. The data indicate that at concentrations up to 2.0 ppM, Bromicide is not effective in these tower studies. 23 references, 3 tables.

Fliermans, C.B.; Harvey, R.S.

1983-01-01

93

Cooling towers used for free cooling  

Energy Technology Data Exchange (ETDEWEB)

Energy costs and operating efficiency have gained considerable importance in the minds of many building owners and plant operators in recent years. Current prospects for future energy prices suggest that these issues will become even more urgent as environmental concerns and the high cost of money exert an ever greater impact on building design and operation. This article describes several free cooling design schemes. It also includes a review of the basic air-conditioning scheme as it applies to free cooling and a discussion of the trade-offs involved in equipment selection.

Murphy, D.

1991-06-01

94

Aspects of cooling tower biocides and protozoa  

Energy Technology Data Exchange (ETDEWEB)

Previous work has shown that certain cooling tower amoebae and ciliated protozoa are resistant to several cooling tower biocides, even at the manufacturer`s recommended dosages. For the present study, an Acunthumoeba species was isolated from a cooling tower in Australia. Suspensions of the trophozoites (feeding stages) were exposed to isothiazolones. Cysts were tested separately. The minimum lethal concentration (MLC) for trophozoites was between 31-62 ppm of the biocide product, which is slightly less than the MLC for an amoebae species from the United States; and cyst forms were twofold more resistant than those of the US species, with a MLC of 62,500 ppm. A ciliate and an amoeba species were also exposed to bromochlorodimethylhydantoin. The MLC for the ciliate species was 1 ppm of the biocide product, and the MLC was 30--40 ppm for the amoeba trophozoites. Since amoebae can expel vesicles containing live Legionella, experiments were conducted to determine whether exposure of Acunthamoebu polyphugu to biocides influenced release of such potentially infectious particles. Vesicle release was not inhibited by any of the three biocides: quaternary ammonium compounds (QACs), isothiazolones, and a thiocarbamate compound. These results suggest that amoebae from various sources are resistant to recommended levels of biocides, and the amoebae may continue to release potentially infectious vesicles in the presence of biocides.

Berk, S.G.; Ashburn, R.J.; Ting, R.S. [Tennessee Technological Univ., Cookeville, TN (United States). Center for the Management, Utilization and Protection of Water Resources

1998-12-31

95

Interception and retention of simulated cooling tower drift by vegetation  

International Nuclear Information System (INIS)

[en] A key issue concerning environmental impacts from cooling tower operation is the interception of drift by vegetation and the efficiency of plants in retaining the residue scavenged from the atmosphere. Chromated drift water, typical of the cooling towers of the Department of Energy's uranium enrichment facilities at Oak Ridge, Tennessee, was prepared using radio-labelled chromium. A portable aerosol generator was used to produce a spectrum of droplets with diameters (100 to 1300 ?) characteristic of cooling towers using state-of-the-art drift eliminators. Efficiency of interception by foliage varied according to leaf morphology with yellow poplar seedlings intercepting 72% of the deposition mass in contrast to 45% by loblolly pine and 24% by fescue grass. Retention patterns of intercepted deposition consisted of a short-time component (0 to 3 days) and a long-time component (3 to 63 days). Retention times, estimated from the regression equation of the long component, indicated that drift contamination from any deposition event may persist from between 8 and 12 weeks. In field situations adjacent to cooling towers, the average annual concentration of drift on vegetation at any distance remains relatively constant, with losses from weathering being compensated by chronic deposition

1978-05-04

96

Rainfall enhancement due to scavenging of cooling tower condensate  

International Nuclear Information System (INIS)

[en] The recent increase in the number of electrical generating plants that use cooling towers and projections for further expansion have prompted considerable concern about the environmental impact of large releases of energy and water effluent. One aspect of a comprehensive research program, Meteorological Effects of Thermal Energy Releases (METER), is an examination of the physical effects of the vast amounts of water vapor and condensate (tens of thousands of kilograms per second) regularly released by modern cooling towers. Such large releases can significantly affect water vapor and cloud-related natural processes, at least in the immediate vicinity. The question of precipitation scavenging of condensate droplets by natural precipitation and the resultant enhancement of precipitation under the plume is considered theoretically

1978-01-01

97

Site selection of meteorological tower and environmental impact assessment of the cooling tower  

International Nuclear Information System (INIS)

Meteorological characteristics related to the site complexity should be considered to assess the impact on the surrounding environment due to the operation of cooling towers of the KMRR. Meteorological towers should be installed in positions representing the site complexity well. The purpose of this project is to assess the environmental impact due to vapor and drift released from cooling towers as well as to select optimal locations of meteorological towers

1993-01-01

98

Performance prediction of a cooling tower using artificial neural network  

International Nuclear Information System (INIS)

[en] This paper describes an application of artificial neural networks (ANNs) to predict the performance of a cooling tower under a broad range of operating conditions. In order to gather data for training and testing the proposed ANN model, an experimental counter flow cooling tower was operated at steady state conditions while varying the dry bulb temperature and relative humidity of the air entering the tower and the temperature of the incoming hot water along with the flow rates of the air and water streams. Utilizing some of the experimental data for training, an ANN model based on a standard back propagation algorithm was developed. The model was used for predicting various performance parameters of the system, namely the heat rejection rate at the tower, the rate of water evaporated into the air stream, the temperature of the outgoing water stream and the dry bulb temperature and relative humidity of the outgoing air stream. The performances of the ANN predictions were tested using experimental data not employed in the training process. The predictions usually agreed well with the experimental values with correlation coefficients in the range of 0.975-0.994, mean relative errors in the range of 0.89-4.64% and very low root mean square errors. Furthermore, the ANN yielded agreeable results when it was used for predicting the system performance outside the range of the experiments. The results show that the ANN approach can be applied successfully and can provide high accuracy and reliability for predicting the performance of cooling towers

2007-01-01

99

Performance prediction of a cooling tower using artificial neural network  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an application of artificial neural networks (ANNs) to predict the performance of a cooling tower under a broad range of operating conditions. In order to gather data for training and testing the proposed ANN model, an experimental counter flow cooling tower was operated at steady state conditions while varying the dry bulb temperature and relative humidity of the air entering the tower and the temperature of the incoming hot water along with the flow rates of the air and water streams. Utilizing some of the experimental data for training, an ANN model based on a standard back propagation algorithm was developed. The model was used for predicting various performance parameters of the system, namely the heat rejection rate at the tower, the rate of water evaporated into the air stream, the temperature of the outgoing water stream and the dry bulb temperature and relative humidity of the outgoing air stream. The performances of the ANN predictions were tested using experimental data not employed in the training process. The predictions usually agreed well with the experimental values with correlation coefficients in the range of 0.975-0.994, mean relative errors in the range of 0.89-4.64% and very low root mean square errors. Furthermore, the ANN yielded agreeable results when it was used for predicting the system performance outside the range of the experiments. The results show that the ANN approach can be applied successfully and can provide high accuracy and reliability for predicting the performance of cooling towers. (author)

Hosoz, M. [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey); Ertunc, H.M. [Department of Mechatronics Engineering, Kocaeli University, 41040 Kocaeli (Turkey); Bulgurcu, H. [Department of Air Conditioning and Refrigeration Technology, Balikesir University, 10023 Balikesir (Turkey)

2007-04-15

100

Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method  

International Nuclear Information System (INIS)

[en] Highlights: ? Simulation of cooling tower performance under different operating conditions. ? Cooling tower performance is simulated using ASPEN PLUS. ? Levenberg–Marquardt method used to adjust model parameters. ? Air and water outlet temperatures are in good accordance with experimental data. - Abstract: Simulation of cooling tower performance considering operating conditions away from design is typically based on the geometrical parameters provided by the cooling tower vendor, which are often unavailable or outdated. In this paper a different approach for cooling tower modeling based on equilibrium stages and Murphree efficiencies to describe heat and mass transfer is presented. This approach is validated with published data and with data collected from an industrial application. Cooling tower performance is simulated using ASPEN PLUS. Murphree stage efficiency values for the process simulator model were optimized by minimizing the squared difference between the experimental and calculated data using the Levenberg–Marquardt method. The minimization algorithm was implemented in Microsoft Excel with Visual Basic for Applications, integrated with the process simulator (ASPEN PLUS) using Aspen Simulation Workbook. The simulated cooling tower air and water outlet temperatures are in good accordance with experimental data when applying only the outlet water temperature to calibrate the model. The methodology is accurate for simulating cooling towers at different operational conditions.

2012-01-01

 
 
 
 
101

Analysis of the evaporative towers cooling system of a coal-fired power plant  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

Lakovi? Mirjana S.; Lakovi? Slobodan V.; Banjac Miloš J.

2012-01-01

102

Mathematical modeling of cooling-tower plumes  

Energy Technology Data Exchange (ETDEWEB)

The vast majority of mathematical models used to predict plume rise from natural-draft (NDCT) and mechanical-draft (MDCT) cooling towers employ the integral approach. The following significant areas of controversy exist in the theoretical development of such models: assumptions needed to assure the proper balance between buoyancy and momentum transfer mechanisms; treatment of tower downwash; treatment of thermodynamics; treatment of atmospheric diffusion; and proper method for merging of plumes. The most successful models employ assumptions which appear physically reasonable with calibration of unknown coefficients with field and/or laboratory data. Such models are capable of predicting visible plume rise within a factor of 2 and visible plume length within a factor of 2.5 for 50 to 75% of most new field cases. Such accuracy is sufficient for most design and environmental impact evaluations. Only the ANL and KUMULUS Models of this better-performing group are sufficiently general, however, to handle any configuration of NDCTs and MDCTs.

Carhart, R.; Policastro, A.

1982-01-01

103

CFD MODELING ANALYSIS OF MECHANICAL DRAFT COOLING TOWER  

Energy Technology Data Exchange (ETDEWEB)

Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be presented here.

Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

2008-03-03

104

Susceptibility of Legionella pneumophila to three cooling tower microbicides  

Energy Technology Data Exchange (ETDEWEB)

Investigation of epidemic outbreaks of Legionnaires disease by Center for Disease Control personnel has resulted in the isolation of Legionella pneumophila from water in the air-conditioning cooling towers or evaporative condensers at the site of the outbreak. It is suspected that improperly maintained open, recirculating water systems may play a role in the growth and dissemination of this pathogen. The objective of this study was to determine the antimicrobial activity of three chemically different, commercially available, cooling tower microbicides against L. pneumophila. Using two in vitro test systems, a combination of N-alkyl dimethyl benzyl ammonium chloride and bis (tri-n-butyltin) oxide was found to kill L. pneumophila at a concentration 25 times less than the minimum recommended use concentration, whereas N-alkyl 1,3-propanediamine and methylene bis(thiocyanate) were active at concentrations equal to or greater than the concentrations recommended for use by the manufacturer.

Grace, R.D. (Chemed Corp., St. Louis, MO); Dewar, N.E.; Barnes, W.G.; Hodges, G.R.

1981-01-01

105

Air throughput of natural-draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The number of natural-draught cooling towers constructed in the GDR keeps increasing although air throughput is difficult to calculate for this type of cooling tower. The state of the art is reviewed, and a new method of approximation for simple and accurate calculation of air throughput is presented as well as a program to calculate the operating characteristics of natural-draught cooling towers.

Mehlig, J.G.

1982-05-01

106

Cooling towers and prevention of legionella; Koeltorens en legionellapreventie  

Energy Technology Data Exchange (ETDEWEB)

Two years ago an epidemic of legionellosis occurred on a flower show in the north of The Netherlands. It resulted in the biggest outbreak of legionnaires' disease in the world with more than 200 cases of legionellosis and an estimate of 28 deceased persons. The incident made prevention of legionellosis a major health topic in The Netherlands. However, little attention is given to the prevention of legionella bacteria in wet cooling towers. In the Netherlands, sporadic reports can be found about the presence of legionella bacteria in cooling towers. Cooling towers have n ever been associated with cases of legionnaires' disease, as whirlpools, faucets and showers have. Experiences elsewhere, for example in Australia and Great-Britain, show that the use of cooling towers imposes a health risk for persons in the surrounding area, i.e. inside the building or in the open air. The experiences and guidelines from other countries can be used to define rules for legionella prevention in Dutch cooling towers because the circumstances in cooling towers are universal: temperature, aeration and nutrients make cooling towers an ideal incubator for micro-organisms. Drift spreads little droplets containing legionella bacteria. Criteria for design, proper maintenance and monitoring can reduce the health risk. In the article, suggestions are given for preventive measures. As the exploitation costs of cooling towers will rise, and because health risks will never be reduced to zero, it is expected that wet cooling towers will gradually disappear. 8 refs.

Schalekamp, J.D. [Afdeling Medische Milieukunde, Gemeentelijke Gezondheidsdienst voor Rotterdam en omstreken, Rotterdam (Netherlands)

2001-03-01

107

Experimental study on the thermal performance of a mechanical cooling tower with different drift eliminators  

International Nuclear Information System (INIS)

[en] Cooling towers are equipment devices commonly used to dissipate heat from power generation units, water-cooled refrigeration, air conditioning and industrial processes. Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health hazards. It is common practice to fit drift eliminators to cooling towers in order to minimize water loss from the system. It is foreseeable that the characteristics of the installed drift eliminators, like their pressure drop, affect the thermal performance of the cooling tower. However, no references regarding this fact have been found in the reviewed bibliography. This paper studies the thermal performance of a forced draft counter-flow wet cooling tower fitted with different drift eliminators for a wide range of air and water mass flow rates. The data registered in the experimental set-up were employed to obtain correlations of the tower characteristic, which defines the cooling tower's thermal performance. The outlet water temperature predicted by these correlations was compared with the experimentally registered values obtaining a maximum difference of ±3%

2009-01-01

108

Method and system for simulating heat and mass transfer in cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The present invention is a system and method for simulating the performance of a cooling tower. More precisely, the simulator of the present invention predicts values related to the heat and mass transfer from a liquid (e.g., water) to a gas (e.g., air) when provided with input data related to a cooling tower design. In particular, the simulator accepts input data regarding: (a) cooling tower site environmental characteristics; (b) cooling tower operational characteristics; and (c) geometric characteristics of the packing used to increase the surface area within the cooling tower upon which the heat and mass transfer interactions occur. In providing such performance predictions, the simulator performs computations related to the physics of heat and mass transfer within the packing. Thus, instead of relying solely on trial and error wherein various packing geometries are tested during construction of the cooling tower, the packing geometries for a proposed cooling tower can be simulated for use in selecting a desired packing geometry for the cooling tower.

Bharathan, Desikan (Lakewood, CO); Hassani, A. Vahab (Golden, CO)

1997-01-01

109

Efficiency control in a commercial counter flow wet cooling tower  

International Nuclear Information System (INIS)

This paper presents open and closed-loop analyses of a counter flow wet cooling tower. The closed-loop system analysis was based on a comparative evaluation of three control strategies. The first and second comprised a split-range control of the cooling water temperature and an index of thermal performance (efficiency), respectively, and the third strategy comprised a combination of override and split-range control in order to control two performance indexes (efficiency and effectiveness). In this case, a SISO (Single-Input Single-Output) loop for each controlled variable is considered. In each case the water loss through evaporation and the energy consumption in the cooling tower (pump and fans) were estimated in order to analyze its eco-efficiency. All the simulation tests were carried out considering the same regulatory problem and the results show a notable improvement in the tower's performance when compared to open-loop operation, thus attesting the potential benefits of the use of an efficient control strategy for such equipment.

2009-01-01

110

The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers  

International Nuclear Information System (INIS)

Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.

2008-07-08

111

Determination of emission characteristics from the UNDERC cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The Great Plains Gasification Associates (GPGA) plant at Beulah, North Dakota, and many other synfuels plants in the future, will be producing thousands of gallons of wastewater per day. There is a need for development of environmental data concerning effluents from fixed-bed coal gasification. The University of North Dakota Energy Research Center (UNDERC) is addressing this need as one of the principle goals of its wastewater treatment program. UNDERC has various types of wastewater treatment and reuse unit operations, designed to yield scaleable data, which are currently being operated on wastewater from the UNDERC slagging fixed-bed gasifier. A part of this equipment is a forced-draft cooling tower which utilizes this wastewater as makeup. Phase I cooling tower testing at UNDERC was designed to use as feed minimally treated wastewater (solvent extracted for organics removal and steam stripping for ammonia and acid gas removal) to simulate the proposed GPGA water treatment plan. A crucial part of this study was the determination of the atmospheric effects resulting from the use of the stripped gas liquor (SGL) as feed to the cooling tower. Several types of sampling equipment including a multicyclone, cooled impingers, and an XAD resin trap, were used for the collection and retention of components present in the tower evaporate. A comparative study of several drift measurement techniques was also performed using chemical and material balances around the system. Results indicated that a significant portion of phenol and ammonia in the makeup water (91 and 81 percent, respectively) were stripped into the atmosphere. Twenty-one percent of the methanol was also stripped.

Mann, M.D.; Galegher, S.J.

1984-02-16

112

NDE-based structural life expectancy of timber cooling towers  

Energy Technology Data Exchange (ETDEWEB)

As the case with any structure, the components of the cooling tower deteriorate over time. Once the tower has been in service for a few years, the most frequently encountered engineering and management questions include: How safe is the tower today? How frequently should inspection be scheduled? What is the rate of structural degradation? What is the usable service life of the tower? Should the tower be repaired or replaced? How should the tower be maintained to derive the most cost effective performance? What level of inspection and maintenance schedule are needed? How much and when should money be budgeted to repair or replace the tower? This paper provides information on some of the tools and methodologies available today to answer the above questions. It focuses on the structural reliability and life expectancy of wood cooling towers. It includes fundamental considerations as well as examples of applications.

Bodig, J.; Pandey, A.K. [Engineering Data Management, Inc., Fort Collins, CO (United States)

1996-10-01

113

Investigation of emissions of harmful substances in the cooling tower of the final coke oven gas cooling cycle  

International Nuclear Information System (INIS)

[en] It is known that the cooling tower of the open coke oven gas cooling cycle is the main source of emissions to the atmosphere of hydrogen cyanide. Desorption of volatile harmful substances in cooling tower depends on a large number of processing parameters and the compositions of the circulating water. The authors conducted a study of desorption of volatile components and a model of adequate scale of the final gas cooling cycle on an experimental industrial unit with a gas output of about 500 m3/hr. The unit was built at the Cherepovets Integrated Iron and Steel Works. In includes a cooling tower made of tubes 100 mm in diameter with a total height of about 5,100 mm. The volume of the lower part is 2.12 m3. Preliminary experimental evaluation of operation of the cooling tower according to the material and heat balances showed that it models operation of an industrial cooling tower quite well. Emissions of harmful substances in the cooling tower were determined by analyzing the circulating water and air before and after the cooling tower. Averaged samples for specified times were collected and the process parameters were simultaneously recorded (flow rates and temperatures of water and air), as well as the relative humidity and air pressure. Analysis of possible errors and the actual agreement of the determinations of the content of substances in air and water showed that evaluation of desorption of volatile components according to water analyses is more reliable (this conclusion is especially valid for industrial cooling towers). Results are described

1990-01-01

114

Optimization of cooling tower performance analysis using Taguchi method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions...

Ramkumar Ramakrishnan; Ragupathy Arumugam

115

Effects of power plant cooling towers on the environment  

Energy Technology Data Exchange (ETDEWEB)

The effect of power-station cooling towers on the environment is described. Besides the primary effects of steam and heat emission, such as changes in temperature, moisture, and deposits, they also deal with the secondary effects (shade, deposits from the damage to the cooling tower.)

Busche, H.J.; Blum, A.; Frank, J.; Wiesner, S.

1982-03-01

116

Emission of air-borne pollutants from cooling towers  

International Nuclear Information System (INIS)

The operation of natural-draught wet cooling towers involves water released to the atmosphere as vapour and by windage loss. The emission of pollutants are no physical or ecological problem, all the more so as no highly active raw waters are used for operation. Meteorological effects may be neglected. The same applies to the emission of chemicals and microorganisms. The effects of large buildings on the landescape must be assessed from a political angle. The electrical power industries is still requested to efficiently recuperate waste heat even in unfavourable locations. (DG)

1983-05-06

117

Hydroaerothermal investigations conducted in the USSR to justify the construction of large cooling towers  

International Nuclear Information System (INIS)

The multi-purpose task of improving water cooling systems of thermal and nuclear power plants is aimed at the development of efficient designs of cooling towers and other types of industrial coolers which call for comprehensive scientific justification. Cooling towers of 60-70 thou m3/h capacity with a chimney height of 130 m and those of 80-100 thou m3/h capacity with a chimney height of 150 m were developed. For circulating water systems of large power plants the design of a counterflow chimney cooling tower of 180 thou m3/h capacity has been recently developed. At present the work is being conducted on developing a new three-cell cooling tower featuring high reliability, operational flexibility and cost-effectiveness of the design. This cooling tower, besides having higher operating reliability than the conventional one of circular shape, can ensure the commissioning, current repairs and overhauls of water cooling arrangements in a cell-wise sequence, i.e. without shutting down the power generating units. Laboratory and field investigations of the spray-type cooling towers having no packing (fill), studies on heat and mass exchanges processes, aerodynamics of droplet flows and new designs of sprayers made it possible to come to a conclusion that their cooling capacity can be substantially increased and brought up to the level of the cooling towers with film packings. The pilot cooling towers were designed according to the counterflow, crossflow and cross-counterflow schemes. The basic investigation method remains to be the experimental one. On the test rigs and aerodynamic models the heat and mass transfer and aerodynamic resistance coefficients are determined. These studies and subsequent calculations are based on the heat balance equation.

1989-01-01

118

Inspection of JMTR secondary cooling system. Secondary cooling system piping and cooling tower  

International Nuclear Information System (INIS)

JMTR secondary cooling system piping and a cooling tower were inspected from the view point of long term utilization before the renewal work for the secondary cooling system of the JMTR on FY 2008. As the result, it was confirmed that crack, swelling, and exfoliations in inner of piping lining, and decay and dryness of wood in the upper part of the cooling tower. From the result of this inspection some facilities and machinery were repaired or replaced from the view point of preventive maintenance. (author)

2010-01-01

119

Rainfall enhancement due to washout of cooling tower condensate  

International Nuclear Information System (INIS)

Theoretical calculations of the washout of cooling tower condensate droplets by frontal raindrops show that rainfall enhancement can be significant and is measurable under typical meteorological and cooling tower effluent source conditions. For the case of moderate rainfall rates and a wind speed of 5 m/sec, centerline rainfall enhancement was as much as 46%, cross-plume average enhancement as much as 7%, and distance to one-half depletion of the source 1 to 10 km

1978-01-01

120

Environmental Impacts from the Operation of Cooling Towers at SRP  

Energy Technology Data Exchange (ETDEWEB)

An assessment has been made of the environmental effects that would occur from the operation of cooling towers at the SRP reactors. A more realistic numerical model of the cooling tower plume has been used to reassess the environmental impacts. The following effects were considered: (1) the occurrence of fog and ice and their impact on nearby structures, (2) drift and salt deposition from the plume, (3) the length and height of the visible plume, and (4) the possible dose from tritium.

Smith, F.G. III

2001-06-26

 
 
 
 
121

Structural engineering developments in power plant cooling tower construction. 100 years of natural draught cooling towers - from tower cooler to cooling tower. Bautechnische Entwicklungen im Kraftwerkskuehlturmbau. 100 Jahre Naturzugkuehltuerme - vom Kaminkuehler zum Kuehlkamin  

Energy Technology Data Exchange (ETDEWEB)

Almost exactly 100 years ago, tower-type structures were first used for the production of artificial ventilation for cooling purposes. The shell of these so-called tower coolers, today known as 'natural draught cooling towers', was, from the outset, the subject of multiple structural engineering develepments in respect of design, material, construction and statistical calculation. These developments have been stimulated especially by the spasmodic increase in dimensions in the application of power plant cooling towers and, more recently, in connection with ecological requirements. (orig.).

Damjakob, H.; Depe, T.; Vrangos, V. (Balcke-Duerr AG, Ratingen (Germany))

1992-06-01

122

Experimental study on the performance of mechanical cooling tower with two types of film packing  

Energy Technology Data Exchange (ETDEWEB)

In this work, an experimental and a comparative study on terms of tower characteristics (KaV/L), water to air flow ratio (L/G) and efficiency for two film type packings are presented for a wide range of (L/G) ratio from 0.2 to 4. The packings used in this work are vertical corrugated packing (VCP) and horizontal corrugated packing (HCP). The obtained results showed that the performance of the cooling tower is affected by the type and arrangement of the packings. Also, the tower performance showed a decrease with an increase in the (L/G) ratio as is also observed in other types of cooling towers. The results showed the tower with vertical corrugated packing (VCP) has higher efficiency than the one with horizontal corrugated packing (HCP)

Gharagheizi, Farhad [Department of Chemical Engineering, Faculty of Engineering, University of Tehran, PO Box 11365-4563, Tehran (Iran, Islamic Republic of)]. E-mail: fghara@engmail.ut.ac.ir; Hayati, Reza [Department of Chemical Engineering, Faculty of Engineering, University of Tehran, PO Box 11365-4563, Tehran (Iran, Islamic Republic of); Fatemi, Shohreh [Department of Chemical Engineering, Faculty of Engineering, University of Tehran, PO Box 11365-4563, Tehran (Iran, Islamic Republic of)

2007-01-15

123

Cooling tower shell and mechanical or draft cooling tower with a such shell  

International Nuclear Information System (INIS)

[en] The shell is for thermal power plants cooling towers having heat exchange surfaces inside the tower. The vertical is such that the hydraulic diameter D in each horizontal section, at a level z above a reference section of which hydraulic diameter is Do is between once and 1.15 time the value given by the formula: Do(1+(2??gz/?Vo2))O,25 + 2?z in which Vo is the vertical flow rate through the reference section; ? is the hot air density; ?? is the density difference of the hot air between the outside and the inside of the shell; ? is an adjustment parameter without dimension of which value is between 0.09 and 0.13. The present invention ensures the cooling tower to operate nearly at the optimum and the construction cost of the shell is reduced[fr] La coque est destinee a un refrigerant atmospherique pour centrale thermique ayant des surface d'echange situees a l'interieur du refrigerant. Le profil vertical de la coque est tel que le diametre hydraulique D dans chaque section horizontale, a une altitude z au-dessus d'une section de reference ou le diametre hydraulique est Do et compris entre une fois et 1,15 fois la valeur donnee par la formule: Do(1+(2??gz/?Vo2))0,25 + 2?z dans laquelle: Vo est la vitesse debitante verticale dans la section de reference; ? est la masse volumique de l'air chaud; ?? est l'ecart de masse volumique de l'air chaud entre l'exterieur et l'interieur de la coque; ? est un parametre de calage sans dimension compris entre 0,09 et 0,13. La presente invention assure un fonctionnement proche de l'optimum et au surplus permet de reduire le court de realisation de la coque

1984-06-21

124

The impacts of retrofitting cooling towers at a large power station  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the results of a detailed study of the impacts that a proposed mandated closed-cycle, cooling tower retrofit would have on a two unit 2200 MW{sub e} nuclear operating facility. The paper discusses the complexity involved with such an undertaking, the adverse impact on plant performance, increased operating and maintenance cost, schedule considerations, options that would minimize impacts, and the overall costs involved with such an undertaking. Retrofitting a once-through cooling water system for closed-cycle would require significant redesigns, including modifying the cooling water flow; the construction of cooling towers; review and refurbishment of the condensers, circulating water pumps, piping pressure rating, chemical feed, blowdown, makeup systems, pumps, and pump houses; and providing sufficient circulating water piping to form a closed loop system. There are also several site conditions that also would materially affect the retrofit, e.g. availability of adequate space to accommodate the towers and support systems, site soil conditions, groundwater considerations, etc. The impacts associated with these are presented. This paper indicates that retrofitting a large two unit operating nuclear facility for closed-cycle cooling would not simply involve adding cooling towers to the existing cooling water system. Rather, the effort would require substantial new construction, demolition, and reconstruction activities that could result in replacing, reinforcing, or abandoning a significant portion of the entire existing circulating water system. Such a retrofit project would be wide-scale and complicated and would be unprecedented at a facility of the size studied.

Burns, J.M.; Nicholson, J.M. [Stone & Webster Engineering Corp., Boston, MA (United States); Annett, J.H.; Alexander, D.N. [Public Service Electric and Gas Company, Hancocks Bridge, NJ (United States)

1995-02-01

125

A simulation software for cooling towers optimal operation  

Energy Technology Data Exchange (ETDEWEB)

Deregulation of power markets in Europe will facilitate competing alternatives in power supplies, more competitive energy prices and will improve customer service. The Romanian power sector is also characterized by profound transformation from old, polluting system to one reaching for efficiencies of market-driven economy. In order to reduce the production costs of combined electricity and heat generation power plants, the paper presents the software called CTO for optimization of the cross-current cooling tower`s operation. The optimum operation of the cooling tower will be that which performs the removal of the waste heat-of imposed thermal level- at a minimum specific cost. For different alternatives of the known input values and for all possible operation diagrams the cooling tower parameters are calculated through the developed software. As a result its optimum operation conditions are indicated.

Damian, M.; Motoiu, I.; Caracasian, L. [Inst. of Power Studies and Design, Bucharest (Romania)

1998-12-31

126

Hudson River cooling tower proceeding: Interface between science and law  

International Nuclear Information System (INIS)

[en] As the Hudson River power plant case proceeded, the regulatory ground shifted under the utility companies. At first, the US Environmental Protection Agency (EPA) contended that the utilities should build expensive closed-cycle cooling towers at three plants to minimize the plants' discharge of heated effluents to the river. When the formal hearing began, however, EPA claimed that cooling towers were needed to minimize the number of organisms impinged at and entrained through the plants. The Hudson River proceeding became a policy dispute over what the appropriate standard of environmental conduct should be, instead of a determination of whether a standard had been met or not. Such policy issues, which arise when legal precedent has yet to be developed for new laws like the Clean Water Act, are better addressed by a rule-making proceeding than by the adjudicatory hearing format used in the Hudson case. A rule-making proceeding would have markedly shortened the Hudson deliberations, probably without substantive change in the final settlement, and is recommended for future cases in which ambiguity in legislation or the lack of precedent has left policy matters unresolved. 2 refs

1988-01-01

127

Evaluation of the RSG-GAS cooling tower performance  

International Nuclear Information System (INIS)

[en] Utilization of RSG-GAS reactor should be operated as efficiently as possible, so that reactor operation planning using one line primary coolant can be anticipated. To analyze the performance of the RSG-GAS cooling tower with one line primary coolant doing by using same data from 10 MW thermal reactor operation. The result were then compare to those achieved using CATHENA code. The results indicated that, for design condition the ratio of water flowrate to air is (L/G) 1.52 and number transfer unit (NTU) is 0.348. For operation condition, the average of L/G and NTU are respectively 1.37 and 0,348. Moreover the results achieved by the code showed that L/G and NTU are respectively 1.35 and 0,302. The performance of cooling tower achieved operation condition and the code results are respectively 91% and 72%. This means that the calculated results are lower than measurement results

2003-01-01

128

Experimental study and predictions of an induced draft ceramic tile packing cooling tower  

International Nuclear Information System (INIS)

[en] Deterioration of the filling material in traditional cooling towers is of serious concern. In this study, long life burned clay is used as the filling material. It guards against common cooling tower problems resulting from chemical water treatment and deterioration. The size of the ceramic packing material and outlet conditions predictions by theoretical modeling require heat and mass transfer correlations. An experimental study to evaluate the heat and mass transfer coefficients is conducted. The previous correlations found in the literature could not predict the mass transfer coefficient for the tested tower. A mass transfer coefficient correlation is developed, and new variables are defined. This correlation can predict the mass transfer coefficient within an error of ±10%. The developed correlation is used along with theoretical modeling to predict the cooling tower outlet conditions within an error of ±5%

2006-01-01

129

Assessment of the effect of water source of health risk in a pilot project to promote the reuse of reclaimed water in cooling towers; Valoracion del efecto del origen del agua en el riesgo sanitario en una experiencia piloto para promover la reutilizacion de agua regenerada en torres de refrigeracion  

Energy Technology Data Exchange (ETDEWEB)

Wastewater regeneration and reuse of regenerated water permits to increase the amount of water and guarantees the availability required, in terms of both quantity and quality. In this context, a research project on regenerated water reuse for cooling towers has been carried out by the Universitat Politecnica de Catalunya (UPC), the Water Catalan Agency (ACA) and the Council of Chambers of Commerce. The research consisted of two steps. A first objective was to verify the effect of water source in the colonization of cooling towers by Legionella. In order to achieve those objectives, effluents from different wastewater treatment plant stages were used. The second objective was to evaluate in situ the disinfection process in order to decrease the sanitary risk from water reuse for cooling towers. For the entire duration of the project, both conventional culture methods and new molecular techniques with real times PCR were performed to detect Legionella from water samples. (Author) 17 refs.

Fittipaldi, M.; Codony, F.; Puigdengoles, J. M.; Molist; Morato, J.

2009-07-01

130

Sampling and detection of Legionella pneumophila aerosols generated from an industrial cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Cooling tower water has frequently been cited as a source of infection in outbreaks of Legionnaires' disease. However, there have been few reports on the presence of legionellae in aerosols from cooling towers. This paper describes our use of an impinger or a six-stage microbial impactor for detecting legionellae in air around a cooling tower contaminated with L. pneumophila (1.2{+-}0.3x10{sup 5} CFU/100ml). Phosphate-buffered saline, Page's saline, 2% yeast extract solution and buffered yeast extract (BYE) broth were tested to evaluate their collection efficiency. These solutions were compared in laboratory experiments using an aerosol of L. pneumophila serogroup (SG) 1. Because BYE broth was the most efficient and storable collecting fluid among them, it was used for outdoor air sampling. In the outdoor air sampling, aerosolized L. pneumophila SG 6 was detected in the air around the cooling tower by the impinger (0.09 CFU/1. air). No legionellae were detected by the impactor with Legionella-selective agar plates (WYO{alpha}) because the plates were overgrown with fungi. Repetitive element PCR (rep-PCR) and arbitrarily primed PCR (AP-PCR) were employed to assess the epidemiological relationship among Legionella isolates from the air sample and the cooling tower water samples. L. pneumophila SG 6 isolated from the aerosols produced rep-PCR and AP-PCR fingerprints identical to those of L. pneumophila SG 6 strains from the cooling tower water, suggesting that the bacterium was aerosolized from the cooling tower. (author)

Ishimatsu, Sumiyo; Hori, Hajime [University of Occupational and Environmental Health, Kitakyushu (Japan). Dept. of Environmental Management; Miyamoto, Hiroshi [University of Occupational and Environmental Health, Kitakyushu (Japan). Dept. of Microbiology; Tanaka, Isamu [University of Occupational and Environmental Health, Kitakyushu (Japan). Dept. of Environmental Health Engineering; Yoshida, Shinichi [Kyusha Univ., Fukuoka (Japan). Dept. of Bacteriology

2001-07-01

131

Flue gas injection control of silica in cooling towers.  

Energy Technology Data Exchange (ETDEWEB)

Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

2011-06-01

132

Cooling tower drift studies at the Paducah, Kentucky Gaseous Diffusion Plant  

International Nuclear Information System (INIS)

The transfer and fate of chromium from cooling tower drift to terrestrial ecosystems were quantified with concentrations in plant materials (fescue grass) decreasing with increasing distance from the cooling tower. Results indicate that elemental content in drift water (mineral residue) may not be equivalent to the content in the recirculating cooling water of the tower. This hypothesis is contrary to basic assumptions in calculating drift emissions. Results suggest that differences in retention in litter and foliage are related to chemical properties of the drift rather than physical lodging of the particle residue. To determine the potential for movement of drift-derived chromium to surface streams, soil-water samplers (wells) were placed along a distance gradient to Little Bayou Creek. Preliminary model estimates of drift deposition are compared to deposition measurements

1978-01-01

133

Legionella safety in cooling towers; Legionellaveiligheid in koeltorens  

Energy Technology Data Exchange (ETDEWEB)

In 9 articles attention is paid to several aspects with regard to Legionella in cooling towers: representative sampling, the use of copper and silver ionization or hydrogen peroxide to prevent Legionella growth and biofilms, the use of a zero-tolerance model to control a cooling tower installation, detection of DNA of Legionella Pneumophila, legionella safety in air conditioners, the model Legionella risk analysis and control of cooling tower installations, legislation and regulations for the control of cooling tower installations with regard to the Dutch Occupational Health and Safety Act ('Arbo-wet'), and an article about a lawsuit for victims of a Legionella outbreak, caused by careless owners of a cooling tower in Amsterdam, Netherlands. [Dutch] In 9 artikelen wordt in deze aflevering aandacht besteed aan verschillende aspecten m.b.t. Legionella in koeltorens: representatieve monstername, de toepassing van koper en zilver-ionisatie of waterstofperoxide om de groei van Legionella en biofilms te voorkomen, het gebruik van een zero-tolerance model om een koeltoren installatie te controleren, detectie van DNA van Legionella Pneumophila, Legionella veiligheid in luchtbehandelingsinstallaties, het model Legionella risicoanalyse en beheersplan voor koeltoreninstallaties, de rol van de Arbo-wet, en een artikel over een rechtszaak voor slachtoffers van Legionella door onzorgvuldig beheer van een koeltoren in Amsterdam.

Kordes, B. [Kordes Advies, (Netherlands); De Bok, F. [KBBL Wijhe, (Netherlands); De Zeeuw, L. [Holland Environment Group, (Netherlands); Settels, P. [Safety, Health Services and Ergonomics, ING, (Netherlands); Oesterholt, F.; Wullings, B. [KWR Watercycle Research Institute, (Netherlands); Guiot, P. [Tevan, Gorinchem (Netherlands); Brands, R. [Cumulus Nederland, Cuijk (Netherlands); Nuijten, O. [Kennisinstituut ISSO, Rotterdam (Netherlands); Wijne, R. [Beer advocaten, Amsterdam (Netherlands)

2010-04-15

134

Cooling tower visible plume rise analyses by time integrated photographs  

Energy Technology Data Exchange (ETDEWEB)

Cooling tower plume rise measurements are required for evaluation and validation of cooling tower plume rise models. In August 1981, five cooling tower plume defining experiments were conducted at the Geysers Geothermal Area in California during both valley nocturnal drainage flow conditons, and diurnal limited vertical mixing conditions on a mountain ridge. Sequential 300-s time integrated photographs of the plumes were made for several hours during each experiment. Time lapse movies were also made during the daytime experiments. Meteorological conditions were measured during all experimental periods by tethersonde and rawinsonde. The time integrated photographs have been analyzed to provide values of plume rise heights vs time for each of the experiments. Predictions by one version of the Argonne National Laboratory plume rise model are within a factor of 2 of the plume rise calculated from the photographs.

Thorp, J.M.; Orgill, M.M.

1984-01-01

135

Cooling tower practice in Germany: state of the art  

Energy Technology Data Exchange (ETDEWEB)

Development in design and construction of natural draught cooling towers that has taken place in Germany is discussed. Research has been concentrated on theory and analysis of shells, on acting forces, especially on wind effects, on buckling behavior and constructional problems. An approximate earthquake analysis allows a quick estimation of seismic response. The earthquake analysis is carried out by the response-spectrum-method. All design methods develop construction methods minimizing the imperfections and their control and correction during the erection process. It is shown how by arranging stiffening rings the buckling resistance and the lowest natural frequency of this new generation of cooling towers can be improved. 13 refs.

Zerna, W.; Kraetzig, W.B.; Mungan, I.

1982-03-01

136

Calculation of cooling tower plumes for high pressure wintry situations  

International Nuclear Information System (INIS)

[en] The diffusion of the plumes of the projected nuclear power plants at Kaiseraugst and Schwoerstadt, during high pressure wintry conditions, has been examined using a mathematical model to simulate the plumes. For these calculations, microaerological measurements were made in the proximity of Kaiseraugst and Schwoerstadt. These give a typical image of the weather during high pressure wintry conditions, which is normally associated with an inversion, sometimes strong, at a low height. Dry cooling towers with natural draught, which offer an alternative solution to the wet cooling towers proposed for Kasieraugst, are examined equally. (Auth./G.T.H.)

1982-01-01

137

Environmental impact of cooling towers of large nuclear power plants  

International Nuclear Information System (INIS)

[en] The computer program for the calculation of the 3-dimensional rise of cooling tower plumes was examined on the basis of the measurements at Neurath. The program MEDINT developed by the department 'Datenverarbeitung und Instrumentierung' allows now the calculation of the distribution of different parameters in any cross-section of the cooling tower plume, which are needed for the tests. (orig.)[de] Das Computer-Programm zur Berechnung des 3-dimensionalen Aufstiegs von Kuehlturmfahnen wurde anhand der Messungen in Neurath weiter ueberprueft. Das von der Abteilung Datenverarbeitung und Instrumentierung neu entwickelte Interpolationsprogramm MEDINT erlaubt jetzt die Berechnung von Verteilungen verschiedener Parameter in beliebigen Schnitten durch die Kuehlturmfahne. (orig.)

1975-01-01

138

Design of cooling towers, wet air coolers and air wetting for cross flow systems  

Energy Technology Data Exchange (ETDEWEB)

The description of the heat and mass transfer of a cross-flow method for cooling towers, wet-air coolers and humidifiers is rather complicated as compared to the description of a countercurrent method. In a countercurrent apparatus the rising air gets in touch with water that becomes colder in the case of an air cooler and with water that becomes warmer in the case of an evaporative cooling tower for water cooling. In a cross-flow apparatus the air flowing through it meets water of different temperatures, the mass of air being nonuniformly cooled down or heated up. The air discharged by a cross-flow apparatus therefore is not homogeneous if considered psychrometically.

Dirkse, R.J.A.

1982-01-01

139

Alkaline approach to treating cooling towers for control of Legionella pneumophila  

Energy Technology Data Exchange (ETDEWEB)

Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggest that control of Legionella species in cooling towers can be accomplished by operating the towers under alkaline conditions. To test this possibility, we collected water samples over a period of months from a hospital cooling tower. The samples were analyzed for a variety of chemical parameters. Subsamples were pasteurized and inoculated with non-agar-passaged Legionella pneumophila which had been maintained in tap water. Correlation of subsequent Legionella growth with corresponding pH and alkalinity values revealed statistically significant inverse associations. These data support the hypothesis that operating cooling towers outside of the optimal conditions for Legionella growth (e.g., at elevated alkalinities and a pH greater than 9) may be a useful approach to controlling growth in this habitat.

States, S.J.; Conley, L.F.; Towner, S.G.; Wolford, R.S.; Stephenson, T.E.; McNamara, M.; Wadowsky, R.M.; Yee, R.B.

1987-08-01

140

Performance prediction of wet cooling tower using artificial neural network under cross-wind conditions  

International Nuclear Information System (INIS)

This paper describes an application of artificial neural networks (ANNs) to predict the thermal performance of a cooling tower under cross-wind conditions. A lab experiment on natural draft counter-flow wet cooling tower is conducted on one model tower in order to gather enough data for training and prediction. The output parameters with high correlation are measured when the cross-wind velocity, circulating water flow rate and inlet water temperature are changed, respectively. The three-layer back propagation (BP) network model which has one hidden layer is developed, and the node number in the input layer, hidden layer and output layer are 5, 6 and 3, respectively. The model adopts the improved BP algorithm, that is, the gradient descent method with momentum. This ANN model demonstrated a good statistical performance with the correlation coefficient in the range of 0.993-0.999, and the mean square error (MSE) values for the ANN training and predictions were very low relative to the experimental range. So this ANN model can be used to predict the thermal performance of cooling tower under cross-wind conditions, then providing the theoretical basis on the research of heat and mass transfer inside cooling tower under cross-wind conditions. (authors)

2009-01-01

 
 
 
 
141

Concentration, serotypic profiles, and infectivity of Legionnaires' Disease bacteria populations in cooling towers  

Energy Technology Data Exchange (ETDEWEB)

At the Philadelphia American Legion Convention in 1976 nearly two hundred people developed pulmonary infection. Of these, twenty-eight died. The causative bacterial agent was subsequently isolated and identified as a previously undiscovered human pathogen, that is, Legionnaires' Disease Bacterium (LDB). Currently it is estimated that over one hundred thousand cases of Legionella occur annually. Cooling towers have been shown to be the source of LDB in some of the outbreaks. Ecological information indicates that the bacteria are present in many natural waters. Moreover, there is strong evidence that algal products can stimulate the growth of LDB. Because cooling tower environments may be conducive for growth and/or dispersal of LDB, a survey of both industrial and air-conditioning cooling towers for the presence of LDB was undertaken.

Tyndall, R.L.

1982-01-01

142

Atmospheric influences on natural-draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Atmospheric and moisture effects on natural-draught cooling towers were studied in a R + D project as a function of static wind load. A detailed measuring programme was set up for this purpose which registers and stores the necessary atmospheric data continously or at given times. The programme is constantly updated on the basis of the interim results obtained.

Stiller, W.

1983-06-01

143

Cooling tower and plume modeling for satellite remote sensing applications  

Energy Technology Data Exchange (ETDEWEB)

It is often useful in nonproliferation studies to be able to remotely estimate the power generated by a power plant. Such information is indirectly available through an examination of the power dissipated by the plant. Power dissipation is generally accomplished either by transferring the excess heat generated into the atmosphere or into bodies of water. It is the former method with which we are exclusively concerned in this report. We discuss in this report the difficulties associated with such a task. In particular, we primarily address the remote detection of the temperature associated with the condensed water plume emitted from the cooling tower. We find that the effective emissivity of the plume is of fundamental importance for this task. Having examined the dependence of the plume emissivity in several IR bands and with varying liquid water content and droplet size distributions, we conclude that the plume emissivity, and consequently the plume brightness temperature, is dependent upon not only the liquid water content and band, but also upon the droplet size distribution. Finally, we discuss models dependent upon a detailed point-by-point description of the hydrodynamics and thermodynamics of the plume dynamics and those based upon spatially integrated models. We describe in detail a new integral model, the LANL Plume Model, which accounts for the evolution of the droplet size distribution. Some typical results obtained from this model are discussed.

Powers, B.J.

1995-05-01

144

On-line performance monitoring of the natural draft cooling tower at Cardinal Plant  

Energy Technology Data Exchange (ETDEWEB)

The paper will provide an overview of the on-line performance monitoring system recently installed on the 630MW coal fired Unit 3 at the Cardinal Plant. Experience with using the on-line monitor to optimize performance of the major circulating water system components including the pumps, condensers and cooling tower will be discussed in the paper.

Michell, F.L.; Miller, M.J. [American Electric Power, Columbus, OH (United States)

1998-12-31

145

Structural deficiencies of natural draught cooling towers at UK power stations: Pt. 3; Strengthening of natural draught cooling tower shells  

Energy Technology Data Exchange (ETDEWEB)

The repair and strengthening of a number of concrete natural draught cooling towers have been completed by National Power. Strengthening works involve techniques developed by the CEGB, some of which are thought to be unique to this form of construction. The design and construction of external mantles around existing shells are described. Details are given of the use of fly ash concrete in cast in-situ mantles and of sprayed concrete work. Detailed survey and inspection techniques for concrete cooling tower shells are reported. The methods of assessment are discussed, and procedures for, and examples of, resin injection of cracked shells and a unique repair using parafil ropes as an external girdle to contain a tower shell against failure are presented. (author)

Woolley, G.R.; Van der Cruyssen, D. (National Power plc., Swindon (United Kingdom))

1994-02-01

146

Recent developments in the design of large cooling towers  

International Nuclear Information System (INIS)

The growth of power plant units has initiated the development of very large cooling towers. The shell curvature of such towers is comparably small producing an increase of bending effects due to loads with a non-uniform distribution, such as turbulent wind pressures. The validity of the current concept of equivalent static wind loads is inspected. Some deficiencies may occur underrating the actual stresses. A simplified, quasi-static method of calculation is described including dynamic loading data obtained from wind-tunnel tests. (Author).

1984-01-01

147

Nosocomial legionnaires' disease: epidemiologic demonstration of cooling towers as a source. [Legionella pneumophila  

Energy Technology Data Exchange (ETDEWEB)

Investigation of a recent outbreak of nosocomial legionnaires' disease - initially thought to be due to the documented presence of Legionella pneumophila in the hospital potable water - showed that aerosols from one or more cooling towers were the actual source of infection. From June 27 to Aug 25, 1983, nosocomial legionnaires' disease developed in 15 persons at a hospital in Rhode Island. Twelve (80%) of 15 case-patients occupied rooms in building 1, unit B, compared with eight (28%) of 29 control patients (odds ratio = 10.8; 95% confidence interval = 1.4 to 85.6). Subsequent investigation demonstrated that water in a cooling tower located 100 ft upwind of unit B was heavily contaminated with L. pneumophila, serogroup 1, subgroup 1, 2, 4, 5. The same strain was isolated from nine of the patients and from the make-up water for the tower. Active surveillance during the ten months following decontamination of the cooling tower identified no additional cases of nosocomial legionnaires' disease, although the hospital potable water had not been treated. While recommendations have been made for controlling nosocomial legionnaires' disease by heating or hyperchlorination of hospital potable water, this outbreak demonstrates the importance of an adequate epidemiologic-environmental investigation in choosing the appropriate control strategy.

Garbe, P.L.; Davis, B.J.; Weisfeld, J.S.; Markowitz, L.; Miner, P. Garrity, F.; Barbaree, J.M.; Reingold, A.L.

1985-07-26

148

Potential weather modification caused by waste heat release from large dry cooling towers  

International Nuclear Information System (INIS)

A numerical model of a cooling tower plume is employed to study the possible atmospheric effects of thermal plumes from natural draft dry cooling towers. Calculations are performed for both single and multiple towers, each of which can dissipate the waste heat from a nominal 1000 MWe power generating unit, and the results are compared with those for wet cooling towers associated with plants of the same generating capacity. Dry cooling tower plumes are found to have a higher potential for inducing convective clouds than wet cooling tower plumes, under most summertime meteorological conditions. This is due to the fact that both the sensible heat and momentum fluxes from a dry tower in summer are approximately one order of magnitude larger than those from a wet cooling tower

1979-01-01

149

Evaluation of plume potential and plume abatement of evaporative cooling towers in a subtropical region  

Energy Technology Data Exchange (ETDEWEB)

Hong Kong is a typical subtropical region with frequently high humidity in late spring and summer seasons. Plume from evaporative cooling towers, which service air-conditioning systems of civil buildings, has aroused public concerns since 2000 when the fresh water evaporative cooling towers were allowed to be used for high energy efficiency and environmental issues. This paper presents the evaluation of the plume potential and its effect on the sizing of the plume abatement system in a large commercial office building in Hong Kong for practical application. This evaluation was conducted based on a dynamic simulation platform using the typical meteorological year of Hong Kong since the occurrence of the plume heavily depends on the state conditions of the exhaust air from cooling towers and the ambient air, while the state condition of the exhaust air is determined by the total building cooling load and the control strategies of cooling towers employed mainly for improving energy efficiency. The results show that the control strategies have a significant effect on the plume potential and further affect the system design and sizing of the plume abatement system. (author)

Xu, Xinhua; Wang, Shengwei; Ma, Zhenjun [Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (China)

2008-08-15

150

Evaluation of plume potential and plume abatement of evaporative cooling towers in a subtropical region  

International Nuclear Information System (INIS)

Hong Kong is a typical subtropical region with frequently high humidity in late spring and summer seasons. Plume from evaporative cooling towers, which service air-conditioning systems of civil buildings, has aroused public concerns since 2000 when the fresh water evaporative cooling towers were allowed to be used for high energy efficiency and environmental issues. This paper presents the evaluation of the plume potential and its effect on the sizing of the plume abatement system in a large commercial office building in Hong Kong for practical application. This evaluation was conducted based on a dynamic simulation platform using the typical meteorological year of Hong Kong since the occurrence of the plume heavily depends on the state conditions of the exhaust air from cooling towers and the ambient air, while the state condition of the exhaust air is determined by the total building cooling load and the control strategies of cooling towers employed mainly for improving energy efficiency. The results show that the control strategies have a significant effect on the plume potential and further affect the system design and sizing of the plume abatement system.

2008-01-01

151

Evaluation of plume potential and plume abatement of evaporative cooling towers in a subtropical region  

Energy Technology Data Exchange (ETDEWEB)

Hong Kong is a typical subtropical region with frequently high humidity in late spring and summer seasons. Plume from evaporative cooling towers, which service air-conditioning systems of civil buildings, has aroused public concerns since 2000 when the fresh water evaporative cooling towers were allowed to be used for high energy efficiency and environmental issues. This paper presents the evaluation of the plume potential and its effect on the sizing of the plume abatement system in a large commercial office building in Hong Kong for practical application. This evaluation was conducted based on a dynamic simulation platform using the typical meteorological year of Hong Kong since the occurrence of the plume heavily depends on the state conditions of the exhaust air from cooling towers and the ambient air, while the state condition of the exhaust air is determined by the total building cooling load and the control strategies of cooling towers employed mainly for improving energy efficiency. The results show that the control strategies have a significant effect on the plume potential and further affect the system design and sizing of the plume abatement system.

Xu Xinhua [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Wang Shengwei [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)], E-mail: beswwang@polyu.edu.hk; Ma Zhenjun [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

2008-08-15

152

Biocide usage in cooling towers in the electric power and petroleum refining industries  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers users frequently apply biocides to the circulating cooling water to control growth of microorganisms, algae, and macroorganisms. Because of the toxic properties of biocides, there is a potential for the regulatory controls on their use and discharge to become increasingly more stringent. This report examines the types of biocides used in cooling towers by companies in the electric power and petroleum refining industries, and the experiences those companies have had in dealing with agencies that regulate cooling tower blowdown discharges. Results from a sample of 67 electric power plants indicate that the use of oxidizing biocides (particularly chlorine) is favored. Quaternary ammonia salts (quats), a type of nonoxidizing biocide, are also used in many power plant cooling towers. The experience of dealing with regulators to obtain approval to discharge biocides differs significantly between the two industries. In the electric power industry, discharges of any new biocide typically must be approved in writing by the regulatory agency. The approval process for refineries is less formal. In most cases, the refinery must notify the regulatory agency that it is planning to use a new biocide, but the refinery does not need to get written approval before using it. The conclusion of the report is that few of the surveyed facilities are having any difficulty in using and discharging the biocides they want to use.

Veil, J.; Rice, J.K.; Raivel, M.E.S.

1997-11-01

153

Evaluation and quantification of the impact of cooling tower emissions on indoor air quality  

Energy Technology Data Exchange (ETDEWEB)

Assessment of the potential impact of outdoor pollutant sources on indoor air quality through the reentrainment of pollutants vis-a-vis air-handling units, doorways, and windows has mainly focused on the evaluation of fume hood, boiler, diesel generator, and vehicular pollutant emissions. In recent years, however, gaseous and waterborne pollutants emitted from cooling towers have become an increasing source of concern. Chemicals such as biocides and corrosion and scale inhibitors are used to reduce and/or eliminate algae blooms, decrease bacterial and fungal growth, and reduce the corrosion of equipment. When added to the water used in cooling towers, these chemicals are emitted in both the gaseous phase and as pollutants dissolved in or suspended in water droplets. A qualitative evaluation of exhaust dispersion and droplet deposition rates associated with cooling towers is necessary when conducting an overall review of the environmental impact on indoor air quality. This paper identifies source emission rates to be used in assessing emissions of chemical additives in cooling towers, presents provisional design criteria for evaluating the impact of the chemical additives, and evaluates alternative methodologies for quantifying impact concentrations. These alternative assessment methodologies include numerical models, physical wind tunnel simulations, and computational fluid dynamics (CFD) simulations. Parameters used in comparing the methodologies include relative accuracy (order of magnitude) and modeling and simulation limitations.

Vanderheyden, M.D.; Schuyler, G.D. [Rowan Williams Davies and Irwin, Inc., Guelph, Ontario (Canada)

1994-12-31

154

Environmental impact of cooling towers of large nuclear power plants  

International Nuclear Information System (INIS)

The computer program for the calculation of the rise of cooling tower plumes (3-dimensional) was extented. In addition to the distributions of the vertical velocity, the temperatures and the specific humidity, it yields now the distribution of the rain droplets in the plume, too. The treatment of the cloud physics was based on the theory of Kessler (E. Kessler, Meteorological Monographs, 10 (1969) No. 32). (orig.)

1975-01-01

155

Legionella control in power station cooling towers using oxidising biocides  

Energy Technology Data Exchange (ETDEWEB)

Power stations have used oxidising biocides such as chlorine or bromine for many years to control microbial growth in their cooling towers. In this paper Ecolab trademark looks at the direct effect halogen concentration has on Legionella populations in order to determine the most effective halogenation rate required to ensure that the site key performance indicator (KPI) of < 100 colony-forming units (cfu) per mL can be maintained. (orig.)

Sailer, Christian; Rawlinson, Julia; Killeen, Paul [Ecolab PTY LTD, Ascot, WA (Australia)

2009-02-15

156

Gauging precipitation at power plant cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Testing the physical properties of pseudogleyied meadow soils these have been found to have a relatively small air capacity. The low land values as given to these soils from the ''Reichsbodenschaetzung'' are explained according to the formation of the soil profiles and the necessity of soil meliorations, with stagnation of water and air deficiency. After lowering the ground water table the soils have been freed from stagnant water and now the whole noncapillary porosity has been subjected to air supply. In relation to autochtonal soils derived from loess the air capacity of the pseudogleyied meadow soils is now equal to that of gray-brown podsolic soils.

Kapol, F.; Puls, K.E.

1983-04-01

157

Cooling tower, especially for medium and high power nuclear power plants  

International Nuclear Information System (INIS)

The auxiliary cooling equipment is designed to consist of a distribution conduit connected directly or via a valve to the rising channel or to the supply pipe with jets. The distribution conduit feeds cooling water into the jets operating as sprays. The equipment may be used for additional cooling of the nuclear power plant in case of accident or for a stable long-term minimum operational mode. The auxiliary cooling pump may be connected to deliver partly cooled water which will be further cooled in the inlet air stream or in ambient air. The water is transported through an auxiliary pipe to the distribution pipe and thus to the jets. Water from the jets is intercepted by a partition in the bottom. The design is presented of a cooling tower for a medium sized nuclear power plant with two PWR reactors with a heat output of 2x1375 MWth (2x440 MWe). The tower is designed for the take-off of ca 3.5% of the heat output of the reactor. (E.F.)

1979-02-23

158

A high vibration analysis for a cooling fan of the secondary cooling tower in HANARO  

International Nuclear Information System (INIS)

[en] HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, which is different from a power plant reactor, exhausts a fission heat generated from the reactor core into the atmosphere through a secondary cooling tower instead of an electric power production from the heat. During every one month inspection of the cooling tower, a No. 4 cooling fan gear reducer of the cooling tower recoded a high unstable vibration above the limit. To find the reason, a frequency analysis was conducted. It was conformed through the results of the frequency analysis that the frequency of the high vibration was 354 HZ which was calculated two times rotation of the pinion gear of the gear reducer. There was a broken of the gear surface of the pinion gear transferred the rotation power. After the repair of the pinion gear, the reducer was operated normally.

2009-01-01

159

Vibration Analysis of a Cooling Fan Gear Reducer of the Secondary Cooling Tower in HANARO  

International Nuclear Information System (INIS)

[en] HANARO is an open-tank-in-pool-type Korean research reactor that generates 30MW of thermal power. It differs from power plant reactor in that the heat generated by HANARO is exhausted into the atmosphere through a secondary cooling tower, thus maintaining the core temperature constant. During every monthly inspection of the cooling tower, large vibrations that exceeded the permissible limit were observed at cooling fan gear reducer No. 4 of the cooling tower. The purpose of this study is to identify the origin of the large vibration and to repair it. FFT spectrum analysis is performed to identify the part that caused the large vibration. The results of the frequency analysis showed that the vibration frequency was 354 Hz, which is twice the natural frequency of the pinion gear. A check of the pinion gear revealed that there was a crack on the surface of the pinion gear. After the gear was replaced, the reducer operated normally

2010-01-01

160

The quantity of algae colonizing the inside face of cooling towers and the consequences for wear of the shell  

International Nuclear Information System (INIS)

These studies are part of the interdirectorate working group's mandate relating to lifespan project on cooling towers. Involving the collaboration of several divisions of Electricity de France: the Construction Division (SEPTEN). The Generation and Transmission Division (SPT) and the Research and Development Division (EAA). Among the biological colonies which proliferate in the cooling circuits of power stations, algae are broadly represented in the form of wall coatings which cover the inside face of cooling towers: shell algae. They can also grow at other points in the cooling circuit; in the cold water basin, in the fill, and, in some cooling towers, in the hot water basin. These plant organisms hamper the operation of power stations by clogging the grids located in the pipe from the cold water basin to the condenser. In addition, when algae come free of the shell, they remove micro-fragments of the concrete, which could accelerate wear. This paper presents the findings of studies conducted by the Aquatic and Atmospheric Department on the infestation of cooling towers by algae. In particular, the results of studies to evaluate the quantity of algae on the inside face of the shell of cooling towers. Many scenarios will be proposed, linked to the operation of the plant and to the local meteorological conditions.

1990-06-02

 
 
 
 
161

A numerical study for performance analysis and design of a counterflow type cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A numerical study for performance analysis of a counterflow type natural draft cooling tower has been performed using the finite volume method with non-orthogonal body fitted, non-staggered grid system. For solving the coupling problem between water and air, air enthalpy balance, moisture fraction balance, water enthalpy balance, and water mass balance equations are solved with Navier-Stoke`s equations simultaneously. For the effect of turbulence, the standard k-{epsilon} turbulent model is implied in this analysis. The predicted result of the present analysis is compared with the experimental data and the commercial software result to validate the present study. The predicted results show good agreement with the experimental data and the commercial software result. To investigate the influence of the cooling tower design parameters such as approach, range and wet bulb temperature, parametric studies are also performed. (author). 15 refs., 11 figs., 8 tabs.

Lee, S.Y.; Lee, J.H. [Chung-Ang University Graduate School, Seoul (Korea, Republic of); Choi, Y.K.; Ryou, H.S. [Chung-Ang University, Seoul (Korea, Republic of)

1998-04-01

162

Origin and prevention of infection with Legionella pneumophila through cooling towers and evaporative cooling towers; Entstehung und Vermeidung von Legionelleninfektionen durch Kuehltuerme und Rueckkuehlwerke  

Energy Technology Data Exchange (ETDEWEB)

Evaporative cooling towers and industrial ventilator cooling towers have repeatedly been described as the origin of Legionnaires` disease. This article describes the design and function of cooling towers and evaporative cooling towers, sums up knowledge on the colonization of such systems with Legionella pneumophila, and describes conditions permitting the transmission of Legionella. Furthermore, design, maintenance, cleaning and disinfection measures are indicated which are believed to reduce the risk of infection through industrial and evaporative cooling towers. (orig.) [Deutsch] Rueckkuehlwerke klimatechnischer Anlagen und industrielle Ventilator-Kuehltuerme sind mehrfach als Ausgangspunkt von Legionellose-Epidemien beschrieben worden. In der vorliegenden Arbeit werden Aufbau und Funktion von Kuehltuermen und Rueckkuehlwerken erlaeutert, Erkenntnisse ueber die Besiedlung dieser Anlagen mit Legionellen zusammengefassten und die Situationen geschildert, in denen es zur Uebertragung von Legionellen kam. Darueber hinaus werden Konstruktions-, Wartungs-, Reinigungs-, und Desinfektionsmassnahmen aufgefuehrt, die zur Verminderung des Infektionsrisikos durch Kuehltuerme und Rueckkuehlwerke als wirksam angesehen werden. (orig.)

Schulze-Roebbecke, R. [Bonn Univ. (Germany). Hygiene-Institut; Richter, M. [Staatshochbauamt, Bonn (Germany)

1994-04-01

163

Cementitious stabilization of chromium, arsenic, and selenium in a cooling tower sludge  

Energy Technology Data Exchange (ETDEWEB)

The Federal Facility Compliance Agreement (FFCA) establishes an aggressive schedule for conducting studies and treatment method development under the treatability exclusion of RCRA for those mixed wastes for which treatment methods and capabilities have yet to be defined. One of these wastes is a radioactive cooling tower sludge. This paper presents some results of a treatability study of the stabilization of this cooling tower sludge in cementitious waste forms. The sample of the cooling tower sludge obtained for this study was found to be not characteristically hazardous in regard to arsenic, barium, chromium, lead, and selenium, despite the waste codes associated with this waste. However, the scope of this study included spiking three RCRA metals to two orders of magnitude above the initial concentration to test the limits of cementitious stabilization. Chromium and arsenic were spiked at concentrations of 200, 2,000, and 20,000 mg/kg, and selenium was spiked at 100, 1,000, and 10,000 mg/kg (concentrations based on the metal in the sludge solids). Portland cement, Class F fly ash, and slag were selected as stabilizing agents in the present study. Perlite, a fine, porous volcanic rock commonly used as a filter aid, was used as a water-sorptive agent in this study in order to control bleed water for high water contents. The highly porous perlite dust absorbs large amounts of water by capillary action and does not present the handling and processing problems exhibited by clays used for bleed water control.

Spence, R.D.; Gilliam, T.M.; Bleier, A. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.

1995-06-01

164

Cementitious stabilization of chromium, arsenic, and selenium in a cooling tower sludge  

International Nuclear Information System (INIS)

The Federal Facility Compliance Agreement (FFCA) establishes an aggressive schedule for conducting studies and treatment method development under the treatability exclusion of RCRA for those mixed wastes for which treatment methods and capabilities have yet to be defined. One of these wastes is a radioactive cooling tower sludge. This paper presents some results of a treatability study of the stabilization of this cooling tower sludge in cementitious waste forms. The sample of the cooling tower sludge obtained for this study was found to be not characteristically hazardous in regard to arsenic, barium, chromium, lead, and selenium, despite the waste codes associated with this waste. However, the scope of this study included spiking three RCRA metals to two orders of magnitude above the initial concentration to test the limits of cementitious stabilization. Chromium and arsenic were spiked at concentrations of 200, 2,000, and 20,000 mg/kg, and selenium was spiked at 100, 1,000, and 10,000 mg/kg (concentrations based on the metal in the sludge solids). Portland cement, Class F fly ash, and slag were selected as stabilizing agents in the present study. Perlite, a fine, porous volcanic rock commonly used as a filter aid, was used as a water-sorptive agent in this study in order to control bleed water for high water contents. The highly porous perlite dust absorbs large amounts of water by capillary action and does not present the handling and processing problems exhibited by clays used for bleed water control

1995-01-01

165

Studies on mathematical models for characterizing plume and drift behavior from cooling towers. Volume 2. Mathematical model for single-source (single-tower) cooling tower plume dispersion  

Energy Technology Data Exchange (ETDEWEB)

An improved model for natural-draft cooling tower plumes from single towers is presented. The model was developed through careful study of the systematic behavior of existing laboratory and field data and systematic testing of theoretical assumptions commonly employed in available plume models. Major model assumptions include bent-over plume; different spreading rates for momentum, temperature, and moisture; and an empirical treatment for plume downwash. Unknown experimental coefficients in the model were determined through calibration of model predictions with single-phase laboratory and visible plume field data. The model was also verified with new data not used in the calibration process. Our model provides an improvement in theory and performance over existing models and provides a correct representation of plume behavior at large wind speeds. This model is expanded to treat multiple tower plumes in Vol. 4.

Carhart, R.A.; Policastro, A.J.; Ziemer, S.; Haake, K.; Dunn, W.

1981-01-01

166

Rainfall enhancement due to scavenging of cooling tower condensate  

International Nuclear Information System (INIS)

[en] Estimates of rainfall enhancement resulting from scavenging of cooling tower condensate droplets were made using relevant aerosol scavenging theory and a range of meteorological conditions. For a large natural-draft tower, releasing 1.7 x 105 g/sec of condensate, plume centerline rainfall enhancement is predicted to be measurably high at downwind distances between 100 m and 1 km for moderate wind speeds and rainfall rates. The cumulative removal of condensate by scavenging should be significant, even in a light rain (1 mm/hr), where removal half-distances are predicted to be 2.5, 10, and 20 km for wind speeds of 1, 5, and 10 m/sec, respectively

1977-01-01

167

Operational cost minimization in cooling water systems  

Directory of Open Access Journals (Sweden)

Full Text Available In this work, an optimization model that considers thermal and hydraulic interactions is developed for a cooling water system. It is a closed loop consisting of a cooling tower unit, circulation pump, blower and heat exchanger-pipe network. Aside from process disturbances, climatic fluctuations are considered. Model constraints include relations concerning tower performance, air flowrate requirement, make-up flowrate, circulating pump performance, heat load in each cooler, pressure drop constraints and climatic conditions. The objective function is operating cost minimization. Optimization variables are air flowrate, forced water withdrawal upstream the tower, and valve adjustment in each branch. It is found that the most significant operating cost is related to electricity. However, for cooled water temperatures lower than a specific target, there must be a forced withdrawal of circulating water and further makeup to enhance the cooling tower capacity. Additionally, the system is optimized along the months. The results corroborate the fact that the most important variable on cooling tower performance is not the air temperature itself, but its humidity.

M.M. Castro; T.W. Song; J.M. Pinto

2000-01-01

168

Experience with the operation during winter of wet cooling towers with a varied concept of the main cooling system  

International Nuclear Information System (INIS)

On the basis of experience gained from cooling towers in operation it is prudent to operate 'in advance' new cooling towers in accordance with the load and air temperature to be expected. Experience during winter operation, which influences the design of new installations, has been accumulated from the cooling towers at Philippsburg and Grohnde nuclear power stations and also from those at the district heating power plant of Volkswagen at Wolfsburg. The measures taken cannot and should not totally prevent ice formation; however, with future expected methods of operation of cooling towers it is possible to foresee uninterrupted operation during winter. (orig.)

1985-09-27

169

Fire analog: a comparison between fire plumes and energy center cooling tower plumes  

International Nuclear Information System (INIS)

Thermal plumes or convection columns associated with large fires have been compared to thermal plumes from cooling tower systems to evaluate the fire analog concept. Energy release rate of mass fires is generally larger than that of single or small groups of cooling towers but may be comparable to proposed large energy centers. However, siginficant physical differences exist between cooling tower and fire plumes. Cooling tower plumes are usually dominated by ambient wind and turbulence conditions. Fire plumes, depending on fire intensity and area, can transform into free convection energy systems resulting in convective columns, strong inflow and updrafts, turbulence and concentrated vortices. Since these characteristics have not been observed with cooling tower plumes to date, the fire analog concept is questionable at this time. Additional research is needed on fire and cooling tower plumes.

1978-01-01

170

Effect of a cooling tower plume on the dispersion of a stack plume  

International Nuclear Information System (INIS)

The buoyancy of a cooling tower plume, rising in the atmosphere induces strong secondary flows in the surrounding air. At the side of the plume the flow direction is downward, beneath the plume the flow direction is upward. If a stack plume passes to the side of the cooling tower plume, it is shifted towards the ground. If the stack plume is released near the cooling tower plume, then the stack plume can be entrained and can rise together with the cooling tower plume. According to the position of the stack relative to the cooling tower the cooling tower plume will thus increase or decrease stack gas ground level concentrations. Furthermore, the location of the maximum of the ground concentration may be shifted towards the source. Results of wind tunnel experiments and their comparison with the results of a mathematical model are given. (orig.).

1987-01-01

171

Seismic response analysis of column supported natural draught cooling tower shells  

International Nuclear Information System (INIS)

Natural draught cooling towers (NDCTs) belong to the category of large civil engineering structures and are commonly used in nuclear or thermal power plants. Detailed dynamic analysis has to be carried out for design of cooling towers subjected to seismic excitation, considering the flexibility of the columns. Finite ring element formulations for dynamic analysis of cooling tower shell subjected to seismic excitation are presented in this paper. The geometry of a typical tall natural draught cooling tower is considered in this study for carrying out investigations. Transient response of the hyperbolic cooling tower shell subjected to earthquake loading has been analysed by direct time integration using acceleration-time history of North-South component of El-Centro earthquake. Parametric studies have also been carried out to study the influence of flexibility of column supports and damping on the seismic response of cooling tower shell and the results are discussed in the paper. (author)

2003-01-01

172

Effect of wind on the flow within the shell of a natural draught cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The shell effect of a natural draught cooling tower directly affects the cooling performance according to the level of the prevailing vacuum. However, if cold air passes over the edge of the tower crown into the inside of the cooling tower, the vapour rising from the inner wall of the shell is released as a result of the inflow of cold air and accelerates in a free buoyant flow. In this way, the vacuum in the cooling tower, and therefore, the flow of the cooling air diminish. The relationship and interactions between cooling air flow, wind velocity and cold air inflow on the one hand and cooling performance on the other hand have been investigated in numerous measurements on natural draught cooling towers.

Baer, E.; Ernst, G.; Wurz, D.

1980-11-01

173

Thermal investigation of ETRR-2 research reactor with different induced draft wet cooling tower  

International Nuclear Information System (INIS)

The thermal performance of nuclear reactor is directly affected by its cooling system. The cooling tower plays an important role in this cooling system to evacuate the heat generated in the nuclear reactor core. In this work simple mathematical model is used to compare a two cooling towers; the first cooling tower which operated in the reactor till 2003 and the second one (current) which replaced the first.in 2003, to predict a core inlet temperature and a cooling tower outlet temperature. The effect of ambient condition on the performance is measured. An Engineering Equation Solver program (EES) is used to simulate the integrated cooling system and the model is validated by readings from control room monitors in the reactor. The results showed better performance of the present cooling tower.

174

Fate of chlorine and chloramines in cooling towers; Henry's law constants for flashoff  

Energy Technology Data Exchange (ETDEWEB)

Chlorine and chloramines are volatile compounds which are stripped (flashed off) from recirculating cooling water systems by the large volumes of air which flow through the water cooling tower. The fraction of a volatile gas, such as hypochlorous acid (HOCl), which is removed by stripping is determined by Henry's constant H for that gas: H = (X/sub G/) / (X/sub L/), where X/sub G/ is the mole fraction of the gas in the air and X/sub L/ is the mole fraction of the gas in the water. H was measured for HOCl, OCl(-), NH/sub 3/, NH/sub 2/Cl, NHCl/sub 2/ and NCl/sub 3/ at 20 and 40 C. H = 0.076 for HOCl, compared to 0.71 for NH/sub 3/, at 20/sup 0/C. At 40/sup 0/C, H was about 2.5-fold larger for HOCl. This means that 10-15% of the HOCl is stripped from cooling water on each passage through a typical cooling tower. The measured flashoff of free available chlorine (HOCl + OCl(-)) was markedly pH-sensitive with a pK of 7.5, exactly as expected if HOCl is volatile but OCl(-) is not. The data permit a quantitative understanding of the fate of chlorine in cooling systems. The values of H at 40/sup 0/C for NH/sub 2/Cl, NHCl/sup 2/ and NCl/sub 3/ were 1.28, 3.76 and 1067. This means that all the chloramines are quickly stripped in cooling tower. 17 references, 7 figures, 1 table.

Holzwarth, G.; Balmer, R.G.; Soni, L.

1984-01-01

175

Venting flue gases from wet scrubbing-type desulfurization plants (chimneys and cooling towers)  

Energy Technology Data Exchange (ETDEWEB)

Pure gases resulting from the venting of flue gases through cooling towers need to be reheated. Access is given to the technologies and problems of cleaned flue gas reheating processes. Emphasis is on the two variants of the regenerative preheating of gases. Further sections are dedicated to the venting of cleaned flue gases through natural draught cooling towers. A comparative evaluation assesses the environmental loads caused by chimneys on one hand and natural draught cooling towers on the other hand. (orig./PW)

Leidinger, B.J.G.

1987-05-01

176

Effect of finned tube arrangement on the dimensions of natural draught dry cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Experimental investigations in connection with the dimensioning of natural draught dry cooling towers undertaken by the Department for Heat Transfer and Climatology are aimed at discovering favourable tube arrangements for the heat exchange system, which permit small construction size for such cooling towers. Systematic variations in tube spacing in the direction of flow and of tube arrangement in a system comprising spiral finned tubes indicate that optimum configurations are available for prescribed cooling performance in relation to tower dimensions.

Becker, N.; Renz, U.

1982-02-01

177

Designing a process cooling water system  

Energy Technology Data Exchange (ETDEWEB)

An efficient and economical operation depends on the choice of refrigeration equipment, cooling towers, or closed-circuit evaporative systems to provide the process cooling medium, the determination of the best coolant flow rates and temperatures, and the pumping, piping, and overall layout of the various components. Larry Bowman of Thermal Care/Mayer, Division of Midwesco, Inc., discusses considerations in designing a process cooling water system.

Bowman, L.

1987-05-14

178

Optimization of mechanical draft counter flow wet-cooling tower using artificial bee colony algorithm  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} ABC algorithm is used for optimization of counter flow wet-cooling tower. {yields} Minimizing the total annual cost for specific heat duty is the objective function. {yields} Six examples are presented to demonstrate the effectiveness of the proposed algorithm. {yields} The results are compared with the results of GAMS optimization package. {yields} The ABC algorithm can be modified to suit optimization of other thermal systems. -- Abstract: This study explores the use of artificial bee colony (ABC) algorithm for design optimization of mechanical draft counter flow wet-cooling tower. Minimizing the total annual cost for specific heat duty requirement is considered as objective function. Three design variables such as water to air mass ratio, mass velocity of water and mass velocity of air are considered for optimization. Evaluations of the cooling tower geometry and performances are based on an adaptive version of Merkel's method. Temperature and enthalpy constraints are included in the optimization procedure. Six examples are presented to demonstrate the effectiveness and accuracy of the proposed algorithm. The results of optimization using ABC are validated by comparing with those obtained by using GAMS optimization package. The effect of variation of ABC parameters on the convergence and optimum value of the objective function has also been presented.

Rao, R.V., E-mail: ravipudirao@gmail.co [S.V. National Institute of Technology, Surat, Gujarat State 395 007 (India); Patel, V.K. [S.V. National Institute of Technology, Surat, Gujarat State 395 007 (India)

2011-07-15

179

Effects of inlet relative humidity and inlet temperature on the performance of counterflow wet cooling tower based on exergy analysis  

International Nuclear Information System (INIS)

The purpose of this study is to analyze the influence of the ambient temperature and humidity on the performance of a counterflow wet cooling tower according to the second law, exergy analysis, of thermodynamics. First, the properties of water and air flow through the tower were predicted and validated by the experiment. Exergy analysis then has been carried out for investigating the cooling tower performance with various inlet air conditions, relative humidity and dry bulb temperature, while the water side condition is kept constant. According to the analysis in this paper, the similar result in terms of required dry air flow rate, exergy change of water and that of air, exergy destruction and second law efficiency were obtained for the various inlet air conditions. The exergy change of water ?xw is higher than that of air ?xair, since ?xw is the available energy of water to supply to air throughout the tower while ?xair is the available energy of air to recover or utilize that supplied by water. It reveals that ?xair is dominated by the exergy change of air due to evaporative heat transfer. In addition, it gives a clearer explanation of the cooling tower performance and gives clear trends for optimization.

2008-01-01

180

Emission of asbestos fibres from natural-draught cooling towers. Pt. 1 and 2  

International Nuclear Information System (INIS)

Sampling for the studies reported has been done in a relatively new nuclear power plant with natural-draught, wet cooling tower, and in an older, brown-coal fired power plant with the same type of cooling towers, both towers equipped with internal structures made of asbestos cement. Samples have been taken from the plumes, air in the environment, cooling water receiving tank, make-up water. The samples have been primarily examined for their content of asbestos fibres. The results show that relatively few asbestos is found in the environmental air and in the cooling water receiving tank. Putting it continuously, it can be said that the cooling water entrains only little amounts of the asbestos of the internal structures. The plume samples indicate emission of some thousand asbestos fibres per m3, or less than 1 ng. Taking into account one sample exhibiting an extremely high amount of asbestos, the average emission of asbestos fibres with the plumes is 106 fibres per m3, or 100 ng/m3 of plume. The maximum air pollution thus calculated in accordance with TA Luft (Clean Air Technical Directive), for the less favourable weather conditions at a hight of 2 m above ground, is 10 fibres per one m3 of air; including the extreme data of the single sample mentioned above, the result is some thousand fibres per m3. The data are far below the TRK data (Technical guiding data for maximum concentration at the place of work), which state a maximum of 106 fibres per m3. (orig.).

1985-01-01

 
 
 
 
181

Study plan for conducting a section 316(a) demonstration: K-Reactor cooling tower, Savannah River Site  

International Nuclear Information System (INIS)

The K Reactor at the Savannah River Site (SRS) began operation in 1954. The K-Reactor pumped secondary cooling water from the Savannah River and discharged directly to the Indian Grave Branch, a tributary of Pen Branch which flows to the Savannah River. During earlier operations, the temperature and discharge rates of cooling water from the K-reactor were up to approximately 70 degree C and 400 cfs, substantially altering the thermal and flow regimes of this stream. These discharges resulted in adverse impacts to the receiving stream and wetlands along the receiving stream. As a component of a Consent Order (84-4-W as amended) with the South Carolina Department of Health and Environmental Control, the Department of Energy (DOE) evaluated the alternatives for cooling thermal effluents from K Reactor and concluded that a natural draft recirculating cooling tower should be constructed. The cooling tower will mitigate thermal and flow factors that resulted in the previous impacts to the Indian Grave/Pen Branch ecosystem. The purpose of the proposed biological monitoring program is to provide information that will support a Section 316(a) Demonstration for Indian Grave Branch and Pen Branch when K-Reactor is operated with the recirculating cooling tower. The data will be used to determine that Indian Grave Branch and Pen Branch support Balanced Indigenous Communities when K-Reactor is operated with a recirculating cooling tower. 4 refs., 1 fig. 1 tab.

1991-01-01

182

Be cool, be flexible[Outsourcing for cooling water  

Energy Technology Data Exchange (ETDEWEB)

The article shows how outsourcing for cooling water can be the answer when the combination of excessive demand for electricity and high ambient temperatures can threaten supply. Global Water Technologies (GWT) through its subsidiary Psychrometric Systems Inc. can provide the additional cooling water with very little project investment from the generator, with no up-front capital commitment through its 'Performance Plus' outsourcing programme. The procedure is for GWT to use its own capital to install or upgrade a tower and for the customer to pay a monthly rental, or pay only for water used. The contract period is normally seven years, after which the customer has the option to purchase the tower. The advantages to the user of outsourcing for water are discussed.

O' Boyle, Paul [Global Water Technology, Golden, CO (United States)

1999-08-01

183

Demineralised water cooling in the LHC accelerator  

CERN Document Server

In spite of the LHC accelerator being a cryogenic machine, it remains nevertheless a not negligible heat load to be removed by conventional water-cooling. About 24MW will be taken away by demineralised water cooled directly by primary water from the LHC cooling towers placed at the even points. This paper describes the demineralised water network in the LHC tunnel including pipe diameters, lengths, water speed, estimated friction factor, head losses and available supply and return pressures for each point. It lists all water cooled equipment, highlights the water cooled cables as the most demanding equipment followed by the radio frequency racks and cavities, and by the power converters. Their main cooling requirements and their positions in the tunnel are also presented.

Peón-Hernández, G

2002-01-01

184

Magma cooling-tower process pilot-plant demonstration. Final report  

Energy Technology Data Exchange (ETDEWEB)

The Magma Cooling Tower (MCT) is a new process which offers a low energy approach for evaporation and concentration of waste water. A three month test program of the MCT portable pilot plant was conducted at the Sunrise Station of Nevada Power Company for the purpose of demonstrating this new technology. The MCT contains vertically oriented water-water-air falling film heat exchangers which are configured for indirect cooling of a primary fluid through evaporation of a secondary fluid into an air stream. The secondary fluid is contained in a circulating loop within the MCT and is composed of treated plant waste water. The secondary fluid is exposed primarily to low temperature non-metallic surfaces and can be maintained at very high dissolved solids levels. The principal objective of the program was to demonstrate the capability of the MCT to evaporate and concentrate waste water blowdown using low quality waste energy from the cooling water loop. A second objective was to demonstrate the control of scaling, fouling and corrosion in the high solids brine environment of the MCT secondary loop. Two modes of scale control were tested during the program. The first mode was based on chemical softening of makeup water to the secondary loop and was preferred for the NPC application. The second mode was baed on controlled crystallization of scale forming agents within the secondary circulating loop. The Magma Cooling pilot plant test was successful; and evaporation, scale control, and waste concentration were demonstrated. Results were within the limits predicted prior to the test. It was concluded that the Magma Cooling Tower is a viable mature technology which should be considered along with other water management techniques available to the industry.

Sanderson, W.G.

1981-05-01

185

A simulation-based method to analyse the behaviour of rc cooling towers shells  

International Nuclear Information System (INIS)

This paper deals with numerical simulations undertaken for the service life and maintenance management of EDF cooling towers. Following a presentation of the industrial context and of the numeric tools dedicated to RC structure ageing, two finite element models are presented. The first one aims at simulating the collapse of a tower fallen down in 1979, the second one is devoted to the assessment of damages undergone by cooling towers during the 1999 tempest in France. (authors)

2007-01-01

186

Testing and Evaluating the Stability of Coating Systems of the Interior Shells in Cooling Towers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Natural draught cooling towers are exceptional structures in every respect. Due to the enormous surface in connection with the diverse range of impacts from surrounding environment and operation, interior shells of cooling towers require particular protection. This is achieved by applying special p...

D?nu? T. Babor; Daniel Covatariu; Peer Heine

187

Solving the heat transfer in the cold rain of a cross flow cooling tower. N3S code - cooling tower release  

International Nuclear Information System (INIS)

A simplified model for heat and mass transfer in the lower rainfall of a counter-flow cooling toward had to be implemented in the N3S code-cooling tower release It is built from an old code: ZOPLU. The air velocity field is calculated by N3S. The air and water temperature fields are solved by a Runge-Kutta method on a mesh in an adequate number of vertical plans. Heat exchange and drags correlations are given. And all the necessary parameters are specified. All the subroutines are described. They are taken from ZOPLU and modified in order to adapt their abilities to the N3S requirements. (author). 6 refs., 3 figs., 3 tabs., 3 appends.

1996-01-01

188

Wind effects on optimal aerodynamic conditions for a wet cooling tower with natural draft  

International Nuclear Information System (INIS)

Among the problems of an aerodynamic nature, related to the wind action, the two following ones have to be studied through model tests to reach a better knowledge of design and operating conditions of counterflow natural draft wet cooling towers with water recovery systems. - Wind effects on performance. A very general phenomenon. In order to minimize this alteration, a common idea is to install radio windbrake walls. - Wind effects on the forces applied to the internal structures and thermal components. A relatively elaborate model, representative of a lower plenum layout was fitted with a sufficiently large number of pressure tapes to draw up the distribution of the pressure acting upon: - the packing, - the water recovery system, - the windbrake walls (eventually) and for various combination of these elements. The air flow mode in the tower was also observed. All these observations were made with different wind directions. This study showed that the forces were very variable geographically, very sensitive to the layout.

1988-01-01

189

Fire analog: a comparison between fire plumes and energy center cooling tower plumes  

International Nuclear Information System (INIS)

Past studies on the waste heat from thermal power plant cooling towers and proposed energy parks suggest that the dissipation of this waste energy may result in significant meteorological effects. Preliminary calculations have shown that the rate of atmospheric dissipation of the waste energy from groupings of cooling towers is approximately equal to that by geophysical phenomena such as thunderstorms, volcanoes, and large fires. Cumulus clouds and convective vortices often result from these natural energy releases. One of the geophysical analogs, the large fire, is evaluated in terms of how good a physical analog it is to cooling towers or groups of cooling towers. The literature on experimental and wild fires was reviewed in relation to how fire thermal plume characteristics may be typical of a thermal plume from cooling towers.

1978-01-01

190

Civil engineering peculiarities of the natural draught cooling tower at Voelklingen model power plant  

Energy Technology Data Exchange (ETDEWEB)

The natural draught cooling tower structure in its geometric dimensions does not represent a particularly difficult structural task. The arrangement of the flue gas desulphurization plant in the middle of the natural draught cooling tower required the incorporation of splash packing in a structure in front of the natural draught cooling tower. The abstraction of a mixture from the washed flue gases and the cooling tower vapour represented a very special chemical strain on the cooling tower inner surfaces. A very good homogeneous intermixing of both volume flows must be the basis of all considerations on the guaranteed security of the concrete surfaces. Test performances, engineering considerations and experience from related subject areas indicate the way for the construction of a qualitatively high value structure from the point of view of quality assurance.

Peters, H.L.

1984-06-01

191

Analysis Of Cooling Tower Performance From Safety Factor Of Kartini Reactor Operation  

International Nuclear Information System (INIS)

[en] Analysis of cooling tower performance from power generation of Kartini reactor has been done. The data's was observed with cooling tower coupled by plate and cylinder type heat exchanger. The Kartini reactor operated with nominal power at 100 k W during 24 hours and environmental data's observation have been done in ever 2 hours, Analysis and calculation used by Number of diffusion Unit and Enthalpy Balance Method to find NDU parameter. The NDU parameter is value heat transfer processing in cooling tower system. The NDU parameter used to find of safety factor and maintenance schedule of cooling tower. From analysis and calculation resulted value of NDU operation under of NDU design and performance of cooling tower is safe

1996-01-01

192

Thermal performance analysis of heat exchanger for closed wet cooling tower using heat and mass transfer analogy  

International Nuclear Information System (INIS)

[en] In closed wet cooling towers, the heat transfer between the air and external tube surfaces can be composed of the sensible heat transfer and the latent heat transfer. The heat transfer coefficient can be obtained from the equation for external heat transfer of tube banks. According to experimental data, the mass transfer coefficient was affected by the air velocity and spray water flow rate. This study provides the correlation equation for mass transfer coefficient based on the analogy of the heat and mass transfer and the experimental data. The results from this correlation equation showed fairly good agreement with experimental data. The cooling capacity and thermal efficiency of the closed wet cooling tower were calculated from the correlation equation to analyze the performance of heat exchanger for the tower

2010-01-01

193

Fog and drift deposition from evaporative cooling towers  

International Nuclear Information System (INIS)

[en] Methods of determining fog and drift deposition due to emissions from evaporative cooling towers are reviewed and formulas suggested that can be used as a basis for calculations. The Gaussian plume formula is recommended for calculating fog concentrations from which visibility can be estimated. For drift droplets with diameters greater than 200 ?m, deposition is calculated by ballistics methods, knowing the environmental wind speed and relative humidity and the vertical velocity of the plume and the droplet. Evaporation of the droplets is accounted for. Drift droplets with diameters less than 200 ?m are assumed to be dispersed according to the Gaussian plume formula, with the plume tilted downward to account for the settling speed of the droplet

1975-01-01

194

Studies on mathematical models for characterizing plume and drift behavior from cooling towers. Volume 4. Mathematical model for multiple-source (multiple-tower) cooling tower plume dispersion  

Energy Technology Data Exchange (ETDEWEB)

This volume presents a generalization of our single source model (presented earlier in Volume 2) to multiple sources. The generalized model can treat vapor plume dispersion from any number of cooling towers in any geometrical configuration in any orientation to the direction of the wind. Important characteristics of the model include: (1) methodology of plume merging which accounts for differing plume entrainment rates during merging depending on wind direction; and (2) treatment of the effects of tower downwash from multiple towers; namely, additional entrainment and an additional pressure drag force acting vertically. Limited calibration of the model to laboratory data was undertaken to determine two downwash coefficients. Verification of the model by comparing model predictions to new lab and field data revealed a superior performance of our model as compared to the models commonly used in environmental impact evaluation. The ANL multiple-source model predicts visible plume height within a factor of 2 and/or visible plume length within a factor of 2 1/2 in 80% of our field data test cases. For comparison, the Orville and Slawson-Wigley Models satisfy this criterion for only 67% and 49% of the time, respectively. Additional ANL Model improvement is possible mainly through further development of the plume merging criterion.

Policastro, A.J.; Carhart, R.A.; Wastag, M.

1981-01-01

195

Cooling tower drift studies at the Paducah, Kentucky Gaseous Diffusion Plant  

International Nuclear Information System (INIS)

The transfer and fate of chromium from cooling tower drift to terrestrial ecosystems were quantified at the Department of Energy's uranium enrichment facility at Paducah, Kentucky. Chromium concentrations in plant materials (fescue grass) decreased with increasing distance from the cooing tower, ranging from 251 +- 19 ppM at 15 meters to 0.52 +- 0.07 ppM at 1500 meters. The site of drift contamination, size characteristics, and elemental content of drift particles were determined using a scanning electron microscope with energy dispersive x-ray analysis capabilities. Results indicate that elemental content in drift water (mineral residue) may not be equivalent to the content in the recirculating cooling water of the tower. This hypothesis is contrary to basic assumptions in calculating drift emissions. A laboratory study simulating throughfall from 1 to 6 inches of rain suggested that there are more exchange sites associated with litter than live foliage. Leachate from each one inch throughfall simulant removed 3% of the drift mass from litter compared to 7 to 9% from live foliage. Results suggest that differences in retention are related to chemical properties of the drift rather than physical lodging of the particle residue. To determine the potential for movement of drift-derived chromium to surface streams, soil--water samplers (wells) were placed along a distance gradient to Little Bayou Creek. Samples from two depths following rainstorms revealed the absence of vertical or horizontal movement with maximum concentrations of 0.13 ppb at 50 meters from the tower. Preliminary model estimates of drift deposition are compared to depositionmeasurements. Isopleths of the predicted deposition are useful to identify areas of maximum drift transport in the environs of the gaseous diffusion plant

1979-01-24

196

Determination of realistic resonance factors for increasing the stability and durability of natural draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Measurement and design practises for natural draught cooling towers permit the design engineer to dimension the cooling shell and the supporting structure with knowledge of only global dynamic system parameters. The object of a research project carried out by the Institute for Statics and Dynamics at the Ruhr University was the critical testing of current procedures and the determination of dynamic peaking factors for overall internal stresses and also a wide variety of cooling tower geometries. It may be expected that the stability and durability of future natural draught cooling towers can be enhanced using the results of the research project.

Kraetzig, W.B.; Sanal, Z.

1987-01-01

197

Equipment to separate liquid droplets from the cooling air stream of a liquid cooling tower  

International Nuclear Information System (INIS)

In order to separate off liquid droplets from the air stream of a cooling tower, one uses separator blades that are secured to the supporting construction. An improvement on this is proposed to make the repairs easier. According to the invention, the separator blades should be fabricated from springy material with self-supporting strength and can be fitted onto the supporting construction by means of slits and notches. (RW)

1977-01-01

198

Cooling towers: design and performance (citations from the Engineering Index Data Base). Report for 1970-August 1978  

International Nuclear Information System (INIS)

Abstracts from worldwide research on design and performance of mechanical draft and natural draft wet, dry, and dry-wet combination cooling towers are discussed. Citations cover studies on size reduction, corrosion protection, and economic optimization of cooling towers primarily used with nuclear power plants and fossil fuel power plants. A few abstracts pertain to cooling towers used in wastewater treatment

1978-01-01

199

Cooling water distribution system  

Energy Technology Data Exchange (ETDEWEB)

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

Orr, Richard (Pittsburgh, PA)

1994-01-01

200

Dispersion of droplets from natural draft cooling towers under special meteorological conditions  

Energy Technology Data Exchange (ETDEWEB)

From natural draft cooling towers, recondensated as well as spray droplets are emitted. This may cause precipitation to occur in the environment of the cooling towers under particular meteorological conditions. The following statements deal with this phenomenon. They are based on theoretical studies partly performed within the scope of the waste heat project for the Upper Rhine area. The calculations were made with the three-dimensional cooling tower plume model WALKUERE. Two cases were selected to represent particular meteorological conditions. The first of these conditions assumes primary precipitation directly from the plume. This is compared with secondary precipitation occurring in the second case. This secondary precipitation emerges from a cumulus cloud developing out of the cooling tower plume and raining out. Apart from the precipitation fields leeward of the cooling towers the model also yields the distribution of the vertical velocity, the specific humidification as well as the rain drop content per cross-section of various distants from the cooling towers. The distribution of precipitation partly is understood only if these fields are known. The influence exerted by the number of cooling towers and their arrangement on the precipitation distribution with respect to wind velocity is shown by the example of the first meteorological condition.

Nester, K.

1980-01-01

 
 
 
 
201

Models for the calculation of operational performance and of emissions from natural draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The cold water temperture, plume temperature, plume emission and droplet content of the plume can be calculated by means of a simple mathematical model for various environmental conditions. Measured values totalling five measured regimes of the natural draught wet cooling tower associated with the 300 MW C unit at RWE's Neurath power station were used for matching the model and were compared with the values computed from the model. The structure of the computer model is described in detail. All the computation sequences can be performed with a pocket calculator. The close agreement between computed and measured values is demonstrated.

Dittrich, H.; Ernst, G.; Wurz, D.

1980-10-01

202

Effect of wind on performance of a dry-cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The influence of cross-winds on the performance of a natural draft dry-cooling tower is investigated by means of full scale measurements. By monitoring all the relevant independent variables, the results of these measurements allow direct comparison with the wind effect predicted by numerical procedure employing the PHOENICS code. It is shown that results obtained on full scale towers can be successfully reproduced provided that the effects of all tower components are included in the analysis. In practical cooling towers rectangular heat exchanger bundles are arranged either vertically around the circumference of the tower or in the horizontal inlet cross-section of the tower and the wind is found to be dependent on the particular layout. (Author)

Du Preez, A.F.; Kroeger, D.G. (Stellenbosch Univ. (South Africa). Dept. of Mechanical Engineering)

1993-03-01

203

Results of measurements on cooling tower plumes compared with model calculations  

International Nuclear Information System (INIS)

In autumn 1974 measurements were made on the natural-draft cooling towers of the brown-coal power plant in Neurath (BRD) as part of a project on the micro climate of cooling towers. The thermal outlet of the whole plant responsible for the climatic disturbances is equal to 2000 MW. These measurements of cooling tower plumes set the necessary foundations for the calibration of plume simulation models. A short description of the field measurements is given together with some properties of the measurement systems used and an explanation of the measured physical data. The most important results are compared with those from calculation of a simulation model developed at EIR. (Auth.).

1979-01-01

204

Chlorination/dechlorination studies relating to proposed cooling towers for K and C reactors  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to obtain data on the chlorination and dechlorination of the cooling water that is pumped through the C- and K-Reactor heat exchangers. More specifically, data were obtained on: (1) chlorine demand and dissipation rates; (2) the effectiveness of sodium sulfite as a dechlorinating agent; (3) the toxicity of chlorination and dechlorination on indigenous fish; (4) the effects of dechlorination on water quality; and (5) the comparative precision of three conventional residual chlorine detection methods. The study results strongly indicate that implementation of present plans for chlorination and dechlorination (with sodium sulfite) of SRP reactor cooling towers will cause no significant adverse environmental impacts and should not result in problems in meeting future regulatory guidelines for TRC. 9 figs., 11 tabs.

Wilde, E.W.

1986-12-01

205

Sunrise tower - Cool technology in an aesthetically-pleasing wrapping; Coole Technik in aesthetischem Kleid  

Energy Technology Data Exchange (ETDEWEB)

This first article in a series of two describes a new, twin-tower office complex in Zurich, Switzerland, that features a special facade construction. The 26 and 21-storey twin towers in northern Zurich feature latest facade technology. The selection of a constructional principle for the realisation of the facade is described. Two variants for the construction are compared - a naturally-ventilated double facade and the 'spent-air' facade. The functioning of the facade and its characteristics are examined and the building technical services of the complex are described. These feature the use of the neighbourhood's district heating system, free-cooling systems and thermally-activated building elements.

Schadegg, E.; Glauser, A.

2004-07-01

206

Characteristic curves of resistance in natural-draught wet cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The determination of the characteristic curves of the resistance in natural-draught wet cooling towers is connected with difficulties. They are mainly due to the measurement of the resistance coefficients of the various cooling tower elements. The measurement of the resistance coefficient for the air inlet is particularly difficult, as it is mostly determined by measurements on models. The comparison of investigations by different authors shows considerable variations in this respect. It can be presumed that these variations are caused by unequal conditions of modelling. The author points out that one has to take different flow conditions into consideration - thus the flow within large cooling towers corresponds approximately to the flow in free space - and that the resistance coefficients have to be determined under such conditions. These relations are shown by the measuring results gained from large natural-draught wet cooling towers.

Mikyska, L.

1985-05-01

207

Demolition of Cooling Towers from the World's First Commercial Reactors - the Nuclear Factor  

International Nuclear Information System (INIS)

[en] The demolition of hyperbolic cooling towers would be a relatively routine demolition project because the method of demolition has been proven straightforward and repeatable with the successful demolition of over 200 similar structures in the last 30 years. This paper will detail the unique aspects of the planning and execution of the cooling tower demolition project due to its location on a nuclear site and proximity to active nuclear operations. (authors)

2006-03-02

208

Ring-stiffened shell of the ISAR II nuclear power plant natural-draught cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The natural-draught cooling tower of the ISAR II nuclear power plant is one of the largest in the world. The bid specifications provided for an unstiffened cooling tower shell. For the execution, however, it was decided to adopt a shell with three additional stiffening rings. The present contribution deals with the static and dynamic calculations of the execution and, in particular, with the working technique employed for the construction of the rings.

Form, J.

1986-07-01

209

Retrofitting of big natural draft cooling towers as flue gas issue  

Energy Technology Data Exchange (ETDEWEB)

After a detailed plant analysis the Rheinisch-Westfaelische Elektrizitaetswerke AG decided in 1984 to emit their purified flue gases via the existing natural draught cooling towers. This meant that two openings with a diameter up to 10 m had to be made in the thin-walled cooling tower shells to accomodate the flue gas pipes. The reconstruction measures were projected for Weisweiler, Neurath, Frimmersdorf, and Niederaussem. The new system is already at work in the Weisweiler and Frimmersdorf plants.

Stoffregen, U.

1987-02-01

210

Loy Yang power - cooling tower chemical dosing implementation: practical findings  

Energy Technology Data Exchange (ETDEWEB)

From early 2001, GE Betz were given the opportunity to treat the Loy Yang power station cooling water systems to control microbiological activity and corrosion of the copper-based metallurgy in those systems. After commencing with continuous dosing of sodium hypochlorite as the biocide and the traditional tolyltriazole (TTA) as the copper corrosion inhibitor, the treatment program was optimised over the next year of operation. Sodium hypochlorite efficiency was determined by monitoring of both Legionella and total bacteria to determine the effectiveness of the biocide program and by using oxidation reducing potential to measure on-line the activity of the biocide. Copper corrosion inhibitor efficiency was determined using the on-line linear polarisation resistance technique (corrator), corrosion coupons and by measuring copper concentrations in the recirculating cooling water. (orig.)

Lindsay, J. [BetzDearborn, Latrobe Valley (Australia)

2004-06-01

211

4. Meeting on cooling towers. From practice - for practice; 4. Kuehlturm-Tagung. Aus der Praxis - Fuer die Praxis  

Energy Technology Data Exchange (ETDEWEB)

The 4th Cooling Tower meeting brought into focus aspects of economic efficiency of the water cooling system, i.e. the papers analyse investment cost and operating cost taking into account environmental policy and interests. Numerous examples from practice are discussed in the papers showing how wet cooling tower design and application-specific selection of design features can influence the performance of the entire system. (orig./CB) [Deutsch] Im Mittelpunkt der 4. Kuehlturm-Tagung steht die Wirtschaftlichkeit der Wasserrueckkuehlanlage, d.h. die Betrachtung der Investitions- und Betriebskosten unter Beruecksichtigung der Belange des Umweltschutzes. Mit Beispielen aus der Praxis zeigen die Referenten, wie sich die Auslegung und Auswahl eines Nasskuehlturms auf das Betriebsergebnis der Anlage auswirken. (orig./GL)

NONE

1998-09-01

212

An ultrasensitive fouling monitoring system for cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Fouling in industrial water has been a serious problem for many years. For example, the deterioration of the efficiency of heat exchangers and the occurrence of corrosion can cause cooling water leakage into the process streams. Biocides, dispersants, and filtration systems typically are used to prevent these problems. However, if these treatment programs are started too late, the early stages of fouling can occur. Here, a simple method for assessing fouling and chemical treatment efficiency is described. An ultrasensitive fouling sensor that uses piezoelectric quartz crystals was developed which detects fouling in the early stages.

Nohata, Y. [Hakuto Co. Ltd., Yokkaichi (Japan); Taguchi, H. [Mie Univ., Tsu (Japan)

1995-03-01

213

Cooling tower or dry cooler? Effects of legionella regulations for cooling towers; Koeltoren of drycooler? Effecten van legionella beleidsregels inzake koeltoren  

Energy Technology Data Exchange (ETDEWEB)

Results of a study on parameters for the use of open cooling towers and comfort installations are presented. Special attention is paid to the advantage of applying dry cooler in a comfort installation, taking into account regulations for the prevention of legionella. [Dutch] In dit artikel worden argumenten aangedragen waarom in comfortkoeling beter een drycooler kan worden toegepast.

Postema, H.C. [Raadgevend Ingenieursbureau Boonstoppel, Nijmegen (Netherlands)

2003-04-01

214

A cooling water system copper corrosion study  

Energy Technology Data Exchange (ETDEWEB)

The plant has four units that have been operating normally for 12--33 years. Two of the units are 70 MW sister units that have copper alloy once-through condensers. The other two units are 350 MW and 500 MW units with copper alloy condensers and cooling towers. No cooling water related tube leaks had been experienced. Until 1993, the only chemicals used were sulfuric acid for pH control of the cooling tower systems and chlorine for biological control. The units were chlorinated for one hour per day per condenser. In early July 1992, their copper grab sample at the plant discharge to the river exceeded the weekly environmental limit. In fact, it was so high that there was a slim chance of coming in under their monthly average copper limit unless something was done quickly. The result of this incident was an extensive study of their plant wastewater and cooling systems. The study revealed that the elevated copper problem had existed sporadically for several years. Initially, copper control was achieved by altering the wastewater treatment processes and cooling tower blowdown flow path. Two extended trials, one with tolyltriazole (TTA) and one with a chemically modified benzotriazole (BZT) were performed. Optimal control of copper corrosion was eventually achieved by the application of a TTA treatment program in which the feed rates are adjusted based on on-line corrosion monitoring measurements. This report documents experiences and results over the past six years.

Pulkrabek, J.W.

1998-07-01

215

What comes out of the Goesgen cooling tower. A poll shows that the Romands above all are a long way from seeing water vapor in it  

Energy Technology Data Exchange (ETDEWEB)

The results of a poll of 500 people (118 French-speaking Swiss, and 382 German-speaking Swiss) to find out what they think is discharged into the atmosphere by the Goesgen reactor, are discussed. It seems that, in general, the French-speaking Swiss (Romands) think that there is more pollution in the water vapor than do the German-speaking Swiss.

1983-02-19

216

A comparison of cooling tower systems. Analysis of high-efficiency closed hybrid-medium counter-current cooling system; Koeltorensystemen vergeleken. Analyse hoog rendement gesloten hybride-mediumterugkoeler  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are also utilized in climate technique to dispose of process heat. Water use, the added chemicals and the cleaning cost constitute the largest debit items in exploitation. Open wet cooling towers use water all through the year. The closed hybrid medium blast cooler only uses water in the summer. (mk) [Dutch] Koeltorens worden, ook in de klimaattechniek, ingezet om proceswarmte af te voeren. Het waterverbruik, de toegevoegde chemicalien en de schoonmaakkosten behoren tot de grotere kostenposten in de exploitatie. Open natte koeltorens verbruiken het hele jaar door water. De gesloten hybride-mediumterugkoeler verbruikt alleen water in de zomer.

Huizinga, H.T. [Heat Transfer Holland, Zuidwolde (Netherlands)

2008-03-15

217

Optimization of water-cooled chiller system with load-based speed control  

Energy Technology Data Exchange (ETDEWEB)

This study investigates the energy performance of chiller and cooling tower systems integrated with variable condenser water flow and optimal speed control for tower fans and condenser water pumps. Thermodynamic-behaviour chiller and cooling tower models were developed to assess how different control methods of cooling towers and condenser water pumps influence the trade-off between the chiller power, pump power, fan power and water consumption under various operating conditions. Load-based speed control is introduced for the tower fans and condenser water pumps to achieve optimum system performance. With regard to an example chiller system serving an office building, the optimal control coupled with variable condenser water flow could reduce the annual system electricity use by 5.3% and operating cost by 4.9% relative to the equivalent system using constant speed fans and pumps with a fixed set point for cooling water temperature control.

Yu, F.W. [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Hong Kong (China)], E-mail: befwyu@polyu.edu.hk; Chan, K.T. [Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom, Hong Kong (China)

2008-10-15

218

Optimization of water-cooled chiller system with load-based speed control  

International Nuclear Information System (INIS)

This study investigates the energy performance of chiller and cooling tower systems integrated with variable condenser water flow and optimal speed control for tower fans and condenser water pumps. Thermodynamic-behaviour chiller and cooling tower models were developed to assess how different control methods of cooling towers and condenser water pumps influence the trade-off between the chiller power, pump power, fan power and water consumption under various operating conditions. Load-based speed control is introduced for the tower fans and condenser water pumps to achieve optimum system performance. With regard to an example chiller system serving an office building, the optimal control coupled with variable condenser water flow could reduce the annual system electricity use by 5.3% and operating cost by 4.9% relative to the equivalent system using constant speed fans and pumps with a fixed set point for cooling water temperature control.

2008-01-01

219

Nonlinear analysis of safety, damage and lifespan of wind-loaded natural draft cooling towers  

International Nuclear Information System (INIS)

While being important and optically impressive components of thermal power plants, natural draught cooling towers are in effect comparatively thin shell structures that must withstand hurricane force winds. As past experience has proven, current German design and analysis concepts implicitly lead to safe structures, but due to their linear-elastic background they cannot supply answers to questions dealing with realistic collapse loads, failure mechanisms and estimations of life expectancies. In this paper, appropriate computer-based nonlinear analysis concepts are presented which deal with those aspects. After a short exposition of the theoretical background for modeling tower shells as multi-layered shell continua by mixed finite elements under consideration of shear deformations, the approach is demonstrated through numerical simulation of collapse loads and failure modes of the Gundremmingen cooling towers. Based on the methodology presented, appraisals of reduced life times for hurricane-damaged towers, as well as different repair and retrofitting strategies can be carried out. (orig.).

1992-01-01

220

Influence of cooling towers and mountain ridges of plume dispersions from nuclear power plants  

International Nuclear Information System (INIS)

Calculation of atmospheric dispersion of stack-released air pollutants by the Gaussian model is not applicable if the plume is affected by high buildings, especially cooling towers, or mountain ridges. Since for such distortions of plume dispersion calculation models for use in practice are lacking, experiments in two 'atmospheric' wind tunnels were done to investigate the influence of cooling towers (out of action or in operation respectively) and two-dimensional ridges on plume dispersion. Investigations were done for stacks in flat terrain, for one or two nearby cooling towers and for ridges of different shapes upwind and downwind from the stack. The concentration of stack-released tracer-effluents was measured along, across and vertical to the atmospheric flow direction. Measurements show a variation of horizontal and vertical plume spreading and height of plume center line compared with the undisturbed flow in relation to the position upwind or downwind, the height difference and distance between stack and cooling tower or ridge and the fact, whether the cooling tower is in operation or not. Guidance is given how to modify the parameters of the Gaussian plume model describing horizontal and vertical plume spreading and effective release height to take into account ground level concentrations for distorted plumes as measured in the wind tunnel in a good approximation. (orig.).

1988-01-01

 
 
 
 
221

Investigations into the optimum shell contours for natural draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

On natural draught cooling towers it has been observed that with very low wind speeds, in particular total calm, reductions in output have occurred due to ingress of cold air. Generally, as a remedial measure, the outlet diameter for the hyperbolic shell in relation to the diameter of the waist of the tower has been reduced and in a few extreme cases reduced even further. The effects on structural design and thermodynamic performance for different contours are compared.

Tesche, W.

1984-09-01

222

Thermal performance of cross flow cooling towers in variable wet bulb temperature  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are widely used in most industrial units to reject waste heat to the atmosphere. Wet towers are usually designed to operate in hot and dry weather conditions with narrow range of wet bulb temperature, but many cooling towers are required to operate in weather condition with large variation of wet bulb temperature which strongly affects the thermal performance of the towers. In this paper a conventional mathematical model is used to predict the thermal behavior of an existing cross flow tower under variable wet bulb temperature and the results are compared with experimental data in various operating conditions. Available fill characteristic curve of the tower is obtained to estimate its departure from the design conditions. It is found that when the wet bulb temperature increases, the approach, range and evaporation loss would increase considerably. Variation of evaporation loss versus wet bulb temperature was estimated. Finally the effect of placing an impact separator in front of air louvers on thermal performance of the tower is investigated. (author)

Hajidavalloo, Ebrahim [Mechanical Engineering Department, Shahid Chamran University, Ahvaz (Iran); Shakeri, Reza; Mehrabian, Mozaffar A. [Mechanical Engineering Department, Shahid Bahonar University of Kerman, Kerman (Iran)

2010-06-15

223

Water cooled steam jet  

Energy Technology Data Exchange (ETDEWEB)

A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed there between. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock. 2 figs.

Wagner, E.P. Jr.

1999-01-12

224

Water cooled steam jet  

Energy Technology Data Exchange (ETDEWEB)

A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

Wagner, Jr., Edward P. (Idaho Falls, ID)

1999-01-01

225

Water-cooled electronics  

CERN Document Server

LHC experiments demand on cooling of electronic instrumentation will be extremely high. A large number of racks will be located in underground caverns and counting rooms, where cooling by conventional climatisation would be prohibitively expensive. A series of tests on the direct water cooling of VMEbus units and of their standard power supplies is reported. A maximum dissipation of 60 W for each module and more than 1000 W delivered by the power supply to the crate have been reached. These values comply with the VMEbus specifications. (3 refs).

Dumont, G; Righini, B

2000-01-01

226

Comparison of wet and dry heat transfer and pressure drop tests of smooth and rough corrugated PVC packing in cooling towers  

International Nuclear Information System (INIS)

This paper presents the results of an experimental investigation of the performance of a cooling tower with PVC packing. The following were examined; the effect of surface roughness, the effect of the angle of roughness and the effect of packing spacing. The investigation was divided into two parts: comparison of film heat transfer with air pressure drop, without water circulation and comparison of enthalpy change and pressure drop in the model cooling tower, with circulation of water. Seven commercial packing were investigated, covering a size range of 1.1

1998-01-01

227

Crossed streams cooling tower with anti-freezing system. Refrigerant atmospherique a courants croises equipe d'un systeme antigel  

Energy Technology Data Exchange (ETDEWEB)

In this cooling tower the anti-freezing system is made by two mobil barriers which limit the surface of the exchange zone between air and water (only one part of the annular upper tank is used). An overflow pipe is used for limiting the water load in the upper tank.

Gautier, D.

1987-08-07

228

A complete model of wet cooling towers with fouling in fills  

Energy Technology Data Exchange (ETDEWEB)

A cooling tower basically consists of three zones; namely, spray zone, packing and rain zones. In cooling towers, a significant portion of the total heat rejected may occur in the spray and rain zones. These zones are modeled and solved simultaneously using engineering equation solver (EES) software. The developed models of these zones are validated against experimental data. For the case study under consideration, the error in calculation of the tower volume is 6.5% when the spray and rain zones are neglected. This error is reduced to 3.15% and 2.65% as the spray and rain zones are incorporated in the model, respectively. Furthermore, fouling in cooling tower fills as well as its modeling strategy is explained and incorporated in the cooling tower model to study performance evaluation problems. The fouling model is presented in terms of normalized fill performance index ({eta}{sub F,norm}) as a function of weight gain due to fouling. It is demonstrated that the model is asymptotic, which is similar to typical asymptotic fouling model used in conventional heat exchangers. (author)

Qureshi, Bilal A.; Zubair, Syed M. [Mechanical Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Mail Box 1474, Dhahran 31261 (Saudi Arabia)

2006-11-15

229

Improved model for natural and mechanical-draft cooling tower plume rise  

Energy Technology Data Exchange (ETDEWEB)

Based on previous model validation work, an improved model was developed for single and multiple cooling tower plume rise. The model adopts a one-dimensional integral approach, is applicable to both natural- and mechanical-draft cooling tower plumes and treats the effects of wind direction and variable cross-section on plume merging. Assumptions are made which help resolve the usual difficulties of correctly predicting both plume trajectory and dilution, and of achieving the correct balance of thermodynamic effects. The model treats the effects of tower downwash for both natural- and mechanical-draft plumes by means of additional entrainment and a downward pressure force. The multiple-source plume merging method accounts for different rates of entrainment depending on the degree of non-circularity of the plume cross-section and on the orientation of the merging plumes to the wind direction. The model was calibrated with selected laboratory data (from Battelle Northwest Lab (BNL) and Electricite de France (EDF)) and field data (from Chalk Point, Lunen, Paradise). The model was then verified by comparing its predictions with field data from the Amos and Neurath natural-draft cooling towers (NDCTs), and from the Gaston and Benning Road mechanical-draft cooling towers (MDCTs). Additional verification was provided by model/data comparisons with new single-phase laboratory data from EDF, BNL, and other sources. The overall predictive capability of the model is good.

Carhart, R.A.; Policastro, A.J.; Wastag, M.; Haake, K.

1980-01-01

230

Influence of the shape of natural-draught cooling tower on its thermal properties  

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the question whether various shapes of natural-draught cooling towers influence their thermal properties. For this purpose, the geometrical influencing values, such as inlet diameter, outlet diameter, height, draught level and the minimum cross-section of the heat-exchanging structures, are subject to variation. The calculation model, the limiting conditions, the characteristic influencing factors (dry and wet cooling tower) and the calculation results are shown. The result is that the geometrical shape has only little influence on the main thermal design data.

Kast, W.; Klan, H.

1987-03-01

231

Flow resistance, velocity distribution and optimal height for air intake in natural draught cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The authors investigate with the help of a model air resistances in natural draught cooling towers. Hereby are of special interest the amount of intake and deviation losses at the base of the tower and the flow resistances caused by the cooling stack. The experimental set-up and executation, the velocity distribution above the installations, the determined flow resistance coefficients and the optimal height for air intake are described keeping investment and operational costs at a minimum. A numerical example shows how the optimal height can be determined.

Hempel, D.C.; Stephan, K.; Hesse, G.

1983-11-01

232

Cooling tower construction. VGB specification for layout, calculation, design and construction of cooling towers. BTR Bautechnik bei Kuehltuermen. VGB-Richtlinie fuer den bautechnischen Entwurf, die Berechnung, die Konstruktion und die Ausfuehrung von Kuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

The specification is the basis for the preparation of offers and the construction of natural-draught cooling towers. It comprises data for load assumptions, calculation, design and construction which are necessary for the construction of shell-type cooling towers. (DG).

1990-01-01

233

Optimization of guide vane positions in bended inflow of mechanical draft wet-cooling tower  

Science.gov (United States)

Optimization of vane positions in a mechanical draft wet-cooling tower is presented in this paper. The originally installed, equally spaced, vanes produced non-uniform air velocity distribution reducing the performance of the fill of the cooling tower. A 2D CFD model of the tower has been created. The model has then been used to determine the objective function in the optimization procedure. The selected objective function was the standard deviation of the velocity of air entering the fill. The Goal Driven Optimization tools of the ANSYSWorkbench 2.0 have been used for the optimization and the ANSYS Fluent 13.0 as a flow solver. The optimization allowed reduction of the objective function and producing a more uniform air flow.

Klimanek, Adam; Musio?, Tomasz; Stechman, Adam

2011-12-01

234

Wind dependence on the flow rate in a natural draught cooling tower  

International Nuclear Information System (INIS)

[en] The efficiency of a natural draught cooling tower depends, among other things, on the effect of the wind on the flow in the tower stack. Determinations were made on a natural draught wet cooling tower 100 metres high, for the purpose of studying this effects. As characteristic quantity, a typical height was determined, the values of which were worked out from the results of the measurements. The efficiency of the stack is affected the most in the case of average wind velocities (when the velocity of the wind is about equal to the mean velocity of the plume). This effect diminishes when the velocity of the wind increases. In the case of average wind velocities, the direction of the wind has an effect, owing to the neighbouring buildings; for slightly greater wind velocities, no effect could be found

1981-01-01

235

Improvement of mathematical models for plume rise and drift deposition from cooling towers  

International Nuclear Information System (INIS)

[en] New models for plume rise and salt-drift deposition from cooling towers and presented. For plume rise, assumptions are made which help resolve the usual difficulty of correclty predicting both plume trajectory and dilution. The multiple-tower plume merging method accounts for different rates of entrainment depending on the orientation of the merging plumes with the wind direction. Model calibration and verification have been made with field and laboratory data from natural- and mechanical-draft cooling towers. For salt-drift deposition modeling, new droplet breakaway and droplet evaporation formulations are developed. The drop evaporation treatment accounts for the usually important effects of droplet salt-concentration gradients. The drift model has been validated with field data taken at the Chalk Point site. (Auth.)

1980-05-08

236

Evaluation of mathematical models for characterizing plume behavior from cooling towers. Volume I. Dispersion from single and multiple source natural draft cooling towers. Technical report  

Energy Technology Data Exchange (ETDEWEB)

Fifteen mathematical models for visible plume prediction from natural draft cooling towers are evaluated theoretically and tested with 39 sets of single-tower visible plume field data from three sites. Seven of these models with the capability of treating plumes from multiple towers are further tested with 26 sets of multiple tower data from two sites. The visible plume outlines provided by these data give information on the trajectory of the plume as well as dilution. The model/data comparisons prepared in this study revealed systematic behaviors in the predictions of most models which were able to be traced back to model assumptions. A wide range of predictions was found to occur among the models. No one model performed consistently well for all data sets. Theoretical analysis of the model formulations revealed that models which correctly predict the plume trajectory due to the entrainment mechanism alone will overpredict dilution. The more successful models employ an additional mechanism to provide additional bending without additional mixing. The correctness of any of the additional bending mechanisms remains to be determined. The model/data discrepancies are partly due to model errors and partly due to data measurement errors. The accuracy of the data makes it unlikely for a model to predict better than a factor of 1 1/2-2 in most, perhaps 90%, of all data cases.

Policastro, A.J.; Carhart, R.A.; Ziemer, S.E.; Haake, K.

1980-09-01

237

A simplified modeling of mechanical cooling tower for control and optimization of HVAC systems  

International Nuclear Information System (INIS)

This paper proposes a new, simple, yet accurate mechanical cooling tower model for the purpose of energy conservation and management. On the basis of Merkel's theory and effectiveness-NTU method, the model is developed by energy balance and heat, mass transfer analysis. Commissioning information is then used to identified, only three model parameters by Levenberg-Marquardt method. Compared with the existing models, the proposed model has simple characteristic parameters to be determined and without requiring iterative computation when the operating point changes. The model is validated by real operating data from the cooling towers of a heating, ventilating and air conditioning (HVAC) system of a commercial hotel. The testing results show that the performance of the cooling tower varies from time to time due to different operating conditions and the proposed model is able to reflect these changes by tuning its parameters. With this feature, the proposed model can be simply used and accurately predict the performance of the real-time operating cooling tower.

1399-01-00

238

Validation of cooling-tower plume model at the Philippsburg and Geysers sites  

Energy Technology Data Exchange (ETDEWEB)

New data on visible plumes have become available from Philippsburg (single natural-draft cooling tower, approx. 800 MWe) in West Germany and the Geysers site (single mechanical-draft cooling towers approx. 100 MWe) in northern California, USA, for testing models for cooling tower plume rise. The Philippsburg data were taken under humid conditions in which significant plume thermodynamic effects are expected to occur. The Geysers data were taken under hot and dry ambient conditions (minimizing plume thermodynamics) but with the site in complex terrain. The Philippsburg and Geysers data represent extremes in ambient conditions not generally observed with previous data (Chalk Point, Luenen, and Paradise sites) used for earlier model validation. For Philippsburg, fourteen American models for natural-draft cooling tower plume (NDCT) dispersion have been tested with 16 data cases. All the models tested employ the one-dimensional integral method. The performance of the models at Philippsburg has then been compared with the performance of the same models with 39 field data cases previously assembled form our earlier model validation study. The predictive accuracy of all of the 14 models tested was about the same for the 16 Philippsburg cases as for the earlier 39 cases.

Policastro, A.J.; Wastag, M.; Dunn, W.E.; Carhart, R.

1982-01-01

239

Desinfection of cooling towers and cooling water by UV-treatment on the example of a chemical company; Desinfektion von Kuehltuermen und Kuehlkreislaeufen durch UV-Behandlung am Beispiel eines Chemiebetriebs  

Energy Technology Data Exchange (ETDEWEB)

Using a Belgian adhesives manufacturer as example, it is shown how formation and growth of micro-organisms can adversely affect a modern manufacturing process. The problem lies not with the actual process solution, but in the cooling section. Installation of a suitably-configured UV reactor allowed long-term operation without any problems from micro-organisms. The outcome was a much more stable process at acceptable cost and with significantly lower volumes of solid waste. (orig.)

Peuters, J.; Carbone, J. [Sadepan Chimica NV (Belgium); Daele, D. van (DVD Technology); Dams, S.; Weckenmann, J.; Soerensen, M. [a.c.k. aqua concept GmbH, Karlsruhe (Germany)

2007-07-01

240

Mathematical model of drift deposition from a bifurcated cooling tower plume  

International Nuclear Information System (INIS)

Cooling tower drift deposition modeling has been extended by including centrifugal force induced through plume bifurcation in a crosswind as a mechanism for drift droplet removal from the plume. The model, in its current state of development, is capable of predicting the trajectory of a single droplet from the stage of strong interaction with the vortex field soon after droplet emission at the tower top through the stage of droplet evaporation in an unsaturated atmosphere after droplet breakaway from the plume. The computer program developed from the mathematical formulation has been used to explore the dependency of the droplet trajectory on droplet size, vortex strength, point of droplet emission, drag coefficient, droplet efflux speed, and ambient conditions. A specific application to drift from a mechanical-draft cooling tower (for a wind speed twice the efflux speed, a relative humidity of 70 per cent, and an initial droplet radius of 100 ?m) showed the droplet to follow a helical trajectory within the plume, with breakaway occurring at 2.5 tower diameters downwind and ground impact of the droplet (reduced through evaporation to 55 ?m radius) at 11 tower diameters.

1978-01-01

 
 
 
 
241

Wind tunnel experiments on cooling tower plumes. Pt. 2  

International Nuclear Information System (INIS)

[en] The basic characteristics of plumes issuing into a boundary layer type of cross flow are reported. The flow can be considered as an interaction between two vorticity fields with different length scales and turbulence intensities. The large eddies of the oncoming boundary layer are responsible for the observed sudden changes in the plume direction. The type of structures emanating the tower depends on the instantaneous velocity ratio. Mean velocities and normal velocity gradients are smaller than in the case of uniform cross-flow (Andreopoulos, 1986) and therefore the measured turbulence intensities were lower too. The cross-stream turbulence brings high momentum fluid into the wake region and the velocity defect decays very rapidly. Dilution of the plumes takes place faster in the presence of external turbulence than in the case with uniform cross-flow. The spreading rate is increased dramatically by the external turbulence which causes different effects on the hydrodynamic and thermal fields. (orig.)

1986-01-01

242

Heating with cooling water  

Energy Technology Data Exchange (ETDEWEB)

Experts from Sulzer Infra have undertaken energy-saving measures in a number of buildings belonging to Hoffmann-La Roche, the pharmaceutical concern in Basle (Switzerland). The energy content of water from the river Rhine, which became heated during the cooling of installations, is now being put to good use. The concept for this was elaborated in close cooperation with the energy-saving office and the responsible planning engineer of Hoffroche. (author)

Thoma, E. (Hoffmann-La Roche (F.) and Co., Basel (Switzerland)); Bringman, A. (Sulzer Infra Management Services Ltd., Winterthur (Switzerland))

1994-07-01

243

Effectiveness of 1-bromo-3-chloro-5,5-dimethylhydantoin against Legionella pneumophila in a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are considered to be man-made amplifiers of Legionella spp. Thus, the proper maintenance and choice of biocides is important. The only biocidal measure that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies with 1-bromo-3-chloro-5,5-dimethylhydantoin (Bromicide; Great Lakes Chemical Corporation, West Lafayette, Indiana) (BCD) were conducted on an industrial cooling tower shown to contain Legionella pneumophila. At the concentrations recommended by the manufacturer, neither the density nor the activity of L. pneumophila was affected. At concentrations greater than 2l0 ppm (2.0 ..mu..g/ml) free of residual, BCD was not effective in reducing L. pneumophila to source water concentrations, nor was it effective in reducing the 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl tetrazolium chloride activity of the bacterium in situ. The data indicate that at concentrations up to 2.0 ppm, BCD is not effective in these tower studies.

Fliermans, C.B.; Harvey, R.S.

1984-06-01

244

CEGB research on the effects of fouling of plastic packings on natural draught cooling tower performance  

International Nuclear Information System (INIS)

Plastic film packings were first used in CEGB natural draught cooling towers in 1985. Since then, cooling towers at seven power stations have been repacked using various commercial designs of plastic packing, with generally satisfactory results in economic terms. However, fouling of all the packings has occurred to some extent, ranging from very thin films on the surface of the sheets, which actually enhances performance, to heavy and voluminous formations which severely constrict the inter-sheet passages, causing performance loss and threatening the structural integrity of the whole fill. At CERL, methods have been developed to relate the degree of fouling to the thermal performance loss. This information is enabling accurate calculations to be made of the economics of repacking. Samples of fouled packing from operation towers are tested using the Experimental Cooling Tower at the Central Electricity Research Laboratories at Leatherhead. A systematic investigation is also underway of the changes in pressure drop and mass transfer coefficients which take place as fouling develops, using progressively-fouled packing samples from a purpose-built Packing Fouling Facility located at one of the power stations. The performance data obtained is fed-back into models by which the effect of high fouling loadings on various packings is calculated, enabling packing economic life to be predicted.

1989-01-01

245

Effect of the shape of the tower supports and walls on the performance of a dry-cooling tower subjected to cross winds  

Energy Technology Data Exchange (ETDEWEB)

Cross winds generally reduce the heat rejection rates of natural draft dry-cooling towers. The influence of different tower support geometries and a windbreak wall on the performance of a dry-cooling tower with a horizontal heat exchanger arrangement, during windy periods, is investigated. Based on experimental results, expressions for the tangential and radial pressure loss coefficients for an array of supports in an inclined-flow situation are found. A numerical analysis reveals that the wind effect on the heat rejection rate is strongly dependent on both the shape and the pressure loss coefficients of the supports. Significant reductions in the wind effect on the tower can be achieved under certain conditions.

Du Preez, A.F.; Kroeger, D.G. [Univ. of Stellenbosch (South Africa). Dept. of Mechanical Engineering

1995-04-01

246

Thermoelectrically cooled water trap  

Energy Technology Data Exchange (ETDEWEB)

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

Micheels, Ronald H. (Concord, MA)

2006-02-21

247

Water cooled nuclear reactor  

International Nuclear Information System (INIS)

A description is given of a cooling water intake collector for a nuclear reactor. It includes multiple sub-collectors extending out in a generally parallel manner to each other, each one having a first end and a second one separated along their length, and multiple water outlets for connecting each one to a corresponding pressure tube of the reactor. A first end tube and a second one connect the sub-collector tubes together to their first and second ends respectively. It also includes multiple collector tubes extending transversely by crossing over the sub-collector tubes and separated from each other in the direction of these tubes. Each collector tubes has a water intake for connecting to a water pump and multiple connecting tubes separated over its length and connecting each one to the corresponding sub-collector.

1974-04-29

248

Safety cooling of the 2x1000 MW units of the Paks Nuclear Power Plant by forced-ventilation type cooling towers  

International Nuclear Information System (INIS)

Safety cooling system for the planned 1000 MW units of the Paks NPP is presented. Design aspects are discussed for normal cooling tower operation and for operation of planned cooling-down regime, with three and one cooling line in operation, respectively. (R.P.).

1989-01-01

249

A model for radionuclide transport in the Cooling Water System  

International Nuclear Information System (INIS)

[en] A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA

1992-01-01

250

Light water cooled reactor  

International Nuclear Information System (INIS)

In an emergency condensator for a light water cooled type reactor, a heat transfer pipe is submerged in a pool of an emergency condensator system, a water condensation chamber is disposed at the outside of the pool by way of concrete walls, and a steam chamber is disposed in the water condensation chamber. The emergency condensator can be reduced in the size and maintenance/inspection for the water condensation chamber and the heat transfer pipe can be conducted without withdrawing pool water. Further, the heat transfer pipe is formed as a horizontally extended U-shaped pipe, both legs of the U-shaped pipe are inclined in order not to stagnate condensates in the heat transfer pipe, and a great number of holes are perforated to a support shell to smooth the flow of coolants on the side of the body, to improve heat exchange performance of the heat transfer pipe. Further, the heat transfer pipe is supported by a buffle, the buffle is secured to the support shell and the support shell is secured to a support saddle, to provide a strength sufficient to withstand the own weight of the heat transfer pipe and earthquakes. A bent tube is disposed to the water condensation chamber to discharge incondensible gases stagnated in the water condensation chamber by leading them to the coolant pool in the wet well. (N.H.).

1991-09-25

251

Construction and operation of natural draught cooling towers made of highly acid-resistant concrete; Bau und Betrieb von Naturzugkuehltuermen aus Beton mit erhoehtem Saeurewiderstand  

Energy Technology Data Exchange (ETDEWEB)

In 1999 the construction of the first cooling tower shell using highly acid-resistant concrete started at the RWE power station of Niederaussem. This type of concrete was developed after four years of research to avoid the necessary coating of the inner cooling tower shell due to the discharge of flue gases via cooling tower. The positive experience led RWE Power to build two more cooling towers of this type at the power station of Neurath and even order four more cooling towers for two planned power stations in the west and southwest of Germany. (orig.)

Niepel, A. [RWE Power AG, Kraftwerk Niederaussem, Bergheim (Germany); Huettl, R. [Materialpruefungsanstalt Berlin-Brandenburg GmbH, Berlin (Germany); Kloeker, T.; Meyer, J. [Zerna Ingenieure GmbH, Bochum (Germany); Busch, D.

2007-07-01

252

Effects of discharge recirculation in cooling towers on energy efficiency and visible plume potential of chilling plants  

International Nuclear Information System (INIS)

Due to limited space and/or improper placement of evaporative cooling towers, discharge recirculation likely occurs in practical applications. The air recirculation may adversely affect energy efficiency of the chilling plants and increase the potential of visible plume around the towers. In this study, the amount of recirculation in a counter-flow cooling tower is evaluated by computational fluid dynamics (CFD) simulation tests under different enclosure structures and crosswind conditions. Then the effects of recirculation in cooling towers on energy performance of a chilling plant and plume potential are investigated. The evaluation is conducted on a dynamic simulation platform using the weather data in a typical meteorological year of Hong Kong. Results show that crosswind can enhance recirculation in cooling towers under lower air flow rate conditions. The recirculation ratio can reach up to 15%. Results also reveal that air recirculation in cooling towers could result in the increase of overall chilling plant energy consumption by over 1.5%. The recirculation also results in significant increase of plume occurrence frequency, particularly in spring season. - Highlights: ? Discharge recirculation in a cooling tower is evaluated by CFD modeling. ? The recirculation ratio can reach up to 15%. ? The recirculation can increase the overall chilling plant energy consumption by over 1.5%. ? The recirculation can significantly increase the plume occurrence frequency.

2012-01-01

253

Water cooled nuclear reactor  

International Nuclear Information System (INIS)

The pressure vessel is divided by a transverse separating wall above the core into a high pressure and a low pressure plenum chamber. The cooling water flows vertically from below upwards through the core, so that hydraulic lifting forces act on the core. To compensate for these forces a core holding down device, consisting of a pressure piston system is provided. The piston surface is at the pressure of the upper high pressure plenum chamber, while the piston rod acts through the separating wall inside a sealing cylinder on the fuel elements in the core. (orig.)

1980-01-01

254

Water cooled nuclear reactor  

International Nuclear Information System (INIS)

The pressure vessel is divided by a transverse separating wall above the core into a high pressure and a low pressure plenum chamber. The cooling water flows vertically from below upwards through the core, so that hydraulic lifting forces act on the core. To compensate for these forces a core holding down device, consisting of a pressure piston system is provided. The piston surface is at the pressure of the upper high pressure plenum chamber, while the piston rod acts through the separating wall inside a sealing cylinder on the fuel elements in the core. (DG)

1979-01-01

255

Statistical study on meteorological effects due to the cooling tower of Goesgen  

International Nuclear Information System (INIS)

A specific statistical method has been developed to study the effects of a cooling tower plume on local meteorological parameters. It is based on the comparison of hourly meteorological measurements, made simultaneously at stations near the cooling tower and in other stations unaffected by the plume. To study the reduction of sunshine duration due to the shadowing of the plume, measurements from two stations situated within a radius of about 1 km eastward and westward of the power station are compared. In clear weather, only one of these two stations usually lays in the shadow of the plume. Statistical treatment of differences detected in temperature, humidity, precipitation, sunshine duration and solar radiation shows systematic results, observed mainly when the power station is active. It appears that the effects on sunshine duration are the most important, followed by the influence on solar radiation. Differences in temperature and humidity are also detectable. No relevant influences have been found on precipitation.

1989-01-01

256

Proposal for the award of a contract for the construction of cooling-tower structures  

CERN Multimedia

This document concerns the award of a contract for the construction of reinforced-concrete cooling-tower structures at LHC Point 1. Following a market survey carried out among 79 firms in 17 Member States, a call for tenders (IT-2710/ST/LHC) was sent on 13 August 1999 to eight firms and two consortia, both consisting of three firms, in eight Member States. By the closing date, CERN had received four tenders. The Finance Committee is invited to agree to the negotiation of a contract for the construction of reinforced-concrete cooling towers at LHC Point 1 with the consortium PAT (AT), BARESEL (DE) and ZSCHOKKE LOCHER (CH), the lowest bidder complying with the specification, for an amount of 3 393 493 Swiss francs, not subject to revision. The consortium has indicated the following distribution by country of the supply covered by this adjudication proposal: BE-60%, AT-18%, CH-11% and DE-11%.

1999-01-01

257

Tracking of smokestack and cooling tower plumes using wind measurements at different levels  

International Nuclear Information System (INIS)

Relationships between cooling tower and smokestack plumes at the Bowen Electric Generating Plant in northwestern Georgia and wind direction measurements at levels from the surface at 850 mb (approx. 1.5 km) are examined. The wind measurements play an important role in estimating plume directions which in turn are utilized to establish control and target (upwind and downwind) areas for a study of plant-induced precipitation modification. Fifty-two plume observations were made during a three week period in December 1979. Results indicate that a windset (4.5 km from the plant) mounted at a level approximating that of the cooling tower plume is a better predictor of plume direction than surface windsets (1.0 km from the plant) or 850 mb level winds. However, an apparent topographical influence on the wind direction measurements at the plume-level windset site somewhat limits its plume tracking capability, at least for ambient winds from the SW quadrant

1980-01-01

258

Natural-draught wet-type cooling tower of the Philippsburg 1 nuclear power plant  

International Nuclear Information System (INIS)

[en] In spring 1980, comprehensive field measurements were performed on the natural-draught wet type, cooling tower of Philippsburg I nuclear power plant. Performance in service and emission of cooling tower, condition of ambient atmosphere and spread of plume were studied in seven subprojects. The report on hand contains the results of the 8th subproject within which plume spreading was calculated by means of mathematical models. Efforts were made to win the participation of as large as circle of scientists as possible in order to obtain an overview on the efficiencies of the existing models. The size of visible plumes were calculated by means of emission data and ambient data and were compared with those dimensions resulting from photograph. The models and the results are described in individual reports. Results were summarized for B models. Complete data on the 16'Philippsburg incidents' are contained in the annex to the program report. (orig./HP)

1984-01-01

259

Flue gas discharge through cooling towers. Measurements at the pilot power plant Voelklingen of the Saarbergwerke AG  

Energy Technology Data Exchange (ETDEWEB)

The flue gases are cooled in wet desulphurization plants. This enables the combined discharge of the cleaned gases mixed with the air from the cooling tower through natural draught-wet cooling towers. The favourable rising behaviour and the compact coherence of the cooling tower vapour are employed to spread the flue gases loaded with the remaining amounts of noxious matter. In power station units which are not equipped with natural draught-wet cooling towers the cleaned flue gases have to be heated up and discharged through high chimneys. - So far, the only plant that has realized the combined discharge of flue gases and cooling tower vapour is the Pilot Power Plant Voelklingen of the Saarbergwerke AG. Two extensive measuring campaigns run by the Rheinisch Westfaelisches Elektrizitaetswerk AG and by the Saarbergwerke AG. proved the variant of the cooling tower to be a favourble alternative to the variant of the chimneys which have been used so far with regard to immissions. During the taking of the measurements and extensive picture of the operational behaviour of the plant, the condition of the emission and their spreading into the atmosphere was gained. (orig.).

Leidinger, B.; Natusch, K.; Scholl, G.

1985-10-01

260

Three-dimensional calculations of plumes in the near field of a cooling tower  

International Nuclear Information System (INIS)

This paper shows a comparison between 3D computation and some results of scale models experiments in the near field of a cooling tower. We compare the velocity and temperature fields and we found a rather good agreement with the measurements. The rough description of the shell in the computation gives rise to a pressure field which has not the same intensity as the measured field.

1980-09-18

 
 
 
 
261

Natural-draught cooling tower of the Philippsburg-1 reactor. Naturzug-Nasskuehlturm des Kernkraftwerkes Philippsburg (Block I)  

Energy Technology Data Exchange (ETDEWEB)

In spring 1980 a comprehensive research programm was carried out on the natural-draught cooling tower of the Philippsburg-1 reactor. The study was meant to synchronously acquire all parameters necessary for the evaluation of plant operation and cooling tower emissions. The study is subdivided into 8 sub-projects. Parts 1 to 7 that are included in this progress-of-work report describe experimental work and discuss the results. A critical analysis of measuring results proves that the values for operational behaviour and cooling tower emissions were duly anticipated. Even a very critical judgment of the results can exclude direct or indirect hazards for humans, animals and plants owing to cooling tower emissions. Sub-project 8 compares results from diffusion calculations (24 models) to results gained from experiments. The results of sub-project 8 will be published in a progress report to come.

Ernst, G.; Wurz, D.

1983-01-01

262

Nonlinear dynamic behaviour of R.C. cooling towers in earthquake excitations  

Energy Technology Data Exchange (ETDEWEB)

Wind has been the primary load in the design of natural draft concrete cooling towers. The effect of earthquake load has previously been considered as insignificant. In most of the literature, the shell is considered as the main part of the structure and therefore, the focus of many investigations. Considering the site of the cooling tower, earthquake load may overcome wind load in some parts of the structure. However, it appears that under earthquake loading, the damages in columns may be much more than those in shell and foundation. This paper researched nonlinear dynamic behavior of concrete cooling towers in earthquakes using the ABAQUS software package. The dynamic step by step integration method was used for analysis. Both of the geometric and material nonlinearities were considered. The concrete damaged plasticity model was used for the concrete behavior. The soil was replaced by equivalent springs for soil-structure interaction. Displacements, locations of damages and values were also obtained. It was concluded that the major part of damages was in columns and energy dissipation was low. In addition, the deformability or ductility factor that was used in design was not satisfactory. 13 refs., 3 tabs., 11 figs.

Sabouri-Ghomi, S.; Saadati, B. [K.N. Toosi Univ., Tehran (Iran, Islamic Republic of). Faculty of Civil Engineering

2007-07-01

263

Measures to ensure the quality against atmospheric stresses when constructing a natural draught cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The damage occurring on the concrete shells of natural draught cooling towers due to stresses from atmospheric effects have resulted in special measures to provide and ensure the quality of new cooling towers. These consist of the following: - matching the composition of the concrete to the different stresses in the various areas of the concrete shell, - a double protective coating with impregnation on the inner shell and a single protective coating of the outer shell. The impregnation prevents or delays the growth of micro-organisms. - by carrying out building work matching the timing of the production of the concrete at site, using a Doka shell and additional concrete inspection and quality control, - the careful construction of the concrete shell reducing the annular gaps, the vertical joints and the anchors. This can be done by the above-mentioned Doka shell. This report gives details of construction and of the many quality controls. The extra expense for quality assurance is given as 4 to 6% for this natural draught cooling tower (diameter at base 90 m, height 118 m).

Boesch, H.J.

1983-01-01

264

Light water cooled reactors  

International Nuclear Information System (INIS)

Purpose: To improve inherent reactor safety without impairing the economical advantage of a light water cooled reactor adapted to control the power by the aqueous boric acid concentration in primary coolant circuits. Constitution: A water feed tank for an emergency feedwater system is disposed at a position above a reactor pressure vessel in communication with the inside thereof and a pump for sucking a portion of a primary coolant or aqueous boric acid from the suction port for the detection of low water level is disposed near the pressure vessel. A control valve is disposed to the midway of an emergency feedwater system for opening the pipeway in a case if the pump discharge pressure is reduced. Water is automatically fed by the actuation of the control valve to maintain the core fluidizing state. Economical problems during development can be solved by substantially sharing the inner volume of the pressure vessel by the feedwater tank. It is possible to reduce the restriction in the case of increasing the allowable spontaneous leaving time upon occurrence of accidents and increase the inherent safety of the foolproof system. (Kamimura, M.)

1985-11-07

265

Localized corrosion monitoring in cooling water systems  

Energy Technology Data Exchange (ETDEWEB)

Localized corrosion in plant operating conditions is often overlooked, partly due to the fact that none of the techniques commonly used today can provide realistic and effective monitoring of localized corrosion. Recent introduction and development of two new techniques (i.e., electrochemical noise and differential flow cell method) has renewed the interest in on-line localized corrosion monitoring in cooling water systems. Results on using the two techniques to monitor cooling water system localized corrosion in both bench-top and pilot plant scale (i.e., pilot cooling tower) tests are presented. The results show that the differential flow cell technique can be used to determine mild steel propagating localized corrosion rates accurately and reliably. On the other hand, electrochemical noise measurements alone did not provide accurate quantitative determination of corrosion rates because the anodic corrosion reaction and cathodic corrosion reaction did not occur at well separated sites and time in cooling water environments. Only very rough qualitative information regarding corrosion rate can be extracted from electrochemical noise measurement data. Spectral analysis of the potential noise data may give misleading information on the type of corrosion occurring. On the other hand, performing spectral analysis of current noise data may provide useful information on the type of corrosion (e.g., uniform or localized).

Yang, B. [Nalco Chemical Co., Naperville, IL (United States)

1995-12-01

266

What comes out of the Goesgen cooling tower  

International Nuclear Information System (INIS)

The results of a poll of 500 people (118 French-speaking Swiss, and 382 German-speaking Swiss) to find out what they think is discharged into the atmosphere by the Goesgen reactor, are discussed. It seems that, in general, the French-speaking Swiss (Romands) think that there is more pollution in the water vapor than do the German-speaking Swiss. (G.T.H.)

1983-02-19

267

Optimal Environmental Performance of Water-cooled Chiller System with All Variable Speed Configurations  

Science.gov (United States)

This study investigates how the environmental performance of water-cooled chiller systems can be optimized by applying load-based speed control to all the system components. New chiller and cooling tower models were developed using a transient systems simulation program called TRNSYS 15 in order to assess the electricity and water consumption of a chiller plant operating for a building cooling load profile. The chiller model was calibrated using manufacturer's performance data and used to analyze the coefficient of performance when the design and control of chiller components are changed. The NTU-effectiveness approach was used for the cooling tower model to consider the heat transfer effectiveness at various air-to-water flow ratios and to identify the makeup water rate. Applying load-based speed control to the cooling tower fans and pumps could save an annual plant operating cost by around 15% relative to an equivalent system with constant speed configurations.

Yu, Fu Wing; Chan, Kwok Tai

268

Investigation of Microbial Respirometry for Monitoring Natural Sulfide Abatement in Geothermal Cooling Tower Basins  

Energy Technology Data Exchange (ETDEWEB)

Geothermal plant operators are interested in investigating the ability of micro-organisms found in the cooling tower basin to metabolize and cycle sulfide to less toxic sulfur compounds. If the growth or activity of the organisms participating in sulfur-oxidation could be selectively enhanced, then hydrogen sulfide could be naturally abated in the cooling basin, substantially reducing the costs associated with the chemicals used for abatement. The use of respirometry has been proposed as a technique for monitoring the response of the microbial populations found in geothermal cooling towers to various conditions, including the addition of nutrients such as nitrogen and phosphorus. Respiro-metry is a manometric measurement of dissolved gases that are in equilibrium in a con-fined sample volume. Since microbes expire varying amounts of carbon dioxide or oxygen as they metabolize nutrients, this technique can be used to evaluate their activities in process streams. This report describes a series of experiments designed to determine the suitability of respirometry for tracking microbial activity for evaluating and enhancing natural abatement processes in geothermal cooling basins.

Peter A. Pryfogle

2005-09-01

269

Cooling of feed water tubes  

International Nuclear Information System (INIS)

Describes a design of the feed water tubes. The new design has a second air coolant channel placed near the inner side of the biological shield. By this arrangement the cooling of the feed water tube is improved.

1992-02-04

270

Evaluation of mathematical models for natural-draft cooling-tower plume dispersion  

Energy Technology Data Exchange (ETDEWEB)

This paper provides an evaluation of the theory and performance of 16 models commonly used for the prediction of cooling-tower plume rise from natural- draft cooling towers. The performance of the models is determined through model/data comparisons with: (a) field data encompassing visible plume outlines obtained through plume photographs and (b) single-phase laboratory data on plume trajectories and dilutions. The field data used included 39 data sets from single tower NDCT models and two multiple-tower NDCT models provided notably superior predictions than the remaining models. These models represent the current state of the art. For field-data applications, they can predict within a factor of two for visible plume rise and a factor of 2 1/2 for visible plume length, but only for 50% of the cases tested. Our review of model assumptions, which included several sensitivity studies, revealed several problem areas which remain unresolved. First, no model is able to achieve correct simultaneous predictions of plume trajectory and dilution. Second, the common treatment of plume thermodynamics affects plume dynamics too strongly when ambient profiles favor plume conditional and/or ambient latent instability. Third, no model correctly represents the rapid bending and additional dilution exhibited by the data under high wind conditions. Fourth, the plume merging logic is oversimplified and does not account for the effects of wind direction on plume dispersion. Fifth, the treatment of the diffusion phase is not developed from data taken at the large heights these plumes attain. The field and laboratory data base are sufficiently strong to support improvement in model theory and performance.

Carhart, R.A. (Univ. of Illinois, Chicago); Policastro, A.J.; Ziemer, S.

1982-01-01

271

A comparison of economy and technology between air-cooled condensers with natural-draft cooling towers working according to the direct and indirect system  

International Nuclear Information System (INIS)

The direct system of air cooling, the air cooled condenser, being already implemented in a 365 MW turbine unit, the question has again to be put which advantages this system has to offer in comparison with the indirect system, and whether in the case of larger units, e.g. with natural draft cooling towers, the results to be expected are different from those obtained in smaller plants with forced cooling. (orig.)

1976-05-21

272

The change in characteristics of water during it's passage through closed circuit cooling water system  

International Nuclear Information System (INIS)

Power stations employing closed circuit cooling water system for dissipating their waste heat often face the problem of scaling on the condenser tube surfaces, despite the provision of low concentration factor (C.F). values. In order to understand the chemical changes taking place in water, when it passes through a wet cooling tower in operation, raw water sample from a thermal power station was exposed to identical conditions in laboratory. The raw water sample exposed to atmosphere, and aerated continuously, was maintained at a temperature of 40±1 degC. The chemical characteristics, such as pH, conductivity, alkalinity, silica, hardness, chloride, sodium, etc were followed along with the changing C.F. values. This paper explains the chemical changes in the water during its passage through the cooling tower operation processes in the light of the results obtained and the practical implications of these findings in real system. (author)

2000-01-01

273

Measures for noise pollution abatement in existing cooling tower systems; Massnahmen zur Geraeuschminderung an bestehenden Kuehlturmanlagen  

Energy Technology Data Exchange (ETDEWEB)

The operator`s order discussed by the paper was for planning and performance of backfitting measures for noise pollution abatement in an existing cooling tower system equipped with sound attenuation devices. Although the existing plant was operating in compliance with the legal noise emission limits, residents of neighbouring dwellings had been complaining about noise pollution. (orig./CB) [Deutsch] Die Aufgabe, eine nachtraegliche Massnahme zur Laermminderung an einer bestehenden, mit Schalldaempfern ausgeruesteten Anlage zu planen und durchzufuehren, wurde vom Betreiber einer Rueckkuehlanlage gestellt. Der vom Gesetzgeber definierte Grenzwert fuer den Nachtbetrieb wurde mit der bestehenden Anlage zwar erreicht, doch die Anwohner fuehlten eine Belaestigung durch den Anlagenbetrieb. (orig./GL)

Niessen, R. [Sulzer-Escher Wyss GmbH, Lindau (Germany)

1998-09-01

274

A petrolatum based system for control of external corrosion in, on and around cooling towers  

Energy Technology Data Exchange (ETDEWEB)

While it is true that the initial cost of a petroleum based system may be slightly higher than that of paint, this article maintains that the cost can be amortized over a 12 or 15-year period, or in some cases even longer. In service maintenance costs on a square foot per year basis, compared to all other alternatives are minimal. Petrolatum systems for external corrosion control on and around cooling towers have been effective service for over fifteen years, in diversified industrial environments that include oil refineries, chemical process plants, power utilities, hospital and university complexes and steel mills.

Berry, M.A.; Steely, C.N.

1986-01-01

275

Reinforced concrete corrosion: Application of Bayesian networks to the risk management of a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Degradation modelling of concrete structures uses uncertain variables and leads, using reliability assessment, to time dependant evolution of failure probabilities. However, only few data are generally available to feed models leading to two types of uncertainties: an intrinsic one depending on the modelled phenomena and one related to the precision of the measurement. Each new data available is a piece of information which allows to update the initial prediction. In this article, an example of updating process, based on a Bayesian network, is presented and applied on the corrosion risk of a cooling tower. (authors)

Capra, B.; Le Drogo, J.; Wolff, V. [OXAND S.A., 36 bis avenue F. Roosevelt, 77210 Avon (France)

2006-07-01

276

Influence of the cooling circulation water on the efficiency of a thermonuclear plant  

Energy Technology Data Exchange (ETDEWEB)

In the present study, the feasibility of intercalating two cooling towers in the present circulation water system used at Almaraz Nuclear Power Plant, located at Campo Aranuelo district (SW Spain), has been technically evaluated in order to increase the efficiency of the thermodynamic cycle used at present. Thus, the working cycle has been analyzed, the power produced by the turbines being calculated as a function of the cooling circulation water temperature. Next, two natural convection counterflow cooling towers have been calculated in order to be installed in parallel with the present cooling system (Lake Arrocampo). The power obtained in the turbines provided with the new system has been estimated. Finally, a system combining both the cooling towers and the Lake Arrocampo has been proposed, the increment in power using one system or the other according to the weather conditions being calculated.

Ganan, J. [Department of Energy and Chemical Engineering, University of Extremadura, Avda. de Elvas, s/n, Badajoz 06071 (Spain); Rahman Al-Kassir, A. [Department of Energy and Chemical Engineering, University of Extremadura, Avda. de Elvas, s/n, Badajoz 06071 (Spain)]. E-mail: aawf@unex.es; Gonzalez, J.F. [Department of Energy and Chemical Engineering, University of Extremadura, Avda. de Elvas, s/n, Badajoz 06071 (Spain); Macias, A. [Department of Electronics and Electromechanical Engineering, University of Extremadura, Avda. de Elvas, s/n, Badajoz 06071 (Spain); Diaz, M.A. [Department of Electronics and Electromechanical Engineering, University of Extremadura, Avda. de Elvas, s/n, Badajoz 06071 (Spain)

2005-03-01

277

Influence of the cooling circulation water on the efficiency of a thermonuclear plant  

International Nuclear Information System (INIS)

In the present study, the feasibility of intercalating two cooling towers in the present circulation water system used at Almaraz Nuclear Power Plant, located at Campo Aranuelo district (SW Spain), has been technically evaluated in order to increase the efficiency of the thermodynamic cycle used at present. Thus, the working cycle has been analyzed, the power produced by the turbines being calculated as a function of the cooling circulation water temperature. Next, two natural convection counterflow cooling towers have been calculated in order to be installed in parallel with the present cooling system (Lake Arrocampo). The power obtained in the turbines provided with the new system has been estimated. Finally, a system combining both the cooling towers and the Lake Arrocampo has been proposed, the increment in power using one system or the other according to the weather conditions being calculated

2005-01-01

278

Calculation and visual displaying of the water chemistry conditions in return cooling systems at thermal power stations  

Science.gov (United States)

Matters concerned with treatment of cooling water at thermal power stations are addressed. Problems arising during operation of return cooling systems equipped with cooling towers are analyzed. The software used for monitoring, control, and indication of the hydraulic and water chemistry operating conditions of the circulation system at the Yaivinsk district power station is considered.

Ochkov, V. F.; Orlov, K. A.; Ivanov, E. N.; Makushin, A. A.

2013-07-01

279

Convection towers  

Energy Technology Data Exchange (ETDEWEB)

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Prueitt, Melvin L. (Los Alamos, NM)

1996-01-01

280

Convection towers  

Energy Technology Data Exchange (ETDEWEB)

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Prueitt, Melvin L. (Los Alamos, NM)

1995-01-01

 
 
 
 
281

Emission of asbestos fibres from natural-draught cooling towers. Pt. 1 and 2. Part 1: Asbestos determined in plume samples from two natural-draught, wet cooling towers. Pt. 2: Behaviour of wet cooling tower internal structures made of asbestos cement. Emission von Asbestfasern aus Naturzugnasskuehltuermen. T. 1 und 2. Teil 1: Asbestgehalt in Schwadenproben aus zwei Naturzug-Nasskuehltuermen. Teil 2: Verhalten von Asbestzementeinbauten in Nasskuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

Sampling for the studies reported has been done in a relatively new nuclear power plant with natural-draught, wet cooling tower, and in an older, brown-coal fired power plant with the same type of cooling towers, both towers equipped with internal structures made of asbestos cement. Samples have been taken from the plumes, air in the environment, cooling water receiving tank, make-up water. The samples have been primarily examined for their content of asbestos fibres. The results show that relatively few asbestos is found in the environmental air and in the cooling water receiving tank. Putting it continuously, it can be said that the cooling water entrains only little amounts of the asbestos of the internal structures. The plume samples indicate emission of some thousand asbestos fibres per m/sup 3/, or less than 1 ng. Taking into account one sample exhibiting an extremely high amount of asbestos, the average emission of asbestos fibres with the plumes is 10/sup 6/ fibres per m/sup 3/, or 100 ng/m/sup 3/ of plume. The maximum air pollution thus calculated in accordance with TA Luft (Clean Air Technical Directive), for the less favourable weather conditions at a hight of 2 m above ground, is 10 fibres per one m/sup 3/ of air; including the extreme data of the single sample mentioned above, the result is some thousand fibres per m/sup 3/. The data are far below the TRK data (Technical guiding data for maximum concentration at the place of work), which state a maximum of 10/sup 6/ fibres per m/sup 3/.

Ernst, G.; Althaus, E.; Karotke, E.; Grimm, K.; Heumann, H.G.; Rueckert, G.

1985-01-01

282

Epidemic dangers on account of the operation of cooling towers and the heating up of rivers  

International Nuclear Information System (INIS)

For some time fear has been growing amongst the population that through a temperature increase in waters as a result of cooling water discharges there may be an increase in pathogenic agents, especially in typhoid bacteria. After the conclusions brought about by personal, extensive examinations in still and running waters burdened with cooling water as well as by a test plant supplied with cooling water, neither an increase in the colony numerical values exceeding 4 digit numbers nor an increase in Salmonellae or the typhoid bacteria belonging to this group, could be determined. (orig.)

1976-01-01

283

Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants  

Energy Technology Data Exchange (ETDEWEB)

This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

Ken Mortensen

2011-12-31

284

Circulating water subsystem design description: 4 x 350 MW(t) Modular HTGR [High-Temperature Gas-Cooled Reactor] Plant  

Energy Technology Data Exchange (ETDEWEB)

The Circulating Water System is a subsystem within the Heat Rejection Group (HRG). The Circulating Water System consists of two independent loops to remove waste heat from the turbine building closed cooling water system and from the condensers associated with each turbine generator set. In normal plant operation circulating water is pumped from the cooling tower basin through the condensers and heat exchangers and back to the cooling tower where the waste heat is released to the atmosphere via mechanical draft cooling towers. The system consists of two flow paths with two half-size, vertical pumps associated with each path.

NONE

1986-06-01

285

The effect of the heat exchanger arrangement and wind-break walls on the performance of natural draft dry-cooling towers subjected to cross-winds  

Energy Technology Data Exchange (ETDEWEB)

In most full scale dry-cooling towers rectangular heat exchanger bundles are arranged either vertically around the circumference of the tower or horizontally in the inlet cross-section of the tower. A numerical procedure is used in the present paper to investigate the influence of the particular arrangement on the performance of a tower in windy conditions with the results being verified by full scale and experimental measurements. Practical suggestions concerning the arrangement of the heat exchangers and wind-break walls are made which may lead to significant reductions in the adverse effect of cross-winds on the performance of dry-cooling towers

Du Preez, A.F; Kroeger, D.G [Department of Mechanical Engineering, University of Stellenbosch, Stellenbosch (South Africa)

1995-12-01

286

Experimental energy performance of open cooling towers used under low and variable approach conditions for indirect evaporative cooling in buildings  

Energy Technology Data Exchange (ETDEWEB)

The success of chilled ceilings and displacement ventilation systems as a means of sensible cooling in buildings has prompted a review of evaporative cooling technology as an effective means of generating the required cooling water. When such cooling water is generated at low approach conditions (2-5 K), at the higher temperatures required in these systems (14-18{sup o}C), very high levels of availability result. In many north western European locations the levels of availability are such that the prospect of supplanting rather than simply supplementing the refrigeration system, for sensible cooling purposes, arises. The viability of the technique, however, largely depends on achieving low approach conditions, at acceptable levels of energy performance. Hence the need to investigate the energy performance of the process. This paper presents the results of recent experimental research into: i) the achievement of low approach conditions in an evaporative cooling test rig; and ii) the energy performance of this test rig when generating cooling water, indirectly, at the temperatures required for chilled ceilings. Energy performance is presented for a range of specific conditions and typical annual efficiencies of cooling water generation are determined. Results are compared with typical energy efficiencies of conventional, vapour compression based, refrigeration systems. A significant potential for improved annual energy performance, is shown. (Author)

Costelloe, B. [Dublin Inst. of Technology (Ireland). Dept. of Building Services Engineering; Finn, D. [University College, Dublin (Ireland). Dept. of Mechanical Engineering

2003-10-01

287

Convection towers  

Energy Technology Data Exchange (ETDEWEB)

Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode.

Prueitt, Melvin L. (Los Alamos, NM)

1994-01-01

288

Lawrence Livermore National Laboratory (LLNL) Experimental Test Site (Site 300) Salinity Evaluation and Minimization Plan for Cooling Towers and Mechanical Equipment Discharges  

Energy Technology Data Exchange (ETDEWEB)

This document was created to comply with the Central Valley Regional Water Quality Control Board (CVRWQCB) Waste Discharge Requirement (Order No. 98-148). This order established new requirements to assess the effect of and effort required to reduce salts in process water discharged to the subsurface. This includes the review of technical, operational, and management options available to reduce total dissolved solids (TDS) concentrations in cooling tower and mechanical equipment water discharges at Lawrence Livermore National Laboratory's (LLNL's) Experimental Test Site (Site 300) facility. It was observed that for the six cooling towers currently in operation, the total volume of groundwater used as make up water is about 27 gallons per minute and the discharge to the subsurface via percolation pits is 13 gallons per minute. The extracted groundwater has a TDS concentration of 700 mg/L. The cooling tower discharge concentrations range from 700 to 1,400 mg/L. There is also a small volume of mechanical equipment effluent being discharged to percolation pits, with a TDS range from 400 to 3,300 mg/L. The cooling towers and mechanical equipment are maintained and operated in a satisfactory manner. No major leaks were identified. Currently, there are no re-use options being employed. Several approaches known to reduce the blow down flow rate and/or TDS concentration being discharged to the percolation pits and septic systems were reviewed for technical feasibility and cost efficiency. These options range from efforts as simple as eliminating leaks to implementing advanced and innovative treatment methods. The various options considered, and their anticipated effect on water consumption, discharge volumes, and reduced concentrations are listed and compared in this report. Based on the assessment, it was recommended that there is enough variability in equipment usage, chemistry, flow rate, and discharge configurations that each discharge location at Site 300 should be considered separately when deciding on an approach for reducing the salt discharge to the subsurface. The smaller units may justify moderate changes to equipment, and may benefit from increased cleaning frequencies, more accurate and suitable chemical treatment, and sources of make up water and discharge re-use. The larger cooling towers would be more suitable for automated systems where they don't already exist, re-circulation and treatment of blow down water, and enhanced chemical dosing strategies. It may be more technically feasible and cost efficient for the smaller cooling towers to be replaced by closed loop dry coolers or hybrid towers. There are several potential steps that could be taken at each location to reduce the TDS concentration and/or water use. These include: sump water filtration, minimization of drift, accurate chemical dosing, and use of scale and corrosion coupons for chemical calibration. The implementation of some of these options could be achieved by a step-wise approach taken at two representative facilities. Once viable prototype systems have been proven in the field, systematic implementation should proceed for the remaining systems, with cost, desired reduction, and general feasibility taken into consideration for such systems.

Daily III, W D

2010-02-24

289

Fill fouling experiences on both mechanical and natural draft towers  

International Nuclear Information System (INIS)

Fouling of the film fill in cooling towers is becoming an increasingly serious problem in the Utility Industry. This paper discusses Florida Power Corporation's experience with fouling of film type fill in two mechanical draft and two natural draft towers. The two mechanical draft towers were placed in service as helper towers at the Anclote Plant in 1981. The two natural draft towers went into service at the Crystal River North Site in 1982 and 1984 for closed cycle cooling. All the towers are on salt water systems.

1992-01-01

290

Cleaning device for cooling elements of a dry cooling tower consisting of finned tubes  

International Nuclear Information System (INIS)

A nozzle housing is set on to the cooling elements which is equipped with intermediate walls as air guides. A compressed air connection and a suction air connection can be moved vertically in the nozzle housing by a transport spindle. There is a measuring device for dust loading between the two connections. (RW)

1980-01-01

291

Development of wet-bulb-temperatures in Germany with special regard to conventional thermal power plants using wet cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Wet-bulb-temperature (WBT) defines the cooling distance of cooling water in wet cooling towers (or wet honeycomb radiators) at water-cooled power plants. Thus, the development of WBT in the 21{sup st} century under different scenarios of future climate change is highly relevant for the electricity production sector and is examined in this study for Germany. We use high-resolution simulated data from the regional climate model REMO. As WBT is no direct model output, it is calculated using dry-bulb-temperature (DBT), relative humidity and surface air pressure using two alternative methods. The iterative method provides better results for validation. The computed WBT is quite close to the observations. It reveals a statistically significant exponential increase until 2100 ranging from 1.6 C to 2.4 C in the B1 scenario and from 2.6 C to 3.4 C in the A2-scenario. Furthermore the study indicates that changes of the DBT will be the decisive factor for the WBT-increase in the 21{sup st} century. Significant differences in the increase of extreme heat events between a region in northern and one in southwestern Germany are highlighted by a threshold analysis. The increase of hourly extreme values in southwestern Germany is about 30% higher than in the north. A detected west-east gradient is probably related to the North Atlantic Oscillation and a general increase in westerly situations over Germany. The discrepancies between B1 and A2 scenario are striking and highlight the impact of different levels of global greenhouse gas emissions on regional climate. (orig.)

Aich, Valentin; Paeth, Heiko [Univ. of Wuerzburg (Germany). Inst. of Geography; Strauch, Ulrike [European Institute for Energy Research, Karlsruhe (Germany); Sieck, Kevin; Jacob, Daniela [Max-Planck-Institute for Meteorology, Hamburg (Germany); Leyens, Dirk [EnBW Energie Baden-Wuerttemberg AG, Karlsruhe (Germany)

2011-12-15

292

VGB recommendation for winter operation of wet cooling towers for power plants. VGB-Empfehlung ueber den Winterbetrieb von Kraftwerks-Nasskuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

This VGB Recommendation is a compilation of experience and information. It describes the effects of ice formation and winter operation on the components of natural-draught cooling towers and forced-ventilation cooling towers and proposes constructional and operational measures to prevent ice formation. (DG).

1988-01-01

293

Performance of a hotel chilled water plant with cool storage  

Energy Technology Data Exchange (ETDEWEB)

A comprehensive monitoring suite was installed at a large convention hotel located in San Francisco, CA. The instrumentation was used for a research project to evaluate the effectiveness of electricity price based controls that automate response to real time pricing and to characterize the operation and performance of the hotel's chilled water plant that included a newly installed ice cool storage system. The hotel operates under real-time electricity rates. To date, over four years of data have been collected. Data included electricity use for all chillers, secondary coolant, chilled water, condenser pumps, and the cooling tower fans. Thermal flow data were also collected for the storage system, ice chiller, direct cooling chillers, and chilled water load loops. This paper (1) describes the chilled water plant, (2) defines the performance measurement objectives for the project, (3) discusses operational experience with the plant, focusing on the cool storage system, (4) analyzes chilled water plant and cool storage system operation by examining the charge/discharge heat flow data, and (5) evaluates how well the plant as a whole and the cool storage system specifically met cooling loads of the facility, and how this affected their use.

Gillespie, K.L.; Blanc, S.L.; Parker, S.

1999-07-01

294

A mechanistic approach to the development of chemical solutions for fouling of cooling tower film fills  

Energy Technology Data Exchange (ETDEWEB)

Since the 1980`s reported incidents of cooling tower film fill fouling have continually increased and many utilities have sought chemical treatment solution for their fouling problems. Specialty chemical companies have been called upon to research the problems and to provide programs and products that address this pressing issue. The process of surface fouling of high efficiency film fill is a complex problem due to the multiple components involved in the fouling. An in depth understanding of the problem is necessary to determine effective treatment approaches. This study defines the mechanisms of film fill fouling by examination of microorganisms, silt particles and inorganic minerals in the fouling process. The investigation of chemical treatment approaches for the effective control of fouling based on the fouling mechanisms also are discussed.

Gill, J.S.; Yorke, M.A.; Donlan, R.M.; Gibbon, D.L.; McClung, B. [Calgon Corp., Pittsburgh, PA (United States)

1995-02-01

295

Fuzzy Logic Application for Optimization of the Cooling Towers Control System  

CERN Document Server

The control system for the SPS-BA6 cooling towers station is considered in order to introduce the concept of a multivariable process. Multivariable control means the maintenace of several controlled variables at independent set points. In a single-variable system, to keep the single process variables within their critical values is considered a rather simple operation. In a complex multivariable system, the determination of the optimal operation point results in a combination of all set values of the variables. Control of a multivariable system requires therefore a more complex analysis. As the solution based on a mathematical model of the process is far beyond acceptable complexity, most mathematical models involve extensive simplifications and linearizations to optimize the resulting controllers. In this report the author will demonstrate how fuzzy logic might provide elegant and efficient solutions in the design of multivariable control based on experimental results rather than on mathematical models.

Blanc, D

2000-01-01

296

Economic evaluation of the transfer internals of evaporation cooling towers with natural draught  

Energy Technology Data Exchange (ETDEWEB)

For evaluating the economic value of heat transfer internals of a wet cooling tower (at given operating condition), the total expenditure for the optimally laid-out is decisive, related to the heat removed to the ambient atmosphere. This specific expenditure for heat removal depends on the characteristic values of the internals for the heat transfer, on the pressure drop and on the price. It is not permissible to judge the internals from one characteristic value (e.g. the ME-number) exclusively; rather it is necessary to take all parameters and the operational conditions into consideration. The present article is a study of principles to show the progress of the calculations. It may be enlarged, if necessary, by a heat transfer theory which is accepted today as progressive.

Oplatka, G.

1981-11-01

297

Multi-objective optimization of a cooling tower assisted vapor compression refrigeration system  

Energy Technology Data Exchange (ETDEWEB)

A cooling tower assisted vapor compression refrigeration machine has been considered for optimization with multiple criteria. Two objective functions including the total exergy destruction of the system (as a thermodynamic criterion) and the total product cost of the system (as an economic criterion), have been considered simultaneously. A thermodynamic model based on energy and exergy analyses and an economic model according to the Total Revenue Requirement (TRR) method have been developed. Three optimized systems including a single-objective thermodynamic optimized, a single-objective economic optimized and a multi-objective optimized are obtained. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from the Pareto frontier has been presented. The exergetic and economic results obtained for three optimized systems have been compared and discussed. The results have shown that the multi-objective design more acceptably satisfies generalized engineering criteria than other two single-objective optimized designs. (author)

Sayyaadi, Hoseyn; Nejatolahi, Mostafa [Faculty of Mechanical Engineering-Energy Division, K.N. Toosi University of Technology, P.O. Box 19395-1999, No. 15-19, Pardis Str., Mollasadra Ave., Vanak Sq., Tehran 1999 143344 (Iran, Islamic Republic of)

2011-01-15

298

Dry cooling towers for GT-MHR - HTR2008-58182  

International Nuclear Information System (INIS)

Due to problems with the availability and the price of water, and the concerns relating to adverse environmental effects of wet cooling systems, the need for water conserving cooling systems has been increasing. Presently, dry cooling accounts for over 30, 000 MWe of capacity in more than 30 countries. GT-MHR is specially suited for use of dry cooling due to 1) high efficiency, 2) high heat rejection temperatures and 3) large temperature difference between the turbine inlet and heat rejection temperatures. Higher efficiency means the amount of energy rejected to the cooling per MWe is less. The majority of heat is rejected in pre-cooler and inter-cooler at helium temperature of more than 100 deg. C. This results in higher temperature difference for heat rejection. Also due to large temperature difference between the turbine inlet and heat rejection temperatures, changes in ambient temperature have a smaller effect on overall thermal efficiency. Preliminary evaluation shows that pure dry cooling is economical for GT-MHR for water cost of more than 0.8$/m3 and power cost of 3.5 c/kWh. A combination of dry and wet cooling can reduce large percentage of the water use without affecting the efficiency. (authors)

2008-10-01

299

Structural deficiencies of natural draught cooling towers at UK power stations: Pt. 1; Failures at Ferrybridge and Fiddlers Ferry  

Energy Technology Data Exchange (ETDEWEB)

The collapses of four large reinforced-concrete cooling towers owned by the former Central Electricity Generating Board (CEGB) resulted in two intensive periods of investigation and research into the stress analysis and design of these wind-sensitive structures. This research made it possible for the investigators to conclude that the two failures were not due to the same causes. (author)

Pope, R.A. (National Power plc., Swindon (United Kingdom))

1994-02-01

300

Combined plant installation for the mixing of natural gases and vapour in natural draught wet cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Today suitable combined installations are already available on the market for conveying flue gases through natural draught cooling towers. The new system presented in this paper achieves an almost ideal mixing of flue gas and cooling air. Since it is a question of having available a regulating mechanism which can also be activated by remote control during operation, there is in addition the possibility of adapting the mixture intensity to varying operating conditions. (orig.).

Cossmann, R.; Vodicka, V.

1986-03-01

 
 
 
 
301

Recirculating cooling water solute depletion models  

International Nuclear Information System (INIS)

Chromates have been used for years to inhibit copper corrosion in the plant Recirculating Cooling Water (RCW) system. However, chromates have become an environmental problem in recent years both in the chromate removal plant (X-616) operation and from cooling tower drift. In response to this concern, PORTS is replacing chromates with Betz Dianodic II, a combination of phosphates, BZT, and a dispersant. This changeover started with the X-326 system in 1989. In order to control chemical concentrations in X-326 and in systems linked to it, we needed to be able to predict solute concentrations in advance of the changeover. Failure to predict and control these concentrations can result in wasted chemicals, equipment fouling, or increased corrosion. Consequently, Systems Analysis developed two solute concentration models. The first simulation represents the X-326 RCW system by itself; and models the depletion of a solute once the feed has stopped. The second simulation represents the X-326, X-330, and the X-333 systems linked together by blowdown. This second simulation represents the concentration of a solute in all three systems simultaneously. 4 figs.

1990-01-01

302

Model testing of a deep water compliant tower  

Energy Technology Data Exchange (ETDEWEB)

Laboratory tests were conducted on a 1-to-100 scale model of a compliant offshore tower under deep water conditions. Tests were performed in both regular and irregular waves while measurements of the structure`s deck deflection, base shear force, and overturning moment about the base were obtained. Measured values are compared to simplified theory based on a Single-Degree of Freedom (SDOF) analysis and, in general, the SDOF analysis is shown to adequately describe the structure`s response in regular waves as well as the RMS structural response in random waves. The severe responses in random waves are the result of the impulsive nature of the extreme wave loading and are found to be 5 to 6 times the RMS response.

Kriebel, D.L.; Waters, J.K. [Naval Academy, Annapolis, MD (United States). Ocean Engineering Program

1995-12-31

303

Driving gear for cooling towers - design, noise abatement, maintenance; Antriebssysteme fuer Kuehltuerme - Auslegung, Schallschutz, Instandhaltung  

Energy Technology Data Exchange (ETDEWEB)

Any optimal design of a cooling tower driving gear requires as precise as possible information on the operating conditions in practice. In addition, design engineers use verified data warranting reliable operation of the driving gears. From those data together with information on the specific operating environment and position in the cooling system, engineers derive the application-specific design data for the driving mechanisms, such as for instance special protective coatings, or specific bearing geometries. Other requirements considered include aspects of maintenance and noise abatement. (orig./CB) [Deutsch] Eine optimale Auslegung von Kuehlturmantrieben bedingt eine moeglichst exakte Angabe der Betriebsbedingungen. Darueber hinaus fliessen in die Auslegung Erfahrungswerte ein, die einen stoerungsfreien Betrieb der Getriebe gewaehrleisten. Mit diesen Daten und unter Beruecksichtigung des speziellen Aufstellortes ergibt sich ein kuehlturmspezifisches Getriebe, das z.B. durch den vergroesserten Lagerabstand oder durch die Sonderlackierung den Anforderungen im Kuehlturmbau in groesstmoeglicher Weise gerecht wird. Massgaben hinsichtlich der Wartungsfreundlichkeit und des Geraeuschverhaltens werden bei der Auslegung ebenfalls beruecksichtigt. (orig.)

Niestegge, J.; Plesser, J. [Flender (A.F.) und Co., Bocholt (Germany)

1998-09-01

304

Environmental assessment of air quality, noise and cooling tower drift from the Jersey City Total Energy Demonstration  

Energy Technology Data Exchange (ETDEWEB)

This assessment covers three specific effects from the operation of the Total Energy (TE) demonstration: (1) air quality from combustion emissions of 600 kW diesel engines and auxiliary boilers fueled with No. 2 distillate oil, (2) noise levels from TE equipment operation, (3) cooling tower drift from two, 2220 gpm, forced-draft cooling towers. For the air quality study, measurements were performed to determine both the combustion emission rates and ground-level air quality at the Demonstration site. Stack analysis of NO/sub x/, SO/sub 2/, CO, particulates, and total hydrocarbons characterized emission rates over a range of operating conditions. Ground-level air quality was monitored during two six-week periods during the summer and winter of 1977. The noise study was performed by measuring sound levels in db(A) in the area within approximately 60 m of the CEB. The noise survey investigated the effects on noise distribution of different wind conditions, time of day or night, and condition of doors - open or closed - near the diesel engines in the CEB. In the cooling tower study, drift emission characteristics were measured to quantify the drift emission before and after cleaning of the tower internals to reduce fallout of large drift droplets in the vicinity of the CEB.

Davis, W.T.; Kolb, J.O.

1980-06-01

305

Cathodic protection of a guyed tower in 1000 feet of water  

Energy Technology Data Exchange (ETDEWEB)

The Lena guyed tower and its 20 associated guylines were installed in 1000 ft (305 m) of water in 1983 in Mississippi Canyon Block 280 in the Gulf of Mexico. The design, installation, post construction inspection, and routine monitoring of the 2.4 million lbs (1.1 million kg) of anodes, which provide underwater protection for the tower and guylines, are reviewed.

Rau, J.F.; Michie, T.W.; Smith, S.N.

1986-03-01

306

NASA Marshall Space Flight Center Improves Cooling System Performance: Best Management Practice Case Study #10: Cooling Towers (Fact Sheet)  

Energy Technology Data Exchange (ETDEWEB)

National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) has a longstanding sustainability program that revolves around energy and water efficiency as well as environmental protection. MSFC identified a problematic cooling loop with six separate compressor heat exchangers and a history of poor efficiency. The facility engineering team at MSFC partnered with Flozone Services, Incorporated to implement a comprehensive water treatment platform to improve the overall efficiency of the system.

2011-02-01

307

Operating experience with natural draught wet cooling towers at Arzberg power station of the B. E. L. Company during heavy frost  

Energy Technology Data Exchange (ETDEWEB)

During the freezing periods of 1974/75 and 1975/76 the cooling tower was operated in accordance with the operating instructions provided by the supplier. In spite of consistent adherence to standards heavy ice formations appeared on the splash packing at low temperatures between 0/sup 0/C and 18/sup 0/C. Due to the heavy ice loads the shoulders of the packing in the lower position broke away so that a large number of splash packing sheets fell into the cold water basin causing considerable damage to the splash packing.

Ide, G.

1982-01-01

308

Biocide efficiency against Legionellae and amoebae in cooling towers - the necessity to control the risk of Legionnaires' disease  

Energy Technology Data Exchange (ETDEWEB)

Legionella, known to be the causative agent of Legionnaires' disease, is a wide-spread bacteria occurring naturally in water. Favorable growing conditions in man-made systems can lead to massive growth and thus to a considerable risk for human beings. Evaporative cooling towers provide good living conditions due to their operational conditions. As a consequence, the growth of Legionella in these systems has to be controlled. Amongst other measures biocides are dosed to control the growth of the microbiological population and thus the possible risk of an infection by Legionellae. However, Legionella preferably lives in biofilms and/or amoebae, which strongly shelter this microbe. Furthermore, amoebae by themselves can be harmful to humans as well. Therefore, a biocide treatment should control Legionella (planktonic in water and in biofilms/amoebae) as well as the amoebae. This paper shows that an adapted biocide treatment can increase the efficiency of a biocide against Legionellae and amoebae und therefore minimize the risk of an infection by Legionella. (orig.)

Guhl, W.; Hater, W.; Stumpe, S. [Henkel KGaA, Duesseldorf (Germany)

2007-08-15

309

Guidelines for ozone case histories in cooling water treatment and other applications  

Energy Technology Data Exchange (ETDEWEB)

Too many claims and reports on non-conventional water treatment technologies are still viewed as biased and thereby retarding larger scale acceptance specifically of ozone technology. The reasoning of the ozone treatment successes or its discontinuing due to the failures is not being properly documented. Therefore, this work was accomplished for proposed NACE International Standard ``Guidelines for Case Histories in Ozone Treated Cooling Water,`` to guide in data collecting case histories to be utilized for comparison of cooling tower treatment alternatives.

Burda, P.A. [Pacific Gas and Electric Co. Technology Center, San Ramon, CA (United States)

1994-12-31

310

Optimized performance of surface protection systems on natural draught cooling towers with flue gas discharge; Optimierte Leistungsfaehigkeit von Oberflaechenschutzsystemen in Naturzugkuehltuermen mit Abgaseinleitung  

Energy Technology Data Exchange (ETDEWEB)

Epoxy coatings were applied on the inside shell surface of natural draught cooling towers in the 80s and 90s to protect the surfaces against the acid impact of vapour/flue gas condensate after these cooling towers were retrofitted for discharge of flue gas downstream of FGD. Currently proved perceptions concerning the behaviour of modern coating systems show that they have a significantly increased resistance against operational impacts and environmental influences than the epoxy systems that were used in the 90s. This results in a better performance and higher durability expectations of the protection systems especially on new but also on retrofitted cooling towers. (orig.)

Engelfried, R. [oe.b.u.v. Sachverstaendiger fuer Beschichtungen im Bauwesen, Betoninstandsetzung, Herdecke (Germany); Bandt, N. [RWE Power AG, Technische Dienste Instandhaltungsprojekte, Grevenbroich (Germany); Titze, B. [Vattenfall Europe Generation AG und Co. KG, Cottbus (Germany)

2006-07-01

311

Influence of building and supply conditions on coolant pumps and the various coolant pump designs for cooling towers  

International Nuclear Information System (INIS)

[en] This contribution tries to present the various factors influencing the design of cooling tower pumps. As cooling tower pumps are very often designed as concrete speral casing pumps, the suction bend construction often offers itself. The running wheel of cooling tower pumps is usually of semi-axial design, whereby one has to differ between rigid, adjustable, and resetable running wheels. Finally, the type of cooling system and the nominal width are decisive for either the construction type of the spiral casing pump or the tubular type pump. Both methods are compared in a critical way. (orig.)[de] In diesem Beitrag wird versucht, die verschiedenen Einflussgrossen auf die Bauart von Kuehlturmpumpen darzustellen. Da Kuehlturmpumpen sehr haeufig als Betonspiralgehaesepumpen ausgebildet werden, so bietet sich oft die Bauart des Beschleunigungskruemmers an. Das Laufrad von Kuehlturmpumpen ist in der Regel von halbaxialer Bauart, wobei noch zwischen starren, einstellbaren und verstellbaren Laufraedern zu unterscheiden ist. Die Art des Kuehlverfahrens und die Nennweite der Pumpen geben schliesslich den Ausschlag fuer die Bauart Spiralgehaeusepumpe oder Rohrgehaeusepumpe. Die Regelverfahren werden kritisch untereinander verglichen. (orig.)

1977-01-01

312

Design of, and results of investigations into, indirect cooling for 1200 MW pressurised water reactor power stations  

International Nuclear Information System (INIS)

Indirect dry cooling for extreme air temperature variations from -160C to +420C has been investigated for a site in an earthquake zone which is short of water. In addition, high wind velocities and storms occur at this site. The investigation was based on four similar dry cooling towers operating in parallel,in order to keep broadly within the range of proven ratings for dry cooling towers using this type of cooling system. The results of the optimised design data and of wind tunnel and laboratory investigations are described in detail together with literature studies under prescribed conditions. (orig.)

1980-01-01

313

Improved method for predicting seasonal and annual shadowing from cooling-tower plumes  

Energy Technology Data Exchange (ETDEWEB)

An improved model developed for predicting long-term shadowing due to cooling-tower plumes is presented, and its assumptions are compared with those used in previous models. The model is based on a method for the selection of representative categories of similar plumes developed by Policastro and Dunn to reduce the large number of meteorological data cases in a season or year at a site to a much smaller number, (about 100) of cases which yield distinctively different plume predictions. Plume predictions for the reduced set of category representative cases are then made with the validated plume model. Full effects of sun angle by time of day and day of the year for the latitude and longitude of the site studied are included. The model yields seasonal and annual isopleths of hours of additional shadowing or isopleths of percentage reduction in total and beam solar energy arriving at the ground on a horizontal surface. Results for two hypothetical sites with 2000-MWe generating capacity are presented, one near Syracuse, New York, and the other near Spokane, Washington.

Carhart, R.A.; Policastro, A.J.; Dunn, W.E.

1981-01-01

314

GAST technology program - gas-cooled solar tower power plant. Final report. Technologieprogramm GAST - gasgekuehltes Sonnenturm-Kraftwerk. Schlussbericht  

Energy Technology Data Exchange (ETDEWEB)

Objectives: Analysis/development/test of all essential soft- and hardware techniques necessary for construction of large solar tower power plants (especially gas-cooled ones) to be based on the 20 MW/sub e/ GAST plant reference concept and performed under German-Spanish co-operation by contract of Interatom-Asinel (duration: 01.07.1981 to 31.12.1987). Results: Manufacturing and test of precise heliostats incl. field control meeting the strong requirements of cavity receivers regarding reflected beam quality and pointing accuracy, ready for cost-effective mass-production (MBB/Doernier-System). Erection of a high temperature closed-loop test-cycle with air-cooling (incl. an efficient data acquisition system) on top of the CESA-1 tower in Almeria; performance of successful tests of receiver panels with metallic and ceramic tube heat exchangers followed by hot gas pipe test components under panel air outlet temperatures of 800/sup 0/C resp. 1000/sup 0/C (MAN/Dornier/Interatom). Development of methodes and computer codes for GAST system design/analysis/simulation and techno-economic optimization of plant concepts e.g. within the extensive 'Analysis of the Potential of the GAST System', performed by DFVLR and GAST firms for BMFT. Benefit: All key problems for construction and operation of gas-cooled solar tower plants are clarified; the required soft and hardware technologies are available as well as applicable for alternative tower plant concepts and/or receiver/cycle cooling media. With the GAST concept the high temperature process heat production or power/process heat co-generation seems to be more attractive than pure power generation.

Wehowsky, W.; Kiera, M.; Meinecke, W.; Unger, E. von.

1988-01-01

315

Water quality control and analysis of the secondary cooling system in HANARO  

International Nuclear Information System (INIS)

The secondary cooling system in HANARO includes the chemical injection system. The cooling system has a basin, a cooling tower with four cooling fans, three cooling pumps of 50% capacity, related valves, pipings and instruments. The chemical injection system has two tanks containing different kinds of chemicals, four injection pumps, related valves and pipings. The cooling method is mechanical induced drift type. While the cooling water is circulating, the heat is transmitted to the cooling water in the exchangers and emitted into the often air by forced draft in the cooling tower. Due to the loss of cooling water by evaporation, various kinds of undesirable substances such as salts in solution and micro organisms are accumulated in the cooling water, and they could result in defects such as corrosion, scale, and slime in the system. Therefore, the causes of degradation such as corrosion, scale, and slime are restrained by injection of the chemicals into the cooling water, and the concentration of chemicals is controlled by the periodic blowdown of the cooling water. While the blowdown is nothing but discharging the water out of the system for the control of the cooling water quality, it causes increasing the amount of waste of service water on the contrary. To avoid such counter effect of the blowdown function, the system to operate without blowdown was considered and investigated. Should the system be realized about 100 tons of service water is expected to be saved every working day. In this report, the basic theory is described about the water quality control for the secondary cooling water. The validity and the amount of chemicals being used were reviewed to maintain the water quality. The overall situation of water quality control were analysed as well by reviewing of the quality of cooling water between 1997 and 1999. Furthermore the relation between the number of cycles and the rate of loss of cooling water was confirmed to demonstrate that the secondary cooling water can be managed by high Ca-hardness treatment without blowdown to minimize the loss of cooling water.

2000-01-01

316

Water quality control and analysis of the secondary cooling system in HANARO  

Energy Technology Data Exchange (ETDEWEB)

The secondary cooling system in HANARO includes the chemical injection system. The cooling system has a basin, a cooling tower with four cooling fans, three cooling pumps of 50% capacity, related valves, pipings and instruments. The chemical injection system has two tanks containing different kinds of chemicals, four injection pumps, related valves and pipings. The cooling method is mechanical induced drift type. While the cooling water is circulating, the heat is transmitted to the cooling water in the exchangers and emitted into the often air by forced draft in the cooling tower. Due to the loss of cooling water by evaporation, various kinds of undesirable substances such as salts in solution and micro organisms are accumulated in the cooling water, and they could result in defects such as corrosion, scale, and slime in the system. Therefore, the causes of degradation such as corrosion, scale, and slime are restrained by injection of the chemicals into the cooling water, and the concentration of chemicals is controlled by the periodic blowdown of the cooling water. While the blowdown is nothing but discharging the water out of the system for the control of the cooling water quality, it causes increasing the amount of waste of service water on the contrary. To avoid such counter effect of the blowdown function, the system to operate without blowdown was considered and investigated. Should the system be realized about 100 tons of service water is expected to be saved every working day. In this report, the basic theory is described about the water quality control for the secondary cooling water. The validity and the amount of chemicals being used were reviewed to maintain the water quality. The overall situation of water quality control were analysed as well by reviewing of the quality of cooling water between 1997 and 1999. Furthermore the relation between the number of cycles and the rate of loss of cooling water was confirmed to demonstrate that the secondary cooling water can be managed by high Ca-hardness treatment without blowdown to minimize the loss of cooling water.

Choi, Ho Young; Hwang, S. Y.; Park, Y. C.; Ahn, G. H.; Park, S. J

2000-08-01

317

Micro-Organisms of Cooling Tower Problems and How to Manage Them  

Directory of Open Access Journals (Sweden)

Full Text Available Microorganisms are found everywhere in nature. In air, water and soil are scattered and they are crucial role in the health of humans and animals. many microorganisms are beneficial, while others are pathogenic. Life and activity of microbial processes are effective in many industries. For example, Zugloel bacteria in activated sludge and in the refinery are benefit. They make sludge polysaccharides that help other bacteria digest organic material otherwise organic material into the water receiving effluent and will cause pollution. Conversely, microorganisms that are present in the water cooling system that can be bad effects on the corrosion and deposition create operational efficiencies.

Amir-Samimi

2013-01-01

318

3D simulation of air flow and heat transfers in cooling towers; Modelisation tridimensionnelle des ecoulements d`air et des transferts de chaleur au sein des aerorefrigerants  

Energy Technology Data Exchange (ETDEWEB)

Physical phenomena in cooling towers are complex and often diminish the efficiency of the turbine. So, in order to better understand the air flow and heat transfers phenomena in the exchange areas of existing cooling towers, EDF has developed a 3D CFD code named N3S-AERA. Furthermore the impact of new components or technologies could be computed and the results help us to understand the behaviour of the flow. (authors)

Fournier, Y.; Denis, C. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique

1999-04-01

319

Dynamical calculation comparison process for two concrete construction methods for natural draught cooling towers. Dynamisch-kalkulatorischer Verfahrensvergleich zweier Ortbetonbauverfahren fuer Naturzugkuehlerschalen  

Energy Technology Data Exchange (ETDEWEB)

A dynamic calculation comparison process is submitted for the manufacture of the shells of natural draught cooling towers for the two methods of construction - climbing and sliding. It should help to make the right decision on the economically more favourable process. A basis of comparison (calculated costs) is introduced for the many effects on the individual decision in the whole complex construction of a natural draught cooling tower. A discrete model calculation based on realistic operation is also derived from this. (GB).

Dietrich, K.

1981-01-01

320

18 CFR 420.44 - Cooling water.  

Science.gov (United States)

...Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION...ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used exclusively for...

2013-04-01

 
 
 
 
321

Air-cooled heat pump with desuperheater: retrofit for year-round service hot water supply  

Energy Technology Data Exchange (ETDEWEB)

In a case study project an air-cooled heat pump unit was retrofitted with a desuperheater to provide service hot water in addition to chilled water for comfort space cooling in a 24-room holiday villa located in a subtropical region. The retrofit project is described, and system operating performance and energy efficiency are reported. A standard cooling tower was used to extract free heat from ambient air in transitional seasons, thus eliminating the need for electric backup heating for service hot water. (author)

Deng, S.; Tan, K. [Hong Kong Polytechnic University (China). Dept. of Building Services Engineering; Song, Z. [Tong Ji University, Shanghai (China). Dept. of Thermal Engineering

1998-12-31

322

Pulsed cooling-water systems for actively cooled beam dumps  

International Nuclear Information System (INIS)

[en] A pulsed water system offers an economically attractive way of supply cooling water for beam dumps, as the water flow and pressure requirements increase. A pilot system was built and used in testing prototype beam dumps. Operating experience gained with the pulsed water system has proved the feasibility of this design

1981-10-29

323

Biofouling Control in Cooling Water  

Directory of Open Access Journals (Sweden)

Full Text Available An important aspect of environmental engineering is the control of greenhouse gas emissions. Fossil fuel-fired power stations, for instance, represent a substantial contribution to this problem. Unless suitable steps are taken the accumulation of microbial deposits (biofouling) on the cooling water side of the steam condensers can reduce their efficiency and in consequence, the overall efficiency of power production, with an attendant increase in fuel consumption and hence CO2 production. Biofouling control, therefore, is extremely important and can be exercised by chemical or physical techniques or a combination of both. The paper gives some examples of the effectiveness of different approaches to biofouling control.

T. Reg Bott

2009-01-01

324

Passive containment cooling water distribution device  

Energy Technology Data Exchange (ETDEWEB)

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using a series of radial guide elements and cascading weir boxes to collect and then distribute the cooling water into a series of distribution areas through a plurality of cascading weirs. The cooling water is then uniformly distributed over the curved surface by a plurality of weir notches in the face plate of the weir box.

Conway, Lawrence E. (Hookstown, PA); Fanto, Susan V. (Plum Borough, PA)

1994-01-01

325

The influence of inlet system and inlet conditions on the cooling pumps and on the different types of coolant pumps for cooling towers  

International Nuclear Information System (INIS)

[en] The paper attempts to give the influencing parameters determining the type of cooling pump to be constructed. As cooling pumps are often constructed as pumps with a spiral concrete housing, the suction bend construction appears to be the most suitable. The impeller of cooling tower pumps is usually semiaxial. The type of pump - pump with spiral housing or pump with tubular housing - is determined by the cooling process and the nominal bore of the pump. Of the control techniques known, rotor blade control and inlet vane control are suitable for cooling tower pumps. The two methods of control are critically compared. (orig.)[de] In diesem Referat wird versucht, die verschiedenen Einflussgroessen auf die Bauart von Kuehlturmpumpen darzustellen. Da Kuehlturmpumpen sehr haeufig als Betonspiralgehaeusepumpen ausgebildet werden, so bietet sich oft die Bauart des Beschleunigungskruemmers an. Das Laufrad von Kuehlturmpumpen ist in der Regel von halbaxialer Bauart. Die Art des Kuehlverfahrens und die Nennweite der Pumpe geben den Ausschlag fuer die Bauart Spiralgehaeusepumpe oder Rohrgehaeusepumpe. Von den bekannten Regelverfahren bieten sich bei Kuehlturmpumpen die Laufschaufelverstellung und die Vorleitradschaufelverstellung an. Beide Regelverfahren werden kritisch miteinander verglichen. (orig.)

1976-05-21

326

Performance of hydrogen peroxide as a cooling water biocide and its compatibility with other cooling water inhibitors  

Energy Technology Data Exchange (ETDEWEB)

Hydrogen peroxide has been evaluated in a pilot cooling tower system as an alternative to continuous chlorination and intermittent dosing with non-oxidizing biocides. Hydrogen peroxide demand in the cooling system was considerably higher than predicted based on its vapor pressure and spontaneous decomposition in alkaline waters. This might be explained by the selection of peroxidase and catalase positive organisms in the cooling water which decompose hydrogen peroxide to water and oxygen. Although continuous feed of 2 to 3 ppm of hydrogen peroxide failed to control the bulk water bacterial population, it did suppress the growth of sessile organisms. Hydrogen peroxide was found to be corrosive toward mild steel and copper. However this effect could be adequately controlled through the use of proprietary corrosion inhibitors. Deposit control agents selected for their ability to withstand oxidation by hydrogen peroxide were highly successful in maintaining a low rate of scale formation. Based on these observations and the environmentally friendly nature of hydrogen peroxide, its use as an alternative cooling water biocide should be further explored.

Coughlin, M.F.; Steimel, L. [Diversey Lever Inc., Cincinnati, OH (United States)

1997-12-01

327

Assessment of the suitability of agricultural waste water for geothermal power plant cooling in the Imperial Valley. I. Water quality  

Energy Technology Data Exchange (ETDEWEB)

Evaluation of the quality of agricultural waste water is the first step in assessing the sitability of agricultural waste water for geothermal power plant cooling. In this study samples of agricultural waste water from the New and Alamo rivers located in the Imperial Valley of California are analyzed. Determinations of standard water quality parameters, solids content, and inorganic compositions of the solids are made. The results are compared with data on samples of irrigation water and steam condensate also obtained from sites in the Imperial Valley. The data are evaluated in relation to cooling tower operation, waste generation, and waste disposal.

Morris, W.F.; Rigdon, L.P.

1981-09-01

328

European supercritical water cooled reactor  

International Nuclear Information System (INIS)

[en] Highlights: ? The HPLWR reactor design is an example of a supercritical water cooled reactor. ? Cladding material tests have started but materials are not yet satisfactory. ? Numerical heat transfer predictions are promising but need further validation. ? The research project is most suited for nuclear education and training. - Abstract: The High Performance Light Water Reactor (HPLWR), how the European Supercritical Water Cooled Reactor is called, is a pressure vessel type reactor operated with supercritical water at 25 MPa feedwater pressure and 500 oC average core outlet temperature. It is designed and analyzed by a European consortium of 10 partners and 3 active supporters from 8 Euratom member states in the second phase of the HPLWR project. Most emphasis has been laid on a core with a thermal neutron spectrum, consisting of small fuel assemblies in boxes with 40 fuel pins each and a central water box to improve the neutron moderation despite the low coolant density. Peak cladding temperatures of the fuel rods have been minimized by heating up the coolant in three steps with intermediate coolant mixing. The containment design with its safety and residual heat removal systems is based on the latest boiling water reactor concept, but with different passive high pressure coolant injection systems to cause a forced convection through the core. The design concept of the steam cycle is indicating the envisaged efficiency increase to around 44%. Moreover, it provides the constraints to design the components of the balance of the plant. The project is accompanied by numerical studies of heat transfer of supercritical water in fuel assemblies and by material tests of candidate cladding alloys, performed by the consortium and supported by additional tests of the Joint Research Centre of the European Commission. Besides the scientific and technical progress, the HPLWR project turned out to be most successful in training the young generation of nuclear engineers in the technologies of light water reactors. More than 20 bachelor or master theses and more than 10 doctoral theses on HPLWR technologies have been submitted at partner organizations of this consortium since the start of this project.

2011-01-01

329

The cooling water from Ringhals  

International Nuclear Information System (INIS)

[en] The Ringhals Nuclear Power Plant is situated on the Swedish west coast about 70 km south of Gothenburg. At present two units operate at a total maximum power level of 1580 MWE and their once-through cooling system requires 80 m3/sec sea water. The temperature of the cooling water increases approximately 10 deg C. This study assesses the spreading of the discharged cooling water in the ambient sea and is based on field data sampled since the end of 1974. About 50 thermal mappings were made in the area by boat or in some cases by aeroplane. Several continously recording current and temperature instruments were used. Water samples analysed for salinity, oxygen and turbidity were collected most of the time. Through the thermal mappings four main directions of the thermal plume were distinguished: northward along the coast (class 1A), northward further out (class 1B), westward and reversing plumes (class 2) and southward (class 3). The changing of the plume hour by hour between these main directions was measured by the recording temperature instruments. Data from almost one year gave the following statistics: 40 percent class 1A + 1B, 15 percent class 2, 25 percent class 3 and 20 percent undefined directions. Furthermore, available data showed that the direction of the ambient current mostly gave the plume direction. The wind, on the other hand, was more uncertain as an indicator of the plume direction. Owing to the varying ambient currents the plume changed its direction more than once a day. Measurable excess temperatures were found within a few kilometers wide zone from Stavder in the north to Norra Horta in the south. The largest measured area with excess temperatures of more than 1 deg C was 6 km2. Usually, however, the plume covered about 2.5 km2 at full production at the power plant. As for the downward spreading, the bottom of the plume normally registrated down to 3-7 m, but occasionally it reached the 10 - 12 m level. The tendency of deep penetration increased with decreasing ambient temperature. (author)

1980-01-01

330

Legionnaires’ disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background An outbreak of Legionnaires’ Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Methods Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Results Thirty-two cases were found. The median age was 62 years (range 36 – 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Conclusions Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods. The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak.

Ulleryd Peter; Hugosson Anna; Allestam Görel; Bernander Sverker; Claesson Berndt EB; Eilertz Ingrid; Hagaeus Anne-Christine; Hjorth Martin; Johansson Agneta; de Jong Birgitta; Lindqvist Anna; Nolskog Peter; Svensson Nils

2012-01-01

331

Rehabilitation of two natural draught cooling towers at Grohnde 1300 MW nuclear power station, taking into account a completely new concept. Sanierung von zwei Naturzugkuehltuermen im 1300-MW-Kernkraftwerk Grohnde  

Energy Technology Data Exchange (ETDEWEB)

The natural draught cooling towers for Grohnde Nuclear Power Station were completed in 1983. During the operating period from 1984 to 1990, partial areas of these cooling tower structures collapsed. A combination of high performance cooling installations with so-called spray screens were offered for the necessary rehabilitation. Since rehabilitation of both cooling towers had to be carried out during the operation of the power station, parts of the surfaces of the cooling towers were closed off in order to be able to carry out the difficult installation of the structures. Acceptance measurements have confirmed the thermodynamic calculations. (orig.).

Schwickert, M. (Hamon Sobelco GmbH, Bochum (Germany)); Meyer, V. (Gemeinschaftskernkraftwerk Grohnde GmbH, Emmerthal (Germany))

1992-08-01

332

Cooling of energy production plants by means of ground water; Koeling energiecentrales met grondwater mogelijk  

Energy Technology Data Exchange (ETDEWEB)

The problem of cooling water for electric power generating plants caused a capacity shortage in the Netherlands in the hot summer of 2003. To prevent such a shortage several alternatives are discussed, e.g. the use of cooling towers. However, cooling by means of ground water appears to be a good alternative. [Dutch] Het koelwaterprobleem van elektriciteitscentrales zorgde in Nederland tijdens de hete zomer van 2003 voor een dreigend productietekort. Om in de toekomst een echt capaciteitstekort te voorkomen zijn verschillende alternatieven genoemd, zoals het plaatsen van koeltorens. Koeling met grondwater is echter een eleganter alternatief.

Willemsen, G. [Business Development, IF Technology, Arnhem (Netherlands)

2003-10-01

333

Site testing of condenser cooling water pumps  

International Nuclear Information System (INIS)

[en] Problems encountered during the testing of the cooling water pumps at the RAPP-2 site are discussed. The reasons for in situ testing are explained. The parameters to be measured and the methods of measurement with special emphasis on flow measurement are described. The technique employed in the discharge measurement of cooling water pumps of RAPP-2 is dealt with in detail. The proposed test loop for MAPP cooling water pump testing is also touched upon. (K.B.)

1977-02-09

334

The cool shopping centre of the Netherlands. The realization of four cooling units in Utrecht, Netherlands; Het koele winkelhart van Nederland. Realisatie vier koudecentrales in Utrecht  

Energy Technology Data Exchange (ETDEWEB)

A brief description is given of a project to install four cooling machines (absorption cooling, compression cooling, cooling towers, and water treatment units) in the office and shopping centre Hoog Catharijne in Utrecht, Netherlands. 3 ills., 1 tab.

NONE

1997-11-01

335

Effects of atmospheric aerosols and evaporation processes in the precipitation region on the emissions of wet cooling systems, illustrated by the example of industrial natural-draught cooling towers. Einfluss der atmosphaerischen Aerosolbeladung und der Verdunstungsprozesse im Regengebiet auf die Emissionen aus Nasskuehlanlagen am Beispiel grosser Naturzug-Nasskuehltuerme  

Energy Technology Data Exchange (ETDEWEB)

Entrained cooling water droplets emitted by wet cooling systems contain the cooling water constituents, while the recondensation droplets formed contain constituents that entered the cooling system as aerosols with the ambient air or as a result of evaporation of small coolant droplets. When the entrained volume of cooling water is measured, the contribution of recondensation droplets leads to a positive error of measurement which may be in the order of the exact measured value. Evaporation and washout processes in the precipitation area of a counterflow-type natural-draught wet cooling tower were calculated. Aerosol production from entrained cooling water droplets was found to be low, and aerosol particle mass concentrations downstream of the precipitation area were found to differ significantly across the cooling tower radius. Supplementary measurements on particle deposition and droplet evaporation in a laboratory-size plant indicate that the calculated separation efficiencies are the lower limit, and that very fine droplets generated in the precipitation zone of the plant evaporate in a significant volume only of the sucked-in air is unusually dry. (orig.) With 52 figs., 11 tabs.

Backhaus, A.

1990-01-01

336

Legionella, cooling towers, air conditioning and the Internet. An update; Legionella, koeltorens, luchtbehandeling en Internet. Een update  

Energy Technology Data Exchange (ETDEWEB)

A review was made in 2001 with respect to information on Internet about the occurrence of Legionella bacteria in cooling towers and air conditioning installations. A comparable research was carried out in 2004. It appears that now more than twice the amount of information is available than in 2001. [Dutch] In 2001 is een overzicht gemaakt van de informatie die via Internet te vinden is over de verspreiding van Legionella-bacterien via koeltorens en luchtbehandelinginstallaties. Deze zoektocht is in 2004 herhaald. Er werden ruim tweemaal zoveel relevante websites gevonden. Een kort overzicht van de verkregen informatie wordt gegeven.

Moerman, P.C.

2004-06-01

337

Experimental investigation on a one-step centripetal blower as a model of a blower to ventilate cooling towers  

International Nuclear Information System (INIS)

Model tests were performed on a one-step centripetal blower (impeller external diameter of 1 m) whose aim was to clarify whether this kind of blower is suitable to ventilate a cooling tower. Aside from the investigation of the general operational behaviour, it was above all important in the tests to investigate the sensitivity of the centripetal blower to rotating tearing with regular flow as well as with side wind, as the main difficulty was suspected in controlling the blower with side wind. (orig./LN).

1973-01-01

338

Reinforced concrete corrosion: application of Bayesian networks to the risk management of cooling towers in nuclear plants  

International Nuclear Information System (INIS)

Degradation modeling of concrete structures uses uncertain variables and leads, using reliability assessment, to time dependant evolution of failure probabilities. However, only few data are generally available to feed models leading to two types of uncertainties: an intrinsic one depending on the modeled phenomena and one related to the precision of the measurements. Each new data available is a piece of information which allows updating the initial prediction. In this article, an example of updating process, based on a Bayesian network, is presented and applied on the corrosion risk of a cooling tower in a nuclear plant. (authors)

2007-01-01

339

Water Cooled FBNR Nuclear Reactor  

International Nuclear Information System (INIS)

A new era of nuclear energy is emerging through innovative nuclear reactors that are to satisfy the new philosophies and criteria that are developed by the INPRO program of the International Atomic Energy Agency (IAEA). The IAEA is establishing a new paradigm in relation to nuclear energy. The future reactors should meet the new standards in respect to safety, economy, non-proliferation, nuclear waste, and environmental impact. The Fixed Bed Nuclear Reactor (FBNR) is a small (70 MWe) nuclear reactor that meets all the established requirements. It is an inherently safe and passively cooled reactor that is fool proof against nuclear proliferation. It is simple in design and economic. It can serve as a dual purpose plant to produce simultaneously both electricity and desalinated water thus making it especially suitable to the needs of most of developing countries. FBNR is developed with the support of the IAEA under its program of Small Reactors Without On-Site Refuelling (SRWOSR). The FBNR reactor uses the pressurized water reactor (PWR) technology. It fulfills the objectives of design simplicity, inherent and passive safety, economy, standardization, shop fabrication, easy transportability and high availability. The inherent safety characteristic of the reactor dispenses with the need for containment; however, a simple underground containment is envisaged for the reactor in order to reduce any adverse visual impact. (author)

2011-01-01

340

Corrosion-induced Whole Effluent Toxicity from a cooling tower: A toxicity reduction evaluation case study  

Energy Technology Data Exchange (ETDEWEB)

As the result of Whole Effluent Toxicity (WET) test failures with Daphnia pulex, the US Environmental Protection Agency (EPA) required an industrial facility discharging approximately 5 million gallons per day (MGD) of recirculating cooling water obtained from a large freshwater river to conduct a Toxicity Reduction Evaluation (TRE) program. Under the terms of the National Pollutant Discharge Elimination System (NPDES) permit, the facility was required to conduct 48-hour acute toxicity tests with D. pulex and Pimephales promelas (fathead minnow). Although effluent toxicity to D. pulex was consistently observed, no toxicity was induced to the fathead minnow during the TRE program. The situation was further complicated by the fact that the recirculating cooling water was discharged back into the same river. The objectives of the TRE program were to investigate the causes of toxicity, locate potential sources of the suspected toxicant(s), and identify practicable toxicity reduction methodologies to be used. The TRE program approach and results from the associated studies are presented in this report, including a successful remedy for the WET problem.

Fort, D.J.; Stover, E.L.; Talley, J.M.; Copenhaver, M.B. [Stover Group, Stillwater, OK (United States)

1996-11-01

 
 
 
 
341

Emergency cooling of presurized water reactor  

International Nuclear Information System (INIS)

The method described of emergency core cooling in the pressurized water reactor is characterized by the fact that water is transported to the disturbed primary circuit or direct to the reactor by the action of the energy and mass of the steam and/or liquid phase of the secondary circuit coolant, which during emergency core cooling becomes an emergency cooling medium. (B.S.)

1981-01-01

342

Metallic uranium production in water cooled plant  

International Nuclear Information System (INIS)

Specific features of calcium-thermic reduction of UF4 in a water-cooled plant are under consideration. Plant design is schematically represented and processing procedures for metallic uranium castings production are described. A particular attention is paid to service life of the basic part of the plant, namely, of reaction water cooled chromium bronze tube. 2 refs., 1 fig.

1995-01-01

343

Cooling towers. State-of-art report interpreting the 3rd international symposium on 'Natural draught cooling towers', Paris (France), April 24 to 26, 1989. Kuehltuerme. State-of-Art-Report in Auswertung des 3. Internationalen Symposiums 'Naturzugkuehltuerme', Paris, 24. bis 26. April 1989  

Energy Technology Data Exchange (ETDEWEB)

150 professional experts of a great number of countries were taking part in the 3rd International Symposium on 'Natural Draught Cooling Towers' held in Paris from April 24 to 26, 1989. The symposium had been organized by the IASS, EDF and SCAM. More than 70 papers were providing an excellent survey of the actual state concerning the design, construction and calculation as well as the production, reconstruction and repair of large-size cooling towers. (orig.).

Hampe, E. (Hochschule fuer Architektur und Bauwesen, Weimar (Germany, F.R.). Wissenschaftszentrum Industrie- und Spezialbau)

1990-01-01

344

Heat transfer technology atmospheric cooling equipment, water consumption  

Energy Technology Data Exchange (ETDEWEB)

Presently evaporating water is still the most economical way to dissipate waste heat. When insufficient water supply is available, there is little that can be done in the design of an evaporative tower to reduce evaporation. Combination of wet towers and dry coolers, either as separate units or as combined systems is the only presently known practical method to reduce evaporation.

LeFevre, M.

1984-08-01

345

Application of an Optimum Design of Cooling Water System by Regeneration Concept and Pinch Technology for Water and Energy Conservation  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, using a combination of Pinch Technology and Mathematical Programming, a new technique is presented in order to grass-root design for a cooling water system to achieve minimum total annual cost. The presented technique is further improved by using patterns from the concept of regeneration recycling in water systems; in a sense that cooling water is regenerated locally by an air cooler. Moreover, in the proposed method, optimum design of cooling tower has been achieved through a mathematical model. Related coding in MATLAB version 7.3 was used for the illustrative example to get optimal values in the proposed cooling water design method computations. The result of the recently introduced design methodology was compared with the conventional and Kim and Smith design methods. The outcomes indicate that by using this new design method, more water and energy can be saved and a lower level of total annual cost can be reached.

A. Ataei; M.H. Panjeshahi; R. Parand; N. Tahouni

2009-01-01

346

New dimensions in the construction of natural-draught cooling towers; Neue Dimensionen beim Bau von Naturzugkuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

The natural draught cooling towers of the projected RWE power units in the Rhenish lignite coal area will reach a height of 200 m, thus being the largest cooling towers worldwide. This extrapolation of today`s knowledge needs to be accompanied by intensified research work, especially considering - realistic wind action including interference effects; - dynamic response taking into account the ageing of the concrete structure; - optimization of the shell shape with respect to favourable load bearing behaviour. Furtheron, the requirements of the planned cleaned gas inflow in a height of about 50 m have to be taken into account. The contribution will report on the state of research, supported by the Deutsche Forschungsgemeinschaft and by the RWE Energie AG. (orig.) [Deutsch] Mit Hoehen von 200 Metern werden die Naturzugkuehltuerme der projektierten Kraftwerke der RWE Energie AG im niederrheinischen Braunkohlerevier die mit Abstand groessten der Welt werden. Diese Extrapolation des bisherigen Erfahrungsbereiches erfordert eine sorgsame Erforschung der wirklichkeitsnahen Windeinwirkungen unter Einschluss von Interferenzen, der dynamischen Tragwerksantwort bei Beruecksichtigung der realen Alterung der Stahlbeton-Struktur und der im Hinblick auf die Dauerhaftigkeit guenstigsten Schalenform. Daneben sind auch die Erfordernisse der vorgesehenen Reingaseinleitung in einer Hochlage von etwa 50 m besonders zu beruecksichtigen. Der Beitrag wird ueber den Stand der diesbezueglichen, von der Deutschen Forschungsgemeinschaft und der RWE Energie AG gefoerderten Arbeiten berichten. (orig.)

Harte, R. [Wuppertal Univ. (Gesamthochschule) (Germany). Lehrstuhl Baustatik; Kraetzig, W.B. [Bochum Univ. (Germany). Lehrstuhl fuer Statik und Dynamik; Zahlten, W. [Technische Hochschule Aachen (Germany). Lehrstuhl fuer Baustatik

1998-12-31

347

Design and application-specific design features of wet cooling towers and their impact on economic efficiency of the cooling system; Einfluss der Auslegung und Auswahl eines Nasskuehlturms auf die Wirtschaftlichkeit der Wasserrueckkuehlanlage  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers and their required and appropriate design features continue to be an issue of debate among owners/operators, planning engineers and manufacturers. Often, the requirements and interests of the parties involved cannot be reconciled. Such incompatible requirements for instance are all as-low-as-possible requirements, relating to cold water temperatures - investment cost - performance requirements - noise emissions. Any requirement on its own can be met without problems, but their combination is the crucial aspect, and of course the compromise to be found has to be as near to an optimal solution as possible. Meeting the requirement of low cold water temperature for instance, with a close approach (a), implies that the cooling tower must be a large structure, needing high investment, which in turn can be justified if the design ensures a higher performance efficiency of the system or equipment to be cooled while reducing operating costs. (orig./CB) [Deutsch] Kuehltuerme und ihre Auslegung geben immer wieder Anlass zu Diskussionen zwischen Betreibern, Planern und Herstellern. Oft stehen sich Forderungen gegenueber, die miteinander nicht in Einklang zu bringen sind, wie z.B. - Kaltwassertemperatur so tief wie moeglich - Investitionskosten so niedrig wie moeglich - Leistungsbedarf so gering wie moeglich - Schallemission so wenig wie moeglich. Jede Forderung fuer sich betrachtet, kann erfuellt werden. Gefragt ist jedoch ein Kompromiss, der - bezogen auf die Gesamtanlage - ein Optimum darstellt. So bedeutet beispielsweise eine geringe Kaltwassertemperatur mit einem kleinen Kuehlgrenzabstand (a) die Wahl eines grossen Kuehlturms mit einer hohen Investitionssumme. Diese ist gerechtfertigt, wenn dadurch der Wirkungsgrad der zu kuehlenden Anlage oder Maschine vergroessert und die Betriebskosten damit verringert werden. (orig.)

Knopf, M. [GEA Management Gesellschaft fuer Waerme- und Energietechnik mbH, Nonnenhorn (Germany)

1998-09-01

348

Plant engineering solution for the introduction of desulphurized flue gases into natural draught wet cooling towers at brown coal-fired power stations  

Energy Technology Data Exchange (ETDEWEB)

With the support of various institutes and manufacturers an investigation has been undertaken into how the gases cleansed in the wet flue gas desulphurization plants can be introduced into the existing natural draught cooling towers at brown coal-fired power stations and can, mixed with the cooling air mass flow, be discharged into the atmosphere. Technical procedures have been developed which permit the cleansed flue gases to be discharged with the vapour from the tower in an economic and environmentally acceptable manner which does not impair availability. The initial conversion measures have been started.

Andres, O.; Hampel, G.

1986-10-01

349

Thermal calculations for water cooled research reactors  

International Nuclear Information System (INIS)

[en] The formulae and the more important numerical data necessary for thermic calculations on the core of a research reactor, cooled with low pressure water, are presented. Most of the problems met by the designer and the operator are dealt with (calculations margins, cooling after shut-down). Particular cases are considered (gas release, rough walls, asymmetric cooling slabs etc.), which are not generally envisaged in works on general thermics

1979-01-01

350

AFCATT (Anti-Fouling Chemical Additive Test Tower)  

Energy Technology Data Exchange (ETDEWEB)

Polyvinylchloride (PVC) film-type cellular fill is the fill of choice in replacing cement asbestos board fill in existing cooling towers and in new cooling towers because of its high thermal performance, ease of installation, and low initial cost. However, PVC fill has been found to foul quickly with biological and sediment material, significantly reducing tower performance and the fill`s useful life. The Anti-Fouling Chemical Additives Test Tower (AFCATT) has been build to study accumulation rates of fouling deposits in corrugated PVC film fill and to study methods of cleaning and preventing the fouling deposits. This small mechanical draft cooling tower is located next to the Unit 4 natural draft cooling tower at Georgia Power Company`s Plant Bowen. The once-through mechanical draft tower receives hot water from the condenser and returns the cold water to the basin of the host tower. The pilot tower is divided into four chambers allowing for three different treatment programs and one control to be run simultaneously. PVC fill packs are suspended from load cells to allow the weight of the fill packs to be measured continuously. Six vendors participated in the summer 1993 test program. Each proposed different methods of cleaning the fouled fill and were given the opportunity to try their proposed method of fill cleaning. To determine the success of these different treatment programs, statistical analyses were performed on the collected data and the changes in the accumulation rates compared.

Philpot, E.F.; Newton, M.T.; Noble, R.T. [Southern Company Services, Birmingham, AL (United States)] [and others

1995-06-01

351

"Hot" for Warm Water Cooling  

Energy Technology Data Exchange (ETDEWEB)

Liquid cooling is key to reducing energy consumption for this generation of supercomputers and remains on the roadmap for the foreseeable future. This is because the heat capacity of liquids is orders of magnitude larger than that of air and once heat has been transferred to a liquid, it can be removed from the datacenter efficiently. The transition from air to liquid cooling is an inflection point providing an opportunity to work collectively to set guidelines for facilitating the energy efficiency of liquid-cooled High Performance Computing (HPC) facilities and systems. The vision is to use non-compressor-based cooling, to facilitate heat re-use, and thereby build solutions that are more energy-efficient, less carbon intensive and more cost effective than their air-cooled predecessors. The Energy Efficient HPC Working Group is developing guidelines for warmer liquid-cooling temperatures in order to standardize facility and HPC equipment, and provide more opportunity for reuse of waste heat. This report describes the development of those guidelines.

IBM Corporation; Energy Efficient HPC Working Group; Hewlett Packard Corporation; SGI; Cray Inc.; Intel Corporation; U.S. Army Engineer Research Development Center; Coles, Henry; Ellsworth, Michael; Martinez, David J.; Bailey, Anna-Maria; Banisadr, Farhad; Bates, Natalie; Coghlan, Susan; Cowley, David E.; Dube, Nicholas; Fields, Parks; Greenberg, Steve; Iyengar, Madhusudan; Kulesza, Peter R.; Loncaric, Josip; McCann, Tim; Pautsch, Greg; Patterson, Michael K.; Rivera, Richard G.; Rottman, Greg K.; Sartor, Dale; Tschudi, William; Vinson, Wade; Wescott, Ralph

2011-08-26

352

River and cooling water temperature fluctuations  

International Nuclear Information System (INIS)

Cooling water discharged from a power plant changes the fluctuating water temperature characteristics of a receiving river in a clearly detectable way. Daily and hourly water temperature data from two power plant sites on the Upper Mississippi River were used to compute for illustration the magnitude of such differences. Extreme value analysis, autocovariance and spectral analysis, and nonlinear curve fitting methods were applied alternatively. Amplitudes of seasonal periodicities, of diurnal periodicities, and of random components were determined. The results indicate that time series analysis of water temperatures measured downstream from an existing cooling water outfall may provide equally or even more realistic and useful information on the size of a cooling water plume than quasi-instantaneous surveys of spatial water temperature distributions

1976-01-01

353

A simulation-based method to analyse the behaviour of rc cooling towers shells; Methode basee sur la simulation numerique pour analyser le comportement des aerorefrigerants en beton arme  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with numerical simulations undertaken for the service life and maintenance management of EDF cooling towers. Following a presentation of the industrial context and of the numeric tools dedicated to RC structure ageing, two finite element models are presented. The first one aims at simulating the collapse of a tower fallen down in 1979, the second one is devoted to the assessment of damages undergone by cooling towers during the 1999 tempest in France. (authors)

Courtois, A.; Ravet, S. [Electricite de France (EDF/SEPTEN), 69 - Villeurbanne (France); Barnel, N. [Electricite de France (EDF RD), 77 - Moret sur Loing (France)

2007-07-01

354

Long life radioactive nuclides in the KUR cooling water and waste water used for regeneration of ion exchange resin for purifing the water  

International Nuclear Information System (INIS)

[en] Radioactive nuclides in the reactor cooling water are concentrated in the ion exchange tower. Resins saturated by radioactive nuclides are regenerated at desired times. Consequently, a large amount of radioactive waste water used are obtained. Since this waste water has high concentration of salts, and it is difficult to treat. In order to treat efficiently the waste water, it needs at least to know the kinds of radioactive nuclide present in the waste water prior to the treatment. Long life radioactive nuclides in the cooling water and waste water were identified by the ?-ray spectroscopy. Nuclides detected are as follows: 65Zn, 141Ce, 124Sb, 51Cr and 137Cs in the cooling water, and 137Cs, 95Zr-Nb, 144Ce, 51Cr, 60Co and 65Zn in the waste water used for regenerated of resin. (auth.)

1974-01-01

355

Outbreak of legionnaires' disease from a cooling water system in a power station (Heysham)  

International Nuclear Information System (INIS)

[en] In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures. (author)

1986-01-01

356

Outbreak of Legionnaires' disease from a cooling water system in a power station (Heysham)  

Energy Technology Data Exchange (ETDEWEB)

In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.

Morton, S.; Dyer, J.V.; Bartlett, C.L.R.; Bibby, L.F.; Hutchinson, D.N.; Dennis, P.J.

1986-09-01

357

Fish-eye view from the water tower towards Jura  

CERN Multimedia

In the very front, the cooling plant for the ISR magnets followed by Storage (housing ISR electric generators)and CAO (Control Accelerator Operation) Buildings (Bld 378-377), and the main Building of the ISR Division (Bld 30). Behind stands the West Hall, followed along the neutrino beam line, by the BEBC building, the building housing the neutrino experiments WA1 and WA18, and the Gargamelle Building.

1977-01-01

358

One hundred years of natural-draught cooling tower. The `cool end` of electricity generation celebrates its centennial; 100 Jahre Naturzug-Kuehlturm. Das ``kuehle Ende`` der Stromerzeugung feiert Jubilaeum  

Energy Technology Data Exchange (ETDEWEB)

Looming upto 200 m high into the sky like waisted giant tubes, natural-draught cooling towers typify the appearance of power plants throughout the world. In shape and statics these grey-shelled core-cooled giants are relatives of the Eiffel Tower in Paris. One thing the natural-draught cooling tower reflects more than anything else in the 100 years` development since its introduction to the market is the advance of power plant technology and industrialisation. (orig.) [Deutsch] Sie ragen wie dynamisch geschwungene Riesen-Roehren bis zu 200 Meter hoch in den Himmel und praegen das Erscheinungsbild von Kraftwerken in aller Welt: Naturzug-Kuehltuerme. In Form und Statik sind diese Giganten mit grauer Schale und kuehlem Kern Verwandte des Pariser Eiffelturms. Seit seiner Markteinfuehrung vor 100 Jahren spiegelt die Entwicklung des Naturzug-Kuehlturms aber vor allem eines wieder: Den Fortschritt der Kraftwerkstechnik und der Industrialisierung. (orig.)

Anon.

1995-01-01

359

PEP cooling water systems and underground piped utilities design criteria report  

International Nuclear Information System (INIS)

This paper discusses the cooling systems required by the PEP Storage Ring. Particular topics discussed are: Cooling tower systems, RF cavity and vacuum chamber LCW cooling systems, klystron and ring magnet LLW cooling systems, Injection magnet LCW Cooling Systems; PEP interaction area detector LCW Cooling Systems; and underground piped utilities. 1 ref., 20 figs

1975-01-01

360

Air and water cooled modulator  

Energy Technology Data Exchange (ETDEWEB)

A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air.

Birx, Daniel L. (Oakley, CA); Arnold, Phillip A. (Livermore, CA); Ball, Don G. (Livermore, CA); Cook, Edward G. (Livermore, CA)

1995-01-01

 
 
 
 
361

Evaporative cooling: water for thermal comfort  

Directory of Open Access Journals (Sweden)

Full Text Available Evaporative cooling is an environmentally friendly air conditioning system that operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists, specifically, in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents three methods that can be used as reference for efficient use of evaporative cooling systems, applying it to several Brazilian cities, characterized by different climates. Initially it presents the basic operation principles of direct and indirect evaporative cooling and defines the effectiveness of the systems. Afterwards, it presents three methods that allows to determinate where the systems are more efficient. It concludes that evaporative cooling systems have a very large potential to propitiate thermal comfort and can still be used as an alternative to conventional systems in regions where the design wet bulb temperature is under 24ºC.

José Rui Camargo

2008-01-01

362

COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS  

International Nuclear Information System (INIS)

This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes 'Best Technology Available' for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant's steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R and D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

2010-01-01

363

Materials for advanced water cooled reactors  

International Nuclear Information System (INIS)

[en] The current IAEA programme in advanced nuclear power technology promotes technical information exchange between Member States with major development programmes. The International Working Group on Advanced Technologies for Water Cooled Reactors recommended to organize a Technical Committee Meeting for the purpose of providing an international forum for technical specialists to review and discuss aspects regarding development trends in material application for advanced water cooled reactors. The experience gained from the operation of current water cooled reactors, and results from related research and development programmes, should be the basis for future improvements of material properties and applications. This meeting enabled specialists to exchange knowledge about structural materials application in the nuclear island for the next generation of nuclear power plants. Refs, figs, tabs

1992-01-01

364

Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand  

Energy Technology Data Exchange (ETDEWEB)

The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

Sarkar, C.K.; Pandit, D.R. [Parsons Infrastructure and Technology Group, Boston, MA (United States); Kwon, S.G. [Kolon Engineering and Construction Co., Ltd., Seoul (Korea, Republic of)

1998-12-31

365

Seismic analysis of two 1050 mm diameter heavy water upgrading towers for 235 MWe Kaiga Atomic Power Plant Site  

International Nuclear Information System (INIS)

This report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in two 1050 mm diameter heavy water upgrading towers for Kaiga Atomic Power Plant Site. The analysis of upgrading tower has been carried out for two mutually perpendicular horizontal excitations and one vertical excitation applied simultaneously. The upgrading towers have been analysed using beam model taking into account soil-structure interaction. Response spectrum analysis has been carried out using site spectra for 235 MWe Kaiga reactor site. The seismic analysis has been performed for both the towers with supporting structure along with concrete pedestals and raft foundation. The towers have been checked for its stability due to compressive stresses to avoid buckling so that the nearby safety related structures are not geopardised in the event of safe shutdown earthquake (SSE) loading. (author). 14 refs., 12 figs., 18 tabs.

1992-01-01

366

Seismic analysis of two 1050 mm diameter heavy water upgrading towers for 235 MWe Kakrapar Atomic Power Plant Site  

International Nuclear Information System (INIS)

This report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in two 1050 mm diameter heavy water upgrading towers for Kakrapar Atomic Power Plant Site. The analysis of upgrading tower has been carried out for two mutually perpendicular horizontal excitations and the vertical excitation. The upgrading towers have been analysed using beam model taking into account soil-structure interaction. response spectrum analysis has been carried out using site spectra for 235 MWe KAPP site. The seismic analysis has been carried out for both the towers with supporting structure along with concrete pedestals and raft foundation. The towers have been checked for their stability due to compressive stresses to avoid buckling so that the nearby safety related structures are not damaged in the event of SSE loading. (author). 13 refs., 11 figs., 14 tabs.

1991-01-01

367

Seismic analysis of two heavy water upgrading towers for 500 MWe Tarapur Atomic Power Plant-3 and 4  

International Nuclear Information System (INIS)

The report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in two 1500 mm diameter heavy water upgrading towers for Tarapur Atomic Power Plant-3 and -4. The analysis of upgrading towers has been carried out for two mutually perpendicular horizontal excitations and one vertical excitation applied simultaneously. The upgrading towers have been analysed using beam model taking into account soil-structure interaction. Response spectrum analysis has been carried out using envelope spectra for 500 MWe sites. The seismic analysis has been carried out for the towers with supporting structure along with concrete pedestals and raft foundation. The towers have been checked for their stability due to compressive stresses to avoid buckling so that safety of the nearby structures is not damaged even in the event of SSE (Safe Shutdown Earthquake) loading. (author). 16 refs., 11 figs., 18 tabs

1993-01-01

368

Simulación de una Torre de Enfriamiento Mecánica Comparada con Curvas Experimentales Simulation of a Mechanical Cooling Tower Compared with Experimental Curves  

Directory of Open Access Journals (Sweden)

Full Text Available El objetivo del trabajo es modelar y simular una torre de enfriamiento mecánica forzada a escala piloto. Las variables físicas se correlacionaron a partir de la transferencia de calor y materia y los resultados de la simulación son analizados mediante graficas que muestran la variación de la humedad, flujo de agua, calor latente, calor sensible, calor total, temperatura del agua y del aire. El coeficiente de transferencia de materia se obtuvo a partir de los datos experimentales y la solución numérica del modelo se obtuvo con el método Runge-Kutta en Matlab. La verificación de los resultados fue realizada, comparando las curvas simuladas con las curvas experimentales. Se concluye que la cercanía entre las curvas depende del coeficiente de transferencia de materia.The objective of this work was the modeling and simulation of a pilot-scale mechanical enforced cooling tower. The physical variables were correlated from the heat and mass transfer and the simulation results were analyzed using graphs showing the change in humidity, water flow, latent heat, heat sensitive, total heat, water temperature and air. The mass transfer coefficient was obtained from experimental data and the numerical solution of the model was obtained using Runge-Kutta method in Matlab. Comparison between stimulation results and experimental data was done. It is concluded that the shape of the curves and the deviations of the simulated results depend on the mass transfer coefficient.

Jader D Alean; Gail A Gutiérrez; Farid Chejne; Marlon J Bastidas

2009-01-01

369

Simulación de una Torre de Enfriamiento Mecánica Comparada con Curvas Experimentales/ Simulation of a Mechanical Cooling Tower Compared with Experimental Curves  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El objetivo del trabajo es modelar y simular una torre de enfriamiento mecánica forzada a escala piloto. Las variables físicas se correlacionaron a partir de la transferencia de calor y materia y los resultados de la simulación son analizados mediante graficas que muestran la variación de la humedad, flujo de agua, calor latente, calor sensible, calor total, temperatura del agua y del aire. El coeficiente de transferencia de materia se obtuvo a partir de los datos exp (more) erimentales y la solución numérica del modelo se obtuvo con el método Runge-Kutta en Matlab. La verificación de los resultados fue realizada, comparando las curvas simuladas con las curvas experimentales. Se concluye que la cercanía entre las curvas depende del coeficiente de transferencia de materia. Abstract in english The objective of this work was the modeling and simulation of a pilot-scale mechanical enforced cooling tower. The physical variables were correlated from the heat and mass transfer and the simulation results were analyzed using graphs showing the change in humidity, water flow, latent heat, heat sensitive, total heat, water temperature and air. The mass transfer coefficient was obtained from experimental data and the numerical solution of the model was obtained using Run (more) ge-Kutta method in Matlab. Comparison between stimulation results and experimental data was done. It is concluded that the shape of the curves and the deviations of the simulated results depend on the mass transfer coefficient.

Alean, Jader D; Gutiérrez, Gail A; Chejne, Farid; Bastidas, Marlon J

2009-01-01

370

Organohalogen products from chlorination of cooling water at nuclear power stations  

Energy Technology Data Exchange (ETDEWEB)

Eight nuclear power units at seven locations in the US were studied to determine the effects of chlorine, added as a biocide, on the composition of cooling water discharge. Water, sediment and biota samples from the sites were analyzed for total organic halogen and for a variety of organohalogen compounds. Haloforms were discharged from all plants studied, at concentrations of a few ..mu..g/L (parts-per-billion). Evidence was obtained that power plants with cooling towers discharge a significant portion of the haloforms formed during chlorination to the atmosphere. A complex mixture of halogenated phenols was found in the cooling water discharges of the power units. Cooling towers can act to concentrate halogenated phenols to levels approaching those of the haloforms. Examination of samples by capillary gas chromatography/mass spectrometry did not result in identification of any significant concentrations of lipophilic base-neutral compounds that could be shown to be formed by the chlorination process. Total concentrations of lipophilic (Bioabsorbable) and volatile organohalogen material discharged ranged from about 2 to 4 ..mu..g/L. Analysis of sediment samples for organohalogen material suggests that certain chlorination products may accumulate in sediments, although no tissue bioaccumulation could be demonstrated from analysis of a limited number of samples. 58 references, 25 figures, 31 tables.

Bean, R.M.

1983-10-01

371

Thermohydraulic relationships for advanced water cooled reactors  

International Nuclear Information System (INIS)

This report was prepared in the context of the IAEA's Co-ordinated Research Project (CRP) on Thermohydraulic Relationships for Advanced Water Cooled Reactors, which was started in 1995 with the overall goal of promoting information exchange and co-operation in establishing a consistent set of thermohydraulic relationships which are appropriate for use in analyzing the performance and safety of advanced water cooled reactors. For advanced water cooled reactors, some key thermohydraulic phenomena are critical heat flux (CHF) and post CHF heat transfer, pressure drop under low flow and low pressure conditions, flow and heat transport by natural circulation, condensation of steam in the presence of non-condensables, thermal stratification and mixing in large pools, gravity driven reflooding, and potential flow instabilities. The objectives of the CRP are (1) to systematically list the requirements for thermohydraulic relationships in support of advanced water cooled reactors during normal and accident conditions, and provide details of their database where possible and (2) to recommend and document a consistent set of thermohydraulic relationships for selected thermohydraulic phenomena such as CHF and post-CHF heat transfer, pressure drop, and passive cooling for advanced water cooled reactors. Chapter 1 provides a brief discussion of the background for this CRP, the CRP objectives and lists the participating institutes. Chapter 2 provides a summary of important and relevant thermohydraulic phenomena for advanced water cooled reactors on the basis of previous work by the international community. Chapter 3 provides details of the database for critical heat flux, and recommends a prediction method which has been established through international co-operation and assessed within this CRP. Chapter 4 provides details of the database for film boiling heat transfer, and presents three methods for predicting film boiling heat transfer coefficients developed by institutes participating in this CRP. Chapter 5 compiles a range of pressure drop correlations, and reviews assessments of these relations and the resulting recommendations. Chapter 6 provides general remarks and conclusions, and comments on future research needs in thermohydraulics of advanced water cooled reactors.

2001-01-01

372

Laboratory observations of biocide efficiency against Legionella in model cooling tower systems  

Energy Technology Data Exchange (ETDEWEB)

The efficacy of specific oxidizing and non-oxidizing biocides was examined using a model cooling system inoculated with a microcosm containing an environmental isolate of Legionella pneumophila. The microcosm was prepared in a two-stage chemostat, which provided a consistent source of microbiological inoculum for the study. The microcosm consisted of both sessile (within biofilms) and planktonic Legionella in association with other microorganisms, including Pseudomonas species and cyst-forming ameobae. A procedure was established to successfully transfer the chemostat grown inoculum to the model cooling system and establish both sessile and planktonic forms of Legionella in the model cooling system. The greatest biocidal effect for all of the biocides was observed immediately after dosing. This effect was relatively short-lived even for the slow acting biocides such isothiazolin (as 8 ppm active) where an effect was only observed over the first 12 hours. The faster acting biocides, DBNPA (as 8 ppm active) and gluteraldehyde (as 27 ppm active), did initially reduce Legionella populations but did not totally eliminate Legionella or provide lasting control. Chlorine and bromine (as 0.5--1.5 ppm free halogen), and ozone (as 0.1--0.5 ppm free reserve) reduced and controlled Legionella populations so long as a free reserve of oxidant was maintained. Legionella recovered quickly after biocide dosing, reestablishing similar levels to those observed before dosing.

Thomas, W.M.; Eccles, J.; Fricker, C.

1999-07-01

373

Conscientious control of water treatment keeps heating and cooling systems maintenance-free  

Energy Technology Data Exchange (ETDEWEB)

Prevention of scale and inhibition of corrosion in heating and cooling systems are essential in keeping these systems operating efficiently and maintenance-free. Providing full explanation of the roles of the different water treatment methods and chemicals to operating personnel has proved most important in accomplishing these goals. Various case histories are described in which correction of serious scale and corrosion problems have been experienced and corrected. Experiences are described in supervising the water treatment in some 150 institutions housing residents populations of 10 to 35000. The economics of applying proper and adequately controlled water treatment chemicals is discussed. Methods of treatment of domestic hot water and water used in boilers, cooling towers and closed systems are briefly discussed.

Lane, R.W. [Water Treatment Consultant, Champain, IL (United States)

1995-09-01

374

Coolant technology of water cooled reactors. V. 1: Chemistry of primary coolant in water cooled reactors  

International Nuclear Information System (INIS)

[en] This report is a summary of the work performed within the framework of the Coordinated Research Programme on Investigations on Water Chemistry Control and Coolant Interaction with Fuel and Primary Circuit Materials in Water Cooled Power Reactors organized by the IAEA and carried out from 1987 to 1991. It is the continuation of a programme entitled Reactor Water Chemistry Relevant to Coolant-Cladding Interaction (IAEA-TECDOC-429), which ran from 1981 to 1986. Subsequent meetings resulted in the title of the programme being changed to Coolant Technology of Water Cooled Reactors. The results of this Coordinated Research Programme are published in four volumes with an overview in the Technical Reports Series. The titles of the volumes are: Volume 1: Chemistry of Primary Coolant in Water Cooled Reactors; Volume 2: Corrosion in the Primary Coolant Systems of Water Cooled Reactors; Volume 3: Activity Transport Mechanisms in Water Cooled Reactors; Volume 4: Decontamination of Water Cooled Reactors. These publications should be of interest to experts in water chemistry at nuclear power plants, experts in engineering, fuel designers, research and development institutes active in the field and to consultants to these organizations. Refs, figs and tabs

1992-01-01

375

Economic assessment of the integration of a solar tower to the Aruban water/electric facility  

Energy Technology Data Exchange (ETDEWEB)

The costs for the conversion of an oil burning plant to a hybrid system through the addition of a solar power tower are presented and compared with the cost savings made through reduced fuel consumption. The plant, located on the Island of Aruba, currently produces the island's water through desalination and its electricity through conventional generation. Because of the Aruban climate, it seems reasonable to attempt to use solar energy to reduce the level of oil usage. While the solar hybrid is capital and land intensive, analysis indicates that fuel consumption can be reduced by 5% at an annual savings of $1.8 million (1982 prices). With low interest loans available from the European Community, the capital investment can be paid back in 12 years; estimated life of the solar tower is 30 years.

Savilonis, B.; Buckley, R.; Every, R.

1983-11-01

376

Apparatus provided with a water cooling circuit  

International Nuclear Information System (INIS)

Apparatus, especially an X-ray spectrometer, is provided with a cooling water circuit which is closable by a valve to a pressure water supply on one side and on the other side to an outlet, and through which driven water flows for the purposes of cooling the unit components, such as an X-ray tube, in which circuit a water flow meter is present in the form of a spring-loaded movable plunger, attached to a permanent magnet, wherein the permanent magnet works in conjunction with a tongue contact (= Reed switch), which is connected into the electrical circuit, characterised in that around the contact is wound an electrical coil which may be loaded by the opening of the inlet valve. (G.C.)

1980-01-01

377

Analysis of water cooled reactors stability  

International Nuclear Information System (INIS)

A model for stability analysis of non-boiling water cooled nuclear system is developed. The model is based on linear reactor kinetics and space averaged heat transfer in reactor and heat-exchanger. The transfer functions are defined and the analysis was applied to nuclear reactor RA at 'Boris Kidric' Institute - Vinca. (author)

1980-01-01

378

Lifelines Episode 23: Cool Water  

Science.gov (United States)

This is a free audio podcast from the American Physiological Society. Discussion questions, related research, and other teaching resources are available by clicking on the "collection" tab in the left hand column. Three physiologists tell us why the prescription ÃÂdrink when you are thirstyÃÂ is usually the best guideline for deciding when and how much to drink. We will talk to Heinz Valtin of Dartmouth Medical School (retired); Mark Knepper, the chief of the Laboratory of Kidney & Electrolyte Metabolism of the National Heart Lung and Blood Institute; and Samuel Cheuvront, of the Thermal and Mountain Medicine Division of the U.S. Army Research Institute of Environmental Medicine about water consumption. They will answer the question: ÃÂMust I drink 64 ounces of water each day?ÃÂ (Begins at 3:47) To read the review of the eight-by-eight rule by Heinz Valtin, click here: In the Buzz in Physiology, we look at studies involving a prosthetic device known as the Cheetah Flex Foot and whether it gives a runner who is a bilateral amputee an unfair advantage over limb-intact runners. We also summarize a study in mice in which adult bone marrow stem cells were used as a non-invasive therapy to repair cardiac tissue. And finally, weÃÂll look at a study that finds that electro-acupuncture successfully reduced sympathetic nerve activity, normalized menstrual cycles and reduced testosterone in women with polycystic ovarian syndrome. (Begins at 1:05)

APS Communications Office (American Physiological Society Communications Office); MD Heinz Valtin (Physiology Dartmouth Medical School); Mark Knepper (National Heart Lung and Blood Institute); Samuel Cheuvront (U.S. Army Research Institute of Environmental Medicine)

2009-07-07

379

MHD/gas turbine systems designed for low cooling water requirements  

International Nuclear Information System (INIS)

The MHD/gas turbine combined-cycle system has been designed specifically for applications where the availability of cooling water is very limited. The base case systems which were studied consist of a coal-fired MHD plant with an air turbine bottoming plant and require no cooling water. In addition to the base case systems, systems were considered which included the addition of a vapor cycle bottoming plant to improve the thermal efficiency. These systems require a small amount of cooling water. The results show that the MHD/gas turbine systems have very good thermal and economic performances. The base case I MHD/gas turbine system (782 MW /SUB e/ ) requires no cooling water, has a heat rate which is 13% higher, and a cost of electricity which is only 7% higher than a comparable MHD/steam system (878 MW /SUB e/ ) having a cooling tower heat load of 720 MW. The case I vapor cycle bottomed systems have thermal and economic performances which approach and even exceed those of the MHD/steam system, while having substantially lower cooling water requirements. Performances of a second-generation MHD/gas turbine system and an oxygen-enriched, early commercial system are also evaluated. An analysis of nitric oxide emissions shows compliance with emission standards.

1983-01-01

380

Laboratory Experiments with Supersonic Radiatively Cooled Jets: Jet Deflection via Crosswinds and Magnetic Tower Outflows  

International Nuclear Information System (INIS)

We present results of high energy density laboratory experiments on the production of supersonic radiatively cooled plasma jets with dimensionless parameters (Mach number ?30, cooling parameter ?1 and density contrast ?j/?a ?10) similar to those in YSO jets. The jets are produced using two modifications of wire array Z-pinch driven by 1MA, 250ns current pulse of MAGPIE facility at Imperial College London. In the first set of experiments the produced jets are purely hydrodynamic and are used to study deflection of the jets by the plasma cross-wind, including the structure of internal oblique shocks in the jets. In the second configuration the jets are driven by the pressure of the toroidal magnetic field and this configuration is relevant to the astrophysical models of jet launching mechanisms. Modifications of the experimental configuration allowing addition of the poloidal magnetic field and angular momentum to the jets are also discussed. We also present three-dimensional resistive magneto-hydrodynamic (MHD) simulations of the experiments and discuss the scaling of the experiments to the astrophysical systems.

2006-04-07

 
 
 
 
381

Reduction of Langelier index of cooling water by electrolytic treatment with stainless steel electrode  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The efficiency of electrolytic treatment in reducing the Langelier saturation index (LSI) of the cooling water from a cooling tower of a textile industry was investigated. Sacrificial anodes were employed which prevent obnoxious chlorine generation. A series of batch experiments using stainless steel electrodes were conducted with 4 different current densities (5, 7, 10 and 15 A/m²) and 6 different electrolysis times (20, 30, 40, 50, 60 and 70 min). The use of 7 A/m² fo (more) r 50 min electrolysis time yielded a satisfactory efficiency in reducing the LSI index from 2.57 to zero, indicating that the treated water was of sufficient quality to be reused in the cooling process.

Rungvavmanee, Rapeepat; Phalakornkule, Chantaraporn

2012-01-01

382

Natural-draught wet-type cooling tower of the Philippsburg 1 nuclear power plant. Naturzug-Nasskuehlturm des Kernkraftwerkes Philippsburg (Block 1)  

Energy Technology Data Exchange (ETDEWEB)

In spring 1980, comprehensive field measurements were performed on the natural-draught wet type, cooling tower of Philippsburg I nuclear power plant. Performance in service and emission of cooling tower, condition of ambient atmosphere and spread of plume were studied in seven subprojects. The report on hand contains the results of the 8th subproject within which plume spreading was calculated by means of mathematical models. Efforts were made to win the participation of as large as circle of scientists as possible in order to obtain an overview on the efficiencies of the existing models. The size of visible plumes were calculated by means of emission data and ambient data and were compared with those dimensions resulting from photograph. The models and the results are described in individual reports. Results were summarized for B models. Complete data on the 16 Philippsburg incidents are contained in the annex to the program report.

Ernst, G.; Schnabel, G.; Bhargava, N.; Brog, P.; Caneill, J.Y.; Carhart, R.A.; Dorwarth, G.; Egler, W.; Fiedler, F.; Gassmann, F.

1984-01-01

383

Use of Produced Water in Recirculating Cooling Systems at Power Generating Facilities  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. This deliverable describes possible test configurations for produced water demonstration projects at SJGS. The ability to host demonstration projects would enable the testing and advancement of promising produced water treatment technologies. Testing is described for two scenarios: Scenario 1--PNM builds a produced water treatment system at SJGS and incorporates planned and future demonstration projects into the design of the system. Scenario 2--PNM forestalls or decides not to install a produced water treatment system and would either conduct limited testing at SJGS (produced water would have to be delivered by tanker trucked) or at a salt water disposal facility (SWD). Each scenario would accommodate demonstration projects differently and these differences are discussed in this deliverable. PNM will host a demonstration test of water-conserving cooling technology--Wet Surface Air Cooling (WSAC) using cooling tower blowdown from the existing SJGS Unit 3 tower--during the summer months of 2005. If successful, there may be follow-on testing using produced water. WSAC is discussed in this deliverable. Recall that Deliverable 4, Emerging Technology Testing, describes the pilot testing conducted at a salt water disposal facility (SWD) by the CeraMem Corporation. This filtration technology could be a candidate for future demonstration testing and is also discussed in this deliverable.

Kent Zammit; Michael N. DiFilippo

2005-07-01

384

Mixing systems for wet and dry plumes and cleaning equipment for the heat exchangers of the dry section. Two indispensible components of an effective and safe hybrid cooling tower  

International Nuclear Information System (INIS)

At first glance, the hybrid cooling tower seems to be an ingenious combination of the well known components of an evaporative cooling tower and a dry cooling tower. The calculation of the air mass flows for both the wet and dry sections required to achieve an invisible plume does not represent an unsolvable problem to the engineer experienced in thermodynamics. The same also applies to the dimensioning of the heat exchangers and cooling fills. The hybrid cooling tower requires a well designed mixing system in order to ideally mix, the dry plume into the wet plume. If the cooling tower proves its efficiency during commissioning it is important that the ratio of the performance of the wet section to that of the dry section be maintained also in the long term. The performance of the fill in a wet cooling tower is consistently stable. Dirt deposits can form very quickly on the inner and outer surfaces of the heat exchangers of the dry section. In this case the thermal resistance increases rapidly. The respective performance of the wet and dry sections is then no longer balanced and the invisibility of the plume is no longer assured. This can be avoided by providing appropriate cleaning equipment

1990-06-02

385

Consideration of wind tunnel studies in dispersion calculations with the new model Austal2000-case study: discharge of flue gas via cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The Technical Instructions on Air Quality Control (German abbrev.: TA Luft) serves the protection of the public and the neighborhood against harmful environmental effects in general and particularly against harmful air pollution. This guideline has to be considered at installing and operating plants requiring a permission. This regulatory guideline was adapted in 2002 to the progressed state-of-the-art and to the new legislation of the European Community. In this context the calculation method to derive the air pollution load caused by plants under the permission act was also updated. Instead of a Gaussian model the more sophisticated particle model AUSTAL2000 (Janicke, L., 2003) of Langrangian type is used in the frame of permission procedures. It was developed on behalf of the German Federal Environmental Agency. The dispersion model AUSTAL2000 comprises for cases with flue gas discharge via cooling tower the special water vapour plume rise approach of the VDI guideline 3784/2. But there is no procedure defined to consider in those cases the effects of buildings on the dispersion characteristics. A frequently used investigative method to gain information on how buildings influence the dispersion regime in the surroundings of a plant is the execution of experiments in a boundary layer wind tunnel. (orig.)

Bahmann, W.; Schmonsees, N. [ArguMet Consultants, Mechernich and Borgwedel (Germany)

2004-07-01

386

Water cooled FBNR nuclear reactor  

International Nuclear Information System (INIS)

Full text: The world with its increasing population and the desire for a more equitable and higher standard of living, is in the search for energy that is abundant and does not contribute to the problem of global warming. The answer to this is a new paradigm in nuclear energy; i.e., through the innovative nuclear reactors that meet the IAEA's INPRO philosophies and criteria that will guarantee the generation of safe and clean energy. The emerging countries to nuclear energy that are not in hurry for energy and look into the future are looking into the participation in the development of such innovative nuclear reactors. They can start developing the non-nuclear components of such reactors in parallel with creating the nuclear infra-structures according to the guidelines of the IAEA suggested in its milestones document. In this way, they can benefit from numerous advantages that the development of a high technology can bring to their countries be it scientific, technological, economic or political. A solution to the present world economic crisis is investing in such projects that contribute to the real economy rather than speculative economy. This will help both local and world economy. One such innovative nuclear reactor is the FBNR that is being developed with the support of the IAEA in its program of Small Reactors Without On-site Refuelling. It is a small (70 MWe) reactor with simple design based on the proven PWR technology (www.sefidvash.net/fbnr). The simplicity in design and the world wide existence of water reactor technology, makes it a near term project compared to other future reactors. Small reactors are most adequate for both the developing and developed countries. They require low capital investment, and can be deployed gradually as energy demand calls for. The generation of energy at the local of consumption avoids high cost of energy transmission. The paradigm of economy of scale does not apply to the FBNR as it is a small reactor by its nature. The FBNR enjoys the economy of mass production. FBNR can serve a dual purpose plant generating electricity and producing desalinated water at the same time at lower cost. The FBNR has been evaluated by the IAEA's INPRO Methodology from the safety and nonproliferation points of view and is shown to be a fool proof reactor against nuclear proliferation and have inherent safety against any conceivable accident. The reactor has in its upper part the reactor core and a steam generator and in its lower part the fuel chamber. The core consists of two concentric perforated zircaloy tubes of 31 cm and 171 cm in diameters, inside which, during the reactor operation, the spherical fuel elements are held together by the coolant flow in a fixed bed configuration, forming a suspended fixed core. The coolant flows vertically up into the inner perforated tube and then, passing horizontally through the fuel elements and the outer perforated tube, enters the outer shell where it flows up vertically to the steam generator. The reserve fuel chamber is a 60 cm diameter tube made of high neutron absorbing alloy, which is directly connected underneath the core tube. The fuel chamber consists of a helical 40 cm diameter tube flanged to the reserve fuel chamber that is sealed by the national and international authorities. A grid is provided at the lower part of the tube to hold the fuel elements within it. A steam generator of the shell-and-tube type is integrated in the upper part of the module. A control rod can slide inside the centre of the core for fine reactivity adjustments. The reactor is provided with a pressurizer system to keep the coolant at a constant pressure. The pump circulates the coolant inside the reactor moving it up through the fuel chamber, the core, and the steam generator. Thereafter, the coolant flows back down to the pump through the concentric annular passage. At a flow velocity called terminal velocity, the water coolant carries the 15 mm diameter spherical fuel elements from the fuel chamber up into the core. A fixed suspended core is formed in the reactor. In

2009-01-01

387

Cooling tower restoration in the joint nuclear power station Neckar 1; Kuehlturmsanierung im Gemeinschaftskernkraftwerk Neckar 1  

Energy Technology Data Exchange (ETDEWEB)

Since the starting operation of the Power Station GKN I (Joint Nuclear Power Station Neckar I) in the year 1976, the cell cooler of the plant was, except for those cases in which continuous-flow cooling was possible, continually in operation. Aim of the restoration, after an operational time of 17 years, is a further constructional and thermal service life of about 15 to 20 years. (orig.) [Deutsch] Seit der Inbetriebnahme des Kraftwerkes GKN I im Jahr 1976 war der Zellenkuehler der Anlage bis auf die Faelle, in denen Durchlaufkuehlung moeglich war, ununterbrochen in Betrieb. Ziel der Sanierung nach ueber 17jaehriger Betriebszeit ist eine weitere bauliche und thermische Nutzungsdauer von etwa 15 bis 20 Jahren. (orig.)

Ernst, G. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Technische Thermodynamik; Braeuning, G. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Technische Thermodynamik; Dekker, G. [Marley Kuehlturm GmbH, Duesseldorf (Germany). Bereich Vertrieb neuer Kuhlturm-Anlagen

1996-11-01

388

Dechlorination of waste water and cooling water  

Energy Technology Data Exchange (ETDEWEB)

The movement toward dechlorination is propelled by a desire to escape the environmental problems associated with both the residual oxidants and halocarbons produced by chlorination. The chemistry of dechlorination is reviewed with the purpose of showing that questions remain about the environmental effects of the general use of dechlorination. Comparisons of the toxicity of chlorinated vs. chlor-dechlorinated water show that dechlorination reduces acute toxicity to aquatic organisms, but sublethal biological effects were noted in chlor-dechlorinated waters and in waters treated only with dechlorinating agents. Types of dechlorinating agents are discussed with special emphasis on the sulfur containing compounds. It is of considerable importance that dechlorinating with S(IV) compounds in the effluent. The formation of sulfonates during dechlorination is discussed, as well as the prevention of halocarbons. The effect of dechlorination on downstream trace-metal chemistry is related.

Helz, G.R.; Kosak-Channing, L.

1984-02-01

389

Power plant cooling systems: policy alternatives.  

UK PubMed Central (United Kingdom)

Policies and pressures emanating from the 1972 Amendments to the Federal Water Pollution Control Act favor the installation of cooling towers, or closedcycle cooling systems, in power plants. An assessment of the relative risks of alternative cooling system designs indicates that, in general, adverse environmental effects associated with cooling towers are more certain, are of larger scale, and are more likely to be irreversible than impacts associated with once-through cooling systems and cooling reservoirs. Adverse environmental effects associated with once-through cooling and cooling reservoirs are largely amenable to mitigation in the context of resource management principles. These factors, together with the greater costs associated with cooling towers, indicate that wherever the feasibility is demonstrated and there is minimal risk to aquatic ecosystems, once-through cooling systems or cooling reservoirs should be preferred.

Reynolds JZ

1980-01-01

390

Operation of cooling towers at high cycles of concentration: Corrosion and scale control  

Energy Technology Data Exchange (ETDEWEB)

Unique chemistry is developed which allows conservation of water through increased cycles. This chemistry permits control of calcium carbonate up to and exceeding 300 times saturation. This paper will discuss the superior corrosion inhibition properties under these conditions and the properties that afford good protection. Corrosion inhibition studies using weight loss, electrochemical tests and surface analysis show that PAPEMP allows a very effective invisible cathodic barrier to form which incorporates calcium carbonate. The significant property of the inhibitor that differentiates performance and allows it to work under these conditions is its extreme calcium tolerance.

Cognetti, A.; Parsons, J.; Geraghty, M.; Vanderpool, D. [Calgon Corp., Pittsburgh, PA (United States)

1996-10-01

391

First application of MOL {sup registered} CLEAN - process in a cooling tower of an oil refinery; Erstmalige Anwendung des MOL {sup registered} CLEAN - Verfahrens in einem Kuehlkreislauf einer Erdoelraffinerie  

Energy Technology Data Exchange (ETDEWEB)

Biological loads of cooling cycles in oil refineries can cause efficiency losses. The key components of biological loads are bio layers. With the help of the MOL {sup registered} CLEAN process, these bio layers are sustainably eliminated. This technique was installed in a cooling tower battery of the BAYERNOIL Raffineriegesellschaft mbH in Neustadt on the Danube river in October 2004. After installation, all bio layers were eliminated from the sprinkled packages of cooling tower and from the heat exchangers surfaces without any unwelcome side effects. In this way, the performance of the cooling cycle was enhanced with positive consequences on the global refinery efficiency. (orig.)

Ernhofer, R.; Karl, G.; Wentzlau, F. [BAYERNOIL Raffineriegesellschaft mbH, Ingolstadt (Germany); Koppe, J.; Lausch, H. [MOL Katalysatortechnik GmbH, Merseburg (Germany)

2005-10-01

392

Presence of pathogenic microorganisms in power-plant cooling waters. Final report, October 1, 1981-June 30, 1983  

Energy Technology Data Exchange (ETDEWEB)

Air was sampled at the point of discharge and at short distances downwind and upwind from industrial and power-plant cooling towers. Both high-volume electrostatic and impinger type samplers were used. Concentrates of the air samples were analyzed for Legionnaires' Disease Bacteria (LDB). In some cases, the samples were also tested for the presence of free-living amoebae. The concentrations of LDB in the air samples were well below the minimal infectious dose for guinea pigs and precluded testing of the samples for infectious LDB. Results of LDB analysis were related to the meteorological conditions at the time of sampling. Generally, the concentrations of LDB in the air at the discharge of the cooling towers were 1 x 10/sup -6/ to 1 x 10/sup -7/ of that found in comparable volumes of tower basin water. During periods of high humidity and wind speed, LDB was detected in a few downwind samples and one upwind sample. One site with extensive construction and excavation activity had higher LDB concentrations in air samples relative to other sites. Nonpathogenic Naegleria were present in one of two air samples taken in the mist at the base of a natural-draft cooling tower.

Tyndall, R.L.

1983-07-01

393

Bacterial community structure in cooling water and biofilm in an industrial recirculating cooling water system.  

UK PubMed Central (United Kingdom)

Microbial fouling is a serious problem in open recirculating cooling water systems. The bacterial communities that cause it have not been fully understood. In this study, we analyzed the community structure of free-living bacteria and particle-attached bacteria in cooling water, and bacteria in biofilm collected from the wall of the water reservoir in an industrial recirculating cooling water system by construction of a 16S rRNA gene clone library. Based on amplified ribosomal DNA restriction analysis, clones of all three libraries were clustered into 45 operational taxonomic units (OTUs). Thirteen OTUs displaying 91-96% sequence similarity to a type strain might be novel bacterial species. Noted differences in community structure were observed among the three libraries. The relative species richness of the free-living bacteria in cooling water was much lower than that of particle-attached bacteria and bacteria in biofilm. The majority of the free-living bacterial