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1

Hot-water cooling tower  

International Nuclear Information System (INIS)

The covering of a cooling tower as suggested prevents the escape of steam possibly mixed with other components into the environment, thus preventing the possibility of smog formation. From the cap sealing the cooling tower on its upper side, the steam is sucked off by an external jacket-cooled pipe line by means of a ventilator. The ventilator lies in a bypass of the pipeline, thus keeping condensates developed away from the ventilator. The condensate reaches the draintank in the footing of the cooling tower through the pipeline. This drain tank also takes up the condensate developing directly in the tower. (HP)

1975-01-01

2

Asbestos in cooling-tower waters  

Energy Technology Data Exchange (ETDEWEB)

Fill material in natural- or mechanical-draft cooling towers can be manufactured from a variety of materials, including asbestos cement or asbestos paper. To aid in the environmental impact assessment of cooling towers containing these asbestos types of fill, information on these materials was obtained from cooling-tower vendors and users. Samples of makeup, basin, and blowdown waters at a number of operating cooling towers were obtained, and identification and enumeration of asbestos in the samples were performed by transmission electron microscopy, selected-area electron diffraction, and energy-dispersive x-ray analysis. Asbestos fibers were detected in cooling-tower water at 10 of the 18 sites sampled in the study. At all but three sites, the fibers were detected in cooling-tower basin or blowdown samples, with no fibers detected in the makeup water. The fibers were identified as chrysotile at all sites except one. Concentrations were on the order of 10/sup 6/ to 10/sup 8/ fibers/liter of water, with mass concentrations between <0.1 ..mu..g/liter to 37 ..mu..g/liter. The maximum concentrations of asbestos fibers in air near ground due to drift from cooling towers were estimated (using models) to be on the order of asbestos concentrations reported for ambient air up to distances of 4 km downwind of the towers. The human health hazard due to abestos in drinking-water supplies is not clear. Based on current information, the concentrations of asbestos in natural waters after mixing with cooling-tower blowdown containing 10/sup 6/ to 10/sup 8/ fibers/liter will pose little health risk. These conclusions may need to be revised if future epidemiological studies so indicate.

Lewis, B.A.G.

1977-12-01

3

Asbestos in cooling-tower waters. Final report  

International Nuclear Information System (INIS)

Water discharges from cooling towers constructed with asbestos fill were found to contain chrysotile--asbestos fibers at concentrations as high as 108 fibers/liter. The major source of these fibers, appears to be the components of the towers rather than the air drawn through the towers or the makeup water taken into the towers. Suggested mechanisms for the release of chrysotile fibers from cooling-tower fill include freeze-thaw cycles and dissolution of the cement due to acidic components of the circulating water. Ash- or other material-settling ponds were found to reduce asbestos-fiber concentrations in cooling-tower effluent. The literature reviewed did not support the case for a causal relationship between adverse human health effects and drinking water containing on the order of 106 chrysotile--asbestos fibers/liter; for this and other reasons, it is not presently suggested that the use of asbestos fill be discontinued. However, caution and surveillance are dictated by the uncertainties in the epidemiological studies, the absence of evidence for a safe threshold concentration in water, and the conclusive evidence for adverse effects from occupational exposure. It is recommended that monitoring programs be carried out at sites where asbestos fill is used; data from such programs can be used to determine whether any mitigative measures should be taken. On the basis of estimates made in this study, monitoring for asbestos in drift from cooling towers does not appear to be warranted

1979-01-01

4

Performance of water distribution systems in a pilot cooling tower  

International Nuclear Information System (INIS)

An experimental study has been carried out on the water distribution system of a Pilot cooling tower of 160 m3/hr The performances of different industrial water distributors have been evaluated by changing the operative conditions of the pilot tower. In particular, the efficiency and the uniformity of the water distribution have been investigated and compared with the results obtained in a small-scale loop, in which the single nozzles were tested. Measurements in both systems, pilot tower and small scale loop, included the geometric characteristics of the jet umbrella by ensemble photography, the wetted zone by measuring the specific flowrate, the drop-size distribution and liquid concentration by high-speed photography. The results show that correlations exist between the nozzle behaviour in single and pilot tower configuration. The uniformity of water distribution in the pilot tower is strongly related to the nozzle installation pattern and to the operative conditions. Coalescence plays an important role on the drop size distribution in the pilot-tower. Comments upon the influence of these parameters on tower behaviour are also included

1990-09-01

5

Water distribution in cooling towers: Characterization of industrial spray nozzles  

International Nuclear Information System (INIS)

The distribution of water to the top of counterflow fill of cooling towers is a key aspect of the performance of the whole cooling systems. It is a function of nozzle design, nozzle installation, height of the spray zone, and the structural cleanliness of the spray chamber. The impact of water distribution on performance is a combination of uniformity of water distribution, air-side pressure drops, and heat transfer occurring in the spray zone. As the matter of fact, simulation of cooling tower behavior by means of a two-dimensional code showed that droplet size in the spray zone plays an important role on tower performances. In spite of its practical importance, the water distribution process has not been studied enough. In this work four practical nozzels were studied experimentally and, on the basis of the results, some performers parameters have been defined and evaluated, which can be related to heat transfer and pressure drops in the spray zone of a cooling tower

1989-04-01

6

Computerized engineering model for evaporative water cooling towers  

International Nuclear Information System (INIS)

The evaporative cooling tower is often used to reject waste heat from industrial processes, especially power plants and chemical facilities. A consistent physical model for crossflow and counterflow cooling towers which imposes rigorous heat and mass balances on each increment of the tower under study is presented. Individual towers are characterized by specification of a mass evaporation rate equation. The solution algorithm allows reduction of test data, interpolation of the reduced data, and comparison of test results to design data. These capabilities can be used to evaluate acceptance tests for new towers, to monitor changes in tower performance as an aid in planning maintenance, and to predict tower performance under changed operating conditions

1977-05-11

7

Reducing water consumption of an industrial plant cooling unit using hybrid cooling tower  

International Nuclear Information System (INIS)

Water consumption is an important problem in dry zones and poor water supply areas. For these areas use of a combination of wet and dry cooling towers (hybrid cooling) has been suggested in order to reduce water consumption. In this work, wet and dry sections of a hybrid cooling tower for the estimation of water loss was modeled. A computer code was also written to simulate such hybrid cooling tower. To test the result of this simulation, a pilot hybrid tower containing a wet tower and 12 compact air cooled heat exchangers was designed and constructed. Pilot data were compared with simulation data and a correction factor was added to the simulation. Ensuring that the simulation represents the actual data, it was applied to a real industrial case and the effect of using a dry tower on water loss reduction of this plant cooling unit was investigated. Finally feasibility study was carried out to choose the best operating conditions for the hybrid cooling tower configuration proposed for this cooling unit.

2010-02-01

8

Cooling tower reconstruction  

Energy Technology Data Exchange (ETDEWEB)

At the majority of coking plants the primary gas cooler water cooling cycle uses cooling towers with natural tower draft. The Yasinovka Coke Works installed three such cooling towers with capacity of 1000 m/sup 3//hr of water each with irrigation surface of 1000 m/sup 2/. The water distribution is gravity-flow, unpressurized. The construction of one cooling tower consumes 610 m/sup 3/ of lumber. Operation of the cooling towers for 25 years, even with a significant volume of maintenance, left them completely unserviceable. At some coking plants the cooling towers even collapsed. Using a Giprokoks Institute design, in 1977 the Yasinovka Coke Works built a 3-sectioned tower with forced draft under vacuum, with type 1VG-70 ventilators with capacity of 1500 m/sup 3//hr. The cooling towers had an irrigation surface area of 432 m/sup 2/ and pressurized irrigation devices. The erection of this structure under the conditions of an operating plant was complicated by the necessity of constructing an underground tank and a great deal of precast reinforced concrete was consumed (70 patterns). In order to decrease the capital investment, the Yasinovka Coke Works and the Ukrkoks RPO PKB (Industrial Design Bureau) developed a design using the existing cooling tower tank for installation of forced-draft 3-sectioned cooling tower. (Subsequently, a group of engineers and technicians at the plant proposed the use of the reinforced concrete structure and tank of a cooling tower in the construction of a forced draft cooler).

Sukhov, A.A.; Venzhega, A.G.; Beizer, V.N.; Kovalenko, A.V.

1983-01-01

9

Engineering and economic evaluation of wet/dry cooling towers for water conservation  

International Nuclear Information System (INIS)

The results are presented of a design and cost study for wet/dry tower systems used in conjunction with 1000 MWe nuclear power plants to reject waste heat while conserving water. Design and cost information for wet/dry tower systems are presented, and these cooling system alternatives are compared with wet and dry tower systems to determine whether the wet/dry tower concept is an economically viable alternative. The wet/dry cooling tower concept investigated is one which combines physically separated wet towers and dry towers into an operational unit. In designing the wet/dry tower, a dry cooling tower is sized to carry the plant heat load at low ambient temperatures, and a separate wet tower is added to augment the heat rejection of the dry tower at higher ambient temperatures. These wet/dry towers are designed to operate with a conventional low back pressure turbine commercially available today. The component wet and dry towers are state-of-the-art designs. From this study it was concluded that: wet/dry cooling systems can be designed to provide a significant economic advantage over dry cooling yet closely matching the dry tower's ability to conserve water, a wet/dry system which saves as much as 99 percent of the make-up water required by a wet tower can maintain that economic advantage, and therefore, for power plant sites where water is in short supply, wet/dry cooling is the economic choice over dry cooling

1976-01-01

10

Coagulation chemistries for silica removal from cooling tower water.  

Energy Technology Data Exchange (ETDEWEB)

The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

2010-02-01

11

Complex development of cooling towers  

International Nuclear Information System (INIS)

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

1990-09-01

12

Evaluation of heat exchange performance for the auxiliary component cooling water system cooling tower in HTTR  

International Nuclear Information System (INIS)

The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR). The ACCWS has main two features, many facilities cooling, and heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design. (author)

2006-01-01

13

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

14

The nominal cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95{degrees}F. Hot Water temperature (HWT) Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies through out the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can select the nominal cooling tower model recommended by the manufacturer. Ask any HVAC operator, refinery manager, power generating station operator what happens when the Wet Bulb reaches or exceeds the design WBT of the area. He probably will tell you, {open_quotes}My cooling tower works quite well, but in the summer time, I usually have trouble with it.{close_quotes} This occurs because he is operating a nominal cooling tower.

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

1995-12-31

15

Comparative technical-economical investigation for a counter-flow cooling tower fitted with water collectors  

International Nuclear Information System (INIS)

The paper points out the investigation of a high capacity cooling tower fitted with water collectors, compared with the conventional constructive variant. It is the Romanian concerns with respect to cutting down the cooling tower power consumption that are investigated by means of updated overall expenses method

1990-09-01

16

Plume abatement and water conservation with the wet/dry cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Wet/dry towers, sometimes referred to in Europe as hybrid cooling towers, evolved beginning about 1970 due to concerns regarding the environment. The United States Environmental Protection Agency classified the visible discharge plume from evaporative or wet cooling towers as visual pollution. Tower designs evolved which incorporated readily available air-cooled or dry heat exchangers to introduce a non-evaporative air heating process. The combination of evaporative and non-evaporative heating results in reduction of the relative humidity of the air leaving these wet/dry cooling towers. For a period of time, environmental impact statement requirements required review of the plume abatement option on most large industrial and power sites. A result was construction of some large industrial and power plant sized wet/dry cooling towers for plume abatement. Higher capital cost and operating power consumption than that of wet towers was typical of this generation of wet/dry towers. The higher off-design cold water temperatures of wet-dry towers resulted in higher heat rates and fuel costs for power plants. By the end of the decade, economic influences led to diminished pressure from the EPA. For these reasons, the number of wet/dry towers studied and purchased subsided drastically during the late 1970`s.

Lindahl, P.A. Jr.; Jameson, R.W. [Marley Cooling Tower Co., Mission, KS (United States)

1995-02-01

17

Fouling characteristics of cooling tower water containing corrosion inhibitors  

Energy Technology Data Exchange (ETDEWEB)

Corrosion inhibitors investigated included zinc-chromate and phosphates. In addition, additives including polyacrylate and phosphonate (HEDP and AMP) were used to determine their effectiveness as antifoulants. The tests were conducted in a simulated cooling tower water system. The parameters investigated were: test section surface temperature 130, 145 and 160{degree}F, velocity in test section 3.0, 5.5 and 8.5 ft/sec, pH 6.0 -8.0, and material of the fouling surface (stainless steel, carbon steel, 90/10 copper/nickel, and admiralty brass). The water bulk temperature in all tests was 115{degree}F. The water had a total hardness of 800-1000 ppm as CaCO{sub 3}, total sulfate of 800-1000 ppm as SO{sub 4} and silica of 40-45 ppm as SiO{sub 2}. For each test, a fouling resistance - time curve was obtained. This curve was fitted to the equation Rf = Rf (1-exp(-({theta}-{theta}d)/{theta}c)) to yield the values of {theta}c and Rf{sup *}. Rf is the fouling resistance predicted by the regression equation, Rf{sup *} is the asymptotic fouling resistance, {theta} is time, {theta}d is dead time and {theta}c is the time constant for the asymptotic decay. The values of {theta}c and Rf{sup *} from regression analysis have been correlated with the various parameters by the Heat Transfer Research, Inc., (HTRI) fouling model. For the range of conditions studied, the correlation equations relate the fouling resistance, Rf, to the surface temperature, wall shear stress and water quality. Seventeen different water qualities were investigated to determine the values of 5 parameters, which are specific for each water quality. For each of the seventeen water qualities studied threshold curves for three threshold values of Rf{sup *} have been developed as a function of velocity and surface temperature. These curves are useful to obtain the conditions required to maintain a desired value of Rf{sup *} in a heat exchanger.

Santoso, E.

1987-01-01

18

Cooling towers of electric power generation plants  

International Nuclear Information System (INIS)

After a definition and a presentation of the aim of cooling, this paper deals with the operation principle of the main types of cooling towers. The main types of cooling towers can be classified in two categories: mechanical draft cooling towers and natural draft cooling towers. Equations governing heat transfers in wet or dry cooling towers are presented and applied to some problems such as dimensioning, or evaporated water rate-mass. Finally, criteria to choose a type of cooling tower are briefly given

1984-08-01

19

Cooling tower selection and installation factors  

Energy Technology Data Exchange (ETDEWEB)

Conserving and recycling water in industrial plants cooling towers are discussed. The fundamental principles of a cooling tower are explained by considering a droplet of water inside a cooling tower. The need for correct wet bulb selection for a given re-cooled water temperature in order to choose the proper cooling tower size is discussed. Site considerations, which are mainly dependent on the piping requirements and pump placements, are presented. Benefits of various types of pack and maintenance for cooling towers are discussed. (MCW)

Bristowe, K.

1981-02-01

20

Negative enrichment procedure for isolation of Legionella pneumophila from seeded cooling tower water.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A negative enrichment procedure was developed which was capable of isolating Legionella pneumophila directly from seeded air-conditioning cooling tower water onto laboratory media. This procedure was based on an 8-h incubation under conditions that were bactericidal to the indigenous water microflora but merely bacteriostatic to L. pneumophila.

Thorpe, T. C.; Miller, R. D.

1980-01-01

 
 
 
 
21

Cooling towers: a bibliography  

Energy Technology Data Exchange (ETDEWEB)

This bibliography cites 300 selected references containing information on various aspects of large cooling tower technology, including design, construction, operation, performance, economics, and environmental effects. The towers considered include natural-draft and mechanical-draft types employing wet, dry, or combination wet-dry cooling. A few references deal with alternative cooling methods, principally ponds or spray canals. The citations were compiled for the DOE Energy Information Data Base (EDB) covering the period January to December 1980. The references are to reports from the Department of Energy and its contractors, reports from other government or private organizations, and journal articles, books, conference papers, and monographs from US originators.

Whitson, M.O. (ed.)

1981-02-01

22

Cooling towers: a bibliography  

International Nuclear Information System (INIS)

This bibliography cites 300 selected references containing information on various aspects of large cooling tower technology, including design, construction, operation, performance, economics, and environmental effects. The towers considered include natural-draft and mechanical-draft types employing wet, dry, or combination wet-dry cooling. A few references deal with alternative cooling methods, principally ponds or spray canals. The citations were compiled for the DOE Energy Information Data Base (EDB) covering the period January to December 1980. The references are to reports from the Department of Energy and its contractors, reports from other government or private organizations, and journal articles, books, conference papers, and monographs from US originators

1981-01-01

23

Common misconceptions about cooling towers  

Energy Technology Data Exchange (ETDEWEB)

This article discusses the design and performance of the water cooling tower. In many cases the numbers presented in a cooling tower inquiry for thermal performance design represent a more stringent condition than that found in the operation of the unit. A common misconception is to take the service factor or safety factor in the cold water temperature or the wet bulb temperature. Service factors are used in the preparation of specifications for most industrial equipment. Standards specify a minimum service factor of 2.0 for cooling tower right angle spiral bevel gears. Closing the approach (cold water temperature minus wet bulb temperature) does not vary linearly with increasing difficulty of duty for the cooling tower, and consequently does not represent a straight-line increase in size or cost. A decrease in the specified approach is equivalent to a decrease in the driving force available for the transfer of mass and heat from the water to the air stream. A decrease in approach from 20 to 19/sup 0/F would result in an increase in cost of about 5%, while a decrease from 5 to 4/sup 0/F would require about 20% more cooling tower.

Willa, J.L.; Campbell, J.C.

1983-12-01

24

Determination of fan flow and water rate adjustment for off-design cooling tower tests  

International Nuclear Information System (INIS)

The determination of the performance of a mechanical draft cooling tower requires that the air mass flow through the tower be known. Since this flow is not measured, it has been customary to use the manufacturer's design air flow and adjust it by the one-third power of the ratio of the design to test fan horsepower. The most nearly correct approximation of air flow through a tower can be obtained by incrementally moving through the tower from air inlet to outlet while calculating mass flows, energy balances, and pressure drops for each increment and then utilizing fan curves to determine volumetric and mass flows. This procedure would account for changes in air humidity and density through the tower, evaporation of water, effect of water rate on air pressure drop, and changes in fan characteristics. These type calculations may be within the capabilities of all in the near future, but for the interim, it is recommended that a more elementary approach be used which can be handled with a good calculator and without any proprietary data. This approach depends on certain assumptions which are acceptable if the tower test is conducted within CTI code requirements. The fan must be considered a constant suction volume blower for a given blade pitch. The total pressure at the fan, a function of volumetric flow and wet air density, must be assumed to be unaffected by other considerations, and the fan horsepower must be assumed to change only as volumetric flow and wet air density changes. Given these assumptions, along with design information normally provided with a tower, the determination of air flow through a tower in a test can be made from CTI test data. The air flow, and consequently the water rate adjustment and corrected water to air ratio, are derived and found to be direct functions of horsepower and density and an inverse function of wet air humidities

1984-02-06

25

Cooling tower, particularly natural draught cooling tower. Kuehlturm, insbesondere Naturzugkuehlturm  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is to improve a cooling tower with noise absorbing gates, so that conditions are created in the cooling tower in the simplest way, without any effect on the cooling water circuit, which prevent the formation of dangerous ice deposits in the falling cooling water. According to the invention, this problem is solved by making every second gate movable around its supporting vane, and making the other gates fixed, and by having the movable gates coupled together via a setting drive. This device, according to the invention, has the advantage that the quantities of air passing through can be matched to the outside temperature by adjusting the gates, particularly if the outside air temperature has dropped below a critical value. (HWJ).

Miller, C.W.; Feltes, U.; Schwickert, M.

1985-10-24

26

Self-optimizing Control of Cooling Tower for Efficient Operation of Chilled Water Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The chilled-water systems, mainly consisting of electric chillers and cooling towers, are crucial for the ventilating and air conditioning systems in commercial buildings. Energy efficient operation of such systems is thus important for the energy saving of commercial buildings. This paper presents an extremum seeking control (ESC) scheme for energy efficient operation of the chilled-water system, and presents a Modelica based dynamic simulation model for demonstrating the effectiveness of th...

2012-01-01

27

Legionella fairfieldensis sp. nov. isolated from cooling tower waters in Australia.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three Legionella-like organisms were isolated from water from the cooling towers of two Australian institutions. The strains grew on buffered charcoal-yeast extract (BCYE) agar but not on BCYE agar in the absence of L-cysteine. Gas-liquid chromatography profiles of the isolates were consistent with those for Legionella spp. They were serologically distinct from other legionellae in a slide agglutination test. DNA hybridization studies showed that the three isolates belong to a new species of ...

Thacker, W. L.; Benson, R. F.; Hawes, L.; Gidding, H.; Dwyer, B.; Mayberry, W. R.; Brenner, D. J.

1991-01-01

28

Plumes from one and two cooling towers  

International Nuclear Information System (INIS)

Use of mechanical- and natural-draft cooling towers is expanding in the United States in response to pressures for better resource allocation and preservation. Specifically, increasing public and regulatory concern over the effects of the intake and discharge of large volumes of cooling water has encouraged electric utilities to accept cooling towers as the primary method of removing condenser waste heat even though once-through cooling is considerably less expensive. Other factors encouraging the use of cooling towers include small water supply and consumption rates, reduction in land requirements (compared to cooling ponds or lakes), and operational flexibility. The growing demand for electric energy should also add to the increase of cooling tower use. The experimental program and its comparison to model prediction suggest that optimal siting of cooling towers, particularly multiple towers, is a task requiring knowledge of ambient wind history, plume dynamics, and tower operating conditions. Based on the tower wake effects and on the results for interaction of plumes from two cooling towers, site terrain may be a very significant factor in plume dynamics and interaction

1978-08-01

29

Extracellular polysaccharides produced by cooling water tower biofilm bacteria and their possible degradation.  

Science.gov (United States)

The extracellular polymers (EPS) of biofilm bacteria that can cause heat and mass transfer problems in cooling water towers in the petrochemical industry were investigated. In addition, these microorganisms were screened for their ability to grow and degrade their own EPS and the EPS of other species. Twelve bacteria producing the most EPS were isolated from cooling water towers and characterized biochemically by classic and commercial systems. These were species of Pseudomonas, Burkholderia, Aeromonas, Pasteurella, Pantoea, Alcaligenes and Sphingomonas. EPS of these species were obtained by propan-2-ol precipitation and centrifugation from bacterial cultures in media enriched with glucose, sucrose or galactose. EPS yields were of 1.68-4.95 g l(-1). These EPS materials were characterized for total sugar and protein contents. Their total sugar content ranged from 24 to 56% (g sugar g(-1) EPS), and their total protein content ranged from 10 to 28% (g protein g(-1) EPS). The monosaccharide compositions of EPS were determined by HPLC. Generally, these compositions were enriched in galactose and glucose, with lesser amounts of mannose, rhamnose, fructose and arabinose. All bacteria were investigated in terms of EPS degradation. Eight of the bacteria were able to utilize EPS from Burkholderia cepacia, seven of the bacteria were able to utilize EPS from Pseudomonas sp. and Sphingomonas paucimobilis. The greatest viscosity reduction of B. cepacia was obtained with Pseudomonas sp. The results show that the bacteria in this study are able to degrade EPS from biofilms in cooling towers. PMID:18256966

Ceyhan, Nur; Ozdemir, Guven

2008-01-01

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

The future cooling tower; Fremtidens koeletaarn  

Energy Technology Data Exchange (ETDEWEB)

This project has designed and built a pilot-scale cooling tower with an output of up to 100 kW for which good correlation has been ascertained between measured and calculated values for output and pressure loss. The new cooling tower will save approximately 15% of electricity consumption compared with the widespread dry coolers. The pilot tower uses rainwater so that both water consumption and electricity consumption are saved in softening plants. On the basis of this cooling tower, models have been made and these have been implemented in PackCalc II in order to calculate electricity and other operating savings. (Energy 11)

Ibsen, C.H. (Vestas Aircoil A/S, Lem St. (Denmark)); Schneider, P. (Teknologisk Institut, AArhus (Denmark)); Haaning, N. (Ramboell A/S, Copenhagen (Denmark)); Lund, K. (Nyrup Plast A/S, Nyrup (Denmark)); Soerensen, Ole (MultiWing A/S, Vedbaek (Denmark)); Dalsgaard, T. (Silhorko A/S, Skanderborg (Denmark)); Pedersen, Michael (Skive Kommune, Skive (Denmark))

2011-03-15

33

Hydraulic cooling tower driver  

International Nuclear Information System (INIS)

One of the weaknesses of present day cooling tower drives are fan wrecks caused by shaft couplings breaking, gear box malfunctions due to inadequate lubrication, gear tooth wear, and inaccessibility for inspection and routine maintenance. The hydro-drive eliminates these items from the drive train and puts the same electric motor HP at ground level close coupled to a hydraulic pump, filters, and oil reservoir. Hydraulic lines bring oil pressure to the hydraulic motor, which is more than 75% less weight than comparable gear boxes and presents a smooth practically trouble free performance. In this three cell installation, the original 75 horsepower motors and 18' diameter fans were cooling a total of 14,000 GPM which were CTI tested at 74.7% of capability. The upgrading and retrofit consisted of installing at ground level 100 horsepower motors, 22' diameter fans, 14' high velocity recovery fan cylinders, V PVC splash bars, and high efficiency cellular drift eliminators. Testing indicates a 92% tower now circulating 21,000 GPM instead of the original 14,000

1987-09-16

34

Legionella moravica sp. nov. and Legionella brunensis sp. nov. isolated from cooling-tower water.  

Science.gov (United States)

Two Legionella-like organisms were isolated from cooling-tower water samples in Czechoslovakia. They were presumptively identified as legionellae by their growth on buffered charcoal-yeast extract agar (BCYE) containing L-cysteine and their absence of growth on BCYE without L-cysteine. Both strains contained predominately branch-chained cellular fatty acids and were therefore definitively placed in the genus Legionella. They were serologically distinct from other described Legionella species and were shown by DNA studies to constitute two new Legionella species, Legionella moravica (type strain 316-36; ATCC 43877) and Legionella brunensis (type strain 441-1; ATCC 43878). PMID:3179063

Wilkinson, H W; Drasar, V; Thacker, W L; Benson, R F; Schindler, J; Potuznikova, B; Mayberry, W R; Brenner, D J

1988-01-01

35

Legionella fairfieldensis sp. nov. isolated from cooling tower waters in Australia.  

Science.gov (United States)

Three Legionella-like organisms were isolated from water from the cooling towers of two Australian institutions. The strains grew on buffered charcoal-yeast extract (BCYE) agar but not on BCYE agar in the absence of L-cysteine. Gas-liquid chromatography profiles of the isolates were consistent with those for Legionella spp. They were serologically distinct from other legionellae in a slide agglutination test. DNA hybridization studies showed that the three isolates belong to a new species of Legionella, Legionella fairfieldensis (ATCC 49588). PMID:2037664

Thacker, W L; Benson, R F; Hawes, L; Gidding, H; Dwyer, B; Mayberry, W R; Brenner, D J

1991-03-01

36

Developments in cooling tower components  

Energy Technology Data Exchange (ETDEWEB)

This article looks at recent developments to increase the service life and performance of cooling towers and at materials for constructing the towers and tower components. The history of the use of wood (redwood and Douglas fir) for tower structures in the USA is traced, and details are given of the use of plastic film fill media, pultruded FRP, and fire resistant resins. Improvements in film fill are discussed, and a case study involving the use of fire resistant UV protected vinylester resin fibre glass for the structural components in coil-shed cooling towers is presented.

Mirsky, G.; Haggerty, D. [Hamon Cooling Towers, Inc. (United States)

2000-01-01

37

Induced draught circular cooling tower  

International Nuclear Information System (INIS)

Induced draught atmospheric cooling towers are described, to wit those in which the circulation is by power fans. This technique with fans grouped together in the centre enables a single tower to be used and provides an excellent integration of the steam wreath into the atmosphere. This type of cooling tower has been chosen for fitting out two 900 MW units of the Chinon power station in France

1980-01-01

38

Pretreatment and ozonation of cooling tower water: part 2. Technical report  

Energy Technology Data Exchange (ETDEWEB)

Laboratory treatment of the sample involving Dissolved Air Flotation (DAF) pretreatment and in line ozonation was performed on a sample of recirculating cooling tower water that was obtained from Transo Envelope Company of Jersey City, NJ. Various parameters including turbidity, color, pH, total hardness, TOC, and bacteria levels as well as specific concentrations of constituents such as iron and copper were monitored. After each stage of experimentation various parameters were measured to determine optimum treatment for the specific water. Ozonation in combination with DAF pretreatment produced optimum water quality with the DAF pretreatment being responsible for most of the water quality improvement. Ozonation was found to be necessary for bacteria removal. Operating cost estimates are included and compared to those of a conventional system of chemical treatment.

Krofta, M.; Wang, L.K.; Kurylko, L.; Thayer, A.E.

1983-08-05

39

Cooling Towers: Principles and Practice  

Energy Technology Data Exchange (ETDEWEB)

This compact but rather expensive book deals with the analysis and design of evaporative cooling towers. It is aimed at practicing engineers or advanced students who wish to acquire an in-depth knowledge of the cooling tower technology. The book touches on almost every aspect of this technology including construction, operation, and maintenance.

Hill, G.B.; Pring, E.J.; Osborn, P.D. [eds.

1990-12-31

40

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

 
 
 
 
41

Legionella in Puerto Rico cooling towers.  

Science.gov (United States)

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. Sever...

A. Negron-Alviro I. Perez-Suarez T. C. Hazen

1988-01-01

42

Performance characteristics of a shower cooling tower  

International Nuclear Information System (INIS)

This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In contrast to conventional cooling towers, the cooling tower analyzed in this study is void of fill. By means of efficient atomization nozzles, a shower cooling tower (SCT) is possible to be applied in industry, which, in terms of water cooling, energy saving and equipment investing, is better than conventional packed cooling towers. However, no systematic thermodynamic numerical method could be found in the literature up to now. Based on the kinetic model and mass and heat transfer model, this paper has developed a one dimensional model for studying the motional process and evaporative cooling process occurring at the water droplet level in the SCT. The finite difference approach is used for three motional processes to obtain relative parameters in each different stage, and the possibility of the droplets being entrained outside the tower is fully analyzed. The accuracy of this model is checked by practical operational results from a full scale prototype in real conditions, and some exclusive factors that affect the cooling characteristics for the SCT are analyzed in detail. This study provides the theoretical foundation for practical application of the SCT in industry

2007-01-01

43

Wet/dry cooling tower field tests  

Energy Technology Data Exchange (ETDEWEB)

A one and one-half year test of the first wet/dry cooling tower built specifically to examine the water conservation aspects of wet/dry cooling was concluded. Previously, wet/dry cooling had been considered only when plume abatement requirements negated the economic disadvantages. The tower was rated by the manufacturer to cool 15,150 gallons per minute (gal/min) of recirculated water from an initial temperature of 115 F to a final temperature of 90 F with an atmospheric wet-bulb temperature of 75 F. 2 refs.

Burkhart, D.M.; Bartz, J.A.

1980-01-01

44

Variations of starting conditions contribution to cooling tower plume predictions  

International Nuclear Information System (INIS)

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)

1977-06-06

45

Cooling Tower Modification for Intermittent Operation.  

Science.gov (United States)

One of the cooling towers at Los Alamos Scientific Laboratory is being operated intermittently. The cooling tower has been modified to restrict air flow and to keep the tower from drying out. The modifications are relatively inexpensive, simple to operate...

W. S. Midkiff

1975-01-01

46

Cooling towers: The energy orphan  

Energy Technology Data Exchange (ETDEWEB)

It would be prudent for the engineer with responsibility for the efficient operation of a refrigeration/air conditioning system to have a professional inspection of the cooling tower by a consultant who can analyze the energy saving potential of his installation. In these days of high energy costs, the saving accrued from a well engineered and retrofitted cooling tower to bring it into the 1980s can make a significant impact on a company's profit and loss statement.

Burger, R.

1987-01-01

47

Stripping of phenols in model cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are used to remove waste heat from unit operations in chemical processing plants. Using cooling towers for wastewater treatment and disposal through internal recycling has become an important alternative because of stricter wastewater discharge standards, the expense of specialized wastewater treatment systems and the limited availability and cost of water in arid regions. Designs for synfuels plants must address the problem of wastewater disposal. Alternative systems under consideration usually include zero discharge designs that incorporate evaporative cooling towers in the system. The mechanisms for contaminant removal in cooling towers are biological oxidation, stripping and chemical precipitation. Chemical precipitation is generally considered undesirable because of losses in heat transfer efficiency. Predicting whether stripping or biological oxidation will be the primary removal mechanism for phenolic compounds from coal conversion wastewaters used as makeup in cooling towers does not appear to be possible based on the results of these tests. The tests do indicate that the biological oxidation of phenol is possible in forced draft cooling towers.

Turner, C.D.; Moe, T.A.; Wentz, C.A.

1987-01-01

48

Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.  

Science.gov (United States)

In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers. PMID:20009251

Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

2010-03-01

49

Liquid axial dispersion coefficient in a packed cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A dynamic method is used to predict the liquid axial dispersion coefficient in cooling towers. A KCl tracer was employed on the water inlet on the top of the tower. Input and response signals were measured. Cooling tower parameters were determined by predicting the response tracer signal and curve fitting technique in the time domain.

Younis, M.A.

50

Technology to Facilitate the Use of Impaired Waters in Cooling Towers  

Energy Technology Data Exchange (ETDEWEB)

The project goal was to develop an effective silica removal technology and couple that with existing electro-dialysis reversal (EDR) technology to achieve a cost effective treatment for impaired waters to allow for their use in the cooling towers of coal fired power plants. A quantitative target of the program was a 50% reduction in the fresh water withdrawal at a levelized cost of water of $3.90/Kgal. Over the course of the program, a new molybdenum-modified alumina was developed that significantly outperforms existing alumina materials in silica removal both kinetically and thermodynamically. The Langmuir capacity is 0.11g silica/g adsorbent. Moreover, a low cost recycle/regeneration process was discovered to allow for multiple recycles with minimal loss in activity. On the lab scale, five runs were carried out with no drop in performance between the second and fifth run in ability to absorb the silica from water. The Mo-modified alumina was successfully prepared on a multiple kilogram scale and a bench scale model column was used to remove 100 ppm of silica from 400 liters of simulated impaired water. Significant water savings would result from such a process and the regeneration process could be further optimized to reduce water requirements. Current barriers to implementation are the base cost of the adsorbent material and the fine powder form that would lead to back pressure on a large column. If mesoporous materials become more commonly used in other areas and the price drops from volume and process improvements, then our material would also lower in price because the amount of molybdenum needed is low and no additional processing is required. There may well be engineering solutions to the fine powder issue; in a simple concept experiment, we were able to pelletize our material with Boehmite, but lost performance due to a dramatic decrease in surface area.

Colborn, Robert

2012-04-30

51

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 of LP. The 5? end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5?-biotinylated probes. The amplification products were detected by using proxidase-labled anti dioxygenin antibody in a colorimetric reaction. The assay detected LP present in 1 L of 5 CTW samples examined. All of the samples were Legionella positive in both culture and PCR-ELISA methods. The PCR-ELISA assay appears to exhibit high specificity and is a more rapid technique in comparison with bacterial culture method. Thus could prove suitable for use in the routine examination of industrial CTW contamination.

Soheili Majid

2007-01-01

52

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

53

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

54

Dynamic analysis of cooling towers  

International Nuclear Information System (INIS)

Natural draught cooling towers are shell structures subjected to random vibrations due to wind turbulence and earthquake. The need of big power plant units has initiated the design of very large cooling towers. The random response of such structures may be analysed using a spectral approach and assuming a linear behaviour of the structure. As the modal superposition method is the most suitable procedure for this purpose it is necessary to determine the natural frequencies and mode shapes with adequate accuracy. (orig./GL)

1987-01-01

55

Survey of asbestos fibers in cooling tower waters at Goodyear Atomic Corporation  

International Nuclear Information System (INIS)

Monitoring of the recirculating water (RCW) system at Goodyear Atomic Corporation has been performed since late 1975, when detectable amounts of asbestos were found in the RCW. From August 1976 through may 1979, fiber counts varied from below detectable limits (0.7 x 10"6 fibers/liter) to 16.2 x 10"6 fibers/liter in the cooling tower water. These results were nearly identical to the initial asbestos fiber data obtained for RCW from December 1975 through July 1976. From January 1977 through May 1979, water samples from the X-616 Chromate Recovery Facility effluent and the X-611 Water Treatment Plant (RCW makeup) were also analyzed for asbestos, and fiber counts varied from below detectable limits to 0.7 x 10"6 fibers; liter and 1.4 x 10"6 fibers/liter, respectively. The number of fibers in the RCW system and at the X-611 and X-616 facilities does not present an environmental problem at this time. Beginning in June 1978, all samples collected were prepared for analysis by two methods after a United States Environmental Protection Agency-sponsored study demonstrated that a method different from the one used at Goodyear Atomic Corporation had essentially zero fiber losses. To date, no significant differences have been observed between the two methods. In the future, monitoring of asbestos fibers should continue on a periodic basis to determine if an asbestos fiber problem develops.Both methods of sample preparation should be utilized to firmly establish which method is best

1979-01-01

56

Discussion on Energy-saving Applications of Fanless Cooling Tower  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cooling tower is essential to both industrial development and comfortable living. Its development is closely related to human civilization and quality of life. To achieve the cooling effects and the efficiency performance of high inlet/outlet water temperature difference (?t) of cooling towers, a number of modern high technologies have been applied, while the design of cooling towers focuses on lightweight, compact size, elegant appearance, and durability. This study studied the performance ...

2011-01-01

57

Cooling Tower Overhaul of Secondary Cooling System in HANARO  

International Nuclear Information System (INIS)

HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power

2007-06-01

58

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

2008-02-11

59

Pretreatment and ozonation of cooling tower water: part 1. Technical report  

Energy Technology Data Exchange (ETDEWEB)

Current technology and research are reviewed concerning the treatment of water for cooling applications. Special emphasis is directed toward the use of ozonation as a water treatment option. Summation includes recommendations for areas of research and proposes components for a laboratory setup designed to test treatment of cooling water by ozonation and other physical-chemical processes, such as flotation and filtration.

Krofta, M.; Wang, L.K.; Kurylko, L.; Thayer, A.E.

1983-04-02

60

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

 
 
 
 
61

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

International Nuclear Information System (INIS)

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.)

1994-04-01

62

Cooling tower evaporation rates at high site elevations  

Energy Technology Data Exchange (ETDEWEB)

An investigation of the approximate evaporation rates from wet mechanical draft cooling towers has been made for various site elevations above sea level up to 3048 m (10,000 ft). The heat balance method used here is a refinement of those previously reported and includes an extension of previous results to higher elevations. Plots are provided for estimating evaporation as a function of cooling-tower load, ambient relative humidity and wet-bulb temperature, and cooling-tower site elevation. Comparisons of predicted make-up water usage by this study, from a previous study, and that predicted by some cooling tower manufacturers, at several sites and elevations are also presented.

Stewart, W.E.; Smith, D.R.

1984-01-01

63

Plant Vogtle cooling tower studies  

International Nuclear Information System (INIS)

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

2000-01-01

64

Emergency-shutdown cooling towers: considerations in the evolution of optimum tower design  

International Nuclear Information System (INIS)

The article discusses the various regulatory requirements and criteria governing the design of emergency-shutdown cooling towers for nuclear power plants. The effects of key tower parameters (e.g., wet-bulb temperature, flow rates, and heat load) on tower size and their interactions with system and safety requirements are explored. The evolution of the Seabrook station tower and its relationship to a companion cooling-water source (the Atlantic Ocean) are presented as an example of optimum tower/system design that complies with regulatory requirements

1976-01-01

65

Cooling tower modification for intermittent operation  

International Nuclear Information System (INIS)

One of the cooling towers at Los Alamos Scientific Laboratory is being operated intermittently. The cooling tower has been modified to restrict air flow and to keep the tower from drying out. The modifications are relatively inexpensive, simple to operate, and have proved effective. (U.S.)

1975-01-01

66

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

67

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

68

Legionella spp. in Puerto Rico cooling towers.  

Science.gov (United States)

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(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. PMID:3202625

Negrón-Alvíra, A; Pérez-Suarez, I; Hazen, T C

1988-10-01

69

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

70

Corrosion of mild steel in ozonised air-conditioning cooling tower water  

Energy Technology Data Exchange (ETDEWEB)

A field trial in an open-evaporative cooling water system resembling those used for air-conditioning units has shown that ozonisation of the water is ineffective in protecting mild steel from corrosion. This finding is at variance with reported favourable experience in the USA. In the trial, the corrosion resistance of steel test coupons in water treated with sodium nitrite - a conventional corrosion inhibitor - was more than five times better than in ozonised water. The results were corroborated by electrochemical measurements. Ozone is not recommended for use for air-conditioning cooling system water, therefore, even though it is an effective biocide against the bacteria responsible for Legionnaires' disease.

Bird, T.L.

1987-08-01

71

Three-dimensional numerical analysis of wet cooling tower  

International Nuclear Information System (INIS)

A mathematical model for water evaporation and water droplet movement is established to describe the air-water interaction in natural draft wet cooling tower (NDWCT). The standard k - ? model is used to close the Reynolds average Navier-Stokes equations. The three-dimensional heat and mass transfer process in NDWCT is simulated to analyze the crosswind effect on wet cooling tower performance. It is found that the heat and mass transfer in fill zone is seriously affected by crosswind, while the wet cooling tower performance is improved when crosswind velocity is higher than 5 mcs-1. Conditions and locations for good cooling performance are pointed out

2008-02-01

72

Climatic impacts of nuclear power plant cooling towers  

International Nuclear Information System (INIS)

The problems are discussed relating to the impact of waste heat from cooling towers of nuclear power plants on the energy balance in the atmosphere. The potential impacts from the release of waste heat and water from wet cooling towers into the ambient atmosphere are given. (B.S.)

1979-04-06

73

Experimental study of cooling tower performance using ceramic tile packing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 simpl...

2013-01-01

74

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.  

Science.gov (United States)

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01). PMID:23439037

Minno?, Bihter; Ilhan-Sungur, Esra; Çotuk, Ay??n; Güngör, Nihal Do?ruöz; Cansever, Nurhan

2013-01-01

75

Numerical simulation of counter-flow wet-cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are used to cool a warm water stream through evaporation of part of the water into an air stream. A cooling tower consists of three zones; namely spray, 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 numerically using a computer code. 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 1.5% when the spray and rain zones are neglected. This error is reduced to 1.1% and 0.25% as the spray and rain zones are incorporated in the model, respectively. Furthermore, the effect of the Lewis factor on the performance prediction of wet-cooling towers is investigated using Bosnjakovic equation. (author)

Heidarinejad, Ghassem; Karami, Maryam [Department of Mechanical Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran (Iran); Delfani, Shahram [Building and Housing Research Center (BHRC), P.O. Box 13145-1696, Tehran (Iran)

2009-08-15

76

Performance of cool towers under various climates in Jordan  

Energy Technology Data Exchange (ETDEWEB)

The concept of cool towers, which is a modem version of the historical wind catchers was re-visited. In contrast with the expression of cooling towers, which usually refers to equipment used to cool the water in power stations, air conditioning plants etc., cool towers are used to cool the air to provide comfort conditions for occupants. The main driving force for air in cool towers is the difference in density of air between the inside and outside of the tower. Since the inside air is cooler than the outside, its density is higher and the resulting density difference creates a reversed chimney effect. This effect translates into the flow of cold air down the tower to the conditioned space. A new set of criteria for Amman, Jordan was used in this work, which resulted in a realistic performance of the tower. In addition, the performance of the tower was studied for other climatic regions of Jordan, such as the desert areas, Jordan valley (Ghor) and Aqaba, where air conditioning is needed most. It was found that under those climates, the height of the tower necessary to create proper air flow is less than 9 m. This is in contrast to the traditional design which may reach up to 15 m in height. A tower of 4 m height can produce the equivalent of 1t of refrigeration. (Author)

Badran, Ali A. [Jordan Univ., Dept. of Mechanical Engineering, Amman (Jordan)

2003-11-01

77

Effect of Phosphorous Addition to Model Cooling Towers Using Coal Gasification Wastewater as Makeup.  

Science.gov (United States)

Cooling towers are an integral part of in-plant water reuse systems in industries such as the Great Plains Gasification Plant being constructed at Beulah, North Dakota. Cooling towers can be used to reduce water requirements, remove biodegradable organics...

B. D. Priebe C. D. Turner

1984-01-01

78

The study on the evaporation cooling efficiency and effectiveness of cooling tower of film type  

International Nuclear Information System (INIS)

Based on heat and mass transport mechanism of film type cooling, which was combined with an on-site test on counter flow film type cooling tower, a mathematical model on the evaporation and cooling efficiency and effectiveness has been developed. Under typical climatic conditions, air conditioning load and the operating condition, the mass and heat balances have been calculated for the air and the cooling water including the volume of evaporative cooling water. Changing rule has been measured and calculated between coefficient of performance (COP) and chiller load. The influences of air and cooling water parameters on the evaporative cooling efficiency were analyzed in cooling tower restrained by latent heat evaporative cooling, and detailed derivation and computation revealed that both the evaporative cooling efficiency and effectiveness of cooling tower are the same characteristics parameters of the thermal performance of a cooling tower under identical assumptions.

2011-01-01

79

Cooling towers, the neglected energy conservations and money making machine  

Energy Technology Data Exchange (ETDEWEB)

The heat Rejection Industry defines a nominal cooling tower as circulating three gallons of water per minute (GPM) per ton of refrigeration from entering the tower at 95 {degrees}F, Hot Water temperature (HWT), Leaving at 85{degrees}F Cold Water Temperature (CWT) at a Design Wet Bulb of 70{degrees}F (WBT). Manufacturers then provide a selection chart based on various wet bulb temperatures and HWTs. The wet bulb fluctuates and varies throughout the world since it is the combination ambient temperature, relative humidity, and/or dew point. Different HWT and CWT requirements are usually charted as they change, so that the user can select the nominal cooling tower model recommended by the manufacturer. In the specification of cooling towers it is necessary to clearly understand the definition of nominal cooling tower, and to make sure the specification you need addressed can be met by the system you purchase. This should be tested prior to final acceptance.

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

1996-12-31

80

Method for dimensioning crossflow cooling towers  

International Nuclear Information System (INIS)

EDF has started a research programme relating to the operation of crossflow cooling towers. Tests have been conducted at the Nantes-Chevire bench as part of this programme: different fill configurations have been tested, varying the height and depth of the splash bars and the type of distribution nozzles. Measurements have also been taken in large cooling towers coupled with 900 MW(e) nuclear units. Test bench and on-site measurements consisted of vertical temperature and air velocity profiles at the inlet and outlet of the fill, as well as horizontal flow and water temperature profiles at the base of the fill. These readings have revealed horizontal transfer phenomena of the water flow and vertical transfer of the air flow, which are not portrayed by small test benches. These phenomena have been taken into account in a simplified two dimensional computation model of a crossflow fill, integrated to the TEFERI model. The results secured by computation using the exchange laws measured using the Nantes test bench are in good agreement with on-site measurements. This method has been applied to the prediction of efficiency of large cooling towers coupled with 1300 MW units and to the study of possible improvements to their operation

1989-04-01

 
 
 
 
81

System design description for the CPDF water systems: SDD-11 including: Part A, Machine cooling water (MCW): Part B, Tower Water Cooling (TWC): Part C, Sanitary water: Part D, Fire protection: Part E, Sanitary sewer and building drainage  

International Nuclear Information System (INIS)

The purpose of the System Design Descriptions (SDD's) for the Centrifuge Plant Demonstration Facility (CPDF) is to provide a concise summary of the functional and design requirements, design details, operations and maintenance procedures, and emergency events and recovery procedures for the various systems of the CPDF. SDD-1, ''Overall Facility Design Description for the CPDF,'' provides an overview of the entire CPDF and includes requirements which are unique to all or several systems within the CPDF. This volume covers: machine cooling water; tower water cooling; sanitary water; fire protection; and sanitary sewer and building drainage

1987-01-01

82

Improving the efficiency of natural draft cooling towers  

International Nuclear Information System (INIS)

This study shows how the efficiency of a natural draft cooling tower can be improved by optimising the heat transfer along the cooling tower (CT) packing using a suitable water distribution across the plane area of the cooling tower. On the basis of cooling air measurements, it is possible to distribute the water in such a way that it approaches the optimal local water/air mass flow ratio and ensures the homogeneity of the heat transfer and a reduction of entropy generation, thus minimising the amount of exergy lost. The velocity and temperature fields of the air flow were measured with the aid of a remote control mobile robot unit that was developed to enable measurements at an arbitrary point above the spray zone over the entire plane area of the cooling tower. The topological structures of the moist air velocity profiles and the temperature profiles above the spray zone were used as input data for calculation of the local entropy generation in the tower. On the basis of the measured boundary conditions, a numerical analysis of the influence of the water distribution across the cooling tower's plane area on entropy generation and exergy destruction in the cooling tower was conducted

2006-06-01

83

Observed cooling tower plume characteristics  

International Nuclear Information System (INIS)

In-plume measurements with an instrumented Cessna 411 aircraft were made at the Rancho Seco Nuclear Generating Station (913 MWe) near Sacramento, California; the Trojan nuclear plant (1130 MWe) on the Columbia River 50 mi. north of Portland, Oregon; and the coal-fired Centralia Steam Plant (1400 MWe) 50 mi. north of the Trojan plant. Additional surface-based operations conducted at Rancho Seco included pibal tracking to determine the wind velocity profile, time-exposure photographs of the plume for external plume definition and measurements of sulfate deposition due to the drift of entrained circulating water. Heat rejection at Rancho Seco is from two 425 ft. natural-draft towers whose exit diameters are 195 ft; at Trojan, from a single 500 ft. natural-draft tower with exit diameter of 250 ft; and at Centralia, from four mechanical-draft towers. Results of the analyses to date are summarized for three days' operation at Rancho Seco (February 17, 18, and 20 in 1975) and one day (May 13, 1976) at Trojan and Centralia. During the course of these flights, measurements of temperature, humidity, turbulence, Aitken nuclei, and cloud droplet spectra were taken

1976-06-16

84

Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.  

Science.gov (United States)

Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former. PMID:21214028

Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

2010-12-01

85

Noise emissions of cooling towers; Geraeuschemissionen von Kuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers are often large structures with high sound emission. The impact of water drops on the water surface in the collecting basin leads to the generation of middle- and high-frequency noise that is emitted via the air intake opening and the outlet. In forced-draft cooling towers, additional noise is generated by drives and fans. The sound emissions can be predicted by means of empirical calculation models. In this way, noise control measures can be taken into account already at an early phase of planning. Different, proven measures for reduction of sound emissions are taken depending on cooling tower design. Regulations on noise acceptance testing for cooling towers are given in various standards. (orig.)

Hinkelmann, Dirk [Mueller-BBM GmbH, Gelsenkirchen (Germany)

2013-09-01

86

Water quality indices for thermal inputs from cooling tower plants. Gewaesserbezogene Auswahlkriterien fuer Kuehlverfahren thermischer Kraftwerke als Beitrag zur Bewertung von Waermeeinleitungen im Vorfluter  

Energy Technology Data Exchange (ETDEWEB)

Thermal inputs from cooling-tower-plants may but don't necessarily have to cause river pollution. An economical and ecological reasonable input management must differ between seasons and take water quality (especially organic pollution) into account. Administration may do this by means of paragraph 36 (WHG), using a new model for thermal effects on self-purification and evaporation.

Rincke, G.; Kaltenbrunner, H.F.; Rudolph, K.U.

1980-01-01

87

The effect of evaporation losses in the analysis of crossflow cooling towers  

International Nuclear Information System (INIS)

The Merkel method for the thermal design of counterflow and crossflow cooling towers neglects the variation of the water flow from the tower inlet to outlet. It has been shown that neglecting the water evaporation losses introduces inaccuracies in the performance calculation of counterflow cooling towers. This study develops a method for including these evaporation losses and demonstrates that the error in the Merkel method for crossflow cooling towers may reach 20% depending on the design conditions. (Auth.)

1975-01-01

88

On thermal performance of seawater cooling towers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Seawater cooling towers have been used since the 1970s in power generation and other industries, so as to reduce the consumption of freshwater. The salts in seawater are known to create a number of operational problems, including salt deposition, packing blockage, corrosion, and certain environmental impacts from salt drift and blowdown return. In addition, the salinity of seawater affects the thermophysical properties that govern the thermal performance of cooling towers, including vapor pre...

Sharqawy, Mostafa H.; Lienhard, John H.; Zubair, Syed M.

2010-01-01

89

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

90

Enhancing performance of wet cooling towers  

International Nuclear Information System (INIS)

The effect of windbreak walls on the thermal performance of natural draft wet cooling towers (NDWCT) under crosswind has been investigated numerically. The three dimensional CFD model has utilised the standard k-? turbulence model as the turbulence closure to quantify the effects of the locations and porosities of the wall on the NDWCT thermal performance. Moreover, the improvement in the NDWCT thermal performance due to windbreak walls has been examined at different crosswind directions. Results from the current investigation have demonstrated that installing solid impermeable walls in the rain zone results in degrading the performance of the NDWCT. However, installing solid walls at the inlet of the NDWCT has enhanced the NDWCT performance at all of the investigated crosswind velocities. Similarly, installing walls with low porosity has shown improvement in the performance of the NDWCT. A reduction of 0.5-1 K in the temperature of the cooling water coming from the tower to the condenser has been achieved at all of the investigated crosswind velocities by installing porous walls both inside and outside the rain zone

2007-10-01

91

Enhancing performance of wet cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The effect of windbreak walls on the thermal performance of natural draft wet cooling towers (NDWCT) under crosswind has been investigated numerically. The three dimensional CFD model has utilised the standard k-{epsilon} turbulence model as the turbulence closure to quantify the effects of the locations and porosities of the wall on the NDWCT thermal performance. Moreover, the improvement in the NDWCT thermal performance due to windbreak walls has been examined at different crosswind directions. Results from the current investigation have demonstrated that installing solid impermeable walls in the rain zone results in degrading the performance of the NDWCT. However, installing solid walls at the inlet of the NDWCT has enhanced the NDWCT performance at all of the investigated crosswind velocities. Similarly, installing walls with low porosity has shown improvement in the performance of the NDWCT. A reduction of 0.5-1 K in the temperature of the cooling water coming from the tower to the condenser has been achieved at all of the investigated crosswind velocities by installing porous walls both inside and outside the rain zone. (author)

Al-Waked, Rafat [Umow Lai Enginuity Pty Ltd., Consulting Engineers, Level 1, 360 Pacific Highway, Crows Nest, NSW 2065 (Australia); Behnia, Masud [Dean of Graduate Studies, The University of Sydney, Sydney, NSW 2006 (Australia)

2007-10-15

92

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

93

Counter-Flow Cooling Tower Test Cell  

Directory of Open Access Journals (Sweden)

Full Text Available The article contains a design of a functional experimental model of a cross-flow mechanical draft cooling tower and the results and outcomes of measurements. This device is primarily used for measuring performance characteristics of cooling fills, but with a simple rebuild, it can be used for measuring other thermodynamic processes that take part in so-called wet cooling. The main advantages of the particular test cell lie in the accuracy, size, and the possibility of changing the water distribution level. This feature is very useful for measurements of fills of different heights without the influence of the spray and rain zone. The functionality of this test cell has been verified experimentally during assembly, and data from the measurement of common film cooling fills have been compared against the results taken from another experimental line. For the purpose of evaluating the data gathered, computational scripts were created in the MATLAB numerical computing environment. The first script is for exact calculation of the thermal balance of the model, and the second is for determining Merkel’s number via Chebyshev’s method.

Dvo?ák Lukáš

2014-03-01

94

Counter-Flow Cooling Tower Test Cell  

Science.gov (United States)

The article contains a design of a functional experimental model of a cross-flow mechanical draft cooling tower and the results and outcomes of measurements. This device is primarily used for measuring performance characteristics of cooling fills, but with a simple rebuild, it can be used for measuring other thermodynamic processes that take part in so-called wet cooling. The main advantages of the particular test cell lie in the accuracy, size, and the possibility of changing the water distribution level. This feature is very useful for measurements of fills of different heights without the influence of the spray and rain zone. The functionality of this test cell has been verified experimentally during assembly, and data from the measurement of common film cooling fills have been compared against the results taken from another experimental line. For the purpose of evaluating the data gathered, computational scripts were created in the MATLAB numerical computing environment. The first script is for exact calculation of the thermal balance of the model, and the second is for determining Merkel's number via Chebyshev's method.

Dvo?ák, Lukáš; Noži?ka, Ji?í

2014-03-01

95

Structure of natural draft cooling towers, 1  

International Nuclear Information System (INIS)

Thousands of natural draft cooling towers have been utilized, in Europe and America, as cooling systems of power plants or as countermeasures against thermal polution. Recently in Japan, demands for cooling tower systems have been increasing remarkably with the construction of large power plants and the legislation of environmental regulations. In view of the severe natural conditions in Japan such as strong wind and seismic loadings, etc., the establishment of the optimum design and construction method is essential for the building of safe and economical towers. In order to establish a comprehensive plan of a power plant cooling system of the appropriate structural type, the authors have made researches and experiments on design conditions, static and dynamic analyses, and comparative studies of various structural types such as reinforced concrete thin-shell structures, steel framed structures and composite shell segment structures, based on the investigation results of towers in Europe and America. These results are presented in three reports, the 1st of which concerns cooling tower shells as are hereinafter described. (auth.)

1976-01-01

96

Built-in cooling device for cooling towers  

International Nuclear Information System (INIS)

For a universal grate as a construction element of cooling towers design information is given. The grate may, in a single form, be superposed as often as is desired with spacers in between. It meets the requirement that the four edges of all grates may be put vertically one over the other and that falling water drops, after passing about four grates, will hit one of the baffle plates, with which the intersections of the webs, forming the grates, are provided. The water running down from top to bottom is thus forced to permanently change the flow direction, resulting in maximum turbulence, distribution and cooling. The grates are turned by 90 degrees from one platform to another. (HP)

1975-01-01

97

Microphysical and optical features of polluted cooling tower clouds  

International Nuclear Information System (INIS)

In November 1993 an airborne field study was performed to investigate the microphysical and radiative properties of cooling tower water clouds initiated by water vapour emissions and polluted by the exhaust from coal-fired power plants. The results show, that the link between radiative and microphysical properties of natural clouds is not changed by the extreme pollution of the artificial clouds

1997-06-01

98

Improvement of coal focus and cooling towers of COFRENTES NPP  

International Nuclear Information System (INIS)

Cofrentes Nuclear Power Plant is performing a improving program of its cooling towers based on the filling revamping and cooling water circuit improvement. Furthermore, and as consequence of the acquired experience on cooling towers due to the mentioned program, Cofrentes NPP has decided to follow up with this project from a different point of view based on the thermal-hydraulic optimization of the cooling process inside the towers. This program, which is going to be carried out by Cofrentes NPP, Iberinco and Energy Planning and Power Generation (EPPG) provides an improvement on the thermal profile and of the draught inside the cooling towers by improving the water distribution in the towers active area. In order to perform such a program is needed to fulfill a test program to assure a guaranteed performance gain. In this way, Iberinco is developing a test procedure which improves the results which are obtained with the present standards used commonly by the industry. As a consequence of this program, Cofrentes is expecting to obtain a gain of 5 to 8 MWe with a revenue period of 4 to 5 months, results validated in another foreigner Plant which have developed a similar program. (Author)

1998-01-01

99

Advanced integral model for cooling tower plume dispersion  

Energy Technology Data Exchange (ETDEWEB)

An advanced integral model is developed for predicting cooling tower plume rise from single natural draft cooling towers. The theoretical formulation of the model is aimed at avoiding many of the pitfalls and unnecessary assumptions of existing models. The model is based on a careful integration of the three-dimensional partial differential equations of conservation across the plume cross-section; radial profiles of temperature, velocity, and total water are assumed to be Gaussian in shape. The model includes a treatment of plume thermodynamics and tower downwash effects. The model has been calibrated with a wide range of laboratory data. Verification of the model with single-tower field data from Chalk Point, Paradise, Lunen, Gardanne and Philippsburg reveals good results.

Schatzmann, M.; Policastro, A.J.

1984-01-01

100

The shape of natural draft cooling towers  

International Nuclear Information System (INIS)

The shape of cooling towers is more often designed empirically. There, it is considered from a theoretical point of view. The analysis of dynamic of natural draft and of the air flow in a cooling tower shell is presented. It is shown, that although it is convergent, a tower works like a diffuser for pressure recovery. And it is turbulence that produces a transfer of kinetic energy and allows a good operation of the diffusor. The equations permit to define a shell profile which depends upon the operating conditions of the cooling tower. In the same way, a stability criteria for natural draft depending upon operating conditions is established. A heating model of one meter diameter has been built in a thermal similitude. The turbulence rate has been measured with a hot wire anemometer at the tower exit and visualizations have also been made. Natural draft stability has been studied by these means for four different shell shapes and a wide range of operating conditions. Experimental and theoretical results agree satisfactorily and experiments can be considered as a validation of theory

1992-01-01

 
 
 
 
101

Sensitivity Studies of a Low Temperature Low Approach Direct Cooling Tower for Building Radiant Cooling Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent interest in cooling towers as a mechanism for producing chilled water, together with the evolutionof radiant cooling, have prompted a review of evaporative cooling in temperate maritime climates. The thermal efficiency of such systems is a key parameter, as a measure of the degree to which the system has succeeded in exploiting the cooling potential of the ambient air. The feasibility of this concept depends largely however, on achieving low approach water temperatures with...

Nasrabadi, Mehdi; Finn, Donal; Costelloe, Ben

2012-01-01

102

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

103

Natural draft dry cooling tower modelling  

Science.gov (United States)

Predictions based on a numerical simulation of a natural draft dry cooling tower (NDDCT) has been compared with those obtained theoretically and experimentally. Experiments are conducted in a lab-scale NDDCT and are validated with a three-dimensional numerical simulation of the flow in and around the heat exchangers, which is modelled as a porous medium. Both vertical and horizontal arrangements of the heat exchangers are examined. The experimental, numerical and theoretical approaches lead to very close prediction for the air velocity and temperature at the exit of the cooling tower. Results of this study are expected to be useful for future work on the development of air-cooled condensers for geothermal power plants in Australia.

Tanimizu, K.; Hooman, K.

2013-02-01

104

Performance characteristics of the hybrid closed circuit cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Experimental study on the hybrid closed circuit cooling tower (HCCCT) has been done having a rated capacity of 136 kW. Bare-type copper coil having an outer diameter of 15.88 mm has been used in the 1.14 m x 2.36 m x 3.2 m dimensional tower. Cooling capacity and pressure drop have been studied with respect to variable air inlet velocities, wet-bulb temperatures, cooling water inlet temperatures and air to cooling water volume flow rate ratio (G/W ratio). Performance characteristics from the experimental study were found to conform well to the rated ones. The results are supposed to serve as basic design parameter for the HCCCT. (author)

Sarker, M.M.A. [Department of Mathematics, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Kim, E.; Moon, C.G.; Yoon, J.I. [Department of Refrigeration and Air-conditioning Engineering Pukyong National University, Namgu, Pusan 608-739 (Korea, Republic of)

2008-07-01

105

Wet/dry cooling tower eliminates plume at Teesside  

Energy Technology Data Exchange (ETDEWEB)

Environmental reaction to the plumes from a cooling tower for the first gigawatt scale combined cycle CHP plant in the United Kingdom gave rise to an extraordinary engineering feat of retrofitting new hybrid parallel-path wet/dry cooling towers to work in conjunction with the existing single hyperbolic fan assisted cooling tower on an already compact site. (author)

Anon.

1995-10-01

106

A study of a desuperheater heat recovery system complete with a reversibly used water cooling tower (RUWCT) for hot water supply  

Science.gov (United States)

Recovering heat rejected from the condenser in a refrigeration system to generate service hot water for buildings is commonly seen in both tropics and subtropics. This study included a critical literature review on heat recovery from air-conditioning/refrigeration systems, with particular emphasis on the direct condenser heat recovery and its related mathematical simulation models. The review identified many applications of desuperheaters to small-scaled residential air-conditioning or heat pump units. The heat and mass transfer characteristics of a RUWCT have been studied in detail, which is based on the theory of direct contact heat and mass transfer between moist air and water. The thesis reports on the differences in the heat and mass transfer process that takes place in a RUWCT, a standard water cooling tower and a spray room. A corrective factor that accounts for the change of chilled water mass flow rate is incorporated into the theoretical analysis of a RUWCT. The algorithms developed from the theoretical analysis are capable of predicting the heat exchange capacity of a RUWCT at any operating conditions. This theoretical analysis is the first of its kind. Extensive field experimental work on the heat and mass transfer characteristics of a RUWCT has been carried out in a hotel building in Haikou, Hainan province of China, where the RUWCT is installed. Results from the experimental work indicate that the theoretical analysis can represent the heat and mass transfer characteristics in a RUWCT with an acceptable accuracy. A numerical analysis for a RUWCT is undertaken to determine both air and water states at intermediate horizontal sections along the tower height. Field experimental data confirm that the predicted air and water conditions at the tower inlet and outlet are of acceptable accuracy. A steady-state mathematical model is developed to simulate the operational performance of a water chiller plant complete with a desuperheater heat recovery system and a RUWCT. This model will be useful in future studies on the optimum design of a water chiller complete with a desuperheater and a RUWCT for heat recovery. (Abstract shortened by UMI.)

Tan, Kunxiong

107

A New Algorithm for Optimum Design of Mechanical Draft Wet Cooling Towers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. The design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. The design model incorporated the cooling tower factors to achieve the optimum design. The main factors included: the diameter of the water droplets, the liquid to gas mass ratio, the height of rain zone, packing zone and spray zone, the ai...

2009-01-01

108

Thermal performance of a closed wet cooling tower for chilled ceilings: measurement and CFD simulation  

Energy Technology Data Exchange (ETDEWEB)

A closed wet cooling tower, adapted for use with chilled ceilings in buildings, was tested experimentally. The thermal efficiency of the cooling tower was measured for different air flow rates, water flow rates, spray flow rates and wet bulb air temperatures. CFD was also used to predict the thermal performance of the cooling tower. Good agreement was obtained between CFD prediction and experimental measurement. (Author)

Riffat, Saffa; Guohui Gan; Doherty, Prince [Nottingham Univ., Inst. of Building Technology, Nottingham (United Kingdom); Oliveira, Armando; Facao, Jorge [Porto Univ., Dept. of Mechanical Engineering and Industrial Management, Porto (Portugal)

2000-07-01

109

Evaluation of Cooling Tower Performance RSG-GAS Reactor Using One Line Cooling System  

International Nuclear Information System (INIS)

Utilization of the reactor operation must be done as optimal as possible, so that reactor operation needed efficiently. Reactor power needed in the operation continuously maximum only 15 MW, in this case can be anticipated by doing only using one line cooling system from two line cooling system is available. The consequences by using one line cooling system, it will be impact among performance of cooling tower, for that it is needed research about this case. The research of Multipurpose Reactor GA. Siwabessy's cooling tower when the reactor operator by one line cooling system conducted using the data of operation at 10 MW. The results of calculation showed that for design condition, the ratio of water flow rate to air (L/G) is 1.52, and number transfer unit (NTU) is 0.348. For experiment condition, it is achieved the average of L/G and NTU are 1.37 and 0.342 respectively. The performance value of cooling tower from experiment condition is 91%. That value is greater than feasible value for operation capability cooling tower from acceptable test procedure for industrial cooling tower namely 80%. (author)

2005-10-01

110

Evaluation of treated gasification wastewater as cooling tower makeup  

Energy Technology Data Exchange (ETDEWEB)

The principal goal of gasification research at the University of North Dakota Energy Research Center (UNDERC) is to develop process and environmental data on the treatability and reuse of aqueous effluents from the fixed-bed gasification of lignite. It is the objective of the UNDERC wastewater research program to define the extent of treatment required to produce a gas liquor for use as cooling tower makeup that will have no adverse effects on operating equipment or on the environment. The UNDERC pilot wastewater treatment scheme was designed to simulate the wastewater reuse process being used at the Great Plains Gasification Associates (GPGA) lignite gasification facility near Beulah, North Dakota. At GPGA, aqueous gasifier waste streams are treated via the Phenosolvan and Phosam-W processes to remove the bulk of the wastewater organics as well as ammonia and acid gases. This minimally treated wastewater, referred to as stripped gas liquor (SGL), is fed to the process cooling towers. At UNDERC, SGL was produced from a pilot slagging fixed-bed gasifier (SFBG) followed by extraction and steam-stripping treatment. UNDERC wastewater was used initially to determine the effects of cooling tower wastewater reuse before GPGA wastewater became available. An additional cooling tower reuse test was performed with water from GPGA. This work addresses the comparative effects of wastewater from the UNDERC slagging gasifier and the GPGA dry-ash gasifier on cooling system operation. 14 refs., 6 figs., 5 tabs.

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

1985-04-01

111

A systemic approach for optimal cooling tower operation  

International Nuclear Information System (INIS)

The thermal performance of a cooling tower and its cooling water system is critical for industrial plants, and small deviations from the design conditions may cause severe instability in the operation and economics of the process. External disturbances such as variation in the thermal demand of the process or oscillations in atmospheric conditions may be suppressed in multiple ways. Nevertheless, such alternatives are hardly ever implemented in the industrial operation due to the poor coordination between the utility and process sectors. The complexity of the operation increases because of the strong interaction among the process variables. In the present work, an integrated model for the minimization of the operating costs of a cooling water system is developed. The system is composed of a cooling tower as well as a network of heat exchangers. After the model is verified, several cases are studied with the objective of determining the optimal operation. It is observed that the most important operational resources to mitigate disturbances in the thermal demand of the process are, in this order: the increase in recycle water flow rate, the increase in air flow rate and finally the forced removal of a portion of the water flow rate that enters the cooling tower with the corresponding make-up flow rate.

2009-09-01

112

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

113

Recent developments of cooling tower design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Natural draught cooling towers (NDCT) are the characterizing landmarks of power stations. They contribute both to an efficient energy output and to a careful balance with our environment. In the last decade the building of new power plants stagnated all over the world. Nowadays the German power suppliers have started an extensive renewal program, where old units will be replaced by new ones, which will be much cleaner and more efficient. Besides innovative boiler techniques the sustainable an...

2009-01-01

114

Susceptibility of Legionella pneumophila to three cooling tower microbicides.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 d...

Grace, R. D.; Dewar, N. E.; Barnes, W. G.; Hodges, G. R.

1981-01-01

115

Rainfall enhancement due to scavenging of cooling tower condensate  

International Nuclear Information System (INIS)

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

1978-08-01

116

Design method of operation and operating experience of the wet/dry cooling tower  

Energy Technology Data Exchange (ETDEWEB)

In contrast to older direct water cooled plants at the Altbach site, the condensing heat from the new unit no. 5 is conveyed to the atmosphere in a closed circuit system via a cooling tower. The economically optimum solution without doubt proved to be a natural draught cooling tower. With its 83 m diameter base and 115 m total height it would have become the most dominating structure on the power station site, but would, being sited well into the relatively narrow Neckar Valley between Plochingen and Stuttgart, have found no acceptance by the public. These factors led to a wet/dry cooling tower, also known as a hybrid cooling tower, which exploits the advantages of wet and dry cooling and produces no visible vapour plumes. With the use of ventilators a cooling tower stack can be avoided so that the structural height is substantially reduced.

Alt, M.; Alt, W.

1987-04-01

117

Test report: wet/dry cooling tower test module. Final report  

Energy Technology Data Exchange (ETDEWEB)

The engineering performance of a single-cell wet/dry cooling tower was evaluated in an 18-month field test at San Bernardino, California. Test objectives included determination of the water conservation and operating characteristics and verification of a mathematical model of the wet/dry cooling tower. The crossflow tower had parallel air flows through the wet and dry sections and dampers which regulated air flow to allow cooling by either the wet or dry sections, or any combination of the two. Without significantly affecting normal plant performance, the wet/dry cooling tower could save approximately 19% of the water normally evaporated annually by an all-wet tower at the test site. Greater savings could have been achieved by accepting some loss of plant efficiency during the winter months. The mathematical model developed for the tower was verified by test results. Although some operatonal problems developed during testing, the major goals of the test program were achieved.

Burkhart, D.M.

1980-08-01

118

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

119

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

120

Testing and evaluation of spray nozzles for counterflow cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Cooling towers may be viewed as heat exchangers which require work input to elevate and distribute water into a flowing air stream to achieve combined heat and mass transfer. Counterflow cooling towers employ an array of coarse spray nozzles operating at low head to spread water over a suitable fill occupying the plan area of the tower. Although the spray patterns from individual nozzles are usually overlapped, it is still difficult to produce a uniform areal deposition of water. The purpose of this paper is to establish appropriate testing procedures and to present observations of performance in relationship to nozzle configuration. To this end, several representative nozzles were tested and various measures of performance were established for individual nozzles as well as arrays. Spray pattern superposition and interference have been examined by simple experimental techniques, which include both sampling and enhanced visualization. Ultimately, the results of this experimental investigation can be used to relate individual nozzle selection to the overall performance of the tower.

Buyens, D.J.; Kranc, S.C. [Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering

1995-12-31

 
 
 
 
121

The use of an electrical-fluid dynamic parameter in cooling tower  

Energy Technology Data Exchange (ETDEWEB)

An Electrical-Fluid Dynamic quality parameter is defined for a mechanical draft type cooling tower. It allows to evaluate the efficiency of the transformation of the electrical power input into kinetic energy of the air flow. It could also be used to calculate the active electrical power of the tower at different working conditions. Results obtained through tests in a small counterflow water cooling tower are shown.

Sirena, J.A. [Univ. Nacional de Cordoba (Argentina). Facultad de Ciencias Exactas

1999-11-01

122

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

123

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

International Nuclear Information System (INIS)

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.

2012-12-01

124

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

125

Influence of geometric imperfections on cooling towers  

International Nuclear Information System (INIS)

A review of the efforts made by researches over the past ten years to understand the behaviour of an imperfect cooling tower, to analyse it with adequate numerical tools and to provide reliable guidance to design. Three types of imperfections have been considered: meridional, circumferencial and local imperfections. Parametric studies to clarify the influence of the shell and imperfection parameters are reviewed, followed by simplified models and existing and proposed tolerance specifications. A review of numerical techniques used to model imperfections is also presented. Finally, some areas for future research are indicated. (Author)

1984-10-03

126

Microphysical and optical features of polluted cooling tower clouds  

Science.gov (United States)

In November 1993 an airborne field study was performed in order to investigate the microphysical and radiative properties of cooling tower water clouds initiated by water vapour emissions and polluted by the exhaust from coal-fired power plants. The number-median diameter of the droplet size distributions of these artificial clouds was in the range of 13 ?m. The concentration of smaller droplets (diameters dD cooling towers. Close to the cooling towers, bimodal spectra were found with a second mode at 19 ?m. The liquid water content (LWC) ranged between 2 and 5 g/m 3 and effective droplet radii ( Re) between 6 and 9 ?m were measured. LWC and Re decreased with altitude, whereas the droplet concentration ( ND) remained approximately constant (about 2000 cm -3 ). An enrichment of interstitial aerosol particles with particle diameters ( dp) smaller 0.2 ?m compared to the power plant plume in the vicinity of the clouds was observed. Particle activation for dm > 0.3 ?m. was evident, especially in cooling tower clouds further apart and separated from their sources. Furthermore, radiation measurements were performed, which revealed differences in the vertical profiles of downwelling solar and UV radiation flux densities inside the clouds. The effective droplet radius Re was parameterized in terms of LWC and ND using equations known from literature. The close agreement between measured and parameterized Re indicates a similar coupling of Re, LWC and ND as in natural clouds. By means of Mie calculations, volume scattering coefficients and asymmetry factors are derived for both the cloud droplets and the aerosol particles. For the cloud droplets, the optical parameters were described by parameterizations from the literature. The results show, that the link between radiative and microphysical properties of natural clouds is not changed by the extreme pollution of the artificial clouds.

Mertes, S.; Wendisch, M.

127

Measurements at cooling tower plumes. Part 3. Three-dimensional measurements at cooling tower plumes  

International Nuclear Information System (INIS)

An extended field experiment is described in which cooling tower plumes were studied by means of three-dimensional in situ measurements. The goal was to obtain input data for numerical models of cooling tower plumes. Of special interest were data for testing or developing assumptions for sub-grid parametrizations. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station Neurath and also two (1975) at the single cooling tower of the RWE power station Meppen. Because of the broad spectrum of weather situations it can be assumed that the results are representative with regard to the interrelationship between structure of cooling tower plume and large-scale meteorological situation. A large number of flights with a powered glider crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapor pressure. Therefore, a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the boundary, which could be defined by the mentioned jumps of temperature and vapor pressure, a maximum of downward vertical motion could be observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. High-resolution aerology is necessary in order to explain the structure and behavior of such plumes. This is especially the case in investigations regarding the dynamic break-through of temperature inversions. Such cases were observed frequently under various meteorological conditions and are described

128

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.

2009-11-01

129

Thermal performance upgrade of the Arkansas Nuclear One cooling tower: A ``root cause`` analysis approach  

Energy Technology Data Exchange (ETDEWEB)

The thermal performance efficiency of the natural draft cooling tower at Entergy Operations` 858 MWe Arkansas Nuclear One, Unit 2 was successfully upgraded to 101% of design performance capability in April 1994 as the end result of a unique root-cause analysis of the cooling tower`s long-standing performance deficiencies. Through application of state-of-the-art diagnostic testing methods and computer modeling techniques, Entergy was able to identify and correct air/water maldistribution problems in the 447 foot tall counterflow cooling tower at minimal cost. Entergy estimates that the savings realized, as a result of the 1.2 F reduction in cooling tower outlet water temperature, will pay for the thermal upgrade project in approximately 14 months.

Liffick, G.W. [Entergy Operations, Inc., Russellville, AR (United States); Cooper, J.W. Jr. [John Cooper and Associates, Tampa, FL (United States)

1995-10-01

130

Influence of temperature inversions on wet-cooling tower performance  

Energy Technology Data Exchange (ETDEWEB)

Nocturnal temperature inversions have a detrimental effect on the performance of natural draft wet-cooling towers. The effects of the temperature inversion profile, the height of the inversion and the height from which air is drawn into the cooling tower, on the performance of cooling towers are investigated. Relatively simple and accurate equations are employed in the analysis to determine the temperature inversion profiles and inversion heights, which only have ground based measurements as input. The detrimental effect in tower performance, during nocturnal temperature inversions, is due to the reduced potential in draft and the increase of the effective air inlet temperature. (Author)

Kloppers, J.C. [Sasol Technology (Pty) Ltd., Secunda (South Africa); Kroeger, D.G. [Stellenbosch Univ., Dept. of Mechanical Engineering, Stellenbosch (South Africa)

2005-06-01

131

Cooling towers, the overlooked energy conservation profit center  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the specification of cooling towers and their potential for energy savings when operated and maintained correctly. The topics of the paper include design conditions, function of lower temperature, importance of the wet bulb temperature, state of the are upgrading, and case histories of two installations where cooling tower performance was improved.

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

1995-10-01

132

Improving performance and reducing costs of cooling towers  

International Nuclear Information System (INIS)

Cooling towers represent a significant capital investment at a steam electric power station. In addition, deficiencies in thermal performance can result in major operating penalties of fuel cost, replacement energy, and capacity addition. This paper summarizes two recent EPRI research projects aimed at reducing thermal performance deficiencies and decreasing installed costs of evaporative cooling towers. First, EPRI Research Project 2113, Cooling Tower Performance Prediction and Improvement, is summarized. This project has resulted in published data sets on the measured thermal performance characteristics of a variety of cooling tower packings, computer codes to predict tower performance, and computer code validation through large-scale tower performance measurements. Principal results are contained in an EPRIGEMS software module, Cooling Tower Advisor. This PC- based software contains a tutorial plus codes to predict tower thermal performance, arranged in a user-friendly format. The second EPRI effort, Research Project 2819-10/11, Fabric Structures for Power Plant Applications, has resulted in designs and costs of large structures with shells constructed of recently-developed fabrics. Primary power plant applications for such structures are the shells of natural draft cooling towers and coal-pile covers. Fabric structures offer low initial cost, acceptable life, and seismic superiority, among other advantages. Detailed conceptual designs and installed cost data are reviewed. 8 refs., 9 figs., 3 tabs

1992-07-01

133

Combined wet/dry cooling towers of cell-type construction  

Energy Technology Data Exchange (ETDEWEB)

This article provides a general picture of the state of technical developments with respect to wet/dry cooling towers. More stringent environmental protection requirements led to the introduction of the hybrid cooling tower, which effectively suppresses detrimental plume formation at an efficiency level comparable to that of the wet cooling tower. It is explained that the attainable exhaust air state, in conjunction with the ambient air state, is the only possible basis for a decision in order to obtain both a low-priced design and proper functioning. The cell-type construction, including material selection and automatic operation of the recooling system, is described in detail. In the last section, the fluid cooling tower, designed for a closed circuit, is presented as a combination of the essential elements of wet and dry cooling technology. When the ambient temperature is low, the fluid cooling tower can also be operated as a dry cooling tower, i.e., without water consumption or plume production. Both hybrid and fluid cooling towers of the cell type conform particularly well to the more stringent environmental protection requirements and to the standard of operational reliability set for recooling systems. It is therefore to be expected that use of these types will become more widespread.

Streng, A. [Balke-Duerr GmbH, Ratingen (Germany)

1998-12-01

134

Prevalence study of Simkania negevensis in cooling towers in Spain.  

Science.gov (United States)

Simkania negevensis is an obligate intracellular bacterium grouped into the order Chlamydiales. This new amoeba-resistant intracellular bacterium might represent a novel etiologic agent of bronchiolitis and community-acquired pneumonia and occurs in aquatic habitats such as drinking water and reclaimed wastewater. Another amoeba-related bacterium, Legionella pneumophila, is an etiologic agent of pneumonia transmitted by environmental aerosols or contaminated water/air cooling systems. These transmission pathways are important in the natural history of Legionellae infections and possibly other intracellular microorganisms such as Parachlamydiaceae; thus, understanding the feasibility of Simkania infection by these routes is relevant. In the present work, we investigated the prevalence of this newly identified pathogenic bacterium in cooling towers by quantitative PCR (qPCR) and its possible relationship with Legionella pneumophila co-infection. Our results show Simkania detection in 2 of 70 cooling towers analyzed. To our knowledge, this report is the first describing Simkania negevensis detection in this category of environmental water samples. PMID:21942196

Pérez, Leonardo Martín; Codony, Francesc; Ríos, Karina; Adrados, Bárbara; Fittipaldi, Mariana; De Dios, Gregori; Peńuela, Gustavo; Morató, Jordi

2011-06-01

135

Available new technology to improve cooling tower long term performance  

Energy Technology Data Exchange (ETDEWEB)

Electric generating stations throughout the world have their cooling provided by a variety of different cooling tower designs, or are on an open cycle system which may even have a cooling tower. Achieving continuously the best possible performance from these cooling towers impacts generating capacity. newly developed components are available today which are designed to improve the efficiency and dependability of the cooling tower. These new components include fill, distribution nozzles, drift eliminators and fans. This paper covers: (1) Analyzing the area of efficiency loss; (2) Establishing the performance baseline; (3) Discussion of new components available to improve long term performance. This includes fill, nozzles, drift eliminators and fans; (4) Cost comparison examples of the repack benefit. The example will include a comparison of fill types; (5) The construction of the repacking of a large utility cooling tower; (6) The Acceptance Test; and (7) Documentation of the long term performance improvements of the new fill designed to reduce fouling. Significant advances have been made in the designs of cooling tower components, they have been incorporated into existing and new cooling towers, and their benefits have been documented by many third party tests.

Mirsky, G.M. [Hamon Cooling Towers, Bridgewater, NJ (United States)

1995-02-01

136

Amorphous Silica Scale in Cooling Waters.  

Science.gov (United States)

In 1968, most of the evaporation cooled recirculating water systems at Los Alamos Scientific Laboratory were nearly inoperable due to scale. These systems, consisting of cooling towers, evaporative water coolers, evaporative condensers, and air washers ha...

W. S. Midkiff H. P. Foyt

1976-01-01

137

Stimulatory effect of cooling tower biocides on amoebae.  

Science.gov (United States)

Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtained from the American Type Culture Collection (ATCC) and were also tested. The cooling tower isolates were more resistant to most of the biocides than the ATCC isolates were. The isothiazolin derivative was the least inhibitory to all four amoeba isolates, and tributyltin neodecanoate mixed with quaternary ammonium compounds was the most inhibitory to three of the four isolates. After exposure to lower concentrations of the biocides, including for one strain the manufacturer's recommended concentration of one biocide, the cooling tower amoeba populations increased significantly compared with unexposed controls, whereas the ATCC isolates were not stimulated at any of the concentrations tested. In some cases, concentrations which stimulated cooling tower amoebae inhibited the growth of the ATCC isolates. These results suggest that cooling tower amoebae may adapt to biocides, underscoring the need to use freshly isolated cooling tower organisms rather than organisms from culture collections for testing the efficacy of such biocides. The stimulatory effect of biocides on amoeba populations is an alarming observation, since these organisms may be reservoirs for legionellae. Biocides used to control microbial growth may actually enhance populations of host organisms for pathogenic bacteria.

Srikanth, S; Berk, S G

1993-01-01

138

Drift measurements at ENEL ISTRIA pilot cooling tower  

International Nuclear Information System (INIS)

The present paper shows the experimental results of drift measurements obtained in the ISTRIA pilot cooling tower that ENEL has built in Livorno. The determination of drift has been performed by measuring the content of silica in the water released by a sample of fluid mixture collected just above the drop separators. The obtained results seem to indicate the influence of the drop separators geometry on the drift, showing that the most complex geometry gives the corresponding lowest values of drift and vice versa. Such low values of drift are nevertheless payed with an increase in the pressure drop in the drop separation zone

1990-09-01

139

'Free cooling' with blower-ventilated cooling towers - energy conservation in refrigeration at low ambient temperatures  

Energy Technology Data Exchange (ETDEWEB)

The characteristic parameter determining cooling tower efficiency is the cooling water outlet temperature achievable in given operating conditions. At low ambient temperatures, comparable to the wet-bulb temperature, and relatively low cooling loads, cooling water temperatures around 12/sup 0/C can be achieved quite economically. It is of advantage that the yearly average of hours with low wet-bulb temperatures is quite high in our climate.

Boettcher, C.

1987-05-01

140

State of development of centripetal ventilators for cooling towers  

International Nuclear Information System (INIS)

In the nuclear power station at Biblis, the conventional central cooling tower ventilator has been replaced by a large number of smaller axial ventilators arranged on the outer shell of the cooling tower in the air intake region. Tests have been carried out with the aim of finding a practicable blade system for a centripetal cooling tower ventilator. The blower veel diameter of this model ventilator is about 1 m. Using the model laws, the knowledge gained here may be applied to large-scale systems with diameters of 100-150 m or more. (orig.)

1976-10-04

 
 
 
 
141

Fire behaviour of cooling tower packing; Brandverhalten von Kuehlturmeinbauten  

Energy Technology Data Exchange (ETDEWEB)

The rapid burning down of the cooling tower of the shutdown power plant in Schwandorf revealed the potential of a total loss of a cooling tower in case of fire. VGB ordered a research project in order to obtain more knowledge about the fire risk of cooling tower packing currently applied. Depending on kind and age of the plastics used, the results of these tests manifest a big variation of the fire behaviour. For the applications of plastics, it is essential to determine and to adhere to organisational fire protection measures. (orig.)

Mattausch, Tim [DMT GmbH und Co. KG, Dortmund (Germany). Fachstelle fuer Brandschutz

2013-10-01

142

Cooling tower wood sampling and analyses: A case study  

International Nuclear Information System (INIS)

Extensive wood sampling and analyses programs were initiated on crossflow and counterflow cooling towers that have been in service since 1951 and 1955, respectively. Wood samples were taken from all areas of the towers and were subjected to biological, chemical and physical tests. The tests and results for the analyses are discussed. The results indicate the degree of wood deterioration, and areas of the towers which experience the most advanced degree of degradation

1985-01-01

143

Strategy for the Operation of Cooling Towers with variable Speed Fans  

CERN Multimedia

Within the SPS Cooling Water Project at CERN aimed at the reduction of water consumption, this primary open cooling loop will be closed and all the primary cooling circuit components will be upgraded to the new required duty and brought to the necessary safety and operability standards. In particular the tower fans will be fitted with variable frequency drives to replace the existing two speed motors. This paper presents a study to optimize the operation of SPS cooling towers taking into account outdoor conditions (wet and dry bulb temperatures) and the entirety of the primary circuit in which they will operate.

Ińigo-Golfín, J

2001-01-01

144

On the influence of psychrometric ambient conditions on cooling tower drift deposition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health reasons. A numerical model to study the influence of sychrometric ambient conditions on cooling tower drift deposition was developed. The mathematical model presented, consisting of two coupled sets of conservation equations for the continuous and discrete phases, was incorporated in the general purpose CFD code Fluent. Both experimental plume performance and drift deposition were employed...

Lucas Marti?nez, Manuel; Ruiz Rami?rez, Javier; Sa?nchez Kaiser, Antonio; Viedma, A.; Marti?nez Beltra?n, Pedro Juan

2010-01-01

145

Numerical simulation of cooling performance of wind tower (Baud-Geer) in hot and arid region  

Energy Technology Data Exchange (ETDEWEB)

In the present study, an attempt is made to study the cooling performance of a wind tower in a hot and dry region, Yazd, in Iran. For the relevant experiments and numerical studies, at first, the temperature and wind velocity inside and outside of the wind tower measured. Based on four-day measurements during last summer, a computer program was designed with language C{sup ++} to solve the equations. Also in the study the effects of parameters including wind tower height, variety of the materials used in the wind tower walls, the amount of vaporized water, the temperature of input and output air, the wind velocity and the relative humidity were investigated. Furthermore, to develop, a natural flow of air, for days without blowing a wind the role of solar chimney was considered. Finally, to evaluate the method of integral view and take information about streamlines of airflow in wind tower (Baud-Geer), velocity, pressure, humidity, temperature and density profile of fluid, Fluent software is applied to analyze the air flow in the wind tower in differential view for three-dimensional and steady state conditions with water spraying at the top of wind tower. The results indicate that the evaporative cooling is very effective in a hot and dry region. The temperature decreases considerably, if the wind towers are equipped with the water vaporization system. This causes the air becomes heavier and a natural motion of air through downside of wind tower to be produced. (author)

Kalantar, Vali [Mechanical Department of Yazd University, Yazd (Iran)

2009-01-15

146

Numerical model of evaporative cooling processes in a new type of cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A numerical model for studying the evaporative cooling process that take place in a new type of cooling tower has been developed. In contrast to conventional cooling towers, this new device called Hydrosolar Roof presents lower droplet fall and uses renewable energy instead of fans to generate the air mass flow within the tower. The numerical model developed to analyse its performance is based on computational flow dynamics for the two-phase flow of humid air and water droplets. The Eulerian approach is used for the gas flow phase and the Lagrangian approach for the water droplet flow phase, with two-way coupling between both phases. Experimental results from a full-scale prototype in real conditions have been used for validation. The main results of this study show the strong influence of the average water drop size efficiency of the system and reveal the effect of other variables like wet bulb temperature, water mass flow to air mass flow ratio and temperature gap between water inlet temperature and wet bulb temperature. Nondimensional numerical correlation of efficiency as a function of these significant parameters has been calculated. (author)

Kaiser, A.S.; Viedma, A.; Zamora, B. [Universidad Politecnica de Cartagena (Spain). Dpto. de Ingenieria Tecnica y de Fluidos; Lucas, M. [Universidad Miguel Hernandez, Elche (Spain). Dpto. de Ingenieria de Sistemas Industriales

2005-02-01

147

Performance prediction of a multi-stage wind tower for indoor cooling  

Science.gov (United States)

A theoretical model is developed to establish an in-depth understanding of the performance of a three-stage wind tower with a bypass system for indoor cooling in rural dry and hot climates. Model simulations are presented for a wide range of ambient conditions that include inlet wind speed, inlet temperature and relative humidity. Simulation results provide an insight into the desirable water flow rates and air-to-water loadings for comfort zone temperatures and relative humidity levels at the exit of the wind tower. Simulations show wind towers with variable cross-sections provide an increase in the cooling power for the same inlet wind speed, inlet air temperature and relative humidity when compared to wind towers with a constant cross-section. The study shall lead to a better understanding to designing wind towers that are both environmentally friendly and energy efficient.

Issa, Roy J.; Chang, Byungik

2012-08-01

148

Natural-draught cooling towers made of reinforced concrete  

International Nuclear Information System (INIS)

Large power plant units and dry cooling tower technology require larger dimensions for natural-draught cooling towers. The main curvation radii in latitudinal and meridian direction are thus increased, which results in a lower three-dimensional support strength. This development is an incentive for constant re-consideration of calculation methods, safety philosophy, and dimensioning criteria. In this context, wind effects have been re-formulated and given a scientific foundation. Constructional measures to improve the static and dynamic behaviour of the structure have been presented and critically assessed. A cost analysis, finally, gave the most rational applications of the new shell construction with reinforcing elements. A cooling tower now under construction gave a realistic example. Fundamental aspects concerning the foundations of cooling tower shells and two special types of foundation are further points to clarify the subject. (orig./HP)

1978-01-01

149

Lower parts of Temelin nuclear power plant cooling towers  

International Nuclear Information System (INIS)

The progress of work is described in detail on the foundations and lower parts of the cooling towers of the Temelin nuclear power plant. The cooling tower is placed on a reinforced concrete footing of a circular layout. Support pillars are erected on the reinforced concrete continuous footing. They consists of oblique shell stanchions. Inside, the footing joins up to monolithic wall and slab structures of the cooling tower tub. The tub bottom forms a foundation plate supporting prefab structures of the cooling tower inner structural systems. The framed support of the chimney shell consists of 56 pairs of prefabricated oblique stanchions. Following their erection into the final position and anchoring in the continuous footing, the concreting of the casing can start of the reinforced conrete chimney. (Z.M.). 3 figs

1988-01-01

150

Stimulatory effect of cooling tower biocides on amoebae.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtai...

Srikanth, S.; Berk, S. G.

1993-01-01

151

Simultaneous detection of Legionella species and Legionella pneumophila by duplex PCR (dPCR assay in cooling tower water samples from Jakarta, Indonesia  

Directory of Open Access Journals (Sweden)

Full Text Available Aim: Since culture method is time-consuming and has low  sensitivity, we developed a duplex PCR (dPCR assay for the detection of Legionella sp. and L. pneumophila in cooling tower samples. We used culture method as a gold standard.Methods: Optimization of dPCR method was performed to obtain an assay with high sensitivity and specifi city. The optimized method was used to detect Legionella sp. dan L. pneumophila in 9 samples obtained from 9 buildings in Jakarta. For culture method, the bacteria were grown or isolated on selective growth factor supplemented-buffered charcoal yeast extract (BCYE media.Results: Of 9 samples tested by dPCR assay, 6 were positive for Legionella species,1 was positive for L. pneumophila, and 2 showed negative results. For the same samples, no Legionella sp. was detected by the culture method.Conclusion: dPCR assay was much more sensitive than the culture method and was potentially used as a rapid, specifi c and sensitive test for routine detection of Legionella sp. dan for L. pneumophila in water samples. (Med J Indones 2010; 19:223-7Keywords: BCYE media, mip gene, 16S-rRNA gene

Andi Yasmon

2010-11-01

152

Simultaneous detection of Legionella species and Legionella pneumophila by duplex PCR (dPCR) assay in cooling tower water samples from Jakarta, Indonesia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim: Since culture method is time-consuming and has low  sensitivity, we developed a duplex PCR (dPCR) assay for the detection of Legionella sp. and L. pneumophila in cooling tower samples. We used culture method as a gold standard.Methods: Optimization of dPCR method was performed to obtain an assay with high sensitivity and specifi city. The optimized method was used to detect Legionella sp. dan L. pneumophila in 9 samples obtained from 9 buildin...

Andi Yasmon; Yusmaniar Yusmaniar; Anis Anis; Budiman Bela

2010-01-01

153

Cooling towers - source prediction, modelling, specification and noise control  

Energy Technology Data Exchange (ETDEWEB)

The SoundPLAN computer noise model was used to predict the sound power levels of the principal sources of noise in a wet cell cooling tower. The issue of specifying noise limits for wet cell cooling towers was also examined, and the options for noise mitigation were identified. The major components of a typical wet cell cooling tower as found in petrochemical, power, utility and other industrial facilities, were shown. Fan noise and watersplash are two of the principal sources of noise in a wet cell cooling tower. The secondary sources of noise are motor noise and gearbox noise. The characteristics and prediction methods for each noise source were examined in detail. Some options for noise control included locating the cooling tower further away from communities, perhaps even in remote locations, to fit the towers with a parallel baffle silencer or with stack silencers to silence the fan. Reducing the fan speed at night will result in a 15 dB reduction in fan noise. The construction of a noise wall or barrier could also be considered in extreme cases. 20 refs., 4 tabs., 6 figs.

Derrick, M.C. [HFP Acoustical Consultants Ltd., Calgary, AB (Canada)

1998-09-01

154

Hudson River cooling tower proceeding: Interface between science and law  

International Nuclear Information System (INIS)

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

155

Thermal power plant cooling tower systems: CTI (Italy) norm  

Energy Technology Data Exchange (ETDEWEB)

This CTI (Italian Thermotechnical Committee) norm governs the design of systems for the discharge of steam condensation heat, deriving from steam generators, into the environment. The norm includes standardized terminology, cooling system classification (direct and indirect exchange), construction material guidelines, cooling tower typology and basic flowsheets.

Comitato Termotecnico Italiano

1990-10-01

156

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

157

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

158

Statistical multi-model approach for performance assessment of cooling tower  

International Nuclear Information System (INIS)

This paper presents a data-driven model-based assessment strategy to investigate the performance of a cooling tower. In order to achieve this objective, the operations of a cooling tower are first characterized using a data-driven method, multiple models, which presents a set of local models in the format of linear equations. Satisfactory fuzzy c-mean clustering algorithm is used to classify operating data into several groups to build local models. The developed models are then applied to predict the performance of the system based on design input parameters provided by the manufacturer. The tower characteristics are also investigated using the proposed models via the effects of the water/air flow ratio. The predicted results tend to agree well with the calculated tower characteristics using actual measured operating data from an industrial plant. By comparison with the design characteristic curve provided by the manufacturer, the effectiveness of cooling tower can be obtained in the end. A case study conducted in a commercial plant demonstrates the validity of proposed approach. It should be noted that this is the first attempt to assess the cooling efficiency which is deviated from the original design value using operating data for an industrial scale process. Moreover, the evaluated process need not interrupt the normal operation of the cooling tower. This should be of particular interest in industrial applications.

2011-02-01

159

Statistical multi-model approach for performance assessment of cooling tower  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a data-driven model-based assessment strategy to investigate the performance of a cooling tower. In order to achieve this objective, the operations of a cooling tower are first characterized using a data-driven method, multiple models, which presents a set of local models in the format of linear equations. Satisfactory fuzzy c-mean clustering algorithm is used to classify operating data into several groups to build local models. The developed models are then applied to predict the performance of the system based on design input parameters provided by the manufacturer. The tower characteristics are also investigated using the proposed models via the effects of the water/air flow ratio. The predicted results tend to agree well with the calculated tower characteristics using actual measured operating data from an industrial plant. By comparison with the design characteristic curve provided by the manufacturer, the effectiveness of cooling tower can be obtained in the end. A case study conducted in a commercial plant demonstrates the validity of proposed approach. It should be noted that this is the first attempt to assess the cooling efficiency which is deviated from the original design value using operating data for an industrial scale process. Moreover, the evaluated process need not interrupt the normal operation of the cooling tower. This should be of particular interest in industrial applications. (author)

Pan, Tian-Hong [School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Shieh, Shyan-Shu [Department of Occupational Safety and Health, Chang Jung Christian University, 71101 (China); Jang, Shi-Shang; Tseng, Wen-Hung [Chemical Engineering Department, National Tsing-Hua University, Hsin-Chu 30047 (China); Wu, Chan-Wei; Ou, Jenq-Jang [Energy and Air Pollution Control Section, New Materials Research and Development Dept., China Steel Corporation, Kaohsiung 80012 (China)

2011-02-15

160

Water cooling system for RILAC2  

International Nuclear Information System (INIS)

This Water Cooling System (Photograph 1) is the one newly established only for new incident machine RILAC2 under construction in March, 2010 because of the large strength beam making about RIBF. The cooling method to use past Cooling Tower is the one when characterizing to cool the device by using the cold water generated from difference absorption chiller. (author)

2010-08-04

 
 
 
 
161

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

162

An exergy analysis on the performance of a counterflow wet cooling tower  

International Nuclear Information System (INIS)

Cooling towers are used to extract waste heat from water to atmospheric air. An energy analysis is usually used to investigate the performance characteristics of cooling tower. However, the energy concept alone is insufficient to describe some important viewpoints on energy utilization. In this study, an exergy analysis is used to indicate exergy and exergy destruction of water and air flowing through the cooling tower. Mathematical model based on heat and mass transfer principle is developed to find the properties of water and air, which will be further used in exergy analysis. The model is validated against experimental data. It is noted from the results that the amount of exergy supplied by water is larger than that absorbed by air, because the system produces entropy. To depict the utilizable exergy between water and air, exergy of each working fluid along the tower are presented. The results show that water exergy decreases continuously from top to bottom. On the other hand, air exergy is expressed in terms of convective and evaporative heat transfer. Exergy of air via convective heat transfer initially loses at inlet and slightly recovers along the flow before leaving the tower. However, exergy of air via evaporative heat transfer is generally high and able to consume exergy supplied by water. Exergy destruction is defined as the difference between water exergy change and air exergy change. It reveals that the cooling processes due to thermodynamics irreversibility perform poorly at bottom and gradually improve along the height of the tower. The results show that the lowest exergy destruction is located at the top of the tower

2007-04-01

163

Cooling towers for 1000 MW nuclear power unit  

International Nuclear Information System (INIS)

The project is discussed of one single cooling tower with natural draft for one nuclear power plant unit. Two towers are designed for one unit of the Temelin power plant and the construction of one single tower for one unit is being considered. A brief economic analysis is made on the basis of experience and foreign data, and a comparison made with Czechoslovak projects. The use of a single tower will save 20% of capital costs and further savings will be achieved in the pipelines and built-up area. The relative cost of the tower depends on the temperature of ambient air, the dimensions of the tower, on shower intensity. There are also considerable differences in power generation with constant heat consumption. Briefly presented is the procedure of the calculation of deviations in power generation from rated states, which are the basis for economic evaluation and the choice of the optimal variant of cooling towers. (M.D.). 8 figs., 2 tabs., 6 refs

1988-10-01

164

Oil well rig with water tower  

Energy Technology Data Exchange (ETDEWEB)

An oil well rig having a flotatable hull and support legs which are lifted and supported by the floating hull for moving the oil well rig and moved down to engage the sea bottom and jack up or raise the hull above the water at an operating site for drilling or servicing a well or serving an offshore well platform. A water tower has pipes longitudinally mounted by brackets on each side on a beam and is mounted for vertical movement in a well in the hull. An elevator mechanism mounted in the hull is employed to raise and lower the water tower which has guide means fitting a guide portion of the well to provide guided vertical movement of the water tower. When the water tower is lowered, a pump at the bottom of the pipe pumps sea water through the pipe to machinery on the hull to meet the water requirements of the machinery.

Younes, D. T.

1984-09-18

165

CFD MODELING AND ANALYSIS FOR A-AREA AND H-AREA COOLING TOWERS  

Energy Technology Data Exchange (ETDEWEB)

Mechanical draft cooling towers are designed to cool process water via sensible and latent heat transfer to air. Heat and mass transfer take place simultaneously. Heat is transferred as sensible heat due to the temperature difference between liquid and gas phases, and as the latent heat of the water as it evaporates. Mass of water vapor is transferred due to the difference between the vapor pressure at the air-liquid interface and the partial pressure of water vapor in the bulk of the air. Equations to govern these phenomena are discussed here. The governing equations are solved by taking a computational fluid dynamics (CFD) approach. The purpose of the work is to develop a three-dimensional CFD model to evaluate the flow patterns inside the cooling tower cell driven by cooling fan and wind, considering the cooling fans to be on or off. Two types of the cooling towers are considered here. One is cross-flow type cooling tower located in A-Area, and the other is counterflow type cooling tower located in H-Area. The cooling tower located in A-Area is mechanical draft cooling tower (MDCT) consisting of four compartment cells as shown in Fig. 1. It is 13.7m wide, 36.8m long, and 9.4m high. Each cell has its own cooling fan and shroud without any flow communications between two adjacent cells. There are water distribution decks on both sides of the fan shroud. The deck floor has an array of about 25mm size holes through which water droplet falls into the cell region cooled by the ambient air driven by fan and wind, and it is eventually collected in basin area. As shown in Fig. 1, about 0.15-m thick drift eliminator allows ambient air to be humidified through the evaporative cooling process without entrainment of water droplets into the shroud exit. The H-Area cooling tower is about 7.3 m wide, 29.3 m long, and 9.0 m high. Each cell has its own cooling fan and shroud, but each of two corner cells has two panels to shield wind at the bottom of the cells. There is some degree of flow communications between adjacent cells through the 9-in gap at the bottom of the tower cells as shown in Fig. 2. Detailed geometrical dimensions for the H-Area tower configurations are presented in the figure. The model was benchmarked and verified against off-site and on-site test results. The verified model was applied to the investigation of cooling fan and wind effects on water cooling in cells when fans are off and on. This report will discuss the modeling and test results.

Lee, S.; Garrett, A.; Bollinger, J.

2009-09-02

166

A case of nosocomial Legionella pneumonia associated with a contaminated hospital cooling tower.  

Science.gov (United States)

We report the epidemiological investigation of a nosocomial pneumonia case due to Legionella pneumophila linked to a contaminated hospital cooling tower in an immune-compromised patient. A 73-year-old female patient was diagnosed with nosocomial Legionella pneumonia proven by a culture of L. pneumophila serogroup 1 from bronchoalveolar lavage fluid. Two strains isolated from the patient and two strains isolated from two cooling towers were found to be identical using repetitive-sequence-based-PCR with a 95% probability. This Legionella pneumonia case might be caused by aerosol from cooling towers on the roof of the hospital building which was contaminated by L. pneumophila. We increased up the temperature of hot water supply appropriately for prevention of Legionella breeding in an environment of patients' living. On the other hand, as the maintenance of cooling tower, we increased the frequency of Legionella culture tests from twice a year to three times a year. In addition, we introduced an automated disinfectants insertion machine and added one antiseptic reagent (BALSTER ST-40 N, Tohzai Chemical Industry Co., Ltd., Kawasaki, Japan) after this Legionella disease, and thereafter, we have no additional cases of Legionella disease or detection of Legionella spp. from the cooling tower or hot water supply. This case demonstrates the importance of detecting the infection source and carrying out environmental maintenance in cooperation with the infection control team. PMID:24462430

Osawa, Kayo; Shigemura, Katsumi; Abe, Yasuhisa; Jikimoto, Takumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

2014-01-01

167

Cooling tower practice in Germany: state of the art  

International Nuclear Information System (INIS)

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

1982-01-01

168

French operational experience on fouling problems (algae, bryozoas) in cooling towers  

International Nuclear Information System (INIS)

Electricite de France (EDF) has committed itself to the adoption of some technical procedures and the development of environmental research actions in the fields of water, air, noise, fauna, flora, landscapes and the occupation of space. Continuous chlorination has been replaced by massive chlorination with the blowdown of the cooling tower closed, which prevents free chlorine from being released into the environment. In addition, massive chlorination is only undertaken when a fouling threshold has been reached. However, other arms need to be introduced by EDF by reason of major biological growth (algea, bryozoa) which remains unaffected by sodium hypochlorite solution injections. This paper presents the findings of studies conducted by the Aquatic and Atmospheric Environment Department on the optimization of the injections of sodium hypochlorite solution and the infestation of cooling towers by algae and bryozoa. It is a part of the inter-directorate working group's mandate relating to conditioning of the circulation water cooling towers

1989-04-01

169

Computer optimization of dry and wet/dry cooling tower systems for large fossil and nuclear power plants  

International Nuclear Information System (INIS)

This study determined the cost of dry cooling compared to the conventional cooling methods. Also, the savings by using wet/dry instead of all-dry cooling were determined. A total optimization was performed for power plants with dry cooling tower systems using metal-finned-tube heat exchangers and surface condensers. The optimization minimizes the power production cost. The program optimizes the design of the heat exchanger and its air and water flow rates. In the base case study, the method of replacing lost capacity assumes the use of gas turbines. As a result of using dry cooling towers in an 800 MWe fossil plant, the incremental costs with the use of high back pressure turbine and conventional turbine over all-wet cooling are 11 and 15%, respectively. For a 1200 MWe nuclear plant, these are 22 and 25%, respectively. Since the method of making up lost capacity depends on the situation of a utility, considerable effort has been placed on testing the effects of using different methods of replacing lost capacity at high ambient temperatures by purchased energy. The results indicate that the optimization is very sensitive to the method of making up lost capacity. It is, therefore, important to do an accurate representation of all possible methods of making up capacity loss when optimizating power plants with dry cooling towers. A solution for the problem of losing generation capability by a power plant due to the use of a dry cooling tower is to supplement the dry tower during the hours of peak ambient temperatures by a wet tower. A separate wet/dry cooling tower system with series tower arrangement was considered in this study, and proved to be an economic choice over all-dry cooling where some water is available but supplies are insufficient for a totally evaporative cooling tower

1979-01-01

170

A construction method of reinforced-concrete very high stacks and natural draft cooling towers  

International Nuclear Information System (INIS)

The new Shimizu flex-lip system was developed by the Shimizu Construction Co., Ltd. for constructing very high (about 200 m) towers made of reinforced concrete. Utilizing this system, towers of any shape, circular, triangular, square and polygonal, can be constructed. The wall thickness can be varied from 200 mm to 1 m. The diameter of towers can be enlarged from 3 m to any valve and the inclination of tower walls can be designed in any way between +1/5 and -1/5. The advantage of this system is to use the jack down mechanism, to test concrete strength without sampling, to reduce the connections of reinforcing steel bars and to adopt the continuous, and to use automatic measuring system using laser for checking up positional error. The design and analysis of high tower structures were systemized and automated with the development of the flex-lip construction method. The several past records of having applied this method to industrial areas are shown. As for natural draft cooling towers, the Shimizu jump-up system has been studied for the cooling water capacity of 60,000 m3/h. The towers are 120 m high, 110 m in diameter at the bottom and 65 m in diameter at the top. The advantage of this construction method, the plan of concrete jump-up and the construction test are explained. (Nakai, Y.)

1978-01-01

171

Numerical analysis of crosswind effect on wet cooling tower aerodynamic field  

International Nuclear Information System (INIS)

Based on CFD code FLUENT, three-dimensional numerical analyses were carried out for natural draft wet cooling tower under crosswind conditions.Sensitivity analyses to parameters such as ambient crosswind velocity profile and water droplet equivalent diameter validated the adopted numerical model. The effect of crosswind on wet cooling tower inner and outer aerodynamic field and tower internal heat and mass transfer performance were investigated numerically. The results show that crosswind causes the increase of air inflow relative departure degree and induces horizontal air mass flow rate which improves rain zone heat and mass transfer but reduces tower vertical air mass flow rate, and then produces an unfavorable effect on fill zone and increases outflow water temperature. The analyses about air inflow relative departure degree show that improving the air inflow aerodynamic field can reduce the unfavorable effect of crosswind on the circumference distribution of air inlet air radial velocity and then improve the total cooling performance of wet cooling tower under crosswind conditions. (authors)

2008-12-01

172

Efficient anti-icing arrangements for cooling towers  

International Nuclear Information System (INIS)

This paper described difficulties of operation of cooling towers under icing conditions. Current designs for deicing or preventing icing are examined and recommendations for improvement of the current designs are presented. The addition or reorienting of pipelines,spray nozzles and dampers to prevent icing is discussed

1990-09-01

173

Effects of wet cooling towers on weather and climatic conditions  

International Nuclear Information System (INIS)

Type and efficiency of the occuring process are treated in connection with the important external conditions. The description of the direct effects and the indirect as well leads to the conclusion that thorough investigations of environmental influences by wet cooling towers have to be carried out in a few particular cases only. (orig.)

1976-10-28

174

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

175

Emission of a natural-draught wet cooling tower and flow conditions at the brim of the cooling tower  

International Nuclear Information System (INIS)

Between July 1973 and September 1974, measurements were carried out around a natural-draught wet cooling tower during different weather conditions. The results of these measurements are to serve as basic material for the calculation of plume diffusion. (orig./TK)

1975-01-01

176

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)

1984-10-03

177

Cooling tower drift: experiment design for comprehensive case study  

International Nuclear Information System (INIS)

A drift experiment program to develop a data base which can be used for validation of drift deposition models has been formulated. The first field effort is designed for a suitable mechanical-draft cooling tower to be selected after site visits have been conducted. The discussion here demonstrates the importance of characterizing the droplet size spectrum emitted from the tower and to accurately account for droplet evaporation, because the downwind droplet deposition patterns and near-surface airborne concentrations are extremely sensitive to these parameters

1978-08-01

178

Construction of a 146m height stay-structured cooling tower  

International Nuclear Information System (INIS)

Construction of cooling tower for 300 MW NPP with the THTR-300 type reactors has been described. Dry stay-structured cooling tower with capacity 31700 m3/hr is designed for water cooling from 38.4 to 26.5 deg C under the pressure of 10.1 kPa and at the environment temperature 12 deg C. The assessed period of operation is 50 years. The tower height is 146 m and the foundation diameter is 141 m. The construction is designed for wind loading exceeding by a factor of 1.5 the loading 1550 H/m2 in the areas of the smallest transverse cross section. Under the loading the fluidity limit, corresponding to relative elongation of element of 0.02%, will not be surpassed in any of the steel elements. A central ferroconcrete pylon 180 m high and 6.6 m in diameter serves as the tower support. One upper and two intermediate rings are suspended to the pylon by ropes. To the upper ring the stay-structured net is fixed, which is lined from the inner side with corrugated sheets 1 mm thick; the lining area is 38000 m2. As compared with conventional cooling towers the one described is less metal-consuming (approximately 30%), it is characterized by increased resistance of structure to wind and seismic loadings, increased plant completeness of its elements, and it can be erected not using cranes

1984-01-01

179

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

180

Magnetic fluid conditioning system allows 3000 ppm hardness without cooling tower scale buildup  

International Nuclear Information System (INIS)

Big Three Industries, a manufacturer of compressed and liquefied atmospheric gases, operates a large production complex in Bayport, TX which recirculates 100,000 gpm cooling water. Due to regulatory agency guidelines, high costs, and limited effectiveness of conventional chemical treatment methods, Big Three was in need of a treatment method to prevent corrosion and scaling in recirculating water cooling systems. In December 1983 a magnetic fluid conditioner (MFC) was installed in the pump discharge piping of one cooling tower at Bayport. The patented MFC is an 18'' long spool pipe fitted with uranium-based alloy magnets. The MFC has no moving parts and requires no chemicals, external power source, or maintenance. The MFC is designed so that the fluid is accelerated through a magnetic field. The high velocity of the fluid causes nucleation of the salts in the fluid. The salts are separated from the water by precipitation. During eighteen months of using the MFC, the cooling tower has concentrated in excess of 50 cycles. Conductivity is in excess of 10,000 micromhos, and total hardness (CaCO_3) is above 4000 ppm with pH stabilized between 8 and 9. However, inspections have revealed clean surfaces. The cleaner metal surfaces within the cooling water system provide better heat transfer which has resulted in reduction of tower blowdown, makeup water requirements, and pumping costs. Associated savings will enable the MFC to achieve payback in two and a half years

1985-01-01

 
 
 
 
181

Magnetic fluid conditioning system allows 3000 ppm hardness without cooling tower scale buildup  

Energy Technology Data Exchange (ETDEWEB)

Big Three Industries, a manufacturer of compressed and liquefied atmospheric gases, operates a large production complex in Bayport, TX which recirculates 100,000 gpm cooling water. Due to regulatory agency guidelines, high costs, and limited effectiveness of conventional chemical treatment methods, Big Three was in need of a treatment method to prevent corrosion and scaling in recirculating water cooling systems. In December 1983 a magnetic fluid conditioner (MFC) was installed in the pump discharge piping of one cooling tower at Bayport. The patented MFC is an 18'' long spool pipe fitted with uranium-based alloy magnets. The MFC has no moving parts and requires no chemicals, external power source, or maintenance. The MFC is designed so that the fluid is accelerated through a magnetic field. The high velocity of the fluid causes nucleation of the salts in the fluid. The salts are separated from the water by precipitation. During eighteen months of using the MFC, the cooling tower has concentrated in excess of 50 cycles. Conductivity is in excess of 10,000 micromhos, and total hardness (CaCO/sub 3/) is above 4000 ppm with pH stabilized between 8 and 9. However, inspections have revealed clean surfaces. The cleaner metal surfaces within the cooling water system provide better heat transfer which has resulted in reduction of tower blowdown, makeup water requirements, and pumping costs. Associated savings will enable the MFC to achieve payback in two and a half years.

Szostak, R.J.; Toy, D.A.

1985-08-01

182

Economic and technical assessment of the desiccant wheel effect on the thermal performance of cross flow cooling towers in variable wet bulb temperature  

Science.gov (United States)

Performance improvements of cross flow cooling towers in variable wet bulb temperature were performed. A conventional mathematical model is used to predict desiccant wheel effect on the performance of cooling tower. It is found that by using optimum parameters of desiccant wheel, the inlet air wet bulb temperature into the cooling tower would decrease more than 6 °C and outlet water temperature would decrease more than 4 °C.

Banooni, Salem; Chitsazan, Ali

2014-05-01

183

Cooling tower make-up water treatment plant from the chemical and biological point of view. Kuehlturmzusatzwasser-Aufbereitungsanlagen aus chemischer und biologischer Betrachtungsweise  

Energy Technology Data Exchange (ETDEWEB)

Since most natural waters contain hydrogen carbonates as well as alkaline earth metal ions, this causes disturbances in the cooling water circuit due to temperature rise, aeration and thickening of the water. This leads to precipitation of calcium carbonates which diminish the heat transfer in the heat exchangers. Consequently, in many cases the raw water must be decarbonized. This paper considers in particular decarbonization by the addition of lime in accordance with the flocculation drop procedure. (orig.)

Krabbe, H.J. (Vereinigte Elektrizitaetswerke Westfalen AG, Hauptlaboratorium, Dortmund (Germany)); Pietsch, M. (Landeshygieneinstitut Mecklenburg-Vorpommern, Schwerin (Germany)); Werner, H.P. (Landeshygieneinstitut Mecklenburg-Vorpommern, Schwerin (Germany))

1993-07-01

184

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

185

Numerical modeling of cooling tower plumes: comparison with experiments  

International Nuclear Information System (INIS)

This chapter compares mathematical models designed to study the impact of cooling tower plumes from a nuclear power plant in France. The 3 models are an integral model for a statistical evaluation of plume characteristics and their cumulative effect (reduction of insolation); a spectral microphysical model, to study the interaction processes between a natural cloud and the plume; and a 3D plume model, involving both dynamics, microphysics and their coupling, to investigate the problems of plumes development, especially in convective situations (cumuli formation). Experimental data were obtained near the BUGEY nuclear power plant (two units of 900 MWe, two natural draft cooling towers per unit). The three models currently used are compared to the experimental data. Includes 3 tables and 3 drawings

1984-01-01

186

Effects of wet cooling towers on weather and climate  

International Nuclear Information System (INIS)

According to all the facts known until now, it may be stated that with the current cooling powers up to about 3,000 MW, the waste heat released through wet cooling towers results in no disadvantageous consequences for the environment. This is also valid for the concentration of several cooling towers of comparable size. Small changes of individual meteorological elements in the immediate neighborhood can no more be considered a hazard for the environment than negligible increases of temperature and rainfall in large cities and industrial agglomerations, known since a long time ago. It therefore seems justified to no longer consider the waste heat emission of large cooling towers set up in a flat, well ventilated terrain as an important part in the official licensing procedure and to carry out the time-consuming efficiency calculations only in individual cases or with especially unfavorable ground conditions. Climatic effects of a larger extent cannot be excluded if by application of higher cooling powers and concentration of groups of power stations the energy supply to the atmosphere occurs on larger areas and with higher vertical energy flows. Until now, the long-term effects on the regional climate which may arise as a consequence of the vapor release of a larger number of wet cooling plants by a change of the low-energy radiation conversion in the atmospheric boundary layer, cannot be assessed. By this mechanism lasting changes of the temperature level, the atmospheric stratifications, and the cloud climatology will be possible by means of variations of the conditions of insulation and emission of radiation. (orig./HP)

1977-05-01

187

Improved operating characteristic of dry cooling towers by partial precooling of the air  

International Nuclear Information System (INIS)

In thermal power plants operating with dry cooling towers there is a loss of output at high air temperatures. If this loss is to be reduced by a hybrid system it is logical to utilize the usually restricted quantity of water available at the highest possible thermodynamic efficiency. The method proposed aims to achieve this by precooling a portion of the air flow with water and causing only this portion to act on the coldest part of the heat exchange surface. (Auth.)

1981-01-01

188

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

189

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

190

Distribution of chromium in vegetation and small mammals adjacent to cooling towers  

International Nuclear Information System (INIS)

Surface contamination of vegetation by aerosol pollutants and subsequent ingestion by grazing vertebrates is a pathway for incorporation of toxic elements into food chains. Small mammals (herbivores) were live-trapped in a fescue-dominated field adjacent to large, mechanical draft cooling towers comparable to those utilized by power generation facilities. Cooling waters of the towers contain a chromate, zinc-phosphate compound to inhibit corrosion and fouling within the cooling system. A fraction of the cooling water becomes entrained within the exit air flow and is deposited as drift on the landscape. Resident mammals are chronically subjected to increased chromium exposures through both ingestion and inhalation pathways. Concentrations in vegetation ranged from 342 to 15 ppM at 15 and 130 meters down wind. Concentration levels in litter exceeded those of live plant materials by a factor of 5. Chromium distribution in mammals adjacent to the cooling towers is compared by organ analyses to corresponding organs and tissues of mammals collected remote from drift. Concentrations of chromium in pelt, hair, and bone of animals trapped near the cooling towers were significantly higher (P is less than 0.01) than tissues from control animals. Air concentrations ranged from 15 to 8 ?g/m3 at 15 and 100 meters, and thus provided a potential pathway for increased chromium levels through inhalation. Biological accumulation and retention following ingestion are discussed in a subsequent paper in this symposium (Van Hook et al.). Elevated levels of hexavalent chromium in air have been identified as a potential health hazard. Pathological studies of lung tissues were performed and were negative for lesions. (U.S.)

1975-05-12

191

N3S-AERO. A multidimensional model for numerical simulation of flows in cooling towers  

International Nuclear Information System (INIS)

In order to obtain a better estimation of thermal efficiency as well as a good description of local phenomena in cooling towers, a specific version of EDF's industrial finite element code N3S, denoted N3S-AERO, has been developed for the simulation of flows in cooling towers. It allows to model obstructed zones by directional head losses tensors and fans using their characteristic curves. A single model might include up to 20 towers (with their components - e.g. anti-freeze system - and their environmental exterior domain) in al kinds of configuration (counter flows with recuperators or with rain zones, cross flows, or any combination). The present paper describes the governing equations for air and water flows as well as the numerical algorithms used. Validation is carried out on some configurations of cooling tower in 2D and 3D geometries, showing the ability of N3S-AERO to predict major physical phenomena. Global results on thermal performance are compared with results of the 1D code TEFERI or experimental data when available. Further validation is underway to achieve finer comparison with experimental data for large industrial configurations. (author)

1998-01-01

192

New wet and dry cooling tower for plume abatement; Shingata hakuen boshi reisuito  

Energy Technology Data Exchange (ETDEWEB)

Newly developed cooling tower uses a fill that allows both wet and dry operations. The fill is arranged in all-wet lines, which at all times let warm water through for cooling, and wet-and-dry lines, which in summer let warm water through for cooling but, during plume abatement operation, reject hot water and serve as an air heating zone. In the new cooling tower, all-wet operation letting warm water through the wet-and-dry lines in summer shifts in winter to plume abatement operation in the dry section not letting water through. All-wet lines and wet-and-dry lines are arranged at a rate of 3:1-5:1, out of which a design ratio is chosen best for plume abatement under given weather condition. During the plume abatement operation, the air warmed in the dry section and the saturated wet air through the all-wet section mix upon leaving the fill for a fall in relative humidity so that no supersaturation will occur even when cooled by the ambient air and that no plume will be generated. Various tests are conducted and it is shown that the plume abatement function based on the heat transfer theory performs successfully. 13 figs., 4 tabs.

Toyoyama, M.; Miura, T.; Goto, O. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

1997-11-01

193

BOD limit in synfuel plants' cooling-tower makeup  

Energy Technology Data Exchange (ETDEWEB)

A model cooling tower/trickling filter was used to study acceptable BOD level in wastewater reuse as cooling system makeup and the effect on the system biofouling. Tap water was used to makeup for evaporation and blowdown while phenol solution was metered as the contaminant, into the circulating water. The phenol was degraded in the tower with less than 2 ppM in circulation at equivalent makeup concentrations below 1200 mg BOD/L. The rate of biofouling, measured by heat transfer coefficient, was correlated with phenol loading rates. Makeup concentrations below 1000 mg BOD/L gave low fouling rates while concentration above 1200 mg BOD/L resulted in intolerable fouling of exchanger tubes.

Aiyegbusi, O.; Goldstein, D.J.

1982-01-01

194

The Worlds First Ever Cooling Tower Acceptance Test Using Process Data Reconciliation  

International Nuclear Information System (INIS)

The cooling capacity of cooling towers is influenced by multiple constructive and atmospheric parameters in a very complex way. This leads to strong variations of the measured cold-water temperature and causes unacceptable unreliability of conventional acceptance tests, which are based on single point measurements. In order to overcome this lack of accuracy a new approach to acceptance test based on process data reconciliation has been developed by BTB Jansky and applied at a nuclear power plant. This approach uses process data reconciliation according to VDI 2048 to evaluate datasets over a long period covering different operating conditions of the cooling tower. Data reconciliation is a statistical method to determine the true process parameters with a statistical probability of 95% by considering closed material-, mass-and energy balances. Datasets which are not suitable for the evaluation due to strong transient gradients are excluded beforehand, according to well-defined criteria. The reconciled cold-water temperature is then compared, within a wet bulb temperature range of 5 deg. C to 20 deg. C to the manufacturer's guaranteed temperature. Finally, if the average deviation between reconciled and guaranteed value over the evaluated period is below zero, the cooling tower guarantee is fulfilled. (authors)

2006-07-17

195

Wind induced vibrations of reinforced concrete cooling tower shells  

International Nuclear Information System (INIS)

Natural draught cooling towers are shell structures subjected to random vibrations due wind turbulence. The random response may be analyzed using a spectral approach nad assuming a linear elastic behaviour of the structure. Coupling between the different modes of vibration has to be taken into account. The excitation is given in terms of spectra and cross-spectra of the pressure fluctuations on the shell surface which are related to the spectrum of wind turbulence. The results show in particular that the resonant part of the response remains small even under unfavourable conditions. (Author)

1978-04-20

196

A method to estimate the ageing of a cooling tower  

International Nuclear Information System (INIS)

This paper deals with cooling towers ageing. Our contribution is a method to determine which part of on site measured strain we are able to predict by means of simulations. As a result, we map a gap indicator on the structure. Calculations have been performed in three configurations. Comparing the values obtained in the three cases helps to determine which researches are worth to be done. Indeed, gap indicator reveals that: - THM can not be considered as the main and only ageing mechanism, so long as tower older than 10 years are examined. At least creep has to be taken into account too; - Gap indicator is sensitive to initial hydration conditions. Drying process before bringing into service should be estimated properly, taking into account the different construction steps; - Comparing different thermal conditions reveals that meteorological conditions have a significant influence on results. So, it will be interesting to differentiate the sunny and the shaded part of the tower when the measurements are done; - A large part of the values obtained can be explicated by construction defects. A study on this particular problematic seems to be essential. The four items mentioned must be considered as perspectives to improve the present method of simulations. (authors)

2006-09-18

197

Development of a wet cooling tower with small capacity for the use in solar cooling systems; Entwicklung eines offenen Nasskuehlturms kleiner Leistungsklasse. Fuer den Einsatz in Systemen zum Solaren Kuehlen  

Energy Technology Data Exchange (ETDEWEB)

The following article presents the development of a small-capacity wet cooling tower optimized for the use in small-scale solar cooling systems. The cooling tower has a cooling capacity of 23 kW{sub th} at a wet bulb temperature of 21 C, water inlet/outlet temperatures of 35/27 C and a water flow rate of 2.5 m{sup 3}/h. The power consumption at these operation conditions is 190 W{sub el}. Compared to existing cooling tower models a reduction of volume, footprint and maximum power consumption could be achieved. (orig.)

Wiegand, E.; Kohlenbach, P. [Phoenix SonnenWaerme AG, Berlin (Germany); Kuehn, A.; Petersen, S.; Ziegler, F. [TU Berlin (Germany). Inst. fuer Energietechnik

2005-10-01

198

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

2006-08-01

199

A study on the counter-flow cooling tower performance analysis using NTU-method  

Energy Technology Data Exchange (ETDEWEB)

The thermal performance of cooling towers is affected by the temperature of inlet water, wet bulb temperature of entering air and water-air flow rate. In this study, the effects of these variables are simulated using NTU-method and experimentally investigated for the counter-flow cooling towers. The simulation program to evaluate these variables which affect the performance of cooling tower was developed. The maximum errors between the results of simulations and experiments were 3.8% under the standard design conditions and 5.4% under the other conditions. The performance was increased up to 46 {approx} 50% as the water loading was increased from 6.8 m{sup 3}/hr{center_dot}m{sup 2} to 15.9 m{sup 3}/hr{center_dot}m{sup 2}. The range was reduced up to 56 {approx} 42% when the wet bulb temperature of the entering air was increased from 22 degree C to 29 degree C. 9 refs., 10 figs.

Kim, Y.S.; Seo, M.K.; Lee, S.K. [Pukyong University, Pusan (Korea)

1999-09-01

200

Noise radiation from natural-draft cooling towers for nuclear power plants  

International Nuclear Information System (INIS)

A procedure for computing the noise levels in the vicinity of natural-draft cooling towers is presented. The noise levels are computed in overall and octave band levels with A-weighting and with no weighting. Attenuation of the noise by wave spreading, atmospheric absorption, barrier screening, vegetation, and wind and temperature gradients are included. The procedure is applied to a nuclear power plant served by four cooling towers and to a nuclear energy center with forty cooling towers

1975-01-01

 
 
 
 
201

the effect of design changes of cooling tower on the performance of ETRR-2 reactor  

International Nuclear Information System (INIS)

the egyptian testing and research reactor(ETRR-2) were established in 1998 with maximum power 22 MW for research purposes. two induced draft cooling towers with different specifications was installed inh the system, a replaced (old) cooling tower was in operation from 1998 to 2003, and the present (new) cooling tower was in operation from 2003 till now. the reactor was put into operation since 1998 but it faced a lot of problems in the cooling system concerning with the thermal load dissipation. some efforts guided to study this problem to evaluate the old and present cooling tower to decide if the present cooling tower achieves a good performance in the reactor cooling system and to know why the old cooling tower have to be replaced ? and to avoid thermal problems in the future to satisfy the stable operation. in this work the study of the cooling system of the ETRR-2 is presented. this study is based on analytical, numerical and measurement investigations of the cooling system following three parts. he first part depicts the analytical solution of integrated cooling system of the reactor, the second part depicts the numerical solution of the cooling tower packing , and the third part is the evaluation of the cooling system using cooling technology, institute procedure (CTI)

202

Analysis of the new cooling tower in Šoštanj on temperature action  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this graduation thesis, the influence of temperature action on the new cooling tower in Šoštanj is analyzed. The temperature load is defined according to guideline VGB-R 610 e, izdaja 2010.In the first part of work, general specifications of the new cooling tower in Šoštanj are presented. The plot of the shell of the cooling tower by using Mathematica is given. In second part of thesis we determine temperature action on the new cooling tower in Šoštanj according to VGB-R 610 e, izdaj...

2013-01-01

203

Two-phase Euler-Lagrange CFD simulation of evaporative cooling in a Wind Tower  

Energy Technology Data Exchange (ETDEWEB)

A new design of Wind Tower is investigated numerically under different structural parameters and environmental conditions. The new design is some wetted columns, consisting of wetted curtains hung in the tower column, which are modeled as surfaces that inject droplets of water with very low speed. The CFD open source package - Open FOAM - is used. The current three-dimensional CFD simulation has adopted both the Eulerian approach for the air phase and the Lagrangian approach for the water phase. The effects of water droplet diameter and water droplet temperature on the thermal performance of the Wind Tower are investigated at specific inlet air velocity and relative humidity and height of wetted columns. Also, the effects of wind velocity, temperature, and relative humidity inlet to Wind Tower are studied. Changing the height of the wetted columns and its effect on the evaporative cooling in other specific parameters is studied. The results obtained from the present CFD study are compared with the analytical data taken from the literature and a good agreement is observed. As a result, the height of 10 m of wetted columns decreases 12 K of the ambient air temperature and increases 22% of its relative humidity. (author)

Saffari, Hamid; Hosseinnia, S.M. [Department of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran)

2009-09-15

204

Development of FRP structural frame for industrial cooling tower  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the specific feature of the FRP (fiberglass reinforced plastic) cooling tower structural frame, and reports on the strength tests and test results with a full scale model. The developed FRP structural frame is characterized by its low maintenance cost corresponding to about 4 to 5% of the initial construction cost, lighter weight being 15 to 20% less than that of conventional wooden structural frame, higher structural reliability due to adoption of rivet connection, and so on. From the results of buckling strength test of the member, it was shown that there is a good agreement between theory and experiment. From the results of bearing strength test, it was found that bearing strength is somewhat reduced with increasing number of rivets. In addition, the paper describes the weatherproof and waterproof of the FRP structural frame member. From the results of strength test of the structural frame, it was presumed that failure of riveted joint occurs prior to the buckling of the column. Through the application to actual structural frame of cooling tower, the validity of design method was confirmed. 5 refs., 13 figs., 3 tabs.

Kato, K.; Ando, K.; Oya, H.; Hamamoto, A. (Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)); Mochizuki, K. (Ishikawajima Plant Engineering and Construction Co. Ltd., Tokyo (Japan)); Yabumoto, H.; Fujita, K. (Nippon Shokubai Co. Ltd., Tokyo (Japan))

1993-10-01

205

Towards safe and economic seismic design of cooling towers of extreme height  

International Nuclear Information System (INIS)

Nuclear power plants are being increasingly equipped with natural draught cooling towers of heights greater than 160 m. In many arid zones, where high natural draught cooling towers with dry cooling systems are being projected, wind loads are relativelly small while site seismicity is relatively high. Thus the ability of the tower to withstand earthquake induced forces governs its design. On the other hand, most reinforced concrete cooling towers of extreme height built so far were designed to withstand high wind loads and moderate earthquake loads. The effects of special structural measures for obtaining an economic design, such as the introduction of ring stiffened shells, have been studied mainly for those towers. In view of the previous aspects it is the purpose of this paper to analyze the effects of various structural measures and other parameters on the seismic response of such high cooling towers. (orig.)

1979-08-21

206

Operational cost minimization in cooling water systems  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

207

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 m"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"6 fibres per m"3, or 100 ng/m"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"3 of air; including the extreme data of the single sample mentioned above, the result is some thousand fibres per m"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"6 fibres per m"3. (orig.)

1985-01-01

208

Available new technology to improve cooling tower long term performance, revisited  

Energy Technology Data Exchange (ETDEWEB)

Electric generating stations throughout the world have their condenser cooling provided by a variety of different cooling tower designs, or are on an open cycle system which may even have a cooling tower. Achieving continuously the best possible performance from these cooling towers impacts generating capacity. Newly developed components are available today, which are designed to improve the efficiency and dependability of the cooling tower. These new components include fill, distribution nozzles, drift eliminators and fans. This paper covers: Analyzing the area of efficiency loss; establishing the performance baseline; discussion of new components available to improve long term performance. This includes fill media, nozzles, and fans; cost comparison examples of the repack benefit; the example will include a comparison of fill types; the upgrading of a large utility cooling tower; the acceptance test; and documentation of the long-term performance improvements of the new fill designed to reduce fouling.

Mirsky, G.R. [Hamon Cooling Towers, Bridgewater, NJ (United States)

1998-12-31

209

Reduction in performance due to recirculation in mechanical-draft cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The influence of recirculating warm plume air on the performance of mechanical-draft cooling towers is investigated analytically, numerically and experimentally. It is shown that the amount of recirculation that occurs is a function of the flow and the thermal and geometric characteristics of the tower. The presence of a wind wall tends to reduce the mount of recirculation. An equation is presented with which the performance effectiveness due to recirculation can be evaluated approximately for a mechanical-draft cooling tower.

Kroger, D.G. (Univ. of Stellenbosch, Dept. of Mechanical Engineering, Stellenbosch 7600 (ZA))

1989-01-01

210

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

211

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

212

Fog and drift deposition from evaporative cooling towers  

International Nuclear Information System (INIS)

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

1975-09-01

213

The investigation of cooling tower packing in various arrangements  

International Nuclear Information System (INIS)

The effect of form with corrugated packing on heat transfer and pressure drop characteristics in atmospheric cooling towers has been studied experimentally. The results showed that the heat transfer coefficient decreased with increase in packing pitch and increase in the ratio of rib pitch to rib height. Friction factors were expressed by a dimensional equation which included pitch and distance between the packings, for both smooth and rough surface. From these results, the relationship between packing heat transfer coefficient and pressure drop was deduced. The correlations were verified with additional experimental data taken with 1.1,P/Dp/e5. This provides a useful semi experimental relation, in the area generally lacking in design and performance data. (author)

1998-01-01

214

Experimental buckling investigations of cooling tower shells under wind load  

International Nuclear Information System (INIS)

The buckling behavior of cooling tower shells under realistic wind loading are investigated. Buckling tests on elastic modells are carried out in a wind-tunnel. As the first step of these tests, the wind-velocity over height and the distribution of the internal and external pressures are measured. After this, the membrane and bending stresses in the shell are measured by means of electrical strain gages and at the same time the critical wind pressure too. Parameters investigated are the wind load and the stiffening by rings, including the effect of the upper edge beam. The effects of the bending moments on the local critical membrane stresses will be determined and the BSS-Approach will be modified. (orig.)

1986-08-01

215

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

216

Successful implementation of ageing management exemplified at the cooling tower of Emsland nuclear power plant  

International Nuclear Information System (INIS)

The present paper describes the successful implementation of the restoration of water-distribution channels at the cooling tower of the Emsland nuclear power plant under the aspect of ageing management. The main challenge of aging management is the determination of potential aging mechanism and to avoid systematically and effectively their damaging influences. In the course of the annual site inspections abnormalities at the lower side of the water-distribution channels of the cooling tower were detected, analysed, and repaired. The extraordinary high chlorine equivalent of the cooling water was identified as main reason of the damages located. Due to extensive infiltration into the concrete structure, chloride-induced corrosion generates a volume expansion of the reinforcement and thereby to a blast off of the concrete covering. According to the restoration concept, the damaged concrete was removed by maximum pressure water jet blasting; where necessary the reinforcement was retrofitted and a layered concrete substitution was applied by synthetic cement mortar. The realised procedures conserve the load bearing reinforcement only for a certain period, because the permanent chloride infiltration could not be stopped. Therefore, the structure has to be monitored permanently. (orig.)

2013-07-01

217

Atmospheric impacts of natural-draft cooling tower emissions: a case history  

Energy Technology Data Exchange (ETDEWEB)

The Power Authority of the State of New York is currently involved in State regulatory proceedings concerning a proposed 700-MW coal-fired unit to be located on Staten Island in New York State. This facility incorporates a 122-m (400-ft) natural-draft cooling tower that will use saline makeup water from the Arthur Kill, an estuarine water body. This paper will describe atmospheric impact issues that have been encountered with special emphasis on those raised during the New York regulatory hearings. 8 refs.

Vigeant, S.A.; Cramer, J.J.; Mazzola, C.A.; Rao, K.

1980-01-01

218

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

International Nuclear Information System (INIS)

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

2010-04-01

219

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

220

Energy and exergy analysis of a co current gas cooling tower based on mathematical modeling and simulation results  

International Nuclear Information System (INIS)

Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and enthalpy of gas and liquid streams are predicted along the tower length and are used in order to calculate the energy and exergy efficiencies. The model validity in prediction of gas and liquid characteristics changing along the tower length was examined against some operating data measured in a commercial cement plant. As a result, it was concluded that in spite of high energy efficiency, the cooling tower has a relatively low exergic efficiency which is because of thermodynamic irreversibilities and entropy production during heat and mass transfers. Also, the effect of some operating parameters including tower diameter, tower length, liquid drops size distribution and water flow rate was investigated on amount of exergy destruction. In all cases the results showed that the exergy of water does not completely absorbed by gas and a notable portion of the exergy is destructed. The result of these investigations may be employed to inform about the true energy potential caring by fluids

2008-05-01

 
 
 
 
221

Cooling tower for industrial installations such power stations  

International Nuclear Information System (INIS)

The hot water cooler has a large structure over which the hot water flows, spread from dispersers above, with a collecting basin below for the cooled water. Air is drawn laterally over the cooler structure from outside to the interior. The structure transverse vertical horizontal top section efficiency decreases from outer to inner, whilst the bottom section efficiency profile is reversed. The intermediate section averages between the two. 2 figs

1992-02-26

222

Seasonality of cooling tower drift in vegetation at ORGDP (Oak Ridge Gaseous Diffusion Plant)  

International Nuclear Information System (INIS)

Cooling tower operation at the Oak Ridge Gaseous Diffusion Plant (ORGDP) requires the addition of a chromated corrosion inhibitor to the recirculating cooling water (RCW) system. Fluctuations in the RCW flow rates of the ORGDP cooling towers correlate with operational levels of the enrichment plant. Drift fraction is a function of the RCW flow rate, with variations in chromium deposition reflected in vegetation contamination. Fescue grass and litter were collected in the plant environs along a distance gradient, during different seasons, and analyzed for chromium. Foliar chromium concentrations were maximum during the winter months, decreasing in spring and summer months at 13 m as the demand for cooling decreased with lower plant operations. In contrast, concentrations in litter increased with time. The accumulation of chromium in the litter component was likely related to more exchange sites associated with increased litter biomass due to the seasonal senescence of foliage, whereas decreased accumulations on foliage reflected high mobility of the drift residue due to leaching and a short lifespan of individual leaves. In addition to operational considerations, the data illustrate the importance of seasonal considerations in the use of biological materials in a monitoring program. (author)

1983-01-01

223

Proximity of the home to a cooling tower and risk of non-outbreak Legionnaires' disease.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVE--To study the source of non-outbreak legionnaires' disease, particularly the role of cooling towers, by comparing the locations of patients' homes in relation to the location of cooling towers. DESIGN--Retrospective, descriptive study of a case series of patients with legionnaires' disease ill between 1978 and 1986 and, for comparison, a case series of patients with lung cancer. A prospectively developed register and interview based survey provided data on the location of cooling to...

Bhopal, R. S.; Fallon, R. J.; Buist, E. C.; Black, R. J.; Urquhart, J. D.

1991-01-01

224

The Merkel coefficient and its dependence on the temperature position of the cooling tower process  

International Nuclear Information System (INIS)

The Merkel coefficient, or evaporation coefficient, is still being used as a characteristic factor for the cooling tower process. Its dependence on the cooling range or on the warm water temperature of the process is often considered a disadvantage of the theory of evaporation cooling. This is also the reason for the suggestion to change the theory in such a way that the Merkel coefficient becomes independent of the temperature. The present investigation, however, leads to the result that the dependence of the Merkel coefficient on the temperature must be considered as a remarkable confirmation for the evidence of the theory of heat and mass transfer, as the experimental statements agree fully with the results of the theoretical considerations. (orig.)

1977-10-01

225

Cooling water demand of the electric power industry  

International Nuclear Information System (INIS)

The cooling water demand of thermal power stations exceeds all other demands in water management in the Federal Republic of Germany. The heat adsorption capacity of lakes and streams is exhausted by flow cooling systems. Evaporation losses will therefore accelerate due to expansive application of cooling towers. Quantitive gauging at power revealed higher losses than hitherto assumed. (orig.)

1981-01-01

226

COMPARISON OF MODEL PREDICTIONS AND CONSUMPTIVE WATER USE OF CLOSED CYCLE COOLING SYSTEMS  

Science.gov (United States)

The report gives results of a comparison of field-data-derived water evaporation rates with predictive model values for cooling towers and cooling ponds at steam-electric generating plants. The Leung Moore cooling tower model and five cooling pond models (Harbeck and Marciano; Ha...

227

Exergy transfer and parametric study of counter flow wet cooling towers  

International Nuclear Information System (INIS)

A thermodynamic analysis of the counter flow wet cooling tower (CWCT) is performed in this paper. Both energy and exergy formulations are developed and validated for the system. Four types of exergy transfer processes occurring inside the CWCT are investigated schematically. A parametric study is conducted under various operating conditions in order to investigate the effects of thermal efficiency and water-to-air ratio on the exergy performance of the CWCT. Unlike past studies, the transiting exergy contained in the inlet and outlet water is not considered. It is found that the exergy efficiency is always less than 25%. The exergy parameters including evaporation water loss, exergy efficiency, exergy input, internal and external exergy losses are very sensitive to the thermal efficiency when it is very close to 1.0 at lower water-to-air ratios. - Research highlights: ? We model counter flow wet cooling towers and make a detailed exergy analysis. ? Four types of exergy transfer processes are investigated schematically. ? Only a small part of exergy input, less than 25%, is effectively utilized.

2011-04-01

228

Analysis, synthesis and optimization of complex cooling water systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cooling water systems are used to remove excess heat from a chemical process to the atmosphere. The primary components of these systems are the cooling tower and the heat exchanger network. There is a strong interaction between these individual components, thus their performances are interrelated. Most published research in this area has focused mainly on optimization of the individual components i.e. optimization of heat exchanger network or optimization of the cooling towers. This approach ...

Gololo, Khunedi Vincent

2013-01-01

229

Systems for mixing partial air flows in a wet/dry cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Almost 100% intermixture of both wet and dry air flows in a wet/dry cooling tower can be attained by selecting an appropriate mixing system. The capital costs required for this and the higher operating costs incurred because of the mixing process have no significant effect on the total capital and operating costs of the wet/dry cooling tower. Efficient mixing contributes to the benefit that wet/dry cooling towers can be designed to operate with a lower excess of dry air, which leads to a more economic plant.

Ruscheweyh, H.; Vodicka, V.

1980-09-01

230

Static Limit Load of a Deteriorated Hyperbolic Cooling Tower  

International Nuclear Information System (INIS)

Irregular concrete erosion due to atmospheric and industrial effects is assessed by a layer model of reinforced concrete shells by simply removing the deteriorated layers. Concrete tension strength and fracture energy become very important properties in these circumstances since reinforcement bars are locally ineffective. A material model for cracking reinforced concrete is suggested and an application is presented to the ultimate load analysis of a natural draught cooling tower. Both geometric and material non-linearities are accounted for. In particular, the geometric instability is identified in the process of incremental wind load (static loading) which occurs locally due to the loss of cross-section and degradation of concrete strength. Strain softening in concrete is significant in this context since the associated cross-section stiffness decrease affects the limit load. The finite element model and material models of concrete and reinforcement enable reliable deterministic limit load analysis. The ratio of the limit load to actual service load thus obtained is about 1.5. The actual safety margin can only be assessed by a stochastic reliability analysis. This is intended using the Hasofer-Lind reliability index. (authors)

1999-09-01

231

Numerical modelling of cooling tower plumes: comparison with experimental data  

International Nuclear Information System (INIS)

To validate the numerical models of cooling tower plumes used in impact studies, EDF has effected a major testing program in the vicinity of the BUGEY nuclear power station, including sets of fine measurements taken from aircraft, teledetection readings and routine measurements effected over a very period (photographs of plumes, micro-meteorological network). The data recorded have allowed two types of models to be validaded: 1) The aim of the first type is to establish statistics of the morphological characteristics of plumes (length, height, etc.) and the resulting micro-climatic changes (i.e. reduction of the duration of sunshine and attenuation of the intensity of overall radiation. This type of model was validated on the basis of the routine measurements carried out over a long period. 2) The second type (a three - dimensional model and a microphysical model of the spectrum), mainly designed for the study of the dynamic and thermodynamic structure of plumes, has been validated on the basis of measurements made during intensive measurements campaigns (formation of artificial cumulus, interaction of the plume with a cloud formation)

1982-01-01

232

Radiometric modeling of mechanical draft cooling towers to assist in the extraction of their absolute temperature from remote thermal imagery  

Science.gov (United States)

Determination of the internal temperature of a mechanical draft cooling tower (MDCT) from remotely-sensed thermal imagery is important for many applications that provide input to energy-related process models. The problem of determining the temperature of an MDCT is unique due to the geometry of the tower and due to the exhausted water vapor plume. The radiance leaving the tower is dependent on the optical and thermal properties of the tower materials ( i.e., emissivity, BRDF, temperature, etc.) as well as the internal geometry of the tower. The tower radiance is then propagated through the exhaust plume and through the atmosphere to arrive at the sensor. The expelled effluent from the tower consists of a warm plume with a higher water vapor concentration than the ambient atmosphere. Given that a thermal image has been atmospherically compensated, the remaining sources of error in extracted tower temperature due to the exhausted plume and the tower geometry must be accounted for. A temperature correction factor due to these error sources is derived through the use of three-dimensional radiometric modeling. A range of values for each important parameter are modeled to create a target space (i.e. , look-up table) that predicts the internal MDCT temperature for every combination of parameter values. The look-up table provides data for the creation of a fast-running parameterized model. This model, along with user knowledge of the scene, provides a means to convert the image-derived apparent temperature into the estimated absolute temperature of an MDCT.

Montanaro, Matthew

233

A model for autumn outbreaks of Legionnaires' disease associated with cooling towers, linked to system operation and size.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cooling towers have been demonstrated to be amplifiers and disseminators of legionella, the causative organism of Legionnaires' disease. Community outbreaks associated with cooling towers have been reported with several common factors. Small towers (< 300 kW) have predominantly been implicated in outbreaks. Cooling tower-associated outbreaks are most frequent in autumn, and frequently implicated systems have been operated after a period of shutdown. This paper reports field study data relatin...

Bentham, R. H.; Broadbent, C. R.

1993-01-01

234

Cooling water distribution system  

Science.gov (United States)

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

235

Structural inspection and wind analysis of redwood cooling towers at the Portsmouth Gaseous Diffusion Plant  

International Nuclear Information System (INIS)

As part of the plant upgrade program, structural analyses and field inspections were performed on four redwood cooling towers at the DOE Portsmouth gaseous diffusion plant located in Piketon, Ohio. The cooling towers are categorized as important hazard facilities. The loadings are derived from UCRL-15910 according to the pertinent hazard category. In addition to the seismic and wind loadings, the wood cooling towers are constantly subject to adverse environmental effects such as elevated temperature, chemical attack, icing and snow load, and motor vibrations. A thorough structural evaluation for all load combinations was performed for each of the cooling towers based on the structural code requirements of the Cooling Tower Institute and National Forest Products Association. Most stress criteria are unique for the redwood material. This evaluation was performed using finite element techniques on the global structural integrity and supplemented by hand calculations on the individual connection joints. Overloaded wood structural members and joints are identified by the analysis. The rectangular tower structure sits on a concrete basin that span across 60 ft by 200 ft. A major part of the cooling towers upgrading program involved field inspections of the individual cells of each tower. The primary purpose of these inspections was to identify any existing structural damage or deficiencies such as failed members, degraded wood, and deficiencies resulting from poor construction practice. Inspection of 40 cells identified some generic deficiencies that mostly are consistent with the analytical finding. Based on the analysis, some effective but inexpensive upgrading techniques were developed and recommended to bring the cooling towers into compliance with current DOE requirements

1991-10-15

236

On the optimum performance of forced draft counter flow cooling towers  

International Nuclear Information System (INIS)

A thermo-hydraulic performance optimization analysis is presented, yielding simple algebraic formula for estimating the optimum performance point of counter current mechanical draft wet cooling towers. The effectiveness-Ntu method is used in the present study, together with the derivation of psychometric properties of moist air based on a numerical approximation method, for thermal performance analysis of wet cooling towers of the counter flow type

2004-09-01

237

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

International Nuclear Information System (INIS)

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

238

Experimental study of the influence of atmospheric conditions on the performance of natural draft dry cooling towers  

International Nuclear Information System (INIS)

The heat dissipation of cooling towers is influenced by atmospheric conditions. In order to establish these influences EIR conducted measurements on a natural draft dry cooling tower. During two measuring campaigns with a duration of total 10 weeks the performance of the cooling tower, the ambient air temperatures, the wind velocities and directions as well as air temperature at the top of the tower and in front of the heat exchangers were continuously measured and registered. The results achieved enable the quantitative description of the influence of the ambient air temperature, wind and temperature inversion on the performance of natural draft dry cooling towers. (Auth.)

1977-01-01

239

A coherent set of design and control means for large wet cooling towers  

International Nuclear Information System (INIS)

Electricite de France operates, or has under construction, thirty large cooling towers for the 900, 1300 and 1400 MW nuclear power units. A review is given of the various problems posed by the design and control of these towers, as well as a description of the means employed (computer codes, test-benches, control methods and on-site measurement) to resolve them: global optimization of the power unit heat sink, cooling tower thermal design, shell design and calculation principles, hydraulic sizing, thermal operation study, vapor plume calculation, noise emission calculation and performance control. A bibliography of the main reports published on these subjects is given

1990-09-01

240

POWER PLANT COOLING SYSTEM WATER CONSUMPTION AND NONWATER IMPACT REPORTS  

Science.gov (United States)

This study dealt with water evaporation and consumption of power plant cooling systems and evaluated six simple generic evaporation prediction models, one for cooling towers and five for cooling ponds/lakes using field data provided by twelve utilities. Also evaluated in the stud...

 
 
 
 
241

Methodology for evaluation of cooling tower performance - Part 1: Description of the methodology  

International Nuclear Information System (INIS)

Highlights: ? New methodology for evaluation of CT performance is presented. ? It enables to study impacts of local irregularities in CT on plant's power output. ? Poppe model for applications on the local basis of CTs is presented. ? Empirical model connecting cooling water temperature with power output is derived. ? Study is based on measured data from a plant and natural draft CT. - Abstract: A methodology for the evaluation of a natural draft cooling tower (CT) that is a part of a power plant is proposed. In this work the connection between CT performance and power output is established. The methodology consists of three subparts, i.e. Cooling Tower Profiler (CTP) method, CT model and model of a power plant. In the first part of the paper the three subparts of the methodology are described. Focus is given to the empirical model of the plant and a new application of the Poppe model. The simple empirical model enables accurate prediction of the power increase as a function of cooling water temperature and load to the plant. On the other hand, Poppe governing equations were derived for application on the local basis of CT. Moreover, the constraints and assumptions of CT analysis are discussed. The methodology is presented on real data from the power plant and CT. This is the base for application of the methodology presented in the second part of the paper where the focus is given on minimizing the error of the methodology. A small area with irregularities is analyzed and results are reported. Furthermore, a simplified computational approach to solving the Poppe equations is proposed yielding faster calculation with preserved accuracy.

2011-10-01

242

Reinforced concrete column- supported by hyperboloid cooling tower stability assessment for seismic loads  

International Nuclear Information System (INIS)

In recent years, the use of larger reinforced concrete column-supported hyperboloid cooling towers has been increased significantly. Thus, the investigation on failure criteria for structural components of such structures under different loads has been found as an essential need. Construction of cooling towers in seismic zones initiated the study on the dynamic behavior of such structures due to seismic loads. In this paper, finite element analyses have been performed to obtain the stress concentration, nonlinear behavior, stability or safety factor of the R. C. tower due to earthquakes loads. Outcomes of the study show that considerable plastic hinges were created in the X shape long columns of the R.C. hyperboloid cooling tower due to seismic loads, which resulted in a significant decrease in the stability safety factor and, an increase in concerns

2005-01-01

243

Three-dimensional numerical calculations of flow and plume spreading past cooling towers  

Energy Technology Data Exchange (ETDEWEB)

The paper reports on the application of an existing three-dimensional computer code to the calculation of the flow and temperature field past cooling towers. The code uses a rectangular grid so that the round tower geometry has by approximated by steps. Simulations are presented of various idealized laboratory studies carried out with cylindrical cooling tower models with the ratio of plume exit to cross-wind velocity varying in the range 0.2 to 1.7 and the densimetric Froude number in the range {infinity} to 2. By comparison with the experimental results it is shown that the computer model is capable of reproducing the main features of the complex flow and temperature field past cooling towers including the downwash effect at strong cross winds. The quantitative agreement is not always entirely satisfactory, and suggestions are made for improving the computer model.

Demuren, A.O.; Rodi, W. (Univ. of Karlsruhe (West Germany))

1987-02-01

244

A new practical index for calcium carbonate scale prediction in cooling tower systems  

International Nuclear Information System (INIS)

Some calcium carbonate scaling indexes are shown to be ineffective an inaccurate in concentrated cooling tower water at pH levels above 7.5. In addition, there is a misunderstanding by many water treatment vendors on the use of the indexes. This has resulted in confusion by both end-users and vendors. More importantly, these indexes are shown to be inaccurate and ineffective for calcium carbonate scale prediction. This paper reviews many of the available indexes, the basis for their calculations, how they compare, and which are effective in cooling water systems. The development of a new index was started over 10 years ago and has been verified in operating systems. Since most cooling water treatment programs now operate at a pH level above 7.5 and as high as 9+, the index provides a more accurate and practical estimation of calcium carbonate scaling tendencies. Case histories are provided to show a comparison with other indexes, such as the Ryznar and Langelier indexes

1991-01-01

245

Assessment of cooling tower (ultimate heat sink) performance in the Byron individual plant examination  

International Nuclear Information System (INIS)

A time-dependent model of the Byron Nuclear Generation Station safety-related cooling towers has been developed for use with the Byron PRA (IPE). The model can either be run in a stand-alone program with externally supplied heat loads, or can be directly coupled into MAAP (Modular Accident Analysis Program). The primary feature of the model is a careful tracking of the basin temperature through the progression of different severe accidents. Heat removal rates from containment, both from containment fan-coolers and the residual heat removal system, are determined by the feed-back of this time-varying return temperature. Also, the inventory of the basin is tracked in time, and this is controlled by make-up, evaporative losses due to the heat load supplied to the towers, and the possibility of unsecured blowdown. The model has been used to determine the overall capabilities and vulnerabilities of the Byron Ultimate Heat Sink (UHS). It was determined that the UHS is very reliable with respect to maintaining acceptably low basin temperatures, requiring only at most two of eight operating cooling tower fans. Further, when the two units have their Essential Service Water (ESW) systems cross-tied, one of four ESW operating pumps is sufficient to handle the loads from the accident unit with the other unit proceeding to an orderly shutdown. The major vulnerability of the Byron UHS is shown to be the ability to maintain inventory, although the time-scales for basin dry-out are relatively long, being eight to twenty-one hours, depending upon when blowdown is secured. (author)

1994-04-05

246

Considerations required for the optimal design of a wet/dry cooling tower, under aspect of minimising visible vapour  

International Nuclear Information System (INIS)

Combined wet/dry cooling towers are to-day already available, using conventional materials for the wet and dry part. The investigations on the various arrangements on the air and water sides show the advantage of parallel arrangement on the air side and of the series arrangement on the water side. The size of the plant can be reduced by incorporating NTB elements. The use of closed systems with outside spray is also discussed, and prototype plants described. - It still remains to investigate the calculation of the visible vapour in respect of length, lifting height, density and transparency, as well as to determine the allowed physical values for the dimensioning of the combined wet/dry cooling towers. (orig.)

1976-10-01

247

Contributions to the theory of wet- and wet/dry cooling towers. Beitraege zur Theorie des Nass- und Nass-Trocken-Kuehlturms  

Energy Technology Data Exchange (ETDEWEB)

The present progress report contains the papers presented at a cooling-tower symposium held by invitation of Carl Munters-Euroform GmbH u. Co. KG on 2/26/1980 at Aachen. They deal with acute problems of cooling-tower theory, namely: Flow in cooling towers, mass transfer at cooling by evaporation, natural-chaff wet-type cooling towers as heat and mass exchangers with free convection, mist formation in wet-type cooling towers and its influence on the cooling capacity, wet/dry (hybrid) cooling towers and their vapor plumes.

1981-01-01

248

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

249

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

250

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

251

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

International Nuclear Information System (INIS)

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.

2010-06-01

252

Performance analysis of heat transfer processes from wet and dry surfaces : cooling towers and heat exchangers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of this work is to study the thermal and hydraulic performance of evaporatively cooled heat exchangers, including closed wet cooling towers, and dry tube heat exchangers with various geometries. Applications utilising such equipment exist in almost every thermal process. The investigation includes theoretical analysis, computational approaches, and experimental measurements. In this work, a computational model is presented for the thermal performance of closed wet cooling to...

Hasan, Ala Ali

2005-01-01

253

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

2008-10-01

254

N3S-AERO: a multidimensional model for numerical simulation of all wet cooling tower systems  

International Nuclear Information System (INIS)

3D model is more required to optimize the design of new cooling tower by way of parameters studies, to improve the performance of the existing ones from changes in fill zone or water distribution. Therefore, the Directions des Etudes et Recherches with collaboration of the Direction de l'Equipement of EDF, has developed a specific version of the finite element CFD code N3S, denoted N3S-AERO, for the simulation of natural or mechanical draught wet cooling towers. It solves mass, momentum, heat and humidity averaged Navier-Stokes equations including buoyancy terms with variable density for air flow in the whole domain mass, heat equations for water flow in exchange zones. With standard results of N3S as air velocity and scalar fields, N3S-AERO gives in return water temperature fields mean values of variables at inlet or outlet of each exchange zone and thermal performance of the tower. 2D axisymmetrical and 3D industrial cases have soon been done. Major flow phenomena are well predicted and averaged cold water values are in good agreement with ID-TEFERI code or measurements

1997-01-01

255

Successful implementation of ageing management exemplified at the cooling tower of the Emsland nuclear power plant; Erfolgreiche Umsetzung von Alterungsmanagement am Beispiel Kuehlturm des Kernkraftwerks Emsland  

Energy Technology Data Exchange (ETDEWEB)

The paper describes the successful implementation of the restoration of water distribution channels at the cooling tower of the Emsland nuclear power plant under the aspect of ageing management. The main challenge of ageing management is the determination of potential ageing mechanism and to avoid systematically and effectively their damaging influences. In the course of the annual site inspections, abnormalities at the lower side of the water-distribution channels of the cooling tower were detected, analysed, and repaired. The procedures conserve the load bearing reinforcement only for a certain period. Therefore permanent structural monitoring is needed. (orig.)

Fischer, Alexander [Hochtief Solutions AG, Consult IKS Energy, Frankfurt am Main (Germany). Design Kraftwerke; Dueweling, Carsten [Kernkraftwerke Lippe-Ems GmbH, Lingen (Germany). Abschnitt Bautechnik

2013-09-01

256

System approach to calculated grounding of reliability of new designs for cooling towers with metal frame  

International Nuclear Information System (INIS)

Dealt with are the methods of the system approach to reliable grounding of new design features of cooling towers with the metal frame. The new design of prestressed ferroconcrete shells is presented. It provides considerable saving in specific amount of material per structure and labor input for manufacturing. The problems to be solved by the researchers, designers builders and operating staff are stated on the basis of the system approach. Successful solution of these problems will provide reliability of the structure. An example of the system approach to the design of a guy rope cooling tower is given

1990-09-01

257

Simultaneous prediction of internal and external aerodynamic and thermal flow fields of a natural-draft cooling tower in a cross-wind  

International Nuclear Information System (INIS)

The quantitative simulation of cooling-tower performance is useful to designers, enabling them to make optimal choices regarding: the type, volume and shape of the packing (i.e. fill); and the shape and size of the tower. In order to simulate performance realistically, non-uniformities of distribution of water and air mass-flow rates across the tower radius must be taken into account. This necessitates at least 2D modeling; and in order to establish the influence of a cross-wind, boundary conditions must be far away from the tower inlet and outlet, and 3D modeling must be performed. This paper is concerned with large wet natural-draught cooling towers of the type used in many steam power stations for cooling large quantities of water by direct contact with the atmosphere. The aim of the present work has been to improve the procedures of calculation by using numerical integration of the heat and mass transfer equations, and to connect internal and external aerodynamics thus enabling wind influence to be studied. It permits predicting the performance of a proposed design of the tower over a range of operating conditions. PHOENICS, a general-purpose computer code for fluid-flow simulation, is used to provide numerical solutions to governing differential equations

1989-04-01

258

Earthquake Response of Axisymmetric Tower Structures Surrounded by Water.  

Science.gov (United States)

A general method for linear analysis of response of axisymmetric towers, partly submerged in water, to earthquake ground motion is presented. Based on results of the first part of this investigation in which the basic mechanism of structure-water interact...

A. K. Chopra C. Y. Liaw

1973-01-01

259

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

260

Wind tunnel experiments on cooling tower plumes: Part 1 - In uniform crossflow  

Energy Technology Data Exchange (ETDEWEB)

Measurements of velocity and temperature field and flow visualization results are reported for an ideal case of a cooling-tower plume in the presence of a uniform crossflow for various velocity ratios, densimetric Froude numbers, and Reynolds numbers. As the Reynolds number increases, turbulent structures appear, which have vorticity of the same sign as the partner vortices in the low Reynolds number case. The measurements showed that there is a strong interaction between the bending plume or jet and the wake of the cooling tower, which is basically responsible for the downwash effect. The latter is generally quite strong at low velocity ratios and high Reynolds numbers. High turbulence intensities are produced in the wake of the tower for a distance of 6 to 8 diameters. The plume is diluted faster as the velocity ratio increases and buoyancy decreases. In the wake region of the stack dilution increases with increased buoyancy.

Andreopoulos, J. (City Univ. of New York, New York (United States))

1989-11-01

 
 
 
 
261

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

262

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

2007-02-01

263

Transition to a new generation of large natural-draught cooling towers  

International Nuclear Information System (INIS)

A concept of a new generation of natural-draught cooling towers for large nuclear power plant units is presented considering optimization and calculation methods, safety philosophy, dimension criteria, constructional measures, building materials, construction surveying, climbing formwork, and climbing cranes. The first installation will be available by 1990, with a unit 250 m in diameter by 150 m high

1985-01-01

264

TESTING AND ANALYSIS OF A WET-DRY CROSSFLOW COOLING TOWER, VOLUME II: APPENDICES  

Science.gov (United States)

The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acousti...

265

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

266

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

1978-08-01

267

Some observations on modelling the mechanical-draft cooling tower plume at Plant Gaston  

Energy Technology Data Exchange (ETDEWEB)

Observations on the far-field time mean condensed plumes from the twin mechanical-draft cooling towers at the Gaston Steam Plant, Wilsonville, Alabama taken during February 1975 and January-February 1976 are compared with a one-dimensional integral model for moist plume behaviour. Empirical modifications are required to account for the near-field effects of downwash, source geometry, wind direction relative to tower alignment and the far-field effects of vertical and wind direction shear on plume behaviour. Details on source and ambient parameters are given.

Slawson, P.R.

1982-01-01

268

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

1989-04-01

269

Cooling tower for industrial installations such power stations  

International Nuclear Information System (INIS)

The hot water cooler has a large structure over which the hot water flows with a collecting basin below, for the cold water. Air is drawn laterally over the cooler structure from outside to the interior. The structure is formed from groups of tubes inside which cold water circulates. The structure has, in vertical section, an upper horizontal layer in which the efficiency decreases from the outside to the inside, a lower horizontal layer in which the efficiency decreases from the inside to the outside and an intermediate layer with intermediate efficiency. 2 figs

1992-06-18

270

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

271

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.

2012-06-01

272

Organization and technology of cooling tower construction for the Novyi Angren state regional electric power plant  

Energy Technology Data Exchange (ETDEWEB)

Describes in detail the design, construction and quality control procedures of the first phase of water supply towers (towers 1 and 2 completed in 1984 and 1986). These towers (of which there will eventually be 4) are 130 m high, with a capacity of 70 thousand m/sup 3//h, maximum internal diameter at the 10 m mark is 99.1 m, external diameter of upper reinforcing ring at the 130 m mark is 62.5 m, maximum and minimum wall thickness is 970 and 160 mm and each tower will work in conjunction with 2,300 MW power units. The location of the power plant means that special requirements are levied on the concrete tower shells regarding strength (due to risk of earthquakes), frost resistance and waterproofness. A special concrete containing SVK, a by-product of the production of Kapralaktam from toluene, was developed to meet this requirement by the Gidrospetsproekt institute (which also developed special self-lifting scaffolding to erect the towers used in conjunction with I-500 special lifts). Tests on the concrete revealed it to have a strength of 32-36 MPa.

Shigil' cheva, I.A.; Okishev, N.D.; Tadzhiev, Eh.M.

1987-09-01

273

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

274

Experience with the construction of the cable net cooling tower at Schmehausen  

International Nuclear Information System (INIS)

The static system of the cooling tower consists of a concrete column 181 metres high from which a 145 meter high cable with a base diameter of 141 metres is suspended and tensioned. The cable net is covered on the inside with aluminium sheeting. Banks of tubes, which constitute the actual coding system, are arranged in the form of rings around the column in a self-supporting structure. Of the very wide range of problems which occurred in the construction of this cooling tower, the following are discussed in the paper: 1) Stressing of the concrete column during the construction period. 2) Stiffening the net using separation rings. 3) Net connection points on the ring foundation. 4) Control of the cable forces and the cable net geometry. 5) Start of sheeting erection. (orig.)

1977-03-01

275

Reliability Analysis of Cooling Towers: Influence of Rebars Corrosion on Failure  

International Nuclear Information System (INIS)

Natural-draught cooling towers are used in nuclear power plants as heat exchangers. These structures are submitted to environmental loads such as wind and thermal gradients that are stochastic in nature. A probabilistic framework has been developed by EDF (Electricite de France) for assessing the durability of such structures. In this paper, the corrosion of the rebars due to concrete carbonation and the corresponding weakening of the reinforced concrete sections is considered. Due to the presence of time in the definition of the limit state function associated with the loss of serviceability of the cooling tower, time-variant reliability analysis has to be used. A novel approach is proposed to take into account the random 'initiation time', which corresponds to the time necessary for the carbonation to attain the rebars. Results are given in terms of the probability of failure of the structure over its life time. (authors)

2002-04-14

276

Meteorological effects of the mechanical-draft cooling towers of the Oak Ridge Gaseous Diffusion Plant  

International Nuclear Information System (INIS)

The mechanical-draft cooling towers at the Oak Ridge Gaseous Diffusion Plant dissipate about 2000 MW of heat. Downwash occurs about 40 percent of the time, when wind speeds exceed about 3 m/sec. An elevated cloud forms about 10 percent of the time. The length of the visible plume, which is typically 100 or 200 m, is satisfactorily modeled if it is assumed that the plumes from all the cells in a cooling-tower bank combine. The calculation of fog concentration is complicated by the fact that the moisture is not inert but is taking part in the energy exchanges of a thermodynamic system. Calculations of drift deposition agree fairly well with observations

1975-09-01

277

From large natural draft cooling tower shells to chimneys of solar upwind power plants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Natural draft cooling towers (NDCTs) presently form the world-largest RC shell structures, solar updraft power plants (SUPPs) will do this in future. The paper starts with explanations of the working principles of NDCTs and SUPPs. In industrialized countries with strong legal emphasis on sustainable power production technologies, NDCTs are widely spread, while SUPPs represent future solar power generation concepts in the worldżs tropical areas, using solar irradiation as power plant fuel. Co...

2009-01-01

278

Methodology for evaluation of cooling tower performance - Part 2: Application of the methodology and computational aspects of Poppe equations  

International Nuclear Information System (INIS)

Highlights: ? Application of the methodology for evaluation of CT performance is presented. ? Proposed is calculation procedure that minimizes systematic error of applied models. ? Faster numerical integration of Poppe equations is presented. ? Study is based on measured data from a plant and natural draft CT. ? Significance of efficient CT operation and its impact on power output are depicted. - Abstract: A methodology for evaluation of natural draft cooling tower (CT) performance and its application is presented. The study establishes the connection between CT performance and power output. It can estimate a change in a CT's efficiency as well as an increase in power output as a function of cooling water temperature and load to the plant. The methodology consists of three subparts, i.e. Cooling Tower Profiler (CTP) method, CT model and a model of the power plant that are described in the first part of the paper. The second part focuses on application of the methodology in a way that minimizes error of the CT model. One week of data from the power plant were acquired for the analysis. In the CT a small area with irregularities was examined, and increased efficiency and power output are estimated by the methodology. Furthermore, another aspect of solving Poppe equations is examined resulting in reduced computational effort by approximately a half without losing any computational accuracy.

2011-10-01

279

The Water Quality Control of the Secondary Cooling Water under a Normal Operation of 30 MWth in HANARO  

International Nuclear Information System (INIS)

HANARO, a multi-purpose research reactor, a 30 MWth open-tank-in-pool type, has been under a full power operation since 2005. The heat generated by the core of HANARO is transferred to the primary cooling water. And the cooling water transfers the heat to the secondary cooling water through the primary cooling heat exchanger. The heat absorbed by the secondary cooling water is removed through a cooling tower. The quality of the secondary cooling water is deteriorated by a temperature variation of the cooling water and a foreign material flowing over the cooling water through the cooling tower fan for a cooling. From these, a corrosion reduces the life time of a system, a scale degrades the heat transfer effect and a sludge and slime induces a local corrosion. For reducing these impacts, the quality of the secondary cooling water is treated by a high ca-hardness water quality program by maintaining a super saturated condition of ions, 12 of a ca-hardness concentration. After an overhaul maintenance of a secondary cooling tower composed of a secondary cooling system in 2007, a secondary cooling water stored in the cooling tower basin was replaced with a fresh city water. In this year, a water quality deterioration test has been performed under a full power operation and a mode of a twenty three day operation and twelve day maintenance for setting a beginning control limit of the secondary cooling water. This paper describes the water quality deterioration test for the secondary cooling system under a full power operation of 30 MWth including a test method, a test requirement and a test result

2008-10-01

280

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

 
 
 
 
281

Evaluation of coatings and mortars for protection of concrete cooling tower structures from microbiologically influenced corrosion in geothermal power plants.  

Science.gov (United States)

Microbiologically influenced corrosion (MIC) is a common problem that causes deterioration of concrete in cooling towers used in geothermal power plants. MIC can be attributed to a number of different types of bacteria, particularly sulphur oxidizing and ...

M. L. Allan

1999-01-01

282

A model for radionuclide transport in the Cooling Water System  

Energy Technology Data Exchange (ETDEWEB)

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.

Kahook, S.D.

1992-08-01

283

A model for radionuclide transport in the Cooling Water System  

International Nuclear Information System (INIS)

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

284

Waste-heat vertical tube foam evaporation for cooling tower blowdown renovation/recycle. Project summary report  

Energy Technology Data Exchange (ETDEWEB)

A prototype waste-heat vertical tube foam evaporation (WH-VTFE) plant was designed, constructed, and field-tested for reducing power plant cooling tower blowdown to a small residual volume of solids slurried in brine, while producing distilled water for reuse. Facility design was based on previously-developed pilot plant test data. The WH-VTFE facility was constructed for initial parametric testing in upflow/downflow evaporation modes with boiler steam. The field test/demonstration phase was conducted at a power plant site using turbine exhaust steam for the up to 50-fold cooling tower blowdown concentration in a foamy-flow seed-slurried mode of downflow vertical tube evaporation. The VTFE heat transfer coefficient ranged between 5600 to 9000 W/sq m/degree, over 4-fold the level considered as acceptable in another study. Further, a sufficient temperature difference is available within a typical power plant heat rejection system to operate a WH-VTFE when the plant load is above 50% of its design capacity. Scale formed from inadequate brine recycle rates was readily removed by recycling fresh water through the evaporator to restore the high heat transfer performance of the WH-VTFE. It was concluded that WH-VTFE was demonstrated as feasible and commercially viable.

Sephton, H.H.; Someahsaraii, K.

1982-02-01

285

Operating experience with a wet/dry cooling tower for 150 MW thermal output in the BASF company  

Energy Technology Data Exchange (ETDEWEB)

Wet cooling towers can lead to damage and functional problems with engineering equipment within their range of propagation due to vapour formation. In BASF investigations have been carried out to discover whether adverse effects of this kind on the production plant can be avoided by the use of a wet/dry hybrid cooling tower. The results of these investigations are described and the various capital costs and expenditure on energy consumption are indicated.

Kokott, D.

1983-12-01

286

Prediction of ground vibration due to the collapse of a 235 m high cooling tower under accidental loads  

International Nuclear Information System (INIS)

Highlights: ? Ground vibration due to the collapse of a huge cooling tower was predicted. ? Accidental loads with different characteristics caused different collapse modes. ? Effect of ground vibration on the nuclear-related facilities cannot be ignored. -- Abstract: A comprehensive approach is presented in this study for the prediction of the ground vibration due to the collapse of a 235 m high cooling tower, which can be caused by various accidental loads, e.g., explosion or strong wind. The predicted ground motion is to be used in the safety evaluation of nuclear-related facilities adjacent to the cooling tower, as well as the plant planning of a nuclear power station to be constructed in China. Firstly, falling weight tests were conducted at a construction site using the dynamic compaction method. The ground vibrations were measured in the form of acceleration time history. A finite element method based “falling weight-soil” model was then developed and verified by field test results. Meanwhile, the simulated collapse processes of the cooling tower under two accidental loads were completed in a parallel study, the results of which are briefly introduced in this paper. Furthermore, based on the “falling weight-soil” model, “cooling tower-soil” models were developed for the prediction of the ground vibrations induced by two collapse modes of the cooling tower. Finally, for a deep understanding of the vibration characteristics, a parametric study was also conducted with consideration of different collapse profiles, soil geologies as well as the arrangements of an isolation trench. It was found that severe ground vibration occurred in the vicinity of the cooling tower when the collapse happened. However, the vibration attenuated rapidly with the increase in distance from the cooling tower. Moreover, the “collapse in integrity” mode and the rock foundation contributed to exciting intense ground vibration. By appropriately arranging an isolation trench, the ground vibration can be significantly reduced

2013-05-01

287

Drift-modeling and monitoring comparisons. [Drift from power plant cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Congress is looking into the conglomeration of nuclear reactors into energy centers of limited area. Drift from cooling towers can corrode and damage structures in the immediate vicinity of the towers, cause a public nuisance if located near parking lots or high-density traffic areas, and endanger local vegetation. The estimation of salt deposition has relied primarily on predictions from a variety of models, with very few direct measurements. One of the major efforts in our program is to evaluate the assumptions, limitations, and applicabilities of various analytical models for drift deposition prediction. Several drift deposition models are compared using a set of standard input conditions. The predicted maximum drift deposition differs by two orders of magnitude, and the downwind locations of the maximum differ by one order of magnitude. The discrepancies are attributed mainly to different assumptions in the models regarding the initial effective height of the droplets. Current programs in which drift characteristics at the tower mouth and drift deposition downwind of the tower are being measured are summarized. At the present time, drift deposition measurements, sufficiently comprehensive for model verifications, are unavailable. Hopefully, the Chalk Point Program will satisfy this need.

Chen, N.C.J.; Hanna, S.R.

1977-01-01

288

Wind tunnel experiments on cooling tower plumes part I: In uniform cross flow  

Energy Technology Data Exchange (ETDEWEB)

Measurements of velocity and temperature field and flow visualization results are reported for an ideal case of a cooling-tower plume in the presence of a uniform cross flow for various velocity ratios, densimetric Froude numbers, and Reynolds numbers. Coherent structures in the form of jet-like, wake-like or mushroom type of vortices have been observed. The type of the structures depends primarily on the velocity ratio. As the Reynolds number increases turbulent structures appear, which carry vorticity of the same sign as the partner vortices in the low Reynolds number case. The measurements showed that there is a strong interaction between the bending over plume or jet and the wake of the cooling tower which is basically responsible for the downwash effect. The latter is generally quite strong at low velocity ratios and high Reynolds numbers. High turbulence intensities are produced in the wake of the tower for a distance 6 to 8 diameters. The plume is diluted faster as the velocity ratio increases and buoyancy decreases. In the wake region of the stack dilution increased with buoyancy.

Andreopoulos, J.

1987-01-01

289

Rehabilitation of two natural draught cooling towers at Grohnde 1300 MW nuclear power station, taking into account a completely new concept  

International Nuclear Information System (INIS)

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.)

1992-08-01

290

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

291

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

292

Federal role in dry and wet-dry cooling tower research, development, and demonstration  

Energy Technology Data Exchange (ETDEWEB)

It is concluded that it is appropriate for the Energy Research and Development Administration (or its successor) to sponsor a program of fiscal, technical and management support directed at providing a commercial advanced concept wet/dry (or dry) cooling technology for electric utility use within ten years. This federal role is thought to be appropriate for several reasons, including: the need for such technology, although expected to grow only slowly at first, will eventually be quite widespread; wet/dry and dry cooling tower technology is currently available, but successful development of an advanced concept should produce significant cost savings for this component of power plant costs; established cooling tower vendors do not appear to have sufficient research dollars available to support a program of the magnitude planned by ERDA, although at least one non-vendor advanced concept development project is underway; the Electric Power Research Institute (EPRI), the State of California and potentially other entities have expressed a willingness to support the ERDA program with significant funds, but state that they cannot assume complete funding at this time; and even without the shared funding mentioned above, the ERDA program is expected to produce discounted public and/or private industry benefits in excess of its costs.

1977-09-01

293

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

International Nuclear Information System (INIS)

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)

2006-03-27

294

Analysis of the new cooling tower in Šoštanj on wind actions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this Graduation Thesis the wind action on the new cooling tower in Šoštanj is considered. The procedure for determining wind loads is described in detail according to guideline VGB-R 610 e, 2010 edition and standard SIST EN 1991-1-4:2005. A comparison of different procedures for determining wind actions is made. For analysis a computer program SAP2000, v12.0.0 is used and there are two models with different number of finite elements. Several types of analysis are used - linear static ana...

2013-01-01

295

The influence of cooling towers and topography on the dispersion of stack discharges  

International Nuclear Information System (INIS)

The paper describes the experimental methods (aerodynamic tunnels) used to study the effects of site topography and cooling towers and their plumes on the atmospheric dispersion of releases. The results of experimental studies carried out at a number of nuclear power station sites in SWITZERLAND, GERMANY and BELGIUM are presented and used to draw out certain general rules concerning these effects. A method is proposed for modifying the atmospheric dispersion parameters accordingly. The results obtained are compared with those of other research workers in the field

1980-07-01

296

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

297

Minimization of corrosion using activated sodium bromide in a medium-size cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The cooling tower at the Albermarle Process Development Center in Baton Rouge, Louisiana, historically used chlorine as a biocide in combination with phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron buildup was a problem in low-velocity, small cross-sectional areas of piping. A general cleanup of the system was performed in April 1995. This cleanup was followed with a switch to a two-component corrosion inhibitor/dispersant package. Alternate biocides were evaluated at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, biological activity reaction tests, and visual observations of the tower sump and heat exchanger surfaces.

Nalepa, C.J.; Moore, R.M.; Golson, G.L. [Albemarle Corp., Baton Rouge, LA (United States); Wolfe, T.W.; Puckorius, P.R. [Puckorius and Associates, Evergreen, CO (United States)

1996-07-01

298

Case study: Minimization of corrosion using activated sodium bromide in a medium-size cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The process loop cooling tower at the Albemarle Process Development Center in Baton Rouge, LA has historically used chlorine as the biocide together with industry accepted phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron build-up was a recurring problem, especially in low-velocity, small cross-sectional areas of piping. A general clean-up of the system was performed in April, 1995. This clean-up was followed with a switch to a two-component corrosion inhibitor/dispersant package. It was decided to study alternate biocides as well at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel while maintaining prior performance on admiralty brass. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, BART (biological activity reaction test) tests, and visual observations of the tower sump and heat exchanger surfaces.

Nalepa, C.J.; Moore, R.M.; Golson, G.L. [Albemarle Corp., Baton Rouge, LA (United States); Wolfe, T.W.; Puckorius, P.R. [Puckorius and Associates, Evergreen, CO (United States)

1996-10-01

299

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

300

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

 
 
 
 
301

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 thr...

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

2009-01-01

302

Comparison of a 2D axisymmetric CFD model of a natural draft wet cooling tower and a 1D model  

Energy Technology Data Exchange (ETDEWEB)

The performance predictions of a simple one-dimensional natural draft wet cooling tower (NDWCT) model and a two-dimensional axisymmetric numerical model are compared under a range of design parameters. The two-dimensional model has the ability to resolve radial non-uniformities across the tower which the one-dimensional model only computes as a bulk averaged value. The difference between the overall cooling range predicted by the two models is generally less than 2%, with no divergence in the agreement between the methods with respect to any design parameter. (author)

Williamson, N.; Armfield, S. [School of Aerospace, Mechanical and Mechatronic Engineering, J07, The University of Sydney, NSW 2006 (Australia); Behnia, M. [Dean of Graduate Studies, The University of Sydney, NSW 2006 (Australia)

2008-05-15

303

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

International Nuclear Information System (INIS)

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.

2010-01-01

304

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

305

Sensitivity study of a method for updating a finite element model of a nuclear power station cooling tower  

International Nuclear Information System (INIS)

The Research and Development Division of Electricite de France is developing a surveillance method of cooling towers involving on-site wind-induced measurements. The method is supposed to detect structural damage in the tower. The damage is identified by tuning a finite element model of the tower on experimental mode shapes and eigenfrequencies. The sensitivity of the method was evaluated through numerical tests. First, the dynamic response of a damaged tower was simulated by varying the stiffness of some area of the model shell (from 1 % to 24 % of the total shell area). Second, the structural parameters of the undamaged cooling tower model were updated in order to make the output of the undamaged model as close as possible to the synthetic experimental data. The updating method, based on the minimization of the differences between experimental modal energies and modal energies calculated by the model, did not detect a stiffness change over less than 3 % of the shell area. Such a sensitivity is thought to be insufficient to detect tower cracks which behave like highly localized defaults. (author). 8 refs., 9 figs., 6 tabs

1994-01-01

306

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

2005-03-01

307

Improve corrosion and deposition control in alkaline cooling water systems  

Energy Technology Data Exchange (ETDEWEB)

Utility operators can use a calcium carbonate inhibitor to improve corrosion control and meet environmental discharge limits for phosphorus on cooling water systems. Due to volume, maintaining cooling towers` operating parameters such as pH, Cl{sub 2}, cycles, etc., are a huge endeavor to balance water chemistry. The goal of a cooling water system is to provide a reliable heat-transfer medium--water--to numerous exchangers without impairing the energy transfer efficiency. Traditionally, alkaline phosphate and alkaline-zinc based programs have been used to control corrosion and minimize scaling of heat-transfer surfaces. However, restrictions on phosphate discharges for water systems are requiring utility operators to seek other water treatment programs. Two case histories show how hydrocarbon processing industry facilities used a calcium carbonate inhibitor to reduce phosphate discharges, control corrosion and maintain heat-transfer efficiency on affected exchangers.

Geiger, G.E. [Betz Water Management Group, Horsham, PA (United States)

1996-01-01

308

Tower-Perturbation Measurements in Above-Water Radiometry  

Science.gov (United States)

This report documents the scientific activities which took place during June 2001 and June 2002 on the Acqua Alta Oceanographic Tower (AAOT) in the northern Adriatic Sea. The primary objective of these field campaigns was to quantify the effect of platform perturbations (principally reflections of sunlight onto the sea surface) on above-water measurements of water-leaving radiances. The deployment goals documented in this report were to: a) collect an extensive and simultaneous set of above- and in-water optical measurements under predominantly clear-sky conditions; b) establish the vertical properties of the water column using a variety of ancillary measurements, many of which were taken coincidently with the optical measurements; and c) determine the bulk properties of the environment using a diversity of atmospheric, biogeochemical, and meteorological techniques. A preliminary assessment of the data collected during the two field campaigns shows the perturbation in above-water radiometry caused by a large offshore structure is very similar to that caused by a large research vessel.

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Zibordi, Giuseppe; Berthon, Jean-Francois; DAlimonte, Davide; vanderLinde, Dirk; Brown, James W.

2003-01-01

309

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

310

GROUND WATER USE FOR COOLING: ASSOCIATED AQUIFER TEMPERATURE CHANGES  

Energy Technology Data Exchange (ETDEWEB)

In steam-electric power plants, large volumes of surface waters are used for cooling the plant's condensers. There, approximately two-thirds of the energy produced by the fuel is removed as waste heat. This heat is carried away by the cooling waters, is dispersed into the atmosphere or surface-water bodies, and is lost for other potential uses. When condenser cooling systems such as towers or ponds are used, there is also a considerable net loss of water through evaporation. Injection and storage of spent cooling waters underground would reduce the evaporative (consumptive) losses to the atmosphere. Later, these waters could be recovered for use in heating and in industrial or agricultural applications. The resulting conservation of energy and water may make such a project economically feasible in the near future as the costs of water and fuel increase. In this paper, we review the use of ground water from a confined aquifer for this application and analyze a simple configuration of one withdrawal and one injection well to determine: (1) the areal extent of temperature changes caused by reinjection of spent cooling waters into the aquifer from which they originated; and (2) how long it would take for the water to become too hot to use for cooling.

Lippmann, Marcelo J.; Tsang, Chin Fu

1980-01-01

311

Performance of indices in cooling water system - a case study  

International Nuclear Information System (INIS)

The corrosion/scale forming tendency of cooling water systems is generally predicted by measuring different saturation indices. For this purpose, indices like Langelier Saturation Index (LSI), Ryznar Stability Index (RSI) and Puckorius Scale Index (PSI) are generally used though many other indices have also been formulated for the same purpose. The main objective of using these indices is to adjust the cooling water chemistry to a non-corrosive condition. The Fast Breeder Test Reactor (FBTR) at Kalpakkam, Tamilnadu, India is a 40 MWt sodium cooled, mixed carbide (uranium and plutonium) fuelled nuclear test reactor. Cooling water system of FBTR comprises of service water system and condenser cooling water systems. Service water system forms the terminal heat sink for various process heat exchangers and steam water system auxiliary coolers. The condenser cooling water (CCW) system caters to main condenser, dump condenser, turbine oil cooler, generator air cooler and condensate cooler. Both the systems share a common induced draft-cooling tower, cooling water pit, corrosion monitoring set up, chlorinator and side stream filtration unit. In FBTR, cooling water system chemistry is maintained by dosing proprietary formulations comprising corrosion inhibitor, inorganic dispersant, bio-dispersant, chlorine activator and biocides along with chlorination. Water indices like LSI, RSI and PSI are being monitored for over a decade. These indices were formulated earlier to predict the corrosion/scaling tendency in the municipal drinking water systems which were not subjected to any kind of chemical treatment. In this paper, the usefulness and applicability of these indices for predicting the corrosion/scale forming tendency of chemically treated cooling water is discussed based on the obtained corrosion and scale data for the period from May 1998 to Dec 2007. (author)

2008-12-01

312

Application of a cloud model to cooling tower plumes and clouds  

International Nuclear Information System (INIS)

A steady-state, one-dimensional cloud model has been modified to simulate the growth of plumes (both wet and dry) and clouds from natural and forced draft cooling towers. The modifications to the cloud model are discussed and comparisons are made betwen predicted height and length of plumes and observed values. A correlation coefficient of 0.78 is achieved for model predictions of plume height and a correlation coefficient of 0.49 for predicted plume length. Comparisons with Benning Road data showed 78% of the model-predicted plume heights were within 50% of the observed height, while 93% of the predicted plume lengths were within 50% of the observed length

1980-01-01

313

Operational issues involving use of supplementary cooling towers to meet stream temperature standards with application to the Browns Ferry Nuclear Plant  

International Nuclear Information System (INIS)

A mixed mode cooling system is one which operates in either the open, closed, or helper (once-through but with the use of the cooling towers) modes. Such systems may be particularly economical where the need for supplementary cooling to meet environmental constraints on induced water temperature changes is seasonal or dependent upon other transient factors such as stream-flow. The issues involved in the use of mixed mode systems include the design of the open cycle and closed cycle portions of the cooling system, the specification of the environmental standard to be met, and the monitoring system and associated decision rules used to determine when mode changes are necessary. These issues have been examined in the context of a case study of TVA's Browns Ferry Nuclear Plant which utilizes the large quantity of site specific data reflecting conditions both with and without plant operation

1979-01-01

314

Cost and performance optimization of natural draft dry cooling towers using genetic algorithm. Paper no. IGEC-1-002  

International Nuclear Information System (INIS)

In this paper the cost - performance optimization of natural draft dry cooling towers with specific kind of heat exchangers, known as Forgo T60 has been investigated. These cooling towers are used in combined and steam cycle power plants. The optimization has been done using genetic algorithm. The objective function has two parts, which are minimizing the cost and maximizing the performance. In the first part the geometrical and operating parameters are defined and for the next part the performance of the designed tower for different ambient temperatures during a year is calculated considering the characteristic curve of the turbine. The applied genetic algorithm has been tuned up using the data of some working power cycles. The results show it is possible to find an optimum for all design parameters; however it is very dependent on how exact the cost analysis is. (author)

2005-06-12

315

Flue gas discharge from cooling towers. Wind tunnel investigation of building downwash effects on ground-level concentrations  

Energy Technology Data Exchange (ETDEWEB)

German power plants are required to meet new emission standards which limit the maximum sulfur dioxide (SO/sub 2/) concentration in flue gas discharges to 400 mgm/sup -3/. To achieve this level of reduction in SO/sub 2/ concentration, wet scrubbing is necessary for large plants using lignite or hard coal. Wet scrubbing results in a significant reduction in the flue gas temperature leading to low effective stack heights. Instead of using stack gas reheating to achieve the plume rise necessary to satisfy local environmental standards, it was proposed to discharge the scrubbed flue gas from the existing natural-draft cooling towers (NDCT). This method should be effective in reducing local ground-level concentrations since NDCT-plumes are typically very buoyant (densimetric Froude number below 1) and normally reach considerable heights of rise. Only under strong wind conditions does the situation reverse itself. For such strong winds, the NDCT-plume is subject to tower and building downwash with the possibility of unacceptably high ground-level concentrations. For a 2700 MW(e) lignite-fired power plant near Cologne, a wind tunnel study was carried out to investigate the effects of tower and building downwash effects on the ground-level concentrations of SO/sub 2/ produced by discharging the scrubbed flue gas from the natural-draft cooling towers. Also, a comparison was made between the ground-level concentrations produced by the cooling tower discharge method and those produced by a traditional stack. It was found that for low and intermediate wind speeds, the ground-level concentrations are lower for the case of the cooling tower discharge. Only for strong winds, which occur only very rarely at most German sites, did the conventional stack discharge appear to be superior. 13 refs.

Schatzmann, M.; Lohmeyer, A.; Ortner, G.

1987-01-01

316

Overall heat transfer coefficient in the presence of the axial dispersion coefficient for a forced draught cooling tower  

Energy Technology Data Exchange (ETDEWEB)

An overall heat transfer coefficient was calculated for a forced draught counterflow cooling tower by using the pulse response technique. The presence of an axial dispersion coefficient for both gas and liquid was considered. Results indicate that, on neglecting the axial mixing and assuming a plug flow, the overall heat transfer coefficient is overestimated and can lead to errors in design applications. (author).

Younis, M.A. (Kuwait Univ. (Kuwait))

317

TESTING AND ANALYSIS OF A WET-DRY CROSSFLOW COOLING TOWER, VOLUME I: TEST PROGRAM AND RESULTS  

Science.gov (United States)

The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acousti...

318

Horizontal cooling towers: riverine ecosystem services and the fate of thermoelectric heat in the contemporary Northeast US  

International Nuclear Information System (INIS)

The electricity sector is dependent on rivers to provide ecosystem services that help regulate excess heat, either through provision of water for evaporative cooling or by conveying, diluting and attenuating waste heat inputs. Reliance on these ecosystem services alters flow and temperature regimes, which impact fish habitat and other aquatic ecosystem services. We demonstrate the contemporary (2000–2010) dependence of the electricity sector on riverine ecosystem services and associated aquatic impacts in the Northeast US, a region with a high density of thermoelectric power plants. We quantify these dynamics using a spatially distributed hydrology and water temperature model (the framework for aquatic modeling in the Earth system), coupled with the thermoelectric power and thermal pollution model. We find that 28.4% of thermoelectric heat production is transferred to rivers, whereas 25.9% is directed to vertical cooling towers. Regionally, only 11.3% of heat transferred to rivers is dissipated to the atmosphere and the rest is delivered to coasts, in part due to the distribution of power plants within the river system. Impacts to the flow regime are minimal, while impacts to the thermal regime include increased river lengths of unsuitable habitats for fish with maximum thermal tolerances of 24.0, 29.0, and 34.0?° C in segments downstream of plants by 0.6%, 9.8%, and 53.9%, respectively. Our analysis highlights the interactions among electricity production, cooling technologies, aquatic impacts, and ecosystem services, and can be used to assess the full costs and tradeoffs of electricity production at regional scales. (letter)

2013-01-01

319

18 CFR 420.44 - Cooling water.  

Science.gov (United States)

... Charges; Exemptions § 420.44 Cooling water. Water used exclusively for cooling purposes which is returned to the...except that losses due to in-stream evaporation caused by cooling uses will be charged as consumptive...

2009-04-01

320

Hydraulic design of a low-specific speed Francis runner for a hydraulic cooling tower  

International Nuclear Information System (INIS)

The air blower in a cooling tower is normally driven by an electromotor, and the electric energy consumed by the electromotor is tremendous. The remaining energy at the outlet of the cooling cycle is considerable. This energy can be utilized to drive a hydraulic turbine and consequently to rotate the air blower. The purpose of this project is to recycle energy, lower energy consumption and reduce pollutant discharge. Firstly, a two-order polynomial is proposed to describe the blade setting angle distribution law along the meridional streamline in the streamline equation. The runner is designed by the point-to-point integration method with a specific blade setting angle distribution. Three different ultra-low-specificspeed Francis runners with different wrap angles are obtained in this method. Secondly, based on CFD numerical simulations, the effects of blade setting angle distribution on pressure coefficient distribution and relative efficiency have been analyzed. Finally, blade angles of inlet and outlet and control coefficients of blade setting angle distribution law are optimal variables, efficiency and minimum pressure are objective functions, adopting NSGA-II algorithm, a multi-objective optimization for ultra-low-specific speed Francis runner is carried out. The obtained results show that the optimal runner has higher efficiency and better cavitation performance.

2012-11-26

 
 
 
 
321

Hydraulic design of a low-specific speed Francis runner for a hydraulic cooling tower  

Science.gov (United States)

The air blower in a cooling tower is normally driven by an electromotor, and the electric energy consumed by the electromotor is tremendous. The remaining energy at the outlet of the cooling cycle is considerable. This energy can be utilized to drive a hydraulic turbine and consequently to rotate the air blower. The purpose of this project is to recycle energy, lower energy consumption and reduce pollutant discharge. Firstly, a two-order polynomial is proposed to describe the blade setting angle distribution law along the meridional streamline in the streamline equation. The runner is designed by the point-to-point integration method with a specific blade setting angle distribution. Three different ultra-low-specificspeed Francis runners with different wrap angles are obtained in this method. Secondly, based on CFD numerical simulations, the effects of blade setting angle distribution on pressure coefficient distribution and relative efficiency have been analyzed. Finally, blade angles of inlet and outlet and control coefficients of blade setting angle distribution law are optimal variables, efficiency and minimum pressure are objective functions, adopting NSGA-II algorithm, a multi-objective optimization for ultra-low-specific speed Francis runner is carried out. The obtained results show that the optimal runner has higher efficiency and better cavitation performance.

Ruan, H.; Luo, X. Q.; Liao, W. L.; Zhao, Y. P.

2012-11-01

322

Unusual Decommissioning of Contaminated Facilities at the Savannah River Site - The Demolition of Cooling Towers 285-H and 285-F  

International Nuclear Information System (INIS)

Savannah River Site is an 800-square kilometer (310-square mile) U.S. Department of Energy (DOE) industrial facility located in Aiken, Allendale, and Barnwell Counties in South Carolina. The site is dedicated to environmental cleanup, developing and deploying technologies to support the cleanup mission, processing and storing nuclear materials, and supporting national security missions. The current focus in environmental management is on the cleanup of legacy materials, facilities and wastes left from the Cold War. In 2002 the DOE initiated actions to expedite cleanup focusing on significant risk reduction coupled with reducing costs. SRS published the Savannah River Site Environmental Management Integrated Deactivation and Decommissioning Plan in 2003 which addressed the final disposition and physical end state of all 1,013 Environmental Management facilities on site by the year 2025. Included in this list of facilities are reactors, fabrication facilities, process facilities and the support facilities that were required during the past 50 years. By the end of FY06, over 200 facilities had been decommissioned. This paper describes the demolition of two facilities, cooling towers 285-H and 285-F that were associated with the operation of the process canyons. Because of the circumstances surrounding these decommissions, unique and unusual techniques were safely employed to demolish and remove the cooling towers. Both 285-H and 285-F were safely felled by pulling the columns remotely to weaken the internal portion of the structure so it would collapse inwards into the basin. Cooling tower 285-H fell in less than 1 second after approximately two-thirds of the columns had been broken. See Figure 3 for a photo of 285-H after its collapse. 285-F, which was larger than 285-H, fell in three sections, two cells at a time. Once the towers were felled conventional demolition equipment was used to segregate and remove the debris. All protective measures used to protect surrounding equipment and structures were successful and the basins were cleaned out and returned to service in less than two weeks. The demolition of both cooling towers 285- H and 285-F was completed safely and timely using unconventional means to fell the towers due to structural degradation, height, limited access, radiological and asbestos hazards, and a requirement to protect equipment on all sides of the facility as well as preservation of the basins. During felling operations personnel were required to stay outside the fall zone equivalent to a distance of 150% of the height of the towers. Remote operations outside the fall zone required a tracked vehicle to pull cables attached to the columns in a predetermined sequence so as to fell the tower straight down into the basin. Once the towers fell traditional demolition equipment segregated and removed the waste. Wooden cooling towers of this vintage present a difficult challenge to traditional demolition techniques. Because of the height and potential instability of these types of facilities, considerable effort is placed on reducing the potential energy to a point where heavy equipment can reach safely without endangering the operators. The column-pulling technique chosen for both 285-H and 285-F cooling towers proved to be a safe and efficient method for demolition of these types of facilities

2008-01-01

323

Use of treated gasification wastewater in a pilot cooling tower: Final report for the period ending June 30, 1986  

Energy Technology Data Exchange (ETDEWEB)

To date, six cooling tower tests have been conducted to evaluate the wastewater treatment and reuse process utilized by the Great Plains Gasification Plant (GPGP) facility near Beulah, North Dakota. The first three tests, Phases I, II, and III, were performed using extracted, steam-stripped gas liquor (SGL) produced in the UNDERC pilot-scale slagging fixed-bed gasifier as makeup. The last three tests, Phases IV-A, IV-B and V, were conducted using GPGP produced SGL as makeup. The final test, Phase V, is the subject of this report. Prior to its use as Phase V cooling tower makeup, the GPGP SGL was solvent extracted using the Phenosolvan process to reduce the phenolics level, followed by treatment by the Phosam-W process to reduce ammonia concentrations. Additional pretreatment of the Phase V makeup stream included activated sludge treatment to reduce the organic loading, filtering through diatomaceous earth to remove solids, the use of the Calgon Corporation pHreeGUARD dispersant/corrosion inhibitor system to reduce corrosion and fouling, and the use of Calgon H-510 biocide to control microbial populations within the system. All steps in the pretreatment scheme proved to be effective. Corrosion of carbon steel in the system was held to 2 mils per year (mpy) or less, as measured by weight loss coupons. There was no apparent loss of heat transfer capability or increase in pressure drops in the heat transfer equipment. Fouling was minimal in the Phase V system, although at the end of the testing there was a small amount of biomass present on the cooling tower packing as well as some inorganic fouling in the tower basin. The results of this test indicated that a pretreatment program exists that will allow the successful reuse of SGL as cooling tower makeup. 11 refs., 22 figs., 10 tabs.

Mayer, G.G.; Johnson, M.D.; Hetland, M.D.; Wentz, C.A.

1986-09-01

324

Supporting behaviour of natural-draft cooling towers under special consideration of mining influences  

International Nuclear Information System (INIS)

Axially symmetrical cooling shells with their supports and foundation elements exhibit a very favorable supporting behavior with respect to mining influences, resisting them demage-free without or with little additional constructional effort. This paper primarily deals with cooling shells including their supports and foundations. Water supply and distribution, cascading system, and water basin are admittedly unseparable components of wet coolers, but their safety problems with respect to damage due to mining operations lie in the range of classical methods of solution. (orig./TK)

1977-04-01

325

Light water cooled reactors  

International Nuclear Information System (INIS)

Purpose: To flatten the power distribution for the entire reactor by suppressing the power near the center in the direction of the reactor core height, increasing the linear power near the upper end in the direction of the reactor core height and increasing the linear power also near the lower end in the direction of the reactor core height. Constitution: The fuel rods comprise three type of rods, i.e., long fuel rods each having a length over the entire height of the reactor core, short fuel rods forming light water passages at the lower end of the reactor core and short fuel rods forming light water passages at the upper end of the reactor core. Then, the water to fuel volume ratio per unit cross sectional area is made smaller near the center in the direction of the reactor core height, while made greater near the upper and the lower ends in the direction of the reactor core height. (Yoshino, Y.)

1985-06-21

326

Measuring environmental pollution and the effect of cooling towers in the 220 kV substation of the V-1 nuclear power plant at Jaslovske Bohunice  

International Nuclear Information System (INIS)

Two methods are described used to study the level of environmental pollution and the effect of cooling towers on the insulation of the 220 kV substation of the nuclear power plant. The use of the IMICONT apparatus is based on a change in the conductivity of an absorption solution following the passage of air. The change in conductivity is proportional to air pollution. The EGU method is based on measuring the conductivity of fallout trapped in a constant amount of water. The results of measurement show good agreement for the two measuring methods. (J.C.)

1985-01-01

327

Effect of supporting structure stiffness on the drive train assembly of an induced draft cooling tower under seismic effects  

International Nuclear Information System (INIS)

In a nuclear power project an induced draft cooling tower, as a safety-related structure and part of the main cooling system, has to perform satisfactorily under designated seismic effects. While the structural elements can be designed by conventional methods to ensure adequate safety, the seismic qualification of the mechanical components poses a challenge. The paper describes a methodology adopted for the seismic qualification of a typical Drive Train Assembly for the axial flow fan of an induced draft cooling tower, to ensure the structural integrity and functional operability of the assembly during Operating Base Earthquake and Safe Shutdown Earthquake conditions. This is achieved by performing a detailed finite element analysis of the rotating equipment assembly consisting of the electric motor, gear box and fan along with the drive shaft between the motor and the gear box. The various components are modeled using beam elements, plate elements and spring elements to idealize the flexible connections and supports. The floor response spectra derived from a dynamic analysis of the overall structure under stipulated seismic acceleration spectra are the main excitation inputs into the system. The results validate the adequacy of gaps for movement and the strengths of the couplings and bolts to withstand the applied loads. The assumed modeling and analysis methodology are seen to be acceptable procedures for seismic qualification of important components of the cooling tower. (authors)

2005-07-01

328

Cooling tower, construction method method therefor and precast prestressed concrete building units  

International Nuclear Information System (INIS)

A large, thin-shell cooling tower, a method for its erection, and novel precast units are described. Upon a foundation a series of angularly-extending columns is erected, and the columns are joined at their upper ends by a lower ring. Then a ribbed, waffle-like reinforced concrete wall is constructed to extend up from the lower ring and to provide a shell with a shape such as a hyperbolic paraboloid. The ribbed outer (or inner) surface strengthens the structure while enabling the thickness of the portions in between the ribs to be relatively thin. A series of vertically-spaced horizontal circumferential reinforcing bars or post-tensioning cables and a series of horizontally-spaced vertical or inclined bars or cables are included in the wall. The wall is preferably made up from a series of precast units that are of novel structure in themselves. At the top of the wall is an upper ring joining the various elements together

1978-01-01

329

An experimental study on natural draft-dry cooling tower as part of the passive system for the residual decay heat removal  

International Nuclear Information System (INIS)

An experimental apparatus has been built in order to perform sensitivity analysis on the performance of a natural draft-dry cooling tower. This component plays an important role in the passive system for the residual heat decay removal foreseen in the MARS reactor and in the GCFR of the Generation IV reactors. The sensitivity analysis has investigated: 1) the heat exchanger arrangement; two different arrangements have been considered: a horizontal arrangement, in which a system of electrical heaters are placed at the inlet cross section of the tower, and a vertical arrangement, with the heaters distributed vertically around the circumference of the tower. 2) The shape of the cooling tower; by varying the angle of the shell inclination it is possible to obtain a different shape for the tower itself. An upper and a lower angle inclination were modified and by a calculation procedure eleven different configuration were selected. 3) The effect of cross wind on the tower performance. An equation-based procedure to design the dry-cooling tower is presented. In order to evaluate the influence of the shape and the heat exchanger arrangement on the performance of the cooling tower, a geometrical factor (FG) and a thermal factor (FT) are introduced. By analyzing the experimental results, engineering design relations are obtained to model the cooling tower performance. The comparison between the experimental heat transfer coefficient and the heat transfer coefficient obtained by the mathematical procedure shows that there is a good agreement. The obtained results show that it is possible to evaluate the shape and the heat exchanger arrangement to optimize the performance of the cooling tower either in wind-less condition either in presence of cross wind. (authors)

2007-05-13

330

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

331

Study of modes of operation water system movement with bypass system towers cooling by Ecosimpro; Estudio de modos de operacion del sistema de agua de circulacion con sistema de bypass de las torres de refrigeracion mediante Ecosimpro  

Energy Technology Data Exchange (ETDEWEB)

The present paper is based on the thermodynamic study of the system of water circulation of the Central Nuclear de Cofrentes. The objective of the study is the operation of the system through different modes of operation, with the aim of analyze the impact of these modes over the operation of the same. For a complete analysis, it has created a computer model of the system through the EcosimPro software, which is the simulation of the operation modes system and through the results, is the analysis of their feasibility.

Prieto, J.; Molina, M. C.; Gavilan, C.; Molina, J. J.

2013-07-01

332

Replacement of the cooling tower packing at the Goesgen-Daeniken AG nuclear power plant; Ersatz der Kuehlturmeinbauten im Kernkraftwerk Goesgen-Daeniken  

Energy Technology Data Exchange (ETDEWEB)

In 2005 the asbestos cement cooling tower packing was replaced by plastic material. Two years later, the packing showed strong deformations, deposits of solids and weight gain. At the end of 2007 parts of the packing collapsed into the cooling tower basin. Investigations were made, revealing that the thickness of the packing foil was too low and that packing geometry and biofilms on the surface of the packing favoured deposition of solids. Successful measures were taken to solve the problems. (orig.)

Rich, Hans Walter [Kernkraftwerk Goesgen-Daeniken AG, Daeniken (Switzerland)

2012-07-01

333

Explosive Demolition of a Fire-Water Tower At East Tennessee Technology Park, Oak Ridge TN  

International Nuclear Information System (INIS)

On June 17, 2006, the Department of Energy (DOE) successfully demolished a ?60 year old fire-water tower (K-1206-E), located at the East Tennessee Technology Park (ETTP) in Oak Ridge, TN, using strategically placed explosive charges. The subject demolition project was executed by MCM Management Corporation and Demolition Dynamics under the management of DoE's prime contractor Bechtel Jacobs Company LLC (BJC). The K-1206-E Fire Water Tower (Tower) supported the ETTP fire water protection system from the mid- 1950's until 1991. The 378,500-L (100,000-gallon) Tower, elevated 53-m (175-feet) above grade, was located in a grassy area within 152-m (500-feet) of several other occupied facilities. Electrical, control circuits and supply water servicing the Tower were deactivated in 2003. Free liquids and sludge were removed from the tank prior to demolition. Demolition of a facility employing explosive demolition at a federal site in the 'post-9/11 era' was a substantial challenge. The subject paper discusses: - the planning and coordination steps that were taken to successfully overcome the challenges prior to the demolition of the empty, deactivated Tower; - the method used for the engineered demolition of the Tower; and - the factors responsible for the successful execution of this demolition project. At least two previous attempts were made to demolish the Tower. In the first attempt, the execution of the project was deferred by the re-allocation of funds. In the subsequent attempt in 2004, the execution of this project was postponed due to concerns that an adjacent facility would have to shut down operations during the duration of mobilization and execution of the project and thereby incur potential financial losses. A total of 51 cubic meters (1,800 cubic feet) of demolition debris was generated, which was compliantly disposed of at a local landfill followed by site restoration

2008-01-01

334

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

335

Ecological aspect of cooling water treatment  

Energy Technology Data Exchange (ETDEWEB)

In general, cooling water taken as natural water from a surface water body will have to be treated. Mechanical purification will suffice in flow-through or open-loop cooling; however, closed-loop cooling will require additional measures. In addition, corrosion and deposit formation will have to be prevented in continuous operation. In principle, many problems in cooling water system operation can be combatted by appropriate chemicals. These agents are required to be effective at their site of application but not in the surface water into which the cooling water is discharged as effluent. (orig./PW).

Wunderlich, M.

1985-09-01

336

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

337

Apparatus for pouring emergency cooling water  

International Nuclear Information System (INIS)

Object: To reliably cool a fuel rod by providing a cooling water guide tube within a channel box in a boiling water type reactor. Structure: A cooling water guide tube is accommodated parallel to fuel rods within a channel box in a boiling water type reactor. The cooling water guide tube is provided at the upper end with a funnel-like opening section and has a side wall formed with holes. When the level of the coolant within the reactor is lowered, cooling water is sprayed from a spray means onto the fuel assembly, and it is partly led to flow from the funnel-like opening to the cooling water guide tube and thence is sprayed from the holes into the channel box to cool the fuel rods. (Moriyama, K.)

1975-01-01

338

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

339

Corrosion of reinforced concrete in nuclear plants: application of Bayesian networks to the risk management of cooling towers  

International Nuclear Information System (INIS)

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 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)

2006-10-10

340

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

 
 
 
 
341

Forward osmosis applied to evaporative cooling make-up water  

Energy Technology Data Exchange (ETDEWEB)

Modern Water is in the process of developing a number of forward osmosis based technologies, ranging from desalination to power generation. This paper outlines the progress made to date on the development and commercial deployment of a forward osmosis based process for the production of evaporative cooling tower make-up water from impaired water sources, including seawater. Evaporative cooling requires significant amounts of good quality water to replace the water lost by evaporation, drift and blowdown. This water can be provided by conventional desalination processes or by the use of tertiary treated sewage effluent. The conventional processes are well documented and understood in terms of operation and power consumption. A new process has been successfully developed and demonstrated that provides make-up water directly, using a core platform 'forward osmosis' technology. This new technology shows significant promise in allowing various raw water sources, such as seawater, to be used directly in the forward osmosis step, thus releasing the use of scarce and valuable high grade water for other more important uses. The paper presents theoretical and operational results for the process, where it is shown that the process can produce make-up water at a fraction of the operational expenditure when compared to conventional processes, in particular regarding power consumption, which in some cases may be as low as 15 % compared to competing processes. Chemical additives to the cooling water (osmotic agent) are retained within the process, thus reducing their overall consumption. Furthermore the chemistry of the cooling water does not support the growth of Legionella pneumophila. Corrosion results are also reported. (orig.)

Nicoll, Peter; Thompson, Neil; Gray, Victoria [Modern Water plc, Guildford (United Kingdom)

2012-11-15

342

European supercritical water cooled reactor  

International Nuclear Information System (INIS)

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.

2011-09-01

343

The cooling water from Ringhals  

International Nuclear Information System (INIS)

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 m"3/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 km"2. Usually, however, the plume covered about 2.5 km"2 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

344

Nonlinear analysis of safety, damage and lifespan of wind-loaded natural draft cooling towers. Nichtlineare Analyseverfahren fuer Tragsicherheit, Schaedigungsevolution und Restlebensdauer windbeanspruchter Naturzugkuehltuerme  

Energy Technology Data Exchange (ETDEWEB)

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.).

Basar, Y.; Gruber, K.; Kraetzig, W.B.; Meskouris, K.; Zahlten, W. (Inst. fuer Statik und Dynamik, Bochum Univ. (Germany))

1992-11-01

345

Updating of a finite element model of the Cruas 2 cooling tower; Recalage d`un modele dynamique du refrigerant no.2 de Cruas  

Energy Technology Data Exchange (ETDEWEB)

A method based on modal analysis and inversion of a dynamic FEM model is used to detect changes in the dynamic behavior of nuclear plant cooling towers. Prior to detection, it is necessary to build a representative model of the structure. In this paper are given details about the CRUAS N. 2 cooling tower modelling and the updating procedure used to match the model to on-site measurements. First, were reviewed previous numerical and experimental studies on cooling towers vibrations. We found that the first eigenfrequencies of cooling towers are very sensitive to boundary conditions at the top and the bottom of the structure. Then, we built a beam and plate FEM model of the CRUAS N. 2 cooling tower. The first calculated modes were located in the proper frequency band (0.9 Hz - 1.30 Hz) but not distributed according to the experimental order. We decided to update the numerical model with MADMACS, an updating model software. It was necessary to: - decrease the shell stiffness by 30%; - increase the top ring stiffness by 300%; - modify the boundary conditions at the bottom by taking into account the soil impedance. In order to obtain a difference between the measured and the corresponding calculated frequencies less than 1%. The model was then judged to be realistic enough. (author). 23 figs., 13 refs., 1 annex.

Billet, L.

1994-03-01

346

Efficient Water Management in Water Cooled Reactors  

International Nuclear Information System (INIS)

One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world'. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. Water scarcity is becoming one of the most pressing crises affecting the planet. A reliable supply of water and energy is an important prerequisite for sustainable development. A large number of nuclear power reactors are being planned in many developing countries to address these countries' increasing energy demands and their limited fossil resources. New construction is expected in the USA, Europe and Asia, as well. Reducing water use and consumption by nuclear power plants is likely to help developing countries in introducing nuclear power into their energy supply mix. A large number of the countries that have recently begun to consider the introduction of nuclear power are in water scarce regions, which would certainly limit the possibility for deployment of nuclear power plants, in turn hindering these countries' development and energy security. Thus, there is a large incentive to enhance efforts to introduce innovative water use, water management practices and related technologies. Water management for nuclear power plants is gaining interest in IAEA Member States as an issue of vital importance for the deployment of nuclear power. Recent experience has shown that some nuclear power plants are susceptible to prolonged drought conditions, forcing reactors to be shut down or power to be reduced to a minimal level. In some cases, environmental issues have resulted in regulations that limit the possibility for water withdrawal as well as water discharge. Regarding the most common design for cooling nuclear power plants, this has led to a complicated siting procedure for new plants and expensive retrofits for existing ones. The IAEA has already provided its Member States with reports and documents that address the issue. At the height of nuclear power expansion in the 1970s, the need for guidance in the area resulted in publications such as Thermal Discharges at Nuclear Power Stations - Their Management and Environmental Impact (Technical Reports Series No. 155) and Environmental Effects of Cooling Systems (Technical Reports Series No. 202). Today, amid the so-called nuclear renaissance, it is of vital importance to offer guidance to the Member States on the issues and possibilities that nuclear power water management brings. Management of water at nuclear power plants is an important subject during all phases of the construction, operation and maintenance of any nuclear power plant. Water management addresses the issue of securing water for condenser cooling during operation, for construction (during the flushing phase), and for inventory control, including make-up to the primary coolant system and discharge from the radioactive liquid w

2012-08-01

347

Development and verification of laboratory model techniques for prediction of near-field behavior of cooling-tower plumes. Final report  

Energy Technology Data Exchange (ETDEWEB)

The primary purpose of this study was to validate, by comparing corresponding model and prototype data, small-scale model testing of mechanical draft cooling towers as a reliable means of plume prediction. Tests were also conducted to investigate the effects of plume buoyancy and ambient (wind) velocity, and plant-building location on plume trajectories, tower recirculation, plume downwash, and plume merger. Modeling requirements and limitations are summarized. Small-scale models of two existing plants for which sufficient field data were available to permit meaningful comparison were tested in the Environmental Flow Facility (EFF) of the Iowa Institute of Hydraulic Research. The EFF is a recirculatig water flume with a working section 19.8-m long, 3-m wide, and 2.3-m deep. Laboratory testing techniques were developed and modified as needed to bring field and laboratory data into conformity. Particular attention was directed to the role of the velocity distribution in the boundary layer of approach flow; vortex generators and floor roughness were installed in the upstream section of the flume to produce a velocity distribution corresponding to the 1/6 power law. The boundaries of prototype visible plumes were delineated from laboratory data on the stack-effluent concentration distributions. The boundaries of the visible plumes obtained from the scale models were in satisfactory agreement with those obtained in the prototype.

Jain, S.C.; Kennedy, J.F.

1980-03-01

348

Steam-Electric Power-Plant-Cooling Handbook  

Energy Technology Data Exchange (ETDEWEB)

The Steam-Electric Power Plant Cooling Handbook provides summary data on steam-electric power plant capacity, generation and number of plants for each cooling means, by Electric Regions, Water Resource Regions and National Electric Reliability Council Areas. Water consumption by once-through cooling, cooling ponds and wet evaporative towers is discussed and a methodology for computation of water consumption is provided for a typical steam-electric plant which uses a wet evaporative tower or cooling pond for cooling.

Sonnichsen, J.C.; Carlson, H.A.; Charles, P.D.; Jacobson, L.D.; Tadlock, L.A.

1982-02-01

349

Execution of structural rehabilitation measures at a cellular wet cooling tower with suction fans in Arzberg power plant of Energieversorgung Oberfranken AG  

Energy Technology Data Exchange (ETDEWEB)

Within the framework of a retrofit of a flue gas cleaning plant, economic considerations led to the decision to repair the badly damaged reinforced concrete components of an old cellular wet cooling tower, more than 20 years old, in order to utilize it for a further 15 years. The repair measures, which were carried out using special materials, were undertaken following intensive pre-planning with a high level of technical input in two constructional phases with considerable success. These measures rendered the construction of a new cooling tower unnecessary. 13 refs., 9 figs., 2 tabs.

Ide, G.; Gieler, R.P.; Stroever, H. (Energieversorgung Oberfranken AG, Arzberg (Germany))

1992-01-01

350

Development of a new method of measurement of the polarization resistance to estimate the level of corrosion of the reinforced concrete of cooling towers  

International Nuclear Information System (INIS)

This paper summarises the results obtained from the numerical simulations of an operative measurement mode of polarization resistance adapted for evaluating the corrosion of reinforced concrete on cooling towers. A simple operative measurement mode of Rp is proposed, adapted for cooling towers submitted to corrosion due to carbonation. By means of numerical experimentations, abacuses and correction laws are built involving the different influencing parameters: steel reinforcement's concrete cover, concrete resistivity and current intensity injected from the counter electrode. Finally, a first application of the proposed procedure for calculating the real value of Rp in laboratory conditions is presented. (authors)

2014-03-19

351

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

2009-01-01

352

Quantifying the Water Tower of the Third Pole: State of the Art and Research Challenges  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mountains are the water towers of the world, particularly in Asia, where rivers all are fed from the Tibetan plateau and adjacent mountain ranges. In this area, referred to as the Third Pole, snow and glacial melt are important hydrologic processes, such that climate change is expected to seriously affect melt characteristics and related runoff. The Third Pole provides water resources to nearly two billion people in Asia. However, uncertainty about key hydrological processes at hi...

Immerzeel, W. W.; Bierkens, M. F. P.

2011-01-01

353

Chromium levels in fish from a lake chronically contaminated with chromates from cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Chromium concentrations of several fish species (bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides) goldfish (Carassius auratus), and mosquitofish (Gambusia affinis)) from White Oak Lake (WOL), a small impoundment which formerly received cooling water blowdown containing high Cr(VI) concentrations, were measured to determine levels of tissue accumulation. Chromium concentrations in the muscle and/or whole body (excluding G.I. tract) of some species in some years were found to be negatively correlated with total fish weight. Results suggest that Cr levels in muscle and whole body of most species analyzed from WOL and from Melton Hill Reservoir, an uncontaminated impoundment, may be inversely related to fish weight. Muscle and wholebody Cr concentrations were not significantly different from each other in bluegill or largemouth bass. With the exception of goldfish collected in 1969, between species comparisons of chromium levels in WOL fish within years showed no statistically significant differences, indicating that there was not trophic level effect on Cr accumulation in tissues of the species examined. There was also no significant difference in Cr concentration in muscle of bluegill and largemouth bass from WOL and Melton Hill Reservoir, indicating that these species either effectively regulate their Cr absorption or that the elevated Cr levels in WOL were in a form that is unavailable for absorption into tissues.

Elwood, J.W.; Beauchamp, J.J.; Allen, C.P.

1980-01-01

354

Chromium levels in fish from a lake chronically contaminated with chromates from cooling towers  

Energy Technology Data Exchange (ETDEWEB)

Chromium concentrations of several fish species (bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides) goldfish (Carassius auratus), and mosquitofish (Gambusia affinis)) from White Oak Lake (WOL), a small impoundment which formerly received cooling water blowdown containing high Cr(VI) concentrations, were measured to determine levels of tissue accumulation. Chromium concentrations in the muscle and/or whole body (excluding G.I. tract) of some species in some years were found to be negatively correlated with total fish weight. Results suggest that Cr levels in muscle and whole body of most species analyzed from WOL and from Melton Hill Reservoir, an uncontaminated impoundment, may be inversely related to fish weight. Muscle and wholebody Cr concentrations were not significantly different from each other in bluegill or largemouth bass. With the exception of goldfish collected in 1969, between species comparisons of chromium levles in WOL fish within years showed no statistically significant differences, indicating that there was not trophic level effect on Cr accumulation in tissues of the species examined.There was also no significant difference in Cr concentration in muscle of bluegill and largemouth bass from WOL and Melton Hill Reservoir, indicating that these species either effectively regulate their Cr absorption or that the elevated Cr levels in WOL were in a form that is unavailable for absorption into tissues.

Elwood, J.W.; Beauchamp, J.J.; Allen, C.P.

1980-01-01

355

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

356

A cooling water system as a biofilm reactor for the treatment of municipal water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, a water cooling tower was used as a low-rate biofilm reactor for treating municipal wastewater. The performance of the system was evaluated at three different flow rates. The biofilm reactor gave the best results at a flow rate of 1.6l/s, namely 43.3% nitrogen removal, 42.3% chemical oxygen demand (COD) removal, 1.7% phosphorus removal and 39.8% suspended solids (SS) removal. These results were achieved with a once-through flow and low organic and hydraulic loads. This type of ...

Cloete, T. E.; Smith, Z.; Saayman, G.

1999-01-01

357

Injected Water Augments Cooling In Turboshaft Engine  

Science.gov (United States)

Report describes experiments in which water injected into compressor-bleed cooling air of aircraft turboshaft engine. Injection of water previously suggested as way to provide additional cooling needed to sustain operation at power levels higher than usual. Involves turbine-inlet temperatures high enough to shorten lives of first-stage high-pressure turbine blades. Latent heat of vaporization of injected water serves as additional heat sink to maintain blades at design operating temperatures during high-power operation.

Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

1989-01-01

358

Meteorological effects of the cooling towers at the Oak Ridge Gaseous Diffusion Plant. II. Predictions of fog occurrence and drift deposition  

International Nuclear Information System (INIS)

The frequency of occurrence of fogs and the rate of deposition of chromate due to emissions from the cooling towers at the Oak Ridge Gaseous Diffusion Plant are calculated. Observations of drift deposition agree fairly well with calculated values. A detailed summary of significant findings is given

1975-09-01

359

The Water Quality Deterioration Element Test for the Secondary Cooling System under a Full Power Operation of 30 MWth in HANARO  

International Nuclear Information System (INIS)

HANARO, a multi-purpose research reactor, a 30 MWth open-tank-in-pool type, has been under a full power operation since last year. The heat generated by the core of HANARO is transferred to the primary cooling water. And the cooling water transfers the heat to the secondary cooling water through the primary cooling heat exchanger. The heat absorbed by the secondary cooling water is removed through a cooling tower. The quality of the secondary cooling water is deteriorated by a temperature variation of the cooling water and a foreign material flowing over the cooling water through the cooling tower fan for a cooling. From these, a corrosion reduces the life time of a system, the scale degrades the heat transfer effect and the sludge and slime induces a local corrosion. For reducing these impacts, the quality of the secondary cooling water is treated by a high ca-hardness water quality program by maintaining a super saturated condition of ions, 12 of a ca-hardness concentration. A test has been performed under an operation of 24 MWth power and a mode of a four day operation and three day maintenance. This paper describes the water quality deterioration element test for the secondary cooling system under a full power operation of 30 MWth and a mode of a twenty three day operation and twelve day maintenance

2006-05-25

360

"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

 
 
 
 
361

A direct, evaporatively cooled, three-ton lithium bromide-water absorption chiller for solar application  

Energy Technology Data Exchange (ETDEWEB)

Lithium bromide absorption machines first appeared commercially circa 1940. In all designs marketed, absorber/condenser heat has been rejected from the cycle through shell-and-tube exchangers to circulating water that is then processed in contact with the ambient air through a cooling tower. In mechanical refrigeration technology, evaporative condensing products have been an available alternative to water-cooled condensers with separate cooling towers. Lithium bromide machines have not been available with this alternative, mainly because of the difficulty of managing internal and external heat transfer processes through a common surface configuration that would meet all the needs satisfactorily. The main focus of this paper is the development of a direct, evaporatively cooled absorber/condenser. Other features of the chiller already displayed in the past or presently available hardware on the market will not be a part of this discussion. A second objective is to establish the significance of evaporative cooling for active solar-cooling devices and, in particular, as an alternative to dry-air cooling as the means of heat rejection for solarcooling equipment.

Merrick, R.H.

1982-01-01

362

Water injection device of cooling water and nuclear reactor  

International Nuclear Information System (INIS)

A jet pump is disposed to a water injection flow channel below a pressure accumulation vessel incorporating cooling water and pressurized gases. A driving water nozzle in the jet pump is connected to a driving water flow channel having an opening below the liquid surface of cooling water in the pressure accumulation vessel. A sucking channel in communication with the diffuser guide portion of the jet pump is disposed to the bottom of the pressure accumulation vessel. Upon reactor accident, cooling water in the driving water channel is jetted from the driving water nozzle to a throat of the diffuser of the jet pump. With such a procedure, cooling water in the sucking flow channel is sucked into the throat of the diffuser and mixed with the cooling water from the driving water nozzle. As a result, a great amount of cooling water flows to the water injection channel and is injected into a reactor pressure vessel. If the water level in the pressure accumulation vessel is reduced lower than the opening of the driving water flow channel, the operation of the jet pump is stopped. The flow rate of the water injection is changed to small amount only from the sucking flow channel by the stoppage of the jet pump. (I.N.)

1993-05-25

363

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

364

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

365

Evaporative cooling: water for thermal comfort  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 climat...

José Rui Camargo

2008-01-01

366

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

International Nuclear Information System (INIS)

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

367

Cooling water for SSC experiments: Supplemental Conceptual Design Report (SCDR)  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the following topics on cooling water design on the superconducting super collider; low conductivity water; industrial cooling water; chilled water systems; and radioactive water systems. (LSP)

Doyle, R.E.

1989-10-20

368

Small capacity water/lithium bromide absorption chiller for solar cooling applications  

Energy Technology Data Exchange (ETDEWEB)

Using solar thermal collectors to provide hot water or heating is a well established technology. To reach a higher solar fraction in heating bigger collectors areas are needed. These relatively big collector areas generate excess heat in summer which cannot be used for heating at that time. Storage for the winter time is possible but costly. Solar thermal powered absorption cooling offers a good possibility to use these excess heat to provide cooling during the summer and to increase the efficiency of the whole system. Solar cooling is also a promising opportunity to cut electrical peak loads during the summer and to reduce fossil fuel consumption. One of the constraints for a wider use of this technology in recent years was the unavailability of a suitable absorption chiller in the capacity range below 50 kW which is interesting for many applications. A water/lithium bromide absorption chiller with a nominal capacity of 15 kW was developed. A special heat exchanger design is used to reach small differences between external and internal temperatures. The chiller can be driven by hot water generated by solar thermal collectors or other heat sources. It was designed for low driving temperatures to allow the solar thermal collectors to work with a good efficiency. Design conditions are 90 C hot water input, 32 C cooling water input, 15 C cold water output. At these conditions the chiller reaches a COP of 0,7. Three test installations with various configurations and at different locations have been installed. Different collector types (flat plate and vacuum tube) and cooling towers (wet and dry) have been tested. To predict the performance of the whole solar cooling system with different peripheral equipment TRNSYS simulations were done. The effects of using different collectors, storages, cooling towers and cooling coils were evaluated. Measurement and simulation results for some applications at different locations are presented. (orig.)

Safarik, M.; Richter, L. [Institute of Air-conditioning and Refrigeration gGmbH, Dresden (Germany); Heinrich, C. [University of Applied Sciences Zittau/Goerlitz (Germany); Otto, M. [EAW Energieanlagenbau GmbH, Westenfeld (Germany)

2004-07-01

369

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

370

Water treatment for the drycooling tower for the 300 MW THTR  

International Nuclear Information System (INIS)

For the condensation of the turbine waste steam in water-filled surface condensers by indirect air cooling, 32 000 m3 colling water per hour are circulated in a closed system. The paper describes the conditioning and preparation of cooling water in consideration of the materials for the condenser tubing. The tests with copper materials were one of the decisive factors for the made material selection. (orig.)

1979-05-23

371

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

372

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

373

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

Science.gov (United States)

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.

Lebedev, S. V.; Ciardi, A.; Ampleford, D.; Bland, S. N.; Bott, S. C.; Chittenden, J. P.; Hall, G.; Rapley, J.; Frank, A.; Blackman, E. G.

2006-04-01

374

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 24şC.

José Rui Camargo

2008-08-01

375

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

376

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

Energy Technology Data Exchange (ETDEWEB)

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&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.

Gary Vine

2010-12-01

377

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 rec...

2013-01-01

378

The atmospheric cooling of nuclear power stations  

International Nuclear Information System (INIS)

Four different types of nuclear reactor are considered: light water reactors, high temperature reactors with steam circulation and with direct gas turbine circulation, and fast breeder reactors. Wet and dry cooling towers are described and experimental studies carried out using cooling tower models are presented. (G.T.H.)

1978-01-01

379

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

380

Materials for advanced water cooled reactors  

International Nuclear Information System (INIS)

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

1991-05-14

 
 
 
 
381

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

382

Investigations of effects of thermal discharges in Rhine river waters. Part of a coordinated programme on the physical and biological effects of cooling systems and thermal discharges at nuclear power plants  

International Nuclear Information System (INIS)

The report envisages two aspects of cooling systems: heat exchange between water and atmosphere; cooling tower plume modelling. The author gives the estimated ''cooling capacity'' of German rivers and estuaries and describes a station at Rheinhausen, measuring directly the heat exchange between the river Rhine and the atmosphere. The influence of meteorological and topographical parameters is discussed and the total incertainty in extrapolating formular is assessed. A number of field studies have been carried out to measure plume behaviour of cooling towers and to provide the data basis for comparison of existing models. The average plume rise is well predicted. The experimental programme carried out in Germany since 1973 is described. The one dimensional models TOWER and SAUNA.S are in agreement with experimental results except for short plumes. The last plume model WALKURE shows considerable improvement. It is specially suited for the calculations of the cooling tower plume behaviour under influence of temperature and humidity stratifications in the ambient atmosphere

1978-01-01

383

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

1990-09-01

384

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

385

Evaporative cooling of speleothem drip water  

Science.gov (United States)

This study describes the first use of concurrent high-precision temperature and drip rate monitoring to explore what controls the temperature of speleothem forming drip water. Two contrasting sites, one with fast transient and one with slow constant dripping, in a temperate semi-arid location (Wellington, NSW, Australia), exhibit drip water temperatures which deviate significantly from the cave air temperature. We confirm the hypothesis that evaporative cooling is the dominant, but so far unattributed, control causing significant disequilibrium between drip water and host rock/air temperatures. The amount of cooling is dependent on the drip rate, relative humidity and ventilation. Our results have implications for the interpretation of temperature-sensitive, speleothem climate proxies such as ?18O, cave microecology and the use of heat as a tracer in karst. Understanding the processes controlling the temperature of speleothem-forming cave drip waters is vital for assessing the reliability of such deposits as archives of climate change.

Cuthbert, M. O.; Rau, G. C.; Andersen, M. S.; Roshan, H.; Rutlidge, H.; Marjo, C. E.; Markowska, M.; Jex, C. N.; Graham, P. W.; Mariethoz, G.; Acworth, R. I.; Baker, A.

2014-01-01

386

Evaporative cooling of speleothem drip water.  

Science.gov (United States)

This study describes the first use of concurrent high-precision temperature and drip rate monitoring to explore what controls the temperature of speleothem forming drip water. Two contrasting sites, one with fast transient and one with slow constant dripping, in a temperate semi-arid location (Wellington, NSW, Australia), exhibit drip water temperatures which deviate significantly from the cave air temperature. We confirm the hypothesis that evaporative cooling is the dominant, but so far unattributed, control causing significant disequilibrium between drip water and host rock/air temperatures. The amount of cooling is dependent on the drip rate, relative humidity and ventilation. Our results have implications for the interpretation of temperature-sensitive, speleothem climate proxies such as ?(18)O, cave microecology and the use of heat as a tracer in karst. Understanding the processes controlling the temperature of speleothem-forming cave drip waters is vital for assessing the reliability of such deposits as archives of climate change. PMID:24895139

Cuthbert, M O; Rau, G C; Andersen, M S; Roshan, H; Rutlidge, H; Marjo, C E; Markowska, M; Jex, C N; Graham, P W; Mariethoz, G; Acworth, R I; Baker, A

2014-01-01

387

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 ĂÂdrink when you are thirstyĂÂ 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: ĂÂMust I drink 64 ounces of water each day?ĂÂ (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, weĂÂll 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

388

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

389

Re-routing of cooling water pipeline  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis was made for Wärtsilä Finland Oy department of Power Plants. The purpose of this thesis was to compare different solutions and to find the best and cost-efficient solution for cooling water pipelines when radiators were located on the roof of the power plant.

Kuusisto, Tuomas

2011-01-01