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1

Evaporative cooling of water in a natural draft cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model of the performance of a cooling tower is presented. The model consists of two interdependent boundary-value problems, a total of 9 ODE, and the algorithm of self-consistent solution. The first boundary-value problem describes evaporative cooling of water drops in the spray zone of a cooling tower; the second boundary-value problem describes film cooling in the pack. Simulation of the boundary-value problems has been made. The comparison between experimental data and calculated results showed that the model correctly describes the basic regularities of the cooling tower performance. In the effective droplet-radius approximation the difference in the thermal efficiency between calculated and experimental results does not exceed 3%. The limits of applicability of the developed mathematical model and its possibilities are discussed.(author)

Fisenko, S.P.; Petruchik, A.I.; Solodukhin, A.D. [National Academy of Sciences of Belarus (Belarus). A.V. Luikov Heat and Mass Transfer Inst.

2002-11-01

2

Use of nanofiltration to reduce cooling tower water consumption.  

Energy Technology Data Exchange (ETDEWEB)

Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

Altman, Susan Jeanne; Ciferno, Jared

2010-10-01

3

Use of nanofiltration to reduce cooling tower water usage.  

Energy Technology Data Exchange (ETDEWEB)

Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

Sanchez, Andres L.; Everett, Randy L.; Jensen, Richard Pearson; Cappelle, Malynda A.; Altman, Susan Jeanne

2010-09-01

4

Cooling tower calculations  

International Nuclear Information System (INIS)

The problems are summed up of the dynamic calculation of cooling towers with forced and natural air draft. The quantities and relations are given characterizing the simultaneous exchange of momentum, heat and mass in evaporative water cooling by atmospheric air in the packings of cooling towers. The method of solution is clarified in the calculation of evaporation criteria and thermal characteristics of countercurrent and cross current cooling systems. The procedure is demonstrated of the calculation of cooling towers, and correction curves and the effect assessed of the operating mode at constant air number or constant outlet air volume flow on their course in ventilator cooling towers. In cooling towers with the natural air draft the flow unevenness is assessed of water and air relative to its effect on the resulting cooling efficiency of the towers. The calculation is demonstrated of thermal and resistance response curves and cooling curves of hydraulically unevenly loaded towers owing to the water flow rate parameter graded radially by 20% along the cross-section of the packing. Flow rate unevenness of air due to wind impact on the outlet air flow from the tower significantly affects the temperatures of cooled water in natural air draft cooling towers of a design with lower demands on aerodynamics, as early as at wind velocity of 2 m.s-1 as was demonstrated on a concrete example. (author). 11 figs., 10 refs

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

6

Calculating the evaporated water flow in a wet cooling tower  

International Nuclear Information System (INIS)

On a cooling tower, it is necessary to determine the evaporated water flow in order to estimate the water consumption with a good accuracy according to the atmospheric conditions, and in order to know the characteristics of the plume. The evaporated flow is small compared to the circulating flow. A direct measurement is very inaccurate and cannot be used. Only calculation can give a satisfactory valuation. The two usable theories are the Merkel's one in which there are some simplifying assumptions, and the Poppe's one which is more exact. Both theories are used in the numerical code TEFERI which has been developed and is run by Electricite de France. The results obtained by each method are compared and validated by measurements made in the hot air of a cooling tower. The consequences of each hypothesis of Merkel's theory are discussed. This theory does not give the liquid water content in the plume and it under-estimates the evaporated flow all the lower the ambient temperature is. On the other hand, the Poppe's method agrees very closely with the measurements as well for the evaporated flow than for the liquid water concentration. This method is used to establish the specific consumption curves of the great nuclear plants cooling towers as well as to calculate the emission of liquid water drops in the plumes. (author). 11 refs., 9 figs

7

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

8

Design change of tower cooling water system for proton accelerator research center  

International Nuclear Information System (INIS)

The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted

9

Design change of tower cooling water system for proton accelerator research center  

Energy Technology Data Exchange (ETDEWEB)

The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted.

Jeon, G. P.; Kim, J. Y.; Song, I. T.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Han, Y. G. [KAERI, Daejeon (Korea, Republic of)

2012-10-15

10

Improve crossflow cooling tower operation  

International Nuclear Information System (INIS)

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

11

The efficiency index of mechanical-draft and chimney-type water cooling towers operation  

Science.gov (United States)

It is shown that the water temperature ranges in cooling towers given in the regulatory documents are not consistent with the standardized heat loads. It is also demonstrated that the existing criteria for estimating the effect from retrofitting of cooling towers are far from being perfect. The notions of cooling tower efficiency index and their operating characteristics with the nominal values of the main parameters are introduced. A procedure for determining these quantities is developed. An algorithm for directly calculating the economic effect from reconstruction of cooling towers is proposed.

Sosnovskii, S. K.; Kravchenko, V. P.

2014-09-01

12

Ecological impact of chloro-organics produced by chlorination of cooling tower waters  

International Nuclear Information System (INIS)

Experimental results of the initial assessment of chlorine-containing compounds in the blowdown from cooling towers and the possible mutagenic activity of these compounds are reported. High-resolution liquid chromatographic separations were made on concentrates of the blowdown from the cooling tower at the High Flux Isotope Reactor (HFIR) and from the recirculating water system for the cooling towers at the Oak Ridge Gaseous Diffusion Plant (ORGDP), Oak Ridge, Tennessee. The chromatograms of chlorinated cooling waters contained numerous uv-absorbing and cerate-oxidizable constituents that are now being processed through a multicomponent identification procedure. Concentrates of the chlorinated waters are also being examined for mutagenic activity

13

Utility avoids cooling tower  

International Nuclear Information System (INIS)

After more than four years of often rancorous debate, New Jersey late last month approved a plan that permits the state's largest utility to reclaim and restore Delaware Bay marshland instead of constructing a costly cooling tower for two nuclear power units. Environmental interests say they'll appeal the wetlands proposal, calling it an open-quotes unproven experimentclose quotes that violates Clean Water Act provisions

14

Thermal aerodynamical protection of water cooling towers from moistening and freezing  

International Nuclear Information System (INIS)

Results of analytical and experimental investigations of thermal and mass exchange at water cooling towers permitting to recommendate a thermal aerodynamical protection as installation of concentric shield inside of tower to exclude moistening and freezing of reinforced concrete cases and sheathings are presented

15

Investigations into the treatment of lime-decarbonized cooling tower make-up water for use as secondary cooling water  

International Nuclear Information System (INIS)

At Gundremmingen nuclear power station treated water from the Danube is used, prior to its use as cooling tower make-up water, for the cooling of conventional cooling points (secondary cooling water). The treatment is effected by means of decarbonization with lime, subsequently it is dosed with a hardness stabilizing agent. In these secondary cooling water systems this pipework is manufactured from plain uncoated steel and the heat exchanger tubes predominantly from special brass 71 and ultra-pure copper. Problems occured during commissioning. They were the cause of installing on site a test cooling plant with simulation of the real conditions in respect of materials, flow velocity and temperature with the object treatment of secondary cooling water. (orig.)

16

Water tower  

CERN Multimedia

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

1970-01-01

17

Cooling tower make-up water processing in the nuclear power plant Muelheim-Kaerlich  

International Nuclear Information System (INIS)

The cooling tower make-up water processing mainly fulfils the task of supplying the power plant with the required quality of water. The construction and functioning of the of the cooling tower make-up water processing system are described, as well as the water-chemical method of sludge separation and demineralization. The new kind of slurry draining plant is designed so as to be able to completely process the thin slurry produced when operating seven presses during thickening upto a crude water pollution value of 200 g TS/m3 in 24-hour operation. (GL)

18

Evaluation Of Cooling Tower Degradation  

International Nuclear Information System (INIS)

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

19

Effects of cooling towers  

International Nuclear Information System (INIS)

A description of function, operational performance, emissions and effects, the emphasis being on showing the present state of knowledge on the diffusion and effects of plumes from cooling towers. Meteorological and chemical as well as microbiological aspects are dealt with. The state of knowledge of the superposition of several cooling tower plumes in a single location, noise pollution as well as aesthetic aspects are discussed. The commission is still arguing that meteorological location expertises are no more necessary for such cooling towers where the effects are concerned. (DG)

20

Experience with a plant for the treatment of cooling tower make-up water  

International Nuclear Information System (INIS)

Cooling tower make-up water treatment is based on the coprecipitation of the river water impurities and iron hydroxide in a continuous flow process. Clean water and watery slurry are separated on parallel-plate separators and subsequently then treated further. The parallel separators permit a compact form of construction of the whole plant and thereby open up possibilities for, inter alia, weather protection for uninterrupted winter operation. In summary, cooling tower make-up water treatment has in its first full year of operation satisfactorily fulfilled the requirement of reliable service water supply at all times. However, the operation of the plant was too costly in maintenance; this was the reason for a multiplicity of optimization measures. (orig.)

 
 
 
 
21

Numerical study of coupled transfer of heat and mass between air and water inside a geothermal water cooling tower  

Science.gov (United States)

In the south of Tunisia, geothermal water is used to irrigate cultures. Since its temperature is very high (70 C), geothermal water is cooled by cooling towers. These towers are sized empirically and present many operating problems such as excessive energy consumption, big loss of vapour and low cooling efficiency. The aim of our work is modelling the coupled heat and mass transfer between air and water inside the cooling tower. The most important results obtained are that the evaporative potential is dominating the convective one in the cooling process. That's why the cooling is more efficient in summer than in hibernal period when humidity of ambient air reaches high values. In other hand, the negative convective phenomenon is illustrated. In fact, at the bottom of the tower, water temperature reaches the air one; the two fluids begin to cooling simultaneously. Air is cooled by convection and water by evaporation. We demonstrate also that there is no point in putting fans in working during cold weather. We studied also the effect of the variation of heat transfer coefficient on the efficiency of cooling.

Bassem, Mohamed Mehdi; Bourouni, Karim; Thameur Chaibi, Mohamed

2006-11-01

22

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

23

Genome Sequence of Legionella massiliensis, Isolated from a Cooling Tower Water Sample.  

Science.gov (United States)

We present the draft genome sequence of Legionella massiliensis strain LegA(T), recovered from a cooling tower water sample, using an amoebal coculture procedure. The strain described here is composed of 4,387,007 bp, with a G+C content of 41.19%, and its genome has 3,767 protein-coding genes and 60 predicted RNA genes. PMID:25323728

Pagnier, Isabelle; Croce, Olivier; Robert, Catherine; Raoult, Didier; La Scola, Bernard

2014-01-01

24

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

25

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

26

Calculation of counter-current cooling towers at high water inlet temperature  

International Nuclear Information System (INIS)

It has been long known that the Merkel number (Me = sigma x F/msub(w)) for a given cooling tower does not exhibit a constant at varying water inlet temperatures; it decreases with increasing water temperature. In the present work, experimental values on a film type packing are shown. Furthermore, a computer programme for the evaluation of Me from experimental data is dealt with which takes into account the correct energy and heat balances as well as the diathermic resistance in the liquid film. In addition, the question of how a correct material transfer number can be defined for the actual problem is discussed. (orig./TK)

27

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

28

A comprehensive approach to cooling tower design  

Energy Technology Data Exchange (ETDEWEB)

In this paper, a mathematical model for a counterflow wet cooling tower is derived, which is based on one-dimensional heat and mass balance equations using the measured heat transfer coefficient. The balance equations are solved numerically to predict the temperature change of air and water, as well as the humidity as a function of the cooling tower high. Experimental measurements on two pilot-scale cooling towers were carried out in order to analyze the performance of different cooling tower filling materials. Also, the performance of other cooling tower elements, such as droplet separators and water spray nozzles, was investigated in the pilot experiments. The flow distribution, i.e. the velocity field, upstream to the filling material was predicted using the three-dimensional version of the computational fluid dynamics (CFD) code Fluent/UNS, version 4.2. The calculated flow fields are presented for different distances between the inlet of the air and the filling material. In addition, the two-dimensional version of the CFD code Fluent/UNS, version 4.2, was applied to predict the external airflow around the cooling tower and the backflow in different weather conditions in summer and winter. The research project was carried out in connection to an industrial cooling tower installation. (author)

Milosavljevic, N.; Heikkilae, P. [Valmet Corporation, Air Systems, Turku (Finland)

2001-06-01

29

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

30

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)

31

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 106 fibers/liter) to 16.2 x 106 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 106 fibers; liter and 1.4 x 106 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

32

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1985-02-01

33

Keystone station cooling tower fill fouling  

International Nuclear Information System (INIS)

This paper reports on Keystone Station which is a coal-fired nine-mouth electric generating station located 50 miles northeast of Pittsburgh in western Pennsylvania, with two 850 MW supercritical pressure generating units. Main condenser and service water cooling is provided by two natural draft hyperbolic cooling towers per unit. Each of the four cooling towers is 325 feet tall and 247 feet across at the basin. Operation of the station began in 1967. A consortium of mid-Atlantic utilities owns Keystone Station, and it is operated by the Pennsylvania Electric Company

34

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The performance of a cooling tower was analyzed with various operating parameters tofind the minimum cold water temperature. In this study, optimization of operating parameters wasinvestigated. An experimental design was carried out based on central composite design (CCD) withresponse surface methodology (RSM). This paper presents optimum operating parameters and theminimum cold water temperature using the RSM method. The RSM was used to evaluate the effectsof operating variables and their in...

Ramakrishnan, Ramkumar; Arumugam, Ragupathy

2012-01-01

35

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

36

Adaptation of amoebae to cooling tower biocides.  

Science.gov (United States)

Adaptation of amoebae to four cooling tower Biocides, which included a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds (TBT/QAC), another QAC alone, and an isothiazolin derivative, was studied. Previously we found that amoebae isolated from waters of cooling towers were more resistant to cooling tower biocides than amoebae from other habitats. Acanthamoeba hatchetti and Cochliopodium bilimbosum, obtained from American Type Culture Collection and used in the previous studies, were tested to determine whether they could adapt to cooling tower Biocides. A. hatchetti was preexposed to subinhibitory concentrations of the four Biocides for 72h, after which they were tested for their resistance to the same and other biocides. C. bilimbosum was exposed to only two biocides, as exposure to the other two was lethal after 72 h. Preexposure to the subinhibitory concentrations of the Biocides increased the resistance of the amoebae, as indicated by a significant increase in the minimum inhibitory concentration (up to 30-fold). In addition, cross-resistance was also observed, i.e., exposure to one biocide caused resistance to other biocides. These results show that amoebae can adapt to biocides in a short time. The phenomenon of cross-resistance indicates that regularly alternating biocides, as is done to control microbial growth in cooling towers, may not be effective in keeping amoeba populations in check. On the contrary, exposure to one biocide may boost the amoebae's resistance to a second biocide before the second biocide is used in the cooling tower. Since amoebae may harbor Legionella, or alone cause human diseases, these results may be important in designing effective strategies for controlling pathogens in cooling towers. PMID:24190342

Srikanth, S; Berk, S G

1994-05-01

37

AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS  

Energy Technology Data Exchange (ETDEWEB)

Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and after each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.

Brigmon, R.; Leskinen, S.; Kearns, E.; Jones, W.; Miller, R.; Betivas, C.; Kingsley, M.; Lim, D.

2011-10-10

38

Upgrading the seismic performance of the interior water pipe supporting system of a cooling tower  

International Nuclear Information System (INIS)

This paper presents results from a numerical study that was performed in order to simulate the seismic behavior of the interior support system of the piping and cooling features of a cooling tower in one of the old power stations located in an area at the North-Western part of Greece. This cooling tower has a diameter of 60 m and a height of 100 m. The interior piping support system consists mainly of a series of nine-meter high pre-cast vertical columns made by pre-stressed concrete; these columns, together with reinforced concrete pre-cast horizontal beams that are joined monolithically with the columns at their top, form the old interior supporting system. This system represented a very flexible structure, a fact that was verified from a preliminary numerical analysis of its seismic behavior. The maximum response to the design earthquake levels resulted in large horizontal displacements at the top of the columns as well as overstress to some of the columns. The most important part of the current numerical investigation was to examine various strengthening schemes of the old interior support system and to select one that will demonstrate acceptable seismic behavior. (authors)

39

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

40

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

 
 
 
 
41

Kaiseraugst nuclear power station: meteorological effects of the cooling towers  

International Nuclear Information System (INIS)

Considerations of water conservation persuaded the German Government in 1971 not to allow the use of the Aar and Rhine for direct cooling of nuclear power stations. The criticism is often made that the Kaiseraugst cooling towers were built without full consideration of the resulting meteorological effects. The criticism is considered unjustified because the Federal Cooling Tower Commission considered all the relevant aspects before making its recommendations in 1972. Test results and other considerations show that the effect of the kaiseraugst cooling towers on meteorological and climatic conditions is indeed minimal and details are given. (P.G.R.)

42

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

43

Possible cooling tower designs and their economy  

International Nuclear Information System (INIS)

The supporting shells of natural-draught cooling towers make very high demands on calculation and construction. Of the possible constructions, reinforced-concrete cooling towers constructed with the aid of climbing forms are the only ones which appear to be functional and economical. THe choice of the meridian curve of the cooling tower shell, which may be a hyperboloid of revolution or, in a more recent construction, of bell shape, is of great importance. In very large cooling towers, bracing rings cannot be dispensed with, as they improve the buckling and vibrational behaviour of the shell. This type of construction is also more economical than cooling tower shell with continuously varying shell thickness. (orig.)

44

Optimization of cooling tower performance analysis using Taguchi method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study discuss the application of Taguchi method in assessing maximum cooling tower effectiveness for the counter flow cooling tower using expanded wire mesh packing. The experiments were planned based on Taguchi’s L27 orthogonal array .The trail was performed under different inlet conditions of flow rate of water, air and water temperature. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression were carried out in order to determine the effects of proce...

Ramkumar Ramakrishnan; Ragupathy Arumugam

2013-01-01

45

Studies on the conditioning of line-decarbonized cooling-tower make-up feedwater for use as secondary cooling water  

International Nuclear Information System (INIS)

Conditioned Danube water is used in the Gundremmingen nuclear power plant, units B + C, for cooling conventional cooling sites (service water) prior to its application as cooling-tower make-up feedwater. Conditioning is effected by decarbonization using lime (2Ksub(S8.2) proportional Ksub(S4.3); pH proportional 10) with subsequent dosing of hardness stabilizers. The pipelines of the service water system are made of non-alloy non-coated steel and the heat exchanger tubes are largely made of special-grade brass 71 and pure copper. The occurrence of sludge-like deposits in the heat exchanger tubes and strong, partly blister-type formation of deposits on the ferritic pipe surfaces during commissioning caused the examination of different conditioning methods in a test cooling facility while simulating real conditions at 'on-site' operation. One single product out of the range of conditioners tested did not exhibit the formation of sludge-type deposits on the heat exchanger tubes, thus rendering any extra chlorination unnecessary to-date. Assessment of the corrosion behaviour of the C-steel showed operation with decarbonized water at pH proportional 10 to be superior to those employing a reduced pH. (orig./RB)

46

The effects of natural winds on cooling towers  

International Nuclear Information System (INIS)

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

47

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

48

The Schmehausen cable net cooling tower  

International Nuclear Information System (INIS)

The prototype of a large cable net shell as a natural-draught cooling tower for the THTR-300 is presented. Results of wind tunnel tests and calculations are given, and the capacity is discussed. Design features of the main components are presented in illustrations and are described with regard to the construction process of the cooling tower. Finally, it is shown that the cable net cooling tower is a suitable construction for large dimensions and caving-in or seismic areas. (orig./HP)

49

Performance characteristics of counter flow wet cooling towers  

International Nuclear Information System (INIS)

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

50

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

51

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.)

52

BOD Limit in Synfuel Plants' Cooling-Tower Makeup.  

Science.gov (United States)

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...

D. J. Goldstein, O. Aiyegbusi

1982-01-01

53

Determination of the replacement cooling tower capability at the ETRR-2 research reactor  

Energy Technology Data Exchange (ETDEWEB)

The ETRR-2 replacement cooling tower capability has been evaluated by the thermal acceptance test performed in June 2003. All instruments used were calibrated prior to the test. The measured data are collected at regular intervals in accordance with the acceptance test code for water cooling towers of the cooling tower institute recommendations. Both the characteristic curve and the performance curve methods were used to evaluate the tower capability. The test results yield a tower capability of about 105% and so the tower is thermally accepted. (orig.)

El-Din El-Morshdy, S. [Atomic Energy Authority, Cairo (Egypt). Reactors Dept.

2004-08-01

54

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)

55

Crossed streams cooling tower with anti-freezing system  

International Nuclear Information System (INIS)

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

56

An investigation into a falling film type cooling tower  

Energy Technology Data Exchange (ETDEWEB)

A model for a falling film type cooling tower has been developed to investigate the effect of tower parameters as well as the effect of liquid-side thermal resistance on the tower performance. The energy equation is used to determine the temperature distribution across the liquid film. The heat and mass transfer processes between the liquid film and air bulk are described using three ordinary differential equations. The energy equation was solved using a finite difference Crank-Nicolson scheme. The heat and mass transfer equations were solved using the Runge-Kutta method. The results obtained show that an increase in tower characteristic KaV/L under the same conditions improves the tower performance. The converse is true in the case of increased water to air mass flowrate ratio, L/G. The Lewis number, Le, shows no significant effect on the tower performance. The effect of tower parameters as well as the water inlet temperature on the liquid-side Nusselt number and the tower effectiveness was also studied. The results show very insignificant changes in Nusselt number, whereas the effectiveness increases with increasing KaV/L and reduces with L/G, but very insignificant changes occur with Le. The present model is also compared with Merkel`s equation. Under the same conditions and with Le equal to unity, the results of the Merkel equation shows a smaller approach than that obtained by the present model. (Author)

Ibrahim, G.A.; Nabhan, M.B.W. [Bahrain Univ. (Bahrain). Dept. of Mechanical Engineering; Anabtawi, M.Z. [Bahrain Univ. (Bahrain). Dept. of Chemical Engineering

1995-11-01

57

Performance prediction of a cooling tower using artificial neural network  

International Nuclear Information System (INIS)

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

58

The water-saving and environmentally-minded utilization of waste heat as a substitute for cooling towers-Agrotherm  

International Nuclear Information System (INIS)

Since 1976 the conditions for the utilization of waste heat from power plants in agriculture has been investigated in different test plants in the F.R. of Germany. The system 'Agrotherm' is to substitute traditional cooling towers by closed underground pipe networks. The various investigations showed an overall increase of yield and premature harvest on acreages which had been heated by such pipe networks. The reactions of the various agricultures differ very much, so that a careful choice of sorts is necessary. Possibly considerable infestations of diseases must be expected. The article gives a summary of the most important results gained from the test plants. (KH)

59

Energy savings: SCAM a new type of cooling tower  

International Nuclear Information System (INIS)

Counter current natural draft cooling towers equipped with the device for cold water recovery and the adapted hydraulic circuit studied by CEM- (Compagnie Electro-Mecanique) SCAM system lead to a decrease in pumping energy. For a 1300 MW nuclear power plant energy saved is around 6 MWe, at the cost of energy in France in 1982 saving is F 4 500 000 which compensate for higher investment. They will be used in Golfech power plant; with a high of 178.5 m they will by the highest cooling towers in the world

60

Repair and completion of damaged cooling tower  

International Nuclear Information System (INIS)

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

 
 
 
 
61

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

62

Heat transfer during phase change. Evaporation. Application to cooling towers  

International Nuclear Information System (INIS)

Evaporation near a water sheet, without convection, is considered. The displacement of water molecules in the gaseous phase, due to concentration gradients, is especially studied. This displacement governs the development of evaporation. The calculation is made to derive the velocity of water evaporation as a function of the partial pressure of the surrounding air, the temperature and physical properties of the air and steam. Diffusion laws are used. The calculation is applied to cooling towers, according to Merkel theory

63

Interception and retention of simulated cooling tower drift by vegetation  

International Nuclear Information System (INIS)

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

64

Development and application of a cooling tower plume model  

International Nuclear Information System (INIS)

With the integral-type cooling-tower plume model, the integral equations are directly derived from the partial conservation equations of hydrodynamics. Development activities were based on an integral system established for the simulation of dry fluegas jets with a supplementation by transport equations for water in the form of steam and condensate describing the conservation of overall water content. The energy equation was extended to cover the impacts of heat release by condensation. (DG)

65

Comparative experimental drift study between a dry and adiabatic fluid cooler and a cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health reasons. These objections make the installation of the cooling towers difficult and penalize the COP of the cooling plants. The dry and adiabatic fluid cooler works as a standard fluid dry cooler enhancing the dry cooler's capacity with adiabatic pre-cooling of the air intake. The objectives of this work were twofold: the first one was to review the available drift test methods usually used on cooling towers, and the second one was to carry out drift measurements on a dry and adiabatic fluid cooler and on a cooling tower of similar capacity working in real facilities. No drift was registered on the dry and adiabatic fluid cooler when using the sensitive paper drift test method, while a drift of 0.0023% was measured in the cooling tower. (author)

Lucas, M.; Martinez, P.J. [Departamento Ingenieria de Sistemas Industriales, Universidad Miguel Hernandez, Avda. de la Universidad, s/n, 03202 Elche, Alicante (Spain); Viedma, A. [Departamento de Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena, Campus Muralla del Mar, Dr. Fleming, s/n, 30202 Cartagena (Spain)

2008-11-15

66

Toward to the control system of mechanical draft cooling tower of film type  

Energy Technology Data Exchange (ETDEWEB)

For changing atmospheric conditions the mathematical model of a control system of a mechanical draft cooling tower has been developed. The model includes a heat and mass transfer processes between water films and turbulent damp air flow at quasi-state approximation. Various regimes of cooling tower performance are compared and the optimization method is proposed. (author)

Fisenko, S.P.; Petruchik, A.I. [National Academy of Sciences of Belarus, Minsk (Belarus). A V Luikov Heat and Mass Transfer Inst.

2005-01-01

67

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

68

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

69

Stiffened cooling tower shells of reinforced concrete  

International Nuclear Information System (INIS)

Presenting a kinetic method to derive the linear buckling and vibration problem of unstiffened and stiffened hyperboloidal cooling tower shells of reinforced concrete a parametric study is carried out using finite elements. The following parameters are varied: the type of axisymmetric load, the main geometric dimensions, the curvature of the meridional function and the type of stiffening, that means number, dimension and arrangement of meridional ribs and stiffening rings. The numerical results are interpreted. The tendencies recognizable are formulated and summarized in forme of recommendations. (orig.)

70

First annual report on weather modification effects of cooling towers  

International Nuclear Information System (INIS)

Single cooling towers emit as much as 1000 MW of sensible and latent heat to the atmosphere. Planned energy centers or power parks may contain clusters of cooling towers which emit a total of 100,000 MW. Heat releases of this magnitude have the potential to significantly alter local weather. Cooling towers can also alter the local environment by the production of fog and clouds, and the deposition of drift salts. A basic one-dimensional mathematical model is presented for plume and cloud growth in the vicinity of cooling towers. Since the cooling tower emissions are usually constant with time, at least over time periods less than four or five hours, the steady-state assumption is good. Phenomena such as multiple plume merging and changes in the environmental air surrounding the plume are accounted for only by crude parameterization. Applications in analysis of the environmental effects of cooling towers at fossil-fuel and nuclear power plants are reported

71

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

72

Studies of cooling tower components on the Mistral test bench  

International Nuclear Information System (INIS)

The conception of a humid air cooling tower with natural or forced draught, requires the knowledge of the thermal and aerodynamic exchange surfaces performances. Several points, among which the distribution nozzles and drift eliminators efficiencies, or the mechanical behavior of the components, should be considered. In order to be able to test this type of equipment and analyse its behavior, ELECTRICITE DE FRANCE set up in 1987 of a large dimensions test bench: MISTRAL. The investigations performed over the 3000 working hours of MISTRAL concern mainly the optimization of the counterflow and crossflow exchange surfaces proposed by the industrial cooling tower equipment suppliers. The quality of the experimental results is assured by the implementation of an extensive instrumentation on the air and water circuits, and by a severe control of the tests conditions

73

Natural draft cooling tower with shell disconnected from the substructure  

International Nuclear Information System (INIS)

The aim of this paper is the analysis of results of a research done by Electricite de France, concerning a new type of cooling tower. The traditional structure (i.e. a hyperbolic shell supported by X shaped or diagonal columns) is replaced by two independent structures: the shell, becoming a self-contained structure, the lower rim being stiffened by an annular beam; the substructure, resting on the soil. This new type of cooling tower has an improved thermal performance due to the increase of the area of air entrance. Bearing pads are provided between the lower ring beam of the shell and the substructure. Any differential settlement can be coped with by jacking. The water distribution structure can be laid out so as to benefit from advantages offered by the presence of the stiff ring and columns of the substructure

74

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.

75

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

International Nuclear Information System (INIS)

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

76

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

Energy Technology Data Exchange (ETDEWEB)

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

Lucas, M.; Martinez, P.J. [Departamento Ingenieria de Sistemas Industriales, Universidad Miguel Hernandez, Avda. de la Universidad, s/n, 03202 Elche (Spain); Viedma, A. [Departamento de Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena (Campus Muralla del Mar), Dr. Fleming, s/n, 30202 Cartagena (Spain)

2009-03-15

77

Thermal performances investigation of a wet cooling tower  

International Nuclear Information System (INIS)

This paper presents an experimental investigation of the thermal performances of a forced draft counter flow wet cooling tower filled with an 'VGA' (Vertical Grid Apparatus) type packing. The packing is 0.42 m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross sectional test area of 0.0222 m2 (0.15 m x 0.148 m). This study investigates the effect of the air and water flow rates on the cooling water range as well as the tower characteristic, for different inlet water temperatures. Two operating regimes were observed during the air water contact, a pellicular regime (PR) and a bubble and dispersion regime (BDR). These two regimes can determine the best way to promote the heat transfer. The BDR regime seems to be more efficient than the pellicular regime, as it enables to cool larger water flow rates. The comparison between the obtained results and those found in the literature for other types of packing indicates that this type possesses very interesting thermal performances

78

Emission of air-borne pollutants from cooling towers  

International Nuclear Information System (INIS)

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

79

Engineering evaluation of magma cooling-tower demonstration at Nevada Power Company's Sunrise Station  

Science.gov (United States)

The Magma Cooling Tower (MCT) process utilizes a falling film heat exchanger integrated into an induced draft cooling tower to evaporate waste water. A hot water source such as return cooling water provides the energy for evaporation. Water quality control is maintained by removing potential scaling constituents to make concentrations of the waste water possible without scaling heat transfer surfaces. A pilot-scale demonstration test of the MCT process was performed from March 1979 through June 1979 at Nevada Power Company's Sunrise Station in Las Vegas, Nevada. The pilot unit extracted heat from the powerplant cooling system to evaporate cooling tower blowdown. Two water quality control methods were employed: makeup/sidestream softening and fluidized bed crystallization. The 11 week softening mode test was successful.

1980-11-01

80

A numerical simulation of heat transfer in evaporative cooling towers  

Science.gov (United States)

A phenomenological analysis was developed for the processes which occur within an evaporative cooling tower. The analysis includes the basic principles of mass, momentum, and energy conservation and empirical elationships for component characteristics such as transfer and pressure drop coefficients. A computer model which simulates the processes occurring in evaporative cooling towers was developed. The results of this computer model are compared to field data to verify the analysis and the computer modeling. The computer model may be used to analyze the performance of existing towers or to predict the performance of alternative tower designs.

Benton, D. J.

1983-09-01

 
 
 
 
81

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

82

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

International Nuclear Information System (INIS)

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

83

CTP method - diagnostic method for control of cooling tower operation  

International Nuclear Information System (INIS)

Optimal operation of cooling towers of thermal systems, such as fossil-fired power plants, nuclear power plants, heating plants, thermal systems in process and petro-chemical industry, significantly raises the efficiency of the entire systems. With the reconstruction of cooling towers and introduction of new technologies significant economic and ecologic profits could be expected. The increased system efficiency after cooling tower reconstruction is estimated from 2 to 5%, what is an enormous amount of energy and money saving considering the output power of such systems. Within the frame of the EU Copernicus Project 'OCTEBAMA', a modification of the described method was performed. (orig.)

84

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.)

85

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

86

An improved model for the analysis of evaporative counterflow cooling towers  

International Nuclear Information System (INIS)

A rigorous approach is applied to the thermal design of counterflow cooling towers, by obviating the six simplifying assumptions in the classical Merkel method. It is indicated that: (1) neglecting evaporation losses is the main cause of inaccuracy in the Merkel results; (2) the error in the Merkel method may reach 12%; and (3) the present solution provides a more accurate and more ecologically favorable prediction for the cooling water tower. (Auth.)

87

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

88

Cooling tower environmental impact prediction in the case of nuclear power plant mixed cooling system  

International Nuclear Information System (INIS)

This paper deals with nuclear power plant mixed cooling system and problem of environmental impact predictions. Comparation is made with environmental impact of cooling towers working in recirculation cooling system

89

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)

90

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

91

Dry cooling towers, a comparative analysis and possibilities for their implementation in Macedonia  

International Nuclear Information System (INIS)

The need for supplying the great quantities of additional water for compensation of water looses in circulating cooling systems in thermal power units represent a distinct problem. In cases when this problem result in limitation of power energy production, the solution of this problem can be obtained using new technological solutions for cooling using dry cooling towers, system HELLER, which have no need for additional water for compensation of evaporating looses. (Authors)

92

Influence of water droplets from a cooling tower vapour cloud on the deposition of radioactive compounds from waste plumes from nuclear power stations  

International Nuclear Information System (INIS)

Vapour clouds from cooling towers contain in their visible part condensation droplets which rarely exceed a total quantity of 3g/m3. The diameter of these droplets is on average 10 ?m. They can only reach the ground if they are trapped by coalescence with raindrops passing through the cloud and entrained in their downward path. If the radioactive waste air plume becomes mixed with the visible part of the vapour cloud from the cooling tower, the condensation droplets can easily acquire radioactive contamination, resulting during rainy weather in a deposition of radioactive emissions from the chimney, the level of which will vary appreciably from that obtained without any mixing of the waste air plume with the vapour cloud. Some of the drops of spray emitted by the cooling tower may also reach the ground in view of their greater size (up to a few 100 ?m). They will only have a radioactive content, if they pass through the waste air plume. The short-term deposition rate is discussed: from washout coefficients which are derived, calculations are made of the short-term deposition of gaseous iodine. The long-term effects (i.e. accumulation of deposited iodine at a particular point) are also discussed. (U.K.)

93

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. PMID:8250551

Srikanth, S; Berk, S G

1993-10-01

94

Short-term pilot cooling tower tests  

Energy Technology Data Exchange (ETDEWEB)

Two major problems are associated with the use of cooled geothermal water as coolant for the 5 MW(e) pilot plant at Raft River. They are: (1) a scaling potential owing to the chemical species present in solution, and (2) the corrosive nature of the geothermal water. Tests were conducted to obtain data so that methods can be devised to either reduce or eliminate effects from these problems. Data show that scaling can be prevented, but only by using a high concentration of dispersant. Pitting data, however, are not as conclusive and seem to indicate that pitting control cannot be realized, but this result cannot be substantiated without additional experimentation. Results also demonstrate that chromate can be removed by using either chemical destruction or ion exchange. Whichever method is used, EPA discharge limits for both chromate and zinc can be achieved. A preliminary economic analysis is presented.

Suciu, D.F.; Miller, R.L.

1980-01-01

95

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

International Nuclear Information System (INIS)

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

96

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

97

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

98

Predicted climatology of cooling tower plumes from energy centers  

International Nuclear Information System (INIS)

A one-dimensional plume and cloud growth model is applied to four months of radiosonde observations from Nashville, using as initial conditions the plume from single large cooling towers with waste heat outputs of 103, 104 and 105 MW, and a complex of cooling towers with a total waste heat output of 105 MW. Estimates of average annual plume rise from the four energy sources are 580, 1180, 2460 and 780 m, respectively.The predicted plume rise, visible plume length and cloud formation are given as functions of time of day, year and weather type. For example, a cloud forms at the top of the plume from the 103 MW tower in 65% of the morning soundings during which ground level fog was observed. A cloud is predicted to occur 95% of the time at the top of the plume from the single 105 MW tower. It is found that if the towers in an energy center are separated by a distance greater than the average plume rise from one tower, then plume merging is minimized. Observations from TVA's Paradise steam plant are used to test the predictions of visible plume length from a single 103 MW tower

99

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

International Nuclear Information System (INIS)

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

100

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

 
 
 
 
101

Calculation of cooling tower plumes for high pressure wintry situations  

International Nuclear Information System (INIS)

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

102

Results of a cooling tower performance test and analysis project  

International Nuclear Information System (INIS)

Recent measurements of the heat and mass transfer characteristics on cooling tower fills (packings) are reported. Results include laboratory-quality data from a 1.5 MW (thermal) facility constructed for this effort, and corresponding full-scale data from 10 MW (thermal) cooling tower cells. State-of-the-art models of the heat and mass transfer process that vary in refinement and complexity are described. These models, which are being used to correlate the data, are assessed. This assessment is aimed at improvement in predictive ability compared to using conventional Merkel analysis

103

Cooling tower environmental impact prediction at inland nuclear power plant  

International Nuclear Information System (INIS)

As a heat dissipation system, natural-draft cooling tower is usually used for inland nuclear power plant. The waste heat of plant is transferred to atmosphere primarily by evaporating, which will bring out the potential adverse impacts,including visible plume, shadow of plume,ground deposition of drift droplet and noise. In this paper, the environmental impact prediction model of cooling tower, based on SACTI program recommended by NRC, was used to predict impacts of current three inland nuclear power sites (Hunan, Hubei and Anhui provinces). To illustrate the compatibility of SACTI in China, the prediction results were compared with GGNS power station in U.S. (authors)

104

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

105

Effects of thermal discharges from large cooling towers  

International Nuclear Information System (INIS)

The results can be summarized as follows: Direct effects on the local climate at ground level on account of thermal discharges of the cooling towers customary today are small, and they do not represent a problem to meteorological environmental protection. This is to be attributed to technical measures such as sufficient height of the cooling towers, preventing the discharge of large drops, enabling the plumes to reach big heights. On the basis of existing knowledge, it can also be said that waste heat discharged via wet cooling towers with cooling capacities up to 3,000 MWe, which are already quite customary these days, do not bring disadvantages for the surrounding area. This also applies to several cooling towers of similar size put together. Small changes in some meteorological elements in the immediate vicinity can be just as little looked upon as hazards to the environment as the low increases in temperature and precipitation in major towns and industrial, densely populated areas, which - true to say - cannot be compared but which have been known for a long time. (orig.)

106

Study of the comparative costs of five wet/dry cooling tower concepts  

Energy Technology Data Exchange (ETDEWEB)

The projected cost of five alternative dry/wet power plant heat rejection concepts was studied under conditions imposed by hypothetical use in association with the San Juan Plant Unit 3, a 550-MWe facility currently under construction near the ''Four Corners'' area of New Mexico. The five alternative concepts were: integrated dry/wet tower; separate dry and wet towers; metal fin-tube induced draft tower with deluge water augmentation; plastic heat exchanger tower with deluge water augmentation, and metal fin-tube/deluge augmentation tower with an intermediate ammonia evaporation-condensation condenser and the cooling tower. The integrated dry/wet tower concept, already chosen for service at San Juan Unit 3, was included for reference purposes. All concepts were conceptually designed and estimated using the same bases and employing uniform practices. Each concept was assumed to use all water allocated for consumptive use in Unit 3. The cost estimates obtained showed the following descending order of ''comparable capital cost'': separate dry/wet; metal fin-tube/deluge; integrated dry/wet; plastic tube/deluge; and metal fin-tube/deluge/ammonia. The results indicate that two of the advanced concepts considered, i.e., the plastic tube/deluge concept and the metal fin tube/deluge/ammonia concept, can possibly reduce the overall costs of dry/wet cooling under conditions imposed by the site considered. It was recommended that these two concepts receive additional attention by the ERDA Dry Cooling Tower Program and industry to further quantify their potential benefits and demonstrate their performance and reliability.

Zaloudek, F.R.; Allemann, R.T.; Faletti, D.W.; Johnson, B.M.; Parry, H.L.; Smith, G.C.; Tokarz, R.D.; Walter, R.A.

1976-09-01

107

Cooling tower and plume modeling for satellite remote sensing applications  

Energy Technology Data Exchange (ETDEWEB)

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

Powers, B.J.

1995-05-01

108

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

109

Natural-draught dry cooling tower for steam power plants  

International Nuclear Information System (INIS)

The problem of making natural-draught cooling towers for large steam power plants as simple, compact, and economical as possible can be solved by a combination of well-known structural features: The condenser elements, which are designed as stacks of plates with corrugated surfaces, are arranged in the form of a truncated pyramid enlarged at the top. In the cooling air flow, there are openings for feeding in superheated gas from the lower part of the cupola. (HP)

110

Boundary working regimes of condense-type turbine K-200-130 in case of using wet and dry cooling towers  

International Nuclear Information System (INIS)

Usage of wet cooling towers is connected with utilisation of considerable quantities of water with aim to cover the evaporation looses. The usage of di-y cooling towers in energy power stations in cases with modified temperate continental climate, water supply problems and ecological limitations can be applicable. Working data Of cooling towers in these climate conditions are estimated through parametric analyse using appropriate mathematical modelling of working processes. (Author)

111

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

112

Application of mechanical draft cooling tower in inland nuclear power plants  

International Nuclear Information System (INIS)

This paper described the nuclear power plant related design criterion classification of mechanical draft cooling tower used in inland nuclear power plant ultimate heat-sink systems, analyzed and summarized the special design and construction requirements of nuclear-classified mechanical draft cooling tower, and brought forward the qualification procedure of equipment in such cooling tower, and finally proposed a reference and guide for the design and development of domestic nuclear-classified mechanical draft cooling tower. (authors)

113

Temperature inversion decreases cooling effect of high natural-draught towers  

International Nuclear Information System (INIS)

The problems are discussed of the effect of temperature inversion on the cooling efficiency of high towers with natural draught. The methods are outlined of calculating the effect of temperature inversion on the temperature of cooled-down water. The locality of the Temelin nuclear power plant is said to be susceptible to the formation of inversion. It is thus necessary to bear in mind a permanent adverse effect on the cooling tower efficiency. The experience from cooling towers of a similar capacity abroad shows that insufficient cooling detected is many times greater than shown by calculations using the technique applied so far. It is thus necessary to consider the existing assessment of the temperature inversion effect on the cooling tower efficiency in the Temelin nuclear power plant to be unsatisfactory. It is recommended that the specific climatic conditions of the site rather than universal conditions should be taken into consideration, such as air temperature 15 degC and humidity 70%. (Z.M.) 1 tab., 8 figs., 6 refs

114

Geodesy work in the construction of cooling towers of the Temelin nuclear power plant  

International Nuclear Information System (INIS)

The specifications are described of the cooling tower foundations, the bottom part of the flue chimney and of the cooling tower casing. In view of the cooling tower configuration, the ground control points inside the tower were selected in the pit bottom and the layout and check were performed of the inner tower wall. The methodology of measuring the basic layout network, and of laying out up to the fiftieth (ca. 80 m) and from the 70th (106 m) strip is described. The measurement results are computer-processed. The accuracy is assessed of the cooling tower construction in the Temelin nuclear power plant. (E.J.). 1 fig., 5 refs

115

Modeling oscillatory fouling in enhanced tubes in cooling tower systems  

Science.gov (United States)

This paper is concerned with the development of a new approach to model the fluctuation of fouling in general. The proposed modeling concept is to split a property into a mean variable and a fluctuating variable. The goal is to investigate the oscillatory characteristic of fluctuating fouling resistance. Long-term fouling data collected from seven 15.54 mm ID copper, helically ribbed tubes with water velocity at 1.07 m/s in a cooling tower system were used to present oscillatory behaviors. An uncertainty analysis indicates that a minimum water temperature difference of 3.0°C between inlet and outlet of each test tube is needed to observe the oscillatory behavior of fouling data. The frequency of fluctuation is independent of tube interior geometries on which fouling deposit develops; the amplitude of fluctuation is related to tube interior geometries and is a function of the ratio of rib pitch to rib height. There are two ranges of amplitude of fluctuation of fouling characteristics based on internal dimensions: linear range and non-linear range. A series of semi-theoretical amplitude correlations as a function of the ratio of rib pitch to rib height were developed. They were applicable to different internally ribbed geometries within the dimensional range in the study.

Wu, Jie; Zhang, Zhengjiang; Cheng, Lin; Li, Wei; Xu, Zhiming

2011-05-01

116

Further investigation on the performance 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 the previous model we presented [Qi Xiaoni, Liu Zhenyan, Li Dandan. Performance characteristics of a shower cooling tower. Energy Convers Manage 2007;48(1):193-203.], three critical assumptions were made to reduce the complexity and computational time, which can also reduce the models' accuracy. Accurate modelling of the operating process is a determining factor both for designing the shower cooling tower (SCT) and for optimising its operation. In this paper, we derive a new model without applying the three assumptions. According to the condition of the outlet air, the governing equations consider two cases, including the supersaturated and unsaturated states. This model is used to predict the performance of a full scale SCT located in China with different conditions for validation. The differences in the heat and mass transfer analyses of the two models are described at different atmospheric conditions

117

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

International Nuclear Information System (INIS)

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

118

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

119

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

International Nuclear Information System (INIS)

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

120

The results of the measurements of mass- and heat-transfer in the wet cooling tower  

International Nuclear Information System (INIS)

These are the results of our investigations carried out on a packing inside a wet cooling tower for the purpose of studying the mass and heat transfer at the counterflow of water and humid air. The measurements on the experimental tower of the corresponding mathematical model reflect the average coefficient of mass and heat transfer for the unity of the active volume. Further the measurements of pressure drop at the air flow were carried out and thus the coefficient of aerodynamic losses were obtained. The results of measurements are given in the corresponding equations with the dimensionless numbers and diagrams. They will be of great use for the planning of new cooling towers. (author)

 
 
 
 
121

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

122

Thickness cracks in R.C. hyperbolic cooling towers  

International Nuclear Information System (INIS)

Imprecise construction work might cause imperfection in the shell of R.C. hyperbolic cooling towers. By considering the three directions concrete fracture model and by using elements in finite element analysis which could crack in three directions, it could be shown that in imperfect shell, the thickness cracks occur at the end of the weight and thermal loads. In the other words, the inside and outside of the concrete shell separate. The number of such cracks rises up by increasing the imperfection in the cooling tower shell. This increase in the number of cracks could multiple when two concavity and convexity imperfections happen consecutively. Since there is not any reinforce bar for preventing of such cracks, so it must be avoided by precise construction work and by modifying the participating thermal load factor in combining loads

123

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 atmospanges 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)

124

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.)

125

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

International Nuclear Information System (INIS)

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

126

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.)

127

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)

128

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

International Nuclear Information System (INIS)

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

129

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

130

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1984-01-01

131

Specific features of construction process of NPP prestressed cable cooling tower  

International Nuclear Information System (INIS)

Design and technology of construction of prestressed cable cooling tower at the Schmehausen NPP with INIR-300 reactor is described. Reinforced concrete pylon of 181 meter height, on which special cable grid is fixed , forms the basis of the cooling tower. The cable grid strength is provided with two ring steel diaphragms. The cable grid is lined by aluminium corrugated panels 1 mm thick. Experience of operation of prestressed cable cooling tower has demonstrated high construction reliability

132

Effect of column length on buckling factors of R.C. hyperbolic cooling towers  

International Nuclear Information System (INIS)

In this research, the bucking of R.C. cooling towers of Shazand power plant as a typical cooling tower has been studied by using VGB recommendations due to wind load. Infinite element analysis ANSYS 5.4 was used. The effect of columns on global buckling of the R.C. cooling towers has been ignored in most codes of practices except ACI. According to this research, in cooling towers with long columns, not only the buckling factors decrease considerably but in the first modes the columns buckle instead of the shell

133

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.

2000-12-01

134

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-07-15

135

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

International Nuclear Information System (INIS)

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

136

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

International Nuclear Information System (INIS)

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

137

Field Scale Transport of Chromate in Groundwater From Cooling Tower Wastes  

Science.gov (United States)

Chromate (Cr(VI)) was used extensively in evaporative cooling systems to prevent corrosion and scale formation. Waters from the cooling systems were discharged to ponds that were intended as evaporation ponds, but there were instances where the wastewaters infiltrated into the soil and released chromate to groundwater. Cooling tower discharges containing chromate also have elevated salt concentrations compared to the ambient groundwater because of the intended evaporative cooling process. Density driven flow and emplacement of contaminated brines should thus be expected. This conceptual model is being evaluated by the analysis of field data at two natural gas compressor facilities in the deserts of southeastern California. These facilities continuously released chromate containing water to unlined evaporation ponds for more than a decade, and subsequent investigations have identified groundwater plumes containing chromate. At one site, extensive remediation over a 15 year period has limited the plume migration but has not reduced groundwater concentrations. At the other site, density-stratified flow is observed. While there are uncertainties in the amounts released, the data available at these sites suggest that remedial approaches based on groundwater extraction are not effective in removing the source of chromate contamination from emplaced pockets of highly concentrated cooling tower discharge. Long term data sets collected during site investigations and remediation are valuable sources of data on field scale transport of highly mobile contaminants such as chromate.

Gladding, S. M.; Hunt, J. R.

2007-12-01

138

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

International Nuclear Information System (INIS)

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

139

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

Energy Technology Data Exchange (ETDEWEB)

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

Paller, M.H.

1991-02-01

140

A computer code for particular operating conditions of wet cooling towers  

International Nuclear Information System (INIS)

In most cases, normal operation of wet cooling towers can be described with a one dimensional model because the flows are practically uniform. Nevertheless, more accurate calculations are sometimes requested. Packing thickness is not always constant. And the antifreeze system which consist in putting the whole water flow on one part only of the packing or in closing a part of the air inlet leads to non-uniform operating conditions. ETHER computer code was developed for the studies of non-uniform operating conditions of counter-flow natural draft wet cooling towers. ETHER is a bidimensional axisymetric code which solves Navier-Stokes equations with a method of finite differences for the air flow in a region limited by the inlet and the outlet of the tower. Water, flow, packing thickness, cold rain height and inlet air velocity are given in every mesh. The only experimental correlations needed are those of heat and mass transfer and those of head loss in the packing. With a time of computation from 20 s to 400 s, the code provides air velocities, pressures and the profile of cold water temperature

 
 
 
 
141

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)

142

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

143

Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower  

International Nuclear Information System (INIS)

This paper deals with an experimental analysis of simultaneous heat and mass transfer phenomena between water and air by direct contact in a packed cooling tower. The tower is filled with a 'VGA.' (Vertical Grid Apparatus) type packing. The packing is 0.42 m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross-sectional test area of 0.15 m x 0.148 m. This study investigates the effect of the air and water flow rates on the global heat and mass transfer coefficient as well as the evaporation rate of water into the air stream, for different inlet water temperatures. Two operating regimes were observed during the air/water contact inside the tower, a Pellicular Regime (PR) and a Bubble and Dispersion Regime (BDR). These two regimes can determine the best way to promote the heat and mass transfer phenomena in such device. The BDR regime seems to be more efficient than the Pellicular Regime, as it enables to achieve relatively higher values of the global heat and mass transfer coefficient and larger water evaporation rates. The comparison between the obtained results and some of those available in the literature for other types of packing indicates that this type possesses good heat and mass transfer characteristics.

144

Simulation of the process of aerosol washout from the vent pipe plume of a nuclear power station on interaction with the steam-air plume of a water-cooling tower  

Energy Technology Data Exchange (ETDEWEB)

Based on results of mathematical simulation and laboratory modeling, estimates are obtained for the effect of the washout of aerosol and its deposition on the surface of the earth in mixing of the plumes from the vent pipe and cooling tower of a nuclear power station (NPS).

Ivanov, V.V.; Fisenko, S.P. [A.V. Luikov Institute of Heat and Mass Transfer, Minsk (Russian Federation)

1994-05-01

145

Deposition and corrosion phenomena on aluminum surfaces under deluged dry cooling-tower condisions. Interim report  

Energy Technology Data Exchange (ETDEWEB)

Deposition and corrosion on aluminum heat exchanger surfaces resulting from deluge in wet/dry cooling towers is simulated in a laboratory Corrosion/Deposition Loop (CDL). Heat exchanger deposition buildup was found to be linearly dependent on concentration factor and number of wet/dry cycles. Deionized water rising after deluge reduced rate of deposition. Laboratory data obtained from CDL relates directly to operation of the Advanced Concepts Test (ACT) demonstration cooling tower. Technology transferable to ACT shows that deposition from supersaturated solution can be effectively controlled by attention to water chemistry, pH, water conditioning, and good heat transfer design. The additional mechanism of deposition by water film evaporation is effectively managed by soft water rinsing and uniform surface wetting. Exposure of a model TRANE surface (the ACT wet/dry exchanger) produced short-term deposition extrapolating to 0.011 mm buildup in three years. Studies continue to verify 4X as maximum cycles of concentration through control of water chemistry and rinsing after deluge. Deluge water used at ACT facility is sufficiently aggressive to warrant use of Alclad to extend tube service life.

Wheeler, K.R.; May, R.P.; Douglas, J.G.; Tylczak, J.H.

1981-07-01

146

Cooling water systems performance evaluations  

International Nuclear Information System (INIS)

All nuclear power station cooling water systems are required to transfer heat from both safety and non-safety related structures, systems, and components to the ultimate heat sink (UHS). Examples of an UHS include rivers, lakes, cooling ponds, or cooling towers. Cooling water systems are designed and analyzed to meet minimum system performance requirements by delivering required flows to components based on a specific UHS temperature. If the maximum UHS temperature or any minimum flow limits are violated, the design basis on the safety related portion of the system or component could be exceeded, and the assumptions used in the plant safety analyses could be invalidated. The authors' company has completed programs which have been successfully implemented at several nuclear power stations to raise the design basis UHS temperature and to establish cooling water system flow requirements and flow capacities. This paper addresses the evaluation of cooling water system performance and its degradation and presents lessons learned from the implementation of these programs

147

Girassol, Riser Towers for ultra deep water  

Energy Technology Data Exchange (ETDEWEB)

This is a brief presentation of the technical concept developed by ALTO MAR GIRASSOL (AMG) for the Girassol umbilical and flowlines system. In 1998 AMG was awarded a contract by Elf Exploration Angola for the engineering, procurement, construction and installation (EPCI) of the umbilical and flowline system. The technical concept is based around the use of sealine bundles and self-supporting hybrid riser towers which carry the production, water injection, gas injection, gas lift and service lines. The items discussed are: (1) selected field layout, (2) seabed flowlines, hybrid riser system, umbilicals, export lines, installation plan and overall project schedule.

Rougier, Regis

1999-07-01

148

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.)

149

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.

150

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)

151

The influence of atmospheric conditions on the cooling tower plume of nuclear power station  

International Nuclear Information System (INIS)

The paper deals with the effect of atmospheric conditions - relative humidity, wind velocity, temperature and temperature gradient on the visible plume. For estimating cooling tower plumes, used was made of verified mathematical model. (author)

152

The influence of method of cooling tower operation on plume length  

International Nuclear Information System (INIS)

By means of a simple procedure it is possible to estimate the length of cooling tower plumes with direct cooling operation compared with closed circuit operation. As a specific example it is demonstrated that direct cooling operation causes considerably shorter plumes than closed circuit operation. (orig.)

153

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)

154

Comparison between wind and solar effects on static stresses in natural draught cooling tower  

International Nuclear Information System (INIS)

A thermal simulation of a cooling tower shell under sunshine was carried out. The associated constraints are virtually isotropic and change signs from one side of the shell to the other. The comparison with a schematic study of wind plus inherent weight shows that the thermal constraints are in the order of one third of the maximum constraints. The results presented correspond to the structure of a proposed 1300 MW type cooling tower 165 metres high

155

3D simulation of air flow and heat transfers in cooling towers  

International Nuclear Information System (INIS)

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

156

Effect of output heat from WWER-1000 type nuclear power plants on evaporation in cooling towers  

International Nuclear Information System (INIS)

The paper deals with problems of the large amounts of waste heat and related problems of large steam discharges from cooling towers which will arise for the WWER-1000 NPP units to be erected in the CSSR. As all these units will be operated in a cogeneration mode, a study has been made to calculate evaporation from a cooling tower as a function of atmospheric conditions of the environment and of the heat power bleeded off the unit. (author)

157

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

158

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 ismall 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.

159

Conversion of water towers – an instrument for conserving heritage assets  

Directory of Open Access Journals (Sweden)

Full Text Available Water towers are symbolical landmarks that refer to the industrialization. The oldest water towers are technical and industrial assets whose current and future evolution is a sensitive matter as a result of the economic context that brought about the closing of numerous industrial enterprises and abandoning infrastructure assets, including water towers. Some water towers were included on the national cultural-heritage lists across the world, thanks to the manifold values they incorporate (technological, historical, architectural, esthetical, among others. In this context, it has become necessary to convert them, with the twofold purpose of conserving them and assigning them a new function, for the local community members. Although there are numerous models for good practice in the conversion of water towers in several European countries, in Romania their reuse is a difficult process, most of the time burdened by shortcomings of legislation or lack of financial support. The study’s main purpose is to present reasons for the conversion of water towers and to highlight several good practice models, as well as to present several water towers with a high potential for conversion.

Andreea-Loreta Cercleux

2014-06-01

160

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

 
 
 
 
161

Importance of the inlet pressure loss of a natural-draught dry cooling tower  

Energy Technology Data Exchange (ETDEWEB)

The pressure losses on the air side at the inlet area of a natural-draught dry cooling tower, occurring on flowing through the heat transmitting elements, and the pressure losses at the outlet are in balance with the buoyancy of the heated air column inside the tower. Dependent on the size of the actual inlet loss, an operational condition of the cooling tower is determined which can differ considerably from the calculated condition. Model tests have been carried out to obtain data on the amount of this proportion of the losses. The results show a dependence on the geometric tower parameters and on the arrangement of the cooling elements. From characteristic range calculations, the operational conditions which depend on the inlet pressure drop can be determined.

Buxmann, J.; Voeller, G.

162

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

Energy Technology Data Exchange (ETDEWEB)

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

NONE

1998-09-01

163

Site and design temperature related economics of nuclear power plants with evaporative and non-evaporative cooling tower systems  

International Nuclear Information System (INIS)

A comprehensive cost and evaluation study is presented which has been conducted for nuclear power plants using cooling systems which employ either evaporative or non-evaporative cooling tower types. The primary purpose of the study is to develop the economics for two 1000 MW(e) light water reactor power plants, one built on a site requiring non-evaporative cooling, the other built on a site where sufficient water is available to support the requirements of evaporative cooling systems. The study, while specific to two sites selected in New York State by the New York State Energy Research and Development Authority, is also of a general nature so that it may be applied to other locations. It takes into account essential variables such as ambient temperature, water availability, water cost, railway and highway accessibility, proximity to electric load centers, and normal ecological restraints specific to the two sites

164

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.)

165

Updating of a finite element model of the Cruas 2 cooling tower  

International Nuclear Information System (INIS)

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

166

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

167

Effect of Fluid Maldistribution on the Performance of a Cross Flow Dry Cooling Tower  

International Nuclear Information System (INIS)

In all heat transfer and pressure drop analysis, it is assumed that the fluid is uniformly distributed. A serious reduction in dry cooling tower performance may result when the flow distribution is nonuniform. In this study, nonuniform flow distribution will be considered on both sided of the cooling tower, the reduction in heat transfer rates and consequently the increase of the energy losses will be derived for several flow arrangements. An analysis is presented to quantitatively evaluate the increase in pressure drop, energy losses and the degradation in heat transfer due to malflow distribution. the effect of maldistribution fluid on the rates of heat transfer of a dry cooling tower is experimentally determined. Experimental values of the heat transfer due to maldistribution are compared with the calculated one. It is shown that good agreements have been obtained. 7 figs

168

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

169

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

International Nuclear Information System (INIS)

This paper presents the results of an experimental investigation of the performance of a cooling tower with PVC packing. The following were examined; the effect of surface roughness, the effect of the angle of roughness and the effect of packing spacing. The investigation was divided into two parts: comparison of film heat transfer with air pressure drop, without water circulation and comparison of enthalpy change and pressure drop in the model cooling tower, with circulation of water. Seven commercial packing were investigated, covering a size range of 1.1< P/D<1.70 and 1?p/e?5 and a discussion of the dimensionless correlation resulting is given

170

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

171

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

172

Thermal Characteristics of Heating Towers  

Science.gov (United States)

Thermal characteristics of heating towers for air-source heat pumps are studied in terms of the overall enthalpy-transfer coefficient. Ka. First. the method of counter-flow calculation is presented taking physical properties of ethylene glycol solutions into account. Next, both cooling-tower and heating-tower experiments are carried out in a small, induced-draft. counterflow tower packed with tubes of a staggerd arrangement. using water and commercial ethylene glycol solutions. The coefficient Ka measured in the heating-tower experiment shows a trend similar to that in the cooling-tower experiment. So. the data on cooling towers will be helpful to the thermal design of heating towers.

Fujita, Toshihiko; Kametani, Shigeki

173

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

International Nuclear Information System (INIS)

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

174

In Situ g-PHA Measurements of the 285-3H Cooling Tower Components  

International Nuclear Information System (INIS)

The Analytical Development Section of Savannah River Technology Center was requested by the Facility Disposition Division to conduct in-situ gamma-ray pulse height analysis measurements to provide input toward the decision to unconditionally release the 285-3H cooling tower

175

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

176

VGB guideline for cooling tower construction planning; VGB-Richtlinie fuer die Planung von Kuehlturmanlagen  

Energy Technology Data Exchange (ETDEWEB)

As a publication complementing the VGB guideline `BTR Bautechnik bei Kuehltuermen`, (construction of cooling towers), this guideline is intended to enhance the knowledge of cooling tower technology in general. Specific operating conditions and requirements as well as technical facts are presented in a systematic overview elaborated in cooperation with manufacturers and operators. The information uses harmonized descriptions and terminology agreed upon by the cooperating parties, so as to achieve a standardized basis for comparative assessment of engineering and economic aspects of available cooling tower technology, and a form of `buyer`s guide` promoting competition and at the same time cooperation among the parties involved in cooling tower planning and construction. (orig./CB) [Deutsch] Im Zusammenhang mit der VGB-Richtlinie `BTR Bautechnik bei Kuehltuermen` stellt die vorliegende Richtlinie einen Beitrag zum erweiterten Verstaendnis der Kuehlturmtechnologie dar. Spezifische Betriebszustaende und -anforderungen sowie technische Fakten werden - im Einvernehmen von Herstellern und Betreibern - in abgestimmter Form beschrieben, um einheitliche technische, wirtschaftliche, wettbewerbsneutrale und wettbewerbsfoerdernde Voraussetzungen fuer vergleichbare Angebote zu erreichen und um die Zusammenarbeit zwischen den Beteiligten bei der Planung von Kuehlturmanlagen zu erleichtern. (orig./GL)

NONE

1997-12-31

177

Wind tunnel experiments on cooling tower plumes. Pt. 2  

International Nuclear Information System (INIS)

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

178

Operation practice and implications of circulating cooling water system of American nuclear power plants  

International Nuclear Information System (INIS)

In this paper, the circulating cooling water system of nuclear power plants (NPP) in United States is summarized, and the operation practices of different cooling water systems, such as once-through, natural and mechanical draft cooling tower, cooling pond, and mixed cooling mode, used by several coastal and inland NPPs are given. Also, based on the related experiences, some suggestions for use of cooling water system in China NPPs are presented. (authors)

179

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

180

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

International Nuclear Information System (INIS)

This contribution tries to present the various factors influencing the design of cooling tower pumps. As cooling tower pumps are very often designed as concrete speral casing pumps, the suction bend construction often offers itself. The running wheel of cooling tower pumps is usually of semi-axial design, whereby one has to differ between rigid, adjustable, and resetable running wheels. Finally, the type of cooling system and the nominal width are decisive for either the construction type of the spiral casing pump or the tubular type pump. Both methods are compared in a critical way. (orig.)

 
 
 
 
181

The influence of the finned-tube assembly on the dimensions of natural-draft dry-type cooling towers  

International Nuclear Information System (INIS)

For various heat exchanger systems the required heights of the towers are evaluated by means of a simplifying mathematical model for dimensioning cooling towers. The characteristics of the cooling systems are for each case taken from literature. The number of tube banks of the heat exchanger systems in flow direction was optimized using the operational data of the Schnehausen dry-type cooling tower. It may be assumed that by changing the tube configuration the performance of very closely spaced, aligned finned systems can be considerably improved. (GL)

182

Thermoelectrically cooled water trap  

Science.gov (United States)

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

Micheels, Ronald H. (Concord, MA)

2006-02-21

183

The maintenance and Repair of the Secondary Cooling Tower Operation of the HANARO for Ten years and Vibration Analysis of the Cooling Fan  

Energy Technology Data Exchange (ETDEWEB)

The HANARO is a multi-purpose reactor, 30MWth open-tank-in-pool type. Since the HANAO started the critical operation in 1995, it has been normally in operation at present. Heat generated by nuclear fission during the operation of the HANARO is absorbed by the primary coolant and is transmitted to the secondary coolant. The secondary coolant which passes through the cooling tower by means of the circulating pump is refrigerated by the heat exchanger with atmospheric air when the cooling fan operates. In order to operate the HANARO safely, it is essential for the cooling tower to have the sufficient cooling ability. Therefore, the records about maintenance and repair of the cooling tower were analyzed in detail to prevent the failure of the cooling tower in advance. Finally, the cooling tower of the HANARO has a good condition at present and the analysis in maintenance and repair of the cooling tower can be used as the operation data to have the cooling ability for the future.

Kim, Bong Soo; Park, Y. C.; Kim, Y. G.; Lee, Y. S

2006-02-15

184

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

185

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)

186

Modified technique of in-place fungicide treatment of cooling towers as used at the Paducah Gaseous Diffusion Plant  

International Nuclear Information System (INIS)

A modified technique of in-place fungicide treatment of cooling towers has been developed by Union Carbide Corporation, Paducah, Kentucky. The technique enables the fungicide user to treat towers safely without endangering the personnel applying the fungicide. The technique is time saving and effective in obtaining complete coverage of the plenum areas and the decking

187

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

188

Irreversibility Analysis of a Cross Flow Dry Cooling Tower due to Maldistribution of Fluids  

International Nuclear Information System (INIS)

Fluid flow distribution one of the most important variables affecting the performance of a heat exchanger. In this study, the effect of fluids maldistribution on the energy losses of a cross flow dry cooling tower is investigated. Energy losses due to heat transfer, mixing, and pressure losses are discussed. The results shows that, more energy are consumed and lost forever for nonuniform flow. A theoretical analysis is presented to quantitatively evaluate the increase in energy losses due to maldistribution. 9 figs

189

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.

190

Light water cooled reactor  

International Nuclear Information System (INIS)

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

191

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

192

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

International Nuclear Information System (INIS)

The paper attempts to give the influencing parameters determining the type of cooling pump to be constructed. As cooling pumps are often constructed as pumps with a spiral concrete housing, the suction bend construction appears to be the most suitable. The impeller of cooling tower pumps is usually semiaxial. The type of pump - pump with spiral housing or pump with tubular housing - is determined by the cooling process and the nominal bore of the pump. Of the control techniques known, rotor blade control and inlet vane control are suitable for cooling tower pumps. The two methods of control are critically compared. (orig.)

193

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

International Nuclear Information System (INIS)

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

194

Application of modern measuring and data processing instrumentation in the construction of cooling towers in the Mochovce nuclear power plant  

International Nuclear Information System (INIS)

The specifications are presented of the cooling tower and the calculation is described of the permissible geometric shape deviation. The polar method was used in laying out the cooling tower and the process was based on the local layout network. The least squares method was used in calculating and aligning the coordinates. Digital theodolites were used in measuring the profile. The instruments allowed automating the collection and processing of the measured data. (E.J.)

195

Investigation of flow characteristics of a single and two-adjacent natural draft dry cooling towers under cross wind condition  

Science.gov (United States)

Wind effect on natural draught cooling towers has a very complex physics. The fluid flow and temperature distribution around and in a single and two adjacent (tandem and side by side) dry-cooling towers under cross wind are studied numerically in the present work. Cross-wind can significantly reduce cooling efficiency of natural-draft dry-cooling towers, and the adjacent towers can affect the cooling efficiency of both. In this paper we will present a complex computational model involving more than 750,000 finite volume cells under precisely defined boundary condition. Since the flow is turbulent, the standard k-? turbulence model is used. The numerical results are used to estimate the heat transfer between radiators of the tower and air surrounding it. The numerical simulation explained the main reason for decline of the thermo-dynamical performance of dry-cooling tower under cross wind. In this paper, the incompressible fluid flow is simulated, and the flow is assumed steady and three-dimensional.

Mekanik, Abolghasem; Soleimani, Mohsen

2007-11-01

196

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

Energy Technology Data Exchange (ETDEWEB)

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

Peter A. Pryfogle

2005-09-01

197

Nuclear cooling tower submitted to shrinkage; behaviour under weight and wind  

International Nuclear Information System (INIS)

A numerical formulation to analyse nuclear cooling tower submitted to creep and shrinkage of concrete is presented in this paper. Both humidity effects and non-linear mechanical behaviour of the constitutive materials are taken into account. Moisture migration is described using a single diffusion equation in which the relative humidity is the driving force and delayed strains are obtained in a phenomenological way. To capture the time-dependent behaviour, an extension of a continuum plasticity model which incorporates viscous behaviour, has been developed and its main parameters are obtained from experimental results. The effects produced by internal stresses that result from time-dependent deformations are finally presented for nuclear tower under services loading

198

Predicted and observed cooling tower plume rise and visible plume length at the John E. Amos power plant  

International Nuclear Information System (INIS)

A one-dimensional numerical cloud growth model and several empirical models for plume rise and cloud growth are compared with twenty-seven sets of observations of cooling tower plumes from the 2900 MW John E. Amos fossil-fuel power plant in West Virginia. The three natural draft cooling towers are 200m apart. In a cross wind, the plumes begin to merge at a distance of about 500m downwind. In calm conditions, with reduced entrainment, the plumes often do not merge until heights of 1000m. The average plume rise, 750m, is predicted well by the models, but day-to-day variations are simulated with a correlation coefficient of about .5. Model predictions of visible plume length agree, on the average, with observations for visible plumes of short to moderate length (less than about 1km). The prediction of longer plumes is hampered by our lack of knowledge of plume spreading after the plumes level off. Cloud water concentrations predicted by the numerical model agree with those measured in natural cumulus clouds

199

Cooling clothing utilizing water evaporation  

DEFF Research Database (Denmark)

We developed cooling clothing that utilizes water evaporation to cool the human body and has a mechanism to control the cooling intensity. Clean water was supplied to the outer surface of the T-shirt of the cooling clothing, and a small fan was used to enhance evaporation on this outer surface. To prevent wet discomfort, the T-shirt was made of a polyester material having a water-repellent silicon coating on the inner surface. The chest, front upper arms, and nape of the neck were adopted as the cooling areas of the human body. We conducted human subject experiments in an office with air temperature ranging from 27.4 to 30.7 °C to establish a suitable water supply control method. A water supply control method that prevents water accumulation in the T-shirt and water dribbling was validated; this method is established based on the concept of the water evaporation capacity under the applied environment.

Sakoi, Tomonori; Tominaga, Naoto

2014-01-01

200

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

 
 
 
 
201

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

202

Synthesis of some novel sulfonamide derivatives and investigating their biocidal activity in cooling towers  

Energy Technology Data Exchange (ETDEWEB)

A novel series of dibenzothiophenedioxide sulphonamide derivatives were synthesized and tested as antimicrobial agents. The chemical structures of the prepared compounds were confirmed by micro elemental analysis, fourier transform infrared (FT-IR) and proton nuclear magnetic resonance spectroscopy (H-NMR). The surface parameters of two of the prepared compounds were determined at 35 C including, surface tension, effectiveness, maximum surface excess and minimum surface area. Also the standard free energy of micellization and adsorption were recorded. The results showed that the prepared sulphonamides have good surface properties and effective antimicrobial activity against thirty three test organisms isolated from cooling towers. (orig.)

Badawi, Abdelfattah M.; Mohamed, Dalia Emam; Hafiz, Amal A.; Amed, Sahar M. [Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt). Applied Surfactants Lab.; Gohar, Yousry M. [Alexandria Univ. (Egypt). Microbiology Div.; Soliman, El-Sayed Ahmed [Ain Shams Univ., Cairo (Egypt). Chemistry Dept.; Sanan, Mohamed S. [Alexandria National Refining and Petrochemical Co. (ANRPC), Alexandria (Egypt)

2011-03-15

203

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-09-01

204

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

205

Convection towers  

Science.gov (United States)

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

206

Cooling of feed water tubes  

International Nuclear Information System (INIS)

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

207

An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower  

Directory of Open Access Journals (Sweden)

Full Text Available A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90°, 60 °, 45°, and 30° are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90° has the worst performance while 45° and 30° has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60°, while the best performance occurred at 45° and 90° at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

Du Xueping

2014-01-01

208

Calculation of characteristics of convective outflow from cooling tower system of nuclear power installation using ADT 4300 computer  

International Nuclear Information System (INIS)

A program is described which resolves the shape and development of the plume forming above a system of cooling towers. It is used to study the thermal pollution of the atmosphere. The program is capable of carrying out routine calculations of the size of the plume and its other physical parameters from input characteristics of the system of towers and from ambient meteorological conditions. Diagrams of the individual parts of the program are given. (M.D.). 7 figs., 2 tabs., 6 refs

209

Cooling tower performance improvements for a cycling PC-fired unit  

International Nuclear Information System (INIS)

The inevitable deregulation of the electric utility industry has caused many electric utility companies to look closely at their existing assets and predict what role these units will play in the future. Reducing a unit's production cost is the best way to prepare for the deregulated market but this benefit often comes with an associated capital expenditure. Spending capital dollars today can pose a quandary for an investor-owned utility committed to maintaining low consumer rates. The dilemma is: How does a utility improve its competitiveness position today while ensuring that the shareholders are getting a fair return on their investment when any fuel savings are passed through to the consumer? Illinois Power (IP) has been aggressively looking to improve their current competitive position while facing the current regulatory challenges. Studies have been commissioned to identify the most attractive cost reduction opportunities available. One study identified that improving the performance of the Unit 6 cooling tower at the Havana Station would be a very economically attractive option. This paper addresses the economics of refurbishing a cooling tower for a cycling pulverized-coal (PC) unit to provide a competitive advantage leading into the deregulated electricity market

210

18 CFR 420.44 - Cooling water.  

Science.gov (United States)

... 2010-04-01 2010-04-01 false Cooling water. 420.44 Section 420.44 Conservation...CHARGES Charges; Exemptions § 420.44 Cooling water. Water used exclusively for cooling purposes which is returned to the...

2010-04-01

211

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

212

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

213

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

Energy Technology Data Exchange (ETDEWEB)

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

Ken Mortensen

2011-12-31

214

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

215

Increase in the turbulent diffusion of pollutants by cooling tower plumes  

International Nuclear Information System (INIS)

Measurements in the vicinity of wet natural-draught cooling towers of large output, carried out with the help of a power glider, show that the atmospheric turbulence can increase drastically within the range of influence of the plumes. If the flue gases from a stack reach this region of increased turbulence they are more rapidly diluted; this can result in appreciable changes in the ground concentration of the precipitated pollutants. Impairment is then greater in the immediate vicinity of the power plant and lower in more remote areas. To enable allowance to be made for this influence when estimating the effects on the environment averaged over a year, the extent to which the plume increases vertical diffusion was investigated. (Auth.)

216

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-01-15

217

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

218

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

219

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

2013-07-15

220

Condenser cooling water quality at Kaiga  

International Nuclear Information System (INIS)

Once-through circulation of river water is envisaged in Kaiga for cooling the condenser and other related equipment. Water drawn from Kali river will be used for this purpose. After cooling the condenser, the water is let into the river through the outfall system. The materials used in the cooling water system consist mainly of SS 316 and carbon steel. Chlorination is the treatment proposed to the cooling water. The cooling water quality is found to be satisfactory. (author). 2 refs

 
 
 
 
221

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)

222

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.

223

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-09-01

224

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 on of important components of the cooling tower. (authors)

225

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.)

226

Effect of water treatment on the comparative costs of evaporative and dry cooled power plants  

Energy Technology Data Exchange (ETDEWEB)

The report presents the results of a study on the relative cost of energy from a nominal 1000 Mwe nuclear steam electric generating plant using either dry or evaporative cooling at four sites in the United States: Rochester, New York; Sheridan, Wyoming; Gallup, New Mexico and Dallas, Texas. Previous studies have shown that because of lower efficiencies the total annual evaluated costs for dry cooling systems exceeds the total annual evaluated costs of evaporative cooling systems, not including the cost of water. The cost of water comprises the cost of supplying the makeup water, the cost of treatment of the makeup and/or the circulating water in the tower, and the cost of treatment and disposal of the blowdown in an environmentally acceptable manner. The purpose of the study is to show the effect of water costs on the comparative costs of dry and evaporative cooled towers.

Gold, H.; Goldstein, D.J.; Yung, D.

1976-07-01

227

A multi-layered model for collapse analysis of large reinforced concrete natural-draft cooling towers  

International Nuclear Information System (INIS)

The modelling of the material behavior of the reinforced concrete is managed by utilizing Bazant's plastic-fracturing theory for the concrete and an elasto-plastic material law, including the Bauschinger effect, for the rebar. The theoretical basis of the model is the shear deformation theory as well as the Kirchhoff-Love theory in the sense of Donnell-Marguerre's approach. To consider the discontinuity of strains in the case of the cracked concrete, mixed FE-models that are based on Hellinger-Reissner's variational principle and its modified version are developed. At last, the damage evolution of a large natural draught cooling tower until collapse is traced numerically. The collapse analysis was performed under dead load and quasi-static wind action. The collapse simulation demonstrates the weakening of the cooling tower under the load combinations according to Euro-code and BTR taking the variability of the material properties into account. (orig./HP)

228

Recent amendments to the VGB Guideline on the design and construction of cooling towers in power plants  

Energy Technology Data Exchange (ETDEWEB)

In view of the coming introduction of the European Directives, it was necessary to revise the VGB Guideline on the structural design, computation and execution of cooling towers. The new edition includes the experience of plant and structural design engineers, construction companies, experts for checking and approvals, scientists and operators, and presents the state of the art. Besides, the current developments in concrete technology, the VGB Guideline contains for the first time information about the application of concrete highly resistant against acid attack, which allows dispensing with coating on the inside of the cooling tower shell. Especially the update of specifications concerning wind and temperature as well as safety concept is another issue of the current revision. (orig.)

Niemann, Hans-Juergen [Ingenieurgesellschaft Niemann and Partner, Bochum (Germany); Harte, Reinhard [Bergische Univ. Wuppertal (Germany). Dept. of Civil Engineering; Meyer, Joachim [ZERNA INGENIEURE GmbH, Bochum (Germany). Dept. Engineering of Power Plants and Industrial Buildings; Woermann, Ralf [Kraetzig and Partner Ingenieurgesellschaft fuer Bautechnik mbH, Managing Partner, Bochum (Germany)

2011-07-01

229

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

230

Cooling water practices at coal and gas based power stations  

International Nuclear Information System (INIS)

Water is used for a number of diverse purposes in a power plant. In most cases, the water cannot be used as such and requires treatment to ensure higher efficiency and protection of equipment. Corrosion, scale deposition and fouling have since long posed as challenges to the technical expertise of cooling water chemists at industrial and utility power plants. The study of the raw water, water samples from the CW tower basin and clarified water of various coal and gas based power stations has indicated that problem of corrosion and scale formation are linked with the quality of raw water and operating parameters. The present paper deals with the different cooling water treatment practices being followed at various power stations and which have been quite helpful in improving the quality of water and reduce scale promotion, thereby improving heat transfer of condenser and heat exchangers, and in addition to prevent corrosion in the pipelines, water boxes, tube plates and condenser tubes. The above said studies constitutes a part of the Research work being carried out by corrosion group of Research and Development Centre, NTPC under the project entitled evaluation of standards for cooling water treatment which has been sanctioned under CBIP (Central Board of Irrigation and Power) action plan by Department of Power to Research and Development Centre of NTPC in the 8th plan period. (author)

231

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-08-01

232

Biofouling Control in Cooling Water  

Directory of Open Access Journals (Sweden)

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

T. Reg Bott

2009-01-01

233

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

International Nuclear Information System (INIS)

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

234

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

International Nuclear Information System (INIS)

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

235

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

International Nuclear Information System (INIS)

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

236

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 t 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 a

237

Molecular characterization and corrosion behavior of thermophilic (55 C) SRB Desulfotomaculum kuznetsovii isolated from cooling tower in petroleum refinery  

Energy Technology Data Exchange (ETDEWEB)

Desulfotomaculum kuznetsovii (D. Kuznetsovii), a thermophilic sulfate-reducing bacterium (SRB), was identified in a cooling tower of a petroleum refinery by 16S rRNA gene sequencing and its functional gene encoding dissimilatory sulfite reductase (dsrAB). The thermophilic sulfate-reducing bacterial species have been reported for the first time in the cooling towers of an Indian petroleum refinery. The protein coded by dsrAB gene was cloned, expressed, and identified using recombinant DNA technology. Weight loss method, electrochemical and surface analysis showed the corrosion behavior of the isolate. In the presence of D. kuznetsovii, the corrosion rate was higher when compared to control at 55 C. It suppresses the anodic reaction and enhances the cathodic reaction by the production of organic complex and iron sulfide, respectively. Numerous pitting were noticed on mild steel which is due to the presence of D. kuznetsovii and its role in the corrosion process has been discussed. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Anandkumar, B. [Department of Biotechnology, Sourashtra College, Madurai (India); Choi, J.H. [Electrokinetics Division, Korea ElectroTechnology Research Institute, Changwon (Korea); Venkatachari, G.; Maruthamuthu, S. [Corrosion Protection Division, Central Electro Chemical Research Institute (CECRI), Karaikudi (India)

2009-09-15

238

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-01-01

239

Water Cooled FBNR Nuclear Reactor  

International Nuclear Information System (INIS)

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

240

Physico-chemical interactions between radioactive effluents from a nuclear power station stack and plumes from a cooling tower: effects on ground deposition of radioactivity  

International Nuclear Information System (INIS)

A broad outline of numerical modelling of the interaction between radioactive effluents and plumes from cooling towers will be given and some of the more important aspects dealt with in some detail. The discussion will include the influence of wind direction, the heights reached by the cooling tower plumes, their visible lengths, which in turn depend on prevailing atmospheric conditions (humidity and wind speed), and the influence of natural rain and artificial precipitation (due to vapour droplets from the cooling towers) on the rate of radioactive deposition (fallout and washout). The probable effects of this interaction on the annual radioactive deposition factors will be brought out with the help of results obtained by numerical modelling (the KUMULUS model) for certain atmospheric conditions. The results obtained will be compared with those presented by other authors

 
 
 
 
241

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

Energy Technology Data Exchange (ETDEWEB)

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

NONE

1997-11-01

242

Water cooled FBNR nuclear reactor  

International Nuclear Information System (INIS)

y (www.sefidvash.net/fbnr). The simplicity in design and the world wide existence of water reactor technology, makes it a near term project compared to other future reactors. Small reactors are most adequate for both the developing and developed countries. They require low capital investment, and can be deployed gradually as energy demand calls for. The generation of energy at the local of consumption avoids high cost of energy transmission. The paradigm of economy of scale does not apply to the FBNR as it is a small reactor by its nature. The FBNR enjoys the economy of mass production. FBNR can serve a dual purpose plant generating electricity and producing desalinated water at the same time at lower cost. The FBNR has been evaluated by the IAEA's INPRO Methodology from the safety and nonproliferation points of view and is shown to be a fool proof reactor against nuclear proliferation and have inherent safety against any conceivable accident. The reactor has in its upper part the reactor core and a steam generator and in its lower part the fuel chamber. The core consists of two concentric perforated zircaloy tubes of 31 cm and 171 cm in diameters, inside which, during the reactor operation, the spherical fuel elements are held together by the coolant flow in a fixed bed configuration, forming a suspended fixed core. The coolant flows vertically up into the inner perforated tube and then, passing horizontally through the fuel elements and the outer perforated tube, enters the outer shell where it flows up vertically to the steam generator. The reserve fuel chamber is a 60 cm diameter tube made of high neutron absorbing alloy, which is directly connected underneath the core tube. The fuel chamber consists of a helical 40 cm diameter tube flanged to the reserve fuel chamber that is sealed by the national and international authorities. A grid is provided at the lower part of the tube to hold the fuel elements within it. A steam generator of the shell-and-tube type is integrated in the upper part of the module. A control rod can slide inside the centre of the core for fine reactivity adjustments. The reactor is provided with a pressurizer system to keep the coolant at a constant pressure. The pump circulates the coolant inside the reactor moving it up through the fuel chamber, the core, and the steam generator. Thereafter, the coolant flows back down to the pump through the concentric annular passage. At a flow velocity called terminal velocity, the water coolant carries the 15 mm diameter spherical fuel elements from the fuel chamber up into the core. A fixed suspended core is formed in the reactor. In the shut down condition, the suspended core breaks down and the fuel elements leave the core and fall back into the fuel chamber by the force of gravity. The fuel elements are made of UO2 micro spheres embedded in zirconium and cladded by zircaloy. Any signal from any of the detectors, due to any initiating event, will cut-off power to the pump, causing the fuel elements to leave the core and fall back into the fuel chamber, where they remain in a highly subcritical and passively cooled conditions. The fuel chamber is cooled by natural convection transferring heat to the water in the tank housing the fuel chamber. The nest step in the development of FBNR is the construction of its prototype. Efforts are being made to secure participants in such an endeavor. (author)

243

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-09-01

244

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

245

Passive cooling means for water cooled nuclear reactor plants  

International Nuclear Information System (INIS)

This patent describes a water cooled, nuclear fission reactor plant having an improved auxiliary passive cooling system for dissipating heat produced during periods of other than normal operation, the nuclear fission reactor plant. It comprises the combination of: a reactor pressure vessel containing a core of heat producing fissionable fuel material provided with reciprocally removable fission control rods and having external steam and hot coolant water conduits extending out therefrom including a circulation loop passing through a heat exchanger comprising a steam driven turbine, the reactor pressure vessel and adjacent components being housed within an enclosing, substantially gas impermeable containment structure for retaining a gaseous atmosphere enveloping the reactor pressure vessel and adjacent components; a container retaining a pool of cooling water isolated from the atmosphere of the containment structure and positioned at a level within the containment structure above the reactor pressure vessel, the isolation container including a heat exchanger unit submerged in the retained pool of cooling water having an inlet which is in optional fluid communication with the interior of the reactor pressure vessel and with the atmosphere of the containment structure enveloping the pressure vessel; a suppression pool chamber containing a pool of cooling water for condensing steam positioned adjacent to the reactor pressure vessel and having a horizontal vent passing toel and having a horizontal vent passing to an adjoining area which is in open communication to the atmosphere of the containment structure; a vent duct extending from an outlet of the heat exchanger unit submerged in the isolation container pool downward into the suppression pool chamber with its open end terminating below the surface of the cooling water pool and above the level of the horizontal vent passing an adjoining area

246

An important mechanism sustaining the atmospheric "water tower" over the Tibetan Plateau  

Directory of Open Access Journals (Sweden)

Full Text Available The Tibetan Plateau (TP, referred to as the "roof of the world" is also known as the "world water tower", because it contains a large amount of water resources and ceaselessly transports these waters to its surrounding areas. However, it is not clear how these waters are being supplied and replenished. In particular, how plausible hydrological cycles can be realized between tropical oceans and the TP. In order to explore the mechanism sustaining the atmospheric "water tower" over the TP, the relationship of a "heat source column" over the plateau and moist flows in the Asian summer monsoon circulation is investigated, here we show that the plateau's thermal structure leads to dynamic processes with an integration of two couples of lower convergences and upper divergences, respectively, over the plateau's southern slopes and main platform, which relay moist air in two ladders up to the plateau. Similarly to the CISK (Conditional Instability of the Second Kind mechanism of tropical cyclones, the elevated warm-moist air, in turn, forces convective weather systems, hence building a water cycle over the plateau. An integration of mechanical and thermal TP-forcing is revealed in relation to the Asian summer monsoon circulation knitting a close tie of vapor transport from tropical oceans to the atmospheric "water tower" over the TP.

X. Xu

2014-07-01

247

An important mechanism sustaining the atmospheric "water tower" over the Tibetan Plateau  

Science.gov (United States)

The Tibetan Plateau (TP), referred to as the "roof of the world", is also known as the "world water tower" because it contains a large amount of water resources and ceaselessly transports these waters to its surrounding areas. However, it is not clear how these waters are being supplied and replenished. In particular, how plausible hydrological cycles can be realized between tropical oceans and the TP. In order to explore the mechanism sustaining the atmospheric "water tower" over the TP, the relationship of a "heat source column" over the plateau and moist flows in the Asian summer monsoon circulation is investigated. Here we show that the plateau's thermal structure leads to dynamic processes with an integration of two couplings of lower convergence zones and upper divergences, respectively, over the plateau's southern slopes and main platform, which relay moist air in two ladders up to the plateau. Similarly to the CISK (conditional instability of the second kind) mechanism of tropical cyclones, the elevated warm-moist air, in turn, forces convective weather systems, hence building a water cycle over the plateau. An integration of mechanical and thermal TP forcing is revealed in relation to the Asian summer monsoon circulation knitting a close tie of vapor transport from tropical oceans to the atmospheric "water tower" over the TP.

Xu, X.; Zhao, T.; Lu, C.; Guo, Y.; Chen, B.; Liu, R.; Li, Y.; Shi, X.

2014-10-01

248

An important mechanism sustaining the atmospheric "water tower" over the Tibetan Plateau  

Science.gov (United States)

The Tibetan Plateau (TP), referred to as the "roof of the world" is also known as the "world water tower", because it contains a large amount of water resources and ceaselessly transports these waters to its surrounding areas. However, it is not clear how these waters are being supplied and replenished. In particular, how plausible hydrological cycles can be realized between tropical oceans and the TP. In order to explore the mechanism sustaining the atmospheric "water tower" over the TP, the relationship of a "heat source column" over the plateau and moist flows in the Asian summer monsoon circulation is investigated, here we show that the plateau's thermal structure leads to dynamic processes with an integration of two couples of lower convergences and upper divergences, respectively, over the plateau's southern slopes and main platform, which relay moist air in two ladders up to the plateau. Similarly to the CISK (Conditional Instability of the Second Kind) mechanism of tropical cyclones, the elevated warm-moist air, in turn, forces convective weather systems, hence building a water cycle over the plateau. An integration of mechanical and thermal TP-forcing is revealed in relation to the Asian summer monsoon circulation knitting a close tie of vapor transport from tropical oceans to the atmospheric "water tower" over the TP.

Xu, X.; Zhao, T.; Lu, C.; Guo, Y.; Chen, B.; Liu, R.; Li, Y.; Shi, X.

2014-07-01

249

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

250

"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

251

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

252

Biofouling reduction in recirculating cooling systems through biofiltration of process water.  

Science.gov (United States)

Biofouling is a serious problem in industrial recirculating cooling systems. It damages equipment, through biocorrosion, and causes clogging and increased energy consumption, through decreased heat transfer. In this research a fixed-bed biofilter was developed which removed assimilable organic carbon (AOC) from process water, thus limiting the major substrate for the growth of biofouling. The biofilter was tested in a laboratory model recirculating cooling water system, including a heat exchanger and a cooling tower. A second identical model system without a biofilter served as a reference. Both installations were challenged with organic carbon (sucrose and yeast extract) to provoke biofouling. The biofilter improved the quality of the recirculating cooling water by reducing the AOC content, the ATP concentration, bacterial numbers (30-40 fold) and the turbidity (OD660). The process of biofouling in the heat exchangers, the process water pipelines and the cooling towers, was monitored by protein increase, heat transfer resistance, and chlorine demanded for maintenance. This revealed that biofouling was lower in the system with the biofilter compared to the reference installation. It was concluded that AOC removal through biofiltration provides an attractive, environmental-friendly means to reduce biofouling in industrial cooling systems. PMID:12688686

Meesters, K P H; Van Groenestijn, J W; Gerritse, J

2003-02-01

253

Thermal calculations for water cooled research reactors  

International Nuclear Information System (INIS)

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

254

Importance of biological monitoring of cooling waters  

International Nuclear Information System (INIS)

In 2007, technical recommendation 'Biological monitoring of cooling waters I-F-23' was issued in the Czech Republic, which is addressed namely to operators and attending personnel of water cooling systems and similar equipment. The attention is paid to the biological problems and to the specification of biological methods (introduction into the subject matter, picked indicators, practice of determination and evaluation respectively, follow-up outline). Further are mentioned the characteristics of water-cooling facilities with the intent to inform likewise the biology specialists, which may face the aforesaid topic. (author)

255

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

256

Modeling of flows in heat exchangers with distributed load loss. Simulation of wet-type cooling tower operation with the two-dimensional calculation code ETHER  

International Nuclear Information System (INIS)

The principle of a cooling tower is first presented. The equations of the problem are given; the modeling of load losses and heat transfer is described. Then, the numerical method based on a finite difference discrete method is described. Finally, the different results of the calculations carried out in the case of an industrial operation are presented

257

VGB Guideline on the use of wood in cooling tower construction; VGB-Richtlinie fuer den Einsatz von Holz im Kuehlturmbau  

Energy Technology Data Exchange (ETDEWEB)

The use of wood for the construction of cooling towers and/or their installations is justified not only by its economic efficiency but also by the various favourable material properties it has to offer. These include high strength per unit of weight and excellent resistance against the various chemicals used in cooling tower construction. If appropriately constructed and impregnated with chemical protectants wooden cooling towers can last more than 25 years. The intent of the present guideline is to give planners, constructors, and operators a practice-oriented overview of the state of the art of wood cooling tower construction. [Deutsch] Die Verwendung von Holz im Kuehlturmbau fuer Konstruktions- oder/und Einbauelemente beruht neben den wirtschaftlichen Gesichtspunkten auf dem Zusammentreffen mehrerer positiver Eigenschaften, wie z.B. hohe Festigkeit bei geringerem Gewicht und erheblicher Widerstand gegenueber den im Kuehlturmbau vorkommenden Chemikalien. Durch geeignete bauliche Massnahmen und chemischen Schutz (Impraegnierung) kann eine Standzeit von Holzkuehltuermen von ueber 25 Jahren erreicht werden. Ein Anliegen war es, mit dieser Richtlinie fuer Planer, Hersteller und Betreiber einen praxisorientierten Ueberblick entsprechend dem Stand der Technik zu vermitteln. (orig./GL)

NONE

1996-12-31

258

River and cooling water temperature fluctuations  

International Nuclear Information System (INIS)

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

259

Wind towers architecture, climate and sustainability  

CERN Document Server

This unique volume provides the only holistic treatment of wind towers, a core aspect of sustainable architecture in hot, arid climates. The authors explain how traditional incarnations of these structures provide significant decreases in energy consumption through their use of renewable wind resources to cool buildings and water storage facilities. Beginning with the underlying scientific principles, the design and operation of wind towers is explained in depth and suggestions for optimization are provided, supported by the authors' findings from recent analytical studies.

Bahadori, Mehdi N; Sayigh, Ali

2014-01-01

260

COMPUTER ANIMATION OF A HISTORICAL BUILDING THROUGH TIME IN THE CASE OF WATER TOWER IN MARIBOR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this diploma thesis is to present computer modeling and computer animation as a way of transferring and delivering historical facts to the general public. Upon analyzing techniques of gathering data, ways of modeling, computer animating and already existing 3D models of historical building we created a new model of the Water tower in Maribor. All of our work is based on historical facts gathered thru museums, archives and libraries. The main goal of this thesis is a documentary...

Kodric?, Nina

2013-01-01

 
 
 
 
261

Air and water cooled modulator  

Science.gov (United States)

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

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

1995-01-01

262

From chip to cooling tower data center modeling: Part II Influence of chip temperature control philosophy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The chiller cooled data center environment consists of many interlinked elements that are usually treated as individual components. This chain of components and their influences on each other must be considered in determining the benefits of any data center design and operational strategies seeking to improve efficiency, such as temperature control fan algorithms. Using the models developed in part I of this work, this paper extends the analysis to include the electronics within the rack thro...

Walsh, Ej; Breen, Tj; Punch, J.; Shah, Aj; Bash, Ce

2010-01-01

263

Effect of cold inflow on chimney height of natural draft cooling towers  

International Nuclear Information System (INIS)

Highlights: ? Natural convection data were obtained from an air-cooled heat exchanger model. ? The extent of cold inflow was quantified to relate to the decrease in effective chimney height. ? Installation of wire mesh screen on chimney outlet blocked off cold inflow to improve the chimney efficiency. ? Evidence of existence of effective plume-chimney for when cold inflow was blocked off warrants further work. - Abstract: Temperature and pressure drop data obtained from an air-cooled heat exchanger model with cross-sectional flow areas of 0.56 m2, 1.00 m2 and 2.25 m2 operating under natural convection are presented that indicate significant cold inflow, resulting in the reduction of effective chimney height. Cold inflows encountered in actual applications where the Froude number is typically 0.2, may not be as severe as described in this paper, which was of the order of 10?6–10?4. Additional tests on smaller scale models appeared to favor the explanation that the occurrence of cold inflow in the air-cooled heat exchanger model was primarily due to the relative ease in either drawing cold air from inlet or from outlet, and to a lesser extent the Froude number of the chimney or the critical velocity estimated by formula. A CFD study will bring much understanding of the phenomenon for the different situations.

264

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

265

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

International Nuclear Information System (INIS)

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

266

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

267

Cooling water cleaning for steam turbine condensers  

International Nuclear Information System (INIS)

The design of filters for cooling water cleaning for steam turbine condensers are described. It is pointed out that mounting of additional filters before the condensers particularly in case of contaminated water and crag development in the circulation system is economically justified. Additional filters are mounted in combination with the system of ball cleaning of condenser tubes as well as independently of it

268

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

269

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...

Amir-Samimi

2013-01-01

270

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

271

European supercritical water cooled reactor  

International Nuclear Information System (INIS)

ency 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.

272

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

273

APPLICATION OF QUALITY FUNCTION DEPLOYMENT METHOD AND FUZZY LOGIC FOR IMPROVING THE DESIGN CHARACTERISTICS IN FRP COOLING TOWER-CASE STUDY  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Quality Function Deployment is a continuous improvement technique applied in the design of an FRP cooling tower.QFD helps to develop customer oriented, higher quality products. In order to improve the quality characteristics of this product and to satisfy the customers, the technique such as QFD followed by fuzzy logic technique approach is done. Though, the QFD method has some draw backs, it is one of the most important methods to interpret customer needs for specific quality development. To...

Mohan Kumar, G.; Umesh Sundar, R.

2012-01-01

274

A Cool Glass of Water  

Science.gov (United States)

Does an ice cube melt more quickly in salt water or in freshwater? The answer surprises the group of student science teachers portrayed in this case study. To explain the phenomenon they must figure out the interactions between two clusters of concepts: (1) density and its relationship to floating or sinking, and (2) three modes of heat or energy transfer due to a temperature difference (particularly conduction and convection, with an optional discussion of radiation). The case can be adapted for use in general education science courses or for introductory physics or chemistry courses.

Yang, Li-Hsuan

2007-01-01

275

Organohalogen products from chlorination of cooling water at nuclear power stations  

Energy Technology Data Exchange (ETDEWEB)

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

Bean, R.M.

1983-10-01

276

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

International Nuclear Information System (INIS)

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

277

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. 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

278

Subchannel analysis of supercritical water cooled reactors  

Energy Technology Data Exchange (ETDEWEB)

Subchannel analysis of supercritical water cooled reactors is carried out for estimating hot channel factors. A subchannel code for supercritical-water cooled reactors is developed. It is verified by comparing the calculated result of ASFRE-III code. The outlet coolant and cladding temperature are sensitive to the local power peaking and the assembly flow maldistribution because of the large coolant density change and high sensitivity of coolant temperature to the enthalpy change above the pseudo-critical temperature. However, it is shown that the effect is mitigated when the area of the peripheral subchannels is reduced and the mixing is enhanced 4-8 times of ordinary value at the grid spacers. The hot channel factor of a high temperature supercritical pressure light water cooled fast reactor (SCFR-H) is calculated using the uncertainties of Clinch River Breeder Reactor Plant (CRBRP). The factor is slightly higher than that of CRBRP because of the characteristics of supercritical water. The sensitivities of the hot channel factor is decreased for the SCFR-H fuel assembly in the core with blankets cooled by descending flow because of the higher inlet temperature of the driver fuel assemblies. (author)

Mukohara, Tami; Koshizuka, Seiichi; Oka, Yoshiaki [Nuclear Engineering Research Laboratory, University of Tokyo, Tokai, Ibaraki (Japan)

2000-07-01

279

Subchannel analysis of supercritical water cooled reactors  

International Nuclear Information System (INIS)

Subchannel analysis of supercritical water cooled reactors is carried out for estimating hot channel factors. A subchannel code for supercritical-water cooled reactors is developed. It is verified by comparing the calculated result of ASFRE-III code. The outlet coolant and cladding temperature are sensitive to the local power peaking and the assembly flow maldistribution because of the large coolant density change and high sensitivity of coolant temperature to the enthalpy change above the pseudo-critical temperature. However, it is shown that the effect is mitigated when the area of the peripheral subchannels is reduced and the mixing is enhanced 4-8 times of ordinary value at the grid spacers. The hot channel factor of a high temperature supercritical pressure light water cooled fast reactor (SCFR-H) is calculated using the uncertainties of Clinch River Breeder Reactor Plant (CRBRP). The factor is slightly higher than that of CRBRP because of the characteristics of supercritical water. The sensitivities of the hot channel factor is decreased for the SCFR-H fuel assembly in the core with blankets cooled by descending flow because of the higher inlet temperature of the driver fuel assemblies. (author)

280

The DA?NE water cooling system  

International Nuclear Information System (INIS)

a water cooling system for the DA?NE complex has been constructed and operated successfully. Special care has been taken to improve system reliability and temperature accuracy during the design, the realization and the commissioning; specific solutions have been adopted to meet accelerator requirements. Here the design, specifications and results of performance tests are revised

 
 
 
 
281

40 CFR 401.14 - Cooling water intake structures.  

Science.gov (United States)

... § 401.14 Cooling water intake structures. ...and capacity of cooling water intake structures...adverse environmental impact, in accordance with...501(a) of the Federal Water Pollution Control Act, as...

2010-07-01

282

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

283

WATER TREATMENT IN OPEN RECIRCULATING COOLING SYSTEMS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Studies for the use of cleaner water treatment technology in open recirculation systems lead to thedevelopment of a treatment philosophy based on the search of an operation with ideal cycle of concentration. Inthis way, the material balance control in the cooling system may reach a concentration level which thecirculating water exhibit naturally and, at the same time, low iron corrosion tendency and low calcium carbonatescale formation. The treatment using corrosion and deposit formation inhi...

Pereira, Ce?sar Augusto; Corre?a, Sergio Machado

2012-01-01

284

MHD/gas turbine systems designed for low cooling water requirements  

International Nuclear Information System (INIS)

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

285

Instability of water cooled from above  

International Nuclear Information System (INIS)

The temperature field and convection currents induced in water by convection, evaporation and radiation cooling of its surface were studied. These phenomena occur naturally and continuously in any lake, pond, reservoir or a river but they remain usually unobserved. Mach--Zehnder interferograms taken from the side of a tank of water are here used to measure the temperature distribution and to study the convective currents induced by cooling from the surface. Experiments were performed with initially uniform and thermally-stratified layers of water. Both qualitative and quantitative results of preliminary nature for temperature distribution are presented. Interferograms vividly reveal mixing motions induced by instabilities arising in the surface layer. The onset of manifest convective behavior was determined by visual observations of interferograms

286

Evaluation of the suitabil[i]ty of Fischer-Tropsch gas-to-liquid (GTL) Primary Column Bottoms as process cooling water : analysis of microbial community dynamics, fouling, scaling and corrosion / Savia Susanna Slabbert  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water in South Africa is becoming limiting due to economic growth, social development and the country's water demand that exceed its water availability. Water conservation in the industry can be accomplished by the reuse of process water instead of direct treatment and discharge. By reusing a process effluent as cooling water in cooling towers, the water requirements of an industry, such as Sasol, will be lower and a zero effluent discharge scenario could be achieved. At Sas...

Slabbert, Savia Susanna

2007-01-01

287

Development of tower internals for heavy water upgrading based on distillation technique (Preprint No. CI-1)  

International Nuclear Information System (INIS)

The development of highly efficient tower internals suitable for distillation columns has been taken up in stages commencing from 100 mm dia to 1500 mm dia. Tower internals constitute the following: 1)tower packing, 2)liquid collector, 3)liquid distributor, and 4)top and bottom support rings. Their fabrication is described. (author). 3 figs

288

A supervisory control strategy for building cooling water systems for practical and real time applications  

International Nuclear Information System (INIS)

This paper presents a model based supervisory control strategy for online control of building central cooling water systems to enhance their energy efficiency. The supervisory control strategy seeks the minimum energy input to provide adequate cooling energy for buildings, taking into account the characteristics and interactions of central cooling water systems as well as the requirements and constraints of practical application. Simplified semi-physical chiller and cooling tower models are used to predict the system energy performance and environment quality as well as the system response to changes of control settings. A hybrid optimization technique, namely the PMES (performance map and exhaustive search) based method, is developed and utilized to seek optimal solutions to the optimization problem. The control performance and energy performance of this model based supervisory control strategy are evaluated on the central cooling water system of a high rise commercial office building by comparing with that of the model based supervisory control strategy using a genetic algorithm (GA) as the optimization tool, and the performance map based near optimal control strategy as well as other conventional control strategies for cooling water systems in terms of energy efficiency, control accuracy, computational cost etc. The results showed that this strategy is more energy efficient and computational cost effective than other methods for online practical applications for online practical application

289

Repair criteria and methods of repair for concrete structures of nuclear power plants - Particular application on natural draught cooling towers in belgium  

International Nuclear Information System (INIS)

A previous paper was presented at the OCDE Workshop held 22-23 March 2000 in Brussels explaining different aspects of the techniques used for 'Instrumentation and monitoring of natural draught cooling towers in Belgium'. These monitoring and preventive techniques are now applied in Belgium since already more then 10 years by Tractebel on the towers of the nuclear plants. These huge constructions have to sustain considerable physical, chemical and biological loads. As one can figure out, and as years go by, these inspections showed deterioration of which type, progress, quantity eventually led to the need of repairing these structures. The present paper goes over 4 main different sorts of defects (beam supports breaking, fast carbonation rate, concrete porosity, and a series of local deteriorations like insufficient concrete cover, cracking, gravel pockets, corroded reinforcement) encountered on 3 cooling towers situated in Belgium, and affecting the shell as well as the inner structures. The diagnosis, the choice of the appropriate repair techniques and products which will avoid having to face much higher costs in the future are explained. It also gives an illustration of the works carried on site and points out the uncommon and complex aspects the treatment of such a construction implies (planning, both horizontal and vertical curved shape, works at great height,...). (author)

290

Corrosion of copper by deionized cooling water  

International Nuclear Information System (INIS)

This paper reports on corrosive carry off of pure copper surfaces by the contact with deionized cooling water which is unavoidable in any accelerator setup. Confining ourselves in the wide field of corrosion to this fundamental process, we investigated the quantitative influence of the most important variables. It turned out that the corrosion rate can vary by about a factor 15 with the flow velocity of the coolant (0-4m/sec), by a factor 3 with its temperature (20-50 degrees C) and only by a factor 1.6 due to ?-radiation (1-900 Gy/h). The by far dominant influence however is the amount of oxygen and carbon dioxide in the cooling water. By this corrosion can be enhanced by a factor of 200 and more. The absolute carry off of copper is about 0.05 mm/year under bad conditions

291

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. Making this thesis began by gathering all the possible solutions together and di-vides into different groups depending on the solution. There were five different groups and five different solutions were selected for a c...

Kuusisto, Tuomas

2011-01-01

292

Feasibility of a district cooling system using natural cold water  

Energy Technology Data Exchange (ETDEWEB)

The findings of investigations into the use of natural cold water district cooling systems are outlined. Concepts involving the use of natural cold water for cooling commercial and residential buildings have been examined and found to be economically sound and technically feasible. Studies indicate that naturally occurring cold water sources exist in proximity to certain municipal areas that have large cooling demands. Savings in energy resources, long term cost benefits, and environmental safety are the most attractive features of natural cold water cooling.

Jitco, T

1977-12-01

293

Kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems  

International Nuclear Information System (INIS)

The results of applying a kinetic model to the chlorination data supplied by Commonwealth Edison on the once-through cooling system at the Quad Cities Nuclear Station provide a validation of the model. The two examples given demonstrate that the model may be applied to either once-through cooling systems or to cooling systems involving cooling towers

294

Reuso de efluentes em torres de resfriamento - estudo conceitual: Aeroporto Internacional do Rio de Janeiro - doi: 10.4025/actascitechnol.v32i3.865 Water reuse for cooling towers – conceptual study: Rio de Janeiro International Airport - doi: 10.4025/actascitechnol.v32i3.865  

Directory of Open Access Journals (Sweden)

Full Text Available O reuso de água é ferramenta valiosa na gestão da água, que promove a otimização da utilização do recurso desta, que reduz e, muitas vezes, até elimina os impactos no meio ambiente. Neste trabalho foi investigada a composição do efluente secundário da estação de tratamento de efluentes (ETE APOIO do Aeroporto Internacional do Rio de Janeiro, com o objetivo de propor o processo adequado à reutilização deste efluente como água de reposição nas torres de resfriamento desse Aeroporto. Com base nas análises de cátions, ânions, DBO e DQO, verificou-se o parâmetro SDT – Cl- como crítico para processamento do efluente. Foi proposta uma sequência para reutilização do efluente que continha o tratamento de osmose inversa, o custo do m3 produzido por essa sequência foi estimado em R$ 2,90 m-3.Water reuse is an important tool in water management; it is a concept that promotes optimization of the water resource, reducing and often even eliminating environmental impacts. In this work, the composition of a secondary effluent (from the effluent treatment station (ETE APOIO at Rio de Janeiro International Airport was analyzed, with the aim of determining an adequate process for the reutilization of this effluent as replacement cooling water. Chemical analyses such as cation and anion analysis, BOD and COD were performed. Based on these analyses, it was found that TDS – Cl- was the critical parameter for effluent processing. A treatment system was proposed for effluent reuse including reverse osmosis; the cost estimate per m3 produced by this system was R$ 2.90 m-3.

Bernardo José Farah Machado

2010-11-01

295

Kinetic model for predicting the concentrations of active halogens species in chlorinated saline cooling waters. Final report  

Energy Technology Data Exchange (ETDEWEB)

A kinetic model has been developed for describing the speciation of chlorine-produced oxidants in seawater as a function of time. The model is applicable under a broad variety of conditions, including all pH range, salinities, temperatures, ammonia concentrations, organic amine concentrations, and chlorine doses likely to be encountered during power plant cooling water chlorination. However, the effects of sunlight are not considered. The model can also be applied to freshwater and recirculating water systems with cooling towers. The results of the model agree with expectation, however, complete verification is not feasible at the present because analytical methods for some of the predicted species are lacking.

Haag, W.R.; Lietzke, M.H.

1981-08-01

296

Kinetic model for predicting the concentrations of active halogens species in chlorinated saline cooling waters. Final report  

International Nuclear Information System (INIS)

A kinetic model has been developed for describing the speciation of chlorine-produced oxidants in seawater as a function of time. The model is applicable under a broad variety of conditions, including all pH range, salinities, temperatures, ammonia concentrations, organic amine concentrations, and chlorine doses likely to be encountered during power plant cooling water chlorination. However, the effects of sunlight are not considered. The model can also be applied to freshwater and recirculating water systems with cooling towers. The results of the model agree with expectation, however, complete verification is not feasible at the present because analytical methods for some of the predicted species are lacking

297

Basic regulations and standards for and performance of measurements in wet cooling towers; Norm-Grundlagen und praktische Durchfuehrung von Leistungsmessungen an Nasskuehltuermen  

Energy Technology Data Exchange (ETDEWEB)

Performance measurement in wet cooling towers is a process well covered and specified by national standards, which meanwhile have been harmonized. The European standard recently eleaborated by the cooling tower manufacturing firms that are members of the VDMA association reflects the state of the art and presents a regulatory framework for applications that has been well tuned to conditions met in practice. Evaluation of measurements relies on a comparative analysis of measured data with the cooling characteristics supplied by the manufacturer, either in the form of a diagram, a computer program, or as tabulated information. (orig./CB) [Deutsch] Leistungsmessungen am Nasskuehlturm sind in laenderspezifischen Normen genau spezifiziert. Die Normen haben sich mittlerweile angeglichen. Die von dem im VDMA zusammengeschlossenen Kuehlturmfirmen erarbeitete Euronorm zu diesem Thema spiegelt den aktuellen Stand in einer praxisnahen Durchfuehrungsverordnung wieder. Die Bewertung der Messung erfolgt im Vergleich mit der vor Messbeginn bekannten Kuehlcharakteristik, die entweder als Diagramm, Rechenprogramm oder zumindest als Tabelle vom Lieferanten erstellt wurde. (orig./GL)

Tesche, W. [Balcke-Duerr GmbH, Ratingen (Germany). Geschaeftsbereich Nasskuehlung

1998-09-01

298

A non-water-cooled heat flux measurement system under concentrated solar radiation conditions  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a brief description of a direct heat flux measurement system to measure the concentrated solar power delivered by a heliostat field onto the flat aperture of solar central receiver prototypes. The main advantages of this device are the low measurement uncertainty and the non-requirement of water-cooling. This system has been designed, mounted and used successfully on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA). The concentrated solar power and the spatial heat flux distribution, onto the aperture of a volumetric receiver prototype under evaluation. have been determined by the above-mentioned system. (author)

Ballestrin, J. [Plataforma Solar de Almeria (Spain). Central Receiver Technology

2002-09-01

299

Cooling methods for power plants  

International Nuclear Information System (INIS)

There are some results of measurements carried out on the wet cooling tower 275 MWe at TE Sostanj and on the experimental cooling tower at Jozef Stefan Institute, as well. They are including: the measurements of the output air conditions, the measurements of the cross current of water film and vapour-air flowing through two plates, and the distribution of velocity in boundary layer measured by anemometer

300

Selected problems of cooling water in coke production  

Energy Technology Data Exchange (ETDEWEB)

Chemical compositions of water used for cooling coal gas in coking plants in Czechoslovakia are discussed. Composition of cooling water in the NHKG coking plant was determined once a month for one year. The following water properties were determined: pH value, electrolytic conductivity, content of insoluble compounds, residue left after evaporation of cooling water, content of carbonic acid ions, chloride ions, sulfate ions, calcium ions, magnesium ions, and content of oxygen. Evaluation methods are described. Investigation results are shown in 2 tables. Buildup in cooling systems was influenced by water leaks. Addition of corrosion inhibitors would be economic only after eliminating water leaks. 4 references.

Kaloc, M.; Roubicek, V.; Benatsky, M.; Rojak, A.; Dockal, P.; Trytko, O.

1985-02-01

 
 
 
 
301

The insitu lining of cooling water piping  

International Nuclear Information System (INIS)

The internal corrosion of cooling water piping as well as other industrial piping is becoming an increasing problem to system reliability. There are various alternatives being offered as solutions to the problem including water treatment, coatings, and piping replacement. The in-place lining of these pipes is becoming increasingly popular as a cost-effective method to control corrosion. A cured-in-place plastic composite system can be installed with minimal dismantling or excavation. This paper will examine case histories of the installations of this lining system in power plants at three (3) locations in the United States and one in France. It will also summarize testing that has been performed on the lining system and tests that are currently being performed

302

Actinide closed water cooled thorium breeder reactor  

International Nuclear Information System (INIS)

Neutronic performance of actinide closed, water cooled thorium breeder reactor has been studied in comparison with 233U closed thorium breeder. The fuel form commonly employed for these reactors is oxide and heavy water is used as coolant and moderator in this PWR type reactor. Recycling all of self-produced actinides makes the core performance worse than only 233U closed cycle. This is mainly due to the increased parasitic neutron absorption by 234U. It still seems possible to design actinide closed thorium breeders with homogeneous and simple core with large pin gap but the attainable burn-up is limited to about 30 GWd/t that is almost half value of 233U closed cycle. (authors)

303

Cooling water treatment program for trouble free continuos operation. Choki renzoku sogyo ni taioshita reikyaku shori ni tsuite  

Energy Technology Data Exchange (ETDEWEB)

The historical changes of cooling water treatment technology were summarized, and the problem and the method of solution in cooling water treatment for trouble free continuous operation were discussed. Once-through cooling systems with no cooling tower were prevailing in the 1950's. Anticorrosives of chromium system came into wide use in the 1960's. In the 1970's, scale prevention technology by synthetic polymer was established, and non-chromium treatment became effective as well. Low phosphorous, and non-sulfuric system cooling water treatment technologies came into wide use in the 1980's. In the 1990's, high functional synthetic polymer was developed, and overall cooling water treatment technology was established which had been used widely as the cooling treatment system to deal with long term operation. The concept of cooling water treatment from the build-up to the normal operation of the plant was explained. Countermeasures to prevent contamination and the control indexes were discussed. Improvement of anticorrosion effect and the improvement in the scale prevention effect were outlined. 6 refs., 13 figs., 1 tab.

Uchida, T. (Kurita Water Industries, Ltd., Tokyo (Japan))

1992-12-05

304

Electrochemistry of Water-Cooled Nuclear Reactors  

Energy Technology Data Exchange (ETDEWEB)

This project developed a comprehensive mathematical and simulation model for calculating thermal hydraulic, electrochemical, and corrosion parameters, viz. temperature, fluid flow velocity, pH, corrosion potential, hydrogen injection, oxygen contamination, stress corrosion cracking, crack growth rate, and other important quantities in the coolant circuits of water-cooled nuclear power plants, including both Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). The model is being used to assess the three major operational problems in Pressurized Water Reactors (PWR), which include mass transport, activity transport, and the axial offset anomaly, and provide a powerful tool for predicting the accumulation of SCC damage in BWR primary coolant circuits as a function of operating history. Another achievement of the project is the development of a simulation tool to serve both as a training tool for plant operators and as an engineering test-bed to evaluate new equipment and operating strategies (normal operation, cold shut down and others). The development and implementation of the model allows us to estimate the activity transport or "radiation fields" around the primary loop and the vessel, as a function of the operating parameters and the water chemistry.

Dgiby Macdonald; Mirna Urquidi-Macdonald; John Mahaffy, Amit Jain, Han Sang Kim, Vishisht Gupta; Jonathan Pitt

2006-08-08

305

Electrochemistry of Water-Cooled Nuclear Reactors  

International Nuclear Information System (INIS)

This project developed a comprehensive mathematical and simulation model for calculating thermal hydraulic, electrochemical, and corrosion parameters, viz. temperature, fluid flow velocity, pH, corrosion potential, hydrogen injection, oxygen contamination, stress corrosion cracking, crack growth rate, and other important quantities in the coolant circuits of water-cooled nuclear power plants, including both Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). The model is being used to assess the three major operational problems in Pressurized Water Reactors (PWR), which include mass transport, activity transport, and the axial offset anomaly, and provide a powerful tool for predicting the accumulation of SCC damage in BWR primary coolant circuits as a function of operating history. Another achievement of the project is the development of a simulation tool to serve both as a training tool for plant operators and as an engineering test-bed to evaluate new equipment and operating strategies (normal operation, cold shut down and others). The development and implementation of the model allows us to estimate the activity transport or ''radiation fields'' around the primary loop and the vessel, as a function of the operating parameters and the water chemistry

306

Caries selective ablation: effects of water cooling  

Science.gov (United States)

The aim of the study was to describe the effects of different surrounding media -- water and air -- during application of a caries selective laser system on healthy dentin, the substance which should be preserved. Fluences used in this study were chosen with respect to the previously described ablation thresholds of healthy dentin. Fiber optics (0 400 micrometers , N.A. 0, 12) were used for transmission of the laser radiation. Luminescence emission was recorded time resolved in order to differentiate between fluorescence and plasma emission. Hot plasma seems to be rigorously reduced if the irradiation is performed under water. Scanning electron microscopical investigations were performed. Craters irradiated in air show cracks and signs of melting whereas crater walls after irradiation under water demonstrated rough surfaces and open dentinal tubules. Cracks did not occur if irradiation was performed in water. As long as water cooling is provided a Q-switched, frequency-doubled Alexandrite-laser providing fluences of 5 Jcm-2 at the tooth surface does not produce hot plasma during the ablation of healthy dentin.

Hennig, Thomas; Rechmann, Peter; Abel, Martin

1994-12-01

307

Cooling-water amounts, temperature, and the environment  

International Nuclear Information System (INIS)

The release of heat from power plants into a water can take place with relative small quantities of cooling water, highly warmed up accordingly, or with large quantities of cooling water slightly warmed up. The utilization of cooling water is bound to certain guidelines established by the authorities. With the intention to protect the environment, the admissable temperatures and warming-up have been strictly limited by the authorities. In the Netherlands, we have presently temporary cooling water guidelines which allow a max. temperature of the cooling water in the cooling cycle of 300C and a maximum admissible temperature rise in the condenser between 70C during summer and 150C during winter. It has also been determined in these requirements how much cooling water at least has to be used to discharge a specified quantity of heat. Plankton, spawn and young fish are dragged with the cooling water. Harm to these organisms can be caused mechanically by pumps, sieves and the condenser or they can be harmed by the temperature rise in the condenser. Investigations showed that mechanical harm to spawn and young fish in the cooling water flow should not be ignored, and that detectable harm to plankton organisms takes place only at water temperatures above 320C. The cooling water consumption can therefore be optimised as follows: The solution of a greater temperature increase and a slightly higher value for the temperature maximum can reduce the cooling water quantity. This reduction of the cooling water quantity reduces the destruction of the fish quantity, which gets into the cooling water system, especially during the summer. If the temperature rise and the temperature itself are not selected too high, the destruction of fish may be reduced without causing serious damage to the plankton. (orig.)

308

Recycled Towers  

Science.gov (United States)

Students learn about material reuse by designing and building the strongest and tallest towers they can, using only recycled materials. They follow design constraints and build their towers to withstand earthquake and high wind simulations.

Integrated Teaching And Learning Program

309

New structural design standard for cooling towers. Pilot project BoA 2 and 3 in Neurath; Pilotprojekt der neuen Normengeneration im Kuehlturmbau. Die Naturzugkuehltuerme von BoA 2 and 3 in Neurath  

Energy Technology Data Exchange (ETDEWEB)

Starting in 2006 RWE Power is erecting two lignite power plants with highly optimized efficiency (BoA) in Neurath near Cologne. These will be the second and third plant of this most advanced technique after the completion of BoA1 in Niederaussem in 2003. The most outstanding buildings of the new power-station are the natural draught cooling towers with a height of 173 m. Their design and execution will be described in this paper. For the first time in cooling tower design the completely revised new edition 2005 of the VGB-Guideline ''Structural Design of Cooling Towers'' was applied in connection with other related new design standards. (orig.)

Woermann, Ralf [Kraetzig und Partner Ingenieurgesellschaft fuer Bautechnik mbH, Bochum (Germany); Haupt, Ralf [ALPINE BAU DEUTSCHLAND AG NL Industrie- und Kraftwerksbau, Dortmund (Germany); Ohlmann, Uwe [RWE Power AG, Essen (Germany). Bautechnik

2010-01-15

310

Fast reactor cooled by supercritical light water  

International Nuclear Information System (INIS)

This report introduces the result of a feasibility study of a fast reactor cooled by supercritical light water (SCFR) with once-through cooling system. It is characterized by (1) no need of steam separator, recirculation system, or steam generator, (2) 1/7 of core flow rate compared with BWR or PWR, (3) high temperature and high pressure permits small turbine and high efficiency exceeding 44%, (4) structure and operation of major components are already experienced by LWRs or thermal power plants. Modification such as reducing blanket fuels and increasing seed fuels are made to achieve highly economic utilization of Pu and high power (2 GWe). The following restrictions were satisfied. (1) Maximum linear heat rate 39 kW/m, (2) Maximum surface temperature of Inconel cladding 620degC, (3) Negative void reactivity coefficient, (4) Fast neutron irradiation rate at the inner surface of pressure vessel less than 2.0x1019 n/cm2. Thus the high power density of 167 MW/m3 including blanket is thought to contributes economy. The high conversion is attained to be 0.99 Pu fission residual rate by the outer radius of fuel rod of 0.88 mm. The breeding of 1.034 by Pu fission residual rate can be achieved by using briquette (tube-in-shell) type fuel structure. (K. Tsuchihashi)

311

MIC in Circulating Cooling Water System  

Directory of Open Access Journals (Sweden)

Full Text Available MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of microorganisms was introduced firstly. There are three kinds of microorganisms in the system, including bacteria, fungi and algae. Species of these microorganisms are shown in the paper. Then, mechanisms of MIC are analysed. Although there is no universal mechanism of MIC, MIC is still mainly an electrochemical corrosion in nature. Meanwhile, the mechanisms on SRB and iron bacteria are introduced in details. At last, several methods of microorganisms control are put forward in the paper.

Li Zhang

2012-04-01

312

Technological readiness of evolutionary water cooled reactors  

International Nuclear Information System (INIS)

Nuclear energy has evolved to a mature industry that supplies over 16% of the world's electricity, and it represents an important option for meeting the global energy demands of the coming century in an environmentally acceptable manner. New, evolutionary water cooled reactor designs that build on successful performance of predecessors have been developed; these designs have generally been guided by wishes to reduce cost, to improve availability and reliability, and to meet increasingly stringent safety objectives. These three aspects are important factors in what has been called technological readiness for an expanded deployment of nuclear power; a major increase in utilization of nuclear power will only occur if it is economically competitive, and meets safety expectations. To this end, the industry will also have to maintain or improve the public perception of nuclear power as a benign, economical and reliable energy source. (author)

313

Hydrodynamic analysis and calculation of metal temperature distribution in spiral water wall of ultra supercritical tower boiler  

Science.gov (United States)

In this paper, the spiral water wall system of a 1000MW ultra supercritical tower boiler is simplified as a network system, consisting of circuits, pressure grids and connecting tubes. The establishment of the mathematical model for calculating the mass flux distribution and metal temperature in water wall is based on the mass, momentum and energy conservation equations. The water wall flow distribution and temperature profile of the boiler were computed. The result shows that the differences of outlet temperature and mass flux are small in spiral tube water wall at BMCR, 75%BMCR load and 40%BMCR load. The metal temperatures are all in the allowable ranger.

Shen, Chengwu; Yang, Dong; Yao, Danhua; Zhu, Yufeng; Xu, Xueyuan

2013-07-01

314

The role of water in cooling ignimbrites  

Science.gov (United States)

A summary of observational literature on ignimbrites provides the basis for the development of a two-dimensional numerical model of ignimbrite cooling processes. Factors include emplacement conditions, post-emplacement processes, and the nature and timing of interactions with water during cooling. The model uses the multiphase finite element heat and mass transfer (FEHM) code, which has been enhanced to handle conditions up to 1500 °C. The instantaneous emplacement of a 750 °C ignimbrite with internal gas pressures of up to 0.5 MPa (lithostatic) has a great effect on the variably saturated substrate. A water table present within a few tens of meters of the base of the ignimbrite produces a region of high pressure and temperature that exists for about 20 years, driving vapor upward through the ignimbrite as diffuse flow and in gas escape structures and enhancing cooling at the base of the ignimbrite. Variations in initial gas pressure between atmospheric and lithostatic conditions have little effect on the thermal evolution. The results of the numerical modeling of 20- and 40-m-thick ignimbrites indicate that, even for moderate pore water saturations in the substrate, vaporization and resultant pressurization may exceed lithostatic confining pressures in the upper substrate and basal ignimbrite, and explosive pressure release may occur, resulting in the development of discrete fumarole conduits or phreatic explosions. The likelihood for explosive pressure release appears to be greater when the nominal ignimbrite thickness is on the order of the depth of a buried valley. The pressure buildup is enhanced by the geometry of the ignimbrite-substrate interface, especially at convex corners such as on the edges of a buried valley. The boiling zones at the top and bottom of a cooling ignimbrite involve the development of a heat-pipe, which provides an efficient means of transporting heat from the superheated tephra out tens of meters into the ambient environment. The predicted temporal evolution of temperature, pressure, and vapor flow in a 40-m ignimbrite support the conceptual model of degassing, welding and compaction, devitrification, and alteration occurring concomitantly in the first several years after emplacement and driven in part by production and migration of meteoric steam. This vapor flowing through the ignimbrite matrix at 5×10 -5 kg s -1 in the first 10 years enhances devitrification in any part of the ignimbrite above the base in nonwelded deposits. In the case where welding occurs, lower permeability limits the diffuse flow of gas upward through the ignimbrite from the region of boiling and pore pressurization at the base, and enhanced devitrification in the basal parts of the ignimbrite may occur where pore vapors circulate in abundance. Immediately above the welded zone, a devitrified horizon may develop where the upper boiling/condensation zone and perched meteoric infiltration results in enhanced saturations.

Keating, Gordon N.

2005-04-01

315

Operating manual for the Tower Shielding Facility  

International Nuclear Information System (INIS)

This manual provides information necessary to operate and perform maintenance on the reactor systems and all equipment or systems which can affect their operation or the safety of personnel at the Tower Shielding Facility. The first four chapters consist of introductory and descriptive material of benefit to personnel in training, the qualifications required for training, the responsibilities of the personnel in the organization, and the procedures for reviewing proposed experiments. Chapter 8, Emergency Procedures, is also a necessary part of the indoctrination of personnel. The procedures for operation of the Tower Shielding Reactor (TSR-II), its water cooling system, and the main tower hoists are outlined in Chapters 5, 6, and 7. The Technical Specification surveillance requirements for the TSR-II are summarized in Chapter 9. The maintenance and calibration schedule is spelled out in Chapter 10. The procedures for assembly and disassembly of the TSR-II are outlined in Chapter 11

316

Phone company switches to free cooling economy  

Energy Technology Data Exchange (ETDEWEB)

Spurred by New Jersey Bell's statewide campaign to reduce energy costs, the company's Camden complex installed a high-performance water heat exchanger to handle wintertime cooling needs. Using tower water to provide cooling to the chilled water loop, the system saved $35,000 during its first season on line.

1986-04-01

317

Ozonation of cooling water prevents biofilms and legionella. Hygiene; Kuehlwasserbehandlung mit Ozon haelt Biofilme und Legionellen in Schach. Hygiene  

Energy Technology Data Exchange (ETDEWEB)

Legionella in plumes of evaporation cooling towers have often caused serious illnesses and even deaths. To prevent the growth of microorganisms in cooling towers, operators often use hazardous and toxic biocides or chlorine. There is an ecologically and also technically efficient alternative: In the Briey plant of the international Norma group, biofilm and legionella prophylaxis is achieved by ozonation. (orig.)

Hackl, W.; Hoffmann, M. [BWT Wassertechnik GmbH, Schriesheim (Germany). Forschung und Entwicklung

2006-11-15

318

The meteorological measuring system of the Karlsruhe Nuclear Research Centre - evaluation of special measurements to determine the seasonal and daily distribution of long cooling tower plumes  

International Nuclear Information System (INIS)

The measuring system mainly serves to record the parameters which are relevant for the diffusion of off-gas plumes and it comprises a total of 47 instruments allowing to measure the wind velocity, wind direction, wind vector, temperature, dew point, global and thermal radiation, precipitation, and atmospheric pressure. An account is given of the methods of measurement, measurement accuracy and operating experience gathered during several years. As an example of the versatile application of the data stored a statistical evaluation of humidity conditions is performed taking into account the length of visible cooling tower plumes. Work concentrates on the representation of the seasonal and daily distribution of situations during which the visible plumes get longer than 2.5 km. (orig.)

319

New system of cooling download Arrocampo. Project TEVA  

International Nuclear Information System (INIS)

Project TEVA The new system is basically a mechanical forced-cooling tower, a system of pumping water from Arrocampo, pipes and valves supply a collection basin water tower, a channel to drain the existing auxiliary spillway own shot dam and a new power line from the Central.

320

iDataCool: HPC with Hot-Water Cooling and Energy Reuse  

Digital Repository Infrastructure Vision for European Research (DRIVER)

iDataCool is an HPC architecture jointly developed by the University of Regensburg and the IBM Research and Development Lab B\\"oblingen. It is based on IBM's iDataPlex platform, whose air-cooling solution was replaced by a custom water-cooling solution that allows for cooling water temperatures of 70C/158F. The system is coupled to an adsorption chiller by InvenSor that operates efficiently at these temperatures. Thus a significant portion of the energy spent on HPC can be r...

Meyer, Nils; Ries, Manfred; Solbrig, Stefan; Wettig, Tilo

2013-01-01

 
 
 
 
321

Technical analysis of a river basin-based model of advanced power plant cooling technologies for mitigating water management challenges  

Science.gov (United States)

Thermoelectric power plants require large volumes of water for cooling, which can introduce drought vulnerability and compete with other water needs. Alternative cooling technologies, such as cooling towers and hybrid wet-dry or dry cooling, present opportunities to reduce water diversions. This case study uses a custom, geographically resolved river basin-based model for eleven river basins in the state of Texas (the Brazos and San Jacinto-Brazos, Colorado and Colorado-Brazos, Cypress, Neches, Nueces, Red, Sabine, San Jacinto, and Trinity River basins), focusing on the Brazos River basin, to analyze water availability during drought. We utilized two existing water availability models for our analysis: (1) the full execution of water rights—a scenario where each water rights holder diverts the full permitted volume with zero return flow, and (2) current conditions—a scenario reflecting actual diversions with associated return flows. Our model results show that switching the cooling technologies at power plants in the eleven analyzed river basins to less water-intensive alternative designs can potentially reduce annual water diversions by 247-703 million m3—enough water for 1.3-3.6 million people annually. We consider these results in a geographic context using geographic information system tools and then analyze volume reliability, which is a policymaker's metric that indicates the percentage of total demand actually supplied over a given period. This geographic and volume reliability analysis serves as a measure of drought susceptibility in response to changes in thermoelectric cooling technologies. While these water diversion savings do not alleviate all reliability concerns, the additional streamflow from the use of dry cooling alleviates drought concerns for some municipal water rights holders and might also be sufficient to uphold instream flow requirements for important bays and estuaries on the Texas Gulf coast.

Stillwell, Ashlynn S.; Clayton, Mary E.; Webber, Michael E.

2011-07-01

322

A heat dissipating model for water cooling garments  

Directory of Open Access Journals (Sweden)

Full Text Available A water cooling garment is a functional clothing used to dissipate human body’s redundant energy in extravehicular environment or other hot environment. Its heat dissipating property greatly affects body’s heat balance. In this paper, a heat dissipating model for the water cooling garment is established and verified experimentally using the experimental thermal-manikin.

Yang Kai

2013-01-01

323

Storage of HLW in engineered structures: air-cooled and water-cooled concepts  

International Nuclear Information System (INIS)

A comparative study on an air-cooled and a water-cooled intermediate storage of vitrified, highly radioactive waste (HLW) in overground installations has been performed by Nukem and Belgonucleaire respectively. In the air-cooled storage concept the decay heat from the storage area will be removed using natural convection. In the water-cooled storage concept the decay heat is carried off by a primary and secondary forced-cooling system with redundant and diverse devices. The safety study carried out by Nukem used a fault tree method. It shows that the reliability of the designed water-cooled system is very high and comparable to the inherent, safe, air-cooled system. The impact for both concepts on the environment is determined by the release route, but even during accident conditions the release is far below permissible limits. The economic analysis carried out by Belgonucleaire shows that the construction costs for both systems do not differ very much, but the operation and maintenance costs for the water-cooled facility are higher than for the air cooled facility. The result of the safety and economic analysis and the discussions with the members of the working group have shown some possible significant modifications for both systems, which are included in this report. The whole study has been carried out using certain national criteria which, in certain Member States at least, would lead to a higher standard of safety than can be justified on any social, political or economic grounds

324

Model-based advanced water cooled reactor  

International Nuclear Information System (INIS)

At present, no easy-to-maintain, high-temperature capable monitoring and control systems exist for Generation-IV reactors. Since these reactors are planned to operate with temperature above 1000 deg. C and high neutron flux, accurate measurements are needed to identify hot spots, control in-core power distribution and other parameters that are critical to the safe operation of the reactors. Also, an on-line gamma-spectroscopy approach is the most accurate method to perform the fuel monitoring, especially for reactors with on-line refueling. It is important to operate a reactor in the minimum fuel loading state so that any physical changes in configuration are self-correcting. The preliminary analysis shows that modification of current water-cooled reactors is cheaper and safer than storing spent fuel. In addition, our test facilities will either use the General Atomics; inherently safe fuel technology or will not employ any fissionable material. Relationships will be developed between the key design parameters including system size, power level, and neutron flux. The advanced annular fuel design could be initiated in collaboration with Massachusetts Institute of Technology, as was previously discussed among several MIT researchers

325

Study on water cooled high conversion reactor  

Energy Technology Data Exchange (ETDEWEB)

As a part of study on advanced reactors for the future, conceptual design of high conversion water cooled reactors is being studied, aiming at the contribution to nuclear fuel cycle by the LWR technology, since the utilization of LWRs will extend over a long period of time . We are studying on the reactor core concepts for BWR and PWR reactor systems. As for BWR system, three types of reactor cores are investigating for three different design goals; long operation period, high conversion ratio and high applicability for the existing BWR system. In all the cases, we have obtained a fair prospect of a large core concept with a capacity of 1,000 MWe class having negative void reactivity coefficient. This study is a part of JAERI-JAPCO (Japan Atomic Power Company) cooperative studies. Various kinds of conceptual designs will be created until the end of FY 1999. The designs will be checked and reviewed at that time, then experimental studies on the realization of the concepts will start with further design works from FY 2000. (author)

Ochiai, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1999-12-01

326

Validation of the kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this report is to present a validation of a previously described kinetic model which was developed to predict the composition of chlorinated fresh water discharged from power plant cooling systems. The model was programmed in two versions: as a stand-alone program and as a part of a unified transport model developed from consistent mathematical models to simulate the dispersion of heated water and radioisotopic and chemical effluents from power plant discharges. The results of testing the model using analytical data taken during operation of the once-through cooling system of the Quad Cities Nuclear Station are described. Calculations are also presented on the Three Mile Island Nuclear Station which uses cooling towers.

Lietzke, M.H.

1977-10-31

327

Validation of the kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems  

International Nuclear Information System (INIS)

The purpose of this report is to present a validation of a previously described kinetic model which was developed to predict the composition of chlorinated fresh water discharged from power plant cooling systems. The model was programmed in two versions: as a stand-alone program and as a part of a unified transport model developed from consistent mathematical models to simulate the dispersion of heated water and radioisotopic and chemical effluents from power plant discharges. The results of testing the model using analytical data taken during operation of the once-through cooling system of the Quad Cities Nuclear Station are described. Calculations are also presented on the Three Mile Island Nuclear Station which uses cooling towers

328

Water cooled reactor technology: Safety research abstracts no. 1  

International Nuclear Information System (INIS)

The Commission of the European Communities, the International Atomic Energy Agency and the Nuclear Energy Agency of the OECD publish these Nuclear Safety Research Abstracts within the framework of their efforts to enhance the safety of nuclear power plants and to promote the exchange of research information. The abstracts are of nuclear safety related research projects for: pressurized light water cooled and moderated reactors (PWRs); boiling light water cooled and moderated reactors (BWRs); light water cooled and graphite moderated reactors (LWGRs); pressurized heavy water cooled and moderated reactors (PHWRs); gas cooled graphite moderated reactors (GCRs). Abstracts of nuclear safety research projects for fast breeder reactors are published independently by the Nuclear Energy Agency of the OECD and are not included in this joint publication. The intention of the collaborating international organizations is to publish such a document biannually. Work has been undertaken to develop a common computerized system with on-line access to the stored information

329

Results of cooling of dies with water mist  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Intensification of die casting of car silumins wheels with use of the water mist instead of compressed air dies cooling in low pressure casting process were presented in the paper.Design/methodology/approach: Examinations of casting process parameters were carried out on the industrial workstation of casting car wheels under the low pressure and also with Magma computer simulating system.Findings: The temperature and the range of its variation were presented in characteristic points of the casting and the cooled die with use the compressed air and with the water mist. A scheme of the device for generating the water mist cooling the die and also the pictures of simulation of wheels casting process for researched cooling methods was given.Research limitations/implications: The manufacturing technologies with the permanent mould.Practical implications: Using the water mist to cooling of dies in die casting and low pressure casting process to intensify of cooling the die and to reduce the amount of casting spoilage.Originality/value: Using the water mist to cooling increases intensity of cooling of the die and the cast. It makes shorter the cycle of casting process as well as reduces the porosity of casts and increases mechanical properties: Rp0,2, Rm, A5 and HB.

R. W?adysiak

2007-11-01

330

Naegleria fowleri in cooling waters of power plants  

Energy Technology Data Exchange (ETDEWEB)

Six strains of nonvirulent and three strains of virulent variants of Naegleria fowleri amoebae were isolated from the examined cooling water samples from 9 power plants. The virulent variants were obtained solely from effluents discharged from power plants with a closed-circuit cooling N. fowleri was not detected outside the reach of the thermal pollution. A disinfection of out-flowing cooling water seems to be an unnecessary investment in our climate. Warm discharge water should under no conditions be used directly for sports and recreational purposes.

Cerva, L.; Kasprzak, W.; Mazur, T.

1982-01-01

331

Corrosion of carbon steel in the stagnant cooling water  

International Nuclear Information System (INIS)

In the cooling water system treated with zinc-polyphosphate inhibitor, the relationship between inhibitor performance and corroded conditions of heat exchangers was studied. When cooling water system was kept in wet lay-up state, inhibitor concentration in the water jucket of heat exchangers decreased 15 ? 30 percent per week, and turbidity increased 30 ? 150 percent per week. These results show that corrosion rate of shell-plate in stagnant cooling water is more rapid than in flowing cooling water. Applied trouble discrimination method based on SiO2 ratio to the chemical composition of corrosion products, corrosion trouble was observed in shell-plates of heat exchangers. When cooling water system is kept in wet lay-up state, cooling water in the water jucket of heat exchangers is isolated for mouter system. In this perfectly closed system, zinc-polyphosphate inhibitor was not effective for protection of corrosion of carbon steel, and metal (carbon steel) dissolution occurred. However, in the perfectly closed system, since the dissolved oxygen content of the system was reduced with lapse of time, reduction process at cathodic region was stopped, so corrosion of metals seemed to be inhibited. (author)

332

Design Challenge: How to Keep Items Cool in Boiling Water?  

Science.gov (United States)

This is a design challenge about heat transfer and insulation. Learners will apply the scientific method to design and build a container that will keep items cool when placed in boiling water. They will practice collaboration in team-building and in teamwork. This is lesson 4 of 4 at the Grade 9-12 range of the module, Staying Cool.

333

From chip to cooling tower data center modeling: Part I Influence of server inlet temperature and temperature rise across cabinet  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To achieve reductions in the power consumption of the data center cooling infrastructure, the current strategy in data center design is to increase the inlet temperature to the rack, while the current strategy for energy-efficient system thermal design is to allow increased temperature rise across the rack. Either strategy, or a combination of both, intuitively provides enhancements in the coefficient of performance (COP) of the data center in terms of computing energy usage relative to cooli...

Breen, Tj; Walsh, Ej; Punch, J.; Shah, Aj; Bash, Ce

2010-01-01

334

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

Energy Technology Data Exchange (ETDEWEB)

Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to determine if WSAC technology could cool process water at cycles of concentration considered highly scale forming for mechanical draft cooling towers. At the completion of testing, there was no visible scale on the heat transfer surfaces and cooling was sustained throughout the test period. The application of the WARMF decision framework to the San Juan Basis showed that drought and increased temperature impact water availability for all sectors (agriculture, energy, municipal, industry) and lead to critical shortages. WARMF-ZeroNet, as part of the integrated ZeroNet decision support system, offers stakeholders an integrated approach to long-term water management that balances competing needs of existing water users and economic growth under the constraints of limited supply and potential climate change.

C. McGowin; M. DiFilippo; L. Weintraub

2006-06-30

335

77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Science.gov (United States)

...Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory...Test Programs for Water-Cooled Nuclear Power Plants.'' This guide describes...ITPs) for light water cooled nuclear power plants. DATES: Submit...

2012-12-07

336

78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants  

Science.gov (United States)

...Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory...Test Programs for Water-Cooled Nuclear Power Plants.'' This guide describes...ITPs) for light water cooled nuclear power plants. ADDRESSES: Please...

2013-06-12

337

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.  

Science.gov (United States)

...Hexavalent chromium-based water treatment chemicals in cooling systems. 749.68 Section...SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and Cooling Systems...Hexavalent chromium-based water treatment chemicals in cooling systems. (a)...

2010-07-01

338

Thermodynamic analysis of cooling systems for nuclear power stations condenser  

International Nuclear Information System (INIS)

This work is an attempt to concentrate on the thermodynamic theory, the engineering solution and the quantities of water needed for the operation of a wet as well as a wet/dry cooling towers coupled to a nuclear turbine condenser,. About two hundred variables are needed for the design of a condenser - cooling tower system. In order to make the solution fast and handy, a computer model was developed. The amount of water evaporation from cooling towers is a function of the climate conditions prevailing around the site. To achieve an authentic analysis, the meteorological data of the northern Negev was used. The total amount of water necessary to add to the system in a year time of operation is large and is a function of both the blow-down rate and the evaporation. First estimations show that the use of a combined system, wet/dry cooling tower, is beneficial in the northern Negev area. Such a system can reduce significantly the amount of wasted fresh water. Lack of international experience is the major problem in the acceptability of wet/dry cooling towers. The technology of a wet cooling tower using sea water is also discussed where no technical or engineering limitations were found. This work is an attempt to give some handy tools for making the choice of cooling systems for nuclear power plants easier

339

Upgrade of the cooling water temperature measures system for HLS  

International Nuclear Information System (INIS)

The cooling water temperature measures system for HLS (Hefei Light Source) adopts EPICS to the developing platform and takes the intelligence temperature cruise instrument for the front control instrument. Data of temperatures are required by IOCs through Serial Port Communication, archived and searched by Channel Archiver. The system can monitor the real-time temperatures of many channels cooling water and has the function of history data storage, and data network search. (authors)

340

Supplementary report: cooling water systems for Darlington G.S  

International Nuclear Information System (INIS)

This report summarizes Ontario Hydro's existing aquatic environmental programs, presents results of these investigations, and outlines plans and activities for expanded aquatic environment studies including the evaluation of alternative cooling systems. This report outlines specific considerations regarding possible alternative cooling arrangements for the Darlington station. It concludes with a recommendation that a study be initiated to examine the potential benefits of using the heated discharge water in a warm water recreational centre. (author)

 
 
 
 
341

Evaluation of cooling water treatment programme at RAPS-3 and 4 with reference to chlorination and microbial control  

International Nuclear Information System (INIS)

Water from Rana Pratap Sagar Lake is used in Rajasthan Atomic Power Station (RAPS) units 3 and 4 for cooling the condenser system. As the lake water is rich in nutrients and microflora, investigations were carried out on the nutrient quality, microflora distribution and chlorine decay to evaluate the cooling water treatment programme. Algal growth in emergency storage makeup water pools, weed growth on the cooling tower decks and biofilm growth on various materials (carbon steel, stainless steel, admiralty brass and cupronickel) were studied with an objective to understand the reasons for corrosion and failure of fire water pipeline. Visual examination showed that the emergency makeup water pools were infested with green algae and cyano-bacterial mats. Some algal growth was observed on induced draft cooling tower-3 structures. The bacterial counts in various water samples were low, except in emergency makeup water pool. Sulphate reducing bacteria (SRB) were present in makeup and demineralised waters. Chlorophyll pigment analysis showed that the makeup and emergency storage water pool had abundant algal growth. To prevent biofouling, chlorine is dosed at the rate of 7 kg/hr for 10 minutes; free residual oxidant (FRO) and chlorine decay were monitored at regular intervals. After 24 hrs, biofilm thickness on different materials ranged from 27-45 ?m. However, the thickness was reduced by 50 % after exposure to 2 ppm of chlorine for 15 minutes. In further investigations, it was found that the anion resin beads of demineraliser plant were infested with filamentous microbes. Hence, It is recommended to treat the feed water of DM plant. Tubercles were observed inside the failed fire water carbon steel pipeline and on removing the tubercles concentric ring patterns, typical signatures of SRB corrosion were observed. For controlling the biofouling problem in the cooling water system, it is recommended to maintain a chlorine dose of 2.3 ppm (which gives 0.8 ppm FRO) for two hours in every shift. To control the algal growth in the emergency storage water pools, it is recommended to dose 4.0 ppm of sodium hypochlorite on alternate days. (author)

342

Water mist effect on cooling process and microstructure of silumin  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents the results of the process of crystallization and cooling of the AlSi11 silumin and temperature distribution in the wall of iron and bronze research casting die in the temperature field of 750 to 100°C in casting of the silumin with use of water cooling mist in the air at a pressure of 0.30 to 0.40MPa and the water from 0.35 to 0.45MPa. Showing the nature and rate of change of temperature in die casting and the formation of temperature gradient on the thickness of the die casting wall in the direction of the nozzle surface of the outer wall of the cooling die casting. Using derivation curves and regression equations there has been compared: the mean and instantaneous rates of crystallization and cooling cast in values of 750 ÷ 200°C. In addition, there are presented the differences arising from the microstructure change of the die’s type and thickness of its walls, the thickness of cast and the fact of using cooling water mist. The conduct of the changes of the hardness of the cast as a result of the applied cooling method of the die casting. It has been shown that the use of water mist with a variability of the die’s wall thickness in the cooling zone gives control of the crystallization process, microstructure and mechanical properties of the final silumin cast.

R. W?adysiak

2009-07-01

343

An improved water cooled nuclear reactor and pressuriser assembly  

International Nuclear Information System (INIS)

A water cooled nuclear reactor is described which comprises a reactor core, a primary water coolant circuit and a pressuriser arranged as an integral unit in a pressure vessel. The pressure vessel is divided into an upper and a lower chamber by a casing. The reactor core and primary water coolant circuit are arranged in the lower chamber and the pressuriser is arranged in the upper chamber. A plurality of spray pipes interconnect a steam space of the pressuriser with the downcomer of the primary water coolant circuit below a heat exchanger. A plurality of surge ports interconnect a water space of the pressuriser with the primary water coolant circuit. The surge ports have hydraulic diodes so that there is a low flow resistance for water from the water space of the pressuriser to the primary water coolant circuit and high flow resistance in the opposite direction. The spray pipes provide a desuperheating spray of cooled water into the pressuriser during positive volume surges of the primary water coolant. The pressuriser arrangement may also be applied to integral water cooled reactors with separate pressurisers and to dispersed pressurised water reactors. The surge ports also allow water to flow by gravity to the core in an emergency. (author)

344

Water cooling system for sintering furnaces of nuclear fuel pellets  

International Nuclear Information System (INIS)

This work has as a main objective to develop a continuous cooling water system, which is necessary for the cooling of the sintering furnaces. This system is used to protect them as well as for reducing the water consumption, ejecting the heat generated into this furnaces and scattering it into the atmosphere in a fast and continuous way. The problem was defined and the reference parameters established, making the adequate research. The materials were selected as well as the length of the pipeline which will carry the secondary refrigerant fluid (water). Three possible solutions were tried,and evaluated, and from these, the thermal and economically most efficient option was selected. The layout of the solution was established and the theoretical construction of a cooling system for liquids using dichlorofluoromethane (R-22), as a refrigerant and a air cooled condenser, was accomplished. (Author)

345

Cooling water conditioning and quality control for tokamaks  

Energy Technology Data Exchange (ETDEWEB)

Designers and operators of Tokamaks and all associated water cooled, peripheral equipment, are faced with the task of providing and maintaining closed-loop, low conductivity, low impurity, cooling water systems. Most of these systems must provide large volumes of high quality cooling water at reasonable cost and comply with local and state government orders and EPA mandated national pretreatment standards and regulations. This paper discusses the DIII-D water quality requirements, the means used to obtain the necessary quality and the instrumentation used for control and monitoring. Costs to mechanically and chemically condition and maintain water quality are discussed as well as the various aspects of complying with government standards and regulations.

Gootgeld, A.M.

1995-10-01

346

Cooling water conditioning and quality control for tokamaks  

International Nuclear Information System (INIS)

Designers and operators of Tokamaks and all associated water cooled, peripheral equipment, are faced with the task of providing and maintaining closed-loop, low conductivity, low impurity, cooling water systems. Most of these systems must provide large volumes of high quality cooling water at reasonable cost and comply with local and state government orders and EPA mandated national pretreatment standards and regulations. This paper discusses the DIII-D water quality requirements, the means used to obtain the necessary quality and the instrumentation used for control and monitoring. Costs to mechanically and chemically condition and maintain water quality are discussed as well as the various aspects of complying with government standards and regulations

347

Experiences on condenser cooling water treatment programme at NAPS  

International Nuclear Information System (INIS)

The Narora Atomic Power Station has twin units of 220 MWe pressurized heavy water reactors, situated at the banks of river Ganges in Bulandshahr District of Uttar Pradesh. The plant cooling water takes the make up water supply from river Ganges after pretreatment using polyelectrolyte at two number of clariflocculators. The condenser cooling water system of the station is of open recirculating type and the clarified raw water used as a cooling medium is having a concentration cycle of cooling about 2.0. The calcium concentration in recirculating water is around 160 mg/litre as CaCO3 at full power of the unit. The Langelier Saturation Index of the recirculating water is observed to be in the range + 1.2 to + 1.8, indicating moderately high tendency, towards scale formation on heat transfer surfaces, such as condenser tubes, Turbine lubricating oil coolers and other associated heat exchangers. The condenser cooling water treatment was not envisaged in the original design. Therefore untreated surface water resulting in scale formation (0.3 to 0.5 mm thickness) due to deposition of calcium carbonate was observed in the condenser tubes of NAPS Unit 1 and 2 during initial period of operation (1989 to 1992). It was observed that the scaling on condenser tube surfaces caused increase in terminal temperature difference (TTD) from a design value of 5.5 degC to 13.0 degC. In addition to this a substantial drop in heat transfer coefficient from a value of about 2000 kcal/hr/m2/degC to 1200 kcal/hr/m2/degC occurred. On thorough review actions were initiated at NAPS to restore the heat transfer through condensers. The present paper highlights the experiences on the treatment of cooling water

348

Controlled Cooling of Hot Rolled Steel Channels by Water Spraying on the Final Cooling Bed  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this research is to design an effective and relatively simple method for controlled cooling of hot rolled steel channels by water spraying on the final cooling bed after continuous cast steel billets passing through reheating furnace and sequential rolls to form channels. The need for this research arose as the channels were being cooled by forced air draft and natural convection which brought the temperature of the channels to about 270°C (518°F at the shear stand. Steel at this temperature is too hot for convenient handling by the operators. Additional cooling by water spraying would be an acceptable solution but such cooling should be designed to enable an acceptable microstructure to be developed in the channel, as the microstructure of steel is strongly affected by nonequilibrium cooling through the eutectoid range: the mechanical properties of steel are a consequence of the microstructure. The approach followed in this investigation was first to develop a finite element method (FEM to determine the temperature profiles in the channel subjected to cooling by water spraying and natural convection and arrive at suitable water spray rates to bring the temperature of the channel at the shear stand to levels suitable for convenient handling. PATRAN was used for preprocessing and ABAQUS for processing and post processing. Next, laboratory experiments were conducted to determine the microstructure and hardness of channels at the spray rates found suitable through FEM, to suggest the water spray rate most suitable for providing a temperature convenient for handling and for developing a desirable microstructure.

Srinivas Rachamadagu

2013-12-01

349

TEVA new cooling system from the point of view electric  

International Nuclear Information System (INIS)

The objective of the project is to ensure that TEVA temperature reservoir discharge cooling Arrocampo the Torrejon-Tajo does not exceed the limit value 30 degree centigrade. To do this, we have installed a cooling system based on a cooling tower to which water is supplied by four main pumps 1100kW.

350

78 FR 64027 - Preoperational Testing of Emergency Core Cooling Systems for Pressurized-Water Reactors  

Science.gov (United States)

...NRC-2011-0129] Preoperational Testing of Emergency Core Cooling Systems for Pressurized-Water...Preoperational Testing of Emergency Core Cooling Systems for Pressurized-Water...preoperational testing of features in the emergency core cooling systems (ECCSs) of...

2013-10-25

351

Water-cooled insulated steam-injection wells  

Science.gov (United States)

Water is used as insulated coolant and heat-transfer medium for steam-injection oil wells. Approach is somewhat analogous to cooling system in liquid-propellant rocket. In addition to trapping and delivering heat to steam-injection point, water will also keep casing cooler, preventing or reducing casing failures caused by thermal stresses.

Back, L. H.; Jaffe, L. D.

1980-01-01

352

Increasing effectiveness of evaporative cooling by pre-cooling using nocturnally stored water  

International Nuclear Information System (INIS)

In this paper, a multi-step system of nocturnal radiative cooling and two-stage evaporative cooling is studied. The feasibility and potential of this system is investigated for four cities which have different climatic conditions. During the night time in summer, water is circulated from a storage tank to two radiative panels. The temperature of the water from the radiative panels decreases because of radiative heat transfer between the water in panels and night sky. During the next day, the stored cold water in the storage tank is used as coolant for a cooling coil unit. Hot outdoor air is passed through the cooling coil unit and a two-stage evaporative cooler. The results obtained demonstrate that first, the multi-step system can be considered as an alternative cooling system in some hot regions that evaporative cooling cannot be used. Second, the multi-step system has higher effectiveness than conventional two-stage evaporative coolers. Third, an energy saving of the multi-step system is between 75 and 79% compared to mechanical vapor compression systems. Consequently, this environmentally-friendly and highly-efficient system can replace the mechanical vapor compression systems. - Highlights: ? The multi-step system meets the comfort conditions in various weather conditions. ? Adding nocturnal cooling to IDEC increases the effectiveness by 9%. ? The new system expands coverage of IDEC over hot and humid weather conditions. ? The energy efficiency ratio of t? The energy efficiency ratio of the multi-step system is higher than 48.8.

353

Numerical simulation of the effects of cooling tower complexes on clouds and severe storms. Final report, September 1976-June 1979  

International Nuclear Information System (INIS)

A two-dimensional, time-dependent model was developed which gives realistic simulations of many severe storm processes - such as heavy rains, hail, and strong winds. The model is a set of partial differential equations describing time changes of momentum, energy, and mass (air and various water substances such as water vapor, cloud liquid, cloud ice, rainwater, and hail). In addition, appropriate boundary And initial conditions (taken from weather sounding data) are imposed on a domain approximately 20 km high by 20 km wide with 200 m grid intervals to complete the model. Modifications were made to the model which allow additional water vapor and heat to be added at several lower grid points, simulating effluents from a power park. Cases were run which depict realistic severe storm situations. One atmospheric sounding has a strong middle-level inversion which tends to inhibit the first convective clouds but gives rise later to a severe storm with hail and heavy rains. One other sounding is taken from a day in which a severe storm occurred in the Miami area. A third sounding depicts atmospheric conditions in which severe storms formed in the vicinity of Huron, South Dakota. The results indicate that a power park emitting 80% latent heat and 20% sensible heat has little effect on the simulated storm. A case with 100% sensible heat emission leads to a much different solution, with the simulated storm reduced in severity and the rain and hail redistributed. A case in whicain and hail redistributed. A case in which water vapor is accumulated in a region and released over a broad depth results in sightly more rain from a severe storm

354

WRI 50: Strategies for Cooling Electric Generating Facilities Utilizing Mine Water  

Energy Technology Data Exchange (ETDEWEB)

Power generation and water consumption are inextricably linked. Because of this relationship DOE/NETL has funded a competitive research and development initiative to address this relationship. This report is part of that initiative and is in response to DOE/NETL solicitation DE-PS26-03NT41719-0. Thermal electric power generation requires large volumes of water to cool spent steam at the end of the turbine cycle. The required volumes are such that new plant siting is increasingly dependent on the availability of cooling circuit water. Even in the eastern U.S., large rivers such as the Monongahela may no longer be able to support additional, large power stations due to subscription of flow to existing plants, industrial, municipal and navigational requirements. Earlier studies conducted by West Virginia University (WV 132, WV 173 phase I, WV 173 Phase II, WV 173 Phase III, and WV 173 Phase IV in review) have identified that a large potential water resource resides in flooded, abandoned coal mines in the Pittsburgh Coal Basin, and likely elsewhere in the region and nation. This study evaluates the technical and economic potential of the Pittsburgh Coal Basin water source to supply new power plants with cooling water. Two approaches for supplying new power plants were evaluated. Type A employs mine water in conventional, evaporative cooling towers. Type B utilizes earth-coupled cooling with flooded underground mines as the principal heat sink for the power plant reject heat load. Existing mine discharges in the Pittsburgh Coal Basin were evaluated for flow and water quality. Based on this analysis, eight sites were identified where mine water could supply cooling water to a power plant. Three of these sites were employed for pre-engineering design and cost analysis of a Type A water supply system, including mine water collection, treatment, and delivery. This method was also applied to a ''base case'' river-source power plant, for comparison. Mine-water system cost estimates were then compared to the base-case river source estimate. We found that the use of net-alkaline mine water would under current economic conditions be competitive with a river-source in a comparable-size water cooling system. On the other hand, utilization of net acidic water would be higher in operating cost than the river system by 12 percent. This does not account for any environmental benefits that would accrue due to the treatment of acid mine drainage, in many locations an existing public liability. We also found it likely that widespread adoption of mine-water utilization for power plant cooling will require resolution of potential liability and mine-water ownership issues. In summary, Type A mine-water utilization for power plant cooling is considered a strong option for meeting water needs of new plant in selected areas. Analysis of the thermal and water handling requirements for a 600 megawatt power plant indicated that Type B earth coupled cooling would not be feasible for a power plant of this size. It was determined that Type B cooling would be possible, under the right conditions, for power plants of 200 megawatts or less. Based on this finding the feasibility of a 200 megawatt facility was evaluated. A series of mines were identified where a Type B earth-coupled 200 megawatt power plant cooling system might be feasible. Two water handling scenarios were designed to distribute heated power-plant water throughout the mines. Costs were developed for two different pumping scenarios employing a once-through power-plant cooling circuit. Thermal and groundwater flow simulation models were used to simulate the effect of hot water injection into the mine under both pumping strategies and to calculate the return-water temperature over the design life of a plant. Based on these models, staged increases in required mine-water pumping rates are projected to be part of the design, due to gradual heating and loss of heat-sink efficiency of the rock sequence above the mines. Utilizing pumping strategy No.1 (two mines) capital costs wer

Joseph J. Donovan; Brenden Duffy; Bruce R. Leavitt; James Stiles; Tamara Vandivort; Paul Ziemkiewicz

2004-11-01

355

Effect of closed loop cooling water transit time on containment cooling  

International Nuclear Information System (INIS)

Long term containment cooling analyses in nuclear plant systems are usually conducted assuming a quasi steady-state process, that is, a steady state evaluation of the cooling system is completed for each calculational step. In reality, fluid transport in the system, and heat addition to system components may affect the heat removal rate of the system. Transient effects occurring during system startup may affect the maximum temperatures experienced in the system. It is important to ensure that such transient effects do not affect operation of the system (e.g., cause a high temperature trip). To evaluate the effect of fluid transit delays, a closed loop cooling water system model has been developed that incorporates the fluid transport times when determining the closed loop cooling system performance. This paper describes the closed loop cooling system model as implemented in the CONTEMPT-LT/028 code. The evaluation of the transient temperature response of the closed loop cooling system using the model is described. The paper also describes the effect of fluid transit time on the overall containment cooling performance

356

Assessment of effectiveness of water mist cooling of casting die  

Directory of Open Access Journals (Sweden)

Full Text Available At work research findings of the process of cooling the research casting die in the range of the 600-100°C temperature were presented and of the research-production casting die while pouring the cycle out cooled with compressed air about the pressure 0.6 MPa and the water mist about the pressure of air and water appropriately 0.3/0.35 MPa. The character and the speed of the temperature changes in the die and being formed of gradient of the temperature on the thickness partition walls were shown the die with the help of thermal and derivative curves. A course of changes was presented to the density of the thermal stream during cooling and in function of the temperature as well as results were shown a computer simulation of the process of pouring the production casting die. A scheme of the device for generating the water mist cooling the die and an image of spraying water were shown with the help of the designed rotary sprayer. They showed that applying the water mist for cooling dies is increasing the intensity of casting process and is accelerating it.

R. W?adysiak

2007-12-01

357

Effect of Oxidizing Bioxides to the Microorganism Growth at RSG-GAS Secondary Cooling Water  

International Nuclear Information System (INIS)

The RSG-GAS secondary cooling system is open recirculation cooling water. One of the problem at the recirculation open cooling water system is the microorganism growth. To control of the microorganism growth at RSG-GAS secondary cooling system carried out by addition oxidizing biocides chemical and monitoring of the microorganism growth in secondary cooling water. Monitoring of the microorganism growth carried out by determine total count of bacteria in secondary cooling water system with Dipslides Test. From the monitoring result showed that at the secondary cooling system shutdown was the microorganism growth at secondary cooling water system growth faster and than decrease growth after addition of the oxidizing biocides. (author)

358

Potentials of heat recovery from 850C LEP cooling water  

International Nuclear Information System (INIS)

Most of the cooling water from LEP has a too low temperature (30 to 400C) to be considered for economical recovery of energy. However, it is hoped that the heat from the klystrons be removed at a temperature of 850C and that this part of the LEP cooling water might be used for saving primary energy. In this study different possibilities have been investigated to make use of the waste heat for heating purposes during winter time, for saving energy in the refrigeration process in summer and for power generation. Cost estimates for these installations are also given and show their economic drawbacks. (orig.)

359

Fundamental study on submerged dischaege of condenser cooling water  

International Nuclear Information System (INIS)

Most of thermal and nuclear power plants and steel mills in Japan are located in coastal areas to get supply of a large quantity of cooling water from the sea, and the warm waste water from these plants is discharged into the water areas in front of their locations. The effect of the warm waste water on our environment, particularly, on aquatics, has come to draw public attention with the increase of their capacities and concentrated location. In the past, warm waste water was discharged to the surface layer of coastal waters through open channels. Recently, submerged discharging method is given much attention as a new discharging method of warm waste water. This method has a merit that it is capable of larger mixing ratio of the warm waste water and cool sea water around the discharge port. The submerged discharging method is classified into coastal submerged discharge and off-shore submerged discharge. The latter has a merit that it can select mixing ratio of waste water and sea water freely and that it does not have effect on the tidal zone aquatics. In this paper the authors describe the results of their theoretical and experimental studies on the behavior of warm waste water discharged off-shore, pressure loss in discharge pipes and flow rate distribution into discharge port. (auth.)

360

The insitu lining of cooling water piping  

International Nuclear Information System (INIS)

Insituform is a unique process for reconstructing damaged pipeline systems in municipal and industrial applications, including piping at power plants. A new Cured-in-Place Pipe (CIPP), or Insitupipe, is formed inside of the existing conduit by using fluid pressure, typically water, to install a flexible tube saturated with a liquid thermosetting resin; the water is then heated to harden the resin. This process results in a continuous, tight-fitting, pipe-within-a-pipe. The Insituform process is cost-effective, fast and can be used in a variety of gravity and pressure applications such as sanitary sewers, storm sewers, process piping, water systems, and ventilation systems. This process is versatile enough to be used for stand alone structural reconstruction or it can merely serve as a plastic corrosion barrier to shield existing metal pipe walls from the flow stream which may be contributing to the degradation of wall thickness. For this reason, as well as its attractive life cycle costs, more power plants are turning to this technology for life extension of existing piping

 
 
 
 
361

Experimental evaluation of the water ingression mechanism for corium cooling  

International Nuclear Information System (INIS)

Experiments were performed to assess the significance of water ingression cooling in the quenching of molten corium. Water ingression is a mechanism by which water penetrates into cracks and pores of solidified corium to enhance cooling that would otherwise be severely limited by the low thermal conductivity of the material. Quench tests were conducted with 2100 deg. C melts weighing ?75 kg composed of UO2, ZrO2 and chemical constituents of concrete. The amount of concrete in the melts was varied between 4% and 23%. The melts were quenched with an overlying water layer; three tests were conducted at a system pressure of 1 bar and four tests at 4 bar. The measured cooling rates were found to decrease with increasing concrete content and, contrary to expectations, are essentially independent of system pressure. For the lower concrete content melts, cooling rates exceeded the conduction-limited rate with the difference being attributed to the water ingression mechanism. Measurements of the permeability of the corium 'ingots' produced by the quench tests were used to obtain a second, independent set of dryout heat flux data, which exhibits the same trend as the quench test data. The data was used to validate an existing dryout heat flux model based on corium permeability associated with thermally induced cracking. The model uses the thermal and mechanical properties of the corium and coolant, and it reproduces the very particular data trend found fs the very particular data trend found for the dryout heat flux as a function of concrete content. The model predicts that water ingression cooling would be most effective for concrete-free corium mixtures such as in-vessel type melts. For such a melt the model predicts a dryout heat flux of ?400 kW/m2 at a pressure of 1 bar. The results of this study provide an experimental basis for a water ingression model that can be incorporated into computer codes used to assess accident management strategies

362

POOL WATER TREATMENT AND COOLING SYSTEM DESCRIPTION DOCUMENT  

Energy Technology Data Exchange (ETDEWEB)

The Pool Water Treatment and Cooling System is located in the Waste Handling Building (WHB), and is comprised of various process subsystems designed to support waste handling operations. This system maintains the pool water temperature within an acceptable range, maintains water quality standards that support remote underwater operations and prevent corrosion, detects leakage from the pool liner, provides the capability to remove debris from the pool, controls the pool water level, and helps limit radiological exposure to personnel. The pool structure and liner, pool lighting, and the fuel staging racks in the pool are not within the scope of the Pool Water Treatment and Cooling System. Pool water temperature control is accomplished by circulating the pool water through heat exchangers. Adequate circulation and mixing of the pool water is provided to prevent localized thermal hotspots in the pool. Treatment of the pool water is accomplished by a water treatment system that circulates the pool water through filters, and ion exchange units. These water treatment units remove radioactive and non-radioactive particulate and dissolved solids from the water, thereby providing the water clarity needed to conduct waste handling operations. The system also controls pool water chemistry to prevent advanced corrosion of the pool liner, pool components, and fuel assemblies. Removal of radioactivity from the pool water contributes to the project ALARA (as low as is reasonably achievable) goals. A leak detection system is provided to detect and alarm leaks through the pool liner. The pool level control system monitors the water level to ensure that the minimum water level required for adequate radiological shielding is maintained. Through interface with a demineralized water system, adequate makeup is provided to compensate for loss of water inventory through evaporation and waste handling operations. Interface with the Site Radiological Monitoring System provides continuous radiological monitoring of the pool water. The Pool Water Treatment and Cooling System interfaces with the Waste Handling Building System, Site-Generated Radiological Waste Handling System, Site Radiological Monitoring System, Waste Handling Building Electrical System, Site Water System, and the Monitored Geologic Repository Operations Monitoring and Control System.

V. King

2000-06-19

363

New materials for cooling systems  

International Nuclear Information System (INIS)

New materials based on rubber-vulcanite compounds and used for manufacturing cooling tower elements and coating's of hydraulic structure surfaces are proposed and their production technology is described. A series of studies on physicomechanical and chemical characteristics and hydroaerothermal parameters of cooling tower elements and coatings revealed an obvious advantage of these materials over existing ones. The materials proposed provide high efficiency of cooling tower elements, hydraulic structures and the cooling tower as a whole

364

Computational Simulation of a Water-Cooled Heat Pump  

Science.gov (United States)

A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).

Bozarth, Duane

2008-01-01

365

A process plant cooling water monitor for fission product breakthrough  

International Nuclear Information System (INIS)

A description is given of a monitor to detect fission product contamination of nuclear plant cooling water, designed such that it can be installed in close proximity to the sampling point. An appendix on the effect of temperature on a 1'' scintillation head is included examining the possibility of operating the detector at the plant stream temperature. (U.K.)

366

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.  

Science.gov (United States)

...2010-07-01 false Hexavalent chromium-based water treatment chemicals in cooling systems...CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning...749.68 Hexavalent chromium-based water treatment chemicals in cooling...

2010-07-01

367

Fuel performance in water cooled nuclear reactors  

International Nuclear Information System (INIS)

In India, experience of 80 full power years of PHWR operation and 41 full power years of BWR operation has been acquired. This has provided experience in irradiation of more than 2,50,000 fuel bundles in PHWRs and 2,700 fuel assemblies in BWRs. Experience has also been gained on irradiation of experimental fuels in pressurised water loop of research reactor, ThO2 bundles in PHWRs and (U, Pu)O2 MOX fuels in BWRs. The fuel performance in Indian reactors has shown progressive improvement over the years as a result of continuous effort to bring in improvement in fuel design, manufacturing, quality control and reactor operation. Periodic post irradiation examination (PIE) has been carried out to generate data on in-reactor performance of nuclear fuels. Keeping in view the demanding requirements for development of new generation advanced reactors, design, development of nuclear fuels and their fabrication and quality control technology are being improved. PIE facility is also being augmented with addition of a series of new hot cells and underwater pool side inspection facility. This paper provides a brief summary of fuel performance and PIE observations on research reactor and power reactor fuels. (author)

368

Double tank type water cooled reactor  

International Nuclear Information System (INIS)

An outer shroud for isolating coolants and aqueous an boric acid pool in a pressure vessel, and an isolation valve closed by electromagnetic force is disposed to a through hole of the outer shroud. When a power supply for the isolation valve is interrupted by the reduction of coolant level, the isolation valve is released by utilizing gravitational or spring force. Further, a control rod driving section for controlling the reactor power and a recycling pump driving section are disposed in a steam phase above the surface of water. When the power supply is disconnected upon abnormality, the isolation valve is released reliably since it requires no releasing power. Since the valve is usually closed completely by the electromagnetic force, the aqueous boric acid is isolated to facilitate the reactor power control. Further, since the control rod driving section and the recycling pump driving section are disposed in the steam phase, there are no extra penetration portions in the pressure vessel to improve the safety and reliability. Thus, it is possible to simplify the structure and reduce the cost of the nuclear reactor. (N.H.)

369

Natural Circulation Phenomena and Modelling for Advanced Water Cooled Reactors  

International Nuclear Information System (INIS)

The role of natural circulation in advanced water cooled reactor design has been extended with the adoption of passive safety systems. Some designs utilize natural circulation to remove core heat during normal operation. Most passive safety systems used in evolutionary and innovative water cooled reactor designs are driven by natural circulation. The use of passive systems based on natural circulation can eliminate the costs associated with the installation, maintenance and operation of active systems that require multiple pumps with independent and redundant electric power supplies. However, considering the weak driving forces of passive systems based on natural circulation, careful design and analysis methods must be employed to ensure that the systems perform their intended functions. Several IAEA Member States with advanced reactor development programmes are actively conducting investigations of natural circulation to support the development of advanced water cooled reactor designs with passive safety systems. To foster international collaboration on the enabling technology of passive systems that utilize natural circulation, in 2004 the IAEA initiated a coordinated research project (CRP) on Natural Circulation Phenomena, Modelling and Reliability of Passive Systems that Utilize Natural Circulation. Three reports were published within the framework of this CRP. The first report (IAEA-TECDOC-1474) contains the material developed for the first IAEA training course on natural circulation in water cooled nuclear power plants. The second report (IAEA-TECDOC-1624) describes passive safety systems in a wide range of advanced water cooled nuclear power plant designs, with the goal of gaining insights into system design, operation and reliability. This third, and last, report summarizes the research studies completed by participating institutes during the CRP period.

370

Virtual Tower  

International Nuclear Information System (INIS)

The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems

371

Hydrogen production using water cooled reactors  

International Nuclear Information System (INIS)

Full text: Today the world is facing tremendous energy challenges. There is a demographic explosion, which even in the most conservative scenario will drive the energy demand to high levels whilst at the same time fossil resources are becoming scarcer, and more particularly oil which bears most of the weight in the transportation area. Global warming is also becoming a major concern as the last Intergovernmental Panel on Climate Change concluded that anthropogenic greenhouse gases (GHG) are responsible for most of the observed temperature increase since the middle of the twentieth century. To address these difficulties, the first step is to look for ways to save energy whenever possible. Then, the part of GHG free sources - renewable energies (wind, solar, hydraulic, biomass) as well as nuclear energy - has to be increased in electricity production. Lastly, since the part of electricity in the final consumption of energy is less than 20% worldwide, GHG free sources of energy have to look for other markets such as transportation, whether directly (electric cars) or indirectly via hydrogen (fuel cells) and/or process heat. Hydrogen is produced currently from fossil fuels (less than 5% is produced by splitting water), and production is increasing steadily, mostly because of its use for refining crude oil and the more demanding standards of purity required. This alone is already stimulating interest in producing hydrogen by sustainable means. Moreover, the hydrogen marketnable means. Moreover, the hydrogen market is bound to expand soon: hydrogen has been identified as a leading candidate for transport applications. A near term solution is to use the hydrogen produced together with a carbon source (biomass, coal, waste, CO2) to make synthetic fuel. A longer term and more hypothetical development could be the direct use of hydrogen to power cars. Hydrogen could also be used in the iron and cement industries as a reducing agent and also help these CO2 intensive industries to significantly decrease their GHG emissions. The French context has also to be taken into account. More than 80% of electricity is produced by nuclear power plants and the hour to hour variations of the electricity demand have to be absorbed by having some plants operating at intermediate power over significant periods of time. This situation presents the double drawback of not taking full benefit of an expensive investment as well as having to take careful steps when going back to full power in order to preserve the fuel cladding. Hydrogen production during off peak periods could help regulate the electricity demand and operate the nuclear plants in base load. This then requires hydrogen production means that are flexible and not investment intensive, as they would be used only on a part time basis. CEA's strategy is hence to focus on processes which could be coupled to nuclear plants or renewable energy sources and thus be able to produce hydrogen in a sustainable way, by splitting the water molecule using GHG free electricity and/or heat. Low temperature electrolysis, even if it is used currently for limited amounts, is a mature technology which uses only electricity and can be generalized in the near future. However, this technology, which requires about 4 kWh of electricity per Nm of hydrogen produced, is energy intensive and therefore three advanced processes have also been investigated: High temperature steam electrolysis (HTSE), the Sulfur-Iodine (S-I) and Hybrid sulfur (HyS) thermochemical cycles. These processes look promising but the last two require the development of high temperature reactors, still necessitate extensive R and D work and will not be mature for industrial development within the next 20 years. Therefore, beside the optimization of LTE, our focus will be on HTSE, which will be available sooner and can also operate in autothermal mode, offering the capacity to be coupled to a LWR. In this paper, we will present the French road map for hydrogen production. (author)

372

Corrosion of hollow conductors of water cooled generator stator windings  

International Nuclear Information System (INIS)

After the observation of the plugging phenomenon, due to copper oxidation, in stator conductors of French PWR units, theoretical studies pointed out the importance of the gaseous conditioning of cooling water; research tests have been carried out on corrosion loops. The results of these works allow to understand the complex mechanism of copper oxidation in a neutral aqueous medium. The experience and the results of these experiments led EDF and Alsthom to condition with air the surge tanks of stator winding cooling systems of the CP1 series, those of Fessenheim and Bugey alternators being so conditioned since the beginning

373

Cooling rate, heating rate and aging effects in glassy water  

CERN Document Server

We report a molecular dynamics simulation study of the properties of the potential energy landscape sampled by a system of water molecules during the process of generating a glass by cooling, and during the process of regenerating the equilibrium liquid by heating the glass. We study the dependence of these processes on the cooling/heating rates as well as on the role of aging (the time elapsed in the glass state). We compare the properties of the potential energy landscape sampled during these processes with the corresponding properties sampled in the liquid equilibrium state to elucidate under which conditions glass configurations can be associated with equilibrium liquid configurations.

Giovambattista, N; Sciortino, F; Giovambattista, Nicolas; Sciortino, Francesco

2004-01-01

374

Research on water-cooled fast breeder reactors  

International Nuclear Information System (INIS)

Based on the medium and long-term program of JNC, the feasibility study for fast breeder reactors (FBRs) including related nuclear fuel cycles has been started from the 1999 fiscal year. Various options of FBR plant systems have been selected and a concept of water-cooled FBRs is one of these options. The purpose of this paper is to research and evaluate the water-cooled FBRs on the basis of literatures. The following three concepts, which premise make use of current light water reactor technology, were selected based on the research of current studies: A high conversion BWR with high void fractions and super-flat core, a high conversion PWR using heavy water as a coolant, and a supercritical pressure light water cooled FBR in which the average coolant density is so small that the breeding is possible and which can achieve the high thermal efficiency over 40%. Features of each concept were reviewed and then evaluation was performed from the following three viewpoints: The long-term targets (subject to safety, market competitiveness as an energy system, utilization of uranium resources, reduction of radioactive waste, security of the non-proliferation), the technical possibility (the structure integrity including the earthquake resistance, safety, productivity, operability and maintenance repair, difficulty of the development) and development risk. The evaluation showed that there was no problem with high developmental risk although it is difficult to achieve a high breeding ratio. However, it is desirable to confirm the thermal hydraulics of the core. Furthermore, as regards the high conversion BWR, whose study progressed the most so far, the fundamental feasibility of the breeding core was confirmed, since the method of the nuclear calculation was verified for the configuration of this study and criteria of design basis events were satisfied in the evaluation. In the 2000 fiscal year, evaluation will be made above nuclear characteristics, reactor safety and market competitiveness as an energy system for the water-cooled FBRs. (author)

375

Thermo hydraulic analysis and control of the HELOKA water cooling system  

International Nuclear Information System (INIS)

In the framework of the European Fusion Program, various Helium cooled Test Blanket Modules (TBM), such as the Helium Cooled Pebble Bed (HCPB) blanket, are proposed for tests under reactor relevant experimental conditions in ITER. To qualify the TBM module design for ITER, it is necessary to test full size mock-ups in a helium loop under realistic pressure, temperature and flow conditions. The HCPB mock-ups will be tested at the Helium Loop Karlsruhe (HELOKA) test facility, at present in advanced status of design. As far as possible, HELOKA shall operate with requirements similar to those of the Helium coolant circuit of the TBM modules in ITER. One of the main requirements of the ITER main helium loop is its ancillary water cooling system, hence the need of a Water Cooling System (WCS) for HELOKA. An existing WCS, recently used for the COMET (Core Melt Accidents) experiment, is foreseen for this purpose. The system, designed in the 80's for a heat load of about 7 MW, will be used first for the HELOKA TBM experimental campaign, where the maximum expected heat load does not exceed 5 MW, and later on, for the Test Divertor Modules (TDM). The thermal hydraulic effect has been studied using the system code RELAP5, where the pumps, the heat exchanger (HX), the cooling tower, the valves, the piping, etc., can be modeled and the whole loop can be simulated for steady state, transient accident processes or cyclic operation. In order to improve the efficiency of the system and save energy, it has been proposed to install variable frequency converters for the electric drivers and new feedback controllers. An evaluation of the overall performances of the system with the proposed feedback controllers has been conducted with computer models developed with SIMULINK. At present most of the components have been modeled using manufacturer's data. For some components, technical data are scarce and therefore a comparison with experimental data to validate the models is planned. After the validation based on the experimental data, the code will allow the testing of the control strategies for steady state, transients or cyclic operation and check the possible upgrade of the system to 10 MW (expected heat load for the HELOKA TDM experimental campaign). The control system is being modernized using state of the art hardware and software components. The upgrade also includes additional sensors and a new data acquisition system. (author)

376

Materials challenges for the supercritical water-cooled reactor (SCWR)  

International Nuclear Information System (INIS)

This paper discusses the materials requirements of the Supercritical Water-cooled Reactor (SCWR) which arise from its severe expected operating conditions: (i) Outlet Temperature (to 650 C); (ii) Pressure of 25 MPa for the coolant containment, (iii) Thermochemical stress in the presence of supercritical water, and (iv) Radiative damage (up to 150 dpa for the fast spectrum variant). These operating conditions are reviewed; the phenomenology of materials in the supercritical water environment that create the materials challenges is discussed; knowledge gaps are identified, and efforts to understand material behaviour under the operating conditions expected in the SCWR are described. (author)

377

Fuel cladding materials for supercritical-water cooled power reactors  

International Nuclear Information System (INIS)

Supercritical-water Cooled Power Reactor (SCPR), which have a higher thermal efficiency and a simpler plant concept, are much less expensive to construct and operate than conventional light water reactors. SCPR technology and production has been widely studied in many countries. In the current design of SCPR, the coolant pressure and temperature is 25MPa and 560 to 781K, respectively. The structural integrity of reactor cladding is evaluated one of the key issues for the practical application of SCPR. In this study, potential SCPR cladding materials were selected from commercially available materials and screened through mechanical tests and SCW (Supercritical-water) corrosion tests. (author)

378

Materials challenges for the Supercritical Water-Cooled Reactor (SCWR)  

International Nuclear Information System (INIS)

This paper discusses the materials requirements of the Supercritical Water-cooled Reactor (SCWR) which arise from its severe expected operating conditions: (i) Outlet Temperature (to 650 C); (ii) Pressure of 25 MPa for the coolant containment, (iii) Thermochemical stress in the presence of supercritical water, and (iv) Radiative damage (up to 150 dpa for the fast spectrum variant). These operating conditions are reviewed; the phenomenology of materials in the supercritical water environment that create the materials challenges is discussed; knowledge gaps are identified, and efforts to understand material behaviour under the operating conditions expected in the SCWR are described. (author)

379

Application of Pulsed Electrical Fields for Advanced Cooling and Water Recovery in Coal-Fired Power Plant  

Energy Technology Data Exchange (ETDEWEB)

The overall objective of the present work was to develop technologies to reduce freshwater consumption in a cooling tower of coal-based power plant so that one could significantly reduce the need of make-up water. The specific goal was to develop a scale prevention technology based an integrated system of physical water treatment (PWT) and a novel filtration method so that one could reduce the need for the water blowdown, which accounts approximately 30% of water loss in a cooling tower. The present study investigated if a pulsed spark discharge in water could be used to remove deposits from the filter membrane. The test setup included a circulating water loop and a pulsed power system. The present experiments used artificially hardened water with hardness of 1,000 mg/L of CaCO{sub 3} made from a mixture of calcium chloride (CaCl{sub 2}) and sodium carbonate (Na{sub 2}CO{sub 3}) in order to produce calcium carbonate deposits on the filter membrane. Spark discharge in water was found to produce strong shockwaves in water, and the efficiency of the spark discharge in cleaning filter surface was evaluated by measuring the pressure drop across the filter over time. Results showed that the pressure drop could be reduced to the value corresponding to the initial clean state and after that the filter could be maintained at the initial state almost indefinitely, confirming the validity of the present concept of pulsed spark discharge in water to clean dirty filter. The present study also investigated the effect of a plasma-assisted self-cleaning filter on the performance of physical water treatment (PWT) solenoid coil for the mitigation of mineral fouling in a concentric counterflow heat exchanger. The self-cleaning filter utilized shockwaves produced by pulse-spark discharges in water to continuously remove scale deposits from the surface of the filter, thus keeping the pressure drop across the filter at a relatively low value. Artificial hard water was used in the present fouling experiments for three different cases: no treatment, PWT coil only, and PWT coil plus self-cleaning filter. Fouling resistances decreased by 59-72% for the combined case of PWT coil plus filter compared with the values for no-treatment cases. SEM photographs showed much smaller particle sizes for the combined case of PWT coil plus filter as larger particles were continuously removed from circulating water by the filter. The x-ray diffraction data showed calcite crystal structures for all three cases.

Young Cho; Alexander Fridman

2009-04-02

380

A circulating water cooling system for a CAMAC crate  

International Nuclear Information System (INIS)

This paper describes a circulating water cooling system used at SLAC for cooling and maintaining cleanliness of the SLC type Camac Crates. A fully loaded Camac Crate can dissipate 1 kW of power. Recent additions to our instrumentation and control systems have resulted in the installation of Camac Crates in a rather hostile environment. The racks containing the Crates are situated in the Klystron Gallery. This gallery is not much more than a two-mile-long unheated, uncooled, unclean metal shed. On a warm day temperatures of 1200F have been measured; and over the years, dust layers of 1/2 inch can accumulate. It is because of this hostile environment that a cooling system has been designed. The system consists of the loaded Camac Crate, a circulating water heat exchanger called a Chiller Chassis, and a Blower Chassis to circulate the air within the closed system. To enclose the system, a lightweight aluminum shroud has been fabricated. The shroud is easily removed for maintenance. It works to reduce the volume of air that has to be cooled and to maintain a measure of cleanliness that is deemed necessary for continued satisfactory operation of these systems over the next few years

 
 
 
 
381

Economic competitiveness requirements for evolutionary water cooled reactors  

International Nuclear Information System (INIS)

This paper analyses the necessary economic conditions for evolutionary water cooled reactors to be competitive. Utilising recent national cost data for fossil-fired base load plants expected to be commissioned by 2005 -2010, target costs for nuclear power plants are discussed. Factors that could contribute to the achievement of those targets by evolutionary water cooled reactors are addressed. The feed-back from experience acquired in implementing nuclear programmes is illustrated by some examples from France and the Republic of Korea. The paper discusses the impacts on nuclear power competitiveness of globalisation and deregulation of the electricity market and privatisation of the electricity sector. In addition, issues related to external cost internalisation are considered. (author)

382

Balancing passive and active systems for evolutionary water cooled reactors  

International Nuclear Information System (INIS)

Advanced concepts of the water-cooled reactors are intended to improve safety, economics and public perception of nuclear power. The potential inclusion of new passive means in addition or instead of traditional active systems is being considered by nuclear plant designers to reach these goals. With respect to plant safety, application of the passive means is mainly intended to simplify the safety systems and to improve their reliability, to mitigate the effect of human errors and equipment malfunction. However, some clear drawbacks and the limited experience and testing of passive systems may raise additional questions that have to be addressed in the design process for each advanced reactor. Therefore the plant designer should find a reasonable balance of active and passive means to effectively use their advantages and compensate their drawbacks. Some considerations that have to be taken into account when balancing active/passive means in advanced water-cooled reactors are discussed in this paper. (author)

383

Passive safety features in current and future water cooled reactors  

International Nuclear Information System (INIS)

Better understanding of the passive safety systems and components in current and future water-cooled reactors may enhance the safety of present reactors, to the extend passive features are backfitted. This better understanding should also improve the safety of future reactors, which can incorporate more of these features. Passive safety systems and components may help to prevent accidents, core damage, or release radionuclides to the environment. The Technical Committee Meeting which was hosted by the USSR State Committee for Utilization of Nuclear Energy was attended by about 80 experts from 16 IAEA Member States and the NEA-OECD. A total of 21 papers were presented during the meeting. The objective of the meeting was to review and discuss passive safety systems and features of current and future water cooled reactor designs and to exchange information in this area of activity. A separate abstract was prepared for each of the 21 papers published in this proceedings. Refs, figs and tabs

384

USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Produced water is generated nationally as a byproduct of oil and gas production. Seven states generate 90 percent of the produced water in the continental US. About 37 percent of the sources documented in the US Geological Survey's (USGS) Produced Waters Database have a TDS of less than 30,000 mg/l. This is significant because produced water treatment for reuse in power plants was found to be very costly above 30,000 mg/l TDS. For the purposes of this report, produced water treatment was assessed using the technologies evaluated for the San Juan Generating Station (SJGS) in Deliverable 3, Treatment and Disposal Analysis. Also, a methodology was developed to readily estimate capital and operating costs for produced water treatment. Two examples are presented to show how the cost estimating methodology can be used to evaluate the cost of treatment of produced water at power plants close to oil and gas production.

Kent Zammit; Michael N. DiFilippo

2005-01-01

385

Advanced technologies for water cooled reactors 1990. Pt. 2  

International Nuclear Information System (INIS)

The main purpose of the meeting was to review and discuss the status of national programmes, the progress achieved since the last meeting held in June 1988 in the field of advanced technologies and design trends for existing and future water cooled reactors. 24 specialists from 14 countries and the IAEA took part in the meeting and 12 papers were presented. A separate abstract was prepared for each of these papers. Refs, figs and tabs

386

A simpler, safer, higher performance cooling system arrangement for water cooled divertors  

International Nuclear Information System (INIS)

A cooling system arrangement is presented which is specifically designed for high heat flux water cooled divertors. The motivation behind the proposed open-quotes unichannelclose quotes configuration is to provide maximum safety; this design eliminates flow instabilities liable to occur in parallel channel designs, it eliminates total blockage, it promotes cross flow to counteract the effects of partial blockage and/or local hot spots, and it is much more tolerant to the effects of debonding between the beryllium armor and the copper substrate. Added degrees of freedom allow optimization of the design, including the possibility of operating at very high heat transfer coefficients associated with nucleate boiling, while at the same time providing ample margin against departure from nucleate boiling. Projected pressure drop, pumping power, and maximum operating temperatures are lower than for conventional parallel channel designs

387

W-030, AY/AZ tank farm cooling and miscellaneous instrumentation  

International Nuclear Information System (INIS)

This is the acceptance test report for construction functional testing of Project W-030 cooling systems and related instrumentation. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The Tank Farm Cooling System consists of four forced draft cooling towers, a chilled water system, and associated controls

388

Experimental Studies of NGNP Reactor Cavity Cooling System With Water  

Energy Technology Data Exchange (ETDEWEB)

This project will investigate the flow behavior that can occur in the reactor cavity cooling system (RCCS) with water coolant under the passive cooling-mode of operation. The team will conduct separate-effects tests and develop associated scaling analyses, and provide system-level phenomenological and computational models that describe key flow phenomena during RCCS operation, from forced to natural circulation, single-phase flow and two-phase flow and flashing. The project consists of the following tasks: Task 1. Conduct separate-effects, single-phase flow experiments and develop scaling analyses for comparison to system-level computational modeling for the RCCS standpipe design. A transition from forced to natural convection cooling occurs in the standpipe under accident conditions. These tests will measure global flow behavior and local flow velocities, as well as develop instrumentation for use in larger scale tests, thereby providing proper flow distribution among standpipes for decay heat removal. Task 2. Conduct separate-effects experiments for the RCCS standpipe design as two-phase flashing occurs and flow develops. As natural circulation cooling continues without an ultimate heat sink, water within the system will heat to temperatures approaching saturation , at which point two-phase flashing and flow will begin. The focus is to develop a phenomenological model from these tests that will describe the flashing and flow stability phenomena. In addition, one could determine the efficiency of phase separation in the RCCS storage tank as the two-phase flashing phenomena ensues and the storage tank vents the steam produced. Task 3. Develop a system-level computational model that will describe the overall RCCS behavior as it transitions from forced flow to natural circulation and eventual two-phase flow in the passive cooling-mode of operation. This modeling can then be used to test the phenomenological models developed as a function of scale.

Corradini, Michael; Anderson, Mark; Hassan, Yassin; Tokuhiro, Akira

2013-01-16

389

Material selection of condenser tubes cooled by sea water  

International Nuclear Information System (INIS)

As the performances of condenser tubes are much affected by not only the properties of sea water used as coolant but also the countermeasures applied to prevent corrosion and fouling, the evaluation should be made on several cases of compatible combinations of tube materials with the requisite/desirable countermeasures. This paper discuss the material selection of condenser tubes in the light of recent knowledge of tube materials, counter measures given by auxiliary equipments against corrosion and fouling and varieties of cooling sea waters

390

Some aspects of cooling water discharges and environmental enhancement  

International Nuclear Information System (INIS)

As a consequence of the effects of cooling water discharge on the environment, the siting of nuclear power plants is approached with cautiousness. The pros and cons are discussed of siting near bodies of good quality water or in more densely populated or industrial areas. Properties and effects of thermal discharges are elaborated. The effects of heat on the activity of individual organisms, on the accumulation of organic material, on the mineralization rate of organic matter and on the transport of oxygen all have influences on recipient water bodies. Examples of siting Swedish thermal power stations are described and these indicate some negative effects. However, the results do not repudiate the possibility of good effects from the design of new cooling water intake and discharge systems that would speed up the mineralization of organic matters by addition of heat and oxygen. It is concluded that, when choosing between possible sites, areas should be selected where the available energy of the discharge can be used to improve water quality. (author)

391

Power handling capability of water-cooled beam stops  

International Nuclear Information System (INIS)

Doubling the beam power on the RFQ1-1250 linear accelerator at Chalk River and designing a 40 kW beam diagnostic system for Tokamak de Varennes required a detailed investigation into the power handling capabilities of beam stops. Different techniques for augmentation of the critical heat flux on the cooling channel surface of beam stops are reviewed. In the case of a beam stop with twisted tape inserts, the swirl flow condition yields a higher critical heat flux than that of a straight axial flow. Although a critical heat flux in the order of 10 kW/cm2 could be obtained at high flow velocities such as 45 m/s, such flows are not always practical in the design of beam stop cooling systems. At a water velocity of 4 m/s, the highest beam power density is estimated to be 1.4 kW/cm2 for a beam stop design that uses double rows of cooling tubes. A similar design, where cooling channels are machined on a common copper block, would handle a power density up to 2.6 kW/cm2. Some preliminary hydraulic test results, related to a third design where high flow turbulence is created by two rows of intersected-channels, are also reported. (Author) 5 refs., 4 figs

392

40 CFR 63.1086 - How must I monitor for leaks to cooling water?  

Science.gov (United States)

...2010-07-01 2010-07-01 false How must I monitor for leaks to cooling water? 63.1086...Exchange Systems § 63.1086 How must I monitor for leaks to cooling water? You must monitor for leaks to cooling water by...

2010-07-01

393

Devil's Tower Geology  

Science.gov (United States)

This site from the National Park Service briefly addresses the geology of Devil's Tower. The evolution of various theories on the formation of the tower are discussed. A slide show of the emplacement of the tower is also available.

National Park Service (NPS)

394

Development Project of Supercritical-water Cooled Power Reactor  

International Nuclear Information System (INIS)

A Supercritical-water Cooled Power Reactor (SCPR) development project (Feb. 2001- Mar. 2005) is being performed by a joint team consisting of Japanese universities and nuclear venders with a national fund. The main objective of this project is to provide technical information essential to demonstration of SCPR technologies through concentrating three sub-themes: 'plant conceptual design', 'thermohydraulics', and 'material and water chemistry'. The target of the 'plant conceptual design sub-theme' is simplify the whole plant systems compared with the conventional LWRs while achieving high thermal efficiency of more than 40 % without sacrificing the level of safety. Under the 'thermohydraulics sub-theme', heat transfer characteristics of supercritical-water as a coolant of the SCPR are examined experimentally and analytically focusing on 'heat transfer deterioration'. The experiments are being performed using fron-22 for water at a fossil boiler test facility. The experimental results are being incorporated in LWR analytical tools together with an extended steam/R22 table. Under the 'material and water chemistry sub-theme', material candidates for fuel claddings and internals of the SCPR are being screened mainly through mechanical tests, corrosion tests, and simulated irradiation tests under the SCPR condition considering water chemistry. In particular, stress corrosion cracking sensitivity is being investigated as well as uniform corrosion and swelling characteristics. Influences of water chemistry on the corrosion product characteristics are also being examined to find preferable water condition as well as to develop rational water chemistry controlling methods. (authors)

395

Water Purification  

Science.gov (United States)

Silver ionization water purification technology was originally developed for Apollo spacecraft. It was later used to cleanse swimming pools and has now been applied to industrial cooling towers and process coolers. Sensible Technologies, Inc. has added two other technologies to the system, which occupies only six square feet. It is manufactured in three capacities, and larger models are custom built on request. The system eliminates scale, corrosion, algae, bacteria and debris, and because of the NASA technology, viruses and waterborne bacteria are also destroyed. Applications include a General Motors cooling tower, amusement parks, ice manufacture and a closed-loop process cooling system.

1992-01-01

396

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.  

Science.gov (United States)

...emergency core cooling systems for light-water nuclear power reactors. 50...emergency core cooling systems for light-water nuclear power reactors. ...light-water nuclear power reactor fueled...emergency core cooling system...

2010-01-01

397

30 CFR 250.217 - What solid and liquid wastes and discharges information and cooling water intake information must...  

Science.gov (United States)

...What solid and liquid wastes and discharges information and cooling water intake information...solid and liquid wastes and discharges information and cooling water intake information...solid and liquid wastes and discharges information and cooling water intake...

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