WorldWideScience

Sample records for cooling tower water

  1. Hot-water cooling tower

    International Nuclear Information System (INIS)

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

  2. Asbestos in cooling-tower waters

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.A.G.

    1977-12-01

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

  3. Mycobacteria in Finnish cooling tower waters.

    Science.gov (United States)

    Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

    2014-04-01

    Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. PMID:23937212

  4. Cooling towers

    International Nuclear Information System (INIS)

    What is the effect of 0.6C (1F) temperature rise across turbines, compressors, or evaporators? Enthalpy charts indicate for every 0.6C (1F) hotter water off the cooling tower will require an additional 2 1/2% more energy cost. Therefore, running 2.2C (4F) warmer due to substandard cooling towers could result in a 10% penalty for overcoming high heads and temperatures. If it costs $1,250,000.00 a year to operate the system, $125,000.00 is the energy penalty for hotter water. This paper investigates extra fuel costs involved in maintaining design electric production with cooling water 0.6C (1F) to 3C (5.5F) hotter than design. If design KWH cannot be maintained, paper will calculate dollar loss of saleable electricity. The presentation will conclude with examining the main causes of deficient cold water production. State-of-the-art upgrading and methodology available to retrofit existing cooling towers to optimize lower cooling water temperatures will be discussed

  5. Performance of water distribution systems in a pilot cooling tower

    International Nuclear Information System (INIS)

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

  6. Factors Stimulating Propagation of Legionellae in Cooling Tower Water

    OpenAIRE

    Yamamoto, Hiroyuki; Sugiura, Minoru; Kusunoki, Shinji; Ezaki, Takayuki; Ikedo, Masanari; Yabuuchi, Eiko

    1992-01-01

    Our survey of cooling tower water demonstrated that the highest density of legionellae, ?104 CFU/100 ml, appeared in water containing protozoa, ?102 MPN/100 ml, and heterotrophic bacteria, ?106 CFU/100 ml, at water temperatures between 25 and 35°C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 105 CFU/100 ml, occurs in summer. The counts of legionellae correlated positively with increases in water temperature, pH, and protozoan counts, bu...

  7. 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

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

    International Nuclear Information System (INIS)

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

  9. 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

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

    International Nuclear Information System (INIS)

    The 0-18/0-16 and D/H isotope ratios of water from two different cooling towers were determined by mass spectrometry. The observed isotope fractionation corresponds to that known from natural evaporation or transpiration processes: cooling tower I: delta(D) = 46.8 per thousand, delta(18O) = 7.6 per thousand cooling tower II: delta(D) = 33.9 per thousand delta(18O) = 5.7 per thousand Evaluation of simple compartment models of a cooling tower and a distillation device suggests that there exists some isotope discrimination within the open trickling unit of a cooling tower analogous to that in a rectification column. In a real cooling tower, however, this effect is compensated largely by the recycling of the cooling water, resulting only in a small enrichment of the heavy isotopes. This can be understood as the result of three partial effects: 1) a fractionation in the vapor pressure equilibrium, 2) a kinetic effect due to diffusion of the water vapor into a turbulent atmosphere, and 3) an exchange effect which is proportional to relative humidity. This low enrichment of the heavy isotope excludes the technical use of cooling towers as isotope separation devices. (orig.)

  11. Coagulation chemistries for silica removal from cooling tower water.

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-01

    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.

  12. Complex development of cooling towers

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  14. Legionella adelaidensis, a new species isolated from cooling tower water.

    OpenAIRE

    Benson, R. F.; Thacker, W. L.; Lanser, J. A.; Sangster, N.; Mayberry, W. R.; Brenner, D. J.

    1991-01-01

    A Legionella-like organism (strain 1762-AUS-E) was isolated from a cooling tower of an air-conditioning system in Adelaide, South Australia, Australia. The isolate was presumptively identified as a Legionella strain by its growth requirement for L-cysteine and its cellular branched-chain fatty acids. Strain 1762-AUS-E was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization confirmed that it is a new Legionella species for which the name Legionella ...

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

    OpenAIRE

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

    1983-01-01

    We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tes...

  16. Simultaneous effects of water spray and crosswind on performance of natural draft dry cooling tower

    OpenAIRE

    Ahmadikia Hossein; Soleimani Mohsen; Gholami Ehsan

    2013-01-01

    To investigate the effect of water spray and crosswind on the effectiveness of the natural draft dry cooling tower (NDDCT), a three-dimensional model has been developed. Efficiency of NDDCT is improved by water spray system at the cooling tower entrance for high ambient temperature condition with and without crosswind. The natural and forced heat convection flow inside and around the NDDCT is simulated numerically by solving the full Navier-Stokes equations in both air and water droplet...

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

    International Nuclear Information System (INIS)

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

  18. Optimization of dry cooling towers for circulating water indirect cooling in the thermal power plants

    International Nuclear Information System (INIS)

    A mathematical model is presented to design dry cooling tower systems and to evaluate their off-design performances. The influence of the more important thermal, hydraulic and geometric parameters on the tower is shown. A preliminary 'optimum' is predicted by means of a computer code. Moreover the influence of the designed cooling system on the performance of thermal power plants is analysed

  19. Simultaneous effects of water spray and crosswind on performance of natural draft dry cooling tower

    Directory of Open Access Journals (Sweden)

    Ahmadikia Hossein

    2013-01-01

    Full Text Available To investigate the effect of water spray and crosswind on the effectiveness of the natural draft dry cooling tower (NDDCT, a three-dimensional model has been developed. Efficiency of NDDCT is improved by water spray system at the cooling tower entrance for high ambient temperature condition with and without crosswind. The natural and forced heat convection flow inside and around the NDDCT is simulated numerically by solving the full Navier-Stokes equations in both air and water droplet phases. Comparison of the numerical results with one-dimensional analytical model and the experimental data illustrates a well-predicted heat transfer rate in the cooling tower. Applying water spray system on the cooling tower radiators enhances the cooling tower efficiency at both no wind and windy conditions. For all values of water spraying rate, NDDCTs operate most effectively at the crosswind velocity of 3m/s and as the wind speed continues to rise to more than 3 m/s up to 12 m/s, the tower efficiency will decrease by approximately 18%, based on no-wind condition. The heat transfer rate of radiator at wind velocity 10 m/s is 11.5% lower than that of the no wind condition. This value is 7.5% for water spray rate of 50kg/s.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-02-01

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

  1. Water vapour rises from the cooling towers for the ATLAS detector at Point 1

    CERN Multimedia

    Brice, Maximilien

    2015-01-01

    Electronics on the ATLAS detector produce heat when the experiment is running. An elaborate cooling system keeps the detector from overheating. On the surface, the warm water vapour that rises from the detector 100metres underground is clearly visible from the ATLAS cooling towers on the CERN Meyrin site in Switzerland.

  2. Water tower

    CERN Multimedia

    1970-01-01

    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.

  3. 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

  4. Atmospheric cooling tower with reduced plume

    International Nuclear Information System (INIS)

    The cooling tower, usable in thermal-electric power plants, has a vertical chimney having a central water tower fed with water to be cooled, a pipe network distributing water coming from the water tower and dispersing it in flows streaming down on a packing, and a basin to receive the water cooled by contact with an air flow passing through apertures at the lower part of the chimney and flowing up through the chimney. The cooling tower has inlet air pipes for the said apertures to a zone of the chimney situated beyond the streaming zone, the said pipes being arranged such their surface is swept by water to be cooled

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

    OpenAIRE

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

    2014-01-01

    We present the draft genome sequence of Legionella massiliensis strain LegAT, 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.

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

    OpenAIRE

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

    1985-01-01

    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, Ill., and Los Angeles, Calif., during outbreaks of nosocomial legionellosis. The fifth strain was isolated from water collected from an industrial cooling tower in Jamestown, N.Y. The strains exhibited biochemical reactions typical of Legionella species and were gram-negative motile rods which grew on buffered charcoa...

  7. 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 densi 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

  8. Hydraulic works study of Golfech cooling towers

    International Nuclear Information System (INIS)

    The GOLFECH Nuclear Power Plant cooling towers (PWR 2 x 1300 MWe), built by SCAM for EDF (French National Electricity Authority), have certain characteristics, including: tower height - 178.50 metres; shell support - made up of a profiled lintel resting on piles; cooled water recovery system installed immediately below the fill; and cold water basin built outside the cooling tower. This paper deals only with the hydraulic circuit design (warm water inlet, cooled water recovery, cooled water return) with particular emphasis on the limitations of conventional methods of hydraulic sizing and, the necessity to carry out tests using models in order to dimension such works

  9. Experimental investigations on the contribution of the splash-zones in counter-flow cooling towers for water cooling

    International Nuclear Information System (INIS)

    The relatively high cost of cooling tower packs has led to investigate the contribution of the splash-zones in counter-flow cooling towers, and thereby to determine whether the pack could not be reduced so far, as to be - under certain circumstance - completely eliminated. In this case, one would come to a pure splash cooling tower which would contain inside the equipment required for drop formation only. This problem was investigated experimentally, and it was found that the pack of such a cooling tower could not be eliminated without a reduction in tower effectiveness. (orig.)

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

    OpenAIRE

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

    1991-01-01

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

  11. New painting on Mochovce cooling towers

    International Nuclear Information System (INIS)

    New protective painting on the south cooling towers is included in the maintenance and modernization project. Slovenske elektrarne have modernized not only concrete surface of the civil structure, but also internal technology of the cooling tower and its cooing efficiency is increased without increasing consumption of the cooling water. The project will continue this and following year on towers of the units No. 1 and 2 at the Mochovce Nuclear Power Plant. Similar works have been already performed on the cooling towers on units 3 and 4 at the Bohunice Nuclear Power Plant and Mochovce Nuclear Power Plant units 3 and 4. (author)

  12. Recent developments in cooling towers

    International Nuclear Information System (INIS)

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

  13. Discussion on numerical simulation techniques for patterns of water vapor rise and droplet deposition at NPP cooling tower

    International Nuclear Information System (INIS)

    Based on the working principle of cooling tower, analysis and comparison are made of both advantages and disadvantages of the numerical simulation models, such as ORFAD, KUMULUS, ISCST:A, ANL/UI, CFD etc., which predict the rise and droplet deposition pattern of cooling tower water vapor. The results showed that, CFD model is currently a better model that is used of three-dimensional Renault fluid flow equations predicting the rise and droplet deposition pattern of cooling tower water vapor. The impact of the line trajectory deviation and the speed change inn plume rising is not considered in any other models, and they can not be used for prediction of particle rise and droplet deposition when a larger particle or large buildings in the direction of cooling tower. (authors)

  14. 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)

  15. The future cooling tower; Fremtidens koeletaarn

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  16. Environmental impact assessment of cooling towers

    International Nuclear Information System (INIS)

    Downstream and downwind environmental impact of cooling water towers is reported and evaluated. Salt and chemical concentrations affecting downstream ecology in the atmosphere and in fresh and salt water are calculated, and specific examples of large-scale effects are given. Drift losses from towers and the extent and severity of the concurrent effect of chemicals are discussed, including the effects of chromium and zinc. Tower configuration, control measures, and climatic factors influencing mist distribution are explored and reported

  17. Advances in electrolyte cooling tower technology

    International Nuclear Information System (INIS)

    Cooling towers play an important role in the production of metals by means of electrowinning. These towers are subject to severe operating conditions, and hence, standard cooling tower designs and practices are often not applicable. This paper reviews the operational requirements and conditions applicable to electrolyte cooling towers, specifically zinc electrolyte towers. Aspects covered include the physical factors influencing electrolyte cooling, cooling tower design, coupling of cooling towers to ventilation systems and environmental compliance requirements. (author)

  18. 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

  19. 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)

  20. Performance improving factors of cooling towers in thermal power plants

    International Nuclear Information System (INIS)

    The condensation heat of the steam, expanding in the turbine, is transferred in condenser to the circulating water, and further in the cooling tower to the surrounding. The correct dimensioning of the cooling tower enables lowering of the condensation pressure and hereby increasing of the power of turbine. This paper presents the main characteristics of the cooling towers, the choice of which, by the designing, is of great importance for proper and successful functioning of the cooling towers. (author)

  1. Predicting cooling tower plume dispersion

    International Nuclear Information System (INIS)

    An assessment of the effects of visible cooling tower plumes on the local environment can be a necessary part of any proposal for a new large industrial process. Predictions of the dispersion of plumes from cooling towers are based on methods developed for chimney emissions. However, the kinds of criteria used to judge the acceptability of cooling tower plumes are different from those used for stack plumes. The frequency of long elevated plumes and the frequency of ground fogging are the two main issues. It is shown that events associated with significant plumes visibility are dependent both on the operating characteristics of the tower and on the occurrence of certain meteorological conditions. The dependence on atmospheric conditions is shown to be fairly complex and simple performance criteria based on the exit conditions from the tower are not sufficient for assessments. (author)

  2. On some problems of operation of circulating systems with cooling tower under high hardness and mineralization of make-up water

    International Nuclear Information System (INIS)

    This presentation addresses the deposit of calcium carbonate on the packings of cooling towers. The resistance of several materials to scaling is investigated as well as the effect of the scaling on the performance of the cooling tower. Water treatment to reduce scaling is also addressed

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

    OpenAIRE

    Ramakrishnan, Ramkumar; Arumugam, Ragupathy

    2012-01-01

    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...

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

    OpenAIRE

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

    2007-01-01

    Water supply and Cooling Tower Water (CTW) are among the most common sources of Legionella pneumophila (LP) contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene of LP. The 5? end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5?-biotinylated p...

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

    Directory of Open Access Journals (Sweden)

    Soheili Majid

    2007-01-01

    Full Text Available Water supply and Cooling Tower Water (CTW are among the most common sources of Legionella pneumophila (LP contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene of LP. The 5? end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5?-biotinylated probes. The amplification products were detected by using proxidase-labled anti dioxygenin antibody in a colorimetric reaction. The assay detected LP present in 1 L of 5 CTW samples examined. All of the samples were Legionella positive in both culture and PCR-ELISA methods. The PCR-ELISA assay appears to exhibit high specificity and is a more rapid technique in comparison with bacterial culture method. Thus could prove suitable for use in the routine examination of industrial CTW contamination.

  6. Discussion on Energy-saving Applications of Fanless Cooling Tower

    Directory of Open Access Journals (Sweden)

    Kuang-Cheng Yu

    2011-01-01

    Full Text Available Cooling tower is essential to both industrial development and comfortable living. Its development is closely related to human civilization and quality of life. To achieve the cooling effects and the efficiency performance of high inlet/outlet water temperature difference (?t of cooling towers, a number of modern high technologies have been applied, while the design of cooling towers focuses on lightweight, compact size, elegant appearance, and durability. This study studied the performance of fanless cooling tower when applied in a chiller cooling water system of the central air-conditioning in a hospital and discussed the problems and solutions that the fanless cooling tower encountered during practical use and explored whether there is any room to improve energy conservation according to the data recorded in the process of operation. This study also verified the performance and advantages as specified by the manufacturer to provide a reference to the design and installation of same type cooling towers in the future.

  7. Counter-Flow Cooling Tower Test Cell

    OpenAIRE

    Dvo?ák Lukáš; Noži?ka Ji?í

    2014-01-01

    The article contains a design of a functional experimental model of a cross-flow mechanical draft cooling tower and the results and outcomes of measurements. This device is primarily used for measuring performance characteristics of cooling fills, but with a simple rebuild, it can be used for measuring other thermodynamic processes that take part in so-called wet cooling. The main advantages of the particular test cell lie in the accuracy, size, and the possibility of changing the water distr...

  8. 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

  9. Discussion on Energy-saving Applications of Fanless Cooling Tower

    OpenAIRE

    Kuang-Cheng Yu; Hsin-Chang Chang; Shr-Je Hung

    2011-01-01

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

  10. Distribution of Sequence-Based Types of Legionella pneumophila Serogroup 1 Strains Isolated from Cooling Towers, Hot Springs, and Potable Water Systems in China

    OpenAIRE

    Qin, Tian; Zhou, Haijian; Ren, Hongyu; Guan, Hong; Li, Machao; Zhu, Bingqing; Shao, Zhujun

    2014-01-01

    Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discriminatio...

  11. Atmospheric emissions from power plant cooling towers

    International Nuclear Information System (INIS)

    Power plant recirculated cooling systems (cooling towers) are not typically thought of as potential sources of air pollution. However, atmospheric emissions can be important considerations that may influence cooling tower design and operation. This paper discusses relevant U.S. environmental regulations for potential atmospheric pollutants from power plant cooling towers, and various methods for estimating and controlling these emissions. (orig.)

  12. Testing of utility power plant cooling towers

    International Nuclear Information System (INIS)

    Because poor cooling tower performance can lead to expensive plant inefficiency, the number and sophistication of thermal performance tests of utility and process cooling towers is on the rise. Utility cooling tower malperformance can lead to poor heat rejection, increased turbine back pressure, increased fuel consumption, and decreased plant output. Economics demand that the towers serving these plants perform near their design point. This paper reports that cooling tower thermal performance tests can isolate one source of plant inefficiency. Benchmark tests are also performed immediately before tower rebuild or modification in order to evaluate the effectiveness of future tower alterations, or as part of a feasibility study when considering process expansion

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

    OpenAIRE

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

    1983-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ramkumar RAMAKRISHNAN

    2012-01-01

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

  15. Cooling Tower Overhaul of Secondary Cooling System in HANARO

    International Nuclear Information System (INIS)

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

  16. Physical parameters of effluent from nuclear power station cooling towers

    International Nuclear Information System (INIS)

    Physical parameters of the effluent dispersed from the wet cooling towers, i.e. mixture of the warm moist air with the entrained droplets are analysed. Understanding of the effluent physical parameters at the exit of cooling tower is important for prediction of the effluent dispersion in the environment. Mass and droplet diameter distributors of the drifted cooling water are measured in situ and also, drift eliminators are characterised experimentally. A new numerical method for heat and mass transfer evaluation in the cooling tower packing (fill) was developed, that leads to more accurate prediction for outlet air parameters in relation of plant power rate, cooling tower characteristics and atmospheric conditions. (author)

  17. 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

  18. 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)

  19. Legionella spp. in Puerto Rico cooling towers.

    OpenAIRE

    Negro?n-alvi?ra, A.; Pe?rez-suarez, I.; Hazen, T. C.

    1988-01-01

    Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, P.R., were assayed for various Legionella spp. and serogroups by using direct immunofluorescence. Several water quality parameters were also measured for each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila serogroups 1 to 6, L. bozemanii, L. micdadei, L. dumoffii, and L. g...

  20. Cooling tower analysis consideration of environmental factors

    International Nuclear Information System (INIS)

    This paper will survey the evolution of techniques used in the analysis of cooling towers over the past fifty years. It will also present two ways of analyzing the towers including the carryover on the cooling towers; performance. Cooling towers have been used in conventional fossil and nuclear power plants to remove waste heat from the condensers. This energy, in the form of low grade heat, must be transferred to the environment

  1. Legionella in Puerto Rico cooling towers

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-12-31

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

  2. ''Novel'' types of cooling towers for the power industry

    International Nuclear Information System (INIS)

    New types of cooling towers are beginning to be used abroad for the cooling circuits of nuclear power plants employing power generation units rated at 1,300 to 1,400 MW. These so-called water recovery cooling towers make use of natural draught without a droplet section. They are actually upgraded designs which were built in Europe as far back as 70 years ago. Because of the unsuitable materials then employed, these cooling towers fell into oblivion. Today, however, they are undergoing a renaissance. An upgraded design of these towers is described and compared with existing cooling towers with a droplet section. The feasibility of using these towers in Czechoslovak conditions is considered. (author)

  3. Plant Vogtle cooling tower studies

    International Nuclear Information System (INIS)

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

  4. Plant Vogtle cooling tower studies

    Energy Technology Data Exchange (ETDEWEB)

    O' Steen, L.

    2000-01-26

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

  5. Experimental study of cooling tower performance using ceramic tile packing

    OpenAIRE

    Ramkumar Ramkrishnan; Ragupathy Arumugam

    2013-01-01

    Deterioration of the packing material is a major problem in cooling towers. In this experimental study ceramic tiles were used as a packing material. The packing material is a long life burnt clay, which is normally used as a roofing material. It prevents a common problem of the cooling tower resulting from corrosion and water quality of the tower. In this study, we investigate the use of three different types of ceramic packings and evaluate their heat and mass transfer coefficients. A simpl...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  8. Method for dimensioning crossflow cooling towers

    International Nuclear Information System (INIS)

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

  9. 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

  10. Dynamic interaction effects in cooling tower groups

    International Nuclear Information System (INIS)

    A theoretical and experimental determination of the dynamic response of reinforced concrete cooling towers, taking into consideration group effects, are described. The results for an individual tower are thoroughly examined. A complete analysis is then performed for the critical wind orientations, for each tower in a six towers group. It's shown that ignoring group effects in the analysis may lead to a significant underestimation of the structural response. (E.G.)

  11. AIRBORNE MONITORING OF COOLING TOWER EFFLUENTS. VOLUME I. TECHNICAL SUMMARY

    Science.gov (United States)

    MRI conducted an airborne plume monitoring program as part of the Chalk Point Cooling Tower Project. Plume measurement included: temperature, dew point, visibility, turbulence, droplet size distribution and concentration, liquid water content, sodium chloride concentration (NaCl)...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-02-01

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

  13. Cooling towers of nuclear power plants

    International Nuclear Information System (INIS)

    The specifications are given of cooling towers of foreign nuclear power plants and a comparison is made with specifications of cooling towers with natural draught in Czechoslovak nuclear power plants. Shortcomings are pointed out in the design of cooling towers of Czechoslovak nuclear power plants which have been derived from conventional power plant design. The main differences are in the adjustment of the towers for winter operation and in the designed spray intensity. The comparison of selected parameters is expressed graphically. (J.B.)

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

    OpenAIRE

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, ...

  15. Numerical simulation of air-cooling tower

    Science.gov (United States)

    Hao, Lijuan; Li, Huanzhi; Sun, Zhaohu; Tong, Lige

    2003-08-01

    A mathematic model for packed air-cooling tower thermodynamic calculation is set up in this paper on the basis of fundamental heat and mass transfer equations. Based on the Double Film theory, direct equation-solving method is used to simulate air-cooling tower, and variation of parameters is taken to analyze the data and results of the program.

  16. Optimization of cooling tower performance analysis using Taguchi method

    OpenAIRE

    Ramkumar Ramakrishnan; Ragupathy Arumugam

    2013-01-01

    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...

  17. 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)

  18. The possibility of the free cooling with cooling towers according to a study of the actual conditions of cooling towers

    International Nuclear Information System (INIS)

    This paper reports that based on the results of a study that was conducted in winter on the state of a combined refrigerating machine and cooling tower refrigeration system in an existing large-scale DHC facility, heat load valuations and the actual performance of the cooling towers were quantitatively obtained, based on which the possibility of free cooling, from which energy savings can be expected, was verified. Based on an analysis of the relationship of the circulating water in the cooling tower during free cooling, to the outlet water temperature and the heat load, it was determined that, during a typical winter period, 850 m3/h of circulating water would be needed to remove a heat load equivalent to the manufacturing heat load from the refrigerating machines. In free cooling with 850 m3/h of circulating water, the outlet water temperature is 8.2 degrees C, or about 1.3 times as high as the outlet water temperature from the refrigerating machines. However, due to lower thermal unit of free cooling, an energy savings of about 60% can be achieved

  19. 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

  20. Optimization of cooling tower performance analysis using Taguchi method

    Directory of Open Access Journals (Sweden)

    Ramkumar Ramakrishnan

    2013-01-01

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

  1. Proceedings: Cooling tower and advanced cooling systems conference

    International Nuclear Information System (INIS)

    This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  2. Experimental study of cooling tower performance using ceramic tile packing

    Directory of Open Access Journals (Sweden)

    Ramkumar Ramkrishnan

    2013-03-01

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

  3. 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

  4. Causes and control of cooling tower film fill deposits

    International Nuclear Information System (INIS)

    Plastic film-type cooling tower fill material is used throughout the utility industry because of its excellent cooling capabilities, compact design, and durability. The remarkable heat rejection of these so-called high efficiency fill materials is due to its ability to form a film of water on a tremendous surface area. For example, hot (80-100 degrees F) recirculating water that is distributed over the cooling tower can be cooled up to 30 degrees with only a 3-4 feet depth of this fill material. By contrast, conventional splash bar cooling tower fill acts by forming droplets can require a volume many times that of film fill to achieve the same drop in cooling water temperature. This paper reports that over the past several years, the utility industry has learned that these high efficiency cooling tower fill materials are subject to fouling, despite the manufacturer or subtle differences in fill design. With certain types of makeup water quality and tower operating practices, it is sometimes impossible to avoid fouling the fill without chemical treatments to control the progression of deposit formation

  5. On thermal performance of seawater cooling towers

    OpenAIRE

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

    2010-01-01

    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...

  6. Wet cooling towers, power plant structures and crosswinds : CFD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Al-Waked, R. [Umow Lai Enginuity Pty Ltd. Consulting Engineers, Sydney, NSW (Australia); Behnia, M. [Sydney Univ., Sydney, NSW (Australia)

    2007-07-01

    The cooling system in large modern thermal power plants includes natural draft wet cooling towers (NDWCT). However, the NDWCTs are not always optimally constructed. Large non-homogeneities of aero- thermodynamic characteristics influence the thermal performance of NDWCTs which affect the operation of thermal power plants in terms of plant efficiency; turbine output; and, additional power capacity. In NDWCTs, a combination of heat and mass transfer effects are used to cool the water coming from the turbine's condenser. As the heat of the water is transferred to the air passing through the tower, the warmed air tends to rise and draws in fresh air at the base of the tower which make the cooling process dependent on crosswinds conditions. The degradation in thermal performance of cooling towers after installation has highlighted the importance of crosswinds. For that reason, this study performed a 3D computational fluid dynamics analysis to investigate the effect of ambient crosswinds on the thermal performance on NDWCTs. The effect of adjacent building structures was also investigated. The performance of the cooling tower was found to be influenced by the size and location of the power plant with respect to the cooling tower. The effect of installing windbreak walls on the thermal performance of NDWCTs surrounded by the power plant structure was therefore examined. It was concluded that crosswinds can increase the outlet water temperature by as much as 2.5 degrees C. It was determined that high wall porosity is needed, particularly in the inside wall of NDWCTs. In general, the thermal performance of the NDWCTs improved with the installation of a windbreak wall around the inlet of the cooling tower. 19 refs., 1 tab., 8 figs.

  7. Enhancing performance of wet cooling towers

    International Nuclear Information System (INIS)

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

  8. Solution and scope of utilization of the cross-stream cooling towers

    International Nuclear Information System (INIS)

    Technical solutions and operational properties of the cross-stream cooling towers as well as the scope of their utilization are presented. The differences within thermodynamic calculations of the cross-stream and counter-stream cooling towers due to the direction of the air flow as well as water flow in sprinkling system are discussed. The assessment of the capital and operational costs of the cross-stream cooling towers is given and compared with the cost of counter-stream cooling towers (utilizing as an example a calculation conducted for the cooling towers of the 720, 1100 and 1400 MW units). (author). 6 refs, 9 figs

  9. MATHEMATICAL MODELING OF EMISSIONS FROM COOLING TOWERS USING COAL GASIFICATION WASTEWATER

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

    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.)

  12. Counter-Flow Cooling Tower Test Cell

    Directory of Open Access Journals (Sweden)

    Dvo?ák Lukáš

    2014-03-01

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

  13. Distribution of Monoclonal Antibody Subgroups and Sequence-Based Types among Legionella pneumophila Serogroup 1 Isolates Derived from Cooling Tower Water, Bathwater, and Soil in Japan

    OpenAIRE

    Amemura-maekawa, Junko; Kikukawa, Kiyomi; Helbig, Ju?rgen H.; Kaneko, Satoko; Suzuki-hashimoto, Atsuko; Furuhata, Katsunori; Chang, Bin; Murai, Miyo; Ichinose, Masayuki; Ohnishi, Makoto; Kura, Fumiaki

    2012-01-01

    Legionella pneumophila serogroup (SG) 1 is the most frequent cause of legionellosis. This study analyzed environmental isolates of L. pneumophila SG 1 in Japan using monoclonal antibody (MAb) typing and sequence-based typing (SBT). Samples were analyzed from bathwater (BW; n = 50), cooling tower water (CT; n = 50), and soil (SO; n = 35). The distribution of MAb types varied by source, with the most prevalent types being Bellingham (42%), Oxford (72%), and OLDA (51%) in BW, CT, and SO, respect...

  14. Response of cooling towers to wind loads

    Directory of Open Access Journals (Sweden)

    G. Murali

    2012-01-01

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

  15. 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

  16. Cooling tower protected against storm borne projectiles

    International Nuclear Information System (INIS)

    The description is given of a cooling tower protected against projectiles carried by storms, which can be used, inter alia, for the cooling facilities of nuclear power stations. It is characterized by its being composed of several closed cooling cells arranged around the periphery of a central opening. Each cell has a cold air intake on the outside, several blowers located inside and a hot air outlet along the inside

  17. 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)

  18. The shape of natural draft cooling towers

    International Nuclear Information System (INIS)

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

  19. Cooling tower windage: a new aspect to environmental assessment

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Ataei, A.; Panjeshahi, M. H.; Gharaie, M.

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  3. 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

  4. Evaluation of treated gasification wastewater as cooling tower makeup

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-04-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Ataei

    2009-01-01

    Full Text Available The present study describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. The design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. The design model incorporated the cooling tower factors to achieve the optimum design. The main factors included: the diameter of the water droplets, the liquid to gas mass ratio, the height of rain zone, packing zone and spray zone, the air and water velocity inside the tower and the frontal area. Once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is modelled within the known design variables. The optimization model is validated against a sample problem. The suggested design algorithms of cooling tower are computed using Visual Studio.Net 2003 (C++.

  6. A systemic approach for optimal cooling tower operation

    International Nuclear Information System (INIS)

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

  7. European dry cooling tower operating experience

    Energy Technology Data Exchange (ETDEWEB)

    DeSteese, J.G.; Simhan, K.

    1976-03-01

    Interviews were held with representatives of major plants and equipment manufacturers to obtain current information on operating experience with dry cooling towers in Europe. The report documents the objectives, background, and organizational details of the study, and presents an itemized account of contacts made to obtain information. Plant selection was based on a merit index involving thermal capacity and length of service. A questionnaire was used to organize operational data, when available, into nine major categories of experience. Information was also solicited concerning the use of codes and standards to ensure the achievement of cooling tower performance. Several plant operators provided finned-tube samples for metallographic analysis. Additionally, information on both operating experience and developing technology was supplied by European technical societies and research establishments. Information obtained from these contacts provides an updated and representative sample of European experience with dry cooling towers, which supplements some of the detailed reviews already available in the literature. In addition, the study presents categorized operating experience with installations which have not been reviewed so extensively, but nevertheless, have significant operational histories when ranked by the merit index. The contacts and interviews reported in the survey occurred between late March and October 1975. The study was motivated by the expressed interest of U.S. utility industry representatives who expect European experience to provide a basis of confidence that dry cooling is a reliable technology, applicable when necessary, to U.S. operating requirements.

  8. Recent developments of cooling tower design

    OpenAIRE

    Harte, Reinhard; Wittek, Udo

    2009-01-01

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

  9. Susceptibility of Legionella pneumophila to three cooling tower microbicides.

    OpenAIRE

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

    1981-01-01

    Investigation of epidemic outbreaks of Legionnaires disease by Center for Disease Control personnel has resulted in the isolation of Legionella pneumophila from water in the air-conditioning cooling towers or evaporative condensers at the site of the outbreak. It is suspected that improperly maintained open, recirculating water systems may play a role in the growth and dissemination of this pathogen. The objective of this study was to determine the antimicrobial activity of three chemically d...

  10. 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)

  11. 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

  12. Corrosion control studies in a mini cooling tower

    International Nuclear Information System (INIS)

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

  13. Investigations of combined used of cooling ponds with cooling towers or spraying systems

    International Nuclear Information System (INIS)

    Based on a brief analysis of the methods of investigating cooling ponds, spraying systems and cooling towers, a conclusion is made that the direct modelling of the combined use of cooling systems listed cannot be realized. An approach to scale modelling of cooling ponds is proposed enabling all problems posed by the combined use of coolers to be solved. Emphasized is the importance of a proper choice of a scheme of including a cooler in a general water circulation system of thermal and nuclear power plants. A sequence of selecting a cooling tower of the type and spraying system of the size ensuring the specified temperature regime in a water circulation system is exemplified by the water system of the Ghorasal thermal power plant in Bangladesh

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

    Directory of Open Access Journals (Sweden)

    Lakovi? Mirjana S.

    2012-01-01

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

  15. Investigation of Natural Draft Cooling Tower Performance Using Neural Network

    Science.gov (United States)

    Mahdi, Qasim S.; Saleh, Saad M.; Khalaf, Basima S.

    In the present work Artificial Neural Network (ANN) technique is used to investigate the performance of Natural Draft Wet Cooling Tower (NDWCT). Many factors are affected the rang, approach, pressure drop, and effectiveness of the cooling tower which are; fill type, water flow rate, air flow rate, inlet water temperature, wet bulb temperature of air, and nozzle hole diameter. Experimental data included the effects of these factors are used to train the network using Back Propagation (BP) algorithm. The network included seven input variables (Twi, hfill, mw, Taiwb, Taidb, vlow, vup) and five output variables (ma, Taowb, Two, ?p, ?) while hidden layer is different for each case. Network results compared with experimental results and good agreement was observed between the experimental and theoretical results.

  16. Preliminary design of dry cooling tower for the closed cycle gas turbine HTGR

    International Nuclear Information System (INIS)

    The effects of air approach velocity, capacity rates of air and water mediums, and number of heat exchanger cross flow passes on tower and heat exchanger dimensions are studied. Optimum tower designs are achieved with three cross flow passes for the heat exchanger, resulting in minimization of tower height, heat exchanger surface area and circulating water pumping power. The 1200 MW(e) plant can be cooled by a single tower design. In comparison, the fossil-fired or HTGR steam plants of the same output need three towers. 16 refs

  17. Study on Characteristics of Special Turbine in Hydrodynamic Cooling Tower

    OpenAIRE

    Li Yanpin; Zhang Lanjin; Chen Dexin

    2012-01-01

    Today a special type of hydraulic turbine is used to replace electromotor to drive the fan in hydrodynamic cooling tower. This is a brand new turbine application. At present, systematic researching about the special turbine has still not been seen. The energy consumption of the electromotor is saved entirely because the power source comes from the surplus energy of circulating water system. But the special turbine works in a series of pressure flow system, its flow characteristic, working cha...

  18. 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

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

    International Nuclear Information System (INIS)

    The shell is for thermal power plants cooling towers having heat exchange surfaces inside the tower. The vertical is such that the hydraulic diameter D in each horizontal section, at a level z above a reference section of which hydraulic diameter is Do is between once and 1.15 time the value given by the formula: Do(1+(2??gz/?Vo2))O,25 + 2?z in which Vo is the vertical flow rate through the reference section; ? is the hot air density; ?? is the density difference of the hot air between the outside and the inside of the shell; ? is an adjustment parameter without dimension of which value is between 0.09 and 0.13. The present invention ensures the cooling tower to operate nearly at the optimum and the construction cost of the shell is reduced

  20. Measurements at cooling tower plumes. Pt. 1

    International Nuclear Information System (INIS)

    Referring to the present status of knowledge model conceptions, assumptions and approaches are summarized, which can lead to mathematical models for the simulation of dry or wet cooling tower plumes. By developing a one-dimensional plume model (FOG) the most important problems are considered in detail. It is shown that for the calibration of the necessary parameters as well as for the development of models full scale measurements are of decisive importance. After a discussion of different possibilities of measurement the organisation of a campaign of measurement is described. (orig.)

  1. 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%

  2. 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

  3. 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

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

    Science.gov (United States)

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

    1997-01-01

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

  5. 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.

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

    International Nuclear Information System (INIS)

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

  7. Development of an improved PCR-ICT hybrid assay for direct detection of Legionellae and Legionella pneumophila from cooling tower water specimens.

    Science.gov (United States)

    Horng, Yu-Tze; Soo, Po-Chi; Shen, Bin-Jon; Hung, Yu-Li; Lo, Kai-Yin; Su, Hsun-Pi; Wei, Jun-Rong; Hsieh, Shang-Chen; Hsueh, Po-Ren; Lai, Hsin-Chih

    2006-06-01

    A novelly improved polymerase chian reaction and immunochromatography test (PCR-ICT) hybrid assay comprising traditional multiplex-nested PCR and ICT, (a lateral-flow device) was developed for direct detection of Legionella bacteria from environmental cooling tower samples. The partial 16S rDNA (specific for Legionella spp.) and dnaJ (specific for Legionella pneumophila) genes from Legionella chromosome were first specifically amplified by multiplex-nested PCR, respectively, followed by detection using ICT strip. Reading of results was based on presence or absence of the two test lines on the strips. Presence of test line 1 indicated existence of Legionella spp. specific 16S rDNA and identified Legionella spp. Presence of test line 2 further indicated existence of dnaJ and thus specifically identified L. pneumophila. In contrast, for non-Legionellae bacteria no test line formation was observed. Results of direct detection of Legionella bacteria and L. pneumophila from water tower specimens by this assay showed 100% sensitivity, and 96.6% and 100% specificity, respectively compared with traditional culture, biochemical and serological identification methods. The PCR-ICT hybrid assay does not require sophisticated equipment and was proved to be practically useful in rapid and direct Legionellae detection from environmental water samples. PMID:16713613

  8. 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

  9. Results from the EPRI cooling tower performance prediction and improvement project

    International Nuclear Information System (INIS)

    A project aimed at providing tools to the utility engineer for prediction of cooling tower thermal performance is reviewed. Project deliverables, being prepared for publication, will include data sets on the thermal performance of a variety of commercial cooling tower packings, graphical methods and computer codes to predict utility tower performance from these data, and full-scale tower performance data used to validate the predictive tools. A guide to assist in the application of these techniques to technical bid evaluations, study of backfit options, and design of tower testing programs is outlined. Plans for expansion of the project scope are discussed. This scope expansion includes a study of factors that degrade tower performance (fill degradation, icing, wind effects, and nonideal fan performance) and development of methods to mitigate these factors. In addition, development of more accurate methods to measure air and water flow rates at large scale, necessary to determine tower thermal performance more accurately, are included in the plan

  10. 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

  11. A study of the life expectancy of cooling towers

    International Nuclear Information System (INIS)

    The paper describes the following different tasks of the study whose aim was to extend the life time of cooling towers for French Nuclear Power plants to 40 years. The aging factors specific to cooling towers were measured and analysed with regard to the external surface, the internal surface and inside the concrete. The safety coefficient for buckling was calculated and then the stress analysis of the materials (concrete and steel) was done. A special computer program written for cooling towers was used with a model including the soil stiffness and the supports of the tower. (author)

  12. Environmental impact of cooling towers of large nuclear power plants

    International Nuclear Information System (INIS)

    The computer program for the calculation of the 3-dimensional rise of cooling tower plumes was examined on the basis of the measurements at Neurath. The program MEDINT developed by the department 'Datenverarbeitung und Instrumentierung' allows now the calculation of the distribution of different parameters in any cross-section of the cooling tower plume, which are needed for the tests. (orig.)

  13. Improving performance and reducing costs of cooling towers

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  15. Water Tower Challenge

    Science.gov (United States)

    IEEE

    2014-05-23

    In this activity, learners explore how engineers work to solve the challenges of a society, such as delivering safe drinking water. Learners work in teams to devise a system using everyday materials that can deliver water in a controlled manner to a paper cup that is about 36 inches or 90 cm away. Learners sketch their plans, build their system, test it, and reflect on the challenge.

  16. Basic conceptions for development of new-type high-efficiency cooling towers with enhanced reliability, maneuverability and maintainability

    International Nuclear Information System (INIS)

    The state-of-the-art of cooling tower design, construction and operation is analysed. From the analysis formulated are general requirements which can be imposed upon cooling towers serving as most important technological apparatuses in water supply systems of thermal and nuclear power plants. With these requirements taken into account, basic research and technical conceptions are developed to be used in designing new-type cooling towers characterized by enhanced reliability, maneuverability and maintainability

  17. Design of a water tower in steel

    OpenAIRE

    Nicolaou, Irini

    1994-01-01

    The main objective of this project is t? design a Water Tower in Steel for potable water. The Water Tower will be constructed to act as a water reservoir, in a water supply system. The size of the tank depends on the capacity of water to be stored. The cost of Water Tower depends mainly on its shape and on the type of structural material that is going to be used. In this project the Water Tower is made of Mild Steel, Grade 43. The choice of the shape was done, taking into account the d...

  18. Observed and predicted cooling tower plume rise at the John E. Amos Power Plant, West Virginia

    International Nuclear Information System (INIS)

    There is much current interest in cooling tower plume rise because of its importance in determining the environmental impact of cooling towers at planned power plants and industrial facilities. Some of the possible environmental problems related to heat and water emissions from cooling towers are drift deposition, ground level fog, cloud formation, and precipitation enhancement. An important factor in all of these problems is the calculation of the plume trajectory, which is often complicated by the presence of multiple sources and water phase changes in the plume. The latent heat does not strongly influence plume rise if there is no cloud present at the top of the plume. A one dimensional plume and cloud growth model was developed to study these effects. In this paper, the predictions of the model are compared with observations of cooling tower plume rise at the John E. Amos, W. Va. fossil-fuel power plant

  19. 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

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

    OpenAIRE

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

    2010-01-01

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

  1. Fire behaviour of cooling tower packing; Brandverhalten von Kuehlturmeinbauten

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

    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.)

  2. Experimental investigation of the hydraulic characteristics of a counter flow wet cooling tower

    International Nuclear Information System (INIS)

    Thermal and nuclear electric power plants as well as several industrial processes invariably discharge considerable energy to their surrounding by heat transfer. Although water drawn from a nearby river or lake can be employed to carry away this energy, cooling towers offer an excellent alternative particularly in locations where sufficient cooling water cannot be easily obtained from natural sources or where concern for the environment imposes some limits on the temperature at which cooling water can be returned to the surrounding. This paper concerns an experimental investigation of the hydraulic characteristics of a counter flow wet cooling tower. The tower contains a 'VGA.' (Vertical Grid Apparatus) type packing which 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. The present investigation is focused mainly on the effect of the air and water flow rates on the hydraulic characteristics of the cooling tower, for different inlet water temperatures. The two hydrodynamic operating regimes which were observed during the air/water contact operation within the tower, namely the Pellicular Regime (PR) and the Bubble and Dispersion Regime (BDR) have enabled to distinguish two different states of pressure drop characteristics. The first regime is characterized by low pressure drop values, while in the second regime, the pressure drop values are relatively much higher than those observed in the first one. The dependence between the pressure drop characteristics and the combined heat and mass transport (air-water) through the packing inside the cooling tower is also highlighted. The obtained results indicate that this type of tower possesses relatively good hydraulic characteristics. This leads to the saving of energy. -- Highlights: ? Cooling towers are widely used to reject waste heat from thermal and nuclear electric power plants to the atmosphere. ? The hydraulic characteristics of a counter flow wet cooling tower have been studied experimentally. ? The effect of the air and water flow rates on the hydraulic characteristics of tower was investigated. ? Different inlet water temperatures: 35 oC, 43 oC and 50 oC, respectivelly, were used in the investigation. ? The results indicate that this type of tower possesses relatively good hydraulic characteristics.

  3. On the possibility of a ''dry'' cooling tower application for the APS condensators with a dissociating coolant

    International Nuclear Information System (INIS)

    Calculations have been carried out for a Geller cooling tower of a 1000 MW nuclear power plant aimed at investigating the possibility of using ''dry'' cooling towers to cool condensers of nuclear power plants with N2O4 as coolant, and at estimating specific charges on the process water supply system. Taking into consideration commercialy produced equipment, air condenser plants are assumed to operate with an ordinary surface condenser. The main dimensional and cost parameters of a ''dry'' cooling tower for a thermal cycle version with the maximum temperature of 450 deg C are calculated using the Transelectro (Hungary) nomograms for average annual air temperature. The calculation results show the Geller cooling towers for 1000 MW nuclear power plants to be economically competitive with evaporating cooling towers; and more; besides, is this case atmosphere pollution is avoided and water flow rate for making-up the water supply system is reduced

  4. Safety analysis for K reactor and impact of cooling tower installation

    International Nuclear Information System (INIS)

    This paper describes the safety analysis of the Savannah River site K-reactor loss-of-cooling-water-supply (LOCWS) event and the impact on the analysis of a natural-draft cooling tower, which was installed in 1992. Historically (1954 to 1992), the K-reactor secondary cooling system [called the cooling water system (CWS)] used water from the Savannah River pumped to a 25-million-gal basin adjacent to the reactor. Approximately 170 000 gal/min were pumped from the basin through heat exchangers to remove heat from the primary cooling system. This water then entered a smaller basin, where it flowed over a weir and eventually returned to the Savannah River. The 25-million-gal basin is at a higher elevation than the heat exchangers and the smaller basin to supply cooling by gravity flow (which is sufficient to remove decay heat) if power to the CWS pumps is interrupted. Small amounts of cooling water are also used for other essential equipment such as diesels, motors, and oil coolers. With the cooling tower installed, ?85% of the cooling water flows from the small basin by gravity to the cooling tower instead of returning to the Savannah River. After being cooled, it is pumped back to the 25-million-gal basin. River water is supplied only to make up for evaporation and the blowdown stream

  5. Dynamic behavior and identification of failure modes of cooling towers

    International Nuclear Information System (INIS)

    The major thrust of this paper is to provide an engineering assessment of two hyperboloidal 540-foot high reinforced concrete cooling towers at a nuclear power plant relative to the proposed construction of a new safety-related facility in the shadow of these cooling towers. A three-dimensional full 360-degree finite-element model that is capable of realistically representing the response of the two cooling towers subjected to the plant design-basis safe shutdown earthquake, 90 mph wind, and 300 mph tornado is used to create a data pool which supports the proposed construction of the new facility. Dynamic time history analyses are performed to represent the complex interplay of the dynamic characteristics of the cooling towers and the input wind-pressure excitation in terms of gust factors. This study resulted in the confirmation and enhancement of many of the important aspects in the design/analysis methodologies for cooling towers reported in literature. In summary, this study provides a high confidence that no significant damage will be caused to the two cooling towers when subjected to the plant design-basis safe shutdown earthquake and the 90 mph basic wind velocity. However, the two cooling towers are expected to collapse if subjected in a direct hit to a 300 mph tornado. The nonlinear finite element analyses including base uplift performed for this study and the literature research on past failures of cooling towers due to severe wind storms confirm that the mo to severe wind storms confirm that the mode of failure will not be the overturning cantilever tree-type and the towers will collapse inwardly with the exception of few isolated debris

  6. Numerical simulation of a cooling tower coupled with heat pump system associated with single house using TRNSYS

    International Nuclear Information System (INIS)

    Highlights: • We simulate a cooling tower coupled with heat pump system and a single zone using TRNSYS. • We examine the temperature of water inside the cooling tower and inside the single zone. • We study the temporal evolution of the all parameters for 4500 h operation in winter in Tunisia. - Abstract: The industrial cooling towers in Tunisia meet difficulties due to the poor coordination between the utility and process sectors. In this study, we will consider especially the vapor recovery of the wastewater from the industrial activity in south Tunisia. By using the heat pump for high capacity, the problem for vapor from wastewater may be resolved. The coupling for the cooling tower and the heat pump system is investigated by TRNSYS software. The system of cooling tower is also associated with a single zone which is related to heat exchangers. An optimization model for the operation of a cooling water system was developed that accounts for a cooling tower, and a network of pipelines and heat exchangers for heating a single house. This work is based on numerical studies; the cooling tower performance, the single house, the heat pump and the heat exchanger that are simulated using TRNSYS model. The circulation of cooling water system is assured by a counter flow. The evaluations of the cooling tower geometry and performances are based on an adaptive version of Merkel’s method witch integrated in TRNSYS. The results of optimization using TRNSYS are validated by several theoretical and experimental studies

  7. Work of the condensation unit of NPP with evaporative cooling tower

    International Nuclear Information System (INIS)

    The analysis of cooling system work of power unit of NPP consisting from a condenser of turbine and with the area of an irrigation 10 000 m2 is presented. Productivity of the evaporative cooling tower and the overall efficiency of condenser, effecting on power characteristics of NPP are defined. Influence of external conditions during a year cycle on parameters of the power unit of NPP is considered. Tabular and graphic dependences of cooling water temperature changes in cooling tower, temperatures and pressure of the condensation are received. (authors).

  8. Experimental investigation of the performance characteristics of a counterflow wet cooling tower

    International Nuclear Information System (INIS)

    An experimental investigation of the performance characteristics of a counter flow wet cooling tower represented by the heat rejected by the tower and its thermal effectiveness is presented in this paper. The tower is filled with a 'VGA.' (Vertical Grid Apparatus) type packing which is 0.42 m high and contains four (04) galvanized 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 - 0.148 m. The investigation is concerned mainly on the effect of the air, water flow rates and the inlet water temperatures on the thermal effectiveness of the cooling tower as well as the heat rejected by this tower from water to be cooled to the air stream discharged into the atmosphere. The two operating regimes which were observed during the air/water contact inside the tower, a Pellicular Regime (PR) and a Bubble and Dispersion Regime (BDR) appear to be important, as The BDR regime enables to cool larger amount of water flow rates, while the Pellicular regime results with higher thermal effectiveness. (authors)

  9. Stimulatory effect of cooling tower biocides on amoebae.

    OpenAIRE

    Srikanth, S.; Berk, S. G.

    1993-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-01-15

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

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

    International Nuclear Information System (INIS)

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

  12. A model for seasonal and annual cooling tower impacts

    Science.gov (United States)

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

    The Argonne National Laboratory/University of Illinois Seasonal/Annual Cooling Tower Impacts model provides predictions of seasonal, monthly, and annual cooling tower impacts from any number of mechanical- or natural-draft cooling towers. The model typically requires five years of hourly surface meteorological data and concurrent twice-daily mixing heights in addition to basic data on the thermal performance of the cooling tower. The model predicts average plume length, rise, drift deposition, fogging, icing, and shadowing. The model uses a category scheme in which the five years of hourly surface data are placed into about 100 categories based on a special plume-scalling relationship. With this reduced number of cases to be run for long-term impact evaluations, advanced state-of-the-art models for plume impacts are then applied. For multiple plumes, the methodology includes variation of the merging patterns and of the wake effects from tower housings for different wind directions. The main advantage to this model over previous models is its advanced theoretical development and extensive model validation with experimental data for its component submodels. From studies in the United States of America and Europe, an extensive database on cooling tower plumes and drift was accumulated and analysed to assist in the identification of superior theoretical assumptions. Other data, not used in model development, provided for independent model verification. The validation of each submodel is presented, and typical results are given for a representative natural-draft cooling tower installation and for a typical linear mechanical-draft cooling tower arrangement.

  13. High Flux Isotopes Reactor (HFIR) Cooling Towers Demolition Waste Management

    International Nuclear Information System (INIS)

    This paper describes the results of a joint initiative between Oak Ridge National Laboratory, operated by UT-Battelle, and Bechtel Jacobs Company, LLC (BJC) to characterize, package, transport, treat, and dispose of demolition waste from the High Flux Isotope Reactor (HFIR), Cooling Tower. The demolition and removal of waste from the site was the first critical step in the planned HFIR beryllium reflector replacement outage scheduled. The outage was scheduled to last a maximum of six months. Demolition and removal of the waste was critical because a new tower was to be constructed over the old concrete water basin. A detailed sampling and analysis plan was developed to characterize the hazardous and radiological constituents of the components of the Cooling Tower. Analyses were performed for Resource Conservation and Recovery Act (RCRA) heavy metals and semi-volatile constituents as defined by 40 CFR 261 and radiological parameters including gross alpha, gross beta, gross gamma, alpha-emitting isotopes and beta-emitting isotopes. Analysis of metals and semi-volatile constituents indicated no exceedances of regulatory limits. Analysis of radionuclides identified uranium and thorium and associated daughters. In addition 60Co, 99Tc, 226Rm, and 228Rm were identified. Most of the tower materials were determined to be low level radioactive waste. A small quantity was determined not to be radioactive, or could be decontaminated. The tower was dismantled October 2000 to Januatower was dismantled October 2000 to January 2001 using a detailed step-by-step process to aid waste segregation and container loading. The volume of waste as packaged for treatment was approximately 1982 cubic meters (70,000 cubic feet). This volume was comprised of plastic (?47%), wood (?38%) and asbestos transite (?14%). The remaining ?1% consisted of the fire protection piping (contaminated with lead-based paint) and incidental metal from conduit, nails and braces/supports, and sludge from the basin. The waste, except for the asbestos, was volume reduced via a private contract mechanism established by BJC. After volume reduction, the waste was packaged for rail shipment. This large waste management project successfully met cost and schedule goals

  14. Evaluation of the RSG-GAS cooling tower performance

    International Nuclear Information System (INIS)

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

  15. 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%

  16. Alternative geometry for cylindrical natural draft cooling tower with higher cooling efficiency under crosswind condition

    International Nuclear Information System (INIS)

    Highlights: • Alternative cross sections for natural draft cooling tower were proposed. • Numerical solution was applied to study thermal and hydraulic performances. • Thermal and hydraulic performances were assessed by comparative parameters. • Cooling tower with elliptical cross section had better thermal performance under crosswind. • It could successfully used at the regions with invariant wind direction. - Abstract: Cooling efficiency of a natural draft dry cooling tower may significantly decrease under crosswind condition. Therefore, many researchers attempted to improve the cooling efficiency under this condition by using structural or mechanical facilities. In this article, alternative shell geometry with elliptical cross section is proposed for this type of cooling tower instead of usual shell geometry with circular cross section. Thermal performance and cooling efficiency of the two types of cooling towers are numerically investigated. Numerical simulations show that cooling tower with elliptical cross section improves the cooling efficiency compared to the usual type with circular cross section under high-speed wind moving normal to the longitudinal diameter of the elliptical cooling tower

  17. Statistical multi-model approach for performance assessment of cooling tower

    International Nuclear Information System (INIS)

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

  18. Atmospheric wet-type cooling tower with antifreeze system

    International Nuclear Information System (INIS)

    The cooling tower has air inlets at its base, a network of pipes which distributes the air to be cooled above the packing, and valves to isolate a part of the network. It includes also a bypass circuit, provided with means to control the flow rate fraction which is by-passed

  19. 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

  20. Short-term pilot cooling tower tests

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-01-01

    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.

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

    International Nuclear Information System (INIS)

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

  2. 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

  3. Influence of wind on conditions of plumes at natural draft cooling towers

    International Nuclear Information System (INIS)

    It was the objective of this research project, to establish the influence of wind on the emission characteristics, the plume data at the top of cooling towers and on the dispersion of plumes in free atmosphere. Data from field-measurements on a natural draft wet cooling-tower were analyzed systematically, a model for the calculation of the plume characteristics was further developed, and the plume dispersion under different conditions was investigated by a model computation. Plume velocity and cooling air massflow show a minimum at a wind speed around 4 m/s. Their depression in this area of wind speed leads to an increase of the cold water temperature of the cooling tower and hence to a loss of power station efficiency. Temperature and humidity of plume have a maximum value in this area. Halving of wind velocity leads to doubling of the cross section area in the symmetry plane of the plume. (orig./HP)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-02

    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.

  5. Mistral: New test bench for cooling tower components

    International Nuclear Information System (INIS)

    The use of the test bench for cooling tower components of Nantes-Chevire, useful counterflow cross-section: 7m x 7m, has shown the adequacy of this large tool for the study of large equipment and the elimination of the boundary effect (boundary effect coefficient between 1.2 and 1.5). After having decommissioned this bench, Electricite de France built the Mistral bench at the Nuclear Generation Centre of Bugey. It is equipped with two test systems. The cross-section of the counterflow system is 7m x 7m and its useful height, 3.5m. The cross-section of the cross-flow system is 5 x 10m and its depth 10m. Water and air flows can reach respectively 600 1 per sec. and 225m3 per sec. for a maximum thermal capacity of 25 MW

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

    OpenAIRE

    Andi Yasmon; Yusmaniar Yusmaniar; Anis Anis; Budiman Bela

    2010-01-01

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

  7. Modeling of hydronic radiant cooling of a thermally homeostatic building using a parametric cooling tower

    International Nuclear Information System (INIS)

    Highlights: • Investigated cooling of thermally homeostatic buildings in 7 U.S. cities by modeling. • Natural energy is harnessed by cooling tower to extract heat for building cooling. • Systematically studied possibility and conditions of using cooling tower in buildings. • Diurnal ambient temperature amplitude is taken into account in cooling tower cooling. • Homeostatic building cooling is possible in locations with large ambient T amplitude. - Abstract: A case is made that while it is important to mitigate dissipative losses associated with heat dissipation and mechanical/electrical resistance for engineering efficiency gain, the “architect” of energy efficiency is the conception of best heat extraction frameworks—which determine the realm of possible efficiency. This precept is applied to building energy efficiency here. Following a proposed process assumption-based design method, which was used for determining the required thermal qualities of building thermal autonomy, this paper continues this line of investigation and applies heat extraction approach investigating the extent of building partial homeostasis and the possibility of full homeostasis by using cooling tower in one summer in seven selected U.S. cities. Cooling tower heat extraction is applied parametrically to hydronically activated radiant-surfaces model-buildings. Instead of sizing equipment as a function of design peak hourly temperature as it is done in heat balance design-approach of selecting HVAC equipment, it is shown that the conditions of using cooling tower depend on both “design-peak” daily-mean temperature and the distribution of diurnal range in hourly temperature (i.e., diurnal temperature amplitude). Our study indicates that homeostatic building with natural cooling (by cooling tower alone) is possible only in locations of special meso-scale climatic condition such as Sacramento, CA. In other locations the use of cooling tower alone can only achieve homeostasis partially

  8. 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

  9. Design of cooling towers by the effectiveness-NTU method

    International Nuclear Information System (INIS)

    This paper develops the effectiveness-NTU, number of transfer units, design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat transfer design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A one-increment design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NYU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard Log-Mean Enthalpy Method (LMED) or effectiveness-NTU design methods to design cooling towers

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

    International Nuclear Information System (INIS)

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

  11. 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

  12. Discussion on NPP cooling tower's load value according to British BS, German BTR and Chinese codes

    International Nuclear Information System (INIS)

    Design of nuclear power plant cooling tower is a new task for NPP CI design. Requirements on NPP safety and utilization are different from those on common fossil-fired power plants and the design of cooling tower is an important aspect. Specifications on values of cooling tower design load in British BS, German BTR and Chinese codes (on hydraulic structures) are analyzed and compared. A few significant conclusions reached are helpful reference for NPP cooling tower design. (authors)

  13. 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)

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

    Science.gov (United States)

    Banooni, Salem; Chitsazan, Ali

    2014-05-01

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

  15. Operational cost minimization in cooling water systems

    OpenAIRE

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

    2000-01-01

    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 const...

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

    International Nuclear Information System (INIS)

    Big Three Industries, a manufacturer of compressed and liquefied atmospheric gases, operates a large production complex in Bayport, TX which recirculates 100,000 gpm cooling water. Due to regulatory agency guidelines, high costs, and limited effectiveness of conventional chemical treatment methods, Big Three was in need of a treatment method to prevent corrosion and scaling in recirculating water cooling systems. In December 1983 a magnetic fluid conditioner (MFC) was installed in the pump discharge piping of one cooling tower at Bayport. The patented MFC is an 18'' long spool pipe fitted with uranium-based alloy magnets. The MFC has no moving parts and requires no chemicals, external power source, or maintenance. The MFC is designed so that the fluid is accelerated through a magnetic field. The high velocity of the fluid causes nucleation of the salts in the fluid. The salts are separated from the water by precipitation. During eighteen months of using the MFC, the cooling tower has concentrated in excess of 50 cycles. Conductivity is in excess of 10,000 micromhos, and total hardness (CaCO3) is above 4000 ppm with pH stabilized between 8 and 9. However, inspections have revealed clean surfaces. The cleaner metal surfaces within the cooling water system provide better heat transfer which has resulted in reduction of tower blowdown, makeup water requirements, and pumping costs. Associated savings will enable the MFC to achieve payback in two and a half years

  17. Recent developments in the design of large cooling towers

    International Nuclear Information System (INIS)

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

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-01

    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.

  20. 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)

  1. 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

  2. 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

  3. Study on Characteristics of Special Turbine in Hydrodynamic Cooling Tower

    Directory of Open Access Journals (Sweden)

    Li Yanpin

    2012-11-01

    Full Text Available Today a special type of hydraulic turbine is used to replace electromotor to drive the fan in hydrodynamic cooling tower. This is a brand new turbine application. At present, systematic researching about the special turbine has still not been seen. The energy consumption of the electromotor is saved entirely because the power source comes from the surplus energy of circulating water system. But the special turbine works in a series of pressure flow system, its flow characteristic, working characteristics and regulative characteristics different from conventional power turbine. This study introduces the theory analysis and experimental study on these characteristics. The research shows that special turbine has more complex flow characteristics and the turbine-fan unit has good self-adaptive characteristics and regulative characteristics. When the turbine is not in its optimal condition we can regulate it to a proper condition by adjusting the guide glade and the angle of the fan's vane or replacing the diameter of fan. These are never been found.

  4. A numerical study of interacting buoyant cooling-tower plumes

    Energy Technology Data Exchange (ETDEWEB)

    Bornoff, R.B.; Mokhtarzadeh-Dehghan, M.R. [Brunel Univ., Uxbridge (United Kingdom). Dept. of Mechanical Engineering

    2001-07-01

    The compact design of mechanical cooling towers necessitates that the plumes are issued into the cross-wind in close proximity. An improved understanding of the interaction of adjacent plumes is therefore required for better design of such cooling towers, which may lead to a reduction in their environmental impact. This paper presents the results of a numerical investigation into the interaction of two adjacent plumes in a cross-flow. The numerical model simulates small-scale wind tunnel experiments of a cooling tower arrangement. The computations are performed for three-dimensional, turbulent, buoyant and interacting plumes, and for a single plume for comparison. Two double-source arrangements, namely, tandem and side-by-side, with respect to the oncoming atmospheric boundary layer are considered. A low Reynolds number k-{epsilon} turbulence model is used with two discretisation schemes, hybrid and QUICK, and the results are compared. Comparisons are also made with the experimental results. The results show that the interaction of side-by-side plumes is dominated by the interaction of the rotating vortex pairs within the plumes. A tandem source arrangement leads to early merging and efficient rise enhancement. Comparisons of the predicted results with experimental data show good agreement for the plume rise. (Author)

  5. 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)

  6. Numerical research of a super-large cooling tower subjected to accidental loads

    International Nuclear Information System (INIS)

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion

  7. Numerical research of a super-large cooling tower subjected to accidental loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Lin, Feng [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Gu, Xianglin, E-mail: gxl@tongji.edu.cn [Department of Building Engineering, Tongji University, Shanghai 200092 (China); Lu, Xiaoqin [Guangdong Electric Power Design Institute, Guangzhou 510660 (China)

    2014-04-01

    With the continued development of nuclear power plants, more and more super-large cooling towers are to be built in China and around the world. For the safe operation of nuclear power plants, research work has been done on the causes of collapse of cooling towers, collapse modes and the secondary disasters caused by the collapse of cooling towers. However, the collapse modes and the ground vibration induced by the collapse of cooling towers subjected to the accidental loads have not been fully understood. This paper has been focused on the modes and mechanisms behavior of the collapse of cooling towers subjected to accidental loads. Meanwhile, prediction of the ground vibration due to the collapse of the cooling towers has also been completed in a parallel project. Using dynamic finite element program LS-DYNA, a 3D finite element model for a super-large cooling tower was developed and the nonlinear material models were incorporated. In this paper, four types of accidental loads were considered to trigger the collapse or local failure of the tower, including vehicle collision, airplane impact, local explosion and missile attack. It was found that vehicle collision, missile attack and small TNT equivalent explosives (2 kg, 20 kg, 200 kg) might result in local failure of the cooling tower, however, the tower can still keep stable. On the other hand, large TNT equivalent explosives (2000 kg, 4500 kg) could cause severe damages in the inclined columns of the cooling tower, and lead to progressive collapse of the entire cooling tower. The two kinds of TNT equivalent explosives caused the same collapse mode while the collapsing duration was different. The airplane impacted at the throat of the cooling tower caused the local failure of shell structure of the tower, and then the progressive collapse of the cooling tower happened due to the gravitational action. The resulting collapse mode was different from that triggered by the local explosion.

  8. Assessing acceptance tests at wet type cooling towers; Zur Beurteilung von Abnahmeversuchen an Nasskuehltuermen

    Energy Technology Data Exchange (ETDEWEB)

    Wernicke, D.

    1999-07-01

    With this new numeric procedure for assessing acceptance tests presented here, the overall thermal guarantee 'cold water temperature' is looked at as an interaction of operating conditions and parameters which can be influenced by constructive means. By a consequent application of heat and mass transfer theory on the evaporation processes inside the cooling tower it is possible to trace the overall thermal guarantee back to clearly distinguishable partial guarantees 'transfer area' and 'air flow rate'. The new procedure is not bound to a unique cooling tower but is rather comprehensively applicable to counter-flow wet type cooling towers. It is therefore an appropriate alternative to the method of assessing cooling tower acceptance tests to DIN 1947. (orig.) [German] Mit diesem neuen numerischen Verfahren der Abnahmebeurteilung wird die thermische Gesamtgarantie 'Kaltwassertemperatur' als Zusammenspiel der Betriebsbedingungen sowie konstruktiv beeinflussbarer Parameter begriffen. Durch konsequente Anwendung der Theorie der Waerme- und Stoffuebertragung auf die Verdunstungsvorgaenge im Kuehlturm gelingt es, die thermische Gesamtgarantie durch die Einfuehrung eines Geometriefaktors CKT auf klar unterscheidbare Teilgarantien Austauschflaeche und Luftdurchsatz zurueckzufuehren. Das neue Verfahren ist nicht an einen speziellen Kuehlturm gebunden, sondern laesst sich uebergreifend auf Gegenstrom-Nasskuehltuerme anwenden. Es bietet daher eine gute Alternative zur Methodik der Auswertung von Abnahmeversuchen an Nasskuehltuermen nach DIN 1947. (orig.)

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

    International Nuclear Information System (INIS)

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

  10. Modeling of heat transfer in cooling towers with natural convection.

    Czech Academy of Sciences Publication Activity Database

    Zuniga-Gonzalez, Israel; Maršík, František

    Gdansk : IFFM Publishers, 2005 - (Mikielewicz, J.; Butrymowicz, D.; Trela, M.; Cie?li?ski, J.), s. 585-592 ISBN 83-88237-90-X. [ HEAT 2005 : International Conference on Transport Phenomena in Multiphase Systems. Gdansk (PL), 26.06.2005-30.06.2005] R&D Projects: GA ?R GA101/02/0364; GA ?R(CZ) GA101/05/2536 Institutional research plan: CEZ:AV0Z20760514 Keywords : cooling tower * heat transfer * evaporative cooling Subject RIV: BK - Fluid Dynamics

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  13. 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

  14. Operational cost minimization in cooling water systems

    Directory of Open Access Journals (Sweden)

    Castro M.M.

    2000-01-01

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

  15. Operational cost minimization in cooling water systems

    Scientific Electronic Library Online (English)

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

    2000-12-01

    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.

  16. Advanced wet-dry cooling tower concept cross-flow tests

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, T.; Bentley, J.; Giebler, M.; Glicksman, L.R.; Rohsenow, W.M.

    1977-01-01

    The design, operation, instrumentation, and performance testing of a crossflow evaporative cooling tower are discussed, and computer predictions for performance are compared with test data. Experimental results for 14 runs agreed with heat and mass transfer coefficient calculations within 5% for 11 runs and within 8% for the remaining 3 runs. It was concluded that the computer model is valid for use in future design studies, that the wet-dry packing is effective in reducing cooling water consumption, and that the crossflow air-water arrangement shows much promise for future development. (LCL)

  17. Local precipitation increases caused by scavenging of cooling tower plumes

    International Nuclear Information System (INIS)

    Quantitative estimates are provided of the precipitation increase in the vicinity of wet cooling towers as a result of plume-droplet scavenging by natural rain. Rain rates from 1 to 5 mm/hr and wind speeds of 1 to 10 m/s are considered with source strength equal to moisture flux from a 1000-MW(e) power capacity. The increase in precipitation strongly depends on distance from the tower, wind speed, natural precipitation rate, source strength, and horizontal angle of plume spread. Under favorable conditions of light winds and steady rainfall, precipitation increases due to scavenging up to about 25 percent of the natural rate should occur as far as 1 km from plants as small as 1000 MW

  18. Rainfall enhancement due to scavenging of cooling tower condensate

    International Nuclear Information System (INIS)

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

  19. 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)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  2. Numerical simulation of shower cooling tower based on artificial neural network

    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. The cooling tower analyzed in this study is void of fill, named shower cooling tower (SCT). However, the present study focuses mostly on experimental investigation of the SCT, and no systematic numerical method is available. In this paper, we first developed a one dimensional model and analyzed the heat and mass transfer processes of the SCT; then we used the concept of artificial neural network (ANN) to propose a computer design tool that can help the designer evaluate the outlet water temperature from a given set of experimentally obtained data. For comparison purposes and accurate evaluation of the predictions, part of the experimental data was used to train the neural network and the remainder to test the model. The results predicted by the ANN model were compared with those of the standard model and the experimental data. The ANN model predicted the outlet water temperature with a MAE (mean absolute error) of 1.31%, whereas the standard one dimensional model showed a MAE of 9.42%

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

    International Nuclear Information System (INIS)

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

  4. Seismic response analysis of column supported natural draught cooling tower shells

    International Nuclear Information System (INIS)

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

  5. 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.)

  6. The Merkel equation revisited: A novel method to compute the packed height of a cooling tower

    International Nuclear Information System (INIS)

    Highlights: ? A relationship between packed height and excess air flow rate is derived. ? The relationship is independent of tower diameter and water flow rate. ? It is well approximated by a power law curve for industrially relevant cases. ? An algorithm to compute the thermodynamic minimum air flow rate is detailed. ? Computation of the packed height is simplified especially for design-optimization. - Abstract: In this work, a new methodology of analysis and computation is presented which simplifies calculation of the packed height in a counter current cooling tower, especially for design and cost optimization studies. An algorithm is presented with an implementation in MATLAB to compute the thermodynamic minimum air flow rate for the desired cooling. Combining the Merkel equation and a standard empirical mass transfer correlation, the packed height is shown to be independent of the water flow rate and tower diameter, and dependent only on the excess air flow. The relationship is unique for a given cooling range of water and inlet air wet bulb temperature. A simple power law regression is used to approximate this relationship and results are presented for Vertical Corrugated Packing.

  7. Physical quantities related to measurement campaigns for cooling towers

    International Nuclear Information System (INIS)

    The nomenclature in reports on the measurement campaigns for cooling towers will be adapted as far as possible to the already existing VDI report on this subject. On the other hand, the appropriate standards will also be accounted for. In order to facilitate a decision in individual cases in a first table the meteorologically or generally interesting quantities of the VDI reports are compared with the German, international, and WMO standards and - if necessary - also commented. A second table contains the air humidity parameters standardized by WMO including brief definitions. (orig/HP)

  8. Wind pressure distribution in a hyperbolic cooling tower

    International Nuclear Information System (INIS)

    Results of a wind tunnel study of the wind pressure distribution on a hyperbolic cooling tower 133m high and base diameter of 122m are prese nted. Measurements of wind pressure were made at 16 external and 8 internal levels. The base columns as well as the heat exchangers were reproduced in the model. The heat exchanger caused a small alteration on the overall distribution of the external and internal pressures, with the exception of the region on the wake near the shell bottom where the internal suction was substantially smaller in the model without heat exchanger. (Author)

  9. Studies of the environmental impact of evaporative cooling tower plumes

    International Nuclear Information System (INIS)

    This ongoing research program of the environmental impact of natural-draft evaporative cooling tower plumes consists principally of a comprehensive series of airborne measurements of a variety of the physical characteristics of the plumes and, to a lesser extent, of preliminary studies of remote sodar plume probing techniques and the development of simplified dynamical numerical models suitable for use in conducting field measurement programs. The PSU Doppler sodar was used at the Keystone Power Plant in southwestern Pennsylvania for an extended series of remote measurements of the characteristics of plume turbulent temperature and velocity fluctuations and results are discussed

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  12. Water-Powered Astronomical Clock Tower

    Science.gov (United States)

    Sun, Xiaochun

    The construction of water-powered astronomical instruments was a long tradition of instrument making that started in the second century AD with Zhang Heng's water-powered celestial globe. The technology reached a peak when, in the eleventh century, Su Song and his team constructed the Water-Powered Astronomical Clock Tower which combined the armillary sphere, the celestial globe, and the time-keeping mechanism into a large automatic structure. Su Song's instrument contained a mechanism for controlling the water-powered movements of its wheels that amounts to an "escapement mechanism" for a mechanical clock. A new reconstruction of the mechanism is introduced in this chapter.

  13. Heat rejection enhancement in natural draft cooling tower using radiator-type windbreakers

    International Nuclear Information System (INIS)

    Highlights: • Radiator-type windbreakers are more efficient than solid types. • They can improve cooling efficiency by three times of solid types. • Radiator-type windbreakers are efficient even at normal condition. - Abstract: Cooling efficiency of a natural draft dry cooling tower decreases under crosswind condition. Many researchers frequently recommended solid windbreakers to improve the cooling efficiency. The present research work concerns with the cooling performance assessment of the cooling tower under crosswind condition when the windbreakers are fabricated from the same type of cooling tower radiators. Computational fluid dynamics approach based on the finite volume method has been used to assess the cooling performance of the cooling tower. Numerical results show that radiator type windbreakers can substantially more improve the cooling efficiency than the usual solid types do

  14. 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

  15. Analysis of the new cooling tower in Šoštanj on temperature action

    OpenAIRE

    S?abec, Tomaz?

    2013-01-01

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

  16. Demineralised water cooling in the LHC accelerator

    CERN Document Server

    Peón-Hernández, G

    2002-01-01

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

  17. Three-dimensional numerical study on thermal performance of a super large natural draft cooling tower of 220m height

    Science.gov (United States)

    Jin, Tai; Zhang, Li; Luo, Kun; Fan, Jianren

    2013-06-01

    Based on the heat and mass transfer theory and the characteristics of general-purpose software FLUENT, a three-dimensional numerical simulation platform, composed of lots of user defined functions(UDF), has been developed to simulate the thermal performance of natural draft wet cooling towers(NDWCTs). After validation, this platform is used to analyse thermal performances of a 220m high super large cooling tower designed for inland nuclear plant under different operational conditions. Variations of outlet temperature of the cooling tower caused by changes of water flow rates, inlet water temperatures are investigated. Effects of optimization through non-uniform water distributions on outlet water temperature are discussed, and the influences on the flow field inside the cooling tower are analyzed in detail. It is found that the outlet water temperature will increase as the water flow rate increases, but the air flow rate will decrease. The outlet water temperature will decrease 0.095K and 0.205K, respectively, if two non-uniform water distribution approaches are applied.

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

    International Nuclear Information System (INIS)

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

  19. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    International Nuclear Information System (INIS)

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

  2. 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

  3. 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

  4. Thermodynamic study of the effects of ambient air conditions on the thermal performance characteristics of a closed wet cooling tower

    International Nuclear Information System (INIS)

    A thermodynamic model was developed and used to assess the sensitivity of thermal performance characteristics of a closed wet cooling tower to inlet air conditions. In the present study, three cases of different ambient conditions are considered: In the first case, the average mid-winter and mid-summer conditions as well as the extreme case of high temperature and relative humidity, in Athens (Greece) during summer are considered according to the Greek Regulation for Buildings Energy Performance. In the second case, the varied inlet air relative humidity while the inlet air dry bulb temperature remains constant were taken into account. In the last case, the effects on cooling tower thermal behaviour when the inlet air wet bulb temperature remains constant were examined. The proposed model is capable of predicting the variation of air thermodynamic properties, sprayed water and serpentine water temperature inside the closed wet cooling tower along its height. The reliability of simulations was tested against experimental data, which were obtained from literature. Thus, the proposed model could be used for the design of industrial and domestic applications of conventional air-conditioning systems as well as for sorption cooling systems with solid and liquid desiccants where closed wet cooling towers are used for precooling the liquid solutions. The most important result of this theoretical investigation is that the highest fall of serpentine water temperature and lossesof serpentine water temperature and losses of sprayed water are observed for the lowest value of inlet wet bulb temperature. Hence, the thermal effectiveness, which is associated with the temperature reduction of serpentine water as well as the operational cost, which is related to the sprayed water loss due to evaporation, of a closed wet cooling tower depend predominantly on the degree of saturation of inlet air.

  5. 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.

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

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

  8. Costs and cost algorithms for dry cooling tower systems

    Energy Technology Data Exchange (ETDEWEB)

    Ard, P.A.; Henager, C.H.; Pratt, D.R.; Wiles, L.E.

    1976-09-01

    Costs were obtained and cast models prepared for the major components beyond the turbine exhaust flange of a dry cooling system using either water or ammonia as the intermediate heat exchange fluid. (LCL)

  9. Reuso de efluentes em torres de resfriamento - estudo conceitual: Aeroporto Internacional do Rio de Janeiro = Water reuse for cooling towers – conceptual study: Rio de Janeiro International Airport

    Directory of Open Access Journals (Sweden)

    Denize Dias de Carvalho

    2010-07-01

    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 conceptthat 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 theaim 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 foreffluent 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Orgill, M.M.

    1977-10-01

    Thermal plumes or convection columns associated with large fires are compared to thermal plumes from cooling towers and proposed energy centers to evaluate the fire analog concept. Energy release rates of mass fires are generally larger than for single or small groups of cooling towers but are comparable to proposed large energy centers. However, significant physical differences exist between cooling tower plumes and fire plumes. Cooling tower plumes are generally dominated by ambient wind, stability and turbulence conditions. Fire plumes, depending on burning rates and other factors, can transform into convective columns which may cause the fire behavior to become more violent. This transformation can cause strong inflow winds and updrafts, turbulence and concentrated vortices. Intense convective columns may interact with ambient winds to create significant downwind effects such as wakes and Karman vortex streets. These characteristics have not been observed with cooling tower plumes to date. The differences in physical characteristics between cooling tower and fire plumes makes the fire analog concept very questionable even though the approximate energy requirements appear to be satisfied in case of large energy centers. Additional research is suggested in studying the upper-level plume characteristics of small experimental fires so this information can be correlated with similar data from cooling towers. Numerical simulation of fires and proposed multiple cooling tower systems could also provide comparative data.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-07-01

    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.

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

    International Nuclear Information System (INIS)

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

  13. Fog and drift deposition from evaporative cooling towers

    International Nuclear Information System (INIS)

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

  14. 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)

  15. Girassol, Riser Towers for ultra deep water

    Energy Technology Data Exchange (ETDEWEB)

    Rougier, Regis

    1999-07-01

    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.

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

    International Nuclear Information System (INIS)

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

  17. Gas-cooled breeder reactor with gas turbines and dry-cooling towers

    International Nuclear Information System (INIS)

    The purpose of this project is to conduct a systems evaluation of a gas-cooled fast reactor (GCFR) coupled to a gas turbine and using a dry cooling tower for waste heat rejection. The major goal of the project is to define those R and D problems which must be solved before the above system can become commercially and environmentally acceptable. The results indicate that the system offers a number of advantages over other proposed nuclear systems, and that a demonstration plant should be built at an early date. The following major problems require additional work: (1) Development of a new cladding material, (2) Optimization of the gas turbine dry tower combination, and (3) Construction and testing of a large closed cycle, nuclear gas turbine. (U.S.)

  18. Cooling tower for industrial installations such power stations

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    1991-01-01

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

  20. Maintenance of cooling towers following two outbreaks of Legionnaires' disease in a city.

    OpenAIRE

    Bhopal, R. S.; Barr, G.

    1990-01-01

    This survey assessed the maintenance of evaporative cooling towers in Glasgow, following two Legionnaires' disease outbreaks. Information was obtained from 76 of 81 premises and a maintenance score was calculated for each of 174 towers. The quality of maintenance was extremely varied (range of maintenance scores, 8-30; mean, 22 (S.D., 5.0); median, 23; maximum possible, 33) and some towers were neglected. Breaches of maintenance principles were mainly structural and organizational, e.g. inade...

  1. 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)

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

    International Nuclear Information System (INIS)

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

  3. Cooling towers of reinforced and prestressed concretes. Kuehltuerme aus Stahl- und Spannbeton

    Energy Technology Data Exchange (ETDEWEB)

    Breckner, F. (comp.)

    1987-01-01

    The topics of this bibliography are as follows: shells in reinforced and prestressed concretes of cooling towers, design calculation methods, dangers of corrosion, examples, and technical development and research. With 79 refs.

  4. 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)

  5. Research on the Flow-Head Characteristics of the Turbine Driving Fan in Cooling tower

    Directory of Open Access Journals (Sweden)

    Li Yanpin

    2012-11-01

    Full Text Available The flow-head characteristics of the special turbine in cooling tower are very different from the general power turbines’. This study has analyzed the former theoretically and proposed the theoretical formula of the head-flow. At the same time, the paper has studied the characteristics of the flow-head using the CFD method. The tests results have proved the principle of the flow-head of the turbine in cooling tower.

  6. Research on the Flow-Head Characteristics of the Turbine Driving Fan in Cooling tower

    OpenAIRE

    Li Yanpin; Ren Yan; Zhang Lanjin; Chen Dexin

    2012-01-01

    The flow-head characteristics of the special turbine in cooling tower are very different from the general power turbines’. This study has analyzed the former theoretically and proposed the theoretical formula of the head-flow. At the same time, the paper has studied the characteristics of the flow-head using the CFD method. The tests results have proved the principle of the flow-head of the turbine in cooling tower.

  7. Geodetic works on the construction of cooling tower of TEŠ 6

    OpenAIRE

    Kolaric?, Andrej

    2014-01-01

    The thesis discusses with geodetic works on the construction of cooling tower of sixth block in Šoštanj thermal power plant. It presents briefly the thermal power plant and describes the process of construction of the cooling tower. The establishment of basic surveying network stakeout is explained. It is also contains a full description of the stakeout procedures. Paper states the requirements and accuracy of stakeout and describes practical examples. It shows the concrete implementatio...

  8. Replacement of the cooling tower packing at the Goesgen-Daeniken AG nuclear power plant

    International Nuclear Information System (INIS)

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

  9. 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.

  10. Conversion of water towers – an instrument for conserving heritage assets

    Directory of Open Access Journals (Sweden)

    Andreea-Loreta Cercleux

    2014-06-01

    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.

  11. 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

  12. 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

  13. Transmission of waste heat to the environment - cooling with river-water and in circulating systems

    International Nuclear Information System (INIS)

    There is at present in the Federal Republic a revolution in the application of cooling methods, due to the present water economy situation for cooling water supply. Until the end of the 60's fresh-water cooling governed; today, wet closed-circuit cooling in cooling towers is coming through. Furthermore, the application of dry cooling required for the future is being prepared. A survey of the cooling methods, the related problems and the economic effects is given. (orig.)

  14. Measurement and characterization of emissions from a gas liquor fed cooling tower

    Science.gov (United States)

    Galegher, Sheila J.; Mann, Michael D.

    Phase I cooling tower testing at the University of North Dakota Energy Research Center (UNDERC) was designed to use solvent extracted and steam stripped wastewater from fixed-bed gasification of lignite as makeup. The objective of this test was to simulate the proposed mode of operation at the Great Plains Gasification Associates (GPGA) plant. A crucial part of this study was the characterization of emissions from a stripped gas liquor (SGL) fed cooling tower. Several types of sampling equipment including a multicyclone, cooled impingers, and an XAD resin trap were used for the collection and retention of components in the tower evaporate. Results of this study indicated that a significant portion of the phenol and ammonia, and also some methanol, in the tower makeup stream were stripped into the atmosphere. Concentration levels of 26,900 ?g m -3 ammonia, 8000 ?g m -3 phenol and 2500 ? m -3 methanol were detected in the lower exhaust.

  15. How to judge acceptance tests on wet cooling towers; Zur Beurteilung von Abnahmeversuchen an Nasskuehltuermen

    Energy Technology Data Exchange (ETDEWEB)

    Wernicke, D.

    1998-12-31

    In a new computer-supported procedure the conventional acceptance parameter `cold water temperature` is considered as an interaction of exchange area and air flow. A consequent application of evaporative cooling theory leads to the definition of a factor describing heat and mass transfer area. This factor is the basis of the new acceptance testing procedure. In comparison to conventional procedures based on tower-specific curve diagrams, the new physically founded acceptance procedure is applicable to a wide range of cooling towers. The division of the overall acceptance parameter into partial acceptance criteria leads to a fundamental increase in the transparency of acceptance tests and permits a thorough analysis of deficiencies as well as effective improvements. (orig.) [Deutsch] Die herkoemmliche Beurteilungsgroesse Kaltwassertemperatur wird in einem neuen, rechnergestuetzten Verfahren der thermischen Abnahme von Nasskuehltuermen als Zusammenspiel von Austauschflaeche und Luftdurchsatz begriffen. Die konsequente Anwendung der Theorie der Verdunstungskuehlung fuehrt zur Definition eines Geometriefaktors als Mass fuer die Austauschflaeche. Dieser bildet die Grundlage der Abnahmebeurteilung. Im Gegensatz zu herkoemmlichen Verfahren mit kuehltumrspezifischen Kennfeldern ist das neue Abnahmeverfahren durch die Anwendung der Theorie der Verdunstungskuehlung umfassend auf die Untersuchung von Nasskuehltuermen anwendbar. Die Aufteilung der thermischen Gesamtgarantie in Teilgarantien fuehrt zu einer wesentlichen Erhoehung der Transparenz der thermischen Abnahme und erlaubt eine eingehende Analyse von Maengeln sowie gezielte Nachbesserungen. (orig.)

  16. Concept of CFD model of natural draft wet-cooling tower flow

    Directory of Open Access Journals (Sweden)

    Hyhlík T.

    2014-03-01

    Full Text Available The article deals with the development of CFD model of natural draft wet-cooling tower flow. The physical phenomena taking place within a natural draft wet cooling tower are described by the system of conservation law equations along with additional equations. The heat and mass transfer in the counterflow wet-cooling tower fill are described by model [1] which is based on the system of ordinary differential equations. Utilization of model [1] of the fill allows us to apply commonly measured fill characteristics as shown by [2].The boundary value problem resulting from the fill model is solved separately. The system of conservation law equations is interlinked with the system of ordinary differential equations describing the phenomena occurring in the counterflow wet-cooling tower fill via heat and mass sources and via boundary conditions. The concept of numerical solution is presented for the quasi one dimensional model of natural draft wet-cooling tower flow. The simulation results are shown.

  17. 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.)

  18. 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

  19. Wind tunnel experimental study on effect of inland nuclear power plant cooling tower on air flow and dispersion of pollutant

    International Nuclear Information System (INIS)

    A wind tunnel experiment for the effect of the cooling tower at Taohuajiang nuclear power plant on air flow and dispersion of pollutant was introduced in paper. Measurements of air mean flow and turbulence structure in different directions of cooling tower and other buildings were made by using an X-array hot wire probe. The effects of the cooling tower and its drift on dispersion of pollutant from the stack were investigated through tracer experiments. The results show that the effect of cooling tower on flow and dispersion obviously depends on the relative position of stack to cooling towers, especially significant for the cooling tower parallel to stack along wind direction. The variation law of normalized maximum velocity deficit and perturbations in longitudinal turbulent intensity in cooling tower wake was highly in accordance with the result of isolated mountain measured by Arya and Gadiyaram. Dispersion of pollutant in near field is significantly enhanced and plume trajectory is changed due to the cooling towers and its drift. Meanwhile, the effect of cooling tower on dispersion of pollutant depends on the height of release. (authors)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  2. 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

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

    OpenAIRE

    Hasan, Ala Ali

    2005-01-01

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

  4. Overview of the Chalk Point Cooling Tower Project, 1972-1979

    Energy Technology Data Exchange (ETDEWEB)

    Moon, M.L. (ed.)

    1979-03-01

    The objectives, methodologies, data, and analytical results of the Chalk Point Cooling Tower Program are reviewed. The overview intergrates the concepts and activities of the various program elements to provide a coherent view of the program in its entirety. Samples of the various data acquired are included together with very brief summaries of the conclusions. The report is extensively referenced to provide specific directions to the more extensive treatments of the program, data tabulations, and tape libraries available in the complete library of Chalk Point reports. The Chalk Point data is a resource for the study of cooling tower salt deposition processes and impacts in general. The methods used, while developed to facilitate the assessment of salt drift impact at Chalk Point, also have applicability to cooling tower impact analysis at other sites.

  5. 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

  6. Measurements in natural-draft wet cooling towers at the nuclear power station Philippsburg 1

    International Nuclear Information System (INIS)

    An extensive measuring programme was carried out on the cooling tower of the nuclear power plant Phillipsburg in spring 1980, to simultaneously record all necessary parameters, and to compile the results to complete data sets. The aim of the programme was as follows: - to improve the state of knowledge by means of an extensive interdisciplinary field study, - to verify expert opinions- and calculated predictions (models for operation characteristics, emissions and propagation), - to inform the public of efforts made for environmentally sound cooling tower operation. The work was performed in 8 partial projects by interdisciplinary working groups of scientists. (orig./GL)

  7. Thermal Characteristics of Heating Towers

    Science.gov (United States)

    Fujita, Toshihiko; Kametani, Shigeki

    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.

  8. Prevalence and concentration of non-tuberculous mycobacteria in cooling towers by means of quantitative PCR: a prospective study.

    Science.gov (United States)

    Adrados, Bárbara; Julián, Esther; Codony, Francesc; Torrents, Eduard; Luquin, Marina; Morató, Jordi

    2011-01-01

    There is an increasing level of interest in non-tuberculous mycobacteria (NTM) due to the increasing reported rates of diseases caused by them. Although it is well known that NTM are widely distributed in the environment it is necessary to identify its reservoirs to prevent possible infections. In this study, we aimed to investigate the occurrence and levels of NTM in cooling towers to provide evidences for considering these settings as possible sources of respiratory infections. In the current study, we detected and quantified the presence of NTM by means of a rapid method in water samples taken from 53 cooling towers of an urban area (Barcelona, Spain). A genus-specific quantitative PCR (Q-PCR) assay with a quantification limit (QL) of 500 cells l(-1) was used. 56% (30) of samples were positive with a concentration range from 4.6 × 10(3) to 1.79 × 10(6) cells l(-1). In some cases (9/30), samples were positive but with levels below the QL. The colonization rate confirmed that cooling towers could be considered as a potential reservoir for NTM. This study also evaluated Q-PCR as a useful method to detect and quantify NTM in samples coming from environmental sources. PMID:20640853

  9. Experimental measurement of cooling tower emissions using image processing of sensitive papers

    Science.gov (United States)

    Ruiz, J.; Kaiser, A. S.; Ballesta, M.; Gil, A.; Lucas, M.

    2013-04-01

    Cooling tower emissions are harmful for several reasons such as air polluting, wetting, icing and solid particle deposition, but mainly due to human health hazards (i.e. Legionella). There are several methods for measuring drift drops. This paper is focussed on the sensitive paper technique, which is suitable in low drift scenarios and real conditions. The lack of an automatic classification method motivated the development of a digital image process algorithm for the Sensitive Paper method. This paper presents a detailed description of this method, in which, drop-like elements are identified by means of the Canny edge detector combined with some morphological operations. Afterwards, the application of a J48 decision tree is proposed as one of the most relevant contributions. This classification method allows us to discern between stains whose origin is a drop and stains whose origin is not a drop. The method is applied to a real case and results are presented in terms of drift and PM10 emissions. This involves the calculation of the main features of the droplet distribution at the cooling tower exit surface in terms of drop size distribution data, cumulative mass distribution curve and characteristic drop diameters. The Log-normal and the Rosin-Rammler distribution functions have been fitted to the experimental data collected in the tests and it can been concluded that the first one is the most suitable for experimental data among the functions tested (whereas the second one is less suitable). Realistic PM10 calculations include the measurement of drift emissions and Total Dissolved Solids as well as the size and number of drops. Results are compared to the method proposed by the U.S. Environmental Protection Agency assessing its overestimation. Drift emissions have found to be 0.0517% of the recirculating water, which is over the Spanish standards limit (0.05%).

  10. Cost and performance optimization of natural draft dry cooling towers using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Shokuhmand, H.; Ghaempanah, B. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2005-07-01

    The performance of a dry cooling tower plays an important role in the efficiency of power generation. Therefore, the technical and economical optimization of dry cooling towers is critical. This paper discussed the cost of design and erection of natural draft dry cooling towers with particular reference to a compact heat exchangers known as Forgo T60. An actual operating power plant was used to validate the results achieved by means of a genetic algorithm. In addition, a comparison was made between the performance optimization based on cost only and based on cost-performance. It was concluded that an optimization based on cost function only does not offer reliable optimum design parameters. It was suggested that the variations of ambient temperature during a year should be considered as input data along with the characteristic curve of turbine-generator because an increase in wind velocity can affects the performance of the tower by changing the distribution of pressure around the base and top of the tower. 16 refs., 2 tabs., 5 figs.

  11. Experimental study regarding the evolution of temperature profiles inside wet cooling tower under cross-wind conditions

    International Nuclear Information System (INIS)

    Based on similarity theory, this research details a thermal-state model experiment, concerning the evolution of the air/water temperature profiles inside a Natural Draft Wet Cooling Tower (NDWCT) under windless and cross-wind conditions. Prior studies have shown that the air/water temperature distribution is fairly uniform and stable under windless (stagnant) conditions, but the uniformity is destroyed in the presence of windy conditions, and the air/water temperature of different points displays a large variation subject to the same cross-wind velocity. Generally speaking, the highest air/water temperature values inside the whole tower lie on the windward and leeward direction, but the highest air temperature at the tower outlet appears near the leeward side zone, rather than exactly on the leeward side. Based on this research, the air/water temperature profiles regarding measurement of values can be obtained accurately under windless and cross-wind conditions, a fact that can help confirm the specific location of vortex on the windward and leeward side. All of above findings can provide an important theoretical foundation concerning further research, specifically for energy-saving aspects NDWCTs. (authors)

  12. 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.)

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

    Science.gov (United States)

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

    2011-12-01

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

  14. Observations of cooling tower and stack plumes and their comparison with plume model "ALINA"

    Science.gov (United States)

    Haman, Krzysztof E.; Malinowski, Szymon P.

    Aircraft observations of stack and cooling tower plumes taken at a big power plant are compared with corresponding outputs of one-dimensional plume model ALINA, yielding certain improvements to the entrainment parametrization and dynamics of the model. Some observations of plume-plume and plume-environment interactions are reported.

  15. Cooling tower drift study at the Oak Ridge Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    The environmental study of cooling towers at the ORGDP was continued in 1978. The first investigation conducted in 1973 provided valuable first hand information on drift from two cooling tower cells at ORGDP; however, the drift percentage of 0.1% measured in that test appeared to be high. The 1978 drift study was planned and performed to more closely define the drift phenomenon of the cooling tower complex. The cooling tower cells were involved in the test with drift and ground deposition measurements being performed simultaneously. The average drift percentage measured in this test was 0.03% with acceptable agreement among the ten cells tested. The downfield deposition measurements of chromium supported the deposition findings of the 1973 study. The results of the 1978 studies are considered more reliable than those obtained in 1973 because of the greater mass of data obtained from a greater number of tested cells. The results also indicated that the sensitive paper method with its large sampling volume provides more reliable source characteristics information than the optical measuring device with a very small sampling volume

  16. 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

  17. 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

  18. Thermoelectrically cooled water trap

    Science.gov (United States)

    Micheels, Ronald H. (Concord, MA)

    2006-02-21

    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.

  19. 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

  20. 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.)

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

    International Nuclear Information System (INIS)

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

  2. Spreading of cracks in R. C. hyperbolic cooling towers with and without imperfection due to weight, thermal and wind loads

    International Nuclear Information System (INIS)

    Imprecise construction work might cause imperfection in the shell of R.C.hyperbolic cooling towers. The cooling towers with large imperfection could collapse due to wind load. The aim of this research is to study the cracks spreading in the shell of a typical R.C. cooling tower with and without imperfection. In Finite Element analysis reinforce bars with nonlinear behavior and solid elements were used. The solid elements which were used in this analysis could crack in three directions. The study on the sample cooling towers showed that deformations and crack spreading differ in the cooling tower shell with and without imperfection due to weight and thermal loads. At he end of the weight and thermal loads, vertical cracks were seen all over the outer side of the perfect shell and intermittent horizontal cracks happened in the shell of cooling tower where it had : its minimum thickness. On the other hand, in an imperfect shell, intermittent vertical and horizontal cracks were seen on the outside of the cooling tower shell due to the weight and thermal loads. When wind loads was added to the weight and thermal loads, the cracks spreading was seen to be similar for both perfect and imperfect R.C. Shell

  3. Calder Hall Cooling Tower Demolition: Landmark Milestone for Decommissioning at Sellafield

    International Nuclear Information System (INIS)

    September 2007 saw a very visible change to the Sellafield site following the culmination of a major decommissioning project; the demolition of the four Calder Hall cooling towers. A key part of the UK's nuclear industrial heritage, Calder Hall, the world's first commercial nuclear power station, was opened by Her Majesty Queen Elizabeth II in October 1953 and continued to generate electricity until its closure in 2003. Following the decision to decommission the Calder Hall site, explosive demolition was identified as the safest and most cost effective route for the removal of the towers. The technique, involving the placement of explosive in 60% of the circumference of both shell and legs, is a tried and tested method which had already been used successfully in more than 200 cooling towers in the UK in the last 30 years. The location and composition of the four 88 metre high towers also created additional challenges. Situated only 40 metres away from the UK's only nuclear Fuel Handling Plant, as well as other sensitive structures on the Sellafield site, the project had to address the impact of a number of key areas, including dust, ground vibration and air over pressure, to ensure that the demolition could be carried out safely and without significant impact on other operational areas on the site. At the same time, the towers had to be prepared for demolition in a way that minimised the amounts of radioactive or hazardous waste materials arising. This paper follows tte materials arising. This paper follows the four year journey from the initial decision to demolish the towers right through to the demolition itself as well as the clean up of the site post demolition. It will also consider the massive programme of work necessary not only to carry out the physical work safely but also to gain regulatory confidence and stakeholder support to carry out the project successfully. In summary: The demolition of the four Calder Hall cooling towers was a highly visible symbol of the changes that are occurring on the Sellafield site as it moves forward towards a decommissioning future. Although in itself the demolition was both straightforward and standard, the various complexities posed by the towers situation at Sellafield introduced an entirely new element to the project, with a number of complex challenges which had to be overcome or resolved before the demolition could take place. It is a testament to the skill and dedication of the project team and its associated contractors that the project was delivered safely and successfully without a single accident, injury or event throughout the entire four years, and with minimal impact on both site operations and the local community. (authors)

  4. 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)

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

    International Nuclear Information System (INIS)

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

  6. Cooling clothing utilizing water evaporation

    DEFF Research Database (Denmark)

    Sakoi, Tomonori; Tominaga, Naoto

    2014-01-01

    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.

  7. Energy penalty analysis of possible cooling water intake structurerequirements on existing coal-fired power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Littleton, D. J.; Gross, R. W.; Smith, D. N.; Parsons, E.L., Jr.; Shelton, W. W.; Feeley, T. J.; McGurl, G. V.

    2006-11-27

    Section 316(b) of the Clean Water Act requires that cooling water intake structures must reflect the best technology available for minimizing adverse environmental impact. Many existing power plants in the United States utilize once-through cooling systems to condense steam. Once-through systems withdraw large volumes (often hundreds of millions of gallons per day) of water from surface water bodies. As the water is withdrawn, fish and other aquatic organisms can be trapped against the screens or other parts of the intake structure (impingement) or if small enough, can pass through the intake structure and be transported through the cooling system to the condenser (entrainment). Both of these processes can injure or kill the organisms. EPA adopted 316(b) regulations for new facilities (Phase I) on December 18, 2001. Under the final rule, most new facilities could be expected to install recirculating cooling systems, primarily wet cooling towers. The EPA Administrator signed proposed 316(b) regulations for existing facilities (Phase II) on February 28, 2002. The lead option in this proposal would allow most existing facilities to achieve compliance without requiring them to convert once-through cooling systems to recirculating systems. However, one of the alternate options being proposed would require recirculating cooling in selected plants. EPA is considering various options to determine best technology available. Among the options under consideration are wet-cooling towers and dry-cooling towers. Both types of towers are considered to be part of recirculating cooling systems, in which the cooling water is continuously recycled from the condenser, where it absorbs heat by cooling and condensing steam, to the tower, where it rejects heat to the atmosphere before returning to the condenser. Some water is lost to evaporation (wet tower only) and other water is removed from the recirculating system as a blow down stream to control the building up of suspended and dissolved solids. Makeup water is withdrawn, usually from surface water bodies, to replace the lost water. The volume of makeup water is many times smaller than the volume needed to operate a once-through system. Although neither the final new facility rule nor the proposed existing facility rule require dry cooling towers as the national best technology available, the environmental community and several States have supported the use of dry-cooling technology as the appropriate technology for addressing adverse environmental impacts. It is possible that the requirements included in the new facility rule and the ongoing push for dry cooling systems by some stakeholders may have a role in shaping the rule for existing facilities. The temperature of the cooling water entering the condenser affects the performance of the turbine--the cooler the temperature, the better the performance. This is because the cooling water temperature affects the level of vacuum at the discharge of the steam turbine. As cooling water temperatures decrease, a higher vacuum can be produced and additional energy can be extracted. On an annual average, once-through cooling water has a lower temperature than recirculated water from a cooling tower. By switching a once-through cooling system to a cooling tower, less energy can be generated by the power plant from the same amount of fuel. This reduction in energy output is known as the energy penalty. If a switch away from once-through cooling is broadly implemented through a final 316(b) rule or other regulatory initiatives, the energy penalty could result in adverse effects on energy supplies. Therefore, in accordance with the recommendations of the Report of the National Energy Policy Development Group (better known as the May 2001 National Energy Policy), the U.S. Department of Energy (DOE), through its Office of Fossil Energy, National Energy Technology Laboratory (NETL), and Argonne National Laboratory (ANL), has studied the energy penalty resulting from converting plants with once-through cooling to wet towers or indirect-dry towers. Five l

  8. 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.

  9. A new procedure for treating cooling tower feedwater by slow decarbonization

    International Nuclear Information System (INIS)

    The treatment techniques for cooling tower feedwater in power plant engineering have been evaluated during the last few years; by now, sedimentation techniques have largely replaced filtration techniques, the main interest being in parallel-plate sedimentation. However, until now, this technique, which saves costs and space, could not be employed without risk while the conventional methods of slow decarbonization were still used. A method for the long-term decarbonization of surface water is described which, although the dosage of chemicals is the same as with conventional techniques (e.g. x-ators), leads to a decarbonate with practically no calcareous sedimentation. The fundamentals of this process and its large-scale application are dealt with. Development on a semi-industrial scale was started in 1975 with experiments at the Biblis nuclear power station. These experiments also dealt with the effects of the so-called 'LME' sludge solidification principle on the concentration and dehydration of decarbonization sludges. A large-scale plant working according to this principle will be built for the nuclear power station at Grafenrheinfeld. Problems of redundancy, overloading, flexibility, and safety are discussed. The plant may also be used for flocculation with sulphuric acid decarbonization without requiring technical changes. (orig./HK)

  10. An alkaline approach to treating cooling towers for control of Legionella pneumophila.

    OpenAIRE

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

    1987-01-01

    Earlier field and laboratory studies have shown that Legionella species survive and multiply in the pH range 5.5 to 9.2. Additionally, the technical feasibility of operating cooling towers at elevated alkalinities and pH has previously been documented by published guidelines. The guidelines indicate that these conditions facilitate corrosion control and favor chlorine persistence which enhances the effectiveness of continuous chlorination in biofouling control. This information suggests that ...

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

    OpenAIRE

    Kraetzig, Wilfried B.; Harte, Reinhard; Montag, Ulrich; Woermann, Ralf

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

  13. 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.)

  14. Improvements achieved in the cooling tower performance at the Leibstadt Nuclear Power Plant

    International Nuclear Information System (INIS)

    Appreciable improvements in the overall efficiency of various power plants can be obtained by modifications at the cold end of the thermal cycle. This paper summarizes new methods of analysis of this part of the plant and how these have successfully been used at the Leibstadt Nuclear Power Plant. The relatively low cost of performing these modifications has led to an investment pay back time of only 2 months. The problem of non optimum design of the cooling systems, cooling towers, condenser evacuation systems etc. seems to be caused generically by the lack of adequate engineering tools at the time the plants were built

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

    OpenAIRE

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

    1984-01-01

    Cooling towers are considered to be man-made amplifiers of Legionella spp. Thus, the proper maintenance and choice of biocides is important. The only biocidal measure that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies with 1-bromo-3-chloro-5, 5-dimethylhydantoin (Bromicide; Great Lakes Chemical Corp., West Lafayette, Ind.) (BCD) were conducted on an industrial cooling tower shown to contain Legionella pneumophila. At the conc...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Feng; Li, Yi [Department of Building Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Gu, Xianglin, E-mail: gxl@tongji.edu.cn [Department of Building Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Zhao, Xinyuan [Department of Building Engineering, Tongji University, No. 1239 Siping Road, Shanghai 200092 (China); Tang, Dongsheng [Guangdong Electric Power Design Institute, No. 1 Tianfeng Road, Guangzhou, Guangdong 510663 (China)

    2013-05-15

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

  18. What comes out of the Goesgen cooling tower

    International Nuclear Information System (INIS)

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

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, S.R.

    1976-01-01

    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 power plant in West Virginia. The three natural draft cooling towers are 200 m apart. In a cross wind, the plumes begin to merge at a distance of about 500 m downwind. In calm conditions, with reduced entrainment, the plumes often do not merge until heights of 1000 m. The average plume rise, 750 m, is predicted well by the models, but day-to-day variations are simulated with a correlation coefficient of about 0.5. Model predictions of visible plume length agree, on the average, with observations for visible plumes of short to moderate length (less than about 1 km). 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 (about 0.1 to 1 g kg/sup -1/).

  1. A Study on Evaluation of Corrosion Properties in cooling tube of water cooling transformers

    International Nuclear Information System (INIS)

    Most of the thirteen substations in operation in the metropolitan area were installed around the year 2000, and since water cooling methods are used to directly withdraw heat from transformer oils, a stable supply of electric power is required through optimal maintenance of facilities. The water cooling tower installed outdoors, which uses the water supply as sprinkler water, experiences the most problems. Since more than 90% of the cooling water is reused, the dissolved composition in the water becomes concentrated due to long operating hours, and impurities dissolve in the water due to air flowing in from the outside, forming hard scales on the outer surface of the cooling tube, and in extreme cases, reacting with the tube material composition, leading to corrosion. As a result, not only is cooling efficiency lowered, but in extreme cases the cooling tube must be replaced. In this study, the characteristics and composition of the scales formed on the cooling tube were analyzed and corrosion characteristics of material types wee identified in order to find an efficient maintenance method for cooling tubes. In addition, the degree of dissolution of various chemicals were investigated during the removal of scales that have been formed

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

    International Nuclear Information System (INIS)

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

  3. Application of solar collectors to control the visible plume from wet cooling towers of a commercial building in Hong Kong: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.W.; Tyagi, S.K. [Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (China); Sharma, Atul [Department of Mechanical Engineering, Kun Shan University, Yung-Kung City, P.O. Box 40-91, Tainan 710 (China); Kaushik, S.C. [Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016 (India)

    2007-06-15

    This communication presents a case study on the application and utility of solar collectors heating system to control the visible plume from wet cooling towers of a huge commercial building. The visibility of plume from cooling towers depends on the weather conditions, specially, the temperature and relative humidity of the ambient air. Although the ambient temperature is the main parameter for the visibility of plume yet the relative humidity also plays a vital role in some cases such as Hong Kong, Europe, Canada and other similar regions in the world. The present study is on the control of plume from wet cooling towers of a huge commercial building, particularly, in Hong Kong and can be used as a base for other places in general. The analysis is done based on the hourly weather data available from the metrological department for a particular year. In this case study the calculations are done using the water cooled and the air cooled solar collectors and the comparison is also given among the different possible options. (author)

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

    OpenAIRE

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

    2009-01-01

    In this study, using a combination of Pinch Technology and Mathematical Programming, a new technique is presented in order to grass-root design for a cooling water system to achieve minimum total annual cost. The presented technique is further improved by using patterns from the concept of regeneration recycling in water systems; in a sense that cooling water is regenerated locally by an air cooler. Moreover, in the proposed method, optimum design of cooling tower has been achieved thr...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ken Mortensen

    2011-12-31

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  9. Analysis of the new cooling tower in Šoštanj on wind actions

    OpenAIRE

    C?aks?, Ditka

    2013-01-01

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

  10. Response Analysis of an RC Cooling Tower Under Seismic and Windstorm Effects

    OpenAIRE

    Makovic?ka, D.

    2006-01-01

    The paper compares the RC structure of a cooling tower unit under seismic loads and under strong wind loads. The calculated values of the envelopes of the displacements and the internal forces due to seismic loading states are compared with the envelopes of the loading states due to the dead, operational and live loads, wind and temperature actions. The seismic effect takes into account the seismic area of ground motion 0.3 g and the ductility properties of a relatively rigid structure. The d...

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

    International Nuclear Information System (INIS)

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

  12. 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. The primary reason for supplying low conductivity water to the DIII-D vacuum vessel coils, power supplies and auxiliary heating components is to assure, along with the use of a non-conducting break in the supply piping, sufficient electrical resistance and thus an acceptable current-leakage path to ground at operating voltage potentials. As important, good quality cooling water significantly reduces the likelihood of scaling and fouling of flow passages and heat transfer surfaces. Dissolved oxygen gas removal is also required in one major DIII-D cooling water system to minimize corrosion in the ion sources of the neutral beam injectors. Currently, the combined pumping capacity of the high quality cooling water systems at DIII-D is ?5,000 gpm. Another area that receives close attention at DIII-D is the chemical treatment of the water used in the cooling towers. 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

  13. Factors influencing the effectiveness of ion exchange resins used for chromate removal [from cooling tower effluents

    International Nuclear Information System (INIS)

    Factors influencing the effectiveness of ion exchange resins used for chromate removal [from cooling tower effluents] containing chromate-based corrosion inhibitors, such as the CL-68 solution (17% zinc, 15% chromate), were studied in batch equilibrium experiments at ambient temperature. The adsorptive capacity (AC) of Amberlite IRA-900 resin markedly deteriorated with decreasing pH (3.3 to 6.1) from a maximum at pH.5. Experiments on chromate adsorption in the presence of typical cooling tower blowdown impurities showed a reduction in the AC of the resin at > 3000 ppM sodium chloride, but no adverse effect of sodium 2,4,5-trichlorophenate (70 to 314 ppM) or burner fuel oil (37 to 166 ppM) at pH.5 and 183 to 265 ppM input chromate concentration. Packed column studies supported the batch test results on the effect of pH and fuel oil (17,500 ppM) and showed no deterioration in the resin AC from the Triton X surfactant solution which was used to clean resin fouled by the fuel oil

  14. 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)

    Daily III, W D

    2010-02-24

    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.

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

    International Nuclear Information System (INIS)

    This document was created to comply with the Central Valley Regional Water Quality Control Board (CVRWQCB) Waste Discharge Requirement (Order No. 98-148). This order established new requirements to assess the effect of and effort required to reduce salts in process water discharged to the subsurface. This includes the review of technical, operational, and management options available to reduce total dissolved solids (TDS) concentrations in cooling tower and mechanical equipment water discharges at Lawrence Livermore National Laboratory's (LLNL's) Experimental Test Site (Site 300) facility. It was observed that for the six cooling towers currently in operation, the total volume of groundwater used as make up water is about 27 gallons per minute and the discharge to the subsurface via percolation pits is 13 gallons per minute. The extracted groundwater has a TDS concentration of 700 mg/L. The cooling tower discharge concentrations range from 700 to 1,400 mg/L. There is also a small volume of mechanical equipment effluent being discharged to percolation pits, with a TDS range from 400 to 3,300 mg/L. The cooling towers and mechanical equipment are maintained and operated in a satisfactory manner. No major leaks were identified. Currently, there are no re-use options being employed. Several approaches known to reduce the blow down flow rate and/or TDS concentration being discharged to the percolation pits and septic systems were reviewed for technical feasibility and cost viewed 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.

  16. Auxiliary equipment cooling water system for nuclear power plant

    International Nuclear Information System (INIS)

    The present invention concerns an auxiliary equipment cooling water system for a nuclear power plant, which reduces after-heat during operation, increases heat efficiency of the plant, improves the economy and mitigates circumstantial problems. That is, condensates condensed in a main condensator are introduced to a condensate desalting tower by a pump and then cleaned. Cleaned condensates are bypassed and introduced to an auxiliary equipment heat exchanger used for the time during operation and cooled. Cooled condensates are introduced to a feedwater heater by a highly pressurized condensate pump connected to the downstream of the condensate desalting tower and then heated. They are supplied into a reactor pressure vessel as coolants. That is, heat removed by using condensates, instead of sea water, which are condensed in the main condensator is recovered to a feedwater system of the nuclear reactor. As a result, a heat efficiency of the plant can be increased by 0.5 to 0.6%. With such procedures, possibility of releasing radioactivity into the sea water due to leakage of the cooling water of the equipments during operation is decreased. (I.S.)

  17. 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

  18. 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

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

    International Nuclear Information System (INIS)

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

  20. Chlorination and dechlorination of nuclear reactor cooling water

    International Nuclear Information System (INIS)

    Effects from chlorination and dechlorination of Savannah River water were studied during the development of biofouling countermeasures for a proposed cooling tower system required for thermal mitigation of nuclear reactor cooling water effluent. Testing was conducted to assess chlorine demand and dissipation rates as well as the environmental acceptability of using sodium sulfite as a dechlorinating agent. Chlorine demand varied significantly, but in an unpredictable manner during seven seasonal sampling dates. A chlorine dosage of 3-5 mg/l was generally adequate to provide a free chlorine residual of 1 mg/l. Static 48-h bioassays with bluegill showed no acute toxicity for chlorinated/dechlorinated cooling water containing up to 64 times the calculated stoichiometric concentration of sodium sulfite required for dechlorination. Experiments measuring the depletion of dissolved oxygen and flow-through (96-h) bioassays with bluegill and largemouth bass further substantiated the environmental acceptability of using sodium sulfite as a dechlorinating agent. (author)

  1. Power control method for heavy water moderated-light water cooled pressure tube type reactor

    International Nuclear Information System (INIS)

    The present invention concerns a method of controlling the power of a heavy water moderated and light water cooled pressure tube reactor by controlling the concentration of poisons in heavy water moderators. Fine particles of chemically stable poisons not ionized in heavy water are dispersed and mixed in a heavy water system. In order to remove the poison particles from the heavy water to lower the poison concentration, heavy water branched from a heavy water cooling system and processed through a heavy water cleanup tower is passed through filters of a poison concentration control system. Accordingly, poisons can be removed even if the temperature of heavy water is high, to eliminate loss of heat. Since the filters can be regenerated by back-washing with heavy water, with no requirement of particular liquid chemicals, liquid chemical wastes are not produced. Further, little heavy water wastes are caused upon regeneration. (I.N.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Shokuhmand, H.; Ghaempanah, B. [Univ. of Tehran, Dept. of Mechanical Engineering, Tehran (Iran, Islamic Republic of)]. E-mail: hshokouh@me.ut.ac.ir; bghaempanah@me.ut.ac.ir

    2005-07-01

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

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

    International Nuclear Information System (INIS)

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

  4. Dry cooling towers for GT-MHR - HTR2008-58182

    International Nuclear Information System (INIS)

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

  5. Response Analysis of an RC Cooling Tower Under Seismic and Windstorm Effects

    Directory of Open Access Journals (Sweden)

    D. Makovi?ka

    2006-01-01

    Full Text Available The paper compares the RC structure of a cooling tower unit under seismic loads and under strong wind loads. The calculated values of the envelopes of the displacements and the internal forces due to seismic loading states are compared with the envelopes of the loading states due to the dead, operational and live loads, wind and temperature actions. The seismic effect takes into account the seismic area of ground motion 0.3 g and the ductility properties of a relatively rigid structure. The ductility is assessed as the reduction in seismic load. In this case the actions of wind pressure are higher than the seismicity effect under ductility correction. The seismic effects, taking into account the ductility properties of the structure, are lower than the actions of the wind pressure. The other static loads, especially temperature action due to the environment and surface insulation are very important for the design of the structure. 

  6. Fuzzy Logic Application for Optimization of the Cooling Towers Control System

    CERN Document Server

    Blanc, D

    2000-01-01

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

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-07-01

    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.

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

    Science.gov (United States)

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

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

  11. 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.

  12. 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)

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

    International Nuclear Information System (INIS)

    Savannah River Site is an 800-square kilometer (310-square mile) U.S. Department of Energy (DOE) industrial facility located in Aiken, Allendale, and Barnwell Counties in South Carolina. The site is dedicated to environmental cleanup, developing and deploying technologies to support the cleanup mission, processing and storing nuclear materials, and supporting national security missions. The current focus in environmental management is on the cleanup of legacy materials, facilities and wastes left from the Cold War. In 2002 the DOE initiated actions to expedite cleanup focusing on significant risk reduction coupled with reducing costs. SRS published the Savannah River Site Environmental Management Integrated Deactivation and Decommissioning Plan in 2003 which addressed the final disposition and physical end state of all 1,013 Environmental Management facilities on site by the year 2025. Included in this list of facilities are reactors, fabrication facilities, process facilities and the support facilities that were required during the past 50 years. By the end of FY06, over 200 facilities had been decommissioned. This paper describes the demolition of two facilities, cooling towers 285-H and 285-F that were associated with the operation of the process canyons. Because of the circumstances surrounding these decommissions, unique and unusual techniques were safely employed to demolish and remove the cooling towers. Both 285-H and 285-F were safely felled by pulling the co285-F were safely felled by pulling the columns remotely to weaken the internal portion of the structure so it would collapse inwards into the basin. Cooling tower 285-H fell in less than 1 second after approximately two-thirds of the columns had been broken. See Figure 3 for a photo of 285-H after its collapse. 285-F, which was larger than 285-H, fell in three sections, two cells at a time. Once the towers were felled conventional demolition equipment was used to segregate and remove the debris. All protective measures used to protect surrounding equipment and structures were successful and the basins were cleaned out and returned to service in less than two weeks. The demolition of both cooling towers 285- H and 285-F was completed safely and timely using unconventional means to fell the towers due to structural degradation, height, limited access, radiological and asbestos hazards, and a requirement to protect equipment on all sides of the facility as well as preservation of the basins. During felling operations personnel were required to stay outside the fall zone equivalent to a distance of 150% of the height of the towers. Remote operations outside the fall zone required a tracked vehicle to pull cables attached to the columns in a predetermined sequence so as to fell the tower straight down into the basin. Once the towers fell traditional demolition equipment segregated and removed the waste. Wooden cooling towers of this vintage present a difficult challenge to traditional demolition techniques. Because of the height and potential instability of these types of facilities, considerable effort is placed on reducing the potential energy to a point where heavy equipment can reach safely without endangering the operators. The column-pulling technique chosen for both 285-H and 285-F cooling towers proved to be a safe and efficient method for demolition of these types of facilities

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-09-01

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

  15. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-08-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  19. Buffeting along-wind loads on ventilation stack of nuclear power stations due to nearby natural draft cooling towers

    International Nuclear Information System (INIS)

    Buffet loads due to high turbulence wakes of natural draft cooling towers (NDCT) on ventilation stacks of nuclear power stations is analysed using existing theories by making certain assumptions about the scale and intensity of turbulence. This issue can be important since these stacks do not carry any heavy linings as on stacks of thermal power stations and hence are prone to higher buffet loads. Results are compared with some wind tunnel model experimental data and found to give reasonable conservative estimates. (author)

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

    Directory of Open Access Journals (Sweden)

    Amir-Samimi

    2013-04-01

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

  1. 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)

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

    2013-07-01

    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.

  2. Water cooled pebble bed reactor

    International Nuclear Information System (INIS)

    Nuclear energy is expected to contribute largely to the worldwide future electricity supply. However, the severe incidents in Three Mile Island / Harrisburg and Tschernobyl have lead to stricter requirements concerning safety aspects as well as final disposal. Therefore new safety concepts are investigated worldwide. The fulfilment of nuclear, thermal, chemical and mechanical stability in each operating state is an essential demand in the new concepts. The development of this innovative reactor is motivated by some general considerations, which transfer the safety characteristics of spherical fuel elements, known from the HTR-technology, to reactors using different cooling media. The use of water as coolant implies the advantage of using advanced primary and secondary circuit technology of existing pressurized-water reactors (PWRs) of western type that are currently at work. Besides thermal-hydraulic parameters of PWRs and therefore high thermal outputs can be obtained. (orig.)

  3. Determination of both thermohydraulic and mass-sized parameters of a power unit cooling system on the base of dry tower

    International Nuclear Information System (INIS)

    The block diagram of calculate of thermohydraulic and mass-sized parameters of a cooling system of power units on the basis of dry tower is described. Data of optimization calculations on determination of main parameters dry towers and condenser for power unit of WWER-1000 are indicated. On the basis of the analysis mass-sized and cost characteristics, a choice of optimum parameters of dry towers for a cooling system of the power unit is justified. 10 refs., 5 tabs., 2 figs

  4. The constructional design of cooling water discharge structures on German rivers

    International Nuclear Information System (INIS)

    The present compilation of structures for discharging cooling water from power stations into rivers is an attempt to make evident developments in the constructional design of such structures and to give reasons for special structure shapes. A complete collection of all structures built in Germany, however, is difficult to realize because of the large number of power stations. For conventionally heated power stations therefore only a selection was made, while nuclear power stations in operation or under construction could almost completely be taken into account. For want of sufficient quantities of water for river water cooling, projected power stations are now almost exclusively designed for closed-circuit cooling so that the required discharge structures for elutrition water from the cooling towers as well as for the emergency and secondary cooling circuits have to be designed only for small amounts of water. (orig./HP)

  5. EVALUATING THE QUALITY OF WATER TREATED BY REDWOOD SLAT TOWER AERATORS

    Science.gov (United States)

    Over a two year period, the U.S. Environmental Protection Agency, Drinking Water Research Division (EPA-DWRD), and two New England water utilities evaluated the water quality from redwood slat tower aerators. Samples of aerator influent and aerator effluent were analyzed for seve...

  6. 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)

  7. Metallic uranium production in water cooled plant

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    A. Ataei

    2009-01-01

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

  9. Sea-water intake tower works for Hamaoka Nuclear Power Station No. 2 Plant

    International Nuclear Information System (INIS)

    It was determined to adopt tunnel system based on the conclusion of negotiation with local people, specifically fishermen, for the sea water intake arrangement in Hamaoka Nuclear Power Station. The main factors for determining the location of the intake tower included marine conditions such as waves and littoral sand drift, and the sea-bottom topographic features and geology of tunnel route, for which field examination, hydraulic experiments and the research and investigation on the method of construction were carried out. These results in the No.2 tower installation at the point 65 m to the east of the No.1 tower. The construction of the tower is described on the manufacture and conveyance of steel caisson, land works at Omaezaki and temporary assembly works on the sea. Then the details of tower installation and the works on site are reported. Fortunately the difficult sea works have been satisfactorily completed earlier than planned, without any accident. The construction facilities utilizing a pilot tunnel seem to have made the better achievement than expected. In spite of the results, the lifting up, off-shore conveyance, and installation of the intake tower caisson, a superheavy structure of weighting up to total 2900 ton, were critical works. (Wakatsuki, Y.)

  10. Variations of parameters on the turbine outlet at nuclear power plant with dissociating coolant and ''dry'' cooling tower

    International Nuclear Information System (INIS)

    The characteristics of the BRGD-1500 and PWR-1300 nuclear power plants with ''dry'' cooling towers under changing meteorological conditions are compared. It is shown that relative variations of specific volume on the turbine outlet for the BRGD-1500 nuclear power plant are appreciably smaller than that for a conventional nuclear power plant steam turbine. As a result, the turbine of a nuclear power plant with dissociating coolant can operate under the wider outside air temperature range without the risk of blade damaging during the turbine exhaust as compared with the nuclear power plant steam turbines

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

    Energy Technology Data Exchange (ETDEWEB)

    Billet, L.

    1994-03-01

    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.

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

    OpenAIRE

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

    1999-01-01

    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 ...

  13. 75 FR 16732 - Action Affecting Export Privileges; Aqua-Loop Cooling Towers, Co.

    Science.gov (United States)

    2010-04-02

    ...DEPARTMENT OF COMMERCE Bureau of Industry and Security Action Affecting...Towers, Co. The Bureau of Industry and Security, U.S. Department...president, writing on Aqua-Loop stationery, responded, that he would...Abgardan, on Aqua- Loop stationery, stating, ``I am...

  14. 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

  15. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  17. Can payments for ecosystem services secure the water tower of Tibet?

    OpenAIRE

    Immerzeel, W.; Stoorvogel, J. J.; Antle, J.

    2008-01-01

    Tibet can be considered as the water tower of Asia and the protection of its water resources crucial. We show that a minimum data approach to model the supply of ecosystem services can potentially be applied to water conservation in Tibet. The approach integrates the spatial heterogeneity of the biophysical environment and the economic behaviour of farmers. A spatially distributed hydrological model is used to simulate the effect of irrigation on evapotranspiration reduction and stream flow e...

  18. 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

  19. Water injection device of cooling water and nuclear reactor

    International Nuclear Information System (INIS)

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

  20. AFCATT (Anti-Fouling Chemical Additive Test Tower)

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-06-01

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

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

    International Nuclear Information System (INIS)

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

  2. Evaporative cooling: water for thermal comfort

    OpenAIRE

    José Rui Camargo

    2008-01-01

    Evaporative cooling is an environmentally friendly air conditioning system that operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists, specifically, in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents three methods that can be used as reference for efficient use of evaporative cooling systems, applying it to several Brazilian cities, characterized by different climat...

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

    Science.gov (United States)

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

    2014-10-01

    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.

  4. Fish-eye view from the water tower towards Jura

    CERN Multimedia

    1977-01-01

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

  5. Air and water cooled modulator

    Science.gov (United States)

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

    1995-01-01

    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.

  6. 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

  7. Operations improvement of the recycling water-cooling systems of sugar mills

    Directory of Open Access Journals (Sweden)

    Shcherbakov Vladimir Ivanovich

    Full Text Available Water management in sugar factories doesn’t have analogues in its complexity among food industry enterprises. Water intensity of sugar production is very high. Circulation water, condensed water, pulp press water and others are used in technological processes. Water plays the main role in physical, chemical, thermotechnical processes of beet processing and sugar production. As a consequence of accession of Russia to the WTO the technical requirements for production processes are changing. The enforcements of ecological services to balance scheme of water consumption and water disposal increased. The reduction of fresh water expenditure is one of the main tasks in economy of sugar industry. The substantial role in fresh water expenditure is played by efficiency of cooling and aeration processes of conditionally clean waters of the 1st category. The article contains an observation of the technologies of the available solutions and recommendations for improving and upgrading the existing recycling water-cooling systems of sugar mills. The authors present the block diagram of the water sector of a sugar mill and a method of calculating the optimal constructive and technological parameters of cooling devices. Water cooling towers enhanced design and upgrades are offered.

  8. Polymeric Materials For Scale Inhibition In Cooling Water Systems

    Directory of Open Access Journals (Sweden)

    Najwa S.Majeed

    2013-04-01

    Full Text Available Calcium carbonate deposition is generally predominant in cooling water-circulating system. For the control of calcium carbonate scale formation two types of polymeric scale inhibitors were used Polyamino polyether methylene phosphonate  (PAPEMPand polyacrylaminde(PAA.Model of cooling tower system have been built up in laboratory scale. Experiments were carried out using different inhibitor concentrations(0.5,1,1.5,2,3ppm ,at water temperature of  40oC and flow rate of 150 l/hr. It was found that Polyamino polyether methylene phosphonate    more effective than polyacryle amide'  as scale inhibitor in all used concentrations and the best inhibition efficiency (95% was at (2.5ppm of Polyamino polyether methylene phosphonate  and (85% with poly acryle amide at concentrations of (3 ppm. The performance of the polymeric scale inhibitors was compared with a method used to control heavy calcium carbonate scale forming by the deposition of sufficiently thin protective calcium carbonate scale using sulfuric acid and depending on Ryznar stability index controlling method. 

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gary Vine

    2010-12-01

    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.

  11. Climate change will affect the Asian water towers.

    Science.gov (United States)

    Immerzeel, Walter W; van Beek, Ludovicus P H; Bierkens, Marc F P

    2010-06-11

    More than 1.4 billion people depend on water from the Indus, Ganges, Brahmaputra, Yangtze, and Yellow rivers. Upstream snow and ice reserves of these basins, important in sustaining seasonal water availability, are likely to be affected substantially by climate change, but to what extent is yet unclear. Here, we show that meltwater is extremely important in the Indus basin and important for the Brahmaputra basin, but plays only a modest role for the Ganges, Yangtze, and Yellow rivers. A huge difference also exists between basins in the extent to which climate change is predicted to affect water availability and food security. The Brahmaputra and Indus basins are most susceptible to reductions of flow, threatening the food security of an estimated 60 million people. PMID:20538947

  12. Materials for advanced water cooled reactors

    International Nuclear Information System (INIS)

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

  13. A Cool Glass of Water

    Science.gov (United States)

    Yang, Li-hsuan

    This case study uses the example of ice in fresh and salt water- in which type of water would ice melt more quickly? The lesson helps students explore the concepts of density, heat transfer, conduction and convection. This material would be appropriate for upper level high school or lower level undergraduate classes. The case study and teaching notes may be downloaded in PDF format. The site also includes a section for instructor feedback where general comments may be read and contributed.

  14. The atmospheric cooling of nuclear power stations

    International Nuclear Information System (INIS)

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

  15. A study on the formation of fouling in a heat exchanging system for Han-river water as cooling water

    International Nuclear Information System (INIS)

    Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When scale deposits in a heat exchanger surface, it is traditionally called fouling. The objective of the present study is to investigate the formation of fouling in a heat exchanging system. A lab-scale heat exchanging system is built-up to observe and measure the formation of fouling experimentally. Water analyses are conducted to obtain the properties of Han river water. In the present study a microscopic observation is conducted to visualize the process of scale formation. Hardness of Han-river water is higher than that of tap water in Seoul

  16. 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

  17. 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

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

    International Nuclear Information System (INIS)

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

  19. Organohalogen products from chlorination of cooling water at nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Bean, R.M.

    1983-10-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Jader D Alean

    2009-01-01

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

  2. Treating cooling pond water for Wabamun Lake level mitigation project in Alberta

    International Nuclear Information System (INIS)

    Dealing with the challenge of recharging Wabamun Lake by treating nearby cooling pond water, fed by the North Saskatchewan River, and returning it to the lake, is discussed. To deal with the problem, TransAlta Utilities constructed a treatment plant in 1997 next to the 2,029 MW Sundance power plant to mitigate the effect the power plant's ongoing and historical effect on the lake's water level. The objective of the treatment plant is to treat cooling pond water and return it to the lake to raise water levels there, which have been significantly reduced over the last 25 years mostly by power plant intake, but also by lack of rainfall, surface runoff, and natural evaporation. At the Treatment Facility the water to be treated is first chlorinated to kill zooplankton, algae and bacteria, followed by adjusting the pH using sulfuric acid. Alum coagulant is used to destabilize colour, particles and colloids. The next step is feeding the water to the Actiflo clarifiers which use microsand to provide increased surface area for floc attachment, and to act as ballast. Clarified water from the Actiflo system is then fed to to the Dusenflo filters to remove the largest particles of suspended solids, and through a finer sand media to remove the remaining turbidity, colour and bacteria. Thiosulfate is used in the ozonation system to inactivate any remaining bacteria and zooplankton in the filtered water, before discharging it to the lake. The cooling towers, which are part of the sye cooling towers, which are part of the system, ensure that the treated water returned to the lake is kept at a constant temperature, varying no more than three degrees C from the lake water temperature. 3 figs

  3. Lifelines Episode 23: Cool Water

    Science.gov (United States)

    APS Communications Office (American Physiological Society Communications Office)

    2009-07-07

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

  4. 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

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

    OpenAIRE

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

    2010-01-01

    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...

  6. 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.

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

    Scientific Electronic Library Online (English)

    Rapeepat, Rungvavmanee; Chantaraporn, Phalakornkule.

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

  8. Water cooled FBNR nuclear reactor

    International Nuclear Information System (INIS)

    Full text: The world with its increasing population and the desire for a more equitable and higher standard of living, is in the search for energy that is abundant and does not contribute to the problem of global warming. The answer to this is a new paradigm in nuclear energy; i.e., through the innovative nuclear reactors that meet the IAEA's INPRO philosophies and criteria that will guarantee the generation of safe and clean energy. The emerging countries to nuclear energy that are not in hurry for energy and look into the future are looking into the participation in the development of such innovative nuclear reactors. They can start developing the non-nuclear components of such reactors in parallel with creating the nuclear infra-structures according to the guidelines of the IAEA suggested in its milestones document. In this way, they can benefit from numerous advantages that the development of a high technology can bring to their countries be it scientific, technological, economic or political. A solution to the present world economic crisis is investing in such projects that contribute to the real economy rather than speculative economy. This will help both local and world economy. One such innovative nuclear reactor is the FBNR that is being developed with the support of the IAEA in its program of Small Reactors Without On-site Refuelling. It is a small (70 MWe) reactor with simple design based on the proven PWR technology (www.sefidvash.net/fbnr). The simplicityy (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 s

  9. Review of supercritical water cooled reactor

    International Nuclear Information System (INIS)

    The supercritical water cooled reactor (SCWR) is essentially light water reactor (LWR) operating at higher pressure and temperature beyond the thermodynamic critical point of water (374 degree C, 22.1 MPa). Compared to current generation LWR, the efficiency of a SCWR can approach 45%. With operation beyord the critical pressure the coolant remains single-phase throughout the system. Thus, recirculation and jet pumps, pressurizer, steam generators, and steam separators and dryers in current LWR are all eliminated. The main mission of the SCWR is generation of low-cost electricity. (authors)

  10. Processing method in ammonia-type condensate desalting device, and water passing tower to be used therefor

    International Nuclear Information System (INIS)

    In a method of conducting an ammonia-type processing for condensates by passing the condensates to a water passing tower of a condensate desalting device filled with an ion exchange resin, passage of water at the water passing tower is interrupted, and aqueous ammonia is passed to the water passing tower in which water passage is interrupted, to eliminate impurities in a mixed ion exchange resin to the outside of the water passing tower, and then condensates are passed again. Drained ammonia blown from the lower portion of the water passing tower upon passage of aqueous ammonia is purified by distillation or by using a deaerating membrane and used again. Namely, the device comprises a mixed ion exchange resin-filled portion having a cation exchange resin and an anion exchange resin therein, a condensate in-flowing tube and an aqueous ammonia in-flowing tube at the upper portion, and a sodium monitoring liquid draining tube, a condensate discharge tube and an aqueous ammonia blowing tube at the lower portion. (I.S.)

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

    International Nuclear Information System (INIS)

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

  12. Anomalous Effects in Air While Cooling Water

    CERN Document Server

    Sardo, Rachel

    2008-01-01

    Water is a unique compound with many anomalies and properties not fully understood. Designing an experiment in the laboratory to study such anomalies, we set up a series of experiments where a tube was placed inside a sealed container with thermocouples attached to the outer surface of the tube and in the air adjacent to the tube. Alternately, deionized water and other compounds were added to the tube and cooled to freezing. Several of the thermocouples suspended in the air and adjacent to the tube showed thermal oscillations as the overall temperature of the container was decreasing. The temperature of the thermocouples increased and decreased in a sinusoidal way during part of the cool down to freezing. Thermal oscillations as large as 3 degrees Celsius were recorded with typical frequencies of about 5 oscillations per minute.

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

    OpenAIRE

    Amir-Samimi

    2013-01-01

    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...

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

    OpenAIRE

    Mohan Kumar, G.; Umesh Sundar, R.

    2012-01-01

    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...

  15. 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

  16. Feasibility of a district cooling system using natural cold water

    Energy Technology Data Exchange (ETDEWEB)

    Jitco, T

    1977-12-01

    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.

  17. Re-routing of cooling water pipeline

    OpenAIRE

    Kuusisto, Tuomas

    2011-01-01

    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...

  18. Supercritical water cooled reactor PSKD-600

    International Nuclear Information System (INIS)

    SCWRs are a class of high temperature, high pressure water-cooled reactors that operate above the thermodynamic critical point of water (374 C, 22.1 MPa or 705 F, 3208 psia). These nuclear steam supply systems may have a thermal or fast neutron spectrum depending upon the specific core design. Both light water and heavy water moderation have also been proposed. Cylindrical as well as spherical fuel elements (i.e., pebble bed) are also being currently considered. It is important to point out that the SCWR is more akin to a gas cooled rather than a light water reactor. The primary system pressure is about 3 times the pressure in a BWR and it operates with a much lower coolant density at a much higher exit temperature than in a BWR. The two-circuit supercritical water cooled reactor plant with the fast neutron spectrum PSKD-600 was considered in this paper. The main problem of this reactor is large positive void effect. Reduction of the void effect was the aim of the previous investigation. The results of the reactor PSKD-600 calculations for core design with the best neutron characteristics are presented in this work. The breeding zone was placed inside the core. Composite SiC/SiC was used as a cladding material Calculations were performed by CONSUL code package. CONSUL code package, developed at the beginning of 90-th for LWR core characteristics calculations, was modified for SCWR type reactors. Reactor core characteristics calculations are carried out on the basis oflculations are carried out on the basis of correlated neutron, isotope and temperature distributions. (orig.)

  19. Supercritical water cooled reactor PSKD-600

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, P.N.; Chibinyaev, A.V.; Frolova, M.V.; Teplov, P.S. [NRC ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

    2012-11-01

    SCWRs are a class of high temperature, high pressure water-cooled reactors that operate above the thermodynamic critical point of water (374 C, 22.1 MPa or 705 F, 3208 psia). These nuclear steam supply systems may have a thermal or fast neutron spectrum depending upon the specific core design. Both light water and heavy water moderation have also been proposed. Cylindrical as well as spherical fuel elements (i.e., pebble bed) are also being currently considered. It is important to point out that the SCWR is more akin to a gas cooled rather than a light water reactor. The primary system pressure is about 3 times the pressure in a BWR and it operates with a much lower coolant density at a much higher exit temperature than in a BWR. The two-circuit supercritical water cooled reactor plant with the fast neutron spectrum PSKD-600 was considered in this paper. The main problem of this reactor is large positive void effect. Reduction of the void effect was the aim of the previous investigation. The results of the reactor PSKD-600 calculations for core design with the best neutron characteristics are presented in this work. The breeding zone was placed inside the core. Composite SiC/SiC was used as a cladding material Calculations were performed by CONSUL code package. CONSUL code package, developed at the beginning of 90-th for LWR core characteristics calculations, was modified for SCWR type reactors. Reactor core characteristics calculations are carried out on the basis of correlated neutron, isotope and temperature distributions. (orig.)

  20. Water treatment in HENDEL cooling water system, (part 1)

    International Nuclear Information System (INIS)

    This report describes a water treatment method for the HENDEL cooling water system. With the data of the corrosion occurred in the pressure vessels of heaters H31, H32 and a cooler C31 for the HENDEL M2-loop, water treatment methods were reviewed. The corrosion rate in these pressure vessels was max. 0.053 mm/year and the pittings found in the heaters H31 and H32 were 0.5 mm - 5 mm in diameter and max. 1.3mm in depth. Moreover, grooving corrosion, which was max. 1.7 mm in depth, was observed at the abutted seam of the heater H32. The main cause of these corrosions may be attributed to irregular operation cycles of the HENDEL cooling water system, and also to inadequacy of water quality for using corrosion inhibitors. By adding polyphosphate with Zn2+ and dispersing agent in corrosion inhibitor, much improvement in preventing corrosion was verified. (author)

  1. Cooling water needs for electrical power plants; Les besoins en eau de refroidissement des centrales thermiques de production d'electricite

    Energy Technology Data Exchange (ETDEWEB)

    Vicaud, A. [Electricite de France (EDF/DPN), 93 - Saint-Denis (France)

    2008-07-01

    Having reviewed the main cooling-water loops on an electrical power plant, as well as the quantities of water needed for cooling, the two main cooling circuits (once-through and recirculation through cooling tower) are presented. Water intake, utilization and thermal discharge are important parameters in terms of water resource. They are factored into optimization studies for the design, operation and maintenance of power plant cooling circuits. While these circuits currently rate among the Best Available Techniques (BAT) for industrial cooling systems, based on the criteria of the IPCC European Directive (Integrated Pollution Prevention and Control Directive 2008/1/EC), efforts are continuously being made to improve their design and operation in order to limit their impact on water resources. (author)

  2. Seismic analysis of 1500 mm diameter heavy water upgrading tower for 500 MWe sites and 235 MWe Kaiga site

    International Nuclear Information System (INIS)

    This report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in the single 1500 mm diameter heavy water upgrading tower for 500 MWe sites and 235 MWe Kaiga site. The analysis of upgrading tower has been carried out for two mutually perpendicular horizontal excitations and the vertical excitation. The upgrading tower has been analysed using beam model taking into account soil-structure interaction. Response spectrum analysis has been carried out using envelop spectra for 500 MWe site and the site spectra for Kaiga. The seismic analysis has been carried out for two cases viz. for tower alone and for tower with supporting structure along with concrete pedestals and raft foundation. The tower has been checked for its stability due to compressive stresses to avoid buckling so that nearby safety related structures are not damaged in the event of SSE loading. The report addresses in detail about the calculation of critical buckling stresses due to various modes of buckling failure and also makes a comparative study of various available international codes in this respect. (author). 15 refs., 20 figs., 18 tabs

  3. Review of high temperature water and steam cooled reactor concepts

    International Nuclear Information System (INIS)

    This review summarizes design concepts of supercritical-pressure water cooled reactors (SCR), nuclear superheaters and steam cooled fast reactors from 1950's to the present time. It includes water moderated supercritical steam cooled reactor, SCOTT-R and SC-PWR of Westinghouse, heavy water moderated light water cooled SCR of GE, SCLWR and SCFR of the University of Tokyo, B-500SKDI of Kurchatov Institute, CANDU-X of AECL, nuclear superheaters of GE, subcritical-pressure steam cooled. FBR of KfK and B and W, Supercritical-pressure steam cooled FBR of B and W, subcritical-pressure steam cooled high converter by Edlund and Schultz and subcritical-pressure water-steam cooled FBR by Alekseev. (author)

  4. Review of High Temperature Water and Steam Cooled Reactor Concepts

    International Nuclear Information System (INIS)

    This review summarizes design concepts of supercritical-pressure water cooled reactors (SCR), nuclear superheaters and steam cooled fast reactors from 1950's to the present time. It includes water moderated supercritical steam cooled reactor, SCOTT-R and SC-PWR of Westinghouse, heavy water moderated light water cooled SCR of GE, SCLWR and SCFR of the University of Tokyo, B-500SKDI of Kurchatov Institute, CANDU -X of AECL, nuclear superheaters of GE, subcritical-pressure steam cooled FBR of KFK and B and W, Supercritical-pressure steam cooled FBR of B and W, subcritical-pressure steam cooled high converter by Edlund and Schultz and subcritical-pressure water-steam cooled FBR by Alekseev. This paper is prepared based on the previous review of SCR2000 symposium, and some author's comments are added. (author)

  5. Statistical performance analysis of salt water cooled pressurized water reactors

    International Nuclear Information System (INIS)

    Pressurized water reactors (PWRs) using salt or brackish cooling water are found to have significant long-term decreases in capacity factors and increases in forced outage rates (FORs) due to equipment failures and maintenance needs. Larger units have significantly lower capacity factors and higher FORs. The significance and magnitude of this correlation increases with unit age. Post-Three Mile Island effects are controlled for

  6. 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

  7. 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 caigher 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.)

  8. Comparative validation of three water cooling coil models

    OpenAIRE

    Gendebien, Samuel; Bertagnolio, Ste?phane; Lemort, Vincent

    2010-01-01

    Water cooling coils are widely used in common HVAC systems. Accurate and robust cooling coil simulation models are required to perform reliable calculations of building cooling needs. Many different cooling coil simulation models were developed during the last decades. The most commonly used cooling coil models are presented and compared in terms of implementation in the first part of the paper. A simplified variable boundary model is presented and comparatively and empirically validated to t...

  9. 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)

    Bernardo José Farah Machado

    2010-11-01

    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.

  10. Condenser tube failures in water-cooled condensers with copper-based alloys

    International Nuclear Information System (INIS)

    Integrity of the condenser is one of the most important prerequisites for optimum availability, reliability and performance of fossil and nuclear units. For many decades, copper-based alloys exclusively were used for condenser tubing. Recently, generic 300 Series stainless steels, proprietary austenitic and ferritic stainless steels, and titanium seem to have completely displaced the traditional copper-based alloys. However, arsenical admiralty brass, arsenical aluminum brass, and 70-30 copper-nickel alloy have been successfully applied in countless applications in units with once-through and circulating cooling tower systems. It is believed that also in the future copper-based alloys will maintain their important position among the condenser tube materials. This contribution focuses on operation experience and the most important types of tube failures in water-cooled condensers with copper-based alloys. (orig.)

  11. 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)

  12. Deposit control in process cooling water systems

    International Nuclear Information System (INIS)

    In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

  13. MIC in Circulating Cooling Water System

    Directory of Open Access Journals (Sweden)

    Li Zhang

    2012-04-01

    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.

  14. Sea water take-up facility for cooling reactor auxiliary

    International Nuclear Information System (INIS)

    The present invention provides an improvement of a cooling sea water take-up facility for cooling auxiliary equipments of nuclear power plant. Namely, an existent sea water take-up facility for cooling reactor auxiliary equipments has at least two circulation water systems and three independent sea water systems for cooling reactor auxiliary equipments. In this case, a communication water channel is disposed, which connects the three independent sea water systems for cooling reactor auxiliary equipments mutually by an opening/closing operation of a flow channel partitioning device. With such a constitution, even when any combination of two systems among the three circulation water systems is in inspection at the same time, one system for cooling the reactor auxiliary equipments can be kept operated, and one system is kept in a stand-by state by the communication water channel upon periodical inspection of water take-up facility for cooling the auxiliary equipments. As a result, the sea water take-up facility for cooling auxiliary equipments of the present invention have operation efficiency higher than that of a conventional case while keeping the function and safety at the same level as in the conventional case. (I.S.)

  15. Improving the environmental cooling for air-coolers by using the indirect- cooling method

    OpenAIRE

    Khmamas, Farhan A.

    2010-01-01

    Air-coolers are widely used as a cheap and convenient method for cooling; however, noise, humidity, smoking, and difficulty in controlling the interior temperature are its major disadvantages. In this research, we suggest using the indirect evaporative cooling method instead of the direct method. In this method the air-cooler is modified to operate as a cooling tower to produce cooling water by the evaporation process; this represents the outdoor unit. The cooled water is pumped to the indoor...

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

    International Nuclear Information System (INIS)

    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 geogry 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.

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

    Science.gov (United States)

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

    2011-07-01

    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.

  18. Advanced cooling technologies

    International Nuclear Information System (INIS)

    Power plant cooling is the major use of water at nearly all thermo-electric generating plants. The withdrawal, consumption and discharge of water for power production raises some of the most contentious siting issues for new plants. This paper will review the major cooling system types and discuss the advantages and disadvantages of each from both the cost/performance and environmental effects viewpoints. Historically, the preferred cooling system for large plants was once-through cooling. In the past few decades, the trend has been to closed-cycle wet cooling to reduce the environmental effects of heated water discharges and large withdrawal rates. More recently, the use of dry and hybrid cooling has been chosen at many sites. The application of dry and hybrid cooling to nuclear plants can introduce design problems not encountered in fossil plants and may lead to the consideration of indirect dry cooling and the reintroduction of natural draft cooling towers. In addition, a number of emerging technologies such as the recovery of water from the plumes of wet cooling towers, the use of inlet air sprays to enhance the performance of dry systems and some innovative approaches to the use of alternative (non-fresh) water supplies may find application in the near future. Some possible research directions for future cooling system improvements are considered. (authors)

  19. Equipment cooling system and sea water cooling system in the after-heat removal system

    International Nuclear Information System (INIS)

    Purpose: To improve the reliability of an emergency diesel generator in the after-heat removal system and of pumps for the equipment cooling system and the sea water cooling system, as well as improve the reliability of the after-heat removal system upon accident to thereby facilitate the cooling for a long time. Constitution: The after-heat removal system of a BWR type reactor actuated upon accident comprises each two equipment cooling systems and sea water cooling systems. For each of the two systems of the equipment cooling system and the sea water cooling system in the after-heat removal system, are provided pipeways for connecting the upstream side of the pumps, pipeways for connecting the downstream sides of the pumps, a pump equipped with an emergency diesel generator independent from the two systems connected with the pipeways and check valves provided at the upstream and the downstream of the pumps. These equipments are controlled in accordance with low pressure water injection mode, reactor container spray mode, pool water cooling mode, steam condensation mode and shutdown cooling mode. (Aizawa, K.)

  20. The spatial scale dependence of water vapor variability inferred from observations from a very tall tower

    Science.gov (United States)

    Pressel, Kyle G.; Collins, William D.; Desai, Ankur R.

    2014-08-01

    Recent studies have established that atmospheric water vapor fields exhibit spatial spectra that take the form of power laws and hence can be compactly characterized by scaling exponents. The power law scaling exponents have been shown to exhibit substantial vertical variability. In this work, Taylor's frozen turbulence hypothesis is used to infer the first-order spatial structure function and generalized detrended fluctuation function scaling exponents for scales between 1 km and 100 km. Both methods are used to estimate the Hurst exponent (H) using 10 Hz time series of water vapor measured at 396 m altitude from an Ameriflux tower in Wisconsin. Due to the diurnal cycle in the boundary layer height at the 396 m observational level, H may be estimated for both the daytime convective mixed layer and the nocturnal residual layer. Values of H? 1/3 are obtained for the convective mixed layer, while values of H> 1/2 apply in the nocturnal residual layer. The results are shown to be remarkably consistent with a similar analysis from satellite-based observations as reported in Pressel and Collins (2012).

  1. iDataCool: HPC with Hot-Water Cooling and Energy Reuse

    OpenAIRE

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

    2013-01-01

    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...

  2. Treating cooling pond water for Wabamun Lake level mitigation project in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2004-05-01

    Dealing with the challenge of recharging Wabamun Lake by treating nearby cooling pond water, fed by the North Saskatchewan River, and returning it to the lake, is discussed. To deal with the problem, TransAlta Utilities constructed a treatment plant in 1997 next to the 2,029 MW Sundance power plant to mitigate the effect the power plant's ongoing and historical effect on the lake's water level. The objective of the treatment plant is to treat cooling pond water and return it to the lake to raise water levels there, which have been significantly reduced over the last 25 years mostly by power plant intake, but also by lack of rainfall, surface runoff, and natural evaporation. At the Treatment Facility the water to be treated is first chlorinated to kill zooplankton, algae and bacteria, followed by adjusting the pH using sulfuric acid. Alum coagulant is used to destabilize colour, particles and colloids. The next step is feeding the water to the Actiflo clarifiers which use microsand to provide increased surface area for floc attachment, and to act as ballast. Clarified water from the Actiflo system is then fed to to the Dusenflo filters to remove the largest particles of suspended solids, and through a finer sand media to remove the remaining turbidity, colour and bacteria. Thiosulfate is used in the ozonation system to inactivate any remaining bacteria and zooplankton in the filtered water, before discharging it to the lake. The cooling towers, which are part of the system, ensure that the treated water returned to the lake is kept at a constant temperature, varying no more than three degrees C from the lake water temperature. 3 figs.

  3. Assessing MODIS GPP in Non-Forested Biomes in Water Limited Areas Using EC Tower Data

    Directory of Open Access Journals (Sweden)

    Flor Álvarez-Taboada

    2015-03-01

    Full Text Available Although shrublands, savannas and grasslands account for 37% of the world’s terrestrial area, not many studies have analysed the role of these ecosystems in the global carbon cycle at a regional scale. The MODIS Gross Primary Production (GPP product is used here to help bridge this gap. In this study, the agreement between the MODIS GPP product (GPPm and the GPP Eddy Covariance tower data (GPPec was tested for six different sites in temperate and dry climatic regions (three grasslands, two shrublands and one evergreen forest. Results of this study show that for the non-forest sites in water-limited areas, GPPm is well correlated with GPPec at annual scales (r2 = 0.77, n = 12; SEE = 149.26 g C?m?2?year?1, although it tends to overestimate GPP and it is less accurate in the sites with permanent water restrictions. The use of biome-specific models based on precipitation measurements at a finer spatial resolution than the Data Assimilation Office (DAO values can increase the accuracy of these estimations. The seasonal dynamics and the beginning and end of the growing season were well captured by GPPm for the sites where (i the productivity was low throughout the year or (ii the changes in the flux trend were abrupt, usually due to the restrictions in water availability. The agreement between GPPec and GPPm in non-forested sites was lower on a weekly basis than at an annual scale (0.44 ? r2 ? 0.49, but these results were improved by including meteorological data at a finer spatial scale, and soil water content and temperature measurements in the model developed to predict GPPec (0.52 ? r2 ? 0.65.

  4. 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

  5. Study on water cooled high conversion reactor

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

    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)

  6. 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

  7. Recycled Towers

    Science.gov (United States)

    Integrated Teaching and Learning Program,

    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.

  8. Results of cooling of dies with water mist

    Directory of Open Access Journals (Sweden)

    R. W?adysiak

    2007-11-01

    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.

  9. Method of injecting cooling water in emergency core cooling system (ECCS) of PWR type reactor

    International Nuclear Information System (INIS)

    Purpose: To provide a cooling water injection method in an ECCS, which can perform effective cooling of the reactor core. Method: In a method of injecting cooling water in an ECCS as a countermeasure against a rupture accident of a pwr type reactor, cooling water in the first pressure storage injection system is injected into the upper plenum of the reactor pressure vessel at a set pressure of from 50 to 90 atg. and a set temperature of from 80 to 2000C, cooling water in the second pressure storage injection system is injected into the lower plenum of the reactor pressure vessel at a pressure of from 25 to 60 atg. which is lower than the set pressure and a temperature less than 600C, and further in combination with these procedures, cooling water of less than 600C is injected into a high-temperature side piping, in the high-pressure injection system of upstroke of 100 atg. by means of a pump and the low-pressure injection system of upstroke of 20 atg. also by means of a pump, thereby cooling the reactor core. (Aizawa, K.)

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

    Energy Technology Data Exchange (ETDEWEB)

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    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.

  11. Ant Tower

    Science.gov (United States)

    Mlot, Nathan; Shinotsuka, Sho; Hu, David

    2010-11-01

    Ants walk via adhesive drops of fluid extruded by their feet. They also use these drops as mortar to build structures such as rafts, bridges and towers, each composed of thousands of ants linked together. We investigate experimentally the construction of triangular ant towers braced by hydrophobic walls. Particular attention is paid to the relationship between tower height and contact angle hysteresis of the wall. We rationalize tower height according to ant adhesion, and tower shape according to the constraints on a column of constant strength.

  12. 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.

  13. Investigation of statistical behavior of nuclear power plant reinforced concrete cooling tower shell due to randomness in material and geometrical parameters using simulation approach

    International Nuclear Information System (INIS)

    In this paper, the response variability of reinforced concrete cooling tower shell due to randomness in material and geometrical parameters is investigated based on the simulation approach by using Monte Carlo simulation. Contrary to the ideal assumption on the shape imperfection such as the axisymmetric cosine shape and/or the cyclic shape imperfections we assume the shape imperfection due to randomness in the geometrical parameters as stochastic field and consider also the material randomness in the elastic modulus of concrete. By assuming correlation between these random parameters, the effect of randomness of these parameters on the response variability is investigated. Based on the analysis on the numerical results, a detailed investigation on the statistical response is given. In particular, the effect of correlation on the response variability in between the random parameters is addressed with which the analysis and design procedures of this structure can be improved. (authors)

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

    Directory of Open Access Journals (Sweden)

    G.MOHAN KUMAR

    2012-07-01

    Full Text Available 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 overcome this drawback, fuzzy linguistics approach is proposed in this paper. This paper shows how QFD approach can be combined with fuzzy logic to resolve some of its drawback. Finally, these two approaches have been compared to know whichapplies the best for this case study.

  15. The influence of Savannah River discharge and changing SRS cooling water requirements on the potential entrainment of ichthyoplankton at the SRS Savannah River intakes

    International Nuclear Information System (INIS)

    Entrainment (i.e., withdrawal of fish larvae and eggs in cooling water) at the SRS Savannah River intakes is greatest when periods of high river water usage coincide with low river dischargeduring the spawning season. American shad and striped bass are the two species of greatest concern because of their recreational and/or commercial importance and because they produce drifting eggs and larvae vulnerable to entrainment. In the mid-reaches of the Savannah River, American shad and striped bass spawn primarily during April and May. An analysis of Savannah River discharge during April and May 1973--1989 indicated the potential for entrainment of 4--18% of the American shad and striped bass larvae and eggs that drifted past the SRS. This analysis assumed the concurrent operation of L-, K-, and P-Reactors. Additional scenarios investigated were: (1) shutting down L- and P-Reactors, and operating K-Reactor with a recycle cooling tower; and (2) shutting down L- and P-Reactors, eliminating minimum flows to Steel Creek, and operating K-Reactor with a recycle cooling tower. The former scenario reduced potential entrainment to 0.7--3.3%, and the latter scenario reduced potential entrainment to 0.20.8%. Thus, the currently favored scenario of operating K-Reactor with a cooling tower and not operating L- and P-Reactors represents a significant lessening of the impact of SRS operations

  16. 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

  17. 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, r 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)

  18. Prototype solar heating and cooling systems, including potable hot water

    Science.gov (United States)

    Bloomquist, D.; Oonk, R. L.

    1977-01-01

    Progress made in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water is reported. The system consists of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition. A comparison of the proposed Solaron Heat Pump and Solar Desiccant Heating and Cooling Systems, installation drawings, data on the Akron House at Akron, Ohio, and other program activities are included.

  19. 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)

  20. 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)

  1. Water-lithium bromide double-effect absorption cooling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

    1980-12-01

    A numerical model was developed for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very-important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy.

  2. 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 kc 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

  3. Use of reclaimed water for power plant cooling.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.; Environmental Science Division

    2007-10-16

    Freshwater demands are steadily increasing throughout the United States. As its population increases, more water is needed for domestic use (drinking, cooking, cleaning, etc.) and to supply power and food. In arid parts of the country, existing freshwater supplies are not able to meet the increasing demands for water. New water users are often forced to look to alternative sources of water to meet their needs. Over the past few years, utilities in many locations, including parts of the country not traditionally water-poor (e.g., Georgia, Maryland, Massachusetts, New York, and North Carolina) have needed to reevaluate the availability of water to meet their cooling needs. This trend will only become more extreme with time. Other trends are likely to increase pressure on freshwater supplies, too. For example, as populations increase, they will require more food. This in turn will likely increase demands for water by the agricultural sector. Another example is the recent increased interest in producing biofuels. Additional water will be required to grow more crops to serve as the raw materials for biofuels and to process the raw materials into biofuels. This report provides information about an opportunity to reuse an abundant water source -- treated municipal wastewater, also known as 'reclaimed water' -- for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Innovations for Existing Plants research program (Feeley 2005). This program initiated an energy-water research effort in 2003 that includes the availability and use of 'nontraditional sources' of water for use at power plants. This report represents a unique reference for information on the use of reclaimed water for power plant cooling. In particular, the database of reclaimed water user facilities described in Chapter 2 is the first comprehensive national effort to identify and catalog those plants that are using reclaimed water for cooling.

  4. Cooling of gas turbines IX : cooling effects from use of ceramic coatings on water-cooled turbine blades

    Science.gov (United States)

    Brown, W Byron; Livingood, John N B

    1948-01-01

    The hottest part of a turbine blade is likely to be the trailing portion. When the blades are cooled and when water is used as the coolant, the cooling passages are placed as close as possible to the trailing edge in order to cool this portion. In some cases, however, the trailing portion of the blade is so narrow, for aerodynamic reasons, that water passages cannot be located very near the trailing edge. Because ceramic coatings offer the possibility of protection for the trailing part of such narrow blades, a theoretical study has been made of the cooling effect of a ceramic coating on: (1) the blade-metal temperature when the gas temperature is unchanged, and (2) the gas temperature when the metal temperature is unchanged. Comparison is also made between the changes in the blade or gas temperatures produced by ceramic coatings and the changes produced by moving the cooling passages nearer the trailing edge. This comparison was made to provide a standard for evaluating the gains obtainable with ceramic coatings as compared to those obtainable by constructing the turbine blade in such a manner that water passages could be located very near the trailing edge.

  5. 77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Science.gov (United States)

    2012-12-07

    ...Water-Cooled Nuclear Power Plants.'' This guide...cooled nuclear power plants. DATES: Submit...currently being developed or improvements...This series was developed to describe and...Water-Cooled Nuclear Power Plants,'' is...

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

    Directory of Open Access Journals (Sweden)

    Srinivas Rachamadagu

    2013-12-01

    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.

  7. Physics of supercritical-pressure light water cooled reactors

    International Nuclear Information System (INIS)

    The concept of direct-cycle, supercritical-water-cooled reactors are developed. Roughly speaking the reactor pressure vessel and control rods are similar to those of PWR, the containment and the safety systems to BWR and the balance of plant to the supercritical-pressure, fossil-fired power plants. Safety principles are similar to those of LWRs, since both are water-cooled reactors. Breeding is possible in tight lattice core. The reactor development will be one way of innovating LWR toward cost reduction. All experiment studies such as corrosion, water chemistry and thermal hydraulics and design optimization and improvements for further cost reduction are remained for the future study. (author)

  8. Development of the interactive model between Component Cooling Water System and Containment Cooling System using GOTHIC

    International Nuclear Information System (INIS)

    In a design point of view, component cooling water (CCW) system is not full-interactively designed with its heat loads. Heat loads are calculated from the CCW design flow and temperature condition which is determined with conservatism. Then the CCW heat exchanger is sized by using total maximized heat loads from above calculation. This approach does not give the optimized performance results and the exact trends of CCW system and the loads during transient. Therefore a combined model for performance analysis of containment and the component cooling water(CCW) system is developed by using GOTHIC software code. The model is verified by using the design parameters of component cooling water heat exchanger and the heat loads during the recirculation mode of loss of coolant accident scenario. This model may be used for calculating the realistic containment response and CCW performance, and increasing the ultimate heat sink temperature limits

  9. Water-cooled units in ultrapower electric arc furnaces

    Science.gov (United States)

    Kuz'min, M. G.; Cherednichenko, V. S.; Bikeev, R. A.; Cherednichenko, M. V.

    2014-12-01

    The thermophysical processes that occur in the skull-metallic pipe-water system under quasistationary and dynamic conditions, when shock heat flows appear, are analyzed. The limiting conditions of water cooling of panels, which are accompanied by the appearance of boiling crisis and pre-emergency and emergency thermophysical processes, are considered.

  10. Heat transfer in helical coils cooled by intensively boiling water

    International Nuclear Information System (INIS)

    The results of experimental investigation of heat transfer in helical coils cooled by intensively boiling water are presented. Dependence of calculation of average in the perimeter coil tubes of heat transfer intensity during intensively bubble water boiling in wide ranges of parameter change is obtained

  11. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  12. Design and construction of immersed tube offshore cooling water tunnels at Sizewell 'B' power station

    International Nuclear Information System (INIS)

    Steam used to drive the turbine generators at Sizewell ''B'' Nuclear Power Station is cooled by passing through condensers where heat is transferred to cool sea water pumped through the Cooling Water System. The paper describes the initial investigations, design, and construction of the offshore tunnels used to draw cool water from 800m offshore and discharge the warmed water 200m offshore. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Michael N. DiFilippo

    2004-08-01

    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. Deliverable 2 focuses on transportation--the largest obstacle to produced water reuse in the San Juan Basin (the Basin). Most of the produced water in the Basin is stored in tanks at the well head and must be transported by truck to salt water disposal (SWD) facilities prior to injection. Produced water transportation requirements from the well head to SJGS and the availability of existing infrastructure to transport the water are discussed in this deliverable.

  14. Assessment of effectiveness of water mist cooling of casting die

    Directory of Open Access Journals (Sweden)

    R. W?adysiak

    2007-12-01

    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.

  15. 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)

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

    OpenAIRE

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

    2010-01-01

    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...

  17. Electricity prices, river temperatures and cooling water scarcity

    OpenAIRE

    Mcdermott, Grant; Nilsen, Øivind Anti

    2012-01-01

    Thermal-based power stations rely on water for cooling purposes. These water sources may be subject to incidents of scarcity, environmental regulations and competing economic concerns. This paper analyses the effect of water scarcity and increased river temperatures on German electricity prices from 2002 to 2009. Having controlled for demand effects, the results indicate that the electricity price is significantly impacted by both a change in river temperatures and the relative abundance of r...

  18. Improvement of water cooling system for LEBRA linac

    International Nuclear Information System (INIS)

    Precise experiments using Free Electron Laser and Parametric X-ray Radiation at the Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University require a high-stability electron beam from the linac. The electron beam energy has been strongly dependent on the temperature of the linac cooling water, although fixed within the error of ±0.1degC. Fluctuation of the temperature was reduced to within ±0.05degC by adjustment of the control parameters for the fine cooling system and improvement of the chill water system. Improvement of the stability of the fine cooling water temperature was very effective for stabilization of the electron energy and the light intensity. (author)

  19. NPP with water cooled reactors operated at supercritical parameters

    International Nuclear Information System (INIS)

    The Generation IV International Forum or GIF, representing ten countries, was initiated in 2000 and formally charged in mid 2001 to lead the collaborative efforts of the world's leading nuclear technology nations to develop next generation nuclear energy systems in order to meet the world's future energy needs. After a deliberation of two years, GIF officials announced the selection of six reactor technologies which they believe represent the future directions in nuclear energy: Gas-Cooled Fast Reactor (GFR), Very-High-Temperature Reactor (VHTR), Supercritical-Water-Cooled Reactor (SCWR), Sodium-Cooled Fast Reactor (SFR), Lead-Cooled Fast Reactor (LFR) and Molten Salt Reactor (MSR). These are selected as based on the criteria of being clean, safe and cost-effective means, of meeting increased energy demands on a sustainable basis, while being resistant to diversion of materials for weapons proliferation and secure to terrorist attacks. They will be the subject of further development. In the present paper, the authors introduce the Supercritical-Water Cooled Reactor (SCWR), a high-temperature, high-pressure water-cooled reactor that operates above the thermodynamic critical point of water (374 deg C and 22.1 MPa). The supercritical water coolant enables a thermal efficiency about one-third higher than current light-water reactors, as well as simplification in the balance of plant. The balance of plant is considerably simplified because the coolant does not change phase because the coolant does not change phase in the reactor and is directly coupled to the energy conversion equipment. In the paper the current projects, the advantages and the difficulties of SCWR technology and their associated Research and Development needs are presented. It is in the authors' intention to present in the future issues of this journal the other five Generation IV reactor technologies. (authors)

  20. Mathematical Modelling of a Low Approach Evaporative Cooling Process for Space Cooling in Buildings

    OpenAIRE

    Nasrabadi, Mehdi; Finn, Donal; Costelloe, Ben

    2012-01-01

    This paper describes a mathematical model of a low approach open evaporative cooling tower for the production of high temperature indirect cooling water (14-16°C) for use in building radiant cooling and displacement ventilation systems. There are several potential approaches to model evaporative cooling, including: the Poppe method, the Merkel method and the effectiveness-NTU (?-NTU) method. A common assumption, applied to the Merkel and ?-NTU methods, is that the effect of cha...

  1. Uranium utilization of light water cooled reactors and fast breeders

    International Nuclear Information System (INIS)

    The better uranium utilization of fast breeder reactors as compared with water cooled reactors is one argument in favour of the breeder introduction. This report tries to quantify this difference. It gives a generally valid formalism for the uranium utilization as a function of the fuel burnup, the conversion rate, fuel cycle losses and the fuel enrichment. On the basis of realistic assumptions, the ratio between the utilizations of breeder reactors to that of light water cooled reactors (LWR) amounts to 180 for the open LWR cycle and 100 in case of plutonium recycling in LWRs

  2. 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.)

  3. Analytical study of falling water film cooling in PCCS

    International Nuclear Information System (INIS)

    The outer side cooling of containment steel vessel by falling water film in the gap of PCCS is studied through numerical simulation. Simplified boundary layer equations for film are solved with transient turbulent elliptic type equations for air/vapor mixed gases, satisfying interface continuity conditions. The effects of wave that occurs on water film surface were indirectly refleted on eddy viscosity model. The heat transfer at interface of falling water film is larger than that of direct steel vessel cooling by buoyancy-induced air flow, which is dominated by surface evaporation of water film. The developed methodology could by utilized to determine the adeuated PCCS design parameters such as water film mass flow rate, gap size. (Author)

  4. Conditioning of cooling water in power stations. Feedback from twenty years of experience with acid feeding

    Energy Technology Data Exchange (ETDEWEB)

    Goffin, C.; Duvivier, L.; Girasa, E. [LABORELEC, Chemistry of Water (Belgium); Brognez, J. [ELECTRABEL, TIHANGE Nuclear Power Station (Belgium)

    2002-07-01

    In the late 1970's and early 1980's, with the development of the nuclear programme in many European countries, the recirculation of cooling water in power stations became an issue which required urgent attention. The concentration of several plants of 1000 MW or more on sites along inland waterways actually made simple once-through cooling impossible, owing to the risk of an unacceptable rise in the river's water temperature. The chemical composition of natural freshwater in western European waterways is such that when it becomes slightly concentrated, scale is rapidly formed. The relatively low solubility of calcium carbonate and the degassing of the carbon dioxide during close contact between the water and air in the heat exchangers of the cooling tower explain this precipitation tendency. Fairly soon, experts in the electricity power generation companies highlighted the need for on-site, pilot loop simulations, in order to foresee the physico-chemical phenomena that could arise in industrial installations. The number of financially justifiable processing possibilities could be briefly summarised by the following three solutions: to adapt the concentration factor in order to be under the calcium carbonate solubility limit and thereby avoid the need for any water conditioning; to accept concentration factors of between 1.4 and 1.9 and control the calcium carbonate precipitation through controlled acid injection in the circulation water; to raise the concentration factor over 5 and soften the makeup water through the addition of lime and flocculant. The last of these solutions was rarely ever used in Belgium and France. It was however widely used in Germany. Its application requires a greater investment and leads to higher operating costs than acid injection. Furthermore, it leads to the problem of daily drying and disposal of several dozen tonnes of sludge, which have to be recycled or dumped. In an increasingly stringent environmental context, this solution is no longer easily justifiable. The research efforts undertaken to better understand and control calcium carbonate precipitation and scale formation have paid off and have resulted in the standardisation of the treatment process and the control procedure of the cooling circuits by ELECTRABEL. The initial experience gained in the fossil power plants of AMERCOEUR (2 x 125 MW units) was finally successfully applied to plants 2 and 3 at TIHANGE. Since then, all of the conventional or combined cycle power plants have adopted the same treatment philosophy. Six units of between 125 and 1000 MW have been treated in this manner, some of them for over twenty years, without showing any signs of scale deposits. It is true that adaptations have had to be made in the control recommendations defined during the pilot trials, in order to allow for the impact of cathodic protections and certain cooling tower fills. (authors)

  5. Conditioning of cooling water in power stations. Feedback from twenty years of experience with acid feeding

    International Nuclear Information System (INIS)

    In the late 1970's and early 1980's, with the development of the nuclear programme in many European countries, the recirculation of cooling water in power stations became an issue which required urgent attention. The concentration of several plants of 1000 MW or more on sites along inland waterways actually made simple once-through cooling impossible, owing to the risk of an unacceptable rise in the river's water temperature. The chemical composition of natural freshwater in western European waterways is such that when it becomes slightly concentrated, scale is rapidly formed. The relatively low solubility of calcium carbonate and the degassing of the carbon dioxide during close contact between the water and air in the heat exchangers of the cooling tower explain this precipitation tendency. Fairly soon, experts in the electricity power generation companies highlighted the need for on-site, pilot loop simulations, in order to foresee the physico-chemical phenomena that could arise in industrial installations. The number of financially justifiable processing possibilities could be briefly summarised by the following three solutions: to adapt the concentration factor in order to be under the calcium carbonate solubility limit and thereby avoid the need for any water conditioning; to accept concentration factors of between 1.4 and 1.9 and control the calcium carbonate precipitation through controlled acid injection in the circulation water; to raise the concentration factor over 5 and soften the makeup water through the addition of lime and flocculant. The last of these solutions was rarely ever used in Belgium and France. It was however widely used in Germany. Its application requires a greater investment and leads to higher operating costs than acid injection. Furthermore, it leads to the problem of daily drying and disposal of several dozen tonnes of sludge, which have to be recycled or dumped. In an increasingly stringent environmental context, this solution is no longer easily justifiable. The research efforts undertaken to better understand and control calcium carbonate precipitation and scale formation have paid off and have resulted in the standardisation of the treatment process and the control procedure of the cooling circuits by ELECTRABEL. The initial experience gained in the fossil power plants of AMERCOEUR (2 x 125 MW units) was finally successfully applied to plants 2 and 3 at TIHANGE. Since then, all of the conventional or combined cycle power plants have adopted the same treatment philosophy. Six units of between 125 and 1000 MW have been treated in this manner, some of them for over twenty years, without showing any signs of scale deposits. It is true that adaptations have had to be made in the control recommendations defined during the pilot trials, in order to allow for the impact of cathodic protections and certain cooling tower fills. (authors)

  6. POOL WATER TREATMENT AND COOLING SYSTEM DESCRIPTION DOCUMENT

    International Nuclear Information System (INIS)

    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

  7. 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

  8. Isolation and identification of legionellosis agents from fishponds, swimming pools and cooling towers in Khuzestan province, Iran

    Directory of Open Access Journals (Sweden)

    Amir Dashti

    2011-10-01

    Full Text Available Introduction and objective: Legionella are the causative agents of pneumonia in human and it is reported that up to 90% cases of legionnaires` disease are due to Legionella pneumophila. These organisms are ubiquitous distributed in natural and man made water sources. They are spread to human by inhalation or aspiration of contaminated aerosols of these sources. We studied some of man made water sources in view of the presence of Legionella, by two methods of culture and PCR. Materials and methods: One hundred and fifty water samples collected from different man made water sources were examined. After acidic treatment of samples, water pellet was inoculated onto buffered charcoal yeast extract agar (BCYE and BMPA (BCYE supplemented with three antibiotics media. Isolated colonies were identified by morphological and biochemical tests. DNA was extracted from the bacteria and was used for PCR technique. DNA pattern of Legionella were identified after electrophoresis of PCR products.Results: Survey of water samples collected from different sources resulted in isolation of Legionella pneumophila (7.3% by culture, and identification of them (15.3% by PCR. The highest isolates of L. pneumophila were from fish ponds in rates of 6.6% by culture and 13.3% by PCR method. Sensitivity and specificity of PCR in this survey were 100% and 95%, respectively. Conclusion: This study showed that legionnaires` disease agents were widely spread in our examined water sources and compared with culture; PCR method has suitable sensitivity and specificity for rapid detection of these organisms in environmental water sources. Significance and impact of the study: The results of this study will increase physicians and microbiologists awareness about spreading of Legionella and this will be useful for control of legionellosis agents.

  9. Water-cooled beam line components at LAMPF

    International Nuclear Information System (INIS)

    The beam line components that comprise the main experimental beam at the Clinton P. Anderson Meson Physics Facility (LAMPF) have been operating since February 1976. This paper will define the functions of the primary water-cooled elements, their design evolution, and our operating experience to the present time

  10. Computational Simulation of a Water-Cooled Heat Pump

    Science.gov (United States)

    Bozarth, Duane

    2008-01-01

    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).

  11. Effect of Cooling Water on Stability of NLC Linac Components

    OpenAIRE

    Pimpec, Fl; Adiga, S.; Asiri, F.; Bowden, G.; Orco, D.; Doyle, E.; Mckee, B.; Seryi, A.; Carter, H.; Boffo, C.

    2002-01-01

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quad...

  12. Trihalomethanes in chlorinated cooling waters of nuclear reactors

    International Nuclear Information System (INIS)

    The Savannah River Plant (SRP) near Aiken, SC has three operating nuclear reactors and used approximately 100-300 kg/day of chlorine to combat reactor heat exchanger biofouling. SRP cooling water is high in organic carbon and following chlorination, the water is occasionally heated to temperatures exceeding 700 C as it passes through the heat exchangers, forming conditions conducive to the formation of trihalomethanes (THMs), which are known human carcinogens. This study was conducted to examine the production and persistence of THMs resulting from the chlorination and heating of SRP reactor cooling waters. The concentration of total THM in all water samples collected in and around the SRP site were less than 59?g/L, and there was no appreciable increase in the concentrations of THM in the Savannah River downstream of the SRP site. THM levels in all cases were below U.S. Environmental Protection Agency drinking water guidelines (100 ?g/L), and it was concluded that THM levels resulting from the chlorination of reactor cooling water at the SRP were insignificant

  13. 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.

  14. 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

  15. Procedure for operating a heavy water cooled power reactor

    International Nuclear Information System (INIS)

    Nuclear reactors cooled by heavy water usually have equipment for fuel element exchange during operation, with the primary circuit remaining contained. This fuel element exchange equipment is expensive and complicated in many respects. According to the invention, the heavy water is therefore replaced by light water after a certain time of operation in such way that light water is led in and heavy water is led off. After the replacement, at least a quarter of the fuel elements of the reactor core is exchanged with the reactor pressure vessel being open. Then the light water serving as a shielding is replaced by heavy water, with the reactor pressure vessel being closed. The invention is of interest particularly for high-conversion reactors. (orig.)

  16. Main parameters of foreign boiling water cooled reactors

    International Nuclear Information System (INIS)

    Peculiarities and main parameters of channel- and tank-type boiling water cooled power reactors, their steam separators, as well as emergency core cooling systems and systems for accident aftereffect localization are considered using as examples power units with BWR reators at the susquehana NPP (BWR-4, USA), the River Bend NPP (BWR-6, USA), developed project for ABWR boiling reactor and channel-type reactors at the Fugen NPP (Japan) and SGHWR (Great Britain). Design and main parameters of fuel assemblies, techniques for reactivity and power distribution control and monitoring methods are described. All the reactors considered, including channel type ones, have hermetic protective shell designed for not high excessive pressure

  17. 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

  18. Special cooling systems for research nuclear reactors

    International Nuclear Information System (INIS)

    In the 1950s research nuclear reactors were built in several Comecon countries. These reactors were supplied with secondary cooling circuits applying wet cooling towers. In the eighties a reconstruction has become timely, through which the reactors' output could substantially be increased, requiring a considerable extension of the cooling systems. The paper deals with two cases where the investor decided to build dry cooling towers for the reconstruction falling due between 1987-1990. Dry cooling systems of similar capacity have been operating since several decades in various branches of industry, but here, due to the special field of application, requirements other than usual had to be complied with, e.g.: pressure control during operation and in standstill; constant temperature of cooling water; increased frost protection; and decreased noise level. Describing the two cooling systems established, the paper provides detailed information on the said requirements and the technical arrangements taken to meet them

  19. Thermal hydraulic modeling of integrated cooling water systems

    International Nuclear Information System (INIS)

    Thermal hydraulic modeling of cooling water systems has been extended to multiple system configurations with heat exchangers as interface components between systems. The computer program PC-TRAX has been used as the basic tool for the system simulation. Additional heat exchanger modules have been incorporated to accurately predict the thermal performance of systems for the design as well as off-design conditions. The modeling accommodates time-dependent changes in conditions, temperature and pressure controllers, and detailed physical parameters of the heat exchangers. The modeling has been illustrated with examples from actual plant systems. An integrated system consisting of Spent Fuel Pool, Primary Component Cooling Water, and Service Water System has been successfully modeled to predict their performance under normal operations and emergency conditions. System configurations are changed from the base model by using a command module

  20. 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)

  1. The selection and testing of plastic tower fill

    International Nuclear Information System (INIS)

    The Paducah Gaseous Diffusion Plant operates four recirculating water loops to control the temperature of the uranium enrichment process. In 1973, the performance of four counterflow towers was significantly improved when the aging wooden slat fill was replaced with 130,000 cubic feet of asbestos paper cellular fill. In anticipation of a need to make another fill change at some future date, a program was initiated to maintain an awareness of new fill products and investigate their physical durability. The problems that had been encountered in obtaining large quantities of asbestos paper fill and the development and availability of plastic fill led the Technical Services Division of the Paducah Plant into a long-term study of plastic cooling tower fill. The form of the program evolved from investigations of materials and the heat resistance of fill products to measurement of the tower fill temperature gradients and analysis of potential heat loads

  2. 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

  3. 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

  4. Water Cooled TJ Dense Array Modules for Parabolic Dishes

    International Nuclear Information System (INIS)

    AZUR SPACE Solar Power GmbH has developed a novel type of dense array module for use in parabolic dishes. Such dishes never produce a perfectly homogeneous, rectangular light spot but an inhomogeneous light distribution. A regular module would use this light distribution very inefficiently. Therefore AZUR SPACE developed a dense array module concept which can be adapted to inhomogeneous light spots. It is populated with state of the art triple junction solar cells.The modules are designed for light intensities in the range of 50-100 W/cm2 and are actively water cooled. Prototypes are installed in 11 m2 parabolic dishes produced by Zenith Solar. A peak output of 2.3 kW electrical and 5.5 kW thermal power could be demonstrated. The thermal power may be used for solar heating, solar cooling or warm water.

  5. 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

  6. Results of cooling of dies with water mist

    OpenAIRE

    W?adysiak, R.; Pietrowski, S.

    2007-01-01

    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 ...

  7. Advanced technologies for water cooled reactors 1990. Pt. 1

    International Nuclear Information System (INIS)

    The meeting was attended by 20 participants from 12 countries who reviewed and discussed the status and progress of national programmes on advanced water-cooled reactors and recommended to the Scientific Secretary a comprehensive programme for 1991/1992 which would support technology development programmes in IWGATWR Member States. This summary report outlines the activities of IWGATWR since its Second Meeting in June 1988 and main results of the Third Meeting

  8. CLASSIFICATION OF THE MGR POOL WATER TREATMENT AND COOLING SYSTEM

    International Nuclear Information System (INIS)

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) pool water treatment and cooling system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  9. Blow down of sub-cooled water through orifices

    International Nuclear Information System (INIS)

    The calculation of the blow down rates of single and two-phase water from the pipes, nozzles and orifices are practically important in the safety analysis of the water cooled reactors. Accurate prediction of the discharge flow rates is required to estimate the rate of system depressurization and corresponding heat transfer rate under different flow regimes in the core during a SBLOCA. The estimation of the blow down rates and the system behavior influences the design of the emergency core cooling systems and the containment pressure suppression systems. In this work, the blow down rate data are generated for water at sub-cooled and near saturated conditions through sharp edged orifices of various sizes ranging from 3.5 mm to 7.0 mm at high temperature (250? to 300?) and pressure (65 to 110 bar) in the high temperature loop at Kalpakkam. The data were compared with the results of the analysis by the code Relap5/Mod 3.2

  10. Cooled sea water releasing device for nuclear power plant

    International Nuclear Information System (INIS)

    In a water releasing device for releasing warm sea water after cooling in a coastal nuclear power plant from a reservoir disposed higher than the sea level in a full tide by way of a syphon pipe, an ejector device is disposed for drawing air at the top of the syphon pipe into the releasing water flow by the flowrate thereof. Since the warm sea water is released below the surface of the sea directly by way of the syphon tube beyond a bank, collision of the released water flow against the surface of the sea is not caused, so that the air is not involved to the sea water by collision. Accordingly, even when a great amount of warm sea water is released continuously from a high position, the amount of air bubbles generated on the surface of the sea where the water is released in small, and there is no worry of causing cloudy state of the sea water in the vicinity thereof. Even if air is going to stay in a air sump at the inner top of the syphon pipe, since it is drawn and discharged by the energy of the released water flow by the ejector, there is no worry of interrupting the drawing state of the syphon. (N.H.)

  11. 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

  12. Ecotoxicological investigation in cooling water reservoirs of NPP and Dnepr cascade water reservoirs by using biotest

    International Nuclear Information System (INIS)

    Investigation data obtained during 1988-1992 have shown that NPP waste waters effected test-organisms: they induced changes in growth intensity and morphology of Spirodela polyrrhiza and high mortality of spawn and larvae of Salmo gairdneri as well as somatic mutations and mortality in Tradescantia SLC system. It indicates that toxic matters discharge to cooling reservoirs with NPP waste waters. Similar levels of toxicity and genotoxicity were found in Ignalina and Leningrad NPP waste waters, as well as in cooling reservoirs waters. The water of Dnepr cascade reservoirs was more eutrophic, toxic and genotoxic than the water of NPP cooling reservoirs. Water genotoxicity in the Dnepr cascade water reservoirs was equal to that of NPP waste waters. The Kiev reservoir water showed the highest genotoxicity.Bottom sediments of some biotopes of Kiev and Kachovsk water reservoirs were found to be the most genotoxic. The genotoxicity of these bottom sediments was equal to the Ignalina NPP EDS waste water treatment plant sludge, which commonly is utilized as hazardous waste. The use of test-organism system allows to estimate more precisely ecotoxicological situation in water reservoirs - to establish their eutrophic level, to identify radioactive and chemical water and bottom sediments pollution and to reveal synergetic effects of pollutant complex effect. 8 refs., 6 tabs

  13. 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 characteristicsorm 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)

  14. Microbial Quality of Cool Water Washed Shell Eggs

    OpenAIRE

    Jones, D. R.; Musgrove, M. T.; Caudill, A. B.; Curtis, P. A.; Northcutt, J. K.

    2005-01-01

    A study was conducted to examine the effects of cool water washing on the microbial quality of shell eggs. Six dual tank wash water temperature schemes were examined for their ability to reduce naturally occurring aerobic bacteria and inoculated Salmonella Enteritidis (SE). The wash water schemes were: T1= 48.9oC; T2 = 48.9oC, 23.9oC; T3 = 48.9oC, 15.6oC; T4 = 23.9oC; T5 = 15.6oC; and T6 = 23.9oC, 15.6oC. All wash water tanks were maintained from 10.5-11.5 pH throughout the study. Eg...

  15. Nuclear analysis of DEMO water-cooled blanket based on sub-critical water condition

    International Nuclear Information System (INIS)

    Highlights: ? For sub-critical water condition, the size of cooling loop would be more longer, for example, 2 m. ? Local TBR is related to the material fraction of breeders and multipliers, the beryllium is the dominant. ? Front area of blanket is dominant for blanket design and it would contribute the most of TBR comparing to the backside zones. - Abstract: For the water-cooled solid blanket of DEMO, the nuclear analysis was performed based on present cooling piping system. Especially, distributions of neutron load and temperature were calculated with Pn is 5 MW/m2. Furthermore, the local TBR was optimized by changing the material proportion for each Pn level (1–5 MW/m2). It was confirmed that the size of cooling loop for sub-critical water could be used as about 2000 × 450 mm and the cooling pipe diameter of D is 12 mm, d is 9 mm at v is 5.36 m/s. The pipe pitches would vary with Pn level which is related to the blanket structure design. Nuclear heat distribution is the base to decide the distribution of cooling pipe positions. It was found that the local TBR of blanket would be dropped down along with the Pn level rising which was mainly depended on the thickness of beryllium variation. Finally, the layout of cooling pipes for each level was obtained.

  16. What causes cooling water temperature gradients in forested stream reaches?

    Science.gov (United States)

    Garner, G.; Malcolm, I. A.; Sadler, J. P.; Hannah, D. M.

    2014-06-01

    Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperature and provide refugia for temperature sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts, or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts, and in the absence of potentially confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian landuse transitions from open moorland to semi-natural forest. Observations were made along a 1050 m reach using a spatially-distributed network of ten water temperature micro-loggers, three automatic weather stations and >200 hemispherical photographs, which were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model, incorporating flow-routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water column-atmosphere interface. Predominantly net energy gains occurred along the reach during daylight hours, and heat exchange across the bed-water column interface accounted for skies), differences between water temperature observations decreased in the streamwise direction; a maximum difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ?1°C cooler than at the upstream reach boundary and lagged the occurrence of daily maximum water temperature upstream by >1h. Temperature gradients were not generated by cooling of stream water, but rather by a combination of reduced rates of heating in the woodland reach and advection of cooler (overnight and early morning) water from the upstream moorland catchment. Longitudinal thermal gradients were indistinct at night and on days when net radiation gains were low (under over-cast skies), thus when changes in net energy gains or losses did not vary significantly in space and time, and heat advected into the reach was reasonably consistent. The findings of the study and the modelling approach employed are useful tools for assessing optimal planting strategies for mitigating against ecologically damaging stream temperature maxima.

  17. Chemical treatment of slime in industrial cooling water systems

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Noriyuki

    1987-07-01

    Chemical suppression test was made for slime produced in pipes of the industrial water cooling systems. The 3 month chemical slime treatment test in 1984 proved to be effective, and the test has been carried out since July, 1985. The objective was to suppress the generation of slime by decreasing the number of general bacteria by slime treatment agent (fungicide of chloride group). The number of bacteria in the supplied water was compared for the time and day of the week when samples were collected. It was found that there was no regular rule in the variation of the number of bacteria, with measured result of 30-10/sup 6/ variation range. From the variation in the number of bacteria and the sticking conditions of slime on the test board, it became clear that suppression was possible by drastically decreasing the bacteria number in cooling water in the early stage of chemical supply, followed by resupply of treatment agent in a week when the bacteria would be restored to its original amount by supplied water. However, the method is to suppress the slime generation, and is unable to stop the generation completely. (9 figs, 3 tabs)

  18. IMPROVEMENT IN CONVENTIONAL WATER JACKET METHOD IN MOULD COOLING USING HEAT PIPE

    OpenAIRE

    Shelke, R. S.; Borkar, Sulas G.

    2012-01-01

    Die casting moulds and injection moulding are cooled by conventional water jacket method. Cooling of mould is very essential for the purpose of quality of parts and cycle time. The conventional water jackets methods used are having many disadvantages, due to which the effect of mould cooling is not optimum. Hence a technique which can overcome all the disadvantages and become optimum emerged. The main aim of this proposed work is to improve conventional water jackets methods in mould cooling ...

  19. Evaluation of corrosion inhibitors for component cooling water systems

    International Nuclear Information System (INIS)

    Electrochemical techniques were used to study the inhibition effects of molybdate (MoO42-), MoO42- + nitrite (NO2-), MoO42- + tolyltriazole (TTA, CH3C6H4N3H), and MoO42- + NO2- + TTA on the general and pitting/crevice corrosion of carbon (C) steel and some copper (Cu) alloys common to component cooling water systems (CCWS) exposed to deionized water open to ambient air or purged with nitrogen (N2). Some tests were performed in deionized water faulted with chloride (Cl-) at concentrations of 150 ppb or 1.5 ppm and with 1.5 ppm Cl- plus 1.5 ppm sulfate (SO42-). Results were compared with the inhibition effects of 200 ppm chromate (CrO42-)

  20. Application of radiant cooling as a passive cooling option in hot humid climate

    Energy Technology Data Exchange (ETDEWEB)

    Vangtook, Prapapong; Chirarattananon, Surapong [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

    2007-02-15

    In hot and humid region, air-conditioning is increasingly used to attain thermal comfort. Air-conditioning is highly energy intensive and it is desirable to develop alternative low-energy means to achieve comfort. In a previous experimental investigation using a room equipped with radiant cooling panel, it was found that cooling water kept to 25{sup o}C could be used to attain thermal comfort under some situations, while water at such temperature would not cause condensation of moisture from air on the panel. This paper reports results of a series of whole-year simulations using TRNSYS computer code on applications of radiant cooling to a room model that represents the actual experimental room. Admitting the inability of radiant cooling to accept latent load, chilled water at 10{sup o}C was supplied to cooling coil to precool ventilation air while water cooled by cooling tower was used for radiant cooling in daytime application. For night-time, cooling water from cooling tower supplied for radiant cooling was found to be sufficient to achieve thermal comfort. Such applications are considered to be more amenable to residential houses. (author)