Analysis of Mechanical-Draught Counterflow Air/Water Cooling Towers

1983 ◽  
Vol 105 (3) ◽  
pp. 576-583 ◽  
Author(s):  
J. W. Sutherland
Keyword(s):  
Water Loss ◽  
Driving Force ◽  
Cooling Tower ◽  
Computer Programs ◽  
Common Method ◽  
Cooling Towers ◽  
Approximate Analysis ◽  
Water Cooling ◽  
Accurate Analysis

This paper compares an accurate analysis of mechanical draught counterflow cooling towers, including water loss by evaporation, with the approximate common method based on enthalpy driving force developed by Merkel in 1925. Computer programs were developed for both the accurate analysis (TOWER A) and the approximate analysis (TOWER B). Substantial underestimates of tower volume of from 5 to 15 percent are obtained when the approximate analysis is used, indicating the possibility of quite serious consequences as far as cooling tower design is concerned. Computer predictions of cooling tower integral are shown to compare well with published values.

scholarly journals Theoretical and experimental study of a cross-flow induced-draft cooling tower

2009 ◽  
Vol 13 (4) ◽  
pp. 91-98
Author(s):  
Elazm Abo ◽  
Farouk Elsafty
Keyword(s):  
Experimental Study ◽  
Cooling Tower ◽  
Characteristic Curve ◽  
Cross Flow ◽  
Hot Water ◽  
Proper Solution ◽  
Cooling Towers ◽  
Water Cooling ◽  
Transfer Coefficients ◽  
Experimental Rig

The main objective of this study is to find a proper solution for the cross-flow water cooling tower problem, also to find an empirical correlation's controlling heat and mass transfer coefficients as functions of inlet parameters to the tower. This is achieved by constructing an experimental rig and a computer program. The computer simulation solves the problem numerically. The apparatus used in this study comprises a cross-flow cooling tower. From the results obtained, the 'characteristic curve' of cross-flow cooling towers was constructed. This curve is very helpful for designers in order to find the actual value of the number of transfer units, if the values of inlet water temperature or inlet air wet bulb temperature are changed. Also an empirical correlation was conducted to obtain the required number of transfer units of the tower in hot water operation. Another correlation was found to obtain the effectiveness in the wet bulb operation.

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

2009 ◽  
Vol 8 (1) ◽  
pp. 92-100 ◽  
Author(s):  
Stacey Foong Yee Yong ◽  
Fen-Ning Goh ◽  
Yun Fong Ngeow
Keyword(s):  
Dna Sequencing ◽  
Legionella Pneumophila ◽  
Cooling Tower ◽  
Latex Agglutination ◽  
Cooling Towers ◽  
Water Cooling ◽  
Public Health Policies ◽  
Legionella Species ◽  
Repeat Sampling ◽  
East West

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

scholarly journals THE WAYS OF RATIONAL USE OF COOLING TOWERS

2020 ◽  
Vol 2020 (3) ◽  
pp. 180-187
Author(s):  
D Muhiddinov ◽  
◽  
S Sanayev ◽  
B Boliyev
Keyword(s):  
Water Use ◽  
Cooling Tower ◽  
Water Supply Systems ◽  
Cooling Towers ◽  
Water Cooling ◽  
Efficiency And Effectiveness ◽  
Recycling Systems ◽  
Almost All ◽  
Bodies Of Water ◽  
Supply Systems

In order to improve the economic performance of the company, the establishment of rational water use schemes and the reduction of the use of fresh water obtained from water supply systems or natural bodies of water can become an important factor. Water-cooling circulating systems, where cooling towers are used as cooling facilities, are the basis of rational water use systems. In water recycling systems that need stable water cooling at high specific hydraulic and thermal loads, cooling towers are used. By spraying water with nozzles or irrigation devices, the surface of water needed to cool it by contact with air is formed. A cooling tower is a heat exchange device for removing heat from various production processes to the environment by evaporating part of the water passing through it. The share of evaporated water usually does not exceed 1.5 %. Most of the cooling towers used were built 30 - 50 years ago. Almost all of these installations are morally and physically outdated. To consider the main criteria that should be guided with the choice of method for reconstruction of cooling towers to increase the efficiency and effectiveness of their operation.

scholarly journals Impact of Weather Conditions on the Operation of Power Unit Cooling Towers 905 MWe

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6412
Author(s):  
Zbigniew Buryn ◽  
Anna Kuczuk ◽  
Janusz Pospolita ◽  
Rafał Smejda ◽  
Katarzyna Widera
Keyword(s):  
Power Unit ◽  
Air Temperature ◽  
Cooling Tower ◽  
Cooling Water ◽  
Weather Conditions ◽  
Cooling Towers ◽  
Cooling Efficiency ◽  
Water Cooling ◽  
Water Losses ◽  
Water Stream

The paper presents the results of measurements and calculations concerning the influence of weather conditions on the operation of wet cooling towers of 905 MWe units of the Opole Power Plant (Poland). The research concerned the influence of temperature and relative humidity of air, wind and power unit load on the water temperature at the outlet from the cooling tower, the level of water cooling, cooling efficiency and cooling water losses. In the cooling water loss, the evaporation loss stream and the drift loss stream were distinguished. In the analyzed operating conditions of the power unit, for example, an increase in Tamb air by 5 °C (from 20–22˚C to 25-27˚C) causes an increase in temperature at the outlet of the cooling tower by 3-4˚C. The influence of air temperature and humidity on the level of water cooling ΔTw and cooling efficiency ε were also found. In the case of ΔTw, the effect is in the order of 0.1-0.2˚C and results from the change in cooling water temperature and the heat exchange in the condenser. The ε value is influenced by air temperature and humidity, which determine the wet bulb temperature value. Within the range of power changes of the unit from 400 to 900 MWe, the evaporated water stream mev, depending on the environmental conditions, increases from 400-600 tons/h to the value of 1000-1400 tons/h. It was determined that in the case of the average power of the unit at the level of 576.6 MWe, the average values of the evaporation and drift streams were respectively 0.78% and 0.15% of the cooling water stream. Using statistical methods, it was found that the influence of wind on the level of water cooling, cooling efficiency and cooling water losses was statistically significant.

scholarly journals Energy resource efficient designs of small-sized devices for recycled water cooling

2020 ◽  
Vol 12 (6) ◽  
pp. 339-348
Author(s):  
K.E. Bondar ◽  
N.S. Shulaev ◽  
S.P. Ivanov ◽  
S.V. Laponov
Keyword(s):  
Mass Transfer ◽  
Power Law ◽  
Cooling Tower ◽  
Air Flow ◽  
Vertical Component ◽  
Energy Resource ◽  
Laboratory Research ◽  
Cooling Towers ◽  
Water Cooling ◽  
Recycled Water

Introduction. To use natural sources in rational way, plantsof continuous cooling of closed systems of recycling water supply are used. The paper presents designs of small-sized devices for recycling water cooling which are energy resource effective due to twisted motion of air flow, moving countercurrent to the cooled water. Heat and mass transfer is a nanotechnological process that occurs at the intermolecular level. Methods and materials. Countercurrent mini cooling towers are widely used in all industries,but there are some disadvantages, the main of which is the insufficient interaction time of the moving phases. Screw motion of air flow is created by the tangential supply of cooling air in the bottom part of cylindrical small-sized cooling tower. The rate of rotary motion decreases as air flow moves up in cooling towers, and vertical parameter of the rate – increases. Such scheme of the air flow motionmakes it possible to decrease average vertical parameter of the rate and to increase phases contact time. Laboratory research. To determine the technological and hydroaerothermal characteristics, as well as to estimate the efficiency of cooling recycled water, and to carry out mass-heat exchange at the intermolecular stagean experimental facility of small-sized cooling tower with twisted air flow has been developed. Conclusions. In accordance with the exponential law it is shown that the rotational component decreases at increasing height, and in accordance with the power law the vertical component increases component with the exponent ~1,79. It is determined that moisture content x and air temperature tv in the volume of the height of the sprinkler varies according to a power law, in particular for a screw cooling tower proportionally x ~ h0,83, t в ~ h1,25. It was determined that the coefficients of mass transfer βxv and heat transfer αv of a mini cooling tower with twisted air flow at the intermolecular level with equal irrigation densities are 20% higher than the coefficients of a mini cooling tower with counter-current flow. Also it has been determined experimentally a dependence of aerodynamics resistance coefficient of the twisted irrigator of the cooling tower on criterium Refor air flow, and it was determined that it decreases like Re–K2 as the exponent K2 varies in the range 0.114÷0.193 depending on the irrigation density

Water Consumption of Cooling Towers in Different Climatic Zones of the U. S.

2015 ◽  
Author(s):  
Daniele Ludovisi ◽  
Ivo A. Garza
Keyword(s):  
Water Consumption ◽  
Cooling Tower ◽  
Cooling Towers ◽  
Water Cooling ◽  
Outdoor Air ◽  
Software Suite ◽  
Climatic Zones ◽  
Local Climate ◽  
Commercial Applications ◽  
Mass Transfers

Cooling towers are widely used across a range of industries and represent the largest reuse of water in industrial and commercial applications. While continually recycling water, cooling towers loose significant inventory through evaporation and blowdown. The local climate strongly affects the efficiency of a cooling tower and its water consumption. This paper discusses the performance of cooling towers in different climatic zone of the U.S. considering the seasonal variations of outdoor air temperature, wind speed and solar radiation. The analyses are carried out with the Sargent & Lundy’s software suite UHS which simulates the transient heat and mass transfers occurring in cooling tower/basin systems.

Case study: Theoretical calculation model and variable condition analysis research on the water-splashing noise for natural draft wet cooling towers

2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun
Keyword(s):  
Theoretical Model ◽  
Sound Pressure Level ◽  
Water Droplet ◽  
Water Distribution ◽  
Sound Pressure ◽  
Cooling Tower ◽  
Distribution Patterns ◽  
Calculation Model ◽  
Pressure Level ◽  
Cooling Towers

Based on the basic theory of water droplets impact noise, the generation mechanism and calculation model of the water-splashing noise for natural draft wet cooling towers were established in this study, and then by means of the custom software, the water-splashing noise was studied under different water droplet diameters and water-spraying densities as well as partition water distribution patterns conditions. Comparedwith the water-splashing noise of the field test, the average difference of the theoretical and the measured value is 0.82 dB, which validates the accuracy of the established theoretical model. The results based on theoretical model showed that, when the water droplet diameters are smaller in cooling tower, the attenuation of total sound pressure level of the water-splashing noise is greater. From 0 m to 8 m away from the cooling tower, the sound pressure level of the watersplashing noise of 3 mm and 6 mm water droplets decreases by 8.20 dB and 4.36 dB, respectively. Additionally, when the water-spraying density becomes twice of the designed value, the sound pressure level of water-splashing noise all increases by 3.01 dB for the cooling towers of 300 MW, 600 MW and 1000 MW units. Finally, under the partition water distribution patterns, the change of the sound pressure level is small. For the R s/2 and Rs/3 partition radius (Rs is the radius of water-spraying area), when the water-spraying density ratio between the outer and inner zone increases from 1 to 3, the sound pressure level of water-splashing noise increases by 0.7 dB and 0.3 dB, respectively.

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