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

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.

1978 ◽  
Vol 100 (3) ◽  
pp. 520-526 ◽  
Author(s):  
J. M. Bentley ◽  
T. K. Snyder ◽  
L. R. Glicksman ◽  
W. M. Rohsenow

An advanced wet/dry heat transfer surface has been developed for power plant cooling towers eliminating the need for conventional dry surface. Hot water to be cooled is channeled down grooves in the surface; the balance of the surface is dry and acts like a fin. The cooling air passes over the surface in cross-flow. Since the grooves occupy only a small fraction of the surface area, a majority of the heat transfer is by sensible heat transfer. In the experimental apparatus the wet surface area was five percent of the total area and the heat transfer by evaporation varied between 20 and 40 percent of the total heat transfer. An analytical model indicated that the yearly water consumption of a cooling tower with the new wet/dry surface would be less than half that of a conventional wet cooling tower and fog plumes would be eliminated.


2013 ◽  
Vol 7 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Ramkumar Ramkrishnan ◽  
Ragupathy Arumugam

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.


Author(s):  
S. Pal ◽  
L. J. Peltier ◽  
A. Rizhakov ◽  
M. P. Kinzel ◽  
M. H. Elbert ◽  
...  

The performance of cooling towers, whether operating by themselves, or in close vicinity of other cooling towers can be adversely affected by the re-ingestion of the cooling tower discharge into the tower intakes. The recirculation of the discharge from a wet cooling tower raises the wet bulb temperature of the air entering a wet cooling tower. Current design strategies, often account for this discharge re-ingestion issue, through a conservative adjustment to the far field ambient wet bulb temperature to calculate the actual intake wet bulb temperature. Critical applications, such as those related to nuclear safety applications where there is concern about cooling tower performance, may require more accurate and comprehensive assessment of the recirculation and dispersion of cooling tower discharge. Gaussian plume models alone are of limited use when dealing with discharges in the vicinity of large structures. This paper discusses the use of a computational fluid dynamics approach to evaluate worst case discharge recirculation effects in cooling towers. The bounding design values of tower intake wet bulb temperature increase due to recirculation (ingestion of tower’s own discharge), and interference (ingestion of another interfering tower’s discharge), are calculated considering the various conditions of cooling tower operation, ambient temperature, humidity and wind conditions. The RANS CFD model used in the study is evaluated against published experimental data for flow over bluff bodies at high Reynolds numbers, and experimental data on buoyant jets in cross flow.


2009 ◽  
Vol 8 (1) ◽  
pp. 92-100 ◽  
Author(s):  
Stacey Foong Yee Yong ◽  
Fen-Ning Goh ◽  
Yun Fong Ngeow

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.


2020 ◽  
Vol 329 ◽  
pp. 03007
Author(s):  
Ilnur Madyshev ◽  
Ildar Sabanaev ◽  
Vitaly Kharkov ◽  
Lenar Ganiev ◽  
Andrey Dmitriev

Biofouling can significantly deteriorate the efficiency of cooling towers. A cooling tower with a three-flow cooling circuit has been developed. The fill pack consists of inclined-corrugated contact elements with perforation. One of the advantages of the proposed cooling tower is the possibility of uniform distribution of liquid over the cross-sectional area. The paper represents the results of an experimental study of the thermal performance of the three-flow cooling tower. It was found that when the wetting rate of the liquid increases, the thermal performance of the cooling tower can reach 47.8%. The developed three-flow cooling tower allows excluding the propagation of microorganisms and reducing the biofouling of industrial water systems along with the high performance for circulating water.


2020 ◽  
Vol 2020 (3) ◽  
pp. 180-187
Author(s):  
D Muhiddinov ◽  
◽  
S Sanayev ◽  
B Boliyev

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.


2015 ◽  
Vol 766-767 ◽  
pp. 505-510 ◽  
Author(s):  
J. Jayaprabakar

The cooling water system is the industry’s primary way of conserving water. Modern water cooling towers were invented during the industrial age to dissipate heat when natural cooling water sources were available. The origin of cooling towers made the plant site selection independent of the availability of water source. The development of new, high efficiency film fills produced from light weights, flame retarded PVC reduces the size and weight of cross flow cooling towers. Today’s cooling tower combine the latest advanced materials to achieve the optimum balancing of High corrosion resistance, product durability and cost. Based on their specific functions, cooling tower components are designed using the materials with the best combination of corrosion resistance and physical properties. In this work, the coefficient of performance is determined by using Simpson’s rule and the performance of cooling tower at various L/G ratios is evaluated. The optimum approach of the tower is calculated.


1983 ◽  
Vol 105 (3) ◽  
pp. 576-583 ◽  
Author(s):  
J. W. Sutherland

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.


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