Influence of noise barrier and louver on ventilation and thermal performance of wet cooling towers under crosswind conditions

Author(s):  
Lei Jiang ◽  
Zhengqing Zhang ◽  
Peng Sang ◽  
LinFeng Dong ◽  
Suoying He ◽  
...  
Author(s):  
Mostafa H. Sharqawy ◽  
John H. Lienhard ◽  
Syed M. Zubair

Seawater cooling towers have been used since the 1970’s 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 which govern the thermal performance of cooling towers, including vapor pressure, density, specific heat, viscosity, thermal conductivity and surface tension. In this paper, the thermal performance of seawater cooling towers is investigated using a detailed model of a counterflow wet cooling tower. The model takes into consideration the coupled heat and mass transfer processes and does not make any of the conventional Merkel approximations. In addition, the model incorporates the most up-to-date seawater properties in the literature. The model governing equations are solved numerically and its validity is checked by data in the literature. Based on the results of the model, a correction factor is obtained which characterizes the degradation of the cooling tower effectiveness when seawater is used.


2012 ◽  
Vol 232 ◽  
pp. 218-222
Author(s):  
Samad Ghafarigousheh ◽  
Ali Akbar Golneshan

In this paper a 3-D numerical model is used to investigate the thermal performance of a three aligned unit of NDDCT under crosswind condition. The computed results show that, there are major differences in computed velocity patterns and pressure fields around the cooling tower due to neighboring of a number of cooling towers will result considerable changes in computed flow parameters hence; the thermal performance losses for the single tower under crosswind are superior to those when this towers are incorporated in aligned arrangement. Results also show that the best thermal performance of the three aligned NDDCT is achieved when the crosswind is directed along the towers connection line.


Author(s):  
Mostafa H. Sharqawy ◽  
Iqbal S. Husain ◽  
Syed M. Zubair ◽  
John H. Lienhard

Seawater has been used for long time as a cooling fluid in heat exchangers to reduce fresh water usage in industry and power plants. The thermophysical properties of seawater are different from those of fresh water due to the salt content or salinity. This difference is sufficient to affect the heat and mass transfer processes which in turn change the thermal performance. Thermal design of fresh water cooling towers is described in detail in many textbooks and handbooks. However, only a rule of thumb is frequently used for designing of seawater cooling towers. This rule recommends degrading the tower performance by approximately 1% for every 10,000 ppm of salts in the feed water. In this paper, the thermal performance of seawater cooling towers is presented using a detailed model of counterflow wet cooling towers which takes into consideration the coupled simultaneous heat and mass transfer processes and uses state-of-the-art seawater properties from the literature. The model governing equations are solved numerically and the validity of this model is checked using new experimental data that has been measured using a bench top counterflow seawater cooling tower. The effect of the variation of seawater salinity as well as other operating conditions on the effectiveness and Merkel number is investigated.


2016 ◽  
Vol 18 (1) ◽  
pp. 111 ◽  
Author(s):  
Mohammad Ali Ardekani ◽  
Mohammad Ali Ranjbar ◽  
Foad Farhani

Author(s):  
Mostafa H. Sharqawy ◽  
John H. Lienhard ◽  
Syed M. Zubair

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 pressure, density, specific heat, viscosity, thermal conductivity, and surface tension. In this paper, the thermal performance of seawater cooling towers is investigated using a detailed model of a counterflow wet cooling tower. The model takes into consideration the coupled heat and mass transfer processes and does not make any of the conventional Merkel approximations. In addition, the model incorporates the most up-to-date seawater properties in the literature. The model governing equations are solved numerically, and its validity is checked against the available data in the literature. Based on the results of the model, a correction factor that characterizes the degradation of the cooling tower effectiveness as a function of seawater salinity and temperature approach is presented for performance evaluation purposes.


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