An Initial Analysis on the Energy-Efficient Performance of a Natural Draft Wet Cooling Tower with Cacl2 Solution for Power Plants

Applied Thermal Engineering 48 (2012) 249e255

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Applied Thermal Engineering

journal homepage: www.elsevier.com/locate/apthermeng

An initial analysis on the energy-efficient performance of a natural draft wet cooling tower with CaCl2 solution for power plants

Jiping Liu*, Yehui Jiang 1, Daotong Chong 2, Junjie Yan 3

State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, West Xi’anning Road, 28, Xi’an 710049, China

a r t i c l e i n f o

Article history: Received 5 October 2011 Accepted 31 January 2012 Available online 7 February 2012 Keywords: Cooling tower Water conservation CaCl2 solution

a b s t r a c t

To improve the performance of the natural draft wet cooling tower, the calcium chloride (CaCl2) solution is used as the circulating water to reduce its evaporation loss. Employing a natural draft wet cooling tower of 600 MW generating unit as a reference tower, a simplified mathematical model is utilized to determine its outlet water temperature and water consumption under different working conditions. The latent heat decreases and the sensible heat increases when the heat transfer takes place in the cooling tower and the concentration of CaCl2 rises in the solution, so the evaporation loss of the circulating water decreases. Water consumption decreases with the increase in salt concentration, whereas the cooling performance becomes bad. When the salt concentration is equal to 35%, the water consumption decreases about 28%, however, the outlet water temperature increases about 8  C. The performance and water consumption are studied under different working conditions of air parameters, water mass flow rates and tower parameters. The results indicate that the cooling performance and water-saving characteristics of the natural draft wet cooling tower can be improved comprehensively if the tower parameters are optimized. Ó 2012 Elsevier Ltd. All rights reserved.

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