优化填料布置及配水对冷却塔性能的影响

Effect of fill layout and water flow rate distribution on the performance for cooling tower

为明确填料布置及配水对冷却塔冷却性能的影响,以浙江国华宁海电厂二期工程6#冷却塔为原型,建立三维数值模型,通过自定义函数加载质量、动量和能量计算程序,与实测对比,模拟结果准确.对比分析3种填料和5种填料布置对超大型冷却塔冷却性能的影响,发现与双向波和双斜波相比,S波冷却效率最优.与S波1.5 m填料等高布置相比,沿径向按无量纲半径rˇ≤0.39(内区)、0.39<rˇ≤0.70(中区)和0.70<rˇ≤1(外区)非等高1.25-1.5-1.25 m布置的出水温度降低了0.66 K,表明降低填料内区和外区高度,使得空气流速增加,空气流场分布更均匀.另外,当布水总量恒定时,增加冷却水含盐量,3种填料的出水温度均升高2 K左右,说明出水温度升高主要与海水自身性质有关,且受填料波型的影响较小.

In order to identify the effect of fill layout and water flow rate distribution on the cooling performance of cooling tower,a three-dimensional numerical model was established based on prototype of No. 6 Cooling Tower in the Second Phase of Guohua Ninghai Power Plant in Zhejiang Province. Loading the mass,momentum,energy equation was computed by using user defined function. The comparision with the field measurement data proves the accuracy of the numerical calculation result. The effects of three kinds of fills and five kinds of fills layouts on cooling performance of super-large cooling tower weve compared and analyzed. It is found that compared with biphasic wave and double oblique wave,the cooling efficiency of S wave is optimal. For S wave,based on the dimensionless radius rˇ ≤0. 39（ inner zone）,0. 39 rˇ ≤0. 70（ middle zone） and 0. 70 rˇ ≤1（ outer zone）,the outlet water temperature of non-uniform layout 1. 25-1. 5-1. 25 m is 0. 66 K lower than the outlet water temperature of the uniform fill layout pattern 1. 5 m. It is shown that the decreased fill height in inner and outer zones results in a higher air velocity and more uniform distribution of air velocity. In addition,increasing the salinity of cooling water made the outlet water temperature of three kinds of fills improve by about 2 K. It is indicated that the rise of outlet water temperature is related to the nature of seawater itself,and fill types has little impact on outlet water temperature.