湿式冷却塔热力性能数值分析

Numerical study of thermal performance on wet cooling tower

对气流运动采用标准k-ε湍流模型,喷淋区和雨区采用离散相模型计算,对填料区建立了基于Poppe理论的数值求解模型。基于该模型,在不考虑自然风情况下,对某300 MW机组自然通风湿冷塔的热质交换进行数值模拟,分析了淋水密度、进塔水温、喷嘴数和水滴直径对冷却塔热力特性的影响。计算结果表明:基于CFD软件的冷却塔数值求解模型有很好的适用性,淋水密度和水滴直径对出塔水温影响很大,为进一步完善冷却塔的设计与运行提供了理论依据。

Heat and mass transfer inside a natural draft wet cooling tower （NDWCT） of a 300 MW unit were investigated numerically under no natural wind condition. The CFD model utilized standard κ -ε turbulence model as the turbulence closure. The current simulation adopted discrete phase model in the spray and rain zone, and used userdefined model to represent the heat and mass transfer which was based on the Poppe theory in fill. Effects of the fol- lowing operating parameters on the thermal performance of the NDWCT were investigated： water flow rate, inlet water temperature, number of nozzles and droplet diameter. As a result, the effects of water flow rate and droplet diameter on： the thermal performance are found to be significant.