湿式冷却塔节水消雾模块传热特性

Thermal performance of water saving and fog eliminating module for wet cooling tower

湿式冷却塔在温度较低的季节运行时,出口处形成了大量含微小液滴的白雾,造成了严重的循环水损失,影响周边环境。以此为背景,设计开发了一种新型节水消雾模块,根据Collburn-Hougen含不凝气冷凝换热模型,构建了求解该模块换热单元出口状态参数的热力计算模型。设计和搭建了增设节水消雾模块的湿式冷却塔热力性能实验测试平台,实验结果表明:当干冷空气的实验流速为3.5—7.5 m/s时,增大冷热流体进口温差,湿热和干冷侧进出口温差会增大;增大冷热空气流量比,湿热侧进出口温差会增大而干冷侧进出口温差先增大后减小;冷热空气进口温差和冷热流量比增大,冷凝收水率会增大。拟合得到湿热侧空气的复合传热关系式,与实验数据对比误差仅为8.79%,为消雾冷却塔工程化应用提供理论依据。

When the wet cooling tower runs in the low temperature season,a large number of white fog with small droplets is formed at the outlet,resulting in serious loss of circulating water.Based on this background,a new type of water-saving and fog-eliminating module was designed and developed.According to the Collburn-Hougen condensation heat transfer model with non-condensable gas,a thermodynamic calculation model for solving the outlet state parameters of the heat transfer unit of the module was constructed.The thermal performance test platform of wet cooling tower with water-saving and mist elimination module was designed and built.The experimental results show that when the flow of dry and cold air is 3.5-7.5 m/s,if the inlet temperature difference of cold and hot fluid increases,the inlet and outlet temperature difference of wet hot and dry cold sides will increase.If the cold and hot air flow ratio increases,the inlet and outlet temperature difference on the wet and hot side will increase,while the inlet and outlet temperature difference on the dry and cold side will increase firstly and then decrease.If the inlet temperature difference of cold and hot air and the ratio of cold and hot flow increase,the water saving rate will increase.The compound heat transfer equation of the air on the wet and hot side is fitted,and the error is only 8.79%compared with the experimental data.The equation provides a theoretical basis for the engineering application of demisting cooling tower.