蒸发式冷凝器凹凸型板片间传热特性试验与理论分析

Experiment and Theoretical Analysis of Heat Transfer Characteristics in Bump Plate of Evaporative Condenser

对采用凹凸型板片的蒸发式冷凝器的传热与流阻特性进行了试验分析,在此基础上建立了三维模型,对其板片间的气-液两相流进行了模拟,分析了喷淋水量、入口空气流速、板片间距和湿空气状态对换热性能的影响,并将模拟结果与实验对比验证。结果表明:表面传热系数随喷淋密度增大而增大,喷淋密度大于0.12kg/(m^2·s)后,板片表面间传热系数增长变缓;板片表面传热系数随入口空气流速的增大和板片间距的减小而逐渐增大;湿空气含湿量越低,换热性能越好,干球温度对换热性能影响不显著。

The heat transfer and flow resistance characteristics of evaporative condenser with bump plate were experimented and analyzed. Three-dimensional model was established and gas-liquid two-phase flow in the plate bundles was simulated based on the experiment to analyze the effect of water spray density, air flow rate, plate space and state of moist air on the plate heat transfer performance. The result of the simulation was compared with the experiment. Results show that： Surface heat transfer coefficient increased with the increase of spray density, but the increase became smaller when spray density was to 0.12kg/（m2·s）. Surface heat transfer coefficient increased with the increase of air flow rate and the decrease of the plate space. The lower the humidity ratio is, the better the plate heat transfer performance is. The influence of dry bulb temperature on heat transfer performance was not significant.