金属平片冷表面湿空气凝水过程热质传递特性的数值模型

Numerical Model of Heat and Mass Transfer During Moist Air Condensing on Cold Plane Metal Plate

湿空气经过换热器翅片冷表面,会发生凝水现象,从而对换热器的热质传递特性有重要影响。本文提出了换热器平翅片冷表面湿空气凝水过程热质传递特性的数值模型,该模型中反映了水蒸气和液态水之间由于浓度差所产生的传质过程、水蒸气直接冷凝所产生的传质过程,以及凝水过程的潜热能量传递。模型计算精度较好,传热无量纲参数jh预测值和实验数据的平均相对误差为6.93%,传质无量纲参数jm预测值和实验数据的平均相对误差为12.1%。

There is water condensation when moist air flows through the fin surface,which may affect the heat and mass transfer characteristics of the heat exchangers.A numerical model of heat and mass transfer during moist air condensing process on cold plane fin surface is established in this paper.Not only the mass transfer produced by the concentration difference between water vapor and liquid is considered in this model,but also the simulation of direct water vapor condensation is added by means of classical nucleation theory.The comparison between the numerical model and experimental data shows that the numerical model has good accuracy.The relative errors for jh factor and jm factor are 6.93% and 12.1%,respectively.