湿工况下翅片管换热器空气侧热质传递的数值模型

析湿在翅片管换热器用作蒸发器时经常发生，对换热器的性能有重要影响.文中提出了能从机理上对湿工况下翅片管式换热器空气侧的热质传递过程进行模拟的数值模型，它不仅包括用于反映水蒸气和液态水之间由于浓度差所形成的传质模型，而且包括基于经典成核理论的反映水蒸气直接冷凝过程的传质模型.该模型的计算精度较好，传热无量纲参数jh和实验数据的平均相对误差为6.93%，传质无量纲参数jm和实验数据的平均相对误差为12.1%.数值仿真表明，空气相对湿度仅在部分析湿工况下对传质特性有较大影响.

Numerical Model of Heat and Mass Transfer for Tube-Finned Heat Exchangers under Dehumidifying Conditions

Dehumidifying process is very common in the evaporating conditions of finned tube heat exchangers, which has tremendous effect on the performance of heat exchangers. In order to make the simulation closer to the heat and mass transfer mechanisms, a numerical model of heat and mass transfer on air side was established. Not only is the mass transfer produced by the concentration difference between water vapor and liquid 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. The numerical simulation shows that the relative humidity only affects the mass transfer characteristics under partial wet conditions.