板式蒸发式冷凝器传热传质的数值模拟

基于VOF算法，建立了板式蒸发式冷凝器气-液两相降膜流动传热传质的计算模型，该模型考虑了表面张力动量源项和气-液相间传热传质源项．并利用该模型，定量分析了不同壁面热流密度、液相进口温度和空气速度下竖直板面的温度分布、气-液界面处潜热和显热换热量的相对关系．计算结果显示，液膜和空气内温度随壁面热流密度的增大而增大，在气液界面处，温度梯度存在不连续；气-液相界面处的换热主要形式为水蒸发传质引起的潜热换热为主、空气显热传热为辅，并且传热热阻主要集中于水膜内；并且随风速的增加，相间传质量也随之增大．

Numerical Simulation on Heat and Mass Transfer in Two-phase Flow of Plate Evaporative Condenser

A computational model using the volume of fluid (VOF) method was established for predicting the heat and mass transfer process of two-phase falling film in plate evaporative condenser, in which the surface tension momentum source term, heat and mass transfer source terms were included. This model was used to analysis the temperature profiles and the relative relationship of latent heat transfer and mass transfer. It is found that the main manner of heat transfer in the interface of liquid-gas, the latent heat transfer caused by evaporation is much greater than the sensible heat transfer caused by the temperature gradient. And the results also indicated that the mass transfer increased with the increase of air velocity.