高通量空气隙膜蒸馏系统的传热传质模型

该文建立一个高通量的空气隙膜蒸馏系统的传热传质模型,考虑了空气隙内蒸汽冷凝及膜面与冷壁部分接触对传热传质的影响。建模前先由实验确定系统膜面及冷壁上的对流换热系数、膜内质量传递修正系数和空气隙厚度修正系数,并表达为经验公式。用该模型对6个膜面与冷壁有不同间隙厚度和不同接触程度的膜组件系统预测得到的膜蒸馏通量与实验值误差一般小于10%;预测的空气隙内蒸汽冷凝程度也与实验观察相符。

Heat and mass transfer model for a high-flux air gap membrane distillation system

A heat and mass transfer model was developed for a high-flux air gap membrane distillation system by analyzing the effects of the vapor condensation in the air gap and the partial contact between the membrane and the cooling plate on the heat and mass transfer.Experiments were used to establish empirical formulas for the convective heat transfer coefficients between the membrane and the cooling plate,correction coefficients for the mass transfer in the membrane,and correction coefficients for the air gap thicknesses.The differences between the predicted and measured permeation fluxes are less than 10% for six modules with various air gap thicknesses and contact areas between the membrane and the cooling plate,with predicted condensation levels in the air gap agreeing well with observations.