论文部分内容阅读
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。
In this paper, a high-flux heat and mass transfer model of air gap membrane distillation system is established. The influence of steam condensation in the air gap and contact between the membrane surface and the cold wall on heat and mass transfer is considered. Before modeling, the convective heat transfer coefficient, the mass transfer correction factor and the air gap thickness correction coefficient on the membrane surface and the cold wall were determined experimentally and expressed as empirical formulas. The error of the membrane distillation flux and the experimental value predicted by this model on six membrane modules with different membrane thickness and different contact degrees between the membrane wall and the cold wall is generally less than 10%. The predicted degree of vapor condensation in the air gap is also in agreement with the experiment Observed consistent.