【摘要】 利用CFD软件对逆流降膜蒸发过程进行了实验模拟研究,研究了速度边界层、热边界层和浓度边界层的变化对降膜蒸发传热传质特性的影响规律;通过建立一维逆流降膜蒸发的数学方程编程求解出了对流传热传质的Nu数和Sh数,利用Fluent软件模拟出的实验结果采用回归分析得出了气液流量比Raw、流道的长宽比αL、空气进口无量纲温度θai以及空气进口Re数与Nu数、Sh数之间的无量纲关系式,可为降膜蒸发换热器的设计提供参考。更多还原

【Abstract】 A numerical study is conducted for the counter-flow falling film evaporation by using a CFD software,the influences of the length of velocity entrance region 、thermal entrance region and concentration entrance region on the falling film evaporating transfer characteristics are discussed;one-dimensional model is employed for solution of the Nusselt number and Sherwood number for heat and mass transfer,Through the regressive analysis of the numerical experimental data,the relationships of flow ratio of the gas-liquid 、 length to width ratio of the channel 、dimensionless temperature and the Reynolds number of the inlet air of Nusselt number and Sherwood number are given,the research has reference effect for the design of falling film evaporation heat exchanger.更多还原