中文摘要：

本文对热风干燥过程固体壁面上水膜蒸发过程进行了研究,视干燥过程为传热传质耦合传递过程。结合分离变量法得到了特定边界条件下水膜内部的温度分布解析解,并以此研究了水膜厚度、水膜表面对流换热系数等因素对水膜蒸发特性的影响。结果表明水膜越厚,水膜内温度分布非线性越显著,水膜表面达到湿球温度所需时间越长。随着蒸发过程的进行,水膜内导热热流逐渐减小,水膜表面蒸发潜热逐渐增加,最终完全等于对流换热热流。

英文摘要：

This work sccks to investigate the transient water film evaporation characteristics on solid wall during hot-wind drying procedure,which is considered as a coupled heat and mass transfer process.An analytical solution for temperature distribution in water film with a combined sensible and latent heat transfer boundary at water/air interface is derived based on the method of variable separation.The water film evaporation characteristics are analyzed for different initial water film thicknesses,convective heat transfer coefficients based on the analytical solution.The results show that as water film thickness increases,the non-linearity of temperature distribution becomes more obvious and the time needed for film surface temperature to reach the air wet-bulb temperature increases.As water film evaporates,the latent heat needed for water evaporation comes mainly from the water film by heat conduction at the initial stage,but more from the air fluid by heat convection afterward,and entirely from the air fluid when the water temperature attains to the air wet-bulb temperature.