从非平衡热力学理论和相平衡原理出发 ,对多孔介质对流干燥过程中水分蒸发、扩散过程的物理机制进行了分析 ,结果表明 :干燥操作的热力学条件是干燥介质处于未饱和状态 ,干燥时驱动水分蒸发、扩散过程的驱动势是广义热力学力 ,且物料温度愈低、干燥介质温度愈高、相对湿度愈小 ,则驱动势愈大 Based on the theory of non-equilibrium thermodynamics and the principle of phase equilibrium, the physical mechanism of water evaporation and diffusion during convective drying of porous media is analyzed. The results show that the thermodynamic conditions of drying operation are that the drying medium is in an unsaturated state, and the moisture Evaporation, the driving force diffusion process is a generalized thermodynamic force, and the material temperature is lower, the higher the temperature of the drying medium, the smaller the relative humidity, the greater the driving potential