The air forced convection is utilized to cool foods in frost-free refrigerator, and it offers uniform temperature field and the fast cooling rate. But the air forced convection also accelerates the water evaporation from foods surface, which leads to foods dehydration. Numerical model of water evaporation process inside refrigerating compartment was validated by experimental results including the evaporated water mass, air temperature and relative humidity during compressor on /off cycle. The air supply modes have effects on velocity and temperature fields inside refrigerating compartment, and three air supply modes were compared: annularly blowing air (ABA) supply, upward blowing air (UBA) supply and forward blowing air (FBA) supply modes. The results show that the water evaporation rate during compressor-on cycle is 20 times of that during compressor-off cycle. The effect of air velocity on water evaporation process is greater than that of vapor partial pressure difference. The water evaporation rate for FBA supply mode is the largest due to its highest air velocity. The water evaporation rate of ABA supply mode is the least because of both its smaller air velocity and vapor partial pressure difference, and it is the best mode to decrease water loss.

强制对流用于在无霜冰箱中冷却食物，并提供均匀的温度场和快速的冷却速度。但是空气对流还加速了食物表面水分的蒸发，从而导致食物脱水。通过实验结果验证了冷藏室内水蒸发过程的数值模型，包括压缩机开/关循环期间的蒸发水量，空气温度和相对湿度。供气方式会影响冷藏室内的速度和温度场，并比较了三种供气方式：环形吹气（ABA）供给，向上吹气（UBA）供给和正向吹气（FBA）供给方式。结果表明，压缩机开启循环期间的水蒸发速率是压缩机关闭循环期间的20倍。空气速度对水蒸发过程的影响大于蒸气分压差的影响。FBA供给模式的水蒸发速率由于其最高空气速度而最大。A的水蒸发率B由于空气流速和蒸气分压差都较小，因此供给模式是最少的，这是减少水分流失的最佳模式。