中文摘要：

对苹果强制通风预冷过程进行了试验研究。考察了湿冷空气风速、相对湿度和温度以及预冷筐空隙率对预冷时间的影响。结果表明，预冷的最佳操作风速为1．5m／s。采用低温高湿（温度4℃，相对湿度80％以上）气流对苹果进行预冷能取得良好的效果。当风速达到1.5m／s以上时，空隙率的改变对预冷时间影响不大；而风速小于0.75m／s时，空隙率增加会明显减少预冷时间。

英文摘要：

The forced-air precooling experiments of apples were carried out to study the influences of temperature, relative humidity and velocity of the cold air, and the void ratio of apples on the precooling process. The results show that the optimum operation velocity for the apples cooling is 1.5 m/s. Well cooling effect of apples can be obtained with low temperature （4℃, no chilling injury）and high humidity air （80% RH above） in air circulation. The void ratio of apples has little influence on the precooling time when the air velocity is greater than 1.5 m/s, and the increase of the void ratio will significantly reduce the precooling time when the air velocity is less than 0.75 m/s.