The optimal design and energy consumption analysis of forced air pre-cooling packaging system

摘要

The packaging system has a significant impact on forced air pre-cooling of the fruits and vegetables. In this work, the simulation model of forced air pre-cooling of products in different opening ratio packaging system was established by using computational fluid dynamics method. The cooling time, inhomogeneity and energy consumption were analyzed in different packaging system when the air velocity (volume flow per unit mass) was constant. The simulation and the experiment results agreed well in different conditions. The results showed that when the air velocity (volume flow per unit mass) was constant, the opening ratio of the packaging system had less influence on the 7/8 pre-cooling time (no more than 20%). With the increased of opening ratio for packaging system, the pre-cooling energy consumption and the cooling inhomogeneity were all decreased. Finally, a new expression for energy consumption in terms of opening ratio and air velocity was established and the expression was modified according to different fruits diameters.