Frosting Performance Dynamic Simulation and Analysis of Freeze Dryer Vapor Captor

LG type vacuum freeze dryer vapor captor is taken as the study object, and a mathematical model of frost heat transfer of the vapor captor was established, the effective heat capacity method was used to simulate the heat transfer processes of vapor captor. Frosting mechanism under low temperature and low pressure condition was investigated, and the changing relation curves of temperature distribution, thickness and density of frost layer on vapor captor coil along with time were obtained. The results show that with the increasing of the frost thickness, the surface temperature of frost layer increase, and the heat transfer coefficient continue to fall, the rate of increase in frost thickness of late stage is faster than the early by 30.3%.