Research On The Defrosting Of Heat Exchanger With Heat Insulation

This research includes the design and construction of the device of heat insulation and defrosting,the simulation of the temperature field of the heat insulation refrigeration storage,and the study of the comparative experiment about temperature distribution of the refrigeration storage between the heat insulation defrosting process and the conventional defrosting process.First,a heat insulation defrosting device is designed,and physical and mathematical models are built.The inside temperature distribution is simulated using the finite element analysis software ANSYS FLUENT,and the major content of this research are: design and construction of heat insulation hot fluorine defrosting device;the multiple conditions of defrosting control so that times of defrosting process reaches the stability initial conditions;the relationship between the frost-layer thickness and the cooling wind speed and the time of the defrosting;the comparison between the time of the heat insulation defrosting and conventional defrosting,the characteristics of temperature cooling after defrosting and its influence to the cold storage’s temperature field.The following conclusions can be made from the simulation and experimental study:Compared to the conventional defrosting mode,the heat insulation defrosting mode defrosts faster,has a smaller influence on internal temperature,the cold storage’s refrigeration condition can be quickly restored.The conventional hot fluorine defrosting mode will turn on the fan and get into the refrigeration state after the frost layer is gone,while high-temperature hot air will be briefly sent out of the air cooler,which lasts over ten seconds,and that time varies with the working conditions.This is a harmful process to the refrigeration process.In the case of the frost layer’s thickness of 3.4mm,the heat insulation defrosting mode is five minutes faster than the conventional defrosting mode.Compared to the conventional defrosting mode,the heat insulation defrosting mode defrosts faster,has a smaller influence on internal temperature,the cold storage’s refrigeration condition can be quickly restored,and energy is saved..