Abstract: Capillary is applied as the throttling component in most dehumidifiers. When the dehumidifier leaks refrigerant, the dehumidifier is prone to frost which reduces the energy efficiency. Based on experiments to study the frosting situation and defrosting protection of the R32 refrigerant leakage process in the dehumidifier. The results indicate that The R32 refrigerant dehumidifier defrosting protection program will fail when overlooked the refrigerant leak conditions. When other conditions remain constant, the indoor dry bulb temperature is linearly negatively related to the frosting area and frosting time of the evaporator, and the refrigerant leakage rate of the dehumidifier is non-linearly related to the frosting time of the evaporator. The subsequent defrosting protection program can adjust the defrosting time and the fan's speed to decrease defrosting energy consumption base on the previous study. The inner distribution of the evaporator is affected significantly by the refrigerant leakage rate and indoor dry bulb temperature. The later defrosting protection program can set the defrosting protection enter temperature and the position of the temperature-sensing element to improve the accuracy of defrosting protection.

Key words: Dehumidifier, Refrigerant leak, Frosting, Defrosting protection, R32