Power optimization for defrosting heaters in household refrigerators to reduce energy consumption

Abstract

Power optimization was conducted for the defrosting heaters (conductive and radiant heaters) in a freezer to enhance their performance. The distribution of frost in the evaporator was measured experimentally, and the required defrosting energy corresponding to frost accumulation was calculated. The influence of defrosting heaters on frost was evaluated by measuring the heat quantity of the evaporator. The optimization was carried out such that the two heaters distribute the valid energy to the evaporator minimizing the excessive waste heat. At the optimum heater power, the maximum surface temperature of the evaporator was reduced, and the temperature distribution of the evaporator became uniform. The heater power and defrosting time were reduced through power optimization, thereby increasing the defrosting efficiency up to 6.7%. The effective heater power distribution could be further promoted to other heat exchangers with various heat transfer technologies.