Nader Alihosseini - M.Sc, Department of Mechanical Engineering, Central Tehran Branch, Islamic Azad University, Tehran,Iran,R&D Department, Himalia Home Appliances Company, Alborz, Iran
Gholamreza Salehi - Assistant Professor, Department of Mechanical Engineering, Central Tehran Branch, Islamic Azad University, Tehran,Iran,

In this article, we optimize the energy consumption in the defrost cycle of a domestic refrigerator-freezer. In this refrigerator-freezer, the parallel two-stage compression (PTC) cycle is used. These systems have an automatic defrost mode and are designed so that the thaw from moisture on the evaporators is melted by the electronic board command . The heating elements are ۲۲۰ V and their use for defrosting consumes ۱۴۵ W of power, which causes a lot of heat and power consumption and increases energy consumption. In this study, in a domestic compression refrigerator-freezer, we use a Brushless direct current (BLDC) fan to defrost the fresh food compartment evaporator (FFCE) when the compressor shuts down, which is automatically set at a preset time and frequency. In this type of domestic refrigerator-freezer, due to the low temperature in the evaporator of the FFCE and its small volume, the heating element can be removed to defrost in the FFCE. Defrosting in the FFCE section will be done by the evaporator fan. The equipment used in the refrigerator-freezer cycle includes variable speed compressor, condenser, dryer, three-way valve, FFCE, and Freezer compartment evaporator (FZCE). R-۶۰۰a refrigerant is used in the refrigerator-freezer cycle. The refrigerator-freezer is tested in a laboratory refrigerator-freezer with an ambient temperature of ۲۵ °C, in accordance with international standards (IEC ۶۲۵۵۲). The energy consumption of this refrigerator-freezer according to the relevant standard is equal to ۳۲۰ kWh/ year, which has an A + + energy consumption grade.

Domestic refrigerator-freezer, Defrost, Evaporator fan, Energy consumption.