Abstract: Refrigerator doors may frequently suffer opening and closing process for the commonly used frost-free refrigerator. The uniformity of temperature in each compartment of refrigerator will be destroyed during the door opening and closing process, resulting in the damage of food storage quality. The purpose of this study is to develop a simulation method for the door opening and closing process of a frost-free refrigerator, and to analyze the temperature variation in each compartment of a typical frost-free refrigerator under the condition of door opening and closing. In the method of CFD dynamic grid, a whole door opening and closing process is divided into three sub-process, including the sub-process of door opening, the sub-process of door opening maintaining, and the sub-process of door closing. The total thermal loss is calculated through monitoring the average temperature of refrigerator and the average mass flow rate of outlet air for each discrete time point. The thermal loss of the refrigeration compartment, the variable temperature compartment and the freezer compartment under the same door opening and closing conditions is calculated, and the results show that the large increase rate of temperature in each compartment occurs in the door opening process, and low increase rate of temperature of temperature in each compartment occurs in the door closing process. The thermal loss in the freezer compartment is larger than that in the variable temperature compartment or in the refrigeration compartment, meaning that the temperature non-uniformity in the freezer compartment is the worst.

Key words: Refrigerator, Door opening and closing, Temperature field, Simulation method