Abstract: Household refrigerator evaporators use different heat exchange pipe diameters, which will cause differences in the heat exchange performance of the heat exchanger and the performance of the entire refrigerator. The influence of heat exchange tube diameter and evaporator heat transfer performance of air-cooled refrigerator fin evaporator under different wind speeds and different mass flow rates is studied. The heat exchanger performance test bench is used to test the 5 mm/6.35 mm/8 mm tube diameter. The performance parameters of heat transfer coefficient, heat transfer, pressure drop loss and other performance parameters under different wind speeds are compared and analyzed. The results show that: when the system mass flow is 0.5 g/s and the wind speed is 1.6 m/s, the 6.35 mm pipe diameter evaporates. The heat exchanger has better heat exchange performance, which is 9.7% higher than the 5 mm pipe diameter and 7% higher than the 8 mm pipe diameter.

Key words: Heat transfer, Pipe diameter, Mass flow, Heat exchange, Pressure drop