Experimental Investigation of Heat Transfer Performance of a Finned-Tube Heat Exchanger under Frosting Conditions

Abstract

• Experiments were conducted with flat fin and corrugated fin heat exchangers. • The corrugated fins enter a high deterioration stage resulting from frost formation 50 minutes earlier than the flat fin. • The comprehensive performance evaluation factor of flat fin heat exchanger is 24.2% higher than that of the corrugated fin. The impact of factors influencing the performance of air source heat pumps (ASHPs) under frost conditions is complicated. Despite this, many preexisting studies focus only on the impact of individual factors on the heating performance of ASHPs. This study conducted an experiment to compare the performance of two commonly used evaporator fin structures, namely the corrugated fin and the plain fin, under different outdoor thermal parameters, including a temperature range of 0–6°C, 60%–90% humidity, and 1.5–4.5 m/s wind speed. The results show that the performance of the flat fin heat exchanger is better than the corrugated fin heat exchanger under frost conditions. The fin characteristics have a great influence on the frost of the heat pump outdoor unit. As the inlet airspeed increases, the effect of wind speed on the heat transfer performance of the heat exchanger gradually decreases. In the hot summer and cold winter zones in China, it was discovered that the performance of a flat fin heat exchanger, applied as a heat pump outside an evaporator, was better than that of a corrugated fin heat exchanger.