Defrosting performance of multi-split air source heat pump using different phase change material-heat exchanger

To improve the defrosting performance of multi-split air source heat pump, phase change material was used to provide sufficient defrosting energy. Two different phase change material-heat exchanger(PCM-HE), fin-tube type and spiral coil type, were respectively designed and added in the multi- split air source heat pump to improve defrosting performances. The defrosting performances using these two PCM-HEs were measured in the simulated indoor and outdoor environments. The experimental results indicated that the defrosting duration were respectively reduced by 1/3 and more than 1/2 when using the spiral coil type and fin-tube type PCM-HE. Furthermore, suction pressure and temperature could be effectively increased when using fin-tube type PCM-HE, and thus defrosting duration and energy were also decreased.