Performance of a Ground-Water Assistant Air-source Compound Heat Pump in Refrigerating Conditions

Air-source heat pump uses air as heat source. The system is simple and needs low initial investment. But the performance of air-source heat pump significantly changes when the outdoor air temperature changes, especially in the hottest summer and coldest winter day. The cooling or heating capacity and efficiency will significantly decline. In order to improve the air-source heat pump efficiency and thermal capacity in the hottest summer and coldest winter day, this paper introduces a ground water assistant air source compound heat pump (GWA-ASCHP), and the cooling and heating performance in rated and peak load conditions were tested. The results show that the performances of GWA-ASCHP were improved observably by the assistant ground water. When the water flow is 50% of the ground water source heat pump system, the EER of the GWA-ASCHP is nearly 30% more than the air-source heat pump in rated condition and the EER can raise nearly 65% in peak cooling condition, and the COP of the GWA-ASCHP is about 20% more than the air-source heat pump in rated condition and the COP can raise more than 40% in peak heating condition