Performance of a novel dual-heat-source heat pump system

Abstract

A novel photovoltaic-thermal and air dual-heat-source evaporator was designed in this study. The evaporator was constructed using the micro heat pipe array instead of the aluminum absorbing plate to optimize the structure. Two fans were installed on the evaporator to forced convection heat transfer on the air side. Then a novel dual-heat-source heat pump system was developed, and the system was evaluated under various conditions. The results showed that the system exhibited excellent performance when operated under solar energy source or solar energy and air dual-heat-source modes. The coefficient of performance increased by 23.6%-31.4% compared with the air source mode. The function of the surrounding air under the solar energy and air dual-heat-source mode varied between exothermic and endothermic effect. The amount of heat absorbed from the surrounding air under the solar energy and air dual-heat-source mode gradually decreased with an increase in the system operation time. The electrical, thermal and overall efficiencies as well as coefficient of performance of the system significantly fluctuated with varying solar radiation and the surrounding air temperature. The findings provide a basis for further optimization of the system.