Study on heating performance of solar assisted dual-source hybrid heat pump systems

The conventional air-source heat pump has some disadvantages such as low heating capacity and heating efficiency when outdoor air temperature is low in winter. A solar assisted dual source hybrid heat pump system(SSCHP) was proposed in this paper. A solar water source heat pump(WSHP)unit is coupled with an air-source heat pump (ASHP)unit to form the integral hybrid heat pump system. Hot water from solar collector is the heat source of WSHP unit. Using two compressors and one common condenser into the hybrid heat pump system makes it be possible for WSHP unit and ASHP unit to operate at the same time, or operate independently. To take a building in Zhengzhou for instance, the hourly heating load in one heating season(120 days)is evaluated by DeST software. Cycle performance and energy consumption were calculated and analyzed on a basis of the thermodynamic mathematical model of the hybrid heat pump system. The results show that COPh of the SSCHP increases obviously as compared to the conventional air-source heat pump. The daily energy conservation rate of the SSCHP changes in the range of 1.01% ~14.75%, and the energy consumption of the SSCHP in whole heating season decreases by 8.72%. The hybrid heat pump with dual compressors and two parallel evaporators has more potential of energy conservation than that one with one compressor and two serial evaporators. © 2019, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.