Energy and exergy analysis of a novel solar-air composite source multi-functional heat pump

As multi-functional heat pump with higher equipment utilization rate will face more complicated operation condition, the integration with composite heat source will be good solution to improve the operational stability and output performance. In this paper, a novel solar-air composite source multi-functional heat pump (SA-CMHP) has been proposed. Different from conventional single-source heat pump, the proposed system has two evaporators operating in parallel in space heating mode. As the distribution of refrigerant at evaporation side is associated with the output performance of SA-CMHP, the space heating performance under different refrigerant distribution ratio (γ) has been studied based on energy and exergy methods. Besides, economic performance of SA-CMHP for space heating has been analyzed and compared with single-source heat pump. The results indicate that with the increase of γ, the variation of evaporation capacity, power consumption, heating capacity, COP and exergy efficiency tends to increase at first and then decrease. When solar irradiation is 200W/m2, 300W/m2 and 400W/m2, COP and exergy efficiency reach the highest value at γ of 0.6, 0.7 and 0.8. When ambient temperature is 4 °C, 7 °C and 10 °C, COP and exergy efficiency reach the peak values at γ of 0.6.