Experimental investigation on direct expansion solar-air source heat pump for water heating application

Abstract

Solar water heating has turned out to be a common technique adopted for achieving the development of a sustainable and renewable energy goal. However, the intermittent nature of solar energy confines water heating during nighttime and dusky hours. Thus Direct Expansion Solar-Air Source Heat Pump (SAHP-DX) is used for extracting both the solar energy and ambient thermal energy source in an effective method. In this experimental work, a dual-source heat pump is designed to operate throughout the day for water heating applications in a sustainable manner. Performance of SAHP-DX water heating system in Solar Air Source Mode (SAHP-DX-SAM) and Air Source Mode (SAHP-DX-AM) are experimentally investigated and compared. Energy and exergy performance characteristics are evaluated and compared during summer and winter days. The average coefficient of performance (COP) of SAHP-DX-SAM is comparatively higher than SAHP-DX-AM by 17.6%. Cycle average power consumption and heating time of SAHP-DX-SAM is reasonably lower than SAHP-DX-AM by 16.9% and 23.6%. Exergy destruction from SAHP-DX-SAM is considerably lower than SAHP-DX-AM by 3.4%. Hence the current research shows the recommendation and implementation of SAHP-DX for water heating applications in hot regions for effective and rapid heating.