Experimental investigation on efficient heating method of solar composite heat pump based on evaporative thermal accumulator.

Utilisation of combined solar energy and heat pump systems for heating has the potential to result in a notable reduction of carbon emissions. Nevertheless, the intermittent nature of solar energy and the low-temperature limitations of heat pumps still pose challenges. In order to address this issue, this paper combined the two aforementioned technologies and integrated direct phase-change thermal storage. A solar composite heat pump system with an evaporative thermal accumulator is put forth, with the objective of enhancing heating efficiency. An experimental setup was employed to examine the dynamic performance of the evaporative thermal accumulator under diverse solar thermal-electric conditions and evaluate the influence of two heat transfer media. The experimental results demonstrated that utilisation of phase change slurry as the heat transfer medium led to an enhancement in the power generation efficiency of the PV/T system, with an increase of 2.71 % compared to water-based systems. and also proved to be effective in enhancing the stability of the PV/T system. Additionally, the heat pump and composite system achieved average COPs of 4.74 and 8.23, respectively, representing a substantial 57.36 % increase compared to water-based systems. These findings demonstrate the feasibility and promising potential of using phase change slurry in solar composite heat pump systems. • A novel solar composite heat pump with evaporative thermal accumulator is proposed. • Phase change slurry increases PV/T system efficiency by 2.71 % over water-based systems. • Heat pump and composite system achieve COPs of 4.74 and 8.23, a 57.36 % improvement. • Demonstrate the feasibility and promising potential of using phase change slurry in this system. [ABSTRACT FROM AUTHOR]