Thermal analysis of heat pump systems using photovoltaic-thermal collectors: a review

In this article, the thermal analyses of heat pump systems using photovoltaic-thermal collectors are reviewed. Initially, the energy balance equations used for modelling the photovoltaic-thermal collectors are described. Further, the equations used for evaluating the thermodynamic performance of heat pump systems are listed. Then, the reviews of reported investigations on thermal analysis of heat pumps using photovoltaic-thermal collectors are presented. The studies reported in the open literature are grouped into six major sections such as photovoltaic-thermal air collectors, photovoltaic-thermal liquid collectors, direct expansion photovoltaic-thermal collectors, photovoltaic-thermal collectors as condensers, control of heat pumps using renewable energy and future environmentally friendly refrigerant options. The performances of the various photovoltaic-thermal collector configurations are described. The major limitations associated with existing configurations are identified, and further research scopes in this field are listed. Finally, this paper concludes that the heat pump systems using photovoltaic-thermal collectors are having good potential for drying, water heating and space heating applications. The information presented in this paper is more beneficial to the researchers working on heat pump systems using photovoltaic-thermal collectors.