A comprehensive review of the hybrid heating systems consisting of heat pumps and solar collectors for hot water and space heating application

Abstract

A solar-assisted heat pump system is a hybrid system that integrates a solar collector and a heat pump, serving diverse functions such as space conditioning, drying, and generating heated water. The system's classification is based on the connection configuration of the solar collector and heat pump, which may involve a serial, parallel, or dual arrangement. Solar-assisted heat pump systems enhance output efficiency by harnessing solar energy in various heating modes, with the effectiveness contingent on the prevailing environmental conditions. As stated above, these systems are essential in lowering power consumption and reducing emissions. This study comprehensively assesses the research and development of solar-assisted heat pumps for building applications. This study delves into the classification of these systems, including direct expansion and indirect expansion solar-assisted heat pumps. Each configuration is to be detailed, and their thermal performance and demonstration samples are thoroughly examined. Furthermore, the study includes the assessment of energetic indicators for individual components and the overall system. Additionally, an investigation has been conducted on various refrigerant types that show promising potential for use in solar-assisted heat pump systems. It shows that adding an air evaporator to direct expansion solar-assisted heat pump solves the systems' deterioration during the absence of solar energy. The effect of climate on the indirect solar-assisted heat pump can be solved by designing the system to work in parallel or series configuration, depending on the solar energy availability.

Keywords

• solar energy
• heat pump
• heating application
• trnsys simulation
• systems configuration