Performance and economic evaluation of a solar-air hybrid source energy heating system installed in cold region of China

This paper proposes a solar-air source energy storage heating system (SASES-HS), which can solve the problems of high energy consumption and difficult defrosting when the ambient temperature is low. By coupling solar energy,air energy and phase change energy, the system heats the end of the user through a two-stage heat pump. In order to analyze the feasibility of the system, the mathematical model of the system is established, and an experimental platform is built. A typical experimental condition was chosen to analyze the performance of the system in detail. The results show that the system can continuously provide high-temperature hot water of nearly 60 degrees C for buildings in a severe cold environment of -20 degrees C for 24 h, and the heat exchange temperature difference is as high as 80 degrees C. In addition, the system operates with a higher coefficient of performance than a single-stage heat pump system. The COP can reach the level of 4.1 during the day and as low as 2.5 at night. The operating cost of the system only accounts for 65.8% and 88.4% of the coal-fired boiler and the air source phase change heat pump, respectively. And the CO2 emissions of this system only account for 57.5% and 88.4% of the coal-fired boiler and the air source phase change heat pump, respectively. In view of the analysis of operational performance and economic and environmental benefits, it is found that the system is worth popularizing and using in the northern cold regions.