Experimental investigation on storage-type heat pump system for efficient supply in cold region

Abstract

Application of air source heat pump systems in cold region is severely limited by the low-temperature inadaptability. Utilizing latent heat storage to store condensation heat of heat pump during the day for nighttime heating maybe a potential solution. But continuous heat supply in both charging and discharging process hasn’t been completely achieved, which is also crucial for cold region. To fill this research gap, this paper proposes storage-type heat pump system using waste heat of subcooler for heat supply in the charging process. Besides, discontinuous heat storage and release are carried out to further verify the adaptability of the system. Experimental results demonstrate that heat from subcooler reaches 16.79 kW·h and the average heat release power of condensation thermal accumulator is 5.24 kW, and the output heat of subcooler can meet the daytime heating demand of a 100 m2 room. In this case, condensation heat utilization efficiency could reach 89.1 % and the average COP of system is 3.65. Also effective heating can be supplied within 48 h after heat storage. The results validate the feasibility of cogeneration of the subcooler and condensation thermal accumulator for continuous heat supply, which provides a guidance for its application at extremely low temperature.