Study on the performance of solar-assisted transcritical CO2 heat pump system with phase change energy storage suitable for rural houses

To alleviate the serious energy waste and air pollution caused by heating of buildings in rural areas, a solar-assisted transcritical CO2 heat pump system with phase change energy storage (STCHPS-PCES) suitable for rural houses is proposed. In addition to the environmental protection of refrigerants and the matching of heating characteristics with the building heat load, the system also achieves the complementary use and energy storage utilization of natural low-grade heat sources. Taking a 500 m2 residential building of a rural area in Shenyang, China as the case study building, the mathematical model of the system was established and its performance was simulated. The results showed that the system can meet the demand for building heating and hot water during the heating period. The seasonal coefficient of performance (COP) of the system is 2.56. Compared to the traditional decentralized coal-fired heating and hot water supply programmes in rural areas of Shenyang, the system's energy-saving rate is 43.55%.