High temperature heat pump has great development potential for industrial heat because it is energy-saving and environmentally friendly. This paper focuses on the optimization analysis and experimental investigation of an air source cascade heat pump (ASCHP) to realize 130℃ heat supply under the ambient temperature of 20℃, with refrigerant R245fa and R410A in the two stages respectively. The high stage is designed with vapor injection (VI). The optimal configuration of the intermediate temperature and VI branch temperature is obtained by optimization analysis. An ASCHP unit is developed and the experimental results match the optimized results well. The coefficient of the VI model is deduced according to the experimental result. The coefficient of performance (COP) of the developed heat pump unit is 1.39.
Keywords air source cascade heat pump, vapor injection, optimization analysis