Development of a New-Type Multiple-Source Heat Pump with Two-Stage Compression

A new-type multiple-source heat pump cycle with two-stage compression was established on the basis of the problems of similarly existing heat pumps. The equivalent temperature levels of typical evaporators are applied to the different heat sources of the proposed cycle, and the high-temperature heat sources are shown to enhance vapor injection. Then, the mathematical model and prototype are developed, and the results from experimental simulation and validation showed that the solar collector can improve the heating performance of the proposed heat pump system. In the middle-temperature heating period, the outdoor temperature is less than −25°C, and the average coefficient of performance (COP) value of the proposed heat pump was 4.2, which was greater than the COPs of conventional ground source heat pumps.