The experimental analysis of ejector‐based R290 heat pump system for domestic applications

The preliminary experimental study of a novel ejector‐based air‐source R290 heat pump was performed. The two‐phase bypass ejector was installed in a R290 heat pump unit and a number of modifications were introduced to the baseline system. The adaptions included implementation of the internal heat exchanger, increasing the superheat at the compressor suction port, and a liquid separator for handling the two‐phase flow at the ejector outlet. The performance evaluation of the system was based on COP and system heating capacity. Additionally, the comparative analysis with the R290 heat pump utilizing standard expansion valve for five typical operating points was carried out. The system working with an ejector as a throttling device allowed for up to 30% of COP improvement over the system utilizing an expansion valve. Additionally, the ejector implementation resulted in decreased pressure ratio of the compressor, which increased the system heating capacity by up to 12%.