Characteristics of R718 refrigeration/heat pump systems with two-phase ejectors

The paper describes investigations of R718 refrigeration cycles with two-phase ejector as a compression device. The complex thermal and flow phenomena inside two-phase ejector flow field are analyzed and characteristics of two-phase ejectors are estimated. Results of investigations of numerous refrigeration systems with two-phase ejectors are analyzed and recommendations for optimal geometric parameters of two-phase ejectors are summarized. Novel R718 refrigeration/heat pump systems are proposed: simple two-phase ejector cooling cycle, two-phase ejector heat pump cycle applied in evaporators-concentrators, and combined compact R718 centrifugal compressor-two-phase ejector water chiller for air conditioning application, and their thermal and performance characteristics are estimated.