Performance of a new two-stage multi-intercooling transcritical CO2 ejector refrigeration cycle

In this study, a new two-stage multi-intercooling transcritical CO2 refrigeration cycle with ejector-expansion device (MIERC) is investigated. At this studied cycle, the vapor compression line includes two intercoolers, the first with external coolant (air or water) and the second one with cycle refrigerant. The overall performance of the new cycle was compared with that of the conventional ejector refrigeration cycle (CERC) and the internal heat exchanger ejector refrigeration cycle (IHEEC). It was found that the new cycle has the maximum amount of COP and IHEEC has the minimum one. The maximum COP value of the new cycle in the surveyed high-side pressure interval is 15.3% and 19.6% higher than those of CERC and IHEEC respectively. The effect of main cycle parameters such as compressor high-side pressure (discharge pressure), intermediate pressure, gas cooler outlet temperature and evaporator temperature on COP of cycle were studied and results presented here.