Thermodynamic evaluation of CO2 transcritical refrigeration cycle with ejector

In the present work, an attempt has been made to analyse the use of an ejector as an expansion device. A review of refrigeration cycles with ejector was done. The effect of the introduction of the internal heat exchanger in the single-stage and the two-stage CO2 refrigeration cycles with ejector was analysed. It is concluded that whatever the value of the thermal efficiency of the internal heat exchanger, there is an optimum pressure for which the coefficient of performance (COP) reaches its maximum value and the variation of the heat exchanger thermal efficiency does not affect the optimal pressure, but it is noted that the introduction of the internal heat exchanger negatively affects the maximum performance of single-stage cycle and positively affects the maximum performance of the two-stage cycle. New cycles were proposed and their performance was discussed and compared with the existing cycles in the literature.