Mass-flowrate-maximization thermodynamic model and simulation of supersonic real-gas ejectors used in refrigeration systems

•A new thermodynamic model for ejectors based on mass flow maximization is presented.•Complex descriptions of the double-choking mechanism at play are avoided.•Model validated with R600a and R134a experimental results.•Comparative analysis on the use of different fluids is performed for a SERS cycle.•Role of the superheating and limitations for two-phase conditions are highlighted.