Advancing sustainable refrigeration: Ejector expansion refrigeration cycles for energy efficiency and environmental protection

• Ejector expansion cycles enhance energy efficiency by reducing expansion losses. • Condensation rise (30–65 °C) cuts suction nozzle exit diameter by 7.6 %. • Motive nozzle exit grows by 11.2 % as condensation temperature increases. • Optimal entrainment ratio is 0.8; max efficiency is 0.55 at a 7.5 area ratio. • Ejector efficiency enhances coefficient of performance. Due to their high global warming potential (GWP) refrigerants, conventional vapor compression refrigeration systems (VCRS) have throttling losses, decreased energy efficiency, and environmental issues. By reducing expansion losses and improving system performance, ejector expansion refrigeration cycles (EERC) provide a sustainable substitute. In order to increase energy efficiency and lessen environmental effect, this work attempts to parametrically examine EERC setups. In contrast to previous studies, this work does a thorough numerical analysis of EERC utilizing a variety of refrigerants, emphasizing the impact of area ratio, ejector efficiency, ambient temperature, and ejector entrainment ratio on system performance. In EERC configurations using constant area mixing (CAM) and constant pressure mixing (CPM) ejector models, the study compares the coefficient of performance (COP) and energy consumption across twelve refrigerants using MATLAB for thermal performance simulations and REFPROP for fluid properties. The EERC CAM setup shows a 7.5 % higher COP than EERC CPM and a 20 % improvement over VCRS. R152a and R410A are the best performing refrigerants among those examined. In particular, R152a attains a COP that is roughly 12.2 % greater than R134a and 8.5 % higher than R410A. Maximizing COP requires optimal ejector design, especially in the motive portion. These results highlight EERC's potential for creating green cooling systems that improve energy efficiency and lessen their negative effects on the environment.