Performance Evaluation of Low-GWP HFO Refrigerants and Their Blends in a Subcooled Vapor Compression Cycle: A Python-CoolProp Simulation Approach

The environmental challenges posed by high-GWP refrigerants like R134a have necessitated the transition toward lowGWP alternatives, notably Hydrofluoroolefins (HFOs). This research presents a detailed simulation-based performance analysis of a Vapour Compression Refrigeration System (VCRS) incorporating a Liquid–Vapour Heat Exchanger (LVHE) to enable mechanical subcooling. Using Python and CoolProp, we compare the thermodynamic behavior of R134a, pure HFOs— R1234ze(E) and R1233zd(E)—and their binary blends across varying subcooling levels (0°C–30°C). An optimal subcooling value of 20°C is established, and a 70:30 blend of R1234ze(E) and R1233zd(E) is proposed as the most viable drop-in alternative to R134a. The results demonstrate substantial improvements in Refrigeration Effect (RE), Coefficient of Performance (COP), and system safety under optimized subcooling. Validation against published benchmarks ensures the reliability of the simulation approach. This study contributes a novel, environmentally conscious refrigerant blend optimized for subcooled VCRS applications, aligning with international climate mandates.