Performance and sustainability assessment of green HFO-based refrigerant mixtures for residential air conditioning

This study explores environmentally friendly ternary mixture compositions based on Hydrofluoroolefins, which offer promising alternatives to R410a in air-conditioning applications. European union regulations require that household refrigeration systems utilize refrigerants with low global warming potential. In response to this mandate, the present study investigates the theoretical performance of 14 ternary mixtures. The analysis focuses on key performance parameters, such as coefficient of performance, exergy loss, refrigeration effect, exergetic efficiency, pressure ratio, and actual work input. The study is carried out at an evaporator temperature of 6°C and a condenser temperature of 40°C. The present study results confirmed that coefficient of performance decreases with higher concentrations of diluents like R227ea, R134a, and R125, indicating reduced performance. In contrast, R245fa improves coefficient of performance, enhancing system efficiency. R1234yf/RE170/R227ea mixture exhibited the most significant reduction in exergy losses, particularly within the compressor, condenser, and evaporator, achieving a total exergy loss reduction of 32% relative to R410a. R1234ze€/R161/R227ea mixture demonstrated consistent exergy loss reductions across all components, with a 25% drop at the expansion valve. Overall, it improved system exergetic efficiency by 17% compared to R410a. R1234yf/RE170/R227ea and R1234ze€/R161/R227ea mixtures are recognized as promising non-flammable alternatives for small air-conditioning systems, offering zero ozone depletion potential and low global warming potential.