Thermodynamics studies on VCRS using refrigerant blends of R290, R600A, and R1234ZE

The thermodynamic properties of three refrigerant combinations (R134a + R290, R134a + R600a, and R1234ze (E) + R600a) were analyzed using the “PR-MC-WS-NRTL” model. This model uses the NRTL (non-random two-liquid) model to integrate the Peng–Robinson equation of state, Mathias–Copeman alpha function, and the Wong–Sandler mixing rules. The thermodynamic model was employed to characterize the vapor–liquid equilibria properties of refrigerant mixes. The model predictions and experimental findings exhibited a high level of concordance, with a relative difference of 1.17% for the liquid mole percent. In addition, the model’s capacity to accurately represent the behavior of the blends was further confirmed by the fact that the relative change of the vapor mole percentage was just 0.74%. These results provide evidence that the PR-MC-WS-NRTL thermodynamic model adequately characterizes the thermodynamic parameters of the refrigerant mixtures that were evaluated. Natural refrigerants offer a sustainable alternative with reduced environmental impact, and this approach can be valuable in the design and optimization of air conditioning and refrigeration systems that utilize these refrigerants. The subsequent section of this research investigates the efficacy of these binary refrigerant systems as a substitute for R134a in a basic vapor compression refrigeration system (VCRS) cycle. The temperatures at which evaporation occurred ranged from – 10 to 10 °C, but the temperature at which condensation occurred remained constant at 50 °C. The results indicated that all mixtures, particularly R134a + R290, exhibited low discharge pressures, making them advantageous for refrigeration purposes. All of the combinations had coefficient of performance (COP) values that were equal to or greater than those of R1234ze, with some even surpassing it. Overall, the selected blends outperformed R1234ze.