Assessment of TiO₂, Al₂O₃, and SiO₂ nanolubricant with eco-friendly refrigerant as substitute for R134a in a vapour compression system: An experimental approach

The efficiency of R600a, an eco-friendly refrigerant with TiO₂, Al₂O₃, and SiO₂ nanolubricants, was investigated and evaluated as a substitute for R134a in a vapour compression refrigerator system. Pressure gauges and K-type thermocouples were used to monitor the temperature and pressure. The power consumption of the refrigerator was observed using the digital wattmeter. Using NIST refprop version 9.0, the refrigerant's enthalpy was determined. The results showed that R600a with nanolubricant TiO₂, Al₂O₃, and SiO₂ had lower evaporator temperatures and pull-down times than R134a and pure R600a. For R600a in the based lubricant, TiO₂, Al₂O₃, and SiO₂ nanolubricant concentrations in the system, respectively, evaporator temperatures of − 5, − 10, − 7, and − 11 °C were attained after 210, 210, 240, and 240 min of pull-down time. TiO₂, Al₂O₃, and SiO₂ nanolubricants increased R600a cooling capacity by 9.7%, 0.5%, and 12.2%, respectively, while lowering power consumption by 23.3%, 17.5%, and 20.2%. R600a/nano mixtures can therefore replace R134a and R600a with pure lubricant in a household refrigerator system.