Performance of a domestic refrigerator using selected hydrocarbon working fluids and TiO2–MO nanolubricant

•TiO2 concentration significantly affect thermo-physical properties of TiO2/MO Nano lubricant.•Energetic performance of domestic refrigerator varies directly with nanolubricant viscosity.•Energetic performance of R600a driven refrigerator is found better than LPG.•Compressor Discharge temperature with R600a is found lower than LPG.•Significant improvement in pull-down time is observed with R600a driven refrigerator. In this work, the steady state energetic performance of selected mass charges (40, 60 and 80 g) of R600a refrigerant and varying concentrations of TiO2 based nano-lubricant (0, 0.2, 0.4 and 0.6 g/L) within a domestic refrigerator was investigated and compared with the performance of a domestic refrigerator using LPG refrigerant from authors’ previous publication. Additionally, the effect of the TiO2 concentrations on the thermo-physical properties of the nano-lubricants under similar conditions was investigated. The results reported compressor discharge temperature, compressor power consumption and pull-down time within the R600a-based refrigerator were lower by about 41.92%, 33.33% and 21.05% respectively compared to the LPG-based refrigerator. Moreover, refrigeration capacity and COP of the R600-based refrigerator were higher when compared to LPG-based refrigerator, by about 17.39% and 62.54% respectively. Overall, energetic performance of the R600a-based domestic refrigerator was better than that of baseline (LPG) at optimal concentration of 0.2 g/L of TiO2 and 40 g charge of R600a refrigerant, under similar operating conditions.