Energetic and exergetic analysis of a Vapour compression refrigeration test rig in varying concentrations of (TiO2-SiO2/MO) hybrid nano-lubricants and R600a refrigerant charges

Abstract

ABSTRACT Every residential refrigerator employs a Vapor Compression Refrigeration (VCR) technology. The performance of a VCR system is mostly determined by the input power and refrigeration effect. In present study, effects of varying concentrations of TiO2-SiO2/MO hybrid nano-lubricant (0.1, 0.2, 0.3, and 0.4 g/L), and mass charge of refrigerant R600a (80, 100, and 120 g) investigated by the authors. The performance parameters of the VCR test rig optimized at 0.2 g/L of hybrid nano-lubricant concentration using 100 g mass charge of R600a refrigerant. At this optimum condition, the percentage increase in coefficient of performance was 37.83% compared to the pure lubricant using 80 g mass charge of R600a refrigerant. The percentage reduction in input power at optimum condition was 13.46% compared to pure lubricant case using 80 g R600a, refrigerant mass charge. The maximum value of second law efficiency and the least value of exergy lost were found at 0.2 g/L concentration of hybrid nano-lubricant using 100 g charge of R600a refrigerant, with values of 77% and 96.90W, respectively. In conclusion, performance of VCR test rig altered when the concentrations of hybrid nano-lubricant and refrigerant mass concentrations changed.