Performance evaluation of ice plant operating on R134a blended with varied concentration of Al2O3-SiO2/PAG composite nanolubricant by experimental approach

摘要

Performance of an ice plant test rig is investigated experimentally for composite nanoparticles (Al2O3-SiO2) at different volume concentration ranging from 0.02% to 0.1% dispersed in Polyalkylene Glycol (PAG46) lubricating oil utilising R134a as working refrigerant. Performance of the test rig is evaluated on the basis of parameters including: temperature of brine solution in the brine tank (pull-down time), compressor power input, freezing capacity and COP. Temperature and pressure readings acquired using suitable thermocouples and gauges fitted on the test rig is used for the analysis. Refrigerant properties are obtained using REFPROP 9.1 software developed by NIST. Concentration of composite nanolubricant (Al2O3-SiO2/PAG) at 0.08% is found to be optimum owing to lowest compressor power input and highest COP achieved at this concentration. Result shows that the mixture of R134a/composite nanolubricant (Al2O3-SiO2/PAG) worked efficiently in the rig, and performance is found better than operated with either of the nanoparticles dispersed alone in PAG. It is observed that power consumption in the compressor working with composite nanolubricant is found 6.8% and 3.5% less than Al2O3 and SiO2 nanoparticle respectively dispersed alone, whereas COP is found 10.89% and 5.3% more than Al2O3 and SiO2 nanoparticle respectively dispersed alone at 0.08% volume concentration. Total exergy destruction for system working with composite nanolubricant is lowest among all the combinations with value of 0.60 kW. (C) 2020 Elsevier Ltd and IIR. All rights reserved.