A PROCESS FOR DETERMINING LUBRICANT COMPOSITION IN A VAPOR COMPRESSION REFRIGERATION SYSTEM TO ENHANCE THE CO-EFFICIENT OF PERFORMANCE

摘要

The invention relates to a process for determining lubricant composition in a vapor compression refrigeration system to enhance the co-efficient o performance, the system comprising a hermitically sealed compressor, a condenser, a capillary tube including an evaporator cabin for cooling of water, a plurality of thermocouples, at least four pressure gauges, and a digital energy meter, the system being operable with different varieties of refrigerants and a mineral oil as the lubricant, the process comprising the steps of preparing a nano-fluid sample in an ultrasonic agitator by dispersing TiO2 nanoparticles having average particle size of 40 nm in a mineral oil; preparing a plurality of volume fractions of nano-fluid by varying the volume fraction of the nanoparticles and maintaining the volume of the mineral oil as the base fluid as constant; determining the kinematic viscosity of the base fluid and the nanoparticles in a viscometer including the variation of the kinematic viscosity of the different volume fractions of the nanofluid samples; identifying an optimum volume fraction of nanoparticles mineral oil mixture based on a minimum friction co-efficient value in a pin-on desk tester having a digital meter; and validating the identified optimum volume fraction of the nanofluid capable of enhancing co-efficient of performance of the refrigeration system when used as the lubricant, the validation being carried-out in a speckle interferometer which determined optical roughness index (ORI) value representing the effect of volume fraction of nanoparticles in the mineral oil.