Performance Evaluation of Household Refrigerator using CuO Nanoparticle Lubricant Mixture and various Compressor Oils with Different Condenser Modes

The objective of this paper was to study the performance of household refrigerator with 0.06%<br>mass fraction CuO nanoparticle-lubricant mixture and different types of compressor oil having both air-cooled<br>and water-cooled condenser. The experiment was done using HFC134a as the refrigerant, CuO nanoparticles,<br>Polyol-ester oil (POE) oil which is used as the conventional lubricant in the household refrigerator and SUNISO<br>3GS mineral oil as the lubricant alternatively. The result indicates that the refrigerator performance had<br>improved while using CuO nanoparticle-lubricant mixture. The performance was also improved when<br>HFC134a/SUNISO 3GS mineral oil system was used instead of HFC134a/POE oil system and there was also an<br>enhancement when water-cooled condenser was used instead of the conventional air-cooled condenser on all<br>load conditions. The HFC134a/CuO/SUNISO 3GS mineral oil system works normally and safely in the<br>refrigerator. HFC134a/CuO/SUNISO 3GS mineral oil system reduced the energy consumption between 12% and<br>19% when compared with the HFC134a/POE oil system and between 9% and 14% while working with watercooled condenser on various load conditions. There was also an enhancement in coefficient of performance<br>(COP) when CuO nanoparticle-lubricant mixture was used instead of POE oil as the lubricant. The water<br>cooled heat exchanger was designed and the system was modified by retrofitting it, along with the conventional<br>air-cooled condenser by making a bypass line and thus the system can be utilized as a waste heat recovery unit.<br>Experimental result shows that about 200 litres of hot water at a temperature of about 58ºC over a day can be<br>generated.