ENHANCEMENT OF EXERGY EFFICIENCY IN VAPOR COMPRESSION REFRIGERATION SYSTEMS USING WO3-BASED NANOLUBRICANTS

Minimizing compressor power consumption is a critical challenge in vapor compression refrigeration systems. Recent studies have explored the potential of hybrid nanolubricants to enhance energy efficiency in compressors. This study evaluates the performance of a refrigeration system using synthesized tungsten (VI) oxide (WO<sub>3</sub>)-based nanolubricants due to their excellent thermal stability, tribological properties, and compatibility with lubricating oils. Cobalt (Co), nickel (Ni), and copper (Cu) nanoparticles were doped onto WO<sub>3</sub> via a wet impregnation method to produce Co/WO<sub>3</sub>, Ni/WO<sub>3</sub>, and Cu/WO<sub>3</sub> samples. Experimental analyses were conducted at nanolubricant mass fractions of 0.3%, 0.6%, 0.9%, and 1.2%, with Triton X-100 surfactant (0.5%) to stabilize the suspensions. Exergy analysis indicated that the highest efficiency was achieved with Co/WO<sub>3</sub> at a 0.9% mass fraction, resulting in a 17% increase in exergy efficiency. Additionally, using Co/WO<sub>3</sub> nanolubricant as the working fluid in the compressor improved the coefficient of performance (COP) by 41.62% compared to conventional polyalkylene glycol (PAG) oil.