HEAT TRANSFER RESEARCH, cilt.54, sa.2, ss.25-37, 2023 (SCI-Expanded)
Passive methods are preferred in cooling systems and the development of these methods is one of the most important issues in terms of energy efficiency. Improving heat transfer in cooling systems by using solid-liquid and solid-gas suspensions instead of the base fluid is a crucial passive method. The compressor in the system was operated with nanolubricants in different mass fractions, and the cooling system was filled with a hybrid nanorefrigerant. The applications of nanolubricants and nanorefrigerants, the concentration of nanoparticles as an additive material in tribological tests, their compatibility with the particle type, base fluid, and surfactant are important parameters. In this context, silicon carbide (SiC) and silicon nitride (Si3N4) nanoparticles were preferred due to their compatibility and superior tribological properties in terms of contact area and wear mechanism. The results show that the addition of nanoparticles to the compressor oil and refrigerant has a positive effect on the system performance when nanolubricant with a mass fraction of 0.34% in polyol ester (POE) and hybrid nanorefrigerant with a mass fraction of 0.055% were used. With the use of nanoparticles, the coefficient of performance (COP) of the system increased by 21.82% compared to pure POE.