Caracterização de nanofluidos para utilização em compressores de refrigeração: determinação da viscosidade dinâmica, condutividade térmica e estabilidade.

Abstract

This paper identifies the dynamic viscosity and the thermal conductivity three nanofluids (NFs) mineral oil base ISO 32, used in domestic refrigeration compressors, additivated respectively by nanoparticles (NPs) of carbon nanotubes (NTC), niobium oxide (Nb2O5) and Indian (In).After analyzing the thermo-physical properties, investigates the stability (NFs) by specific methods and then is compared the tribological performance of the most stable sample by high frequency reciprocating rig. The results demonstrated that the dynamic viscosity has insignificant change, the thermal conductivity has significant gain with respect to the pure oil and that (NFs) of (NTC) and (In) have good and reasonable stability respectively, while the compounds additivated with (NPs) of (Nb2O5) are unstable and are not viable for use in thermal systems. The (NFs) of(NTC) when compared with the pure oil showed higher lubricant film thickness, lower coefficient of friction and lower average wear