Estudo experimental de nanofluido hídrico Al203-MWCNTs/POE

Abstract

The development of solid nanoparticles and their dispersion in a base-fluid to improve thermomechanical properties and intensification of heat transfer processes is a branch of science that has aroused much interest from the scientific community and boosted several industry segments in recent decades. In this context, it is proposed to investigate a new hybrid nanofluid from the addition of nanoparticles of alumina (Al203) and multi-walled carbon nanotubes (MWCNTs) to a polyetherlubricating oil (POE), originally developed for application in refrigeration compressors. The nanoparticles of Al203 and MWCNTs were dispersed in 50/50 ratio in POE oil at concentrations of 0,10 g/L, 0,25 g/L, 0,50 g/L and 1,00 g/L. The hybrid nanofluid Al2O3-MWCNTs/POE was subjected to ultrasonic sonication by immersion probe and rotating magnetic stirring to improve stability. Thermal, rheological and lubricity properties were measured in the concentration range of 0- 1.0% and temperatures of 20 0C to 80 0C. The thermal conductivity of the hybrid nanofluid at the concentration of 1,00 g/L was slightly higher than the POE oil at all temperatures. The dynamic viscosity and HFRR lubricity of the hybrid nanofluid did not show significant variations in relation to the POE oil. Finally, the hybrid nanofluid Al2O3-MWCNTs/POE at the concentration of 1,00 g/L showed the best set of thermophysical properties.