Evaluation of thermal and rheological characteristics of CNT-PAG nanolubricant for the development of energy efficient refrigeration systems

Abstract

The addition of nanoparticles is one of state of the art methods to enhance the thermophysical and heat transfer characteristics of cooling and lubricating fluids. Exploring the energy-saving potentials of novel material Carbon Nano Tube (CNT) as a lubricant additive is the primary focus of this study. The thermal and rheological properties of Poly Alkylene glyco l (PAG)-CNT nanolubricant at different volume fractions are investigated to pose as an energy-efficient alternative lubricant in vapour compression refrigeration systems. Furthermore, genetic algorithm-based regression correlations are proposed to predict the thermal conductivity and viscosity of the nanolurcant. The results show that the CNT has the potential to improve the thermophysical and rheological characteristics of the lubricant. Experimental results show that the presence of tubular-shaped CNT particles enhances the thermal and rheological characteristics of the colloidal suspension. The proposed regression models exhibit excellent agreement with the experimental data. Studies revealed that the potentials of CNT-PAG nanolubricant as an alternative lubricant for refrigerant compressors is excellent and will eventually improve the energy efficiency and overall performance of refrigeration systems and which in turn leads to the development of energy-efficient HVAC systems.