Heat Transfer Characteristics of Al2O3 Based Nano refrigerants in The Evaporator and Condenser of Vapor Compression Refrigeration Systems

The performance and energy consumption of the vapor compression refrigeration system (VCRS) is influenced by the rate of heat transfer between the system and its environment. Two-phase flow, boiling with heat transfer occur within the evaporator and the condenser of the VCRS. The improvement in two-phase flow, boiling and heat transfer coefficient in these components using nano refrigerants possess the propensity to increase the system’s performance and energy efficiency and reduces the energy carbon footprint of the system. The influence of nanoparticle concentration of aluminum oxide (Al
2
O
3
) on the two-phase flow heat transfer in the condenser and the evaporator using R134a and R600a refrigerants in the VCRS was analyzed in this study. The ANSYS fluent software was employed to model and analyze the process in the condenser and evaporator. The result obtained showed that convective heat transfer of pure R600a and Al
2
O
3
/R600a nano refrigerants was higher than that of pure R134a and Al
2
O
3
/R134a nano refrigerants. The Prandtl and Nusselt numbers decreased as the nanoparticle concentration increased. Thermal diffusion was more prominent than the momentum diffusion as the temperature increased, despite the increase in the nanoparticle concentration. The numerical simulation results established that the convective heat transfer coefficient, Nusselt number and Prandtl number of the nano refrigerant depends on the mass concentration of nanoparticles.