Numerical Analysis by CFD of the Boiling Process and the Behavior of Aluminum Oxide Nanoparticles in Refrigerants R600a and R290

The objective of this research presents the CFD numerical analysis of nanofluids, with the intention of increasing the heat transfer coefficient of refrigerants R600a and R290 in the boiling process when aluminum oxide nanoparticles with a fraction of volume equivalent to 5%. The study considered the boiling process in the evaporation of refrigerant fluids R600a, R290 and nanorefrigerants R600a/Al₂O₃, R290/Al₂O₃ to a temperature of −15 ^∘C, taking into account that the fluids flow at a speed of 1.5 m/s through a heat exchanger, said exchanger has the shape of a straight tube which has an internal diameter corresponding to 7.899 mm and a length of 1000 mm, this device is subjected to a heat flow of 20 kW/m² which will be constant along the tube wall. Consider that the inlet temperature of the fluids to the heat exchanger is −16 ^∘C and they are in the liquid phase. The numerical analysis was feasible from the use of the ANSYS FLUENT, in this study the Eulerian model for multiphase flows and the RNG k-epsilon model were used to obtain heat transfer results on curved surfaces.