Simulation study of heat transfer behaviour of turbulent two-phase flow in a 3D cubic shell and tube heat exchanger using water and different nanofluids

This research utilizes a two-phase flow model to replicate the thermal exchange in a counter flow shell and tube heat exchanger, comparing the efficacy of different nanofluids against pure water. The shell space is represented as a closed cubic area filled with diverse fluids, while the tube functions as the thermal exchange component. It investigates parameters like nanofluid variations, nanoparticle dimensions, and volume ratios to enhance the efficiency of temperature exchange between the shell and tube fluids. The Reynolds-averaged Navier-Stokes (RANS) technique is employed to analyze turbulence within the heat exchanger, utilizing ANSYS@FLUENT (Version 2022 R1) for simulations, which were considered reliable when convergence criteria reached 10(-5). The outcomes are assessed based on velocity, thermal conductivity, Nusselt number, temperature dispersion, and turbulent kinetic energy. Notably, the results underscore that integrating nanoparticles into the fluid amplifies its thermal conductivity, with higher concentrations yielding more significant enhancements. Nanofluids, particularly those comprising SiO2-H2O with small nanoparticles and high volume fractions, exhibit notable improvements in heat transfer compared to pure water. TiO2-H2O follows in second place, trailed by CuO-H2O and Al2O3-H2O. The application of the RANS method effectively elucidates turbulence patterns and their impact on heat transfer dynamics between the shell and tube. An increase in Reynolds number has shown an adverse effect on heat transfer. Overall, this study furnishes valuable insights for optimizing heat transfer performance in such systems.