Cooling of a solar panel using nanofluid turbulent flow to improve energy and exergy efficiencies: Optimizing and simulating the effect of rectangular pin-fin height

Abstract

BackgroundDue to increasing progress of the industry, enhancing rate of heat transfer with passive procedures has been the focus of researchers. One of these procedures is employing of pin-fins with varied shapes to disturb flow and enhance heat transfer rate. This study examines impact of rectangular pin-fins by varied heights and two-phase MgO-SiO2/water hybrid nanofluid (NF) on efficiency of the solar collector employing finite volume method (FVM). MethodsSolidwork software is employed for geometry modeling of the solar collector with rectangular pin-fins. Also, ANSYS FLUENT 2022 software is employed for numerical simulations. To ensure the obtained results, the grids with different elements are utilized to estimate average Nusselt number (Nuave) considering steady nanofluid flow. The MgO-SiO2/water hybrid NF is simulated employing the two-phase mixture model. The RNG k-ε turbulence model is employed to model turbulent flow. The inlet Reynolds number (Re) alters from 7000 to 31,000 and volume fraction (φ) varies from 1 to 3% when height of the pin-fins is 8, 10, 12, and 14 mm. ResultsThe pressure drop and mean Nusselt number are strongly influenced by velocity and volume fraction of nanoparticles (NPs) at inlet of solar collector. When φ = 3% and Re = 31,000, adding rectangular pin-fins with a height of 14 mm causes the Nuave to enhance by 133.81% compared to collector without pin-fins. For solar collector with rectangular pin-fins with a height of 8 mm, the energy efficiency is increased by 26.91% by enlarging Re from 7000 to 31,000 when φ = 3%. For solar collector with rectangular pin-fins with a height of 14 mm, the exergy efficiency is enlarged by 36.60% by enlarging Re from 7000 to 31,000 when φ = 3%.