Thermohydraulic and thermodynamics performance of hybrid nanofluids based parabolic trough solar collector equipped with wavy promoters

Abstract

This article presents a numerical analysis on the thermohydraulic and thermodynamic performance of a parabolic trough solar collector (PTSC) receiver's tube equipped with wavy promoters. A computational fluid dynamics (CFD) with the aid of finite volume method (FVM) is adopted to examine the flow and thermal features of the PTSC's tube receiver. The Reynolds number in the range of 5000–100000 with four fluid inlet temperatures in the range of 400–650 K are utilised. Three different advanced hybrid nanofluids (Fe2O3-GO, Fe2O3–SiC and Fe2O3–TiO2) dispersed in Syltherm oil 800 are employed inside the PTSC's receiver tube. The numerical outcomes are verified with the available correlations and with other numerical and experimental data available in the open literature. The numerical results reveal that the utilisation of wavy promoters inside the PTSC's receiver tube can significantly augment the thermal performance, where the average Nusselt number is improved by 150.4% when utilising Fe2O3-GO/Syltherm oil hybrid nanofluids at 2.0% concentration instead of Syltherm oil. Furthermore, the maximum reduction in the absorber's average outlet temperature is in the range of 7–31 °C. The overall thermal evaluation criterion (PEC) is found to be in the range of 1.24–2.46 using bricks-shaped nanoparticles. The results show that the thermal efficiency increased by 18.51% and the exergetic efficiency increased by 16.21%. The maximum reduction in the entropy generation rate and the entropy generation ratio are about 48.27% and 52.6% respectively. New correlations for Nusselt number, friction factor and thermal efficiency for PTSC tube having wavy promoters using hybrid nanofluids are developed.