Simulation of a parabolic trough solar collector containing hybrid nanofluid and equipped with compound turbulator to evaluate exergy efficacy and thermal- hydraulic performance

Abstract

This research is mainly aimed at investigating the numerical modeling of thermal- hydraulic and exergy efficiencies of parabolic trough solar collectors (P- SCs) filled with magnetic hybrid nanofluid. The k- epsilon turbulence, S2S, and mixture models were used to simulate the turbulence equations, radiation, and two- phase nanofluid, respectively. The experiments were run using mag-netic nanofluid in Reynolds numbers of 5000- 20 000, the volume fractions of 1%- 3%, and the ratios of pitch (ROPs) of 1, 2, and 3 of the combined turbula-tor. According to the results, there is a significant increase in average Nusselt number (Nu) and pressure drop (ΔP) with increasing Reynolds number, nano- additive concentration, and ROP. Moreover, the use of the hybrid magnetic tur-bulator and hybrid nanofluid increased the thermal performance of the P- SC. It was also found that the Reynolds number of 20 000 and volume fraction of 3% of nanoparticles resulted in the optimal exergy efficiency mode in using a hybrid turbulator.