Evaluating the energy efficiency of a parabolic trough solar collector filled with a hybrid nanofluid by utilizing double fluid system and a novel corrugated absorber tube

Abstract Background Parabolic trough solar collectors (PTSCs) are used to focus the solar rays on absorber tube. The main aim of this paper is to investigate the effects of applying novel corrugated absorber tube filled with hybrid nanofluid on energy efficiency of a novel double fluid PTSC to achieve the maximum energy efficiency value. Method The Eulerian-Eulerian two-phase model is employed for modelling the PTSC and evaluating its energy efficiency. Numerical study is carried out for different values of Reynolds number (Re), nanoparticles volume fraction (ϕ) and geometrical parameters of novel corrugated absorber tube. Findings It is found that usage of corrugated absorber tube has a significant effect on energy efficiency of single- or double fluid parabolic trough solar collectors. Besides it is understood that usage of double fluid system for collector with smooth channel can also increase the energy efficiency, but not more than using corrugated channel for single fluid collector. Moreover, usage of double fluid system at higher Re is also efficient. The results also show that the efficiency of the PTSC enhances with increasing the nanoparticles concentration. Finally, the optimum model of corrugated absorber tube is presented.