Efficacy of turbulator on performance of parabolic solar collector with using hybrid nanomaterial applying numerical method. (October 2022)

• Record Type: Journal Article
• Authors: Jafaryar, M.; Sheikholeslami, M.
• Is Part Of: Renewable energy. Volume 198(2022)
• Page Start: 534
• Page End: 548
• Publication Date: 2022-10
• Subjects: Multi helical tapes -- Parabolic-trough collector -- Hybrid nanofluid -- Numerical technique -- Turbulent regime; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2022.08.037
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: The objective of current work is to find the impact of inserting new multi helical tapes within the pipe of parabolic-trough collector (PTC). In concentrating units, the ranges of temperature are high and for present study, mixture of hybrid nanoparticles (Al2 O3 and MWCNT) and oil was applied as operate fluid. With considering low fraction of each nano-powder, homogeneous model is reasonable for this application with assuming temperature-dependent properties. Simulation of such turbulent flow with considering variable heat flux for outer wall has been done by means of finite volume approach. From verification procedure, it is evident that nice agreement can be achieved if K-ε RNG technique has been selected. Different cases were presented in outputs which depict the influences of pitch ratio (PR), number of segments (NoS) and Re. With augment of both NoS and PR, the hybrid nanomaterial radial speed augments and stronger recirculation makes finer mixing of fluid. Stronger cross flow causes pressure loss to augment and residence time enhances. As inlet speed of hybrid nanofluid intensifies, Nu elevates around 135.54% while friction factor diminishes about 13.085% when PR = 2.5, NoS = 3. With install of helical tape with greater NoS, Nu increases about 10.17% and f increases around 179.57% when PR = 2.5, Re = 5e3. Darcy factor and Nu intensify around 212.35% and 10.43% with elevate of PR when NoS = 3, Re = 1.2e4. Graphical abstract: Image 1 Highlights: New multi helical tapes within parabolic collector have been applied. Mixture of hybrid nanoparticles (Al2O3 and MWCNT) and oil was used. With install of helical tape with greater NoS, Nu increase about 10.17%. Nu intensify around 10.43% with elevate of PR when NoS = 3, Re = 1.2e4.