Performance characterization of nano-enhanced PV/T systems in various cross-sections, extended flow turbulators, fins, and corrugated patterns

Abstract

Photovoltaic thermal (PV/T) systems may generate both heat and electricity from the sun. Modifying the collector's thermal performance by passive methods is a reliable approach to making them more effective. This study compares the impact of different cross-sections, extended surface turbulators, fins, and corrugated patterns based on the ISO criterion when the working fluid is enriched by MWCNT-water nanofluid at φ=0.3%. The multi-angle yet passive techniques used here, including the nanofluid in Longitudinal Fin (LF), Flat Plate Turbulator (FPT), Wedge Plate Turbulator (WPT), Triangular Corrugated Channel (TCC), and Wavy Corrugated Channel (WCC), and smooth channels, improve the optical efficiency (η0) and reduce the heat-loss coefficient (a1) by 6.8 % and 19.6 %, 12.5 % and 29.3 %, 12.5 % and 27.7 %, 11.7 % and 23.6 %, 10.81 % and 22.9 %, and 3.2 % and 10.71 % compared to the base case (i.e., the smooth channel with pure water) respectively. Pump power in WCC, TCC, and LF is negligible, leading to enhancement in electrical efficiency (ηelec) up to 4.7 % for the former two and 2.9 % for the latter cases. However, plate turbulators show a decline in ηelec at higher inlet velocities due to increased pressure drop. A parametric study of FPT reveals that reducing height and periodic ratios effectively decreases pump power while slightly affecting the performance parameters (η0anda1). The system's performance is also evaluated using the overall exergy efficiency (ηex,ov) concept. The study finds the FPT configuration with the highest ηex,ov of 16 %.