Volume 67

Increasing the Energy Efficiency and Exergy of a Solar Collector Using Turbulators and Nanofluids Inside the Absorber Tube Negin Beigi, Amir Safari

Abstract

The limited availability of fossil fuel resources and the environmental issues caused by greenhouse gas emissions have underscored the need to adopt renewable energy sources, particularly solar energy. Improving the efficiency of solar energy systems increases productivity, reduces fuel and electricity consumption, and improves air quality. In this study, the governing equations were numerically solved in ANSYS Fluent using the finite volume method (FVM) with the k-ω-SST turbulence model. The thermal–hydraulic performance of a parabolic trough solar collector was investigated using a water-based CuO-SWCNT hybrid nanofluid at nanoparticle volume fractions of 1%, 2%, and 4%, and Reynolds numbers ranging from 4000 to 10000. Two modified twisted tape turbulators with different V-cut numbers and angles were examined. The results showed that the twisted tape with three V-cuts achieved the highest performance evaluation coefficient (PEC) and improved collector efficiency compared to the two-cut design, particularly at higher Reynolds numbers.

Keywords Parabolic solar collector, twisted tape, hybrid nanofluid, performance evaluation coefficient