An innovative numerical approach to enhance parabolic trough collectors’ performance: Integrating low-cost thermal energy storage materials and nanofluids

Abstract

• Numerically assessed PTC performance with low-cost thermal energy storage (TES) materials. • Innovative model closely matched experimental data (1.36 % average absolute relative error). • Investigated spinel oxide nanoparticle-coated quartz sand as TES. • Explored adding CuO, TiO 2 , and Al 2 O 3 nanoparticles to modified PTCs with TES. Parabolic trough collectors (PTCs) are a type of solar thermal technology that harnesses solar energy to generate electricity or heat. PTCs are considered a promising technology for sustainable energy generation, particularly in regions with abundant sunlight. In this paper, an innovative model for a U-tube PTC filled with thermal energy storage (TES) materials is introduced. The Proposed model's validity was first tested by comparing obtained results with experimental data from Kafrelsheikh, Egypt. Consequently, the model was utilized to analyze the changes in thermal performance for various low-cost TES materials, including red brick dust, uncoated and coated quartz sand with two different types of spinel oxide nanoparticles, including CuCr 2 O 4 and Cu 0.5 Cr 1.1 Mn 1.4 O 4 . Also, the TES material achieving best results was tested for different weather conditions, and to explore the capability for improving the thermal performance of the PTC under study, various kinds of nanomaterials, including Copper oxide (CuO), Aluminum oxide (Al 2 O 3 ), and Titanium dioxide (TiO 2 ) were inserted at various concentrations separately and in various combinations into the heat transfer fluid (HTF) of the PTC. The optimal solution was achieved using Cu 0.5 Cr 1.1 Mn 1.4 O 4 -coated quartz sand by compromising both cost and efficiency at which daily average outlet temperature of water, the HTF, was 51.64 °C, achieving an increase of 14.61 % in comparison to the conventional case where no TES materials are added. For the nanofluids case, the study involved calculating and plotting thermophysical properties for different combinations of the mentioned nanofluids at different internal concentrations.