Enhancement of thermal performance in parabolic trough solar Collectors: Investigation of three novel receiver configurations using advanced heat transfer fluids

Abstract

This study investigates the impact of novel receiver configurations and advanced heat transfer fluids on the thermal performance of parabolic trough solar collector receivers, utilising ANSYS Fluent 2021. Three novel configurations (Configs 2, 3, and 4) are compared to a conventional receiver (Config 1) using three different heat transfer fluids: Syltherm800 (reference), MWCTN-TiO₂/Syltherm800, and liquid sodium. Key parameters analyzed include thermal efficiency, Nusselt number, friction factor, and circumferential temperature difference. The model is validated against experimental results and theoretical correlations. Results indicate that novel configurations outperform the conventional receiver, with Config 3 achieving the highest thermal performance. Among the fluids, liquid sodium exhibits the best thermal performance, followed by MWCTN-TiO₂/Syltherm800. Using Syltherm800, thermal efficiency increases by 4%, the Nusselt number by 92.6%, and the friction factor by 167.38%, while the circumferential temperature difference decreases by 56.69%. Compared to Syltherm800, liquid sodium improves thermal efficiency by 3.4 % and the Nusselt number by 45.6%, while MWCTN-TiO₂/Syltherm800 increases them by 2.97% and 32.8%, respectively. Liquid sodium also reduces the circumferential temperature difference by 80.4%, unlike 36.34% for MWCTN-TiO₂/Syltherm800. Additionally, MWCTN-TiO₂/Syltherm800 increases the friction factor by 34%, whereas liquid sodium reduces it by 38.3%. These findings highlight the effectiveness of turbulators in enhancing parabolic trough solar collector performance and demonstrate the advantage of newly developed heat transfer fluids in minimizing the circumferential temperature difference, thereby reducing receiver thermal stresses.