Numerical study on solar trough collectors: Optimizing heat transfer with ternary nanoparticles in ionic base fluid and spinning tube fins

The present study investigates the simultaneous influence of ternary nanoparticles in an ionic-based liquid ([EMIM][BF4]) within a parabolic solar trough collector (PTC) tube for heat conveyance. Various types of fins are considered on the inner surface of the receiver tube to enhance turbulence in the flow, thereby improving heat flux distribution and reducing issues related to thermal stress. Using ANSYS 23 Fluent, four cases are simulated, including three with differently structured fins and one representing a traditional PTC tube without fins. Hybrid nanofluids with 1 % volume content, comprising copper oxide, graphene oxide, and aluminum oxide mixed with the ionic base liquid, are examined. The tubes, along with the fins, undergo rotation with spinning rates ranging from 0 rad/s to 15 rad/s, while the flow rate of the working medium varies from 0.15kg/s to 0.60kg/s. Improvements of Nusselt number and thermal performance factor are found as 55.45 %, and 47.45 %, respectively, for Nanofluid-6 than Nanofluid-1 at Re = 4739.30. Enhancement for thermal efficiency is 22.50 % for Case-1 with Nanofluid-6 at 15 rad/s tube spinning speed than 0 rad/s spinning speed. Thus, this study provides crucial insights for selecting the most effective modified model based on its thermal performance, helping to enhance both design and operational efficiency.