Performance enhancement of a parabolic trough collector using a segmented receiver insert

Parabolic trough collectors (PTCs) have been studied in great detail to achieve enhanced thermal performance. The most common problem with a PTC is tube wear, which arises because of the uneven temperature distribution around the tube’s circumference. To address this issue, a metallic insert is introduced in the absorber tube to enhance thermal performance and reduce the thermal gradient. A glass tube is employed, and a metallic insert is placed in the tube to reduce the thermal gradient and make the heat flux more uniform. It also acts as a turbulator, enhancing fluid mixing and, as a consequence, reducing the risk of tube deformation and lowering the wall temperature by multistage heating. For the analysis, Syltherm 800 is used as a heat transfer fluid at various flow rates and inlet temperatures. Optical modeling was performed with the ray-tracing tool SolTrace, and thermal performance was analyzed using ANSYS Fluent. The findings reveal that the introduction of an insert enhances turbulence within the tube, leading to an increase in the Nusselt number by 33.6%, while the friction factor increases by 13.2%. Overall performance evaluation criterion ranged from 1.06 to 1.02 with increasing flow rate, indicating a net positive performance.