Investigation of the Thermo-hydraulic performance of a roughened Parabolic trough collector

Parabolic trough collectors (PTC) are an already established technology set to prove its competitiveness. Recently, a lot of research is ongoing to further enhance the thermal performance of PTC systems. Computational Fluid Dynamics (CFD) can help in the design and development of PTCs with optimized thermal efficiency. In the current work, a combined enhancement in the performance of a PTC is evaluated, involving modifications to the geometry of the absorber tube and the use of a heat transfer fluid (HTF) (Syltherm800). Absorber tube geometries involving dimpled protrusions (D-PTC) and circumferential inclined ribs (IR-PTC) are used. The performance of PTC with and without turbulators is compared with that of a smooth absorber tube by calculating the Nusselt number (Nu), friction factor (f) and performance evaluation criterion (PEC). PEC values of 1.46 and 1.18 are observed by using inclined ribs and dimpled protrusions, respectively at an absorber tube inlet temperature (Tin) of 500 K and mass flow rate (m) of 0.5 kg s-1. Thus, a significant enhancement in thermo-hydraulic performance of PTC is observed with inclined rib turbulators.