Thermal performance enhancement in a solar parabolic trough collector with optimized secondary optics

The current work presents a detailed numerical analysis in a solar parabolic trough collector with optimized secondary optics to enhance the thermal performance of the PTC. The heat flux distribution on an absorber tube of a standard LS-3 collector system was evaluated under different slope error conditions. The obtained heat flux distribution is adopted in the present study for thermal analysis. The simulation is carried out using the ANSYS FLUENT 15.0 tool with standard k-epsilon viscous model and Therminol VP-1 as the heat transfer fluid. The influence of slope error on the thermal performance of the standard and proposed model has been illustrated and investigated in detail. The thermal performance parameters are evaluated for the Reynolds number ranging from 5000 to 50,000 and with three different inlet temperatures of 400, 500 and 600 K. The proposed model has been compared in terms of Nusselt number and friction factor with the standard LS-3 collector. The outcome confirms that the proposed model performs well than standard one. The incorporation of optimized secondary optics exhibited a maximum available and overall thermal efficiency of 92.6 and 84.2%, respectively. The maximum heat transfer coefficient and exergy efficiency of 1481 W/m2K and 52.8%, respectively, was obtained.