Optimizing thermal efficiency of parabolic trough solar collectors through internal fins integration and specialized distribution

This investigation involves a numerical simulated combined Monte Carlo Ray Tracing (MCRT) method and Computational Fluid Dynamics (CFD) modeling within a modified parabolic trough solar collector, incorporating a novel design of inserted fins in the absorber tube. The primary objective behind integrating these fins into the absorber tube is to enhance the efficiency of the heat transfer process. Tri-dimensional simulations are conducted to thoroughly analyze fluid dynamics, model the physical process and especially analyze the effect of varying geometric and operating conditions. The proposed innovative configurations offer better temperature distribution than the smooth absorber tube where the inserted fins ensure adequate fluid flow mixing between the hot tube wall (exposed to concentrated heat flux) and the lower temperature tube (face exposed only to direct irradiation). The effect of the inserted fins spacing on the thermal performance of the Parabolic trough collector (PTC) is deeply studied and results are compared to that of conventional PTC’s tube. After identifying the optimal configuration and determining the appropriate fins spacing value, the corresponding configuration was retained and a new approach was applied. Indeed, various fin arrangements were examined and the better configuration, that presents lower pressure losses, was evaluated. This parametric study clearly shows the advantage of the use of internal fins in the region where the flow is fully developed. PTC system studied (a) and different designs of the fins equipped receiver (b).