Numerical investigation of the optical efficiency of a parabolic trough collector at different concentration ratios

The Concentration Ratio (CR) is one of the first parameters defined before starting a Parabolic Trough Collector (PTC) construction project as it can easily provide access to the operating temperature and the determination of geometric dimensions. Few studies have been conducted to highlight the importance of the CR. Hence, this work aims to numerically analyze three models of PTC, A, B, and C, with different concentration ratios to perform a comparative analysis of impacts of this parameter in the size and optical efficiency of the models. We used the Monte Carlo Ray Tracing (MCRT) method through the SolTrace software to perform this study. From the results, we conclude that the CR has a considerable effect on the size and optical efficiency of the PTC. On average, the results presented showed that for every gain in PTC optical efficiency, it would be necessary to increase the concentration rate by 2.69%. However, it is noticed that these gains are not linear and decrease as the concentration rate increases. Also, the increase in the CR leads to an increase in the rim angle, in the collector aperture width, and in the solar energy flux density around the absorber. Finally, the results we found were investigated and validated, presenting excellent agreement with other works in the literature.