Design, modeling, and optimization of a dual reflector parabolic trough concentration system

Abstract

Summary The aim of the present work is to enhance the thermal management avoiding the high‐thermal stress on the outer surface of the parabolic trough receiver (PTR) derived from nonuniform concentrated solar flux distribution. A parabolic trough concentrating (PTC) system with second homogenizing reflector (HR) is numerically designed and optimized to ensure a uniform concentrated solar flux on the PTR walls. For this purpose, a three‐dimensional optical model has been developed to analyze quantitatively the improvement made by the HR using the optical efficiency and qualitatively basing on the uniformity of the solar flux density distribution over the entire surface of the PTR. The validation of the numerical tool is presented, and the algorithm of the design process has been proposed and detailed. As a preliminary trait, it was revealed that the peak of the designed system performance is achieved with a rim angle of 68° avoiding simultaneously the aberration and the blocking effects. Despite the optical efficiency decrease by about 7% compared with the conventional PTC design, the uniformity of the solar flux distribution has been strongly improved such that the maximum local solar flux density gradient is decreased from 80 to 11 kW/m2 equivalent to a decrease of 86.25% with respect to the conventional PTC and the average local density is about 25.5 kW/m2.

Simulated Performance Analysis of a Hybrid Water-Cooled Photovoltaic/Parabolic Dish Concentrator Coupled with Conical Cavity Receiver

“…The investigation of the optical performance of the hybrid PV/PDC-CCR-BSF is carried out with numerical modeling based on the ray-tracing technique (RT 3D-4R) [54,[64][65][66][67]. This method is developed to compute the optical path length and ray intensities for unpolarized electromagnetic waves.…”

Thermal–Optical Evaluation of an Optimized Trough Solar Concentrator for an Advanced Solar-Tracking Application Using Shape Memory Alloy

“…The mirror heats the bottom side of the receiver by focusing the highly concentrated radiation intensity. In contrast, only direct solar radiation heats the top side, making the receiver’s bottom side heated more than the top side; this uneven temperature on the receiver’s outer surface causes high thermal stresses on the receiver side [ 30 , 31 , 32 ]. The temperature variance is considered the primary cause of failure, such as breakage of the receiver’s glass envelope, vacuum leakage or bending within the structure, hence causing optical losses due to the misplacement of the absorber tube from the optimal focal area.…”

“…Moreover, when the receiver becomes damaged frequently and affects other components, the plant’s cost will also be affected. Therefore, with regards to the receiver’s price and reliability, it should be able to function efficiently and work reliably and economically [ 30 , 31 , 32 , 33 ].…”

Coupled optical and thermal analysis of large aperture parabolic trough solar collector

“…Some researchers also investigated the performance of large aperture PTSC 35,40‐44 . Maatallah and Ammar 45 examined the effect of the secondary reflector to minimise the thermal stresses on the receiver tube. The comparison summary of the analysis performed using MCRT and combined MCRT‐FVM for various sun shapes is provided in Table 1.…”