A coupled optical-thermal-fluid-structural analysis of parabolic trough solar collector by deformation coupling instant ray-tracing multiple iteration method

Abstract

Parabolic trough solar collectors (PTC) have been widely applied in concentrating solar power generation and solar heating. During typical operation processes, due to the interaction between the bending deformation and the non-uniform solar flux concentration of the receiver tube, the PTC presents a complex multi-physical coupling phenomenon, which seriously influences the concentrating characteristic and solar-to-thermal conversion efficiency. In order to improve the accuracy of multiphysics simulation, a fully coupled optical-thermal-fluid-structural simulation model is developed by considering the novel structure-deformation coupling instant ray-tracing method. Based on the case study refers to the Euro Trough 150 type collector and the Schott PTR70 type solar receiver, the optical-thermal-fluid-structural coupling characteristics of PTC has been comprehensively investigated. The results indicate that the calculation error of the receiver tube deformation decreases by 16 %, indicating significant improvement in multiphysics coupling. Under the dynamic tracking process, increasing the tracking angle of the adopted PTC module to 90° from 0°results in a corresponding peak solar flux improvement to 73.84 kW/m² from 72.41 kW/m². Due to the thermal stress and gravity, the maximum concavity decreases to 6.64 mm from 9.58 mm and the maximum convexity increases to 1.89 mm from 1.13 mm. This new method provides a feasible reference for optimization and regulation of PTCs.