Optical, thermal, and structural performance analyses of a parabolic-trough solar collector

Parabolic-trough solar collectors are widely used in solar thermal power-generation stations because the structure is simple and inexpensive. However, many factors affect their performance. Here, we derive an optical-thermal-structure numerical method. The heat flux is unevenly distributed along the circumferential direction of the absorber tube, resulting in uneven temperature distribution. An area of stress concentration is apparent at a rim angle of about 75°, and the maximum von Mises stress is approximately 100 MPa, near the fixed end of the tube. As the geometric concentration ratio increases, the position of maximum heat flux gradually moves to the bottom of the tube. An increase in this value increases the heat transfer fluid temperature, and the stress on the tube rises as the temperature distribution becomes more inhomogeneous. As the rim angle increases, the position of maximum heat flux gradually shifts to the sides of the tube. The stress on the tube then decreases because the temperature distribution becomes more uniform. The performance of a parabolic-trough solar collector can be improved by changing the geometric concentration ratio and rim angle, taking care to ensure no material failure. Optical, heat transfer, and thermal stress analyses of a parabolic-trough solar collector were systematically performed. This study provides guidance for practical engineering applications of parabolic-trough solar collectors.