Improving overall heat transfer performance of parabolic trough solar receiver by helically convex absorber tube

The parabolic trough collector (PTC) system has been widely applied in concentrating solar power (CSP) technology. The absorber tube of PTC has a significant impact on the solar energy conversion efficiency. In order to improve the overall heat transfer performance of PTC system, the idea of using helically convex tube as a metal absorber tube of the parabolic trough receiver (PTR) is proposed. Combined with Monte Carlo ray tracing method, the Finite Volume Method is used to establish the numerical analysis model. The effects of structural parameters (p, h, and r) of helically convex absorber tube on the heat transfer and flow performance are studied. The results show that by designing the helically convex structure of tube, the heat transfer and flow properties of parabolic trough receiver can be effectively optimized. Compared with the traditional PTR, the overall heat transfer performance is improved by up to 34%.