Study on the dust deposition behaviors and laws of trough solar reflectors

Trough solar reflectors are widely applied in solar thermal power generation, especially in arid and desert regions with abundant solar resources where dust accumulation is prevalent. However, particle deposition on trough solar reflectors significantly reduces the optical performance and efficiency. In this study, the computational fluid dynamics–discrete phase model method is used to establish a particle deposition model for trough solar reflectors. The air flow field structure and the particle motion and deposition processes are analyzed. Additionally, the effects of different conditions on particle deposition laws are investigated. The results indicate that the air flow field structure includes five regions. The low-pressure and low-velocity region is distributed behind the reflectors and within the reflector spacing with air flow separation, settling, and refluxing. Particle deposition occurs when the influences of gravitational, van der Waals, and electrostatic forces are greater than those of the drag, collision, Magnus, and Saffman forces. The minimum particle deposition rate on the reflectors occurs when the angle of inclination is approximately 36°, where the increasing drag effect gradually balances the decreasing influence of collision-related forces. Increasing the array row number greatly reduces the particle deposition rate except in the fourth row, where enhanced wake recirculation increases particle residence and deposition near the reflector surface. Decreasing the array spacing without affecting the focusing effect of the reflectors can mitigate the negative influence of dust deposition. The study can provide an important theoretical basis for reducing dust deposition on trough solar reflectors.