Dynamic Response Characteristics of Heliostat Impacted by Continuous Hails

Abstract

The Tibet Plateau is an area with abundant solar energy resources. However, it is also a location where severe thunderstorm disasters, for instance hail, frequently occur. In this paper, the dynamic response of the heliostat under impact by continuous hails was investigated. The effects of time interval of hail impact, hail diameter, impact position, as well as random multi-hail impact and random multi-hail distribution density were studied on the dynamic failure assessment of heliostat under continuous hail impacts. Results indicate that the continuous impact of hail on the same position of the heliostat causes a superposition effect on the heliostat. In case where larger-diameter hail initially impacts the heliostat, followed by smaller-diameter hail impact, the maximum principal stress in heliostat reaches its peak after the first hail impact and then steadily declines. When the heliostat is hit first by small-diameter hail followed by larger-diameter hail, it causes more damage to the heliostat compared to the case when the impact sequence is switched. The distance between continuous hail impacts reduces the increase of the maximum principal stress of the heliostat while increases the displacement value at the impact point of the heliostat. When the hail density increases by twice, the maximum principal stress increases significantly. The larger the hail distribution density, the smaller the stress concentration area, and then it gradually expands to both ends over time.