The Research On The Influence Of Wind-break Wall On The Heliostat

The heliostat is a main equipment of solar thermal power generation system. These structures are usually light, flexible and sensitive to wind conditions. The study on wind-resistance of heliostats has become the key issues since the beginning of solar thermal power generation system. Solar thermal power generation systems built in our country have repeatedly had heliostat wind-induced damage accidents. We can introduce the wind-break wall into the design of heliostats wind resistance, determine the reasonable value of the wind-break wall height、wind-break wall porosity rate and the distance between the wind-break wall and the heliostat, to help ease the wind-resistance problem of the heliostats. Based on the heliostat prototype of the Institute of Electrical Engineering of the Chinese Academy of Sciences, this passage has conducted extensive studies on wind-resistance of heliostats.Firstly, the influence of wind-break wall on wind pressure of the heliostat is introduced. Wind-break wall can play the protection function by retardation. We will consider wind-resistance effect from these aspects and study changes of wind pressure at different wind-break wall heights、different wind-break wall porosity rates and different distances between the wind-break wall and the heliostat. It turns out the wind-break wall height、wind-break wall porosity rate and the distance between the wind-break wall and the heliostat will exert great impact on wind-resistance effect.Secondly, non-Gaussian characteristics of fluctuating wind pressure behind the wind-break wall are studied. For regularly single structure, the wind pressure is basically in concordance with the Gaussian distribution; we can get peak factors by Gaussian distribution and then get peak wind pressure which is necessary in the wind-resistance design of heliostats. Because of wind-break wall effect, the wind pressure is not in concordance with the Gaussian distribution within a certain distance behind the wall. We cannot get peak factors by Gaussian distribution. By analyzing the non-Gaussian characteristics, we can get peak factors and then get peak wind pressure, which is necessary in the wind-resistance design of heliostats.Finally, the influence of wind-break wall on wind load values of the heliostat is studied. In order to study wind load characteristics of the heliostat, we can get wind loads using wind pressure of wind tunnel experiment by area weighting, and then get peak wind load values by crest factor. We will study changes of peak wind load values at different wind-break wall heights、different wind-break wall porosity rates and different distances between the wind-break wall and the heliostat. It turns out we can get a better wind-resistance effect when wind-break wall height is 0.8H、wind-break wall porosity rate is 0 and 40%、distance between the wind-break wall and the heliostat is four times of the wind-break wall height.