Wind Resistence Performance Analysis On Heliostat And Curtain

Several heliostats appeared wind-induced local failure in our country. Therefore, we need to do some theoretical and experimental reasearch on wind resistance design of helioststs in order tosatisfying the reliability of heliostats. By studing, we can get wind load parameters, propose realistic calculation methods of wind-induced response and develop design criterias in line with our national standards. Our group participated wind resisitence performance analysis on heliostats of Asia’s first MW-class solar tower thermal power stations. A series of research work have been done and the following findings have been completed.(1)Proposing some methods for determining wind loads on heliostats:By wind tunnel model testing, theoretical analysis and numerical simulation, we have obtained wind pressure distribution characteristics, propoesd wind load formulas of heliostats, completed depth analysis of these formulas’parameters and obtained characteristics of whole force of heliostats in different wind directions. And then, we studied characteristics of fluctuating wind pressure and caculated equivalent wind loads by using GBJ method, multi-modal force method and time-domain analysis method. Through these analysis, we obtained wind-resistant design parameters of heliostats(2)Seting up calculation methods on wind effect of heliostats:Taking the model of a heliostat in wind tunnel as example, the paper derives formulae for spatial wind-induced dynamic response of heliostat using Davenport wind spectrum. The paper presents empirical expressions of power spectrum density on the mirror surface of the heliostat by testing heliostat model in a wind tunnel. It is verified by an example that the accuracy of the power spectrum density of fitting is acceptable and it provides the reference basis for the structure wind-resistance design.(3)Solving key issues on wind resisitence design of heliostats:By wind tunnel model testing, theoretical analysis and numerical simulation, we studied the influence of mirror panels gap on wind loads, wind pressure distribution, dynamic characteristics and wind-induced response of heliostats. And then, we studied favorably wind-resistant park profile of heliostats. At last, we completed dynamic optimization design of heliostats. A mathematical optimization model was set up to minimize volume of steel of heliostats. Some optimization measures were proposed.The damage of curtain walls would occur frequently affected by wind loads. We built test equipments for wind effect analysis of curtain walls and completed the reasearch of wind-induced deflection and stress of curtain walls. At last, we raised calculation methods of dynamic effects of curtain walls. A series of research work have been done and the following findings have been completed.(1)Proposing a new analysis method on wind effect of curtain wallsThrough experiments, we studied wind-induced stress of glass panels and wind-induced deflection of curtain wall frames and glass panels. And then, we studied tensile deformation of window locks of curtain walls under negative wind pressure. We compared wind-induced stress of windward side and leeward side of curtain walls, compared wind-induced stress of measuring points at different positions of glass panels and compared wind-induced stress of open glass panels and closed glass panels. At last, we proposed a new analysis method on wind effect of helioststs.(2)Proposing a new calculation method of wind effects of glass panels of curtain walls:Based on small-deflection thin plate flexure theory, we studied dynamic displacement theory of rectangular thin plate. And we assumed that glass panels under dynamic loads were simple propping rectangular plates under uniform harmonic loads. By calculating and studying, this assumption is consistent with the actual wind effects of glass panels of curtain walls.