作　　者： ; ; ; ;

机构地区： 湖南大学土木工程学院

出　　处： 《振动工程学报》 2008年第5期458-464,共7页

摘　　要： 定日镜是塔式太阳能发电系统中的重要设备，其结构轻巧，对阵风反应敏感，设计中应着重考虑风荷载的作用。由于定日镜体型特殊，使用时处于多种工况工作状态，需要对其在风荷载作用下的响应进行专门研究。因此对定13镜刚性模型进行了三维风荷载风洞试验，得到定13镜在竖向转角0°～90°（每10°一次定位），风向角0°～180°（每15°测量一次）范围内共130种工况下，镜面表面脉动风压时程数据。建立有限元模型对定日镜结构进行模态分析和风振响应计算。通过计算得到了风振位移响应峰值，并且从镜面表面脉动风成因入手深入研究了结构动力反应的规律，结果表明，竖向转角较小时，整个镜面各部分背景响应值接近，镜面底部存在多阶共振反应；随着转角θ增大，空气在靠近镜面的一方分离，在远端再附着，形成脱落旋，镜面上部的动力响应增加。文章还对有代表性的工况进行了结点位移反应谱分析，汇总出多种工况下定日镜表面风压风振系数，为结构设计提供依据。 Heliostat is the key part of Solar Tower power station. It＇s apt to gust because of its light structure, so the effect of wind load should be taken into account in design. The structure of heliostat is unusual and it often works under several situations, and specialized researches are needed on its response to wind load. Experimenting on rigid model of heliostat using technique of 3-dimensional wind load in wind tunnel, data of surface fluctuating wind pressure＇s time intervals under 130 phases among which elevation angle varied from 0° to 90° （with step of 10°） and wind direction angle varied from 0° to 180° （with step of 15°） were obtained. A finite element model was constructed to perform mode analysis on heliostat and wind-induced dynamic response calculation, the wind-induced displacement＇s peak values are given, and moreover, the further research on structure dynamic response law from aspect of cause of the mirror＇s surface fluctuating wind pressure is developped. The result reveals： when elevation angle is small, background responsive values of mirror＇s different parts are approximately the same as the multi-phased resonant response occurring at the bottom; as the angle θ increases, airflow sepa- rates at the near side and reunite at the other, as forms vortex which enhances dynamic response at the upper part. The paper also analyses some representative phases on their nodes＇ displacements＇ response spectrums, compiling heliostat＇s surface wind pressure wind vibration factors under different phases, as provides groundings for structure design.

关 键 词： 风载荷 动力反应 时域分析 风振系数 定日镜

领　　域： [建筑科学] [建筑科学]