槽式聚光镜组系统的抗风性能研究

In recent years, parabolic trough condenser mirror systems are the prime solar collecting system in international, and already have a large-scale application in the field of solar collector and power generation. But, in China, it is still in the initial stage of research. The solar thermal power projects that will construct in our country are generally located in the northwest and coastal where are windy areas. With lower rigidity and larger windward area, the solar concentrating group is easy to have wind-induced deformation, which makes the specular reflection offset and causes energy efficiency losses, and strong wind can also destroy the condenser mirrors. Therefore, it is necessary to take further investigations of the wind-resistance problems of parabolic trough condenser mirrors..The project will adopt a combination of wind tunnel test, theoretical analysis and full-scale measurement to research the wind-resistance problems of parabolic trough condenser mirrors systems. On the basis of getting the rules and characteristics of wind load distribution, the shape coefficient of each wind direction, and conditions and laws of the wind-induced response of the critical parts in the mirror systems, proposing the methods to determine equivalent wind load and calculate wind-induced response, developing a series studies with the mirror systems of mirror deformation calculation and control measures, reliability of structural wind resistance, and structure type and constructed optimization of the mirror group, in order to provide the parabolic trough mirror groups for basic wind-resistant design parameters and practical design and calculation methods, and afford adequate theoretical basis and technical support for the wind-resistant design of parabolic trough mirror systems.

槽式聚光镜组系统是近年来国际上最主流的太阳能聚光系统，在太阳能集热与发电方面已有较大规模的应用，但在我国尚处于研究的起步阶段。我国将建设的太阳能热发电项目都分布在西北及沿海等多风地区，槽式聚光镜组系统的迎风面积大、易出现风致变形，使得镜面对太阳光的反射出现偏移而造成能效损失，而且强风也会造成镜组的破坏。因此，有必要对其抗风问题进行深入的研究。.本项目将采用风洞试验、理论分析和原型实测相结合的方法，研究槽式聚光镜组系统抗风问题。在获得其风荷载分布规律和特点、各风向角的体型系数和镜组系统重点部位风致响应的状况和规律的基础上，提出等效风荷载的确定方法与风致响应的计算方法，开展镜组系统镜面变形计算与控制措施、镜组系统结构抗风可靠度和镜组结构型式和构造的优化等一系列研究，为槽式聚光镜组的抗风设计提供基本的设计参数和实用的设计及计算方法，为我国槽式聚光系统的抗风设计提供充分的理论依据和技术支撑。

本项目采用风洞试验、理论分析、数值模拟及现场实测等技术手段对槽式聚光镜系统的抗风性能进行了系统的分析研究，获得了槽式聚光镜在不同工况下的风压分布规律和特征、聚光镜周围流场特性、镜面不同区域的脉动风压特性、极值风压系数、聚光镜整体风力系数、动力特性、风致响应以及等效风荷载的计算方法等，并对镜组工况下槽式聚光镜之间的干扰效应进行了分析研究，然后将风洞试验与数值模拟结果、现场实测与数值模拟结果进行了对比分析，验证数据的准确性，并总结出相关规律和特征。在此基础上对镜组聚光性能、镜面变形以及长期可靠性开展了研究，提出了聚光焦斑轮廓尺寸和位置变化的控制方法、结构型式和构造的优化设计建议，为我国槽式聚光系统的抗风设计提供充分的理论依据和技术支撑。