Research On Structure Selection And Mechanical Property Of Heliostat Supporting Structure Of Dual-axis Tracking CSP System

Along with the situation of the dwindling traditional energy resources as well as the increasing environmental pollutions, people now have strong demand on new types of energy, which, to some extent, greatly stimulates the development of the research on photo-thermal power system. The dual-axis tracking CSP system, based on the improved dual-axis instant tracking equipment to realize real-time tracking with the sun, is a new type of photo-thermal power system. It enables the sunlight to parallel with the central axis of the heliostat at any time, thus greatly improving the efficiency in both utilization of solar energy and generation of electricity power. To achieve instant tracking of the sun, this system encompasses large bulks of movable supporting tower and sliding supporting frame to support the whole procedure, which evidences that it is the reasonable and economical supporting tower and frame that play a crucial role in no matter workability of the new system or expansion of marketing. Currently, the research on this type of supporting system has barely started both at home and abroad. This paper makes a research on the structure design and mechanical properties of the dual-axis tracking CSP system, and includes the following parts:Firstly, this paper presents the current applications of the photo-thermal power system, specifies the classification of this system and the ongoing research and application of its supporting system. As to the dual-axis tracking CSP system, this paper systematically clarifies its working mechanism and the characteristics together with working requirements of its supporting system. On this basis, this paper clarifies the requirements and key points in designing the supporting system, and also makes a meticulous analysis of structure selection of the movable frame combined with the established theories on the design of the movable structures.Secondly, considering the characteristics of the structural shape, this paper sets up the computational areas, and makes a division of the inner and outer areas of each computational area. Using different type of grids in different areas, the calculation afford has been dramatically reduced while the accuracy of computation has been upgraded into a new level. Meanwhile, in order to ensure the distribution property over the surface of the heliostat, as well as the shape parameter of the heliostat under different wind angles, the essay makes a CFD simulation of the mean wind in the heliostat area with the application of the CFD theory and the realizable k-e turbulence model.Thirdly, in the way that the theory in random vibration and appropriate research methodology in wind-induced vibration goes, this paper makes...It makes a modal analysis of the supporting structure of the heliostat, establishes the vibration characteristics of the structure, analyses the power spectrum of the supporting structure of the heliostat by using Davenport wind velocity spectrum. Through making a comparison...it clarifies the extent of influence of the wind-induced dynamic force upon the supporting structure, and establishes the overall wind-induced vibration coefficient.Lastly, what is worth mentioning is that--according to the requirements of engineering design, this paper not only combines with the key design factors of the supporting structures of the dual-axis tracking CSP system as well as the research on the mechanical properties of the movable frame, but also puts forward the structural plan of the object project, introduces the selection and design of the supporting structure of the heliostat.