Research On Wind Load On Structural Design Of Parabolic Trough Collector In Solar Thermal Power Plants

In order to vigorously develop and promote the solar energy,we need to solve the cost issue,and make it similar or have less cost in investment than other power-generating approaches.By constantly researching in recent years,the power-generating technology’s cost of solar energy and other renewable energy is falling but there is also bigger space in developing.Considering the interference of the parabolic trough array to the wind load can clarify the wind load distribution of the solar field.Under the premise of ensuring the stability of the structure in the wind field,reducing the amount of material is used to reduce the cost of construction and installation.However,there are few studies on the wind load of parabolic trough array in the world,and the researching object is mostly Euro trough.At present,the aperture of the parabolic trough is gradually increasing,so the wind loads of the new parabolic trough needs to be reassessed.In this paper,begin with wind tunnel tests,a large-aperture parabolic trough is the researching object on the wind pressure distribution of the single mirror,the interference effect of the trough array,and the wind-induced response of parabolic trough array.The following tasks have been completed:（1）Solitary parabolic trough collector wind tunnel test.The wind pressure distribution data of a solitary trough under different pitch angles and wind directions are measured through wind tunnel tests.According to the contour map of the mirror wind pressure coefficient,the influence of the pitch angles and the wind direction on the mirror wind pressure distribution is analyzed.The force coefficient of the trough is calculated and the change of wind load on the large-aperture parabolic trough during the working process is discussed.The mirror wind pressure distribution and force coefficient of different aperture trough is compared,and the influence of aperture size on the mirror wind load is analyzed.（2）Parabolic trough collector array wind tunnel test.The simulative trough array arrangement has 6 rows,including 108 rigid models.By changing the position of the pressure measurement model in the array,the wind load characteristics and mutual interference effects at different positions of the multi-row trough is studied.According to the distribution of wind pressure on the mirror surface and the wind coefficient of the trough,the differences of wind load on the array is analyzed along the horizontal and vertical directions of the array.The effect of mutual shielding of wind loads and narrow channel wind are discussed.A solar field can be classified into four areas,each area has the similar wind coefficient,and the wind load interference coefficient of each area is provided for reference.（3）Time history response analysis of parabolic trough collector.Numerical model of a solitary trough and Solar Collector Assembly（SCA）is established and a modal analysis is conducted,the influence of structural frequencies at different pitch angles is discussed.According to the results of the array wind tunnel test,the parabolic trough of typical location is selected to analyze the wind-induced responses.By using the Newmark method to calculate with ANSYS software,the displacement response of the parabolic trough under typical working conditions is obtained,the fluctuating wind-induced response ratio of the through at different positions is compared,its translational displacement wind-induced vibration coefficient and torsional displacement wind-induced vibration coefficient is calculated.According to the displacement wind vibration coefficient of the edge nodes of the cantilever arm,the solar field is divided into two areas.A case study of the SCA in different areas,uses the formula provided by Load Code for the Design of Building Structures and the parameters from this study to calculate equivalent static wind load and to do equivalent static analysis for the use of each parameter providing reference.