Research On Bending Deformation Measurement Of Trough Collectors For Solar Thermal Power Generation

The collector tube,as one of the key components of the concentrating system of the trough solar thermal power plant,is used to receive the converged solar radiation energy.The bending deformation of the collector tube makes it deviate from the focal line position of the concentrating system,causing part of the light not to be received by it,which directly affects the interception efficiency of the concentrating system,and then affects the efficiency of electricity generation plant.Therefore,it is important to study the bending deformation detection technology of trough collector.In this paper,we aim to find a fast,accurate and non-contact bending deformation detection method for collector tubes and develop related detection equipment,so as to provide detection technology and equipment support for bending deformation measurement of collector tubes in trough solar thermal power plants.The main research contents of this thesis are as follows:1.The existing measurement technology with trough collector tube as the detection object is analyzed,and the bending deformation detection method of collector tube based on UAV photogrammetry is proposed.The camera on board the UAV takes images of the collector tube from mutually perpendicular directions,and based on digital image edge detection technology,obtains the edge position of the collector tube,then calculates the actual centerline position of the collector tube,then connects the two ends of the actual centerline position to get the ideal centerline position,and finally makes the difference between the actual centerline and the ideal centerline of the collector tube to obtain the bending deformation of the collector tube.2.The calculation method of the effect of collector bending deformation on the intercept efficiency is proposed.Based on Monte Carlo ray tracing theory,the trough concentrating system is modeled,the influence of solar spot size and the surface shape error of the concentrating mirror is considered,the collector is quantified,and calculate the normalized area where the spot reflecting the main light from different positions of the collector intersects with the cross section of the collector,so as to obtain the calculation formula of the influence of the bending deformation of the collector on the intercept efficiency.3.Based on the UAV photogrammetry method,a testing device for measuring the bending deformation of collector tubes is developed.The system design of the testing equipment and the hardware implementation of each part are introduced in detail,and the determination methods of camera shooting direction and UAV shooting distance are analyzed.4.Using MATLAB programming software,a trough collector bending deformation measurement software was developed.The software has a graphical user interface,simple operation,and can automatically display and save the test results.5.The measurement error of the collector bending deformation testing equipment is analyzed,and relevant experiments are conducted.The experimental results show that the measurement error of the equipment is about 0.62 mm,and the repeatability accuracy of0.35 mm,which verifies the correctness and feasibility of the testing equipment.