Research On Image Analysis And Correction System Of Heliostat Spot Quality

Heliostat is the most important component in the tower solar thermal power generation system.In the process of concentrating power generation,the concentrating efficiency of heliostat is very important,which directly affects the collecting efficiency of heat receiver,and then affects the power generation efficiency of the whole power generation system.The optical quality and tracking accuracy of heliostat are the key indicators to improve the concentrating efficiency of heliostat,so how to evaluate and improve these two indicators is of great significance in the whole power generation system.The shape error of the fixed day mirror affects the optical quality of the heliostat,and the tracking error of the heliostat affects the tracking accuracy of the heliostat.The two factors can be reflected by the spot spot of the heliostat:the shape of the spot reflects the shape error of the heliostat mirror;The position of spot reflects the tracking error of heliostat.Therefore,this paper designs a system based on the spot spot evaluation and correction of heliostat,evaluates the optical quality and tracking accuracy of the heliostat and corrects the tracking error of the heliostat.The specific research work of this paper is as follows:(1)The static optical quality test scheme of heliostat spot is proposed.In order to evaluate the optical quality of heliostat,the measured spot shape of heliostat is fitted by image processing,and the parameters are obtained and compared with the theoretical simulation results.(2)The test scheme for dynamic tracking accuracy of heliostat is proposed.The centroid position of a group of spot with equal time interval is analyzed by means of probability and statistics,and the horizontal and vertical tracking deviation angles are calculated to evaluate the dynamic tracking accuracy of heliostat.(3)The correction scheme of heliostat tracking error is proposed to improve the dynamic tracking accuracy of heliostat.According to the dynamic geometric tracking error source of heliostat,the dynamic geometric tracking error model of heliostat is established,and the calculation formula of tracking angle containing the dynamic geometric tracking error of heliostat is derived.The least square mathematical model of unknown tracking error in the calculation formula of tracking angle is established and solved,and the accurate calculation formula of error angle is obtained,so as to correct the tracking error.The test scheme of static spot quality and dynamic tracking accuracy of heliostat proposed in this paper is simple,accurate and efficient,and has a certain practical value in the tower solar thermal power generation system.The correction scheme of heliostat tracking error can effectively correct the tracking error of heliostat.Through the verification of experimental simulation and real measurement data,this correction scheme meets the tracking accuracy of the system,can be applied to the actual site,and can greatly improve the concentrating power generation efficiency of the tower solar thermal power generation system.