Design and Performance Analysis of Toroidal Heliostat in Solar Tower Power Plant
太阳能塔式电站轮胎面定日镜的设计及性能分析

For improving the concentrating performance of the heliostat in the solar tower thermal power generation technology,the toroidal heliostat for correcting off-astigmatism was investigated.The four heliostats were chosen which locate at four characteristic positions of a concentrator field.The distances between the receiver and the observed heliostats and the annual change ranges of sunlight incident angle onto the heliostats were calculated.According to the calculated values of distance and angle the focal length and the field of view of the designed heliostats can be determined.The toroidal heliostats for these four positions were designed with the software ZEMAX.The optical performance of the toroidal heliostat was analyzed.Compared with the spherical heliostat,there are considerable improvements:not only the size of focal spot is reduced,but also it is possible to shift the minimum focal spot from the edge to the center of the field of view.The manufacture method for the toroidal heliostat was proposed and the feasibility was demonstrated by the experience.