组合非球面太阳能聚光镜的光学设计

Optical design of build-up aspherical solar concentrating mirror

提出了一种组合非球面反射型太阳能聚光镜并给出了设计方法。聚光镜由38片非球面组成,每一片非球面都由一组特定系数C,a2,a4,a6,a8,a10的偶次非球面方程决定,是此特定非球面的一部分。根据非球面方程和光反射定律矢量形式,导出了非球面内壁上太阳反射光束的方向矢量与非球面系数C,a2,a4,a6,a8,a10的关系,适当地选择这些非球面系数,即适当地调整非球面面型,可以使太阳反射光束具有特定的方向矢量,使入射到非球面内壁上的太阳光束反射后全部聚焦在某一特定的区域内,形成小的光斑。每组特定系数都用粒子群优化算法求得,并经计算机模拟和实验证明其聚焦效果。聚光镜的光束压缩比为330∶1,其聚焦光斑可作为一种高温热源,而此聚光镜可以用在太阳能加热装置中。

In this paper , a build-up aspherical solar concentrating mirror and its design method are presented . It is composed of 38 pieces of revolution surfaces , and each piece of revolution surface is the part of the as-pheric surface defined by a set of specific coefficients C,a2 ,a4 ,a6 ,a8 ,a10 .According to the even aspherical e-quation and the law of reflection in vector form , the relationship between the direction vectors of rays of light reflected from the inner wall of aspheric surface and the coefficients of an aspherical equation , C,a2 ,a4 ,a6 , a8 ,a10 , has been derived .By appropriately choosing these aspherical coefficients , namely, appropriately ad-justing an aspherical surface type , the reflected light beam can have specific direction vectors , which can make the sunbeams incident on an aspherical inner wall focus on a particular area and form a small spot .Each group of specific coefficients is obtained by using particle swarm optimization algorithm .The focusing effect of the solar concentrating mirror with the specific coefficients is demonstrated by using computer simulations and proved experimentally .The theoretical compression ratio for this concentrating mirror is 330∶1 .The focused spot can be used as a high temperature heat source and the concentrating mirror can be used in a solar heating device .