环面焦斑全内反射菲涅尔透镜设计及分析

Design and Analysis of Ring-Shaped-Focus and Double Total Internal Reflection Lens Fresnel Concentrator

为了减小由热斑效应带来的损失,增加太阳能转换效率,克服二次镜带来的菲涅尔损失,以及由大口径和几何聚光比带来的焦斑不均匀的问题,设计了环面焦斑全内反射菲涅尔透镜.环面焦斑全内反射菲涅尔透镜由两部分组成,里面是环面焦斑太阳能透镜,外面是二次全反射棱镜.用Tracepro模拟和比较具有相同通光面积的普通菲涅尔透镜和环面焦斑全内反射菲涅尔透镜的光照度,结果表明,环面焦斑全内反射菲涅尔透镜具有较高的光能利用率和均匀性.

In order to reduce the damage caused by the heat effect,increase the solar conversion efficiency and overcome the Fresnel losses brought by the secondary mirror,a novel hybrid Fresnel concentrator without using secondary optical element is presented which also overcomes the non-uniform illumination distribution brought by large diameter and geometric concentrating ratio. The desingned Fresnel lens consists of two parts： the inner part and the outer the former being the ring-shaped-focus Fresnel lens,while the outer part is double total internal reflection lens（ DTIR）. Taking a common Fresnel and a Ring-Shaped-Focus Fresnel with the same light area as an example,a conclusion can be drawn that the Ring-Shaped-Focus Fresnel has higher light utilization and illumination uniformity by Tracepro software.