菲涅尔透镜热变形对CPV聚光系统性能影响的数值研究

由硅胶-玻璃材料组成的SOG(silicone on glass)型菲涅尔透镜在温度变化时会产生热变形，影响CPV(concentrating photovoltaic)聚光系统的性能。为研究透镜热变形对聚光系统光效率的影响，优化设计两类聚光系统，并采用数值计算的方法模拟透镜的热变形，再将热变形导入光学模型中，使用蒙特卡罗方法计算变形前后的聚光效率。结果表明:对于单级聚光系统，采用单色光均匀性优化方法设计的透镜受翘曲变形和齿面自由变形影响较大，光效率在变形前后相差10%左右，改进型补偿色散方法设计的菲涅尔透镜受翘曲变形和齿面自由变形影响较小。另外，双级聚光系统可以有效抵抗热变形的影响。

Numerical investigation on impact of thermal deformation of Fresnel lens on CPV system performance

The thermal deformation of silicone on glass (SOG) Fresnel lens made up of silicone and glass can affect the performance of concentrating photovoltaic (CPV) system. In order to investigate the influence, we designed and optimized two kinds of CPV concentrator systems. Then, we calculated the thermal deformation of Fresnel lens with finite element analysis method, as well as the concentration efficiency of the system through Monte Carlo method. The calculation indicates for the single stage concentrator system, the Fresnel lens designed with monochromatic light uniformity method is obviously affected by the warpage deformation of concentrator and free deformation of prisms. The difference of optical efficiency is about 10% between the deformed and the undeformed concentrator system. However, the Fresnel lens designed with improved method that compensates for dispersion is little influenced by thermal deformation. Moreover, the two stage concentrator system can be greatly resisted to the thermal deformation.