Design And Performance Research Of The Unfiorm Concentrating Fresnel Lens

Solar energy, which reserves infinite, is clean pollution-free, safe and reliableenergy. It will be the most ideal energy source in the future. Concentrated Photovoltaicpower generation technology with a high conversion efficiency and cost reduction space,become a new bright spot in the solar energy applications. The concentrator is one ofthe core components in the Concentrated Photovoltaic systems, Fresnel concentrator(Fresnel lens) has been widely used in the Concentrated Photovoltaic systems becauseof the significant advantages such as high optical quality, small volume, light-weight aswell as mass production with low cost.However, the uniformity of irradiance distribution at the focal plane is very poorfor the traditional Fresnel lens, which resulted in the decrease of the cell conversionefficiency and the battery life, it limits the further development of ConcentratedPhotovoltaic systems. As a result, the research on modified design methods of Fresnellens, which to improve the uniformity, is very important.Based on the geometrical optics principles, combined with the traditional Fresnellens design methods, derived the formula for calculating the parameters of the planarFresnel lens, the influencing factors of the Fresnel lens optical efficiency is analyzed,calculated the transmittance of the Fresnel lens designed by different focal length. UsingSolidWorks3D modeling software and Tracepro optical simulation software, analyzedthe irradiance distribution on the focal plane of traditional Fresnel lens, focusing on thenon-uniformity of the irradiance distribution, based on the light intensity superpositionprinciple, proposed three improved design of Fresnel lens, constructed series of lensmodel with different parameters, studied irradiance distribution of these lenses by raytracing, comparatively analyzed the performance of different design options, selectedone design with the good performance for the in-depth study.To confirm the practical applicability, the design is improved, and as a final designof the uniform concentrating Fresnel lens. Based on the design, constructed a series ofmodel by changing the focal length and geometric concentrating ratio of the uniformconcentrating Fresnel lens, researched the variation regularity of the structureparameters and the performance.