不同瞄准策略的线性菲涅耳式聚光器光学性能  

Optical performance of linear Fresnel condenser under different aiming strategies

作　　者：王成龙[1] 闫伯龙 徐茂 马军[1] Wang Chenglong;Yan Bolong;Xu Mao;Ma Jun(National Engineering Research Center for Technology and Equipment of Environmental Deposition,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学国家绿色镀膜技术与装备工程技术研究中心,甘肃兰州730070

出　　处：《红外与激光工程》2023年第9期183-191,共9页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(52066010);甘肃省重点研发计划项目(20YF8GA039)。

摘　　要：吸热管表面能流密度分布的均匀性对线性菲涅耳式聚光器的光热性能及安全运行有着重要影响。基于Tonatiuh光学仿真软件构建了线性菲涅耳式聚光器模型,研究了圆柱面形反射镜焦距及瞄准点位置与光斑宽度之间的关系,在此基础上探讨了不同瞄准策略下线性菲涅耳式聚光器的光学效率及能流分布的均匀性。结果表明:采用瞄准点均匀分布的瞄准策略,聚光器在保持较高光学效率的同时能够提升集热管表面能流分布的均匀性。采用优化后的瞄准策略,线性菲涅耳式聚光器光学效率可达到87.4%,集热管表面能流密度标准差由45.3%降低到30.7%,集热管顶部能流密度提升了10.2%。集热管空管预热采用该优化瞄准策略,在变占空比跟踪模式下,集热管弯曲变形程度远小于现有瞄准策略。该结果可为线性菲涅耳式聚光集热系统的优化设计提供理论支撑。Objective The linear Fresnel solar concentrator is one of the technologies of concentrator solar thermal power generation(CSP).Because the primary mirror are discrete flat mirrors and installed near the ground,the system has the advantages of strong wind resistance,which is especially suitable for large-scale construction in the northwest region of China with excellent solar energy resources but high wind speed.The existing research results show that the solar irradiation on the surface of the collector tube is very uneven in linear Fresnel concentrator system due to the different aiming strategies and the reflection profile of the secondary mirror.In addition,the medium in the tube is difficult to quickly divert the heat from the surface of the collector tube,the collector tube is easy to bend and deform,resulting in the breaking of the outer glass tube of the vacuum tube and the increasing heat loss of the system.The uniformity of heat flux density distribution on the absorber tube surface has a significant impact on the optical and thermal performance,as well as safe operation of linear Fresnel concentrating solar systems.Therefore,it is necessary to study the method for improving the uniform distribution of energy flux density to improve system efficiency and system security.Methods A linear Fresnel concentrator model was built using Tonatiuh optical simulation software,a cylindrical reflector was selected as the research object,and the relationship between the focal length(radius of the reflector)and the position of the aiming point on the aiming plane and the width of the spot was studied.Based on the fact that the width of the spot is not greater than the width of the secondary mirror opening,the focal length of the mirror and the distance from the center of the aiming point are determined.According to the different distribution of aiming points,five different aiming strategies are proposed,and the specific data are shown(Tab.2).Based on this,the optical efficiency and uniformity of heat flux distribution

关 键 词：聚光太阳能热发电 线性菲涅耳式聚光器 瞄准策略 能流分布 光学效率 

分 类 号：TK519[动力工程及工程热物理—热能工程]