线性菲涅尔式聚光系统单管接收器的设计与优化

Design and analysis of a CPC with single vacuum tube for linear Fresnel reflector system

接收器是决定线性菲涅尔式聚光集热系统光学效率的关键部件之一.设计了一种适用于高温介质(>500°C)的线性菲涅尔式聚光系统的接收器,由单根真空集热管和CPC组成,并重点研究了CPC最大接受半角和截取比选择对其性能的影响.研究结果表明:CPC汇聚率随最大接受半角的增大而缓慢增大;若截取比小于0.65,则CPC汇聚率急剧下降;最大接受半角为45°、截取比为0.75的CPC开口宽度为475.49 mm,汇聚率为80.15%;基于该CPC的系统光热效率为58.06%,由此得出CPC实际汇聚率高于78.42%.

Compound parabolic collector （CPC） plays an important role in optical efficiency of linear Fresnel reflector （LFR） system. In this paper, we designed and optimized a CPC for LFR system. The main element influence on optical performance of CPC was studied, and the maximum acceptance angle and the truncation ratio of CPC were principally reported. Simulation results of the relationship between maximum acceptance angle and convergence ratio show that CPC convergence ratio increased slowly and linearly with the increase of maximum acceptance angle. Experimental results of the relationship between truncation ratio and convergence ratio show that CPC convergence ratio increased sharply until truncation ratio is greater than 0.65. CPC convergence ratio basically achieves a certain value when truncation ratio is greater than 0.7. Ray tracing simulation study illustrated that CPC, with 45° maximum acceptance angle, 0.75 truncation ratio and 475.49 mm opening width, could achieve a high concentrate ratio about 80.1%. Meanwhile, this conclusion was further verified by the experimental measurement results.