【作者】 张艳梅；

【导师】 骆仲泱； 方梦祥； 岑可法；

【作者基本信息】 浙江大学 ， 热能工程， 2013， 博士

【摘要】 太阳辐射能具有能流密度低、不稳定和光谱分布范围宽等特点,因此聚光技术、蓄热技术和分频技术分别是太阳能研究者研究的关键性问题之一。针对上述问题,本文以太阳能碟式热发电系统的研究为背景,对太阳能二次反射下聚光-热发电系统光路的优化设计及新型聚光-分频系统的光路设计展开了相关的数值模拟和实验研究。本文的研究工作主要包括：①对五种二次反射系统进行理论推导、数值模拟和比较；②建立旋转双曲面上半支型二次反射系统的三维光学模型并编程,讨论各种误差对系统聚光效果的情况；③搭建太阳能二次反射下聚光试验台,建立聚光镜镜面测量系统和光斑测量系统,开展镜面扫描、光路验证和光斑测量等实验并分析；④设计一种新型分频器,建立二次反射聚光-分频系统的光学模型并编程,讨论各种误差对系统聚光效果的影响；⑤对太阳能二次反射下聚光系统和二次反射聚光-分频系统进行系统分析和比较。在数值模拟方面,运用ASAP软件,分别对平面型、旋转椭圆面型、旋转双曲面上半支型、旋转双曲面下半支型和旋转抛物面型等五种二次反射系统建立几何模型、进行数学推导并模拟,讨论一次镜边缘角、二次镜数值孔径、焦点相对位置等几何参数对二次镜相对位置、二次镜直径、遮光率、光斑直径、能量聚光比等的影响。在此基础上,得出适合本实验室研究思路的二次反射系统类型为旋转双曲面上半支型。对该系统建立三维光学模型,根据蒙特卡洛法编写光路追踪程序以研究聚光光斑的能流密度分布,讨论太阳形状、跟踪误差、安装误差等因素对系统聚光比、光斑直径、光斑偏移的影响。在实验方面,搭建了一米的和三米的碟式二次反射系统,通过镜面测量系统得到二次反射系统的镜面模型,结合程序对实际镜面模型进行分析；对一米碟式二次反射系统的光路验证结果与模拟结果吻合良好,证实了镜面测量系统的正确性。搭建了光斑测量系统,分别对一米和三米的二次反射系统的聚光情况进行了实验测量和误差分析,一米系统的聚光效果理想,三米系统的聚光镜面需要改进。本文还设计了一种新型的分频器,可以将分频后的两束光斑均反射至一次镜下方。对该新型二次反射聚光-分频系统的光路进行了推导,建立三维数学模型并编写模拟程序,讨论太阳形状、跟踪误差、安装误差等因素对系统聚光比、光斑直径、光斑偏移的影响。最后,对可蓄热的碟式二次反射下聚光斯特林发电系统和分别以Ⅱ-3B聚光光伏电池和外燃式热机为光伏和光热利用元件的聚光-分频电热联用系统建立分析模型,计算结果表明,碟式二次反射下聚光系统效率为21.3%;对电热联用系统。当ηther<21%或ηther>30%时,根据需要可考虑采用分频系统,系统效率最高为25.9%；当21%<ηther<30%时,应独立发电为主。本文的工作为研究太阳能二次反射技术及新型的聚光分频技术提供了理论基础。更多还原

【Abstract】 There are three main challenges in solar energy utilization, for example lower energy density, changing with season, broad range solar spectrum and so on. Solar concentrating technology, thermal storage technology and beam splitting technology are some of the key technologies in solar power plant. Based on this, this thesis focuses on the development of solar dish systems. Experimental research and numerical simulation are carried out on the two-stage beam down system and the novel beam splitting system.The researches carried out in this paper include:①discuss and compare the performances and applications of five types of secondary mirrors.②analyze the3-D optical model of a beam-down system which employs the upper sheet of a hyperboloid as a secondary mirror.③establish the experimental set up, the mirror scanning system and the flux density distribution measuring system; carry out the experiments indoor and outdoor.④design a novel beam splitter and analyze the3-D optical model.⑤analyze the performances of the two designed systems.In terms of numerical simulation, five types of two-stage reflection systems were analyzed and compared by ASAP software, of which the secondary mirror could be a planar, an ellipsoidal, a upper sheet of a hyperboloidal, a lower sheet of a hyperboloidal, or a paraboloidal type, respectively. The effect of the rim angle, numerical aperture of the secondary mirror and the relative position of the focus on the secondary mirror size, shading percentage, spot size and flu concentrator ratio are discussed. The system which employs an upper sheet of a hyperboloid as secondary mirror is discussed. A3-D optical model based on Monte Carlo method is established. The effect of the sun shape, the tracking errors and the alignment errors on the concentration ratio, the spot size and deviation are discussed.In terms of experiments, two experimental set ups are established. The shapes of both systems are scanned and compared with the design surfaces. The optical experiments are carried out indoor to verify the mirror scanning system. The flux density distribution measuring system is established and experiments are carried out outdoor. The experimental results show that the1000mm system has a good performance while the3000mm system needs to be improved. A novel beam splitter is designed and the3-D optical model is analyzed. The3D optical model of a beam splitting system is also established based on Monte Carlo method. The effect of the sun shape, the tracking error and the alignment error of the second mirror on the concentration ratio, the spot size and deviation are discussed.Finally, a two-stage beam down dish-Stirling power system with thermal storage and a hybrid system combining photovoltaic cells with a Stirling engine are analyzed. The comparison of the two systems is carried out based on the system analysis model we set up. The calculated efficiency of the two-stage beam down system is about21.3%. For the beam splitting system, the calculated efficiency is about25.9%when ηther<21%or ηther>30%, and it is not wise to employ the beam-splitting technology when21%<ηther<30%.The research in this thesis provides a theoretical basis for the research of two-stage beam down technology and beam splitting technology.更多还原