【作者】 王富强；

【导师】 谈和平； 帅永；

【作者基本信息】 哈尔滨工业大学 ， 工程热物理， 2012， 博士

【摘要】 太阳能热动力发电具有不使用化石燃料、零污染物排放等优点，是清洁的发电系统。由于地球表面接收到的太阳辐射强度除了受到昼夜、季节和地理纬度等规律性因素的影响外，还受到阴云和雨雪天气等随机性因素的制约，以及集热子系统热流密度传输不均匀性的影响，因而太阳能的热利用具有显著的间断性和不均匀性，导致吸热器受到反复高温差的热冲击循环而承受高热应力并引起吸热器的弯曲变形及失效。本文以太阳能高温热转换及利用为应用背景，结合实际应用过程中对太阳能高效低成本利用技术的发展需求，对太阳能热动力发电站中的太阳光线聚集与传输、能量的吸收与转换以及吸热器的可靠性等关键核心技术的科学基础问题展开研究。主要研究内容包括以下四个方面。1．采用直接热流密度场实验测量系统对搭建在哈尔滨工业大学的双轴跟踪多碟聚光系统焦平面处热流密度场进行测量；并编制了基于蒙特卡洛法的求解太阳能辐射聚集传输问题的计算源代码，将实验测量得到的多碟聚光系统焦平面处无量纲热流密度场与数值模拟结果进行对比研究，找出数值模拟的最佳参数组合；研究了多碟聚光系统的反射镜数目及镜面反射率的变化对焦平面处的热流密度场分布的影响。2．在分析半球形腔体式太阳能吸热器聚集辐射分布特性的基础上，结合太阳能光学窗口的折射而重新分配聚集辐射热流的作用，本文提出了含有上凸式光学窗口的腔体式太阳能吸热器，分析了等效误差、光学窗口特征参数及壁面吸收率对含有上凸式光学窗口半球形腔体式太阳能吸热器壁面热流密度场分布的影响；并对含有上凸式光学窗口的腔体式太阳能吸热器的热效率特性进行了研究；从吸热器光学效率的角度对平顶锥形腔体式太阳能吸热器展开研究，分析了吸热器开口半径和单碟聚光系统的相对光孔对平顶锥形腔体式太阳能吸热器的辐射传输特性的影响。3．为了解决平顶锥形腔体式太阳能吸热器底面处金属管盘绕过程中无法布满整个底面而降低吸热器光学效率的问题，本文提出了两种新型底面凸起腔体式太阳能吸热器以达到提高吸热器光学效率的目的；并分析了底面凸起无量纲高度、壁面吸收率、指向误差和焦面位置误差等参数对底面凸起腔体式太阳能吸热器光学效率提高的影响。4．采用蒙特卡洛法与有限单元法相结合的计算方法对管式太阳能吸热器进行了温度场、热应力场及应变场的研究，并将蒙特卡洛法与有限单元法相结合的计算结果与简化热流密度场边界条件下的计算结果进行对比研究。鉴于墨西哥国立大学太阳能热利用电站采用铜管式太阳能吸热器替代不锈钢管式太阳能吸热器来解决在实验和运行中发生的吸热器弯曲变形问题，本文研究了不同材料对管式太阳能吸热器的热应力场及应变场的影响。为了降低管式太阳能吸热器的热应力和总应变，本文提出了一种偏心管式太阳能吸热器，并研究了偏心角及偏心率对偏心管式太阳能吸热器的热应力场及应变场的影响。更多还原

【Abstract】 Solar dynamic power generation system is a clean power generation system with manyadvantages, such as: without using fossil fuel and zero pollutant emission, etc. The solarradiation intensity received by the earth is affected no only by diurnal variation, season,latitude and other regular factors, but also by clouds, rain, snow and other random factors, aswell as by heterogeneous heat flux transmission of the collector subsystem. Therefore, the solarthermal utilization has severe intermittence and heterogeneity, which can cause the receiver toendure repeated high–temperature differential thermal shock cycles and subjected to highthermal stress till bending deformation and receiver failure.Based on the background of high–temperature conversion and utilization of solar energyas well as the requirement of applied technology development of high effective and low costsolar energy utilization, this dissertation will research on the concentration and transmission ofsolar rays, absorption and conversion of energy, reliability of receiver and other key scientifictechnologies of solar dynamic power generation system. The main researches of thisdissertation include the following four aspects.1．Heat flux distribution on the focal plane of the biaxial tracking multi–dishesconcentrator system set up in Harbin Institute of Technology is measured by direct heat fluxdistribution measurement system. A program for solving concentration and transmissionproblem of solar radiation is compiled based on the Monte Carlo method. In order to seek theoptimal parameter combination for numerical calculation, the dimensionless heat fluxdistribution calculated by numerical method is compared with that measured by direct heatflux distribution measurement system. Besides, the variations of dimensionless heat fluxdistribution on the focal plane of multi–dishes concentrator system with the increase of dishesand change of reflectivity are also studied in this dissertation.2．Based on the directional characteristic analysis of concentrated heat flux distributionon the focal plane of hemispherical cavity receiver and the redistribution effect of opticalwindow, a cavity receiver with internal convex optical window is proposed. The effects ofeffective error variation, characteristic parameters variation and absorptivity variation ofreceiver surface on the heat flux distribution of the hemispherical cavity receiver with internalconvex optical window are analyzed. Besides, the thermal efficiency of cavity receiver withinternal convex optical window is also investigated. The researches on conical cavity receiver are carried out from the perspective of optical efficiency of receiver, and the irradiativetransfer properties variation of conical receiver with the change of aperture radius and relativeaperture is analyzed.3．In order to solve the problem that the bottom surface of conical cavity receiver can notbe completely covered with coiled metal tube and to improve the optical efficiency, two newtypes of cavity receiver with bottom surface convex are put forward in this dissertation. Theeffects of dimensionless bottom surface convex height variation, absorptivity variation ofreceiver surface, pointing error variation and alignment error variation on the optical efficiencyof cavity receiver with bottom surface convex are analyzed.4．The researches on the temperature field, thermal stress field and strain field of tubereceiver are carried out by adopting Monte Carlo and Finite Element combined method, andthe results calculated by Monte Carlo and Finite Element combined method are compared withthe results calculated with simplified heat flux distribution boundary condition. In view ofsolving the deformation problem of stainless steel tube receiver occurred during applicationand experiment in the National University of Mexico solar dynamic power station by usingcopper tube receiver, the effects of material selection on the thermal stress field and strain fieldare investigated. The eccentric tube receiver is put forward in this dissertation to decrease thethermal stress and total strain of tube receiver, and the effects of oriented angle and eccentricityvariation on the thermal stress field and strain field of eccentric tube receiver are alsoinvestigated.更多还原