【作者】 李铁；

【导师】 唐大伟；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 工程热物理， 2011， 博士

【摘要】 碟式聚光太阳能热发电技术近30年在国际上取得了长足的发展。碟式热发电系统由于具有光电转换效率高,使用灵活等优点,在可再生能源及分布式供能技术受到日益重视的今天,正引起越来越多的关注。太阳能斯特林发动机作为碟式热发电系统的核心动力设备,其优良程度直接决定整个系统的发电性能。本文首先简要叙述了斯特林发动机及其碟式热发电系统中的关键技术,然后对近年来国内外在碟式热发电技术领域取得的重要技术进展进行综述,并浅析了碟式热发电技术在中国的发展前景。本文的主要工作是对碟式太阳能热发电系统用斯特林发动机进行自主研制。首先从现有的斯特林发动机分析与设计方法着手研究,分析其各自的优点及局限性；然后引入一些斯特林发动机机型的实验测试数据,对经典的施密特分析法进行修正,发展出一套能够较为准确的预测斯特林发动机实际运转时热力性能的设计方法；另外,从质量、动量、能量守恒方程组出发,结合一系列动力学相关方程,并考虑到负载的启动特性,建立了一套分析斯特林机内部工质流动换热及热功转换过程的方法。该方法充分考虑到斯特林发动机从启动前预热过程到启动瞬时过程再到稳定运转过程的各个阶段中机器的工作特点。对斯特林发动机在实际工作过程中产生的主要损失因素进行了简要的定性分析。运用经过作者改进的施密特分析法,设计出一台千瓦级β型单缸斯特林发动机。该机的机械传动部分设计为菱形传动机构。建立了一套测试该机动力性能的实验平台并进行了实验。实验中使用一台汽油发动机在空载运行时排放的中高温废气作为热源驱动该斯特林机,用测功机测得该机的输出轴功率及扭矩随转速变化的特性关系。实验中该斯特林机的输出功率达到了3476W,对应的转速为1248RPM。实验中还研究了该斯特林机换热器系统中工质压力的变化特性,发现采集到的三个位置处工质的压力值呈同一正弦规律的周期性变化,这与采用施密特分析法计算得出的压力结果具有一致性；且三处压力变化曲线之间的相位差几乎为0。通过对压力的实验数据研究还发现,回热器两侧的压差是冷却器两端压差的两倍多；该结果也表明,采用叠网式多孔结构的回热器是造成斯特林机换热器系统内工质压力损失的主要原因。对碟式热发电系统中太阳能斯特林发动机用的集热器进行了研制。在充分分析碟式抛物面聚光镜的几何特性及存在的太阳能集热器接口问题后,设计出两款直接照射式的太阳能集热器。其中一款为采用U形夹层通道对工质进行加热的腔式集热器,数值仿真结果显示,它在工作过程中能够具有较均匀的壁面温度场分布,从而能够避免较大热应力的产生；设计出的另一款集热器以渐开线形状的吸热器管为特征,能够在有限的空间里高效率的接收太阳能。对设计出的这两款太阳能集热器分别做了试制工作。在本文对斯特林发动机及其太阳能集热器研制工作的基础上,建立了一套3kW级的碟式太阳能热发电系统。该系统具有开口直径为5m的碟式聚光镜,其焦点位置安装有本文自主研制并完成改造的3kW级太阳能斯特林发动机。已经初步完成了该系统的搭建,待负载系统以及控制系统加装完成后,即可对整套系统进行试运行调试。更多还原

【Abstract】 The technology of dish solar power generation gets substantial progress internationally in the recent three decades. The dish solar power generation system is receiving more and more attention today due to its great importance attached to the renewable energy and distributed energy supply technology, and its advantages of high solar-electricity conversion efficiency and flexible application. The solar Stirling engine is the key power equipment in the dish solar power generation system, which directly determines the performance of the whole system.A brief introduction is made on the key technology of the Stirling engine and the dish solar power generation system at the beginning, and then the latest related international development in the technological fields is reviewed. The future development of the dish power generation technology in China is also briefly analyzed.The main work of this dissertation is to research and develop (R&D) a Stirling engine which can be used in the dish solar power generation system. The advantages and disadvantages of the existing design methods of Stirling engines are analyzed. Then the classic Schmidt analysis method is modified by using some experimental testing data of several internationally famous Stirling engines, and a design method that can precisely predict the performance of Stirling engines in operation is presented in this dissertation. In addition, a method for analyzing the fluid flow, the heat transfer and the energy conversion in the Stirling engine is provided by starting from the equation set of mass, momentum and energy conservation relations, by introducing a series of dynamic equations, and considering the characters of common loads like generators. The qualitative analysis on the main factors that cause the power loss of Stirling engines in real operation is also presented. A β-type single cylinder Stirling engine is developed by using the modified Schmidt analysis method. The rhombic mechanism is designed into the engine. An experimental system is built to test the performance of the developed Stirling engine, and a series of experimental tests are conducted. During the tests, waste gases with mid-high temperature exhausted from a gasoline engine at no-load running condition are used to drive the Stirling engine as the heat source. The output shaft power could reach3476W at the rotational speed of1248RPM.The pressure loss of the working fluid in the heat exchanger system of the Stirling engine is also studied. The recorded test data show that the loss between the inlet and outlet of the regenerator is more than twice that between the inlet and outlet of the cooler, so the porous metal regenerator is the major factor which causes the pressure loss of the working fluid. The pressure variation is approximately sinusoidally periodic, and the phase difference of the pressure values among the three different locations is almost zero.The solar receivers for the dish power system are also studied and designed. The problem at the interface between the sunlight collector and the solar receiver is studied firstly, and then two solar receivers are developed. One has the feature of U-shape channels to heat the internal working fluid, so the wall temperature could distribute more uniformly and avoid intense thermal stress according to the simulation results. The other one has the feature of involute heater tubes, which could receive more sunlight in a narrow space. The two solar receivers are both trial-produced.On the basis of the above work, a3kW dish solar power generation system is built. The system mainly includes a solar concentrator with its diameter of about5m and a solar Stirling engine with an indicated output power of about3kW near the focus point of the concentrator. This solar Stirling engine is reformed from the above-mentioned β-type Stirling engine.更多还原