【作者】 张雪辉；

【导师】 陈海生；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 动力机械及工程， 2014， 博士

【摘要】 电力储能系统在电力系统中作用日益显著,压缩空气储能技术是目前能大规模商业运营的两种电力储能技术之一,但传统压缩空气储能技术依赖化石能源,能量密度低,为克服传统压缩空气储能系统的缺点,学者们提出了超临界压缩空气储能系统,多级向心透平是超临界压缩空气储能系统关键部件之一,其性能直接影响储能系统效率,因此,为研发高效稳定的多级向心透平,提高储能系统效率,非常有必要对多级向心透平进行全面细致研究。本文对超临界压缩空气储能系统多级向心透平系统进行总体热力学分析,通过自编程序对多级向心透平进行设计研究,完成四级向心透平设计,再对向心透平内部流场和变工况特性进行研究,搭建超临界压缩空气储能系统四级向心透平实验平台,并对其进行实验研究,主要研究内容如下：1.详细研究了多级向心透平系统的热力过程,分析系统能量分布和(?)分布,研究分别以热效率、(?)效率和系统出功为优化目标下多级向心透平系统性能,确定不同热源温度下多级向心透平的优化目标函数,并对MW级超临界压缩空气储能系统中的多级向心透平进行总体设计。2.开展四级向心透平设计研究,以实验数据为基础,确定了以载荷系数、流量系数、比转速和速比为多目标优化的设计程序,发展一套将一维设计、叶片造型和三维优化校核有机结合的向心透平设计程序,并完成四级向心透平的设计工作,确定第一、二级向心透平叶轮为闭式叶轮,第三、四级向心透平叶轮为半开式叶轮。3.利用CFD技术对向心透平进行三维流场研究,分析导叶和叶轮流道内马赫数、压力和熵的变化特性,并对导叶出口参数进行分析,其与设计值基本吻合,导叶损失区集中在喉道和叶片表面,叶轮损失区集中在叶顶截面和尾迹区。对向心透平变工况特性研究表明,向心透平的转速和膨胀在较大范围内变化时都能保持较高的效率。4.搭建了首个MW级超临界压缩空气储能系统四级向心透平实验台,包括四级向心透平实验件、齿轮传动系统、能量耗散系统、压力调节系统和温度控制系统等,该实验台满足高转速、高膨胀比多级向心透平的实验要求。对四级向心透平进行实验研究,分析系统启动特性和总体性能,其启动时间在5min内；进口压力7.0MPa时,实验各级透平的等熵效率分别为80.0%、87.9%、82.2%和89.1%,总效率为84.4%。更多还原

【Abstract】 Electrical Energy Storage(EES) technologies are increasingly important in the power system. The Compressed Air Energy Storage(CAES) technology is one of two types of commercially available ESS technologies in large scale. However, the traditional CAES has the drawbacks of dependence on fossil fuels and low energy density. A supercritical CAES system is developed by researchers to conquer these problems. The multistage radial turbine is one of the key components of supercritical CAES, whose performance directly affects the efficiency of energy storage system. It is of imperative to make full and detailed investigate on developing the highly efficient and stable multistage radial turbine in order to improve the efficiency of whole energy storage system.In this thesis, the multistage radial turbine system of the supercritical CAES was thermodynamically analyzed. The four-stage radial turbine was designed and studied through an in-house coding and the turbine unit design results were obtained. Then it was studied through Computational Fluid Dynamics(CFD) to reveal its internal flow field and performance under various working conditions. The four-stage radial turbine rig of the supercritical CAES was built to conduct the experimental research.The main contents of the thesis were as follows:1. The performance and design criteria of air powered multistage turbine were studied thermodynamically. It was simulated the energy and exergy distributions. And the characteristics of multistage turbine with inter-heating were optimized in terms of maximum thermal efficiency, maximum exergy efficiency and maximum workoutput over different inlet temperatures. The systematic parameters of multistage radial turbine were developed for MW-level supercritical CAES system.2. The design method was investigated in detail, by which the four-stage radial turbine was designed. The impellers of the first and second stage radial turbines were closed impellers, and the third and fourth stage radial turbines were semi-open impellers. The design method consisted of one-dimensional design method, blade design method and three-dimensional optimization. The one-dimensional design method was based on the experimental data and simultaneously optimized such parameters as load factor, flow coefficient, specific speed and velocity ratio.3. The aerodynamic characteristics of radial turbine under design and off-design conditions were investigated in detail through the CFD technology. It was investigated the guide vane row and rotor row passages’Mach number, pressure and entropy distributions. The outlet parameters of the guide vane was agreed well with the designed results. The losses of the guide vane row mainly occurred in the throat and blade surface. The losses of the rotor row mainly occurred in the impeller tip and wake regions. The study of the radial turbine indicated that it could achieved a relatively high efficiency under a relatively large range of rotation speed and expansion ratio.4. The four-stage radial turbine experimental rig for MW-level supercritical CAES system was established including radial turbines, gear transmission system, load management system, pressure control system and temperature control system. This rig could fulfill experimental requirements of multistage radial turbine system with highspeed and high expansion ratio. The experiments were carried out to study its start-up characteristics and overall performance. It was concluded that:its start-up time was within5minutes; under7.0MPa inlet pressure the efficiencies from the first stage radial turbine to the fourth stage radial turbine were80.0%,87.9%,82.2%and89.1%, respectively; the total efficiency of the four-stage radial turbine system was84.4%.更多还原