【作者】 奚忠；

【导师】 刘建军； 付经伦；

【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， 2012， 硕士

【摘要】 径流式透平作为一类小型热功转换装置,在很多方面得到了应用,例如以其作为关键部件的微小型燃气轮机,广泛用于小型分布式发电、冷热电联供、车辆混合动力以及军用车辆的辅助电站等。本文对微小型燃气轮机径流透平的方案设计、三维造型与优化方法进行了详细研究。具体工作和主要结论如下(1)在分析各种因素对径流透平速比和反动度限制的基础上,提出了一种比较合理的速比和反动度的选择方法,并用C语言编写了径流透平一维热力设计计算程序(OCC),通过与已发表文献中的一维热力计算程序(OFC)结果进行比较,发现两者结果基本一致,且OCC设计总对总效率要高于OFC的设计效率；用一维热力设计程序对600kW燃气轮机径流透平导叶和动叶进行了设计,并进行了三维计算,对比发现一维程序计算结果与三维CFD数值模拟结果两者基本一致,验证了本文的设计方法以及一维热力设计程序对于微小型径流透平的方案设计是适用的；(2)采用二维分析方法,研究了进气蜗壳设计方法,编写了蜗壳设计计算程序。根据程序计算得到的蜗壳截面的几何参数,可在UG中实现蜗壳的三维造型；(3)对600kW整级径流透平进行数值模拟,整级透平包括蜗壳、导叶以及动叶,分析整个透平级的整体性能以及流动特征。整级透平数值模拟结果表明,导叶内的流动相当好,优化的空间不大,叶轮整体上设计比较成功,但仍需要进一步的优化；(4)研究了径流透平气动优化设计方法,建立了气动优化设计平台,优化平台包括基于NURBS曲线的参数化造型,CFD数值模拟以及先进的优化算法。针对600kW径流透平的叶轮进行了气动优化设计,使透平总总效率提高了0.12个百分点,透平流动性能得到了进一步改善。更多还原

【Abstract】 Radial turbine, as a small heat-work conversion unit, is widely used in different fields. Radial turbine, for example, is the key component of small gas turbines and the application areas of such gas turbines include distributed power generation, combined heat and power supply, subsidiary power generation of military vehicle and so on. This dissertation investigates the radial turbine one-dimensional aero-thermal preliminary design,3D modeling and the aerodynamic optimization method. The main contents and results are as follows:1) A reasonable method of choosing speed ratio and degree of reaction for the small radial turbines was described. A one-dimensional aero-thermal preliminary design code OCC was programmed by analyzing all kinds of restriction factors on the speed ratio and degree of reaction. The design results for a600kW radial turbine nozzle and rotor blade by using the code OCC were compared with the results by the code OFC in the literature. The main parameters between the two designs were in agreement and the total to total isentropic efficiency of the radial turbine designed by the OCC is larger than that by the OFC. The three-dimensional flow calculation is conducted for the design by the OCC. The comparisons between the CFD results and the OCC results for the radial turbine showed that the results were in agreement. The present design method and the one-dimensional design code OCC are appropriate to the preliminary design of small radial turbines.2) The design method based on the two-dimensional analysis of the radial turbine inlet volute was discussed and the design code was programmed. The geometric parameters of the volute cross sections can be obtained by using the method and the design code. The3D volute is modeled with UG according to the volute design results.3) The3D flow fields of the whole radial turbine including the inlet volute, all the passages of nozzle and rotor blade are calculated. The flow inside the turbine and the overall performances were analyzed. The results indicate that the design of the stator is rather successful and the impeller still needs to be improved.4) An aerodynamic optimization platform for radial turbines is developed, which consists of the modules of geometry parameterization by means of NURBS, CFD flow simulation and advanced optimization algorithm. The optimization of the rotor blade of the600kW radial turbine was carried out and the turbine total to total efficiency increased by0.12%.更多还原