燃气轮机总体与空气系统耦合计算方法研究与匹配分析

发布时间：2018-04-05 13:47

本文选题：燃气轮机　切入点：空气系统　出处：《南京航空航天大学》2016年硕士论文

【摘要】：随着燃气轮机技术的发展,涡轮前温度的上升与涡轮叶片耐高温材料的限制导致了空气系统引气量的提高,空气系统对燃气轮机的总体性能的影响越来越大,因此,对燃气轮机总体与空气系统耦合计算方法研究具有重要价值。本文结合前人研究成果以及工程气动热力理论,对燃气轮机总体性能仿真方法与空气系统可压缩流体网络建模方法分别进行了研究,并在此基础上对考虑空气系统影响的燃气轮机总体性能进行了匹配分析。基于热力学原理对燃气轮机热力计算方法进行了研究,确定了变比热计算工质物性参数、等温焓差法确定燃烧室油气比的方法。通过这些方法,建立了燃气轮机各部件包括进气道、压气机、燃烧室、涡轮、喷管的热力性能计算模型,完成了燃气轮机从进口到出口各个截面气动热力参数的计算链。在燃气轮机共同工作条件的基础上,确定了Newton-Raphson迭代求解的匹配计算思路,其中对于转子部件特性曲线的处理,采用非对齐数据二元插值法提取压气机涡轮性能的方法。同时针对航空发动机空气系统中高速气体流动计算,采用流体网络法进行节点分支网络建模。其中采用了广义一维流动理论,通过比拟变换和龙格—库塔数值积分方法求解微分方程,得到简单分支结构(渐变截面换热管流动)流动参数的求解方法;采用经验损失系数方法求解复杂分支结构(截面突变、弯管、带网格截面、三通管)的进出口流动参数关系,最终形成一套适用于空气系统以及类似的气路管网计算建模方法。根据上述研究的热力计算建模方法,在考虑空气系统从高低压气机引气冷却涡轮叶片对燃气轮机总体性能的影响的基础上,开发了燃气轮机总体和空气系统耦合计算工具。针对某型地面航改燃气轮机,计算并分析了不同工作环境、不同油门角度、不同动力涡轮导向器安装角下燃气轮机总体性能变化规律。并且,特别针对空气系统影响,在控制尾喷管面积以及动力涡轮转速的情况下,得到如下结论:保持油门角度不变,随着引气量的提高,涡轮前温度随之提高,总功率相应的提高了,耗油率先增加后降低;保持油门角度可调,使引气量随着涡轮前温度增大相应增大,则输出功率提高,耗油率先降低后提高,存在最佳耗油率。
[Abstract]:With the development of gas turbine technology, the increase of turbine front temperature and the limitation of high temperature resistant material of turbine blade lead to the increase of air entrainment, and the influence of air system on the overall performance of gas turbine is more and more great.It is of great value to study the coupling calculation method between gas turbine and air system.In this paper, combined with previous research results and engineering aerodynamics theory, the simulation method of gas turbine's overall performance and the modeling method of compressible fluid network for air system are studied respectively.On this basis, the overall performance of gas turbine considering the influence of air system is analyzed.Based on the thermodynamic principle, the thermodynamic calculation method of gas turbine is studied, and the calculation parameters of working fluid properties with variable specific heat and the method of determining the oil / gas ratio of combustion chamber by isothermal enthalpy difference method are determined.Through these methods, the thermodynamic performance calculation model of gas turbine components including inlet, compressor, combustion chamber, turbine and nozzle is established, and the calculation chain of aerodynamic thermodynamic parameters of each section of gas turbine from inlet to outlet is completed.On the basis of the common working conditions of gas turbines, the matching calculation idea of Newton-Raphson iterative solution is determined, in which the non-aligned data binary interpolation method is used to extract compressor turbine performance for the processing of rotor component characteristic curves.At the same time, the node branch network is modeled by using fluid network method to calculate the high speed gas flow in the aero-engine air system.The generalized one-dimensional flow theory is used to solve the differential equations by analogy transformation and Runge-Kutta numerical integral method.The empirical loss coefficient method is used to solve the inlet and outlet flow parameter relations of complex branch structures (section mutation, curved pipe, gridding section, three-way pipe). Finally, a set of modeling method for air system and similar gas pipeline network is developed.On the basis of the thermodynamic calculation modeling method mentioned above and considering the effect of the turbine blade on the overall performance of the gas turbine, a coupling calculation tool between the gas turbine and the air system is developed.The general performance of gas turbine under different working environment, different throttle angle and different installation angle of power turbine guide is calculated and analyzed for a certain type of ground aeronautical modified gas turbine.Especially for the influence of air system, under the condition of controlling the area of nozzle and the speed of power turbine, the conclusion is as follows: keeping the angle of throttle constant, the temperature of turbine front increases with the increase of entrainment.With the increase of the total power, the oil consumption increases first and then decreases, and the angle of throttle is adjustable, so that the gas intake increases with the increase of turbine temperature, the output power increases and the oil consumption decreases first and then increases, and there is the best fuel consumption rate.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TK472

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