重型燃气轮机转子系统在热-流-固多场耦合作用下的非线性振动分析

The rotor system of the heavy duty gas turbine has several structural features, such as the heavy quality, the longer length, etc. The working conditions of the gas turbine rotor system is developed to the direction of the higher temperature, higher pressure and higher speed, has many different characteristics from the general high-speed rotary machine, the multi-field coupled effects which influence on gas turbine vibration become more and more serious. The complex phenomena of gas turbine rotor system under the severe service conditions can’t be explained by the conventional dynamics theory, so the research of the complex high-dimensional nonlinear dynamics theory under the multi-field coupled action of the gas turbine machine has become very urgent. This project will integrate the national and worldwide latest development of dynamics, hybrid modeling and nonlinear theory，and also will combine with the finite element method (FEM) and boundary element method(BEM), to deal with the dynamic modeling under the action of the thermal-fluid-solid multi-field coupled condition. Combining with the multidisciplinary field cross, the dynamic multi-field coupled model of the rotor system of the heavy duty gas turbine will be set up including the thermal field, fluid field and stress field. In a further study, a calculation and simulation under the typical working condition will be done based on the previous work, using the test data which from the actual working monitoring in the gas turbine power plant and Lab test, to determine the boundary conditions under the multi-field coupling, and the nonlinear vibration analysis will be in-depth researched. In the current project, a new progress will be made in the modeling of the gas turbine rotor system, the theory support for the study of gas turbine rotor system under multi field coupling dynamic can be provided. And we will acquire the theory and technique of vibration transmission as well as the character of vibration transmission under typical working conditions. The research achievement can be applied to the specific design and fault diagnosis of the equipment.

重型燃气轮机转子系统具有质量厚重，长度偏长等结构特点，且其工作条件不断向更高温、更高压、更高速的方向发展，多场耦合作用对重型燃机振动的影响越来越强烈。常规动力学理论无法解释严酷服役环境下重型燃机转子系统所表现出的复杂现象，急需突破多场耦合作用下的高维非线性动力学理论。本项目结合国内外转子动力学、混合建模与非线性理论的最新发展，采用有限元和边界元相结合的方法，突破在热-流-固多场耦合作用下的动力学建模问题。利用多学科交叉，建立起重型燃机转子系统在温度场、流场和应力场等多场耦合作用下的非线性动力学模型。在此基础上进行典型工况的计算仿真，运用燃机电厂实际工况监测数据及试验相结合的方法，实现多场耦合作用下边界条件的确定，从而进行深入的非线性振动分析，掌握其振动机理，获得典型工况下机组的振动特征，为研究重型燃机转子系统在多场耦合下的振动分析提供理论支撑，研究成果可应用于该类设备的具体设计和故障诊断。

重型燃气轮机转子系统具有复杂的结构形式，是在高温、高压、高流速等复杂多变工况下高速旋转机械。本项目采用混合建模技术，研究了不同耦合工况下重型燃气轮机转子系统的非线性振动特性，建立了对应的非线性动力学方程；研究了电厂多物理场多点参数的数据提取方法，建立了其转子的多场耦合模型，结合电厂9F级重型燃气轮机转子系统典型工况的振动数据对该模型和分析结果进行验证和修改，确定了系统的仿真软件方案，并进行数值仿真分析，研究了由外部耦合激励引起的复杂转子非线性动力学特性、在碰摩、非线性气流、热冲击及温度场不稳定、结构应力等多场因素引起的转子系统非线性振动特性。. 项目通过总结分析，不断完善试验方案的设计与论证，优化了现有转子模拟试验台的设计提出改善转子系统振动的方案，通过对多工况的仿真结果与测试结果进行对比研究，验证了燃机转子模型和仿真路线的合理性，从而揭示了重型燃气轮机转子系统在热-流-固多场耦合作用下的非线性振动机理，为研究重型燃机转子系统在多场耦合下的振动 分析提供理论支撑，研究成果可应用于该类设备的具体设计和故障诊断。