非连续转子连接界面力-热耦合滑移机理及引起的振动研究

Gas turbine is the sign of the science and technology level of a country, there is a large difference of the level of gas turbine technology between our country and developed countries, especially on the aspects of the reliability and the life. Generally, the rotor of gas turbine is a typical discontinuous structure with all disc-drum structures assembled by great size flanges. The interfaces of this complex rotor are prone to slip under the combined actions of low frequency thermal shock and high frequency mechanical excitation. The slippage of interface results in the deformation of gas turbine rotor and causes the increase of rotor vibration, which affects the reliability and the life of gas turbine. This proposal proceeds from the non-uniform distribution of contact pressure on the interface of the gas turbine discontinuous rotor, based on the interaction of the contact pressure and the thermal contact resistance on the interface of this discontinuous structure, will propose a mechanical-thermal coupled modeling method for the discontinuous structure by combining the mechanical model and thermal conductance model, and to analyze the slip status of interface. The macro slip mechanism of interface in discontinuous structure will be investigated. The deformation of rotor due to the slip of interface will be studied, and the influence on the vibration of rotor will be researched. This proposal will form a mechanical-thermal coupled modeling method for the discontinuous rotor, and the slip mechanism of the interface in the discontinuous rotor under the combined actions of mechanical and thermal loads will be investigated. This research has the theoretical and practical significances to solve the vibration problem of the discontinuous rotor resulted from the interface slip, and to improve the reliability and the life of gas turbine.

燃气轮机是一个国家科技水平的标志，我国燃气轮机技术水平与发达国家还有较大差距，尤其是在可靠性和寿命方面。燃气轮机转子通常是由盘毂结构通过大直径法兰连接组成，是典型的非连续结构，该复杂转子在低频热冲击激励和高频机械激励共同作用下容易发生连接界面滑移现象，引起转子变形，导致转子振动加大，影响燃气轮机的可靠性和寿命。本项目基于燃气轮机非连续转子连接界面接触压力的非均布特点，从非连续结构界面接触压力与接触热阻的相互作用入手，提出综合结构力学模型、热传导模型的非连续结构力-热耦合建模方法，研究在力、热高低周载荷作用下非连续转子连接界面的滑移状态，探究连接界面整体滑移的形成机制，分析界面滑移引起的转子变形特性，研究界面滑移对转子振动的影响规律。本项目将形成非连续转子力-热耦合建模方法，研究连接界面的滑移机理，对解决非连续转子界面滑移引起的振动问题，提高燃气轮机的可靠性和寿命具有理论和实际意义。

燃气轮机转子通常是由盘毂结构通过大直径法兰连接组成的非连续结构。在燃气轮机运行过程中形成的低频热冲击激励和高频机械激励共同作用下，非连续转子容易发生连接界面滑移现象，引起转子的弯曲变形，导致转子振动加剧，严重影响燃气轮机的可靠性和寿命。本项目首先通过研究给出了典型螺栓连接结构界面接触压力分布特性，结合接触热阻的经验公式分析了螺栓连接界面接触热阻分布规律，进而通过连接界面接触压力和接触热阻的关系，建立了典型螺栓连接结构的力-热耦合模型，仿真分析了不同温度边界下典型螺栓连接结构的变形特性，掌握了典型螺栓连接结构力热耦合下界面滑移机理。在此基础上，建立了典型燃气轮机非连续转子结构力热耦合动力学模型，研究了不同温度边界下转子连接界面的滑移状态，分析了转子的热变形特性，给出了热变形转子的振动特性。设计和搭建了模拟非连续转子力热耦合动力学试验台，开展了不同温度边界下模化非连续转子的热变形特性和振动特性，验证了理论模型。本项目阐述了非连续转子连接界面在力热耦合作用下滑移机理，给出了热变形转子的振动特性，并通过试验验证，为燃气轮机非连续转子力热耦合动力学优化设计及运行维护提供了参考，研究方法为降低燃气轮机复杂热环境下转子振动水平提供了技术支撑，可以提高燃气轮机整机的可靠性和寿命。