核电汽轮机长叶片与轴振动耦合特性研究

Vibration Coupling between Long Blades and Shaft in Nuclear Steam Turbines

针对核电汽轮机组转子系统中长叶片与轴的振动耦合问题,建立考虑叶片柔性、转速等因素影响的叶片-轴系统动力学模型。采用CN群论,对系统特征值进行降阶。对模型进行数值求解发现,系统中存在多阶叶片与轴的耦合模态及较明显的级间耦合模态,且引入转速后系统固有频率有提高的趋势。分析结果表明,叶片柔性及转速对叶片-轴系统模态特性有重要影响。该研究可为汽轮机转子系统的设计及稳定运行提供指导和参考。

For the coupling vibration between long blades and shaft in rotor system of steam turbines of nuclear power, the dynamic model of the blade - shaft system is formulated with blade flexibility and rotation speed included, and the order of system eigenvalues is reduced by CN group theory. It is found in solving the model numerically that multi - stage coupled modal of blades and shafts, and more obvious inter - stage coupling modals exist in the system, and the natural frequency of system becomes higher while rotating. The analysis results show that the both blade flexibility and rotation speed are significantly influencing the modal properties of the blade - shaft system ; the research provides guidance and reference for design and stable operation of rotor of steam turbines.