汽轮机组基于弹性基础下轴系稳定性的评估

Evaluation of Shafting Stability of Steam Turbine Based on Elastic Foundation

采用弹性基础的汽轮机组,其基础静刚度及动刚度相较于刚性基础均有所下降,易产生轴承标高变化和轴系失稳的风险。因此,基于弹性基础下轴系稳定性的研究对于保障机组运行的安全性和稳定性具有十分重要的意义。在轴系稳定性核算中准确考虑基础刚度的耦合作用是必要的,研究中将不同频率下的基础刚度和对应的轴承支撑刚度与油膜刚度进行耦合,形成整个支撑系统的动刚度,进而更加真实地计算机组轴系稳定性结果。

Compared with the rigid foundation,the basic static stiffness and dynamic stiffness of the steam turbine unit with elastic foundation are reduced,which is easy to cause the risk of bearing elevation change and shaft system instability.Therefore,the research on the shafting stability based on the elastic foundation is of great significance to ensure the safety and stability of the unit operation.It is necessary to accurately consider the coupling effect of the foundation stiffness in the shafting stability calculation.In this study,the foundation stiffness at different frequencies and the corresponding bearing support stiffness and oil film stiffness are coupled to form the dynamic stiffness of the entire support system,and furthermore real computer group shafting stability results.