基于叶轮转子系统下的干气密封轴向振动分析

Analysis of Axial Vibration of Dry Gas Seal Based on Impeller Rotor System

为探究基于叶轮转子系统下干气密封轴向振动特性,基于干气密封结构特性,建立叶轮转子-轴承-干气密封系统轴向振动模型,采用待定系数法进行求解,推导得出静环轴向振动幅值表达式;建立叶轮转子-轴承-干气密封系统几何模型,运用ANSYS Workbench软件进行模拟仿真计算,分析气膜刚度和激振力对轴向振动的影响。结果表明:气膜刚度对动、静环振动幅值的影响不大;动、静环振动频率相同、振动幅值相同,说明动、静环的追随性高,其间隙稳定,从而保证干气密封的稳定运行;动、静环位振动幅值与激振力成正比关系,说明激振力严重影响干气密封的稳定性,为提高干气密封的稳定性,应平衡好叶轮的轴向激振力。

To explore the axial vibration characteristics of dry gas seals based on the impeller rotor system,based on the characteristics of the dry gas seal structure,the axial vibration model of the impeller rotor-bearing-dry gas seal system was established and solved by the undetermined coefficient method,and the expression of the axial vibration amplitude of the static ring was derived.The geometric model of impeller rotor-bearing-dry gas seal system was established,ANSYS Workbench software was used for simulation and calculation,and the influence of the gas film stiffness and exciting force on the axial vibration was analyzed.The results show that the gas film stiffness has little effect on the vibration amplitude of the dynamic and static rings,and the dynamic and static rings have the same vibration frequency and vibration amplitude,indicating that they have high following ability and stable gaps,so as to ensure the stable operation of the dry gas seal.The vibration amplitude of the dynamic and static rings is proportional to the exciting force,which indicates that the excitation force seriously affects the stability of dry gas seal.In order to improve the stability of dry gas seal,the axial exciting force of impeller should be balanced.