干气密封气膜-密封环系统轴向振动动力稳定性分析  

Nonlinear stability analysis on axial vibration of dry gas seals system with gas film and seal rings

作　　者：俞树荣[1] 朱丽[1] 丁雪兴[1] 韩明君[2] 张伟政[1] 

机构地区：[1]兰州理工大学石油化工学院,兰州730050 [2]兰州理工大学理学院,兰州730050

出　　处：《振动与冲击》2012年第15期101-104,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金(50965010);高等学校博士学科点专项科研基金(20096201110001)

摘　　要：基于非线性振动理论,建立了气膜-密封环系统轴向振动动力学模型,在特例下计算并拟合非线性气膜轴向刚度与阻尼,得到了一个含二次、三次项的非线性受迫振动微分方程。在无外激励情况下,通过求Floquet指数讨论了系统分岔问题,分析了螺旋角对系统稳定性的影响,给出了使干气密封系统稳定的螺旋角的范围,并求得在特例下螺旋角α=75°13'26″时系统发生Hopf分岔。这与先前利用龙格-库塔法研究的结果一致,从而验证了该方法的正确性。改变工况讨论系统分岔问题,得到了系统分岔时的螺旋角数值,结果表明其螺旋角数值基本不变,说明改变工况其分岔点位置不变,其结果为干气密封的动态优化设计提供理论指导。Based on the nonlinear vibration theory,the axial vibration model of the film and seal rings in the system of dry gas seals was established.A forced vibration differential equation containing the second and the third order nonlinear terms was derived in consideration of the nonlinear axial rigidity of the gas film.The bifurcation behavior of the system was discussed according to Floquet exponent,and the stability influenced by spiral angle was analyzed.The range of the spiral angle that makes system stable was given under the condition of none outer excitation.At the spiral angle of 75°13′26″,the Hopf bifurcation would occur.The result is identical with that obtained by using Runge-Kutta method and the validity of the method was verified.The bifurcation behavior of the system was discussed under different working conditions and the spiral angle corresponding to bifurcation was determined.The results show that under different working conditions,the value of spiral angle is basically unchanged,that means the position of bifurcation point will remain unchanged.The results provide theoretical guidance to the dynamic optimization design of dry gas seal.

关 键 词：干气密封 非线性 轴向刚度 稳定性 分岔 

分 类 号：TB42[一般工业技术]