摘要
基于非线性振动原理,建立转子-轴承-干气密封系统轴向振动动力学模型,定性分析螺旋角及螺旋槽槽深对系统稳定性的影响,并与仅考虑干气密封系统的分析结果进行比较。在特定工况下,计算并通过多次拟合得到非线性气膜轴向刚度和阻尼,将其代入到双自由振动方程,得到一个三阶的非线性双自由度受迫振动微分方程。运用Runge-Kutta对该方程进行求解,分析螺旋角对密封环振动位移的影响。结果表明:静环的振动位移随着螺旋角(76.5°～80.0°)的增加先减小后增加,当螺旋角为78.50°时,振动数值最小,其最大振幅为7μm,最大振速为25μm/s;在考虑转子和轴承影响的干气密封系统中,螺旋角对密封环振动的影响更加显著;改变螺旋角可以调节和减小密封环的振幅,而改变螺旋槽槽深对静环的振动幅值几乎没有影响。研究表明,通过适当增加螺旋角度(0.5°～0.6°),可以使密封环的振动位移最小,从而保证干气密封系统的稳定运行。
Based on the nonlinear vibration principle,the axial vibration dynamic model of the rotor-bearing-dry gas seal system was established.The influence of spiral angle and spiral groove depth on system stability was analyzed,and the results were compared with those obtained by only considering the dry gas seal system.In specific conditions,the axial nonlinear gas film stiffness and damping was calculated and fitted,by substituting it into the free vibration equation,a three order nonlinear double freedom forced vibration differential equation was obtained.The Runge-Kutta method was used to solve the equations,and the effect of the spiral angle on the vibration displacement of static ring was analyzed.The results show that the vibration displacement of the static ring is decreased first and then increased with the increasing of the spiral angle(from 76.5° to 80.0°),When the spiral angle id 78.50°,the vibration value is the smallest,the maximum amplitude is 7 μm,and the maximum vibration velocity is 25 μm/s.In the dry gas seal system considering the influence of rotor and bearing,the influence of spiral angle on the vibration of static ring is more significant.Changing the spiral angle can adjust and reduce the amplitude of the seal ring,while changing the spiral groove depth has little effect on the vibration amplitude of the static ring.The research shows that the vibration displacement of the seal ring can be minimized by properly increasing the helical angle (from 0.5° to 0.6°),thus ensuring the stable operation of the dry gas seal system.
作者
张伟政
薛建雄
李金晓
丁雪兴
ZHANG Weizheng;XUE Jianxiong;LI Jinxiao;DING Xuexing(College of Petrochemical Engineering,Lanzhou University of Technology,Lanzhou Gansu 730050,China)
出处
《润滑与密封》
CAS
CSCD
北大核心
2019年第5期9-16,共8页
Lubrication Engineering
基金
国家自然科学基金项目(51565029
51165020)
甘肃省自然科学基金项目(145RJZA083)
关键词
干气密封
非线性振动
轴向刚度
稳定性
dry gas seals
nonlinear vibration
axial stiffness
stability
