Research on the Flutter Instability Vibration of Tilting Pad Journal Bearing Considering Fluid-structure Interaction

doi:10.3901/JME.2020.09.118

Abstract

Abstract: Taking a tilting pad journal bearing of a test-bed as the research object, a dynamic model considering the coupling motion between pad and journal is established. The tilting pad response is solved by Newmark-β method. The waveform and frequency spectrum of pad swing angle and displacement during start up process are obtained. Results show that flutter caused by swing angle and displacement of pad will occur on certain conditions. The flutter amplitude increases as the rotation speed is increased. Frequency locking phenomenon occurs after a certain speed. The flutter instability can be controlled by increasing pad preload. The theoretical calculation results are consistent with the experiment results. Through the unstable vibration fault analysis of a 660 MW turbogenerator unit, it is found that flutter caused the breakage of the spring on the back of the pad. The broken spring aggravates the flutter of the pad and causes the large vibration. It results in the damage of babbit on oil inlet edge, eccentric abrasion of pins and pin holes. The problem can be solved by increasing pad preload and replacing the broken spring.

Key words: tilting pad journal bearing, fluid-structure interaction, flutter instability, preload

CLC Number:

TG156

LAI Yongneng, LI Qingfeng, QIU Jianhai, YANG Jiangang. Research on the Flutter Instability Vibration of Tilting Pad Journal Bearing Considering Fluid-structure Interaction[J]. Journal of Mechanical Engineering, 2020, 56(9): 118-124.

References

[1] 王丽萍,乔广,郑铁生,等. 可倾瓦轴承的完整动力分析模型及计算方法[J]. 机械工程学报, 2008, 44(1):75-80. WANG Liping, QIAO Guang, ZHENG Tiesheng, et al. Analysis and calculate model for the complete dynamical coefficients of tilting-pad bearings[J]. Chinese Journal of Mechanical Engineering, 2008, 44(1):75-80.
[2] 张永芳,肖良君,李贤伟,等. 固定瓦-可倾瓦动压气体轴承-转子系统的非线性运动分析[J]. 机械工程学报, 2018, 54(11):188-196. ZHANG Yongfang, XIAO Liangjun, LI Xianwei, et al. Analysis of nonlinear motion of a rotor system supported by fixed-tilting pad self-acting aerodynamic bearings[J]. Journal of Mechanical Engineering, 2018, 54(11):188-196.
[3] 赵卫正,陈海鑫,周仁米,等. 9FA燃气轮机可倾瓦油膜涡动故障分析与处理[J]. 燃气轮机技术, 2017, 30(4):63-65. ZHAO Weizheng,CHEN Haixin,ZHOU Renmi,et al. Oil whirl analysis and treatment of a tilting pad for 9F gas turbine[J]. Gas Turbine Technology, 2017, 30(4):63-65.
[4] 郭玉杰,刘静宇,石峰. 某型机组低压转子油膜涡动的分析与处理[J]. 汽轮机技术, 2015, 57(2):142-144. Guo Yujie, LIU Jingyu, SHI Feng, et al. The analysis and dispose of oil film whirl on a certain low-pressure rotor[J]. Turbine Technology, 2015, 57(2):142-144.
[5] 赵卫正,童小忠,王小荣,等. 西门子9F燃机轴系异常振动分析与处理[J]. 燃气轮机技术, 2018, 31(3):53-58. ZHAO Weizheng, TONG Xiaozhong, WANG Xiaorong, et al. Analysis and treatment of abnormal vibration of a siemens 9F gas turbine generator unit[J]. Gas Turbine Technology, 2018, 31(3):53-58.
[6] 陈阳, 杨建刚. 汽轮发电机组滑动轴承油膜振荡故障的分析与治理[J]. 轴承, 2012, 10(9):25-28. CHEN Yang, YANG Jiangang. Analysis and treatment of oil whip fault of sliding bearings in turbo-generator unit[J]. Bearing, 2012, 10(3):25-28.
[7] 孙永明,吴士年,李海鹏,等. 离心压缩机可倾瓦轴承油膜失稳解析[J]. 风机技术, 2012, 73(6):73-90. SUN Yongming, WU Shinian, LI Haipeng, et al. Analysis of tilting-pad bearing oil-film unstability in centrifugal compressor[J]. Chinese Journal of Turbomachinery, 2012, 73(6):73-90.
[8] SEUNG Y, YUN S, JUN I Y, et al. Dynamic characteristics of composite tilting pad journal bearing for turbinegenerator applications[J]. Composite Structures, 2018, 107(2017):94-105.
[9] 马辉,李辉,张素燕,等. 转子系统二阶油膜失稳故障仿真及试验研究[J]. 机械工程学报, 2013, 49(9):24-29. MA Hui, LI Hui, ZHANG Suyan, et al. Simulation and experiment research on the second order oil-film instability fault in a rotor system[J]. Journal of Mechanical Engineering, 2013, 49(9):24-29.
[10] 刘玉智. 青岛电厂300 MW机组异常振动的诊断与处理[J]. 振动工程学报, 2004, 17(S):366-368. LIU Yuzhi. Abnormal vibration diagnosis and treatment of unit 300 MW in Qindao power plant[J]. Journal of Vibration Engineering, 2004, 17(S):366-368.
[11] 杨建刚. 旋转机械振动分析与工程应用[M]. 北京:中国电力出版社, 2007. YANG Jiangang. Rotating machinery vibration analysis and engineering application[M]. Beijing:China Electric Power Press, 2007.
[12] PAOLO P, ANDREA V, STEVEN C, et al. Case history of pad fluttering in a tilting-pad journal bearing[C]//Glasgow:Proceedings of ASME Turbo Expo 2010:Power for Land, Sea, and Air. 2010:227-233.
[13] 王大成,史庆峰,王苗苗,等. 汽轮机可倾瓦轴承低频振动诊断与处理[J]. 核动力工程, 2016, 37(S1):38-42. WANG Dacheng, SHI Qingfeng, WANG Miaomiao, et al. Diagnosis and treatment of low-frequency vibration of steam turbine tilting bearing[J]. Nuclear Power Engineering, 2016, 37(S1):38-42.
[14] YANG S, KIM C, LEE W. Prevention of flittering fatigue damage in a tilting pad journal bearing[J]. Tribology International, 2009, 42(6):816-822.
[15] 朱爱斌,杨玉磊,陈谓,等. 四瓦可倾瓦轴承瓦块摆动特性[J]. 机械工程学报, 2014, 50(9):33-47. ZHU Aibin, YANG Yulei, CHEN Wei, et al. Swing characteristic of pads in four-pad tilting pad bearing[J]. Journal of Mechanical Engineering, 2014, 50(9):33-47.
[16] 王永亮,刘占生,钱大帅. 可倾瓦轴承瓦块摆动特性[J]. 哈尔滨工业大学学报, 2011, 43(9):62-66. WANG Yongliang, LIU Zhansheng, QIAN Dashuai. Swing characteristic of pads in tilting pad bearing[J]. Journal of Harbin Institute of Technology, 2011, 43(9):62-66.
[17] YANG S H, KIM C, LEE Y B. Experimental study on the characteristics of pad fluttering in a tilting pad journal bearing[J]. Tribology International, 2006, 39(7):686-694.
[18] HARGREAVES D J, FILLON M. Analysis of tilting pad journal bearing to avoid pad fluttering[J]. Tribology International, 2007, 40(4):607-612.