A method for quantitative diagnosis and monitoring of rotor misalignment faults in turbine machinery
MA Bo1, YANG Ling1, SHEN Wei2
1. Diagnosis and Self-Recovery Engineering Research Center, College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029; 2. Nuclear and Radiation Safety Center, MEP, Beijing 100082, China
Abstract:It is difficult to diagnose quantitatively the degree of misalignment in a turbine rotor system. A quantitative method for diagnosis of parallel misalignment based on monitoring data, utilizing the relationship between the misalignment of the rotor and the vibration amplitude of the node, is proposed in this work. The steps involved in the method are as follows. The rotor misalignment force is obtained by analyzing the state of the parallel misalignment rotor. A rotor model is then established to analyze the variation of rotor node vibration for different misalignments based on dynamics theory. The relationship between the vibration amplitude of the node with the misalignment is then analyzed, and modified according to the data obtained with the normal operation of the rotor. By monitoring the vibration amplitude of the node, the parallel misalignment of the rotor can be derived, and the aim of diagnosing the faults in the parallel misalignment is thus achieved. Using a test rig, the vibration of the rotor with different misalignments was analyzed by experiment. The experimental results show that the proposed method of monitoring and assessment is valid.
[1] 姚红良, 韩清凯, 李凌轩, 等. 基于谐波分量的转子系统碰摩故障定量诊断方法[J]. 机械工程学报, 2012, 48(5):43-48. Yao H L, Han Q K, Li L X, et al. Method for detecting rubbing fault in rotor system based on harmonic components[J]. Journal of Mechanical Engineering, 2012, 48(5):43-48. (in Chinese) [2] 鞠华, 沈长青, 黄伟国, 等. 基于支持向量回归的轴承故障定量诊断应用[J]. 振动、测试与诊断, 2014, 34(4):767-771. Ju H, Shen C Q, Huang W G, et al. Application of bearing fault diagnosis based on support vector regression[J]. Journal of Vibration, Measurement and Diagnosis, 2014, 34(4):767-771. (in Chinese) [3] Shi P, Chen Z, Vagapov Y, et al. A new diagnosis of broken rotor bar fault extent in three phase squirrel cage induction motor[J]. Mechanical Systems and Signal Processing, 2014, 42(1):388-403. [4] 陈非, 黄树红, 张燕平, 等. 基于过程的旋转机械振动故障定量诊断方法[J]. 动力工程, 2008, 28(4):543-547. Chen F, Huang S H, Zhang Y P, et al. Aquantitative diagnosis method of vibration faults of rotating machinery based on process[J]. Journal of Power Engineering, 2008, 28(4):543-547. (in Chinese) [5] 费成巍, 柏树生, 白广忱, 等. 转子振动故障的过程功率谱熵特征分析与定量诊断[J]. 航空发动机, 2011, 37(1):48-51. Fei C W, Bai S S, Bai G C, et al. Feature analysis and quantitative diagnosis of process power spectrum entropy for rotor vibration failure[J]. Aeroengine, 2011, 37(1):48-51. (in Chinese) [6] 于涛, 韩清凯, 孙伟, 等. 基于模态扩展与谐波分解的转子碰摩故障精确诊断[J]. 东北大学学报:自然科学版, 2006, 27(5):524-527. Yu T, Han Q K, Sun W, et al. Rotor rub fault diagnosis based on modal expansion and harmonic decomposition[J]. Journal of Northeastern University:Natural Science, 2006, 27(5):524-527. (in Chinese) [7] Bach H, Hiller R, Markert R. Representation of rotor-stator-rub in terms of equivalent forces for model based diagnostics[J]. Acoustical and Vibratory Surveillance Methods and Diagnostic Techniques, 1998, 3:723-732. [8] Zhao S F, Liang L, Xu G H, et al. Quantitative diagnosis of a spall-like fault of a rolling element bearing by empirical mode decomposition and the approximate entropy method[J]. Mechanical Systems and Signal Processing, 2013, 40(1):154-177. [9] 韩捷. 齿式联接不对中转子的故障物理特性研究[J]. 振动工程学报, 1996, 9(3):297-301. Han J. Study on the physical characteristics of the fault of the rotor with misalignment[J]. Journal of Vibration Engineering, 1996, 9(3):297-301. (in Chinese) [10] 刘占生, 赵广, 龙鑫. 转子系统联轴器不对中研究综述[J]. 汽轮机技术, 2007, 49(5):321-325. Liu Z S, Zhao G, Long X. Survey of the research on coupling with misalignment of rotary machinery[J]. Turbine Technology, 2007, 49(5):321-325. (in Chinese) [11] Mehrjou M R, Mariun N, Marhaban M H, et al. Rotor fault condition monitoring techniques for squirrel-cage induction machine-a review[J]. Mechanical Systems and Signal Processing, 2011, 25(8):2827-2848. [12] 陈果, 李兴阳. 航空发动机整机振动中的不平衡-不对中-碰摩耦合故障研究[J]. 航空动力学报, 2009, 24(10):125-132. Chen G, Li X Y. Study on imbalance-misalignment-rubbing coupling faults in aero engine vibration[J]. Journal of Aerospace Power, 2009, 24(10):125-132. (in Chinese) [13] 高兴军, 赵恒华. 大型通用有限元分析软件ANSYS简介[J]. 辽宁石油化工大学学报, 2004, 24(3):94-98. Gao X J, Zhao H H. Large general finite element analysis software ANSYS[J]. Journal of Liaoning University of Petroleum & Chemical Technology, 2004, 24(3):94-98. (in Chinese)