Browse > Article
http://dx.doi.org/10.5050/KSNVE.2010.20.1.029

Vibration Analysis for the L-1 Stage Bladed-disk of a LP Steam Turbine  

Lee, Doo-Young (한전전력연구원)
Bae, Yong-Chae (한전전력연구원)
Kim, Hee-Soo (한전전력연구원)
Lee, Yook-Ryun (한전전력연구원)
Kim, Doo-Young (한전전력연구원)
Publication Information
Transactions of the Korean Society for Noise and Vibration Engineering / v.20, no.1, 2010 , pp. 29-35 More about this Journal
Abstract
This paper studies causes of the L-1 blade damage of a low pressure turbine, which was found during the scheduled maintenance, in 500 MW fossil power plants. Many failures of turbine blades are caused by the coupling of aerodynamic forcing with bladed-disk vibration characteristics. In this study the coupled vibration characteristics of the L-1 turbine bladed-disk in a fossil power plant is shown for the purpose of identifying the root cause of the damage and confirming equipment integrity. First, analytic and experimental modal analysis for the bladed-disk at zero rpm as well as a single blade were performed and analyzed in order to verify the finite element model, and then steady stresses, natural frequencies and corresponding mode shapes, dynamic stresses were calculated for the bladed-disk under operation. Centrifugal force and steady steam force were considered in calculation of steady and dynamic stress. The proximity of modes to sources of excitation was assessed by means of an interference diagram to examine resonances. In addition, fatigue analysis was done for the dangerous modes of operation by a local strain approach. It is expected that these dynamic characteristics will be used effectively to identify the root causes of blade failures and to perform prompt maintenance.
Keywords
Turbine Blade; Modal Analysis; Nodal Diameter; Interference Diagram; Fatigue;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 McCloskey, T. H., Dooley, R. B. and McNaughton, W. P., 1999, “Turbine Steam Path Damage: Theory and Practice,” EPRI, Palo Alto.
2 Rao, J. S., 1991, “Turbomachine Blade Vibration,” John Wiley & Sons, New York.
3 Lam, T. C., Rieger, N. F. and Mccloskey, T. H., 1988, “Turbine Blade Life Assessment and Improvement,” Proceedings of the American Power Conference, Vol. 50, pp. 191-203.
4 Lee, D. Y., Bae, Y. C., Kim, H. S. and Lee, Y. R., 2009, “Vibration Analysis of a Low Pressure Turbine Bladed Disk in 500MW Fossil Power Plants,” The Journal of the Acoustical Society of America, Vol. 125, No. 4, Pt. 2 of 2, pp. 2624-2625.
5 Stress Technology Incorporated, 2002, “Blade-ST & STELLA Manual,” Rochester, New York.
6 Gandy, D., 2005, “Combustion Turbine F-Class Life Management,” EPRI Technical Report 1011490, EPRI, Palo Alto.
7 Rao, J. S., 2000, “Turbine Blade Life Estimation,” Alpha Science International Ltd., Pangbourne.
8 Tsai, G. C., 2004, “Rotating Vibration Behavior of the Turbine Blades with Different Groups of Blades,” Journal of Sound and Vibration, Vol. 271, pp. 547-575.   DOI   ScienceOn
9 Kim, H. S., Bae, Y. C. and Lee, H., 2005, “Identification of Failure Cause for 300MW LP Turbine Blade,” Transactions of the Korean Society for Noise and Vibration Engineering, Vol. 15, No. 9, pp. 1100-1107.   DOI
10 Shiga, M., 1989, “Vibration Characteristics of Grouped Steam Turbine Blades,” JSME International Journal, Series III, Vol. 32, No. 4, pp. 592-596.
11 Rieger, N. F., 1989, “The Relationship between Finite Element Analysis and Modal Analysis,” Sound and Vibration Magazine, Acoustical Publications, Bay Village, pp. 36-40.
12 Orsagh, R. F. and Roemer, M. J., 1994, “Examination of Successful Modal Analysis Techniques Used for Bladed-disk Assemblies,” Technical Report, Impact Technologies, New York.