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http://dx.doi.org/10.5293/KFMA.2004.7.6.045

The Leakage and Rotordynamic Analysis of A Combination-Type-Staggered-Labyrinth Seal for A Steam Turbine  

Ha, Tae-Woong (경원대학교 건축설비 기계공학부)
Lee, Yong-Bok (한국과학기술연구원 트라이볼로지 연구센터)
Kim, Seung-Jong (한국과학기술연구원 트라이볼로지 연구센터)
Kim, Chang-Ho (한국과학기술연구원 트라이볼로지 연구센터)
Publication Information
The KSFM Journal of Fluid Machinery / v.7, no.6, 2004 , pp. 45-54 More about this Journal
Abstract
Governing equations and numerical solution methods are derived for the analysis of a combination-type-staggered-labyrinth seal used in high performance steam turbines. A bulk flow is assumed for each combination-type-staggered-labyrinth cavity. Axial flow through a throttling labyrinth strip is determined by Neumann's leakage equation and circumferential flow is assumed to be completely turbulent in the labyrinth cavity. Moody's wall-friction-factor formula is used for the calculation of wall shear stresses. For the reaction force developed by the seal, linearized zeroth-order and first-order perturbation equations are developed for small motion near the centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the combination-type-staggered-labyrinth seal. Theoretical results of leakage and rotordynamic characteristics for the IP4-stage seal of USC (ultra super critical) steam turbine are shown with the effect of sump pressure, the number of throttling labyrinth strip, and rotor speed.
Keywords
Combination-type-staggered-labyrinth seal; Leakage; Rotordynamic coefficients; Moody's fiction factor; Steam turbine;
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  • Reference
1 Ha, T. W. and Childs, D. W., 1994, 'Annular Honeycomb-stator Turbulent Gas Seal Analysis Using a New Friction-Factor Model Based on Flat Plate Tests', ASME Journal of Tribology, Vol. 116, pp. 352-360   DOI   ScienceOn
2 Iwatsubo, T. ,1980, 'Evaluation of Instability Forces of Labyrinth Seals in Turbines or Compressors,' NASA CP 2133 Proceedings of a workshop at Texas A&M University 12-14 May Entitled Rotordynamic Instability Problems in High Performance Turbomachinery, pp. 139-167
3 Jenny, R. J., Wyssmann, H. P., and Pham, T. C., 1984, 'Prediction of Stiffness and Damping Coefficients for Centrifugal Compressor Labyrinth Seals,' ASME 84-GT-86. Presented at the 29th International Gas Turbine Conference and Exhibit, Amsterdam, The Netherlands, June 4-7
4 Childs, D. W., and Scharrer, J. K., 1986, ‘An Iwatsubo Based Solution for Labyrinth Seals: A Comparison to Experimental Results,' ASME Trans. Journal of Engineering for Gas Turbines and Power, April Vol. 108, pp. 325-331
5 Scharrer, J. 1987, 'A Comparison of Experimental and Theoretical Results for Labyrinth Gas Seals,' Ph. D. Dissertation, Texas A&M University
6 하태웅, 이안성, 1998, '압축기용 라비린스 실의 동특성 해석' 한국소음진동공학회지,제8권, 제5호, pp. 849-855
7 Scharrer, J. K., 1988, 'Rotordynamic Coefficients for Stepped Labyrinth Gas Seals,' ASME/ASLE Tribology Conference, Paper No. 88-Trib-42
8 Ha, T. W., 2001, 'Rotordynamic Analysis for Stepped-Labyrinth Gas Seal Using Moody’s Friction-Factor Model,' KSME International Journal, Vol. 15, No. 9, pp. 1079-1089
9 하태웅, 2002, '엇갈린 래버린스 실의 누설량 및 동특성 해석' 윤활학회지, 제18권, 제1호，pp. 24-33
10 Van Wylen, G. J., Sonntag, R. E., Borgnakke, C., 1994, Fundamentals of Classical Thermodynamics, Wiley
11 Neumann, K. 1964, 'Zur Frage der Verwendung von Durchblickdichtungen im Dampgturbinebau,' Maschinentech- nik, 13(4)
12 Vermes, G., 1961, 'A Fluid Mechanics Approach to the Labyrinth Seal Leakage Problem,' ASME Journal of Engineering for Power, Vol. 83, No. 2, April pp. 161-169   DOI
13 Gurevich, M. I., 1966, The Theory of Jets In an Ideal Fluid, Pergamon Press, London, England, pp. 319-323
14 John, J. E. A., 1979, Gas Dynamics, Wylie
15 Alford, J. S., 1965, 'Protecting Turbomachinery from Self- Excited Rotor Whirl, ' ASME Trans. Journal of Engineering for Power, October pp. 333~344