Sage Journals: Discover world-class research

Abstract

Modern steam power plants must operate safely at extremely low loads, known as windage, in which the low pressure (LP) turbine runs with decreased or even zero flow. Windage is characterized by a strongly unsteady three-dimensional (3D) flow field leading to possible aerodynamic excitations. Extensive flow field measurements were performed in an LP steam turbine test rig during windage, using pneumatic probes in the last stage and a diffuser. The flow field of the whole turbine was also calculated with steady 3D computational fluid dynamics (ANSYS CFX). Good agreement is found between the simulations and the measurements of the flow field, and the characteristic vortex structures behind the last rotor row are captured. The numerically predicted trends of power output, pressure ratio, and temperature of the last turbine blade row closely match the experimental data. The complex vortex flow in the stage is interpreted using both numerical and experimental results.

Keywords

low-pressure steam turbine windage flow field measurements numerical calculations backflow characteristic

Get full access to this article

View all access options for this article.

References

Stastny

, Betriebsverhältnisse einer Dampf-turbine mit Endstufenventilation Energie-technik 30. Jg., 5, 1980, 176–180.

Truckenmüller

, Untersuchung zur aero-dynamisch induzierten Schwingungs-anregung von Niederdruck-Laufschaufeln bei extremer Teillast. Dissertation Universität Stuttgart 2002.

Lagun

V. P.

Simoyu

L. L.

Frumin

Yu. Z.

Povolotskii

L. V.

Sukharev

F. M.

, Distinguishing features of the operation of LPC last stages at low load and under no-load conditions. Teploenergetika, 18(2), 1971, 21–24.

Riess

Evers

, Die Strömung in mehr-stufigen Turbinen mit langen Schaufeln bei Schwachlast- und Leerlaufbetrieb. VGB Kraftwerkstechnik 65, 11, 1985, 1020–1026.

Schmidt

, Strömungsuntersuchungen in Dampf- turbinen-Endstufen im Heiz- und Schwachlastbetrieb. Dissertation Universität Hannover 1988.

Truckenmüller

Gerschütz

Stetter

Hosenfeld

H.-G.

, Examinations at a three stage low pressure model turbine during ventilation. In Proceedings of the IJPG'98 International Joint Power Generation Conference & Exposition, Baltimore, Maryland, USA, 24-26 August 1998.

Gerschütz

Casey

Truckenmüller

, Experimental investigations of rotating flow instabilities in the last stage of a low-pressure model steam turbine during windage. Proc. IMechE, Part A: J. Power and Energy, 2005, 219(A6), 499–510. DOI: 10.1243/095765005×31379.

Petrovic

Riess

, Off-design flow analysis of low-pressure steam turbines. Proc. IMechE, Part A: J. Power and Energy, 1997, 211(A3), 215–223. DOI: 10.1243/0957650971537123.

Liu

Chen

Martin

H. F.

, A primary variable throughflow code and its application to last stage reverse flow in LP steam turbine. (2000): ASME IJPGC2000-15010.

10.

Lampart

Puzyrewski

, On the importance of adaptive control in extraction/condensing turbines. In Proceedings of the ASME Turbo Expo 2006, Barcelona, 2006, GT2006-91160.

11.

Herzog

Binner

Seume

J. R.

Rothe

, Verification of low-flow conditions in a multi stage turbine. In Proceedings of the ASME Turbo Expo 2007, Montreal, 2007, GT2007-273.

12.

Herzog

Gündogdu

Kanh

Seume

J. R.

Rothe

, Part load operation of a four stage turbine. In Proceedings of the ASME Turbo Expo 2005, Reno, 2005, GT2005-68700.

13.

Stüer

Truckenmüller

Borthwick

Denton

J. D.

, Aerodynamic concept for very large steam turbine last stages. In Proceedings of the ASMETurbo Expo 2005, Reno, 2005, GT2005-68746.

14.

Wachter

Eyb

, Determination of the flow field in LP steam turbines. In Proceedings of the ASME Turbo Expo 1986, Düsseldorf, 1986, 86GT–210.

15.

Heinz

Ch.

, Strömungsfeldmessungen im Diffusor einer Modelldampfturbine bei extremer Teillast. Diplomarbeit ITSM Universität

Stuttgart

2007.

16.

Sigg

Casey

M. V.

Mayer

Sürken

, The influence of lean and sweep in a low pressure steam turbine: Analysis of three stages with a 3D CFD model. In Proceedings of the ASMETurbo Expo 2008, Berlin, 9-13 June 2008, GT2008-50161.

Numerical and experimental investigation of a low-pressure steam turbine during windage

Abstract

Abstract

Keywords

Get full access to this article

References