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Research Papers: Gas Turbines: Turbomachinery

Experimental and Numerical Investigation of the Flow in a Low-Pressure Industrial Steam Turbine With Part-Span Connectors

[+] Author and Article Information
Markus Häfele

ITSM—Institute of Thermal Turbomachinery
and Machinery Laboratory,
University of Stuttgart,
Pfaffenwaldring 6,
Stuttgart D-70569, Germany
e-mail: markus.haefele@itsm.uni-stuttgart.de

Christoph Traxinger

ITSM—Institute of Thermal Turbomachinery
and Machinery Laboratory,
University of Stuttgart,
Pfaffenwaldring 6,
Stuttgart D-70569, Germany
e-mail: christoph.traxinger@gmail.com

Marius Grübel

ITSM—Institute of Thermal Turbomachinery
and Machinery Laboratory,
University of Stuttgart,
Pfaffenwaldring 6,
Stuttgart D-70569, Germany
e-mail: marius.gruebel@itsm.uni-stuttgart.de

Markus Schatz

ITSM—Institute of Thermal Turbomachinery
and Machinery Laboratory,
University of Stuttgart,
Pfaffenwaldring 6,
Stuttgart D-70569, Germany
e-mail: markus.schatz@itsm.uni-stuttgart.de

Damian M. Vogt

ITSM—Institute of Thermal Turbomachinery
and Machinery Laboratory,
University of Stuttgart,
Pfaffenwaldring 6,
Stuttgart D-70569, Germany
e-mail: damian.vogt@itsm.uni-stuttgart.de

Roman Drozdowski

KBB—Kompressorenbau Bannewitz GmbH,
Windbergstraße 45,
Bannewitz D-01728, Germany
e-mail: roman.drozdowski@kbb-turbo.de

Contributed by the Turbomachinery Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 21, 2015; final manuscript received October 17, 2015; published online February 9, 2016. Editor: David Wisler.

J. Eng. Gas Turbines Power 138(7), 072604 (Feb 09, 2016) (12 pages) Paper No: GTP-15-1356; doi: 10.1115/1.4032205 History: Received July 21, 2015; Revised October 17, 2015

An experimental and numerical study on the flow in a three-stage low-pressure (LP) industrial steam turbine is presented and analyzed. The investigated LP section features conical friction bolts in the last and a lacing wire in the penultimate rotor blade row. These part-span connectors (PSC) allow safe turbine operation over an extremely wide range and even in blade resonance condition. However, additional losses are generated which affect the performance of the turbine. In order to capture the impact of PSCs on the flow field, extensive measurements with pneumatic multihole probes in an industrial steam turbine test rig have been carried out. State-of-the-art three-dimensional computational fluid dynamics (CFD) applying a nonequilibrium steam (NES) model is used to examine the aerothermodynamic effects of PSCs on the wet steam flow. The vortex system in coupled LP steam turbine rotor blading is discussed in this paper. In order to validate the CFD model, a detailed comparison between measurement data and steady-state CFD results is performed for several operating conditions. The investigation shows that the applied one-passage CFD model is able to capture the three-dimensional flow field in LP steam turbine blading with PSC and the total pressure reduction due to the PSC with a generally good agreement to measured values and is therefore sufficient for engineering practice.

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References

Häfele, M. , Starzmann, J. , Grübel, M. , Schatz, M. , Vogt, D. M. , Drozdowski, R. , and Völker, L. , 2014, “ Numerical Investigation of the Impact of Part-Span Connectors on Aero-Thermodynamics in a Low Pressure Industrial Steam Turbine,” ASME Paper No. GT2014-25177.
Häfele, M. , Vogt, D. M. , and Drozdowski, R. , 2014, “ Numerical Modelling of a Three Stage Low Pressure Industrial Steam Turbine With Part-Span Connectors,” ANSYS Conference & 32nd CADFEM Users' Meeting, Nuremberg, Germany, June 4–6.
Drozdowski, R. , Völker, L. , Häfele, M. , and Vogt, D. M. , 2015, “ Experimental and Numerical Investigation of the Nonlinear Vibrational Behavior of Steam Turbine Last Stage Blades With Friction Bolt Damping Elements,” ASME Paper No. GT2015-42244.
Drozdowski, R. , Völker, L. , Häfele, M. , and Vogt, D. M. , 2015, “ Numerical and Experimental Analysis of LP Steam Turbine Blades Coupled With Lacing Wire,” 11th European Conference on Turbomachinery, Fluid Dynamics and Thermodynamics, Madrid, Spain, Mar. 23–27, Paper No. ETC2015-105.
Accornero, A. , Doria, G. , Maretto, L. , and Zunino, E. , 1980, “ Flow in a 320 MW Low-Pressure Section: Theoretical and Experimental Evaluation,” Steam Turbines for Large Power Outputs (Lecture Series), von Karman Institute for Fluid Dynamics, Rhode Saint Genese, Belgium.
Accornero, A. , and Maretto, L. , 1987, “ Field Measurements in LP Cylinder of a 320 MW Turbine,” Aerothermodynamics of Low Pressure Steam Turbines and Condensers, M. J. Moore and C. H. Sieverding , eds., von Karman Institute Book/Springer, Berlin, pp. 185–197.
Rubechini, F. , Marconcini, M. , Arnone, A. , Cecchi, S. , and Daccà, F. , 2007, “ Some Aspects of CFD Modeling in the Analysis of a Low-Pressure Steam Turbine,” ASME Paper No. GT2007-27235.
Chima, R. V. , 2002, “ Computational Modeling of Vortex Generators for Turbomachinery,” ASME Paper No. GT2002-30677.
Völker, L. , 2006, “ Neue Aspekte der Aerodynamischen Gestaltung von Niederdruck-Endstufen-Beschaufelungen,” Ph.D. thesis, University of Stuttgart, Shaker Verlag, Herzogenrath, Germany.
Sigg, R. , Heinz, Ch. , Casey, M. V. , and Sürken, N. , 2009, “ Numerical and Experimental Investigation of a Low Pressure Steam Turbine During Windage,” Proc. IMechE, Part A, 223(6), pp. 697–708. [CrossRef]
Mistry, H. , Santhanakrishnan, M. , Liu, J. , Stein, A. , Dey, S. , and Slepski, J. , 2011, “ Aerodynamic Performance Assessment of Part-Span Connector of Last Stage Bucket of Low Pressure Steam Turbine,” ASME Paper No. POWER2011-55265.
Häfele, M. , Traxinger, C. , Grübel, M. , Schatz, M. , Vogt, D. M. , and Drozdowski, R. , 2015, “ Numerical and Experimental Study on Aerodynamic Optimization of Part-Span Connectors in the Last Stage of a Low-Pressure Industrial Steam Turbine,” Proc. IMechE, Part A, 229(5), pp. 465–476. [CrossRef]
Traupel, W. , 1977, Thermische Turbomaschinen, 3rd ed., Vol. 1, Springer, Berlin.
Eyb, G. , 1989, “ Experimentelle Untersuchung des Strömungsfeldes am Modell einer ND-Dampfturbinen-Endstufe,” Ph.D. thesis, University of Stuttgart, Stuttgart, Germany.
Heneka, A. , 1977, “ Strömungsmessungen an Niederdruck-Dampfturbinen,” Forschung in der Kraftwerkstechnik 1977, pp. 61–66.
Gerber, A. G. , 2008, “ Inhomogeneous Multifluid Model for Prediction of Nonequilibrium Phase Transition and Droplet Dynamics,” ASME J. Fluids Eng., 130(3), p. 031402. [CrossRef]
Young, J. B. , 1982, “ The Spontaneous Condensation of Steam in Supersonic Nozzles,” Physicochem. Hydrodyn., 3(1), pp. 57–82.
Grübel, M. , Starzmann, J. , Schatz, M. , Eberle, T. , Vogt, D. M. , and Sieverding, F. , 2015, “ Two-Phase Flow Modeling and Measurements in Low-Pressure Turbines—Part 1: Numerical Validation of Wet Steam Models and Turbine Modeling,” ASME J. Eng. Gas Turbines Power, 137(4), p. 042602. [CrossRef]
Burton, Z. , Ingram, G. L. , and Hogg, S. , 2013, “ A Literature Review of Low Pressure Steam Turbine Exhaust Hood and Diffuser Studies,” ASME J. Eng. Gas Turbines Power, 135(6), p. 062001. [CrossRef]
Musch, C. , Stüer, H. , and Hermle, G. , 2013, “ Optimization Strategy for a Coupled Design of the Last Stage and the Successive Diffuser in a Low Pressure Steam Turbine,” ASME J. Turbomach., 135(1), p. 011013. [CrossRef]
Verstraete, T. , Prinsier, J. , Sante, A. D. , Gatta, S. D. , and Cosi, L. , 2012, “ Design Optimization of a Low Pressure Steam Turbine Radial Diffuser Using an Evolutionary Algorithm and 3D CFD,” ASME Paper No. GT2012-69515.
Schatz, M. , Eberle, T. , Grübel, M. , Starzmann, J. , Vogt, D. M. , and Sürken, N. , 2015, “ Two-Phase Flow Modeling and Measurements in Low-Pressure Turbines—Part 2: Turbine Wetness Measurement and Comparison to CFD-Predictions,” ASME J. Eng. Gas Turbines Power, 137(4), p. 042603. [CrossRef]
Starzmann, J. , 2014, “ Numerische Untersuchung der Zweiphasenströmung und Analyse von Nässeverlusten in Niederdruckdampfturbinen,” Ph.D. thesis, University of Stuttgart, Shaker Verlag, Herzogenrath, Germany.

Figures

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Fig. 1

Industrial steam turbine test rig at ITSM

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Fig. 2

LP section of the industrial steam turbine with PSCs

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Fig. 3

Five-hole cone-head probe with thermocouple (head diameter = 2.5 mm and stem diameter = 6 mm) and traversing system mounted on exhaust hood

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Fig. 4

Exhaust hood with traversing systems

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Fig. 5

Sketch of the CFD model of the investigated LP industrial steam turbine with PSCs

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Fig. 6

Model of rotor R3 with PSC

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Fig. 7

Measured wall pressures at the inner diffuser ring (compare Fig. 2), projected on an axial plane

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Fig. 8

Radial profiles of total pressure, static pressure, and flow angle in evaluation plane E32

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Fig. 9

Radial profiles of total pressure, static pressure, and flow angle in evaluation plane E30

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Fig. 10

Flow velocity components in evaluation planes E30 and E32 (UT) for operating point OP-2

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Fig. 11

Vortex system in rotor R2 (left: sketch; right: visualized streamlines with 3D CFD)

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