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.

References

1.
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.
2.
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.
3.
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.
4.
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.
5.
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
.
6.
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
.
7.
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.
8.
Chima
,
R. V.
,
2002
, “
Computational Modeling of Vortex Generators for Turbomachinery
,”
ASME
Paper No. GT2002-30677.
9.
Völker
,
L.
,
2006
, “
Neue Aspekte der Aerodynamischen Gestaltung von Niederdruck-Endstufen-Beschaufelungen
,” Ph.D. thesis, University of Stuttgart, Shaker Verlag, Herzogenrath, Germany.
10.
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
.
11.
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.
12.
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
.
13.
Traupel
,
W.
,
1977
,
Thermische Turbomaschinen
, 3rd ed., Vol.
1
,
Springer
,
Berlin.
14.
Eyb
,
G.
,
1989
, “
Experimentelle Untersuchung des Strömungsfeldes am Modell einer ND-Dampfturbinen-Endstufe
,” Ph.D. thesis, University of Stuttgart, Stuttgart, Germany.
15.
Heneka
,
A.
,
1977
, “
Strömungsmessungen an Niederdruck-Dampfturbinen
,” Forschung in der Kraftwerkstechnik 1977, pp.
61
66
.
16.
Gerber
,
A. G.
,
2008
, “
Inhomogeneous Multifluid Model for Prediction of Nonequilibrium Phase Transition and Droplet Dynamics
,”
ASME J. Fluids Eng.
,
130
(
3
), p.
031402
.
17.
Young
,
J. B.
,
1982
, “
The Spontaneous Condensation of Steam in Supersonic Nozzles
,”
Physicochem. Hydrodyn.
,
3
(
1
), pp.
57
82
.
18.
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
.
19.
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
.
20.
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
.
21.
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.
22.
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
.
23.
Starzmann
,
J.
,
2014
, “
Numerische Untersuchung der Zweiphasenströmung und Analyse von Nässeverlusten in Niederdruckdampfturbinen
,” Ph.D. thesis, University of Stuttgart, Shaker Verlag, Herzogenrath, Germany.
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