Sealing technology is a key feature to improve efficiency of steam turbines for both new power stations and modernization projects. One of the most powerful sealing alternatives for reducing parasitic leakages in the blade path of a turbine as well as in shaft sealing areas is the use of brush seals, which are also widely used in gas turbines and turbo compressors. The advantage of brush seals over other sealing concepts is based on the narrow gap that is formed between the brush seal bristle tips and the mating rotor surface together with its radial adaptivity. While the narrow gap between the bristle tips and the rotor leads to a strongly decreased flow through the seal compared with conventional turbomachinery seals, it is important to be aware of the tight gap that can be bridged by relative motion between the rotor and the brush seal, leading to a contact of the bristles and the rotor surface. Besides abrasive wear occurrence, the friction between the bristles and the rotor leads to heat generation which can be detrimental to turbine operation due to thermal effects, leading to rotor bending connected to increasing shaft vibrations. In order to investigate the frictional heat generation of brush seals, different investigation concepts have been introduced through the past years. To broaden the knowledge about frictional heat generation and to make it applicable for steam turbine applications, a new testing setup was designed for the steam test rig of the Institute of Jet Propulsion and Turbomachinery—TU Braunschweig, Germany, enabling temperature measurements in the rotor body under stationary and transient operation in steam by using rotor-integrated thermocouples. Within this paper, the development of the instrumented new rotor design and all relevant parts of the new testing setup is shown along with the testing ability by means of the validation of the test rig concept and the achieved measurement accuracy. First results prove that the new system can be used to investigate frictional heat generation of brush seals under conditions relevant for steam turbine shaft seals.

References

References
1.
Schwarz
,
H.
,
Friedrichs
,
J.
, and
Flegler
,
J.
,
2014
, “
Axial Inclination of the Bristle Pack, a New Design Parameter of Brush Seals for Improved Operational Behavior in Steam Turbines
,”
ASME
Paper No. GT2014-26330.
2.
Owen
,
A. K.
,
Jones
,
T. V.
,
Guo
,
S. M.
, and
Hogg
,
S. I.
,
2003
, “
An Experimental and Theoretical Study of Brush Seal and Shaft Thermal Interaction
,”
ASME
Paper No. GT2003-38276.
3.
Demiroglu
,
M.
, and
Tichy
,
J. A.
,
2007
, “
An Investigation of Heat Generation Characteristics of Brush Seals
,”
ASME
Paper No. GT2007-28043.
4.
Pfefferle
,
D.
,
Dullenkopf
,
K.
, and
Bauer
,
H.-J.
,
2011
, “
Design and Validation of a New Test Rig for Brush Seal Testing Under Engine Relevant Conditions
,”
ASME
Paper No. GT2011-45107.
5.
Raben
,
M.
,
Friedrichs
,
J.
,
Flegler
,
J.
, and
Helmis
,
T.
,
2015
, “
Brush Seals Used in Steam Environments—Chronological Wear Development and the Impact of Different Seal Designs
,”
ASME
Paper No. GT2015-43184.
6.
Raben
,
M.
,
Schwarz
,
H.
, and
Friedrichs
,
J.
,
2013
, “
Operating Performance and Wear Investigations of Brush Seals for Steam Turbine Applications
,”
ASME
Paper No. GT2013-95442.
7.
Schwarz
,
H.
,
Friedrichs
,
J.
, and
Flegler
,
J.
,
2012
, “
Design Parameters of Brush Seals and their Impact on Seal Performance
,”
ASME
Paper No. GT2012-68956.
8.
Crudgington
,
P. F.
,
1998
, “
Brush Seal Performance Evaluation
,”
34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
AIAA
Paper No. 98-3172.
9.
Berard
,
G.
, and
Short
,
J.
,
1999
, “
Influence of Design Features on Brush Seal Performance
,”
35th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
AIAA
Paper No. 99-2685.
10.
Neef
,
M.
,
Sürken
,
N.
,
Walkenhorst
,
J.
, and
Sulda
,
E.
,
2006
, “
Design Features and Performance Details of Brush Seals For Turbine Applications
,”
ASME
Paper No. GT2006-90404.
11.
Demiroglu
,
M.
,
Gursoy
,
M.
, and
Tichy
,
J. A.
,
2007
, “
An Investigation of Tip Force Characteristics of Brush Seals
,”
ASME
Paper No. GT2007-28042.
12.
Dogu
,
Y.
, and
Aksit
,
M.
,
2006
, “
Brush Seal Temperature Distribution Analysis
,”
ASME J. Eng. Gas Turbines Power.
,
128
(
3
), pp.
599
609
.
13.
Crudgington
,
P. F.
, and
Bowsher
,
A.
,
2002
, “
Brush Seal Pack Hysteresis
,”
38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
AIAA
Paper No. 2002-3794.
14.
Qiu
,
B.
, and
Li
,
J.
,
2013
, “
Numerical Investigations on the Heat Transfer Behavior of Brush Seals Using Combined Computational Fluid Dynamics and Finite Element Method
,”
ASME J. Heat Transfer
,
135
(
12
), p.
122601
.
15.
Crudgington
,
P. F.
,
Bowsher
,
A.
,
Lloyd
,
D.
, and
Walia
,
J.
,
2009
, “
Bristle Angle Effects on Brush Seal Contact Pressures
,”
45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
AIAA
Paper No. 2009-5168.
16.
Franceschini
,
G.
,
Morgan
,
J. J.
,
Jones
,
T. V.
, and
Gillespie
,
D. R. H.
,
2006
, “
A Slow-Speed Rotating Test Facility for Characterising the Stiffness of Brush Seals
,”
ASME
Paper No. GT2006-91335.
17.
Franceschini
,
G.
,
Jones
,
T. V.
, and
Gillespie
,
D. R. H.
,
2010
, “
Improved Understanding of Blow-Down in Filament Seals
,”
ASME J. Turbomach.
,
132
(
4
), p.
041004
.
18.
Aksit
,
M.
,
Dogu
,
Y.
,
Kandemir
,
I.
, and
Kizil
,
H.
,
2006
, “
An Investigation of Pressure Stiffness Coupling in Brush Seals
,”
Eleventh International Symposium on Transport Phenomena and Dynamics of Rotating Machinery
(
ISROMAC-11-4
), Honolulu, HI, Feb. 26–Mar. 2.http://research.sabanciuniv.edu/1144/1/3011800000701.pdf
19.
Bidkar
,
R. A.
,
Demiroglu
,
M.
,
Zheng
,
X.
, and
Turnquist
,
N.
,
2011
, “
Stiffness Measurement for Pressure-Loaded Brush Seals
,”
ASME
Paper No. GT2011-45399.
20.
Fellenstein
,
J. A.
, and
DellaCorte
,
C.
,
1995
, “
A New Tribological Test for Candidate Brush Seal Materials Evaluation
,” Technical Report No. NASA/TM-106753.
21.
Duran
,
E. T.
,
Ozmusul
,
M.
, and
Aksit
,
M. F.
,
2015
, “
Brush Seal Structural Analysis and Correlation With Tests for Turbine Conditions
,”
ASME
Paper No. GT2015-44067.
22.
Duran
,
E. T.
,
Ozmusul
,
M.
, and
Aksit
,
M. F.
,
2015
, “
CAE Based Brush Seal Characterization for Stiffness and Stress Levels
,”
ASME
Paper No. GT2015-44068.
23.
Duran
,
E. T.
,
Ozmusul
,
M.
, and
Aksit
,
M. F.
,
2015
, “
Brush Seal Free State Stiffness Analyses, Tests and Inspection on Dynamic Effects
,”
ASME
Paper No. GT2015-44069.
24.
Long
,
C. A.
, and
Marras
,
Y.
,
1995
, “
Contact Force Measurements Under a Brush Seal
,”
ASME
Paper No. 95-GT-211.
25.
Büscher
,
S.
,
2010
, “
Untersuchung von mehrstufigen Bürstendichtungen für Dampfturbinen
,” Ph.D thesis, TU Braunschweig,
Institute of Jet Propulsion and Turbomachinery, Verlag und Bildarchiv W.H. Faragallah
,
Braunschweig, Germany
.
26.
Pröstler
,
S.
,
2005
, “
Modellierung und numerische Berechnungen von Wellenabdichtungen in Bürstenbauart
,” Ph.D thesis, Bochum University, Verlag Dr. Hut, Munich, Germany.
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