Abstract

Uneven pressure drops among stages of multistage brush seal (MBS) leads to early failure of single-stage seal units, which directly affects service life of the seal used in aeroengines, gas turbines, and steam turbines. In this paper, influence factors of interstage pressure drop were studied to analyze formation mechanism of the uneven pressure drops. Moreover, an MBS with differentiated structure was presented, and its interstage pressure drops were further investigated. The results showed that the MBS with several same single-stage seal units had uneven pressure drops among stages under high inlet/outlet pressure ratios. In view of remarkably increasing velocity and decreasing pressure in downstream region of bristle pack near rotor surface during flow of airflow, adjustments of structural parameters (i.e., increasing height of backing plate to rotor surface Hb, increasing seal clearance Hg, and decreasing axial width of bristle pack B) could improve the uneven pressure drops among different stages due to increasing outlet air flow area of the stage. The closer pressure drop proportions of different stages to ideal average value indicated increase of Hb had a more effective effect to balance the pressure drops among different stages compared to increase of Hg and decrease of B. An MBS with differentiated structure, in which both Hb and Hg of all the single-stage seal units were increased progressively and B was decreased step by step, showed a good performance to obtain even interstage pressure drops.

References

1.
Bayley
,
F. J.
, and
Long
,
C. A.
,
1993
, “
A Combined Experimental and Theoretical Study of Flow and Pressure Distributions in a Brush Seal
,”
ASME J. Eng. Gas Turbines Power
,
115
(
2
), pp.
404
410
.10.1115/1.2906723
2.
Dinc
,
S.
,
Demiroglu
,
M.
,
Turnquist
,
N.
,
Mortzheim
,
J.
,
Goetze
,
G.
,
Maupin
,
J.
,
Hopkins
,
J.
,
Wolfe
,
C.
, and
Florin
,
M.
,
2022
, “
Fundamental Design Issues of Brush Seals for Industrial Applications
,”
ASME J. Turbomach.
,
124
(
2
), pp.
293
300
.10.1115/1.1451847
3.
Chupp
,
R. E.
,
Hendricks
,
R. C.
,
Lattime
,
S. B.
,
Steinetz
,
B. M.
, and
Glenn
,
J. H.
,
2006
, “
Sealing in Turbomachinery
,”
J. Propul. Power
,
22
(
2
), pp.
313
349
.10.2514/1.17778
4.
Sun
,
D.
,
Liu
,
N. N.
,
Fei
,
C. W.
,
Hu
,
G. Y.
,
Ai
,
Y. T.
, and
Choy
,
Y. S.
,
2016
, “
Theoretical and Numerical Investigation on the Leakage Characteristics of Brush Seals Based on Fluid-Structure Interaction
,”
Aerosp. Sci. Technol.
,
58
(
5
), pp.
207
216
.10.1016/j.ast.2016.08.023
5.
Qiu
,
B.
,
Li
,
J.
, and
Yan
,
X.
,
2014
, “
Investigation Into the Flow Behavior of Multi-Stage Brush Seals
,”
Proc. Inst. Mech. Eng., Part A
,
228
(
A4
), pp.
416
428
.10.1177/0957650914522456
6.
Bhate
,
N.
,
Thermos
,
A. C.
,
Aksit
,
M. F.
,
Demiroglu
,
M.
, and
Kizil
,
H.
,
2004
, “
Non-Metallic Brush Seals for Gas Turbine Bearings
,”
ASME
Paper No. GT2004-54296. 10.1115/GT2004-54296
7.
Lee
,
J. J.
,
Kang
,
S. Y.
,
Kim
,
T. S.
, and
Byun
,
S. S.
,
2017
, “
Thermo-Economic Analysis on the Impact of Improving Inter-Stage Packing Seals in a 500 MW Class Supercritical Steam Turbine Power Plant
,”
Appl. Therm. Eng.
,
121
(
3
), pp.
974
983
.10.1016/j.applthermaleng.2017.04.138
8.
Jia
,
X. Y.
,
Zheng
,
Q.
,
Jiang
,
Y. T.
, and
Zhang
,
H.
,
2019
, “
Leakage and Rotordynamic Performance of T Type Labyrinth Seal
,”
Aerosp. Sci. Technol.
,
88
(
5
), pp.
22
31
.10.1016/j.ast.2019.02.043
9.
Pugachev
,
A. O.
, and
Helm
,
P.
,
2009
, “
Calibration of Porous Medium Models for Brush Seals
,”
Proc. Inst. Mech. Eng., Part A
,
223
(
a1
), pp.
83
91
.10.1243/09576509JPE641
10.
Carlile
,
J. A.
,
Hendricks
,
R. C.
, and
Yoder
,
D. A.
,
1993
, “
Brush seal Leakage Performance With Gaseous Working Flu-Ids at Static and Low Rotor Speed Conditions
,”
ASME J. Eng. Gas Turbines Power
,
115
(
2
), pp.
397
403
.10.1115/1.2906722
11.
Raben
,
M.
,
Friedrichs
,
J.
,
Helmis
,
T.
, and
Flegler
,
J.
,
2016
, “
Brush Seals Used in Steam Environments-Chronological Wear Development and the Impact of Different Seal Designs
,”
ASME J. Eng. Gas Turbines Power
,
138
(
5
), p. 051901.10.1115/1.4031531
12.
Raben
,
M.
,
Friedrichs
,
J.
, and
Flegler
,
J.
,
2016
, “
Brush seal Frictional Heat Generation-Test Rig Design and Validation Under Steam Environment
,”
ASME J. Eng. Gas Turbines Power
,
139
(
3
), p. 032502.10.1115/1.4034500
13.
Ma
,
D. Q.
,
Li
,
J.
,
Zhang
,
Y. Q.
,
Li
,
Z. G.
,
Yan
,
X.
, and
Song
,
L. M.
,
2020
, “
Application of Blade Tip Shroud Brush Seal to Improve the Aerodynamic Performance of Turbine Stage
,”
Proc. Inst. Mech. Eng., Part A
,
234
(
6
), pp.
777
794
.10.1177/0957650919883153
14.
Chen
,
L. H.
,
Jones
,
T. V.
,
Chew
,
J. W.
, and
Wood
,
P. E.
,
2000
, “
Detailed experimental Studies of Flow in Large Scale Brush Seal Model and a Comparison With CFD Predictions
,”
ASME J. Eng. Gas Turbines Power
,
122
(
4
), pp.
672
679
.10.1115/1.1287265
15.
Turner
,
M. T.
,
Chew
,
J. W.
, and
Long
,
C. A.
,
1998
, “
Experimental investigation and Mathematical Modeling of Clearance Brush Seals
,”
ASME J. Eng. Gas Turbines Power
,
120
(
3
), pp.
573
579
.10.1115/1.2818185
16.
Wei
,
Y.
,
Dowell
,
E. H.
,
Chen
,
Z. B.
,
Jiao
,
Y. H.
, and
Zhang
,
Z. Q.
,
2017
, “
Influence of Geometry on Rotordynamic Coefficients of Brush Seal
,”
Int. J. Turbo Jet Eng.
,
34
(
2
), pp.
155
166
.10.1515/tjj-2015-0063
17.
Dogu
,
Y.
, and
Aksit
,
M. F.
,
2006
, “
Effects of Geometry on Brush Seal Pressure and Flow Fields-Part I: Front Plate Configurations
,”
ASME J. Turbomach.
,
128
(
2
), pp.
367
378
.10.1115/1.2101857
18.
Hendricks
,
R. C.
,
Griffin
,
T. A.
,
Kline
,
T. R.
,
Kline
,
R. C.
,
Arvind
,
P.
, and
Dvandra
,
S.
,
1994
, “
Relative Performance Comparison Between Baseline Labyrinth and Dual Brush Compressor Discharge Seals in a T-700 Engine Test
,”
ASME
Paper No. 94-GT-266.
10.1115/94-GT-266
19.
Pugachev
,
A. O.
, and
Deckner
,
M.
,
2012
, “
Experimental and Theoretical Rotordynamic Stiffness Coefficients for a Three-Stage Brush Seal
,”
Mech. Syst. Signal Process.
,
31
, pp.
143
154
.10.1016/j.ymssp.2012.03.015
20.
Luis
,
S. A.
,
Jose
,
B.
, and
Adolfo
,
D.
,
2010
, “
Rotordynamic Force Coefficients of a Hybrid Brush Seal: Measurements and Predictions
,”
ASME J. Eng. Gas Turbines Power
,
132
(
4
), p. 042503.10.1115/1.3159377
21.
Fan
,
J. J.
,
Ji
,
H. H.
,
Wang
,
Q.
,
Hu
,
Y. P.
, and
Kong
,
X. Y.
,
2021
, “
A combined Theoretical and Experimental Study of Wear Model of Brush Seal
,”
Tribol. Int.
,
154
(
2
), p.
106696
.10.1016/j.triboint.2020.106696
22.
Crudgington
,
P.
,
Bowsher
,
A.
,
Walia
,
J.
, and
Lloyd
,
D.
,
2009
, “
Bristle angle Effects on Brush Seal Contact Pressures
,”
AIAA
Paper No. AIAA 2009-5168. 10.2514/6.2009-5168
23.
Ma
,
D. Q.
,
Li
,
Z. G.
, and
Li
,
J.
,
2021
, “
A Three-Dimensional Tube Bundle Model Analysis for Leakage Flow Characteristics of Variable Bristle Diameter Brush Seals With Bristle Pack Stratification
,”
ASME J. Eng. Gas Turbines Power
,
143
(
5
), p. 051014.10.1115/1.4050065
You do not currently have access to this content.