An accelerated deposition test facility was operated with four different coal ash species to study the effect of ash composition on deposition rate and spatial distribution. The facility seeds a combusting (natural gas) flow with 10–20 micron mass mean diameter coal ash particulate. The particulate-laden combustor exhaust is accelerated through a rectangular-to-annular transition duct and expands to ambient pressure through a nozzle guide vane annular sector. For the present study, the annular cascade consisted of two CFM56 aero-engine vane doublets, comprising three full passages and two half passages of flow. The inlet Mach number (0.1) and gas temperature (1100 °C) are representative of operating turbines. Ash samples were tested from the three major coal ranks: lignite, subbituminous, and bituminous. Investigations over a range of inlet gas temperatures from 900 °C to 1120 °C showed that deposition increased with temperature, though the threshold for deposition varied with ash type. Deposition levels varied with coal rank, with lignite producing the largest deposits at the lowest temperature. Regions of heightened deposition were noted; the leading edge and pressure surface being particularly implicated. Scanning electron microscopy was used to identify deposit structure. For a limited subset of tests, film cooling was employed at nominal design operating conditions but provided minimal protection in cases of severe deposition.

References

References
1.
Wenglarz
,
R. A.
, and
Fox
,
R. G.
Jr.
,
1990
, “
Physical Aspects of Deposition From Coal-Water Fuels Under Gas Turbine Conditions
,”
ASME J. Eng. Gas Turb. Power
,
120
, pp.
9
14
.10.1115/1.2906484
2.
Kim
,
J.
,
Dunn
,
M. G.
, and
Baran
,
A. J.
,
1993
, “
Deposition of Volcanic Materials in the Hot Sections of Two Gas Turbine Engines
,”
ASME J. Eng. Gas Turb. Power
,
115
, pp.
641
651
.10.1115/1.2906754
3.
Dunn
,
M. G.
,
Baran
,
A. J.
, and
Miatech
,
J.
,
1996
, “
Operation of Gas Turbine Engines in Volcanic Ash Clouds
,”
ASME J. Eng. Gas Turb. Power
,
118
, pp.
724
731
.10.1115/1.2816987
4.
Wenglarz
,
R. A.
,
1992
, “
An Approach for Evaluation of Gas Turbine Deposition
,”
ASME J. Eng. Gas Turb. Power
,
114
, pp.
230
234
.10.1115/1.2906577
5.
Bogard
,
D. G.
,
Schmidt
,
D. L.
, and
Tabbita
,
M.
,
1998
, “
Characterization and Laboratory Simulation of Turbine Airfoil Surface Roughness and Associated Heat Transfer
,”
ASME J. Turbomach.
,
120
, pp.
337
342
.10.1115/1.2841411
6.
Hussein
,
M. F.
, and
Tabakoff
,
W.
,
1971
,“
Computation and Plotting of Solid Particle Flow in Rotating Cascades
,”
Comput. Fluids
,
2
(
1
), pp.
1
15
.10.1016/0045-7930(74)90002-4
7.
Tabakoff
,
W.
, and
Hussein
,
M. F.
,
1971
, “
Trajectories of Particles Suspended in Flows Through Cascades
,”
J. Aircraft
,
8
(
1
), pp.
60
64
.10.2514/3.44229
8.
Tafti
,
D. K.
, and
Sreedharan
,
S. S.
,
2010
, “
Composition Dependent Model for the Prediction of Syngas Ash Deposition With the Application to a Leading Edge Turbine Vane
,”
ASME Turbo Expo 2010: Power for Land, Sea, and Air.
9.
Barker
,
B.
,
Casaday
,
B.
,
Shankara
,
P.
,
Ameri
,
A.
, and
Bons
,
J. P.
,
2011
, “
Coal Ash Deposition on Nozzle Guide Vanes—Part II- Computational Modeling
,”
ASME Turbo Expo 2011: Power for Land, Sea, and Air
,
Jun.
14–18
,
Vancouver, Canada
, Paper # GT2011-46660.
10.
Lawson
,
S. A.
, and
Thole
,
K.
,
2011
, “
The Effects of Simulated Particle Deposition on Film Cooling
,”
ASME J. Turbomach.
,
133
(
2
), p. 021009.10.1115/1.4000571
11.
Vandsburger
,
U.
,
Tafti
,
D.
, and
Ng
,
W.
,
2009
, “
Syngas Particulate Deposition and Erosion at the Leading Edge of a Turbine Blade With Film Cooling
,”
University Turbine Systems Research Workshop
,
Oct.
27–29
,
Orlando, FL.
12.
Jensen
,
J. W.
,
Squire
,
S. W.
,
Bons
,
J. P.
, and
Fletcher
,
T. H.
,
2005
, “
Simulated Land-Based Turbine Deposits Generated in an Accelerated Deposition Facility
,”
J. Turbomach.
,
127
, pp.
462
470
.10.1115/1.1860380
13.
Crosby
,
J. M.
,
Lewis
,
S.
,
Bons
,
J. P
,
Ai
,
W.
, and
Fletcher
,
T. H.
,
2008
, “
Effects of Temperature and Particle Size on Deposition in Land Based Turbines.
ASME J. Eng. Gas Turb. Power
,
130
(
5
), p.
051503
.10.1115/1.2903901
14.
Smith
,
C.
,
Barker
,
B.
,
Clum
,
C.
, and
Bons
,
J.
,
2010
Deposition in a Turbine Cascade With Combusting Flow
,”
ASME Turbo Expo 2010: Power for Land, Sea, and Air
,
June
2010
,
Glasgow, Scotland
, Paper #:GT2010-22855.
15.
Coleman
,
H. W.
, and
Steele
,
W. G.
,
1999
,
Experimentation and Uncertainty Analysis for Engineers
.
2nd ed.
,
Wiley Interscience
,
New York
.
16.
Chambers
,
J. G.
,
1985
, “
The Volcanic Cloud Encounter of a Rolls-Royce Powered Boeing 747 of the British Airways Fleet 24 June 1982
,”
Internal Rolls-Royce Report.
You do not currently have access to this content.