The flame structure and the limits of operation of a lean premixed swirl flame were experimentally investigated under piloted and nonpiloted conditions. Flame stabilization and blow out limits are discussed with respect to pilot fuel injection and combustor liner cooling for lean operating conditions. Two distinctly different flow patterns are found to develop depending on piloting and liner cooling parameters. These flow patterns are characterized with respect to flame stability, blow out limits, combustion noise, and emissions. The combustion system explored consists of a single burner similar to the burners used in Siemens annular combustion systems. The burner feeds a distinctively nonadiabatic combustion chamber operated with natural gas under atmospheric pressure. Liner cooling is mimicked by purely convective cooling and an additional flow of “leakage air” injected into the combustion chamber. Both additional air flow and the pilot fuel ratio were found to have a strong influence on the flow structure and stability of the flame close to the lean blow off (LBO) limit. It is shown by laser Doppler velocimetry that the angle of the swirl cone is strongly affected by pilot fuel injection. Two distinct types of flow patterns are observed close to LBO in this large scale setup: While nonpiloted flames exhibit tight cone angles and small inner recirculation zones (IRZs), sufficient piloting results in a wide cone angle and a large IRZ. Only in the latter case, the main flow becomes attached to the combustor liner. Flame structures deduced from flow fields and CH-chemiluminescence images depend on both the pilot fuel injection and liner cooling.

1.
Gupta
,
A.
,
Lilley
,
D.
, and
Syred
,
N.
, 1984,
Swirl Flows
,
ABACUS
,
Tunbridge Wells, UK
.
2.
Meier
,
W.
,
Weigand
,
P.
,
Duan
,
X.
, and
Giezendanner-Thoben
,
R.
, 2007, “
Detailed Characterization of the Dynamics of Thermoacoustic Pulsations in a Lean Premixed Swirl Flame
,”
Combust. Flame
0010-2180,
150
(
1–2
), pp.
2
26
.
3.
Beck
,
C. H.
,
Koch
,
R.
, and
Bauer
,
H. -J.
, 2009, “
Identification of Droplet Burning Modes in Lean, Partially Prevaporized Swirl-Stabilized Spray Flames
,”
Proc. Combust. Inst.
1540-7489,
32
, pp.
2195
2203
.
4.
Lechner
,
C.
, and
Seume
,
J.
, 2003,
Stationäre Gasturbinen
,
Springer-Verlag
,
Berlin, Heidelberg
.
5.
Streb
,
H.
,
Prade
,
B.
,
Hahner
,
T.
, and
Hoffmann
,
S.
, 2001, “
Advanced Burner Development for the Vx4.3A Gas Turbines
,” ASME Paper No. 2001-GT-0077.
6.
Hermsmeyer
,
H.
,
Prade
,
B.
,
Gruschka
,
U.
,
Schmitz
,
U.
,
Hoffmann
,
S.
, and
Krebs
,
W.
, 2002, “
V64.3A Gas Turbine Natural Gas Burner Development
,” ASME Paper No. GT-2002-30106.
7.
Prade
,
B.
,
Steb
,
H.
,
Berenbrink
,
P.
,
Schetter
,
B.
, and
Pyka
,
G.
, 1996, “
Development of an Improved Hybrid Burner—Initial Operating Experience in a Gas Turbine
,” ASME Paper No. 96-GT-45.
8.
Schildmacher
,
K. -U.
, and
Koch
,
R.
, 2005, “
Experimental Investigations of the Interaction of Unsteady Flow With Combustion
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
127
, pp.
295
300
.
9.
Dannecker
,
R.
,
Schildmacher
,
K. -U.
,
Noll
,
B.
,
Koch
,
R.
,
Hase
,
M.
,
Krebs
,
W.
, and
Aigner
,
M.
, 2007, “
Impact of Radiation on the Wall Heat Flux at a Test Bench Gas Turbine Combustion Chamber: Measurements and CFD Simulation
,” ASME Paper No. GT2007-27148.
10.
Sengissen
,
A.
,
Giauque
,
A.
,
Staffelbach
,
G.
,
Porta
,
M.
,
Krebs
,
W.
,
Kaufmann
,
P.
, and
Poinsot
,
T. J.
, 2007, “
Large Eddy Simulation of Piloting Effects on Turbulent Swirling Flames
,”
Proc. Combust. Inst.
1540-7489,
31
, pp.
1729
1736
.
11.
Schildmacher
,
K. -U.
,
Koch
,
R.
,
Wittig
,
S.
,
Krebs
,
W.
, and
Hoffmann
,
S.
, 2000, “
Experimental Investigations of the Temporal Air-Fuel Mixing Fluctuations and Cold Flow Instabilities of a Premixing Gas Turbine Burner
,” ASME Paper No. 2000-GT-84.
12.
Schildmacher
,
K. -U.
,
Koch
,
R.
, and
Bauer
,
H. -J.
, 2006, “
Experimental Characterization of Premixed Flame Instabilities of a Model Gas Turbine Burner
,”
Flow, Turbul. Combust.
1386-6184,
76
, pp.
177
197
.
13.
Schildmacher
,
K. -U.
,
Hoffmann
,
A.
,
Selle
,
L.
,
Koch
,
R.
,
Schulz
,
C.
,
Bauer
,
H. -J.
,
Poinsot
,
T.
,
Krebs
,
W.
, and
Prade
,
B.
, 2007, “
Unsteady Flame and Flow Field Interaction of a Premixed Model Gas Turbine Burner
,”
Proc. Combust. Inst.
1540-7489,
31
, pp.
3197
3205
.
14.
Färber
,
J.
,
Koch
,
R.
,
Bauer
,
H. -J.
,
Krebs
,
W.
, and
Hase
,
M.
, 2008, “
The Effects of Piloting and Liner Boundary Conditions on Flame Locations and Stability Margins of an Industrial Size Premixed Flame
,”
Proceedings of the Eighth European Conference on Industrial Furnaces and Boilers
, Villamoura, Portugal.
15.
Schlüter
,
J.
, and
Schönfeld
,
T.
, 2000, “
LES of Jets in Cross Flow and Its Application to Gas Turbine Burners
,”
Flow, Turbul. Combust.
1386-6184,
65
(
2
), pp.
177
203
.
16.
Schildmacher
,
K. -U.
and
Koch
,
R.
, 2003, “
Experimental Investigations of the Interaction of Unsteady Flow With Combustion
,” ASME Paper No. GT2003-38644.
17.
Schulz
,
A.
,
Wittig
,
S.
, and
Martiny
,
M.
, 2000, “
Effusion Cooled Combustor Liners of Gas Turbines—An Assessment of the Contributions of Convective, Impingement, and Film Cooling
,”
Proceedings of the Symposium on Energy Engineering in the 21st Century (SEE2000)
, Vol.
1
.
18.
Albrecht
,
H.
,
Borys
,
M.
,
Damaschke
,
N.
, and
Tropea
,
C.
, 2003,
Laser Doppler and Phase Doppler Measurement Techniques
,
Springer
,
Berlin, Heidelberg
.
19.
Melling
,
A.
, 1997, “
Tracer Particles and Seeding for Particle Image Velocimetry
,”
Meas. Sci. Technol.
0957-0233,
8
, pp.
1406
1416
.
You do not currently have access to this content.