The effects of the three fuel-side diluents N2, CO2, and H2O on the accurate flame structure and NOx formation characteristics of the turbulent syngas nonpremixed flames are investigated using the one-dimensional-turbulence (ODT) model. For nonpremixed flames, the fuel mixtures consist of H2, CO and three diluents: N2, H2O, and CO2. The proportion of diluents is varied from 10% to 30% while the H2/CO ratio is kept as a constant at 0.75 all the time. Mass fraction of main species and temperature of 30% N2 basic dilution case predicted by the ODT model are compared with the tests measuring results obtained by International Workshop on Measurements and Computation of Turbulent Nonpremixed Flames, and it is found that the results are in good agreement. Numerical results indicate that the CO2 diluted flames have the largest reduction on flame temperature as well as the NOx emission, while H2O is more effective than N2. For CO2 and H2O dilution flames, flame structure becomes unstable with an obvious lift phenomenon. Since ODT captures the flame extinction process, flames added with CO2 and H2O not only have a lower extinction temperature but also the reignition process is slower.

References

1.
Shilling
,
N. Z.
, and
D. T.
,
Lee
,
2003
, “
IGCC-Clean Power Generation Alternative for Solid Fuels
,” PowerGen Asia, Ho Chi Minh City, Vietnam, September 23–25.
2.
Brdar
,
R. D.
, and
Jones
,
R. M.
,
2000
, “
GE IGCC Technology and Experience With Advanced Gas Turbines
,”
GE Power Systems
,
Schenectady, NY
, Paper No. GER-4207.
3.
Ge
,
B.
,
Zang
,
S.
,
Guo
,
P.
, and
Tian
,
Y.
,
2012
, “
Experimental Investigation of Double-Swirled Non-Premixed Syngas Flames by Planar Laser-Induced Fluorescence
,”
Energy Fuels
,
26
(
3
), pp.
1585
1591
.10.1021/ef201814v
4.
Rørtveit
,
G. J.
,
Hustad
,
J. E.
,
Li
,
S. C.
, and
Williams
,
F. A.
,
2002
, “
Effects of Diluents on NOx Formation in Hydrogen Counterflow Flames
,”
Combust. Flame
,
130
(
1
), pp.
48
61
.10.1016/S0010-2180(02)00362-0
5.
Park
,
J.
,
Kim
,
S.
,
Keel
,
S. I.
,
Noh
,
D. S.
,
Oh
,
C. B.
, and
Chung
,
D.
,
2004
, “
Effect of Steam Addition on Flame Structure and NO Formation in H2–O2–N2 Diffusion Flame
,”
Int. J. Energy Res.
,
28
(
12
), pp.
1075
1088
.10.1002/er.1016
6.
Rørtveit
,
G. J.
,
Hustad
,
J. E.
, and
Williams
,
F. A.
,
2001
, “
NOx Formation in Diluted CH4/H2 Counterflow Diffusion Flames
,”
Sixth International Conference on Technologies and Combustion for a Clean Environment
, Porto, Portugal, July 9–12.
7.
Giles
,
D. E.
,
Som
,
S.
, and
Aggarwal
,
S. K.
,
2006
, “
NOx Emission Characteristics of Counterflow Syngas Diffusion Flames With Airstream Dilution
,”
Fuel
,
85
(
12
), pp.
1729
1742
.10.1016/j.fuel.2006.01.027
8.
Kim
,
S. G.
,
Park
,
J.
, and
Keel
,
S. I.
,
2002
, “
Thermal and Chemical Contributions of Added H2O and CO2 to Major Flame Structures and NO Emission Characteristics in H2/N2 Laminar Diffusion Flame
,”
Int. J. Energy Res.
,
26
(
12
), pp.
1073
1086
.10.1002/er.837
9.
Gabriel
,
R.
,
Navedo
,
J. E.
, and
Chen
,
R. H.
,
2000
, “
Effects of Fuel Lewis Number on Nitric Oxide Emission of Diluted H2 Turbulent Jet Diffusion Flames
,”
Combust. Flame
,
121
(
3
), pp.
525
534
.10.1016/S0010-2180(99)00159-5
10.
Alavandi
,
S. K.
, and
Agrawal
,
A. K.
,
2005
, “
Lean Premixed Combustion of Carbon Monoxide-Hydrogen-Methane Fuel Mixtures Using Porous Inert Media
,”
ASME
Paper No. GT2005-68586.10.1115/GT2005-68586
11.
Zhang
,
Y.
,
Yang
,
T.
,
Liu
,
X.
,
Tian
,
L.
,
Fu
,
Z.
, and
Zhang
,
K.
,
2012
, “
Reduction of Emissions From a Syngas Flame Using Micromixing and Dilution With CO2
,”
Energy Fuels
,
26
(
11
), pp.
6595
6601
.10.1021/ef300751d
12.
Lee
,
M. C.
,
Seo
,
S. B.
,
Yoon
,
J.
,
Kim
,
M.
, and
Yoon
,
Y.
,
2012
, “
Experimental Study on the Effect of N2, CO2, and Steam Dilution on the Combustion Performance of H2 and CO Synthetic Gas in an Industrial Gas Turbine
,”
Fuel
,
102
, pp.
431
438
.10.1016/j.fuel.2012.05.028
13.
Weiland
,
N., T.
, and
Strakey
,
P. A.
,
2010
, “
NOx Reduction by Air-Side Versus Fuel-Side Dilution in Hydrogen Diffusion Flame Combustors
,”
ASME J. Gas Turbines Power
,
132
(
7
), p. 071504.10.1115/1.4000268
14.
Samanta
,
A.
, and
Ganguly
,
R.
,
2010
, “
Effect of CO2 Dilution on Flame Structure and Soot and NO Formations in CH4-Air Nonpremixed Flames
,”
ASME J. Gas Turbines Power
,
132
(12), p. 124501.10.1115/1.4001809
15.
DLR–Institut fur Verbrennungstechnik, 2013, “Documentation,” http://www.dlr.de/vt/desktopdefault.aspx/tabid-3067/4635_read-6732/
16.
Cha
,
C. M.
, and
Pitsch
,
H.
,
2002
, “
Higher-Order Conditional Moment Closure Modelling of Local Extinction and Reignition in Turbulent Combustion
,”
Combust. Theory Modell.
,
6
(
3
), pp.
425
437
.10.1088/1364-7830/6/3/303
17.
Im
,
H. G.
,
Chen
,
J. H.
, and
Law
,
C. K.
,
1998
, “
Ignition of Hydrogen-Air Mixing Layer in Turbulent Flows
,”
Symp. (Int.) Combust.
, 27(1), pp.
1047
1056
.10.1016/S0082-0784(98)80505-5
18.
Katta
, V
. R.
,
Hsu
,
K. Y.
, and
Roquemore
,
W. M.
,
1998
, “
Local Extinction in an Unsteady Methane-Air Jet Diffusion Flame
,”
Symp. (Int.) Combust.
,
27
(1), pp.
1121
1129
.10.1016/S0082-0784(98)80514-6
19.
Kronenburg
,
A.
, and
Kostka
,
M.
,
2005
, “
Modeling Extinction and Reignition in Turbulent Flames
,”
Combust. Flame
,
143
(
4
), pp.
342
356
.10.1016/j.combustflame.2005.08.021
20.
Kerstein
,
A. R.
,
1988
, “
A Linear-Eddy Model of Turbulent Scalar Transport and Mixing
,”
Combust. Sci. Technol.
,
60
(
4–6
), pp.
391
421
.10.1080/00102208808923995
21.
Kerstein
,
A. R.
,
1999
, “
One-Dimensional Turbulence: Model Formulation and Application to Homogeneous Turbulence, Shear Flows, and Buoyant Stratified Flows
,”
J. Fluid Mech.
,
392
(
1
), pp.
277
334
.10.1017/S0022112099005376
22.
McDermott
,
R. J.
,
2005
, “
Toward One-Dimensional Turbulence Subgrid Closure for Large-Eddy Simulation
,” Ph.D. dissertation, The University of Utah, Salt Lake City, UT.
23.
Kalos
,
M. H.
, and
Whitlock
,
P. A.
,
1996
,
Monte Carlo Methods
,
Wiley
,
New York
.
24.
Kee
,
R. J.
,
Rupley
,
F. M.
, and
Miller
,
J. A.
,
1989
,
“Chemkin-II: A Fortran Chemical Kinetics Package for the Analysis of Gas-Phase Chemical Kinetics
,”
Sandia National Laboratories
,
Livermore, CA
.
25.
Kee
,
R. J.
,
Dixon-Lewis
,
G.
,
Warnatz
,
J.
,
Coltrin
,
M. E.
, and
Miller
,
J. A.
,
1986
,
“A Fortran Computer Code Package For The Evaluation of Gas-Phase Multicomponent Transport Properties
,”
Sandia National Laboratories
,
Livermore, CA
.
26.
Drake
,
M. C.
, and
Blint
,
R. J.
,
1991
, “
Relative Importance of Nitric Oxide Formation Mechanisms in Laminar Opposed-Flow Diffusion Flames
,”
Combust. Flame
,
83
(
1
), pp.
185
203
.10.1016/0010-2180(91)90212-T
You do not currently have access to this content.