It is known that many of the previously published global methane oxidation mechanisms used in conjunction with computational fluid dynamics (CFD) codes do not accurately predict CH4 and CO concentrations under typical lean-premixed combustion turbine operating conditions. In an effort to improve the accuracy of the global oxidation mechanism under these conditions, an optimization method for selectively adjusting the reaction rate parameters of the global mechanisms (e.g., pre-exponential factor, activation temperature, and species concentration exponents) using chemical reactor modeling is developed herein. Traditional global mechanisms involve only hydrocarbon oxidation; that is, they do not allow for the prediction of NO directly from the kinetic mechanism. In this work, a two-step global mechanism for NO formation is proposed to be used in combination with a three-step oxidation mechanism. The resulting five-step global mechanism can be used with CFD codes to predict CO, CO2, and NO emission directly. Results of the global mechanism optimization method are shown for a pressure of 1 atmosphere and for pressures of interest for gas turbine engines. CFD results showing predicted CO and NO emissions using the five-step global mechanism developed for elevated pressures are presented and compared to measured data.

1.
Dryer, F. L., and Glassman, I., 1973, Proceedings, Fourteenth Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA, p. 987.
2.
DuPont
V.
,
Pourkashanian
M.
, and
Williams
A.
,
1993
, “
Modeling of Process Heaters Fired by Natural Gas
,”
Journ. of the Inst. of Energy
, Vol.
66
, p.
20
20
.
3.
Gosman, D., 1996, STAR*CD Version 2.3 Users Manual, Computational Dynamics, London, England.
4.
GRI MECH 2.11, 1995, World Wide Web Site: “http://www.me.berkeley.edu/gri_mech/”.
5.
Hamer, A. J., and Roby, R. J., 1997, “CFD Modeling of a Gas Turbine Combustor Using Reduced Chemical Kinetic Mechanisms,” AIAA Paper No. 97-3242.
6.
Jones
W. P.
, and
Lindstedt
R. P.
,
1988
,
Combust. and Flame
, Vol.
73
, p.
233
233
.
7.
Mellor, A. M., ed., 1996, NOx and CO Emissions Models for Gas-Fired, Lean Premixed Combustion Turbines: Final Report, Vanderbilt University, Nashville, TN.
8.
Miller
J. A.
, and
Bowman
C. T.
,
1987
, “
Mechanism and Modeling of Nitrogen Chemistry in Combustion
,”
Prog. in Energy and Combust. Science
, Vol.
15
, p.
287
287
.
9.
Mori, G., 1998, Personal Correspondence with Ansaldo Ricerche.
10.
Nicol, D. G., 1995, “A Chemical and Numerical Study of NOx and Pollutant Formation in Low-Emissions Combustion,” PhD dissertation, University of Washington, St. Louis, MO.
11.
Nicol, D. G., Rutar, T., Martin, S. M., Malte, P. C., and Pratt, D. T., 1997, “Chemical Reactor Modeling Applied to the Production of Pollutant Emission in LP Combustors,” AIAA Paper No. 97-2711.
12.
Nicol
D. G.
,
Steele
R. C.
,
Marinov
N. M.
, and
Malte
P. C.
,
1995
, “
The Importance of the Nitrous Oxide Pathway to NOx in Lean-Premixed Combustion
,”
ASME JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER
, Vol.
117
, p.
100
100
.
13.
Steele
R. C.
,
Malte
P. C.
,
Nicol
D. G.
, and
Kramlich
J. C.
,
1995
,
Combust. and Flame
, Vol.
100
, p.
440
440
.
14.
Steele
R. C.
,
Jarrett
A. C.
,
Malte
P. C.
,
Tonouchi
J. H.
, and
Nicol
D. G.
,
1997
,
ASME JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER
, Vol.
119
, p.
102
102
.
15.
Tonouchi, J. H., 1996, “Macromixing and Micromixing in Lean Premixed Combustion,” PhD dissertation, University of Washington, St. Louis, MO.
16.
Westbrook
C. K.
, and
Dryer
F. L.
,
1984
, “
Chemical Kinetic Modeling of Hydrocarbon Combustion
,”
Prog. in Energy and Combust. Science
, Vol.
10
, p.
1
1
.
This content is only available via PDF.
You do not currently have access to this content.