TY - JOUR
T1 - Chemical structure of premixed ammonia/hydrogen flames at elevated pressures
AU - Osipova, K.N.
AU - Sarathy, Mani
AU - Korobeinichev, O.P.
AU - Shmakov, Andrey G.
N1 - KAUST Repository Item: Exported on 2022-10-18
Acknowledgements: This work was supported by the Ministry of Science and Higher Education of the Russian Federation (Project No: 075-15-2020-806)
PY - 2022/10/13
Y1 - 2022/10/13
N2 - Because it is a carbon free fuel with high volumetric and gravimetric hydrogen density, ammonia is considered to be a promising hydrogen carrier molecule; its combustion chemistry, consisting of ammonia and ammonia/hydrogen blends, are of great importance in engine and gas turbine systems. This paper presents experimental data and kinetic modeling of the structure of NH3/H2/O2/Ar premixed flames at elevated pressures. Equivalence ratios were maintained at 0.8, 1.0 and 1.2, and the NH3/H2 ratio was 1:1 (molar ratio). Experiments were performed at pressures of 4 and 6 atm. Eight recently published chemical-kinetic mechanisms of ammonia combustion and oxidation were applied to numerically simulate flame structure. Experimental and numerical data showed that the main nitrogen containing compounds in the post flame zone were N2 and NO, while the concentrations of N2O and NO2 were negligible. In terms of NO emissions reduction, it was revealed that rich conditions were more effective. At the same time, pressure increases resulted in decreasing NO concentration in the post flame zone, as well as lower maximum concentration of NO and N2O. Numerical analysis showed that N2O and NO2 were formed mainly from NO. To improve the agreement between experimental and numerical data, rate kinetic parameters of these reactions should be refined.
AB - Because it is a carbon free fuel with high volumetric and gravimetric hydrogen density, ammonia is considered to be a promising hydrogen carrier molecule; its combustion chemistry, consisting of ammonia and ammonia/hydrogen blends, are of great importance in engine and gas turbine systems. This paper presents experimental data and kinetic modeling of the structure of NH3/H2/O2/Ar premixed flames at elevated pressures. Equivalence ratios were maintained at 0.8, 1.0 and 1.2, and the NH3/H2 ratio was 1:1 (molar ratio). Experiments were performed at pressures of 4 and 6 atm. Eight recently published chemical-kinetic mechanisms of ammonia combustion and oxidation were applied to numerically simulate flame structure. Experimental and numerical data showed that the main nitrogen containing compounds in the post flame zone were N2 and NO, while the concentrations of N2O and NO2 were negligible. In terms of NO emissions reduction, it was revealed that rich conditions were more effective. At the same time, pressure increases resulted in decreasing NO concentration in the post flame zone, as well as lower maximum concentration of NO and N2O. Numerical analysis showed that N2O and NO2 were formed mainly from NO. To improve the agreement between experimental and numerical data, rate kinetic parameters of these reactions should be refined.
UR - http://hdl.handle.net/10754/683509
UR - https://linkinghub.elsevier.com/retrieve/pii/S0010218022004369
U2 - 10.1016/j.combustflame.2022.112419
DO - 10.1016/j.combustflame.2022.112419
M3 - Article
SN - 0010-2180
VL - 246
SP - 112419
JO - Combustion and Flame
JF - Combustion and Flame
ER -