Premium
Dilution effect of air stream on NO emission characteristic in H 2 /Ar counterflow diffusion flame
Author(s) -
Park Jeong,
Lee KyungHwan,
Kim KiSeong
Publication year - 2002
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.796
Subject(s) - dilution , diluent , chemistry , diffusion , volume (thermodynamics) , adiabatic flame temperature , hydrogen , analytical chemistry (journal) , diffusion flame , thermodynamics , radiative transfer , combustion , organic chemistry , optics , combustor , physics
The dilution effect of air stream according to agent type on flame structure and NO emission behaviour is numerically analysed with detailed chemistry. The adopted fuel is hydrogen diluted with the argon of volume percentage 50 per cent and the volume percentage of diluents (H 2 O, CO 2 and N 2 ) in air stream is systematically changed from 10 to 50. The radiative heat loss term, based on an optically thin model, is included to clearly describe the flame structure and NO emission behaviour, especially at low strain rates. The effect of dilution of air stream on the decrease of maximum flame temperature varies as CO 2 >H 2 O>N 2 . The qualitative tendency of the numerically predicted mole fractions of H, O and OH is well described using a simplified formula, based on a partial equilibrium concept. It is seen that the H 2 O addition to air stream is the most effective for reducing NO emission. In the case of the addition of H 2 O and N 2 the NO emission behaviour is governed by the thermal effect and in the case of CO 2 addition it is governed by both the thermal effect and the chemical effect. But the chemical effect, which is mainly attributed by the Fenimore mechanism to the breakdown of CO 2 , is much more predominant in comparison with the thermal effect. Copyright © 2002 John Wiley & Sons, Ltd.