Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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A Study of NO Fmission Characteristics in a Non-premixed Counterflow Flame with $H_2/CO_2/Ar$ Blended-fuel

수소/이산화탄소/알곤 혼합 연료의 비예혼합 대향류 화염에서 NO 배출 특성 연구

  • Lee, Kee-Man (School of Mechanical and Aerospace Engineering, Sunchon National University)
  • 이기만 (순천대학교 기계우주항공공학부)
  • Published : 2007.07.01
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Abstract

The detailed chemistry with reaction mechanism of GRI 2.11, which consists of 49 species and 279 elementary reactions, have been numerically conducted to investigate the flame structure and NO emission characteristics in a non-premixed counterflow flame of blended fuel of $H_2/CO_2/Ar$. The combination of $H_2,\;CO_2$, and Ar as fuel is selected to clearly display the contribution of hydrocarbon products to flame structure and NO emission characteristics due to the breakdown of $CO_2$. Radiative heat loss term is involved to correctly describe the flame dynamics especially at low strain rates. All mechanisms including thermal, $NO_2,\;N_2O$, and Fenimore are also taken into account to separately evaluate the effects of $CO_2$ addition on NO emission characteristics. The increase of added $CO_2$ quantity causes flame temperature to fall since at high strain rates diluent effect is prevailing and at low strain rates the breakdown of $CO_2$ produces relatively populous hydrocarbon products and thus the existence of hydrocarbon products inhibits chain branching. It is also found that the ratio of the contribution by Fenimore mechanism to that by thermal mechanism in the total mole production rate becomes much larger with increase in the $CO_2$ quantity and strain rate, even though the absolute quantity of NO production is deceased. Consequently, as strain rate and $CO_2$ quantity increase, NO production by Fenimore mechanism is remarkably augmented.

Keywords

References

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