Numerical investigation of the hybrid pulse–DC plasma assisted ignition and NO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si10.svg"><mml:msub><mml:mrow/><mml:mi>x</mml:mi></mml:msub></mml:math> emission of NH<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"><mml:msub><mml:mrow/><mml:mn>3</mml:mn></mml:msub></mml:math>/N<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub></mml:math>/O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub></mml:math> mixture
Yifan Qiu, Yifei Zhu, Yun Wu, Ningqiu Zhao, Zhenyang Li, Mai Hao, Boya Zhang, Di Pan
Abstract
The ignition delay and NO emission characteristics of the NH 3 /N 2 /O 2 mixture under the influence of pulse–DC hybrid plasma discharges have been studied. The plasma and combustion chemistry mechanisms for NH 3 /N 2 /O 2 mixture are reviewed, an improved kinetics mechanism is proposed with a well validated electron scattering cross section data. An improved coupled plasma and combustion chemistry code allowing sensitivity/pathway analysis is developed. The role of key species on the ignition delay time and the effects of low E/N discharge over long periods of time (DC stage) on NO x emission are studied. The results show that, NO emission will be strongly enhanced due to the increased HNO, NH and N density in NH 3 containing mixtures in the DC stage, NO density increases with the E/N value in DC stage due to the reduction of NH and NH 2 species. The role of O 2 ( a 1 Δ g ) in promoting ignition was studied using different rate constant of O 2 ( a 1 Δ g ) + NO → O 2 + NO : O 2 ( a 1 Δ g ) mainly reacts with H 2 and H to produce radicals such as O, H and OH instead of quenched by NO. The vibrationally excited NH 3 (v2) molecule plays the dominating role in heat release through V–T relaxation with NH 3 .