Numerical evaluation of NOx mechanisms in methane-air counterflow premixed flames
Numerical evaluation of NOx mechanisms in methane-air counterflow premixed flames
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DOI：
10.1007/s12206-008-1222-y
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发表时间：
2009-03-01
影响因子：
1.6
通讯作者：
Chung, Suk Ho
中科院分区：
文献类型：
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作者：
Cho, Eun-Seong;Chung, Suk Ho
氮氧化物 (NOx) 的控制一直是燃烧系统设计中的一个主要问题，因为氮氧化物 (NOx) 在臭氧消耗和光化学烟雾的产生中起着关键作用。 NOx 排放的特性对于开发具有合适的减排方法的清洁燃烧器来说是重要的信息。在本研究中，对氮氧化物排放特性进行了数值评估，考虑了当量比、拉伸速率、压力和初始温度的影响。一般来说，NOx排放峰值出现在单位情况当量比附近，并且由于NOx机制的温度敏感性，NOx排放随着压力和初始温度的增加而增加。由于高温区停留时间的减少，NOx随着拉伸率的增加而降低。此外，还用两种计算方法的当量比评估了热机制和瞬发机制。传统方法忽略了热力和瞬发NOx耦合机制的相互作用。引入反应路径图以了解各种条件下的有效反应路径。
The control of nitrogen oxides (NOx) has been a major issue in designing combustion systems, since NOx play a key role in ozone depletion and the generation of photochemical smog. The characteristics of NOx emission can be essential information for the development of a clean combustor having suitable reduction methodologies. In the present study, NOx emission characteristics were evaluated numerically, accounting for the effect of equivalence ratio, stretch rate, pressure, and initial temperature. In general, peak NOx emission appeared near the equivalence ratio of unity case, and NOx emission increased with pressure and initial temperature due to the temperature sensitivity in NOx mechanism. NOx decreased with stretch rate due to the decrease in residence time in high temperature region. Furthermore, the thermal and prompt mechanisms were evaluated with equivalence ratio for two calculation methods. The conventional methods ignore the interaction of coupled mechanism of thermal and prompt NOx. The reaction path diagram was introduced to understand effective reaction pathways in various conditions.