富氧空气/甲烷扩散燃烧的NO抑制机理的数值研究  

A Numerical Study on Reduction Methods of NO in Methane/Oxygen-enriched Air Diffusion Flame

作　　者：冯耀勋[1] 赵黛青[2] 贾明生[1] 郑晓峰[1] 

机构地区：[1]湛江海洋大学工程学院,广东湛江524025 [2]中国科学院广州能源研究所,广东广州510640

出　　处：《工业加热》2005年第5期10-13,共4页Industrial Heating

基　　金：广东省自然科学基金(032703);广州市科技计划项目(2003J1-C108).

摘　　要：为了开发适用于富氧燃烧的NO抑制技术,以对向流扩散火焰这一扩散燃烧的典型形态为对象,利用所建立的基元反应动力学模型研究了燃料稀释(CO2为稀释剂)以及速度梯度的改变对富氧空气/甲烷扩散火焰中NO生成的影响。用CO2稀释燃料甲烷得到的计算结果表明,随着燃料中CO2浓度的增大,火焰结构和NO生成的机理发生了显著变化,NO排放指数NO(EmissionindexofNO)单调减少。改变速度梯度发现,随着速度梯度的增加,热力型NO质量生成速率以及NO快速下降。这些研究表明,用CO2稀释燃料以及增加速度梯度可以减少富氧火焰中NO的生成。Since the reduction technology of NO formation has been a key factor to facilitate oxygen-enriched combustion, reduction methods of NO in oxygen-enriched air/methane diffusion flame were studied in this paper. A ounterflow diffusion flame as a basic configuration of diffusion flames was studied, and an oxygen-enriched air/methane counterflow diffusion flame was analyzed numerically using detailed chemical kinetic, for conditions that methane stream was diluted with the dilution （CO2）, the influence of velocity gradient was studied in the same time. The obtained results show that the flame structure and dominant mechanism of NO formation change greatly with the change of concentration ofdiluents in CO2, the EI NO （Emission index of NO） decreased gradually as the concentration ofdiluents CO2 was increased. The amount of thermal NO generation and the emission index of NO decrease together as the velocity gradient becomes large. Those results suggest that fuel diluted by CO2 and the large velocity gradient may reduce the NO formation in the oxygen-enriched combustion.

关 键 词：富氧燃烧 NO生成 燃料稀释 对向流扩散火焰 速度梯度 数值分析 

分 类 号：TK16[动力工程及工程热物理—热能工程]