Study on the Combustion Characteristics of Carbon Monoxide-Hydrogen-Nitrogen Mixture

一氧化碳-氢-氮混合气体燃烧特性研究

基本信息

批准号：
12650191
负责人：
NISHIOKA Makihito
金额：
$ 2.3万
依托单位：
University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650191/
关键词：
Coflow diffusion flame Carbon monoxide Hydrogen NOx Burning velocity Detailed kinetics numerical calculation Limits of flammability Flame length NO_x 火炎長さ火炎構造 NOx 素反応群

项目摘要

In this study, the combustion characteristics and the NOx emission of the CO-H_2-N_2 mixture, which can be produced by the partial oxidation of methane with air, were investigated by a numerical calculation with detailed chemical kinetics. The results were compared with those of the CH_4-N_2 mixture and H_2-N_2 mixture. In each case air was used as the oxidizer. The compositions of the above three fuel mixtures were determined so that the adiabatic flame temperatures of the stoichiometric combustion should be identical with each other. The one-dimensional premixed flame and the coflow diffusion flame were adopted respectively as the representative premixed flame and the representative diffusion flame. Experiments were also conducted for the coflow diffusion flame, and the flame structure and the NOx concentration distribution were measured and compared in detail with the numerical results. For the one-dimensional premixed flame, it was found that the burning velocity, the flammability limits and the emission index of NOx of the CO-H_2-N_2 flame are much different from those of the CH_4-N_2 flame, and similar to those of the H_2-N_2 flame. For the coflow diffusion flame, on the other hand, it was found that the temperature distribution, the flame length and the NOx emission are much different from those of the CH_4-N_2 flame, and similar to those of the H_2-N_2 flame. That is, as compared to the CH_4-N_2 flame the CO-H_2-N_2 flame has much shorter flame length and lower NOx emission. In addition, QRPD (Quantitative Reaction Path Diagram) for NO formation was drawn based on the numerical results, in order to investigate the cause of the low NOx emission of the CO-H_2-N_2 flame. As a result, it was found that NO is formed mainly via NNH and any large reaction pathway related with C such as prompt NO does not exist in the CO-H_2-N_2 flame.

在这项研究中，通过具有详细的化学动力学的数值计算，研究了Co-H_2-N_2混合物的燃烧特性和Co-H_2-N_2混合物的NOx发射，可以通过空气中的部分氧化产生。将结果与CH_4-N_2混合物和H_2-N_2混合物的结果进行了比较。在每种情况下，空气都用作氧化剂。确定上述三种燃料混合物的组成，以便化学计量燃烧的绝热火焰温度应相同。一维预定的火焰和Coflow扩散火焰分别被用作代表性的预防火焰和代表性扩散火焰。还针对Coflow扩散火焰进行了实验，并测量了火焰结构和NOX浓度分布，并将其详细比较与数值结果进行了比较。对于一维预定的火焰，发现CO-H_2-N_2火焰的燃烧速度，易燃性限制和NOX的发射指数与CH_4-N_2火焰的速度大不相同，并且与H_2-N_2火焰的火焰相似。另一方面，对于Coflow扩散火焰，发现温度分布，火焰长度和NOX发射与CH_4-N_2火焰的发射大不相同，并且与H_2-N_2火焰的发射相似。也就是说，与CH_4-N_2火焰相比，Co-H_2-N_2火焰的火焰长度和较低的NOX发射。此外，为了研究CO-H_2-N_2火焰的低NOx发射的原因，QRPD（定量反应路径图）未根据数值结果绘制任何形成。结果，发现NO主要是通过NNH形成的，并且与C的任何大型反应途径（如提示NO）相关的任何大型反应途径在Co-H_2-N_2火焰中不存在。