论文部分内容阅读
在模型燃烧室中通过变化合成气的成分比例研究不同燃料对点火时间和点火边界的影响。实验所用合成气由氢气、一氧化碳、甲烷、二氧化碳和氮气组成,热值范围4.76~35.8MJ/m3,同时用甲烷作为对照组。实验中研究了不同来流空气流量、燃料组成对点火时间、点火范围的影响。结果表明随着氢气体积含量从0增加到20%时,点火时间会显著降低,点火范围扩大显著。当氢气含量超过50%时,实验条件下的空气流量对点火时间和点火下限的影响不再明显。与此同时,实验中检测到3种不同形态的后续火焰。接近点火下限的不稳定火焰;贫燃条件下的稳定火焰;富燃条件下表现为周期性的向上、下游传播的振荡火焰。通过分析上述结果得到了合成气随当量比和氢含量变化的点火工况图。
The effects of different fuels on ignition time and ignition boundary were studied by varying the proportions of the syngas in the model combustor. The syngas used in the experiment consisted of hydrogen, carbon monoxide, methane, carbon dioxide and nitrogen with a heating value ranging from 4.76 to 35.8 MJ / m3, using methane as the control. In the experiment, the effects of different incoming air flow, fuel composition on ignition time and ignition range were studied. The results show that as the hydrogen content increases from 0 to 20%, the ignition time decreases significantly and the ignition range expands significantly. When the hydrogen content exceeds 50%, the influence of the air flow under the experimental conditions on the ignition time and ignition limit is no longer obvious. In the meantime, three different types of subsequent flames were detected in the experiment. An unstable flame near the lower ignition limit; a steady flame under lean combustion conditions; a periodic flame propagating upward and downstream under rich conditions. By analyzing the above results, the ignition condition diagram of syngas with equivalence ratio and hydrogen content was obtained.