Investigation of the effect of hydrogen addition on soot and PAH formation in ethylene inverse diffusion flames by combined LII and PAH LIF
Investigation of the effect of hydrogen addition on soot and PAH formation in ethylene inverse diffusion flames by combined LII and PAH LIF
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DOI：
10.1016/j.fuel.2023.130613
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发表时间：
2024-04
期刊：
影响因子：
7.4
通讯作者：
Chinonso Ezenwajiaku;Robert Roy;M. Talibi;R. Balachandran;Iain S. Burns
中科院分区：
文献类型：
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作者：
Chinonso Ezenwajiaku;Robert Roy;M. Talibi;R. Balachandran;Iain S. Burns
结果表明，在乙烯-空气反扩散火焰中加入氢气（体积分数分别为3%、6%和9%），激光诱导碳烟白炽（LII）和激光诱导多环芳烃荧光（LIF）信号均随氢气加入量的增加而减弱.研究了IDF的结构对碳烟氧化的抑制作用以及在此条件下添加氢气的效果。实验进行了使用倍频，脉冲染料激光器进行平面LIF的PAH，和脉冲光纤激光器进行LII。相对而言，LII信号比PAH LIF信号下降得更快。这将是一致的依赖性的烟尘开始对PAH浓度，以及通过减少浓度的PAH和可能的其他前体，如乙炔的烟尘生长的抑制。在燃烧器上方的高度范围处观察到相对信号减小的类似趋势，尽管测量位置包含宽范围的绝对信号水平。作为比较，还研究了以相同体积分数向IDF中添加甲烷的影响，发现其抑制PAH LIF和LII信号，但程度远小于氢的情况。
It is shown that signals from both laser-induced incandescence (LII) of soot and laser-induced fluorescence (LIF) of polycyclic aromatic hydrocarbons (PAHs) decrease with hydrogen addition (in volume fractions of 3%, 6% and 9% with respect to the fuel mixture) to ethylene–air inverse diffusion flames (IDFs). The structure of the IDF suppresses soot oxidation and the effect of hydrogen addition under these conditions has been studied. Experiments were performed using a frequency-doubled, pulsed dye laser to perform planar LIF of PAH, and a pulsed fibre laser to perform LII. In relative terms, the LII signal decreases more sharply than the PAH LIF signal. This would be consistent with the dependence of soot inception on PAH concentration as well as the suppression of soot growth via the reduced concentration of PAH and perhaps other precursors such as acetylene. Similar trends in relative signal decrease are observed at a range of heights above the burner, despite the measurement locations encompassing a wide range of absolute signal levels. As a comparison, the influence of adding methane to the IDF in the same volume fractions was also studied and found to suppress PAH LIF and LII signals but to a far lesser extent than in the case of hydrogen.