Soot precursor measurements in benzene and hexane diffusion flames
Soot precursor measurements in benzene and hexane diffusion flames
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DOI：
10.1016/j.combustflame.2008.03.022
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发表时间：
2008-08
影响因子：
4.4
通讯作者：
Y. Kobayashi;T. Furuhata;K. Amagai;M. Arai
中科院分区：
文献类型：
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作者：
Y. Kobayashi;T. Furuhata;K. Amagai;M. Arai
为了阐明液体燃料扩散火焰中烟灰形成的机制，对烟灰及其前体进行了测量。为此目的，使用了由小型池燃烧设备系统形成的烟灰扩散火焰。苯和己烷被用作典型的芳烃和石蜡燃料。使用激光诱导荧光（LIF）方法获得多环芳烃（PAH）的空间分布，多环芳烃被视为烟灰颗粒。通过激光诱导白炽 (LII) 方法测量测试火焰中烟灰的空间分布。烟灰直径是根据 LII 强度的时间变化来估计的。根据 LIF 和 LII 的结果定义了从 PAH 到烟灰的过渡区域。研究了苯和己烷火焰的火焰温度、多环芳烃种类和过渡区域的烟灰直径。结果表明，虽然苯和己烷的火焰结构不同，但苯火焰的PAHs-烟灰转变区的温度与己烷火焰相似。此外，还讨论了两种火焰中气相色谱法测量的 PAH 浓度与 LIF 获得的 PAH 分布之间的关系。研究发现，苯和甲苯等分子量较小的多环芳烃保留在多环芳烃-烟灰过渡区和烟灰区域，并且认为比芘重的分子是烟灰前体形成的主要候选者。
To clarify the mechanism of soot formation in diffusion flames of liquid fuels, measurements of soot and its precursors were carried out. Sooting diffusion flames formed by a small pool combustion equipment system were used for this purpose. Benzene and hexane were used as typical aromatic and paraffin fuels. A laser-induced fluorescence (LIF) method was used to obtain spatial distributions of polycyclic aromatic hydrocarbons (PAHs), which are considered as soot particles. Spatial distributions of soot in test flames were measured by a laser-induced incandescence (LII) method. Soot diameter was estimated from the temporal change of LII intensity. A region of transition from PAHs to soot was defined from the results of LIF and LII. Flame temperatures, PAH species, and soot diameters in this transition region were investigated for both benzene and hexane flames. The results show that though the flame structures of benzene and hexane were different, the temperature in the PAHs–soot transition region of the benzene flame was similar to that of the hexane flame. Furthermore, the relationship between the PAH concentrations measured by gas chromatography in both flames and the PAH distributions obtained from LIF are discussed. It was found that PAHs with smaller molecular mass, such as benzene and toluene, remained in both the PAHs–soot transition and sooting regions, and it is thought that molecules heavier than pyrene are the leading candidates for soot precursor formation.