Compositional Effects on Sooting Tendencies of Diesel Surrogate Fuels with Four Components
Compositional Effects on Sooting Tendencies of Diesel Surrogate Fuels with Four Components
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四种成分对柴油替代燃料烟灰倾向的影响
DOI：
10.1021/acs.energyfuels.0c00872
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发表时间：
2020-07-16
期刊：
影响因子：
5.3
通讯作者：
Huang, Zhen
中科院分区：
文献类型：
--
作者：
Gao, Zhan;Cheng, Xiaogang;Huang, Zhen
系统地研究了掺入不同替代物的同向流动甲烷/空气扩散火焰中燃料组成对烟尘倾向的影响。测试替代燃料是柴油替代调色板中四种成分的混合物。利用激光诱导白炽灯(LII)技术获得了二维碳烟体积分数分布。实验获得了与设备无关的产烟指数(YSI)。对YSI数据和碳烟体积分数分布的分析表明，烷烃的支化度对YSI值没有明显的影响，而芳烃的加入对试验火焰的碳黑倾向有很大的促进作用。此外，可以推测，芳烃含量的增加主要影响碳烟的起始步骤，而对HACA(H-抽象-C2H2-加成)途径或多环芳烃(PAH)缩合的影响可以忽略不计。使用半尾化学动力学模型进行了模拟工作，以深入了解组成对多环芳烃形成的影响。模拟结果表明，随着1-甲基萘摩尔分数的增加，生成小分子多环芳烃的直接途径明显加强，并逐渐成为主导途径，促进了多环芳烃的生长和碳烟的形成，最终增强了多环芳烃的生成趋势。此外，本工作还可以为使用YSI作为燃料特性之一的特定碳烟倾向的柴油替代物配方提供指导。
Systematic investigations of the effects of fuel compositions on sooting tendencies were performed in co-flow methane/air diffusion flames doped with different surrogate blends. Test surrogate fuels were blends of four components in the diesel surrogate palette. The laser-induced incandescence (LII) technique was applied to obtain the 2D soot volume fraction distributions. An apparatus-independent yield sooting index (YSI) was acquired experimentally. Analysis of YSI data and the soot volume fraction distributions reveals that the branching degree of alkanes did not have an obvious effect on YSI values while the addition of the aromatics provided a tremendous promoting effect on sooting tendencies of test flames. Besides, it could be speculated that increasing aromatic content dominantly contributes to the soot inception step and has a negligible effect on the HACA (H-abstraction-C2H2-addition) pathway or polycyclic aromatic hydrocarbon (PAH) condensation. Simulation works using a semidetailed chemical kinetic model were performed to get insight into the compositional effects on PAH formation. Simulation results showed that as the mole fraction of 1-methylnaphthalene increased, more direct pathways to form small PAHs were obviously strengthened and became dominant step by step, promoting subsequent growth of PAHs and soot inception and eventually enhancing the sooting tendencies. Furthermore, this work can provide guidance for diesel surrogate formulation of a particular sooting tendency using YSI as one of the fuel characteristics.