乙烯-正庚烷混合燃料在碳烟生成中的协同效应

发布时间：2019-04-26 18:44

【摘要】：在对冲扩散火焰中对乙烯-正庚烷混合燃料的燃烧进行了模拟研究.耦合的反应机理包含正庚烷的裂解、C0-C4核心小分子反应、初始苯环生成、拓展到六苯并苯(A7)的PAH化学和包含36步成核反应的碳烟表面机理.在预混火焰中对正庚烷的燃烧进行了模拟,得到的关键组分的浓度变化与文献中的试验数据吻合较好.在对冲扩散火焰中对乙烯-正庚烷掺混燃料的燃烧进行模拟,结果显示:随着正庚烷掺混比的增加,碳烟体积分数(SVF)、苯及PAH的峰值均呈现先增加后降低的趋势,当掺混比为5%,时,SVF的峰值达到最大.对苯的生成进行详细分析,发现丙基和甲基在这种协同效应中起着关键作用.此外,随着掺混比的增加,苯与PAH的反应生成区逐渐往氧化剂侧移动,越过滞止平面后苯的生成率和消耗率均大大降低.
[Abstract]:The combustion of ethylene-n-heptane mixed fuel was simulated in the flame of hedged diffusion. The coupling reaction mechanism includes the cracking of n-heptane, the core small molecule reaction of C0-C4, the formation of initial benzene ring, extending to the PAH chemistry of hexabenzobenzene (A7) and the surface mechanism of soot containing 36-step nucleating reaction. The combustion of n-heptane in premixed flame was simulated. The concentration variation of the key components was in good agreement with the experimental data in the literature. The combustion of ethylene-n-heptane blended fuel was simulated in a diffusion flame. The results showed that the peak values of (SVF), benzene and PAH increased first and then decreased with the increase of n-heptane ratio. When the blending ratio is 5%, the peak value of SVF reaches the maximum. The formation of benzene was analyzed in detail and it was found that propyl and methyl played a key role in this synergistic effect. In addition, with the increase of the mixing ratio, the reaction formation region of benzene and PAH moves gradually to the oxidant side, and the formation rate and consumption rate of benzene decrease greatly after crossing the stagnation plane.
【作者单位】：华中科技大学能源与动力工程学院;
【基金】：国家自然科学基金资助项目(51576083)
【分类号】：TK407.9

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