Experimental study of the effect of C8 oxygenates on sooting processes in high pressure spray flames
Experimental study of the effect of C8 oxygenates on sooting processes in high pressure spray flames
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DOI：
10.1016/j.combustflame.2020.06.015
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发表时间：
2020-10-01
影响因子：
4.4
通讯作者：
Ganippa, Lionel
中科院分区：
文献类型：
--
作者：
Ruiz-Rodriguez, Irene;Cracknell, Roger;Ganippa, Lionel
含氧化合物具有减少烟尘排放和提高发动机燃烧效率的能力。大多数研究都集中在短碳链氧合物的减灰潜力上，而长碳链氧合物的探索相对较少。在这项工作中，研究了具有与柴油相似的热物理和化学性质的长碳链氧合物，即2-辛酮（酮），1-辛醇（醇），乙酸己酯（酯）和辛醛（醛）的减灰潜力。将这些氧合物在高压下注入一个保持在高温环境条件下的定容腔中，并使用高速双色高温法系统研究它们的喷雾火焰。研究发现，与柴油相比，在相同的喷射燃料质量下，含氧化合物减少了总体煤烟。不同含氧组分之间的烟炱倾向差异不大，但小于柴油。与含氧官能团相比，不含芳香族基团和直接与碳原子结合的氧似乎对减灰有更大的影响。氧化物改变了喷雾中局部氧当量比，影响了烟尘的形成及其在火焰中的分布。在研究的高压条件下，所研究的长碳链氧合物的平均烟化倾向与醇类似，按：酯<醛的顺序增加
Oxygenated compounds have the ability to reduce soot emissions and to improve the combustion efficiency in engines. Most studies have focused on the soot reduction potential of shorter carbon chain oxygenates, whilst longer carbon chain oxygenates are still relatively unexplored. In this work, the soot reduction potential of long carbon chain oxygenates having similar thermo-physical and chemical properties to those of diesel have been studied, viz., 2-octanone (ketone), 1-octanol (alcohol), hexyl acetate (ester) and octanal (aldehyde). These oxygenates were injected at high pressure into a constant volume chamber maintained at high ambient temperature conditions, and their spray flames were investigated using a high-speed, two-colour pyrometry system. It was found that for the same injected fuel mass, the oxygenates reduced the overall soot when compared to diesel. Small differences in sooting tendencies were observed between different oxygenated moieties but these were smaller than those relative to diesel. The absence of aromatic groups and the presence of oxygen directly bonded to carbon atoms seemed to have a larger effect on soot reduction than the oxygenated functional group. The oxygenates altered the local oxygen equivalence ratio in the spray, influencing the soot formation and its distribution in the flame. Under the high pressure conditions studied, the average sooting tendency of the long carbon-chain oxygenates studied increased in the order of: ester< aldehyde similar to alcohol