Experimental study on sooting propensities of ternary blends of n-dodecane, isododecane, and C8 oxygenates at high pressures
Experimental study on sooting propensities of ternary blends of n-dodecane, isododecane, and C8 oxygenates at high pressures
复制标题
DOI：
10.1016/j.combustflame.2021.111469
复制
发表时间：
2021-09
影响因子：
4.4
通讯作者：
Irene Ruiz-Rodriguez;R. Cracknell;M. Parkes;T. Megaritis;L. Ganippa
中科院分区：
文献类型：
--
作者：
Irene Ruiz-Rodriguez;R. Cracknell;M. Parkes;T. Megaritis;L. Ganippa
液体燃料由于其高能量密度、易于操作和成熟的发动机技术，在内燃机中仍然普遍使用。与其他发电行业一样，交通运输行业也面临着减少煤烟等排放的需要。解决这个问题的一个选择是使用含氧燃料。燃料中含氧化合物的存在有可能减少重型柴油发动机和各种发电部门的烟尘排放。了解含氧化合物在高压下的基本燃烧和烟尘特性对未来低烟尘燃料的发展至关重要。在这项工作中，属于C8官能团的四种含氧化合物与正十二烷和异十二烷一起部署，形成具有相同氧含量的三元共混物，质量为2.5%，十六烷数为52。将混合物在高压下注入恒定体积的高压、高温条件下。采用高速诊断技术对火焰和烟灰的自然光度进行了研究。结果表明，混合物延迟了烟灰的首次出现。与柴油相比，含氧化合物的存在使烟尘的上升长度增加了40%，阻碍了烟尘的形成高达55%，并使氧化率提高了10%。各加氧混合物的排烟倾向依次为酮≈醇<酯<醛<柴油。两种含氧化合物的排烟倾向差异小于两种含氧化合物的排烟倾向差异，说明排烟主要是由氧含量和稀释作用造成的。然而，在氧合物之间观察到的微小差异表明，该部分确实对烟尘还原有影响，但比稀释和氧气的影响程度要小。
The use of liquid fuels in internal combustion engines is still prevalent in society because of their high energy density, ease of handling, and matured engine technology. Along with other power generation sectors, the transport sector faces the need to reduce emissions such as soot. One option to address this is to use oxygen-bearing fuels. The presence of oxygenated compounds in fuels have the potential to reduce soot emissions in heavy duty diesel engines and various power generation sectors. Understanding the fundamental combustion and sooting characteristics of oxygenated compounds at high pressures is essential for the development of future low sooting fuels. In this work, four oxygenated compounds belonging to the C8 functional group were deployed along with normal dodecane and isododecane to form ternary blends having the same oxygen content, of 2.5% by mass, and a matching cetane number of 52. The blends were injected at a high pressure into controlled high pressure, high temperature conditions in a constant volume chamber. The flame and the soot natural luminosity were investigated with high-speed diagnostics. The results revealed that the blends delayed the onset of the first appearance of soot. The presence of oxygenates increased the soot lift-off length by 40%, hindered the formation of soot by up to 55%, and enhanced the oxidation by up to 10%, all relative to diesel. The sooting tendency of the oxygenated blends increased in the order of ketone ≈ alcohol < ester < aldehyde < diesel. The difference between the sooting tendencies of the oxygenates was smaller than those between the oxygenates and diesel, showing that soot reduction was mostly due to oxygen content and dilution effects. However, the small differences observed between the oxygenates indicates that the moiety does have an effect on soot reduction—but to a lesser extent than dilution and oxygen effects.