Interference Between Cnstituents in Spontaneous Ignition and Flame Propagation of Hydrocarbons

碳氢化合物自燃和火焰传播中成分之间的干扰

基本信息

批准号：
09650239
负责人：
ISHIYAMA Takuji
金额：
$ 2.5万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650239/
关键词：
Internal Combustion Engines Fuel Hydrocarbons Oxidation Process Spontaneous Ignition Flame Propagation 火災伝播

项目摘要

The purpose of this study is to clarify fuel effects on spray ignition and ignition of premixture with attention to interference between constituents in fuels. First the change of fuel during its ignition process was investigated in chemical aspects using a gas sampling technique in a rapid compression machine and a flow reactor. The results show that the fuel breaks down to small hydrocarbons before rapid and large amount heat release begins due to temperature increase by heat supplied from adjacent initially oxidized mixture. The production rate of intermediate chemical species including the small hydrocarbons affects the ignition delay of a fuel spray.Secondly the relation between fuel-air mixing and fuel effect was discussed based on the results obtained by using a newly constructed constant volume vessel equipped with a high-pressure fuel injection system. Ignition delays and courses of pressure during ignition process were measured and examined at the injection pressure of 80-160MPa and with the nozzle hole diameter of 0.14-0.22mm. The results reveal that the fuel effect on ignition delay diminishes at the high-pressure injection case with small nozzle holes. The effect was observed only in the case of low ambient pressure in which the fuel oxidation speed is slower. It is supposed that fast temperature increase in local mixtures shortens the time necessary for accumulating small hydrocarbons due to rapid fuel-air mixing. In a certain rage of ambient temperature, straight chain saturated hydrocarbons are dominant sources to generate intermediate species, while aromatic hydrocarbons in fuels act as inactive species before ignition. This is the reason why the ignition is delayed when aromatics are added into fuels. Dependency of nominal activation energy on temperature is influenced not only by fuel composition but also by fuel-air mixing rate.

这项研究的目的是阐明燃料对喷火点火和点火的影响，并注意燃料中成分之间的干扰。首先，使用快速压缩机和流动反应器中的气体采样技术在化学方面研究了燃料在点火过程中的变化。结果表明，由于从相邻的最初氧化混合物提供的热量升高，燃料会在快速和大量释放之前分解为小碳氢化合物。包括小碳氢化合物在内的中型化学物种的生产速率会影响燃料喷雾剂的点火延迟。首多是根据使用配备高压燃料注入系统的新建造的恒定体积容器获得的结果，讨论了燃料空气混合和燃料效应之间的关系。在80-160MPA的注入压力和喷嘴孔直径为0.14-0.22mm时测量并检查点火过程中的点火延迟和压力疗程。结果表明，燃料对点火延迟的效果在高压注射案例中使用小喷嘴孔减小。仅在燃料氧化速度较慢的环境压力的情况下观察到效果。据认为，由于快速的燃油 - 空气混合，局部混合物的快速温度升高会缩短累积小碳氢化合物所需的时间。在环境温度的一定愤怒中，直链饱和烃是产生中间物种的主要来源，而燃料中的芳族碳氢化合物在点火之前充当无活性物种。这就是当将芳香族添加到燃料中时延迟点火的原因。名义活化能量对温度的依赖性不仅受燃料成分的影响，还受燃料空气混合速率的影响。