高辛烷值组分对正庚烷着火燃烧特性的影响

The kinetic effects of three different kinds of high-octane components in the ethanol-gasoline such as ethanol, isooctane and toluene on the ignition characteristics of n-heptane are studied with the method of kinetic simulation. Results show that when the initial temperature is more than 1 000 K, the introduction of three different kinds of high-octane fuels has almost no influence on the ignition delay of n-heptane; whereas the high-octane fuels has obvious influence on the ignition delay of n-heptane at low initial temperatures. This is due to the fact that the introduction of high octane fuel at low temperatures inhibits the oxidative dehydrogenation of n-heptane, and hence influencing the subsequent low temperature chain reaction. In this way, the heat release of n-heptane during the low temperature stage is reduced, and the temperature rises slowly, thus the ignition is delayed. Of the three kinds of high octane fuels studied in this paper, the ethanol shows the strongest effect on delaying the ignition of n-heptane fuel. The effects of toluene and isooctane on the ignition delay of n-heptane are almost the same, and toluene shows slightly stronger delaying effect than isooctane.