燃料的自燃过程及其在内燃机技术中的应用

摘要

Auto-ignition is an essential phenomenon in engine combustion process,which is controlled by chemical kinetics.The concept of knock integral approach proposed by Lenvingood and Wu is verified by the author's research on sketch kinetics of n-heptane.It is shown that during the auto-ignition of fuel,the radical OH plays an important role.Only if the heat release and CO in the low temperature reaction are accumulated to a certain level,at which the reaction H+O_2=O+OH can take place and the concentration of radical OH increases rapidly to transfer CO into CO_2 and with more heat release,the auto-ignition occurs.The advanced combustion technology based on the concept of auto-ignition control in engines is discussed in this paper.%"自燃"是燃料化学动力学控制的基本燃烧现象.本文通过正庚烷详细化学动力学机理和简化骨干机理相结合的研究方法,验证了Livengoodo-Wu"爆震累积临界值"概念(knock integral approach).证明当反应H·+O_2=O·+OH·的高活化能势垒被击穿,形成高浓度OH自由基,混合气释放出大量的热量,系统温度急剧升高,自燃发生.本文还介绍了"均质压燃、低温燃烧"技术的研究进展,燃料自燃过程的控制是现代内燃机技术的重要内容.