离子信号与空燃比关系的探讨

Study on the Relationship Between the Ionic Signal and the Air/Fuel Ratio

在定容燃烧弹中通过对点火电极附近离子信号的测量,表明了该信号主要由火焰前锋和火焰后区两部分组成．理论分析证明,火焰前锋的信号主要与电极附近火核中的H3O+离子和自由电子浓度有关,火焰后区的信号主要与已燃区中高温下激态的NO+和自由电子浓度有关,特别是火焰前锋区的信号与空燃比有直接关系．实验研究发现火焰前锋和后区的信号峰值随过量空气系数的变化趋势相同,当过量空气系数为1时均达最大值．因此,利用该信号可以实现空燃比的探测．

Measurement of the ionic signals near the ignition poles of a constant volume combustion bomb shows that the ionic signals mainly include flame front and post-flame. Theoretical analysis indicates that the amplitude of flame-front signal is mainly influenced by the concentrations of H2O^＋ and free electros in the flame kernal near the poles, and the amplitude of post-flame signal is influenced by the concentrations of NO ^＋ at excited state and free electrons. The signal in the flamefront is especially influenced by the air-fuel ratio near the poles. Measurement shows that the signals of both flame front and post-flame have the same trend when they change with relativ air-fuel ratios, reaching the maximum when the equivalence ratio is 1. So the ionic signals can be used to detect the air/fuel ratio.