正/负电场对预混稀燃火焰影响的对比研究

Comparative Research on Effect of Positive/Negative Electric Field on Premixed Lean Burn Flame

为了比较正/负电场的助燃效果,在室温298K、气压100kPa条件下,通过对定容燃烧弹内的网状电极分别加载正直流电压和负直流电压,研究了正/负电场助燃机理,由此分析了2种电压对甲烷/空气预混火焰形状、火焰传播速度以及燃烧压力等参数的影响。结果显示:正/负直流电场对过量空气系数分别为1.2、1.6的预混稀燃火焰均有促进作用,平均火焰传播速度在施加电压的电极方向得到增强;在施加电场后,相同过量空气系数下的火焰燃烧峰值压力增大,且随着电压幅值绝对值的增大,峰值压力到达时间相应缩短;在相同的电压幅值下,正电场的促进效果优于负电场。该结果对电场辅助燃烧的进一步研究具有指导意义。

To compare the effects of positive and negative electric fields, at room temperature 298 K and under pressure 100 kPa, a mesh electrode is loaded with positive DC and negative DC voltage in constant volume combustion bomb to analyze the different voltage influences on the methane/air premixed flame shape, flame propagation velocity, combustion pressure and other parameters. The results show that the positive/negative DC field promotes premixed lean combustion flame with excess air coefficient 1.2/1.6, and the average flame propagation speed is enhanced in the direction of the electrode voltage. When the electric field is applied, the peak combustion pressure increases under the same excess air coefficient, and with the increasing absolute value of the voltage amplitude, the arrival time of the peak pressure is reduced accordingly. For the same voltage magnitude, the positive electric field effect is always better than that of negative electric field.