柴油车尾气中NO对低温等离子体去除PM的影响

Effects of NO in Diesel Vehicle Exhaust on PM Removal Using Non-Thermal Plasma

采用介质阻挡放电净化柴油车尾气颗粒物(PM),在不同反应温度、水蒸气含量、氧气体积分数条件下研究了尾气中NO对PM去除效率的影响。结果表明,NO体积分数在0~1.5×10^(-4)时,可以提高PM的去除效率,而当NO体积分数达2.0×10^(-4)时,则会对PM去除有一定抑制作用。随着反应温度的升高,PM去除效率和转化率先升高后降低,在200℃时最高可达3.16 g/(kW·h)和66.51%。与此同时,NO可使PM氧化的活化能降至30.54 kJ/mol。尾气中水蒸气的增加会降低PM的去除效率,推测H_(2)O能抑制O和O_(3)的生成。当O_(2)体积分数从5%增加到20%时,PM去除效率增加。

Dielectric barrier discharge was used to remove diesel vehicle exhaust particulate matter(PM).The effect of NO on PM removal efficiency was studied under different reaction temperatures,water vapor contents,and oxygen volume fractions.The results showed that when the volume fraction of NO was in the range of 0—1.5×10^(-4),the removal efficiency of PM can be improved,while when the volume fraction of NO reached 2.0×10^(-4),it will inhibit the removal of PM.With the increase of reaction temperature,PM removal efficiency and conversion increased first and then decreased,up to 3.16 g/(kW·h)and 66.51%at 200℃.At the same time,NO reduced the activation energy of PM oxidation to 30.54 kJ/mol.The increase of water vapor in the exhaust gas will reduce the removal efficiency of PM,which may be due to the inhibition of H_(2)O on O and O_(3) formation.The PM removal efficiency increases when O_(2) volume fraction increasing from 5%to 20%.