非平衡等离子辅助催化对柴油机排放的影响

Effect on non-thermal plasma assisted catalyst technology in diesel hazardous emission reduction

分析了非平衡等离子和介质阻挡放电的产生机理.根据非平衡等离子产生活性基体的特点,建立了非平衡等离子辅助催化对柴油机有害排放的转化模型.采用蜂窝式介质阻挡放电反应器辅助催化装置,在台架试验上研究了不同试验方案对降低有害排放的影响.试验结果表明在不添加催化剂的情况下,NOx的总量基本不变,表明非平衡等离子气相区内主要是将NO氧化为NO2;添加催化剂后,NOx的总量明显下降,表明NO2被还原为N2.同时PM颗粒与强氧化性的活性基体反应生成CO2得以大幅度降低,证明了利用非平衡等离子辅助催化技术可以有效降低柴油机NOx和PM颗粒排放.

The formation of non-thermal plasma and dielectric barrier discharge mechanism were analysed. According to the characteristics that non-thermal plasma can produce active radicals, a non-thermal plasma assisted catalyst model for conversing diesel hazardous emission was designed. A cell type dielectric barrier discharge reactor assisted catalyst device was used to study the reduction of the hazardous emission from the diesel engine, and different experiment projects were tested on its effect of reducing hazardous emission in bench test. The experimental result showed that the total NOx changes little, because NO was oxidized to NO2 primarily in gas phase without catalyst, and with catalyst the reduction of NO2 to N2 occurs greatly causing total NOx decreasing. PN was oxidized to CO2 with active radicals. The results showed that using non-thermal plasma assisted catalyst technology can efficiently reduce diesel NO, and PM emissions.