| Abstract:A test system using a reactor of double-dielectric non-thermal plasma（NTP） to pre-oxidize NO from diesel engine was established. The effects of discharge peak to peak voltage（Vp-p）, discharge frequency, exhaust flow and engine load on the performance of NTP′s pre-oxidizing NO were studied. The results show that, under the working condition of 2 100 r/min engine speed and 0% engine load and with the same discharge frequency, the volume fraction of NO and the total NOx first decrease and then increase as the Vp-p increases; the volume fraction of NO2 increase with the Vp-p; among different discharge frequencies, there always exits a critical value of the Vp-p which can make the ratio of NO to NO2 be 1∶1. The exhaust flow has insignificant effect on the performance of NTP′s pre-oxidizing NO. The NTP ability to pre-oxidize NO weakens gradually with the increase of engine load. When the engine load is 0% and 25%, NTP can make the ratio of NO to NO2 reach 1∶1, which helps to speed SCR reaction, thus improving the conversion rate of NOxat low temperature. |