Effect of the amount of trapped particulate matter on diesel particulate filter regeneration performance using nonthermal plasma assisted by exhaust waste heat

An experimental system of diesel particulate filter(DPF)regeneration using non-thermal plasma(NTP)technology assisted by exhaust waste heat was conducted and regeneration experiments of DPFs with different amounts of trapped particulate matter(PM)were conducted.The concentrations of the PM decomposition products(CO,)and the internal temperature of the DPF were monitored to determine the performance of DPF regeneration and thermal safety of the NTP technology.The results showed that the concentrations of CO and CO2and the mass of P.V1 decomposition increased with the increase in the amount of captured PM,whereas the concentration of the NTP active substance(O,)escaping from the DPF decreased under the same working conditions of the NTP injection system.A higher amount of captured PM promoted the oxidative decomposition reaction between NTP and PM and improved the utilization rate of the NTP active substances.The peak temperature at the same measuring point inside the DPF generally increased and the phases of the peak temperature were delayed as the amount of captured PM increased.The temperature peaks and temperature gradients during the DPF regeneration process were far lower than llie failure limit value,which indicates that NTP regeneration technology has good thermal durability and increases the service life of the DPF.

Effect of indirect non-thermal plasma on particle size distribution and composition of diesel engine particles

To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter（PM）, a test bench for diesel engine exhaust purification was constructed, using indirect nonthermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10L min^-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma（NTP） improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10L min^-1 was more appropriate for the purification of particles.