Effects of the continuous pulsation regeneration on the soot combustion in diesel particulate filter for heavy-duty truck.

Continuous pulsation regeneration combustion of soot is employed for sine and cosine simulation study. Data showed that pressure uniformity of sine condition is better than that of cosine condition with the maximum pressure difference of 4353.5 Pa under the same simulation boundary conditions. The maximum regeneration temperature under cosine pressure is 46.12 K which is higher than that in sine form. Regeneration combustion reaction zone tends to be more stable laminar flow and Reynolds number of sine condition is 435.23 less than that of under cosine condition. The maximum Stanton number of cosine pressure condition is 3.67 and that of sine pressure condition is 5.15, which investigates heat transfer capacity of the sine pressure condition is better than that of the pressure of cosine form. The regeneration efficiency of inlet gradually increased from the minimum regeneration efficiency 74.18%-88.45% of sine and cosine. The soot under both pressure forms has achieved complete regeneration and the regeneration efficiency has exceeded 88% of porous medium filter body section. The soot regeneration combustion efficiency of the porous media filter section and outlet section is more sufficient under sine condition and the heat carried by the fluid can maintain the soot regeneration.

NO2 catalytic formation, consumption, and efflux in various types of diesel particulate filter.

The high NO2/NOX ratio in the after-treatment system is beneficial to its performance and achieved by NO catalytic conversion in diesel oxidation catalyst (DOC) located upstream (CRDPF), catalytic DPF (CDPF), or a combination of both (CCDPF). In order to effectively control the emission of particulates and nitrogen oxides, various types of diesel particulate filter models are established to compare NO2 catalytic formation, consumption, and efflux. The results show that the catalytic performance of NO conversion is limited by mass transfer in DOC catalytic coating, while it is almost non-existent in CDPF. At low temperature, the passive regeneration of CDPF is slower than that of CRDPF, but as the temperature increases, the passive regeneration speed of CDPF will exceed that of CRDPF. CCDPF is the most effective for the NO2 catalytic formation, consumption, and efflux in the hot-start and high-speed cycle and thereby is conducive to improve the performance of the diesel particulate filter and downstream selective catalytic reduction.