Research On Catalytic Diesel Particulate Filter Load And Regeneration Performance

Diesel particulate emission is one of the important causes of fog and haze weather, Air pollution is serious injure on human health. With the tightening of motor vehicle emission regulations and air purification needs, diesel exhaust particulate purification technology research becomes hot and important topics in recent years. DPF (Diesel Particulate Filter) is the most effective solution to reduce diesel particulate emissions, but due to high temperature regeneration, regeneration timing judging difficulty, those issues limit the development of DPF. In the DPF carrier coated amount of noble metal catalyst, The CDPF (Catalyzed Diesel Particulate Filter) you can take advantage of the strong oxidizing NO2 to effectively reduce particulate regeneration temperatures to ensure continuous regeneration of the DPF. Through a combination bench and simulation model, we do analysis on pressure drop of CDPF, the soot loading process, and the regeneration characteristics under different coating amount.It offers a theoretical basis and practical guidance for CDPF Passive regeneration performance and controlled the amount of precious metal catalyst coated in CDPF. Research indicates:1) By comparing with three different coating amount of the noble metal catalyst CDPF, the pressure drop is increased with the increased coating amount of catalyst and the temperature, as well as the increased the exhaust gas mass flow rate. The greater the amount of the catalyst coating CDPF, which capture the same mass of soot, the greater the pressure drop. Compared with the coated amount of substrate 19g/l and 29g/l, the maximum pressure drop difference is 0.68KPa.The more coated CDPF, the stronger its passive regeneration, and its produces the more NO2 in passive regeneration process. Compared with the three kinds of coating amount of catalyst carrier coating amount, Increase each additional 5g/l, NO2 at the outlet of CDPF increases about 50 ppm.2) CDPF’s soot loading, its deep bed loading is only 0.4g/l, but its pressure drop is increases rapidly. In the cake layer, the pressure drop increase has linear relationship with the soot increase. but the rate of increase has declined markedly.3) Through the model simulation studies on 19g/l coating amount of the carrier,we know the balance point temperature for the CDPF is 350 ℃, and the 29g/l CDFP is 325 ℃. In the temperature range below 375 ℃, with the temperature increases, the substrate passive regeneration is growing.we can further know the regeneration order from the deposition amount of carbon changes. The deep bed regeneration takes place first, then transition to the cake layer.4) DOC can promote the conversion of NO to NO2, but conversion efficiency is not remarkable at temperatures below 300℃. At 375 ℃, the conversion efficiency is up to the 43% as maximum.By the conversion efficiency increase of DOC s, the increased the content of NO2 can participate in CDPF passive regeneration. The simulation results show that,NO2 content is 300ppm at the entrance comparison with Oppm at the entrance, Carbon regenerated difference 0.4g/l.The results of this study to reduce diesel particulate matter pollution of the atmospheric environment has some theoretical support, and promotion of Catalyzed Diesel Particulate Filter are widely used in diesel engine, while controlling costs and other aspects of the economy has important theoretical significance.