Pyrological characteristics of burner-type diesel particulate filter for regeneration

In order to obtain the pyrological characteristics of a burner-type diesel particulate filter (DPF), the mathematical model of pyrogenation regeneration process for burner-type wall-flow honeycomb ceramic filter was established, considering the subordinate oxidation reaction model. By solving the multi-fields coupling of flow velocity, pressure, temperature and particulate concentration, the variation laws of pyrological parameters were studied during burner-type diesel particulate filter (DPF) regeneration. The results showed that the pyrological parameters of burner-type system and exhaust characteristics had a great impact on the regeneration. With the air-fuel matching ratio, the pressure and rate of fuel injection and the air-supplied quantity increasing, the maximum wall temperature inside the filter channels rose and the oxidation rate of the deposition soot layer on the channel wall was accelerated, which shortened the regeneration process. But when the air-fuel matching ratio and air-supplied quantity increased further, the convection transfer heat loss of the gas flow through the soot layer became enhanced relatively, and when the fuel injection rate was improved further, the oxygen content in exhaust was insufficient, which would cause the combustion performance of the burner worsening, the oxidation rate of the soot layer and the maximum wall temperature decreasing and the regeneration process slowing down. The effect on the regeneration by exhaust mass flux was similar to that of air-supplied quantity, but from the analysis results, whether it could be controlled appropriately would be very important to the filter regeneration. The above laws provide the basis and technical references for the realization of safe, reliable and efficient regeneration and optimum control for diesel particulate filter.