Numerical simulation on soot combustion and deposition in continuously regenerating diesel filter

Abstract

Since particulate matters (PM) emissions including soot from diesel cars do harm to our health, a diesel particulate filter (DPF) has been used in the after-treatment of exhaust gas. It is reported that DPF filling with PM causes higher back-pressure and more fuel consumption, and continuously regenerating PM trap system is needed. Then, we have focused on the diesel exhaust gas perfect burning system (DEGPBS) developed by COTEC, Ltd, where soot is trapped and burned by the heater. However, the phenomena in the system are not well understood, because it is difficult to conduct the measurement inside the filter. In this study, we simulated soot combustion and deposition by the lattice Boltzmann method to observe the combustion field in the filter. The inner structure of the filter was obtained by a 3D X-ray CT technique. Results show that the heat and mass transport in DEGPBS are well visualized. It is found that temperature of the filter and oxygen concentration are important factors to burn soot in exhaust gas.