Numerical and experimental study on the gaseous emission and back pressure during regeneration of diesel particulate filters

In this study, the back pressure of Diesel Particulate Filter (DPF) during loading and regeneration phase is measured. Then, one dimensional approach has been implemented to model the exhaust emissions and back pressure of a DPF, focusing on the regeneration phenomenon. The simulation has been divided in three parts. In the first part, the model is validated with two types of experimental data. The first test has been done by the authors on a light duty diesel engine and the second one was conducted by Rothe et al. on a heavy duty diesel engine. In the next part, some parameters, which were costly to measure, are numerically obtained. In the last part, the effect of these parameters on exhaust emissions and back pressure during regeneration has been investigated. The results showed that the substrate/cake soot mass ratio has a strong effect on exhaust emissions, back pressure and improvement of the DPF regeneration efficiency. When this value increases from 0 to 1, the exhaust emissions (CO, CO2) increase by 94% and 95%, regeneration efficiency improves by 25% and back pressure dips to 22% respectively. It is found that the cake layer is a more efficient bed for soot burning in low substrate temperature and conversely the substrate wall is a most appropriate bed for soot burning at high temperature. Also, with an increasing in soot porosity from 0.56 to 0.96, the CO, CO2 emissions and regeneration efficiency, increase about 61%, 62% and 60% and the back pressure dips to 56% respectively.