Original Modeling Approach of Diesel Particulate Filter Regeneration

Since the particulate emissions of Diesel engine are suspected to be harmful on health, the standards limiting this source of pollutant are increasingly stringent: 0.05 g/km for 2000 and 0.025 g/km for 2005 (for light duty vehicles). Diesel Particulate Filters (DPF) are known for their large filtration efficiency in terms of nano-particles and therefore, constitute the most effective solution to reduce these emissions. The development of such a technology implies the combination of a trap and regeneration process. This requires the implementation of advanced engine management strategies aimed at periodically rising exhaust gas temperature to reach the particle light -off.

In order to set such strategies, it appears necessary to build a numerical regeneration model.

This paper reports an original modeling approach. It presents a relatively simple model to capture the main features of a DPF's regeneration behavior, namely temperature, oxygen content, and soot depletion. It uses a model based on “coupled” interactions between the exotherm (and combustion mechanism) and the DPF response. The numerical results are compared to the engine bench test results in order to validate the capacities of the model. This model will be further used to develop and compare various strategies for the thermal gradients control.