A Study Describing the Performance of Diesel Particulate Filters During Loading and Regeneration - A Lumped Parameter Model for Control Applications

A computational lumped parameter model (MTU-Filter-Lumped) was developed to describe the performance of diesel particulate filters (DPFs) during loading and regeneration processes. The model was formulated combining three major sub-models: a filtration model, a pressure drop model, and a mass and an energy balance equation for the total filter volume. The first two sub-models have been widely validated in the literature, while the third sub-model is introduced and combined with the first two sub-models in the present study. The three sub-models combined can give a full description of diesel particulate filter behavior during loading and regeneration processes, which was the objective of the present work. The total combined lumped parameter model was calibrated using experimental data from the literature covering a range of experimental conditions, including different catalytic regeneration means and engine operating conditions. The model predictions showed very good agreement with the experimental data in terms of pressure drop across the filter, mass retained in the filter, and filter temperature. A diesel particulate filter system was selected to illustrate the control application of the lumped model equations. This system involves a diesel particulate filter for the collection and oxidation of the engine out particulate matter emissions, and the injection of hydrocarbons upstream of an oxidation catalytic converter (OCC) in order to raise the exhaust gas temperature and in turn achieve filter regeneration. Two model-based control strategies were developed aiming to minimize the fuel penalty of the regeneration process described above.