Modeling of the Regeneration Processes in Diesel Particulate Filters

Abstract

New simulation algorithm of soot oxidation in diesel particulate filter (DPF) is proposed. Two-dimensional finite differences scheme is used for calculation of the heat transfer in DPF (macro-scale). One dimensional model for treatment of the soot oxidation process in a separate filter channel (micro-scale) is based on a new expression for the oxidation reaction rate that is a modification of the known Bissett's equation. This expression allows consideration of the non-linear dependence of oxidation reaction rate on a reagent concentration. For cases of catalytic coating a modification of the known two-layer model is suggested. A fraction of soot that has been oxidized with the help of the catalyst is not invariable in the first layer, but it exponentially depends on the distance from a channel wall of the particle trap. Soot oxidation by O 2 and/or NO 2 in diesel particulate filters is investigated for various cases of non-catalytic and catalytic oxidation. The filter clogging propagation from its periphery to the center at critical temperature is described theoretically at first. A comparison between various types of DPF regeneration methods is performed by using the proposed simple simulation algorithm and appropriate computer code.

Modelling the Influence of Different Soot Types on the Radio-Frequency-Based Load Detection of Gasoline Particulate Filters

“…However, it is not necessary to consider the kinetics of both reactions separately. According to References [ 49 , 50 ], the ratio of emitted CO 2 to CO can be expressed using a factor that depends on the temperature and oxygen content in the exhaust gas (Equation (14)): …”

“…For comparability with literature values, the molar mass of carbon g/mol is also included, such that the unit of is m 3 /kg·s [ 52 ]. For simplicity, the simulations and the corresponding reaction kinetic analyses assume a first-order reaction similar to several models in the literature [ 50 , 53 ]. An implementation of reaction orders different from one would be possible for complete regenerations.…”

“…On the other hand, in the case of incomplete oxidation and a subsequent loading, a description of the effects by mixed partially regenerated and fresh soot on the reaction order would be necessary. In simulation models for diesel engines, NO 2 combustion is also taken into account in some cases [ 50 ]. Due to the stoichiometric operation of gasoline engines and the resulting lower number of nitrogen oxides after the TWC, this model does not include that reaction.…”

The Challenges of Prolonged Gas Sensing in the Modern Urban Environment

“…Tartakovsky et al studied ways to regenerate diesel particulate filters by catalytically oxidating soot particles. Note that such a process requires considerable resources, such as catalysts and energy [ 23 ].…”