A two-time-scale infinite-adsorption model of three way catalytic converters

Abstract

New regulations for emission control make urgent the performance improvement of the cascade engine-TWC (three-way catalytic converters). An important problem is minimization of the harmful emissions during the transient warm-up phase (where the largest amount of dangerous emissions is concentrated). In this perspective, dynamical TWC models, simple enough for online computation, are required. We present a distributed parameters TWC model suitable for the design and test of warm-up control strategies, obtained by considering an infinite adsorption rate between gas and substrate. The integration algorithm is based partly on a 'method of lines' space-discretization, partly on the 'method of characteristics' for 'quasi linear' hyperbolic PDEs, the separation being allowed by a two time scale analysis of the system. The model has been identified, through a purposely designed genetic algorithm, and validated on experimental data.