MATHEMATICAL-MODELING OF ELECTRICALLY HEATED MONOLITH CONVERTERS - MODEL FORMULATION, NUMERICAL-METHODS, AND EXPERIMENTAL-VERIFICATION

The previously-developed transient monolith model has been extended to describe the thermal response and conversion performance of an electr ically heated monolith converter during warmup. This paper documents t he necessary modifications in the model formulation and in the numeric al solution methods to accommodate the more severe operating condition s encountered in heated converters. The validity of the heated convert er model was tested by comparing model predictions with vehicle emissi on test data. Model predictions of converter-bed temperatures and conv erter-out mass emissions agree well with those measured during the col d-start portion of the vehicle emission tests, thus demonstrating the validity of the heated converter model developed here.