Empirical Temperature Modelling of the Diesel Oxidation Catalyst

Sustaining the light-off temperatures of the catalytic converter can no longer be guaranteed at all times due to progressive hybridization of the powertrain. External electrical heating allows to obtain the light-off temperatures in a targeted manner and thus to minimize emissions, even under more difficult conditions. For helping to decide when this external energy supply is required, a real-time temperature model is needed. In the presented approach, the temperature is calculated by using different exponential growth functions for different loads. For these mathematical functions two parameters, the maximum temperature and the growth gradient, need to be identified. These parameters are determined empirically on a test bench. Results of different WLTC observations show a high conformity between the predicted temperature curves and the temperature actually measured.