A virtual diesel aftertreatment exhaust line is presented comprising DOC, DPF, SCR models and a unique Ammonia Oxidation catalyst model. All models are one dimensional models based on first principles. These models offer an attractive compromise between speed, accuracy and complexity for a variety of model applications: off-line simulation, control strategy development, Hardware in the Loop applications and model-based calibration. The implemented models are fast and suitable for real-time applications. Use of these virtual exhaust line models in a product development process has the potential of saving time and resources.
The aftertreatment models are fitted based on specifically designed engine dynamometer experiments, which can be performed in a limited time frame. The effective test time required on a validated test setup is estimated on the order of 12 days in total. Specifically developed software tools facilitate the model fit process. These dedicated fit tools autonomously find parameter estimates for all the aftertreatment models. Isolated catalyst models and the complete virtual exhaust line show good correlation to measurements from a heavy-duty test setup.
This work has a focus on practical aspects like model applications and test program. Model fits for DOC, DPF, SCR, and Ammonia Oxidation catalyst are presented. Three short case studies illustrate model use in practice.