Characterisation and Model Based Optimization of a Complete Diesel Engine/SCR System 2009-01-0896
In order to make efficient use of a Diesel engine equipped with an SCR system, it's important to have a complete system approach when it comes to calibration of the engine and the aftertreatment system.
This paper presents a complete model of a heavy duty diesel engine equipped with a vanadia based SCR system. The diesel engine uses common rail fuel injection, a variable geometry turbocharger (VGT) and cooled EGR.
The engine model consists of a quasi steady gas exchange model combined with a two-zone zero dimensional combustion model. The combustion model is a predictive heat release model. Using the calculated zone temperatures, the corresponding NOx concentration is given by the original Zeldovich mechanism. The SCR catalyst model is of the state space type. The basic model structure is a series of continuously stirred tank reactors and the catalyst walls are discretized to describe mass transport inside the porous structure. Implicit methods are used to solve the ODEs which allow long time steps and high computational efficiency.
The combined engine-SCR model is a useful tool to characterize the system. A number of critical operating sequences are studied; step response from steady state low load conditions to high load and vice versa and also cold start experiments. Model based optimization is used aiming at achieving Euro VI emission levels while minimizing the brake specific fuel consumption (including Urea cost) by simultaneously optimizing the engine and SCR control parameters.
Citation: Ericson, C., Westerberg, B., Odenbrand, I., and Egnell, R., "Characterisation and Model Based Optimization of a Complete Diesel Engine/SCR System," SAE Technical Paper 2009-01-0896, 2009, https://doi.org/10.4271/2009-01-0896. Download Citation
Author(s):
Claes Ericson, Björn Westerberg, Ingemar Odenbrand, Rolf Egnell
Affiliated:
Scania CV AB
Pages: 14
Event:
SAE World Congress & Exhibition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Diesel Exhaust Emission Control, 2009-SP-2254
Related Topics:
Diesel / compression ignition engines
Fuel consumption
Fuel injection
Public transportation systems
Combustion and combustion processes
Selective catalytic reduction
Turbochargers
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