Optimization of a Three-Way Catalytic Converter Through Engine Test-Bench Experiments
Typ
Examensarbete för masterexamen
Program
Systems, control and mechatronics (MPSYS), MSc
Publicerad
2021
Författare
Hernvall, Victor
Ravichandran, Abilash
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
A three-way catalytic converter model designed in a preceding thesis has been refined
and translated from SIMULINK into a script-based MATLAB model, to produce
faster, more stable and accurate solutions for the ordinary differential equations
(ODE). The model consists of nine ODE’s and are solved using the in-built ode15s
solver. The states of the model include O2, CO, C3H6, C3H8, H2, NO, CO2, H2O
concentrations and oxygen buffer levels for each slice of the catalyst. The scope of
the thesis is to gain an in-depth understanding of the workings within the catalyst
by conducting experiments in a test-rig where an engine has been used, so as to
mimic the composition of the exhaust in a real driving scenario, which is lacking
within the scope of literature. The thesis suggests a variety of methods to collect
and analyze data, these include using catalysts of different axial lengths (70, 30 and
15mm) and utilizing a heat-exchanger that allow the temperature dynamics to be
studied at higher resolution. The collected data is then used to optimize 30 kinetic
parameters in the model with the help of a built-in MATLAB function, lsqnonlin.
Results show that good emission predictions can be obtained for certain space velocities, with exceptions in higher temperature regions where the model lacks a
mass transfer description.
Beskrivning
Ämne/nyckelord
Three-way catalyst, optimization, lsqnonlin, MATLAB, ode, ceria, oxygen buffer