Mathematical modeling of automotive three-way catalytic converters with oxygen storage capacity

Aimard, F; Li, S; Sorine, Michel

doi:10.1016/0967-0661(96)00111-6

Cited by 22 publications

(17 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One possible explanation for this behavior might be the storage of hydrocarbons on the TWC during extensive rich operation. The hydrocarbons might get desorbed during the succeeding lean phase, leading to a rich postcat k. [20][21][22]. Nevertheless several approaches can be found in literature introducing simplifications to the system to make it more feasible for control-purposes.…”

Section: Conversion Efficiencymentioning

confidence: 99%

Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

Nüesch

Stefanopoulou

Jiang

et al. 2014

Journal of Dynamic Systems, Measurement, and Control

View full text Add to dashboard Cite

Highly diluted, low temperature homogeneous charge compression ignition (HCCI) com-bustion leads to ultralow levels of engine-out NOx emissions. A standard drive cycle, however, would require switches between HCCI and spark-ignited (SI) combustion modes. In this paper we quantify the efficiency benefits of such a multimode combustion engine, when emission constraints are to be met with a three-way catalytic converter (TWC). The TWC needs unoccupied oxygen storage sites in order to achieve acceptable performance. The lean exhaust gas during HCCI operation, however, fills the oxygen storage and leads to a drop in NOx conversion efficiency. If levels of tailpipe NOx become unacceptable, a mode switch to a fuel rich combustion mode is necessary in order to deplete the oxygen storage and restore TWC efficiency. The resulting lean-rich cycling leads to a penalty in fuel economy. Another form of penalty originates from the lower combustion efficiency during a combustion mode switch itself. In order to evaluate the impact on fuel economy of those penalties, a finite state model for combustion mode switches is combined with a longitudinal vehicle model and a phenomenological TWC model, focused on oxygen storage. The aftertreatment model is calibrated using combus-tion mode switch experiments from lean HCCI to rich spark-assisted HCCI (SA-HCCI) and back. Fuel and emission maps acquired in steady-state experiments are used. Differ-ent depletion strategies are compared in terms of their influence on drive cycle fuel econ-omy and NOx emissions. It is shown that even an aggressive lean-rich cycling strategy will marginally satisfy the cumulated tailpipe NOx emission standards under warmed-up conditions. More notably, the cycling leads to substantial fuel penalties that negate most of HCCI’s efficiency benefits. [DOI: 10.1115/1.4028885]

show abstract

Section: Conversion Efficiencymentioning

confidence: 99%

Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

Nüesch

Stefanopoulou

Jiang

et al. 2014

Journal of Dynamic Systems, Measurement, and Control

View full text Add to dashboard Cite

show abstract

“…All assumptions mentioned earlier are common in TWC modelling (e.g. ). Applying mass and energy balance equations for the three partitions outlined earlier yields the following system of PDEs , see Table for a nomenclature and the values of the parameters.…”

Section: Mathematical Model Of the Three‐way Catalytic Convertermentioning

confidence: 99%

“…First principles modelling for the TWC usually leads to a mathematical description in form of partial differential equations (PDEs) (e.g. ). Thereby, the complexity of the model is mainly determined by the level of detail used to describe the chemical reactions within the TWC.…”

Section: Introductionmentioning

confidence: 99%

Extended Kalman filter and adaptive backstepping for mean temperature control of a three‐way catalytic converter

Utz

Fleck

Frauhammer

et al. 2013

Intl J Robust & Nonlinear

View full text Add to dashboard Cite

This contribution is concerned with an adaptive control strategy for the mean temperature of an automotive three-way catalytic converter. Tailored finite-dimensional approximations of the complex infinitedimensional mathematical model of the catalytic converter serve as a basis for the design of an extended Kalman filter for state profile estimation and of an adaptive backstepping controller for the mean temperature. Although the model used for observer design relies on (semi-)discretising the infinite-dimensional model, a simple model for the mean temperature employing a phenomenological approach to describe the reaction heat is used for control design. The observer/controller is tested in simulation scenarios using a validated model of the three-way catalytic converter. 3439The solid support consists of steel or ceramics and allows for heat conduction in axial direction only. The chemical reactions primarily take place on the surface of the solid support.Thus, a spatially one-dimensional model with the spatial variable´denoting the axial position within the TWC can be established. All assumptions mentioned earlier are common in TWC modelling (e.g. [5][6][7]). Applying mass and energy balance equations for the three partitions outlined

show abstract

“…Some earlier papers describe the modelling fundamentals of the modern honeycomb three-way-catalyst [3], while more recent research is focused on the development of kinetic models of modern aftertreatment systems, like NO xstorage catalysts [4]. Not to forget from an engineering perspective are models associated with the heat transfer in pipes [5], or flow simulations and their effect on emission performance [6], as well as models developed for specific purposes, such as on-board diagnostics (OBD) [7].…”

Section: Introductionmentioning

confidence: 99%

Modeling of Catalytic Exhaust Aftertreatment Systems: From Laboratory Reactor Data to Successful Prediction of Emissions From Vehicles

Ekström¹,

Wallin²,

Fathali³

et al. 2009

Top Catal

View full text Add to dashboard Cite

Complete driving cycle emissions from vehicles have been simulated, using the in-house code SiKat. Analysis of vehicle test results, with respect to test-to-test variations, reveals the emission levels due to various aftertreatment configurations. Careful layout of laboratory reactor experiments provides accurate data for tuning of the model, which is used to predict the oxygen storage capacity of the catalyst and the NO x -emissions as a function of aging during the useful life of the vehicle.

show abstract

Mathematical modeling of automotive three-way catalytic converters with oxygen storage capacity

Cited by 22 publications

References 9 publications

Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

Extended Kalman filter and adaptive backstepping for mean temperature control of a three‐way catalytic converter

Modeling of Catalytic Exhaust Aftertreatment Systems: From Laboratory Reactor Data to Successful Prediction of Emissions From Vehicles

Contact Info

Product

Resources

About