A Three-Dimensional Model for the Analysis of Transient Thermal and Conversion Characteristics of Monolithic Catalytic Converters

Chen, David K. S.; Bissett, Edward J.; Oh, Se H.; Ostrom, David L. Van

doi:10.4271/880282

Cited by 115 publications

(48 citation statements)

References 14 publications

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“…Early models essentially described simplified energy balances (Vardi & Biller 1968), and progressively, more detailed mass balances were added (at least two mass balances per considered species are now considered). Spatial inhomogeneity has been considered too, from a multi 0-dimensional model (Kuo et al 1971) or a 1-dimensional model (Oh & Cavendish 1982), most recent automotive catalyst models lead to 2-dimensional or 3-dimensional simulation softwares ( (Chen et al 1988), (Tischer et al 2001), (Shamim et al 2002)). Obviously, they require heavy computational effort.…”

Section: Doc Detailed Modelingmentioning

confidence: 99%

Model-based temperature control of a diesel oxidation catalyst

Lepreux¹,

Creff²,

Petit³

2012

Journal of Process Control

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To cite this version:Olivier Lepreux. Model-based Temperature Control of a Diesel Oxidation Catalyst . Mathematics T H E S E pour obtenir le grade de DOCTEUR DE L'ECOLE NATIONALE SUPERIEURE DES MINES DE PARIS RésuméLe problème étudié dans cette thèse est la commande d'un système DOC (Diesel Oxidation Catalyst) tel qu'utilisé dans les systèmes de dépollution des gaz d'échappement des moteurs Diesel automobiles.Ce système est par nature un système à paramètres répartis en raison de sa géométrie allongée parcourue par un flux gazeux en contact avec un catalyseur réparti. Après avoir étudié expérimenta-lement ce système, nous avons décidé de prendre en compte cette nature répartie, qui comme on le montre, se retrouve également dans les autres systèmes de dépollution (filtres à particules, pièges à NOx, SCR).Une première contribution du manuscrit consiste en un modèle du système DOC. Celui-ci est obtenu par des simplifications successives, justifiées expérimentalement (observations, estimations des ordres de grandeurs) ou par analyse des équations régissant la dynamique du système (déve-loppements asymptotiques, changements de variables). Ce modèle permet de rendre compte de la complexité de la réponse de la température de sortie du DOC à des variations des grandeurs d'entrée. En particulier, les effets de réponses inverses et de retards sont bien représentés.Une seconde contribution est un ensemble d'algorithmes de commande (précompensation, rétro-action, et synchronisation) permettant de maîtriser les phénomènes thermiques dans le DOC.Ces deux contributions ont été testées expérimentalement et validées. En conclusion, les performances obtenues sont évaluées. En résumé, en utilisant l'approche présentée dans ce manuscrit, il est possible de commander, en conditions réelles, la température de sortie du DOC à ±15 • C. 6 SummaryThe problem studied in this thesis is the control of a DOC (Diesel Oxidation Catalyst) as used in aftertreatment systems of diesel vehicles.This system is inherently a distributed parameter system due to its elongated geometry where a gas stream is in contact with a distributed catalyst. After having studied this system experimentally, we decided to take into account its distributed nature, which as shown, is also found in other aftertreatment devices (particulate filters, NOx traps, SCR).A first contribution of the thesis is a model for the DOC system. It is obtained by successive simplifications justified either experimentally (from observations, estimates of orders of magnitudes) or by an analysis of governing equations (through asymptotic developments, change of variables). This model can account for the complexity of the temperature response of DOC output to changes in input variables. In particular, the effects of inverse responses and delays are well represented.A second contribution is a combination of algorithms (feedback, feedforward, and synchronization) to control the thermal phenomena in the DOC.Both contributions have been tested and validated experimentally. In conclusion, the o...

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Section: Doc Detailed Modelingmentioning

confidence: 99%

Model-based temperature control of a diesel oxidation catalyst

Lepreux¹,

Creff²,

Petit³

2012

Journal of Process Control

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show abstract

“…It is convenient to characterize these efforts in terms of their description of the gas phase within the catalytic passage, that is, whether the channel is one-dimensional (relying on heat-and mass-transfer coefficient correlations), two-dimensional (assuming axisymmetry, parallel flat plates, or external boundary-layer flow), or three-dimensional (no spatial simplifications). These studies have included: one-dimensional considerations of single passageways (Votruba et al, 1975;Heck et al, 1976;Young and Finlayson, 1976a,b;Sinkule and HlavLcek, 1978;Finlayson and Young, 1979;Marteney and Kesten, 1981;T'ien, 1981a,b;Oh and Cavendish, 1982;Prasad et al, 1983;Ahn et al, 1986;Zygourakis, 1989;Bennet et al, 1992;Tien and T'ien, 1992;Montreuil et al, 1992;Groppi et al, 1993;O h and Bissett, 1993;Leighton and Chang, 1995), multiple passageways (Flytzani-Stephanopoulos et al, 1986;Chen et al, 1988;Kolaczkowski et al, 1988;Kolaczkowski and Worth, 19951, two-dimensional solutions for single passageways (Heck et al, 1976;Young and Finlayson, 1976a,b;Finlayson and Young, 1979;Bennet et al, 1992;Lee and Aris, 1977;Harrison and Ernst, 1978;Zygourakis and Ark, 1983;Bruno et al, 1983;Ryan et al, 1991;Hayes et al, 1992Hayes et al, , 1996Boehman et al, 1992;Hayes and Kolaczkowsi, 1994;Groppi et al, 1995;Frye and Boehman, 1996;Boehman et al, 1997a,b), exter...…”

Section: Introductionmentioning

confidence: 99%

Radiation heat transfer in catalytic monoliths

Boehman

1998

AIChE Journal

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“…It can be shown that this behavior is obtained when the following condition is satisfied P nRct j¼1 a j ðÀDHÞ j R j ðx g;in; T s;lo Þ hSðT s;lo ÀT g;in Þ ! 1 (12) where T s,lo is given by Eq. 9.…”

Section: Light-off Locationmentioning

confidence: 99%

Light‐off location and front diffusion in a catalytic monolith reactor

Ramanathan

Gopinath

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).A one-dimensional solid-gas model has been used to study the light-off behavior in a reactor system. Techniques from nonlinear analysis are applied to first arrive at an analytical expression to estimate the light-off location in the reactor. The model is then extended to estimate the thickening of the light-off front in the vicinity of the light-off location due to heat diffusion effects in the solid substrate. Both these results are expressed in terms of all the important operating and design variables of the monolith reactor and also the reaction specific variables such as the kinetic parameters and heats of reaction. A specific case of a three-way catalyst (TWC) is numerically treated in detail to illustrate the application of this work. Finally, we focus on using the insight obtained from this study to suggest design guidelines to optimize the performance of automotive catalytic monolith reactors.

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A Three-Dimensional Model for the Analysis of Transient Thermal and Conversion Characteristics of Monolithic Catalytic Converters

Cited by 115 publications

References 14 publications

Model-based temperature control of a diesel oxidation catalyst

Model-based temperature control of a diesel oxidation catalyst

Radiation heat transfer in catalytic monoliths

Light‐off location and front diffusion in a catalytic monolith reactor

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