Designing a fast‐igniting catalytic converter system

Keith, Jason M.; Chang, Hai‐Chou; Leighton, David T.

doi:10.1002/aic.690470313

Cited by 20 publications

(21 citation statements)

References 14 publications

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“…Later, simplified catalyst modeling approaches have been introduced (e.g. (Please et al 1994), (Leighton & Chang 1995), (Ramanathan et al 2004), (Keith et al 2001)). Such approaches have provided insights into catalyst parameters optimization (void fraction, material, precious metal loading distribution, .…”

Section: Reduced Modelmentioning

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: Reduced Modelmentioning

confidence: 99%

Model-based temperature control of a diesel oxidation catalyst

Lepreux¹,

Creff²,

Petit³

2012

Journal of Process Control

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“…within the bed Keith et al, 1999;Keith, 2002 which in turn invokes a transient Taylor-Aris thermal dispersion mecha-Ž . nism Taylor, 1953;Aris, 1956;Keith et al, 2001 . Without having detailed data on transient temperature profiles, some thermal dispersion near the entrance should make it easier for the temperature sensors to detect these spikes and control the reactor.…”

Section: Discussionmentioning

confidence: 97%

Novel scheme for delaying reverse‐flow reactor runaway

Keith

2002

AIChE Journal

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The reverse-flow packed-bed reactor has been proposed for use in the chemical process industries because of its ability to Ž store thermal energy within the bed Boreskov and Matros, . 1983 . During periods of high fuel concentration, large thermal spikes may form within the reactor upon flow reversal. If the duration of high fuel concentration is large, thermal runaway may result since the spikes grow in magnitude upon each other. A new scheme is proposed here which strategically reduces the flow reversal time with each half-cycle in order to utilize the entire bed to store thermal spike energy. Alternatively, the principles outlined here can be used to reduce the startup time of reverse-flow reactors.

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“…These reactions are highly exothermic in nature and start only after the catalyst has been preheated as stated by Keith et al [8], Hayes and Kolaczkowski, [6] and Heck et al [3]. Initially these reactions are kinetically controlled and after the light off point they become mass-transfer controlled.…”

Section: Introductionmentioning

confidence: 88%

Modeling exhaust gas pollution abatement: Part I — single hydrocarbon propylene

Chauhan

Srivastava

2008

Computers & Mathematics with Applications

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The one-dimensional models for catalytic converters are used to account for the reduction of pollutants like hydrocarbons (HC), carbon monoxide (CO) and nitric oxide (NO). The proposed model considers both gaseous as well as solid phase reactions of only one gas propylene that could possibly be occurring in the converter channels. Metal substrates were considered, as the better heat conducting solid material. The Runge-Kutta method and backward implicit schemes were employed to solve the coupled ordinary and partial differential equations.

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Designing a fast‐igniting catalytic converter system

Cited by 20 publications

References 14 publications

Model-based temperature control of a diesel oxidation catalyst

Model-based temperature control of a diesel oxidation catalyst

Novel scheme for delaying reverse‐flow reactor runaway

Modeling exhaust gas pollution abatement: Part I — single hydrocarbon propylene

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