A Simplified Catalytic Converter Model for Automotive Coldstart Control Applications
Pannag R Sanketi, Karl Hedrick, Tomoyuki Kaga

Citation
Pannag R Sanketi, Karl Hedrick, Tomoyuki Kaga. "A Simplified Catalytic Converter Model for Automotive Coldstart Control Applications". Proceedings of 2005 ASME International Mechanical Engineering Congress and Exposition (IMECE2005), November, 2005; Orlando, Florida USA.

Abstract
More than three-fourths of the unburned hydrocarbon (HC) emissions in a typical drive cycle of an automotive engine are produced in the initial 2 minutes of operation, commonly known as the coldstart period. Catalyst light-off plays a very important role in reducing these emissions. Model-based paradigm is used to develop a control-oriented, thermodynamics based simple catalyst model for coldstart purposes. It is a modified version of an available model consisting of thermal dynamics and static efficiency maps, the critical modification being in the thermal submodel. Oxygen storage phenomenon does not play a significant role during the warm-up of the engine. The catalyst is modeled as a second-order system consisting of catalyst brick temperature and temperature of the feedgas flowing through the catalyst as its states. Energy balance of an unsteady flow through a control volume is used to model the feedgas temperature, whereas energy balance of a closed system is used to model the catalyst brick temperature. Wiebe profiles are adopted to empirically model the HC emissions conversion properties of the catalyst as a function of the catalyst temperature and the air-fuel ratio. The static efficiency maps are further extended to include the effects of spatial velocity of the feedgas. Experimental results indicate good agreement with the model estimates for the catalyst warm-up. It is shown that the model represents the system more accurately as compared to the previous model on which it is based and offers a broader scope for analysis.

Electronic downloads

(No downloads are available for this publication.)

Citation formats

• HTML

  Pannag R Sanketi, Karl Hedrick, Tomoyuki Kaga. <a
  href="http://chess.eecs.berkeley.edu/pubs/87.html"
  >A Simplified Catalytic Converter Model for Automotive
  Coldstart Control Applications</a>, Proceedings of
  2005 ASME International Mechanical Engineering Congress and
  Exposition (IMECE2005), November, 2005; Orlando, Florida USA.

• Plain text

  Pannag R Sanketi, Karl Hedrick, Tomoyuki Kaga. "A
  Simplified Catalytic Converter Model for Automotive
  Coldstart Control Applications". Proceedings of 2005
  ASME International Mechanical Engineering Congress and
  Exposition (IMECE2005), November, 2005; Orlando, Florida USA.

• BibTeX

  @inproceedings{SanketiHedrickKaga05_SimplifiedCatalyticConverterModelForAutomotiveColdstart,
      author = {Pannag R Sanketi and Karl Hedrick and Tomoyuki Kaga},
      title = {A Simplified Catalytic Converter Model for
                Automotive Coldstart Control Applications},
      booktitle = {Proceedings of 2005 ASME International Mechanical
                Engineering Congress and Exposition (IMECE2005)},
      month = {November},
      year = {2005},
      note = {Orlando, Florida USA},
      abstract = {More than three-fourths of the unburned
                hydrocarbon (HC) emissions in a typical drive
                cycle of an automotive engine are produced in the
                initial 2 minutes of operation, commonly known as
                the coldstart period. Catalyst light-off plays a
                very important role in reducing these emissions.
                Model-based paradigm is used to develop a
                control-oriented, thermodynamics based simple
                catalyst model for coldstart purposes. It is a
                modified version of an available model consisting
                of thermal dynamics and static efficiency maps,
                the critical modification being in the thermal
                submodel. Oxygen storage phenomenon does not play
                a significant role during the warm-up of the
                engine. The catalyst is modeled as a second-order
                system consisting of catalyst brick temperature
                and temperature of the feedgas flowing through the
                catalyst as its states. Energy balance of an
                unsteady flow through a control volume is used to
                model the feedgas temperature, whereas energy
                balance of a closed system is used to model the
                catalyst brick temperature. Wiebe profiles are
                adopted to empirically model the HC emissions
                conversion properties of the catalyst as a
                function of the catalyst temperature and the
                air-fuel ratio. The static efficiency maps are
                further extended to include the effects of spatial
                velocity of the feedgas. Experimental results
                indicate good agreement with the model estimates
                for the catalyst warm-up. It is shown that the
                model represents the system more accurately as
                compared to the previous model on which it is
                based and offers a broader scope for analysis.},
      URL = {http://chess.eecs.berkeley.edu/pubs/87.html}
  }
  

Posted by Pannag R Sanketi on 11 May 2006.
For additional information, see the Publications FAQ or contact webmaster at chess eecs berkeley edu.