A Systematic Approach for Performance Comparisons of NOx Converter Designs

  • Author / Creator
    Bendrich, Michelle
  • In today’s vehicle applications, Selective Catalytic Reduction (SCR) ammonia dosing is completed using complex control algorithms that need to be parameterized for the individual catalytic converter technology. The parameterization of these control strategies is not always completed during the early design phase (i.e., simulation studies and laboratory tests), as this procedure is very time consuming. This results in catalytic converter screenings being completed with dosing strategies that do not allow for the observation of the true potential of each catalytic converter. Therefore, a challenge arises in the effective design of catalytic converters. This work presents a simulation-based method for the automated optimization of a simple ammonia dosing strategy, which can easily be used for simulations during the early catalytic converter design phase. The dosing strategy relies on a look-up table whose entries relate a desired ammonia surface coverage to a catalyst temperature. These entries are optimized for a given driving cycle to maximize the NOx conversion and fulfill the desired ammonia slip constraints. Using this strategy, comparisons of SCR catalyst technologies (iron and copper zeolite SCR) and catalyst volumes during driving cycles are completed. Likewise, the dosing strategy is applied to a catalytic converter configuration consisting of a front-end SCR and a back-end Ammonia Slip Catalyst (ASC) to study how an ASC can assist in meeting regulatory requirements during driving cycles.

  • Subjects / Keywords
  • Graduation date
    Fall 2014
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.