NO and NO2 modeling for diesel oxidation catalyst at different thermal aging levels
Abstract
Different DOC modeling methods are analyzed and compared. Detailed reaction mechanisms of DOC reaction are discussed and a new NO and NO2 modeling technique is proposed. Experiments are conducted measuring downstream DOC NO and NOx. DOC out NO and NO2 concentrations are modeled as a function of DOC temperature. A robust model is built such that with the input of real time NOx and DOC temperature information, DOC-out NO and NO2 concentrations can be precisely predicted. As is true with many catalysts, the DOC thermally ages as it operates, which reduces the thermal effectiveness level of the catalyst. This directly reduces the amount of HC, CO and NO it is able to oxidize, increasing the DOC-out NO percentage. In this thesis, aged DOC model is recalibrated in modeling DOC-out NO and NO2 concentrations. Correlations between HC light-off temperature shift and DOC-out NO and NO2 concentration shift are discovered and analyzed. A preliminary model of NO and NO2 concentrations as a function of HC light-off temperature and DOC temperature is built and validated against actual data.
Degree
M.S.E.
Advisors
Meckl, Purdue University.
Subject Area
Automotive engineering
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