An efficient product design tool for aftertreatment system

Abstract

A numerical simulation technique based on the conservation of mass and energy in the gas phase has been developed to optimize the aftertreatment system with the lowest costs. Both oxygen storage capacity model and catalyst deterioration model have been integrated into the three-way catalyst performance model. Applications have been discussed, including XY-L 1.5L I3 gasoline turbocharged direct injection (GTDI) production hybrid vehicle, BY-L 1.5L I4 GTDI hybrid vehicle, XY-L (overseas version) 1.5L I4 GTDI hybrid vehicle, and G-L7 1.5L I4 GTDI hybrid vehicle. Vehicle tests in support of the proposed model have been described. The developed model covers the complete range of the cold start, high temperature and volume flow conditions. To optimize a three-way catalyst performance, this work simulated the effect of air fuel ratio, space velocity, temperature, biasing adjustment on the catalyst efficiency. The simulations presented the technique’s capability of well predicting emissions on fresh and full useful life aged aftertreatment systems, respectively, and carried out under transient conditions. The investigation indicated that excess fueling was used upon engine start to heat the catalyst up to its full operating temperature of greater than 350°C. The model results prompted a redesign of the I3 and I4 1.5L GTDI China 6b, Euro VId and Tier 3/SULEV30 exhaust systems over the world light vehicle test procedure (WLTP) and federal test procedure (FTP) cycles, respectively, for example, the model suggested that the latest design for the SULEV30 aftertreatment system on XY-L (overseas version) 1.5L I4 GTDI hybrid vehicle with the revised calibrations in the areas of cold-start and closed-loop fuel treated emissions of NMOG, NOx, and CO to the 70% of the SULEV30 standards with a $64 cost reduction relative to the baseline.