Numerical analysis on a novel CGPFs for improve NOx conversion efficiency and particulate combustion efficiency to reduce exhaust pollutant emission

Abstract

Improving the NOx conversion efficiency and particulate combustion efficiency under cold start conditions (low temperature conditions) is still the main challenge faced by catalytic gasoline particulate filter system (CGPFs). In this study, the physical and mathematical models of novel CGPFs are proposed based on the computational fluid dynamics software. Then, the models are validated based on experiments, and the performances of conventional and novel CGPFs are analyzed comparatively. The comparison conclusions indicate that the NOx conversion efficiency of the novel CGPFs increases by 3.2% and the particulate combustion efficiency increases by 2.7% under the same operating condition. Finally, the effects of exhaust flow vf, exhaust oxygen concentration Co, exhaust NO concentration CNO and electric heating power Pe on the NOx conversion efficiency and particulate combustion efficiency are investigated. The weights of each influencing parameter on the NOx conversion efficiency and particulate combustion efficiency are explored by orthogonal tests. The conclusions show that the NOx conversion efficiency is increased by 3.6% and the particulate combustion efficiency is increased by 16.7% compared to the initial condition. This study has an important reference value for improving the purification efficiency of vehicle emission under cold start conditions.