Investigation of DOC, DPF and SCR for reduction in diesel emissions

Abstract

An in-house computational code capable of simulating the physico-chemically highly coupled phenomena occurred in the diesel exhaust aftertreatment systems such as DOC, DPF, and SCR was developed. To do that, the mathematical modeling for DOC, DPF, and SCR was individually performed first. In this process, the state-of-the-art models and schemes were employed with reference to the relevant literatures. Particularly, the current numerical modeling was focused on the cost-effectiveness as well as to the applicability in the real design and development processes. And then, on the basis of the mathematical modeling, an in-house computational code was developed using the FORTRAN 90 languages. For a verification of its reliability, the developed code for each aftertreatment device was firstly validated with other known experimental and computational results from the literature. Also, through many preliminary computations, the reasonable tendencies of the numerical solutions were demonstrated. Finally, using the developed numerical tools, the primary factors controlling the system performance were calibrated based on the experimental results. With and employmet of the newly determined control parameters, the simulation results were validated with the experimental results. For the DOC, the kinetic parameters of several model reactions were newly calibrated based on both steady and transient cycle experimental results currently obtainde on an engine-dynamomoter test bench. For the DPF, the deposit microscopic properties such as porosity and permeability were newly determined based on the measured datd taken from the literature. For thd SCR, the kinetic parameters of the ammonia adsorption/desorption were newly calibrated based on the current power-phase TPD experiments and thd kinetic paramethers of the several model reactions were also newly determined based on the core-out monolith experiments currently conducted. For all of the developed numerical tools of DOC, DPF, a...