LNT의 기하학적 형상이 NOx 전환 효율에 미치는 영향에 대한 수치적 연구

Abstract

he lean NOx trap (LNT) is one of the promising technologies for the NOx reduction of gasoline lean bum and diesel engines to meet more stringent future emission regulations such as EURO 5 or 6. The adsorption sites in the wash coat take up NOx from engine exhaust gas during the lean condition and store NOx as nitrates. After running at the lean condition for a period of time, LNT is operated under the rich condition for a few seconds. Therefore, adsorbed NOx is released from the BaO sites and then reduced on the Pt sites. In this paper, a one-dimensional two-phase model of an adsorptive catalytic monolith reactor has been used to predict the performance of LNT in terms of NOx and CO conversion efficiency. The parametric investigations are numerically performed to examine the effect of the volume of LNT with various lengths and cross-sectional areas, GHSV(Gas Hourly Space Velocity), and geometric parameters such as cell density and wall thickness on the performance of LNT. An increase of GHSV decreases the NOx and CO conversion efficiency.