System and process for exhaust gas purification using lean NOx trap (LNT) and catalyst with selective catalytic reduction

摘要

An exhaust gas purification system includes an internal combustion engine, a lean NOx trap installed on the exhaust pipe, a metering module mounted on the exhaust pipe downstream of the LNT, a selective catalytic reduction catalyst (SCR) installed downstream of the metering module on the exhaust pipe, and a controller for performing proportionate denitrification (DeNOx by the LNT and the SCR catalyst depending on the driving condition of the internal combustion engine, wherein the controller predicts a NOx purifying ratio of the SCR catalyst depending on the running condition of the engine and the regenerating power of the LNT based on the actual NOx purifying ratio of the SCR Catalyser sets.