Dual scr system and control method thereof

Abstract

According to an embodiment of the disclosure, there is provided a dual selective catalytic reduction (SCR) system including: a first SCR device provided downstream of an engine; a diesel particulate filter provided downstream of the first SCR device; a second SCR device provided downstream of the diesel particulate filter; and a controller including a first SCR efficiency determination unit to determine a first reduction efficiency of the first SCR device, wherein the first SCR efficiency determination unit calculates a first-1 reduction efficiency for maximizing passive regeneration of the diesel particulate filter, calculates a first-2 reduction efficiency for minimizing nitrogen oxides, and calculates a first-3 reduction efficiency which is a value between the first-1 reduction efficiency and the first-2 reduction efficiency according to coolant temperatures of the engine.

Dependencies are inferred from the claim text.