APPARATUS AND METHOD FOR DETECTING AGED OF LEAN NOx TRAP CATALYST

摘要

PURPOSE: Degradation detecting apparatus and method of LNT(Lean Nox(nitrogen oxide) Trap) catalyst are provided to ensure the operation stability and reliability of a vehicle by diagnosing the degradation of LNT catalyst by analyzing the amount of reducing agent reacting to the regeneration of NOx and the amount of reducing agent slipped in a rich mode. CONSTITUTION: A degradation detecting apparatus of LNT(Lean Nox(nitrogen oxide) Trap) catalyst comprises LNT catalyst(200), first and second lambda sensors(210,220) and a control unit(300). The LNT catalyst occludes NOx in a lean mode and makes the NOx react with reducing agent to regenerate NOx. The first and second lambda sensors are respectively mounted on the front/rear end of the LNT catalyst and detect lambda values. The control unit calculates the amount of reducing agent used for reducing of NOx and the amount of reducing agent slipped using the signals of the first and second lambda sensors and determines the degradation of the LNT catalyst according to the slip ratio.