Patent ID: 8240139
Filing Date: 2012-08-14
Classification: F01N,Y02T

Abstract:
1. A method for purifying nitrogen oxide which purifies nitrogen oxide contained in an exhaust gas, the method comprising: providing an exhaust system mounted at an exhaust pipe, wherein the exhaust system comprises: regenerating the DE-NOx catalyst by additionally injecting the fuel according to a predetermined injection pattern in a case that the driving condition of the engine satisfies an additional injection condition of the fuel and an additional injection timing condition of the fuel; wherein the additional injection condition of the fuel is satisfied when the engine operates normally and is not an idle state, shift does not occur, a current shift speed is higher than or equal to a first forward speed, an inlet temperature of the DE-NOx catalyst is within a catalyst activation temperature range, an engine rotation speed is within a predetermined rotation speed range, and regeneration does not occur successively.