CO CLEAN-UP CATALYST AFTER TREATMENT SYSTEM AND AFTER TREATMENT METHOD

• Main Authors: JUNG CHANGHO, JOO NAHM ROH, KIM CHANG HWAN
• Format: Patent
• Language: English; Korean
• Published: 11.08.2020
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

A post-treatment method is disclosed. The post-treatment method includes the steps of: operating an engine at a lean air-fuel ratio; calculating an amount of ammonia stored in a selective reduction catalyst; calculating an amount of nitrogen oxides to be introduced into the selective reduction catalyst; determining whether conversion to a rich air-fuel ratio is necessary; calculating a target air-fuel ratio and rich time to maintain the rich air-fuel ratio if conversion to the rich air-fuel ratio is necessary; and operating the engine for the rich time at the target air-fuel ratio. The present invention can maximize the amount of ammonia produced while reducing carbon monoxide discharged from a vehicle. 후처리 방법이 개시된다. 상기 후처리 방법은 연한 공연비에서 엔진을 운전하는 단계; 선택적 환원 촉매에 저장된 암모니아의 양을 계산하는 단계; 선택적 환원 촉매에 유입될 질소산화물의 양을 계산하는 단계; 농후한 공연비로 전환이 필요한지 판단하는 단계; 농후한 공연비로 전환이 필요하면, 농후한 공연비를 유지할 리치 시간 및 목표 공연비를 계산하는 단계; 그리고 목표 공연비로 리치 시간 동안 엔진을 운전하는 단계;를 포함할 수 있다.