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전성용(Sungyong Jeon),이천환(Chunhwan Lee),김덕진(Deokjin Kim),오광철(Kwangchul Oh),이종인(Jongin Lee),이춘범(Chunbeom Lee),권태희(Taehee Kwon),조재득(Jaedeuk Jo) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Today diesel engines are used extensively in the automotive, because they have excellent fuel economy and performance. But emissions from diesel engines are a significant air-quality issue by high emission of the NOx and PM. Many methods of aftertreatment have been developed since the advent of emission standards for diesel engines. The diesel aftertreatment system can be classifie into various categories by its target emission and reduction mechanism. The control methods and operating conditions are very important consideration for an each aftertreatment system. It is necessary to test with engine dynamometer precisely, since the characteristics of diesel emission are important parameters for the development of aftertreatment system. Although engine dynamometer test is necessary, it is not cost-effective. To reduce the prime cost, it is needed to build more cost-effective test equipments, In this work, the simple evaluation system was examined as a means of testing cost-effective using a real diesel engine and water-brake system.
정수진(Soo-Jin Jeong),김우승(Woo-Seung Kim),강우(Woo Kang),이제형(Je-Hyung Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Computational Fluid Dynamics(CFD) has been widely used in the automotive industry to simulate the flow within the converter. Most of CFD models for predicting flow through converter assume a monolith resistance based on one-dimensional laminar flow and treat a monolith as porous medium. However, auto-catalyst is getting closer to engine to have fast warm-up and wide-angled diffusers are often employed to connect the upstream exhaust pipe to the monolith. Therefore, the question arises as to the accuracy of porous medium approach based on one-dimensional laminar flow and model validation studies are essential if it is to become a useful design tool. From these reasons, this paper evaluates the prediction performance of porous medium and three-dimensional multichannel model by comparing with experimental results for understanding the limitation of porous medium approach and suggesting guidelines for the development of more accurate flow model. For evaluating each models, this work calculates the flow mal distribution and pressure drop across the monolith of an axisymmetric catalyst assembly under steady state condition. The results shows that porous medium model under-predicts flow maldistributions in the monolith by 6.4% at maximum and three-dimensional multi-channel model also under-predicts by 10.3% at maximum. From the results of this work, it can be concluded that modification of porous medium approach is strongly required to account of additional entrance effect and detailed modeling of monolith channels can not be alternative for more accurate flow simulation of auto-catalyst due to the inaccuracy Averaged Navier Stokes k-ε type turbulence model under abrupt change of length scale condition.
3리터급 DME 엔진용 DOC, LNT 후처리 장치 연구
장진영(Jinyoung Jang),이영재(Youngjae Lee),조종표(Chongpyo Cho),우영민(Youngmin Woo) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5
This study is developing aftertreatment system for DME engine. Modified DME engine, which is changed from diesel to current DME engine, was used for this research and is equipped common rail type injector and fuel supplying system. Aftertreatment system consists of DOC and LNT with reductant injector. DME is used as reducing agent. The maximum elimination of HC and CO emissions by DOC was over 80%. Especially reduction rate of CO was almost 100% at high exhaust temperature condition. The maximum diminution of NOx by LNT was over 50%. However HC slip was occurred by reducing agent. Second DOC was installed after LNT to decrease HC slip.Prototype aftertreatment system was made for vehicle.
미립화와 환경 2 : 대형 경유트럭의 휘발성유화합물(VOCs) 배출특성 연구
문선희 ( Sunhee Mun ),이종태 ( Jihwan Son ),손지환 ( Gyutae Park ),박규태 ( Heungmin Yoo ),유흥민 ( Changwan Yun ),윤창완 ( Jeongsoo Kim ),김정수 ( Jongtae Lee ) 한국액체미립화학회 2015 한국액체미립화학회 학술강연회 논문집 Vol.2015 No.-
WHO(World Health Organization) IARC(International Agency for Research on Cancer) has issued to consider diesel engine exhaust gas as an one of HAPs which has carcinogenic for human(Group 1). In this study, it was conducted to evaluate variety characteristics on changing of VOCs by aftertreatment systems, and the heavy duty diesel trucks were chosen as experimental vehicles. The results of the VOCs emission characteristics according to aftertreatment systems showed that compared to vehicles equipped with DPF, the vehicles equipped with SCR had 12.3%, 15.1%, 27.8%, and 22.2% lower BTEX emissions of Benzene, Toluene, Ethylbenzene, and Xylene, respectively. The emissions per pollutants were in the order of Toluene > Xylene > Ethylbenzene > Benzene > Styrene, and Toluene had the highest levels of emissions at 16.25 mg/km and 13.80 mg/km, respectively, for the vehicles equipped with DPF and SCR. The results of emission characteristics from vehicle speed, when the vehicle was operated at low speeds below 10.6 km/h, showed that due to incomplete combustion, emission was 75% higher. The results of analyzing the correlation between THC and BTEX showed a proportionate correlation with the rate of change of the emissions. As a result of analyzing the BTEX/THC ratio(%) for each of vehicle speed, Toluene was shown to have the highest proportion, and BTEX took up about 19.1% of the THC.
CFD를 활용한 비상발전기용 PM/NOX 동시저감장치의 유동특성 연구
방효원(Hyowon Bang),박기영(Giyoung Park),유준상(Junsang Yoo),이성욱(Seangwock Lee) 한국자동차공학회 2021 한국자동차공학회 부문종합 학술대회 Vol.2021 No.6
비상발전기용 디젤엔진은 소방기술기준규칙에 따라 7층 이상, 연면적 2천m² 이상의 건물에 설치하며 주 1회, 무부하 상태에서 30분 이상 운전점검을 수행해야 하는데, 이 과정에서 NO<sub>X</sub>, PM 등의 유해배출물이 다량 발생한다. 산업부 자료에 따르면 비상발전기의 PM 배출량은 1년에 770톤이며, 자동차 배출량의 80%에 이른다고 보고되었다. 현재 도로용 디젤엔진에 사용되는 DOC, DPF, SCR, AOC 등의 배기가스 후처리 시스템을 비상발전기용 엔진에 적용하여 유해배출물을 저감하고 있으나, 운전방식과 상태가 상이하여 비상발전기에 맞는 후처리 시스템 기술개발이 시급하다. 미국 환경청은 비도로용 엔진 배기가스 규제인 EPA 배출가스규제에서 비상발전기의 배출가스를 포함하고 있다. 하지만 비상발전기에 대한 환경규제가 없는 우리나라는 560kW급 이상 대형 비상발전기용 엔진에 대해서는 EPA의 최신 규제 단계인 Tier-4를 만족하는 PM/NOX 동시저감장치 기술이 없는 실정이다. 규제를 충족하기 위해서는 무부하 상태에서 후처리 시스템의 PM/NOX 저감 효율과 배압손실을 최적화해야 한다. 본 연구에서는 Tier-4 규제를 만족하는 560kW급 비상발전기용 후처리 시스템 연구를 진행하며, PM/NOX 동시저감장치는 SCR 전단에서 유동과 암모니아 균일도 확보를 중점으로 하였다. SCR 전단 유동균일도 분석은 CFD 해석법을 이용하여 후처리시스템의 NOX 저감방법에 대해 연구하였으며, 동시저감장치의 단면 형상, Urea 분사 방향, 믹서 Blade의 배치에 따른 균일도 변화를 분석하였다.
CFD를 활용한 DOC-DPF 조합의 유동 균질도 분석
김태훈,박성욱 한국분무공학회 2019 한국액체미립화학회지 Vol.24 No.3
Flow uniformity in aftertreatment system is an important factor in determining uniform catalytic reaction and filtration. In this study, variety types of DOC-DPF system design were analyzed to increase flow uniformity. For this analysis, ANSYS Fluent was used with porous media setup for DOC and DPF. Turbulent flow was modeled by standard k-ε model excepting porous media. Uniformity index was utilized to evaluate the flow uniformity quantitatively. Reference design showed low velocity region because two large vortex were generated before baffle. When radius of DOC-DPF system was increased, exhaust pressure acting on the inlet decreases and velocity distribution was shifted to one side. When inlet pipe was set to axial center of DOC-DPF system velocity distribution was symmetric. However, flow was not dissipated until the front end of DOC and showed higher uniformity index. When the volume of DOC was reduced while fixed volume of entire DOCDPF system and baffle plate is located downstream of the DOC-DPF system, there was improvement in uniformity index.
유럽시장 대응을 위한 촉매형 매연 여과 장치 매핑 전략
허행표(Haengpyo Heo),박성근(Sunggeun Park),이흥우(Hyeungwoo Lee),지요한(Yohan Chi),윤금중(Kumjung Yoon) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Increasing demands for clean air and better fuel consumption have led to the greater penetration of diesel passenger cars equipped with diesel particulate filters. In order to drastically reduce the particulate emission in all the engine operating conditions Catalyzed particulate filter has been developed for serial passenger cars. The exhaust gas temperature required for the filter regeneration was found to be achievable in all driving situation through a smart management of up to five multiple injections and air mass without an unacceptable increase of fuel consumption or noticeable change in vehicle drivability. The features and performance of the control system and engine, aftertreatment developed are presented in this paper.