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바이오디젤유 사용 디젤엔진의 나노입자와 배출가스 배출 특성
김화남(Hwanam Kim),박성용(Sungyong Park),최병철(Byungchul Choi) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
We measured emission characteristics of CRDI diesel engine equipped with a warm-up catalyst(WCC). Experimental parameters adopted a neat diesel fuel, a blend of diesel fuel with 5, 20% biodiesel. The experiments were carried out to measure the emission and engine performance according to ECE R49 13-mode cycles. The maximum torque with biodiesel blend fuel is slightly lower than that of neat diesel fuel at high-load conditions. Smoke was decreased more than 2-18% in the entire the 13-mode cycles. HC and CO emissions of the biodiesel blended fuel were slightly decreased, and mean conversion efficiencies of HC and CO on the WCC were achieved about 50-80% in the 13-mode. However NOx emission of diesel fuel with 20% biodiesel increased by 1.7%. From the measurement by the Scanning Mobility Particle Sizer(SMPS), the total number and total mass of the nano-sized particles using the diesel fuel with 20% biodiesel in the range 10.6㎚-385㎚ were decreased about 10% and 25%, respectively.
디젤 연료의 황농도에 따라 배출되는 입자상물질의 산화촉매에서 반응특성
김화남(Hwanam Kim),성용하(Yongha Sung),정길성(Kil Sung Jung),강한용(Hanyong Kang),최병철(Byungchul Choi),임명택(Myung Taeck Lim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Diesel particulate matters are one of a major harmful component of the emission under strict regulations. Diesel oxidation catalyst (DOC) is using to reduce hydrocarbon and carbon monoxide in current diesel engines. The objectives of this study are to further understand the formation characteristics of nano-particles in nuclei mode, for the purpose we examined formation of nano-particle with various sulfur concentrations in diesel fuel in both of a common-rail diesel engine and a boiler for household heating equiped with DOC. Experimental parameters adopted equivalence ratio, dilution air temperature, fuel injection pressure and engine speed. The particle size distribution and the number concentration were measured by SMPS. PM nano-particle number in boiler exhaust gas was increased by diesel fuel with 500 ppm sulfur, and when the exhaust gas temperature is more than 300℃, the particles range of 20 to 40 ㎚ increased greatly in the rear of the DOC. Number of the particle smaller than 30 ㎚ size increased as the sulfur concentration in the diesel fuel increased in the common-rail diesel engine.
정길성(Kil Sung Jung),김화남(Hwanam Kim),성용하(Yongha Sung),최병철(Byungchul Choi),임명택(Myung Taeck Lim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
HCCI engines exhaust gas that contains THC and CO at a level comparable to the gasoline engines. Development of exhaust treatment devices like DOC's with high conversion efficiency especially at low temperature is therefore very important for commercialization of HCCI engines. Experimental DOC's are designed and fabricated in this study using 600 cpsi monolith, coated with either a L type or H type wash coat. Different amount of platinum is impregnated on the washcoat layers before canning and performance tests. Experimental results show that DOC's with low-temperature type wash coat have higher HC conversion efficiency at low exhaust gas temperature in comparison with those of high-temperature type wash co at and heavier Pt loading. DOC's with heavier Pt loading show higher HC conversion efficiency at exhaust temperature over 300℃. CO conversion is above 90 % on all types of DOCs as long as the exhaust temperature stays over 200 ℃.
성용하(Yongha Sung),김화남(Hwanam Kim),정길성(Kil Sung Jung),임명택(Myung Taeck Lim),최병철(Byungchul Choi) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Exhaust treatment devices are added to the diesel engines as stricter regulations are introduced worldwide. The objectives of this study arc to further understand the characteristics of exhaust nanoparticles from a common-rail diesel engine equipped with DOC, DPF or CPF, and to analyze the effects of ultra-low sulfur diesel fuel on the particulate emissions. Diesel fuel with sulfur supplied in engine under the conditions of various equivalence ratio, fuel supply pressure and engine speed. The particle size distribution is measured by an SMPS to investigate the influences of sulfur content of the fuel, fuel injection pressure, fuel-air equivalence ratio, engine speed and load, types of exhaust treatment devices etc.
De-NOx Characteristics of a Combined System of LNT and SCR
서충길(Choong-Kil Seol),김화남(Hwanam Kim),최병철(Byungchul Choi) 한국자동차공학회 2011 한국자동차공학회 지부 학술대회 논문집 Vol.2011 No.5
The purpose of this paper is to investigate de-NOx performance of a combined system of LNT and SCR with fresh or hydrothermally aged. The NOx conversion of the LNT decreased with SV increased in range of 350℃ or lower temperature, the formation quantity of NH₃ increased as SV increased in the same lower temperature range. The NOx conversion of the SCR with SV=14,000 1/h showed 95% at 320℃, the effect of SV on the NOx conversion was not so much. The NOx conversion of the combined system of LNT and SCR with fresh catalysts appeared maximum value of 70% and hydrothermal aging at 900℃ decreased about to 25% below range of 300℃. And the hydrothermally aged catalysts shown trends of the reduction of NOx conversion and the increase of NH₃ slip due to the reduction of residence time according to SV increase.
공간속도에 따른 LNT+SCR 복합시스템의 de-NO<SUB>x</SUB> 특성
서충길(Choong-Kil Seo),김화남(Hwanam Kim),최병철(Byungchul Choi) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
The purpose of this paper is to investigate the adsorption and desorption characteristics of only LNT and SCR catalysts with respect to SV(Space Velocity) and the de-NOx performance of a combined system of LNT+SCR with fresh or hydrothermally aged. The adsorption according to SV of the LNT catalyst was about 1,000sec to reach 500ppm of NOx at SV=14,000 1/h. The ratio of NO₂/NOx on the LNT was increased as SV decreased. The physically and chemically absorbed NH₃ on the SCR catalyst desorbed in same concentration though various SV values. The NOx conversion of the LNT decreased with SV increased in range of 350℃ or lower temperature, the formation of NH₃ increased as SV increased in the same lower temperature range. The NOx conversion of the SCR with SV=14,000 1/h showed 95% at 320℃, the effect of SV on the NOx conversion was not so much. The NOx conversion of the combined system of LNT and SCR with fresh catalysts appeared maximum value of 70% at 250℃, whereas the NOx conversion of the combined system with hydrothermally aged catalysts at 750 or 900℃ decreased about to 25% below range of 300℃. And the hydrothermally aged catalysts shown trends of the reduction of NOx conversion and the increase of NH₃ slip due to the reduction of residence time according to SV increase.
박성용(Sungyong Park),김화남(Hwanam Kim),최병철(Byungchul Choi) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
Homogeneous Charge Compression Ignition (HCCI) engine concept allows reducing both NOx and particulates simultaneously, it appears as a promising way to meet the next environmental challenges. Unfortunately, HCCI combustion often increases CO and HC emissions. Conventional oxidation catalyst technologies may not be able to convert these emissions because of the saturation of active catalytic sites. 3 kinds of OC(oxidation catalyst) with different amount of Pt and Pd were used. It was found that all types of OC have over 90% CO conversion efficiencies at 170℃. In the presence of water vapor, CO conversion was increased but C₃H? conversion was decreased. 2Pt/Pd catalyst was better in thermal aging than Pt only catalyst.
박성용(Sungyong Park),김화남(Hwanam Kim),최병철(Byungchul Choi) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.2
HCCI 엔진은 배출가스 중 PM과 NOx 가 저감되나, 일반적으로 상용디젤 엔진보다 HC, CO 가 증가하는 특성을 보인다. 특히 과도한 HC 에서 발생하는 SOF 로 인해 total PM 에 영향을 미친다. 이는 HCCI 엔진에서 DOC 를 통한 HC 저감이 중요하며 HC 의 정화성능이 우수한 OC 의 개발이 필요하다. 실험은 모델가스를 이용하여 2Pt/1Pd 의 충전량이 다른 3 종의 OC(600cpsi cordierite)를 가지고 수행하였다. OC 에서 HC, SV, H₂O, O₂의 조건을 달리하여 OC 성능특성을 LOT50에서 평가하였다. 그 결과 CO 는 170℃에서 3 종의 촉매 모두 90% 이상의 정화특성을 나타내었고 Pd 가 충전 된 OC 는 열화 된 후 Pt 만충전 된 OC 보다 우수한 내구특성을 나타내었다. Fresh 와 aged 된 OC 에서 SV 의 증가 및 H₂O 의 반응참여는 LOT50성능이 낮아지는 결과를 나타내었다. The Homogeneous Charge Compression Ignition (HCCI) engine concept allows for both NOx and particulate matter to be reduced simultaneously, and it is a promising way to meet the next environmental challenges. Unfortunately, HCCI combustion often increases CO and HC emissions. The development of oxidation catalyst (OC) requires high conversion efficiency for CO and HC at low temperature. Conventional oxidation catalyst technologies may not be able to convert these emissions because of the saturation of active catalytic sites. The OC used in this study was 600 cpsi cordierite. Three kinds of OC with different amounts of Pt and Pd were used. The influence of the space velocity (SV), H₂O and O₂ concentration was also studied. All types of OCs were found to have over 90% CO conversion efficiencies at 170℃. When in the presence of water vapor, CO conversion was increased, but C₃H? conversion was decreased. The performance of the OC was not influenced by initial the HC concentration. The 2Pt/Pd catalyst was better in terms of thermal aging than the Pt-only catalyst. The LOT50 of both fresh and aged OC was increased with increasing SV and with the presence of H₂O.
DME 개질용 Cu/Al₂O₃ 촉매에 제올라이트 혼합이 수소생성과 SR+LNT의 de-NOx 성능에 미치는 영향
박성용(Sungyong Park),김화남(Hwanam Kim),최병철(Byungchul Choi) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5
The aim of this study is development of SR(steam reforming) catalyst to improve performance of de-NOx catalytic system for DME engines. The SR catalysts (Cu-based) were used r-Al₂O₃ or r-Al₂O₃+Modenite 10% prepared by an impregnation method and the LNT used as a commercial catalyst. As a result of experiments, Cu10%/r-Al₂O₃+modenite 10% showed H₂ production of 58% compared to that of 10% over the Cu10% /r-Al₂O₃ catalyst at 300℃. When H₂ generated by the Cu10%/r-Al₂O₃+modenite 10% catalyst was used as LNT reductant, the NOx conversion was improved by about 15% compared to the LNT used alone.