• Journal of Mechanical Science and Technology
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• 제14권10호
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• pp.1168-1177
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• 2000

Hydrocarbon adsorber is considered as a promising technology to reduce cold start HCs in automotive exhaust gas. In this study, three in-line adsorber systems were tried to reduce the cold start emission. To check the basic characteristics of adsorber converters, surface areas, TPD and TP A were examined after a hydrothermal aging. Also idle engine bench was used to find the adsorption and desorption capabilities of the adsorber systems at cold start. Finally a practicability of the adsorber systems for the LEV achievement was checked with FTP test on a 2.0 D MIT vehicle. The results of this study indicate that hydrocarbon adsorber system is one of the promising passive technologies to meet the ULEV regulation.

• 한국분무공학회지
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• 제23권4호
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• pp.244-253
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• 2018

Recently, The ministry of Environment in korea have introduced Euro-6d temp which was strengthened at the same time as Europe. Small Light-duty passenger vehicles need the SCR system of after-treatment to meet enhanced emission regulations. However, SCR system has a low conversion efficiency in a low temperature less than 200 degree. In this study, the NOx conversion efficiency of SCR system was analyzed by installing a NOx sensors and a temperature sensors in a diesel vehicle. Also, in order to analyze the effect of the cold-start, the test was performed on the same RDE route and compared with the test of hot-start. As a result, SCR system has characteristics of low conversion efficiency under cold-start conditions.

• 한국추진공학회지
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• 제5권2호
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• pp.32-37
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• 2001

본 논문에서는 현재 시판되고 있는 주요 정유회사의 MTBE 가솔린을 이용하여 차량 배출 배기가스를 측정하였다. 배출 가스량은 차량 동력계상에 실제차량을 탑재하여 시험차량의 배기관에서 배출된 배출가스를 포집 하였으며, 우리나라의 공인배출가스 시험방법인 CVS-75 모드를 추적 주행하여 측정 하였다. CVS-75 모드는 cold start cycle, hot stabilized cycle 및 hot start cycle로 구성되며, 본 실험에서 분석한 배출가스는 일산화탄소, 질소산화물 및 탄화수소 등이다. 실험결과 배출 가스의 양에 있어서 근소한 차이만 보이고 있음을 알 수 있었다.

• 한국수소및신에너지학회논문집
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• 제26권4호
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• pp.363-368
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• 2015

Finding an alternative fuel and reducing environmental pollution are the main goals for future internal combustion engines. The purpose of this study is to obtain low-emission and high-efficiency by hydrogen enriched LPG fuel in a LPG engine. An experimental study was carried out to obtain fundamental data for the emit HC emission characteristics at cold start of pre-mixed LPG and hydrogen in a LPG engine with various fractions of hydrogen-LPG blends. To maintain equal volume ratio of fuel blend, the amount of HC was decreased as hydrogen was gradually added. The results showed that as hydrogen increases, in-cylinder pressure increased. Also emission of unburned hydrocarbon (HC) is sharply decreased.

• 한국분무공학회지
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• 제21권3호
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• pp.130-136
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• 2016

NOx and PM are important air pollutants as vehicle management policy aspect. Medium-duty truck is the main source of the pollutants although the vehicle market share is only 3.5%. National emission portion of NOx and PM form the mobile sourece are 14% and 16% respectively. In this study it was investigated that characteristics of air pollutants emission on medium duty truck equipped with EGR and SCR system. Vehicle's test reflected driving cycle on the chassis dynamometer, and applied test cycle was WHVC(World Harmonized Vehicle Cycle) mode. The test cycle include three segments, represent urban, rural and motorway driving. Based on the test results NOx, PM, HC were less emitted form SCR vehicle than EGR vehicle. And CO was less emitted form EGR vehicle than SCR vehicle due to CO oxidation reaction on DPF surface. And most air pollutants reduced as average vehicle speed increased. Pollutants were less emitted on motorway section than urban and rural sections. But highly NOx emission on motorway section was verified according to increased EGR ratio on fast vehicle speed. HC and CO additional emission was identified as 68%, 58% respectively during SCR vehicle's cold engine start emission test. NOx additional emission was detected by 24% on SCR vehicle's condition of engine cold start while not detected on vehicle equipped with EGR. SCR vehicle's additional NOx emission was derived from low reaction temperature during engine cold start condition. medium-duty truck emission characteristics were investigated in this study and expected to used to improve air pollutants management policy of medium-duty truck equipped with SCR & EGR.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.114-120
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• 2011

Fuel reforming technology for the fuel cell vehicles has been frequently applied to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this paper, syngas was feed to a 2.0 liter SI engine with MPI to improve exhaust emissions under cold start and early state of idle condition. Syngas fraction is varied to 0%, 10%, 25%, with various ignition timings. Exhaust emission characteristics and the exhaust system temperature were measured to investigate the effects of syngas addition on cold start. Result showed that HC emission could be dramatically reduced due to the fact that syngas has $H_2$ and no HC as components. The amount of $NO_x$ emission was decreased with the increase of syngas fraction. Because the dilution effect of $N_2$ and the retard of ignition timing reduces the peak combustion temperature inside the cylinder. Exhaust gas temperature was lower than that of gasoline feeding condition. Retarded ignition timing, however, resulted in increased exhaust gas temperature approximated to gasoline condition. It is supposed that the usage of syngas in an SI engine is an effective solution to meet the future strict emission regulations.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.39-47
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• 2003

UEGI (Unburned Exhaust Gas Ignition) is an alternative method for fast light-off of a catalyst. It ignites the unburned exhaust mixture using two glow plugs installed in the upstream of the close-coupled catalysts. In addition, a hydrocarbon adsorber was applied to the UEGI, for more effective reduction of HC emission. Engine bench tests show that the CCC reaches the light-off temperature laster than the baseline exhaust system and HC and CO emissions are reduced significantly during the cold start. From the vehicle test, it was observed that a few amount of HC emission was reduced even the catalysts were aged. It is expected to develop a solution kit applicable to a new vehicle or used one, to meet the emission regulation

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2002년도 추계학술대회 논문집
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• pp.233-234
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• 2002

도시대기오염의 주요 배출원으로 알려진 자동차에서 배출되는 VOCs는 인체에 유해할 뿐만 아니라 대기 중에서 질소산화물(NOx)과 함에 광화학반응을 통한 오존 둥 2차 오염물질인 광화학산화물을 형성하는 전구물질로 작용하기 때문에 환경학적, 보건학적으로 매우 큰 영향을 미친다. 이러한 자동차 배출 VOCs가 오존생성에 미치는 영향에 대한 연구는 갈수록 증가하고 있는 대기중 오존 농도 심화현상의 규명과 대기질 개선을 위한 기초자료로서 매우 그 필요성이 더해가고 있다. (중략)

• 대한환경공학회지
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• 제33권4호
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• pp.223-230
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• 2011

EMEP/EEA Emission Inventory Guidebook에 의하면 자동차 주행에 따른 총 대기오염물질 배출량을 Hot Start와 Cold Start로 구분해 산출하도록 하고 있다. 본 연구에서는 이러한 자동차 주행주기 특성을 감안하여 교통사업의 타당성 분석 시환경비용절감 편익의 현실적인 산정방안에 대해 검토하였다. 이를 위해 교통수요 분석모형(EMME/3)을 이용하여 분석영향권내 모든 링크단위의 교통량과 통행속도 자료를 활용하는 Tier 3 방식으로 환경오염 물질을 선출하였다. 본 연구에서 제안된 방법론의 적용성 검토를 위해 현재 계획중인 철도 투자평가사업에 적용하였으며, 적용결과 환경부문의 편익이 기존 대비 약 30% 정도 증가하는 것으로 나타났다. 향후 본 연구에서 제안한 방법론이 투자평가과정에서 적용된다면 철도와 같은 친환경 교통수단의 투자활성화에 기여할 것으로 기대한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.796-801
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• 2001

During cold operation period, fuel injection system directly contributes the unburned hydrocarbon formation in spark ignition engines. The relationship between injection parameters and HC emission behavior was investigated through a series of experiments. Spray behavior of port fuel injectors was characterized through a quantitative evaluation of mass concentration of liquid fuel by a patternator and PDA. 6-hole injector was found to produce finer spray than single hole one. Using a purpose-built test rig, the wall wetting fuel was measured, which was mostly affected by wall temperature. Varying coolant temperature($20{\sim}80^{\circ}C$), HC emissions were measured in a production engine. With respect to the different types of injectors, HC emission was also measured. In the 6-hole injector application, the engine produced less HC emission in low coolant temperature region. Though it produces much more amount of wetting fuel, it has the advantages of finer atomization quality. In high coolant temperature region, there was little effect between different types of injectors. The control schemes to reduce HC emissions during cold start could be suggested from the findings that the amount of fuel supply and HC emission could be reduced by utilizing fine spray and high intake wall temperature.