• 한국자동차공학회논문집
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• 제7권7호
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• pp.104-112
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• 1999

An experimental study for reducing the exhaust hydrocarbon emission at spark ignition engine using timed secondary air injection is carried out . In this study, secondary air injection timings and durations are controlled to decrease the hydrocarbon emission and to increase exhaust gas temperature at cold and warm-up engine conditions. The hydrocarbon reduction rate and exhaust gas temperature are compared between timed secondary air injection and continuous air injection. The optimum secondary air injection timing for reducing the hydrocarbon emission is at the exhaust valve open timing. At some engine conditions , the hydrocarbon emissions are decreased to 10% of engine raw values and exhaust gas temperatures increase by 20$0^{\circ}C$ with times secondary air injection . Timed secondary air injection has more hydrocarbon reduction rate that continuous secondary air injection except some engine conditions.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.507-510
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• 2007

Piston cores retrieved from the western Ulleung Basin, East Sea were analyzed to examine the potential for hydrocarbon generation and to determine the hydrocarbon indicators. 2D multi-channel reflection seismic and Chirp data were also investigated for mapping and characterizing the geophysical hydrocarbon indicators such as BSR (bottom simulating reflector), blank zone, pock-mark etc. High organic carbon contents and sedimentation rates that suggest good condition for hydrocarbon generation. High pressure and low temperature condition, and high residual hydrocarbon concentrations are favor the formation of natural gas hydrate. In the piston cores, cracks generally oriented to bedding may indicate the gas expansion. The seismic data show several BSRs that are associated with natural gas hydrates and underlying free gas. A number of vertical to sub-vertical blank zones were well identified in the seismic sections. They often show the seismic pull-up structures, probably indicating the presence of high velocity hydrates. Numerous pockmarks were also observed in the Chirp profiles. They may indicate the presence of free gas below the hydrate stability zone as well.

• Korean Chemical Engineering Research
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• 제53권4호
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• pp.496-502
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• 2015

탄화수소 이슬점은 천연가스 응축형태를 특성화하는 가장 일반적이고 자주 이용되는 물성으로 가스 품질 사양의 중요한 항목이다. 탄화수소 이슬점은 미량의 고탄화수소 성분에도 매우 민감한 것으로 알려져 있어, 특히 천연가스를 공급하는 가스 회사 입장에서는 기존 합의된 가스 사양을 만족하는 것 뿐만 아니라, 발생된 탄화수소 응축물에 의해 운영설비 및 안전에 심각한 문제를 일으킬 수 있으므로 탄화수소 이슬점을 정확하게 구하는 절차를 확립하는 것이 중요하다. 본 연구에서는 실제 현장조건 하에서 탄화수소 이슬점을 측정하기 위해 냉각 거울 방식의 이슬점 측정기를 설치, 운영하였으며, 측정된 이슬점 온도는 가스분석기에 의해 분석된 조성 및 천연가스 산업계에서 인정된 상태방정식을 이용하여 계산된 이슬점 온도와 비교하였다. 시험 결과 탄화수소 이슬점 측정기는 매우 안정되게 이슬점을 측정하였으며, 이슬점 측정기를 검증하기 위한 시험 가스로는 순수 프로판 가스가 적정하였다. 제조 표준가스 및 실제가스의 측정결과를 가스분석기에 의한 간접 측정 결과와 비교시에도 적정한 범위 내에서 일치하는 것을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.610-612
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• 2008

Piston cores retrieved from the eastern part of the deep-water Ulleung Basin were analyzed to access the potential of hydrocarbon gas generation and natural gas hydrate (NGH) formation. Seismic data acquired in the study area were also analyzed to determine the presence of hydrocarbon gas and/or NGH, and to map their distribution. Core analyses revealed high total organic carbon (TOC) contents which favor hydrocarbon generation. The cores recovered from the southern study area showed the sufficient residual hydrocarbon gas concentrations for the formation of significant NGH. These cores also showed the cracks developed parallel to the bedding that suggest significant gas content in situ. A number of seismic blanking zones were observed on seismic data. They are identified as vertical to sub-vertical chimneys caused by the upward migration of pore fluid or gas, and containing of free gas and/or NGH. Often, they are associated with velocity pull-up structures that are interpreted to be the result of high-velocity NGH. The seismic data also showed several bottom-simulating reflectors (BSRs) that are associated with overlying NGH and underlying free gas. The distribution of blanking zones and BSRs would be impacted by the lateral differences of upward methane fluxes.

• 오토저널
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• 제13권3호
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• pp.25-31
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• 1991

The formation process of hydrocarbon emissions was investigated in SI engine. The time- resolved concentrations of hydrocarbon emissions were measured using a high gas sampling valve and a gas chromatography. The gas was sampled at exhaust port, or the position of spark plug, or the wall of combustion chamber. The experiments were conducted using the Alpha engine of Hyundai Motor Company. The fuel used was methanol or propane. It was found that the effect of the quenching layer of combustion chamber wall on hydrocarbon emissions was not significant. The increasing rate of hydrocarbon concentration at combustion chamber wall near crevice and oil layer after flame was reached was much higher than that at the position of spark plug. The hydrocarbon concentrations at exhaust port had two peak values just after opening exhaust valve and just before closing it.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.108-121
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• 1998

Using gas chromatography, the light hydrocarbon emissions were analyzed from SI engine fueled with methane and liquified petroleum gas(LPG), and the effects of fuel and engine operating condition were discussed. For this purpose, 14 species of light hydrocarbon including 1, 3-butadiene were separated, calibrated with standard gas, and measured from undiluted emissions. The brake specific hydrocarbon emission(BSHC) and ozone forming potential(BSO)3 were calculated and discussed with the changes of fuel, engine speed, load, fuel/air equivalence ratio, coolant temperature, and spark timing. As a result, exhaust emission was composed of mainly fuel composed of mainly fuel comp- onent and other olefin components of similar carbon number. The olefin components such as ethylene and propylene determine most of the ozone forming potential. The fraction of fuel component in total hydrocarbon emission was bigger with methane fuel than with LPG fuel. Also fuel fraction increased at high speed or high speed or high temperature of exhaust gas, and to lesser extent with high coolant temperature and retarded spark. However, the effect of equivalence ratio had different tendency according to fuels.

• 대한기계학회논문집B
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• 제34권4호
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• pp.417-422
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• 2010

1.7L 커먼 레일 직접 연료분사 디젤엔진과 초저유황 스웨덴 디젤 연료를 이용하여 연료분사시기 8.5CA BTDC~0.5CA BTDC 와 배기가스 재순환률 37%, 43%, 48% 영역에서 실험을 수행하였다. 각각의 배기가스 재순환률에 대하여 연료분사시기가 지각됨에 따라 매연과 질소산화물이 동시에 저감되나 탄화수소와 일산화탄소는 증가하는 저온 디젤 연소영역에 있음을 확인하였다. 탄화수소를 가스크로마토그래프와 불꽃 이온 검출기를 사용하여 종 분석을 수행하였으며, 연료분사시기가 지각될수록, 그리고 배기가스 재순환률이 증가할수록 Partially burned HC, 알켄의 비율이 증가하였다. Partially burned HC 중에서 에텐이, 그리고 Unburned HC 중에서 노말 운데케인이 가장 많이 배출되었다. 이 두 개의 탄화수소 종은 촉매 연구에 사용되는 벤치 플로우리액터 시험에서 대표적인 탄화수소 종으로 사용할 수 있다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.33-42
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• 2002

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated fur direct injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has three kinds of mixed ratio. And, it was tried to analyze not only total hydrocarbon but individual hydrocarbon components from Cl to C6 in exhaust gas using gas chromatography to seek the reason far remarkable reduction of smoke emission. This study was carried out by comparing the chromatogram with diesel fuel and diesel feel blended DGM(diethylene glycol dimethyl ether) 5%. The results of this study show that individual hydrocarbon(C1∼C6) as well as total hydrocarbon of oxygenated fuel is reduced remarkably than that of diesel fuel.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.112-118
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• 2001

In this study the leakage current measurement method based on a porous ceramic is applied to check the conductive substance caused by the ionized particles. By using engine and chassis dynamometer and an experiment vehicle, in which the hydrocarbon sensor (HC sensor) was exposed to the exhaust gas to create the electrical signal, the HC sensor in the exhaust line checked the conductive ions in emission gas. Generally the output electrical signal of HC sensor is followed with amount of hydrocarbon in the experiments in cold start and operation. By combining the electrical signal, a measure of conductivity of exhaust gas with hydrocarbon can be provided by OBD (On Board Diagnosis) II and EMS (Engine Management System).

• 동력기계공학회지
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• 제4권3호
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• pp.12-18
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• 2000

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions with various methods of diesel engine that influenced the environment strong. In this paper, the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine have been investigated by the quantitative analysis of the hydrocarbon $C_1{\sim}C_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and three kinds of mixed fuels. One is the diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. Another is the diesel fuel blended DEE(diethyl ether) 25% and DMC(dimethyl carbonate) 10%. The results of this study show that the hydrocarbon $C_1{\sim}C_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed.