• 대한기계학회논문집B
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• 제32권4호
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• pp.266-274
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• 2008

The need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as Liquefied Petroleum Gas(LPG) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to apply it for the conventional gasoline or diesel fuel pump directly. In this study, experiments are performed to get performance and efficiency of the fuel pump at different condition as temperature, rotating speeds, composition of fuel. The characteristics of fuel pump is affected by cavitation due to the variation of temperature and composition.

• 한국분무공학회지
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• 제11권3호
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• pp.161-167
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• 2006

As the exhaustion of petroleum resources and air pollution problems are getting serious recently, there are growing interests in premixed diesel engines which have the potential of achieving a more homogeneous mixture near TDC compared to conventional diesel engines. Early studies have shown that the fuel injection frequency and spray angle affected the mixture formation and combustion in a HCCI(Homogeneous Charge Compression Ignition) engine. Therefore, the purpose of this study is to investigate the relationship between combustion and mixture formations by injection timing and frequency using a narrow angle injector, NADI (Narrow Angle Direct Injection). In this study, we found that the fuel injection timing and injection frequency affect the mixture formations and then affect combustion in the HCCI engine.

• 한국분무공학회지
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• 제7권2호
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• pp.16-21
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• 2002

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. This study addresses the analysis of the LPG spray behavior near injection nozzle. The LPG spray photographs are compared with sprays of diesel fuel at the same conditions. The LPG spray photos show that the dispersion characteristic depends very sensuously on the ambient pressure soon after injection. The spray angle is very wide in a low ambient pressure condition until the saturated pressure at this test condition, but the angle value is quickly reduced at the condition over the pressure.

• 한국응용과학기술학회지
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• 제33권4호
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• pp.676-685
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• 2016

본 연구는 폴리스타렌(PS) 수지의 유화공정 효율성 향상을 위해 저온열분해 회분식 반응기를 이용하여, 단일 PS 수지와 Co 및 Mo 촉매를 각각 첨가한 PS 수지를 반응온도(425, 450, $475^{\circ}C$), 반응시간(20~80분, 15분 간격), 촉매 농도변화에 따른 PS수지의 액화생성물 전환율을 측정하였다. 최적의 열분해 조건은 반응온도 $450^{\circ}C$, 반응시간 35분으로 판단되며, 전환된 액화생성물의 주요 성분은 GC/MS 분석결과 스타이렌 및 벤젠유도체가 대부분으로 나타났다. 생성물은 산업통상자원부에서 고시한 증류성상 온도에 따라 가스, 가솔린, 등유, 경유, 중유로 분류하여 그 수율을 측정하였다. 그리고 $450^{\circ}C$ 반응온도에서 촉매 사용에 따른 전환율은 Co 촉매 > Mo 촉매 > 무촉매 순이었으며, 생성물 중 가스, 등유, 경유수율은 Mo 촉매, 가솔린은 무촉매, 중유는 Co 촉매에서 우수한 것으로 나타났다. Co 및 Mo 촉매 혼합 농도별 전환율 및 열분해 생성물 수율은 Co 촉매 100% 사용 시 가장 우수한 것으로 판단된다.

• 대한환경공학회지
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• 제37권1호
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• pp.69-72
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• 2015

토양을 유류로 오염시킬 때 토양조성 및 유류 주입량 등이 토양 TPH 분석결과에 미치는 영향을 연구하였다. 동일한 양의 경유를 조성이 다른 토양과 혼합한 후 토양 TPH를 분석한 결과 토양에 점토 및 유기물함량이 존재한다면 모래로 구성된 토양에 비해 토양 TPH 결과가 적게 얻어졌다. 점토함량이 높은 토양일수록 분석전처리 시 토양이 굳는 현상이 발생하면서 실제 값보다 적은 TPH 결과치를 나타내었다. 토양 내 유기물 함유량 변화에 따른 토양 TPH 측정실험에서 유기물 함량이 높아질수록 토양 TPH 측정농도는 증가되지만, 극히 높은 18% 유기물함량조건에서는 전처리 및 용매추출의 불확실성으로 인해 오히려 낮은 TPH 분석 결과를 보여주었다. 경유 주입량에 따른 토양 TPH 농도 변화 실험 결과 경유 주입량이 많아질수록 높은 TPH 분석결과를 나타내었다. 동일한 양의 경유와 휘발유를 주입하여 유종에 따른 토양 TPH 분석결과 휘발유는 오염 즉시 휘발하여 극히 낮은 TPH 농도를 보여주었다. 본 연구결과는 차후 인위적 유류오염 토양 제조과정에서 TPH 농도를 가늠하거나 부지 정밀조사 결과 유류 유출량 등을 예측하는데 기초자료로 활용할 수 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제9권4호
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• pp.24-31
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• 2004

유류오염토양을 건설재료로 재활용할 수 있는 방안으로써 Cold Mix Asphalt(CMA) 처리를 제시하였고 디젤 및 디젤화합물로 오염된 토양의 CMA 처리특성을 고찰하였다. 양이온성 또는 음이온성 또는 비이온성 계면활성제를 함유하고 있는 5가지 아스팔트 이멀젼을 이용해서 디젤 오염토양의 처리능을 고찰한 결과 첨가된 계면활성제의 차이에 의한 성능의 차이는 확연하게 드러나지 않았으나, 토양과의 친밀성 및 흡착계수를 고려하여 Lauryl Dimethyl Benzyl Ammonium Chloride (LDBAC)를 포함한 이멀젼을 오염토양 처리에 적합한 아스팔트 이멀젼으로 선정하였다. 아스팔트 이멀젼 LDBAC에 의한 세가지 디젤화합물의 처리능은 docosane, pentadecane, undecane의 순으로 높은 것으로 나타났다. 아스팔트 이멀젼 LDBAC를 이용하여 CMA처리된 토양에 대한 용출실험결과 비교적 고농도인 10,000 mg/kg 의 디젤로 오염된 토양도 CMA처리 가능함을 확인하였다. 공시체로부터 디젤의 용출은 초기 4일까지는 확산에 의한 거동을 보여 주었고 그 이후로는 용출속도가 감소하여 총 용출가능양의 $50\%$ 이상이 유출되었다고 판단되는 depletion의 거동을 보여 주었다. CMA처리된 오염토양으로부터 3가지 디젤화합물의 총용출량은 undecane > pentadecane > docosane의 순서로 높은 것으로 나타났으며, pentadecane의 경우 CMA 처리시 양생속도가 상대적으로 더딘 것으로 밝혀졌다.

• Tribology and Lubricants
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• 제34권6호
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• pp.292-299
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• 2018

The objective of this research is to investigate the impact of engine oil aging on PM(Particulate Matter), exhaust gases, and DPF. It is widely known that the specification of a lubricant and its consumption in an ICE considerably influences the release of regulated harmful emissions under normal engine operating conditions. Considering DPF clogging phenomena associated with lubricant-derived soot/ash components, a simulated aging mode is designed for DPF to facilitate engine dynamometer testing. A PM/ash accumulation cycle is developed by considering real-world engine operating conditions for the increment of engine oil consumption and natural DPF regeneration for ash accumulation. The test duration for DPF aging is approximately 300 h with high- and low-SAPs engine oils. Detailed engine lubricant properties of new and aged oils are analyzed to evaluate the effect of engine oil degradation on vehicle mileage. Furthermore, physical and chemical analyses are performed using X-CT, ICP, and TGA/DSC to quantify the engine oil contribution on the PM composition. This is achieved by sampling with various filters using specially designed PM sampling equipment. Using high SAPs engine oil causes more PM/ash accumulation compared with low SAPs engine oils and this could accelerate fouling of the EGR in the engine, which results in an increase in harmful exhaust gas emissions. These test results on engine lubricants under operating conditions will assist in the establishment of regulated and unregulated toxic emissions policies and lubricant quality standards.

• 에너지공학
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• 제15권3호
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• pp.139-145
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• 2006

The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.8 to 1.3, and the ignition timing was controlled to be at MBT (minimum spark advance for best torque)

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.131-134
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• 2004

Several physical and chemical methods have been used for remediation contaminated by oils. However the cost was very high and secondary pollution rose during treating. The purpose of this study was to comprision TPH (total petroleum hydrocarbon) removal from artificially contaminated soil by diesel with and without seeding anaerobic digested sludge. After 120 days of overall at 35$^{\circ}C$, removal efficiency of TPH with seeding sludge was 2-3 times higher than blank. Also, the more amount seeding sludge, TPH removal efficiency and CH$_4$ content more obtained. It was sad that seeding of anaerobic digested sludge was a good method for enhancing TPH removal efficiency without increasing operating cost. Sulfate, nitrate-reducing, methanogenic condition were evaluated for alkane, isoprenoid as target contaminated soil.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1203-1210
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• 2001

This study was carried out to develop an engine for off-road vehicles especially for farm tractors using the liquefied petroleum gas (LPG) which is known as a source of energy having good potential of substitute fuel for diesel engine because of its economical advantage and low pollutant materials after combustion. The study was focused on develop an engine of high in specific power output, low in specific fuel consumption and emission of pollutants. A series of teat was dope on the engine - various laboratory tests to analyze performance of the engine and actual field tests with the engine installed on a farm tractor as a power source.