• 한국수소및신에너지학회논문집
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• 제33권1호
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• pp.77-84
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• 2022

The experimental work has been carried out for the study of pyrolysis of oil samples used in industrial and utility boilers in Korea. For five oil samples, the characteristics of pyrolysis have been investigated with a thermogravimetric analyzer (TGA), and their kinetic parameters were obtained and compared each other. The rate order of pyrolysis rate for five oils were as follows: by-product fuel oil, pyrolysis oil, diesel, a heavy oil and refined oil. The pyrolysis of refined oil has been successfully described by the three step, first order reaction model while the single step reaction model has been used for other oils. For the reaction temperature over 550 K, the reactivity of refined oil was very poor compared with other oils.

• Journal of Biosystems Engineering
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• 제38권3호
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• pp.208-214
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• 2013

Purpose: Performances of a tractor diesel engine fueled by three different animal fats biodiesels were evaluated comparing with light oil tractor in terms of power, fuel consumption rate, exhaust gases, particulate matter amount and field work capacity. Methods: Animal fats based on pig biodiesel were manufactured manually and tested for its engine performance in the tractor diesel engine and fuel adoptability in the field works. Four different fuels, three different content of biodiesel (BD20, BD50, BD100) and light oil, were prepared and tested in the four strokes diesel engine. Power output, fuel consumption rate and exhaust gases of the four fuels in the diesel engine were compared and discussed. Results: Power output of light oil engine was the greatest showing 5.3% difference between light oil and BD100, but 0.37% better power than BD20 engine power. Less exhaust gases of $CO_2$, CO, $NO_X$ and THC were produced from animal fats biodiesel than light oil, which confirmed that biodiesel is environmental friendly fuel. For fuel adoptability in the tractor, biodiesel engine tractor showed its fuel competitiveness comparing with light oil for tractor works in the faddy field. Conclusions: With four different fuel types of animal-fats biodiesel, performances of a four cylinder diesel engine for tractor were evaluated in terms of power, exhaust gases, particulate matters (PM) and field work capacity. No significant differences observed in the engine performances including power output and exhaust gases emission rate. No significant power difference observed between the various fuels including light oil on the engine running, however, amounts of noxious exhaust gases including $CO_2$ and $NO_X$ decreased as biodiesel content increased in the fuels. Field performances of animal-fats biodiesel tractor were investigated by conducting plowing and rotary operation in the field. Tilling and rotary performance of light oil tractor and BD20 tractor in the field were compared, in which about 10% travelling speed difference on both operations were monitored that showed light oil tractor was superior to BD20 tractor by 10%. Animal-fats can be an alternative fuel source replacing light oil for agricultural machinery and an environmental friendly fuel to nature.

• Journal of Advanced Marine Engineering and Technology
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• 제39권4호
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• pp.381-386
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• 2015

최근에 환경오염 문제와 대체에너지 문제에 많은 관심을 가지고 있다. 디젤기관은 세계적으로 연료의 경제성 때문에 사용이 증가할 것이다. 그러므로 선박용기관의 대기오염 문제도 여러 분야에서 큰 관심사가 되고 있다. 화석연료로 부터 배출되는 유해 배기가스를 줄이기 위하여 대체연료기술이 개발되고 있다. 이러한 신재생에너지의 바이오디젤연료는 기존 디젤연료를 대체할 친환경 에너지로 각광을 받고 있으며, 일정한 비율로 디젤연료와 혼합하면 기존 디젤기관에 개조 없이 사용가능하다. 본 연구에서 바이오디젤연료가 선박디젤기관의 연소특성에 미치는 영향을 분석하기 위하여 폐식용유로부터 제조된 바이오디젤유를 엔진에 적용하여 실험을 수행하였다. 폐식용 성분에는 세탄가와 점도가 높은 성분이 있고, 탄소함유량이 적으면서 산소함유량이 잔존하고 있다. 연구 결과 연료소비율은 증가하고, 압력, 압력상승율 및 열발생율은 감소하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권1호
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• pp.8-12
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• 2015

비에스테르화 바이오 디젤유는 에스테르화 공정을 거치지 않기 때문에 공정에 드는 비용이 절감되며 경유에 5%로 혼합하여 전자제어 분사식 디젤엔진에 사용할 경우 에스테르화 바이오 디젤유보다 경유에 더 유사한 성능을 나타내었다. 이러한 연구를 바탕으로 경유에 5% 혼합된 비에스테르화 바이오 디젤유를 전자제어 분사식 디젤엔진에 적용하기 위해서는 성능 최적화가 필요하다. 본 연구에서는 비에스테르화 바이오 디젤유의 성능 최적화를 위한 기초 실험으로 연료소비율, 질소산화물 및 도시평균유효압력을 반응치로 정하고 제어 가능한 6가지 인자에 대해서 그 영향력을 평가하고자 부분요인배치법을 이용하여 25%와 50%의 부분 부하에서 실험을 수행하였다. 그 결과 6가지 인자 중 분사시기 및 커먼레일압력이 가장 큰 영향을 미쳤고 각 부하에서 영향의 크기는 다르게 나타났다.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.59-67
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• 2000

Recently the world is faced with the very serious problems related to the increasing use of the conventional petroleum fuels. THe air pollutions in big cities were also occurred by the exhaust emissions from automobiles. many researchers have been attracted various oxygenated fuels as an alternative fuel and a renewable fuel for the measure of these problems. In this study the effect of oxygen in fuel on the exhaust gas emissions has been investigated with oxygenated fuels as an alternative fuel for diesel engine. The exhaust gas emission were investigated by comparing with that of the diesel fuel. The vegetable fuel oil such as soybean oil gives lower smoke level than that with diesel fuel. Furthermore the smoke emission is more affected by the oxygen content in fuel than by the fuel viscosity. This study concluded that the fuels including oxygen might be a good measure to reduce smoke in diesel engine because the oxygen strongly influenced the combustion process.

• Tribology and Lubricants
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• 제28권6호
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• pp.321-327
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• 2012

Paraffin bio-based hydrotreated biodiesel(HBD) is originated from vegetable oil(the process can also be applied to animal fat) with the the chemical structure $C_nH_{2n+2}$. In the number of process of the oil or fat, the hydrogenation is significantly important to create a bio-based diesel fuel. This study is focused on lubricity characteristics of BTL diesel blends to use alternative diesel fuel in Korea. The BTL diesel are blended the different volume ratios (HBD 5(5 vol.% HBD - 95 vol.% diesel), HBD 10, HBD 20, HBD 30, HBD 40 and HBD 50. HBD with paraffin compounds showed a very high centane number, low sulfur content and free aromatic compound. Especially, the wear scar of HBD showed poor lubricity compared to automotive diesel due to the fuel composition, low sulfur content and free aromatic compound. Also, the lubricity specification of automotive diesel with different six HBD blends is within the limit by the Korean standards. Finally, HBD as an alternative diesel fuel is challengeable in transportation sector of Korea.

• Tribology and Lubricants
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• 제26권4호
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• pp.240-245
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• 2010

This paper describes the influence on engine main bearing behavior of the oil film when the fuel is diluted on a diesel engine equipped with DPF system. Oil film pressure and the thickness is calculated in accordance to the fuel dilution. The calculation is based on the numerical analysis of the engine main bearing. As a result, the engine oil viscosity decreased as the fuel dilution increased. This led the increment of the maximum oil thickness pressure. Verification of the minimum oil film thickness settlement by the engine gas pressure and the fuel dilution was confirmed. Destruction possibility of the engine main bearing was foreseen when the engine speed was 2000 rpm with the fuel dilution 15% and the 5W40 engine oil.

• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.145-155
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• 2020

This study analyzes the degree of competition in the oil refinery market in Korea, which is considered an oligopoly market. The price of gasoline and diesel and the quantity of supply are used to identify the market competition. We also analyze whether the oil tax reduction policy has affected market competition. The competitiveness of the market was examined using monthly data from 2008 to 2019. Bresnahan-Lau method was employed to estimate the degree of competition in the oil refinery market, which is frequently used in the industrial studies. The analysis shows that the gasoline and diesel markets seem close to a perfect competitive market. Also, the tax cut has weakened market competition. In other words, the monopolistic power has increased in the market, so consumers have not benefit from the price cuts as much as tax cuts. Although the oil refinery market where four major companies are competing, the government's monitoring and price disclosure system help the market to be highly competitive as much as a perfect competition market. The tax cut, in the high oil price era, has a negative effect on the competition because of an information asymmetry about the price-setting process between suppliers and consumers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1121-1126
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• 2003

Strength evaluation was carried out for the fillet and oil hole of crankshaft of medium speed diesel HiMSEN engine to verify initial concept design. Alternating torque obtained from torsional vibration analysis and radial force due to firing pressure were applied. It was assumed that the maximum alternating torque and radial force occur simultaneously. Weak points in view of fatigue are proceeding fillet and crank pin fillet area and the minimum normalized fatigue safety factor is 1.17 at crank pin fillet. The fatigue strength of the oil hole was evaluated to verify the effect of the surface roughness of the oil hole. As results, the specific level of the inner surface roughness and the polishing depth of the oil hole for sufficient fatigue strength was suggested. The maximum stress value and stress distribution at the inner surface of the oil hole can be easily estimated at initial design stage by the newly developed method.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.3-43
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• 1998

Technical and business transformations are reshaping the business of Diesel engine builders, Diesel lubricant marketers and additive companies. Key issues facing engine builders and end users under these transformations include: -Emission regulations -Vehicle operating costs -Evolving business environments With these challenges come opportunities. For equipment builders and lubricant marketers, these include: -Lubricants meeting global performance requirements -High value lubricant applications -Profitable new businesses