• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3383-3388
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• 2014

An experimental study was performed to compare the characteristics of the combustion pressure and exhaust emissions in the case of using pure diesel when the EGR rate was changed in a CRDI 4-cylinder diesel engine with those using biodiesel blended and pure diesel fuel. In this study, the EGR rate variation were conducted at an engine speed of 2000rpm with fuel with a biodiesel blended rate of 20%. The combustion pressure of the biodiesel blended rate 20% and pure diesel fuels decreased with increasing EGR rate. The IMEP of biodiesel was higher than that of ULSD (Ultra low sulfur diesel). The emission results showed that the NOx emission of biodiesel blended fuel with increasing EGR rate was higher than that of ULSD. In addition, the NOx emission of biodiesel blended and diesel fuel decreased with increasing EGR rate. The CO and soot, $CO_2$ emissions increased with increasing EGR rate, and the CO and soot emissions from the biodiesel blended fuel were lower than that of ULSD but the $CO_2$ emissions were higher.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.681-687
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• 2014

The objective of this work presented here was focused on analysis of in-cylinder combustion characteristic, engine performance, and nitrogen oxides emission characteristic from marine gas oil for propulsion diesel engine of naval vessels and biodiesel with fuel injection timing in a single cylinder diesel engine. In addition, combustion process was analyzed with a high speed camera of marine gas oil and biodiesel fuel. Retarding the fuel injection timing from $BTDC25^{\circ}CA$ to $BTDC5^{\circ}CA$, in cylinder peak combustion pressure was gradually decreased, however, engine torque showed a tendency to increase. The highest nitrogen oxides level was measured at $BTDC15^{\circ}CA$, they were reduced at retarded and advanced condition on the basis of $BTDC15^{\circ}CA$. Comparing with combustion process of marine gas oil and biodiesel fuel at $BTDC5^{\circ}CA$, self-ignition timing of biodiesel fuel included oxygen content was faster than marine gas oil, however, a cautious observation indicates a slightly higher flame intensity for marin gas oil than biodiesel as a diffusion flame is developing.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.381-386
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• 2015

Environmental pollution and alternative energy has attracted increasing interest. The use of diesel engines is expected to increase in the world owing to their fuel economy. The problem of air pollution emissions from marine engines is causing a major concern in many areas. An alternative fuel was introduced as an environmentally friendly fuel to reduce the toxic emissions from conventional fossil fuels. Biodiesel fuel, which is a renewable energy is highlighted as environmentally friendly energy. This energy can be operated in regular diesel engines when it is blended with invariable ratios without making changes. In this study, a bio-diesel fuel was produced from waste cooking oil and applied to a marine diesel engine to examine the effects on the characteristics of combustion. Waste cooking oil contains a high cetane number and viscosity component, a low carbon and oxygen content. As a result, the brake specific fuel consumption was increased, and the cylinder pressure, rate pressure rise and rate of heat release were decreased.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.83-87
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• 2008

We have a lot of interest in alternative fuels to provide energy independence from oil producing country and to reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel without change of engine structure in diesel engine of compression ignition engine. In this paper, the test results on specific fuel consumption and exhaust emissions of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine. Especially this biodisel was produced from rape oil at our laboratory by ourselves. This study showed that specific fuel consumption and NOx emission were slightly increased, on the other hand CO emission and Soot were tolerably decreased more in the case of biodiesel blends than neat diesel oil.

• Journal of the korean Society of Automotive Engineers
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• v.26 no.3
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• pp.31-34
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• 2004

국내 소비 에너지의 대부분을 해외에 의존하는 실정에서 2004년 현재 배럴당 $35를 넘는 고유가로 인해 원유수입액이 국가 경제에 큰 부담이 되고 있을 뿐만 아니라, 수송용 연료 사용의 지속적인 증가에 따라, 특히, 인구가 밀집한 도심지의 대기오염도는 우려할만한 상황에 이르렀다. 국내 운행 자동차에 의한 석유 소비량은 전체 석유 소비량 중 30% 정도가 수송연료로 쓰이고 있고, 운행차량 중 약30%가 매연, 아황산가스 배출에 대한 기여도가 높은 디젤차량 이어서, 효율면에서 유리한 디젤엔진의 디젤 연료를 대체할 수 있는 초 청정연료에 대한 관심이 높아지고 있다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.579-584
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• 2007

대두유로부터 생산된 바이오디젤과 바이오디젤 혼합 연료유를 대상으로 지방산메틸에스터 함량과 화학적 분석을 통해 산화 특성과 오일의 수명 예측 연구를 수행하였다. 바이오디젤, 경유, BD5, BD20은 산화가 진행될수록 산가(Acid number), 동점도(Kinematic Viscosity) 및 밀도(Density)는 증가하였다. 산가 측정결과의 활용에 의해 임의의 온도조건에서 정확한 사용수명을 예측하기 위하여 화학속도론에 의거하여 각각의 연료에 대한 사용수명식을 도출하였다. 도출된 사용수명식으로부터 바이오디젤이 가장 빠르게 산화가 진행되었고 바이오디젤 혼합량이 증가할수록 사용수명이 단축되는 것을 확인할 수 있었다.

• New & Renewable Energy
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• v.3 no.2 s.10
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• pp.17-23
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• 2007

대두유로부터 생산된 바이오디젤과 바이오디젤 혼합 연료유를 대상으로 지방산메틸에스터 함량과 화학적 분석을 통해 산화 특성과 오일의 수명 예측 연구를 수행하였다. 바이오디젤, 경유, BD5, BD20은 산화가 진행될수록 산가(Acid number), 동점도(Kinematic Viscosity) 및 밀도(Density)는 증가하였다. 산가 측정결과의 활용에 의해 임의의 온도조건에서 정확한 사용수명을 예측하기 위하여 화학속도론에 의거하여 각각의 연료에 대한 사용수명식을 도출하였다. 도출된 사용수명식으로부터 바이오디젤이 가장 빠르게 산화가 진행되었고 바이오디젤 혼합량이 증가할수록 사용수명이 단축되는 것을 확인할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.53-59
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• 2011

The using of diesel engine will be increased in the world for fuel economy. But diesel engine emits harmful emissions such as much NOx, smoke etc. In this study, experiments were performed to investigate the spray characteristics of diesel spray in a common-rail system according to fuel temperature, injection pressure, injection period and fuel viscosity etc. using a high speed video camera. Diesel oil has different spray patten due to injection pressure and injection period in a common-rail system. A Filter pressure was influenced by fuel temperature which was turned to fuel viscosity related to a fluid flowing. The effect of the bio-diesel fuel mixing ratio on the spray and atomization characteristics was also investigated at various experimental conditions. It shows that the droplet atomization characteristics of bio-diesel fuel showed deteriorated results as the mixing ratio of biodiesel increased because of the high viscosity.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.332-337
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• 2013

National investment was performed in the research and development of renewable energy because of climate change by air pollution, exhaustion of energy sources, energy security, and so on. Biodiesel fuel of the renewable energy is highlighted as friendly environment energy, it is possible to operate in regular diesel engines when it is blended with invariable ratios without making any changes. Emission factors have been estimated for commercial ship from various research institutes; however, it is difficult to develop emission factors for military vessels. In this work, biodiesel blended fuel emission factors for sulfur dioxide and carbon dioxide were quantitatively estimated from propulsive diesel engine installed on naval vessel using fuel property analysis. In addition, exhaust emissions were quantitatively calculated on the basis of fuel consumption rate with biodiesel content by percentage.

• Journal of Power System Engineering
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• v.9 no.3
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• pp.21-25
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• 2005

디젤분무가 연소실 벽에 충돌할 때의 연료부착특성을 파악하기 위하여 평판에 충돌하는 디젤 분무의 부착특성을 실험적으로 연구하였다. 투명 아크릴판을 이용하여 연료액막과 충돌분무를 동시에 촬영하였고, 충돌분무의 성장에 따른 연료액막의 성장도 함께 측정되었다. 부착된 연료는 연료액막 및 부착액적들로 나누어서 측정할 수 있었으며 그 결과 연료액막 주변에 무수한 연료액적이 부착함을 알 수 있었다. 시간에 따른 부착연료비를 예측하기 위하여 몇 가지 가정이 사용되었다. 그 결과 시간경과에 따른 부착연료비를 충돌거리 10mm, 30mm, 50mm에 대하여 예측할 수 있었다.