• 동력기계공학회지
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• 제9권3호
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• pp.15-20
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• 2005

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for an indirect injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel(10vol-%) and cooled EGR method(10%).

• 에너지공학
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• 제18권3호
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• pp.169-174
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• 2009

본 연구에서는 수송용 경유를 연료로 사용하고 있는 간접분사식 디젤기관에 있어서 연료에 초음파 에너지를 조사하였을 때의 기관성능 및 배출물질 특성 변화에 대해 조사하였다. 실험은 경유에 초음파 에너지를 조사한 연료와 상용 경유를 간접분사식 디젤기관에 적용하여 다음과 같은 결론을 얻었다. 본 운전조건하에서, 초음파 에너지를 조사한 경유로 디젤기관을 운전하였을 경우,상용 경유 운전 시에 비해 지압선도, 열발생율 및 출력이 상승하고 질량연소율이 단축되었으며 제동연료소비율과 매연은 감소하였다. 또한, 보다 안정화되면서 완전한 연소가 이루어졌으며 질소산화물은 증가하였다.

• International Journal of Advanced Culture Technology
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• 제4권1호
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• pp.10-18
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• 2016

In the present study, a single cylinder four stroke dual fuel diesel engine was tested to investigate the performance and emission characteristics of various test fuels. The engine was tested in dual fuel mode using diesel and Karanja biodiesel blends as pilot fuel along with Natural gas as primary fuel with a constant gas flow rate under different loading conditions. From the experimentation it was found that smoke opacity and oxides of nitrogen (NOx) are at low level for all the prepared test fuels in dual fuel mode but the emissions of carbon monoxide (CO), carbon dioxide ($CO_2$) and hydrocarbon (HC) were found higher. In comparison to diesel fuel, by increasing the blend percentage different emission parameters are found to be reduced. At different loading conditions all the test fuels show poor performance in dual fuel mode of operation when compared with single mode of operation with diesel and biodiesel. With increase in gas flow rates, except (NOx) and smoke emissions, the other emission parameters like CO, HC and $CO_2$ values increased for all test fuels. Again, all blended fuels showed lower performance compared to diesel. The maximum pilot fuel savings for diesel was found decreasing with the increase in karanja biodiesel. From the present work it may be concluded that Karanja biodiesel with Natural gas in dual mode can be can used as promising alternative for diesel with some required engine modifications and further research must be carried out to minimize the emissions of CO, HC and $CO_2$.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.84-91
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• 2008

Due to increasing need for better emission characteristics and lower fuel consumption rate in automotive engines, alternative fuels are drawing more attentions recently. The GTL (gas to liquid) is the one of most favored candidates. In this study, emission characteristics are compared between diesel and GTL fuel in commercial 2.0 liter diesel engine and vehicle with CRDi(Common Rail Direct injection) system. The effects of injection timings on emission and fuel consumption rate are compared at various engine speeds and loads. Noticeable reduction in HC, CO and PM emissions are observed due to higher cetane number and low sulfur and aromatic contents in GTL. On the trade-off curve of NOx and PM(Particulate matter) GTL showed much more benefits than diesel, where about 30% of PM mass decreased at the same operating conditions. On CVS 75 mode test in vehicle, GTL showed an excellent emission enhancement, in which 50% of HC, 21% of PM, and 12% of NOx engine-out emissions are decreased compared to ULSD(Ultra low sulfur diesel) fuel.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.30-37
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• 2004

The combustion and emission characteristics of a direct injection CI engine fuelled with DME(Dimethyl Ether) and diesel fuel were compared at idle engine speed(800 rpm) with various injection parameters. An optical single cylinder diesel engine equipped with a common-rail fuel injection system was constructed to investigate combustion processes of DME and diesel fuel. The combustion images were recorded with a high-speed video camera system. The results demonstrated that the DME-fuelled engine was superior to the conventional diesel engine in terms of engine performance and emissions. The optimal injection timing of DME was located around IDC(Top Dead Center), which was roughly same as that of diesel fuel. As the injection timing was advanced much earlier than TDC, NOx (Nitric Oxides) level increased considerably. NOx emission of DME was equal or a little higher than that for diesel fuel at the same injection pressure and timing because of higher evaporation characteristics of DME. Throughout all experimental conditions, DME did not produce any measurable smoke level.

• 한국자동차공학회논문집
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• 제18권6호
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• pp.91-97
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• 2010

This paper described the effects of DME blended fuel on the engine combustion and emission characteristics of four cylinder CRDI diesel engine. Biodiesel was added into the DME fuel in order to improve the low kinematic viscosity of DME fuel. In this work, the experiment was performed under th various injection timings and injection strategy at constant engine speed and engine load. To maintain the fuel pressure and temperature, pressure and temperature controllers were installed to the DME fuel system. The results show that ignition delay was shortened and combustion duration was extended when DME blended fuel is supplied. Despite of slightly higher NOx emission with DME blended fuel at equal conditions in comparison with those of diesel fuel, the engine showed lower HC and CO emission characteristics.

• Journal of Biosystems Engineering
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• 제31권6호
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• pp.457-462
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• 2006

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions from diesel engine are recognized main cause which influenced environment strong. In this study, the potential possibility of biodiesel fuel and oxygenates additives (dimethoxy methane) was investigated as an alternative fuel for a naturally aspirated direct injection diesel engine. The smoke emission of blending fuel (biodiesel fuel 90vol-% + DMM 10vol-%) was reduced in comparison with diesel fuel, that is, it was reduced approximately 70% at 2500 rpm, full load. But, power, torque and brake specific energy consumption didn't have no large differences. But, NOx emissions from biodiesel fuel and DMM blended fuel were increased compared with commercial diesel fuel.

• 동력기계공학회지
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• 제18권6호
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• pp.106-112
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• 2014

The diesel engine, which has high compression ratio than other heat engines, has been using as the main power source of marine transport. Especially, since marine diesel engines offer better specific fuel consumption (SFC), it is environment-friendly compared to those used in other industries. However, attentio should be focused on emissions such as nitrous oxide ($N_2O$) which is generated from combustion of low-grade fuels. Because $N_2O$ in the atmosphere is very stable, the global warming potential (GWP) of $N_2O$ is 310 times as large as that of $CO_2$, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. It has been hitherto noted on the $N_2O$ exhaust characteristics from stationary power plants and land transportations, but reports on $N_2O$ emission from the marine diesel engine are very limited. In this experimental study, a author investigated $N_2O$ emission characteristics by using changed diesel fuel components of nitrogen and sulfur concentration, assessed on the factors which affect $N_2O$ generation in combustion. The experimental results showed that $N_2O$ emission exhibited increasement with increasing of sulfur concentration in fuel. However, all kinds of nitrogen component additives used in experiment could not change $N_2O$ emission.

• 한국분무공학회지
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• 제6권2호
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• pp.22-28
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• 2001

Recently, many researches have been performed to improve the combustion and emission in a D.I.Diesel engine. Especially reduction of the soot formation in the combustion chamber is the essential to acquire the improvement of the emission performance. This emission of the diesel combustion is effected by the characteristics of air-fuel mixing. Therefore, the optical measurement technique such as LII and LIS were established in order to visualize the distribution of the soot and analyze the particle including spray in the combustion chamber. In this study, we developed the algorithm for calculating relative diameter and density of particle and applied this method to measure stimultaneously the distribution of soot and spray in a D.I. diesel engine. From this experiment we found that the soot is existed in the rich region of spray and generated caused by incapable air fuel mixture.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.62-67
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• 2009

In this study, the potential possibility of biodiesel fuel was investigated as an alternative fuel for a naturally aspirated indirect injection diesel engine. The smoke emission of biodiesel fuel was reduced remarkably in comparison with diesel fuel, that is, it was reduced approximately 36% at 2000rpm, full load condition. And, power, torque and brake specific energy consumption showed no significant differences. However, NOx emission of biodiesel fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) to reduce the NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel(20vol-%) and cooled EGR method$(10{\sim}15%)$.