• Proceedings of the KSME Conference
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• 2001.11b
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• pp.800-805
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• 2001

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 which influenced the environment strong. In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for diesel engine. And, we tried to analysis the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine. It have been investigated by the quantitative analysis of the hydrocarbon $C_1\simC_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. The results of this study show that the hydrocarbon $C_1\simC_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed. In particular, high boiling point hydrocarbons such as $C_5$ and $C_6$ were reduced remarkably in high speed and load region.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.178-185
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• 2007

A study is improvement of power and emission in a inline-pump Dr diesel engine by using Dimethyl ether Fuel. Dimethyl ether (DME) is an oxygenated fuel with a cetane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. But NOx emission is almost same and CO, THC emissions are lower than that of diesel engine. The emissions aren't satisfied the stronger emission regulation in the further. Generally DOC (Diesel Oxidation Catalyst) is used to reduce CO & THC emissions and EGR (Exhaust Gas Recirculation) system is used to reduce NOx emission. Test results showed that the torque and the power with DME were almost same as those of pure diesel oil, but the brake thermal efficiency increased a little. also the BSEC (Brake Specific Energy Consumption) with DME was similar that of diesel. The test results showed that the DOC was the vary effective method to reduce the CO emission in case of Dimethyl Ether Fuel in diesel engine. But, THC emission is showed a little reduction rates. Also EGR system was the very effective method to reduce the NOx emission in case of Dimethyl Ether Fuel in diesel engine.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1575-1582
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• 1992

This study describes the response performances of actual engine speed, turbocharger speed, air mass flow rate through engine, boost pressure ratio, exhaust temperature and combustion efficiency for a six-cylinder four-stroke turbocharged diesel engine during the change in operating conditions by using the computer simulation with test bed. In order to obtain the transient conditions, a suddenly large load was applied to the simulation engine with the several kinds of inertia moment in turbocharger and engine, and engine set speed. From the results of this study, the following conclusions were summarized The inferior response performances was mainly caused by turbocharger lag, and air mass flow rate and boost pressure ratio were closely related to the turbocharger speed. A reduced moment of turbocharger inertia resulted in less transient speed drop and much faster recovery to the steady state of the engine. The increase of moment of engine inertia reduced cyclic variation of engine speed. When a large load was applied to the engine at high speed, the engine could be fastly recovered. However, when the same load was applied to the engine at low speed, the engine was stalled.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.997-1002
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• 2012

Emission regulations have been strengthened step by step for marine engines. A noble measure is required both inside and outside of the combustion chamber. The combustion characteristics in cylinder have a very close relationship with the exhaust emission characteristics. Injection valve and nozzle hole geometry is an important factor for combustion. The study to improve the spray characteristics has concentrated on nozzle inlet geometry and nozzle hole diameter, but the exit geometry has not considered. In this study the nozzle exit angle variation was tested. The results show that the angle between $30^{\circ}$ and $60^{\circ}$ is more effective than the other cases.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.43-48
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• 2008

The exhaust emissions of diesel engine are recognized as a major cause influencing environment strongly. In this study, the possibility of biodiesel fuel and oxygenated fuel(dimethoxy methane; DMM) 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 approximately 70% at 2500rpm, full load, in comparison with the diesel fuel. But, power, torque and brake specific energy consumption showed no significant differences. But, NOx emission of biodiesel fuel and DMM blended fuel increased compared with commercial diesel fuel due to the oxygen component in the fuel. It was needed a NOx reduction counterplan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with BDF(95 vol-%) and DMM(5 vol-%) blended fuel and cooled EGR method(15%).

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.35-40
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• 2007

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engine are recognized main cause which influenced environment strong, In this study, the potential possibility of biodiesel fuel was investigated as an alternative fuel for a naturally aspirated common rail diesel engine. The smoke emission of biodiesel fuel 5vol-%(min. content) was reduced in comparison with diesel fuel, that is, it was reduced approximately 60% at 4000rpm, full load. But, power, torque and brake specific energy consumption didn't have no large differences. But, NOx emission of biodiesel fuel was increased compared with a commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with biodiesel fuel(5vol-%) and cooled EGR method($5{\sim}10%$) in a common rail diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.65-71
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• 2005

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engine are recognized main cause which influenced environment strong. In this study, the potential possibility of biodiesel fuel was investigated as an alternative fuel for a naturally aspirated D.I. diesel engine. The smoke emission of biodiesel fuel was reduced remarkably in com parison with diesel fuel, that is, it was reduced approximately 48.5% at 2500rpm, full load. But, power, torque and brake specific energy consumption didn't have no large differences. But, $NO_X$ emission of biodiesel fuel was increased com pared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) on the characteristics of $NO_X$ emission has been investigated. It was found that simultaneous reduction of smoke and $NO_X$ was achieved with biodiesel fuel(20vol-%) and cooled EGR method($5{\sim}15%$).

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.120-127
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• 2005

An IDI diesel engine used to agricultural tractors was fueled with $20\%$ biodiesel fuel(BDF 20) in excess of 300 hours. Engine dynamometer testing was completed at regularly scheduled intervals to monitor the engine performance and exhaust emissions. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. The combustion variation such as the combustion maximum pressure and the crank angle at this maximum pressure was not appeared during long-time dynamometer testing. Also, BSFC with BDF 20 resulted in lower than with diesel fuel. Since the biodiesel fuel used in this study includes oxygen of about $11\%$, it could influence the combustion process strongly. So, BDF 20 resulted in lower emissions of carbon monoxide, carbon dioxide, and smoke emissions without special increase of oxides of nitrogen than diesel fuel. It was concluded that there was no unusual deterioration of the engine, or any unusual change in exhaust emissions from using the BDF 20.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.32-38
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• 2004

To evaluate the durability of direct injection diesel engine using biodiesel fuel, a small D. I. diesel engine was operated on a blend(BDF 20) of 20％ biodiesel fuel and 80％ diesel fuel for 200 hours. Engine dynamometer test was performed at a load of 90％ and a speed of 1900 rpm to monitor the engine performance and exhaust emissions. Engine performance parameters and exhaust emissions were sampled at 1 hour interval for analysis. The combustion maximum pressure and the crank angle at this maximum pressure as a combustion variation factor were considered to study the combustion characteristics of BDF 20 in diesel engine during durability test. As the results, the standard deviations and errors of combustion variation factors on BDF 20 were very little and combustion characteristics were very stable during the durability test. BDF 20 resulted in lower emissions of carbon monoxide, carbon dioxide, and smoke emissions with special increase of nitrogen oxides compared to diesel fuel. There was no also unusual change in engine oil composition from using BDF 20. Most of engine parts were clean and showed little wear, but soots were detected around the hole of fuel injector when BDF 20 was used in direct injection diesel engine for 200 hours.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.870-875
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• 2015

Diesel engines are widely used due to superior power and fuel consumption, however there are many challenges in exhaust gas management. Exhaust gas recirculation (EGR) is the most effective technique for reducing mono-nitrogen oxide (NOx) emissions in a diesel engine, in comparison with other catalytic technologies. In addition, the technology has a number of advantages in terms of economic efficiency and implementation. In this study, the effects on the power and exhaust characteristics of diesel engines equipped with EGR systems were investigated. It was found that as the EGR rate increased, horsepower expressed as IHP and BHP decreased. The net effect of the application of EGR was measured at various engine speeds. EGR technology caused decreases in BHP of around 9% during low engine speed and 3.5% during high engine speed. Additionally, NOx emissions reduced as the EGR rate increased, and increased as engine speed increased. However, smoke emissions increased as the EGR rate increased, and decreased as engine speed increased. The optimum operating conditions and ERG rate to simultaneously achieve minimum NOx and smoke emissions were investigate. It was found that as the EGR rate increased, optimal operating speed for minimal NOx and smoke also increased. Keywords: Diesel engine, Exhaust gas recirculation, Power perfomance, Emission characteristics, NOx, Smoke