• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.97-104
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• 2015

This study is a part of the high pressure injection system development on the Turbo GDI engine in order to reduce smoke emission in case of using the low volatile(high DI) fuel which is used as normal gasoline fuel in the US market. Firstly, theoretical approach was done regarding gasoline fuel property, performance, definition of particle matters and its creation as well as problems of the high DI fuel. In this experimental study, 2L Turbo GDI engine was selected and optimized system parameter was inspected by changing fuel, fuel injection mode (single/multiple), fuel pressure, distance between injector tip and combustion chamber, start of injection, intake valve timing in engine dyno at all engine speed range with full load. In case of normal gasoline fuel, opacity was contained within 2% in all conditions. On the other hands, in case of low volatile fuel (high DI fuel), it was confirmed that the opacity was rapidly increased above 5,000 rpm at 14.5 ~ 20 MPa of fuel pressure and there were almost no differences on the opacity(smoke) between 17 MPa and 20 MPa fuel pressure. According to the SOI retard, smoke decrease tendency was observed but intake valve close timing change has almost no impact on the smoke level in this area. Consequently, smoke decrease was observed and 16% at 6000rpm respectively with injector washer ring installed. By removing injector washer to make injector tip closer to the combustion chamber, smoke decrease was observed by 46% at 5,500 rpm, 42% at 6,000 rpm. It is assumed that the fuel injection interaction with cylinder head, piston head, intake and exhaust valve is reduced so that impingement is reduced in local area.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.5
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• pp.81-88
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• 1991

Combustion characteristic, concentration of NOx and exhaust smoke opacity was experimentally tested, according to fuel injection timing, mixing ratio of water and methanol for the driving condition of 2000 rpm of engine revolution and constant load(7.5kg/cm$^{2}$) using emulsified fuel of gas oil-water methanol. The result obtained was as following. Thermal efficiency indicated highly 0.4-2.7% for emulsified fuel then gas oil, and injection timing when maximum thermal efficiency, slicily risen then gas oil. For constant fuel injection timing ignition lag was increased, combustion duration decreased, maximum heat release rate indicated high, and concentration of NOx and exhaust smoke opacity is decreased, as function of water and methanol content y was higher.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.769-772
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• 2010

The objective of the current research work is to investigate the usage of biodiesel combined with the use of EGR in order to reduce the emission of all regulated pollutants from diesel engines. A single cylinder, air cooled, constant speed direct injection diesel engine was used for the experimental work and a cold EGR system was developed and fitted to the engine. Concentrations of HCs, NOx, and CO from the exhaust gas along with the smoke opacity were measured. Engine performance parameters such as the brake thermal efficiency (BTE) and the brake specific energy consumption (BSEC) were also calculated from the measured data. The results from the present investigation suggest that 25-30% EGR rate could give excellent NOx reduction without any significance penalty on smoke opacity or BSEC under the engine load of up to 40%. Under the full load condition, 15% EGR rate was found to be an option while higher EGR rate resulted in inferior performance and heavy smoke.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.701-710
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• 2013

The purpose of this study is to investigate experimentally the effect of low purity methanol (LPM) on performance and smoke emission characteristics by using a four-cycle, four-cylinder, water-cooled, direct injection diesel engine with EGR system. The experiments are performed by the change of engine load in the engine load ranges of 25 to 100% with an interval of 25% under the constant engine speed of 2000 rpm. The LPM in the fuel blends contained 24.88% water by volume. The blended fuel ratios of diesel oil to LPM are maintained at 100/0, 95/5, 90/10 and 85/15% on the volume basis. In this paper, EGR rates are varied in three conditions of 0, 12.8 and 16.5%. The result shows that the brake power of a blended fuel with 15% LPM is reduced more 11.1% than that of the neat diesel oil at the full load with the EGR rate of 16.5%. At this condition, also, the brake specific fuel consumption (BSFC) is increased by 3.2%, the exhaust gas temperature is decreased by 10.7%, the smoke opacity is decreased by 18.7% and the brake thermal efficiency is increased by 7.3%. The sharp reduction of smoke opacity for a blended fuel with the LPM content of 15% at the full load without EGR system is observed by 68.4% compared with that of the neat diesel oil due to the high oxygen content of LPM.

• Journal of Hydrogen and New Energy
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• v.34 no.1
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• pp.69-76
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• 2023

An experimental study was conducted on a 4-stroke direct injection diesel engine to examine the combustion and emission characteristics of 1-octanol/diesel fuel blends. The concentration of 1-octanol in the fuel blends was 10%, 30%, and 50% by volume. Experiments were conducted by varying the engine torque from 6 Nm to 12 Nm at the same engine speed of 2,700 rpm. Results showed that the fuel conversion efficiency increased as the 1-octanol proportion increased under most experimental conditions. However, the brake specific fuel consumption increased due to the relatively low lower heating value of 1-octanol. The smoke opacity and the concentrations of NO_x and CO emissions generally decreased with brake mean effective pressure as the 1-octanol proportion increased. On the other hand, the unburned hydrocarbon concentration increased with an ascending ratio of 1-octanol.

• Journal of Hydrogen and New Energy
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• v.35 no.1
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• pp.97-104
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• 2024

In this study, combustion experiments were conducted to assess engine performance and exhaust gas characteristics using four blends of 1-pentanol and diesel as fuel in a naturally aspirated 4-stroke diesel engine. The blending ratios of 1-pentanol were 5, 10, 15, and 20% by volume. The experiments were carried out under four different engine torque conditions (6, 8, 10, and 12 Nm) while maintaining a constant engine speed of 2,000 rpm for all fuel types. The results showed that the use of 1-pentanol/diesel blended fuel generally led to a decrease in brake thermal efficiency, attributed to the low calorific value of the blend and the cooling effect due to the latent heat of vaporization. Additionally, both brake specific energy consumption and brake specific fuel consumption increased. However, the use of the blended fuel resulted in a general decrease in NOx concentration, a decrease in CO concentration except some conditions, and a reduction in smoke opacity across all conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.5
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• pp.146-152
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• 2007

Recently, The air pollution problems become hot issues as the production of the diesel automotive increases. The ministry of environment has enforced a precise inspection law to decrease the vehicle emission. In this circumstances, the smoke measurement is somewhat complicated by the use of the different type smoke meters. Although the paper filtration type opacimeter has been used for measuring smoke widely but currently the light extinction type is being used for precise inspection law. These two type opacimeters are different in their measuring principles on each other. So, for the time being the regulation standards can be confused by these two type opacimeters. In this article, The correlation factor between these two type opacimeters is studied by using engine dynamometer and vehicle test. The result of the dynamometer test shows the light extinction type is more sensitive than the filtration type by 1.47 times. But the relation factor by the vehicle test achieved 1.37 value, which is lower than that of the dynamometer test. In the future study the more precise research is needed to estimate the relation factor on vehicle test.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.273-273
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• 2000

우리나라 대기환경기준은 이미 선진국 수준으로 강화되었거나 강화될 계획으로 있어 이에 따른 대기오염 방지시설의 설치 또는 보완이 요구되고 있다. 특히, 배기가스 중 황산화물 배출농도 강화로 황산화물 저감을 위한 배연탈황설비 설치ㆍ가동중에 있으나 황산 Mist가 주요원인으로 추정되는 Plume Opacity가 발생되어 대기 중에서 색깔을 띄게됨에 따라 오염물질 배출농도는 법적 규제기준 이내로 배출되더라도 인간의 심리적 불안감을 유발할 수 있어, 그 발생원인을 규명함과 동시에 현장여건에 적합한 최적의 황산 Mist 저감방법을 연구하고자 하였다. (중략)

• Journal of Energy Engineering
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• v.22 no.2
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• pp.136-140
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• 2013

The stringent emission norms cannot be met through engine design and exhaust after treatment alone. Use of oxygenated fuel like biodiesel as a alternative to diesel may be the best way to reduce emissions today. In this study, Diesel fuel and pure biodiesel (mahua oil) were tested on a single cylinder naturally-aspirated direct-injection diesel engine. The study aims to investigate the effects of the mahua oil biodiesel on existing diesel engine emissions. The effect of test fuels on engine emissions like CO, HC, $CO_2$, NOx and smoke emissions was investigated with respect to the load on engine. Smoke opacity of Diesel engine was lower in case of biodiesel of mahua oil as compare to mineral diesel. NOx emissions was little higher during the whole range of loading, which is a typical characteristic of biodiesel. However the increments are within in the narrow range. $CO_2$ emissions was bit higher which is the indication of better combustion due to presence of rich oxygen in the mixture, it results in the low values of CO and HC during the whole range of experiments. Thus considering environmental norms most of the engine emissions, it can be concluded and biodiesel derived from mahua oil could be used in a conventional diesel engine without any modification.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.138-142
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• 1998

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects of low sulfur diesel fuel in heavy duty diesel engine equipped with DOC. We tested to estimate change of engine performance for the low and high sulfur diesel fuels in a 11,000cc diesel engine equipped with DOC. We conducted test to estimate the reduction efficiency of exhaust gas in D-13 mode of heavy duty diesel regulation mode and in smoke opacity mode for two samples of high sulfur content (0.2%) and low sulfur content(0.05%)