• 한국자동차공학회논문집
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• 제8권2호
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• pp.1-8
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• 2000

Recently, Our planet is faced with very serious 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 of diesel engine that influenced the environment strong. But most researchers have mainly studied and suggested the solution of reduction on the total exhaust emissions of diesel engine. In this study, the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine have been investigated by the quantitative analysis of the hydrocarbon C1~C6 using the gas chromatography. This study carried out by comparing the chromatograms with diesel fuel and mixed fuel which are blended the diesel and DMC(dimethyl carbonate)that includes the oxygen of about 53%. The results of this study show that the hydrocarbon C1~C6 among the exhaust emissions of the mixed fuel are exhausted lower than those of the diesel fuel at the all load.

• 한국분무공학회지
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• 제2권2호
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• pp.43-50
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• 1997

The purpose of this investigation is to carry out, the influence factor on the fuel spray characteristics for improve the engine combustion performance and exhaust omission in direct injection type diesel engine. The fuel properties, fuel spray structure and the shape or the piston surface of diesel engine play an important role of engine combustion process and exhaust emission. In order to obtain the effect of using auxiliary chamber and emulsified fuel on the fuel spray characteristics the experiment un conduct with single cylinder direct injection type diesel engine to examine the engine performance and gas emission. The results of this investigation showed that the increase auxiliary chamber volume and emulsified fuel give an effect on the fuel spray characteristics by reduced the concentration of nitric oxide emission in the combustion chamber. Also it can improve the combustion characteristics such as cylinder pressure, rate of pressure rise and rate of heat release.

• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.533-540
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• 2014

The remanufacturing industry for automotive parts is a major issue which affects the environment protection and CO2 reduction throughout the world. Beside this, remanufacturing technologies of worn-out diesel engines have been developing to make as close to new as possible. In this study, the characteristics of the engine-power output and exhaust emissions of remanufactured diesel engine by hydrogen enrichment are evaluated by measuring the engine and vehicle test. Moreover, with worn-out diesel engine and first generation common-rail engine, we compared by testing their characteristics, resulting in the restoration of engine-power output more than 93%, as well as marvelously reduces the THC and NOx emission. At a guess, high pressure injection of diesel increases fuel atomization characteristics with excellence combustion efficiency, resulting in reduction of THC emission. Also, rapid cooling of EGR decreases combustion temperature, resulting in reduction of NOx emission. Consequently, these remanufacturing for diesel engine enables worn-out diesel engine to have restoration to the original state. Simultaneously achieved 2 goals called that CO2 emission reduction and protection of environment by remanufacturing engine.

• 한국환경과학회지
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• 제21권7호
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• pp.769-778
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• 2012

Diesel DeNOx experiments using the SNCR process were performed by directly injecting NH3 into a simulated engine cylinder (966 $cm^3$) for which a diesel fuelled combustion-driven flow reactor was designed by simulating diesel engine geometry, temperature profiles, aerodynamics and combustion products. A wide range of air/fuel mixtures (A/F=20~45) were combusted for oxidizing diesel flue gas conditions where an initial NOx levels were 250~900 ppm and molar ratios (${\beta}=NH_3/NOx$) ranged from 0.5~2.0 for NOx reduction tests. Effective NOx reduction occurred over a temperature range of 1100~1350 K at cylinder injections where about 34% NOx reduction was achieved with ${\beta}$=1.5 and cylinder cooling at optimum flow conditions. The effects of simulated engine cylinder and exhaust parts, initial NOx levels, molar ratios and engine speeds on NOx reduction potential are discussed following temperature gradients and diesel engine environments. A staged injection by $NH_3$ and diesel fuel additive is tested for further NOx reduction, and more discussed for practical implication.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.160-170
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• 1997

The objective of this study is to investigate the atomization characteristics and the performance characteristics of a C. I. engine by using the changes of the injection nozzle type and the ultrasonic-energy-added system. In order to evaluate the effect of ultrasonic energy and of change of injection nozzle type in the performance characte- ristics of a diesel engine, measurements of droplet size of diesel fuel were carried out by using Malvern system. In all types of injection nozzles, SMD of the ultrasonic- energy -added diesel fuel was smaller than that of the conventional diesel fuel and the more injection pressure increased, the more SMD decreased. There was a small increase in SMD with the distance from injection nozzle under all conditions of the injection nozzle types. The minimum SMD was found in the injection nozzle of B type. In the diesel engine test, there were three results about the engine performance. Compared with the injection nozzle of A type, B type had excellent effects in the engine performance. The most excellent effects about the engine performance were obtained in the case of ultrasonic-energy-added diesel fuel. In addition, the torque diagram in the case of ultrasonic-energy-added diesel fuel was more stable and periodical than others.

• 한국자동차공학회논문집
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• 제9권4호
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• pp.69-76
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• 2001

VCO nozzle is devised to minimize the HC emission and has been applied on some HSDI diesel engines. But it is not well reported whether VCO nozzle would be advantageous over SAC nozzle in a small HSDI diesel engine. In this paper it is presented that characteristics of VCO and SAC nozzle under common rail fuel injection system and their effects on the performance in a small HSDI diesel engine.

• 한국자동차공학회논문집
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• 제22권5호
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• pp.59-65
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• 2014

Diesel engines have the superior combustion efficiency and fuel economy that they are widely used for industry, heavyduty vehicles, etc. However, its exhaust emissions have become the major concerns due to their environmental impacts. Moreover, the depletion of fossil fuels is the main issue. Therefore, it is important to look for alternative sources of energy. Bio-diesel is one of the ideal energy which has proved to be ecofriendly for more than fossil fuels. The experimental tests analysed the engine performance and emission characteristics of a diesel engine using diesel and biodiesel blended of BD25, BD45 and BD65, in order to study the use of clean fuel to meet the increasingly stringent emission regulations. The engine performance was examined by using engine dynamometer while an exhaust gas analyzer was used to examine the emission characteristics. The effect of biodiesel on engine performance were lower to diesel through comparing their HP and torque but fuel consumption was slightly increased because of biodiesel has lower heating value and higher density than diesel. However, due to the better lubricity, the brake thermal efficiency of biodiesel was higher than diesel. The emission characteristics were strongly affected by the blending ratio of diesel and biodiesel. The results showed that the smoke opacity, hydrocarbons (HC) and carbon monoxide (CO) emissions decreased while the nitrogen oxides (NOX) slightly increased.

• 한국자동차공학회논문집
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• 제15권4호
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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.

• 한국자동차공학회논문집
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• 제23권3호
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• pp.263-270
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• 2015

Using Diesel-Water Emulsion fuel in commercial diesel engine can reduce NOx and soot when it is injected through the injector. Because water in Diesel-Water Emulsion fuel is vaporized ahead of diesel particle and it cause decrease of combustion temperature. Furthermore, research about the possibility of applicating Diesel-Water Emulsion fuels to commercial diesel engine is demanded in order to prove that Diesel-Water Emulsion fuel is able to apply commercial diesel engine without any replacement of equipments. This research analyzed applicable possibility of Diesel-Water Emulsion fuels to commercial diesel engine's fuel injection system refering injection and spray characteristics. In this research, there are 3 experiments, that is injection quantity, spray visualization, and injection rate. Diesel-Water Emulsion fuel has less injection quantities compared to diesel fuel, and spray penetration length is more longer than diesel. Furthermore, emulsion fuels have less dispersed than diesel fuel. In conclusion, comparing with diesel fuel with only spray characteristics, Diesel-Water Emulsion fuel has bad effects about dispersion and vaporization.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.74-80
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• 2007

An experiment was conducted with a common-rail direct injection diesel engine operated with neat dimethyl ether (DME). In order to investigate the effect of combustion characteristics and emission reduction of DME fuel, the experiment was performed at various injection pressure from 35 MPa to 50MPa. Also, the exhaust emissions from the engine were compared with that of diesel fuel. In this work, Cooled EGR was implemented to reduce $NO_x$ exhaust emissions. The results showed that DME has shorter ignition delay than that of diesel fuel. Despite of the increased $NO_x$ emissions with DME at an equal engine power compared to the case of fueling diesel, the engine emitted zero soot emissions all over the operating conditions in this work. $NO_x$ emission can be decreased greatly by adopting 45% of EGR while maintaining zero soot emission. Judging from the result of engine test, DME is a suitable fuel for common-rail diesel engine due to it's clean emission characteristics.