• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.2
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• pp.85-91
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• 1998

This paper describes an study electric injection system for diesel engines. It is needed effective fuel injection which controls the solenoid valve of fuel pump. To solve this, this paper proposes DCC-PWM method which can realize fast reply and low holding current for solenoid valve on/off. For the proposed design method, simulation tools of ACSL are used to analyze the system. And the single-chip microcomputer is used to reduce the size of controller and to improve flexibility. And the systems validity can be verified through the experimental results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.745-752
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• 2012

Diesel engines are most suitable for biodiesel fuel because diesel fuel has a higher cetane number compared to gasoline and diesel engines have no spark ignition system; hence, engine conversion is easy and cost effective. For these reasons, in this study, the spray behavior characteristics of vegetable palm oil were analyzed by using a common-rail injection system of a commercial diesel engine, and the results were compared with those obtained for the diesel fuel. The injection pressures and blend ratios of palm oil and diesel fuel (BD3, BD5, BD20, BD30, BD50, and BD100) were the main parameters. The experiments were conducted for different injection pressures-500 bar, 1000 bar, 1500 bar, and 1600 bar-by setting the injection duration at $500{\mu}s$. We determined there is no significant difference in the macro characteristics of the spray behavior (spray penetration and spray angle) in response to any change in the blend ratio of palm oil and diesel fuel at a fixed injection pressure. In particular, all experiments showed a spray angle of approximately $15^{\circ}$.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.39-44
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• 2002

배기가스의 규제가 전 세계적으로 강화되고 있는 가운데, 경유사용 디젤기관은 가솔린기관 보다 열효율이 높고 온실가스인 $CO_2$ 배출량이 적은 장점이 있으나, PM(입자상 물질)과 NO$_{x}$가 다량 배출되는 단점이 있다. 이들의 저감책으로서, 엔진개량, 연료분사장치의 고압화와 전자제어화, 배기 후처리기술의 적용 등 디젤기관의 고효율성을 손상시키지 않으면서, 배기공해를 대폭 저감하려는 연구가 활발히 추진되고 있으며, 한편으로는 디젤기관의 대체연료에 대한 연구가 활발히 추진되고 있다.(중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.26-31
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• 2011

In this study, it made to run conventional single direct injection(DI) diesel engine, which adapted bulk combustion system not following spark ignition system without any ignition apparatus. It was heated and controlled inlet-air into conventional single DI diesel engine. The maximum value of brake thermal efficiency was at 35 region of air-fuel ratio. On the contrary, when the region of air-fuel ratio leaner than 35, brake thermal efficiency was decreased suddenly. And brake thermal efficiency was increased as much as inlet-air heating temperature increased. So, when air-fuel ratio was decreased and inlet-air heating temperature was higher, the engine was in optimal operation condition.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.86-95
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• 1996

This study was on the pollution emissions of the Ultrasonic fuel feeding system in gasoline injection vehicle. This work measured th SMD of the fuel, and compared the characteristics through chassis dynamometer and highway road test by the conventional vehicle. And this work measured vacuum degree, turbulence intensity and the rate of fuel consumption according to intake air velocity with swirler. The results are as followed; The effects of the vehicle installed the ultrasonic fuel feeding system are better than those of the conventional vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.50-56
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• 1994

This is an experimental study on the performance characteristics of Diesel Automobile with ultrasonic fuel feeding system. For this purpose, ultrasonic fuel feeding system was made and atomization characteristics was measured. Base on this result, carried out engine dynamometer test to investigate the performance characteristics of diesel automobile with ultrasonic fuel feeding system in comparison with conventional diesel fuel injector. The results are as follows. 1) In the spray characteristics test, fuel particle sizes were decreased about 11%~21%. 2) In engine dynamometer test, -The power was increased about 5%~11%. -The thermal efficiency was improved about 6%~11%. -The specific fuel consumption was improved about 6%~19%. -The smoke concentration was decreased about 11%~50%.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.1-7
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• 2002

Recently, many researches for the improvement of DI diesel engines have been performed to reduce the fuel consumption and exhaust emissions. Among the various factors effect on combustion and emission in Dl diesel engines, one of the most important factors is the characteristics of the fuel spray. Accordingly, the investigation on the characteristics of spray is needed to analyze the diesel combustion exactly, In this study, the measurement technique fur injection rate using the Zeuch method was developed. In addition, the effects of nozzle hole number on the spray and flame were investigated by visualization experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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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.

• Journal of ILASS-Korea
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• v.1 no.2
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• pp.33-41
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• 1996

Mixture formation is one of the important factors to improve combustion performance of MPI gasoline engines. This is affected by spray and atomization characteristics of injector. Especially, in the case of EGI system, air-fuel mixing period is too short and formed a lot of fuel-film in the intake manifold and cylinder wall. This fuel-film is not burnt in cylinder, it is exhausted in the form of HC emission. In this paper, spray characteristics such as size distributions, SMD, and spray angle are measured by PMAS, and the fuel-film measuring device is developed specially. Using this device, the amount and distribution of fuel-film which flows into through valve can be measured Quantitatively. As the result of these experiments, the information of optimal spray characteristics and injection condition that minimize the fuel-film can be built up.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1244-1249
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• 2001

The characteristics of engine performance with fuel injection system in D.I. diesel engine were studied in this paper A fuel injection system has an important role in the performance and emission gas in a diesel engine. In this paper, an experimental study has been performed to verify the effect of the performance and the emission gas with the factors such as diameters of an injection nozz1e hole, diameters of an injection pipe and injection timing in the fuel injection system. The authors have obtained the results that optimizing the factors of fuel injection system is siginificant to enhance the performance of the engine system and consumption ratio of fuel, smoke, and NOx.