• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.283-284
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• 2014

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.187-192
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• 2001

A homogeneous premixed charge compression ignition engine is experimentally investigated for the reduction of exhaust emissions in diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC and CO emissions were increased with the increase of premixed ratio. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.9-14
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• 2002

A homogeneous premixed charge compression ignition engine has been experimentally studied far the reduction exhaust emissions of diesel engines. In this study, the gasoline fuel is injected into the intake manifold to from homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.4
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• pp.241-248
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• 2008

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduction way of NOx and PM. The diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured, so we estimated it by CHEMKIN calculation. Two dimensional spontaneous luminescence images which are created by chemical species reaction at low temperature reaction (LTR) and high temperature reaction (HTR) are captured by using a framing streak camera. Also, combustion events were observed by high-speed direct photography. The ignition and combustion events were analyzed by pressure profiles and the KL values and flame temperatures were analyzed by the two-color method.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.17-23
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• 2002

In order to reduce exhaust emissions from diesel engine under wide operating range, an experimental study based on a new concept of combustion called HCDC(Homogeneous Charge Diesel Combustion) was conducted. In this concept, most of the fuel is supplied as premixed homogeneous charge and the rest is directly injected into a cylinder to ignite. In this study we compared combustion characteristics of an HCDC engine with those of conventional diesel engines. At high premixed fuel ratio and high load range, it was observed that premixed combustion heat release rate was low and diffusion combustion duration was shorten. from this experiment, it was found that NOx is reduced by the lower maximum temperature and soot is reduced by rapid combustion during diffusion combustion phase.

• Journal of Power System Engineering
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• v.13 no.2
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• pp.5-10
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• 2009

In recently, studies concerned to the diesel engine uses a natural gas as a fuel oil whose infra has been built already was approached to PCCI or HCCI with keeping a high thermal efficiency and reducing NOx and PM have been researching actively in normally single cylinder. An ignition source is required to bum the natural gas by a spark plug in gasoline engines, due to a higher auto-ignition temperature of natural gas. Then gas oil and DME were introduced as the ignition source. In this study as basic data for practical use of natural gas PCCI and HCCI engines, combustion characteristics and emission characteristics on 4-cylinders natural gas PCCI and HCCI engines with gas oil and DME as ignition sources were analyzed and the engine load range that is main object for practical use of PCCI and HCCI engines was made clearly by empirical experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.66-72
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• 2002

A premixed charge compression ignition engine is experimentally investigated for the reduction of NOx and smoke emissions from diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentrations of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC emission was increased with the increase of premixed ratio. Also, when EGR system was applied to the PCCI diesel engine, the effect of EGR rate on the combustion characteristics and the exhaust gas emissions was discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.10-16
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• 2004

The Homogeneous Charge Compression Ignition (HCCI) engine has advantage for reducing the NOx and P.M. simultaneously. Therefore, HCCI engine is receiving attention as a low emission diesel engine concept. This study was carried out to investigate the characteristics of combustion and exhaust emission for operating conditions in a direct injection type of HCCI engines such as supercharged and naturally aspirated using diesel fuel and additive. From the experimental result, we found that cool flame was always appeared and also it was difficult to control combustion characteristics by changing the injection timing in HCCI. In addition, at the lean air-fuel ratio and high speed range, it was observed that charging air pressure, additive or increasing intake air temperature is effective to increase combustion performance and reduce exhaust emission. We concluded that chemical reaction by the increasing intake air temperature or additive without physical improvement has limitation for reduction of exhaust emission.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.58-64
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• 2002

A diesel engine has various merits such as high thermal-efficiency, superior fuel consumption and durability. Therefore the number of diesel engine in the world is increasing. As the seriousness of environmental pollution increases in the world, the method to reduce the noxious materials of CO2, NOx and P.M. is very important subject to correspond to exhaust gas regulations. A new concept, so called premixed charge compression ignition(PCCI), is focused among the various corresponding manners. In this study, we investigated the combustion characteristics of PCCI engine using a mixed fuels with that of commercial diesel engine. Finally we grasped a emission characteristics of PCCI engine. From this experiment, it could be found that NOx reduction is caused by the lower maximum temperature and soot reduction is caused by rapid combustion under diffusion combustion part. Also, it was found that 1st-combustion(cool flame) and 2nd-combustion(hot flame) is appeared in heat release curve, exhaust gas temperature is diminished and combustion variation is increased according to increasing of gasoline ratio.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3329-3334
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• 2007

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduce way NOx and PM. The pressure diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured; we estimated it by CHEMKIN calculation. DME HCCI characteristic is surveyed. Validations of the CHEMKIN calculation were confirmed pressure rise of an experiment and pressure rise of a calculation. Using a framing streak camera captured two dimensional spontaneous luminescence images from chemical species at low temperature reaction(LTR) and high temperature reaction (HTR). Also, the combustion events were observed by high-speed direct photography, the ignition and combustion were analyzed by the combustion chamber pressure profiles.