• Transactions of the Korean hydrogen and new energy society
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• v.14 no.2
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• pp.138-145
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• 2003

There are high expectations for DME(Dimethyl Ether) as a new alternative fuel for diesel engine. Compared with the conventional diesel engine, nearly zero soot emission and high thermal efficiency have been reported from DME fuelled CI engines. However, higher NOx emission is one of the disadvantages from DME Engines. In the present study, cooled EGR(Exhaust Gas Recirculation) was applied to DME engine modified from conventional Dl diesel engine, and effects of EGR were examined under various EGR temperature. Finally, it was concluded that the cooled EGR is an effective solution to reduce NOx emission from DME engine.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.609-615
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• 2015

In this study, the combustion and exhaust emission characteristics in a gasoline direct injection engine with variations of the bio-ethanol-gasoline blending ratio and the excess air factor were investigated. To investigate the effects of the excess air factor and the bio-ethanol blends with gasoline, combustion characteristics such as the in-cylinder combustion pressure, rate of heat release (ROHR), and the fuel consumption rate were analyzed. The reduction of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and nitrogen oxides ($NO_x$) were compared with those of gasoline fuel with various excess air factors. The results showed that the peak combustion pressure and ROHR of bio-ethanol blends were slightly higher and were increased as bio-ethanol blending ratio is increased. Brake specific fuel consumption increased for a higher bio-ethanol blending ratio. The exhaust emissions decreased as the bio-ethanol blending ratio increased under all experimental conditions. The exhaust emissions of bio-ethanol fuels were lower than those of gasoline.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.2
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• pp.153-159
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• 2004

The purpose of this research is to investigate the performance of swirl combustion chamber diesel engine by changing the jet passage area, the depth and shape of the piston top cavity (main chamber). The performance of diesel engine with newly changed swirl combustion chamber was tested through the experimental conditions as engine speed, load and injection timing etc. The test results were compared and analyzed. And another purpose of this research is to make a new diesel engine that is satisfied fuel consumption and regulation value of exhaust gas. 1. The rate of fuel consumption was affected significantly by the jet passage area at the high speed and load than low speed and low load. The influence of jet passage large area was proven to decrease the rate of fuel consumption. 2. Smoke was affected significantly by the depth of the piston top cavity, but exhaust temperature and the rate of fuel consumption wasn't affected. The rate of fuel consumption was affected by changing injection timing. 3. The rate of fuel consumption, exhaust temperature and Smoke were affected significantly by the shape of the piston top cavity from rectangular to trapezoid. That is we have all high value. The exhaust smoke density and exhaust gas temperature depended sensitively on variation of the injection timing rather than the shape of the combustion chamber within the experimental conditions. 4. We made a new diesel engine that is satisfied design target values(sfc=190 g/hr, NOx + THC=6.0 g/KWh, PM=0.3 KWh), the rate of fuel consumption and emission standard etc., through changing injection timing at the maximum torque point and rated power point. Although we have a little high NOx value.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.136-138
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• 2000

The vehicle emissions of primary air pollutants are described by the emission factor (EF), defined as the emitted mass (g) of a compound per distance (km) and vehicle. The EF can be determined by exhaust measurements from single vehicles in dynamometric tests. However, the EF of a large number of vehicles has to be measured to obtain the representative results for actual road traffic emissions. Road traffic emissions can also be determined by exhaust measurements of driving vehicles or in tunnel measurements. (omitted)

• Journal of the korean Society of Automotive Engineers
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• v.9 no.6
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• pp.53-59
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• 1987

The effect of the three types of fuel vaporizing device on the engine torque and exhaust emission was investigated. Among the three types of fuel vaporizing device designed for the experiments, a 88mm long device with mesh around the inside pipe showed stable lean mixture combustion up to 21:1 air-fuel ratio and reduced the exhaustion of CO and HC. Compared with the general trend in the decrease of engine torque it was observed that the decrease of engine torque in this lean mixture combustion with the new device was small.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.267-267
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• 2017

• Journal of Environmental Science International
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• v.8 no.1
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• pp.27-32
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• 1999

This study identified concentrations of all pollutants emitted from idling of vehicles such as cars, taxis, trucks, and buses. In this investigation we analyzed concentrations of $SO_2$, NOx, CO, and $CO_2$ omitted from exhaust pipe of vehicles as a function of vehicle type, mileage, exhaust volume, and fuel type using the GreenLine. Compact or light cars, which have relatively low exhaust volume, showed much higher exhaust concentrations of $CO_2$, CO, and NOx than those emitted from vehicles with high exhaust volume. Vehicles using light oil showed much higher exhaust NOx concentrations than those of vehicles using gasoline. Vehicles using LPG and compact cars showed very high exhaust CO concentration compared to other vehicles. NOx exhaust concentrations were increased with increasing the mileage of vehicles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.196-205
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• 2016

The exhaust gas discharged by cars not only threatens the health of the human body, but also contributes to global warming, due to the resulting increase in the concentrations of ozone, fine dust and carbon dioxide. Therefore, the government has steadily implemented careful inspection systems for exhaust emissions, in order to efficiently regulate the exhaust gas of cars. Studies on reducing the exhaust emissions of automobiles have been conducted in various fields, including ones designed to reduce the generation of HC, NOx, and $CO_2$ in the exhaust emission of vehicles. However, there have been insufficient studies on the reduction of the exhaust emission for old diesel vehicles. To develop careful inspection systems for the exhaust emissions of old diesel vehicles, studies on the reduction of the exhaust emissions and improvement of power are necessary by cleaning the carbon sediment in both the intake manifold and injector. Therefore, in this study, we analyzed and compared the amounts of gas emitted when simultaneously cleaning or not cleaning the intake manifold and injector of diesel automobiles with mileages over 80,000 km and operating periods over 5 years. The experimental results showed that in the case where the intake manifold and injector were simultaneously cleaned, there was a decline of 75.2% in the gas emission compared to the cases where only the manifold or injector is cleaned. Also, it was found that simultaneously cleansing the intake manifold and injector enabled the exhaust standard to be satisfied for less than 30% within 8.5 sec.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.223-236
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• 2016

On-road source emissions are major air pollutants and have been associated with serious health effects in Seoul metropolis. Thus, it is of fundamental importance to have an accurate assessment of vehicle emissions in order to implement an effective air quality management policy. As a result, there is a need to overview vehicle emission characteristics of air pollutants. This article discusses vehicle exhaust sampling and chemical analysis, emission characteristics of air pollutants, and emission regulations from passenger cars. The vehicle exhaust sampling and chemical analysis methods were described in particulate matter and gaseous compounds. In this article, chassis dynamometer, measurement instrumentation for nano-particulate matter and carbon compounds analysis device were described. For the gasoline and diesel vehicles, the effective parameters of emissions were average vehicle speed, vehicle mileage and model year. The particle number emissions for diesel nano-particles were sensitive to the sampling conditions. Also, the particle number emissions with a diesel particle filter (DPF) largely reduced rather than those without it. This article also describes different emission characteristics of air pollutants according to biodiesel or bioethanol mixing ratio. The Korean emission standards for passenger cars were compared with those of the US and EU. Finally, the objective is to give an overview of relevant background information on emission characteristics of air pollutants from passenger cars in Korea.

• Particle and aerosol research
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• v.5 no.3
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• pp.139-148
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• 2009

In Seoul, the largest emission source for volatile organic compounds (VOCs) based on the emission inventory is solvent usage followed by vehicular exhaust. However, according to a CMB modeling result by Na and Kim (2007), vehicular exhaust was the largest emission source followed by solvent usage. Detailed analyses on the validity of the CMB model result were carried out and it was suggested that the existing emission inventory for VOCs might be underestimating vehicular emission. Scientific considerations that should be considered for the effective control strategy against VOCs are discussed.