• Journal of ILASS-Korea
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• v.23 no.2
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• pp.74-80
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• 2018

Emission characteristics of regulated pollutants (CO, NOx, HC and PM) and hazardous air pollutants (HAPs) from diesel heavy duty trucks equipped with EGR+pDPF and SCR for Euro 5 emission standards were investigated using a chassis dynamometer. In the case of regulated pollutants, diesel heavy duty trucks with EGR+pDPF emitted 79% less CO than those with SCR. Also, those with the SCR emitted 36% less NOx than those with the EGR+pDPF. The results of VOCs have show that alkanes emissions for heavy duty trucks with the EGR+pDPF and the SCR have been higher than alkenes, cycloalkanes and aromatics. In the case of individual VOCs, the highest of propene emissions for 11.3~16.1% occupied. For aromatics group, benzene emissions are the highest percentage for 4.4~15.5%. In the future, the results of present study will provide basic data to set up HAPs emissions inventory for mobile source.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.48-54
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• 2004

The purpose of this work is to investigate the effect of premixing condition on the combustion and exhaust emission characteristics in a HCCI diesel engine. To from homogeneous charge before intake manifold, the premixed gasoline fuel is injected into a premixed tank by fuel injection system and the premixed gasoline fuel is ignited by direct injected diesel fuel. Experimental result shows the NOx and soot emissions are decreased linearly with the increase of premixed ratio. In the case of intake air temperature $20^{\circ}C$ with light load, the specific fuel consumptions are increased with the rise of premixed ratio and HC and CO emissions are also increased. But the intake air heating can improve the specific fuel consumption at light load condition because increased air temperature promotes the combustion of premixed mixture. In the case of high intake air temperature with high load condition, premixed fuel is auto-ignited before diesel combustion and soot emission is increased.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.699-703
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• 2000

Experiments were carried out to investigate the characteristics of the hydrocarbon (HC) emissions and to reduce cold start hydrocarbons in gasoline engines. An HC adsorber was, used and it coated was by Pd/Rh catalyst with zeolite on a honeycomb monolith. The HCs were efficiently trapped at temperatures below $100^{\circ}C by physical adsorption. After adsorption, they were reduced gradually by the catalytic oxidation of Pd/Rh catalysts as the adsorber temperature increased above $100^{\circ}C. Increasing amounts of methane, ethylene and n-butane were emitted as the fuel-air mixture became richer and the engine speed decreased. As the temperature of adsorber increased, high-number carbons into low-number carbons. Thus, the C4 concentration decreased significantly during the first 30 seconds, and the C2 concentration increased continuously.

• Journal of Hydrogen and New Energy
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• v.27 no.4
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• pp.441-446
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• 2016

Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and methanol gasoline blended fuels in a spark ignition engine. This experimental results showed that alcohol gasoline blended fuels decreased the torque, brake mean effective pressure, and brake power decreased when alcohol blended fuels were applied to a gasoline engine and also CO, HC and NOx emissions were reduced in accordance with the contents of alcohol contents.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.721-726
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• 2016

Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and diesel blended fuels in a compression ignition engine. This experimental results showed that ethanol diesel blended fuels decreased the torque and brake mean effective pressure. And experimental results indicated that using ethanol-diesel blended fuel, smoke, CO and HC emissions decreased as a result of the ethanol addition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.788-792
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• 2006

The test was conducted on an 8000cc heavy-duty turbo-charged heavy-duty diesel engine on which continuous regeneration DPF was installed in order to investigate regeneration characteristics fur DPF and engine performance under conditions of standard (430ppm) or ultra low sulfur diesel (50ppm) and the results were compared with each other. Exhaust emissions, CO, HC, NOx, PM and soot were investigated carefully and tested under D-13 and D-3 modes.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.4
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• pp.912-919
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• 2001

Improvement of the atomization characteristics by adopting the air-shrouded injector has been considered as one of the important methods for decreasing HC emissions in SI engines. Thus, in this study to develop air-shrouded injector with a finer spray, atomization characteristics of differ-ent types of commercial air-shrouded injectors were investigated through the spray imaging and the drop size measurements. As a results, it was found that the internal mixing type of air-shroud-ed injector had a good atomization characteristics. But, a number of large droplets were found in the internal mixing type commercial injector, this shortcoming was improved by adopting the thread type air passages in the air nozzle.

• Journal of ILASS-Korea
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• v.25 no.1
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• pp.27-33
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• 2020

NOx, PN and CO emissions from diesel trucks make up a significant portion of domestic air pollutant emissions. Therefore, test vehicles with various emission standards and driving modes were selected to evaluate the emission characteristics of regulated pollutants (NOx, PN, CO) in medium-duty trucks. As a result of test, all test vehicles were satisfied with Euro 5 or 6 regulation. NOx emissions of Euro 6 vehicles with after-treatment of LNT + DPF were lower than those of Euro 5 vehicles with DPF. In WLTC mode, all vehicles have high NOx emissions at section of extra high speeds, which are determined by increased fuel consumption and high combustion temperatures. CO and PN emissions from all vehicles were found to be low at section of low speeds. Also, The NO₂/NOx ratio was analyzed at 7-23% in each mode, and the NO₂/NOx ratio increased as the average vehicle speed increased. In NIER 9 mode, the CO, HC, and PN emissions were higher under cold conditions of engine than hot conditions of engine. In addition, vehicles with after-treatment system of LNT have similar NOx emissions level in this study.

• 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.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.146-151
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• 2004

The characteristics of combustion and emission of biodiesel fuel were investigated in a single cylinder DI diesel engine equipped with a common rail injection system. For investigating the effect of bio diesels, the experiments were conducted at various mixing ratio and engine operation conditions. Experimental results show that combustion pressure increased with the increase of mixing ratio and injection pressure. The HC and CO emissions are decreased and NOx emission is increased as the mixing ratio of biodiesels increases at 100MPa injection pressure. However the results of the emissions are shown the contrary to the results at 50MPa of injection pressure due to larger droplets of biodiesel sprays.