• 한국자동차공학회논문집
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• 제7권9호
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• pp.20-27
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• 1999

The proportion of diesel vehicle is very high in this country . PM and NOx emitted from diesel-posered vehicle is severely ;affecting to be air quality . Especially, diesel particulate matters(DPM) including black smoke are hazardous air pollutants to human health and environment. In order to reduce the exhaust emissions from diesel engines, it is necessary to analyze the characteristics of exhaust emissions from diesel engines in various driving conditions. Recently, there are occasion to increase the fuel consumption rate to engine power up. So, in this study we have tested a diesel engine detached from in use -diesel vehicle and analyzed exhaust emission by driving condition and fuel dispersion rate. From this results, we will prepare the comprehensive management plan for exhaust emissions from diesel vehicles and contribute to the improvement of air pollution in urban area.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.56-63
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• 2007

Modern diesel vehicle has to comply with the EURO IV, V regulation with low level of particulate matter and smoke emission Moreover, emission standards of each countries are becoming stringent in advanced countries such as USA and Europe. Because Bio-diesel is similar to diesel fuel, it is essential to judge the environmental and health effects deriving from the use of Bio-diesel in diesel engine. The deterioration characteristics of emission in accordance with aging vehicles must be regulated for Bio-diesel. Therefore, under 1200 driving hours, 220,000km driving distance condition and full load, the deterioration characteristics of emission were estimated. We could reduce sulfur contents of fuel, particulate matter and smoke emission by using Bio-diesel and conform the influence of engine performance, emission, and fuel consumption by Bio-diesel deterioration

• 한국대기환경학회지
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• 제16권5호
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• pp.529-537
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• 2000

Several Pt-based oxidation catalysts with different loading were prepared with various metal precursor solutions and characterized with H$_2$ chemisorption and TEM for Pt particle size. V was added to Pt-based catalyst for inhibiting SO$_2$oxidation reaction, as result, Pt-V/Ti-Si catalyst prepared by ERMS(Free Reduced Metal in Solution) method showed high enough activity and better inhibition on SO$_2$oxidation than Pt only catalyst. Optimum Pt particle size for diesel oxidation reaction turned out to be the size of around 20 nm. A prototype catalyst was prepared for light=duty diesel passenger car, and teated for the emission reduction performance with Korean regulation test mode(CVS-75 mode) on chassis dynamometer. The catalyst shows the performance reduction of 75~94% for CO, 53~67% for HC and 10~31% for PM. In the case of heavy-duty diesel catalyst, the domestic formal regulation teat mode D-13 was adopted for both Na engine and Turbo engine. The conversions of CO and THC are high enough(86% and 41%) while the reductions of NOx and PM are relatively low(3~11%).

• Journal of Mechanical Science and Technology
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• 제19권3호
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• pp.870-876
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• 2005

It seems very difficult to comply with upcoming stringent emission standards in vehicles. To develop low emission engines, better quality of automotive fuels must be achieved. Since sulfur contents in diesel fuels are transformed to sulfate-laden particulate matters as a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied. In general, flash point, distillation $90\%$ and cetane index are improved but viscosity can be worse in the process of desulfurization of diesel fuel. Excessive reduction of sulfur may cause to degrade viscosity of fuels and engine performance in fuel injection systems. This research focused on the performance of an 11,000 cc diesel engine and emission characteristics by the introduction of ULSD, bio-diesel and a diesel oxidation catalyst, where the bio-diesel was used to improve viscosity of fuels in fuel injection systems as fuel additives or alternative fuels.

• 대한기계학회논문집B
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• 제36권4호
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• pp.371-376
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• 2012

본 연구에서는 대형버스 배기가스 테스트 모드인 JE-05 에서 DME와 디젤을 연료로 사용하는 대형 DME버스를 차대동력계, 배기가스 분석기 그리고 PM 측정시스템을 이용하여 대형 DME버스의 연비, 배기가 스특성 그리고 동적 특성에 대해 알아보았다. 대형 DME버스에는 6기통 8,071cc 디젤엔진이 장착되었으며, 현재 운행되고 있는 상용 디젤버스와는 달리 DOC, DPF와 같은 후처리 장치가 없다. 실험 결과, 각 부하에 따른 차량의 속도를 통하여 차량의 동적 특성은 DME와 디젤을 사용했을 때 거의 비슷한 것을 알 수 있었다. NOx, CO와 THC는 DME를 연료로 사용 시 디젤연료에 비해 더 적게 배출되는 것을 확인하였다. 하지만 PM은 DME연료를 사용 시 거의 발생하지 않았는데, 이는 DME가 함산소연료이고 분자구조상 탄소-탄소 결합이 없기 때문이라고 생각된다. $CO_2$는 각 연료 사용 시 비슷하게 발생하였으며, 저위발열량 베이스로 계산된 연비는 DME연료 사용 시 디젤연료보다 약 6.7% 더 낮게 나왔다.

• 한국자동차공학회논문집
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• 제4권4호
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• pp.164-170
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• 1996

Among after treatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects on factors of oxidaton characteristics and conversion efficiency of DOC. We tested to estimate change of engine performance whether a 11,000cc diesel engine equipps with DOC or not. We conducted test to estimate the reduction efficiency of exhaust gas in P-5 mode, in D-13 mode of heavy duty diesel regulation mode and in somoke opacity mode for two samples and also we conducted test to analyze the effects about both exhaust gas velocities 1,100rpm and 2,200rpm

• 한국분무공학회지
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• 제29권2호
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• pp.53-59
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• 2024

Cars are one of the main causes of air pollution in large cities, and 34.6% of domestic air pollution emissions come from mobile sources, of which cars account for 69.6%. In particular, the importance of nitrogen oxides (NOx) and particulate matter (PM), which are major pollutants in diesel vehicles, is increasing due to their high contribution to emissions. Therefore, in this study, the problem of natural regeneration caused by low exhaust gas temperature during low speed and low load operation was solved by applying a complex regeneration DPF that is not affected by temperature conditions to large diesel vehicles with higher driving time and engine displacement than small and medium-sized vehicles. And the feasibility of application to large diesel vehicles was reviewed by measuring the emission reduction efficiency. As a result of the reduction efficiency test on the actual vehicle durability product, PM showed a reduction efficiency of 84% to 86%, and the reduction efficiency of gaseous substances showed a high reduction efficiency of over 90%. The actual vehicle applicability test was completed with three driving patterns: village bus vehicle, police car, and road-going construction equipment vehicle, and no device problems occurred until the end of the test. Both load and no-load smoke measurement results showed a smoke reduction efficiency of over 96%.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.97-103
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• 2003

Currently, due to serious increase of pollution scones, lots of technology has been involved to reduce exhaust gas in diesel engine. But the amounts of exhaust gas can not be decreased somehow due to the increase of diesel vehicles. Moreover, emission standards of each counties are being stringent in advanced countries such as USA and Europe. In the near future, sulfur contents in fuel must be essentially reduced f3r health and environment because sulfur can basically reduce exhaust gas. Therefore, when will be applied to Bio-diesel and ULSD, they could reduce sulfur contents of fuel without aftertreatment and might conform the influence of engine performance, emission, smoke and fuel consumption.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.16-21
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• 1999

The diesel vehicle is relatively superior to gasoline vehicle on the fuel consumption, durability and combustion efficiency. However, exhaust emission from diesel vehicle are known to be harmful to human health and environment. The treatment technologies for the diesel exhaust gases are classified as replacement of fuel, quality control of diesel fuel, improvement of engine and aftertreatment system. The most effective for the treatment technology is known to be aftertreatment system, and this research is continuously conducted by many groups. The DOC system has many advantages of reducing particulates and harmful gaseous substances such as CO. HC. Moreover, it is simple in device structure, relatively low cost, and easy to install witout retrofitting the vehicle. In this study, experiment were conducted to analyze the effects on factors of oxidation characteristics and conversion efficiency of DOC. In experiment, test was conducted to estimate engine emission in 11,000cc diesel engine which was equipped with DOC.

• 동력기계공학회지
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• 제8권1호
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• pp.18-23
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• 2004

The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments-were performed at various engine loads while the EGR rates were set from 0% to 20%. The emissions trade-off and combustion of diesel engine are investigated. Hot and cooled EGR are achieved without cooling and with cooling respectively. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions. Also, the reduction rates of NOx emissions for hot and cooled EGR are similar at load 20%.