• 한국대기환경학회지
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• 제26권4호
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• pp.403-411
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• 2010

Recently, emission tests for heavy-duty vehicles have been conducted by heavy-duty engine dynamometer. But, it contains weaknesses that present inconveniences to install and uninstall engines and limitations to reflect on practical characteristics for vehicle driving. On the other hand, chassis dynamometer test is able to differentiate characteristics of real driving patterns due to the reason that vehicles can be examined by utilizing chassis dynamometer. This study aimed at comparing the characteristic of emitting regulatory substances of urban buses on Heavy-duty chassis dynamometer. The characteristic was analyzed based on vehicle speed by using both domestic and overseas developed heavy-duty vehicle test modes. As a result, this work attempted to investigate possibilities to take advantage of Heavy-duty vehicle test modes as a method to manage emissions from heavy-duty vehicles.

• 한국자동차공학회논문집
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• 제23권3호
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• pp.307-314
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• 2015

The purpose of this study is know the fuel economy of difference tractive resistance calculation methods on light duty low-floor bus. Two tractive resistance calculation methods(coastdown test and JFCM conversion formula) are tested to understand the difference of fuel economy. JFCM was developed for fuel economy regulations of heavy duty vehicle. That show a big difference as a result of the calculation using coastdown test and JFCM conversion formula. The difference of the tractive resistance affects the fuel economy.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 추계학술대회 논문집
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• pp.127-128
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• 2006

• 한국안전학회지
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• 제24권4호
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• pp.1-10
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• 2009

The characteristics of smoke emissions from diesel heavy duty vehicles which weigh over 5.5 tons was investigated by driving the vehicles with both the Lugdown 3 modes in the chassis dynamometer and tree accelerating mode under no load. The vehicles include commercial vehicles such as bus, microbus, trucks and specialized vehicles, etc. The total numbers of the vehicles tested were 200. The light extinction method was used to measure the smoke emissions from the vehicles tail pipe. The values of the smoke emissions in the tree accelerating mode showed $0{\sim}20%$ band nearly independent of both the mileage and year of production of the tested vehicles, while those in the Lugdown 3 modes showed $0{\sim}99%$ of wide band. The correlation coefficients between the values of the smoke emissions with both the Lugdown 3 modes and the free acceleration mode were 0.12, 0.08, 0.12, respectively. The inspection with Lugdown 3 modes is better one than that with tree acceleration from the point of exact inspection of the diesel vehicles' smoke emission.

• 한국분무공학회지
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• 제23권2호
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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.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.165-173
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• 2014

The method of emission inspection for Heavy-duty diesel vehicles has been engine speed type Lug-down 3mode. This method could bring damage to decrepit vehicles under high speed and high load condition and it could not apply the driving pattern on the road. For these reasons, this study has started to create new emission inspection which is appropriate for Korea's road infrastructure. KD 147 would be applied to light-duty diesel vehicles from july 2010 after model operations. Therefore, this study has investigated new emission inspection system for heavy-duty diesel vehicles, except for light-duty diesel vehicles. In consideration of domestic conditions to meet the new load test method in this study, the Lug-down3 mode vehicle speed method was developed for the first time in korea.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.634-639
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• 2012

The contribution levels of emissions from the heavy-duty vehicles have been continuously increased. Among the exhaust emissions, NOx (nitric oxides) have a ratio of 73.2% and particle matters have a proportion of 61.8% in the heavy-duty vehicles. Also, natural gas vehicles have the 78.9% of total registered local buses in Korea. Therefore, the investigation on emission characteristics of heavy-duty vehicles using CNG and diesel fuel according to the various driving cycles was carried out in this study. In order to analyze the emission characteristics, the five kinds of buses by using CNG and diesel fuels with a after-treatment devices (DPF, p-DPF) was used and five test driving schedules were applied for analysis of emission characteristics in a chassis dynamometer. To analyze the exhaust emission, the exhaust emission and PM analyzers were used. From this study, it is revealed that diesel buses with after-treatment had reduced emission of CO, HC, PM but NOx. Also, NMHC emission of CNG bus have a higher level and NOx level was similar with diesel buses. In addition, emissions in NIER06 with slow average speed shows lowest levels compared to other test modes.

• 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%).

• 한국자동차공학회논문집
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• 제21권6호
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• pp.1-7
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• 2013

This paper focuses on cooling fan control by using a magnetic clutch type for the improvement of fuel economy on a heavy city bus. In general, Heavy duty vehicles use viscous clutch type cooling fan which has some disadvantages, such as slow response, wide temperature variation of engine coolant water. But a magnetic clutch type cooling fan can be controlled electronically so the engine coolant temperature can be precisely controllable and this effects could be used to reduce fuel consumption. A control system for applying the magnetic clutch type cooling fan was developed in this study and applied to the real field test and chassis dynamometer test. The result showed well controlled coolant temperature and enhancement of fuel economy.

• 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.