• 한국응용과학기술학회지
• /
• 제35권4호
• /
• pp.1108-1119
• /
• 2018

대기오염에 대한 관심은 국내 외에서 점진적으로 상승하고 있으며, 자동차 및 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 위해 새로운 엔진 설계, 혁신적인 후 처리 시스템 등의 많은 접근을 통하여 차량 배출가스와 온실가스를 감소시키려고 노력하고 있다. 이러한 연구들은 주로 차량의 배출가스 (규제 및 미규제물질, PM 입자 배출 등)와 온실가스의 두 가지 이슈로 진행되고 있다. 자동차의 배출가스는 환경오염과 인체에 악영향을 주는 많은 문제를 일으키고 있다. 이러한 배출가스를 줄이기 위하여 각국에서는 배출가스 시험모드를 새로 만들어 규제하고 있다. 2007 년부터 UN ECE의 WP.29 포럼에서 배출가스 인증을 위한 전 세계의 조화된 light-duty 차량 시험 절차 (WLTP)가 개발되었다. 이 시험 절차는 유럽과 동시에 국내 light-duty 디젤 차량에도 적용되어졌다. Light-duty 차량의 대기오염 물질 배출량은 거리 당 무게로 규제되어 있어 주행주기가 결과에 영향을 미칠 수 있다. 차량의 배출가스는 주행 및 환경조건, 주행습관 등에 따라 크게 달라진다. 극단적인 외기온도는 배출가스를 증가시키는데, 이것은 더 많은 연료가 실내를 가열하거나 냉각해야하기 때문이다. 또한 높은 주행속도는 증가된 항력을 극복하기 위해 필요한 에너지로 인해 배출가스 량을 증가시킨다. 일반적으로 상승하는 차량속도와 비교할 때, 급격한 차량가속도도 배출가스를 증가시킨다. 부가적인 장치 (에어컨 또는 히터)와 도로경사 또한 배출가스를 증가시킨다. 본 연구에서는 3대의 light-duty 차량을 가지고 light-duty 차량의 배출가스 규제에 사용되는 WLTP, NEDC 및 FTP-75로 시험을 하였으며, 배출가스가 다른 주행 사이클에 의해 얼마나 많은 영향을 받을 수 있는지를 측정하였다. 배출 가스는 통계적으로 의미있는 차이를 보이지 않았다. 최대 배출 가스는 주로 냉각 된 엔진 조건에 의해 야기되는 WLTP의 저속 단계에서 발견된다. 냉각 된 엔진 상태에서 배출가스의 양은 시험 차량과 크게 다르다. 이는 WLTP 구동 사이클에 대처하기 위해 다른 기술적 솔루션이 필요하다는 것을 의미한다.

• 한국자동차공학회논문집
• /
• 제15권2호
• /
• pp.58-64
• /
• 2007

As the concerns regarding global worming were increased, the pressure of greenhouse gas(GHG) emission reduction on mobile source was also increased. Carbon dioxides contribute over 90% of total GHG emission and the mobile source occupies about 20% of this $CO_2$ emission. Therefore automotive exhaust is suspected to be one of the major reasons of the rapid increase in greenhouse effect gases in ambient air. In this study, in order to investigate $CO_2$ emission characteristics from gasoline passenger cars(PC), which is the most dominant vehicle type in Korea, 106 vehicles were tested on the chassis dynamometer. $CO_2$ emissions and fuel efficiency were measured. The emission characteristics by displacement, gross vehicle weight, vehicle speed and CVS-75/vehicle speed mode were discussed. Test modes were vehicle speed modes and CVS-75 mode that have been used to develop emission factors and to regulate for light-duty vehicle in Korea. It was found that $CO_2$ emissions showed higher large displacement, heavy gross vehicle weight, low vehicle speed and CVS-75 mode than small displacement, light gross vehicle weight, high vehicle speed and vehicle speed mode, respectively. From these results, correlation between $CO_2$ emission and fuel efficiency was also determined. The results of this study will contribute to domestic greenhouse gas emissions calculation and making the national policy for climate change.

• International Journal of Automotive Technology
• /
• 제7권1호
• /
• pp.9-15
• /
• 2006

Prediction of the performance of a carbon canister in vehicle evaporative emission control system has become an important aspect of overall fuel system development and design. A vehicle's evaporative emission control system is continuously working, even when the vehicle is not running, due to generation of vapors from the fuel tank during ambient temperature variations. Evaporative emissions from gasoline powered vehicles continue to be a major concern. The objective of this paper is to clarity the flow characteristics and other such fundamental data for the canister during loading and purging are needed, and this data will prove valuable in the development of the canister. This paper is to evaluate the relationship between carbon canister condition and engine performance during engine operation, and the effects of evaporative emissions on the engine performance were investigated.

• 한국자동차공학회논문집
• /
• 제8권4호
• /
• pp.51-58
• /
• 2000

It is well known that the majority of the emissions measured from vehicle exhaust in the US Federal Test Procedure(FTP-75) are emitted during the first 60 seconds. This paper describes an experimental study on SI engine emissions reduction after cold start with interval secondary air injection and coolant control. Secondary air injection after cold start to reduce exhaust emissions causes an exothermic reaction at the exhaust port and gives sufficient air to the catalyst. For that reason engine-out emissions oxidized in the exhaust port and the rapid heating of a catalytic converter after cold start with CSAI and ISAI are estimated. The influence of the coolant temperature on SI engine emissions has been estimated. In the present studycoolant control of the cylinder head tempeature is used to investigate the effect of coolant temperature on SI engine emissions. The results show that engine-out hydrocarbon and carbon monoxide emissions are considerably reduced with interval secondary air injection and coolant control.

• 에너지공학
• /
• 제13권2호
• /
• pp.161-165
• /
• 2004

Evaporative emissions from gasoline powered vehicles continue to be a major concern. The performance of carbon canister in evaporative emission control systems has become an important aspect of overall fuel system development and design. A vehicle's evaporative emission control system is continuously working, even when the vehicle is not running, due to generation of vapors from the fuel tank during ambient temperature variations. In this study, the effects of evaporative emissions on the engine performance were investigated. The experimental results show the effectiveness of this system for future exhaust emissions and enhanced evaporative emissions. This paper discusses the evaluation on the relationship between carbon canister condition and engine performance while engine is running.

• 한국분무공학회지
• /
• 제22권3호
• /
• pp.122-128
• /
• 2017

Currently, the proportion of diesel vehicles in all automobile has grown significantly over the past few years. Air pollutant also grew up and became a social problem. In particular, the issue of NOx emissions caused by NOx high emission in real driving has become a global issue. Despite the fact that the regulatory and reduction project of the new vehicle is actively carried out, there are no existence regulations of In-use diesel vehicle's NOx emission. Therefore, the emission characteristics of the in-use diesel vehicles were investigated to seek ways to reduce NOx emissions in this study. The test targets were used in 237 close inspection of exhaust gases and model year varied from 1996 to 2011. However, the classification of emissions by emission standards differed considerably from NOx emissions. This means that the selection method for early retirement targets should be converted from model year to amount of emissions. If the current early retirement program was applied to the existing system, pre-Euro 3 was 22.530 g/km and Euro 4 was 21.810 g/km to NOx reduction. However, when the vehicle was changed to high emission target vehicle, NOx reduction increase maximum 84.705 kg/yr. According to the study results, an effective reduction in NOx emissions can be achieved if an earlier target in expanded to Euro 4 vehicles.

• 한국대기환경학회지
• /
• 제21권6호
• /
• pp.649-655
• /
• 2005

Automotive exhaust is suspected to be one of the main reasons of the rapid increase in greenhouse effect gases in ambient air. Although methane emissions are generally orders of magnitude lower than emissions of $CO_{2}$, the global warming potential (GWP) of methane is greater than that of $CO_{2}$. The environmental impact of methane emissions from vehicles is negligible and is likely to remain so for the foreseeable future. In this study, in order to investigate greenhouse gas emission characteristics from gasoline passenger cars, 20 vehicles were tested on the chassis dynamometer and methane emissions were measured. The emission characteristics by model year, mileage, vehicle speed were discussed. Test mode is CVS-15 mode that have been used to regulate for light-duty vehicle in Korea. It was found that $CH_{4}$ emissions showed higher for cold start, old model year and long mileage than hot start, new model year and short mileage, respectively. These results were compared with IPCC emission factors and the overall our results were anticipated to contribute for domestic greenhouse gas emissions calculation.

• 한국산학기술학회논문지
• /
• 제12권10호
• /
• pp.4283-4287
• /
• 2011

본 논문은 현재 출시되어 있는 소프트타입의 현대 아반테 하이브리드자동차와 하드타입 방식의 도요다 프리우스 자동차를 대상으로 차대 동력계상에서 CVS-75 모드를 주행하면서 발생하는 배출가스특성과 연비특성을 실험적으로 분석하였다. 가솔린 차량에 비해 하이브리드 차량의 연비 및 배출가스 특성이 탁월하였으며 특히, 하드타입의 하이브리드 차량이 소프트타입의 차량에 비해 연비개선효과가 우수하게 나타났다.

• 한국분무공학회지
• /
• 제20권3호
• /
• pp.156-161
• /
• 2015

This paper described the effect of dual clutch transmissions on the stability emissions characteristic in a GDI engine at vehicle Inspection and Maintenance(I/M) program. In order to investigate the influence of direct injection gasoline engine with DCT, the experimental apparatus consisted of GDI engine with 4 cylinder, dynamometer and exhaust emissions analyzer. Analyzed emission gas include CO, HC and NOx results that DCT vehicle in the case of NOx, HC in automatic transmission vehicles less than 1/2 level was confirmed to be exhausted. However vehicle specific power increases CO also has increased.

• 한국자동차공학회논문집
• /
• 제23권1호
• /
• pp.130-138
• /
• 2015

Despite of recently strengthened vehicle emission regulations, NOx emissions are not decreased in urban areas because of discrepancies between certification emission test modes and real driving conditions. Thus, researches on RDE-LDV (Real-driving Emission-Light-duty Vehicle) have been conducted actively using PEMS (Portable Emissions Measurement Systems). In the present study, NOx emissions were measured for 5 Korean light duty vehicles for real driving conditions including city, combined, highway, and up-downhill test route. Emission characteristics were analyzed for averaged NOx emissions per unit driving distance of each driving test routes. Furthermore, MAW (Moving Average Window) method based on $CO_2$ emissions from WLTC, which will be supported for EU regulations, was utilized. It was revealed that DRs (deviation ratios) for diesel vehicles (i.e., 5.1 ~ 8.4) were greater than gasoline vehicles (less than 0.15). Especially DR of diesel vehicle for up-downhill test route was 8.4, which indicates severe NOx emissions.