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Post Injection을 이용한 Diesel Engine의 Turbo Lag개선 및 가속성능 향상
윤동필(Dongpil Yoon),박상운(Sangun Park),이근봉(Keunbong Lee),박영현(Younghyun Park),김숭기(Soongkee Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
Growing concern about increasing greenhouse gases (GHG) today, automobile industry is highly requiring stricter emission regulations and improved fuel consumption. It means that engine development should be more focused on a high efficiency and small displacement engine. To achieve for this demand, one of the effective method is reduction of the engine size by using a turbocharger or supercharger. Turbocharged boost technologies are able to increase thermal efficiency. However, the turbocharged downsized engines generally have worse response than the naturally aspirated (NA) engines because it takes a few seconds to get the turbocharger rotate up to high speed, usually called "Turbo-lag". In order to solve this matter, one possible way is hard solution: some changes in intake/exhaust layout and turbo inertia can be considered, or more sophisticated systems such as a two-stage turbocharger or a supercharger. Different way is soft solution to avoid it: some variables to control the turbocharging systems are optimized. This paper deals with the transient response of a common rail diesel engine with variable geometry turbocharger (VGT). In the paper, a DFSS method was used and also analyzed each factor which influence to turbo lag. The researches discussed focused on soft solution from the result of this analysis. The control strategy is based on the optimization of post injection with conventional VGT control at various transient engine conditions. Also, we developed the algorithm of driver’s intention to accelerate rapidly based on the driver demand. Reflecting driver’s intention selectively, the control strategy for transient response is capable of improving the vehicle acceleration performance with minimum deterioration of total smoke emissions and fuel consumption during the sudden acceleration.
연료 공급관의 가열이 분사연료의 미립화에 미치는 영향에 대한 실험적 연구
선우명호(Myoungho Sunwoo),천동필(Dongpil cheon),윤팔주(Paljoo Yoon),박승범(Seungbum Park),어윤한(Yoonhan Eo) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.5_1
This paper presents a strategy to deal with upcoming ULEV regulations. Usually the HC emission is caused by poor fuel atomization during the cold starting and warm-up period.<br/> Improvement on fuel atomization is planned by heating the fuel in fuel-rail. In this experiment, the heated fuel-rail system is constructed to investigate the reduction effects on the size of the fuel droplet by fuel heating. The fuel atomization is examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from three different types (two-hole, pintle, and six-hole) of injector based upon the returnless heated fuel-rail system.<br/> The result shows that the six-hole type injector with the heated fuel provides the best fuel atomization result in terms of SMD among three different types of injector.<br/>