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이성욱(Seangwock Lee),송영모(Youngmo Song),백두성(Doosung Baik) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.7
A parametric study was made to understand the fundamentals of combustion of CNG fuel in a constant volume chamber in the respect of swirl effect, and the numbers of spark ignition. Optical devices were applied for the visualization of the physics of combustion, and combustion pressures and exhaust emission were measured at several equivalence ratios by controlling speeds of a swirling motor. When the speed of a swirling motor was raised the combustion conditions were improved. The corresponding maximum combustion pressure and heat release rate were increased and the speed of flame propagation was getting faster. This research may contribute to improve the performance of CNG engine and reduce emissions in future.
정적연소기내 Hythane의 연소 및 배출 가스 특성에 관한 실험적 연구
이한승(Hanseung Lee),이성욱(Seangwock Lee),문성은(Seungeun Moon),김성대(Sungdae Kim),이영철(Youngchul Lee),조용석(Yongseok Cho),백두성(Doosung Baik),김창기(Changgi Kim) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11
Finding an alternative fuel and solving the environmental pollution are the main targets for the future internal combustion engines. Hythane(Hydrogen-Methane) as a fuel is now considered as one of the alternative fuels due to its low pollutant emissions and high burning rate. An experimental study was carried out to obtain the fundamental data about the combustion and emission characteristics of pre-mixed hydrogen and methane in a Constant Volume Chamber(CVC) with various fractions of hydrogen?methane blends. A pre-mixed chamber was used to obtain a good mixture of the above gas. Exhaust emissions were measured using Horiba exhaust gas analyzer, for various fraction of hydrogen?methane blends. The results showed that the rapid combustion duration was shortened and rate of heat release increases as hydrogen fraction in fuel blends ratio was increased. Moreover, the maximum mean gas temperature and the maximum rate of pressure rises also increases. These phenomena were attributed to the burning velocity which increases exponentially with the increase of hydrogen fraction in fuel blends. Exhaust HC and CO2 concentration decreased while NOx emission increased with the increase of the hydrogen fraction in fuel blends. The knowledge from this experiment will facilitate the application of hydrogen along with Methane as a fuel to the current fossil hydrocarbon based economy and for the strict emission regulations in internal combustion engines.
DME 엔진용 LNT(Lean NO<SUB>x</SUB> Trap) 촉매의 배기가스 온도 및 공간속도에 따른 NO<SUB>x</SUB> 저감특성에 관한 실험적 연구
이찬희(Chanhee Lee),박영준(Youngjoon Park),윤여빈(Yubin Yoon),이성욱(Seangwock Lee),조용석(Yongseok Cho) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11
DME fuel has got attention as an alternative fuel because of the extremely low level of PM emissions. DME fuel engines still emit the same level of NOx emissions as diesel engines. The LNT(Lean NOx Trap) catalyst is an aftertreatment system typically used to reduce the oxides of nitrogen(NOx) emissions for diesel engine. During the lean condition of exhaust gas, the NOx is stored in the LNT catalyst, then released and reduced during the rich condition of exhaust gas. This paper aims to figure out the effects of exhaust gas temperature and space velocity on the reduction performance of the LNT system.
상용차용 펠티어 냉난방장치의 공기저항 저감을 위한 수치해석 연구
이정희(Junghee Lee),윤여빈(Yubin Yoon),이성욱(Seangwock Lee),조용석(Yongseok Cho) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11
This study suggests peltier air conditioning system external shape to improve the aerodynamics performance through computational fluid dynamics. The study was focused on modifying the nose section of peltier air conditioning system that had the largest contribution to the drag force. The nose section was modified to gradually angled shape. The results of the analysis for the peltier air conditioning system showed that with nose section modifications the coefficient of drag could be reduced by approximately 18%.
디젤기관의 EURO-6 배기규제 대응을 위한 Urea-SCR 모델의 NOx 및 NH₃ 배출 특성 연구
서준협(Junhyeop Seo),이성욱(Seangwock Lee),조용석(Yongseok Cho),강연식(Yeonsik Kang) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
The Selective Catalytic Reduction(SCR) system is a highly-effective device for NOx reduction of diesel engines. Generally, the ammonia(NH₃) was generated from reaction mechanism of urea solution in the SCR system using the liquid urea as the reductant. Therefore, the precise urea dosing control is a very important factor for reducing NOx and NH₃ slip in the SCR system. In this study, same exhaust gas composition was used in the rig test bench according to exhaust gas temperature and space velocity to analyze characteristics of NOx and NH₃. Parameter indentification of the proposed SCR model is performed using the rig-test experimental data sets. Then, simulations are performed to validate the proposed SCR dynamic system. Thus, the results of this study aim at development of SCR control algorithm to maximize NOx reduction efficiency and minimize NH3 slip through urea injection control strategy.