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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.
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%.
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.
승용 디젤차량에서 Urea-SCR 시스템의 NOx 저감 특성에 관한 실험적 연구
박승원(Seungwon Park),이성욱(Seangwock Lee),조용석(Yongseok Cho),강연식(Yeonsik Kang) 대한기계학회 2017 大韓機械學會論文集B Vol.41 No.4
LNT(Lean NOx Trap), LNC(Lean NOx Catalyst), SCR(Selective Catalytic Reduction)과 같은 NOx 저감기술은 상용차뿐만이 아닌 승용차량 성능향상을 위해 지속적으로 개발이 진행되고 있다. 특히 Urea-SCR 시스템은 연료손실 없이 이론상 100%에 가깝게 NOx를 저감하는 가장 효과적인 기술로 환원반응으로 배기가스를 N₂와 H₂O로 배출하기 위해 환원제인 요소수를 분사해야한다. 하지만 엔진에서와는 달리 실제차량에서의 적용은 SCR 효율이 떨어지게 된다. 따라서 실제차량에서의 SCR 효율을 극대화하는 기술개발이 요구되고 있는 실정이다. 본 연구에서는, Post EURO-6 배기가스 규제에 대응하기 위한 디젤승용차량에서의 Urea-SCR의 NOx 저감 성능에 의한 저감효율의 극대화를 목적으로 실차용 Urea-SCR 시스템위한 기초자료로 제시하고자 한다. NOx reducing technique such as LNT, LNC , and selective catalytic reduction (SCR) have been developed and applied, especially on heavy-duty vehicles. However, it is expected that NOx reduction techniques will also be applied to diesel passenger vehicles. The urea-SCR system is receiving attention as the most effective NOx reduction technology without a fuel penalty. Thus, many advanced countries are developing this technology. The urea-SCR system sprays an aqueous urea solution that separates NOx into N₂ and H₂O, which are harmless and emitted into the atmosphere. The urea injected in front of the SCR catalyst should be changed to 100% NH₃, which is required for NOx reduction in the SCR system to maximize the reduction efficiency. The purpose of this study was to determine the basic data for the urea-SCR system to maximize the NOx reduction efficiency by understanding the NOX reduction characteristics in a real passenger vehicle to comply with the post EURO-6 emission regulation.
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.