http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Tran Dang Quoc,Kwangju Lee,Jong Tai Lee,Daewoo Nam 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
The direct injection natural gas fueled engine with lean combustion and high power is well known as the new generation of lean combustion system. Nowadays, the emission standards and fuel consumption are tighter than so the new generation is must be more expended lean limit. It is mean that the new generated engine will be operated with ultra lean mixture stably. Authors are used some methods to expand lean limit as follow: The rate of auxiliary intake fuel injection as a method to enhance the mixing duration, the lean limit is obtained λ = 1.53 but power is reduced rapidly. By the way the increased intake air is enhanced lean limit, it is due to supply energy and combustion rate are increased, although combustion temperature is decreased and power still increase. By the way the auxiliary intake fuel injection plus increase of intake air mass will be extended lean limit. This method may be achieved more ultra lean burn without low power and thermal efficiency. Until now, these results are not cleared. In this study as early step in using the ultra lean mixtures so that the analysis data is focused on lean limit and engine performance. The experimental results show that increased boost pressure at 1.3 bar will be extended lean burn region to λ = 1.49 and high power.
A Study on Expansion of Lean Limit for Heavy-Duty DI Engine with Compressed Natural Gas
Tran Dang Quoc,이광주,이종태 한국수소및신에너지학회 2011 한국수소 및 신에너지학회논문집 Vol.22 No.5
본 연구에서는 직접분사식 CNG기관의 희박한계를 보다 확장하여 고효율 및 저배기 공해를 실현시키고자 실린더 내에 고압의 천연가스를 직접분사함과 동시에 흡입과정 중 흡기관 내에 소량의저압천연가스를 보조분사하는 경우의 희박한계 확장 및 제반특성에 대해 검토하였다. 그 결과, 흡기보조분사가 없을 경우 희박한계가 λ = 1.4 까지였으나, 흡기보조분사율이 5~15%정도에서는 희박한계가 λ = 1.5 까지 확장되었다. 이는 흡기보조분사에 따른 혼합기의 혼합율 향상에 기인한 것으로 해석하였다. 연소기간은 줄어들었지만, 흡기보조분사의 효과는 주연소기간에서 조기연소기간보다 강하게 나타났다.
대형 직접분사식 CNG 기관의 압축비 변화에 따른 기관출력 및 배기특성
남대우(Daewoo Nam),Trandangquoc,이종태(Jongtai Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
In this study, variable compression ratio system(VCRS) was applied on the heavy-duty CNG engine and the characteristics of power and emission was investigated according to the increasing of compression ratio. As compression ratio increasing, the increasing of thermal efficiency in direct injection is three times higher than that in port injection. The emission of HC and CO in direct injection is reduced about 14.2%, 17.7% but NOx is increased because of increasing temperature in cylinder.