http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
가솔린 예혼합 압축 착화 엔진의 농후 한계에서 노킹 특성
염기태(Kitae Yeom),장진영(Jinyoung Jang),배충식(Choongsik Bae) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1
Variable valve timing is one of the attractive ways to control HCCI (homogeneous charge compression ignition) engine. Hot internal residual gas which can be controlled by VVT device, makes fuel is evaporated easily, and ignition timing is advanced. Regular gasoline was used as main fuel and DME (di-methyl ether) was used as ignition promoter in this research. HCCI engine operating range is limited by high combustion peak pressure and engine noise. High combustion pressure can damage the engine during operation, To avoid engine damage, the rich limits have to define using various methods. Peak combustion pressure, rate of cylinder pressure rise was considered to determine rich limit of engine operating range. Knock probability was correlated with the rate of cylinder pressure rise as well as the peak combustion pressure.
밸브 타이밍 변화에 대한 스파크 점화 엔진의 운전 및 배출가스 특성
염기태(Kitae Yeom),장진영(Jinyoung Jang),배충식(Choongsik Bae) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Variable valve timing (VVT) is the effective ways to improve peak power and part load fuel consumption of SI engines. VVT system is a relatively simple, low cost and easy application, therefore it is very attractive to be adopted in the newly manufactured engine. The objective of this work was to investigate the effects of intake and exhaust valve timings on engine operating parameters and exhaust emissions using a 4-cylinder in-line gasoline-fueled engine with VVT. Various Intake and exhaust valve timing data were measured and analyzed. Their correlations with each valve timing effect were also investigated in low and middle engine speed and load. The experimental results indicate that the pumping work, NOx emissions were reduced, while improvements in fuel economy and performance were achieved.
Top-Feed Type 인젝터의 LPG 액상분사 적용성
염기태(Kitae Yeom),박정서(Jungseo Park),장진영(Jinyoung Jang),문석수(Seoksu Moon),배충식(Choongsik Bae),박정남(Jeongnam Park),김성근(Sungkun Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The injection and spray characteristics of Top-feed type injector was investigated under liquid phase injection fueled with liquefied petroleum gas (LPG). Different pressures and temperatures of fuel injection system were tested to identify the injection characteristics after hot soaking. MIE-scattering technique was used for verification of successful liquid phase injection after hot soaking. In case of Bottom-feed type injector, the injection was accomplished at every experimental condition. In case of Top-feed type injector, when the pressure of LPG was over 12 bars, the injection was not executed. The effects of temperature of fuel on fuel injector were little. However, under the pressure were 12 bars, the liquid phase injection after hot soaking was accomplished.
예혼합 압축 착화 엔진에서 노킹 예측 및 배기 배출물 저감
염기태(Kitae Yeom),배충식(Choongsik Bae) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The knock characteristic and estimation in an engine were investigated under homogeneous charge compression ignition (HCCI) operation. Liquefied petroleum gas (LPG) and gasoline were used as fuels and injected at the intake port using port fuel injection equipment. Di-methyl ether (DME) was used as an ignition promoter and was injected directly into the cylinder during the intake stroke. A commercial variable valve timing device was used to control the volumetric efficiency and the amount of internal residual gas. Different intake valve timings and fuel injection amounts were tested to verify the knock characteristics of the HCCI engine. The ringing intensity (RI) was used to define the intensity of knock according to the operating conditions. The RI of the LPG HCCI engine was lower than that of the gasoline HCCI engine at every experimental condition. The indicated mean effective pressure (IMEP) dropped when the RI was over 0.5 ㎿/㎡ and the maximum combustion pressure was over 6.5 ㎫. There was no significant relationship between RI and fuel type. The RI can be predicted by the crank angle degree (CAD) at 50 CA. Carbon monoxide (CO) and hydrocarbon (HC) emissions were minimized at high RI conditions. The shortest burn duration under low RI was effective in achieving low HC and CO emissions.
LPG와 가솔린 예혼합 압축 착화 엔진의 배기가스 배출물 특성
염기태(Kitae Yeom),장진영(Jinyoung Jang),배충식(Choongsik Bae) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1
Variable valve timing is one of the attractive ways to control homogeneous charge compression ignition (HCCI) engine. Hot internal residual gas which is controlled by variable valve timing (VVT) device, makes fuel is evaporated easily, and ignition timing is advanced. Regular gasoline and liquefied petroleum gas were used as main fuel and di-methyl ether (DME) was used as ignition promoter in this research. HCCI engine operating range is limited by high combustion peak pressure and engine noise. High combustion pressure can damage the engine during operation. Operating range and exhaust emissions were compared liquefied petroleum gas (LPG) HCCI engine with gasoline HCCI engine. Operating range of LPG HCCI engine was wider than that of gasoline HCCI engine. And carbon dioxide (CO₂) emission of LPG HCCI engine was lower than that of gasoline HCCI engine. However, carbon oxide (CO) and hydro carbon (HC) emission of LPG HCCI engine were higher than that of gasoline HCCI engine.