• 제목/요약/키워드: 직접분사식

검색결과 239건 처리시간 0.024초

연소제어인자의 변화에 따른 직접분사식 초희박 LPG엔진의 연소특성 연구 (Study of Combustion Characteristics with Variations of Combustion Parameter in Ultra-Lean LPG Direct Injection Engine)

  • 박윤서;박철웅;오승묵;김태영;최영;이용규
    • 대한기계학회논문집B
    • /
    • 제37권6호
    • /
    • pp.607-614
    • /
    • 2013
  • 오늘날 전 세계의 자동차 회사들은 연비를 향상시키고 배기가스를 저감시키기 위해 다양한 기술을 개발하고 있다. 그 중 직접분사식 초희박 연소기술은 연료제어의 정확도를 향상시켜 연소 효율을 극대화하고 초희박 연소를 통해 연비를 향상 시킬 수 있는 차세대 기술로 평가받고 있다. 따라서 기존 가스엔진에 초희박 직접분사 기술을 적용한 초희박 LPG 직접분사 엔진을 개발하기 위해 $2{\ell}$ 급 MPI 엔진을 베이스 엔진으로 실린더 헤드를 재설계하였다. 재설계된 헤드는 초희박 연소를 구현하기 위해 인젝터와 점화플러그가 헤드 중앙에 장착되는 분무유도방식 연소시스템을 적용하였다. 연료 분사 압력별 연료 분사 시기와 점화 시기의 변경을 통해 연료 소비율과 연소 안정성을 측정하였으며 이를 통해 최적연료 분사시기와 점화시기를 선정하였다.

LPG 연료를 이용한 직접분사식 스파크점화 엔진의 특성에 관한 연구 (A Study on the Characteristics of Direct Injection Spark Ignition Engine using a Liquefied Petroleum Gas Fuel)

  • 이민호;정동수;차경옥
    • 한국자동차공학회논문집
    • /
    • 제13권2호
    • /
    • pp.44-51
    • /
    • 2005
  • According to the increasing concern on the global environment, the $CO_2$ regulation has been discussed including automobile emission regulation. In order to cope with this rapid changing circumstances, the development of an ultra low emission and super fuel economy automobile is essential. Direct injection LPG engine is the one of the possible future engine to maximize the engine efficiency. This experimental study for the development of direct injection LPG engine technology is promoted with two parts; spray characteristics of high pressure swirl injector, and performance characteristics of direct injection LPG engine. Engine characteristics according to the fuel was analyzed in order to establish stratified combustion technology for LPG engine by using the DISI engine. In the engine experiment, control system was manufactured for gasoline and LPG fuel. The engine was modified 2,000 cc GDI engine (fuel supply device, fuel injection device). Through this experiment, engine operating condition, engine speed and spark timing (MBT), fuel injection position, and fuel rate were investigated.

직접분사식 가솔린 엔진에서 분사시기와 흡입유동이 실린더 내 연료의 거동에 미치는 영향 (Effects of Injection Timing and Intake Flow on In-Cylinder Fuel Behavior in a GDI Engine)

  • 이정훈;강정중;김덕줄
    • 한국자동차공학회논문집
    • /
    • 제11권6호
    • /
    • pp.7-13
    • /
    • 2003
  • The purpose of this study is to investigate the effect of the in-cylinder flows and different injection timings on fuel behavior in the cylinder of a GDI engine. Three different flows types induced by using masked port, unmasked port, and port deactivation were tumble, swirl&tumble, and high swirl respectively. LIEF technique was applied to investigate the mixture formation and fuel distribution at ignition time in the transparent engine with optical access through the piston top and upper part of cylinder liner. Injection timings of 180,90, and 60 degrees before TDC were examined. It was found that tumble flow was more effective on the homogeneous mixture formation than other flow and swirl flow transported more fuel vapor to the exhaust side at early injection mode, and swirl and swirl & tumble flow made fuel vapor concentrate around the cylinder center at late injection mode.

직접분사식 가솔린 선회 분사기에서의 내부 유동특성에 관한 수치 해석 (A numerical study on the characteristics of internal flows in a gasoline direct swirl injector)

  • 배수호;문수연;이충원
    • 한국분무공학회지
    • /
    • 제6권2호
    • /
    • pp.9-15
    • /
    • 2001
  • The internal flow characteristics of a gasoline direct injector have been studied to improve fuel economy and reduce exhaust emissions. Computational Fluid Dynamics (CFD) is used to examine the internal flow of the GDI with the purpose of designing the optimum geometry of the injector. This study tests orifice length, cone angle, swirl angle, orifice diameter and needle lift. The results show that optimum sizes of the orifice length, cone angle, swirl angle, orifice diameter and needle lift are 0.8mm, $140^{\circ},\;120^{\circ},\;80mm\;and\;70{\mu}m$, respectively. The size of the lift does not affect the formation of the air core signficantly near the tip of the needle compared to the ball-type needle. The vena contracta phenomenon near the orifice inlet can be released by smoothing the edge.

  • PDF

전자제어식 직접분사 디젤 엔진 연소실내의 분무연소 특성에 관한 연구 (A study on the spray combustion characteristics in a cylinder of a D.I.diesel engine with the electronically controlled injector)

  • 정재우;김성중;이기형;선우명호
    • 한국자동차공학회논문집
    • /
    • 제8권2호
    • /
    • pp.50-56
    • /
    • 2000
  • It is well known that the combustion phenomenon of diesel engine is an unsteady turbulent diffusion combustion. Therefore, the combustion performance of diesel engine is related to a complex phenomenon which involves the various factors of combustion, such as a injection pressure, injection timing, injection rate, and operation conditions of engine. In this study, the spray and the flame development processes in a single cylinder D.I. diesel visualization engine which uses the electronically controlled injection system were visualized to interpret the complicated combustion phenomenon by using high speed CCD camera. In addition, the cylinder pressure and heat release rate were also obtained in order to analyze the diesel combustion characteristics under several engine conditions.

  • PDF

직접분사식 디젤기관에서 바이오디젤 연료의 연소특성 (The Combustion Characteristics of Biodiesel Fuel as an Alternative Fuel for D.I. Diesel Engine)

  • 장세호;서정주
    • 동력기계공학회지
    • /
    • 제12권2호
    • /
    • pp.12-17
    • /
    • 2008
  • Biodiesel fuel(BDF) which is easily produced from vegetable oils such as soybean oil and rice bran oil can be effectively used as an alternative fuel in diesel engine. But biodiesel fuel can affect the performance and emissions in diesel engine because it has different chemical and physical properties from diesel fuel. To investigate the combustion characteristics of biodiesel fuel as an alternative fuel for D.I. diesel engine, the experiments were carried out at the three-cylinder, four stroke D.I. diesel engine with T/C. Experimental parameters adopted a conventional diesel fuel and a blend of biodiesel fuel derived from soybean. As a result of experiments in a test engine, BSFC with blend of BDF resulted in higher than with diesel fuel. The ignition delay decreased with blend of BDF than with diesel fuel.

  • PDF

LPG를 보조적으로 사용한 직접분사식 디젤기관의 성능에 관한 연구 (The Effect of Auxiliary use LPG on the Performance of a D.I Diesel Engine)

  • 방중철
    • 한국자동차공학회논문집
    • /
    • 제13권3호
    • /
    • pp.138-145
    • /
    • 2005
  • Recently, the tightening of an available crude oil supplies has resulted in the development of intense consciousness for saving fuels. At the same time, some research programs have been launched to secure substitute energy sources for petroleum-derived fuels, and to reduce unhealthy products, such as CO, HC, NOx and smoke. To keep up with these trends in society, the regulation affecting diesel smoke may be greatly strengthened in a short time. In not too distant future, LPG and LNG are the most hopeful substitute fuels for automobile and truck uses. This paper discusses how to use such gaseous fuels in a diesel engine, and how much methods for introducing these fuels affect the engine performance.

직접분사식 디젤기관에서 바이오디젤 연료의 연소특성(2) (Combustion Characteristics of Biodiesel Fuel as an Alternative Fuel for a D.I. Diesel Engine(2))

  • 장세호
    • 동력기계공학회지
    • /
    • 제13권6호
    • /
    • pp.51-56
    • /
    • 2009
  • Recently, lots of researchers have been attracted to develop various alternative fuels in diesel engine. The use of biodiesel fuel(BDF) is an effective way of substituting diesel fuel in the long run. But biodiesel fuel can affect the performance and emissions in diesel engine because it has different chemical and physical properties from diesel fuel. In this study, to investigate the combustion characteristics of biodiesel fuel as an alternative fuel for D.I. diesel engine, experiments were carried out at the three-cylinder, four stroke D.I. diesel engine with T/C. As a result, shorter ignition delays were observed for the biodiesel blend cases relative to the diesel oil. The pick value of premixed combustion for the rate of heat release is increased with decreasing C.F.W. temperature.

  • PDF

알코올을 보조적으로 사용한 직접분사식 디젤기관의 성능에 관한 고찰 (Some Considerations for Performance of D.I. Diesel Engine Using Auxiliary Fuel Such as Alcohol)

  • 이형곤;방중철
    • 한국자동차공학회논문집
    • /
    • 제10권3호
    • /
    • pp.28-35
    • /
    • 2002
  • The objective of this paper is to quantitatively investigate the effects of alcohol mixture on the combustion improvement of main fuel in supplying alcohol to direct injection diesel engine by auxiliary injection method and blend method. If alcohol is supplied, engine performance greatly improves in high load range. In case of supplying ethanol, BSFC improves, the emission of smoke and NO decreases by delaying main fuel injection timing 5$\^{C}$A. The maximum delivery quantity of alcohol is limited to approximately 50% of total fuel delivery due to misfire and knocking. The limit quantity of main fuel injection that does not accompany misfire and the deterioration of BSFC was approximately 15∼18.5mg/st.

직접분사식 가솔린엔진의 연소실 형상이 성층화 연소에 미치는 영향 (Effects of Combustion Chamber Shape on the Stratified Combustion of a GDI Engine)

  • 송재원;김미로;조한승;여진구;조남효
    • 한국자동차공학회논문집
    • /
    • 제10권1호
    • /
    • pp.67-75
    • /
    • 2002
  • A study to investigate the influence of combustion chamber shape, especially piston top face configuration, on the combustion stability is presented with CFD analysis and single cylinder GDI engine test. Initial configuration of the piston bowl was designed with CFD analysis and further parametric studies of the design factors on the piston top face were carried out through the single cylinder GDI engine test. It was found that both the geometry of piston top face and the compression ratio have great influences on the combustion stability. Of interest is that the design factors of the GDI piston to prevent mixture diffusion out of the piston bowl have important roles for the stable combustion at the stratified mixture condition. Also the relationship between spray impingement and flow pattern in a GDI piston bowl should be considered to design an optimal bowl configuration for stable stratified combustion.