• 제목/요약/키워드: DI engine

검색결과 211건 처리시간 0.021초

Study of Combustion and Emission Characteristics for DI Diesel Engine with a Swirl-Chamber

  • Liu, Yu;Chung, S.S.
    • 한국분무공학회지
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    • 제15권3호
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    • pp.131-139
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    • 2010
  • Gas motion within the engine cylinder is one of the major factors controlling the fuel-air mixing and combustion processes in diesel engines. In this paper, a special swirl-chamber is designed and applied to a DI (direct injection) diesel engine to generate a strong swirl motion thus enhancing gas motion. Compression, combustion and expansion strokes of this DI diesel engine with the swirl-chamber have been simulated by CFD software. The simulation model was first validated through comparisons with experimental data and then applied to do the simulation of the spray and combustion process. The velocity and temperature field inside the cylinder showed the influences of the strong swirl motion to spray and combustion process in detail. Cylinder pressure, average temperature, heat release rate, total amount of heat release, indicated thermal efficiency, indicated fuel consumption rate and emissions of this DI diesel engine with swirl-chamber have been compared with that of the DI diesel engine with $\omega$-chamber. The conclusions show that the engine with swirlchamber has the characteristics of fast mixture formulation and quick diffusive combustion; its soot emission is 3 times less than that of a $\omega$-chamber engine; its NO emission is 3 times more than that of $\omega$-chamber engine. The results show that the DI diesel engine with the swirl-chamber has the potential to reduce emissions.

EFFECT OF DI-TERTIARY-BUTYL PEROXIDE ON IGNITION PERFORMANCE IN A COMPRESSION IGNITION NATURAL GAS ENGINE

  • Li, F.C.;Zheng, Q.P.;Zhang, H.M.
    • International Journal of Automotive Technology
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    • 제8권4호
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    • pp.413-419
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    • 2007
  • Experimental study of additives on the ignition performance of a compression ignition natural gas engine is introduced, followed by results of a simulation of its working mechanism. From the experimental results, it is understood that engine ignition performance can be improved when a certain amount of Di-tertiary-butyl peroxide additive is added. If the mass fraction of Di-tertiary-butyl peroxide additive reaches as high as 14.2%, engine ignition can be realized at ambient temperatures with a glow plug temperature of about $750^{\circ}C$. From the simulation results, we verify that the Di-tertiary-butyl peroxide additive, by cracking its radicals at lower temperature, can accelerate reaction rate. Therefore, the additive is able to improve the ignition performance of natural gas significantly.

직분식 디젤엔진에서 엔진 매개변수들이 NO 및 soot 배출에 미치는 영향에 대한 수치해석 연구 (Parametric Study for Reducing NO and Soot Emissions in a DI Diesel Engine by Using Engine Cycle Simulation)

  • 함윤영;전광민
    • 한국자동차공학회논문집
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    • 제10권5호
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    • pp.35-44
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    • 2002
  • Engine cycle simulation using a two-zone model was performed to investigate the effect of the engine parameters on NO and soot emissions in a DI diesel engine. The present model was validated against measurements in terms of cylinder pressure, BMEP, NO emission data with a 2902cc turbocharger/intercooler DI diesel engine. Calculations were made for a wide range of the engine parameters, such as injection timing, ignition delay, Intake air pressure, inlet air temperature, compression ratio, EGR. This parametric study indicated that NO and soot emissions were effectively decreased by increasing intake air pressure, decreasing inlet air temperature and increasing compression ratio. By retarding injection timing, increasing ignition delay and applying EGR. NO emission was effectively reduced, but the soot emission was increased.

직분식 디젤기관의 메탄올 흡기분사에 의한 기관성능과 배기배출물에 관한 연구 (A Study on the Engine Performance and Exhaust Emission with Intake Port Methanol Injection in a DI Diesel Engine)

  • 김명수;라진홍;안수길
    • 수산해양기술연구
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    • 제36권3호
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    • pp.249-256
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    • 2000
  • In order to investigate the effectiveness of methanol, which has high latent heat of evaporation and oxygen contents, for DI diesel engine performance and exhaust emission, the methanol was injected at the suction port of DI diesel engine. The injector used for test was conventional gasoline engine injector and controlled the quantity of methanol per cycle by the power supply controller which designed specially for injector. The results shown that the maximum pressure point was delayed, the value of maximum pressure was decreased, and the concentrations of both NOx and Soot were decreased, as the methanol injection quantity increased, and also the thermal efficiency of engine injected methanol under the high load condition was similar to no methanol injection but under the medium load condition was decreased within the experimental conditions.

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균일 혼합기를 이용한 이론 공연비 직접분사 가솔린 엔진 개발에 관한 실험적 연구 (A Study on the Development of Stoichiometric Direct Injection Gasoline Engine by Homogeneous Charge)

  • 이내현;유철호;최규훈
    • 한국자동차공학회논문집
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    • 제6권2호
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    • pp.32-42
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    • 1998
  • Lean burn gasoline engine is recognized as a promising way to meet better fuel economy. Lean burn engine is classified into port injection and direct injection(DI), DI is more active technique for improving fuel economy with ultra-lean operation, Nowadays, port injected lean burn engine has been produced by many Japan maker. Also, DI engine is also possible for production owing to improvement in control technique of spray, flow air fuel ratio. DI engine uses either homogeneous stoichiometric mixture or stratified mixture by controlling injection timing to be early or late respectively. HM(homogeneous mixture) is worse than SM(stratified mixture) in view of ultra-lean operation in partical load and Nox reducion by using EGR control. But, HM has advanteges in cold starting and emission reduction during transient operation, This paper describes experimental variables and bench test results of HM GDI engine.

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소형 DI 디젤 기관의 연소 모델링에 관한 연구 (A Study on the Modelling of Combustion in a Small DI Diesel Engine)

  • 고대권;김경현;장세호;안수길
    • 동력기계공학회지
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    • 제2권2호
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    • pp.20-26
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    • 1998
  • Heat release data were obtained by analysis of cylinder diagrams from a test engine, naturally-aspirated small-size four-stroke DI diesel engine. These data were used to decide empirical coefficients of Whitehouse-Way's model, single zone combustion model. Finally, the comparison of calculated with experimental results was performed, and the accuracy of calculated versus experimental data of the model in predicting engine heat release and cylinder pressure was demonstrated.

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엔진 사이클 시뮬레이션에 의한 직분식 디젤기관의 NO 배출물에 미치는 흡기충전 조건의 영향에 관한 연구 (A Study on Effect of Intake Charging Conditions upon NO Emissions in a DI Diesel Engine Using Engine Cycle Simulation)

  • 함윤영
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권6호
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    • pp.679-687
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    • 2002
  • In this study, a cycle simulation using a two-zone model is carried out to investigate the effect of intake charging conditions such as oxygen concentration, temperature and pressure on NO emissions in a DI diesel engine. The model is validated against measurements in terms of cylinder pressure, torque, BSFC and NOx emissions with 2902 cc DI diesel engine. Calculated results can be summarized as follows. The oxygen concentration in the intake charge is decreased with increasing of EGR rate and equivalence ratio. As the intake oxygen concentration is reduced, the combustion pressure and the burned gas temperature decrease and, as a result, NO formation decreases. Also, the results show that as the intake pressure increases and the intake temperature decreases, NO emissions are effectively reduced.

직접분사식 디젤기관에서 바이오디젤 사용과 연료분사시기 변화에 따른 기관성능 특성 (The Characteristics on the Engine Performance for Variation of Fuel Injection Timing in DI Diesel Engine Using Biodiesel Fuel)

  • 장세호
    • 동력기계공학회지
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    • 제16권3호
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    • pp.16-21
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    • 2012
  • Biodiesel is technically competitive with or offers technical advantages over conventional petroleum diesel fuel. Biodiesel is an environmentally friendly alternative liquid fuel that can be used in any diesel engine without modification. In this study, to investigate the effect of fuel injection timing on the characteristics of performance with DBF in DI diesel engine. The engine was operated at five different fuel injection timings from BTDC $6^{\circ}$ to $14^{\circ}$ at $2^{\circ}$ intervals and four loads at engine speed of 1800rpm. As a result of experiments in a test engine, maximum cylinder pressure is increased with leading fuel injection timing. Specific fuel oil consumption is indicated the least value at BTDC $14^{\circ}$ of fuel injection timing.

순수 DME의 직접분사식 디젤기관의 성능 및 배기가스 특성 (Engine Performance and Exhaust Emissions Characteristics of DI Diesel Engine Operated with Neat Dimethyl Ether)

  • 표영덕;이영재;김강출;김문헌
    • 대한기계학회논문집B
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    • 제27권5호
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    • pp.589-595
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    • 2003
  • DME(Dimethyl ether) is an oxygenated fuel with a octane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. In the present study, engine performance and exhaust emissions were investigated with a conventional DI diesel engine which has a jerk type injection pump. Test results showed that the power with DME were almost same as that of pure diesel oil, and the brake thermal efficiency increased a little. Also, smoke index from DME engine showed nearly zero level, but NO$_{x}$ was increased compare to diesel oil.

2단 분사 방식을 적용한 디젤 DI-HCCI 연소특성에 관한 연구 (A Study on the Diesel DI-HCCI Combustion Characteristics using 2-stage Injection Method)

  • 정재우;강정호;김병수;강우;김현철
    • 한국자동차공학회논문집
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    • 제12권6호
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    • pp.66-73
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    • 2004
  • In this study, combustion characteristics and various performances of a Diesel fuel DI-HCCI engine using 2-stage injection method were investigated. From these researches, application ability of 2-stage injection strategy to a DI-HCCI engine was confirmed and improvement methods of performances were considered. As the results, Using 2-stage injection method, without change of engine specifications and loss of IMEP, exhaust of NOx and Smoke emissions could be reduced to about 1/3 (at 1400rpm, IMEP 6bar) compared to conventional Diesel combustion.