• Title/Summary/Keyword: 예혼합압축착화엔진

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Using Two-Dimensional Chemiluminescence Images to Study Inhomogeneity in Mixture Gas in the Combustion Chamber for HCCI Combustion (이차원발광화상계측에 의한 예혼합압축자기착화연소의 연소실내 혼합기의 불균질성에 관한 연구)

  • Lim, Ock-Taeck;Iida, Norimasa
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.12
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    • pp.1043-1050
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    • 2010
  • Fuel stratification and thermal stratification occur in the HCCI combustion chamber on a microscopic scale. They affect the ignition and combustion processes. In this study, the effect of the inhomogeneity in the mixture gas on the HCCI combustion process was investigated. Two-dimensional chemiluminescence images were captured using a framing camera to evaluate the flame structure. DME was used as the test fuel. First, the effect of inhomogeneity in the fuel distribution in the premixture was investigated for the four-stroke optically accessible engine. Then, by comparing the combustion of the homogeneous mixture in the rapid compression machine, which does not contain any residual gas, with the combustion in the four-stroke engine, the effect of inhomogeneity in temperature due to the residual gas was analyzed. The results showed that a time lag appears spatially in combustion under inhomogeneous conditions in the four-stroke engine. The spatial variation in the combustion without the residual gas in the rapid compression machine is less than that in the combustion in the four-stroke engine.

A Study on the Spray and Combustion Characteristics of a HCCI Engine according to Injection Conditions using a Narrow Angle Injector (좁은 분사각을 갖는 인젝터를 이용한 예혼합 압축착화 엔진의 분사조건에 따른 분무 및 연소특성에 관한 연구)

  • Kim, Hyung-Min;Kim, Yung-Jin;Ryu, Jea-Duk;Lee, Ki-Hyung
    • Journal of ILASS-Korea
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    • v.11 no.3
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    • pp.161-167
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    • 2006
  • As the exhaustion of petroleum resources and air pollution problems are getting serious recently, there are growing interests in premixed diesel engines which have the potential of achieving a more homogeneous mixture near TDC compared to conventional diesel engines. Early studies have shown that the fuel injection frequency and spray angle affected the mixture formation and combustion in a HCCI(Homogeneous Charge Compression Ignition) engine. Therefore, the purpose of this study is to investigate the relationship between combustion and mixture formations by injection timing and frequency using a narrow angle injector, NADI (Narrow Angle Direct Injection). In this study, we found that the fuel injection timing and injection frequency affect the mixture formations and then affect combustion in the HCCI engine.

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Flame and Combustion Characteristics of D.I. HCCI Diesel Engine using a Visualization Engine (가시화 엔진을 이용한 직분식 예혼합 압축착화 디젤엔진의 화염 및 연소특성)

  • 권오영;류재덕;이기형;이창식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.6
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    • pp.100-107
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    • 2002
  • Combustion characteristics of diesel engine depends on mixture formation process during Ignition delay and premixed flame region. Fuel and air mixture formation has a great influence on the exhaust emission. Therefore, the present study focused on the combustion mechanism of Homogeneous Charge Compression Ignition (HCCI) engine. This study was carried out to investigate the combustion characteristics of direct injection type HCCI engine using a visualization engine. To investigate the combustion characteristics, we measured cylinder pressure and calculated heat release rate. In addition, we investigated the flame development process by using visualization engine system. From the experimental result of HCCI engine, we observed that cool flame was always appeared in HCCI combustion and magnitude of cool flame was proportional to magnitude of hot flame. And we also found that fuel injection timing is more effective to increase lean homogeneous combustion performance than intake air temperature. Since increasing the intake air temperature improved fuel vaporization before the fuel atomizes, we concluded that increasing the temperature has disadvantage fur homogeneous premixed combustion.

Analysis of Combustion Characteristics for a Homogeneous Charge Compression Ignition Engine with Load Condition (예혼합 압축착화 디젤엔진의 부하변동에 따른 연소특성 분석)

  • 장시웅;이기형;이창식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.1
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    • pp.17-23
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    • 2002
  • In order to reduce exhaust emissions from diesel engine under wide operating range, an experimental study based on a new concept of combustion called HCDC(Homogeneous Charge Diesel Combustion) was conducted. In this concept, most of the fuel is supplied as premixed homogeneous charge and the rest is directly injected into a cylinder to ignite. In this study we compared combustion characteristics of an HCDC engine with those of conventional diesel engines. At high premixed fuel ratio and high load range, it was observed that premixed combustion heat release rate was low and diffusion combustion duration was shorten. from this experiment, it was found that NOx is reduced by the lower maximum temperature and soot is reduced by rapid combustion during diffusion combustion phase.

Combustion and Emission Characteristics of Premixed Charge Compression Ignition Diesel Engine (예혼합 압축 착화 디젤 엔진의 연소 및 배기 특성)

  • Heo, Seong-Geun;Kim, Dac-Sik;Lee, Chang-Sik
    • 한국연소학회:학술대회논문집
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    • 2001.06a
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    • pp.187-192
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    • 2001
  • A homogeneous premixed charge compression ignition engine is experimentally investigated for the reduction of exhaust emissions in diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC and CO emissions were increased with the increase of premixed ratio. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.

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Combustion Characteristics of Premixed Charge Compression Ignition Diesel Engine with EGR System (EGR율에 따른 예혼합 압축 착화 디젤 엔진의 연소 특성)

  • 이창식;이기형;김대식;허성근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.66-72
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    • 2002
  • A premixed charge compression ignition engine is experimentally investigated for the reduction of NOx and smoke emissions from diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentrations of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC emission was increased with the increase of premixed ratio. Also, when EGR system was applied to the PCCI diesel engine, the effect of EGR rate on the combustion characteristics and the exhaust gas emissions was discussed.

Combustion Characteristics of Premixed Charge Compression Ignition Diesel Engine (예혼합 압축 착화 디젤 엔진의 연소 특성)

  • 이창식;이기형;김대식;장시웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.9-14
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    • 2002
  • A homogeneous premixed charge compression ignition engine has been experimentally studied far the reduction exhaust emissions of diesel engines. In this study, the gasoline fuel is injected into the intake manifold to from homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.