• Title/Summary/Keyword: ignition characteristics

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A Study on Ignitability and Heat Release Rate Characteristics of Rigid Polyurethane Foam (경질 폴리우레탄폼의 착화성 및 열방출특성 연구)

  • 공영건;이두형
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.117-123
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    • 2003
  • In this study; the ignition and heat release rate characteristics of rigid polyurethane foam were investigated in accordance with setchkin ignition tester and cone calorimeter which is using oxygen consumption principle. In the ignition temperature study; flash-ignition temperature was $383^{\circ}C$-$390^{\circ}C$, self-ignition temperature was$ 493^{\circ}C$∼495$^{\circ}C$. The self-ignition temperature of rigid polyurethane foam was about $100^{\circ}C$ higher than the flash-ignition temperature. In the cone calorimeter study, the time to ignition of rigid polyurethane foam was faster as the external heat flux increase. In the same heat flux level, the time to ignition was faster as the density of rigid polyurethane foam decrease. Also the heat release rate was the largest value at the heat flux of /$50 ㎾\m^2$ and had a tendency of increase as the heat flux level and density increase. In the standpoint of time to ignition and heat release rate, the fire performance of rigid polyurethane foam was influenced by the applied heat flux level and density and the flashover propensity classified by Petrella's proposal was high.

An Experimental Study on Combustion and Exhaust Emissions Characteristics in RCCI (Reactivity Controlled Compression Ignition) of Dual-Fuel (Diesel+Gasoline) (2중연료(디젤+가솔린)의 RCCI 연소 및 배기 특성에 관한 실험적 연구)

  • Sung, K.A.
    • Journal of ILASS-Korea
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    • v.16 no.1
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    • pp.51-57
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    • 2011
  • An experimental study was performed to explore characteristics of combustion and exhaust emissions in the compression ignition engine of RCCI (reactivity controlled compression ignition) using diesel-gasoline dual fuel. A dual-fuel reactivity controlled compression ignition concepts is demonstrated as a promising method to achieve high thermal efficiency and low emissions. For investigating combustion characteristics, engine experiments were performed in a light-duty diesel engine over a range of SOIs (start of injection) and gasoline percents. The experimental results showed that cases of diesel-gasoline dual fuel combustion is capable of operating over a middle range of engine loads with lower levels of NOx and soot, acceptable pressure rise rate, low ISFC (indicated specific fuel consumption), and high indicated thermal efficiency.

Ignitability and Combustion Characteristics of Lean Mixture by Multi-Point Ignition (희박혼합기에 대한 다점점화의 점화능력 및 연소특성)

  • ;;;Lee, Sang Joon;Han, Sung Bin;Lee, Jong Tai
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.10
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    • pp.2607-2616
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    • 1995
  • The influences of number of spark plug on ignitability, combustion characteristics and combustion promotion effect were examined to establish the design conception of spark ignition system for lean burn. Ignitability was increased remarkably by increasing of number of spark plug at combustion wall. Combustion duration was shortened and maximum combustion pressure was increased in accordance with increasing of spark plug number. Rate of overall combustion promotion considered of combustion duration and combustion pressure was 28% in two point ignition and 40% in four point ignition. It was verified that heat release, heat loss and combustion duration were affected by flame area, heat transfer area and maximum flame travel distance respectively.

Fuel Injection System on Combustion and Exhaust Emissions Characteristics in Compression Ignition Engines (압축착화 엔진에서 디젤-가솔린 Dual Fuel이 연소 및 배기 특성에 미치는 영향)

  • Kwon, Seok-Joo;Cha, June-Pyo;Sung, Ki-An;Park, Sung-Wook
    • Journal of the Korean Society of Combustion
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    • v.16 no.1
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    • pp.52-57
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    • 2011
  • The present study describes the characteristics of combustion and exhaust emissions in compression ignition engines using diesel-gasoline dual fuel. For investigating combustion characteristics, diesel fuel was injected directly in a single-cylinder compression ignition engine with a common-rail injection system and gasoline fuel was injected into a premixed chamber installed in an intake port. In order to investigate exhaust emission characteristics, exhaust gas was measured by emission analyzer and smoke meter. The experimental results showed that cases of diesel-gasoline dual fuel combustion exhibited extended ignition delay and reduced peak combustion pressure compared to those of directly injected diesel fuel cases. Furthermore, premixed gasoline-air mixture reduced NOx emissions due to low peak of rate of heat release(ROHR).

An Experimental Study on the Two Stage Ignition of Cool Flame and Hot Flame in HCCI Engine According to Fuel Composition (연료조성에 따른 HCCI 엔진의 냉염 및 열염의 2단연소 특성에 관한 실험적 연구)

  • 이기형;김형민;류재덕;이창식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.17-24
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    • 2004
  • As the environmental pollution becomes serious global problem, the regulation of emission exhausted from automobiles is strengthened. Therefore, it is very important to know how to reduce the NOx and PM simultaneously in diesel engines, which has lot of merits such as high thermal efficiency, low fuel consumption and durability. By this reason, the new concept called as Homogeneous Charge Compression Ignition(HCCI) engines are spotlighted because this concept reduced NOx and P.M. simultaneously. However, it is well known that HCCI engines increased HC and CO. Thus, the investigation of combustion characteristics which consists cool and hot flames for HCCI engines were needed to obtain the optimal combustion condition. In this study, combustion characteristics for direct injection type HCCI engine such as quantity of cool flame and hot flame, ignition timing and ignition delay were investigated to clarify the effects of these parameters on performance. The results revealed that diesel combustion showed the two-stage ignition of cool flame and hot flame, the rate of cool flame increase and hot flame decrease with increasing intake air temperature. On the other hand, the gasoline combustion is the single-stage ignition and ignition timing is near the TDC. In addition mixed fuel combustion showed different phenomenon, which depends on the ratio of gasoline component. Ignition timing of mixed fuel is retarded near the TDC and the ignition delay is increased according to ratio of gasoline.

An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine According to Variation of the Injection Timing (분사시기의 변화에 따른 제어자발화 가솔린기관의 배기특성)

  • Kim, H.S.
    • Journal of Power System Engineering
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    • v.8 no.3
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    • pp.5-10
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    • 2004
  • This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. In order to keep a homogeneous air-fuel mixing, the fuel injector is water-cooled by a specially designed coolant passage. Investigated are the engine emission characteristics under the wide range of operating conditions such as 40 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, $150\;to\;180^{\circ}C$ in the inlet-air temperature, and $80^{\circ}$ BTDC to $20^{\circ}$ ATDC in the injection timing. A controlled auto-ignition gasoline engine which has the ultra lean-burn with self-ignition of gasoline fuel can be achieved by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engine.

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An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine according to Variation of the Air-Fuel Ratio (공기연료비의 변화에 따른 제어자발화 가솔린기관의 배기 특성)

  • Kim, Hong-Wung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.2
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    • pp.79-85
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    • 2004
  • This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. Investigated are the engine emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine can be achieved the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engines.

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Performance Characteristics of a Controlled Auto-Ignition Gasoline Engine (제어자발화 가솔린기관의 성능 특성)

  • Kim, Hong-Sung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.4 no.1
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    • pp.56-62
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    • 2005
  • In this study, A controlled auto-ignition (CAI) single cylinder gasoline engine is considered, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. Investigated are the engine performance characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine which has the super ultra lean-burn with self-ignition of gasoline fuel can be achieved by heating inlet air.

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A Study on Medium Voltage Power Supply with Enhanced Ignition Characteristics for Plasma Torch

  • Jung, Kyung-Sub;Suh, Yong-Sug
    • Proceedings of the KIPE Conference
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    • 2010.07a
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    • pp.242-243
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    • 2010
  • This paper investigates a power supply of medium voltage with enhanced ignition characteristics for plasma torch. Series resonant half-bridge topology is presented to be a suitable ignition circuitry. The ignition circuitry is integrated into the main power conversion system of a multi-phase staggered three-level dc-dc converter with a diode front-end rectifier. The plasma torch rated for 3MW, 2kA and having the physical size of 1m long is selected to be a high enthalpy source in waste disposal system. The steady-state and transient operations of plasma torch are simulated. The parameters of Cassie-Mary arc model are calculated based on 3D magneto-hydrodynamic simulations. Circuit simulation waveform shows that the ripple of arc current can be maintained within ${\pm}10%$ of its rated value under the existence of load disturbance. This power conversion configuration provides high enough ignition voltage around 5KA during ignition phase and high arc stability under the existence of arc disturbance noise resulting in a high-performance plasma torch system.

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An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine (제어자발화 가솔린기관의 배기 특성)

  • Kim, H.S.
    • Journal of Power System Engineering
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    • v.13 no.3
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    • pp.5-10
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    • 2009
  • This work deals with a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. The fuel is injected indirectly into electrically heated inlet air flow. In order to keep a homogeneous air-fuel mixing, the fuel injector is cooled by the water of a specially designed coolant passage. The engine emission characteristics were investigated under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet air temperature. The ultra lean-burn can be achieved by the auto-ignition of gasoline fuel due to the heated inlet air in the compression ignition gasoline engine. It is confirmed that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxide can be significantly reduced by CAI combustion compared with the combustion of a conventional spark ignition engine.

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