• Title/Summary/Keyword: 점화시기

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An effect of ignition timing on exhausting property of LPG Engine (점화시기가 LPG 엔진의 배기특성에 미치는 영향)

  • Han, Duck-Su;Jang, Young-Min;Chun, Bong-Jun;Kim, Sung-Joon
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.39-46
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    • 2006
  • As an automobile fuel, LPG has many environmental advantages compared to gasoline or diesel. However, current LPG engine which is provided with LPG fuel as gas form has lower power and worse fuel efficiency than gasoline engine. These problems of low power and bad fuel efficiency come from lower volumetric efficiency. Also there is a new rising problem of high failure ratio in an engine emission test. Although there are many factors which affect engine performance of exhaust gas emission, one believes that the fact that ECM of gasoline engine is used for LPG engine when retrofitting gasoline engine to LPG engine is one of the main problems, which lower engine power and emit more noxious gas due to wrong ignition timing. To solve these problems, one studied the effects of ignition timing on the exhaust gas to find out the optimum condition of ignition timing. The experimental results show that noxious exhaust gas is reduced and engine power is increased if the optimum control of ignition timing is applied in accordance to the revolution speed of engine.

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A Study on the Adaptive Control of Spark Timing Using Cylinder Pressure in SI Engine (전기점화기관에서 실린더압력을 이용한 점화시기 적응제어에 관한 연구)

  • 조한승;이종화;유재석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.3
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    • pp.122-129
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    • 1996
  • The spark timing is one of major parameters to the engine performance and emissions. The ECU controls the spark timing based on preset values, which are functions of load and speed, in most of today's automotive SI engine. In this system, the preset spark timing can be different from optimum value due to the deviations from mass production, aging effects and so on. In the present study, a control logic is investigated for real time adaptation of spark timing to optimal value. It has been found that crank angle of miximum cylinder pressure is one of the appropriate parameters to estimate the optimum spark timing throught experiment. It has also been observed for spark timing convergence by variation of engineering model factors. The simulation program including engineering model for cycle by cycle variation of combustion is developed for surveying spark timing control logic. It is also shown that simulation results reflect experiment outputs and reasonableness of spark timing control logic for crank angle of maximum cylinder pressure.

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A Study on Reduction of Exhaust Gas Temperature in Retrofitted LPG Fueled Engine Based Medium-Duty Diesel Engine (중형 디젤을 기초한 LPG엔진에서 배기가스온도 저감 연구)

  • 최경호;조웅래
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.2
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    • pp.63-68
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    • 2003
  • The purpose of this study was to investigate reduction of exhaust gas temperature in LPG conversion engine from diesel. A conventional diesel engine was modified to a LPG(Liquified Petroleum Gas) engine that diesel fuel injection pump was replaced by the LPG fuel system. The research was peformed with measurement of exhaust gas temperature by varying spark ignition timing, air-fuel ratio, compression ratio, EGR ratio and different compositions of butane and propane. The major conclusion of this work were followed. (i) Exhaust gas temperature was decreased and power was increased with the advanced spark ignition timing. (ii) Exhaust gas temperature was decreased with lean and rich air-fuel ratio. (iii)Exhaust gas temperature was decreased and power was increased with the higher compression ratio. (iv) Engine power and exhaust temperature were not influenced by varied butane/propane fuel compositions. (v) Finally, one of the important parameters in reduction of exhaust gas temperature is spark ignition timing among the parameters in this study.

An Experimental Analysis of the Effects of Water Vapor Partial Pressure in Inlet Air, Spark Advance and Fuel Type on the Flame Propagation in a Spark Ingnition Engine (흡기중의 수증기분압과 점화시기 및 연료 변화에 따른 스파크 점화기관의 화염 전파 특성 분석)

  • 이택헌;전광민
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.5
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    • pp.191-198
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    • 1998
  • In this study, the effects of water vapor in inlet air, spark advance and fuel type in the spark ignition engine were investigated through the experiments of combustion and flame arriving pattern analysis using ionization probe. The results of flame propagation experiment using ionization probe show that the flame which ignited from spark plug located at the center of the combustion chamber propagated faster in exhaust side than in intake side due to the mixture flow motion inducted into combustion chamber from intake tumble port at all conditions. And as the partial vapor pressure increased, the flame propagation became slower in all direction. Especially effects were greater for intake side than the exhaust side.

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Ignition Transition by Ignition Position and Time of Gaseous Oxygen/Kerosene Combustor (기체산소/케로신 연소기에서 점화 위치 및 시간에 따른 점화 과정 연구)

  • Song, Wooseok;Shin, Dongsoo;Son, Min;Koo, Jaye
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.4
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    • pp.85-90
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    • 2018
  • The objective of this paper is to observe effects of ignition position and time on ignition transition. A gaseous oxygen and liquid kerosene mixture is used as propellant with a shear-coaxial injector. In order to study the ignition delay time and combustion instability intensity, the pressure transducer was used. Sequences, excepting igniter operation time, were fixed to compare the ignition time only. Initial pressure peak and ignition delay time increased as the ignition time was delayed. Additionally, an unstable flame development zone was detected when the igniter was away from the injector.

Exhaust Gas Temperature and Combustion Stability Variation due to Changes in Spark and Exhaust Valve Timings (스파크 점화기관의 냉시동시 배기밸브 타이밍 및 점화시기 변화에 따른 배기가스 온도 및 연소안정성의 변화)

  • Kim Duksang;Park Youngjoon;Yang Changsuck;Cho Yong-Seok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.4
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    • pp.90-96
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    • 2005
  • The improvement of combustion stability is very important because it is closely related to the exhaust emission concentrations as well as the fuel consumption during the cold start of SI engine. In our previous studies, the spark and exhaust valve timings were retarded individually from the baseline case to increase the exhaust gas temperature far fast warmup of a close-coupled catalyst. In the study, it was found that combustion stability during cold start becomes worse when the valve timing is retarded from the baseline conditions. The spark and valve timings were simultaneously changed from the baseline conditions to find out the variation of combustion stability during cold start of an Sl engine. Through the study. retarded spark timing by $5^{\circ}$ CA helps improvement of $COV_{imep}$ by $2\%$ and $15^{\circ}C$ increase of exhaust temperature. Retarded exhaust valve timing makes the exhaust gas temperature increase by $30^{\circ}C$, but it also deteriorates the $COV_{imep}$ by $1\%$.

The Effect of Intake Air Temperature on Knock Characteristics in a Spark-Ignition Engine (흡입 공기 온도변화에 따른 스파크 점화기관의 노킹 특성 변화)

  • 정일영;전광민
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.1
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    • pp.22-31
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    • 1993
  • Spark-ignition engine knock is affected by engine operating conditions such as engine speed, spark timing and intake air temperature. In this study the effect of intake air temperature on knock characteristics was studied experimentally using a 4-cylinder carburetor spark-ignition engine. The cylinder pressure data at 2000rpm were taken for intake air temperature range of $30^{\circ}C$ to $80^{\circ}C$ with $10^{\circ}C$ interval. And 80 consecutive cycles were taken at each experimental condition. As the same spark timing, as the intake air temperature increased by $50^{\circ}C$, the mean knock intensity increased about 20kPa. This effect corresponds to that of spark timing advance of 3 crank angle degrees.

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An Experimental Study of the Effects of Water Vapor in Intake Air on Comvustion and knock Characteristics in a Spark Ignition Engine (흡기중 수증기 함량이 스파크 점화기관의 연소 및 노킹에 미치는 영향에 관한 실험적 연구)

  • 이택헌;전광민
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.205-212
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    • 1998
  • In this study, the effects of water vapor in inlet air on combustion efficiency, general performance, knock characteristics and emission gas concentration were investig- ated through the experiments of combustion and vibration analyses, emission gas analysis by changing water vapor quantity in inlet air with temperature and humidity auto control unit. With partial vapor pressure increase, the brake torque at wide open throttle status decreased and the average ignition delay angle increased, IMEP (indicated mean effective pressured using the integral and 3rd derivatives of filtered cylinder pressure as knock intensity, which matched well with the method of frequency power spectrum of block vibration signal. Water vapor in intake air had influence on the spark knock sensitivity. With the increase of water vapor content in intake air NOx emission was decreased and HC emission was increased.

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Analysis of Discharge Distribution according to Degradation in Insulator Layer of Ignition Coil (점화코일 절연층의 열화에 따른 방전분포 해석)

  • Kim, T.Y.;Shin, J.Y.;Park, H.D.;Kim, W.K.;Hong, J.W.
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2043-2045
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    • 2005
  • 현재 점화코일은 소형화 및 친환경성을 위해 에폭시 몰딩 절연층으로 변화되었다. 그러나 에폭시 몰딩으로 변환됨에 따라 점화코일 내부 절연층에 대한 절연진단 및 노화에 대한 정확한 진단의 어려움으로 적절한 교체시기를 예측하기 더욱 어려워졌다. 그로 인해 점화장치부분에 대한 예기치 못한 사고는 대형사고 유발을 초래할 수 있다. 이에 본 논문에서는 비파괴검사의 일종인 부분방전을 이용한 열화검출을 연구하기 위해 열화에 따른 위상각-방전전하량-방전빈도수의 분포 특성을 조사하였다. 또한 방전 발생의 분포가 동일 조건에서도 매우 불규칙성을 가지고 있으므로 데이터의 정량화를 위해 불규칙적인 통계처리를 위한 와이블 분포를 사용하여 기기의 고장시간예측을 조사하였다.

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Countermeasures to the Introduction of Low Caloric Gas Fuel for Natural Gas Engine (저열량 가스 적용에 따른 천연가스엔진의 대응 방안 연구)

  • Park, Cheol-Woong;Kim, Chang-gi;Oh, Se-Chul;Lee, Jang-Hee
    • Journal of the Korean Institute of Gas
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    • v.25 no.2
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    • pp.34-41
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    • 2021
  • In order to cope with the problems that may occur when the natural gas used in Korea becomes low in calories, the problems that may have to the domestic industrial gas equipment must be identified in advance, and based on this, countermeasures for efficient use of energy must be preceded. In this study, in order to solve the problem of deterioration of engine output performance and efficiency due to the introduction of low calorific gas when using a lean-burning natural gas engine that complies with the EURO-6 regulation, specific control plans and results based on the experiment are intended to be presented. In order to identify the improvement effect by the control variable represented by the ignition timing under the full load condition at the engine speed of 1,400 rpm and 550 Nm, 2,100 rpm, which is the engine speed at the rated operation condition, the thermal efficiency and exhaust gas characteristics were identified and optimized by changing the ignition timing for each gas fuel. In the case of pure methane, which shows the lowest value based on the torque under the full load condition, if the ignition timing is advanced by about 2 CAD from the reference ignition timing, the torque can be compensated without a large increase in NOx emission.