• Title/Summary/Keyword: 점화시기

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A Impact Study on Combustion Characteristics of the Engine by Changing the Gasoline Properties (휘발유 물성변화가 엔진의 연소특성에 미치는 영향 연구)

  • Noh, Kyeong-ha;Im, Sang-bin;Lee, Min-ho;Kim, Ki-ho;Ha, Jong-han
    • Journal of Energy Engineering
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    • v.24 no.4
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    • pp.166-174
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    • 2015
  • This study examined combustion characteristics by selecting the fuel which have a different physical properties compared to gasoline in order to examine the effects of vehicle performance and environment depending on the physical properties. The experiment examined the combustion characteristic in the optimum ignition timing according to the physical properties change and the lean burn by performing control about ignition timing and air-fuel ratio for each fuel, and it was also evaluated the exhaust gas according to the experiment. We used a single-cylinder engine for the experiment, and tested for gasoline properties change by selecting a fake fuel that beyond the fuel quality standards in 석대법. As a result, in the case of the selected fuel showed a difference in Octane and distillation characteristics, vapor pressure and it was also found to unstable combustion, and leads to a large amount of harmful exhaust gas.

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

  • Park, Yun Seo;Park, Cheol Woong;Oh, Seung Mook;Kim, Tae Young;Choi, Young;Lee, Yong Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.6
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    • pp.607-614
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    • 2013
  • Nowadays, automotive manufacturers have developed various technologies to improve fuel economy and reduce harmful emissions. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of fuel and ignition. This study aims to investigate the development of a spray-guided-type lean-burn LPG direct injection engine through the redesign of the combustion system. This engine uses a central-injection-type cylinder head in which the injector is installed adjacent to the spark plug. Fuel consumption and combustion stability were estimated depending on the ignition timing and injection timing at various air-fuel ratios. The optimal injection timing and ignition timing were based on the best fuel consumption and combustion stability.

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;Son, Min;Shin, Dongsoo;Koo, Jaye
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.814-819
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    • 2017
  • The objective of this paper is to observe effects of an ignition position and time on the ignition transition. A gaseous oxygen and liquid kerosene are used for propellants with the shear-coaxial injector. In order to study the ignition delay time and combustion instability intensity, the pressure transducer was used. The ignition position was changed with the injector spacer. Sequences except the 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. Also, the unstable flame development zone was detected as the igniter was away from the injector.

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A study on the effect of Octane-Number on combustion characteristics and vehicle performance (옥탄가 차이가 연소특성 및 차량 성능에 미치는 영향 연구)

  • Noh, Kyeong-ha;Kim, Jung-hwan;Lee, Min-ho;Kim, Ki-ho
    • Journal of Energy Engineering
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    • v.25 no.3
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    • pp.41-50
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    • 2016
  • This study examined the combustion characteristics and emissions, fuel economy, acceleration by selecting the two fuel with octane number difference to investigate the effect on the combustion characteristics and performance of the vehicle according to the octane number. First, a single-cylinder engine was used for the combustion characteristic experiment, Of the fuel, which is distributed on the market by the selection of two different octane fuel it is performed experiments. Single cylinder experiment examined the combustion characteristics that appear when you gradually advancing the ignition timing by the ignition timing and air-fuel ratio control for each fuel and through an output, emissions, pressure, hence examined the correlation between by octane number. In addition through the actual vehicle compared the changes in the fuel octane number difference, through acceleration tests examined the impact of the octane number requirements for high-performance segment. As a result, fuel of high octane number in accordance with the ignition timing the advancing showed a slightly stable combustion characteristics, a slight increase occurred in the acceleration test and power. However, both fuel does not significantly differ from the current mode, simulating the urban and highway fuel efficiency. Therefore, the operating conditions of the vehicle currently being sold on the Effects of high-octane fuel. fuel efficiency was found insufficient.

The Prediction of Volumetric Efficiency Considering Gas Exchange Process in Spark Ignition Engine (전기점화기관에서 흡배기과정을 고려한 체적효율의 예측 및 실험)

  • Soh, S. G.
    • Journal of the korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.77-85
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    • 1987
  • 본 논문은 단기통 4사이클 전기점화기관에서 가스교환 과정이 체적효율에 미치는 영향에 대하여 연구한 것이다. 가스교환 과정의 수학적 모델을 설정하고 수치해석을 수행한 결과 체적효율은 가스교환과정과 관련되는 밸브 개폐시기(1,2)보다는 흡배기관의 압력에 의하여 더 큰 영향을 받는 다는 것을 알 수 있었다. 실험에 있어서는 각각 밸브 개폐시기가 다른 3종류의 캠을 사용하였 으며 수치 해석결과와 실험결고가 비교적 잘 일치하였다.

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A Study on the Application of Indolene -MPHA for Automotive Alternative Fuel (II) - (자동차 대체연료로서의 Indolene-MPHA의 적용에 관한 연구(II) - Indolene-MPHA가 엔진성능에 미치는 영향 -)

  • 이민호;오율권;차경옥
    • Journal of Energy Engineering
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    • v.12 no.3
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    • pp.190-196
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    • 2003
  • A study of the performance effect of Indolene-Methanol Plus High Alcolhols (MPHA) has been completed. The study invested the measurement of performance parameters. The performance parameters measured are minimum advance for best torque (MBT) spark timing, power output and thermal efficiency. The alcohol concentration was varied from 0 to 100 percent by volume in clear Indolene. The performance parameters were measured using a single cylinder spark ignition engine at different compression ratios. The results of the performance measurements indicated that Indolene-MPHA blends have a higher MBT spark advance, similar power output and lower thermal efficiencies than Indolene-Methanol blends.

A study on performance improvement of natural gas fueled engine (천연가스 기관의 성능 향상에 관한 연구)

  • 정동수;정진도;서승우;최교남
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.1
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    • pp.175-179
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    • 1992
  • Generally speaking, natural gas possesses several characteristics that make it desirable as an engine fuel : for example (1) lower production cost, (2) abundant commodity and (3) cleaner energy source than gasoline. Due to the physical characteristics of natural gas, the volumetric efficiency and flame speed of a natural gas engine are lower than those of a gasoline engine, which results in a power loss of 10-20% when compared to a convensional gasoline engine. This paper describes the results of a research to improve the performance of a natural gas engine through the modification and controls of air/fuel ratio, spark timing advance and supercharging effect by forced air supply method.

HMC 엔진의 전자제어 시스템 소개

  • 장익순;이재곤
    • Journal of the KSME
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    • v.32 no.10
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    • pp.876-882
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    • 1992
  • 여기에서는 삼원촉매 장착엔진을 정밀하게 제어(연료 제어, 공회전 제어, 점화시기 제어, Purge Air 제어 등)하여 삼원촉매의 효율을 향상시키고, 그 결과 배기가스를 감소시킴과 더불어 운전성 및 동력성능을 향상시킨 엔진 전자 제어 시스템의 개요를 간단히 소개하였다. 앞으로도 북미지 역의 배기가스 관련법규가 더욱 강화될 것으로 예상되며, 이에 대응한 엔진 제어 시스템에 대한 지속적인 연구 개발이 필요하리라 생각된다.

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knock in a spark-ignition engine and octane number of gasoline (스파크 점화 기관의 녹킹과 가솔린의 옥탄가)

  • 전광민
    • Journal of the korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.6-9
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    • 1990
  • 본 고에서는 녹킹현상과 녹킹 발생의 결과, 그리고 녹킹과 연료와의 관계등에 대해 개략적으로 설명하려 한다. 녹킹 발생 유무는 흡입공기상태, 스로틀 열림정도, 연소실 형상, 스파크 점화시기, 화염 전파속도 및 연료의 자연 발화 특성에 관계되며 화염 전파속도와 end-gas에 있는 연로의 반응속도와의 경쟁이라 볼수 있다. 연료의 녹킹 발생에 대한 저항성을 나탄내는 척도가 옥탄가이며 옥탄가가 높을 수록 자연 발화하기 어려우므로 녹킹이 잘 일어나지 않는다.

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Comparison of effects of spark timing and fuel ratio on engine efficiency and $NO_x$ emission for fuel of city gas and syngas($H_2$ and CO) (도시가스와 혼합가스($H_2$, CO) 적용 시 점화시기 및 공연비에 따른 발전효율 및 질소산화물 배출량 비교)

  • Jeong, Chul-Young;Lee, Kyung-Teak;Song, Soon-Ho;Chun, Kwang-Min;Nam, Sang-Ick
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.817-820
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    • 2009
  • Research on usage of syngas produced by waste gasification is on going all around the world. Syngas which consists of $H_2$, CO, $CO_2$, $N_2$, has different combustion characteristics from current city gas; due to distinct flame propagation speed of the fuel, syngas has different spark timing and air fuel ratio at maximum generating efficiency. This is why finding both the optimum point of spark timing and air fuel ratio is so important in order to improve thermo efficiency and secure stable running of gas generated by relatively low heating value syngas. Moreover, since emission of $NO_x$ is strictly regulated, it is important to operate lean burn condition that reduces NOx emission.

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