• Title/Summary/Keyword: Ignition Delay time

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The Minimum Autoignition Temperature Behavior(MAITB) of n-Decane and Acetic acid Mixture (n-Decane과 Acetic acid 혼합물의 최소자연발화온도 거동)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.28 no.2
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    • pp.49-54
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    • 2013
  • The autoignition temperature(AIT) is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs and ignition delay time for n-Decane and Acetic acid system by using ASTM E659 apparatus. The AITs of n-Decane and Acetic acid which constituted binary system were $212^{\circ}C$ and $512^{\circ}C$, respectively. The experimental AITs of n-Decane and Acetic acid system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation). And n-Decane and Acetic acid system was shown the minimum autoignition temperature behavior(MAITB).

The Combustion Characteristics of Diesel-Biodiesel Blended Fuel Droplets Using the Modified Image Processing Method According to Flame Instability (화염 불안정성에 따른 개선된 이미지 처리 기법을 활용한 디젤-바이오디젤 혼합 연료 액적의 연소 특성)

  • Choi, Ju Hwan;Lim, Young Chan;Suh, Hyun Kyu
    • Journal of ILASS-Korea
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    • v.26 no.3
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    • pp.142-148
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    • 2021
  • The objective of this study is to analyze the basic flame behavior characteristics using the single fuel droplet combustion of diesel, palm-based biodiesel, and canola-based biodiesel. The results were compared and analyzed through the post processed image, which was applied the threshold level for removing noise in the raw image. The raw image was taken by a high-speed camera during the entire combustion process. At the same time, the maximum flame length, which was measured by the application code of the MATLAB program, the ignition delay, and the combustion period were compared and analyzed.

A Numerical Study on Interaction and Combustion of Droplets Injected into a Combustor (연소실에 분사된 액적 간의 상호작용과 연소현상에 대한 수치적 연구)

  • Kook, J.J.;Park, S.H.
    • Journal of the Korean Society of Combustion
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    • v.4 no.1
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    • pp.17-26
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    • 1999
  • Vaporization, ignition and combustion of fuel droplets in tandem array are theoretically investigated to understand the droplet interactions in combustors. Including the effects of density variation in gas-phase, internal circulation and transient liquid heating, a numerical studies are performed by changing parameters such as initial droplet temperatures, initial droplet spacings, initial Reynolds numbers, surrounding gas temperatures, and activation energies of fuel vapors. Combustion regime maps classify the droplet combustion phenomena according to the configuration and location of the flame with respect to injection Reynolds numbers and surrounding gas temperatures. In addition, it is shown that the dynamic histories of droplets and ignition delay times are dependent on droplet size ratios and initial spacings of tandem droplets.

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A Study on the Appropriateness of the Combustible Properties of MSDS for o-Cresol (오토크레졸의 MSDS 연소특성치의 적정성 연구)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.30 no.2
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    • pp.21-26
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    • 2015
  • For the safe handling of o-cresol, this study was investigated the explosion limits of o-cresol in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower flash points of o-cresol by using closed-cup tester were experimented in $77^{\circ}C$ and $80^{\circ}C$. The lower flash points of o-cresol by using open cup tester were experimented in $86^{\circ}C$ and $87^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for o-cresol. The AIT of o-cresol was experimented as $495^{\circ}C$. The lower explosion limit(LEL) by the measured the lower flash point for o-cresol was calculated as 1.27 Vol%.

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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The Measurement and Investigation of Combustible Properties for n-Hexane (노말헥산의 연소특성치의 측정 및 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.26 no.2
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    • pp.36-41
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    • 2011
  • For the safe handling of n-hexane, the explosion limit at $25^{\circ}C$, the temperature dependence of the explosion limits and the lower flash point were investigated. And AITs(auto-ignition temperatures) by ignition delay time for n-hexane were experimented. By using the literatures data, the lower and upper explosion limits of n-hexane recommended 1.0 Vol% and 8.0 Vol%, respectively. In this study, the lower flash points of n-hexane recommended $-23^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-hexane, and the experimental AIT of n-hexane was $240^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of n-hexane is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

The Investigation of Compatibility of Combustible Characteristics for n-Tridecane (노말트리데칸의 연소특성치의 적정성 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.27 no.3
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    • pp.83-88
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    • 2012
  • For the safe handling of n-tridecane, the lower flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. Also lower explosion limits by the lower flash points were calculated. The lower flash points of n-tridecane by using closed-cup tester were experimented $92^{\circ}C$ and $96^{\circ}C$. The lower flash points and fire point of n-tridecane by using open cup tester were experimented 100 oC and 103 oC, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 apparatus for n-tridecane. The experimental AIT of n-tridecane was 223 oC. The calculated lower explosion limit by using measured lower flash point 92 oC for n-tridecane was 0.6 Vol.%.

The Measurement of Combustible Properties of Acetic Anhydride for the Compatibility of MSDS (MSDS 적정성을 위한 아세틱안하이드리드의 연소특성치 측정)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.29 no.4
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    • pp.85-90
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    • 2014
  • For the safe handling of acetic anhydride, this study was investigated the explosion limits of acetic anhydride in the reference data. And the lower flash points, upper flash points, and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower and upper explosion limits of acetic anhydride by the investigation of the literatures recommended 2.9 Vol% and 10.3 Vol.%, respectively. The lower flash point of acetic anhydride by using Setaflash closed-cup tester was experimented $49^{\circ}C$. The lower flash point acetic anhydride by using Tag and Cleveland open cup tester were experimented $55^{\circ}C$and $62^{\circ}C$, respectively. Also, this study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for acetic anhydride. The experimental AIT of acetic anhydride was $350^{\circ}C$.

Effects of Fuel Blending Ratio and Oxygen Concentration on Auto-ignition Characteristics of n-Decane/Ethanol Blended Fuels (연료 혼합비율 및 산소농도가 노말데케인/에탄올 혼합연료의 점화특성에 미치는 영향)

  • Oh, Chae Ho;Kang, Ki Joong;Choi, Gyung Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.11
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    • pp.749-757
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    • 2017
  • To cope with the development of alternative fuels and international environmental regulations, this study provides a numerical analysis of the effects of composition and temperature changes of n-decane and ethanol on auto-ignition characteristics. CHEMKIN-PRO is used as the analysis program and the LLNL model is used as the reaction model. The numerical results show that the ignition delay time increases as the mole fraction of ethanol increases for temperatures below 1000 K, where low temperature reactions occur. Because of the high octane number of ethanol, the high percentage of ethanol delays the increase in the concentration of OH radicals that cause ignition. The oxygen concentration in the mixture is changed to apply the exhaust gas recirculation and a numerical analysis is then performed. As the oxygen concentration decreases, the total ignition delay time increases because the nitrogen gas acts as a thermal load in the combustion chamber.

Theoretical Analysis of Ignition of a Coal-Water Slurry Droplets with Interior Temperature Distribution (내부 온도분포를 고려한 Coal-Water Slurry의 점화현상에 관한 이론적 해석)

  • Choi, C.E.;Baek, S.W.;Kim, J.W.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.7 s.94
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    • pp.1823-1832
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    • 1993
  • CWS(coal-water slurry) is used for application in power plants, boilers, industrial furnaces. A single coal-water slurry droplet ignition has been examined to reveal the basic nature of their evaporation, volatilization and heating processes. The interior droplet temperature distribution has been considered. The effect of coal thermal conductivity, droplet size, water fraction in the slurry, gas temperature and velocity and radiation on the ignition phenomena were also studied. Either increasing the velocity and gas temperature or decreasing the droplet size and water fraction in the slurry may reduce the time for evaporation and ignition delay time.