• Fire Science and Engineering
• /
• v.31 no.5
• /
• pp.1-6
• /
• 2017

The fire and explosion properties of combustible materials are necessary for the safe handling, storage, transportation and disposal. Typical combustion characteristics for process safety include auto ignition temperature(AIT). The AIT is an important index for the safe handling of combustible liquids. The AIT is the lowest temperature at which the material will spontaneously ignite. In this study, the AITs and ignition delay times of n-pentanol and p-xylene mixture were measured by using ASTM E659 apparatus. The AITs of n-pentanol and p-xylene which constituted binary system were $285^{\circ}C$ and $557^{\circ}C$, respectively. The experimental AITs and ignition delay times of n-pentanol and p-xylene mixture were a good agreement with the calculated AITs and ignition delay times by the proposed equations with a few A.A.D. (average absolute deviation). Therefore, it is possible to estimate the AITs and ignition delay times in other compositions of n-pentanol and p-xylene mixture by using the predictive equations which presented in this study.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.1
• /
• pp.70-76
• /
• 1992

Ignition of hydrogen-air premixed gas in the vicinity of a hot surface has been investigated. Especially multistep reaction model was compared with a single reaction model. It was found that the multistep model with 48 step elementary chemical reactions produced a phenomenologically reasonable trend in ignition delays. The ignition d(2lays increase as the mixture becomes either fuel-rich or fuel-lean with a minimum near the stoichiometric value. The minimum surface temperature has been deduced by extrapolating predicted ignition delays. It was in quite good agreement with the experimental data.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.1704-1709
• /
• 2004

New reduced chemical kinetic mechanism for prediction of autoignition process of HSDI diesel engine was investigated. For precise prediction of the ignition characteristics of diesel fuel, mechanism coefficients were fitted by the experimental results of ignition delay of diesel spray in a constant volume vessel. Ignition delay of diesel engine on various operation condition was calculated based on the new reduced chemical mechanism. The calculation results agreed well with experimental data.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.5
• /
• pp.9-16
• /
• 2001

End-gas temperatures were measured using CARS technique in a conventional DOHC spark- ignition engine fueled with PRF80. The measured pressure data were analyzed using band pass filter method. The measured CARS temperatures were compared with adiabatic core temperatures calculated from measured pressures. Significant heating by pre-flame reaction in the end gas zone was observed in the late part of compression stroke under both knocking and non-knocking conditions. CARS temperatures measured at 10 crank angle degree before knock occurrence was higher than adiabatic core temperatures. These results indicate that there exist some exothermic reactions in low pressure and temperature region. CARS temperatures began to be higher than the adiabatic core temperature when the end-gas temperatures reached look. The temperature elevation due to the pre-flame reaction correlated better with CARS temperature than with cylinder pressure.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.5
• /
• pp.140-156
• /
• 1997

The combustion characteristics of DI Diesel engine using turbocharging and EGR are numerically studied. Computations are carried out for the wide range of trubochyarged pressures, EGR ratios, and Ar/He dilution. Numerical results indicate that the Ar/He dilution in the intake gas significantly influence the engine performance, the spray combustion process, and the pollutant formation.

• Journal of the Korean Society of Safety
• /
• v.7 no.4
• /
• pp.45-53
• /
• 1992

Sponataneous ignition characteristics for granulated activated carbon were observed by performing experiments at constant ambient temperature and varying the ambient temperature sinusoidally. In case of varying the ambient temperature sinusoidally, the amplitudes of temperature were 5$^{\circ}C$, 1$0^{\circ}C$ and 15$^{\circ}C$ respectively, and the period in each amplitude was varied at an interval of 30minutes from zero to 3hours. As the results of experiments at a constant ambient temperature, the critical spontaneous ignition temperature of the sample decreased as the sample vessel size increased. Apparent activation energy of the sample calculated from the Frank-Kamenetskii's thermal Ignition theory was 38.82［kca1/mo1］ In case of varying the ambient temperature sinusoidally, the critical spontaneous ignition tempera-ture was lower than that at the constant ambient temperature, and the minimum critical spontaneous ignition temperature decreased with the amplitude of heating sinusoidal curve. At the same amplitude, the critical spontaneous ignition temperature decreased until it reached the minimum point and then in-creased as the period increased.

• Journal of the Korean Society of Safety
• /
• v.30 no.2
• /
• pp.21-26
• /
• 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%.

• International Journal of Safety
• /
• v.1 no.1
• /
• pp.47-51
• /
• 2002

This study was performed by measuring the minimum ignition temperature of polyurethane form recovered from the recycling process of the end-of-life home appliances. The critical ignition temperature of polyurethane form was lower as the size of the sample vessel was increased, and that of polyurethane form using cyclopentane as the forming agent was relatively lower than the polyurethane form using CFC and the combustion of cyclopentane-polyurethane form occurred fiercely. It is considered that the recycling process of end-of-life home appliances using cyclopentane-polyurethane form as the insulator would require a special fire and dust explosion prevention measures since there exists a high potential hazard of fire and dust explosion during crushing and storage processes.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.12
• /
• pp.3326-3334
• /
• 1994

To theoretically predict knock occurrence in S. I. engine as a function of engine design and operating parameters, transient local temperature and pressure, mixture density of flame front in combustion period are calculated. We next determined normal combustion period and auto ignition period of end gas using the prediction method on occurrence of spark knock which we suggested. We predict knock occurrence in S. I. engine by comparing consecutively normal combustion period with the auto ignition period of end gas in combustion period. Engine design and operating parameters such as compression ratio, engine speed, spark timing, inlet temperature and pressure are taken into account in this calculations. The predicted result are well matched with the experimental results in turbocharged engine. Therefore, this method will provide the systematic guideline for designing engines in view of knocking limits.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.24-32
• /
• 2000

A brief introduction is given on the conditional moment closure model for turbulent nonpremixed combustion. It is based on the transport equations derived through a rigorous mathematical procedure for the conditionally averaged quantities and appropriate modeling forms for conditional scalar dissipation rate, conditional mean velocity and reaction rate. Examples are given for prediction of NO and OH in bluffbody flames, soot distribution in jet flames and autoignition of a methane/ethane jet to predict the ignition delay with respect to initial temperature, pressure and fuel composition. Conditional averaging may also be a powerful modeling concept in other approaches involved in turbulent combustion problems in various different regimes.