• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.70-76
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• 2013

For the safe handling of styrene, this study was investigated the explosion limits of styrene in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. As a results, the lower and upper explosion limits of styrene recommended 0.9 Vol.% and 8.0 Vol.%, respectively. The lower flash points of styrene by using closed-cup tester were experimented $29^{\circ}C{\sim}31^{\circ}C$. The lower flash points of styrene by using open cup tester were experimented $32^{\circ}C{\sim}36^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for styrene. The experimental AIT of styrene was $460^{\circ}C$.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.37-44
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• 2013

Generally, a reduced chemical mechanism of n-heptane is used as chemical fuel of a 3-D diesel engine simulation because diesel fuel consists of hundreds of chemical components and various chemical classes so that it is very complex and large to use for the calculation. However, the importance of fuel in a 3-D simulation increases because detailed fuel characteristics are the key factor in the recent engine research such as homogeneous charged compression ignition engine. In this study, normal paraffin, iso paraffin and aromatics were selected to represent diesel characteristics and n-dodecane was used as a representative normal paraffin to describe the heavy molecular weight of diesel oil (C10~C20). Reduced kinetics of iso-octane and toluene which are representative species of iso paraffin and aromatics respectively were developed in the previous study. Some species were selected based on the sensitivity analysis and a mechanism was developed based on the general oxidation scheme. The ignition delay times, maximum pressure and temperature of the new reduced n-dodecane chemical mechanisms were well matched to the detailed mechanism data.

• Fire Science and Engineering
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• v.26 no.5
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• pp.48-53
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• 2012

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-Butanol+sec-Butanol system by using ASTM E659 apparatus. The AITs of n-Butanol and sec-Butanol which constituted binary system were $340^{\circ}C$ and $447^{\circ}C$, respectively. The experimental AITs of n-Butanol+sec-Butanol system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation).

• Fire Science and Engineering
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• v.27 no.1
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• pp.8-13
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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 Benzene and n-Hexane system by using ASTM E659 apparatus. The AITs of Benzene and n-Hexane which constituted binary system were $583^{\circ}C$ and $240^{\circ}C$, respectively. The experimental AITs of Benzene and n-Hexane system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation).

• Journal of Mechanical Science and Technology
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• v.15 no.6
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• pp.699-708
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• 2001

This paper presents a new approach to the AFR (Air-to-Fuel Ratio) control problem, which is based on the wide-band oxygen sensor output. The dedicated nonlinear controller is based on the feedback lineaization technique. It is well known that the feedback linearizing control technique requires an exact model of the plant for the cancellation of plant nonlinearities. A sliding mode control scheme is applied which can effectively compensate the modeling uncertainties. The measurement time delay of an oxygen sensor limits the gain of the feedback controller. Hence, time delay compensation procedure is necessary for the improvement of control performance. The Smith predictor is adopted to compensate the effects of time delay. The simulation and experimental results show that the proposed controllers can effectively reduce the transient peaks of AFR in spite of fast tip-in and tip-out maneuvers of the throttle.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.1-8
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• 2013

The water-in-fuel droplets were applied to investigate the effect of mixing ratio between water and decane, ambient temperature, droplet size and spacing between droplets on ignition and micro-explosion in a heated chamber with high temperature. The ignition temperature of droplet was found lower as the droplet size was increased and the contents of water was decreased. The life time of droplet, however, decreases as the contents of water increases due to the micro-explosion. The occurrence of micro-explosion also increases as the size of droplets and the ambient temperature increase. The flame spread speed gets faster as the contents of water and the number of suspender decreases.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.225-231
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• 2021

Sesame seed oil cakes are classified as the animal or plant origin among the flammable liquids, and the fire occurs due to the spontaneous ignition through the accumulation of heat during the storage of residues after the extraction of sesame oil. In order to elucidate the cause of the spontaneous ignition of sesame seed oil cakes, the thickness (3 cm, 5 cm, 7 cm and 14 cm) of the sample container was varied, and the spontaneous ignition temperature was measured depending on the storage volume. Thus, the spontaneous ignition temperature was measured to be 180 ℃ at the thickness of 3 cm, 160 ℃ at 5 cm, 145 ℃ at 7 cm and 130 ℃ at 14 cm. As the thickness of the sample container increased, the critical ignition temperature decreased, and the induction time to spontaneous ignition and the time to reach the maximum temperature became longer. Furthermore, the apparent activation energy by the critical ignition temperature, which is the average temperature of ignition and non-ignition, was 97.10 [kJ/mol]. With these data, ignition characteristics of sesame seed oil cakes were determined.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.121-134
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• 1994

Shock tube investigation of ethylene oxide-$0_{2}-N_{2}$ mixture have been performed to reveal detonation characteristics of the mixture in terms of detonation pressure and speed. Theoretical calculation of thermodynamic parameters at the Chapmann-Jouguet detonation of the mixture has been also performed. A comparision of the observed results with the calculated ones can lead us to predict the detonation parameters of ethylene oxide in an artificial air. In addition, we have observed ignition delay times of ethylene oxide mixtures. The best fit of the observed delay times to Arrhenius gas kinetic relation gives : ${\tau}=10^{-144}{e{xp}}(E_a/RT)[C_{2}H_{4}O]^{-4.8}[O_{2}]^{-12.4}[N_{2}]^{-14.1}$ $E_a=3.67kcal/mole$ The observed activation energy is markedly reduced, compared with the case of ethylene oxide diluted in Ar. It could be due to the factor that $N_2$ play a role as detonation promoter yielding very reactive NOx radicals.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.45-53
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• 2004

An experimental study was carried out to obtain the fundamental data about the effects of radicals induced injection on premixture combustion. A constant volume combustor divided to the sub-chamber and the main chamber was used. The volume of the sub-chamber is set up to occupy less than 1.5％ of that of whole combustion chamber. Radial twelve narrow passage holes are arranged between the main chamber and the sub-chamber. The products including radicals generated by spark ignition in the sub-chamber will derive the simultaneous multi-point ignition in the main chamber. While the equivalence ratio of pre-mixture in the main chamber and the sub-chamber is uniform. We have examined the effects of the sub-chamber volume, the diameter of passage hole, and the equivalence ratio on the combustion characteristics by means of burning pressure measurement and flame visualization. In the case of radical ignition method(RI), the overall turning time including the ignition delay became very short and the maximum burning pressure was slightly increased in comparison with those of the conventional spark ignition method(SI), that is, single chamber combustion without the sub-chamber. The combustible lean limit by RI method is extended to more ER=0.25 than that by SI method. Therefore the decrease of every emission including NOx and the improvement of fuel consumption is anticipated due to lean burn.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.45-51
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• 2012

The MSITs(Minimum Spontaneous Ignition Temperatures) or AITs(Autoignition Temperatures) describe the minimum temperature to which a substance must be heated, without the application of a flame or spark, which will cause that substance to ignite. This study measured the MSITs(Minimum Spontaneous Ignition Temperatures) of n-pentanol+ethylbenzene system by using ASTM E659 apparatus. The MSITs of pure n-pentanol and ethylbenzene were $285^{\circ}C$ and $475^{\circ}C$, respectively. The experimental MSITs of n-pentanol+ethylbenzene system were a in good agreement with the MSIT calculated by the proposed equations with a few A.A.D.(average absolute deviation).