• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.45-52
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• 2006

The 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. The AITs are often used as a factor in determining the upper temperature limit for processing operations and conditions for handling, storage and transportation, and in determining potential fire hazard from accidental contact with hot surfaces. The measurement AITs are dependent upon many factors, namely initial temperature, pressure, volume, fuel/air stoichiometry, catalyst material, concentration of vapor, time lag. Therefore, the AITs reported by different ignition conditions are sometimes significantly different. This study measured the AITs of benzene, toluene and xylene isomers from time lag using AS1M E659-78 apparatus. The experimental ignition delay times were a good agreement with the calculated ignition delay times by the proposed equations wtih a few A.A.D.(average absolute deviation). Also The experimental AITs of benzene, toluene, o-xylene, m-xylene and p-xylene were $583^{\circ}C,\;547^{\circ}C,\;480^{\circ}C,\;587^{\circ}C,\;and\;557^{\circ}C$, respectively.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.113-121
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• 2015

This study aims to examine the risk of electrical fire in places where electric heat wires are used. In general, the use of electric heating wires is becoming more common and prevalent in a bid to prevent increasing damage caused by freezing and bursting in residential water pipes, factory pipes and irrigation pipes in vinyl greenhouse and a variety of heat wire products are available in market with legal safety requirements imposed on them. However, the widespread use of anti-freezing burst heat wire products has caused increasing incidents of fire, which often fail to be incorporated into statistics due to quick onsite extinguishing and insignificant damage although damage is gradually on the rise. Against this backdrop, this study aims to look into the possibility of ignition caused by electric heat wires and the mechanism of how it turns into catching fire through overheat and short circuit tests for anti-freezing burst electrical heat wires (hereinafter called the 'heat wire') and expects to serve as the basis for further observations and analyses on the cause of fire and the process of ignition in a scientific manner.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.12 s.255
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• pp.1181-1187
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• 2006

Stringent regulations of exhaust emission from vehicles become a major issue in automotive industries. In SI engines, it is one of the crucial factor to reduce exhaust emissions during cold start in order to meet stringent regulations such as SULEV or EURO-4, because SI engines emit a large portion of total harmful exhaust compounds when they are cold. At early stages of cold start in gasoline engines, exhaust gas temperature plays a key role to improve three way catalyst by virtue of fast warmup. Therefore, this study focused on the increase of exhaust gas temperature under controls of engine operating parameters such as spark ignition timing, valve overlap by virtue of intake VVT and catalyst heating function. Furthermore, effects on harmful emission due to these parameters are also investigated. Experiments showed that retarded spark ignition timings and increased valve overlap may be helpful to increase exhaust gas temperature. It was also found that $NO_x$ was decreased with increased valve overlap. This study also showed that sudden changes in ISA and amount of fuel due to the deactivation of catalyst heating function cause temporal increase of harmful emissions.

• Journal of Hydrogen and New Energy
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• v.30 no.6
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• pp.499-504
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• 2019

Due to the rapid spread and low minimum ignition energy of hydrogen, rupture is highly likely to cause fire, explosion and major accidents. The self-ignition of high-pressure hydrogen is highly likely to ignite immediately when it leaks from an open space, resulting in jet fire. Results of the diffusion and leakage simulation show that jet effect occurs from the leakage source to a certain distance. And at the end of location, the vapor cloud explosion can be occurred due to the formation of hydrogen vapor clouds by built-up. In the result, it is important that depending on the time of ignition, a jet fire or a vapor cloud explosion may occur. Therefore, it is necessary to take into account jet effect by location of leakage source and establish a damage minimizing plan for the possible jet fire or vapor cloud explosion. And it is required to any kind of measurements such as an interlock system to prevent hydrogen leakage or minimize the amount of leakage when detecting leakage of gas.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.113-118
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• 2011

In this study, investigation and appraisal method for the scene of a fire according to electrical fire hazards of hair dryer which is usually used at living space are presented. Hair dryer is briefly composed of heating part, wind part and control part. Electrical fire hazards of hair dryer are insulation destruction of power cord, ignition by overheat of heating coil, scattering spark on inside dust, overheat of motor by fan shackle, ignition by carelessness of user, and so on. Fire cause by hair dryer can be perceived through investigation about half-disconnection of power cord, contact badness of power plug, verification of heating coil, fan and switch. These results are expected to be utilized effectively in a countermeasure to prevent an electrical fire by hair dryer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.207-210
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• 2009

The AP/HTPB composite propellant is a common choice for solid rocket propulsion. The externally heated rocket via fires, for instance, can cause the energetic substance to ignite, and this may lead to a thermal runaway event marked by a severe explosion. In order to develop preventive measures to reduce the possibility of such accidents in propulsion systems, we investigate the ignition and initiation properties of AP/HTPB propellant.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.87-94
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• 2009

In the fire there are fusion signs and damage by fire, and insulation aging and carbonization of the electric wiring in the ignition spot because of special characteristic of the appliance in the electricity fire. Because of the physical factor applied in the damage of fire, the decision of ignition spot by eye investigation is insufficient. In this paper, the cause of electricity fire is researched. The focus is on the operation state of operated MCCB(Molded Case Circuit Breaker) at the time of electricity fire. Through grasping the operation principle of MCCB and the experiment, the state of MCCB after fire suppression is discriminated. The distinction possibility on the exist of electricity fire is proposed.

• International Journal of Safety
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• v.9 no.1
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• pp.1-5
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• 2010

On-site examinations and fire simulation were carried out to speculate on causes of the fire at an indoor shooting range in Busan. An experiment on the ignitability of unburned gunpowder was also conducted. Cigarette was the most likely source of ignition for the fire, while impact of a stray bullet failed to ignite the unburned gunpowder. The explosion in the shooting area was presumed to be caused by violent combustion of the polyurethane foam and unburned gunpowder accumulated on it. Fire safety measures include prohibit of use of profile polyurethane foam, complete clean-up of unburned gunpowder, and removal of steel components from the bullet trap.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.580-583
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• 2001

A high ignition voltage is required for the metal halide (MHD) lamp. In this paper, the ballast ignited by internal LC resonance of buck converter with minimum size is proposed. For minimizing the ignition current for device safety, the characteristic impedance is maximized. But this results In a large steady state ripple, which may cause the accoustic resonance. The steady state ripple cancellation network using the coupled inductor is proposed.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.526-533
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• 2009

Fire accidents reported to the National Emergency Management Agency (NEMA) during 1997.2006 in Korea are investigated. A survey of 23523 accidents due to fires is presented. Statistical comparisons based on the type of accidents and the causes of fires are analysed. The results indicated that 27.5% of the total number of fires are residental houses and apartments and 18.0% were motor vehicles. Electricity was classified to be the highest cause of fire ignition sourses and smoking was the second source of ignition.