• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.216-217
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• 2020

As the fire inside the building grows rapidly, ejected flame from an opening occurs due to flashover. As a result, the number of cases where the flame spreads to the exterior of the building and rapidly expands to the upper floor is increasing. In particular, in the case of the fire in the Daebong Green Apartment, Uijeongbu in 2015, it was a case where the flame spread to adjacent buildings due to the opening eruption flame from the first ignited building, causing great damage to three apartments. Therefore, this study is to introduce an international standard under development that estimates the shape and properties of the ejected flame from an opening and quantitatively evaluates the radiant heat flux received by the exterior wall of the building by assuming the occurrence of the ejected flame from an opening.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.151-159
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• 2003

According to the records, approximately 50 percent of power failure were caused by lightning. Conventional fault preventive measures against lightning include reduction of the footing resistance of the tower, multiplication of overhead ground wires and unbalanced insulation of the double circuit transmission tower. In addition to these, transmission line arresters have been recently appeared as an alternatives. In this paper an unbalanced insulation method with transmission line arrester was assumed as another countermeasure against simultaneous double circuit trip of 154 kV transmission line by lightning strike. The lightning performance of line arrester was compared with conventional insulation concept using different numbers of porcelain and glass insulator. Larger numbers of insulator simply increase flashover current level by lightning but the lightning performance doesn't proportional to it. EMTP simulation and predictive calculation of lightning failure rate were carried out to evaluate the performance.

• Fire Science and Engineering
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• v.23 no.4
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• pp.40-49
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• 2009

A large-scale fire test was conducted for interior materials from a vehicle installed within a fire test room (ISO 9705). The interior materials are satisfying the Korean guideline for the safety of rail vehicles, where the guideline has taken effect since December 2004 in Korea. The output of ignition source (gas burner) was increased in several controlled steps. The objectives of this test are to assess the fire performance in terms of ignition and flame spread on interior lining materials and to provide data on an enclosure fires involving train interior materials that grow to flashover. These data will be used to develop and calibrate models for fire growth on the interiors of the railway vehicle.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.10-14
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• 2007

Flash point is one of the major physical properties used to evaluate fire hazards of the combustible liquids. Properties showing relative fire hazards of the combustible liquids are heat release rate(HRR), peak heat release rate(PHRR), time to ignition(TTI), mass loss rate, and yield of $CO/CO_2$. The relationships between flash points and fire properties of the combustible liquids were examined in this study. For this study, mass loss rate and time to ignition were measured to calculate fire properties of the combustible liquids. The results showed that good correlations could be found between flash point and time to ignition, time to peak heat release rate, and the propensity to flashover. From a presented results, the parameters can be used to evaluate relative hazards of the combustible liquids on fire.

• Journal of the Korean Society for Railway
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• v.13 no.5
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• pp.481-487
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• 2010

A room scale fire test was done for interior materials from a subway vehicle installed within an ISO 9705 fire test room. The interior materials are the old ones which were made before the new fire safety guideline of subway vehicles. The output of ignition burner was increased in controlled steps to CEN/TS 45545-1. The objectives of this interior fire test are to assess the fire performance in terms of ignition and flame spread on interior lining materials and to provide data on an enclosure fires involving subway vehicle interior materials that grow to flashover. Temperatures, heat flux and heat release rate variations verse time of the test are measured. Heat release rate is compared with that of calculated by modified flaming area based summation method. These test results will be used for verification of CFD fire simulation of full subway vehicle.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.38-44
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• 2015

For this study, fire tests were performed targeting household items (Sofa, Drawer, Refrigerator, Washing machine) using a large cone calorimeter (Large Scale Cone Calorimeter, LSC). The data were obtained focusing on the fire characteristic of the data when the actual fire occurs. The study results showed the following mean HRR of the household items; drawer 2843 KW, sofa 2939 KW, washing machine 719 KW, refrigerator 2907 KW, and THR is found in sofa 2202 MJ, drawer 1559 MJ, refrigerator 1193 MJ, washing machine 627 MJ. From the result, it could be found that the sofa can cause significant heat generation when the fire occurs, and the flashover tendency was found relatively high in compartment fire. In addition, a weight of the four our household items was reduced sharply in a similar time (20min before and after) degree after ignition. The drawer and sofa which has a high heat release can be considered to speed up the fire spread as their weight decrease rapidly and showed relatively weak to the fire compared to the refrigerator and washing machine.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.7-13
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• 2017

An experimental study was conducted to identify the quantitative measurement bias for the bare-bead thermocouple (TC), which was widely used for measuring temperature in fire experiments. To this end, an apparatus could be controlled individually gas flow rate, preheating temperature and incident radiative heat flux was developed to simulate the thermal environments of fire. A relative measurement bias of bare-bead TC was evaluated with the comparison of double-shield aspirated TC. As a result, the relative measurement bias of bare-bead TC was gradually increased with the increase in radiative heat flux with constant gas temperature. The relative bias was also significantly increased with the decrease in gas temperature. Quantitatively, at the gas temperature of $20^{\circ}C$, the bare-bead TC had the relative bias of approximately 400% with the radiative heat flux of $20kW/m^2$ corresponding to thermal radiation level of the flashover. The present study was intend to provide fire researchers with methodologies for the reanalyses of temperature measured using bare-bead TC, radiation corrections, and validation of fire modeling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.495-496
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• 2008

This paper describes the influence of Ultra-violet irradiation on time to tracking resistance of epoxy insulating materials by use of the inclined plane test. And, the influence of surface degradation was evaluated through several method such as measurement of contact angle, surface roughness, using a scanning electron microscopy. As the 1000 hours of the surface degradation with UV-CON, the flashover time decreases at different rates depending on epoxy resin and silicone rubber specimen. As the duration of the surface degradation with UV-CON is prolonged, the contact angle of epoxy resin decreases at the rate of degradation time, while that of silicone rubber was not exchanged. It is assumed that this phenomenon is related to the decrease in hydrophobicity of the surface of the materials. Also, as to epoxy resin, the decrease of hydrophobicity due to surface degradation with UV-CON is greater than that resulting from surface degradation with WOM. The UV radiation produced chalking and crazing on the surface of the insulating materials specimen.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.193-200
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• 1997

Flame spread and heat release properties and incident heat flux of interior materials subject to an igniter heat flux in a compartment are investigated and compared by using computer model. A comer fire ignition source is maintained for 10 minutes at 100 kw and subsequently increased to 300kw. In executing the model, base-line material properties are selected and one is changed for each run. Also 4 different igniter heat flux conditions and examined. Results are compared for the 12 different materials tested by the ISO Room Comer Test (9705). The time for total energy release rate to reach 1MW is examined. The parameters considered include flame heat flux and thermal inertia, lateral flame spread parameter, heat of combustion and effective heat of gasfication. The model can show the importance of each property in causing fire growth on interior Hnish materials in a compartment. The effect of ignitor heat flux and material property effects were demonstrated by using dimensionless parameters a, b and Tb. Results show that for b greater than about zero, flashover time in the ISO Room-Corner test is principally proportional to ignition time and nothing more.

• Fire Science and Engineering
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• v.32 no.1
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• pp.16-23
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• 2018

In a closed-compartment with various configurations, the correlation that can predict the maximum heat release rate (HRR) with the changes in internal volume and fire growth rate was investigated numerically. The volume of the compartment was controlled by varying the length ratio based on the bottom surface shape of the ISO 9705 fire room, where the ceiling height was fixed to 2.4 m. As a main result, the effect of a change in ceiling height on the maximum HRR was examined by a comparison with a previous study that considered the change in ceiling height. In addition, a more generalized correlation equation was proposed that could predict the maximum HRR in closed-compartments regardless of the changes in ceiling height. This correlation had an average error of 7% and a maximum error of 19% for various fire growth rates when compared with the numerical results. Finally, the applicability of the proposed correlation to representative fire compartments applied to the domestic performance-based design (PBD) was examined. These results are expected to provide useful information on predicting the maximum HRR caused by flashover in closed-compartments as well as the input information required in a fire simulation.