• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.461-468
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• 2022

This study is focused on the ignition of ceiling insulation depending on working condition of Sprinkler head in underground parking lot fire. When temperature changes of same point were measured depending on sprinkler's working condition, in Scenario 1, inner temperature at border of spray applied material(SP-2) of ceiling part near the fire and ceiling insulation(blowing polystyrene) was 658.27℃ and its which inner maximum temperature is higher than 427℃ which is the ignition point of ceiling insulation(blowing polistyrene), so it was observed that flame is ignited on the ceiling insulation and spread fire. In scenario 2, Inner fire temperature at border of spray applied material(SP-2) and ceiling insulation(blowing polystyrene) near the fire was 53.10℃ and it was lower than ignition point so it was observed that flame was not ignated on the ceiling insulation. As a result, it was foreseen that possibility of ignition on the ceiling insulation depending on working condition of sprinkler.

• Fire Science and Engineering
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• v.23 no.5
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• pp.57-65
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• 2009

This study was intended to conduct a Real-scale fire test to predict the fire behavior by unit space at the apartment building where a huge casualties and injuries are likely. After setting the inflammables inside the house, the test aimed to identify the fire characteristics to each unit item was carried out. The house was divided into 4 unit space such as kitchen, living room, bedroom and a study for a real scale fire test. As a result, bedroom reached to flashover state in 5minutes after setting the fire, indicating a rapid fire growth such as 7433.3kW of maximum thermal emissivity, 578.6ppm of carbon monoxide, 1.25ppm of carbon dioxide and $1,350^{\circ}C$ of maximum indoor temperature. Particularly, the fire growth was made up to critical temperature which might cause a severe damage to the people within 3minutes, if the fire were not extinguished at inflammable space at the early stage of fire, which stressed the need of early response. The result of a real scale fire test could be compared with the outcome of expanded simulation test and used in predicting the fire spread at the space for different use.

• 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.28 no.5
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• pp.23-29
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• 2014

The present study has been conducted to investigate the validity of the computational fire model and the results predicted by BRANZFIRE zone model and FDS field model are compared with a real scale fire test with spray fire in a multi-compartment. The liquid spray fires fueled with toluene and methanol are used as the fire source and the quantitative measurement of heat release rate is performed in an isolated ISO-9705 compartment with a standard door opening. The temperature field predicted by FDS model showed good agreement with the measurement in the fire room and the corridor, and BRANZFIRE model also gave acceptable result in spite of its simplicity and roughness. The mean temperature predicted by FDS model corresponds with measurement within maximum discrepancy range of 25% and the overall mean value of FDS model matched well with experimental data less than 10%. This study can contribute to establish the limitation and application scope of computational fire model and provide reference data for applying to reliable fire risk assessment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.60-67
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• 2019

In general, a reinforced concrete slabs are known to have a high fire resistance performance due to thermal properties of concrete materials. However, according to previous research, the thermal behavior of voided slabs is reported to be different from that of conventional RC solid slabs, and the differences seem to be caused by the air layer formed inside the voided slab. Therefore, it is difficult to estimate the temperature distribution of the voided slab under fire by using the existing methods that do not take into account the air layer inside the voided slab. In this study, a numerical analysis model was proposed to estimate the temperature distribution of voided slabs under fire, and evaluated. Heat transfer of slabs under fire is generally caused by conduction, convection and radiation, and time-dependent temperature changes of slab can be determined considering these phenomena. This study proposed a numerical method to estimate the temperature distribution of voided slabs under fire based on a finite difference method in which a cross-section of the slab is divided into a number of layers. This method is also developed to allow consideration of heat transfer through convection and radiation in air layer inside of slabs. In addition, the proposed model was also validated by comparison with the experimental results, and the results showed that the proposed model appropriately predicts the temperature distribution of voided slabs under fire.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.4
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• pp.313-327
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• 2008

Thermo-mechanical coupled behavior of an underground structure during a fire accident have not been fully understood yet. Moreover, when such a thermo-mechanical coupled behavior is not considered in numerical analyses based on conventional heat transfer theory, fire-induced damage zone in an underground structure can be considerably underestimated. This study aims to develop a FEM-based numerical technique to simulate the thermo-mechanical coupled behavior of an underground structure in a fire accident. Especially, an element elimination model is newly proposed to simulate fire-induced structural loss together with a convective boundary condition. In the proposed model, an element where the maximum temperature calculated from heat transfer analysis is over a prescribed critical temperature is eliminated. Then, the proposed numerical technique is verified by comparing numerical results with experimental results from real fire model tests. From a series of parametric studies, the key parameters such as critical temperature, element size and temperature-dependent convection coefficients are optimized for the RABT and the RWS fire scenarios.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.19-24
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• 2000

밀폐된 실내에서 화재현상을 예측하기 위한 해석 방법은 Zone 모델과 Field 모델로 대별된다. Zone 모델은 상부층과 하부층의 온도, 시간에 따른 연기층의 높이 등을 실험값을 대입한 간단한 대수식으로 계산하여, 계산이 간편한 장점이 있으나 각 위치에 대한 온도와 유속을 구할 수 없다. (중략)

• Fire Science and Engineering
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• v.15 no.1
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• pp.23-33
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• 2001

The utility tunnels are the important facility as a mainstay of country because of the latest communication developments. However, the utilities tunnel is difficult to deal with in case of a fire accident. When a cable burns, the black smoke containing poisonous gas will be reduced. This black smoke goes into the tunnel, and makes it difficult to extinguish the fire. Therefore, when there was a fire in the utility tunnel, the central nerves of the country had been paralyzed, such as property damage, communication interruption, in addition to inconvenience for people. This paper is based on the fire occurred in the past, and reenacting the fire by making the real utilities tunnel model. The aim of this paper is the scientific analysis of the character image of the fire, and the verification of each fire protection system whether it works well after process of setting up a fire protection system in the utilities tunnel at a constant temperature. The fire experiment was equipped with the linear heat detector, the fire door, the connection water spray system and the ventilation system in the utilities tunnel. Fixed portion of an electric power supply cable was coated with a fire retardant coating, and a heating tube was covered with a fireproof. The result showed that the highest temperature was $932^{\circ}c$ and the linear heat detector was working at the constant temperature, and it pointed at the place of the fire on the receiving board, and Fixed portion of the electric power supply cable coated with the fire retardant coating did not work as the fireproof. The heating tube was covered with the fireproof about 30 minutes.

• Fire Science and Engineering
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• v.25 no.6
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• pp.184-189
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• 2011

This study measured the AITs of n-butanol + n-decane system from ignition delay time (time lag) by using ASTM E659 apparatus. The AITs of n-butanol and n-decane which constituted binary system were $340^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-butanol + n-decane 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.11 no.2
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• pp.3-10
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• 1997

Attempts are being made to investigate temperatures dependence of minimum ignition energy (MIE) based on concept of quantity of heat and thermal ignition theory. Regression equations for predicting MIE by means of temperature variations on the basis of statistical and mathematical methods are proposed. This study is undertaken to learn what proposed method is satisfactory hydrocarbons(propane and pentane). The proposed method has been tested and compared sucessfully with previously reported data in various journal.