• Title/Summary/Keyword: 구획화재

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A Numerical Study on the Effect of Volume Change in a Closed Compartment on Maximum Heat Release Rate (밀폐된 구획실의 체적변화가 최대 열발생률에 미치는 영향에 관한 수치해석 연구)

  • Yun, Hong-Seok;Nam, Dong-Gun;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.19-27
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    • 2017
  • The effects of changes in area and location of fire source, fire growth rate, and volume of compartment on the major fire characteristics, including heat release rate, in closed compartment fires were examined. To this end, a fire simulation using Fire Dynamics Simulator (FDS) was performed for ISO 9705 room with a closed opening. As main result, it was found that the changes in the area and location of fire source did not significantly affect the thermal and chemical characteristics inside the compartment, such as maximum heat release rate, total heat release, maximum temperature at upper layeras well as species concentrations. However, increasinthe fire growth rate and volume of compartment resulted in increase of the maximum heat release rate and total heat release, decrease in the limiting oxygen concentration and increase in the maximum CO concentration. Finally, a methodology for the application of fire growth curves to closed compartment fires was proposed by deriving the correlation of the maximum heat release rate expressed as a function of the fire growth rate and the volume ratio of compartment based on the ISO 9705 room.

Uncertainty Analysis of the Optical Smoke Density Measurement through the Doorway in a Compartment Fire (구획화재의 출입구를 통한 광학적 연기밀도 측정의 불확실성 해석)

  • Kim, Sung-Chan
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.75-79
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    • 2013
  • The present study measured the light transmission to quantify the smoke density(smoke mass concentration) through the doorway in a compartment fire and performed the uncertainty analysis to evaluate the reliability of the measurement technique. The optical light extinction method based on Bourguer's law was applied to estimate the smoke density of doorway exhausting smoke flow in upper layer of a compartment for methane gas fires. The measurement uncertainty of the light extinction measurement was evaluated for the light transmittance, path length, and specific mass extinction coefficient and the expanded uncertainty was estimated about 20% with confidence level of 95%. The mean smoke density through the doorway for the methane fire was calculated for quasi-steady fire and the smoke density linearly increased as the GER increased.

Prediction of sprinkler activation time in compartment fire (구획화재에서의 스프링클러 작동시간 예측 연구)

  • 김명배;한용식
    • Fire Science and Engineering
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    • v.10 no.4
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    • pp.13-18
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    • 1996
  • A general description of sprinkler activation time in compartment-fire-generated smoke layers is made. For calculation of the time hot layer temperature is obtained from two-layer zonal model and time constant of sprinkler is measured. Upper-layer thickness at the instant of sprinkler activation is also presented with changes of opening area. The output of the present study provide inputs for the interaction modeling of sprinkler spray and compartment fire environment, which simulates fire suppression phenomena. Futhermore, experiments are performed in mock-up with gasoline pool fire in order to evaluate the reliability of the model.

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A Study on the Combustion Efficiency Concept in Under-ventilated Compartment Fires (환기부족 구획화재에서 연소효율 개념에 대한 고찰)

  • Ko, Gwon-Hyun;Park, Chung-Hwa;Hwang, Cheol-Hong;Park, Seul-Hyun
    • Fire Science and Engineering
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    • v.24 no.6
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    • pp.145-152
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    • 2010
  • A study on combustion efficiency concept was conducted for the under-ventilated fires in a fullscale ISO 9705 room. In particular, a comparison between global combustion efficiency (CE) measured outside the compartment and local CE measured at upper layer inside the compartment was focused. Heptane, toluene and iso-propanol were used to consider the wide ranges of heat of combustion and soot yield. As a result, the global CE was decreased linearly with increasing in global equivalence ratio (GER). On the other hand, the decreasing rate of local CE was increased gradually with increasing in GER. From these results, it was known that the information on local CE was very useful parameter to understand the fire phenomena inside the compartment. In addition, it was discussed that the local CE might be used as an important parameter in the process of scaling for the compartment fires.

Analysis on the Heat-resisting Coating of High Heat-resisting/Smoke Retardancy Fireproof Fabrics and Products (고내열/차연성 방화제품의 내열 코팅에 관한 연구)

  • Kim, Sang-Ryong;Kim, Sang-Wook;Lee, Do-Hyun;Min, Moon-Hong;Son, Hyun-Sik;Ahn, Seung-Guk;Bae, Jin-Hwa
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2011.03a
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    • pp.97-97
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    • 2011
  • 현대사회에서 화재에 의한 물적 피해는 물론 인적피해가 현저하게 증가하고 있으며 희생자의 사망원인이 종래에는 화재시 발생한 열에 의한 화상을 중심으로 하는 소사였지만, 최근에는 화염보다 독성가스로 인하여 사망하는 경우가 많아졌고, 희생자는 거의 화상을 확인할 수 없거나 화상자이더라도 혈액 중에서 일산화탄소를 중심으로 한 유독가스가 확인되기 때문에 이들 유독가스의 흡입으로 인하여 행동불능상태 이후 열의 영향으로 사망한 것으로 추정되는 사례가 증가하는 추세이다. 따라서 대규모 건축물에 있어서는 화재발생시 유독가스가 건물 전체로 연소 확대되는 것을 방지하기 위하여 넓은 면적을 일정한 면적으로 구획하거나 계단실 등과 다른 부분 또는 층별 등으로 구획하고 있으며, 국내의 방화구획은 크게 다른 층으로 화재전파를 막기 위한 층간 방화구획, 연소면적을 제한하기 위한 면적별 방화구획, 다른 용도로 인한 화재 위험성 감소를 위해 용도별 방화구획으로 3가지를 법에서 채택하고 있다. 방화구획은 방화문 또는 자동방화셔터를 이용하거나, 내부구조의 바닥, 벽, 각종 방화문으로 구획할 것을 정하고 있다.(피난방화규칙 제14조) 본 연구에서는 철제방화셔터 대체용으로 직물방화셔터용의 실리카 소재를 이용하여 제직한 직물에 내열/차연 기능성 코팅의 공정 조건을 변화하여 최종 방화시험을 거치기 전 내열성 테스트중 하나인 불꽃열 통과량 실험을 실행하여 방화 직물의 내열성을 비교 분석하였다. 이러한 결과를 토대로 본 연구는 고내열/차연성 방화 제품 기술을 개발하는데 필요한 연구를 수행하는데 목적이 있다.

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Effects of Ventilation Condition on the Fire Characteristics in Compartment Fires (Part II: Multi-dimensional Fire Dynamics) (구획화재에서 환기조건의 변화가 화재특성에 미치는 영향 (Part II: 다차원 화재거동))

  • Kim, Jong-Hyun;Ko, Gwon-Hyun;Park, Chung-Hwa;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.32-38
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    • 2010
  • Multi-dimensional fire dynamics were studied numerically with the change in ventilation conditions in a full-scale ISO 9705 room. Fire Dynamic Simulator (FDS) was used for the identical conditions conducted in previous experiments. Flow rate and doorway width were changed to create over-ventilated fire (OVF) and under-ventilated fire (UVF). From the numerical simulation, it was found that the internal flow pattern rotated in the opposite direction for the UVF relative to the OVF so that a portion of products recirculated to the inside of compartment. Significant change in flow pattern with ventilation conditions may affect changes in the complex process of CO and soot formation inside the compartment due to increase in the residence time of high-temperature products. The fire behavior in the UVF created complex 3D characteristics of species distribution as well as thermal and flow structures. In particular, additional burning near the side wall inside the compartment significantly affected the flow pattern and CO production. The distribution of CO inside the compartment was explained with 3D $O_2$ distribution and flow patterns. It was observed that gas sampling at local positions in the upper layer were insufficient to completely characterize the internal structure of the compartment fire.