• 제목/요약/키워드: Fire Heat

검색결과 1,621건 처리시간 0.031초

폼 분무 노즐 방사 분포 및 폼의 열적 특성 연구 (Thermal Characteristics of Foams and Discharge of Fire-Protection Foam Spray Nozzle)

  • 김홍식;김윤제
    • 대한기계학회논문집B
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    • 제29권1호
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    • pp.151-158
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    • 2005
  • A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

철근콘크리트조 화재건물의 부재내부온도분포 추정에 관한 연구 (A Study on Calculating the Temperature Distributions in the Concrete members of Reinforced Concrete Building with Fire Damage)

  • 오창희
    • 한국화재소방학회논문지
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    • 제1권1호
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    • pp.11-18
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    • 1987
  • This study is for calculating the equation of the inner temperature in the concrete, mainly by the theory or heat conduction in the solid. The results are as follow ; 1. The equation of the Fourier's heat diffusion is used formally to get the distribution of inner temperature or the concrete members, and this is programed by using the computer. 2. As study in the past, heat constant of concrete is calculated for function of temperature described recommendation heat constant value in comparison with the existing inner heating experimental result.

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도막상태에 따른 열감지기의 감온특성에 관한 시험, 연구 (A REPORT ON THERMAL LAG OF PAINTED HEAT DETECTORS)

  • 이복영;유인호
    • 방재기술
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    • 통권14호
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    • pp.18-33
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    • 1993
  • This report is announced about thermal lag of painted heat detectors. Thermal lag is forecast result from painting the part of heat receiving. It is delayed responsive time to assume fire fighting, escape. Test is simulated that heat detector is painted by synthetic resin emulsion paint according to the circumstance of installation. Painting method, number, thick etc is determined by research worker based on the popular idea.

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개구부가 있는 밀폐공간내 화재의 복합열전달 및 연소가스 분석에 관한 연구 (A Study on the Combined Heat Transfer and Analysis Fire Induced Combustion Gas in a partially Open Enclosure)

  • 박찬국;추병길;김철
    • 한국화재소방학회논문지
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    • 제11권1호
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    • pp.21-35
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    • 1997
  • The natural convection and combined heat transfer induced by fire in a rectangular enclosure is numerically studied. The model for this numerical analysis is partially opened right wall. The solution procedure includes the standard k-$\varepsilon$ model for turbulent flow and the discrete ordinates method (DOM) is used for the calculation of radiative heat transfer equation. In numerical study, SIMPLE algorithm is applied for fluid flow analysis, and the investigations of combustion gas induced by fire is performed by FAST model of HAZARD I program. In this study, numerical simulation on the combined naturnal convection and radiation is carried out in a partial enclosure filled with absorbed-emitted gray media, but is not considered scattering problem. The streamlines, isothermal lines, average radiation intensity and kinetic energy are compared the results of pure convection with those of the combined convection-radiation, the combined heat transfer. Comparing the results of pure convection with those of the combined convection-radiation, the combined heat transfer analysis shows the stronger circulation than those of the pure convection. Three different locations of heat source are considered to observe the effect of heat source location on the heat transfer phenomena. As the results, the circulation and the heat transfer in the left region from heating block are much more influenced than those in the right region. It is also founded that the radiation effect cannot be neglected in analyzing the building in fire. And as the results of combustion gas analysis from FAST model, it is found that O2 concentration is decreased according to time. While CO and CO2 concentration are rapidly increased in the beginning(about 100sec), but slowly decreased from that time on.

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서점의 적재가연물의 연소특성에 관한 실험적 연구 (Experimental Study on Combustion Characteristics of Live Fire Load in a Bookstore)

  • 남동군
    • 한국화재소방학회논문지
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    • 제25권5호
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    • pp.47-53
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    • 2011
  • 건축물 적재가연물은 종류 및 양 등의 특성에 따라 화재지속시간과 화재규모 등에 크게 기여한다. 서점은 다른 건축용도보다 가연물이 다량 적재되어 있으므로 화재발생시 화재위험성이 클 가능성이 있다. 그러나 한편으로는 서점 내부의 서적은 연소하면 탄화층이 형성되고 적재가연물량에 비해 노출표면적이 작기 때문에 화재시 열분해가스의 생성이 작을 가능성도 있다. 이러한 가능성을 다양한 실험을 통해 파악하여 서점의 화재안전설계에 합리적으로 반영할 필요가 있다. 따라서 본 연구에서는 서점의 성능위주설계에 활용하기 위하여 적재가연물을 재현한 시험체를 가열로에 넣고 ISO834-1:1999 표준가열곡선에 따라 가열하는 일련의 실험을 실행하였다. 이 실험 결과를 바탕으로 서점의 적재가연물의 연소발열성상을 파악하고 성능위주설계에 필요한 연소속도 및 열방출률 등을 제시하였다.

화재하중에 따른 구획화재 실험 연구 (The Study on Compartment Fire Experiment According to Fire Load)

  • 권오상;김흥열
    • 한국화재소방학회논문지
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    • 제31권6호
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    • pp.16-22
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    • 2017
  • 국내에서는 복잡해지고 다양해지고 있는 건축물에서의 화재위험에 대응하기 위해 성능기반 화재안전 설계가 논의되고 있지만, 건축물에서의 다양한 인자들에 의한 화재특성의 에측의 어려움으로 인하여 성능기반 화재안전 설계의 도입이 제한되고 있다. 본 연구에서는 뉴질랜드에서 제시하고 있는 화재위험도별 화재하중 값의 실대형 화재실험을 통해 성능기반 설계 도입을 위한 기준 방향 설정 및 기초 자료로 사용하고자 하였다. 실대형 화재실험은 10 MW급의 실대형 칼로리미터에서 $0.8(L){\times}2.0(H)m$의 단일 개구부를 포함하고 있는 $2.4(L){\times}3.6(W){\times}2.4(H)m$ 크기의 시험체 틀의 내부에 목재 크립을 화재하중에 따라 배치시켜, 목재 크립이 전소할 때 까지 진행하였다. 화재실험에서 열방출률의 변화는 목재 크립에 화염이 착화 된 후 외부로 출화되는 약 90초 이후부터 급격히 증가하였으며, 위험도 레벨 1에서는 최대 4743.4 kW의 열발출률이 실험시작 후 244 초에 측정되었고 위험도 레벨 2에서는 5050.9 kW의 최대 열방출률이 497 초에 측정되었다. 또한 위험도 레벨 3에서는 최대 열방출률이 4446.9 kW로 실험시작 677 초에 측정되었다.

퍼니쳐 칼로리미터를 이용한 화재 특성 평가 (Fire Characteristics Evaluation by Using Furniture Calorimeter)

  • 권오상;유용호;김흥열
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.44-47
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    • 2008
  • This paper evaluated the fire characteristics by using furniture calorimeter. Fire property assessment using the furniture calorimeter showed that the heat release rate is maximum 1,600 kW, maximum CO is 0.261%, maximum CO2 is 2.597%, while for the sofa for one person, the maximum heat release rate is approx. 531.5 kW, max. CO is 0.102%, and max. CO2 is 1.011%.

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목재 가연물의 두께에 따른 화염연소와 훈소상태에서의 화재특성 (Fire Characteristics of Flaming and Smoldering Combustion of Wood Combustibles Considering Thickness)

  • 김성찬;남동군
    • 한국화재소방학회논문지
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    • 제29권4호
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    • pp.67-72
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    • 2015
  • 본 연구는 콘칼로리미터 실험을 통해 건축물 마감재와 가구소재로 널리 적용되는 목재 가공품의 화염연소와 훈소시 화재특성을 파악하고자 한다. 시험대상 목재 가연물은 MDF, 합판, 칩보드이며 $50kW/m^2$의 복사열유속을 시편에 가하여 점화를 유도하였다. 실험과정에서 화재특성을 나타내는 발열량, 연소가스 생성율, 유효연소율 등의 주요 인자를 가연물의 두께에 따라 정량화하였다. 실험결과 초기 평면방향의 화염전파와 후기 시편의 관통에 의한 화재확대로 인해 단위면적당 발열량에 대한 두 개의 피크점이 관측되었다. 화염연소시의 질량감소율이 훈소시에 비해 5배 이상 높게 나타난 반면에 훈소과정에서 CO 생성율은 화염연소에 비해 10배 이상 높게 측정되어 훈소시 높은 독성가스 생성율을 보였다. 본 연구는 목재 가연물의 화재성상을 이해하고 화재해석을 위한 물성자료로 활용될 수 있다.

탄소재료의 적용 방법에 따른 파티클 보드의 연소 특성 (Evaluation of Fire Characteristics for Particle-board with Exfoliated Graphite Nanoplatelets Added)

  • 서현정;조정민;황욱;이민철
    • 한국연소학회지
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    • 제22권4호
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    • pp.1-8
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    • 2017
  • This study was conducted to evaluate the fire retardant performance of exfoliated graphite nanoplatelets (xGnP) applied for particleboard. This work measured heat release rate(HRR), total heat release(THR) and smoke production rate(SPR) of xGnP added particleboard, using cone calorimeter to assess its fire characteristics according to the KS F ISO 5660-1 standard code. Heat release rates of all specimens treated by xGnP were less than the $200kW/m^2$ for a total experiment period of five minutes. Heat release rates of the specimens coated with xGnP were lower than those of the specimens made by mixing wood particles with xGnP directly. Meanwhile, the total heat release rates of xGnP coated specimen maintained quite lower level than the uncoated so the xGnP coating were effective in improving the fire retardant performance of particleboard. However, the smoke emission peaking problem at the initial combustion period, which was caused by adding base coating materials, should be resolved for further satisfaction as a fire retardant materials.

연소로의 화염분포가 보일러 관로에 미치는 영향에 관한 연구 (A Study on the Imfluence of the Pipe Line of Boiler for Flame Distribution of Combustion Furnace)

  • 조동현
    • 수산해양교육연구
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    • 제26권6호
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    • pp.1435-1441
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    • 2014
  • The fire took place in the synthetic heat transfer fluid boiler used in production process of medium density fiberboard. This study investigated pressure distribution of the first, second and third passes and the temperature in the fire burner. The boiler's internal fluid is unsteady due to the out of order inverter. As the operation continues, the flame's flow and speed are unsteady. The synthetic heat transfer fluid leak spouted about 120kg/min in the form of vapor in the early period of the fire. The flame extended to the second and third passes. The highest temperature of the second and third pass is $1059^{\circ}C$ and $1007^{\circ}C$, respectively. The synthetic heat transfer fluid spouted through the cracked part of the fire box in the first pass and accumulated on the turn table. Therefore, it is expected that the temperature of the interior of the fire box is above $1200^{\circ}C$. The temperature of the burner rises to a maximum level several times in a short period. On account of that, several explosions occur in the fire burner. Pressure distribution at steady state in combustion furnace is 2~5mAq and pressure distribution at inverter under fault condition in combustion furnace is 10~-53mAq. The decrement of coil thickness measurement for synthetic heat transfer fluid boiler is 0~5mm.