• Title/Summary/Keyword: 열방출률

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A Study on the Characteristics of FDS Heat Release Rate Predictions for Fire involving Solid Combustible Materials in a Closed Compartment (밀폐된 구획 내 복합소재 고체 가연물의 연소시 열방출률의 FDS 예측 특성)

  • Hong, Ter-Ki;Roh, Beom-Seok;Park, Seul-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.349-356
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    • 2020
  • The heat release rate (HRR) and fire growth rate of fire for the solid combustibles consisting of multi-materials was measured through the ISO 9705 room corner test, and the computational analysis in a closed compartment was performed to simulate a fire using the heat release rate prediction model provided by a Fire Dynamics Simulator (FDS). The method of predicting the heat release rate provided by the FDS was divided into a simple model and a pyrolysis model. Each model was applied and computational analysis was performed under the same conditions. As the solid combustible consisting of multi-materials, a cinema chair composed mostly of PU foam, PP, and steel was selected. The simple model was over-predicted compared to the predicted heat release rate and fire growth rate using the pyrolysis model in a closed compartment.

A study of the HRR and fire propagation phenomena for the fire safety design of deep road tunnel (대심도터널 화재 안전 설계를 위한 승용차의 열방출률 및 화재전파 특성에 관한 연구)

  • Yoo, Yong-Ho;Kweon, Oh-Sang
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.4
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    • pp.321-328
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    • 2010
  • The study performed an actual fire experiment in order to propose the heat release rate of automobile that is the most basic architectural element for the fire safety design in a tunnel, whose importance has been recognized as the underground traffic tunnels are planned in Korean metropolitan cities. The heat release rate of a van is measured by the large scale calorimeter, in which the law of oxygen consumption is applied, and the fire expansion characteristics in a tunnel by placing two passenger cars nearby one another in the tunnel. As the results, the heat release rate of the van was revealed to be 5.9 MW, and carbon monoxide was emitted 482 ppm at a maximum. In case of two passenger car experiment for the fire expansion characteristics, the adjacent car was ignited about 3 minutes 30 seconds after the fire occurrence, and the complete fire was developed after 15 minutes. The maximum heat release was 9 MW. The results from the actual fire experiment can be an important input data for future quantitative analysis as well as an element applicable to a tunnel disaster preventive equipment design.

Numerical Analysis of the Effects of Droplets Characteristics of Water Spray on Fire Suppression (물 분무 액적 특성이 화재진압에 미치는 영향에 대한 수치해석)

  • Lee, Jaiho
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.1-8
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    • 2019
  • In this study, the effects of the characteristics of droplets of water spray on suppression of fire were analyzed numerically using fire dynamics simulator (FDS) 6.5.2. Additionally, the fire suppression characteristics by the water spray nozzle, including the extinguishing coefficient (EC), droplet size distribution function (SDF), median volumetric diameter (MVD), and droplets per second (DPS), were evaluated in terms of the decreasing normalized heat release rate (HRR) curve and cooling time. It was observed that with increase in the EC, the normalized HRR curve decreased rapidly, and the changing MVD affected the suppression of fire. In case of mono-disperse, the normalized HRR curve decreased slowly with the increase in DPS. On the contrary, in case of multi-disperse, the normalized HRR curve decreased rapidly even with a small increase in DPS.

Characteristics of Heat Release Rate Predictions of Fire by a Fire Dynamics Simulator for Solid Combustible Materials (복합소재 고체 가연물의 화재 시 발생되는 열방출률의 FDS 예측 특성)

  • Nam, Dong-Gun;Hong, Ter-Ki;Ryu, Myung-Ho;Park, Seul-Hyun
    • Fire Science and Engineering
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    • v.34 no.4
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    • pp.22-28
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    • 2020
  • The heat release rate (HRR) of fire for solid combustibles, consisting of multi-materials, was measured using the ISO 9705 room corner test, and a computational analysis was conducted to simulate the fire using an HRR prediction model that was provided by a fire dynamics simulator (FDS). As the solid combustible consisted of multi-materials, a cinema chair composed primarily of PU foam, PP, and steel was employed. The method for predicting the HRR provided by the FDS can be categorized into a simple model and a pyrolysis model. Because each model was applied and computational analysis was conducted under the same conditions, the HRR and fire growth rate predicted by the pyrolysis model had good agreement with the results obtained using the ISO 9705 room corner test.

Experimental Study on the Effect of Flow around Solid Combustibles and Thermal Thickness on Heat Release Rate Characteristics (고체 가연물 주위의 유동과 열적 두께의 변화가 열방출률 특성에 미치는 영향에 관한 실험적 연구)

  • Hong, Ter-Ki;Seo, Dong-Pyo;Park, Seul-Hyun
    • Fire Science and Engineering
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    • v.34 no.3
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    • pp.28-34
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    • 2020
  • In this study, an ISO 5660-1 cone calorimeter experiment was conducted to examine the effects of changes in flow and thermal thickness around solid combustibles on heat release rate characteristics. Polymethyl methacrylate (PMMA) is a solid combustible material that does not generate char during the combustion reaction. Hence, it was selected for the experiment, and the thermal penetration depth was calculated to distinguish the thermal thickness of PMMA. Furthermore, the thermal decomposition characteristics were analyzed by measuring the heat release rate measured during the combustion of PMMA. This was performed after generating the forced flow around the combustibles by setting the duct flow of the cone calorimeter to 12, 24, and 40 L/s. The results confirmed that the thermal release rate of the thermally thin combustible material was not significantly affected by the change in the surrounding flow. Hence, the thermally thick combustible material was significantly affected by the change in the flow rate.

Comparison with Combustion Properties of Wood-Plastic Composites (Wood-Plastic Composite의 연소특성 비교)

  • Song, Young-Ho;Shin, Baek-Woo;Lee, Dong-Ho;Chung, Kook-Sam
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2010.10a
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    • pp.251-256
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    • 2010
  • 주거 건축 및 가구산업의 자재로써 합성목재(Wood-Plastic Composites)는 점차 각광받고 있다. 본 연구에서는 합성목재의 연소특성을 살펴보기 위하여 한계산소지수 측정(ASTM D2863) 및 콘칼로리미터 시험(ISO 5660-1)을 실시하였으며 또한 일반목재인 적송(red pine)과 방부 처리를 한 방부목에 대하여도 동일한 시험을 통하여 합성목재와 연소특성을 비교 검토하였다. 한계산소지수 측정결과 합성목재가 적송 및 방부목에 비해 가장 낮게 측정되었다. 콘칼로리미터 시험결과 합성목재의 열방출률값이 가장 빨리 피크치에 도달하였고 점차적으로 감소하였다. 합성목재의 최대 열방출률 값 및 평균 열방출률 값은 적송 및 방부목에 비해 가장 높게 나타났으며 총 방출열량 또한 가장 높게 나타났다.

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A Study on Combustion Characteristics of Wood-Plastic Composites (합성목재의 연소특성에 관한 연구)

  • Shin, Baeg-Woo;Song, Young-Ho;Rie, Dong-Ho;Chung, Kook-Sam
    • Fire Science and Engineering
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    • v.24 no.6
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    • pp.120-125
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    • 2010
  • Wood-Plastic Composites (WPCs) are one of spotlighting materials for the residential construction and the industry for furniture. At this study, the limiting oxygen index (LOI) was measured by ASTM D 2863 and the cone calorimeter test was done by ISO 5660-1 to find the combustion characteristics of WPCs. In addition, the identical test was implemented to compare the combustion characteristics between the red pine and the antiseptic wood. The result of LOI measurement showed that the LOI of WPCs was lower than that of red pine or antiseptic wood. The cone calorimeter test showed that the heat release rate (HRR) of WPCs was the highest and the Peak HRR as well as the average HRR and total heat release of WPCs was higher than those of red pine or antiseptized wood

Thermal Characteristics Of Car Interior Materials Using Cone Calorimeter (콘칼로리미터를 이용한 자동차 내장재의 열적 특성)

  • Kim, Young-Tak;Kim, Hae-Rim;Park, Young-Joo;Lee, Hae-Pyeong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2009.04a
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    • pp.557-563
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    • 2009
  • FMVSS 302 수평 연소 시험법을 통과한 자동차 내장재의 열적 특성을 평가하기 위해서 콘칼로미터를 이용하여 시험을 수행하였다. 화재 위험과 관련된 착화시간(time to ignition), 열방출률(heat release rate), 질량감소율(specific mass loss rate), 감쇠계수(extinction coefficient) 그리고 연기요소(smoke factor)와 같은 여러 가지 요소들을 분석하였다. 최대 열방출률값은 시험편에 따라 232${\sim}$635kW/$m^2$으로 큰 편차를 보였으며, 연기요소 또한 99${\sim}$551MW/$m^2$로 큰 편차를 보였다. 보조매트의 최대 열방출률은 다른 시험편에 비해서 상대적으로 낮은 값을 보였지만, 총연기 발생이 다른 시험편에 비해서 상당히 높았다. 따라서 최대 열방출률과 총 연기발생을 함께 고려한 연기요소값은 상대적으로 다른 시험편에 비해서 높게 나타났다.

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Combustion Characteristics and Thermal Properties for Wood Flour-High Density Polyethylene Composites (목분-고밀도폴리에틸렌 복합체의 연소성 및 열적특성)

  • Shin, Baeg-Woo;Chung, Kook-Sam
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.89-95
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    • 2012
  • In this study, we were manufactured wood flour-HDPE composites by modular co-rotating twin screw extruder with L/D ratio of 42. We was measured cone calorimeter test and thermogravimetric analysis (TGA) to find the combustion characteristics and thermal properties for wood flour-HDPE composites. We then evaluated the effect of three additive-type flame retardants on fire resistance performance. The cone calorimeter test showed that the heat release rate (HRR) of untreated composites was the highest Peak HRR ($446.6kW/m^2$) as well as Mean HRR ($185.5kW/m^2$). From the TGA, it was shown that composites added flame retardants began early thermal decomposition and improved thermal stability.

Characteristics of the Train Car Fire Curve (철도차량화재곡선의 특성 분석)

  • Lee, Duck-Hee;Park, Won-Hee;Jung, Woo-Sung;Kim, Chi-Hun
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2011.04a
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    • pp.106-111
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    • 2011
  • 철도차량의 화재 시 방출되는 열방출률 곡선은 철도터널 설계 시 방재규모를 결정하는 중요한 인자이다. 하지만 이 열방출률 곡선은 차량에서 발생할 수 있는 화원의 시나리오 및 터널복사나 주변유동과 같은 환경변화에 따라서 다른 특성을 가진다. 따라서 이를 포괄할 수 있도록 대표선도로 표준화된 화재곡선을 선정하여 터널의 설계화재로 사용하게 된다. 본 논문은 실물화재 시험 및 FDS를 이용한 철도차량 화재시뮬레이션과 ISO 9705 설비를 이용한 간단한 화재시험 등의 결과를 분석하여 플래시오버 전 후 단계에서 나타나는 철도차량의 화재곡선 특성을 분석하고 룸코너 시험설비를 이용하여 프리플래시오버 단계의 화재곡선 추정 방안을 제시하였다.

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