• Title, Summary, Keyword: pool fire

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On Basic Characteristics of A Pool Fire (Pool fire의 기본적 특성에 관하여)

  • 김명배
    • Fire Science and Engineering
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    • v.11 no.1
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    • pp.55-64
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    • 1997
  • Pool fire는 본격적인 화재연구의 시작과 더불어 그 구조 및 특성에 대한 연구가 지속적으로 수행되어 왔다. Pool fire는 복잡하고 취급하기 어려운 화재의 제문제들을 비교적 간단하게 다룰수 있게 하면서도 현실과 괴리되지 않는 형태를 가지는 가장 기본적인 형태의 화재로, 학문적 측면뿐 아니라 응용측면에서도 매우 유용한 결과 및 단서를 제공하여 왔다. 따라서, 본고에서는 pool fire의 특성을 화염기저(flame base)부근과 플륨(plume)부근으로 나누어 그 동안 발표되었던 연구결과를 정리하고, 화재 시뮬레이션을 위한 zone 모델기법의 가장 중요한 부분의 하나인 연기량 산정과 플륨해석이 어떤 형태로 연결되는 지를 설명하고자 한다.

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Combustion Characteristics of Pool and Whirl Fire on Methanol by Height of Fire Source using the Small Scale (화점높이 변화에 따른 메탄올의 소규모 Pool 및 Whirl Fire의 연소특성)

  • Park, Hyung-Ju
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.73-78
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    • 2012
  • This study is intended to understand flame behavior of pool and whirl fire by height of fire source. Liquid fuel was methanol which is used in many studies for pool and whirl fire. Size of vessel was $100{\times}100{\times}50$ and the vessel was made by stainless steel. Combustion time, mass loss rate, flame temperature, flame height and air entrainment rate from the outside to flame were measured, and flame behavior was visualized with video camera. Based on the experiment, it was found that combustion characteristics by height of fire source got a more effect on whirl fire than pool fire.

The Effects of Spray Characteristics of Water Mist on the Fire Suppression of Liquid Pool Fire (미분무수 분무특성이 액체연료 Pool 화염의 소화에 미치는 영향)

  • Oh, Sang-Youp;Kim, Ho-Young;Chung, Jin-Taek
    • 한국연소학회:학술대회논문집
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    • pp.215-221
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    • 2003
  • A series of experiments were conducted to study the effectiveness of the extinction of a liquid pool fire with two different water atomizing nozzles. Fire source is small-scale circular stainless steel pan of 120mm in diameter with the fuels of hexane and ethanol. K-type thermocouples were used to measure the flame and fuel temperature along the pool centerline and under fuel surface. A digital camera was used to visualize the process of the fire suppression. The experimental results show that water mist droplet size is $115{\sim}180{\mu}m$ with nozzle A and $130{\sim}190{\mu}m$ with nozzle B. The extinguishing time of pool fire was reduced with the increase of pressure. When water droplets are small, they do not reach the flame base since they may be deflected or evaporated by the fire plume. However, influence of flow rate is more important than droplet size on fire extinction. Among the fire extinction mechanisms, drop of flame temperature is superior to suffocation of O2 concentration.

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Combustion Characteristics of Pool Fire by Height of Fire Source (화점높이 변화에 따른 Pool Fire의 연소특성)

  • Park, Hyung-Ju;Cha, Jong-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4671-4676
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    • 2010
  • This study is intended to understand flame behavior of the pool fire by height of fire source. Liquid fuels were methanol and n-Heptane which are used in many studies of pool fire. Size of vessel was $100mm{\times}100mm{\times}50mm$ and the vessel was made by stainless steel. Combustion time, mass loss rate, flame temperature, flame height and air entrainment rate from the outside to flame were measured, and flame behavior was visualized with video camera. Based on the experiment, it was found that combustion characteristics of pool fire was decreased according to increase of height of fire source because entrainment volume of relative cold air was increased from the outside to flame.

Effects of Spray Characteristics of Water Mist on The Extinction of a Liquid Pool Fire (분무수 분무특성이 액체연료 Pool 화염의 소화에 미치는 영향)

  • Kim, Ho-Young;Oh, Sang-Youp;Chung, Jin-Taek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1591-1599
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    • 2004
  • A series of experiments were conducted to study the effectiveness of the extinction of a liquid pool fire with two different water atomizing nozzles. Fire source is a small-scale circular stainless steel pan of 120mm in diameter with the fuels of hexane and ethanol. K-type thermocouples were used to measure the flame and fuel temperature along the pool centerline and under fuel surface. A digital camera was used to visualize the process of the fire suppression. The experimental results show that water mist droplet size is l15∼180${\mu}{\textrm}{m}$ with nozzle A and 130∼190${\mu}{\textrm}{m}$ with nozzle B. The extinguishing time of pool fire was reduced with the increase of pressure. When water droplets are small, they do not reach the flame base since they may be deflected or evaporated by the fire plume. However, influence of flow rate is more important than droplet size on fire extinction. Among the fire extinction mechanisms, drop of flame temperature is superior to suffocation of $O_2$ concentration.

Comparative study of experimental equations on measurement of fire hight on pool fire (Pool fire에서의 화염의 높이 계산에 관한 실험식의 비교연구)

  • Hwang, Woon-Gi;Kwon, Chang-Hee
    • Journal of the Korea Safety Management and Science
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    • v.19 no.1
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    • pp.9-13
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    • 2017
  • In this study, the height of the flame required to estimate the heat flow path and flame spread in pool fire has been applied by the empirical formula, but it is calculated without applying the pressure and temperature parameters of the fire room. Until now, the height of the flame applied to pool fire was $l_F=0.235Q^{2/5}-1.02D$ in the Heskestad empirical formula, but accurate temperature calculation was not possible due to the temperature and pressure which are not influenced by the flame height. Therefore, applying the temperature and pressure around it can calculate the exact flame height, which can be applied to fire investigation and fire dynamics. The structure of the flame is divided into a continuous flame, an intermittent flame, and a buoyancy flame, but it is assumed that the flame height is calculated from the visual aspect to the intermittent flame region, and the temperature of the buoyancy flame is very low. The effect of heat of vaporization on the height of flame was investigated. The results showed that flame height was different according to the pressure and temperature around the fire room.

Characteristics of Water Spray for Extinguishment of Gasoline Pool Fire (가솔린 화재의 소화를 위한 수분무의 특성)

  • Jang, Yong-Jae;Kim, Myeong-Bae
    • 연구논문집
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    • pp.129-135
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    • 1995
  • This study discribes characteristics of water spray for extinguishment of gasoline pool fire. Experiments are carried out for the gasoline pool fire in a small tank with a diameter of 150mm and a height of 8mm. Droplet size, spray pressure, amount of water which reaches the flame base and velocity of water spray are measured to find extinguishment conditions and air entrainment due to the water spray is visualized. Critical conditions of water spray for extinguishment of gasoline pool fire is quantitatively shown.

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A Study on the Characteristics of Pool Fire (Pool 화재의 연소 특성에 관한 연구)

  • 오규형;나선종;이성은
    • Fire Science and Engineering
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    • v.18 no.3
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    • pp.39-44
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    • 2004
  • This study is intended to understand flame behavior of the pool fire. Liquid fuels were acetone, methanol, hexane and heptane which are used in many industries. Diameter of vessel was varied from 50 mm to 400 mm and the vessel was made by stainless steel and copper. Combustion time, temperature of vessel wall and heat flux of flame were measured, and flame behavior was visualized with video camera. Based on the experiment, it was found that the burning velocity and flame height was increased according to increase of vessel diameter, and vortex shedding frequency was inverse proportion to vessel diameter. And the characteristics of pool fire were affected by physical and chemical properties of liquid fuel and the vessel materials.

An Experimental Study on the Effect of Ventilation Velocity on the Burning Rate in Longitudinal Ventilation Tunnel Fires (종류식 배연 터널 화재시 배연속도가 연소율에 미치는 영향에 대한 실험적 연구)

  • Yang Seung-Shin;Ryou Hong-Sun;Choi Young-Ki;Kim Dong-Hyeon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.10
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    • pp.914-921
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    • 2005
  • In this study, the 1/20 reduced-scale experiment using Froude scaling were conducted to investigate the effect of longitudinal ventilation velocity on the burning rate in tunnel fires. The methanol pool fires with heat release rate ranging from 2.02 kW to 6.15 kW and the n-heptane pool fires with heat release rate ranging from 2.23 kW to 15.6 kW were used. The burning rate of fuel was obtained by measuring the fuel mass at the load cell. The temperature distributions were observed by K-type thermocouples in order to investigate smoke movement. The ventilation velocity in the tested tunnel was controlled by inverter of the wind tunnel. In methanol pool fire, the increase in ventilation velocity reduces the burning rate. On the contrary in n-heptane pool fire, the increase in ventilation velocity induces large burning rate. The reason for above conflicting phenomena lies on the difference of burning rate. In methanol pool fire, the cooling effect outweighs the supply effect of oxygen to fire plume, and in n-heptane pool vice versa.

Examination on Liquid Pool Fire Extinguishment Performance of Twin-fluid Nozzle (2유체노즐의 액체풀 화재 소화 성능에 대한 검토)

  • Jeong, Chan Seok;Lee, Chi Young
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.59-64
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    • 2017
  • In the present experimental study, the liquid pool fire extinguishment performance of twin-fluid nozzle was preliminarily examined. For the liquid pool fire, the ethanol of 1200 ml (volume) was prepared, and two kinds of air flow rate conditions (40 l/min and 70 l/min) were tested at the constant water flow rate condition of 632 ml/min. In the present experimental ranges, the fire extinguishment experiments were carried out using the twin-fluid nozzle and its spray characteristics (i.e., SMD (Sauter Mean Diameter) and flow distribution) were investigated. As a result, at the higher air flow rate, the liquid pool fire was extinguished quickly and successfully, which was discussed using the visualization and spray characteristics of twin-fluid nozzle. In addition, through the comparison with some of previous results, it was found that potentially, the twin-fluid nozzle can extinguish the liquid pool fire under the smaller water flow rate condition, as compared with the single-fluid nozzle.