• Title/Summary/Keyword: effect of fire

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Safety Evaluation of Mountain Slopes Considering the Effect of Forest Fire (산불의 영향을 고려한 산지사면의 안정성 평가)

  • Kim, Jong-Min;Chung, Bong-Hoon;Choi, Joon-Sung;Park, Duk-Keun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.1 s.12
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    • pp.57-64
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    • 2004
  • Recent abnormal weather condition and accompanying increase in forest fire require more study on the effect of forest fire on the stability of mountain slopes. The aims of this paper are to investigate how destroy of trees caused by forest fire influences the stability of mountain slopes and to propose a safety evaluation method for mountain slopes considering the effect of forest fire, in order to minimize the expected damage due to forest fire. To accomplish this aim, the effects of forest fire on the stability of mountain slopes are analyzed in quantitative way, and a slope stability chart is proposed as a result.

Effect of Rack Compartment using Barriers on Reducing the Fire Spread (차단막에 의한 랙크 구획화가 화재확산 저감에 미치는 영향)

  • Cho, Gyu-Hwan;Yeo, In-Hwan
    • Fire Science and Engineering
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    • v.32 no.1
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    • pp.66-75
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    • 2018
  • A barrier installed within a rack plays a significant role in delaying the initial spread of fire but it can be an obstacle to a ceiling-type sprinkler installed for extinguishing fires and for supplying fire extinguishing water. An in-rack sprinkler and a barrier can be applied at the same time, but a study on a barrier's ability to delay fire spread or its effect on the in-rack sprinkler is needed. Accordingly, this study examined the effect of a barrier on the delay of fire spread and the in-rack sprinkler according to installation conditions through the reduced scale fire test. As a result, the delay in fire spread increased more than four times when a horizontal barrier and a vertical barrier were installed at the same time. The temperature was also increased two to three times with the compartment, resulting in the early operation of the in-rack sprinkler.

The Effect of Safety Education Satisfaction of Apartment Residents and Application of Fire Protection Plan on Fire Safety Awareness (아파트 거주자의 안전교육 만족도와 소방계획서의 활용성이 화재안전의식에 미치는 영향)

  • Kim, Sang-Sig;Kong, Ha-Sung
    • Fire Science and Engineering
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    • v.34 no.1
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    • pp.103-114
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    • 2020
  • The purpose of this study is to investigate the effect of apartment residents' safety education satisfaction and the application of fire protection plans on fire safety awareness. The analysis results are as follows. First, the low levels of satisfaction with safety education content had a negative effect on anxiety about fire safety. This means that apartment residents' low levels of interest or participation in education affected their safety awareness, which prevented them from securing safety from fire. It is necessary for control staff to have a positive impact on their educational satisfaction via the learning support information system, among others, in order to create a satisfying education and safety culture. Second, competence in the execution of firefighting plans had a positive effect on fire safety awareness. These results indicate that apartment residents do not have the opportunity to access the education and training necessary for safety, nor the legal responsibility to complete mandatory safety education, which leads to their lack of safety awareness. Therefore, the control staff need to raise awareness of fire safety and the importance of participating in safety education among apartment residents by strengthening and activating the execution of firefighting plans in order to ensure safe living. Third, the competency of the firefighting plans moderated the effects of apartment residents' educational satisfaction on their awareness of fire safety.

Evaluation of the Radiant Heat Effects according to the Change of Wind Velocity in Forest Fire by using WFDS (WFDS를 이용한 풍속에 따른 산림화재 복사열 강도 평가)

  • Song, Dong-Woo;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.27 no.3
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    • pp.1-7
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    • 2013
  • The wildland fire intensity and scale are getting bigger owing to climate change in the world. In the case of domestic, the forest is distributed over approximately 63.7 % of country and the main facilities like a industrial facility or gas facility abuts onto it. Therefore there is potential that the wildland fire is developed to a large-scale disaster. In this study, the effect distances of the radiant heat flux from the crown fire are analysed according to the change of wind velocity. The safety criteria concerning the radiant heat flux to influence on the surrounding were researched to analyse the effect distances. The criteria of radiant heat flux were chosen $5kW/m^2$, $12.5kW/m^2$, $37.5kW/m^2$. WFDS, which is an extension of NIST's Fire Dynamics Simulator, was used to consequence analysis of the forest fire. In order to apply the analysis conditions, it is researched the forest conditions that is generally distributed in domestic region. As the result, the maximum effect distances by radiant heat were showed at the horizontal and vertical direction. When the wind velocity varied from 0 to 10 m/s, the maximum effect distance increased as the wind velocity increases. Interesting point is that the maximum effect distance were shown at the wind velocity of 8 m/s. The maximum effect distance was decreased according as the fuel moisture of trees increase. This study can contribute to analyse quantitative risk about the damage effect of the surrounding facilities caused by wildland fire.

Changes in Fire Characteristics according to the Distance Between the Fire Source and Sidewall in a Reduced-Scale Compartment (축소 구획실에서 화원과 측벽의 거리에 따른 화재특성 변화)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.50-59
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    • 2019
  • Experimental and numerical studies on the fire characteristics according to the distance between the fire source and sidewall under the over-ventilated fire conditions. A 1/3 reduced ISO 9705 room was constructed and spruce wood cribs were used as fuel. Fire Dynamics Simulator (FDS) was used for fire simulations to understand the phenomenon inside the compartment. As a result, the mass loss rate and heat release rate were increased due to the thermal feedback effect of the wall in the compartment fire compared to the open fire. As the distance between the fire source and sidewall was reduced, the major fire characteristics, such as maximum mass loss rate, heat release rate, fire growth rate, temperature, and heat flux, were increased despite the limitations of air entrainment into the flame. In particular, a significant change in these physical quantities was observed for the case of a fire source against the sidewall. In addition, the vertical distribution of temperature was changed considerably due to a change in the flow structure inside the compartment according to the distance between the fire source and sidewall.

Effect of Spray Angle of Water Mist Nozzle on Temperature Field of Compartment Fire (물분무노즐의 분사각이 화재실 내부의 온도장에 미치는 영향)

  • 김성찬;유홍선;박현태;방기영
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.28-33
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    • 2003
  • The present study investigates the effect of injection angle of water mist on fire suppression characteristics by numerical simulation. In order to validate the temperature field by numerical simulation, the predicted results are compared with experimental data. It shows that the temperature difference between measurements and predictions are within $10^{\circ}C$. Numerical simulations of fire suppression are performed for 4 different injection angle($60^{\circ}$, $90^{\circ}$, $^120{\circ}$, and $180^{\circ}$). The global mean temperature over the fire compartment decrease with increasing of spray angle. The result shows that the heat transfer between droplets and gas phase are enhanced with the increasing of spray angle. Near the fire source, temperature field by the wide spray angle is slightly higher than that of narrow injection angle because of direct cooling of fire source.

Effect of Spray Angle of Water Mist Nozzle on Temperature Field of Compartment Fire (물분무노즐의 분사각이 화재실 내부의 온도장에 미치는 영향)

  • Kim, Sung-Chan;Ryou, Hong-Sun;Park, Hyun-Tae;Bang, Ki-Young
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1703-1708
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    • 2003
  • The present study investigates the effect of injection angle of water mist on fire suppression characteristics by numerical simulation. In order to validate the temperature field by numerical simulation, the predicted results are compared with experimental data. It shows that the temperature difference between measurements and predictions are within $10^{\circ}C$ Numerical simulations of fire suppression are performed for 4 different injection angle($60^{\circ}$, $90^{\circ}$, $120^{\circ}$, and $180^{\circ}$). The grobal mean temperature over the fire compartment decrease with increasing of spray angle. The result shows that the heat transfer between droplets and gas phase are enhaced with the increasing of spray angle. Near the fire source, temperature field by the wide spray angle is slightly higher than that of narrow injection angle because of direct cooling of fire source.

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Fire Mitigation by Partitioning a Sodium Loop Building (화재완화를 위한 소듐 루프 건물의 구획화)

  • 김병호;권상운;정경채;김광락;황성태
    • Journal of the Korean Society of Safety
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    • v.13 no.3
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    • pp.32-44
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    • 1998
  • Analysis on the study for the sodium fire mitigation was carried out using the CONTAIN-LMR code. Sodium loop building was partitioned into the many cells, in which the safety venting systems were installed for the purpose of improving the sodium fire safety and minimizing its effect on the sodium loop building. The effects of sodium fire on sodium loop building partitioned into the many cells and not partitioned were investigated. The peak pressure and temperature of each cell accompanied by sodium fire in sodium loop building partitioned were lower than those of sodium loop building not partitioned. In the case of partitioning sodium loop building, the pressures, temperatures and aerosols into cells were transferred through propagation path of CONTAIN-LMR sodium fire model simulated by this study, and the effect of sodium spray fire on sodium loop building was mitigated by partitioning building. In addition, the excessive rise of pressure into cells was prevented by installing the over-pressure exhaust valve and under-pressure exhaust valve on the flow path between cells.

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The Influence of Zoning at Shafts of Super-tall Buildings on the Stack Effect and Stairwell Pressurization (초고층건물 샤프트의 수직구획이 연돌효과 및 급기가압 성능에 미치는 영향)

  • Kim, Beom-Kyue;Kim, Hak-Jung;Yeo, Yong-Ju;Leem, Chae-Hyun;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.92-98
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    • 2012
  • This study analyzed the effect of zoning on the distribution of pressure differentials caused by stack effect and air pressurization in a center core type of 80 story super-tall building. The results showed that maximum pressure difference more than 250 Pa can be generated by stack effect without zoning. Zoning of stairwell only resulted in 10 Pa reduction of maximum pressure difference, however, zoning of both stairwell and EV shaft especially at the same floor revealed 50 % reduction in stack effect. It was also analysed that the minimum required air flow rate occurred when the stairwell temperature reached 50 % of temperature difference between indoor and outdoor.