• Title/Summary/Keyword: Fire extinguishing performance

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Extinguishing Characteristics of Liquid Pool Eire by Water Mist Containing Sodium Salt (나트륨 염이 첨가된 미분무수의 액체 pool fire소화특성)

  • Park Jae-Man;Shin Chang-Sub
    • Fire Science and Engineering
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    • v.19 no.3 s.59
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    • pp.13-19
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    • 2005
  • An experimental study is presented for extinguishing characteristics of liquid fuel fire by water mist containing sodium acetate trihydrate. To evaluate the extinguishing performance of water mist containing an additive, the evaporation characteristics of a water droplet on a heated surface was examined. The evaporation process was recorded by a charge-coupled-device camera. Also, small-scale extinguishing tests were conducted for n-heptane pool fire in ventilated space to measure flame temperature variation. The average evaporation rate of a water droplet containing an additive was lower than that of a pure water droplet at a given surface temperature due to the precipitation of salt in the liquid-film and change of surface tension. In case of using an additive, the flame temperature was lower than that of pure water at a given discharge pressure and it was because the momentum of a water droplet containing an additive was increased reducing flame size. And also dissociated metal atoms, sodium, were reacted as a scavenger of the major radical species OH^-,\;H^+$ which were generated for combustion process. Moreover, at a high pressure of 4MPa, the fire was extinguished through blowing effect as well as primary extinguishing mechanisms.

A study on practical use of remote automatic fire extinguishing equipment through test bed in road tunnel (도로터널용 원격 자동소화 설비의 test bed 적용을 통한 실용화 방안 연구)

  • Park, Sang-Heon;An, Sung-Joo;Kim, Jae-Hoon;Kim, Kyung-soo;Yun, Jun-Su;Yoo, Yong-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.6
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    • pp.837-847
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    • 2019
  • Korea's long underground roads are being promoted around the metropolitan city center to realize advanced transportation networks. Many disaster prevention facilities are applied to secure fire safety of the closed and long-distance underground roads. As the facility response and fire suppression subjects are unclear, additional human and material damages from fire spread are inevitable. Therefore, in this study, we developed a remote automatic fire extinguishing system that uses the fire extinguishing water inside the fire hydrant to monitor the CCTV in the management room and sprays it directly to the fire site through automatic control. The design application method was studied through the performance improvement that can be put into practical use.

Applicability of CO2 Extinguishing System for Ships (질식사고 방지용 CO2 소화설비의 선박 적용성)

  • Ha, Yeon Chul;Seo, Jung Kwan
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.4
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    • pp.294-300
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    • 2017
  • The offshore installations and ships are the structures most likely to be exposed to hazards such as hydrocarbon fire and/or explosion. Developing proactive measures to prevent the escalation of such events thus requires detailed knowledge of the related phenomena and their consequences. $CO_2$ extinguishing systems are extensively used for fire accidents of on-and offshore installations because of outstanding performance and low cost. There is, however, the risk of carbon dioxide system which enumerates many of the fatalities by suffocation associated with industrial fire protection requirements. Therefore, the aim of this study is to perform the prediction of fire suppression characteristics of the carbon dioxide system in realistic enclosed compartment area of ships and propose $CO_2$ extinguish fire fighting system for preventing suffocation accidents during fire fighting. According to CFD calculations, it can be observed and assessed that various fire profiles with $CO_2$ and $O_2$ mole fraction in the target enclosed compartment area are applicable within the proposed system. Additionally, the design of fire safety system of ships and offshore installations can utilize ventilation system and/or layout arrangement through the proposed system.

Evacuation Safety Evaluation for Apartment Complexes and Officetel under Floors (공동주택 및 오피스텔 지하층에 대한 피난 안전성 평가)

  • Hyeon-gwon Kang;Yong-Han Jeon
    • Journal of the Korea Safety Management & Science
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    • v.25 no.4
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    • pp.67-72
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    • 2023
  • Human and material damage can be reduced if the risk is evaluated by engineering analysis of fire combustion products, smoke concentration, and smoke movement speed in the event of a fire in apartment houses and officetels. In this study, a lot of research on related safety evaluation in the basement needs to be studied and reflected in design, so experimental research was conducted to analyze the flow of smoke through computer simulation and provide analysis data through evacuation safety evaluation. First of all, the five-story underground parking lot subject to simulation has a large floor area, which is advantageous for improving evacuation safety performance, but it uses temperature detectors to increase detection time and fire spread speed. Second, it was analyzed that the evacuation time at all evacuation ports did not exceed the evacuation time, and as the time from the start of evacuation to the evacuation time was 216.9% compared to the travel time, it was evaluated that the safety performance of the evacuation was secured. Third, the above simulation results are a comprehensive safety evaluation based on the non-operation of fire extinguishing facilities in the fire room to increase safety, which means that smoother evacuation safety performance can be secured by linking fire extinguishing facilities.

A Study on the Performance Prediction of Fire Extinguish System in Aircraft Engine Bay (항공기 엔진베이 내 소화장치 성능예측을 위한 연구)

  • Park, Young-Ha;Kim, Hyung-Sik;Kim, Jin-Han;Cho, Soo-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.8
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    • pp.718-725
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    • 2012
  • Fuel or oil which is leaked into the aircraft engine bay can make a fire when it is contacted to the engine surface of hot temperature. In order to avoid fire, the fire extinguish system should be designed so that the extinguishing agent is quickly injected and its concentration keeps higher in the fire protection region. FAA requires that the extinguishing agent injected within the fire protection region should be sustained longer than 0.5 second on keeping a higher concentration than 6%. For developing a fire protection system satisfying the FAA regulation, numerical and experimental studies for the injection time and the concentration of the extinguishing agent were conducted. These results showed similar trend for the injection time or concentration, but the data acquisition was delayed due to the response of the sensors in the experiment.

Development of Droplet Sizing Technique in Spay Flow (분무유동에서 입경 계측기법의 개발)

  • Yang, Chang-Jo
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.1
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    • pp.67-73
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    • 2007
  • Recently, fire extinguishing systems based on water mists have been attracting public attentions in marine engineering. Performance of fire extinguishing systems is very strongly influenced by the size and distribution of spayed water mists. Therefore, the present study has developed droplet analyzing method based on image processing. The morphological technique based on partial curvature information of pre-processed images with relaxation method was adopted for recognition and separation of overlapped particles. Tested results showed that the present method may be reliable for the analysis of the size and distribution of droplets in spray flow of fire extinguishing systems based water mists.

A Numerical Study to Analyze Safety of Pressure Leakage Monitoring System of Gas Extinguishing Agent (가스소화약제 압력누기감시장치의 안전성 분석을 위한 수치적 연구)

  • Go, A-Ra;Lim, Dong-Oh;Son, Bong-Sei
    • Fire Science and Engineering
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    • v.30 no.4
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    • pp.103-110
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    • 2016
  • While the demand for the gas system fire extinguishers increases every year, there are insufficient safety measures for assessing the extinguishing performance, such as system safety and reliability in the preparation of increasing demand, which has emerged as a social problem. One of the most critical causes of accidents occurring with the gas extinguishing system is pressure leakage from the extinguishing agent storage container. This is considered to be one of the critical factors on which the success of fire suppression depends. In this study, its safety measure was studied, Because it was deemed urgently necessary. The newly developed pressure leakage monitoring system is a system monitoring storage condition, pressure, leakage and discharge of the storage container related to agent concentration, which is one of the critical factors for fire suppression. This was developed to be applicable to the $CO_2$ and HFC-23 systems. Therefore, for structural safety analysis, the safety performance was verified by the fluid structure coupling analysis of the safety problems that may occur when the pressure leakage monitoring system is applied to the gas fire extinguisher. For analysis programs, the FloEFD program from Mentor Graphics was used for computational fluid dynamics analysis and ABAQUS from Dassault Systems was used for structural analysis. From the result of numerical analysis, the structure of $CO_2$ did not develop plastic deformation and its safety was verified. However, plastic deformation and deviation issue occurred with the HFC-23 monitoring system and therefore verified the structural safety of pressure leakage monitoring system by data obtained from redesigning and adjusting the condition of numerical interpretation three times.

The Seismic Design of Water Extinguishing Piping Systems for Equivalent Static Analysis Method (등가정적해석법에 의한 수계 파이프 시스템의 내진설계)

  • Lee, Dong-Myung
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.100-105
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    • 2012
  • In this study, seismic design in pipeline of pressurized water supply system of water extinguishing system has been carried out. This study described a generation of artificial earthquake wave compatible with seismic design spectrum, and also determined equivalent static loads to analyzed the response spectra acceleration by the simulated earthquake motion. This study constructed powerful engineering base for seismic design, and presented equivalent static analysis method for seismic design of water and gas extinguishing piping system. Also, this study readied basis that can apply seismic design and performance estimation of fire fighting system as well as pipeline of water extinguishing system from result of this research. Hereafter, if additional research by earthquake magnitude and ground kind is approached, reliance elevation, safety raising and performance based design of fire fighting system see to achieve.