• Title/Summary/Keyword: Fire-Heat

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

  • Kim, Hong-Sik;Kim, Youn-Jea
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.1 s.232
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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.

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

  • 오창희
    • Fire Science and Engineering
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    • v.1 no.1
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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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A REPORT ON THERMAL LAG OF PAINTED HEAT DETECTORS (도막상태에 따른 열감지기의 감온특성에 관한 시험, 연구)

  • Lee, Bok-Yeong;Yu, In-Ho
    • Fire Protection Technology
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    • s.14
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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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A Study on the Combined Heat Transfer and Analysis Fire Induced Combustion Gas in a partially Open Enclosure (개구부가 있는 밀폐공간내 화재의 복합열전달 및 연소가스 분석에 관한 연구)

  • Park, Chan-Kuk;Chu, Byeong-Gil;Kim, Cheol
    • Fire Science and Engineering
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    • v.11 no.1
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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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Experimental Study on Combustion Characteristics of Live Fire Load in a Bookstore (서점의 적재가연물의 연소특성에 관한 실험적 연구)

  • Nam, Dong-Gun
    • Fire Science and Engineering
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    • v.25 no.5
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    • pp.47-53
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    • 2011
  • Fire load in buildings greatly contribute to the time and scale of fire according to the type and quantity of the fire load. Because bookstores have a large quantity of fire load compared with other buildings which may lead to large scale fires, however, their heat release characteristics have been hardly investigated. In this study, to obtain the data applicable for the performance-based fire safety design of bookstores, the specimens representing stacked fire loads were heated in a furnace in compliance with the standard heating curve of ISO834-1:1999 to investigate their heat release characteristics. From the experiment result, the combustion velocity and heat release rate required for performancebased fire safety designs are obtained.

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

  • Kweon, Oh-Sang;Kim, Heung-Youl
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.16-22
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    • 2017
  • In Korea, performance-based fire safety designs are being discussed to deal with the various risks of fire in complex and diverse types of structure. However, performance-based fire safety designs are not actively employed because it is difficult to estimate the fire characteristics related to the various factors in buildings. In this study, real scale fire tests were conducted based on fire severity levels and fire loads provided in He New Zealand Building Code, in order to use the results as guidelines and fundamental data for performance-based designs. In the real scale fire tests conducted in a 10MW full-scale calorimeter, wood cribs were placed in a $2.4(L){\times}3.6(W){\times}2.4(H)m$ mock-up of a compartment which had one $0.8(L){\times}2.0(H)$ opening for different fire loads and heating was continued until all of the wood cribs were burned down. The heat release rate started to increase rapidly 90 seconds after the wood cribs caught fire. In the test with a fire load level 1, the maximum heat release rate of 4743.4 kW was reached at 244 second. In the test with fire load level 2, a maximum heat release rate of 5050.9 kW was reached at 497 second. In the test with fire load level 3, a maximum heat release rate of 4446.9 kW was reached at 677 second.

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

  • Kweon, Oh-Sang;Yoo, Yong-Ho;Kim, Heung-Youl
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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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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Fire Characteristics of Flaming and Smoldering Combustion of Wood Combustibles Considering Thickness (목재 가연물의 두께에 따른 화염연소와 훈소상태에서의 화재특성)

  • Kim, Sung-Chan;Nam, Dong-Gun
    • Fire Science and Engineering
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    • v.29 no.4
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    • pp.67-72
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    • 2015
  • A series of fire tests was conducted to examine the fire characteristics of flaming and smoldering combustion of engineered wood products, which have been widely used for furniture and finishing materials in buildings. The engineered wood products of MDF, plywood, and chipboard were ignited by a radiant cone heater with incident heat flux of $50kW/m^2$. During the fire test, key parameters representing the fire characteristics such as the heat release rate, yield rate of combustion product, and effective heat of combustion were quantified in terms of thickness. The tests show two peak points of HRRPUA due to lateral fire propagation in the initial stage, followed by later fire penetration through the specimen thickness. The mass loss rate of flaming combustion was 5 times higher than that of smoldering combustion, while the CO yield rate of smoldering combustion was 10 times higher than that of flaming combustion. This study can contribute to the understanding of fire behavior of wood combustibles and provide useful data for fire analysis.

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

  • Seo, Hyun Jeong;Jo, Jeong Min;Hwang, Wuk;Lee, Min Chul
    • Journal of the Korean Society of Combustion
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    • v.22 no.4
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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.

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

  • Cho, Dong-Hyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.6
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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.