• Title/Summary/Keyword: fire growth rate

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Heat Risk Assessment of Wood Coated with Boron/Silicone Sol (붕소/실리콘 졸로 도포된 목재의 열위험성 평가)

  • Jin, Eui;Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.33 no.3
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    • pp.9-20
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    • 2019
  • This study was examined fire risk properties of wood specimen for the constructional interiors, especially focusing on the fire performance index (FPI) and the fire growth index (FGI) as heat hazard characteristics. Flame retardants were synthesized using boric acid, boronic acid and tetraethoxyorthosilicate. Heat release characteristics were measured by using a cone calorimeter (ISO 5660-1) and cypress was used. The external heat flux as fire intensity was maintained at 50 kW/㎡. The measured fire performance index (FPI) after burning was increased by 1.6 times for boric acid/silicone (BA/Si) sol, each 1.1 times for isobutylboronic acid/silicone (IBBA/Si) sol and phenylboronic acid/silicone (PBA/Si) sol compared with cypress. Fire risk by the fire performance index was increased BA/Si, IBBA/Si ≈ PBA/Si order. The fire growth index was decreased 94% for the BA/Si and 8% for the IBBA/Si sol, and was increased by 17% for the PBA/Si sol. Fire risk by the fire growth index was increased BA/Si, IBBA/Si, PBA/Si order. Overall fire risk was higher in the order of BA/Si < IBBA/Si < PBA/Si.

Heat Release Rate Measurements of Residential Combustibles Using Oxygen Consumption Method (산소소모법을 이용한 주택 가연물 발열량 측정)

  • Choi, Byung-Il;Han, Yong-Shik;Kim, Myung-Bae
    • Fire Science and Engineering
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    • v.22 no.2
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    • pp.104-107
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    • 2008
  • Heat release rates of main combustibles in residence area were measured by a calorimeter using oxygen consumption method. It was found that the peak heat release rates of the combustibles were 1.0MW for a refrigerator, 0.8MW for a desk, 4.2MW for a wardrobe and 0.4MW for a bed. Especially, the refrigerator and wardrobe were found to be very hazardous because of their fast fire growth rate.

A Prediction study on the Fire growth rate of Combustible for Fire Safety Assesment of PBD(1) (성능적인 화재안전성평가를 위한 주요가연물의 화재성장율 예측에 관한 연구(1))

  • Seo, Dong-Goo;Kim, Dong-Eun;Kim, Bong-Chan;Kwon, Young-Jin
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2012.04a
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    • pp.129-132
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    • 2012
  • 본 연구는 건축물의 초기화재성상의 주요인자인 화재성장율 예측을 위하여, 일본 송산(松山)모델을 사용하여 예측값을 도출한 결과, 화재성장율은 $0.0144t^2$로 나타났다. 또한 이를 실규모실험(ISO-9705)와 FDS 해석값과 비교한 결과, $Q_{peak}$을 고려한다면 신뢰할 수 있다고 판단 할 수 있지만 약100초 이상의 결과에서는 환기인자 등에 관한 변수에 대한 고려가 필요할 것으로 판단된다.

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Performance Evaluation of FDS for Predicting the Unsteady Fire Characteristics in a Semi-Closed ISO 9705 Room (반밀폐된 ISO 9705 화재실에서 비정상 화재특성 예측을 위한 FDS의 성능평가)

  • Mun, Sun-Yeo;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.26 no.3
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    • pp.21-28
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    • 2012
  • The objective of this study is to evaluate the prediction accuracy of FDS(Fire Dynamic Simulator) for the thermal and chemical characteristics of under-ventilated fire with unsteady fire growth in a semi-closed compartment. To this end, a standard doorway width of the full-scale ISO 9705 room was modified to 0.1 m and the flow rate of heptane fuel was increased linearly with time (until maximum 2.0 MW based on ideal heat release rate) using a spray nozzle located at the center of enclosure. To verify the capability of FDS, the predicted results were compared with a previous experimental data under the identical fire conditions. It was observed that with an appropriate grid system, the numerically predicted temperature and heat flux inside the compartment showed reasonable agreement with the experimental data. On the other hand, there were considerable limitations to predict accurately the unsteady behaviors of CO and $CO_2$ concentration under the condition of continuous fire growth. These results leaded to a discrepancy between the present evaluation of FDS and the previous evaluation conducted for steady-state under-ventilated fires. It was important to note that the prediction of transient CO production characteristics using FDS was approached carefully for the under-ventilated fire in a semi-closed compartment.

Fire Risk of Wood Treated With Boron Compounds by Combustion Test (연소시험에 의한 붕소 화합물 처리 목재의 화재위험성)

  • Jin, Eui;Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.32 no.3
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    • pp.19-26
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    • 2018
  • Experiments on the combustion characteristics of untreated wood specimens and also treated ones with boric acid and ammonium pentaborate were carried out using a cone calorimeter according to ISO 5660-1 standard. As a result, comparing to untreated specimen, the fire performance index (FPI) of the specimens treated with boron compounds increased by 1.2 to 2.1 times and the fire growth index (FGI) increased by 1.6 to 8.4%. Also, total smoke release rate (TSR) was 9.0 to 28.3% lower than that of the untreated specimen. It is understood that the test specimens treated with the boron compound produces a carbonized layer with a flame retarding effect. The highest CO concentration, 0.01112%, for the untreated specimen was observed at 418 s, but the specimens treated with boron compound decreased 13.2 to 37.5% compared to untreated specimen. Therefore, wood treated with boron compounds is expected to have lower fire hazards and risks.

A Study on the Arson Characteristic by the Economic Variable (경제적변수에 따른 방화특성에 관한 연구)

  • Park, Nam-Kwun;Yoon, Myong-O
    • Fire Science and Engineering
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    • v.25 no.3
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    • pp.14-19
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    • 2011
  • This research was conducted with goals to reducing arson and finding its relationship with social phenomenons. Especially, unlike previous researches, focus has been on the economic indicators, and the effect of economic indicators on arson. As a result, we were able to find the relationship between economic indicators and arson. When growth rate and consumer index prices decrease, the economy stagnates and thus incidents of arson increases. In contrast, when growth rate increases and consumer index prices increase, the rate in which arson occurred decreased. Also, we have found that when personal debt rate increases, the numbers of arson incidents increased as well.

A Study on Combustion Characteristics of Methane-air Homogeneous Mixture in a Constant Volume combustion Chamber by FIRE Code (FIRE Code를 사용한 정적연소기의 메탄-공기 균질 혼합기 연소특성 연구)

  • Lee, Suk-Young;Huh, Kang-Yul
    • Journal of the Korean Society of Combustion
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    • v.11 no.2
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    • pp.28-36
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    • 2006
  • A constant volume combustion chamber was used to investigate the combustion characteristics. of homogeneous charge of methane-air mixture under various initial pressure, equivalence ratio and ignition times. The constant volume combustion chamber(CVCC) mostly has been studied by the experiments of visualization until now. So it is needed the numerical analysis of fluid and combustion characteristics in chamber by the more detail simulation. In this paper, the numerical analysis is tried to approach basically the homogeneous charge combustion phenomena under the various conditions, and the combustion phenomena in chamber is numerically analyzed by the commercial FIRE code. As a results, the combustion phenomena which were mean temperature, OH radical and reaction rate in chamber were investigated and it showed that the smallest flame growth occurs for the lean state and the increase of initial charged pressure condition due to the reduced OH radical.

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Development of the Surface Forest Fire Behavior Prediction Model Using GIS (GIS를 이용한 지표화 확산예측모델의 개발)

  • Lee, Byungdoo;Chung, Joosang;Lee, Myung-Bo
    • Journal of Korean Society of Forest Science
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    • v.94 no.6
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    • pp.481-487
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    • 2005
  • In this study, a GIS model to simulate the behavior of surface forest fires was developed on the basis of forest fire growth prediction algorithm. This model consists of three modules for data-handling, simulation and report writing. The data-handling module was designed to interpret such forest fire environment factors as terrain, fuel and weather and provide sets of data required in analyzing fire behavior. The simulation module simulates the fire and determines spread velocity, fire intensity and burnt area over time associated with terrain slope, wind, effective humidity and such fuel condition factors as fuel depth, fuel loading and moisture content for fire extinction. The module is equipped with the functions to infer the fuel condition factors from the information extracted from digital vegetation map sand the fuel moisture from the weather conditions including effective humidity, maximum temperature, precipitation and hourly irradiation. The report writer has the function to provide results of a series of analyses for fire prediction. A performance test of the model with the 2002 Chungyang forest fire showed the predictive accuracy of 61% in spread rate.

Smoke Hazard Assessment of Cypress Wood Coated with Boron/Silicon Sol Compounds (붕소/실리콘 졸 화합물로 도포된 편백 목재의 연기유해성 평가)

  • Jin, Eui;Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.34 no.1
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    • pp.1-10
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    • 2020
  • In this study, boron/silicon sol compounds were applied to wood for construction and durable materials, and fire risks were investigated in terms of smoke performance index (SPI), smoke growth index (SGI), and smoke intensity (SI). The compound was synthesized by reacting tetraethoxyorthosilicate with boric acid and boronic acid derivatives. Smoke characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment for cypress wood. The fire intensity fixed the external heat flux at 50 kW/㎡. The smoke performance index measured after the combustion reaction increased between 13.4% and 126.7% compared with cypress wood. The fire risk due to the smoke performance index decreased in the order of cypress, phenylboronic acid/silicon sol (PBA/Si), (2-methylpropyl) boronic acid/silicon sol (IBBA/Si), boric acid/silicon sol (BA/Si). The smoke growth index decreased between 12.0% and 57.5% compared to the base specimen. The risk of fire caused by the smoke growth index decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si. The fire risk due to smoke intensity decreased between 3.2% and 57.8%, and in the order of cypress, PBA/Si, IBBA/Si, BA/Si. COpeak concentrations ranged between 85 and 93 ppm, and decreased between 37% and 43% compared to the base specimen. A comprehensive assessment of the fire risk on smoke hazards decreased in the order of cypress, PBA/Si, IBBA/Si, BA/Si.

A Numerical Study on the Effects of the Wind Velocity and Height of Grassland on the flame Spread Rate of Forest Fires (초지화재 발생시 바람의 속도 및 초본의 높이가 화염전파에 미치는 영향에 대한 수치해석적 연구)

  • Bae, Sung-Yong;Kim, Dong-Hyun;Ryou, Hong-Sun;Lee, Sung-Hyuk
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.252-257
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    • 2008
  • With the rapid exuberant growth of the forest, the number and size of forest fires and the costs of wildland fires have increased. The flame spread rate of forest fires is depending on the environmental variables like the wind velocity, moisture of grassland, etc. If we know the effects of the environmental variables on the fire growth, it is useful for wildland fiIre suppression. But analysis of the spread rate of wildland fire for these effects have not been established. In this study, the effects of wind velocity and height of grassland fuel have been investigated using the WFDS which is developed at NIST for prediction of the spread of wildland fires. The results showed that the relation between the height of the fuel and the spread rate of the head fires is, and the spread rates related to the wind velocity are predicted 17% less than the experimental results of Australia. When the wind velocity is over 7.5m/s, the concentration of pyrolyzed gas phase fuel is getting low due to fast movement of pyrolyzed gas, the flame spread rate becomes slow.