• Title/Summary/Keyword: fire growth

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A Numerical Study of a Room Fire for Fire Sizes II. wall fire and corner fire (FDS를 이용한 실내화재 모사의 문제점 II. 벽면형 및 모서리형 화재)

  • Ko Kyung-Chan;Park Woe-Chul
    • Journal of the Korean Society of Safety
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    • v.19 no.3 s.67
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    • pp.9-13
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    • 2004
  • To confirm the previous finding that FDS predicts a fire growth rate too rapid compared with an experiment in a center fire in a room with an opening, the same computational fluid dynamics was applied to two types of fires, wall fire and comer fire. First the grid size was chosen to eliminate possible numerical errors due to a coarse grid system. Then the two types of fires were simulated for three different fire sizes, 7.65, 21.25, and 51.57kW for each type, which are the same as in the experiment to be compared with. The fires were predicted to grow too fist although the average temperatures and heights of the neutral planes were in good agreement with measurement.

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.

Evaluation of the Prediction of B-RISK-FDS-Coupled Simulations for Multi-Combustible Fire Behavior in a Compartment (구획실 내 가연물들의 화재거동에 대한 B-RISK와 FDS 연계 화재 시뮬레이션 예측성능 평가)

  • Baek, Bitna;Oh, Chang Bo
    • Fire Science and Engineering
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    • v.33 no.4
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    • pp.50-58
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    • 2019
  • The prediction performance of B-RISK was evaluated for the fire behaviors of combustibles in a compartment using Fire Dynamics Simulator (FDS). First of all, to predict the heat release rate (HRR) for two combustible sets, the HRR for one combustible set and the design fire curve were used as input values for B-RISK. Comparing results of B-RISK calculations with experimental data for two combustible sets, it was found that B-RISK results predicted insufficiently for fire growth rate of experimental data but there was good agreement for maximum HRR and total HRR with the experimental data. And the B-RISK results were used for input values of FDS to evaluate the fire behaviors of B-RISK results. Comparing results of FDS calculations with experimental data, the simulation results showed that the temperature and concentrations of O2, CO2 in the fire growth phase were different from the experimental data. However, when using the B-RISK result for percentile 70%, the simulation results sufficiently predicted the overall fire behaviors.

Combustion Characteristics Analysis of a Non-class 1E Cable for Nuclear Power Plants according to Aging Period (경년열화 기간에 따른 원자력발전소용 비안전등급 케이블의 연소특성 분석)

  • Kim, Min Ho;Lee, Seok Hui;Lee, Min Chul;Lee, Sang Kyu;Lee, Ju Eun
    • Journal of the Korean Society of Safety
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    • v.35 no.5
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    • pp.22-29
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    • 2020
  • In this study, combustion and smoke release characteristics of a non-class 1E cable for nuclear power plants were investigated according to aging period. The aging was reproduced through an accelerated aging method for interval of 10 years :10, 20, 30 and 40 year, which was applied the Arrhenius equation. The cable was subjected to accelerated aging. In order to understand combustion and smoke release characteristics, the cone calorimeter test was performed according to the standard code of KS F ISO 5660-1. Heat release rate, mass loss rate, average rate of heat emission and smoke production rate were examined through cone calorimeter test. Fire performance index, fire growth index and smoke factor were derived from test results for the comparison of quantitative fire risk. When comparing the fire performance index and the fire growth index, the early fire risk tends to decrease as aging progresses, which might be attributed from the fact that the volatile substances of cables were evaporated. However, when comparing the heat release rate, average rate of heat emission and mass loss rate, which represent the mid and late periods of the fire risk, the values of accelerated aging cables were much higher than those of non-aged cable, which signifies the unstable formation of the char layer resulted in the change in the performance of flame retardants. In addition, the results from the smoke characteristics show that the accelerated aging cables were lager than the non-aged cables in terms of overall fire risk. These results can be used as baseline data when assessing fire risk of cables and establishing fire safety code for nuclear power plants.

Study on the influence of life-style on infertility (불임(不姙)과 생활습관의 상관성에 대한 연구)

  • Bang, Jung-Kyun
    • The Journal of Korean Medical History
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    • v.18 no.1
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    • pp.3-14
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    • 2005
  • Among modern people's life-style, the lack of exercise and sleep is related to infertility. Underexercise accumulates damp-sputum, resulting in the insufficiency of essence. It also obstructs the creation of essence, leading to insufficient essence. Activities at night without sleep cannot create the condition to help the process of yin, causing the insufficiency of essence. Fast food is made from the cattle which are fed the feed containing growth hormone and antibiotics in large quantities. Growth hormone causes the process of yang excessively in human body, while antibiotic suppresses the process of yin, leading to excessive damp-heat and hyperactive ministerial fire. Antiseptic included in instant food hampers the process of fermentation, or yin, and inhibits the digestion mechanism, obstructing damp-heat and bringing about hyperactive ministerial fire. Intake of excessive flesh and meat gives rise to incomplete combustion and hinders the creation of essence, causing hyperactive ministerial fire due to the lack of yin. Milk suits the calf that has a rapid growth cycle. Milk intake by humans leads to the rapid process of yang and eventually hyperactivity of ministerial fire. The imbalance between yin and yang, with essence insufficent and ministerial fire hyperactive, causes infertility in three aspects. First, the lack of essence itself makes conception difficult. Secondly, damp-sputum resulting from ministerial fire obstructs the circulation of qi and blood. It also hampers the normal supply of qi and blood to the uterus. Thirdly, the excessive process of yang may result in infertility. Generally speaking, pregnancy starts with implantation. If the excessive process of yang is in progress in body, static condition needed for implantation cannot be maintained, leading to infertility.

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A Review on The Field Model for Fire Simulation (화재 Simulation에서의 Field Model)

  • 김진곤
    • Fire Science and Engineering
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    • v.8 no.1
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    • pp.26-33
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    • 1994
  • The review of field model for fire simulation is presented. The approach to predict ire growth by solving the conservation equations over time and 2- or 3-dimentional space with appropriate boundary conditions is called field model. The finite difference method is adopted to solve the governing equations. The results is give qualititively and quantitatively good results but complicate and difficult to handle. But it is useful tool to understand detail phenomenons and to make decision for fire safety.

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FIRE PROTECTION FOR PETROCHEMICAL PLANT

  • Suh, Jung-H.
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.244-251
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    • 1997
  • Since 1970s, The Petrochemical Industry in Korea has grown rapidly by the successful economic growth. While the process became larger and more complex, hazardous chemicals have been used in large quantity, Therefore, the risk of a major accident such as fire, explosion and toxic material release has been increased. Korea has been ranked the fifth in petrochemical product capacity worldwide, also required to meet international standards on process safety management. Fire Protection System integral part of safely management in Petrochemical Plants, will be reviewed.

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A Study on the Fire Safety Design and Predicting Fire Behavior Using Compartment Fire Test (단일화재실험을 통한 화재성상예측 및 건축구조물의 화재안전 설계에 관한 연구)

  • Yoon, Ung-Gi;Seo, Dong-Goo;Kim, Dong-Eun;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.107-108
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    • 2013
  • In this study, combustibles investigation and fire growth rate experiment were performed for predicting initial fire behavior in buildings. Combustibles investigation was performed for residential buildings, which is most frequently affected by fire in Korea. Spatial characteristics and combustibles properties were separately investigated, and occupied area and layout characteristics of combustibles were identified to produce general layout models. Of the layout models, room was selected for fire test of a single compartment. From this test, fire propagation for each combustible was identified, which was delayed compared to the summed heat release rate of a single combustible.

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