• Title/Summary/Keyword: fire condition

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Application of Horizontal Barrier on a Rack to Reduce Fire Spread (화재확산 저감을 위한 랙크 내 수평차단막 적용에 관한 연구)

  • Yeo, In-Hwan;Cho, Gyu-Hwan
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.71-79
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    • 2017
  • A rack warehouse with a vertically loading type and high loading density has severe risks and damage during its fire. In this regard, US and Japan strive to minimize the fire spread by applying in-rack sprinkler, horizontal barriers, etc. corresponding to their own rack warehouse but there is no study and policy in Korea. Therefore, a model scale fire test was carried out targeting the standard rack incorporating the national rack warehouse in order to check fire characteristics in ignition points and installation distances of horizontal barriers in this study. As a result of the test, vertical fire spread of about 30% was inhibited by narrowing its installation distance from 2-layer to 1-layer in an ignition condition of the flue space. In addition, as a result of the measurement of the temperature in the upper and lower parts of the horizontal barrier, the temperature distribution showed about 2~4 higher in a condition with an installation of the barrier than that in the condition without the barrier. Consequently, it is likely that the horizontal barrier will help the initial operation of in-rack sprinkler.

An Experimental Study on the Thermal Property of Concrete under the Load Ratio Condition in Fire (화재시 하중재하에 따른 콘크리트의 열적특성에 관한 실험적 연구)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Park, Kyung-Hun;Jung, Jae-Young;Kwan, Ki-Hyuk
    • Fire Science and Engineering
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    • v.23 no.6
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    • pp.66-74
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    • 2009
  • When a fire occurs, the concrete structure's strength decreases by the increasing temperature under the fire in certain condition of constant load. And, the ratio of the axial force is changed by such decreased strength so that the structure is deformed. In this research, considering such case, we have conducted an actual fire test for the concrete lining with constant loading condition and various fire conditions. The specimen adopts the shape condition for small practical specimen defined by the EFNARC and we used 24MPa, 40MPa and 50MPa to analyze the thermal properties by the strength. The ratio of loading is imposed by a certain loading condition based on 20% and 40% of the sectional stress in concrete and MHC Fire is selected to realize the thermal impact of the concrete by rapid increasing temperature. As the result of the experiment, in the same ratio of loading, the 50MPa specimen shows more cracks and spalling as time goes on. The area damaged by the fire, according to the functional criteria of the concrete lining under the fire in ITA, does not satisfy with the standard in lack of 50mm depth from the heating surface at total 200mm lining.

An Analysis of the Opening and Closing Condition with Various Fire Door Size in the Pressurized Room (부속실 출입문 크기 변화를 고려한 개방 및 폐쇄조건 분석)

  • You, Woo-Jun;Nam, Jun-Seok;Ryou, Hong-Sun
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.132-137
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    • 2011
  • A relationship between resisting moment and the structure of an automatic closure device is introduced for analyzing the effect of opening and closing condition on various fire door sizes in the pressurized room for smoke control system. The larger the size of fire door is, the more force is required for reaching to opening and closing conditions and there exists the design range of fire door in the pressurized room reflecting the closing time of fire door, rotative velocity, a relation between rotative angle and force and the efficiency of the automatic closure device.

Study on the Fire Hazard and Risk Analysis Derived from the Plant Configuration Change During the Shutdown Period at Nuclear Power Plants

  • Jee Moon-Hak;Hong Sung-Yull;Sung Chang-Kyung;Jung Hyun-Jong
    • Nuclear Engineering and Technology
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    • v.35 no.6
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    • pp.547-555
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    • 2003
  • Fire hazard and risk analysis at Nuclear Power Plants is implemented on the basis of the normal operational configuration. This steady configuration, however, can be changed due to the temporary displacement of equipment, electric cable and irregular movement of workers through the fire compartments when the on-line maintenance is processed during the power operation mode or the scheduled outage mode for the refueling. With the consequence of this configuration change, the fire analysis condition and the evaluation result will be different from those that were analyzed based on the steady configuration. In this context, at this paper, the general items for the reassessment are categorized when the configuration has changed. The contemporary zone models for the detail fire analysis are also illustrated for their application for each classified condition.

An Experimental Study on the Fire Hazard of Electric Heating Pad (전기장판의 화재위험성 실험연구)

  • Lee, Bok-Young;Park, Chan-Ho;Park, Sang-Tae;Hong, Sung-Ho;Yu, Hyun-Jong
    • Fire Science and Engineering
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    • v.20 no.3 s.63
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    • pp.113-117
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    • 2006
  • This study presents analysis of fire hazard of electrical heating pad. In order to analyze fire hazard fire experimental and flammability experiment is conducted. The fire experiment is conducted to simulate normal condition and abnormal condition such as breakdown of thermostat. Vertical burning test(UL 94) is conducted for the fire retardant experiment. Kinds of electric heating pad used for experiment are electric mat, fabric pad, vinyl pad. The results show that fire hazard is high in case of breakdown of thermostat with the rating voltage supply. And Material of electric heating pad has not fire retardant performance.

A FORECASTING METHOD FOR FOREST FIRES BASED ON THE TOPOGRAPHICAL CLASSIFICATION SYSTEM AND SPREADING SPEED OF FIRE

  • Koizumi, Toshio
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.311-318
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    • 1997
  • On April 27,1993, a forest fire occurred in Morito-area, Manba-city, Gunma-prefecture Japan. Under the prevailing strong winds, the fire spread and extended to the largest scale ever in Gunma-prefecture. The author chartered a helicopter on May 5, one week after the fire was extinguished, and took aerial photos of tile damaged area, and investigated the condition. of the fire through field survey and data collection. The burnt area extended. over about 100 hectares, and the damage amounted to about 190 million yen (about two million dollar). The fire occurred at a steep mountainous area and under strong winds, therefore, md and topography strongly facilitated the spreading, It is the purpose of this paper to report a damage investigation of the fire and to develop the forecasting method of forest fires based on the topographical analysis and spreading speed of fire. In the first place, I analyze the topographical structure of the regions which became the bject of this study with some topographical factors, and construct a land form classification ap. Secondly, I decide the dangerous condition of each region in the land form classification map according to the direction of the wind and spreading speed of f'kre. In the present paper, I try to forecast forest fires in Morito area, and the basic results for the forecasting method of forest fires were obtained with the topographical classification system and spreading speed of fire.

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An Experimental Study on the Thermal Property of Concrete under the Load Ratio Condition in Fire (고온화재조건 콘크리트 라이닝의 하중비에 따른 폭렬영향성 및 화재손상특성에 관한 실험적 연구)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Park, Kyung-Hun;Ahn, Chan-Sol;Kwon, Ki-Hyuk
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.145-151
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    • 2010
  • The fire in tunnel, when failed to extinguish at early stage, tends to easily develop to high temperature and spread to entire area of the tunnel because of considerable level of fire load and smoke control facility within the tunnel, resulting in severe damage to the people and tunnel structure. This study was intended to carry out the fire test with MHC fire curve, a scenario, which has the most rapid fire rise, on assumption of load ratio of 1, 20, 40, 60 and 70%, so as to identify the thermal characteristics of the concrete against spalling and the range of fire damage. The specimen was small scale sample as defined by EFNARC and the mixing ratio was based on 24 MPa, which is considered to be the normal strength. As a result of test, 16mm spalling was occurred on the lining under the non-load condition, while no spalling was occurred with 20% and 40% of load ratio. In case of 60% of load ratio, 24 mm of spalling was occurred and it failed in 10 minutes after heating in case of 70% load condition.

A Study on the Safety and Health Consciousness for the Working Environment of Fire Fighter (소방공무원 근무환경에 대한 안전보건 의식 연구)

  • Lee, Jong-Ho;Kim, Yo-Han
    • Journal of the Korean Society of Safety
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    • v.30 no.1
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    • pp.137-143
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    • 2015
  • Fire fighter are exposed to the situations which are hard to predict due to continuous and accidental changes which hinder their fire fighting activity. As these threats of safety accident act as fear factors, they are doing insecure fire fighting activities. Therefore, as unclear and abnormal risks of working environment such as the riskiness of expansion of disaster, instability, obstacles of activities, abnormality, urgency, etc. increase, safety accidents are caused. This study analyzes the actual condition of safety and health and awareness of fire fighter who are exposed safety accidents during their fire fighting activities and utilize such result as the basis data to secure safety of fire fighter, keep efficient safety control and prevent accidents. The results of analysis are as follows. As rescue works among all fire-fighting works shows the highest emotional stabilization and the highest post-traumatic stress disorder is shown in fire sergeant level positions, and fire fighters whose working period is 10-15 years, reinforcing safety training to long-term workers is necessary. As the result of survey regarding safety awareness, the highest awareness level was shown in fire sergeant level positions, and fire fighters whose working period is over 20 years, and when it comes to operation of fire fighting equipments, fire-fighting workers and workers having 1-4 years of working period showed high safety awareness. The more serious injury in a fire fighter experienced as the first injury after working as a fire-fighter, the more cause-and-effect relationship was shown between personal physical condition and work, and it is shown as obstacles of fire fighting activities and affects to post-traumatic stress disorder. Moreover, as after-work off duty activities also affect to official disaster, systematic improvement of working environment is required. Occupational medical work compatibility evaluation considering the distinct characteristics of works to secure fire-fighter' health care together with fire-fighting capability is shown to be necessary.