• Title/Summary/Keyword: large fire

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Selection of Grid Size in Fire Simulation for Large Scale Buildings by Using FDS (FDS를 이용한 대규모 건축물 화재 시뮬레이션의 격자크기 선정)

  • Park, Woe-Chul
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.67-72
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    • 2012
  • Fire simulation was carried out for an enclosure with three doorways of $20{\times}10{\times}3m^3$ and a cleanroom of $44{\times}48{\times}10m^3$, to suggest appropriate grid size in fire simulations by using of FDS for large scale buildings. The variations of temperature and visibility with time were compared for the x and y direction grid sizes of 0.1~1.0 m (aspect ratios 0.5~5.0), fixing the z direction grid size 0.2 m. The results showed that the grid sizes 0.5 m (aspect ratio 2.5) or smaller are appropriate among the grid sizes tested, whereas 1.0 m is not acceptable. It was confirmed that estimate of the available safe egress time requires a great care due to fluctuations in temperature, visibility, etc., and further investigations on the grid size when selecting a large grid size inevitable, and on the aspect ratios for a larger grid are in need.

The combustion test of assuming in parking space for fire resistance (지하주차장의 내화성능 평가를 위한 차량연소실험)

  • Kang, Seung Goo;Kim, Dong Jun;Lee, Jae Young;Harada, Kazunori;Kwon, Young Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.48-50
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    • 2013
  • In this study, Car fire for test using ISO 9705 10MW Large Scale Calorimeter. Especially, study on the underground parking for the fire resistance performance. The underground parking lot of the fire resistance regulations in according to with the standard heating curve in Korea. Because of this burning car through experiments to the propose a new heating curve.

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An Experimental Study on the Pressure Range of Fire Cupping Method

  • An, Soo Kwang;Kim, Ku Weon;Lee, Ha Lim;Lee, Tae Wook;Kim, Eun Seok;Lee, Byung Ryul;Yang, Gi Young
    • Journal of Acupuncture Research
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    • v.38 no.3
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    • pp.200-204
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    • 2021
  • Background: Standardized procedures for the clinical application of fire cupping methods have not been established. In particular, the pressure parameters have not been fully characterized and described. Therefore, using various materials, this study investigated the pressure range exerted during fire cupping therapy. Methods: In this study, 3 differently sized (small, medium, large) glass and bamboo cups were used in the cotton ball fire cupping procedure to measure the pressure inside the cup applied to a human skin model. The pressure in each cup was measured 15 times for a total of 90 measurements. Results: A small bamboo cup had the minimum overall pressure (-305.4 mmHg), whereas the large glass cup exerted the maximum pressure (-401.3 mmHg), followed by the medium glass cup, large bamboo cup, small glass cup, and medium bamboo cup. The average pressure exerted by the cotton ball method for all cups ranged from -348.715 mmHg to -358.694 mmHg (95% confidence interval). Overall, the glass cups had a greater pressure than the bamboo cups in all groups (p < 0.001). Among the glass cups used, the larger the size of the cup, the higher the average pressure detected (-381.947 mmHg to -391.973 mmHg; p < 0.05). Conclusion: Large glass cups which are widely used in clinical practice, when used in the fire cupping method exerted pressure ranging from -381.947 mmHg to -391.973 mmHg (95% CI).

Spring Forest-Fire Variability over Korea Associated with Large-Scale Climate Factors (대규모 기후인자와 관련된 우리나라 봄철 산불위험도 변동)

  • Jeong, Ji-Yoon;Woo, Sung-Ho;Son, Rack-Hun;Yoon, Jin-Ho;Jeong, Jee-Hoon;Lee, Suk-Jun;Lee, Byung-Doo
    • Atmosphere
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    • v.28 no.4
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    • pp.457-467
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    • 2018
  • This study investigated the variability of spring (March-May) forest fire risk in Korea for the period 1991~2017 and analyzed its relationship with large-scale climate factors. The Forest Weather Index (FWI) representing the meteorological risk for forest fire occurrences calculated based on observational data and its relationship with large-scale climate factors were analyzed. We performed the empirical orthogonal function (EOF) analysis on the spring FWI. The leading EOF mode of FWI accounting for about 70% of total variability was found to be highly correlated with total number of forest fire occurrences in Korea. The high FWI, forest fire occurrence risk, in Korea, is associated with warmer atmosphere temperature in midwest Eurasia-China-Korea peninsula, cyclonic circulation anomaly in northeastern China-Korea peninsula-northwest pacific, westerly wind anomaly in central China-Korea peninsula, and low humidity in Korea. These are further related with warmer sea surface temperature and enhanced outgoing longwave radiation over Western Pacific, which represents a typical condition for a La $Ni\tilde{n}a$ episode. This suggests that large-scale climate factors over East Asia and ENSO could have a significant influence on the occurrence of spring forest fires in Korea.

RSET Analysis According to the Width of Escape Routes in Large Supermarkets (대형마트의 피난로 폭에 따른 RSET 분석)

  • Boohyun Baek;Hongsang Lee;Hasung Kong
    • Journal of the Korea Safety Management & Science
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    • v.26 no.3
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    • pp.29-38
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    • 2024
  • The purpose of this study is to use an evacuation simulation program to measure the change in evacuation time according to the width of the evacuation route due to the installation of an intermediate sales counter and the placement of a shopping cart between the sales counters of a large supermarket and to analyze the results. Currently, the "Distribution Industry Development Act" does not regulate the size and installation method of intermediate sales counters installed between sales counters that serve as practical evacuation routes in the event of a fire at a large supermarket, the size of shopping carts, etc. Considering this, we set evacuation route widths of 40, 50, 60, 70, 80, and 100 cm and compared and analyzed evacuation times according to various variables in the facility space. As a result of the experiment, as the width of the evacuation route was expanded, there was a significant difference in the evacuation time, from a maximum of 468.3 seconds to a minimum of 320.8 seconds. Considering the safety of evacuees in large supermarkets used by many people, it is time to regulate the size of intermediate sales stands installed between sales counters in large supermarkets and shopping carts that can become obstacles in an emergency.

A Numerical Study of the Effect off Fire Growth Model on Fire Characteristics in a Carriage (화재 성장 모델이 객차내 화재 특성에 미치는 영향에 관한 수치해석적 연구)

  • 김성찬;유홍선;최영기;김동현
    • Journal of the Korean Society for Railway
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    • v.7 no.3
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    • pp.180-185
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    • 2004
  • The present study investigates the effect of fire growth model on fire development characteristics in a carriage. The parallel processing version of FDS code is used to simulate the fire driven flow in a carriage and two types of fire growth model which are flame spread model and t$^2$ model are examined for the same geometrical condition. The heat release rates(HRR) of both model are similar each other until 30 s after ignition, but the flame spread model predicts 5 times higher than those of the t$^2$ fire model during the quasi-steady fire period. Maximum heat release rate in the case of flame spread model reaches about to 12 MW at 100 s after fire ignition. Also, various database of fire properties for combustible materials and more elaborate combustion model considering the flame spreading phenomena are required for better predictions of fire development characteristics using numerical simulation.

A Study on Fire Spread between Office Room and Atrium in the Atrium Building

  • Lee, Su-Kyung;Kim, Jong-Hoon;Ko, Han-Mog
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.345-352
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    • 1997
  • We could analyse the fire behavior using the developed software for fire safety assessment in a large space such as atrium. But Korean building law hasn't admitted the result of fire risk assessment in atrium. In the legislation fire resistant wall or shutter must be required between atrium and office rooms, That has obstructed development of building design and fire protection technique in Korea. From this point of view, we made scenarios of fire spread between atrium and office rooms, and then computed fire spread and fire phenomena using FASTLite and Breakl. In this study, we can decide that fire compartmentalization between atrium and office rooms doesn't require in Atrium building if the material and fire protection system were reliable. Consequently, Korean Fire Protection Regulations have to consider in direction of increasing freedom of building.

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A Study on the Fire Risk Assessment : Based on the Proposal of a Fire Risk Assessment Processor Considering the Reality in Korea (화재위험도 평가에 대한 연구 : 국내 현실을 고려한 화재위험도 평가 프로세서 제안을 중심으로)

  • Lee, Jong Hwa
    • Journal of the Korea Safety Management & Science
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    • v.23 no.1
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    • pp.57-64
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    • 2021
  • Recently, advanced countries assessment the risk of fire to prevent large-scale damage to high-rise buildings, In addition, performance-Based design, which is a fire risk assessment, is being conducted in Korea to prevent massive damage to high-rise buildings. However, unlike advanced countries, fire risk assessment in Korea is subject to fire risk assessment only for objects subject to consent from fire-fighting facilities such as building permits, When building engineers and fire-fighting engineers assessment the risk of fire, It has always been discussed because the results vary depending on which part of the evaluation is focused between economic feasibility and safety. Therefore, in this study, we would like to propose a fire risk assessment process suitable for domestic conditions by comparing the process of performance-based design, which is a domestic fire risk assessment, and the process of Iso/TC 16732 which is an overseas fire risk assessment.

An experimental study on development of water mist fire-fighting systems for Ro-Ro spaces (Ro-Ro 구역용 미분무 소화설비의 개발을 위한 실험적 연구)

  • Kwark, Ji-Hyun;Kim, Young-Han
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.8
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    • pp.946-952
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    • 2013
  • Large scale fire tests were conducted to develop water mist nozzles as a component of fixed water- based fire fighting systems for Ro-Ro spaces and special category spaces. Fire scenarios for this system consist of two cases which are for cargo fire in a simulated truck and for passenger vehicle fire, and each case has 3 different tests according to the position between fixed water mist nozzles and fire source. Every experiment proceeded for 30 minutes and acceptance criteria were based on gas temperature, fuel package's damage and ignition of targets. This study primarily dealt with the experimental results of cargo fire and focused on fire suppression capability in accordance with discharge pressure, flow rate and flow characteristics like swirl and penetration of the developed water mist nozzles. It appeared that low pressure water mist nozzles with about 40 L/min were able to control fire occurred in Ro-Ro spaces.

A Toxicity of Interior Upholstery in Apartment Housing (아파트 마감재의 연기 유독성)

  • Ham, Sang-Keun;Kim, Hong;Han, Sang-Bum;Kim, Woon-Hyung
    • Fire Science and Engineering
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    • v.15 no.3
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    • pp.36-43
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    • 2001
  • Several types of widely used interior upholsteries including wallpaper, veneer board and floor cover, were selected to be evaluated by using the method of NES 713 text. Test results indicates that a fire with retardant wallpaper release a large amount of toxic gases when constantly exposed to a fire source. When evaluated in terms of the masses of released gases, the release of Carbon monoxide appears the highest in case of wallpaper fire, while the ratio of CO/Mass loss appears the highest in case of floor cover fire. Therefore, it can be concluded that, a large amount of toxic gas will release from a floor cover fire with even a small quantity of fuel.

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