• Title/Summary/Keyword: Fire growth

Search Result 350, Processing Time 0.024 seconds

Assessment of Fire Risk Rating for Wood Species in Fire Event (화재 발생 시 목재 수종의 화재위험성 등급 평가)

  • Jin, Eui;Chung, Yeong-Jin
    • Applied Chemistry for Engineering
    • /
    • v.32 no.4
    • /
    • pp.423-430
    • /
    • 2021
  • In order to evaluate the fire risk and fire risk rating of wood for construction materials, this study focused on fire performance index-III (FPI-III), fire growth index-III (FGI-III), and fire risk index-IV (FRI-IV) according to Chung's equations-III and -IV. Western red cedar, needle fir, ash, and maple were used as the specimens. The fire characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment on the specimen. The FPI-III measured after the combustion reaction was 0.86 to 12.77 based on polymethylmethacrylate (PMMA). The FGI-III was found to be 0.63 to 5.26 based on PMMA. The fire rating according to the FRI-IV, which is the fire rating index, was 0.05 to 6.12, and the western red cedar was 122.4 times higher than that of the maple. The fire risk rating according to the FRI-IV increased in the order of maple, ash, needle fir, PMMA and western red cedar. The CO peak concentration of all specimens was measured as 103 to 162 ppm, and it was 2.1 to 3.2 times higher than 50 ppm, the permissible exposure limits of the US occupational safety and health administration. Materials such as western red cedar, which have a low bulk density and contain a large amount of volatile organic substances, have a low FPI-III and a high FGI-III, so they have a high fire risk rating.

Mortality in Pine Stand and Vegetation Recovery after Forest Fire (산불발생 후 소나무 피해 및 식생복원 실태분석)

  • Lee, Si-Young;Jun, Kye-Won;Lee, Myung-Woog;Chun, Kun-Woo
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.8 no.1
    • /
    • pp.71-79
    • /
    • 2008
  • To find out the effect of the vegetation recovery and the problems of forest land, the researches of the mortality in pine stand and vegetation recovery have been carried out from the burned site. In area which is damaged by fire scar on crown and stem, rate of dead is higher. Where stand growing stocks were totally damaged by crown forest fire, most of vegetation was recovered by sprouts and planted seeds. Vegetation recovery power were depending on the condition of soil depth condition. For the artificial recovery, the damage happened by insects in the planted birches plantation. Rate of growth was somewhat different between Pinus densiflora and Pinus thunbergii in the plantation, because of individual growth rate.

A Correlation Study for the Prediction of the Maximum Heat Release Rate in Closed-Compartments of Various Configurations (다양한 형상의 밀폐된 구획에서 최대 열발생률 예측을 위한 상관식 검토)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
    • /
    • v.32 no.1
    • /
    • pp.16-23
    • /
    • 2018
  • In a closed-compartment with various configurations, the correlation that can predict the maximum heat release rate (HRR) with the changes in internal volume and fire growth rate was investigated numerically. The volume of the compartment was controlled by varying the length ratio based on the bottom surface shape of the ISO 9705 fire room, where the ceiling height was fixed to 2.4 m. As a main result, the effect of a change in ceiling height on the maximum HRR was examined by a comparison with a previous study that considered the change in ceiling height. In addition, a more generalized correlation equation was proposed that could predict the maximum HRR in closed-compartments regardless of the changes in ceiling height. This correlation had an average error of 7% and a maximum error of 19% for various fire growth rates when compared with the numerical results. Finally, the applicability of the proposed correlation to representative fire compartments applied to the domestic performance-based design (PBD) was examined. These results are expected to provide useful information on predicting the maximum HRR caused by flashover in closed-compartments as well as the input information required in a fire simulation.

Recoverability analysis of Forest Fire Area Based on Satellite Imagery: Applications to DMZ in the Western Imjin Estuary (위성영상을 이용한 서부임진강하구권역 내 DMZ 산불지역 회복성 분석)

  • Kim, Jang Soo;Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
    • /
    • v.28 no.1
    • /
    • pp.83-99
    • /
    • 2021
  • Burn severity analysis using satellite imagery has high capabilities for research and management in inaccessible areas. We extracted the forest fire area of the DMZ (Demilitarized Zone) in the western Imjin Estuary which is restricted to access due to the confrontation between South and North Korea. Then we analyzed the forest fire severity and recoverability using atmospheric corrected Surface Reflectance Level-2 data collected from Landsat-8 OLI (Operational Land Imagery) / TIRS (Thermal Infrared Sensor). Normalized Burn Ratio (NBR), differenced NBR (dNBR), and Relative dNBR (RdNBR) were analyzed based on changes in the spectral pattern of satellite images to estimate burn severity area and intensity. Also, we evaluated the recoverability after a forest fire using a land cover map which is constructed from the NBR, dNBR, and RdNBR analyzed results. The results of dNBR and RdNBR analysis for the six years (during May 30, 2014 - May 30, 2020) showed that the intensity of monthly burn severity was affected by seasonal changes after the outbreak and the intensity of annual burn severity gradually decreased after the fire events. The regrowth of vegetation was detected in most of the affected areas for three years (until May 2020) after the forest fire reoccurred in May 2017. The monthly recoverability (from April 2014 to December 2015) of forests and grass fields was increased and decreased per month depending on the vegetation growth rate of each season. In the case of annual recoverability, the growth of forest and grass field was reset caused by the recurrence of a forest fire in 2017, then gradually recovered with grass fields from 2017 to 2020. We confirmed that remote sensing was effectively applied to research of the burn severity and recoverability in the DMZ. This study would also provide implications for the management and construction statistics database of the forest fire in the DMZ.

A Study on the Improvement of Urban Fire Simulation on Firebrand Scattering (불티의 성상을 고려한 도시화재 시뮬레이션 개선에 관한 연구)

  • Koo, In-Hyuk;Seo, Dong-Goo;Kim, Bong-Chan;Kwon, Young-Jin
    • Fire Science and Engineering
    • /
    • v.29 no.5
    • /
    • pp.67-72
    • /
    • 2015
  • Korea urbanized rapidly, and overpopulation with high growth of the economy has resulted in decrepit facilities scattered all cities. If there is a strong wind during a fire, the fire is rapidly spread by various factors. Korea cannot build a prediction model for urban fire combustion phenomena because there are no studies that physically explain the suitable flame phenomena for its buildings. This study built a model for the generation of fire brand and includes to scattering, fall, and ignition An experiment was done using the wind tunnel facilities of the Japanese Building Research Institute (BRI). The results were used to explain the behavior of fire brand, and reflected in the fire simulation model.

Gas Fire Accident Cause Survey Study (가스화재사고 원인조사 연구(LP가스를 중심으로))

  • Kim, Young-Cheol;Cha, Jong-Ho
    • Journal of Korean Institute of Fire Investigation
    • /
    • v.11 no.1
    • /
    • pp.1-8
    • /
    • 2008
  • The purpose of this paper is to report gas fire accident based on classification of the major gas fire causes (including handling mistakes, inferior goods, etc.), fire classifications (fire, explosion, leakages, etc.), damage levels(1st, 2nd, 3rd, 4th grade levels), casualties (death, serious wound, slight injury) since gas fire has been generated according to growth of gaseous fuel consumption on home and enterprises with various accident causes. Among gaseous fuels, LPG facility can be c1assified as gas container, pressure regulator, gas hose, interim valve, combustion port. Any fire or any explosion can be caused from handling mistakes, inferior goods on each parts as stated above. Exact gas fire causes shall be identified based on previous case studies on similar fires with consideration of lesson learns.

  • PDF

The onset of extreme fire behaviour in a mine drift

  • Hansen, Rickard
    • Geosystem Engineering
    • /
    • v.21 no.5
    • /
    • pp.282-290
    • /
    • 2018
  • The onset of extreme fire behaviour in a mine drift with longitudinal ventilation was analysed. A fire in a mine drift with continuous fuel load, involving several separate fires may lead to flames tilted horizontally and filling up the entire cross section. This will lead to earlier ignition, higher fire growth rate, higher fire spread rate and a severe fire behaviour. The focus has been on what changes take place at the onset and signs of the impending phenomenon. It was found that the fire gas temperature at the ceiling level provided a poor indicator. At the downstream far-field region of the fire, the sudden temperature increase at the lowest levels of the cross section and the sudden increase in flow velocities would provide signs of extreme fire behaviour. The corresponding full-scale heat release rates of the experiments at the onset of extreme fire behaviour were found to be very high for mining applications but not necessarily for tunnel fires. The heat release rate threshold for a mine drift with smaller cross-sectional dimensions would decrease considerably, increasing the likelihood of occurrence. The distance between the fuel items will play an important role during the initiation of horizontal flames.

Fire Simulation by Pyrolysis Method of FDS for the Small Cone Calorimeter (ISO 5660) (FDS 열분해 모델을 이용한 콘칼로리미터(ISO 5660) 화재 시뮬레이션)

  • Yang, Sung-Jin;Jang, Jung-Hun;Kang, Chan-Yong
    • Proceedings of the KSR Conference
    • /
    • 2009.05a
    • /
    • pp.206-212
    • /
    • 2009
  • Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

  • PDF

A Study on Development of Korean Urban Fire Simulation (한국형 도시화재 시뮬레이션 개발에 관한 연구)

  • Koo, In-Hyuk;Yoon, Ung-Gi;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.05a
    • /
    • pp.247-248
    • /
    • 2015
  • Korea rapidly arranged urbanization and overpopulation with high growth of economy and all kinds of decrepit facilities are scattered all over the downtown. If there is a strong wind in fire, fire is rapidly increased by various fire spread factors. And Korea cannot build prediction model of urban fire combustion phenomena because there is no studies that physically explains the suitable flame phenomena for its real state. In this study, for development of Korean Urban fire Simulation on Attenuation of Radiant Heat Flux from Water Screen.

  • PDF

Fire test for interior material satisfied with the guide for the safety of rail vehicle (철도차량 안전기준을 만족하는 철도차량 내장재의 화재성능 시험)

  • Park, Won-Hee;Lee, Duck-Hee;Jung, Woo-Sung
    • Proceedings of the KSME Conference
    • /
    • 2008.11b
    • /
    • pp.2149-2153
    • /
    • 2008
  • A large-scale fire test was done for interior materials from a vehicle installed within a fire test room. The interior materials are satisfied with the Korean guide for the safety of rail vehicle. The guide has taken effect since December 2004 in Korea. Ignition source (gas burner) was increased in several controlled steps. The objectives of this test are to assess the fire performance in terms of ignition and flame spread on interior lining materials and to provide data on an enclosure fires involving train interior materials that grow to flashover. This data will be used to develop and calibrate an Fire Dynamics Simulator (FDS) model for fire growth on the interior vehicle.

  • PDF