• Title/Summary/Keyword: 가연

Search Result 482, Processing Time 0.029 seconds

Fire Characteristics of Flaming and Smoldering Combustion of Wood Combustibles Considering Thickness (목재 가연물의 두께에 따른 화염연소와 훈소상태에서의 화재특성)

  • Kim, Sung-Chan;Nam, Dong-Gun
    • Fire Science and Engineering
    • /
    • v.29 no.4
    • /
    • pp.67-72
    • /
    • 2015
  • A series of fire tests was conducted to examine the fire characteristics of flaming and smoldering combustion of engineered wood products, which have been widely used for furniture and finishing materials in buildings. The engineered wood products of MDF, plywood, and chipboard were ignited by a radiant cone heater with incident heat flux of $50kW/m^2$. During the fire test, key parameters representing the fire characteristics such as the heat release rate, yield rate of combustion product, and effective heat of combustion were quantified in terms of thickness. The tests show two peak points of HRRPUA due to lateral fire propagation in the initial stage, followed by later fire penetration through the specimen thickness. The mass loss rate of flaming combustion was 5 times higher than that of smoldering combustion, while the CO yield rate of smoldering combustion was 10 times higher than that of flaming combustion. This study can contribute to the understanding of fire behavior of wood combustibles and provide useful data for fire analysis.

An Experimental Study on the Fire Risk at Welding·Cutting Process (용접·절단 작업시 화재위험성에 관한 실험적 연구)

  • Lee, Sung-Ryong
    • Fire Science and Engineering
    • /
    • v.26 no.3
    • /
    • pp.60-66
    • /
    • 2012
  • In this study, it was evaluated the fire risk during welding cutting tasks. Welding-cutting machines are representatively used at construction sites. Inverter AC/DC TIG welding macnine and inverter air plasma cutting machine were used in experiments. Temperature of spreaded cinders was measured using a thermal camera. Cinder sizes and spread range were measured according to the height and input current. It was also evaluated the fire risk during welding-cutting process, when flammable materials were located around the working area. There were used hay, dust fence, urethane foam, vinyl, paper and oil as flammable materials. Temperature of spreaded cinders was reached at about $450^{\circ}C$. Cinders were spread approximately 4.7 m, when a worker carried out cutting process at 2.5 m height. The possibility of a fire is very high, when flammable materials were located around the working area.

Evaluation of Design Fire Curves for Single Combustibles in a Cinema Complex (복합영상관 단일 가연물의 디자인 화재곡선 평가)

  • Jang, Hyo-Yeon;Hwang, Cheol-Hong;Oh, Chang Bo;Nam, Dong-Gun
    • Fire Science and Engineering
    • /
    • v.34 no.3
    • /
    • pp.18-27
    • /
    • 2020
  • An actual fire test was performed on single combustibles placed in a local cinema complex, and quantitative differences in the maximum heat release rate (HRR) and fire growth rate were investigated based on the design fire curve methods (i.e., the general and 2-stage methods). In terms of combustible use and fire load, a total of 12 combustibles were selected, classified into cinema lounge and movie theater. It was found that the maximum HRR and fire growth rate determined using the two-stage method were quantitatively different from those of the general method. The application of the two-stage method, which can be used to determine the fire growth rate of the initial fire stage more precisely, could be useful in accurately predicting the activation time of fire detectors and fire-extinguishing facilities, as well as the available safe egress time (ASET) and required safe egress time (RSET).

Effects of the Recess and Propellants Mass Flow on the Flammability Limit and Structure of Methane-Oxygen Diffusion Flame (인젝터 리세스와 추진제 공급유량이 메탄-산소 확산화염의 가연한계와 구조에 미치는 영향)

  • Hong, Joon Yeol;Bae, Seong Hun;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.22 no.1
    • /
    • pp.28-35
    • /
    • 2018
  • In order to analyze the flammability limit and structure of the gaseous methane-gaseous oxygen diffusion flame formed through a shear coaxial injector, combustion experiments were carried out according to the condition of injector recess and propellant mass-flow rate. As a result, it was confirmed that stable anchored flame was observed even at the high oxygen Reynolds number as the propellant momentum flux ratio increased, and that the recess had no significant influence on the flame shape and flammability limit. The anchored flame visualized through a chemiluminescence showed the maximum OH radical emission intensity at a specific position, irrespective of the propellant injection condition, and the radical intensity was greatly reduced by the injector recess.

An Experimental Study on the Fire Risk of Electric Heaters According to Contact of Flammable Materials (가연물 접촉에 따른 전기히터의 화재위험성에 관한 실험적 연구)

  • Lee, Sung-Ryong
    • Fire Science and Engineering
    • /
    • v.25 no.3
    • /
    • pp.63-71
    • /
    • 2011
  • In this study, it was evaluated the fire risk of an electric heater as representative seasonal appliances. Two type of electric heaters were used in experiments. When electric heaters were operated, temperature variation was measured around the heater. Internal structure was understood by Nondestructive inspection. It was evaluated the tire risk of electric heaters, when flammable materials were positioned ear a heater. It was also estimated the probability of a tire in case of malfunction of a safety tip-over witch. When a heater was operated in a normal condition, temperature was maintained under $80^{\circ}C$ around the heater. The possibility of a fire is very high, when a heater is covered with flammable materials or malfunction of safety parts (safety tip-over switch, anti-overheating devices).

The Study on Fire Characteristics of Furniture (가구류에 대한 화재 특성 연구)

  • Kweon, Oh-Sang;Yoo, Yong-Ho;Kim, Heung-Youl;Lim, Young-Soo
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
    • /
    • 2009.04a
    • /
    • pp.379-384
    • /
    • 2009
  • 본 연구에서는 다세대 주택에서 발생되는 화재에서 가연물질이 되는 가구류에 대한 화재 특성을 파악하기 위해 단위 가연물에 대한 열방출율(HRR, Heat Release Rate), 연기발생량, 유독가스 발생량 등에 대한 기본 DB를 확보하고자 하였다. 실험에 사용된 단위가연 물에는 침대(매트리스 포함), 장롱, 화장대, 책상, 책장, 소파(3+1인용), TV, 싱크대(찬장포함), 냉장고, 이불(옷가지)등 총 12여종이며, 국제 시험 규격인 ISO 9705 시험법인 중규모 시험 장치(Room Corner Tester)와 10MW 급의 실규모화재실험장치(Large Scale Calorimeter)에서 실험을 진행하였다. 실험결과 냉장고에서 가장 높은 최대 열방출율 약 3051 kW, 장롱에서의 일산화탄소 방출량은 최대 약 3894.2 ppm, 이산화탄소의 방출량은 최대 약 1.8% 로 가장 높게 측정되었다. 이러한 중규모 시험 장치를 통한 단위 품목의 화재특성 DB 작성은 단위구획에서의 화재 확산 예측에 가장 중요한 요소가 될 수 있을 것이다.

  • PDF