• Title/Summary/Keyword: Spray fire

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철골구조물의 SPRAY 내화피복의 내화성능에 관한 실험적 연구

  • 정우택;오창희
    • Fire Science and Engineering
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    • v.3 no.3
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    • pp.3-7
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    • 1989
  • The aim of this study is to provide the basic data of spray setting method for the fireproof covering. For this purpose, the purpose, the behavior of different three kinds method which is the number of thimes, interval, finishing for a required performance. The result of the data analysis shows that it is better to spray setting method at a time and to finish by natural becomes to reduce a period and labor cost for works.

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A Sensitivity Study of the Number of Parcels to the Numerical Simulation of Sprinkler Sprays (통계적 액적군집수에 따른 스프링클러 분무해석의 민감도에 관한 연구)

  • Kim, Sung-Chan;Lee, Sang-Woo;Park, Won-Ju
    • Fire Science and Engineering
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    • v.23 no.1
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    • pp.48-54
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    • 2009
  • The present study has been performed to investigate the effect of statistical number of droplets on the simulation of the sprinkler spray using fire field model. In order to simulate the sprinkler spray characteristics, the present study uses NIST Fire Dynamics Simulator version 5.2. A group of Lagrangian particles with similar droplet characteristics, such as diameter, velocity, temperature and so on, is represented by parcel concept to decrease the total number of droplets tracked in the simulation. The present study introduces a new parameter to represent the ratio between real number of droplets and computational parcels. The dependency of the number of parcels on the fire suppression characteristics and spray patterns is quantitatively examined for different ratio between the real number of droplets and computational parcels.

Directional Water Spray Characteristics of Sprinkler Heads (스프링클러 헤드의 방향성 살수 특성 비교 연구)

  • Park Yong-Hwan
    • Fire Science and Engineering
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    • v.18 no.4
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    • pp.35-41
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    • 2004
  • The water spray characteristics of the sprinkler heads is a very important factor affecting the fire suppression performance, and it is largely dependent on the shape of the head nozzle. This study investigated shape factors and spray distribution performances for the sprinkler heads of four domestic companies with big market shares. The experimental results revealed that all flow constants exceeded the required regulation limits, however showed big differences between head types although they have the same design limit. They were however relatively consistent regardless of the pressure increases. The spray distribution of some head samples showed severe directional eccentricity, which suggests more study for the improvement.

Numerical Study on the Attenuation Effect of Water Mist on Thermal Radiation (미세물분무에 의한 열복사 감쇠 효과에 대한 수치해석 연구)

  • Ko, Gwon Hyun
    • Fire Science and Engineering
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    • v.34 no.4
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    • pp.7-12
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    • 2020
  • A numerical study was conducted to investigate the effects of the spray characteristics of water mist on the attenuation of thermal radiation. The attenuation process of the thermal radiation, generated from a hot surface panel, passing through the water mist was calculated via Fire Dynamics Simulator (FDS), and the effects of the flow rate, droplet mean diameter, and spray injecting angle of the water mist were analyzed. The results indicated that the increase in flowrate and decrease in droplet size led to an increase in the attenuation of thermal radiation. As the thermal radiation passed through the spray droplets, the effect of the spatial distribution of spray droplets was verified by calculating the thermal radiation attenuation at different spray injecting angles. The results indicated that the radiation attenuation increases as the spray angle increases. This implies that a wider distribution of spray droplets, irrespective of the droplet size and flowrate, increases the attenuation effect on thermal radiation.

Numerical study on the foam spraying for AFDSS applicable to initial fire suppression in large underground spaces (지하대공간 초동 화재진압에 적용가능한 자율형 소화체계의 폼 분사 해석 기법 연구)

  • Park, Jinouk;Yoo, Yongho;Kim, Whiseong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.6
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    • pp.503-516
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    • 2021
  • Autonomous fire detection and suppression system requires advanced technology for complex detection technology and injection/control technology for accurate hitting by fire location. Also, foam spraying should be included to respond to oil fires. However, when a single spray monitor is used in common, water and foam spray properties appear different, so for accurate fire suppression, research on the spray trajectory and distance will be required. In this study, experimental studies and numerical analysis studies were combined to analyze the foam spray characteristics through the spray monitor developed for the establishment of an autonomous fire extinguishing system. For flow analysis of foam injection, modeling was performed using OpenFOAM analysis software, and the commonly used foaming agent (Aqueous Film-Forming Foam) was applied for foam properties. The injection distance analysis was performed according to the injection pressure and the injection angle according to the form of the foam, and at the same time, the results were verified and presented through the injection experiment.

Full-scale Fire Suppression Test for Application of Water Mist System in Road Tunnel (미분무수 소화시스템의 도로터널 적용을 위한 실물 화재 실험)

  • Han, Yong-Shik;Choi, Byung-Il;Kim, Myung-Bae;Lee, Yu-Whan;So, Soo-Hyun
    • Fire Science and Engineering
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    • v.25 no.3
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    • pp.51-56
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    • 2011
  • The full-scale experiments are carried out to investigate the fire suppression characteristics of water-based fire fighting systems in a road tunnel. Applied systems are the low-pressure water spray system at 3.5 bar and the high-pressure water mist system at 60 bar. The water flow rate of the high-pressure system is one sixth only of the water spray system. A passenger car and a heptane fuel pan with area of $1.4m^2$ are used as fire sources. A blower system is installed at the tunnel exit to realize the longitudinal ventilation conditions (0.9~3.8 m/s) in the tunnel. Temperatures from the fire source to the down-stream direction are measured by K-type thermocouple trees. The experimental results show that the cooling effect of the high pressure water mist system in the test conditions were equivalent to that of the low pressure water spray system for B-class fire.

An Experimental Study on the Droplet Size Distribution of Sprinkler Spray for Residential Building (주거용 스프링클러 분무의 액적크기 분포에 관한 실험적 연구)

  • Kim, Sung Chan;Kim, Jung Yong
    • Journal of ILASS-Korea
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    • v.20 no.3
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    • pp.175-180
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    • 2015
  • A series of sprinkler discharging tests was conducted to measure the droplet size and its distribution of residential fire sprinkler heads. Droplet sizes in sprinkler spray were measured using a laser diffraction method for the flush, circular and pendent type sprinkler head. In this study, the $D_{v,50}$ of the flush type sprinkler heads were ranged between $530{\sim}1040{\mu}m$ and those of circular and pendent type were $988{\mu}m$ and $916{\mu}m$, respectively. The measured cumulative volume distributions were followed by a combination of the log-normal and Rosin-Rammler distribution which is widely used in the computational fire analysis and the parameters of distribution function were obtained from the best fit line through the measured data.