• 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.

• Fire Science and Engineering
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• v.15 no.4
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• pp.41-48
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• 2001

Halogen-based fire suppressing agents have been the most effective fire suppressants and widely used for flammable liquid and electric fire. However they have environmental problems causing stratospheric ozone depletion and globe warming. As a substitution of halon, fire suppression system using fine water mist is one of an effective fire suppressant. Suffocating and cooling effects of water mist are increased by the evaporation characteristics because it has droplet size less than 1,000 $\mu{m}$ and very large surface area. In this study, the extinguishing characteristics of fire was measured with changing of water mist droplet size, flow density; discharge pressure, and fire size. As a result, the extinguishing time of pool fire was shortened with the increase of flow density and in case of low flow density less than 0.5$\pm$0.05 ml/$\textrm{cm}^2$ . min, the extinguishing time was shortened with the increase of droplet size. The cycling discharge was effective for $\eta$-heptane pool fire, and total amount of water mist required to extinguish fire was reduced to a quarter compare with continuous discharge.

• Fire Science and Engineering
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• v.26 no.5
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• pp.85-91
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• 2012

This paper analyzed firefighting officers' use situations such as the use time, maximum working pressure, hose diameter, etc. of fire pumps at fire sites and carried out various performance tests by pressures, hose diameters and quantities of fire pumps based on its results because the waterproof performance criterion for a fire pump installed in a fire engine is different from the operation situations at the site and is not clearly prescribed. As a result of site survey, the site uses a higher pressure than the standard water discharge pressure (0.85 MPa) or the high-pressure water discharge pressure (1.4 MPa) prescribed by the approval Standard of the fire pump performance on fire truck. In addition, as a result of pump performance test, the discharged water flow rate, water discharge pressure, etc. was measured to be very different from the currently prescribed the approval standard depending on the hose diameter and firefighting nozzle, so the result of this study proposes a new standard.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.269-274
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• 1997

A large scale fire experiment was conducted through the collaboration between the Tokyo Fire Department and the National Research Institute of Fire and Disaster (NRIFD) for the purpose of studying the effectiveness of aerial fro fighting against urban fire. Ten model houses and ten collapsed model houses were arranged in an area of about $2,000\;m^2$. Water was dropped totally fourteen times by helicopters onto the model houses. In order to know influence of water drop, radiation was measured by four radiometers and four IR (Infrared) cameras, which were set around the burning area. In this report, the influence of aerial Ore fighting on fire was discussed in terms of irradiance and IR images. Data of irradiance, flame temperature and flame area showed that influence of each water drop continued only at most a minute.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2983-2988
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• 2007

In the present study, the numerical investigation on the effects of water-mist characteristics has been carried out for the fire suppression mechanism. The FDS are used to simulate the interaction of fire plume and water mists, and program describes the fire-driven flows using LES turbulence model, the mixture fraction combustion model, the finite volume method of radiation transport for a non-scattering gray gas, and conjugate heat transfer between wall and gas flow. The numerical model is consisted of a rectangular enclosure of $L{\times}W{\times}H=1.5{\times}1.5{\times}2.0m$ and a water mist nozzle that be installed 1.8m from fire pool. In the study, the parameters of nozzle for simulation are the droplet size and the spray velocity. Finally, the droplet size influences to fire flume on fire suppression than spray velocity because of the effect of terminal velocity, and the optimal condition for fire suppression is that the droplet size and the spray velocity are $100{\mu}m$ and 20m/s, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.12
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• pp.1591-1599
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• 2004

A series of experiments were conducted to study the effectiveness of the extinction of a liquid pool fire with two different water atomizing nozzles. Fire source is a small-scale circular stainless steel pan of 120mm in diameter with the fuels of hexane and ethanol. K-type thermocouples were used to measure the flame and fuel temperature along the pool centerline and under fuel surface. A digital camera was used to visualize the process of the fire suppression. The experimental results show that water mist droplet size is l15∼180${\mu}{\textrm}{m}$ with nozzle A and 130∼190${\mu}{\textrm}{m}$ with nozzle B. The extinguishing time of pool fire was reduced with the increase of pressure. When water droplets are small, they do not reach the flame base since they may be deflected or evaporated by the fire plume. However, influence of flow rate is more important than droplet size on fire extinction. Among the fire extinction mechanisms, drop of flame temperature is superior to suffocation of $O_2$ concentration.

• Journal of ILASS-Korea
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• v.22 no.4
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• pp.175-184
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• 2017

The numerical investigation on the effects of water-mist characteristics has been carried out for the fire suppression mechanism. The FDS are used to simulate the interaction of fire plume and water mists, and program describes the fire-driven flows using LES turbulence model, the mixture fraction combustion model, the finite volume method of radiation transport for a non-scattering gray gas, and conjugate heat transfer between wall and gas flow. The numerical model is consisted of a rectangular enclosure of $L{\times}W{\times}H=1.5{\times}1.5{\times}2.0m^3$ and a water mist nozzle that be installed 1.8 m from fire pool. In the present study, the parameters of nozzle for simulation are the droplet size and the spray velocity. The droplet size influences to fire flume on fire suppression more than the spray velocity because of the effect of the terminal velocity. The optimal condition for fire suppression is that the droplet size and the spray velocity are $100{\mu}m$ and 20 m/s respectively.

• Journal of TMJ Balancing Medicine
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• v.1 no.1
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• pp.23-27
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• 2011

This study reviews and suggests the followings: 1) The balance and harmony between water and fire (ki and blood, yin and yang) is regarded as the basic condition of maintaining health in Oriental medicine. 2) Oriental medicine defines disease as the imbalance or disharmony of body. So the discordance between water and fire is in ill state, the coordination between water and fire is in healthy state. 3) Etiological factors and pathology are summarized by the conflict between vital ki and pathogenic factors, six exogenous factors, internal injury by seven emotions and the imbalance between yin and yang. 4) The regulation of meridian ki recovers the balance between water and fire, ki and blood using acupuncture, moxibustion, cupping therapy, herbal medicine and physical and breathing exercise and massage which is based on the principle of controlling ki and spirit.

• Fire Science and Engineering
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• v.23 no.2
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• pp.96-100
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• 2009

Because of dense forests and restriction of approaching for fire fighters, forest fire is easy to be a larger fire in Korea. For this result, the air attack was about 90% of extinguishing, so the application of aircrafts, especially helicopters, will be increased gradually. In the all process of forest fire attack, the method of heli-scattering water was the chief element of success of efficient forest fire attack and safe flight. Therefore, a standardized method of heli-scattering water was required. However, as it was not already standardized, a efficiency and safety of fire fighting have been decreased. In this study, we suggest a 11 patterns of methods for scatterling water based on a actual experience of air attack.

• Fire Science and Engineering
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• v.23 no.5
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• pp.84-89
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• 2009

In this study, the fire extinguishing experiment was performed using a water mist nozzle with variation of factors which affect on the extinguishing time. The variables were distance from nozzle center to fire location, droplet size, height of nozzle and opening or not. With the experimental data, interaction and sensitivity between factors were analysed with Mini tab and deduce a optimum model of fire extinguishing of water mist system. Based on the experiment and modeling of fire extinguishing with water mist system, the most important factor on extinguishing time is the distance from the center of nozzle to fire and the opening effect was small compare with other factors.