• Fire Science and Engineering
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• v.16 no.2
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• pp.59-69
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• 2002

The conventional fire extinguishing gas-agent system has a configuration in which the gas-agent comes out of a cylindrical container having vertically settled shape. However, in this study a horizontally installed container of a piping shape having a cylinder of the same shape with a cylinder valve and a discharge nozzle was used, and the relationship between orifice size of nozzle and discharge rate of gas-agent was investigated through various experiments including the measurement of discharge rate under different ambient-temperature conditions. In such experiments, HCFC Blend A was used without super-pressurization by nitrogen. From this research, it was observed that statutory discharge duration of 10 seconds can be met if the relatively large size of the valve and the nozzle orifice were properly selected.

• Fire Science and Engineering
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• v.26 no.6
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• pp.15-23
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• 2012

Indirect Test Method is often used instead of direct test method in test method for extinguishing performance of $CO_2$ extinguishing facility because of high cost, environment problems and difficulties of procedure. But in the danger facilities for a unit of nation, such as a petrochemical plant, a nuclear power plant, or etc. is better to verify the performance of the extinguishment through direct discharge test. In $CO_2$ extinguishing system for total flooding system installed in dangerous facilities in Korea, each protected area in surface fire and deep-seated fire had selected and verified of extinguishing performance of $CO_2$ extinguishing facilities. To get recognized as extinguishing performance, discharged $CO_2$ concentration to protected area should be equivalence with design concentration standards (NFSC and NFPA). The Design Concentration means that $CO_2$ extinguishing agent is considerate of concentration for percentage of allowance (20 %) from extinguishing concentration which available to control of flame. As test result, surface fire and deep seated fire in protected area is obtained $CO_2$ design concentration and maintained design concentration more than 20 minutes as deep-seated fire. Through this study, we introduced direct discharging test method and decision method. And furthermore, especially in the dangerous facilities as a unit of Nation, we suggested necessity about reliability of extinguishing facilities to use direct test method.

• Fire Science and Engineering
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• v.27 no.6
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• pp.8-14
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• 2013

This research is to evaluate the fire extinguishing performance at a mixing ratio of pressurized air in the fire extinguishing system of compressed air foam (CAF) which injects compressed air into foam liquid and then discharging. The experimental device is made use of exclusive foam extinguishing facility for compressed air foam that is produces based on Canada National Laboratory and UL 162 standard, apply model of oil fire (B Class) 20 unit in accordance with "Standard of Model Approval and Product Inspection for Fire Extinguishing Agent" to the fire Extinguishing model. Compressed air is injected through the air mixture and study the tendency depending on increasing air foam ratio 1 : 4, 1 : 7, 1 : 10. In addition, the comparison experiments between synthetic surfactants foam and AFFF carry out with it at the air foam ratio 1 : 4. As a result, in the condition of same discharging flow, fire extinguishing effect of AFFF is the fastest at the air foam ratio 1 : 7 and the slowest at 1 : 10. Moreover, the fire extinguishing effect of AFFF in the comparison expeiments between AFFF and synthetic surfactants foam is faster than the other.

• Journal of Korean Institute of Fire Science & Engineering
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• v.1 no.1
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• pp.2-9
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• 2000

• Fire Science and Engineering
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• v.32 no.5
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• pp.22-33
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• 2018

The amount of halogen clean fire extinguishing agents has been increased by the excellent features of extinguishing, adaptability and no residue. On the other hand in situations without a hazard assessment and safety standard of agents, chemical accidents by the agents occurs frequently. This study was performed to propose the halogen clean agents' regulatory exposure limit and safety standard including the quantitative ventilation system with gas leak monitoring, hazard recognition and optimal personal protection selection through a literature review and experimental research.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2006.04a
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• pp.247-252
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• 2006

• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.20-25
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• 2012

The purpose of the study is to assess the extinguishing concentration of inert gases in engine nacelle fire. The experiment was performed with a two dimensional rectangular bluff body stabilized flames, where the fuel was ejected to counter flow and co-flow against an oxidizer stream. Two inert gases, $CO_2$ and $N_2$, were used for extinguishing agent in the oxidizer and methane was used for fuel. The main experimental parameters were the direction of injecting fuel, the kinds of agent and the velocity ratio between air and fuel streams, which controlled the mixing characteristic near bluff body and the strength of recirculation zone in the downstream. The result shows the flame structure and the mode were strongly dependent with fuel/air ratio and the fuel jet direction. For both flow configurations, the extinguishing concentration of $CO_2$ was smaller than the $N_2$ because of the large heat capacity of $CO_2$. However, the concentration of inert gasesat blowout was much smaller than those in the cup burner and coflow jet diffusion flames, which implies that the extinction mechanism of bluff body stabilized flames was mainly due to the aerodynamic aspect. Compared to co-flow fuel injection, the extinguishing concentration of inert gases under counter flow configuration was lower. The effect of direction might result from the mixing characteristic and strength of recirculation zonearound a bluff body. More details should be investigated for the characteristic of recirculation zone in the wake of bluff body using the LES(Large Eddy Simulation).

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.6
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• pp.655-667
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• 2020

The final purpose of this study is to present the performance evaluation criteria (draft) of the autonomous initial suppression digestion system. In this study, in order to present the performance standards for the autonomous initial suppression fire extinguishing agent system currently in the development stage, the legal performance standards for fire extinguishing equipment currently applied to domestic buildings and the performance standards of similar overseas previous research were compared and analyzed. In addition, based on this, the minimum performance standards required for the digestive system for autonomous initial suppression were presented. When the performance of the digestive system for autonomous initial suppression is evaluated based on the results of this study and applied, it is judged that it is possible to respond more quickly in the situation of fire.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.542-549
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• 1997

HFC-227ea and HCFC Blend A were evaluated using full-scale fire tests to obtain information on their fire suppression performance, drop-in capability, thermal decomposition products and physical behaviour of the agent such as its flow characteristics in the piping system. Also, full-scale tests were conducted with Halon 1301 to provide a basis for comparison. Halon 1301, at concentrations of 5% to 7.5%, showed effective total-flooding fire- extinguishing performance for all test scenarios. HFC-227ea, at a design concentration of 7.6% or higher, and HCFC Blend A, at a design concentration of 12%, extinguished all fires in the test facility, however, these agents produced higher concentrations of acid gases than Halon 1301. The quantity of the acid gases generated during fire suppression was dependent on agent concentration, agent discharge time, fire type and size as well as extinguishment time.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.74-79
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• 2013

As the feature of fire, it is hard for deep-seated fire to spread to the deeper site, and it also has danger for being re-ignited cause of recontacting with oxygen after being put off. Now it is ruled in the certification criteria of wetting agent used for extinguishing deep-seated fire that the criteria for surface tension is below 33[mN/m] in Korea. For figuring out how much water for fire-fighiting can permeate into combustibles, in this research, the permeating performance is analyzed by measuring the speed of permeating and transmission quantity released after that, by pouring solution whose surface tension is changed by adjusting concentration of surfactant BDG(Butyl Di Glycol) in column From this result, it is can be determined that transmission quantity becomes less and wet area goes wider as surface tension is lower, and it is also able to be analyzed as quantity of absorbed liquid and wet area is increased because fluid permeates into the core.