• Title/Summary/Keyword: Gaseous extinguishing system

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A Study on Percent Agent in Pipe as a Criterion to Evaluate Limitations and Performance of Gaseous Fire Extinguishing Systems (가스계 소화설비의 제한사항 및 성능평가를 위한 배관 내 약제비율에 관한 연구)

  • Son, Bong-Sei;Kim, Hee-Woo
    • Fire Science and Engineering
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    • v.21 no.4
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    • pp.1-11
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    • 2007
  • This study aims to investigate, review, and summarize the definition, development, and applications of "percent agent in pipe", "percent of agent in pipe" which is used as a key factor in testing and evaluating the performance of gaseous fire extinguishing agents, including Halon 1301 and $CO_2$. This study also analyzes and compares the local and international standards on testing and evaluating the performance of gaseous fire extinguishing systems, as well as the results of system performance tests conducted as a part of performance evaluation and approval programs for gaseous fire extinguishing systems, especially, Korean Gaseous Fire Extinguishing System Performance Approval Program called KFI Approval. Percent agent in pipe was defined first in NFPA 12A, Standard on Halon 1301 Fire Extinguishing Systems, dating back to the 1970's. After the phaseout of Halon 1301 systems in 1994 in the developed countries, the percent agent in pipe has been widely used in Halon 1301 alternative clean agent fire extinguishing systems, both halocarbon clean agent systems and inert gas clean agent systems, as an essential criterion to assure the system design accuracy, determine the limitations and performance of a system, and to predict the system performance results accurately, especially, in association with their system flow calculations. Underwriters Laboratories has their own standards such as UL 2127 and 2166 applying percent agent in pipe in testing and evaluating the performance of clean agent fire extinguishing systems. As a part of a system performance test and approval program called KFI Approval System, Korea also has started to apply the percent agent in pipe as a key factor to test, evaluate, and approve the performance of gaseous fire extinguishing systems, including both high and low pressure $CO_2$ systems, from the early 2000's. This study outlines and summarizes the relevant UL and KFI standards and also describes the actual test resultant data, including the maximum percents of agent in pipe for gaseous fire extinguishing systems. As evidenced in lots of tests conducted as a part of the system performance test and approval programs like KFI Approval System, it has been proven that the percent agent in pipe may work as a key factor in testing, evaluating, and determining the limitations and performance of gaseous fire extinguishing systems, especially compared with the hydraulic flow calculations of computer design programs of gaseous fire extinguishing systems, and will remain as such in the future. As one thing to note, however, there are some difficulties in using the unified percent agent in pipe to determine the maximum lengths of pipe networks for gaseous fire extinguishing systems, because the varying definitions used by some of the flow calculations (not in accordance with NFPA 12A definition) make it impossible to do any direct comparison of pipe lengths based on percent agent in pipe.

Flame Extinguishing Characteristics of Clean Gaseous Agents and Effects of Additives (가스계 청정소화약제의 소화특성과 첨가제에 따른 영향)

  • Shin, Chang-Sub;Kim, Sung-Min
    • Journal of the Korean Society of Safety
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    • v.23 no.6
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    • pp.95-99
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    • 2008
  • Halon was known as a cause of the ozone layer destruction. In 1987, it was designated as one of the ozone-layer-destroying materials in the Montreal Protocol. Therefore substitutes of Halon agent has been developed including inert gas extinguish system, which is one of the most widely used fire extinguishing system. This study intended to increase the efficiency of inert gas extinguishing agent by using inert gas additives. As IG-541 shows high extinguishing power, the experiment was performed to measure the effects of gaseous additives to it. Cup-burner fire extinguishing apparatus was used with n-Heptane fuel. Among many of pure inert gaseous agents, Helium showed the most excellent extinguishing power. When Helium was added to IG-541, fire extinguishing power was increased and the concentration of oxygen in chimney also risen. By adding Helium to IG-541, the effectiveness of inert gas fire extinguishing system is able to be increased.

A Study on the Precautions Effects of the Enclosure Integrity Test for the Gaseous Extinguishing Systems: Focusing on the Power Plant (가스계 소화설비의 밀폐도 시험에 영향을 미치는 사전조치에 관한 연구: 발전소를 중심으로)

  • Kim, Young-Chul;Jo, Il-Hyun;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.29 no.1
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    • pp.60-66
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    • 2015
  • The present study was aimed to analyze enclosure integrity test, which is the performance experiment of soaking time, in a fire zone equipped with gaseous extinguishing system in an effort to find understand the effect of precaution factors upon the success of fire extinguishment. To achieve the goal of this study, it divided the fire zones of internal and external power plants into ones taking precaution measures and not taking them and then enclosure integrity test was given respectively. Therefore, this study examined the success rate if the test according to the presence and absence of the precaution measure and confirmed the failure factors, designed concentration soaking time and proportion of leakage area to total volume area by type of gaseous extinguishing system and rooms. Precaution measures were applied to the fire zones without them to confirm the increase of the success rate of enclosure integrity test. By doing so, it was found that reduced number of experiments caused by failure led to cost saving.

Influence of the Nozzle Contraction Angles of Gaseous Extinguishing Systems on Discharge Noise (가스계 소화시스템 노즐 수축각이 방출소음에 미치는 영향)

  • Kim, Yo-Hwan;Yoo, Han-Sol;Hwang, In-Ju;Kim, Youn-Jea
    • Fire Science and Engineering
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    • v.33 no.4
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    • pp.77-82
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    • 2019
  • Fire extinguishing systems are essential equipment in all indoor facilities to address unexpected fire scenarios, and appropriate fire extinguishing agent should be used depending on the place and object to protect. Among these, gaseous fire-extinguishing systems are used to protect electronic equipment. Therefore, inert gases that do not undergo chemical reactions are used mainly in those systems. On the other hand, recently, owing to the high integration of electronic equipment, there are some cases, in which large noise generated from gaseous systems damage the electronic equipment. In this study, numerical analysis of the discharge noise with various nozzle contraction angles was carried out to improve the gas fire extinguishing system. Numerical analysis was carried out using ANSYS FLUENT ver 18.1. The causes of the noise were elucidated using the swirl distribution. The noise level of the modified model was reduced by approximately 6 dB compared to the reference model, which is similar to the result of a previous study, confirming the validity of the method.

A Study on Estimating of Additional Gas for the Unencloseable Openings of The Gaseous Extinguishing Systems (가스계 소화설비의 개구부 보충량 추정에 대한 연구)

  • Jeong, Keesin
    • Fire Science and Engineering
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    • v.26 no.6
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    • pp.1-6
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    • 2012
  • There are specific indications about additional gas for the unencloseable openings of the carbon dioxide extinguishing systems. But there are no indications for other gas extinguishing systems including clean agent extinguishing systems only have the principle when it need, apply it. Therefore, this study suggested applying the equation of additional gas for the unencloseable openings of the carbon dioxide to all of the other fire suppression gas that we are use.

Fire Extinguishing Ability of Binary Gaseous Extinguishing Agents Evaluated by Cup Burner and Numerical Studies (이성분계 가스계소화약제 소화성능의 컵버너실험 및 이론적 고찰)

  • Kwon, Kyung-Ok;Won, Dong-Bin;Choi, Keun-Joo;Kim, Jong-Won;Shin, Dong-Il
    • Journal of the Korean Institute of Gas
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    • v.11 no.3
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    • pp.7-12
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    • 2007
  • The search for a new fire-extinguishing agent with all the desirable properties of halon 1301 has not been successful. To study binary gaseous extinguishing agents instead, one has to determine the extinguishing concentrations for several compositions of a given chemical in an inert gas. This process is expensive and time consuming. The fire suppression efficiencies of gas mixtures of HFC 125 and HFC 227ea with nitrogen as total flooding agents were studied by cup burner method. It was shown that addition of small amounts of those extinguishants to nitrogen can enhance the suppression effectiveness of the inert gas. As expected, the degree of synergism was highest at low concentrations of the chemical. For each binary system, extinguishing concentrations of the pure compounds and one binary data were used to predict the extinguishing concentrations for the entire range of binary composition. The predicted values were very close to experimental data.

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Flame Extinguishing Concentrations and Flue Gas Compositions of n-Heptane by Mixed Inert Gas Agents (불활성 가스계 혼합소화약제의 n-Heptane 불꽃소화농도 및 배가스 조성)

  • 김재덕;김영래;홍승태;이성철
    • Fire Science and Engineering
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    • v.16 no.3
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    • pp.77-83
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    • 2002
  • We measured flame extinguishing concentration and flue gas composition in the n-heptane fuel cup-burner system using inert gas agents such as nitrogen, argon, carbon dioxide and their mixtures. The flame extinguishing concentration of binary gaseous mixture was well predicted by model which contains the flame extinguishing concentration and composition of pure components. The higher average specific gravity of the mixed inert gas agents, the more excellent flame extinguishing performance. And the structure of enclosed space also affects the fire extinguishing. The composition of carbon dioxide in the flue gas was decreased with increasing extinguishing agent used. Nitrogen monoxide production is not related with increasing nitrogen, but increased at rapid mass flow rate of air in the cup-burner.