• Title/Summary/Keyword: Fire Test

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Analysis of the Response Time of a Photoelectric Spot-Type Smoke Detector Depending on the Type of Fires (화원에 따른 광전식 연기감지기 반응시간 분석)

  • Jee, Seung-Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.5
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    • pp.89-94
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    • 2013
  • The fire testing performed for smoke detector model approval in Korea tests only one kind of fire smoke. A photoelectric spot-type smoke detector using Mie scattering is affected by the wavelength of light beam and the particle diameter. According to UL (Underwriters Laboratories Inc.) 268 standard, this paper analyze the characteristic of the response for a photoelectric spot-type smoke detector on sale in Korea using various fire smokes. Probability that the response time is included in non-defective range is 100% in paper fire, 90% in wood fire and 75% in flammable liquid fire, 90% in wood fire and 75% in flammable liquid fire. According to the estimation for population mean of the response time choosing a confidence level of 99%, a maximum of 19% for wood fire and that of 38% for flammable liquid fire are defective. As the result of analysis of smoke particle, this paper is found that these results are caused by the smoke particles are wide variations in size or have very black.

A Study on the Analysis of Fire Mechanisms in Electronic Products due to Failure and Malfunction of Thermostats Through Fire Cases and Reproduction Experiments (화재사례 및 재현실험을 통한 온도조절장치 고장 및 오동작으로 인한 전자제품 화재 메커니즘 분석)

  • Jeong-il Lee;Jong-Hwa Im
    • Journal of the Korea Safety Management & Science
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    • v.26 no.1
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    • pp.31-38
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    • 2024
  • In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.

A Study on the Ventilation Improvement of Diesel Locomotive Engine Load Test Building using Computational Fluid Dynamics (전산유체역학을 이용한 디젤엔진 부하시험장의 환기 개선에 관한 연구)

  • Park Duckshin;Jeong Byungcheol;Cho Youngmin;Park Byunghyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.2
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    • pp.227-242
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    • 2005
  • The aim of this study is to relieve the poor ventilation problem of the diesel locomotive engine load test building, located in an urban area. This paper evaluates the ventilation performances of the studied load test building based on the temperature measurement experiment and the computational fluid dynamics (CFD) during the engine load test. The temperature rise caused by the radiator blower of the building was turned out to be the main cause of disturbing the thermal conditions of the building. The indoor temperature distributions simulated by Fluent were validated with the temperature measurement results obtained from the studied building. The simulation results indicated that the comfort condition of this building was poor We suggested several remedial changes in the duct structure of this building for the improvement of the comfort conditions. In addition, a prototype drawing combining several improved design options was proposed. and then the simulation of the temperature distribution in the proposed prototype was performed. The result indicated that the indoor thermal condition of this proposed building was improved when compared with that of the current building.

A Study on the Ways of Securing the Effectiveness of Field Flame Retardant Coating Process (현장방염처리제도의 실효성 확보 방안에 관한 연구)

  • Park, Sung-Hyun;Baek, Eun-Sun
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.95-100
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    • 2011
  • The ultimate purpose of this study is to improve the irrational system related to flame retardant coating performance test of field flame retardant coating articles and to secure the reliability of flame retardant coating through rational flame retardant coating test. To achieve this, the analysis was conducted on the interior finishing materials used in the interior fields and the trends of recent field flame retardant coating, based on the results of flame retardant coating performance test of field flame retardant coating articles which the first-line fire stations have recently conducted. And I attempted to present the methods of field flame retardant coating performance test suitable to current realities and the ways of improvement for securing reliability by analyzing the problems with the methods and procedures of field flame retardant coating articles and the registration system of flame retardant coating business.

A Study on the Cone Calorimeter Evaluation Method of Sandwich Panels (복합자재 콘칼로리미터평가방법에 대한 연구)

  • Park, Jung-Woo;Cho, Nam-Wook
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.74-82
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    • 2017
  • Fires in buildings built using sandwich panels are difficult to extinguish, and the damage caused by the fire spreading through the inner core material is extensive. Sandwich panels consist of a nonflammable material on both sides of an insulation material. The types of insulation material include organic and inorganic insulation materials, but the former are used in more than 80% of the case. Organic insulation is economically advantageous compared to inorganic insulation, but it is vulnerable to fire. Therefore, the damage caused by sandwich panel fires is higher than that for general fires. In the case of the noxious gas analyzer test, the panel is tested with three round holes having a diameter of 25 mm, in order to determine the risk of the core material, but the cone calorimeter test is carried out using a sandwich panel. In this study, the cone calorimeter test was conducted to examine the fire risk of the composite material when heated on a nonflammable surface, exposed to the core material through a hole, and heated directly the core material. The type of organic insulation employed was flame retardant EPS (Expanded Polystyrene), and the test specimens were tested in three types of sandwich panel, a perforated sandwich panel and single core material. The purpose of this study is to propose a method of measuring the fire risk of the core materials of composite materials using the cone calorimeter test.

The Ways of Improving Technical Standards to Increase Effectiveness of Wetting Agent (침윤소화약제의 효과성 증대를 위한 기술기준 개선방안)

  • Jang, Kwan Su;Kim, Jung Min;Cho, Young Jae
    • Journal of the Society of Disaster Information
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    • v.18 no.3
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    • pp.581-588
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    • 2022
  • Purpose: This study is about offering ways of improving existing technical standards in order to propose how to deal with coal deep-seated fire and to increase effectiveness of wetting agent. Method: This study conducts infiltration experiment using eight tons of coal, three types of wetting agents and fire water. And this study analyzes domestic and international technical standards, overseas experimental cases. Result: It is found that two findings are identified; one is fire water cannot infiltrate into the coal due to high level of surface tension, and the other is three types of wetting agent can infiltrate into the coal to the depth of 5~25cm. Also, domestic wetting agent technical standards include measuring surface tension only and testing wood on extinguishing capacity test. On the other hand, this study found that deep-seated fire experiment using cotton, B-class fire test using heptane are used from abroad. Besides it is analyze that capillary rise test, sink test, contact angle measurement are conducted to increase effectiveness of wetting agent at the U.S. Bureau of Mines. Conclusion: Based on standards and cases of U.S. NFPA and Bureau of Mines, this study suggests that domestic technical standards should include adding a new test standard which measures infiltration directly.

A Study on the Necessity of Introducing Evacuation Instrument in High-rise Buildings - Focusing on Elevator Type Evacuation Instrument - (고층건축물의 피난기구 도입 필요성에 관한 연구 - 승강식피난기를 중심으로 -)

  • Choi, Kyu-Chool;Ra, Pan-Ju;Seul, Yeong-Mi
    • Fire Science and Engineering
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    • v.28 no.3
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    • pp.10-19
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    • 2014
  • The fast evacuation from fire floors to evacuation floors in high-rise building fires can minimize the human damage. In this study, an evacuation instrument, which are applicable to the high-rise buildings of adaptable escape mechanisms by the current NFSC 301 (national fire safety code 301), were selected to analyze the applicability in the high-rise buildings over 11th floor through the site adaptability test. The results of the site test were as follows. The elevator type evacuation instrument of new concept developed as a new technology by compensating the defect of evacuation instrument limiting in the high-rise buildings over 11th floor had completed the stability test and the performance certification test in fire stations, which there were no problems in the introduction of the elevator type evacuation instrument as an escape mechanism in the high-rise buildings. The elevator type evacuation instrument using escapers' weight without using electric power was an escape mechanism that many people could evacuate in a short period of time when a fire broke out in the high-rise buildings. In particular, The elevator type evacuation instrument operated by nonpower had the adaptability as a customized escape mechanism considering user characteristics in the buildings for the disabled or patients with an advanced disease.

Investigation of the Fire Source in the Warehouse under Bridge using FDS Code (FDS code를 이용한 교량하부창고 화재발생원 영향분석)

  • Zi, Goang-Seup;Lee, Seung-Jung;Shin, Yeon-Ho;Shim, Jae-Won;Kim, Ji-Hwan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.6
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    • pp.663-673
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    • 2011
  • In this study, we analysed the effect of the fire source in the warehouse under the bridge and the height of the bridge using FDS code. To compare accuracy of simulation results, we simulated the experimental result with unit combustibles which is heptane as well as the mock-up test. Using this method, we evaluated the fire safety of the bridge which contains spalling and strength damage of concrete as well as damage of reinforcements according to the fire source and the height of the bridge. Most of the bridges are vulnerable to spalling of concrete. The book combustion has the strongest fire intensity which is expected to damage the bridge less than 30m height in the three types of the fire sources. The bridge over the 30m height can ensure the fire safety in the case of the rubber combustion.

An Experimental Study on Structural Behaviour of Asymmetric H Beam Slim floor under Load Condition in Fire (내화 피복된 비대칭 H형강을 적용한 슬림플로어 보의 재하가열조건 화재거동에 관한 실험적 연구)

  • Kim, Hyung-Jun;Kim, Hyung-Jun;Min, Byung-Youl;Lee, Jae-Sung;Park, Soo-Yong
    • Fire Science and Engineering
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    • v.25 no.1
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    • pp.63-71
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    • 2011
  • When it comes to slim floor using asymmetric H-beam, it was designed that the steel member is embedded in concrete with relatively low thermal conductivity so as to minimize the deterioration of rigidity of steel member in fire. But given the bottom flange of asymmetric H-beam is directly exposed to the fire, the measure of applying the fireproof coating to improve the fire rate performance of slim floor beam was sought. The test was aimed at comparing the fireproof performance by adjusting the load ratio of 0.4 and 0.3, and The test was carried out to identify the 3-hour fire performance by reinforcing the beam as well as applying the fireproof coat, In the wake of comparing the specimen depending on variation of load ratio, lowering load ratio by 0.1 resulted in difference of 12 minutes and deflection was 39 mm. It was able to improve 12 minutes by reinforcing the beam and up to 102.4 mm in deflection.

Prediction of Temperature Distribution to Evaluate Axial Strength of Unprotected Concrete-filled Steel Tubular Columns under Fire (화재 시 무피복 CFT 기둥의 축강도 평가를 위한 단면온도분포 예측기법의 개발)

  • Koo, Cheol Hoe;Lee, Cheol Ho;Ahn, Jae Kwon
    • Journal of Korean Society of Steel Construction
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    • v.25 no.6
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    • pp.587-599
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    • 2013
  • A simple but accurate analytical method to evaluate the fire resistance of unprotected concrete filled tubular (CFT) columns under standard fire condition is proposed based on the fire design framework of EC4. To this end, the accuracy of the current tabulation method for the temperature prediction proposed by Lawson et al. was first critically evaluated, and a new prediction equation for the temperature gradient across the CFT section was then proposed based on available test and finite element analysis results. Overall, the axial strength predicted by using the proposed equation under the general fire design framework of EC4 was more accurate than that based on existing methods and appeared reasonable for design purposes. The results of this study are directly usable for the more rational fire analysis and design of unprotected CFT columns.