• Title/Summary/Keyword: 임계 열유속

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A Study on Evaluation Methods for the Fire-retardant Performance of Hanok Components (건축 마감재의 화재안전기준 비교분석을 통한 한옥 부재의 난연성능 평가기준 연구)

  • Kwark, Ji-Hyun;Choi, Jung-Min;Ku, Jae-Hyun
    • Fire Science and Engineering
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    • v.25 no.5
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    • pp.1-7
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    • 2011
  • In this study, standards and test methods for building materials of domestic and foreign countries were compared and analyzed to propose evaluation methods for the fire-retardant performance of HANOK components (Traditional house). IBC and NFPA codes recently have been adopted in the US, and the properties such as critical heat flux, fire spread index and smoke density are being used as an evaluation reference. In Europe, the unified Euroclass has been adopted and the surface flammability, prototype fire test or cone calorimeter test are conducted for the performance test. Japan has the similar system as Korea where the class is classified into 3 grades. We tried to study a quantitative evaluation method of fire retardant performance for the HANOK components based on the analysis results of the several countries' standards and test methods for building materials.

The Effect of the Fill Charge Ratio on the Heat Transfer Characteristics of a Two-Phase Closed Thermosyphon (충전율의 변화가 밀폐형 2-상 열사이폰의 열전달 특성에 미치는 영향에 관한 연구)

  • Park, Yong-Joo;Hong, Sung-Eun;Kim, Chul-Ju
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.12
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    • pp.1646-1654
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    • 2002
  • A two-phase closed thermosyphon was one of the most effective devices in the removing heat because of its simple structure, thermal diode characteristics, wide operating temperature range and so on. In this study, a two-phase closed thermosyphon(working fluid PFC(C6F14), container copper(inner grooved surface)) was fabricated with a reservoir which can change the fill charge ratio. The experiments were performed in the range of 50~600W heat flow rate and 10~70% fill charge ratio. The results were compared with some correlations that were presented by Rohsenow and Immura et al. in the evaporator, by Nusselt, Gross and Uehara et al. in the condenser and by Cohen and Bayley, Wallis, Kutateladze and Faghri et al. in heat transfer limitation etc.. The heat transfer coefficient at the evaporator increased with the input power. However the effect of the fill charge ratio was nearly negligible. At the condenser, it showed an opposite trend to the evaporator and with increase of the fill charge ratio, showed some enhancement of heat transfer. The heat transport limitation was occurred by the dry-out limitation for small fill charge ratio(10%) and presented about 100W. For the case of large fill charge ratio(Ψ$\geq$40%), it was occurred by the flooding limitation at about 500W.

Comparison on the fire performance of additional insulation materials for improving the fire retardancy in engine-room of FRP vessel (FRP 선박 기관실 난연성 향상을 위한 추가 방열재의 화재성능비교)

  • Choi, Jung-Min;Um, Han-Chan;Jin, Young-Hwa
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.9
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    • pp.1150-1155
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    • 2014
  • To prevent the flame spread in FRP vessel in fire, the engine-room of the vessel should be constructed additionally with laminated fire-retardant resin over 3 times or equivalent insulation materials to former according to the relevant standard for FRP vessel structure. It is surveyed that insulation materials called 'Gel coat' are widely used in FRP fishing vessel, however, test method and its criteria for Gel coat are not clearly establish and have not been evaluated yet, while test method and criteria for fire-retardant resin and fire-retardant polyurethane composite are described in test standard for type-approval. In this study, 3 fire-retardant resins, 4 gel coats, 1 flame-retardant paint and 1 polyurethane composite were selected based on the survey and were evaluated according to both IMO FTP Code part 5 and flame-retardant test. When comparing based on CFE values from flame-spread test, average value for 4 gel coats were lower than that of 3 fire-retardant resins. As for flame-retardant test, there were no significant differences between fire-retardant resin and gel coat, based on charred area.