• Title/Summary/Keyword: Heat Release

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Experiments on the Behavior of Underground Utility Cable in Fire (지하구 케이블의 연소특성 실험)

  • 박승민;김운형;윤명오
    • Fire Science and Engineering
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    • v.16 no.2
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    • pp.75-80
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    • 2002
  • In this paper, some experiments of a heat release rate and toxicity for underground utility 22.9kv cable in fire was conducted and analysed applying plume equation and smoke chamber test separately, A 22.9 ㎸ power cable is selected for testing heat release in ISO 9705 geometry and toxicity production is measured with NES 713 (British-Naval Engineering Standard)test. In test results, Cable heat release reached about 60 ㎾ above 1.2 m from heptane pan and CO generated lethal concentration under 30 min. exposure condition.

Characteristics of High-Frequency Combustion Instabilities Occurring in Combustion Devices (연소장치에서 발생하는 고주파 연소 불안정 특성)

  • Seo, Seong-Hyeon
    • Journal of the Korean Society of Combustion
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    • v.17 no.1
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    • pp.30-36
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    • 2012
  • Dynamic characteristics of combustion occurring in various combustion devices have been extensively studied since most of high-performance combustion devices are susceptible to hazardous, unstable combustion that deteriorates combustor's lifetime. One of the most severe unstable combustion phenomena is high-frequency combustion instability in which heat release fluctuations from combustion are coupled to resonant modes of the combustor. Here in this study, characteristics of high-frequency combustion instabilities observed in three different combustion devices have been presented. Lean-premixed combustion instability occurs mainly due to equivalence ratio fluctuations which induce large heat release oscillations at lean conditions. Liquid-fueled combustion also shows high-frequency instability from energy coupling between pressure and heat release oscillations.

Flow Characteristics of Fire Whirl for Different Heat Release Rate (발열량의 차이에 따른 Fire Whirl의 유동특성)

  • Bae, Sung-Yong;Sung, Kun-Hyuk;Ryou, Hong-Sun;Hong, Ki-Bae;Kim, Dong-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.609-613
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    • 2008
  • The fire whirl occurring by the instability of atmosphere is a rare phenomenon, but highly destructive because it has high inhalation and lift force, caused by the rotating velocity. And it is difficult to extinguish the fire, because of increment of the spread rate with the flame height. In this study, for investigation of the flow characteristic of fire whirl for various heat release rate, numerical analysis is performed in same conditions with experiments, using the FDS which is developed at NIST. For validating of the numerical study, the results are compared with the experiment. The result shows that the relation between the characteristic length and the ratio of circulation versus the buoyancy force is $z_f$/D$^{\ast}$ = 0.304(${\Omega}/{\alpha}$)^2 - 1.334${\Omega}/{\alpha}$ + 5.516.

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A Study on the Combustion Characteristics of Methane-air Mixture in Constant Volume Combustion Chamber (정적 연소실내의 메탄-공기 혼합기의 연소 특성에 관한 연구)

  • 이창식;김동수;오군섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.4
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    • pp.201-209
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    • 1996
  • This study describes the combustion characteristics of methance-air mixture with various equivalence retio and initial conditions of mixture in constant volume combustion chamber. Combustion characteristics of methane-air mixture such as combustion pressure, combustion temperature, and heat release were investigated by the measurement of combustion pressure and temperature in the combustion chamber. The results show that maximum combustion pressure, gas temperature and rate of heat release have peaks at equivalence ratio of 1.1. Combustion duration is also the shortest at the equivalence ratio of 1.1 and it is shortened as initial mixture temperature increases.

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Combustive Properties of Ethylene-Propylene Die Monomer/Polypropylene/Clay Nanocomposites (에틸렌-프로필렌 디엔 단량체/폴리프로필렌/클레이 나노복합체의 연소성)

  • Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.190-195
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    • 2011
  • Effects of ethylene-propylene diene monomer (EPDM)/polypropylene (PP), zinc oxide, stearic acid, and clay on the combustive properties based on EPDM/PP were investigated. The EPDM/PP/clay nanocomposites was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). It was found that the combustive properties in the nanocomposites decreased due to the fire resistance compared with unfilld EDPM/PP. The nanocomposites showed the lower peak heat release rate (PHRR) than that of virgin EPDM/PP, while stearic acid for softening ruber increased the mean heat release rate (MHRR) by itself, combustible.

Combution characteristics analysis of partition materials on public toilets (공공화장실 칸막이 재료의 연소특성 분석)

  • Chae, Hak-Byeong;Min, Jeong-Gi;Lee, Sang-Gwon;Jeong, Guk-Sam;Won, Jeong-Hun
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2013.11a
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    • pp.178-179
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    • 2013
  • 본 연구에서는 현재 사용되고 있는 건축물 내의 화장실 칸막이 재료를 대상으로 ISO 5660-1 콘칼로리미터(Cone calorimeter) 실험을 실시하여 대상 실험 재료들의 연소 특성을 비교 평가 하였다. 모두 5종류의 실험체를 사용하였으며, 화재 발생시 연소 중요 평가항목인 착화시간(Time to ignition), 총 방출열량(Total heat release), 최고 열방출율(Peak heat release rate), 평균 열방출율(Mean heat release rate)을 중점적으로 평가하였다. 실험결과, 착화시간은 일반 합판패널에서 빠르게 일어났으며, 총 방출열량, 최고 열방출율, 평균 열방출율은 고밀도 압축패널에서 높게 나타난 것으로 분석되었다.

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Detailed Spectroscopic Measurements of Chemiluminescence from Turbulent Premixed Flames in a Dump Combustor

  • Santavicca, D.A.;Lee, Jong-Guen
    • Journal of the Korean Society of Combustion
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    • v.9 no.3
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    • pp.19-26
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    • 2004
  • This paper presents results of experimental study of flame chemiluminescence from turbulent premixed flames in a dump combustor. A detailed spectroscopic measurement of chemiluminescence over the wavelength of 405-495 nm is made for various flow conditions. No effect of turbulence on the relationship between chemiluminescence and heat release is found, suggesting the overall chemiluminescence intensity collected be used as a measure of overall heat release for non-oscillating stable flame. The background-$CO_2^*$ subtracted $CH^*$ chemiluminescence is found to be more sensitive to the equivalence ratio and premixedness of fuel-air mixture than $CO_2^*$ chemiluminescence.

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A Study on the Limit Heat Release Rate for the Prediction on Fire Characteristics in the Compartment Space (구획공간의 화재성상 예측을 위한 한계 열방출률에 관한 문헌고찰)

  • Huh, Ye-Rim;Lee, Byeong-Heun;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.111-112
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    • 2020
  • In the case of, the ignition of flammable external materials by the radiant flame and the accompanying fire in the upper layer are occurring every year, and in the case of the Flashover prediction formula, the limit is reached through the surface area of the space and the factor. Predicts heat release rate. In this study, the critical heat release rate of each prediction formula was calculated based on the ISO 9705 model.

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Study on Combustion Characteristics of H2/CO Synthetic Gas (H2/CO 합성가스의 연소 특성에 관한 연구)

  • Kim, Tae-Kwon;Park, Jeong;Cho, Han-Chang
    • Journal of Environmental Science International
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    • v.17 no.6
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    • pp.689-698
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    • 2008
  • Numerical study is conducted to predict effects of radiative heat loss and fuel composition in synthetic gas diffusion flame diluted with $CO_2$. The existing reaction models in synthetic gas flames diluted with $CO_2$ are evaluated. Numerical simulations with and without gas radiation, based on an optical thin model, are also performed to concrete impacts on effects of radiative heat loss in flame characteristics. Importantly contributing reaction steps to heat release rate are compared for synthetic gas flames with and without $CO_2$ dilution. It is also addressed that the composition of synthetic gas mixtures and their radiative heat losses through the addition of $CO_2$ modify the reaction pathways of oxidation diluted with $CO_2$.

Analysis of Temprature and Thermal Stress Distribution of a DI Diesel Engine Cylinder Head(PART I) (직접분사식 디젤엔진 실린더헤드의 온도 및 열응력 분포해석(PART I))

  • 이진호;이교승;장경준
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.5
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    • pp.187-196
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    • 1996
  • In this study, 3-dimensional finite element model of a diesel engine cylinder head was made to accomplish heat transfer analysis and also thermal stress and deformation analysis. Heat release analysis and Nusselt-Reynolds correlations were applied to determine the convective boundary conditions which are required for heat transfer analysis to calculate temperature distribution. Thermal stress distribution was also investigated from heat transfer analysis results. Steady state temperature and heat flux were measured by using K-type thermocouples and then compared with numerical results to give a guarantee for the propriety of numerical analyses.

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