• Title/Summary/Keyword: Heat Release

검색결과 1,073건 처리시간 0.029초

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

  • 박승민;김운형;윤명오
    • 한국화재소방학회논문지
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    • 제16권2호
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    • pp.75-80
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    • 2002
  • 지하공동구에 사용되는 케이블의 연소특성 중 열방출량과 연기 유독성 실험을 수행하였다. 열 방출량 실험은 22.9 kv 전력용 케이블을 대상으로 ISO 9705 규격의 공간에서 수행하였으며 유독성가스의 정량적 위험성 평가를 위하여 NES 713(British-Naval Engineering Standard)을 적용하였다. 실험 결과 측정높이 1.2 m를 기준으로 계산한 케이블의 열 방출 율은 60 kW로 예측되었다. 한편, 케이블의 연기유독성을 위한 NES 실험 결과, 인체에 치명적인 CO의 경우 30분 노출시 사망에 이를 수 있고 의식불명상태가 될 수 있는 수준으로 판정되었다

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

  • 서성현
    • 한국연소학회지
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    • 제17권1호
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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.

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

  • 배승용;성건혁;유홍선;홍기배;김동현
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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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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정적 연소실내의 메탄-공기 혼합기의 연소 특성에 관한 연구 (A Study on the Combustion Characteristics of Methane-air Mixture in Constant Volume Combustion Chamber)

  • 이창식;김동수;오군섭
    • 한국자동차공학회논문집
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    • 제4권4호
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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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에틸렌-프로필렌 디엔 단량체/폴리프로필렌/클레이 나노복합체의 연소성 (Combustive Properties of Ethylene-Propylene Die Monomer/Polypropylene/Clay Nanocomposites)

  • 정영진
    • 한국화재소방학회논문지
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    • 제25권6호
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    • pp.190-195
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    • 2011
  • 에틸렌-프로필렌 디엔 단량체/폴리프로필렌에 바탕을 둔 에틸렌-프로필렌 디엔 단량체, 폴리프로필렌, 산화아연, 스테아르산, 그리고 클레이의 효과에 대하여 연소성을 조사하였다. 에틸렌-프로필렌 디엔 단량체/폴리프로필렌/클레이 나노복합체는 성형 후 콘칼로리미터(ISO 5660-1)를 이용하여 연소시험을 하였다. 그 결과 나노복합체는 에틸렌-프로필렌 디엔 단량체/폴리프로필렌 단독 조성에 비하여 최대열방출률을 감소시켰다. 이에 반하여 고무 연화제로 사용된 스테아르산은 자체의 연소성에 의하여 평균열방출률을 증가시켰다.

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

  • 채학병;민정기;이상권;정국삼;원정훈
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2013년도 추계학술대회 초록집
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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
    • 한국연소학회지
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    • 제9권3호
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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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구획공간의 화재성상 예측을 위한 한계 열방출률에 관한 문헌고찰 (A Study on the Limit Heat Release Rate for the Prediction on Fire Characteristics in the Compartment Space)

  • 허예림;이병흔;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 가을 학술논문 발표대회
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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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H2/CO 합성가스의 연소 특성에 관한 연구 (Study on Combustion Characteristics of H2/CO Synthetic Gas)

  • 김태권;박정;조한창
    • 한국환경과학회지
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    • 제17권6호
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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 $CO_2$.

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

  • 이진호;이교승;장경준
    • 한국자동차공학회논문집
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    • 제4권5호
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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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