• 제목/요약/키워드: Rate of heat release

검색결과 668건 처리시간 0.041초

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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건축용 바닥재의 외부복사열에 의한 화재위험성 비교 연구 (A Study on the Fire Risk Comparison of Building Flooring Materials by External Heat Flux)

  • 박영주;김영탁
    • 한국안전학회지
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    • 제32권5호
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    • pp.20-24
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    • 2017
  • In this study, we have performed the Cone Calorimeter test in accordance with ISO 5660-1 to check the combustion characteristics of building flooring materials. The fire risk of these materials were evaluated by construction code, KFI criteria and standards of flame retardant performance. When samples exposed to external heat flux, all samples consumed a lot of Oxygen for a long time. So heat release from sample burning continued so long. And also all samples produced so much smoke. Even though a few samples were satisfied with only peak heat release rate criteria, all 8 samples were not satisfied with criteria of peak heat release rate and total heat released together. The results of 5 min total heat released were $15.9MJ/m^2{\sim}5.9MJ/m^2$. It menas the results are more than 2~6 times higher than the criteria. The results of 10 min total heat released were $30.1MJ/m^2{\sim}100.8MJ/m^2$. It means the results are more than 3~12 times higher than the criteria. 6 of 8 samples were not satisfied with Dm.corr.(corrected maximum smoke density) criteria. The building flooring materials which we used for this test ignited very fast and the burning continued so long. It means these samples are susceptible to fire.

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 $CO_2$.

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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루버형과 파형핀 열교환기에서 분진이 성능에 미치는 영향에 관한 연구 (A Study of Dust Effect on Performance of Heat Exchangers with Louver and Wavy Fins)

  • 이영림;황순호
    • 한국자동차공학회논문집
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    • 제17권4호
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    • pp.126-132
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    • 2009
  • Automotive heat exchangers use louver fins for their high efficiency. However, the efficiency can significantly drop for constructional vehicles or heavy equipments due to dust deposited on the louver fins with narrow slits. Thus it is necessary to develop new fins that lead to less fouling, so that a better performance can be achieved after exposure to a dusty environment over long period of time. New wavy fins were considered in the study and numerically analysed to compare with louver fins in the areas of air-side pressure drop, heat release rate, and particulate deposition. In addition, an experiment was done on the pressure drop and the particulate deposition. The results showed that the wavy fins would be a better choice for long-term use due to the excellent dust-proof performance in comparison to louver fins, in spite of the initial inferior performance of heat release.

트레이용 난연 전력 케이블의 화재특성에 관한 실험적 연구 (Experimental Study of Fire Characteristics of a Tray Flame Retardant Cable)

  • 김성찬;김정용;방경식
    • 한국안전학회지
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    • 제28권3호
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    • pp.39-43
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    • 2013
  • The present study has been conducted to investigate the fire combustion properties and fire behavior of an IEEE-383 qualified flame retardant cable. The reference reaction rate and reference temperature which are commonly used in pyrolysis model of fire propagation process was obtained by the thermo-gravimetric analysis of the cable component materials. The mass fraction of FR-PVC sheath abruptly decreased near temperature range of $250{\sim}260^{\circ}C$ and its maximum reaction rate was about $2.58{\times}10^{-3}$[1/s]. For the XLPE insulation of the cable, the temperature causing maximum mass fraction change was ranged about $380{\sim}390^{\circ}C$ and it has reached to the maximum reaction rate of $5.10{\times}10^{-3}$[1/s]. The flame retardant cable was burned by a pilot flame meker buner and the burning behavior of the cable was observed during the fire test. Heat release rate of the flame retardant cable was measured by a laboratory scale oxygen consumption calorimeter and the mass loss rate of the cable was calculated by the measured cable mass during the burning test. The representative value of the effective heat of combustion was evaluated by the total released energy integrated by the measured heat release rate and burned mass. This study can contribute to study the electric cable fire and provide the pyrolysis properties for the computational modeling.

퍼니쳐 칼로리미터를 이용한 화재 특성 평가 (Fire Characteristics Evaluation by Using Furniture Calorimeter)

  • 권오상;유용호;김흥열
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.44-47
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    • 2008
  • This paper evaluated the fire characteristics by using furniture calorimeter. Fire property assessment using the furniture calorimeter showed that the heat release rate is maximum 1,600 kW, maximum CO is 0.261%, maximum CO2 is 2.597%, while for the sofa for one person, the maximum heat release rate is approx. 531.5 kW, max. CO is 0.102%, and max. CO2 is 1.011%.

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메탄화재의 이산화탄소 생성법에 의한 화재발열량 측정 (Measurement of Heat Release Rate by Carbon Dioxide Generation Method for Methane Fire)

  • 김성찬
    • 한국화재소방학회논문지
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    • 제34권2호
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    • pp.1-6
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    • 2020
  • 연소상태의 가연물에서 방출되는 에너지는 비정상적인 특성과 폭넓은 크기규모를 가지기 때문에 다른 화재물리량에 비해 측정하기 어려운 문제 중의 하나로 인식된다. 본 연구는 실험실규모의 화재 발열량계에서 이산화탄소생성법과 산소소모법에 의해 계산된 측정 발열량을 비교하여 상대오차를 분석하였다. 메탄 버너화재에 대해 산소소모계수와 CO2 질량유량의 상관관계는 6% 이내에서 우수한 선형성을 보였다. CDG법의 계산에서 CO에 의한 발열량 기여분은 CO2에 의한 기여분에 비해 7% 이내로 크지 않게 나타났다. 준정상상태의 기준 버너 발열량 대비 OC법과 CDG법의 선형성은 1% 이내를 보여 발열량 측정에 있어서 CDG법은 상호 보완할 수 있는 측정수단으로 활용될 수 있다.

영동지역 주요 침엽수종 및 활엽수종 생엽의 연소특성에 관한 연구 (A Study on Combustion of Living Leaves for Various Coniferous Trees and Broadleaf Trees in Youngdong Areas)

  • 이해평;이시영;박영주
    • 한국안전학회지
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    • 제24권4호
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    • pp.96-103
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    • 2009
  • This study was fulfilled to investigate the forest fire risk of forest fuels based on the combustion characteristics of living leaves of coniferous trees and broadleaf trees naturally growing in Youngdong areas of Gangwon Province by using cone calorimeter and smoke density chamber. According to the result, Pinus densiflora and Pinus rigida among coniferous trees released a greater amount of heat release than other kinds. The total smoke release varied depending on the species, whereas Pinus koraiensis showed the largest amount of smoke release. With regard to maximum smoke density, it was much higher in coniferous trees than in broadleaf trees. With regard to smoke temperature, Pinus densiflora showed the lowest compared to other kinds up until 200s from the ignition, but all most trees uniformly maintained constant temperature of about $70^{\circ}C$ after 200s. The concentrations of CO and $CO_2$ release were drastically increased at about 150s and then gradually decreased thereafter. Pinus densiflora showed a bit higher CO release than broadleaf trees, but there was no distinct difference in $CO_2$ release among tress.

조기연료 기화장치의 냉간 시동 및 주행 성능 분석 (Early Fuel Evaporator Effects on Cold Driveability of Automobile)

  • 전흥신
    • 에너지공학
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    • 제11권2호
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    • pp.178-185
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    • 2002
  • 본 연구의 목적은 조기 연료 기화장치가 승용차의 냉간 주행성능에 미치는 영향을 조사하여 평가하는 것이다. 이를 위해 실험은 냉 시동성과 냉간 주행성능으로 나누어 실시하여 연료소비율과 유해 배출 가스량을 측정하고, 실린더내의 연소압력을 근거로 열 발생율, 적산 열 발생량, 질량연소율을 구하였다. 결과는 다음과 같다. 조기연료 기화장치의 장착은 냉 시동 초기부터 난기 완료까지의 연료소비량을 17.7%향상, 냉 시동 초기의 일산화탄소의 배출량은 23%, 탄화수소 배출량은 45% 저감 되고, 또한 냉간 주행시의 엔진의 연소 최고압력, 도시 평균 유효압력의 변동을 4∼6% 개선시키고, 단위 출력당 연료 소비율이 0.2∼2.3% 절감된다. 이것은 조기연료기화장치에 의한 연소실내 최대 열 발생 지연기간 및 주 연소기간이 짧아지기 때문이다.