• Title, Summary, Keyword: heat release rate

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Fire Characteristics of Composites for Interior Panels Using Cone calorimeter (콘칼로리미터를 이용한 내장판용 복합재료의 화재특성)

  • 이철규;정우성;이덕희
    • Journal of the Korean Society for Railway
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    • v.7 no.1
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    • pp.55-59
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    • 2004
  • Composite materials were used widely due to merit of light weight, low maintenance cost and easy installation. But it is the cause of enormous casualties to men and properties because of weak about the fire. Particularly, it is more serious in case of subway train installed composite materials. For this reason, experimental comparison has been done fur measuring heat release rate(H.R.R) and smoke production rate(S.P.R) of interior panels of electric motor car using cone calorimeter. A high radiative heat flux of 50kW/㎡ was used to bum out all materials and to simulate the condition of fully developed fire case in the tests. It was observed that Heat Release Rate and Smoke Production Rate curves were dependent on the kinds of the interior materials. From the heat release rate curves, the sustained ignition time, peak heat release rate and total heat release rate were deduced, These data are useful in classifying the materials by calculating two parameters describing the possibility to flashover.

Ignition and Heat Release Rate of Wood-based Materials in Cone Calorimeter Tests

  • Park, Joo-Saeng;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.2
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    • pp.1-8
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    • 2008
  • This study was performed to evaluate the burning characteristics of wood-based materials and the effect of surface treatment of fire retardant using cone calorimeter. Four types of wood-based materials, such as Plywood, Oriented Strand Board (OSB), Particle Board (PB) and Medium Density Fiberboard (MDF), were tested at a constant heat flux of $50kW/m^2$ to investigate the time to ignition, mass loss rate, heat release rate, effective heat of combustion, etc. In addition, each type of wood-based material was tested at the same heat flux after fire retardant treatment on the surface to evaluate the effect of this treatment on the burning characteristics. The surface treatment of fire retardant, by the amount of $110g/m^2$, delayed the time to ignition almost twice. However, it was indicated that heat release rate, mass loss rate, and effective heat of combustion were not significantly affected by fire retardants treatment for all types of wood-based materials.

A Numerical Study on the Effect of Volume Change in a Closed Compartment on Maximum Heat Release Rate (밀폐된 구획실의 체적변화가 최대 열발생률에 미치는 영향에 관한 수치해석 연구)

  • Yun, Hong-Seok;Nam, Dong-Gun;Hwang, Cheol-Hong
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.19-27
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    • 2017
  • The effects of changes in area and location of fire source, fire growth rate, and volume of compartment on the major fire characteristics, including heat release rate, in closed compartment fires were examined. To this end, a fire simulation using Fire Dynamics Simulator (FDS) was performed for ISO 9705 room with a closed opening. As main result, it was found that the changes in the area and location of fire source did not significantly affect the thermal and chemical characteristics inside the compartment, such as maximum heat release rate, total heat release, maximum temperature at upper layeras well as species concentrations. However, increasinthe fire growth rate and volume of compartment resulted in increase of the maximum heat release rate and total heat release, decrease in the limiting oxygen concentration and increase in the maximum CO concentration. Finally, a methodology for the application of fire growth curves to closed compartment fires was proposed by deriving the correlation of the maximum heat release rate expressed as a function of the fire growth rate and the volume ratio of compartment based on the ISO 9705 room.

A Study on the Calculation of Heat Release Rate to Compensate the Error due to Single Zone Assumption in Diesel Engines (단일 영역 모델 열발생율 계산 방법의 개선에 관한 연구)

  • Kim Ki-Doo;Yoon Wook-Hyeon;Ha Ji-Soo;Ryu Seung-Hyup
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.7
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    • pp.1063-1071
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    • 2004
  • Accurate heat release analysis of cylinder pressure data is important for evaluating performance in the development of diesel engine However, traditional single zone first law heat release model(SZM) has significant limitations due to the simplified assumption of uniform charge and neglecting local temperature inside cylinder during combustion process. In this study. heat release rate based on single zone heat release model has been evaluated by comparison with computational analysis results using Fire code which is based on multi-dimensional model(MDM). To overcome limitations due to simplicity of single zone assumption. especially the influence of specific heat ratio on gross heat release has been esteemed and newly suggested were the equation $\gamma$= $\gamma$(${T/T}_{max}$) which describes the variations of gases thermodynamic properties with mean temperature and maximum mean temperature inside cylinder Single zone heat release model applied with this equation is shown to give very good results over whole range of operating conditions when compared with computational analysis results based on multi-dimensional model.

Experimental Study on the Measurement of Fire Behavior and Heat Release Rate in Building Compartment Space - Focus on Full Scale Fire Test of the Bed Mattress - (건축물 구획공간에 따른 화재성상 및 열방출율 측정에 관한 실험적 연구 - 실물규모 침대 매트리스 화재시험 중심으로 -)

  • Seo, Bo-Youl;Jang, Woo-Bin;Park, Kye-Won;Hong, Won-Hwa
    • Fire Science and Engineering
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    • v.32 no.6
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    • pp.28-33
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    • 2018
  • To measure the full scale fire test and heat release rate of bed mattresses according to the building compartment space, a fire test was performed using the Standard test method to determine the heat release rate of mattresses and mattress sets (KS F ISO 12949: 2011). Both test locations showed similar fire growth until approximately 3 minutes after burner ignition. After 3 minutes, the heat release rate in the test room was higher than the open calorimeter. For bed mattresses (SS), the maximum heat release rate in the open calorimeter was 735 kW and the maximum heat release rate in the test room was 992 kW. For bed mattresses (Q), the heat release rate in the test room increased more rapidly than the open calorimeter. The maximum heat release rate in the open calorimeter was 1,087 kW (346 s) and the maximum heat release rate in the test room was 2,127 kW (287 s). The difference between the maximum heat release rate and the measurement time according to the test location was confirmed.

A study on the heat release rate pattern variation according to the change of operating conditions in pre-combution chamber type diesel engine (예연소실식 디젤기관의 운전조건변화에 따른 열발생률 형태변동에 관한 고찰)

  • 이진우;최재성;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.11 no.3
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    • pp.31-44
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    • 1987
  • Nowadays, the problems of energy and environmental pollution become serious day by day and the diesel engine, which has been proved to be superior to gasoline engine with respect to fuel consumption and ecological problems of exhaust gas, has been adopted widely for various purposes from the marine diesel engine and the dynamo engine to all kinds of engine on land. Therefore, extensive parametric studies on combustion of diesel engine should be done for its desing and improvement. To predict the behavior of diesel engien according to variable operating conditions by means of cycle simulation, the reasonable pattern of heat release rate has to be asumed. But it is necessary to know the actual variation of heat release rate in order to assume the reasonable pattern of heat release rate according to the actual operating conditions. In this paper, on a high speed small bore diesel engine with pre-combustion chamber, experimental investigations were carried out to determine the relationship between the heat release pattern and parameters such as engine load and speed. And also, the theoretical investigations about the performance variations of the above diesel engine according to the predicted pattern of heat release rate variation were performed. From the above observations, it may be said that the Fanboro indicator, which was used to get the cylinder pressure, can be used to estimate a reasonable pattern of heat release rate and it is confirmed that the pattern of heat release rate for the pre-combustion type engine is different from that of the direct injection type engine.

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Prediction of Spatial Heat Release Rate of Combustion Chamber by Radicals-PLIF (라디칼 PLIF계측을 이용한 연소실의 공간적 열발생율 예측)

  • Choi, G.M.
    • Journal of ILASS-Korea
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    • v.8 no.4
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    • pp.9-16
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    • 2003
  • The Purpose of this study is to investigate the relationships between the local heat release rate and CH concentration have been investigated by numerical simulations of methane-air premixed flames. And simultaneous CH and OH PLIF(Planar Laser Induced Fluorescence) measurement has been also conducted for lean premixed flame as well as for laminar flames. Numerical simulations are conducted for laminar premixed flames and turbulent ones by using PREMIX in CHEMKIN and two dimensional DNS code with GRI mechanism version 2.11, respectively. In the case of laminar premixed flame, the distance between the peak of heat release rate and that of CH concentration is under $91{\mu}m$ for all equivalence ratio calculated in present work. Even for the premixed flame in high intensity turbulence, the distribution of the heat release rate coincides with that of CH mole fraction. For CH PLIF measurements in the laminar premixed flame burner, CH fluorescence intensity as a function of equivalence ratio shows a similar trend with CH mole fraction computed by GRI mechanism. Simultaneous CH and OH PLIF measurement gave us useful information of instantaneous reaction zone. In addition, CH fluorescence can be measured even for lean conditions where CH mole fraction significantly decreases compared with that of stoichiometric condition. It was found that CH PLIF measurements can be applicable to the estimation of the spatial fluctuations of heat release rate in the engine combustion.

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Calculation of Uncertainty in Measuring Heat Release Rate in Room Corner Test (룸코너 시험기의 발열량 측정에 대한 불확도 산정)

  • Noh, Kwang-Chul;Kim, Chi-Hoon;Lee, Seung-Chul;Lee, Duck-Hee
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.16-22
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    • 2012
  • In fire test, accurate heat release rate measurements provide important information to define the fire safety characteristics of products. The calculation of heat release rate depends on the errors of measuring parameters in experimental set-up. In this study, the uncertainty factors of heat release rate in the room corner test facility, which is installed at Korea Railroad Research Institute, were analyzed. Through the fire testings for the KTX interior materials, the uncertainties of heat release rate were calculated. Results showed that uncertainty was high in the initial stage of fire test and gradually decreased with the growth of fire. The oxygen concentration was a major factor contributing to the combined relative standard uncertainty.

Analysis of Heat Quantity in CNG Direct Injection Bomb(1) : Homogeneous Charge (CNG 직접분사식 연소기에서의 열량해석(1) :균질급기)

  • 최승환;전충환;장영준
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.2
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    • pp.17-23
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    • 2004
  • A cylindrical constant volume combustion bomb is used to investigate the combustion characteristics and to analyze the heat quantity of homogeneous charge methane-air mixture under various initial pressures, excess air ratios and ignition times. As the overall pressure increase, the values of maximum combustion pressure, maximum heat release rate and cumulative heat release have been increased. But it is not very meaningful to compare with some values such as maximum combustion pressure, maximum heat release rate and cumulative heat release for different overall pressure due to the different heat energy of supplied fuel. So the each value is needed to be compared with normalized value, which is divided by the entered fuel energy. To analyze the heat quantity, some definitions including the CHR ratio, the UHC ratio and the HL ratio are needed and are calculated. As the overall pressure increase, the CHR ratios and the UHC ratios have been decreased, while the HL ratios have been increased. The CHR ratio of 300 ms has the higher value than that of 10000ms, and the HL ratios of 300 ms have a lower value.

An Analysis of False Alarm Threshold Value by Heat Detector Using Heat Release Rate (열방출률을 이용한 열감지기의 오동작 경계값 분석)

  • 홍성호;김두현
    • Fire Science and Engineering
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    • v.17 no.3
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    • pp.26-30
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    • 2003
  • This paper presents a study on the analysis for false alarm of heat detector using HRR(Heat Release Rate). And it is represented to threshold value and domain of false alarm. The HRR threshold value of false alarm is calculated to use parameters obtained by small scale fire-experiment. The experiment is conducted to measure detector activation time and flame spread of wood cribs fire, etc. The results show that HRR threshold value of Fixed type detector is 20.24 kW and rate of rise type detector is 13.59 kW, respectively.