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The Evolving Temperature Field in a 1 m Methanol Pool Fire. 1m甲醇池火灾的演变温度场
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2021-01-01 DOI: 10.1177/07349041211019636
Jian Chen, Kunhyuk Sung, Zhigang Wang, Wai Cheong Tam, Ki Yong Lee, Anthony Hamins

Thin filament pyrometry is used to measure the time-varying temperature field in a 1 m methanol pool fire. A digital camera with optical filters and zoom lens recorded the emission intensity of an array of 12 μm Silicon-Carbide filaments oriented horizontally at various heights across the steadily burning pool fire. A 50 μm diameter thermocouple measured the temperature at locations corresponding to the filament positions. A correlation was developed between the local probability density functions of the thermocouple time series measurements corrected for radiation and thermal inertia effects and the camera grayscale pixel intensity of the filaments. A regression analysis yields the local mean temperature and its variance. The time series of the temperature field is transformed into average values during consecutive phases of the fire's puffing cycle, providing quantitative insight into the complex and dynamic structure of a turbulent fire.

细丝高温计用于测量1m甲醇池火灾中的时变温度场。一台带滤光器和变焦镜头的数码相机记录了一组12µm碳化硅丝的发射强度,这些丝在稳定燃烧的池火中以不同高度水平定向。直径为50µm的热电偶测量灯丝位置对应位置的温度。针对辐射和热惯性效应校正的热电偶时间序列测量的局部概率密度函数与灯丝的相机灰度像素强度之间建立了相关性。回归分析得出局部平均温度及其方差。在火灾膨胀周期的连续阶段,温度场的时间序列被转换为平均值,从而定量了解湍流火灾的复杂动态结构。
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引用次数: 0
Experimental determination of the evolution of the incident heat flux received by a combustible during a cone calorimeter test: Influence of the flame irradiance 锥形量热计试验中可燃物接收的入射热流演变的实验测定:火焰辐照度的影响
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-12-14 DOI: 10.1177/0734904120970440
Fabien Hermouet, É. Guillaume, T. Rogaume, F. Richard, Mohamad El Houssami
The decomposition kinetic of polymeric materials in a cone calorimeter strongly depends on the irradiance level imposed at the sample’s surface. Indeed, even if the irradiance level is supposed to be kept constant during cone calorimeter test, the amount of heat flux which is emitted by the flame can greatly increase the total heat flux received by the material. Analytical treatment on recently obtained results of an acrylonitrile-butadiene-styrene’s mass loss rate with controlled atmosphere cone calorimeter has shown that the differences observed between well-ventilated and inert environments can be attributed to the impact of the flame. This observation has brought the necessity to determine the impact of the flaming process on the material thermal decomposition. To do so, series of experiments have been devised, based on the insertion of a heat fluxmeter within the matrix of an acrylonitrile butadiene styrene material, during cone calorimeter tests in order to measure the flame heat flux as a function of the decomposition and the combustion processes.
锥形量热计中聚合物材料的分解动力学在很大程度上取决于施加在样品表面的辐照度水平。事实上,即使假设在锥形量热计测试期间辐照度水平保持恒定,火焰发出的热通量也会大大增加材料接收的总热通量。用可控气氛锥形量热计对最近获得的丙烯腈-丁二烯-苯乙烯质量损失率结果进行分析处理表明,在通风良好的环境和惰性环境之间观察到的差异可归因于火焰的影响。这一观察结果使得有必要确定燃烧过程对材料热分解的影响。为此,在锥形量热计测试过程中,基于在丙烯腈-丁二烯-苯乙烯材料基体中插入热通量计,设计了一系列实验,以测量作为分解和燃烧过程函数的火焰热通量。
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引用次数: 5
Book review: A Gallery of Combustion and Fire 书评:燃烧与火的画廊
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-12-10 DOI: 10.1177/0734904120977432
A. Morgan
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引用次数: 0
A chain is no stronger than its weakest link: Weathering resistance of water-based intumescent coatings for steel applications 一条链的强度不亚于其最弱的一环:用于钢铁应用的水性膨胀型涂料的耐候性
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-11-25 DOI: 10.1177/0734904120961064
Lars-Hendrik Daus, B. Schartel, V. Wachtendorf, R. Mangelsdorf, M. Korzen
A systematic approach was used to investigate the weathering-induced degradation of a common water–based intumescent coating. In this study, the coatings are intended for humid indoor applications on steel substrates. The coating contains ammonium polyphosphate, pentaerythritol, melamine, and polyvinyl acetate. By replacing each ingredient with a less water-soluble substance, the most vulnerable substances, polyvinyl acetate and pentaerythritol, were identified. Furthermore, the weathering resistance of the system was improved by exchanging the ingredients. The coatings were stressed by artificial weathering tests and evaluated by fire tests. Thermogravimetry and Fourier-transform infrared spectroscopy were used to study the thermal decomposition. This study lays the foundation for the development of a new generation of water-based intumescent coatings.
采用系统的方法研究了普通水基膨胀型涂料的风化降解。在本研究中,该涂料适用于潮湿的钢基材室内应用。该涂料含有聚磷酸铵、季戊四醇、三聚氰胺和聚乙酸乙烯酯。通过用水溶性较差的物质代替每种成分,确定了最脆弱的物质,聚乙酸乙烯酯和季戊四醇。此外,通过组分的交换,提高了体系的耐候性。涂层通过人工风化试验进行了应力测试,并通过防火试验进行了评估。采用热重法和傅立叶变换红外光谱法研究了热分解过程。本研究为开发新一代水性膨胀涂料奠定了基础。
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引用次数: 8
Anisotropy of expandable graphite to explain its behavior as a flame-retardant 可膨胀石墨的各向异性以解释其作为阻燃剂的行为
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-11-25 DOI: 10.1177/0734904120969639
T. Bensabath, J. Sarazin, S. Bourbigot
Expandable graphite is used as a flame-retardant in polymers. Its expansion on heating leads to a network of graphite worms which acts as a thermal barrier. However, mechanisms of action of worms are not yet well known. An original experimental approach is performed to study the heat dissipation in the network of worms. The network is made by the burning of polypropylene with 10 wt% expandable graphite during cone calorimeter experiment. After the burning, a hot spot is applied on the char. Temperature is monitored at different locations of sample during the combustion and after the application of the hot spot. During cone calorimetry, the char develops homogeneously over the whole sample. The hot spot test evidences the anisotropy of the entangled network of graphite worms. This anisotropy of heat conductivity allows the dissipation of heat in-plane and poorly out of plane, which explains the thermal barrier effect made by entangled worms.
可膨胀石墨在聚合物中用作阻燃剂。它在加热时膨胀,形成一个石墨蠕虫网络,起到热障的作用。然而,蠕虫的作用机制尚不清楚。提出了一种新颖的实验方法来研究蠕虫网络的散热问题。该网络是在锥形量热仪实验中用10%可膨胀石墨燃烧聚丙烯制成的。烧完后,在炭上加一个热点。在燃烧过程中和应用热点后,监测样品不同位置的温度。在锥量热法中,炭在整个样品上均匀地发展。热点实验证明了石墨蠕虫纠缠网络的各向异性。这种热传导性的各向异性使得热在平面内散失,而在平面外散失很差,这就解释了缠虫产生的热障效应。
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引用次数: 2
Flammability testing of wool/cellulosic and wool/synthetic fiber blends: Vertical flame spread and heat release results 羊毛/纤维素和羊毛/合成纤维混合物的易燃性测试:垂直火焰蔓延和热释放结果
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-11-01 DOI: 10.1177/0734904120954013
A. Morgan, M. Galaska
Wool is a natural fiber with lower heat release/flammability than some synthetic fabrics, but it has not been well studied for its heat release when other fibers such as cotton, linen, and nylon are present in the woven fabric. In this article, the heat release and vertical flame spread of six commercially available natural color fabrics is reported. This includes 100% wool, 80% wool/20% nylon, 70% wool/30% linen, 45% wool/55% cotton, and 40% wool/38% cotton/12% nylon/10% metallic thread fabric. Heat release was measured through cone calorimetry (ASTM E1354) as a function of the sample mounting method, through microscale combustion calorimetry (ASTM D7309), and flame spread was measured by ASTM D6413. The type of insulated backing used greatly affected the cone calorimeter results, and fabric types did show some effects in vertical flame spread and microscale combustion calorimeter testing.
羊毛是一种天然纤维,其热释放/可燃性比一些合成织物低,但当织物中存在棉、亚麻和尼龙等其他纤维时,羊毛的热释放尚未得到充分研究。本文报道了六种市售天然色织物的热释放和垂直火焰传播。这包括100%羊毛、80%羊毛/20%尼龙、70%羊毛/30%亚麻、45%羊毛/55%棉和40%羊毛/38%棉/12%尼龙/10%金属线织物。通过锥形量热法(ASTM E1354)作为样品安装方法的函数,通过微尺度燃烧量热仪(ASTM D7309)测量热释放,并通过ASTM D6413测量火焰蔓延。使用的隔热背衬类型对锥形量热计的结果有很大影响,织物类型在垂直火焰蔓延和微型燃烧量热计测试中确实显示出一些影响。
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引用次数: 4
Facile preparation of uniform polydopamine particles and its application as an environmentally friendly flame retardant for biodegradable polylactic acid 均匀聚多巴胺颗粒的简易制备及其作为可生物降解聚乳酸环保阻燃剂的应用
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-11-01 DOI: 10.1177/0734904120932479
Benjamin Tawiah, Bin Yu, A. Yuen, B. Fei
The demand for environmentally benign flame retardants for biodegradable polymers has become particularly necessary due to their inherently “green” nature. This work reports intrinsically non-toxic polydopamine (PDA) particles as an efficient and environmentally friendly flame retardant for polylactic acid (PLA). 5 wt% PDA loading resulted in a 22% reduction in the peak heat release rate, 34.7% increase in the fire performance index, and lower CO2 production compared to neat PLA. A limiting oxygen index (LOI) value of 27.5% and a V-2 rating was achieved in the UL-94 vertical burning test. Highly aggregated amorphous particulate char was formed with the increasing content of PDA, and a significant reduction in evolved pyrolysis gaseous products was achieved for the PLA/PDA composites as compared with control PLA. This work provides important insight into the potential commercial application of PDA alone as an efficiently green, environmentally benign flame retardant for bioplastic PLA.
由于可生物降解聚合物本身的“绿色”性质,对环境友好型阻燃剂的需求变得特别必要。本工作报道了本质无毒的聚多巴胺(PDA)颗粒作为一种高效环保的聚乳酸(PLA)阻燃剂。与纯PLA相比,5 wt%的PDA负载导致峰值热释放率降低22%,防火性能指数提高34.7%,二氧化碳排放量降低。UL-94垂直燃烧试验的极限氧指数(LOI)为27.5%,达到V-2等级。随着PDA含量的增加,PLA/PDA复合材料形成了高度聚集的非晶态颗粒炭,与对照PLA相比,PLA/PDA复合材料的热解气态产物显著减少。这项工作为PDA单独作为生物塑料PLA的高效绿色、环保阻燃剂的潜在商业应用提供了重要的见解。
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引用次数: 6
Theoretical analysis of the liquid thermal structure in a pool fire 水池火灾中液体热结构的理论分析
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-10-20 DOI: 10.1177/0734904120962376
T. Beji
This article presents a theoretical work on liquid heat-up in the case of a pool fire. It is assumed that the convective currents occurring within the upper layer of the liquid are induced by Rayleigh–Bénard instabilities that are caused by in-depth radiation. The upper layer depth has been estimated based on the analytical solution of a one-dimensional Fourier’s equation for the temperature with a source term for in-depth radiation. The model has been assessed against experimental data for a 9-cm-diameter methanol steady-state pool fire and three different liquid depths (18, 12 and 6 mm). The general trend, that is, increase in the upper layer depth as the bottom boundary temperature increases, is well captured. In order to ensure that the well-mixed upper layer is at a temperature near the boiling point (as suggested by the experimental data), an improvement is proposed based on a radiative heat balance integral method. In addition to the above, a novel methodology is developed for the calculation of the ‘effective’ thermal conductivity as a means to circumvent detailed calculations of heat transfer within the liquid.
本文介绍了池火情况下液体加热的理论工作。假定在液体上层内发生的对流流是由深层辐射引起的瑞利-巴萨姆德不稳定性引起的。基于一维傅里叶温度方程的解析解估计了上层深度,其中有深度辐射的源项。该模型已根据9厘米直径的甲醇稳态池火和三种不同的液体深度(18,12和6mm)的实验数据进行了评估。总的趋势,即随着底边界温度的升高,上层深度增加,被很好地捕捉到了。为了保证混合良好的上层在沸点附近的温度(如实验数据所示),提出了基于辐射热平衡积分法的改进方法。除此之外,还开发了一种计算“有效”导热系数的新方法,以绕过液体内传热的详细计算。
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引用次数: 7
Development and validation of simple-shield thermocouple in fire environments 火灾环境中简易屏蔽热电偶的研制与验证
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-10-20 DOI: 10.1177/0734904120963812
Ho-Sik Han, Cheol-Hong Hwang
A novel simple-shield thermocouple that is capable of radiation correction in fire environments and that has a simpler structure and greater convenience than conventional aspirated thermocouples was proposed. The measurement errors of bare-bead, double-shield aspirated, and simple-shield thermocouples were then compared in a simulated fire environment. In addition, a fire experiment using wood cribs was performed in order to verify the measurement performance of the proposed simple-shield thermocouple in a real fire environment using a one-third-scale ISO 9705 room. The simple-shield thermocouple produced fairly accurate temperatures that fell within 5% of the actual gas temperature in the simulated fire environment. In addition, variations in the surface emissivity and the installation angle of the simple-shield thermocouple in the real fire environment further reduced the measurement error. With a radiant heat flux of 20 kW/m2, it was confirmed that the bare-bead thermocouple had a relative measurement error of up to 80% compared to the aspirated thermocouple, while the proposed simple-shield thermocouple was capable of measuring the temperature within a relative error of around 15% compared to the aspirated thermocouple.
提出了一种新型的简单屏蔽热电偶,该热电偶能够在火灾环境中进行辐射校正,并且比传统的吸气式热电偶具有更简单的结构和更大的便利性。然后在模拟火灾环境中比较了裸珠、双屏蔽吸气和简单屏蔽热电偶的测量误差。此外,还使用木垛进行了火灾实验,以验证所提出的简单屏蔽热电偶在使用三分之一比例ISO 9705房间的真实火灾环境中的测量性能。简单的屏蔽热电偶产生了相当准确的温度,在模拟火灾环境中,温度降至实际气体温度的5%以内。此外,在实际火灾环境中,简单屏蔽热电偶的表面发射率和安装角度的变化进一步降低了测量误差。辐射热通量为20 kW/m2,证实裸珠热电偶与吸气式热电偶相比具有高达80%的相对测量误差,而所提出的简单屏蔽热电偶与吸气热电偶相比能够在约15%的相对误差内测量温度。
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引用次数: 0
Development and calibration of reduced-size plate thermometer for measuring incident heat flux 用于测量入射热通量的小尺寸板温度计的研制和校准
IF 1.9 4区 工程技术 Q2 Engineering Pub Date : 2020-10-04 DOI: 10.1177/0734904120958602
Hong-Seok Yun, Ho-Sik Han, Cheol-Hong Hwang
This study proposes a new reduced-size plate thermometer with a modified shape and improved insulation performance in order to resolve problems commonly found when using conventional plate thermometers to measure incident heat flux in fire environments, for example, a low spatial resolution caused by the large plate area and a non-uniform temperature distribution on the plate. The main results of this study showed that the new plate thermometer exhibits high spatial temperature uniformity, and that the plate thermometer can be reduced in size to 30 mm. Moreover, it was found that the relative error of the incident heat flux of the plate thermometer was substantially reduced compared to that of a heat flux meter using a conduction correction factor expressed as a third-order polynomial function of heat flux, rather than using an average empirical constant calculated from measurement over a wide range of heat fluxes. Finally, it was confirmed that the incident heat flux measured by the new reduced-size plate thermometer in a heptane pool fire was in good agreement with the heat flux meter measurements during the rapid-fire growth, fully developed and decay phases of a fire.
为了解决传统平板温度计在火灾环境中测量入射热流时,由于平板面积大、平板温度分布不均匀导致空间分辨率低的问题,本研究提出了一种外形改进、保温性能提高的小尺寸平板温度计。本研究的主要结果表明,新型平板温度计具有较高的空间温度均匀性,并且可以将平板温度计的尺寸缩小到30 mm。此外,研究发现,与热流计相比,使用以热流计的三阶多项式函数表示的传导校正因子,而不是使用在广泛的热流计范围内测量计算的平均经验常数,大大减少了平板温度计入射热流的相对误差。最后,验证了新型缩小板测温仪在庚烷池火灾中测量的入射热流密度与热流密度计在火灾快速生长、充分发育和衰减阶段的测量结果吻合较好。
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引用次数: 2
期刊
Journal of Fire Sciences
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