Fire Safety Journal最新文献_第8页

An experimental and numerical study of fire and plume characteristics of pool fires fueled by diesel-canola oil mixture 柴油-菜籽油混合燃料池火及羽流特性的实验与数值研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-15 DOI: 10.1016/j.firesaf.2025.104560

Navya Muniraj , Weixuan Gong , Muthu Kumaran Selvaraj , William (Ruddy) Mell , Albert Simeoni

This study focuses on validating the fire and plume characteristics predicted by a physics-based fire behavior model, Fire Dynamics Simulator (FDS), widely used for simulating prescribed burns/wildfires. Systematic lab-scale experiments using medium-scale, sooty, buoyancy-controlled pool fires fueled by diesel-canola oil mixture were conducted with different pool fire configurations to mimic the spot and line ignition techniques used in prescribed burns. A suite of measurements, including the fuel mass loss rate, visible flame height, point measurements of temperature, velocity, and radiative and total heat fluxes were recorded. The measured mass loss rate was prescribed in the simulations to avoid the requirement of modeling the complex pyrolysis process. A mixing-controlled combustion model with a prescribed soot yield and a turbulence model suitable for simulating buoyant plumes were used. A sensitivity analysis was conducted to investigate the effects of different radiation models and model parameters on the predicted fire and plume characteristics. Overall, FDS provides good predictions for the flame height and plume temperature but tends to overpredict the plume velocity and underpredict the heat fluxes. The choice of radiation models significantly influences the prediction of plume characteristics and heat fluxes for different configurations. This study provides valuable experimental data on several critical parameters for validating and verifying the reliability of numerical models.

本研究的重点是验证基于物理的火灾行为模型——火灾动力学模拟器（FDS）预测的火灾和羽流特征，FDS广泛用于模拟规定的烧伤/野火。系统的实验室规模实验使用了中等规模、煤烟、浮力控制的以柴油-菜籽油混合物为燃料的池火，采用不同的池火配置来模拟规定烧伤中使用的点和线点火技术。记录了一系列测量结果，包括燃料质量损失率、可见火焰高度、温度、速度、辐射和总热通量的点测量。为了避免模拟复杂的热解过程，在模拟中规定了测量的失重速率。采用了规定产烟量的混合控制燃烧模型和适合模拟浮力羽流的湍流模型。通过敏感性分析，探讨了不同辐射模式和模式参数对预测的火灾和烟羽特征的影响。总体而言，FDS对火焰高度和羽流温度提供了较好的预测，但往往高估了羽流速度，低估了热通量。辐射模式的选择对不同配置下羽流特征和热通量的预测有显著影响。该研究为验证和验证数值模型的可靠性提供了几个关键参数的有价值的实验数据。

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引用次数: 0

A numerical study of transport phenomena and radiation transfer in compartment and façade fires 隔室和隔室火灾中输运现象和辐射传递的数值研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-13 DOI: 10.1016/j.firesaf.2025.104556

Xiaoyi Lu , Ning Ren , Gang Xiong , Alex Krisman , Agarwal Gaurav , Hideki Yoshioka , Yuhei Nishio , Takafumi Noguchi , Yi Wang

This study models the JIS A 1310 fire test configuration of a cubic fire compartment with an attached non-combustible façade wall using the large-eddy simulation code FireFOAM. The focus is to understand heat and mass transfer processes in fully developed compartment fires, with a particular emphasis on radiative heat transfer to the façade. Engineering radiation modeling is typically based either on a prescribed radiant fraction or on a prescribed soot or smoke yield. Our numerical results, validated against experimental measurements of flame morphology, temperature distribution, and heat flux profiles, show that the commonly used radiant fraction model provides satisfactory predictions for fire window ejection but significantly underestimates radiative heat flux onto the façade from the ejected fire. By neglecting absorption and assuming that all emission is co-located with the flame sheet, the radiant fraction model fails to account for radiation emission from the non-flaming portion of the fire plume, which experimental results reveal to be hot and sooty and thus likely a significant source of radiation emission. Despite modeling challenges due to oversimplified soot chemistry processes as well as the need of calibrations, the soot yield-based model that captures radiation emission from both the flaming and non-flaming portions of the fire plumes, achieved improved agreement with the experimental heat flux data across a range of fire sizes.

本研究采用大涡模拟代码FireFOAM，模拟JIS A 1310中附不燃侧墙的立方体防火室的防火试验配置。重点是了解充分发展的隔间火灾的传热和传质过程，特别强调辐射传热到表面。工程辐射建模通常基于规定的辐射分数或规定的烟尘或烟雾产量。我们的数值结果，与火焰形态、温度分布和热流分布的实验测量相验证，表明常用的辐射分数模型对火窗喷射提供了令人满意的预测，但明显低估了从喷出的火到表面的辐射热通量。由于忽略吸收并假设所有发射都与火焰片位于同一位置，辐射分数模型无法考虑来自火焰羽流非燃烧部分的辐射发射，实验结果显示该部分是热的和煤烟的，因此可能是一个重要的辐射发射源。尽管由于过于简化的烟尘化学过程以及校准的需要，建模存在挑战，但基于烟尘产量的模型捕获了火焰羽流燃烧和非燃烧部分的辐射发射，在一系列火灾规模的实验热通量数据中取得了更好的一致性。

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引用次数: 0

CFD modeling of radiation emission/absorption and fuel evaporation in methanol pool fires 甲醇池火灾中辐射发射/吸收和燃料蒸发的CFD建模

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-11 DOI: 10.1016/j.firesaf.2025.104557

Ning Ren, Xiaoyi Lu, Yi Wang

Radiation is the dominant mode of heat transfer in large-scale fires and plays a crucial role in driving fire growth. The interaction of radiation with turbulence and chemistry complicates first principles methods in fire modeling. Simple models like the constant radiant fraction model are often used. This model neglect radiation absorption and is not suitable in large-scale fires where the optical path length is long, such as in liquid fuel spill fires and compartment/façade fires. We use FireFOAM simulations to evaluate four alternatives to the constant radiant fraction model in 0.3- and 1.0-m diameter methanol pool fires: the gray-mean absorption emission model, two weighted sum of gray gases (WSGG) models (WSGG-gray and WSGG-banded), and the full spectrum

k

-distribution (FSK) model. Unlike previous studies that fixed the fuel gasification rate at a virtual pool surface, our work uses a liquid fuel model to resolve thermal feedback from the flame and liquid fuel gasification, strictly testing the radiation models by enforcing combustion and pyrolysis feedback. The FSK and WSGG models significantly improve HRR predictions for larger pool fires compared to the constant radiant fraction model, while the gray-mean model overpredicts fire size in both cases.

在大规模火灾中，辐射是主要的换热方式，对火灾的发展起着至关重要的作用。辐射与湍流和化学的相互作用使火灾模拟中的第一性原理方法变得复杂。通常使用诸如恒定辐射分数模型之类的简单模型。该模型忽略了辐射吸收，不适用于光程长度较长的大规模火灾，如液体燃料泄漏火灾和隔层/隔层火灾。我们使用FireFOAM模拟来评估0.3 m和1.0 m直径甲醇池火灾中恒定辐射分数模型的四种替代方案：灰色平均吸收发射模型，两个灰色气体加权和（WSGG）模型（WSGG-灰色和WSGG-带状）和全谱k分布（FSK）模型。不同于以往在虚拟池表面固定燃料气化速率的研究，我们的工作使用液体燃料模型来解决火焰和液体燃料气化的热反馈，通过强制燃烧和热解反馈严格测试辐射模型。与恒定辐射分数模型相比，FSK和WSGG模型显著提高了对大型水池火灾的HRR预测，而灰色平均模型在这两种情况下都高估了火灾规模。

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引用次数: 0

Temperature measurements in sooty buoyant turbulent non-premixed flames under different oxygen concentrations 不同氧浓度下煤烟浮力湍流非预混火焰的温度测量

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-09 DOI: 10.1016/j.firesaf.2025.104555

Gang Xiong , Xingyu Ren , Dong Zeng , Robert Barlow , Yi Wang

Recently, significant efforts at FM have been devoted to creating a comprehensive dataset for 15 kW sooty buoyant turbulent non-premixed flames under different oxygen concentrations (OCs) to support fire model development and validation. The dataset includes global measurements of combustion efficiency and radiant fraction, as well as local measurements of flow velocity, soot volume fraction, and radiation intensity. This study addresses challenges in measuring transient temperatures in these sooty flames using thermocouples. A new method using a single thermocouple with 25 μm wire diameter and a pre-calibrated effective bead size was developed and validated against the dual-thermocouple method. Temperature measurements were completed for the 15 kW sooty flames under 20.9 %, 16.8 %, and 15.2 % OCs. Temperature statistics, including mean, root-mean-square of fluctuations, and probability density functions, were obtained in a two-dimensional plane across the flame centerline. This temperature data complements and extends the existing dataset for the 15 kW sooty buoyant turbulent non-premixed flames, aiding in determining mass entrainment and the convective energy flow rates, and providing deeper insights into the fire dynamics and modeling. This enhanced dataset is a valuable resource for the development and validation of models on soot formation, thermal radiation, and flame extinction in fire simulations.

最近，FM致力于在不同氧浓度（OCs）下创建15 kW煤烟浮力湍流非预混火焰的综合数据集，以支持火灾模型的开发和验证。该数据集包括燃烧效率和辐射分数的全局测量，以及流速、烟尘体积分数和辐射强度的局部测量。本研究解决了使用热电偶测量这些煤烟火焰瞬态温度的挑战。提出了一种采用线径为25 μm的单个热电偶和预先校准的有效磁珠尺寸的新方法，并与双热电偶方法进行了验证。在20.9%、16.8%和15.2% oc下完成了15 kW烟炱火焰的温度测量。在火焰中心线的二维平面上获得了温度统计，包括平均值、波动均方根和概率密度函数。该温度数据补充并扩展了现有的15千瓦煤烟浮力湍流非预混火焰数据集，有助于确定质量卷带和对流能量流率，并为火灾动力学和建模提供更深入的见解。这个增强的数据集是开发和验证火灾模拟中烟尘形成、热辐射和火焰熄灭模型的宝贵资源。

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引用次数: 0

Impact of grassland fire dynamics on particulate emission factors 草地火灾动态对颗粒物排放因子的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-09 DOI: 10.1016/j.firesaf.2025.104554

Alexander J. Josephson , Johanna Aurell , Susan A. Cohen , Troy Walton , Rodman R. Linn , Brian K. Gullett

Understanding particulate emission factors in grassland fires is critical for improving air quality assessments and refining emissions inventories. This study explores the dynamic and heterogeneous nature of fire processes and their influence on particulate emissions. Traditional emission factor inventories often rely on static values, overlooking the spatially and temporally variable dynamics of fire behavior. Through field experiments conducted at Konza Prairie Biological Station measuring emissions with uncrewed aerial vehicles, and computational modeling using HIGRAD/FIRETEC, this research highlights the dependency of emission production on localized fire dynamics, including ignition patterns, fuel properties, and atmospheric conditions. The results demonstrate a need for fire dynamic considerations to accurately capture emissions variability.

了解草原火灾中的颗粒排放因子对于改善空气质量评估和完善排放清单至关重要。本研究探讨了火灾过程的动态性和异质性及其对颗粒物排放的影响。传统的排放因子清单通常依赖于静态值，忽略了火灾行为的空间和时间变化动态。通过在Konza草原生物站进行的现场实验，使用无人驾驶飞行器测量排放，并使用HIGRAD/FIRETEC进行计算建模，本研究强调了排放产生对局部火灾动力学的依赖性，包括点火模式、燃料特性和大气条件。结果表明，需要考虑火灾动力学因素，以准确捕获排放变异性。

引用次数: 0

Impact of smoke control on caregivers' perception and behavioral responses during assisted evacuation at small-scale older people's welfare facilities: A non-interactive VR experiment with free navigation 小规模老年人福利设施辅助疏散过程中烟雾控制对看护者感知和行为反应的影响：自由导航非交互式VR实验

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-08 DOI: 10.1016/j.firesaf.2025.104551

Yoshikazu Minegishi

This study explores the smoke control design that enables caregivers to conduct assisted evacuations of older residents in small-scale older people's welfare facilities. Caregivers' behavior during the assisted evacuation was examined using virtual reality, where movement within a spacious physical environment was synchronized with that in the virtual environment. Six fire and smoke control designs included a fire in a dayroom or private room of the residents and a combination of smoke vents and compartmentation by a door between the dayroom and the corridor. Forty fire safety professionals participated in two evacuation procedures: “Attend,” in which all the residents were guided outside (a more elaborate procedure), and “Refuge,” in which residents remained in their rooms (a relatively simpler procedure). When a fire occurred in the dayroom, 94 % of the participants completed the Attend procedures when smoke vents were open, and the door to the corridor was closed. When a fire occurred in the private room, the smoke propagated to the corridor; however, 64 % of the participants completed the Refuge procedures when the smoke vent and exit door were open and the door to the dayroom was closed. Insightful remarks were acquired through participants' comments, such as how they lost their sense of direction during the repetition of entering and exiting many rooms, and that they could not judge the smoke's lethality based on just its appearance. Effective smoke control measures are crucial for securing the safety of both residents and caregivers in small-scale older people's welfare facilities.

本研究探讨小型老年福利院的防烟设计，使护理人员能协助老年居民疏散。在辅助疏散过程中，护理人员的行为使用虚拟现实进行检查，其中宽敞的物理环境中的运动与虚拟环境中的运动同步。六种火灾和烟雾控制设计包括在客厅或居民的私人房间里发生火灾，以及在客厅和走廊之间的一扇门结合排烟口和分隔。40名消防安全专业人员参与了两个疏散程序：“出席”，所有居民都被引导到外面（一个更复杂的程序），以及“避难”，居民留在自己的房间里（一个相对简单的程序）。当休息室发生火灾时，当通风口打开，走廊的门关闭时，94%的参与者完成了参加程序。当私人房间发生火灾时，烟雾蔓延到走廊；然而，当排烟口和出口门打开，通往休息室的门关闭时，64%的参与者完成了避难程序。通过参与者的评论，我们获得了一些有见地的评论，比如在重复进出许多房间的过程中，他们是如何失去方向感的，他们不能仅仅根据烟雾的外观来判断它的致命性。有效的烟雾控制措施对于确保小规模老年人福利设施的居民和护理人员的安全至关重要。

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引用次数: 0

Methodology for detecting firebrand generation and the analysis of influential variables in quantification 火种产生的检测方法及量化中影响变量的分析

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-08 DOI: 10.1016/j.firesaf.2025.104549

Fernando Ebensperger, Raphael Ogabi, Albert Simeoni

Firebrands play a dominant role in wildland fire propagation, especially in spotting, where embers are carried away from the main fire to ignite new areas. Three mechanisms govern their dynamics: generation, transport, and landing. While transport and landing have received more attention in the literature, generation remains poorly understood due to challenges in real-time quantification and detection. This shortcoming undermines fire spread models that require accurate estimation of particle properties and numbers. To address this, a UNet-based convolutional neural network (CNN) image processing method was developed to detect and segment firebrands from images and video. The model demonstrated over 80 % accuracy with limited training data, suggesting potential for field use with low-cost, heterogeneous imaging systems. Experiments were conducted in large wind tunnel (1.5m

\times

2.1m

\times

6 m) at uniform wind speeds up to 6.2 m/s and test velocities between 0.5 to 1.5 m/s. Douglas Fir samples were burned, and mass loss was measured using balances. Fuel positioning affected firebrand production: free samples (1.5 kg) exhibited multiple intense burning stages due to deformation, whereas restrained samples (0.76 kg) burned more uniformly. The proposed CNN approach offers a promising tool for supporting firebrand detection.

火种在野火传播中起着主导作用，特别是在发现时，余烬从主火中被带走点燃新的区域。三种机制支配着它们的动态：产生、运输和着陆。虽然运输和着陆在文献中得到了更多的关注，但由于实时量化和检测方面的挑战，对生成的理解仍然很少。这一缺点破坏了需要精确估计粒子性质和数量的火灾蔓延模型。为了解决这个问题，开发了一种基于unet的卷积神经网络（CNN）图像处理方法来检测和分割图像和视频中的火种。该模型在有限的训练数据下显示出超过80%的准确率，这表明该模型在低成本、异构成像系统的现场应用中具有潜力。实验在1.5m × 2.1m × 6m的大型风洞中进行，均匀风速为6.2 m/s，测试速度为0.5 ~ 1.5m /s。花旗松样品被烧毁，用天平测量质量损失。燃料的位置影响了火焰的产生：由于变形，自由样品（1.5 kg）表现出多个强烈的燃烧阶段，而限制样品（0.76 kg）燃烧更均匀。提出的CNN方法为支持火种检测提供了一个有前途的工具。

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引用次数: 0

Experimental and numerical investigations on the use of liquid nitrogen streams to suppress alcohol pool fires 利用液氮流扑灭酒精池火灾的实验与数值研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-08 DOI: 10.1016/j.firesaf.2025.104552

Aobo Liu , Alexandros G. Venetsanos , Michael A. Delichatsios , Yiannis A. Levendis

Liquid nitrogen (LN₂), a widely used cryogen, is proposed as an effective and environmentally benign fire suppression agent when tackling challenging fires, such as liquid hydrocarbon pool fires. Laboratory-scale experiments using liquid nitrogen were conducted to extinguish small alcohol pool fires (D = 20 cm). The axial temperature profile over the fuel surface and the mass history of the pool during the fire extinction were recorded and analyzed. The minimum quantity of LN₂ required for fire extinction was experimentally determined. A physics-based numerical model was developed using the ADREA-HF CFD code to simulate interactions between the cryogen, the flame envelope and the alcohol pool. Axial flame temperatures, oxygen concentrations and liquid nitrogen mass fractions were predicted numerically before and after the application of the cryogen. Modelling predictions for the liquid jet touchdown time, the amount of liquid mass reaching the ground and the ensuing fire extinction timeframes were in line with experimental observations. The purpose of this model is to predict the minimum amount of this cryogen required for effective pool fire suppression. Such a tool may be used to optimize the application of LN₂ for extinction of accidental fires of fuel spilled or spread on the ground.

液氮（LN2）是一种广泛使用的致冷剂，被认为是一种有效且环保的灭火剂，可用于应对具有挑战性的火灾，如液态烃池火灾。用液氮扑灭小型酒精池火灾（D = 20 cm）的实验室规模实验。记录和分析了灭火过程中燃料表面的轴向温度分布和燃料池的质量历史。通过实验确定了灭火所需的最小LN2量。利用ADREA-HF CFD代码建立了基于物理的数值模型，模拟了冷冻剂、火焰包壳和酒精池之间的相互作用。用数值方法预测了施加冷剂前后的轴向火焰温度、氧浓度和液氮质量分数。对液体喷射着陆时间、到达地面的液体质量以及随后的灭火时间框架的建模预测与实验观测结果一致。该模型的目的是预测有效灭火所需的最小制冷量。该工具可用于优化LN2的应用，以扑灭燃料溢出或扩散在地面上的意外火灾。

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引用次数: 0

Toxicant production in under-ventilated compartment fires assessed by laser absorption spectroscopy 用激光吸收光谱法评估通风不足的隔间火灾中毒物的产生

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-08 DOI: 10.1016/j.firesaf.2025.104534

Rayna Vreeland , Kyle L. Fetter , Nicolas S.B. Jaeger , Yi Yan , Xiuqi Xi , James L. Urban , Daniel I. Pineda , R. Mitchell Spearrin

The production of incomplete combustion products from the burning of wood, medium density fiberboard (MDF), and nylon in an under-ventilated compartment fire was investigated using a reduced-scale compartment. Species measurements of carbon monoxide (CO) and carbon dioxide (CO₂) were performed using Fourier Transform Infrared Spectroscopy (FTIR) and methane (CH₄), hydrogen cyanide (HCN), benzene (C₆H₆), ethylene (C₂H₄) and acetylene (C₂H₂) were measured with Laser Absorption Spectroscopy (LAS) with three different interband cascade lasers. The fuels were burned in three different crib configurations; only wood, only MDF, and a mixture of wood and nylon, to examine the production of different toxicants. During the experiments, measurements were collected of CO, CO₂, CH₄, HCN, C₂H₂, and C₆H₆ species from the gas exiting the compartment, gas temperature from inside the compartment, and the flow into and out of the compartment. Consistent with under-ventilated combustion, the temperature inside the compartment typically exceeded 600 °C. CO was measured during all experiments and was two orders of magnitude less than the measured CO₂ concentration. Significant amounts of unburned hydrocarbons were measured during all of the experiments, while HCN was only detected during the wood-nylon tests. Higher toxicant yields were measured for wood-nylon compared to pure wood and MDF.

使用缩小尺寸的燃烧室研究了木材、中密度纤维板（MDF）和尼龙在通风不足的燃烧室中燃烧产生的不完全燃烧产物。采用傅里叶变换红外光谱法（FTIR）测量了一氧化碳（CO）和二氧化碳（CO2）的组分，采用激光吸收光谱法（LAS）测量了甲烷（CH4）、氰化氢（HCN）、苯（C6H6）、乙烯（C2H4）和乙炔（C2H2）的组分。燃料在三种不同的婴儿床结构中燃烧；只有木材，只有中密度纤维板，以及木材和尼龙的混合物，来检查不同的有毒物质的生产。在实验过程中，测量了出舱气体的CO、CO2、CH4、HCN、C2H2和C6H6，舱内气体温度以及进出舱内的流量。与不通风燃烧一致，燃烧室内的温度通常超过600°C。在所有实验中都测量了CO，其浓度比测量的CO2浓度小两个数量级。在所有实验中都测量了大量未燃烧的碳氢化合物，而HCN仅在木-尼龙测试中被检测到。与纯木材和中密度纤维板相比，木质尼龙的有毒物质产量更高。

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引用次数: 0

The effect of water vapor on the flammability of fluorinated refrigerants 水蒸气对含氟制冷剂可燃性的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-10-07 DOI: 10.1016/j.firesaf.2025.104553

Gregory T. Linteris , Michael J. Hegetschweiler , Valeri I. Babushok

Possible replacements for the refrigerant R-134a have been proposed in previous work based on their flammability behavior in standard tests of the Heating, Ventilation, Air-Conditioning, and Refrigeration industry. The present work extends that behavior to more extreme conditions of temperature and humidity based on estimates of the overall reaction rate of the mixtures obtained from perfectly-stirred reactor (PSR) model simulations. The PSR simulations were found to predict the flammability conditions of the standard test well. For initial temperatures of 23 °C–60 °C and water vapor volume fraction in the oxidizer of 0 %–10 %, the effect of humidity on the overall reaction rate is predicted to be much larger than the effect of temperature, with an increase in the overall reaction rate up to about 2.5–9 times with most moist flames as compared to dry.

基于R-134a在采暖、通风、空调和制冷行业的标准测试中的可燃性，在之前的工作中提出了制冷剂R-134a的可能替代品。目前的工作将这种行为扩展到更极端的温度和湿度条件下，基于从完全搅拌反应器（PSR）模型模拟中获得的混合物的总体反应速率估计。发现PSR模拟可以预测标准测试井的可燃性条件。当初始温度为23°C - 60°C，氧化剂中水蒸气体积分数为0% - 10%时，湿度对总反应速率的影响预计要比温度的影响大得多，与干燥火焰相比，大多数湿火焰的总反应速率可提高约2.5-9倍。

引用次数: 0