Fire Safety Journal最新文献_第5页

The effect of the smoke alarm obligation – Experiences from Germany based on the data from 1998–2022 烟雾报警器义务的影响——基于1998-2022年数据的德国经验

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-11 DOI: 10.1016/j.firesaf.2025.104590

Sebastian Festag

Germany has had over 20 years of experience with the mandatory use of smoke alarms in households, apartments and residential areas. Since the first smoke alarm obligation (SAO), all federal states have now gradually stipulated an SAO in their building codes over different points of time and with different details. In addition to the positive experiences in concrete practical cases, in which smoke alarms warned people of fire, the effect of this regulation measure can be demonstrated statistically by analysing the development of fire fatality risks for Germany overall and in the individual federal states based on significance tests (t-tests). The benefit of this measure is occasionally questioned in public discussion, although the existing studies show positive effects. So far, there has not been sufficient experience or samples for all federal states to provide a statistical answer. The study presented here examines the impact of the SAO in Germany over the period from 1998 to 2022. Compared to previous analyses, this is the first time that data for the period from 2017 to 2022 are included in the analysis. This provides, a differentiation between the SAO for new buildings (SAO_NB) and existing buildings (SAO_EB). The result of the study shows a significant effect in Germany and in 12 of 16 federal states. The positive effects have increased in recent years, as can be seen in comparison with the latest analyses.

德国在强制在家庭、公寓和住宅区安装烟雾报警器方面已有20多年的经验。自第一个烟雾报警器义务（SAO）以来，所有联邦州现在都逐步在其建筑规范中规定了不同时间点和不同细节的SAO。除了在烟雾警报器警告人们注意火灾的具体实际案例中取得的积极经验外，还可以根据显著性检验（t检验）对整个德国和各个联邦州的火灾死亡风险发展情况进行统计分析，从而证明这一管制措施的效果。尽管现有的研究显示出积极的效果，但这种措施的好处偶尔会在公众讨论中受到质疑。到目前为止，还没有足够的经验或样本让所有联邦州提供统计答案。本文介绍的研究考察了1998年至2022年期间SAO对德国的影响。与之前的分析相比，这是第一次将2017年至2022年的数据纳入分析。这提供了新建筑（SAONB）和现有建筑（SAOEB）的SAO之间的区别。研究结果显示，在德国和16个联邦州中的12个州，这种做法产生了显著影响。从最近的分析可以看出，近年来积极的影响有所增加。

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引用次数: 0

Buoyancy effects on combustion products from high-pressure hydrogen jet flames 高压氢射流火焰燃烧产物的浮力效应

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-11 DOI: 10.1016/j.firesaf.2025.104587

Thushadh Wijesekere, Marcus Runefors, Konrad Wilkens Flecknoe-Brown

Due to the lower radiative fraction and typically higher storage pressures, gas temperatures can often result in longer safety distances compared to radiative heat transfer for hydrogen jet flames. The high temperatures, however, also lead to a low density causing the flow to rise at a certain distance from the release. Unfortunately, a model to determine this distance, similar to what is available for unignited releases, is currently not available which this paper aim to provide. An experimental study was conducted investigating the buoyancy effect on ignited horizontal hydrogen jet releases with different release diameters. The invisible hydrogen plume was visualized using a Background Oriented Schlieren technique (BOS). The transition of the initial momentum-driven jet into a fully buoyancy-driven jet was estimated by following the gradient of the centerline of the plume. A model based on the Froude number of the release similar to the model for unignited releases was developed and the distance showed a very similar dependence on the Froude number, but giving consistently approximately 39% shorter distances.

由于较低的辐射分数和通常较高的储存压力，与氢喷射火焰的辐射传热相比，气体温度通常会导致更长的安全距离。然而，高温也会导致低密度，使流量在距离释放点一定距离处上升。不幸的是，一个模型来确定这个距离，类似于可用的未点燃的释放，目前是不可用的，这篇论文的目的是提供。通过实验研究了不同释放直径的点燃氢射流水平释放的浮力效应。使用背景定向纹影技术（BOS）对不可见的氢羽进行了可视化。根据羽流中心线的梯度，估计了初始动量驱动射流向完全浮力驱动射流的转变。建立了一个基于弗劳德数的模型，该模型与未点燃释放的模型相似，距离对弗劳德数的依赖非常相似，但始终给出约39%的短距离。

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引用次数: 0

Characteristic Compartment Fire Behaviour — A theoretical study encompassing a broader range of regimes 特征隔间火灾行为-一个理论研究，包括更广泛的制度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104589

A.H. Majdalani , I. Calderón , W. Jahn , J.L. Torero

Scaling analysis is used to characterise a series of ten different possible compartment fire scenarios as a function of compartment geometry and ventilation. In addition to the classic scenarios corresponding to Regime I and Regime II fires, eight additional cases were analysed showing that the flow characteristics are generally a function only of the Froude and Euler non-dimensional parameters. All ten scenarios can be described or bounded by the two classic and limiting regimes of behaviour, nevertheless five intermediate scenarios require spatial resolution to achieve a precise characterisation. Therefore, simple scaling analysis appears sufficient to deliver an adequate assessment of all parameters needed to define the heat transfer from the fire to the compartment until burnout of the available combustible compartment contents. The present analysis highlights the specific areas where spatial resolution is required and the potential limitations associated to the use of more detailed tools, such as CFD, for quantification in these specific areas.

尺度分析用于描述一系列十种不同的可能的隔间火灾场景，作为隔间几何形状和通风的函数。除了对应于状态I和状态II火灾的经典场景外，还分析了另外8个案例，表明流动特性通常仅是Froude和Euler无量纲参数的函数。所有十种情景都可以用两种经典和限制的行为模式来描述或限定，然而，五种中间情景需要空间分辨率来实现精确的特征描述。因此，简单的尺度分析似乎足以提供所需的所有参数的充分评估，以确定从火到隔间的热量传递，直到可用的可燃隔间内容物燃尽。目前的分析强调了需要空间分辨率的特定领域，以及在这些特定领域使用更详细的工具（如CFD）进行量化的潜在限制。

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引用次数: 0

Ignition time and heat release rate in upward flame spread: From bench to intermediate scale 向上火焰蔓延时的点火时间和放热率：从工作台到中间尺度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104566

Waseem Hittini , David Lange , Juan P. Hidalgo , Felix Wiesner

This research assesses the effect of two common assumptions in simplified flame spread models: (i) that the pyrolysis front propagates in one dimension and (ii) that ignition time (

t_{ign}

) and heat release rate per unit area (HRRPUA) values measured at bench scale can be utilised in simplified flame spread models. To that aim, the study introduces a methodology to measure time to ignition, time-dependent burning area, heat release rate per unit area, and ignition temperature for concurrent upward flame spread at intermediate-scale, while examining the feasibility of using these metrics to predict flame spread scenarios. The methodology employs a narrow-spectrum illumination source and thermocouple arrays to precisely track the pyrolysis front progression during flame spread experiment. Measurements were obtained for Poly(methyl methacrylate), and they can serve as reference points for researchers aiming to develop or refine testing protocols or perform sensitivity analyses for assumptions relevant to time to ignition and heat release rate models. Measurements were compared with cone calorimeter data from standard and modified testing protocols in the literature. Post-ignition removal of external heating reduced HRRPUA values, aligning them more closely with intermediate-scale experiments, while spatial heat flux distribution changed the time to ignition towards the values that were measured in intermediate-scale. The impact of the solid ignition parameters on the flame spread rate was evaluated individually using a simplified flame spread model. The proposed methodology provides a means to refine extrapolation methods for solid ignition parameters.

本研究评估了简化火焰传播模型中两个常见假设的影响：(i)热解锋面在一维上传播；（ii）在台架尺度上测量的点火时间（tin）和单位面积放热率（HRRPUA）值可用于简化火焰传播模型。为此，该研究引入了一种方法来测量点火时间、随时间变化的燃烧面积、单位面积的放热率以及在中等规模下同步向上火焰蔓延的点火温度，同时检查使用这些指标预测火焰蔓延情景的可行性。该方法采用窄谱照明光源和热电偶阵列来精确跟踪火焰蔓延实验过程中的热解前沿进程。获得了聚（甲基丙烯酸甲酯）的测量值，它们可以作为研究人员的参考点，旨在开发或完善测试方案，或对点火时间和热释放率模型相关的假设进行敏感性分析。测量结果与文献中来自标准和修改的测试方案的锥量热计数据进行比较。点火后去除外部加热降低了HRRPUA值，使其与中尺度实验更接近，而空间热通量分布使点火时间向中尺度实验值靠拢。采用简化的火焰传播模型，分别评价了固体点火参数对火焰传播速率的影响。提出的方法为固体点火参数的外推方法提供了一种改进方法。

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引用次数: 0

Understanding the role of buoyancy and inertia in wind-aided vegetative fires 了解浮力和惯性在风助植物火灾中的作用

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-08 DOI: 10.1016/j.firesaf.2025.104588

Abhinandan Singh , Juan Cuevas , Reza Ziazi , Pedro Reszka , Albert Simeoni

The combined effects of buoyancy and inertia forces are studied for wind-aided vegetative fires. Two fuels - Pinus palustris (PP) and Pinus rigida (PR) are tested at five different wind conditions. The flame geometrical parameters are normalized using the flame height and scaled against the inverse of the Froude number (

Fr

). A power-law relationship is observed between all the flame geometrical parameters and

1 / Fr

. The instantaneous rate of spread is calculated using an image analysis algorithm by separating flame impingement and flame spread. The behavior of the average rate of spread is explored by evaluating radiative heat flux in the preheating region. The fluctuating rate of spread (

R^{'}

) is calculated from the instantaneous and average rate of spread values. The spectral analysis of

R^{'}

shows a range of frequencies that are an integer multiple (or harmonics) of the characteristic frequency for a given experiment. Strouhal number (St) evaluated using the characteristic frequency multiplied by the leaf area index of the pine needle bed shows a linear behavior against

1 / Fr

.

研究了风助植物火灾中浮力和惯性力的联合作用。两种燃料——palustris Pinus （PP）和Pinus rigida （PR）在五种不同的风力条件下进行了测试。火焰几何参数使用火焰高度归一化，并根据弗劳德数（Fr）的倒数进行缩放。火焰几何参数与1/Fr呈幂律关系。通过分离火焰撞击和火焰蔓延，采用图像分析算法计算瞬时传播速率。通过估算预热区的辐射热流密度，探讨了平均扩散率的变化规律。从差值的瞬时速率和平均速率计算差值的波动速率（R '）。R '的频谱分析显示了一个频率范围，它是给定实验的特征频率的整数倍（或谐波）。用特征频率乘以松针床叶面积指数计算的斯特劳哈尔数（St）与1/Fr呈线性关系。

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引用次数: 0

Preventing fire-induced brittle collapse of steel tubular space trusses for reliable early warning: From mechanisms to design strategy 防止钢管空间桁架火灾脆性倒塌的可靠预警：从机理到设计策略

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104586

Jinyu Li , Shaojun Zhu , Guo-Qiang Li , Yongchang Wang

Steel tubular space truss structures are widely utilized in large-space buildings but are highly susceptible to collapse under fire conditions, posing a threat to firefighters. This study conducts extensive parametric analyses to understand all fire-induced collapse modes and mechanisms of steel tubular space trusses. There are four collapse modes, of which three are categorized as ductile and one is classified as brittle due to buckling of the web members in compression. Under the brittle collapse mode, it is difficult to reliably predict the collapse of the structure for real-time early warning. This paper recommends the elimination of this failure mode in all likely fire scenarios. A design strategy is proposed to ensure that the brittle buckling failure mode of web members does not happen before that of the adjacent members in tension, whose failure is ductile. Besides, the available escape time after the early warning level is issued can be changed by adjusting the critical temperatures of the compression web members. Numerical examples demonstrate that the available escape time can increase from 0 s to over 2 min, which increases the escape time for firefighters in large-span steel structures.

钢管空间桁架结构广泛应用于大空间建筑，但在火灾条件下极易倒塌，对消防人员构成威胁。本研究进行了广泛的参数分析，以了解钢管空间桁架的所有火灾倒塌模式和机制。有四种破坏模式，其中三种为延性破坏模式，一种为脆性破坏模式，这是由于腹板在压缩下的屈曲造成的。在脆性破坏模式下，很难对结构的破坏进行可靠的预测和实时预警。本文建议在所有可能的火灾场景中消除这种故障模式。提出了一种保证腹板构件脆性屈曲破坏模式不先于相邻构件脆性屈曲破坏模式发生的设计策略。通过调整压缩腹板构件的临界温度，可以改变预警级别发布后的有效逃生时间。数值算例表明，在大跨度钢结构中，有效逃生时间由0 s增加到2 min以上，增加了消防员的逃生时间。

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引用次数: 0

Towards modeling tree-to-tree fire spread in wildland urban-interface (WUI) fires 林地城市界面（WUI）火灾中树对树的火灾传播模型研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104550

Jorge Valdivia, Xiuqi Xi, Albert Simeoni, James L. Urban

Wildfires in the Wildland-Urban Interface (WUI) have intensified in recent years due to climate change and continued development of communities at the WUI. Defensible space–reducing vegetation near structures–is a mitigation strategy, but its performance under wind-driven fire conditions remains unclear. This study integrates controlled experiments with Fire Dynamics Simulator (FDS) modeling to investigate ignition between trees subjected to wind-aided flame spread. A custom-designed propane burner, representing fire exposure similar to a 2 MW tree fire, exposed downwind Douglas-fir trees under flow velocities of 1.0 and 2.0 m s⁻¹, across varying separation distances. Total and radiative heat fluxes were measured using water-cooled gauges, and ignition behavior was evaluated through logistic regression. Flame impingement emerged as the dominant ignition mechanism, with convection significantly increasing heat transfer to downwind trees at short separation distances. Simulations reproduced key trends in heat flux and flame geometry but over-predicted radiation and under-predicted convection, especially at short separations. Critical ignition distances increased with wind speed, highlighting the role of wind-driven flame elongation and the need for flow-aware defensible space recommendations. The experiments provide insight into the use of computational fire modeling to inform defensible space guidelines tailored to specific environmental and fire conditions.

近年来，由于气候变化和城市交界面社区的持续发展，城市交界面地区的野火愈演愈烈。可防御的空间——减少建筑物附近的植被——是一种缓解策略，但它在风力驱动的火灾条件下的表现仍不清楚。本研究将对照实验与火焰动力学模拟器（FDS）模型相结合，研究了风助火焰传播下树木之间的点火情况。一个定制设计的丙烷燃烧器，代表了类似于2兆瓦树木火灾的火灾暴露，在1.0和2.0 m s- 1的流速下，在不同的分离距离上暴露下风道格拉斯冷杉树。用水冷计测量总热流和辐射热通量，并通过逻辑回归评估点火行为。火焰碰撞是主要的点火机制，对流显著增加了短间隔距离下风向树木的传热。模拟再现了热通量和火焰几何形状的关键趋势，但高估了辐射，而低估了对流，特别是在短间隔时。临界点火距离随着风速的增加而增加，这突出了风驱动火焰延伸的作用，以及对流动感知防御空间建议的需求。这些实验提供了对使用计算火灾模型的洞察力，以告知针对特定环境和火灾条件量身定制的防御空间指南。

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引用次数: 0

A novel fire hazard evaluation method for cable sheaths under various ageing conditions 不同老化条件下电缆护套火灾危险性评估新方法

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104572

Hui Liu, Wenqiang Wang, Long Yan, Zhisheng Xu

Fire hazard is one of the most serious security threats to the service cable under different environmental conditions, and comprehensive evaluation is critical for fire safety. A novel evaluation method of fire hazard for cable sheaths after various ageing treatment was established based on entropy weight method (EWM), analytic hierarchy process (AHP), grey relational analysis (GRA), and technique for order preference by similarity to an ideal solution (TOPSIS) method. By analyzing factors that leaded to fire accidents, 15 evaluation indicators were determined from three aspects, including ignition, heat and smoke hazards. Combined with the characteristics of each evaluation method, the AHP-EWM method was used to obtain combination weight values, and the comprehensive evaluations for the fire hazards of the sheaths under different ageing conditions were realized by the TOPSIS-GRA method. The results show that the heat hazard of low-smoke halogen-free sheath is higher, while the smoke hazard of PVC sheath is larger. Simultaneously, the negative impact of hygrothermal condition is the most significant, succeeded by the salt spray condition, while the weaken effect of thermal condition is the smallest. In contrast to the traditional evaluation method of fire hazards, the evaluation results from the TOPSIS-GRA method are more accurate and reliable.

火灾是不同环境条件下服务电缆最严重的安全威胁之一，综合评价是保障服务电缆防火安全的关键。基于熵权法（EWM）、层次分析法（AHP）、灰色关联分析法（GRA）和理想解相似性排序偏好法（TOPSIS），建立了不同老化处理后电缆护套火灾危险性评价方法。通过分析导致火灾事故的因素，从着火、热和烟雾危害三个方面确定了15个评价指标。结合各评价方法的特点，采用AHP-EWM法获得组合权重值，采用TOPSIS-GRA法实现对不同老化条件下护套火灾危险性的综合评价。结果表明，低烟无卤护套的热危险性较高，而PVC护套的烟危险性较大。同时，湿热条件的负面影响最为显著，其次是盐雾条件，而热条件的弱化作用最小。与传统的火灾危险性评价方法相比，TOPSIS-GRA方法的评价结果更加准确可靠。

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引用次数: 0

Reappraisal of Jin's visibility through fire smoke experiment: Insights into signage visibility and the impact of ambient light 通过火烟实验重新评价Jin的可见度：对标识可见度和环境光影响的洞察

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104573

Wai Kit Cheung , Jakub Bielawski , Lukas Arnold , Xinyan Huang , Wojciech Węgrzyński

Jin's experiments in the 1970s contributed to fire evacuation research, but only examined relatively high ambient light levels. By replicating the Jin's experimental setup and varying ambient light level, we explore the relationship between smoke extinction coefficient, background illumination and signage emitting light intensity under low-light real-world emergency scenarios. Firstly, we confirm Jin's observation of a linear relationship between smoke extinction coefficient (

σ

) and visibility distance (

V

), although our measurements of

σ

are 7–11 % higher under equivalent signage luminance. Our findings on the

σ

versus normalized brightness

π L_{t} / E

at a 15.5 m distance align with Jin's results, while a 20 % discrepancy is observed at 10.5 m and 5.5 m distances. At high ambient light (180 lx), the

K = σ V

is comparable in Jin's experiment (from 5 to 8) and this work (from 4.7 to 9.5). However, at low ambient light (less than 22 lx), the signage remains visible in higher smoke extinction coefficients (with K from 6 to 11). The critical extinction coefficient decreases by nearly 40 % for every 5 m increase in visibility distance. This work deepens the understanding of smoke visibility under a dark fire environment, which may help guide fire signage design and inspire new fire evacuation research.

金在20世纪70年代的实验为火灾疏散研究做出了贡献，但只检查了相对较高的环境光水平。通过复制Jin的实验装置和不同的环境光水平，我们探索了在低光的现实世界紧急情况下，烟雾消光系数、背景照度和标牌发光强度之间的关系。首先，我们证实了Jin对烟雾消光系数（σ）和可见距离(V)之间的线性关系的观察，尽管在等效标识亮度下我们的σ测量值高出7 - 11%。我们在15.5 m距离处的σ与归一化亮度πLt/E的结果与Jin的结果一致，而在10.5 m和5.5 m距离处观察到20%的差异。在高环境光（180 lx）下，K=σV在Jin的实验（从5到8）和本工作（从4.7到9.5）中是相当的。然而，在低环境光（小于22 lx）下，标识在较高的烟雾消光系数（K从6到11）下仍然可见。能见度每增加5 m，临界消光系数降低近40%。本研究加深了对暗火环境下烟雾可见度的认识，有助于指导防火标识设计，启发新的火灾疏散研究。

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引用次数: 0

Impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire 高浓度烟雾气溶胶对建筑火灾中雷达电磁波传播的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-03 DOI: 10.1016/j.firesaf.2025.104568

Song Wang , Jing Geng , Wenguo Weng

This study investigates the impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire scenarios. A computational model based on Mie scattering theory and existing databases was developed to evaluate the influence of smoke aerosols on radar signals. Additionally, a voxel-based Finite-Difference Time-Domain (FDTD) simulation method was designed to model complex random media, and simulations were conducted to validate the computational model. An experimental platform was also constructed to assess the impact of high-concentration smoke on radar electromagnetic waves, utilizing three types of radars: NVA-R641, X4M03, and IWR6843. Data collected under typical smoke conditions revealed attenuation coefficients of approximately 0.03 dB/m at 2.95 GHz, 0.37 dB/m at 8.75 GHz, and 0.76 dB/m at 60 GHz. These results support the theoretical model and demonstrate the feasibility of the simulation approach. This research provides a comprehensive framework for understanding and predicting the effects of high-concentration smoke aerosols on radar systems in building fire scenarios, offering valuable tools for optimizing radar performance and enhancing the reliability of life-saving operations in smoke-filled environments.

研究了建筑火灾场景下高浓度烟雾气溶胶对雷达电磁波传播的影响。基于Mie散射理论和现有数据库，建立了烟雾气溶胶对雷达信号影响的计算模型。此外，设计了一种基于体素的时域有限差分（FDTD）模拟方法来模拟复杂随机介质，并进行了仿真验证。利用NVA-R641、X4M03和IWR6843三种型号的雷达，搭建了一个实验平台来评估高浓度烟雾对雷达电磁波的影响。在典型烟雾条件下收集的数据显示，衰减系数在2.95 GHz时约为0.03 dB/m，在8.75 GHz时约为0.37 dB/m，在60 GHz时约为0.76 dB/m。这些结果支持了理论模型，并证明了仿真方法的可行性。本研究为理解和预测建筑火灾场景中高浓度烟雾气溶胶对雷达系统的影响提供了一个全面的框架，为优化雷达性能和提高烟雾弥漫环境中救生操作的可靠性提供了有价值的工具。

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引用次数: 0