Runehamar tunnel fire tests

Five large-scale fire tests, including one pool fire test and four HGV mock-up fire tests, were carried out in the Runehamar tunnel in Norway in year 2003. New data and new analyzes are presented in this paper, together with a short summary of previous work on these tests. Heat release rate (HRR), radiation, fire spread, gas production, backside wall temperature, visibility, backlayering, fire growth rate, gas temperature, flame length, ventilation and pulsation are investigated. Simple theoretical models are developed to estimate and predict these parameters. The correlations developed can be used by engineers working on fire safety in tunnels.     

Mass fire characteristics in large-scale tests

The suburban sprawl into rural and wildland areas increases the potential for damage from mass fires, either through nuclear attack or natural disaster. But defenses against the devastating effects of mass fires suffer from lack of quantitative information on behavior of large intense fires. Laboratory-scale testing is not enough —it is very likely that a different set of controlling factors take over when a fire grows to a certain size and intensity. A series of large-scale tests using woodland fuels in ordered piles simulating built-up residential areas has been started to provide the missing data. Preliminary tests in the series are reported here. Note: This paper was presented at a fire research symposium sponsored by the Office of Civil Defense at Washington, D.C., May 17, 1965. It is based on a report “Mass Fires and Fire Behavior” (U.S.Forest Service Research Paper PSW-19, 1964, Contract Nos. OCD-OS-62-173 and OCD-PS-64-32 for the Office of Civil Defense) and is availiable from the Clearinghouse of Federal Scientific and Technical Information, U.S. Department of Commerce, Springfield, Virginia 22151. Note: This paper was presented at a fire research symposium sponsored by the Office of Civil Defense at Washington, D.C., May 17, 1965. It is based on a report “Mass Fires and Fire Behavior” (U.S.Forest Service Research Paper PSW-19, 1964, Contract Nos. OCD-OS-62-173 and OCD-PS-64-32 for the Office of Civil Defense) and is availiable from the Clearinghouse of Federal Scientific and Technical Information, U.S. Department of Commerce, Springfield, Virginia 22151.     

Model scale tunnel fire tests with longitudinal ventilation

Results from a series of tests in a model tunnel (1:23) are presented. Tests were carried out with longitudinal ventilation under different fire conditions. Wood cribs were used to simulate the fire source, which was designed to correspond to a scaled-down HGV (Heavy Goods Vehicle) fire load. The parameters tested were: the number of wood cribs, type of wood cribs, the longitudinal ventilation rate and the ceiling height. The heat release rate, fire growth rate, maximum gas temperature beneath the ceiling, temperature distribution, total heat flux at floor level, flame length, and back-layering length were investigated. Correlations for these parameters were investigated and proposed for longitudinal flow in tunnels.     

Model scale tunnel fire tests with automatic sprinkler

The study focuses on the performance of an automatic sprinkler system in a model scale tunnel with longitudinal ventilation. A total of 28 tests were carried out in a 1:15 model scale tunnel using an automatic sprinkler system with glass bulbs. The maximum heat release rate, energy content and failure of the automatic sprinkler system were analysed. The results show that high ventilation rates and low water flow rates result in a failure of the automatic sprinkler system in a longitudinal ventilated tunnel fire. The main reason for the failure under the tested water flow rates was the effect of the longitudinal flow on the fire development and the hot gas flow close to the sprinklers. The fire development and the activation heat release rate of the first activated bulb are intimately related to the ventilation velocity. The fire spread to the neighbouring wood crib was investigated and a presentation of tests conducted using a deluge system are given.     

Description of small and large-scale cross laminated timber fire tests

A large-scale fire test was conducted on a compartment constructed from cross laminated timber (CLT). The internal faces of the compartment were lined with non-combustible board, with the exception of one wall and the ceiling where the CLT was exposed directly to the fire inside the compartment. Extinction of the fire occurred without intervention. During the fire test, measurements were made of incident radiant heat flux, gas phase temperature, and in-depth temperature in the CLT. In addition, gas flow velocities and gas phase temperatures at the opening were measured, as well as incident heat fluxes at the facade due to flames and the plume leaving the opening. The fuel load was chosen to be sufficient to attain flashover, to achieve steady-state burning conditions of the exposed CLT, but to minimize the probability of uncertain behaviors induced by the specific characteristics of the CLT. Ventilation conditions were chosen to approximate maximum temperatures within a compartment. Wood cribs were used as fuel and, following decay of the cribs, self-extinction of the exposed CLT rapidly occurred. In parallel with the large-scale test, a small scale study focusing on CLT self-extinction was conducted. This study was used to establish: the range of incident heat fluxes for which self-extinction of the CLT can occur; the duration of exposure after which steady-state burning occurred; and the duration of exposure at which debonding of the CLT could occur. The large-scale test is described, and the results from both the small and large-scale tests are compared. It is found that self-extinction occurred in the large-scale compartment within the range of critical heat fluxes obtained from the small scale tests.     

隧道火灾温度测试方法、升温曲线的分析应用

介绍了隧道火灾实验中测量不同车辆燃烧时车内和隧道温度的方法及不同车辆燃烧时车内外隧道代表性测点温度随时间变化的情况;并介绍了国外在隧道混凝土结构耐火灾性能评价中常用的温度一时间升温曲线.同时,应用IS0834标准升温曲线,对20个混凝土立方体试件进行的抗压强度实验,并通过扫描电子显微镜(SEM),对实验后的混凝土试件进行的微观分析.     

几种火灾探测器在公路隧道中的应用

如何迅速探测公路长隧道的火灾,一直是国内外研究的课题。隧道火灾报警是隧道安全系统非常重要的一部分。隧道火灾探测器的种类很多,本文根据隧道几种常见火灾探测器的工作原理、结构、性能特点及优缺点,简述其在高速公路隧道上的应用,并为公路隧道火灾探测器的选择提供参考。     

Gas temperature measurements using fibre Bragg grating during fire experiments in a tunnel

Gas temperature measurements with thermocouples are affected by radiation. This effect means that the temperature measured by a thermocouple can be far from the actual gas temperature. To study this effect and to compare the thermocouple readings with the readings of a fibre Bragg grating (FBG) sensor, fire experiments were performed in a model-scale tunnel. In this paper the results from two such fire experiments are presented. The temperatures measured using thermocouples with different diameters and the FBG sensor are compared and discussed. The “true” gas temperature, corrected for radiation effects from the thermocouples, was calculated from the results from the thermocouples with different diameters. The results show that the temperature measured by the FBG sensor is closer to the “true” gas temperature than is the case for any of the thermocouples used in these tests.     

大型火灾图像数据集的设计及建立

摘 要：当前火灾图像识别方法主要依赖于大数据集,在样本不足时会出现探测结果不可靠。针对国内外普遍缺乏火灾图像样本的问题,根据火灾探测算法开发和评估需求,建立样本数量充足且包含多种应用场景的大型火灾图像数据集。为确保火灾图像数据集完备与有效,通过数据集开发并评估多个图像型火灾探测算法,分别对数据集的开发有效性和评估有效性进行试验。试验结果表明：数据集具有较好的普适性和有效性,可以为图像型火灾探测算法的研究提供基础平台。     

综合管廊内防火隔板对电缆火蔓延的影响

以苏州城北路综合管廊标准段为参考建立FDS全尺寸火灾数值仿真模型,模拟分析综合管廊电力电缆舱室发生火灾时的火势发展形势、温度分布。在管廊左、右两侧设置了4层电缆,分有、无防火隔板两个场景研究防火隔板对火势发展及温度分布的影响。结果表明：未设置防火隔板时,管廊内发生火灾时火势的发展方向首先以横向蔓延为主,顶部电缆随着火势的扩大及烟气聚集传热发生燃烧最后向管廊的其他区域蔓延。设置防火隔板后,竖向火的蔓延时间延缓了约40%,管廊内最高温度降低约18%。     

基于FDS的T型电缆隧道火灾探究

为了获取T型电缆隧道火灾参数,研究隧道内空气温度及火灾烟雾浓度随时间、空间的分布情况,利用FDS软件建立T型电缆隧道模型,对电缆隧道火灾进行全尺寸模拟.通过对模拟实验数据处理和分析,给出了电缆隧道发生火灾时烟气和氧气体积分数以及纵向温度的变化规律,为现实灭火救援以及火灾中逃生提供理论依据.     

岩后隧道火灾内部特征温度影响范围研究

为量化隧道内部发生火灾后的特征温度影响范围,以人眼高度的特征温度（70 ℃）和顶棚高度处的特征温度（334 ℃）作为影响范围界定参数。采用FDS数值模型方法研究了岩后隧道事故中单火源、多火源情况下的温度分布规律。研究结果表明：隧道中心线位置,无论是单火源还是多火源,人眼特征高度处的温度影响范围皆小于顶棚处温度影响范围。多火源时,在相邻火源区域间,人眼特征高度处温度出现明显叠加效应,而顶棚高度处则未出现该现象,但其区域内温度远高于人眼特征高度处,且衰减所需时间更长。以464 m长的岩后隧道为研究对象,30 s后距离第一火源50 m范围内的汽车已经达到可燃温度,360 s后距离第一火源184 m的煤车尚未达到可燃温度。人眼特征高度处烟流叠加区域温度呈现出极不稳定的动态升高,但最高温度较顶棚处低。叠加区域以外,顶棚处温度衰减比人眼特征高度处更为缓慢,但影响范围会持续扩大,受时间效应影响明显。     

隧道车辆火灾成因及应对策略

随着公路隧道交通的快速发展以及汽车火灾事故的不断增加,隧道中发生车辆火灾的概率越来越大。分析隧道车辆火灾的特点,包括蔓延迅速、救援困难等,探讨火灾成因如电气系统故障、油路系统故障、发动机系统故障等,并提出相应的火灾预防对策。     

大型商业综合体火灾特点分析及防火对策

在社会经济不断发展的今天,大型商业综合建筑物的数量也在不断增加,在居民日常生活需求被满足的同时,由于大型商业综合体建筑内人员密集,结构复杂等缘故,大量消防隐患也出现在居民的身边.本次研究将以目前我国大型商业综合体建筑的运行现状作为基础,分析大型商业综合体建筑消防事故出现的原因,并在这一基础上制定相应的改善措施.     

隧道复合防火设计

用于水底隧道混凝土结构防火保护的系统措施,以特殊吊挂件吊挂金属龙骨的柔性方式,有效吸收因管片涨缩、沉降、变形等有害因素,使附着其上的防火结构不会被破坏;同时选用具备优良的抗冲击强度和抗折破坏荷载表面板材,有效吸收车辆高速进出、会车时的正、负压冲击波.     

火源尺寸对地铁隧道火灾临界风速的影响

以地铁区间隧道为研究对象,考虑有无列车两种情况,采用火灾动力学模拟软件FDS 5.5.3对不同火源尺寸条件下控制地铁隧道火灾烟气不向上游蔓延的临界风速进行数值模拟。结果表明:火源功率一定时,有无列车情况下火源高度、长度及宽度均对临界风速产生影响。无列车时,临界风速随着火源高度、长度、宽度的增加逐渐减小;有列车时,临界风速随着火源高度、宽度的增加先增大后减小,随着火源长度的增大而递减。     

The cleveland aircraft fire tests

On June 30 and July 1, 1966, tests were conducted to evaluate high expansion foam’s ability to extend the time for which an aircraft passenger cabin environment would remain survivable during a post-crash five. While some results tend to confirm those of similar tests, others may shed new light on the problem.     

Temperatures during fire tests on structure and its prediction according to Eurocodes

The paper reports on an experimental programme to investigate the global structural behaviour of a compartment in the three-storey steel frame building in a plant of the Mittal Steel Ostrava exposed to fire before demolition. The research project of the Czech Technical University in Prague was focussed on the examination of the temperature development within the various unprotected structural elements and its connections, the corresponding distribution of horizontal forces and the behaviour of the laterally unrestrained beams during the natural fire. The experiment also allowed studying of the heating of external elements, the influence of connection in a wall of sandwich panels, the temperature development in light timber-based panel and the degradation of the timber concrete composite element. Before the compartment fire, a local fire was prepared to verify the models of the temperature development in an unprotected column. The comparisons to the simplified calculations by European standards are included in the text to show their strong and weak points in prediction of temperatures of gas and structural elements during fire.     

Model scale railcar fire tests

A series of tests has been performed in a model of a typical passenger train compartment (railcar). The tests were carried out on a scale of 1–10. The main purpose of the tests was to investigate if it is possible to calculate the heat release rate for a flashed over train compartment with simple mathematical expressions derived for ordinary compartment fires. The combustion that takes place outside the windows was considered in the study. The parameters that were varied include: the ventilation, the fuel load and the type of interior surface material. In all tests, one door was open and the number of windows varied from all windows closed, to all windows opened. The ignition took place in the corner of the model compartment opposite the door opening.