新能源汽车火灾预防及应急救援

本文从新能源汽车的结构特征出发,分析了新能源汽车火灾的原因及特点,提出了适用于新能源汽车的火灾预防及灭火救援措施、技术和方法,为消防救援队伍或车主扑灭新能源汽车火灾提供参考。     

汽车火灾探测研究现状及发展趋势

阐述了近年来汽车火灾造成的损失,分析了国内外对于汽车火灾开展的实验研究工作,指出目前国内外学者着重于汽车火灾发生后且达到一定破坏能力时的火灾特性研究。提出汽车火灾探测研究的发展趋势,强调分析汽车火灾发生原因机理的重要性,并从电气系统、油路系统、排气系统几方面分析汽车或者发生原因。     

汽车火灾原因及预防

对汽车火灾的原因、特点进行分析,提出了汽车火灾的防范措施及汽车火灾灭火对策。     

汽车火灾原因分析及预防措施

针对汽车本身结构复杂、引起火灾因素多的问题,对汽车火灾的主要特点及原因进行了分析,并提出了针对性的汽车火灾预防建议和扑救措施。     

汽车整车火灾试验视频监控系统的设计应用

在汽车火灾原因调查的过程中,通过汽车燃烧蔓延痕迹的分析确定起火部位、起火点是认定汽车火灾原因最关键的步骤。而对火灾痕迹特征准确辨识的前提是对火灾燃烧特点及蔓延过程的熟悉和了解。通过自主研发的全方位同步视频监控系统,采集汽车火灾蔓延过程中火焰、烟气的蔓延途径和关键时间节点,为分析研究汽车火灾蔓延痕迹特征,从而确定起火部位、起火点提供有力的技术支持。     

国外车辆火灾原因调查技术研究

数据表明,国外发达国家车辆火灾发生的数量已经呈现了逐年下降的趋势,研究国外先进的车辆火灾调查技术、研究方法将对我国车辆火灾的预防、车辆的设计改进、标准法规的制定起到积极的作用。以国外汽车工业发达国家车辆火灾调查文献为基础,并参考大量汽车工业与车辆火灾危险性相关的生产、设计标准和实验方案等资料,提出了我国车辆火灾调查方面应注意的问题和进一步研究的方向。     

新能源汽车火灾特点与事故调查分析

为了给新能源汽车火灾防控提供一些参考,利用案例分析法,以一起电动汽车火灾为例,分析新能源汽车火灾特征,探究新能源汽车火灾事故调查过程,并提出了几点新能源汽车火灾事故预防建议,得出新能源汽车火灾具有危险系统多、原因表现多样、机理高度复杂等特征,事故危害较大等结论。因此,为避免动力电池热失控引发的整车烧损事故,应进一步加强新能源汽车灭火技术标准化管理,改进新能源汽车电池,降低新能源汽车火灾发生率及危害程度。     

一起因汽车机械故障引发火灾的调查

通过对一起汽车火灾事故调查与认定过程的分析,说明了汽车火灾现场勘验、调查询问和物证鉴定的方法步骤,介绍了相关汽车火灾痕迹物证的识别和运用方法,对汽车发动机舱机械故障的发现、鉴别、提取、检验的具体过程和方法进行了详细阐述,就此起汽车火灾原因认定的事实和依据作了充分说明,以为类似火灾的调查提供参考。     

一起汽车电气火灾的火因认定

介绍了一起汽车电气火灾的火灾调查工作,分析了汽车火灾的特征,认定了火灾原因,并对在不利因素情况下,如何认定火灾原因提出建议。     

从一起汽车火灾原因调查谈汽车火灾预防对策

通过一起汽车火灾案例进行分析,阐述了该起火灾调查的过程、起火部位的认定,并探究该起汽车火灾的原因,提出了汽车火灾预防对策。     

香烟引燃特性的实验研究

通过香烟火源引燃几种家庭常见物品的实验,研究香烟火的引燃特性。实验结果显示:香烟火温度虽高,但不一定引起有焰燃烧,可能只有炭化痕迹或持续阴燃;判断材料有无蓄热能力,不能只考虑材料自身组分的燃烧特性,而是要具体问题具体分析;蓄热材料也不一定能被香烟火点燃;阴燃反应相对缓慢,产生较多有毒气体,没有火焰,潜伏期长,不易察觉。     

林地腐殖质火阴燃特征研究

为了掌握林地腐殖质火阴燃温度变化特征。以南京栖霞区丁山的地表腐殖质可燃物为研究对象,将可燃物种类、可燃物燃烧深度、含水量、风速分别作为自变量,在其他条件相同的情况下分组实验对照,建立了初步的阴燃蔓延模型,得出相关实验数据。数据表明,枯立木阴燃温度最高能达到689 ℃;地表土阴燃燃烧深度越深,阴燃持续的时间就越长,发生在土层表面横向的阴燃火蔓延决定了阴燃林火的范围,此外,因为阴燃的地下燃烧特征,阴燃会在地下将可燃物烧净,而地表没有燃烧,从而呈现空洞特征;当含水率大于42.3%时,腐殖质复燃的可能性极低;通过对比观察结果,风速对阴燃的复燃影响最为显著,燃烧深度则影响阴燃时间和燃烧范围。相关研究为今后的森林消防工作提供部分理论依据和实验数据支撑。     

Experimental study of the effect of water spray on the spread of smoldering in Indonesian peat fires

Peatland fires remain a major contributor of environmental problems in Indonesia. Several studies on peat fire suppression have been conducted with multiple methods, such as quarrying, water spray, artificial rain, and foam spray. This research is focused on laboratory scaled experiments of Indonesian peat smoldering fire behaviour and suppression by a water mist system. The peat used in this work was obtained from two different locations, namely Papua and South Sumatra, Indonesia. During the suppression tests, the intensity of the water mist spray was varied by changing the distance between the nozzle and the peat surface. Meanwhile, the time periods of spray were 15 min (short period of suppression) and approximately 2 h for full suppression until the peat fire was extinguished. The peat temperature and the total mass lost during the smoldering reaction were recorded to get the burning rate ratio for each sample. The spread rate of the smoldering process was identified by the changes in the local temperatures of the peat bed. The results show that the spread rate of the smoldering combustion front was affected by particle size and permeability of peat material. The short duration of water suppression failed to extinguish the peat fires. A re-ignition phenomenon was identified due to the persistence of stored heat in the core of the peat. In addition, the total water required to fully suppress both peat fires is about 6 L/kg peat.     

密闭腔室内高压七氟丙烷喷放与局部过冷研究

摘 要：针对高压七氟丙烷气体喷放行为,建立了密闭腔室高压气体小孔喷射动态发展与演化模型,基于数值分析研究了高压七氟丙烷小孔喷射过程中的组分场、温度场和速度场等特性,并开展了相应喷放试验研究。计算结果表明,七氟丙烷喷射后易形成气体回卷,继而在障碍物靠近喷射口一侧形成七氟丙烷稀薄区域。七氟丙烷发生意外喷射时,尽管在喷口附近产生的最低温度低至-20 ℃,当七氟丙烷喷射口距离电子设备超过1.75 m时,则相应的低温影响往往在可接受范围。     

Collapsed spring observations in arson investigations: A critical metallurgical evaluation

Observation of collapsed coiled (steel) furniture springs has been utilized for several decades or more by arson investigators as an indicator of whether an accelerant or smoldering source (such as a cigarette) caused a fire. This paper cites the contradictory literature, synopsizes metallurgical phenomena operative when coiled steel springs are subjected to fires, and presents empirical data from U.S. Federal Bureau of Investigation (FBI) Laboratory testing. It is concluded that observation of the collapsed state of coiled furniture/bedding springs is not a reliable indicator of whether a fire was initiated by a smoldering cigarette or accelerated by the presence of a hydrocarbon.     

棉被阴燃火灾实验研究

针对烟头引燃棉被的火灾案例,实验测量烟头的表面温度及热辐射强度,得到烟头表面最高温度可达289 ℃,很容易引燃棉被等可燃物.通过无被套棉被的阴燃实验和有被套棉被的阴燃转明火实验发现,在没有被套的情况下,棉絮间空隙较大,无法积聚热量,只能阴燃而无明火;有被套情况下,产生的热量大部分被阻隔在棉被内部,散热速度较慢,提供了棉被阴燃转明火所需的热量.     

变电站电缆沟火灾探测试验与数值仿真研究

为探讨火灾探测器灵敏度对电缆沟火灾响应的影响程度,验证火灾监控系统的准确性,应用点式温度探测器、点式烟雾探测器、电缆式感温探测器和吸入式烟雾探测器4种火灾探测器,在标准变电站电缆沟防火分区内进行了全尺寸电缆火灾试验,测试不同灵敏度火灾探测器的火灾报警序列。根据电缆沟的实际尺寸,利用FDS搭建模拟明火和阴燃两种不同火灾场景,对不同灵敏度火灾探测器的温度场、有毒气体质量浓度和火灾报警顺序进行了分析和讨论。试验结果表明,在变电站电缆沟火探测中,电缆式感温探测器、吸入式烟雾探测器、点式感烟探测器火灾平均响应时间分别为41.2,111.4,331.8 s;吸入式感烟探测器的灵敏度对探测结果影响较大,其火灾报警响应时间比电缆型线性温度探测器约延迟50%。     

Results from a Full-Scale Smoke Alarm Sensitivity Study

A series of 24 full-scale experiments was conducted to examine the effects of alarm type (photoelectric, ionization, and dual sensor), alarm location, fabric type (100% cotton and 100% polyester), polyurethane foam density, ignition scenario, and room configuration, on smoke alarm performance. A two-level, fractional factorial design of eight experimental configurations was developed around the five factors: fabric type, foam density, fire location, ventilation, and ignition scenario. A structure, designed to represent a single-story home or apartment, was constructed inside the Large Fire Laboratory at the National Institute for Standards and Technology for the experiments. The fire source was a chair mockup consisting of a seat and back cushion of a specific cover fabric and foam density, weighing between 5.5 kg and 8.3 kg. It rested on a metal frame and was subjected to a small propane gas flame, or an electric cartridge heater to initiate smoldering. Each experimental configuration was replicated three times. Smoldering fires were allowed to progress until they naturally transitioned to flaming fires except for one test that was terminated early due to time constraints. The smoldering to flaming transition times ranged from (81 to 182) min. Each fire progressed for a time sufficient to produce multiple hazards (smoke, heat, and toxic gases). All alarms tested were purchased from retail outlets and activated at their preset levels. Photoelectric, ionization, and dual photoelectric/ionization alarms were co-located at multiple locations to facilitate comparisons of each alarm type, and different designs of the same type of alarm. For smoke alarms in the room of fire origin, it was observed that each of the five factors had an effect on the measured alarm times that was primarily a result of fire growth rate (fabric type, foam density, and ignition scenario), or smoke dilution and transport (fire location and ventilation). The photoelectric alarm responded quicker on average than ionization alarm in two of four smoldering fire configurations, responding before the ionization alarm in all 6 trials, while the ionization alarm responded before the photoelectric alarm in two of three trials for the other two configurations. The ionization alarm responded quicker on average than photoelectric alarm in all four flaming fire configurations, and responded before the photoelectric alarm in all 12 flaming fire trials. One dual alarm had the fastest average alarm time for all four smoldering fire configurations, and responded first in 11 of the 12 trials. It also yielded faster average alarm times than the other dual alarm in seven of eight configurations, and was the first dual alarm to respond in 22 out of 23 trials where dual alarms were present.     

空调通风工况地铁站台初期火灾烟气运动规律

通过在地铁站台进行的火灾实体试验,对车站各种空调通风条件下棉绳阴燃火与聚氨酯明火的烟气速度、温度进行监测与分析,研究地铁中具有格栅镂空吊顶的车站站台在不同空调通风工况下火灾初期烟气运动的规律。多点风速探头和温度记录探头设置在火源正上方以及在距火源水平距离约2 m远的4个位置,分别设置在镂空格栅吊顶的上方和下方。在空调通风工况下,送风对烟气的上升有不同程度的抑制作用,一定程度上延长了火源的燃烧时间。对于阴燃火源,烟气温度的降低导致烟气很难升至吊顶上方。     

基于QPSO-BP 神经网络的火灾预警算法

为了进一步提高油库消防系统的安全性,针对其火灾报警信息系统进行了改进,构建基于量子粒子群算法优化BP神经网络的火灾智能预警算法,以温度、烟雾浓度以及CO 浓度数据作为神经网络的输入,以无火、明火以及阴燃火的概率作为神经网络的输出。使用量子粒子群算法优化BP 神经网络运行中随机产生的权值和阈值,加快神经网络收敛到期望误差的速度,增强全局搜索能力。通过MATLAB 软件对智能火灾预警算法的模型进行仿真,模型输出的火情概率与实际值基本吻合。设计了多传感器数据采集设备,获取火灾现场数据,输入网络模型,能够有效识别明火、阴燃火和无火情况,验证了该算法可提高消防预警系统的准确性。