气力输送水泥粉体装置灭木垛火试验研究

为了研究水泥粉体扑灭木垛火灾的可行性,通过自行设计的气力输送水泥粉体装置开展木垛火的灭火试验研究,利用温度采集装置和摄像机等仪器测试水泥粉体灭火前后木垛火的变化规律.结果表明,气力输送水泥粉体能有效抑制木垛表面明火,显著降低木垛火的燃烧温度,其中水泥粉体主要通过堆积覆盖作用进行灭火,而过大的木垛高度和孔隙率对水泥粉体灭...     

受限空间内脉冲细水雾灭木垛火试验

为研究循环动作时间对细水雾扑灭木垛火效果的影响,搭建了脉冲细水雾灭火试验平台,改变细水雾循环动作时间,在1.5m×1.5m×1.5 m的受限空间内进行了灭火试验,分析了脉冲细水雾作用过程中温度场及氧含量的变化。研究表明,脉冲细水雾对木垛火有很好的抑制作用,能够在较短的时间内熄灭木垛表面明火,但无法彻底扑灭木垛内部火;针对试验中的木垛尺寸及形式,喷10s、停10s是一个最佳的脉冲时间参数,在该工况下灭火效率最高、灭火效果最好。     

高压细水雾灭木垛火实验研究

在受限空间内,设计了小尺寸木垛火实验燃烧平台,通过实验研究了木垛火在细水雾作用下温度、灭火时间、热辐射强度的变化规律。研究表明,与普通细水雾相比,含添加剂细水雾使木垛明火消失时间缩短了1.6倍,且能更好地抑制木垛火温度。细水雾能够有效地衰减木垛火热辐射强度,并且含添加剂细水雾衰减木垛火热辐射强度效率更高。水雾停喷后,细水雾作用下的木垛温度较添加剂细水雾作用下的木垛内部温度有较高的回升,最高温度达到250℃。     

改性干水灭火剂灭木垛火试验研究

新型干水灭火剂因其高含水量和特殊核壳结构,具有良好的灭火效果。为探究干水对木垛火的灭火效果,自行制备磷酸二氢铵改性干水并开展小尺寸木垛火灭火试验。结果表明：干水灭火剂能够扑灭小尺寸木垛火且不发生复燃,改性干水的控火时间仅为8 s,控火过程中火焰高度持续快速下降,而干粉灭火剂的控火时间则为20 s,喷撒结束39 s后发生复燃;改性干水对火焰区及木垛的温度抑制效果均优于干粉灭火剂,控火时间内,改性干水作用下木垛表面的平均温降速率高达17.00℃/s,是干粉灭火剂作用下平均温降速率的1.94倍;改性干水能够有效降低木垛内部温度,在喷撒50 s内,木垛中心的平均温降速率为8.78℃/s,而干粉灭火剂缺乏冷却作用,木垛中心的平均温降速率仅为6.10℃/s,无法有效抑制阴燃。     

探火管式超细粉体灭火装置灭A类火效能研究

通过1m3全淹没灭火实验,研究探火管式超细粉体灭火装置对A类木垛火和电缆火的灭火效能及机理,并与现有直接探火管式气体灭火装置进行对比分析。结果表明,探火管式超细粉体灭火装置可快速有效扑灭木垛和电缆明火及阴燃火,灭火抑制10min后不发生复燃。实际应用时,建议探火管式超细粉体灭火装置的灭火剂最低设计浓度为90g/m3。探火管式超细粉体灭火装置的灭火效能约是七氟丙烷灭火装置的6倍,约是二氧化碳灭火装置的21倍。     

氮气灭火系统对受限空间木垛火的窒息特性研究

氮气灭火系统因其环保节能、稳定性高等特点,在建筑消防领域展现出巨大的发展空间。为进一步拓宽氮气灭火系统的应用领域,通过缩尺寸模型实验分析了氮气灭火系统对受限空间木垛火的灭火时间、氧气浓度、火焰温度等窒息特性参数的影响。结果表明,氮气灭火系统对受限空间中木垛火展现了良好的窒息灭火效果,其中不同火源功率的木垛火在受限空间中的灭火时间接近。     

高压喷雾消防车射流系统研发及灭火试验

介绍了所研发的高压喷雾消防车射流系统工作原理及高压喷雾枪、柱塞泵等主要部件,开展了室内木垛火、室外木垛火、室外油盘火、不同混合比灭火剂灭火等火灾试验,并与水罐消防车、压缩空气泡沫消防车进行了灭火效果对比。试验结果表明,高压喷雾消防车射流系统能高效扑灭多种典型的室内外火灾,系统用水量小、操作简单,用于消防车具有机动灵活、战斗展开与转移便捷、所需操作人员少等特点。系统已通过专家评审,半年灭火实战检验效果良好。     

灭火试验用木垛燃烧特性研究

采用空白燃烧试验研究常用木垛引燃燃料的自身燃烧热释放规律,并采用油盘火引燃方式对自动灭火装置检测常用的小木垛进行了燃烧试验,获取了热释放速率及总放热量特性。以自动灭火装置和灭火药剂的应用特点和工作方式为出发点,采用四角点火方式对同类型木垛进行了引燃试验,对比分析两种点火方式所获得的燃烧热释放参数曲线规律和区别的产生原因。采用四角点火方式的木垛燃烧进程阶段性特征更为明显,适宜于考察自动灭火装置类产品对于初起火灾的反应和抑制效果,以及考察灭火药剂对木垛燃烧的最大扑灭能力。     

木垛火热释放速率的试验研究

基于耗氧原理,开展了不同尺寸木垛的热释放速率测定试验,得到不同尺寸木垛的热释放速率曲线。进一步分析得到,研究范围内木垛燃烧热释放速率峰值与外表面面积之间为不含常数项的二次多项式关系,以及木垛单位外表面面积的热释放速率强度与外表面面积间为线性正比例关系。并得到了特定热释放速率强度木垛尺寸的确定方法,方便了试验人员设计及使用木垛火火源。     

基于汽车专用底盘的抛沙灭火设备研制

针对目前消防采用沙土灭火时采用人工取沙运沙存在灭火效率低且救援危险性高的问题,对大型抛沙灭火车抛沙灭火装置进行研发。设计的抛沙灭火装置可以实现不同距离、不同角度、不同高度的范围内灭火,提高救援速度与救援效率,可以快速将货箱里的沙土转移到着火点进行覆盖灭火,降低了人员的工作强度,提高了灭火效率,同时有效保障救援人员的安全。     

A study on the fire extinguishing characteristics of deep-seated fires using the scale model experiment

NFPA 18 is used as a standard for the performance evaluation of wetting agents used in fire fighting. The performance evaluation of the wetting agent involves three tests: a wood crib fire test, a deep-seated fire test, and a wood fiberboard penetration test. In this study, a scale model experimental device, which can evaluate both extinguishing performance and penetration performance at once, was prepared to evaluate the performance of a wetting agent in various types of porous materials. Then, this result was compared with the results of an NFPA 18 test to validate the result of the novel test. Three types of commercial fire-fighting solutions and water were used as extinguishing agents in the experiment. The experimental materials used in this performance evaluation were wood crib which is used in the existing class A fire test and wood flour from New Zealand pine trees which has 75% of the domestic market share in wood cribs. The discrimination of the study result used in this study to determine penetration and extinguishing performances was found to be equivalent to the results of the NFPA18 test. Moreover, the study established the validity of the scale model that could check on both penetration and extinguishing performance, permitting a more economical and efficient performance evaluation of wetting agents.     

Extinguishing Class A fires with multipurpose chemicals

We investigated the extinguishing properties of multipurpose dry chemicals using openregime cribs of two sizes. One measured 20.3 by 20.3 by 15.2 cm, and the other 50.8 by 50.8 by 38 cm. A crib fire, which has both flaming and smoldering contributions, is primarily extinguished when the burning surfaces are covered or smothered by a gas phase of the original multipurpose agent or a product of the agent's decomposition. The overall effectiveness of each dry chemical depends on its particle size, the degree of its decomposition and/or vaporization, and the openness of the crib. All particles of an agent below a unique limiting size completely decompose and/or vaporize in the crib fire and have the same extinguishing effectiveness. Particles above the limit have no measurable effectiveness. Scaling is considered on the basis of the minimum extinction weight per unit of exposed wood surface.Carhart is recently retired from the U.S. Navy Technology Center for Safety and Survivability at the Naval Research Laboratory in Washington, D.C.     

A study of portable water mist fire extinguishers used for extinguishment of multiple fire types

This paper describes both theoretical and experimental studies on the application of a portable water mist extinguisher in suppressing multiple fire types. Two prototype portable water mist fire extinguishers were developed and their feasibility in extinguishing flammable liquid, cooking oil and wood crib fires, and for use in fires associated with an energized target was investigated. The interaction between water mist and the fire plume was studied by analyzing the instantaneous process of fire extinction, and fire and fuel temperature profiles. Both theoretical analysis and experimental results showed that the extinguishing mechanisms and process as well as water mist characteristics required (such as water flux density, droplet size and spray coverage) change with the types of fires encountered. The portable water mist extinguisher with appropriate mist characteristics was able to extinguish multiple fire types.     

闭式旋转型雨淋喷头的试验研究

介绍闭式旋转型雨淋喷头的结构和工作原理。通过动态热性能试验验证闭式旋转型雨淋喷头玻璃球热反应灵敏度,进行了下垂安装方式两个高度的布水性能试验,通过木垛火灭火试验和不同工作压力的转速试验检验其灭火控制性能,并在0.2 MPa的工作压力下试验连续喷水性能。试验结果表明:闭式旋转型雨淋喷头结构设计利于热传递,具有良好的动态热性能和布水均匀性,且达到轻危险级洒水密度要求,工作稳定可靠。     

七氟丙烷对磷酸铁锂储能电池的灭火效果

以七氟丙烷灭火剂为灭火介质,研究其在不同喷射方式下对磷酸铁锂储能电池火灾的灭火效果。研究发现：不同喷射方式均可在8 s 内扑灭明火,但灭火效果存在一定差异。七氟丙烷垂直喷射时,扑灭明火仅用2 s,且瞬时降温速率最大可达43 ℃/s。抑制复燃时间长,持续升温时间以及持续冒烟时间短。在喷射方式的选择上应尽量保证灭火剂喷口能够覆盖在电池正上方,这样能够最大化发挥七氟丙烷的灭火效果。     

全氟己酮和细水雾抑制三元锂离子电池火灾有效性研究

锂离子电池热失控是造成电动汽车火灾事故的首要因素。文章概述了车用锂离子电池热失控火灾危险性及抑制方法,并开展了全氟己酮、细水雾对车用三元锂离子电池热失控火灾的灭火试验。结果表明,三元锂离子电池热失控时表面最高温度超过500℃,表面最大升温速率达到18.93℃/s;全氟己酮灭火剂和细水雾均能有效扑灭电池初期明火,但在灭火后数分钟内电池发生复燃。两种灭火剂均能有效降低电池表面最高温度和最大升温速率。     

Improvement of water mist's fire-extinguishing efficiency with MC additive

MC additive is a new generation of additives that is being developed by our research group to improve the fire-extinguishing efficiency of water mist. MC additive not only will not corrode metal and is non-toxic to human beings, but also greatly improves the fire extinguishing efficiency. In this paper, a phenomenological study is conducted into the effect of MC additive on water mist's fire-extinguishing efficiency through the base of an ethanol fire, a diesel fire and a wood crib fire. The experimental results are explained using the chemical suppression mechanisms combined with physical suppression mechanisms.     

常压和低压下锂离子电池灭火特性研究

研究气体灭火剂在航空货运低压环境与常压环境下对 18650 型三元锂离子电池的灭火特性。基于低压实验舱和气体灭火系统,使用全氟己酮分别在常压 101 kPa 和低压 30 kPa下对热失控的锂离子电池进行灭火,记录灭火现象、温度变化,并分析空气中各相关气体组分变化。结果表明,常压下热失控表现为向外爆燃和持续明火燃烧,延长了灭火时间;低压低氧浓度环境在一定程度上减缓锂离子电池的热失控燃烧放热反应,有助于控制峰值温度,提高灭火效率;灭火过程中,灭火剂会增加氧气的消耗,低压时氧气消耗大于常压;常压下电池内部反应和二次燃烧更充分,向外释放更多热量,生成了更多二氧化碳,而低压时会有更多的一氧化碳产生。