基于情景的建筑火灾风险分析方法及CFAST软件应用

提出基于情景的建筑火灾风险分析方法,它通过3个步骤即起火分析、确定未来情景集和确定风险分析结果来计算建筑物火灾风险大小。从一个建筑单体出发,通过过程模拟的手段得到其未来可能会出现的各种"情景",计算各"情景"中的指标,通过综合分析得到风险分析的结果。并通过算例说明了基于情景的火灾风险分析方法的实现过程。最后通过分析北京市近几年的火灾历史数据、设定影响火灾发展的各种因素和CFAST软件模拟的手段,得到建筑火灾年期望损失率作为风险的度量值。     

南非HS抑爆系统性能的试验研究

为了验证南非HS抑爆系统的安全性能,对HS系统进行基本性能试验和系统的整机抑爆效果试验。该系统的喷洒滞后时间、成雾时间、有效雾面持续时间和喷洒率4个基本参数的性能进行了测量和计算。在HS系统的整机抑爆效果试验中,进行4次不同的试验。试验结果表明,HS系统能迅速地产生具有足够的面积和持续时间的喷雾屏障,有效地抑止瓦斯和煤尘的燃烧与爆炸。HS系统具有较好的安全性能和较为广阔的应用前景。     

高层住宅火灾风险综合评估体系研究

火灾风险评估对于高层住宅的火灾事故预防有着重要意义。本文分析了高层住宅火灾风险因素,并结合现行的建筑设计防火规范,建立了高层住宅火灾风险评价指标体系,将高层住宅火灾风险评价指标分为三级,一、二级指标采用重要性排序的方法,三级指标采用专家打分的方法,各指标权重使用结构熵权法进行计算。最后,利用该方法进行实例分析,对高层住宅的实际火灾风险进行评估,得出其火灾等级,验证了所提评估方法的可行性。对制定高层住宅火灾控制方案有着重要的意义。     

Configuration predictions of large liquefied petroleum gas (LPG) pool fires using CFD method

Liquefied petroleum gas (LPG) has potential pool fire risks due to its flammability. The configuration of pool fires plays a significant role when applying the solid flame model or point source model to assess the risks from heat radiation. However, no existing correlations can precisely predict the configuration of large LPG (100% propane) pool fires. To enhance the fundamental understanding on how pool diameter and wind velocity can influence the configuration of large LPG pool fires, an experimentally validated Computational Fluid Dynamics (CFD) model is employed to simulate fires using different burning rate models. Fire temperature profiles, flame heights, and flame tilts predicted by the CFD model were compared with empirical models and experimental data. Accordingly, new correlations for flame height and flame tilt as functions of pool diameter D and wind velocity u_w have been developed. The comparisons demonstrate that the new correlations have the best overall accuracy in the prediction of flame height and tilt for large LPG pool fires under different conditions (10 m ≤ D ≤ 20 m, 0 ≤ u_w ≤ 3 m·s⁻¹).     

Methane Emission Estimates from Landfills Obtained with Dynamic Plume Measurements

Methane emissions from 3 different landfills inthe Netherlands were estimated using a mobileTuneable Diode Laser system (TDL). The methaneconcentration in the cross section of the plumeis measured downwind of the source on a transectperpendicular to the wind direction. A gaussianplume model was used to simulate theconcentration levels at the transect. Theemission from the source is calculated from themeasured and modelled concentration levels.Calibration of the plume dispersion model isdone using a tracer (N₂O) that is releasedfrom the landfill and measured simultaneouslywith the TDL system. The emission estimates forthe different locations ranged from 3.6 to 16 m³ ha^-1 hr^-1 for the differentsites. The emission levels were compared toemission estimates based on the landfill gasproduction models. This comparison suggestsoxidation rates that are up to 50% in springand negligible in November. At one of the threesites measurements were performed in campaignsin 3 consecutive years. Comparison of theemission levels in the first and second yearshowed a reduction of the methane emission ofabout 50% due to implementation of a gasextraction system. From the second to the thirdyear emissions increased by a factor of 4 due tonew landfilling. Furthermore measurements wereperformed in winter when oxidation efficiencywas reduced. This paper describes themeasurement technique used, and discusses theresults of the experimental sessions that were performed.     

采用锥形量热仪(CONE)研究和评价新型可膨胀石墨防火涂料

利用锥形量热仪(CONE)实验获得的热失重速率(MLR)、热释放速率(HRR)、有效燃烧热(EHC)、比消光面积(SEA)、CO2、CO和点燃时间(TTI)等参数对可膨胀石墨防火涂料与传统的膨胀型防火涂料的阻燃性能、烟毒释放、阻燃机理进行了对比研究。结果表明,与传统的膨胀型防火涂料相比,可膨胀石墨防火涂料由于在热降解过程中成炭量较高,炭层具有更好的热稳定性,因而其阻燃和隔热性能更为优良,具有更长的耐燃时间,且烟毒释放少,安全性能更高。     

电工电子产品燃烧产物的腐蚀损坏效应

电工电子产品陷入火灾后所产生的腐蚀性燃烧产物,可能会对电路和电工电子元器件的性能造成不同程度的损坏,使设备出现故障。测量和评估燃烧产物的腐蚀损坏效应对于保证与安全有关的电工电子设备正常运行是十分必要的。     

怠速条件下汽车排气污染物在排气尾流中扩散特性的实验研究

通过实验的方法对怠速条件下汽车排气污染物在排气尾流中的扩散特性进行了研究.测定了怠速条件下汽车排气尾流中的污染物体积分数及其分布,并比较分析了3种不同类型汽车的污染物排放体积分数及其变化.实验结果表明,怠速时汽车排气尾流中的污染物体积分数按照近似指数函数的趋势迅速降低到接近大气背景值;不同类型汽车排气尾流中的污染物体积分数的差别非常明显;排气方向对汽车排放污染物的扩散及其分布具有重要的影响.研究工作可以为怠速工况下汽车排气污染物对周围环境的影响评价提供更多的有用信息.     

城市建筑火灾评价指标及其权重处理

针对城市建筑火灾的危害严重程度,结合建立的城市建筑火灾危险性评价指标体系,运用Fuzzy－AHP法确定了各评估因子的权重,指出了今后的努力方向。     

可燃材料火灾中的毒性评估方法

建筑火灾中致人死亡的因素除了热以外 ,更多的是因为烟气的毒性。为此 ,重点介绍了几种常用的烟气毒性的评估方法 ,并对这几种评估方法进行了比较。基于对这些评估方法的描述 ,阐明了烟气毒性研究未来的发展方向。