彩虹粉引燃危险性实验研究

为了研究彩虹粉引燃危险性,应用固体燃烧速率试验仪初步甄别了彩虹粉传播燃烧能力,发现堆垛状彩虹粉固体火焰传播危险性较低;采用粉尘爆炸筛选装置,判定彩虹粉具有爆炸性;应用最小点火能测定装置测定彩虹粉粉尘云的最小点火能在24~60 mJ之间,最优爆炸浓度为1 167 g/m3;应用快速筛选量热仪测试,彩虹粉在227℃开始分解;固体自燃点测试仪显示彩虹粉在250℃附近会发生自燃。向彩虹粉内添加不同比例相近粒径分布的食用盐粉体进行抑爆研究,结果证明食用盐对彩虹粉具有明显的抑爆效果。     

Will climate change overwhelm fire management capacity?

Using anomalies calculated from General Circulation Model (GCM) climate predictions we developed scenarios of future fire weather, fuel moisture and fire occurrence and used these as the inputs to a fire growth and suppression simulation model for the province of Ontario, Canada. The goal of this study was to combine GCM predictions with the fire growth and suppression model to examine potential changes in area burned in Ontario due to climate change, while accounting for the large fire suppression activities of the Ontario Ministry of Natural Resources (OMNR). Results indicate a doubling of area burned in the Intensive and Measured fire management zones of Ontario by the decade of 2040 and an eightfold increase in area burned by the end of the 21st century in the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A2 scenario; smaller increases were found for the A1b and B1 scenarios. These changes are driven by increased fire weather conducive to large fire growth, and increases in the number of fires escaping initial attack: for the Canadian GCM's business-as-usual (A2) scenario, escaped fire frequency increased by 34% by 2040 and 92% by the end of the 21st century. Incorporating more detail on large fire growth than previous studies, our model predicts higher area burned under climate change than do these previous studies, as large numbers of high-intensity fires overwhelm suppression capacity.     

低压配电线路剩余电流断路器动作判据的研究

为了改善剩余电流断路器频繁误动作的问题,提出以偶次谐波变化率最小值阈值、工频变化量阈值、剩余电流动作整定值相结合的三重判据.首先,搭建活体触电试验平台,获取活体不同部位的多组触电试验数据,利用S变换提取触电波形谐波特征,并计算出触电时刻偶次谐波变比率最小值阈值和工频变化量阈值.其次,搭建人体触电仿真模型,发现存在相似的...     

Variable-density flow in heterogeneous porous media — Laboratory experiments and numerical simulations

Konz, M., Ackerer, P., Younes, A., Huggenberger, P., Zechner, E., 2009a. 2D Stable Layered Laboratory-scale Experiments for Testing Density-coupled Flow Models. Water Resources Research, 45. doi:10.1029/2008WR007118., a series of laboratory-scale 2D tank experiments were conducted and accurately simulated for density driven flow problems on homogeneous porous media. In the present work, we extended the numerical and experimental studies to heterogeneous problems. The heterogeneous porous medium was constructed with a low permeability zone in the centre of the tank and had well-defined parameters and boundary conditions. Concentration distributions were measured in high resolution using a photometric method and an image analysis technique. The numerical model used for the simulations was based on efficient advanced approximations for both spatial and temporal discretizations. The Method Of Lines (MOL) was used to allow higher-order temporal discretization. Three different boundary conditions, corresponding to different localizations of the inflow and the outflow openings at the opposite edges of the tank, were applied to investigate different flow scenarios in the heterogeneous porous medium flow tank. Simulation results of all three density coupled experiments revealed a density-dependent behavior of dispersion. Thus, a reduction of dispersivites was required to obtain a good matching of the experimental data. The high quality of the experiments enabled a detailed testing of numerical variable-density flow codes under heterogeneous conditions. Therefore, the experiments were considered to be reliable benchmark tests.     

地下储液罐抗爆炸地冲击作用的流固耦合有限元分析

储液罐的抗震性能虽然得到了较为深入的研究,但对其抗爆炸产生的地冲击作用的研究还十分罕见。本文通过建立流固耦合的数值分析模型,研究爆炸地冲击作用下地下立式储液罐的动力特性,包括储液晃动波高、罐壁的应力和应变、底板的提离和浮放储液罐的"象足"变形产生原因及破坏机理等。研究结果表明,储液罐在爆炸地冲击荷载和地震荷载作用下的动力响应有明显区别,地震荷载作用下的储液罐抗震验算方法不适用于爆炸地冲击荷载。     

非稳态条件下生物滴滤塔净化甲苯废气的实验

在接近于工业应用的非稳定条件下,以陶粒为填料,恶臭假单胞菌为单一菌源,甲苯为目标污染物,对生物滴滤塔的抗负荷冲击与抗饥饿能力进行研究。结果表明,停留时间及进气污染负荷的瞬间变化不会造成滤塔处理性能明显下降,仅为7%左右,12h内基本恢复,最大去除能力为136.49g/(m3.h);碳源与氮源的突然中断以及短期的闲置,对滤塔处理性能的影响均较小;填料层中水分的含量是影响滤塔处理性能的一个重要因素。     

舰船电子设备高强度冲击试验和抗冲击设计探讨

介绍了舰船冲击试验的发展状况和舰船电子设备高强度冲击试验方法,针对舰船电子设备在作战中遭受到来自水下武器爆炸所产生的非接触爆炸而引起的高强度冲击的特点,对舰船电子设备抗冲击设计进行了探讨.     

2219铝合金TIG焊缝激光冲击强化与腐蚀性能研究

目的 改善2219铝合金钨极氩弧焊焊缝的耐腐蚀性能。方法 采用激光冲击技术对焊缝进行强化处理,比较分析处理前后的表面残余应力、物相组成和元素状态,通过静态浸泡失重法和电化学试验测量腐蚀速率的变化。结果 经过激光冲击强化处理后,2219铝合金焊缝部位的元素状态没有改变,但焊缝区域的残余拉应力变为残余压应力。2219铝合金钨极氩弧焊接区域的自腐蚀电位明显下降,相比未经激光冲击处理的试件,焊核区和焊接过渡区的平均腐蚀电流分别减小了14%和12.7%,腐蚀速率分别减小了16.9%和12.9%。结论 激光冲击强化可以有效提升2219铝合金钨极氩弧焊焊缝区域的耐腐蚀性能,可以为提升特种装备安全性和轻量化提供技术参考。     

一种改进的模拟水灭火过程对抗式交互模型

针对虚拟火灾和燃气真火模拟训练系统中的灭火过程交互模型,研究了改进型对抗式系统动力学特性模型,并完成符号求解。讨论并提出了消防员行为、火场外部特征等要素变化条件下的模型架构,给出了连续时间区间的模拟灭火交互模型序列构成形式。分析了交互过程控制参数特性、功能和物理意义,对灭火过程的简化模拟方法进行了完整描述。运用模型编制了消防水灭火典型过程的参数化交互控制时序规律,给出了灭火过程交互模型实际应用的基本方法和步骤。     

抑制煤矿瓦斯爆炸传播的新技术设想

基于石油阻火装置对可燃气体爆炸传播的火焰具有淬熄作用,对压力波具有抑制作用,提出将金属丝网、波纹板型等几种结构用于抑制煤矿瓦斯爆炸传播的新思路,填补了阻火器在煤矿中应用的空白,为煤矿阻隔爆技术开拓出新的领域.