利用计算机模拟研究地铁火灾气温控制

分析了地铁火灾中烟气运动的物理模型和数学模型，并结合工程实例，对地铁隧道内发生火灾情况下，各种通风方案进行计算机模拟。并确定了最佳紧急通风方案。     

油库火灾爆炸危险性分析

对某油库火灾爆炸危险性进行了定性分析,找出了发生火灾爆炸事故的主要危险因素,并提出了相应的对策.     

锂离子电池组分层主动均衡研究

目的 针对实际装备中使用的串联锂离子电池组的不一致性问题,提出一种基于Buck-Boost电路和反激式变压器均衡电路的分层主动均衡构架.方法 以荷电状态(SOC)作为均衡标准,制定均衡策略,建立锂离子电池二阶等效电路模型以及开路电压(OCV)特性曲线来进行参数辨识与SOC估计.实现电池组内相邻电池单体间的能量转移以及电池组间任意模组到整体的能量双向传递.最后在Matlab/Simulink中搭建均衡模型进行仿真验证.结果 分层主动均衡构架相比传统单一相邻电池均衡构架具有更好的均衡结果,其均衡效果提升了43.04％,均衡时间缩短了24.4％,均衡效率提高了12.61％.结论 该分层主动均衡构架充分发挥了两种主动均衡的优点,改善了电池组的不一致性问题,并提高了整个电池组的充放电容量.     

Environmental problems in a coal mining area affected by coal fires ——A case study in Ruqigou Coalfield, Ningxia, China

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Chromatographic measurement of molecular markers of sources of atmospheric aerosol particles

Various organic compounds in aerosol particles in ambient air near a coniferous forest fire in Boulder, Colorado were identified as molecular markers of wood burning and forest fires. Particle samples were collected by filtering small volumes of air. The samples were analysed using thermal desorption followed by gas chromatographic separation and detection, a highly sensitive analytical method. Several compounds unique to softwood combustion were identified in the samples. Additionally, a predominance of odd-carbon-numbered n-alkanes over the corresponding even-carbon-numbered n-alkanes was observed. This predominance is a well-documented molecular pattern indicative of epicutical waxes in plants.     

Toward Meaningful Snag-Management Guidelines for Postfire Salvage Logging in North American Conifer Forests

Abstract:  The bird species in western North America that are most restricted to, and therefore most dependent on, severely burned conifer forests during the first years following a fire event depend heavily on the abundant standing snags for perch sites, nest sites, and food resources. Thus, it is critical to develop and apply appropriate snag-management guidelines to implement postfire timber harvest operations in the same locations. Unfortunately, existing guidelines designed for green-tree forests cannot be applied to postfire salvage sales because the snag needs of snag-dependent species in burned forests are not at all similar to the snag needs of snag-dependent species in green-tree forests. Birds in burned forests have very different snag-retention needs from those cavity-nesting bird species that have served as the focus for the development of existing snag-management guidelines. Specifically, many postfire specialists use standing dead trees not only for nesting purposes but for feeding purposes as well. Woodpeckers, in particular, specialize on wood-boring beetle larvae that are superabundant in fire-killed trees for several years following severe fire. Species such as the Black-backed Woodpecker ( Picoides arcticus ) are nearly restricted in their habitat distribution to severely burned forests. Moreover, existing postfire salvage-logging studies reveal that most postfire specialist species are completely absent from burned forests that have been (even partially) salvage logged. I call for the long-overdue development and use of more meaningful snag-retention guidelines for postfire specialists, and I note that the biology of the most fire-dependent bird species suggests that even a cursory attempt to meet their snag needs would preclude postfire salvage logging in those severely burned conifer forests wherein the maintenance of biological diversity is deemed important.     

基于热-结构耦合分析的液化石油气储罐失效预警判定*

为研究火灾中球罐应力场分布情况,找到球罐失效破裂条件,以液化石油气为研究对象,基于球罐稳态热响应,通过ANSYS热-结构耦合有限元分析法进行研究。结果表明:充装率85%的液化石油气球罐最高温度部位出现在气相区,约619.66 ℃;最大应力值出现在气液交界处,约615.18 MPa;得到球罐破裂失效时温度值和应力值,并设置2次预警值。研究结果可为液化石油气储罐失效预警提供参考和判定依据。     

基于空气幕与排烟系统的隧道火灾烟气控制研究*

为研究隧道火灾时空气幕与排烟系统复合模式下的烟气蔓延规律,优化选择防排烟方式,以某越江隧道为研究对象,运用FDS数值模拟方法探究射流速度、排烟量和空气幕与排烟口间距对防排烟效果的影响。结果表明:空气幕与排烟口间距对射流特性与烟气蔓延有较强影响,间距为30 m的控烟效果最佳;空气幕与机械排烟复合作用的控烟效果远优于每个独立系统,可实现可靠挡烟和有效排烟;当火源功率20 MW时,随空气幕射流速度的增加挡烟效果有所增加,但射流速度不宜过大,取20~30 m/s;机械排烟对温度与可见度影响比空气幕作用效果显著,一定程度上增加排烟量可降低所需气幕射流速度;综合考虑防排烟的有效性和经济性,取射流速度为20 m/s、排烟量为100 m3/s为最优防排烟组合方式。     

基于贝叶斯估计的多探测器火警判定方法研究*

为应对感烟探测器的大量误报对消防应急响应带来的挑战,考虑目前以感烟探测器为主的火警设施误报率高且短期内难以全部更换的特点,提出基于贝叶斯估计的多探测器火警判定方法,通过多个探测器的报警时间间隔计算火源位置的后验概率分布,并提出火警真实度概念,为火警判定提供依据。结果表明:使用多探测器耦合模型时每增加1个探测器可将误报率降低约4个数量级,该方法在探测器正常、部分失效、误报的情景下均能有效判别火警。     

相邻木结构建筑火灾蔓延临界值研究*

为研究相邻木结构建筑火灾由已燃建筑传递至未燃建筑的临界值,利用突变理论与数值模拟分别研究相同条件下贵州省典型木结构建筑火灾发展过程中发生突变现象的临界值,并采用实验手段对前2种方法所测得的结果进行验证,从而证明尖点突变理论在相邻木结构建筑火灾蔓延临界值预测中的可行性与有效性。建立描述相邻木结构建筑火灾发展过程的能量守恒方程,通过对能量守恒方程的推导,得到相邻木结构建筑火灾突变势函数。结果表明:在相邻木结构建筑火灾发展过程中,火焰由已燃建筑传递至未燃建筑这一过程具有尖点突变的特征,计算出的火灾蔓延临界值为892.2 K;根据数值模拟找到已燃建筑传递至未燃建筑的状态,此时的临界值为881.5 K:2组简易实验测得的临界温度分别为903.2,889.8 K,与突变理论预测值和数值模拟结果相比,3种方法误差不大,因此可认为利用尖点突变对相邻木结构建筑火灾突变临界值进行预测具有可行性。