隧道受限火灾合理纵向通风风速范围研究*

为探究公路隧道不同受限程度火灾的适宜纵向通风风速,基于FDS模拟分析5种纵向通风速度下不同近壁距离火源顶棚下方烟气最高温度的分布特性、烟羽流倾角及烟气分层状况,提出合理纵向通风风速范围。研究结果表明:在隧道中心线上近火源下游,顶棚下方的最高温度沿纵向均呈指数衰减。不同贴壁距离和纵向通风风速下,均出现烟气分岔流动,随着贴壁距离减小羽流撞击处温升、火羽流偏移角显著增加。当风速小于1.6 m/s时,火源上游出现大量高温烟气回流;而当风速超过2.4 m/s时,分岔流动现象越明显,各偏移角变小,火源下游逐渐后移的烟气层严重失稳。因此,不同受限程度下火灾合理纵向风速为1.6~2.4 m/s。     

含氯化亚铁添加剂细水雾灭火有效性的实验研究

为了提高常规细水雾的灭火有效性,拓展其应用范围,本文采用小尺度实验的方法,研究了含氯化亚铁添加剂细水雾在不同燃料种类、添加剂浓度、压力下扑灭池火的有效性。实验结果表明：向细水雾中添加氯化亚铁,显著地影响了它的灭火性能;细水雾的灭火时间随着加入的氯化亚铁的质量浓度变化而发生改变,而且存在一个最短灭火时间浓度;细水雾喷头的工作压力和燃料的类型也对细水雾的灭火性能有影响,喷头工作压力越大,细水雾的平均灭火时间越短;在相同的实验条件下,细水雾灭煤油火的时间要短于灭乙醇火的时间。     

Perceptions of Prescribed Burning in a Local Forest Community in Victoria, Australia

The general perceptions of prescribed burning were elicited from forest users for an area that has been subject to this form of land management for at least 20 years. The largest group consisted of local residents living in and around the Wombat State Forest with two smaller groups of students from a nearby university campus and local professional land managers. A questionnaire was given to each participant in order to explore how the forest was used, to determine the level of knowledge of burning in the targeted forest and Victoria and the perception of the appearance, effectiveness of protection, and accessibility to the forest after prescribed burning. Generally all groups had similar responses with community members having stronger views on the effectiveness and practicalities of prescribed burning, whereas students were more neutral in their opinions. All participants claimed knowledge of prescribed burning activities within Victoria, but fewer had experience of planned fires in the Wombat State Forest. All groups agreed that areas that had not been recently burned had a better appearance than those that had, but this result may have included a range of value judgments. Land managers had a greater understanding of the ecological importance of season and timing of burning; however, some students and community members were equally knowledgeable. Prescribed burning did not impede access to the forest, nor did smoke from prescribed burns pose any great problem. The majority of the participants felt that the amount of prescribed burning done in the forest was adequate for engendering a feeling of protection to life and property, yet many were still suspicious of this management practice. These initial findings indicate several areas in which further research would be useful including the efficacy of education programs for community members and improved communication of burn plans by land managers.     

无消防水池的变电站火灾工况数值模拟研究

当前,建于市区的变电站为了节约用地,其消防系统通常不建设消防水池,消防用水直接从市政管网取水,该消防模式下的取水安全及管网响应情况值得关注.论文以某城市中心城区为例,采用EPANET 2.0构建了供水管网模型,针对供水高峰、流量转输和事故爆管3种不利供水条件,开展了无消防水池变电站的消防系统5种不同火灾工况的水力计算与...     

石油液化气储配站火灾爆炸危险分析与事故后果评价

对石油液化气储配站火灾爆炸危险因素从危险物质、设计与施工、安全管理等方面进行分析,并进行了重大危险源辨识,对石油液化气泄漏引发蒸气云爆炸事故进行后果评价,并提出了相应的安全对策.     

液化石油气事故机理及模拟评价方法

液化石油气的生产、储运过程中蒸气爆炸事故屡有发生,并导致其他类型的爆炸.结合液化石油气的典型案例,对液化石油气火灾爆炸事故发生的过程、机理和评价模型进行了研究与分析.     

铁路油罐车充装过程火灾爆炸危险性分析

铁路油罐车在成品油充装过程中,由于油品本身的易燃易爆特性以及静电等危险因素的作用,极易发生火灾爆炸事故. 通过对静电等危险因素产生的过程及原因进行分析,阐述了在充装工艺过程中,防止静电等危险有害因素产生的控制方法,并提出了在铁路油罐车成品油充装过程中,防止火灾爆炸事故发生的技术对策措施.     

对现行民用建筑防火技术体系的分析与探讨

以"处方式"为主要特征的《建筑设计防火规范》、《高层民用建筑设计防火规范》等技术规范构成了我国现行民用建筑防火技术体系,其分类标准和技术体系尚需细化,诸多防火设计与建筑功能设计的矛盾仍无法得到有效解决.由于专家论证、性能化防火设计等途径尚未完善,因此细化建筑分类标准,完善防火技术手段,加快规范体系更新,仍是促进民用建筑防火技术体系不断完善成熟的有效途径.     

大型油罐火灾爆炸危害范围研究

针对大型油罐火灾爆炸对人员伤亡危害范围的问题,采用PHAST软件模拟定量分析了外部环境（风速、大气稳定度、空气湿度）、初始条件（泄漏点离地高度、泄漏孔直径）和其他因素（防火堤面积）对火灾爆炸伤亡半径的影响,根据模拟结果拟合了外部环境和初始条件与池火灾和蒸气云爆炸危害范围的关系式。结果表明:在相同条件下,软件模拟与实验结果误差较小,该研究具有可信性;池火灾危害范围随风速、泄漏点离地高度、泄漏孔当量直径和防火堤面积的增加而增加,而与大气稳定度的关系不大;蒸气云爆炸危害范围随风速的增加而降低,随大气稳定度和泄漏孔当量直径的增加而增加,而与泄漏点离地高度和空气湿度影响不大;拟合得到的外部环境和初始条件与池火灾和蒸气云爆炸危害范围的关系式可为大型油罐火灾爆炸事故中相关作业人员的应急撤离提供决策参考。     

高层建筑电气火灾隐患因子定量分析方法研究

为了对高层建筑电气火灾隐患排查进行定量化分析,采用解释结构模型构建高层建筑电气火灾隐患因子的复杂逻辑模型;在利用德尔菲法确定隐患因子初始概率的基础上,经过交叉影响分析法求解交叉影响概率矩阵;引入马尔科夫链修正各隐患因子交叉影响后的概率,得到火灾隐患因子的稳态概率矩阵。研究结果表明:各隐患因子的马尔科夫链校正概率比德尔菲法测定的初始概率更加准确,该计算排序结果可明确高层电气火灾隐患排查和管控的重点。