地铁站台火灾不同排烟模式对人员疏散的影响

为研究火灾场景下不同排烟模式对人员疏散的影响,以某双层岛式地铁车站为原型,通过FDS软件建立火灾模型,分析4种排烟模式下地铁站台的火灾烟气温度、CO体积分数、能见度的分布。规定疏散时间360 s内,在人眼特征高度1.6 m处：自然排烟模式下的人员疏散途径区域出现温度大于60 ℃、CO体积分数大于250×10^-6、能见度低于10 m的区域;车站隧道排烟模式下的人员疏散途径区域出现能见度低于10 m的区域;车站公共区排烟模式和车站公共区及车站隧道混合排烟模式下,人员疏散途径区域火灾烟气温度、CO体积分数、能见度均低于疏散指标。     

不同隧道排烟模式对站台火灾人员疏散的影响

为探究站台火灾条件下不同隧道排烟模式对地铁人员疏散的影响,以岛式地铁站为研究对象,利用Pyrosim建立火灾模型,并分析4种隧道排烟模式下的楼扶梯入口风速、烟气温度、CO体积分数和能见度的分布。结果表明：单一隧道排烟模式均无法满足安全疏散要求;疏散时间360 s内,在人眼特征高度处,车站隧道排烟模式下的人员疏散经过区域的能见度不能满足疏散要求,CO体积分数、温度、楼扶梯口风速均满足安全疏散要求;3种区间隧道排烟模式下的楼扶梯口风速均无法满足人员安全疏散要求,区间隧道推拉式反向排烟模式最不利于疏散区域烟气散热,区间隧道双拉式排烟模式排烟效果最为显著;火灾烟气的3个潜在危险因素中,相比于温度和CO体积分数,满足能见度在安全范围内的难度更高。     

城际铁路地下站超大站厅防火分隔方案研究

针对某城际铁路地下换乘站站厅1.2×104 m2 的超大防火分区,为确定合理有效的防火分隔方案,采用预先危险性的分析方法对站厅火灾风险进行了辨识,提出了“防火卷帘”“挡烟垂帘”“防火隔离带”3 种基于建筑消防安全性能的防火分隔方案。从合规性、人员安全疏散、火灾蔓延和烟气控制等方面对各方案进行定性分析,并总结优缺点。采用FDS 和Pathfinder 分别构建火灾烟气和人员疏散模型对各方案的消防安全性进行验证,结果表明3 种防火分隔方案均能满足人员的安全疏散。     

Effectiveness of downward evacuation in a large-scale subway fire using Fire Dynamics Simulator

Effective evacuation routes in the case of a large-scale subway fire were studied. A serious problem in the subway fire is that the directions of smoke flow are coincident with those of evacuation toward the surface. Hence, it is necessary to design an evacuation route without interference from smoke. A disastrous fire broke out in the Jungangno subway station in Daegu, South Korea in 2003. Based on this case, the Jungangno subway station with three basement levels was used in Fire Dynamics Simulator model in this study. The influences of smoke, temperature, and toxic gases (carbon monoxide [CO] and carbon dioxide [CO₂]) were computed at the evacuation staircases in the subway station with a fire source in the third basement floor (B3). The calculations showed that the evacuation staircases had high smoke density, temperature, and concentrations of CO and CO₂ in the subway fire. Hence, these factors greatly affected all of the upward evacuation staircases due to the coincidence of the smoke flow and the evacuation routes. Therefore, our paper proposes a new subway station with a fourth basement floor (B4) having downward evacuation routes which are in the opposite direction to the smoke flow. The results of analysis show that these factors hardly affected the staircases from B3 to B4. We conclude that downward evacuation can be more effective than upward evacuation for a large-scale subway fire.     

CFD simulation and assessment of life safety in a subway train fire

Fire is a major risk in the event of subway train fire due to coincidence with direction of smoke flow and evacuation. As a part of an effort to improve the life safety in a train fire, the platform screen door (PSD) is more and more installed on the ground that PSD provides a lot of benefits to passenger’s safety. Therefore, the investigation of effect of PSD on life safety is needed. In this study, fire simulation and evacuation simulation are performed to estimate the effect of PSD and ventilation on passenger’s life safety in a subway train fire. The Fire Dynamics Simulator (FDS V406) code is used to predict smoke spread and the available safe egress time during the fire. The evacuation of a subway station due to a train fire is simulated to predict the time required for evacuation, obtaining travel speed as a function of density. The passengers in platform with PSD and ventilation system have much more available time of about 350 s than passengers in case without PSD and ventilation system in modeled subway station. The subway turnstiles (ticket gate) dramatically increase the time required for evacuation without moving toward exits and bring passenger’s life safety danger in a subway train fire.     

防排烟系统对拱形地铁站厅烟气蔓延的影响

地铁站厅防排烟系统对人员安全疏散具有致关重要的作用。通过烟气层沉降理论分析,编写了适用于拱形地铁站厅火灾烟气蔓延区域模型程序,研究不同机械排烟量下烟气沉降高度随时间的变化规律。研究表明,随着排烟量的增加,烟气层沉降速度变慢,排烟量为28.4 m³/s时,360 s左右烟气层方才达到溢出口高度,该设计排烟量能满足人员安全疏散要求。通过火灾动力学软件FDS数值模拟的方法,研究不同排烟量和挡烟垂壁高度对地铁站厅能见度、CO浓度的影响。研究表明,烟气从高大站厅空间向狭小的通道空间溢出,容易在通道出口处形成烟气堆积,导致通道出口处能见度最低,CO浓度最高;验证了烟气层沉降理论计算地铁站厅烟气排烟量可以满足人员安全疏散的要求;设置挡烟垂壁可以提高地铁站厅的能见度和降低其CO浓度。     

The Impact of a Change on the Size of the Smoke Compartment in the Evacuation of Health Care Facilities

Evacuation in health-care facilities is complex due to the physical impairment of the patients. This kind of evacuation usually requires the assistance of the workforce members. A proposed change of NFPA 101, Life Safety Code, would increase the maximum allowable size of a smoke compartment (a space within the building enclosed by smoke barriers on all sides that restricts the movement of smoke) in health-care occupancies from 2090 m² to 3700 m², almost double the size. This study aims to analyse the impact of this change in the required time for evacuating patients during a fire in order to understand the consequences of that potential change. This paper is focused on the area where the patient’s rooms are located. The evacuation scenario is a floor plan comprised of four smoke compartments. To analyse the proposed change, the smoke barriers between two adjacent compartments were removed in a floor plan and three ratios of number of patients per one staff member were considered (4:1, 3:1 and 2:1). A computational methodology was conducted to calibrate the model STEPS for simulating assisted evacuation processes. In addition, Fire Dynamic Simulator (FDS) was used to simulate the fire and smoke spread in a table and a PC to compare fire and evacuation results The evacuation results show that the change of the smoke compartment size increases the mean evacuation time by 23%; however, the fire results show that the available safe egress time is 16 min for both smaller and large smoke compartment. The ratio of the number of patients per staff member is also a strong factor that increases the evacuation up to 82% when comparing the ratios of 2 patients per staff member and 4 patients per staff member.     

着火列车制动进站过程烟气扩散特性模拟

为探究火灾列车制动驶向地下车站进行救援时的烟气扩散特性，采用理论分析和数值模拟的方法研究在不同控制烟气措施下，火灾列车减速至停止过程中烟气在车站轨行区及站台层的扩散规律，以及车站防灾通风系统受到的影响。结果表明：火灾列车制动进站时受移动火源与活塞风两大特性影响，烟气在上下游表现出明显的不均匀、不对称分布规律；屏蔽门虽能有效阻止烟气蔓延至站台层，但同时会增大轨行区活塞风速，增加烟气蔓延速度，不利于安全疏散；受活塞风影响，轨行区排烟效率下降了14%，轨行区各排烟阀火灾中下游排烟效率更高。     

城市水下公路隧道火灾时人员安全疏散

以长沙市某水下公路隧道为研究对象,介绍隧道火灾时人员安全疏散准则及影响因素.设定火灾场景和疏散场景,分别利用FDS 5.3.0和EVACNET4模拟各火灾场景下的烟气蔓延及人员疏散,得到各种火灾场景下隧道内的可用安全疏散时间曲线和必需安全疏散时间曲线,分析不同火灾场景下人员疏散的安全性.在消防设施正常工作的情况下隧道内人员能够安全疏散,应加强消防设施的日常维护.     

Assessment of ventilation efficiency for emergency situations in subway systems by CFD modeling

The ventilation system is the strategic component of the subway systems when incidents involving heavy smoke occur in tunnels. Consequently, the purpose of this study is to investigate the ventilation efficiency in one of the most severe emergency scenario: train on fire (maximum heat release rate reaching 30 MW due to an ultra-fast fire) and stopped in the tunnel, the incident requiring passenger evacuation. Two ventilation strategies are taken into account: tunnel ventilation fan system (mid-tunnel fan plant located in separate construction) in conjunction with stations mechanical ventilation and end-of-station fan plants in conjunction with stations mechanical ventilation. The analysis is performed using computational fluid dynamics (CFD) modeling. The numerical model proposes an original approach based on the introduction of source terms in conservation equations for energy, carbon monoxide (CO) and carbon dioxide (CO₂), in order to deal with the heat, CO, and CO₂ due to fire. Equations expressing the conservation of CO and CO₂ are specially added to the basic equations governing a turbulent non-isothermal airflow in the CFD model. This method allowed achieving values of velocity, temperature, CO and CO₂ concentrations all over the computational domain. In addition, the modeling and simulation methodology complies faithfully to the real operation of the ventilation systems investigated in normal and emergency (fire) conditions. The results show that both ventilation alternatives taken into account lead to the secure evacuation of passengers all over the simulation time. The evacuation process toward the nearest station is not at all disturbed by too high air velocities, high temperatures or critical CO or CO₂ concentrations.     

基于软件SMARTFIRE下的火灾模拟研究

介绍了火灾模拟软件SMARTFIRE的各个组成部分，就其实现模拟的具体步骤进行了阐述，并针时国内某地铁线路的典型双层岛式站台建立了模型，时某车厢着火的情况进行了数值模拟，获得了该火源状况下站台及着火车厢的烟气和温度场分布。希望能通过将来更深入的应用，为消防部队和有关部门提供火灾预测，为灭火救援的方案制定提供技术依据。     

地铁车站的火灾烟气控制设计

分析大型地铁车站空间、功能特点,从火灾荷载、人员密度、烟气蔓延特性、防排烟系统设计难度等方面入手,以某大型地铁站为例,利用实地烟热试验对站厅层和站台层的防排烟设计进行了研究,分析了试验项目、评价指标和测量指标。结果表明,对于复杂的地铁车站,通过优化灭火设施和防排烟系统,科学合理划分防烟分区,对重点区域进行防火分隔,严格控制地铁车站公共区域可燃物量,可有效控制火灾和烟气的发展蔓延,确保人员安全疏散的时间要求。     

基于BIM与Revit的地下建筑火灾预警及疏散系统

为预防地铁等地下建筑火灾事故,将BIM与Revit技术应用于地下建筑火灾预警和疏散管理中,分析不同条件下烟雾、人员疏散过程变化,实现对地铁火灾的预警和疏散可视化平台建设。以某运营地铁站为例,根据火灾烟气扩散过程确定烟气高度作为评价疏散安全性的指标,获得临界烟气最小高度下的可用疏散时间;通过人员量化处理进行人员疏散模拟,获得必需疏散时间并与可用疏散时间对比,进行建筑模型的评价和优化,以满足安全使用要求。结果表明：现有疏散通道布局存在一定安全隐患,可通过撤除不合理商业箱、提高候车公共区空地面积、增加喷淋设备密度、组织安全疏散演练等方式降低疏散时间,降低安全隐患。     

火灾能见度对地铁人员疏散速度影响的仿真研究

基于火灾动力学理论与大型换乘地铁站火灾特点,利用FDS软件（郑州大学超算中心6.7.5版本）对郑州紫荆山地铁站进行火灾数值模拟,通过布置在地铁站台层、站厅层、转换层各个区域以及所有楼扶梯处的火灾探测点,分析火源位于地下四层的二号线站台层时能见度随时间的变化情况。根据能见度与速度的折减公式,计算不同时间节点的速度折减系数。然后在Pathfinder（2020版本）车站疏散模型各区域中导入人群疏散速度折减系数,并与速度未折减时的情况进行对比分析,得到更加精确的疏散人员动态速度。结果发现在靠近火源位置且跨度为两层的楼扶梯上更容易发生人员滞留。     

重庆市发展长江水源热泵的水源概况分析

为了解重庆段长江水作为热泵冷热源的概况,对重庆段长江水温的横断面变化和时间变化进行了实测分析,并对江水的水质和水位变化进行了分析,得到长江水温在整个横断面基本恒定,而江水的夏季月平均温度在22~25℃,冬季月平均温度在11~16℃,水温日变化幅度不超过0.5℃。是一种具有良好品质的稳定的冷热源。而长江水作为水源热泵的冷热源,主要解决的水质问题是泥沙和悬浮物,在三峡库区形成后水位变化可达到30 m,因此取水方式可考虑采用浮船取水方式。     

大中庭地铁车站的防火系统分析

对大中庭地铁车站进行了定义和分类。介绍了上海地铁7号线花木路站防火系统设计,提出了与常规地铁车站不同的新型防排烟系统。采用性能化防火设计分析的方法,对大中庭车站的防火排烟系统、人员疏散设施等防火系统进行了模拟计算与分析。结果表明,通过在站厅顶部设置大中庭专用排烟控烟管道,在发生火灾时,可有效控制烟气扩散,为人员疏散提供"可接受的维生环境"。     

某商业综合体防火设计难点分析

针对该商业综合体的建筑特点、商业布局,本文主要提出了将步行街两侧的商铺与步行街公共区域采用防火分隔设施分开的建议。在此基础上从防火分隔、防烟排烟系统、自动灭火系统、人员疏散等方面提出了消防设计建议方案。此外,还针对影院提出了相关措施,保障其内部人员安全疏散。根据建筑的火灾危险性设定合理的火灾场景及相应的人员疏散场景,通过数值模拟计算,分析研究火灾及烟气的蔓延特性和人员疏散特性,论证本文提出的消防设计方案是能达到所设定的消防安全目标。     

A Model for Simulating Human Behavior During Emergency Evacuation Based on Classificatory Reasoning and Certainty Value Handling

Abstract: A computational model that simulates human behavior under fire and earthquake emergencies has been developed, using the object-oriented language Smalltalk-80. The present model consists of a space model, a scenario model and a human model. In the space model, the spaces in which people can move are represented by nodes connected by links. The nodes incorporate exit, guidelight and staircase facility data. Also, they feature environmental data including the darkness of the lighting system and the density of smoke. Seismic hazards such as a power failure and occurrence and expansion of fire and smoke are represented in the scenario model. This kind of information is then furnished from the scenario model to the space model as obstruction information. In the human model, a suitable knowledge-based model has been constructed for representing evacuation behavior: people choose the evacuation path based on the production rules with certainty values, and move to the target exit along the evacuation links. The present simulation model is experimentally applied to examine the behavior which masses of people take in an underground structure under an emergency condition caused by an earthquake, and the results obtained confirm that the model is able to simulate correctly the principal human behavior enacted in an emergency evacuation.     

双层地铁车站防排烟的数值模拟研究

运用区域模型模拟车站内不同防排烟工况下烟气温度、高度、CO体积分数随时间的变化规律,以三项危险临界条件是否实现作为衡量防排烟效果的判据.模拟结果表明,只有同时对站台楼梯送风防烟和对火源所在防烟分区及时排烟,才能在车站内实现最有利于人员疏散的安全环境.     

地铁站厅至站台楼梯口风速对火灾烟气运动的影响

地铁车站站台发生火灾,连接站厅与站台的楼梯口保持一定风速,可阻挡烟气向站厅蔓延并为人员疏散提供诱导气流。为研究楼梯口风速对车站火灾烟气运动的影响,试验对不同排烟模式下楼梯口风速进行测量,建立数值计算模型进行模拟。结果表明：火灾场景下楼梯口风速大于无火源场景下风速,因此常规楼梯口风速校核设计方法由于没考虑真实火灾情况下各种因素的复杂作用,需进一步改进;楼梯口附近起火,烟气易从挡烟垂壁溢出向站厅层蔓延,站台火灾时站厅层为送风状态,存在溢出烟气时站厅层烟浓度可增至大于站台层;站台公共区着火,增开隧道风机,能够增