毒气泄漏威胁下建筑气密性对就地避难效果影响研究*

针对我国毒气泄漏生产安全事故中就地避难策略的选择缺乏依据的问题，基于毒气扩散理论、建筑气密性分级模型及毒物浓度伤害准则，评析位于毒气泄漏源不同距离处不同气密性建筑作为“就地避难场所”的可靠性与有效性。结果表明:事故中，室外毒气浓度短时间内达到峰值后迅速回落，而室内毒气浓度达到峰值后回落缓慢；室内毒气浓度达到峰值所需时间受气密性影响小，但其降速随气密性等级的增大而明显放缓。最后，研究提出距泄漏源不同距离处就地避难建筑应达到的气密性水平。     

考虑人员疏散无序性的片区固定避难空间仿真及优化

为优化震后城市老旧片区中长期避难疏散阶段避难效率和资源分布，考虑避难场所服务覆盖交叉区域内人员疏散的无序性，以某城市典型老城片区为研究对象，基于震后人员远程疏散特性及中长期避难需求建立固定避难场所吸引度体系，并通过NetLogo多智能体动态仿真模型进行对比分析。结果表明，当避难场所服务半径为0.8 km、1.0 km和1.2 km时，片区内人员均可在49 min内完成疏散，满足规范中对于固定避难1 h内疏散时长的要求，疏散效率较优。基于优化的服务半径和人员疏散需求，对避难场所场地风险、有效面积、避难设施进一步量性优化，为片区固定避难场所合理规划提供理论依据。     

矿井避难硐室供氧系统研究

在矿山井下事故发生后的矿工自救中,设置避难硐室是十分必要的.供氧系统是避难硐室内避难人员生存的重要保障,避难硐室具有容载人数多、空间相对较大的特点.针对国内避难硐室采用的地面钻孔供氧、压风供氧、压缩气瓶供氧、化学氧供氧等供氧方式进行了研究,分别通过基本供风量、供氧量等参数的理论计算方法,密闭空间模拟试验的方法来对几种供氧方式进行比较,最终确定避难硐室设置多种供氧方式的必要性,为今后避难硐室供氧系统的构建奠定基础.     

避难硐室气体防毒安全性研究

为研究灾变时期井下避难硐室进出口有毒气体CO入侵弥散问题,基于等效原理,利用Gambit软件建立地面钻孔正压通风避难硐室物理模型和开门状态下有毒气体进入避难硐室的流体力学原理及气体弥散数学模型,并利用Fluent软件模拟钻孔压风量与室内CO浓度变化关系,提出在避难硐室的隔离门前加装门衬的办法,使避难人员穿过避难硐室门时...     

旬东煤矿井下永久避难硐室构建研究

避难硐室的构建研究对硐室安全避险功能的实现具有重要意义。根据旬东井下人员分布及巷道布置情况,确定利用4-2采煤区现有巷道构建100人规模永久避难硐室;根据巷道尺寸、人均面积及设备体积等,计算得硐室有效宽度为4.6m,高度为3.5m,总长度为63.4m,人均面积为1.2m2;通过气密试验,测定0.135MPa避险区内外压差可达1980Pa;通过分析人员避险需求,确定旬东永久避难硐室生命保障系统由防火防爆系统、密闭缓冲系统、气幕隔绝系统、供氧系统、制冷除湿系统及附属系统组成。     

矿井避难硐室正压密闭系统研究

矿井避难硐室在灾变时为矿工提供了隔绝密闭的避难空间,内部正压密闭系统起到了隔绝有毒有害气体的作用。本文对矿井避难硐室正压系统进行研究,确定影响矿井避难硐室正压数值的因素,通过理论计算确定了矿井避难硐室正压值,同时确定了矿井避难硐室的正压维持方式并设计了相应的余压阀。为保证矿井避难硐室正压的实现,对矿井避难硐室密闭系统进行研究,包括建筑密闭和设施密闭。     

避难硐室压风供氧系统压风量研究

分析避难硐室内人员生存环境主要参数变化情况,研究其压风供氧系统人均所需压风量。根据硐室内压风与人员呼吸CO2间关系,绘制硐室内空气中CO2体积分数随时间变化曲线,得出CO2体积分数稳定值与压风量的关系。通过分析CO2稀释方程、热量平衡、湿度平衡和O2平衡,确定人均压风量为100 L/min。在常村煤矿避难硐室进行80人16 h压风供氧生存试验,结果表明:压风量100 L/min能够满足硐室内人员呼吸需要,硐室内各环境参数均在国家标准要求范围内,温度的迅速稳定表明硐室周围岩体的导热性良好。     

基于多目标规划的城市避难场所选址研究

当城市发生重大事故灾害与突发事件时,有效地对人群进行疏散,使之撤离到相对安全的避难场所,是应急救援行动的核心技术问题,是解决城市公共安全问题必须首先面对的重大课题.充分考虑选址问题中的"公平"和"效率"原则,提出了城市避难场所选址的多目标规划模型,并利用建模优化软件LINGO(Linear Interactive and General Optimizer)进行了求解,从而得出避难场所的最佳选址位置.最后,以天津市地震避难场所的选址为例,说明了多目标规划在城市避难场所选址中的应用过程.结果表明,这种方法可以满足选址规划需求,具有一定的现实意义.     

避难场所适宜性评价及服务范围空间相关性分析

为使应急避难场所空间布局合理，提升避难转移安置的效率，以武昌区内35个潜在避难场所为研究对象，从适宜性和服务范围双重角度探究避难场所空间分布的合理性。首先，从公众角度出发选择适宜性评价指标，然后运用熵权法与逼近理想解排序法(Technique for Order Preference by Similarity to an Ideal Solution, TOPSIS)相结合的方法得到评价结果，最后采用双变量Moran’s I进行避难场所适宜性评价与服务范围的空间关联分析，得到两者耦合空间分布特征。结果表明：目前武昌区避难场所适宜性与服务范围整体呈正相关关系且存在空间集聚现象，避难场所的适宜性受服务范围影响，但仍有部分避难场所呈负相关关系，这种关系因地而异。除此之外，提高避难场所的适宜性不能局限于增加有效面积，需要综合考虑多种影响因素。     

工作面火灾CO运移规律及FED模型评价下的疏散参数研究

矿井工作面进风巷火灾对作业人员的逃生影响极大,有毒烟气尤其是CO是造成人员中毒死亡事故的主要原因。以山东某矿3302工作面为例,采用FDS软件研究不同风速下的CO运移规律,通过FED模型确定CO体积分数、人员接触时间综合影响下的安全疏散参数。结果表明:10 MW火灾规模下,工作面进风巷火灾稳定发展阶段,回风巷人眼特征高度处的CO体积分数相等,其表征运移速度与风速呈线性关系;可利用安全疏散时间随CO运移速度和人员逃生速度差值的增大而减小;在临界风速2.0 m/s时,极限可利用安全疏散时间最短。最后提出了合理设定避难硐室区域范围的计算方法,可为工作面火灾时期的人员安全逃生及避难硐室设定提供参考。     

Shelter-in-place risk assessment for high-pressure natural gas wells with hydrogen sulphide and its application in emergency management

This paper provides a risk assessment method of sheltering in-place for high-pressure natural gas wells with hydrogen sulphide. In this paper, the shelter-in-place risk is estimated by integrating the health consequences of an individual taking one kind of emergency response to the emergency orders of sheltering in place from the emergency decision makers and the probability of the corresponding emergency response action. The probability of the corresponding emergency response action in the proposed method is estimated through the accident probability analysis and the probability analysis of taking a certain response action. The health consequence estimation is based on air exchange rate test of the shelter buildings as well as accident consequence calculation. The evaluation of shelter-in-place risks based on “as low as reasonably practicable (ALARP)” guidelines was employed to provide suggestions for emergency management under both normal conditions and off normal conditions. A case study of risk assessment of sheltering in the local residential houses in Xuanhan County of Sichuan Province, China was taken as an example to illustrate the proposed risk assessment process of shelter-in-place and its application in the decision-making process for emergency management.     

有毒化学品泄漏事故应急防护行动决策探讨

当发生有毒化学品泄漏事故时,为保护公众和工人的安全和健康,需要快速地选择合适的应急防护行动.通常采用的应急防护行动有疏散、隐蔽、使用个人防护装备和服用解毒剂等.决策者必须权衡大量影响因素间的相互作用,如化学品的释放特征、事故现场的气象条件及影响范围内的人群分布等来进行应急防护行动决策.本文在分析应急防护行动决策过程关键要素的基础上,详细总结了影响应急防护行动决策的因素,介绍了应急决策常用的方法,以便在有毒化学品泄漏事故的应急过程中有效决策,最大限度地减少人员伤亡.     

地铁单面坡隧道列车火灾通风模式研究

针对地铁单面坡隧道连续下坡距离长、提升高度大的特点,以国内某城市地铁线路为研究对象,构建列车火灾通风排烟数值计算模型,并采用1:20模型实验对数值计算精确度进行验证,通过考虑列车起火位置、风机开启模式和隧道断面形式等因素,对火灾烟气扩散过程、疏散平台上方烟气温度和气体浓度进行分析。研究结果表明:列车起火后,单洞单线隧道2端车站应各开启2台隧道风机,单洞双线隧道除开启射流风机外,2端车站应各开启4台隧道风机执行相应的排烟和送风模式进行烟气控制;由于单洞双线隧道中热损失和空气卷吸量较大,火灾烟气温度、CO和CO2浓度均低于单洞单线隧道;采用纵向通风控制烟气逆流的同时,下风向区域的烟气沉降作用较为明显,防排烟设计中应充分考虑列车中部火灾下风向车厢区域的危险性,合理确定应急响应模式。     

Kinetics characteristics of coal low-temperature oxidation in oxygen-depleted air

The longwall gob (mined-out) area is one of the main places that are prone to coal spontaneous combustion and most of the residual coal in it is in oxygen-depleted air as it is a semi-enclosed space. A DSC (Differential scanning calorimetry) test system was designed to accurately test the heat generation of coal oxidation in different oxygen concentration atmosphere, based on which the kinetics parameters (activation energy and pre-exponential factor) of coal low-temperature oxidation in oxygen-depleted air were solved out. The results show that the kinetics parameters present obvious stage features and the lower the oxygen concentration is, the smaller is the difference of the kinetics parameters that in different oxidation stages. When the oxygen concentration is lower than 5% and 3% for jet coal and meagre coal respectively, the kinetics parameters of slow oxidation start to be greater than that of rapid oxidation. Both in the slow oxidation and rapid oxidation stage, with the decrease of oxygen concentration, kinetics parameters present significant decline on the whole while in different oxygen concentration range, the decline rate is different. It's concluded that when assessing the residual coal's self-heating risk, we need to use the corresponding kinetics parameters of coal oxidation in the oxygen concentration of the location where the residual coal is and the safety factor will be greater to only use the kinetics parameters of coal oxidation in slow oxidation stage. This study is of great significance for the assessment and control of the self-heating risk of coal that in different oxygen concentration atmospheres of the longwall gob areas.     

Using consequence – based hazard zone assessment for effective evacuation planning of vulnerable settlements along hazmat transport corridors through industrial city of Surat in western India

Following a toxic hazmat release, decisions need to be made vis-a-vis a safe evacuation distance for population along the transportation route, or whether to shelter-in-place if there is insufficient time to conduct an evacuation. The first responder may have to take these decisions through a quick estimation of the Initial Isolation Zone (IIZ) and protective action distances based on assumed rate of releases. Real-time evacuation planning models could be used for effective evacuation purposes. However, factors that usually were taken into account include weather conditions, population density, time of day, and uncertainty about the chemicals involved and/or the accumulating concentrations in public areas. Emergency planning including evacuation in India is generally in line with UNEP's APELL (Awareness and Preparedness for Emergencies at Local Level) methodology. However, quantitative risk based assessment is catching up particularly in large industrial zones. The paper highlights a case study of the evaluation of identified seven critical evacuation planning zones along three highway study routes in and around the industrial city of Surat in western India. The elapsed time after a release is estimated through ALOHA and evacuation travel time estimates are made for each zone. For identified scenarios, evacuation of IIZ, generally comprising of road side population, is effectively possible in six out of seven identified emergency planning zones except in zone-7, where certain people would still be exposed, as full evacuation may not be achieved. However, shelter-in-place would be advisable for population residing in permanent settlements within the protective action zone.     

基于动态毒性负荷的人员疏散安全评估方法

毒气泄漏事故在高含硫气田及化工园区频繁发生,一旦发生事故,周边公众迅速进行疏散是应急的首要任务。我国很多地区制定了疏散方案,但是如何评估疏散的安全性和可行性,是亟待解决的问题。分析了我国泄漏事故特点和周边居民情况,对以往评估方法缺陷进行了剖析,提出基于动态毒性负荷分析的安全疏散评估方法。该方法在毒气扩散的精确3d模拟及疏散模拟的基础上,用差分法对人员行走过程中的毒性负荷Pc进行的计算,最终得出相应的致死概率Pr,并通过一个实例验证该方法的可行性。结果表明,运用该方法能够详尽、准确规划疏散区域、搬迁区域和避难区域。     

紧急避险设施内一氧化碳气体吸附性能研究

紧急避险设施作为灾变情况下为井下人员提供安全避险的密闭空间,要求能够对空间内部的有毒有害气体进行及时处理。针对井下密闭空间内部一氧化碳气体的吸附处理问题,采用北京科技大学避险技术研究中心的地面模拟救生舱作为实验平台,以实验为基本手段,对两种药剂A、B在不同药剂量、风量的情况下进行去除效率的对比实验,并测定环境湿度对药剂性能的影响,确定一氧化碳药剂的最佳吸附条件,以达到提高去除效率的目的。最终得出药剂A以全风量条件下4kg时吸附效果为最佳,药剂B以全风量条件下8kg时吸附效果为最佳,湿度对一氧化碳药剂的吸附效率有显著影响,需配合干燥剂使用。     

A dynamic approach for evaluating the consequences of toxic gas dispersion in the chemical plants using CFD and evacuation modelling

Accidental releases of toxic gas in the chemical plants have caused significant harm to the exposed occupants. To evaluate the consequences of these accidents, a dynamic approach considering the gas dispersion and behavior evacuation modelling has been proposed in this paper. This approach is applied to a hypothetical scenario including an accidental chlorine release in a chemical plant. CFD technique is utilized to calculate the time-varying concentration filed and evacuation modelling is used to obtain the evacuation routes. The exposure concentrations in the evacuation routes are calculated by using the code of data query. The integrated concentration toxic load model and probit model are used to calculate the probability of mortality of each occupant by using the exposure concentrations. Based on this dynamic approach, a new concept of average probability of mortality (APM) has been proposed to quantify the consequences of different accidental scenarios. The results show that APM decreases when the required detection time decreases or emergency evacuation mode is implemented. The impact of the detection time on APM becomes small as the wind speed increases. The effect of emergency evacuation mode is more obvious when the release occurs in an outdoor space.     

上、下悬窗阻风能力对比研究

环境风会改变排烟窗附近的烟气流向和速度,影响建筑内烟气流动,进而导致建筑自然排烟效率受到影响。采用数值模拟方法,对比研究了排烟窗开启角度和环境风对上、下悬窗阻风能力的影响,分析了不同开窗角度下,悬窗进风量和进风区域随开窗角度和风速的变化规律。结果表明:上、下悬窗相对进风量与开窗角度均成指数关系,但上悬窗阻风能力弱于下悬窗,上悬窗开窗角度大于45°后即失去阻风能力,而下悬窗开窗角度大于75°后才逐渐失去阻风能力,且开窗角度小于30°时,下悬窗至少能比上悬窗多减少50%空气进入室内。上悬窗开窗角度小于56°时,主要进风区域为近窗下侧水平区域;下悬窗开窗角度小于30°时,主要进风区域为窗体两侧及远窗下侧竖直区域,随着开窗角度增大,上、下悬窗主要进风区域均过渡到远窗下侧竖直区域。窗体用于日常通风时建议优选上悬窗。若要用于排烟,则应首选下悬窗,开窗角度15°即可满足阻风要求,若选用上悬窗,开窗角度不宜大于45°。