Experimental study and numerical simulation for a storehouse fire accident

Full-scale experiment and numerical simulations are carried out on a shelf fire in a storehouse to study the ignition manner, the fire spread and the combustion characteristics. A computational fluid dynamics (CFD) model of fire-driven fluid flow, FDS (Fire Dynamics Simulator), is used to solve numerically a form of the Navier–Stokes equations for fire. Ignition manner experiments with both cigarette ends and lighter are conducted first. Then a full-scale experiment on a shelf fire is performed. The temperatures are measured and the fire growth and spread process is analyzed. A numerical model is used to simulate the experiment; the temperatures, fire growth and heat release rate are studied. In numerical simulations, the grid size resolution is analyzed. The experimental results of temperatures and the fire growth and spread process are compared with the results of numerical simulations. It shows that the numerical results are in good agreement with the experimental results. The chimney effect is also observed in both the experiment and the simulation. These useful data can be helpful in the numerical reconstruction of the whole storehouse fire accident.     

基于OGRE的应急火灾仿真研究及实现

从粒子系统的基本生成步骤、粒子系统在OGRE中的调用方法等方面介绍OGRE粒子系统原理。结合给定火灾案例创建楼房3D实物模型,根据楼体、灾情和环境等实际情况定制着火路线、着火点、燃烧中心等实验数据,通过火灾受力分析、布控着火点、烟的布控等步骤在OGRE中完成了火灾的仿真实验。实验效果证明该仿真方法是可行和有效的。     

基于数值模拟的电动自行车火灾亡人原因分析

为了还原一起电动自行车火灾的发展过程,对其人员伤亡原因进行分析研究。依据案例实际情况利用PyroSim 等软件构建了着火建筑模型,通过设置控制器进行数值模拟,得到了建筑物内火势发展、亡人房间内温度和一氧化碳浓度变化等情况。通过与实际火场照片进行对比,验证了起火点与关键位置的火灾发展情况,同时结合切片情况从温度、一氧化碳浓度和FED三个角度对亡人原因是高温与一氧化碳中毒的共同作用做出了合理的解释,为火灾调查工作提供了依据.     

玻璃痕迹在建筑火灾调查中的作用

在建筑发生重大火灾事故中,很多建筑材料都会在人们对火灾调查取证工作上给予了很大的帮助,玻璃就是其中之一。人们在事故调查毫无头绪下可以发现蛛丝马迹,对火灾事故现场加以分析,进行研究对比,做出正确的判断。     

Experimental and numerical study on water mist suppression system on room fire

Full-scale experiment and numerical simulations are carried out on a room fire to study water mist suppression system with heat release rate of 6 MW. A computational fluid dynamics (CFD) model of fire-driven fluid flow, FDS (Fire Dynamics Simulator), is used to solve numerically a form of the Navier–Stokes equations for fire. A fire experiment without water mist is performed and the temperatures are measured to validate the predictions of FDS code against the experimental data. Then a fire experiment with water mist suppression system is performed and the temperatures and extinguishing time are measured. The validated numerical model is used to simulate the experiment; the temperatures, oxygen concentration and extinguishing time are compared and studied. In numerical simulations, the cell size sensitivity is analyzed. The experimental results of temperatures and extinguishing time are compared with the results of numerical simulations. It appears that the numerical results are in good agreement (qualitatively) with the experimental data in temperature fields. These useful data can be helpful in accomplishing the design of water mist suppression system and the design regulations for fire safety management.     

Fire safety aspects of PCM-enhanced gypsum plasterboards: An experimental and numerical investigation

New trends in building energy efficiency include thermal storage in building elements that can be achieved via the incorporation of Phase Change Materials (PCM). Gypsum plasterboards enhanced with micro-encapsulated paraffin-based PCM have recently become commercially available. This work aims to shed light on the fire safety aspects of using such innovative building materials, by means of an extensive experimental and numerical simulation study. The main thermo-physical properties and the fire behaviour of PCM-enhanced plasterboards are investigated, using a variety of methods (i.e. thermo-gravimetric analysis, differential scanning calorimetry, cone calorimeter, scanning electron microscopy). It is demonstrated that in the high temperature environment developing during a fire, the PCM paraffins evaporate and escape through the failed encapsulation shells and the gypsum plasterboard's porous structure, emerging in the fire region, where they ignite increasing the effective fire load. The experimental data are used to develop a numerical model that accurately describes the fire behaviour of PCM-enhanced gypsum plasterboards. The model is implemented in a Computational Fluid Dynamics (CFD) code and is validated against cone calorimeter test results. CFD simulations are used to demonstrate that the use of paraffin-based PCM-enhanced construction materials may, in case the micro-encapsulation shells fail, adversely affect the fire safety characteristics of a building.     

建筑火灾结构安全数值模拟框架

为了模拟建筑火灾过程中的火灾发展、结构响应及其相互作用提出了该模拟框架。该框架以现有的火灾模拟和结构分析数值模拟软件为基础,通过对其输入文件和模拟结果文件所含信息进行重新建模构成建筑火灾过程的数据环境,根据物理实验研究成果开发了材料高温强度退化和结构破坏方面的数值分析模块,与基础模拟软件一起构成覆盖灾难全过程的数值环境。该框架采用了面向对象的数据建模方法和系统集成技术,使得不同模拟模块的数据对象相互对应并协调工作,并能自动控制各模块实现对火灾过程的模拟,实现了在一个数据环境和一个软件平台上进行建筑火灾结构安全模拟。该框架为建筑火灾研究提供了数值实验方法,具有廉价和快速的特点,也是将实验室研究成果应用于具体建筑仿真的途径,对于建筑火灾性能化设计,消防救援预案的确定和火灾风险评估具有实用价值。     

对流通风条件对起火部位认定的影响

介绍某案例基本情况及现场勘察过程,结合案例剖析对流通风条件下典型火场痕迹特征。依据现场勘验情况进行初步分析,调取第一报警人及现场人员手机视频,结合询问、电气线路勘验、残留物送检等结果,邀请火灾事故调查专家协助调查,认定起火部位。结合案例及火灾调查经历,总结对流通风导致的典型干扰痕迹特征,从5 方面探讨起火部位认定的方法对策。     

The fire environment in a multi-room building— comparison of predicted and experimental results

This paper outlines results from a research project which is being used to investigate realistic fire environments in a prototype multi-room building. A comprehensive set of experimental data was obtained from a recently constructed three-storey Experimental Building-Fire Facility. The facility is used for a variety of fire investigation purposes, including fire growth and spread, smoke movement, and the effects of stair pressurisation and extinguishment. For the current investigation, a propane burner was located in the centre of a burn room to simulate a fire under both steady-state and transient-state conditions. The burn room was connected to other rooms. A comprehensive set of temperature, radiation and flow velocity measurements was obtained.

The numerical results obtained from a computational fluid dynamics (CFD) model were found to agree well with the experimental results. The CFD model results were also found to agree well with zone model predictions. These results encourage use of the CFD model to research the phenomena of realistic fire growth and spread and smoke movement in prototype building layouts.     

浅谈建筑火灾的原因及防范措施

在建筑火灾事故的调查中,发现引发建筑火灾的原因很多,但归纳起来主要由人的不安全行为、电气设备及线路故障、建筑及其消防设施缺陷和自然现象等因素引起的。本文就针对这些建筑火灾的原因,提出相应的防范措施。     

LES field model-based fire accident reconstruction with the OED method and its experimental validation

One of the objectives of fire accident reconstruction is to determine the cause of the fire and to examine the fire spread. The temperature and extent of fire damage are the two most important characteristics in a fire accident. They can be fully utilized in a fire accident simulation that is based on a Large Eddy Simulation (LES) field model, which has been widely used as a simulation model for fire analysis. However, since it needs many simulation runs using this model in fire accident reconstruction, it will increase the reconstruction time and cost. The use of an Orthogonal Experimental Design (OED) method as a tool to reduce the simulation runs in fire accident reconstruction is proposed. An orthogonal array is selected on a discrete design space and levels are chosen from candidate values. Matrix experiments with the orthogonal array are conducted and a range difference analysis is used to find out the optimum levels. The method is applied to a fire experiment as a validation. The numerical and experimental results fit very well.     

Real-Time Forecasting of Building Fire Growth and Smoke Transport via Ensemble Kalman Filter

Forecasting building fire growth and smoke dispersion is a challenging task but can provide early warnings to first responders and building occupants and thus significantly benefit active building fire protection. Although existent computer simulation models may provide acceptable estimations of smoke temperature and quantity, most simulations are still not able to achieve real-time forecast of building fire due to high computational requirements, and/or simulation accuracy subject to users’ inputs. This paper investigates one of the possibilities of using ensemble Kalman filter (EnKF), a statistical method utilizing the real-time sensor data from thermocouple trees in each room, to estimate the spread of an accidental building fire and further forecast smoke dispersion in real time. A general approach to forecasting building fire and smoke is outlined and demonstrated by a 1:5 scaled compartment fire experiment using a 1.0 kW to 2.8 kW propane burner as fire source. The results indicate that the EnKF method is able to forecast smoke transport in a multi-room building fire using 40 ensemble members and provide noticeable accuracy and lead time. Unlike other methods that directly use measurement data as model inputs, the developed model is able to statistically update model parameters to maintain the forecasting accuracy in real time. The results obtained from the model can be potentially applied to assist mechanical smoke removal, emergency evacuation and firefighting.     

一起高层住宅楼亡人火灾事故的调查分析

为分析导致高层居民住宅楼亡人火灾发生的根源性火灾隐患,有效防范火灾发生,减少造成的人员伤亡,通过对一起典型高层住宅楼亡人火灾事故的调查,分别介绍了起火时间、起火部位和起火原因的认定过程,提出了对该起火灾调查的体会,分析了“高层住宅楼小火亡人”频发的灾害成因和火灾事故调查过程中完整证据链条的重要性,从消防宣传、单位主体责任、行业管理责任三方面提出了预防此类火灾发生的建议。     

关于构建火灾事故调查新模式的探讨

火灾事故调查不被重视,专业调查人员少、业务素质水平不高、勘验设备落后、鉴定方法单一等原因,严重制约了火灾事故调查工作的发展,只有构建更加高效、高质的火灾调查模式,提高火灾事故认定的准确性与科学性,才能持续地为经济社会发展和人们安居乐业作出更大的贡献.     

火灾痕迹物证多媒体软件的研制

本文介绍了火灾痕迹物证多媒体软件的研制过程及软件的体系结构和技术性能指标。该软件可为火灾事故调查人员的岗前培训、平时学习和火灾事故调查时对照勘查提供有力的帮助。     

智慧消防物联网系统在火灾调查中的应用

随着社会的发展和人民法制意识的提高，火灾调查的规范性、准确性、科学性受到越来越高的关注。在应用传统技术的火灾事故调查中，因猛烈燃烧、爆炸、烟熏等原因，造成原有建筑物内的设施、物品损毁严重，使火调工作难以开展，工作效率低下，火调结论缺乏科学、准确的数据支撑。智慧消防中的物联网系统可为火灾事故调查提供精准的灾前静态数据和灾中动态数据，为解决上述火调中的技术难题提供了新的思路，为火灾原因认定和火灾延伸调查提供重要的依据。     

中庭火灾模型数值与实验研究

结合火灾相似模型实验对中庭火灾数值模型进行了比较，其中采用的燃烧子模型充分考虑了火源燃烧及蔓延过程对于烟气流动的影响。利用PHOENICS软件开发的应用程序计算表明，大空间建筑火灾数值模拟采用燃烧子模型和辐射换热模型，可以更好地反映出火源释热率的变化情况。计算结果与实验数据比较，定性合理。     

基于GIS 的消防隐患排查薄弱区分析探讨

结合江苏省消防救援总队应用实际,在消防领域综合运用地理信息、数据仓库、搜索引擎、模型算法等技术,结合消防隐患排查数据、火灾数据、单位数据、时空数据等,研究了消防隐患排查与火灾之间的关系与规律,提出多种数据在空间分析算法中的计算方式,并最终构建基于GIS 的消防隐患排查薄弱区分析模型,能够对一定区域的消防监督检查工作提供指导性意见。     

一起越野车起火案例的原因调查

通过对一起汽车火灾事故的调查与取证,根据当事人和发现人提供的信息了解事故的基本状况,如起火时间、起火点、事故和维修情况。根据现场勘验的车辆行驶路线、行驶环境等,对事故车辆燃烧痕迹特征、火灾蔓延发展、发动机舱机械故障的发现、鉴别等多方面信息进行了详细阐述,就此起汽车火灾原因认定的事实和依据作了充分说明,为类似火灾的调查提供参考。     

基于无人机技术的村落建筑群火灾蔓延模型的构建

摘 要：建筑信息匮乏、缺乏图纸是村落建筑群火灾防控面临的首要问题。针对传统的现场测绘工作量大、费用高、获取数据信息不精确等问题,在现场勘察获取典型单体建筑详细建模数据的基础上,采用无人机倾斜摄影技术获取村落建筑群地理信息数据,并建立村落建筑群火灾蔓延分析模型。进一步采用简化分析方法确定建筑群不同建筑起火后的火灾蔓延情况及火灾蔓延损失。最后以云南省某村落为研究对象,建立了该村落的火灾蔓延模型并分析了火灾蔓延风险。结果表明：该方法能有效获取村落建筑群火灾蔓延模型的建模数据,并为后续的火灾蔓延风险分析提供数据支持。