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.     

Sensor Assisted Fire Fighting

Fire detection and monitoring sensors, fire modelling, fire fighting and command and control are usually perceived as independent issues within fire safety. Sensor data is associated to detection and alarm and to some minor extent as a source of very basic information for building management or emergency response. The streams of data emerging from sensors are deemed to lead to a rapid information overload, so the pervasive sensor deployment (now common in modern buildings) is entirely independent of procedures associated to emergency management. Fire modelling follows a similar path because model output is not robust enough, not fast enough and the information generated by such simulations rapidly escalates in quantity and complexity so that no commander can assimilate it. Fire fighting is therefore left as an isolated activity that does not benefit much from sensor data or the potential of modelling the event. This separation is naturally induced by the complexity of a fire event and represents the biggest barrier to the useful development of sensor technology and fire modelling into emergency response. Therefore, current technology applied to fire is decades behind sensor development for other related areas like military operations or intruder security. There is no apparent use for more complex and expensive sensors. This paper describes the different processes that need to be studied to establish a path by which a collection of sensor data can be used to provide early detection, robust building management and adequate information to assist fire fighting operations.     

基于BIM和元胞自动机的建筑#br# 火灾救援路径动态规划研究

建筑物发生火灾时,建筑物复杂的内部环境以及火灾的实时蔓延会给参与室内救援工作的消防员带来隐患甚至生命危险。为提高消防员建筑火灾室内救援效率,文章提出了基于BIM技术和元胞自动机的消防员救援路径动态规划系统。该系统中,创新性将BIM建筑模型与元胞自动机有机结合,建立了一种新型元胞自动机路径规划智慧模型,该模型利用场景分层和碰撞检测的方法自动识别建筑物的各种构件和内部环境,具有很高的智能性和普适性;在火场中添加动态障碍物模型和随机灾变火模型,并利用实时检测方法研究真实火场的动态性对消防员救援路径的实时影响,使消防员科学、高效地避开静态、动态障碍物并安全完成救援。使用该系统对一座单层大空间体育馆进行实例模拟,验证了该系统的适用性,为制定建筑火灾消防救援策略、实现高效精准救援以及智慧消防提供技术支持。     

A Framework for Risk-Informed Performance-Based Fire Protection Design for the Built Environment

Performance-based fire protection design (PBFPD) approaches have now been in use for more than 20 years. One might be tempted to conclude that the current ‘state of the art’ is working well. However, application of PBFPD remains limited, several shortcomings exist, and an increasing number of countries are moving toward ‘prescribed performance’ to address the gaps. There are many factors contributing to these problems with PBFPD. Research has been carried out in two principal problem areas: the relationship between occupants and fire safety measures in the context of holistic building performance expectations during everyday use of the building, and also the lack of specifics within current PBFPD approaches. To address these concerns, a new framework for risk-informed PBFPD has been developed, centered on the study of systems formed by specific building types and their associated occupants. This framework replaces generic guidance with a more in-depth and targeted “building-occupant” system approach. This article focuses on how a successful implementation of the new risk-informed PBFPD approach will require acceptance of the need for a paradigm shift from one in which fire is the center of the problem to one in which building performance metrics are evaluated in case of fire events. This article also details the different steps of the new PBFPD process and how this process differs from the current ones, notably in separating technical steps from political steps related to decision making and policy. Finally, this article presents how the new approach is practically applied to a project, focusing on a proof of concept of the new PBFPD process.     

基于模糊偏好规划与云计算的商场火灾安全评价模型

为解决商场火灾安全评价指标不确定性、随机性和模糊性导致决策者难以选择合适方法评价商场火灾安全的难题,提出基于模糊偏好规划与云计算的商场火灾安全评价模型。从火灾危险源、建筑防火能力、周边消防救火能力、人员疏散能力、日常管理能力、安全疏散力6 个方面构建评价指标体系。结合模糊理论和层次分析法,引进模糊偏好规划模型计算指标权重。借助云模型实现指标定性与定量两种特性的切换。用该方法评价郑州某商场火灾安全,结果认为火灾安全等级高,需关注可燃物分布、建筑特征、与消防队距离、人员分布、消防安全投入、疏散通道宽度6 个重要指标。研究可为商场日常火灾管理提供可行性建议。     

世界各国新研发消防产品大全

火山灰防火建材 日本鹿儿岛一家建研社新近开发一种利用火山喷出物制作的防火建材和外墙涂料,科学家对火山遗址的喷出物进行研究．发现在火山灰成分中有60％的玻璃质，加热至900摄氏度以上时,其中的水分可以蒸发,成为微小的构造物、再经过精心加工，就可以制成很好的防火隔热材料,能广泛地应用干建筑之中。     

A Water Requirements Estimation Model for Fire Suppression: A Study Based on Integrated Uncertainty Analysis

Rescue work is one of the main objectives of firefighting. To minimize casualties and financial losses, fire service agencies consider sufficient water supply for fire suppression to be the key among the many factors affecting firefighting. The difficulty of collecting water usage data from actual fire scenes has confined the research on water allocation for firefighting in either domestic or international arena mostly to theoretical studies. Consequently, the use of firefighting water resources often follows empirical methods or related government legislation, rather than being an effective practice verified by in-depth field investigation. This study, based on fire engineering theory, employs heat release rate combined with uncertainty analysis to develop a model for estimating water requirements for firefighting. Using firefighting cases at Taoyuan County in Taiwan, R.O.C., a quantitative analysis of the field data was integrated with uncertainty analysis to evaluate the suitability and uncertainty of the proposed firefighting water supply model. The result indicates that the proposed model of firefighting water requirements can effectively reflect water demand in an actual fire incident. Among the 100 cases tested, the actual firefighting water consumptions are averaged as 44.2 metric tons whereas the mean difference between the derived water requirements and the actual amount is approximately ±15 metric tons.     

基于无人机的三维消防辅助救援系统构建

为实现高效、科学、精准的灭火救援，提出利用无人机快速构建受灾体周边地理信息和受灾体三维模型的精准建模，并对火灾灾变因子进行实时监控，侦测火灾发展过程中气流、温度场、有毒有害气体等灾害因子的时空分布。利用低延时的5G网络和火灾灾变理论建立云端消防智慧大脑，对无人机采集的实时数据进行云端数学建模和计算处理，预测火灾可能的演变路径和灾变过程，形成根据实时灾害信息动态调整的消防救援决策方案。利用5G通信网络将无人机感知的灾变数据及动态救援决策方案实时传输给消防救援人员，提高灭火救援效率，避免灾害转戾所造成的消防人员伤亡。     

高层建筑火灾固定消防设施应用分析

战例分析是研究灭火战术的重要途径。高层建筑火灾战例是如实记录灭火救援过程和评价扑救成功与失利的主要依据,是消防基础工作中宝贵的信息资源。选取2000年以来全国战例研讨班交流的17起高层建筑火灾战例,统计了实战中固定消防设施的应用情况,分析了固定消防设施与控制火势蔓延、灭火力量投入、控火时间和灭火时间的关系。     

基于BIM的消防设备设计平台构建研究

为了解决消防设备设计工具不统一、设备数据信息未充分利用所导致的信息断层、设计效率低下、成本过高等问题,提出了利用建筑信息模型和云平台技术构建消防设备设计平台。平台以基础服务层、数据层、应用层、表现层组成整体架构,供多种格式模型解析并轻量化展示。各类设计功能满足多方用户的设计需求,通过去工具化的方式使得用户可以在线完成设计工作,摆脱BIM 设计工具的束缚。所构建消防设备库内BIM 模型提供多种几何信息与非几何信息,经多方流转可实现消防设备全生命周期内的信息共享,为“智慧消防”提供基础性服务。     

Towards improved characterization of high-risk releases using heterogeneous indoor sensor systems

The sudden release of toxic contaminants that reach indoor spaces can be hazardous to building occupants. For an acutely toxic contaminant, the speed of the emergency response strongly influences the consequences to occupants. The design of a real-time sensor system is made challenging both by the urgency and complex nature of the event, and by the imperfect sensors and models available to describe it. In this research, we use Bayesian modeling to combine information from multiple types of sensors to improve the characterization of a release. We discuss conceptual and algorithmic considerations for selecting and fusing information from disparate sensors. To explore system performance, we use both real tracer gas data from experiments in a three-story building, along with synthetic data, including information from door-position sensors. The added information from door-position sensors is found to be useful for many scenarios, but not always. We discuss the physical conditions and design factors that affect these results, such as the influence of the door positions on contaminant transport. We highlight potential benefits of multisensor data fusion, challenges in realizing those benefits, and opportunities for further improvement.     

Informative Fire Warning Systems

Successful evacuation of a building depends on early detection of a fire and timely and convincing communication to occupants about the location of the fire and its size and spread. These two requirements for increasing life safety can be met by computer-based Informative Fire Warning Systems (IFWS). This Technical Note reviews briefly research carried out in the United Kingdom on IFWS and the basic features desirable in such fire detection systems.     

Erster und zweiter Rettungsweg in Wohngebäuden

First and second escape ways in residential buildings The existence of two redundant escape ways is a fundamental concept to ensure a safe egress of occupants in the event of fire. Fire safety requirements for means of egress are defined by the state specific building codes in Germany. This publication focuses on a further clarification of existing requirements and amongst others explains why some means of egress, such as permanent installed ladders are not suitable for this purpose. However, in contrast to this fire service equipment can also provide the second escape way in particularly for residential buildings. Different means are used depending on the applied strategy and infrastructure of the fire service. A summary of reported fire incidents of the Berlin fire service in the years 2012 and 2013 shows that smoke filled stairwells were also used to evacuate trapped occupants. In order to protect these occupants from smoke intoxication, escape hoods or positive pressure ventilation fans, to allow for a smoke free stairwell, have been used.     

城市消防远程监控系统探索与实践

本文通过对城市消防报警系统联网和视频监控系统联网技术的研究,探讨城市消防远程监控系统的建设方案,实现对各联网用户单位不同厂家和不同型号消防报警系统和视频监控系统的组网,建立一个智能、高效、快速可靠的城市消防联网监控平台,自动将火警信息和现场图像实时传递到监控中心,满足消防部门指挥作战需要。     

老旧商业建筑火灾危险性评价系统研究

以老旧商业建筑的检测数据及相关资料调查为依据,采用模糊灰色综合评价法、层次分析法等最新信息处理技术构建老旧商业建筑火灾危险性评价模型。根据评价模型运用Visual Basic6.0编译老旧商业建筑火灾危险性评价系统软件。该系统软件可快速对某商业建筑室内火灾危险性进行评价并确定危险性等级,这不仅克服了利用评价模型进行人工手算时计算复杂、耗时久的弊端,还为老旧建筑进行防火改造提供一定理论依据。最后本文以一老旧商业建筑火灾危险性评价实例验证了该系统软件的可操作性。     

Robotic Fire Suppression Through Autonomous Feedback Control

A computer vision-based autonomous fire suppression system with real-time feedback of fire size and spray direction is presented in this paper. The system has been developed for use in a firefighting robot for close-range, localized fire suppression tasks in enclosed environments. A probabilistic water classification method was developed for segmenting water spray in a pair of IR cameras. Stereo processing was performed to localize points along the spray path for use in yaw and pitch angle estimation. A Golden Section Search with linear least squares optimization was used to determine the optimal pitch angle of the spray position at each sampling time. Kalman filtering was used to remove noise from the angle measurements and obtain a better estimate of the current nozzle orientation. A decision tree was used to determine the correct nozzle positioning mode using image feedback to suppress the fire and accounts for errors in direction, fire size during suppression, and when to adjust the nozzle based on IR feedback. Through implementation of a PI controller, the system is able to correct for unknown disturbances causing erroneous targeting of a localized fire. Experiments are presented with the initial nozzle angled correctly and with forced offsets in the system to set the initial spray position incorrectly in order for the system to correct. Suppression times ranged from 7.2 s to 16.3 s with a standard deviation of 3.9 s and average time of 11.2 s. A total of 12 tests demonstrated performance of the system given a forced offset to the initial nozzle orientation resulting in an error between the spray location and the fire target. Suppression times ranged from 8.1 s to 27.9 s with a mean of 16.9 s and standard deviation of 6.2 s. The proposed system can be implemented on a robotic firefighting platform to autonomously detect a fire, choose a proper manipulation goal and suppress full scale fires given disturbances causing erroneous targeting.     

建筑火灾中人员疏散响应过程推理与评估模型研究

为了预防建筑火灾发生和减少火灾中人员的伤亡,利用消防大数据分析技术和贝叶斯网络分析方法,研究了建筑火灾发展过程及人员疏散响应过程的推理与动态评估方法。通过对建筑消防设施响应状态和火灾中人员心理和行为特征的分析,探讨了火灾阶段划分方法和人员疏散行为的分类,提出了火灾中人员伤亡的轨迹交叉理论,进而构建了基于贝叶斯网络的建筑火灾动态风险和人员疏散安全评估框架。分别探讨了建筑火灾发展、人员疏散响应等2 条研究主线的推理过程,探讨了疏散条件评估过程。研究表明,该模型可通过对建筑特征、消防设施状态信息以及人员响应信息等消防大数据进行融合,实现火灾中人员疏散响应过程推理与动态风险评估,从而提高建筑消防安全管理水平     

机械停车库防火性能化没计案例分析

针对北京某医院宿舍楼配套地下机械停车库工程存在的主要消防设计问题进行分析研究,确定消防设计安全目标,进而对火灾场景、火灾规模、烟气控制和人员安全疏散等多方面问题进行了深入研究和探讨,提出适用于该项目的消防安全策略、评估方法和模型,为类似工程的实施提供了一定的借鉴经验。     

Findings of the International Road Tunnel Fire Detection Research Project

Fire detection systems are essential fire protection elements for road tunnels to detect fires, activate safety systems and direct evacuation and firefighting. However, information on the performance of these systems is limited and guidelines for application of tunnel fire detection systems are not fully developed. The National Research Council of Canada and the Fire Protection Research Foundation, with support of government organizations, industries and private sector organizations, have completed a research project to investigate current fire detection technologies for road tunnel protection. The project included studies on the detection performance of current fire detection technologies with both laboratory and field fire tests combined with computer modelling studies. This paper provides an overview of the findings of the project. Fire detectors, fire scenarios and test protocols used in the test program are described. A summary of the research results of the series of full-scale fire tests conducted in a laboratory tunnel facility and in an operating road tunnel as well as of the computer modelling activities will be reported.