Fire Accidents Research Articles

Dispersion and explosion characteristics of multi-phase fuel with different charge structure

The fuel dispersion and explosion laws are important for safety design of fuel charge, concentration prediction of accidental release vapor cloud and prevention of fire and explosion accidents. The charge structure is an important factor in determining the fuel dispersion and explosion performance. Experiments and numerical simulations are carried out for cylindrical, square and fan-shaped charge structures. The dispersion process, concentration distribution, explosion overpressure, component reaction and safety radius of 11 kg solid-liquid-gas propylene oxide (PO) are obtained. The results show that square and fan-shaped structure have local enhancement effect. Compared with cylindrical structure, the dispersion distance of square at 0° and fan-shape at 45° increase by 10.13 % and 14.39 % respectively. The peak overpressure increased by 8.85 % and 4.73 %. At 4 m, the remaining fuel of the three structures is 39.13 %, 22.34 % and 17.20 %, respectively. The equivalent safety radius is 14.20 m, 14.80 m and 14.27 m respectively.

Heritage BIM (HBIM) applied in emergency scenarios: a case study of the National Museum in Brazil

Heritage buildings, integral to preserving culture and history, play a vital role in shaping regional identity and collective memory. To address the intricate complexities of conserving such tangible cultural heritage, Heritage Building Information Modeling (HBIM) emerges as a compelling avenue, uniting technology, historic preservation, and architectural expertise. Nonetheless, a remarkable research gap exists, particularly in its application within emergency scenarios involving fire accidents during post-recovery phases. This research aims to bridge this gap by proposing key areas of focus for applying HBIM in the aftermath of fire incidents, redefining disaster recovery for heritage sites. The proposed areas are informed by a thorough assessment of the case study related to the post-recovery process undertaken by the Brazilian National Museum after the devastating fire of 2018. This case study combines gathering documentary evidence, on-site assessments, 3D model development within the BIM environment, and interdisciplinary collaboration. By emphasizing informed decision-making, precise damage assessment, and meticulous reconstruction planning, this study advances HBIM's transformative role in heritage conservation and disaster recovery, resulting in a novel approach to safeguarding cultural heritage.

Risk analysis of accident-causing evolution in chemical laboratory based on complex network

Chemical laboratories usually have many high risks from various dangerous chemicals, dangerous devices, and experimental operators involved in the laboratory. Once a severe accident occurs, the accident consequence will significantly impact scientific research innovation and social progress. Aiming at laboratory safety problems, an accident evolution model is established to reveal the critical accident-causing factors and the most likely evolutionary path of accidents in the process of accident evolution. Firstly, the 24 model is used to identify the cause factors of laboratory accidents and the causal relationship between factors. Then, the complex network model of laboratory accident evolution is constructed with accident-causing factors as nodes and causal relationships between factors as edges. Secondly, using the TOPSIS method, four typical complex network characteristic indexes, including degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality, are constructed into a comprehensive evaluation index to reveal the key influencing factors in the accident evolution process. Finally, the fuzzy number is introduced to quantify the uncertainty of the accident evolution path. The most likely evolutionary path is obtained through the Dijkstra and risk entropy theory. Based on the data of 151 laboratory accidents from 2001 to 2022, the accident evolution analysis of chemical laboratories was carried out. The evolution results show that the maximum probability value is the evolution path of fire accidents, and the minimum probability value is the evolution path of electric shock accidents, which accords with the general statistical law of accidents. When applied to the actual laboratory, the safety management level of the laboratory can be effectively improved by controlling the key influencing factors and cutting off the accident evolution path.

Egress Safety for STUDIO Residential Buildings

In recent years, the number of studio residential buildings has increased significantly in Korea, as well as in many other countries, due to changes in living patterns. In Korea especially, there have been many fire accidents in studio residential buildings, which have caused a huge number of casualties and property damages, because the buildings were not adequately equipped for firefighting. In this study, the egress safety of a typical studio residential building in Korea is analyzed. Fire simulations were performed with variables of the fire location and the capacity of the smoke exhaust system to estimate the available safe egress time (ASET); egress simulations were also performed with the variable of egress delay time, and the required safe egress time (RSET) was determined. Then, the egress safety was evaluated, and the criteria for egress safety evaluation were proposed based on the simulation results. A studio residential building with a floor plan different from the prototype was used to validate the proposed egress safety criteria. Finally, a simple evaluation model is presented to estimate the required safe egress time (RSET) without simulation and to examine the impact of bottlenecks.

Simulation of a Hazardous Chemical Cascading Accident Using the Graph Neural Network

In the storage of hazardous chemicals, due to space limitations, various hazardous chemicals are usually mixed stored when their chemical properties do not conflict. In a fire or other accidents during storage, the emergency response includes two key steps: first, using fire extinguishers like dry powder and carbon dioxide to extinguish the burning hazardous chemicals. In addition, hazardous chemicals around the accident site are often watered to cool down to prevent the spread of the fire. But both the water and extinguishers may react chemically with hazardous chemicals at the accident site, potentially triggering secondary accidents. However, the existing research about hazardous chemical domino accidents only focuses on the pre-rescue stage and ignores the simulation of rescue-induced accidents that occur after rescue. Aiming at the problem, a quantitative representation algorithm for the spatial correlation of hazardous chemicals is first proposed to enhance the understanding of their spatial relationships. Subsequently, a graph neural network is introduced to simulate the evolution process of hazardous chemical cascade accidents. By aggregating the physical and chemical characteristics, the initial accident information of nodes, and bi-temporal node status information, deep learning models have gained the ability to accurately predict node states, thereby improving the intelligent simulation of hazardous chemical accidents. The experimental results validated the effectiveness of the method.

SAPERI: An Emergency Modeling Chain for Simulating Accidental Releases of Pollutants into the Atmosphere

Timely forecast of atmospheric pollutants fallout due to accidental fires can provide decision-makers with useful information for effective emergency response, for planning environmental monitoring and for conveying essential alerts to the population to minimize health risks. The SAPERI project (Accelerated simulation of accidental releases in the atmosphere on heterogeneous platforms—from its Italian initials) implements a modeling chain to quickly supply evidence about the dispersion of pollutants accidentally released in the atmosphere, even in the early stages of the emergency when full knowledge of the incident details is missing. The SAPERI modeling chain relies on SPRAY-WEB, a Lagrangian particle dispersion model openly shared for research purposes, parallelized on a GPU to take advantage of local or cloud computing resources and interfaced with open meteorological forecasts made available by the Meteo Italian SupercompuTing PoRtAL (MISTRAL) consortium over Italy. The operational model provides a quantitative and qualitative estimate of the impact of the emergency event by means of a maximum ground level concentration and a footprint map. In this work, the SAPERI modeling chain is tested in a real case event that occurred in Beinasco (Torino, Italy) in December 2021, mimicking its use with limited or missing local input data as occurs when an alert message is first issued. An evaluation of the meteorology forecast is carried out by comparing the wind and temperature fields obtained from MISTRAL with observations from weather stations. The concentrations obtained from the dispersion model are then compared with the observations at three air quality monitoring stations impacted by the event.

Risk Analysis of Small LPG Storage Tank Explosion in the School Cafeteria

This study aimed to determine the best safety measures in case of accidental gas leakage, fire, or explosion in the LPG storage tank of a domestic school kitchen by analyzing the ranges potentially affected by toxicity, overpressure, and radiant heat. Using the Areal Locations of Hazardous Atmospheres (ALOHA) program, the range of damage impact of gas leakage, toxicity owing to VCE and boiling liquid expanding vapor explosion (BLEVE), overpressure, and radiant heat were analyzed for a 1,000 kg-capacity small LPG storage tank installed in the kitchen. It was classified into worst-case and alternative (local weather) scenarios, depending upon the weather conditions, and analyzed by dividing into 50% and 100% storage, as per the difference in storage. The observed risk of toxicity placed the entire school area at risk of death or disability. The risk of overpressure posed a threat to buildings in the entire school area and around the school. The risk of blasts revealed a risk of death up to a distance of 135 m, and the farther regions were at risk of second-degree burns. Additionally, the risks of toxicity and overpressure are affected by weather conditions and LPG storage, whereas blasts are primarily affected by LPG storage with minimal impact from weather conditions.

Study on Improving Fire Safety in Traditional Markets

In this study, we analyzed fire-safety management regulations and problems with fire-alarm equipment in traditional markets, as failures can cause significant damage in the event of a fire. We also present improvement measures based on analyzing major fire accidents. Traditional markets must designate the type of firefighting equipment installed at a store according to the number of stores, and apply this measure retroactively when the installation regulations are revised. If the market is designated as traditional, the equipment must be designated as a fire-safety management object, and the appointment of a fire safety manager, firefighting education and training, and self-inspection must be made mandatory. Fire-alarm equipment must be inspected regularly by a fire-safety manager, and fire-proof walls must be installed with self-supporting fire-resistant structures at certain sections. When designing a new traditional market, it must be designated after facility supplementation following safety inspection. In addition, traditional markets are required to have fire-detection equipment and automatic notification systems, and building-type traditional markets must retroactively install automatic sprinkler equipment.

Numerical and experimental investigations on thermal performance of Li-ion battery during explosion

Electric vehicles (EVs) are eco-friendly alternative to internal combustion (IC) engine based vehicles to combat with global warming. Lithium-ion batteries (LIBs) are adopted in EVs and their performance and longevity depends on thermal environment. Inadequate thermal management results in suboptimal performance, thermal runaway and consequent explosion in extreme cases. The present study delves into the experimental investigation on catastrophic failure of a Lithium ion cell under abusive conditions. The temperature variations leading up to the point of explosion were meticulously monitored, revealing a critical temperature of 440 K just before the explosion. The pressure waves during the explosion gives the sound pressure levels from 46.2 dB to 83.85 dB within a 34 ms time window and the predominant portion of sound generated during the explosion lies in the range of 129 to 3488 Hz. The battery pack discharge experiments show a temperature rises above the critical limit of 313.15 K and sudden voltage drops to the cut of value of 20 V at t = 850 s during 1C discharge condition, which shows the warning of explosion. Numerical model was developed to simulate the complex conjugate heat transfer in the cell and simulation results are validated. To underscore the practical implications, a case study of fire accident during battery cooling experiment was presented. From the insights gained by explosion of single-cell and fire accident of battery, several recommendations are provided, which includes the orientation of cells within the EVs aiming at the safety of battery design and operation.

Discussion on Fire and Explosion Prevention of Electrical Equipment

Electrical equipment fire and explosion-proof is to protect industrial production and daily life safety is an important task, in the context of the new era, the continuous development of science and technology, the types and number of electrical equipment is increasing, its fire and explosion-proof work is also facing new challenges. In this paper, on the basis of in-depth analysis of the causes of electrical equipment fire and explosion accidents, discusses the technical measures and management measures of electrical equipment fire and explosion prevention, in order to improve the safety of electrical equipment to provide reference.

Safely Managed Barbeque Use of Charcoal as Traditional Renewable Energy

While coal is a fossil fuel, traditional charcoal is an inherently renewable energy source. In addition to fuel, charcoal can also be used as a functional material such as adsorbents and catalysts. Charcoal is still used for heating in safe cooking situations, such as barbecues. However, in recent years in Japan, there have been many cases of barbecue fire accidents. This study is a case study in which the author experimented with charcoal (made from Malaysian mangroves) barbecue using a safe method within an established facility. Based on past fire incidents, the main causes are the ignition of liquid or fluid combustion aids, the spread of sparks bythe wind, and insufficient trailing fire. In this case study, under calm wind conditions (artificially fanning at an appropriate level of strength), using a solid firelighter, and collecting used and extinguished charcoal ash in a metal container, these three points was found to be important for safety fire management in barbeque.

Redundant series cell voltage measurement circuit design of battery management system for functional safety

In most battery management system (BMS) circuit designs, the analog front end (AFE) chip is used to get the series cell voltage of the battery pack. However, it can lead to incorrect calculations by the BMS, causing errors in battery information, failures in protection control, and triggering a battery system fire accident if the AFE chip is abnormal. Unfortunately, the BMS will never know the correct of measured results if it is measured by a single AFE chip. This paper proposes a redundant series voltage measurement system (RSVMS) for the series cell voltage of the battery pack. The original AFE is referred to as the main AFE (m-AFE). The RSVMS can be regarded as redundant AFE (r-AFE). In this paper, the r-AFE consists of a series cell selector and an analog-to-digital (ADC) converter with an isolated communication function to transmit measurement results to the microcontroller unit (MCU) of the BMS. Due to the hardware requirements of functional safety, it does not allow using two identically designed hardware as redundant systems. To satisfy the hardware level of functional safety and to minimize the hardware cost and size, the series cell selector of r-AFE shares the same hardware circuit as the Active Hybrid Equalizer Circuit (A-HEC). The cell selector of A-HEC is composed of the back-to-back MOSFET switch array with a simple ON/OFF function. The MCU of BMS will identify the abnormal of voltage measurement results when the difference of m-AFE and r-AFE is over the threshold. In summary, r-AFE can ensure the accuracy of cell voltage measurement for m-AFE to avoid significant errors when estimating battery information and avoid disaster caused by failure or malfunction of protection functions. In addition, the m-AFE and r-AFE are two independent designs to avoid similar errors caused by identical circuit configurations.

Influence of fire severity and concrete properties on the thermo‐hygral behavior of concrete during fire exposure

AbstractSince the world is transitioning toward performance based design, the study of thermo‐hygral behavior of concrete when subjected to real fire becomes crucial. Fire accidents have revealed that nominal fire curves cannot be applied because of varying severity of real fire. In 2008, traveling fire concept was developed in which severity is dependent on heat release rate and fire size. This study explores the effect of fire severity and other concrete properties like strength, aggregate type, and relative humidity. The proposed model has been developed by combining the principles of mechanics and thermodynamics and upon validation with the experimental results, a reasonable agreement has been observed. It can be concluded that severity of fire is directly related to thermo‐hygral behavior of concrete. On the other hand, this study also highlights the influence of type of aggregate and moisture content in addition to the traditional variables like volume fraction of solid and permeability. On studying the influence of type of aggregate, it can be concluded that recycled aggregate concrete performed better than conventional concrete. The integration of proposed model in the performance based design is a leap toward development of resilient structure subjected to dynamic fire conditions.

Predicting the entire pyrolysis process of representative charring material infiltrated with kerosene using an improved artificial neural network

It is crucial to predict the entire pyrolysis process of charring materials infiltrated with flammable liquids to provide guidance for reducing the fire hazards and implementing numerical simulations of fire accidents caused by the leakage of flammable liquids. In the present study, pyrolysis data obtained from the thermogravimetric experiments were preprocessed using linear interpolation and data normalization methods. The processed data set was then used to train the artificial neural network (ANN) framework to predict the pyrolysis behaviors of typical charring material (Mongolian Scots pine) infiltrated with typical flammable liquid (kerosene) under three different conditions: (1) pyrolysis at a constant mass fraction of kerosene with multiple heating rates; (2) pyrolysis at multiple mass fractions of kerosene with a constant heating rate; and (3) pyrolysis at multiple mass fractions of kerosene and multiple heating rates. The ANN, with the double hidden layer structure (6−3), was capable to well predict the entire pyrolysis behaviors of Mongolian Scots pine under all the three scenarios. Besides, five data transformation function (multiplication, exponential function with base e, logarithmic function with base e, square root, and exponentiation function) were applied to the present three input variables (temperature, mass fraction of kerosene, and heating rate) to generate new input variables in order to extract more characteristics among the pyrolysis data. Therein, the ANN utilizing the data transformation functions of multiplication and exponential function with base e exhibited the best predictive ability. Among the three input variables in the ANN (temperature, mass fraction of kerosene, and heating rate), temperature was identified as the most sensitive one to the prediction performance, followed by mass fraction of kerosene, with heating rate being the least sensitive.

Study on thermal runaway propagation characteristics of the lithium-ion battery module by two-phase flow of nitrogen and water mist in longitudinal ventilation environment

To prevent and control the thermal runaway (TR) and its propagation of lithium-ion batteries (LIBs) is a key problem for its sustainable development and wide application. However, there is still a gap in the research on the characteristics of two-phase flow of nitrogen(N2) and water mist (NWM) controlling TR and its propagation in different longitudinal ventilation environments. In this study, the influence of wind velocity on 0.5 MPa NWM to control TR and its propagation characteristic parameters of LIB module was studied experimentally. The results show that with the increase of wind velocities, the opening time of the safety valve and TR trigger temperature of the LIB module gradually increased. At the same wind velocity, TR trigger temperature of cell 1 to cell 5 was successively reduced after 0.5 MPa NWM was applied. The cooling and asphyxiation effect of 0.5 MPa NWM is the best in natural ventilation environment, but the suppression effect of 0.5 MPa NWM on TR propagation of the LIB module is weakened under the influence of forced ventilation. However, different wind velocities have little effect on TR trigger temperature of the blocked LIB module. At the same time, a quasi-steady state thermal equilibrium of the NWM in a ventilation environment was established for the LIB module, and the influence of the coupling effect of different longitudinal ventilation environments and 0.5 MPa NWM on TR propagation characteristic parameters of the LIB module and the heat transfer mechanism in the thermal runaway propagation process were compared under the two conditions of within or without battery case. It is found that the convection effect of the wind plays a leading role in the heat dissipation of the blocked LIB module when the wind velocity is less than 4.5 m/s. The heat conduction of the battery case plays a leading role when the wind velocity is greater than 4.5 m/s. Moreover, in any ventilation environments, TR propagation time of the blocked LIB module is smaller than that of the unblocked LIB module. Under the same wind velocity, TR trigger temperature of the blocked LIB module and the maximum temperature of each cell are higher than that without battery case. This work provides a new perspective for controlling TR propagation of the LIBs. At the same time, it can provide theoretical guidance for ensuring process safety and firefighters to fight LIB fire accidents.

Estimating the Acute Health Effects of Smoke Exposure from an Urban Factory Fire Accident: A Case Study of a Tire Factory Fire in Korea.

A major industrial fire accident occurred in a tire manufacturing factory in Daejeon, Korea, on 12 March 2023 and lasted for 3 d, generating air pollutant emissions. Although evidence regarding the health effects of urban fires is limited, residents near tire factory may have experienced health hazards due to smoke exposure from fire plumes. Capitalizing on the timing of this fire incident as a natural experiment, we estimated the attributable excess air pollution exposure and associated disease development among residents living near the tire factory. We used the generalized synthetic control method to estimate air pollution exposure and health burden attributable to the accident among residents living in smoke-exposed districts. Based on satellite images and air pollution monitoring results, three administrative districts (within from the factory) were defined as smoke-exposed, and the other 79 districts of Daejeon were defined as controls. Among the 11 monitoring stations in Daejeon, the station located from the factory was used to estimate excess air pollution exposure (, , , , , and CO) for residents in the exposed districts. The number of daily district-level disease-specific incidence cases were acquired from the National Health Insurance Database and used to estimate excess health burden resulting from the fire. During the first week following the factory fire, residents of exposed districts had an estimated excess exposure to 125.2 [95% confidence interval (CI): 44.9, 156.7] of , 50.4 (95% CI: 12.7, 99.8) ppb of , and 32.0 (95% CI: 21.0, 35.9) ppb of . We also found an average increase in the incidence cases of other diseases of upper respiratory tract [20.6 persons (95% CI: 6.2, 37.4)], lung disease due to external agents [2.5 persons (95% CI: 2.1, 3.3)], urticaria and erythema [5.9 persons (95% CI: , 11.2)], and episodic and paroxysmal disorders [8.5 persons (95% CI: 3.7, 13.4)] in exposed districts. Excessive air pollution exposure and disease incidence were identified among residents living close to the tire factory. Preventive measures, such as a warning system, to avoid health impacts to people breathing fire-related pollution may be beneficial for communities impacted by such events. https://doi.org/10.1289/EHP14115.

Mechanisms of water layer thickness and ullage height on crude oil boilover: a theoretical model coupling the effects of multiple physical fields

Boilover is one of the most destructive tank fire scenarios. A series of experiments were conducted using eight different depths of oil pans (ranging from internal depths of 4 to 20 cm) to vary the water layer thickness and ullage height. The results indicate that the water layer effectively cools the sidewalls, reduces the burning rate, inhibits the development of hot zones, and delays the onset of boilover in small and medium-scale experiments. Conversely, the ullage height affects the burning rate, formation of hot zones, intensity of the boilover, and boilover onset time. Utilizing experimental data and thermodynamic analysis, both water layer thickness and fuel layer thickness were considered as variables to predict sidewall temperature at the fuel surface. These results were then introduced into the burning rate prediction model. A prediction model for the boilover onset time was also developed using the water layer thickness as a variable, and a thermodynamic analysis revealed the existence of a limit to the effect of water layer thickness on the boilover onset time. Bubble dynamics was introduced to analyze the boilover process at the oil-water interface, clarifying that the influence of water layer thickness and ullage height on boilover intensity primarily lies in factors such as the degree of superheat at the fuel-water interface. The study’s findings hold significant implications for predicting and assessing fire accidents in storage tanks.

Experimental investigation of aging effects on thermal behavior of lithium-ion batteries during charging process

Thermal runaway generated by lithium-ion batteries is considered as one of the major hazards that exhibits great thermal risk during operation. The aging behavior, as an inevitable phenomenon after long-term cycling, largely contributes to the deterioration of thermal characteristics. In this paper, comparative experiments were conducted to investigate the aging cell thermal performance during the charging process. The results indicate that the aging cell with a high charging rate presents a higher thermal risk. With the decrease of SOH, the anode structure was destroyed and side reactions reduced the thermal stability. The thermal runaway onset temperature decreased from 274.8 ± 9.1 °C for fresh to 238 ± 1.2 °C for aging cells, and the corresponding critical time shortened by approximately 1 min. In addition, the maximum heat release rate increased by 37.5 %–45.5 % for aging cells under high charging conditions, manifesting that aging cells are more prone to trigger fire accidents. Finally, a modified risk assessment method was established. This study contributes to comprehending the coupling effects of aging behavior and charging rate thermal runaway mechanisms, and provides valuable guidance for thermal runaway detection during the whole life.

Robust and ultra-sensitive self-powered fire warning sensor based on polyimide thermoelectric fibers for temperature sensing and intelligent fire safety monitoring

Fire warning sensors is crucial to effectively prevent fire accidents in a variety of modes and meet the needs of the connected age. Nevertheless, there is still a formidable challenge in fabricating self-powered fire warning sensors that are flexible and can be integrated in combustible materials. In this work, flexible high-fireproof polyimide (PI)/hydroxyapatite (HAP)/Ag2Se composite aerogel fiber (PHA-AF) was fabricated by specific wet spinning technology. The extraordinary thermoelectric effect of Ag2Se enabled PHA-AF to achieve precise temperature sensing over a wide temperature range of 100 °C–500 °C. Simultaneously, the PHA-AF-based fire alarm sensor could trigger a fire alarm system in 1.9 s and respond continuously for 14 s under flame attack, while generating output voltage of up to 5.9 mV in self-powered mode. Notably, PI as a flame-retardant material could be formed the 3D networks with HAP, as well as the skeleton support effect provided by Ag2Se nanorods enabled PHA-AF based fire alarm sensors with superior breaking tenacity (2.9 MPa), strong heat stability (maximum weight loss rate at 550 °C) and flame retardancy (LOI = 35.8 %), further highlighting its authenticity, repeatability, and reliability in fire. This work offers potential for the preparation of fiber-based self-powered early fire alarm sensors for long-term continuous using in harsh fire environment.

Aplikasi Sistem Informasi Geografis Persebaran Lokasi Pos Pemadam Kebakaran Berbasis Android

Cirebon District Fire Service which serves the community and helps the community when a fire accident occurs. Information about the location of the nearest fire station is not widely known by some people. This of course hampers the process of fire disaster management and services for the community. The purpose of this research is to produce a Geographical Information System application for the distribution of fire station locations based on Android that can be easily accessed by the public. Geographical Information System uses Hybrid Mobile technology which is implemented into the Dart and Flutter programming languages. In this study, the data collection techniques used were observation, interviews and literature study, with the testing method using blackbox testing. From the results of the system implementation, it can be concluded that using the Android-based Geographical Information System Application can help and provide convenience for the community in obtaining information and assistance regarding the location of the nearest fire station.