Fire最新文献

{"title":"Scaling Landscape Fire History: Wildfires Not Historically Frequent in the Main Population of Threatened Gunnison Sage-Grouse","authors":"William L. Baker","doi":"10.3390/fire7040120","DOIUrl":"https://doi.org/10.3390/fire7040120","url":null,"abstract":"The main population of ~5000 threatened Gunnison sage-grouse (GUSG; Centrocercus minimus) in Colorado depends on sagebrush plants that are killed by wildfires, with recovery taking decades, so frequent fire is a threat, but did it occur historically? Early land surveys showed that the historical (preindustrial) fire rotation (FR), the expected period to burn area equal to a focal land area, was 90–143 years in GUSG ranges, which is not classed as frequent fire (≤25 years). However, recent research, based on fire scars on trees at ten sites near sagebrush, suggested some frequent fire historically in the main population. That study was not spatial, essential to estimate FR, so spatial data were created in GIS with land-survey reconstructions, survey dates, fire-scar sites, mapped sagebrush, and Thiessen polygons around sites. The previous study assumed fires that burned 2+ sites likely burned across sagebrush. Historical FRs were calculated several ways over a common period. A recovery estimate of FR was 90–135 years, a land-survey estimate was 82–131 years, and three spatial scar-based estimates were 93–107 years, showing agreement. However, the comparison found that only 8.8% of the land-survey fire area was detected at fire-scar sites. Detailed analysis showed that 10 fire-scar sites were insufficient to detect historical fire sizes and distributions across the large 168,753 ha sagebrush area. Adequate fire reconstruction could require ~45–60 fire-scar sites, making it feasible to study only ~30,000 ha of sagebrush. Using the two remaining methods, which cross-validate, showed frequent fire did not occur historically in the study area, as historical FRs were 82–135 years.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"59 167","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140735047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Experimental Analysis of Biochar Combustion in a Traveling Grate Furnace","authors":"T. Ferreira, J. M. Paiva, Carlos Pinho","doi":"10.3390/fire7040118","DOIUrl":"https://doi.org/10.3390/fire7040118","url":null,"abstract":"The current energy policy targets reducing energy dependence and minimizing pollutant emissions. Therefore, with the growing interest in using biomass as an alternative energy source, conducting scientific studies on its behavior and optimizing the respective conversion systems has become imperative. The present study focuses on investigating the combustion of biochar pellets in a laboratory-scale traveling grate furnace at three different bed temperatures: 700, 750, and 800 °C. The biochars were obtained via the carbonization process of Pinus pinaster, Acacia dealbata, and Cytisus scoparius pellets. The biochar combustion was studied using a moving-bed carbon particle burning model, supported by kinetic information which was obtained via the combustion of the same biochars in a bubbling fluidized bed. The diffusive parameter which was representative of this traveling grate combustion technology was determined, particularly the bed bypass factor. The combustion tests were carried out with the incomplete combustion of the char pellets. In general, the increase in biochar size led to a decrease in the bypass factor. However, the furnace temperature did not influence this parameter.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"38 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140737670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Experimental Study on the Thermal Runaway Propagation of Cycling Aged Lithium-Ion Battery Modules","authors":"Zhuxin Han, Lu-shan Zhao, Jiajun Zhao, Guo Xu, Hong Liu, Mingyi Chen","doi":"10.3390/fire7040119","DOIUrl":"https://doi.org/10.3390/fire7040119","url":null,"abstract":"The primary concerns for individuals using lithium-ion batteries (LIBs) are aging and thermal runaway (TR). This paper focuses on the thermal runaway propagation (TRP) of cycling aged LIB modules. The impacts of state of charge (SOC), state of health, and cyclic aging temperature on TRP in LIB modules are investigated. The analysis includes parameters such as temperature, voltage, and mass of the modules during TRP. It was found that as SOC increases, the maximum increase in temperature and maximum temperature rate of the modules increased, as did the total mass loss and smoke emissions. The average heat transfer between adjacent cells was higher for the lower SOC. Cycle aging reduces the thermal stability of LIBs, leading to a lower maximum temperature and maximum temperature rate, as well as a larger mass loss compared with fresh battery modules. Regarding aging temperature, low-temperature aging reduces the total duration of TRP compared with room temperature, but it increases the maximum temperature rate and causes greater mass loss. Aging also increases the average heat transfer between adjacent cells.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"44 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140736829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Bubbling on Ignition of PMMA Slab: Change in Thermo-Physical and Thermo-Radiative Properties","authors":"Chloë Vincent, C. Longuet, L. Aprin, Pierre Slangen, G. Rambaud, Laurent Ferry","doi":"10.3390/fire7040117","DOIUrl":"https://doi.org/10.3390/fire7040117","url":null,"abstract":"In semi-transparent polymers, ignition is not only dependent on conductive thermal transfer into the material but also on in-depth absorption of the radiation. The aim of this work was to investigate the influence of bubbling on the thermo-physical and thermo-radiative properties of PMMA and how it may affect its ignition. PMMA plates of varying thickness were exposed to the heat flux of two radiative sources with different emission spectra. Exposure was stopped after different periods of time to study bubbling kinetics and bubble size distribution by optical microscopy. Front and back surface temperatures of samples were recorded during heat exposure. The results indicate that the bubble size distribution is closely related to the temperature gradient within the sample. Steep thermal gradients lead to small-sized bubbles underneath the exposed surface, while weak thermal gradients generate a wider size distribution with in-depth bubbling. All thermo-physical quantities k, ρ and Cp were shown to decrease with increasing bubbling degree. Likewise, it was highlighted that bubbling modifies the thermo-radiative properties of PMMA, especially in the near-infrared range. Transmittance decreases while absorbance increases with a bubbling degree. The increase in the absorption coefficient was attributed to multiple scattering by bubbles that expand the pathway of radiation into the materials. It was concluded that changes in both the thermo-physical and thermo-radiative properties with bubbling were likely to account for the delay in ignition observed when using the near-infrared heating source.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"594 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140749670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Performance of Outdoor Mechanical Garages under Combustion Conditions","authors":"Yin Zhang, Zuocai Wang, Yang Li, Hongsheng Ma, Zhan Guo","doi":"10.3390/fire7040116","DOIUrl":"https://doi.org/10.3390/fire7040116","url":null,"abstract":"In this paper, the firing process and structural failure behavior of outdoor mechanical car parks are innovatively investigated under diverse conditions, leveraging fire experiments, FDS fire simulation, and finite element simulation. The fire experiments reveal the intricate interplay between flame spread and airflow, highlighting the enhanced risk of fire propagation among adjacent spaces. The temperature profile, mirroring the fire’s lifecycle, is delineated into three distinct stages: initial growth, full development, and eventual decay. Notably, full-scale fire simulation in FDS validates the experimental outcomes, underscoring the scalability and reliability of our scaled-down experiments. Furthermore, finite element simulations offer a profound understanding of structural safety in various parking spaces during a fire. Critically, the susceptibility of columns to failure underscores the imperative need for enhanced fire prevention measures in column design, representing a significant advancement in fire protection engineering.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"257 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140751403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized Machine Learning Model for Fire Consequence Prediction","authors":"Wei Zhong, Shuangli Wang, Tan Wu, Xiaolei Gao, Tianshui Liang","doi":"10.3390/fire7040114","DOIUrl":"https://doi.org/10.3390/fire7040114","url":null,"abstract":"This article focuses on using machine learning to predict the distance at which a chemical storage tank fire reaches a specified thermal radiation intensity. DNV’s Process Hazard Analysis Software Tool (PHAST) is used to simulate different scenarios of tank leakage and to establish a database of tank accidents. Backpropagation (BP) neural networks, random forest models, and the optimized random forest model K-R are used for model training and consequence prediction. The regression performance of the models is evaluated using the mean squared error (MSE) and R2. The results indicate that the K-R regression prediction model outperforms the other two machine learning algorithms, accurately predicting the distance at which the thermal radiation intensity is reached after a tank fire. Compared with the simulation results, the model demonstrates higher accuracy in predicting the distance of tank fire consequences, proving the effectiveness of machine learning algorithms in predicting the range of consequences of tank storage area fire events.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"39 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Multicriteria Geographic Information System Analysis of Wildfire Susceptibility in the Andean Region: A Case Study in Ibarra, Ecuador","authors":"Paúl Arias-Muñoz, Santiago Cabrera-García, Gabriel Jácome-Aguirre","doi":"10.3390/fire7030081","DOIUrl":"https://doi.org/10.3390/fire7030081","url":null,"abstract":"The uncontrolled spread of fire can have huge effects on ecosystems. In Ecuador, in 2022, wildfires caused a loss of 6566.66 hectares of vegetation cover. Ibarra is an Andean canton that has also been exposed to wildfires and their effects. The aim of this study was to map wildfire susceptibility in the Ibarra canton. Seven factors that directly affect these fires were examined: precipitation, temperature, water deficit, potential evapotranspiration, slope, proximity to roads, and land cover and land use. The variables were reclassified using Geographic Information Systems and a multicriteria analysis. The results showed that Ibarra has four susceptibility categories: very low, moderate, high, and very high. The more susceptible areas are those considered to have high and very high exposure, occupying 82% of the surface. Consequently, the most susceptible land covers are crops, pastures, shrub vegetation, and forests.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"139 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140078190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Studies on the Efficacy of Water Mist to Suppress Hydrocarbon Fires in Enclosures","authors":"Khaled Moinuddin, H. M. I. Mahmud, Paul Joseph, Grant Gamble, Brigitta Suendermann, Cameron Wilkinson, James Bossard","doi":"10.3390/fire7030083","DOIUrl":"https://doi.org/10.3390/fire7030083","url":null,"abstract":"Fire is one of the most undesirable events onboard a ship. The engine room is one of the most critical spaces in the ship in terms of fire protection, as it includes machinery, hydrocarbon fuel systems, and different electrical equipment. With the phasing out of Halon 1301 as a fire suppressant over recent decades, there has been an intensive effort to explore the efficacy of water-mist spray in mitigating fires within machinery spaces. This exploration entails a comprehensive investigation through experimental and simulation studies aimed at identifying suppression mechanisms and evaluating their effectiveness. While experimental setups typically encompass measurements of gas temperature, thermal radiation heat flux, oxygen concentration, and fire extinction time, limited attention has been paid to quantifying the heat release rate (HRR), a crucial indicator of fire magnitude. Furthermore, research into shielded fire scenarios remains sparse, despite their significance in maritime fire dynamics. Addressing shielded fires with water mist proves particularly challenging due to the potential obstruction impeding the direct interaction between the fire source and the water droplets. In the existing literature, most of the computational fluid dynamics (CFD) modelling of fires and suppression was performed using a Fire Dynamics Simulator (FDS). Alternate studies were performed using FireFOAM. and very few employed FLUENT and other analogous software codes. In the majority of reported computational studies, the determination of HRR was typically relied upon for its calculation derived from the measured data of fuel mass loss rate. Moreover, certain studies were undertaken for numerical simulations without conducting thorough model validation, either by omitting validation altogether or solely validating against dry fire experiments (i.e., without water-mist suppression). This critical review of the literature has identified several notable research gaps in the context of extinguishing hydrocarbon fires utilising water-mist spray, warranting further investigations. Additionally, this review paper highlights recent advancements in both experimental and numerical investigations pertaining to the efficacy of water-mist fire-suppression systems in enclosed spaces regarding hydrocarbon fires.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"137 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140078205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Smoke Exhaust Volume and Smoke Vent Layout on the Ceiling Centralized Smoke Exhaust Effect in Tunnel Fires","authors":"Youzhi Shi, Shixiong Qian, Pengju Zhao, Pan Guo, Zihe Gao","doi":"10.3390/fire7030078","DOIUrl":"https://doi.org/10.3390/fire7030078","url":null,"abstract":"This research focuses on the impact of smoke exhaust volume and smoke vent layout, which are two crucial factors affecting the smoke control efficiency in tunnels, on the smoke exhaust effect in tunnel fires. Numerical simulation methods are employed to investigate the impact of changing the smoke exhaust volume and the smoke vent number on the smoke exhaust performance in a curved tunnel with a ceiling centralized smoke exhaust system. This research primarily examines the length of the smoke distribution, the smoke temperature under the ceiling, the vertical visibility, and the exhausted smoke mass flow rate. The findings indicate that, in a tunnel with a single-side ceiling centralized smoke exhaust mode, an imbalance in smoke distribution occurs between the upstream and downstream of the fire source. The upstream area experiences a higher amount of smoke, while the downstream area has thinner smoke. Increasing the smoke exhaust volume yielded positive effects on smoke control, as evident in the reduced the smoke spread range, and improved the smoke exhaust efficiency. The influence of changing smoke vent number on the smoke exhaust effect was dependent on the smoke exhaust volume. When the smoke exhaust volume was excessive, altering the number of smoke vents had a minimal impact on smoke exhaust, while in cases with small smoke exhaust volumes, changes in smoke vent numbers obviously influenced the smoke control effect. Therefore, selecting an appropriate smoke exhaust volume and raising the smoke vent number can effectively optimize the performance of the ceiling centralized smoke exhaust system.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"45 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140085663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Comparison of Maximum Heat Release Rates of Thermoplastics in Open and Compartment Fire Environments","authors":"Hong-Seok Yun, Cheol-Hong Hwang","doi":"10.3390/fire7020056","DOIUrl":"https://doi.org/10.3390/fire7020056","url":null,"abstract":"Consideration of appropriate fire scenarios in the simulations of the Fire Dynamics Simulator (FDS) for the fire-risk assessment of buildings is a critical factor in the development of prevention and response measures. The user dependence of the FDS input parameters can threaten the reliability of the fire-risk assessment. An experimental study was conducted to establish correlations for considering appropriate fire scenarios using polymethyl methacrylate. To examine the changes in the maximum-heat-release rates (HRRs) according to the combustion environment, nine burners varying in size at 25 mm intervals were burned in open and compartment environments. The results indicated that compared with the fire phenomenon in the open environment, the maximum HRR and fire growth rate of the compartment fire were increased by factors of 3–50. Additionally, the compartment fire phenomena could be classified into three stages according to the changes in the aforementioned two physical quantities. An analysis of the experimental results revealed a correlation for predicting the maximum HRR of a compartment fire with various ventilation conditions using only the experimental results for the open environment. The maximum HRR predicted through this correlation exhibited an error of <15% relative to the values measured in the experiment.","PeriodicalId":508952,"journal":{"name":"Fire","volume":"323 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139833960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}