Fire Technology最新文献

Fire safety urgently requires better automatic early fire detection. While vision-based methods are promising, a clear benchmark for deep learning models tailored for this specific area has been lacking. This paper presents the first comprehensive vision-based benchmark of 33 deep learning models explicitly for automatic fire detection. The key novelty is the creation and utilization of a unique, real-world thermal infrared (IR) dataset derived from controlled room fire experiments by NRC Canada. This challenging dataset includes imagery of early-stage and fully developed fires, as well as variations from different test conditions. To assess broader applicability, model generalization was also evaluated using a general dataset (used in pre-training). By rigorously testing these models on both specialized and general datasets using multiple performance metrics (accuracy, speed, reliability, generalization, computational cost), this work establishes the first dedicated benchmark for deep learning in vision-based fire detection. This benchmark provides a novel and crucial resource for researchers to make informed decisions when selecting deep learning models for their specific fire detection applications, ultimately aiming to accelerate innovation and the development of more effective and reliable vision-based fire safety systems.

In the last decades, the domain of pool fire behavior in confined environments has received growing attention, primarily attributed to the increasing occurrence of industrial fire accidents and the need for enhanced fire safety protocols in urban constructions where confined environments are commonly present. The current review synthesizes a total of 136 relevant literature and aims to provide insight into existing challenges and possible future works. This review highlights the influences of critical factors on fire behavior and the characteristics and characterization methods of typical compartment pool fire behavior. Based on a careful and logical analysis of collected publications, the development, advantages, limitations, and potential improvements of current research are thoroughly discussed. Consequently, the key observations are given below: 1. Most studies on mechanically ventilated fires have neglected the effects of exhaust location and horizontal fuel location; 2. The heat feedback mechanism in well-mixed environments and the complexity of air entrainment across natural and forced convection demand further investigation; 3. Studies on oscillatory combustion remain difficult to generalize due to its transient and unstable characteristics; 4. The competitive formation of CO and soot should be explored chemically.

The catastrophic effect of fire incidents such as loss of lives, damage to building structures and economic loss, underscore the need for efficient fire safety in buildings, which has been a major subject of discussion in the UK. In this study, a comprehensive review of literature pertinent to building fire safety in the UK is presented. The study adopts systematic review approach, collected data from Scopus and analysed 51 qualified articles quantitively and qualitatively. The review shows a rise in publication since 2004, revealing prominent authors and keywords in building fire safety research. The review further identified the categories of fire safety practices in the UK, including technological innovations, mitigation, behavioural, and regulatory measures. Notable findings reveal the challenges in current practices including compliance and enforcement issues, maintenance of fire safety systems, public awareness and behavioural issues, technological adoption and integration challenges, and infrastructure and building design challenges. To address the challenges identified, proposed recommendations include fire safety training, simplifying and unifying regulations, maintenance and inspection of fire safety systems, fostering and upholding public trust, enhancing public awareness, integration of advanced technologies, and formulation of fire safety strategies. Additionally. the study further recommends more comparative research on international fire safety practices and social factors influence on fire regulations to effectively enhance fire safety practices in the UK.

This study investigates how three types of thin intumescent coatings, applied at different Dry Film Thicknesses (DFTs), influence the charring behaviour of mass timber in fire, including the effects of varying heating conditions. Bench-scale timber samples of Cross-Laminated Timber (CLT) were tested for 60 min at a constant 25, 50, or 75 kW/m² incident radiant heat flux. Tests were conducted on timber samples painted with opaque coatings (solvent-based Coating A and water-based Coating B) and a transparent coating (water-based Coating C), as well as bare timber samples as a control. Three DFT thresholds were considered for each coating, spanning 0.98–2.60 mm for the opaque coatings and 0.18–0.40 mm for the transparent coating. The findings demonstrated that, although coated timber still chars, the onset of charring is significantly delayed compared to bare timber. For the opaque coatings, this was dependent on both thickness and heat flux, whereas for the transparent coating, the insulating efficacy was primarily governed by the heat flux – with its durability markedly compromised above 25 kW/m². Compared to bare timber, opaque coatings A and B showed reductions in mean charring rates of up to 70%, 62%, and 56% under heat fluxes of 25, 50, and 75 kW/m², respectively. In contrast, timber with transparent Coating C achieved mean charring rate reductions of up to 36%, 18%, and zero under the same heat flux conditions. The main conclusions from the study were: (1) opaque coatings are more effective than the transparent coating in reducing timber charring; (2) higher heat flux conditions reduce the effectiveness of intumescent coatings for all coating types; and (3) while increased DFT generally reduced charring of coated timber, particularly for opaque coatings A and B samples, it was insufficient to offset the effects of higher heat flux intensity in timber samples with transparent Coating C - especially at 50 and 75 kW/m².

Graphical Abstract

Chimney-passage is a critical point in terms of fire safety in buildings, and the high number of fires occurred in recent years despite the chimney certification procedure, has shown the need to evaluate these aspects. This paper evaluates the reliability of European reference standards and determine if any revisions are necessary. Experimental tests aimed at comparing the temperature measured in a roof- and wall-passage, have been conducted at gas temperatures of 207, 260, 310, 410, and 520 °C on building elements 200 mm thick. A metal chimney with a diameter of 200 mm, insulated with 2.5 cm of mineral wool, was used in the tests. Key findings include temperatures approximately 13 °C higher at the wall passage. While these differences are not substantial enough to pose significant safety hazards, they highlight the need for further investigation to fully assess the potential risks. The temperature distribution along the chimney’s circumference was non-axisymmetric, with differences ranging between 8 and up to 15 °C, with the highest temperatures at the top of the passage. Additionally, the analysis of the test procedure has highlighted that the close proximity of the heat generator to the wall passage could result in gas temperatures much higher than those observed during certification. Findings here reported lay the groundwork for further experimental and numerical studies on fire safety in chimney installations.

“Travelling fires” discriminate a fire plume at the near-field and a hot smoke layer preheating the ceiling at the far-field, with the intent of ensuring the robustness of structural design for large compartments under realistic fires. Once the fire is “travelling”, the near-field has a leading edge representing the fire spread, and a trailing edge representing the burnout of the fuel. Despite the recognised effects of travelling fires, the mainstream of efforts into their effect on structural response has been limited to 2D models using the finite element method (FEM). This paper aims to identify the importance of slab inclusion with a 3D FEM structural model for steel-composite structures under travelling fires, assessed against the corresponding simplified 2D structural frame models (i.e., with and without effective slab in the 2D steel frame model). The first step is a comparative structural analysis of a prototype composite structure under various design fire scenarios, including standard fire, parametric fires and travelling fires. The role of the fire protection scheme for the simplified 2D models against the 3D model for the numerical predictions is also explored. It is found that the structural load path, and the potential structural failure mechanisms, could be fundamentally different between the 3D model and the simplified 2D models. Although the 2D frame model tends to predict larger deflections (i.e., more conservative) than the 3D model, it could also significantly underestimate the large internal forces from the beams, so that the connections' failure under travelling fires might be overlooked. Further, due to the simplification of the 2D models in omitting the significant stiffness contribution from the slab and the adjacent structural components, the effect of the fire protection is likely to be amplified. This may give misleading information on the performance-based structural fire design under different travelling fire scenarios. Hence, the 3D model can be considered as feasible but also necessary for structural fire analysis for travelling fires as a complement to the simplified 2D model approach.

In response to the challenges prevailing in the international education of fire science for graduate students, and the core one is how to accurately and efficiently disseminate cutting-edge or fundamental international knowledge in the Far East, particularly in non-English-speaking countries or regions, the State Key Laboratory of Fire Science (SKLFS) at the University of Science and Technology of China (USTC) has established an English curriculum titled Introduction of Fire Dynamics with the researchers from University of Edinburgh, UK. This course gives an effective collaborative teaching methodology that fully considers the learning/teaching characteristics of domestic and international students at USTC by combining the strengths of fire safety education across the continents and is dedicated to bridging fire safety education gaps in two hemispheres, broadening the horizons of graduate students, enhancing their professional English level and developing the critical thinking skills. It has transformed its midterm examination by incorporating experimental demonstrations and theoretical explanations of its mechanism, which significantly inspired the students’ interests and passion in fire safety science, attracting extensive national official media reports from China News, People’s Daily Online, China Youth Daily, etc. The students from five other Chinese universities also attended this course online, which is unusual for an English course in a non-English-speaking country, so the course was called the “hottest” course at USTC. This paper will introduce this initiative and propose important references and experiences for education innovation in fire safety science for non-native English-speaking graduate students.

The paper compares the performance at elevated temperatures of three water based intumescent coatings (IC) exposed to constant heat flux in a cone calorimeter with the performance of a water-based IC which has been heated in a gas furnace according to the standard and the smouldering nominal heating curves, during a previous experimental program. The tests herein presented were carried out on steel plates, with different thickness to vary their section factors, protected with IC layer characterized by different dry film thickness. Despite the IC activated at about 120 °C regardless the heating conditions (i.e., under the cone or in the gas furnace), the type of heating affected the structure of the IC char that formed during the heat exposures: both the expansion of the IC and its equivalent thermal conductivity seems to be dependent on the fire exposure scenarios.

When developing a research roadmap for human behaviour in fires, it is necessary to identify areas that require additional research. A general overview – from a multidisciplinary perspective – of gaps in human behaviour in fires research across multiple contexts is missing. The goal of this paper was to perform a scoping review to identify research gaps and themes in all aspects of human behaviour in fires across contexts. This scoping review included 17 articles. In total, 37 research gaps and 11 research themes for the built environment and community context were identified. The main research gaps are related to cognitive factors, behavioural responses, environmental factors and physical/physiological factors. Also, for all research themes, additional research involving heterogenous populations is required. Furthermore, there is an imbalance in human behaviour in fires studies: most articles were focused on the built environment rather than the community context. Finally, the topic of intoxication has received limited research attention, and data collection methods lack diversity. Future research should not only be done from a multidisciplinary perspective but also interdisciplinary research efforts are required. The availability of more data and knowledge on human behaviour and responses in fires could be beneficial to simulation model developers/users, the general public and fire safety managers.