Fire Technology最新文献

In the present paper, pinewood samples with varied thicknesses incorporating different additives, including fish gelatine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), triphenylphosphine (TPP), diammonium phosphate ((NH₄)₂HPO₄) and sodium carbonate (Na₂CO₃) were investigated by using a cone calorimeter. The measured parameters included ignition time, mass loss rates (MLR), heat release rates (HRR) and yields of selected gaseous species. The results demonstrated that as the sample thickness increased, the deformation to the tested specimens were less pronounced. The treated samples with a thickness of 13 mm exhibited intermediate properties to those of thermally thin and thermally thick materials. For samples with higher thickness, the second peak HRR was noticeably lower than the first. At a median heat flux of 50 kWm⁻², the treated samples exhibited a prolonged burning duration, possibly owing to the presence of flame-retardant additives. However, for the sample with thickness of 30 mm, this effect was only nominal. The yields of CO₂ remained nearly constant across varying heat fluxes for both untreated and treated samples, indicating that the extent of the oxidation reactions is not influenced by the imposed heat flux. The results from present study, which primarily focused on flammability behaviours of pinewood with varied thicknesses warrants, further investigations with a view to deciphering the underlying mechanistic pathways of thermal degradation and flammability of the tested samples.

The traditional tunnel fire retardant coating has low strength and poor durability, which will cause damage and cracks due to the pre-disaster of tunnel fire and reduce the fire resistance. To overcome these defects, this study developed a heat-insulating and fire-resistant cementitious composite with excellent mechanical properties by using expanded perlite, silica aerogel, and basalt fiber, and named it PABC (perlite-aerogel-basalt-cement) mortar. The effect of PABC mortar on the temperature field of tunnel lining was tested by fire test, and its influence on the fire resistance of tunnel structure under the RABT heating curve was evaluated by finite element simulation. The results show that PABC mortar has good thermal insulation, and the temperature of the bottom steel bar is reduced from 474 to 148 ℃ in the fire test. PABC mortar can significantly improve the fire resistance of the tunnel structure and can reduce the bearing capacity reduction rate of the tunnel structure under the RABT fire heating curve from 47.8% to 11.5%. However, due to the size effect and heating conditions, PABC mortar exhibits different spalling behaviors in box-type resistance furnace tests and open flame tests, indicating that its spalling resistance requires further improvement.

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.