Water spray remains the most effective, environment-friendly and economical way of fighting accidental or unwanted fires, and this is largely due to its thermal characteristics. The mechanism of fire suppression by sprinkler water sprays is influenced by numerous factors, which have been the focus of years’-long and on-going research studies to improve its extinguishing performances. A comprehensive review study was carried out in this study to assess the level of technological know-how and current state of research in the field. A total of 2473 published articles spanning 50 years (i.e. 1970–2020) were systematically collected and analysed, whereby more than 100 relevant articles were selected and integrated in the discussion. In particular, the review focuses on research relating to the interactions of sprinkler sprays with flame, fire plume and hot surfaces, aiming to provide a better understanding of the phenomena involved in fire suppression.

A systematic approach was used to investigate the weathering-induced degradation of a common water–based intumescent coating. In this study, the coatings are intended for humid indoor applications on steel substrates. The coating contains ammonium polyphosphate, pentaerythritol, melamine, and polyvinyl acetate. By replacing each ingredient with a less water-soluble substance, the most vulnerable substances, polyvinyl acetate and pentaerythritol, were identified. Furthermore, the weathering resistance of the system was improved by exchanging the ingredients. The coatings were stressed by artificial weathering tests and evaluated by fire tests. Thermogravimetry and Fourier-transform infrared spectroscopy were used to study the thermal decomposition. This study lays the foundation for the development of a new generation of water-based intumescent coatings.

CIB correlations for compartment burning rates and average gas temperatures are examined for accuracy, utility, and generality. The results are applied to modeling the fire on 9/11 in WTC 1. Specific information is used from the NIST investigation. It is demonstrated that simple heat transfer modeling can predict the truss steel rod temperatures for the E119 tests of WTC done by NIST. The CIB temperature correlation and steel truss modeling are used to predict burning conditions for the WTC 1 96th floor fire and compared to the NIST results. Here a consideration of fuel loads from 20 to 40 kg/m2 was considered compared to just 20 used by NIST. The results suggest that the fully insulated truss bar temperatures would achieve higher values for higher fuel loads. A critical steel truss temperature of 650°C could support failure of the trusses as a theory for the collapse of the towers.

The ability of EfficientDet, a framework developed in 2019 for object detection, to automatically detect smoke plumes at a distance of several kilometers is demonstrated. Recent articles have raise...

Firefighting bunker gear is manufactured from flame-retardant materials, which resist ignition and delay flame spread. However, concerns have been emerging on the potential harmful effects of some flame retardants (FRs) commonly used in flame-retarding materials, particularly the brominated flame retardants. This study investigated the presence of flame retardants in bunker gear, particularly polybrominated diphenyl ethers and their congeners in the garments, and evaluated their impact on thermal performance. X-ray fluorescence spectroscopy was used to ascertain the presence of bromine as a possible indicator for brominated flame retardants. X-ray fluorescence results indicated the presence of Br in all samples, ranging from 444 to 20,367 µg/g. Further analysis via gas chromatography–mass spectrometry was done on samples. Brominated flame retardants, particularly polybrominated diphenyl ethers and hexabromocyclododecane, were detected in all samples with concentrations ranging from 261.61 to 1001.77 µg/g and 0.01 to 0.07 µg/g, respectively. The cone calorimeter was used, with 50 and 75 kW/m2 heat fluxes, to investigate the impact of the brominated flame-retardant concentrations, if any, on thermal performance. New bunker garments, particularly those with lower Br and brominated flame-retardant concentrations, were observed to have higher thermal performance.

The effect of different cable layouts on the fire behavior of electric cable arrays was experimentally studied. The influence of external heat flux on cable fire characteristics was investigated. Several parameters for electrical cables such as the post-burning morphology, ignition time, heat release rate, peak heat release rate and total heat release were obtained. The results show that cable layouts could affect cable charring degrees according to the post-burning morphology. A linear relationship was found in the transformed form of time to ignition and radiant heat flux, and the critical radiant heat flux value for the single cable array appeared smaller than that for the other two layouts. The peak heat release rate for Cables A–D with the single array presents the increasing trend with an increase in radiant heat flux, while the two parallel and intersectional cable arrays present the different trends. Moreover, the total heat release values of Cables A–D in the different cable layouts were analyzed. This work provides the basic data and preliminary investigation to fire engineering of cable arrays with the different layouts.

This review aims to present recent improvements and existing challenges in the design of wearable sensors used in the firefighters’ protective clothing. Wearable sensors are generally used directly on the body or placed on wearable items to monitor data for the safety of firefighters. Recently, wearable sensors have attracted much attention from researchers and experts. Most investigations have addressed novel designs for wearable sensors to enhance firefighters’ safety measures and reduce the risk of exposure to fires. This article is an attempt to review design limitations of wearable sensors for future developments and improve existing shortcomings. The growing body of knowledge focused on the application of wearable technology to monitor firefighters’ activity, health, and body temperature. In the following, we have discussed the trials of the design of the existing sensors. Finally, moisture and radiation as common exterior parameters in fire events are discussed which received less attention and have major impact on the performance of firefighters’ wearable sensors.

Oriented strand board is a widely used construction material responsible for a substantial portion of the fire load of many buildings. To accurately model oriented strand board fire response, kinetics and thermodynamics of its thermal decomposition and combustion were carefully characterized using milligram-scale testing in part I of this study. In the current work, Controlled Atmosphere Pyrolysis Apparatus II tests were performed on representative gram-sized oriented strand board samples at a range of radiant heat fluxes. An automated inverse analysis of the sample temperature data obtained in these tests was employed to determine the thermal conductivities of the undecomposed oriented strand board and condensed-phase products of its decomposition. A complete pyrolysis model was formulated for this material and used to predict the mass loss rates measured in the Controlled Atmosphere Pyrolysis Apparatus II experiments. These mass loss rate profiles were predicted well with the exception of the second mass loss rate peak observed at 65 kW m−2 of radiant heat flux, which was underpredicted. To further validate the model, cone calorimeter tests were performed on oriented strand board at 25 and 50 kW m−2 of radiant heat flux. The results of these tests, including both mass loss rate and heat release rate profiles, were predicted reasonably well by the model.

This study proposes a new reduced-size plate thermometer with a modified shape and improved insulation performance in order to resolve problems commonly found when using conventional plate thermometers to measure incident heat flux in fire environments, for example, a low spatial resolution caused by the large plate area and a non-uniform temperature distribution on the plate. The main results of this study showed that the new plate thermometer exhibits high spatial temperature uniformity, and that the plate thermometer can be reduced in size to 30 mm. Moreover, it was found that the relative error of the incident heat flux of the plate thermometer was substantially reduced compared to that of a heat flux meter using a conduction correction factor expressed as a third-order polynomial function of heat flux, rather than using an average empirical constant calculated from measurement over a wide range of heat fluxes. Finally, it was confirmed that the incident heat flux measured by the new reduced-size plate thermometer in a heptane pool fire was in good agreement with the heat flux meter measurements during the rapid-fire growth, fully developed and decay phases of a fire.

Artificial turf structures are increasingly used in closed areas and have to comply with the European fire standard for building products (EN ISO 13501-1). The main test to evaluate the fire performance of flooring products is the EN ISO 9239-1 radiant panel test. The test principle is to determine the critical heat flux of floorings exposed to a forced ignition and a specific heat flux profile. As large amounts of material are needed to perform the test, the development of a radiant panel test at reduced scale was considered. The experimental design methodology was implemented to mimic the heat flux profile. The fire performance of artificial turf structures was evaluated at both scales and the results were compared. The burnt lengths of the specimens and thus the critical heat flux are similar for both scales. Thus, the downscaled device could advantageously be used for high throughput development of artificial turf structures.

A novel simple-shield thermocouple that is capable of radiation correction in fire environments and that has a simpler structure and greater convenience than conventional aspirated thermocouples was proposed. The measurement errors of bare-bead, double-shield aspirated, and simple-shield thermocouples were then compared in a simulated fire environment. In addition, a fire experiment using wood cribs was performed in order to verify the measurement performance of the proposed simple-shield thermocouple in a real fire environment using a one-third-scale ISO 9705 room. The simple-shield thermocouple produced fairly accurate temperatures that fell within 5% of the actual gas temperature in the simulated fire environment. In addition, variations in the surface emissivity and the installation angle of the simple-shield thermocouple in the real fire environment further reduced the measurement error. With a radiant heat flux of 20 kW/m2, it was confirmed that the bare-bead thermocouple had a relative measurement error of up to 80% compared to the aspirated thermocouple, while the proposed simple-shield thermocouple was capable of measuring the temperature within a relative error of around 15% compared to the aspirated thermocouple.

Oriented strand board is a widely used construction material responsible for a substantial portion of the fire load of many buildings. To accurately model the response of oriented strand board to fire, thermogravimetric analysis, differential scanning calorimetry, and microscale combustion calorimetry tests were carried out to construct a thermal decomposition model using a numerical solver, ThermaKin, and a hill climbing optimization algorithm. The model included a single-step water vaporization reaction and four consecutive reactions representing thermal decomposition of organic constituents of oriented strand board. The experiments and modeling revealed that the first two of the four reactions are endothermic, while the last two are exothermic. The net heat of decomposition was found to be near zero. The heat capacities of condensed-phase species and heats of combustion of evolved gases were also determined. The heats of combustion were found to vary over the course of decomposition—the trend captured by the model. Development of a complete pyrolysis model for this material will be a subject of Part II of this work.

This study presents the fire performance of typical components of wood structure buildings. The wooden beams and floor slabs, quite common in wood structure buildings, were burned with different fire exposure times by a pool fire source. Then, the surface temperature evolution and the charring rate were recorded and analyzed. The results show that the flashover and re-ignition phenomenon occurred in all wood materials under the burning pool fires. The glulam beam cross-section was U-shaped, and the maximum charring rates of glulam beam, cross-laminated timber floor, and cross-laminated timber partition board were 0.833 mm/min, 1.538 mm/min, and 0.435 mm/min, respectively. It can be seen that the combustion behavior time of specimens with different cross-section thicknesses is different. If the thickness of the specimens is appropriately increased, their combustion behavior time can be significantly improved.

The aim of this work is to study and characterize the fire behavior of vertically oriented spruce wood panels using experiments conducted at the scales of cone calorimeter and single burning item t...

Wood dust consists of the fine particles of wood that are produced when wood is processed. It is considered explosive, especially if it produces a dust cloud. Initiating the combustion process insi...

This study investigated the fire risk properties of cypress wood for the construction of interiors, especially focusing on heat and smoke hazard properties in fire scenarios. Fire risk characteristics were measured using a cone calorimeter (ISO 5660-1). The external heat flux was maintained at 50 kW/m2. The flame retardants used were metal oxide and metal silicate; they were mixed with a water glass solution. Flame retardants and the silicon compound were dispersed in a concentration of 20 wt% versus 80 wt%, respectively, during 24 h using a magnetic stirrer. The fire performance indexes of the specimens increased by 3–16 times, compared with uncoated specimen and the fire growth index of the specimens increased by 70%–92%. The smoke performance index of the specimens increased by 9–66 times, compared with uncoated specimens. The smoke risk as shown by the smoke performance index increased in the following order: SnO < mica < Co3O4 < ZrSiO4 < cypress. The smoke growth index decreased from 93% to 98%, compared with uncoated wood. The smoke risk due to smoke growth index increased in the following order: SnO < mica < ZrSiO4≈ Co3O4 < cypress. The smoke intensity decreased from a minimum of 85% to a maximum of 99%, compared with uncoated wood. The concentration of CO gas generated after combustion was decreased by 24%–67%. They increased in the following order: mica ≈ ZrSiO4 < SnO < Co3O4 < cypress. A comprehensive assessment of fire performance shows that flame retardants decreased heat hazards, smoke hazards, and CO toxicity.

Cooking oil fires present a reasonable worst-case hazard when considering thermal radiation to occupants close to a kitchen hob/cooktop. Shallow or deep frying, the activity frequency and the oil volume may contribute to the risk. A review of cooking oil use is presented via consumer purchasing habits, studies on the health effects of cooking with oil and statistics related to the disposal of cooking oil waste. An online survey provides further data on current cooking practices. Olive oil, vegetable oil or pure sunflower appear to be the most common types. Results suggest that cooking on a hob occurs 4 times per month for deep frying and 17 times per month for shallow frying. A design value of 250 mL is advocated for all frying activities with a frequency of 11 times per month. Design volumes of 2.5 L and 150 mL are proposed for deep and shallow frying, respectively.

This article addresses the development of a bench-scale test (jetfire lab) mimicking the fire exposure of the large-scale jetfire facility. An experimental approach was addressed to develop direct correlation and to validate the similitude between bench-scale test and large-scale jetfire. Comparisons were made by testing Zaltex passive fire protection material in the form of panels. Novel setups were designed to make the jetfire lab able to measure time/temperature curves similar to those obtained at a large scale. The assembly of the tested samples was also investigated. An experimental protocol was elaborated to consider the junction between parts of the sample at the reduced scale. Direct correlation was found between the large and the bench scale and it was evidenced that jetfire lab can be used for preliminary study and development of new thermal barriers for fire protection.

In using thin fire blankets to protect structures in wildfires, heat rejections by radiation (reflection and emission) are essential for good performance. By varying the radiative properties of the front and back surfaces of the blankets, this article offers an optimization study of several scenarios of incident heat flux including pure convection, pure radiation, and combinations of the two. Two types of blanket heat-blocking efficiencies are studied in the optimization scheme. An overall efficiency is defined as the amount of incident heat blocked to the total amount of incident heat in specified wildfire scenarios. An instantaneous heat-blocking efficiency is defined as the instantaneous heat flux blocked to the instantaneous incident total heat flux which provides good understanding of the physics of heat-blocking mechanisms of fire blanket under quasi-steady conditions. In addition to maximizing these heat-blocking efficiencies, there are other optimization objectives, including the minimization of the blanket backside temperature. A genetic algorithm is used for the multi-objective optimization schemes. For the transient heat incidence, the optimization for the entire time sequence is performed with the possibility of a change of blanket radiative properties during the fire sequence, accounting for changes to the fire-facing surface caused by the incident heat.