Fire Extinguishing Research Articles

Development Directions of Fire-Fighting Equipment Using Aircraft Engines Abroad

In the last century, outstanding fire-fighting technology developments have occurred in Hungary. Mobile, quickly deployable, efficient, environmentally friendly tools and technologies with optimal fire extinguishing material use have come to the fore. This included equipment using exhaust gas from internal combustion engines and combustion products from aircraft engines for fire-fighting. The developers’ goal is to reduce environmental and secondary damage during fire-fighting, and at the same time, they sought to increase the efficiency of fire-fighting processes by using measurably less fire-fighting material. In our article, we present the foreign developments of fire-extinguishing equipment that uses aircraft engines with a unique operating principle and is suitable for applying multiple types of fire-extinguishing materials, thus also for implementing complex fire-fighting. We review the design and construction of the equipment, their operating principle, examine their practical application possibilities, and present directions for future development.

Analysis of forest fire dangers of the Bryansk region in the zones of radioactive contamination and beyond

The purpose of the study is to analyze the forest fire dangers of the Bryansk region forests, taking into account their radioactive contamination and potential risks for forestry workers involved in forest fires extinguishing. Significant areas of radioactive contamination of forests with a predominance of sites belonging to the classes of high and very high natural fire danger, restrictions on economic activity and a long fire-hazardous period contribute to the occurrence of radioactive forest fires. The analysis of the combined data on forest fires and radioactive contamination of forest areas showed that most forest fires occur outside the zones of radioactive contamination and are not radioactive. The largest number of fires occurs at the beginning of the fire season. Radioactive forest fires in most cases arise from the burning of dry grassy vegetation, as a result of the transition from lands of other categories and through the fault of the population. The average effective dose of additional radiation per a workday can be estimated at 1.96 μSv, and the maximum at ~ 15.4 μSv. Most fires are extinguished in the early stages and do not have time to cover large areas. It indicates the effective work of the forest fire service

Effect of nano-aluminum hydroxide on the liquid phase properties and fire-fighting foam performance of the mixed surfactants solution

Short-chain fluorocarbon surfactants show synergistic effects with hydrocarbon surfactants in foaming and foam stability. Nano-aluminum hydroxide (nano-ATH) was added as an additive to the short-chain fluorocarbon surfactant mixture solution, which was found to increase the surface tension and viscosity of the surfactant mixture solution, and decrease the foaming properties of the solution, as measured by Wilhelmy method, Waring Blender method and viscometer. By measuring zeta potential experiments, surfactant molecules were found to be adsorbed on nano-ATH through charge gravity, which increased the desorption energy of nano-ATH. Measuring the visco-elastic modulus of the solution by rheometer, it was found that nano-ATH increased the visco-elastic modulus of the surfactant mixture solution, which improved the foam's resistance to the external disturbances. Observed by the image analysis system on the foam, the uniform distribution of nano-ATH in the liquid film reduced the coarsening and coalescence speed of foam .Through the self-developed oil resistance test, nano-ATH enhanced the oil resistance stability and inhibition of fuel vapour diffusion of the foam by about 12%; through self-developed foam fire extinguishing and anti-burning tests, nano-ATH shortened the fire extinguishing time of the two-phase foam by 25%, and showed better fire extinguishing and anti-burning performance than the foam.

Inhalation Burn from a Fire Extinguisher: A Rare Cause of Acute Phosphate Toxicity

Inhalation Burn from a Fire Extinguisher: A Rare Cause of Acute Phosphate Toxicity

Critical radius deviated from Leidenfrost state of droplets on liquid layer

The levitation of Leidenfrost droplets on liquid pool is fascinating, but its final stage is lack of understanding. Here, we found that a droplet levitated on liquid layer eventually deviated from Leidenfrost state once its radius was lower than a critical radius due to evaporation. The critical radius of ethanol droplet deviated from Leidenfrost state on silicone oils with a thickness ranging from 2.0 to 15.0 mm was determined by experiment. The influences of the initial radius of droplet, viscosity, and thickness of liquid layer on critical radius were analyzed. In addition, the critical radius decreases with increase in superheat for ΔT lower than 25.0 °C, whereas it does not significantly vary after ΔT exceeding 25.0 °C. The bottom temperature Tb of droplet does not approach to saturation temperature even under a high superheat. The experiment found that Marangoni convection existed inside droplet. Based on a theoretical model considering Marangoni convection, the reason for droplet deviated from Leidenfrost state was explained. These findings are helpful for understanding the final state of Leidenfrost droplet on liquid layer and would provide a potential practical application such as extinction of oil pool fires with liquids.

On gravity-driven liquid nitrogen jets reach and horizontal spread for extinction of ground fires by aerial means

This paper describes experimental and numerical results on the reach and the spread of gravity-driven jets of liquid nitrogen (LN2) on the ground for applications to fire extinction by aerial means. A series of experiments released LN2 jets from different elevations in ambient air to measure their reach and spread distances upon the impingement. A numerical model was developed to simulate the behavior of such jets. Upon validation, the numerical model was used to further predict the LN2 pool mass and spreading distances under various release configurations. Results showed that the LN2 survivability is greatly affected by the release height of the cryogen, since the LN2 quantity reaching the ground decreases as the release height increases. Moreover, releasing larger initial LN2 quantities and, most importantly using larger nozzle diameters, both the LN2 pool mass and spreading diameter can be extended. Additional experiments were conducted where cryogen jets were released onto small (∼300 cm2) alcohol pool fires; results showed that only limited quantities of the LN2 evaporated in transit to the fire, and small amounts of the cryogen expediently snuffed the fires. A simplified model also suggested that in fire supression/extinction by LN2 the fuel cooling mechanism is of secondary importance compared to the mechanism of separating the fuel from oxygen.

Research on the mechanism and extinguishing technology of substation fire

This article utilizes the combustion characteristics of combustible materials to investigate the fire mechanisms and extinguishing technologies in substations. Experimental and simulation analyses have revealed patterns in heat release rates, flame heights, flame temperatures, flame resistance, and particulate ash. A modular solution employing a novel hot aerosol fire suppression system has been introduced. This system integrates independently manufactured alarm devices, initiation devices, sensors, and fire suppression equipment, offering either semi-automatic or fully automatic functionality. It serves both targeted fire suppression and complete immersion scenarios. By developing an integrated fire suppression and database alert system, enhanced intelligent fire protection has been attained, thereby advancing the sophistication of substation fire safety and the digitization of power networks.

Study on cooling efficiency and mechanism of lithium-ion battery thermal runaway inhibition by additives enhanced water mist based on boiling heat transfer theory

In recent years, fire and explosion accidents caused by thermal runaway (TR) of lithium-ion batteries (LIB) have occurred frequently, which has become one of the main obstacles restricting its development. Therefore, it is urgent to develop fire extinguishing agents with high cooling efficiency to inhibit the growth of TR. The water mist is an effective choice, but it shows poor performance with the rise in cell temperature under TR. In this study, two additives, KCl and the nonionic fluorocarbon surfactant FC-4430, were added to the water mist to improve the cooling efficiency. In addition, the inhibition effect exerted by the modified water mist during the whole process of lithium-ion battery TR was experimentally investigated. Furthermore, the influence of water mist with additives on the Leidenfrost effect in the high temperature range was deduced, and the reinforcement cooling mechanism was analyzed by heat transfer theory. The results show that KCl and FC-4430 can increase the initial cooling rate in the high temperature range by 48.6%–120%. The reinforcement mechanism is attributed to changing the medium's physical parameters with additives. On the one hand, the Leidenfrost point of the droplets on the cell surface is increased, which in turn extends the temperature range of the nucleate boiling stage, and on the other hand, the heat flux density and heat transfer of the water mist in the film boiling state are increased.

Optimization Analysis of Water Supply Mode for Fire Protection System of Super High Rise Building

Abstract In order to improve the applicability and reliability of the fire water supply capacity of super high-rise buildings, the fluid analysis software Flomaster was used for simulation. Through the existing pumps, valves, pipelines, pressure reducing valves and newly developed fire hydrants and other components, the fire water supply system of super high-rise buildings is modeled. The pressure distribution of the system pipe network under a given fire water supply mode is studied. The research shows that the simulation can analyze whether there is excessive pressure in the fire hydrant system under different flow conditions in the actual fire extinguishing process. This paper simulates the actual fire extinguishing process of the fire hydrant system through a specific engineering case. The pressure distribution and flow distribution under different flow conditions are obtained. The excessive pressure position of the fire pipe network system under the given fire pump model is obtained. It provides a method for guiding the selection of fire pump and the design of fire hydrant system pipe network. It has certain guiding significance for the subsequent optimization of the design scheme of the fire water supply network and the prediction of the performance of the R&D equipment.

Wall Follower Based Fire Extinguisher Wheeled Robot Prototype using 5 Channel Fire Sensor

Fires can occur anywhere, be it in schools, offices, and housing or other open spaces. Fire cannot be predicted when it will happen. In the modern era robots are one of the very special technologies, the benefits of these robots can facilitate human work. Robot cars in this era are attracting quite a lot of attention from experts to develop. Therefore, the author designed a "Wall Follower-based Fire Extinguishing Robot using a 5 Channel fire sensor" to reduce the risk of fire. This robot uses the HC-SR04 sensor to detect the barrier wall so that the extinguishing robot reaches the fire point. For the microcontroller tool used in this design system in the form of an Arduino Nano microcontroller which functions as part of the 5 Channel Flame Sensor controller to detect hotspots and a DC water pump to extinguish the fire. In this study using experimental research. This robot has successfully passed the track and put out the fire as the author has designed. The average flame sensor on this robot can read the fire point at a distance of 20 cm with angles of 90°, 60°, 120°, 150°, then the output voltage generated on the DC motor with a PWM value of 191 or 75% duty cycle produces an output of 8.77V measured using a multimeter, and this robot can extinguish the fire on the track with different distances with an average fire extinguishing time of 7.1 seconds.

Enhanced rheology and firefighting performance of fluorine-free soft foams through the assembly of cellulose nanofibres and cellulose nanocrystals at the air–liquid interface

In this work, we developed soft and highly stable perfluorocarbon-free foams based on cellulose nanofibres (CNFs), cellulose nanocrystals (CNCs) and alkyl polyglycoside (APG). Neither the CNCs nor the CNFs can effectively stabilise the APG foam, which is reflected in the spontaneous degradation of the foam. Interestingly, blending these two nanocelluloses and foaming resulted in an ultrastable foam. The reflective optical interference technique was used to visualise liquid flow in the liquid film, and the results showed that the foam film with a thickness of only a few tens of nanometres gained excellent mechanical stability by tuning the assembly of CNCs and CNFs at the air–liquid interface. Moreover, the interfibril interactions at the Plateau borders reduce the bubble coarsening rate and drainage rate. In pool fire extinguishing tests, increasing the total concentration of CNCs and CNFs improved the foam stability, but increasing the viscosity led to a decrease in the foam spreading rate. Thus, a formulation with 0.4 % nanocellulose has poorer firefighting performance than a formulation with 0.15 % nanocellulose. When the ratios of CNCs and CNFs are properly controlled, the burnback performance of perfluorocarbon-free foam is better than that of state-of-the-art fluorinated AFFFs for n-heptane pool fires. The sustainability of the firefighting process is considerably improved by switching to the nonperfluorinated liquid foam developed in this work.

МОДЕЛЮВАННЯ ВОГНЕЗАХИСТУ СВІТЛОПРОЗОРИХ ФАСАДНИХ КОНСТРУКЦІЙ З ВЛАШТУВАННЯМ ЗРОШУВАЧІВ

The popularity of translucent materials in construction, especially in high-rise buildings, creates challenges for improving approaches to fire safety. Translucent designs have a limited. During a fire, they can quickly heat up, crack or even collapse, which helps the fire to spread to other parts of the building and increases the speed of fire spread. Practical methods and methods of limiting the spread of fire on building facades are considered in the work, including the use of fire eaves, protective screens made of fire-resistant material, limiting the area of the window opening, as well as the use of water irrigation. Water irrigation is an effective method of extinguishing fire and cooling facade elements, but its parameters, such as working pressure, water flow, location, etc., require careful research to achieve maximum efficiency. The purpose of this work is to use the PyroSim software complex to investigate the effectiveness of sprinklers for the protection of transparent structures on the facade of high-rise buildings and to determine their main parameters. With the help of PyroSim, a detailed three-dimensional model was created, which takes into account the complex geometric shapes of the building and the impact of fire protection systems, taking into account the features of translucent facades. In the course of research, structural elements that can affect the spread of fire and smoke are also taken into account, namely the characteristics of materials, fire load, installation of window openings. PyroSim, simulating the spread of a fire, made it possible to take into account heat and smoke flows, convective effects occurring during a fire, as well as the interaction of sprinklers with the heat load. The results of such modeling can be used to optimize the design of fire protection systems and ensure the compliance of building regulations with fire safety issues. In particular, modeling allows you to determine the most effective ways to place sprinklers, taking into account the specific conditions and structural features of the building. Thanks to this, it is possible not only to increase the level of protection of buildings against fires, but also to minimize the costs of installing and maintaining fire systems.

Влияние жизнестойкости на психологическую безопасность пожарных-спасателей

Introduction. The professional activity of a firefighter is inseparable from psychological states associated with risks and challenges. Performing the tasks of extinguishing fires, eliminating emergency situations and man-made disasters, firefighters act in a team. Their hardiness, the ability to use adaptive strategies in difficult situations, the skill of constructive interpersonal interaction depends on their psychological safety. The aim of the study is to examine firefighters' resilience and its contribution to psychological safety. Materials and methods. The following methods were used: The Hardiness Survey (S. Muddy), The Security Questionnaire (Ch. Kong and L. Ahn), The Portrait Values Questionnaire (Sh. Schwartz). The study on the basis of IPSA GPSA of the Ministry of Emergency Situations of Russia involved firefighters studying in the master's programme in the direction of “Fire Safety”. Methods of mathematical data processing (descriptive statistics, Spearman rank correlation, regression analysis) were implemented in IBM SPSS Statistics 26 package. Results. The mean scores of resilience, personal psychological safety of firefighters were above the normative values. Significant correlations were found between psychological safety and resilience of firefighters, and involvement as a component of resilience is a predictor of psychological safety with the dominance of values of caring for people and nature. Conclusion. Firefighters' willingness to take risks, sense of confidence and control, and engagement enable adaptive, resilient coping mechanisms. Firefighters' higher sense of psychological safety reflects their ability to better cope with stress, make informed decisions, work effectively as a team, and maintain their psychological well-being in high-risk and highresponsibility environments. Job involvement and commitment to the values of the profession enhance their sense of psychological safety in a teamwork environment and confidence in control. It is important for leaders of fire and rescue organisations to understand the psychological benefits based on resilience and firefighters' sense of psychological safety and to employ practices to develop them.

Specific Technologies of Aviation Rescue and Firefighting Operations over the Years

The twentieth century was a period of rapid development in aviation. It was a time of great progress in the construction of aircraft, the development of ground infrastructure and the improvement of qualifications of aviation personnel. Over the years, aviation has gone from cruise flights in simple aircraft to transatlantic flights, complex aircraft with hundreds of passengers on board. Military aviation can operate at speeds exceeding the speed of sound and in all weather conditions. The infrastructure of large airports has reached the size of cities. Over the past century, the development of aviation has been followed by changes in the organization and equipment of rescue and fire-fighting services. The public does not accept the loss of human life or large-scale material damage and environmental damage. In the search for effective extinguishing agents and methods of administering them, people began to look for ways other than field fire services. Specialized firefighting units have appeared at airports, which are designed for specific rescue and firefighting operations on aircraft and infrastructure. For many years, attempts have been made to select special rescue and firefighting technologies capable of improving the effectiveness and safety of operations. Quite quickly, the car was chosen as the means of transport for airport rescue services. But over time, the need was recognized for it to have different characteristics and equipment than a vehicle for village and town safety units. As a result of various experiments, unusual technical solutions designed to solve basic problems specific to airports were developed. Equally interesting was the path to determining the best fire extinguishing agents and their means of administration. From hand-held fire extinguishers to remote-controlled cannons administering thousands of liters or kilograms of extinguishing agents over a long distance. The publication provides information on the history and development of basic firefighting technologies specific to aviation and some pointers to the future.

Sustainable Material Approach to Safer Fire Extinguishers

: The world considers environmental concerns a top-notch priority and strictly finds ecofriendly ways to bring transformations. The widely used class of fire extinguishers, halons, has been extensively used for decades until they were acknowledged for producing hazardous components like HF, HCl, HBr, and COF2 and causing ozone depletion. This creates a surge in the search for a competent substitute with reduced toxins, easing the environmental burden. So, this review discusses the significance of halons, their existence, phase-out, and alternate substitutes in detail. To reduce ozone depletion potential and global warming potential, the Montreal Protocol announced a ban on halons and promoted the search for its replacements by either introducing the use of HFCs and perfluorocarbons having zero ODP, or modifying them by gelling them with dry powders, gelling agents, surfactants, and antiflatulents. The thorough composition of gelled halocarbons proposed as efficient fire extinguishant alternatives is also disclosed here.

Research and application on modeling and landing point prediction technology for water jet trajectory of fire trucks under large-scale scenarios

To let water jets land at the fire, pitch angle of the fire monitor has to be adjusted manually with successive rounds, which seriously affects the efficiency of fire extinguishing. To improve the efficiency, this paper proposes a technology for water jet trajectory modeling and landing point prediction to help with extinguishing automatically. Considering fragmentation and atomization of water jets, trajectories are analyzed and the predicted trajectory is closer to the real situation. Secondly, a compensation method for the prediction is proposed to further reduce the deviation between the predicted and the actual landing point, taking into account the combined effects of high altitude, initial jet velocity, and wind. On this basis, considering the difficulty of directly solving the analytical solution to the target initial pitch angle of the jets, a searching method is also proposed, which greatly improves the solving efficiency. Finally, through practical experiments and verification, the proposed model takes an average time of 0.00292 s, which is far less compared with other methods. The prediction error is improved by at least 45.3%, and the average deviation is less than 2 m.

Study on multi-field coupling characteristics of underground coal combustion and nitrogen injection parameter optimization

Underground coal fires, which are widely distributed and cause serious resource waste and environmental hazards, have become a common concern of the international community. This paper aims to reveal the mechanism of coal spontaneous combustion and the expansion law of underground coal fires. A void rate model from the goaf to the ground surface and a multi-field coupling model for underground coal fires were established. Based on which, the combustion process from the beginning of oxidation to the formation of large-scale fire of the remaining coal in goaf was analyzed. Furthermore, the evolution law of underground coal fire after nitrogen injection and the influence of different nitrogen injection parameters were analyzed. The results show that the coal spontaneous combustion can be divided into three stages: slow reaction stage (stage Ⅰ), violent combustion stage (stage Ⅱ), and stable combustion stage (stage Ⅲ), and the transformation of different stages is mainly controlled by the oxidation reaction rate of coal. To obtain the optimal parameters for nitrogen injection for fire suppression, the fire extinguishing efficiency concerning nitrogen injection time, nitrogen injection amount and nitrogen injection position, as well as the distribution law of nitrogen in rock strata were analyzed. Through range analysis, it is determined that the most effective fire extinguishing occurs with the injection rate of 0.15 m3/s in stage I, and the injection position has little influence on the fire extinguishing effect. This understanding contributes to a deeper understanding of the multi-field coupling mechanism of underground coal fires and provides a guidance for extinguishing and preventing underground coal fires.

Rational design of the temperature-responsive nonflammable electrolyte for safe lithium-ion batteries

The development of nonflammable electrolytes is critical for breaking the trade-off between the safety and energy density in Li-ion batteries (LIBs). Here, a rational design strategy of temperature-responsive nonflammable electrolytes (TRNEs) is proposed which are capable to prevent the heat accumulation and extinguish the fire efficiently during thermal runaway. Compared to the conventional phosphate- or halogen-based flame retardants, the TRNE based on low-cost and multifunctional methylurea (MU) was demonstrated with the lowest volatility (11.6 % weight loss) below 250 °C, and the highest efficacy to extinguish the fire at >210.4 °C through heat absorption, inert gases generation and char layer formation. In addition, the developed MU-based TRNEs enable higher stability and rate capability of LIBs compared to various nonflammable electrolytes. A Li||LiFePO4 (LFP) cell employing MU-based TRNE achieved higher stability (94.9 % capacity retention for 1500 cycles) than commercial electrolyte. A Ni-rich Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) system was demonstrated with superior rate capability and high stability for 700 cycles (2.72 months) with the capacity retention of 89.9 %. Combining low cost and volatility, as well as high stability, rate capability and fire extinguishing efficacy, we demonstrate a promising design strategy to improve the battery safety for high-energy-density LIBs.

FIRE DETECTION USING AI

Fires are one of the biggest challenges in the world right now, due to the global warming that the planet is currently suffering from. We all know what fires are and what they are capable of causing great damage, whether to humans, animals, or other forms of life. Fires spreading increasingly around the world due to increasing global warming, it has become imperative to develop an intelligent system that detects fires early, using modern technology. Therefore, we used one of the artificial intelligence techniques, which is machine learning, which is one of the popular methods now. Professionals have done a lot of research, experiments, and coding software to detect fires using machine learning. Image processing is a type of processing in which the input image is transformed into another image as output with certain techniques applied to it. In this concept, we will create a fire detecting device using a USB or system camera and a application and apply the concepts of IoT and Image Processing to get real time fire detection results. When the device is switched on, it continuously monitors the area Infront of camera for fires. This is done by using HAAR Cascade Classifier Algorithm. Once detected the system could be hooked up with either fire extinguishers to make them work independently or it could just set an alarm or send a notification to the users mobile device via GSM. The after processing possibilities are endless.

Analysis of Innovation Trends in Energy Storage Safety Technology based on Patent Data

Against the backdrop of energy transition and the large-scale development of renewable energy, the significance of energy storage technology has become increasingly prominent. Based on the data of invention patents, this paper analyzes the innovation situation of global energy storage safety technology, providing a reference basis for future patent research and industrial planning in the field of energy storage safety. Through the global and Chinese patent application volumes, the research comparatively analyzes the application situations of the main source countries and main applicants of patents, and analyzes the innovation situation of energy storage safety technology by combining research methods such as technical structure comparison and value degree comparison. The study finds that global energy storage safety innovation is in a relatively active period. China takes the leading position in the total amount of patent applications, but the proportion of patents with high value is low, and it still lags behind South Korea and the United States. Currently, the main research directions in this field worldwide mainly include battery monitoring and status monitoring, battery protection, fire detection and alarm, fire extinguishing systems, and battery pack structure design.