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15 March 2024, Volume 43 Issue 3 Previous Issue   

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Study on wood burning performance under different texture conditions Li Yinghui 2024, 43 (3):  287-291.  Abstract ( 151 )   In order to explore the flame burning characteristics of wood with different textures,5 kinds of wood were selected. The experimental device was set up. A total of 15 groups of experiments were designed in this experiment. From the aspects of mass loss rate, maximum flame height and combustion duration, the combustion characteristics of transverse, vertical and oblique textured wood were analyzed. The results showed that the mass loss rate of wood was related to texture. Texture had the least influence on the maximum flame height when pine was burning, and the greatest influence on Chinese fir. Furthermore, the burning duration of beech was longer than that of other four kinds of wood. Besides, the burning duration of Chinese fir was relatively short. The research results were helpful to better grasp the influence of texture on the flame characteristics of wood combustion. It provided theoretical support for material selection and fire prevention of wooden structure buildings. Related Articles | Metrics

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Experimental study of leaked hydrogen gas in two connected chambers under natural ventilation Hou Siyi, Liu Yang, Huang Zhongwei, Huang Yiming 2024, 43 (3):  292-298.  Abstract ( 87 )   A theoretical model is used to predict the hydrogen-air buoyancy jet generated by the slow leakage of hydrogen in two connected chambers with natural ventilation. The results show that when hydrogen leaks from one of the two connecting chambers, the relative position of the connecting port and the vent outside the leakage area has a greater impact on the hydrogen distribution. Increasing the distance between the central communication opening and the vents outside the leakage area, as well as increasing the vent area, can reduce density in the space and increase the location of high concentrations. The layering height and the change in leakage source height are positively correlated. The dispersion mechanism of hydrogen in naturally ventilated connected spaces is predicted in this study. From the perspective of hydrogen risk control, the locations where high concentrations occur are determined, and theoretical support for the safe operation of hydrogen storage equipment is better provided. Related Articles | Metrics

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Comparative research on effect of moisture on radiation thermal protective performance of fabric system for firefighter protective clothing Qiu Hao, Liu Fei, Wang Yunyi, 2024, 43 (3):  299-303.  Abstract ( 56 )   In the current evaluating thermal protective performance of firefighter protective clothing, the effect of moisture is ignored. Aiming to study the different impact of moisture in different fabric layers on thermal protective performance of fabric system, the different water contents were set in outer layer and comfort layer, experimental study with direct thermal exposure as well as with whole process of thermal exposure, heat storage and release were conducted under low-level radiant heat exposure condition. The results demonstrate that increasing moisture content of outer layer is beneficial for improving thermal protective performance of multi-layer fabric, in addition, with increasing moisture content, thermal protective performance is also the same, whether it is direct thermal exposure or considering the effect of heat storage and release. However, wetting comfort layer weakens thermal protective performance of fabric system, besides, the effective measures to improve thermal protective performance are to keep dry, increase moisture absorption and sweat releasing of comfort layer. When outer layer and comfort layer are simultaneously wetted, there is an interactive effect between the two, which can be deeply studied in the future. Related Articles | Metrics

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Effects of spray rate and obstacles on the characteristics of multi⁃side restricted flames Dou Pengliang, Huang Youbo 2024, 43 (3):  304-308.  Abstract ( 41 )   In order to study the horizontal jet flame morphology under multiple boundary constraints, a gas jet combustion experiment was conducted, with a jet rate of 1.04~6.25 m/s and a distance between the jet hole and the obstacle of 0.05, 0.10, 0.15, and 0.20 m. The flame diffusion behavior under different working conditions was studied, and the flame height was obtained based on image processing technology. The influence of jet rate and hole plate spacing on the characteristics of restricted horizontal jet flames was analyzed. The results show that as the injection rate increases and the hole plate spacing increases, the flame height decreases; When the injection rate is small and the hole plate spacing is large, flame diffusion is mainly controlled by buoyancy, and the flame does not fill the entire transverse area of the confined space. When the injection rate is high and the distance between holes and plates is small, the flame impacts the wall and spreads up and down along the impact point, resulting in a higher flame extension height. Establish a dimensionless prediction expression for flame height using non dimensional parameters such as coupled jet rate, hole plate spacing, and fire source power, making it suitable for calculating the height of a three side restricted horizontal jet fire. Related Articles | Metrics

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Research on fire characteristics of different curvature curved tunnels based on PyroSim Zhao Xiaokun, Ni Minghao 2024, 43 (3):  309-313.  Abstract ( 101 )   In order to explore the fire characteristics of curved tunnels and study the influence of curvature on the smoke spread of curved tunnel fires, the fire dynamics simulation software PyroSim was used to study the critical wind speed, temperature distribution, smoke spread law, and roof temperature attenuation law of curved tunnels with different curvatures. The results show that under the same fire source power and fire source location, the critical wind speed is positively correlated with tunnel curvature; Due to the special resistance along the wall, the propagation speed of high?temperature smoke inside the curved tunnel is faster, and as the duration of the fire increases, the difference in smoke propagation speed between the two sides of the tunnel increases; The temperature attenuation of the roof in a fire is positively correlated with curvature, and a prediction model for roof temperature attenuation with curvature of 0.6%, 0.5%, 0.3%, 0.25%, and 0.14% is provided. Related Articles | Metrics

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Discussion on fire protection design of new energy car storage based on real fire test Yin Liang, Zhang Liang, Liu Jiyang, Wang Zongcun, Lu Zhibao, Ye Jihong, Wei Ruichao, Chen Wei 2024, 43 (3):  314-319.  Abstract ( 96 )   The rapid development of new energy automobile industry puts forward new demand for fire protection design of automobile garage. In this article, cases of typical new energy car fires in buildings are analyzed, the first real fire test of new energy cars in storage is carried out, and measures for fire protection design of garages are discussed. The findings show that: the thermal runaway of the battery pack volatilizes gray combustible gases but the duration varies and explosive combustion is easy to occur in the garage. The thermal feedback from the inner wall of the garage is likely to accelerate the combustion of the car body, and the dura-tion of the strong combustion stage lasts for about 20% of the total combustion time. It is suggested that the fire prevention design of new energy automobile garage should focus on the detection of earlier signs of thermal runaway and the control of later combustion extent as well as the adoption of passive safety technology measures, and the garage should be installed with the recording device with sound pickup function and the separating elements with the fire-resistance rate not less than 2.00 h. Related Articles | Metrics

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Experimental study on the mechanical smoke exhaust effect of the operation depot of the vehicle base above subway Liu Moyun 2024, 43 (3):  320-325.  Abstract ( 37 )   Real-scale hot smoke experiments were conducted to study the smoke spread characteristics in an operation depot of subway vehicle base. The smoke propagation velocity, smoke temperature, and height of the smoke layer in the depot under different smoke exhaustion conditions were compared and analyzed. The smoke control and exhaustion effects of the mechanical smoke exhaust system has also been verified on site. The test results show that, in case of fire occurred in the depot, even if the mechanical smoke exhaust system activated and performed effectively, the smoke could not be completely confined within the smoke prevention zone where the fire started. The smoke would spread out from the original zone, cool down and descend in the area away from the fire source. Increasing the exhaust volume could decrease the propagation rate of smoke, but the smoke could not be confined completely within the fire smoke protection zone. Besides, increasing the exhaust volume has little effect on reducing the temperature of smoke layers. As shown in the tests, the smoke layer could be maintained at a relatively ideal height (about 7 m), when the mechanical smoke exhaust system was properly activated (the smoke exhaust volume was 44.8, 29.1 or 16.7 m3/（h.m2） , respectively). The smoke exhaust system could provide favorable conditions for occupant evacuation and fire rescue operation in the initial stage once a fire occurs in the subway operation depot. Related Articles | Metrics

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Study on the effect of gas explosion on other pipelines in the integrated water and gas pipeline corridor Cao Xinyang, Mi Hongfu, Zhang Haoliang, Shao Peng 2024, 43 (3):  326-333.  Abstract ( 30 )   In the case of "water and gas sharing" in the integrated pipeline corridor, if the gas pipeline leaks and causes the explosion, it may lead to the failure and damage of the water supply pipeline in the same tank. In order to study the influence of gas explosion on the same cabin pipeline, the method of methane-air mixed gas was defined by the nonlinear finite element program ANSYS/LS-DYNA, and the changes of strain, stress, vibration velocity and displacement of the same cabin pipeline under the action of gas explosion were studied through numerical simulation. According to the criterion of elliptic failure, the four influencing factors of pipe wall thickness, internal pressure, elastic modulus and yield strength were quantitatively analyzed. The results show that, under the action of gas explosion, the ovality of the same tank pipeline is negatively correlated with the wall thickness, internal pressure, elastic modulus and yield strength, and the yield strength has the least influence on the ovality of the same tank pipeline, all of which are lower than 3% of the critical dimensionless ovality. When the change rate of the influencing factors increases from 2.5% to 15%, the influence of wall thickness and elastic modulus on the ovality of the pipeline is higher, while the influence of internal pressure and yield strength on the ovality of the pipeline is lower. The research results can provide reference for the planning and design of the "water-air co-cabin" in the integrated pipeline corridor and the improvement of relevant norms. Related Articles | Metrics

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Simulation research on natural gas leakage explosion accident in masonry residential building based on FLACS Wang Jiangnan, Yao Yingkang, Dong Siling, Liu Shangxiao 2024, 43 (3):  334-339.  Abstract ( 55 )   Aiming at the structural characteristics of masonry residential buildings, taking the gas flash explosion accident in residential buildings in Wafangdian city as the research object, FLACS software was used to model explosive floor in 3D. Gas leakage and explosion were simulated considering injection direction, doors, windows, partitions and other factors. Results showed that, horizontal and vertical leakage have almost no impact on the volume fraction distribution of natural gas, with kitchen volume fraction higher due to hall partition obstructing effect; Room 504 explosion pressure increased sharply at the beginning of explosion, transmitted outward through doors and windows in arc form. Explosion pressure at 400 s was lower than 600 s, with pressure at 600 s explosion greater than brick wall failure pressure of 76 kPa causing structure damage. Research results provide theoretical guidance for accident inversion, stability evaluation of damaged structures and accident prevention. Related Articles | Metrics

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Risk analysis of fire disaster chain in elderly care facilities Chen Weijian, Li Runqiu, Zhou Yuanyuan 2024, 43 (3):  340-343.  Abstract ( 50 )   In order to study the impact of disaster factors and the nature of disaster carriers on fire risk prevention and control in elderly care facilities, disaster chain and complex network theory were applied to evaluate the risk degree of edges in the disaster chain network constructed based on complex networks and determine that the DEMATEL method can make the analysis results of complex networks more accurate. Statistical analysis of fires in elderly care facilities both domestically and internationally was conducted to identify the disaster causing factors in such accidents. A complex system disaster chain model was constructed using inductive analysis and the theory of chain transmission of disasters. The risk assessment of the constructed disaster network was conducted on the edges. Finally, the DEMATEL method was used to correct the errors in the risk assessment of disaster networks caused by factors such as different regions and times, improving the accuracy of disaster network risk assessment results. The study obtained the risk level of fire disasters in elderly care facilities, providing a basis for fire prevention and control in elderly care facilities, while also providing a basis for correcting complex network analysis results. Related Articles | Metrics

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Research on the temperature field of hydrogen energy vehicle tunnel fire under multiple operating conditions Liu Dong, Ye Jihong 2024, 43 (3):  344-349.  Abstract ( 56 )   This article takes the scenes of hydrogen energy vehicles releasing hydrogen in four different directions and immediately igniting it in a tunnel as the research objects. Fluent software is used to numerically simulate the temperature field generated after hydrogen is released and immediately ignited. The influence of hydrogen leakage direction and tunnel ventilation speed on the maximum temperature of jet flame and the distribution of high temperature zone is analyzed, providing scientific basis for the setting of ventilation speed in the tunnel and the fire prevention design of the inner walls of the tunnels. The results show that under these four working conditions, increasing the longitudinal ventilation speed of the tunnel has a limited effect on reducing the maximum temperature of the jet flame, but it can significantly reduce the volume of the high-temperature zone, thereby reducing the damage caused to the tunnel walls by the high-temperature zone of the jet flame. Therefore, in the tunnel design stage, it is recommended to increase the longitudinal ventilation speed of the tunnel appropriately, with the optimal ventilation speed of 5.0~8.0 m/s. It is also possible to consider adding an emergency lane on the far right side of the tunnel to increase the safe distance between the tunnel walls and vehicles, thereby protecting the tunnel structure and the safety of vehicle personnel. Related Articles | Metrics

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Study on the influence of mobile fan combination on smoke exhaust effect of building fire Zhao Rongxuan, Zhang Lin, Yang Shuanghong, Wang Wantong 2024, 43 (3):  350-355.  Abstract ( 46 )   This study aimed to investigate the impact of various combinations of positive pressure mobile fans (parallel, series, upper-lower-shaped, and V-shaped) on the effectiveness of smoke exhaust during building fires. By employing a combination of experimental measurement and numerical simulation using a large eddy simulation fire dynamics model, this research examines the application scenarios, smoke extraction efficiency, and necessary precautions associated with different combinations of fire smoke extraction. The results suggest that four different combinations of fans effectively achieve the desired airflow to cover the air inlet and increase indoor pressure. Specifically, when the fans are arranged in a V-shape, the air intake effect is superior compared to other configurations within the building. It should be noted that the proximity of the two air jets can lead to the formation of overlapping air cones between fans, particularly in the case of parallel-shaped and upper-lower-shaped fans. This overlapping can result in increased superposition of air vortices and energy consumption caused by certain air cones. This paper aims to examine the practical application of series-shaped positive pressure mobile fans, specifically addressing the issue of decreased flow rate caused by the obstruction of the rear airflow by the motor of the front fan. The objective is to verify the feasibility of employing this fan combination and establish a theoretical foundation for its use in smoke exhaust during fire incidents. Related Articles | Metrics

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Research on pedestrian evacuation in panic scenarios based on AnyLogic simulation Li Hua, Fan Shuaichao, Zhang Rumeng 2024, 43 (3):  356-361.  Abstract ( 49 )   In order to reflect the changing pattern of pedestrian evacuation in panic scenarios, simulation analysis was conducted based on the AnyLogic software. By introducing emotional factors and information factors, quantifying panic transmission coefficients and information transmission coefficients, establishing a group panic dynamics model, and using Monte Carlo methods for quantitative analysis of group psychology, the panic level is divided into five levels: Level I, Level II, Level III, Level IV, and Level V. This model is used to analyze the evacuation pattern of panic-stricken people under different densities and panic levels. The results show that panic has a low impact on evacuation efficiency under low-density scenarios, and moderate panic can reduce evacuation time under medium-and high-density scenarios. Exceeding the critical range can lead to a delay in evacuation. The scene simulation shows that under moderate panic, the evacuation of people is rapid and orderly, while under excessive panic, the evacuation of people is slow and chaotic. Related Articles | Metrics

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Discussion on pipe network layout of fixed fire extinguishing system in combustible liquid storage tank area Zhang Wang, Wang Yue, 2024, 43 (3):  362-368.  Abstract ( 32 )   In order to give full play to the role of the fixed fire extinguishing system, effectively shorten the fire extinguishing time, improve the fire extinguishing efficiency of flammable liquid tank fires, and reduce the threat of fire to the life safety of firefighters, this paper systematically investigated the layout of the fixed foam fire extinguishing system pipe network of domestic built fixed roof tanks and external floating roof tanks and the layout of the pipe network of the fire cooling water system, and analyzed the advantages and disadvantages of different layout methods, suggestions for the design and improvement of fixed fire extinguishing systems in combustible liquid storage tank areas have been proposed. Related Articles | Metrics

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Research on monitoring of gas cylinder microdeformation in metro gas fire extinguishing system Zheng Yi, Zou Xuecheng, Li Fumin 2024, 43 (3):  369-373.  Abstract ( 27 )   Some of the fire extinguishing gas cylinders available on the market have far exceeded the age limit, there are potential safety hazards and is easy to cause gas cylinder explosion accidents. Therefore, in order to ensure the safety of fire fighting cylinders, this paper develops the safe monitoring technology based on detecting the micro-deformation of such cylinders, which adopts the method of detecting the deformation by winding wire sensors on the surface of the cylinders. Through the cylinder bursting test, it is verified that the technology can effectively detect the micro-deformation of high-pressure cylinders, and the information can be transmitted to the centralized management of the big data platform by using Ethernet to realize the function of active supervision. Related Articles | Metrics

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Research on the protective performance of fire filter tools Zhao Xiang, Feng Xu, Zhao Jing, Zhang Ruoheng, Han Chong, Hu Cheng, Yu Dongxing, Song Wenqi, 2024, 43 (3):  374-377.  Abstract ( 26 )   In order to explore the protective performance of wet towels and filtering self-saving respirator under specific working conditions, a testing platform for the protective performance of filter tools was built. Seven materials, including hard polyurethane, soft polyurethane, paper, wood, cotton, PVC, and lithium batteries, were selected to test the main gas components in the combustion products, and the protective performance of ordinary towels against gas, smoke, and temperature was analyzed. The experimental results under specific operating conditions indicate that wet towels have a certain filtering effect on PM10 produced by 7 types of combustion materials, with an average filtering efficiency of 25.57%; It has a cooling effect on high-temperature flue gas, with an average decrease of 29.1 ℃; No significant filtration effect was observed for HCN and CO, with an average filtration efficiency of about 28% for C2H4O, 75% for SO2, and 84% for HCl; Considering the protective ability of the filtering self-saving respirator against CO and smoke, its performance is much better than wet towel, and has lower respiratory resistance. Related Articles | Metrics

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A lightweight fire detection model integrating attention mechanism Cao Kangzhuang, Jiao Shuangjian 2024, 43 (3):  378-383.  Abstract ( 50 )   Based on visual information, fire detection is of great significance to fire protection work. However, most of the methods proposed by relevant research institutions at this stage are based on high-performance hardware devices, which limits the practical deployment and application of relevant results. In response to this, this paper uses ShuffleNetv2 network as the main backbone to construct a lightweight model based on YOLOv5 target detection model, and introduces the SIoU loss function to improve the positioning accuracy of the model's target box. Additionally, the Shuffle Attention module is added to the model to improve its recognition accuracy of flame targets in complex environments. Experiments have shown that compared to the original YOLOv5 model, the improved model not only achieves better recognition results but also reduces the parameter count by 54.2% and improves detection speed by 40.5%. Finally, the model is deployed to embedded devices to verify its application efficiency, and the results show that while maintaining recognition performance, the model achieves a detection speed of 32 f/s. Related Articles | Metrics

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Research on multiband flame detection method based on red UV photoelectric sensors Xue Ying, Zhao Zhipeng, Liu Jianxiang, Li Shaopeng 2024, 43 (3):  384-388.  Abstract ( 32 )   In response to the requirements of flame detection in different fire scenarios, this study establishes a fire detection model with fire characteristics and investigates the mechanisms of multi-band red and ultraviolet (UV) sensors for flame detection, multi-feature data fusion algorithms, and fire decision-making methods. Ultraviolet photodetectors in the wavelength range of 185 to 260 nanometers and infrared photodetectors in the wavelengths of 3.6, 4.4， 4.8 μm are selected for flame detection, and flame characteristic signal data information is collected. By employing multi-signal data fusion and feature parameter correlation algorithms, a mathematical model for fire detection based on multi-band fire characteristics is established. Fire occurrence scenarios are simulated to train the optimal configuration of relevant feature parameters. The research results demonstrate that multi-band flame detection using UV light in the range of 185 to 260 nanometers and infrared light at wavelengths of 3.6, 4.4, 4.8 μm can meet the requirements of the national standard GB 15631-2008， Special fire detectors. The recognition and decision-making capabilities for flames are improved, and there were no false alarms or missed detections in the experiments. Related Articles | Metrics

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Flame retardancy and thermal protection performance of multi-layer film fabric for high-level chemical protective clothing Wang Junsheng, Jin Xing, Zhang Jie, Shang Ke, 2024, 43 (3):  389-392.  Abstract ( 21 )   The multi-layer film fabric for high-level chemical protective clothing was trial-produced using aramid fabric, polyester filament fabric and acrylic fabric as the skeleton layer, polyolefin film as the forming layer, and polyhalogenated olefin film as the barrier layer. The effect of fabric, polyolefin masterbatch and flame retardant types on mechanical property, flame retardancy, combustion behavior and thermal protection performance of the multi-layer film fabrics were investigated by electronic fabric strength machine, limit oxygen index meter, cone calorimeter and thermal protection performance tester. The results show that multi-layer film fabrics with aramid fabric and polyester filament fabric as skeleton layer have better mechanical properties. A higher flame retardancy can be achieved for the multi-layer film fabrics made from B/C-type polyolefin masterbatch and Y-type flame retardant. The multi-layer film fabrics with acrylic fabric as the skeleton layer has lower heat release and higher carbon residue, but its thermal protection performance is poor due to severe melting phenomenon during the testing process. In summary, the multi-layer film fabric trial produced with aramid fabric as the skeleton layer, polyolefin film prepared by C-type masterbatch and Y-type flame retardant as the forming layer, has the best comprehensive performance. Related Articles | Metrics

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Study on the influence of core layer thickness on combustion characteristics of polyethylene⁃based aluminum composite panel Wang Jiabin, Zheng Yuchao, Cui Yu, Liu Guolei 2024, 43 (3):  393-397.  Abstract ( 35 )   The combustion characteristics of polyethylene-based aluminum composite panels with different core layer thicknesses were studied by using cone calorimeter. Four heat fluxes of 35, 50, 65, and 80 kW/m2 were selected to obtain the ignition characteristics, fire risk, and smoke toxicity. The results showed that polyethylene-based aluminum composite panels conform to the ignition law of thermal thin materials, and the derived critical ignition heat fluxes of 3, 4, 5 mm thick core layers are 33.9, 25.1, 9.9 kW/m2, respectively. With the increase of heat flux, the heat release rate of aluminum composite panels of each thickness increases obviously, and the heat release rate tends to double peak. With the increase in heat flux and core layer thickness, there was a rapid decrease in the Fire Performance Index (FPI) from 41 to 0.14, accompanied by a rapid increase in the Fire Growth Index (FGI) from 0.02 to 3.19, and the CO release rate also rapidly increases, resulting in a significant increase in fire hazard. Related Articles | Metrics

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Study on the mechanism of multiple combustible gas explosion suppression by phosphorus-nitrogen series explosion suppressant in coal spontaneous combustion environment Zhang Shulin, Wen Zhuo, Lu Yi, Yang Mingrui 2024, 43 (3):  398-404.  Abstract ( 52 )   Uses the CHEMKIN software to establish a kinetic model of the chemical reaction of the explosion of methane/ethylene/hydrogen multiple combustible gases suppressed by phosphorus-nitrogen series explosion suppressants, including ammonium dihydrogen phosphate (ABC) and melamine cyanurate (MCA), and conducts numerical simulation calculations. The model includes the kinetics model of the chemical reaction of multiple combustible gas combustion and the kinetics model of the thermal decomposition of phosphorus-nitrogen series explosion suppressants, with a total of 61 components and 259 elementary reactions. According to the simulation calculation, the mole fraction changes of each key component of the multiple combustible gas, the temperature changes at the reaction equilibrium, the mole fraction changes of hydrogen free radicals and hydroxyl free radicals, and the changes of temperature sensitivity coefficients were obtained to explore the key explosion suppression components and analyze their reaction pathways. This reveals the explosion suppression mechanism of the explosion suppressant. The results show that both ABC and MCA have good explosion suppression effects on multiple combustible gases, and the explosion suppression effect increases with the increase of ABC and MCA proportions, and the explosion suppression effect of ABC is better than MCA. Both explosion suppressants can achieve explosion suppression by promoting the combination of H radicals and OH radicals to form more stable H2O. The main explosion suppression mechanism of ABC is the formation of the HOPO and PO2 forming 2HOPO?PO2 suppression cycle, consuming a large amount of H radicals and OH radicals to produce more stable H2O, and cutting off chain reactions to suppress explosions. The main explosion suppression mechanism of MCA is that HNCO consumes H radicals and OH radicals to produce H2O and cut off chain reactions to suppress explosions. Related Articles | Metrics

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Layered double hydroxide/functionalized carbon nanotube in situ composite structure based synergistic flame retardant for epoxy resin Dai Li, Liu Hengjun, Guo Yilin, Yang Qi 2024, 43 (3):  405-411.  Abstract ( 37 )   Epoxy resin （EP） is widely used as structural material on aircrafts. Exploring and designing high-performance flame retardants for EP is critical to the fire safety of civil aviation. In this study, nanosheets of MgAl layered double hydroxide （MgAl-LDH） were grown on the skeleton of interlaced functionalized CNTs （F-CNTs） to construct an in-situ composite structure of MgAl-LDH/F-CNTs. Then the MgAl-LDH/F-CNTs composite structure was used as a mechanical support to further accommodate CuMoO4 nanoparticles to obtain the synergistic flame retardant of MgAl-LDH/F-CNTs-CuMoO4. The built MgAl-LDH/F-CNTs in-situ composite structure can realize the uniform distribution of the flame retarding components （LDH nanosheets, functionalized carbon nanotubes and CuMoO4 nanoparticles） in the polymer substrate. Compared with pure epoxy resin without flame retarding treatment, the peak heat release rate of EP@MgAl-LDH/F-CNTs-CuMoO4 in the combustion test can be reduced by 40.5%, the total heat release can be lowered by 7.49%, the CO production and total smoke release can be respectively decreased by 43.0% and 26.3%, and the limiting oxygen index can be increased by 38.2%. It can be seen that the flame retarding performance of EP composite with flame retardant treatment is significantly improved. In addition, the tensile and bending strengths are decreased by only 7.1% and 22.4%, indicating that the addition of F-CNTs and the construction of MgAl-LDH/F-CNTs composite structure can effectively compensate for the deteriorating effect of inorganic flame retardants on the mechanical strength of EP. Related Articles | Metrics

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Study on preparation and combustion performance of an inorganic composite polystyrene board Wang Pengyu, Si Guangxu, Liang Qinggang, Zhou Liang 2024, 43 (3):  412-418.  Abstract ( 29 )   The characteristics of hazardous of chemical disasters and accidents was analyzed. Combined with years of practical command experience, the key points of practical disposal were analyzed from three stages of initial battle, stalemate and decisive battle, and explore from two aspects of organizational command and grasping key points. By analyzing a large number of practical cases, the calculation and estimation of fire extinguishing agents were explained, and a new practical perspective was taken to explore methods for handling hazardous chemical accidents. Related Articles | Metrics

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Implications of New Zealand's forest fire history research for fire management in China's southwestern forest areas Hong Ruicheng, Wang Jin, Wang Qiuhua, Xing Fuji 2024, 43 (3):  419-422.  Abstract ( 42 )   In order to comprehensively understand the current situation and frontier dynamics of research in tunnel fires in China, 2 406 relevant papers were searched from 2001-2021 in the database of CNKI, and the bibliometric analysis was conducted with the help of CiteSpace software, and the knowledge map was drawn. The results show that: the number of research papers in the field of tunnel fires shows an overall growth trend, and the process can be divided into three stages; the cooperation between authors is relatively close, forming a certain network structure; fire scenario simulation technology is a good tool to explore the smoke distribution and temperature distribution in the field; highway tunnels are the main place for road tunnels research, and high-altitude tunnel fires are a recent research topic; smoke exhaust, ventilation, temperature analysis and personnel rescue of tunnel fires are hot topics in the field, and we will continue to analyze and research around the above hot topics in the future. Related Articles | Metrics

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Reflection on the disposal of hazardous chemical accidents Zhu Feiyong 2024, 43 (3):  423-426.  Abstract ( 82 )   The characteristics of hazardous of chemical disasters and accidents was analyzed. Combined with years of practical command experience, the key points of practical disposal were analyzed from three stages of initial battle, stalemate and decisive battle, and explore from two aspects of organizational command and grasping key points. By analyzing a large number of practical cases, the calculation and estimation of fire extinguishing agents were explained, and a new practical perspective was taken to explore methods for handling hazardous chemical accidents. Related Articles | Metrics

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Bibliometric analysis of tunnel fire in China based on CNKI Cai Jingjing, Li Xin, Yang Fuqiang 2024, 43 (3):  427-432.  Abstract ( 80 )   In order to comprehensively understand the current situation and frontier dynamics of research in tunnel fires in China, 2 406 relevant papers were searched from 2001-2021 in the database of CNKI, and the bibliometric analysis was conducted with the help of CiteSpace software, and the knowledge map was drawn. The results show that: the number of research papers in the field of tunnel fires shows an overall growth trend, and the process can be divided into three stages; the cooperation between authors is relatively close, forming a certain network structure; fire scenario simulation technology is a good tool to explore the smoke distribution and temperature distribution in the field; highway tunnels are the main place for road tunnels research, and high-altitude tunnel fires are a recent research topic; smoke exhaust, ventilation, temperature analysis and personnel rescue of tunnel fires are hot topics in the field, and we will continue to analyze and research around the above hot topics in the future. Related Articles | Metrics