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15 October 2021, Volume 40 Issue 10 Previous Issue    Next Issue

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Research method of bursting panels strain based on LabVIEW MA Chao-xin, LIU Xiu-mei, LI Wei, LIU Li-li, 2021, 40 (10):  1419-1422.  Abstract ( 1635 )   In order to study the strain of the bursting panels during dust explosion, realize full intelligent control and acquisition, a strain research method of the bursting panels based on LabVIEW is designed. The method uses Wheatstone bridge to convert the stress change of the strain gauge arranged on the bursting panels into electrical signal. At the same time, the work of the infrared camera, high-speed camera and pressure sensor is synchronized through the LabVIEW software, data acquisition card, etc., so as to realize the comparative analysis of the explosion pressure in the tank, the strain value of the blasting panels and the image of the blasting panels at that time during the explosion. The experimental results show that the method meets the experimental requirements of synchronization, diversity, accuracy, etc. It has the characteristics of high degree of modularization, strong real-time performance, and good scalability, which is helpful to improve the structure of the bursting panels. Related Articles | Metrics

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Research on oil leakage hazard of FPSO upper module LUO Zheng-shan, CAO Lu-ping, WANG Xiao-wan, ZHANG Xin-sheng 2021, 40 (10):  1423-1427.  Abstract ( 1595 )   In order to study the disaster caused by oil leakage from the upper module of Floating production, storage and unloading device(FPSO), the oil vapor diffusion model and the pool fire model were established to quantitatively study the damage law and damage range of oil vapor explosion and pool fire. Taking the oil leakage of a FPSO heating skid as an example, the results show that the oil vapor concentration is the largest at the source of the leakage, and there is a risk of explosion and pool fire when the vapor mass concentration is 0.23 kg/m3. At the same time, with the increase of the leakage time, the smaller the horizontal distance from the target to the center of the pool, the faster the thermal radiation flux will rise. The harm of vapor cloud explosion impact is greater. Related Articles | Metrics

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Explosion characteristics of gasoline fog and low concentration methane mixture CHEN Qu-fei, YANG Yi-tian, YU Jun, SHU Xue-ming 2021, 40 (10):  1428-1431.  Abstract ( 1590 )   In order to study the influence of a small amount of gasoline liquid vapor on the explosion characteristics of low-concentration methane, a 20 L spherical explosion vessel was applied to study the explosion characteristics of 1 mL and 2 mL gasoline liquid that mixed with air alone. With varying methane concentration, the explosion characteristics of low-concentration methane mixed with 1 mL and 2 mL gasoline were studied. The effect of gasoline addition on the lower explosion limit of the entire system was analyzed. The results indicate that gasoline has a very significant impact on the explosion of methane-air mixture. When the addition amount is 2, 2.5 and 3 mL, the pmax is 0.11, 0.79 and 0.82 MPa, respectively, and the corresponding (dp/dt)max is 10.57, 32.52 and 108.53 MPa/s, respectively. When the methane concentration is 6% and the gasoline addition amount is 2 mL, the pmax is 1.01 MPa, which is 31% higher than when 1 mL gasoline is added, and 320% higher than that when no gasoline is added. The lower explosion limit of the gas mixture become lower than the lower explosion limit of each in the air. The mixture of 1 mL gasoline and air is not explosible, while it can explode when mixed with methane with a concentration of ≥3.5%. When 2 mL gasoline is mixed with methane whose volume concentration is ≥0.3%, the gas mixture can still explode. This work can provide data support for the explosion and prevention of leaking gas and other flammable liquid vapor mixtures in enclosed and semi-enclosed spaces. Related Articles | Metrics

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Law of water curtain to restrain oil and gas leakage and explosion propagation REN Shao-yun, XIA Deng-you 2021, 40 (10):  1432-1437.  Abstract ( 1585 )   Numerical simulation method is used to study the suppression law of oil-gas leakage diffusion and explosion with water curtain in open space. When the oil-gas leaks from 5 000 m3 oil tank at the rate of 0.25 m/s for 600 s, the concentration at 4 m away from the leakage source is kept at 1.6%, exceeding the lower explosion limit. When the water curtain is sprayed for 80 s, the concentration of oil and gas in the area behind the water curtain is lower than 1/2 of the lower explosion limit. When the water curtain is sprayed for 250 s, only the oil and gas around the leakage source reaches the lower explosion limit. When there is no water curtain, the peak value of overpressure is 10.2 kPa and the peak value of temperature is 2 360 K. After adding water curtain, the peak value of overpressure decreased to 2.8 kPa, and the peak value of temperature decreased to 1 813 K. When the number of water curtain is 1, 2, 3 and 4, the peak values of overpressure are 2.8, 1.42, 1.3 and 1.1 kPa respectively, and the peak values of temperature are 1 813, 1 210, 993 and 382 K respectively. When the number of water curtain is 4, the effect of restraining high temperature peak is obvious. This paper can provide a theoretical reference for the prevention and disposal of oil-gas leakage and explosion accidents in the field of petrochemical production. Related Articles | Metrics

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Study on stratified stability of smoke in tunnel under the action of opposite jet and shaft CHEN Sheng-yuan, YANG Yong-bin, ZHANG Xuan 2021, 40 (10):  1438-1442.  Abstract ( 1579 )   Through the similar test, the relationship between the smoke stratification stability of highway tunnel fire and the power of fire source, the wind speed of opposite jet and the position of measuring point under the synergistic action of opposite jet and shaft was studied. Three kinds of 50 working conditions were designed, and the stratification stability of fire smoke at different locations under different working conditions was analyzed. The test results showed that the smaller the upstream and downstream wind speed difference is, the more stable the fire smoke stratification is, and the larger the upstream and downstream wind speed difference is, the more disordered the fire smoke layer is. When the wind speed of the opposite jet is the same, the power of the fire source has no obvious effect on the stratification stability of the fire smoke. Due to the interaction among thermal buoyancy, jet and shaft suction force, the stratification stability of fire smoke at different locations is different. Related Articles | Metrics

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Effect of heating rate on the co-pyrolysis characteristics of paint thinners and plastics HE Fen-fen, LIN Qing-wen, LIU Ling, YUE Hai-ling 2021, 40 (10):  1443-1446.  Abstract ( 1593 )   To study the change of co-pyrolysis characteristics of paint thinner and PET plastic at different heating rates，a simultaneous thermal analyzer was used to measure the weight loss (TG) and enthalpy change (DSC) of paint thinner and PET plastic during co-pyrolysis at different heating rates (10, 20, 30 K/min). The Coats-Redfern method was used to analyze the thermal dynamics of the samples. The influence of heating rate on the co-pyrolysis behavior of paint thinner and PET plastic was investigated. The results show that the pyrolysis process of the sample has obvious hysteresis in nitrogen atmosphere. There is only one major weightlessness stage in the pyrolysis process of paint thinner and PET plastic, and there are two major weightlessness stages in the pyrolysis process of mixture. The pyrolysis activation energy of paint thinner and PET plastic decreaesproceed with the increase of heating rate. The pyrolysis reaction of the mixture is inhibited when the heating rate is lower than 30 K/min, and the pyrolysis reaction is the most complete when the heating rate is lower than 30 K/min. The final sample residual amount is 8.4%, and the fire risk is high. Related Articles | Metrics

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Study on the smoke exhaust scheme of the tunnel fire in the metro section longer than 20 km ZHENG Xiang, HE Guan-hong, NONG Xing-zhong, XU Zhi-sheng 2021, 40 (10):  1447-1450.  Abstract ( 1637 )   Aiming at the smoke exhaust scheme of the tunnel fire in the metro section longer than 20 km, based on the Guangzhou Metro Line 18 project, the numerical simulation is used to analyze the temperature below the tunnel vaults and the flow velocity in the tunnel under the smoke extraction scheme when subway trains stop at different positions in the section. The result shows that the smoke extraction scheme can control the temperature in the tunnel well, and the flow velocity in the tunnel also meets the requirements of greater than 2 m/s and less than 11 m/s in the specification. The research result provides a guarantee for the safe operation of the tunnel and provides a scientific reference for related projects . Related Articles | Metrics

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Research on the spacing of fire evacuation doors in slow-moving road tunnel ZOU Qi, ZHANG Li-sha, JIANG Xue-peng, PU Ting 2021, 40 (10):  1451-1454.  Abstract ( 1641 )   In the event of fire with evacuation channel in slow moving road tunnel, the existing specifications do not specify clear requirements for the distance between evacuation doors. Taking Chunxuan Road Tunnel as an engineering example, in case of a slow-moving road fire, the required evacuation time and the available evacuation time are compared to determine the evacuation safety and the effectiveness of the evacuation door spacing. The results showed that in the event of a fire on a slow-moving road, a fire separation wall of 2 hours and Class A fire door could separate the slow-moving road and the car lane into two fire compartments and use the car lane as a safety zone. There were refugees before and after the fire source, and people could not bypass the fire source. Ventilation and smoke evacuation are not performed during ventilation to prevent smoke from accumulating at the opposite side and jeopardizing the safety of pedestrians. Smoke spreads freely. When the distance between the evacuation doors is 250 m and the fire source is facing the evacuation door, the safety evacuation requirements are not met. For that distances of 200 m and 150 m, it meets the requirements for safe evacuation. considering safety and operating costs comprehensively, it is recommended to set the evacuation doors for slow moving roads at 200 m intervals. Related Articles | Metrics

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Study on fire resistance of earthquake damaged reinforced concrete plane frame structure CHEN Quan-jie, CHEN Wei, LIU Hong, WEN BO 2021, 40 (10):  1455-1461.  Abstract ( 1541 )   In order to clarify the influence of geometric damage of concrete frame structure caused by earthquake on the degradation law of fire resistance after earthquake, the seismic damage data and seismic test records are analyzed and summarized. The spalling and residual deformation of concrete protective layer are taken as the seismic damage form of concrete structure, and the damage size is determined by data statistics and regression analysis. Thus, the finite element model of two-story and two span earthquake damaged reinforced concrete plane frame is established, and the deformation characteristics of frame structure and the effects of fire position, axial compression ratio and story displacement angle on the fire resistance of plane frame structure are obtained. Related Articles | Metrics

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Study on ejected flame extension characteristics of facade fires under ambient wind ZHUANG Rui, WANG Pu, HE Qing, TANG Fei 2021, 40 (10):  1462-1465.  Abstract ( 1610 )   Building facade ejected fire behavior characteristics is one of the important research orientations in fire research, particularly the ejected flame of facade fire is related to the fire hazard of adjacent buildings under the effect of cross wind. Based on Froude similarity theory, through the fire experiments by employing a reduced-scale fire compartment, this paper studied the ejected flame expansion characteristic under different cross wind speeds, heat release rates and opening size. The influence of wind speed on flame shape is analyzed, and a new subsection prediction model for the ejected flame length with different compartment openings and HRRs is proposed, providing references for fire protection design of building facade. Related Articles | Metrics

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Comparative study on two fire smoke exhaust modes of underground pedestrian passage JIA Bo-yan, ZHANG Ji-dong, ZHANG Guo-wei, ZHANG Peng 2021, 40 (10):  1466-1469.  Abstract ( 1647 )   A combination of theory and FDS numerical simulation is used to study the control effects of the semi-transverse smoke exhaust ventilation mode and the longitudinal smoke exhaust ventilation mode on the spread of fire smoke when a fire (1.5 MW) occurs in the underground pedestrian passage. Results have shown that under the condition of equal smoke exhaust volume and different air supply volume, except for the temperature directly above the fire source exceeding 60 ℃, the other semi-transverse smoke exhaust ventilation mode controls fire smoke hazards within the critical index, which is beneficial to escape on both sides of the fire source for pedestrians. The longitudinal smoke exhaust ventilation mode controls the risk factors of fire smoke within the critical index, and most of the smoke is controlled on the downwind side of the fire source, which is beneficial for pedestrians to escape on the windward side. For underground pedestrian passage fire, from the perspective of high personnel escape efficiency, the semi-transverse smoke exhaust ventilation mode should be adopted; from the perspective that pedestrians are affected by the uncertainty of risk factors, the longitudinal smoke exhaust ventilation mode should be adopted. Related Articles | Metrics

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Study on ventilation and exhaust strategy of oil tank truck fire in slope tunnel with central smoke extraction system WANG Hui-qiang, MENG Hong-ping, WEN Li-jun, JIANG Ji-ji 2021, 40 (10):  1470-1474.  Abstract ( 1582 )   The smoke spreading distance, visibility at 2 m height and smoke exhaust efficiency of the system are taken as the key criteria to determine the reasonable cross-section air supply area. FDS is used to simulate the fire scene of oil tank truck in 1%, 3%, 5% and 7% slope tunnels. The results show that: When the slope is less than 5%, the proportion of cross-section air supply area increases with the increase of slope; When the slope is more than 5%, the proportion of cross-section air supply area remains at 80%. According to the numerical relationship between the proportion of cross-section air supply area and tunnel slope, the model of non-dimensional cross-section air supply area slope correction coefficient is proposed. Related Articles | Metrics

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Evacuation path planning of toxic gas leakage in chemical industrial park based on Floyd algorithm ZHANG Di, MAO Zhan-li, GONG Mei-ling, REN Jian-xing 2021, 40 (10):  1475-1478.  Abstract ( 1573 )   In this paper, evacuation path planning of toxic gas leakage in chemical industrial park based on Floyd algorithm is proposed. Gauss smoke mass model is used to simulate the dynamic diffusion process of toxic gas in the atmosphere after the accident. Under the condition of ensuring the safety of evacuation route, Floyd algorithm is used to calculate the optimal evacuation path. This paper presents a set of optimization scheme of evacuation route selection for liquid ammonia leakage accident in chemical industrial park. The case study shows that the model is scientific and reasonable and can provide the optimal evacuation path for most buildings in the chemical industrial park. Related Articles | Metrics

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Prediction of remaining life of pipeline based on KPCA-FA-ELM model ZHANG Gang 2021, 40 (10):  1479-1483.  Abstract ( 1519 )   Aiming at the prediction of the remaining life of pipelines, this study proposes a prediction method based on the KPCA-FA-ELM combined model. The construction method of the remaining life prediction model of the corroded pipeline and the performance verification method of the prediction model are studied. Take oilfield reinjection pipelines and oil and gas gathering pipelines as examples to verify the pipeline remaining life prediction method proposed in this research. The research shows that the minimum relative error of the KPCA-FA-ELM model proposed by this research is 0.38%, the maximum relative error is 6.1%, and the average relative error is 2.35% in the process of predicting the remaining life of oilfield water injection pipelines. The root square error is 0.207, and the Hill inequality coefficient is 0.011. In the process of predicting the remaining life of oil and gas gathering and transportation pipelines, the evaluation indicators are smaller than other models. Therefore, the performance of this model is better than other common prediction models. Related Articles | Metrics

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Research on fire control capability evaluation of a complex mini fire station GU Shao-fei 2021, 40 (10):  1484-1488.  Abstract ( 1675 )   Mini fire station plays a positive and important role in the prevention and control of fire accidents and the protection of urban people's lives and properties. The three-dimensional fire safety system can be established and become an important way to improve the city's fire defense ability through the reasonable management and use of mini fire station. This paper takes a complex mini fire station in Shanghai as an example, the evaluation of the firefighting ability of the city complex mini fire station is carried out, and the fuzzy comprehensive evaluation model of the firefighting ability of the mini fire station is established. It has very important practical significance for fire station construction. Related Articles | Metrics

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Mechanism research on fire inhibition using water spraying device installed on LNG tank vehicles ZHOU Dan, YE Cheng, ZHANG Bo-jun, WANG Zhi-rong 2021, 40 (10):  1489-1493.  Abstract ( 1528 )   : Taking LNG tank vehicle operation box as research object, by buliding unsteady numerical model of watermist inhibiting combustion after leakage in confined space, effects and mechanisms of different nozzle heights, intervals and spraying angle on fire inhibition were studied. The results showed that with the increase of nozzle height, intervals and spraying angle, the relative humidity in the control cabinet first increases and then decreases. The higher the nozzle height, the faster the initial rise rate of evaporation rate and average humidity, the higher the peak value of evaporation rate, and faster the decline rate after reaching the peak value. Reasonable arrangement of water spraying device can significantly accelerate the flow rate of the flow field, uniform flow field distribution, prevent leakage gas accumulation, increase average humidity, and prevent fire and explosion. Related Articles | Metrics

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Research and development of intelligent drying and rewinding equipment for fire hoses FENG Yi-ran , LEI Xiao-jing, TAO Xue-heng, JIN Zhi-yuan 2021, 40 (10):  1494-1496.  Abstract ( 1764 )   Against the low degree of intelligence of drying and rewinding equipment for fire hoses, and in order to improve the combat efficiency of firefighters and reduce energy consumption, the overall structure of intelligent drying equipment for fire hose is determined and model analysis is carried out to verify the reliability of the structure, and through temperature, humidity and other detection sensors, automatic monitoring of the internal environment of the whole equipment is achieved, temperature and humidity are automatically adjusted. The machine is capable of automatically rewinding the fire hose into a tray, so that the entire drying and rewinding process of fire hose can be completed by one key operation, realising the automation of the technology and equipment and the intelligence of some functions, improving the technical level of the equipment and the value of the product, and effectively reducing the labour intensity of fire fighters. The equipment can provide technical support for the future development of an integrated cleaning and drying machine. Related Articles | Metrics

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Study on the measures to reduce the nozzle temperature of aerosol fire extinguishing agent ZHAO Yu, HUANG Yin-sheng, TANG Chao 2021, 40 (10):  1497-1500.  Abstract ( 1690 )   In order to study the high temperature problem of aerosol fire extinguishing agent in the process of practical application, the method of comparative test was used. By adding cooling material KHCO3 to the aerosol fire extinguishing agent, and adding heat insulation material, the test was carried out on the nozzle temperature. The results showed that the combustion temperature of aerosol fire extinguishing agent decreases obviously when the addition of KHCO3 is 2%. The light magnesium carbonate selected in the experiment has good cooling effect and short fire extinguishing time. When the thickness of pearl rock wool is 20 cm, the effect is the best, and the highest temperature of the nozzle is 63 ℃. It provides theoretical reference and technical support for reducing the nozzle temperature of aerosol fire extinguishing agent. Related Articles | Metrics

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Development and analysis of fire fighting robot HUANG Xiao-long, GUO Yi-ran, GAO Yang-zhen, HUANG Min 2021, 40 (10):  1501-1504.  Abstract ( 1861 )   This paper mainly introduces the research of fire fighting robot at home and abroad in recent years, analyzes the key technical points of its moving carrier and control device, on-board equipment and driving mode, looks forward to the future development trend of fire fighting robot, and puts forward the main technical problems and suggestions in this field, provides the basis for intelligent fire fighting and reconnaissance technology. Related Articles | Metrics

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Study on temperature-sensitive cell coat composite with biomass-containing LI Jing-shan, ZUO Qiu-ling, LIU Bing-hui, LIU Yun 2021, 40 (10):  1505-1507.  Abstract ( 1565 )   With paraffin wax and stearic acid as the matrix material, biomass base, glass powder and magnesium hydroxide as additives, the temperature-sensitive spheroids are prepared. The mechanical properties of the temperature-sensitive spheroids with different diameters, thicknesses and ratios were analyzed. The results show that the optimal diameter of the temperature-sensitive spheroid is 20.5 mm. The best thickness is 2 mm. The best materials ratio of paraffin, stearic acid, magnesium hydroxide, glass powder and biomass based is 4:1:2:2:1, at this moment, the maximum pressure the temperature-sensitive spheroid can withstand is 43.72 N. Related Articles | Metrics

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Study on synergistic fire extinguishing efficiency of HFO-1336mzz(E) with fluoroolefines CHENG Lu, ZHANG Xiao 2021, 40 (10):  1508-1512.  Abstract ( 1692 )   Based on the parameters of flame height, flame temperature and flame shape obtained from the cup-burner experiments, the synergistic extinguishing effect of trans-1,1,1,4,4-hexafluoro-2-butene (HFO-1336-mzz(E),1336 in short) with N2 or HFC-236fa was investigated. The binary of 1336/N2 fire suppression agent showed positive synergism when the volume fraction of 1336 is less than 15%, and the optimum ratio is 5%/95%. All proportion of 1336/HFC-236fa exhibited positive synergistic extinguishing effect, and the optimum proportion is 87%/13%. The addition of HFC-236fa increased the flame height and flame temperature to a certain extent. This is because the fuel-like property of HFC-236fa caused extra heat release in the system. Related Articles | Metrics

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Study on the pyrolysis characteristics and products of flexible organic plugging material LI Ting, HAN Zi-zhong, XIE Zhuo-heng, XU Shu-ying 2021, 40 (10):  1513-1516.  Abstract ( 1563 )   The thermogravimetric infrared (TG-FTIR) technology was used to study the pyrolysis characteristics of flexible organic plugging materials by changing the heating rate, particle size and atmosphere. The results showed that the faster the heating rate, the slower the pyrolysis reaction proceeded; the smaller particle diameter was more conducive to the pyrolysis reaction; Carbon dioxide was the main component of flue gas generated by pyrolysis in air atmosphere, which was mainly generated by the carbonization reaction of C-O bond fracture of resin materials and the decomposition of inorganic components in flexible organic plugging materials. A variety of aromatic compounds such as toluene, benzopyrene, pyridine and quinoline were found in the condensed liquid components of the pyrolysis of flexible organic plugging materials. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (FTIR) analysis were performed on the solid residue after the pyrolysis of the flexible organic plugging materials. The results of the scanning electron microscope showed that the high temperature had a certain impact on the physical and chemical properties of the flexible organic plugging materials. Related Articles | Metrics

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Research on moisture-proof modification technology of ammonium dihydrogen phosphate LI Yun-chuan, WANG Bao-guo, CHEN Ya-fang, TAN Xing 2021, 40 (10):  1517-1520.  Abstract ( 1609 )   Based on the study of the caking reason and anti-caking measures of ADP, stearic acid (SA) was used as moisture-proof agent, water and water / anhydrous ethanol mixed solution were used as moisture-proof agent solvent respectively, and solvent evaporation method was used to modify ADP to reduce its hygroscopicity and achieve the purpose of anti-caking. The influence of process conditions such as solvent evaporation temperature, stirring speed, moisture-proofing agent content, solvent type, and solvent addition volume on the particle size of ADP composites was studied. ADP composites under different process conditions were prepared, and their particle size and moisture absorption were tested. The results show that when the SA content is 3%, the mixed solution of 15 mL water and 15 mL absolute ethanol is used as the solvent, the evaporation temperature is 90 ℃, and the stirring speed is 400 r/min, the moisture-proof effect of the ADP composite is the best: the particle size is 50 μm, the moisture absorption rate is reduced from 2.79% to 0.92%, and then the theoretical analysis is carried out. Related Articles | Metrics

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Pyrolysis characteristics of ground dead combustibles in the Bilahe forest area in Inner Mongolia ZHANG Jin-qi, ZHOU Mei, ZHAO Peng-wu, SHU Yang 2021, 40 (10):  1521-1524.  Abstract ( 1625 )   Taking five forest types such as Xing'an larch birch mixed forest as the main research object, the pyrolysis process of the sample was analyzed by TG-DTG curve by thermogravimetric analysis, the kinetic analysis of the rapid pyrolysis stage of the sample was carried out by Coats-Redfern integral method, and the comprehensive analysis of ignition temperature, activation energy E and pyrolysis characteristic index P was carried out, in order to evaluate the fire resistance of each combustible sample. The results show that 264 ~ 411 ℃ is the rapid pyrolysis stage and the main stage of thermal weight loss, and the weight loss reaches more than 82.26% of the initial weight loss. Among them, the activation energy E of Xing'an larch forest is relatively high, the thermal stability is relatively strong, the pyrolysis characteristic index P of Xing'an larch birch mixed forest is relatively low, and the pyrolysis behavior is relatively difficult. Building Xing'an larch birch mixed forest as a fire prevention tree species and establishing a fire isolation zone can reduce the combustibility of the forest and reduce the possibility of forest fire. Related Articles | Metrics

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Design and simulation of the telescopic air duct of the crawler forest wind fire extinguisher YANG Chun-mei, WANG Cheng, LIU Jiu-qing, DING Yu-cheng 2021, 40 (10):  1525-1528.  Abstract ( 1594 )   In order to solve the problem of difficulty in extinguishing tree crown fires of a certain height or surface fires of a certain degree and low efficiency of extinguishing in forest fires, the author designed a crawler forest wind fire extinguisher. In this study, the overall structure of the crawler forest wind fire extinguisher was designed, and the core component of the telescopic air duct was theoretically calculated and structured. Through the simulation of different shapes of air ducts, the speed cloud diagram of the air outlet was obtained, and the shape of the air duct of the design was determined. The design was compared with the actual fire extinguishing simulation of the 6MF-32 portable wind fire extinguisher to verify the optimal design parameters. The simulation results show that this study can meet the fire extinguishing requirements under specific heights and specific conditions, greatly improve the efficiency of fire extinguishing, and reduce the risk of firefighters participating in fire fighting operations. Related Articles | Metrics

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Analysis on the progress of forest fire research in China from 2000 to 2020 WANG Rui-chen, , , LONG Teng-teng, , , WANG Qiu-hua, , 2021, 40 (10):  1529-1533.  Abstract ( 1901 )   In order to understand the development status and research directions related to forest fires in China, bibliometric was used to analyze the forest fire research literature in the China national knowledge infrastructure(CNKI) database from 2000 to 2020. A knowledge graph was draw with the help of CiteSpace. Keyword clustering, and a combination of keyword emergence and timeline graph method were used to analyze frontier hot keywords. The results showed that the main themes of forest fire research papers are forest fire occurrence rules and influencing factors, forest fire management, forest fire prevention, Daxing'an Mountain range; the authors need to strengthen collaborative research; future research hotspots can be summarized as forest fire prevention research, including forest fire predicting forecasts, biological fire-resistant forest belts, forest fire danger. The analysis of the results enables scholars to deepen the overall understanding of this field and to look forward to future research hotspots. Related Articles | Metrics

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Numerical simulation of litter burning on the surface of Korean pine forest LIU Chun-ying, XIN Ying 2021, 40 (10):  1534-1538.  Abstract ( 1542 )   Using PyroSim, a large-space model of the litter layer on the surface of the Korean pine forest was established, and the burning temperature, heat release rate, and smoke concentration of the litter layer were numerically simulated. The litter layer on the surface of the Korean pine forest was tested to explore the burning and spreading process of the litter layer on the surface of the Korean pine forest. The simulation results show that the temperature of litter on the surface of the Korean pine forest is about 100～490 ℃ during burning. With the increase of height, the range of temperature decrease gradually becomes smoother from violent; when burning for 150 s, the heat release rate reaches 7.5105 kW, and there is the upward trend; the CO2 volume, concentration in the flue gas reaches about 8%～10%; when the flowing wind speed in the fire site is 2 m/s, the flue gas concentration drops by about 65%. The experimental results show that the burning temperature curves of litters are similar to the simulation results, and the PyroSim software can reasonably simulate the burning process and development trend of the surface litters of Korean pine forest. Related Articles | Metrics

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Studies on the influence of combustible bed structure on combustibility evaluation YANG Yan-bo, XU Li-na, ZHOU Yong, WANG Ze-jun 2021, 40 (10):  1539-1543.  Abstract ( 1560 )   In order to clarify the influence of combustible bed structure characteristics on combustibility evaluation, taking 7 species in the south China as an example, under the three combustible bed structures, direct evaluation method and principal component comprehensive evaluation method were used to evaluate the results of cone calorimeter, the peak heat release rate and the average effective heat content. The results showed that the correlation between the PHRR and AEHC of the 7 species became worse due to the bed structure. And it has a greater impact on the direct evaluation method of combustibility of combustibles using PHRR and AEHC; the main component comprehensive evaluation method under different combustible bed structures has obvious influence, and the rank correlation is poor under the three structure conditions. It shows that based on the results of a cone calorimeter with a bed structure, the use of the principal component comprehensive evaluation method to evaluate the combustibility of combustibles needs to be further studied. Related Articles | Metrics

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The thought on constructing a new pattern of fire and rescue higher education in the new era QI Fang-zhong 2021, 40 (10):  1544-1546.  Abstract ( 1736 )   : This paper reviews the centennial development of higher education in China, summarizes the successful experiences on the reform and development of higher education, reveals the fundamental mission, and points out the direction for fire and rescue higher education. Finally, according to the original aspiration and mission of China Fire and Rescue Institute，the paper has put forward measures of constructing a new pattern of fire and rescue higher education in the new era, such as taking root in fire and rescue, aggregating forces, tamping the groundwork, combinating establishment and abolishment. Related Articles | Metrics

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Study on the location selection of airport fire stations for different runway configurations NIU Xue-min, LUO Jie 2021, 40 (10):  1547-1550.  Abstract ( 1624 )   The distribution of airport fire stations is generally ignored in the airport planning, resulting in a waste of resources and reducing the efficiency of emergency rescue. In view of the above problems, this study focuses on the study of the distributions of fire stations for single runway, parallel runway, cross runway and V-shaped runway on the basis of resources saving, responsibility area full coverage and overlapping area reducing. It is found that only one fire station set is capable of protecting single runway, parallel runway and cross runway under some circumstance. However, it is difficult for V-shape runway to be protected with a fire station, and V-Shape runway should be considered as two independent runways. The configuration method can provide a theoretical support for the distributions of airport fire stations. Related Articles | Metrics

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Discussion on the new models of fire protection products supervision after deepening the reform of fire protection law enforcement LI Qian 2021, 40 (10):  1551-1554.  Abstract ( 1645 )   Since the deepening of fire enforcement reform, market access restrictions for fire protection products have been relaxed, and the competent departments of the industry have been reformed and reorganized. Various factors lead to many problems in the transitional period, such as the lowering of the market access threshold of fire protection products, the diversification of circulation channels, and the decline of product quality qualification rate. Through the analysis of the relevant data on the quality of fire protection products, this paper analyzes the causes of the current problems, and puts forward practical methods to promote quality management of fire protection products under the model of segmented supervision after deepening the reform of fire protection law enforcement, so as to solve the prominent problems existing in the supervision and law enforcement of fire protection products at the present stage, effectively improve the unhealthy market competition behavior and purify the fire protection product market. Related Articles | Metrics

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Monitoring and early warning technology of building structure collapse in fire FANG Zhi-long 2021, 40 (10):  1555-1557.  Abstract ( 1674 )   Some typical cases of building structure collapse in fire and buildings that did not collapse after long-term fire in China in recent years were summarized. The process and key technologies of collapse monitoring and early warning were introduced. The research situation of monitoring and early warning of building structure collapse in fire in recent years was summarized. The analysis shows that there are many related studies on collapse monitoring and early warning using structural deformation, temperature, vibration and other characteristic parameters, but it is in the stage of theoretical research, which is still far from practical application. Facing the actual needs of fire rescue, convenient, easy-to-use, accurate and effective system and multi-method combination of collapse monitoring and early warning methods are worthy of attention. Related Articles | Metrics

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Thoughts on the fire safety of a city CHEN Yin-lei 2021, 40 (10):  1558-1561.  Abstract ( 1671 )   With the acceleration of urban development and the rapid transformation of industrial structure, "4 incompatible problems "gradually appeared on the fire safety work of a city at the south of Zhejiang Province in points of supervision strength, basic facility, rescue strength and digital control. Combining with the work practice, it is suggested to start from 5 aspects of strengthening top-level design, improving the governance system, driving innovation, tamping the base course foundation and strengthening the team development, and promote the fire control work to a new level. Related Articles | Metrics

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Shortage and reconstruction of urban agglomeration fire plan LUO Yun-qing, YI Lan, WANG Wei-xuan, LI Shan 2021, 40 (10):  1562-1564.  Abstract ( 1596 )   Taking the Guangdong-Hong Kong-Macao Greater Bay Area as the study object, the situation, problems and challenges of fire and rescue work as the important national strategic layout were analyzed. Under the situation of lacking urban agglomeration fire plan, the reconstruction mechanism of super urban agglomeration fire plan was explored. The longitudinal penetration of country major strategy was implemented. The innovation was taken as benchmark. The forward looking and operable developing path was put forward, to push the development of Greater Bay Area fire and rescue work. Related Articles | Metrics