To better perform the experimental practical teaching and training of mining safety majors and cultivate first-class comprehensive top-notch talents in safety emergencies，a virtual simulation experimental teaching system for mine fire monitoring and prevention based on Unity3D was designed. Firstly，the simulation models were developed by 3ds Max，and then the overall framework of the experimental system for mine fire monitoring and prevention was constructed. Secondly，practical experimental trainings for human-machine interaction were conducted such as external fire monitoring and remote automatic control of disaster relief ventilation door emergency response，internal fire monitoring，and temperature-controlled cell coating chemical agent fire extinguishing emergency control. Finally，a comprehensive evaluation experimental evaluation system was proposed for assessment and evaluation. The results showed that the experimental system had the technical characteristics of immersion，interactivity，and conception of virtual reality，which created an underground three-dimensional virtual simulation scene and realistically displayed the evolution process of mine fires. For the experiments and practical training，the experimental system broke through the limitations of traditional models in terms of time，space，safety，and resources，providing self-directed learning and diverse evaluation methods.

To effectively prevent and control coal mine underground belt conveyor fire accidents and ensure the safety of lives and property of coal mine workers，the fire causes，combustion characteristics，smoke flow characteristics，monitoring and early warning technologies，and prevention measures of mine belt conveyor fires were systematically analyzed. Then，further prospects were proposed based on the current research status. The results showed that the main causes of belt conveyor fire were friction temperature rise，electrical equipment failure，and open flame. There were some limitations for the tunnel fire model and corresponding numerical simulation parameters used to study the fire combustion and smoke flow characteristics of belt conveyors，the actual working conditions and environmental parameters of the transportation tunnel should be comprehensively considered. Although there were monitoring and early warning systems for belt conveyor fires in China，they had some limitations. It was necessary to introduce emerging technologies such as 5G，big data，and artificial intelligence，and combine them with hardware detection and personnel management to improve the coal mine belt conveyor fire prevention and control system，and then comprehensively promote the construction of safety and intelligent in coal mine.

In order to avoid the spontaneous combustion of residual coal from the regenerated roof during coal mining，the characteristics of interior fluid field were clarified，and the dynamic law of coal spontaneous combustion hazardous zone was explored. Taking the spontaneous combustion features of residual coal from the regenerated roof of a mine in Shandong province as an example，the numerical simulation method was used to simulate and compare the air leakage characteristics of goaf and regenerated roof under different air volume. Subsequently，based on the structural characteristics of the regenerated roof，the scope of coal spontaneous combustion hazardous zone was determined by adopting a new method of projection superposition judgment with oxygen concentration and air leakage speed as comprehensive indexes. The results of the study show that the oxygen mass fraction of goaf decreases gradually when the depth is smaller than 60 m，while it's no longer affected by the air volume when the depth exceeds 60 m. The oxidation zone is asymmetrically distributed，forming a "triangle" hollow area at the end of the return airway. The air leakage and backflow occurs in the range of 20-40 m in dip direction of goaf，whereas the air leakage velocity of regenerated roof presents a U-shaped symmetrical distribution. The change features of coal spontaneous combustion hazardous zone in the goaf resemble those of the oxidation zone. In contrast，the coal spontaneous combustion hazardous zone in the regenerated roof is mainly distributed near the middle of the intake airway and the inner part of the front middle of the return airway，and the area of coal spontaneous combustion hazardous zone gradually expands and extends towards the tail with the increase in air volume.

To further improve the fire extinguishing efficiency of environmentally friendly foam extinguishing agents，surfactants of the sodium alpha-olefin sulfonate (AOS) and phosphate betaine silicone surfactant (PBSS) and foam stabilizers of inorganic salts and polysaccharides were used to propose environmentally friendly foam extinguishing agents. The effects of inorganic salt and polysaccharide mixtures on surface tension，foaming capability，and foam stability were analyzed. Then the foam stabilization mechanism of the foam stabilizer mixtures was investigated. The results indicated that the inorganic salt and polysaccharide mixtures greatly improved the physicochemical properties of the foam extinguishing agents. The foam fire extinguishing agent mixture by 0.025% xanthan gum，0.125% gelatin，and 0.1% MgCl₂ showed the best overall performance with a surface tension of 24.34 mN/m，an initial foam height of 118.81 mm，and a 25% liquid drainage time of 132.1 s. The foam stabilizing mechanism of the foam stabilizer was attributed to the formation of hydrogen bonds between xanthan gum and gelatin，which greatly enhanced the surface strength of the foam liquid film，thereby effectively slowing down the drainage rate and bubbles coarsening of foam. Moreover，the Mg²⁺ was adsorbed around the AOS/PBSS head group due to electrostatic interaction，which impaired the electrostatic repulsion between the head groups and increased the concentration of surfactant，further improving foam stability.

In order to prevent high-level fire hazards such as spontaneous combustion of top coal and upper layer residual coal，a self-produced gas expansion slurry was prepared by taking industrial solid waste phosphogypsum as the base material，adding components such as sodium bicarbonate and polyacrylamide. Firstly，a thermogravimetry(TG) analyzer was used to study the thermal stability of the slurry at different heating rates. Then，a self-built insulation performance testing system was used to test the thermal insulation performance of the slurry. Finally，the fire extinguishing and cooling performance of the slurry was studied through fire extinguishing experiments. The results show that when the temperature of phosphogypsum based self-produced gas expansion slurry is below 160 ℃，there is a mass loss of 35% to 46% in the slurry. When the temperature is above 160 ℃，the mass fraction of the slurry no longer changes. The thickness of the slurry accumulation reaches 30 mm，and the effective insulation time exceeds 139 min，which can achieve good coverage of coal spontaneous combustion hazardous areas. The slurry expands and diffuses in the cracks of the coal pile，completely enveloping the broken coal from bottom to top，isolating oxygen，and having good cooling and fire extinguishing performance. After 36 min of grouting，the temperature at all points has been decreased to below 50 ℃，and no reignition phenomenon has occurred.

During the construction of underground extraction boreholes，trajectory deviation is common，prone to blind gas extraction areas and produces gas extraction blank zones. In order to ensure that gas extraction achieves the expected results，the 15121 bottom pumping lane，15124 low level lane and 15124 return air lane of Xinjing mine in Shanxi province were taken as the background of the project. We tested the deviation of borehole drilling through the seam and along the seam respectively，calculated the three-dimensional trajectory of the drill holes by using the mean angle full distance method，established the three-dimensional trajectory of the drill holes and the three-dimensional layer relationship of coal rock based on the geological information of coal seam assignment，realized the visualization of the trajectories of the drill holes，analyzed the factors affecting the deviation of the drill holes and the experimental fitting data，and came up with a characteristic of the deviation of the boreholes. The research findings suggest that cross-layer boreholes initially exhibit deviation within fine sandstone layers，with the deviation intensifying notably within the coal seam segment，reaching a maximum deviation of up to 0.52 meters within this section. In the case of in-seam drilling，greater drilling depth results in larger vertical deviations，with an average vertical offset of 1.37 meters at a depth of 40 meters when the opening angles of boreholes are similar. Overall，low-angle boreholes are more susceptible to gravity-induced deviations，leading to a higher likelihood of trajectory deflection，while high-angle boreholes tend to exhibit vertical deviations，albeit with a smaller overall deviation compared to low-angle boreholes. In the horizontal direction，borehole spacing is reduced by 0.68 meters for bottom drainage galleries，0.28 meters for lower position galleries，and 0.54 meters for return airways. The research results effectively guide the design of subsequent gas extraction drilling trajectories under the same geological conditions，provide theoretical support for controlling and eliminating the blind zone of gas extraction，and improve the efficiency and effectiveness of gas extraction.

To enhance the risk prevention and control capabilities of hazardous chemical factories and support emergency decision-making in case of accidents，a multi-level deduction model for the disaster chain was proposed. Furthermore，three categories of key factors (such as thermal radiation，toxic gases，and overpressure) affecting hazardous chemical accidents were considered in the model. Based on the fluid diffusion model and Probit model，the fire probability and sequence simulation algorithm of hazardous chemicals container and the ignition time estimation algorithm of hazardous chemicals explosion were proposed，respectively. Then，the quantitative analysis of the combustion and explosion evolution process in hazardous chemical accidents was performed. For the case of a resin chemical production company in Guangdong province，a disaster chain caused by hazardous chemical leakage accidents was developed to analyze the evolution time and probability of each node. The results indicated that the proposed deduction model can effectively analyze the evolution process of the actual hazardous chemical disaster chain，predict the probability and time of accident nodes，and provide fundamental knowledge for the safety layout of hazardous chemical plants.

In order to solve the problems of easy water loss and poor dust suppression effect in coal seam water injection technology，a dust suppression method which can not only increase the water retention rate of coal seam but also improve the brittleness of coal seam was proposed. A gum-forming dust suppressant based on sodium alginate (SA) was developed. The effects of surfactant，viscosity and injection pressure on the gum-forming dust suppressant were tested by means of specific surface area test，nitrogen adsorption test，scanning electron microscope test and dust production rate test. The test results show that the surfactant is beneficial to the wetting of the coal seam，but has little effect on the dust suppression. The increase of the viscosity of the dust suppressant is conducive to water retention，which can increase the water retention time from 10 h to 30 h，but it will make it difficult for the material to enter the coal seam. The injection pressure has a great influence on the dust suppression effect of the dust suppressant. When the coal seam injection pressure is small，the dust suppressant is difficult to quickly penetrate into the internal pores of the coal. With the increase of pressure，the dust suppressant gradually penetrates into the coal pores. When the injection pressure rises to 3 MPa，the dust suppression effect no longer increases with the increase of pressure，and the dust production rate is reduced from 4% to 2.3%，which is relatively decreased by 50%，effectively reducing the dust production.

In order to reduce the fire safety risk of urban buildings and improve the ability of building units to resist fire accidents，the influencing factors of fire safety were identified from three aspects: building fire protection design，building fire protection facilities and fire safety management，and the assessment index system of fire safety of urban buildings was constructed. A combined weighting-TOPSIS model of structural entropy and information entropy was applied to assess the fire safety risk of each district and each type of building in the cities. The model was validated with 262 buildings in 5 major areas of X city in western China. Finally，fire safety index and comprehensive ranking were obtained，and then the existing weak points of urban buildings fire protection were clarified. The results indicate that comprehensive evaluation order of fire safety is commercial complexes > primary and secondary schools > heritage buildings > high-rise buildings，city center > north of the city > east of the city > west of the city > south of the city. The fire safety risk of urban fringe counties and high-rises need to be paid attention to. The assessment results calculated with this model are consistent with the current situation.

In order to study the evacuation of passengers in a train fire in a vacuum tube transportation system and the smoke spreading law，The fire numerical simulation software FDS and the personnel simulation evacuation software Pathfinder were used to study the evacuation of passengers in case of fire in a high-speed train compartment consisting of 5 cars in a low-vacuum tunnel. Comprehensively comparing the evacuation time，the degree of smoke spread and the CO concentration in 10 evacuation schemes，the best evacuation method for passengers was obtained，and a rescue vehicle was designed to assist evacuation by docking the door of the high-speed train. The results show that: when the passengers in the fire compartment are evacuated to the neighboring compartments，the best evacuation method for the passengers is to leave the two rows of passengers close to the doorway and the rows of passengers close to the fire source at the same time，and then evacuate the passengers row by row by the distance from the fire source from near to far. If the rescue vehicle is used to assist the rescue，when the fire occurs in compartment 1，compartment 2，or compartment 3，the total time to complete the evacuation of all passengers after the arrival of the rescue vehicle is 533，586，and 376 s，respectively. When a fire occurs in compartment 1，the utilization time of door 1 is 200 s; when a fire occurs in compartment 2，the utilization time of door 1 is 145 s; when a fire occurs in compartment 3，the utilization rate of the two doors is more balanced. Therefore，during the actual evacuation，passengers can be guided to fully utilize the two doors in the form of voice announcements to save the evacuation time. The research results can provide a reliable reference basis for the emergency rescue of passengers in future low vacuum tunnel train fires.