Study on multi field coupling numerical simulation of nitrogen injection in goaf and fire-fighting technology

Wang, Wei; Qi, Yun; Liu, Jiao

doi:10.1038/s41598-022-22296-9

Cited by 16 publications

(9 citation statements)

References 20 publications

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“…Therefore, C 2 H 4 (139.9˚C) is regarded as the symbolic gas for coal spontaneous combustion to achieve severe oxidation and temperature rise. According to field experience, most scholars regard 10% oxygen concentration as the unified index for dividing the asphyxiation zone in a goaf [22][23][24][25][26]. Fig 8 shows that the closed oxygen consumption test results of coals in the different mines were different, indicating that the oxygen consumption capacity of different coals differs under the same conditions.…”

Section: Results Of Temperature Programmed Experiments and Analysismentioning

confidence: 99%

Spatio-temporal evolution law of gas-temperature coupling field in “110 method” goaf and prevention of spontaneous combustion

Wei,

Fang,

et al. 2023

PLoS ONE

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To investigate the distribution characteristics of spontaneous combustion disaster (SCD) zones in the goaf of "110" mining method with U + L ventilation system and formulate corresponding fire prevention measures, enclosed coal oxidation experiments were carried out to measure the oxidation characteristics of Dongrong Coal Mine bituminous coal sample. A coupled 3DEC-CFD (3 dimensional Distinct Element Code) model was established. The 3D transient distribution characteristics of SCD zones in the “110” mining goaf under U+L ventilation condition were analyzed. Nitrogen injection in the tailgate was proposed for coal spontaneous combustion prevention. The results show that air leakage changed the distribution of oxygen and temperature fields in the “110” goaf, causing the region 20~60 m parallel to the retained roadway to remain in the oxidation zone for spontaneous combustion. As the working face advanced, the area change curve of SCD zones in the “110” goaf exhibited a “double inflection point” pattern. Eliminating the “retained roadway oxidation zone” can effectively reduce the spontaneous combustion risks in the “110” goaf and ensure mining safety. This study enriches the mechanisms of coal spontaneous combustion.

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Section: Results Of Temperature Programmed Experiments and Analysismentioning

confidence: 99%

Spatio-temporal evolution law of gas-temperature coupling field in “110 method” goaf and prevention of spontaneous combustion

Wei,

Fang,

et al. 2023

PLoS ONE

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“…Spontaneous combustion in gas extraction borehole is a internal-caused fire in coal mines influenced by multiple factors, which seriously restricts the high production efficiency and safety of mines 1 , 2 . The initial temperature of the coal seam rises due to the increase of mining depth and intensity, bringing new challenges to the prevention and control of coal spontaneous combustion disasters 3 , 4 . Therefore, the risk of spontaneous combustion in extraction borehole is becoming increasingly serious, especially for high gas-prone spontaneous combustion coal seams.…”

Section: Introductionmentioning

confidence: 99%

Prediction model of spontaneous combustion risk of extraction borehole based on PSO-BPNN and its application

Wang,

Liang,

et al. 2024

Sci Rep

Self Cite

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The feasibility and accuracy of the risk prediction of gas extraction borehole spontaneous combustion is improved to avoid the occurrence of spontaneous combustion in the gas extraction borehole. A gas extraction borehole spontaneous combustion risk prediction model (PSO-BPNN model) coupling the PSO algorithm with BP neural network is established through improving the connection weight and threshold values of BP neural network by the particle swarm optimization (PSO) algorithm. The prediction results of the PSO-BPNN model are compared and analyzed with that of the BP neural network model (BPNN model), GA-BPNN model, SSA-BPNN model and MPA-BPNN model. The results showed as follows: the average relative error of the PSO-BPNN model was 4.38%; the average absolute error was 0.0678; the root mean square error was 0.0934; and the determination coefficient was 0.9874. Compared with the BPNN model, the average relative error, average absolute error and root mean square error decreased by 9.35%, 0.1707 and 0.2056 respectively; and the determination coefficient increased by 0.1169. Compared with the GA-BPNN model, the average relative error, average absolute error and root mean square error decreased by 3.19%, 0.0602 and 0.0821 respectively; and the determination coefficient increased by 0.0320. Compared with the SSA-BPNN model, the average relative error, average absolute error and root mean square error decreased by 5.70%, 0.0820 and 0.1100 respectively; and the determination coefficient increased by 0.0474. Compared with the MPA-BPNN model, the average relative error, average absolute error and root mean square error decreased by 3.50%, 0.0861 and 0.1125 respectively; and the determination coefficient increased by 0.0488, proving that the PSO-BPNN model is more accurate than the BPNN model, GA-BPNN model, SSA-BPNN model and MPA-BPNN model as for prediction. When the PSO-BPNN model was applied to three extraction boreholes A, B, and C in a coal mine of Shanxi, the prediction results were better than the BPNN model, GA-BPNN model, SSA-BPNN model and MPA-BPNN model, proving the accuracy and stability of the PSO-BPNN model in predicting risk of borehole spontaneous combustion in other mine.

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“…Geng et al proposed a full section nitrogen curtain dust suction method for goaf in U-shaped ventilation working faces, which has been successfully applied in underground goaf fire prevention scenarios. Wang et al , established a multifield-coupled numerical model for nitrogen injection in goaf and obtained a fitting curve between nitrogen injection parameters and the width of the goaf spontaneous combustion zone. They used a fire prevention technology combining spray loss wind and nitrogen injection for engineering applications, effectively controlling the spontaneous combustion of residual coal in goaf.…”

Section: Introductionmentioning

confidence: 99%

Study on Inerting Characteristics of Gas Coal by the Inerting Concentration and Ratio of an Inert Gas Mixture

Yu,

Sha,

Jin

et al. 2024

ACS Omega

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To study the effect of the inert gas mixture concentration and ratio on the spontaneous combustion reaction of gas coal, a combination of experimental research and theoretical analysis was used to study the pyrolysis and combustion kinetics characteristics of gas coal and further explore the influence of inert gas on the inerting characteristics of gas coal. Research has shown that during the entire heating reaction process of gas coal, the concentration of inert gases has little effect on the drying and desorption stages, but there is a significant lag phenomenon in the characteristic temperature points of active decomposition and degassing stages. Under the same concentration of mixed inert gases, the higher the relative percentage content of CO 2 , the more significant the change and the better the inhibitory effect. The higher the volume fraction of the inert gas, the higher the cross-temperature point. In the late stage of rapid heating of coal samples, when the volume fraction of inert gas is 40%, the rate of temperature rise increases rapidly. In a pure air environment, CO begins to be released at 80 °C, and when the temperature rises to 130 ∼ 140 °C, the concentration of CO begins to rapidly increase. Under inert conditions, the higher the relative percentage content of inert gas is, the higher the temperature point at which CO is generated. When the experimental conditions are a mixture of 30% N 2 and 10% CO 2 as inert gas, the optimal inerting effect has been achieved. The research results provide a theoretical basis for determining the optimal ratio of inert gas inerting concentrations to achieve fire prevention and extinguishing.

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Study on multi field coupling numerical simulation of nitrogen injection in goaf and fire-fighting technology

Cited by 16 publications

References 20 publications

Spatio-temporal evolution law of gas-temperature coupling field in “110 method” goaf and prevention of spontaneous combustion

Spatio-temporal evolution law of gas-temperature coupling field in “110 method” goaf and prevention of spontaneous combustion

Prediction model of spontaneous combustion risk of extraction borehole based on PSO-BPNN and its application

Study on Inerting Characteristics of Gas Coal by the Inerting Concentration and Ratio of an Inert Gas Mixture

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