Research on influencing factors of gas explosion overpressure in U-type ventilation coal face based on orthogonal test

In order to investigate the propagation law of gas explosion in U-ventilated coal mining face and explore the sensitivity of different influencing factors to the overpressure attenuation of gas explosion, numerical simulation was carried out by using Fluent simulation software and combining with the situation of 3906 working face in a mine. By comparing the numerical simulation results with experimental results, and the relative error is less than 15%, which further verifies the reliability of the mathematical model in this paper. Additionally, the key parameters of grid size, iteration time step, and ignition temperature are optimized to 0.2m, 0.05ms, and 1900K, respectively. And the relationship between the peak of the explosion overpressure and the distance of the explosion point of the coal face is exponential, and the explosion overpressure and the distance of the explosion point meets the exponential function relationship. The relationship between the peak explosion overpressure and the distance to the explosion point is in line with the exponential function, and the relationship between the arrival time of the peak explosion overpressure and the distance to the explosion point is in line with the linear function. By designing an orthogonal array, 16 sets of data were obtained through simulation, and the following analyses were conducted based on this data. Using extreme difference analysis to get three main control factors extreme difference value from big to small in order: temperature ? gas concentration ? gas accumulation area pressure, the simulation of the temperature for the explosion overpressure attenuation of the greatest impact, in which the R-value reaches 5.928. ANOVA analysis was applied to study the significance of the main control factors affecting the attenuation rate of explosion overpressure. The range values for the three main control factors is ranked from largest to smallest as follows: temperature ? gas accumulation zone pressure ? gas concentration, with temperature showing a significance level of 31.835, while the other two factors were not significant.