Experimental study of the multi-factor coupling effect of coal dust explosion intensity based on Box-Behnken response surface

Coal dust explosion has become one of the most serious accidents in underground coal mines due to its powerful destructive force and extensive damage range. Using the Box-Behnken experimental design method, the influence of multi-factor coupling effects on the intensity of coal dust explosion during the transient explosion reaction process was studied. A total of 45 groups of 20L spherical explosion tests were conducted, observing the macroscopic characteristics of the intensity of coal dust explosion under the coupling effects of five factors: coal dust concentration (A), coal dust particle size (B), coal volatile matter (C), ignition energy (D), and ignition delay (E). The explosion process was monitored by measuring pressure changes, and the maximum explosion pressure (response value Y1) and the maximum explosion pressure rise rate (response value Y2) were determined from the pressure-time curve. The Design-Expert software was used to analyze the experimental results to establish a quadratic regression model for response values Y1 and Y2. The results show that in the variance analysis (ANOVA), the coefficient of determination (R) for Y1 and Y2 is 0.9771 and 0.9258, respectively, indicating a good fit between the model and experimental data. The single factor that has the greatest influence on the maximum explosion pressure (Y1) is ignition energy and ignition delay, and the single factor that has the greatest influence on the rise rate of the maximum explosion pressure (Y2) is coal dust particle size and ignition delay. In the quadratic regression model, the significant two-factor interaction affecting Y1 are AB, AD, AE, BC, CD, CE, and DE, while significant two-factor interaction affecting Y2 are AE, BC, BE, CE, and DE. Among them, ignition delay plays a decisive role in response values Y1 and Y2.The research results can provide a theoretical basis for dust explosion prevention work in underground coal mines.