Experimental study on the dispersion law of disaster gas emitted instantaneously in fully mechanized mining face

In order to study the migration and dispersion law of disaster gas in fully mechanized mining face and analyze the influencing factors of peak volume fraction and distribution of disaster gas during migration, using the method of field test of tracer gas (SF₆) in fully mechanized mining face, a one-dimensional convection-dispersion model was used to quantitatively analyze the migration characteristics of tracer gas. Particle swarm optimization (PSO) was used to estimate the average wind speed and longitudinal dispersion coefficient of roadway in the mathematical model. The results show that the tracer gas in fully mechanized mining face shows a skewed distribution, and the influence area of tracer gas distribution increases with the increase of migration distance. The main influencing factor of the peak value and waveform of the tracer gas concentration curve at the monitoring point is the average wind speed, followed by the longitudinal dispersion coefficient. By comparing the simulation and test values, it can be seen that the dispersion migration law of disaster gas in fully mechanized mining face can be accurately described by using one-dimensional convection-dispersion model.