Research on shock wave propagation characteristics of coal and gas outburst under different pulverized coal particle size conditions

Abstract

In order to deeply explore the influence of pulverized coal particle size on coal and gas outbursts, using the self-developed outburst pulverized coal-gas two-phase flow simulation experiment system, the outburst disaster simulation experiment is carried out under the condition of 0.3 MPa carbon dioxide with particle diameters of 3~10 mm, 1~3 mm and 0.5~1 mm, and the characteristics of the wave shape, speed and attenuation law of the shock wave after the highlight are analyzed. The research results show that when the particle size of pulverized coal is 3~10 mm, 1~3 mm and 0.5~1 mm, the maximum shock wave velocity is 358 m/s, 347 m/s and 347 m/s, respectively. The particle size of pulverized coal has little effect on the propagation velocity of the outburst shock wave, but it tends to decrease as the particle size decreases. And the peak overpressure of the shock wave decreases with the decrease of the particle size of the coal. The average attenuation coefficient of the outburst shock wave increases with the decrease of the coal particle size.