Study on the explosion characteristics of the methane/ammonia/air mixtures in a confined mine roadway

To investigate the impact of ammonia incorporation on the propagation characteristics of methane explosions in the coal mine, the explosion pressure and flame propagation characteristics of methane/ammonia/air mixtures under different ammonia-to-methane mass ratios, initial pressures, and initial temperatures are studied. The results show that the explosion pressure is first decreases and then increases with the increasing of the ammonia-to-methane mass ratio. Meanwhile, the flame position and flame propagation velocity gradually increase. With increasing initial pressure, the peak explosion overpressure, flame propagation velocity, and flame propagation distance all increase. The influence of initial temperature is non-monotonic. When the initial temperature increases from 300 to 700 K, the explosion overpressure rises, and the flame-front propagation trajectory shows a strong positive correlation with temperature. However, the flame propagation is markedly suppressed, as evidenced by a substantial reduction in both the flame-front propagation distance and propagation velocity for T 0 = 900 K. The results from this work can provide insights into the mixed gas explosion and energy utilization.