Influence of the injected water on gas outburst disasters in coal mine

The measurement of the injecting water into coal is commonly used to prevent and control methane disasters, which will increase moisture in the coal, and the characteristics of methane desorption in coal will be changed. The methane desorption of different metamorphic degree coal was tested after injecting water on homemade device. The results show that the methane desorption quantity gradually decreased with the amount of injected water. The maximum effect was obtained from the DL coal (a decrease of 82.48 % after injecting water compared with the dry sample), and moderate effects were obtained from the QN coal and the YH coal, and the lowest effect was obtained from the GJZ coal (a decrease of 37.97–47.59 % after injecting water compared with the dry sample). The impact of the injected water on the methane desorption velocity is obvious in the first 40 min, and the methane diffusion coefficient decreases gradually with the amount of injected water. The injected water can reduce the gas outburst disasters by impacting on the methane desorption quantity, methane desorption velocity, and methane diffusion coefficient.