Memory effect of AE in gas sorption-desorption cycles of coal

摘要

Acoustic emission signals during gas sorption-desorption cycles are tested under different gas pressures, and the characteristics of acoustic emission generated in coal during gas sorption-desorption processes is analyzed.The experimental results show that acoustic emission signals generated in coal during the gas adsorption process gradually attenuate with the increase of adsorption time, and the process is not continuous but paroxysmal.For the same coal sample, during cycles of sorption-desorption, acoustic emission signals generated during gas adsorption process in coal have memory effect on the maximum gas pressure in earlier stage, that is, when the gas adsorption pressure is lower than the maximum adsorption pressure in earlier stage, both the energy and impulse of acoustic emission are weak;on the contrary, if the gas adsorption pressure exceeds the maximum adsorption pressure in earlier stage, both the energy and impulse of acoustic emission are strong.