Abstract: In order to study the characteristics of gas infiltration in coal body surrounded by rigid rock under conditions of different gas pressure, a self-developed coal-gas sorption/desorption simulation device is used to establish a physical coal-gas infiltration model. In the infiltration experiments of coal body, we use two types of gases (N2 & CO2) respectively to monitor gas pressure, total stress and infiltration velocity. The results show that the infiltration velocity of N2 is higher than that of CO2 under the conditions of same temperature and same pressure. The results also show that the relationship between gas infiltration velocity in gas-contained coal and gas pressure is fitted by second-order polynomial. This experimental study has important reference value for the prevention of coal-gas dynamic hazard and the theory and technology of CBM exploration in coal mine.

Key words: coal body, gas, infiltration, pressure