THE EFFECTS OF GAS PRESSURE ON GAS INFILTRATION CHARACTERISTICS IN COAL

In order to study the characteristics of gas infiltration in coal body surrounded by rigid rock under the 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 this experiment, two types of gases (N2 & CO2) are used respectively to simulate gas penetrating through the tightly contained coal body, and gas pressure, total stress and infiltration velocity are monitored. The results show that the relationship between gas infiltration velocity in gas-contained coal and gas pressure is fitted by second-order polynomial. The results also show that, under the conditions of same temperature and same pressure, the infiltration velocity of N2 is higher than that of CO2. The experimental study is important for coal-gas hazard prevention and CBM exploration in coal mine.