Development and application of experimental device for mechanical and thermal coupling seepage characteristics of coal and rock

In order to further study the seepage law of coal rock and gas under the comprehensive action of multiple factors, a stress and temperature coupling seepage characteristics experimental device was self-developed. The device has obvious advantages: it can be used to simulate the in-situ geological condition of coal reservoir, and carry out the experiment of gas seepage characteristics of coal and rock under the coupling action of temperature, water content, in-situ stress and gas injection pressure, and the design of back pressure control system ensures that the seepage experimental characteristics of coal and rock accord with the actual situation of coal mine. At the same time, the experimental study on the gas seepage characteristics under the multi-factor comprehensive action is carried out with the device. The results showed that: under the conditions of constant temperature and gas injection pressure, with the increase of loading stress, the permeability of coal sample decreases significantly, but when the increase of loading stress is the same, the decrease of permeability is obviously smaller; the permeability of the coal sample gradually decreases with the increase of the water content, but the decreasing trend will gradually slow down, and the two are in line with the negative correlation change law.