|
The gas flow in coal law is the basis of the research in the field of coal mine gas prevention and control issues , and the adsorption of the special characteristics of the coal distinguish it from other penetration , adsorption penetration regular gas emission , gas drainage , coal bed methane development, coal and gas outburst prevention and control of basic theoretical research is of great significance . In this paper, the experimental research , theoretical analysis , numerical simulation and field measurement method of combining systematic study of the adsorption of coal gas permeability characteristics . Developed innovative adjustable outlet pressure , temperature controlled gas permeability tester . Under different pressure conditions , by different adsorption characteristics of coal samples , different adsorption properties of gases as well as adsorption circumstances of different amount of gas permeability experiments to study the influence of adsorption on coal permeability . The results show that : the average permeability of the coal seam Darcy's law as the basis for estimates describe the dynamic process of the entire coal seam gas migration error is larger . Stress, gas pressure , temperature and other factors affect the average permeability of the coal seam is changing . The penetration rate as a function of time , space and the gas pressure processing , the process of coal seam gas flow described by Darcy's law is more realistic. Adsorption has an important impact on coal permeability , the stronger the adsorption , the adsorption amount of gas is more , the smaller the permeability of the coal . Mechanism from the adsorption characteristics of the three aspects of the gas - containing coal energy , porosity and effective stress analysis, and the establishment of a mathematical model , based on the numerical simulation . The simulation results show good agreement penetration model with experimental research and field test results .
|