Gas flow characteristics in micro and nano pores and its LBM numerical simulation

Objectives It is important to study the flow characteristics of gas in coal seams to reveal the mechanism of coal seam gas storage and transport characteristics.The number and structure of micro and nanoscale pores in coal are very complex,and to study the flow characteristics of coal seam gas in micro and nanoscale pores, Methods homogeneous nanoporous carbon films were tested and their pore size and porosity were qualitatively,and quantitatively analyzed by scanning electron microscopy experiments;the experimental study of gas flow in micro and nano pores was carried out by using a nano-scale gas flow characterization experimental device. Results A more accurate characterization of the flow of gases within micro-and nano-pores is obtained by comparing the conventional Darcy percolation model with a model applicable to gas flow at the micro-scale.The apparent permeability of nanoporous carbon films decreases with increasing inlet pressure in a negatively correlated linear law,while the gas permeability decre