Development and application of gas adsorption model for coal based on particle flow code

Abstract

This study investigated the deformation characteristics and engineering properties of gas-bearing coal. Based on the particle flow discrete element method, the gas was regarded as a flexible solid particle, and the relationship between the radius, elastic modulus and gas pressure of the flexible gas particle was derived through the ideal gas equation. Then, a gas adsorption model for coal based on the Langmuir equation was developed by coupling gas particles with rigid coal particles and applied to the coal and gas outburst evolution process. The results revealed that the flexible gas particles can effectively simulate the flow and deformation of gas, and the gas adsorption model exhibits adsorption deformation characteristics consistent with those of real coal specimens. Moreover, the adsorption model can indicate the adsorption saturation of coal particles at any moment, and the distribution characteristics of gas pressure within the microscopic pores, which is helpful to study the microscopic mechanism of gas adsorption process. Finally, the gas adsorption model for coal was applied to the coal and gas outburst and good simulation results were obtained, which further validated the reasonableness of the gas adsorption model. These studies promote the application of the particle method in the direction of gas-solid coupling research, and also provide a theoretical and numerical basis for the prevention and control of gas disasters.