Adsorption deformation significantly affects the seepage characteristics of coal.However,effect of sorption time on coal permeability and gas pressure has not been investigated systematically.In this study,the sorptio...Adsorption deformation significantly affects the seepage characteristics of coal.However,effect of sorption time on coal permeability and gas pressure has not been investigated systematically.In this study,the sorption experiment of coal samples is conducted to elaborate the importance of sorption equilibration time.Then a coupled coal deformation and gas flow model is established considering the sorption characteristic and permeability evolution.This coupled model is implemented through finite element method to analyze the effect of sorption time on coal permeability and gas pressure.The simulation results reveal that the gas pressure of the coal will change with the adsorption time.The fracture pressure maintains a high level while the matrix pressure is relatively low during the adsorption process.The sorption time has a great influence on the distribution of gas pressure.The smaller the adsorption time is,the lower the gas pressure becomes.展开更多
In the seepage-stress-damage coupled process,the mechanical properties and seepage characteristics of coal are distinctly different between pre-peak stage and post-peak stage.This difference is mainly caused by damage...In the seepage-stress-damage coupled process,the mechanical properties and seepage characteristics of coal are distinctly different between pre-peak stage and post-peak stage.This difference is mainly caused by damage of coal.Therefore,in the process of seepage and stress analysis of coal under the influence of excavation or mining,we need to consider the weakening of mechanical properties and the development of fractures of damaged coal.Based on this understanding,this paper analyzes the influence of damage on mechanics and seepage behavior of coal.A coupled model is established to analyze the seepage-stress-damage coupled process of coal.This model implemented into COMSOL and MATLAB software to realize the numerical solving.Two examples are adopted to verify the correctness of the model and some useful conclusions are obtained.The numerical model establishes the relationship between microcosmic damage evolution and macroscopical fracture and simulates the whole process of coal from microcosmic damage to macroscopical fracture,and the dynamic simulation of fluid flow in this process.It provides a numerical tool for further research on the seepage-stress-damage analysis.展开更多
基金This study is sponsored by the National Natural Science Foundation of China(No.51679199)the Special Funds for Public Industry Research Projects of the Ministry of Water Resources(No.201501034-04 and 201201053-03)the Key Laboratory for Science and Technology Coordination&Innovation Projects of Shaanxi Province(No.2014SZS15-Z01).
文摘Adsorption deformation significantly affects the seepage characteristics of coal.However,effect of sorption time on coal permeability and gas pressure has not been investigated systematically.In this study,the sorption experiment of coal samples is conducted to elaborate the importance of sorption equilibration time.Then a coupled coal deformation and gas flow model is established considering the sorption characteristic and permeability evolution.This coupled model is implemented through finite element method to analyze the effect of sorption time on coal permeability and gas pressure.The simulation results reveal that the gas pressure of the coal will change with the adsorption time.The fracture pressure maintains a high level while the matrix pressure is relatively low during the adsorption process.The sorption time has a great influence on the distribution of gas pressure.The smaller the adsorption time is,the lower the gas pressure becomes.
基金This study is sponsored by the National Natural Science Foundation of China(no.51679199)the Special Funds for Public Industry Research Projects of the Ministry of Water Resources(no.201501034-04 and 201201053-03)the Key Laboratory for Science and Technology Coordination&Innovation Projects of Shaanxi Province(no.2014SZS15-Z01).
文摘In the seepage-stress-damage coupled process,the mechanical properties and seepage characteristics of coal are distinctly different between pre-peak stage and post-peak stage.This difference is mainly caused by damage of coal.Therefore,in the process of seepage and stress analysis of coal under the influence of excavation or mining,we need to consider the weakening of mechanical properties and the development of fractures of damaged coal.Based on this understanding,this paper analyzes the influence of damage on mechanics and seepage behavior of coal.A coupled model is established to analyze the seepage-stress-damage coupled process of coal.This model implemented into COMSOL and MATLAB software to realize the numerical solving.Two examples are adopted to verify the correctness of the model and some useful conclusions are obtained.The numerical model establishes the relationship between microcosmic damage evolution and macroscopical fracture and simulates the whole process of coal from microcosmic damage to macroscopical fracture,and the dynamic simulation of fluid flow in this process.It provides a numerical tool for further research on the seepage-stress-damage analysis.
