Research Article
Study on Borehole Arrangement Methods for Gas Extraction by Hydraulic Slotting in Long-Distance Through-Coal Seam Tunnel
Table 1
Main parameters for numerical simulation.
| | Model parameter | Parameter value |
| | Model size (m) | | | Simulated buried depth (m) | 200 m | | Young’s modulus of coal (MPa) | 1900 | | Young’s modulus of coal matrix (MPa) | 8469 | | Poisson’s ratio of coal | 0.23 | | Apparent density of coal (kg/m3) | 1400 | | CH4 Langmuir volume constant (m3/t) | 17.1 | | CH4 Langmuir pressure constant (MPa) | 1.729 | | CH4 dynamic viscosity (Pa·s) | | | Borehole temperature (k) | 293.15 | | Initial coal mass fissure permeability (m2) | | | Initial coal matrix permeability (m3) | | | Initial matrix porosity | 0.07 | | Initial coal seam temperature (K) | 303 | | Maximum adsorption deformation of coal | 0.025 | | Coefficient of thermal expansion of coal matrix (K-1) | | | Specific heat capacity of coal (J/kg·K) | | | Specific heat capacity of gas (J/kg·K) | | | Coefficient of heat conduction (J/kg·K) | 0.2 |
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