Research Article
Increasing Permeability of Coal Seam and Improving Gas Drainage Using a Liquid Carbon Dioxide Phase Transition Explosive Technology
Table 3
Numerical simulation parameters.
| | | Parameters | Values |
| | Coal | Initial porosity φ0 | 0.065 | | Initial permeability k0 (m2) | 3.90 × 10−16 | | Elastic modulus E (GPa) | 1.30 | | Kronecker symbol δij | 1.00 | | Klingberg coefficient m (Pa) | 7.60 × 105 | | Poisson’s ratio | 0.36 | | Shear modulus G (GPa) | 0.52 | | Ash content A | 0.14 | | Moisture content B | 0.04 | | Adsorption constant a (m3/kg) | 14.5 | | Tensile strength σt (MPa) | 0.42 | | Compressive strength σc (MPa) | 3.40 | | Friction angle (°) | 29 | | Adsorption constant b (MPa−1) | 0.75 | | Coal density ρc (kg/m3) | 1400 | | Biot coefficient | 1 |
| | Sandy mudstone of roof | Tensile strength σt (MPa) | 0.61 | | Compressive strength σc (MPa) | 7.78 | | Friction angle (°) | 32 | | Elastic modulus E (GPa) | 4.34 | | Poisson’s ratio | 0.28 |
| | Mudstone of floor | Tensile strength σt (MPa) | 0.47 | | Compressive strength σc (MPa) | 6.33 | | Friction angle (°) | 30 | | Elastic modulus E (GPa) | 2.85 | | Poisson’s ratio | 0.35 |
| | Methane gas | Viscosity μ (Pa·s) | 1.10 × 10−5 |
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