Thermo-Hydro-Mechanical Coupling Numerical Simulation on Mechanical Heterogeneity of Coal Rock

Table 1

Model parameters.

Parameters	Value
Initial porosity (decimal)	0.15
Initial pore pressure (MPa)	5
Poisson’s ratio (decimal)	0.31
Skeleton bulk modulus (MPa)	166
Elastic modulus (GPa)	1.85
Coal rock density (kg/m^3)	1320
Thermal expansion coefficient (1/K)
Initial permeability (m^2)
Methane adsorption constant (a/m^3/kg)	14.5
Methane adsorption constant (b/1/MPa)	0.72
Methane adsorption constant (c/kg/m^3)	13.66
Molar gas constant (J/(mol·K))	8.341
Klingberg coefficient (Pa)
Gas molar volume (m^3/mol)	0.0224
Lamé’s constant (λ/GPa)	1.1521
Lamé’s constant (G/GPa)	0.70611
Methane density (kg/m^3)	0.714
Gas viscosity (Pa·s)
Initial temperature (K)	273.15
Coal rock temperature (K)	293.15
Heat capacity ratio at constant pressure (J/(kg·K))	200