Numerical Simulation of Thermal-Solid Coupling to Coal-Rock during the Process of Heat Injection Mine for CBM

For gaining effective influence radius of heat injection mine for CBM (Coal Bed Methane) and influence rules of permeability under the condition of temperature and effective stress, heat transfer and elastic mechanics theory combined, hooker law of thermal elastic body introduced, mathematical model of thermal-solid coupling to coal-rock was set up, The weak solution of temperature field and transformation field was given and the software FEPG was used to simulate temperature and stress distribution after 10d with heat injection. The results show that effective influence radius and effective stress both increase along with time of heat injection increasing. The permeability of coal-rock is always larger than initial permeability when the general influence of temperature and effective stress is considered. The effective influence radius of heat injection can supply practical reference to heat injection for CBM mine and the feasibility of heat injection technology for CBM mine is proved.