Application of numerical simulation for gas-discharge of goaf in gas enrichment mines

According to the design of goaf gas discharge in Sihe mine, the authors established the finite element numerical model for infiltration flow and diffusion in heterogeneous goaf. It can visually depict the gas emission course in goaf, the gas distribution rule and the hydrodynamics principle for gas accumulation in return corner of a goaf. The simulation result shows that by using return connected lane for air leakage diversion and gas discharge in proper order, we can reduce gas concentration in return corner greatly, at the same time, if the method is used properly, we may also fully restrain the gas in the goaf from swarming into working faces and reduce distributed air quantity of drainage roadways. To the gas discharge in goaf of high gas mines, the authors bring forward a design scheme:discharging and drawing out gas while excavating coal, which can control goaf gas synthetically, and the optimum position range of gas drainage, drainage flux, and the lowest critical limit of the indicating air quantity are also given.