Research On Flow Field And Gas Distribution In Gob Of Full-mechanized Mining Working Face

According to the fluid mechanics and the basic theory of porous media, the paper determine to use these control equations about gob air and methane mixture,combined with the method of computational fluid dynamics to take numerical solutions of compound mining flow field and gas distribution in gob.Using Fluent software,from some aspects, such as the values of turbulence parameters k-εin working face,the size distribution of permeability and the gas emission source terms in gob and so on, to study these key issues that will influence on compound mining flow field and gas distribution in gob. The results show that the impact on the simulation results is relatively small when different turbulence energy k and dissipation rateε, but there will be great influence on compound mining flow field and gas distribution law in gob when the air leakage volume, explosion limits of the width and location is different,which caused by the permeability distribution of gob,the size of permeability and gas emission source term. On the basis of ensure as precise as possible reflects the gob caving coal permeability distribution and the size of permeability and closer to the actual situation of gob gas emission source term, we research on different ventilation of W-type, Y-type, J-type numerical simulation of flow field and gas migration law, at the same time also make numerical simulation on three spontaneous zones in mining working face. The results show that W-type Ventilation of mining working face can average pressure fight fire and effectively reduce the gob gas limit the width of the explosion; Y-type ventilation of mining working face can solve the problems of spontaneous combustion of residual coal in gob and the problem of effectively eliminate the face and the corner gas gauge, especially for the two inlet one outlet Y-type ventilation,working face ventilation and the best of dust effects when upper and lower air inlet lane with 1:3. Although it can solve the problem of the corner gas to accumulate and return airway gas gauge, but it will increased gob gas explosion limits and the width of spontaneous combustion when J- type ventilation of mining working face, so it does not be applied to the easily spontaneous combustion of high gas mining working face.