Numerical Simulation on Gas Drainage of Gob Area by Buried Pipe in Working Face Upper Corner

According to the practical status of high gas mine for middle and small types,numerical simulation was adopted to determine the effective plan for gas drainage.Based on permeation fluid mechanics theory,the gob area was regarded as continuous permeation field.The geometry model of gob area was built by GAMBIT.The porosity and viscosity coefficient of caving zone was determined by experiment.Through numerical simulation for gas emission and drainage of gob area by FLUENT,the distribution laws of gas concentration along three directions of working face and optimal parameters of gas drainage for buried pipe were obtained.The results showed that when the pipe pressure was at-100Pa,the gas concentration in pipe and upper corner regularly changed with the pipe position.When the pipe position was two meters high from the ground,one meter long from the return airway in the dip direction and four meters deep to gob area,the effect for gas drainage was best and the gas concentration at upper corner was reduced to 1.1% and 0.7% after the plugging measures was taken.