Study on gas control in upper corner of working face based on hanging tube drainage device in goaf

In order to effectively control the gas over limit in upper corner of working face, combined with the actual situation in the field, the numerical simulation software Fluent was used to study that the drainage device of hanging tube in goaf solve the problem of gas over limit in upper corner of working face with "U" type ventilation. The gas accumulation law in the upper corner was simulated, the buried depth and negative pressure parameters of the hanging pipe in the upper corner were optimized, and the shape and size of the drainage device were determined.The study shows that when the buried depth of the hanging tube is 3 m and the negative pressure is 10 kPa, the installation of 1/4 umbrella drainage device with a length of 0.4 m and an opening angle of 60° can best control the gas concentration in the upper corner, and the gas concentration in the upper corner can be controlled at about 0.75%. The hanging tube drainage device has achieved good results in field application, indicating that the hanging tube combined with the drainage device in goaf can effectively solve the problem of gas concentration over limit in the upper corner.