Abstract: In order to solve the problem of fluctuation overrun of gas in upper corner of S5-2 working face, the paper has analyzed some elements like coal mining technology and periodical weighting to expound the cause of the upper corner gas fluctuation overrun. The method that the drainage device is used to change the corner eddy current field has been provided to optimize the tail-road configuration and to change the upper-corner gas vortex field with drainage instrument and to control the fluctuation overrun of gas accumulation efficiently. The Fluent numerical simulation, establishing the upper corner gas air-eddy current field model, has been used to simulate the effect of using the different drainage volume of drainage device to change the upper corner air-gas vortex, and the distribution characteristics of wind speed, wind pressure of local wind. And the ventilation effects for different tail step distance and air distribution numerically have been simulated to analyze the distribution characteristics of wind speed, wind pressure and gas concentration in different places in the working face of configuration and the goaf air flow-gas flow field mode. Combined with the simulating results, the best air distribution amount and step distance of tail roadway in S5-2 working surface and the best method of drainage instrument configuration have been determined. The monitoring results have shown that it has obvious effect on the gas fluctuation limit in upper corner.

Key words: upper corner, drainage, air-gas, tail roadway, step