Study On The Air Leakage Law Of Working Face In Shallow Seam Of Ningtiaota Coal Mine

The oxygen supplied by Air Leakage is the main reason to cause spontaneous combustion of coal in Gobs. The shallow seam of the Ningtiaota coal mine, due to mining influence, can easily result in surface subsidence, and the surface leakage gob. Therefore, the study on shallow seam mining Air Leakage law of Ningtiaota coal mine, can provide its post-production and disaster management with guidance.In this paper, take mechanized mining face coal N1201 of the Ningtiaota mine's coal mine 2^-2 seam in Shenmu of Shaanxi Province as an instant, the theoretical researching, field observation , and numerical simulation were combined as the methods for researching the surface leakage rule. First, analysis the geological and geomorphological data information of Ningtiaota mine, surface fracture upon the gob, in accordance with the influence of surface cracks, the surface area to the roof of mined areas free falling off the area, roof area and the ground breaking loose sand free region, obtained gob settlement characteristics of surface cracks; Secondly, to carry out on-site field observations. Through distribution and release the surface trace gases SF₆, and the underground testing, then conclude the surface leakage channel of N1201, the intensity of air leakage; By analyzing the oxygen law in gob, and provides support for further analysis. Finally, with the previous research findings of fracture surface goaf law studied, the determination of air leakage channel and observations, simplify appropriate parameters of surface leakage, to establish the porous flow model. Based on this model, through the CFD software FLUENT,simulate the pressure distribution in gob and the oxygen distribution law to analysis the air leakage further, and conclude the potential spontaneous combustion danger zone in gob. By simulation and analysis the surface leakage law of Ningtiaota mine, the 2^-2 mine seam spontaneous combustion danger zone was determined, to provide prevention and treatment basis of coal spontaneous combustion for the normal production, and it was the essential data and a certain reference for identifying similar Gob mine risk prevention and management in mine safety for the production under similar conditions.