Numerical Simulation Of The Methane Distribution In Working Face With Auxiliary Ventilation

There are many different kinds of mine safety issues, one of the most serious is the gas explosion and gas outburst. Heading faces are using local fan ventilations, it is very easy to form local accumulations of gas, then the gas explosions will coming soon.In recent years, the national coal mine safety status gradually improved, one million tons mortality decline year by year. Safety production situation in general is relatively smooth; But, the coal mine security situation of our country compared with other countries is still very grim. Therefore, theoretically study on the local ventilation in the working face and the gas distribution is a feasible way to get risk analysis of gas accumulation, can identify dangerous gas accumulation in the early days and eliminate of mine gas disasters and accidents timelyIn this paper, with the aid of computational fluid dynamics software and based on the theory of fluid mechanics and computational fluid dynamics, under the mine auxiliary ventilation environment, analyze the wind flow rules of working face and the gas distribution, use the Fluent software to establish the mathematical model and physical model for numerical simulation, then acquire the face velocity and gas distribution rules. Application the regulation of the gas in "coal mine safety regulation", change air parameters and face parameters, contrast the different law of gas concentration.According to the results of simulation analysis, the ram air output had a larger impact on the attached effect, when the wind speed increased to v=8m/s, the gas concentration distribution was more uniform, the area of high concentration of high gas area was lesser; Ram diameter change of jet also had a role in attached effect within effective space, when the ram diameter increased to D=600mm, return air gas concentration of outlet within the working face is only0.45%and the gas concentration distribution was uniform; The position of the ram within the limited space had a little effect on attached effect, but considering the need to transport and pedestrians, the supply position is suitable for pick up around two-thirds of roadway, combination with the engineering practice, the selection of ram center for distance h=1.75m; With the aspect ratio in working face increased to3.2m×2.8m, the zone of high gas concentration was lower, ventilated effect was better.In this paper, with the research of local ventilation tunneling faces flow field simulation, obtained the gas concentration distribution of tunneling faces local ventilation,it is an important prerequisite to achieve effective control of mine gas and ensure safety in production of mine.