| Mine fires occur in narrow and narrow roadways,and the fires are sudden.If there is no timely disaster relief in the early stage,the fire will develop rapidly and it is difficult to implement fire fighting and relief work in a limited space.It is one of the five major mine disasters.In all forms of mine fires,the downdraft fires are the most complicated in the fire period,and the fire hazard is the most serious.Therefore,the study of the flue gas migration law of the downwind fires under different conditions and the wind flow control during the catastrophic period can effectively prevent and control the fire development.Disaster relief commanders make effective disaster avoidance and disaster relief decisions in the fire,and have important theoretical and practical significance in formulating emergency rescue plans.In this paper,the combination of theoretical analysis and numerical simulation is used to simulate the wind-flow fire in the wind tunnel of the working face,and the change of the smoke movement during the fire period and the related parameters of the fire period are analyzed.At the same time,a wind control scheme was established for the downwind wind fire on the inlet side,and its effectiveness was verified by numerical simulation.The main research contents and conclusions are as follows:(1)In the current mine fire simulation,most of the fire source is simplified into an ignition source,and the process of fire spread cannot be restored.This paper uses the US NOISH tape fire test as the background to establish a linear burning source of flame with FDS and quotes NOISH tape.The experimental data of the fire experiment was verified.The fire source was selected from the t2 fire source model,and the maximum heat release rate was 8 MW at 218 s.The tape was made of styrene-butadiene rubber SBR tape.(2)Establish a downwinding fire model for the working face into the wind tunnel,and set the dip angle of the inlet duct to 0°,5°,10°,15° and 20°,and use the FDS software to fire the five groups of models.The simulation is carried out to study the variation law of flue gas parameters in the downwind of the inlet wind tunnel under different slope conditions.Analysis of the simulation results data,the main conclusions are as follows:There is a critical value for the dip angle of the downstream airflow roadway in the working face.When the roadway inclination angle is less than this value,the affected area is the working surface and the return airway.When the value is greater than this value,the affected area is the mining lane and other working surface of the mining area;When there are conditions in the wind tunnel,use a small dip angle as much as possible to control the disaster area during the fire.In the downwind fire,the increase of the slope of the roadway will cause the concentration of the upper flue gas of the downwind side roadway to decrease,and the lower layer smoke will be less affected.(3)Taking the 10-106 working face of Shanxi Huipo Mine as the background,the wind control plan for the downwinding fire in the working face of the wind tunnel is proposed.The FDS is used to simulate the smoke movement and parameters of the fire before and after the wind control,and the effectiveness of the proposed wind control scheme is verified.Analysis of the simulation results,the main conclusions are as follows:The working face enters the wind tunnel and the downwind fires.In the absence of mining measures,the main hazardous areas are the working face,the intake tunnel and other working faces.Under this circumstance,the workers on the working face cannot escape safely;the measures to open the return air connection,increase the air volume and increase the wind resistance of the return air roadway can effectively control the influence range of the downwind fire.Ensure that workers on the work surface are evacuated to a safe area. |
PDF Full Text Request