Research Of Features Of Oxygen Consumption And Temperature Rise Of Broken Pillar And Related Application

For spontaneous combustion problem in broken pillar caused by air leakage from roadway in gassy and easily spontaneous combustible coal mines, this paper took air return roadway of18-5face in Nanshan Coal Mine as research object. The transient relationship of mass, energy and momentum in the saturated porous media are used in establishing the3D heat-flow coupling mathematical model in broken coal. The solved results of2D and3D reveal that the oxygen transient into coal from inlet and this influence decreases along with depth. The high temperature region exists in the region which has a certain distance from leakage boundary and the heat up range increase follows increasing porosity and air velocity. The oxygen seepage recedes after plugging in the inlet, and then affects the temperature scope. There is another high temperature zone on the bottom of plugging region but the temperature is lower than the original. The best fire prevention effect is gained by combined measurement which includes plugging and nitrogen injection. According to the boundary conditions for this model,30m plugging plus nitrogen injection with lOnrVmin flux can guarantee no fire happening in100m long roadway at least. Comparison between theoretical and experimental conclusion is favorable. The research thread and research procedure can help site staff deepen understanding of the heat up and cooling law of broken coal and be referenced for the safety work for spontaneous combustion protecting.