Permeability Rule Of Carbon Monoxide In The Coal Seam

Spontaneous combustion not only endanger the safety of employees, also waste alarge number of high-quality coal resources, which brings incalculable loss. Theprediction of spontaneous combustion in coal mine accurately has become the focus ofmine safety. Carbon monoxide in coal seam comes from spontaneous combustion in coalseam or other causes, and partly from coal associated which research is in the initial stage.Carbon monoxide has a direct or indirect relation with permeability of coal reservoir.Permeability of coal seam is influenced by the metamorphic degree of coal, coal and rockpore structure, external confining pressure, temperature and gas pressure.The Results are shown as flowing. Fixed carbon and ash increased with theincreasing of coal metamorphism. The volatile content makes the opposite change withmetamorphic degree because of the change of the functional group of coal metamorphism.The fractal dimension of D1has the trend of decline with the increase of coal rank, whichcan verify the large and middle pore in coal decrease for increasing of elevated ranks, andshow the higher permeability of coal is low.With the constant of temperature and gas pressure, the pillar was not destroyedunder the premise, with the increase of confining pressure carbon monoxide gas throughcoal seam permeability decreased layer by layer.If the external pressure and gas pressure maintaining constant, the environmenttemperature lead to relatively reduce of the permeability of coal seam. The thermal stresscan’t extend outward, on the contrary it turned inward because of the external pressure,which caused the fluid channel narrow, the flow rate decrease, the permeability becomessmall.If the outside pressure and temperature are constant, the gas pressure is under1.5MPa, with the increase of pore gas pressure permeability of coal seam gets evensmaller; when the coal goes through power source gas, the permeability in a highpressure increases with the gas pressure increases.