| The coalfield fire is a complex dynamic system which is a field coupling in semi-closed porous medium. At present,the seepage in fire zone haven't more perfect theory.So it is important to study the law of seepage in coal fire zone and master the law of development and changes in fire zone.In the article,the Shangyi fire zone in Rujigou coalfield was taken as example. Methods of experiment, theoretical analysis and numerical simulation were combined to study the law of seepage in coal fire zone, carry out the following research work:(1) Set up the air seepage of loose coal experimental device.Determine the permeability coefficient of coal which is different size and grading,calculated the graded fractal dimension of mixed coal, determined the permeability coefficient of coal,quoted the graded fractal dimension can comprehensively react the law of seepage in loose coal, fitted the function of fractal dimension of graded and permeability coefficient.(2) Research the oxidation and heat features of the coal in fire zone by the device of temperature-programmed.Determine the oxygen uptake rate and heat intensity of different coal temperature,fitted the influence function of particle size.(3) Establish the physical model of fire zone based on the actual situation.The two-dimensional mathematical model of the temperature field,the oxygen concentration field and the airflow field was established by the percolation theory with porous medium,heat transfer theory and mass transfer theory,determined the boundary conditions.(4) Based on the experiment research and the mathematical model.After the hypermesh and set boundary,the airflow field,the oxygen concentration field and the temperature filed of the fire zone were simulated by Fluent under the temperature at 334K,374K,414K,434K and the wind speed at 0.2m/s,0.5m/s.The simulation results were analysed by theoretical.Reveal the variation of the airflow field, the oxygen concentration field and the temperature filed of the fire zone.
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