Simulation Test And Research On "U+L+High Gas Drainage Roadway" Ventilation System Base On Test Rig Of Three-dimensional Flow Field In Goaf

Based on the working face of15101in shigang as the prototype, using the theoryof mining over strata, gas migration in goaf, similar material, similar model, we builda three-dimensional flow field test rig for goaf with the proportion of1:100.Investigate the reliability of model and the feasibility subsequent experimentscheme through air leakage experiment, pressure stabilities experiment, gasconcentration stabilities experiment and static experiment of the model. Air leakagetest can guarantee air leakage rate of model is less than5%, determine the timeneeded for gas steady flow in the model, Paper main research is gas concentration&pressure distribution in goaf through the “U”,“U+L”,“U+L+Gas drainage roadwaynear mine roof level” three different type of ventilation.Analysis the difference of goaf flow field distribution through change thedistance between lateral roadway with working face, change the pressure between thelateral roadway with return air roadway, and the influence on spontaneous combustionof coal seam under these conditions.Through the analysis,we get the following conclusion:1) The general trend of the flow field distribution in goaf.2) Wind has begun to meet before the central goaf based on the relations ofpressure contours are draw by MATLAB software, the characteristics of thestreamline distribution of asymmetric type, high concentrations of gas zone mainlyconcentrated in the comPaction zone side of return air roadway, this phenomenon ismore obvious when we have high gas drainage roadway, concentration flow fielddistribution appears asymmetric “O” type.3) Air pressure’s change don’t change the distribution flow field of internal goaf4) Through analysis of the concentration flow field and pressure flow fieldcombination with different flow Pattern of wind containing gas, we get the influencesof coal seam spontaneous combustion under this conditions.We provide the basis for gas control and goaf fire prevention by using of theabove experiments, and also provide a basis for working face ventilation Parametersoptimization. In addition, the results of above experiments have certain referencepractical value in the actual production.