| The disaster caused by the spontaneous combustion of the coal left in the goaf severely affects and threatens the safe production of the coal mine.The flow field simulation is an important method to study the law of occurrence of disasters in the goaf,and it is used in the prevention of coal spontaneous combustion in the goaf.Play an important role.The traditional commercial CFD software has good reliability and high requirements on the user's computational fluid dynamics capabilities.However,the industry's first-line technicians have the need for easy operation and analysis of the flow field in the goaf.The development of flow field simulation software based on ObjectARX technology can meet the requirements.This demand.Therefore,it is of great significance to study the simulation software of goaf flow field.The finite element model for the flow field in the goaf is studied.Based on the non-linear iterative method of variable permeability coefficient,the nonlinear seepage flow model in the goaf is obtained.Based on the characteristics of the gob area,basic assumptions are made about the medium and flowing gas in the gob area.Under this,assumption,the mathematical model of the flow field in the goaf is obtained based on the porous media mechanics theory and the corresponding boundary conditions,and based on the triangle finite element.The finite element solution model for the flow field in the goaf was constructed and then the nonlinear seepage iteration theory with variable permeability coefficient was used to study the calculation method of the velocity field in the nonlinear goaf.Finally,through an example of the goaf,the distribution solution of the seepage coefficient,the pressure of the discrete triangle element node and the nonlinear velocity are calculated,which verifies the feasibility of the nonlinear solution model for the flow field in the goaf.The ObjectARX-based goaf flow field simulation program was developed and the developed simulation program was applied to the goaf area of the SI 2012 working face of the Carlina coal mine.The distribution of the flow field in the goaf was obtained and analyzed.The air leakage law of the working face under the ventilation system and the roadway along the empty road is compared with the actual measured data and the simulation result data,which verifies the accuracy of the model and the procedure for solving the flow field in the goaf.Based on the visualization results of the flow field distribution solution in the goaf,the three zones of spontaneous combustion in the goaf were divided.In the application process of this program,the establishment of models,set the boundary conditions and the calculation of the operation process is simple,the reliability of the calculation results is high,the visualization effect is good,and the calculation results can be used as a reference basis to perfect the technical measures for coal spontaneous combustion prevention in the mine goaf. |
PDF Full Text Request