Study On Soft Coal Replication And Its Application Technology Based On Continuous Flow Method

As we all know,coal and gas outburst is one of the main dynamic disasters in coal mines,and the consequences are serious.At present,the prominent mechanism,prediction index and its critical value are constantly exploring.Especially before the major breakthrough in mechanism research,the study of prediction index and its critical value is particularly important and requires a lot of implement data.The current laws and regulations have not allowed the occurrence of outburst in coal mines.Both the coal mines and research institutions can not bear the serious consequences.There is also no condition to observe the outburst directly.The research shows that different coal seams have different critical values,Therefore,it is necessary to carry out the research on the sensitive index and critical value of the prediction of the coal seam in the laboratory.so that the results obtained can directly used in the field.The study of prediction index and its critical value is inseparable from the simulation test.However,the moisture and molding pressure in coal samples have great influence on the determination of parameters and the results of simulation.The forming pressure will affect the pore structure distribution of coal samples.The pore structure reflects the adsorption and desorption capacity of gas.The more pores,the stronger the ability to adsorb and desorption gas.Moisture in coal seam also has same affects.At present,the moisture and molding pressure of coal samples are not clearly defined in the simulation experiments,which are often based on experience and estimation.Can the obtained critical values be directly used in the coal mine scene? It needs a lot of practical testing.If we can simulate a coal seam with similar density,moisture and structure to real soft stratification in the laboratory.The obtained parameters and critical values can be directly used to guide the prediction work.However,the accuracy of this method for simulating of soft layer has not been verified by experiments.For this purpose,this paper carries out mechanical and EDEM software simulation analysis of coal seam compaction process.It shows that the apparent density corresponds to the forming pressure of coal seam.16 groups of outburst simulation experiments were carried out with four coal samples from Xuzhou ? Hebei ? Henan and Shenyang,which contains 8 groups of benchmark experiments and 8 groups of contrast experiments.The initial gas flow rate method is used to compare the difference between the simulated coal seam and the standard coalseam.In the laboratory,a soft layer was simulated as the benchmark coal seam.The initial gas flow,moisture and apparent density was tested of coal seam.Comparing the simulated coal seam with the standard,the average error of the two forming pressure is 4.88% and the average error of the initial gas flow is 3.63%.It is proved that the simulation soft layer is very close to the reference coal seam and can be used to measure the prominent sensitive index and critical value of the actual coal seam.In the field test of Xinyuan coal mine.It is assumed that the forming pressure of its soft coal sample is 31.42 MPa,and the critical value of initial gas flow is 63.04L/m.The safe production of mine has been realized.Therefore,it is highly reliable to use this method to simulate the soft layer experiment.