Study On The Technology Of Fixed Point Continuous Measurement Of Negative Pressure In Borehole For Gas Drainage In Bedding

Improving the efficiency of gas drainage can effectively prevent gas accidents.The gas drainage in my country's coal mines mainly uses bedding drilling,but the drainage effect of most coal mines is not good.There are many reasons.The most important reason is drainage.Negative pressure.When mining gas,only a certain degree of negative pressure is formed inside the borehole,so that the gas can enter the drainage pipeline from the coal mine under the action of the pressure difference,so that it can be continuously drained and stored.However,as the depth of the borehole increases with the mining progress and is hindered by the friction of the borehole wall,the pressure difference when the gas enters the pipeline should also be taken into account,and the negative pressure of the drainage has an impact on the drainage project.A greater impact,so when a proper negative pressure is not formed somewhere inside the drainage hole,and a positive pressure is formed under the action of the gas,then the gas at that location will not be discharged by the drainage pipe.A gas-free space is formed inside the pipeline,which can easily cause gas accidents during coal mining.In this thesis,theoretical and experimental researches on the negative pressure distribution law of gas drainage boreholes are carried out,and the knowledge of seepage mechanics and fluid mechanics is used comprehensively to establish a numerical model of negative pressure changes in bedding borehole drainage,using borehole negative pressure The fixed-point continuous measuring device initially solves the problem of negative pressure value measurement at different parts of the drainage borehole,thereby obtaining the law of negative pressure change along the borehole direction.The test results can be used to evaluate the gas drainage effect of the borehole,and then Optimize the gas drainage process by adjusting the drainage system or drilling construction parameters.In this thesis,an experimental test was conducted on the coal seam gas drainage borehole in the Baiyangling Coal Mine of China Coal Xiyang Energy Co.,Ltd.by using the negative pressure fixed-point continuous measuring device.Mine gas drainage and gas disaster management are of great significance.The paper has 36 figures,5 tables,and 65 references.