| The gas pressure in coal seam has a great influence on the effectiveness of gas disaster prevention and control.Gas pressure is an important index,which can be used not only as a reference to determine the risk of coal and gas outburst,but also as a basic parameter to verify the gas extraction effect.For many years,the domestic and foreign research on how to obtain more accurate gas pressure value has never stopped,so the indirect method and the direct method have been produced in succession to measure the pressure.These two methods have their own disadvantages to some extent due to the influence of various factors.Among them,the direct method to measure the coal seam gas pressure is main pressure measurement method.As one of the main influencing factors,the hole sealing process has been continuously improved over the years.Proposed in this paper based on circular hidden-interlocking device(including petal shaped blade turbine)sensing pressure self-styled hole,the method of annular hidden-interlocking device installed in peripheral pressure rod,rod matrix,and after the drilling pressure molding,by drive drill pressure rod,pipe reverse device start make petal shaped blade turbine expansion embedded coal wall,combined with pressure measurement sensor technology can achieve rapid integration of seal,the sealing quality was improved.The new pressure measuring technology is mainly composed of gas pressure sensor,special pressure measuring rod,special drill pipe,wire transmission,MCU development board and so on.The pressure measuring principle is: the pressure bar installed between the bit and the drill pipe,and while drilling into the pressure measuring hole,after completion of drilling,drilling rig drive drill pipe and pressure pole reversal valve hole,decorate in the gas pressure sensors on the pressure rod began to work pressure signal collection,through the pressure signal transmission cable transmission to drill on the outside of the microcontroller development board through its signal converter converts pressure signal to digital signal display on the OLED screen,the final pressure measurement is completed.In this paper,this drilling sensing pressure measurement technology is the direct method to determine an improvement of the coal seam gas pressure technology,based on the principle of sensor measuring pressure,pressure test equipment for the relevant improvement,and the development of pressure sensor measuring principle of the machine is applied to simulation of coal seam with the similar simulation experiments confirmed the inversion of hole sealing mechanism and the correctness and reliability of the sensor pressure measurement technology.Through the laboratory similar simulation experiments on 5 sampling points of no.6 coal seam in Dongpang mine,it is concluded that the sensing pressure measurement is feasible and the working conditions of the sensing pressure measurement system are generally applicable.The sealing mechanism of the sensing and measuring pressure system can guarantee the air tightness.Within the allowable range of error,the pressure value in the closed measuring chamber can be measured on the external display screen,and the sensing and measuring pressure is stable.The experimental results provide theoretical guidance and technical support for the industrial application of pressure measurement by driling borehole sensing in coal mine.This paper contains 71 figures,9 tables and 84 references. |
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