Research On Calibration Technique And Device Of Initial Velocity Of Diffusion Of Coal Gas Measuring Device

The initial velocity of diffusion of coal gas is one of the important indicators of coal and gas outburst danger,and the index's accurate measurement is of great significance to the safe production in coal mines.Since the index is put forward,domestic scholars have developed a variety of initial velocity of diffusion of coal gas measurement device,but no scholars have conducted studies on how to calibrate the measurement device.As a result,in order to ensure after long-term use of measurement device still has excellent reliability and accuracy,this paper decideds to conduct a study on calibration device for initial velocity of diffusion of coal gas measuring device.Firstly,the influence factors of initial velocity of diffusion of coal gas have carried on the correlation analysis.Through analyzing the influence factors of two kinds of measuring devices,combined with research on the laws of the third kind of boundary conditions on the diffusion of coal gas,it is concluded that index of initial velocity of diffusion of coal gas is not only related to coal sample itself characteristics,but also with the inflation pressure?the quality of coal samples?design parameters of the measurement device and experimental temperature and other factors.Second,according to?Determination method for index(?P)of initial velocity of diffusion of coal gas?(AQ1080-2009)in the relevant instructions,it is determined that the calibration device is designed according to the principle of constant volume and variable pressure,each component is according to the requirements of the relevant parameters in the industry standard for production.After fixed volume calibration,air tightness test,reliability and uncertainty analysis,we get a standard and reliable calibration device.Then,in the actual process of calibration,we found that the 3.5g of coal sample can't load required by the industry standard for 5ml sample bottles,and through the hulking experiment,we analyzed the reasons.By measuring the initial velocity of diffusion of coal gas that 5ml sample bottles can hold the quality of coal,we calculated the initial velocity of diffusion of coal gas of 3.5g coal,and then compared the initial velocity of diffusion of coal gas that calculated results and 7ml sample bottles of the measured values,we chose a reasonable sample bottle volume for the calibration device.In addition,we also designed the constant temperature experiment platform,selected multiple temperature points and multiple coal samples,and analyzed the influence of temperature on the determination of initial velocity of diffusion of coal gas,through the experiment we can see that in order to achieve accurate calibration of the measuring device,it is necessary to ensure that the calibration device and the measuring device measure the initial velocity of diffusion of coal gas of the same coal sample under the same temperature condition,in addition,the measured temperature of the laboratory should be based on the actual sampling of the coal seam to determine the temperature,so that the results are more instructive.Finally,a calibrated experimental study was conducted on the existing WT-1 initial velocity of diffusion of coal gas measuring device in the laboratory using the developed calibration device.