Method and device for rapidly measuring residual gas content of underground coal sample

Abstract

According to the method and the device, an underground compressed gas source is used as a power source to drive a pneumatic motor, a coupler, an eccentric shaft and an eccentric rotor to rotate, so that the coal sample is crushed, and the problems of sparks in conventional blade crushing and difficult explosion prevention of a motor are effectively avoided; the desorption measuring cylinder with the liquid level meter can automatically meter the desorption amount after the coal sample is crushed, the temperature sensor can record the temperature change of the coal sample in real time, and the device is safe, explosion-proof, convenient to operate and capable of rapidly and accurately measuring the residual gas amount of the coal sample. According to the method, the coal sample can be directly crushed on site, loss of gas in the transportation process is prevented, underground crushing is performed for 10-20 min, gas desorption data are recorded, meanwhile, the change rule of the temperature of the coal sample in the crushing process is considered, a non-isothermal diffusion mathematical model based on the coal sample gas desorption rule is established to calculate the residual gas content, and the coal sample gas desorption rule is calculated. And the parameter measurement efficiency and the accuracy of a measurement result are improved.

Description

technical field [0001] The invention relates to a method for measuring the amount of gas in a coal seam, in particular to a method and device for quickly measuring the residual gas content of an underground coal sample, and belongs to the technical field of gas measurement. Background technique [0002] The residual gas content of coal seams is an important basic data for predicting mine gas emission, designing coal seam gas drainage, evaluating the compliance of gas drainage, and evaluating the risk of coal seam outburst. At present, the measurement of residual gas in coal samples needs to take the coal samples to the ground laboratory and then crush them for measurement. During this process, the crushing tank has a large mass, is heavy to carry, and takes a long time. In addition, the gas is easily lost during transportation, resulting in a decrease in measurement accuracy. [0003] In the published patent documents, for example, a Chinese invention patent published on Jan...

AI Technical Summary

Problems solved by technology

At present, the determination of residual gas in coal samples needs to take the coal samples to the ground laboratory for crushing and then measure them. During this process, the mass of the crushing tank is large, heavy to carry, and takes a long time. In addition, the gas is easily lost during transportation, resulting in a decrease in measurement accuracy.

[0003] In the published patent documents, for example, a Chinese invention patent published on January 1, 2021, "A device for accurately measuring gas content" with the publication number CN212275388, uses a bottom crushing motor to drive the side wall crushing wheels and crushing blades to classify When crushing coal samples, electric sparks are easily generated during the crushing process, and the structure is complex, and the electric energy required by the equipment cannot be easily obtained underground; a Chinese invention patent published on June 27, 2017 with the publication number CN106896034A "gas loss in the process of crushing coal samples The experimental system in "Experimental System and Method for Mass Measurement" includes crushed coal bunker, briquette bunker, vacuum system, pressure loading system, gas loading system, linear motor control system, digital mass flow meter and gas collection system. The volume is large, the structure is complex, and the operation process is cumbersome and time-consuming, so the measurement results cannot be obtained quickly

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