Dynamic deformation characteristic testing method in coal absorption and desorption process

Abstract

The invention discloses a dynamic deformation characteristic testing method in a coal absorption and desorption process. The method comprises the following steps: (1) measuring empty volumes of a high-pressure air accumulation bottle and a high-pressure absorption and desorption tank; (2) mounting samples; (3) measuring the free space volume of the absorption and desorption tank; (4) implementing the dynamic coal evolutionary process test in a gas isothermal constant-volume absorption process; (5) implementing the dynamic coal evolutionary process test in a gas isothermal constant-pressure absorption process; (6) implementing the absorption-desorption dynamic evolution process test under the gas constant-volume and variable-temperature condition; (7) implementing the dynamic coal evolutionary process test in a gas competitive absorption process; and (8) implementing the dynamic coal evolutionary process test in a gas desorption process. The method is easy to operate; and the accuracy of test results is high.

Description

technical field [0001] The invention relates to a test device and a test method, in particular to a test device and method for measuring coal body deformation in the process of coal body adsorption and desorption of gas. Background technique [0002] The interaction mechanism between coal and gas is a basic scientific issue in the field of gas disaster prevention and control. It not only plays an important guiding role in exploring the mechanism of mine coal-rock gas dynamic disasters, but also provides important technologies for coalbed gas drainage or coalbed methane development. support. Mine gas is generated in the metamorphic stage of coal, and mainly occurs in the state of being adsorbed on the surface of micropores and pressured in the pores and cracks of coal rock mass. The coal body-surrounding rock system is in a relatively static equilibrium state under the joint action of gas pressure and rock mass stress. When underground mining activities enter the coal seam ...

AI Technical Summary

Problems solved by technology

Although these devices are specially developed for measuring the adsorption and desorption deformation of coal bodies, they often cannot meet the requirements in terms of experimental conditions.

For example, the adsorption equilibrium time of the existing equipment is short, and the equilibrium time of most experiments is within 60 hours, and the adsorption deformation test lump coal samples are different from granular coal samples, especially when using raw coal for experiments. The adsorption equilibrium time is much longer, and some need hundreds of hours to reach equilibrium. The existing equipment is restricted by stability and cannot meet this requirement; Within 5.0MPa, and the coal body under high pressure often exhibits different characteristics from that at low pressure, so a test device (0-10.0MPa) that can realize high-pressure adsorption deformation is required; when performing desorption deformation tests, according to actual engineering conditions, It is necessary to test the deformation value of coal samples under different pressure gradients, therefore, it is necessary to provide a controllable ambient pressure for the desorption of gas-containing coal

Similarly, when using different gases with CH 4 Competitive adsorption between CO 2 In coal seam storage, coal bed methane gas injection and other tests, it is also necessary to provide a pressure environment for gas mixing and replacement, which cannot be realized by existing test devices; , both ignore the influence of coal adsorption and desorption deformation on the free space volume, so there is a certain error between the measured adsorption amount and the real adsorption amount

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