Measurement device and method for free expansion volume of coal rock adsorption

Abstract

Belonging to the field of coalbed methane exploitation, the invention discloses a measurement device and method for free expansion volume of coal rock adsorption. The device includes a sample chamber (1), a heating and thermal insulation device (2), a confining pressure tracking pump (3), a back pressure buffer container (4), a liquid holding container (5), a balance (6) and a back pressure valve (7). The sample chamber (1) is fixed in the heating and thermal insulation device (2), the confining pressure tracking pump (3) is connected to an annular space (1-3), the back pressure buffer container (4) is respectively connected to the confining pressure tracking pump (3) and the back pressure valve (7), the other end of the back pressure valve (7) is connected to the annular space (1-3), and the liquid holding container (5) and the balance (6) are placed at another branch outlet. The method measures the mass of liquid discharged by coal sample expansion deformation and then performs conversion to obtain the expansion quantity and expansion coefficient of coal rock. With the device and the method provided by the invention, the free expansion volume and expansion coefficient of the coal rock sample can be obtained, the measurement accuracy is high, and no complicated conversion is needed.

Description

technical field [0001] The invention relates to a device and method for measuring the free expansion volume of coal rocks, in particular to a method for measuring the adsorption of CH in coal rocks in a laboratory. 4 , CO 2 , N 2 The invention relates to a measuring device and method for the free expansion volume of competitively adsorbed multi-component gas in coal rock or other gases, belonging to the field of coal bed methane exploitation. Background technique [0002] my country has abundant coalbed methane resources, and the development of coalbed methane is of great significance to alleviate the tension of my country's oil and gas resources, reduce the degree of mine disasters, and reduce greenhouse gas emissions. Coal rock mass is a porous medium containing a large amount of adsorbed coalbed methane, and its mechanical properties have an important impact on coalbed methane mining. A large number of studies have proved that the coal matrix adsorbed N 2 , CH 4 , CO...

AI Technical Summary

Problems solved by technology

While coal adsorbs CH 4 , CO 2 , N 2 Etc gas or the expansion volume of multi-component gas competitively adsorbed in coal or through indirect methods to measure the stress change and then convert it into strain, or directly monitor the strain of some points in the sample, and calculate the overall deformation, which cannot be obtained. True, comprehensive and accurate free expansion volume and expansion coefficient of samples

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