Synchronous testing device and method for coal adsorption and desorption deformation anisotropy

Abstract

The invention discloses a synchronous testing device and method for coal adsorption and desorption deformation anisotropy. The method is characterized in that on the basis of experimentally researching coal adsorption and desorption deformation through an existing method, an experimental device composed of a nitrogen cylinder, a helium cylinder, an electromagnetic valve, a pressure sensor, a vacuum pump, a vacuum gauge, a constant-temperature water bath box, an adsorption and desorption tank, a desorption and gas collection device, a resistance strain gauge, a strain gauge and a computer is adopted, an experimental coal sample is put into the adsorption and desorption tank, the electromagnetic valve, the pressure sensor and the constant-temperature water bath box are used for controlling different pressure and temperature conditions, epoxy resin adhesive ensures a sealed environment, a strain data acquisition system is used to carry out anisotropy measurement on desorption deformationof a coal body under different conditions, and an experiment result is automatically recorded by a data processing system. The operation process is trouble-saving and labor-saving, no redundant pipeline connection exists, the loss of excessive gas in the pipeline is avoided, and the device and the method can be suitable for synchronously measuring the stress strain of the coal body in all directions under different air pressure and different temperature conditions in real time.

Description

technical field [0001] The invention belongs to the technical field of coal deformation and strain testing, and in particular relates to a simultaneous testing device and method for coal adsorption and desorption deformation anisotropy. Background technique [0002] Coalbed methane reservoirs in most mining areas in my country have the typical characteristics of "three lows and one strong" of low pressure, low permeability, low saturation and strong heterogeneity, and it is relatively difficult to extract them directly. With continuous mining, many mines have begun to gradually mine deep, and the gas pressure in the coal seam will increase with the deepening of the mining depth, and at the same time the ground stress will also increase, so that the low gas content coal seam has the risk of gas outburst possible. The expansion deformation value of coal adsorbed by gas is affected by multiple factors. Under the same gas pressure, the adsorption expansion deformation value of ou...

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Problems solved by technology

[0004] Summarizing the previous research results, most of the current studies focus on the law of coal adsorption expansion deformation, relatively few studies on desorption shrinkage deformation, and in terms of deformation anisotropy characteristics, most of them focus on the two directions of vertical bedding and parallel bedding In the study of deformation law, due to the difference in the development degree, connectivity and fracture opening of the plane cleats and end cleats parallel to the bedding direction in the coal seam, there is still obvious anisotropy in the parallel bedding direction.

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