Deep true triaxial anisotropic coal rock gas seepage coupling test system and test method

Abstract

The invention discloses a deep true triaxial anisotropic coal rock gas seepage coupling test system which comprises a coal rock holder, a gas inlet and a gas outlet of the coal rock holder are connected with a gas inlet header pipe and an exhaust pipe respectively, the gas inlet header pipe is connected with a vacuumizing pipeline, a three-way device is arranged at the tail end of the gas inlet header pipe, and a gas inlet electronic pressure gauge is arranged on the three-way device. An inlet electronic pressure gauge is connected to the gas inlet main pipe between the vacuumizing pipeline and the gas inlet; an outlet electronic pressure gauge is arranged on the exhaust pipe at the air outlet; the three-way device is connected with a methane branch pipe, a nitrogen branch pipe and a carbon dioxide branch pipe; a gas inlet flow velocity sensor and a gas outlet flow velocity sensor are respectively arranged at the gas inlet header pipe at the gas inlet and the gas outlet; and the coal rock holder is connected with a true triaxial loading system. The invention further discloses a corresponding test method. The coal sample permeability rule under three-field coupling of temperature, pressure and ultrasonic waves is disclosed, the optimal coal seam permeability can be obtained, the practice of coal seam gas extraction is guided, energy supply is increased, and the environment is protected.

Description

technical field [0001] The invention relates to the technical field of coal mines, in particular, a deep true triaxial anisotropic coal-rock gas seepage coupling test device is designed. Background technique [0002] As the mining depth of coal mines continues to increase, most of the mines gradually enter the deep coal seam mining environment. With the change of mining depth, the ground pressure and temperature in different directions gradually increase when the coal seam is excavated, resulting in an increasingly severe mining environment in deep mines. Gas outburst accidents are also on the rise, and accurate knowledge of gas seepage laws in deep coal seams is a prerequisite for preventing gas outburst disasters and building safe coal mines. [0003] The adsorption and desorption of gas in coal seams is closely related to the in-situ stress, ultrasonic vibration and formation temperature of coal seam mining. for a significant impact. [0004] At present, most coal sampl...

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Problems solved by technology

[0004] At present, most coal sample holders only consider the relationship between the coal sample permeability and the in-situ stress field and temperature field, and do not consider the change characteristics of the anisotropy of the internal pores of the coal sample caused by ultrasonic vibration. The measured permeability data often have large errors when the change characteristics of anisotropy are damaged

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