Gas three-dimensional seepage simulation device and simulation method in closed goaf

Abstract

The invention discloses a closed goaf mashgas three-dimensional seepage simulation device and a simulation method thereof, and belongs to the technical field of closed goaf mashgas seepage simulation. The device comprises a sealed box body, a permeability rate control system, a mashgas release system, a mashgas exhausting and mining system and a data acquisition system. The interior of the sealed box body adopts a high-rebound sponge for simulating a porous medium in a closed goaf; a cylinder array applies the pressure on the high-rebound sponge for controlling a distribution characteristic of the goaf permeability rate; methane is injected into different horizons of the sealed box body by the mashgas release system, to simulate different mashgas release sources; a steel slim tube is used for simulating a ground drilling well, and a wind speed sensor, a pipeline pressure sensor and a methane concentration sensor are adopted for monitoring the mashgas exhausting and mining amount and the mashgas exhausting and mining concentration of the simulated drilling well; a barograph and a methane concentration recorder are arranged for monitoring the gas pressure and the mashgas concentration of the interior of the simulated goaf. The device and the method can change a simulation scheme according to actual conditions, and have universal applicability.

Description

technical field [0001] The invention relates to a gas seepage simulation device and a simulation method thereof, belonging to the technical field of gas seepage simulation in closed goafs. Background technique [0002] In coal mining operations, with the continuous advancement of the coal mining face, the overlying coal strata behind the working face continue to sink and break, forming a goaf. There are two types of goafs: semi-closed goafs and closed goafs. The semi-closed goaf always exists behind the coal mining face during mining, and is connected with the mine ventilation system; the closed goaf refers to the goaf where the movement of the overlying strata is stable after the working face is closed, and is isolated in the mine. outside the ventilation system. Within the scope of the goaf, mining pressure relief gas is continuously desorbed and released, and accumulates in large quantities in the goaf. During the normal mining of the working face, part of the gas accu...

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Problems solved by technology

[0004] The shortcomings of using this method or the points that need to be improved are: (1) If materials such as gypsum, calcium carbonate, river sand, mica powder and coal powder are used as similar materials for each rock formation, the formed goaf has a permeability distribution. (2) During the mining process of the simulated working face, once the simulated rock formation collapses and is damaged, it cannot be reused; (3) The existing semi-closed goaf gas seepage simulation experimental device cannot be used to seal the gas in the goaf. Seepage simulation, the gas seepage simulation device in the closed goaf has not yet been made public

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