Experimental system and method for water-gas two-phase seepage of gas-containing coal

Abstract

The invention discloses a gas-containing coal-water-gas two-phase seepage experimental system and method. The experimental system mainly includes a gas mixing device, and the gas mixing device includes a mixing tank and an adsorption tank connected in sequence. There is a liquid collection port; the outlet of the mixing tank is respectively connected to the water vapor delivery pipeline and the high-pressure gas delivery pipeline; the adsorption tank is connected to the air inlet of the coal sample holder, and the gas outlet pipeline of the coal sample holder It is divided into two branches through the four-way valve, one of which is connected to the vacuum pump, and the other is connected to the water vapor metering device and the gas flow meter in sequence. For the first time, the experimental system uses the coordinated movement of water vapor and gas phase to realize the two-phase permeation behavior of water and gas in gas-containing coal. At the same time, the real-time continuous data acquisition device can accurately observe the changes in the permeability and water content of gas-containing coal. It has the advantages of easy operation and accurate measurement; it overcomes the problem that it is difficult to directly mix liquid water and gas.

Description

technical field [0001] The present invention relates to a gas-containing coal seepage experiment technology under the condition of water-gas two-phase medium with different loads, different temperatures, different water contents and different gas pressures, and is a gas-containing coal-water gas simulation technology for real coal mine environmental conditions. Two-phase seepage experimental system and method. Background technique [0002] The adsorption-desorption-seepage characteristics of gas in coal seams are affected by many factors such as coal seam gas pressure, ground stress, coal physical and mechanical properties, surrounding rock structure, groundwater and ground temperature, especially as the depth of coal mining deepens year by year. The multi-factor coupling relationship is more obvious. In the past, gas-containing coal-water-gas two-phase adsorption-desorption-seepage experiment system used liquid water for experiments. Since liquid water and gas gas were dif...

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Problems solved by technology

In the past, gas-containing coal-water-gas two-phase adsorption-desorption-seepage experiment system used liquid water for experiments. Since liquid water and gas gas were difficult to mix uniformly, it was impossible to achieve true water-gas two-phase seepage flow.

[0003] The domestic published patent document CN201210409446.0 discloses a gas-containing coal-water two-phase adsorption-desorption-seepage experimental system and method, which can be used under different constant external loading pressures and different gas pressures. The two-phase adsorption-desorption-seepage experiment of gas-containing coal, but does not consider the influence of liquid water on the seepage characteristics of coal, nor the influence of temperature on the experiment; the published patent document CN201210283984.X discloses a temperature-variable The gas-containing coal adsorption-desorption-seepage experimental system is loaded under the conditions. This set of test equipment has relatively complete functions. It can not only realize the comprehensive effect of various influencing factors on the seepage characteristics of gas-containing coal, but also consider the influence of temperature on the experiment. Good progress has been made, but the influence of liquid water on the seepage characteristics of coal is still not overcome

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