Mined-out area air leakage field optimization based coal and gas symbiotic disaster control method

Abstract

The invention discloses a mined-out area air leakage field optimization based coal and gas symbiotic disaster control method. The mined-out area air leakage field optimization based coal and gas symbiotic disaster control method comprises the following steps: A, determining a crack field distribution range of a mined-out area and a rock stratum coated thereon, thereby determining a height range ofa drilled position; B, determining a reasonable gas extraction way according to the crack field distribution range and existing mine geological data; C, determining a drilling field distribution condition; D, monitoring working face gas concentration and CO concentration, and detecting air leaking speed of the mined-out area; E, regulating extraction negative pressure of an extraction main pipeline and setting gas sensing; F, determining coal spontaneous combustion and gas explosion coexistence possibility epsilon of air leakage speed and gas concentration; and G, obtaining practical extraction negative pressure of the coal mine according to the determined safety range. The mined-out area air leakage field optimization based coal and gas symbiotic disaster control method disclosed by theinvention determines extraction negative pressure of a coal bed by considering a mined-out area flow field change condition, so that mined-out area air leakage field is optimized, and therefore, the coal and gas symbiotic disaster control purpose can be realized while gas extraction effect is guaranteed.

Description

technical field [0001] The invention relates to a coal and gas co-occurrence disaster prevention and control method based on the optimization of the air leakage field in the goaf. Background technique [0002] Coal is one of the main energy materials widely used at present, but the gas, fire, water, dust and other disasters during its mining restrict the development of the coal industry. With the increase of mining depth, the gas content and pressure of coal seams continue to increase, and the geothermal gradient increases sharply. A large number of shallow low-gas mines are upgraded to high-gas mines and even mines with coal and gas outbursts. It is a coal seam that is extremely prone to spontaneous combustion, leading to intertwined symbiosis of gas and coal spontaneous combustion disasters. The risk of disasters continues to increase, showing the coupling effect of multiple disasters, and the situation of coal mine safety production is becoming more and more severe. In r...

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Problems solved by technology

Although the above method can prevent both gas overrun and coal spontaneous combustion to a certain extent, it takes a long time to prepare fire prevention materials in the early stage, and the cost is high; and it does not solve the problem of gas drainage in goaf The process will lead to the risk of coal spontaneous combustion, because when the gas is extracted, the flow of air and gas will cause the oxygen concentration and gas temperature in the goaf to change, and when the temperature rises, the flow field will be redistributed. After the flow field is redistributed, the oxygen concentration field and the temperature field will change. This will eventually lead to the spontaneous combustion of the remaining coal in the goaf. The above prevention and control methods do not consider the flow field of the goaf. Easy to cause coal spontaneous combustion disaster

In addition, the above method does not consider the influence of the drainage negative pressure on the drainage effect, that is, if the drainage negative pressure is too low, the gas flow power will be insufficient, and the amount of gas that is allowed to be extracted is small; if the drainage negative pressure is too high, it will easily cause drilling Excessive internal and external pressure differences lead to gas leakage in boreholes, low extraction concentration, waste of negative pressure resources, and a sharp increase in the risk of coal spontaneous combustion

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