Pipeline cut-off device and method for realizing underground coal gasification mobile gas injection

Abstract

The invention relates to the technical field of underground coal gasification, in particular to a pipeline cut-off device for realizing underground coal gasification mobile gas injection, which comprises a gas delivery pipe positioned in a gas injection drill hole and formed by connecting a plurality of gas injection pipe sections, and every two adjacent gas injection pipe sections form a group of gas injection pipes. Each group of gas injection pipes are fixedly connected through a connecting ring, the middles of the two gas injection pipe sections of each group are connected through a cutting device body, the cutting device body is composed of clamping rings, a high-temperature-resistant spring and a hot melting ring, and the clamping rings are arranged on the inner walls of the gas injection pipe sections on the left side and the right side of the cutting device body correspondingly; a high-temperature-resistant spring in a compressed state is connected between the clamping rings in an abutting mode, the gas injection pipe sections provided with the clamping rings are fixedly connected through a hot melting ring, when a flame working face reaches the hot melting ring, the hot melting ring is broken to form a new gas injection hole, and the new gas injection hole provides a gasification agent for gasification reaction. The invention further provides a pipeline cutting-off method for achieving coal underground gasification mobile gas injection.

Description

technical field [0001] The invention relates to the technical field of underground coal gasification, in particular to a pipeline cutting device and method for realizing mobile gas injection of underground coal gasification. Background technique [0002] Underground coal gasification is a process in which coal in the ground is burned in a controlled manner to generate combustible gas through thermal and chemical effects on coal. Underground gasification technology only extracts the energy-containing components in coal, and changes physical coal mining into chemical coal mining, realizing the integration of the three major processes of well construction, coal mining and surface gasification, eliminating the need for huge coal mining, Transportation, washing, gasification and other processes and equipment, so it has the advantages of good safety, less investment, high efficiency, less pollution, etc., and is known as the second-generation coal mining method. UCG technology ca...

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Problems solved by technology

[0007]Although the existing technical solutions can also realize the hot-melt bolt disconnection and cutting off the pipeline, the structure of the device is relatively complicated, the cost is high, and the installation of gas injection drilling is required At the same time, the inner protective pipe needs to be connected by a concave flange. This connection method is not conducive to the installation of the gas injection pipeline in the gas injection borehole in the underground coal gasifier. The raised flange edge will increase the The installation resistance in the air drilling hole may even get stuck in the air injection drilling hole and it is difficult to install successfully; and the length of the embedded spring in the concave flange is limited by the size of the concave flange, the number of spring coils is small, and the elastic force is small , it is difficult to pop open two adjacent gas injection pipelines; the snap-in connector is directly connected through the buckle, and the seal is not tight, resulting in gas leakage from the gas injection pipeline at the position of the open connector, causing the gas injection channel to be filled with oxygen, resulting in reverse combustion of the coal fire , it is easy to cause the hot-melt elastic connector on the entire gas injection pipeline to be disconnected by heat, which will cause the device to fail, and it is difficult to achieve the effect of mobile gas injection

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