A coal thermal co-mining method based on tunnel-by-tunnel cementation filling

Abstract

The invention relates to the technical field of coal mining, and discloses a coal-heat co-mining method based on lane-by-lane cementing and filling, comprising the following steps: dividing a coal seam area to be mined into a plurality of mutually spaced narrow strips and wide strips; mining a plurality of the narrow strips in sequence from a cutting position of a working face; filling the mined narrow strips according to the mining sequence of the narrow strips, so that the filling forms an isolation waterproof wall; mining a plurality of the wide strips according to the filling sequence of the narrow strips; filling the mined wide strip area to form a mine water storage / heat extraction space; constructing retaining walls at both ends of the filled wide strips, and installing a water inlet pipe and a water outlet pipe on two opposite retaining walls; the coal-heat co-mining method based on lane-by-lane cementing and filling realizes the coordinated mining of coal and geothermal energy, simplifies the construction steps of installing pipelines in the heat exchange space, improves the coordinated mining efficiency of coal and geothermal energy, and can also effectively solve the problem of resource disposal of coal-based solid waste.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a coal-thermal co-mining method based on lane-by-lane cementing filling. Background Art

[0002] Deep mine geothermal resources are rich and are not affected by external factors such as seasons and day and night changes. They are very high-quality green renewable energy. In the past, high temperatures in deep mines were an important factor causing poor working conditions for underground workers. However, in recent years, society has gradually regarded deep mine geothermal as a recoverable energy source, and finding a suitable mining method is crucial.

[0003] When conducting geothermal mining in deep mines, it is necessary to ensure a stable underground space. The current concept of geothermal mining in deep mines is still mainly based on the idea of ​​hot dry rock enhanced heat extraction system, which extracts heat by installing pipes and heat exchangers in the coal seam. This geothermal collection method is applied to geothermal mining in deep mines. The overall construction steps are cumbersome, which leads to low efficiency in geothermal energy extraction.

[0004] In view of this, the present invention proposes a coal-thermal co-mining method based on tunnel-by-tunnel cementing filling. Summary of the invention

[0005] The present invention proposes a coal-geothermal co-mining method based on tunnel-by-tunnel cementing and filling, which realizes the coordinated mining of coal and geothermal energy, simplifies the construction steps, and improves the mining efficiency of geothermal energy, so as to solve the shortcomings of the above-mentioned prior art.

[0006] The technical solution of the present invention is: a coal thermal co-mining method based on lane-by-lane cementing filling, comprising the following steps:

[0007] S1: Divide the coal seam area to be mined into a number of narrow and wide strips spaced apart from each other;

[0008] S2: mining a plurality of the narrow strips in sequence from the cutting position of the working face;

[0009] S3: filling the mined narrow strips according to the mining sequence of the narrow strips, so that the fillings form an isolation waterproof wall;

[0010] S4: mining the plurality of wide strips in sequence from the cutting position of the working face according to the filling order of the narrow strips;

[0011] S5: Fill the mined wide strip area to form a mine water storage / heat extraction space within the wide strip;

[0012] S6: Build water retaining walls at both ends of the filled wide strip, and install water inlet pipes and water outlet pipes on the two opposite water retaining walls respectively; the water inlet pipe is used to fill cold water into the mine water storage / heat extraction space, and the water outlet pipe is used to extract water heated by the mine water storage / heat extraction space to realize geothermal collection; multiple water inlet pipes are connected to a main water inlet pipe; multiple water outlet pipes are all connected to a main water outlet pipe.

[0013] In at least one embodiment of the present disclosure, after the first narrow strip mining is completed, the mining space is filled so that the filling material isolates the waterproof wall. When more than two isolation waterproof walls form supporting strength, the wide strip area between the two isolation waterproof walls is mined.

[0014] In at least one embodiment of the present disclosure, the width of the narrow strip is 2 to 4 m, and the width of the wide strip is 6 to 8 m.

[0015] In at least one embodiment of the present disclosure, the isolation waterproof wall is made of waterproof concrete, and the strength of the isolation waterproof wall is greater than 3 times the vertical ground stress at the location of the isolation waterproof wall; the isolation waterproof wall serves as the structural wall of the mine water storage / heat extraction space, and is also the supporting wall of the underground space during geothermal mining in deep mines.

[0016] In at least one embodiment of the present disclosure, the mine water storage / heat extraction space is filled with gangue bulk material or gangue-based high-porosity cementitious filling material; by filling the mine water storage / heat extraction space with gangue bulk material or gangue-based high-porosity cementitious filling material, mine solid waste materials are consumed on site, thereby achieving the purpose of large-scale and high-resource treatment of mine solid waste, bringing good economic benefits to the mine.

[0017] In at least one embodiment of the present disclosure, the water inlet pipe is installed near the top of the water retaining wall, and the water outlet pipe is installed near the bottom of the water retaining wall; this arrangement can facilitate the heat exchange medium (such as water) to flow from the water inlet pipe to the water outlet pipe, so that the heat exchange medium can quickly and fully contact the filler in the mine water storage / heat extraction space.

[0018] In at least one embodiment of the present disclosure, the narrow strip is close to the coal mine cut to be mined, and the narrow strip close to the coal mine cut to be mined adopts concrete film bags or backboards to form a closed concrete pouring space.

[0019] The present invention is a coal-thermal co-mining method based on lane-by-lane cementing filling. First, narrow strips of the working face are mined at intervals and filled with high-strength waterproof materials; secondly, wide strips between the narrow strips are mined and filled with materials with good permeability; then, waterproof retaining walls are constructed at both ends of the filled wide strips; finally, a water inlet pipeline is installed on one side of the waterproof retaining wall, and a water pumping pipeline is installed on the other side of the waterproof retaining wall.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention provides a coal-heat co-mining method based on tunnel-by-tunnel cementing filling. The method divides the coal seam area to be mined into a plurality of narrow strips and wide strips spaced apart from each other, and fills the narrow strips with high-strength waterproof materials, and fills the wide strips with materials with good permeability to form a mine water storage / heat extraction space. Compared with the current geothermal mining method, the method avoids the installation of heat extraction pipes or heat exchangers inside the coal seam or filling body, simplifies the construction steps, improves the mining efficiency of geothermal energy, and saves the cost of engineering construction and subsequent maintenance.

[0022] 2. The present invention provides a coal-geothermal co-mining method based on tunnel-by-tunnel cementing filling. After the first narrow strip mining is completed, the mining space is filled. When more than two isolation waterproof walls form supporting strength, the wide strip area between the two isolation waterproof walls is mined. On the basis of forming sufficient support, the coordinated mining efficiency of coal geothermal energy is improved.

[0023] 3. The present invention provides a coal-heat co-mining method based on lane-by-lane cementing filling, in which the heat exchange medium (such as water) used is in direct contact with the heat storage body, with a large contact area and high heat exchange efficiency.

[0024] 4. The present invention provides a coal-thermal co-mining method based on tunnel-by-tunnel cementing filling. The filling materials used are mainly composed of coal-based solid waste such as coal gangue and fly ash. It can consume mine solid waste materials on site, effectively solve the problem of solid waste resource disposal, and bring good economic and environmental benefits to the mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a top plan view of the working surface of the present invention.

[0026] Figure 2 It is a cross-sectional view of the top plane of the working surface of the present invention along the AA direction.

[0027] Figure 3 It is a cross-sectional view of the working surface of the present invention in the direction of the top plane BB.

[0028] Description of reference numerals:

[0029] 1. Narrow strip; 2. Wide strip; 3. Isolation waterproof wall; 4. Mine water storage / heat extraction space; 5. Transport tunnel; 6. Return air tunnel; 7. Water inlet pipe; 8. Water outlet pipe; 9. Cutting eye; 10. Water retaining wall. DETAILED DESCRIPTION

[0030] The drawings in this disclosure are not drawn strictly according to the actual scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in this disclosure are only schematic diagrams of the structures.

[0031] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0032] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "up", "down", "far", "near", "front", "back" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] The current concept of geothermal mining in deep mines is still mainly based on the idea of ​​hot dry rock enhanced heating system, which extracts heat by installing pipes and heat exchangers in coal seams. However, since geothermal mining in deep mines requires a stable underground space, this geothermal collection method is applied to geothermal mining in deep mines. The overall construction steps are cumbersome, which leads to low geothermal energy extraction efficiency. Geothermal mining in deep mines requires a stable underground space, and the currently widely used coal filling mining can maintain a stable heating space after coal mining.

[0034] In view of this, the present invention proposes a coal-heat co-mining method based on tunnel-by-tunnel cementing filling, which realizes the coordinated mining of coal and geothermal energy, simplifies the construction steps of installing pipelines in the heat exchange space, and can also effectively solve the problem of resource disposal of coal-based solid waste.

[0035] Combination Figures 1 to 3 As shown, a coal thermal co-mining method based on tunnel-by-tunnel cementing filling comprises the following steps:

[0036] S1: Divide the coal seam area to be mined into a plurality of mutually spaced narrow strips 1 and wide strips 2;

[0037] S2: mining the coal in the plurality of narrow strips 1 in sequence from the cutting position of the working face;

[0038] S3: filling the mined narrow strip 1 according to the mining sequence of the narrow strip 1 so that the filling forms an isolation waterproof wall 3, and the narrow strip 1 is filled with a high-strength waterproof material;

[0039] S4: mining the plurality of wide strips 2 in sequence from the cutting position of the working face according to the filling order of the narrow strips 1;

[0040] S5: Filling the mined wide strip 2 area to form a mine water storage / heat extraction space 4 in the wide strip 2; the wide strip 2 is filled with a material with good permeability;

[0041] S6: Build water retaining walls 10 at both ends of the filled wide strip 2, the water retaining walls 10 are connected to the narrow strips 1 on the adjacent two sides, and install water inlet pipes 7 and water outlet pipes 8 on the two opposite water retaining walls 10; the water inlet pipe 7 is used to fill cold water into the mine water storage / heat extraction space 4, and the water outlet pipe 8 is used to extract water heated by the mine water storage / heat extraction space 4 to achieve geothermal collection; multiple water inlet pipes 7 are connected to a main water inlet pipe; multiple water outlet pipes 8 are all connected to a main water outlet pipe;

[0042] Specifically, the water outlet pipe 8 is located in the return air tunnel 6 , and the water inlet pipe 7 is located in the transport tunnel 5 .

[0043] As an alternative embodiment, after the first narrow strip 1 is mined, the mining space is filled so that the filling material forms an isolation waterproof wall 3. When more than two isolation waterproof walls 3 form supporting strength, the wide strip 2 area between the two isolation waterproof walls 3 is mined; on the basis of forming sufficient support, the coordinated mining efficiency of coal geothermal energy is improved.

[0044] As an alternative embodiment, the width of the narrow strip 1 is 2-4 m, and the width of the wide strip 2 is 6-8 m.

[0045] As an alternative embodiment, the isolation waterproof wall 3 is made of waterproof concrete, and the strength of the isolation waterproof wall 3 is greater than 3 times the vertical ground stress at the location of the isolation waterproof wall 3; the isolation waterproof wall 3 serves as the structural wall of the mine water storage / heat extraction space 4, and is also the supporting wall of the stable underground space during geothermal mining in deep mines.

[0046] As an alternative embodiment, the mine water storage / heat extraction space 4 is filled with gangue bulk material or gangue-based high-porosity cementitious filling material; by filling the mine water storage / heat extraction space 4 with gangue bulk material or gangue-based high-porosity cementitious filling material, mine solid waste materials are consumed on site, thereby achieving the purpose of large-scale and high-resource treatment of mine solid waste, bringing good economic benefits to the mine.

[0047] As an alternative embodiment, the water inlet pipe 7 is installed near the top of the water retaining wall 10; the water outlet pipe 8 is installed near the bottom of the water retaining wall 10; this arrangement can facilitate the heat exchange medium (such as water) to flow from the water inlet pipe 7 to the water outlet pipe 8, so that the heat exchange medium can quickly and fully contact the filler in the mine water storage / heat extraction space 4.

[0048] As an alternative embodiment, the narrow strip 1 is close to the coal mine cutout 9 to be mined, and the narrow strip 1 close to the coal mine cutout 9 uses concrete membrane bags or backboards to form a closed concrete pouring space; the selection of the concrete membrane bags or backboards can make the structural strength of the narrow strip 1 close to the coal mine cutout 9 to be mined higher, thereby avoiding accidents of collapse of the narrow strip 1.

[0049] The above embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above embodiments, ordinary technicians in this field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions for implementing the present invention, and should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A coal thermal co-mining method based on tunnel-by-tunnel cementing filling, characterized in that: The following steps are involved: S1: Divide the coal seam area to be mined into a plurality of mutually spaced narrow strips (1) and wide strips (2); S2: mining a plurality of the narrow strips (1) in sequence from the cutting position of the working face; S3: filling the mined narrow strip (1) according to the mining sequence of the narrow strip (1) to form an isolation waterproof wall (3); S4: mining the plurality of wide strips (2) in sequence from the cutting position of the working face according to the filling order of the narrow strips (1); after the first narrow strip (1) is mined, the mining space is filled so that the filling material forms an isolation waterproof wall (3); when two or more isolation waterproof walls (3) form a supporting strength, the wide strip (2) area between the two isolation waterproof walls (3) is mined; S5: filling the mined wide strip (2) area to form a mine water storage / heat extraction space (4) within the wide strip (2); S6: constructing water retaining walls (10) at both ends of the filled wide strip (2), and installing a water inlet pipe (7) and a water outlet pipe (8) on two opposite water retaining walls (10) respectively.

2. A coal thermal co-mining method based on lane-by-lane cementing filling as claimed in claim 1, characterized in that: The width of the narrow strip (1) is 2 to 4 m, and the width of the wide strip (2) is 6 to 8 m.

3. The method for coal thermal co-mining based on tunnel-by-tunnel cementing filling as claimed in claim 1, characterized in that: The material of the isolation waterproof wall (3) is waterproof concrete, and the strength of the isolation waterproof wall (3) is greater than 3 times the vertical ground stress at the location of the isolation waterproof wall (3).

4. The method for coal thermal co-mining based on lane-by-lane cementing filling as claimed in claim 1, characterized in that: The mine water storage / heat extraction space (4) is filled with gangue bulk material or gangue-based high-porosity cemented filling material.

5. The method for coal thermal co-mining based on tunnel-by-tunnel cementing filling as claimed in claim 1, characterized in that: The water inlet pipe (7) is installed close to the top of the water retaining wall (10), and the water outlet pipe (8) is installed close to the bottom of the water retaining wall (10).

6. The method for coal thermal co-mining based on tunnel-by-tunnel cementing filling as claimed in claim 1, characterized in that: The narrow strip (1) is close to the coal mine cutout (9) to be mined, and the narrow strip (1) close to the coal mine cutout (9) to be mined adopts a concrete film bag or a back plate to form a closed concrete pouring space.

Images