Method for pumped storage using abandoned open-pit mines and underground mines

Abstract

The present invention relates to the field of abandoned mine reuse and pumped storage, and specifically to a method for pumped storage using abandoned open-pit mines and underground mines; the method comprises the following steps: a. constructing auxiliary adit and grouting boreholes from the wellbore, and grouting to reinforce the collapsed zone and the water-conducting fracture zone; the auxiliary adit is located in the thick hard rock layer above the water-conducting fracture zone; b. constructing an upper diversion tunnel from the wellbore to the collapse pit; c. constructing a tailwater tunnel from the wellbore to the open-pit mine; d. constructing an upper reservoir and a lower reservoir. Subsequently, a surge chamber and an electromechanical chamber are constructed; and then the grouting boreholes and the auxiliary adit are closed. Finally, the wellbore portion above the upper diversion tunnel is closed, and the upper diversion tunnel, the tailwater tunnel, and the wellbore section between the two connect the upper reservoir and the lower reservoir. The present invention can carry out multiple construction processes in parallel, reduce the construction workload of the upper and lower reservoirs, ensure the stability of the upper reservoir constructed based on the collapse pit, and greatly reduce the construction period and cost.

Description

Technical Field

[0001] The present invention relates to the field of abandoned mine reuse and pumped water storage, and in particular to a method for pumped water storage by combining abandoned open-pit mines with underground mines. Background Art

[0002] A pumped-storage power station primarily consists of an upper reservoir, a diversion tunnel, and a lower reservoir. During peak power loads, water from the lower reservoir is pumped to the upper reservoir to store potential energy. During low power loads, the water from the upper reservoir is released to the lower reservoir to release potential energy and convert it into electricity. The selection of upper and lower reservoirs is crucial when constructing a pumped-storage power station. Choosing a natural river valley or other valley as the foundation for either reservoir can significantly reduce construction time and costs.

[0003] Currently, research has explored the construction of upper and lower reservoirs based on abandoned open-pit mines or abandoned goafs, tunnels, and sinkholes in underground mines. However, this research is largely limited to pumped-storage power plants constructed within open-pit mines or goafs and tunnels in underground mines. However, some mines, both domestically and internationally, utilize a combination of open-pit and underground mining methods, or have close proximity between open-pit and underground mines, such as the Xinling Coal Mine, the Fuxin Haizhou Coal Mine, and the Jianlong Iron Mine. Under these circumstances, the question of how to comprehensively consider the abandoned mines created by both mining methods when selecting the sites for various pumped-storage power plant components and rapidly and concurrently construct these power plants has become a pressing technical challenge in this field. Summary of the Invention

[0004] In response to the above technical problems, the present invention proposes a method for pumped storage using abandoned open-pit mines and underground mines. The abandoned underground mine is on the left, and the open-pit pit of the abandoned open-pit mine is on the right. The coal seam mined in the open-pit mine is relatively shallow, and the shaft of the abandoned underground mine is located between the abandoned underground mine and the abandoned open-pit mine. The method includes the following steps:

[0005] a. Determine the height of the water-conducting fracture zone after mining of the underground coal seam and the location of all thick hard rock layers above the water-conducting fracture zone; select a certain thick hard rock layer at a certain distance above the water-conducting fracture zone, construct an auxiliary flat tunnel from the wellbore along the selected thick hard rock layer to the left, and build a grouting station near the wellbore in the auxiliary flat tunnel; continue to construct the auxiliary flat tunnel, and when construction reaches above the collapse zone and the water-conducting fracture zone, construct grouting holes from the auxiliary flat tunnel downward to the collapse zone and the water-conducting fracture zone, use the grouting station to prepare grouting slurry, and inject the grouting slurry into the collapse zone and the water-conducting fracture zone through the grouting holes; continue to construct the auxiliary flat tunnel and construct grouting holes at set intervals to the collapse zone and the water-conducting fracture zone and inject grouting until the entire collapse zone and the water-conducting fracture zone are completely filled with grouting;

[0006] b. Construction of a diversion tunnel from the shaft to the collapse pit;

[0007] c. Construction of tailwater tunnel from shaft to open pit;

[0008] d. Construct the upper reservoir based on the collapsed pit and the lower reservoir based on the lower part of the open pit;

[0009] Step a, step b, step c, and step d are performed simultaneously;

[0010] e. Construct surge chambers and seal grouting holes and auxiliary flat holes with crushed stone or grouting at grouting stations;

[0011] At the same time, the electromechanical chamber is constructed;

[0012] At the same time, an upper trash rack is constructed at the connection between the upper diversion tunnel and the shaft, and a lower trash rack is constructed at the connection between the tailrace tunnel and the lower reservoir;

[0013] f. In the wellbore, the wellbore section above the upper diversion tunnel is closed, and the upper diversion tunnel, tailrace tunnel and the wellbore section between the two connect the upper reservoir and the lower reservoir.

[0014] Preferably, in step a, the grouting slurry is prepared by grinding crushed stone produced during the construction of the auxiliary adit, the upper diversion tunnel and the tailwater tunnel into crushed stone powder and mixing the powder with water to prepare the grouting slurry.

[0015] Preferably, in step b, the waste rock generated during construction is transported to the grouting station in the auxiliary adit using the hoisting system of the wellbore.

[0016] Preferably, in step c, the waste rock generated during construction first fills the shaft portion below the tailwater tunnel, and then is transported to the grouting station in the auxiliary adit using the shaft's own hoisting system.

[0017] Preferably, in step e, a surge chamber is constructed at the intersection of the auxiliary adit and the shaft; and an electromechanical chamber is constructed at the intersection of the tailwater tunnel and the shaft.

[0018] The beneficial effects of the present invention are as follows: 1. The present invention can use the shaft of an abandoned underground mine to simultaneously carry out the following construction processes: a. Construction of auxiliary flat tunnels and grouting drilling, grouting reinforcement of collapsed zones and water-conducting fracture zones; b. Construction of an upper water diversion tunnel; c. Construction of a tailwater tunnel; d. Construction of an upper reservoir and a lower reservoir; in this way, multiple processes can be constructed in parallel, greatly reducing the construction period and cost.

[0019] 2. The present invention uses the collapse pit formed by underground mining as the basis for constructing the upper reservoir and the open pit as the basis for constructing the lower reservoir, which can reduce the construction workload of the upper and lower reservoirs.

[0020] 3. The present invention uses the crushed stone produced during the construction of the upper water diversion tunnel, auxiliary adit, and tailwater tunnel as grouting material, and utilizes the existing hoisting system of the wellbore for lifting, thereby reducing the work of handling the crushed stone and saving costs; and grouting to reinforce the collapsed zone and the water-conducting fracture zone can ensure the stability of the upper reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 2. It is a cross-sectional schematic diagram of the basic conditions of the method for pumped storage energy by combining abandoned open-pit mines with underground mines according to the present invention;

[0022] Figure 2 This is a cross-sectional schematic diagram of the construction process of the pumped storage method using abandoned open-pit mines and underground mines in combination;

[0023] Figure 3 This is a cross-sectional diagram of the completed construction of the pumped storage method using abandoned open-pit mines and underground mines;

[0024] In the figure, there is an underground coal seam 11; a collapsed zone 12; a water-conducting fracture zone 13; a subsidence pit 14; a ground surface 15; an open pit 16; a shaft 17; a grouting borehole 21; a grouting station 22; an auxiliary adit 23; an upper reservoir 31; an upper trash rack 32; an upper diversion tunnel 331; a tailrace tunnel 332; an electromechanical chamber 34; a lower trash rack 35; a lower reservoir 36; and a surge chamber 37. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 As shown, it is a cross-sectional schematic diagram of the method of combining abandoned open-pit mines and underground mines for pumped storage energy according to the present invention. On the left is the abandoned underground mine. The underground coal seam 11 has been mined, and some coal pillars remain. The overlying rock strata of the mined part of the underground coal seam 11 have collapsed and sunk, forming a collapse zone 12, a water-conducting fracture zone 13 and a curved sinking zone from bottom to top. A collapse pit 14 is formed on the surface 15 of the uppermost part of the curved sinking zone; on the right side of the abandoned underground mine is the open-pit pit 16 of the abandoned open-pit mine. The coal seam mined in the open-pit mine is relatively shallow, and the underground coal seam 11 is relatively deep. The shaft 17 of the abandoned underground mine is located between the abandoned underground mine and the abandoned open-pit mine.

[0027] Combined with the terrain conditions and the existing research, it can be seen that the bottom of the open pit 16 can be used as the foundation for the construction of the lower reservoir, and the collapse pit 14 can be used as the foundation for the construction of the upper reservoir. However, there is residual compression space between the collapsed and broken rocks in the collapse zone 12 at the bottom of the collapse pit 14 and the water-conducting fracture zone 13, which will cause the collapse pit 14 to form long-term residual sinking. However, the collapse pit 14 needs to be stable as the upper reservoir 31, so it is necessary to reinforce the collapse zone 12 and the water-conducting fracture zone 13. The existing collapse zone 12 The water-conducting fracture zone 13 is often reinforced by grouting. However, if grouting drilling and grouting reinforcement are carried out from the collapse pit 14, the construction of the upper reservoir will be affected. If the collapse zone 12 and the water-conducting fracture zone 13 can be reinforced by grouting at the same time without affecting the construction of the upper reservoir, and the construction of the water diversion tunnel can be carried out, the construction speed of the pumped storage power station can be accelerated, and the construction period and construction cost can be reduced. In this regard, the present invention proposes a method for combining abandoned open-pit mines with underground mines for pumped storage, which includes the following steps:

[0028] a. Figure 2 As shown, the height of the water-conducting fracture zone 13 after the mining of the underground coal seam 11 is determined, and the positions of all thick hard rock layers above the water-conducting fracture zone 13 are determined; a certain thick hard rock layer is selected at a certain distance above the water-conducting fracture zone 13, and an auxiliary horizontal tunnel 23 is constructed to the left along the selected thick hard rock layer from the wellbore 17, and a grouting station 22 is built near the wellbore 17 at the auxiliary horizontal tunnel 23; the auxiliary horizontal tunnel 23 is continued to be constructed, and when the construction reaches above the collapse zone 12 and the water-conducting fracture zone 13, a grouting borehole 21 is constructed downward from the auxiliary horizontal tunnel 23 to the collapse zone 12 and the water-conducting fracture zone 13. The grouting station 22 is used to prepare grouting slurry, which is injected into the collapsed zone 12 and the water-conducting fracture zone 13 through the grouting borehole 21; the auxiliary adit 23 is continuously constructed, and grouting boreholes 21 are constructed at set intervals to the collapsed zone 12 and the water-conducting fracture zone 13, and grouting is performed until the entire collapsed zone 12 and the water-conducting fracture zone 13 are filled with grouting; wherein the grouting slurry is prepared by grinding the crushed stone generated during the construction of the auxiliary adit 23, the upper water diversion tunnel 331, and the tailrace tunnel 332 into crushed stone powder and mixing it with water to prepare the grouting slurry;

[0029] b. Figure 2 As shown, an upper diversion tunnel 331 is constructed from the shaft 17 to the collapse pit 14 in a substantially horizontal manner (the shaft 17 side may be slightly lower). The upper diversion tunnel 331 connects the collapse pit 14 (later upper reservoir 31) and the shaft 17. The waste rock generated during construction is transported to the grouting station 22 in the auxiliary adit 23 using the hoisting system of the shaft 17.

[0030] c. Figure 2As shown, a tailwater tunnel 332 is constructed in a substantially horizontal manner from the shaft 17 to the open pit 16. The tailwater tunnel 332 connects the open pit 16 (later lower reservoir 36) and the shaft 17. The waste rock 21 generated during construction first fills the shaft 17 below the tailwater tunnel 332 and is then transported to the grouting station 22 in the auxiliary adit 23 using the hoisting system of the shaft 17.

[0031] d. Figure 2 As shown, an upper reservoir 31 is constructed based on the collapsed pit 14, and a lower reservoir 36 is constructed based on the lower part of the open pit 16;

[0032] Step a, step b, step c, and step d are performed simultaneously;

[0033] e. Figure 3 As shown, a surge chamber 37 is constructed at the intersection of the auxiliary adit 23 and the shaft 17, the grouting borehole 21 is sealed with crushed stone or grouting is performed at the grouting station 22, and the auxiliary adit 23 is sealed with crushed stone or grouting is performed at the grouting station 22;

[0034] At the same time, an electromechanical chamber 34 is constructed at the intersection of the tailwater tunnel 332 and the shaft 17;

[0035] At the same time, an upper trash rack 32 is constructed at the connection between the upper diversion tunnel 331 and the shaft 17, and a lower trash rack 35 is constructed at the connection between the tailwater tunnel 332 and the lower reservoir 36;

[0036] f. In the wellbore 17 , the wellbore 17 portion above the diversion tunnel 331 is closed, and the diversion tunnel 331 , the tailrace tunnel 332 and the wellbore section therebetween connect the upper reservoir 31 and the lower reservoir 36 .

[0037] Among them, in step e, the pressure regulating chamber 37 and the electromechanical chamber 34 are the preferred embodiments recommended by this specific embodiment. Those skilled in the art can adjust and select the positions of the pressure regulating chamber 37 and the electromechanical chamber 34 according to technical needs, construction needs, etc., which all fall within the scope of protection of the present invention.

[0038] Of course, the above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above-mentioned embodiments. It should be noted that all equivalent substitutions and obvious deformation forms made by any technician familiar with this field under the guidance of this specification fall within the substantive scope of this specification and should be protected by the present invention.

Claims

1. A method for combining abandoned open-pit mines and underground mines for pumped storage. The abandoned underground mine is on the left. After the underground coal seam is mined, a collapse zone, a water-conducting fracture zone, and a curved sinking zone are formed from bottom to top. A collapse pit is formed on the surface of the uppermost part of the curved sinking zone. The open-pit pit of the abandoned open-pit mine is on the right. The shaft of the abandoned underground mine is located between the abandoned underground mine and the abandoned open-pit mine. It is characterized by: The steps include: a. Determine the height of the water-conducting fracture zone after mining of the underground coal seam and the location of all thick hard rock layers above the water-conducting fracture zone; select a thick hard rock layer above the water-conducting fracture zone, construct an auxiliary flat tunnel from the wellbore along the selected thick hard rock layer to the left, and build a grouting station near the wellbore in the auxiliary flat tunnel; continue to construct the auxiliary flat tunnel, and when construction reaches above the collapse zone and the water-conducting fracture zone, construct grouting holes from the auxiliary flat tunnel downward to the collapse zone and the water-conducting fracture zone, use the grouting station to prepare grouting slurry, and inject the grouting slurry into the collapse zone and the water-conducting fracture zone through the grouting holes; continue to construct the auxiliary flat tunnel and construct grouting holes at set intervals to the collapse zone and the water-conducting fracture zone and inject grouting until the entire collapse zone and the water-conducting fracture zone are completely filled with grouting; b. Construction of a diversion tunnel from the shaft to the bottom of the collapse pit; c. Construction of tailwater tunnel from shaft to open pit; d. Construct the upper reservoir based on the collapsed pit and the lower reservoir based on the lower part of the open pit; Crushed stone generated during the construction of the auxiliary adit, upper diversion tunnel and tailrace tunnel is used as grouting material; Step a, step b, step c, and step d are performed simultaneously; e. Construct surge chambers and seal grouting holes and auxiliary flat holes with crushed stone or grouting at grouting stations; At the same time, the electromechanical chamber is constructed; At the same time, an upper trash rack is constructed at the connection between the upper diversion tunnel and the shaft, and a lower trash rack is constructed at the connection between the tailrace tunnel and the lower reservoir; f. In the wellbore, the wellbore section above the upper diversion tunnel is closed, and the upper diversion tunnel, tailrace tunnel and the wellbore section between the two connect the upper reservoir and the lower reservoir.

2. The method for pumped storage of water by combining abandoned open-pit mines with underground mines according to claim 1 is characterized in that: In step b, the waste rock generated during construction is transported to the grouting station in the auxiliary adit using the wellbore's own lifting system.

3. The method for pumped storage of water by combining abandoned open-pit mines with underground mines according to claim 2 is characterized in that: In step c, the waste rock generated during construction first fills the shaft below the tailwater tunnel, and is then transported to the grouting station in the auxiliary adit using the shaft's own hoisting system.

4. The method for pumped storage of energy by combining abandoned open-pit mines with underground mines according to claim 3 is characterized in that: In step a, the grouting slurry is prepared by grinding the crushed stones generated during the construction of the auxiliary adit, the upper diversion tunnel and the tailwater tunnel into crushed stone powder and mixing the powder with water to prepare the grouting slurry.

5. The method for pumped storage of water by combining abandoned open-pit mines with underground mines according to claim 4 is characterized in that: In step e, a surge chamber is constructed at the intersection of the auxiliary adit and the shaft; and an electromechanical chamber is constructed at the intersection of the tailwater tunnel and the shaft.

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