Pumped storage power station transformed from closed kilometer deep coal mine pit

Abstract

The utility model discloses a pumped storage power station formed by reconstruction of a closed kilometer deep well coal mine. The pumped storage power station comprises an upper reservoir, a mine middle layer, a surge chamber, a water diversion tunnel, a tail water tunnel and an underground reservoir. The mine middle layer is provided with a plurality of stages of stepped sub-middle layers in the height direction, and each stage of sub-middle layer is provided with a pump turbine set; the water diversion tunnel is communicated with the upper reservoir and the pump turbine set in each stage of sub-middle layer; the pump turbine set located on the bottommost layer is communicated with the surge chamber, and the surge chamber is communicated with the tail water tunnel and the underground reservoir. The ultra-high water head of the kilometer deep well mine is utilized, and the storage capacity of the upper reservoir and the lower reservoir can be greatly reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of pumped storage power stations, specifically a pumped storage power station converted from a closed-down coal mine shaft at a depth of one kilometer. Background Technology

[0002] A pumped-storage hydroelectric power station is an energy storage facility that uses surplus electricity during off-peak hours to pump water from a low-level reservoir to a high-level reservoir for storage, and releases the hydroelectric energy to generate electricity during peak electricity demand. This technology plays an important regulatory role in modern power systems, particularly for peak shaving, frequency regulation, and emergency backup.

[0003] Pumped-storage hydroelectric power stations use water as a medium. Utilizing their own turbines and pumps, they operate during the night when electricity demand is low, pumping excess electricity from the grid to transfer water from the lower reservoir to the upper reservoir, storing it as potential energy. When daytime and evening electricity demand surges, the generators in the pumped-storage power station begin operating, releasing the water pumped to the upper reservoir at night to generate electricity, replenishing the system's peak capacity and energy. This cycle repeats continuously, using energy conversion to meet the grid's peak-shaving and valley-filling needs.

[0004] Utility model patent CN219431959U discloses a system for pumped-storage energy storage using underground shaft space constructed in coal mine engineering. Utility model patent CN219888189U discloses a pumped-storage power station converted from a closed underground coal mine shaft. This patent addresses the conversion of existing abandoned mines with water heads below 800m into pumped-storage power stations. Both patents design pumped-storage power stations for conventional coal mines, employing single-stage pump-turbine units. However, with technological advancements, the coal mining industry is increasingly venturing deeper into the earth. Conventional closed-shaft pumped-storage power station designs are no longer sufficient for future closed mines at depths of 1000m or even deeper. Furthermore, the excessive water head at 1000m depths can cause severe cavitation in the guide vane mechanism of conventional pump-turbine units, affecting their normal operation. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the current conventional design scheme for pumped storage power stations in closed mines can no longer meet the needs of closed mines at depths of 1,000 meters or even deeper.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] A pumped storage power station converted from a closed-down coal mine at a depth of 1,000 meters includes: an upper reservoir 10, a mine intermediate layer, a surge tank 30, a water diversion tunnel 40, a tailrace tunnel 50, and an underground reservoir 60; the mine intermediate layer is provided with a stepped multi-level sub-intermediate layer in the height direction, and each sub-intermediate layer is equipped with a water pump turbine unit 20.

[0008] The water diversion tunnel 40 connects the upper reservoir 10 and the pump-turbine unit 20 in each intermediate layer; the pump-turbine unit 20 at the bottom layer is connected to the surge tank 30, and the surge tank 30 is connected to the tailrace tunnel 50 and the underground reservoir 60.

[0009] In one embodiment of this utility model, the intermediate layer of the mine is located in a sandstone stratum at the top and bottom of the mine's central chamber. The tailrace tunnel 50 is a bifurcated tunnel, including a horizontal section and an inclined section. The horizontal section is connected to the surge chamber 30, and the inclined section is connected to the underground reservoir 60.

[0010] In one embodiment of this utility model, the inclined section is inclined higher toward the underground reservoir 60 and lower toward the pressure regulating chamber 30.

[0011] In one embodiment of this utility model, the pressure regulating chamber 30 is a water chamber type pressure regulating chamber.

[0012] In one embodiment of this utility model, an anti-surge structure 61 is provided in the underground reservoir 60.

[0013] In one embodiment of this utility model, the pumped storage power station includes a ventilation shaft 70; the underground layer where the intermediate layer of the mine and the underground reservoir 60 are located is connected to the ventilation shaft 70.

[0014] In one embodiment of this utility model, the pumped storage power station includes a traffic shaft 80, a ventilation shaft 70, and the underground layer where the intermediate layer of the mine and the underground reservoir 60 are located.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] Because the excessive water head in a kilometer-deep well can cause severe cavitation in the guide vane mechanism of a conventional pump-turbine unit, thus affecting its normal operation, a multi-stage pump-turbine unit was chosen for the design. Furthermore, for the kilometer-deep well, a stepped, multi-stage sub-intermediate layer was designed to reduce the height difference, with a pump-turbine unit installed in each sub-intermediate layer, thus achieving a multi-stage pump-turbine unit design.

[0017] Meanwhile, in the intermediate layer, the top and bottom of the mine chambers are selected as sandstone sections. Mudstone typically exhibits low strength, high compressibility, and weak shear strength. Under stress, it is prone to deformation and flow, and is easily affected by water, resulting in expansion or contraction. Sandy mudstone has mechanical characteristics between sandstone and mudstone, possessing certain strength and shear resistance, as well as good permeability and air permeability, but it is susceptible to deformation and damage due to water. Sandstone has good strength and stability, making it suitable for various geotechnical engineering projects such as construction, tunnels, and foundations.

[0018] Meanwhile, due to the excessive water head in the kilometer-deep well and the pressure generated when water is pumped from the ground to the ground, the water pipes in the water diversion tunnel are high-pressure water pipes, a water chamber-type pressure regulating chamber is used, the tailrace tunnel is designed as a branching tunnel, and the underground reservoir is equipped with a surge protection structure. The water pipes in the water diversion tunnel are high-pressure water pipes to reduce the impact of water flow.

[0019] This invention utilizes the ultra-high water head of a kilometer-deep mine shaft to greatly reduce the capacity of the upper and lower reservoirs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a pumped storage power station converted from a closed-down coal mine shaft, according to an embodiment of the present invention. Detailed Implementation

[0021] To facilitate understanding of the technical solution of this utility model by those skilled in the art, the technical solution of this utility model will now be further described in conjunction with the accompanying drawings.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] To facilitate understanding of this utility model, some technical terms used in this utility model will be explained beforehand:

[0024] A runway is a horizontal passage dug in mountainous areas during mining operations, such as in mines, shafts, and hydropower exploration. It has a direct exit to the surface and functions similarly to a vertical shaft.

[0025] Side-mounted structure: refers to a type of building structure, usually used for water intake structures on the shore.

[0026] Chambers: Their main uses include installing various equipment and machinery, storing materials and tools, or serving other special purposes such as machine repair rooms, explosives depots, rest rooms, and shelters.

[0027] Please see Figure 1 As shown, this utility model provides a pumped-storage power station converted from a closed-down coal mine at a depth of one kilometer, including an upper reservoir 10, an intermediate layer of the mine, a surge tank 30, a water diversion tunnel 40, a tailrace tunnel 50, and an underground reservoir 60. The intermediate layer of the mine is arranged in a stepped, multi-level sub-intermediate layer along its height, with each sub-intermediate layer equipped with a pump-turbine unit 20. The water diversion tunnel 40 connects the upper reservoir 10 and the pump-turbine units 20 in each sub-intermediate layer. The pump-turbine unit 20 at the bottom level is connected to the surge tank 30, and the surge tank 30 is connected to the tailrace tunnel 50 and the underground reservoir 60.

[0028] In this embodiment, the upper reservoir 10 is located in the surface subsidence area within the coal mine. During power generation, the water from the upper reservoir 10 is drawn through the water diversion tunnel 40 to the pump-turbine unit 20 located in the uppermost intermediate layer, and then flows through the water diversion tunnel 40 to the pump-turbine unit 20 located at the bottom layer. After being drawn by the pump-turbine unit 20 at the bottom layer, the water enters the tailrace system. Taking advantage of the high head, the tailrace is pressure-regulated by the surge tank 30, and then enters the tailrace tunnel 50. The tailrace tunnel 50 reduces the impact on the roadway, and then the water enters the underground reservoir 60.

[0029] In this embodiment, during energy storage, water is successively pumped from the underground reservoir 60 along the tailrace tunnel 50 to the bottom pump turbine unit 20 and the pump turbine unit 20 in the middle layer, and finally pumped to the upper reservoir 10 to complete energy storage.

[0030] In this embodiment, the surface subsidence area of ​​the mine goaf is selected as the upper reservoir 10, and an anti-seepage layer is installed on the inner wall of the upper reservoir 10. The underground reservoir 60 is composed of the roadways and chambers left after the mine is mined. Since the underground reservoir 60 is a roadway, it generally requires anti-seepage and reinforcement construction. The construction steps are: base surface treatment → cement grouting → asphalt concrete coating → crack sealing → JS coating application. The inlet / outlet of both the upper reservoir 10 and the underground reservoir 60 are side-mounted and located at the lowest elevation of their respective adits. Trash screens are installed at the inlet / outlet.

[0031] In this embodiment, the vertical shaft originally located between the upper reservoir 10 and the intermediate layer of the mine is used as a section of the water diversion tunnel 40. The upper reservoir 10 is connected to the water pump turbine unit 20 through the water delivery pipe in the water diversion tunnel 40, wherein the water delivery pipe is selected as a pressure steel pipe.

[0032] In this embodiment, the location of the intermediate layer of the mine is related to the geological structure of the closed mine. The intermediate layer of the mine is connected to the underground reservoir 60 through ventilation shafts for wiring and water pipes. Preferably, the top and bottom of the chamber in the mine are sandstone sections. Appropriate support methods, such as steel frame support and shotcrete support, are selected to reinforce the chamber. At the same time, effective ground pressure control measures are taken, such as reinforcing the chamber structure and arranging the supports reasonably to reduce the impact of ground pressure on the chamber.

[0033] In this embodiment, the selection of the intermediate layer in the mine requires a detailed investigation and analysis of the underground geological conditions of the coal mine. If the original main shaft wall has been permanently reinforced, the planning of the intermediate layer generally involves excavating a new auxiliary shaft next to the main shaft, taking into account the actual underground geological conditions of the coal mine and the location of the pump-turbine unit 20 in the overall plan of the pumped storage power station. If it has not been permanently reinforced, a new intermediate layer can be excavated directly from the original shaft wall, again requiring attention to its geological structure. After the pump-turbine unit 20 is placed in the intermediate layer of the mine, it is connected to the lower reservoir through existing ventilation shafts, transport shafts, etc.

[0034] In this embodiment, the selection of the surge tank 30 is crucial. The function of the surge tank in a mine pumped storage power station is the same as in a conventional hydropower station; it is a hydraulic structure located on a pressure waterway. Its main function is to limit water shock waves from entering the pressure intake / tailrace waterway, meet the technical requirements for the pump-turbine unit 20's regulation and protection, and improve the unit's operational safety during hydraulic transitions. It is primarily suitable for situations where the pressurized waterway is relatively long. In the initial planning and design phases of pumped storage power stations, the surge tank design is often estimated by referring to the form and setting criteria of surge tanks in conventional hydropower stations. Pumped storage power stations built on wells at depths of several kilometers are typical hydropower stations with high head and large reservoir working depths. Since the water chamber type surge tank 30 is suitable for hydropower stations with high head and large reservoir working depths, the water chamber type surge tank is selected.

[0035] In this embodiment, the tailrace tunnel 50 is designed as a bifurcated tunnel, mainly divided into a horizontal section and an inclined section. The horizontal section of the tailrace tunnel 50 is connected to the surge chamber 30, and the inclined section of the tailrace tunnel 50 is connected to the underground reservoir 60. The inclined direction of the inclined section is higher towards the underground reservoir 60 and lower towards the surge chamber 30, thereby further reducing the impact on the tunnel. Subsequently, the water enters the underground reservoir 60.

[0036] In this embodiment, a surge protection structure 61 is provided in the underground reservoir 60. In order to prevent damage to the chamber of the underground reservoir 60 due to excessive water head, a surge protection plan is made for it by widening the tunnel entrance to reduce the impact of water flow.

[0037] In this embodiment, the pumped-storage power station converted from a kilometer-deep coal mine mine closure also includes a ventilation shaft 70 and a access shaft 80. Underground powerhouses are constructed in both the intermediate mine level and the underground level where the underground reservoir 60 is located. These underground powerhouses serve as the work locations for staff monitoring the pumped-storage power station. The underground levels where the intermediate mine level and the underground reservoir 60 are located are connected to the ventilation shaft 70, primarily for moisture protection and safety of the underground powerhouses. The access shaft used for underground production is retained as the access shaft 80 for transporting and installing the equipment and facilities for this pumped-storage power station. The access shaft 80 is connected to the ventilation shaft 70, the intermediate mine level, and the underground level where the underground reservoir 60 is located.

[0038] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] The above-described embodiments are merely examples of implementation methods of the utility model. The scope of protection of this utility model is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and these all fall within the scope of protection of this utility model.

Claims

1. A pumped storage power station, which is reconstructed from a coal mine pit of a kilometer deep mine, characterized in that, Comprise: Upper reservoir (10), mine intermediate layer, surge chamber (30), water diversion tunnel (40), tail water tunnel (50), underground reservoir (60); The mine intermediate layer is provided with a plurality of stepped sub-intermediate layers in the height direction, and each sub-intermediate layer is provided with a water pump water turbine unit (20); The water diversion tunnel (40) is connected with the upper reservoir (10) and the water pump water turbine unit (20) in each sub-intermediate layer; The water pump water turbine unit (20) located in the bottom layer is connected with the surge chamber (30), and the surge chamber (30) is connected with the tail water tunnel (50) and the underground reservoir (60).

2. The kilometer deep coal mine pit closure converted pumped storage power plant of claim 1, wherein, The position of the mine intermediate layer is located in the section of the mine chamber with sandstone top and bottom.

3. The kilometer deep coal mine pit closure converted pumped storage power plant of claim 2, wherein, The tail water tunnel (50) is a bifurcated tunnel, comprising a horizontal section and an inclined section, the horizontal section is connected with the surge chamber (30), and the inclined section is connected with the underground reservoir (60).

4. The pumped storage power station according to claim 3, wherein The inclined direction of the inclined section is high towards the underground reservoir (60) and low towards the surge chamber (30).

5. The kilometer deep coal mine pit reformed into a pumped storage power station according to claim 1, characterized in that, The surge chamber (30) is a water chamber type surge chamber.

6. The pumped storage power plant according to claim 1, wherein The underground reservoir (60) is provided with a surge protection structure (61).

7. The kilometer deep coal mine pit reformed into a pumped storage power station according to claim 1, characterized in that, The pumped storage power station comprises a ventilation shaft (70); The underground layer where the mine intermediate layer and the underground reservoir (60) are located is provided with an underground powerhouse; The ventilation shaft (70) is connected with the underground powerhouse.

8. The kilometer deep coal mine pit reformed into a pumped storage power station according to claim 1, characterized in that, The pumped storage power station comprises a traffic shaft (80), which is connected with the ventilation shaft (70) and the underground layer where the mine intermediate layer and the underground reservoir (60) are located. The pumped storage power station comprises a ventilation shaft (70); The underground layer where the mine intermediate layer and the underground reservoir (60) are located is provided with an underground powerhouse; The ventilation shaft (70) is connected with the underground powerhouse. The pumped storage power station comprises a traffic shaft (80), which is connected with the ventilation shaft (70) and the underground layer where the mine intermediate layer and the underground reservoir (60) are located.

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