Method for arranging tail water of pumped storage power station crossing large active fault

Abstract

The tail water arrangement method of the pumped storage power station crossing large active faults comprises the following steps: determining the position of the lower reservoir according to the position and related data of the active fault, and determining the position of the upper reservoir in combination with the distance ratio and related data; determining the position of the main powerhouse according to the distance between the upper and lower reservoirs and related data; determining the tail water line; the tail water line comprises tail water tunnels, tail water forebays and tail water open channels connected in sequence, and the tail water open channel crosses the active fault; and the water delivery system is reviewed and adjusted to ensure that the pump turbine operates in a region with better speed regulation performance. The tail water arrangement method of the pumped storage power station has the advantages that the tail water open channel is connected with the tail water tunnels and the lower reservoir, the open channel crosses the fault at a large angle, the influence of the active fault is reduced, the seismic safety is improved, the method is suitable for the terrain and landform in the northwest region, the length of the tail water line is shortened, the engineering investment is reduced, the engineering safety is ensured, the arrangement method is simple, safe and reliable, and convenient for maintenance.

Description

Technical Field

[0001] This invention belongs to the technical field of pumped storage power stations, and relates to a tailrace arrangement method for pumped storage power stations that cross large active faults. Background Technology

[0002] The construction of pumped storage power stations in Northwest China has developed rapidly. However, due to plate tectonics since the Cenozoic era, the region has experienced numerous active faults and high seismic intensity, meaning that most pumped storage power station constructions in Northwest China will encounter active faults. According to relevant regulations, "dams and other water-retaining structures should not be built on known active faults." The general principle for dealing with active faults is to avoid them, and a certain avoidance distance must be maintained. When the power line cannot avoid them and must pass through, appropriate crossing measures are required. The layout of the pumped storage power station has a significant impact on the overall project investment. Generally, the approach of crossing active faults is more economical, but it increases technical risks.

[0003] Currently, most pumped-storage power stations crossing active faults opt for tunnels or exposed steel pipe tunnels. However, these crossing methods still have certain drawbacks. For example, most existing tunnel lining structures resist the adverse effects of active faults by increasing stiffness through grouting, leaving a clearance deformation layer between the excavation face and the upper part of the tunnel, setting up an energy dissipation and vibration reduction layer at the bottom, or installing expansion joints in exposed steel pipes inside the tunnel. These measures are difficult to adapt to the large deformation of active faults during earthquakes, leading to maintenance difficulties. Summary of the Invention

[0004] The purpose of this invention is to provide a tailrace arrangement method for pumped storage power stations that cross large active faults, which solves the problem that existing crossing schemes are difficult to adapt to the large deformation of active faults during earthquakes, leading to maintenance difficulties.

[0005] The technical solution adopted in this invention is a tailrace arrangement method for pumped storage power stations traversing large active faults, specifically implemented according to the following steps:

[0006] Step 1: Determine the location of the lower reservoir based on the location of the active fault and relevant data, and then determine the location of the upper reservoir by combining the distance-to-height ratio and relevant data;

[0007] Step 2: Determine the location of the main plant based on the distance between the upper and lower reservoirs and relevant data;

[0008] Step 3: Based on the location of the main plant and the downstream reservoir and related data, the tailrace route is determined; the tailrace route includes a tailrace tunnel, a tailrace forebay, and a tailrace open channel arranged sequentially between the main plant and the downstream reservoir and interconnected with each other. The tailrace open channel passes through an active fracture.

[0009] Step 4: Verify the adjustment and assurance of the water conveyance system to ensure that the water pump and turbine operate in a region with good speed regulation performance.

[0010] The invention is further characterized by:

[0011] In step 1, the relevant data includes: topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions;

[0012] The lower reservoir is located on the hanging wall of an active fault. The distance between the lower reservoir's dam and the active fault must meet the following conditions: if the lower reservoir's dam is located on the hanging wall of an active fault, the distance between the dam and the active fault must be no less than 400m; if the lower reservoir's dam is located on the footwall of an active fault, the distance between the dam and the active fault must be no less than 600m.

[0013] In step 2, the main plant is located deep in the mountain, far from active faults, while meeting the requirements for regulation and ensuring safety and reducing the length of auxiliary caverns.

[0014] The bottom elevation of the tailrace channel is the same as that of the reservoir bottom. The angle between the tailrace channel axis and the direction of the active fault is not less than 60°. The excavation slope ratio of the tailrace channel is 1:1.4 to 1.7.

[0015] In step 3, the height difference between the bottom elevation of the tailrace forebay and the bottom elevation of the tailrace open channel is calculated using the formula for calculating the submersion depth of the inlet, and the tailrace forebay and the tailrace open channel are connected by a sloping transition.

[0016] Downstream inlet / outlet is arranged in the tailrace forebay. The distance between the downstream inlet / outlet and the active fracture is greater than 50m. The downstream inlet / outlet is connected to the main powerhouse through the tailrace tunnel. The downstream inlet / outlet is connected to the tailrace tunnel and the tailrace open channel.

[0017] The tailrace tunnel consists of an upper horizontal section and a lower horizontal section, which are connected by a ramp, inclined shaft, or vertical shaft. The axis of the upper horizontal section, the axis of the tailrace forebay, and the axis of the tailrace open channel are all consistent. The upper horizontal section is connected to the downstream inlet / outlet.

[0018] A tailrace tunnel maintenance gate chamber is located near the downstream inlet / outlet of the tailrace tunnel.

[0019] A water-retaining gate is located at the junction of the tailrace channel and the lower reservoir. A tailgate chamber is located downstream of the main powerhouse. A main transformer room is located between the main powerhouse and the tailgate chamber.

[0020] An emergency venting pipe is installed inside the reservoir.

[0021] In step 4, a tailrace surge chamber is installed near the main powerhouse in the tailrace tunnel.

[0022] The beneficial effects of this invention are:

[0023] 1) The tailrace arrangement method of the pumped storage power station crossing a large active fault of the present invention connects the tailrace tunnel and the lower reservoir through a tailrace open channel. The open channel crosses the fault at a large angle to reduce the range of influence of the active fault on the open channel. The lower reservoir is placed on the upper plate of the active fault and its excavation-fill balance performance is ensured. The main powerhouse is placed deep in the mountain. This not only allows the pumped storage power station to cross the active fault, but also ensures that the lower reservoir dam, downstream inlet / outlet, and main powerhouse are far away from the active fault, reducing the impact of the active fault and increasing seismic safety. The arrangement method conforms to the topography of Northwest China, which can significantly shorten the tailrace line length, reduce project investment, and ensure project safety. It is suitable for the construction of pumped storage power stations and the development of new energy in Northwest China, and can also significantly improve the speed of production and construction.

[0024] 2) The use of an unpressurized tailrace open channel crossing an active fault can reduce the excavation slope ratio of the tailrace open channel, lower construction risks, and ensure the stability of the bank slope under significant water level changes. A sluice gate is installed at the junction of the tailrace open channel and the lower reservoir to ensure the rapid cutoff of water flow between the upper reservoir and the tailrace open channel, and between the tailrace open channel and the lower reservoir during an earthquake. The bottom slab of the tailrace open channel is at the same height as the bottom slab of the lower reservoir, and an emergency venting pipe is installed in the lower reservoir. In the event of a destructive earthquake, the water flow between the upper and lower reservoirs can be quickly cut off, and the water in the lower reservoir and the open channel can be quickly discharged. After the earthquake, the tailrace open channel can be quickly repaired to restore the function of the pumped storage power station as soon as possible, minimizing losses. Maintenance conditions are easy to guarantee, the layout is simple, and it is safe and reliable. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the tailrace arrangement method of the pumped storage power station that crosses a large active fault according to the present invention.

[0026] Figure 2 This is the present invention. Figure 1 A sectional view.

[0027] In the diagram, 1. Main powerhouse, 2. Main transformer room, 3. Tailgate chamber, 4. Tailwater surge chamber, 5. Tailwater tunnel, 6. Tailwater tunnel maintenance gate chamber, 7. Downstream inlet / outlet, 8. Tailwater open channel, 9. Water gate, 10. Lower reservoir, 11. Emergency vent pipe, 12. Movable fracture, 13. Tailwater forebay. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] The tailrace arrangement method of the pumped storage power station traversing a large active fault according to the present invention is implemented in the following steps:

[0030] Step 1: Determine the location of the lower reservoir 10 based on the location of the active fault 12, topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions. Determine the location of the upper reservoir based on the location of the lower reservoir 10, the distance-to-height ratio, and relevant data.

[0031] The lower reservoir 10 is located on the hanging wall of the active fault 12. The distance between the dam of the lower reservoir 10 and the active fault 12 satisfies the following conditions: if the dam of the lower reservoir 10 is located on the hanging wall of the active fault 12, the distance between the dam and the active fault 12 is not less than 400m; if the dam of the lower reservoir 10 is located on the footwall of the active fault 12, the distance between the dam and the active fault 12 is not less than 600m.

[0032] An emergency venting pipe 11 is installed inside the lower reservoir 10. The emergency venting pipe should be short in length, have a small amount of excavation, and a small land acquisition area.

[0033] Step 2: Determine the location of the main plant 1 based on the distance between the upper and lower reservoirs 10 and relevant data;

[0034] The main plant 1 is located deep in the mountain, as far away from the active fault 12 as possible, while meeting the requirements for regulation and ensuring stability and reducing the length of the auxiliary caverns.

[0035] Step 3: Determine the tailrace route based on the location of the main plant 1 and the downstream reservoir 10 and related data;

[0036] The tailrace route of the pumped storage power station includes a tailrace tunnel 5, a tailrace forebay 13, and a tailrace open channel 8, which are connected in sequence. The tailrace open channel 8 is connected to the lower reservoir 10, and the tailrace tunnel 5 is connected to the main powerhouse 1.

[0037] The tailrace channel 8 is arranged according to the relative relationship between the lower reservoir 10 and the active fault 12. The bottom elevation of the tailrace channel 8 is the same as the bottom elevation of the lower reservoir 10, so as to ensure that the water in the lower reservoir and the tailrace channel can be discharged in case of emergency.

[0038] The tailrace open channel 8 passes through the active fracture 12 at a large angle, ensuring that the angle between the axis of the tailrace open channel 8 and the direction of the active fracture 12 is not less than 60°, and minimizing the slope height of the tailrace open channel.

[0039] The tailrace open channel 8 has an excavation slope ratio of 1:1.4 to 1.7, which makes excavation and support simple and reduces construction risks. The top of the tailrace open channel 8 is connected to the external road, which facilitates transportation and makes it easier for later operation, inspection and maintenance.

[0040] A tailrace forebay 13 is arranged at the outlet of tailrace tunnel 5. The height difference between the bottom elevation of tailrace forebay 13 and the bottom elevation of tailrace open channel 8 is calculated using the formula for calculating the submersion depth of the inlet. Furthermore, the tailrace forebay 13 and tailrace open channel 8 are connected by a sloping transition, which can ensure the submersion depth of the outlet of tailrace tunnel 5 and prevent air suction funnels from appearing at the outlet of tailrace tunnel 5 and the downstream inlet / outlet 7.

[0041] A downstream inlet / outlet 7 is arranged in the tailrace forebay 13, and the distance between the downstream inlet / outlet 7 and the movable fracture 12 is greater than 50m; the downstream inlet / outlet 7 connects the tailrace tunnel 5 and the tailrace open channel 8.

[0042] Tailwater Tunnel 5 comprises an upper horizontal section and a lower horizontal section. The connection between the upper and lower horizontal sections is determined by the elevation difference and horizontal distance, and is achieved through a ramp, inclined shaft, or vertical shaft. The elevation of the upper horizontal section is determined by adding 0.5 times the diameter of the tailwater tunnel 5 to the elevation of the bottom plate of the downstream inlet / outlet 7. The axis of the upper horizontal section of the tailwater tunnel 5, the axis of the tailwater forebay 13, and the axis of the tailwater open channel 8 are all consistent, and intersect the direction of the active fault 12 at a large angle, which ensures that the length of the tailwater open channel 8 affected by the active fault 12 is as short as possible.

[0043] A tailrace tunnel maintenance gate chamber 6 is located near the downstream inlet / outlet 7 of the tailrace tunnel 5 to ensure that the water flow between the upper reservoir and the tailrace open channel 8 is cut off in the event of an earthquake.

[0044] A water-blocking gate 9 is installed at the junction of the tailrace channel 8 and the lower reservoir 10 to ensure that the water flow between the tailrace channel 8 and the lower reservoir 10 is cut off in the event of an earthquake. Due to the scarcity of water resources and high evaporation in the Northwest region, as much water as possible is stored in the lower reservoir 10 to avoid waste of water resources;

[0045] The main transformer room 2 is set between the main plant 1 and the tail gate room 3.

[0046] Step 4: Verify the regulation and assurance of the water conveyance system to ensure that the pump turbine operates in a region with good speed regulation performance. A tailrace surge chamber 4 is arranged near the main powerhouse 1 in the tailrace tunnel 5. The tailrace surge chamber 4 can be set up as needed based on the water conveyance system's regulation and assurance requirements.

[0047] Downstream of the main plant 1, there is a tailrace chamber 3, which can quickly lower the tailrace emergency gate in the event of an earthquake shutdown. After the tailrace tunnel water flow tends to stop, the tailrace tunnel maintenance gate is lowered to prevent water from the upper reservoir from entering the tailrace open channel 8 and to prevent water from the upper reservoir from leaking through the tailrace open channel 8.

[0048] The present invention relates to a tailrace arrangement method for a pumped storage power station that traverses a large active fault. When an earthquake of intensity above the design intensity occurs, the tailrace channel 8, which traverses the active fault 12, is likely to be damaged. The relevant operation mode is as follows: First, shut down the pump turbine and close the emergency gate of the tailrace pipe in the tailrace chamber 3; after the water in the tailrace tunnel 5 has become relatively still, close the gate of the tailrace tunnel maintenance chamber 6 to isolate the water between the upper reservoir and the tailrace channel 8; close the water-retaining gate 9 of the tailrace channel 8 to isolate the water between the tailrace channel 8 and the lower reservoir 10; then use a mobile pump to drain the water in the tailrace channel 8 and carry out maintenance on the tailrace channel 8.

[0049] If the tailrace channel 8 is severely damaged, open the emergency vent pipe 11 to drain the water from the reservoir 10, and at the same time open the water gate 9 of the tailrace channel 8 to create a dry construction environment for the repair of the tailrace channel 8.

[0050] The present invention discloses a tailrace arrangement method for a pumped storage power station traversing a large active fault. Its advantages include: connecting the tailrace tunnel 5 and the lower reservoir 10 via a tailrace open channel 8; the tailrace open channel 8 traversing the active fault 12 at a large angle to reduce the influence range of the open channel on the active fault 12; placing the lower reservoir 10 on the upper plate of the active fault 12 and ensuring good excavation-fill balance performance; and placing the main powerhouse 1 deep within the mountain, which not only allows traversal of the active fault 12 but also ensures that the pumped storage power station's lower reservoir 10 dam, downstream inlet / outlet 7, and main powerhouse 1 are as far away from the active fault 12 as possible, reducing its impact and ensuring good seismic performance. The arrangement method conforms to the topography of Northwest China, significantly shortening the water conveyance system length, reducing project investment, ensuring project safety, and is suitable for the construction of pumped storage power stations and the development of new energy sources in Northwest China. It can also significantly improve the speed of production and construction.

[0051] The use of an unpressurized tailrace open channel 8 crossing the active fault 12 can reduce the excavation slope ratio of the open channel, lower construction risks, and ensure the stability of the bank slope under significant water level changes. A water gate 9 is installed at the junction of the tailrace open channel 8 and the lower reservoir 10 to ensure the rapid cutoff of water flow between the tailrace open channel 8 and the lower reservoir during an earthquake. The bottom plate of the tailrace open channel 8 is at the same height as the bottom plate of the lower reservoir 10. An emergency vent pipe 11 is installed in the lower reservoir 10. In the event of a destructive earthquake, the water flow between the upper and lower reservoirs can be quickly cut off, and the water in the lower reservoir and the open channel can be quickly discharged. After the earthquake, the tailrace open channel 8 can be quickly repaired to restore the function of the pumped storage power station as soon as possible, minimizing losses. Maintenance conditions are easy to guarantee, the layout is simple, and it is safe and reliable.

[0052] Example 1

[0053] The tailrace arrangement method of the pumped storage power station traversing a large active fault according to the present invention is implemented in the following steps:

[0054] Step 1: Determine the location of the lower reservoir 10 based on the location of the active fault 12, topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions. Determine the location of the upper reservoir based on the location of the lower reservoir 10, the distance-to-height ratio, and relevant data.

[0055] The lower reservoir 10 is located on the hanging wall of the active fault 12. The distance between the dam of the lower reservoir 10 and the active fault satisfies the following conditions: if the dam of the lower reservoir 10 is located on the hanging wall of the active fault 12, the distance between the dam and the active fault is not less than 400m; if the dam of the lower reservoir 10 is located on the footwall of the active fault 12, the distance between the dam and the active fault 12 is not less than 600m.

[0056] An emergency venting pipe 11 is installed inside the lower reservoir 10.

[0057] Step 2: Determine the location of the main plant 1 based on the distance between the upper and lower reservoirs 10 and relevant data;

[0058] The main plant 1 is located deep in the mountain, as far away from the active fault 12 as possible, while meeting the requirements for regulation and ensuring stability and reducing the length of the auxiliary caverns.

[0059] Step 3: Determine the tailrace route based on the location of the main plant 1 and the downstream reservoir 10 and related data;

[0060] The tailrace line of the pumped storage power station includes a tailrace tunnel 5, a tailrace forebay 13, and a tailrace open channel 8 connected in sequence. The tailrace open channel 8 is connected to the lower reservoir 10, and the tailrace tunnel 5 is connected to the main powerhouse 1.

[0061] Tailwater channel 8 is arranged according to the location of the lower reservoir 10 and the active fault 12. The bottom elevation of tailwater channel 8 is the same as the bottom elevation of the lower reservoir 10.

[0062] The tailrace open channel 8 passes through the active fracture 12 at a large angle, ensuring that the angle between the axis of the tailrace open channel 8 and the direction of the active fracture 12 is 80°, and minimizing the slope height of the tailrace open channel.

[0063] The tailrace open channel 8 has an excavation slope ratio of 1:1.5, which makes excavation and support simple and reduces construction risks. The top of the tailrace open channel 8 is connected to the external road, which facilitates transportation and makes it easier for later operation, inspection and maintenance.

[0064] A tailrace forebay 13 is arranged at the outlet of tailrace tunnel 5. The height difference between the bottom elevation of tailrace forebay 13 and the bottom elevation of tailrace open channel 8 is calculated using the formula for calculating the submersion depth of the inlet. The bottom elevation of tailrace forebay 13 is 13m lower than the bottom elevation of tailrace open channel 8. Furthermore, the tailrace forebay 13 and tailrace open channel 8 are connected by a sloping transition, which can ensure the submersion depth of the outlet of tailrace tunnel 5 and prevent air suction funnels from appearing at the outlet of tailrace tunnel 5 and the downstream inlet / outlet 7.

[0065] A downstream inlet / outlet 7 is arranged in the tailrace forebay 13, and the distance between the downstream inlet / outlet 7 and the movable fracture 12 is 80m; the downstream inlet / outlet 7 is connected to the main powerhouse 1 through the tailrace tunnel 5.

[0066] Tailwater Tunnel 5 includes an upper horizontal section and a lower horizontal section. The downstream inlet / outlet 7 connects to the upper horizontal section. The upper and lower horizontal sections are connected by an inclined shaft. The elevation of the upper horizontal section is determined by the elevation of the bottom plate of the downstream inlet / outlet 7 plus 0.5 times the diameter of the tailwater tunnel. The elevation of the lower horizontal section is usually determined by the elevation of the bottom plate of the tailwater pipe plus 0.5 times the diameter of the tailwater tunnel 5. The axis of the upper horizontal section of the tailwater tunnel 5, the axis of the tailwater forebay 13, and the axis of the tailwater open channel 8 are all consistent and intersect at a large angle with the direction of the active fault 12.

[0067] Tailwater tunnel maintenance gate chambers 6 are located at both the downstream inlet / outlet 7 and the tailwater tunnel 5.

[0068] A water-blocking gate 9 is installed at the junction of the tailrace channel 8 and the lower reservoir 10;

[0069] The main transformer room 2 is set between the main plant 1 and the tail gate room 3.

[0070] Step 4: Verify the water conveyance system's regulation and ensure that the pump turbine operates in a region with good speed regulation performance. A tailrace surge chamber 4 is located in the tailrace tunnel 5 near the main powerhouse 1.

[0071] Tailgate chamber 3 is located downstream of the main plant 1.

[0072] Example 2

[0073] The tailrace arrangement method of the pumped storage power station traversing a large active fault according to the present invention is implemented in the following steps:

[0074] Step 1: Determine the location of the lower reservoir 10 based on the location of the active fault 12, topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions. Determine the location of the upper reservoir based on the location of the lower reservoir 10, the distance-to-height ratio, and relevant data.

[0075] The lower reservoir 10 is located on the hanging wall of the active fault 12, and the dam of the lower reservoir 10 is located on the footwall of the active fault 12. The distance between the dam and the active fault 12 is 1000m.

[0076] An emergency venting pipe 11 is installed inside the lower reservoir 10.

[0077] Step 2: Determine the location of the main plant 1 based on the distance between the upper and lower reservoirs 10 and relevant data;

[0078] The main plant 1 is located deep in the mountain, as far away from the active fault 12 as possible, while meeting the requirements for regulation and ensuring stability and reducing the length of the auxiliary caverns.

[0079] Step 3: Determine the tailrace route based on the location of the main plant 1 and the downstream reservoir 10 and related data;

[0080] The tailrace line of the pumped storage power station includes a tailrace tunnel 5, a tailrace forebay 13, and a tailrace open channel 8 connected in sequence. The tailrace open channel 8 is connected to the lower reservoir 10, and the tailrace tunnel 5 is connected to the main powerhouse 1.

[0081] Tailwater channel 8 is arranged according to the location of the lower reservoir 10 and the active fault 12. The bottom elevation of tailwater channel 8 is the same as the bottom elevation of the lower reservoir 10.

[0082] The tailrace open channel 8 passes through the active fracture 12 at a large angle, ensuring that the angle between the axis of the tailrace open channel 8 and the direction of the active fracture 12 is 70°, and minimizing the slope height of the tailrace open channel.

[0083] The tailrace open channel 8 has an excavation slope ratio of 1:1.4, which makes excavation and support simple and reduces construction risks. The top of the tailrace open channel 8 is connected to the external road, which facilitates transportation and makes it easier for later operation, inspection and maintenance.

[0084] A tailrace forebay 13 is arranged at the outlet of tailrace tunnel 5. The height difference between the bottom elevation of tailrace forebay 13 and the bottom elevation of tailrace open channel 8 is calculated using the formula for calculating the submersion depth of the inlet. Furthermore, the tailrace forebay 13 and tailrace open channel 8 are connected by a sloping transition, which can ensure the submersion depth of the outlet of tailrace tunnel 5 and prevent air suction funnels from appearing at the outlet of tailrace tunnel 5 and the downstream inlet / outlet 7.

[0085] A downstream inlet / outlet 7 is arranged in the tailrace forebay 13, and the distance between the downstream inlet / outlet 7 and the movable fracture 12 is 70m. The downstream inlet / outlet 7 is connected to the lower reservoir 10, and the downstream inlet / outlet 7 is connected to the main powerhouse 1 through the tailrace tunnel 5.

[0086] Tailwater Tunnel 5 comprises an upper horizontal section and a lower horizontal section. The downstream inlet / outlet 7 connects to the upper horizontal section. The upper and lower horizontal sections are connected by a ramp. The elevation of the upper horizontal section is determined by adding 0.5 times the diameter of the tailwater tunnel to the elevation of the bottom plate of the downstream inlet / outlet 7. The axis of the upper horizontal section of Tailwater Tunnel 5, the axis of the tailwater forebay 13, and the axis of the tailwater open channel 8 are all consistent, and intersect at a large angle with the trend of the active fault 12.

[0087] A tailrace tunnel maintenance gate chamber 6 is located near the downstream inlet / outlet 7 of the tailrace tunnel 5.

[0088] A water-blocking gate 9 is installed at the junction of the tailrace channel 8 and the lower reservoir 10;

[0089] The main transformer room 2 is set between the main plant 1 and the tail gate room 3.

[0090] Step 4: Verify the water conveyance system's regulation and ensure that the pump turbine operates in a region with good speed regulation performance. A tailrace surge chamber 4 is located in the tailrace tunnel 5 near the main powerhouse 1.

[0091] Tailgate chamber 3 is located downstream of the main plant 1.

[0092] Example 3

[0093] The tailrace arrangement method of the pumped storage power station traversing a large active fault according to the present invention is implemented in the following steps:

[0094] Step 1: Determine the location of the lower reservoir 10 based on the location of the active fault 12, topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions. Determine the location of the upper reservoir based on the location of the lower reservoir 10, the distance-to-height ratio, and relevant data.

[0095] The lower reservoir 10 is located on the hanging wall of the active fault 12, and the dam of the lower reservoir 10 is located on the hanging wall of the active fault 12. The distance between the dam and the active fault 12 is 800m.

[0096] An emergency venting pipe 11 is installed inside the lower reservoir 10.

[0097] Step 2: Determine the location of the main plant 1 based on the distance between the upper and lower reservoirs 10 and relevant data;

[0098] The main plant 1 is located deep in the mountain, as far away from the active fault 12 as possible, while meeting the requirements for regulation and ensuring stability and reducing the length of the auxiliary caverns.

[0099] Step 3: Determine the tailrace route based on the location of the main plant 1 and the downstream reservoir 10 and related data;

[0100] The tailrace line of the pumped storage power station includes a tailrace tunnel 5, a tailrace forebay 13, and a tailrace open channel 8 connected in sequence. The tailrace open channel 8 is connected to the lower reservoir 10, and the tailrace tunnel 5 is connected to the main powerhouse 1.

[0101] Tailwater channel 8 is arranged according to the location of the lower reservoir 10 and the active fault 12. The bottom elevation of tailwater channel 8 is the same as the bottom elevation of the lower reservoir 10.

[0102] The tailrace open channel 8 passes through the active fracture 12 at a large angle, ensuring that the angle between the axis of the tailrace open channel 8 and the direction of the active fracture 12 is 75°, and minimizing the slope height of the tailrace open channel.

[0103] The tailrace open channel 8 has an excavation slope ratio of 1:1.7, which makes excavation and support simple and reduces construction risks. The top of the tailrace open channel 8 is connected to the external road, which facilitates transportation and makes it easier for later operation, inspection and maintenance.

[0104] A tailrace forebay 13 is arranged at the outlet of tailrace tunnel 5. The height difference between the bottom elevation of tailrace forebay 13 and the bottom elevation of tailrace open channel 8 is calculated using the formula for calculating the submersion depth of the inlet. Furthermore, the tailrace forebay 13 and tailrace open channel 8 are connected by a sloping transition, which can ensure the submersion depth of the outlet of tailrace tunnel 5 and prevent air suction funnels from appearing at the outlet of tailrace tunnel 5 and the downstream inlet / outlet 7.

[0105] Downstream inlet / outlet 7 is arranged in the tailrace forebay 13, and the distance between downstream inlet / outlet 7 and active fracture 1 is 60m. Downstream inlet / outlet 7 is connected to the lower reservoir 10 through tailrace open channel 8, and downstream inlet / outlet 7 is connected to the main powerhouse 1 through tailrace tunnel 5.

[0106] Tailwater Tunnel 5 includes an upper horizontal section and a lower horizontal section. The downstream inlet / outlet 7 is connected to the upper horizontal section. The upper and lower horizontal sections are connected by a vertical shaft. The elevation of the upper horizontal section is determined by the elevation of the bottom plate of the downstream inlet / outlet 7 plus 0.5 times the diameter of the tailwater tunnel. The axis of the upper horizontal section of tailwater tunnel 5, the axis of the tailwater forebay 13, and the axis of the tailwater open channel 8 are all consistent and intersect at a large angle with the direction of the active fault 12.

[0107] A tailrace tunnel maintenance gate chamber 6 is located near the downstream inlet / outlet 7 of the tailrace tunnel 5.

[0108] A water-blocking gate 9 is installed at the junction of the tailrace channel 8 and the lower reservoir 10;

[0109] The main transformer room 2 is set between the main plant 1 and the tail gate room 3.

[0110] Step 4: Verify the water conveyance system's regulation and ensure that the pump turbine operates in a region with good speed regulation performance. A tailrace surge chamber 4 is located in the tailrace tunnel 5 near the main powerhouse 1.

[0111] Tailgate chamber 3 is located downstream of the main plant 1.

Claims

1. A tailrace arrangement method for a pumped storage power station traversing a large active fault, characterized in that, The specific steps are as follows: Step 1: Determine the location of the lower reservoir (10) based on the location of the active fault (12) and relevant data, and then determine the location of the upper reservoir based on the distance-to-height ratio and relevant data. Step 2: Determine the location of the main plant (1) based on the distance between the upper and lower reservoirs (10) and relevant data; Step 3: Based on the location of the main plant (1) and the lower reservoir (10) and related information, the tailwater route is determined; the tailwater route includes a tailwater tunnel (5), a tailwater forebay (13), and a tailwater open channel (8) arranged sequentially between the main plant (1) and the lower reservoir (10) and interconnected with each other. The tailwater open channel (8) passes through the active fracture (12). Step 4: Verify the adjustment and maintenance of the water conveyance system to ensure that the water pumps and turbines operate in a region with good speed regulation performance; The bottom elevation of the tailwater channel (8) is the same as the bottom elevation of the reservoir (10). The angle between the axis of the tailwater channel (8) and the direction of the active fracture (12) is not less than 60°. The excavation slope ratio of the tailwater channel (8) is 1:1.4~1.

7. A tailrace tunnel maintenance gate chamber (6) is located near the tailrace forebay (13) in the tailrace tunnel (5). A water gate (9) is arranged at the junction of the tailrace channel (8) and the lower reservoir (10). A tailgate chamber (3) is arranged downstream of the main powerhouse (1). A main transformer room (2) is set between the main powerhouse (1) and the tailgate chamber (3).

2. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, In step 1, the relevant data includes: topographic and geological conditions, environmental and water conservation sensitive factors, land acquisition and resettlement, construction conditions, and earthwork balance conditions; The lower reservoir (10) is located on the hanging wall of the active fault (12). The distance between the dam of the lower reservoir (10) and the active fault (12) satisfies the following conditions: if the dam of the lower reservoir (10) is located on the hanging wall of the active fault (12), the distance between the dam and the active fault (12) shall not be less than 400m; if the dam of the lower reservoir (10) is located on the footwall of the active fault (12), the distance between the dam and the active fault shall not be less than 600m.

3. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, In step 2, the main plant (1) is located deep in the mountain, far away from the active fault (12), while meeting the requirements for regulation and ensuring the length of the auxiliary cavern.

4. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, In step 3, the height difference between the bottom elevation of the tailwater forebay (13) and the bottom elevation of the tailwater open channel (8) is calculated using the formula for calculating the submersion depth of the inlet, and the tailwater forebay (13) and the tailwater open channel (8) are transitioned by a slope. Downstream inlet / outlet (7) is arranged in the tailwater forebay (13). The distance between the downstream inlet / outlet (7) and the movable fracture (12) is greater than 50m. The downstream inlet / outlet (7) is connected to the main plant (1) through the tailwater tunnel (5). The downstream inlet / outlet (7) is connected to the tailwater tunnel (5) and the tailwater open channel (8).

5. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, The tailwater tunnel (5) includes an upper horizontal section and a lower horizontal section. The upper horizontal section and the lower horizontal section are connected by a ramp, inclined shaft or vertical shaft. The axis of the upper horizontal section of the tailwater tunnel (5), the axis of the tailwater forebay (13) and the axis of the tailwater open channel (8) are all consistent. The upper horizontal section is connected to the downstream inlet / outlet (7).

6. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, An emergency venting pipe (11) is installed inside the lower reservoir (10).

7. The tailrace arrangement method for a pumped storage power station traversing a large active fault according to claim 1, characterized in that, In step 4, a tailwater pressure regulating chamber (4) is arranged near the main powerhouse (1) in the tailwater tunnel (5).

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