A vertical shaft and a water discharge system for a pumped storage power station

Abstract

The present invention discloses a vertical shaft and a water discharge system for a pumped-storage power station. The vertical shaft comprises a shaft body, a tunnel connected to the side walls of the shaft body, and a diverter pier vertically disposed within the tunnel. The diverter pier is connected to the shaft body, and the left and right side walls of the tunnel and diverter pier are trumpet-shaped at their connections to the shaft body. The diverter pier separates the ends of the tunnel into a first flow channel and a second flow channel, respectively connected to the shaft body. The left and right inner walls of the first and second flow channels are tangent to the inner wall of the shaft body. The vertical shaft of the present invention solves the technical problem of high construction costs of energy dissipation shafts in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy and hydropower engineering, and in particular relates to a vertical shaft and a water discharge system of a pumped storage power station. Background Art

[0002] In order to ensure the safe operation of water conservancy and hydropower projects and achieve the expected benefits when designed, the discharge structure is an important part of the water conservancy and hydropower hub project. Whether the design is reasonable and whether it can safely discharge flood water and dissipate energy directly affects the normal operation of the project hub.

[0003] Vertical shafts are a common discharge structure used in hydropower stations and pumped-storage power plants, typically located within reservoirs or mountains. During flood discharge, water typically enters the shaft body to dissipate energy through two methods: one is for water to fall vertically from the top of the shaft body into the shaft, dissipating energy in the energy dissipation well before passing through a drain tunnel to the downstream river. The other is for water to enter the shaft body horizontally through a diversion channel, rotate within the shaft body, and enter the energy dissipation well under the influence of gravity to dissipate energy. After dissipation, the water flows through the drain tunnel to the downstream river. The current method for discharging flood water into the shaft requires that the water enter the shaft at the top or upper portion of the shaft body, making the entry point inflexible. Furthermore, the water accelerates along the shaft body, dissipating energy in the energy dissipation well at the bottom of the shaft body. To ensure safe discharge, the size of the energy dissipation well must increase with increasing head and flow rate, resulting in high construction costs. Summary of the Invention

[0004] In response to the current technical problems, the present invention aims to provide a vertical shaft and a pumped storage power station discharge system, wherein the vertical shaft can solve the technical problem of high construction cost of energy dissipation wells in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A vertical shaft includes a vertical shaft body, and its structural characteristics are: it also includes a tunnel connected to the side wall of the vertical shaft body and a diverter pier vertically arranged in the tunnel, the diverter pier is connected to the vertical shaft body, and the connections between the left and right side walls of the tunnel and the diverter pier and the vertical shaft body are all trumpet-shaped structures; the diverter pier separates the end of the tunnel into a first flow channel and a second flow channel, the first flow channel and the second flow channel are respectively connected to the vertical shaft body, and the left and right inner walls of the first flow channel and the second flow channel are tangent to the inner wall of the vertical shaft body.

[0007] Both sides of the tunnel and the diversion pier are tangentially connected to the main body of the vertical shaft. Water is introduced into the main body of the vertical shaft through the tunnel, and the diversion pier diverts the water flow. The diversion pier divides the water flow into two streams, which enter the main body of the vertical shaft through the first and second flow channels respectively. Utilizing the guiding effect of the arc-shaped side walls on both sides of the first and second flow channels and the wall-attaching characteristics of the water flow, the two streams are prompted to smoothly enter the main body of the vertical shaft and then rotate along the side walls of the main body of the vertical shaft, causing a natural collision within the main body of the vertical shaft. Through the collision of the two streams and the shearing effect of the water flow within the main body of the vertical shaft, the energy of the water flow is dissipated within the main body of the vertical shaft, which can reduce the impact force of the vertical shaft flood discharge on the bottom plate of the energy dissipation shaft and the excavation depth of the energy dissipation shaft, thereby significantly reducing the construction cost of the energy dissipation shaft. In addition, the tunnel can be arranged at any elevation of the vertical shaft, making the location where the water flow enters the vertical shaft more flexible.

[0008] Preferably, the diverter pier is disposed in the middle of the tunnel, and the first and second flow channels are symmetrically disposed about the diverter pier. Due to the symmetrical arrangement of the first and second flow channels, the two water flows entering the first and second flow channels are symmetrical, and the two symmetrical water flows naturally collide within the main shaft body, thereby increasing the energy dissipation rate of the water body.

[0009] Preferably, the tunnel is a horizontal tunnel, and the center line of the horizontal tunnel along the length direction intersects perpendicularly with the axial center line of the shaft body.

[0010] Preferably, the cross-section of the tunnel is a square, and the width in the positive direction is R.

[0011] Preferably, the width of the first and second flow channels at the shaft body is greater than 0.5R. The width of the ends of the first and second flow channels is greater than 0.5R, which can ensure that the flow velocity of the water entering the shaft body does not increase, thereby reducing the impact on the shaft structure.

[0012] Preferably, the diverter pier is symmetrical about a vertical plane located along the longitudinal centerline of the tunnel, and the end of the diverter pier away from the shaft body is streamlined. Providing a streamlined head of the diverter pier can reduce the impact of water flow on the diverter pier structure, thereby ensuring the stability of the diverter pier structure.

[0013] In order to make the water flow diversion in the tunnel more uniform and stable, preferably, the cross section of the diversion pier away from the end of the shaft body along the length direction is formed by the intersection of two arc segments, and the angle between the arc segment and the center line of the diversion pier is ε, ε≤90°.

[0014] Preferably, the distance between the ends of the two arc segments is D, 0.1R≤D≤0.2R.

[0015] Preferably, the tunnels are provided in plurality, and the plurality of tunnels are arranged along the height direction of the shaft body, or the plurality of tunnels are evenly arranged along the circumference of the shaft body. The number of tunnels can be increased or decreased according to the amount of water discharge. When the plurality of tunnels are evenly arranged along the circumference of the shaft body, multiple water flows in the shaft body collide with each other, which can further increase the water flow efficiency.

[0016] Based on the same inventive concept, the present application also provides a water discharge system for a pumped-storage power station, comprising a vertical shaft as described above, wherein the main body of the vertical shaft is arranged in the reservoir area of ​​the pumped-storage power station; a vertical shaft pressure slope section is provided on the side wall of the vertical shaft main body, and the vertical shaft pressure slope section is connected to the energy dissipation pool through a water withdrawal tunnel; the outer end of the tunnel is connected to a water discharge steel pipe through a diversion section, and a valve is provided on the water discharge steel pipe, and the outer end of the water discharge steel pipe is used to be connected to the plug section of the diversion tunnel.

[0017] The diversion section is generally a gradual section. When flood discharge is required, the valve is opened and the water flows through the diversion tunnel into the discharge steel pipe, diversion section and tunnel. It is then divided into two streams by the diversion pier and enters the main body of the shaft. After energy dissipation in the main body of the shaft, the water is introduced into the stilling pool through the shaft slope section and the water withdrawal tunnel.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a vertical shaft and pumped storage power station discharge system, which connects the vertical shaft body by setting a tunnel, and uses diverter piers to divide the tunnel into two symmetrical flow channels on the plane, and the flow channels are tangent to the vertical shaft body. The water flows into the vertical shaft body from both sides of the wall through the guiding effect of the diverter piers and the flow channels, forming a natural collision in the vertical shaft body, thereby increasing the energy dissipation rate of the water body, reducing the construction cost of the downstream energy dissipation building, and reducing the impact force of the vertical shaft flood discharge on the bottom plate of the energy dissipation well, which can greatly reduce the excavation depth of the energy dissipation well. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the shaft structure of the present invention;

[0020] Figure 2 yes Figure 1 Schematic diagram of the cross-section structure;

[0021] Figure 3 Schematic diagram of the structure of the water discharge system of the pumped storage power station according to the first embodiment of the present invention;

[0022] Figure 4 yes Figure 2 Schematic diagram of the structure of the middle diversion pier head;

[0023] Figure 5 yes Figure 4 Schematic diagram of calculation parameters of the arc curve of the middle diversion pier head;

[0024] Figure 6This is a flood discharge and energy dissipation effect diagram of a tunnel provided on the main body of the vertical shaft in Example 1 of the present invention;

[0025] Figure 7 This is a flood discharge and energy dissipation effect diagram of the vertical shaft body provided with two tunnels in Example 1 of the present invention;

[0026] Figure 8 Schematic diagram of the structure of the water discharge system of the pumped storage power station according to the second embodiment of the present invention;

[0027] Figure 9 This is the flood discharge and energy dissipation flow diagram of Example 2 of the present invention;

[0028] Figure 10 It is a flood discharge and energy dissipation flow diagram of the existing technology.

[0029] In the figure

[0030] 1-Shaft body; 2-Tunnel; 201-First flow channel; 202-Second flow channel; 3-Diversion pier; 301-Arc section; 4-Diversion section; 5-Water discharge steel pipe; 6-Shaft slope pressure section; 7-Water withdrawal tunnel; 8-Stilling pool; 9-Pumped storage power station reservoir; 10-Valve; 11-Downstream river channel; 12-Spilling chute. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments may be combined unless they conflict. For ease of description, the words "upper," "lower," "left," and "right" appear below merely to indicate the directions of upper, lower, left, and right in the accompanying drawings and do not limit the structure.

[0032] Example 1:

[0033] like Figure 1 and Figure 2As shown, the discharge pipe of a pumped storage power station adopts the vertical shaft of the present invention, including a vertical shaft body 1 and a tunnel 2 connected to the vertical shaft body 1. The tunnel 2 is a horizontal tunnel, and the center line of the horizontal tunnel along the length direction perpendicularly intersects with the axial center line of the vertical shaft body 1. The cross-section of the tunnel 2 is a square, and the width in the positive direction is R. The two sides of the tunnel 2 are tangentially connected to the vertical shaft body 1 through arc ends, and the arc segments on both sides are symmetrically arranged on the plane. A diversion pier 3 is arranged in the middle of the tunnel 2, and the pier head of the diversion pier 3 is streamlined. The two sides of the diversion pier 3 are also tangentially connected to the vertical shaft body 1 through arc segments, and the arc segments on both sides are symmetrically arranged on the plane. The diversion pier 3 divides the end of the tunnel 2 into a first flow channel 201 and a second flow channel 202. The first flow channel 201 and the second flow channel 202 are respectively connected to the shaft body 1. The first flow channel 201 and the second flow channel 202 are symmetrically arranged about the diversion pier 3. The width of the first flow channel 201 and the second flow channel 202 at the shaft body 1 is greater than 0.5R. Figure 4 As shown, the cross-section of the end of the diverter pier 3 away from the shaft body 1 along the longitudinal direction is formed by the intersection of two arc segments 301. The angle between the arc segment 301 and the centerline of the diverter pier 3 is ε, ε≤90°. The distance between the ends of the two arc segments 301 is D, 0.2R≤D≤0.4R.

[0034] like Figure 3 As shown, this embodiment also provides a water discharge system for a pumped-storage power station. A vertical shaft body 1 is arranged within a reservoir area 9 of the pumped-storage power station. A vertical shaft pressure-slope section 6 is provided on the sidewall of the vertical shaft body 1. This vertical shaft pressure-slope section 6 is connected to a stilling basin 8 via a water withdrawal tunnel 7. A tunnel 2 is disposed below the vertical shaft pressure-slope section 6. The outer end of the tunnel 2 is connected to a water discharge steel pipe 5 via a diversion section 4. The inlet of the water discharge steel pipe 5 is connected to the plug section of the diversion tunnel. A valve 10 is provided at the inlet of the water discharge steel pipe 5 to control the discharge of the water discharge steel pipe 5.

[0035] The cross section of tunnel 2 is square with a width R of 2m. The water flows into tunnel 2 from the discharge steel pipe 5 and the flow state remains stable. The head of diversion pier 3 is formed by the intersection of two arc segments 301. The angle between the arc segment 301 and the horizontal line is , The angle is not greater than 45°, and the width D of the end of the diversion pier 3 is 0.35m (0.2m<0.35m<0.4m). The shape of the head of the diversion pier 3 adopts an arc curve, which can make the water flow in the flow channel more uniform and stable and reduce the head loss. Figure 5 As shown, the angle between the side wall and the center line of the diversion pier 3 is The included angles between the tangent lines of the two arc segments 301 and the center line of the diversion pier 3 are .when When the pier head is in the shape of a pointed circle (or streamlined shape), the design formula of the arc segment 301 curve parameters can be obtained through calculation:

[0036] (Formula 1)

[0037] The radius of the arc segment 301 can be calculated =0.35 / (2*(1-cos45°))=0.6m, the arc radius on both sides of tunnel 2 and diversion pier 3 is 2m, and the arc angle is 40°.

[0038] like Figure 4 and Figure 5 As shown, the derivation process of the above formula 1 is as follows:

[0039] Assume: the radius of the arc segment 301 , horizontal length of arc segment 301 , .

[0040] , ,

[0041] According to the trigonometric function relationship: , ,

[0042] ,

[0043] And because: ,so: ,

[0044] Will Substituting into the formula and simplifying it, we get:

[0045] ,

[0046] And because: ,so ,

[0047] when When , the radius of the arc curve can be obtained .

[0048] The top elevation of tunnel 2 is slightly lower than the bottom outlet elevation of the shaft pressure slope section 6, ensuring pressurized flow within tunnel 2 when the water discharge pipe 5 releases floodwater. Water flows from tunnel 2 into the shaft body 1, which is submerged, and dissipates energy at the bottom of the shaft body 1. The diverter pier 3 acts as a diverter, and at the same time, utilizing the guiding effect of the curved side walls on both sides and the wall-attaching characteristics of the water flow, the water flow is forced to split into two symmetrical streams after entering the shaft body 1. These streams rotate along the side walls of the shaft body 1 and collide within the shaft body 1. Through the collision of the two streams and the shearing effect of the water flow within the shaft body 1, the energy of the water flow is dissipated within the shaft body 1.

[0049] like Figure 6As shown, when the flood discharge is less than 40m³ / s, only one tunnel 2 can be set. Under the diversion effect of the diversion pier 3 and the guidance effect of the arc segment side walls on both sides of the first flow channel 201 and the second flow channel 202, the water flow is divided into two streams and enters the vertical shaft body 1 along the wall, forming a collision water flow. At the same time, the water flow is in the submerged water body, the shear inside the water body is fully developed, and the energy dissipation rate of the water body is greatly improved. Among them, the numbers in the figure represent the flow velocity of the water. Figure 7 As shown in the figure, when the reservoir discharge exceeds 40 m³ / s, two tunnels 2 can be arranged circumferentially around the shaft body 1. The two tunnels 2 are arranged opposite each other, so that the water flow within the shaft body 1 is divided into multiple streams and effectively collides, achieving a better energy dissipation effect. The numbers in the figure represent the flow velocity.

[0050] Conventional discharge pipe 5 is arranged at the bottom of drainage tunnel 7 and connected to energy dissipation basin 8 along the drainage tunnel 7. In Example 1 of the present invention, discharge pipe 5 is connected to shaft body 1 through tunnel 2, forming collision energy dissipation within shaft body 1. This reduces the length of discharge pipe 5 by approximately 600m. Simultaneously, the size of energy dissipation basin 8 and the excavation depth of shaft body 1 can also be significantly reduced, effectively ensuring flood discharge safety and saving construction costs.

[0051] Example 2:

[0052] like Figures 8 to 10 As shown, Example 2 of the present invention employs a vertical shaft according to the present invention at the chute outlet of a hydropower station. The shaft structure is consistent with that of Example 1. The discharge system of this pumped-storage power station includes a chute 12, which connects to the vertical shaft body 1 via a tunnel 2 when approaching the downstream river channel. Diverter piers 3 are used at the junction of tunnel 2 and the vertical shaft body 1 to divert the downstream water flow. Water flows along the wall of the vertical shaft body 1, forming a natural collision on the other side of the vertical shaft body 1. The water after the collision naturally falls to the bottom of the vertical shaft body 1 and is then discharged into the downstream river channel 11 through a water withdrawal tunnel 7.

[0053] like Figure 9 As shown, conventional hydropower stations typically use chutes 12 to discharge floodwaters. The water velocity is high. Due to the limited width of the downstream river channel, the water flows through the diversion flow into the downstream river channel 11. The water velocity continuously accelerates in the air, reaching a velocity of 20 m / s at the water surface. This can cause severe scouring of the opposite bank of the downstream river channel, posing a safety issue for flood discharge. Furthermore, due to the energy dissipation of the diversion flow, atomization problems also occur downstream. The numbers in the figure represent the water velocity.

[0054] like Figure 10As shown, the water flow in this embodiment forms collision energy dissipation in the vertical shaft body 1 through the diversion effect of the diversion pier 3. The energy is basically dissipated in the vertical shaft body 1, and the water flow can smoothly enter the downstream river channel 11. The flow velocity entering the river channel is relatively low, and the flow velocity reaching the other side of the river channel is only 2m / s~4m / s, which will not form a scouring effect on the other side of the river channel. The water mist in the energy dissipation process is concentrated in the vertical shaft body 1, which can effectively solve the downstream atomization problem and increase the safety of the downstream river channel.

[0055] The contents described in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the invention, and are not used to limit the scope of the invention. After reading the present invention, various equivalent modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A vertical shaft, comprising a vertical shaft body (1), characterized in that: It also includes a tunnel (2) connected to the side wall of the shaft body (1) and a diversion pier (3) vertically arranged in the tunnel (2), the diversion pier (3) is connected to the shaft body (1), and the connection points between the left and right side walls of the tunnel (2) and the diversion pier (3) and the shaft body (1) are all trumpet-shaped structures; The diversion pier (3) divides the end of the tunnel (2) into a first flow channel (201) and a second flow channel (202), the first flow channel (201) and the second flow channel (202) are respectively connected to the vertical shaft body (1), and the left and right inner walls of the first flow channel (201) and the second flow channel (202) are tangent to the inner wall of the vertical shaft body (1); The diverter pier (3) is arranged in the middle of the tunnel (2), and the first flow channel (201) and the second flow channel (202) are symmetrically arranged about the diverter pier (3).

2. The vertical shaft according to claim 1, characterized in that: The tunnel (2) is a horizontal tunnel, and the center line of the horizontal tunnel along the length direction intersects perpendicularly with the axial center line of the vertical shaft body (1).

3. The vertical shaft according to claim 2, characterized in that: The cross-sectional shape of the tunnel (2) is a square, and the width of the square is R.

4. The vertical shaft according to claim 3, characterized in that: The widths of the first flow channel (201) and the second flow channel (202) located at the shaft body (1) are both greater than 0.5R.

5. The vertical shaft according to claim 3, characterized in that: The diversion pier (3) is a symmetrical structure about a vertical plane where the center line of the tunnel (2) along the length direction is located, and the end of the diversion pier (3) away from the shaft main body (1) is a streamlined structure.

6. The vertical shaft according to claim 5, characterized in that: The cross section of the end of the diversion pier (3) away from the shaft body (1) along the length direction is formed by the intersection of two arc segments (301), and the angle between the arc segment (301) and the center line of the diversion pier (3) is ε, ε≤90°.

7. The vertical shaft according to claim 6, characterized in that: The distance between the ends of the two arc segments (301) is D, 0.1R≤D≤0.2R.

8. The vertical shaft according to any one of claims 1 to 7, characterized in that: There are a plurality of tunnels (2), and the plurality of tunnels (2) are arranged along the height direction of the shaft body (1), or the plurality of tunnels (2) are evenly arranged along the circumference of the shaft body (1).

9. A water discharge system for a pumped storage power station, characterized in that: The invention comprises a vertical shaft according to any one of claims 1 to 8, wherein the vertical shaft body (1) is arranged in a reservoir area (9) of a pumped storage power station; a vertical shaft pressure slope section (6) is provided on the side wall of the vertical shaft body (1), and the vertical shaft pressure slope section (6) is connected to the energy dissipation pool (8) through a water withdrawal tunnel (7); the outer end of the tunnel (2) is connected to a water discharge steel pipe (5) through a diversion section (4), and a valve (10) is provided on the water discharge steel pipe (5), and the outer end of the water discharge steel pipe (5) is used to be connected to the plug section of the diversion tunnel.

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