Tail water discharging structure of water turbine and water turbine

Abstract

The utility model discloses a water turbine tail water discharging structure and a water turbine, and belongs to the technical field of water turbine.The water turbine tail water discharging structure comprises a runner cone, a tail water pipe and a flow choking valve, the tail water pipe is arranged at the water outlet end of the runner cone, and the flow choking valve is installed at a water outlet of the runner cone; the choke valve comprises a water blocking plate, an elastic sealing plate and a connecting assembly. A drainage hole is formed in the water blocking plate, the elastic sealing plate is arranged on the side, facing the draft tube, of the water blocking plate in an attached mode and covers the drainage hole, the elastic sealing plate and the middle of the water blocking plate are connected and locked through a connecting assembly, and the elastic sealing plate can deform relative to the side, facing the draft tube, of the water blocking plate. According to the tail water discharging structure of the water turbine, one-way opening or closing of the choke valve can be automatically achieved under the action of water pressure, the proper opening and closing time is guaranteed, the operation efficiency of the water turbine is improved, meanwhile, tail water backflow can be effectively prevented, the structure is simple, and maintenance is easy.

Description

Technical Field

[0001] This application relates to the field of water turbine technology, and more specifically, to a water turbine tailrace discharge structure and a water turbine. Background Technology

[0002] In a hydroelectric power station, high-pressure water from the turbine flows through the runner into the tailrace, forming the tailrace flow. The primary function of the tailrace is to discharge this tailrace water from the turbine outlet to downstream waterways or other designated locations. Tailrace design typically considers preventing backflow, which mainly occurs during turbine shutdown, start-up, shutdown, operational abnormalities, or water level changes. Backflow can impact upstream water sources and the turbine itself, and may even affect the downstream environment and equipment safety, ultimately affecting the operation of the turbine and the entire hydroelectric power station. Therefore, preventing tailrace backflow is a crucial issue in the operation of hydroelectric power stations.

[0003] Currently, the main technology for preventing backflow of tailwater relies on the installation of devices such as sluice gates. However, these devices have problems such as untimely opening or closing, unsatisfactory backflow prevention effect, and complex maintenance. Utility Model Content

[0004] This application aims to provide a turbine tailrace discharge structure and a turbine, which solves the problems of untimely opening and closing of anti-backflow devices, unsatisfactory anti-backflow effect, and complex maintenance in the prior art.

[0005] A turbine tailrace discharge structure includes a spill cone, a tailrace pipe, and a flow-blocking valve. The tailrace pipe is arranged at the outlet end of the spill cone. The flow-blocking valve is installed at the outlet of the spill cone and is used to control the flow of water between the spill cone and the tailrace pipe. The flow-blocking valve includes a baffle plate, an elastic sealing plate, and a connecting assembly. The baffle plate is provided with a drainage hole. The elastic sealing plate is fitted onto the side of the baffle plate facing the tailrace pipe and covers the drainage hole. The elastic sealing plate is connected and locked to the middle of the baffle plate through the connecting assembly.

[0006] The flow-blocking valve includes a first state, a second state, and a third state. In the first state, the elastic sealing plate is tightly fitted to the water-blocking plate to seal the drain hole. In the second state, the elastic sealing plate deforms relative to the water-blocking plate towards the tailwater pipe under the action of a first water pressure, so that the drain hole opens in one direction and allows water to flow from the drain cone to the tailwater pipe. In the third state, the elastic sealing plate is tightly fitted to the water-blocking plate under the action of a second water pressure, so that the drain hole is sealed and water is prevented from flowing from the tailwater pipe to the drain cone.

[0007] Optionally, the flow-blocking valve further includes a flow-blocking part, which is disposed on the side of the elastic sealing plate facing the tailwater pipe, and the flow-blocking part is used to block water flow from the tailwater pipe to the drain cone.

[0008] Optionally, the flow-blocking portion has a sloping surface on the side facing the elastic sealing plate, and the distance between the sloping surface and the elastic sealing plate gradually increases along the direction from the center of the flow-blocking portion to the edge of the flow-blocking portion.

[0009] Optionally, the connecting assembly includes a first bolt and a first nut; the shank of the first bolt passes through the water-blocking plate, the elastic sealing plate and the flow-blocking part in sequence and is threadedly engaged with the first nut, the head of the first bolt abuts against the water-blocking plate and the first nut abuts against the flow-blocking part.

[0010] Optionally, the connecting assembly includes a fixing head, an elastic element, a screw, and a second nut; the fixing head, the elastic element, and the screw are connected in sequence, the screw passes through the water-blocking plate, the elastic sealing plate, and the flow-blocking part in sequence and is threadedly engaged with the second nut, the fixing head abuts against the water-blocking plate, and the second nut abuts against the flow-blocking part.

[0011] Optionally, a through hole is formed along the center of the water-blocking plate, the elastic sealing plate, and the flow-blocking part, and the elastic element and the screw are installed in the through hole; there are gaps between the elastic element and the inner wall of the through hole, and between the screw and the inner wall of the through hole.

[0012] Optionally, the elastic element includes a main body and a transition portion connected to each other. The diameter of the main body is smaller than the outer diameter of the screw. The transition portion is connected between the main body and the screw, and the diameter of the transition portion gradually increases from one end of the main body to one end of the screw.

[0013] Optionally, the number of drainage holes is set to multiple, and the multiple drainage holes are evenly distributed on the water-blocking plate.

[0014] Optionally, the material of the resilient sealing plate may include rubber.

[0015] Optionally, the outlet of the drainage cone is provided with a snap-fit ​​groove adapted to the water-blocking plate, and the water-blocking plate is detachably installed in the snap-fit ​​groove.

[0016] Beneficial effects:

[0017] The turbine tailrace discharge structure described in this application includes a spill cone, a tailrace pipe, and a flow-blocking valve. The tailrace pipe is arranged at the outlet end of the spill cone. The flow-blocking valve is installed at the outlet of the spill cone and is used to control the flow between the spill cone and the tailrace pipe. The flow-blocking valve includes a baffle plate, an elastic sealing plate, and a connecting assembly. The baffle plate is provided with a drainage hole, and the elastic sealing plate is fitted onto the side of the baffle plate facing the tailrace pipe and covers the drainage hole. The elastic sealing plate and the middle part of the baffle plate are connected and locked together by the connecting assembly. The turbine tailrace discharge structure described in this application can automatically realize the one-way opening or closing of the flow-blocking valve by utilizing the deformation or reset of the elastic sealing plate under water pressure. It can effectively deal with the reverse flow of water and avoid the problem of backflow of turbine tailrace water. Moreover, the flow-blocking valve can automatically adjust its opening and closing according to the water flow, ensuring timely response of the valve under different operating conditions. The overall structure is simple and easy to maintain.

[0018] This application also provides a water turbine, including the water turbine tailwater discharge structure as described above.

[0019] The aforementioned turbine, equipped with the tailwater discharge structure described above, can effectively prevent tailwater backflow under different operating conditions, thereby improving the turbine's operating efficiency and safety. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the turbine tailwater discharge structure proposed in one embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the flow-blocking valve in the turbine tailwater discharge structure proposed in one embodiment of this application;

[0023] Figure 3 This is a top view of the baffle plate of the flow-blocking valve in the turbine tailwater discharge structure proposed in one embodiment of this application.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Rotary wheel; 2. Drain cone; 3. Flow control valve; 31. Water baffle; 311. Drain hole; 32. Elastic sealing plate; 33. Flow control part; 331. Sloping surface; 34. Fixing head; 35. Elastic element; 351. Main body; 352. Transition part; 36. Screw; 37. Second nut; 38. Through hole; 4. Tailwater pipe; 5. Upper crown. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] In related technologies, in hydroelectric power plants, high-pressure water from the turbine enters the tailrace through the runner, forming the tailrace flow. The main function of the tailrace is to discharge this tailrace water from the turbine outlet to downstream waterways or other designated locations. Tailrace design typically considers preventing backflow, which mainly occurs during turbine shutdown, start-up, shutdown, operational abnormalities, or water level changes. Backflow can affect the upstream water source and the turbine itself, and may even impact the downstream environment and equipment safety, ultimately affecting the operation of the turbine and the entire hydroelectric power plant. Therefore, preventing tailrace backflow is a crucial issue in hydroelectric power plant operation. Currently, technologies for preventing tailrace backflow mainly rely on devices such as sluice gates, but these devices suffer from problems such as untimely opening or closing, unsatisfactory backflow prevention effects, and complex maintenance.

[0028] In view of this, this application proposes a turbine tailwater discharge structure.

[0029] See Figure 1 A turbine tailwater discharge structure includes a discharge cone 2 and a tailwater pipe 4, the tailwater pipe 4 being arranged at the outlet end of the discharge cone 2; it also includes a flow-blocking valve 3, which is installed at the outlet of the discharge cone 2 and is used to control the flow between the discharge cone 2 and the tailwater pipe 4; the flow-blocking valve 3 includes a baffle plate 31, an elastic sealing plate 32, and a connecting assembly; the baffle plate 31 is provided with a drain hole 311, and the elastic sealing plate 32 is fitted onto the side of the baffle plate 31 facing the tailwater pipe 4 and covers the drain hole 311; the elastic sealing plate 32 and the middle part of the baffle plate 31 are connected and locked together by the connecting assembly.

[0030] The flow-blocking valve 3 includes a first state, a second state, and a third state. In the first state, the elastic sealing plate 32 is tightly fitted with the water-blocking plate 31 to close the drain hole 311. In the second state, the elastic sealing plate 32 deforms relative to the water-blocking plate 31 towards the tailwater pipe 4 under the action of a first water pressure, so that the drain hole 311 opens in one direction and allows water to flow from the drain cone 2 to the tailwater pipe 4. In the third state, the elastic sealing plate 32 is tightly fitted with the water-blocking plate 31 under the action of a second water pressure, so that the drain hole 311 is closed and prevents water from flowing from the tailwater pipe 4 to the drain cone 2.

[0031] See Figure 1 The turbine tailrace discharge structure includes a spill cone 2 and a tailrace pipe 4. The tailrace pipe 4 is located at the outlet of the spill cone 2. High-pressure water from the turbine flows through the turbine runner 1 and is discharged through the tailrace pipe 4. A small portion of the water flows into the upper crown 5 of the turbine. The inner cavity of the upper crown 5 is connected to the inner cavity of the spill cone 2. When there is too much water in the upper crown 5, it needs to be discharged through the spill cone 2 to the tailrace pipe 4. In this embodiment, the turbine tailrace discharge structure also includes a flow control valve 3, which is located at the outlet of the spill cone 2 and is used to control the flow between the spill cone 2 and the tailrace pipe 4.

[0032] See Figure 2 The flow control valve 3 includes a baffle plate 31, an elastic sealing plate 32, and a connecting assembly. The baffle plate 31 is installed on the inner wall of the drain cone 2. The shape and size of the baffle plate 31 are adapted to the shape and size of the outlet of the drain cone 2. The baffle plate 31 is provided with a drain hole 311 to provide drainage space and ensure smooth water flow during normal drainage. An elastic sealing plate 32 is provided on the side of the baffle plate 31 facing the tailpipe 4. The elastic sealing plate 32 is connected and fastened to the middle area of ​​the baffle plate 31 through the connecting assembly. The elastic sealing plate 32 is fitted to the baffle plate 31 and covers the drain hole 311.

[0033] The elastic sealing plate 32 is made of a material with high wear resistance, high elasticity, and high sealing performance, such as rubber or special synthetic materials. When the elastic sealing plate 32 is attached to the water-blocking plate 31, it can achieve a seal between them, completely sealing the drain hole 311, thereby closing the flow-blocking valve 3 and preventing water from flowing through the gap between the elastic sealing plate 32 and the water-blocking plate 31. At the same time, the elastic sealing plate 32 has high elasticity and can undergo elastic deformation. When it deforms, a gap will appear between the elastic sealing plate 32 and the water-blocking plate 31, allowing the drain hole 311 to connect the drain cone 2 and the tailpipe 4, thereby opening the flow-blocking valve 3. In this embodiment, both the water-blocking plate 31 and the elastic sealing plate 32 are disc-shaped. The connecting assembly connects and fixes the two from the axis of the water-blocking plate 31 and the elastic sealing plate 32. Except for the axis-fixed area, the four edges of the elastic sealing plate 32 have the freedom of deformation.

[0034] In this embodiment, the flow control valve 3 includes at least the following three states:

[0035] When the flow-blocking valve 3 is just installed at the outlet of the discharge cone 2 and the turbine has not started working, there is no water flow in the turbine tailwater discharge structure. The flow-blocking valve 3 is not subjected to external force. At this time, the elastic sealing plate 32 and the baffle plate 31 are tightly fitted together, and the drain hole 311 is completely closed. At this time, the flow-blocking valve 3 is in the first state, that is, the naturally closed state.

[0036] When the turbine is working normally and water needs to be discharged from the spill cone 2 to the tailrace pipe 4, the water in the spill cone 2 impacts the elastic sealing plate 32 in the direction of the tailrace pipe 4 through the drain hole 311. Under the action of the drainage water pressure (i.e. the first water pressure), the elastic sealing plate 32 undergoes elastic deformation relative to the end of the baffle plate 31 facing the tailrace pipe 4, thereby automatically opening the drain hole 311, allowing the water to flow from the spill cone 2 through the drain hole 311 to the tailrace pipe 4. At this time, the flow control valve 3 is in the second state, that is, the one-way open state.

[0037] When the turbine stops or malfunctions, and the water flow at the tailrace pipe 4 reverses, the return water flows towards the discharge cone 2 and impacts the elastic sealing plate 32. Under the action of the backflow water pressure (i.e., the second water pressure), the elastic sealing plate 32 presses against the baffle plate 31 and resets. The elastic sealing plate 32 and the baffle plate 31 fit tightly together, thereby automatically sealing the drain hole 311 and preventing the water flow from the tailrace pipe 4 back to the discharge cone 2 through the drain hole 311. At this time, the flow control valve 3 is in the third state, that is, the anti-backflow closed state.

[0038] With the above settings, the deformation or reset of the elastic sealing plate 32 under water pressure can realize the one-way opening or closing of the flow-blocking valve 3, which can effectively deal with the reverse flow of water and avoid the backflow of turbine tailwater. Moreover, the opening and closing of the flow-blocking valve 3 can be automatically adjusted according to the water flow. The whole process does not require manual intervention, reducing the delay of manual operation, ensuring the timely response of the valve under different operating conditions, avoiding energy waste, and improving the operating efficiency and safety of the turbine.

[0039] Optionally, the flow-blocking valve 3 further includes a flow-blocking part 33, which is disposed on the side of the elastic sealing plate 32 facing the tailwater pipe 4. The flow-blocking part 33 is used to block water from flowing from the tailwater pipe 4 to the drain cone 2.

[0040] Specifically, a flow-blocking part 33 is also provided on the side of the elastic sealing plate 32 facing the tailwater pipe 4. The flow-blocking part 33 can provide resistance when the water flow in the tailwater pipe 4 is reversed, thereby playing a blocking role and further preventing the tailwater from flowing back. The flow-blocking part 33, the elastic sealing plate 32, and the water-blocking plate 31 are connected and fastened together by a connecting component. The arrangement is compact, occupies little space, and is easy to install and maintain.

[0041] Optionally, the flow-blocking portion 33 has a ramp surface 331 formed on the side facing the elastic sealing plate 32, and the distance between the ramp surface 331 and the elastic sealing plate 32 gradually increases along the direction from the center of the flow-blocking portion 33 to the edge of the flow-blocking portion 33.

[0042] Specifically, the flow-blocking part 33 can adopt a structure with a frustum or approximately frustum shape, see [reference]. Figure 2 In this embodiment, a ramp surface 331 is formed on the side of the flow-blocking part 33 facing the elastic sealing plate 32. The distance between the ramp surface 331 and the elastic sealing plate 32 gradually increases from the center of the flow-blocking part 33 towards its edge. By providing the ramp surface 331, on the one hand, it can provide space for the deformation of the elastic sealing plate 32, so that the elastic sealing plate 32 can deviate from the water-blocking plate 31 to the maximum extent under the action of water pressure during normal drainage, thereby allowing the drainage hole 311 to open to the maximum extent. On the other hand, the shape of the ramp surface 331 matches the flow direction of the water during drainage, which helps to reduce drainage resistance and ensures smooth water flow during normal drainage.

[0043] Optionally, the connecting assembly includes a first bolt and a first nut; the shank of the first bolt passes through the water-blocking plate 31, the elastic sealing plate 32 and the flow-blocking part 33 in sequence and is threadedly engaged with the first nut, the head of the first bolt abuts against the water-blocking plate 31, and the first nut abuts against the flow-blocking part 33.

[0044] Specifically, in one optional embodiment, the connecting assembly includes a first bolt and a first nut. Bolt holes are formed along the axis of the water-blocking plate 31, the elastic sealing plate 32, and the flow-blocking part 33 for installing the first bolt. During installation, the shank of the first bolt passes through the bolt hole from one end of the water-blocking plate 31, and then sequentially passes through the elastic sealing plate 32 and the flow-blocking part 33. The first nut is fitted onto the shank of the first bolt from one end of the flow-blocking part 33 and threadedly engages with it. After the first nut is tightened, the head of the first bolt abuts against the water-blocking plate 31, and the first nut abuts against the flow-blocking part 33, thus achieving axial connection and fixation of the water-blocking plate 31, the elastic sealing plate 32, and the flow-blocking part 33.

[0045] Optionally, the connecting assembly includes a fixing head 34, an elastic element 35, a screw 36, and a second nut 37; the fixing head 34, the elastic element 35, and the screw 36 are connected in sequence, the screw 36 passes through the water-blocking plate 31, the elastic sealing plate 32, and the flow-blocking part 33 in sequence and is threadedly engaged with the second nut 37, the fixing head 34 abuts against the water-blocking plate 31, and the second nut 37 abuts against the flow-blocking part 33.

[0046] Specifically, in another alternative embodiment, the connecting assembly includes a fixing head 34, an elastic element 35, a screw 36, and a second nut 37, see [link to previous embodiment]. Figure 2 The fixed head 34, elastic element 35, and screw 36 are connected in sequence. A through hole 38 is opened along the axis of the water-blocking plate 31, elastic sealing plate 32, and flow-blocking part 33 for installing the elastic element 35 and screw 36. During installation, the elastic element 35 and screw 36 are inserted into the through hole 38 from one end of the water-blocking plate 31. The screw 36 passes through the elastic sealing plate 32 and flow-blocking part 33 in sequence. The second nut 37 is fitted onto the screw 36 from one end of the flow-blocking part 33 and threaded into it. After the second nut 37 is tightened, the fixed head 34 presses against the water-blocking plate 31, and the second nut 37 presses against the flow-blocking part 33. Since the elastic element 35 is connected between the fixed head 34 and the screw 36, and the elastic element 35 is elastic, a certain preload can be obtained by compressing the elastic element 35 when the second nut 37 is locked with the screw 36.

[0047] Because the elastic element 35 has a certain amount of axial expansion and contraction allowance, the distance between the fixed head 34 and the second nut 37 is allowed to change slightly. During subsequent use of the flow-blocking valve 3, during normal drainage, the elastic sealing plate 32, the flow-blocking part 33, and the second nut 37 will all be subjected to the impact force of the water flow towards the tailpipe 4, thereby causing the elastic element 35 to deform slightly towards the tailpipe 4. This slightly increases the distance between the fixed head 34 and the second nut 37, allowing the elastic sealing plate 32 and the flow-blocking part 33 to move slightly axially towards the tailpipe 4 relative to the baffle plate 31. This increases the axial clearance between the elastic sealing plate 32 and the baffle plate 31, which helps to quickly open the drain hole 311, improves the valve opening response speed during drainage, and increases drainage efficiency.

[0048] Compared to rigid connections, by incorporating an elastic element 35 into the connection assembly, the elastic sealing plate 32 and the flow-blocking part 33 have a small amount of axial movement space during drainage. This allows the valve to adaptively adjust its opening according to water pressure, helping to reduce drainage resistance. Simultaneously, it reduces the water flow impact on the elastic sealing plate 32, the flow-blocking part 33, and the connection assembly, thereby reducing component wear and extending service life. In practical applications, the elastic element 35 can be made of materials with high elasticity and high wear resistance, such as rubber or special synthetic materials.

[0049] Optionally, a through hole 38 is formed along the center of the water-blocking plate 31, the elastic sealing plate 32 and the flow-blocking part 33, and the elastic element 35 and the screw 36 are installed in the through hole 38; there are gaps between the elastic element 35 and the inner wall of the through hole 38, and between the screw 36 and the inner wall of the through hole 38.

[0050] Specifically, since there are gaps between the elastic element 35 and the inner wall of the through hole 38, and between the screw 36 and the inner wall of the through hole 38, the elastic sealing plate 32 and the flow-blocking part 33 have a certain rotational margin relative to the connecting assembly, and the elastic element 35 also has a certain circumferential deformation space relative to the water-blocking plate 31. During the use of the flow-blocking valve 3, during normal drainage, the water flow may generate a rotating flow at the drain cone 2. At this time, under the action of the water flow, the elastic sealing plate 32 and the flow-blocking part 33 are allowed to rotate slightly with the water flow, and the elastic element 35 is also allowed to undergo slight twisting deformation in the through hole 38, so that the flow-blocking valve 3 can better adapt to the water flow, which helps to reduce the drainage resistance, while reducing the wear of the components caused by the impact of the water flow, and improving the service life of the flow-blocking valve 3.

[0051] Optionally, the elastic element 35 includes a main body portion 351 and a transition portion 352 connected to each other. The diameter of the main body portion 351 is smaller than the outer diameter of the screw 36. The transition portion 352 is connected between the main body portion 351 and the screw 36. The diameter of the transition portion 352 gradually increases from one end of the main body portion 351 to one end of the screw 36.

[0052] For details, see Figure 2 In this embodiment, the elastic element 35 includes a main body 351 and a transition portion 352 connected to each other. The main body 351 is shaped like a circular shaft, and its diameter is smaller than the outer diameter of the screw 36. Therefore, there is a larger gap between the main body 351 and the inner wall of the through hole 38. This gap provides sufficient space for the axial expansion and contraction deformation and circumferential twisting deformation of the main body 351. The transition portion 352 connects the main body 351 and the screw 36. The transition portion 352 is shaped like a frustum. The diameter of the end of the transition portion 352 connected to the main body 351 is consistent with the diameter of the main body 351, and the diameter of the end of the transition portion 352 connected to the screw 36 is consistent with the diameter of the screw 36. From the end of the main body 351 to the end of the screw 36, the diameter of the transition portion 352 gradually increases. By providing the transition portion 352, a transitional connection between the main body 351 and the screw 36 can be achieved, enhancing the connection reliability and improving the service life of the elastic element 35.

[0053] Optionally, see Figure 3 In this embodiment, multiple drainage holes 311 are provided, and these holes 311 are evenly distributed on the water-blocking plate 31. By providing multiple drainage holes 311, the area through which water flows during drainage is increased, drainage resistance is reduced, and drainage efficiency is improved. In practical applications, the specific number and diameter of the drainage holes 311 can be reasonably set according to drainage requirements.

[0054] Optionally, the outlet of the drainage cone 2 is provided with a snap-fit ​​groove that is compatible with the water-blocking plate 31, and the water-blocking plate 31 is detachably installed in the snap-fit ​​groove.

[0055] To further facilitate the maintenance of the flow-restricting valve 3, a detachable connection is adopted between the flow-restricting valve 3 and the drain cone 2. Specifically, in this embodiment, a snap-fit ​​groove is provided at the outlet of the drain cone 2. The shape and size of the snap-fit ​​groove are adapted to the water-blocking plate 31. During installation, the water-blocking plate 31 of the flow-restricting valve 3 is placed into the snap-fit ​​groove and snapped in, thereby fixing the flow-restricting valve 3 on the drain cone 2. Of course, based on this, bolts or other detachable fastening methods can be used to further connect and secure the water-blocking plate 31 to the drain cone 2, further improving the installation reliability of the flow-restricting valve 3. With the above settings, the installation and disassembly of the flow-restricting valve 3 are very convenient, and it is easy to inspect and maintain.

[0056] The turbine tailwater discharge structure provided in this application embodiment can effectively prevent backflow of turbine tailwater under different operating conditions, and the flow control valve can automatically adjust its opening and closing according to the water flow. It has the advantages of simple structure, high reliability and convenient maintenance, and provides a guarantee for the safe operation of hydropower generation system. It is applicable to various hydropower generation equipment and engineering projects.

[0057] This application also proposes a water turbine, including the water turbine tailwater discharge structure as described above.

[0058] The advantages of the turbine described above and the turbine tailwater discharge structure compared to the prior art are the same, and will not be repeated here.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0060] It should also be noted that, in this document, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. In the absence of further restrictions, an element defined by the phrase "includes a..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0061] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand this application, and the content of this specification should not be construed as a limitation of this application. Furthermore, for those skilled in the art, there will be different forms of changes in the specific implementation methods and application scope based on this application. It is neither necessary nor possible to exhaustively list all implementation methods here, and obvious changes or modifications derived therefrom are still within the protection scope of this application.

Claims

1. A turbine tailwater discharge structure, characterized in that, include: Drain cone, tailpipe and flow control valve; The tailwater pipe is arranged at the outlet end of the discharge cone; the flow control valve is installed at the outlet of the discharge cone to control the flow between the discharge cone and the tailwater pipe; the flow control valve includes a baffle plate, an elastic sealing plate and a connecting assembly; the baffle plate is provided with a drain hole, the elastic sealing plate is fitted to the side of the baffle plate facing the tailwater pipe and covers the drain hole, and the elastic sealing plate is connected and locked to the middle of the baffle plate through the connecting assembly; The flow-blocking valve includes a first state, a second state, and a third state. In the first state, the elastic sealing plate is tightly fitted to the water-blocking plate to seal the drain hole. In the second state, the elastic sealing plate deforms relative to the water-blocking plate towards the tailwater pipe under the action of a first water pressure, so that the drain hole opens in one direction and allows water to flow from the drain cone to the tailwater pipe. In the third state, the elastic sealing plate is tightly fitted to the water-blocking plate under the action of a second water pressure, so that the drain hole is sealed and water is prevented from flowing from the tailwater pipe to the drain cone.

2. The turbine tailrace discharge structure according to claim 1, characterized in that: The flow-blocking valve further includes a flow-blocking part, which is disposed on the side of the elastic sealing plate facing the tailwater pipe. The flow-blocking part is used to block water from flowing from the tailwater pipe to the drain cone.

3. The turbine tailrace discharge structure according to claim 2, characterized in that: The flow-blocking part has a sloping surface on the side facing the elastic sealing plate, and the distance between the sloping surface and the elastic sealing plate gradually increases along the direction from the center of the flow-blocking part to the edge of the flow-blocking part.

4. The turbine tailrace discharge structure according to claim 3, characterized in that: The connecting assembly includes a first bolt and a first nut; The shank of the first bolt passes through the water-blocking plate, the elastic sealing plate, and the flow-blocking part in sequence and is threadedly engaged with the first nut. The head of the first bolt abuts against the water-blocking plate, and the first nut abuts against the flow-blocking part.

5. The turbine tailrace discharge structure according to claim 3, characterized in that: The connecting assembly includes a fixed head, an elastic element, a screw, and a second nut; The fixing head, the elastic element, and the screw are connected in sequence. The screw passes through the water-blocking plate, the elastic sealing plate, and the flow-blocking part in sequence and is threadedly engaged with the second nut. The fixing head abuts against the water-blocking plate, and the second nut abuts against the flow-blocking part.

6. The turbine tailrace discharge structure according to claim 5, characterized in that: A through hole is formed along the center of the water-blocking plate, the elastic sealing plate, and the flow-restricting part, and the elastic element and the screw are installed in the through hole; There are gaps between the elastic element and the inner wall of the through hole, and between the screw and the inner wall of the through hole.

7. The turbine tailrace discharge structure according to claim 5 or 6, characterized in that: The elastic element includes a main body and a transition portion connected to each other. The diameter of the main body is smaller than the outer diameter of the screw. The transition portion is connected between the main body and the screw, and the diameter of the transition portion gradually increases from one end of the main body to one end of the screw.

8. The turbine tailrace discharge structure according to claim 1, characterized in that: The material of the elastic sealing plate includes rubber.

9. The turbine tailrace discharge structure according to claim 1, characterized in that: The outlet of the drainage cone is provided with a snap-fit ​​groove that is compatible with the water-blocking plate, and the water-blocking plate is detachably installed in the snap-fit ​​groove.

10. A water turbine, characterized in that, Includes the turbine tailwater discharge structure as described in any one of claims 1-9.

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