Water turbine balance pipe, flow adjusting method thereof and water turbine

Abstract

The invention relates to the technical field of water turbines, in particular to a water turbine balance pipe, a flow adjusting method thereof and a water turbine, the water turbine balance pipe comprises a balance pipe body, a valve body and an adjusting mechanism, and the balance pipe body is provided with a reducing section; the valve body is arranged in the reducing section of the balance pipe body, and a gap between the outer surface of the valve body and the inner wall of the balance pipe body forms an overflowing channel; the adjusting mechanism is connected with the valve body. The valve body moves in the variable-diameter section of the pipe body of the balance pipe, so that when fluid passes through the balance pipe, the flow changes at the position of the valve body, local resistance is generated, and then the speed and pressure distribution of the fluid are affected. By reasonably selecting the position of the valve body in the variable-diameter section of the balance pipe body, the flow and pressure of fluid can be controlled under different working conditions, a plurality of factors influencing the stability of a unit, such as leakage flow, pressure loss and axial force of the water turbine, are balanced, the leakage flow between a rotating wheel and a top cover is reduced, and proper gap cavity pressure is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic turbines, and particularly to a balance pipe of a hydraulic turbine, a flow rate adjustment method thereof, and a hydraulic turbine. Background Art

[0002] As an important hydraulic power generation equipment, the operation stability of a hydraulic turbine is directly related to the reliability and efficiency of the entire power supply system. A Francis turbine, also known as a mixed-flow turbine, belongs to a type of reaction turbine. The main components of a Francis turbine include a spiral case, a stay ring, a guide vane mechanism, a top cover, a runner, a main shaft, a guide bearing, a bottom ring, a draft tube, etc. Among them, the runner is composed of a crown, a band, and several fixed blades, and the draft tube is a water discharge component of the hydraulic turbine that leads the water flow at the runner outlet to the downstream.

[0003] In a Francis turbine system, in order to reduce the leakage loss between the runner and the stationary components, a seal ring is usually arranged in the cavity formed by the crown of the runner and the top cover. Due to the imbalance of the fluid pressure in the clearance cavity between the runner and the top cover and the fluid pressure in the runner, an axial force (water thrust) will be generated on the rotating components during the operation of the hydraulic turbine. It is necessary to connect the crown clearance cavity and the draft tube through a balance pipe to balance the pressure. The existing balance pipes are generally just conventional pipe structures, and most of them are pre-buried in concrete.

[0004] It has been found through research that in addition to the clearance size of the seal ring, the diameter of the balance pipe also has an important influence on the flow rate leakage and the axial force of the runner. However, since most of the pipe sections of the balance pipe need to be pre-buried in concrete, and its diameter is generally determined according to the specific speed and size of the runner by experience. Once the power station is built, the diameter of the pre-buried balance pipe and the clearance size of the seal ring are fixed. This fixed size combination results in excessive leakage or excessive or too small axial force at other operating conditions outside the design point, which may seriously lead to unit vibration or shaft system damage. Summary of the Invention

[0005] The present invention provides a balance pipe of a hydraulic turbine, a flow rate adjustment method thereof, and a hydraulic turbine, which are used to solve the defect that the diameter size of the balance pipe of the hydraulic turbine in the prior art is fixed, resulting in excessive leakage or excessive or too small axial force (causing unit lifting) at other operating conditions outside the design point, and to effectively control the pressure in the clearance cavity and the leakage amount, and ensure that the overall axial force of the unit is stable and controllable, reduce the air intake amount of the unit, thereby reducing the pressure pulsation and noise, reducing the operation energy consumption and water consumption of the unit, and improving the unit efficiency.

[0006] The present invention provides a water turbine balance pipe, which comprises a balance pipe body, a valve body and an adjusting mechanism. One end of the balance pipe body is connected to the upper crown clearance cavity of the water turbine, and the other end is connected to the draft tube of the water turbine. The balance pipe body is provided with a reduced-diameter section, in which the inner diameter of the balance pipe body gradually decreases or gradually increases. The valve body is arranged in the reduced-diameter section of the balance pipe body, and the gap between the outer surface of the valve body and the inner wall of the balance pipe body forms the flow passage of the water turbine balance pipe. The adjusting mechanism is connected to the valve body and is adapted to push the valve body to move in the reduced-diameter section so as to change the flow area of the flow passage of the water turbine balance pipe.

[0007] According to the water turbine balance pipe provided by the present invention, the valve body is a spindle-shaped streamline valve body, and the maximum diameter of the valve body is smaller than the minimum diameter of the reduced-diameter section of the balance pipe body.

[0008] According to the water turbine balance pipe provided by the present invention, the maximum diameter of the valve body satisfies: , where represents the maximum diameter of the valve body, represents the minimum diameter of the reduced-diameter section of the balance pipe body, represents the maximum diameter of the reduced-diameter section of the balance pipe body, represents the inclined length of the reduced-diameter section of the balance pipe body, represents the inclined angle of the reduced-diameter section of the balance pipe body.

[0009] According to the water turbine balance pipe provided by the present invention, the balance pipe body comprises a first straight pipe, a bent pipe and a second straight pipe. The first end of the first straight pipe is communicated with the draft tube of the water turbine through a sealing flange, and the first end of the first straight pipe is in a conical cylinder structure to form the reduced-diameter section. The first end of the bent pipe is connected to the second end of the first straight pipe through a sealing flange, and the adjusting mechanism passes through the bent pipe and is arranged towards the first straight pipe. The first end of the second straight pipe is connected to the second end of the bent pipe through a sealing flange, and the second end of the second straight pipe is communicated with the upper crown clearance cavity of the water turbine through a sealing flange.

[0010] According to the water turbine balance pipe provided by the present invention, the adjusting mechanism comprises a connecting seat, a connecting rod and a driving device. The connecting seat is fixed on the bent pipe, and a connecting channel coaxial with the axis of the first straight pipe is formed in the connecting seat, and the connecting channel is communicated with the bent pipe. The connecting rod passes through the connecting channel of the connecting seat and the bent pipe, and the first end of the connecting rod is connected to the valve body. The driving device is connected to the second end of the connecting rod and is adapted to drive the connecting rod to move along the axis of the first straight pipe so as to adjust the position of the valve body in the first straight pipe.

[0011] A water turbine balance pipe provided according to the present invention, the connection seat includes a connection sleeve, a connection end cover, a seal and a sealing filler. The first end of the connection sleeve is welded to the elbow pipe, the second end of the connection sleeve is provided with a stepped hole, and the connection sleeve is coaxially arranged with the first straight pipe; the connection end cover is detachably connected to the stepped hole at the second end of the connection sleeve, and a through hole is provided in the center of the connection end cover, which is adapted to sequentially penetrate the connecting rod through the through hole in the center of the connection end cover, the connection sleeve and the elbow pipe; the seal is arranged in the gap between the connecting rod and the connection sleeve; the sealing filler is filled between the connection end cover and the stepped hole at the second end of the connection sleeve.

[0012] The present invention also provides a method for adjusting the flow rate of a water turbine balance pipe, which is applicable to adjusting the flow area of the water turbine balance pipe described in any one of the above. The method for adjusting the flow rate of the water turbine balance pipe includes: Perform a numerical simulation of the fluid flow of the water turbine on the main flow path, upper crown cavity, lower ring cavity, seal ring and balance pipe of the water turbine, and simulate different operating points of the water turbine.

[0013] Under the simulation of the first operating point of the water turbine, change the position of the valve body in the variable diameter section of the balance pipe body through the adjusting mechanism to change the flow area of the balance pipe body, and obtain the axial force of the runner of the water turbine corresponding to different flow areas of the balance pipe body and the leakage amount between the runner and the stationary components, form a test set, and based on the formed test set, obtain the position of the valve body corresponding to the optimal axial force of the runner of the water turbine at the first operating point and the leakage amount between the runner and the stationary components through an optimization algorithm.

[0014] Change the simulation operating point of the water turbine, and again change the position of the valve body in the variable diameter section of the balance pipe body through the adjusting mechanism, and respectively obtain the position of the valve body corresponding to the optimal axial force of the runner of the water turbine at other operating points and the leakage amount between the runner and the stationary components.

[0015] Integrate the positions of the valve body corresponding to the axial force of the runner at all operating points and the leakage amount between the runner and the stationary components in the optimal case to form a data set.

[0016] During the actual operation of the water turbine, adjust the position of the valve body in the variable diameter section of the balance pipe body based on the data set to change the flow area of the balance pipe body, so that the axial force of the runner of the water turbine and the leakage amount between the runner and the stationary components are kept in an optimal state.

[0017] A method for regulating the flow rate of a balance pipe of a water turbine provided by the present invention, during the actual operation of the water turbine, based on the data set, adjust the position of the valve body within the variable diameter section of the balance pipe body, and adopt an automatic control process, the automatic control process includes: storing the data set in the form of a data table in the control system of the water turbine power station; the control system of the water turbine power station automatically controls the adjustment mechanism to adjust the position of the valve body based on the data set to match the actual operating conditions of the water turbine.

[0018] A method for regulating the flow rate of a balance pipe of a water turbine provided by the present invention, during the actual operation of the water turbine, based on the data set, adjust the position of the valve body within the variable diameter section of the balance pipe body, and adopt a manual control process, the manual control process includes: classifying and dividing the data set according to the operating condition range of the water turbine, forming a plurality of grading indication keys on the adjustment mechanism, and different grading indication keys respectively correspond to different operating conditions of the water turbine; based on the actual operating condition of the water turbine, manually adjust the corresponding grading indication key on the adjustment mechanism to match the actual operating condition of the water turbine.

[0019] The present invention also provides a water turbine, including the water turbine balance pipe described in any one of the above, or capable of performing the water turbine balance pipe flow rate adjustment method described in any one of the above.

[0020] The water turbine balance pipe provided by the present invention, by arranging a variable diameter section in the balance pipe body and movably arranging a valve body within the variable diameter section, based on the position change of the valve body within the variable diameter section of the balance pipe body, when the fluid passes through the balance pipe, the flow rate will change at the valve body, generating a local resistance, thereby affecting the velocity and pressure distribution of the fluid. By reasonably selecting the position of the valve body within the variable diameter section of the balance pipe body, the flow rate and pressure of the fluid can be controlled under different operating conditions, balancing multiple factors affecting the stability of the unit such as the leakage flow rate, pressure loss, and axial force of the water turbine, reducing the leakage flow rate between the runner and the top cover, maintaining an appropriate gap chamber pressure, and in addition, reducing the demand for top cover air supplement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of the water turbine balance pipe provided by the present invention.

[0023] Figure 2 is a schematic structural diagram of the cooperation between the valve body and the variable diameter section of the balance pipe body provided by the present invention.

[0024] Figure 3 This is a schematic structural diagram of the valve body provided by the present invention.

[0025] Reference numerals: 1. Balancing pipe body; 11. First straight pipe; 12. Elbow pipe; 13. Second straight pipe; 2. Valve body; 3. Adjusting mechanism; 31. Connecting seat; 311. Connecting sleeve; 312. Connecting end cover; 313. Sealing member; 314. Sealing packing; 32. Connecting rod; 33. Driving device. Detailed implementation manners

[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0029] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely means that the horizontal height of the first feature is less than that of the second feature.

[0030] In the description of this specification, the description referring to terms such as "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0031] The following is combined with Figures 1 to 3 to describe the water turbine balance pipe, its flow rate adjustment method, and the water turbine of the present invention.

[0032] An embodiment of the present invention provides a water turbine balance pipe. Referring to Figure 1 as shown, the water turbine balance pipe includes a balance pipe body 1, a valve body 2, and an adjustment mechanism 3. One end of the balance pipe body 1 is connected to the upper crown clearance cavity of the water turbine, and the other end is connected to the draft tube of the water turbine. The balance pipe body 1 is provided with a reduced-diameter section, and in the reduced-diameter section, the inner diameter of the balance pipe body 1 gradually decreases or gradually increases; the valve body 2 is arranged in the reduced-diameter section of the balance pipe body 1, and the gap between the outer surface of the valve body 2 and the inner wall of the balance pipe body 1 forms the flow passage of the water turbine balance pipe; the adjustment mechanism 3 is connected to the valve body 2 and is adapted to push the valve body 2 to move in the reduced-diameter section to change the flow area of the flow passage of the water turbine balance pipe.

[0033] It can be understood that for the water turbine balance pipe provided in this embodiment, by providing a reduced-diameter section in the balance pipe body 1 and movably arranging a valve body 2 in the reduced-diameter section, based on the position change of the valve body 2 in the reduced-diameter section of the balance pipe body 1, when the fluid passes through the balance pipe, a flow rate change will occur at the valve body 2, generating a local resistance, thereby affecting the velocity and pressure distribution of the fluid. By reasonably selecting the position of the valve body 2 in the reduced-diameter section of the balance pipe body 1, the flow rate and pressure of the fluid can be controlled under different working conditions, balancing multiple factors affecting the stability of the unit such as the leakage flow rate, pressure loss, and axial force of the water turbine, reducing the leakage flow rate between the runner and the top cover, maintaining an appropriate clearance chamber pressure, and in addition, reducing the demand for top cover air supply.

[0034] In some embodiments of the water turbine balance pipe of the present invention, the valve body 2 is a spindle-shaped streamlined valve body, and the maximum diameter of the valve body 2 is smaller than the minimum diameter of the reduced-diameter section of the balance pipe body 1. The maximum diameter of the valve body 2 satisfies: , where represents the maximum diameter of the valve body, represents the minimum diameter of the reduced-diameter section of the balance pipe body, represents the maximum diameter of the reduced-diameter section of the balance pipe body, represents the inclined length of the reduced-diameter section of the balance pipe body, represents the inclined angle of the reduced-diameter section of the balance pipe body.

[0035] It can be understood that the valve body 2 in this embodiment is a spindle-shaped streamlined valve body. The spindle-shaped streamlined valve body moves along the axial direction of the balance pipe body 1 in the reduced-diameter section of the balance pipe body 1. The flow passage area formed between the outer surface of the spindle-shaped streamlined valve body and the inner wall of the balance pipe body 1 changes as the valve body 2 moves. Subsequently, when the fluid passes through the balance pipe, a flow rate change will occur at the valve body 2, generating a local resistance and affecting the velocity and pressure distribution of the fluid.

[0036] The diameter distribution of the spindle-shaped streamlined valve body conforms to a specific axial distribution law, and can adjust the flow passage area of the balance pipe according to the position of the valve body 2, thereby adjusting the flow rate through the balance pipe and the pressure distribution in the cavity. Refer to Figure 2 shown, the maximum diameter of the spindle-shaped streamlined valve body can be defined by the following formula: Based on the above two groups of formulas, it can be obtained that the maximum diameter of the valve body 2 satisfies: , where represents the maximum diameter of the valve body, represents the minimum diameter of the reduced-diameter section of the balance pipe body, represents the maximum diameter of the reduced-diameter section of the balance pipe body, represents the inclined length of the reduced-diameter section of the balance pipe body, Indicates the inclination angle of the reduced-diameter section of the balance pipe body.

[0037] Further, referring to Figure 3 as shown, the spindle-shaped streamlined valve body can be equally divided into 10 segments along the axial direction, and the length of each segment is: , where is the overall length of the spindle, is the length of each segment of the spindle-shaped streamlined valve body, and the length of each segment is equal. Take the inclination angle of the reduced-diameter section of the balance pipe body as 10°, and the diameter of the th segment of the spindle-shaped streamlined valve body changes with the axial position and can be calculated by the following formula: The axial diameter size of the spindle-shaped streamlined valve body is obtained as shown in the following table:

[0038] Based on the above table, it can be seen that in this embodiment, the spindle-shaped streamlined valve body is equally divided into 10 segments along the axial direction, that is, 9 working positions of the spindle-shaped streamlined valve body are formed, corresponding to in turn. Each working position corresponds to a valve body diameter. By adjusting the axial position of the spindle-shaped streamlined valve body, the position change of the valve body 2 in the reduced-diameter section of the balance pipe body 1 is realized, and then the flow area of the flow passage of the water turbine balance pipe is changed.

[0039] In some embodiments of the water turbine balance pipe of the present invention, referring to Figure 1 again as shown, the balance pipe body 1 includes a first straight pipe 11, a bent pipe 12 and a second straight pipe 13. The first end of the first straight pipe 11 is connected to the draft tube of the water turbine through a sealing flange. The first end of the first straight pipe 11 is a conical cylinder structure to form a reduced-diameter section. The first end of the bent pipe 12 is connected to the second end of the first straight pipe 11 through a sealing flange. The adjusting mechanism 3 is arranged through the bent pipe 12 and towards the first straight pipe 11. The first end of the second straight pipe 13 is connected to the second end of the bent pipe 12 through a sealing flange. The second end of the second straight pipe 13 is connected to the upper crown clearance cavity of the water turbine through a sealing flange.

[0040] It is understandable that the first end of the first straight pipe 11 in this embodiment is designed as a conical cylinder structure to form a reduced-diameter section. This design helps to generate a certain pressure change when the fluid enters the balance pipe, thereby affecting the flow control. The adjusting mechanism 3 is disposed through the elbow pipe 12 and is oriented towards the first straight pipe 11. This means that the adjusting mechanism 3 can directly act on the valve body 2 located in the first straight pipe, thereby adjusting the area of the flow passage. The second straight pipe 13 ensures smooth fluid flow from the draft tube to the cavity between the upper crown clearances, and the fluid flow characteristics during this process can be optimized by changing the position of the valve body 2 through the adjusting mechanism 3. The combined use of the above components in this embodiment allows for precise control of the water flow velocity and pressure distribution flowing through the balance pipe through the adjusting mechanism 3, thereby effectively managing the leakage volume and axial force during the operation of the water turbine, not only improving the flexibility and adaptability of the system, but also enhancing the overall performance and reliability of the equipment. In addition, the use of the sealing flange ensures the sealing performance of each connection point and reduces the potential leakage risk.

[0041] The balance pipe body 1 and the sealing flange are made of high-carbon steel materials, and the sealing flange is a polytetrafluoroethylene sealing ring, ensuring the durability and sealing performance of the system. Under some special working conditions, the selection of the materials for the balance pipe body 1 and the sealing flange is crucial for the long-term operation stability of the system. The connection can be made by bolt connection, and the bolts are high-strength stainless steel hexagon bolts to enhance the structural strength and reliability, thereby effectively extending the service life of the water turbine balance pipe.

[0042] In some embodiments of the water turbine balance pipe of the present invention, the adjusting mechanism 3 includes a connection seat 31, a connecting rod 32, and a driving device 33. The connection seat 31 is fixed on the elbow pipe 12. A connection channel coaxial with the axis of the first straight pipe 11 is formed in the connection seat 31, and the connection channel communicates with the elbow pipe 12; the connecting rod 32 is disposed through the connection channel of the connection seat 31 and the elbow pipe 12, and the first end of the connecting rod 32 is connected to the valve body 2; the driving device 33 is connected to the second end of the connecting rod 32 and is adapted to drive the connecting rod 32 to move along the axis of the first straight pipe 11 to adjust the position of the valve body 2 in the first straight pipe 11.

[0043] It is understandable that a connection channel coaxial with the axis of the first straight pipe 11 is formed inside the connection seat 31. This connection channel not only communicates with the elbow pipe 12, but also provides the necessary installation and operation space for the subsequent components. The connecting rod 32 is disposed through the connection channel of the connection seat 31 and the elbow pipe 12, and the first end of the connecting rod 32 is directly connected to the valve body 2. This enables the position of the valve body 2 to be indirectly controlled by moving the connecting rod 32. The driving device 33 can push the connecting rod 32 to reciprocate along the axis direction of the first straight pipe 11. This movement can change the specific position of the valve body 2 in the first straight pipe 11, thereby achieving precise adjustment of the flow channel area.

[0044] When it is necessary to adjust the flow rate in the balance pipe of the water turbine, the driving device 33 is started. It will push or pull the connecting rod 32, and the movement of the connecting rod 32 will cause the spindle-shaped streamline valve body 2 connected to it to move axially in the first straight pipe 11. Since the first end of the first straight pipe 11 is designed as a conical cylinder structure (variable diameter section), the valve body 2 will affect the flow-through area at different positions, thereby controlling the water flow velocity and pressure distribution through the balance pipe. In this way, the leakage volume and axial force during the operation of the water turbine can be effectively managed, and the equipment performance can be optimized.

[0045] It should be understood that the driving device 33 in this embodiment can be a driving motor, and the connecting rod 32 can be in the form of telescopic adjustment (the driving device 33 is a linear motor) or spiral connection (the driving device 33 is a rotary motor) to realize the electric axial movement adjustment of the connecting rod 32; the driving device 33 can also be a push-pull device suitable for realizing the axial movement of the connecting rod 32 by manual pushing and pulling.

[0046] Furthermore, the connecting seat 31 includes a connecting sleeve 311, a connecting end cover 312, a seal 313 and a sealing filler 314. The first end of the connecting sleeve 311 is welded to the elbow 12, the second end of the connecting sleeve 311 is provided with a stepped hole, and the connecting sleeve 311 is coaxially arranged with the first straight pipe 11; the connecting end cover 312 is detachably connected to the stepped hole at the second end of the connecting sleeve 311, and a through hole is provided in the center of the connecting end cover 312, which is suitable for passing the connecting rod 32 through the through hole in the center of the connecting end cover 312, the connecting sleeve 311 and the elbow 12 in sequence; the seal 313 is arranged in the gap between the connecting rod 32 and the connecting sleeve 311; the sealing filler 314 is filled between the connecting end cover 312 and the stepped hole at the second end of the connecting sleeve 311.

[0047] The second end of the connecting sleeve 311 is provided with a stepped hole for installing the connecting end cover 312, and the connecting sleeve 311 is coaxially arranged with the first straight pipe 11, ensuring the smoothness and consistency of the fluid passage. A through hole is provided in the center of the connecting end cover 312, allowing the connecting rod 32 to pass through this hole, the connecting sleeve 311, and the elbow 12 in sequence, thereby realizing the drive control of the valve body 2. The seal 313 is arranged in the gap between the connecting rod 32 and the connecting sleeve 311 to prevent fluid leakage and ensure the sealing performance of the system. It can usually be an O-ring or other types of sealing gaskets, and appropriate materials and shapes are selected according to specific applications. The sealing packing 314 is filled between the connecting end cover 312 and the stepped hole at the second end of the connecting sleeve 311 to further enhance the sealing effect. The sealing packing 314 can not only prevent fluid leakage but also compensate for the small displacements caused by temperature changes or mechanical vibrations, maintaining long-term sealing performance. In this embodiment, by using the seal 313 and the sealing packing 314, the device can still maintain good sealing performance under high-pressure and high-temperature conditions, avoiding fluid leakage. The detachable design of the connecting end cover 312 makes it more convenient to repair and replace internal components, reducing the downtime. The connecting rod 32 passes through the through hole and the connecting sleeve 311 to ensure the accuracy of its movement trajectory, thereby realizing the precise control of the position of the valve body 2 and further optimizing the flow regulation. This detailed design of the connecting seat 31 not only enhances the sealing performance and reliability of the system but also improves the operation accuracy and maintainability. The close cooperation between the components ensures the stable operation of the entire regulating mechanism 3, contributing to the improvement of the overall performance and efficiency of the water turbine. In particular, the application of the seal 313 and the sealing packing 314 is crucial for ensuring the long-term stable operation of the system.

[0048] On the other hand, the present invention also provides a method for regulating the flow rate of a turbine balance pipe, which is suitable for regulating the flow area of ​​a turbine balance pipe in any of the above embodiments. In some specific embodiments, the method for regulating the flow rate of a turbine balance pipe includes: numerically simulating the flow of turbine fluid in the main flow channel, the upper crown cavity, the lower ring cavity, the leak-proof ring and the balance pipe of the turbine, and simulating different operating points of the turbine. Under the simulation of the first operating point of the turbine, the position of the valve body 2 in the variable diameter section of the balance pipe body 1 is changed by the adjustment mechanism 3 to change the flow area of ​​the balance pipe body 1, and the corresponding axial force of the turbine runner and the leakage between the runner and the stationary parts of the balance pipe body 1 under different flow areas are obtained to form a test set. Based on the formed test set, the position of the valve body 2 corresponding to the axial force of the runner and the leakage between the runner and the stationary parts at the first operating point of the turbine is obtained by an optimization algorithm. The simulated operating point of the turbine is changed, and the position of the valve body 2 in the variable diameter section of the balancing pipe body 1 is changed again by the regulating mechanism 3, and the positions of the valve body 2 corresponding to the runner axial force and the leakage between the runner and the stationary parts at other operating points of the turbine are obtained respectively. The positions of the valve body 2 corresponding to the runner axial force and the leakage between the runner and the stationary parts at all operating points under the optimal conditions are integrated to form a data set. During the actual operation of the turbine, the position of the valve body 2 in the variable diameter section of the balancing pipe body 1 is adjusted based on the data set to change the flow area of ​​the balancing pipe body 1, so that the runner axial force of the turbine and the leakage between the runner and the stationary parts are kept in the optimal state.

[0049] It can be understood that the turbine balance pipe flow rate regulation method of this embodiment is to record the axial position ( ), flow area change and runner axial force ( ) and leakage ( ) and construct a data set based on the simulation results and , to determine each operating condition (opening , optimal valve position under power N) , corresponding to the working positions of valve body 2 are Through this method, the position of the valve body 2 is dynamically adjusted to optimize the flow field distribution in the balance tube, thereby achieving a reasonable balance between the axial force and the leakage, effectively reducing the pressure pulsation and noise, and improving the stability and efficiency of the unit operation.

[0050] Furthermore, during the actual operation of the water turbine, adjusting the position of the valve body 2 within the variable-diameter section of the balance pipe body 1 based on the data set can be achieved through automatic control or manual control. By manually or automatically adjusting the position of the spindle-shaped streamlined valve body within the water turbine balance pipe, the impedance of the water turbine balance pipe can be adjusted.

[0051] In some specific examples, adjusting the position of the valve body 2 within the variable-diameter section of the balance pipe body 1 is carried out through an automatic control process. The automatic control process includes: storing the data set in the form of a data table in the water turbine power station control system; the water turbine power station control system automatically controls the adjusting mechanism 3 to adjust the position of the valve body 2 based on the data set to match the actual operating conditions of the water turbine.

[0052] It can be understood that the automatic control process includes data storage and an automatic adjustment mechanism. The data set obtained through numerical simulation and optimization algorithms is stored in the form of a data table in the water turbine power station control system. These data include the optimal position of the valve body 2 and its corresponding runner axial force and leakage volume under different operating condition points. The water turbine power station control system is integrated with the adjusting mechanism 3 and can monitor the actual operating conditions of the water turbine in real time. Based on the current operating conditions, the control system automatically calls the corresponding data and automatically adjusts the position of the valve body 2 through the adjusting mechanism 3 to ensure that its flow area is always in the best state. The water turbine power station control system can perform dynamic adjustment according to the real-time monitored changes in operating conditions to ensure that the water turbine can maintain optimal performance under various operating conditions.

[0053] Suppose the water turbine is gradually transitioning from a low load to a high load operating condition: The water turbine power station control system monitors the increase in load in real time and identifies that the current operating condition belongs to the high load range. The system automatically calls the data of the optimal position of the valve body 2 corresponding to the high load operating condition in the data set. The position of the valve body 2 is automatically adjusted through the adjusting mechanism 3 to make the flow area of the balance pipe reach the best state, thereby optimizing the runner axial force and leakage volume.

[0054] In some other specific examples, adjusting the position of the valve body 2 within the variable-diameter section of the balance pipe body 1 is carried out through a manual control process. The manual control process includes: classifying and dividing the data set according to the operating condition range of the water turbine, forming multiple adjustment level indication keys on the adjusting mechanism 3, and different adjustment level indication keys respectively corresponding to different operating conditions of the water turbine; manually adjusting the corresponding adjustment level indication key on the adjusting mechanism 3 based on the actual operating conditions of the water turbine to match the actual operating conditions of the water turbine.

[0055] It can be understood that the manual control process requires prior data level division on the regulating mechanism 3, and the data set is classified according to the operating range of the water turbine. For example, the operating conditions can be divided into different intervals such as low load, medium load, and high load. Multiple grading indication keys are formed on the regulating mechanism 3, and each grading indication key corresponds to a specific operating range. These indication keys are used to quickly select the appropriate position of the valve body 2. Based on the current actual operating condition of the water turbine, the corresponding grading indication key is manually adjusted on the regulating mechanism 3. For example, if the water turbine is currently in a high load condition, the operator can select the grading indication key corresponding to high load. Through the preset grading indication key, the operator can quickly find and adjust to the optimal position of the valve body 2, reducing human error and adjustment time.

[0056] Suppose the water turbine needs to switch from normal operation to emergency load mode: The operator observes that the water turbine is about to enter the emergency load mode and determines that the current operating condition belongs to the emergency load interval. The operator finds and presses the grading indication key corresponding to the emergency load on the regulating mechanism 3. The regulating mechanism 3 adjusts the position of the valve body 2 according to the preset data to ensure good performance even under emergency load conditions.

[0057] Whether using automatic control or manual control, the water turbine balance pipe flow regulation method provided by the present invention can effectively optimize the operating performance of the water turbine. The automatic control method is suitable for scenarios that require high precision and fast response, while manual control provides more flexibility and simplicity, suitable for some specific operation requirements. The combination of the two control methods can further improve the reliability and adaptability of the system, ensuring that the water turbine can maintain the best performance under various operating conditions.

[0058] The present invention also provides a water turbine, including the water turbine balance pipe in any one of the above embodiments, or capable of implementing the water turbine balance pipe flow regulation method in any one of the above embodiments. It can be understood that the water turbine provided by the present invention, due to including the above water turbine balance pipe, enables the water turbine of the present invention to have the flow regulation function of the water turbine balance pipe. The water turbine balance pipe can not only be used on the designed Francis conventional units and pumped storage units, especially for the units of the power stations under construction and already built, its crown design is simple, and it can be conveniently maintained and replaced through quick disassembly and installation, reducing the shutdown time of the system. At the same time, the dynamic regulation function of the balance pipe can effectively cope with the pressure changes under different operating conditions, optimize the operating performance of the water turbine, further improve the efficiency of the system, reduce the operating cost, and ensure the long-term stable operation of the water turbine.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A turbine balance pipe, characterized in that: include: A balance pipe body (1) has one end connected to the upper crown gap cavity of the turbine and the other end connected to the tailwater pipe of the turbine, wherein the balance pipe body (1) is provided with a diameter-changing section, and the inner diameter of the balance pipe body (1) gradually decreases or gradually increases in the diameter-changing section; A valve body (2) is arranged in the diameter-changing section of the balancing pipe body (1), and a gap between an outer surface of the valve body (2) and an inner wall of the balancing pipe body (1) constitutes a flow passage of the turbine balancing pipe; The regulating mechanism (3) is connected to the valve body (2) and is suitable for pushing the valve body (2) to move in the diameter-changing section to change the flow area of ​​the flow passage of the turbine balance pipe.

2. The turbine balance pipe according to claim 1, characterized in that: The valve body (2) is a spindle-shaped streamlined valve body, and the maximum diameter of the valve body (2) is smaller than the minimum diameter of the diameter-changing section of the balancing pipe body (1).

3. The turbine balance pipe according to claim 2, characterized in that: The maximum diameter of the valve body (2) satisfies: , where Indicates the maximum diameter of the valve body. Indicates the minimum diameter of the reducing section of the balancing pipe body. Indicates the maximum diameter of the reducing section of the balancing pipe body. Indicates the inclined length of the reducing section of the balancing pipe body. Indicates the inclination angle of the reducing section of the balancing pipe body.

4. The turbine balance pipe according to any one of claims 1 to 3, characterized in that: The balancing pipe body (1) comprises: a first straight pipe (11), wherein a first end of the first straight pipe (11) is connected to a draft tube of a water turbine via a sealing flange, and the first end of the first straight pipe (11) is a conical cylinder structure to form the variable diameter section; a curved pipe (12), wherein a first end of the curved pipe (12) is connected to a second end of the first straight pipe (11) via a sealing flange, and the adjusting mechanism (3) is disposed through the curved pipe (12) and is arranged in a direction toward the first straight pipe (11); A second straight pipe (13), wherein a first end of the second straight pipe (13) is connected to a second end of the curved pipe (12) via a sealing flange, and a second end of the second straight pipe (13) is communicated with an upper crown gap cavity of the turbine via the sealing flange.

5. The turbine balance pipe according to claim 4, characterized in that: The regulating mechanism (3) comprises: a connecting seat (31) fixed on the curved pipe (12), wherein a connecting channel coaxial with the axis of the first straight pipe (11) is formed in the connecting seat (31), and the connecting channel is in communication with the curved pipe (12); A connecting rod (32) passing through the connecting passage of the connecting seat (31) and the bent pipe (12), wherein a first end of the connecting rod (32) is connected to the valve body (2); A driving device (33) is connected to the second end of the connecting rod (32) and is suitable for driving the connecting rod (32) to move along the axis of the first straight pipe (11) to adjust the position of the valve body (2) in the first straight pipe (11).

6. The turbine balance pipe according to claim 5, characterized in that: The connecting seat (31) comprises: a connecting sleeve (311), wherein a first end of the connecting sleeve (311) is welded to the bent pipe (12), a second end of the connecting sleeve (311) is provided with a stepped hole, and the connecting sleeve (311) is coaxially arranged with the first straight pipe (11); A connecting end cover (312) is detachably connected to the stepped hole at the second end of the connecting sleeve (311); a through hole is provided at the center of the connecting end cover (312), suitable for the connecting rod (32) to sequentially pass through the through hole at the center of the connecting end cover (312), the connecting sleeve (311) and the bent pipe (12); A sealing member (313) is arranged in a gap between the connecting rod (32) and the connecting sleeve (311); A sealing filler (314) is filled between the connection end cover (312) and the step hole at the second end of the connection sleeve (311).

7. A method for regulating flow of a water turbine balance pipe, characterized in that: The method is suitable for adjusting the flow area of ​​the turbine balance pipe according to any one of claims 1 to 6, and the flow rate adjustment method of the turbine balance pipe comprises: Numerical simulation of turbine fluid flow is performed on the flow in the main flow channel, upper crown cavity, lower ring cavity, stop ring and balance pipe of the turbine to simulate different operating points of the turbine; Under the simulation condition of the first operating point of the water turbine, the position of the valve body (2) in the variable diameter section of the balancing pipe body (1) is changed by means of the regulating mechanism (3) to change the flow area of ​​the balancing pipe body (1), and the corresponding runner axial force of the water turbine and the leakage between the runner and the stationary parts under different flow areas of the balancing pipe body (1) are obtained to form a test set, and based on the formed test set, the position of the valve body (2) corresponding to the runner axial force and the leakage between the runner and the stationary parts under the optimal condition at the first operating point of the water turbine is obtained by means of an optimization algorithm; Changing the simulated operating point of the turbine, again changing the position of the valve body (2) in the variable diameter section of the balancing pipe body (1) through the regulating mechanism (3), and obtaining the position of the valve body (2) corresponding to the runner axial force and the leakage between the runner and the stationary parts under the optimal condition at other operating points of the turbine; Integrate the positions of the valve body (2) corresponding to the axial force of the runner and the leakage between the runner and the stationary parts at all operating points under the optimal condition to form a data set; During the actual operation of the turbine, the position of the valve body (2) in the variable diameter section of the balancing pipe body (1) is adjusted based on the data set to change the flow area of ​​the balancing pipe body (1), so that the axial force of the turbine runner and the leakage between the runner and the stationary parts are kept in an optimal state.

8. The method for regulating flow rate of a hydraulic turbine balance pipe according to claim 7, characterized in that: During the actual operation of the turbine, the position of the valve body (2) in the variable diameter section of the balancing pipe body (1) is adjusted based on the data set, using an automatic control process, the automatic control process comprising: storing the data set in a control system of a hydro-turbine power station in the form of a data table; The control system of the hydro-turbine power station automatically controls the regulating mechanism (3) to adjust the position of the valve body (2) based on the data set to match the actual operating conditions of the hydro-turbine.

9. The method for regulating flow of a hydraulic turbine balance pipe according to claim 7, characterized in that: During the actual operation of the turbine, the position of the valve body (2) in the variable diameter section of the balancing pipe body (1) is adjusted based on the data set, using a manual control process, the manual control process comprising: The data set is divided into grades according to the turbine operating condition range, and a plurality of grade adjustment indication keys are formed on the adjustment mechanism (3), wherein different grade adjustment indication keys correspond to different turbine operating conditions; Based on the actual operating conditions of the water turbine, the corresponding level adjustment indicator key is manually adjusted on the adjustment mechanism (3) to match the actual operating conditions of the water turbine.

10. A water turbine, characterized in that: It comprises a turbine balance pipe as described in any one of claims 1 to 6, or can implement a turbine balance pipe flow regulation method as described in any one of claims 7 to 9.

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