Telescopic adjustable runner runner cone of water turbine and adjusting method

Abstract

The telescopic adjustable water turbine runner runner runner cone comprises an upper crown, a lower ring and blades, a runner cone body is integrally formed at the bottom of the upper crown, the upper end of a sleeve is fixedly connected with the lower end of the runner cone body and communicates with a cavity, an air supplementing cavity is formed in an air supplementing piece, and the upper end of the air supplementing piece is open; a plurality of water leakage holes communicated with the air supply cavity are formed in the lower end of the air supply part, an air guide cavity is further formed in the air supply part and located on the peripheral side of the air supply cavity, a plurality of air leakage holes for communicating the air supply cavity with the air guide cavity are formed in the peripheral side close to the lower end of the air supply part, the upper end of the air supply part is slidably connected with the sleeve, and the air supply cavity is communicated with the sleeve through the opening; and the lower end of the gas conveying pipe is sequentially arranged in the runner cone and the sleeve in a penetrating mode and communicates with the gas guide cavity. The problems that when water flow passes through the runner cone, the runner cone possibly generates vortexes at some parts, the pressure in a vortex area is low, cavitation is easily caused, and the surface of the runner cone is eroded are solved.

Description

Technical Field

[0001] The invention relates to the technical field of water turbine runners, and in particular to a telescopic and adjustable water turbine runner water discharge cone and an adjustment method thereof. Background Art

[0002] Water turbines are widely used in hydroelectric power stations. They are the core equipment that converts the kinetic energy of water flow into mechanical energy. The runner of the water turbine is the main component that rotates through the action of water flow and drives the generator.

[0003] The spill cone is a very important component in the turbine. Its main function is to use the cone surface as a guide to guide the water flow to flow quickly and smoothly in the axial direction after it comes out of the runner. The shape and adjustment method of the spill cone have a direct impact on the operating efficiency of the turbine. The spill cone in a traditional turbine generally adopts a fixed structure, which has poor adaptability to water flow, especially under different head and flow conditions. The flow rate is too large, which makes the local pressure of the water flow near the spill cone too low, causing cavitation, seriously damaging the surface of the spill cone, reducing its service life, and causing reduced turbine efficiency and mechanical damage.

[0004] In some areas with abundant hydropower resources but complex water flow conditions, traditional turbines often find it difficult to perform at their best, because the discharge cone in traditional turbines generally adopts a fixed structure. If the discharge cone is too short, the water velocity will be too high, and the water flow will seriously interfere with each other, and even cavitation will occur, reducing the efficiency of the turbine. If the discharge is too long, it will increase the resistance of the water flow, leading to energy loss, reducing equipment efficiency, and increasing the lateral interference force on the discharge cone, causing damage to the connecting bolts. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a telescopic and adjustable turbine runner water discharge cone and an adjustment method, so as to solve the problem in the prior art that when water flows through the water discharge cone, the water discharge cone may generate vortices in certain parts, and the pressure in the vortex area is low, which easily induces cavitation and causes erosion on the surface of the water discharge cone.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides a telescopic and adjustable water-turbine runner water discharge cone, comprising an upper crown, a lower ring and a plurality of blades, wherein a water discharge cone is integrally formed at the bottom of the upper crown, a plurality of blades are connected between the water discharge cone and the lower ring, a plurality of water discharge holes are opened at the top of the upper crown and are communicated with the cavity of the water discharge cone, and further comprising a sleeve, an air-supplementing member, a telescopic member and an air delivery pipe, wherein the upper end of the sleeve is fixedly connected to the lower end of the water discharge cone and is communicated with the cavity, the air-supplementing member is provided with an air-supplementing cavity and the upper end is open. A mouth, a plurality of water leakage holes connected with the air replenishing cavity are arranged at its lower end, an air guide cavity is arranged inside it on the peripheral side of the air replenishing cavity, a plurality of air leakage holes for connecting the air replenishing cavity and the air guide cavity are arranged on the peripheral side near the lower end, the upper end is slidably connected with the sleeve, and the air replenishing cavity is connected with the sleeve via the open mouth, the telescopic part is connected between the sleeve and the air replenishing part, the telescopic part is used to drive the relative sliding between the air replenishing part and the sleeve, and the lower end of the air supply pipe is successively penetrated through the water discharge cone and the sleeve and connected with the air guide cavity.

[0007] In some embodiments, the plurality of drainage holes are evenly distributed along the circumference of the drainage cone.

[0008] In some embodiments, an annular mounting cavity is provided in the sleeve and has an opening at the lower end, the upper end of the air supply component is slidably inserted into the annular mounting cavity through the opening, the telescopic component is fixed in the annular mounting cavity, and the movable end of the telescopic component is fixedly connected to the upper end of the air supply component.

[0009] In some embodiments, the air supply component includes an air supply pipe and a water baffle plate. The upper end of the air supply pipe is slidably inserted into the annular mounting cavity and fixedly connected to the movable end of the telescopic component. The water baffle plate is fixedly arranged at the lower end of the air supply pipe. The air supply cavity is formed between the air supply pipe and the water baffle plate. The air guide cavity is arranged in the air supply pipe. A plurality of air leakage holes are opened at the lower end of the air supply pipe, and a plurality of water leakage holes are opened on the water baffle plate.

[0010] In some embodiments, the telescopic member is two hydraulic cylinders fixedly arranged at intervals in the annular mounting cavity.

[0011] In some embodiments, a rotating shaft is fixedly connected to the top of the upper crown, and a through hole communicating with the cavity is opened in the rotating shaft along the axial direction, and the upper end of the air delivery pipe is passed through the through hole; The upper end of the sleeve is provided with a plurality of wire holes communicating with the annular mounting cavity, and the oil inlet pipe and the oil outlet pipe of the hydraulic cylinder pass through the wire holes and are sequentially passed through the cavity and the through hole.

[0012] In some embodiments, the outer diameter and the inner diameter of the air supply pipe are the same as the outer diameter and the inner diameter of the annular mounting cavity.

[0013] In some embodiments, the length of the gas supplement tube is 1 / 2-2 / 3 of the length of the sleeve.

[0014] In some embodiments, a pressure sensor is provided on the inner wall of the sleeve near the upper end.

[0015] The present invention also provides a method for adjusting a telescopic and adjustable water turbine runner drain cone: S1: When the water flow rate is too high and the local pressure near the water discharge cone is detected to be too low, the air supply component and the sleeve are driven to slide relative to each other through the telescopic component to increase the telescopic length between the air supply component and the sleeve; S2: The air is delivered to the air guide cavity through the air delivery pipe, and the air is delivered to the air guide cavity through multiple air leakage holes to replenish the cavities of the casing and the water discharge cone to eliminate cavitation inside the water discharge cone; S3: When it is detected that the local pressure near the discharge cone is too high, the telescopic member drives the air supply member and the casing to slide relative to each other, shortening the telescopic length between the air supply member and the casing to reduce the lateral interference force of the water flow on the discharge cone and improve the efficiency and stability of the turbine.

[0016] Compared with the prior art, the present invention provides a telescopic and adjustable water turbine runner water discharge cone and an adjustment method, wherein the upper end of the sleeve is fixedly connected to the lower end of the water discharge cone and is connected to the cavity, an air supply cavity is provided in the air supply component and the upper end is open, and a plurality of water leakage holes connected to the air supply cavity are provided at the lower end thereof, an air guide cavity is also provided therein on the peripheral side of the air supply cavity, and a plurality of air leakage holes for connecting the air supply cavity and the air guide cavity are provided on the peripheral side near the lower end thereof, the upper end thereof is slidably connected to the sleeve, and the air supply cavity is connected to the sleeve via the opening, when the local pressure near the water discharge cone is too low, the air supply component and the sleeve are driven to slide relative to each other by the telescopic component, the length of the water discharge cone is extended, and the air supply pipe conveys air flow into the air guide cavity, and the air flow is evenly conveyed to the air supply cavity via the plurality of air leakage holes, so that the cavity of the water discharge cone can be effectively replenished with air, local vacuum is avoided in the water discharge cone, and the service life of the water turbine runner is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a telescopic and adjustable water turbine runner discharge cone provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the internal structure of a telescopic and adjustable water turbine runner discharge cone provided by an embodiment of the present invention; Figure 3 yes Figure 2 A magnified schematic diagram of the middle A area; Figure 4 is a schematic structural diagram of a sleeve provided in an embodiment of the present invention; Figure 5 It is a schematic diagram of the structure of the air replenishing component provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] In order to solve the technical problem in the prior art that the water flow velocity is too high, which will cause the local pressure near the discharge cone to be too low, cavitation will occur, and the surface of the discharge cone will be easily damaged, the present invention provides a telescopic and adjustable turbine runner discharge cone and an adjustment method, which can replenish air in the cavity of the discharge cone and avoid cavitation in the cavity of the discharge cone.

[0020] See also Figure 1-Figure 5 , Figure 1-Figure 5 A telescopic and adjustable water-turbine runner discharge cone in one embodiment of the present invention comprises an upper crown 1, a lower ring 2, a plurality of blades 3, a sleeve 4, an air-supplementing member 5, a telescopic member 6 and an air delivery pipe 7. A discharge cone 11 is integrally formed at the bottom of the upper crown 1, a plurality of blades 3 are connected between the discharge cone 11 and the lower ring 2, a plurality of discharge holes 12 connected to the cavity of the discharge cone 11 are opened at the top of the upper crown 1, the upper end of the sleeve 4 is fixedly connected to the lower end of the discharge cone 11 and connected to the cavity, an air-supplementing cavity 50 is provided in the air-supplementing member 5 and the upper end The air supply pipe 7 is open and has a plurality of water leakage holes 5a connected with the air replenishing cavity at its lower end, and an air guide cavity 5b is also provided on the peripheral side of the air replenishing cavity. A plurality of air leakage holes 5c for connecting the air replenishing cavity with the air guide cavity 5b are provided on the peripheral side near the lower end. The upper end is slidably connected with the sleeve 4, and the air replenishing cavity is connected with the sleeve 4 via the open mouth. The telescopic member 6 is connected between the sleeve 4 and the air replenishing member 5, and the telescopic member 6 is used to drive the relative sliding between the air replenishing member 5 and the sleeve 4. The lower end of the air supply pipe 7 is successively penetrated through the water discharge cone 11 and the sleeve 4 and is connected with the air guide cavity 5b.

[0021] It should be noted that the turbine runner is one of the core components of the turbine and is installed inside the volute. Its main function is to convert the kinetic energy and potential energy of the water flow into mechanical energy, and then drive the generator to generate electrical energy.

[0022] In this specific embodiment, the plurality of drainage holes 12 are evenly distributed along the circumference of the drainage cone 11 ; water can flow into the cavity of the drainage cone 11 through the plurality of drainage holes 12 .

[0023] Specifically, when water flows through the discharge cone, in order to adapt to the shape of the discharge cone, the water flow will accelerate. The increase in flow rate will cause the pressure in this area to decrease. According to Bernoulli's principle, when the speed of the fluid increases, its static pressure will decrease accordingly. If the pressure drops below the saturated vapor pressure of water, the dissolved gas in the water will precipitate to form bubbles, that is, cavitation occurs.

[0024] It should be noted that, in order to facilitate the adjustment of the enlarged length of the water discharge cone, specifically, an annular mounting cavity 4a is provided in the sleeve 4 and the lower end is open, the upper end of the air-filling component 5 is slid through the opening in the annular mounting cavity 4a, the telescopic component 6 is fixed in the annular mounting cavity 4a, and the movable end of the telescopic component 6 is fixedly connected to the upper end of the air-filling component 5.

[0025] The telescopic member 6 is two hydraulic cylinders fixedly arranged in the annular mounting cavity 4a at an interval.

[0026] Specifically, when water flows through the water discharge cone, eddies may be generated in certain parts. The pressure in the eddy current area is relatively low, which can easily cause cavitation. The eddies may also cause the formed bubbles to be carried to the high-pressure area. These bubbles burst rapidly under high pressure, generating strong shock waves and corroding the surrounding materials. By providing a sleeve 4 and an air-filling component 5 slidably connected to the sleeve 4, the sleeve 4 and the air-filling component 5 are driven by a hydraulic cylinder to slide relative to each other, so that the air-filling component 5 extends toward the outside of the sleeve 4, thereby increasing the length of the water discharge cone 11. In addition, under some working conditions, the length of the drainage cone 11 is too long, which will increase the resistance of the water flow, thereby increasing the lateral interference force on the drainage cone. At this time, there will be excessive pressure around the drainage cone, and the hydraulic cylinder drives the sleeve 4 and the air-supplementing member 5 to slide relative to each other, so that the air-supplementing member 5 retracts into the sleeve 4. By shortening the telescopic length of the discharge cone, the lateral interference force on the discharge cone can be reduced, thereby improving the efficiency and stability of the turbine.

[0027] In this specific embodiment, the air supply component 5 includes an air supply pipe 51 and a water baffle 52. The upper end of the air supply pipe 51 is slidably inserted into the annular mounting cavity 4a and fixedly connected to the movable end of the telescopic component 6. The water baffle 52 is fixedly arranged at the lower end of the air supply pipe 51. The air supply cavity is formed between the air supply pipe 51 and the water baffle 52. The air guide cavity 5b is arranged in the air supply pipe 51. A plurality of air leakage holes 5c are opened at the lower end of the air supply pipe 51. A plurality of water leakage holes 5a are opened on the water baffle 52. Specifically, the liquid and gas in the cavity of the water discharge cone 11 can be discharged through the plurality of water leakage holes 5a.

[0028] It should be noted that the turbine runner is connected to the generator set through a rotating shaft 8. Specifically, the top of the upper crown 1 is fixedly connected to the rotating shaft 8, and a through hole 8a connected to the cavity is opened in the rotating shaft 8 along the axial direction, and the upper end of the air pipe 7 is penetrated into the through hole 8a; a plurality of wire holes connected to the annular mounting cavity 4a are opened at the upper end of the casing 4, and the oil inlet pipe and the oil outlet pipe of the hydraulic cylinder pass through the wire holes and are sequentially penetrated into the cavity and the through hole 8a, and the oil inlet pipe and the oil outlet pipe of the hydraulic cylinder are connected to the oil supply assembly.

[0029] In this specific embodiment, the outer diameter and inner diameter of the air supply pipe 51 are the same as the outer diameter and inner diameter of the annular installation cavity 4 a , and the length of the air supply pipe 51 is 1 / 2-2 / 3 of the length of the sleeve 4 .

[0030] On the basis of the above scheme, a pressure sensor 9 is provided on the inner wall near the upper end of the sleeve 4, and the local pressure near the water discharge cone can be detected through the pressure sensor 9. The pressure sensor 9 sends the water discharge cone bearing strength data to the electronic control unit, and the electronic control unit controls the two hydraulic cylinders to drive the sleeve 4 and the air supply pipe 51 to slide relative to each other.

[0031] This scheme also improves a method for adjusting a telescopic and adjustable water turbine runner discharge cone: S1: When the water flow rate is too high and the local pressure near the water discharge cone is detected to be too low, the air supply component and the sleeve are driven to slide relative to each other through the telescopic component to increase the telescopic length between the air supply component and the sleeve; S2: The air is delivered to the air guide cavity through the air delivery pipe, and the air is delivered to the air guide cavity through multiple air leakage holes to replenish the cavities of the casing and the water discharge cone to eliminate cavitation inside the water discharge cone; S3: When it is detected that the local pressure near the discharge cone is too high, the telescopic member drives the air supply member and the casing to slide relative to each other, shortening the telescopic length between the air supply member and the casing to reduce the lateral interference force of the water flow on the discharge cone and improve the efficiency and stability of the turbine.

[0032] It should be noted that the operation method of this device is based on the real-time feedback of the power station operation conditions, through the head H, flow Q and the pressures P1 and P2 of the turbine tailwater pipe and the volute flow channel of the operation conditions, and through the terminal processing, the expanded telescopic length and the jet volume of the discharge cone are judged in real time; the telescopic length control model is controlled according to the control model, and this model requires protection. In the model,

[0033] Among them, L1, L2, L3 and L4 are the telescopic lengths respectively, Q is the operating flow rate, H is the operating head, Hr is the rated head, q is the instantaneous flow rate, P1 and P2 are the volute inlet pressure and the tailwater pipe outlet pressure respectively, p is the instantaneous monitoring pressure, n is the impeller speed, l1, l2, l3 and l4 are the telescopic safety margins respectively.

[0034] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A telescopic and adjustable water turbine runner discharge cone, comprising an upper crown, a lower ring and a plurality of blades, wherein a discharge cone is provided at the bottom of the upper crown, a plurality of blades are connected between the discharge cone and the lower ring, a plurality of discharge holes are provided at the top of the upper crown and are connected to the cavity of the discharge cone, and the characteristics are as follows: It also includes a sleeve, an air-filling part, a telescopic part and an air supply pipe. The upper end of the sleeve is fixedly connected to the lower end of the water discharge cone and is connected to the cavity. The air-filling part is provided with an air-filling cavity and has an open upper end. The lower end is provided with a plurality of water leakage holes connected to the air-filling cavity. An air guide cavity is also provided on the peripheral side of the air-filling cavity. A plurality of air leakage holes for connecting the air-filling cavity and the air guide cavity are provided on the peripheral side near the lower end. The upper end is slidably connected to the sleeve, and the air-filling cavity is connected to the sleeve via the open end. The telescopic part is connected between the sleeve and the air-filling part. The telescopic part is used to drive the relative sliding between the air-filling part and the sleeve. The lower end of the air supply pipe is successively passed through the water discharge cone and the sleeve and is connected to the air guide cavity.

2. The telescopic and adjustable water turbine runner discharge cone according to claim 1, characterized in that: The plurality of drainage holes are evenly distributed along the circumference of the drainage cone.

3. The telescopic and adjustable water turbine runner discharge cone according to claim 1, characterized in that: The sleeve is provided with an annular installation cavity with an opening at the lower end, the upper end of the air-supplementing member is slidably inserted into the annular installation cavity through the opening, the telescopic member is fixedly arranged in the annular installation cavity, and the movable end of the telescopic member is fixedly connected to the upper end of the air-supplementing member.

4. The telescopic and adjustable water turbine runner discharge cone according to claim 3, characterized in that: The air supply component includes an air supply pipe and a water baffle plate. The upper end of the air supply pipe is slidably inserted into the annular mounting cavity and fixedly connected to the movable end of the telescopic component. The water baffle plate is fixedly arranged at the lower end of the air supply pipe. The air supply cavity is formed between the air supply pipe and the water baffle plate. The air guide cavity is arranged in the air supply pipe. A plurality of air leakage holes are opened at the lower end of the air supply pipe. A plurality of water leakage holes are opened on the water baffle plate.

5. The telescopic and adjustable water turbine runner discharge cone according to claim 3, characterized in that: The telescopic parts are two hydraulic cylinders fixedly arranged in the annular installation cavity at intervals.

6. The telescopic and adjustable water turbine runner discharge cone according to claim 3, characterized in that: The top of the upper crown is fixedly connected with a rotating shaft, and a through hole communicating with the cavity is opened in the rotating shaft along the axial direction, and the upper end of the air delivery pipe is passed through the through hole; The upper end of the sleeve is provided with a plurality of wire holes communicating with the annular mounting cavity, and the oil inlet pipe and the oil outlet pipe of the hydraulic cylinder pass through the wire holes and are sequentially passed through the cavity and the through hole.

7. The telescopic and adjustable water turbine runner discharge cone according to claim 4, characterized in that: The outer diameter and inner diameter of the air supply pipe are the same as the outer diameter and inner diameter of the annular installation cavity.

8. The telescopic and adjustable water turbine runner discharge cone according to claim 4, characterized in that: The length of the air supply pipe is 1 / 2-2 / 3 of the length of the sleeve.

9. The telescopic and adjustable water turbine runner discharge cone according to claim 1, characterized in that: A pressure sensor is arranged on the inner side wall near the upper end of the sleeve.

10. A method for adjusting a telescopic and adjustable water turbine runner discharge cone, characterized in that: A telescopic and adjustable water turbine runner discharge cone is applicable to any one of claims 1 to 9, and comprises the following steps: S1: When the water flow rate is too high and the local pressure near the water discharge cone is detected to be too low, the air supply component and the sleeve are driven to slide relative to each other through the telescopic component to increase the telescopic length between the air supply component and the sleeve; S2: The air is delivered to the air guide cavity through the air delivery pipe, and the air is delivered to the air guide cavity through multiple air leakage holes to replenish the cavities of the casing and the water discharge cone to eliminate cavitation inside the water discharge cone; S3: When it is detected that the local pressure near the discharge cone is too high, the telescopic member drives the air supply member and the casing to slide relative to each other, shortening the telescopic length between the air supply member and the casing to reduce the lateral interference force of the water flow on the discharge cone and improve the efficiency and stability of the turbine.

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