Water turbine blade tail corrosion and vibration reduction device
By setting up an air injection device on the side wall of the turbine volute shell to inject water and gas mixture into the rotor chamber, the problems of vibration and damage of the tail of the blade are solved, and better corrosion and shock absorption effects are achieved.
Patent Information
- Application Number
- CN202422556814.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-22
AI Technical Summary
During the operation of the turbine, the tail of the blade is vibrated and damaged due to vortex belt disturbance. The existing air replenishment method cannot effectively protect the tail of the blade, especially when operating at high speed.
The air injection device is arranged on the side wall of the volute. The air injection device is used to inject water and gas mixture into the rotor chamber, and the vortex belt is destroyed by gas to reduce cavitation and vibration of the blades. The air injection device includes a shell, a water inlet pipe, an air inlet pipe and an air injection pipe. The gas is predispersed in the shell to form tiny bubbles and then enters the rotor chamber.
It effectively reduces cavitation and vibration at the tail of the blade, improves the protection effect of the blade, and better distributes gases than traditional gas replenishment methods, and enhances corrosion reduction and shock absorption effects.
Smart Images
Figure CN223136306U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of water turbines, and more specifically, to an erosion and vibration reduction device for the tail of a water turbine blade. Background Technique
[0002] When the water turbine operates at 40%-70% of the rated output, due to water flow disturbance, there are varying degrees of pressure pulsation, and a vortex band appears in the draft tube. Due to the strong disturbance of the vortex band or the coincidence of its frequency with the natural frequency of the unit, resonance occurs, which will cause the vibration of the unit or the swing of the load; the vortex band will also damage the flow-through surface of the water turbine, causing cavitation or cracks in the flow-through components.
[0003] Therefore, it is necessary to supplement air when the water turbine unit is in an unstable working condition to destroy the vortex band, thereby absorbing vibration and reducing the vortex intensity, and improving the operation condition of the unit.
[0004] At present, the most common air supply methods for water turbines are draft tube air supply and main shaft center hole air supply. Draft tube air supply is usually used for small and medium-sized units, and main shaft center hole air supply is usually used for medium and large-sized units. The air supply to the center of the water turbine main shaft is to supply air to the outlet of the runner where the runner discharge cone is located through the center hole of the main shaft. However, such draft tube air supply and main shaft air supply can usually only solve the problems at the axis of the runner tail. However, when the water turbine (especially the reaction water turbine) runs at high speed, severe disturbances and cavitation phenomena will also occur at the tail of its blades. Such phenomena will not only cause vibration and damage to the blade tail, but also accumulate to the tail of the runner. Therefore, it is also necessary to reduce vibration and erosion at the tail of the water turbine blade. Content of the Utility Model
[0005] The purpose of the utility model is to provide an erosion and vibration reduction device for the tail of a water turbine blade, which can effectively protect the tail of the blade by supplying air to the side wall of the volute.
[0006] The erosion and vibration reduction device for the tail of the water turbine blade of the utility model comprises a volute, a water guide pipe communicated with the side wall of the volute, a runner chamber communicated with the bottom of the volute, guide vanes arranged in the volute, a runner arranged in the runner chamber, and an air injection device arranged on the outer wall of the runner chamber; the air injection device comprises a housing, a water inlet pipe communicated with the housing, an air inlet pipe communicated with the housing, and an air injection pipe arranged on the side wall of the housing; an air injection hole is formed on the outer wall of the runner chamber, and the air injection pipe passes through the air injection hole; the air inlet pipe is connected with an air compressor, and the water inlet pipe is connected with a water pump.
[0007] Furthermore, the air injection pipe is arranged on the upper side wall of the housing.
[0008] Furthermore, a plurality of gas injection pipes are provided, and a plurality of gas injection holes are provided; one of the gas injection pipes is disposed in one of the gas injection holes.
[0009] Furthermore, a horizontally disposed partition plate is provided inside the housing, and a plurality of water permeable holes are provided on the partition plate; the water inlet pipe is disposed below the partition plate, and the air inlet pipe and the gas injection pipe are disposed above the partition plate.
[0010] Furthermore, the water permeable holes are disposed at one end of the partition plate away from the gas injection holes; the air inlet pipe is disposed close to the water permeable holes.
[0011] Furthermore, a plurality of air inlet pipes are provided, and the plurality of air inlet pipes are at the same height, and the plurality of air inlet pipes are all connected to the air compressor.
[0012] Furthermore, one-way valves are provided on both the air inlet pipe and the water inlet pipe.
[0013] Furthermore, a plurality of gas injection devices are provided, and the plurality of gas injection devices are circumferentially distributed along the outer wall of the runner chamber; the plurality of gas injection devices are all disposed above the runner.
[0014] The technical solution of the present utility model has at least the following advantages and beneficial effects: The erosion and vibration reduction device for the tail of the water turbine blade of the present utility model is based on the existing axial flow reaction water turbine, and a gas injection device is provided on the outer wall of the runner chamber. The gas-water mixture is injected into the runner chamber through the gas injection device. The gas in the gas-water mixture enters the runner chamber, contacts the runner and the cavitation bubbles in the water, destroys the vortex band, reduces the cavitation and vibration of the blade. Compared with air supply from the draft tube and the central hole of the main shaft, air supply from the side wall of the runner chamber can make the gas disperse better in the runner chamber, distribute better on the wall surface of the runner chamber, and contact better with the tail of the runner blade. Therefore, it can be used as a supplementary air supply for air supply from the draft tube and the central hole of the main shaft (that is, it does not exist alone), and at the same time, water and gas are introduced into the housing, so that the gas is dispersed in the water in the housing in advance, and then enters the runner chamber after forming smaller bubbles, so that it can have better erosion and vibration reduction effects. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0016] Figure 1 It is a schematic structural diagram of the erosion and vibration reduction device for the tail of the water turbine blade provided by the embodiment of the present utility model;
[0017] Figure 2 This is a schematic diagram of the internal structure of the erosion and vibration reduction device at the tail of the water turbine blade provided by the embodiment of the present utility model;
[0018] Figure 3 This is a schematic diagram of the structure of the gas injection device part provided by the embodiment of the present utility model;
[0019] Figure 4 This is a schematic diagram of the internal structure of the gas injection device provided by the embodiment of the present utility model.
[0020] Reference numerals: 11 - volute, 12 - draft tube, 13 - runner chamber, 14 - runner, 20 - gas injection device, 21 - housing, 22 - intake pipe, 23 - water inlet pipe, 24 - gas injection pipe, 25 - partition board, 26 - water permeable hole. Detailed implementation manners
[0021] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Generally, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.
[0022] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts fall within the scope of protection of the present utility model.
[0023] It should be noted that: like reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0024] In the description of the present utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. It is only for the convenience of describing the present utility model 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 therefore should not be construed as a limitation of the present utility model.
[0025] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, if the terms "set", "installed", "connected", and "connected" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0026] Embodiment
[0027] The following is further described in conjunction with specific embodiments. As shown in the attached Figure 1 - attached Figure 4 As shown, the erosion and vibration reduction device for the tail of the water turbine blade in this embodiment includes a volute 11, a water guide pipe 12 communicating with the side wall of the volute 11, a runner chamber 13 communicating with the bottom of the volute 11, guide vanes arranged in the volute 11, a runner 14 arranged in the runner chamber 13, and an air injection device 20 arranged on the outer wall of the runner chamber 13; the air injection device 20 includes a housing 21, a water inlet pipe 23 communicating with the housing 21, an air inlet pipe 22 communicating with the housing 21, and an air injection pipe 24 arranged on the side wall of the housing 21; an air injection hole is opened on the outer wall of the runner chamber 13, and the air injection pipe 24 passes through the air injection hole; the air inlet pipe 22 is connected with an air compressor, and the water inlet pipe 23 is connected with a water pump. Specifically, on the basis of the existing axial flow reaction water turbine, an air injection device 20 is arranged on the outer wall of the runner chamber 13, and a water-gas mixture is injected into the runner chamber 13 through the air injection device 20. The gas in the water-gas mixture enters the runner chamber 13, contacts the runner 14 and the air bubbles in the water, destroys the vortex band, reduces the cavitation and vibration of the blade. Compared with air injection from the draft tube and the central hole of the main shaft, air injection from the side wall of the runner chamber 13 can make the gas disperse better in the runner chamber 13, distribute better on the wall surface of the runner chamber 13, and contact the tail of the runner 14 blade better. Therefore, it can be used as a supplementary air injection for air injection from the draft tube and the central hole of the main shaft (that is, it does not exist alone), and water and gas are simultaneously introduced into the housing 21, so that the gas is dispersed in the water in the housing 21 in advance, forms smaller bubbles and then enters the runner chamber 13, so that it can have a better erosion and vibration reduction effect.
[0028] In this embodiment, the air injection pipe 24 is arranged on the upper side wall of the housing 21. Specifically, in this way, the gas-liquid mixture can be discharged from the housing 21 better.
[0029] In this embodiment, there are multiple air injection pipes 24 and multiple air injection holes; one air injection pipe 24 is arranged in one air injection hole.
[0030] In the housing 21 of this embodiment, a horizontally arranged partition plate 25 is provided, and a plurality of water permeable holes 26 are provided on the partition plate 25; the water inlet pipe 23 is arranged below the partition plate 25, and the air inlet pipe 22 and the gas injection pipe 24 are arranged above the partition plate 25. Specifically, the water pump sends water into the housing 21 through the water inlet pipe 23, then it passes through the water permeable holes 26 on the partition plate 25 and contacts the gas sent by the air compressor, and finally enters the runner chamber 13 from the gas injection pipe 24 under the combined action of water pressure and air pressure.
[0031] In this embodiment, the water permeable holes 26 are arranged at one end of the partition plate 25 far from the gas injection holes; the air inlet pipe 22 is arranged close to the water permeable holes 26. Specifically, in this way, the water can better contact and mix with the gas and then be discharged.
[0032] In this embodiment, a plurality of air inlet pipes 22 are provided, and the plurality of air inlet pipes 22 are at the same height, and the plurality of air inlet pipes 22 are all connected to the air compressor.
[0033] In this embodiment, one-way valves are provided on both the air inlet pipe 22 and the water inlet pipe 23. Specifically, the setting of the one-way valves can effectively prevent the gas and water from flowing back.
[0034] In this embodiment, a plurality of gas injection devices 20 are provided, and the plurality of gas injection devices 20 are circumferentially distributed along the outer wall of the runner chamber 13; the plurality of gas injection devices 20 are all arranged above the runner 14.
[0035] In summary, for the erosion and vibration reduction device at the tail of the water turbine blade in this embodiment, on the basis of the existing axial flow reaction water turbine, a gas injection device 20 is arranged on the outer wall of the runner chamber 13, and a water-gas mixture is injected into the runner chamber 13 through the gas injection device 20. The gas in the water-gas mixture enters the runner chamber 13, contacts the runner 14 and the cavitation bubbles in the water, destroys the vortex band, reduces the cavitation and vibration of the blade. Compared with air injection from the draft tube and air injection from the central hole of the main shaft, air injection from the side wall of the runner chamber 13 can make the gas disperse better in the runner chamber 13, distribute better on the wall surface of the runner chamber 13, and contact better with the tail of the runner 14 blade. Therefore, it can be used as a supplementary air injection for air injection from the draft tube and air injection from the central hole of the main shaft (that is, it does not exist alone), and water and gas are simultaneously introduced into the housing 21, so that the gas is dispersed in the water in the housing 21 in advance, forms smaller bubbles and then enters the runner chamber 13, so that it can have better erosion and vibration reduction effects.
[0036] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A device for reducing erosion and vibration at the tail of a water turbine blade, comprising a spiral case (11), a water guide pipe (12) communicated with the side wall of the spiral case (11), a runner chamber (13) communicated with the bottom of the spiral case (11), guide vanes arranged in the spiral case (11), and a runner (14) arranged in the runner chamber (13), characterized in that: It includes an air injection device (20) provided on the outer wall of the runner chamber (13); the air injection device (20) includes a housing (21), a water inlet pipe (23) communicated with the housing (21), an air inlet pipe (22) communicated with the housing (21), and an air injection pipe (24) provided on the side wall of the housing (21); An air injection hole is provided on the outer wall of the runner chamber (13), and the air injection pipe (24) is arranged through the air injection hole; the air inlet pipe (22) is connected with an air compressor, and the water inlet pipe (23) is connected with a water pump.
2. The erosion and vibration reduction device for the trailing edge of a water turbine blade according to claim 1, characterized in that: The air injection pipe (24) is provided on the upper side wall of the housing (21).
3. The erosion and vibration reduction device for the tail of a water turbine blade according to claim 1, characterized in that: A plurality of the air injection pipes (24) are provided, and a plurality of the air injection holes are provided; one of the air injection pipes (24) is arranged in one of the air injection holes.
4. The erosion and vibration reduction device for the tail of a water turbine blade according to claim 2, characterized in that: A horizontally arranged partition plate (25) is provided in the housing (21), and a plurality of water permeable holes (26) are provided on the partition plate (25); The water inlet pipe (23) is provided below the partition plate (25), and the air inlet pipe (22) and the air injection pipe (24) are provided above the partition plate (25).
5. The erosion and vibration reduction device for the tail of a water turbine blade according to claim 4, wherein: The water permeable holes (26) are provided at one end of the partition plate (25) away from the air injection hole; the air inlet pipe (22) is arranged close to the water permeable holes (26).
6. The erosion and vibration reduction device for the tail of a hydraulic turbine blade according to claim 1, wherein: A plurality of the air inlet pipes (22) are provided, and the plurality of air inlet pipes (22) are at the same height, and the plurality of air inlet pipes (22) are all connected with the air compressor.
7. The erosion and vibration reduction device for the tail of a hydraulic turbine blade according to claim 1, characterized in that: One-way valves are provided on both the air inlet pipe (22) and the water inlet pipe (23).
8. The erosion and vibration reduction device for the tail of a water turbine blade according to any one of claims 1-7, characterized in that: A plurality of the air injection devices (20) are provided, and the plurality of air injection devices (20) are circumferentially distributed along the outer wall of the runner chamber (13) evenly; the plurality of air injection devices (20) are all provided above the runner (14).