A speed limiting device for a wind turbine
By combining agitator and non-Newtonian fluid coolant on the wind turbine shaft, the problems of heat generation and high maintenance costs of friction speed limiting devices are solved, achieving safe and reliable speed limiting and cooling effects for wind turbines.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUIZHOU ELECTRIC POWER DESIGN INST
- Filing Date
- 2023-10-07
- Publication Date
- 2026-05-19
AI Technical Summary
Existing wind turbine speed limiting devices generate a lot of heat when limiting speed through friction, leading to problems such as heat decay and high maintenance costs.
The system employs a first and second agitator mounted on the rotating shaft. By utilizing a combination of non-Newtonian fluid and coolant, centrifugal force is applied to ensure that the rotation is not obstructed under normal wind speeds, but is obstructed by sudden strong winds, thus limiting the speed. Furthermore, the system reduces maintenance costs through cyclical use.
It effectively avoids the heat generated by the friction device, reduces operation and maintenance costs, achieves safe speed limits for wind turbines, and the coolant cools the shaft to prevent high temperatures from affecting the performance of non-Newtonian fluids.
Smart Images
Figure CN117189478B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a wind turbine speed limiting device, belonging to the technical field of wind power auxiliary equipment. Background Technology
[0002] A wind turbine is an electrical device that converts wind energy into mechanical work, which drives the rotor to rotate and ultimately outputs alternating current.
[0003] The rotational speed of a generator rotor is determined by the rotational speed of the wind turbine blades. Within a certain range, the power generation efficiency increases with the increase of the wind turbine blade speed. However, exceeding the designed speed can cause the generator to generate excessive electricity, which can lead to the coil temperature rising and burning out the generator, or excessive current damaging downstream equipment. Therefore, it is necessary to limit the speed of the generator.
[0004] Most existing wind turbines limit speed and restrict blade rotation through friction. However, this friction-based deceleration device generates a lot of heat during operation. If heat is not dissipated in time, it will cause thermal decay and lead to speed limiting failure. At the same time, brake pads are consumables and need to be repaired and replaced from time to time, which increases the operation and maintenance cost of the wind turbine. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a wind turbine speed limiting device to solve the technical problems existing in the prior art.
[0006] The technical solution adopted by this invention is as follows: a wind turbine speed limiting device, comprising a rotating shaft, a first agitator, and a sleeve. The rotating shaft is coaxially fixed to the rotor of the wind turbine. The sleeve is coaxially fixedly sleeved on the outer circumference of the rotating shaft and fixed to the stator of the wind turbine. The first agitator is radially fixed to the rotating shaft. The interior of the first agitator is hollow. A first slider is slidably and sealed inside the first agitator. The first slider is connected to one end of the first agitator near the rotating shaft via a first spring. A first one-way inlet valve and a first one-way outlet valve are provided on the end of the first agitator away from the rotating shaft. The sleeve is filled with a speed limiting fluid, and both the first one-way inlet valve and the first one-way outlet valve are connected to the speed limiting fluid.
[0007] Preferably, the rate-limiting fluid is a non-Newtonian fluid.
[0008] Preferably, the number of the first stirring paddles is set to one or more and they are evenly distributed circumferentially about the axis of the rotating shaft.
[0009] Preferably, a second stirring paddle is radially fixed to the outer circumference of the rotating shaft, and a partition is fixed between the first stirring paddle and the second stirring paddle. The partition separates the speed-limiting fluid from the rotating shaft. The cavity between the partition and the rotating shaft is a coolant cavity, which is filled with coolant. The interior of the second stirring paddle is hollow, and a second slider is slidably and sealed to the interior of the second stirring paddle. The second slider is connected to one end of the second stirring paddle near the rotating shaft via a second spring. A second one-way inlet valve and a second one-way outlet valve are provided on the end of the second stirring paddle away from the rotating shaft. Both the second one-way inlet valve and the second one-way outlet valve are connected to the coolant.
[0010] Preferably, the coolant is water.
[0011] Preferably, the number of the second stirring paddles is set to one or more and they are evenly distributed circumferentially about the axis of the rotating shaft; the first stirring paddles and the second stirring paddles are arranged at alternating intervals.
[0012] Preferably, the end of the first stirring paddle away from the rotating shaft is slidably and sealingly connected to the inner wall of the sleeve.
[0013] Preferably, the end of the second stirring paddle away from the rotating shaft is slidably and sealingly connected to the inner wall of the sleeve.
[0014] The beneficial effects of this invention are as follows: Compared with the prior art, in this invention, during the normal rotation of the wind turbine blades, the blades drive the shaft to rotate, generating centrifugal force. The non-Newtonian fluid inside the first agitator is squeezed into the speed-limiting liquid chamber by the first slider. Since the blade rotation speed is relatively slow at this time, the non-Newtonian fluid, being in a liquid state, does not obstruct the rotation of the first agitator. Simultaneously, the cooling water inside the second agitator is squeezed into the cooling liquid chamber by the second slider. The cooling water separates the shaft from the non-Newtonian fluid. On the one hand, the cooling water can cool the shaft; on the other hand, it can prevent the high temperature of the shaft from being transferred to the non-Newtonian fluid, thus affecting its performance. When a sudden strong wind blows, the first and second agitators suddenly apply a large, sudden impact force to the non-Newtonian fluid, causing it to instantly solidify and obstruct the rotation of the first and second agitators, thereby limiting the speed. The deceleration fluid in this invention is recyclable, reducing maintenance costs and avoiding the problem of excessive heat generated by friction devices in the prior art. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the overall structure.
[0016] Figure 2 yes Figure 1 Enlarged view of section A.
[0017] Figure 3 yes Figure 1 Enlarged view of section B in the middle. Detailed Implementation
[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0019] The reference numerals in the accompanying drawings include: rotating shaft 10, first agitator 20, first slider 21, first spring 22, first one-way inlet valve 23, first one-way outlet valve 24, partition 30, coolant chamber 31, speed limiting chamber 32, second agitator 40, second slider 41, second spring 42, second one-way inlet valve 43, second one-way outlet valve 44, and sleeve 50.
[0020] Example 1:
[0021] A wind turbine speed limiting device, such as Figure 1 As shown, the device includes a rotating shaft 10, a first agitator 20, a second agitator 40, and a sleeve 50. The rotating shaft 10 is coaxially fixed to the rotor of the wind turbine. The sleeve 50 is coaxially fixedly sleeved on the outer circumference of the rotating shaft 10 and fixed to the stator of the wind turbine. The sleeve 50 is a hollow cylinder. The rotating shaft 10 and the sleeve 50 are rotatably sealed together. The first agitator 20 is radially fixed to the rotating shaft 10. The end of the first agitator 20 away from the rotating shaft 10 is slidably sealed to the inner wall of the sleeve 50. The interior of the first agitator 20 is hollow. A first slider 21 is slidably sealed to the interior of the first agitator 20. A first spring 22 is provided inside the first agitator 20. One end of the first spring 22 is connected to the first slider 21, and the other end of the first spring 22 is connected to the end of the first agitator 20 near the rotating shaft 10. Figure 2 As shown, a first one-way inlet valve 23 and a first one-way outlet valve 24 are provided on the end of the first stirring paddle 20 away from the rotating shaft 10; as Figure 1 As shown, the number of first stirring paddles 20 is set to 2 and they are evenly distributed circumferentially about the axis of the rotating shaft 10.
[0022] like Figure 1As shown, a second stirring paddle 40 is fixed radially around the outer periphery of the rotating shaft 10. Two second stirring paddles 40 are evenly distributed circumferentially about the axis of the rotating shaft 10. The first stirring paddle 20 and the second stirring paddle 40 are arranged alternately. A partition 30 is fixed between each first stirring paddle 20 and the adjacent second stirring paddle 40. The partition 30 is a hollow, fan-shaped column, and its length is equal to the length of the sleeve 50. Thus, the partition 30 separates the velocity-limiting fluid from the rotating shaft 10. The cavity between the partition 30 and the rotating shaft 10 is a coolant cavity 31, filled with coolant (in this embodiment, the coolant is water). The cavity between the partition 30 and the sleeve 50 is a velocity-limiting fluid cavity 32, filled with a velocity-limiting fluid (in this embodiment, the velocity-limiting fluid is a non-Newtonian fluid). Figure 2 As shown, both the first one-way inlet valve 23 and the first one-way outlet valve 24 are connected to the rate-limiting fluid via pipelines. Figure 1 As shown, the second stirring paddle 40 is hollow inside, and a second slider 41 is slidably and sealed inside the second stirring paddle 40. A second spring 42 is installed inside the second stirring paddle 40. One end of the second spring 42 is connected to the second slider 41, and the other end of the second spring 42 is connected to the end of the second stirring paddle 40 near the rotating shaft 10. Figure 3 As shown, a second one-way inlet valve 43 and a second one-way outlet valve 44 are provided on the end of the second agitator 40 away from the rotating shaft 10. Both the second one-way inlet valve 43 and the second one-way outlet valve 44 are connected to the coolant through pipes.
[0023] like Figure 1 As shown, the end of the second stirring paddle 40 away from the rotating shaft 10 is slidably sealed to the inner wall of the sleeve 50.
[0024] The specific implementation process is as follows:
[0025] In the initial state, the fan blades are stationary. The first slider 21 is located inside the first agitator 20 near the shaft 10 under the force of the first spring 22. The first agitator 20 is filled with a non-Newtonian fluid. The second slider 41 is located inside the second agitator 40 near the shaft 10 under the force of the second spring 42. The second agitator 40 is filled with coolant.
[0026] When the wind picks up, the fan blades rotate, causing the shaft 10 to rotate and generating centrifugal force. Under the action of centrifugal force, the first slider 21 and the second slider 41 move towards the sleeve 50. Positive pressure is generated inside the first agitator 20, the first one-way inlet valve 23 closes, and the first one-way outlet valve 24 opens. The non-Newtonian fluid inside the first agitator 20 is squeezed into the speed-limiting liquid chamber 32 by the first slider 21. Since the fan blades rotate slowly at this time, the non-Newtonian fluid is in a liquid state and will not obstruct the rotation of the first agitator 20. At the same time, positive pressure is generated inside the second agitator 40, the second one-way inlet valve 43 closes, and the second one-way outlet valve 44 opens. The cooling water inside the second agitator 40 is squeezed into the cooling liquid chamber 31 by the second slider 41. The cooling water separates the shaft 10 from the non-Newtonian fluid. On the one hand, the cooling water can cool the shaft 10, and on the other hand, the cooling water can prevent the high temperature of the shaft 10 from being transferred to the non-Newtonian fluid and affecting its performance.
[0027] When a sudden strong wind blows, the turbine blades drive the shaft 10 to rotate rapidly. The shaft 10 then drives the first agitator 20 and the second agitator 40 to rotate rapidly. This is equivalent to the first and second agitators 20 and 40 suddenly applying a large, sudden impact force to the non-Newtonian fluid. The non-Newtonian fluid instantly becomes solid, blocking the rotation of the first and second agitators 20 and 40, thus limiting its speed. After a period of time, the state of the non-Newtonian fluid stabilizes, its viscosity decreases again and it exhibits fluid properties, and the strong wind dissipates. At this point, the blades can continue rotating to generate electricity.
[0028] When the wind disappears, the centrifugal force disappears, and the first slider 21 moves toward the rotating shaft 10 under the action of the first spring 22. A negative pressure is generated inside the first stirring paddle 20, the first one-way inlet valve 23 opens, the first one-way outlet valve 24 opens, and the first stirring paddle 20 draws in non-Newtonian fluid from the speed-limiting liquid chamber 32; the second slider 41 moves toward the rotating shaft 10 under the action of the second spring 42, a negative pressure is generated inside the second stirring paddle 40, the second one-way inlet valve 43 opens, the second one-way outlet valve 44 opens, and the second stirring paddle 40 draws in cooling water from the cooling liquid chamber 31.
[0029] Repeat the operation when the wind picks up again.
[0030] The deceleration fluid in this embodiment can be recycled, which can reduce operation and maintenance costs and avoid the problem of a large amount of heat generated by the friction device in the prior art.
[0031] In the event of persistent strong winds, existing braking devices can be used to stop the wind turbine blades from rotating in order to protect the wind turbine.
[0032] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.
Claims
1. A wind turbine speed limiting device, characterized in that: The device includes a rotating shaft, a first agitator, and a sleeve. The rotating shaft is coaxially fixed to the rotor of a wind turbine. The sleeve is coaxially fixedly fitted around the outer circumference of the rotating shaft and fixed to the stator of the wind turbine. The first agitator is radially fixed to the rotating shaft and is hollow inside. A first slider is slidably sealed inside the first agitator and connected to one end of the first agitator near the rotating shaft via a first spring. A first one-way inlet valve and a first one-way outlet valve are provided on the end of the first agitator away from the rotating shaft. The sleeve is filled with a pressure-limiting fluid, and both the first one-way inlet valve and the first one-way outlet valve are connected to the pressure-limiting fluid. The rate-limiting fluid is a non-Newtonian fluid; The number of the first stirring paddles is set to one or more and they are evenly distributed circumferentially about the axis of the rotating shaft; A second stirring paddle is radially fixed to the outer circumference of the rotating shaft. A partition is fixed between the first stirring paddle and the second stirring paddle, separating the speed-limiting fluid from the rotating shaft. The cavity between the partition and the rotating shaft is a coolant cavity, which is filled with coolant. The second stirring paddle is hollow inside, and a second slider is slidably sealed inside the second stirring paddle. The second slider is connected to one end of the second stirring paddle near the rotating shaft via a second spring. A second one-way inlet valve and a second one-way outlet valve are provided on one end of the second stirring paddle away from the rotating shaft. Both the second one-way inlet valve and the second one-way outlet valve are connected to the coolant. The coolant is water; The number of the second stirring paddles is set to one or more and they are evenly distributed circumferentially about the axis of the rotating shaft; the first stirring paddles and the second stirring paddles are arranged at alternating intervals. The end of the first stirring paddle away from the rotating shaft is slidably and sealingly connected to the inner wall of the sleeve; The end of the second stirring paddle away from the rotating shaft is slidably and sealed to the inner wall of the sleeve.