A ventilation and heat dissipation structure for improving heat dissipation performance of a wind turbine generator

Abstract

The application discloses a ventilation and heat dissipation structure for improving heat dissipation performance of a wind turbine generator, which comprises a paddle and a gear box arranged behind the paddle, the gear box is coaxially arranged with the rotating shaft of the paddle, an air outlet is arranged on the upper surface of the gear box, the air outlet is communicated with the inside of the gear box, a radiator is arranged on the upper surface of the gear box at the side of the air outlet, a ventilation cover is arranged on the air outlet, the ventilation cover comprises a front cover plate adjacent to the paddle, a rear cover plate away from the paddle, and side plates connected with the side of the front cover plate and the side of the rear cover plate respectively, the front cover plate, the rear cover plate, the side plates and the gear box form a flow guide cavity, and the other side of the front cover plate, the other side of the rear cover plate and the upper surface of the gear box form an air outlet. The flow guide cavity has a flow regulating effect, collects high-temperature air flow from the gear box, the high-temperature air flow discharged from the air outlet can avoid hitting the radiator behind, and with the rotation characteristics of the central vortex, the high-temperature air flow can be more away from the radiator, so that the heat dissipation performance of the radiator is ensured.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and in particular to a ventilation and heat dissipation structure for improving the heat dissipation performance of wind turbines. Background Technology

[0002] In recent years, with the increasing power rating of wind turbines, the heat dissipation capacity of these units has also increased significantly. Traditionally, gearboxes and generators typically employ air cooling, where high-power fans within the nacelle provide forced convection cooling. This method, using air as the heat transfer medium, has relatively low efficiency and requires considerable space. When the power rating of the generator set is high, both the cooling effect and the spatial layout struggle to meet the cooling requirements of the components. Therefore, high-power wind turbines are gradually shifting from air cooling to liquid cooling, which improves cooling efficiency and allows for a more compact and flexible spatial layout. Liquid cooling can be categorized into single-component liquid cooling and integrated liquid cooling. Single-component liquid cooling focuses on cooling a single component and is currently the primary design approach. Integrated liquid cooling, on the other hand, integrates multiple components into a single unit, requiring comprehensive consideration of the components' heat dissipation performance and key parameters, making the design more complex.

[0003] The liquid cooling design primarily involves adding a liquid cooling circulation system, including a pump station, radiators, and piping. The cooling process involves the coolant absorbing heat generated by the gearbox or generator, causing the coolant temperature to rise. The pump then pumps the hot coolant to the radiator. Under the influence of external natural wind, the temperature difference between the internal and external media carries away the heat from the coolant, lowering its temperature. The coolant then returns to the gearbox or generator to continue absorbing heat, completing the cooling cycle. The most uncontrollable factor in the liquid cooling cycle is the external ambient temperature, which constantly changes with the weather. Since the radiator's principle relies on the temperature difference between the internal and external media for heat exchange, the temperature of the airflow blowing onto the radiator surface is crucial to the gearbox or generator's heat dissipation efficiency.

[0004] The cooling of high-power wind turbines is currently at the critical point between air cooling and liquid cooling, meaning that air cooling is difficult to meet heat dissipation requirements, while liquid cooling is relatively expensive. This leads to hybrid cooling designs, such as air cooling for the gearbox and liquid cooling for the generator. Conventionally, the gearbox is located in front of the generator, and the ventilation hood exhausts air directly to the rear. The design of the ventilation hood has the following three effects: (1) It affects the exhaust back pressure of the gearbox cooler fan, affecting the exhaust volume, and thus affecting the heat dissipation performance of the gearbox cooling system; (2) The exhaust temperature of the ventilation hood can reach up to 60 degrees Celsius. Such high temperatures will raise the temperature of the airflow flowing through the generator liquid-cooled radiator, seriously affecting the heat exchange performance of the radiator, and thus affecting the performance of the generator; (3) The ventilation hood is relatively high, which easily generates a large wake area, affecting the airflow velocity at the bottom of the radiator, thus reducing the heat exchange efficiency of the radiator. Therefore, a reasonable ventilation hood design is crucial for the cooling effect of the gearbox and generator. Summary of the Invention

[0005] The present invention aims to overcome the problem that the hot air exhaust from the ventilation hood of the gearbox of the existing wind turbine affects the heat dissipation efficiency of the radiator and thus affects the heat dissipation performance of the wind turbine. The invention provides a ventilation and heat dissipation structure that improves the heat dissipation performance of the wind turbine by improving the exhaust direction of the ventilation hood.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine includes blades and a gearbox disposed behind the blades. The gearbox is coaxially arranged with the blade shaft. An exhaust port is provided on the upper surface of the gearbox and communicates with the interior of the gearbox. A radiator is provided on one side of the exhaust port on the upper surface of the gearbox. A ventilation hood is provided on the exhaust port. The ventilation hood includes: a front cover plate adjacent to the blades, a rear cover plate away from the blades, and side plates connected to one side of the front cover plate and one side of the rear cover plate, respectively. The front cover plate, the rear cover plate, the side plates, and the gearbox together form a flow guide cavity. The other side of the front cover plate, the other side of the rear cover plate, and the upper surface of the gearbox together form an air outlet. The ventilation hood features a single-sided opening. The guide cavity between the ventilation hood and the upper surface of the gearbox has a rectifying effect, collecting the high-temperature airflow from the gearbox, reducing exhaust back pressure, and allowing the airflow to exit more smoothly. The high-temperature airflow exiting the outlet can avoid hitting the radiator behind it. At the same time, with the help of the rotational characteristics of the central vortex, the high-temperature airflow will move further away from the radiator, ensuring the radiator's heat dissipation performance. Meanwhile, the rotation of the wind turbine blades will generate a backflow. The airflow separates at the separation point at the ventilation hood's exhaust outlet. After the airflow separation, a low-pressure area will be formed at the ventilation hood's exhaust outlet. This low-pressure area has a certain suction effect, which helps the high-temperature airflow inside the ventilation hood to exit smoothly, increasing the exhaust flow rate and improving the heat dissipation performance of the gearbox's lubrication system.

[0008] Preferably, the front end cover includes an inclined transition section and a flat section at one end of the inclined transition section. The other end of the inclined transition section is connected to the upper surface of the gearbox. One end of the flat section is connected to the inclined transition section, and the other end of the flat section is connected to one end of the rear end cover. The connection between the inclined transition section and the flat section adopts a rounded, streamlined transition. The inclined transition section and streamlined structure at the front end of the ventilation cover allow the airflow to flow close to the wall without separation on the upper surface of the ventilation cover. According to the Candareen effect, the airflow will be deflected downwards to a certain extent at the tail of the flat section of the ventilation cover, increasing the airflow velocity at the bottom of the radiator, thereby improving the heat dissipation performance and enhancing the heat dissipation performance of the wind turbine. The streamlined characteristics of the ventilation cover minimize the wake area it generates.

[0009] Preferably, when viewed from the back of the gearbox towards the blades, the air outlet is located on the right side of the ventilation shroud when the blades rotate counterclockwise, and on the left side when the blades rotate clockwise. During the rotation of the wind turbine blades, tip vortices and central vortices are generated. The central vortex rotates in the opposite direction to the rotational direction. A strong central vortex alters the flow field in front of the radiator. For example, when the blades rotate counterclockwise, the strong central vortex causes the high-temperature airflow exiting the ventilation shroud to tend to rotate clockwise. If the ventilation shroud outlet is located on the left side, the high-temperature airflow will directly hit the radiator under the influence of the central vortex, affecting heat dissipation performance. By placing the ventilation shroud outlet on the right side, the influence of the central vortex on the radiator can be avoided.

[0010] Preferably, the front end cover is divided into a left front end cover and a right front end cover, with the left and right front end covers forming an obtuse angle facing away from the blades. This causes the airflow at the outlet to deflect backward, which facilitates the smooth discharge of high-temperature airflow, increases the exhaust flow rate, and thus improves heat dissipation performance.

[0011] Preferably, the rear end cover includes an upper cover and a rear wall connected to the upper cover. The upper cover includes a left cover and a right cover symmetrically arranged along the central axis. The left and right cover gradually descend from the central axis to both sides, forming inclined surfaces. This ensures that the airflow flows along the wall of the ventilation cover surface, avoiding flow separation.

[0012] Preferably, the radiator includes a radiator panel disposed perpendicular to the back of the gearbox, and the distance X between the lower edge of the ventilation shroud back plate and the radiator panel satisfies: Where v is the outlet wind speed, ω is the rotor speed, h is the height difference between the outlet side cover and the upper surface of the gearbox, β is the obtuse angle formed between the left and right front cover plates facing away from the blades, and C is a set coefficient whose value is related to the wind speed v and rotor speed ω. The higher the rotor speed ω and the greater the wind speed v, the smaller the value of C. The distance between the radiator and the ventilation cover can prevent the radiator from being affected by the wake area of ​​the air outlet from the ventilation cover, thus improving the generator's heat dissipation performance.

[0013] Preferably, the angle α between the plane of the inclined transition section and the plane of the upper surface of the gearbox satisfies: 10°≤α≤60°. The inclined transition section and streamlined structure at the front end of the ventilation hood allow the airflow to flow close to the wall without separation on the upper surface of the ventilation hood. According to the Candlestick effect, the airflow will be deflected downwards to a certain extent at the tail of the flat section of the ventilation hood, increasing the airflow velocity at the bottom of the radiator, thereby improving heat dissipation performance and enhancing the heat dissipation performance of the wind turbine. The streamlined characteristics of the ventilation hood minimize the wake region it generates.

[0014] Therefore, the present invention has the following beneficial effects:

[0015] (1) The ventilation hood has air outlet on one side, which can firstly prevent the high-temperature airflow caused by the rotation of the central vortex from hitting the generator liquid cooler and affecting the generator's heat dissipation performance; secondly, it can utilize the rotation characteristics of the central vortex to make the high-temperature airflow discharged from the ventilation hood further away from the external radiator, thereby improving the generator's heat dissipation performance.

[0016] (2) The guide cavity between the ventilation hood and the upper surface of the gearbox has a rectifying effect, which gathers the high-temperature airflow from the gearbox, reduces the exhaust back pressure, and makes the airflow discharge more smoothly, which is beneficial to the heat dissipation of the gearbox lubrication system.

[0017] (3) The airflow forms flow separation at the front edge of the ventilation hood, and a low-pressure area is formed in the air outlet area of ​​the ventilation hood. The low-pressure area has a certain suction effect, which helps the high-temperature airflow to be discharged smoothly and improves the heat dissipation performance of the gearbox lubrication system.

[0018] (4) The ventilation hood is designed with a streamlined shape and the front end of the ventilation hood has a certain tilt angle. The transition area between the tilted transition section and the flat section adopts a rounded transition to ensure that the airflow flows along the wall of the ventilation hood surface, avoids flow separation, reduces the wake area generated by the ventilation hood, and the distance between the radiator and the ventilation hood should be able to avoid the influence of the wake area and improve the heat dissipation performance of the generator.

[0019] (5) The airflow flows along the wall of the ventilation hood and separates at the rear end of the ventilation hood. According to the Coanda effect, the airflow will deflect downward to a certain extent, increasing the airflow velocity at the bottom of the radiator, thereby improving the heat dissipation performance of the generator. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of a ventilation cover structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the top surface structure of the ventilation cover of a ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram showing the positional relationship between the ventilation cover and the heat dissipation plate of a ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the central vortex of a ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of airflow simulation for a double-opening ventilation hood according to an embodiment of the present invention.

[0026] Figure 7 This is a simulation diagram of the airflow of the ventilation hood of a ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine according to an embodiment of the present invention.

[0027] In the diagram: 1. Blade 2. Gearbox 3. Exhaust vent 4. Radiator 5. Ventilation hood 6. Inclined transition section 7. Planar section 8. Rounded corner 9. Left front cover 10. Right front cover 11. Air outlet 12. Obtuse angle 13. Rear wall 14. Left cover 15. Right cover 16. Radiator panel 17. Angle α 18. Tail end of the planar section of the ventilation hood 19. Guide cavity 20. Separation point 21. High-temperature airflow 22. Central axis 23. Central vortex. Detailed Implementation

[0028] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0029] Example:

[0030] like Figure 1 The ventilation and heat dissipation structure shown includes a blade 1 and a gearbox 2 disposed behind the blade 1. The gearbox 2 is coaxially arranged with the blade shaft. Figure 2 As shown, the gearbox 2 has an exhaust vent 3 on its upper surface, which communicates with the interior of the gearbox 2. A radiator 4 is located on one side of the exhaust vent 3 on the upper surface of the gearbox 2, and a ventilation hood 5 covers the exhaust vent 3. Figure 3As shown, the ventilation hood 5 includes: a front end cover plate adjacent to the blade 1, a rear end cover plate away from the blade, and side plates connected to one side of the front end cover plate and one side of the rear end cover plate respectively. The front end cover plate is divided into a left front end cover plate 9 and a right front end cover plate 10, and an obtuse angle 12 is formed between the left front end cover plate 9 and the right front end cover plate 10 facing away from the blade 1.

[0031] The front cover, rear cover, side plates, and gearbox 2 together form a guide cavity 19. The guide cavity 19 has a rectifying function, collecting the high-temperature airflow 21 from the gearbox 2, reducing exhaust back pressure, and allowing for smoother airflow discharge, which is beneficial for heat dissipation of the gearbox 2's lubrication system. The rear cover includes an upper cover plate and a rear wall 13 connected to the upper cover plate. The upper cover plate includes a left cover plate 14 and a right cover plate 15 symmetrically arranged along the central axis 22. The left cover plate 14 and right cover plate 15 gradually descend from the central axis 22 to both sides, forming inclined surfaces. This ensures that the airflow flows close to the wall surface of the ventilation hood 5, preventing flow separation.

[0032] like Figure 4 As shown, the front cover includes an inclined transition section 6 and a flat section 7 disposed at one end of the inclined transition section 6. The other end of the inclined transition section 6 is connected to the upper surface of the gearbox 2. The angle α17 between the plane containing the inclined transition section 6 and the plane containing the upper surface of the gearbox 2 satisfies: 10°≤α≤60°. The radiator 4 includes a radiator panel 16 disposed perpendicular to the back of the gearbox 2. The distance X between the lower edge of the back plate of the ventilation shroud 5 and the radiator panel 16 satisfies: Where v is the wind speed at the outlet 11, ω is the rotor speed, h is the height difference between the side cover of the outlet 11 and the upper surface of the gearbox 2, β is the obtuse angle 12 formed between the left front cover 9 and the right front cover 10 facing away from the blade 1; C is a set coefficient, the value of which is related to the wind speed v and the rotor speed ω. When the rotor speed ω is higher and the wind speed v is greater, the value of C is smaller. The distance between the radiator 4 and the ventilation shroud 5 can prevent the radiator 4 from being affected by the wake area of ​​the air outlet of the ventilation shroud 5, thereby improving the heat dissipation performance of the generator. The inclined transition section 6 and streamlined structure at the front end of the ventilation shroud 5 allow the airflow to flow close to the wall and will not separate on the upper surface of the ventilation shroud 5. According to the Candareen effect, when the airflow is at the tail 18 of the plane section of the ventilation shroud, the airflow will be deflected downward to a certain extent, increasing the airflow speed at the bottom of the radiator 4, thereby improving the heat dissipation performance and improving the heat dissipation performance of the wind turbine. The streamlined characteristics of the ventilation shroud 5 minimize the wake area it generates. One end of the planar segment 7 is connected to the inclined transition segment 6, and the other end of the planar segment 7 is connected to one end of the rear cover plate. The connection between the inclined transition segment 6 and the planar segment 7 adopts a rounded corner streamlined transition. The other side of the front cover plate, the other side of the rear cover plate, and the upper surface of the gearbox 2 together form an air outlet 11.

[0033] Viewed from the back of gearbox 2 towards blade 1, when blade 1 rotates counterclockwise, the air outlet 11 is located on the right side of ventilation shroud 5; when blade 1 rotates clockwise, the air outlet 11 is located on the left side of ventilation shroud 5. The inclined transition section 6 and streamlined structure at the front end of ventilation shroud 5 allow the airflow to flow close to the wall without separation on the upper surface of ventilation shroud 5. According to the Candareen effect, when the airflow reaches the tail of the planar section 7 of ventilation shroud 5, the airflow will be deflected downwards to a certain extent, increasing the airflow velocity at the bottom of radiator 4, thereby improving heat dissipation performance and enhancing the heat dissipation performance of the wind turbine. The streamlined characteristics of ventilation shroud 5 minimize the wake area it generates.

[0034] like Figure 5 , Figure 6 and Figure 7 As shown, during the rotation of the wind turbine blade 1, tip vortex and central vortex 23 are generated. The rotation direction of the central vortex 23 is opposite to the rotation direction. The strong central vortex will change the flow field in front of the radiator 4. Taking the blade 1 rotating counterclockwise as an example, the strong central vortex will cause the high-temperature airflow discharged from the ventilation shroud 5 to rotate clockwise. If the air outlet 11 of the ventilation shroud 5 is located on the left side, the high-temperature airflow will directly hit the radiator 4 under the action of the central vortex 23, affecting the heat dissipation performance. However, if the air outlet 3 of the ventilation shroud 5 is located on the right side, the influence of the central vortex on the radiator 4 can be avoided.

[0035] The ventilation hood 5 has a single-sided opening. The guide cavity 19 between the ventilation hood 5 and the upper surface of the gearbox 2 has a rectifying effect, which gathers the high-temperature airflow from the gearbox 2, reduces the exhaust back pressure, and makes the airflow more smoothly discharged. The high-temperature airflow discharged from the air outlet 11 can avoid hitting the radiator behind. At the same time, with the help of the rotation characteristics of the central vortex, the high-temperature airflow will be further away from the radiator 4, ensuring the heat dissipation performance of the radiator 4. Meanwhile, the rotation of the wind turbine blades 1 will generate back airflow. The airflow separates at the separation point 20 at the exhaust port of the ventilation hood 5. After the airflow is separated, a low-pressure area will be formed at the air outlet 11 of the ventilation hood 5. This low-pressure area has a certain suction effect, which helps the high-temperature airflow inside the ventilation hood to be discharged smoothly, increases the exhaust flow, and improves the heat dissipation performance of the gearbox lubrication system.

[0036] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0037] Although this document frequently uses terms such as ventilation hood, central vortex, shroud, airflow cavity, and radiator, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine, comprising blades and a gearbox disposed behind the blades, characterized in that, The gearbox is coaxially arranged with the propeller shaft. The upper surface of the gearbox is provided with an exhaust port, which communicates with the interior of the gearbox. A radiator is provided on one side of the upper surface of the gearbox near the exhaust port. A ventilation hood is provided on the exhaust port. The ventilation hood includes: a front cover plate adjacent to the propeller blade, a rear cover plate away from the propeller blade, and side plates connected to one side of the front cover plate and one side of the rear cover plate respectively. The front cover plate, the rear cover plate, the side plates and the gearbox together form a flow guide cavity. The other side of the front cover plate, the other side of the rear cover plate and the upper surface of the gearbox together form an air outlet. Viewed from the back of the gearbox towards the propeller, when the propeller rotates counterclockwise, the air outlet is located on the right side of the ventilation hood; when the propeller rotates clockwise, the air outlet is located on the left side of the ventilation hood. The front end cover is divided into a left front end cover and a right front end cover, and the left front end cover and the right front end cover form an obtuse angle facing away from the blade.

2. The ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to claim 1, characterized in that, The front cover includes an inclined transition section and a flat section disposed at one end of the inclined transition section. The other end of the inclined transition section is connected to the upper surface of the gearbox. One end of the flat section is connected to the inclined transition section, and the other end of the flat section is connected to one end of the rear cover. The connection between the inclined transition section and the flat section adopts a rounded streamlined transition.

3. The ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to claim 2, characterized in that, The airflow guide cavity utilizes the Coanda effect to deflect the airflow downwards at the tail of the flat section of the ventilation hood, thereby increasing the airflow velocity at the bottom of the radiator.

4. The ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to claim 3, characterized in that, The rear end cover includes an upper cover and a rear wall connected to the upper cover, the upper cover including a left cover and a right cover symmetrically arranged along the central axis.

5. A ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to claim 4, characterized in that, The left and right cover plates gradually descend from the central axis to both sides, forming inclined surfaces.

6. A ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to any one of claims 4 or 5, characterized in that, The radiator includes a radiator panel disposed perpendicular to the back of the gearbox, and the distance X between the lower edge of the ventilation shroud back plate and the radiator panel satisfies: Where v is the air outlet wind speed, ω is the impeller speed, h is the height difference between the air outlet side cover and the upper surface of the gearbox, β is the obtuse angle formed between the left and right front cover plates facing away from the blades, and C is a set coefficient whose value is related to the wind speed v and the impeller speed ω. When the impeller speed ω is higher and the wind speed v is greater, the value of C is smaller.

7. A ventilation and heat dissipation structure for improving the heat dissipation performance of a wind turbine generator according to claim 6, characterized in that, The angle α between the plane containing the inclined transition section and the plane containing the upper surface of the gearbox satisfies: 10°≤α≤60°.

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