A cooling system, method and generator for a direct-cooled doubly-fed generator
By drawing air from outside the nacelle into the direct-cooled doubly-fed generator and utilizing multiple ventilation and heat dissipation mechanisms and aerodynamic design, the problem of low generator cooling efficiency has been solved, achieving more efficient heat dissipation and reduced costs.
Patent Information
- Application Number
- CN202610265760.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-05
- Publication Date
- 2026-07-03
Smart Images
Figure CN122339147A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of wind turbine cooling devices, specifically relating to a cooling system, method, and generator for a direct-cooled doubly-fed generator. Background Technology
[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.
[0003] Currently, doubly-fed induction generators (DFIGs) are the most widely used generators in wind turbine generator sets. Due to cost considerations, directly-cooled DFIGs are widely used. Directly-cooled DFIGs draw air from inside the nacelle and exhaust it directly outside through a duct. However, because the nacelle also houses cooling fans for gearboxes, converters, main control cabinets, and other components, the direct air intake creates negative pressure, affecting the cooling efficiency of the directly-cooled DFIG. Therefore, improving the cooling efficiency of directly-cooled DFIGs is a crucial problem that needs to be addressed.
[0004] Existing direct-cooled doubly-fed generators all have a cooler installed on top of the generator, with a cooling motor mounted on the cooler. The air inlet is located on the cooler, drawing air directly from inside the nacelle. Since the generator draws air directly from inside the nacelle, the cooling efficiency using a cooling fan is very low due to the negative pressure inside the nacelle. Current direct-cooled doubly-fed generator cooling solutions do not consider the characteristics of generator cooling from the perspective of the entire wind turbine generator set, resulting in increased generator temperature and failing to fundamentally solve the problem of low generator cooling efficiency. Summary of the Invention
[0005] To address the aforementioned issues, this invention provides a cooling system, method, and generator for a direct-cooled doubly-fed generator. By drawing air from outside the nacelle through a nacelle cover heat dissipation mechanism and a generator ventilation and heat dissipation mechanism, the problem of air competition with other components inside the nacelle and the presence of negative pressure within the nacelle are resolved. This ensures that the entire device will not experience excessively high temperatures, and reduces the overall production cost and operating noise of the equipment.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a cooling system for a directly cooled doubly-fed generator, comprising: the directly cooled doubly-fed generator being disposed inside a nacelle cover; the cooling system comprising a plurality of ventilation and heat dissipation mechanisms disposed within the wind turbine; the ventilation and heat dissipation mechanisms comprising a nacelle cover heat dissipation mechanism, a generator ventilation and heat dissipation mechanism, and an internal ventilation and heat dissipation mechanism for the wind turbine; the nacelle cover heat dissipation mechanism being connected to the generator ventilation and heat dissipation mechanism via the internal ventilation and heat dissipation mechanism for the wind turbine; The internal ventilation and heat dissipation mechanism of the wind turbine consists of an air outlet guide duct, an air outlet self-closing louver, a first air inlet guide duct, and a second air inlet guide duct. One end of each of the air outlet guide duct, the first air inlet guide duct, and the second air inlet guide duct is connected to the generator ventilation and heat dissipation mechanism, and the other end is connected to the nacelle cover heat dissipation mechanism. The air outlet guide duct is provided with an air outlet self-closing louver at its air outlet.
[0007] As a further implementation, the generator ventilation and heat dissipation mechanism includes an air guide duct support mechanism and a generator body air guide duct. The generator body air guide duct is disposed above the generator body and communicates with the cavity of the generator body. A generator rotor is disposed in the generator body. An air guide groove is disposed around the generator rotor along the axial direction. The two sides of the air guide groove have a set height difference. Fan wheels are disposed at both ends of the generator rotor. The air guide duct support mechanism is disposed between the generator body air guide duct and the generator body for fixing the generator body air guide duct. The generator air outlet at the end of the generator body air guide duct communicates with the air outlet air guide duct.
[0008] As a further implementation, the generator ventilation and heat dissipation mechanism also includes a first air inlet and a second air inlet at the bottom of the generator body. The first air inlet is connected to the first air intake duct, and the second air inlet is connected to the second air intake duct, for supplying air into the cavity of the generator body.
[0009] As a further implementation, a differential pressure sensor is also provided on the generator body to monitor the pressure in the generator body cavity.
[0010] As a further implementation, the nacelle cover heat dissipation mechanism includes a first motorized louver and a second motorized louver disposed at the bottom of the nacelle cover. The first motorized louver is provided with a first primary filter cotton, and the second motorized louver is provided with a second primary filter cotton, for filtering the air entering the generator.
[0011] As a further implementation, the first air inlet duct is connected to the first motorized louver via a primary filter cotton support mechanism; the second air inlet duct is connected to the second motorized louver via a secondary filter cotton support mechanism.
[0012] As a further implementation, the first-stage filter cotton support mechanism is provided with a first-stage filter cotton; the second-stage filter cotton support mechanism is provided with a second-stage filter cotton, which is used to perform secondary filtration on the air entering the generator.
[0013] As a further implementation, the nacelle cover heat dissipation mechanism also includes an exhaust vent located at the top of the bottom of the nacelle cover. The exhaust vent of the exhaust duct is connected to the exhaust vent through an exhaust vent self-closing louver to prevent foreign objects from entering the cavity of the generator body from the exhaust duct.
[0014] Secondly, the present invention also provides a cooling method for a cooling system of a directly-cooled doubly-fed generator, specifically including the following steps: S1. When the generator is generating electricity, the first and second electric louvers at the bottom of the nacelle cover are opened. The cooling air outside the generator nacelle is filtered by two primary filter cottons and two secondary filter cottons under the action of the generator rotor and then enters the generator body for heat exchange. S2. After heat exchange is completed, the heated air guide duct and fan wheel carry away the heat generated by the generator, and the heated air is discharged outside the nacelle through the generator body air guide duct and the air outlet air guide duct; the air outlet self-closing louvers open automatically under the blowing of the airflow in the generator body air guide duct.
[0015] Thirdly, the present invention also provides a generator equipped with the cooling system described above for a direct-cooled doubly-fed generator.
[0016] Compared with the prior art, the advantages and positive effects of this invention are: This invention, based on the mechanism of ventilation and heat dissipation and considering aerodynamics, draws air directly from outside the nacelle. The temperature of the cooling air entering the generator is about 10K lower than that of the nacelle, which can more effectively remove the heat generated by the generator. The generator draws air directly from outside the nacelle through the nacelle cover heat dissipation mechanism and the generator ventilation and heat dissipation mechanism, eliminating the problem of competing for air with other components inside the nacelle and avoiding airflow conflicts and turbulent air paths. The generator draws air directly from outside, eliminating the problem of negative pressure and eliminating the use of a generator cooling motor. This ensures that the entire device will not experience excessive height during transportation, while also reducing the overall production cost of the equipment and the operating noise of the wind turbine generator set.
[0017] This invention employs electrically operated louvers at the bottom of the engine compartment cover. These louvers close when the generator is off and open when the generator is running. While the generator is still hot, the louvers remain open until the temperature drops to the target value, at which point they close. The cooling air is filtered by primary and secondary filters. The primary filter is designed to be easy to clean, actively removing particles and dust from the engine compartment using airflow, thus eliminating the need for primary filter replacement. A differential pressure sensor monitors the pressure difference between the inside and outside of the generator in real time, providing an early warning for the replacement of the secondary filter. Attached Figure Description
[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0019] Figure 1 This is a schematic diagram of the generator ventilation and heat dissipation mechanism at the bottom of the wind turbine nacelle cover of the present invention; Figure 2 This is a schematic diagram of the generator ventilation and heat dissipation mechanism of the present invention; Figure 3 This is a schematic diagram of the ventilation and heat dissipation mechanism at the bottom of the generator of the present invention; Figure 4 This is a schematic diagram of the internal ventilation and heat dissipation mechanism of the wind turbine generator of the present invention.
[0020] In the diagram: 1. Nacelle hood heat dissipation mechanism; 11. First motorized louver; 12. First primary filter cotton; 13. Second motorized louver; 14. Second primary filter cotton; 2. Generator ventilation and heat dissipation mechanism; 21. Generator body; 22. Generator rotor; 23. Air duct support mechanism; 24. Generator body air duct; 25. Air outlet; 26. Differential pressure sensor; 27. First air inlet; 28. Second air inlet; 29. Fan wheel; 3. Wind turbine internal ventilation and heat dissipation mechanism; 31. Air outlet air duct; 32. Air outlet self-closing louver; 33. First primary filter cotton support mechanism; 34. First primary filter cotton; 35. First air inlet air duct; 36. Second primary filter cotton support mechanism; 37. Second primary filter cotton; 38. Second air inlet air duct; 39. Nacelle hood. Detailed Implementation
[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. In existing technologies, the air intake and exhaust methods of direct-cooled doubly-fed wind turbine generators typically involve drawing air from inside the nacelle and introducing it into the generator through a cooler on top. The air temperature inside the nacelle is approximately 10K higher than the ambient temperature, resulting in higher air temperatures entering the generator and lower cooling efficiency. Furthermore, the negative pressure created by drawing air from inside the nacelle necessitates the use of a cooling motor, increasing generator costs. The presence of numerous heat dissipation devices within the nacelle leads to airflow conflicts and turbulent airflow paths, affecting the heat dissipation of other components. Additionally, the generator's cooler and cooling motor increase its height, requiring the nacelle cover design to account for this height, which impacts the overall transport of the unit and raises concerns about exceeding transport limits. To address these issues, the technical solution of this invention will be described below with reference to the accompanying drawings.
[0023] Example 1 This embodiment provides a cooling system for a directly-cooled doubly-fed induction generator. Based on the mechanism of ventilation and heat dissipation, and considering aerodynamics and fluid dynamics, it directly draws air from outside the nacelle. External air enters the generator through the internal ventilation and heat dissipation mechanism of the wind turbine, and the hot air, after heat exchange, is exhausted outside the nacelle. This improves the generator's heat dissipation efficiency and also enhances the heat dissipation efficiency of other components within the nacelle, such as… Figures 1-4 As shown, the system includes: the directly cooled doubly fed generator is installed inside the nacelle cover 39; the cooling system includes multiple ventilation and heat dissipation mechanisms installed in the wind turbine; the ventilation and heat dissipation mechanism includes a nacelle cover heat dissipation mechanism 1, a generator ventilation and heat dissipation mechanism 2, and a wind turbine internal ventilation and heat dissipation mechanism 3; the nacelle cover heat dissipation mechanism 1 is connected to the generator ventilation and heat dissipation mechanism 2 through the wind turbine internal ventilation and heat dissipation mechanism 3. The internal ventilation and heat dissipation mechanism 3 of the wind turbine consists of an air outlet guide duct 31, an air outlet self-closing louver 32, a first air inlet guide duct 35, and a second air inlet guide duct 38. One end of each of the air outlet guide duct 31, the first air inlet guide duct 35, and the second air inlet guide duct 38 is connected to the generator ventilation and heat dissipation mechanism 2, and the other end is connected to the nacelle cover heat dissipation mechanism 1. The air outlet self-closing louver 32 is provided at the air outlet 25 of the air outlet guide duct 31. By directly drawing air from the outside of the nacelle through the nacelle cover heat dissipation mechanism 1 and the generator ventilation and heat dissipation mechanism 2, the temperature of the air entering the generator is reduced, and the air pressure entering the generator is reduced. In addition, since the air is directly drawn from the outside of the nacelle, the cooling motor on the top of the generator is eliminated, which can reduce the height of the generator, reduce the weight of the generator, reduce the cost of the generator, and thus reduce the height of the nacelle cover 39, avoiding the problem of the wind turbine being transported at excessive height.
[0024] As a further implementation, the generator ventilation and heat dissipation mechanism 2 includes an air guide tube support mechanism 23 and a generator body air guide tube 24. The generator body air guide tube 24 is disposed above the generator body 21 and communicates with the cavity of the generator body 21. A generator rotor 22 is disposed in the generator body 21. An air guide groove is disposed around the generator rotor 22 along the axial direction. The two sides of the air guide groove have a set height difference. Fan wheels 29 are disposed at both ends of the generator rotor 22. The air guide tube support mechanism 23 is disposed between the generator body air guide tube 24 and the generator body 21 for fixing the generator body air guide tube 24. The air outlet 25 at the end of the generator body air guide tube 24 communicates with the air outlet air guide tube 31.
[0025] As a further implementation, the generator ventilation and heat dissipation mechanism 2 also includes a first air inlet 27 and a second air inlet 28 provided at the bottom of the generator body 21. The first air inlet 27 is connected to the first air intake duct 35, and the second air inlet 28 is connected to the second air intake duct, for supplying air into the cavity of the generator body 21.
[0026] As a further implementation, a differential pressure sensor 26 is also provided on the generator body 21 to monitor the pressure in the cavity of the generator body 21; by measuring the pressure difference between the air inside and outside the generator, the sensor can remind the secondary filter cotton to be replaced, thus achieving early warning.
[0027] As a further implementation, the nacelle cover heat dissipation mechanism 1 includes a first motorized louver 11 and a second motorized louver 13 disposed at the bottom of the nacelle cover 39. The first motorized louver 11 is provided with a first primary filter cotton 12, and the second motorized louver 13 is provided with a second primary filter cotton 14, which are used to perform primary filtration of the air entering the generator, and to perform secondary filtration in combination with the first primary filter cotton 34 and the second primary filter cotton 37, to ensure the cleanliness of the cooling air entering the generator and to prevent debris from entering the generator body 21 and damaging the precision components. The first motorized louver 11 and the second motorized louver 13 are disposed at the bottom of the nacelle cover 39, which can effectively prevent rain and snow from entering the generator. The motorized louvers disposed on the nacelle cover 39 are closed when the unit is stopped and opened when the unit is running.
[0028] As a further implementation, the first air inlet duct 35 is connected to the first motorized louver 11 via the first primary filter cotton support mechanism 33; the second air inlet duct 38 is connected to the second motorized louver 13 via the second primary filter cotton support mechanism 36.
[0029] As a further implementation, the primary filter cotton support mechanism 33 is provided with a primary filter cotton 34; the secondary filter cotton support mechanism 36 is provided with a secondary filter cotton 37, which is used to perform secondary filtration on the air entering the generator.
[0030] As a further implementation, the nacelle cover heat dissipation mechanism 1 also includes an exhaust vent located at the top of the bottom of the nacelle cover 39. The exhaust vent 25 of the exhaust vent guide tube 31 is connected to the exhaust vent through an exhaust vent self-closing louver 32, which can automatically close when there is no wind to prevent foreign objects such as flying insects from flowing back into the generator.
[0031] This invention considers the cooling scheme of a direct-cooled doubly-fed generator from the perspective of the entire wind turbine generator set. It takes into account the nacelle wind pressure, heat dissipation efficiency, and intake air temperature. It considers the cooling of various components of the wind turbine generator set, the intake position of the direct-cooled generator, the air flow path, and the air resistance. The direct-cooled generator draws air directly from outside the nacelle, which not only improves the cooling efficiency of the direct-cooled generator itself, but also improves the cooling efficiency of other large components in the nacelle, thereby improving the operational reliability of the wind turbine generator set.
[0032] Example 2 This embodiment provides a cooling method for a cooling system of a directly-cooled doubly-fed generator, specifically including the following steps: S1. When the generator is generating electricity, the first electric louver 11 and the second electric louver 13 at the bottom of the nacelle cover 39 are opened. The cooling air outside the generator nacelle is filtered by two primary filter cottons and two secondary filter cottons under the action of the generator rotor 22 and then enters the generator body 21 for heat exchange. The air forms an airflow under the action of the air guide duct and the fan wheel 29 as the generator rotor 22 rotates. The flow of cooling air can be realized without the need for an additional airflow drive device. S2. After heat exchange is completed, the heated air, under the action of the air guide duct and fan wheel 29, carries away the heat generated by the generator. The heated air is then discharged outside the nacelle through the generator body air guide duct 24 and the air outlet air guide duct 31. The self-closing louver 32 of the air outlet automatically opens under the blowing of the airflow in the generator body air guide duct 24. In this invention, hot air is discharged from the nacelle through the generator base, generator rotor 22, air outlet 25, air guide duct, and self-closing louver. The airflow required for generator heat dissipation does not pass through the interior of the nacelle, which is beneficial for the heat dissipation of other heat dissipation equipment in the nacelle and improves the cooling efficiency of various equipment in the wind turbine generator nacelle.
[0033] Example 3 This embodiment provides a generator equipped with the cooling system described above for a direct-cooled doubly-fed generator.
[0034] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.
Claims
1. A cooling system for a directly-cooled doubly-fed generator, characterized in that, include: The directly-cooled doubly-fed generator is installed inside the nacelle cover. The cooling system includes multiple ventilation and heat dissipation mechanisms installed in the wind turbine. The ventilation and heat dissipation mechanism includes a nacelle cover heat dissipation mechanism, a generator ventilation and heat dissipation mechanism, and an internal ventilation and heat dissipation mechanism for the wind turbine. The nacelle cover heat dissipation mechanism is connected to the generator ventilation and heat dissipation mechanism through the internal ventilation and heat dissipation mechanism for the wind turbine. The internal ventilation and heat dissipation mechanism of the wind turbine consists of an air outlet guide duct, an air outlet self-closing louver, a first air inlet guide duct, and a second air inlet guide duct. One end of each of the air outlet guide duct, the first air inlet guide duct, and the second air inlet guide duct is connected to the generator ventilation and heat dissipation mechanism, and the other end is connected to the nacelle cover heat dissipation mechanism. The air outlet guide duct is provided with an air outlet self-closing louver at its air outlet.
2. The cooling system for a direct-cooled doubly-fed generator as described in claim 1, characterized in that, The generator ventilation and heat dissipation mechanism includes an air guide duct support mechanism and a generator body air guide duct. The generator body air guide duct is located above the generator body and communicates with the cavity of the generator body. A generator rotor is provided in the generator body. An air guide groove is provided around the generator rotor along the axial direction. The two sides of the air guide groove have a set height difference. Fan wheels are provided at both ends of the generator rotor. The air guide duct support mechanism is located between the generator body air guide duct and the generator body and is used to fix the generator body air guide duct. The generator air outlet at the end of the generator body air guide duct is connected to the air outlet air guide duct.
3. The cooling system for a direct-cooled doubly-fed generator as described in claim 2, characterized in that, The generator ventilation and heat dissipation mechanism also includes a first air inlet and a second air inlet located at the bottom of the generator body. The first air inlet is connected to the first air intake duct, and the second air inlet is connected to the second air intake duct, for supplying air into the cavity of the generator body.
4. The cooling system for a direct-cooled doubly-fed generator as described in claim 1, characterized in that, The generator body is also equipped with a differential pressure sensor to monitor the pressure in the generator body cavity.
5. The cooling system for a direct-cooled doubly-fed generator as described in claim 1, characterized in that, The engine hood cooling mechanism includes a first motorized louver and a second motorized louver located at the bottom of the engine hood. The first motorized louver is provided with a first primary filter cotton, and the second motorized louver is provided with a second primary filter cotton, for filtering the air entering the generator.
6. The cooling system for a direct-cooled doubly-fed generator as described in claim 5, characterized in that, The first air inlet duct is connected to the first motorized louver via a primary filter cotton support mechanism; the second air inlet duct is connected to the second motorized louver via a secondary filter cotton support mechanism.
7. The cooling system for a direct-cooled doubly-fed generator as described in claim 6, characterized in that, The first-stage filter cotton support mechanism is equipped with a first-stage filter cotton; the second-stage filter cotton support mechanism is equipped with a second-stage filter cotton, which is used to perform secondary filtration on the air entering the generator.
8. The cooling system for a direct-cooled doubly-fed generator as described in claim 5, characterized in that, The nacelle cover heat dissipation mechanism also includes an exhaust vent located at the top of the bottom of the nacelle cover. The exhaust vent of the exhaust duct is connected to the exhaust vent through an exhaust vent self-closing louver to prevent foreign objects from entering the cavity of the generator body from the exhaust duct.
9. A cooling method for a cooling system of a direct-cooled doubly-fed generator as described in any one of claims 1-8, characterized in that, Specifically, the following steps are included: S1. When the generator is generating electricity, the first and second electric louvers at the bottom of the nacelle cover are opened. The cooling air outside the generator nacelle is filtered by two primary filter cottons and two secondary filter cottons under the action of the generator rotor and then enters the generator body for heat exchange. S2. After heat exchange is completed, the heated air guide duct and fan wheel carry away the heat generated by the generator, and the heated air is discharged outside the nacelle through the generator body air guide duct and the air outlet air guide duct; the air outlet self-closing louvers open automatically under the blowing of the airflow in the generator body air guide duct.
10. A generator, characterized in that, The generator is equipped with a cooling system as described in any one of claims 1-8.