Air gap bypass-flow type ventilation and cooling method for long-core low-speed wind turbine generator

Abstract

The present invention belongs to the technical field of wind turbine generators. Disclosed is an air gap bypass-flow type ventilation and cooling method for a long-core low-speed wind turbine generator, the method comprising the following steps: S1, providing a stator base having a ventilation cavity on the inner diameter side of a stator core, and providing an air gap between the stator and a rotor; S2, introducing cooling air into a cooling air cavity of a cooling air region of the stator base by means of a cooling fan; and S3, the cooling air successively passing through the cooling air cavity and a stator core ventilation duct, then entering the air gap, and then entering a hot air cavity of a hot air region of the stator base via the stator core ventilation duct, so as to cool the stator core and a stator coil embedded in a slot of the stator core. In the present invention, by means of the air gap bypass-flow type ventilation and cooling mode, not only the uniformity of circumferential cooling air volumes can be greatly improved, but also the distribution of speeds of wind passing through the stator core ventilation duct in the axial direction is more uniform than that of traditional structures, thus greatly improving the cooling effect of generators.

Description

A method for air gap-flow ventilation cooling of a long-core low-speed wind turbine Technical Field

[0001] This invention relates to the field of wind turbine technology, and in particular to a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine. Background Technology

[0002] Low-speed permanent magnet wind turbines operate at low speeds, only around 10 r / min. The pressure generated by the rotating parts is only a few Pascals, which is insufficient to drive airflow within the motor to remove operating losses. Therefore, specialized fans are typically used as the primary pressure source for airflow.

[0003] For larger capacity permanent magnet low-speed wind turbines with longer iron cores, radial ventilation is used. After passing through the stator, the cooling air enters the air gap and diffuses to both ends of the iron core. Finally, it passes through the stator winding ends and ventilation ducts. Due to the long iron core, the ventilation path for the parts of the stator that are directly cooled is long. In addition, due to structural limitations, it is generally impossible to evenly arrange the fans around the frame. As a result, the temperature distribution around the stator coils and iron core is uneven, with a circumferential temperature difference of up to 30K-40K. This makes it difficult to further increase the electromagnetic load and affects the economic efficiency of the motor.

[0004] Chinese patent document CN110429747B, published on November 20, 2020, discloses a method for reducing the circumferential temperature difference between a motor coil and its core, comprising the following steps:

[0005] a. Install a device to reduce the circumferential temperature difference between the coil and core of a large-diameter motor onto the wind turbine generator;

[0006] b. Install an inclined baffle at the outlet of the air inlet pipe. The angle between the inclined baffle and the first vertical plate is 30-60°. Install an air volume regulating plate on the air inlet hole. The air volume regulating plate is hinged to the first circumferential ring plate. The circumferential air resistance is adjusted by the air volume regulating plate.

[0007] c. Within a circumferentially symmetrical unit, minimize the airflow area at the near-fan end close to the fan axis and maximize the airflow area at the far-fan end far from the fan axis.

[0008] The device for reducing the circumferential temperature difference between the large-diameter motor coil and the core includes a rotor frame, a rotor core mounted on the rotor frame, and multiple rotor magnets arranged axially along the rotor core. It also includes multiple stator core sections, a first core pressure plate, a second core pressure plate, and a tensioning screw. Each stator core section is composed of stacked silicon steel sheets, with slots for placing the stator coils. A stator channel steel connects any two adjacent stator core sections, forming a stator ventilation groove for cooling medium flow. The tensioning screw passes through the multiple stator core sections, with one end fixedly connected to the first core pressure plate and the other end fixedly connected to the second core pressure plate. An air gap is provided between the rotor magnets and the stator core sections. A first circumferential ring plate is fixedly connected to each of the multiple stator core sections. One end of the first circumferential ring plate is fixedly connected to the first core pressure plate, and the other end of the first circumferential ring plate is fixedly connected to the second core pressure plate. At least three axial vertical plates are fixedly connected to the inner wall of the first circumferential ring plate. An air inlet cavity and an air outlet cavity are formed between the first circumferential ring plate, the stator core section, and two adjacent axial vertical plates. The air inlet cavity and the air outlet cavity are arranged at intervals. Multiple air inlet holes and multiple air outlet holes are opened on the first circumferential ring plate. The air inlet holes are connected to the corresponding air inlet cavity, and the air outlet holes are connected to the corresponding air outlet cavity. A first vertical plate and a second vertical plate are fixedly connected to the outer wall of the first circumferential ring plate. A second circumferential ring plate is fixedly connected between the first vertical plate and the second vertical plate. A slanted wind baffle is connected to the first vertical plate through multiple connecting plates. An air outlet pipe communicating with the air outlet cavity is connected to the second circumferential ring plate, and an air inlet pipe communicating with the air inlet cavity is connected to the first vertical plate.

[0009] The method disclosed in this patent document for reducing the circumferential temperature difference between the motor coil and the iron core is simple and flexible to operate. However, the structure and installation are complex, making it inconvenient to implement, and the airflow distribution in the stator is not uniform, affecting the cooling effect. Summary of the Invention

[0010] In order to overcome the shortcomings of the prior art, this invention provides a method for air gap flow-through ventilation cooling of a long-core low-speed wind turbine. This invention, through air gap flow-through ventilation cooling, can not only significantly improve the uniformity of circumferential cooling airflow, but also achieve a more uniform axial distribution of wind speed through the stator core ventilation channel compared to traditional structures, which is beneficial to significantly improve the motor cooling effect.

[0011] This invention is achieved through the following technical solution:

[0012] A method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0013] S1. A stator frame with a ventilation cavity is provided on the inner diameter side of the stator core, and an air gap is provided between the stator and the rotor.

[0014] S2. Cooling air is introduced into the cooling air cavity of the cold air zone of the stator frame by a cooling fan;

[0015] S3. Cooling air enters the air gap sequentially through the cold air cavity and the stator core ventilation channel, and then enters the hot air cavity of the hot air zone of the stator frame through the stator core ventilation channel to cool the stator core and the stator coils embedded in the stator core slots.

[0016] In S1, the stator includes a core pressure plate, a tensioning screw, a stator coil, a core, and a stator frame. The core is divided into multiple segments, and stator core slots are provided on the core. Ventilation channel steel is provided between any two adjacent core segments. The tensioning screw passes through multiple core segments and is fixedly connected to the core pressure plate.

[0017] The stator base includes a first ring plate, a conical cylinder, a second ring plate, stiffeners, and a cylindrical cylinder. There are multiple stiffeners. The first ring plate, the conical cylinder, the second ring plate, the cylindrical cylinder, and the inner diameter of the core form an annular space. The stiffeners divide the annular space into several uniformly distributed cold air cavities and hot air cavities.

[0018] The cold air chamber and the hot air chamber are distributed at intervals along the circumference of the iron core.

[0019] In S1, the rotor includes a rotor base and a magnet. The inner diameter surface of the magnet is provided with a heat insulation layer, and the outer diameter side of the magnet is provided with a heat-conducting layer between it and the rotor base.

[0020] In S3, the stator core ventilation duct is formed by ventilation channel steel, stator coil and core.

[0021] In S3, the stator coil is embedded and fixed in the stator core slot by the slot bottom pad, interlayer pad, wedge pad and slot wedge.

[0022] The outer diameter of the stator core is 10-15 mm larger than the outer diameter of the slot wedge distribution circle.

[0023] The insulation layer is made of stainless steel or plastic.

[0024] The thermally conductive layer is thermally conductive silicone.

[0025] The beneficial effects of this invention are mainly reflected in the following aspects:

[0026] 1. Compared with the prior art, the present invention can significantly improve the uniformity of circumferential cooling airflow through the air gap ventilation cooling method. At the same time, the axial distribution of the wind speed through the stator core ventilation channel is more uniform than that of the traditional structure, which is conducive to significantly improving the motor cooling effect.

[0027] 2. This invention employs a specific air gap bypass method, which significantly reduces ventilation resistance compared to the traditional method of sending cooling air in through the air gaps at both ends and cooling it through the stator ventilation groove. This makes it easier to select a cooling fan. The structure is simple to install and easy to implement.

[0028] 3. In this invention, the outer diameter of the stator core is 10-15mm larger than the outer diameter of the slot wedge distribution circle, which allows the cooling air to flow circumferentially at each stator core ventilation channel, greatly reducing the resistance to the circumferential flow of cooling air. At the same time, it reduces the possibility of the air that has already exchanged heat with the stator core and coils and heated up exchanging heat with the magnets, thereby reducing its heating effect on the magnets.

[0029] 4. The present invention provides a heat insulation layer on the inner diameter surface of the magnet. The heat insulation layer is made of stainless steel or plastic, which reduces the heat exchange between the magnet and the cooling air in the air gap. This prevents the magnet from being heated by air at a higher temperature, which would lead to a decrease in the performance of the magnet or even demagnetization.

[0030] 5. In this invention, a heat-conducting layer is provided between the outer diameter side of the magnet and the rotor frame. The heat-conducting layer is thermally conductive silicone, which further enhances the heat exchange with the rotor frame. The eddy current loss caused by stator harmonics to the magnet is transferred to the rotor frame through the magnet and the high thermal conductivity material, and then carried away by the heat exchange between the outer surface of the rotor and the atmosphere, thereby ensuring the performance of the magnet. Attached Figure Description

[0031] The present invention will now be further described in detail with reference to the accompanying drawings and specific embodiments:

[0032] Figure 1 is a longitudinal sectional view of the wind turbine of the present invention;

[0033] Figure 2 is the AA view of Figure 1;

[0034] Figure 3 is an enlarged view of point A in Figure 2;

[0035] Figure 4 is an enlarged view of point B in Figure 2;

[0036] The markings in the diagram are: 1. Stator, 2. Core, 3. Stator frame, 4. Air gap, 5. Cold air zone, 6. Cold air cavity, 7. Stator core ventilation duct, 8. Hot air zone, 9. Hot air cavity, 10. Stator core slot, 11. Stator coil, 12. Core pressure plate, 13. Tensioning screw, 14. Ventilation channel steel, 15. First ring plate, 16. Conical cylinder, 17. Second ring plate, 18. Rib plate, 19. Cylinder, 20. Rotor frame, 21. Magnet, 22. Insulation layer, 23. Heat-conducting layer, 24. Slot bottom pad, 25. Interlayer pad, 26. Wedge pad, 27. Slot wedge. Embodiments of the present invention

[0037] Example 1

[0038] Referring to Figures 1 and 2, a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0039] S1. A stator frame 3 with a ventilation cavity is provided on the inner diameter side of the core 2 of the stator 1, and an air gap 4 is provided between the stator 1 and the rotor.

[0040] S2. Cooling air is introduced into the cooling air cavity 6 of the cooling air zone 5 of the stator frame 3 by a cooling fan;

[0041] S3. Cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7 to cool the stator core 2 and the stator coil 11 embedded in the stator core slot 10.

[0042] This embodiment is the most basic implementation method. Compared with the prior art, the air gap flow ventilation cooling method can not only greatly improve the uniformity of circumferential cooling air volume, but also the wind speed distribution in the axial direction of the stator core ventilation channel 7 is more uniform than the traditional structure, which is conducive to greatly improving the motor cooling effect.

[0043] Example 2

[0044] Referring to Figures 1 and 2, a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0045] S1. A stator frame 3 with a ventilation cavity is provided on the inner diameter side of the core 2 of the stator 1, and an air gap 4 is provided between the stator 1 and the rotor.

[0046] S2. Cooling air is introduced into the cooling air cavity 6 of the cooling air zone 5 of the stator frame 3 by a cooling fan;

[0047] S3. Cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7 to cool the stator core 2 and the stator coil 11 embedded in the stator core slot 10.

[0048] Preferably, in S1, the stator 1 includes a core pressure plate 12, a tensioning screw 13, a stator coil 11, a core 2, and a stator frame 3. The core 2 is multi-segmented, and a stator core slot 10 is provided on the core 2. A ventilation channel steel 14 is provided between any two adjacent core segments 2. The tensioning screw 13 passes through the multiple core segments 2 and is fixedly connected to the core pressure plate 12.

[0049] The stator base 3 includes a first ring plate 15, a cone cylinder 16, a second ring plate 17, a stiffener 18, and a cylinder 19. There are multiple stiffeners 18. The first ring plate 15, the cone cylinder 16, the second ring plate 17, the cylinder 19, and the inner diameter of the core 2 form an annular space. The stiffeners 18 divide the annular space into several uniformly distributed cold air cavities 6 and hot air cavities 9.

[0050] This embodiment is a preferred implementation method, which adopts a specific air gap bypass method. Compared with the traditional method of sending cooling air in through the air gaps at both ends and cooling through the stator ventilation groove, the ventilation resistance is significantly reduced, which is beneficial for the selection of cooling fans; the structure is simple to install and easy to implement.

[0051] Example 3

[0052] Referring to Figures 1-4, a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0053] S1. A stator frame 3 with a ventilation cavity is provided on the inner diameter side of the core 2 of the stator 1, and an air gap 4 is provided between the stator 1 and the rotor.

[0054] S2. Cooling air is introduced into the cooling air cavity 6 of the cooling air zone 5 of the stator frame 3 by a cooling fan;

[0055] S3. Cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7 to cool the stator core 2 and the stator coil 11 embedded in the stator core slot 10.

[0056] In S1, the stator 1 includes a core pressure plate 12, a tensioning screw 13, a stator coil 11, a core 2, and a stator frame 3. The core 2 is multi-segmented, and a stator core slot 10 is provided on the core 2. A ventilation channel steel 14 is provided between any two adjacent core segments 2. The tensioning screw 13 passes through the multiple core segments 2 and is fixedly connected to the core pressure plate 12.

[0057] The stator base 3 includes a first ring plate 15, a cone cylinder 16, a second ring plate 17, a stiffener 18, and a cylinder 19. There are multiple stiffeners 18. The first ring plate 15, the cone cylinder 16, the second ring plate 17, the cylinder 19, and the inner diameter of the core 2 form an annular space. The stiffeners 18 divide the annular space into several uniformly distributed cold air cavities 6 and hot air cavities 9.

[0058] The cold air chamber 6 and the hot air chamber 9 are distributed at intervals along the circumference of the iron core 2.

[0059] In a further preferred embodiment, in S1, the rotor includes a rotor base 20 and a magnet 21. A heat insulation layer 22 is provided on the inner diameter surface of the magnet 21, and a heat-conducting layer 23 is provided between the outer diameter side of the magnet 21 and the rotor base 20.

[0060] In S3, the stator core ventilation duct 7 is formed by the ventilation channel steel 14, the stator coil 11 and the core 2.

[0061] In S3, the stator coil 11 is embedded and fixed in the stator core slot 10 by the slot bottom pad 24, the interlayer pad 25, the wedge pad 26 and the slot wedge 27.

[0062] The outer diameter of the core 2 of the stator 1 is 10 mm larger than the outer diameter of the distribution circle of the slot wedge 27.

[0063] This embodiment is another preferred implementation. The outer diameter of the stator core 2 is larger than the outer diameter of the distribution circle of the slot wedge 27, so that the cooling air can flow circumferentially at each stator core ventilation channel 7, which greatly reduces the resistance of the circumferential flow of cooling air. At the same time, it reduces the possibility of the air that has been heated by heat exchange with the stator core and coils exchanging heat with the magnet 21, thereby reducing its heating effect on the magnet 21.

[0064] Example 4

[0065] Referring to Figures 1-4, a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0066] S1. A stator frame 3 with a ventilation cavity is provided on the inner diameter side of the core 2 of the stator 1, and an air gap 4 is provided between the stator 1 and the rotor.

[0067] S2. Cooling air is introduced into the cooling air cavity 6 of the cooling air zone 5 of the stator frame 3 by a cooling fan;

[0068] S3. Cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7 to cool the stator core 2 and the stator coil 11 embedded in the stator core slot 10.

[0069] In S1, the stator 1 includes a core pressure plate 12, a tensioning screw 13, a stator coil 11, a core 2, and a stator frame 3. The core 2 is multi-segmented, and a stator core slot 10 is provided on the core 2. A ventilation channel steel 14 is provided between any two adjacent core segments 2. The tensioning screw 13 passes through the multiple core segments 2 and is fixedly connected to the core pressure plate 12.

[0070] The stator base 3 includes a first ring plate 15, a cone cylinder 16, a second ring plate 17, a stiffener 18, and a cylinder 19. There are multiple stiffeners 18. The first ring plate 15, the cone cylinder 16, the second ring plate 17, the cylinder 19, and the inner diameter of the core 2 form an annular space. The stiffeners 18 divide the annular space into several uniformly distributed cold air cavities 6 and hot air cavities 9.

[0071] The cold air chamber 6 and the hot air chamber 9 are distributed at intervals along the circumference of the iron core 2.

[0072] In S1, the rotor includes a rotor base 20 and a magnet 21. A heat insulation layer 22 is provided on the inner diameter surface of the magnet 21, and a heat-conducting layer 23 is provided between the outer diameter side of the magnet 21 and the rotor base 20.

[0073] In S3, the stator core ventilation duct 7 is formed by the ventilation channel steel 14, the stator coil 11 and the core 2.

[0074] In S3, the stator coil 11 is embedded and fixed in the stator core slot 10 by the slot bottom pad 24, the interlayer pad 25, the wedge pad 26 and the slot wedge 27.

[0075] The outer diameter of the core 2 of the stator 1 is 12 mm larger than the outer diameter of the distribution circle of the slot wedge 27.

[0076] The heat insulation layer 22 is made of stainless steel.

[0077] This embodiment is another preferred implementation. By providing a heat insulation layer 22 on the inner diameter surface of the magnet 21, the heat insulation layer 22 is made of stainless steel, which can reduce the heat exchange between the magnet 21 and the cooling air in the air gap 4, and prevent the magnet 21 from being heated by air at a higher temperature, which would lead to a decrease in the performance of the magnet 21 or even demagnetization.

[0078] Example 5

[0079] Referring to Figures 1-4, a method for air gap-flow ventilation cooling of a long-core low-speed wind turbine includes the following steps:

[0080] S1. A stator frame 3 with a ventilation cavity is provided on the inner diameter side of the core 2 of the stator 1, and an air gap 4 is provided between the stator 1 and the rotor.

[0081] S2. Cooling air is introduced into the cooling air cavity 6 of the cooling air zone 5 of the stator frame 3 by a cooling fan;

[0082] S3. Cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7 to cool the stator core 2 and the stator coil 11 embedded in the stator core slot 10.

[0083] In S1, the stator 1 includes a core pressure plate 12, a tensioning screw 13, a stator coil 11, a core 2, and a stator frame 3. The core 2 is multi-segmented, and a stator core slot 10 is provided on the core 2. A ventilation channel steel 14 is provided between any two adjacent core segments 2. The tensioning screw 13 passes through the multiple core segments 2 and is fixedly connected to the core pressure plate 12.

[0084] The stator base 3 includes a first ring plate 15, a cone cylinder 16, a second ring plate 17, a stiffener 18, and a cylinder 19. There are multiple stiffeners 18. The first ring plate 15, the cone cylinder 16, the second ring plate 17, the cylinder 19, and the inner diameter of the core 2 form an annular space. The stiffeners 18 divide the annular space into several uniformly distributed cold air cavities 6 and hot air cavities 9.

[0085] The cold air chamber 6 and the hot air chamber 9 are distributed at intervals along the circumference of the iron core 2.

[0086] In S1, the rotor includes a rotor base 20 and a magnet 21. A heat insulation layer 22 is provided on the inner diameter surface of the magnet 21, and a heat-conducting layer 23 is provided between the outer diameter side of the magnet 21 and the rotor base 20.

[0087] In S3, the stator core ventilation duct 7 is formed by the ventilation channel steel 14, the stator coil 11 and the core 2.

[0088] More preferably, in S3, the stator coil 11 is embedded and fixed in the stator core slot 10 by the slot bottom pad 24, the interlayer pad 25, the wedge pad 26 and the slot wedge 27.

[0089] The outer diameter of the core 2 of the stator 1 is 15 mm larger than the outer diameter of the distribution circle of the slot wedge 27.

[0090] The heat insulation layer 22 is made of plastic.

[0091] The thermally conductive layer 23 is thermally conductive silicone.

[0092] This embodiment is the best implementation method. A heat-conducting layer 23 is provided between the outer diameter side of the magnet 21 and the rotor frame 20. The heat-conducting layer 23 is thermally conductive silicone, which further enhances the heat exchange with the rotor frame 20. The eddy current loss caused by stator harmonics to the magnet 21 is transferred to the rotor frame 20 through the magnet 21 and the high thermal conductivity material, and then carried away by the heat exchange between the outer surface of the rotor and the atmosphere, thereby ensuring the performance of the magnet 21.

[0093] The basic principle of this invention is as follows:

[0094] By setting an air gap 4 between the stator 1 and the rotor, the cooling fan introduces cooling air into the cold air cavity 6 of the cold air zone 5 of the stator frame 3. The cooling air enters the air gap 4 through the cold air cavity 6 and the stator core ventilation channel 7 in sequence, and then enters the hot air cavity 9 of the hot air zone 8 of the stator frame 3 through the stator core ventilation channel 7. Compared with the traditional method of sending cooling air in through the air gaps at both ends and cooling through the stator ventilation groove, this specific air gap flow method significantly reduces ventilation resistance, which is beneficial for the selection of cooling fans. Moreover, due to the effect of the cold air cavity 6 and the hot air cavity 9, the axial distribution of the air velocity through the stator core ventilation channel 7 is more uniform than that of the traditional structure, which is conducive to improving the cooling effect.

Claims

1. A method for air gap-flow ventilation cooling of a long-core low-speed wind turbine, characterized in that, Includes the following steps: S1. A stator frame (3) with a ventilation cavity is provided on the inner diameter side of the iron core (2) of the stator (1), and an air gap (4) is provided between the stator (1) and the rotor. S2. Cooling air is introduced into the cold air cavity (6) of the cold air zone (5) of the stator frame (3) by means of a cooling fan; S3. Cooling air enters the air gap (4) through the cold air cavity (6) and the stator core ventilation channel (7) in sequence, and then enters the hot air cavity (9) of the hot air zone (8) of the stator frame (3) through the stator core ventilation channel (7) to cool the stator core (2) and the stator coil (11) embedded in the stator core slot (10).

2. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 1, characterized in that: In S1, the stator (1) includes a core pressure plate (12), a tensioning screw (13), a stator coil (11), a core (2), and a stator frame (3). The core (2) is divided into multiple segments, and a stator core slot (10) is provided on the core (2). A ventilation channel steel (14) is provided between any two adjacent core segments (2). The tensioning screw (13) passes through multiple core segments (2) and is fixedly connected to the core pressure plate (12).

3. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 1, characterized in that: The stator base (3) includes a first ring plate (15), a cone (16), a second ring plate (17), a stiffener (18), and a cylinder (19). There are multiple stiffeners (18). The inner diameter of the first ring plate (15), the cone (16), the second ring plate (17), the cylinder (19), and the core (2) forms an annular space. The stiffeners (18) divide the annular space into several uniformly distributed cold air cavities (6) and hot air cavities (9).

4. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 1, characterized in that: The cold air chamber (6) and the hot air chamber (9) are distributed at intervals along the circumference of the iron core (2).

5. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 1, characterized in that: In S1, the rotor includes a rotor base (20) and a magnet (21). A heat insulation layer (22) is provided on the inner diameter surface of the magnet (21), and a heat-conducting layer (23) is provided between the outer diameter side of the magnet (21) and the rotor base (20).

6. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 2, characterized in that: In S3, the stator core ventilation channel (7) is formed by ventilation channel steel (14), stator coil (11) and core (2).

7. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 1, characterized in that: In S3, the stator coil (11) is embedded and fixed in the stator core slot (10) by the slot bottom pad (24), the interlayer pad (25), the wedge pad (26) and the slot wedge (27).

8. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 7, characterized in that: The outer diameter of the core (2) of the stator (1) is 10-15 mm larger than the outer diameter of the distribution circle of the slot wedge (27).

9. The air gap bypass ventilation cooling method for a long-core low-speed wind turbine according to claim 5, characterized in that: The heat insulation layer (22) is made of stainless steel or plastic.

10. A method for air gap-flow ventilation and cooling of a long-core low-speed wind turbine according to claim 5, characterized in that: The thermally conductive layer (23) is thermally conductive silicone.

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