Seaborne distributed permanent magnet wind driven generator closed cooling system and cooling method thereof

Abstract

The invention belongs to the technical field of wind power generation, and relates to an offshore distributed permanent magnet wind driven generator closed cooling system and a cooling method thereof. According to the internal circulation closed cooling loop of the permanent magnet generator, internal circulation cold air is obtained from a cabin, enters the generator through a rear end cover, forms hot air after taking away heat and enters the air cooling heat exchanger, the air cooling heat exchanger cools the hot air to form cold air, and the cold air is discharged into the cabin in a forced ventilation mode. Internal circulation air in the whole cooling loop does not make contact with the outside, and a closed-loop cooling structure is formed.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power generation, and relates to a closed cooling system of an offshore distributed permanent magnet wind turbine generator and a cooling method thereof. Background Art

[0002] Distributed wind power generation is a new type of power generation and comprehensive energy utilization. It is generally a small wind power generation system with a small capacity. It has many application scenarios, strong environmental adaptability, independent power stations, high safety and stability, and low cost. Therefore, it has a good market prospect. Due to the rich offshore wind energy resources and the development of technology, the wind power market has a good prospect.

[0003] At present, the two mainstream cooling methods in the existing wind turbine cooling technology are mainly air cooling and water cooling. Air cooling is the earliest and most widely used cooling technology for wind turbines. It is suitable for units with low loss and small single capacity. Its advantages are simple structure, low cost and convenient maintenance and management. Its disadvantages are that the temperature in the cabin is prone to rising and thus failures occur. In addition, dust, particles and salt spray can easily enter the cabin and corrode the generator components, which is not conducive to the long-term reliable and safe operation of wind turbines (especially offshore wind turbines). Water cooling has significant advantages in heat dissipation capacity and compact structure, which is suitable for offshore wind turbines. However, the working fluid is usually ethylene glycol and water solution, which has the risk of water leakage, affecting the long-term reliable operation of the unit, and requires the unit to design a set of dedicated water supply and air-water heat exchange system, which is costly.

[0004] At the same time, the existing offshore distributed permanent magnet wind turbine cooling system technical solutions have the following disadvantages:

[0005] If the air cooling method on the surface of the base is used for heat dissipation, the temperature of the windings and magnetic steel will be too high, and the performance and reliability of the generator cannot be met; if the natural wind direct cooling system is used, the generator cannot operate reliably for a long time at sea.

[0006] If a water cooling system is used, the cost is high, and there is a risk of leakage of the working fluid leading to insulation failure and major accidents of the generator;

[0007] Therefore, for offshore distributed small-power units, if the water cooling commonly used in offshore wind turbines is adopted, an additional set of water cooling equipment will be required, which is costly and less economical. If the surface base heat dissipation rib air cooling is adopted, the internal magnetic steel temperature will be high and the motor performance will not meet the requirements. If the performance of the magnetic steel is considered to be improved, the cost of heavy rare earth will increase significantly. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a closed cooling system for an offshore distributed permanent magnet wind turbine generator and a cooling method thereof.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A closed cooling system for an offshore distributed permanent magnet wind turbine generator comprises a nacelle, the front end of which is connected to a generator base, an air-cooled heat exchanger is arranged outside the nacelle, and a generator air inlet and a generator air outlet are arranged on a rear end cover of the generator;

[0011] The hot air in the generator flows out from the generator air outlet and flows through the air inlet pipe assembly in turn into the air-cooled heat exchanger. The air-cooled heat exchanger cools the hot air to form cooling air. The cooling air discharged from the air-cooled heat exchanger is discharged into the cabin through the air outlet pipe assembly in turn, and the cold air in the cabin enters the generator through the generator air inlet.

[0012] Furthermore, ventilation holes are provided on the rotor bracket in the generator, and an air guide cover is arranged between the rotor bracket and the rear end cover, and the air guide cover is connected to the inner wall of the rear end cover; after the cold air enters from the air inlet of the generator, it flows along the gap between the air guide cover, the stator and the rotor, and the ventilation holes, and flows into the hot air inlet of the air-cooled heat exchanger.

[0013] Furthermore, a frame is provided in the cabin, and the fan motor impeller assembly is arranged on the frame through a mounting base.

[0014] Furthermore, the air inlet pipeline assembly includes an air inlet pipeline and a first connecting pipeline, the air outlet pipeline assembly includes a second connecting pipeline, an air outlet pipeline, and a fan motor impeller assembly, the generator air outlet is connected to the air inlet pipeline, the first connecting pipeline, and the hot air inlet of the air-cooling heat exchanger in sequence; the cooling air outlet of the air-cooling heat exchanger is connected to the second connecting pipeline, the air outlet pipeline, and the fan motor impeller assembly in sequence.

[0015] Furthermore, the fan motor impeller assembly includes an impeller and a fan motor capable of driving the impeller to rotate, and the cooling air can be drawn from the air-cooled heat exchanger and discharged into the cabin through the rotation of the impeller.

[0016] Furthermore, the air-cooled heat exchanger includes a shell, a heat exchange core is arranged in the shell, the shell is exposed above the cabin through the heat exchanger base, and flanges are arranged at the hot air inlet and the cooling air outlet of the air-cooled heat exchanger.

[0017] Furthermore, the heat exchange core adopts a cross-flow plate heat exchanger.

[0018] Furthermore, the generator air inlet includes air inlets of various specifications.

[0019] Furthermore, the ventilation hole is located on the middle partition of the rotor bracket, and the ventilation hole is arranged between two adjacent rib plates.

[0020] Furthermore, hoses are provided between the air inlet pipeline and the rear end cover of the generator, and between the second connecting pipeline and the air outlet pipeline.

[0021] In addition, the present invention also provides a cooling method for a closed cooling system of an offshore distributed permanent magnet wind turbine generator, comprising the following steps:

[0022] Step 1: The hot air in the generator flows out from the generator air outlet, flows through the air inlet and outlet pipe components in sequence, and then enters the air-cooled heat exchanger through the hot air inlet of the air-cooled heat exchanger;

[0023] Step 2: The air-cooled heat exchanger cools the hot air to form cooling air;

[0024] Step 3: The cooling air discharged from the air-cooling heat exchanger flows through the cooling air outlet of the air-cooling heat exchanger, passes through the air outlet pipe assembly in sequence, and is then discharged into the cabin;

[0025] Step 4: The cold air in the cabin enters the generator through the generator air inlet. After entering the generator air inlet, the cold air flows along the air guide cover, the gap between the stator and the rotor, and the ventilation holes, and flows into the hot air inlet of the air cooling exchanger.

[0026] Wherein: the cooling medium of the air-cooled heat exchanger in step 2 is natural wind from the atmosphere, which forms convection heat exchange with the internal circulation cooling wind.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] First, the present invention designs an internal circulation closed cooling circuit for a permanent magnet generator. The internal circulation cold air is obtained from the engine room, enters the generator through the rear end cover, takes away the heat and forms hot air to enter the air-cooled heat exchanger. The air-cooled heat exchanger cools the hot air to form cold air, which is discharged into the engine room by forced ventilation. The internal circulation air in the overall cooling circuit has no contact with the outside world, forming a closed-loop cooling structure; the use of this closed cooling circulation system can meet the operating requirements of harsh offshore / offshore working conditions and ensure the reliability of the generator.

[0029] Second, on the basis of air cooling on the surface of the generator frame, an internal forced ventilation cooling method is added. The temperature of the generator stator winding and rotor magnetic steel meets the use requirements and can ensure the normal operation of the generator.

[0030] Third, in view of the offshore operating environment, an air cooling system is used to replace the current mainstream water cooling method of large-power wind turbines, which reduces the complexity of the water cooling system and reduces the cost of the unit.

[0031] Fourth, the cooling system has a compact structure and effectively utilizes the internal and external space of the cabin, which is conducive to the maintenance of the unit throughout its life cycle. In addition, the heat exchange core is placed outside the cabin, effectively utilizing the natural wind from the atmosphere, and wearing parts such as the fan motor impeller assembly are placed inside the cabin to facilitate daily maintenance and inspection.

[0032] Fifth, the internal cooling air path of the generator is only axially ventilated, and no radial ventilation duct is required, which reduces the axial size of the generator, thereby reducing the amount of effective materials used and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0036] Figure 2 This is a schematic diagram of the internal structure of the cabin of the present invention;

[0037] Figure 3 This is a schematic diagram of the internal structure of the generator frame of the present invention;

[0038] Figure 4 It is a schematic diagram of the air duct direction of the cooling system of the present invention in the air-cooled heat exchanger;

[0039] Figure 5 It is a structural schematic diagram of the air-cooled heat exchanger of the present invention;

[0040] Figure 6 It is a structural schematic diagram of the rear end cover of the generator of the present invention;

[0041] Figure 7 Schematic diagram of the generator rotor of the present invention.

[0042] Among them: 1 is the cabin; 2 is the generator base; 3 is the air-cooled heat exchanger; 4 is the rear end cover; 4.1 is the generator air inlet; 4.2 is the generator air outlet; 5 is the air inlet pipeline; 6.1 is the first connecting pipeline; 6.2 is the second connecting pipeline; 7 is the air outlet pipeline; 8 is the fan motor impeller assembly; 9 is the mounting base; 10 is the frame; 10.1 is the frame platform; 11 is the air guide cover; 12 is the generator stator; 13 is the rotor bracket; 13.1 is the ventilation hole. DETAILED DESCRIPTION

[0043] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices consistent with some aspects of the present invention as detailed in the appended claims.

[0044] Example

[0045] A closed cooling system for an offshore distributed permanent magnet wind turbine generator comprises a nacelle 1, the front end of which is connected to a generator base 2, an air-cooling heat exchanger 3 is arranged outside the nacelle 1, and a generator air inlet 4.1 and a generator air outlet 4.2 are arranged on a rear end cover 4 of the generator;

[0046] The hot air in the generator flows out from the generator air outlet 4.2 and then flows through the air inlet pipe assembly into the air-cooling heat exchanger 3. The air-cooling heat exchanger 3 cools the hot air to form cooling air. The cooling air discharged from the air-cooling heat exchanger 3 is discharged into the nacelle 1 through the air outlet pipe assembly in turn, and the cold air in the nacelle 1 enters the generator through the generator air inlet 4.1.

[0047] In this embodiment: the cooling system of the present invention is suitable for offshore distributed small-power permanent magnet wind turbines, the overall structure of the generator is an outer stator and an inner rotor, and the loss is dissipated by two parts: one is dissipated by the surface of the base, and the other is dissipated by the closed internal circulation cooling system of the present invention.

[0048] like Figure 1-3 As shown, the generator base 2 is exposed to the atmosphere, and its rear end is connected to the front end of the nacelle 1. Two sets of generator air inlets 4.1 are evenly distributed on the rear end cover 4 of the generator. Cooling air is obtained from the nacelle 1 through the generator air inlet 4.1 and enters the generator. After taking away the heat, the hot air enters the air inlet pipeline assembly from the generator air outlet 4.2 of the rear end cover 4, and enters the air cooling heat exchanger 3. The air cooling heat exchanger 3 cools the generator hot air through the natural wind of the outside atmosphere, so that it is cooled down to form cooling air, and then flows through the connecting pipeline 6 on the other side, enters the air outlet pipeline assembly of the air cooling heat exchanger 3, and the cold air cooled by the air heat exchanger 3 is discharged into the nacelle 1. The generator air inlet 4.1 of the rear end cover 4 then allows the cold air in the nacelle 1 to enter the generator, thus forming a closed-loop cooling. The circulating air in the generator does not contact the outside world, which can ensure the reliable operation of the generator at sea.

[0049] Furthermore, a ventilation hole 13.1 is provided on the rotor bracket 13 in the generator base 2, and an air guide cover 11 is provided between the rotor bracket 13 and the rear end cover 4, and the air guide cover 11 is connected to the inner wall of the rear end cover 4. Specifically, the air guide cover 11 is an annular cylindrical part, which is welded and fixed to the inner surface of the rear end cover 4; after the cold air enters from the generator air inlet 4.1, it flows along the air guide cover 11, the gap between the stator and the rotor, and the ventilation hole 13.1, and flows into the hot air inlet of the air-cooled heat exchanger 3.

[0050] In this embodiment: the air guide cover 11 in the generator is used to isolate the generator stator 12 and the rotor, and the cooling air obtains cold air from the nacelle 1 through the generator air inlet 4.1 and enters the generator, passes through the air gap along the air guide cover 11 and takes away the heat of the generator; the rotor bracket 13 is evenly distributed with ventilation holes 13.1, and the hot air that takes away the heat passes through the ventilation holes of the generator rotor, reaches the generator air outlet 4.2 of the rear end cover 4, and enters the air inlet duct assembly.

[0051] Furthermore, a frame 10 is provided in the nacelle 1 , and the fan motor impeller assembly 8 is provided on the frame 10 via a mounting base 9 .

[0052] Furthermore, if Figure 4 As shown, the air inlet pipeline assembly includes an air inlet pipeline 5 and a first connecting pipeline 6.1, the air outlet pipeline assembly includes a second connecting pipeline 6.2, an air outlet pipeline 7, and a fan motor impeller assembly 8, the generator air outlet 4.2 is connected to the air inlet pipeline 5, the first connecting pipeline 6.1, and the hot air inlet of the air-cooling heat exchanger 3 in sequence; the cooling air outlet of the air-cooling heat exchanger 3 is connected to the second connecting pipeline 6.2, the air outlet pipeline 7, and the fan motor impeller assembly 8 in sequence.

[0053] Furthermore, the fan motor impeller assembly 8 includes an impeller and a fan motor capable of driving the impeller to rotate. The rotation of the impeller can extract cooling air from the air-cooled heat exchanger 3 and discharge it into the cabin 1. The fan motor impeller assembly 8 serves as a forced ventilation component to discharge the cold air after cooling the air-cooled heat exchanger 3 into the cabin 1.

[0054] Furthermore, if Figure 5 As shown, the air-cooled heat exchanger 3 includes a shell 3.3, in which a heat exchange core 3.4 is arranged. The shell 3.3 is exposed above the cabin 1 through a heat exchanger base 3.1. Flanges 3.2 are arranged at the hot air inlet and the cooling air outlet of the air-cooled heat exchanger 3. The air-cooled heat exchanger 3 of the generator is connected and fixed above the cabin 1 through the heat exchanger base 3.1.

[0055] Furthermore, the heat exchange core 3.4 adopts a cross-flow plate heat exchanger.

[0056] The air-cooling heat exchange system is composed of an air inlet pipeline 5, a connecting pipeline 6, an air outlet pipeline 7, a fan motor impeller assembly 8, and a base support 9. The air inlet pipeline 5 connects the rear end cover 4 and the connecting pipeline 6, and the air outlet pipeline 7 connects the fan motor impeller assembly 8 and the connecting pipeline 6. The fan motor impeller assembly 8 includes two major parts: a fan motor and an impeller. The motor drives the impeller to rotate, extracts the cold air after heat exchange, and discharges it into the cabin 1. A mounting base 9 is provided at the bottom thereof for fixing it on the platform 10.1 of the frame 10, wherein the connecting pipeline 6 includes a first connecting pipeline and a second connecting pipeline.

[0057] From Figure 5 As shown, the air-cooled heat exchanger 3 is composed of a heat exchanger base 3.1, a flange 3.2, a shell 3.3, a heat exchange core 3.4, and a lifting lug 3.5. The heat exchanger base 3.1 is arranged outside the nacelle 1, and its primary cooling medium is natural wind. Figure 5 The arrow shown enters, cools the circulating air in the generator, and then flows out from the other side. Flange 3.2 connects the connecting pipe 6 of the air inlet and outlet of the nacelle 1 and the shell 3.3. In order to improve the heat exchange efficiency and environmental adaptability, the heat exchange core 3.4 can adopt a cross-flow plate heat exchanger, and the material can be epoxy resin aluminum foil. The lifting lug 3.5 is used to install and lift the air-cooled heat exchanger 3; the shell 3.3 is a stainless steel shell.

[0058] Furthermore, the generator air inlet 4.1 includes air inlets of various specifications. Figure 6 As shown, the rear end cover 4 of the generator is evenly distributed with two types of air inlets 4.1, including larger-sized air inlets and smaller-sized air inlets, to ensure uniform air intake and reduce the difference in temperature rise inside the generator. A cover plate is provided on each air inlet 4.1. Preferably, a stainless steel wire mesh is used as the cover plate to prevent foreign matter from entering the generator. To ensure smooth air flow and facilitate pipeline setting, the air outlet 4.2 is arranged above the rear end cover 4 of the generator and is connected to the generator outlet pipeline 5.

[0059] Furthermore, if Figure 7 As shown, the ventilation hole 13.1 is located on the middle partition of the rotor bracket 13, and the ventilation hole 13.1 is arranged between two adjacent rib plates; on the middle partition of the generator rotor 13, ventilation holes 13.1 are evenly distributed between the rib plates for internal circulation air flow.

[0060] Furthermore, a hose is provided between the air inlet duct 5 and the rear end cover 4 of the generator, between the second connecting duct 6.2 and the air outlet duct 7. To ensure the operability of the connection, a hose is provided between the air inlet duct 5 and the air outlet duct 7, and the hose material can be selected from rubber or canvas.

[0061] In addition, the present invention also provides a cooling method for a closed cooling system of an offshore distributed permanent magnet wind turbine generator, comprising the following steps:

[0062] Step 1: The hot air in the generator flows out from the generator air outlet 4.2, flows through the air inlet and outlet pipe components in sequence, and then enters the air cooling heat exchanger 3 through the hot air inlet of the air cooling heat exchanger 3;

[0063] Step 2: The air-cooling heat exchanger 3 cools down the hot air to form cooling air;

[0064] Step 3: The cooling air discharged from the air-cooling heat exchanger 3 flows through the cooling air outlet of the air-cooling heat exchanger 3 in sequence through the air outlet pipeline assembly and then is discharged into the cabin 1;

[0065] Step 4: The cold air in the nacelle 1 enters the generator through the generator air inlet 4.1. After entering the generator air inlet 4.1, the cold air flows along the air guide cover 11, the gap between the stator and the rotor, and the ventilation hole 13.1, and flows into the hot air inlet of the air cooling exchanger.

[0066] The present invention designs a closed cooling circuit for internal circulation of a permanent magnet generator. The internal circulation cold air is obtained from the nacelle 1, enters the interior of the generator through the rear end cover 4, takes away the heat to form hot air and enters the air-cooled heat exchanger 3. The air-cooled heat exchanger 3 cools the hot air to form cold air, and discharges it into the interior of the nacelle 1 by forced ventilation. The internal circulation air in the overall cooling circuit has no contact with the outside world, forming a closed-loop cooling structure. In addition, a closed air cooling system is formed, including a fan motor impeller assembly 8 with a forced ventilation function, a heat exchange core 3.4, a ventilation pipeline and a housing 3.3. The external wind path of the system makes full use of the natural wind from the atmosphere, fully utilizes the space of the unit, and is connected and fixed to the main components of the generator such as the rear end cover 4, the nacelle 1 and the frame 10; in addition, the internal cooling structure of the generator includes: the rear end cover 4 is provided with a generator air inlet 4.1 and a generator air outlet 4.2, an air guide cover 11 is arranged between the rotor bracket 13 and the inner wall of the generator base 2, and the rotor bracket 13 is provided with ventilation holes 13.1 for circulating air to ensure that the air cooling circuit inside the motor is unobstructed.

[0067] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0068] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A closed cooling system for an offshore distributed permanent magnet wind turbine generator, characterized in that: The invention comprises a nacelle (1), wherein the front end of the nacelle (1) is connected to a generator base (2), an air-cooling heat exchanger (3) is arranged outside the nacelle (1), and a generator air inlet (4.1) and a generator air outlet (4.2) are arranged on a rear end cover (4) of the generator; After the hot air in the generator flows out from the generator air outlet (4.2), it flows through the air inlet pipeline assembly in sequence and enters the air-cooling heat exchanger (3). The air-cooling heat exchanger (3) cools the hot air to form cooling air. The cooling air discharged from the air-cooling heat exchanger (3) is discharged into the cabin (1) in sequence through the air outlet pipeline assembly. The cooling air in the cabin (1) enters the generator through the generator air inlet (4.1).

2. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 1, characterized in that: A rotor support (13) in the generator is provided with a ventilation hole (13.1); an air guide cover (11) is provided between the rotor support (13) and the rear end cover (4); the air guide cover (11) is connected to the inner wall of the rear end cover (4); after the cold air enters from the generator air inlet (4.1), it flows along the air guide cover (11), the gap between the stator and the rotor, and the ventilation hole (13.1), and flows into the hot air inlet of the air-cooled heat exchanger (3).

3. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 2, characterized in that: The ventilation hole (13.1) is located on the middle partition plate of the rotor support (13), and the ventilation hole (13.1) is arranged between two adjacent rib plates.

4. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 1, characterized in that: A frame (10) is arranged in the cabin (1), and the fan motor impeller assembly (8) is arranged on the frame (10) via a mounting base (9).

5. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 1, characterized in that: The air-cooled heat exchanger (3) comprises a shell (3.3), a heat exchange core (3.4) is arranged in the shell (3.3), the shell (3.3) is exposed above the cabin (1) through a heat exchanger base (3.1), and flanges (3.2) are arranged at the hot air inlet and the cooling air outlet of the air-cooled heat exchanger (3).

6. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 5, characterized in that: The heat exchange core (3.4) adopts a cross-flow plate heat exchanger.

7. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 1, characterized in that: The fan motor impeller assembly (8) comprises an impeller and a fan motor capable of driving the impeller to rotate, and the rotation of the impeller can extract cooling air from the air-cooled heat exchanger (3) and discharge it into the cabin (1).

8. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 1, characterized in that: The air inlet pipeline assembly comprises an air inlet pipeline (5) and a first connecting pipeline (6.1); the air outlet pipeline assembly comprises a second connecting pipeline (6.2), an air outlet pipeline (7), and a fan motor impeller assembly (8); the generator air outlet (4.2) is connected in sequence to the air inlet pipeline (5), the first connecting pipeline (6.1), and a hot air inlet of an air-cooled heat exchanger (3); and the cooling air outlet of the air-cooled heat exchanger (3) is connected in sequence to the second connecting pipeline (6.2), the air outlet pipeline (7), and the fan motor impeller assembly (8).

9. The closed cooling system for an offshore distributed permanent magnet wind turbine generator according to claim 8, characterized in that: Flexible hoses are provided between the air inlet pipeline (5) and the rear end cover (4), and between the second connecting pipeline (6.2) and the air outlet pipeline (7).

10. A cooling method for a closed cooling system of an offshore distributed permanent magnet wind turbine generator as claimed in claims 1 to 9, characterized in that: The following steps are involved: Step 1: The hot air in the generator flows out from the generator air outlet (4.2), flows through the air inlet and outlet pipe components in sequence, and then enters the air-cooled heat exchanger (3) through the hot air inlet of the air-cooled heat exchanger (3); Step 2: The air-cooled heat exchanger (3) cools the hot air to form cooling air; Step 3: The cooling air discharged from the air-cooling heat exchanger (3) flows through the cooling air outlet of the air-cooling heat exchanger (3) in sequence through the air outlet pipeline assembly and then is discharged into the cabin (1); Step 4: The cold air in the nacelle (1) enters the generator through the generator air inlet (4.1). After entering the generator air inlet (4.1), the cold air flows along the air guide cover (11), the gap between the stator and the rotor, and the ventilation hole (13.1), and flows into the hot air inlet of the air cooling exchanger.

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