Flywheel energy storage cooling device and flywheel energy storage equipment

Abstract

The application discloses a flywheel energy storage cooling device and flywheel energy storage equipment, and belongs to the flywheel energy storage field.The flywheel energy storage cooling device comprises a main shaft, a motor rotor and a flywheel which are fixed outside the main shaft, a through hole is formed in the main shaft, and an internal cooling assembly is arranged in the main shaft.The internal cooling assembly comprises a radiation heat exchange part which is fixed in the main shaft and a through groove which is formed in the center of the radiation heat exchange part and is connected with the through hole.The internal cooling assembly is formed by the heat pipe and the radiation heat exchange part, the heat pipe is designed as a tapered structure with the diameter of the upper condensing end being smaller than the diameter of the lower evaporating end, the centrifugal force generates a downward component force along the slope when the heat pipe rotates at a high speed along with the main shaft, the condensing end liquid working medium is continuously returned to the evaporating end, and therefore, the high-efficiency and reliable heat pipe circulation cooling is realized without external pump driving, and the problems of long heat dissipation path and low cooling efficiency of the motor rotor in the vacuum environment are solved.

Description

Technical Field

[0001] This invention relates to the field of flywheel energy storage, and more specifically, to a cooling device and a flywheel energy storage equipment for flywheel energy storage. Background Technology

[0002] Flywheel energy storage is a physical energy storage technology that utilizes the kinetic energy of a high-speed rotating flywheel to store and release electrical energy. A typical flywheel energy storage system consists of a flywheel rotor, a motor / generator, a bearing support system, a vacuum casing, and corresponding power electronic conversion devices. During charging, the motor drives the flywheel to accelerate its rotation, converting electrical energy into kinetic energy for storage; during discharging, the flywheel decelerates and drives the generator to generate electricity, converting the kinetic energy back into electrical energy. Flywheel energy storage has significant advantages such as high power density, fast response speed, long cycle life, high charge / discharge efficiency, and environmental friendliness, and is widely used in power grid frequency regulation and peak shaving, uninterruptible power supplies (UPS), rail transit braking energy recovery, and aerospace fields.

[0003] However, during high-speed operation, the motor rotor of a flywheel energy storage system continuously generates a large amount of heat due to electromagnetic losses and mechanical friction. If this heat cannot be dissipated effectively and in a timely manner, it will lead to excessively high temperatures in the motor rotor and spindle, affecting the insulation performance of the motor windings, bearing life, and the overall operational stability of the system, and in severe cases, even causing equipment damage. Since the motor rotor and flywheel of a flywheel energy storage system are typically located in a vacuum environment to reduce wind resistance losses, traditional air-cooling and liquid-cooling methods cannot be directly applied inside the vacuum chamber, making heat dissipation for the high-speed rotating motor rotor a major technical challenge. Existing cooling solutions for motor rotors in a vacuum environment often suffer from long heat exchange paths, high thermal resistance, and low cooling efficiency, making it difficult to meet the heat dissipation performance requirements of flywheel energy storage systems under high power density conditions. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide a cooling device and a flywheel energy storage device for flywheel energy storage.

[0005] To solve the above problems, the present invention adopts the following technical solution.

[0006] A cooling device for flywheel energy storage includes a main shaft, a motor rotor fixed outside the main shaft, and a flywheel;

[0007] The spindle has a through hole inside and a built-in cooling assembly inside. The built-in cooling assembly includes a radiative heat exchange section fixed inside the spindle, a through groove opened at the center of the radiative heat exchange section and connected to the through hole, and multiple heat pipes fixed inside the spindle.

[0008] A heat exchange rod is inserted inside the through hole, the heat pipe is coaxially arranged with the through hole, and both ends of the heat exchange rod are connected to the second outer shell;

[0009] Multiple heat pipes are evenly distributed in a circumferential array and fixed inside the main shaft. The upper end of each heat pipe is the condensation end and is connected to the lower end of the radiative heat exchange section, while the lower end of the heat pipe is the evaporation end.

[0010] The diameter of the upper end of the heat pipe is smaller than the diameter of the lower end of the heat pipe, so that the outer and inner walls of the heat pipe form a slope.

[0011] Furthermore, the heat exchange rod is integrally formed with a corrugated flange on the outside, and a corrugated groove is formed on the inner wall of the internal through groove of the radiative heat exchange section. The corrugated flange and the corrugated groove cooperate to increase the radiative heat exchange area.

[0012] Furthermore, a spiral groove is formed on the inner wall of the through hole, and a surface turbulence structure with the opposite direction to the spiral groove is integrally formed on the outer surface of the heat exchange rod.

[0013] Furthermore, it also includes a drive motor and a second gear. The output shaft of the drive motor is connected to the second gear. A first gear that meshes with the second gear is fixed to the outside of the heat exchange rod. The drive motor drives the heat exchange rod to rotate in the through hole in the opposite direction to the main shaft through the first gear and the second gear.

[0014] Furthermore, multiple blades are fixed to the outside of the heat exchange rod. The multiple blades are uniformly fixed to the outside of the heat exchange rod in a circumferential array, and the blades are located at the opening of the through hole.

[0015] Furthermore, it also includes a liquid flow heat exchange assembly, which includes a hollow cavity opened inside the heat exchange rod and two rotary joints respectively disposed at both ends of the heat exchange rod, with the inner tubes of the two rotary joints fixedly inserted into the hollow cavity.

[0016] Furthermore, it also includes a first outer shell disposed outside the second outer shell, a vacuum chamber being formed between the first outer shell and the second outer shell, the main shaft being rotatably connected to the second outer shell via an electromagnetic bearing, and both ends of the main shaft penetrating the second outer shell and extending into the vacuum chamber;

[0017] Two sets of second magnetohydrodynamic sealing parts are provided between the outer wall of the main shaft and the inner wall of the second housing. The two sets of second magnetohydrodynamic sealing parts are used to seal the cavity inside the second housing and to separate the cavity inside the second housing from the vacuum chamber.

[0018] The vacuum chamber is connected to a through hole inside the spindle.

[0019] Furthermore, the motor rotor and flywheel are both located inside the second housing, and the motor stator is also fixed inside the second housing. Multiple water jacket cooling sections are fixed outside the second housing, and the multiple water jacket cooling sections are used to cool and reduce the temperature of the electromagnetic bearing, the second magnetohydrodynamic seal, and the motor stator.

[0020] Furthermore, both ends of the heat exchange rod are rotatably connected to the inside of the first housing, and a first magnetic fluid sealing part is provided at the rotatable connection between the heat exchange rod and the first housing. The first magnetic fluid sealing part seals the rotatable connection and isolates the vacuum chamber inside the first housing from the atmosphere outside the first housing.

[0021] Furthermore, the drive motor is fixed to the upper end of the first housing, and both the first gear and the second gear are rotatably connected inside the first housing.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) This solution sets up an internal cooling assembly consisting of a heat pipe and a radiative heat exchanger inside the main shaft, and designs the heat pipe as a conical structure with a diameter of the upper condensing end smaller than that of the lower evaporating end. When the heat pipe rotates at high speed with the main shaft, the centrifugal force generates a downward component along the inclined plane, driving the liquid working fluid at the condensing end to continuously flow back to the evaporating end. Thus, efficient and reliable heat pipe circulation cooling is achieved without external pump drive, effectively solving the problem of long heat dissipation path and low cooling efficiency of motor rotor in vacuum environment.

[0024] (2) This scheme increases the radiation heat transfer area by setting a corrugated flange on the outside of the heat exchange rod and setting a matching corrugated groove on the inner wall of the radiation heat transfer section. At the same time, low-pressure helium is introduced into the vacuum chamber. The surface turbulence structure with the spiral groove on the inner wall of the main shaft through hole and the surface of the heat exchange rod in opposite directions generates continuous shear disturbance when they rotate relative to each other, which destroys the laminar boundary layer and drives the helium to directional convection. The radiation heat transfer and the convection heat transfer work together to further improve the heat transfer efficiency.

[0025] (3) This scheme drives the heat exchange rod to rotate continuously or intermittently in the opposite direction by driving the motor, so that the spiral pattern forms a bidirectional active shearing, which increases the relative shearing speed felt by the helium from the main shaft speed to the sum of the main shaft and heat exchange rod speeds, significantly enhancing the turbulence promotion effect in low-pressure helium; at the same time, the blades at the end of the heat exchange rod rotate accordingly, driving the helium to directional circulation flow in the same way as the working principle of an axial flow fan, improving the gas circulation efficiency in the through hole and vacuum chamber, and further enhancing the cooling and heat dissipation effect.

[0026] (4) This solution introduces circulating coolant by setting a hollow cavity inside the heat exchange rod and using a rotary joint. Taking advantage of the fact that the specific heat capacity of the liquid is much greater than that of the gas, the surface of the heat exchange rod is forced to be kept at a low temperature, and a stable temperature difference is maintained between the heat exchange rod and the main shaft and the radiative heat exchange part, so as to achieve efficient heat transfer. At the same time, the water jacket cooling part set outside the second shell cools the motor stator, electromagnetic bearing and magnetohydrodynamic seal, and constructs a multi-path heat dissipation channel from the inside of the rotor to the outside water jacket, which reduces the temperature rise of the motor rotor in the vacuum environment and improves the high-speed operation stability of the equipment. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the main shaft, motor rotor, flywheel, and through-hole structure of the present invention;

[0028] Figure 2 This is a sectional view of the main axis of the present invention;

[0029] Figure 3 This is a cross-sectional view of the heat exchange rod and liquid flow heat exchange assembly of the present invention;

[0030] Figure 4 This is a schematic diagram of the corrugated flange, heat exchange rod, surface turbulence structure, and blade structure of the present invention.

[0031] Figure 5 This is a schematic diagram showing the positional relationship between the blade and the through hole in this invention;

[0032] Figure 6 This is an overall sectional view of the flywheel energy storage device of the present invention;

[0033] Figure 7 This is a schematic diagram of the second outer shell and the water jacket cooling section of the present invention;

[0034] Figure 8 This is a schematic diagram of the overall structure of the flywheel energy storage device of the present invention.

[0035] Explanation of the labels in the diagram:

[0036] 1. Main shaft; 2. Motor rotor; 3. Flywheel; 4. Through hole; 5. Built-in cooling assembly; 51. Radiative heat exchange section; 52. Heat pipe; 53. Corrugated groove; 54. Heat exchange rod; 55. Corrugated flange; 6. Spiral groove; 7. Surface turbulence structure; 8. Fluid flow heat exchange assembly; 81. Hollow cavity; 82. Rotary joint; 83. First magnetohydrodynamic seal; 9. Blade; 10. First gear; 11. Drive motor; 12. Second gear; 13. First housing; 14. Second housing; 15. Vacuum chamber; 16. Electromagnetic bearing; 17. Second magnetohydrodynamic seal; 18. Water jacket cooling section; 19. Motor stator. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Please see Figures 1 to 8 A cooling device for flywheel energy storage includes a main shaft 1, a motor rotor 2 fixed outside the main shaft 1, and a flywheel 3.

[0039] The spindle 1 has a through hole 4 inside, and the spindle 1 also has a built-in cooling assembly 5 inside. The built-in cooling assembly 5 includes a radiative heat exchange part 51 fixed inside the spindle 1, a through groove opened at the center of the radiative heat exchange part 51 and connected to the through hole 4, and a plurality of heat pipes 52 fixed inside the spindle 1.

[0040] A heat exchange rod 54 is inserted inside the through hole 4. The heat pipe 52 is coaxially arranged with the through hole 4, and both ends of the heat exchange rod 54 are connected to the second outer shell 14.

[0041] Multiple heat pipes 52 are evenly distributed in a circumferential array and fixed inside the main shaft 1. The upper end of each heat pipe 52 is the condensation end and is connected to the lower end of the radiative heat exchange section 51, while the lower end of the heat pipe 52 is the evaporation end.

[0042] The diameter of the upper end of the heat pipe 52 is smaller than the diameter of the lower end of the heat pipe 52, so that the outer wall and the inner wall of the heat pipe 52 form an inclined surface, and the inclination angle of the inner wall of the heat pipe 52 relative to the axis of the main shaft 1 is between 1° and 3°.

[0043] The heat exchange rod 54 has an integrally formed corrugated flange 55 on its exterior, and a corrugated groove 53 is formed on the inner wall of the internal through groove of the radiative heat exchange section 51. The corrugated flange 55 and the corrugated groove 53 cooperate to increase the radiative heat exchange area. Furthermore, according to actual usage requirements, a high emissivity coating (such as silicon carbide, anodized aluminum, etc.) can be coated on the corrugated flange 55 and the corrugated groove 53 to enhance the effect. The thickness of the high emissivity coating is... .

[0044] By adopting the above technical solution, when the equipment is running, the flywheel 3, the motor rotor 2, and the main shaft 1 will rotate inside the equipment. The heat generated by the motor rotor 2 during operation can be conducted to the main shaft 1. Cooling with heat pipe 52 is a mature existing technology. In this application, the bottom of heat pipe 52 is a large-diameter evaporation end. The heat conducted from the motor rotor 2 to the main shaft 1 will accumulate at the evaporation end. The top of heat pipe 52 is a condensation end with a diameter smaller than the bottom diameter of heat pipe 52. Steam releases heat and condenses at the condensation end. Because the diameter of the evaporation end is larger and the diameter of the condensation end is smaller than that of the evaporation end, the inner wall of heat pipe 52 will exhibit a clear... With the obvious slope, when the heat pipe 52 rotates with the main shaft 1, the centrifugal force on the droplets generated at the condensation end will generate a downward component force along the conical wall. This component force will force the liquid working fluid attached to the wall to continuously flow back from the narrow condensation end to the wide evaporation end. Due to the larger diameter of the evaporation end and the inclined design, the liquid working fluid will be restricted to the evaporation end by centrifugal force during rotation. The heat generated at the condensation end of the heat pipe 52 is conducted to the radiative heat exchange section 51. The radiative heat exchange section 51 exchanges heat with the heat exchange rod 54 through radiative heat exchange, thereby achieving cooling and heat dissipation of the motor rotor 2.

[0045] like Figure 6 and Figure 7 As shown, it also includes a first housing 13 disposed outside the second housing 14, and a vacuum chamber 15 is formed between the first housing 13 and the second housing 14. The main shaft 1 is rotatably connected to the second housing 14 through an electromagnetic bearing 16. The stator of the electromagnetic bearing 16 is fixed on the inner wall of the second housing 14, and the rotor of the electromagnetic bearing 16 is fixed outside the main shaft 1. Both ends of the main shaft 1 penetrate the second housing 14 and extend into the vacuum chamber 15.

[0046] Two sets of second magnetohydrodynamic sealing parts 17 are provided between the outer wall of the main shaft 1 and the inner wall of the second housing 14. The two sets of second magnetohydrodynamic sealing parts 17 are used to seal the cavity inside the second housing 14 and separate the cavity inside the second housing 14 from the vacuum chamber 15.

[0047] The vacuum chamber 15 is connected to the through hole 4 inside the spindle 1.

[0048] The motor rotor 2 and flywheel 3 are both located inside the second housing 14, and the motor stator 19 is also fixed inside the second housing 14. Multiple water jacket cooling sections 18 are fixed outside the second housing 14, and the multiple water jacket cooling sections 18 are used to cool and reduce the temperature of the electromagnetic bearing 16, the second magnetohydrodynamic sealing section 17, and the motor stator 19.

[0049] By adopting the above technical solution, a dual-vacuum design is achieved. The second outer shell 14 maintains the working vacuum of the flywheel 3, while the first outer shell 13 serves as secondary protection, improving the reliability of the equipment. The electromagnetic bearing 16 enables contactless rotation, which is currently the mainstream solution for flywheel energy storage, and mature commercial products are already available. The second magnetohydrodynamic seal 17 is used for dynamic sealing when the main shaft 1 passes through the second outer shell 14. Magnetohydrodynamic sealing is also a mature technology and will not be elaborated here.

[0050] A pressure of is introduced into vacuum chamber 15. Low-pressure helium gas can enter the gap between the through hole 4 and the heat exchange rod 54 from the vacuum chamber 15. Helium gas has a high thermal conductivity and a very small molecular weight. Under low pressure, it can provide a certain heat exchange capacity. In combination with radiation heat exchange, it can improve the cooling and heat dissipation effect on the main shaft 1 and the motor rotor 2.

[0051] The water jacket cooling section 18 can cool and dissipate heat from the motor stator 19, the stator of the electromagnetic bearing 16, and the second magnetohydrodynamic sealing section 17. Water jacket cooling is the most commonly used cooling method in flywheel energy storage technology. It removes heat by circulating cold fluid in a closed pipeline. It is a mature existing technology and will not be elaborated here.

[0052] like Figure 3 and Figure 4 As shown, a spiral groove 6 is provided on the inner wall of the through hole 4, and a surface turbulence structure 7 (which can be a sharkskin-shaped structure or a herringbone groove) is integrally formed on the outer surface of the heat exchange rod 54 in the opposite direction to the spiral groove 6.

[0053] By adopting the above technical solution, in gas convection heat transfer, the laminar boundary layer close to the wall is the main source of thermal resistance. Gas molecules in this layer can only transfer heat through conduction, resulting in low efficiency. In this application, when the main shaft 1 rotates, the main shaft 1 rotates relative to the heat exchange rod 54. When the main shaft 1 rotates relative to the heat exchange rod 54, the two sets of oppositely oriented patterns of the cross-helical pattern will exert a continuous shearing effect on the low-pressure helium gas in the gap, increasing the local turbulence of the fluid, thinning the fluid retention layer near the wall, thereby improving the convection heat transfer coefficient.

[0054] When the spiral groove 6 on the inner wall of the through hole 4 rotates with the main shaft 1, it will exert an axial thrust on the helium gas, thereby achieving orderly directional convection of the helium gas, and the heat exchange effect is far better than that of disordered disturbance.

[0055] like Figures 4 to 6As shown, it also includes a drive motor 11 and a second gear 12. The output shaft of the drive motor 11 is connected to the second gear 12. The heat exchange rod 54 is externally fixed with a first gear 10 that meshes with the second gear 12. The drive motor 11 drives the heat exchange rod 54 to rotate in the through hole 4 in the opposite direction to the working direction of the main shaft 1 through the first gear 10 and the second gear 12.

[0056] The drive motor 11 is fixed to the upper end of the first housing 13, and the first gear 10 and the second gear 12 are both rotatably connected inside the first housing 13.

[0057] Multiple blades 9 are also fixed to the outside of the heat exchange rod 54. The multiple blades 9 are uniformly fixed to the outside of the heat exchange rod 54 in a circumferential array, and the blades 9 are located at the opening of the through hole 4.

[0058] By adopting the above technical solution, the drive motor 11 can drive the second gear 12 to rotate. The rotation of the second gear 12 can drive the first gear 10 and the heat exchange rod 54 to rotate in the opposite direction to the working direction of the main shaft 1. This rotation can be continuous or intermittent. For example, if the main shaft 1 rotates at a speed of... Rotating, the heat exchange rod 54 rotates at a speed of Reverse rotation, the relative shear velocity experienced by the helium gas in the gap remains at + The high-level state avoids the problem of shear force drop when rotating in the same direction, thus providing a stable turbulence-promoting effect in low-pressure helium; in low-pressure helium, both the turbulence-promoting effect and the near-wall vortex intensity are significantly enhanced, improving the cooling and heat dissipation effect.

[0059] Meanwhile, when the heat exchange rod 54 rotates in the opposite direction, it drives the blades 9 to rotate stably in the same direction. The blades 9 directly move the helium gas. Just like the working principle of an axial flow fan, the blades 9 generate a stable unidirectional pressure difference at the opening of the through hole 4, which directly drives the helium gas to form a directional circulation loop along the axial direction, improving the efficiency of gas circulation in the through hole 4 and the vacuum chamber 15, thereby improving the cooling and heat dissipation effect.

[0060] In this embodiment, by controlling the rotational speed of the drive motor (11), the reverse rotational speed of the heat exchange rod (54) is achieved. With spindle speed To satisfy specific matching relationships, the laminar flow state of low-pressure helium gas is disrupted.

[0061] Equivalent Reynolds number of the fluid in the gap It can be approximated by the following formula:

[0062]

[0063] in, To set the pressure ( The density of helium at low pressure, The outer diameter of the heat exchange rod. This refers to the clearance dimension on one side between the heat exchange rod and the inner wall of the through hole. The dynamic viscosity of helium is determined by real-time monitoring of the spindle speed. And adjust The system is forced to maintain the equivalent Reynolds number. This ensures that micro-vortex turbulent convection can still be generated and maintained under extremely low pressure conditions, significantly reducing aerodynamic thermal resistance.

[0064] like Figure 6 As shown, it also includes a liquid flow heat exchange assembly 8, which includes a hollow cavity 81 opened inside the heat exchange rod 54 and two rotary joints 82 respectively disposed at both ends of the heat exchange rod 54. The inner tubes of the two rotary joints 82 are fixedly inserted into the hollow cavity 81.

[0065] Both ends of the heat exchange rod 54 are rotatably connected to the inside of the first outer shell 13, and a first magnetic fluid sealing part 83 is provided at the rotatable connection between the heat exchange rod 54 and the first outer shell 13. The first magnetic fluid sealing part 83 seals the rotatable connection and isolates the vacuum chamber 15 inside the first outer shell 13 from the atmosphere outside the first outer shell 13.

[0066] By adopting the above technical solution, the two rotary joints 82 can be connected to an external circulating liquid supply device. Coolant can enter the hollow cavity 81 from one rotary joint 82 and then flow out back into the circulating liquid supply device from the other rotary joint 82, thereby carrying away the heat from the heat exchange rod 54 and cooling it. Since the specific heat capacity of the liquid is greater than that of the gas, the flowing coolant inside the heat exchange rod 54 can forcefully maintain the surface of the heat exchange rod 54 at a lower temperature, thus maintaining a certain temperature difference between it and the main shaft 1 and the radiant heat exchange section 51. The circulating liquid supply device can be equipped with a module for cooling the circulating coolant, achieving cooling through methods such as air cooling or semiconductor refrigeration.

[0067] Operating method: The flywheel energy storage cooling device conducts the heat generated by the motor rotor 2 to the radiative heat exchange section 51 through the heat pipe 52, and uses the centrifugal force generated by the rotation to drive the working fluid to circulate back in the inclined heat pipe 52 to achieve continuous condensation heat exchange; the heat is then radiated through the corrugated fit structure between the radiative heat exchange section 51 and the heat exchange rod 54, and at the same time, combined with the low-pressure helium gas filled in the through hole 4, the shear disturbance generated by the opposite spiral patterns on the main shaft 1 and the heat exchange rod 54 when they rotate relative to each other, and the directional convection driven by the blades 9 to break the laminar boundary layer to enhance the gas cooling heat exchange efficiency; finally, the heat is carried away by the coolant circulating in the hollow cavity 81 inside the heat exchange rod 54, and the external water jacket cooling section 18 is used to cool the motor stator 19, electromagnetic bearing 16 and magnetohydrodynamic seal, thereby achieving efficient heat dissipation of the entire device.

[0068] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A cooling device for flywheel energy storage, comprising a main shaft (1), a motor rotor (2) fixed outside the main shaft (1), and a flywheel (3), characterized in that: The spindle (1) has a through hole (4) inside, and the spindle (1) also has a built-in cooling assembly (5) inside. The built-in cooling assembly (5) includes a radiative heat exchange part (51) fixed inside the spindle (1), a through groove opened at the center of the radiative heat exchange part (51) and connected to the through hole (4), and a plurality of heat pipes (52) fixed inside the spindle (1). A heat exchange rod (54) is inserted inside the through hole (4). The heat exchange rod (54) is coaxially arranged with the through hole (4), and both ends of the heat exchange rod (54) are connected to the first outer shell (13). Multiple heat pipes (52) are evenly distributed in a circumferential array and fixed inside the main shaft (1). The upper end of the heat pipe (52) is the condensation end and is connected to the lower end of the radiation heat exchange section (51), and the lower end of the heat pipe (52) is the evaporation end. The diameter of the upper end of the heat pipe (52) is smaller than the diameter of the lower end of the heat pipe (52), so that the outer wall and the inner wall of the heat pipe (52) form a slope. A spiral groove (6) is provided on the inner wall of the through hole (4), and a surface turbulence structure (7) opposite to the direction of the spiral groove (6) is integrally formed on the outer surface of the heat exchange rod (54). It also includes a drive motor (11) and a second gear (12). The output shaft of the drive motor (11) is connected to the second gear (12). The heat exchange rod (54) is externally fixed with a first gear (10) that meshes with the second gear (12). The drive motor (11) drives the heat exchange rod (54) to rotate in the through hole (4) in the opposite direction to the working direction of the main shaft (1) through the first gear (10) and the second gear (12).

2. The cooling device for flywheel energy storage according to claim 1, characterized in that: The heat exchange rod (54) has an integrally formed corrugated flange (55) on its outside. The inner wall of the through groove inside the radiative heat exchange part (51) is provided with a corrugated groove (53). The corrugated flange (55) and the corrugated groove (53) cooperate to increase the radiative heat exchange area.

3. The cooling device for flywheel energy storage according to claim 1, characterized in that: Multiple blades (9) are also fixed to the outside of the heat exchange rod (54). The multiple blades (9) are uniformly fixed to the outside of the heat exchange rod (54) in a circumferential array, and the blades (9) are located at the opening of the through hole (4).

4. The cooling device for flywheel energy storage according to claim 3, characterized in that: It also includes a liquid flow heat exchange assembly (8), which includes a hollow cavity (81) opened inside the heat exchange rod (54) and two rotary joints (82) respectively set at both ends of the heat exchange rod (54). The inner tubes of the two rotary joints (82) are fixedly inserted into the hollow cavity (81).

5. A flywheel energy storage device, employing the cooling device described in claim 4, characterized in that: It also includes a second housing (14) disposed inside the first housing (13), a vacuum chamber (15) is formed between the first housing (13) and the second housing (14), the main shaft (1) is rotatably connected in the second housing (14) by an electromagnetic bearing (16), and both ends of the main shaft (1) pass through the second housing (14) and extend into the vacuum chamber (15); Two sets of second magnetohydrodynamic sealing parts (17) are provided between the outer wall of the main shaft (1) and the inner wall of the second outer shell (14). The two sets of second magnetohydrodynamic sealing parts (17) are used to seal the chamber inside the second outer shell (14) and separate the chamber inside the second outer shell (14) from the vacuum chamber (15). The vacuum chamber (15) is connected to the through hole (4) inside the main shaft (1).

6. A flywheel energy storage device according to claim 5, characterized in that: The motor rotor (2) and flywheel (3) are both located inside the second housing (14), and the motor stator (19) is also fixed inside the second housing (14). Multiple water jacket cooling parts (18) are fixed outside the second housing (14), and the multiple water jacket cooling parts (18) are used to cool down the electromagnetic bearing (16), the second magnetohydrodynamic sealing part (17), and the motor stator (19).

7. A flywheel energy storage device according to claim 6, characterized in that: Both ends of the heat exchange rod (54) are rotatably connected to the inside of the first outer shell (13), and a first magnetic fluid sealing part (83) is provided at the rotatable connection between the heat exchange rod (54) and the first outer shell (13). The first magnetic fluid sealing part (83) seals the rotatable connection and separates the vacuum chamber (15) inside the first outer shell (13) from the atmosphere outside the first outer shell (13).

8. A flywheel energy storage device according to claim 5, characterized in that: The drive motor (11) is fixed at the upper end of the first housing (13), and the first gear (10) and the second gear (12) are rotatably connected inside the first housing (13).

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