Flywheel rotor and flywheel energy storage system

Abstract

The invention relates to the technical field of energy storage, particularly provides a flywheel rotor and a flywheel energy storage system, and aims at solving the problem that an existing flywheel energy storage system is poor in heat dissipation performance. In order to achieve the purpose, the flywheel rotor comprises a flywheel body, a through hole is formed in the flywheel body, the two ends of the through hole communicate with the two end faces of the flywheel body correspondingly, and the axis of the through hole is not parallel to the axis of the flywheel body so that airflow can flow from one end of the through hole to the other end of the through hole when the flywheel body rotates; and the main shaft is connected with the flywheel body. The flywheel energy storage system comprises an outer shell and the flywheel rotor, the flywheel body is located in the outer shell, the main shaft extends out of the outer shell, a gap is formed between the flywheel body and the inner wall of the outer shell, the gap is filled with target gas, and when the flywheel rotor rotates, a circulation loop allowing the target gas to flow is formed between the through hole and the gap. The flywheel stored energy is cooled through self-circulation of gas, the heat dissipation performance can be effectively improved, and the system structure is simplified.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and specifically provides a flywheel rotor and a flywheel energy storage system. Background Art

[0002] Flywheel energy storage is a technology that uses a high-speed rotating flywheel to store energy. With the popularization of renewable energy and the transformation of the power system, flywheel energy storage technology has the advantages of high specific energy, high specific power, high cycle life and environmental protection compared to traditional electrochemical energy storage methods. It is currently widely used in various fields such as rail transit energy recovery, ship integrated power systems, new energy grid-connected power generation, uninterruptible power supplies, etc., providing stronger support for the construction of a new power system with new energy as the main body.

[0003] During high-speed operation, the flywheel rotor generates friction with the gas around it, which will increase the rotational resistance. Therefore, in some related technologies, the flywheel rotor is usually placed in a vacuum environment to improve the above situation. However, in a vacuum environment, the heat generated by the flywheel rotor can only be transferred to the outside world through thermal radiation, and the efficiency of heat transfer through thermal radiation is low. This will make it difficult to discharge the heat of the flywheel rotor itself in time, thereby causing the temperature of the flywheel rotor to continue to rise, affecting the operation of the system and even burning the motor.

[0004] Accordingly, the art needs a new technical solution to solve the above problems. Summary of the invention

[0005] The present application aims to solve the above technical problem, that is, to solve the problem of poor heat dissipation performance of the existing flywheel energy storage system.

[0006] In a first aspect, the present application provides a flywheel rotor, comprising:

[0007] A flywheel body, on which a through hole is formed, wherein two ends of the through hole are respectively connected to two end surfaces of the flywheel body, and an axis of the through hole is not parallel to an axis of the flywheel body, so that airflow can flow from one end of the through hole to the other end when the flywheel body rotates;

[0008] A main shaft is connected to the flywheel body.

[0009] In a technical solution of the above-mentioned flywheel rotor, a plurality of through holes are evenly distributed circumferentially around the axis of the flywheel body.

[0010] In a technical solution of the above-mentioned flywheel rotor, the axis of the through hole and the axis of the flywheel body are located in the same plane.

[0011] In a technical solution of the above-mentioned flywheel rotor, the cross-sectional area of ​​the through hole gradually decreases from its two ends to the center.

[0012] In a second aspect, the present application provides a flywheel energy storage system, comprising:

[0013] outer shell;

[0014] The flywheel rotor described in any one of the first aspects, wherein the flywheel body is located in the outer shell, the main shaft extends out of the outer shell, a gap is formed between the flywheel body and the inner wall of the outer shell, the gap is filled with a target gas, and when the flywheel rotor rotates, a circulation loop for the target gas to flow is formed between the through hole and the gap.

[0015] In a technical solution of the above-mentioned flywheel energy storage system, an auxiliary heat exchange structure is provided on the outer shell, and the auxiliary heat exchange structure is located on the flow path of the target gas.

[0016] In a technical solution of the above flywheel energy storage system, the auxiliary heat exchange structure includes:

[0017] A first fin is disposed on the inner wall of the outer shell; and / or

[0018] The second fin is arranged on the outer wall of the outer shell.

[0019] In a technical solution of the above flywheel energy storage system, the auxiliary heat exchange structure includes:

[0020] A first fin, which is arranged on the inner wall of the outer shell;

[0021] A liquid-cooled heat exchanger is arranged on the outer wall of the outer shell, and the liquid-cooled heat exchanger corresponds to the first fin, so that the first fin can exchange heat with the liquid-cooled heat exchanger.

[0022] In a technical solution of the above flywheel energy storage system, the auxiliary heat exchange structure includes:

[0023] The coil heat exchanger is arranged on the inner wall of the outer shell, and both ends of the coil heat exchanger extend out of the outer shell.

[0024] In a technical solution of the above-mentioned flywheel energy storage system, the auxiliary heat exchange structure is arranged close to the port of the through hole.

[0025] As mentioned above, when the above technical solution is adopted, after the flywheel body is installed in the outer shell of the flywheel energy storage system, the target gas is injected into the outer shell, and the target gas is filled between the gap and the through hole. When the flywheel energy storage system is running, the flywheel body rotates at high speed. Since the axis of the through hole is not parallel to the axis of the flywheel body, during the rotation process, the target gas in the through hole is subjected to the centrifugal force and moves along the through hole, thereby forming a pressure difference at both ends of the through hole. Under the action of the pressure difference, the target gas reciprocates between the through hole and the gap to form a circulating gas loop. When the target gas passes through the through hole, it can bring the heat of the flywheel body itself out to the gap, and then in the process of moving in the gap, the heat carried by the target gas can be radiated to the external environment through the outer shell, and so on. The cycle is repeated, and the cooling of the flywheel body is achieved through the circulating movement of the target gas.

[0026] This application opens a through hole on the flywheel body, and relies on the centrifugal force during the rotation of the flywheel body to drive the target gas to achieve "self-circulation" in the outer shell, without adding an external power source, which can not only reduce costs, but also simplify the composition of the flywheel energy storage system. In the prior art, if heat exchange is only carried out by radiation, the radiation intensity of the area closer to the axis of the flywheel body and the main shaft is weaker. Therefore, this application uses gas circulation to bring the heat of the flywheel body itself out to the area close to the side wall of the outer shell (i.e., the area where the gap is located), realize gas convection heat exchange, and then combine radiation to dissipate heat, thereby improving the heat dissipation performance of the flywheel energy storage system, and effectively improving the safety and stability of the operation of the flywheel energy storage system.

[0027] Furthermore, the present application arranges an auxiliary heat exchange structure on the outer shell of the flywheel energy storage system, and arranges the auxiliary heat exchange structure on the flow path of the circulating gas loop. In this way, during the gas flow process, the auxiliary heat exchange structure can further improve the heat exchange efficiency between the target gas and the external environment, thereby improving the safety and stability of the operation of the flywheel energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, in which:

[0029] Figure 1 is a schematic diagram of a flywheel energy storage system according to an embodiment of the present application;

[0030] Figure 2 is a schematic diagram of a flywheel rotor according to an embodiment of the present application;

[0031] Figure 3 is a second schematic diagram of an auxiliary heat exchange structure according to an embodiment of the present application;

[0032] Figure 4This is a third schematic diagram of an auxiliary heat exchange structure according to an embodiment of the present application.

[0033] In the figures, the reference numerals refer to the following:

[0034] 1. Outer shell; 100. Gap; 11. Stator coil; 2. Flywheel rotor; 21. Flywheel body; 211. Through hole; 212. Permanent magnet; 213. Jacket; 22. Main shaft; 3. Auxiliary heat exchange structure; 31. First fin; 32. Second fin; 33. Liquid-cooled heat exchanger. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present application are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present application and are not used to limit the scope of protection of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0036] It should be noted that in the description of this application, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description, and does not indicate or imply that the relevant devices or components must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application. In addition, the ordinal numbers "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In addition, it should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Reference Figure 1 and Figure 2 , Figure 1 is a schematic diagram of a flywheel energy storage system according to an embodiment of the present application, Figure 2 Schematic diagram of a flywheel rotor according to an embodiment of the present application.

[0039] The flywheel energy storage system includes an outer shell 1 and a flywheel rotor 2, wherein the flywheel rotor 2 includes a flywheel body 21 and a main shaft 22 fixedly connected to the flywheel body 21, wherein the main shaft 22 is coaxially arranged with the flywheel body 21, the flywheel body 21 is located in the outer shell 1, and both ends of the main shaft 22 pass through the outer shell 1, and are used to be connected to an external load in actual engineering applications. In actual processing, the flywheel body 21 and the main shaft 22 can be an integrated structure.

[0040] Reference Figure 1 and Figure 2 The flywheel body 21 is provided with a through hole 211, the two ends of the through hole 211 are respectively connected with the two end faces of the flywheel body 21, the axis of the through hole 211 is a straight line, and the axis of the through hole 211 is not parallel to the axis of the flywheel body 21. Based on this, it can be known that the axis of the through hole 211 is not parallel to the axis of the flywheel body 21 and the radial line of the flywheel body 21, and they are intersecting in space.

[0041] The interior of the outer shell 1 is a closed space, and a gap 100 is formed between the side surface of the flywheel body 21 and its two end faces and the outer shell 1, and the gap 100 is filled and sealed with a target gas. In some embodiments of the present application, the above-mentioned target gas is an inert gas, such as helium, etc. Due to the chemical stability and physical properties of inert gases such as helium, it is not easy to react chemically with other substances after filling in the gap 100, and the inert gas is also not easy to burn and explode, and has a certain thermal conductivity. Therefore, considering the above factors, these characteristics of the inert gas enable it to be used in the flywheel energy storage system. It can effectively prevent oxidation reactions inside the system and reduce fire risks, thereby ensuring the safety and stability of the operation of the flywheel energy storage system.

[0042] It should be understood that Figure 1 The diagram shown is only a schematic diagram of the flywheel energy storage system of the present application. For the flywheel energy storage system, it also includes bearings arranged between the two ends of the main shaft 22 and the outer shell 1, coil windings arranged on the outer shell 1, permanent magnets arranged on the main shaft 22 or the flywheel body 21, and necessary functional components such as power converters, which are necessary components of the flywheel energy storage system and are well-known technologies in the field, and the present application will not repeat them here. In addition, it should also be understood that the outer shell 1 may also be provided with a gas port for injecting the target gas into the interior thereof, and the gas port may be one or more. For example, after the flywheel energy storage system is assembled, before injecting the target gas into the gap 100, the interior of the outer shell 1 may be evacuated first, and then the target gas may be injected into the interior thereof.

[0043] After the target gas is injected into the outer shell 1, it fills the gap 100 and the through hole 211. When the flywheel energy storage system is running, the flywheel body 21 rotates at a high speed. Since the axis of the through hole 211 is not parallel to the axis of the flywheel body 21, during the rotation process, the target gas in the through hole 211 is subjected to the centrifugal force and moves along the through hole 211 ( Figure 1 The arrow in the middle shows the flow direction of the target gas), thereby forming a pressure difference at both ends of the through hole 211. Under the action of the pressure difference, the target gas reciprocates between the through hole 211 and the gap 100 to form a circulating gas loop. When the target gas passes through the through hole 211, it can bring the heat of the flywheel body 21 itself out to the gap 100. Then, during the movement in the gap 100, the heat carried by the target gas can be radiated to the external environment through the outer shell 1, and the reciprocating cycle is repeated to achieve cooling of the flywheel body 21 through the circulating movement of the target gas.

[0044] As mentioned above, the present application, by opening a through hole 211 on the flywheel body 21, relies on the centrifugal force during the rotation of the flywheel body 21 to drive the target gas to realize "self-circulation" in the outer shell 1, without adding an external power source, so that it can not only achieve a cost reduction effect, but also simplify the composition of the flywheel energy storage system. In the prior art, if heat exchange is only carried out by radiation, then the closer the area is to the axis of the flywheel body 21 and the main shaft 22, the weaker the radiation intensity. Therefore, the present application uses gas circulation to bring the heat of the flywheel body 21 itself out to the area close to the side wall of the outer shell 1 (i.e., the area where the gap 100 is located), realizes gas convection heat exchange, and then combines radiation to dissipate heat, thereby improving the heat dissipation performance of the flywheel energy storage system, and effectively improving the safety and stability of the operation of the flywheel energy storage system.

[0045] In this application Figure 1 In the example given, the flywheel body 21 also includes a permanent magnet 212 arranged along its circumference and a sheath 213 arranged on the side surface of the flywheel body 21. The stator coil 11 is arranged on the side wall of the outer shell 1, so that energy conversion is achieved through the cooperation of the stator coil 11 and the permanent magnet 212, and the sheath 213 fixes and protects the permanent magnet 212. It should be noted that although the above-mentioned method of the present application is illustrated by taking the permanent magnet flywheel energy storage motor as an example, it does not constitute a limitation to the present application, that is, the flywheel body 21 of the present application can be applied to other forms of flywheel energy storage systems, as long as there is a gap between the flywheel body 21 and the outer shell of the flywheel energy storage system, so that a circulating gas loop can be formed between the gap and the through hole of the flywheel body 21.

[0046] Reference Figure 1 and Figure 2In one embodiment of the present application, a plurality of through holes 211 are evenly distributed circumferentially around the axis of the flywheel body 21, and the axis of each through hole 211 and the axis of the flywheel body 21 are located in the same plane.

[0047] There are multiple through holes 211 evenly distributed around the circumference, on the one hand, in order to increase the number of gas circulation loops, thereby increasing the heat exchange area between the target gas and the flywheel body 21, and making the convective heat exchange more efficient. On the other hand, since the structural feature of the flywheel body 21 is cylindrical or disc-shaped, the multiple through holes 211 are evenly distributed around the circumference of the flywheel body 21, which is conducive to maintaining the dynamic balance of the flywheel body 21 during rotation, thereby ensuring the stability of the operation of the flywheel energy storage system.

[0048] In addition, the axis of the through hole 211 is in the same plane as the axis of the flywheel body 21, that is, in the axial section of the flywheel body 21. This is not only conducive to the processing of the through hole 211, but also reduces the length of the through hole 211 to the maximum extent on the basis of increasing the centrifugal force, shortens the gas flow path, and reduces the rotation resistance and friction heat generated by repeated collision and friction between the target gas and the inner wall of the through hole 211.

[0049] The inclination angle of the axis of the through hole 211 relative to the axis of the flywheel body 21 can be determined according to the size of the flywheel body 21 itself. For example, when the flywheel body 21 is "disk-shaped" as a whole, the axis of the through hole 211 can be relatively more inclined relative to the axis of the flywheel body 21, and when the flywheel body 21 is an elongated "columnar" as a whole, the angle between the axis of the through hole 211 and the axis of the flywheel body 21 is naturally smaller. In practical applications, the angle between the axis of the through hole 211 and the axis of the flywheel body 21 can be determined comprehensively in combination with the structure of the flywheel body 21 itself and various factors such as wind resistance and centrifugal force. It should be noted that, theoretically, when the angle between the axis of the through hole 211 and the axis of the flywheel body 21 is too small, it will lead to insufficient centrifugal force, which is not conducive to forming a circulating gas loop in the outer shell 1. When the angle between the axis of the through hole 211 and the axis of the flywheel body 21 is too large, not only is the processing difficult and the gas circulation path too long, but it is also not conducive to the overall structural stiffness of the flywheel body 21. Therefore, under the premise that the structural size of the flywheel body 21 itself allows, the angle between the axis of the through hole 211 and the axis of the flywheel body 21 can be set at about 45°.

[0050] Of course, the above method is only an optional method of the present application and is not a limitation of the present application. For example, in some other implementation methods, the through hole 211 may not extend along the axial section of the flywheel body 21, or the through hole 211 may also be other irregular curved shapes, as long as the flywheel body 21 can generate centrifugal force on the target gas in the through hole 211 while rotating, thereby generating a pressure difference at both ends of the through hole 211.

[0051] Reference Figure 1 and Figure 2 In one embodiment of the present application, the cross-sectional area of ​​the through hole 211 gradually decreases from its two ends to the center, so that the overall structure of the through hole 211 is in the shape of a "Laval tube".

[0052] During the operation of the flywheel energy storage system, the rotation speed of the flywheel rotor 2 can reach 40,000 to 50,000 r / min. This high-speed condition is not conducive to the circulation of the target gas (when the flywheel body 21 operates at a high speed, the airflow near its two end faces will move along the rotation direction of the flywheel body 21, thereby causing resistance to the process of the target gas entering and exiting the through hole 211). In the present application, by setting the through hole 211 to the above-mentioned "Laval tube" structure, the cross-sectional area of ​​the air inlet of the through hole 211 is increased, which is conducive to the entry of the target gas. At the same time, the flow rate of the target gas continues to increase during the process of passing through the contraction section and the expansion section of the through hole 211, so that the target gas can be quickly discharged from the exhaust port of the through hole 211. When the air pressure on the exhaust side of the through hole 211 increases, the target gas will naturally be prompted to enter the air inlet of the through hole 211. Thus, by setting the cross-sectional area of ​​the through hole 211 as described above, not only can the flow rate of the gas in the circulating gas loop be accelerated, thereby improving the heat exchange efficiency, but also the friction loss between the gas and the through hole 211 and the wind resistance can be reduced.

[0053] It should be noted that the cross section of the through hole 211 gradually decreases from both ends to the "center", and the "center" here is not limited to the geometric center of the length of the through hole 211, and can be any position between the air inlet and the exhaust port of the through hole 211 (the "center" position is also the "throat" of the "Laval tube"), and can be adjusted based on actual needs in practical applications. In addition, the cross section of the through hole 211 in the present application can be circular or rectangular, etc., and the present application does not limit it.

[0054] In a possible implementation of the present application, an auxiliary heat exchange structure 3 is further provided on the outer shell 1. The auxiliary heat exchange structure 3 is located on the flow path of the target gas. The auxiliary heat exchange structure 3 enhances the heat exchange efficiency between the target gas and the external environment.

[0055] Reference Figure 1In one embodiment, the auxiliary heat exchange structure 3 includes a first fin 31 and a second fin 32. The first fin 31 and the second fin 32 can be made of a material with high thermal conductivity, such as a metal material. The first fin 31 is fixedly arranged on the inner wall of the outer shell 1, and the second fin 32 is fixedly arranged on the outer wall of the outer shell 1. The first fin 31 increases the contact area between the first fin 31 and the target gas, so that the first fin 31 can transfer the heat carried by the target gas to the outer shell 1 more quickly, and then the outer shell 1 radiates the heat to the external environment; the second fin 32 is fixedly arranged on the outer wall of the outer shell 1. The heat dissipation principle of the second fin 32 is similar to that of radiators, heat dissipation fins in the chemical industry, etc., which is a well-known technology in the field and will not be elaborated in this application.

[0056] It should be noted that, in practical applications, only the first fin 31 or the second fin 32 may be provided, or both the first fin 31 and the second fin 32 may be provided. When the first fin 31 and the second fin 32 exist at the same time, the second fin 32 may be provided corresponding to the first fin 31, so that the heat of the first fin 31 can be quickly transferred to the second fin 32, so as to further improve the heat dissipation efficiency.

[0057] Reference Figure 3 In another embodiment, the second fin 32 can be replaced by a liquid-cooled heat exchanger 33, that is, the auxiliary heat exchange structure 3 includes a first fin 31 arranged on the inner wall of the outer shell 1 and a liquid-cooled heat exchanger 33 arranged on the outer wall of the outer shell 1, and the liquid-cooled heat exchanger 33 corresponds to the first fin 31. The liquid-cooled heat exchanger 33 is a forced circulation cooling method. The shell or coil of the liquid-cooled heat exchanger 33 is in contact with the outer wall of the outer shell 1, and a cooling medium with a large specific heat capacity such as water is introduced therein. The cooling medium circulates with an external power source to take away the heat from the outer shell 1. The liquid-cooled heat exchanger 33 can only cover the corresponding position of the first fin 31 according to needs, or it can be laid along the outer wall of the outer shell 1, and this can be adaptively adjusted according to the situation.

[0058] Reference Figure 4 In another embodiment, the auxiliary heat exchange structure 3 can be a coil radiator arranged on the inner wall of the outer shell 1. The coil radiator can be arranged in a spiral manner along the inner wall of the outer shell 1, or it can be composed of a plurality of vertical pipes arranged side by side along the circumference of the inner wall of the outer shell 1. The plurality of vertical pipes can be connected in a serpentine manner, or a converging pipe vertically connected to the upper and lower ends of the vertical pipes can be respectively arranged. The present application does not limit the specific structural form of the coil radiator. The interior of the coil radiator also has a cooling medium. The inlet and outlet ends of the coil radiator respectively pass through the outer shell 1 and are sealed and connected to the outer shell 1.

[0059] In specific applications, the coil-type radiator can use the above-mentioned forced circulation method to dissipate heat. At this time, the cooling medium inside it can be liquid such as water, and its heat dissipation principle is the above-mentioned "liquid cooling" method. In some other methods, the cooling medium inside the coil-type radiator can also be a phase change material, relying on the pressure difference generated during the phase change process of the phase change material when heated to achieve self-circulation of the cooling medium. This method does not require the setting of an external power source. In short, the structural form and cooling principle of the coil-type radiator can be determined according to actual needs.

[0060] As mentioned above, although a coil-type radiator is arranged inside the outer shell 1, it will occupy a part of the internal space of the outer shell 1, but the target gas directly exchanges heat with the cooling medium in the coil-type radiator during the circulation process, which is conducive to quickly taking away the heat carried by the target gas, and the coil-type radiator can increase the contact area between the target gas and the target gas, which is conducive to further improving the heat dissipation efficiency.

[0061] Finally, it should be noted that in some implementations of the present application, the auxiliary heat exchange structure 3 can be set at a position close to the port of the through hole 211. For example, according to the circulation direction of the gas, the auxiliary heat exchange structure 3 can be set at a position close to the exhaust port of the through hole 211, so that the target gas is discharged from the through hole 211 and directly blown to the surface of the auxiliary heat exchange structure 3, thereby maximizing the role of the auxiliary heat exchange structure 3.

[0062] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. A flywheel rotor, characterized in that: include: A flywheel body, on which a through hole is formed, wherein two ends of the through hole are respectively connected to two end surfaces of the flywheel body, and an axis of the through hole is not parallel to an axis of the flywheel body, so that airflow can flow from one end of the through hole to the other end when the flywheel body rotates; A main shaft is connected to the flywheel body.

2. The flywheel rotor according to claim 1, characterized in that: A plurality of through holes are evenly distributed circumferentially around the axis of the flywheel body.

3. The flywheel rotor according to claim 2, characterized in that: The axis of the through hole and the axis of the flywheel body are located in the same plane.

4. The flywheel rotor according to any one of claims 1 to 3, characterized in that: The cross-sectional area of ​​the through hole gradually decreases from both ends to the center.

5. A flywheel energy storage system, characterized in that: include: outer shell; The flywheel rotor according to any one of claims 1 to 4, wherein the flywheel body is located in the outer shell, the main shaft extends out of the outer shell, a gap is formed between the flywheel body and the inner wall of the outer shell, the gap is filled with a target gas, and when the flywheel rotor rotates, a circulation loop for the target gas to flow is formed between the through hole and the gap.

6. The flywheel energy storage system according to claim 5, characterized in that: An auxiliary heat exchange structure is arranged on the outer shell, and the auxiliary heat exchange structure is located on the flow path of the target gas.

7. The flywheel energy storage system according to claim 6, characterized in that: The auxiliary heat exchange structure comprises: A first fin is disposed on the inner wall of the outer shell; and / or The second fin is arranged on the outer wall of the outer shell.

8. The flywheel energy storage system according to claim 6, characterized in that: The auxiliary heat exchange structure comprises: A first fin, which is arranged on the inner wall of the outer shell; A liquid-cooled heat exchanger is arranged on the outer wall of the outer shell, and the liquid-cooled heat exchanger corresponds to the first fin, so that the first fin can exchange heat with the liquid-cooled heat exchanger.

9. The flywheel energy storage system according to claim 6, characterized in that: The auxiliary heat exchange structure comprises: The coil heat exchanger is arranged on the inner wall of the outer shell, and both ends of the coil heat exchanger extend out of the outer shell.

10. The flywheel energy storage system according to any one of claims 6 to 9, characterized in that: The auxiliary heat exchange structure is arranged close to the port of the through hole.

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