Cooling device of flywheel energy storage motor rotor and flywheel energy storage motor

Abstract

The invention provides a cooling device of a flywheel energy storage motor rotor and a flywheel energy storage motor, and the cooling device comprises a flywheel housing which is internally provided with a cavity; the flywheel rotor extends into the cavity, one end of a shaft of the flywheel rotor extends out of the flywheel shell, the cavity is sealed through a preset device to form a vacuum sealing cavity, a cooling groove is formed in a center shaft of the flywheel rotor, and the axial length of the cooling groove extends to a preset position from the top, extending out of the vacuum cavity, of the flywheel rotor; the motor rotor is arranged on the side wall of the flywheel rotor, is coaxial with the flywheel rotor and is positioned in the range of the axial length of the cooling groove; and the cooling pipeline is inserted into the cooling groove of the flywheel rotor and is used for conveying a cooling medium to the cooling groove so as to cool the motor rotor of the flywheel. According to the invention, the cooling medium directly cools the motor rotor of the flywheel through the cooling pipeline.

Description

Technical Field

[0001] This application relates to the field of flywheel energy storage technology, and more specifically, to a cooling device for the rotor of a flywheel energy storage motor and a flywheel energy storage motor. Background Technology

[0002] Currently, with the rapid development of new energy and high-end equipment manufacturing, the demand for instantaneous high-power, high-frequency energy storage technology in power grids is becoming increasingly urgent. Flywheel energy storage technology, with its advantages of fast response, long cycle life, and environmental friendliness, is widely used in areas such as power grid frequency regulation and power quality improvement. However, the core component of flywheel energy storage devices—the flywheel rotor—usually operates within a vacuum chamber to reduce windage losses. This also means that the heat generated by the motor rotor can only be slowly dissipated through thermal radiation. Especially in permanent magnet motors, the increased rotor temperature may cause irreversible demagnetization of the permanent magnets, severely restricting system reliability.

[0003] To address the heat dissipation challenge of motor rotors, existing technologies have proposed helium-fluidized cooling or spatial isolation solutions. Magnetohydrodynamic (MHD) seals are used to isolate the motor cavity from the flywheel energy storage cavity, but they have significant drawbacks in practical applications: when applied to megawatt-class high-power flywheels, the large shaft diameter of the MHD seal structure leads to excessively high linear velocities at the location of the MHD fluid, causing severe overheating and even seal failure. Simultaneously, increasing the motor cavity pressure to enhance heat dissipation significantly increases the windage losses of the motor rotor, creating a contradiction between heat dissipation efficiency and mechanical losses. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a cooling device for the rotor of a flywheel energy storage motor and a flywheel energy storage motor, so as to overcome at least one of the above-mentioned defects.

[0005] In a first aspect, embodiments of this application provide a cooling device for a flywheel energy storage motor rotor. The cooling device includes: a flywheel housing, the interior of which forms a first cavity; a flywheel rotor, extending into the interior of the first cavity, with one end of the flywheel rotor shaft extending out of the flywheel housing; a pre-set device sealing the cavity to form a vacuum-sealed cavity; a cooling groove disposed within the central shaft of the flywheel rotor, the axial length of which extends from the top of the flywheel rotor extending out of the vacuum cavity to a pre-set position; a motor rotor disposed on the side wall of the flywheel rotor, coaxial with the flywheel rotor, and located within the axial length of the cooling groove; and a cooling pipe inserted into the cooling groove of the flywheel rotor for supplying a cooling medium to the cooling groove to cool the motor rotor of the flywheel. In one optional embodiment of this application, the cooling device further includes a magnetohydrodynamic seal, wherein the magnetohydrodynamic seal is installed in the area where the flywheel rotor extends out of the housing and is fixedly connected to the flywheel housing to isolate the vacuum environment inside the flywheel housing from the external environment.

[0006] In one optional embodiment of this application, the portion of the cooling pipe extending into the cooling tank is provided with multiple radially penetrating through holes for radially ejecting the cooling medium and exchanging heat with the inner wall of the cooling tank via convection.

[0007] In one optional embodiment of this application, the cooling device further includes a return shroud, wherein the return shroud is fixed to the flywheel housing and covers the protruding end of the flywheel rotor, for collecting the cooling medium after convective heat exchange in the cooling tank.

[0008] In one optional embodiment of this application, the magnetic fluid seal includes a base, magnetic poles, a magnetic ring, and magnetic fluid. The base is fixedly connected to the flywheel housing and forms a second cavity with the outer wall of the flywheel rotor. The magnetic ring and magnetic poles are both disposed in the second cavity. The magnetic fluid fills the gap between the magnetic poles and the flywheel rotor. The sealing position of the magnetic fluid seal is located at the shaft extension end with the smallest diameter of the flywheel rotor, and a sealing ring is formed by the magnetic fluid under the action of a magnetic field.

[0009] In one alternative embodiment of this application, the cooling medium is isolated from the medium of the magnetohydrodynamic seal.

[0010] In one optional embodiment of this application, the cooling device further includes a closed-loop structure, wherein one end of the closed-loop structure is connected to the cooling pipeline, and the other end of the closed-loop structure is connected to the return shroud for circulating cooling of the cooling medium.

[0011] In one alternative embodiment of this application, the cooling tank inlet is exposed to the external environment so that the cooling device dissipates heat through convection.

[0012] In one alternative embodiment of this application, the cooling pipes inserted into the cooling groove of the flywheel rotor have no mechanical contact with the flywheel rotor.

[0013] Secondly, embodiments of this application also provide a flywheel energy storage motor, the flywheel energy storage motor including a cooling device for the rotor of the flywheel energy storage motor as described in any of the preceding claims. This application provides a cooling device for a flywheel energy storage motor rotor and a flywheel energy storage motor. The cooling device includes: a flywheel housing with a cavity inside; a flywheel rotor extending into the cavity, with one end of the rotor shaft extending out of the flywheel housing; a pre-set device sealing the cavity to form a vacuum-sealed cavity; a cooling groove disposed within the central shaft of the flywheel rotor, the axial length of which extends from the top of the flywheel rotor extending out of the vacuum cavity to a pre-set position; a motor rotor disposed on the side wall of the flywheel rotor, coaxial with the flywheel rotor, and located within the axial length of the cooling groove; and cooling pipes inserted into the cooling groove of the flywheel rotor for supplying cooling medium to the cooling groove to cool the flywheel motor rotor. This application allows the cooling medium to directly cool the flywheel motor rotor via the cooling pipes.

[0014] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure in the prior art provided in the embodiments of this application; Figure 2 This is a schematic diagram of the cooling device for the rotor of the flywheel energy storage motor provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the magnetohydrodynamic seal provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the first embodiment provided in this application. Figure 5 This is a schematic diagram of the structure of the second embodiment provided in this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0018] First, the applicable application scenarios of this application will be introduced. This application can be applied to the field of flywheel energy storage technology.

[0019] Research has revealed that with the increasing proportion of new energy sources and the development of high-end equipment manufacturing, higher requirements are being placed on power quality at the grid, transmission and distribution, and user sides. Flywheel energy storage features instantaneous high power, short-duration high frequency, safety without attenuation, and environmental friendliness, and its application scenarios are constantly expanding. To reduce the mechanical losses of flywheel energy storage devices, the flywheel rotor needs to operate within a vacuum chamber, thereby reducing wind friction losses and improving the flywheel's operating efficiency.

[0020] Regardless of the type of flywheel motor used, such as induction motor, permanent magnet motor, or reluctance motor, its rotor will inevitably experience losses, leading to heat generation. Since the motor rotor and flywheel rotor are directly connected and both operate within a vacuum chamber, the heat generated by the motor rotor losses is dissipated solely through thermal radiation, resulting in low heat dissipation efficiency. This can easily cause the motor rotor temperature to rise continuously, even exceeding the temperature resistance requirements of the relevant materials. This is especially true for permanent magnet motors, where permanent magnets have relatively low temperature resistance requirements. Exceeding the temperature limit will cause irreversible demagnetization of the permanent magnets, rendering the flywheel unable to function.

[0021] For an example, please refer to Figure 1 , Figure 1 The diagram below shows the structure of the prior art provided in the embodiments of this application. See application number 202211294602.3. Although the solution in this patent can spatially isolate the motor from the flywheel energy storage unit, the position of the seal 3 is complex and difficult to implement in engineering applications. Furthermore, the installation position of the seal 3 results in a relatively large outer diameter, a relatively large linear velocity at the same rotational speed, and more severe heat generation at the sealing position.

[0022] Magnetofluid sealing structures have certain limitations on the rotational linear velocity of the magnetofluid. When the flywheel speed is high and the flywheel power and capacity are both large, the magnetofluid in the magnetofluid sealing structure will generate severe heat, which will lead to seal failure. At the same time, the outer surface of the motor rotor side is in a high-pressure environment, and its windage loss is large at high speed, which will have an adverse effect on the overall efficiency of the flywheel.

[0023] Figure 1 The reference numerals in the attached drawings are as follows: housing 1; first housing 11; second housing 12; air outlet 121; air inlet 122; cooling channel 123; guide groove 1231; protrusion 1232; sealing ring 1233; guide part 1234; flywheel 2; wheel axle part 21; rotor part 22; sealing assembly 3; annular part 31; magnetic ring 311; annular flange 3111; magnetic shielding ring 312; rotor 41; stator 42.

[0024] Based on this, the present application provides a cooling device for a flywheel energy storage motor rotor and a flywheel energy storage motor. By providing a cooling groove on the central shaft of the flywheel rotor and inserting a cooling pipe to transport the cooling medium, the motor rotor, which is located on the side wall of the flywheel rotor and within the axial length range of the cooling groove, is directly cooled.

[0025] Please see Figure 2 , Figure 2 This is a schematic diagram of the cooling device for the rotor of the flywheel energy storage motor provided in an embodiment of this application. Figure 2 As shown in the figure, the cooling device for the flywheel energy storage motor rotor provided in this application embodiment includes a flywheel housing 52, a flywheel rotor 54, a motor rotor 57, and a cooling pipe 55.

[0026] Specifically, a first cavity is formed inside the flywheel housing 52; The flywheel rotor 54 extends into the interior of the first cavity, and one end of the shaft of the flywheel rotor 54 extends out of the flywheel housing. The cavity is sealed by a preset device to form a vacuum-sealed cavity. A cooling groove 513 is provided in the central shaft of the flywheel rotor 54. The axial length of the cooling groove 513 extends from the top of the flywheel rotor 54 extending out of the vacuum cavity to a preset position. Preferably, the motor rotor and flywheel rotor are integrated into a single structure, that is, the disc structure and the motor rotor are coaxially and directly connected. In an optional embodiment, some may use separate parts and fasten them with bolts to form a single direct connection structure. However, regardless of the solution, the final result is that the motor rotor and the flywheel rotor disc are directly connected together, with two shafts extending from both ends to support and connect with bearings.

[0027] The motor rotor 57 is mounted on the side wall of the flywheel rotor 54, coaxial with the flywheel rotor 54, and located within the axial length of the cooling tank 513; Cooling pipe 55 is inserted into the cooling tank of flywheel rotor 54 to deliver cooling medium to cooling tank 513 to cool the motor rotor 57 of flywheel.

[0028] Preferably, the portion of the cooling pipe 55 extending into the cooling tank 513 is provided with multiple radially penetrating through holes for radially ejecting the cooling medium and exchanging heat with the inner wall of the cooling tank through convection. The cooling pipe 55 has multiple holes at the part that extends into the cooling tank of the flywheel rotor 54, so that the cooling medium flows out from the cooling pipe 55 and exchanges heat with the surface of the cooling tank of the flywheel rotor 54 through convection.

[0029] The cooling pipes have small vent holes at the part where they extend into the flywheel rotor cooling tank, but this structural detail is one specific implementation example, and structures without small vent holes are also within the scope of protection of this application.

[0030] For example, the cooling pipe 55 inserted into the cooling slot 513 of the flywheel rotor 54 has no mechanical contact with the flywheel rotor 54.

[0031] In an alternative embodiment, the cooling medium is isolated from the medium of the magnetohydrodynamic seal.

[0032] Specifically, in this application, the cooling medium can be air or Freon, etc. When selecting the cooling medium, it is necessary to consider that the cooling medium may cause the magnetic fluid medium seal to fail.

[0033] Preferably, the cooling tank inlet is exposed to the external environment so that the cooling device dissipates heat through convection.

[0034] The flywheel housing and flywheel rotor of this application form a vacuum-sealed cavity, providing a relatively stable and protected operating environment for the flywheel energy storage motor rotor. This reduces interference from external factors on internal components and helps improve the overall operational reliability. By setting a cooling groove on the central shaft of the flywheel rotor and placing the motor rotor within the axial length of the cooling groove, and by having cooling pipes deliver cooling medium to the cooling groove, the motor rotor can be directly cooled. This design allows the cooling medium to act precisely on the parts of the motor rotor that need cooling, effectively removing the heat generated by the motor rotor during operation. This prevents the motor rotor from being affected by overheating, thus ensuring that the flywheel energy storage motor operates efficiently and stably at a suitable temperature. Furthermore, the layout and arrangement of the components in this application make full use of space, achieving the cooling function while maintaining the compactness of the overall structure, which is conducive to the miniaturization and integration of flywheel energy storage devices.

[0035] like Figure 2The cooling device also includes a magnetic fluid seal 51, which is installed in the area where the flywheel rotor 54 extends out of the housing and is fixedly connected to the flywheel housing 52 to isolate the vacuum environment inside the flywheel housing 52 from the external environment.

[0036] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of the magnetohydrodynamic seal provided in the embodiments of this application.

[0037] Figure 3 In this process, the magnetic fluid seal 51 includes a base 511, a magnetic pole 58, a magnetic ring 59, and a magnetic fluid 512. The base 511 is fixedly connected to the flywheel housing 52 and forms a second cavity with the outer wall of the flywheel rotor 54. The magnetic ring 59 and the magnetic pole 58 are both disposed in the second cavity. The magnetic fluid 512 fills the gap between the magnetic pole 58 and the flywheel rotor 54. The sealing position of the magnetic fluid seal 51 is located at the shaft extension end with the smallest diameter of the flywheel rotor 54, and a sealing ring is formed by the magnetic fluid under the action of a magnetic field.

[0038] This application does not describe the heat dissipation method of the magnetohydrodynamic seal. In actual use, a water cooling solution can be adopted.

[0039] The magnetohydrodynamic seal 51 physically isolates the inside of the flywheel housing 52 from the external environment of the flywheel. The inner cavity of the flywheel housing is evacuated to a vacuum environment by the vacuum system, and the flywheel rotor 54 operates mostly in a vacuum environment, reducing wind friction loss. The part of the flywheel rotor 54 that extends out of the magnetohydrodynamic seal 51 and the cooling groove of the flywheel rotor are in the external environment, allowing it to operate in an atmospheric environment. Since the diameter and length of the protruding shaft head of the flywheel rotor 54 are small, and the diameter of the cooling groove is even smaller, even if the operating speed of the flywheel rotor 54 is high, the wind friction loss will be small.

[0040] When the flywheel energy storage device is working normally, the flywheel motor rotor 57 will generate heat due to losses. As its temperature rises, a temperature difference is formed between the surface of the cooling tank of the flywheel motor rotor 57 and the surface of the cooling tank of the flywheel rotor 54, so that the heat generated by the flywheel motor rotor 57 is transferred to the surface of the cooling tank of the flywheel rotor 54. The cooling pipe 55 sends the cooling medium into the internal environment of the cooling tank of the flywheel rotor 54, and the cooling medium and the surface of the cooling tank of the flywheel rotor 54 generate convective heat transfer, reducing the temperature of the flywheel rotor 54. After convective heat transfer, the cooling medium returns to the end of the cooling tank of the flywheel rotor 54, and is then collected by the return shroud 56 and sent to a designated location.

[0041] Specifically, the base 511 serves as the basic support component of the magnetohydrodynamic seal 51. It is fixedly connected to the flywheel housing 52 and together with the outer wall of the flywheel rotor 54, forms the second cavity. The material of the base 511 typically possesses sufficient strength and stability to ensure that it can provide a reliable mounting base for other components during the entire operation of the device, while also ensuring the sealing of the second cavity.

[0042] Both the magnetic guide ring 59 and the magnetic pole 58 are disposed within the second cavity. The magnetic guide ring 59 guides the distribution of the magnetic field, enhancing its strength and uniformity; the magnetic pole 58 plays a crucial role in establishing the magnetic field, working in conjunction with the magnetic guide ring 59 to create a specific magnetic field environment in the sealed area. Their installation positions and relative relationships are carefully designed to ensure a reasonable distribution of the magnetic field, thereby providing conditions for the magnetic fluid 512 to form an effective sealing ring.

[0043] Magnetorheological fluid 512 fills the gap between magnetic pole 58 and flywheel rotor 54. Magnetorheological fluid 512 is a special fluid that has unique physical properties under the influence of a magnetic field, and can form a stable "liquid O-ring" in the gap, thus playing a sealing role.

[0044] The cooling device also includes a return shroud 56, which is fixed to the flywheel housing 52 and covers the protruding end of the flywheel rotor 54, and is used to collect the cooling medium after convective heat exchange through the cooling tank 513.

[0045] Specifically, the return shroud 56 is fixedly mounted on the flywheel housing 52, precisely covering the protruding end of the flywheel rotor 54. In terms of shape, it is typically designed as a shroud-like structure adapted to the protruding end of the flywheel rotor, completely enclosing the area to ensure effective collection of the cooling medium. Regarding materials, materials with sufficient strength and corrosion resistance are generally selected to suit the operating environment of the flywheel energy storage device.

[0046] This application can efficiently collect the cooling medium after convective heat exchange in the cooling tank 513, prevent the cooling medium from flowing or being lost at will, ensure that the cooling medium can be centrally processed or recycled, improve the utilization rate of the cooling medium, and prevent the cooling medium from spreading disorderly inside the device, preventing it from corroding or interfering with other components, maintaining the stability and cleanliness of the internal environment of the flywheel energy storage motor rotor cooling device, which is conducive to the long-term stable operation of the device.

[0047] The cooling device also includes a closed-loop structure, wherein one end of the closed-loop structure is connected to the cooling pipe and the other end of the closed-loop structure is connected to the return shroud for circulating cooling of the cooling medium.

[0048] In an optional embodiment, a closed-loop structure can be added between the cooling pipe 55 and the return shroud 56 to achieve closed-loop circulation of the cooling medium.

[0049] Examples include components such as pipes, valves, and pumps. Pipes need to have good sealing properties and resistance to media corrosion to ensure that the cooling medium does not leak during circulation; valves are used to control the flow rate and direction of the cooling medium; pumps provide power for the circulation of the cooling medium to ensure its continuous flow.

[0050] The closed-loop structure allows the cooling medium to circulate continuously within the system comprised of cooling pipes, cooling tanks, a return shroud, and the closed-loop structure itself. After cooling the motor rotor in the cooling tank, the cooling medium is guided to a suitable location for further cooling through the closed-loop structure, and then reintroduced into the cooling pipes to continue cooling the motor rotor, forming a continuous cooling cycle.

[0051] This application provides a cooling device for a flywheel energy storage motor rotor and a flywheel energy storage motor. The cooling device includes: a flywheel housing with a cavity formed inside; a flywheel rotor extending into the cavity, with one end of the rotor's shaft extending out of the flywheel housing; a pre-set device sealing the cavity to form a vacuum-sealed cavity; a cooling groove disposed within the central shaft of the flywheel rotor, the axial length of which extends from the top of the flywheel rotor extending out of the vacuum cavity to a pre-set position; a motor rotor disposed on the side wall of the flywheel rotor, coaxial with the flywheel rotor, and located within the axial length of the cooling groove; and cooling pipes inserted into the cooling groove of the flywheel rotor for supplying cooling medium to the cooling groove to cool the flywheel motor rotor. This application allows the cooling medium to directly cool the flywheel motor rotor via the cooling pipes.

[0052] In conventional flywheel energy storage devices, where the motor rotor 57 and flywheel rotor 54 are directly connected in a disc structure, the central shaft at one end is lengthened and extends beyond the flywheel housing. A magnetohydrodynamic seal is installed at this extended shaft location to effectively seal the inside of the flywheel housing. The flywheel rotor shaft has a cooling groove that extends from the extended shaft end to the shaft containing the motor rotor 57, covering the entire area of ​​the motor rotor 57. An external cooling pipe is inserted into the cooling groove of the shaft, extending to the depth of the groove. This cooling pipe does not directly contact the flywheel rotor shaft; it can be fixed to the flywheel housing or fixed in other ways to maintain a static relationship with the flywheel housing while possessing sufficient strength to prevent collisions with the flywheel rotor shaft. During normal operation, cooling gas flows through the cooling pipe to cool the grooves of the flywheel rotor shaft. Heat generated by the motor rotor due to losses flows to the surface of the flywheel rotor shaft grooves via heat conduction, and is then dissipated to the outside by convection through the cooling medium supplied by the cooling pipe. To prevent the cooling medium in the cooling pipes from forming a high-temperature medium after convective heat exchange with the flywheel rotor shaft and being directly discharged into the flywheel's installation environment, a return shroud structure can be installed on the flywheel housing at the end of the flywheel rotor shaft's cooling slot to collect the heat and send it to a designated location. Because the magnetohydrodynamic seal structure isolates the internal space of the flywheel housing from the cooling circulation space of the flywheel rotor shaft, a vacuum environment can be achieved inside the flywheel housing, while the cooling slot of the flywheel rotor is not in a vacuum environment. Due to the different pressure difference, conventional heat dissipation methods can be more effectively employed.

[0053] One end of the flywheel rotor 54 with a cooling groove extends out of the flywheel housing 52. A magnetohydrodynamic seal 51 is installed on one side of the extended end of the flywheel rotor 54 and is fixedly connected to the flywheel housing 52. The magnetohydrodynamic seal 51 spatially isolates the inside and outside of the flywheel housing 52. A cooling pipe 55 is inserted into the cooling groove of the flywheel rotor 54. At the same time, the cooling pipe 55 has no mechanical contact with the cooling groove of the flywheel rotor 54. A return shroud 56 is installed on the extended side of the flywheel rotor 54 shaft to achieve cooling and collection of convective heat.

[0054] In one alternative embodiment, the motor rotor 57 of the flywheel is located above the disc portion of the flywheel rotor 54. However, the cooling structure is not limited to this layout and can also be applied to a layout in which the motor rotor 57 is located below the disc portion of the flywheel rotor 54. In this application, the cooling groove of the flywheel rotor 54 needs to be extended to the location of the motor rotor 57, which is not directly related to the relative position of the flywheel motor rotor.

[0055] This application can enhance the efficiency of traditional flywheel motor rotors that rely solely on thermal radiation for heat dissipation in a vacuum environment; the magnetofluid seal 51 is installed at one end of the flywheel rotor 54, which can more easily reduce the diameter of the shaft part in contact with the magnetofluid, greatly reduce the heat generation of the magnetofluid, and reduce engineering difficulty and cost; it can place most of the structure of the flywheel rotor 54 in a vacuum environment with a sealed space to the greatest extent, minimize the wind friction loss of the flywheel rotor 54 caused by high speed, and greatly improve the flywheel operating efficiency on the basis of improving the rotor heat dissipation efficiency.

[0056] The upper end of the flywheel rotor in this application extends out of the flywheel housing and is dynamically sealed using a magnetohydrodynamic seal to seal the space within the flywheel housing. Simultaneously, an elongated hole is provided at the center of the flywheel rotor, extending to the location of the flywheel motor rotor (installed at one end of the flywheel rotor shaft, which can significantly reduce the diameter of the shaft to be sealed and reduce the heat generated by the magnetohydrodynamic fluid). Cooling pipes are inserted into the cooling grooves of the flywheel rotor, but there is no mechanical contact between the cooling pipes and the flywheel rotor. A return shroud is provided on the upper part of the flywheel housing to collect the heat-exchanged working fluid and send it to a designated location. The cooling medium can be air or Freon, etc. The external circuit of the cooling medium can be a closed loop.

[0057] In the first alternative embodiment, please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of the first embodiment provided in this application. Figure 4 In this design, the flywheel rotor shaft has a central through-hole, with both ends extending out of the flywheel housing. Both ends are sealed using magnetohydrodynamic seals to achieve internal spatial sealing within the flywheel housing. The flywheel rotor's cooling tank operates at atmospheric pressure, allowing for convective heat exchange between the cooling tank walls and the external environment, thus achieving heat dissipation and cooling of the flywheel rotor. In specific convective cooling implementation schemes, natural cooling can be used. The temperature of the hole wall where the motor rotor is located is higher; after heating the surrounding air, the hot air rises and is discharged from the top, while corresponding cool air is replenished from the bottom, achieving airflow-based heat dissipation. Alternatively, cooling pipes can be installed at the bottom to carry the cooling medium, with the heated medium discharged from the top.

[0058] In the second alternative embodiment, please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of the second embodiment provided in this application. Figure 5 In this design, the magnetohydrodynamic sealing structure remains unchanged, and a similar closed-loop cooling structure with a refrigeration compressor is adopted. The evaporator is made into a coil form, or, for ease of manufacturing, directly made into a U-shaped tube form. The heat exchanger is inserted into the cooling groove of the flywheel rotor, and this structure is used to improve the heat dissipation capacity of the flywheel rotor.

[0059] In a third alternative embodiment, the magnetohydrodynamic seal of this application can be installed at the bottom of the flywheel housing, with a hole made at the center of the lower end shaft of the flywheel rotor, and a cooling medium can be passed through the bottom for cooling.

[0060] This application also provides a flywheel energy storage motor, including a cooling device for the rotor of the flywheel energy storage motor as described above.

[0061] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0062] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interface; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0063] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0064] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0065] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] Finally, it should be noted that the above embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A cooling device for the rotor of a flywheel energy storage motor, characterized in that, include: A flywheel housing, wherein a first cavity is formed inside the flywheel housing; A flywheel rotor extends into the interior of the first cavity, with one end of the flywheel rotor's shaft extending out of the flywheel housing. A pre-set device is used to seal the cavity to form a vacuum-sealed cavity. A cooling groove is provided inside the central shaft of the flywheel rotor, and the axial length of the cooling groove extends from the top of the flywheel rotor extending out of the vacuum cavity to a pre-set position. The motor rotor is disposed on the side wall of the flywheel rotor, coaxial with the flywheel rotor, and located within the axial length of the cooling tank; Cooling pipes are inserted into the cooling tank of the flywheel rotor to deliver cooling medium to the cooling tank in order to cool the motor rotor of the flywheel.

2. The cooling device according to claim 1, characterized in that, The cooling device also includes a magnetic fluid seal. The magnetohydrodynamic seal is installed in the area where the flywheel rotor extends out of the housing and is fixedly connected to the flywheel housing to isolate the vacuum environment inside the flywheel housing from the external environment.

3. The cooling device according to claim 1, characterized in that, The portion of the cooling pipe extending into the cooling tank is provided with multiple radially penetrating through holes, which are used to allow the cooling medium to be sprayed out radially and to exchange heat with the inner wall of the cooling tank through convection.

4. The cooling device according to claim 1, characterized in that, The cooling device also includes a reflux shroud. The return shroud is fixed to the flywheel housing and covers the protruding end of the flywheel rotor, and is used to collect the cooling medium after convective heat exchange in the cooling tank.

5. The cooling device according to claim 2, characterized in that, The magnetic fluid seal includes a base, magnetic poles, a magnetic ring, and magnetic fluid. The base is fixedly connected to the flywheel housing and forms a second cavity with the outer wall of the flywheel rotor; The magnetic ring and magnetic poles are both disposed within the second cavity; The magnetic fluid fills the gap between the magnetic poles and the flywheel rotor; The sealing position of the magnetic fluid seal is located at the shaft extension end with the smallest diameter of the flywheel rotor, and a sealing ring is formed by the magnetic fluid under the action of a magnetic field.

6. The cooling device according to claim 1, characterized in that, The cooling medium is isolated from the medium of the magnetohydrodynamic seal.

7. The cooling device according to claim 4, characterized in that, The cooling device also includes a closed-loop structure. One end of the closed-loop structure is connected to the cooling pipe, and the other end of the closed-loop structure is connected to the return shroud for circulating cooling of the cooling medium.

8. The cooling device according to claim 1, characterized in that, The cooling tank inlet is exposed to the external environment so that the cooling device can dissipate heat through convection.

9. The cooling device according to claim 1, characterized in that, The cooling pipes inserted into the cooling tank of the flywheel rotor have no mechanical contact with the flywheel rotor.

10. A flywheel energy storage motor, characterized in that, A cooling device comprising the rotor of a flywheel energy storage motor as described in any one of claims 1-9.

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