Ultrahigh energy storage density superconducting flywheel energy storage system containing additional centripetal force device

Abstract

The invention belongs to the field of flywheel energy storage, particularly relates to an ultrahigh energy storage density superconducting flywheel energy storage system containing an additional centripetal force device, and aims to solve the problem that the rotating speed of a flywheel is limited by the strength of a material. The device comprises a vacuum cavity, a driving device, a flywheel, an additional centripetal force providing device and a high-temperature superconducting magnetic suspension bearing. The driving device is in transmission connection with the flywheel, and the additional centripetal force providing device is arranged on the outer side of the flywheel and can provide additional centripetal force for the flywheel, so that the rotating speed of the flywheel can be higher than the limit rotating speed determined by the limit strength of a flywheel material, and the problem that the rotating speed of the flywheel is limited by the material strength is solved; and the superconductive flywheel energy storage system can realize ultrahigh energy density energy storage.

Description

Technical Field

[0001] The invention belongs to the field of flywheel energy storage, and in particular relates to an ultra-high energy storage density superconducting flywheel energy storage system containing an additional centripetal force device. Background Art

[0002] Flywheel energy storage is a technology that uses a rotating flywheel to store energy. It has the advantages of high energy storage density, high power, high efficiency, long life, and no pollution. However, when the flywheel rotor speed of the flywheel energy storage system reaches or approaches the limit speed of the flywheel material, it will deform or be damaged due to excessive centrifugal force, making it difficult to further increase the capacity of the flywheel energy storage system.

[0003] Increasing the speed of the flywheel rotor is the key to increasing the energy storage capacity of the flywheel energy storage system. However, when the flywheel rotates at high speed, it will generate a large centrifugal force. When the centrifugal force increases to the centripetal force limit that the flywheel material can provide, the flywheel will deform or be damaged. How to reduce the deformation and damage of the flywheel when it rotates at high speed to increase the storage capacity of the flywheel energy storage system has become an urgent problem to be solved in the current field of flywheel energy storage technology.

[0004] Theoretically, the strength of the flywheel material determines the size of the centripetal force that the flywheel rotation can provide, and the ultimate (maximum) strength of the flywheel material determines the maximum speed that the flywheel can reach, that is, the energy storage or energy storage density of the flywheel energy storage system is limited by the ultimate strength of the flywheel material. The higher the value, the greater the theoretical energy storage or energy storage density. To this end, relevant institutions have carried out a lot of exploration on improving the strength of flywheel materials. For example, Chinese invention patent CN103867639A adopts a step-by-step winding curing process and a tension-reducing winding process in the flywheel preparation process, which solves the problem that the metal flywheel has low strength and cannot meet the high-speed use of the flywheel. Chinese invention patent CN106369107A adds elements such as nickel, chromium, molybdenum, lanthanum, gadolinium and yttrium to the flywheel material to improve the strength of the flywheel material. Chinese invention patent CN105864358A uses a carbon fiber composite flywheel in a flywheel energy storage system. The flywheel is made of multiple layers of carbon fiber prepreg circles stacked at different angles, which are molded and then machined, thereby improving the circumferential tensile strength of the flywheel and preventing it from being damaged when rotating at high speeds, thereby increasing the flywheel speed and solving the problem of low strength of metal flywheels and their inability to rotate at high speeds for energy storage.

[0005] In summary, existing research and inventions mostly adopt the development of higher strength composite materials to increase the limit (maximum) speed of the flywheel and the energy storage density of the flywheel energy storage system, but they cannot break through the limit speed determined by the limit strength of the flywheel material itself, and cannot fundamentally solve the problem that the flywheel speed is limited by the strength of the material itself. Summary of the invention

[0006] In order to solve the problem in the prior art that the speed of the flywheel is limited by the strength of the material itself, the present invention provides an ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device, including a vacuum chamber, a driving device, a flywheel, an additional centripetal force providing device, and a high-temperature superconducting magnetic levitation bearing.

[0007] The driving device is transmission-connected to the flywheel, and the additional centripetal force providing device is arranged on the outer side of the flywheel.

[0008] Wherein, the additional centripetal force providing device can provide additional centripetal force to the flywheel.

[0009] According to some embodiments of the present application, an ultra-high energy storage density superconducting flywheel energy storage system containing an additional centripetal force device is provided, wherein the additional centripetal force providing device includes a superconducting current-carrying layer and a magnet.

[0010] The superconducting current-carrying layer is coaxially arranged with the flywheel, and the superconducting current-carrying layer is arranged in a ring shape to form a continuous surrounding structure. The magnet is located on both sides of the superconducting current-carrying layer in the axial direction. The Ampere force exerted on the superconducting current-carrying layer in the magnetic field generated by the magnet points to the center of the flywheel, exerting a centripetal force on the flywheel.

[0011] According to some embodiments of the present application, an ultra-high energy storage density superconducting flywheel energy storage system containing an additional centripetal force device is provided, wherein the superconducting current-carrying layer is composed of multiple layers of superconducting tapes or superconducting films.

[0012] According to some embodiments of the present application, an ultra-high energy storage density superconducting flywheel energy storage system containing an additional centripetal force device further includes a high-temperature superconducting magnetic suspension bearing, and the high-temperature superconducting magnetic suspension bearing is coaxially arranged with the flywheel.

[0013] According to some embodiments of the present application, an ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device is provided, wherein the high-temperature superconducting magnetic levitation bearing includes a rotor, and the rotor is made of a permanent magnet (neodymium iron boron magnet or samarium cobalt magnet) and a magnet ring.

[0014] According to an ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device provided in some embodiments of the present application, the high-temperature superconducting magnetic bearing also includes a stator, and the stator is made of a high-temperature superconducting block (REBCO or MgB2 block).

[0015] According to an ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device provided in some embodiments of the present application, the REBCO high-temperature superconducting block is at least one of yttrium, neodymium, samarium, gadolinium or dysprosium, or a MgB2 block.

[0016] According to some embodiments of the present application, an ultra-high energy storage density superconducting flywheel energy storage system containing an additional centripetal force device is provided, wherein the driving device is a motor.

[0017] Beneficial effects of the present invention:

[0018] (1) By providing an additional centripetal force providing device, the problem of the flywheel speed being restricted by the material strength is solved, so that the flywheel speed can be higher than the limit speed determined by the limit strength of the flywheel material itself, so that the superconducting flywheel energy storage system can achieve ultra-high energy density energy storage.

[0019] (2) It can provide a stable and reliable additional centripetal force for the flywheel rotor, offset part of the centrifugal force during the operation of the flywheel rotor, increase the maximum speed of the flywheel rotor, and improve the storage capacity and energy storage density of the flywheel energy storage system.

[0020] (3) It can also further provide a self-stabilizing suspension force for the flywheel, improve the suspension stiffness, effectively solve the problem of relatively weak suspension stiffness of the superconducting bearing, and further improve the stability and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0022] Figure 1 It is a schematic diagram of the structure of some embodiments of the present application;

[0023] Figure 2 This is a calculation case result diagram showing that the allowable stress is reached when the flywheel speed is 5440rpm without adding an additional centripetal force device;

[0024] Figure 3 This is a calculation case result diagram in which an additional centripetal force device is added and the allowable stress is reached only when the flywheel speed is 5730rpm.

[0025] In the figure: 1. vacuum chamber; 2. motor; 3. flywheel; 4. additional centripetal force providing device; 41. superconducting current-carrying layer; 42. magnet; 5. high-temperature superconducting magnetic bearing; 51. rotor; 52. stator. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] like Figure 1 As shown, the present invention provides an ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device, including a vacuum chamber 1, a driving device 2, a flywheel 3, an additional centripetal force providing device 4, and a high-temperature superconducting magnetic suspension bearing 5.

[0029] The driving device 2 is transmission-connected to the flywheel 3 , and the additional centripetal force providing device 4 is arranged on the outer side of the flywheel 3 .

[0030] The additional centripetal force providing device 4 can provide additional centripetal force to the flywheel 3 .

[0031] During specific implementation, a vacuum environment is provided for the flywheel 3 through the vacuum chamber 1, and the driving device is a motor 2. The motor 2 is located at the top of the vacuum chamber 1, and the motor 2 is a high-speed motor. The motor 2 drives the flywheel 3 to rotate. An additional centripetal force providing device 4 is provided to provide a stable and reliable additional centripetal force for the flywheel 3, thereby offsetting part of the centrifugal force during the operation of the flywheel 3, increasing the maximum rotation speed of the flywheel 3, and further improving the storage capacity and energy storage density of the flywheel energy storage system.

[0032] In some implementations, the additional centripetal force providing device 4 includes a superconducting current-carrying layer 41 and a magnet 42 .

[0033] The superconducting current-carrying layer 41 is coaxially arranged with the flywheel 3 and is arranged in a ring shape to form a continuous surrounding structure, which can generate a constant current by induction. The magnet 42 is located on both sides of the superconducting current-carrying layer 41 axially. The Ampere force exerted on the superconducting current-carrying layer 41 in the magnetic field generated by the magnet 42 points to the center of the flywheel 3, exerting a centripetal force on the flywheel 3.

[0034] In specific implementation, the magnets 42 of the additional centripetal force providing device 4 are located on the upper and lower sides of the superconducting current-carrying layer 41 in the axial direction. Refrigeration means can be used to reduce the temperature of the high-temperature superconducting magnetic suspension bearing 5 and the superconducting current-carrying layer 41 on the outer edge of the flywheel 3 to below the critical temperature of the superconductor, so that it is in a superconducting state; the superconducting current-carrying layer 41 forms a constant current through induction excitation, and after excitation, the superconducting current-carrying layer 41 operates in a closed loop; the superconducting current-carrying layer 41 is located in the magnetic field generated by the magnet 42, so that the Ampere force it receives is radially directed to the center of the flywheel 3, providing additional centripetal force for the flywheel 3, such as Figure 1 As shown in the figure, the direction pointed by F is the direction of the additional centripetal force. The additional centripetal force can offset part of the centrifugal force of the flywheel 3, thereby increasing the maximum rotational speed of the flywheel 3, effectively solving the problem in the prior art that the flywheel is difficult to break through the material maximum speed when rotating at high speed, thereby improving the energy storage density, stability and safety of the system.

[0035] In some embodiments, the superconducting current-carrying layer 41 is composed of multiple layers of superconducting tapes or superconducting films, which are arranged in a ring shape to form a continuous surrounding structure and are coaxially and concentrically disposed with the flywheel 3 .

[0036] In some embodiments, a high-temperature superconducting magnetic bearing 5 is also included, and the high-temperature superconducting magnetic bearing 5 is coaxially arranged with the flywheel 3 .

[0037] In specific implementation, the high temperature superconducting magnetic bearing 5 is provided with two groups, such as Figure 1 As shown, two groups of high-temperature superconducting magnetic bearings 5 ​​are respectively located on the upper and lower sides of the flywheel 3 .

[0038] In some embodiments, the high temperature superconducting magnetic bearing 5 includes a rotor 51, and the rotor 51 is made of a permanent magnet (neodymium iron boron magnet or samarium cobalt magnet) and a magnet ring.

[0039] In specific implementation, the rotor 51 in the superconducting magnetic bearing is made of permanent magnets (neodymium iron boron magnets (NdFeB) or samarium cobalt magnets (SmCo)) and a magnet ring, and is coaxial with the flywheel 3 in the high-temperature superconducting flywheel energy storage system to provide a magnetic field for the stator 52 and generate a stable suspension force.

[0040] In some embodiments, the high temperature superconducting magnetic bearing 5 further includes a stator 52, and the stator 52 is made of a high temperature superconducting block (REBCO or MgB2 block).

[0041] In specific implementation, the stator 52 of the superconducting magnetic bearing is made of REBCO high-temperature superconducting blocks, which are one of yttrium (Y), neodymium (Nd), samarium (Sm), gadolinium (Gd), and dysprosium (Dy). It is fixed under the high-temperature superconducting flywheel energy storage system to provide suspension force for the rotor 51.

[0042] The present invention covers the outer surface of the flywheel 3 with a superconducting current-carrying layer 41, and utilizes the Ampere force exerted on the current in the superconducting layer in the magnetic field to provide additional centripetal force for the flywheel rotor, thereby breaking through the limit speed of the flywheel material and improving the capacity, energy storage density and system safety and stability of the flywheel energy storage system.

[0043] like Figure 2-3 As shown, taking the calculation of T700 carbon fiber flywheel as an example, the calculation parameters are shown in the following table.

[0044] The first step is to calculate the maximum speed of the flywheel without an additional centripetal force providing device. The calculation results show that under the strength limit of the flywheel material (reaching the allowable stress), the maximum speed of the flywheel is 5440rpm. The stress distribution of the flywheel at a speed of 5440rpm is as follows: Figure 2shown.

[0045] The second step is to calculate the centripetal stress of 10MPa provided by the additional centripetal force device. The calculation results show that under the strength limit of the flywheel material (reaching the allowable stress), the maximum speed of the flywheel is 5730rpm. The stress distribution of the flywheel at a speed of 5730rpm is as follows: Figure 3 shown.

[0046] In summary, in this case, the additional centripetal force providing device provides a centripetal stress of 10MPa, the maximum speed of the flywheel can be increased by 290rpm, and the energy storage capacity is increased by 6%. With current technology, an additional centripetal force of 10MPa is easy to achieve. By optimizing the design of the additional centripetal force providing device, it can provide a higher additional centripetal force (such as 100MP), thereby greatly improving the energy storage and energy storage density of the system.

[0047] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0048] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0050] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, 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 be included in the protection scope of the present invention.

Claims

1. An ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device, characterized in that: It comprises a vacuum chamber (1), a driving device (2), a flywheel (3), an additional centripetal force providing device (4), and a high-temperature superconducting magnetic suspension bearing (5); The driving device (2) is drivingly connected to the flywheel (3), and the additional centripetal force providing device (4) is arranged on the outside of the flywheel (3); Wherein, the additional centripetal force providing device (4) is capable of providing additional centripetal force to the flywheel (3).

2. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 1, characterized in that: The additional centripetal force providing device (4) comprises a superconducting current-carrying layer (41) and a magnet (42); The superconducting current-carrying layer (41) is coaxially arranged with the flywheel (3); the superconducting current-carrying layer (41) is arranged in a ring shape to form a continuous surrounding structure; the magnets (42) are located on both axial sides of the superconducting current-carrying layer (41); the Ampere force exerted on the superconducting current-carrying layer (41) in the magnetic field generated by the magnets (42) points to the center of the flywheel (3), exerting a centripetal force on the flywheel (3).

3. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 2, characterized in that: The superconducting current-carrying layer (41) is composed of multiple layers of superconducting tapes or superconducting films.

4. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 2, characterized in that: It also comprises a high-temperature superconducting magnetic suspension bearing (5), wherein the high-temperature superconducting magnetic suspension bearing (5) is coaxially arranged with the flywheel (3).

5. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 4, characterized in that: The high-temperature superconducting magnetic suspension bearing (5) comprises a rotor (51), and the rotor (51) is made of a permanent magnet and a magnet ring.

6. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 5, characterized in that: The high-temperature superconducting magnetic suspension bearing (5) further comprises a stator (52), wherein the stator (52) is made of a high-temperature superconducting block material.

7. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 6, characterized in that: The high temperature superconducting block is at least one of yttrium, neodymium, samarium, gadolinium or dysprosium, or magnesium diboride MgB2 material.

8. The ultra-high energy storage density superconducting flywheel energy storage system with an additional centripetal force device according to claim 1, characterized in that: The driving device is a motor (2).

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