Refrigerating device for superconducting rotor of superconducting motor

Abstract

The invention discloses a refrigerating device for a superconducting rotor of a superconducting motor, which comprises a plurality of pairs of superconducting coils, the superconducting coils are arranged in a liquid medium groove, one end of the liquid medium groove is closed, the other end of the liquid medium groove is connected with a refrigerant conveying pipe, the other end of the refrigerant conveying pipe is connected with a low-temperature module, and a liquid level block is arranged at the position where the liquid medium groove is connected with the refrigerant conveying pipe. A cold shield is arranged outside the liquid medium groove, Dewar is arranged outside the cold shield, and the Dewar is arranged on the superconducting iron yoke in a central symmetry mode. According to the invention, only the coil part of the superconducting rotor is cooled, so that larger air gap flux density is realized. Larger torque and power output are realized under the condition of the same motor volume, and the total volume and the mass of a cooling medium are reduced. And the liquid level block is arranged, so that the superconducting coil is always soaked in the refrigerant medium, and quenching of the superconducting coil is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly relates to a refrigeration device for a superconducting rotor of a superconducting motor. Background Art

[0002] Due to advantages such as small volume, high power density, and high efficiency, superconducting motors show great application prospects in aviation electric propulsion and wind turbines. According to the application location of superconducting materials, superconducting motors are divided into stator semi-superconducting motors, rotor semi-superconducting motors, and fully superconducting motors. Limited by the DC characteristics of superconducting materials, rotor semi-superconducting motors have become the current mainstream development direction. The rotor semi-superconducting motor uses superconducting materials to wind the motor rotor, which can provide a stronger air-gap magnetic flux density while reducing the power loss of the motor. The stator still uses conventional copper wires for winding. The cooling system of the superconducting materials in the rotor part often adopts a cooling scheme of immersing the entire rotor system (including superconducting coils and rotor yokes) in a refrigerant medium.

[0003] This cooling scheme increases the air gap between the rotor and the stator. The air gap size of a conventional permanent magnet motor is between 1 - 2 mm, while the air gap size of the existing cooling scheme needs to be 15 - 17 mm to ensure the refrigerant tank, cold screen, and Dewar space required by the refrigeration system. The increase in the air gap will lead to a decrease in the air-gap magnetic flux density, making it difficult to reflect the advantages of the strong magnetic field of the superconducting magnet. Because the entire rotor system needs to be cooled, the existing cooling scheme requires more refrigerant medium, increasing the weight of the superconducting motor and also requiring frequent replenishment of the refrigerant medium during daily use. There is also a cooling scheme that indirectly cools the rotor coil through a cooling skeleton, such as the prior art CN109713876B. Although it can avoid the disadvantages of overall cooling, the cooling effect of the technical scheme of indirectly cooling through a cooling skeleton is not as good as direct cooling, and the structure is complex, making it inconvenient for maintenance and repair.

[0004] There is also a technical solution. For example, in the prior art CN103825387B, although a technical solution for directly cooling the stator of a superconducting motor is disclosed, there are huge differences between the cooling of the superconducting stator and the cooling of the superconducting rotor itself. From the perspective of the design of the cooling scheme, the cooling schemes of the stator and rotor coils have different focuses. The superconducting stator coil generally operates under an AC condition of 50 Hz. Its biggest problem is that the AC power loss causes the superconducting wire to heat up and quench or even burn out. Therefore, the focus of its cooling scheme is large cooling capacity and sufficient refrigerant medium. The superconducting rotor coil is in a DC condition and there is no heating problem. Its focus lies in low-temperature rotary sealing. From the perspective of specific implementation, the stator coil does not need to rotate and is in a static state. The stator coil only needs to be simply immersed in the refrigerant, and the cooling structure is simple. The superconducting rotor coil is in a high-speed rotating state, and problems such as the sealing of the rotating low-temperature refrigerant medium, the ineffective contact of the top coil with the refrigerant, the dynamic delivery of the cooling medium during cooling, and the prevention of the cooling medium from being thrown out by the rotating centrifugal force during cooling need to be considered. The cooling structure of the superconducting rotor is more complex. Therefore, the cooling scheme of the superconducting stator cannot solve the problems generated during the cooling of the superconducting rotor and cannot be directly applied to the cooling of the superconducting rotor.

[0005] Moreover, based on the existing rotor cooling scheme, before starting the machine, when the rotor is stationary, the refrigerant medium will accumulate at the bottom of the rotor, resulting in the ineffective cooling of the superconducting coil at the top and easily causing the quenching of the superconducting coil. Summary of the Invention

[0006] An embodiment of the present invention provides a refrigeration device for a superconducting rotor of a superconducting motor, which is used to solve the problems in the prior art that due to the cooling system, the air gap of the superconducting motor is large, the quantity requirement for the refrigerant medium is high, the existing direct cooling scheme only cools the stator and cannot be applied to the superconducting rotor, and the superconducting coil at the top cannot be effectively cooled when the rotor is stationary, easily causing the quenching of the superconducting coil.

[0007] On the one hand, an embodiment of the present invention provides a refrigeration device for a superconducting rotor of a superconducting motor, including: Superconducting coils, multiple pairs of superconducting coils are provided, the superconducting coils are arranged in a liquid medium tank, one end of the liquid medium tank is closed, the other end of the liquid medium tank is connected to a refrigerant delivery pipe, the other end of the refrigerant delivery pipe is connected to a low-temperature module, a liquid level block is arranged at the connection of the liquid medium tank and the refrigerant delivery pipe, a cold shield is arranged outside the liquid medium tank, and a Dewar is arranged outside the cold shield, and the Dewar is symmetrically arranged at the center of the superconducting yoke.

[0008] In a possible implementation manner, the number of the liquid medium tanks is set corresponding to the number of the superconducting coils, and the shape and size of the liquid medium tanks are set corresponding to the shape and size of the superconducting coils.

[0009] In a possible implementation, the number of the cold screens is set corresponding to the number of the liquid medium tanks, and the shape and size of the cold screens are set corresponding to the shape and size of the liquid medium tanks.

[0010] In a possible implementation, the number of the dewars is set corresponding to the number of the cold screens, and the shape and size of the dewars are set corresponding to the shape and size of the cold screens.

[0011] In a possible implementation, a refrigerant input pipeline and a refrigerant output pipeline are arranged in the refrigerant delivery pipe.

[0012] In a possible implementation, a refrigerant storage tank and a refrigerant pump are arranged in the cryogenic module.

[0013] A refrigeration device for a superconducting rotor of a superconducting motor in the present invention has the following advantages: (1) Only the superconducting coil part is cooled, and the remaining components of the rotor are in the room temperature state. It is ensured that the air gap of the semi-superconducting rotor motor can be made the same as that of a conventional motor, which is 1 - 2 mm, so that a larger air gap magnetic density can be achieved, avoiding the problem of small magnetic density in the large air gap of a conventional superconducting motor. Larger torque and power output can be achieved under the same motor volume.

[0014] (2) The total volume and mass of cooling are reduced, the consumption of the refrigerant medium is saved, the weight of the superconducting motor is reduced, and a liquid level block is provided to ensure that the superconducting coil is always immersed in the refrigerant medium, effectively avoiding the occurrence of quench of the superconducting coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a schematic side structure view of a refrigeration device for a superconducting rotor of a superconducting motor provided by an embodiment of the present invention; Figure 2 It is a schematic cross-sectional structure view of a refrigeration device for a superconducting rotor of a superconducting motor provided by an embodiment of the present invention; Figure 3 It is a schematic view of a single superconducting coil and a cooling structure of a refrigeration device for a superconducting rotor of a superconducting motor provided by an embodiment of the present invention.

[0017] Explanation of the marks in the figure: 1, superconducting coil; 11, liquid level block; 2, liquid medium tank; 21, refrigerant delivery pipe; 3, cold screen; 4, dewar; 5, superconducting yoke; 6, cryogenic module. Specific Embodiments

[0018] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0019] Figure 1 It is a schematic side view of a refrigeration device for a superconducting rotor of a superconducting motor provided by an embodiment of the present invention; an embodiment of the present invention provides a refrigeration device for a superconducting rotor of a superconducting motor, including: Superconducting coils 1, multiple pairs of the superconducting coils 1 are provided, the superconducting coils 1 are arranged in a liquid medium tank 2, one end of the liquid medium tank 2 is closed, the other end of the liquid medium tank 2 is connected to a refrigerant delivery pipe 21, the other end of the refrigerant delivery pipe 21 is connected to a cryogenic module 6, a liquid level block 11 is provided at the connection of the liquid medium tank 2 and the refrigerant delivery pipe 21, a cold shield 3 is provided outside the liquid medium tank 2, a Dewar 4 is provided outside the cold shield 3, and the Dewar 4 is symmetrically arranged at the center of a superconducting yoke 5.

[0020] Exemplarily, the superconducting coils 1 are arranged in pairs, any number of pairs of the superconducting coils 1 are provided, a liquid medium tank 2 is closely arranged outside the superconducting coils 1, the refrigerant is delivered to the liquid medium tank 2 through the refrigerant delivery pipe 21 to cool the superconducting coils 1, a cold shield 3 is provided outside the liquid medium tank 2, the cold shield 3 can isolate the liquid medium tank 2 so that the temperature of the refrigerant does not affect the outside of the cold shield 3, a Dewar 4 is also provided outside the cold shield 3 for storing and confining the refrigerant, the superconducting yoke 5 is always in a normal temperature state under the influence of the cold shield 3 and the Dewar 4, the refrigerant only cools the superconducting coils 1, and the liquid level block 11 is used to confine the refrigerant to ensure that all the superconducting coils 1 are immersed in the refrigerant when the superconducting rotor is stationary before starting, avoiding quenching.

[0021] In a possible embodiment, the number of the liquid medium tanks 2 is set corresponding to the number of the superconducting coils 1, the shape and size of the liquid medium tanks 2 are set corresponding to the shape and size of the superconducting coils 1, the number of the cold shields 3 is set corresponding to the number of the liquid medium tanks 2, the shape and size of the cold shields 3 are set corresponding to the shape and size of the liquid medium tanks 2, the number of the Dewars 4 is set corresponding to the number of the cold shields 3, and the shape and size of the Dewars 4 are set corresponding to the shape and size of the cold shields 3.

[0022] Exemplarily, as Figure 2 、 3 shown, the liquid medium tanks 2, the cold shields 3 and the Dewars 4 are set according to the shape and size of the superconducting coils 1, which is convenient for the refrigerant to cool the superconducting coils 1 specifically.

[0023] In a possible embodiment, a refrigerant input pipeline and a refrigerant output pipeline are provided inside the refrigerant delivery pipe 21, and a refrigerant storage tank and a refrigerant pump are provided inside the low-temperature module 6.

[0024] Exemplarily, the refrigerant delivery pipe 21 is provided with a refrigerant input pipe and a refrigerant output pipe. The low-temperature module 6 controls the refrigerant to pass through the refrigerant input pipe and the refrigerant output pipe to be cooled in the liquid medium tank 2 through the refrigerant pump. A refrigerant storage tank for storing the refrigerant is also provided inside the low-temperature module 6.

[0025] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0026] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A refrigeration device for a superconducting rotor of a superconducting motor, characterized in that: include: A superconducting coil (1), wherein a plurality of pairs of superconducting coils (1) are provided, wherein the superconducting coils (1) are provided in a liquid medium tank (2), wherein one end of the liquid medium tank (2) is closed, and the other end of the liquid medium tank (2) is connected to a refrigerant delivery pipe (21), and the other end of the refrigerant delivery pipe (21) is connected to a low-temperature module (6), wherein a liquid level block (11) is provided at the point where the liquid medium tank (2) is connected to the refrigerant delivery pipe (21), wherein a cold shield (3) is provided outside the liquid medium tank (2), wherein a dewar (4) is provided outside the cold shield (3), and wherein the dewar (4) is centrally symmetrically provided on a superconducting iron yoke (5).

2. A refrigeration device for a superconducting rotor of a superconducting motor according to claim 1, characterized in that: The number of the liquid medium tanks (2) is set corresponding to the number of the superconducting coils (1), and the shape and size of the liquid medium tanks (2) are set corresponding to the shape and size of the superconducting coils (1).

3. A refrigeration device for a superconducting rotor of a superconducting motor according to claim 1, characterized in that: The number of the cold shields (3) is set corresponding to the number of the liquid medium tanks (2), and the shape and size of the cold shields (3) are set corresponding to the shape and size of the liquid medium tanks (2).

4. A refrigeration device for a superconducting rotor of a superconducting motor according to claim 1, characterized in that: The number of the dewars (4) corresponds to the number of the cold shields (3), and the shape and size of the dewars (4) correspond to the shape and size of the cold shields (3).

5. A refrigeration device for a superconducting rotor of a superconducting motor according to claim 1, characterized in that: A refrigerant input pipeline and a refrigerant output pipeline are arranged in the refrigerant delivery pipe (21).

6. A refrigeration device for a superconducting rotor of a superconducting motor according to claim 1, characterized in that: A refrigerant storage tank and a refrigerant pump are provided in the low-temperature module (6).

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