Conduction cooling type high-temperature superconducting magnet structure with high energy storage density

Abstract

The invention discloses a conduction cooling type high-temperature superconducting magnet structure with high energy storage density, and belongs to the technical field of high-temperature superconducting energy storage magnets. A plurality of double-pancake coils, wherein the plurality of double-pancake coils are coaxially nested and stacked on the basic frame; an inter-pancake G10 insulating sheet is arranged in the middle of the double-pancake coil and is used for improving the overall insulating property; the inter-double-cake cold conduction plate is arranged between the two adjacent double-cake coils and is used for enhancing the radial heat conduction capability; the magnetic conducting ring is embedded in a hole position on the inner side of the end part of the basic frame and is used for optimizing the distribution of a magnetic field; and the coil radial pre-tightening structure surrounds the outer side of the double-pancake coil and is used for applying radial pre-tightening force to the double-pancake coil. A conduction cooling scheme is adopted, an efficient heat conduction path is constructed through the well-designed cold conduction center column, the framework structure and the cold conduction plate between the two cakes, uniform cooling of the magnet can be achieved, and the operation cost is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature superconducting energy storage magnets, and in particular relates to a conduction-cooled high-temperature superconducting magnet structure with high energy storage density. Background Art

[0002] With the large-scale integration of intermittent renewable energy sources such as wind power and photovoltaics into the power grid, power systems face urgent demands for power fluctuation suppression, instantaneous frequency regulation, and fault current limiting. Traditional energy storage technologies, such as lithium batteries, have slow response times and short cycle lives, while supercapacitors have low energy density, making them difficult to meet the millisecond-level precision control requirements of the power grid. Superconducting magnetic energy storage (SMES) systems, which convert electrical energy into magnetic field energy storage and utilize direct electromagnetic conversion mechanisms, are becoming a key technology supporting the stability of new power systems.

[0003] As the core energy carrier of SMES (superconducting magnetic energy storage) systems, the performance parameters of superconducting magnets directly determine the system's energy storage efficiency and engineering feasibility. Traditional low-temperature superconducting magnets (such as NbTi) must operate in the liquid helium temperature range (4.2K), which results in complex refrigeration system structures and high maintenance costs. Furthermore, due to the material's critical current density, the magnets often require a large volume to achieve the target energy storage capacity, severely restricting the system's energy storage density and engineering application value. In recent years, with the increasing maturity of the preparation process of second-generation high-temperature superconducting materials (such as REBCO tape), superconducting magnet technology is evolving towards higher operating temperature ranges (77K liquid nitrogen temperature range), giving rise to high-temperature superconducting energy storage magnets with both high engineering value and technological breakthroughs. High-temperature superconducting magnets have the following significant advantages: (1) The operating temperature range is greatly improved, and liquid nitrogen cooling or commercial refrigerators can be used to achieve stable operation, significantly reducing the complexity and operating costs of the refrigeration system; (2) At the same operating temperature, high-temperature superconducting materials have a higher critical current density, which enables the magnet structure to be highly compact; (3) A higher thermal stability margin provides a guarantee for system reliability.

[0004] However, current high-temperature superconducting energy storage magnets still face key technical challenges: in a strong magnetic field environment, the critical current density of superconducting materials will show significant degradation (i.e., the "magnetic field pinning effect"). This physical property seriously restricts the further improvement of the magnet's energy storage density. In response to this technical bottleneck, this patent proposes an innovative high-temperature superconducting energy storage magnet structure based on the commercial REBCO high-temperature superconducting tape and magnet optimization design method. By optimizing the magnet geometry and improving the winding arrangement, this design effectively alleviates the negative impact of the magnetic field on the current carrying capacity while maintaining the inherent advantages of high-temperature superconducting materials, thereby achieving a coordinated improvement in energy storage density, structural compactness, and operating economy. Summary of the Invention

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] A high energy storage density conduction-cooled high-temperature superconducting magnet structure, comprising:

[0007] Basic framework;

[0008] Multiple double-pancake coils, multiple double-pancake coils are coaxially nested and stacked on the base frame; a G10 insulation sheet is provided between the double-pancake coils to improve the overall insulation performance;

[0009] A double-panel intercooling plate is provided between two adjacent double-panel coils to enhance radial heat conduction capability;

[0010] A magnetic conductive ring, which is embedded in the inner hole of the end of the basic frame to optimize the magnetic field distribution;

[0011] The coil radial pre-tightening structure surrounds the outer side of the double-pancake coil and is used to apply radial pre-tightening force to the double-pancake coil.

[0012] Furthermore, the basic frame includes a central cooling column, an upper cooling plate, a lower cooling plate, an upper pre-tightening flange and a lower supporting flange;

[0013] The upper pre-tightening flange and the lower supporting flange are respectively arranged at both ends of the central cooling column, the upper cooling plate is arranged on a side of the upper pre-tightening flange close to the lower supporting flange, and the lower cooling plate is arranged on a side of the lower supporting flange close to the upper pre-tightening flange;

[0014] The double-pancake coil is located between the upper cooling plate and the lower cooling plate;

[0015] Among them, the lower cooling plate fits tightly to the upper surface of the lower support flange to form an efficient cooling interface at the bottom; the upper cooling plate and the upper pre-tightening flange are connected to the central cooling column through high-strength connectors to complete the assembly of the overall structure.

[0016] Furthermore, the double-pancake coil is divided into REBCO double-pancake coil A and REBCO double-pancake coil B;

[0017] The REBCO double-pancake coil A and the REBCO double-pancake coil B are coaxially nested and stacked on the central cooling column to form an energy storage magnet winding; wherein, the REBCO double-pancake coil A is located at both ends of the central cooling column; the REBCO double-pancake coil B is located in the middle of the central cooling column.

[0018] Furthermore, the REBCO double-pancake coil A is composed of a REBCO high-temperature superconducting tape wound around the outside of the REBCO double-pancake coil A frame; the REBCO double-pancake coil B is composed of a REBCO high-temperature superconducting tape wound around the outside of the REBCO double-pancake coil B frame.

[0019] Furthermore, the inner diameter of the REBCO double-cake coil A skeleton is the same as the inner diameter of the REBCO double-cake coil B skeleton, and is precisely matched with the outer diameter of the central cooling column to achieve coaxial stacking assembly; the outer diameter of the REBCO double-cake coil A skeleton is larger than the outer diameter of the REBCO double-cake coil B skeleton.

[0020] Furthermore, the upper pre-tightening flange and the lower supporting flange are both provided with array-type threaded holes, and the array-type threaded holes of the upper pre-tightening flange and the lower supporting flange are fastened to the central cooling column through bolt connectors.

[0021] Furthermore, the magnetic conductive ring is made of soft magnetic material and is embedded in the inner hole of the end of the central cooling column.

[0022] Furthermore, the central cooling column, the upper cooling plate, the lower cooling plate, the double-cake cooling plate, the REBCO double-cake coil A skeleton and the REBCO double-cake coil B skeleton are all made of oxygen-free copper material.

[0023] Beneficial effects:

[0024] This paper proposes an innovative high-energy-storage-density, conduction-cooled, high-temperature superconducting magnet structure that achieves significant improvements in energy storage performance through multiple innovative design features. This structure utilizes REBCO high-temperature superconducting tape as the conductor material, whose high critical current density lays the foundation for achieving high energy storage density in a compact space.

[0025] In terms of structural design, the present invention adopts a variable inner diameter coil layout scheme: the REBCO double-pancake coil A at the upper and lower ends of the magnet adopts a larger winding inner diameter (the outer diameter of the REBCO double-pancake coil A skeleton is larger than the outer diameter of the REBCO double-pancake coil B skeleton in the middle). This design effectively reduces the attenuation effect of the radial magnetic field component at the end on the critical current of the REBCO strip, thereby significantly improving the overall current-carrying capacity and electromagnetic margin of the magnet.

[0026] To further optimize magnetic field distribution, the present invention incorporates segmented magnetic rings made of soft magnetic materials (such as iron-silicon alloys) within the magnet's interior. These rings are optimized in number and position based on electromagnetic field simulation results, effectively concentrating magnetic flux, reducing magnetic leakage, and improving the magnet's energy storage efficiency.

[0027] In terms of the cooling system, the present invention adopts a conduction cooling solution, and constructs an efficient heat conduction path through a carefully designed cooling center column, skeleton structure and cooling plate between double disks, which can achieve uniform cooling of the magnet and effectively reduce operating costs.

[0028] In summary, this innovative structural design and layout not only solves the technical difficulties of high-temperature superconducting magnets in terms of end current-carrying performance attenuation and leakage magnetic loss, but also achieves the unity of high energy storage density, high reliability and low operating costs. It is particularly suitable for application scenarios such as grid frequency modulation and pulse power that have strict requirements on the performance of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a conduction-cooled high-temperature superconducting magnet structure with high energy storage density.

[0030] Figure 2 Schematic diagram of the structure of the double-pancake coil in a conduction-cooled high-temperature superconducting magnet.

[0031] Explanation of the accompanying symbols: 1-central cooling column, 2-lower supporting flange, 3-lower cooling plate, 4-REBCO double-pancake coil A, 5-REBCO double-pancake coil A skeleton, 6-REBCO double-pancake coil B, 7-REBCO double-pancake coil B skeleton, 8-cooling plate between double pancakes, 9-G10 insulating sheet between pancakes, 10-upper cooling plate, 11-upper pre-tightening flange, 12-magnetic ring, 13-coil radial pre-tightening structure. DETAILED DESCRIPTION

[0032] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0034] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0035] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0036] Example 1

[0037] refer to Figure 1 - Figure 2 , a high energy storage density conduction-cooled high-temperature superconducting magnet structure, comprising:

[0038] Basic framework;

[0039] Multiple double-pancake coils are coaxially nested and stacked on the basic frame; an inter-pancake G10 insulation sheet 9 is set in the middle of the double-pancake coil to improve the overall insulation performance;

[0040] The double-cake inter-cooling plate 8 is provided between two adjacent double-cake coils to enhance radial heat conduction capability;

[0041] The magnetic conductive ring 12 is embedded in the inner hole of the end of the basic frame to optimize the magnetic field distribution;

[0042] The coil radial pre-tightening structure 13 surrounds the outer side of the double-pancake coil and is used to apply radial pre-tightening force to the double-pancake coil.

[0043] In this embodiment, the coil radial pre-tightening structure 13 is made of high-strength stainless steel strip. The coil radial pre-tightening structure 13 surrounds the outside of the double-pancake coil to effectively resist the outward electromagnetic force generated by the coil during excitation and operation, ensuring structural stability.

[0044] Preferably, the basic frame includes a central cooling column 1, an upper cooling plate 10, a lower cooling plate 3, an upper pre-tightening flange 11 and a lower support flange 2;

[0045] The upper pre-tightening flange 11 and the lower support flange 2 are respectively arranged at both ends of the central cooling column 1, the upper cooling plate 10 is arranged on the side of the upper pre-tightening flange 11 close to the lower support flange 2, and the lower cooling plate 3 is arranged on the side of the lower support flange 2 close to the upper pre-tightening flange 11;

[0046] The double-pancake coil is located between the upper cooling plate 10 and the lower cooling plate 3;

[0047] Among them, the lower cold conduction plate 3 fits tightly to the upper surface of the lower support flange 2 to form an efficient cold conduction interface at the bottom; the upper cold conduction plate 10 and the upper pre-tightening flange 11 are connected to the central cold conduction column 1 through high-strength connectors to complete the assembly of the overall structure.

[0048] Preferably, the double pancake coil is divided into REBCO double pancake coil A4 and REBCO double pancake coil B6;

[0049] The REBCO double-cake coil A4 and the REBCO double-cake coil B6 are coaxially nested and stacked on the central cooling column 1 to form an energy storage magnet winding; among them, the REBCO double-cake coil A4 is located at both ends of the central cooling column 1; the REBCO double-cake coil B6 is located in the middle of the central cooling column 1.

[0050] Preferably, the REBCO double-pancake coil A4 is formed by winding a REBCO high-temperature superconducting tape around the outer side of the REBCO double-pancake coil A frame 5; the REBCO double-pancake coil B6 is formed by winding a REBCO high-temperature superconducting tape around the outer side of the REBCO double-pancake coil B frame 7.

[0051] In this embodiment, the REBCO double-disc coil A bobbin 5 is designed with a larger outer diameter, and the wound REBCO double-disc coil A4 is installed at the end of the central cooling column 1. This variable diameter structure design effectively suppresses the attenuation effect of the radial magnetic field at the end on the critical current of the REBCO strip by reducing the inner diameter of the end coil, thereby significantly improving the overall current carrying capacity and energy storage density of the magnet.

[0052] In this embodiment, the REBCO twin-pancake coils A4 and B6 are wound using high-precision tension winding equipment. During the winding process, the strip surface is insulated with multiple layers of polyimide film, and the outermost turns are secured using a special fixing process to ensure structural stability. This modular design allows the REBCO twin-pancake coils A4 and B6 to be flexibly assembled according to actual energy storage needs.

[0053] Preferably, the inner diameter of the REBCO double-cake coil A skeleton 5 is the same as the inner diameter of the REBCO double-cake coil B skeleton 7, and is precisely matched with the outer diameter of the central cooling column 1 to achieve coaxial stacking assembly; the outer diameter of the REBCO double-cake coil A skeleton 5 is larger than the outer diameter of the REBCO double-cake coil B skeleton 7.

[0054] Preferably, both the upper pre-tightening flange 11 and the lower supporting flange 2 are provided with array-type threaded holes, and the array-type threaded holes of the upper pre-tightening flange 11 and the lower supporting flange 2 are fastened to the central cooling column 1 through bolt connectors.

[0055] Preferably, the magnetic ring 12 is made of soft magnetic material and is embedded in the inner hole of the end of the central cooling column 1.

[0056] In this embodiment, the magnetic ring 12 is made of a hollow circular ring structure made of a high saturation magnetic induction iron-silicon alloy and is embedded in the internal hole of the central cooling column 1; multiple groups can be set according to the requirements of magnetic flux control and the distribution position can be optimized.

[0057] Preferably, the central cooling column 1, the upper cooling plate 10, the lower cooling plate 3, the cooling plate between the double-cakes 8, the REBCO double-cake coil A skeleton 5 and the REBCO double-cake coil B skeleton 7 are all made of oxygen-free copper material.

[0058] In this embodiment, the double-cake intercooling plate 8 is made of high-purity oxygen-free copper material and its surface is treated with polyimide film, which not only provides excellent thermal conductivity but also ensures electrical insulation reliability. This design not only enhances the conductive cooling effect, but also provides rigid support for coil stacking.

[0059] In this embodiment, the outer diameter difference and quantity ratio of the REBCO double-cake coil A skeleton 5 and the REBCO double-cake coil B skeleton 7 need to be optimized according to the energy storage requirements, strip parameters and space constraints, and the overall design follows the "end gradient enhancement" principle: under the same inner diameter conditions, the influence of the end magnetic field is reduced in an optimal way, and ultimately a high energy storage density is achieved.

[0060] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A high energy storage density conduction-cooled high-temperature superconducting magnet structure, characterized in that: include: Basic framework; Multiple double-pancake coils, multiple double-pancake coils are coaxially nested and stacked on the base frame; a G10 insulation sheet is provided between the double-pancake coils to improve the overall insulation performance; A double-panel intercooling plate is provided between two adjacent double-panel coils to enhance radial heat conduction capability; A magnetic conductive ring, which is embedded in the inner hole of the end of the basic frame to optimize the magnetic field distribution; The coil radial pre-tightening structure surrounds the outer side of the double-pancake coil and is used to apply radial pre-tightening force to the double-pancake coil.

2. A high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 1, characterized in that: The basic frame includes a central cooling column, an upper cooling plate, a lower cooling plate, an upper pre-tightening flange and a lower support flange; The upper pre-tightening flange and the lower supporting flange are respectively arranged at both ends of the central cooling column, the upper cooling plate is arranged on a side of the upper pre-tightening flange close to the lower supporting flange, and the lower cooling plate is arranged on a side of the lower supporting flange close to the upper pre-tightening flange; The double-pancake coil is located between the upper cooling plate and the lower cooling plate; Among them, the lower cooling plate fits tightly to the upper surface of the lower support flange to form an efficient cooling interface at the bottom; the upper cooling plate and the upper pre-tightening flange are connected to the central cooling column through high-strength connectors to complete the assembly of the overall structure.

3. A high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 2, characterized in that: The double-pancake coils are divided into REBCO double-pancake coil A and REBCO double-pancake coil B; The REBCO double-pancake coil A and the REBCO double-pancake coil B are coaxially nested and stacked on the central cooling column to form an energy storage magnet winding; wherein, the REBCO double-pancake coil A is located at both ends of the central cooling column; the REBCO double-pancake coil B is located in the middle of the central cooling column.

4. A high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 3, characterized in that: The REBCO double-pancake coil A is composed of a REBCO high-temperature superconducting tape wound on the outside of the REBCO double-pancake coil A frame; the REBCO double-pancake coil B is composed of a REBCO high-temperature superconducting tape wound on the outside of the REBCO double-pancake coil B frame.

5. A high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 4, characterized in that: The inner diameter of the REBCO double-cake coil A frame is the same as the inner diameter of the REBCO double-cake coil B frame, and is precisely matched with the outer diameter of the central cooling column to achieve coaxial stacking assembly; the outer diameter of the REBCO double-cake coil A frame is larger than the outer diameter of the REBCO double-cake coil B frame.

6. The high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 2, characterized in that: The upper pre-tightening flange and the lower supporting flange are both provided with array-type threaded holes, and the array-type threaded holes of the upper pre-tightening flange and the lower supporting flange are fastened to the central cooling column through bolt connectors.

7. The high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 2, characterized in that: The magnetic conductive ring is made of soft magnetic material and is embedded in the inner hole of the end of the central cooling column.

8. The high energy storage density conduction-cooled high-temperature superconducting magnet structure according to claim 4, characterized in that: The central cooling column, the upper cooling plate, the lower cooling plate, the double-cake cooling plate, the REBCO double-cake coil A frame and the REBCO double-cake coil B frame are all made of oxygen-free copper material.

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