Superconducting cable

Abstract

The invention provides a superconducting cable, and relates to the technical field of superconducting cables. The superconducting cable comprises a superconducting conductor layer, a first supporting framework, a main insulating layer, a superconducting shielding layer and a heat insulation structure which are sequentially arranged from inside to outside. The superconducting conductor layer is used for power transmission. A first cooling channel is formed between the superconducting conductor layer and the first supporting framework, and the first cooling channel is filled with a cooling medium. A second cooling channel is formed between the superconducting shielding layer and the heat insulation structure, and the second cooling channel is filled with a cooling medium. According to the superconducting cable provided by the invention, efficient electric energy transmission and electromagnetic shielding are realized, meanwhile, the energy loss is reduced, and the insulation reliability and the overall energy efficiency of the superconducting cable are improved.

Description

Technical Field

[0001] The present application relates to the technical field of superconducting cables, and in particular to a superconducting cable. Background Art

[0002] Superconducting cables, based on the zero-resistance characteristics of superconducting materials under deep cryogenic conditions, can achieve near-lossless transmission of large-capacity electrical energy. They are a cutting-edge power transmission technology that breaks through the boundaries of current density and transmission efficiency of traditional conductive materials.

[0003] In related technologies, the insulation and shielding layers of superconducting cables are key structures for the safe and stable operation of superconducting cables. The insulation layer is used to isolate the superconducting conductors of the superconducting cable to prevent leakage, while the shielding layer is used to shield the magnetic field of the superconducting cable.

[0004] However, the insulation layer and / or shielding layer of the existing superconducting cable is poor, which affects the safety and reliability of power transmission of the superconducting cable. Summary of the Invention

[0005] In view of the above problems, an embodiment of the present application provides a superconducting cable to improve the safety and reliability of power transmission of the superconducting cable.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The present application provides a superconducting cable comprising: a superconducting conductor layer, a first supporting frame, a primary insulating layer, a superconducting shielding layer, and a thermal insulation structure, arranged in order from the inside out. The superconducting conductor layer is used for power transmission. A first cooling channel is formed between the superconducting conductor layer and the first supporting frame, and is filled with a cooling medium. A second cooling channel is formed between the superconducting shielding layer and the thermal insulation structure, and is filled with a cooling medium.

[0008] In a possible implementation manner, the main insulating layer is an integrally formed insulating layer.

[0009] In a possible implementation manner, the system further includes: a second supporting frame, wherein the second supporting frame is disposed inside the superconducting conductor layer.

[0010] In a possible implementation, the second supporting skeleton is a solid structure; or, the second supporting skeleton is a hollow structure and forms a third cooling channel, and the third cooling channel is filled with a cooling medium.

[0011] In a possible embodiment, the second supporting frame is a hollow structure, and the third cooling channel and the second cooling channel are respectively connected to the first cooling channel;

[0012] Alternatively, the third cooling channel and the first cooling channel are respectively communicated with the second cooling channel.

[0013] In a possible implementation, the first support frame is a flexible metal support frame.

[0014] In a possible implementation, an outer insulating layer is further provided outside the superconducting shielding layer, and a second cooling channel is formed between the outer insulating layer and the thermal insulation structure.

[0015] In a possible implementation, the thermal insulation structure includes a thermal insulation inner tube, a thermal insulation layer, and a thermal insulation outer tube, which are sequentially arranged from the inside to the outside.

[0016] In a possible implementation, a vacuum layer is formed between the inner tube of the thermal insulation tube and the outer tube of the thermal insulation tube.

[0017] In a possible implementation, the superconducting cable further includes: a sheath layer: the sheath layer is disposed on the outside of the thermal insulation structure.

[0018] The superconducting cable provided herein comprises, arranged from the inside out, a superconducting conductor layer, a first support frame, a main insulating layer, a superconducting shielding layer, and an insulating structure. The superconducting conductor layer serves as the core power transmission component, responsible for power transmission. The insulating structure provides thermal insulation protection for the low-temperature environment within the cable, minimizing cooling losses. Furthermore, a first cooling channel is formed between the superconducting conductor layer and the first support frame. The first cooling channel is filled with a cooling medium that directly contacts the superconducting conductor layer, ensuring sufficient cooling of the superconducting conductor layer. A second cooling channel is formed between the superconducting shielding layer and the insulating structure. The second cooling channel is filled with a cooling medium that provides continuous heat exchange and cooling for the superconducting shielding layer. By placing the superconducting shielding layer in a low-temperature environment, efficient electromagnetic shielding can be achieved by utilizing the zero-resistance property of the superconducting material while avoiding Joule losses caused by induced current in the room-temperature metal shielding layer, thereby improving the overall energy efficiency of the superconducting cable. The superconducting cable provided herein not only improves insulation performance but also thermal insulation performance. The two performances work together to effectively enhance the safety and reliability of power transmission in the superconducting cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of the structure of a superconducting cable provided in an embodiment of the present application.

[0021] Description of reference numerals:

[0022] 10-superconducting cables;

[0023] 100-second supporting frame; 200-superconducting conductor layer; 300-first supporting frame; 400-main insulating layer; 500-superconducting shielding layer; 600-thermal insulation structure; 700-outer insulating layer; 800-jacket layer;

[0024] 610-insulated inner tube; 620-insulated layer; 630-insulated outer tube; 640-vacuum layer;

[0025] a-third cooling channel; b-first cooling channel; c-second cooling channel. DETAILED DESCRIPTION

[0026] As described in the background technology section, superconducting cables are a revolutionary power transmission technology based on the zero-resistance properties of superconducting materials at low temperatures. They typically consist of a superconducting conductor layer, an insulating layer, and a shielding layer. They are maintained in a superconducting state by a cooling medium such as liquid nitrogen, enabling lossless transmission of gigawatt-level electrical energy. Their core value lies in surpassing the current density limits of traditional cables. They are suitable for high-load scenarios such as urban power grid expansion and the intensive transmission of renewable energy generation, making them a key component in building new power systems.

[0027] Currently, superconducting cables mainly include two insulation technology systems: room temperature insulation structure and low temperature insulation structure. Among them, room temperature insulation structure superconducting cables place the insulation layer in a room temperature environment, and their shielding layer is usually made of conventional copper or aluminum conductor materials. The shielding layer of a superconducting cable is mainly used to induce a current that is as large as the opposite direction of the superconducting conductor layer to offset the leakage magnetic field of the cable. However, the transmission capacity of superconducting cables is generally very large, and the copper or aluminum shielding layer in a room temperature environment is difficult to effectively and losslessly shield the magnetic field. Especially under high current conditions, the residual leakage magnetic field will cause non-negligible electromagnetic interference to surrounding power equipment, severely limiting its application in complex power grid environments.

[0028] In contrast, the cryogenic insulation structure places the superconducting conductor, insulation layer, and shielding layer in a cryogenic environment, leveraging the perfect diamagnetic properties of the superconducting shielding material to achieve near-ideal electromagnetic shielding. This structure not only eliminates shielding losses but also ensures the overall efficiency of the power transmission system.

[0029] However, in a low-temperature insulation structure, the presence of the insulation layer creates an additional thermal resistance barrier between the superconducting conductor layer and the cooling medium, thereby reducing the heat transfer efficiency of the superconducting conductor layer inside the insulation layer and causing its operating temperature to increase. Furthermore, as the operating voltage level of the superconducting cable increases, the thickness of the insulation layer generally increases, further exacerbating the obstruction effect of the heat conduction path, making it difficult for the heat generated by the superconducting conductor layer to dissipate in a timely and effective manner. This thermal resistance accumulation phenomenon not only causes the local temperature of the superconducting conductor layer to rise, but may also trigger the risk of superconducting state instability, thereby affecting the overall thermal stability of the superconducting cable and threatening the long-term operational reliability of the superconducting cable.

[0030] In light of this, the researchers behind this application designed a superconducting cable to improve the reliability and stability of power transmission through both insulation and thermal insulation. The superconducting cable comprises, arranged from the inside out, a superconducting conductor layer, a first support frame, a primary insulation layer, a superconducting shielding layer, and a thermal insulation structure. The superconducting conductor layer serves as the core power transmission component, carrying out the power transmission function. The thermal insulation structure provides thermal insulation protection for the low-temperature environment inside the cable, minimizing cooling losses.

[0031] In addition, a first cooling channel is formed between the superconducting conductor layer and the first support frame. This channel is filled with a cooling medium that directly contacts the superconducting conductor layer, ensuring sufficient cooling of the superconducting conductor layer. A second cooling channel is formed between the superconducting shielding layer and the thermal insulation structure. This second cooling channel is filled with a cooling medium that provides continuous heat exchange and cooling for the superconducting shielding layer.

[0032] In this way, by placing the superconducting shielding layer in a low-temperature environment, we can not only utilize the zero-resistance characteristics of the superconducting material to achieve efficient electromagnetic shielding, but also avoid the Joule loss caused by the induced current in the metal shielding layer at room temperature, thereby improving the overall energy efficiency of the superconducting cable.

[0033] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] Figure 1 This is a schematic diagram of the structure of the superconducting cable provided in the embodiment of the present application. Figure 1 As shown, an embodiment of the present application provides a superconducting cable. The superconducting cable 10 can be widely used in scenarios such as urban power grid expansion, new energy power generation grid connection, and industrial high-current power supply. Its high current density and low loss characteristics are particularly suitable for solving key needs such as power transmission bottlenecks in high-load areas and long-distance clean energy transmission. At the same time, it meets the stringent requirements of power supply reliability and electromagnetic compatibility in special occasions, providing important technical support for the construction of new power systems.

[0035] Reference Figure 1As shown, the superconducting cable 10 includes a superconducting conductor layer 200, which is composed of a superconducting conductor. When the temperature, magnetic field, and current are all below their respective critical values, the superconducting conductor exhibits zero resistance characteristics and complete anti-magnetism. When the temperature, magnetic field, and current simultaneously meet the critical conditions, the superconducting conductor changes from a normal state with resistance to a superconducting state with zero resistance and complete anti-magnetism, which can achieve almost lossless current transmission and eliminate the Joule heat loss caused by resistance in traditional conductors. In addition, the current density of superconducting conductors can reach more than 100 times that of copper conductors, and the power transmission capacity is significantly improved under the same cross-sectional area. Moreover, the complete anti-magnetism of superconducting conductors enables them to effectively suppress AC losses in alternating magnetic fields, which is particularly suitable for large-capacity AC power transmission scenarios. Therefore, superconducting conductors have become the core material of the new generation of high-efficiency power transmission systems.

[0036] The superconducting conductor layer 200 can adopt various structural forms. For example, the superconducting conductor layer 200 can be a TSTC conductor (Twisted Stacked Tape Cable), a Q-IS conductor (Quasi-isotropic Strand), a CORC conductor (Conductor on Round Core), etc., which are not specifically limited in this embodiment.

[0037] It should be noted that when the superconducting conductor layer 200 adopts a structure with a central cavity such as a CORC conductor, Figure 1 As shown, the superconducting cable 10 may further include a second support frame 100. As the core support structure of the superconducting cable 10, the second support frame 100 primarily provides mechanical support. Furthermore, the second support frame 100 exhibits excellent flexibility, adapting to the deformation requirements that may occur during installation and operation of the superconducting cable 10, thereby providing a fundamental guarantee for the safe operation of the superconducting cable 10.

[0038] The superconducting conductor can be tightly wrapped around the outer surface of the second support skeleton 100 by spiral winding to form a superconducting conductor layer 200. The winding structure can give the superconducting conductor layer 200 good mechanical adaptability, so that it can effectively cope with the bending stress during the laying of the superconducting cable 10, the electromagnetic vibration during operation, and the deformation caused by thermal cycling, thereby ensuring the long-term reliability of the superconducting conductor layer 200 under complex working conditions. In addition, in order to ensure excellent current transmission performance, the winding angle of the superconducting conductor can be controlled within the range of 30° to 45°. In this way, the optimal distribution of axial and radial currents in the superconducting conductor can be achieved, while optimizing the electromagnetic force balance and critical current density.

[0039] In some embodiments, the second support frame 100 can be a solid structure. For example, a copper stranded wire, formed by twisting multiple copper monofilaments, can be used as the second support frame 100. The dense, solid structure of the copper stranded wire can evenly bear the various mechanical stresses experienced during the operation of the superconducting cable 10. Furthermore, the copper stranded wire's excellent ductility and twisting process characteristics effectively adapt to bending, stretching, and other deformation requirements during the installation of the superconducting cable 10, making it particularly suitable for use in scenarios involving complex paths or frequent dynamic deformation.

[0040] In other embodiments, the second support frame 100 may also be a hollow structure. For example, the second support frame 100 may be a hollow metal tube, such as a stainless steel tube.

[0041] Continue to refer to Figure 1 As shown, the superconducting cable 10 further includes a first support frame 300 and a main insulating layer 400 . The first support frame 300 is disposed outside the superconducting conductor layer 200 , and the main insulating layer 400 is coated on the outside of the first support frame 300 .

[0042] The main insulation layer 400, as a core electrical insulation component, forms a high-voltage electrical insulation barrier, effectively withstanding the potential difference between the superconducting conductor and the external environment, suppressing partial discharge and preventing insulation breakdown. This provides a key guarantee for the safe and stable operation of superconducting cables in high-voltage power transmission scenarios. For example, the main insulation layer 400 can be made of high-performance insulating materials such as cross-linked polyethylene or polytetrafluoroethylene.

[0043] It should be noted that the main insulating layer 400 can be an integrally formed insulating layer. This allows for continuous and uniform coating of the material, avoiding interlayer gaps and interface defects that may occur in traditional wrapping processes. This significantly improves the mechanical strength, voltage resistance, and structural integrity of the main insulating layer 400, ensuring the long-term stable operation of the superconducting cable 10.

[0044] For example, the main insulating layer 400 can be formed using an extrusion molding process. A molten polymer material is continuously coated onto the first support frame 300 through an extrusion die to form the main insulating layer 400. Alternatively, a dense main insulating layer 400 can be formed through multiple impregnation and curing processes. Furthermore, high-pressure spraying technology can be used to achieve uniform deposition of the insulating material. This embodiment does not impose any specific limitations on the method for integrally forming the main insulating layer 400.

[0045] In addition, the thickness of the main insulating layer 400 can be adjusted according to the power transmission requirements of different voltage levels to achieve a dynamic balance between the electric field distribution balance, insulation reliability and structural stability.

[0046] Continue to refer to Figure 1As shown, the first support frame 300 can be a flexible support frame. In the embodiment of the present application, a flexible support frame refers to a support structure that is flexible and can adapt to the bending or dynamic deformation of the superconducting cable 10, and allows moderate elastic deformation while providing mechanical support. For example, the flexible support frame can be a cylindrical tubular structure.

[0047] In this way, the first support frame 300 can maintain the overall structural stability of the cable while withstanding external mechanical stresses such as tension, compression, or vibration loads that the cable may experience during installation, bending, or operation. Its flexibility gives the cable excellent deformation adaptability, ensuring the structural integrity of the main insulation layer 400 while not placing additional mechanical constraints on the internal superconducting conductor layer 200.

[0048] At the same time, as an intermediate support structure, the first support skeleton 300 effectively disperses the mechanical stress between the superconducting conductor layer 200 and the external environment, providing buffering protection for the main insulation layer 400, freeing it from direct bearing of dynamic loads (such as stretching, bending, and impact) during installation or operation. This ensures that the main insulation layer 400 maintains a stable geometric shape under complex operating conditions, preventing structural deformation or damage due to mechanical stress. This lays the structural foundation for its long-term, reliable high-voltage insulation performance and significantly improves the overall mechanical reliability and service life of the superconducting cable 10.

[0049] Furthermore, the first support frame 300 can be a metal frame, thereby effectively improving the electric field distribution of the superconducting conductor layer 200. Specifically, the metal frame, through its continuous conductive properties, can establish a uniform electric potential distribution on the surface of the superconducting conductor layer 200, thereby eliminating local electric field concentration caused by microscopic surface irregularities of the superconducting conductor layer 200 or the winding process. This significantly improves the overall insulation performance of the superconducting cable 10, making the electric field distribution between the superconducting conductor layer 200 and the main insulating layer 400 more uniform and reasonable, avoiding the risk of partial discharge and ensuring the safe and reliable operation of the superconducting cable 10.

[0050] It should be noted that the first support frame 300 is arranged outside the superconducting conductor layer 200 and maintains a certain gap between the first support frame 300 and the superconducting conductor layer 200. This gap can form a first cooling channel b surrounding the superconducting conductor layer 200 (see Figure 1 (as shown). The first cooling channel b is filled with a cooling medium, thus forming an efficient heat exchange path. This arrangement enables direct contact between the superconducting conductor layer 200 and the cooling medium, effectively resolving the problem of reduced heat exchange efficiency caused by the main insulation layer 400 in conventional low-temperature insulation superconducting cables. This ensures that the superconducting conductor maintains a stable superconducting state at operating temperatures, improving the thermal stability of the superconducting cable 10.

[0051] Continue to refer to Figure 1 As shown, the superconducting cable 10 further includes a superconducting shielding layer 500, which is coated with a superconducting material on the outside of the main insulating layer 400. The preparation process of the superconducting shielding layer 500 can be flexibly selected according to engineering requirements. For example, the superconducting shielding layer 500 can be formed by spirally wrapping a superconducting tape to achieve uniform electromagnetic shielding. Alternatively, the superconducting material can be integrally coated on the surface of the main insulating layer 400 through extrusion molding technology, which is not specifically limited in this embodiment.

[0052] The superconducting shielding layer 500 achieves efficient magnetic field shielding through its unique electromagnetic properties. Specifically, based on the principle of electromagnetic induction, when the superconducting conductor layer 200 transmits current, an equal and opposite current is self-induced within the superconducting shielding layer 500. The magnetic field generated by this induced current offsets the magnetic field generated by the superconducting conductor layer 200, achieving a complete electromagnetic shielding effect.

[0053] Compared to metallic shielding layers at room temperature, the zero-resistance properties of the superconducting material in superconducting shielding layer 500 ensure the lossless and continuous existence of induced currents, thereby achieving stable magnetic field cancellation. This maintains perfect shielding effectiveness even under high-current conditions, eliminating the risk of residual magnetic flux leakage interfering with surrounding equipment. This addresses the performance limitations of traditional shielding technology in high-current transmission scenarios, enabling superconducting cable 10 to maintain high-capacity power transmission while meeting the stringent electromagnetic compatibility requirements of complex power grid environments.

[0054] Continue to refer to Figure 1 As shown, the superconducting cable 10 further includes an insulation structure 600, which can effectively block the heat from the external environment of the superconducting cable 10 from being transferred to the interior of the superconducting cable 10, ensuring that the superconducting conductor layer 200 and the superconducting shielding layer 500 can operate stably in an extremely low temperature environment, ensuring that the superconducting conductor is continuously and stably in a zero-resistance state, thereby maintaining the low-loss power transmission performance of the superconducting cable 10.

[0055] The thermal insulation structure 600 is disposed outside the superconducting shielding layer 500 in a non-contact manner. This arrangement creates an annular gap between the thermal insulation structure 600 and the superconducting shielding layer 500, thereby forming a second cooling channel c. The second cooling channel c can be filled with a cooling medium. During operation, the superconducting shielding layer 500 generates heat due to effects such as electromagnetic induction. The cooling medium in the second cooling channel c circulates and conducts away the heat generated by the superconducting shielding layer 500. This achieves heat exchange and cooling of the superconducting shielding layer 500, ensuring stable operation of the superconducting shielding layer 500.

[0056] It should be noted that the first cooling channel b and the second cooling channel c can be flexibly configured as independent loops or connected circulation loops according to actual needs. In some embodiments, the first cooling channel b and the second cooling channel c can each form an independent circulation loop and be equipped with a dedicated cooling medium inlet and outlet and a circulation pump. With such a setting, differentiated temperature control and flow regulation of the first cooling channel b and the second cooling channel c can be achieved. In addition, the design of the independent loop also facilitates fault isolation and maintenance. When one of the cooling cavities needs to be repaired, the other cooling cavity can still operate normally, ensuring that the superconducting cable 10 can maintain stable temperature control and efficient thermal management during operation.

[0057] In other embodiments, the first cooling channel b and the second cooling channel c can also be interconnected to form a closed-loop circulation circuit. For example, a fluid diversion chamber (not shown in the figure) can be provided at the end or segment connection of the superconducting cable 10. A guide hole (not shown in the figure) is provided in the fluid diversion chamber, and the first cooling channel b and the second cooling channel c can be interconnected through the guide hole. After the cooling medium flows out of the first cooling channel b, it is guided into the second cooling channel c through the fluid diversion chamber to complete the circulation flow and improve the utilization efficiency of the cooling medium.

[0058] Of course, when the second support skeleton 100 is a hollow structure, at this time, while ensuring the necessary rigidity, the hollow cavity inside the second support skeleton 100 can be filled with a cooling medium to form a third cooling channel a, thereby realizing the functional integration of the support structure and the cooling channel, and helping to improve the heat exchange efficiency of the superconducting cable 10.

[0059] The third cooling channel a may also be configured as an independent circuit. Alternatively, the third cooling channel a may also form a connected circulation circuit together with the first cooling channel b and the second cooling channel c.

[0060] When the first cooling channel b, the second cooling channel c, and the third cooling channel a together form a connected circulation loop, the flow direction of the cooling medium must be optimized based on the spatial structural characteristics of each channel. By rationally planning the flow path, the pressure gradient of each channel is balanced to avoid excessive pressure drop or localized stagnation caused by differences in flow channel cross-sectional area. Given the relatively small space of the third cooling channel a, its flow direction design can be coordinated with that of the first cooling channel b or the second cooling channel c. The larger space of the first cooling channel b or the second cooling channel c can compensate for the flow resistance restriction of the third channel, avoiding uneven flow distribution caused by cross-sectional differences.

[0061] For example, the third cooling channel and the second cooling channel can be connected to the first cooling channel respectively. For example, the cooling medium in the third cooling channel a can flow in the same direction as the cooling medium in the first cooling channel b, and then flow out of the second cooling channel c.

[0062] Alternatively, the third cooling channel and the first cooling channel may be connected to the second cooling channel respectively. For example, the cooling medium in the third cooling channel a and the cooling medium in the second cooling channel c flow in the same direction and eventually flow out of the first cooling channel b. This embodiment does not impose any specific restrictions on this.

[0063] Continue to refer to Figure 1 As shown, the outer side of the superconducting shielding layer 500 may also be coated with an outer insulating layer 700. The outer insulating layer 700 can form a reliable dielectric barrier between the superconducting shielding layer 500 and the thermal insulation structure 600. Thus, the outer insulating layer 700 can block the leakage path of induced current that may be generated during the operation of the superconducting shielding layer 500 to the thermal insulation structure 600. At the same time, the outer insulating layer 700 can also eliminate the risk of insulation breakdown caused by partial discharge or electric field distortion by optimizing the electric field distribution on the surface of the superconducting shielding layer 500, thereby preventing short circuit failures between the superconducting shielding layer 500 and the thermal insulation structure 600.

[0064] The outer insulating layer 700 can be made of an insulating material with high breakdown field strength, low dielectric loss, and resistance to low-temperature deformation. For example, the outer insulating layer 700 can be made of a high-performance insulating material such as polytetrafluoroethylene, cross-linked polyethylene, polyimide, or an epoxy-based composite material, and can be coated on the outer surface of the superconducting shielding layer 500 by spiral wrapping or extrusion molding. This embodiment does not impose any specific limitations on this.

[0065] Continue to refer to Figure 1 As shown, the insulation structure 600 may include an insulation inner tube 610, an insulation layer 620 and an insulation outer tube 630 arranged in sequence from the inside to the outside. Among them, the insulation inner tube 610 is directly adjacent to the second cooling channel c, and mainly undertakes the functions of mechanical support and preliminary thermal isolation. The insulation inner tube 610 needs to maintain structural strength in a low temperature environment to avoid deformation due to the pressure of the cooling medium or external stress, and at the same time reduce the external heat entering the cooling channel through conduction. Therefore, the insulation inner tube 610 can be made of a metal or composite material that is resistant to low temperatures, has low thermal conductivity and is corrosion-resistant. For example, the material of the insulation inner tube 610 can be selected from 304 stainless steel with both strength and low temperature resistance or lightweight glass fiber reinforced plastic with low thermal conductivity to balance mechanical properties and insulation requirements.

[0066] The thermal insulation layer 620 can be composed of multiple layers of thermal insulation material to form a continuous thermal barrier that effectively inhibits heat intrusion caused by thermal radiation, heat conduction, and gas convection, thereby maintaining the stability of the low-temperature environment inside the superconducting cable 10. In the embodiments of the present application, the thermal insulation material refers to a functional material used to prevent or significantly reduce heat transfer.

[0067] Exemplarily, the thermal insulation layer 620 may include 20 to 50 layers of alternating metal reflective layers (not shown) and spacer layers (not shown). The metal reflective layer may be made of aluminum foil or metallized polyester film with high reflectivity, while the spacer layer may be made of low thermal conductivity materials such as glass fiber paper or polyimide film. To further enhance the thermal insulation effect, porous thermal insulation materials (not shown) such as silica aerogel or polyurethane foam may be provided on the outside of the metal reflective layer and the spacer layer. The porous thermal insulation material can effectively suppress the convective heat transfer generated by the movement of gas molecules through its unique micro-nano pore structure, and further block heat conduction, thereby providing reliable thermal protection for the stable operation of the superconducting cable 10.

[0068] As the outermost layer of the insulation structure 600, the insulation outer tube 630 must withstand external mechanical loads (such as soil pressure, tensile or bending stress during burial) while resisting erosion from environmental factors such as moisture, ultraviolet rays, and corrosive substances. Therefore, the insulation outer tube 630 can be made of a high-strength, weather-resistant polymer or metal material. For example, the insulation outer tube 630 can be made of high-density polyethylene (HDPE), which is corrosion-resistant, low-temperature-resistant, and easy to process, or a glass fiber-reinforced composite material that combines rigidity and aging resistance, to ensure the long-term stable operation of the insulation structure 600 in complex environments.

[0069] It should be noted that a vacuum layer 640 is formed between the inner tube 610 and the outer tube 630 of the heat-insulating tube. In the embodiment of the present application, the vacuum layer 640 is formed by removing the air between the inner tube 610 and the outer tube 630 of the heat-insulating tube and the internal pressure is lower than 10 -3 Pa high vacuum environment. Since the heat conduction of gas molecules depends on the energy transfer of intermolecular collisions, and the density of gas molecules in a vacuum environment is extremely low (close to a molecular-free state), this heat conduction path based on molecular collisions is almost completely cut off. At the same time, the vacuum environment also eliminates the convective heat transfer caused by gas flow, thereby significantly reducing the penetration of heat from the external environment into the interior of the superconducting cable 10. Therefore, the vacuum layer 640 can effectively maintain a low-temperature environment inside the superconducting cable 10, significantly reduce the cold loss of the cooling medium, and provide key temperature protection for the efficient operation of the superconducting conductor layer 200 and the superconducting shielding layer 500.

[0070] Continue to refer to Figure 1As shown, the superconducting cable 10 further includes a sheath layer 800, which is disposed on the outer periphery of the insulation structure 600 to protect the superconducting cable 10 from physical damage. Furthermore, the sheath layer 800 has properties such as waterproofing, shear resistance, and tensile strength, thereby extending the service life of the superconducting cable 10. Furthermore, the sheath layer 800 has strong impact resistance and can withstand various mechanical stresses that may be encountered during the operation of the superconducting cable 10. For example, the sheath layer 800 can be formed by winding a polypropylene rope, or the outer sheath layer 800 can be formed by extruding polyethylene. As long as the sheath layer 800 has good flexibility, chemical resistance, and wear resistance, the present embodiment does not impose any specific restrictions on this.

[0071] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0072] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A superconducting cable, characterized in that: include: The superconducting conductor layer, the first supporting frame, the main insulating layer, the superconducting shielding layer and the thermal insulation structure are arranged in sequence from the inside to the outside; The superconducting conductor layer is used for power transmission; A first cooling channel is formed between the superconducting conductor layer and the first supporting frame, and the first cooling channel is filled with a cooling medium; A second cooling channel is formed between the superconducting shielding layer and the thermal insulation structure, and the second cooling channel is filled with a cooling medium.

2. The superconducting cable according to claim 1, wherein The main insulating layer is an integrally formed insulating layer.

3. The superconducting cable according to claim 1, wherein Also includes: A second supporting frame is provided inside the superconducting conductor layer.

4. The superconducting cable according to claim 3, characterized in that The second supporting frame is a solid structure; Alternatively, the second supporting skeleton is a hollow structure and forms a third cooling channel, and the third cooling channel is filled with a cooling medium.

5. The superconducting cable according to claim 4, characterized in that The second supporting frame is a hollow structure, and the third cooling channel and the second cooling channel are respectively connected to the first cooling channel; Alternatively, the third cooling channel and the first cooling channel are respectively communicated with the second cooling channel.

6. The superconducting cable according to claim 1, wherein The first supporting frame is a flexible metal supporting frame.

7. The superconducting cable according to any one of claims 1 to 6, characterized in that: An outer insulating layer is further provided outside the superconducting shielding layer, and the second cooling channel is formed between the outer insulating layer and the thermal insulation structure.

8. The superconducting cable according to any one of claims 1 to 6, characterized in that: The heat-insulating structure comprises a heat-insulating inner pipe, a heat-insulating layer and a heat-insulating outer pipe which are sequentially arranged from the inside to the outside.

9. The superconducting cable according to claim 8, characterized in that A vacuum layer is formed between the inner tube of the thermal insulation tube and the outer tube of the thermal insulation tube.

10. The superconducting cable according to any one of claims 1 to 6, characterized in that: The superconducting cable further comprises: Sheath layer: The sheath layer is arranged on the outside of the thermal insulation structure.

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