Electricity-hydrogen co-transmission superconducting cable based on composite framework and control method

Abstract

The invention belongs to the technical field of superconducting cables, and discloses an electricity-hydrogen co-transmission superconducting cable based on a composite framework and a control method. The electric-hydrogen co-transmission superconducting cable comprises a central liquid hydrogen channel, a first liquid hydrogen transmission channel, a second liquid hydrogen transmission channel, a second liquid hydrogen transmission channel and an electric-hydrogen co-transmission superconducting cable which are sequentially arranged from inside to outside, the cross section of the composite conductive framework is annular; a plurality of embedding grooves are formed in the composite conductive framework; a single or a plurality of superconducting wires are embedded in the embedding groove; an insulation system; a second liquid hydrogen conveying channel is formed in the outer-layer liquid hydrogen channel; and an outer layer protection structure. The annular structure of the composite conductive framework is matched with the design of the embedding groove, so that the superconducting wire can be embedded in the groove, tight integration of the superconducting wire and the supporting framework is achieved, compared with a traditional surface winding structure, the mechanical coupling stability is remarkably improved, electromagnetic force, thermal stress and external vibration can be effectively resisted, and the mechanical damage risk of the strip can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of superconducting cable technology, and specifically relates to a superconducting cable for electro-hydrogen co-transmission based on a composite skeleton and a control method thereof. Background Technology

[0002] The hydrogen-electric co-transmission superconducting cable is an integrated energy transmission equipment. Its core feature lies in its ability to synergistically transport liquid hydrogen and electrical energy. Its significant advantages in improving overall energy utilization efficiency and intensively utilizing corridor resources have made it one of the cutting-edge research directions in the energy field. Its typical structure consists of a central liquid hydrogen channel serving as the cryogenic medium and a superconducting conductive layer surrounding it. The liquid hydrogen flowing through the central channel serves a dual function as both a cooling carrier and an energy medium: on the one hand, it provides a continuous and stable cryogenic heat sink for the superconducting layer, ensuring its operating temperature remains below the critical temperature to maintain a stable superconducting state; on the other hand, it enables the transmission of hydrogen energy itself.

[0003] In existing designs for co-conducting hydrogen and electricity superconducting cables, a metal frame (usually copper or aluminum alloy) is commonly used outside the central channel to provide mechanical support for the superconducting tape and improve heat conduction. Figure 1 As shown, this structure involves directly spirally winding a high-temperature superconducting tape (such as rare-earth barium copper oxide (REBCO) or MgB2 tape) onto the outer surface of a solid or hollow cylindrical copper skeleton. The disadvantages of this structure are: the superconducting tape is directly exposed beneath the insulating layer, and heat conduction occurs only through surface contact, resulting in significant contact thermal resistance; more importantly, under electromagnetic forces, thermal stress, and external vibrations, the tape may experience relative displacement or friction with the skeleton, posing a risk of mechanical damage or performance degradation to the tape over long-term operation.

[0004] The superconducting conductor structure in existing co-conducting hydrogen superconducting cables fails to fundamentally solve the problems of high-reliability mechanical coupling and low thermal resistance heat conduction between the superconducting material and the supporting skeleton. During cable operation, localized temperature rises due to uneven current distribution are common phenomena. These cables cannot respond to such localized, dynamic temperature changes, nor can they proactively enhance cooling at this point in the early stages of temperature rise to suppress thermal runaway. They lack a distributed, early adaptive adjustment mechanism based on physical feedback. The unstable contact state between the superconducting tape and the skeleton, along with the insulation layer, becomes a weak link affecting the cable's current-carrying capacity, mechanical life, and operational reliability. Summary of the Invention

[0005] The purpose of this invention is to provide a superconducting cable for co-transporting hydrogen based on a composite skeleton and a control method thereof, so as to solve at least one of the technical problems existing in the current superconducting cable for co-transporting hydrogen, such as poor mechanical coupling between the superconducting tape and the supporting skeleton, poor thermal contact, and insufficient structural stability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a superconducting cable for co-transporting hydrogen based on a composite framework, comprising, from the inside out: A central liquid hydrogen channel, within which a first liquid hydrogen transport channel is formed; A composite conductive framework has a ring-shaped cross-section; the composite conductive framework has multiple embedding slots; and one or more superconducting wires are embedded in the embedding slots. Insulation system; An outer liquid hydrogen channel, within which a second liquid hydrogen transport channel is formed; Outer protective structure.

[0007] A further improvement of the present invention is that: multiple concave insert grooves are formed in the annular wall of the composite conductive skeleton along the axial or helical direction.

[0008] A further improvement of the present invention is that: the mounting groove is fitted with a superconducting wire through a limiting structure; the limiting structure is a mechanical fixing element set in the mounting groove, which has an Ω-shaped cross section or a crescent-shaped cross section, and forms a covering contact with the outer surface of the superconducting wire for initial fixing.

[0009] A further improvement of the present invention is that the superconducting wire is fixed in the mounting groove by interference fit, brazing or conductive adhesive bonding.

[0010] A further improvement of the present invention is that the multiple embedding slots are arranged in two or more layers along the radial direction of the electro-hydrogen co-transmission superconducting cable, and the embedding slots in adjacent layers are staggered.

[0011] A further improvement of the present invention is that: the central liquid hydrogen channel is composed of a bellows; the inner wall of the composite conductive skeleton and the outer wall of the bellows are metallurgically bonded by high-temperature brazing.

[0012] A further improvement of the present invention is that the insulation system includes an inner semiconductor layer, a main insulation layer and an outer semiconductor layer arranged sequentially from the inside to the outside.

[0013] A further improvement of the present invention is that a shielding layer with a copper strip wrapping structure is provided between the outer semiconductor layer and the outer liquid hydrogen channel.

[0014] A further improvement of the present invention is that the outer protective structure includes an insulation layer and an outer protective sleeve arranged from the inside to the outside.

[0015] A further improvement of the present invention is that: the corrugated pipe forms the outer wall of the central liquid hydrogen channel, which is used to compensate for the axial thermal stress of the cable caused by temperature changes.

[0016] A further improvement of the present invention is that: an inner semiconductor layer is covered on the outside of the composite conductive framework; a main insulating layer is covered on the outside of the inner semiconductor layer; an outer semiconductor layer is covered on the outside of the main insulating layer; a shielding layer is covered on the outside of the outer semiconductor layer; an outer liquid hydrogen channel is disposed on the outside of the shielding layer; a heat insulation layer is covered on the outside of the outer liquid hydrogen channel; and an outer protective sleeve is covered on the outside of the heat insulation layer.

[0017] A further improvement of the present invention is that the bellows is made of stainless steel, which can withstand the internal pressure of liquid hydrogen while ensuring axial flexibility.

[0018] A further improvement of the present invention is that the composite conductive skeleton is made of a metal material with high thermal conductivity, such as copper or aluminum alloy.

[0019] A further improvement of the present invention is that the cross-sectional shape of the mounting groove is adapted to the cross-sectional shape of the superconducting wire to achieve surface contact.

[0020] A further improvement of the present invention is that the number of the embedding slots is 6 to 24, and they are evenly distributed within the annular wall of the composite conductive skeleton.

[0021] A further improvement of the present invention is that at least one sidewall of at least a portion of the mounting groove is an adaptive deformable wall; the adaptive deformable wall is composed of a functional material layer that is sensitive to temperature and can produce thermal deformation, so that the width of the mounting groove can be adaptively changed according to the temperature change at its location, thereby applying dynamically changing contact pressure to the superconducting wire in the mounting groove.

[0022] A further improvement of the present invention is that: the adaptive deformable wall is a bimetallic composite layer or a composite layered structure composed of two or more materials with different coefficients of thermal expansion; in particular, the adaptive deformable wall is a composite layered structure composed of two or more materials with significantly different coefficients of thermal expansion.

[0023] A further improvement of the present invention is that the adaptive deformable wall is configured such that when the local temperature rises, the wall of the adaptive deformable wall bends or expands inward toward the inset of the fitting groove.

[0024] A further improvement of the present invention is that, of the two materials constituting the adaptive deformable wall, the linear thermal expansion coefficient of the material facing the inside of the groove is greater than that of the material facing away from the inside of the groove.

[0025] A further improvement of the present invention is that the mounting groove is parallel to the cable axis and is arranged as a straight groove.

[0026] A further improvement of the present invention is that the shielding layer is made of copper shielding layer with embedded superconducting wires.

[0027] A further improvement of the present invention is that the embedding groove is arranged in a spiral structure along the annular wall of the composite conductive skeleton to achieve natural transposition of the superconducting wire and reduce AC loss.

[0028] A further improvement of the present invention is that the deformation response temperature of the adaptive deformable wall matches the critical temperature range of the superconducting wire.

[0029] Secondly, the present invention provides a control method for a composite-framed electro-hydrogen co-transport superconducting cable, comprising: The control center liquid hydrogen channel and the outer liquid hydrogen channel are interconnected to form a parallel cooling flow path, which operates under the same pressure. Alternatively, the control center liquid hydrogen channel and the outer liquid hydrogen channel can operate independently at different flow rates and pressures.

[0030] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a superconducting cable for co-transporting hydrogen based on a composite skeleton, comprising, from the inside out: a central liquid hydrogen channel, within which a first liquid hydrogen transport channel is formed; a composite conductive skeleton with an annular cross-section; multiple embedding slots in the composite conductive skeleton; one or more superconducting wires embedded in the embedding slots; an insulation system; an outer liquid hydrogen channel, within which a second liquid hydrogen transport channel is formed; and an outer protective structure. This invention employs a dual liquid hydrogen transport channel design with a central liquid hydrogen channel and an outer liquid hydrogen channel. This achieves efficient hydrogen transport while the dual channels form a synergistic cooling system, providing a continuous and stable low-temperature heat sink for the superconducting wire, ensuring superconducting stability. The annular structure of the composite conductive skeleton, combined with the embedded groove design, allows the superconducting wire to be embedded within the groove, achieving a tight integration between the superconducting wire and the supporting skeleton. Compared to traditional surface winding structures, this significantly improves mechanical coupling stability, effectively resisting electromagnetic forces, thermal stress, and external vibrations, reducing the risk of mechanical damage to the strip. The embedded contact between the superconducting wire and the composite conductive skeleton increases the contact area, significantly reducing contact thermal resistance, allowing the liquid hydrogen cooling capacity to be efficiently transferred to the superconducting wire through the high thermal conductivity skeleton, improving cooling efficiency. The orderly arrangement of the multi-layer structure (central liquid hydrogen channel - composite conductive skeleton - insulation system - outer liquid hydrogen channel - outer protective structure) achieves functional integration of electric and hydrogen co-transport, balancing the safety of electrical energy transmission, the sealing of hydrogen energy transport, and the overall structural protection, improving comprehensive energy utilization efficiency and saving corridor resources.

[0031] Furthermore, when the embedding groove of the present invention is opened along the axial direction, it facilitates the batch embedding and positioning of superconducting wires, reduces processing difficulty, and ensures the straight arrangement of superconducting wires along the cable axis, reducing stress concentration in the wires. When the embedding groove is opened along the spiral direction, it allows the superconducting wires to naturally form a spiral arrangement after embedding, realizing the natural transposition of the superconducting wires, effectively balancing the inductance of each wire, and minimizing the circulating current loss inside the conductor, which is especially suitable for AC transmission network scenarios. The concave embedding groove structure can form a circumferential limit on the superconducting wires, further improving the tightness of the connection between the wires and the composite conductive skeleton, avoiding displacement or friction of the wires during operation, and ensuring structural stability and operational reliability.

[0032] Furthermore, this invention achieves the embedding and fixing of superconducting wires through a limiting structure, which can precisely match the fixing force according to the specifications of the superconducting wires, avoiding damage to the wires due to excessive tightness or poor contact due to excessive looseness; the limiting structure with an Ω-shaped or crescent-shaped cross-section can form a covering contact with the outer surface of the superconducting wires, increasing the fixing contact area and improving the reliability of mechanical fixing, effectively resisting displacement tendencies caused by external vibrations, electromagnetic forces, etc.; the covering contact structure can also help enhance the heat conduction path between the superconducting wires and the composite conductive skeleton, further reducing contact thermal resistance and ensuring the uniformity of low-temperature cooling effect; the detachable or adaptable design of the mechanical fixing components facilitates the installation, inspection and replacement of superconducting wires, improving the convenience of cable maintenance.

[0033] Furthermore, the interference fit method of this invention enables a tight fit between the superconducting wire and the mounting groove, eliminating the need for additional auxiliary fixing components, simplifying the structural design, and ensuring good mechanical stability and thermal conductivity. The brazing method enables the superconducting wire and the composite conductive skeleton to form a metallurgical bond with high bonding strength and extremely high mechanical reliability, completely avoiding relative displacement. Moreover, the thermal resistance of the metallurgical bonding surface is extremely low, enabling efficient transfer of cold energy. The conductive adhesive bonding method is simple to operate and suitable for fixing superconducting wires of different cross-sectional specifications. The conductive adhesive can ensure the conductive continuity between the wire and the skeleton, assist in forming a shunt path when the superconductor becomes unstable, and also has a certain buffering effect, reducing thermal stress damage to the wire. Multiple fixing methods can be flexibly selected according to actual application scenarios (such as current carrying capacity requirements, maintenance requirements, and cost budget), improving the adaptability of cable design.

[0034] Furthermore, the embedded slots of this invention are arranged in multiple radial layers, which can integrate more superconducting wires within a limited space of the composite conductive skeleton, significantly increasing the total current carrying capacity of the cable and meeting the needs of high-capacity power transmission. The staggered arrangement of the embedded slots in adjacent layers can avoid electromagnetic interference between adjacent wires, balance the electric and magnetic field distribution inside the conductor, and reduce electromagnetic losses. The staggered arrangement makes the superconducting wires more evenly distributed within the skeleton and more evenly stressed. When subjected to external vibration or thermal stress, it can avoid stress concentration in local areas and improve the mechanical durability of the overall structure. The multi-layer staggered arrangement structure provides flexible design space for expanding the current carrying capacity of the cable. The capacity can be upgraded by increasing the number of layers or the number of slots in each layer without significantly modifying the overall structure.

[0035] Furthermore, the corrugated tube of this invention forms the central liquid hydrogen channel, possessing excellent axial flexibility. This effectively compensates for the axial thermal stress generated by the huge temperature difference between low-temperature cooling and normal-temperature operation of the cable, preventing damage to the core structure (such as the composite conductive skeleton and superconducting wire) due to thermal expansion and contraction, and improving the reliability of the cable for long-distance applications. The stainless steel corrugated tube, while ensuring flexibility, can withstand the internal pressure of liquid hydrogen, ensuring the sealing and safety of liquid hydrogen transportation. The composite conductive skeleton and the corrugated tube are metallurgically bonded through high-temperature brazing, resulting in high joint strength and extremely low thermal resistance. On the one hand, this ensures that the cooling capacity of the central liquid hydrogen channel can be quickly transferred to the composite conductive skeleton through the corrugated tube, thereby efficiently cooling the superconducting wire. On the other hand, it forms an integrated structure, improving overall mechanical stability and preventing sealing failure or interruption of heat conduction caused by relative displacement.

[0036] Furthermore, the inner semiconductor layer of this invention can eliminate the air gap between the composite conductive framework and the main insulating layer, balance the electric field distribution, avoid local electric field concentration leading to insulation breakdown, and improve insulation reliability. The main insulating layer, as the core insulating barrier, can effectively isolate the superconductor from the external structure, prevent power leakage, ensure power transmission safety, and adapt to low-temperature operating environments, avoiding insulation performance degradation at low temperatures. The outer semiconductor layer can balance the electric field between the main insulating layer and the outer structure, reduce corona loss on the insulating surface, and also play a buffer protection role, preventing the main insulating layer from being damaged by external mechanical forces. The three-layer insulation system of inner semiconductor layer, main insulating layer, and outer semiconductor layer works synergistically to form a complete insulation protection system, taking into account electric field balance, insulation reliability, and mechanical protection, and adapting to the complex operating environment (low temperature, high pressure, vibration) in the scenario of co-transmission of electricity and hydrogen.

[0037] Furthermore, the shielding layer of the copper strip wrapping structure of this invention possesses excellent conductivity, effectively shielding electromagnetic radiation generated by superconductors and preventing electromagnetic interference to external structures (such as the outer liquid hydrogen channel and protective structure), thus ensuring the normal operation of surrounding equipment. The shielding layer can also serve as a discharge channel for fault current, quickly diverting the fault current to the ground when an insulation fault occurs in the cable, reducing the risk of fault expansion and improving cable operation safety. The copper strip wrapping structure also provides a certain degree of mechanical protection, buffering the impact of external pressure on the internal insulation system and protecting the main insulation layer from damage. The shielding layer is positioned between the outer semiconductor layer and the outer liquid hydrogen channel, creating an isolation buffer between the insulation system and the cooling channel, preventing the low temperature of the liquid hydrogen channel from directly thermally impacting the insulation layer and ensuring stable insulation performance.

[0038] Furthermore, the insulation layer of this invention can effectively block external heat from entering the inner liquid hydrogen channel area, reducing liquid hydrogen evaporation loss, ensuring the low temperature state of liquid hydrogen, and simultaneously reducing the energy consumption of the cooling system and improving energy utilization efficiency. The outer protective sleeve has excellent mechanical strength and environmental resistance (such as weather resistance, corrosion resistance, and wear resistance), which can effectively protect the core internal structure of the cable (such as liquid hydrogen channels, composite conductive skeleton, and insulation system) from damage caused by external mechanical impact, chemical corrosion, and ultraviolet radiation. The synergistic effect of the insulation layer and the outer protective sleeve forms a complete external protection system, taking into account both low-temperature insulation and mechanical protection functions, extending the service life of the cable, and reducing operation and maintenance costs. The vacuum multilayer and other insulation layer structures, combined with the outer protective sleeve, can further improve the insulation effect and adapt to the application needs of different environmental temperature scenarios (such as high-temperature areas and extremely cold areas).

[0039] Furthermore, this invention achieves a tight integration of the superconducting material and the supporting skeleton by directly embedding cylindrical superconducting wires into specially designed grooves in the composite conductive skeleton. This forms a robust mechanical interconnect structure that effectively resists electromagnetic forces, thermal stress, and external vibrations, significantly improving the mechanical reliability and lifespan of the cable. The large-area close contact between the superconducting wires and the metal skeleton significantly reduces contact thermal resistance, allowing the cooling capacity of liquid hydrogen to be efficiently and directly transferred to each superconducting wire through the highly thermally conductive skeleton. This ensures temperature uniformity and stability in the superconducting state, resulting in high cooling efficiency. This structure allows for the integration of multiple superconducting wires within a limited skeleton space. By flexibly designing the number and arrangement of the embedding grooves, the total current carrying capacity of the cable can be easily adjusted and expanded to meet the capacity requirements of different application scenarios.

[0040] Furthermore, by integrating a corrugated tube on the inner side, the cable achieves excellent axial flexibility and thermal stress compensation capabilities, which can safely absorb the cumulative expansion and contraction caused by huge temperature differences in long-distance applications. This fundamentally protects the entire core structure, including the composite conductive skeleton and superconducting wire, and greatly improves the macroscopic mechanical reliability and lifespan of the cable.

[0041] Furthermore, the spirally arranged insert grooves of this invention enable the superconducting wires to undergo natural transposition during cable manufacturing, effectively balancing the inductance of each wire and minimizing circulating current losses within the conductor.

[0042] Furthermore, the composite conductive skeleton of this invention uses highly conductive copper or aluminum alloy, which can provide a low-resistance shunt path for superconducting current in the event of superconducting instability, protecting the superconducting wire from damage. Furthermore, this invention can construct the sidewalls of the embedding groove as adaptive deformable walls made of bimetallic sheets or the like. This structure endows the cable with a passive, distributed early thermal runaway suppression capability. When a superconducting wire experiences a slightly higher local temperature due to current deviation, the sidewall of the groove containing it will automatically bend and deform inwards due to heat, thereby generating adaptive compression on the wire.

[0043] Furthermore, this adaptive extrusion produces a dual stabilizing effect. On a mechanical-thermal level, extrusion strengthens the contact between the wire and the high thermal conductivity framework, significantly reducing the contact thermal resistance of this "hot spot," thereby improving liquid hydrogen cooling efficiency and accelerating hot spot dissipation. On a potential electrical level, the slight geometric changes in the wire caused by extrusion may modulate its local inductance, which helps promote the natural homogenization of current among parallel wires, fundamentally alleviating uneven current distribution.

[0044] Furthermore, this structure achieves true self-sensing, self-decision-making, and self-execution, requiring no external energy or control system throughout the entire process. Its response is naturally coupled with the temperature field, and is rapid and direct, constructing a built-in "immune system" for superconducting cables based on the intrinsic properties of the materials, greatly enhancing the inherent self-stability and reliability of cable operation.

[0045] Furthermore, this invention provides a composite structure that tightly integrates the superconducting material with the supporting framework and introduces an inner corrugated tube, fundamentally solving the problems of low mechanical stability and low thermal conductivity caused by the surface winding of superconducting tapes or simple groove laying in the prior art; through a unique embedded design, a large-area close contact is achieved between the superconducting wire and the composite conductive framework, significantly reducing contact thermal resistance and ensuring maximum liquid hydrogen cooling efficiency; thus constructing an electro-hydrogen co-transport system with excellent mechanical strength, high-efficiency cooling performance and flexible current-carrying capacity, meeting the diverse needs of different application scenarios for energy transmission capacity and reliability.

[0046] Furthermore, this invention achieves a tight integration of the superconducting material and the supporting framework by directly embedding the superconducting wire into a specially designed groove in the composite conductive framework, forming a robust mechanical interconnect structure. Experiments show that this structure can effectively resist electromagnetic forces, thermal stress, and external vibrations, with mechanical reliability more than three times higher than that of traditional winding structures, and a significantly extended service life.

[0047] Furthermore, the large-area, close contact between the superconducting wire and the metal skeleton in this invention reduces the contact thermal resistance to less than 20% of that in conventional structures. Cooling efficiency test data shows that the overall thermal conductivity of this structure is improved by more than 35% compared to existing wire-groove-laid structures, ensuring optimal temperature uniformity and stability in the superconducting state.

[0048] Furthermore, by introducing an inner corrugated pipe, this invention systematically solves the problem of axial thermal stress caused by huge temperature differences during the cooling and operation of long-distance cables, protecting core components such as composite conductive skeletons and superconducting wires from mechanical damage.

[0049] Furthermore, this invention, through the design of a spiral embedding groove, can naturally achieve the transposition of superconducting wires, automatically balance inductance, and significantly reduce AC losses, making it particularly suitable for future AC power transmission network applications. It provides a low-resistance shunt path without dead zones for the large currents generated by timeouts, with rapid response and effective protection of valuable superconducting wires from damage.

[0050] Furthermore, the embedded composite conductor structure of this invention solves the problems of local fixation and thermal contact in superconducting cables, while the inner corrugated tube solves the problem of macroscopic mechanical integrity of the entire cable system. The synergy of these two features results in an order-of-magnitude improvement in the mechanical reliability of the cable compared to traditional structures, and a significantly extended service life.

[0051] This invention provides a control method for a superconducting electro-hydrogen co-transmission cable based on a composite skeleton. It enables the interconnection of two liquid hydrogen channels to form a parallel cooling flow path and operate under the same pressure, increasing the liquid hydrogen flow rate, improving cooling efficiency, ensuring uniform cooling of the superconducting wire, and creating cooling redundancy. If one channel fails, the other can continue to provide cooling, improving system reliability. Controlling the two liquid hydrogen channels independently, operating them at different flow rates and pressures, allows for precise control of cooling accuracy. For example, the liquid hydrogen flow rate of the corresponding channel can be adjusted according to the heat generation of different sections of the cable, improving the energy efficiency of the cooling system. Simultaneously, it allows for flexible allocation of hydrogen energy delivery to meet the differentiated hydrogen energy needs of different users. The two control methods can be flexibly switched according to actual operating scenarios (such as changes in transmission capacity, fluctuations in hydrogen energy demand, and changes in ambient temperature), improving the operational flexibility and adaptability of the electro-hydrogen co-transmission system and ensuring stable and efficient operation under complex conditions. Attached Figure Description

[0052] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0053] Figure 1 This is a schematic diagram of the cross-section of a surface-wound electro-hydrogen co-transport superconducting cable in the prior art.

[0054] Figure 2 This is a schematic diagram of the overall cross-sectional structure of a superconducting cable based on a composite skeleton for co-transporting hydrogen according to an embodiment of the present invention.

[0055] Figure 3 This is a cross-sectional schematic diagram of the composite conductive skeleton of the present invention, showing the distribution of the mounting slots.

[0056] Figure 4 This is a three-dimensional structural diagram of the composite conductive skeleton of the present invention, showing the arrangement of the spiral embedding grooves.

[0057] Figure 5 This is a partially enlarged view of the single superconducting wire of the present invention embedded in the composite conductive skeleton groove.

[0058] Figure 6 This is a schematic diagram of the three-dimensional structure of a composite skeleton-based electro-hydrogen co-transmission superconducting cable according to Embodiment 1 of the present invention.

[0059] Figure 7 This is a schematic diagram of the three-dimensional structure of a composite skeleton-based electro-hydrogen co-transmission superconducting cable in Embodiment 2 of this invention.

[0060] In the figure: central liquid hydrogen channel 1, corrugated pipe 101, composite conductive skeleton 2, embedding groove 201, superconducting wire 3, inner semiconductor layer 4, main insulating layer 5, outer semiconductor layer 6, shielding layer 7, outer liquid hydrogen channel 8, heat insulation layer 9, outer protective sleeve 10, limiting structure 11. Detailed Implementation

[0061] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0062] In the description of this invention, it should be understood that the terms "center," "inner," "outer," "axial," "radial," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0063] To address the problem of loose bonding between superconducting tape and supporting structure in existing electro-hydrogen co-transmission superconducting cables, this invention provides an electro-hydrogen co-transmission superconducting cable based on a composite skeleton, comprising a central liquid hydrogen channel 1, a composite conductive skeleton 2, superconducting wire 3, an insulation system, an outer liquid hydrogen channel 8, and an outer protective structure.

[0064] Please see Figure 2 As shown, an embodiment of the present invention provides an electro-hydrogen co-transmission superconducting cable based on a composite skeleton, which, from the inside out, comprises: a central liquid hydrogen channel 1, a composite conductive skeleton 2, an inner semiconductor layer 4, a main insulation layer 5, an outer semiconductor layer 6, a shielding layer 7, an outer liquid hydrogen channel 8, a heat insulation layer 9, and an outer protective sleeve 10.

[0065] The central liquid hydrogen channel 1 is composed of a bellows 101. The composite conductive framework 2, serving as the core support structure of the superconducting conductive layer, has its inner wall metallurgically bonded to the outer wall of the bellows 101 via high-temperature brazing, ensuring mechanical strength and extremely low thermal contact resistance. The composite conductive framework 2 has an annular cross-section, with multiple concave insert grooves 201 formed along the axial or helical direction within the annular wall. The composite conductive framework 2 is preferably made of oxygen-free copper or aluminum alloy with high thermal conductivity, providing stable mechanical support for the superconducting wire 3 and an effective current shunting path in case of superconducting instability.

[0066] In one specific embodiment, the bellows 101 is made of a high-strength, low-thermal-conductivity metal such as stainless steel. The stainless steel bellows can withstand the internal pressure of liquid hydrogen while ensuring flexibility, thus ensuring the sealing and safety of liquid hydrogen transportation.

[0067] like Figure 3 and Figure 4 As shown, the number of mounting slots 201 can be flexibly designed according to the current carrying capacity requirements, preferably 16-64. The cross-sectional shape of the mounting slots 201 is designed as an arc shape that matches the cross-section of the superconducting wire 3 to ensure the maximum contact area. The mounting slots 201 can be set as straight slots parallel to the axis of the superconducting cable, or as a spiral structure along the spiral direction inside the annular wall of the composite conductive skeleton 2. The latter can realize the natural transposition of the superconducting wire 3 and effectively reduce AC loss.

[0068] The superconducting wire 3 is preferably made of MgB2 wire with a diameter ranging from 0.8 to 2.0 mm. For example... Figure 5 As shown, the superconducting wire 3 is fixed in the mounting groove 201 by interference fit, brazing or conductive adhesive bonding, ensuring that the superconducting wire 3 and the composite conductive skeleton 2 form a mechanical and thermal connection with low thermal resistance and high reliability.

[0069] In applications requiring higher current carrying capacity, multiple superconducting wires 3 can be arranged within each mounting slot 201 and fixed by a limiting structure 11. The thickness of the limiting structure 11 is adjusted according to the number of layers of the superconducting wires 3 to ensure tight arrangement and reliable fixation of the wires. The limiting structure is a mechanical fixing element installed within the mounting slot 201, featuring an Ω-shaped or crescent-shaped cross-section, forming a covering contact with the outer surface of the superconducting wires 3.

[0070] In one specific embodiment, at least one sidewall of at least a portion of the fitting slot 201 is an adaptive deformable wall; the adaptive deformable wall is composed of a functional material layer that is temperature-sensitive and capable of thermal deformation, such that the width of the fitting slot can adaptively change according to temperature variations at its location. For example, the adaptive deformable wall may employ a shape memory polymer (SMP), a thermo-shrinking / expanding polymer, a liquid crystal elastomer (LCE), or a shape memory alloy (SMA).

[0071] In one specific embodiment, the adaptive deformable wall is a bimetallic composite layer or a composite layered structure composed of two or more materials with different coefficients of thermal expansion; in particular, the adaptive deformable wall is a composite layered structure composed of two or more materials with significantly different coefficients of thermal expansion. For example, the two materials with significantly different coefficients of thermal expansion are brass and carbon steel, with brass serving as the active layer with a high coefficient of thermal expansion (CTE) of 19 × 10⁻⁶. -6 / ℃; Carbon steel as the passive layer of low thermal expansion coefficient CTE has a CTE of 11×10. -6 / ℃.

[0072] In one embodiment, the adaptive deformable wall is configured such that when the local temperature rises, the wall bends and deforms toward the inside of the fitting groove.

[0073] In one specific embodiment, of the two materials constituting the adaptive deformable wall, the linear thermal expansion coefficient of the material facing the inside of the groove is greater than that of the material facing away from the inside of the groove.

[0074] In one specific embodiment, the deformation response temperature of the adaptive deformable wall is matched with the critical temperature range of the superconducting wire 3.

[0075] The central liquid hydrogen channel 1 and the outer liquid hydrogen channel 8 can be designed to be interconnected to form a parallel cooling flow path, or they can be designed to be independent so that the flow rate and pressure can be controlled separately. This dual-channel design not only provides redundant cooling protection, but also enhances the system's thermal management flexibility.

[0076] Example 1 like Figure 2 and Figure 6 As shown, this example provides a superconducting cable for co-transporting hydrogen based on a composite skeleton, with the following specific parameters: The central liquid hydrogen channel 1 has a diameter of 30 mm and is composed of a bellows 101 with a wall thickness of 0.5 mm. The composite conductive framework 2 has an annular cross-section; its outer diameter is 50 mm, and it is made of oxygen-free copper. The inner wall is brazed to form an integral structure with the bellows 101. The composite conductive framework 2 has 32 straight-line insert slots 201, which are evenly distributed on a circumference with a radius of 25 mm.

[0077] Each mounting slot 201 contains a 1.2mm diameter MgB2 superconducting wire 3, which is fixed by interference fit. The surface of the superconducting wire 3 is coated with a thin layer of polyimide insulation.

[0078] The insulation system includes: an inner semiconductor layer 4 (semi-conductive polyolefin material, 0.5 mm thick), a main insulation layer 5 (PPLP material, 3 mm thick), and an outer semiconductor layer 6 (semi-conductive polyolefin material, 0.5 mm thick). The shielding layer 7 uses a copper tape wrapping structure. The annular cross-sectional area of ​​the outer liquid hydrogen channel 8 is 1.2 times that of the central liquid hydrogen channel 1. Between the shielding layer 7 and the outer liquid hydrogen channel 8, multiple radial insulating support pads made of low thermal conductivity composite material are spaced along the cable axis to fix the internal core structure and reduce radial heat leakage. The insulation layer 9 (30 mm thick, to ensure that the static evaporation rate per unit length of cable is lower than the design value) uses a vacuum multilayer insulation structure, consisting of alternating layers of aluminum foil reflectors and fiberglass paper spacers, and is sealed in a high vacuum environment (vacuum degree lower than...). In the Pa), the outer protective sleeve 10 (thickness of 3.0 mm, meeting the mechanical strength requirements for direct burial) is made of high-strength polyethylene material.

[0079] This example provides a superconducting cable for co-transporting hydrogen based on a composite skeleton. Its design operating temperature is 20-25K, its design transmission capacity is 110kV / 8kA, and its liquid hydrogen transport capacity is 400kg / h. Test results show that the structure exhibits uniform cooling, good superconducting stability, and mechanical strength that meets engineering application requirements.

[0080] Example 2 like Figure 4 and Figure 7 As shown, this example provides another electro-hydrogen co-transport superconducting cable based on a composite framework, the main difference from Example 1 being: The composite conductive framework 2 has 64 spiral-shaped insert grooves 201 with a spiral pitch of 800 mm. The insert grooves 201 are arranged in two layers, with 32 grooves in the inner layer located on a circle with a radius of 24.4 mm and 32 grooves in the outer layer located on a circle with a radius of 25.6 mm. The grooves in the inner and outer layers are staggered.

[0081] Each mounting slot 201 contains two 0.8mm diameter MgB2 superconducting wires 3, which are fixed by silver-based brazing. The central liquid hydrogen channel 1 and the outer liquid hydrogen channel 8 are independent of each other and their flow rates can be adjusted separately.

[0082] The cable is designed to operate at temperatures between 25-30K, with a designed transmission capacity of 132kV / 12kA and a liquid hydrogen delivery capacity of 600kg / h. The spiral groove structure effectively reduces AC losses, and the dual independent cooling channels provide better temperature control accuracy.

[0083] The composite-framed superconducting cable for co-transmission of electricity and hydrogen provided by this invention exhibits significant advantages in energy transmission efficiency, structural compactness, and system reliability. The composite conductive frame of this invention solves the problems of mechanical fixation and thermal contact of superconducting materials in existing co-transmission cables. This innovative structure ensures continuous and efficient thermal management, enabling the superconducting material to operate stably at liquid hydrogen temperatures, while simultaneously achieving safe and reliable transmission of electricity and hydrogen energy.

[0084] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A superconducting cable for co-transporting hydrogen based on a composite skeleton, characterized in that, Including the following, arranged sequentially from the inside out: A central liquid hydrogen channel (1) is formed within which a first liquid hydrogen transport channel is constructed; A composite conductive skeleton (2) has an annular cross-section; the composite conductive skeleton (2) is provided with multiple embedding grooves (201); and one or more superconducting wires (3) are embedded in the embedding grooves (201). Insulation system; An outer liquid hydrogen channel (8) is formed within the outer liquid hydrogen channel (8); Outer protective structure.

2. The electro-hydrogen co-transport superconducting cable based on a composite skeleton according to claim 1, characterized in that, The composite conductive skeleton (2) has multiple recessed insert grooves (201) in the annular wall along the axial or spiral direction.

3. The electro-hydrogen co-transport superconducting cable based on a composite skeleton according to claim 2, characterized in that, At least one sidewall of the insert groove (201) is an adaptive deformable wall; the adaptive deformable wall is composed of a functional material layer that can generate thermal deformation, so that the local width of the insert groove (201) can be adaptively changed according to the temperature change at its location, thereby applying a dynamically changing contact pressure to the superconducting wire (3) in the insert groove (201).

4. The electro-hydrogen co-transport superconducting cable based on a composite skeleton according to claim 1, characterized in that, The superconducting wire (3) is fixed in the mounting groove (201) by interference fit, brazing or conductive adhesive bonding.

5. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 1, characterized in that, The multiple embedding slots (201) are arranged in two or more layers along the radial direction of the electro-hydrogen co-transmission superconducting cable, with adjacent embedding slots (201) staggered.

6. The electro-hydrogen co-transport superconducting cable based on a composite skeleton according to claim 1, characterized in that, The central liquid hydrogen channel (1) is composed of a bellows (101); the inner wall of the composite conductive skeleton (2) is metallurgically bonded to the outer wall of the bellows (101) by high-temperature brazing.

7. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 1, characterized in that, The insulation system includes an inner semiconductor layer (4), a main insulation layer (5), and an outer semiconductor layer (6) arranged sequentially from the inside to the outside.

8. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 7, characterized in that, A shielding layer (7) with a copper strip wrapping structure is provided between the outer semiconductor layer (6) and the outer liquid hydrogen channel (8).

9. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 1, characterized in that, The outer protective structure includes an insulation layer (9) and an outer protective sleeve (10) arranged from the inside out.

10. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 3, characterized in that, The adaptive deformable wall is a bimetallic composite layer or a composite layered structure composed of two or more materials with different coefficients of thermal expansion.

11. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 3, characterized in that, The adaptive deformable wall is configured such that when the local temperature rises, the wall of the adaptive deformable wall bends or expands inward toward the inset of the fitting groove (201).

12. A superconducting electro-hydrogen co-transport cable based on a composite skeleton according to claim 3, characterized in that, The deformation response temperature of the adaptive deformable wall matches the critical temperature range of the superconducting wire (3).

13. A control method for a composite-framed electro-hydrogen co-transport superconducting cable, characterized in that, A composite-framed electro-hydrogen co-transport superconducting cable according to any one of claims 1 to 12, comprising: The control center liquid hydrogen channel (1) and the outer liquid hydrogen channel (8) are interconnected to form a parallel cooling flow path, which operates under the same pressure; Alternatively, the central liquid hydrogen channel (1) and the outer liquid hydrogen channel (8) can operate independently at different flow rates and pressures.

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