Superconducting cable low-temperature system for space

Abstract

The invention discloses a superconducting cable low-temperature system for space. The superconducting cable low-temperature system comprises a plurality of low-temperature modules and a superconducting cable, the superconducting cable comprises a first cable joint, a cable and a second cable joint. The low-temperature module comprises a refrigerator and a cryogenic loop heat pipe; the refrigerating machine is used for cooling the low-temperature working medium in the closed communicating pipeline; the copious cooling loop heat pipe comprises a secondary liquid storage device, a secondary evaporator, a main evaporator, a main liquid storage device, a main steam loop, a secondary liquid pipeline, a secondary condenser, a main condenser, a secondary steam pipeline and a main liquid pipeline which are communicated in sequence. The cryogenic loop heat pipe is a closed communicating pipeline, and the pipeline is filled with a low-temperature working medium; the first cable joint and the second cable joint are respectively connected with the secondary evaporator and the main evaporator for cooling, and the cable is wound on the outer wall of the main liquid pipeline to realize cooling of the superconducting cable; for long-distance superconducting cable application, a plurality of low-temperature modules are sequentially coupled and connected with a cable through main liquid pipelines in respective modules, so that long-distance superconducting cable cooling is realized.

Description

Technical Field

[0001] The invention relates to a low-temperature system for a superconducting cable for space, belonging to the technical field of aerospace thermal control. Background Art

[0002] As spacecraft grow in size, performance improves, and functions expand, their operating power will rise from hundreds of kilowatts to megawatts or even gigawatts, while the supply voltage will reach megavolts. The energy loss, volume, and weight of power transmission systems using traditional copper conductor cables will become unacceptable. Superconducting cables have the advantages of zero resistance, high current density, and large-capacity transmission below the critical temperature, enabling lossless power transmission. Under the same conditions, the power transmission system composed of them weighs only about 4% of that of traditional copper cables, making them very suitable for large-scale current transmission in future space applications and having great potential for space applications.

[0003] Currently, commercial superconducting cables typically operate in the liquid nitrogen temperature range and suffer from significant heat leakage during operation. First, there is a high temperature gradient between the ends of the superconducting cable and the room-temperature conventional cable, resulting in significant heat leakage from conduction. Second, there is heat leakage from radiation between the middle section of the cable and the room-temperature environment. Therefore, stable low-temperature conditions are essential for superconducting cables to function properly. Existing cryogenic systems for terrestrial superconducting cables are well-established, primarily using direct cooling via liquid nitrogen evaporation and indirect cooling via refrigerators.

[0004] Liquid nitrogen evaporative cooling involves installing superconducting cables directly in pipes containing supercooled liquid nitrogen, utilizing the liquid nitrogen's phase change and heat absorption process to provide a low-temperature environment while simultaneously discharging the gaseous working fluid. Large liquid nitrogen tanks are required for replenishment to maintain the low-temperature environment. Indirect cooling systems based on refrigerators use the refrigerator as a cold source, with cryogenic pumps driving the liquid working fluid to deliver the refrigerator's cooling capacity to the superconducting cables to provide a low-temperature environment. The gaseous working fluid then returns to the refrigerator for re-cooling and liquefaction before returning to the system for circulation. Furthermore, hybrid refrigeration systems have been derived from the combination of different refrigeration solutions, including those combining refrigerators with liquid nitrogen evaporation and refrigerators with refrigerators.

[0005] For terrestrial applications, the existing superconducting cable cryogenic systems mainly include the following:

[0006] (1) Cooling device using a mechanical refrigerator and a mechanical pump to transport sub-cooled liquid nitrogen through a cryogenic pipeline. Patent ZL200520022781.0, "Sub-cooled Liquid Nitrogen Circulating Cooling Device for Cooling High-Temperature Superconducting Cables," proposes a method for transporting sub-cooled liquid nitrogen to the cryogenic container of a superconducting cable using a vacuum liquid nitrogen decompression refrigerator or a mechanical closed refrigerator as a cooling source and a cryogenic liquid pump as a power source for high-temperature superconducting cables used on the ground. This device is large in size and weight, and its key components, the gas-liquid separator and the liquid nitrogen pump, are not suitable for use in the microgravity environment of space. Therefore, this cooling device is not suitable for superconducting cables used in space.

[0007] (2) Consumable cooling devices using cryogenic fluid as the working fluid. Patent ZL201210548114.0 "Method for Cooling Equipment for Superconducting Cables" proposes a method for cooling superconducting cables using liquid nitrogen as the working fluid for ground applications. This method requires continuous replenishment of the liquid nitrogen reserves in the liquid nitrogen tank during operation. This method cannot be replenished in orbit, making it difficult to use for a long time and failing to meet the maintenance-free requirements of space applications.

[0008] The cryogenic system of superconducting cables for space use must meet the following requirements:

[0009] (1) The spacecraft platform has strict restrictions on the weight, volume, energy consumption, low vibration and reliability of the cryogenic system.

[0010] (2) It must be able to adapt to long-life on-orbit operation scenarios without maintenance or without maintenance;

[0011] (3) It must adapt to typical space mission environments such as launch process mechanics, high vacuum on orbit, microgravity, and alternating thermal environments.

[0012] Existing solutions utilize consumable refrigeration solutions and rely on gravity for gas-liquid phase separation, which are not suitable for satellites in orbit. Currently, according to publicly available reports, no superconducting cable cryogenic systems for space applications have been established, either domestically or internationally, and no research results in related fields have been found. Therefore, those skilled in the art are committed to developing a superconducting cable cryogenic system for space that leverages the advantages of large-scale cooling capacity from refrigerators and large-scale cooling capacity from long-distance two-phase heat transfer systems. This system can meet the cryogenic system requirements of superconducting cables in space environments, fill the technological gap in the field of space superconducting cables, and support the large-scale application of superconducting cables in space environments in the future. Summary of the Invention

[0013] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and provide a space superconducting cable low-temperature system that adapts to the microgravity environment, which can provide a stable and uniform low-temperature environment for the superconducting cable, and at the same time meet special needs such as long-distance flexible connection of the superconducting cable.

[0014] The technical solution of the present invention is:

[0015] The present invention discloses a space superconducting cable cryogenic system, comprising: a plurality of cryogenic modules and a superconducting cable; the superconducting cable comprises a first cable joint, a superconducting cable line and a second cable joint;

[0016] The low temperature module includes a refrigerator and a cryogenic loop heat pipe;

[0017] The cryogenic loop heat pipe is a closed interconnected pipe filled with cryogenic working fluid;

[0018] A cryogenic loop heat pipe comprises a secondary liquid reservoir, a secondary evaporator, a main evaporator, a main liquid reservoir, a main steam loop, a secondary liquid line, a secondary condenser, a main condenser, a secondary steam line and a main liquid line; wherein,

[0019] The first cable connector and the second cable connector are connected to the secondary evaporator and the main evaporator respectively; the refrigerator is connected to the main condenser and the secondary condenser; the secondary evaporator and the main evaporator are connected through a main steam circuit; the secondary liquid reservoir and the main liquid reservoir are connected through a secondary liquid pipeline; the secondary evaporator and the secondary condenser are connected through a secondary steam pipeline; the main condenser and the main liquid reservoir are connected through a main liquid pipeline; the main evaporator and the main liquid reservoir are in communication; the secondary evaporator and the secondary liquid reservoir are in communication;

[0020] The refrigerator is used to cool the low-temperature working medium in the closed connecting pipeline to achieve cooling of the superconducting cable;

[0021] The main liquid pipelines of several low-temperature modules are coupled and connected with the superconducting cables in sequence to realize the cooling of long-distance superconducting cables.

[0022] Furthermore, in the above system, the cooling energy generated by the refrigerator is transferred to the main condenser and the secondary condenser, so that the gaseous working fluid in the main condenser and the secondary condenser is liquefied and accumulated inside; the liquid working fluid is gathered inside the secondary liquid reservoir and the secondary evaporator; when the liquid working fluid reaches a certain amount, the secondary evaporator starts working, driving the gaseous working fluid in the secondary steam pipeline to reach the main condenser; the liquid working fluid gathered inside the main condenser is transmitted to the main liquid reservoir and the main evaporator along the main liquid pipeline; when the liquid working fluid inside the main evaporator reaches a certain amount, the main evaporator starts working, driving the gaseous working fluid in the main steam loop to reach the main condenser, and is liquefied when cooled; the working fluid inside the deep-cold loop heat pipe circulates to cool the superconducting cable.

[0023] Furthermore, in the above system, the cryogenic loop heat pipe also includes a gas storage chamber, which is connected to the main evaporator through the main steam loop and communicates with the gas working medium in the cryogenic loop heat pipe to reduce pressure and prevent overpressure.

[0024] Furthermore, in the above system, the first cable joint and the second cable joint are cooled by the primary evaporator and the secondary evaporator, and the superconducting cable is cooled by the primary liquid pipeline.

[0025] Furthermore, in the above system, the main evaporator and the secondary evaporator are both provided with grooves and micro-nano pore capillary structures made of porous materials; when the supercooled working fluid inside the secondary evaporator or the main evaporator reaches a certain amount, the micro-nano pore capillary structure is infiltrated by the supercooled working fluid and reaches the starting conditions, the starting operation causes the liquid supercooled working fluid inside to undergo a phase change.

[0026] Furthermore, in the above system, the refrigerator includes a compressor and a refrigeration end; the refrigeration end and the main condenser, and the refrigeration end and the secondary condenser are connected by welding, screw connection, powder metallurgy, cold chain connection or integrated processing and molding, and the compressor cools the refrigeration end.

[0027] Furthermore, in the above system,

[0028] The superconducting cable includes a cable, an insulation layer and a low-temperature multi-layer thermal insulation component; wherein the cable is wound on the main liquid pipeline using a coaxial co-winding process; the cable includes a first cable and a second cable, and the insulation layer uses a coaxial sleeve method to isolate the first cable and the second cable; the outside of the cable is wrapped with a low-temperature multi-layer thermal insulation component.

[0029] Furthermore, in the above system, the primary evaporator and the secondary evaporator are respectively connected to the first cable connector and the second cable connector by welding, screw connection or powder metallurgy connection, or are formed by one-piece processing.

[0030] Furthermore, in the above system,

[0031] Depending on the length of the superconducting cable, a single or multiple refrigerators are connected in parallel to meet different cooling requirements.

[0032] Furthermore, in the above system, the low-temperature working fluid in the cryogenic loop heat pipe is helium, hydrogen, neon, nitrogen or oxygen.

[0033] The beneficial effects of the present invention and the prior art are:

[0034] (1) The present invention adopts an integrated coupling scheme of superconducting cable with space cooling acquisition, space cooling transmission and space thermal insulation devices. The cooling acquisition device is used as the system cooling source, and the space cooling transmission device transmits cooling to cable joints, cables and other locations, providing a low-temperature working environment for the superconducting cable and ensuring uniform cable temperature. The space thermal insulation device reduces the system's external radiation heat leakage and conduction heat leakage. The cooling acquisition and cooling transmission schemes adopted are both closed systems that can adapt to the microgravity and launch mechanical environment on orbit. They have the advantages of being maintenance-free, highly reliable, long-life, and controllable in weight and volume. They solve the problems of the low-temperature system of ground superconducting cables in space environments, such as difficult maintenance, insufficient reliability, short life, and difficulty in controlling weight and volume.

[0035] (2) The present invention uses a superconducting cable coupled with a refrigerator and a cryogenic loop heat pipe to provide a low-temperature operating environment for the superconducting cable, which has the advantages of high transmission efficiency, high reliability, and good temperature uniformity. The working fluid can be selected based on the superconducting cable material, and can achieve the cooling capacity transmission requirement of 4.2 to 120K, which is suitable for the working requirements of both high-temperature and low-temperature superconductors.

[0036] (3) The present invention uses a low-temperature pulse tube refrigerator and an air-bearing-based inverse Brayton refrigerator as space cooling devices, and adopts single or multiple parallel refrigerators to meet different cooling requirements according to the length requirements of different superconducting cables. The above refrigerators are all mechanical refrigerators, consisting of a compressor and a cooling end. The waste heat generated by the compressor and the cooling end is radiated to the space heat sink through the spacecraft radiator. They can adapt to the microgravity environment of space and have the advantages of low vibration and high reliability. They can continuously provide a low-temperature working environment in the temperature range of 4.2K to 120K for space superconducting cables.

[0037] (4) The present invention adopts a capillary-driven cryogenic loop heat pipe that can adapt to microgravity and reverse gravity. It can adapt to the microgravity environment of space through a gas-liquid distribution control method based on surface tension. The cryogenic loop heat pipe is a closed module that can achieve efficient transmission of cold. Its internal heat transfer medium can be selected from oxygen, nitrogen, neon, hydrogen, helium and other working fluids. It can adapt to different temperature zones such as 80K, 35K, 20K, 4.2K, and can achieve efficient heat transfer with a small temperature difference of 10m by using micro-nano aperture capillary force. Compared with a mechanical pump-driven two-phase fluid circuit, a cryogenic loop heat pipe driven by capillary force can save energy consumption and has the advantages of high reliability, low vibration, and no energy consumption requirements. It can realize the collection and transportation of heat in a microgravity environment, while meeting the requirements for free swing of superconducting cables, and can realize the collection and transmission function of waste heat of space superconducting cables.

[0038] (5) The present invention uses low-temperature multi-layer insulation components and low-temperature solid insulation components, etc., in view of the characteristics of the space thermal environment, to reduce the system's heat leakage from conduction and radiation to the outside world. The outside of the entire system is wrapped with specially designed low-temperature multi-layer insulation components suitable for low-temperature areas, such as multi-layer embossed reflective screens, multi-layer hollow glass microbead spacers, etc., which can adapt to low-temperature working environments below 80K. Low-temperature solid insulation components are used between the low-temperature system and the connected normal temperature platform to weaken the impact of heat conduction on the low-temperature system. In addition, for scenarios where superconducting cables need to be installed in the air, low-temperature flexible connecting components such as Kevlar ropes can be used to weaken heat conduction, which solves the problem of heat leakage suppression of space superconducting cables and meets the requirement of free cable swinging.

[0039] (6) The cryogenic loop heat pipe used in the present invention has the characteristics of long heat transfer distance, small temperature difference, no mechanical moving parts, and adaptability to microgravity environment. Its pipeline is generally made of millimeter-grade stainless steel, which can be arranged according to actual needs. The application form is flexible and changeable, and it is particularly suitable for solving the "point-to-point" heat transfer problem of spacecraft. In the prior art, the cryogenic loop heat pipe with a dual-circuit dual-evaporator structure is mature and has completed on-orbit verification. In this structure, the primary and secondary evaporators can be arranged at a certain distance apart, and the surrounding heat can be transferred to the condenser in the form of latent heat of the working fluid, and discharged in the form of radiation. The liquid pipeline is always in a low-temperature state during operation, and can provide a slender strip-shaped low-temperature zone.

[0040] (7) The present invention uses a cryogenic loop heat pipe as a cold transmission device of an integrated coupling scheme, which can fully utilize the characteristics of the dual evaporator separation arrangement and low-temperature gas-liquid pipeline of the cryogenic loop heat pipe to realize the division of labor design of different heat transport. The cable joints at both ends of the superconducting cable have a large amount of heat leakage from low temperature to room temperature, and the evaporator transmission capacity of the cryogenic loop heat pipe is strong. Therefore, the cable joints at both ends are respectively coupled with the main evaporator and the secondary evaporator of the cryogenic loop heat pipe. The heat leakage of the cable joint coupled with the secondary evaporator can be well used for supercritical startup and auxiliary operation. After the system is started, the heat leakage of the cable joint is taken away in the form of latent heat of the working fluid. The low-temperature liquid pipeline is coupled with the cable, and the strip-shaped low-temperature zone formed by the liquid pipeline can realize the cooling of the cable. The characteristics of the cryogenic loop heat pipe are matched with the heating characteristics of the superconducting cable to maximize the energy utilization of the system, ensure the temperature uniformity of the superconducting cable, and meet the strict restrictions on the weight, volume, and energy consumption of the spacecraft platform for the low-temperature system.

[0041] (8) The present invention can match the heat leakage of the cable by designing the subcooling section and subcooling degree of the condenser in the cryogenic loop heat pipe, thereby ensuring the overall temperature uniformity of the superconducting cable. The heat leakage of the low-temperature section cable is mainly parasitic heat leakage from the environment to the low temperature, and the heat leakage is relatively small. The low-temperature liquid pipeline is coupled with the cable cable, and the cable is wrapped around the outer wall of the main liquid pipeline. At the same time, the low-temperature multi-layer insulation component is wrapped on the outermost side. The supercooled liquid flowing out of the condenser to the main liquid pipeline is used to cool the cable, ensuring the temperature uniformity of the superconducting cable. At the same time, the coupling structure of the cable and the liquid pipeline has a certain degree of flexibility, which is convenient for on-board layout and meets the swing requirements of the cable.

[0042] (9) The present invention's space-use superconducting cable cryogenic system uses a refrigerator as a cryogenic cold source, and a deep-cold loop heat pipe to achieve low-temperature heat collection and transmission. At the same time, low-temperature insulation technologies such as low-temperature multi-layer insulation components and low-temperature solid insulation components are used to reduce parasitic heat leakage. Structurally, the refrigerator and the condenser, as well as the cable connector and the evaporator, are coupled according to actual physical constraints. The coupling connection between the condenser and the refrigeration end can be achieved by welding, screw connection, powder metallurgy, cold chain connection, or integrated processing and molding. The cable connector is generally in the shape of a truncated cone, and a cylindrical evaporator of appropriate size can be embedded inside it and connected by welding, screw connection, powder metallurgy, cold chain connection, or integrated processing and molding. The above-mentioned coupling connection structure can achieve uniform and stable heat conduction. A coaxial winding process can be used between the cable and the liquid pipeline to wrap the cable around the liquid pipeline, and at the same time, a low-temperature multi-layer insulation component is wrapped on the outermost side to reduce the impact of space radiation.

[0043] (10) The coupling module of the single space cooling acquisition, space cooling transmission and space insulation device of the present invention can provide a low-temperature working environment for a ten-meter-class cable. In view of the application requirements of long-distance space superconducting cables, the present invention has a modular expansion function. It can be flexibly configured according to actual application requirements, and adaptively designed according to the direction, layout and cable support position of the superconducting cable in the spacecraft, and a short-distance space superconducting cable low-temperature system that meets different cooling requirements is developed. The packaging and interface design are also carried out to achieve modular combination. This design allows the installation of multiple sets of low-temperature system modules to provide a stable and uniform low-temperature working environment for a hundred-kilometer-class superconducting cable. At the same time, it also achieves convenient installation and low-cost maintenance, which can solve the thermal management problem of future long-distance space superconducting cables.

[0044] (11) When using this system for modular expansion, in view of the fact that the heat generated by the joints at both ends of the superconducting cable is relatively high, the cable joints can be coupled with the secondary evaporator in the cryogenic module system that is closer to the cooling end to ensure efficient use of cooling capacity. In view of the fact that the heat consumption of the middle section of the cable is relatively low, multiple sets of modular cryogenic systems in series can be arranged according to the length of the superconducting cable and the cable support position. The local parasitic heat leakage at the cable support position is relatively large. The coupling position of the cryogenic module is matched with the cable support position. The parasitic heat leakage at the support position can be used for supercritical startup and auxiliary operation, and dissipated through the evaporator of the cryogenic module after the system is started. This modular design allows the installation of multiple sets of cryogenic system modules to provide a stable and uniform low-temperature working environment for the hundred-kilometer-level superconducting cable, while also achieving convenient installation and low-cost maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural diagram of an embodiment of the present invention;

[0046] Figure 2 This is a schematic structural diagram of a preferred embodiment of the coupling of a cable and a liquid pipeline of the present invention;

[0047] Figure 3 It is a structural schematic diagram of a preferred embodiment of the modular design of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0049] like Figure 1 As shown, the present invention discloses a superconducting cable cryogenic system for space use, comprising: a plurality of cryogenic modules and a superconducting cable; the superconducting cable comprises a first cable joint 3, a superconducting cable line and a second cable joint 6;

[0050] Several cryogenic modules are coupled with superconducting cables in sequence through the main liquid pipelines in their respective modules to achieve cooling of long-distance superconducting cables; Figure 3 As shown;

[0051] A low temperature module, comprising a refrigerator 1 and a cryogenic loop heat pipe;

[0052] The cryogenic loop heat pipe is a closed interconnected pipeline filled with a cryogenic working medium, which is in a gas-liquid two-phase state within the working temperature range of the superconducting cable.

[0053] The cryogenic loop heat pipe includes a secondary liquid reservoir 4, a secondary evaporator 5, a main evaporator 7, a main liquid reservoir 8, a main steam loop 9, a secondary liquid pipeline 11, a secondary condenser 14, a main condenser 15, a secondary steam pipeline 16 and a main liquid pipeline 17; wherein,

[0054] The first cable connector 3 and the second cable connector 6 are connected to the secondary evaporator 5 and the main evaporator 7 respectively; the refrigerator 1 is connected to the main condenser 15 and the secondary condenser 14; the secondary evaporator 5 and the main evaporator 7 are connected through the main steam circuit 9; the secondary liquid reservoir 4 and the main liquid reservoir 8 are connected through the secondary liquid pipeline 11; the secondary evaporator 5 and the secondary condenser 14 are connected through the secondary steam pipeline 16; the main condenser 15 and the main liquid reservoir 8 are connected through the main liquid pipeline 17; the main evaporator 7 and the main liquid reservoir 8 are in communication; the secondary evaporator 5 and the secondary liquid reservoir 4 are in communication; so as to achieve efficient transmission of cooling capacity;

[0055] The refrigerator 1 is used to cool the low-temperature working medium in the closed communicating pipeline, thereby cooling the superconducting cable.

[0056] Preferably, the cooling energy generated by the refrigerator 1 is transferred to the main condenser 15 and the secondary condenser 14, so that the gaseous working fluid in the main condenser 15 and the secondary condenser 14 is liquefied and accumulated inside; the liquid working fluid is gathered inside the secondary liquid reservoir 4 and the secondary evaporator 5; when the liquid working fluid reaches a certain amount, the secondary evaporator 5 starts working, driving the gaseous working fluid in the secondary steam pipeline 16 to reach the main condenser 15; the liquid working fluid gathered inside the main condenser 15 is transmitted along the main liquid pipeline 17 to the main liquid reservoir 8 and the main evaporator 7; when the liquid working fluid inside the main evaporator 7 reaches a certain amount, the main evaporator 7 starts working, driving the gaseous working fluid in the main steam loop 9 to reach the main condenser 15, and liquefied when cooled; the working fluid inside the cryogenic loop heat pipe realizes circulation work to cool the superconducting cable.

[0057] Preferably, the cryogenic loop heat pipe further includes a gas storage chamber 10, which is connected to the gas working medium in the cryogenic loop heat pipe through the main steam loop 9 to reduce the pressure and prevent overpressure.

[0058] Preferably, the main evaporator 7 and the secondary evaporator 5 are both provided with grooves and micro-nano pore capillary structures made of porous materials; when the supercooled working fluid inside the secondary evaporator 5 or the main evaporator 7 reaches a certain amount, the micro-nano pore capillary structure is infiltrated by the supercooled working fluid and reaches the starting conditions, the starting operation causes the liquid supercooled working fluid inside to undergo a phase change.

[0059] Preferably, the refrigerator 1 includes a compressor 13 and a refrigeration end 12, which is filled with a cooling medium; the refrigeration end 12 and the main condenser 15, and the refrigeration end 12 and the secondary condenser 14 are connected by welding, screw connection, powder metallurgy, cold chain connection or integrated processing and molding, and the compressor 13 cools the refrigeration end 12.

[0060] Preferably, the superconducting cable includes a cable 2, an insulating layer 18 and a low-temperature multi-layer thermal insulation component 19; wherein the cable 2 is wound on the main liquid pipeline 17 using a coaxial co-winding process; the cable 2 includes a first cable and a second cable, and the insulating layer 18 uses a coaxial sleeve method to isolate the first cable and the second cable to prevent the current from flowing in an abnormal path, while suppressing dielectric loss and reducing thermal effects; the cable 2 is wrapped with a low-temperature multi-layer thermal insulation component 19 on the outside to form a cable-pipeline coupling body 20, so that heat exchange between the superconducting cable and the cryogenic loop heat pipe can be achieved, while reducing the influence of space radiation. Figure 2 shown.

[0061] Preferably, the main evaporator 7 and the secondary evaporator 5 are respectively connected to the first cable connector 3 and the second cable connector 6 by welding, screw connection or powder metallurgy connection, or are formed by integral processing.

[0062] Preferably, according to different superconducting cable lengths, a single or multiple refrigerators are connected in parallel to meet different cooling requirements.

[0063] Preferably, the low-temperature working fluid in the cryogenic loop heat pipe is helium, hydrogen, neon, nitrogen or oxygen.

[0064] The space cable cryogenic system can be modularly expanded. Figure 3 The figure shows a schematic structural diagram of a preferred embodiment. At both ends of the superconducting cable, the first cable connector 3 and the second cable connector 6 are respectively coupled to the secondary evaporator 5 in the corresponding low-temperature module system 21; in the middle section of the cable, a plurality of groups of parallel low-temperature module systems 21 are arranged in sequence according to the length of the superconducting cable, and the main liquid pipeline 17 in each module system is coupled with the cable 2 to form a cable-pipeline coupling body 20 to provide a low-temperature environment; the heat consumption of the middle section of the cable is low, and the temperature uniformity on the cable 2 can be ensured by wrapping the low-temperature multi-layer insulation component 19 in the intersection area of ​​each low-temperature module system 21; each low-temperature module system operates independently of each other, and the potential fault module can be quickly located and replaced by monitoring the operating status of each module, thereby reducing the cost and difficulty of subsequent maintenance of the system.

[0065] The working principle of the present invention is as follows:

[0066] The space superconducting cable cryogenic system proposed in the present invention adopts a refrigerator as a low-temperature cold source and a deep-cold loop heat pipe to realize low-temperature heat collection and transmission. At the same time, low-temperature insulation technologies such as low-temperature multi-layer insulation components and low-temperature solid insulation parts are adopted to reduce parasitic heat leakage.

[0067] A cryogenic loop heat pipe is a cold transfer device that forms an integrated coupled system. Its main components include primary and secondary evaporators, primary and secondary condensers, primary and secondary liquid reservoirs, primary and secondary steam pipelines, primary and secondary liquid pipelines, and a gas storage chamber. The working fluid within the heat pipe should be in a gas-liquid two-phase state within the operating temperature range of the superconducting cable. The primary and secondary evaporators contain internal channels and a capillary structure composed of porous materials. The capillary force generated by this porous structure drives the flow of the internal heat transfer medium. The basic operating principle is to utilize the phase change process of the working fluid to release the heat load in the evaporator as latent heat through the steam pipeline to the condenser. Simultaneously, the working fluid becomes subcooled and flows through the liquid pipeline to the liquid reservoir for temporary storage, supplying the working fluid to the evaporator for continuous and stable circulation. Furthermore, because the working fluid is in a supercritical state before operation, the internal pressure of the system is high, requiring a gas storage chamber to reduce the system pressure to ensure safety.

[0068] A mechanical refrigerator is a cooling device in an integrated coupled system, consisting of a compressor and a cooling end. Electrical power is input to drive the compressor, generating cooling at the cooling end. A shared condenser design is employed, coupling the cooling end with the condenser to minimize cooling losses. Depending on the length of the superconducting cable, single or multiple parallel refrigerators can be used to meet varying cooling requirements. Only energy, not material, is exchanged between the refrigerator and the cooling transmission module, which consists of primary and secondary condensers, primary and secondary evaporators, gas storage chambers, primary and secondary gas pipelines, and primary and secondary liquid pipelines.

[0069] The space insulation system uses insulating supports and multi-layer insulation materials to reduce heat leakage through conduction and radiation. Appropriate low-temperature multi-layer insulation components are wrapped around the entire system. Low-temperature solid insulation components are used between the cryogenic system and the connected normal-temperature platform to mitigate the effects of heat radiation and conduction on the cryogenic system. For scenarios where superconducting cables need to be installed in the air, low-temperature flexible connecting components such as Kevlar can be used to reduce heat conduction while allowing the cable to swing freely.

[0070] The superconducting cable consists of a cable, a first cable connector, and a second cable connector. The cable is coupled to the main liquid pipeline to achieve heat exchange between the cable and the liquid pipeline; the first and second cable connectors are coupled to the primary and secondary evaporators, respectively, to achieve heat exchange between the connectors and the evaporators.

[0071] During operation of the cryogenic system, the primary and secondary evaporators absorb heat from the first and second cable connectors, respectively, causing the liquid working fluid inside to undergo a phase change, generating a capillary driving force that drives the gaseous working fluid along the gas pipeline to the condenser. In the condenser, the gaseous working fluid undergoes a phase change when it encounters cold, releasing the heat it carries as latent heat. The liquid working fluid then continues to absorb cold energy in the subcooling section, reaching a subcooled state, and moves along the liquid pipeline. Heat conduction keeps the liquid pipeline in the low-temperature zone, providing a stable and uniform low-temperature environment for the superconducting cable. The working fluid then reaches the primary and secondary liquid reservoirs, providing a continuous supply of working fluid to the primary and secondary evaporators, completing the cycle.

[0072] For this embodiment, the entire working process of the superconducting cable cryogenic system is as follows:

[0073] The electric power input drives the compressor 13 of the refrigerator 1 to operate, generating cooling at the cooling end 12;

[0074] The cooling energy generated by the refrigeration end 12 is transferred to the main condenser 15 and the secondary condenser 14 in the form of solid heat conduction, so that the gaseous working medium in the main condenser 15 and the secondary condenser 14 is liquefied and accumulated inside.

[0075] The subcooled liquid is collected inside the secondary liquid reservoir 4 and the secondary evaporator 5;

[0076] When the supercooled liquid infiltrates the internal porous structure, the secondary evaporator 5 enters the startup state;

[0077] The liquid working medium inside the secondary evaporator 5 undergoes a phase change, generating capillary force, which drives the gaseous working medium in the secondary vapor line 16 to the main condenser 15;

[0078] The subcooled working medium gathered in the main condenser 15 is transported along the main liquid pipeline 17 to the main liquid reservoir 8 and the main evaporator 7;

[0079] When the porous structure inside the main evaporator 7 is soaked by the subcooled working medium and reaches the starting condition, it enters the starting state;

[0080] The liquid working medium inside the main evaporator 7 undergoes a phase change, generating capillary force, which drives the gaseous working medium in the main steam loop 9 to the main condenser 15, where it is liquefied when cooled;

[0081] The cryogenic loop heat pipe completes the startup process, and the internal working fluid achieves stable circulation;

[0082] Gradually increase the starting power of the primary evaporator 7 and the secondary evaporator 5 until it is equal to the heat load generated at the first cable joint 3 and the second cable joint 6 when the superconducting cable is operating normally;

[0083] When the superconducting cable is turned on, the starting power of the main evaporator 7 and the secondary evaporator 5 is turned off, so that the heat load generated by the first cable connector 3 and the second cable connector 6 maintains the stable operation of the main evaporator 7 and the secondary evaporator 5. At the same time, there is also stable supercooled liquid inside the main liquid pipeline 17 to provide a low-temperature environment for the cable 2 on its outer wall.

[0084] In this way, the low-temperature system can provide a low-temperature working environment for the terminals and bodies of space superconducting cables. In addition, according to the actual operation and installation requirements, necessary low-temperature multi-layer insulation components and low-temperature solid insulation components are used to reduce the impact of heat radiation and heat conduction on the system, thereby ensuring the effective operation of the superconducting cable.

[0085] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above examples. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications. All variations that can be directly derived or associated with the contents disclosed by ordinary technicians in this field should be considered to be within the scope of protection of the present invention.

[0086] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0087] The contents not described in detail in the specification of the present invention belong to the common knowledge of professionals in this field.

Claims

1. A space superconducting cable cryogenic system, characterized in that: include: several cryogenic modules and superconducting cables; The superconducting cable comprises a first cable joint (3), a superconducting cable and a second cable joint (6); The low-temperature module comprises a refrigerator (1) and a cryogenic loop heat pipe; The cryogenic loop heat pipe is a closed interconnected pipe filled with cryogenic working fluid; A cryogenic loop heat pipe comprises a secondary liquid reservoir (4), a secondary evaporator (5), a primary evaporator (7), a primary liquid reservoir (8), a primary steam loop (9), a secondary liquid pipeline (11), a secondary condenser (14), a primary condenser (15), a secondary steam pipeline (16) and a primary liquid pipeline (17); wherein, The first cable connector (3) and the second cable connector (6) are connected to the secondary evaporator (5) and the main evaporator (7) respectively; the refrigerator (1) is connected to the main condenser (15) and the secondary condenser (14); the secondary evaporator (5) and the main evaporator (7) are connected via a main steam circuit (9); the secondary liquid reservoir (4) and the main liquid reservoir (8) are connected via a secondary liquid pipeline (11); the secondary evaporator (5) and the secondary condenser (14) are connected via a secondary steam pipeline (16); the main condenser (15) and the main liquid reservoir (8) are connected via a main liquid pipeline (17); the main evaporator (7) and the main liquid reservoir (8) are in communication; the secondary evaporator (5) and the secondary liquid reservoir (4) are in communication; The refrigerator (1) is used to cool the low-temperature working medium in the closed communicating pipeline to achieve cooling of the superconducting cable; The main liquid pipelines (17) of several low-temperature modules are coupled and connected with the superconducting cables in sequence to achieve cooling of the long-distance superconducting cables.

2. A space superconducting cable cryogenic system according to claim 1, characterized in that: The cooling energy generated by the refrigerator (1) is transferred to the main condenser (15) and the secondary condenser (14), so that the gaseous working medium in the main condenser (15) and the secondary condenser (14) is liquefied and accumulated inside; the liquid working medium is gathered inside the secondary liquid reservoir (4) and the secondary evaporator (5); when the liquid working medium reaches a certain amount, the secondary evaporator (5) starts working and drives the gaseous working medium in the secondary steam pipeline (16) to reach the main condenser (15); the liquid working medium gathered inside the main condenser (15) is transferred to the main liquid reservoir (8) and the main evaporator (7) along the main liquid pipeline (17); when the liquid working medium inside the main evaporator (7) reaches a certain amount, the main evaporator (7) starts working and drives the gaseous working medium in the main steam circuit (9) to reach the main condenser (15), where it is liquefied when cooled; the working medium inside the cryogenic loop heat pipe realizes circulation work, thereby cooling the superconducting cable.

3. The space superconducting cable cryogenic system according to claim 1, characterized in that: The cryogenic loop heat pipe also includes a gas storage chamber (10), which is connected to the main evaporator (7) through the main steam loop (9) and communicates with the gas working medium in the cryogenic loop heat pipe to reduce pressure and prevent overpressure.

4. A space superconducting cable cryogenic system according to claim 1, characterized in that: The first cable joint (3) and the second cable joint (6) are cooled by the main evaporator (7) and the secondary evaporator (5), and the superconducting cable is cooled by the main liquid pipeline (17).

5. The space superconducting cable cryogenic system according to claim 1, characterized in that: The main evaporator (7) and the secondary evaporator (5) are both provided with grooves and micro-nano pore capillary structures made of porous materials. When the amount of supercooled working medium in the secondary evaporator (5) or the main evaporator (7) reaches a certain amount, the micro-nano pore capillary structure is infiltrated by the supercooled working medium and reaches the starting condition, the starting operation causes the liquid supercooled working medium inside to undergo a phase change.

6. The space superconducting cable cryogenic system according to claim 1, characterized in that: The refrigerator (1) comprises a compressor (13) and a refrigeration end (12); the refrigeration end (12) and the main condenser (15), and the refrigeration end (12) and the secondary condenser (14) are connected by welding, screw connection, powder metallurgy, cold chain connection or integrated processing and molding, and the compressor (13) refrigerates the refrigeration end (12).

7. The space superconducting cable cryogenic system according to claim 1, characterized in that: The superconducting cable comprises a cable (2), an insulating layer (18) and a low-temperature multi-layer thermal insulation component (19); wherein the cable (2) is wound on the main liquid pipeline (17) by a coaxial co-winding process; the cable (2) comprises a first cable and a second cable, and the insulating layer (18) isolates the first cable and the second cable by a coaxial sleeve method; and the cable (2) is wrapped with the low-temperature multi-layer thermal insulation component (19) on the outside.

8. The space superconducting cable cryogenic system according to claim 1, characterized in that: The main evaporator (7) and the secondary evaporator (5) are respectively connected to the first cable connector (3) and the second cable connector (6) by welding, screw connection or powder metallurgy connection, or are formed by integral processing.

9. The space superconducting cable cryogenic system according to claim 1, characterized in that: Depending on the length of the superconducting cable, a single or multiple refrigerators are connected in parallel to meet different cooling requirements.

10. The space superconducting cable cryogenic system according to claim 1, characterized in that: The low-temperature working medium in the cryogenic loop heat pipe is selected from helium, hydrogen, neon, nitrogen or oxygen.

Images