A liquid hydrogen storage tank and its storage method

Abstract

This invention discloses a liquid hydrogen storage tank and its storage method. The liquid hydrogen storage tank includes an outer tank, an inner tank coaxially disposed inside the outer tank, multiple outer rings disposed on the inner wall of the outer tank, a first groove formed on the inner wall of the outer rings, an inner ring slidably disposed on the inner wall of the first groove, a second groove formed on the inner wall of the inner ring, an auxiliary support assembly disposed on the inner wall of the second groove, and a pressure measuring mechanism disposed on the inner wall of the second groove for monitoring the pressure on a second arc-shaped block. The inner tank is equipped with a material inlet / outlet assembly for feeding and discharging. A magnetic levitation assembly for suspending the inner tank is disposed between the outer tank and the inner tank. This invention has the advantages of low heat leakage, adaptive adaptation to the thermal expansion and contraction of the inner cylinder, excellent low-temperature weather resistance, rapid emergency response, and multi-support synergistic stability. It can effectively prevent the inner tank from falling and being damaged when the main magnetic levitation support fails, while ensuring long-term liquid hydrogen storage efficiency and structural safety.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy storage technology, specifically to a liquid hydrogen storage tank and its storage method. Background Technology

[0002] With the rapid development of the global hydrogen energy industry, liquid hydrogen, as an efficient and clean energy carrier, is increasingly widely used in transportation, energy storage and other fields. The storage temperature of liquid hydrogen is extremely low (about -253℃), which puts forward stringent requirements on the thermal insulation performance and structural stability of storage equipment. At present, double-layer nested liquid hydrogen storage tanks are commonly used in industry to achieve long-term storage of liquid hydrogen. These tanks are usually composed of an inner cylinder (for holding liquid hydrogen), an outer cylinder (for isolating the external environment), and a vacuum interlayer between the inner and outer cylinders (for reducing heat conduction and heat convection). The core technical challenge is to ensure the stable positioning of the inner cylinder during storage while minimizing the transfer of external heat to the inner cylinder through the support structure, avoiding liquid hydrogen vaporization loss, and improving storage efficiency.

[0003] To address the severe heat leakage caused by thermal bridging resulting from solid contact in traditional rigid supports (such as booms and steel columns), existing technologies have gradually incorporated magnetic levitation support technology. Examples include the "magnetically levitation vacuum tank" disclosed in Chinese utility model patent CN217130954U and the "horizontal cryogenic container with magnetic levitation support" disclosed in Chinese invention patent CN115325429B. Both utilize the repulsive or attractive forces between magnets in the inner and outer cylinders to achieve non-contact levitation of the inner cylinder, effectively blocking the heat conduction path caused by solid supports and significantly reducing heat loss. However, existing magnetic levitation support technology still has significant application limitations. A complete solution for its auxiliary support system (for emergency backup in case of failure of the main magnetic levitation support) has not yet been developed, resulting in multiple challenges to the safety, reliability, and storage stability of liquid hydrogen storage tanks.

[0004] First, the main support of magnetic levitation has an unavoidable risk of failure (such as the disappearance of the magnetic field due to power failure, or demagnetization of the magnet at low temperatures for a long time). Existing auxiliary supports mostly adopt the same rigid solid structure as traditional storage tanks (such as metal brackets). Although they can bear the weight of the inner cylinder when magnetic levitation fails, the solid connection will reconstruct the heat conduction path between the inner and outer cylinders. External heat will be quickly transferred to the inner cylinder through the auxiliary support, which will lead to a significant increase in the vaporization rate of liquid hydrogen and seriously weaken the heat insulation performance and storage efficiency of the storage tank.

[0005] Secondly, during liquid hydrogen storage, the inner cylinder material (such as austenitic stainless steel) will undergo 1%-3% shrinkage deformation in an extremely low temperature environment of -253℃. However, most of the existing auxiliary supports are designed in a fixed position and cannot adaptively adjust with the thermal expansion and contraction of the inner cylinder. When the inner cylinder shrinks, an excessive gap is formed between the auxiliary support and the inner cylinder. When the magnetic levitation fails, it cannot accurately support the inner cylinder. When the inner cylinder expands slightly due to changes in the liquid hydrogen filling volume, the fixed support will squeeze the side wall of the inner cylinder. Long-term action can easily lead to stress concentration in the support structure, material fatigue, and even deformation of the inner cylinder, threatening the safety of the storage tank.

[0006] In addition, the storage temperature of liquid hydrogen is much lower than the "brittle transition temperature" of ordinary metals (such as the brittle transition temperature of carbon steel, which is about -40°C). The materials used in traditional auxiliary supports, such as ordinary steel and conventional spring steel, will quickly lose their toughness at extremely low temperatures and become brittle. The elastic modulus will decrease significantly. When the magnetic levitation fails, the brittle auxiliary support cannot absorb the impact load of the inner cylinder through elastic deformation and is prone to breakage. This will cause the inner cylinder to lose support and collide with the outer cylinder, resulting in damage to the storage tank and the risk of liquid hydrogen leakage.

[0007] Furthermore, the existing auxiliary support adjustment and triggering mechanisms are difficult to adapt to the vacuum and cryogenic environment of the storage tank, where the inner and outer cylinder layers are in a high vacuum state (typically below 10°C). - The grease relied upon by traditional mechanical adjustment structures (such as gear transmission and cable drive) will solidify and fail at extremely low temperatures (3Pa). In addition, there is no air to dissipate heat in a vacuum environment, and the heat generated by the friction of transmission components cannot be dissipated, which can easily lead to overheating and jamming of components. Magnetic levitation failure is mostly due to sudden situations (such as power failure or magnet failure). A jammed adjustment mechanism will prevent the auxiliary support from responding quickly. Even after the inner cylinder has shifted significantly under the action of gravity, it still cannot be effectively supported, further aggravating the safety hazards.

[0008] Finally, the problem of coordinated control of multiple auxiliary supports has not yet been solved. The weight distribution of the inner cylinder of the liquid hydrogen storage tank will change dynamically with the liquid hydrogen filling volume and liquid level fluctuations. The existing auxiliary supports lack a unified linkage control logic. When the magnetic levitation fails, some support points are overloaded due to the shift of the center of gravity (exceeding the material bearing limit), while some support points are idle. They cannot form a uniform support surface, which can easily lead to the tilting of the inner cylinder, local stress concentration, and even collision between the inner and outer cylinders, seriously affecting the structural stability of the storage tank.

[0009] In summary, while existing magnetic levitation support technology for liquid hydrogen storage tanks has solved the heat leakage problem of traditional rigid supports, the auxiliary support system for magnetic levitation failure scenarios still suffers from multiple defects, including severe heat leakage, inability to adapt to inner cylinder deformation, poor low-temperature performance, slow response, and insufficient coordination. These shortcomings make it difficult to meet the actual needs of long-term safe and efficient storage of liquid hydrogen. There is an urgent need for a new auxiliary support solution that can take into account "non-contact heat insulation", "low-temperature weather resistance", "rapid emergency response" and "coordinated stability" to make up for the deficiencies of existing technologies. Summary of the Invention

[0010] The purpose of this invention is to provide a liquid hydrogen storage tank and its storage method, which has the advantages of low heat leakage, adaptive adaptation to the thermal expansion and contraction of the inner cylinder, excellent low temperature weather resistance, rapid emergency response and multi-support coordinated stability, and can effectively avoid the inner tank falling and being damaged when the magnetic levitation main support fails. At the same time, it can ensure the long-term storage efficiency and structural safety of liquid hydrogen, and solve the problems in the prior art.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A liquid hydrogen storage tank includes an outer tank, an inner tank coaxially disposed inside the outer tank, a plurality of outer rings disposed on the inner wall of the outer tank, a first groove formed on the inner wall of the outer rings, an inner ring disposed within the first groove, a second groove formed on the inner wall of the inner ring, and an auxiliary support assembly and a pressure measuring mechanism disposed within the second groove. The pressure measuring mechanism is used to monitor the pressure of a second arc-shaped block. The inner ring can rotate around the center of the outer ring.

[0013] The inner tank is equipped with a feeding and discharging assembly for feeding and discharging materials;

[0014] A magnetic levitation assembly is provided between the outer tank and the inner tank to levitate the inner tank;

[0015] The outer tank is also equipped with a fall protection mechanism to prevent the inner tank from falling, and a controller is fixed to the side wall of the outer tank.

[0016] The auxiliary support assembly includes three first T-shaped blocks fixed to the inner wall of the second groove, second arc-shaped blocks fixed to both sides of the first T-shaped blocks, a slot one opened at the middle of one end of the second arc-shaped block, a first electromagnet fixed to the inner wall of the slot one, a third arc-shaped block with both ends respectively hinged to the second arc-shaped block, a slot two opened at the middle of one end of the third arc-shaped block, and a second electromagnet fixed to the inner wall of the slot two. The third arc-shaped block has a W-shaped structure with an arc transition at the inflection point. The concave surface of the second arc-shaped block faces the center of the second groove, and the middle part of the third arc-shaped block protrudes towards the concave surface of the second arc-shaped block.

[0017] It is worth noting that the auxiliary support component can prevent damage to the inner tank caused by it falling off when the magnetic levitation component fails.

[0018] Preferably, there is a gap at one end of the third arc-shaped block and the second arc-shaped block that are close to each other.

[0019] It is worth noting that the gap is designed to allow for radial displacement space, avoiding rigid contact. This allows for the adaptation to radial thermal expansion and contraction deformation of the inner tank during liquid hydrogen storage due to low-temperature shrinkage and recovery at room temperature, preventing inter-structure compression and wear.

[0020] Preferably, the pressure measuring mechanism includes a second pressure sensor fixed to the inner wall of the second tank, a spring fixed to the second pressure sensor at one end, and a connecting block fixed to the other end of the spring. The connecting block is fixedly connected to the outer peripheral surface of the second arc-shaped block.

[0021] It is worth noting that the workload of the auxiliary support components can be monitored in real time, providing pressure data support to the controller, preventing damage to the auxiliary support due to overload, and ensuring the reliability of the inner tank support system.

[0022] Preferably, the feeding and discharging assembly includes an inner tube that is fixed to the inner tank at one end, a first plug that is threaded to the other end of the inner tube, a discharge pipe that is fixed to the side wall of the outer tank at one end, and a second plug that is threaded to the other end of the discharge pipe. The discharge pipe and the inner tube are coaxially arranged, and the inner diameter of the discharge pipe is larger than the outer diameter of the inner tube.

[0023] It is worth noting that: the inner tube and the discharge tube are coaxially arranged and the inner diameter of the discharge tube is larger than the outer diameter of the inner tube, which reduces the cold leakage path during material feeding and discharging and reduces cold loss; the threaded first and second plugs have excellent sealing performance, which can prevent liquid hydrogen evaporation and leakage, and are easy to disassemble, making maintenance and cleaning convenient; the separate design of the inner tube passing through the inner tank and the discharge tube passing through the outer tank can reduce heat leakage caused by direct contact between the inner and outer tanks and adapt to the independent deformation requirements of the inner and outer tanks.

[0024] Preferably, the magnetic levitation assembly includes a first permanent magnet fixed to both ends of the inner tank, a third electromagnet fixed to the inner wall of the outer tank corresponding to the first permanent magnet, two second permanent magnets fixed to the side wall of the inner tank, two fourth electromagnets fixed to the inner wall of the outer tank respectively corresponding to the second permanent magnets, two third permanent magnets fixed to the side wall of the inner tank, two fifth electromagnets fixed to the inner wall of the outer tank respectively corresponding to the third permanent magnets, two fourth permanent magnets fixed to the side wall of the inner tank symmetrical about the center of the inner tank, and two sixth electromagnets fixed to the inner wall of the outer tank respectively corresponding to the fourth permanent magnets. The fourth and sixth electromagnets are symmetrical about the fifth electromagnets. Positioning blocks are fixed to both sides of the first, third, second, fourth, and fifth permanent magnets. The two second permanent magnets are symmetrical about the center of the inner tank, and the two third permanent magnets are symmetrical about the center of the inner tank.

[0025] It is worth noting that by adopting a symmetrical arrangement of multiple permanent magnets corresponding to electromagnets, multi-dimensional non-contact levitation of the inner tank in the circumference and axial direction can be achieved, which can avoid heat leakage caused by mechanical contact and significantly reduce the overall heat leakage rate.

[0026] Preferably, there is a gap between the first permanent magnet and the third electromagnet, a gap between the second permanent magnet and the fourth electromagnet, a gap between the third permanent magnet and the fifth electromagnet, and a gap between the fourth permanent magnet and the sixth electromagnet. At least two outer rings are provided, one outer ring is provided between the fifth electromagnet and the sixth electromagnet, and the other outer ring is provided between the fifth electromagnet and the fourth electromagnet.

[0027] It is worth noting that: gaps are reserved between each permanent magnet and electromagnet to provide displacement space for the thermal expansion and contraction of the inner tank, and to adapt to structural deformation under low temperature conditions.

[0028] Preferably, the anti-fall mechanism includes two supports fixed to the bottom surface of the inner wall of the outer tank, a first arc-shaped block fixed to the upper end of the supports, a plurality of rubber cylinders evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block, and a first pressure sensor fixed to the inner wall of the rubber cylinders.

[0029] It is worth noting that: the rubber cylinder has excellent cushioning performance, which can absorb the impact energy when the inner tank falls, and avoid damage caused by rigid collision between the inner tank and the outer tank; the first pressure sensor can monitor the pressure status of the rubber cylinder in real time, and trigger an alarm immediately once the inner tank falls and contacts the rubber cylinder, thus buying time for emergency handling; the concave design of the first arc block is adapted to the outer wall of the inner tank, ensuring that the force is evenly distributed when the inner tank falls, and avoiding local stress concentration.

[0030] Preferably, the anti-fall mechanism consists of two active pulling mechanisms and two passive pulling mechanisms. The active pulling mechanisms are used to lift the inner tank, and the passive pulling mechanisms are used to suspend the inner tank.

[0031] The active pulling mechanism comprises a fixed ring fixed to the side wall of the outer tank, a fixed body fixed to the upper end of the fixed ring, one end of a bent tube fixed to the upper end of the fixed body, a sealing box fixed to the other end of the bent tube, take-up rollers rotatably mounted on both sides of the inner wall of the sealing box, a servo motor fixed to one side of the sealing box, a second through hole opened through the side wall of the outer tank, a fixed block fixed to the top surface of the inner wall of the outer tank, and a first through hole opened through the fixed block. The first through hole and the second through hole correspond to each other. One end of the pull rope is fixed to the side wall of the take-up roller. The other end of the pull rope passes through the bent tube, the second through hole and the first through hole in sequence and extends into the interior of the outer tank. A circular loop is fixed to the other end of the pull rope, and the loop is fitted onto the side wall of the inner tank.

[0032] The output shaft of the servo motor passes through the sealed box and is fixed to the rotating shaft of the take-up roller;

[0033] The passive tension mechanism includes two fixed blocks fixed to the top surface of the inner wall of the outer tank, a suspension rope fixed to both ends of the fixed blocks, and multiple limiting rings fixed to the side wall of the inner tank. The suspension rope is sleeved on the side wall of the inner tank and located between two adjacent limiting rings, and the rope is also located between two adjacent limiting rings.

[0034] It is worth noting that in the active pulling mechanism, the servo motor drives the take-up roller to adjust the length of the pull rope, which can actively control the lifting and lowering of the inner tank, adapting to the needs of inner tank maintenance, thermal deformation compensation or magnetic levitation system debugging; the design of the sealing box and the bend can prevent heat leakage and liquid hydrogen leakage at the pull rope exit point, and the rope sleeve is fixed with the limit ring to avoid the inner tank tilting caused by the pull rope displacement;

[0035] In the passive tension mechanism, the suspension rope is sleeved between the inner tank and the limiting ring, which can suspend the middle tank for a long time, forming real-time protection. This can prevent the inner tank from suddenly falling when the magnetic levitation fails. In addition, the design of multiple limiting rings can limit the axial displacement of the sleeve and suspension rope, ensuring the stability of the tension application point and preventing the inner tank from shifting.

[0036] The present invention also provides a method for storing liquid hydrogen in a liquid hydrogen storage tank, comprising a liquid hydrogen storage tank as described above, and the steps of the storage method are as follows:

[0037] Step 1: Equipment Pre-treatment and Targeted Safety Inspection

[0038] Connect the power supply to the outer tank sidewall controller, start the system self-test program, and first check the circuit connection stability of the first permanent magnet, third electromagnet, second permanent magnet, fourth electromagnet, third permanent magnet, fifth electromagnet, fourth permanent magnet, and sixth electromagnet in the magnetic levitation assembly. Confirm that each positioning block is firmly fixed and that the gaps between the first permanent magnet and the third electromagnet, the second permanent magnet and the fourth electromagnet, the third permanent magnet and the fifth electromagnet, and the fourth permanent magnet and the sixth electromagnet meet the design requirements.

[0039] The auxiliary support components were inspected in detail: a low-intensity test current was passed to the first and second electromagnets through the controller to verify the opening and closing flexibility of the third arc block, confirm the fitting gap between the concave surface of the second arc block and the inner tank side wall, and check the low-temperature toughness of the second and third arc blocks.

[0040] Check the pressure measuring mechanism: Read the initial value of the second pressure sensor through the controller to confirm that there is no jamming between the spring and the connecting block, and ensure that the spring's elastic coefficient is stable at the extremely low temperature of -253℃;

[0041] Check the fall arrest mechanism: If the fall arrest mechanism consists of two active pulling mechanisms and two passive pulling mechanisms, confirm the low-temperature weather resistance of the rope and the reliability of the limit ring fixation. Start the servo motor to drive the take-up roller to test the response speed of the rope. If the fall arrest mechanism consists of two supports fixed to the bottom of the inner wall of the outer tank, a first arc-shaped block fixed to the upper end of the supports, multiple rubber tubes evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block, and a first pressure sensor fixed to the inner wall of the rubber tubes, check the low-temperature elasticity of the rubber tubes and the low-temperature sensitivity of the first pressure sensor.

[0042] Check the feeding and discharging components: confirm that the first plug of the inner tube and the second plug of the discharge tube are properly sealed, and that the discharge tube is coaxial with the inner tube and there are no foreign objects in the gap.

[0043] Step 2: Activate the magnetic levitation component to achieve coaxial levitation of the inner tank.

[0044] The controller activates the magnetic levitation assembly, and a preset current is supplied to the third, fourth, fifth, and sixth electromagnets. The repulsive force between the permanent magnet and the electromagnets is used to achieve non-contact levitation of the inner tank.

[0045] The controller monitors the coaxiality of the inner tank in real time and fine-tunes the current of each electromagnet: if the inner tank shifts to a certain side, the current of the corresponding electromagnet is increased (e.g., if it shifts to the fourth electromagnet side, the current of the fourth electromagnet is increased).

[0046] If the inner tank is detected to have initially shrunk due to low temperature (gap increases by more than 1.5mm), "same current" (generating repulsive force) is immediately passed to the first electromagnet and the second electromagnet, driving the middle part of the third arc block to move closer to the inner tank around the hinge point, reducing the gap to the design range of 0.8-1.2mm, and ensuring that the inner tank and the outer tank are strictly coaxial.

[0047] After the suspension stabilizes, keep the current of the magnetic levitation component stable, and record the initial current parameters, the position data of the inner tank, and the test current parameters of the first and second electromagnets as a reference for subsequent monitoring.

[0048] Step 3: Complete the liquid hydrogen feeding through the feed and discharge assembly.

[0049] Unscrew the second plug of the outlet pipe and the first plug of the inner pipe in sequence to seal the liquid hydrogen feed pipe to the inner pipe;

[0050] Control the liquid hydrogen feeding rate (not exceeding 5L per second, adjusted according to the tank volume) to avoid sudden pressure rise in the inner tank causing structural deformation; during the feeding process, monitor the weight change of the inner tank in real time through the controller (record once every 10 seconds), and simultaneously fine-tune the current of the magnetic levitation component (if the weight increases, appropriately increase the current of the third and fifth electromagnets) to maintain the stable coaxial suspension of the inner tank.

[0051] When the liquid hydrogen storage in the inner tank reaches the design limit (e.g., 90% of the volume), stop feeding, tighten the first stopper and the second stopper in sequence, and close the feed pipe valve.

[0052] Step 4: Real-time monitoring of the storage process triggers the activation of auxiliary support and fall protection mechanisms.

[0053] Monitoring of normal operation of magnetic levitation: Record the current of each electromagnet, the gap data of each permanent magnet and each electromagnet in the magnetic levitation component every 30 minutes. If the current fluctuation exceeds 10% or the gap deviation exceeds 2mm, it is judged that the magnetic levitation part has failed and the auxiliary support component is immediately activated.

[0054] Emergency activation of auxiliary support components: Adjust the current type and intensity of the first and second electromagnets according to the deformation state of the inner tank.

[0055] If the pressure measuring mechanism reports that the inner tank has shrunk due to continuous low temperature (gap exceeding 1.5mm), "same current" is passed through the two electromagnets (generating repulsive force), pushing the middle of the third arc block to bulge away from the second arc block (i.e., towards the inner tank), reducing the gap with the inner tank (not complete contact, retaining a 1mm gap to accommodate subsequent minor deformations).

[0056] If the inner tank expands slightly due to fluctuations in the liquid hydrogen filling amount (the second pressure sensor detects that the pressure exceeds 30N), an "opposite current" (generating attraction) is passed through the two electromagnets, pulling the middle of the third arc block towards the concave surface of the second arc block to bend and contract, so that the third arc block is moved away from the inner tank, avoiding compression that could cause deformation of the inner tank.

[0057] If the pressure value exceeds 50N, the current intensity needs to be increased while adjusting the current type to strengthen the bending, contraction or bulging force of the third arc block, and the magnetic levitation current needs to be finely adjusted to correct the position of the inner tank.

[0058] Emergency preparation for fall arrest mechanisms: If the magnetic levitation completely fails (e.g., the current of each electromagnet suddenly drops to 0A), immediately activate the fall arrest mechanism, which includes:

[0059] If a fall prevention mechanism consisting of two active pulling mechanisms and two passive pulling mechanisms is adopted: the controller sends a drive signal to the servo motor, the servo motor drives the take-up roller to rotate at high speed to tighten the pull rope, and the pull rope hangs the inner tank between two adjacent limit rings through the rope loop. The response time of the entire start-up process does not exceed 2 seconds, ensuring that the inner tank does not sink significantly.

[0060] If a fall prevention mechanism is adopted, consisting of two supports fixed to the bottom of the inner wall of the outer tank, a first arc-shaped block fixed to the upper end of the supports, multiple rubber cylinders evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block, and a first pressure sensor fixed to the inner wall of the rubber cylinder: the pressure value of the first pressure sensor is monitored in real time. When the inner tank falls to contact the rubber cylinder due to gravity, the first pressure sensor detects that the pressure exceeds 100N, confirming that the rubber cylinder supports the weight of the inner tank through elastic deformation, thus preventing the inner tank from directly impacting the inner wall of the outer tank.

[0061] Comprehensive data recording: every hour, the magnetic levitation current, auxiliary support pressure, current type and intensity of the first and second electromagnets, and the status parameters of the fall arrest mechanism (tether tension or rubber cylinder pressure) are recorded to ensure that the inner tank does not shift and that liquid hydrogen does not leak.

[0062] Step 5: Regular maintenance and calibration to adapt to low-temperature environments and structural deformation.

[0063] Daily maintenance: Check the circuits of the first and second electromagnets of the auxiliary support components, and test the opening and closing angle range of the third arc block by passing "same current" and "opposite current" through them respectively (to ensure that the inner tank can still be accurately aligned when it shrinks by 2mm or expands by 1mm). Check the low-temperature toughness of the pull rope and suspension rope of the fall protection mechanism (no embrittlement cracks).

[0064] Weekly calibration: Disconnect the power supply to the magnetic levitation component, simulate the failure of the magnetic levitation part and the shrinkage / expansion of the inner tank, test the response time of the auxiliary support component (≤1.5 seconds), calibrate the second pressure sensor (error controlled within ±2N), and verify the low-temperature elasticity of the spring (it can return to its original shape after being compressed by 5mm).

[0065] Monthly in-depth maintenance: Clean impurities from the surface of the first permanent magnet, the third electromagnet, etc., check the fixing of the positioning block, and test the maximum load-bearing capacity of the anti-fall mechanism (must exceed 1.2 times the weight of the inner tank when full of liquid).

[0066] Step Six: Controlled Discharge and System Closure

[0067] Preparation before discharge: Adjust the magnetic levitation component through the controller, increase the current of the third electromagnet to stabilize the axial position of the inner tank, adjust the current of the fourth and sixth electromagnets, and at the same time monitor whether the inner tank shrinks due to the reduction of liquid hydrogen. If necessary, pass "same current" to the first and second electromagnets to drive the third arc block to move closer, so that the inner tank remains horizontally and coaxially suspended.

[0068] Controlled discharge: Unscrew the second and first plugs to seal the discharge pipe to the inner tube and control the discharge speed (not exceeding 8L per second) to avoid a sudden drop in the pressure of the inner tank. During the discharge process, monitor the position and deformation of the inner tank every 15 seconds. If shrinkage causes the gap to increase, push the third arc block to fill the gap through the "same current". If local expansion occurs, pull the third arc block to avoid it through the "opposite current", or start the pull rope to correct it.

[0069] Final cleaning: When the liquid hydrogen in the inner tank drops to the design lower limit (e.g., 5% of the volume), stop discharging and flush the inner tube and the inner wall of the discharge pipe with nitrogen (purity ≥99.99%).

[0070] System shutdown: Gradually reduce the current of the magnetic levitation component (10% reduction every 5 seconds), while simultaneously supplying low-intensity "opposite current" to the first and second electromagnets, causing the third arc-shaped block to slowly move away from the inner tank;

[0071] Wait for the inner tank to slowly descend to the anti-fall mechanism, then read the value of the first pressure sensor (it is normal if it is stable in the range of 30-80N); turn off the controller power, record the stored data (feed amount, discharge amount, number of emergency starts, electromagnet current adjustment records, etc.), and complete the equipment ledger registration.

[0072] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0073] 1. This invention effectively solves the technical defect of "severe heat leakage of auxiliary support when magnetic levitation fails" in the existing magnetic levitation support technology for liquid hydrogen storage tanks, ensuring the long-term storage efficiency of liquid hydrogen. Specifically, the magnetic levitation component achieves the levitation of the inner tank through the non-contact repulsive force between the first to fourth permanent magnets and the third to sixth electromagnets, and a gap is reserved between each permanent magnet and electromagnet to completely block mechanical contact thermal bridges; the auxiliary support component only approaches the inner tank through the elastic deformation of the third arc block when magnetic levitation fails, and a radial gap is reserved between the third arc block and the second arc block, and a 1mm gap is maintained with the inner tank to avoid long-term solid connection forming a heat conduction path; the inlet and outlet components adopt a separate coaxial design of inner tube and outlet pipe, with the inner tube only connected to the inner tank and the outlet pipe only connected to the outer tank, and the two have no direct contact to reduce heat transfer. The above structure, combined with the vacuum jacket between the outer tank and the inner tank, can reduce the heat leakage rate to less than 30% of the existing technology, effectively avoiding vaporization loss of liquid hydrogen due to external heat transfer, and significantly improving the liquid hydrogen storage efficiency;

[0074] 2. This invention overcomes the technical limitation of existing auxiliary supports that "cannot adapt to the thermal expansion and contraction of the inner tank," thus avoiding structural stress damage. The initial gap between the third and second arc-shaped blocks can directly accommodate the minute thermal expansion and contraction of the inner tank within ±1mm. When the gap exceeds 1.5mm due to low-temperature contraction of the inner tank, the controller supplies the same current to the first and second electromagnets of the auxiliary support component. The resulting repulsive force pushes the middle of the third arc-shaped block to bulge towards the inner tank, adjusting the gap to 0.8-1.2mm. When the pressure detected by the second pressure sensor exceeds 30N due to the fluctuation and expansion of the inner tank during liquid hydrogen filling, the controller supplies opposite current to the two electromagnets. The resulting attractive force pulls the middle of the third arc-shaped block to contract towards the concave surface of the second arc-shaped block, avoiding rigid compression between the inner tank and the support structure. At the same time, the gap between the permanent magnet and electromagnet of the magnetic levitation component provides displacement redundancy for the axial and circumferential deformation of the inner tank, realizing real-time adaptation between the auxiliary support and the deformation of the inner tank. This prevents support failure caused by support gaps when the inner tank contracts and avoids deformation of the inner tank and support fatigue caused by rigid compression when the inner tank expands, ensuring the integrity of the storage tank structure.

[0075] 3. This invention solves the technical problems of "low-temperature embrittlement" and "slow emergency response" in existing auxiliary supports, improving reliability and emergency failure protection capabilities in extremely low-temperature environments. Regarding low-temperature performance, the third and second arc-shaped blocks of the auxiliary support are made of austenitic stainless steel 316LN (impact toughness ≥60J / cm² at -253℃), the rubber cylinder of the fall arrestor is made of low-temperature resistant fluororubber (maintaining elasticity even at -260℃), the spring of the pressure measuring mechanism is made of Inconel 718 low-temperature alloy steel wire (elastic modulus fluctuation <5% at -253℃), and the first and second pressure sensors use a low-temperature encapsulation process (operating temperature -270~80℃), ensuring that all key components maintain toughness and functional stability at extremely low temperatures. Regarding emergency response, the system monitors the electromagnetic field of the magnetic levitation component every 30 minutes. Regarding the iron current and gap, when the current fluctuation exceeds 10% or the gap deviation exceeds 2mm, the auxiliary support can be triggered within 0.5 seconds. If the magnetic levitation completely fails (the current drops to 0A), the servo motor of the active anti-fall mechanism can drive the take-up roller to tighten the pull rope within 2 seconds. The inner tank is suspended by the rope to prevent it from sinking. The suspension rope of the passive anti-fall mechanism is always fitted between the inner tank's limit rings, so it can bear the weight of the inner tank at the moment of magnetic levitation failure. Combined with the real-time data feedback from the second pressure sensor (sampling frequency 10Hz) of the pressure measuring mechanism, it completely breaks through the limitations of traditional mechanical adjustment such as "low temperature jamming and slow response", effectively avoiding the risk of inner tank displacement and impact.

[0076] 4. This invention also solves the technical defect of insufficient coordination in existing multi-support systems, ensuring the overall stability of the storage tank support, and the design of the scheme has excellent rationality and safety redundancy. The controller can link the magnetic levitation component, auxiliary support component and anti-fall mechanism. When the center of gravity of the inner tank shifts due to liquid hydrogen fluctuations, it synchronously fine-tunes the current of the magnetic levitation electromagnet (such as increasing the current on the weight-increasing side), the pressure of the auxiliary support (strengthening the arc-shaped block protrusion on the offset side) and the tension of the anti-fall rope (tightening the rope on the tilted side); the multiple sets of outer rings of the auxiliary support component (at least 2, distributed between the fourth and sixth electromagnets) form a uniform circumferential support. The two sets of active pulling mechanisms and two sets of passive pulling mechanisms of the anti-fall mechanism are symmetrically arranged. The loop rope and the suspension rope are both limited between the adjacent limiting rings of the inner tank to ensure uniform support force points and avoid local overload. Meanwhile, the three-tiered support system constructed by this invention, consisting of "magnetic levitation main support - auxiliary support emergency backup - fall arrest mechanism ultimate protection," has no functional redundancy or missing components; the electrical signal drive method of the electromagnet and servo motor is adapted to the vacuum interlayer of the inner and outer tanks, eliminating mechanical transmission lubrication failure issues; the pressure sensor and current monitoring form a data closed loop, making adjustment decisions traceable; the active / passive dual-mode of the fall arrest mechanism and the reserved gaps in the auxiliary support provide dual protection for extreme scenarios such as power outages and magnet demagnetization, eliminating the risk of single-point failure and fully meeting the actual needs of long-term safe and efficient storage of liquid hydrogen. Attached Figure Description

[0077] Figure 1 The diagram shown is a three-dimensional structural schematic of the present invention;

[0078] Figure 2 The diagram shown is a cross-sectional perspective view of the outer can of the present invention;

[0079] Figure 3 The diagram shown is a three-dimensional structural schematic of the outer ring of the present invention;

[0080] Figure 4 The diagram shown is a three-dimensional disassembled structural diagram of the outer ring, inner ring, and auxiliary support components of the present invention;

[0081] Figure 5 The diagram shown is a three-dimensional structural schematic of the first T-shaped block of the present invention;

[0082] Figure 6 The diagram shown is a three-dimensional structural schematic of the feeding and discharging assembly of the present invention.

[0083] Figure 7 The diagram shown is a three-dimensional structural schematic of a first embodiment of the fall protection mechanism of the present invention;

[0084] Figure 8 The diagram shown is a three-dimensional structural schematic of a second embodiment of the fall protection mechanism of the present invention;

[0085] Figure 9The diagram shown is a three-dimensional cross-sectional view of a second embodiment of the fall arrest mechanism of the present invention.

[0086] Figure 10 The diagram shown is a three-dimensional structural schematic of the second embodiment of the fall protection mechanism of the present invention.

[0087] Figure 11 The diagram shown is a three-dimensional structural schematic of the magnetic levitation component of the present invention.

[0088] Reference numerals: 1. Outer tank; 101. Support; 102. First arc-shaped block; 103. Rubber cylinder; 104. First pressure sensor; 2. Discharge pipe; 201. Inner tube; 202. First stopper; 203. Second stopper; 3. Inner tank; 4. Outer ring; 5. First groove; 6. Inner ring; 7. Second groove; 8. First T-shaped block; 9. Second pressure sensor; 10. Spring; 11. Connecting block; 12. Second arc-shaped block; 13. First electromagnet; 14. Third arc-shaped block; 15. 16. Second electromagnet; 17. Controller; 18. Fixing block; 19. Lifting rope; 20. Limiting ring; 21. First through hole; 22. Fixing ring; 23. Fixing body; 24. Bend; 25. Sealing box; 26. Take-up roller; 27. Pull rope; 28. Second through hole; 29. ​​Servo motor; 30. First permanent magnet; 31. Third electromagnet; 32. Second permanent magnet; 33. Third permanent magnet; 34. Fifth electromagnet; 35. Fourth permanent magnet; 36. Sixth electromagnet. Detailed Implementation

[0089] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0090] To address the problems in existing technologies for magnetically levitated liquid hydrogen storage tanks, including severe heat leakage in the auxiliary support system, inability to adapt to the extremely low-temperature thermal expansion and contraction deformation of the inner tank, easy material embrittlement and failure at low temperatures, slow response due to jamming of the adjustment / triggering mechanism in a vacuum cryogenic environment, and lack of coordinated control among multiple support sets leading to tilting damage of the inner tank, thereby affecting liquid hydrogen storage efficiency and tank structural safety, the following technical solution is proposed. Please refer to [link / reference]. Figures 1-11 ;

[0091] A liquid hydrogen storage tank includes an outer tank 1, an inner tank 3 coaxially disposed inside the outer tank 1, a plurality of outer rings 4 disposed on the inner wall of the outer tank 1, a first groove 5 opened on the inner wall of the outer rings 4, an inner ring 6 disposed in the first groove 5, a second groove 7 opened on the inner wall of the inner ring 6, and an auxiliary support assembly and a pressure measuring mechanism disposed in the second groove 7. The pressure measuring mechanism is used to monitor the pressure of the second arc-shaped block 12. The inner ring 6 can rotate around the center of the outer ring 4.

[0092] The inner tank 3 is equipped with a feeding and discharging assembly for feeding and discharging materials;

[0093] A magnetic levitation assembly for suspending the inner tank 3 is provided between the outer tank 1 and the inner tank 3;

[0094] The outer tank 1 is also equipped with a fall protection mechanism to prevent the inner tank 3 from falling, and a controller 16 is fixedly connected to the side wall of the outer tank 1.

[0095] In this embodiment, specifically, the auxiliary support component includes three first T-shaped blocks 8 fixed to the inner wall of the second groove 7, second arc-shaped blocks 12 fixed to both sides of the first T-shaped blocks 8, a slot 1 opened at the middle of one end of the second arc-shaped block 12, a first electromagnet 13 fixed to the inner wall of the slot 1, a third arc-shaped block 14 with both ends respectively hinged to the second arc-shaped block 12, a slot 2 opened at the middle of one end of the third arc-shaped block 14, and a second electromagnet 15 fixed to the inner wall of the slot 2. The third arc-shaped block 14 has a W-shaped structure and the inflection point of the structure is an arc transition. The concave surface of the second arc-shaped block 12 faces the center of the second groove 7, and the middle part of the third arc-shaped block 14 protrudes towards the concave surface of the second arc-shaped block 12.

[0096] In this embodiment, specifically, there is a gap between the ends of the third arc-shaped block 14 and the second arc-shaped block 12 that are close to each other.

[0097] In this embodiment, the pressure measuring mechanism specifically includes a second pressure sensor 9 fixed to the inner wall of the second groove 7, a spring 10 fixed to the second pressure sensor 9 at one end, and a connecting block 11 fixed to the other end of the spring 10. The connecting block 11 is fixedly connected to the outer peripheral surface of the second arc-shaped block 12.

[0098] In this embodiment, specifically, the feeding and discharging assembly includes an inner tube 201 that is fixed to the inner tank 3 at one end, a first plug 202 that is threaded onto the other end of the inner tube 201, a discharge pipe 2 that is fixed to the side wall of the outer tank 1 at one end, and a second plug 203 that is threaded onto the other end of the discharge pipe 2. The discharge pipe 2 and the inner tube 201 are coaxially arranged, and the inner diameter of the discharge pipe 2 is larger than the outer diameter of the inner tube 201.

[0099] In this embodiment, specifically, the magnetic levitation assembly includes a first permanent magnet 29 fixed to both ends of the inner tank 3, a third electromagnet 30 fixed to the inner wall of the outer tank 1 corresponding to the first permanent magnet 29, two second permanent magnets 31 fixed to the side wall of the inner tank 3, two fourth electromagnets 32 fixed to the inner wall of the outer tank 1 respectively corresponding to the second permanent magnets 31, two third permanent magnets 33 fixed to the side wall of the inner tank 3, two fifth electromagnets 34 fixed to the inner wall of the outer tank 1 respectively corresponding to the third permanent magnets 33, and two electromagnets 34 fixed to the side wall of the inner tank 3 that are mutually opposite about the center of the inner tank 3. The fourth permanent magnet 35 and two sixth electromagnets 36, which are fixed to the inner wall of the outer tank 1 and are respectively corresponding to the fourth permanent magnet 35, are symmetrical about the fifth electromagnet 34. The first permanent magnet 29, the third electromagnet 30, the second permanent magnet 31, the fourth electromagnet 32, the third permanent magnet 33, the fifth electromagnet 34, the fourth permanent magnet 35 and the sixth electromagnet 36 are fixed to both sides with positioning blocks. The two second permanent magnets 31 are symmetrical about the center of the inner tank 3 and the two third permanent magnets 33 are symmetrical about the center of the inner tank 3.

[0100] In this embodiment, specifically, there is a gap between the first permanent magnet 29 and the third electromagnet 30, a gap between the second permanent magnet 31 and the fourth electromagnet 32, a gap between the third permanent magnet 33 and the fifth electromagnet 34, and a gap between the fourth permanent magnet 35 and the sixth electromagnet 36. At least two outer rings 4 are provided, one outer ring 4 is provided between the fifth electromagnet 34 and the sixth electromagnet 36, and the other outer ring 4 is provided between the fifth electromagnet 34 and the fourth electromagnet 32.

[0101] In this embodiment, the anti-fall mechanism specifically includes two supports 101 fixed to the bottom surface of the inner wall of the outer tank 1, a first arc-shaped block 102 fixed to the upper end of the support 101, a plurality of rubber cylinders 103 evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block 102, and a first pressure sensor 104 fixed to the inner wall of the rubber cylinder 103.

[0102] In this embodiment, specifically, the anti-fall mechanism consists of two active pulling mechanisms and two passive pulling mechanisms. The active pulling mechanisms are used to lift the inner tank 3, and the passive pulling mechanisms are used to suspend the inner tank 3.

[0103] The active pulling mechanism includes a fixed ring 21 fixed to the side wall of the outer tank 1, a fixed body 22 fixed to the upper end of the fixed ring 21, one end of a bent pipe 23 fixed to the upper end of the fixed body 22, a sealing box 24 fixed to the other end of the bent pipe 23, a take-up roller 25 rotatably mounted on both sides of the inner wall of the sealing box 24, a servo motor 28 fixed to one side of the sealing box 24, a second through hole 27 through the side wall of the outer tank 1, a fixed block 17 fixed to the top surface of the inner wall of the outer tank 1, and a first through hole 20 through the fixed block 17. The first through hole 20 and the second through hole 27 correspond to each other. One end of a pull rope 26 is fixed to the side wall of the take-up roller 25. The other end of the pull rope 26 passes through the bent pipe 23, the second through hole 27 and the first through hole 20 in sequence and extends into the interior of the outer tank 1. A circular loop is fixed to the other end of the pull rope 26. The loop is fitted onto the side wall of the inner tank 3.

[0104] The output shaft of the servo motor 28 passes through the sealing box 24 and is fixed to the rotating shaft of the take-up roller 25;

[0105] The passive tension mechanism includes two fixed blocks 17 fixed to the top surface of the inner wall of the outer tank 1, a suspension rope 18 fixed to both ends of the fixed blocks 17, and multiple limiting rings 19 fixed to the side wall of the inner tank 3. The suspension rope 18 is sleeved on the side wall of the inner tank 3 and located between two adjacent limiting rings 19. The rope is also located between two adjacent limiting rings 19.

[0106] The present invention also provides a method for storing liquid hydrogen in a liquid hydrogen storage tank, comprising a liquid hydrogen storage tank as described above, and the steps of the storage method are as follows:

[0107] Step 1: Equipment Pre-treatment and Targeted Safety Inspection

[0108] Connect the power supply to the controller 16 on the side wall of the outer tank 1, start the system self-test program, and first check the stability of the circuit connection of the first permanent magnet 29, the third electromagnet 30, the second permanent magnet 31, the fourth electromagnet 32, the third permanent magnet 33, the fifth electromagnet 34, the fourth permanent magnet 35, and the sixth electromagnet 36 in the magnetic levitation assembly. Confirm that each positioning block is firmly fixed and that the gaps between the first permanent magnet 29 and the third electromagnet 30, the second permanent magnet 31 and the fourth electromagnet 32, the third permanent magnet 33 and the fifth electromagnet 34, and the fourth permanent magnet 35 and the sixth electromagnet 36 meet the design requirements.

[0109] The auxiliary support components were inspected in detail: a low-intensity test current was supplied to the first electromagnet 13 and the second electromagnet 15 through the controller 16 to verify the opening and closing flexibility of the third arc block 14, confirm the fitting gap between the concave surface of the second arc block 12 and the side wall of the inner tank 3, and at the same time check the low-temperature toughness of the second arc block 12 and the third arc block 14.

[0110] Check the pressure measuring mechanism: Read the initial value of the second pressure sensor 9 through the controller 16 to confirm that there is no jamming between the spring 10 and the connecting block 11, and ensure that the elastic coefficient of the spring 10 is stable at the extremely low temperature of -253℃.

[0111] Check the fall protection mechanism: If the fall protection mechanism consists of two active pulling mechanisms and two passive pulling mechanisms, confirm the low-temperature weather resistance of the suspension rope 18 and the reliable fixation of the limit ring 19. Start the servo motor 28 to drive the take-up roller 25 and test the response speed of the pull rope 26. If the fall protection mechanism consists of two supports fixed to the bottom of the inner wall of the outer tank, a first arc-shaped block fixed to the upper end of the supports, multiple rubber cylinders evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block, and a first pressure sensor fixed to the inner wall of the rubber cylinder, check the low-temperature elasticity of the rubber cylinder 103 and the low-temperature sensitivity of the first pressure sensor 104.

[0112] Check the feeding and discharging components: confirm that the first plug 202 of the inner tube 201 and the second plug 203 of the discharge tube 2 are properly sealed, and that the discharge tube 2 is coaxial with the inner tube 201 and there are no foreign objects in the gap.

[0113] Step 2: Activate the magnetic levitation component to achieve coaxial levitation of the inner tank 3.

[0114] The magnetic levitation assembly is activated by the controller 16, and a preset current is supplied to the third electromagnet 30, the fourth electromagnet 32, the fifth electromagnet 34, and the sixth electromagnet 36. The repulsive force between the permanent magnet and the electromagnet is used to achieve non-contact levitation of the inner tank 3.

[0115] The coaxiality of the inner tank 3 is monitored in real time by the controller 16, and the current of each electromagnet is finely adjusted: if the inner tank 3 shifts to a certain side, the current of the corresponding electromagnet is increased (e.g., if it shifts to the side of the fourth electromagnet 32, the current of the fourth electromagnet 32 ​​is increased).

[0116] If the inner tank 3 is detected to have initially contracted due to low temperature (gap increases by more than 1.5mm), "same current" (generating repulsive force) is immediately passed to the first electromagnet 13 and the second electromagnet 15, driving the middle part of the third arc block 14 to move closer to the inner tank 3 around the hinge point, reducing the gap to the design range of 0.8-1.2mm, and ensuring that the inner tank 3 and the outer tank 1 are strictly coaxial.

[0117] After the suspension stabilizes, keep the current of the magnetic levitation component stable, and record the initial current parameters, the position data of the inner tank 3, and the test current parameters of the first electromagnet 13 and the second electromagnet 15 as the benchmark for subsequent monitoring.

[0118] Step 3: Complete the liquid hydrogen feeding through the feed and discharge assembly.

[0119] Unscrew the second plug 203 of the discharge pipe 2 and the first plug 202 of the inner tube 201 in sequence to seal the liquid hydrogen feed pipe to the inner tube 201.

[0120] Control the liquid hydrogen feeding rate (not exceeding 5L per second, adjusted according to the tank volume) to avoid sudden pressure rise in inner tank 3 causing structural deformation; during the feeding process, monitor the weight change of inner tank 3 in real time through controller 16 (record once every 10 seconds), and simultaneously fine-tune the current of magnetic levitation component (if the weight increases, appropriately increase the current of the third electromagnet 30 and the fifth electromagnet 34) to maintain stable coaxial suspension of inner tank 3.

[0121] When the liquid hydrogen storage in inner tank 3 reaches the design limit (e.g., 90% of the volume), stop feeding, tighten the first stopper 202 and the second stopper 203 in sequence, and close the feed pipe valve.

[0122] Step 4: Real-time monitoring of the storage process triggers the activation of auxiliary support and fall protection mechanisms.

[0123] Monitoring of normal operation of magnetic levitation: Record the current of each electromagnet in the magnetic levitation component, the gap data of each permanent magnet 29 and each electromagnet 30 every 30 minutes. If the current fluctuation exceeds 10% or the gap deviation exceeds 2mm, it is judged that the magnetic levitation part has failed and the auxiliary support component is immediately activated.

[0124] Emergency activation of auxiliary support components: Adjust the current type and intensity of the first electromagnet 13 and the second electromagnet 15 according to the deformation state of the inner tank 3.

[0125] If the pressure measuring mechanism reports that the inner tank 3 has shrunk due to continuous low temperature (gap exceeding 1.5mm), "same current" (generating repulsive force) is passed to the two electromagnets, pushing the middle part of the third arc block 14 to bulge away from the second arc block 12 (i.e. the direction of the inner tank 3), reducing the gap with the inner tank 3 (not in complete contact, retaining a 1mm gap to accommodate subsequent small deformations).

[0126] If the inner tank 3 expands slightly due to fluctuations in the liquid hydrogen filling amount (the second pressure sensor 9 detects that the pressure exceeds 30N), "opposite current" is passed to the two electromagnets (generating attraction), pulling the middle part of the third arc block 14 towards the concave surface of the second arc block 12 to bend and contract, so that the third arc block 14 moves away from the inner tank 3, avoiding compression that could cause deformation of the inner tank.

[0127] If the pressure value exceeds 50N, the current intensity needs to be increased while adjusting the current type to strengthen the bending, contraction or bulging force of the third arc block 14, and the magnetic levitation current should be finely adjusted to correct the position of the inner tank 3.

[0128] Emergency preparation for fall arrest mechanisms: If the magnetic levitation completely fails (e.g., the current of each electromagnet suddenly drops to 0A), immediately activate the fall arrest mechanism, which includes:

[0129] If a fall prevention mechanism consisting of two active pulling mechanisms and two passive pulling mechanisms is adopted: the controller 16 sends a drive signal to the servo motor 28, the servo motor 28 drives the take-up roller 25 to rotate at high speed to tighten the pull rope 26, and the pull rope 26 hangs the inner tank 3 between two adjacent limit rings 19 through the rope loop. The response time of the entire start-up process does not exceed 2 seconds, ensuring that the inner tank 3 does not sink significantly.

[0130] If a fall prevention mechanism is adopted, consisting of two supports fixed to the bottom of the inner wall of the outer tank, a first arc-shaped block fixed to the upper end of the supports, multiple rubber cylinders evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block, and a first pressure sensor fixed to the inner wall of the rubber cylinder: the pressure value of the first pressure sensor 104 is monitored in real time. When the inner tank 3 falls to contact the rubber cylinder 103 due to gravity, the first pressure sensor 104 detects that the pressure exceeds 100N, confirming that the rubber cylinder 103 supports the weight of the inner tank 3 through elastic deformation, thus preventing the inner tank 3 from directly impacting the inner wall of the outer tank 1;

[0131] Comprehensive data recording: every hour, the magnetic levitation current, auxiliary support pressure, current type and intensity of the first electromagnet 13 and the second electromagnet 15, and the status parameters of the anti-fall mechanism (tension of the rope 26 or pressure of the rubber tube 103) are recorded to ensure that the inner tank 3 does not shift and that liquid hydrogen does not leak.

[0132] Step 5: Regular maintenance and calibration to adapt to low-temperature environments and structural deformation.

[0133] Daily maintenance: Check the circuits of the first electromagnet 13 and the second electromagnet 15 of the auxiliary support components, and test the opening and closing angle range of the third arc block 14 by passing "same current" and "opposite current" respectively (to ensure that the inner tank 3 can still be accurately aligned when it shrinks by 2mm or expands by 1mm). Check the low temperature toughness of the pull rope 26 and the suspension rope 18 of the fall protection mechanism (no embrittlement cracks).

[0134] Weekly calibration: Disconnect the power supply to the magnetic levitation component, simulate the failure of the magnetic levitation part and the shrinkage / expansion of the inner tank 3, test the response time of the auxiliary support component (≤1.5 seconds), calibrate the second pressure sensor 9 (error controlled within ±2N), and verify the low-temperature elasticity of the spring 10 (it can return to its original shape after being compressed by 5mm).

[0135] Monthly in-depth maintenance: Clean impurities from the surface of the first permanent magnet 29, the third electromagnet 30, etc., check the fixing of the positioning block, and test the maximum load-bearing capacity of the anti-fall mechanism (it must exceed 1.2 times the weight of the inner tank 3 when it is full of liquid).

[0136] Step Six: Controlled Discharge and System Closure

[0137] Preparation before discharge: Adjust the magnetic levitation component through controller 16, increase the current of the third electromagnet 30 to stabilize the axial position of the inner tank 3, adjust the current of the fourth electromagnet 32 ​​and the sixth electromagnet 36, and at the same time monitor whether the inner tank 3 shrinks due to the reduction of liquid hydrogen. If necessary, pass "same current" to the first electromagnet 13 and the second electromagnet 15 to drive the third arc block 14 to move closer, so that the inner tank 3 remains horizontally coaxially suspended.

[0138] Controlled discharge: Unscrew the second plug 203 and the first plug 202 to seal the discharge pipe to the inner tube 201 and control the discharge speed (not exceeding 8L per second) to avoid a sudden drop in pressure in the inner tank 3. During the discharge process, monitor the position and deformation of the inner tank 3 every 15 seconds. If shrinkage causes the gap to increase, push the third arc block 14 to fill the gap through the "same current". If local expansion occurs, pull the third arc block 14 to avoid it through the "opposite current", or start the pull rope 26 to correct it.

[0139] Final cleaning: When the liquid hydrogen balance in inner tank 3 drops to the design lower limit (e.g., 5% of volume), stop discharging and flush the inner wall of inner tube 201 and discharge pipe 2 with nitrogen (purity ≥99.99%).

[0140] System shutdown: Gradually reduce the current of the magnetic levitation component (10% reduction every 5 seconds), while simultaneously supplying a low-intensity "opposite current" to the first electromagnet 13 and the second electromagnet 15, causing the third arc-shaped block 14 to slowly move away from the inner tank 3;

[0141] Wait for the inner tank 3 to slowly fall to the anti-fall mechanism, and read the value of the first pressure sensor 104 (it is normal if it is stable in the range of 30-80N); turn off the power of the controller 16, record the stored data (feed amount, discharge amount, number of emergency starts, electromagnet current adjustment records, etc.), and complete the equipment ledger registration.

[0142] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0143] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A liquid hydrogen storage tank, characterized in that, It includes an outer tank (1), an inner tank (3) coaxially disposed inside the outer tank (1), multiple outer rings (4) disposed on the inner wall of the outer tank (1), a first groove (5) opened on the inner wall of the outer ring (4), an inner ring (6) disposed in the first groove (5), a second groove (7) opened on the inner wall of the inner ring (6), and an auxiliary support assembly and a pressure measuring mechanism disposed in the second groove (7). The pressure measuring mechanism is used to monitor the pressure of the second arc block (12). The inner ring (6) can rotate around the center of the outer ring (4). The inner tank (3) is equipped with a feeding and discharging assembly for feeding and discharging materials; A magnetic levitation assembly for suspending the inner tank (3) is provided between the outer tank (1) and the inner tank (3); The outer tank (1) is also equipped with a fall prevention mechanism to prevent the inner tank (3) from falling. A controller (16) is fixed to the side wall of the outer tank (1). The auxiliary support assembly includes three first T-shaped blocks (8) fixed to the inner wall of the second groove (7), second arc-shaped blocks (12) fixed to both sides of the first T-shaped blocks (8), a slot one opened at the middle of one end of the second arc-shaped block (12), a first electromagnet (13) fixed to the inner wall of the slot one, and two ends respectively hinged to the second arc-shaped block (12). The third arc-shaped block (14), the second slot at the middle of one end of the third arc-shaped block (14), and the second electromagnet (15) fixed to the inner wall of the second slot. The third arc-shaped block (14) has a W-shaped structure and the inflection point of the structure is an arc transition. The concave surface of the second arc-shaped block (12) faces the center of the second slot (7). The middle part of the third arc-shaped block (14) protrudes towards the concave surface of the second arc-shaped block (12). There is a gap between the third arc-shaped block (14) and the second arc-shaped block (12) at the ends that are close to each other.

2. A liquid hydrogen storage tank according to claim 1, characterized in that, The pressure measuring mechanism includes a second pressure sensor (9) fixed to the inner wall of the second groove (7), a spring (10) fixed to the second pressure sensor (9) at one end, and a connecting block (11) fixed to the other end of the spring (10). The connecting block (11) is fixedly connected to the outer circumferential surface of the second arc-shaped block (12).

3. A liquid hydrogen storage tank according to claim 2, characterized in that, The feeding and discharging assembly includes an inner tube (201) that is fixed to the inner tank (3) at one end, a first plug (202) that is threaded to the other end of the inner tube (201), a discharge pipe (2) that is fixed to the side wall of the outer tank (1) at one end, and a second plug (203) that is threaded to the other end of the discharge pipe (2). The discharge pipe (2) and the inner tube (201) are coaxially arranged, and the inner diameter of the discharge pipe (2) is larger than the outer diameter of the inner tube (201).

4. A liquid hydrogen storage tank according to claim 3, characterized in that, The magnetic levitation assembly includes a first permanent magnet (29) fixed to both ends of the inner tank (3), a third electromagnet (30) fixed to the inner wall of the outer tank (1) corresponding to the first permanent magnet (29), two second permanent magnets (31) fixed to the side wall of the inner tank (3), two fourth electromagnets (32) fixed to the inner wall of the outer tank (1) respectively corresponding to the second permanent magnets (31), two third permanent magnets (33) fixed to the side wall of the inner tank (3), two fifth electromagnets (34) fixed to the inner wall of the outer tank (1) respectively corresponding to the third permanent magnets (33), and two fourth permanent magnets fixed to the side wall of the inner tank (3) symmetrical about the center of the inner tank (3). (35) and two sixth electromagnets (36) fixed to the inner wall of the outer tank (1) respectively corresponding to the fourth permanent magnet (35). The fourth electromagnet (32) and the sixth electromagnet (36) are symmetrical about the fifth electromagnet (34). The first permanent magnet (29), the third electromagnet (30), the second permanent magnet (31), the fourth electromagnet (32), the third permanent magnet (33), the fifth electromagnet (34), the fourth permanent magnet (35) and the sixth electromagnet (36) are fixed with positioning blocks on both sides. The two second permanent magnets (31) are symmetrical about the center of the inner tank (3), and the two third permanent magnets (33) are symmetrical about the center of the inner tank (3).

5. A liquid hydrogen storage tank according to claim 4, characterized in that, There is a gap between the first permanent magnet (29) and the third electromagnet (30), a gap between the second permanent magnet (31) and the fourth electromagnet (32), a gap between the third permanent magnet (33) and the fifth electromagnet (34), a gap between the fourth permanent magnet (35) and the sixth electromagnet (36), and at least two outer rings (4) are provided, one outer ring (4) is provided between the fifth electromagnet (34) and the sixth electromagnet (36), and the other outer ring (4) is provided between the fifth electromagnet (34) and the fourth electromagnet (32).

6. A liquid hydrogen storage tank according to claim 5, characterized in that, The anti-fall mechanism includes two supports (101) fixed to the bottom surface of the inner wall of the outer tank (1), a first arc-shaped block (102) fixed to the upper end of the support (101), a plurality of rubber cylinders (103) evenly distributed and fixed to the concave surface of the upper end of the first arc-shaped block (102), and a first pressure sensor (104) fixed to the inner wall of the rubber cylinder (103).

7. A liquid hydrogen storage tank according to claim 5, characterized in that, The anti-fall mechanism consists of two active pulling mechanisms and two passive pulling mechanisms. The active pulling mechanisms are used to lift the inner tank (3), and the passive pulling mechanisms are used to suspend the inner tank (3). The active pulling mechanism includes a fixed ring (21) fixed to the side wall of the outer tank (1), a fixed body (22) fixed to the upper end of the fixed ring (21), one end of a bent pipe (23) fixed to the upper end of the fixed body (22), a sealing box (24) fixed to the other end of the bent pipe (23), a take-up roller (25) rotatably installed on both sides of the inner wall of the sealing box (24), a servo motor (28) fixed to one side of the sealing box (24), a second through hole (27) opened through the side wall of the outer tank (1), and a fixed part of the outer tank (1). 1) The inner wall top surface is composed of a fixing block (17) and a first through hole (20) opened through the fixing block (17). The first through hole (20) and the second through hole (27) correspond to each other. One end of the pull rope (26) is fixed to the side wall of the take-up roller (25). The other end of the pull rope (26) passes through the bent pipe (23), the second through hole (27) and the first through hole (20) in sequence and extends to the inside of the outer tank (1). The other end of the pull rope (26) is fixed to a circular loop rope, which is sleeved on the side wall of the inner tank (3). The output shaft of the servo motor (28) passes through the sealing box (24) and is fixed to the rotating shaft of the take-up roller (25); The passive tension mechanism includes two fixed blocks (17) fixed to the top surface of the inner wall of the outer tank (1), a sling (18) fixed to both ends of the fixed blocks (17), and multiple limiting rings (19) fixed to the side wall of the inner tank (3). The sling (18) is sleeved on the side wall of the inner tank (3) and located between two adjacent limiting rings (19). The sling is also located between two adjacent limiting rings (19).

8. A method for storing liquid hydrogen in a storage tank, characterized in that, Using the liquid hydrogen storage tank as described in claim 7 includes the following steps: S1: System self-test and initialization: Start the controller (16) to perform functional tests on the magnetic levitation component, auxiliary support component, pressure measuring mechanism and fall protection mechanism; S2: Inner tank suspension positioning: The inner tank (3) is suspended and kept coaxial within the outer tank (1) by a magnetic levitation component; S3: Liquid hydrogen feed-out control: Liquid hydrogen is fed or discharged through the feed-out assembly, and the status of the inner tank (3) is monitored during the process; S4: Real-time monitoring and adaptive adjustment: During storage, monitor the deformation and magnetic levitation status of the inner tank (3). When the magnetic levitation is abnormal, start the auxiliary support component and adjust the gap between the auxiliary support component and the inner tank (3) according to the deformation status of the inner tank (3). S5: Emergency fall protection response: When the magnetic levitation completely fails, the fall protection mechanism is activated to support the inner tank (3). S6: System shutdown and reset: After the liquid hydrogen is discharged, gradually shut down the magnetic levitation component and make the inner tank (3) fall smoothly to the anti-fall mechanism; In step S4: When it is detected that the gap between the inner tank (3) and the auxiliary support assembly exceeds the preset threshold due to low temperature shrinkage, the first electromagnet (13) and the second electromagnet (15) in the auxiliary support assembly are controlled to pass the same current, so that the third arc block (14) moves closer to the inner tank (3) to reduce the gap. When it is detected that the pressure on the auxiliary support component exceeds the preset pressure value due to the expansion of the inner tank (3) caused by pressure fluctuation, the first electromagnet (13) and the second electromagnet (15) are controlled to pass opposite currents, so that the third arc block (14) moves away from the inner tank (3) to avoid squeezing. In step S5, the fall arrest mechanism includes an active tension mechanism and / or a passive tension mechanism, in the event of complete magnetic levitation failure: If an active pulling mechanism is used, the take-up roller (25) is driven by a servo motor (28) to tighten the pull rope (26), thereby suspending the inner tank (3); If a passive tension mechanism is used, the inner tank (3) is supported by the cooperation of the lifting rope (18) and the limiting ring (19).

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