Support structure for liquid hydrogen cylinders, front and rear support structure and liquid hydrogen cylinder

Abstract

This invention discloses a support structure, front and rear support structures, and a liquid hydrogen cylinder, relating to the technical field of liquid hydrogen cylinder support structures. The support structure includes: a first metal connector, a second metal connector, and a support body. The first metal connector is used for welding to an outer end cap; the second metal connector is used for welding to an inner end cap. The support body is made of fiberglass, and its two ends are directly or indirectly connected to the first and second metal connectors, respectively. The support body constitutes the load-bearing and heat transfer path between the first and second metal connectors, and the first and second metal connectors are only used for welding to the inner and outer end caps and connecting to the support body. This invention reduces thermal conductivity and achieves lightweight design.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen cylinder support structure technology, and in particular to a support structure, front and rear support structure, and liquid hydrogen cylinder for use in liquid hydrogen cylinders. Background Technology

[0002] Cryogenic liquid hydrogen storage involves cooling hydrogen gas to -253°C, liquefying it, and storing it in an insulated vacuum container. Compared to high-pressure gaseous hydrogen storage, liquid hydrogen storage offers advantages such as higher density and energy density, making it an important direction for on-board hydrogen storage. However, liquid hydrogen has an extremely low boiling point (-253°C), low latent heat of vaporization (0.45 kJ / g), and a large gas-liquid volume ratio (845 times). Any heat leakage will lead to rapid evaporation of the liquid hydrogen. Therefore, reducing the static evaporation rate is the core challenge for on-board liquid hydrogen storage. Simultaneously, the need for lightweight on-board gas cylinders is becoming increasingly urgent.

[0003] In the existing technology, the support structure of liquid hydrogen cylinder has the following shortcomings: (1) The main support is mostly made of metal materials (such as multi-layer metal sleeves), which have high thermal conductivity and significant thermal bridge effect; (2) Even if local fiberglass partitions are used, there are still large sections of metal in the heat transfer path, and the heat insulation effect is limited; (3) The structure is heavy, which is not conducive to lightweighting. Summary of the Invention

[0004] The purpose of this invention is to provide a support structure, front and rear support structures, and liquid hydrogen cylinder for liquid hydrogen cylinders, so as to solve the problems existing in the prior art, reduce the heat conduction effect, and achieve lightweighting.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a support structure for a liquid hydrogen cylinder, comprising: a first metal connector, a second metal connector, and a support body; the first metal connector is used for welding to an outer end cap; the second metal connector is used for welding to an inner end cap; the support body is made of fiberglass, and both ends of the support body are directly or indirectly connected to the first metal connector and the second metal connector, respectively. The supporting body forms the load-bearing path and heat transfer path between the first metal connector and the second metal connector. The first metal connector and the second metal connector are only used to realize the welding with the inner and outer end caps and the connection with the supporting body.

[0006] Preferably, at least a portion of the structure of the support body has a reciprocating and meandering shape to increase the length of the heat transfer path within a limited space.

[0007] Preferably, the support body extends along the center line of the inner end cap and the outer end cap, with one end connected to the first metal connector and the other end extending to the inner side of the inner end cap; the portion of the structure located inside the inner end cap has the reciprocating meandering shape; the second metal connector is a metal ring, which is sleeved on the support body and threadedly connected to the support body, and the outer wall of the metal ring is welded to and sealed to the inner end cap.

[0008] Preferably, the support body includes a neck tube and an extension tube, both of which extend along the center lines of the inner and outer end caps; one end of the neck tube is connected to the first metal connector, and the other end extends to the inner side of the inner end cap; the extension tube is located inside the inner end cap, the extension tube is sleeved on the outside of the neck tube and threadedly connected to the neck tube, and the extension tube has a reciprocating meandering shape.

[0009] Preferably, the portion where the neck tube is threaded to the extension tube is located at the end away from the first metal connector; the extension tube reciprocates along a direction parallel to the center line of the inner end cap; there is an annular gap between the end of the extension tube near the first metal connector and the neck tube, and a reinforcing block is sandwiched in the annular gap, the inner wall of the reinforcing block abuts against the neck tube, and the outer wall of the reinforcing block abuts against the extension tube; the second metal connector, the extension tube, and the reinforcing block are connected by a pin, and both the reinforcing block and the pin are made of fiberglass.

[0010] Preferably, the inner wall of the extension tube is provided with a first limiting surface for restricting the reinforcing block from moving axially in a first direction; the outer wall of the neck tube is provided with a second limiting surface for restricting the reinforcing block from moving axially in a second direction.

[0011] Preferably, one end of the neck tube is threadedly connected to the first metal connector.

[0012] Preferably, one end of the neck tube is slidably connected to the first metal connector along the axial direction.

[0013] The present invention also provides a front and rear support structure for a liquid hydrogen cylinder, comprising two support structures as described above; wherein, the support body in one support structure is fixedly connected to the first metal connector, and the support body in the other support structure is slidably connected to the first metal connector along the axial direction.

[0014] The present invention also provides a liquid hydrogen cylinder, including the front and rear support structures as described above.

[0015] The present invention achieves the following technical effects compared to the prior art: The supporting body 3 is entirely made of fiberglass, while the first and second metal connectors are only used for welding to the inner and outer end caps 5 and for connecting to the supporting body 3. Since the thermal conductivity of fiberglass (approximately 0.3 W / (m·K)) is only 1 / 50 that of stainless steel (approximately 15 W / (m·K)), and the supporting body 3 occupies the majority of the heat transfer path, heat transfer from the outer end cap 5 to the inner end cap 6 must occur along the fiberglass body. Compared to existing technologies where the metal sleeve is the main component and fiberglass is only used for partial partitioning, this embodiment fundamentally eliminates metal thermal bridges, significantly reducing the static evaporation rate. Simultaneously, the density of fiberglass is approximately 1 / 4 that of stainless steel, greatly reducing the weight of the supporting structure and meeting the lightweight requirements for vehicle applications. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A cross-sectional view of a support structure for a liquid hydrogen cylinder provided in an embodiment of the present invention; Figure 2 for Figure 1 A magnified view of a section at point A in the middle; Figure 3 for Figure 1 Exploded view; Figure 4 for Figure 1 Schematic diagram of the middle extension tube; Figure 5 for Figure 4 A sectional view; Figure 6 A cross-sectional view of a support structure for a liquid hydrogen cylinder provided in another embodiment of the present invention; In the figure: 1-First metal connector; 2-Second metal connector; 31-Neck tube; 32-Extension tube; 3-Support body; 4-Reinforcing block; 5-Outer end cap; 6-Inner end cap; 7-Pin; 8-Shaft sleeve. Detailed Implementation

[0018] 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.

[0019] The purpose of this invention is to provide a support structure, front and rear support structures, and liquid hydrogen cylinder for liquid hydrogen cylinders, so as to solve the problems existing in the prior art, reduce the heat conduction effect, and achieve lightweighting.

[0020] This invention provides a novel liquid hydrogen cylinder support structure, which uses an all-fiberglass body as the main load-bearing component and uses only a small amount of stainless steel at necessary welding connection points. It is assembled by threaded connection and fixed with fiberglass pins. While ensuring the support strength, it significantly reduces the structural weight, completely blocks the thermal bridge effect, and simplifies the manufacturing process.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The following is combined Figures 1 to 6 The following describes embodiments of the present invention.

[0023] Example 1 The present invention provides a support structure for a liquid hydrogen cylinder, comprising: a first metal connector 1, a second metal connector 2, and a support body 3; the first metal connector 1 is used for welding connection with an outer end cap 5; the second metal connector 2 is used for welding connection with an inner end cap 6; the support body 3 is made of fiberglass material, and both ends of the support body 3 are directly or indirectly connected to the first metal connector 1 and the second metal connector 2, respectively. The supporting body 3 forms the load-bearing path and heat transfer path between the first metal connector 1 and the second metal connector 2. The first metal connector 1 and the second metal connector 2 are only used to achieve welding with the inner and outer end caps 5 and connection with the supporting body 3.

[0024] The supporting body 3 is entirely made of fiberglass, while the first and second metal connectors are only used for welding to the inner and outer end caps 5 and for connecting to the supporting body 3. Since the thermal conductivity of fiberglass (approximately 0.3 W / (m·K)) is only 1 / 50 that of stainless steel (approximately 15 W / (m·K)), and the supporting body 3 occupies the majority of the heat transfer path, heat transfer from the outer end cap 5 to the inner end cap 6 must occur along the fiberglass body. Compared to existing technologies where the metal sleeve is the main component and fiberglass is only used for partial partitioning, this embodiment fundamentally eliminates metal thermal bridges, significantly reducing the static evaporation rate. Simultaneously, the density of fiberglass is approximately 1 / 4 that of stainless steel, greatly reducing the weight of the supporting structure and meeting the lightweight requirements for vehicle applications.

[0025] In some examples, the sum of the volumes of the first metal connector 1 and the second metal connector 2 is less than half the volume of the supporting body 3. For example, it can be less than 1 / 4, 1 / 5, 1 / 6, etc.

[0026] In some embodiments, at least a portion of the structure of the support body 3 is in a reciprocating and meandering shape to increase the length of the heat transfer path within a limited space.

[0027] In this embodiment, at least a portion of the supporting body 3 has a reciprocating tortuous shape. The length of the heat transfer path is inversely proportional to the amount of heat conduction. Within the limited space of the gas cylinder interlayer, by designing the supporting body 3 in a reciprocating tortuous shape, the actual heat transfer length is significantly extended, thereby further reducing the heat flow rate with the same material. At the same time, the reciprocating tortuous structure increases the contact area between the fiberglass and the surrounding vacuum space, which is beneficial for radiative heat dissipation to be absorbed by the outer tank, reducing the heat entering the inner tank. This structure does not require additional materials; simply changing the geometry improves the thermal insulation performance.

[0028] Alternatively, the reciprocating and meandering shape can be wavy, sawtooth, or labyrinthine. Furthermore, the meandering portion is not limited to the axial direction; it can also form a spiral structure in the radial plane, as long as it increases the total heat transfer distance within a limited space.

[0029] In some embodiments, the support body 3 extends along the center line of the inner end cap 6 and the outer end cap 5, with one end connected to the first metal connector 1 and the other end extending to the inner side of the inner end cap 6; the part of the structure located inside the inner end cap 6 has a reciprocating and meandering shape; the second metal connector 2 is a metal ring, which is sleeved on the outside of the support body 3 and threadedly connected to the support body 3, and the outer wall of the metal ring is welded to and sealed to the inner end cap 6.

[0030] The supporting body 3 extends along the centerline and enters the inner end cap 6, with its inner portion exhibiting a reciprocating, meandering shape. The second metal connector 2 is a metal ring, fitted around the supporting body 3 and threadedly connected, with the outer wall of the metal ring welded and sealed to the inner end cap 6. This design, by placing the reciprocating, meandering structure inside the inner end cap 6 (i.e., inside the inner tank), significantly increases the length of the structure compared to placing the meandering structure within the vacuum interlayer between the inner and outer end caps 5, thereby enhancing the insulation effect.

[0031] In some embodiments, the support body 3 includes a neck tube 31 and an extension tube 32, both of which extend along the center line of the inner end cap 6 and the outer end cap 5; one end of the neck tube 31 is connected to the first metal connector 1, and the other end extends to the inner side of the inner end cap 6; the extension tube 32 is located inside the inner end cap 6, the extension tube 32 is sleeved on the outside of the neck tube 31 and threadedly connected to the neck tube 31, and the extension tube 32 has a reciprocating meandering shape.

[0032] This embodiment specifically defines the support body 3 as consisting of a neck tube 31 and an extension tube 32, both extending along a centerline. The extension tube 32 is fitted over the neck tube 31 and threadedly connected, and has a reciprocating, meandering shape. This inner and outer tube structure creates an annular gap between the neck tube 31 and the extension tube 32, which can be evacuated or filled with insulating material. When heat is transferred from the neck tube 31, it must first be transferred from the wall of the neck tube 31 to the gap, and then to the wall of the extension tube 32. The existence of the gap significantly reduces direct contact heat transfer. At the same time, the reciprocating, meandering shape of the extension tube 32 further extends the heat conduction distance along the wall of the extension tube 32. The threaded connection ensures the stability of the axial relative position of the neck tube 31 and the extension tube 32, and the length tolerance can be adjusted by rotation during assembly.

[0033] In some examples, the number of neck tubes 31 and extension tubes 32 can be more than two, for example, three or four nested layers are provided, with each layer connected by threads, the innermost layer connected to the first metal connector 1, and the outermost layer connected to the second metal connector 2.

[0034] In some embodiments, the threaded connection between the neck tube 31 and the extension tube 32 is located at the end away from the first metal connector 1; the extension tube 32 reciprocates along a direction parallel to the center line of the inner end cap 6; there is an annular gap between the end of the extension tube 32 near the first metal connector 1 and the neck tube 31, and a reinforcing block 4 is sandwiched in the annular gap, the inner wall of the reinforcing block 4 abuts against the neck tube 31, and the outer wall of the reinforcing block 4 abuts against the extension tube 32; the second metal connector 2, the extension tube 32 and the reinforcing block 4 are connected by a pin 7, and both the reinforcing block 4 and the pin 7 are made of fiberglass.

[0035] In this embodiment, the threaded connection between the neck tube 31 and the extension tube 32 is located at the end furthest from the first metal connector 1. An annular gap is formed between the end of the extension tube 32 closest to the first metal connector 1 and the neck tube 31, with a fiberglass reinforcing block 4 sandwiched within the gap. The second metal connector 2, the extension tube 32, and the reinforcing block 4 are connected by a fiberglass pin 7. The reinforcing block 4 serves to withstand radial and axial loads, preventing the extension tube 32 from swaying or becoming eccentric relative to the neck tube 31. Simultaneously, the reinforcing block 4 itself is made of fiberglass, resulting in extremely low heat transfer efficiency. The pin 7 mechanically locks all three together, preventing loosening of the threads or detachment of the reinforcing block 4 under vibration conditions. This structure significantly improves the vibration resistance and overall rigidity of the support structure while ensuring thermal insulation performance, making it particularly suitable for vehicle transportation environments.

[0036] Multiple reinforcing blocks 4 can be provided, distributed axially or arranged in circumferential segments. The pin 7 can also be a tapered pin or a flexible pin to eliminate assembly clearance. In addition, the contact surfaces between the reinforcing block 4 and the neck tube 31 and the extension tube 32 can be provided with a convex-concave fitting positioning structure (such as a keyway) to prevent relative rotation.

[0037] In some embodiments, the inner wall of the extension tube 32 is provided with a first limiting surface for restricting the reinforcing block 4 from moving axially in a first direction; the outer wall of the neck tube 31 is provided with a second limiting surface for restricting the reinforcing block 4 from moving axially in a second direction.

[0038] In this embodiment, a first limiting surface is provided on the inner wall of the extension tube 32 to restrict the movement of the reinforcing block 4 in a first direction; a second limiting surface is provided on the outer wall of the neck tube 31 to restrict the movement of the reinforcing block 4 in a second direction. The two limiting surfaces in opposite directions together clamp the reinforcing block 4 at a predetermined axial position. When the gas cylinder experiences acceleration, deceleration, or vibration during transportation, the reinforcing block 4 may be subjected to axial inertial force. Without the limiting surfaces, the reinforcing block 4 may slide axially, leading to a decrease in support stiffness or even structural failure. The first and second limiting surfaces bear axial loads in different directions, ensuring that the reinforcing block 4 is always located in an effective load-bearing position within the annular gap. This structure is simple and reliable, achieving bidirectional positioning without the need for additional fasteners.

[0039] The limiting surface can be a continuous annular step or multiple discrete protrusions or blocks. The limiting surface can also be located at both ends of the reinforcing block 4, respectively engaging with the steps on the neck tube 31 and the extension tube 32. Furthermore, elastic washers or buffer layers can be installed at the limiting surface to absorb impact energy and reduce damage to the fiberglass material from hard contact.

[0040] In some embodiments, such as Figure 1 As shown, one end of the neck tube 31 is threadedly connected to the first metal connector 1.

[0041] In this embodiment, one end of the neck tube 31 is threadedly connected to the first metal connector 1. The threaded connection is self-locking, capable of withstanding axial tensile force without loosening, while allowing a certain degree of axial adjustment, facilitating alignment with the welding positions of the inner and outer end caps 5 during assembly. Furthermore, the threaded connection is detachable, allowing the neck tube 31 to be easily separated from the first metal connector 1 when the support structure needs maintenance or replacement, thus reducing maintenance costs.

[0042] The threaded connection between the neck tube 31 and the first metal connector 1 can adopt a double nut anti-loosening structure, or apply low-temperature anti-loosening adhesive to the threads.

[0043] In some embodiments, such as Figure 6 As shown, one end of the neck tube 31 is slidably connected to the first metal connector 1 along the axial direction.

[0044] In this embodiment, one end of the neck tube 31 is slidably connected to the first metal connector 1 along the axial direction. When the liquid hydrogen cylinder is filled with liquid hydrogen, the temperature of the inner tank drops from room temperature (approximately 20°C) to -253°C, resulting in significant axial contraction (for a 10m long storage tank, the contraction can reach several millimeters to tens of millimeters). If both ends of the support are fixed connections, the contraction of the inner tank will generate huge internal stress, which may lead to damage to the support structure or the end cap. In this embodiment, by setting one end to a slidable connection, the inner tank is allowed to move freely axially during contraction, thereby releasing thermal stress. At the same time, the sliding connection can still transmit radial force and bending moment, ensuring the positioning accuracy of the inner tank.

[0045] Alternatively, a sliding connection can employ a bushing 8 and linear bearings, a key, or a dovetail groove structure. To ensure smooth sliding and prevent excessive frictional heat, the sliding interface can be coated with a low-friction coating (such as PTFE) or a ball / roller cage can be used. Furthermore, the axial travel of the sliding connection should exceed the maximum amount of thermal contraction, and a limiting device should be provided to prevent disengagement.

[0046] Example 2 The present invention also provides a front and rear support structure for a liquid hydrogen cylinder, comprising two support structures as described in Embodiment 1 above; wherein, the support body 3 in one support structure is fixedly connected to the first metal connector 1, as shown in the figure. Figure 1 As shown, in another support structure, the support body 3 is slidably connected to the first metal connector 1 along the axial direction, as... Figure 6 As shown.

[0047] This embodiment combines two support structures into a front and rear support structure, with one end fixed and the other sliding. The fixed connection of the front support body 3 ensures the axial reference position of the inner tank within the outer tank; the sliding connection at the rear allows the inner tank to expand and contract freely with temperature changes. This "fixed at one end, sliding at the other" support layout is a classic way to withstand thermal deformation and effectively avoids over-constraint of the structure due to temperature differences. Both support structures use fiberglass bodies, resulting in a significantly lower overall weight compared to all-metal support solutions. During actual liquid hydrogen filling, the inner tank contracts, and the neck tube 31 of the rear support slides backward in the first metal connector 1 without generating additional stress; while the front support maintains its positioning accuracy. This structure combines excellent thermal insulation performance with thermal stress release capabilities.

[0048] Example 3 The present invention also provides a liquid hydrogen cylinder, including the front and rear support structures as described in Embodiment 2 above.

[0049] This embodiment provides a liquid hydrogen cylinder incorporating the aforementioned front and rear support structures. During use, the inner tank is installed inside the outer tank via the front and rear support structures, and a vacuum is created between the inner and outer tanks. Upon injection of liquid hydrogen, the inner tank experiences a rapid temperature drop and axial contraction, with the rear sliding support automatically compensating for the displacement and preventing structural damage. Because the support body 3 is made of fiberglass and has a reciprocating, meandering structure, external heat is extremely difficult to transfer to the inner tank, significantly reducing the static evaporation rate of liquid hydrogen. Simultaneously, the entire support system is lightweight, contributing to improved range of the vehicle-mounted cylinder. Compared to existing technologies, this cylinder exhibits significant improvements in thermal insulation, weight reduction, and thermal stress adaptability.

[0050] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A support structure for a liquid hydrogen cylinder, characterized in that, include: The first metal connector is used for welding connection with the outer end cap; The second metal connector is used for welding connection with the inner head; The supporting body is made of fiberglass material, and its two ends are directly or indirectly connected to the first metal connector and the second metal connector, respectively. The supporting body forms the load-bearing path and heat transfer path between the first metal connector and the second metal connector. The first metal connector and the second metal connector are only used to realize the welding with the inner and outer end caps and the connection with the supporting body.

2. The support structure according to claim 1, characterized in that: At least a portion of the supporting structure has a reciprocating and meandering shape to increase the length of the heat transfer path within a limited space.

3. The support structure according to claim 2, characterized in that: The support body extends along the center line of the inner and outer end caps, with one end connected to the first metal connector and the other end extending to the inner side of the inner end cap; the part of the structure located inside the inner end cap has the reciprocating and meandering shape; the second metal connector is a metal ring, which is sleeved on the outside of the support body and threadedly connected to the support body, and the outer wall of the metal ring is welded to and sealed to the inner end cap.

4. The support structure according to claim 1, characterized in that: The supporting body includes a neck tube and an extension tube, both of which extend along the center lines of the inner and outer end caps. One end of the neck tube is connected to the first metal connector, and the other end extends to the inner side of the inner end cap. The extension tube is located inside the inner end cap, is sleeved on the outside of the neck tube and threadedly connected to the neck tube, and the extension tube has a reciprocating meandering shape.

5. The support structure according to claim 4, characterized in that: The portion where the neck tube is threaded to the extension tube is located at the end away from the first metal connector; the extension tube reciprocates along a direction parallel to the center line of the inner end cap; there is an annular gap between the end of the extension tube near the first metal connector and the neck tube, and a reinforcing block is sandwiched in the annular gap, the inner wall of the reinforcing block abuts against the neck tube, and the outer wall of the reinforcing block abuts against the extension tube; the second metal connector, the extension tube, and the reinforcing block are connected by a pin, and both the reinforcing block and the pin are made of fiberglass.

6. The support structure according to claim 5, characterized in that: The inner wall of the extension tube is provided with a first limiting surface for restricting the reinforcing block from moving axially in a first direction; the outer wall of the neck tube is provided with a second limiting surface for restricting the reinforcing block from moving axially in a second direction.

7. The support structure according to claim 4, characterized in that: One end of the neck tube is threadedly connected to the first metal connector.

8. The support structure according to claim 4, characterized in that: One end of the neck tube is slidably connected to the first metal connector along the axial direction.

9. A front and rear support structure for a liquid hydrogen cylinder, characterized in that: It includes two support structures as described in any one of claims 1 to 6; wherein, the support body in one support structure is fixedly connected to the first metal connector, and the support body in the other support structure is slidably connected to the first metal connector along the axial direction.

10. A liquid hydrogen cylinder, characterized in that: Includes the front and rear support structures as described in claim 9.

Images