Underwater hydrogen storage system

Abstract

The invention provides an underwater hydrogen storage system. The underwater hydrogen storage system comprises a water surface floating platform arranged on the water surface, a hydrogen storage container arranged in the water and a position adjusting and damage protection unit arranged in the water. The water surface floating platform is connected with the hydrogen storage container; the position adjustment and damage protection unit comprises a first cable, a second cable, a first balancing weight, a first pulley block, a second pulley block and a protection unit covering the outer side of the hydrogen storage container; the first pulley block is movably connected to the water surface floating platform; one end of the first cable is connected with the first pulley block, and the other end of the first cable is connected with the first balancing weight; the second pulley block is movably connected to the first balancing weight; one end of the second cable is connected with the first pulley block, and the other end of the second cable is connected with the protection unit through the second pulley block. The structure can greatly improve the hydrogen storage capacity, and is easy to implement, high in assembly efficiency, low in installation cost and suitable for large-scale application.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage and transportation, and in particular to an underwater hydrogen storage system. Background Art

[0002] As a secondary energy source, hydrogen boasts clean, low-carbon properties, long-term storage, and flexibility and efficiency. Compared to other energy storage methods, hydrogen storage can leverage its energy properties to participate in power system regulation as a storage medium, and can also leverage its raw material properties to generate product revenue in the industrial sector. Therefore, it is gaining increasing attention. Using renewable energy to generate hydrogen effectively improves renewable energy consumption. Hydrogen storage, with its large capacity, long lifespan, and zero pollution, is more competitive in long-term, cross-seasonal energy storage scenarios. However, the storage and transportation of hydrogen have always been key issues hindering its large-scale application.

[0003] Currently, the primary method for storing hydrogen is through ground-based high-pressure gaseous hydrogen storage. The storage density of hydrogen is significantly affected by the storage pressure, which in turn is limited by the tank material. Furthermore, the storage scale is limited by the land available. Consequently, this method is costly and small-scale. Furthermore, hydrogen leaks are difficult to detect, and leaked hydrogen quickly comes into contact with oxygen in the air, making it highly susceptible to explosions when exposed to open flames. This poses significant safety risks and hinders the development of the hydrogen energy industry.

[0004] Some also liquefy hydrogen and transport it via tanker trucks. However, this requires cooling the hydrogen to its boiling point of -253°C. This technology is complex and requires significant investment in liquefaction plants. The energy consumed by hydrogen liquefaction accounts for over 30% of the energy content of the hydrogen itself, which significantly reduces its economic viability. Long-term storage of liquid hydrogen also presents significant challenges, requiring cryogenic tanks and strict insulation. Furthermore, the evaporation of liquid hydrogen can lead to pressure buildup, requiring pressure relief devices to mitigate safety risks.

[0005] The technology maturity of solid-state and liquid hydrogen storage based on materials is low, and industrial development has not been achieved. There are also problems with efficiency loss due to too many conversion links. Summary of the Invention

[0006] Based on this, an embodiment of the present invention provides an underwater hydrogen storage system, which aims to solve the problems of existing hydrogen storage methods such as high cost, small storage scale, harsh storage conditions, high safety risks and difficulty in industrial development.

[0007] To achieve the above objectives, an embodiment of the present invention provides an underwater hydrogen storage system, comprising a surface floating platform disposed on the water surface, a hydrogen storage container disposed in the water, and a position adjustment and damage protection unit disposed in the water; the surface floating platform is connected to the hydrogen storage container;

[0008] The position adjustment and damage protection unit includes a first cable, a second cable, a first counterweight, a first pulley block, a second pulley block, and a protection unit covering the outside of the hydrogen storage container;

[0009] The first pulley group is movably connected to the water floating platform; one end of the first cable is connected to the first pulley group, and the other end is connected to the first counterweight block; the second pulley group is movably connected to the first counterweight block; one end of the second cable is connected to the first pulley group, and the other end is connected to the protection unit through the second pulley group.

[0010] As a preferred embodiment, the first pulley group is movably connected to the edge of the water floating platform; the second pulley group is movably connected to the edge of the first counterweight block; and the second cable between the second pulley group and the protection unit is provided with a margin.

[0011] As a preferred embodiment, the position adjustment and damage protection unit further includes a third cable, a fourth cable, a second counterweight, a third pulley set, and a fourth pulley set;

[0012] The third pulley group is movably connected to the water floating platform; one end of the third cable is connected to the third pulley group, and the other end is connected to the second counterweight block; the fourth pulley group is movably connected to the second counterweight block; one end of the fourth cable is connected to the third pulley group, and the other end is connected to the protection unit through the fourth pulley group.

[0013] As a preferred embodiment, the third pulley group is movably connected to the edge of the water floating platform; the fourth pulley group is movably connected to the edge of the second counterweight block; the fourth cable between the fourth pulley group and the protection unit is provided with a margin; one end of the protection unit is connected to the second cable, and the other end is connected to the fourth cable.

[0014] As a preferred embodiment, the protection unit is a mesh composed of a cable net, or a shell composed of a film, rubber, plastic or composite metal material.

[0015] As a preferred embodiment, the hydrogen storage container includes two flanges and an inflatable bladder, and the two flanges are respectively arranged at the two ends of the inflatable bladder; the inflatable bladder is composed of several pieces of skin flaps; a reinforcing rib is provided at the joint of two adjacent pieces of skin flaps, and one end of the reinforcing rib is connected to the flange; the protective unit is sleeved on the outside of the inflatable bladder.

[0016] As a preferred embodiment, the splicing is achieved by sewing, welding and applying a barrier coating; along the splicing direction, the length of the skin radial flap is greater than the length of the reinforcement rib; the length of the reinforcement rib is equal to the length of the splicing seam.

[0017] As a preferred embodiment, the reinforcing ribs are rigid bars or flexible ropes; a cable net is provided on the outer side of the middle portion of the inflatable bladder; and the cable net is slidable relative to the inflatable bladder.

[0018] As a preferred embodiment, a plurality of positioning holes are provided on the flange; the reinforcing ribs and the cable net are connected to the flange through the positioning holes.

[0019] As a preferred embodiment, an annular opening is provided at the center of the flange, a connecting pipe communicating with the inflatable bag is provided at the center of the annular opening; and a valve for controlling the connecting pipe is provided on the connecting pipe.

[0020] As a preferred embodiment, the flange is further provided with a sensor for monitoring the environmental parameters of the inflatable bladder; the environmental parameters include bladder pressure, water depth, water flow velocity, water flow direction or temperature.

[0021] As a preferred embodiment, the surface floating platform is provided with a system control unit, which is connected to the sensor. The control unit calculates the position and posture of the hydrogen storage container based on the parameters returned by the sensor, and adjusts the position and posture of the hydrogen storage container through the position adjustment and damage protection unit.

[0022] As a preferred embodiment, the underwater hydrogen storage system also includes a hydrogen production electrolyzer arranged on a land or water floating platform, the hydrogen production electrolyzer is connected to the water floating platform through a first hydrogen transmission pipeline, and the end of the first hydrogen transmission pipeline close to the water floating platform is connected to the hydrogen storage container through a second hydrogen transmission pipeline; the water floating platform is connected to the land or water floating platform through a connecting line.

[0023] Compared with the existing technology, the structure of this application has the following technical effects:

[0024] (1) The present application adopts a flexible inflatable structure to solve the manufacturing and transportation problems of large-volume hydrogen storage containers. The volume of the inflatable bladder can be easily manufactured from a few cubic meters to thousands or even tens of thousands of cubic meters. Before hydrogen filling, the hydrogen storage container can be folded into a very small volume for easy transportation. The hydrogen storage container is inflated and unfolded for easy deployment.

[0025] (2) The hydrogen storage container adopts an overpressure structure design, which can realize medium and low pressure hydrogen storage in large-volume containers. Through position adjustment and damage protection units, the underwater water pressure can be used to adjust the water depth of the hydrogen storage container, reduce the internal and external pressure difference of the bladder, and further increase the actual internal pressure of the hydrogen storage container, thereby significantly improving the hydrogen storage capacity.

[0026] (3) Storing hydrogen in an inflatable bladder underwater avoids the problem of lack of space on land. Underwater hydrogen storage is safer and even if a leak occurs, it is easy to observe and will not cause major damage.

[0027] (4) The hydrogen storage system is easy to standardize, making it convenient to store a large number of hydrogen storage containers in a certain sea area through arrays, which can achieve a large-scale hydrogen storage effect similar to salt caverns. Moreover, hydrogen is stored in a medium- and low-pressure gas state, eliminating the need for conversion and high-pressure compression, reducing energy loss.

[0028] (5) The present application has a simple structure, is easy to implement, has high assembly efficiency and low installation cost, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] Figure 1 Schematic diagram of the structure of an underwater hydrogen storage system according to one embodiment of the present invention;

[0031] Figure 2 for Figure 1 Schematic diagram of the front structure of the hydrogen storage container.

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom...), then the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0035] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] Specifically, such as Figure 1 As shown, an embodiment of the present application provides an underwater hydrogen storage system, comprising a surface floating platform 10 disposed on the water surface, a hydrogen storage container 20 disposed in the water, and a position adjustment and damage protection unit 30 disposed in the water; the surface floating platform 10 is connected to the hydrogen storage container 20;

[0039] The position adjustment and damage protection unit 30 includes a first cable 31, a second cable 32, a first counterweight 33, a first pulley set 34, a second pulley set 35, and a protection unit (not marked in the figure) covering the outside of the hydrogen storage container 20;

[0040] The first pulley group 34 is movably connected to the water surface floating platform 10; one end of the first cable 31 is connected to the first pulley group 34, and the other end is connected to the first counterweight block 33; the second pulley group 35 is movably connected to the first counterweight block 33; one end of the second cable 32 is connected to the first pulley group 34, and the other end is connected to the protection unit through the second pulley group 35.

[0041] In the embodiment of the present application, the anchoring of the surface floating platform refers to the existing offshore surface platform technology, and the surface fixed / floating platform can also be modified and utilized.

[0042] Due to the position adjustment and damage protection unit, the hydrogen storage container is always suspended in a certain underwater area at a set depth, and the depth of the hydrogen storage container can be adjusted accordingly by the counterweight block.

[0043] As a preferred embodiment, the first pulley group 34 is movably connected to the edge of the water surface floating platform 10; the second pulley group 35 is movably connected to the edge of the first counterweight block 34; and the second cable 32 between the second pulley group 35 and the protection unit is provided with a margin.

[0044] The first cable primarily adjusts the depth of the first counterweight in the water. The second cable between the second pulley block and the protection unit is designed with a margin, allowing the hydrogen storage container to move within a certain area in the water. If the hydrogen storage container drifts outside this area, the container's position in the water is adjusted by moving the second pulley block and adjusting the length of the second cable. To adjust the water depth of the hydrogen storage container, the length of the first cable is adjusted using the first pulley block, allowing the first counterweight to raise or lower the hydrogen storage container, thereby adjusting its depth in the water.

[0045] The power cord and hydrogen hose of this application can be retracted and extended in a similar manner to the above-mentioned cables, but the power cord and hydrogen hose do not bear the load. The interfaces of each system of this application are strictly sealed and anti-corrosion measures are adopted to prevent moisture, salt, etc. from corroding the structure.

[0046] As a preferred embodiment, the position adjustment and damage protection unit 30 further includes a third cable (not labeled in the figure), a fourth cable (not labeled in the figure), a second counterweight (not labeled in the figure), a third pulley set (not labeled in the figure), and a fourth pulley set (not labeled in the figure);

[0047] The third pulley group is movably connected to the water surface floating platform 10; one end of the third cable is connected to the third pulley group, and the other end is connected to the second counterweight block; the fourth pulley group is movably connected to the second counterweight block; one end of the fourth cable is connected to the third pulley group, and the other end is connected to the protection unit through the fourth pulley group.

[0048] As a preferred embodiment, the third pulley group is movably connected to the edge of the water surface floating platform 10; the fourth pulley group is movably connected to the edge of the second counterweight block; the fourth cable between the fourth pulley group and the protection unit is provided with a margin; one end of the protection unit is connected to the second cable, and the other end is connected to the fourth cable.

[0049] In an embodiment of the present application, the third cable is symmetrically arranged with the first cable, the fourth cable is symmetrically arranged with the second cable, the second counterweight is symmetrically arranged with the first counterweight, the third pulley group is symmetrically arranged with the first pulley group, and the fourth pulley group is symmetrically arranged with the second pulley group. This can better ensure that the hydrogen storage container is effectively confined to a certain water depth, and can be confined to a certain area and maintain the optimal posture (such as minimum resistance).

[0050] As a preferred embodiment, the protection unit is a mesh made of a cable net, or a shell made of a film, rubber, plastic, or composite metal material. The protection unit has a certain corrosion resistance and strength, and effectively protects the hydrogen storage container.

[0051] As a preferred embodiment, Figure 2 As shown, the hydrogen storage container 20 includes two flanges 21 and an inflatable bladder 22, and the two flanges 21 are respectively arranged at the two ends of the inflatable bladder 22; the inflatable bladder 22 is spliced by a number of skin flaps 221; reinforcing ribs 40 are provided at the joints of two adjacent skin flaps 221, and the two ends of the reinforcing ribs 40 are connected to the flanges 21, and the reinforcing ribs are connected to the seams and retain the degree of freedom along the warp direction; the protective unit is sleeved on the outside of the inflatable bladder 22.

[0052] The skin flaps 221 act as a hydrogen barrier and withstand pressure. Their specific parameters are determined based on the actual pressure-bearing capacity, weather resistance requirements, and processability. By combining multiple layers of materials with different properties (e.g., a thermoplastic polyurethane coating as the outermost anti-aging layer, a load-bearing fabric layer of Kevlar fiber as the middle layer, and a polyethylene film and polyvinyl alcohol coating as the inner high-barrier layer), they achieve varying load-bearing and gas (and / or water) barrier properties. The thickness of the skin flaps is generally millimeters or less.

[0053] Several skin flaps 221 are spliced together to form a first hemispherical portion at one end, a cylindrical portion in the middle, and a second hemispherical portion at the other end. The radius of the first hemispherical portion, the radius of the cylindrical portion, and the radius of the second hemispherical portion are all the same. In this way, the shape of the inflatable bladder is a combination of a hemispherical portion and a cylindrical portion, allowing the structure of the present application to withstand high internal pressure while increasing the volume of gas stored by increasing the length of the cylindrical portion, thereby storing more gas. The stress in the meridian direction of the bladder is borne by the reinforcing ribs, and the circumferential stress is borne by the skin flaps. The local circumferential bulge formed by the skin flaps after overpressure effectively reduces the radius of curvature of the skin flaps after inflation, thereby effectively reducing the stress level in the circumferential direction of the cylindrical portion. By adjusting the length, radius, and internal pressure of the cylindrical portion, the hydrogen storage density of a given material can be greatly increased. The structure of the present application is characterized by being lightweight, deployable, large-capacity, and low-cost. The number of reinforcing ribs and skin flaps can be set according to actual usage needs (based on mechanical design and processing performance).

[0054] As a preferred embodiment, the splicing is achieved by sewing, welding and applying a barrier coating; along the direction of the splicing, the length of the skin radial flap 221 is greater than the length of the reinforcing rib 40; the length of the reinforcing rib 40 is equal to the length of the seam of the splicing. Specifically, in this embodiment, the splicing is achieved by sewing and welding, and the reinforcing ribs are connected to the seam and retain the degree of freedom along the warp direction. With this arrangement, when the inflatable bladder is inflated, the force in the warp direction is entirely borne by the reinforcing ribs; the skin radial flaps only bear circumferential stress, and the skin radial flaps are compressed and bulged between the reinforcing ribs to form a bulge (the radius r of the bulge is smaller than the radius R of the first hemisphere, so a flexible material with lower strength can withstand the circumferential stress). Compared with a traditional sphere, the radius of curvature of the structure of the present application will be significantly reduced, and the same material can be used to withstand a greater pressure difference.

[0055] In a preferred embodiment, the reinforcing ribs 40 are rigid bars or flexible ropes. A cable net 50 is disposed outside the central portion of the inflatable bladder 22; the cable net 50 is slidable relative to the inflatable bladder 22. The specific parameters and shape of the reinforcing ribs are determined based on actual usage requirements. The rigid bars can be made of aluminum or carbon fiber reinforced composite materials, while the flexible ropes can be carbon fiber or other high-strength flexible cables. The cable net's restraint ensures the cylindrical portion maintains its cylindrical shape and, in conjunction with the reinforcing ribs, effectively reduces the radius of curvature of the skin lobes.

[0056] As a preferred embodiment, the flange 21 is provided with a plurality of positioning holes (not marked in the figure); the reinforcing ribs 40 and the cable net 50 are connected to the flange 21 through the positioning holes. Generally, the flange is provided with a positioning docking device, through which the reinforcing ribs and the cable net can be fixed to the flange.

[0057] As a preferred embodiment, each flange 21 is provided with an annular opening (not marked in the figure) at its center, and a connecting pipe 23 is provided at the center of the annular opening, which is in communication with the inflatable bladder 22. A valve 24 is provided on the connecting pipe 23 to control the connecting pipe 23. This allows for initial emptying and pressure relief in special circumstances.

[0058] As a preferred embodiment, the flange 21 is also provided with a sensor (not marked in the figure) for monitoring the environmental parameters of the inflatable bladder 22; the environmental parameters include bladder pressure, water depth, water flow velocity, water flow direction or temperature, etc.

[0059] As a preferred embodiment, the surface floating platform 10 is provided with a system control unit 11, which is connected to the sensor. The sensor is powered by a cable and transmits data back to the system control unit. The system control unit uses the data returned by the sensor to monitor the pressure, position, posture, and depth of the inflatable bladder. The system control unit also adjusts the water depth and optimal posture (e.g., minimizes resistance) of the hydrogen storage container through position adjustment and the cable of the damage protection unit.

[0060] As a preferred embodiment, Figure 2 As shown, the underwater hydrogen storage system also includes a hydrogen production electrolyzer 60 arranged on a land or water floating platform, and the hydrogen production electrolyzer 60 is connected to the surface floating platform 10 through a first hydrogen transmission pipeline 61. The end of the first hydrogen transmission pipeline 61 close to the surface floating platform 10 is connected to the hydrogen storage container 20 through a second hydrogen transmission pipeline 62; the surface floating platform 10 is connected to the land or water floating platform through a connecting line 12.

[0061] As a preferred embodiment, when the electricity generated by the new energy power system cannot be absorbed by the power grid, the electricity is converted into hydrogen through a hydrogen production electrolyzer and stored in the underwater hydrogen storage system; when the power grid is insufficient, the hydrogen can be released to generate electricity through the fuel cell generator 70 to provide electricity.

[0062] Or when the new energy power system is an off-grid power generation system, electricity can be converted into hydrogen through a hydrogen production electrolyzer and stored in the underwater hydrogen storage system. The stored hydrogen will then be utilized or transported in an appropriate manner.

[0063] As a preferred embodiment, a certain number of such hydrogen storage systems can be arranged in a water area according to certain rules or arrays, and their hydrogen transmission pipelines can be configured as trunk and branch lines to achieve large-scale hydrogen storage.

[0064] In the embodiment of the present application, the main functions achieved by the position adjustment and damage protection unit are: maintaining the hydrogen storage container floating at a certain water depth and being able to adjust the water depth of the hydrogen storage container; ensuring that the hydrogen storage container is within a certain range at the bottom of the water and is not washed away by the water flow; and preventing the hydrogen storage container structure from being damaged by the marine environment.

[0065] The volume and weight of the position adjustment and damage protection unit are determined based on the volume of the hydrogen storage container and the working depth range, ensuring that after the position adjustment and damage protection unit is installed and docked with the hydrogen storage container, the volume density of the underwater part (hydrogen storage container + position adjustment and damage protection unit) is approximately equal to the water density at the water depth in which it is located, so that the underwater part can be in a suspended state at this depth.

[0066] The floating platform on the water surface can be installed with equipment such as hydrogen generators, fuel cell stacks, backup batteries, system control units and compressors; it can also serve only as the external interface of the hydrogen storage container to connect hydrogen hoses, cables and other energy and material exchange channels.

[0067] In the present application, hydrogen is stored in a hydrogen storage container, which is placed in water. The hydrogen has no direct contact with the water in the environment, thus avoiding contamination of the hydrogen by water vapor and dissolved substances in the water (such as salt). In this way, there is no need to purify the hydrogen released from the hydrogen storage container.

[0068] The water depth of the hydrogen storage container can be adjusted as needed. The hydrostatic pressure at different water depths is different. The external hydrostatic pressure reduces the internal and external pressure difference on the airbag skin. The deeper the water depth of the container, the greater the water pressure, and the more compressed hydrogen that can be filled. Therefore, this solution can flexibly adjust the hydrogen storage capacity of the hydrogen storage container by adjusting the overpressure capacity of the hydrogen storage container and the water depth of the hydrogen storage container.

[0069] Working process of using this application system:

[0070] (1) System assembly

[0071] Build a floating platform on the water surface and fix it through an anchoring system or dynamic positioning system (it can also be modified to use an existing floating platform on the water surface, such as an offshore floating wind power, photovoltaic power generation platform, offshore hydrogen production platform, etc.); the hydrogen storage container is in an uninflated state, connect the hydrogen storage container with the position adjustment and damage protection unit, and connect the relevant hydrogen transmission pipelines, cables, power lines, etc. to complete the assembly of the underwater part. (2) Deployment and emptying

[0072] The assembled underwater hydrogen storage system is lowered to the surface of the water. At this point, the hydrogen storage container is still in the unfolded state. Through the position adjustment and damage protection unit, the hydrogen storage container is tilted downward or inverted until the lower end valve of the hydrogen storage container floats to the surface.

[0073] Pump a certain amount of pure water into the hydrogen storage container through the hydrogen transmission pipeline. At the same time, open the valve at the lower end of the hydrogen storage container until the air in the hydrogen storage container is emptied, and then close the valve at the lower end of the hydrogen storage container.

[0074] Then adjust the hydrogen storage container to an upright or upward tilted state, and pump a certain pressure of hydrogen into the hydrogen storage container through the hydrogen transmission pipeline (hose). Since the density of hydrogen is lower than that of water, open the valve at the lower end of the hydrogen storage container until all the pure water in the hydrogen storage container is discharged through the valve at the lower end, and then close the valve at the lower end.

[0075] (3) Hydrogen charging

[0076] After all the water in the hydrogen storage container is drained and the lower end valve is closed, the hydrogen storage container is pulled down and adjusted to a predetermined working depth, such as 30 meters underwater, through the position adjustment and damage protection unit.

[0077] Hydrogen at a certain pressure is pumped into the hydrogen storage container through a hydrogen transmission pipeline (hose), and the hydrogen storage container is deployed. At this time, the buoyancy of the underwater part of the system increases, but due to the position adjustment and damage protection unit, the hydrogen storage container is limited to the working depth until the hydrogen storage container is fully deployed. The internal pressure of the hydrogen storage container is approximately greater than the surrounding water pressure (about 0.3MPA).

[0078] At this time, if the hydrogen storage container has overpressure capacity, hydrogen can still be added to the hydrogen storage container until the safety limit allowed by the structural strength. For example, if the overpressure is 0.3MPA, the actual internal pressure of the hydrogen storage container is 0.6MPA, and the hydrogen storage capacity is about twice that of the fully expanded state.

[0079] If there is still hydrogen that needs to be stored at this time, the depth of the underwater part is adjusted through position adjustment and damage protection unit, such as descending to 60 meters underwater; at this time, the hydrogen storage container is subjected to greater hydrostatic pressure, and the overpressure state disappears; so hydrogen can still be added to the hydrogen storage container to the safety limit allowed by the structural strength, such as 0.3MPA. At this time, the actual internal pressure of the hydrogen storage container is 0.9MPA, and the hydrogen storage capacity of the hydrogen storage container is about 3 times that of the fully expanded state.

[0080] After filling with more hydrogen, the volume of the hydrogen storage container (especially the hydrogen storage container with overpressure capability) changes little, but more hydrogen is filled, so the volume density of the underwater part of the system becomes larger. Therefore, the position adjustment and damage protection unit can be adjusted to make the volume density of the underwater part of the system equal to the density of the surrounding water again, so that the hydrogen storage container is in a suspended state.

[0081] (4) Hydrogen release

[0082] If the hydrogen storage container is in an overpressure state, hydrogen can be directly extracted from the hydrogen storage container through the hydrogen transfer hose using a compression pump; at this time, the volume density of the underwater hydrogen storage system gradually decreases, and the hydrogen storage container will gradually float up until the density is balanced.

[0083] If further release of hydrogen is required, the underwater part can be lifted up by a cable so that the hydrogen storage container can release more hydrogen. During the operation, the external pressure of the hydrogen storage container should be avoided to be greater than the internal pressure.

[0084] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An underwater hydrogen storage system, characterized in that: It includes a water surface floating platform arranged on the water surface, a hydrogen storage container arranged in the water, and a position adjustment and damage protection unit arranged in the water; the water surface floating platform is connected to the hydrogen storage container; The position adjustment and damage protection unit includes a first cable, a second cable, a first counterweight, a first pulley block, a second pulley block, and a protection unit covering the outside of the hydrogen storage container; The first pulley group is movably connected to the water floating platform; one end of the first cable is connected to the first pulley group, and the other end is connected to the first counterweight block; the second pulley group is movably connected to the first counterweight block; one end of the second cable is connected to the first pulley group, and the other end is connected to the protection unit through the second pulley group.

2. The underwater hydrogen storage system according to claim 1, characterized in that: The first pulley group is movably connected to the edge of the water floating platform; the second pulley group is movably connected to the edge of the first counterweight block; and a margin is provided on the second cable between the second pulley group and the protection unit.

3. The underwater hydrogen storage system according to claim 1, characterized in that: The position adjustment and damage protection unit further includes a third cable, a fourth cable, a second counterweight, a third pulley set, and a fourth pulley set; The third pulley group is movably connected to the water floating platform; one end of the third cable is connected to the third pulley group, and the other end is connected to the second counterweight block; the fourth pulley group is movably connected to the second counterweight block; one end of the fourth cable is connected to the third pulley group, and the other end is connected to the protection unit through the fourth pulley group.

4. The underwater hydrogen storage system according to claim 3, characterized in that: The third pulley group is movably connected to the edge of the water floating platform; the fourth pulley group is movably connected to the edge of the second counterweight block; the fourth cable between the fourth pulley group and the protection unit is provided with a margin; one end of the protection unit is connected to the second cable, and the other end is connected to the fourth cable.

5. The underwater hydrogen storage system according to claim 1, characterized in that: The hydrogen storage container includes two flanges and an inflatable bladder, and the two flanges are respectively arranged at the two ends of the inflatable bladder; the inflatable bladder is composed of several pieces of skin radial flaps; reinforcing ribs are provided at the joints of two adjacent pieces of skin radial flaps, and the two ends of the reinforcing ribs are connected to the flanges; the protective unit is sleeved on the outside of the inflatable bladder.

6. The underwater hydrogen storage system according to claim 5, characterized in that: The splicing is achieved by sewing, welding and applying a barrier coating; along the direction of the splicing, the length of the skin radial petal is greater than the length of the reinforcement rib; the length of the reinforcement rib is equal to the length of the splicing.

7. The underwater hydrogen storage system according to claim 5, characterized in that: The reinforcing ribs are rigid bars or flexible ropes; a cable net is provided on the outer side of the middle portion of the inflatable bag; and the cable net can slide relative to the inflatable bag.

8. The underwater hydrogen storage system according to claim 7, characterized in that: The flange is provided with a plurality of positioning holes; the reinforcing ribs and the cable net are connected to the flange through the positioning holes.

9. The underwater hydrogen storage system according to claim 5, characterized in that: The center of the flange is provided with an annular opening, the center of the annular opening is provided with a connecting pipe communicating with the inflatable bag; the connecting pipe is provided with a valve for controlling the connecting pipe; The flange is also provided with a sensor for monitoring the environmental parameters of the inflatable bladder; the environmental parameters include bladder pressure, water depth, water flow velocity, water flow direction or temperature.

10. The underwater hydrogen storage system according to claim 9, characterized in that: The water surface floating platform is provided with a system control unit, and the system control unit is connected to the sensor; The underwater hydrogen storage system also includes a hydrogen production electrolyzer and a fuel cell generator arranged on land or a floating platform on the water surface. The hydrogen production electrolyzer or fuel cell generator is connected to the floating platform on the water surface through a first hydrogen transmission pipeline. The end of the first hydrogen transmission pipeline close to the floating platform on the water surface is connected to the hydrogen storage container through a second hydrogen transmission pipeline; the floating platform on the water surface is connected to the land or floating platform on the water surface through a connecting line.

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