An adiabatic system for a liquid hydrogen tank

Abstract

This invention discloses a thermal insulation system for a liquid hydrogen storage tank, comprising an inner container of the liquid hydrogen storage tank, an outer container of the liquid hydrogen storage tank, an insulation layer, two working fluids, a first vapor cooling screen assembly (cryogenic hydrogen working fluid), a second cooling screen assembly (cryogenic working fluid), and a third vapor cooling screen assembly (cryogenic nitrogen working fluid). The insulation layer is disposed between the inner container and the outer container of the liquid hydrogen storage tank. The first vapor cooling screen assembly is partially disposed within the insulation layer and is in communication with the gaseous region of the inner container of the liquid hydrogen storage tank. The second and third vapor cooling screen assemblies are also partially disposed within the insulation layer and are in communication with the second cooling screen assembly. This application not only improves the thermal insulation performance of the liquid hydrogen storage tank, thereby reducing the evaporation rate of liquid hydrogen and the risk of hydrogen leakage, but also enables the recovery of the working fluid for process use, saving costs.

Description

Technical Field

[0001] This invention relates to the technical field of efficient hydrogen energy storage and energy saving, and particularly to an insulation system for liquid hydrogen storage tanks. Background Technology

[0002] Safe, reliable, and efficient hydrogen storage technology is crucial for realizing hydrogen energy utilization. Liquid hydrogen has attracted widespread attention in the industry due to its high energy density. Because the boiling point of liquid hydrogen is lower than that of liquid oxygen and liquid nitrogen, the insulation performance of storage tanks is more critical. High-vacuum multilayer insulation can achieve good insulation performance. Under high-vacuum insulation, the convective and conductive heat transfer of a small amount of gas has little impact on the heat dissipation of the liquid hydrogen storage tank. However, due to the large temperature difference between liquid hydrogen and the external environment, radiation becomes the main mode of heat intrusion into the liquid hydrogen storage tank. Although the radiant shields in the multilayer insulation material can suppress radiative heat transfer to some extent, this passive thermal protection still allows some heat to leak into the liquid hydrogen through the multilayer insulation material. This heat forces the liquid hydrogen to evaporate, causing the pressure in the tank's gas pillow to rise. Active venting is required to reduce the pressure, resulting in a significant waste of hydrogen, leading to both economic losses and safety hazards during the discharge process. Furthermore, directly releasing 20K hydrogen into the 300K atmosphere also wastes cooling capacity. Summary of the Invention

[0003] Therefore, it is necessary to provide an insulation system for liquid hydrogen storage tanks that can improve the insulation performance of liquid hydrogen storage tanks, thereby reducing the evaporation of liquid hydrogen and the risk of hydrogen leakage, and to recycle the working fluid as process gas to save costs.

[0004] An insulation system for a liquid hydrogen storage tank, comprising:

[0005] The inner container of the liquid hydrogen storage tank contains liquid hydrogen.

[0006] An outer container for a liquid hydrogen storage tank is fitted over the outer container of the inner container of the liquid hydrogen storage tank;

[0007] An insulation layer is disposed between the inner container of the liquid hydrogen storage tank and the outer container of the liquid hydrogen storage tank;

[0008] The first vapor cooling screen assembly is partially disposed within the insulation layer and sleeved on the outside of the inner container of the liquid hydrogen storage tank. The first vapor cooling screen assembly is connected to the top of the inner container of the liquid hydrogen storage tank. The first vapor cooling screen assembly is used to allow the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank to circulate. The first vapor cooling screen assembly is also configured to recover the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank.

[0009] A second cooling screen assembly is partially disposed within the insulation layer, spaced apart from the first vapor cooling screen assembly, and sleeved over the first vapor cooling screen assembly. The second cooling screen assembly stores a liquid working fluid, which absorbs external heat and undergoes a phase change to form a gaseous working fluid.

[0010] The third vapor cooling screen assembly is partially disposed within the insulation layer, spaced apart from the second cooling screen assembly, and is sleeved on the outside of the second cooling screen assembly. The third vapor cooling screen assembly is also connected to the top of the second cooling screen assembly. The third vapor cooling screen assembly is used to allow the gaseous working fluid output by the second cooling screen assembly to circulate, and is also configured to recover the gaseous working fluid output by the second cooling screen assembly.

[0011] Optionally, the first vapor cooling screen assembly includes a first vapor cooling screen and a first gas cylinder group. The second cooling screen assembly is sleeved on the outside of the first vapor cooling screen. The inlet end of the first vapor cooling screen is connected to the gas phase outlet end of the inner container of the liquid hydrogen storage tank. The outlet end of the first vapor cooling screen is connected to the first gas cylinder group. The first gas cylinder group is disposed outside the outer container of the liquid hydrogen storage tank. The first vapor cooling screen is used to allow the hydrogen vapor evaporated from the inner container of the liquid hydrogen storage tank to circulate. The first gas cylinder group is used to recover the hydrogen vapor evaporated from the inner container of the liquid hydrogen storage tank.

[0012] Optionally, the first vapor cooling screen assembly further includes a first compressor, one end of which is connected to the outlet end of the first vapor cooling screen, and the other end of which is connected to the first gas cylinder group. The first compressor is used to compress the hydrogen output by the first vapor cooling screen, and the first gas cylinder group is used to contain the hydrogen output by the first compressor.

[0013] Optionally, the first vapor cooling screen assembly further includes a first gas storage tank, the inlet end of which is connected to the outlet end of the first vapor cooling screen, and the outlet end of which is connected to one end of the first compressor. The first gas storage tank is used to contain the hydrogen output from the first vapor cooling screen and to deliver the hydrogen to the first compressor.

[0014] Optionally, the second cooling screen assembly includes a second cooling screen and a storage tank. The second cooling screen is sleeved outside the first vapor cooling screen. The storage tank contains a liquid working fluid and is located outside the outer container of the liquid hydrogen storage tank. The inlet end of the second cooling screen is connected to the storage tank, and the outlet end of the second cooling screen is connected to the third vapor cooling screen assembly.

[0015] Optionally, the third vapor cooling screen assembly includes a third vapor cooling screen and a second gas cylinder group. The third vapor cooling screen is sleeved outside the second cooling screen. The inlet end of the third vapor cooling screen is connected to the gas phase outlet end of the second cooling screen, and the outlet end of the third vapor cooling screen is connected to the second gas cylinder group. The second gas cylinder group is located outside the outer container of the liquid hydrogen storage tank. The third vapor cooling screen allows the flow of the gaseous working fluid output by the second cooling screen, and the second gas cylinder group is used to recover the gaseous working fluid output by the third vapor cooling screen.

[0016] Optionally, the third vapor cooling screen assembly further includes a second compressor, one end of which is connected to the outlet end of the third vapor cooling screen, and the other end of which is connected to the second gas cylinder group. The second compressor is used to compress the gaseous working fluid output by the third vapor cooling screen, and the second gas cylinder group is used to contain the gaseous working fluid output by the second compressor.

[0017] Optionally, the third vapor cooling screen assembly further includes a second gas storage tank, the inlet end of which is connected to the outlet end of the third vapor cooling screen, and the outlet end of which is connected to one end of the second compressor. The second gas storage tank is used to contain the gaseous working fluid output by the third vapor cooling screen and to deliver the gaseous working fluid to the second compressor.

[0018] Optionally, the insulation layer includes a first insulation layer, a second insulation layer, a third insulation layer, and a fourth insulation layer. The first insulation layer is disposed between the inner container of the liquid hydrogen storage tank and the first vapor cooling screen assembly. The second insulation layer is disposed between the first vapor cooling screen assembly and the second cooling screen assembly. The third insulation layer is disposed between the second cooling screen assembly and the third vapor cooling screen assembly. The fourth insulation layer is disposed between the third vapor cooling screen assembly and the outer container of the liquid hydrogen storage tank.

[0019] Optionally, the insulation layer is formed of multiple layers of insulation material.

[0020] This application provides a thermal insulation system for a liquid hydrogen storage tank. An insulation layer is filled between the inner container and the outer container of the liquid hydrogen storage tank. Compared to existing technologies, the insulation layer of this application has a first vapor cooling screen assembly, a second cooling screen assembly, and a third vapor cooling screen assembly arranged sequentially from the inside out. The second and third vapor cooling screen assemblies are connected. The second cooling screen assembly stores a cryogenic liquid working fluid. This liquid working fluid can block and absorb heat from the outside that crosses the third vapor cooling screen assembly, thereby reducing the evaporation of liquid hydrogen. After absorbing external heat, the liquid working fluid transforms into a gaseous working fluid and continues to be output into the third vapor cooling screen assembly. The cryogenic gaseous working fluid circulates within the third vapor cooling screen assembly, absorbing heat from the outside that enters the outer container of the liquid hydrogen storage tank. This application reduces the amount of external heat entering the second cooling screen assembly, thereby further reducing the evaporation of liquid hydrogen. Furthermore, by providing a first vapor cooling screen assembly connected to the inner container of the liquid hydrogen storage tank, the application utilizes the low-temperature hydrogen vaporized from the liquid hydrogen to block and absorb external heat passing through the third vapor cooling screen assembly and the second cooling screen assembly, further reducing the evaporation of liquid hydrogen. The first vapor cooling screen assembly fully utilizes the cooling energy released by the evaporation of liquid hydrogen itself, improving the energy efficiency and economy of the insulation system for the liquid hydrogen storage tank. In addition, the first vapor cooling screen assembly can recover the hydrogen vapor evaporated from the inner container of the liquid hydrogen storage tank, and the third vapor cooling screen assembly can recover the gaseous working fluid output by the second cooling screen assembly, enabling the recycling of hydrogen and nitrogen working fluids and reducing the risk of hydrogen diffusion. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the insulation system for a liquid hydrogen storage tank in one embodiment;

[0023] Figure 2 This is a schematic diagram of the overall structure of the insulation system for a liquid hydrogen storage tank in one embodiment;

[0024] Figure 3 This is a partial structural diagram of an insulation system for a liquid hydrogen storage tank in one embodiment.

[0025] Component names and numbers in the diagram: 1. Storage tank; 2. Sixth valve; 3. Liquid hydrogen; 4. Inner container of liquid hydrogen storage tank; 5. First insulation layer; 6. First vapor cooling screen; 7. Second insulation layer; 8. Second cooling screen; 9. Third insulation layer; 10. Third vapor cooling screen; 11. Fourth insulation layer; 12. Outer container of liquid hydrogen storage tank; 13. First valve; 14. Seventh valve; 15. Eighth valve; 16. Second gas storage tank; 17. Ninth valve; 18. Tenth valve; 19. Second compressor; 20. Eleventh valve; 21. Second gas cylinder group; 22. Second valve; 23. First gas storage tank; 24. Third valve; 25. Fourth valve; 26. First compressor; 27. Fifth valve; 28. First gas cylinder group; 29. ​​Insulation layer; 30. First vapor cooling screen assembly; 31. Second cooling screen assembly; 32. Third vapor cooling screen assembly.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0029] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] refer to Figure 1A thermal insulation system for a liquid hydrogen storage tank includes an inner container 4, an outer container 12, an insulation layer 29, a first vapor cooling screen assembly 30, a second cooling screen assembly 31, and a third vapor cooling screen assembly 32. The inner container 4 contains liquid hydrogen 3. The outer container 12 is fitted over the inner container 4. The insulation layer 29 is disposed between the inner container 4 and the outer container 12. The first vapor cooling screen assembly 30 is partially disposed within the insulation layer 29 and fitted over the inner container 4. The first vapor cooling screen assembly 30 communicates with the top of the inner container 4 and is used to allow the flow of hydrogen vapor evaporated from the inner container 4. The first vapor cooling screen assembly 30 also recovers vapor vapor evaporated from the inner container 4. The second cooling screen assembly 31 is partially disposed within the insulation layer 29, spaced apart from the first vapor cooling screen assembly 30, and is fitted over the outside of the first vapor cooling screen assembly 30. The second cooling screen assembly 31 is used to store the liquid working fluid, and the liquid working fluid absorbs external heat and undergoes a phase change to form a gaseous working fluid. The third vapor cooling screen assembly 32 is partially disposed within the insulation layer 29, spaced apart from the second cooling screen assembly 31, and is fitted over the outside of the second cooling screen assembly 31. The third vapor cooling screen assembly 32 is also connected to the top of the second cooling screen assembly 31. The third vapor cooling screen assembly is used to allow the gaseous working fluid output by the second cooling screen assembly 31 to circulate, and is also used to recover the gaseous working fluid output by the second cooling screen assembly 31.

[0031] This application provides a heat insulation system for a liquid hydrogen storage tank. A heat insulation layer 29 is filled between the inner container 4 and the outer container 12 of the liquid hydrogen storage tank. Compared to the prior art, the heat insulation layer 29 of this application has a first vapor cooling screen assembly 30, a second cooling screen assembly 31, and a third vapor cooling screen assembly 32 arranged sequentially from the inside out. The second cooling screen assembly 31 and the third vapor cooling screen assembly 32 are connected. The second cooling screen assembly 31 contains a liquid working fluid. The low-temperature liquid working fluid can block and absorb the heat intruding from the outside across the third vapor cooling screen assembly 32, thereby reducing the evaporation of liquid hydrogen 3. After absorbing external heat, the liquid working fluid transforms into a gaseous working fluid and continues to be output into the third vapor cooling screen assembly 32. The low-temperature gaseous working fluid circulates inside the third vapor cooling screen, absorbing the heat intruding into the outer container 12 of the liquid hydrogen storage tank. The first vapor cooling screen assembly 30, connected to the inner container 4 of the liquid hydrogen storage tank, can reduce the amount of external heat entering the second cooling screen assembly 31, thereby further reducing the evaporation of liquid hydrogen 3. The first vapor cooling screen assembly 30 can use the low-temperature hydrogen gas evaporated from the liquid hydrogen 3 to block and absorb the external heat passing through the third vapor cooling screen assembly 32 and the second cooling screen assembly 31, further reducing the evaporation of liquid hydrogen 3. The first vapor cooling screen assembly 30 makes full use of the cold energy released by the evaporation of liquid hydrogen 3 itself, improving the energy efficiency and economy of the insulation system for liquid hydrogen storage tanks. In addition, the first vapor cooling screen assembly 30 can also recover the hydrogen gas evaporated from the inner container 4 of the liquid hydrogen storage tank, and the third vapor cooling screen assembly 32 can recover the gaseous working fluid output by the second cooling screen assembly 31, which can realize the recycling of hydrogen gas and gaseous working fluid and reduce the risk of hydrogen diffusion.

[0032] Specifically, a vacuum environment is maintained between the inner container 4 of the liquid hydrogen storage tank and the outer container 12 of the liquid hydrogen storage tank to suppress the heat conduction of the internal gas.

[0033] Specifically, the liquid working fluid is liquid nitrogen, and the temperature of the liquid nitrogen contained inside the second cooling screen assembly 31 is 77K. After the liquid working fluid changes phase to a gaseous working fluid, it becomes low-temperature nitrogen gas that flows and absorbs heat in the third vapor cooling screen assembly 32, where the temperature of the liquid hydrogen is 20.4K.

[0034] Furthermore, liquid nitrogen is used because it is low in cost, has high cooling capacity, and is easy to produce. By using low-cost liquid nitrogen to pass through the second cooling screen assembly 31, it can effectively resist and absorb the heat leaking into the third vapor cooling screen assembly 32 and the insulation layer 29 from the outside, thereby reducing the evaporation of high-cost liquid hydrogen.

[0035] This application not only meets the insulation requirements of liquid hydrogen storage tanks, but is also applicable to insulation technologies for lower-temperature and more expensive liquid rare gases such as liquid helium, demonstrating its strong versatility.

[0036] refer to Figure 1 and Figure 3The first vapor cooling screen assembly 30 includes a first vapor cooling screen 6 and a first gas cylinder group 28. The second cooling screen assembly 31 is sleeved on the outside of the first vapor cooling screen 6. The inlet end of the first vapor cooling screen 6 is connected to the gas phase outlet end of the inner container 4 of the liquid hydrogen storage tank. The outlet end of the first vapor cooling screen 6 is connected to the first gas cylinder group 28. The first gas cylinder group 28 is located outside the outer container 12 of the liquid hydrogen storage tank. The first vapor cooling screen 6 is used to allow the hydrogen gas evaporated from the inner container 4 of the liquid hydrogen storage tank to circulate. The first gas cylinder group 28 is used to recover the hydrogen gas evaporated from the inner container 4 of the liquid hydrogen storage tank.

[0037] Specifically, the first vapor cooling screen 6 has pipes inside, through which hydrogen gas flows.

[0038] Specifically, the cooling capacity of the hydrogen gas evaporated from the liquid hydrogen is fully utilized by the first vapor cooling screen 6, and the flammable and explosive hydrogen gas is recovered through the first gas cylinder group 28, which can achieve "zero leakage" of hydrogen gas, reduce the risk of hydrogen gas leakage, and thus significantly increase the safety of liquid hydrogen storage.

[0039] refer to Figure 1 and Figure 2 The first vapor cooling screen assembly 30 also includes a first compressor 26. One end of the first compressor 26 is connected to the outlet end of the first vapor cooling screen 6, and the other end of the first compressor 26 is connected to the first gas cylinder group 28. The first compressor 26 is used to compress the hydrogen output from the first vapor cooling screen 6, and the first gas cylinder group 28 is used to contain the hydrogen output from the first compressor 26.

[0040] Specifically, the first compressor 26 is a hydrogen compressor, which can compress hydrogen to reduce its volume so that the first gas cylinder group 28 can store more hydrogen.

[0041] refer to Figure 1 The first vapor cooling screen assembly 30 also includes a first gas storage tank 23. The inlet end of the first gas storage tank 23 is connected to the outlet end of the first vapor cooling screen 6, and the outlet end of the first gas storage tank 23 is connected to one end of the first compressor 26. The first gas storage tank 23 is used to contain the hydrogen output from the first vapor cooling screen 6 and to deliver the hydrogen to the first compressor 26.

[0042] Specifically, the first steam cooling screen 6, the first gas storage tank 23, the first compressor 26, and the first gas cylinder group 28 are connected in sequence through connecting pipes.

[0043] A first valve 13 and a second valve 22 are connected in series on the connecting pipe between the first steam cooling screen 6 and the first gas storage tank 23. A third valve 24 and a fourth valve 25 are connected in series on the connecting pipe between the first gas storage tank 23 and the first compressor 26. A fifth valve 27 is connected on the connecting pipe between the first compressor 26 and the first gas cylinder group 28.

[0044] The inlet pipe e of the first vapor cooling screen 6 is connected to the outlet pipe d of the inner container 4 of the liquid hydrogen storage tank, so that the low-temperature hydrogen gas evaporated from the liquid hydrogen 3 is introduced into the first vapor cooling screen 6. This allows the low-temperature hydrogen gas to flow along the pipes inside the first vapor cooling screen 6 to absorb heat leakage from the outside. It then flows into the first gas storage tank 23 for pressurized storage through the first valve 13 and the second valve 22. When a certain amount of hydrogen gas is stored inside the first gas storage tank 23, the third valve 24, the fourth valve 25 and the fifth valve 27 are opened, so that the hydrogen gas in the first gas storage tank 23 enters the first compressor 26 through the connecting pipes via the third valve 24 and the fourth valve 25 for compression. Then, the pressurized hydrogen gas is stored in the first gas cylinder group 28 through the fifth valve 27.

[0045] refer to Figure 1 The second cooling screen assembly 31 includes a second cooling screen 8 and a storage tank 1. The second cooling screen 8 is sleeved outside the first vapor cooling screen 6. The storage tank 1 contains a liquid working fluid and is located outside the outer container 12 of the liquid hydrogen storage tank. The inlet end of the second cooling screen 8 is connected to the storage tank 1, and the outlet end of the second cooling screen 8 is connected to the third vapor cooling screen assembly 32.

[0046] Specifically, the second cooling screen 8 has internal pipes through which liquid working fluid flows.

[0047] The second cooling screen 8 and the storage tank 1 are connected by a connecting pipe a, and the connecting pipe a between the second cooling screen 8 and the storage tank 1 is equipped with a sixth valve 2. The storage tank 1 contains cryogenic liquid nitrogen, which can replenish the liquid working medium to the second cooling screen 8 in a timely manner. The liquid nitrogen flowing in the second cooling screen 8 can absorb the heat that has penetrated into the insulation layer 29 from the external environment.

[0048] In this embodiment, a pump is installed in the connecting pipe a between the second cooling screen 8 and the storage tank 1 to pump the liquid working fluid from the storage tank 1 to the second cooling screen 8.

[0049] refer to Figure 1 The third vapor cooling screen assembly 32 includes a third vapor cooling screen 10 and a second gas cylinder group 21. The third vapor cooling screen 10 is sleeved outside the second cooling screen 8. The inlet end of the third vapor cooling screen 10 is connected to the gas phase outlet end of the second cooling screen 8, and the outlet end of the third vapor cooling screen 10 is connected to the second gas cylinder group 21. The second gas cylinder group 21 is located outside the outer container 12 of the liquid hydrogen storage tank. The third vapor cooling screen 10 is used for the flow of the gaseous working fluid output by the second cooling screen 8, and the second gas cylinder group 21 is used to recover the gaseous working fluid output by the third vapor cooling screen 10.

[0050] Specifically, when the low-temperature nitrogen flowing in the third vapor cooling screen 10 cannot resist the heat leaking in from the outside, the heat leaking in from the outside can accelerate the evaporation of liquid nitrogen in the second cooling screen 8, increase the amount of nitrogen output from the second cooling screen 8 to the third vapor cooling screen 10, and thus quickly replenish the cooling capacity of the third vapor cooling screen 10.

[0051] Specifically, the third steam cooling screen 10 is equipped with pipes inside. After the second cooling screen 8 absorbs heat leakage at low temperature, it transforms into low-temperature nitrogen gas. The inlet pipe h of the third steam cooling screen 10 and the outlet pipe g of the second cooling screen 8 are connected in series. The low-temperature nitrogen gas enters the inlet pipe h of the third steam cooling screen 10 from the outlet pipe g of the second cooling screen 8. It flows through the internal pipes of the third steam cooling screen 10, absorbs heat leakage from the outside intruding into the insulation layer 29, and then flows out from the outlet pipe j of the third steam cooling screen 10 to the inside of the second gas cylinder group 21 for storage.

[0052] refer to Figure 1 The third vapor cooling screen assembly 32 also includes a second compressor 19. One end of the second compressor 19 is connected to the outlet end of the third vapor cooling screen 10, and the other end of the second compressor 19 is connected to the second gas cylinder group 21. The second compressor 19 is used to compress the gaseous working fluid output by the third vapor cooling screen 10, and the second gas cylinder group 21 is used to contain the gaseous working fluid output by the second compressor 19.

[0053] Specifically, the second compressor 19 is an air compressor. By compressing the nitrogen gas and reducing its volume, the second gas cylinder group 21 can hold more nitrogen gas.

[0054] refer to Figure 2 The third vapor cooling screen assembly 32 also includes a second gas storage tank 16. The inlet end of the second gas storage tank 16 is connected to the outlet end of the third vapor cooling screen 10, and the outlet end of the second gas storage tank 16 is connected to one end of the second compressor 19. The second gas storage tank 16 is used to contain the gaseous working fluid output by the third vapor cooling screen 10 and to deliver the gaseous working fluid to the second compressor 19.

[0055] Specifically, the third steam cooling screen 10, the second gas storage tank 16, the second compressor 19, and the second gas cylinder group 21 are connected in sequence through connecting pipes. The connecting pipe between the third steam cooling screen 10 and the second gas storage tank 16 is equipped with a seventh valve 14 and an eighth valve 15. The connecting pipe between the second gas storage tank 16 and the second compressor 19 is equipped with a ninth valve 17 and a tenth valve 18. The connecting pipe between the second compressor 19 and the second gas cylinder group 21 is equipped with an eleventh valve 20.

[0056] The outlet pipe of the third steam cooling screen 10 is connected to the inlet end of the second gas storage tank 16. Nitrogen enters the second gas storage tank 16 through the seventh valve 14 and the eighth valve 15 for pressurized storage. When a certain amount of nitrogen is stored in the second gas storage tank 16, the ninth valve 17, the tenth valve 18 and the eleventh valve 20 are opened, so that the nitrogen in the second gas storage tank 16 enters the second compressor 19 through the connecting pipe through the ninth valve 17 and the tenth valve 18 for compression, and then the pressurized nitrogen is stored in the second gas cylinder group 21 through the eleventh valve 20.

[0057] Furthermore, the pipes inside the first steam cooling screen 6, the second cooling screen 8, and the third steam cooling screen 10 are all made of high-vacuum multilayer insulation material or polyurethane foam insulation, and the connecting pipes are all made of stainless steel.

[0058] Specifically, valves 13, 2, and 14 are cryogenic shut-off valves, while valves 22, 24, 25, 27, 15, 17, 18, and 20 are ambient temperature regulating valves. This is because the working fluids flowing through valves 13, 2, and 14 are all at low temperatures, and cryogenic shut-off valves are suitable for the flow of cryogenic working fluids without damage.

[0059] In addition, after the cryogenic working fluid is introduced into the vapor cooling screen, the small amount of gas slowly released from the insulation layer 29 and the connecting pipeline, as well as the trace amount of air leaked into the outer container 12 of the liquid hydrogen storage tank, can be condensed and adsorbed on the surface of the cooling screen to a certain extent. This application adopts a three-cooling-screen structure, which increases the adsorption area of ​​the leaked gas in the cooling screen and further reduces the heat conduction of the residual gas in the high vacuum.

[0060] refer to Figure 1 The insulation layer 29 includes a first insulation layer 5, a second insulation layer 7, a third insulation layer 9, and a fourth insulation layer 11. The first insulation layer 5 is disposed between the inner container 4 of the liquid hydrogen storage tank and the first vapor cooling screen 6. The second insulation layer 7 is disposed between the first vapor cooling screen 6 and the second cooling screen 8. The third insulation layer 9 is disposed between the second cooling screen 8 and the third vapor cooling screen 10. The fourth insulation layer 11 is disposed between the third vapor cooling screen 10 and the outer container 12 of the liquid hydrogen storage tank.

[0061] Specifically, the first insulation layer 5 is used to resist the heat conduction caused by the temperature difference between the first vapor cooling screen 6 and the inner container 4 of the liquid hydrogen storage tank, and to suppress the loss of cold energy caused by heat exchange between the liquid hydrogen, the first vapor cooling screen 6 and external radiation, thereby reducing the evaporation of liquid hydrogen.

[0062] Specifically, the second insulation layer 7 can suppress heat conduction caused by the temperature difference between the first vapor cooling screen 6 and the second cooling screen 8, as well as suppress radiative heat exchange between the inner container 4 of the liquid hydrogen storage tank and the outside, thereby further reducing the evaporation of liquid hydrogen.

[0063] Specifically, the third insulation layer 9 can reduce the heat conduction caused by the temperature difference between the second cooling screen 8 and the third vapor cooling screen 10, and suppress the radiative heat exchange between the inner container 4 of the liquid hydrogen storage tank and the outside, thereby further reducing the evaporation of liquid hydrogen.

[0064] Specifically, the fourth insulation layer 11 can reduce the radiative heat exchange between the outside and the third vapor cooling screen 10, the second cooling screen 8, the first vapor cooling screen 6 and the liquid hydrogen storage tank container 4, respectively, thereby further reducing the evaporation of liquid hydrogen.

[0065] refer to Figure 2 The insulation layer 29 is formed of multiple layers of insulation material and is disposed in a high vacuum environment. The multiple layers of insulation material have good insulation performance, which can improve the insulation performance of this application and reduce the evaporation of liquid hydrogen.

[0066] In this embodiment, a 4000 cubic meter spherical liquid hydrogen storage tank is used. The diameter of the inner container of the liquid hydrogen storage tank is 19.7m, and the diameter of the outer container 12 of the liquid hydrogen storage tank is 21.4m. Taking into account seismic load, wind load, weight of the storage tank and manufacturing cost, it is found that when the multi-layer insulation material of the insulation layer 29 is 80 layers, the overall insulation performance of the liquid hydrogen storage tank is optimal.

[0067] The operation process of an insulation system for a liquid hydrogen storage tank is as follows: First, a first insulation layer 5 is wrapped around the outer surface of the inner container 4 of the liquid hydrogen storage tank. A first vapor cooling screen 6 is wrapped around the outer surface of the first insulation layer 5, and the inlet pipe e of the first vapor cooling screen 6 is connected to the outlet pipe d of the liquid hydrogen storage tank. Low-temperature hydrogen can flow along the pipe inside the first vapor cooling screen 6 to absorb heat leakage. Then, the hydrogen after heat exchange is led out from the outlet pipe f of the first vapor cooling screen 6 to the connecting pipe n between the first vapor cooling screen 6 and the first gas storage tank 23. The connecting pipe n is sealed to the outer container 12 of the liquid hydrogen storage tank at point i by welding and led out to the outside of the liquid hydrogen storage tank. Finally, the hydrogen after cold energy utilization is temporarily stored in the first gas storage tank 23 through the connecting pipe n via the first valve 13 and the second valve 22. Hydrogen gas in the first gas storage tank 23 is introduced into the first compressor 26 through the connecting pipe between the first gas storage tank 23 and the first compressor 26, the third valve 24 and the fourth valve 25. After being compressed by the first compressor 26, it is stored in the first gas cylinder group 28 through the connecting pipe between the first compressor 26 and the first gas cylinder group 28 and the fifth valve 27, and can be directly used as industrial gas.

[0068] Then, the second insulation layer 7 is stacked on the outer surface of the first vapor cooling screen 6, and the second cooling screen 8 assembly 31 is wrapped around the outer surface of the second insulation layer 7. Then, the low temperature is introduced from the storage tank 1 through the connecting pipe a between the storage tank 1 and the second cooling screen 8 and the sixth valve 2 into the inlet pipe c of the second cooling screen 8. The inlet pipe c is led out to the outside of the liquid hydrogen storage tank outer container 12 and connected to the storage tank 1, and is welded and sealed at b. The outlet pipe g of the second cooling screen 8 is connected to the inlet pipe h of the third vapor cooling screen 10.

[0069] The third insulation layer 9 is wrapped around the outer surface of the second cooling screen 8, and the third vapor cooling screen 10 is wrapped around the outer surface of the third insulation layer 9. The second cooling screen 8 absorbs the heat leaking into the third insulation layer 9. The absorbed heat causes the internal low-temperature evaporation. The evaporated low-temperature nitrogen gas enters the pipeline of the third vapor cooling screen 10 from the outlet pipe g of the second cooling screen 8 for heat exchange. After the low-temperature nitrogen gas fully absorbs heat in the third vapor cooling screen 10, it flows out from the outlet pipe j of the third vapor cooling screen 10. The outlet pipe j is welded and sealed to the outer container 12 of the liquid hydrogen storage tank at k. The nitrogen gas passes through the seventh valve 14, the eighth valve 15 and the connecting pipe L between the third vapor cooling screen 10 and the second gas storage tank 16 in sequence into the second gas storage tank 16. Then, it passes through the outlet pipe m of the second gas storage tank 16 in sequence through the ninth valve 17 and the tenth valve 18 into the second compressor 19 for compression. The compressed nitrogen gas is recovered to the second gas cylinder group 21 through the eleventh valve 20. The recovered nitrogen can be used in industrial gases, enabling the recycling of the working fluid and improving the economic value of insulation systems for liquid hydrogen storage tanks.

[0070] Finally, the fourth insulation layer 11 is laid on the outer surface of the third vapor cooling screen 10, and the outer container 12 of the liquid hydrogen storage tank is covered on the outer surface of the fourth insulation layer 11. By sequentially assembling and installing the inner container 4 of the liquid hydrogen storage tank, the first insulation layer 5, the first vapor cooling screen 6, the second insulation layer 7, the second cooling screen 6, the third insulation layer 9, the third vapor cooling screen 10, the fourth insulation layer 11, and the outer container 12 of the liquid hydrogen storage tank, a sealed interlayer space is formed between the inner container 4 of the liquid hydrogen storage tank and the outer container 12 of the liquid hydrogen storage tank. Then, a vacuum operation is performed on the sealed interlayer space to suppress the heat conduction of the internal gas.

[0071] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. An insulation system for a liquid hydrogen storage tank, characterized in that, include: The inner container of the liquid hydrogen storage tank contains liquid hydrogen. An outer container for a liquid hydrogen storage tank is fitted over the outer container of the inner container of the liquid hydrogen storage tank; An insulation layer is disposed between the inner container of the liquid hydrogen storage tank and the outer container of the liquid hydrogen storage tank; The first vapor cooling screen assembly is partially disposed within the insulation layer and sleeved on the outside of the inner container of the liquid hydrogen storage tank. The first vapor cooling screen assembly is connected to the top of the inner container of the liquid hydrogen storage tank. The first vapor cooling screen assembly is used to allow the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank to circulate. The first vapor cooling screen assembly is also configured to recover the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank. A second cooling screen assembly is partially disposed within the insulation layer, spaced apart from the first vapor cooling screen assembly, and sleeved over the first vapor cooling screen assembly. The second cooling screen assembly stores a liquid working fluid, which absorbs external heat and undergoes a phase change to form a gaseous working fluid; the liquid working fluid is liquid nitrogen. The third vapor cooling screen assembly is partially disposed within the insulation layer, spaced apart from the second cooling screen assembly, and is sleeved on the outside of the second cooling screen assembly. The third vapor cooling screen assembly is also connected to the top of the second cooling screen assembly. The third vapor cooling screen assembly is used to allow the gaseous working fluid output by the second cooling screen assembly to circulate, and is also configured to recover the gaseous working fluid output by the second cooling screen assembly.

2. The insulation system for a liquid hydrogen storage tank according to claim 1, characterized in that, The first vapor cooling screen assembly includes a first vapor cooling screen and a first gas cylinder group. The second cooling screen assembly is sleeved on the outside of the first vapor cooling screen. The inlet end of the first vapor cooling screen is connected to the gas phase outlet end of the inner container of the liquid hydrogen storage tank. The outlet end of the first vapor cooling screen is connected to the first gas cylinder group. The first gas cylinder group is disposed outside the outer container of the liquid hydrogen storage tank. The first vapor cooling screen is used to allow the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank to circulate. The first gas cylinder group is used to recover the hydrogen gas evaporated from the inner container of the liquid hydrogen storage tank.

3. The insulation system for a liquid hydrogen storage tank according to claim 2, characterized in that, The first vapor cooling screen assembly further includes a first compressor, one end of which is connected to the outlet end of the first vapor cooling screen, and the other end of which is connected to the first gas cylinder group. The first compressor is used to compress the hydrogen output from the first vapor cooling screen, and the first gas cylinder group is used to contain the hydrogen output from the first compressor.

4. The insulation system for a liquid hydrogen storage tank according to claim 3, characterized in that, The first vapor cooling screen assembly further includes a first gas storage tank, the inlet end of which is connected to the outlet end of the first vapor cooling screen, and the outlet end of which is connected to one end of the first compressor. The first gas storage tank is used to contain the hydrogen output by the first vapor cooling screen and to deliver the hydrogen to the first compressor.

5. The insulation system for a liquid hydrogen storage tank according to claim 2, characterized in that, The second cooling screen assembly includes a second cooling screen and a storage tank. The second cooling screen is sleeved outside the first vapor cooling screen. The storage tank contains a liquid working fluid and is located outside the outer container of the liquid hydrogen storage tank. The inlet end of the second cooling screen is connected to the storage tank, and the outlet end of the second cooling screen is connected to the third vapor cooling screen assembly.

6. The insulation system for a liquid hydrogen storage tank according to claim 5, characterized in that, The third vapor cooling screen assembly includes a third vapor cooling screen and a second gas cylinder group. The third vapor cooling screen is sleeved on the outside of the second cooling screen. The inlet end of the third vapor cooling screen is connected to the gas phase outlet end of the second cooling screen, and the outlet end of the third vapor cooling screen is connected to the second gas cylinder group. The second gas cylinder group is located outside the outer container of the liquid hydrogen storage tank. The third vapor cooling screen allows the flow of the gaseous working fluid output by the second cooling screen, and the second gas cylinder group is used to recover the gaseous working fluid output by the third vapor cooling screen.

7. The insulation system for a liquid hydrogen storage tank according to claim 6, characterized in that, The third vapor cooling screen assembly also includes a second compressor. One end of the second compressor is connected to the outlet end of the third vapor cooling screen, and the other end of the second compressor is connected to the second gas cylinder group. The second compressor is used to compress the gaseous working fluid output by the third vapor cooling screen, and the second gas cylinder group is used to contain the gaseous working fluid output by the second compressor.

8. The insulation system for a liquid hydrogen storage tank according to claim 7, characterized in that, The third vapor cooling screen assembly further includes a second gas storage tank. The inlet end of the second gas storage tank is connected to the outlet end of the third vapor cooling screen, and the outlet end of the second gas storage tank is connected to one end of the second compressor. The second gas storage tank is used to contain the gaseous working fluid output by the third vapor cooling screen and to deliver the gaseous working fluid to the second compressor.

9. The insulation system for a liquid hydrogen storage tank according to claim 1, characterized in that, The insulation layer includes a first insulation layer, a second insulation layer, a third insulation layer, and a fourth insulation layer. The first insulation layer is disposed between the inner container of the liquid hydrogen storage tank and the first vapor cooling screen assembly. The second insulation layer is disposed between the first vapor cooling screen assembly and the second cooling screen assembly. The third insulation layer is disposed between the second cooling screen assembly and the third vapor cooling screen assembly. The fourth insulation layer is disposed between the third vapor cooling screen assembly and the outer container of the liquid hydrogen storage tank.

10. The insulation system for a liquid hydrogen storage tank according to claim 1, characterized in that, The insulation layer is formed of multiple layers of insulation material.

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