Apparatus and method for reducing venting losses using liquid hydrogen tank pressure

Abstract

This invention provides a device and method for reducing venting losses by utilizing the pressure of a liquid hydrogen storage tank, relating to the field of liquid hydrogen storage and transportation safety technology. The device includes an adsorption storage component, a desorption recovery component, and an adsorption enhancement component disposed within a gas cushion of a liquid hydrogen storage tank. The adsorption storage component is connected to the gas cushion via a one-way mechanical cryogenic valve and contains a solid adsorbent material and a vacuum insulation cylinder, used to adsorb and store evaporated gas when the tank pressure increases, thereby reducing the tank pressure. The adsorption enhancement component includes a cryogenic hydrogen regulating valve and a cryogenic heat exchanger, utilizing the throttling effect of high-pressure hydrogen in the tank to cool the adsorbent material and enhance its adsorption capacity. The desorption recovery component heats the adsorbent material through an intermediate heater, achieving controlled release of hydrogen. This invention achieves active management of liquid hydrogen storage tank pressure and efficient recovery of evaporated gas, significantly extending the venting cycle, reducing hydrogen loss, and improving the economy and safety of storage and transportation.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen storage and transportation safety technology, specifically to a device and method for reducing venting losses by utilizing the pressure of a liquid hydrogen storage tank. Background Technology

[0002] Liquid hydrogen (LH2) has become the mainstream technology for large-scale, long-distance hydrogen storage and transportation due to its extremely high volumetric energy density (more than 800 times that of gaseous hydrogen at room temperature and pressure). However, liquid hydrogen has an extremely low boiling point (-252.8°C), and even when stored in insulated tanks, it will inevitably produce evaporation gas (BOG) due to the infiltration of external heat. Therefore, the design and operation management of liquid hydrogen storage tanks are core technologies and safety criticalities in the hydrogen energy industry chain.

[0003] Liquid hydrogen storage tanks are typically double-walled, vacuum-insulated structures, with their core internal space consisting of an upper gas cushion and a lower liquid space. The gas cushion is a specially designed, unoccupied top gas phase region, its importance self-evident. First, it serves as a container for the boil-off gas (BOG), receiving hydrogen that continuously vaporizes due to external heat leakage, preventing a sudden and rapid increase in internal pressure and providing a crucial buffer for pressure control. Second, it allows for thermal expansion and contraction of liquid hydrogen due to changes in ambient temperature, preventing incompressible hydraulic shocks to the tank structure. Third, it is the functional area for pressure monitoring and safety relief devices (such as safety valves and rupture discs), ensuring the inherent safety of the storage tank by maintaining pressure within the design range or releasing pressure in an orderly manner. Finally, during filling and discharging operations, the gas cushion provides a channel for gas intake and exhaust, ensuring smooth process flow. Therefore, the physical and thermodynamic states of the gas cushion (such as pressure, temperature, and gas concentration) directly determine the operational stability, safety, and economy of the storage tank.

[0004] The rigid requirements for pressure relief systems in liquid hydrogen storage tanks stem from the unique physical properties of liquid hydrogen itself and the absolute limitations imposed by practical engineering. Extremely high gas-liquid density ratio and extremely low latent heat of vaporization: Under standard atmospheric pressure, the density of liquid hydrogen is approximately 70.8 kg / m³, while the density of gaseous hydrogen is only about 0.089 kg / m³, resulting in an astonishing gas-liquid volume ratio of 1:795. This means that one unit volume of liquid hydrogen, once completely vaporized, will produce nearly 800 unit volumes of hydrogen gas. Even more critically, liquid hydrogen has an extremely low latent heat of vaporization, only 445 kJ / kg (compared to 2257 kJ / kg for water). This means that only a relatively small amount of heat input is needed to cause a large amount of liquid hydrogen to vaporize. The combination of these two characteristics makes the pressure accumulation within the storage tank exceptionally rapid and intense.

[0005] Although modern liquid hydrogen storage tanks employ advanced insulation technologies such as multi-layered high-vacuum insulation (MLI), the ideal of "absolute zero heat leakage" is impractical in engineering. Ambient heat will continuously seep into the tank at extremely low rates through conduction, radiation, and convection. This heat leakage, absorbed by the liquid hydrogen, becomes the energy source for its continuous vaporization. This process is continuous, whether in static storage (such as on-site tanks) or dynamic transportation (such as liquid hydrogen tank containers). As a pressure vessel, the design, manufacture, and operation of the storage tank must adhere to stringent standards (such as the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPVC)), and its maximum permissible working pressure (MAWP) is an inviolable red line. Once the pressure inside the tank approaches or exceeds the MAWP due to the continuous generation of BOG (Boiler and Pressure Vessel), the structural integrity of the tank will be severely threatened, posing a risk of catastrophic rupture and explosion.

[0006] When the pressure inside the gas pillow of a liquid hydrogen storage tank reaches the maximum permissible working pressure (MAWP), the safety valve must open to release hydrogen gas and reduce the pressure inside the tank. As the pressure inside the tank decreases, the boiling point of liquid hydrogen also decreases, causing depressurization and evaporation of liquid hydrogen inside the tank, which leads to further evaporation of liquid hydrogen. Therefore, how to use a suitable device to reduce the pressure inside the gas pillow of a liquid hydrogen storage tank is of great significance to the safe and economical operation of the liquid hydrogen storage tank. Summary of the Invention

[0007] The purpose of this invention is to overcome at least one technical problem existing in the prior art and to provide an apparatus and method for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank.

[0008] On one hand, embodiments of the present invention provide a device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank. The device is integrated within the gas cushion space of the liquid hydrogen storage tank and is used to actively manage the internal pressure of the liquid hydrogen storage tank. The device includes: an adsorption storage component, a desorption recovery component, and an adsorption enhancement component. The adsorption storage component includes a one-way mechanical cryogenic valve, a vacuum insulation cylinder, and a solid adsorbent material housed inside the vacuum insulation cylinder, all connected sequentially by pipelines. The vacuum insulation cylinder is fixed within the gas cushion of the liquid hydrogen storage tank. The inlet of the one-way mechanical cryogenic valve communicates with the gas cushion space and is configured to automatically open when the pressure within the gas cushion space reaches a preset first threshold, thereby adsorbing and storing hydrogen flowing through the vacuum insulation cylinder using the solid adsorbent material. The preset first threshold is set to 0.5 to 1.0 times the calibrated opening pressure of the safety valve configured in the liquid hydrogen storage tank. The desorption recovery component includes a medium-pressure adsorbent material disposed inside the vacuum insulation cylinder. The system includes an intermediate heater, a room-temperature hydrogen inlet valve connected to the fluid inlet of the intermediate heater, a room-temperature hydrogen exhaust valve connected to the fluid outlet of the intermediate heater, and an adsorbed hydrogen exhaust valve connected to the gas phase space of the vacuum insulation cylinder. The room-temperature hydrogen inlet valve and the room-temperature hydrogen exhaust valve extend to the outside of the liquid hydrogen storage tank. The desorption and recovery assembly is used to desorb the hydrogen adsorbed in the solid adsorbent material via the adsorbed hydrogen exhaust valve. The adsorption enhancement assembly includes a cryogenic hydrogen regulating valve and a cryogenic heat exchanger. The inlet of the cryogenic hydrogen regulating valve is connected to the gas cushion space, and its outlet is connected to the fluid inlet of the cryogenic heat exchanger. The heat exchange part of the cryogenic heat exchanger is placed in the solid adsorbent material to reduce the temperature of the solid adsorbent material. The cryogenic hydrogen regulating valve is configured to automatically open when the pressure in the gas cushion space reaches a preset second threshold. The preset second threshold is 1.03 to 1.05 times the preset first threshold.

[0009] Furthermore, the main body of the liquid hydrogen storage tank includes a liquid hydrogen storage tank shell, a liquid hydrogen storage tank inner liner, a liquid hydrogen storage tank heat insulation support, a liquid hydrogen storage tank cryogenic connector, a liquid inlet cryogenic valve, and a spray inlet pipe. The liquid hydrogen storage tank shell and the liquid hydrogen storage tank inner liner form a sandwich structure and are fixed by the liquid hydrogen storage tank heat insulation support. Multiple layers of heat-insulating and reflective films are installed in the sandwich. The spray inlet pipe is located in the air cushion area at the top of the liquid hydrogen storage tank inner liner, and spray holes are provided on the surface of the pipe. The liquid hydrogen storage tank cryogenic connector is an external interface. One end of the liquid inlet cryogenic valve is connected to an external liquid hydrogen source, and the other end is connected to the spray inlet pipe.

[0010] Furthermore, the outer shell of the liquid hydrogen storage tank and the inner liner of the liquid hydrogen storage tank form a sandwich structure, and the two are fixedly connected by the heat insulation support of the liquid hydrogen storage tank.

[0011] Furthermore, the outer shell, inner liner, spray inlet pipe, and vacuum insulation cylinder of the liquid hydrogen storage tank are all made of stainless steel. The leakage rate of the weld between the outer shell and the inner liner of the liquid hydrogen storage tank does not exceed a preset leakage rate threshold. The preset leakage rate threshold is... The number of multi-layer heat-insulating and reflective films laid in the interlayer shall not be less than 20.

[0012] Furthermore, the safety valve opening pressure is equal to the maximum allowable working pressure of the liquid hydrogen storage tank, and the burst pressure of the rupture membrane is higher than the safety valve opening pressure.

[0013] Furthermore, the solid adsorbent material is one or more of physical adsorbent materials, chemical adsorbent materials, or composite adsorbent materials; the physical adsorbent material is activated carbon or coconut shell porous media, the chemical adsorbent material is magnesium-based, nickel-based, or zirconium-based hydrides, and the composite adsorbent material is a composite material of nano-confined materials and composite hydrides.

[0014] Furthermore, the intermediate heater is composed of multiple metal tubes connected in parallel or series, and the outer surface of the metal tubes is provided with radial fins or spiral fins to increase the heat exchange area.

[0015] Furthermore, the low-temperature heat exchanger is a stainless steel coil with external fins or ribs, and the coil is evenly distributed inside the solid adsorbent material to increase the heat exchange area.

[0016] Secondly, embodiments of the present invention provide a method for reducing exhaust losses using the pressure of a liquid hydrogen storage tank. This method is applied to the aforementioned apparatus for reducing exhaust losses using the pressure of a liquid hydrogen storage tank. The method includes: an adsorption storage step: when the pressure inside the gas pillow of the liquid hydrogen storage tank reaches the opening pressure of the one-way mechanical cryogenic valve due to the accumulation of evaporated gas, the one-way mechanical cryogenic valve is opened, allowing the evaporated gas to enter the vacuum insulation cylinder and be adsorbed by the solid adsorbent material, thereby reducing the internal pressure of the liquid hydrogen storage tank; and an adsorption enhancement step: when the adsorption capacity of the solid adsorbent material decreases due to temperature increase or approaching saturation, leading to a decrease in the internal pressure of the liquid hydrogen storage tank... When the pressure reaches the preset second threshold, the cryogenic hydrogen regulating valve is opened, allowing the high-pressure hydrogen in the liquid hydrogen storage tank to flow through the cryogenic hydrogen regulating valve and generate a throttling cooling effect. The generated cryogenic fluid flows through the cryogenic heat exchanger, thereby actively cooling the solid adsorbent material and increasing its adsorption capacity. Desorption and recovery step: When hydrogen needs to be supplied externally, external ambient temperature high-pressure hydrogen enters the intermediate heater through the ambient temperature hydrogen inlet valve and then leaves the intermediate heater through the ambient temperature hydrogen exhaust valve. After being heated, the intermediate heater raises the temperature of the solid adsorbent material, causing the adsorbed hydrogen to be discharged through the adsorbed hydrogen exhaust valve, restoring the hydrogen adsorption capacity of the solid adsorbent material for use in the next cycle.

[0017] In another aspect, the present invention also provides a computer-readable storage medium storing one or more instructions for causing a computer to perform the above-described method for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank.

[0018] In another aspect, the present invention provides an electronic device, comprising: a memory and a processor; the memory storing at least one program instruction; the processor loading and executing the at least one program instruction to implement the above-described method for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. Active pressure management: It transforms passive venting into active adsorption storage, significantly extending the safety valve opening interval and improving the static preservation capacity of the storage tank.

[0021] 2. Hydrogen recovery and utilization: Converting the vaporized gas that would otherwise have to be emitted into a recyclable resource effectively improves economic performance.

[0022] 3. Internal energy circulation: The innovative adsorption enhancement component utilizes the device's own pressure potential energy to improve performance, relying little or no on external energy sources, thus effectively improving energy efficiency.

[0023] 4. Safe and reliable: The vacuum insulation design solves the core problem of adsorption heat management and is connected in parallel with the original safety relief device to form a double guarantee.

[0024] 5. High integration: The main components of the device are integrated into the air cushion, requiring minimal modification to the existing storage tank structure, making it easy to implement and promote. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a schematic diagram of a device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank, provided in Embodiment 1 of the present invention.

[0027] Figure 2 This is a schematic diagram of the working principle of a device that uses the pressure of a liquid hydrogen storage tank to reduce exhaust loss, provided in Embodiment 1 of the present invention.

[0028] Figure 3 This is a comparison diagram of the trajectory of internal pressure change over time in a liquid hydrogen storage tank, which is provided in Embodiment 1 of the present invention and employs existing technology and the technology disclosed in this embodiment.

[0029] Figure 4 This is a flowchart of a method for reducing exhaust loss by utilizing the pressure of a liquid hydrogen storage tank, provided in Embodiment 2 of the present invention.

[0030] Figure 5 This is a partial block diagram of the electronic device provided in Embodiment 4 of the present invention.

[0031] The attached figures are labeled as follows:

[0032] 1—Liquid hydrogen storage tank outer shell; 2—Liquid hydrogen storage tank inner liner; 3—Liquid hydrogen storage tank thermal insulation support; 4—Liquid hydrogen storage tank cryogenic connector; 5—Liquid hydrogen inlet cryogenic valve; 6—Spray inlet pipe; 7—One-way mechanical cryogenic valve; 8—Solid adsorbent material; 9—Vacuum insulation cylinder; 10—Intermediate heater; 11—Breakout membrane; 12—Safety valve; 13—Ambient temperature hydrogen inlet valve; 14—Ambient temperature hydrogen exhaust valve; 15—Cryogenic hydrogen regulating valve; 16—Cryogenic heat exchanger; 17—Adsorbed hydrogen exhaust valve. Detailed Implementation

[0033] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0034] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] The present invention will now be described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0036] Example 1

[0037] For ease of understanding, the overall inventive concept of this invention is explained here. This invention provides a device and method for reducing exhaust losses using the pressure of a liquid hydrogen storage tank, including an adsorption storage component, a desorption recovery component, and an adsorption enhancement component. The adsorption storage component is the core of the device, and it is connected to the tank's gas pillow via a one-way mechanical cryogenic valve with a preset opening pressure. When the tank pressure rises to this threshold due to the accumulation of evaporated gas, the valve opens, and hydrogen enters a vacuum-insulated cylinder, where it is adsorbed and stored by the solid adsorbent material. The vacuum-insulated cylinder is used to isolate the heat released during the adsorption process, preventing it from entering the liquid hydrogen bulk and causing further evaporation. The adsorption enhancement component is the core of this invention. It includes a cryogenic hydrogen regulating valve and a cryogenic heat exchanger placed within the adsorbent material. When the performance of the adsorbent material decreases due to temperature rise or saturation, the regulating valve can be opened to throttle and cool the high-pressure hydrogen in the tank. The resulting cold fluid flows through the cryogenic heat exchanger, thereby actively cooling the adsorbent material, significantly increasing its adsorption capacity, and achieving self-enhancing of system performance. The desorption recovery component is used for hydrogen recovery. It uses a built-in intermediate heater to heat the adsorbent material when heated gas is introduced, causing it to release the stored hydrogen gas, which is then discharged through a special exhaust valve for use.

[0038] The specific implementation method is as follows:

[0039] like Figure 1 The diagram shown is a structural schematic of a device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank, provided by the present invention.

[0040] As an example, the device is integrated into the gas cushion space of a liquid hydrogen storage tank for actively managing the internal pressure of the liquid hydrogen storage tank. The device includes: an adsorption storage component, a desorption recovery component, and an adsorption enhancement component. The adsorption storage component includes a one-way mechanical cryogenic valve 7, a vacuum insulation cylinder 9, and a solid adsorbent material 8 housed inside the vacuum insulation cylinder 9, all connected sequentially by pipelines. The vacuum insulation cylinder 9 is fixed inside the gas cushion of the liquid hydrogen storage tank. The inlet of the one-way mechanical cryogenic valve 7 is connected to the gas cushion space and is configured to automatically open when the pressure in the gas cushion space reaches a preset first threshold, thereby adsorbing and storing hydrogen flowing through the vacuum insulation cylinder 9 through the solid adsorbent material 8. The desorption recovery component includes an intermediate heater 10 disposed inside the vacuum insulation cylinder 9, a room-temperature hydrogen inlet valve 13 connected to the fluid inlet of the intermediate heater 10, and a room-temperature hydrogen outlet valve connected to the fluid outlet of the intermediate heater 10. The gas valve 14 and the hydrogen adsorption exhaust valve 17 connected to the gas phase space of the vacuum insulation cylinder 9 are included. The ambient temperature hydrogen inlet valve 13 and the ambient temperature hydrogen exhaust valve 14 extend to the outside of the liquid hydrogen storage tank. The desorption and recovery assembly is used to desorb the hydrogen adsorbed in the solid adsorbent material 8 via the hydrogen adsorption exhaust valve 17. The adsorption enhancement assembly includes a cryogenic hydrogen regulating valve 15 and a cryogenic heat exchanger 16. The inlet of the cryogenic hydrogen regulating valve 15 is connected to the gas cushion space, and its outlet is connected to the fluid inlet of the cryogenic heat exchanger 16. The heat exchange part of the cryogenic heat exchanger 16 is placed in the solid adsorbent material 8 to reduce the temperature of the solid adsorbent material 8. The cryogenic hydrogen regulating valve 15 is configured to automatically open when the pressure in the gas cushion space reaches a preset second threshold. The preset second threshold is 1.03 to 1.05 times the preset first threshold, that is, the preset second threshold is slightly larger than the preset first threshold.

[0041] In some feasible embodiments, the liquid hydrogen storage tank body includes a liquid hydrogen storage tank shell 1, a liquid hydrogen storage tank inner liner 2, a liquid hydrogen storage tank heat insulation support 3, a liquid hydrogen storage tank cryogenic connector 4, a liquid inlet cryogenic valve 5, and a spray inlet pipe 6. The liquid hydrogen storage tank shell 1 and the liquid hydrogen storage tank inner liner 2 form a sandwich structure and are fixed by the liquid hydrogen storage tank heat insulation support 3. Multiple layers of heat-insulating and reflective films are provided in the sandwich. The spray inlet pipe 6 is located in the air cushion area at the top of the liquid hydrogen storage tank inner liner 2, and the surface of the pipe is provided with spray holes. The liquid hydrogen storage tank cryogenic connector 4 is an external interface. One end of the liquid inlet cryogenic valve 5 is connected to an external liquid hydrogen source, and the other end is connected to the spray inlet pipe 6.

[0042] Preferably, the outer shell 1, inner liner 2, spray inlet pipe 6, and vacuum insulation cylinder 9 of the liquid hydrogen storage tank are all made of stainless steel. The leakage rate of the weld between the outer shell 1 and the inner liner 2 of the liquid hydrogen storage tank is not higher than a preset leakage rate threshold (e.g., 1.0E-9Pa·m³ / s). The number of multi-layer heat-insulating reflective films laid in the interlayer is not less than N layers (e.g., 20 layers).

[0043] Specifically, the outer shell 1 and the inner liner 2 of the liquid hydrogen storage tank are made of 304N or 316L stainless steel and welded together. The inner and outer surfaces of the inner liner 2 should be clean and smooth, as should the inner surface of the outer shell 1, to reduce radiative heat leakage. The interlayer formed by the outer shell 1 and the inner liner 2 should be fully sealed, and the weld leakage rate should not exceed [percentage missing]. The interlayer should use no less than 20 layers of MLI multilayer heat-reflective insulating film to reduce heat leakage caused by thermal radiation. The liquid hydrogen storage tank insulation support 3 should adopt a design to reduce heat leakage, by lengthening the entire support structure or using non-metallic materials at the base. Where mechanically permissible, non-metallic materials such as polyimide (PI) or carbon fiber should be used as the main structural material for the support. The liquid hydrogen storage tank cryogenic connector 4 should use a double-layer vacuum insulation connector to effectively reduce heat leakage at the interface when liquid hydrogen is unloaded through the pipeline, preventing liquid hydrogen vaporization. The inlet cryogenic valve 5 should use a vacuum jacket or a type with a built-in vacuum jacket to reduce heat leakage and minimize liquid hydrogen vaporization. The spray inlet pipe 6 should use a 304N or 316L stainless steel round pipe with spray holes arranged on the pipe surface to ensure uniform flow of liquid hydrogen along the pipe direction. The vacuum insulation cylinder 9 is made of 304N or 316L stainless steel. Vacuum insulation measures are adopted between the inner and outer layers to isolate the heat released when the solid adsorbent material 8 absorbs hydrogen. The middle layer should be wrapped with multiple layers of heat-insulating emission film to reduce the heat leakage rate.

[0044] In some feasible embodiments, the liquid hydrogen storage tank body also includes a safety protection component, which includes a rupture membrane 11 and a safety valve 12. The safety valve 12 and the rupture membrane 11 are connected in parallel in the top pipeline of the liquid hydrogen storage tank. The opening pressure of the safety valve is equal to the maximum allowable working pressure of the liquid hydrogen storage tank, and the rupture pressure of the rupture membrane 11 is higher than the opening pressure of the safety valve 12. The working process includes: the liquid hydrogen stored in the liquid hydrogen storage tank for a long time begins to vaporize due to external heat leakage, and the pressure in the gas pillow inside the tank gradually increases. When the pressure in the gas pillow reaches the opening pressure of the one-way mechanical cryogenic valve 7, the one-way mechanical cryogenic valve 7 opens, and the hydrogen in the gas pillow enters the vacuum insulation cylinder 9, where it is adsorbed and stored by the solid adsorbent material 8. At this time, the pressure in the vacuum insulation cylinder 9 does not reach the opening pressure of the safety valve 12. If the liquid hydrogen storage tank is in a malfunction or accident state, the solid adsorbent material 8 cannot adsorb the evaporated hydrogen in time. In this case, the rupture membrane 11 and the safety valve 12 should operate according to normal logic to protect the safety of the liquid hydrogen storage tank.

[0045] In some feasible implementations, the preset first threshold of the one-way mechanical cryogenic valve 7 is set to 0.5 to 1.0 times the calibrated opening pressure of the safety valve 12 configured on the liquid hydrogen storage tank.

[0046] In some feasible embodiments, the solid adsorbent material 8 is one or more of physical adsorbent materials, chemical adsorbent materials, or composite adsorbent materials; the physical adsorbent material is activated carbon or coconut shell porous media, the chemical adsorbent material is magnesium-based, nickel-based, or zirconium-based hydride, and the composite adsorbent material is a nano-confined material or a modified two-dimensional material.

[0047] Preferably, solid-state hydrogen storage materials primarily store hydrogen molecules or atoms in the interstitial spaces or structure of the material through physical adsorption or chemical bonding with hydrogen gas. Physically adsorbed materials exhibit rapid hydrogen adsorption and desorption rates and good reversibility, but typically require extremely low temperatures (e.g., 77K, -196°C) to achieve significant hydrogen storage capacity; their capacity is very low at room temperature. Chemically adsorbed hydrides form compounds with hydrogen through chemical bonds, and the hydrogen adsorption and desorption process involves the breaking and formation of these bonds. Metal hydrides are the most mature and widely used type, while composite hydrides and other emerging materials (between physical and chemical adsorption) also exist. For example, filling the nanopores of nanoconfined materials (such as carbon aerogels) with composite hydrides can significantly improve their kinetic properties and reversibility. Furthermore, two-dimensional materials such as graphene and boron nitride can also be used as modifiers to enhance adsorption performance. When graphene or boron nitride is used as a composite adsorbent material, it can achieve synergistic effects of physical and chemical adsorption by introducing active functional groups or constructing composite pore structures through surface modification. Graphene can form oxygen-containing functional groups through oxidation modification, while boron nitride can optimize adsorption sites by doping with metal ions. Both can improve hydrogen storage capacity and stability.

[0048] Furthermore, the hydrogen storage capacity of solid-state hydrogen storage materials is significantly related to their temperature. As the system temperature gradually decreases, the thermal kinetic energy of hydrogen molecules decreases significantly, their diffusion becomes slower, and they are more easily captured by the material's porous structure and surface sites, thus tightly adsorbing onto the material's inner and outer surfaces. Therefore, both the gravimetric and volumetric hydrogen storage capacities of the material exhibit a monotonically increasing trend with decreasing temperature. It is particularly noteworthy that when the temperature drops to an extremely low 20K (approximately -253°C), close to the storage temperature of liquid hydrogen, the material's hydrogen storage capacity reaches its peak. Under these ultra-low temperature conditions, hydrogen molecules almost completely lose their thermal kinetic energy, physical adsorption reaches its strongest point, and the amount of hydrogen that the material can adsorb approaches its theoretical limit. Its hydrogen storage density can even rival that of liquid hydrogen, while avoiding the high pressure and continuous evaporation losses necessary for liquid hydrogen storage, demonstrating extremely high application potential. The dependence of hydrogen storage capacity (n, usually expressed as mass percentage wt% or moles) on temperature (T) and pressure (P) can be described by isothermal adsorption models, the most classic of which is the Langmuir model:

[0049] n = n_max × (b × P) / (1 + b × P); where n_max represents the maximum saturated hydrogen storage capacity of the material at that temperature, and b is the Langmuir constant, a parameter closely related to the heat of adsorption and temperature, with the relationship being b ∝ exp(-ΔH_ads / (RT)), where ΔH_ads is the heat of adsorption (a negative value), and R is the ideal gas constant. From this formula, it is clear that the lower the temperature T, the larger the value of the Langmuir constant b, which means that under the same pressure, the hydrogen storage capacity n of the material is higher. A typical hydrogen storage capacity-temperature relationship curve (at a fixed pressure) shows a curve that rises sharply as the temperature decreases. In the range from room temperature to liquid nitrogen temperature (77 K), the curve slope is large, and the hydrogen storage capacity increases significantly; when the temperature further decreases from 77 K to 20 K, the curve continues to climb and reaches its peak near 20 K. The hydrogen gas produced by heat leakage and evaporation inside the liquid hydrogen storage tank is low in temperature and high in pressure. If the pressure potential energy of the low-temperature hydrogen gas is directly discharged, it cannot be recovered and utilized, resulting in increased overall tank wear. If only throttling is used, the hydrogen gas cannot return to the tank due to the reduced pressure after throttling. However, if the hydrogen gas with a lower temperature after throttling is used to cool the solid hydrogen storage material, the adsorption capacity of the hydrogen storage material can be further increased, delaying the next discharge of low-temperature hydrogen gas due to the increased hydrogen pressure inside the tank, thereby reducing the wear and tear on the liquid hydrogen storage tank.

[0050] In some feasible embodiments, the intermediate heater 10 is composed of multiple metal tubes connected in parallel or in series, and the outer surface of the metal tubes is provided with radial fins or spiral fins to increase the heat exchange area.

[0051] In some feasible implementations, the low-temperature heat exchanger 16 is a stainless steel coil with external fins or ribs, and the coil is evenly distributed inside the solid adsorbent material 8 to increase the heat exchange area.

[0052] In some feasible ways, combine Figure 2 As shown, the working principle of this device is as follows: Liquid hydrogen is injected into the storage tank through the inlet cryogenic valve 5 and the spray inlet pipe 6. At this time, the pressure inside the tank is lower than the opening pressure of the one-way mechanical cryogenic valve 7, so the valve is closed, the adsorption system is on standby, and the vacuum insulation cylinder 9 maintains an insulated state. During the adsorption depressurization stage: External heat penetration causes liquid hydrogen to evaporate, increasing the amount of BOG in the gas pillow and raising the tank pressure. When the tank pressure reaches the opening pressure of the one-way mechanical cryogenic valve 7, the valve opens, and BOG enters the vacuum insulation cylinder 9 and is adsorbed by the solid adsorbent material 8, causing the tank pressure to drop and delaying the exhaust from the safety valve 12. During the enhanced adsorption stage: After the adsorbent material releases heat, its adsorption capacity decreases, and the tank pressure rises again. The cryogenic hydrogen regulating valve 15 is opened, and the high-pressure hydrogen is throttled and cooled. After passing through the cryogenic heat exchanger 16, the adsorbent material's adsorption capacity increases, continuing to adsorb BOG and further extending the exhaust interval. Desorption and regeneration stage: When the storage tank is unloaded or the adsorbent material is saturated, open the ambient temperature hydrogen inlet valve 13 and the ambient temperature hydrogen exhaust valve 14, and the ambient temperature hydrogen heats the intermediate heater 10, the adsorbent material is heated, the hydrogen is desorbed and recovered through the adsorbent hydrogen exhaust valve 17, and the material restores its adsorption capacity.

[0053] Preferably, the desorption and recovery assembly operates as follows: First, ensure the one-way mechanical cryogenic valve 7 is closed, disconnect the adsorption storage assembly from the main storage tank's gas pillow to prevent the desorbed hydrogen from flowing back. Connect the inlet of the ambient temperature hydrogen inlet valve 13 to an external heat source (such as an electric heater or a warm gas flow from another process). Connect the outlet of the adsorbed hydrogen exhaust valve 17 to a hydrogen compression system, purification system, or directly to a pipeline network. Introduce the heat source: Open the ambient temperature hydrogen inlet valve 13, and a heated, dry inert gas (such as nitrogen) or circulating hydrogen (typically at 40°C-150°C, depending on the characteristics of the adsorbent material) is introduced. The hot gas flow passes through the intermediate heater 10 located inside the adsorbent material and exits via the ambient temperature hydrogen exhaust valve 14. This heater 10 is typically composed of finned stainless steel tubing to maximize the heat exchange area. At this point, the temperature of the solid adsorbent material 8 rises. According to the isothermal adsorption curve of the adsorbent material (the higher the temperature, the higher the equilibrium pressure), the increase in temperature will drastically reduce the material's adsorption capacity for hydrogen, disrupting the original adsorption equilibrium. The hydrogen desorbed from the adsorbent material, due to its increased partial pressure, will collect in the gas phase space of the vacuum insulated cylinder 9 and be discharged through the opened hydrogen adsorption exhaust valve 17.

[0054] Preferably, the working process of the adsorption enhancement component is as follows: High-pressure, low-temperature hydrogen flows through the low-temperature hydrogen regulating valve 15 (a throttling valve) in the liquid hydrogen storage tank's gas pillow, causing a Joule-Thomson effect and a sharp drop in gas pressure and temperature. This generates an ultra-low temperature, low-pressure hydrogen flow. The regulating valve acts as a "refrigeration unit." The ultra-low-temperature hydrogen generated from the regulating valve flows into the low-temperature heat exchanger 16 (which can be understood as a coil) embedded in the adsorbent material. The heat exchanger acts like an "evaporator in a refrigerator," exchanging heat with the adsorbent material through the tube wall, efficiently absorbing heat from the adsorbent material and lowering its temperature. The final effect: After cooling, the equilibrium adsorption capacity of the adsorbent material is significantly increased. This means that material that might have been close to saturation can absorb even more hydrogen. Therefore, this component does not consume external electrical energy but utilizes the inherent, soon-to-be-wasted (high-pressure BOG) energy within the system to address the system's own problems (adsorbent performance degradation). It allows the system to actively intervene, regulate, and optimize the working state of the adsorbent material, rather than passively relying on its initial performance. When the tank pressure is detected to rise slowly again due to the decline in adsorbent performance, this component can be activated to perform a "performance enhancement", thereby further delaying the venting time and achieving long-term and refined control of the tank pressure.

[0055] In some feasible implementations, to facilitate understanding of the above embodiments, specific application examples are provided here: Taking a hydrogen refueling station liquid hydrogen storage system as an example, the scenario is as follows: A hydrogen refueling station in a certain city is equipped with a 50-cubic-meter vertical vacuum-insulated liquid hydrogen storage tank for storing and supplying fuel hydrogen. During static storage (especially during off-peak hours at night), the tank continuously generates boil-off gas (BOG) due to external heat leakage. Under traditional solutions, when the pressure inside the tank rises to the set value of safety valve 12, hydrogen will be discharged into the atmosphere, resulting in a loss of approximately 5-7 kg of hydrogen per day, which is both wasteful and unsafe. This station has installed a device described in this invention. The key parameters of the device are set as follows: Liquid hydrogen storage tank: Maximum allowable working pressure (MAWP): 1.5 MPa; Safety valve 12 opening pressure: 1.38 MPa; Normal working pressure range: 0.1-1.2 MPa; Core parameters of the device of this invention: One-way mechanical cryogenic valve 7 opening pressure: set to 1.1 MPa (approximately 0.8 times the opening pressure of safety valve 12). The vacuum insulated cylinder 9 has a volume of 2 cubic meters; the solid adsorbent 8 is a high-performance metal-organic framework (MOF-310), which has a theoretical hydrogen storage density of 80 g / L (material volume) at 20 K and 1.1 MPa pressure. The adsorption enhancement component trigger pressure is 1.15 MPa (set by the control system, slightly higher than the one-way valve opening pressure (1.1 MPa) for early intervention). That is, when the pressure rises to the first threshold (1.1 MPa), adsorption storage begins; if the adsorbent performance deteriorates, causing the pressure to rise again to a higher second threshold (1.15 MPa), the adsorption enhancement component will then activate cooling to restore adsorption capacity. This logic avoids process chaos and hydrogen waste.

[0056] The workflow record is as follows:

[0057] Phase 1: Normal Storage and Initial Adsorption (Day 1 08:00 - Day 2 14:00): After adding liquid hydrogen in the morning, the tank pressure was 0.5 MPa. As ambient heat seeped in, the liquid hydrogen slowly evaporated, and the tank pressure gradually increased. At 14:00 on the second day, the tank pressure reached 1.1 MPa. The one-way mechanical cryogenic valve 7 was opened by the pressure. The low-temperature, high-pressure hydrogen in the gas pillow began to enter the vacuum insulation cylinder 9 and was adsorbed by the MOF material. The heat released during the adsorption process was effectively isolated by the vacuum insulation cylinder 9. Over the next 4 hours, the tank pressure steadily decreased from 1.1 MPa to 0.95 MPa. The one-way valve automatically closed. During this phase, the system successfully avoided the venting of safety valve 12, which had been triggered on the first night, and recovered approximately 3 kg of hydrogen.

[0058] Phase Two: Adsorption Enhancement and Performance Recovery (Day 3, 10:00 AM): After several rounds of adsorption, the adsorbent temperature rose from 20K to 25K, and the adsorption capacity decreased by approximately 30%. The tank pressure rose again due to BOG accumulation, reaching 1.15MPa (the adsorption enhancement trigger point), automatically opening the cryogenic hydrogen regulating valve 15. Hydrogen gas at 1.15MPa and 25K, after passing through the throttling valve, experienced a sudden pressure drop to 0.2MPa and a temperature drop to 18K. This ultra-low temperature hydrogen flowed into the cryogenic heat exchanger 16, acting like a built-in refrigerator, forcibly cooling the MOF material. After approximately one hour of cooling, the core temperature of the adsorbent was cooled to 19K, and its adsorption capacity recovered to over 95% of its initial level. The tank pressure dropped back to 0.98MPa. In this phase, without emitting any hydrogen gas or consuming external electrical energy, the exhaust was further delayed solely by utilizing the pressure energy of the device itself.

[0059] Phase 3: Desorption and Hydrogen Utilization (Day 4, 08:00, Morning Rush Hour Hydrogen Refueling): With the morning rush hour approaching, the station requires a large amount of hydrogen, and the adsorption system is nearing its design capacity. The operator initiates the desorption procedure. The ambient temperature hydrogen inlet valve 13 is opened, introducing 40°C circulating hydrogen from the station's buffer tank; simultaneously, the adsorption hydrogen exhaust valve 17 is opened, connecting to the station's compressor inlet. The 40°C hydrogen flows through the intermediate heater 10, transferring heat to the MOF material via convection. The material temperature rises above -100°C, and a large amount of hydrogen is rapidly desorbed. Within 2 hours, the system successfully desorbs approximately 120 kg of high-purity hydrogen, which is then pressurized for vehicle refueling. After desorption is complete, the valves are closed, and the system returns to standby mode, preparing for the next adsorption cycle.

[0060] More specifically, in order to intuitively demonstrate the superiority of the device disclosed in this invention compared to the prior art, combined with Figure 3 As shown, the trajectory of the internal pressure of the liquid hydrogen storage tank over time is clearly simulated under two schemes (the prior art has no device to reduce exhaust loss by utilizing the pressure of the liquid hydrogen storage tank and the present invention has a device to reduce exhaust loss by utilizing the pressure of the liquid hydrogen storage tank): the horizontal axis is time and the vertical axis is the pressure inside the storage tank. The two curves correspond to: without the device (prior art): the opening pressure of safety valve 12 is reached earlier; with the device (the present invention): the time to reach the opening pressure of safety valve 12 is significantly extended.

[0061] Based on the above embodiments, the beneficial effects of the present invention are specifically reflected in the following aspects: Firstly, compared to the traditional mode: pressure rise → safety valve 12 opens → emergency venting, which is a passive, reactive safety measure, the present invention's mode: pressure rises → adsorption system starts → pressure actively decreases → venting is avoided. This is an active, preventative pressure control strategy. It significantly advances the safety management node, greatly reducing the frequency and demand for safety valve 12 operation. Secondly, the adsorption system of the present invention, in parallel with the original safety valve 12 and rupture membrane, constitutes a double or multiple safety barrier. Even if the adsorption system fails for any reason (such as adsorption saturation), the traditional safety relief device still works normally, ensuring the ultimate safety of the storage tank. This design improves the safety margin and reliability of the entire storage tank system. Thirdly, the present invention, through the design of a vacuum insulation cylinder, perfectly solves the fatal threat of exothermic reaction of the solid adsorption material 8 to liquid hydrogen storage, transforming the adsorption process from a potential "risk source" into a controllable "solution." This is the core guarantee for the safe operation of the system. On the one hand, this invention recycles the previously wasted boil-off gas (BOG) on a large scale and with high efficiency, converting it into high-purity hydrogen products that can be sold or used internally, effectively increasing revenue. On the other hand, for scenarios such as strategic reserves, long-distance transportation (e.g., liquid hydrogen shipping), and hydrogen refueling station reserves, this invention can extend the safe storage time of liquid hydrogen storage tanks without venting by several times or even tens of times. This reduces the need for forced transfer, unloading, or use operations due to pressure increases, lowering operational complexity and costs, and enabling flexible dispatching and ocean transportation of hydrogen energy. The adsorption enhancement component utilizes the device's own pressure potential energy for cooling, consuming little or no external electrical / energy, achieving a "near-zero cost" performance improvement. Compared to traditional BOG reliquefaction or external cooling solutions, its operating cost is negligible, and its energy efficiency is extremely high. Furthermore, this invention creatively converts the pressure energy of high-pressure BOG (the "waste energy") into cooling energy through a throttling effect, which is used to improve the performance of the adsorption material. Furthermore, this invention not only utilizes materials but also actively manages their performance status: Normal adsorption: maximizing their basic storage function; Active cooling: when their performance degrades, the adsorption enhancement system "recharges" them, restoring their adsorption capacity; Controllable desorption: when needed, hydrogen can be rapidly released on command. This management strategy maximizes the utilization efficiency of the adsorbent material and extends its lifespan. Moreover, the device is primarily integrated into the gas cushion space inside the storage tank, requiring minimal modification to the external structure and main interfaces of existing tanks. This makes the technology applicable to both new storage tanks and relatively easy to upgrade existing ones, resulting in strong feasibility for widespread adoption.

[0062] Example 2

[0063] Please see Figure 4This embodiment provides a flowchart of a method for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank.

[0064] As an example, the method is applied to the apparatus described in Example 1 for reducing exhaust losses using the pressure of a liquid hydrogen storage tank, and the method includes:

[0065] Adsorption storage step: When the pressure inside the liquid hydrogen storage tank's gas pillow reaches the opening pressure of the one-way mechanical cryogenic valve 7 due to the accumulation of evaporated gas, the one-way mechanical cryogenic valve 7 is opened, allowing the evaporated gas to enter the vacuum insulation cylinder 9 and be adsorbed by the solid adsorption material 8, thereby reducing the internal pressure of the liquid hydrogen storage tank.

[0066] Adsorption enhancement step: When the adsorption capacity of the solid adsorbent material 8 decreases due to temperature rise or saturation, causing the internal pressure of the liquid hydrogen storage tank to reach the preset second threshold, the cryogenic hydrogen regulating valve 15 is opened, allowing the high-pressure hydrogen in the liquid hydrogen storage tank to flow through the valve and generate a throttling cooling effect. The generated cryogenic fluid flows through the cryogenic heat exchanger 16, thereby actively cooling the solid adsorbent material 8 and increasing its adsorption capacity.

[0067] Desorption and recovery steps: When hydrogen needs to be supplied externally, the external ambient temperature high pressure hydrogen enters the intermediate heater 10 through the ambient temperature hydrogen inlet valve 13, and then leaves the intermediate heater 10 through the ambient temperature hydrogen exhaust valve 14. After the intermediate heater 10 is heated, the solid adsorbent material 8 is heated, which causes the adsorbed hydrogen to be discharged through the adsorbed hydrogen exhaust valve 17, restoring the hydrogen adsorption capacity of the solid adsorbent material 8 for use in the next cycle.

[0068] It is not difficult to see that this embodiment is a method embodiment corresponding to the first embodiment, and this embodiment can be implemented in conjunction with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the first embodiment.

[0069] Example 3

[0070] This invention also proposes a storage medium storing a method for reducing exhaust losses using liquid hydrogen tank pressure. When executed by a processor, the program for reducing exhaust losses using liquid hydrogen tank pressure implements the steps of the method described above. Since this storage medium employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0071] Example 4

[0072] Please see Figure 5 The present invention also provides an electronic device, including: a memory and a processor; the memory stores at least one program instruction; the processor loads and executes the at least one program instruction to implement the method provided in Embodiment 2 for reducing exhaust loss by utilizing the pressure of a liquid hydrogen storage tank.

[0073] The memory 702 and processor 701 are connected via a bus. This bus can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors 701 and memory 702. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be further described in this embodiment. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 701 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 701.

[0074] Processor 701 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 702 can be used to store data used by processor 701 during operation.

[0075] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank, characterized in that, The device is integrated into the gas cushion space of the liquid hydrogen storage tank and is used to actively manage the internal pressure of the liquid hydrogen storage tank. The device includes: an adsorption storage component, a desorption recovery component, and an adsorption enhancement component. The adsorption storage assembly includes a one-way mechanical cryogenic valve (7), a vacuum insulation cylinder (9), and a solid adsorbent material (8) housed inside the vacuum insulation cylinder (9) connected sequentially by pipelines. The vacuum insulation cylinder (9) is fixed inside the gas pillow of the liquid hydrogen storage tank. The inlet of the one-way mechanical cryogenic valve (7) is connected to the gas pillow space. It is configured to automatically open when the pressure in the gas pillow space reaches a preset first threshold, and to adsorb and store the hydrogen flowing through the vacuum insulation cylinder (9) through the solid adsorbent material (8). The preset first threshold is set to 0.5 to 1.0 times the calibrated opening pressure of the safety valve (12) configured in the liquid hydrogen storage tank. The desorption and recovery assembly includes an intermediate heater (10) disposed inside the vacuum insulation cylinder (9), a room temperature hydrogen inlet valve (13) connected to the fluid inlet of the intermediate heater (10), a room temperature hydrogen exhaust valve (14) connected to the fluid outlet of the intermediate heater (10), and an adsorbed hydrogen exhaust valve (17) connected to the gas phase space of the vacuum insulation cylinder (9). The room temperature hydrogen inlet valve (13) and the room temperature hydrogen exhaust valve (14) extend to the outside of the liquid hydrogen storage tank. The desorption and recovery assembly is used to desorb the hydrogen adsorbed in the solid adsorbent material (8) via the adsorbed hydrogen exhaust valve (17). The adsorption enhancement component includes a cryogenic hydrogen regulating valve (15) and a cryogenic heat exchanger (16). The cryogenic hydrogen regulating valve (15) is a throttling valve, with its inlet connected to the air cushion space and its outlet connected to the fluid inlet of the cryogenic heat exchanger (16). The heat exchange portion of the cryogenic heat exchanger (16) is placed in the solid adsorbent material (8) to reduce the temperature of the solid adsorbent material (8). The cryogenic hydrogen regulating valve (15) is configured to automatically open when the pressure in the air cushion space reaches a preset second threshold. The preset second threshold is 1.03 to 1.05 times the preset first threshold.

2. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 1, characterized in that, The liquid hydrogen storage tank includes a liquid hydrogen storage tank shell (1), a liquid hydrogen storage tank liner (2), a liquid hydrogen storage tank heat insulation support (3), a liquid hydrogen storage tank cryogenic connector (4), a liquid inlet cryogenic valve (5), and a spray inlet pipe (6). The liquid hydrogen storage tank shell (1) and the liquid hydrogen storage tank liner (2) form a sandwich structure, which is fixedly connected by the liquid hydrogen storage tank heat insulation support (3). Multiple layers of heat-insulating and reflective films are provided in the sandwich. The spray inlet pipe (6) is placed in the air cushion area at the top of the liquid hydrogen storage tank liner (2). Spray holes are provided on the surface of the pipe. The liquid hydrogen storage tank cryogenic connector (4) is an external interface. One end of the liquid inlet cryogenic valve (5) is connected to an external liquid hydrogen source, and the other end is connected to the spray inlet pipe (6).

3. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 2, characterized in that, The outer shell (1), inner liner (2), spray inlet pipe (6), and vacuum insulation cylinder (9) of the liquid hydrogen storage tank are all made of stainless steel. The leakage rate of the weld between the outer shell (1) and the inner liner (2) of the liquid hydrogen storage tank is not higher than a preset leakage rate threshold. The preset leakage rate threshold is... The number of multi-layer heat-insulating and reflective films laid in the interlayer shall not be less than 20.

4. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 2, characterized in that, The liquid hydrogen storage tank also includes a rupture membrane (11) and a safety valve (12). The safety valve (12) and the rupture membrane (11) are connected in parallel in the pipeline at the top of the liquid hydrogen storage tank. The opening pressure of the safety valve (12) is equal to the maximum allowable working pressure of the liquid hydrogen storage tank. The bursting pressure of the rupture membrane (11) is higher than the opening pressure of the safety valve (12).

5. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 1, characterized in that, The solid adsorbent (8) is one or more of the following: physical adsorbent, chemical adsorbent, or composite adsorbent; the physical adsorbent is activated carbon, the chemical adsorbent is magnesium-based, nickel-based, or zirconium-based hydride, and the composite adsorbent is a composite material of nano-confined material and composite hydride.

6. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 1, characterized in that, The intermediate heater (10) is composed of multiple metal tubes connected in parallel or in series, and the outer surface of the metal tubes is provided with radial fins or spiral fins to increase the heat exchange area.

7. The device for reducing exhaust losses by utilizing the pressure of a liquid hydrogen storage tank according to claim 1, characterized in that, The low-temperature heat exchanger (16) is a stainless steel coil with external fins or ribs, and the coil is evenly distributed inside the solid adsorbent material (8) to increase the heat exchange area.

8. A method for reducing exhaust losses using liquid hydrogen storage tank pressure, said method being applied to the apparatus for reducing exhaust losses using liquid hydrogen storage tank pressure as described in any one of claims 1-7, characterized in that, The method includes: Adsorption storage step: When the pressure inside the liquid hydrogen storage tank's gas pillow reaches the opening pressure of the one-way mechanical cryogenic valve (7) due to the accumulation of evaporated gas, the one-way mechanical cryogenic valve (7) is opened, allowing the evaporated gas to enter the vacuum insulation cylinder (9) and be adsorbed by the solid adsorbent material (8), thereby reducing the internal pressure of the liquid hydrogen storage tank. Adsorption enhancement step: When the adsorption capacity of the solid adsorbent material (8) decreases due to temperature rise or saturation, causing the internal pressure of the liquid hydrogen storage tank to reach the preset second threshold, the cryogenic hydrogen regulating valve (15) is opened, so that the high-pressure hydrogen in the liquid hydrogen storage tank flows through the cryogenic hydrogen regulating valve (15) and generates a throttling cooling effect. The generated cryogenic fluid flows through the cryogenic heat exchanger (16), thereby actively cooling the solid adsorbent material (8) and increasing its adsorption capacity. Desorption and recovery steps: When hydrogen needs to be supplied to the outside, the external ambient temperature high pressure hydrogen enters the intermediate heater (10) through the ambient temperature hydrogen inlet valve (13) and then leaves the intermediate heater (10) through the ambient temperature hydrogen exhaust valve (14). After the intermediate heater (10) is heated, the solid adsorbent material (8) is heated, which causes the adsorbed hydrogen to be discharged through the adsorbed hydrogen exhaust valve (17), restoring the hydrogen adsorption capacity of the solid adsorbent material (8) for use in the next cycle.

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