Hydrogen liquefaction and zero boil-off storage integrated system

Abstract

The present application relates to hydrogen energy, hydrogen liquefaction and liquid hydrogen storage technical field, specifically relates to a kind of hydrogen liquefaction and zero evaporation storage integrated system.The system includes: normal temperature source hydrogen pipeline, normal temperature regulating valve, compressor unit, normal temperature high-pressure helium pipeline, hydrogen liquefaction cold box, low-temperature helium backflow regulating valve, high-pressure low-temperature helium regulating valve, liquid hydrogen pipeline, low-temperature helium pipeline, liquid hydrogen pneumatic regulating valve, adjustable refrigeration unit, low-temperature helium spiral pipeline, liquid hydrogen storage tank inner container, low-temperature helium cold screen, high vacuum multilayer insulation, liquid hydrogen storage tank outer container, pressure sensor, low-temperature helium backflow pipeline, low-temperature helium cold screen regulating valve.The system introduces low-temperature helium of helium refrigeration circuit into liquid hydrogen storage tank after refrigeration by adjustable refrigeration unit, and realizes liquid hydrogen supercooling degree control and liquid hydrogen flash gas recondensation by low-temperature helium spiral pipeline, so as to achieve the effect of making full use of hydrogen liquefier cold energy, ensuring liquid hydrogen supercooling and long-term zero evaporation storage.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy, hydrogen liquefaction and liquid hydrogen storage, and in particular to a hydrogen liquefaction and zero-evaporation storage integrated system. Background Art

[0002] Hydrogen energy is a crucial clean energy source in the context of the "dual carbon" initiative. Compared to traditional energy sources, it boasts advantages such as higher specific thermal energy, higher latent heat, and non-toxic combustion products. Compared to other renewable energy sources like wind and solar energy, it is relatively easy to store. With the rapid development of the hydrogen energy industry, higher requirements have been placed on its utilization.

[0003] Hydrogen storage methods primarily include high-pressure gaseous hydrogen storage, metal hydride hydrogen storage, and cryogenic liquid hydrogen storage. Cryogenic liquid hydrogen storage utilizes a hydrogen liquefaction cycle to store hydrogen in liquid form. This method offers high storage density and relatively good safety, making it a high-quality hydrogen storage option. Hydrogen liquefaction cycles primarily include the JT throttling liquefaction cycle, the helium-cooled hydrogen liquefaction cycle, and the hydrogen expansion-cooled hydrogen liquefaction cycle. After liquefaction, the hydrogen is stored in liquid hydrogen tanks. Liquid hydrogen storage employs passive insulation methods, primarily pearlescent sand insulation or high-vacuum multi-layer insulation, to suppress evaporation, as well as active zero-evaporation storage technology, which utilizes chiller energy to provide cooling for heat transfer. Currently, the hydrogen liquefaction unit and the liquid hydrogen tank are connected by simple physical piping. Furthermore, due to the low boiling point and volatile nature of liquid hydrogen, long-term storage of liquid hydrogen carries the risk of hydrogen flash vapor pressurization and gaseous hydrogen leakage within the tank, posing safety risks. Furthermore, existing hydrogen liquefaction cycles and zero-evaporation storage methods consume significant energy and are costly. Summary of the Invention

[0004] An embodiment of the present invention provides a hydrogen liquefaction and zero-boiloff storage integrated system to at least solve the technical problem in the prior art of insufficiently utilizing the cold energy of the hydrogen liquefier.

[0005] According to one embodiment of the present invention, a hydrogen liquefaction and zero-evaporation storage integrated system is provided, comprising: a normal temperature source hydrogen pipeline, a normal temperature regulating valve, a compressor unit, a normal temperature high-pressure helium pipeline, a hydrogen liquefaction cold box, a low-temperature helium reflux regulating valve, a high-pressure low-temperature helium regulating valve, a liquid hydrogen pipeline, a low-temperature helium pipeline, a liquid hydrogen pneumatic regulating valve, an adjustable refrigeration unit, a low-temperature helium spiral pipeline, a liquid hydrogen storage tank inner container, a low-temperature helium cold shield, a high-vacuum multi-layer insulation layer, a liquid hydrogen storage tank outer container, a pressure sensor, a low-temperature helium reflux pipeline, and a low-temperature helium cold shield regulating valve; the pressure sensor is arranged in the liquid hydrogen storage tank inner container, and the liquid hydrogen storage tank inner container, the high-vacuum multi-layer insulation layer, and the liquid hydrogen storage tank outer container are arranged in order from the inside to the outside, wherein:

[0006] In the hydrogen pipeline, hydrogen flows from the hydrogen source through the normal temperature source hydrogen pipeline and the normal temperature regulating valve into the hydrogen liquefaction cold box. The hydrogen is cooled by heat exchange in the hydrogen liquefaction cold box and becomes liquid hydrogen. The liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve and enters the liquid hydrogen storage tank through the liquid hydrogen pipeline for liquid hydrogen filling.

[0007] In the helium pipeline, the room temperature helium that passes through the compressor unit enters the hydrogen liquefaction cold box through the room temperature and high pressure helium pipeline, forming high pressure and low temperature helium and being divided into two paths. One path passes through the high pressure and low temperature reflux regulating valve and returns to the hydrogen liquefaction cold box through the reflux pipe; the other path passes through the high pressure and low temperature pneumatic regulating valve, is cooled by the low temperature helium pipeline, and is further cooled by the adjustable refrigeration unit, and enters the liquid hydrogen storage tank in the form of a low temperature helium spiral pipeline; the low temperature helium spiral pipeline is connected to the helium pipeline coiled outside the inner container of the liquid hydrogen storage tank, and the helium enters the coiled pipeline to form a low temperature helium cold screen; the helium then passes through the low temperature helium cold screen regulating valve, returns to the hydrogen liquefaction cold box through the low temperature helium reflux pipeline and enters the compressor unit.

[0008] Furthermore, the low-temperature helium spiral pipeline is in non-contact with the liquid hydrogen in the container of the liquid hydrogen storage tank. The low-temperature helium spiral pipeline is in contact with the liquid hydrogen flash vapor in the container of the liquid hydrogen storage tank and then condensed.

[0009] Furthermore, in the hydrogen pipeline, liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve and enters the liquid hydrogen storage tank container through the liquid hydrogen pipeline for liquid hydrogen filling. There are more than one pipelines; in the helium pipeline, there are more than two pipelines for the other route.

[0010] Furthermore, the adjustable refrigeration unit is one or more JT throttle valves or turbine expanders with bypass branches connected in series, parallel, or a series-parallel combination, which adjusts the subcooling of the liquid hydrogen in the container of the liquid hydrogen storage tank by controlling the inlet temperature of the low-temperature helium spiral pipeline in the liquid hydrogen storage tank.

[0011] Furthermore, the compressor unit is a twin-screw compressor unit or a centrifugal compressor unit, including low-pressure, medium-pressure and high-pressure pipelines.

[0012] Furthermore, the hydrogen liquefaction cold box is a helium refrigeration hydrogen liquefaction cycle with liquid nitrogen, liquefied natural gas or mixed working fluid pre-cooling, including multiple low-temperature heat exchangers, helium turbine expansion units, 80K and 35K low-temperature adsorbers, and normal-para hydrogen converter low-temperature equipment.

[0013] Furthermore, the cryogenic helium reflux regulating valve, high-pressure cryogenic helium regulating valve, liquid hydrogen pneumatic regulating valve, and cryogenic helium cold screen regulating valve are cryogenic pneumatic regulating valves; the liquid hydrogen pipeline and cryogenic helium pipeline use high-vacuum multi-layer insulated cryogenic pipelines.

[0014] Furthermore, the outer tube of the cryogenic helium spiral pipeline adopts a plain tube or a fin, and the cryogenic helium spiral pipeline is placed vertically inside the inner container of the liquid hydrogen storage tank. It is in direct contact with the liquid hydrogen and the liquid hydrogen flash gas on the upper part of the liquid hydrogen storage tank to perform inter-wall heat exchange.

[0015] Furthermore, the cryogenic helium flowing from the cryogenic helium pipeline enters from the lower part of the cryogenic helium spiral pipeline, and the saturated cryogenic hydrogen evaporated from the liquid hydrogen in the upper part of the container in the liquid hydrogen storage tank is recondensed by the inter-wall heat exchange with the cryogenic helium spiral pipeline.

[0016] Furthermore, the cryogenic helium cold shield is spirally wound around the outer side of the inner container of the liquid hydrogen storage tank and fixed with a copper heat sink. The copper heat sink and the cryogenic helium cold shield are bonded with a high thermal conductivity low-temperature adhesive or fixed with copper or aluminum bolts.

[0017] The cryogenic helium enters the cold shield structure from the cryogenic helium spiral pipeline on the upper part of the liquid hydrogen storage tank;

[0018] The cold shield structure consists of a spiral structure in which the helium pipeline is coiled around the container inside the liquid hydrogen tank;

[0019] The thermal insulation layer is formed by a low-temperature helium cold screen and a high-vacuum multi-layer insulation layer.

[0020] The integrated hydrogen liquefaction and zero-evaporation storage system in the embodiment of the present invention introduces the low-temperature helium gas from the helium refrigeration circuit into the liquid hydrogen storage tank after throttling refrigeration, and controls the subcooling degree of the liquid hydrogen in the storage tank and recondenses the low-temperature hydrogen after evaporation of the liquid hydrogen through a low-temperature helium spiral pipeline, thereby achieving the effect of fully utilizing the cold energy of the hydrogen liquefier, ensuring the supercooling of the liquid hydrogen and long-term zero-evaporation storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 This is a structural diagram of Example 1 of the hydrogen liquefaction and zero-boiloff storage integrated system of the present invention;

[0023] Figure 2 This is a structural diagram of Example 2 of the hydrogen liquefaction and zero-boiloff storage integrated system of the present invention;

[0024] Figure 3 This is a structural diagram of Example 3 of the hydrogen liquefaction and zero-evaporation storage integrated system of the present invention.

[0025] Markings in the figure are: 1-normal temperature source hydrogen pipeline, 2-normal temperature regulating valve, 3-compressor unit, 4-normal temperature high-pressure helium pipeline, 5-hydrogen liquefaction cold box, 6-cryogenic helium reflux regulating valve, 7-high-pressure cryogenic helium regulating valve, 8-liquid hydrogen pipeline, 9-cryogenic helium pipeline, 10-liquid hydrogen pneumatic regulating valve, 11-adjustable refrigeration unit, 12-cryogenic helium spiral pipeline, 13-liquid hydrogen storage tank inner container, 14-cryogenic helium cold shield, 15-high vacuum multi-layer insulation layer, 16-liquid hydrogen storage tank outer container, 17-pressure sensor, 18-cryogenic helium reflux pipeline, 19-cryogenic helium cold shield regulating valve;

[0026] The second cryogenic helium pipeline 9-1, the second liquid hydrogen pneumatic regulating valve 10-1, the second adjustable refrigeration unit 11-1, the second cryogenic helium spiral pipeline 12-1, the second liquid hydrogen storage tank inner container 13-1, the second cryogenic helium cold shield 14-1, the second high vacuum multi-layer insulation layer 15-1, the second liquid hydrogen storage tank outer container 16-1, the second pressure sensor 17-1, the second cryogenic helium reflux pipeline 18-1, and the second cryogenic helium cold shield regulating valve 19-1. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] To address the deficiencies of the prior art, the present invention provides an integrated system for hydrogen liquefaction and zero-evaporation storage. The low-temperature helium gas in the helium refrigeration circuit is cooled by an adjustable refrigeration unit and then introduced into a liquid hydrogen storage tank. The low-temperature helium spiral pipeline is used to control the subcooling degree of the liquid hydrogen in the storage tank and to recondense the liquid hydrogen flash gas (i.e., the low-temperature hydrogen gas after the evaporation of liquid hydrogen), thereby achieving the effect of fully utilizing the cold energy of the hydrogen liquefier, ensuring the supercooling of the liquid hydrogen and long-term zero-evaporation storage.

[0030] Example 1 Figure 1 As shown, a hydrogen liquefaction and zero-evaporation storage integrated system includes a room-temperature source hydrogen pipeline 1, a room-temperature regulating valve 2, a compressor unit 3, a room-temperature high-pressure helium pipeline 4, a hydrogen liquefaction cold box 5, a low-temperature helium reflux regulating valve 6, a high-pressure low-temperature helium regulating valve 7, a liquid hydrogen pipeline 8, a low-temperature helium pipeline 9, a liquid hydrogen pneumatic regulating valve 10, an adjustable refrigeration unit 11, a low-temperature helium spiral pipeline 12, a liquid hydrogen storage tank inner container 13, a low-temperature helium cold shield 14, a high-vacuum multi-layer insulation layer 15, a liquid hydrogen storage tank outer container 16, a pressure sensor 17, a low-temperature helium reflux pipeline 18, and a low-temperature helium cold shield regulating valve 19.

[0031] The hydrogen source gas is connected to the hydrogen liquefaction cold box 5 via a room-temperature source hydrogen pipeline 1. The hydrogen liquefaction cold box 5 and the liquid hydrogen storage tank are connected via a liquid hydrogen pipeline 8, a cryogenic helium pipeline 9, and a cryogenic helium return pipeline 18. The room-temperature source hydrogen pipeline 1 is equipped with a room-temperature regulating valve 2, the liquid hydrogen pipeline 8 is equipped with a liquid hydrogen pneumatic regulating valve 10, and the cryogenic helium pipeline 9 is equipped with a high-pressure, low-temperature pneumatic regulating valve 7 and an adjustable refrigeration unit 11. The adjustable refrigeration unit 11 is composed of one or more JT throttle valves or turbine expanders with bypass branches connected in series, parallel, or a combination of these. By effectively controlling the inlet temperature of the cryogenic helium spiral pipeline within the liquid hydrogen storage tank, the subcooling of the liquid hydrogen contained within the liquid hydrogen storage tank is adjusted. The cryogenic helium return pipeline 18 is equipped with a cryogenic helium cold shield regulating valve 19.

[0032] When the hydrogen liquefaction process is carried out, the normal temperature regulating valve 2, the low temperature helium reflux regulating valve 6, the high pressure low temperature helium regulating valve 7, the liquid hydrogen pneumatic regulating valve 10 and the low temperature helium cold shield regulating valve 19 are opened.

[0033] In the hydrogen pipeline, hydrogen enters the hydrogen liquefaction cold box 5 from the hydrogen source through the normal temperature source hydrogen pipeline 1. The hydrogen is cooled by heat exchange and becomes liquid hydrogen. The liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve 10 and enters the liquid hydrogen storage tank container 13 through the liquid hydrogen pipeline 8 for liquid hydrogen filling. In the helium pipeline, the room temperature helium that passes through the compressor unit 3 enters the hydrogen liquefaction cold box 5 through the room temperature high-pressure helium pipeline 4, forming high-pressure low-temperature helium and being divided into two paths. One path passes through the high-pressure low-temperature reflux regulating valve 6 and returns to the hydrogen liquefaction cold box 5 through the reflux pipe; the other path passes through the high-pressure low-temperature pneumatic regulating valve 7, and is cooled in series, in parallel or in series-parallel combination through one or more JT throttle valves or turbine expanders with bypass branches, and enters the low-temperature helium spiral pipeline 12 inside the liquid hydrogen storage tank through the low-temperature helium pipeline 9; the low-temperature helium spiral pipeline 12 is connected to the helium pipeline coiled outside the container 13 in the liquid hydrogen storage tank, and the helium enters the spiral pipeline to form a low-temperature helium cold screen 14; the helium then passes through the low-temperature helium cold screen regulating valve 19, returns to the hydrogen liquefaction cold box 5 through the low-temperature helium reflux pipeline 18 and enters the compressor unit 3.

[0034] There are two operating modes: one is to store liquid for the hydrogen liquefier, while allowing some flow through the valve for subcooling and zero boil-off. The other is when the liquid hydrogen filling process is complete, the normal temperature control valve 2, liquid hydrogen pneumatic control valve 10, cryogenic helium reflux control valve 6, high-pressure cryogenic helium control valve 7, and cryogenic helium cold shield control valve 19 are closed. The hydrogen liquefaction process is shut down, and the hydrogen liquefier enters a low-power operating state, using the cold energy of the helium circulation circuit to achieve liquid hydrogen subcooling and liquid hydrogen flash vapor recondensation. At this time, no more liquid hydrogen enters the liquid hydrogen storage tank 13. As heat leaks from the outside, the flash gas after the liquid hydrogen evaporates gradually increases, and the pressure in the storage tank gradually rises. The pressure sensor 17 monitors the pressure in the storage tank in real time. When the pressure in the storage tank reaches the set pressure, the high-pressure low-temperature helium reflux regulating valve 6, the high-pressure low-temperature helium regulating valve 7, and the low-temperature helium cold shield regulating valve 19 are opened in sequence, and the valve opening is adjusted to control the helium flow rate, so that the liquid hydrogen inside the liquid hydrogen storage tank is supercooled and the flash gas evaporated from the upper part of the liquid hydrogen storage tank inner container 13 is recondensed. At the same time, after passing through the low-temperature helium spiral pipeline 12, it enters the helium pipeline coiled around the outside of the liquid hydrogen storage tank inner container 13. The helium enters the coiled pipeline to form a low-temperature helium cold shield, which effectively isolates the heat leakage from the outside and suppresses the evaporation of liquid hydrogen, thereby achieving the effect of zero evaporation storage of the liquid hydrogen storage tank.

[0035] The normal temperature source hydrogen pipeline 1 uses a normal temperature hydrogen pipeline to transport hydrogen to the hydrogen liquefaction cold box 5.

[0036] The compressor unit 3 may be a twin-screw compressor unit or a centrifugal compressor unit, and may include low-pressure, medium-pressure and high-pressure pipelines.

[0037] The room temperature and high pressure helium pipeline 4 contains the room temperature and high pressure helium compressed by the compressor unit 3, and transports the circulating working medium helium to the hydrogen liquefaction cold box 5.

[0038] The hydrogen liquefaction cold box 5 is a hydrogen liquefaction cycle with helium refrigeration and pre-cooling with liquid nitrogen, liquefied natural gas or a mixed working medium. The hydrogen liquefaction cold box 5 includes multiple low-temperature heat exchangers, helium turbine expanders (groups), 80K and 35K low-temperature adsorbers, normal-para hydrogen converters and other low-temperature equipment.

[0039] The cryogenic helium reflux regulating valve 6, the high-pressure cryogenic helium regulating valve 7, the liquid hydrogen pneumatic regulating valve 10, and the cryogenic helium cold shield regulating valve 19 are cryogenic pneumatic regulating valves. By intelligently controlling the valve openings of the ambient temperature regulating valve 2 and the liquid hydrogen pneumatic regulating valve 10, the flow rate in the hydrogen liquefaction pipeline can be controlled, thereby adjusting the hydrogen liquefaction rate. The cooling capacity of the helium circulation pipeline is controlled by the adjustable refrigeration unit 11. The flow rate in the helium circulation pipeline can be controlled by controlling the cryogenic helium reflux regulating valve 6, the high-pressure cryogenic helium regulating valve 7, and the cryogenic helium cold shield regulating valve 19. By coupling and matching the flow rates of the helium circulation pipeline and the hydrogen liquefaction pipeline, hydrogen liquefaction, liquid hydrogen subcooling, and long-term zero-evaporation storage are achieved.

[0040] Liquid hydrogen pipeline 8 and cryogenic helium pipeline 9 utilize high-vacuum, multi-layer, thermally insulated cryogenic pipelines, reducing system heat leakage from the liquid hydrogen storage tank's external piping. Liquid hydrogen produced by the hydrogen liquefaction cold box 5 passes through a liquid hydrogen pneumatic regulating valve 10 and is then transferred through the liquid hydrogen pipeline 8 into the liquid hydrogen storage tank's inner container 13. Cryogenic helium from the hydrogen liquefaction cold box 5 passes through a high-pressure, cryogenic helium regulating valve 7 and enters an adjustable refrigeration unit 11, where it undergoes a cooling effect, cooling the helium to below 20K. The helium then enters the cryogenic helium spiral pipeline 12 inside the liquid hydrogen storage tank via the cryogenic helium pipeline 9.

[0041] The adjustable refrigeration unit 11 can be one or more JT throttle valves or turbine expanders with bypass branches connected in series, parallel, or a series-parallel combination. The JT throttle valve can use a pneumatic low-temperature throttle valve to dynamically adjust the throttling refrigeration effect by adjusting the valve opening; the turbine expander can use a low-temperature turbine expander to dynamically adjust the refrigeration effect by controlling the power of the turbine expander.

[0042] The low-temperature helium spiral pipeline 12 is made of aluminum alloy or copper coil to form a spiral tube.

[0043] In order to improve the heat exchange efficiency and heat exchange area, the outer tube of the helium spiral pipeline can be finned. At the same time, the helium spiral pipeline is placed vertically inside the liquid hydrogen storage tank, so that it can be in direct contact with the liquid hydrogen and the liquid hydrogen flash gas on the upper part of the liquid hydrogen storage tank to perform inter-wall heat exchange.

[0044] Furthermore, in order to achieve the functions of supercooling liquid hydrogen and recondensing the liquid hydrogen flash gas at the top of the liquid hydrogen storage tank, the low-temperature helium flowing from the low-temperature helium pipeline 9 enters from the lower part of the low-temperature helium spiral pipeline 12. In this way, the saturated liquid hydrogen at the bottom of the container 13 in the liquid hydrogen storage tank and the low-temperature helium below 20K are exchanged through the partition wall of the low-temperature helium spiral pipeline 12, which can achieve the purpose of supercooling the liquid hydrogen. The saturated low-temperature hydrogen evaporated from the liquid hydrogen at the top of the container 13 in the liquid hydrogen storage tank and the low-temperature helium spiral pipeline 12 are exchanged through the partition wall, which can achieve the recondensation of the saturated low-temperature hydrogen.

[0045] The low-temperature helium cold shield 14 is spirally wound around the outside of the liquid hydrogen storage tank container 13 and fixed with a copper heat sink. The copper heat sink and the low-temperature helium cold shield 14 can be connected by high thermal conductivity low-temperature adhesive or copper / aluminum bolts.

[0046] In order to fully utilize the cold energy of the cryogenic helium, the cryogenic helium enters the cold shield structure from the cryogenic helium spiral pipeline 12 on the upper part of the container 13 in the liquid hydrogen storage tank.

[0047] In order to improve the shielding effect of the cold screen, the cold screen structure is composed of a spiral structure in which the helium pipeline is coiled around the container 13 in the liquid hydrogen storage tank, which can effectively suppress heat leakage of the liquid hydrogen storage tank and inhibit the evaporation of liquid hydrogen.

[0048] The structure of liquid hydrogen storage tanks can be horizontal, vertical or spherical.

[0049] In order to reduce heat leakage and suppress the escape of liquid hydrogen flash gas, an insulation layer composed of a low-temperature helium cold shield 14 and a high-vacuum multi-layer insulation layer 15 is used to form a thermal insulation layer.

[0050] In this system, a helium-refrigerated hydrogen liquefaction process is used. In order to fully utilize the cooling capacity of cryogenic helium, a spiral tube is used inside the liquid hydrogen storage tank to supercool the liquid hydrogen in the tank to suppress evaporation of liquid hydrogen; a cryogenic helium pipeline is wrapped around the outside of the tank container as a cold shield to form an insulating layer.

[0051] The working principle of the present invention is as follows: the system realizes the integrated functions of hydrogen liquefaction and liquid hydrogen zero-evaporation storage. The room-temperature high-pressure helium pipeline 4 and the room-temperature source hydrogen pipeline 1 enter the hydrogen liquefaction cold box 5. The hydrogen liquefaction cycle using helium refrigeration is used. The produced liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve 10 and enters the interior of the liquid hydrogen storage tank container 13 through the liquid hydrogen pipeline 8, achieving hydrogen liquefaction and filling. The 20K low-temperature helium is divided into two paths. One path passes through the low-temperature helium reflux regulating valve 6 and returns to the hydrogen liquefaction cold box 5 through the reflux pipeline; the other path is cooled by the adjustable refrigeration unit 11 to form low-temperature helium below 20K. It passes through the low-temperature helium pipeline 9 and enters the low-temperature helium spiral pipeline 12 inside the liquid hydrogen storage tank from the bottom of the liquid hydrogen storage tank, supercooling the liquid hydrogen in the liquid hydrogen storage tank container 13 and recondensing the flash gas evaporated from the liquid hydrogen above. The cryogenic helium enters the helium pipeline coiled on the outer surface of the inner container 13 of the liquid hydrogen storage tank from the cryogenic helium spiral pipeline 12 on the upper part of the liquid hydrogen storage tank, forming a cryogenic helium cold shield 14, and then returns to the hydrogen liquefaction cold box 5 from the liquid hydrogen storage tank through the cryogenic helium cold shield regulating valve 19 and the cryogenic helium reflux pipeline 18 to merge with the first helium reflux, thereby realizing a closed circulation process.

[0052] The advantages of the present invention are: the system realizes the integrated operation of hydrogen liquefaction and liquid hydrogen zero-evaporation storage; based on the hydrogen liquefaction cycle of helium refrigeration, the low-temperature helium in the helium refrigeration circuit is introduced into the low-temperature helium spiral pipeline inside the liquid hydrogen storage tank through throttling or expansion refrigeration to realize the supercooling control of the liquid hydrogen in the storage tank, and at the same time realize the recondensation of the flash gas in the storage tank, thereby fully utilizing the cold energy of the low-temperature helium pipeline and ensuring the supercooling of liquid hydrogen and long-term zero-evaporation storage; the cold screen fully utilizes the cold energy of the low-temperature helium pipeline to realize the reuse of cold capacity; the throttle valve uses a high-vacuum insulated throttle valve; the integrated system uses a pressure sensor for pressure detection and adjusts the valve opening and the liquefaction rate of the hydrogen liquefier to realize zero-evaporation storage of liquid hydrogen; the system realizes the different functions of one or more liquid hydrogen storage tanks by switching valves and adjusting the valve opening. This invention is suitable for medium and large-scale helium-refrigerated hydrogen liquefaction cycles and long-term storage of liquid hydrogen.

[0053] Example 2 Figure 2 As shown, the basic structure of the system is the same as that of Example 1.

[0054] In this embodiment, the cryogenic helium pipeline 9 does not contact the liquid hydrogen in the container 13 of the liquid hydrogen storage tank. The pipes in the container 13 of the liquid hydrogen storage tank are in contact with the liquid hydrogen flash gas and then condensed. The other working processes are the same as those in Example 1, realizing the function of zero evaporation storage of liquid hydrogen.

[0055] Example 3 Figure 3As shown, a hydrogen liquefaction and zero-evaporation storage integrated system includes a room temperature source hydrogen pipeline 1, a room temperature regulating valve 2, a compressor unit 3, a room temperature high-pressure helium pipeline 4, a hydrogen liquefaction cold box 5, a low-temperature helium reflux regulating valve 6, a high-pressure low-temperature helium regulating valve 7, a liquid hydrogen pipeline 8, a low-temperature helium pipeline 9, a liquid hydrogen pneumatic regulating valve 10, an adjustable refrigeration unit 11, a low-temperature helium spiral pipeline 12, a liquid hydrogen storage tank inner container 13, a low-temperature helium cold shield 14, a high vacuum multi-layer insulation layer 15, a liquid hydrogen storage tank outer container 16, and a pressure sensor 17. Cryogenic helium reflux pipeline 18, cryogenic helium cold shield regulating valve 19, second cryogenic helium pipeline 9-1, second liquid hydrogen pneumatic regulating valve 10-1, second adjustable refrigeration unit 11-1, second cryogenic helium spiral pipeline 12-1, second liquid hydrogen storage tank inner container 13-1, second cryogenic helium cold shield 14-1, second high vacuum multi-layer insulation layer 15-1, second liquid hydrogen storage tank outer container 16-1, second pressure sensor 17-1, second cryogenic helium reflux pipeline 18-1, second cryogenic helium cold shield regulating valve 19-1.

[0056] When the liquid hydrogen storage tank outer container 16 is undergoing the hydrogen liquefaction filling process and the second liquid hydrogen storage tank outer container 16-1 is undergoing the zero evaporation storage process, the normal temperature regulating valve 2, the low-temperature helium reflux regulating valve 6, the high-pressure low-temperature helium regulating valve 7, the liquid hydrogen pneumatic regulating valve 10 and the low-temperature helium cold shield regulating valve 19 and the second low-temperature helium cold shield regulating valve 19-1 are opened, and the second liquid hydrogen pneumatic regulating valve 10-1 is closed.

[0057] At this point, in the hydrogen pipeline, liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve 10 and enters the inner container 13 of the liquid hydrogen storage tank through the liquid hydrogen pipeline 8 for liquid hydrogen filling. In the helium pipeline, high-pressure, low-temperature helium passes through the high-pressure, low-temperature pneumatic regulating valve 7 and is divided into two paths. One path passes through the low-temperature helium pipeline 9 and enters the low-temperature helium spiral pipeline 12 inside the liquid hydrogen storage tank. The hydrogen liquefaction function of the liquid hydrogen storage tank outer container 16 is implemented in the same manner as in Example 1. The other path passes through the second low-temperature helium pipeline 9-1 and enters the second low-temperature helium spiral pipeline 12-1 inside the liquid hydrogen storage tank. The liquid hydrogen zero-evaporation storage function of the liquid hydrogen storage tank outer container 16 is implemented in the same manner as in Example 1.

[0058] On the contrary, when the second liquid hydrogen storage tank outer container 16-1 is undergoing the hydrogen liquefaction filling process and the liquid hydrogen storage tank outer container 16 is undergoing the zero evaporation storage process, the normal temperature regulating valve 2, the low-temperature helium reflux regulating valve 6, the high-pressure low-temperature helium regulating valve 7, the second liquid hydrogen pneumatic regulating valve 10-1 and the low-temperature helium cold shield regulating valve 19 and the second low-temperature helium cold shield regulating valve 19-1 are opened, and the liquid hydrogen pneumatic regulating valve 10 is closed. The working process is the same as above. Examples 1 and 2 realize the functions of hydrogen liquefaction and zero evaporation storage. Example 3 can simultaneously realize hydrogen liquefaction, fully utilize the cold energy of the hydrogen liquefier, ensure the different functions of liquid hydrogen supercooling and long-term zero evaporation storage.

[0059] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0060] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0061] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only exemplary. For example, the division of units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0062] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0063] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0064] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc. Various media that can store program codes.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A hydrogen liquefaction and zero-evaporation storage integrated system, characterized in that: include: Normal temperature source hydrogen pipeline, normal temperature regulating valve, compressor unit, normal temperature high pressure helium pipeline, hydrogen liquefaction cold box, low temperature helium reflux regulating valve, high pressure low temperature helium regulating valve, liquid hydrogen pipeline, low temperature helium pipeline, liquid hydrogen pneumatic regulating valve, adjustable refrigeration unit, low temperature helium spiral pipeline, liquid hydrogen storage tank inner container, low temperature helium cold shield, high vacuum multi-layer insulation layer, liquid hydrogen storage tank outer container, pressure sensor, low temperature helium reflux pipeline, low temperature helium cold shield regulating valve; the pressure sensor is arranged in the liquid hydrogen storage tank inner container, the liquid hydrogen storage tank inner container, high vacuum multi-layer insulation layer, and liquid hydrogen storage tank outer container are arranged from the inside to the outside, wherein: In the hydrogen pipeline, hydrogen flows from the hydrogen source through the normal temperature source hydrogen pipeline and the normal temperature regulating valve into the hydrogen liquefaction cold box. The hydrogen is cooled by heat exchange in the hydrogen liquefaction cold box and becomes liquid hydrogen. The liquid hydrogen passes through the liquid hydrogen pneumatic regulating valve and enters the liquid hydrogen storage tank through the liquid hydrogen pipeline for liquid hydrogen filling. In the helium pipeline, the room temperature helium that passes through the compressor unit enters the hydrogen liquefaction cold box through the room temperature and high pressure helium pipeline, forming high pressure and low temperature helium and being divided into two paths. One path passes through the high pressure and low temperature reflux regulating valve and returns to the hydrogen liquefaction cold box through the reflux pipe; the other path passes through the high pressure and low temperature pneumatic regulating valve, is cooled by the low temperature helium pipeline, and is further cooled by the adjustable refrigeration unit, and enters the liquid hydrogen storage tank in the form of a low temperature helium spiral pipeline; the low temperature helium spiral pipeline is connected to the helium pipeline coiled outside the inner container of the liquid hydrogen storage tank, and the helium enters the coiled pipeline to form a low temperature helium cold screen; the helium then passes through the low temperature helium cold screen regulating valve, returns to the hydrogen liquefaction cold box through the low temperature helium reflux pipeline and enters the compressor unit.

2. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The cryogenic helium spiral pipeline is not in contact with the liquid hydrogen in the container of the liquid hydrogen storage tank. The cryogenic helium spiral pipeline is laid in the container of the liquid hydrogen storage tank and contacts with the liquid hydrogen flash gas and then condenses.

3. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: In the hydrogen pipeline, there is more than one pipeline for liquid hydrogen to pass through the liquid hydrogen pneumatic regulating valve and enter the liquid hydrogen storage tank container through the liquid hydrogen pipeline for liquid hydrogen filling; in the helium pipeline, there are more than two other pipelines.

4. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The adjustable refrigeration unit is one or more JT throttle valves or turbine expanders with bypass branches connected in series, parallel or in a series-parallel combination. It adjusts the subcooling degree of the liquid hydrogen in the container of the liquid hydrogen storage tank by controlling the inlet temperature of the low-temperature helium spiral pipeline in the liquid hydrogen storage tank.

5. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The compressor unit is a twin-screw compressor unit or a centrifugal compressor unit, including low-pressure, medium-pressure and high-pressure pipelines.

6. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The hydrogen liquefaction cold box is a helium refrigeration hydrogen liquefaction cycle with liquid nitrogen, liquefied natural gas or mixed working fluid pre-cooling, including multiple low-temperature heat exchangers, helium turbine expansion units, 80K and 35K low-temperature adsorbers, and normal-para hydrogen converter low-temperature equipment.

7. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The cryogenic helium reflux regulating valve, high-pressure cryogenic helium regulating valve, liquid hydrogen pneumatic regulating valve, and cryogenic helium cold screen regulating valve are cryogenic pneumatic regulating valves; the liquid hydrogen pipeline and cryogenic helium pipeline use high-vacuum multi-layer insulated cryogenic pipelines.

8. The hydrogen liquefaction and zero-evaporation storage integrated system according to claim 1, characterized in that: The outer tube of the cryogenic helium spiral pipeline adopts a plain tube or fins. At the same time, the cryogenic helium spiral pipeline is placed vertically inside the inner container of the liquid hydrogen storage tank. It is in direct contact with the liquid hydrogen and the liquid hydrogen flash gas on the upper part of the liquid hydrogen storage tank to perform inter-wall heat exchange.

9. The integrated hydrogen liquefaction and zero-evaporation storage system according to claim 1, characterized in that: The cryogenic helium flowing from the cryogenic helium pipeline enters from the lower part of the cryogenic helium spiral pipeline, and the saturated cryogenic hydrogen evaporated from the liquid hydrogen in the upper part of the liquid hydrogen storage tank is recondensed by the inter-wall heat exchange with the cryogenic helium spiral pipeline.

10. The integrated hydrogen liquefaction and zero-evaporation storage system according to claim 1, characterized in that: The cryogenic helium cold shield is spirally wound around the outside of the liquid hydrogen storage tank and fixed with a copper heat sink. The copper heat sink and the cryogenic helium cold shield are bonded with high thermal conductivity low-temperature adhesive or fixed with copper or aluminum bolts. The cryogenic helium enters the cold shield structure from the cryogenic helium spiral pipeline on the upper part of the liquid hydrogen storage tank; The cold shield structure consists of a spiral structure in which the helium pipeline is coiled around the container inside the liquid hydrogen tank; The thermal insulation layer is formed by a low-temperature helium cold screen and a high-vacuum multi-layer insulation layer.

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