A low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle

Abstract

The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided by the present application comprises: a hydrogen boosting unit (1), a reverse Brayton cycle refrigeration unit (2) and a low-temperature and high-pressure hydrogen storage tank unit (3), wherein the hydrogen boosting unit (1) comprises a multi-stage hydrogen compressor (101) and a first aftercooler (102), wherein the multi-stage hydrogen compressor (101) is used to boost the pressure of hydrogen to a certain optimized storage pressure, and the reverse Brayton cycle refrigeration unit (2) is a reverse Brayton cycle, which comprises a compressor (201), a second aftercooler (202), a regenerator (203) and an expander (204). The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided by the present application compresses hydrogen at room temperature, distributes and cools it, and stores it at low temperature, and adopts the reverse Brayton cycle to provide cooling capacity for high-pressure hydrogen cooling. The system has the advantages of high hydrogen storage density, high hydrogen cooling efficiency, no need for normal-parahydrogen conversion, adaptability to large-scale hydrogen storage, and convenient acquisition and replenishment of working fluids.

Description

Technical Field

[0001] The present application relates to the field of low-temperature refrigeration and hydrogen storage technology, and in particular to a low-temperature and high-pressure hydrogen storage system based on a reverse Brayton cycle. Background Art

[0002] As a new, clean alternative energy source, hydrogen holds enormous potential for development. However, due to its low density at room temperature, hydrogen faces numerous challenges in storage and transportation. In recent years, various methods for storing and transporting high-density hydrogen have emerged, including room-temperature, high-pressure hydrogen storage, cryogenic liquid hydrogen storage, and cryogenic, high-pressure hydrogen storage.

[0003] Normal temperature and high pressure hydrogen storage compresses hydrogen and stores it in high-pressure containers. This approach has low energy consumption, but the hydrogen storage density per unit volume is low, resulting in poor economic efficiency. Low temperature liquid hydrogen storage liquefies hydrogen and stores it in liquid hydrogen tanks. This approach has high hydrogen storage density and low hydrogen storage pressure, but the production of liquid hydrogen consumes a lot of energy, suffers from large evaporation losses, and results in high liquefaction equipment costs. Low temperature and high pressure hydrogen storage is a hydrogen storage method that combines the advantages of normal temperature and high pressure hydrogen storage with low temperature liquid hydrogen storage. It has high hydrogen storage density, low intrinsic energy consumption, and does not require ortho-parahydrogen conversion, thus showing great development potential. However, the current method of producing low temperature and high pressure hydrogen by pressurizing and gasifying liquid hydrogen consumes a lot of energy and is limited by liquid hydrogen production capacity. Summary of the Invention

[0004] In view of this, it is necessary to address the technical defects of high energy consumption and limited production capacity in the current production of low-temperature and high-pressure hydrogen by pressurized gasification of liquid hydrogen, and provide a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle that compresses hydrogen at room temperature, distributes cooling, and stores hydrogen at low temperature. The system has the advantages of high hydrogen storage density, high hydrogen cooling efficiency, no need for normal-parahydrogen conversion, adaptability to large-scale hydrogen storage, and convenient acquisition and replenishment of working fluids.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] The present application provides a low-temperature and high-pressure hydrogen storage system based on a reverse Brayton cycle, comprising: a hydrogen boosting unit, a reverse Brayton cycle refrigeration unit, and a low-temperature and high-pressure hydrogen storage tank unit, wherein:

[0007] The hydrogen boosting unit includes a multi-stage hydrogen compressor and a first aftercooler. The multi-stage hydrogen compressor is used to boost the hydrogen to a certain optimized storage pressure. The certain optimized storage pressure includes but is not limited to 10-100 MPa. There is at least one hydrogen boosting unit and they are connected in series.

[0008] The reverse Brayton cycle refrigeration unit is a reverse Brayton cycle, which includes a compressor, a second aftercooler, a regenerator and an expander, and the expander includes a multi-stage expander unit arranged in series or includes multiple expander units arranged in parallel;

[0009] The refrigerant is compressed by the compressor and enters the second aftercooler. After being cooled by the second aftercooler, it enters the regenerator and is cooled by the low-temperature refrigerant. It then enters the expander for cooling and pressure reduction, enters the regenerator to provide cooling, and then returns to the compressor to complete the cycle.

[0010] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and enters the regenerator and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature and high-pressure hydrogen; the low-temperature and high-pressure hydrogen enters the low-temperature and high-pressure hydrogen storage tank unit.

[0011] In some embodiments, the expander transmits the expansion work to the compressor in the form of electricity; or a supercharger turbocharger and a third aftercooler are arranged in front of the compressor, and the expander transmits the expansion work to the compressor through the third aftercooler and the supercharger turbocharger; or the compressor and expander are coaxially arranged to recover the expansion work.

[0012] In some embodiments, the refrigerant may be a mixture of one or more of nitrogen, argon, methane, R14, ethylene, helium, neon, and hydrogen.

[0013] In some embodiments, an evaporator is further included; wherein:

[0014] The refrigerant is compressed by the compressor and enters the second aftercooler. After being cooled by the second aftercooler, it enters the regenerator and is cooled by the low-temperature refrigerant. After entering the expander to reduce temperature and pressure, it enters the evaporator to cool the high-pressure refrigerant and then enters the regenerator.

[0015] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and enters the regenerator and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen enters the low-temperature and high-pressure hydrogen storage tank unit through the evaporator.

[0016] In some embodiments, the regenerator includes a first heat exchanger and a second heat exchanger;

[0017] The refrigerant is compressed by the compressor and enters the second aftercooler, is cooled by the second aftercooler, enters the regenerator and is cooled by the low-temperature refrigerant, and then enters the expander to be cooled and decompressed to form a first low-temperature fluid and a second low-temperature fluid;

[0018] The first cryogenic fluid returns to the compressor through the first heat exchanger to complete the cycle, and the second cryogenic fluid returns to the compressor through the second heat exchanger to complete the cycle;

[0019] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and enters the second heat exchanger and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0020] In some embodiments, a pre-cooling circulation unit is further included, wherein the pre-cooling circulation unit includes a pre-cooling unit and a pre-cooling heat exchanger, and the pre-cooling unit is used to provide cooling capacity to the pre-cooling heat exchanger;

[0021] The refrigerant is compressed by the compressor and enters the second aftercooler, and then enters the regenerator after passing through the precooling heat exchanger;

[0022] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen, and the high-pressure hydrogen is cooled by the first aftercooler and then enters the regenerator.

[0023] In some embodiments, the present invention further comprises a first-stage expander, a first-stage regenerator, and a second-stage regenerator;

[0024] The refrigerant is compressed by the compressor and enters the second aftercooler. After being cooled by the second aftercooler, it enters the first regenerator to be cooled by the low-temperature refrigerant. Then, it enters the first expander for cooling and decompression, then enters the regenerator and is cooled by the low-temperature refrigerant. Then, it enters the expander for cooling and decompression, then enters the regenerator to provide cooling capacity, and then returns to the compressor through the second regenerator and the first regenerator to complete the cycle.

[0025] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and then passes through the first-stage regenerator, the second-stage regenerator and the regenerator in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0026] In some embodiments, the present invention further comprises a first-stage expander, a first-stage regenerator, and a second-stage regenerator;

[0027] The refrigerant is compressed by the compressor and enters the second aftercooler, is cooled by the second aftercooler, and then enters the primary regenerator to be cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow;

[0028] The first cold flow passes through the secondary regenerator and the regenerator in sequence and is cooled by the low-temperature refrigerant, then enters the expander for cooling and decompression, and then enters the regenerator to provide cooling capacity, reheats, and flows out of the low-temperature and low-pressure refrigerant, and is mixed with the low-temperature and low-pressure refrigerant flowing out after the second cold flow passes through the primary expander for cooling and decompression, and the formed mixed low-temperature and low-pressure refrigerant then passes through the secondary regenerator and the primary regenerator in sequence and then returns to the compressor to complete the cycle;

[0029] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and then passes through the first-stage regenerator, the second-stage regenerator and the regenerator in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0030] In some embodiments, the expander unit is replaced by a throttling element, and the low-temperature and high-pressure hydrogen storage system further includes a first-stage expander, a first-stage regenerator, and a second-stage regenerator;

[0031] The refrigerant is compressed by the compressor and enters the second aftercooler, is cooled by the second aftercooler, and then enters the primary regenerator to be cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow;

[0032] The first cold flow passes through the secondary regenerator and the regenerator in sequence and is cooled by the low-temperature refrigerant, then enters the throttling element for temperature and pressure reduction, and then enters the regenerator to provide cold capacity for reheating and flows out of the low-temperature and low-pressure refrigerant, and is mixed with the low-temperature and low-pressure refrigerant flowing out after the second cold flow passes through the primary expander for temperature and pressure reduction. The formed mixed low-temperature and low-pressure refrigerant then passes through the secondary regenerator and the primary regenerator in sequence and then returns to the compressor to complete the cycle;

[0033] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler and then passes through the first-stage regenerator, the second-stage regenerator and the regenerator in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0034] In some embodiments, a first inlet valve is further included, one end of which is connected to the throttling element and the other end is connected to the low-temperature and high-pressure hydrogen storage tank unit. The first cold flow passes through the secondary regenerator and the regenerator in sequence and is cooled by the low-temperature refrigerant. Then, after being cooled and reduced in pressure by the throttling element, a portion of the refrigerant is diverted to pre-cool the low-temperature and high-pressure hydrogen storage tank.

[0035] This application adopts the above technical solution, and its beneficial effects are as follows:

[0036] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the present application includes: a hydrogen boosting unit, a reverse Brayton cycle refrigeration unit and a low-temperature and high-pressure hydrogen storage tank unit. The hydrogen boosting unit includes a multi-stage hydrogen compressor and a first aftercooler. The multi-stage hydrogen compressor is used to boost the hydrogen to a certain optimized storage pressure. The reverse Brayton cycle refrigeration unit is a reverse Brayton cycle, which includes a compressor, a second aftercooler, a regenerator and an expander. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the present application has the advantages of high hydrogen storage density, high hydrogen cooling efficiency, no need for normal-parahydrogen conversion, adaptability to large-scale hydrogen storage, and convenient acquisition and replenishment of working fluids. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 Schematic diagram of a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 1 of the present invention.

[0039] Figure 2 Schematic diagrams of two forms of expansion work recovery of the expander provided in Example 1 of the present invention.

[0040] Figure 3 Schematic diagrams of two variations of the expander provided in Example 1 of the present invention.

[0041] Figure 4 Schematic diagram of a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 2 of the present invention.

[0042] Figure 5 Schematic diagram of a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 3 of the present invention.

[0043] Figure 6 Schematic diagram of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle provided in Example 4 of the present invention.

[0044] Figure 7 Schematic diagram of a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 5 of the present invention.

[0045] Figure 8 Schematic diagram of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle provided in Example 6 of the present invention.

[0046] Figure 9Schematic diagram of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle provided in Example 7 of the present invention.

[0047] Figure 10 Schematic diagram of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle provided in Example 8 of the present invention.

[0048] Figure 11 Schematic diagram of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle provided in Example 9 of the present invention. DETAILED DESCRIPTION

[0049] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0050] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0052] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0053] Example 1

[0054] See also Figure 1 , which is a schematic diagram of the structure of a low-temperature, high-pressure hydrogen storage system based on a reverse Brayton cycle according to an embodiment of the present application, comprising: a hydrogen booster unit 1, a reverse Brayton cycle refrigeration unit 2, and a low-temperature, high-pressure hydrogen storage tank unit 3. The specific structure of each component is described in detail below.

[0055] The hydrogen boosting unit 1 includes a multi-stage hydrogen compressor 101 and a first aftercooler 102. The multi-stage hydrogen compressor 101 boosts the hydrogen to a certain optimized storage pressure, which includes but is not limited to 10-100 MPa.

[0056] The reverse Brayton cycle refrigeration unit 2 is a reverse Brayton cycle, which includes a compressor 201 , a second aftercooler 202 , a regenerator 203 and an expander 204 .

[0057] In this embodiment, the refrigerant may be a mixture of one or more of nitrogen, argon, methane, R14, ethylene, helium, neon, and hydrogen.

[0058] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 1 operates as follows:

[0059] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the regenerator 203 and is cooled by the low-temperature refrigerant. It then enters the expander 204 for cooling and pressure reduction, enters the regenerator 203 to provide cooling, and then returns to the compressor 201 to complete the cycle.

[0060] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and enters the regenerator 203 and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen; the low-temperature high-pressure hydrogen enters the low-temperature high-pressure hydrogen storage tank unit 3.

[0061] In this embodiment, the low-temperature and high-pressure hydrogen storage tank unit 3 includes a metal lining 303, a composite material layer coated on the surface of the metal lining 303, an insulating layer 302 arranged on the metal lining 303, and a shell 301 arranged on the insulating layer 302. An inlet valve 304 and an outlet valve 305 are also installed on the shell 301.

[0062] Low-temperature and high-pressure hydrogen enters the metal lining 303 of the low-temperature and high-pressure hydrogen storage tank unit 3 for storage. The insulation layer 302 is used to maintain the low-temperature state of the metal lining 303. The inlet valve 304 and the outlet valve 305 are used to control the filling and discharge of low-temperature and high-pressure hydrogen.

[0063] See also Figure 2 , which are schematic diagrams of two forms of expansion work recovery of the expander provided in this embodiment 1.

[0064] In this embodiment, the expander 204 transmits the expansion work to the compressor 201 in the form of electricity; alternatively, a supercharger turbocharger 211 and an aftercooler 212 are provided before the compressor, and the expander 204 transmits the expansion work to the compressor 201 via the aftercooler 212 and the supercharger turbocharger 211. Alternatively, the compressor 201 and the expander 204 are coaxially arranged to recover the expansion work.

[0065] See also Figure 3 , which are two variations of the expander provided in this embodiment.

[0066] In this embodiment, the expander 204 includes multiple stages of expander units arranged in series to prevent excessive rotation speed caused by excessive enthalpy drop of a single expander, thereby ensuring the reliability of the expander unit.

[0067] In this embodiment, the expander 204 includes a plurality of expander units arranged in parallel, which is suitable for applications requiring large cooling capacity.

[0068] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 1 of the present invention compresses hydrogen at room temperature, performs distributed cooling, and stores hydrogen at low temperature.

[0069] Example 2

[0070] See also Figure 4 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 2 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0071] The difference from Example 1 is that it further includes an evaporator 213, wherein:

[0072] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the regenerator 203 and is cooled by the low-temperature refrigerant. After that, it enters the expander 204 for cooling and pressure reduction, and then enters the evaporator 213 to cool the high-pressure refrigerant before entering the regenerator 203.

[0073] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and enters the regenerator 203 and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen enters the low-temperature and high-pressure hydrogen storage tank unit 3 through the evaporator 213.

[0074] Other working methods can refer to Example 1 and will not be described in detail here.

[0075] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 2 of the present invention can further reduce the temperature of the high-pressure hydrogen and improve the cooling performance by adding the evaporator 213.

[0076] Example 3

[0077] See also Figure 5 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 3 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0078] The difference from Example 1 is that the regenerator 203 includes a first heat exchanger 203a and a second heat exchanger 203b, wherein:

[0079] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the regenerator 203a and is cooled by the low-temperature refrigerant. It then enters the expander 204 to be cooled and decompressed to form a first low-temperature fluid and a second low-temperature fluid.

[0080] The first stream of low-temperature fluid returns to the compressor 201 through the first heat exchanger 203a to complete the cycle, and the second stream of low-temperature fluid returns to the compressor 201 through the second heat exchanger 203b to complete the cycle.

[0081] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and enters the second heat exchanger 203b and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0082] It can be understood that the above embodiment is based on the basic configuration and innovates the splitting of the low-temperature cold fluid flowing out of the expander 204. One stream and the high-pressure refrigeration fluid are in the heat exchanger 203a, and the other stream and the high-pressure hydrogen are in the heat exchanger 203b. The two heat exchangers can be selected separately, and a high-pressure resistant heat exchanger can be selected for 203b.

[0083] Furthermore, an evaporator may be added to the tail end of the expander 204 according to actual needs. For details, please refer to Example 2 to improve the cooling performance of the entire system.

[0084] The working method can be referred to Example 1 and Example 2, which will not be described in detail here.

[0085] The low-temperature refrigerant is divided into streams, and the high-pressure and low-pressure heat exchange flow paths are designed and manufactured separately, thereby reducing the overall structural weight and manufacturing cost of the reverse Brayton cycle refrigeration unit regenerator.

[0086] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 3 of the present invention can simultaneously fill and cool multiple sets of storage tanks to meet the needs of large-scale hydrogen storage.

[0087] Example 4

[0088] See also Figure 6 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 4 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0089] The difference from Example 1 is that it also includes a pre-cooling cycle unit, which includes a pre-cooling unit 206 and a pre-cooling heat exchanger 205. The pre-cooling unit 206 is used to provide cooling for the pre-cooling heat exchanger 205. The refrigerant and high-pressure hydrogen are cooled by the pre-cooling unit in the pre-cooling heat exchanger 205. The pre-cooling unit 206 can adopt a configuration such as a vapor compression refrigeration cycle, an absorption refrigeration cycle, or a commercial chiller.

[0090] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202 , and then enters the regenerator 203 after passing through the precooling heat exchanger 205 .

[0091] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and then enters the regenerator 203.

[0092] Other working methods can refer to Example 1 and will not be described in detail here.

[0093] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 4 of the present invention improves the system's ability to adapt to higher ambient temperatures and reduces the total energy consumption of high-pressure hydrogen cooling by adopting a pre-cooling cycle.

[0094] Example 5

[0095] See also Figure 7 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 5 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0096] The difference from Example 1 is that there is at least one hydrogen boosting unit 1 and they are connected in series.

[0097] For example, this embodiment separates the compressor 201 and second aftercooler 202 in the reverse Brayton cycle into two stages of compression, providing a first-stage compressor 201a and second aftercooler 202a, and a second-stage compressor 201b and second aftercooler 202b. Similarly, referring to Examples 2 and 3, the addition of a pre-cooling cycle and a terminal evaporator can be used to improve system efficiency.

[0098] Other working methods can refer to Example 1 and will not be described in detail here.

[0099] The low-temperature, high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 5 of the present invention, through the use of two-stage compression, can reduce compressor power consumption, improve the system's energy efficiency ratio, achieve higher refrigeration efficiency, reduce compressor exhaust temperature, extend the equipment's service life and maintenance cycle, and improve system reliability and stability.

[0100] Example 6

[0101] See also Figure 8 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 6 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0102] The difference from Example 1 is that it further includes a first-stage expander 207 , a first-stage regenerator 209 and a second-stage regenerator 208 .

[0103] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the first regenerator 209 to be cooled by the low-temperature refrigerant. Then, it enters the first expander 207 for cooling and decompression, and then enters the regenerator 203 to be cooled by the low-temperature refrigerant. Then, it enters the expander 204 for cooling and decompression, and then enters the regenerator 203 to provide cooling and reheating, and then returns to the compressor 201 through the second regenerator 208 and the first regenerator 209 to complete the cycle.

[0104] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and then passes through the first-stage regenerator 209, the second-stage regenerator 208 and the regenerator 203 in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0105] Other working methods can refer to Example 1 and will not be described in detail here.

[0106] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the sixth embodiment of the present invention adopts multi-stage expansion to reduce the total temperature difference and improve efficiency.

[0107] Example 7

[0108] See also Figure 9 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 7 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0109] The difference from Example 1 is that it further includes a first-stage expander 207 , a first-stage regenerator 209 and a second-stage regenerator 208 .

[0110] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the primary regenerator 209 and is cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow.

[0111] The first cold flow passes through the secondary regenerator 208 and the regenerator 203 in sequence and is cooled by the low-temperature refrigerant, then enters the expander 204 for cooling and decompression, and then enters the regenerator 203 to provide cooling capacity for reheating and flows out of the low-temperature and low-pressure refrigerant, and is mixed with the low-temperature and low-pressure refrigerant flowing out of the second cold flow after cooling and decompression through the primary expander 207. The formed mixed low-temperature and low-pressure refrigerant then passes through the secondary regenerator 208 and the primary regenerator 209 in sequence and then returns to the compressor 201 to complete the cycle;

[0112] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and then passes through the first-stage regenerator 209, the second-stage regenerator 208 and the regenerator 203 in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0113] It is understandable that, according to actual needs, a pre-cooling cycle may be provided at the regenerator 208 or an evaporator may be provided after the expander 204 to cool the high-pressure hydrogen.

[0114] Other working methods can refer to Example 1 and will not be described in detail here.

[0115] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 7 of the present invention adopts multi-stage expansion to reduce the total temperature difference and improve efficiency.

[0116] Example 8

[0117] See also Figure 10 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 8 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0118] The difference from Example 1 is that the expander is replaced by a throttling element 214 , and the low-temperature and high-pressure hydrogen storage system further includes a first-stage expander 207 , a first-stage regenerator 209 and a second-stage regenerator 208 .

[0119] The refrigerant is compressed by the compressor 201 and enters the second aftercooler 202. After being cooled by the second aftercooler 202, it enters the primary regenerator 209 and is cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow.

[0120] The first cold flow passes through the secondary regenerator 208 and the regenerator 203 in sequence and is cooled by the low-temperature refrigerant. It then enters the throttling element 214 for cooling and decompression, and then enters the regenerator 203 to provide cooling capacity for reheating and flows out as a low-temperature, low-pressure refrigerant. It is mixed with the low-temperature, low-pressure refrigerant that flows out after the second cold flow passes through the primary expander 207 for cooling and decompression. The resulting mixed low-temperature, low-pressure refrigerant then passes through the secondary regenerator 208 and the primary regenerator 209 in sequence and then returns to the compressor 201 to complete the cycle.

[0121] The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor 101 to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler 102 and then passes through the first-stage regenerator 209, the second-stage regenerator 208 and the regenerator 203 in sequence and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

[0122] Other working methods can refer to Example 1 and will not be described in detail here.

[0123] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned Example 8 of the present invention adopts multi-stage expansion to reduce the total temperature difference and improve efficiency.

[0124] Example 9

[0125] See also Figure 11 , which is a low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in Example 9 of the present application. For the convenience of explanation, only the relevant drawings are described below.

[0126] The difference from Example 8 is that it also includes a first inlet valve 306, one end of the first inlet valve 306 is connected to the throttling element 214 and the other end is connected to the low-temperature and high-pressure hydrogen storage tank unit 3. The first cold flow passes through the secondary regenerator 208 and the regenerator 203 in sequence and is cooled by the low-temperature refrigerant, and then a part of the refrigerant is diverted to pre-cool the low-temperature and high-pressure hydrogen storage tank 3 after being cooled and reduced in pressure by the throttling element 214.

[0127] It can be understood that in this embodiment 9, a portion of liquid nitrogen is diverted after the throttling element 214 to be used for residual cooling of the low-temperature and high-pressure hydrogen storage tank, and at the same time, nitrogen raw material replenishment before the compressor 201 is increased. A cooling jacket is set on the low-temperature and high-pressure hydrogen storage tank to pre-cool the low-temperature and high-pressure hydrogen storage tank to the target hydrogen storage temperature.

[0128] Other working methods can refer to Example 8 and will not be described in detail here.

[0129] The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle provided in the above-mentioned embodiment 9 of the present invention uses liquid nitrogen as the refrigerant in the reverse Brayton cycle refrigeration unit to cool the low-temperature and high-pressure hydrogen storage tank to complete the pre-cooling of the tank body, with low energy consumption.

[0130] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0131] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. A low-temperature and high-pressure hydrogen storage system based on a reverse Brayton cycle, characterized in that: include: A hydrogen boosting unit (1), a reverse Brayton cycle refrigeration unit (2) and a low-temperature and high-pressure hydrogen storage tank unit (3), wherein: The hydrogen boosting unit (1) comprises a multi-stage hydrogen compressor (101) and a first aftercooler (102), wherein the multi-stage hydrogen compressor (101) is used to boost the hydrogen to a certain optimized storage pressure, wherein the certain optimized storage pressure includes 10-100 MPa, and the hydrogen boosting unit (1) is at least one and is connected in series. The reverse Brayton cycle refrigeration unit (2) is a reverse Brayton cycle, comprising a compressor (201), a second aftercooler (202), a regenerator (203), and an expander (204), wherein the expander (204) comprises a multi-stage series-arranged expander unit or a plurality of parallel-arranged expander units; The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the regenerator (203) and is cooled by the low-temperature refrigerant. The refrigerant then enters the expander (204) to reduce temperature and pressure, enters the regenerator (203) to provide cooling capacity, and then returns to the compressor (201) to complete the cycle. The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then enters the regenerator (203) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen enters the low-temperature high-pressure hydrogen storage tank unit (3). Also included is an evaporator (213); wherein: The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the regenerator (203) and is cooled by the low-temperature refrigerant. The refrigerant then enters the expander (204) to reduce temperature and pressure, enters the evaporator (213) to cool the high-pressure refrigerant, and then enters the regenerator (203). The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then enters the regenerator (203) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen. The low-temperature high-pressure hydrogen enters the low-temperature high-pressure hydrogen storage tank unit (3) through the evaporator (213).

2. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: The expander (204) transmits the expansion work to the compressor (201) in the form of electricity; or a supercharger turbocharger (211) and a third aftercooler (212) are arranged before the compressor, and the expander (204) transmits the expansion work to the compressor (201) via the third aftercooler (212) and the supercharger turbocharger (211); or the compressor (201) and the expander (204) are coaxially arranged to recover the expansion work.

3. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: The refrigerant can be a mixture of one or more of nitrogen, argon, methane, R14, ethylene, helium, neon, and hydrogen.

4. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: The regenerator (203) comprises a first heat exchanger (203a) and a second heat exchanger (203b); The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the regenerator (203) and is cooled by the low-temperature refrigerant. The refrigerant then enters the expander (204) to be cooled and decompressed to form a first low-temperature fluid and a second low-temperature fluid. The first stream of low-temperature fluid returns to the compressor (201) through the first heat exchanger (203a) to complete the cycle, and the second stream of low-temperature fluid returns to the compressor (201) through the second heat exchanger (203b) to complete the cycle; The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then enters the second heat exchanger (203b) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

5. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: It also includes a pre-cooling circulation unit, the pre-cooling circulation unit including a pre-cooling unit (206) and a pre-cooling heat exchanger (205), the pre-cooling unit (206) is used to provide cooling capacity to the pre-cooling heat exchanger (205); The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202), and then enters the regenerator (203) after passing through the precooling heat exchanger (205); The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen, and the high-pressure hydrogen is cooled by the first aftercooler (102) and then enters the regenerator (203).

6. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: It also includes a first-stage expander (207), a first-stage regenerator (209), and a second-stage regenerator (208); The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the first regenerator (209) and is cooled by the low-temperature refrigerant. The refrigerant then enters the first expander (207) for temperature reduction and pressure reduction, enters the regenerator (203) and is cooled by the low-temperature refrigerant. The refrigerant then enters the expander (204) for temperature reduction and pressure reduction, enters the regenerator (203) to provide cooling capacity, and then returns to the compressor (201) through the second regenerator (208) and the first regenerator (209) to complete the cycle. The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then sequentially passes through the first regenerator (209), the second regenerator (208) and the regenerator (203) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

7. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: It also includes a first-stage expander (207), a first-stage regenerator (209), and a second-stage regenerator (208); The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the first regenerator (209) and is cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow. The first cold flow passes through the secondary regenerator (208) and the regenerator (203) in sequence and is cooled by the low-temperature refrigerant, then enters the expander (204) for cooling and depressurization, and then enters the regenerator (203) to provide cooling capacity, reheats, and flows out of the low-temperature, low-pressure refrigerant, and is mixed with the low-temperature, low-pressure refrigerant that flows out of the second cold flow after cooling and depressurizing the first-stage expander (207). The formed mixed low-temperature, low-pressure refrigerant then passes through the secondary regenerator (208) and the first-stage regenerator (209) in sequence and then returns to the compressor (201) to complete the cycle; The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then sequentially passes through the first regenerator (209), the second regenerator (208) and the regenerator (203) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

8. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 1, characterized in that: The expander unit is replaced with a throttling element (214), and the low-temperature and high-pressure hydrogen storage system further includes a first-stage expander (207), a first-stage regenerator (209), and a second-stage regenerator (208); The refrigerant is compressed by the compressor (201) and enters the second aftercooler (202). After being cooled by the second aftercooler (202), the refrigerant enters the first regenerator (209) and is cooled by the low-temperature refrigerant to form a first cold flow and a second cold flow. The first cold flow passes through the secondary regenerator (208) and the regenerator (203) in sequence and is cooled by the low-temperature refrigerant, then enters the throttling element (214) to reduce temperature and pressure, and then enters the regenerator (203) to provide cooling capacity and reheat and flow out of the low-temperature and low-pressure refrigerant, and is mixed with the low-temperature and low-pressure refrigerant that flows out after the second cold flow is cooled and reduced pressure by the primary expander (207). The formed mixed low-temperature and low-pressure refrigerant then passes through the secondary regenerator (208) and the primary regenerator (209) in sequence and then returns to the compressor (201) to complete the cycle; The low-pressure raw hydrogen is pressurized by the multi-stage hydrogen compressor (101) to form high-pressure hydrogen. The high-pressure hydrogen is cooled by the first aftercooler (102) and then sequentially passes through the first regenerator (209), the second regenerator (208) and the regenerator (203) and is cooled by the refrigerant to the target hydrogen storage temperature to form low-temperature high-pressure hydrogen.

9. The low-temperature and high-pressure hydrogen storage system based on the reverse Brayton cycle according to claim 8, characterized in that: The invention also includes a first inlet valve (306), one end of which is connected to the throttling element (214) and the other end of which is connected to the low-temperature and high-pressure hydrogen storage tank unit (3). The first cold flow passes through the secondary regenerator (208) and the regenerator (203) in sequence and is cooled by the low-temperature refrigerant. Then, after being cooled and reduced in pressure by the throttling element (214), a portion of the refrigerant is diverted to pre-cool the low-temperature and high-pressure hydrogen storage tank unit (3).

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