A hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration

Abstract

The present invention discloses a hydrogen liquefaction system with nitrogen and neon cycle expansion refrigeration, comprising: a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a subcooler, a first nitrogen turbine expander, a second nitrogen turbine expander, a first neon turbine expander, a second neon turbine expander, a hydrogen turbine expander, a hydrogen cryogenic purifier, an ejector, and a liquid hydrogen storage tank. The production capacity of the above hydrogen liquefaction system can be greatly increased to 30 tons per day, which is three times that of the prior art, and will more effectively promote the large-scale application of hydrogen. The comprehensive energy consumption of the existing 10-ton-per-day hydrogen liquefaction system is 13 - 13.5 KWh / kg of liquid hydrogen, while the comprehensive energy consumption of the 30-ton-per-day hydrogen liquefaction system of the present invention is 10 KWh / kg of liquid hydrogen, with lower unit energy consumption and lower cost.

Description

Technical Field

[0001] The present invention relates to the field of energy production equipment, and particularly to an efficient and energy-saving hydrogen liquefaction system. Background Art

[0002] Currently, the largest domestic independent hydrogen liquefaction technology on the market is the 10-ton-per-day hydrogen liquefaction process technology. This liquefaction process uses hydrogen cycle expansion refrigeration to obtain the cold energy required for liquefying hydrogen. Hydrogen compression is required in hydrogen cycle expansion refrigeration. However, since hydrogen is not easily compressed, the cost and energy consumption of the compressor are relatively large. With the further development of the hydrogen energy market, the demand for larger-scale hydrogen liquefaction process technology is also increasing. The largest scale of the existing domestic independent hydrogen liquefaction process technology is 10 tons per day, which cannot meet the future large-scale development of hydrogen energy. There is an urgent need for a hydrogen liquefaction system with higher production capacity and lower energy consumption. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a hydrogen liquefaction system with nitrogen and neon cycle expansion refrigeration that has higher production capacity and lower energy consumption.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: A hydrogen liquefaction system with nitrogen and neon cycle expansion refrigeration, characterized by comprising: a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a subcooler, a first nitrogen turbine expander, a second nitrogen turbine expander, a first neon turbine expander, a second neon turbine expander, a hydrogen turbine expander, a hydrogen cryogenic purifier, an ejector, and a liquid hydrogen storage tank. An A1 passage, an A2 passage, an A3 passage, an A4 passage, an A5 passage, and an A6 passage are provided in the first heat exchanger; a B1 passage, a B2 passage, a B3 passage, a B4 passage, a B5 passage, and a B6 passage are provided in the second heat exchanger; a C1 passage, a C2 passage, a C3 passage, a C4 passage, a C5 passage, and a C6 passage are provided in the third heat exchanger; a D1 passage, a D2 passage, a D3 passage, and a D4 passage are provided in the fourth heat exchanger; an E1 passage, an E2 passage, an E3 passage, and an E4 passage are provided in the fifth heat exchanger; an F1 passage and an F2 passage are provided in the subcooler. A normal - para hydrogen conversion catalyst is filled in the C2 passage and the F1 passage. One end of the hydrogen pipeline is connected to the inlet of the A1 passage, the outlet of the A1 passage is connected to the inlet of the B1 passage through a pipeline, the outlet of the B1 passage is connected to the inlet of the C1 passage through a pipeline, the outlet of the C1 passage is connected to the inlet of the hydrogen cryogenic purifier through a pipeline, the outlet of the hydrogen cryogenic purifier is connected to the inlet of the C2 passage through a pipeline, the outlet of the C2 passage is connected to the inlet of the D1 passage through a pipeline, the outlet of the D1 passage is connected to the expansion inlet of the hydrogen turbine expander through a pipeline, the expansion outlet of the hydrogen turbine expander is connected to the inlet of the E1 passage through a pipeline, the outlet of the E1 passage is connected to the inlet of the ejector through a pipeline, the outlet of the ejector is connected to the inlet of the F1 passage through a pipeline, the outlet of the F1 passage is connected to the liquid hydrogen storage tank through a first pipeline, a first throttle valve is connected in series on the first pipeline, the outlet of the F1 passage is also connected to the inlet of the F2 passage through a second pipeline, a second throttle valve is connected in series on the second pipeline, the outlet of the F2 passage is connected to the inlet of the E2 passage through a pipeline, the outlet of the E2 passage is connected to the inlet of the D2 passage through a pipeline, the outlet of the D2 passage is connected to the inlet of the C3 passage through a pipeline, the outlet of the C3 passage is connected to the inlet of the B2 passage through a pipeline, the outlet of the B2 passage is connected to the inlet of the A2 passage through a pipeline, the outlet of the A2 passage is connected to the inlet of the first centrifugal compressor through a pipeline, the outlet of the first centrifugal compressor is connected to the inlet of the first circulating water cooler through a pipeline, the outlet of the first circulating water cooler is connected to the hydrogen pipeline through a pipeline, the expansion outlet of the first nitrogen turbine expander is connected to the inlet of the B3 passage through a pipeline, the outlet of the B3 passage is connected to the inlet of the A3 passage through a pipeline, the outlet of the A3 passage is connected to the inlet of the second centrifugal compressor through a pipeline, the outlet of the second centrifugal compressor is connected to the inlet of the second circulating water cooler through a pipeline, the outlet of the second circulating water cooler is connected to the boost braking inlet of the second nitrogen turbine expander through a pipeline,The expansion outlet of the second nitrogen turbine expander is connected to the inlet of the C4 passage through a pipeline, the outlet of the C4 passage is connected to the inlet of the B3 passage through a pipeline, the booster braking outlet of the second nitrogen turbine expander is connected to the inlet of the third circulating water cooler through a pipeline, the outlet of the third circulating water cooler is connected to the booster braking inlet of the first nitrogen turbine expander through a pipeline, the booster braking outlet of the first nitrogen turbine expander is connected to the inlet of the fourth circulating water cooler through a pipeline, the outlet of the fourth circulating water cooler is connected to the inlet of the A4 passage through a pipeline, the outlet of the A4 passage is respectively connected to the expansion inlet of the first nitrogen turbine expander and the inlet of the B4 passage through pipelines, the outlet of the B4 passage is connected to the expansion inlet of the second nitrogen turbine expander through a pipeline, the expansion outlet of the first neon turbine expander is connected to the inlet of the D3 passage through a pipeline, the outlet of the D3 passage is connected to the inlet of the C5 passage through a pipeline, the outlet of the C5 passage is connected to the inlet of the B5 passage through a pipeline, the outlet of the B5 passage is connected to the inlet of the A5 passage through a pipeline, the outlet of the A5 passage is connected to the inlet of the third centrifugal compressor through a pipeline, the outlet of the third centrifugal compressor is connected to the inlet of the fifth circulating water cooler through a pipeline, the outlet of the fifth circulating water cooler is connected to the booster braking inlet of the first neon turbine expander through a pipeline, the booster braking outlet of the first neon turbine expander is connected to the inlet of the sixth circulating water cooler through a pipeline, the outlet of the sixth circulating water cooler is connected to the booster braking inlet of the second neon turbine expander through a pipeline, the expansion outlet of the second neon turbine expander is connected to the inlet of the E3 passage through a pipeline, the outlet of the E3 passage is connected to the inlet of the D3 passage through a pipeline, the booster braking outlet of the second neon turbine expander is connected to the inlet of the A6 passage through a pipeline, the outlet of the A6 passage is connected to the inlet of the B6 passage through a pipeline, the outlet of the B6 passage is connected to the inlet of the C6 passage through a pipeline, the outlet of the C6 passage is connected to the inlet of the D4 passage through a pipeline, the outlet of the D4 passage is respectively connected to the inlet of the E4 passage and the expansion inlet of the first neon turbine expander through pipelines, the outlet of the E4 passage is connected to the expansion inlet of the second neon turbine expander through a pipeline, the BOG outlet on the liquid hydrogen storage tank is connected to the throat inlet of the ejector through a pipeline.,

[0005] Further, in the above-mentioned hydrogen liquefaction system with nitrogen and neon cycle expansion refrigeration: The hydrogen turbine expander uses a gas bearing to support the main shaft in the expander, and the gas bearing uses hydrogen as the working gas.

[0006] Further, in the above-mentioned hydrogen liquefaction system with nitrogen and neon cycle expansion refrigeration: The D1 passage and the E1 passage are also filled with a normal - para hydrogen conversion catalyst.

[0007] Further, for the hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration described above, where: the first heat exchanger, the second heat exchanger, the third heat exchanger, the turbine expansion parts of the first nitrogen turbine expander, the turbine expansion parts of the second nitrogen turbine expander, and the hydrogen low-temperature purifier are all located in the precooling cold box, and the precooling cold box is insulated and cooled by perlite; the fourth heat exchanger, the fifth heat exchanger, the subcooler, the turbine expansion parts of the first neon turbine expander, the turbine expansion parts of the second neon turbine expander, and the turbine expansion parts of the hydrogen turbine expander are all located in the liquefaction cold box, and the liquefaction cold box is cooled by dynamic vacuum.

[0008] Further, for the hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration described above, where: a third throttle valve is connected in series on the pipeline between the outlet of the A4 passage and the expansion inlet of the first nitrogen turbine expander, and a fourth throttle valve is connected in series on the pipeline between the BOG outlet on the liquid hydrogen storage tank and the throat inlet of the ejector.

[0009] The advantages of the present invention are as follows: By using nitrogen cyclic expansion refrigeration to perform three-stage precooling on the raw hydrogen, using neon cyclic expansion refrigeration with stronger refrigeration capacity and lower energy consumption to perform two-stage cooling on the raw hydrogen, using a hydrogen turbine expander to adiabatically expand and do work to cool the raw hydrogen, and using low-temperature reverse-flow hydrogen to cool the raw hydrogen, the production capacity of the hydrogen liquefaction system in the present invention can be greatly increased to 30 tons per day, and the production capacity is three times that of the prior art, which will more effectively promote the large-scale application of hydrogen. The comprehensive energy consumption of the existing 10-ton-per-day hydrogen liquefaction system is 13 - 13.5 KWh / kg of liquid hydrogen, while the comprehensive energy consumption of the 30-ton-per-day hydrogen liquefaction system of the present invention is 10 KWh / kg of liquid hydrogen, with lower unit energy consumption and lower cost. Description of the Drawings

[0010] Figure 1 It is a schematic structural diagram of the hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration described in the present invention. Detailed Embodiments

[0011] The present invention will be further described in detail below in conjunction with specific embodiments and the drawings.

[0012] As Figure 1As shown in the figure, a hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration includes: a first heat exchanger 1, a second heat exchanger 2, a third heat exchanger 3, a fourth heat exchanger 4, a fifth heat exchanger 5, a subcooler 6, a first nitrogen turbine expander 7, a second nitrogen turbine expander 8, a first neon turbine expander 9, a second neon turbine expander 10, a hydrogen turbine expander 71, a hydrogen cryogenic purifier 72, an ejector 73, and a liquid hydrogen storage tank 74. An A1 passage 11, an A2 passage 12, an A3 passage 13, an A4 passage 14, an A5 passage 15, and an A6 passage 16 are arranged in the first heat exchanger 1. A B1 passage 21, a B2 passage 22, a B3 passage 23, a B4 passage 24, a B5 passage 25, and a B6 passage 26 are arranged in the second heat exchanger 2. A C1 passage 31, a C2 passage 32, a C3 passage 33, a C4 passage 34, a C5 passage 35, and a C6 passage 36 are arranged in the third heat exchanger 3. A D1 passage 41, a D2 passage 42, a D3 passage 43, and a D4 passage 44 are arranged in the fourth heat exchanger 4. An E1 passage 51, an E2 passage 52, an E3 passage 53, and an E4 passage 54 are arranged in the fifth heat exchanger 5. An F1 passage 61 and an F2 passage 62 are arranged in the subcooler 6. A normal-to-parahydrogen conversion catalyst is filled in the C2 passage 32 and the F1 passage 61. One end of a hydrogen pipeline 88 is connected to the inlet of the A1 passage 11. The outlet of the A1 passage 11 is connected to the inlet of the B1 passage 21 through a pipeline. The outlet of the B1 passage 21 is connected to the inlet of the C1 passage 31 through a pipeline. The outlet of the C1 passage 31 is connected to the inlet of the hydrogen cryogenic purifier 72 through a pipeline. The outlet of the hydrogen cryogenic purifier 72 is connected to the inlet of the C2 passage 32 through a pipeline. The outlet of the C2 passage 32 is connected to the inlet of the D1 passage 41 through a pipeline. The outlet of the D1 passage 41 is connected to the expansion inlet of the hydrogen turbine expander 71 through a pipeline. The expansion outlet of the hydrogen turbine expander 71 is connected to the inlet of the E1 passage 51 through a pipeline. The outlet of the E1 passage 51 is connected to the inlet of the ejector 73 through a pipeline. The outlet of the ejector 73 is connected to the inlet of the F1 passage 61 through a pipeline. The outlet of the F1 passage 61 is connected to the liquid hydrogen storage tank 74 through a first pipeline 91. A first throttle valve 75 is connected in series on the first pipeline 91. The outlet of the F1 passage 61 is also connected to the inlet of the F2 passage 62 through a second pipeline 92. A second throttle valve 76 is connected in series on the second pipeline 92. The outlet of the F2 passage 62 is connected to the inlet of the E2 passage 52 through a pipeline. The outlet of the E2 passage 52 is connected to the inlet of the D2 passage 42 through a pipeline. The outlet of the D2 passage 42 is connected to the inlet of the C3 passage 33 through a pipeline. The outlet of the C3 passage 33 is connected to the inlet of the B2 passage 22 through a pipeline. The outlet of the B2 passage 22 is connected to the inlet of the A2 passage 12 through a pipeline. The outlet of the A2 passage 12 is connected to the inlet of a first centrifugal compressor 77 through a pipeline. The outlet of the first centrifugal compressor 77 is connected to the inlet of a first circulating water cooler 78 through a pipeline.The outlet of the first circulating water cooler 78 is connected to the hydrogen pipeline 88 through a pipeline. The expansion outlet of the first nitrogen turbine expander 7 is connected to the inlet of the B3 passage 23 through a pipeline. The outlet of the B3 passage 23 is connected to the inlet of the A3 passage 13 through a pipeline. The outlet of the A3 passage 13 is connected to the inlet of the second centrifugal compressor 81 through a pipeline. The outlet of the second centrifugal compressor 81 is connected to the inlet of the second circulating water cooler 82 through a pipeline. The outlet of the second circulating water cooler 82 is connected to the boosting braking inlet of the second nitrogen turbine expander 8 through a pipeline. The expansion outlet of the second nitrogen turbine expander 8 is connected to the inlet of the C4 passage 34 through a pipeline. The outlet of the C4 passage 34 is connected to the inlet of the B3 passage 23 through a pipeline. The boosting braking outlet of the second nitrogen turbine expander 8 is connected to the inlet of the third circulating water cooler 79 through a pipeline. The outlet of the third circulating water cooler 79 is connected to the boosting braking inlet of the first nitrogen turbine expander 7 through a pipeline. The boosting braking outlet of the first nitrogen turbine expander 7 is connected to the inlet of the fourth circulating water cooler 80 through a pipeline. The outlet of the fourth circulating water cooler 80 is connected to the inlet of the A4 passage 14 through a pipeline. The outlet of the A4 passage 14 is respectively connected to the expansion inlet of the first nitrogen turbine expander 7 and the inlet of the B4 passage 24 through pipelines. The outlet of the B4 passage 24 is connected to the expansion inlet of the second nitrogen turbine expander 8 through a pipeline. The expansion outlet of the first neon turbine expander 9 is connected to the inlet of the D3 passage 43 through a pipeline. The outlet of the D3 passage 43 is connected to the inlet of the C5 passage 35 through a pipeline. The outlet of the C5 passage 35 is connected to the inlet of the B5 passage 25 through a pipeline. The outlet of the B5 passage 25 is connected to the inlet of the A5 passage 15 through a pipeline. The outlet of the A5 passage 15 is connected to the inlet of the third centrifugal compressor 83 through a pipeline. The outlet of the third centrifugal compressor 83 is connected to the inlet of the fifth circulating water cooler 84 through a pipeline. The outlet of the fifth circulating water cooler 84 is connected to the boosting braking inlet of the first neon turbine expander 9 through a pipeline. The boosting braking outlet of the first neon turbine expander 9 is connected to the inlet of the sixth circulating water cooler 85 through a pipeline. The outlet of the sixth circulating water cooler 85 is connected to the boosting braking inlet of the second neon turbine expander 10 through a pipeline. The expansion outlet of the second neon turbine expander 10 is connected to the inlet of the E3 passage 53 through a pipeline. The outlet of the E3 passage 53 is connected to the inlet of the D3 passage 43 through a pipeline. The boosting braking outlet of the second neon turbine expander 10 is connected to the inlet of the A6 passage 16 through a pipeline. The outlet of the A6 passage 16 is connected to the inlet of the B6 passage 26 through a pipeline. The outlet of the B6 passage 26 is connected to the inlet of the C6 passage 36 through a pipeline. The outlet of the C6 passage 36 is connected to the inlet of the D4 passage 44 through a pipeline. The outlet of the D4 passage 44 is respectively connected to the inlet of the E4 passage 54 and the expansion inlet of the first neon turbine expander 9 through pipelines. The outlet of the E4 passage 54 is connected to the expansion inlet of the second neon turbine expander 10 through a pipeline.The BOG outlet on the liquid hydrogen storage tank 74 is connected to the throat inlet of the ejector 73 through a pipeline.

[0013] In this embodiment, the D1 passage 41 and the E1 passage 51 are also filled with a normal - para hydrogen conversion catalyst, so that the raw hydrogen can also undergo normal - para hydrogen conversion when passing through the D1 passage 41 and the E1 passage 51. The first heat exchanger 1, the second heat exchanger 2, the third heat exchanger 3, the turbine expansion part of the first nitrogen turbine expander 7, the turbine expansion part of the second nitrogen turbine expander 8, and the hydrogen low - temperature purifier 72 are all located in the precooling cold box 89, and the precooling cold box 89 is insulated and heat - insulated by perlite; the fourth heat exchanger 4, the fifth heat exchanger 5, the sub - cooler 6, the turbine expansion part of the first neon turbine expander 9, the turbine expansion part of the second neon turbine expander 10, and the turbine expansion part of the hydrogen turbine expander 71 are all located in the liquefaction cold box 90, and the liquefaction cold box 90 is heat - insulated by dynamic vacuum.

[0014] A third throttle valve 87 is connected in series on the pipeline between the outlet of the A4 passage 14 and the expansion inlet of the first nitrogen turbine expander 7, and a fourth throttle valve 86 is connected in series on the pipeline between the BOG outlet on the liquid hydrogen storage tank 74 and the throat inlet of the ejector 73.

[0015] The hydrogen turbine expander 71 uses a gas bearing to support the main shaft in the expander. The gas bearing uses hydrogen as the working gas. The hydrogen turbine expander 71 cannot use an oil bearing to support the main shaft because the oil in the oil bearing is likely to contaminate the raw hydrogen.

[0016] During operation, the raw hydrogen to be liquefied is produced by electrolytic hydrogen production. The purity of the raw hydrogen is greater than 99.999%, the pressure is 1.6 Mpa (A), and the temperature is ≤ 40°C. The raw hydrogen enters the A1 passage 11 in the first heat exchanger 1 through the hydrogen pipeline 88 for heat exchange precooling, reducing the temperature of the raw hydrogen to 290 K. Then the raw hydrogen enters the B1 passage 21 in the second heat exchanger 2 for heat exchange precooling, reducing the temperature of the raw hydrogen to 175 K. Next, the raw hydrogen enters the C1 passage 31 in the third heat exchanger 3 for heat exchange precooling, reducing the temperature of the raw hydrogen to 83 K. Then the raw hydrogen enters the hydrogen low-temperature purifier 72 to remove impurities. Next, the raw hydrogen enters the C2 passage 32 for ortho-para hydrogen conversion, making the concentration of para-hydrogen in the raw hydrogen reach 47%. Then the raw hydrogen enters the D1 passage 41 in the fourth heat exchanger 4 for heat exchange cooling, reducing the temperature of the raw hydrogen to 60 K. Next, the raw hydrogen goes to the hydrogen turbine expander 71 for turbine expansion. The raw hydrogen expands to 13 Bara, and the isentropic efficiency is ≥ 75%. The temperature of the raw hydrogen drops below 56.6 K. Then the raw hydrogen enters the E1 passage 51 in the fifth heat exchanger 5 for heat exchange cooling, reducing the temperature of the raw hydrogen to 32 K. At this time, the raw hydrogen is converted into saturated liquid hydrogen, and the saturated liquid hydrogen is relatively easy to vaporize. Next, the raw hydrogen enters the ejector 73 for throttling expansion, reducing the temperature of the raw hydrogen to 23.5 K. Then the raw hydrogen enters the F1 passage 61 in the subcooler 6 for heat exchange cooling, reducing the temperature of the raw hydrogen to 23 K. At the same time, ortho-para hydrogen conversion occurs in the F1 passage 61, making the concentration of para-hydrogen in the raw hydrogen reach more than 97%. Next, a part of the hydrogen in the raw hydrogen is throttled and expanded by the first throttle valve 75 to about 20.9 K and then enters the liquid hydrogen storage tank 74 for storage;

[0017] The remaining part of the raw hydrogen, as the reverse flow hydrogen, is throttled and expanded by the second throttle valve 76 to about 20.9 K and then enters the F2 passage 62 in the subcooler 6 as a refrigerant to provide cooling capacity for heat exchange. Then the reverse flow hydrogen enters the E2 passage 52 in the fifth heat exchanger 5 as a refrigerant to provide cooling capacity for heat exchange. Next, the reverse flow hydrogen enters the D2 passage 42 in the fourth heat exchanger 4 as a refrigerant to provide cooling capacity for heat exchange. Then the reverse flow hydrogen enters the C3 passage 33 in the third heat exchanger 3 as a refrigerant to provide cooling capacity for heat exchange. Next, the reverse flow hydrogen enters the B2 passage 22 in the second heat exchanger 2 as a refrigerant to provide cooling capacity for heat exchange. Then the reverse flow hydrogen enters the A2 passage 12 in the first heat exchanger 1 as a refrigerant to provide cooling capacity for heat exchange. At this time, the reverse flow hydrogen will be reheated to about 310 K. Next, the reverse flow hydrogen sequentially enters the first centrifugal compressor 77 and the first circulating water cooler 78, making the reverse flow hydrogen be pressurized to 16 Bara and the temperature be controlled at about 313 K. Then the reverse flow hydrogen flows into the hydrogen pipeline 88 and mixes with the raw hydrogen;

[0018] The low-temperature nitrogen with a temperature of 80K after adiabatic expansion and cooling in the second nitrogen turbine expander 8 enters the C4 passage 34 in the third heat exchanger 3 as a refrigerant to provide cooling capacity for heat exchange. Then, this part of the low-temperature nitrogen merges with the low-temperature nitrogen with a temperature of 142K after adiabatic expansion and cooling in the first nitrogen turbine expander 7 and enters the B3 passage 23 in the second heat exchanger 2 as a refrigerant to provide cooling capacity for heat exchange. Next, the low-temperature nitrogen enters the A3 passage 13 in the first heat exchanger 1 as a refrigerant to provide cooling capacity for heat exchange. Then, the nitrogen after temperature recovery enters the second centrifugal compressor 81 and the second circulating water cooler 82 in sequence, so that the nitrogen can be pressurized and cooled. Next, the nitrogen enters the booster braking section of the second nitrogen turbine expander 8 for braking and boosting. Then, the boosted nitrogen enters the third circulating water cooler 79 for cooling. Next, the nitrogen enters the booster braking section of the first nitrogen turbine expander 7 for braking and boosting. Then, the boosted nitrogen enters the fourth circulating water cooler 80 for cooling. Next, the nitrogen enters the A4 passage 14 in the first heat exchanger 1 for heat exchange and precooling. Then, a part of the nitrogen is throttled and expanded by the third throttle valve 87 to lower the temperature and then enters the first nitrogen turbine expander 7 for adiabatic expansion and cooling. Another part of the nitrogen enters the B4 passage 24 in the second heat exchanger 2 for heat exchange and precooling. Next, this part of the nitrogen enters the second nitrogen turbine expander 8 for adiabatic expansion and cooling;

[0019] The low-temperature neon gas with a temperature of 28K after adiabatic expansion and cooling in the second neon gas turbine expander 10 enters the E3 passage 53 in the fifth heat exchanger 5 as a refrigerant to provide cooling capacity for heat exchange. Then, this part of the low-temperature neon gas converges with the low-temperature neon gas with a temperature of 37K after adiabatic expansion and cooling in the first neon gas turbine expander 9 and enters the D3 passage 43 in the fourth heat exchanger 4 as a refrigerant to provide cooling capacity for heat exchange. Next, the low-temperature neon gas enters the C5 passage 35 in the third heat exchanger 3 as a refrigerant to provide cooling capacity for heat exchange. Then, the low-temperature neon gas enters the B5 passage 25 in the second heat exchanger 2 as a refrigerant to provide cooling capacity for heat exchange. Next, the low-temperature neon gas enters the A5 passage 15 in the first heat exchanger 1 as a refrigerant to provide cooling capacity for heat exchange. At this time, the neon gas is reheated to 310K. Then, the neon gas enters the third centrifugal compressor 83 and the fifth circulating water cooler 84 in sequence, so that the neon gas can be pressurized and cooled. Next, the neon gas enters the boosting braking section of the first neon gas turbine expander 9 for braking and boosting. Then, the neon gas enters the sixth circulating water cooler 85 for cooling. Next, the neon gas enters the boosting braking section of the second neon gas turbine expander 10 for braking and boosting to 30 Bara. Then, the neon gas enters the A6 passage 16 in the first heat exchanger 1 for heat exchange precooling. Next, the neon gas enters the B6 passage 26 in the second heat exchanger 2 for heat exchange precooling. Then, the neon gas enters the C6 passage 36 in the third heat exchanger 3 for heat exchange precooling. Next, the neon gas enters the D4 passage 44 in the fourth heat exchanger 4 for heat exchange precooling. Then, a part of the neon gas enters the first neon gas turbine expander 9 for adiabatic expansion and cooling, and another part of the neon gas enters the E4 passage 54 in the fifth heat exchanger 5 for heat exchange precooling. Next, this part of the neon gas enters the second neon gas turbine expander 10 for adiabatic expansion and cooling;

[0020] The BOG in the liquid hydrogen storage tank 74 is throttled and expanded by the fourth throttle valve 86 to cool down and then enters the ejector 73 to be mixed with the raw hydrogen. After this setting, the BOG can be recycled.

[0021] Due to the adoption of nitrogen cycle expansion refrigeration for three-stage precooling of the raw hydrogen, neon cycle expansion refrigeration with stronger refrigeration capacity and lower energy consumption for two-stage cooling of the raw hydrogen, the use of a hydrogen turbine expander to adiabatically expand and do work to cool down the raw hydrogen, and the use of low-temperature reverse-flow hydrogen to cool the raw hydrogen, the production capacity of the hydrogen liquefaction system in the present invention can be greatly increased to 30 tons per day, and the production capacity is 3 times that of the existing technology, which will more effectively promote the large-scale application of hydrogen.

[0022] The comprehensive energy consumption of the existing 10-ton-per-day hydrogen liquefaction system is 13 - 13.5 KWh / kg of liquid hydrogen, while the comprehensive energy consumption of the 30-ton-per-day hydrogen liquefaction system of the present invention is 10 KWh / kg of liquid hydrogen, with lower unit energy consumption and lower cost.

Claims

1. A hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration, characterized in that: Including: The first heat exchanger, the second heat exchanger, the third heat exchanger, the fourth heat exchanger, the fifth heat exchanger, the subcooler, the first nitrogen turbine expander, the second nitrogen turbine expander, the first neon turbine expander, the second neon turbine expander, the hydrogen turbine expander, the hydrogen cryogenic purifier, the ejector, the liquid hydrogen storage tank. In the first heat exchanger, there are A1 passage, A2 passage, A3 passage, A4 passage, A5 passage, and A6 passage; in the second heat exchanger, there are B1 passage, B2 passage, B3 passage, B4 passage, B5 passage, and B6 passage; in the third heat exchanger, there are C1 passage, C2 passage, C3 passage, C4 passage, C5 passage, and C6 passage; in the fourth heat exchanger, there are D1 passage, D2 passage, D3 passage, and D4 passage; in the fifth heat exchanger, there are E1 passage, E2 passage, E3 passage, and E4 passage; in the subcooler, there are F1 passage and F2 passage. The C2 passage and the F1 passage are filled with ortho-para hydrogen conversion catalyst. One end of the hydrogen pipeline is connected to the inlet of the A1 passage, the outlet of the A1 passage is connected to the inlet of the B1 passage through a pipeline, the outlet of the B1 passage is connected to the inlet of the C1 passage through a pipeline, the outlet of the C1 passage is connected to the inlet of the hydrogen cryogenic purifier through a pipeline, the outlet of the hydrogen cryogenic purifier is connected to the inlet of the C2 passage through a pipeline, the outlet of the C2 passage is connected to the inlet of the D1 passage through a pipeline, the outlet of the D1 passage is connected to the expansion inlet of the hydrogen turbine expander through a pipeline, the expansion outlet of the hydrogen turbine expander is connected to the inlet of the E1 passage through a pipeline, the outlet of the E1 passage is connected to the inlet of the ejector through a pipeline, the outlet of the ejector is connected to the inlet of the F1 passage through a pipeline, the outlet of the F1 passage is connected to the liquid hydrogen storage tank through the first pipeline, a first throttle valve is connected in series on the first pipeline, the outlet of the F1 passage is also connected to the inlet of the F2 passage through the second pipeline, a second throttle valve is connected in series on the second pipeline, the outlet of the F2 passage is connected to the inlet of the E2 passage through a pipeline, the outlet of the E2 passage is connected to the inlet of the D2 passage through a pipeline, the outlet of the D2 passage is connected to the inlet of the C3 passage through a pipeline, the outlet of the C3 passage is connected to the inlet of the B2 passage through a pipeline, the outlet of the B2 passage is connected to the inlet of the A2 passage through a pipeline, the outlet of the A2 passage is connected to the inlet of the first centrifugal compressor through a pipeline, the outlet of the first centrifugal compressor is connected to the inlet of the first circulating water cooler through a pipeline, the outlet of the first circulating water cooler is connected to the hydrogen pipeline through a pipeline, the expansion outlet of the first nitrogen turbine expander is connected to the inlet of the B3 passage through a pipeline, the outlet of the B3 passage is connected to the inlet of the A3 passage through a pipeline, the outlet of the A3 passage is connected to the inlet of the second centrifugal compressor through a pipeline, the outlet of the second centrifugal compressor is connected to the inlet of the second circulating water cooler through a pipeline, the outlet of the second circulating water cooler is connected to the boost braking inlet of the second nitrogen turbine expander through a pipeline, the expansion outlet of the second nitrogen turbine expander is connected to the inlet of the C4 passage through a pipeline, the outlet of the C4 passage is connected to the inlet of the B3 passage through a pipeline,The supercharging brake outlet of the second nitrogen turbine expander is connected to the inlet of the third circulating water cooler through a pipeline. The outlet of the third circulating water cooler is connected to the supercharging brake inlet of the first nitrogen turbine expander through a pipeline. The supercharging brake outlet of the first nitrogen turbine expander is connected to the inlet of the fourth circulating water cooler through a pipeline. The outlet of the fourth circulating water cooler is connected to the inlet of the A4 passage through a pipeline. The outlet of the A4 passage is respectively connected to the expansion inlet of the first nitrogen turbine expander and the inlet of the B4 passage through pipelines. The outlet of the B4 passage is connected to the expansion inlet of the second nitrogen turbine expander through a pipeline. The expansion outlet of the first neon turbine expander is connected to the inlet of the D3 passage through a pipeline. The outlet of the D3 passage is connected to the inlet of the C5 passage through a pipeline. The outlet of the C5 passage is connected to the inlet of the B5 passage through a pipeline. The outlet of the B5 passage is connected to the inlet of the A5 passage through a pipeline. The outlet of the A5 passage is connected to the inlet of the third centrifugal compressor through a pipeline. The outlet of the third centrifugal compressor is connected to the inlet of the fifth circulating water cooler through a pipeline. The outlet of the fifth circulating water cooler is connected to the supercharging brake inlet of the first neon turbine expander through a pipeline. The supercharging brake outlet of the first neon turbine expander is connected to the inlet of the sixth circulating water cooler through a pipeline. The outlet of the sixth circulating water cooler is connected to the supercharging brake inlet of the second neon turbine expander through a pipeline. The expansion outlet of the second neon turbine expander is connected to the inlet of the E3 passage through a pipeline. The outlet of the E3 passage is connected to the inlet of the D3 passage through a pipeline. The supercharging brake outlet of the second neon turbine expander is connected to the inlet of the A6 passage through a pipeline. The outlet of the A6 passage is connected to the inlet of the B6 passage through a pipeline. The outlet of the B6 passage is connected to the inlet of the C6 passage through a pipeline. The outlet of the C6 passage is connected to the inlet of the D4 passage through a pipeline. The outlet of the D4 passage is respectively connected to the inlet of the E4 passage and the expansion inlet of the first neon turbine expander through pipelines. The outlet of the E4 passage is connected to the expansion inlet of the second neon turbine expander through a pipeline. The BOG outlet on the liquid hydrogen storage tank is connected to the throat inlet of the ejector.

2. The hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration according to claim 1, wherein: The hydrogen turbine expander uses a gas bearing to support the main shaft in the expander, and the gas bearing uses hydrogen as the working gas.

3. A hydrogen liquefaction system using nitrogen and neon cyclic expansion refrigeration according to claim 1 or 2, characterized in that: The D1 passage and the E1 passage are also filled with a normal - para hydrogen conversion catalyst.

4. A hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration according to claim 1 or 2, characterized in that: The first heat exchanger, the second heat exchanger, the third heat exchanger, the turbine expansion section of the first nitrogen turbine expander, the turbine expansion section of the second nitrogen turbine expander, and the hydrogen low - temperature purifier are all located in the pre - cooling cold box, and the pre - cooling cold box is insulated by perlite powder; the fourth heat exchanger, the fifth heat exchanger, the sub - cooler, the turbine expansion section of the first neon turbine expander, the turbine expansion section of the second neon turbine expander, and the turbine expansion section of the hydrogen turbine expander are all located in the liquefaction cold box, and the liquefaction cold box is insulated by dynamic vacuum.

5. A hydrogen liquefaction system with nitrogen and neon cyclic expansion refrigeration according to claim 1 or 2, characterized in that: A throttle valve is connected in series on the pipeline between the outlet of the A4 passage and the expansion inlet of the first nitrogen turbine expander, and a throttle valve is connected in series on the pipeline between the BOG outlet on the liquid hydrogen storage tank and the throat inlet of the ejector.

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