Facility and method for hydrogen liquefaction

Abstract

The invention relates to a facility and a method for liquefying hydrogen, comprising a hydrogen circuit (2) having an upstream end (21) intended to be connected to a gaseous hydrogen source (23) and a downstream end (22) connected to at least one reservoir (8), the facility (1) comprising a cold box (18) containing a set of heat exchangers (3, 4, 5, 6) in heat exchange relationship with the hydrogen circuit (2), the facility (1) comprising cooling means in heat exchange relationship with at least part of the set of heat exchangers (3, 4), the facility (1) comprising a pipe (12) for collecting flash gas, the pipe being equipped with at least one upstream end connected to the reservoir (8) and / or to a tank (19) to be filled and a downstream end connected within the cold box (18) to the hydrogen circuit (2), said downstream end of the collection pipe (12) comprising, before its connection to the hydrogen circuit (2), a portion in heat exchange relationship with at least one heat exchanger (5, 6) of the set of heat exchangers (3, 4, 5, 6).

Description

[0001] This invention relates to facilities and methods for hydrogen liquefaction.

[0002] More specifically, the present invention relates to a facility for hydrogen liquefaction, the facility comprising a hydrogen loop having an upstream end designed to connect to a gaseous hydrogen source and a downstream end connected to at least one cryogenic storage tank for liquefied hydrogen in the facility, the cryogenic storage tank being provided with an extraction pipe configured to allow the supply of liquefied hydrogen to at least one storage tank, particularly a vehicle-mounted storage tank, to be filled; the facility comprising a cold box housing a series of heat exchangers that exchange heat with the hydrogen loop; the facility comprising a cooling device that exchanges heat with at least a portion of the series of heat exchangers; the cooling device... The device is configured to cool a hydrogen circuit. The cooling apparatus includes a cryogenic refrigerator having a refrigeration cycle for a circulating gas in its operating circuit, the circulating gas including at least one of hydrogen and helium. The operating circuit of the refrigerator includes a unit for compressing the circulating gas, a unit for cooling the circulating gas, a unit for expanding the circulating gas, and a unit for heating the circulating gas. The facility includes a conduit for recovering vaporized gas, the conduit having at least one upstream end connected to a storage tank and / or designed to be connected to a tank to be filled, and a downstream end connected to the hydrogen circuit.

[0003] In hydrogen liquefaction plants, evaporation (flash evaporation) can cause losses of up to 15% of production in systems used to fill tank trucks and storage tanks.

[0004] It should be understood that these evaporation losses can be recovered, reheated, recompressed after storage, and reinjected into the liquefier. This requires a system for loss recycling and a liquefier of sufficient size.

[0005] Another solution to minimize the generation of these vaporized gases is to supercool the resulting liquid hydrogen.

[0006] Known solutions for recovering these vaporized gases may have drawbacks as described below.

[0007] Because the pressure in the tanker truck can become lower than the pressure in the storage tank, there is no need to partially depressurize the tanker truck towards the facility's liquid storage tank via pressure equalization. Hydrogen is thus lost or sent to the recovery system described above.

[0008] During tank truck filling, it is possible that cold vapors may not be able to flow back to the facility's liquid storage tanks due to a lack of driving pressure. These vapors are easily lost.

[0009] Generally, the low temperatures present in the storage tank cannot compensate for all the additional heat generated by the tanker truck filling operation. This will cause an increase in the pressure of the storage tank and hydrogen loss.

[0010] The reflux temperature of the vapor from the tanker truck to be filled may be too high to be liquefied directly.

[0011] Pressure reduction is typically intermittent. The pipeline or conduit is heated between two tanker filling operations, so the gas returning to the liquefier is correspondingly hotter and more difficult to liquefy.

[0012] When the facility's liquid storage tanks are relatively small, the pressure in the tanks drops during the tanker filling operation. This makes it necessary to use a device to pressurize the liquid storage tanks, thereby vaporizing the liquid hydrogen that will later need to be reliquefied.

[0013] The purpose of this invention is to eliminate some or all of the disadvantages of the prior art as described above.

[0014] For this purpose, the essential feature of the facility according to the invention, and conforming to the general definition given in the foregoing preamble, is that the downstream end of the recovery pipeline is connected to the interior of the cold box, and before its connection with the hydrogen circuit, the downstream end includes a portion for heat exchange with at least one of the series of heat exchangers.

[0015] This allows the vaporized gas to flow back to one of the exchangers in the liquefier's cold box at a temperature compatible with that of the exchanger.

[0016] Since the power required for liquefying hydrogen is directly related to the pressure of gaseous hydrogen, this configuration allows for the liquefaction of the gas at relatively high pressures.

[0017] This configuration allows for maintaining the highest possible pressure (at the moment of liquefaction) in the heat exchanger cooling the recovered vaporized gas, while limiting the pressure increase required when the pressure in the storage tank or tanker supplying the vaporized gas is low.

[0018] This architecture has minimal impact on the capacity of the liquefier.

[0019] Furthermore, embodiments of the present invention may include one or more of the following features:

[0020] - The downstream end of the recovery pipeline includes a unit for expanding the vaporized gas flow, which is preferably located between the section that exchanges heat with at least one of the heat exchangers in the series and the connection to the hydrogen circuit.

[0021] - This series of heat exchangers includes multiple heat exchangers located in series between the upstream and downstream ends of the hydrogen loop, with the downstream end of the recovery pipeline connecting to the hydrogen loop located downstream of the first passage of the hydrogen loop in the final heat exchanger in series.

[0022] - The first pathway of the hydrogen circuit in the series-connected final heat exchanger includes a section for catalytic hydrogen production, which is configured to perform the conversion of at least a portion of the orthohydrogen into secondary hydrogen.

[0023] Downstream of this connection, the hydrogen loop provides a second pathway in the final heat exchanger;

[0024] - The second pathway in the final heat exchanger does not include a section for catalyzing orthohydrogen to secondary hydrogen;

[0025] Downstream of the second passage in the final heat exchanger, the hydrogen circuit includes a unit for expanding the hydrogen flow, the expansion unit including at least one of the following: an expansion valve, a turbine;

[0026] -Upstream of the connection with the hydrogen loop, the downstream end of the recovery pipeline includes a catalytic section configured to convert at least a portion of the secondary hydrogen into positive hydrogen.

[0027] - The downstream end of the recovery pipeline includes a bypass section and a series of valves configured to ensure that the vaporized gas flow passes through or does not pass through the catalytic section;

[0028] - The downstream end of the recovery pipeline includes a bypass section and a series of valves configured to ensure that the vaporized gas flow passes through or does not pass through the catalytic section;

[0029] - The recovery pipeline includes a compression unit, such as a cryogenic compressor;

[0030] - The recovery pipeline includes a first upstream end connected to a storage container and a second upstream end designed to connect to an onboard storage tank;

[0031] - The first and second upstream ends of the recycling pipeline are connected to the downstream end of the recycling pipeline via two different pipeline branches, and the compression unit is located in the pipeline branch at the second upstream end of the recycling pipeline.

[0032] The present invention also relates to a method for hydrogen liquefaction using a facility based on any of the above or below characteristics, the method comprising the steps of recovering vaporized gas via a recovery pipeline, cooling the recovered vaporized gas in a cold box, expanding the vaporized gas in the cold box, and mixing the expanded vaporized gas with a hydrogen stream to be cooled.

[0033] Based on other possible specific characteristics:

[0034] --The method includes at least one of the following steps: expanding a mixture of vaporized gas and hydrogen stream to be cooled, and expanding a mixture of vaporized gas and hydrogen stream to be cooled.

[0035] The present invention may also relate to any alternative methods or apparatus that include any combination of the features described above or below within the scope of the claims.

[0036] Other specific features and advantages will become apparent from the following description given with reference to the accompanying drawings, in which: Attached Figure Description

[0037] The invention will be better understood by reading the following description, which is provided by way of example only with reference to the accompanying drawings, in which:

[0038] [ Figure 1 This is a schematic partial view showing a first example of the structure and operation of a facility in a first configuration;

[0039] [ Figure 2 [This is a schematic partial view showing details of the structure and operation of such a facility according to a first possible embodiment;]

[0040] [ Figure 3 [This is a schematic partial view showing the first example of a facility in a second configuration;]

[0041] [ Figure 4 [This is a schematic partial view showing the first example of a facility in a third configuration;]

[0042] [ Figure 5 [This is a schematic partial view showing the first example of the facility in the fourth configuration;]

[0043] [ Figure 6 This is a schematic partial view showing the first example of the facility in the fifth configuration;

[0044] [ Figure 7 This is a schematic partial view showing the first example of the facility in the sixth configuration;

[0045] [ Figure 8 This is a schematic partial view showing the first example of the facility in the seventh configuration;

[0046] [ Figure 9 [This is a schematic partial view illustrating the structure and operation of a second embodiment in a first configuration;]

[0047] [ Figure 10 [This is a schematic partial view showing the second example of a facility in a second configuration;]

[0048] [ Figure 11 [This is a schematic partial view showing the second example of a facility in a third configuration;]

[0049] [ Figure 12[This is a schematic partial view showing the second example of the facility in the fourth configuration;]

[0050] [ Figure 13 [This is a schematic partial view showing the details of the structure and operation of another possible embodiment of the facility.] Detailed Implementation

[0051] Throughout the accompanying drawings, the same reference numerals refer to the same elements.

[0052] In this detailed description, the following embodiments are examples. Although the description relates to one or more embodiments, this does not mean that these features are applicable only to a single embodiment. Simple features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0053] [ Figure 1 The hydrogen liquefaction facility 1 shown in the image includes a hydrogen circuit 2 to be cooled / liquefied. The hydrogen circuit 2 has an upstream end 21 designed to be connected to a gaseous hydrogen source 23 and a downstream end 22 connected to at least one cryogenic storage tank 8 for liquefied hydrogen produced by the facility 1.

[0054] The gaseous hydrogen source 23 may include an electrolyzer, a gaseous hydrogen network, and / or any other means for producing hydrogen.

[0055] The cryogenic storage device 8 includes, for example, an insulated cryogenic storage tank under vacuum and is provided with at least one extraction pipe 11, which is configured to allow the supply of liquefied hydrogen to at least one storage tank 19 to be filled (e.g., a cryogenic storage tank 19 transported by tank truck).

[0056] Facility 1 includes a cold box 18 (i.e., an insulated, preferably sealed cryogenic enclosure) that houses at least a portion of the cryogenic liquefaction unit that forms liquefaction unit 31.

[0057] The cold box 18 specifically houses a series of heat exchangers 3, 4, 5, 6 for heat exchange, as well as the cold section of the hydrogen circuit 2 that exchanges heat with these heat exchangers 3, 4, 5, 6.

[0058] Facility 1 also includes a cooling device that exchanges heat with at least a portion of the heat exchangers 3, 4 in the series of heat exchangers, the device being configured to generate cold power for cooling the hydrogen circuit 2.

[0059] The cooling device preferably includes a cryogenic refrigerator 7, which has a refrigeration cycle for the circulating gas in its working circuit. In other words, the working circuit causes the circulating gas to undergo a thermodynamic cycle that brings the circulating gas to the cold end at a low temperature in order to provide cooling power.

[0060] The circulating gas includes at least one of the following, for example: hydrogen, helium. The operating circuit of the refrigeration unit 7 includes a unit 9 (one or more compressors connected in series and / or parallel) for compressing the circulating gas, units 3 and 4 for cooling the circulating gas, a unit 10 (turbine and / or expansion valve) for expanding the circulating gas, and units 6, 5, 4, and 3 for heating the circulating gas. The units for cooling and heating the gas may include heat exchangers, particularly counter-current heat exchangers, which ensure simultaneous heating and cooling of the circulating gas in the operating circuit.

[0061] Facility 1 also includes at least one conduit 12 for recovering vaporized gas. The recovery conduit 12 is provided with at least one upstream end connected to storage 8 and / or designed to be connected to storage tank 19 to be filled, and a downstream end connected to hydrogen loop 2, so as to recover the vaporized gas, liquefy it and mix it with the resulting liquid hydrogen.

[0062] like[ Figure 2 As shown in the diagram, the downstream end of the recovery pipe 12 is connected to the hydrogen circuit 2 inside the cold box 18. Furthermore, before the downstream end of the recovery pipe 12 is connected to the hydrogen circuit 2, it exchanges heat with at least one of the series of heat exchangers 3, 4, 5, 6 to cool the downstream end.

[0063] As shown, the series of heat exchangers 3, 4, 5, 6 of the cold box preferably includes multiple heat exchangers located in series between the upstream end 21 and the downstream end 22 of the hydrogen circuit 2. The connection between the downstream end of the recovery pipe 12 and the hydrogen circuit 2 is, for example, located downstream of the first passage of the hydrogen circuit 2 in the final heat exchanger 6 in series.

[0064] As shown, the first passage of the hydrogen circuit 2 in the final heat exchanger 6 preferably includes a section 29 for hydrogen catalysis, which is configured to perform the conversion of at least a portion of the orthohydrogen into secondary hydrogen. Downstream of this first passage in the catalytic section 29 of the heat exchanger 6, the hydrogen circuit 2 preferably includes an expansion unit 30, such as an expansion valve.

[0065] Similarly, the downstream end of the recovery pipe 12 preferably includes a unit 20 for expanding the vaporized gas flow, located between the portion that exchanges heat with one or more of the series of heat exchangers 5, 6 and the connection to the hydrogen circuit 2.

[0066] As shown, downstream of this connection, the hydrogen loop 2, which receives the cooled and expanded vaporized gas, can have a second passage in the final heat exchanger 6 for supplemental cooling. This second heat exchanger is preferably located in another section of the heat exchanger 6 that does not include the catalytic section.

[0067] As shown, downstream of this second passage in the final heat exchanger 6, the hydrogen loop 2 may include a unit 23 for expanding the hydrogen flow. This expansion unit 23 is, for example, the final expansion unit in a cold box, and includes, for example, an expansion valve and / or a cryogenic expansion turbine. The fluid thus expanded is liquefied and can then be supplied to a cryogenic storage tank via appropriate piping.

[0068] This configuration prevents the expansion of gaseous hydrogen, which would normally cause it to heat up. According to this configuration, the recovered gaseous hydrogen expands in the liquefier in two stages. The first expansion occurs at the outlet of the final catalytic heat exchanger 6, followed by expansion in the second passage within the exchanger 6 without catalytic conversion, and finally, expansion up to the final pressure level specified for the storage tank 8.

[0069] [ Figure 1 ]and[ Figure 3 ]to[ Figure 8 This demonstrates the different configurations or operations that can be implemented by facility 1.

[0070] As shown, the recovery conduit 12 preferably includes a first upstream end connected to the upper end of the storage tank 8 and a second upstream end designed to connect to the upper end of the vehicle-mounted storage tank 19. For example, the first and second upstream ends of the recovery conduit 12 are connected to the downstream end of the recovery conduit via two different conduit branches 121 and 122, respectively. These two branches 121 and 122 may be equipped with corresponding valves 221 and 222.

[0071] Additionally, the downstream end 22 of the hydrogen circuit may include two ends connected to the lower and upper parts of the reservoir via corresponding valves 201 and 202, respectively, so as to fill the reservoir 8 with its liquid phase or its gaseous phase.

[0072] Additionally, as shown, the extraction conduit 11 may include an upstream end connected to the reservoir 8 (lower section), which preferably has a valve 111 and two downstream ends. The first downstream end, equipped with valve 112, may be designed to be detachably connected to the reservoir (lower section) to be filled with liquid. The second downstream end of the extraction conduit 11 may have a valve 113 and may be connected to the second upstream end (branch 122) of the conduit 12 for gas recovery.

[0073] This fluid connection between the extraction pipe 11 and the branch 122 allows liquid to be injected into the tank 19 from the top (e.g., rain-fill).

[0074] In the different configurations shown, closed valves are indicated in black, while open valves are indicated in white.

[0075] exist[ Figure 1 The configuration does not include a vehicle-mounted storage tank to be filled.

[0076] Hydrogen from source 23 is liquefied by liquefier 31 and distributed to storage tank 8 via piping in loop 2. Valve 222 for recovering gas from the on-board storage tank is closed. Hydrogen can be supplied to the storage tank from the lower part. The hydrogen supplied by liquefier 31 can be subcooled to maintain the pressure in storage tank 8 and withstand its heat input. The pressure in storage tank 8 can be regulated by valves 201 and 202, which ensures filling from the bottom and / or from the top. As shown, valve 221 at the first downstream end of the piping for recovering vaporized gas from storage tank 8 can be opened to keep piping 121, 12 cold.

[0077] exist[ Figure 3 In this configuration, the on-board storage tank 19 to be filled is connected to the first downstream end of the extraction pipe 11. The storage tank 19 is also connected to the second upstream end (branch 122) of the recovery pipe 12.

[0078] After connecting the storage tank 19 to the extraction pipe 11 and to the pipe 12 for recovering gas, the pressure in the storage tank 19 (e.g., between 3 bar and 10 bar) can be reduced to a level lower than the pressure P8 in the reservoir 8 (e.g., reduced to a few millibars below P8). This is done to allow the storage tank 19 to be filled with liquid from the reservoir using the pressure differential (without a pump).

[0079] The hydrogen present in storage tank 19 is typically mainly gaseous (1% to 10% liquid) and at a temperature between 100K and 25K. A first portion of the recovered hot hydrogen can be sent to recovery system 32 via a parallel line equipped with valve 322.

[0080] When the temperature in storage tank 19 drops to a certain level (e.g., between 50K and 30K), the gas can be sent to the liquefier (valve 222 opens).

[0081] This gaseous hydrogen will be liquefied in liquefier 31 as described above and will be able to flow back to storage tank 8, provided that the pressure in storage tank 19 is higher than the pressure in storage tank 8 (plus the load loss of the loop).

[0082] To depressurize tank 19, it may be necessary to reduce its pressure to below that of storage tank 8. Several possibilities exist. In a first option, depressurization of tank 19 can be directed toward recovery system 32, see […]. Figure 4 ].

[0083] Alternatively, pressure equalization can be performed between tank 19 and reservoir 8 (see […]). Figure 5 [Valve 222 and 221 open], then the reservoir is pressurized via the liquefaction unit (valve 201 opens, see […]). Figure 5In other words, the gas is transported from the storage tank 19 to the storage unit via a branch 122 and then 121 of the recovery pipe 12.

[0084] At the end of the first sequence, the pressure P19 of tank 19 is lower than the pressure P8 of storage tank 8.

[0085] Then, as [ Figure 6 As shown, storage tank 19 can be filled with liquid. Liquid hydrogen can be delivered from storage tank 8 to the upper part of storage tank 19 via extraction pipe 11 and valve 113 of a branch connected to a pipe for gas recovery.

[0086] The liquid from storage tank 8 can be cooled sufficiently to maintain pressure P19 in the storage tank via vapor in condensate tank 19. The pressure in storage tank 8 can be maintained by injecting liquid hydrogen from the liquefier into the gas phase of the storage tank (filled from the top via branch 121 of pipe 12 for gas recovery when valve 221 is open). This hydrogen can come from hydrogen loop 2, which expands and heats in the heat exchanger. Therefore, during this phase, the corresponding cooling can be recovered internally within the liquefier 31, rather than by injecting heat into storage tank 8 via the pressurization unit (“PBU”).

[0087] At the end of the sequence, the pressure P19 of storage tank 19 can still be close to the pressure P8 of storage tank 8. Storage tank 19 is filled to more than half of its capacity (e.g., between 85% and 95% of its capacity), but in order to be able to transport on the road and not lose hydrogen during operation, its pressure should preferably be reduced.

[0088] The pressure of storage tank 19 during transportation may depend on local regulations.

[0089] This depressurization can be achieved, for example, by degassing the recovery system 32 (valve 322 opens). The pressure in storage tank 19 can, for example, reach 1.5 bar. Simultaneously, the facility can continue to control the pressure in storage tank 8, for example, by injecting supercooled liquid hydrogen into the top and / or bottom of storage tank 8 via control valves 202 and 201. [See reference] Figure 7 ].

[0090] [ Figure 8 A variant embodiment is shown, which is related to [...]. Figure 1 The difference lies only in that the branch 122 of the recovery pipe 12, designed to recover vaporized gas from the storage tank 19, includes a compression unit 24, such as a cryogenic compressor (a cold compressor configured to compress vapor at temperatures between 25K and 100K). As shown, a bypass pipe 124 for the compressor 24 and a series of valves 224, 324 can be provided to ensure that all or part of the flow passes through or does not pass through the compressor 24.

[0091] The compression unit 24 allows for better recovery of vapor from the storage tank 19 on the pipeline 12, so that the vapor can be returned to the liquefier 31.

[0092] The compression unit 24 increases the pressure of the recovered hydrogen vapor during the transport phase, when the pressure available in the storage tank 19 is insufficient to ensure the recovery of hydrogen vapor into the storage tank 8 and / or liquefaction tank 31 via pressure differential. Compared to conventional compressors at ambient temperature, the cryogenic compressor 24 has the advantage of a smaller size due to the higher density of cold hydrogen. Maintaining the cold temperature of the hydrogen during compression allows the compressed cold hydrogen to be easily recovered into the storage tank 8 or to the liquefaction tank 31 for reliquefaction.

[0093] [ Figure 8 The configuration of ] corresponds to [ Figure 1 The configuration is as follows: Hydrogen in loop 2 is liquefied by liquefier 31 and distributed into reservoir 8. This hydrogen may be subcooled to control and maintain the pressure in reservoir 8 and to withstand its heat input. This pressure in reservoir 8 can be regulated via valves 202, 201 (top / bottom filling). As shown, valve 221 on the branch for recovering vaporized gas from reservoir 8 can be opened to keep the line cold. Valves 222, 322 on the branch for recovering vaporized gas from tank 19 are closed, and compressor 24 is preferably stationary.

[0094] [ Figure 9 The diagram illustrates a configuration for depressurizing the tank 19 to be filled, which corresponds to […]. Figure 3 The configuration of the extraction pipe 11 is as follows. It should be noted that in the illustrated embodiment, the extraction pipe 11 is not connected to the upper part of the storage tank (via branch 122), but it is understood that the extraction pipe may be connected to the upper part of the storage tank.

[0095] After connecting the storage tank to extraction line 11 and gas recovery lines 12, 122, the pressure in storage tank 19 (e.g., from 3 bar to 10 bar) can be reduced to below the pressure in storage tank 8. The hydrogen present in storage tank 19 is primarily gaseous (1% to 10% liquid) and at a temperature between, for example, 100 K and 25 K. A first portion of the recovered hot hydrogen can be sent to recovery system 32 (valve 322 open). Once the temperature of the gas in storage tank 19 drops (e.g., between 50 K and 30 K), the recovered gas can be sent to liquefaction tank 31 (valve 222, 224 of line 12 open). This hydrogen will be liquefied as described above (throughflow and expansion in exchanger 6) and then supplied to storage tank 8, provided that the pressure in storage tank 19 remains higher than the pressure in storage tank 8 (plus the load losses of the involved loops). Compressor 24 is preferably not used in this first depressurization stage but can be cooled by vapor returning to liquefaction tank 31.

[0096] like[ Figure 10 As shown in the diagram, to achieve pressure reduction in tank 19, the pressure can be lowered to below that of reservoir 8. Compressor 24 can be used to draw vapor from tank 19 and deliver it to reservoir 8. During this stage, the backflow to liquefier 31 can be shut off. The pressure in reservoir 8 can still be regulated by valves 202 and 201. Thus, gas is delivered from tank 19 to reservoir 8.

[0097] Upon completion of this step, the pressure in storage tank 19 is lower than the pressure in storage vessel 8. This indicates that the main portion of storage tank 19 is filled with liquid. Liquid hydrogen is supplied from storage vessel 8 to storage tank 19 via extraction pipe 11 (valve 111 is open). The pressure in storage vessel 8 can be maintained by injecting hydrogen from liquefier 31 (valve 201 and / or 202). The pressure in storage tank 19 can be maintained below the pressure in storage vessel 8 due to compressor 24. [See reference] Figure 10 ].

[0098] At the end of this step, the pressure in tank 19 can still be close to that in storage tank 8. The fill level of tank 19 is relatively high (e.g., between 85% and 95%), but its pressure may need to be reduced to allow for transport and to prevent hydrogen loss during transit. This pressure during transport may depend on local regulations. Compressor 24 makes it possible to reduce this pressure in tank 19 to the required start-up pressure (either without using valve 332 leading to the recovery system, or by avoiding hydrogen loss during transit). The gas in tank 19 is pumped toward storage tank 8 (see […]). Figure 12 ]).

[0099] The refrigeration compressor 24 can also be used to reduce the pressure in the storage tank 8 without providing a supply of subcooled hydrogen. This increases the liquefier's production capacity.

[0100] [ Figure 13 A variant embodiment of the loop in which the recovered vaporized gas is recirculated within the cold box 18 of the liquefier 31 is shown. For simplicity, in [ Figure 13 The image only shows a portion of the cold box 18 and its circuitry. Figure 13 The embodiments of ] and [ Figure 2 The difference in the embodiment is that the downstream end of the recovery pipeline 12 includes a catalytic section 25 (e.g., a catalytic converter) upstream of its connection with the hydrogen loop 2, which is configured to perform the conversion of at least a portion of the secondary hydrogen into the positive hydrogen.

[0101] Additionally, the recovery conduit 12 includes a bypass section 26 and a series of valves 27, 28, which are configured to ensure that vaporized gas passes through or does not pass through the catalytic section 25.

[0102] The required specifications for hydrogen liquefaction unit 31 are to provide a minimum conversion rate of approximately 95% secondary hydrogen at the liquefaction unit outlet. Depending on the hydrogen pressure, the catalyst present in one or more final exchangers 5, 6 typically allows for a conversion rate between 98% and 100%.

[0103] Gaseous hydrogen refluxed from the storage tank 19 to be filled is obtained through liquid vaporization and is typically composed of secondary hydrogen in proportions between 98% and 100%.

[0104] In some cases, facility 1 is not suitable for recovering superheated hydrogen vapor, as this could interfere with the operation of liquefier 31.

[0105] These recovered vapors can be cooled by using the conversion of orthohydrogen to parahydrogen, which is the opposite of the conversion of the stream in hydrogen loop 2 in the liquefaction unit.

[0106] Therefore, for example, the temperature of these recovered vaporized gases can be between 50K and 25K. The higher the temperature, the further the hydrogen is from its equilibrium state at that temperature (20K for hydrogen that is 98% positive hydrogen), and the conversion of secondary hydrogen to positive hydrogen will require more cooling of the hydrogen.

[0107] Therefore, the vapor is converted from secondary hydrogen to positive hydrogen, then liquefied in the heat exchanger 6 / expansion unit 20, and then mixed with hydrogen from the circuit 2 before supplying the storage tank 8 (as previously described).

[0108] In principle, this type of catalytic converter 25 is only required when gaseous hydrogen reaches sufficient heat (e.g., when the pressure in the tank 19 to be filled begins to decrease) and is under sufficient pressure (typically between 3 and 10 bar). Bypass systems 26, 27, and in particular valves, can be configured to ensure access to the conversion catalytic converter based on the gas reflux temperature, which can be measured by a temperature sensor 33 in the recovery line 12.

[0109] Therefore, when the measured temperature becomes sufficiently cold, or the pressure in the recovery pipeline decreases (the depressurization of tank 19 ends), the loop valve 28 closes, and the direct supply valve 27 of the exchanger 6 opens to reduce the load loss of the system.

[0110] This pressurization control of tank 19 limits the flow rate related to the liquefier capacity (which can provide control over the outlet temperature of the reliquefied gas exchanger).

[0111] It should be understood that this embodiment can be applied to the embodiments and steps described above.

[0112] Furthermore, the above examples are not limiting. Thus, for example, the facility may include multiple storage tanks 8 and / or multiple pipes 11 for filling and multiple pipes 12 for recovering vaporized gas.

[0113] The refrigeration compressor 24 can be positioned in parallel with the recovery pipeline to deliver gas to the liquefier, especially when multiple storage tanks are being processed simultaneously.

Claims

1. A facility for hydrogen liquefaction, the facility comprising a hydrogen loop having an upstream end designed to be connected to a gaseous hydrogen source and a downstream end connected to at least one cryogenic storage tank for liquefied hydrogen in the facility, the cryogenic storage tank being provided with an extraction pipe configured to allow the supply of liquefied hydrogen to at least one storage tank, particularly a vehicle-mounted storage tank, to be filled, the facility comprising a cold box housing a series of heat exchangers that exchange heat with the hydrogen loop, the facility comprising a cooling device that exchanges heat with at least a portion of the series of heat exchangers, the cooling device being configured to cool the hydrogen loop. The cooling device includes a cryogenic refrigerator having a refrigeration cycle for a circulating gas in its operating loop, the circulating gas including at least one of hydrogen and helium. The operating loop of the refrigerator includes a unit for compressing the circulating gas, at least a portion of the series of heat exchangers, a unit for expanding the circulating gas, and the series of heat exchangers. The facility includes a conduit for recovering vaporized gas, the conduit having at least one upstream end connected to the storage tank and / or designed to connect to a tank to be filled, and a downstream end connected to the hydrogen circuit. Inside the cold box, the downstream end of the pipe for recovering vaporized gas includes a section that exchanges heat with at least one of the series of heat exchangers before its connection to the hydrogen circuit. This series of heat exchangers includes multiple heat exchangers arranged in series between the upstream and downstream ends of the hydrogen circuit. The hydrogen circuit has a first passage in the last of the series of heat exchangers, and an expansion unit is included downstream of this first passage. The connection between the downstream end of the pipe for recovering vaporized gas and the hydrogen circuit is located in the last of the series of heat exchangers in the hydrogen circuit. Downstream of the first passage and downstream of the expansion unit, downstream of the connection, the hydrogen circuit receiving cooled and expanded vaporized gas has a second passage in the last of the series heat exchangers for supplemental cooling, and downstream of the second passage in the last of the series heat exchangers, the hydrogen circuit includes a unit for expanding the hydrogen flow, and the downstream end of the pipe for recovering vaporized gas includes a unit for expanding the vaporized gas flow located between the portion that exchanges heat with at least one of the heat exchangers in the series and the connection with the hydrogen circuit.

2. The facility as claimed in claim 1, characterized in that, The storage tank is a vehicle-mounted storage tank, and / or the expansion unit is an expansion valve.

3. The facility as claimed in claim 1, characterized in that, The first passage of the hydrogen circuit in the last of the series heat exchangers includes a section for catalytic hydrogen conversion, which is configured to perform the conversion of at least a portion of the orthohydrogen into secondary hydrogen.

4. The facility as claimed in claim 2, characterized in that, The first passage of the hydrogen circuit in the last of the series heat exchangers includes a section for catalytic hydrogen conversion, which is configured to perform the conversion of at least a portion of the orthohydrogen into secondary hydrogen.

5. The facility according to claim 1, characterized in that, The second pathway leading to the last of the series heat exchangers does not include the section used for catalyzing orthohydrogen to secondary hydrogen.

6. The facility according to claim 2, characterized in that, The second pathway leading to the last of the series heat exchangers does not include the section used for catalyzing orthohydrogen to secondary hydrogen.

7. The facility according to claim 3, characterized in that, The second pathway leading to the last of the series heat exchangers does not include the section used for catalyzing orthohydrogen to secondary hydrogen.

8. The facility according to claim 4, characterized in that, The second pathway leading to the last of the series heat exchangers does not include the section used for catalyzing orthohydrogen to secondary hydrogen.

9. The facility as claimed in claim 1, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

10. The facility as claimed in claim 2, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

11. The facility as claimed in claim 3, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

12. The facility as claimed in claim 4, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

13. The facility as claimed in claim 5, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

14. The facility as claimed in claim 6, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

15. The facility as claimed in claim 7, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

16. The facility as claimed in claim 8, characterized in that, The unit for expanding the hydrogen flow in the hydrogen circuit located downstream of the second passage in the last of the series heat exchangers includes at least one of the following: an expansion valve and a turbine.

17. The facility as claimed in any one of claims 1 to 16, characterized in that, Upstream of the connection to the hydrogen loop, the downstream end of the pipeline for recovering vaporized gas includes a catalytic section configured to convert at least a portion of the secondary hydrogen into positive hydrogen.

18. The facility as claimed in claim 17, characterized in that, The downstream end of the pipeline used to recover vaporized gas includes a bypass section and a series of valves configured to ensure that the vaporized gas flows through or does not flow through the catalytic section.

19. The facility as claimed in any one of claims 1 to 16, characterized in that, The pipeline used to recover vaporized gas includes a compression unit.

20. The facility as claimed in claim 17, characterized in that, The pipeline used to recover vaporized gas includes a compression unit.

21. The facility as claimed in claim 18, characterized in that, The pipeline used to recover vaporized gas includes a compression unit.

22. The facility as claimed in claim 19, characterized in that, The compression unit is a low-temperature compressor.

23. The facility as claimed in any one of claims 1 to 16, characterized in that, The pipeline for recovering vaporized gas includes a first upstream end connected to the storage device and a second upstream end designed to connect to an onboard storage tank.

24. The facility as claimed in claim 17, characterized in that, The pipeline for recovering vaporized gas includes a first upstream end connected to the storage device and a second upstream end designed to connect to an onboard storage tank.

25. The facility as claimed in claim 18, characterized in that, The pipeline for recovering vaporized gas includes a first upstream end connected to the storage device and a second upstream end designed to connect to an onboard storage tank.

26. The facility as claimed in claim 19, characterized in that, The pipeline for recovering vaporized gas includes a first upstream end connected to the storage device and a second upstream end designed to connect to an onboard storage tank.

27. The facility as claimed in claim 22, characterized in that, The pipeline for recovering vaporized gas includes a first upstream end connected to the storage device and a second upstream end designed to connect to an onboard storage tank.

28. The facility as claimed in claim 19, characterized in that, The first and second upstream ends of the pipeline for recovering vaporized gas are connected to the downstream end of the pipeline for recovering vaporized gas via two different pipeline branches, and the compression unit is located in the pipeline branch at the second upstream end of the pipeline for recovering vaporized gas.

29. The facility as claimed in claim 22, characterized in that, The first and second upstream ends of the pipeline for recovering vaporized gas are connected to the downstream end of the pipeline for recovering vaporized gas via two different pipeline branches, and the compression unit is located in the pipeline branch at the second upstream end of the pipeline for recovering vaporized gas.

30. The facility as claimed in claim 23, characterized in that, The first and second upstream ends of the pipeline for recovering vaporized gas are connected to the downstream end of the pipeline for recovering vaporized gas via two different pipeline branches, and the compression unit is located in the pipeline branch at the second upstream end of the pipeline for recovering vaporized gas.

31. A method for hydrogen liquefaction using a facility according to any one of claims 1 to 30, the method comprising the steps of recovering vaporized gas via a pipeline for recovering vaporized gas, cooling the recovered vaporized gas in a cold box, expanding the vaporized gas in the cold box, and mixing the expanded vaporized gas with a stream of hydrogen to be cooled.

32. The method for hydrogen liquefaction as claimed in claim 31, the method comprising the step of expanding the mixture of the vaporized gas and the hydrogen stream to be cooled.

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