Hydrogen tank system and method for dispensing cryogenic hydrogen

Abstract

A method (200) for dispensing cryogenic hydrogen from a hydrogen storage system (10) comprising a liquid hydrogen tank (12), a cryopumping system (16), and a dispensing line (14) is provided. The method includes conveying (202) an initial stream of cryogenic hydrogen via a conveying line (18) using the cryopumping system from the liquid hydrogen tank (12) to the dispensing line (14).The method (200) is characterized in that the method further comprises a withdrawal (204) of a second cryogenic stream of cryogenic hydrogen via a cooling line (22) from the liquid hydrogen tank (12), as well as a cooling (206) of the cryopump system (16) and / or an output stream of the cryopump system (16) and / or the output line (14) by means of the second stream of cryogenic hydrogen, and an at least partial return (208) of the second stream of hydrogen to the liquid hydrogen tank after cooling (206) of the cryopump system (16) and / or the output stream of the cryopump system and / or the output line.

Description

[0001] Provided are a method for dispensing cryogenic hydrogen from a hydrogen tank system, a hydrogen tank system for dispensing cryogenic hydrogen, a cryopump system for conveying a flow of cryogenic hydrogen from a liquid hydrogen tank to a dispensing line, and a use of a heat exchanger for dissipating heat from a cryopump system. The embodiments thus lie particularly in the field of hydrogen tank systems.

[0002] When storing technical gases in the form of cryogenic liquids, it is known in the art to evaporate a portion of the liquefied gas into the ambient air via a heat exchanger and return it to the storage tank in gaseous form in order to maintain the pressure in the storage tank, as described, for example, in DE 539336 C. In this process, valuable and laboriously generated cold is lost.

[0003] If the pressure in the storage tank rises above a threshold due to heat input, it may be necessary to vent gas to the atmosphere or, in the case of flammable gases, to vent it or recycle it to prevent the tank from bursting.

[0004] It is also known in the prior art to pre-cool the refueling lines up to the filler neck by flushing them with the cryogenic media when dispensing cryogenic media for refueling a consumer. The thus heated medium is conventionally collected via a return line and can be re-compressed and cooled before being discharged, as described, for example, in DE 10 2013 003999. Cooling the lines with liquid nitrogen has also been considered.

[0005] DE102014015987 describes the use of hydrogen that has already evaporated in the storage tank to pre-cool the lines to the pump before it is vented or catalytically burned. However, this only makes sense in very specific situations, such as when the filling station is in operation (even after a period of inactivity). The pressure drop caused by the constant withdrawal of hydrogen cools the tank during normal operation, so that no significant increase in pressure in the storage tank is to be expected during this operating state. Hydrogen regularly evaporates in the storage tank only when the filling station is not in operation. In this case, however, there is usually no need for cooling because the pumps and / or compressors are not running, and since no hydrogen is flowing through the lines, the temperature of the lines is also irrelevant.

[0006] The object is to provide a hydrogen tank system, a cryopump system, a use of a heat exchanger and a method for dispensing cryogenic hydrogen from a hydrogen tank system, which enrich the state of the art and optionally avoid disadvantages of the state of the art.

[0007] The problem is solved by a hydrogen tank system, a cryopump system, the use of a heat exchanger, and a method for dispensing cryogenic hydrogen from a hydrogen tank system having the features of the respective independent claims. Optional embodiments are specified in the subclaims and in the description.

[0008] A method is provided for dispensing cryogenic hydrogen from a hydrogen tank system comprising a liquid hydrogen tank, a cryopump system, and a dispensing line. The method comprises conveying a first stream of cryogenic hydrogen via a conveying line by means of the cryopump system from the liquid hydrogen tank to the dispensing line. The method is characterized in that it further comprises withdrawing a second cryogenic stream of cryogenic hydrogen from the liquid hydrogen tank via a cooling line.The method further comprises cooling the cryopump system and / or further components of the hydrogen tank system and / or an output stream of the cryopump system and / or the output line by means of the second stream of cryogenic hydrogen, and at least partially recirculating the second stream of hydrogen into the liquid hydrogen tank after cooling the cryopump system and / or the output stream of the cryopump system and / or the output line.

[0009] Furthermore, a hydrogen tank system for dispensing cryogenic hydrogen is provided, which comprises a liquid hydrogen tank, a dispensing line for dispensing cryogenic hydrogen, and a cryopump system for conveying a first stream of cryogenic hydrogen via a conveying line from the liquid hydrogen tank to the dispensing line. The hydrogen tank system also comprises a heat exchanger for cooling the cryopump system and / or an output stream of the cryopump system and / or the dispensing line by means of a second stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank via a cooling line, and a return line for at least partially returning the second stream of hydrogen to the liquid hydrogen tank after cooling the cryopump system and / or the output stream of the cryopump system and / or the dispensing line.

[0010] Furthermore, a cryopump system is provided for conveying a first stream of cryogenic hydrogen from a liquid hydrogen tank to an output line. The cryopump system comprises a conveying inlet for supplying the first stream of cryogenic hydrogen from the liquid hydrogen tank, and a conveying outlet for conveying the first stream of cryogenic hydrogen into the output line. Furthermore, the cryopump system comprises a heat exchanger with a cooling inlet and a cooling outlet, wherein the heat exchanger is configured to dissipate heat from the cryopump system into the liquid hydrogen tank via the cooling outlet by means of a second stream of cryogenic hydrogen supplied from the liquid hydrogen tank via the cooling inlet.

[0011] Also provided is a use of a heat exchanger for removing heat from a cryopump system for conveying a first stream of cryogenic hydrogen from a liquid hydrogen tank by means of a second stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank and returned to the liquid hydrogen tank.

[0012] Cryogenic hydrogen is cryogenic hydrogen. The temperature of the cryogenic hydrogen can be 100 K or less. In particular, the output of cryogenic hydrogen can include the output of liquid hydrogen and / or gaseous hydrogen under high pressure and / or cryogenically compressed hydrogen (CcH 2 ), gaseous hydrogen under pressure between 1 bar and approximately 500 bar at cryogenic temperatures between 30 K and approximately 200 K.

[0013] A hydrogen tank system is a tank system for dispensing hydrogen to consumers, such as hydrogen-powered vehicles and / or for filling storage containers for hydrogen, in particular for cryogenically compressed hydrogen.

[0014] The liquid hydrogen tank is a tank for storing hydrogen, with the stored hydrogen being partially or completely in liquid form. The release of hydrogen, for example during a refueling process, can optionally include the dispensing of cryogenically compressed, liquid, and / or gaseous hydrogen.

[0015] A cryopump system is a pump system that is suitable or designed for the conveyance and compression of cryogenic hydrogen. The cryopump system can comprise a pump and optionally further components, such as one or more devices for cooling the pump and / or other elements with which the cryogenic hydrogen comes into thermal contact during conveyance. The cryopump system can be connected to the liquid hydrogen tank via the conveyance line and can draw in the cryogenic hydrogen for conveyance and compression via the conveyance line. The cryopump system can also be connected via the discharge line to an interface for the refueling of one or more consumers, for example to one or more fuel pumps, to which the drawn-in hydrogen is conveyed by the cryopump system.

[0016] The cooling line is not identical to the delivery line. The delivery line can be formed separately from the cooling line. Optionally, the delivery line and the cooling line can run adjacent to one another and / or parallel and / or together can be thermally insulated from the environment. Optionally, the cooling line can at least partially spiral around the delivery line and / or concentrically surround the delivery line. The cooling line can serve to provide hydrogen from the liquid hydrogen tank for the purpose of cooling the cryopump system and / or the output stream of the cryopump system and / or the output line by means of the second stream of cryogenic hydrogen, whereby the output and / or consumption of the hydrogen withdrawn via the cooling line does not necessarily have to be provided.Rather, the hydrogen extracted via the cooling line can be directly or indirectly returned to the liquid hydrogen tank to maintain the optimal delivery pressure. The fact that at least a portion of the second hydrogen stream is returned to the liquid hydrogen tank after cooling the cryopump system and / or the output stream of the cryopump system and / or the output line means that at least a portion of the hydrogen is returned, while optionally another portion of the hydrogen can be used for another purpose. The cooling line can be vacuum-insulated.

[0017] The heat exchanger is a device for transferring heat from the cryopumping system and / or the output stream of the cryopumping system and / or the output line to the second stream of cryogenic hydrogen, and optionally for removing the transferred heat. The heat exchanger can thus be in thermal contact with the cryopumping system and / or the output stream of the cryopumping system and / or the output line.

[0018] The disclosure offers the advantage that components of the hydrogen tank system with which the cryogenic hydrogen comes into contact during the refueling process can be efficiently cooled. Thus, according to the disclosure, efficient cooling of the cryopump system and / or lines up to the filler neck, as well as the hydrogen to be dispensed itself, can be achieved. This maximizes the density of the dispensed hydrogen to over 80 kg / m3, allowing storage of the dispensed hydrogen at high density and a high mass flow of the dispensed hydrogen. Thus, the disclosure offers the advantage that even motor vehicles that need to absorb and / or store hydrogen at a particularly high density can be refueled with hydrogen.This can offer the advantage that commercial vehicles, such as trucks, can also be efficiently supplied with hydrogen from a hydrogen refueling system according to the disclosure, since the refueling of large quantities of hydrogen can be carried out in a shorter time than is possible with the state of the art.

[0019] Furthermore, the disclosure offers the advantage that the hydrogen that heats up and optionally evaporates during the cooling of the cryopump system, the output line, and / or the output stream is not lost to the environment, but can be at least partially returned to the liquid hydrogen tank to maintain it at an equilibrium pressure that would otherwise have to be maintained by additional heat input. This minimizes hydrogen losses during operation of the hydrogen tank system, thus increasing the efficiency and cost-effectiveness of the hydrogen refueling station compared to conventional hydrogen refueling stations. The cold from the evaporation of liquid hydrogen for cooling is thus not completely lost to the ambient air, but is used for refueling in a thermodynamically optimized manner.

[0020] Furthermore, and optionally, a hydrogen tank system according to the disclosure can either completely dispense with an external pressure build-up heat exchanger or operate with a smaller pressure build-up heat exchanger.

[0021] Furthermore, the disclosure offers the advantage that technically simple cryopumps can be used, since the cryopumps do not necessarily have to be arranged and / or operated in direct contact with liquid hydrogen. This allows the costs for the provision, operation, and / or maintenance of the hydrogen refueling system to be kept low. Thus, using robust, simple cryopumps (e.g., cryogenic reciprocating piston pumps), very high hydrogen refueling densities can be achieved without having to use structurally very complex, maintenance-intensive, and expensive cryopumps.

[0022] The method may further comprise dispensing the output stream of cryogenic hydrogen from the dispensing line in the form of liquid hydrogen or cryogenically compressed hydrogen. Dispensing may optionally occur via a fuel pump. The dispensed hydrogen may optionally be stored in a hydrogen tank of a consumer, such as a motor vehicle, or in another storage tank.

[0023] The output stream can be dispensed with a density of the cryogenic hydrogen of at least 75 kg / m 3< , optionally even 80 kg / m 3<. This can be made possible in particular by cooling the cryopump system and / or the output stream and / or the output line and / or optionally other components of the hydrogen filling station with which the cryogenic hydrogen comes into thermal contact. Dispensing the output stream with such a high density can enable the refueling of storage tanks and / or consumers that require a particularly high density of hydrogen for storage, such as commercial vehicles with a long range. In addition, the refueling process can optionally be shortened compared to dispensing with lower densities.

[0024] The method may further comprise regulating and / or controlling the withdrawal of the second cryogenic stream of cryogenic hydrogen from the liquid hydrogen tank. The regulating and / or controlling may be performed using a pressure and / or a temperature and / or a mass flow of the output stream of cryogenic hydrogen. This may enable precise adjustment of the desired temperature and / or density of the hydrogen delivered during the refueling process. Thus, this may offer the advantage that the refueling process takes place under predetermined conditions and can be standardized accordingly. Optionally, this may be used to vary a temperature and / or density of the output stream of hydrogen between refueling processes and / or during a refueling process. This allows for great flexibility with regard to the consumers to be refueled.

[0025] Control valves can be controlled to ensure the most optimized refueling with high mass flows and high refueling densities, optionally at a constant pressure in the liquid hydrogen tank. In addition to the pressure in the liquid hydrogen tank, the temperature of the cryopump system's output stream can also be optionally controlled. This enables lower outlet temperatures at the cryopump and higher refueling densities than conventionally possible.

[0026] Cooling the cryopump system and / or the output stream of the cryopump system and / or the output line by means of the second stream of cryogenic hydrogen can comprise feeding the second stream of cryogenic hydrogen into a heat exchanger of the cryopump system, such that the second stream of cryogenic hydrogen absorbs heat from the cryopump system. This can enable efficient heat removal by means of the second stream of cryogenic hydrogen. Optionally, this can offer the advantage that, as the heat is absorbed by the second stream of cryogenic hydrogen, the latter can evaporate without being lost to the environment. Rather, the hydrogen can also be retained in a piping system of the heat exchanger and / or in the return line in this case.The second stream of hydrogen may be partially or completely in gaseous form after cooling of the cryopumping system and / or the output stream of the cryopumping system and / or the output line. In other words, the second stream of cryogenic hydrogen may evaporate upon cooling.

[0027] The withdrawal of the second cryogenic hydrogen stream and / or the cooling of the cryopump system and / or an output stream of the cryopump system and / or the output line by means of the second cryogenic hydrogen stream can take place during a refueling process, i.e., simultaneously or with a temporal overlap, and / or between consecutive refueling processes. This can offer the possibility of keeping the hydrogen tank system cooled even during standby operation when no refueling is in progress, in order to reduce or minimize the need for any lead time before the next refueling process.

[0028] The heat exchanger can be designed as an evaporator heat exchanger. This can offer the advantage that the heat exchanger can transfer a particularly high degree of heat to the second stream of cryogenic hydrogen.

[0029] The at least partial return of the second stream of hydrogen to the liquid hydrogen tank can comprise a direct introduction of at least a portion of the second stream of hydrogen into the liquid hydrogen tank. This means that the returned hydrogen can be reintroduced into the liquid hydrogen tank without further conditioning. This can offer the advantage that the warmed hydrogen supplied to the tank, which can be in liquid and / or gaseous form, can serve to increase and / or maintain the pressure in the liquid hydrogen tank. Alternatively or additionally, the at least partial return of the second stream of hydrogen to the liquid hydrogen tank can comprise an indirect introduction of at least a portion of the second stream of hydrogen into the liquid hydrogen tank via a pressure build-up heat exchanger.This can offer the advantage that the hydrogen can first be appropriately conditioned, allowing the heat supply to the liquid hydrogen tank to be controlled accordingly. In the pressure buildup heat exchanger, the hydrogen is optionally warmed using ambient air before being introduced into the liquid hydrogen tank.

[0030] Optionally, at least a portion of the second hydrogen stream can be delivered to a consumer after cooling. Optionally, for this purpose, the second hydrogen stream can be admixed with the output stream. Alternatively or additionally, at least a portion of the second hydrogen stream can be used for another purpose after cooling. Optionally, at least a portion of the second hydrogen stream can be used to cool other objects after cooling. Optionally, at least a portion of the second hydrogen stream can be used to deliver to a consumer in the form of gaseous hydrogen under high pressure, for example at a pressure of 350 bar or 700 bar.

[0031] Optionally, the second stream of cryogenic hydrogen can also be used to cool hydrogen gas to a temperature of up to -40°C in conventional hydrogen tank systems for compressed gaseous hydrogen CGH 2 (H35 / H70 filling stations).

[0032] The second cryogenic stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank via the cooling line may comprise liquid hydrogen. Alternatively or additionally, the second cryogenic stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank via the cooling line may comprise gaseous hydrogen that has vaporized in the liquid hydrogen tank. This offers great flexibility regarding the cooling potential of the withdrawn hydrogen.

[0033] Furthermore, the method can comprise temporarily storing at least a portion of the first stream of cryogenic hydrogen in a buffer storage device between the cryopump system and the output line. This can offer the advantage that any fluctuations in the output stream with regard to its temperature and / or density and / or mass flow can be reduced or avoided. The buffer storage device can be designed as a high-pressure buffer storage device, optionally as a high-strength cryogenic pressure vessel, or can comprise one or more such devices. The buffer storage device can be integrated into the cryopump system and / or the output line. Optionally, the second stream of cryogenic hydrogen can also be used to cool the buffer storage device. Optionally, one or more further heat exchangers can be integrated into the buffer storage device.

[0034] The cryopump system and the heat exchanger can be at least partially thermally insulated from the environment. Optionally, the cryopump system and the heat exchanger can be integrated together in a cold box. This can enable good heat transfer from the cryopump system to the heat exchanger while still largely insulating the cryopump system and the heat exchanger from the environment.

[0035] In the following optional and non-limiting example, it is calculated that when hydrogen is compressed from 3.5 bar to 400 bar in a cryopump, the temperature reduction due to the control-optimized integrated cooling of the outlet stream from the cryopump can be approximately 4 K. The density of hydrogen at the outlet of the cryopump can be increased by approximately 2% compared to a state-of-the-art configuration.

[0036] The hydrogen is compressed by the cryopump system from 3.5 bar to 400 bar. This results in a density increase of 2% for 400 bar cryocompressed hydrogen, i.e., a density of 82.5 kg / m 3 compared to 80.8 kg / m 3 . The temperature decreases by 3.5 K at 400 bar, from 47.2 K to 43.7 K. The heat transfer capacity of the heat exchanger is 5.1 kW, not including the recovery of cold from the recycled hydrogen.

[0037] The features and embodiments mentioned above and explained below are not only to be regarded as disclosed in the respective explicitly mentioned combinations, but are also encompassed by the disclosure content in other technically meaningful combinations and embodiments.

[0038] Further details and advantages will now be explained in more detail using the following examples and optional embodiments with reference to the figures.

[0039] They show: Fig. 1 shows a hydrogen tank system for dispensing cryogenic hydrogen according to an optional embodiment; Fig. 2 shows a method according to an optional embodiment for dispensing cryogenic hydrogen from a hydrogen tank system; Fig. 3 shows a dispensing line according to an optional embodiment, extending from the cryopump system to a fuel pump.

[0040] In the following figures, identical or similar elements in the various embodiments are designated by identical reference numerals for the sake of simplicity.

[0041] Figure 1shows a schematic representation of a hydrogen tank system 10 for dispensing cryogenic hydrogen according to an optional embodiment. The hydrogen tank system 10 comprises a liquid hydrogen tank 12, a dispensing line 14 for dispensing cryogenic hydrogen, and a cryopump system 16 for conveying a first stream of cryogenic hydrogen via a conveying line 18 from the liquid hydrogen tank 12 to the dispensing line 14.

[0042] The hydrogen tank system 10 further comprises a heat exchanger 20 for cooling the cryopump system 16 and / or an output stream of the cryopump system 16 and / or the output line 14 by means of a second stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank 12 via a cooling line 22.

[0043] In addition, the hydrogen tank system 10 has a return line 24 for at least partially returning the second stream of hydrogen to the liquid hydrogen tank 12 after cooling the cryopump system 16 and / or the output stream of the cryopump system 16 and / or the output line 14.

[0044] The cryopump system 16 and the heat exchanger 20 can be at least partially thermally insulated from the environment. The heat exchanger 20 can be designed as an evaporator heat exchanger.

[0045] Optionally, the heat exchanger 20 can form part of the cryopump system 16. The cryopump system 16 can be configured to convey a first stream of cryogenic hydrogen from the liquid hydrogen tank 12 to the output line 14. The cryopump system 16 can include a conveying inlet 26 for supplying the first stream of cryogenic hydrogen from the liquid hydrogen tank 12 and a conveying outlet 28 for conveying the first stream of cryogenic hydrogen into the output line 14. Furthermore, the cryopump system 16 can include the heat exchanger 20 with a cooling inlet 30 and a cooling outlet 32, wherein the heat exchanger 20 is configured to dissipate heat from the cryopump system 16 into the liquid hydrogen tank 12 via the cooling outlet 32 ​​by means of a second stream of cryogenic hydrogen supplied from the liquid hydrogen tank 12 via the cooling inlet 30.

[0046] The return of the second stream of hydrogen to the liquid hydrogen tank 12 after cooling the cryopump system 16 can optionally be done directly or via a pressure build-up heat exchanger 34.

[0047] Optionally, the hydrogen tank system can include a buffer storage 36. This can be arranged between the cryopump system 16 and the output line 14. The output current of the cryopump system 16 can initially be temporarily stored in the buffer storage 36, so that the hydrogen is then delivered to a consumer from the buffer storage 36.

[0048] Based on Figure 2 In the following, a method 200 according to an optional embodiment for dispensing cryogenic hydrogen from a hydrogen tank system 10 having a liquid hydrogen tank 12, a cryopump system 16 and a dispensing line 14 is described. The method may optionally apply to a hydrogen tank system according to Figure 1 serve.

[0049] The method 200 comprises, in a step 202, conveying a first stream of cryogenic hydrogen via a conveying line 18 by means of the cryopump system 16 from the liquid hydrogen tank 12 to the output line 14.

[0050] The method 200 further includes, in a step 204, withdrawing a second cryogenic stream of cryogenic hydrogen via a cooling line 22 from the liquid hydrogen tank 12.

[0051] In a step 206, the method 200 includes cooling the cryopump system 16 and / or an output stream of the cryopump system 16 and / or the output line 14 using the second stream of cryogenic hydrogen. Cooling 206 of the cryopump system 16 and / or the output stream of the cryopump system 16 and / or the output line 14 using the second stream of cryogenic hydrogen may include feeding the second stream of cryogenic hydrogen into a heat exchanger 20 of the cryopump system 16 such that the second stream of cryogenic hydrogen absorbs heat from the cryopump system 16.

[0052] In a step 208, the method 200 comprises at least partially returning the second stream of hydrogen to the liquid hydrogen tank 12 after cooling the cryopump system 16 and / or the output stream of the cryopump system 16 and / or the output line 14. The at least partial return 208 of the second stream of hydrogen to the liquid hydrogen tank 12 may comprise directly introducing at least a portion of the second stream of hydrogen into the liquid hydrogen tank 12 and / or indirectly introducing at least a portion of the second stream of hydrogen into the liquid hydrogen tank 12 via a pressurization heat exchanger 34.

[0053] Optionally, the method further comprises, in a step 210, discharging the output stream of cryogenic hydrogen from the output line 14 in the form of liquid hydrogen or cryocompressed hydrogen. Discharging the output stream may comprise discharging the cryogenic hydrogen with a density of at least 75 kg / m 3 .

[0054] Furthermore, in a step 212, the method may include regulating and / or controlling the withdrawal of the second cryogenic stream of cryogenic hydrogen from the liquid hydrogen tank 12, wherein the regulating and / or controlling may be performed using a pressure and / or a temperature and / or a mass flow of the output stream of cryogenic hydrogen. The hydrogen tank system may have suitable sensors and / or actuators for this purpose.

[0055] The second stream of cryogenic hydrogen drawn from the liquid hydrogen tank 12 via the cooling line 22 may comprise liquid hydrogen. The second stream of cryogenic hydrogen drawn from the liquid hydrogen tank 12 via the cooling line 22 may alternatively or additionally comprise gaseous hydrogen that has vaporized in the liquid hydrogen tank 12. For this purpose, multiple cooling lines 22 may optionally be provided.

[0056] The method 200 may further comprise, in a step 214, temporarily storing at least a portion of the first stream of cryogenic hydrogen in a buffer storage 36 between the cryopump system 16 and the output line 14.

[0057] The second stream of hydrogen may be partially or completely in gaseous form after cooling the cryopump system 16 and / or the output stream of the cryopump system 16 and / or the output line.

[0058] In a further optional embodiment, the second stream of cryogenic hydrogen is also used to keep the process lines, in particular the discharge line, and components downstream of the cryopump system 16 up to the fuel pump (fueling interface to the vehicle) cool during refueling and in standby mode (no refueling). This enables high refueling densities and / or minimized evaporation losses.

[0059] Figure 3 shows, by way of example, a discharge line 14 extending from the cryopump system 16 to a dispenser 38 and thermally insulated with a flow line 40 for the second stream of cryogenic hydrogen to cool the discharge line during a refueling process and / or in standby mode. The heated cryogenic hydrogen can be recirculated through one or more bypass lines within the main process line (e.g., refueling hose). List of reference symbols

[0060] 10Hydrogen tank system 12Liquefied hydrogen tank 14Discharge line 16Cryopump system 18Delivery line 20Heat exchanger 22Cooling line 24Return line 26Delivery inlet 28Delivery outlet 30Cooling inlet 32Cooling outlet 34Pressure build-up heat exchanger 36Buffer tank 38Fuel pump 40Flow line 200for the dispensing of cryogenic hydrogen from a hydrogen tank system 202 - 214Procedure steps

Claims

1. A method (200) for dispensing cryogenic hydrogen from a hydrogen tank system (10) having a liquid hydrogen tank (12), a cryopump system (16) and a dispensing line (14), the method (200) comprising: - conveying (202) a first stream of cryogenic hydrogen via a conveying line (18) by means of the cryopump system (16) from the liquid hydrogen tank (12) to the dispensing line (14); characterized in thatthe method (200) further comprises: - withdrawing (204) a second cryogenic stream of cryogenic hydrogen from the liquid hydrogen tank (12) via a cooling line (22); - cooling (206) the cryopump system (16) and / or an output stream of the cryopump system (16) and / or the output line (14) by means of the second stream of cryogenic hydrogen; and - at least partially returning (208) the second stream of hydrogen to the liquid hydrogen tank (12) after cooling (206) the cryopump system (16) and / or the output stream of the cryopump system (16) and / or the output line (14).

2. The method (200) of claim 1, further comprising - dispensing (210) the output stream of cryogenic hydrogen from the output line (14) in the form of liquid hydrogen or cryocompressed hydrogen.

3. The method (200) of claim 2, wherein dispensing (210) the output stream comprises dispensing the cryogenic hydrogen having a density of the cryogenic hydrogen of at least 75 kg / m 3 occurs.

4. The method (200) according to any one of claims 2 and 3, comprising regulating (212) and / or controlling the withdrawal of the second cryogenic stream of cryogenic hydrogen from the liquid hydrogen tank (12), wherein the regulating (212) and / or controlling is performed using a pressure and / or a temperature and / or a mass flow of the output stream of cryogenic hydrogen.

5. The method (200) according to any one of the preceding claims, wherein cooling (206) the cryopump system (16) and / or the output stream of the cryopump system (16) and / or the output line (14) by means of the second stream of cryogenic hydrogen comprises feeding the second stream of cryogenic hydrogen into a heat exchanger (20) of the cryopump system (16) such that the second stream of cryogenic hydrogen absorbs heat of the cryopump system (16).

6. The method (200) according to any one of the preceding claims, wherein the at least partial recycling (208) of the second stream of hydrogen into the liquid hydrogen tank (12) comprises directly introducing at least a portion of the second stream of hydrogen into the liquid hydrogen tank (12) and / or indirectly introducing at least a portion of the second stream of hydrogen into the liquid hydrogen tank (12) via a pressure build-up heat exchanger (34).

7. The method (200) according to any one of the preceding claims, wherein the second cryogenic stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank (12) via the cooling line (22) comprises liquid hydrogen.

8. The method (200) according to any one of the preceding claims, wherein the second cryogenic stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank (12) via the cooling line (22) comprises gaseous hydrogen which has evaporated in the liquid hydrogen tank (12).

9. The method (200) according to any one of the preceding claims, further comprising: - temporarily storing (214) at least a portion of the first stream of cryogenic hydrogen in a buffer storage (36) between the cryopump system (16) and the output line (14).

10. The method (200) according to any one of the preceding claims, wherein the second stream of hydrogen is partially or completely in gaseous form after cooling (206) the cryopump system (16) and / or the output stream of the cryopump system (16) and / or the output line (14).

11. A hydrogen tank system (10) for dispensing cryogenic hydrogen, the hydrogen tank system (10) comprising: - a liquid hydrogen tank (12); - a dispensing line (14) for dispensing cryogenic hydrogen; and - a cryopump system (16) for conveying a first stream of cryogenic hydrogen via a conveying line (18) from the liquid hydrogen tank (12) to the dispensing line (14); characterized in thatthe hydrogen tank system (10) further comprises: - a heat exchanger (20) for cooling the cryopump system (16) and / or an output stream of the cryopump system (16) and / or the output line (14) by means of a second stream of cryogenic hydrogen taken from the liquid hydrogen tank (12) via a cooling line (22); and - a return line (24) for at least partially returning the second stream of hydrogen to the liquid hydrogen tank (12) after cooling the cryopump system (16) and / or the output stream of the cryopump system (16) and / or the output line (14).

12. Hydrogen tank system (10) according to claim 11, wherein the cryopump system (16) and the heat exchanger (20) are together at least partially thermally insulated from the environment.

13. Hydrogen tank system (10) according to claim 11 or 12, wherein the heat exchanger (20) is designed as an evaporator heat exchanger.

14. A cryopump system (16) for conveying a first stream of cryogenic hydrogen from a liquid hydrogen tank (12) to an output line (14), the cryopump system (16) comprising: - a conveying inlet (26) for supplying the first stream of cryogenic hydrogen from the liquid hydrogen tank (12); - a conveying outlet (28) for conveying the first stream of cryogenic hydrogen into the output line (14); - a heat exchanger (20) with a cooling inlet (30) and a cooling outlet (32), wherein the heat exchanger (20) is designed to dissipate heat from the cryopump system (16) via the cooling outlet (32) into the liquid hydrogen tank (12) by means of a second stream of cryogenic hydrogen supplied from the liquid hydrogen tank (12) via the cooling inlet (30).

15. Use of a heat exchanger (20) for dissipating heat from a cryopump system (16) for conveying a first stream of cryogenic hydrogen from a liquid hydrogen tank (12) by means of a second stream of cryogenic hydrogen withdrawn from the liquid hydrogen tank (12) and returned to the liquid hydrogen tank (12).

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