Hydrogen supply system, method for controlling the pressure in a hydrogen tank of a hydrogen supply system, and drive system

Abstract

The invention relates to a hydrogen supply system (10) comprising at least one hydrogen tank (16) for cryogenically storing hydrogen and for supplying hydrogen to a hydrogen-powered drive (12), a first heat transfer unit (18) for pre-heating the hydrogen for a cathode (20) of the drive, a first hydrogen supply path (24) between the at least one hydrogen tank and the first heat transfer unit, and a second hydrogen supply path (26) between the first heat transfer unit and an interface (28) for connecting to the drive. According to the invention, a heating circuit (30) is provided, wherein the heating circuit has a second heat transfer unit (32), the second heat transfer unit is arranged in the at least one hydrogen tank, the second hydrogen supply path and the second heat transfer unit are fluidically connected via a heat supply line (34) of the heating circuit, and the second heat transfer unit and the first hydrogen supply path are fluidically connected via a heat discharge line (36) of the heating circuit.

Description

[0001] Description

[0002] title in a

[0003] Hydrogen tank of a as well as

[0004] The invention relates to a hydrogen supply system, a method for pressure regulation in a hydrogen tank of a hydrogen supply system and a drive system.

[0005] State of the art

[0006] In order to minimize climate change, solutions to avoid greenhouse gas emissions are currently being sought in many areas of technology. One promising solution is to replace fossil fuels with hydrogen. On the one hand, hydrogen appears to be an almost ideal replacement in many respects, as its use not only eliminates greenhouse gas emissions, but also other pollutant emissions. On the other hand, the storage of hydrogen still presents a difficult problem. On the one hand, hydrogen requires very large storage volumes due to its low density. On the other hand, the flammability of mixtures with air must always be taken into account when using hydrogen. One possible solution to these problems is to store hydrogen as a cryogenic fluid. This requires either low pressures and extremely low temperatures (e.g., 4-6 bar, approx. 25 K) or high pressures at somewhat higher temperatures (e.g.,350 bar, approx. 70 K).

[0007] To prevent unwanted hydrogen leakage, the storage vessels used must be both leak-tight and very well thermally insulated. However, this creates the problem that the pressure in the vessel drops when hydrogen is extracted. To maximize the storage capacity of the vessels, it is therefore necessary to artificially increase the pressure.

[0008] Since the (continuous) operation of pumps under cryogenic conditions remains a challenge, it is already known to achieve operating pressure by heating the stored hydrogen. The necessary heating power can be provided, for example, by electric heaters.

[0009] Depending on the operation of the cryogenic storage system, a high heating output of, for example, 3 kW is required to maintain pressure. However, providing this heating output in the vehicle requires very high currents, which overload the on-board electrical system. The heat required for this is generated from electrical energy intended for higher-value tasks, such as propulsion or air conditioning. The heating output therefore contributes directly to the vehicle's fuel consumption and operating costs.

[0010] Advantages of the invention

[0011] The invention proposes a hydrogen supply system having the features of independent patent claim 1, a method having the features of independent patent claim 7, and a drive system having the features of independent patent claim 14. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the hydrogen supply system according to the invention naturally also apply in connection with the method according to the invention and / or in connection with the drive system according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other.

[0012] A first aspect of the invention is a hydrogen supply system for a fuel cell, in particular a fuel cell stack, of a motor vehicle, comprising at least one hydrogen tank for cryogenic storage of hydrogen and for supplying the fuel cell, a first heat transfer unit for preheating the hydrogen for a cathode of the fuel cell, a first hydrogen supply path between the at least one hydrogen tank and the first heat transfer unit, and a second hydrogen supply path between the first heat transfer unit and an interface for connection to the fuel cell.A heating circuit is provided, wherein the heating circuit has a second heat transfer unit, wherein the second heat transfer unit is arranged in the at least one hydrogen tank, wherein the second hydrogen supply path and the second heat transfer unit are fluidly connected via a heat supply line of the heating circuit, and wherein the second heat transfer unit and the first hydrogen supply path are fluidly connected via a heat discharge line of the heating circuit.

[0013] It is particularly advantageous if the hydrogen tank has an inner tank and an outer tank. The inner tank contains the hydrogen, while the outer tank surrounds the inner tank, like a thermos flask. There is a space between the outer and inner tanks that is evacuated to minimize direct heat conduction. In addition, a shield is often included to protect against radiant heat.

[0014] The second heat transfer unit can be located inside the inner tank or in the intermediate space. Locating the second heat transfer unit in the intermediate space has the advantage of preventing potential leaks, as the heat supply and heat dissipation of the heating circuit do not have to pass through the inner tank.

[0015] When hydrogen is withdrawn from the hydrogen tank, the pressure in the tank is reduced, thus eliminating the pressure gradient required to pump the hydrogen. Therefore, to regulate the pressure in the hydrogen tank during consumption, it is proposed to heat the hydrogen in the hydrogen tank using the heating circuit. This heating causes the hydrogen to begin to boil and evaporate. Due to this increase in volume, the pressure in the hydrogen tank is kept constant. The heating output of the second heat transfer unit can be designed to increase the volume proportionally to the hydrogen withdrawal. This leads to an optimized supply to the fuel cell.

[0016] At the same time, the first heat transfer unit can be connected to a cooling circuit of the hydrogen-powered drive system to heat the hydrogen using the waste heat from the coolant. The heat transfer in the first heat transfer unit indirectly utilizes the existing waste heat from the drive unit. This is particularly advantageous because the heating power for the heating circuit is not drawn from the hydrogen-powered drive system and thus no longer contributes to the vehicle's fuel consumption.

[0017] The heat transfer system returns the diverted hydrogen to the first hydrogen supply path, i.e., before the first heat transfer unit. The supplied hydrogen has a higher temperature than the hydrogen coming directly from the hydrogen tank, resulting in a slight warming of the hydrogen even before the first heat transfer unit.

[0018] The first heat transfer unit provides the heating power to bring the amount of hydrogen supplied to the consumer to a “comfortable temperature” and also to provide the heating power required to evaporate the hydrogen in the tank itself.

[0019] However, a small heat flow is actually “circulated” in this case.

[0020] Furthermore, the hydrogen supply system can have a tank pressure valve arrangement for regulating a pressure in the first hydrogen supply path, wherein the tank pressure valve arrangement is arranged between the at least one hydrogen tank and the first heat transfer unit. This regulates the pressure in the first hydrogen supply path and can have one or more pressure relief valves to increase safety. In addition, the hydrogen supply system can have a fuel cell valve arrangement for regulating a pressure in the second hydrogen supply path, wherein the fuel cell valve arrangement is arranged between the first heat transfer unit and the interface. This also increases the safety of the hydrogen supply system, since an overpressure can be regulated before the hydrogen-powered drive.

[0021] The pressure relief valves are particularly useful when the hydrogen supply system is at a standstill, since heat continues to be introduced into the tank from the outside due to the heat conduction, which cannot be completely prevented, heat can still be available and the pressure in the hydrogen tank or the first hydrogen supply path or the second hydrogen supply path can increase.

[0022] Within the scope of the invention, it may be advantageous for a pump to be provided in the heat supply line of the heating circuit.

[0023] The pump's output can be regulated depending on the heat extracted or supplied. The pump thus has a positive effect on the pressure gradient in the heating circuit and contributes to the optimized delivery of the heated hydrogen to the second heat transfer unit.

[0024] The pump also indirectly regulates the pressure and temperature of the hydrogen in the hydrogen tank.

[0025] The pump could, for example, be a diaphragm pump. These are suitable for continuous operation and seal the heat supply line from the environment.

[0026] Within the scope of the invention, it is conceivable that the first heat transfer unit is an evaporator for evaporating the hydrogen for the cathode of the hydrogen-powered drive.

[0027] The evaporation of hydrogen enables optimal preheating of the hydrogen for use in the fuel cell, so that the temperature and pressure conditions necessary for the proton pump reaction can be quickly generated.

[0028] Within the scope of the invention, it can be provided that at least one pressure sensor and / or at least one temperature sensor and / or at least one fill level sensor is provided in the at least one hydrogen tank.

[0029] The at least one pressure sensor and / or at least one temperature sensor and / or at least one fill level sensor serves to determine the actual values ​​of the hydrogen in the hydrogen tank. This is particularly advantageous for controlling and / or regulating the hydrogen supply system or the pressure in the hydrogen supply system.

[0030] It is also conceivable that a control unit is provided for regulating and / or controlling the heating circuit and / or the hydrogen supply system.

[0031] The control unit allows the hydrogen supply system to be automatically controlled and / or regulated. For example, sensor data can be recorded and evaluated to ensure optimal operation of the hydrogen supply system.

[0032] It is conceivable that the control unit has a comparison unit. This allows the recorded values ​​of at least one pressure sensor and / or one temperature sensor and / or one fill level sensor to be compared. For the comparison, it is conceivable that at least one target pressure and / or one target temperature and / or one target fill level are stored in the control unit.

[0033] It is also conceivable to provide at least one heat flow sensor, wherein the at least one heat flow sensor is arranged in the heat dissipation and / or the heat supply and / or the first hydrogen supply path and / or the second hydrogen supply path. This allows the introduced or discharged heat flow to be quickly and easily detected or determined. The pump output can be adjusted based on the data from the at least one heat flow sensor so that the pressure in the hydrogen tank changes, thus optimizing the delivery and / or heat transfer.

[0034] A second aspect of the invention is a method for regulating the pressure in a hydrogen tank of a hydrogen supply system according to the first aspect of the invention. The method comprises the following steps:

[0035] Conveying hydrogen from the at least one hydrogen tank to the first heat transfer unit via the first hydrogen supply path,

[0036] Heating the hydrogen for the hydrogen-powered propulsion and

[0037] Cooling the cooling liquid of the cooling circuit of the hydrogen-powered drive in the first heat transfer unit, conveying the heated hydrogen from the first heat transfer unit to the interface for supplying the fuel cell,

[0038] Diverting a portion of the heated hydrogen from the second hydrogen supply path into the heat supply line of the heating circuit, transferring heat from the heated hydrogen to the hydrogen in the at least one hydrogen tank in the second heat transfer unit,

[0039] Feeding the diverted portion of hydrogen from the heat dissipation into the first hydrogen supply path.

[0040] By pumping hydrogen from the hydrogen tank, hydrogen is extracted from the hydrogen tank, which reduces the pressure in the hydrogen tank and impairs its pumping properties. By diverting a portion of the heated hydrogen into the heat supply line of the heating circuit, the heat from the diverted hydrogen is then transferred to the hydrogen in the hydrogen tank in the second heat transfer unit. This transferred heat is capable of boiling the cryogenic hydrogen, causing it to evaporate and increasing the pressure in the hydrogen tank. This pressure increase leads to an optimized pressure gradient and thus improves the pumping properties of the hydrogen in the hydrogen supply system.

[0041] Within the scope of the invention, it is optionally possible for the first heat transfer unit to be an evaporator, wherein the hydrogen is evaporated during heating by means of the evaporator.

[0042] This makes hydrogen an optimal reactant for the reactions in the fuel cell.

[0043] Furthermore, within the scope of the invention, it can be provided that the actual pressure in the at least one hydrogen tank is measured by means of the pressure sensor and recorded by the control unit. Additionally or alternatively, the actual temperature in the at least one hydrogen tank is measured by means of the temperature sensor and recorded by the control unit. Additionally or alternatively, the actual fill level in the at least one hydrogen tank is measured by means of the fill level sensor and recorded by the control unit.

[0044] The pump's output can be controlled and / or regulated based on the actual pressure and / or temperature. In the case of a low actual pressure and / or temperature and / or low actual fill level, the output can be increased briefly or continuously, so that the pressure gradient in the heating circuit leads to improved delivery of the heated and diverted hydrogen in the heating circuit. This automatically increases the heat flow and enhances the heat transfer of the second heat transfer unit, which in turn increases the pressure in the hydrogen tank and improves the delivery capacity of the hydrogen supply system.

[0045] It is conceivable that the actual fill level is compared with the target fill level, taking into account the amount of hydrogen withdrawn, so that a system error or leakage can be identified.

[0046] With regard to the present invention, it is conceivable that the detected actual pressure is compared with a target pressure stored in the control unit by means of a comparison unit of the control unit, wherein if the actual pressure falls below the target pressure, the control unit regulates and / or controls the power of the pump in the heat supply line until the actual pressure corresponds to the target pressure.

[0047] This allows for precise pressure adjustment to achieve an optimized pressure gradient for hydrogen delivery in the hydrogen supply system. Once the target pressure is reached, the pump's power can be reduced again or the pump can be temporarily switched off, preventing flow through the heating circuit.

[0048] Furthermore, it is conceivable that the recorded actual temperature is compared with a target temperature stored in the control unit by means of a comparison unit of the control unit, whereby if the actual temperature falls below the target temperature, the control unit regulates and / or controls the power of the pump in the heat supply line until the actual temperature corresponds to the target temperature.

[0049] This allows for precise temperature adjustment to achieve an optimized pressure gradient for hydrogen delivery in the hydrogen supply system. Once the target temperature is reached, the pump's power can be reduced again or the pump can be temporarily switched off, preventing flow through the heating circuit.

[0050] Within the scope of the invention, it is conceivable that a heat flow in the heat dissipation and / or the heat supply and / or the first hydrogen supply path and / or the second hydrogen supply path is measured with the at least one heat flow sensor and detected by means of the control unit.

[0051] By measuring the heat flow, the heat introduced into the hydrogen supply system or the hydrogen tank can be easily determined. The control unit's comparison unit can compare the measured heat flow with the measured pressure and / or temperature and / or fill level. If multiple heat flow sensors are present, the comparison unit can determine the difference between the respective heat flow sensors and thus determine the heat input.

[0052] Within the scope of the invention, it can be provided that the performance of the pump is regulated and / or controlled by means of the control unit by means of the detected heat flow of the at least one heat flow sensor.

[0053] The control unit can control and / or regulate the performance of the pump based on the recorded data and thus regulate the heat transfer in the second heat transfer unit, which indirectly regulates the actual pressure and / or the actual temperature of the hydrogen in the hydrogen tank.

[0054] A third aspect of the invention is a drive system with a fuel cell, in particular a fuel cell stack, and with a hydrogen supply system according to a first aspect of the invention, wherein the hydrogen supply system is designed to carry out a method according to the second aspect of the invention when regulating the pressure in the hydrogen tank of the hydrogen supply system.

[0055] Advantages described in detail for the hydrogen supply system for a hydrogen-powered drive according to the first aspect of the invention apply equally to a method for pressure regulation in a hydrogen tank of a hydrogen supply system according to the second aspect of the invention and to a drive system with a hydrogen-powered drive and with a hydrogen supply system according to the third aspect of the invention.

[0056] Further advantages, features, and details of the invention will become apparent from the following description, which describes several embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0057] Short description of the drawing

[0058] The invention is shown in the following figures:

[0059] Fig. 1 is a schematic representation of a hydrogen supply system according to the invention,

[0060] Fig. 2 is a schematic representation of a method according to the invention,

[0061] Fig. 3 is a schematic representation of a drive system.

[0062] Description of the embodiments

[0063] Fig. 1 shows a hydrogen supply system 10 for a hydrogen-powered drive 11, in particular a fuel cell stack 14, for example of a motor vehicle. The hydrogen supply system 10 has at least one hydrogen tank 16 for the cryogenic storage of hydrogen and for supplying the hydrogen-powered drive 11, a first heat transfer unit 18 for preheating the hydrogen for a cathode 20 of the hydrogen-powered drive 11, a first hydrogen supply path 24 between the at least one hydrogen tank 16 and the first heat transfer unit 18, and a second hydrogen supply path 26 between the first heat transfer unit 18 and an interface 28 for connection to the hydrogen-powered drive 11. In addition, the hydrogen supply system 10 provides a heating circuit 30 for heating the hydrogen in the hydrogen tank 16.

[0064] The heating circuit 30 has a second heat transfer unit 32, wherein the second heat transfer unit 32 is arranged in the at least one hydrogen tank 16. The second hydrogen supply path 26 and the second heat transfer unit 32 are fluidly connected via a heat supply line 34 of the heating circuit 30, and the second heat transfer unit 32 and the first hydrogen supply path 24 are fluidly connected via a heat discharge line 36 of the heating circuit 30.

[0065] The hydrogen tank 16 has an inner tank 15 and an outer tank 17, with an intermediate space 19 enclosed between the inner tank 15 and the outer tank 17. In the illustrated embodiment, the second heat transfer unit 32 is arranged in the intermediate space 19.

[0066] Due to the now possible heating of the hydrogen, the pressure regulation of the entire hydrogen supply system 10 is made possible.

[0067] In the present case, the cooling circuit 22 of the hydrogen-powered drive 11 is connected to the first heat transfer unit 18. To heat the hydrogen from the hydrogen tank 16, the heat of the cooling fluid is used, thus indirectly utilizing the waste heat of a drive unit (not shown).

[0068] Furthermore, a tank pressure valve arrangement 38 is provided for regulating a pressure in the first hydrogen supply path 24, wherein the tank pressure valve arrangement 38 is arranged between the at least one hydrogen tank 16 and the first heat transfer unit 18. Additionally, a fuel cell valve arrangement 40 is also provided for regulating a pressure in the second hydrogen supply path 26, wherein the fuel cell valve arrangement 40 is arranged between the first heat transfer unit 18 and the interface 28. Both the tank pressure valve arrangement 38 and the fuel cell valve arrangement 40 serve to ensure the safety of the hydrogen supply system 10.

[0069] To increase the flow rate, the heat supply line 34 of the heating circuit

[0070] 30, a pump 42 is provided. Diaphragm pumps have proven particularly advantageous in this case. In the embodiment shown in Fig. 1, the first heat transfer unit 18 is designed as an evaporator 44 for evaporating the hydrogen for the cathode 20 of the hydrogen-powered drive 11. Through the evaporation of the hydrogen, it easily reaches the state required for the reaction in the hydrogen-powered drive 11.

[0071] To determine the actual state of the hydrogen in the at least one hydrogen tank 16, at least one pressure sensor 46 for detecting the actual pressure pjst, a temperature sensor 48 for detecting the actual temperature TJst, and a fill level sensor 50 for detecting the actual fill level FJst are provided in the at least one hydrogen tank 16. The actual state indicates the existing pressure gradient in the hydrogen supply system 10, wherein the pump 42, and in particular its power P, is controlled based on the data on the respective actual state of the sensors 46, 48, 50.

[0072] The hydrogen supply system 10 provides a control unit 52 for regulating and / or controlling 170 the heating circuit 30 and / or the hydrogen supply system 10. The control unit 52 has a comparison unit 56 for comparing 180 the recorded actual data, actual pressure p_actual, actual temperature T_actual, and actual fill level F_actual with stored target data, target pressure p_setpoint, target temperature T_setpoint, and target fill level F_setpoint.

[0073] To detect the heat flow Qp, the hydrogen supply system 10 provides at least one heat flow sensor 54. The hydrogen supply system 10 provides a heat flow sensor 54 in the heat dissipation line 36, the heat supply line 34, and the first hydrogen supply path 24. Additionally, a heat flow sensor 54 can also be arranged in the second hydrogen supply path 26. The control unit 52 also detects the data from the heat flow sensors 54, and the comparison unit 56 can determine the amount of heat transferred based on the difference between the detected heat flows Qp of the heat flow sensors 54. Fig. 2 shows a method 100 for pressure regulation in a hydrogen tank 16 of a hydrogen supply system 10 according to Fig. 1. The method 100 comprises the following steps:

[0074] Conveying 110 hydrogen from the at least one hydrogen tank 16 to the first heat transfer unit 18 via the first hydrogen supply path 24,

[0075] Heating 120 of the hydrogen for the hydrogen-powered drive 11 and cooling the cooling liquid of the cooling circuit 22 of the hydrogen-powered drive 11 in the first heat transfer unit 18,

[0076] Conveying 110 of the heated hydrogen from the first

[0077] Heat transfer unit 18 to the interface 28 for supplying the hydrogen-powered drive 11 via the second hydrogen supply path 26,

[0078] Branching 130 of a portion of the heated hydrogen from the second hydrogen supply path 26 into the heat supply line 34 of the heating circuit 30,

[0079] Heat transfer 140 from the heated hydrogen to the hydrogen in the at least one hydrogen tank 16 in the second heat transfer unit 32,

[0080] Feeding 150 the diverted portion of hydrogen from the heat dissipation 36 into the first hydrogen supply path 24.

[0081] In the method 100 according to Fig. 2, the hydrogen is evaporated in a first heat transfer unit 18 designed as an evaporator 44.

[0082] Since the hydrogen tank 16 of the hydrogen supply system 10 of Fig. 1 has a pressure sensor 46, a temperature sensor 48 and a fill level sensor 50, in the method 100 the actual pressure pjst in the at least one hydrogen tank 16 is measured by means of the pressure sensor 46, the actual temperature T_ist in the at least one hydrogen tank 16 is measured by means of the temperature sensor 48 and the actual fill level F_ist in the at least one hydrogen tank 16 is measured by means of the fill level sensor 50 and each is recorded by the control unit 52. The recorded actual pressure pjst is compared with a target pressure p_soll stored in the control unit 52 by means of the comparison unit 56 of the control unit 52. If the actual pressure pjst falls below the target pressure p_soll, the control unit 52 will regulate and / or control the power P of the pump 42 in the heat supply line 34 until the actual pressure pjst corresponds to the target pressure p_soll

[0083] In addition, the recorded actual temperature TJst is compared with a target temperature T_soll stored in the control unit 52 by means of a comparison unit 56 of the control unit 52. Here, too, if the actual temperature T_ist falls below the target temperature T_soll, the control unit 52 regulates and / or controls the power P of the pump 42 in the heat supply line 34 until the actual temperature T_ist corresponds to the target temperature T_soll.

[0084] The heat flow Qp in the heat dissipation line 36, the heat supply line 34, and the first hydrogen supply path 24 are each measured with a dedicated heat flow sensor 54 and recorded by the control unit 52. The comparison unit 56 determines the difference between the heat flow Qp in the heat supply line 34 and the heat dissipation line 36, thereby determining the heat output transferred to the hydrogen in the hydrogen tank 16. The determined heat flow Qp in the first hydrogen supply path 24 can also be compared with the heat flows Qp of the heat dissipation line 36 or the heat supply line 34.

[0085] The control unit 52 regulates and / or controls the power P of the pump 42 by means of the detected heat flow Qp or the detected heat flows Qp of the at least one heat flow sensor 54.

[0086] Fig. 3 shows a drive system 58 with a fuel cell stack 14 having a plurality of fuel cells 12 and with a hydrogen supply system 10 according to Fig. 1. The hydrogen supply system 10 is designed to carry out a method 100 according to Fig. 1 when the pressure in the hydrogen tank 16 of the hydrogen supply system 10 is regulated.

Claims

Claims 1. A hydrogen supply system (10) for a hydrogen-powered drive (11), in particular for a fuel cell (12) or a fuel cell stack (14) for an end user, in particular a motor vehicle, comprising at least one hydrogen tank (16) for cryogenically storing hydrogen and for supplying the hydrogen-powered drive (11), a first heat transfer unit (18) for preheating the hydrogen for a cathode (20) of the hydrogen-powered drive (11), a first hydrogen supply path (24) between the at least one hydrogen tank (16) and the first heat transfer unit (18), and a second hydrogen supply path (26) between the first heat transfer unit (18) and an interface (28) for connection to the hydrogen-powered drive (11), characterized in that a heating circuit (30) is provided, wherein the heating circuit (30) has a second heat transfer unit (32),wherein the second heat transfer unit (32) is arranged in the at least one hydrogen tank (16), wherein the second hydrogen supply path (26) and the second heat transfer unit (32) are fluidly connected via a heat supply line (34) of the heating circuit (30), and wherein the second heat transfer unit (32) and the first hydrogen supply path (24) are fluidly connected via a heat discharge line (36) of the heating circuit (30).

2. Hydrogen supply system (10) according to claim 1, characterized in that a pump (42) is provided in the heat supply line (34) of the heating circuit (30).

3. Hydrogen supply system (10) according to claim 1 or 2, characterized in that that the first heat transfer unit (18) is an evaporator (44) for Evaporation of hydrogen for the cathode (20) of the hydrogen-powered drive (11) is 4. Hydrogen supply system (10) according to one of the preceding Claims, characterized in that at least one pressure sensor (46) and / or at least one temperature sensor (48) and / or at least one fill level sensor (50) is provided in the at least one hydrogen tank (16).

5. Hydrogen supply system (10) according to one of the preceding Claims, characterized in that a control unit (52) is provided for regulating and / or controlling (170) the heating circuit (30) and / or the hydrogen supply system (10).

6. Hydrogen supply system (10) according to one of the preceding claims, characterized in that at least one heat flow sensor (54) is provided, wherein the at least one heat flow sensor (54) is arranged in the heat dissipation (36) and / or the heat supply line (34) and / or the first hydrogen supply path (24) and / or the second hydrogen supply path (26).

7. A method (100) for pressure regulation in a hydrogen tank (16) of a hydrogen supply system (10) according to one of the preceding claims, comprising the following steps: - conveying (110) hydrogen from the at least one hydrogen tank (16) to the first heat transfer unit (18) via the first hydrogen supply path (24), - heating (120) the hydrogen for the hydrogen-powered drive (11) in the first heat transfer unit (18), - conveying (110) the heated hydrogen from the first heat transfer unit (18) to the interface (28) for supplying the hydrogen-powered drive (11) via the second hydrogen supply path (26), - branching (130) a portion of the heated hydrogen from the second hydrogen supply path (26) into the heat supply line (34) of the heating circuit (30), - transferring heat (140) from the heated hydrogen to the hydrogen in the at least one hydrogen tank (16) in the second heat transfer unit (32), - feeding (150) the branched portion of hydrogen from the heat dissipation (36) into the first hydrogen supply path (24).

8. Method (100) according to 7, characterized in that the first heat transfer unit (18) is an evaporator (44), wherein the hydrogen is evaporated during heating (120) by means of the evaporator (44).

9. Method (100) according to claim 7 or 8, characterized in that the actual pressure (pjst) in the at least one hydrogen tank (16) is measured by means of the pressure sensor (46) and detected by means of the control unit (52) and / or that the actual temperature (TJst) in the at least one hydrogen tank (16) is measured by means of the temperature sensor (48) and detected by means of the control unit (52) and / or that the actual fill level (FJst) in the at least one hydrogen tank (16) is measured by means of the fill level sensor (50) and detected by means of the control unit (52).

10. Method (100) according to claim 9, characterized in that the detected actual pressure (p_actual) is compared with a target pressure (p_soll) stored in the control unit (52) by means of a comparison unit (56) of the Control unit (52) is compared, wherein if the actual pressure (p_actual) falls below the desired pressure (p_soll), the control unit (52) regulates and / or controls the power (P) of the pump (42) in the heat supply line (34) until the actual pressure (p_actual) corresponds to the desired pressure (p_soll).

11. Method (100) according to claim 9 or 10, characterized in that the detected actual temperature (T_actual) is compared with a target temperature (T_soll) stored in the control unit (52) by means of a comparison unit (56) of the control unit (52), wherein if the actual temperature (T_actual) falls below the target temperature (T_soll), the control unit (52) regulates and / or controls the power (P) of the pump (42) in the heat supply line (34) until the actual temperature (T_actual) corresponds to the target temperature (T_soll).

12. Method (100) according to claim 7 to 11, characterized in that a heat flow (Qp) in the heat dissipation (36) and / or the heat supply line (34) and / or the first hydrogen supply path (24) and / or the second hydrogen supply path (26) is measured with the at least one heat flow sensor (54) and detected by means of the control unit (52).

13. Method (100) according to claim 12, characterized in that the power (P) of the pump (42) is regulated and / or controlled by means of the control unit (52) by means of the detected heat flow (Qp) of the at least one heat flow sensor (54).

14. Drive system (58) with a hydrogen-powered drive (11), in particular with a fuel cell stack (14), and with a hydrogen supply system (10) according to one of claims 1 to 6, wherein the hydrogen supply system (10) is designed to, during pressure regulation in the hydrogen tank (16) of the Hydrogen supply system (10) to carry out a method (100) according to claims 7 to 13.

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