METHOD AND CONVEYING DEVICE

Description

[0001] The invention relates to a method for supplying a consumer with a cryogen from a storage container and a conveying device for supplying a consumer with a cryogen from a storage container.

[0002] According to the applicant's internal findings, storage containers for liquid hydrogen can have a pressure buildup evaporator, which makes it possible to build up pressure within the storage container so that gaseous hydrogen can be made available to a consumer, for example in the form of a fuel cell, at a stable supply pressure of, for example, 1 to 2.5 bara. During operation of such a storage container, for example in the maritime sector, movement of the storage container, for example due to sea waves, can make it very difficult to maintain the operating conditions in the storage container sufficiently stable to ensure that the required supply pressure for the fuel cell can be constantly provided.

[0003] The applicant is also aware of internal prior art in which the hydrogen is stored in the storage container at virtually zero pressure. In this case, the hydrogen is pumped with the aid of a cryopump and supplied to the fuel cell at the aforementioned supply pressure. However, such a cryopump has moving parts, which can result in a certain amount of maintenance and thus downtime. US 2014 / 076290 A1 discloses a device for supplying a consumer with gaseous hydrogen from a liquid hydrogen storage tank. A mechanical cryopump is not required.

[0004] WO 2014 / 076290 A1 forms the preamble of claim 1.

[0005] Furthermore, according to internal findings, it is also possible to vaporize the hydrogen upstream of the fuel cell and then compress it to achieve the required supply pressure. However, this is energetically unfavorable.

[0006] Against this background, the object of the present invention is to provide an improved method for supplying a consumer with a cryogen from a storage container.

[0007] Accordingly, a method for supplying a consumer with a cryogen from a storage container is proposed.The method comprises the following steps: a) introducing a portion of the cryogen from the storage vessel into a volume that can be separated from the consumer and from the storage vessel, b) separating the volume from the consumer and from the storage vessel by first closing a supply valve arranged between the volume and the consumer and then closing an inlet valve arranged between the storage vessel and the volume, c) evaporating the cryogen in the volume so that the volume is subjected to a pressure that is higher than a pressure prevailing in the storage vessel, and d) discharging the evaporated cryogen from the volume to the consumer when the consumer demands a load by opening the supply valve, wherein the inlet valve is opened when the supply valve is open as soon as the pressure in the volume falls below the pressure prevailing in the storage vessel.

[0008] Because the volume can be used as a pressure reservoir to supply the consumer with the vaporized cryogen, movement of the storage vessel, for example, during rough seas, has no negative impact on the consumer's supply of vaporized cryogen. This allows the storage vessel to be operated at the lowest possible pressure. This extends the cryogen's retention time. Furthermore, moving parts, such as those found in cryopumps, can be eliminated.

[0009] The cryogen is preferably hydrogen. The terms "cryogen" and "hydrogen" can therefore be interchanged arbitrarily. In principle, however, the cryogen can also be any other cryogen. Examples of cryogenic fluids or liquids, or cryogens for short, in addition to the aforementioned hydrogen, include liquid helium, liquid nitrogen, or liquid oxygen. A "cryogen" is therefore understood to mean, in particular, a liquid. The cryogen can also be vaporized and thus converted into the gaseous phase. After vaporization, the cryogen is a gas or can be referred to as gaseous or vaporized cryogen. The term "cryogen" can thus encompass both the gas phase and the liquid phase. The term "vaporized cryogen" here preferably refers only to the gas phase of the cryogen.

[0010] After or during filling of the cryogen into the storage vessel, a gas zone and an underlying liquid zone form in the storage vessel. A phase boundary is provided between the gas zone and the liquid zone. After filling into the storage vessel, the cryogen therefore preferably has two phases with different states of aggregation, namely liquid and gaseous. The liquid phase can transition into the gaseous phase and vice versa. The liquid phase can be referred to as the liquid phase. The gaseous phase can be referred to as the gas phase. A purely liquid filling of the storage vessel is also possible. The pressure prevailing in the storage vessel is preferably approximately 3.5 bara. The pressure prevailing in the storage vessel is, in particular, constant.

[0011] The consumer is preferably a fuel cell. A "fuel cell" in this context is understood to be a galvanic cell that converts the chemical reaction energy of a continuously supplied fuel, in this case hydrogen, and an oxidizing agent, in this case oxygen, into electrical energy. The cryogen is supplied to the consumer itself, particularly in gaseous form, at a defined supply pressure. This means that the cryogen is completely vaporized before or upstream of the consumer. For example, the cryogen is supplied to the consumer at a supply pressure of 1 to 2.5 bara and a temperature of +10 to +25°C. However, the supply pressure can also be up to 6 bara.

[0012] As previously mentioned, the cryogen can be biphasic. Preferably, in or during step a), the liquid phase or a portion of the liquid phase of the cryogen is introduced from the storage vessel into the volume separable from the consumer and the storage vessel. A "portion" is understood in particular to mean that a certain volume of the liquid phase of the cryogen is introduced from the storage vessel into the volume. A remainder of the liquid phase remains in the storage vessel. One or more valves can be provided for this purpose. Steps a) to d) are preferably carried out consecutively. To carry out the method, a conveying device, as explained below, is used, in particular.

[0013] The volume can be realized, for example, by a container, a pipe loop, or the like. The volume can also be referred to as a header or collector. The terms "volume," "header," and "collector" can be interchanged in this context. A "volume" is generally understood to mean an area that can be fluidically separated from the storage container and the consumer and pressurized. The volume thus serves as a pressure reservoir. The volume can therefore also be referred to as a pressure accumulator. This means that the terms "volume" and "pressure accumulator" can be interchanged in this context.

[0014] In or during step b), the volume is preferably separated from the consumer and the storage container by means of valves. "Separating" is understood here to mean that a fluid connection or a fluidic connection between the volume and the consumer, as well as between the volume and the storage container, is severed, so that the fluid can neither flow from the storage container into the separated volume nor can the fluid flow from the separated volume to the consumer.

[0015] In or during step c), in particular, the liquid phase of the cryogen remaining in the sealed volume is evaporated. For this purpose, heat is preferably introduced into the cryogen. Evaporation of the cryogen in the separated volume increases the pressure in the volume. For example, the pressure in the volume rises to a pressure of 3 to 10 bara. Preferably, a substantially constant pressure of, for example, 3.5 bara prevails in the storage container.

[0016] The discharge of the vaporized cryogen in or during step d) from the volume to the consumer is preferably carried out with the aid of a valve, in particular a supply valve, which can be controlled depending on the load requirement of the consumer in order to supply the consumer with the vaporized cryogen. The valve is also particularly suitable for supplying the cryogen to the consumer at the appropriate supply pressure. In or during step d), a fluid connection or fluidic connection is thus established between the volume and the consumer, so that the vaporized cryogen can flow from the volume to the consumer. In this case, a pressure reduction can be carried out with the aid of the valve.

[0017] According to one embodiment, during step d), the pressure prevailing in the volume is reduced to a supply pressure suitable for the consumer when the cryogen is discharged from the volume by means of the supply valve.

[0018] As previously mentioned, the suitable supply pressure can be, for example, 1 to 2.5 bara. A suitable supply temperature can be +10 to +25 °C. The supply valve can be controlled by a control and regulating device in such a way that it reduces the pressure prevailing in the separated volume to the suitable supply pressure.

[0019] According to a further embodiment, the supply pressure suitable for the consumer is lower than the pressure prevailing in the storage tank.

[0020] As previously mentioned, the pressure in the storage tank can be 3.5 bara. In contrast, the suitable supply pressure is 1 to 2.5 bara. The supply valve can be used to reduce the pressure in the storage tank to the appropriate supply pressure.

[0021] According to a further embodiment, during step d) the supply valve is opened depending on the load requirement of the consumer.

[0022] This means, in particular, that the supply valve is only opened when there is a load demand from the consumer. The supply valve can be opened continuously to adjust the volume flow of vaporized cryogen to the consumer's load demand.

[0023] According to a further embodiment, during step d), the supply valve is controlled by means of a control and regulating device based on sensor signals from a pressure sensor and / or a flow sensor arranged downstream of the supply valve.

[0024] "Downstream" in this context means along the cryogen flow direction from the storage vessel to the consumer. The control and regulation device is configured to receive and appropriately evaluate sensor signals from the pressure sensor and / or the flow sensor. Based on the sensor signals from the pressure sensor and / or the flow sensor, the control and regulation device can then control the supply valve.

[0025] During step b) the supply valve is closed.

[0026] The supply valve remains closed until the load demand from the consumer is met. Once the load demand from the consumer is met, the supply valve begins to open to supply the consumer with cryogen at the appropriate supply pressure.

[0027] During step b), the inlet valve located upstream of the supply valve is closed.

[0028] The supply valve and the inlet valve separate the volume from the consumer and the storage vessel. The volume is thus placed, arranged, or provided between the inlet valve and the supply valve. "Upstream" is understood here to refer to the direction of cryogen flow from the storage vessel to the consumer.

[0029] According to a further embodiment, the inlet valve is closed as long as the pressure in the volume is greater than the pressure prevailing in the storage container.

[0030] As long as the inlet valve is closed, no cryogen can flow from the storage vessel into the volume. The closed inlet valve prevents the cryogen from being forced back into the storage vessel from the volume as long as the pressure in the volume is greater than the pressure in the storage vessel.

[0031] The inlet valve is opened as soon as the pressure in the volume drops below the pressure in the storage tank.

[0032] Once the inlet valve is opened, cryogen can flow from the storage vessel into the volume. The supply valve can then reduce the pressure in the storage vessel to the appropriate supply pressure for the consumer. The cryogen from the storage vessel can be evaporated using an evaporator unit assigned to the volume.

[0033] According to a further embodiment, during step c) heat is introduced into the cryogen by means of an evaporator unit in order to evaporate it.

[0034] The evaporator unit can, for example, be or include an electric heating device. The evaporator unit can also be any heat exchanger or heat transfer device. The evaporator unit can be part of the volume.

[0035] Furthermore, a conveying device for supplying a consumer with a cryogen from a storage container is proposed. The conveying device comprises an inlet valve arranged between the storage container and a volume that can be separated from the consumer and the storage container, a supply valve arranged between the volume and the consumer, an evaporator unit, and a control and regulating device, wherein the control and regulating device is configured to control the inlet valve such that the inlet valve introduces a portion of the cryogen from the storage container into the volume, wherein the control and regulating device is configured to control the inlet valve and the supply valve such that the inlet valve and the supply valve separate the volume from the consumer and the storage container, wherein the control and regulating device is configured tofirst closing the supply valve and then the inlet valve, wherein the evaporator unit is configured to evaporate the cryogen accommodated in the separated volume in order to subject the separated volume to a pressure that is higher than a pressure prevailing in the storage container, wherein the control and regulating device is configured to control the supply valve such that the supply valve discharges the evaporated cryogen from the separated volume to the consumer upon a load demand from the consumer, and wherein the control and regulating device is configured to open the inlet valve when the supply valve is open as soon as the pressure in the volume drops below the pressure prevailing in the storage container.

[0036] The previously explained method can be carried out with the aid of the conveying device. The conveying device can comprise the storage container. The conveying device can also comprise the consumer. Alternatively, the storage container and / or the consumer can also not be part of the conveying device. The conveying device can also be part of a conveying arrangement, which can comprise the consumer and / or the storage container in addition to the conveying device.

[0037] The "volume" differs from the "separated volume" in that, in the separated volume, the inlet valve and the supply valve are closed, thus separating the volume from the consumer and the storage vessel. The fact that the inlet valve is "configured" to introduce a portion of the cryogen from the storage vessel into the volume means, in this case, in particular, that the inlet valve can be opened and closed, allowing the cryogen, in particular the liquid phase of the cryogen, to flow from the storage vessel into the volume.

[0038] The fact that the inlet valve and the supply valve are "configured" to separate the volume from the consumer and the storage container means, in this case, in particular that the inlet valve and the supply valve can both be closed to separate the volume, thus separating the volume. The evaporator unit is particularly suitable for evaporating the cryogen by introducing heat into the cryogen. The evaporated cryogen can be supplied to the consumer from the separated volume using the supply valve. For this purpose, the supply valve can be opened and closed.

[0039] According to one embodiment, the supply valve is arranged downstream of the inlet valve.

[0040] This means that the supply valve is placed after the inlet valve along the flow direction of the cryogen from the storage vessel to the consumer.

[0041] According to a further embodiment, the volume is provided between the inlet valve and the supply valve.

[0042] The volume can be any hollow space that can be pressurized by evaporating the cryogen. As mentioned previously, the volume can also be referred to as a collector, header, or accumulator.

[0043] According to a further embodiment, the volume is formed by means of one or more pipe loops, a pipeline and / or a storage volume.

[0044] For example, the volume is formed by a pipe loop with a length of 15 to 20 m and a pipe diameter of 200 to 600 mm, in particular up to 400 mm. The volume can comprise a meandering pipe loop. The storage volume can be any container or similar.

[0045] The conveying device further comprises the control and regulating device for controlling the inlet valve and / or the supply valve.

[0046] Preferably, a pressure sensor and a flow sensor are provided downstream of the supply valve. The pressure sensor and the flow sensor provide sensor signals to the control and regulation device, so that the control and regulation device can control the supply valve in such a way that the pressure in the volume is reduced to the supply pressure suitable for the consumer as the vaporized cryogen flows out.

[0047] The embodiments and features described for the method apply accordingly to the proposed conveying device and vice versa.

[0048] "One" in this case is not necessarily to be understood as limiting the number to exactly one element. Rather, multiple elements, such as two, three, or more, can also be considered. Any other counting term used here should also not be understood as requiring a precise limitation to the corresponding number of elements. Rather, numerical deviations upwards and downwards are possible.

[0049] Further possible implementations of the method and / or the conveying device also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the method and / or the conveying device.

[0050] Further advantageous embodiments of the method and / or the conveying device are the subject of the dependent claims and the exemplary embodiments of the method and / or the conveying device described below. The method and / or the conveying device are explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic view of an embodiment of a conveying arrangement for conveying hydrogen; Fig. 2 shows a diagram illustrating the functionality of the conveyor arrangement according to Fig. 1 schematically; and Fig. 3 shows a schematic block diagram of an embodiment of a method for supplying a consumer with a cryogen from a storage container.

[0051] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

[0052] The Fig. 1 shows a schematic view of an embodiment of a delivery arrangement 1 for delivering hydrogen H2 from a storage container 2 to a consumer 3. The delivery arrangement 1 is designed to continuously supply the consumer 3, independent of movements of the storage container 2, with gaseous hydrogen H2 at a constant supply pressure of a maximum of 6 bara, preferably from 1 to 2.5 bara, and a temperature of approximately +10 to +25 °C. The delivery arrangement 1 can also be referred to as a hydrogen delivery arrangement. The storage container 2 and / or the consumer 3 can be part of the delivery arrangement 1.

[0053] The conveyor assembly 1 is particularly suitable for mobile applications. Preferably, the conveyor assembly can be part of a vehicle, in particular part of a land vehicle, a watercraft, or an aircraft. For example, the conveyor assembly 1 is part of a ship, such as a passenger ferry, a motor vehicle, for example a truck or commercial vehicle, or the like.

[0054] The storage container 2 can also be referred to as a storage tank. Multiple storage containers 2 can also be provided (not shown). The storage container 2 can be constructed rotationally symmetrically to a central or symmetry axis 4. The symmetry axis 4 can be oriented perpendicular to a direction of gravity g. This means that the storage container 2 is positioned lying down or horizontally. However, the storage container 2 can also be positioned upright or vertically. In this case, the symmetry axis 4 is oriented parallel to the direction of gravity g.

[0055] Storage vessel 2 is designed to hold liquid hydrogen H2 (boiling point at 1 bara: 20.268 K = -252.882 °C). Therefore, storage vessel 2 can also be referred to as a hydrogen storage vessel or hydrogen storage tank. However, storage vessel 2 can also be used for other cryogenic liquids. Examples of cryogenic fluids or liquids, or cryogens for short, in addition to the aforementioned liquid hydrogen H2, include liquid helium He (boiling point at 1 bara: 4.222 K = -268.928 °C), liquid nitrogen N2 (boiling point at 1 bara: 77.35 K = -195.80 °C), or liquid oxygen O2 (boiling point at 1 bara: 90.18 K = -182.97 °C).

[0056] The liquid hydrogen H2 is contained in the storage tank 2. As long as the hydrogen H2 is in the two-phase region, a gas zone 5 with vaporized hydrogen H2 and a liquid zone 6 with liquid hydrogen H2 can be provided in the storage tank 2. After being filled into the storage tank 2, the hydrogen H2 therefore has two phases with different states of aggregation, namely liquid and gaseous. This means that in the storage tank 2 there is a phase boundary 7 between the liquid hydrogen H2 and the gaseous hydrogen H2. A pressure sensor 8 is assigned to the storage tank 2 and can detect the pressure in the storage tank 2. The pressure in the storage tank 2 is approximately 3.5 bara. The pressure in the storage tank 2 is essentially constant.

[0057] Multiple consumers 3 can be provided. However, only one consumer 3 will be discussed below. Consumer 3 is preferably a fuel cell. A "fuel cell" is understood here to be a galvanic cell that converts the chemical reaction energy of a continuously supplied fuel, in this case hydrogen H2, and an oxidizing agent, in this case oxygen, into electrical energy. The resulting electrical energy can, for example, be used to drive an electric motor (not shown). For stable operation of consumer 3, it is necessary, as previously mentioned, to supply consumer 3 with gaseous hydrogen at a defined supply pressure.

[0058] In mobile applications, movements of the liquid hydrogen H2 contained in the storage tank 2 must be expected. In a horizontally arranged cylindrical storage tank 2, the inertia of the liquid hydrogen H2 and the curvature of the storage tank 2 resulting from its horizontal installation promote large-scale sloshing of the liquid hydrogen H2 both on its cylindrical outer wall and at its ends.

[0059] This sloshing, also known as sloshing, leads to a cooling of the gas phase in the gas zone 5 above the liquid hydrogen H2 and thus to a pressure reduction of a gas cushion forming above the liquid hydrogen H2. Depending on the movements of the storage vessel 2, this can have adverse effects on the supply pressure available for the operating components of the consumer 3, which can lead to unstable operation of the consumer 3.

[0060] To provide the appropriate supply pressure for consumer 3, it is possible to use a liquid-cooled and liquid-bearing pump for pumping liquid hydrogen H2. However, such a pump has moving parts. Furthermore, intermittent operation of the pump can lead to bubble formation in the liquid hydrogen H2 due to its heating. This can cause the pump to malfunction. Alternatively, the hydrogen H2 can first be evaporated and then brought to the required supply pressure using a compressor. However, this is energetically unfavorable.

[0061] Furthermore, the storage tank 2 can also be operated directly at the supply pressure. In this case, an equilibrium is established in the storage tank 2 with the liquid phase and the gas phase layered above it. Due to the low surface tension of liquid hydrogen, movement of the storage tank 2, for example when arranged on or near a vehicle as mentioned above, causes the liquid phase and the gas phase to mix with one another, and thus the liquid hydrogen H2 cools the warmer gaseous hydrogen H2. Maintaining the supply pressure is then not possible until an equilibrium is established between the temperature of the liquid hydrogen H2 and the gaseous hydrogen H2. These aforementioned problems are to be solved with the aid of the delivery arrangement 1.

[0062] The conveying arrangement 1 comprises a conveying device 9. In contrast to the conveying arrangement 1, the storage container 2 and / or the consumer 3 are preferably not part of the conveying device 9. However, it is not excluded that the storage container 2 and / or the consumer 3 are part of the conveying device 9.

[0063] The conveying device 9 comprises a line 10 that exits the storage tank 2 below the phase boundary 7, i.e., in the region of the liquid zone 6. The line 10 can be used to feed the liquid hydrogen H2 from the storage tank 2 to an inlet valve V2 of the conveying device 9. An evaporator unit 11 is located downstream of the inlet valve V2. The evaporator unit 11 is suitable for evaporating the liquid hydrogen H2 by introducing heat Q.

[0064] The inlet valve V2 is operatively connected to a control and regulating device 13 of the conveying device 9 via an operative connection 12. The operative connection 12 can be a data connection. The operative connection 12 can be wireless or wired. The control and regulating device 13 is suitable for opening and closing the inlet valve V2 as needed. The control and regulating device 13 can also be suitable for receiving and / or evaluating sensor signals from the pressure sensor 8.

[0065] A header 14 leads from the inlet valve V2 to a supply valve V1. The evaporator unit 11 can be part of the header 14. The header 14 can be routed through the evaporator unit 11. The evaporator unit 11 can be connected into the header 14. A "header" is understood in particular to be an enclosed volume that can be pressurized. In particular, a "header" is understood here to be a volume located between the valves V1, V2 that can be pressurized.

[0066] The header can also be referred to as a volume, pressure reservoir, or collector. The terms "header," "volume," "pressure reservoir," or "collector" can therefore be interchanged. The header 14 can be implemented, for example, as one or more pipe loops with a length of, for example, 15 to 20 m and a diameter of 200 to 250 mm. The pipe loop can be meandering. A pressure of 3 to 10 bara can prevail in the header 14.

[0067] The header 14 is also part of the conveying device 9. A pressure sensor 15 for monitoring the pressure of the header 14 is connected to the header 14. The pressure sensor 15 is located in the header 14 downstream of the evaporator unit 11 and upstream of the supply valve V1. The terms "downstream" and "upstream" are to be understood with regard to a flow direction of the hydrogen H2 from the storage container 2 to the consumer 3. The pressure sensor 15 can communicate with the control and regulating device 13 such that the control and regulating device 13 receives and / or evaluates sensor signals from the pressure sensor 15.

[0068] The supply valve V1 is coupled to the control and regulation device 13 via an active connection 16. The active connection 16 can be a data connection. The active connection 16 can be wireless or wired. The control and regulation device 13 is suitable for opening and closing the supply valve V1 as needed.

[0069] Downstream of the supply valve V1 are a line 17 and a distributor 18, which distributes the gaseous hydrogen H2 among several consumers 3. If only one consumer 3 is provided, the distributor 18 can be omitted. The pressure in line 17 and / or in the distributor 18 is between 1 and 2.5 bara, thus providing a suitable supply pressure for the consumer 3. The pressure in the header 14 is therefore significantly higher than the pressure in line 17 and / or the distributor 18.

[0070] Line 17 has a pressure sensor 19, which is coupled to the control and regulating device 13 via an operative connection 20. Line 17 also includes a flow sensor 21, which is coupled to the control and regulating device 13 via an operative connection 22. The control and regulating device 13 is configured to evaluate sensor signals from the pressure sensor 19 and / or the flow sensor 21 and to receive them via the operative connections 20, 22.

[0071] The functionality of the conveyor arrangement 1 or the conveyor device 9 is described below with reference to the Fig. 2 which shows a diagram in which a pressure p in the storage tank 2 or in the header 14 and a load or load requirement L of the consumer 3 are plotted over time t.

[0072] In the Fig. 2The time t is plotted in seconds on the right-hand axis. The pressure p in the storage tank 2 or in the header 14 is plotted in bar and the load requirement L of the consumer 3 is plotted in percent on the vertical axis. A pressure p14 prevailing in the header 14 is shown with a solid line. A pressure p2 prevailing in the storage tank 2, which is essentially constant, is illustrated with a dash-dotted line. A dashed line 23 represents an opening and closing behavior of the supply valve V1. A double dash-dotted line 24 represents an opening and closing behavior of the inlet valve V2. The load requirement L of the consumer 3 is shown with a dotted line.

[0073] At a time t0, both valves V1 and V2 are fully open. As long as consumer 3 has a load demand L, inlet valve V2 is open, and supply valve V1 regulates the flow of gaseous hydrogen H2 to consumer 3. This is done based on sensor data from pressure sensor 19 and / or flow sensor 21 with the aid of control and regulation device 13. Evaporator unit 11 evaporates the liquid hydrogen H2 from storage tank 2.

[0074] At a time t1, the load demand L begins to decrease. In line with the decreasing load demand L, the supply valve V1 is closed with a slight delay from a time t2. At a time t3, the load demand L is at zero percent. The supply valve V1 is completely closed with a slight delay from a time t4. At a time t3, the inlet valve V2 is still completely open. At a time t4, the inlet valve V2 is completely closed. From a time t4, consumer 3 is therefore no longer supplied with hydrogen H2. Consumer 3 is only supplied with hydrogen H2 when the load demand L is reached.

[0075] The header 14 now forms a closed volume from time t4 onward. With the help of the evaporator unit 11, the header 14 can now be pressurized by evaporating the liquid hydrogen H2 from the storage tank 2. For this purpose, the evaporator unit 11 introduces heat Q into the liquid hydrogen H2. The evaporation of the hydrogen H2 is indicated in the diagram by a hatched area 25. At a time t5, the hydrogen H2 in the header 14 and in the evaporator unit 11 has completely evaporated, and, as previously mentioned, a pressure of 3 to 10 bara prevails in the header 14.

[0076] The hatched area 25 represents, in particular, the pressure buildup due to the re-evaporation of the liquid hydrogen H2 still present in the evaporator unit 11. During normal operation, the evaporator unit 11 is not completely filled with gas; rather, a liquid level results in the tubes of the evaporator unit 11 due to the load and heat transfer. This liquid level of the liquid hydrogen H2 is used to build up the pressure. At time t5, all of the hydrogen H2 in the evaporator unit 11 and in the header 14 has evaporated.

[0077] At any time t6, at which both valves V1, V2 are still closed, a load request L is made by consumer 3. The supply valve V1 is opened with a slight delay at a time t7 and, based on sensor data from the pressure sensor 19 and the flow sensor 21, is controlled via the control and regulating device 13 in such a way that consumer 3 is supplied with gaseous hydrogen H2 at a suitable supply pressure as previously mentioned. The hydrogen H2 stored in the header 14 enables rapid start-up of consumer 3, as shown in the Fig. 2 is indicated by a hatched area 26.

[0078] Since a high pressure p14 now prevails in the header 14 at time t6, it is possible to immediately supply the consumer 3 with gaseous hydrogen H2. It is no longer necessary to first fill the evaporator unit 11 and evaporate the liquid hydrogen H2 at the load demand L. At time t8, the load demand is at 100 percent. The supply valve V1 is fully open with a slight delay at time t9. The inlet valve V2 is still closed at time t9.

[0079] At a time t10, the pressure in the header 14 falls below the pressure in the storage tank 2. With a slight delay, the inlet valve V2 can be reopened at a time t11 to supply the evaporator unit 11 and / or the header 14 with liquid hydrogen H2 from the storage tank 2. The supply of the consumer 3 with the appropriate supply pressure can then again be effected via the supply valve V1.

[0080] The Fig. 3 shows a schematic block diagram of an embodiment of a method for supplying the consumer 3 with hydrogen H2 from the storage container 2. The method is carried out with the aid of the conveying arrangement 1 or the conveying device 9.

[0081] In the method, in a step S1, a portion of the hydrogen H2 from the storage tank 2 is introduced into the header 14, which can be separated from the consumer 3 and the storage tank 2. For this purpose, the inlet valve V2 is opened. In a step S2, the header 14 is separated from the consumer 3 and the storage tank 2. For this purpose, the supply valve V1 is closed during step S2. During step S2, the inlet valve V2 located upstream of the supply valve V1 is also closed.

[0082] In a step S3, the hydrogen H2 in the separated header 14 is evaporated so that the header 14 is subjected to a pressure p14, which is higher than the pressure p2 prevailing in the storage container 2. During step S3, heat Q is introduced into the liquid hydrogen H2 in the header 14 with the aid of the evaporator unit 11 in order to completely evaporate the liquid hydrogen H2 in the header 14.

[0083] In a step S4, when a load demand L of consumer 3 is met, the vaporized hydrogen H2 is discharged from the header 14 to the consumer 3. During step S4, the pressure p14 prevailing in the header 14 is reduced to the supply pressure suitable for consumer 3 by means of the supply valve V1 as the hydrogen H2 is discharged from the header 14. The supply pressure suitable for consumer 3 is lower than the pressure p2 prevailing in the storage tank 2.

[0084] During step S4, the supply valve V1 is opened depending on the load demand L of the consumer 3. The supply valve V1 is controlled by the control and regulating device 13 based on sensor signals from the pressure sensor 19 and / or the flow sensor 21 arranged downstream of the supply valve V1.

[0085] The inlet valve V2 remains closed as long as the pressure p14 in the header 14 is greater than the pressure p2 prevailing in the storage tank. The inlet valve V2 opens as soon as the pressure p14 in the header 14 drops below the pressure p2 prevailing in the storage tank.

[0086] Although the present invention has been described using exemplary embodiments, it can be modified in many ways. Reference symbols used

[0087] 1Conveying arrangement 2Storage tank 3Consumer 4Symmetry axis 5Gas zone 6Liquid zone 7Phase boundary 8Pressure sensor 9Conveying device 10Line 11Evaporator unit 12Active connection 13Control and regulation device 14Header / volume 15Pressure sensor 16Active connection 17Line 18Distributor 19Pressure sensor 20Active connection 21Flow sensor 22Active connection 23Line 24Line 25Area 26Area gGravity direction H2Hydrogen / Cryogen LLoad requirement pPressure p2Pressure p14Pressure QHeat S1Step S2Step S3Step S4Step tTime t0Time t1Time t2Time t3Time t4Time t5Time t6Time t7Time t8Time t9Time t10Time t11Time V1Supply valve V2Inlet valve

Claims

1. Method for supplying a consumer (3) with a cryogen (H2) from a storage tank (2), comprising the following steps: a) introducing (S1) part of the cryogen (H2) from the storage tank (2) into a volume (14) that can be closed off from the consumer (3) and from the storage tank (2), b) closing off (S2) the volume (14) from the consumer (3) and from the storage tank (2) by first closing a supply valve (V1) arranged between the volume (14) and the consumer (3), and then closing an inlet valve (V2) arranged between the storage tank (2) and the volume (14), c) vaporizing (S3) the cryogen (H2) in the volume (14) so as to subject the volume (14) to a pressure (p14) which is higher than a pressure (p2) prevailing in the storage tank (2), characterized by d) discharging (S4) the vaporized cryogen (H2) from the volume (14) to the consumer (3) when the consumer (3) has a load requirement (L) by opening the supply valve (V1), wherein, when the supply valve (V1) is open, the inlet valve (V2) is opened as soon as the pressure (p14) in the volume (14) falls below the pressure (p2) prevailing in the storage tank (2).

2. Method according to claim 1, wherein during step d), the pressure (p14) prevailing in the volume (14) is reduced to a supply pressure suitable for the consumer (3) when the cryogen (H2) is discharged from the volume (14) using the supply valve (V1).

3. Method according to claim 2, wherein the supply pressure suitable for the consumer (3) is less than the pressure (p2) prevailing in the storage tank (2).

4. Method according to either claim 2 or claim 3, wherein during step d), the supply valve (V1) is opened depending on the load requirement (L) of the consumer (3).

5. Method according to any of claims 2 - 4, wherein during step d), the supply valve (V1) is controlled using an open-loop and closed-loop control device (13) based on sensor signals from a pressure sensor (19) arranged downstream of the supply valve (V1) and / or sensor signals from a flow sensor (21).

6. Method according to any of claims 1 - 5, wherein the inlet valve (V2) is closed as long as the pressure (p14) in the volume (14) is greater than the pressure (p2) prevailing in the storage tank (2).

7. Method according to any of claims 1-6, wherein during step c), heat (Q) is introduced into the cryogen (H2) using a vaporizer unit (11) in order to vaporize it.

8. Conveyor device (9) for supplying a consumer (3) with a cryogen (H2) from a storage tank (2), comprising an inlet valve (V2), which is arranged between the storage tank (2) and a volume (14) which can be closed off from the consumer (3) and from the storage tank (2), a supply valve (V1), which is arranged between the volume (14) and the consumer (3), a vaporizer unit (11), and an open-loop and closed-loop control device (13), wherein the open-loop and closed-loop control device (13) is designed to control the inlet valve (V2) in such a way that the inlet valve (V2) introduces a part of the cryogen (H2) from the storage tank (2) into the volume (14), wherein the open-loop and closed-loop control device (13) is designed to control the inlet valve (V2) and the supply valve (V1) in such a way that the inlet valve (V2) and the supply valve (V1) close off the volume (14) from the consumer (3) and from the storage tank (2), wherein the open-loop and closed-loop control device (13) is designed to first close the supply valve (V1) and then to close the inlet valve (V2), wherein the vaporizer unit (11) is designed to vaporize the cryogen (H2) accommodated in the closed-off volume (14) so as to subject the closed-off volume (14) to a pressure (p14) which is higher than a pressure (p2) prevailing in the storage tank (2), wherein the open-loop and closed-loop control device (13) is designed to control the supply valve (V1) in such a way that the supply valve discharges the vaporized cryogen (H2) from the closed-off volume (14) to the consumer (3) when the consumer (3) has a load requirement (L), and wherein the open-loop and closed-loop control device (13) is designed, when the supply valve (V1) is open, to open the inlet valve (V2) as soon as the pressure (p14) in the volume (14) falls below the pressure (p2) prevailing in the storage tank (2).

9. Conveying device according to claim 8, wherein the supply valve (V1) is arranged downstream of the inlet valve (V2).

10. Conveying device according to either claim 8 or claim 9, wherein the volume (14) is provided between the inlet valve (V2) and the supply valve (V1).

11. Conveying device according to any of claims 8 - 10, wherein the volume (14) is formed using one or more pipe loops, a pipeline, and / or a storage volume.