CRYOGENIC STORAGE SYSTEM

Abstract

A cryostorage system that includes: a cryocontainer operable to store hydrogen, the cryocontainer having an inner tank and an outer container; at least one cryopump, arranged in the inner tank, to deliver liquid hydrogen and/or gaseous hydrogen in one or more stages via an extraction line to a consumer at a pressure greater than a pressure in the inner tank; and a filling interface to facilitate filling of the inner tank at least in part via the extraction line and a spring-loaded non-return valve into the inner tank.

Claims

1. A cryostorage system, comprising: a cryocontainer operable to store hydrogen, the cryocontainer having an inner tank and an outer container; at least one cryopump, arranged in the inner tank, to deliver liquid hydrogen and/or gaseous hydrogen in one or more stages via an extraction line to a consumer at a pressure greater than a pressure in the inner tank; and a filling interface to facilitate filling of the inner tank at least in part via the extraction line and a spring-loaded non-return valve into the inner tank.

2. The cryostorage system of claim 1, wherein the spring-loaded non-return valve is arranged in an inlet line into the inner tank, which branches off from a line that is formed by a pressure line taking off the delivered deliver liquid hydrogen and/or gaseous hydrogen by the cryopump and the extraction line.

3. The cryostorage system of claim 1, wherein the cryopump comprises a linear pump which facilitates a left delivery flow and a right delivery flow on both sides thereof.

4. The cryostorage system of claim 3, wherein the left delivery flow and/or the right delivery flow of the linear pump is selectively operable to deliver the gaseous hydrogen or the liquid hydrogen via a check valve adjacent to a pump for switching from gaseous hydrogen to liquid hydrogen.

5. The cryostorage system of claim 1, further comprising a heat exchanger operable to heat the hydrogen.

6. The cryostorage system of claim 5, wherein the cryocontainer is operable such that a partial flow of the heated hydrogen from the heat exchanger, is returned via a gas return line into the inner tank to increase pressure in the inner tank via a check valve for the return of gaseous hydrogen to the inner tank.

7. The cryostorage system of claim 6, further comprising a pressure reducer with a downstream pressure safety valve, arranged in the gas return line for the return gaseous hydrogen to the inner tank.

8. The cryostorage system of claim 1, further comprising a buffer container for heated hydrogen arranged between the cryopump and the consumer.

9. A cryostorage system, comprising: a cryocontainer operable to store hydrogen, the cryocontainer having an inner tank and an outer container; at least one cryopump, arranged in the inner tank, to deliver liquid hydrogen and/or gaseous hydrogen in one or more stages via an extraction line to a consumer at a pressure greater than a pressure in the inner tank; and a filling interface to facilitate filling of the inner tank at least in part via the extraction line and a shuttle valve into the inner tank.

10. The cryostorage system of claim 9, wherein the shuttle valve is arranged in a pressure line of the cryopump, which takes off delivered deliver liquid hydrogen and/or gaseous hydrogen.

11. The cryostorage system of claim 10, wherein the pressure line which takes off the delivered liquid hydrogen and/or gaseous hydrogen joins at the shuttle valve with an inlet line into the inner tank so that at the shuttle valve, in response to an operating state of the shuttle valve, either access to the pressure line is opened and access to the inlet line is closed, or access to the pressure line is closed and access to the inlet line is opened.

12. The cryostorage system of claim 11, wherein the shuttle valve has an access to the extraction line, which is opened both when access to the pressure line is opened and when access to the inlet line is opened.

13. The cryostorage system of claim 11, wherein the shuttle valve has an integrated float, an inherent weight of the integrated float keeping the float in a lower end position so that the inlet line for filling the inner tank is uncovered.

14. The cryostorage system of claim 13, wherein the integrated float is raised by delivery flow when the cryopump is in an operating state so that it blocks the inlet line to the inner tank and the delivery flow is pumped only to the consumer.

15. The cryostorage system of claim 9, wherein the cryopump comprises a linear pump which facilitates a left delivery flow and a right delivery flow on both sides thereof.

16. The cryostorage system of claim 15, wherein the left delivery flow and/or the right delivery flow of the linear pump is selectively operable to deliver the gaseous hydrogen or the liquid hydrogen via a check valve adjacent to a pump for switching from gaseous hydrogen to liquid hydrogen.

17. The cryostorage system of claim 9, further comprising a heat exchanger operable to heat the hydrogen.

18. The cryostorage system of claim 17, wherein the cryocontainer is operable such that a partial flow of the heated hydrogen from the heat exchanger, is returned via a gas return line into the inner tank to increase pressure in the inner tank via a check valve for the return of gaseous hydrogen to the inner tank.

19. The cryostorage system of claim 18, further comprising a pressure reducer with a downstream pressure safety valve, arranged in the gas return line for the return gaseous hydrogen to the inner tank.

20. The cryostorage system of claim 9, further comprising a buffer container for heated hydrogen arranged between the cryopump and the consumer.

Description

DRAWINGS

[0024] One or more embodiments of the present disclosure will be illustrated by way of example in the drawings and explained in the description hereinbelow.

[0025] FIG. 1 illustrates a schematic representation of a cryostorage system, in accordance with one or more embodiments.

[0026] FIG. 2 illustrates a schematic representation of a part of the cryostorage system of FIG. 1, in another alternative embodiment.

[0027] FIG. 3 illustrates a schematic representation of a part of the cryostorage system of FIG. 1, in another alternative embodiment.

[0028] FIG. 4 illustrates a schematic representation of a cryostorage system, in accordance with another alternative embodiment.

[0029] FIG. 5 illustrates a schematic representation of a cryostorage system, in accordance with another alternative embodiment.

[0030] FIG. 6 illustrates a schematic representation of a cryostorage system, in accordance with another alternative embodiment.

[0031] FIG. 7 illustrates a schematic representation of a detail of a shuttle valve of the cryostorage system of FIG. 6 in a first operating state.

[0032] FIG. 8 illustrates a schematic representation of a detail of a shuttle valve of a cryostorage system of FIG. 6 in a second operating state.

DESCRIPTION

[0033] FIG. 1 represents a cryostorage system in accordance with one or more embodiments, which comprises a cryocontainer that itself comprises an inner tank 1 and an outer container 2, with an insulation space serving as an intermediate space between the inner tank 1 and the outer container 2.

[0034] The cryostorage system can deliver cryogenic liquid at very low temperature from the inner tank 1 via a power-controlled pressure-increasing cryopump 21 and a pressure line 22 of the cryopump, which joins with an extraction line 27 and debouches at a line connection 3 into a supply line 4, to a consumer 5.

[0035] The cryopump 21 is preferably fully surrounded by cryogenic fluid, i.e. the drive of the pump 21 also works at very low temperatures, which allows a low electrical power consumption for the cold gas compression.

[0036] From the inner tank 1 into the extraction line 27, furthermore, gas can flow by opening a GH.sub.2 tank valve 15 and/or liquid can flow by opening an LH.sub.2 tank valve 16. Gas may in this case be extracted from the inner tank 1 via a combined safety and gas extraction line 18. A non-return valve 17 for the gas extraction may be provided downstream of the GH.sub.2 tank valve 15. Gas may also be let out from the combined safety and gas extraction line 18 through a pressure relief safety valve 19.

[0037] Downstream of the extraction from the inner tank 1, in particular, downstream of the cryopump 21 and downstream of the tank valves 15, 16, the cryogenic fluid (i.e., liquid hydrogen) is fed through a heat exchanger 7 while being fully converted into the gas phase by supplying heat, preferably via cooling water 11 of the consumer 5, and at the same time heated sufficiently for the consumer 5. The cryopump 21 delivers the hydrogen on demand to the consumer 5 at a greater pressure than in the inner tank 1. The extraction of fuel from the cryostorage system reduces the pressure and the amount of fuel in the inner tank 1 thereof.

[0038] In order to compensate for a fluctuating delivery power of the cryopump 21 possibly occurring, a buffer container 8 for heated hydrogen may additionally be arranged between the pump 21 and the consumer 5, particularly in the supply line 4. A check valve 12 for the H.sub.2 supply to the consumer 5 may be arranged in the supply line 4 upstream of the consumer 5.

[0039] The cryostorage system can be filled via a filling interface 14. The filling may take place in part via the extraction line 27 and an inlet line 20 into the inner tank 1, preferentially into the region of gaseous hydrogen of the inner tank 1.

[0040] As represented in FIGS. 1 through 5, a spring-loaded non-return valve 25 may be arranged in the inlet line 20 into the inner tank 1, the inlet line 20 branching off from a line that is formed by a pressure line 22 taking off the medium delivered by the cryopump 21 and the extraction line 27.

[0041] The filling may then take place via the extraction line 27 and via the spring-loaded non-return valve 25 and via the inlet line 20 into the inner tank 1.

[0042] Should there be a need to increase or maintain the pressure in the inner tank 1 of the cryostorage system, gas may be transferred back into the inner tank 1 via a valve 13 in a gas return line 6, which branches off at the line connection 3 from the extraction line 27 downstream of the heat exchanger 7. In order to limit the pressure for the gas return into the inner tank 1, a pressure reducer 9 with a downstream pressure safety valve 10 may if required be installed in the gas return line 6.

[0043] Whereas FIG. 1 shows a one-stage pressure increase with gas return, FIG. 2 illustrates a variant embodiment having a series pump arrangement for a two-stage pressure increase with gas return.

[0044] Should there be a need for very high supply pressures (e.g., supercritical, greater than 20 bar), at least one further cryopump stage may be connected in series downstream of the first cryopump stage (cf. FIG. 2). In this case, the final pressure of the first cryopump 21 becomes the intake pressure of the second cryopump 21. The series interconnection allows greater final pressures together with a low energy consumption for the compression of the cold gas. Alternatively, a cryopump 21 and the heat exchanger 7 may also be followed by a heated compressor outside the tank system for the final compression.

[0045] FIG. 3 illustrates a particular embodiment of the pump instead of the delivery pump, in the form of a linearly driven cryopump 21 displacing on both sides, having two opposite displacement working spaces each with a separate intake and outlet port for fluid delivery on both sides. The cryopump 21 is therefore configured as a linear pump which delivers the stored medium on both sides, in FIG. 3 only in the form of the liquid medium.

[0046] FIG. 4 illustrates an variant embodiment of a linearly driven cryopump 21 displacing on both sides with separate intake ports (as in FIG. 3), but with a check valve 23 on one side (in FIG. 4 on the left side of the linear delivery pump) for the selective delivery of liquid or gas. Only a liquid delivery takes place on the opposite second side of the pump. In other regards, the cryostorage system is configured in the same way as the variants of FIGS. 1 through 3.

[0047] By incorporating additional equipment in the inner tank (cryovalve(s), pipeline(s)), gas or liquid may selectively flow to the respective intake port by a controlled alternate valve switching setting. By the valve controller 23, for example, in FIG. 4, the ratio of gas to liquid extraction can be varied and therefore the ratio of mass flow to the consumer 5 to the pressure reduction in the inner tank 1 may therefore also be varied. The possibility of selection between gas or liquid extraction offers an additional degree of freedom since the ratio of mass flow to the consumer 5 to the pressure reduction in the inner tank 1 is therefore no longer approximately constant and the respective quantity may be varied not only via the pump frequency, but in each case flexibly.

[0048] When the valve 23 is open, LH.sub.2 floods the tube as far as the intake port of the cryopump 21 and the gas extraction line 24 up to the height of the LH.sub.2 level (as a consequence of the hydrostatic equilibration). If the valve 23 is closed, firstly the residual LH.sub.2 is delivered from the pipeline of the intake port before gaseous hydrogen flows in from above through the gas extraction line 24 to the intake port.

[0049] Gas can therefore be extracted from the inner tank 1 via a gas extraction line 24 as an extended intake port of the cryopump 21. Liquid or gas can selectively be delivered from the inner tank 1 by the pump 21 through a check valve 23 near to the pump for switching from LH.sub.2 to GH.sub.2.

[0050] Should a linear pump (FIGS. 3 through 6) which delivers on both sides be used, there are different possible variants for the extraction. The left and right delivery flows may for example both deliver only LH.sub.2, i.e. liquid hydrogen, or one of the two sides, for example, the left side, may selectively deliver GH.sub.2 or LH.sub.2 and the other side may deliver only LH.sub.2, or both sides may selectively deliver GH.sub.2 or LH.sub.2, i.e. gas or liquid, so that the medium delivered is variable overall from 100% GH.sub.2 to 100% LH.sub.2 delivery.

[0051] FIG. 4 illustrates a variant of these possibilities with a linearly driven cryopump 21 displacing on both sides with a connected intake port, with selective delivery of liquid or gas on one side, namely in this case the left side, of the pump.

[0052] FIG. 5 illustrates a variant of a linearly driven cryopump 21 displacing on both sides with separate intake ports, both of which are adapted selectively for the delivery of liquid and/or gas. A check valve 23 for switching from LH.sub.2 to GH.sub.2 is respectively arranged on each of the two intake ports of the cryopump 21.

[0053] In the arrangements described in this disclosure, a spring-loaded non-return valve 25 in the filling line in the inner tank in each case allows filling while circumventing the pump 21, and preferentially into the gas space. In this case, for opening the spring-loaded non-return valve 25, it is necessary for the filling pressure to be greater than the maximum delivery pressure of the cryopump 21. Although the non-return valve 25 creates an additional flow resistance for the filling, it avoids one for the delivery flow of the cryopump 21 to the consumer 5.

[0054] FIG. 6 illustrates another configuration of the valves for the filling, namely a shuttle valve 26, which is preferentially arranged in the inner tank 1 and is represented in FIG. 6 with a float position for extraction by the cryopump 21. A spring-loaded non-return valve 25 is not necessary in this embodiment. The shuttle valve 26 is arranged in the pressure line 22 of the cryopump 21, which takes off the delivered medium, the pressure line 22 taking off the delivered medium joining, at the shuttle valve 26, with the inlet line 20 into the inner tank 1 so that at the shuttle valve 26, depending on the operating state of the shuttle valve 26, either the access to the pressure line 22 is opened and the access to the inlet line 20 is closed, or the access to the pressure line 22 is closed and the access to the inlet line 20 is opened.

[0055] The shuttle valve therefore has an access to the extraction line 27, which is opened both when the access to the pressure line 22 is opened and when the access to the inlet line 20 is opened.

[0056] The shuttle valve 26 with an integrated float 28 (cf. FIGS. 6 through 8) represents one embodiment of switching between extraction and filling. The shuttle valve 26 is arranged at the connecting point between the pressure line 22, the extraction line 27 and the inlet line 20 into the inner tank 1.

[0057] During filling (FIG. 7), the float 28 remains in the lower end position due to its inherent weight and uncovers the inlet line 20 for filling the inner tank. By starting the cryopump 21, the float 28 is raised/moved by the delivery flow in such a way that it blocks the inlet of the filling line to the inner tank 1, i.e. the inlet line 20 (FIG. 8), so that the delivery flow is pumped only to the consumer 5.

[0058] The advantages of this alternative are that the filling can be performed with a lower flow resistance and the filling pressure and maximum delivery pressure of the cryopump 21 are independent of one another. However, the float 28 integrated in the shuttle valve 26 creates an additional flow resistance for the delivery flow of the cryopump 21 to the consumer 5.

[0059] Both configurations of the switching function, i.e. a spring-loaded non-return valve 25 and a shuttle valve 26, allow pressure relief of the adjacent lines and of the cryopump 21 into the inner tank 1 when contained fluid expands by heating.

[0060] FIG. 7 therefore illustrates the flow in the shuttle valve 26 during filling. The inherent weight of the float 28 keeps the float 28 in a lower end position during filling, so that the inlet line 20 for filling the inner tank 1 is uncovered.

[0061] FIG. 8 illustrates the flow in the shuttle valve 26 during extraction via the cryopump 21. When the cryopump 21 is started, the float 28 is raised from the valve seat 29 by the delivery flow, so that it blocks the inlet line 20 to the inner tank 1 and the delivery flow is pumped only to the consumer 5.

[0062] The terms coupled, attached, or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, thermal, optical, electromagnetic, electromechanical, or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0063] Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments can be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.

LIST OF REFERENCE SYMBOLS

[0064] 1 inner tank of the primary storage system [0065] 2 outer container [0066] 3 line connection [0067] 4 supply line [0068] 5 consumer [0069] 6 gas return line [0070] 7 heat exchanger [0071] 8 buffer container [0072] 9 pressure reducer [0073] 10 pressure safety valve [0074] 11 cooling water circuit [0075] 12 check valve for H.sub.2 supply to the consumer [0076] 13 check valve for gas return to the inner tank [0077] 14 interface for filling [0078] 15 GH.sub.2 tank valve [0079] 16 LH.sub.2 tank valve [0080] 17 non-return valve for the gas extraction [0081] 18 combined safety and gas extraction line [0082] 19 pressure relief safety valve [0083] 20 LH.sub.2 inlet line into the inner tank [0084] 21 cryopump(s) [0085] 22 pressure line of the cryopump [0086] 23 check valve close to the pump for switching from LH.sub.2 to GH.sub.2 [0087] 24 gas extraction line as extended intake port of the cryopump [0088] 25 further non-return valve [0089] 26 shuttle valve [0090] 27 extraction line [0091] 28 float [0092] 29 valve seat