HYDROGEN TANK, METHOD OF COOLING A HYDROGEN TANK, AND VEHICLE HAVING A HYDROGEN DRIVE AND HYDROGEN TANK

Abstract

A hydrogen tank having a tank structure at least partially delimiting a tank space and comprising a cooling shield formed in a lightweight construction. A conduit system, connected to the tank space, of a pressure relief system for discharging gaseous hydrogen from the tank space is formed in the cooling shield. At least one para-ortho catalyst for accelerated conversion of parahydrogen into orthohydrogen is arranged in the conduit system. A vehicle is provided having a hydrogen drive and such a hydrogen tank. A method for cooling the tank structure of such a hydrogen tank is provided.

Claims

1. A hydrogen tank, comprising a tank structure which at least partially delimits a tank space and comprises a region comprising a cooling shield, a conduit system, connected to the tank space, of a pressure relief system for discharging gaseous hydrogen from the tank space, being formed in the cooling shield, wherein at least one para-ortho catalyst for an accelerated conversion of parahydrogen into orthohydrogen is arranged in the conduit system.

2. The hydrogen tank according to claim 1, wherein the para-ortho catalyst is formed at least partially as an internal coating of at least a part of a boundary of the conduit system.

3. The hydrogen tank according claim 1, wherein the cooling shield has at least two separate material layers between which at least one hollow interspace is formed, which forms at least part of the conduit system.

4. The hydrogen tank according to claim 3, wherein at least one of the material layers has at least one of corrugations or surfaces angled with respect to each other, which at least partially delimit the at least one interspace.

5. The hydrogen tank according to claim 1, wherein the tank structure further has a substructure in which at least one evacuable or evacuated hollow volume is formed for thermal insulation of the tank space.

6. The hydrogen tank according to claim 1, wherein the tank structure is at least partially made of at least one of plastics, fiber-reinforced composite, aluminum, or at least one aluminum alloy.

7. A vehicle having a hydrogen drive, which comprises at least one hydrogen tank according to claim 1 for supplying the hydrogen drive.

8. A method for cooling the tank structure of a hydrogen tank according to claim 1, wherein the method comprises: passing gaseous hydrogen from the tank space of the hydrogen tank through the conduit system containing the at least one para-ortho catalyst, and discharging the hydrogen into an environment of the hydrogen tank.

9. The method according to claim 8, further including a step of introducing the gaseous hydrogen, having a temperature in a range of 30K to 70K, from the tank space into the conduit system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the figures, schematically:

[0035] FIG. 1a shows an exemplary embodiment of a hydrogen tank according to the invention as a tank of a space vehicle during a thrust phase in a longitudinal section;

[0036] FIG. 1b shows the hydrogen tank of FIG. 1a during a ballistic flight phase of the space vehicle;

[0037] FIG. 1c shows the hydrogen tank according to the invention of FIGS. 1a, 1b in cross-section; and

[0038] FIG. 1d shows an advantageous hydrogen tank according to an exemplary embodiment of the present invention in cross-section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] FIG. 1a schematically shows a hydrogen tank 100 according to an exemplary embodiment of the present invention. The hydrogen tank has a tank structure 10 surrounding and delimiting a tank space T. The tank structure 10 comprises a cooling shield 11 in which a conduit system 21 of a pressure relief system 20 is formed. Through the inlet 22 thereof, gaseous hydrogen Wg can flow from the tank space into the conduit system 21 to then flow through the conduit system 21 and to be discharged into an environment of the hydrogen tank 100 through an outlet 23 of the pressure relief system 20. A para-ortho catalyst (not visible in the figure) is arranged in the conduit system 21 for accelerated conversion of parahydrogen into orthohydrogen. The para-ortho catalyst is preferably formed as a coating of at least one region of a boundary of the conduit system 21 in the cooling shield 11. In particular, the catalyst can comprise iron oxide, nickel silicon, chromium trioxide and/or a porous magnetic material and it ensures that parahydrogen in the gaseous hydrogen Wg flowing through the conduit system 21 is partially converted into orthohydrogen. Since the endothermic conversion extracts heat from the cooling shield 11, the tank structure 10 is additionally cooled in this manner and therefore a heat flow (D acting on the hydrogen tank 100 from the outside is at least partially offset. In this manner, pressure relief necessary for regulating the tank pressure can be used for effective cooling so that evaporation losses can be minimized.

[0040] In the present case, the tank space is rotationally symmetrical about an (abstract) central axis X along which the hydrogen tank 100 is shown in section in FIG. 1a.

[0041] The tank space T is bounded here by a tank wall 12 and two tank domes 13a, 13b. The tank wall 12 is formed along a circular cylinder about the central axis X. The tank domes 13a, 13b are each formed as spherical sections through which the central axis X extends. The inlet 22 of the pressure relief system 20 is arranged in the region of extent of the central axis X through that tank dome 13a which, in an intended installation orientation of the hydrogen tank in a vehicle (not shown), is opposite a tank space region in which the liquid hydrogen Wf accumulates under the influence of the earth's gravity or—if the vehicle is equipped for space applications—under the influence of inertia during thrust: This situation is shown in FIG. 1a.

[0042] In contrast, FIG. 1b shows the hydrogen tank 100 installed in the intended installation orientation in a space vehicle (not shown) in a situation in which the space vehicle rotates about the central axis X during a ballistic phase: In this situation, the liquid hydrogen Wf is forced radially outwards with respect to the central axis X and thus against the tank wall 12 due to the centrifugal force.

[0043] In both situations, the liquid hydrogen Wf is spaced apart from the inlet 22 of the pressure relief system 20 into the conduit system 21, preventing it from entering the conduit system.

[0044] The tank structure 10 is shown in FIGS. 1a and 1b in each case in simplified form with two flat layers of material 14a, 14b between which at least one interspace Z is formed. Thus, a lightweight construction of the tank structure is implemented. Preferably, at least one of the flat material layers consists at least partially of a lightweight material such as, for example, plastics, fiber-reinforced composite, aluminum and/or at least one aluminum alloy. Preferably, at least one of the material layers can provide the cooling shield with a load-bearing function.

[0045] As can further be seen in FIGS. 1a and 1b, the interspace Z forms at least part of the conduit system 21 in the embodiment shown.

[0046] FIG. 1c schematically shows the hydrogen tank 100 cut perpendicular to the central axis X and in the region of the tank wall 12 (and also with modified dimensions to illustrate the structure). It is apparent from this illustration that between the material layers 14a and 14b, a corrugated material layer 14c is arranged as a further material layer, the corrugations of which in contact with the material layer 14a arranged further out even delimit a plurality of interspaces Z, of which only two are provided with reference signs in FIG. 2 for the sake of clarity. In contact with the material layer 14b arranged further inwards (in relation to the tank space T or the central axis X), the corrugated material layer 14c delimits further interspaces Zi.

[0047] The respective outer interspaces Z form at least part of the conduit system 21 with the para-ortho catalyst (not shown). When gaseous parahydrogen is passed through the conduit system 21, the outer material layer 14b, in particular, is cooled and thus a heat flow Φ from the outside is at least partially offset. Alternatively or additionally, the further interspaces Zi can form part of the conduit system 21 with the para-ortho catalyst (not shown in the figure).

[0048] In particular, the para-ortho catalyst can comprise one or more region(s) in which it is formed as a respective coating of at least part of one or more respective wall(s) of the interspaces Z and/or the interspaces Zi.

[0049] As an alternative to the corrugated shape (wave shape), the material layer 14c could comprise sections angled with respect to each other, in particular formed in a jagged manner (not shown).

[0050] FIG. 1d schematically illustrates a particularly advantageous hydrogen tank 100′ according to a further exemplary embodiment of the present invention in a cross-sectional view. The hydrogen tank 100′ can in particular be spherical or have a circular-cylindrical tank wall; the cross-section shown is taken perpendicular to its central axis X in the present case.

[0051] The hydrogen tank 100′ has a tank structure 10′ which has a cooling shield 11 which is formed analogously to the cooling shield 11 of the tank structure 100 shown in FIG. 1c and is therefore designated here in the same way and will not be described again.

[0052] Moreover, the tank structure 10′ of the hydrogen tank 100′ comprises material layers 15a and 15b each on a side of the cooling shield 11 facing the tank space T (thus, between the tank space T and the cooling shield 11) and material layers 17a and 17b on a side of the cooling shield 11 facing away from the tank space (thus, further out than the cooling shield 11 with respect to the tank space).

[0053] The material layers 15a and 17b in the present case are each corrugated (wave shaped) so that they are in contact with the respective adjacent material layers 14a, 15b and 14b, 17a and together with these respective material layers delimit cavities Ha, Hi, only two of which are marked with reference signs in FIG. 1d for the sake of clarity. Inside and outside the cooling shield 11 (in relation to the tank space T), the tank structure 10′ thus has in each case a substructure 16 and 18, respectively, of lightweight construction like the cooling shield 11. In particular, the tank structure 10′ in the present case shown in FIG. 1d comprises three corrugated plate cores, of which the middle one in the cross-section forms the cooling shield 11.

[0054] As an alternative to the corrugated shape, one or more of the material layers 14c, 15a, 17b could comprise sections angled with respect to one another, in particular be formed in jagged manner (not shown).

[0055] According to advantageous embodiments, one or more of the cavities Ha and/or one or more of the cavities Hi is/are connected to a vacuum pump, thereby forming an evacuable hollow volume in each case. As a result, a particularly good thermal insulation effect can be achieved.

[0056] Disclosed is a hydrogen tank 100 having a tank structure 10 which at least partially delimits a tank space T and comprises a cooling shield 11 designed in lightweight construction. A conduit system 21, connected to the tank space T, of a pressure relief system 20 for discharging gaseous hydrogen Wg from the tank space T is formed in the cooling shield 11. At least one para-ortho catalyst for accelerated conversion of parahydrogen into orthohydrogen is arranged in the conduit system.

[0057] Also disclosed are a vehicle with a hydrogen drive and such a hydrogen tank 100 and a method for cooling the tank structure of such a hydrogen tank.

[0058] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE LIST

[0059] 10 tank structure [0060] 11 cooling shield [0061] 12 tank wall [0062] 13a, 13b tank dome [0063] 14a, 14b, 14c material layer [0064] 15a, 15b material layer [0065] 16 substructure on the side of the cooling shield 11 facing the tank space T [0066] 17a, 17b material layer [0067] 18 substructure on the side of the cooling shield 11 facing away from the tank space T [0068] 20 pressure relief system [0069] 21 conduit system [0070] 22 inlet [0071] 23 outlet [0072] 100 hydrogen tank [0073] Φ heat flow [0074] H.sub.i, H.sub.a cavity [0075] W.sub.f liquid hydrogen [0076] W.sub.g gaseous hydrogen [0077] T tank space [0078] X central axis [0079] Z interspace [0080] Z.sub.i inner interspace