Hydrogen storage tank comprising a plurality of seals

Abstract

A hydrogen storage tank includes a shell of longitudinal axis, a hydrogen supply and collection duct, and a stack of a plurality of divider elements. Each divider element forms a bottom accepting a hydrogen storage material. The largest transverse dimension of the divider elements is less than the largest transverse dimension of the internal volume of the shell, and the tank includes a plurality of seals in the space formed between the divider element and the shell as a result of the difference in largest transverse dimension.

Claims

1. A container for the storage of hydrogen by absorption of the hydrogen in a hydrogen-storage material, comprising: a shell with a longitudinal axis closed at both longitudinal ends; a hydrogen supply and collection pipe extending along the longitudinal axis, comprising a plurality of hydrogen-passage orifices; a stack of a plurality of separation elements along the longitudinal axis, each separation element comprising a passage for mounting the separation element around the pipe, and each separation element forming a base substantially perpendicular to the longitudinal axis receiving a hydrogen-storage material so as to form a plurality of beds of hydrogen-storage material, wherein the largest transverse dimension of the separation elements is less than the largest transverse dimension of the internal volume of the shell in which the pipe, the separation elements and the hydrogen-storage materials are situated, wherein the container comprises a plurality of seals, each seal being associated with a separation element, each seal extending over the entire periphery of the corresponding separation element and in contact with the shell, in the space formed between the separation element and the shell because of the difference in the largest transverse dimension, wherein each seal comprises a main portion extending longitudinally in contact with the longitudinal edge of the separation element, and wherein each seal further comprises a first portion and a second portion extending transversely towards the pipe on either side of the corresponding separation element from the main portion of the seal.

2. The container according to claim 1, wherein each seal is secured to the corresponding separation element.

3. The container according to claim 1, wherein each seal comprises a third portion forming a lip extending transversely towards the shell from the main portion of the seal in contact with the shell.

4. The container according to claim 3, wherein the third portion of the seal extends transversely towards the shell from the main portion of the seal transversely in line with the first portion and/or the second portion.

5. The container according to claim 3, wherein the third portion of the seal extends transversely towards the shell from the main portion of the seal halfway between the first and second portions.

6. The container according to claim 3, wherein each seal comprises a third portion forming a lip and a fourth portion forming a lip each extending transversely towards the shell from the main portion of the seal in contact with the shell, the third portion extending transversely in line with the first portion and the fourth portion extending transversely in line with the second portion.

7. The container according to claim 1, wherein each separation element is in the form of a disc, and wherein each seal is in the form of a ring disposed around the associated disc.

8. The container according to claim 3, wherein the largest transverse dimension of each seal is larger than the largest transverse dimension of the internal volume of the shell.

9. The container according to claim 1, wherein the distance between two successive separation elements along the longitudinal axis is less than the largest transverse dimension of the internal volume of the shell.

10. The container according to claim 1, wherein the hydrogen supply and collection pipe comprises at least one hydrogen-passage orifice at each stage of the container formed between two successive separation elements.

11. The container according to claim 1, wherein the hydrogen supply and collection pipe comprises a plurality of filters disposed against the pipe, each filter being facing at least hydrogen-passage orifice, the pipe comprising at least one filter disposed against at least one hydrogen-passage orifice formed on the pipe at each stage of the container formed between two successive separation elements.

12. The container according to claim 11, wherein each filter is held against the pipe by clamping means.

13. The container according to claim 1, wherein the hydrogen-storage material comprises hydrides.

14. A method for manufacturing a hydrogen storage container according to claim 1, comprising: placing of hydrogen-storage material in the bottom of the shell of the container; and placing of hydrogen-storage material on each separation element, wherein the assembly formed by the hydrogen supply and collection pipe, the separation elements and the seals are mounted prior to the placing of the hydrogen-storage material, and wherein each separation element is introduced into the shell at the end of the placing of hydrogen-storage material on the separation element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention can be best understood from a reading of the following detailed description of non-limitative example embodiments thereof, as well as from an examination of the schematic and partial figures of the accompanying drawing, on which:

(2) FIG. 1 is a schematic view in cross section of an example embodiment of a hydrogen-storage container according to the invention,

(3) FIG. 2 is a schematic perspective view showing in isolation the hydrogen supply and connection pipe of the hydrogen-storage container in FIG. 1,

(4) FIG. 3 is an enlarged view of part of FIG. 1 showing a detail of the design of the hydrogen-storage container in FIG. 1,

(5) FIG. 4 is a schematic view in cross section of a seal used in the hydrogen-storage container in FIG. 1, and

(6) FIGS. 5 and 6 are schematic views in cross section showing variant embodiments of the seal in FIG. 4.

(7) In all these figures, identical references can designate identical or similar elements.

(8) In addition, the various parts shown in the figures are not necessarily shown to a uniform scale, in order to make the figures more legible.

DETAILED DISCLOSURE OF PARTICULAR EMBODIMENTS

(9) It is stated that, in the following description of particular example embodiments of the invention, the hydrogen-storage material is hydrides, in particular metallic hydrides. In addition, the hydrogen-storage container described has a cylindrical shape of revolution. Nevertheless, any container formed by a hollow element having a longitudinal dimension greater than its transverse direction, and having any cross section, for example circular or polygonal or ellipsoidal, does not depart from the scope of the present invention.

(10) It should also be noted that, in the example embodiments described below, the filters 11 used are felts made from polymer material and the clamping collars 12 are of the Colson type. Naturally, these choices are in no way limitative.

(11) With reference to FIGS. 1 to 3, these show an example embodiment of a container 1 for the storage of hydrogen by absorption of the hydrogen in a hydrogen-storage material 2.

(12) In FIG. 1, this example of a storage container 1 can be seen, shown schematically.

(13) The container 1 comprises a shell, or barrel 3, with a longitudinal axis X, closed off at a bottom end by a bottom base 14. The container 1 also comprises a top wall 15 provided with an O-ring seal 16 closing the top end of the barrel 3.

(14) The container 1 is intended to be generally oriented so that the longitudinal axis X is substantially aligned with the direction of the gravity vector. However, during use thereof, for example in the case of a use on board, its orientation may change.

(15) The container 1 comprises hydrogen supply and collection means comprising in particular a hydrogen supply and collection pipe 4 extending along the longitudinal axis X from the bottom base 14 towards the top wall 15.

(16) The pipe 4 is for example connected to a hydrogen supply and collection circuit, for example at one of the longitudinal ends thereof.

(17) As will be explained below, the inside of the container 1 is divided into a plurality of stages along the longitudinal axis X and each stage comprises storage material 2. These stages are produced so that they prevent the passage of the storage material, in particular in the form of hydride powder, from one stage to another, thus preventing the accumulation of powder in one stage, in particular in the lower stages, and the appearance of pressure stresses on the internal wall of the barrel 3.

(18) Thus the container 1 comprises a stack of a plurality of separation elements 5 along the longitudinal axis X, regularly spaced apart from each other along the hydrogen supply and collection pipe 4. These separation elements 5 are mounted on the pipe 4 sealingly, for example by brazing, welding, adhesive bonding or force-fitting, or be formed in a single piece with the pipe 4. In addition, these separation elements 5 are here in the form of a discs 5.

(19) Each disc 5 comprises a passage 6, or central orifice, which enables the disc 5 to be mounted around the pipe 4. In addition, each disc 5 defines a base perpendicular to the longitudinal axis X on which hydride powder is deposited when the container 1 is manufactured in order to form a plurality of hydride-powder stages or beds.

(20) The discs 5 are mounted on the pipe 4 so that the longitudinal space EL between two successive discs 5 is less than the inside diameter Tv of the internal volume V of the barrel 3. Thus the thickness of the hydride powder beds can be controlled. In other words, the ratio EL/Tv is strictly less than 1.

(21) Moreover, as can be seen in FIG. 3, the diameter Td of the discs 5 is less than the inside diameter Tv of the barrel 3 so that a space E exists between each disc 5 and the barrel 3.

(22) Advantageously, the container 1 then comprises a plurality of seals 7 each associated with a disc 5, in the form of rings, and extending over the entire periphery of the corresponding disc 5. Each seal 7 is also situated in the space E formed between the corresponding disc 5 and the barrel 3.

(23) Each seal 7 is for example produced from rubber, for example fluorocarbon rubber (FKM), also known as Viton®.

(24) Advantageously, each seal 7 is secured to the disc 5 with which it is associated. As can be seen in FIGS. 3 and 4, each seal 7 comprises a main portion 8 extending longitudinally in contact with the longitudinal edge 9 of the disc 5. In addition, the seal 7 comprises a first portion 7a and a second portion 7b extending transversely towards the pipe 4 on either side of the disc 5 from the main portion 8.

(25) In the example in FIGS. 3 and 4, the seal 7 comprises a third portion 7c forming a lip extending transversely towards the barrel 3 from the main portion 8 of the seal 7 in contact with the barrel 3, the transverse extent of this third portion 7c lying transversely in line with the first portion 7a.

(26) On the other hand, in the example in FIG. 6, which is a variant embodiment of FIG. 4, the third portion 7c of the seal 7 extends transversely towards the barrel 3 from the main portion 8 halfway between the first 7a and second 7b portions. In this way, it is possible to form a seal 7 of the so-called central lip type having the advantage of better equilibrium with respect to the disc 5 on which it is installed.

(27) In another variant of FIGS. 4 and 6, the example embodiment in FIG. 5 shows that the seal 7 comprises a third portion 7c forming a lip and a fourth portion 7d forming a lip each extending transversely towards the barrel 3 from the main portion 8 in contact with the barrel 3, the third portion 7c extending transversely in line with the first portion 7a and the fourth portion 7d extending transversely in line with the second portion 7b. Then it is possible to form a so-called double lip seal 7 also having the advantage of better equilibrium with respect to the discs 5 on which it is installed, as well as a better seal since there is then a double barrier to be passed.

(28) Preferentially, as can be seen in FIG. 4, the ratio L/t between the length L of a lip 7c or 7d to the thickness t of the lip is between 2 and 4. This is because a lower ratio L/t, that is to say strictly less than 2, would involve an excessively rigid seal 7 that might for example not to be able to adapt to any defect in circularity fairly frequently encountered in metal fabrication for this type of cylindrical barrel 3. In addition, a higher ratio L/t, that is to say strictly greater than 4, would involve having one or more lips with a lack of mechanical strength so that they would risk revealing zones of non-contact with the barrel 3.

(29) Moreover, it should be noted that the diameter Tj of each seal 7, visible in FIG. 4, is greater than the inside diameter Tv of the barrel 3. Thus, advantageously, the seal 7 is mounted so as to be prestressed in the barrel 3. More precisely, when the seal 7 is introduced into the barrel 3, the lip or lips 7c, 7d of the seal 7 curve towards the top of the container 1 and naturally apply a pressure against the internal wall of the barrel 3, which provides a good seal.

(30) Furthermore, as can be seen in FIG. 2, the pipe 4 advantageously comprises a plurality of orifices 10, or holes 10, for the passage of hydrogen, for example produced by piercing. More precisely, each stage of the container 1 comprises a plurality of orifices 10 at the pipe 4.

(31) The pipe 4 then advantageously comprises a filter 11 at each stage in order to cover the hydrogen-passage orifices 10.

(32) These filters 11 make it possible to prevent the hydride powder 2 being able to escape through the pipe 4. They may for example be produced from fabric or felt with a fine mesh, comprising for example a metallic and/or polymer material. In order to obtain a good seal, the filters in this form are wound more than one time around the pipe 4.

(33) Moreover, in order to afford good holding of the filters 11 on the pipe 4 once the winding has ended, clamping collars 12 may be used, as can be seen in FIG. 3, for example of the Colson type.

(34) Naturally the invention is not limited to the example embodiments that have just been described. Various modifications can be made thereto by a person skilled in the art.