Tank for pressurized gas

Abstract

Tank for pressurized gas The invention relates to a tank (1) for high-pressure gas, such as hydrogen, comprising a structure having a substantially revolution-shaped shape, hollow so as to form a receiving volume, pierced with an opening so as to be able to connect the receiving volume with the outside, a rigid boss (3) arranged in the opening, comprising a cannula (4) in which a pipe (5) passing through the structure is hollowed out and a flexible, gas-tight envelope (13), covering the inner surface of the structure so as to envelop the receiving volume and comprising a neck (14), assembled in a sealed manner with the boss (3) in continuity with the pipe (5), where the neck (14) is arranged around the external periphery of the cannula (4) and the boss (3) further comprises a deformable ring (9) pressing the neck (14) against the cannula (4) in an annular and centripetal manner. Figure for abstract: Figure 1

Description

Title of the invention: Tank for pressurized gas Technical field

[0001] The invention relates to a tank for pressurized gas. Prior art

[0002] It is known to produce a tank for pressurized gas, of the type comprising a structure having a substantially revolution-like shape, hollow so as to form a receiving volume, pierced with an opening so as to be able to connect the receiving volume with the outside, a rigid boss arranged in the opening, in which a through pipe is hollowed out and a flexible envelope comprising a neck, assembled in a sealed manner with the boss.

[0003] The invention proposes a particularly advantageous solution for achieving sealing between the neck of the casing and the boss. Summary of the invention

[0004] The invention proposes to provide a reservoir for high-pressure gas, such as hydrogen, comprising a structure having a substantially revolution-like shape, hollow so as to form a receiving volume, pierced with an opening so as to be able to connect the receiving volume with the outside, a rigid boss arranged in the opening, comprising a cannula in which a pipe passing through the structure is hollowed out and a flexible, gas-tight envelope, covering the inner surface of the structure so as to envelop the receiving volume and comprising a neck, assembled in a sealed manner with the boss in continuity with the pipe, where the neck is arranged around the external periphery of the cannula and in that the boss further comprises a deformable ring pressing the neck against the cannula in an annular and centripetal manner.

[0005] Particular characteristics or embodiments, usable alone or in combination, are:

[0006] - the ring has a conical shape, and the boss further comprises a first annular part surrounding the lower part of the neck and a second annular part surrounding the upper part of the neck, capable of being assembled with the rest of the boss by enclosing the ring between the two parts, so that the second part presses on the outer surface of the ring,

[0007] - the conicity of the ring is between 5° and 45°, preferably between 10° and 40° and preferably between 15° and 35°,

[0008] - the ring and the second part are shaped so that the ring penetrates the neck with a thickness between 20% and 50% of the neck thickness,

[0009] - the inner surface of the ring, in contact with the neck, comprises at least one annular tooth,

[0010] - the assembly of the second part is carried out with the first part at by means of at least one longitudinal screw or with the cannula by means of a longitudinal thread,

[0011] - the cannula is integral with the second part,

[0012] - the boss, including the ring, is made of metallic material,

[0013] - the casing, including the neck, is made of thermoplastic material of the polyamide type, polyolefin PE or PP, PAEK, PES, possibly loaded with a particulate or filamentary filler, with or without additives or in thermoplastic elastomer material PTE.

[0014] According to a second aspect of the invention, a method of manufacturing such a tank, comprising a step of heating the neck before pressing the neck by the ring

[0015] Particular characteristics or embodiments, usable alone or in combination, are: the heating temperature is lower than the melting point of the neck and preferably between 40° and 90° Brief description of the drawings

[0016] The invention will be better understood on reading the following description, given solely by way of example, and with reference to the appended figures in which:

[0017] [Fig.l] shows, in sectional profile view, a half-tank head, according to a first embodiment of the invention,

[0018] [Fig.2] shows, in sectional profile view, a half-tank head, according to another embodiment of the invention,

[0019] [Fig.3] shows, in cut profile view, a detail of the action of a ring,

[0020] [Fig.4] shows, in sectional profile view, another embodiment of a ring. Description of the embodiments

[0021] With reference to [Fig.l], the invention relates to a tank 1 for high-pressure gas. This gas can be any gas, including hydrogen.

[0022] The tank 1 comprises a structure, not shown, having a shape substantially of revolution around a longitudinal axis A. The tank 1 is not necessarily cylindrical. The invention applies to any tank 1 having an opening with a tubular neck. The structure is hollow so as to form a receiving volume for the gas. According to a conventional embodiment, the structure has a shape substantially cylindrical with axis A, terminated at each end of the cylinder, by a substantially hemispherical shell, of the same section as the cylinder. The structure is pierced with an opening so as to be able to connect the receiving volume with the exterior, and thus to be able to fill or draw gas from the tank 1. This opening is typically arranged in the center of a hemispherical shell, along the axis A. The structure can be made of composite with a fiber reinforcement / network, such as glass or carbon fibers, embedded in a thermoplastic or thermosetting resin matrix.

[0023] The reservoir 1 further comprises a rigid boss 3 arranged in the opening. The boss 3 comprises a cannula 4 in which a pipe 5 is dug, of axis A, passing through the structure, in order to allow filling and drawing, advantageously under the control of a valve.

[0024] The structure is not gas-tight. Also, the tank 1 further comprises a flexible, gas-tight envelope 13 or liner. This envelope 13 covers substantially the entire interior surface of the structure, so as to envelop the receiving volume. It comprises a neck 14, substantially cylindrical, of axis A. The neck 14 is conventionally made of a single material with the rest of the envelope 13 in order to create a sealed connection between the neck 14 and the rest of the envelope 13.

[0025] The neck 14 is assembled in a sealed manner with the boss 3, in continuity with the pipe 5. Thus, the interior of the hollow volume delimited by the structure and sealed by the casing 13 can be put in communication with the exterior of the tank 1 via the pipe 5.

[0026] For this, the neck 14 is arranged around the external periphery of the cannula 4 and the boss 3 further comprises a deformable ring 9 pressing annularly and centripetally the neck 14 against the cannula 4. As illustrated in [Fig.l] or 2, the neck 14 surrounds and encloses the external surface of the cannula 4, the internal surface of the neck 14 being in contact with the external surface of the cannula 4. The ring 9 surrounds and encloses, with significant pressure, the external surface of the neck 14. This has the effect of pressing, on an annular band located under the ring 9, the neck 14 against the cannula 4. The neck 14 being made of a deformable and at least partially elastic material, this annular pressure creates a gas seal between the neck 14 and the cannula 4, or between the casing 13 and boss 3.

[0027] According to another characteristic, the ring 9 has a conical shape and the boss 3 further comprises a first part 6 and a second part 7 capable of being assembled with the rest of the boss 3, in such a way that the second part 7 presses on the external surface 11 of the ring 9. The ring 9 has a conical shape. In other words, the external surface 11 and the internal surface 10 are shaped in a dihedral shape and have a conicity angle between them. Said conicity opens preferentially towards the inside of the tank 1.

[0028] For this, the first part 6 is annular and surrounds the lower part of the neck 14, i.e. the part of the neck 14 close to the rest of the envelope 13 and comprising the junction between the neck 14 and the rest of the envelope 13. The second part 7 is also annular and surrounds the upper part of the neck 14, i.e. the distal part of the neck 14 or the part where the neck 14 has an opening. The second part 7 is still able to be assembled with the rest of the boss 3. The first part 6 and the second part 7 enclose the ring 9 between them. Thus, the second part 7 presses on the outer surface 11 of the ring 9. This support is mainly exerted longitudinally, i.e. parallel to the axis A, due to a mutual approximation along the longitudinal axis A of the first part 6 and the second part 7. It is appropriate that the second part 7 approaches the first part 6, without the first part 6 detaching from the part 13.The force exerted longitudinally on the outer surface 11 of the ring 9 is transformed, due to the conicity of the ring 9, into a centripetal force comprising at least one radial component.

[0029] According to another characteristic, the conicity of the ring 9 is between 5° and 45°. Preferably this conicity is between 10° and 40°. Even more preferably this conicity is between 15° and 35°.

[0030] According to another characteristic, the ring 9 and the second part 7 are shaped so that the ring 9 penetrates into the neck 14 with a thickness of between 20% and 50% of the thickness e of the neck 14. Thus, the conicity of the ring 9 and the complementary shape of the second part 7 which comes into contact with the outer surface 11 of the ring 9 are shaped so that the inner surface 10 of the ring 9 penetrates into the thickness e of the neck 14 with a thickness of between 20% and 50%.

[0031] According to another characteristic, more particularly illustrated in Figures 3 and 4, in order to increase, at least locally, the pressure on the neck 14 and therefore the resulting seal, the inner surface 10 of the ring 9 comprises at least one annular tooth 12. This at least one annular tooth 12 creates at least one narrow annular band of increased pressure and therefore seal. The inner surface 10 of the ring 9 is the surface 10 of the ring 9 which is in contact with the neck 14. The inner surface 10 can have any type of profile. It can have a convex profile, as illustrated in [Fig.3] or alternatively, as illustrated in [Fig.4], it can have a rectilinear profile.

[0032] According to another characteristic, more particularly illustrated in [Fig.l], the assembly of the second part 7 is carried out with the first part 6. This assembly can be carried out by any means ensuring a longitudinal approximation of the second part 7 relative to the first part 6. This can, for example, as illustrated in [Fig.l], be carried out by means of at least one longitudinal screw 8. In in this case, said at least one screw 8 ensures both the movement of the second part 7 relative to the first part 6 towards each other and therefore the support against the ring 9 and the creation of the centripetal force, and the assembly of the two parts 6, 7 together.

[0033] According to another alternative characteristic, more particularly illustrated in [Fig. 2], the assembly of the second part 7 is carried out with the cannula 4. This assembly can be carried out by any means ensuring a longitudinal approximation of the second part 7 relative to the cannula 4 towards each other and therefore the support against the ring 9 and the creation of the centripetal force. This can, for example, as illustrated in [Fig. 2], be carried out by means of a longitudinal thread 15, arranged between the second part 7 which can be threaded, respectively tapped, and the cannula 4 which can be tapped, respectively threaded.

[0034] According to another characteristic, the cannula 4 is integral with the second part 7.

[0035] Thus, the cannula 4, the first part 6, the second part 7 and the ring 9 form together boss 3.

[0036] The seal is normally entirely achieved by pressure, by the ring 9 of the neck 14 against the cannula 4.

[0037] According to another characteristic, the boss 3, including the ring 9, is made of metallic material. The boss 3 is typically made of light alloy. Advantageously, the ring 9 is made of a softer material than the material of the second part 7 in order to be sure that it is the ring 9 which deforms and not the second part 7.

[0038] It has been seen that the material of the neck 14 is flexible and at least partially elastic in order to be able to achieve sealing by compression. According to another characteristic, this is obtained with a production of the envelope 13, including the neck 14, in a thermoplastic material of the polyamide, polyolefin PE or PP, PAEK, PES type, possibly loaded with a particulate or filamentary filler, with or without additives or in thermoplastic elastomer material PTE.

[0039] Another sealing point is made between the second part 7 and the ring 9. This is a metal / metal seal.

[0040] The invention also relates to a method of manufacturing such a tank 1. In order to be able to increase the deformation at break of the material of the neck 14 and thus allow deformation during the pressing of the ring 9 with less risk of damage to the material of the neck 14, it is advantageous to heat the neck 14 before it is pressed by the ring 14. Also, the method of manufacturing such a tank 1 advantageously comprises a step of heating the neck 14 before the pressing of the neck 14 by the ring 9.

[0041] According to another characteristic, the heating temperature of the neck 14 is lower than the melting point of the neck 14. This heating temperature is preferably between 40° and 90° depending on the material used for the neck 14. This heating temperature should not be too high to avoid a fine relaxation of the material, which would lead, in a detrimental manner, to a loss of contact pressures.

[0042] The invention has been illustrated and described in detail in the drawings and the preceding description. This should be considered as illustrative and given by way of example and not as limiting the invention to this description alone. Numerous alternative embodiments are possible. List of reference signs

[0043] 1: reservoir,

[0044] 2: structure,

[0045] 3: bossage,

[0046] 4: cannula,

[0047] 5: pipeline,

[0048] 6: first part,

[0049] 7: second part,

[0050] 8: screw,

[0051] 9: ring,

[0052] 10: inner surface,

[0053] 11: outer surface,

[0054] 12: tooth,

[0055] 13: envelope,

[0056] 14: neck,

[0057] 15: thread,

Claims

Claims

1. Tank (1) for high-pressure gas, such as hydrogen, comprising a structure having a substantially revolution-shaped shape, hollow so as to form a receiving volume, pierced with an opening so as to be able to connect the receiving volume with the outside, a rigid boss (3) arranged in the opening, comprising a cannula (4) in which a pipe (5) passing through the structure is hollowed out and a flexible, gas-tight envelope (13), covering the inner surface of the structure so as to envelop the receiving volume and comprising a neck (14), assembled in a sealed manner with the boss (3) coaxially with the pipe (5), in which the neck (14) is arranged around the external periphery of the cannula (4) and in that the boss (3) further comprises a deformable ring (9) pressing the neck (14) in an annular and centripetal manner against the cannula (4), characterized in that the ring (9) has a conical shape,and in that the boss (3) further comprises a first annular part (6) surrounding the lower part of the neck (14) and a second annular part (7) surrounding the upper part of the neck (14), capable of being assembled with the rest of the boss (3) by enclosing the ring (9) between the two parts (6, 7), so that the second part (7) presses on the external surface (11) of the ring (9).,

2. Tank (1) according to claim 1, where the conicity of the ring (9) is between 5° and 45°, preferably between 10° and 40° and even more preferably between 15° and 35°.

3. Tank (1) according to any one of claims 1 or 2, wherein the ring (9) and the second part (7) are shaped so that the ring (9) penetrates into the neck (14) with a thickness of between 20% and 50% of the thickness (e) of the neck (14).

4. Tank (1) according to any one of claims 1 to 3, wherein the inner surface (10) of the ring (9), in contact with the neck (14), comprises at least one annular tooth (12).

5. Tank (1) according to any one of claims 2 to 4, wherein the assembly of the second part (7) is carried out with the first part (6) by means of at least one longitudinal screw (8) or with the cannula (4) by means of a longitudinal thread (15).

6.

7.

8.

9.

10. Reservoir (1) according to any one of claims 2 to 5, wherein the cannula (4) is integral with the second part (7). Tank (1) according to any one of claims 1 to 6, wherein the boss (3), including the ring (9), is made of metallic material. Tank (1) according to any one of claims 1 to 7, where the casing (13), including the neck (14), is made of thermoplastic material of the polyamide, polyolefin PE or PP, PAEK, PES type, possibly loaded with a particulate or filamentary filler, with or without additives or of thermoplastic elastomer material PTE. Method for manufacturing a tank (1) according to any one of the preceding claims comprising a step of heating the neck (14) before pressing the neck (14) by the ring (9). Method according to the preceding claim, where the heating temperature is lower than the melting point of the neck (14) and preferably between 40° and 90°.

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