Tank for pressurized gas

Abstract

Pressurized Gas Reservoir The invention relates to a pressurized gas reservoir, such as for hydrogen, comprising a hollow structure including a cylindrical body about an axis, terminated at each end by a hemispherical cap about the axis, one cap having an orifice, a sealing casing (3) adapted to conform to the internal shape of the structure, a base (4), disposed in the orifice, having a substantially revolution-shaped form about the axis, comprising a first cylindrical portion (41) passing through the orifice and a second discoidal portion (42) disposed inside the structure and in contact with the casing (3), and an annular seal (5) disposed at the periphery (43) of the second portion (42). Figure for the abbreviation: Figure 4

Description

Title of the invention: Reservoir for pressurized gas

[0001] The invention relates to a tank for gases under high pressure, such as hydrogen.

[0002] The tank according to the invention is of the type comprising a hollow structure including a cylindrical body, along an axis A, terminated at each end by a hemi-ellipsoidal cap.

[0003] At least one of the two caps is pierced, substantially in its center, by an orifice. A sealing envelope or liner, generally made of polymer, conforms to the internal shape of the structure.

[0004] For each orifice, a base, allowing for filling and / or drawing, is disposed within the orifice. This base has a substantially circular shape about axis A. It comprises a first substantially cylindrical portion passing through the orifice and a second substantially discoidal portion disposed within the structure and integral with the casing. A base is, in a known manner, made of a metal alloy, conventionally by machining.

[0005] It is known to produce the composite structure, with a reinforcement of glass or carbon fibers embedded in a plastic matrix, by filament winding around an assembly comprising the base(s) associated with the sealing casing. Filament winding consists of winding a filament comprising a fiber reinforcement immersed in the plastic material in its soft phase around a mold form, here the sealing casing and the base(s). After winding, the result is treated so that the plastic material hardens, giving the structure its rigidity and strength.

[0006] Due to the stresses experienced by the base, the periphery of the discoidal portion cannot have a very fine profile capable of conforming to the profile of the sealing casing. Therefore, a step appears at the boundary between the periphery of the discoidal portion of the base and the sealing casing. This step is detrimental because it potentially risks catching the filament, which could then slip between the casing and the base or at least end up in an incorrect position. This adversely alters the otherwise uniform distribution of the filament, potentially causing a crack to initiate in the tank structure, which could lead to rupture when the tank is subjected to a pressure increase.

[0007] Also, a means of perfecting the interface between the periphery of the discoidal part of the base and the sealing envelope is sought.

[0008] To this end, the invention relates to a reservoir for high-pressure gases, such as hydrogen, comprising a hollow structure including a substantially cylindrical about an axis, terminated at each end by a cap substantially hemi-ellipsoidal about the axis, at least one of the two caps being pierced, substantially in its center, by an orifice, a sealing envelope adapted to conform to the internal shape of the structure, and for each orifice a base, disposed in the orifice, having a shape substantially of revolution around the axis, comprising a first substantially cylindrical part passing through the orifice and a second substantially discoidal part disposed inside the structure and in contact with the envelope, and also an annular seal disposed at the periphery of the second part of the base.

[0009] Specific features or embodiments, usable alone or in combination, are:

[0010] - the joint has a wing-shaped cross-section, comprising a thick part towards the inside and a tapered section towards the outside,

[0011] - the refined part is shaped to cover the envelope and ensure continuity between the base and the casing,

[0012] - the thick part includes a protuberance extending substantially radial and centripetal,

[0013] - the protuberance has a substantially circular cross-section, substantially Trapezoidal or roughly rectangular,

[0014] - the protuberance is centered relative to the thick part,

[0015] - the protuberance is eccentric relative to the thick part,

[0016] - the periphery includes a groove having a complementary cross-section of the section of the protuberance, in order to be suitable for accommodating the protuberance,

[0017] - the protrusion has a thickness between 0.3 and 1 times the thickness of the wing, and preferably between 0.4 and 0.7 times the wing thickness,

[0018] - the protrusion has a length between 0.3 and 2 times its thickness and preferably between 0.9 and 1.7 times its thickness,

[0019] - the ratio between the thickness of the thick part and the thickness of the thinned part is between 5 and 20, and preferably between 6 and 14.

[0020] - the wing length is between 3 and 30 mm and preferably between 9 and 14 mm,

[0021] - the thick part has an inner diameter slightly smaller than the diameter of the back of the throat,

[0022] - the ratio between the inner diameter of the thick part and the diameter of the bottom of the throat is between 90 and 100%, preferably between 95 and 98%.

[0023] According to another aspect, a method for manufacturing such a tank, comprising the following steps:

[0024] - installation of a seal at the periphery of a base, preferably by insertion, preferably by clipping,

[0025] - securing the sealing envelope to the base,

[0026] - realization of the structure by filament winding.

[0027] The invention will be better understood upon reading the following description, given solely by way of example, and with reference to the figures in the appendix in which:

[0028] [Fig-1] shows, in profile view, a tank,

[0029] [Fig.2] shows, in perspective view, a base equipped with a seal,

[0030] [Fig.3] shows, in cross-section, a detail of the whole of [Fig.2],

[0031] [Fig.4] shows, in perspective view, a base + seal + casing assembly,

[0032] [Fig.5] shows, in cross-section, a detail of the whole of [Fig.4],

[0033] [Fig.6] shows, in cross-section, a joint,

[0034] [Fig.7] shows, in profile view, a base,

[0035] [Fig.8] shows, in profile view, the detail of a throat. Description of the implementation methods

[0036] With reference to [Fig. 1], the invention relates to a reservoir 1 for gases under high pressure, such as hydrogen. This reservoir 1 comprises a hollow structure 2 including a body 21 substantially cylindrical about an axis A, terminated at each end by a cap 22 substantially hemi-ellipsoidal about the axis A, at least one of the two caps 22 being pierced, substantially in its center, by an orifice 23.

[0037] The tank 1 further includes a sealing envelope 3 adapted to conform to the internal shape of the structure 2.

[0038] The reservoir 1 further comprises, for each orifice 23, a base 4. Said base 4 is disposed in an orifice 23. A base 4 has a substantially revolution shape about the axis A. A base 4 comprises a first substantially cylindrical part 41, making the passage through the orifice 23, and a second substantially discoidal part 42, disposed inside the structure 2.

[0039] The second part 42 has an internal face, substantially flat, turned towards the inside of the reservoir 1 and in contact with the casing 3.

[0040] The second part 42 has an external face, substantially hemi-ellipsoidal, facing outwards from the reservoir 1, tangent to the structure 2 in its hemi-ellipsoidal cap portion 22. It follows that the periphery 43 of the second part 42, which has a substantially circular shape, forms a triple contact zone between structure 2, shell 3 and base 4.

[0041] Due to the stresses experienced by the base 4, the profile of said periphery 43 of the base 4 cannot have the tapered shape that would allow the base 4 to come gently tangent the envelope 3. A step then appears at the level of this periphery 43.

[0042] This denture is detrimental, in that, during the manufacture of structure 2 by filament winding, the filament may become caught in said denture, at the risk of causing a critical weakness of structure 2 and therefore of reservoir 1.

[0043] Also, according to one feature, the reservoir 1 further includes an annular seal 5. This seal 5 is located at the periphery 43 of the second part 42 of the base 4.

[0044] The objective of this joint 5 is to occupy the triple contact area located between the base 4, the envelope 3 and the structure 2.

[0045] According to another feature, the joint 5 has a wing-shaped section, comprising a thick part 51 towards the inside, i.e. on the side of axis A, and a thin part 52 towards the outside, i.e. on the side opposite axis A.

[0046] The refined part 52, whose radial section decreases with the radius, in that it gradually becomes tangent to the envelope 3, makes it possible to ensure a smooth interface between the base 4 and the envelope 3. Thus, the refined part 52 is shaped to cover the envelope 3 and ensure continuity between the base 4 and the envelope 3.

[0047] The thick part 51 has a section shaped to interface with the section of the periphery 43 of the base 4.

[0048] As more particularly illustrated in [Fig.6], according to another feature, the thick part 51 includes a protuberance 54. This protuberance 54 extends mainly in a substantially radial and centripetal manner, relative to the axis A.

[0049] Although it may have any cross-section, according to another characteristic, the protuberance 54 has a substantially circular, substantially trapezoidal or substantially rectangular cross-section.

[0050] According to another feature, the protuberance 54 is centered relative to the wing profile and the thick part 51.

[0051] According to another alternative feature, the protuberance 54 is eccentric relative to the wing profile and the thick part 51. This eccentricity can be inwards or outwards.

[0052] In order to accommodate the seal 5, according to another feature, the periphery 43 includes a groove 44. This groove 44 has a cross-section complementary to the cross-section of the protrusion 54. Thus, the periphery 43 is suitable for accommodating the protrusion 54 of the thick portion 51. Said protrusion 54 acts as a centering device, helping to position and maintain the seal 5 axially in place in the groove 44.

[0053] In what follows, a thickness is measured axially, parallel to axis A and a length is measured radially.

[0054] According to another feature, the protrusion 54 has a thickness e between 0.3 and 1 times the thickness E of the wing, i.e., the thickness E of the profile of the joint 5 taken axially. This thickness e is preferably between 0.4 and 0.7 times the thickness E of the wing.

[0055] Thus, by way of illustration, according to one embodiment, a protuberance 54 has a thickness e of 2 mm, for a thick part 51 having a thickness E of 3.18 mm, i.e. a ratio of 0.63.

[0056] According to another feature, the protrusion 54 has a length 1 between 0.3 and 2 times the thickness e of the protrusion 54. This length 1 is preferably between 0.9 and 1.7 times said thickness e.

[0057] Thus, by way of illustration, according to one embodiment, a protuberance 54 has a thickness e of 2 mm, for a length 1 of 3 mm, i.e. a ratio of 1.5.

[0058] According to another feature, the ratio between the thickness of the thick part 51 and the thickness of the thinned part 52 is between 5 and 20 and preferably between 6 and 14.

[0059] This is understood to mean average or maximum thicknesses. Thus, by way of illustration, according to one embodiment, the joint 5 has an average thickness E of the thick part 51 of 7 mm, for an average thickness of the thin part 52 of 0.5 mm, i.e. a ratio of 14.

[0060] According to another feature, the wing length L, i.e. the radial length L of the joint 5 section, is between 3 and 30 mm and preferably between 9 and 14 mm.

[0061] According to another feature, the thick part 51 has an inner diameter slightly smaller than the diameter of the bottom of the throat 44.

[0062] The seal 5 is advantageously made of an elastomeric material, such as EPDM. This material advantageously has a hardness of at least 70 Shore A.

[0063] Also, the seal 5 has the capacity to deform, in whole or in part, preferably elastically. Therefore, a slightly smaller diameter, by a few percent, allows for a seal 5 that must be temporarily stretched to exceed the largest diameter of the groove 44 and be inserted into the groove 44. Once in place in the groove 44, the seal 5 attempts to return to its initial size and shrinks. This ensures that the seal 5 clips into the groove 44, and even, if necessary, provides sustained clamping of the seal 5 against the bottom of the groove 44. This clipping, with possible clamping, ensures reinforced retention of the seal 5 in the groove 44.

[0064] According to another feature, the ratio between the inner diameter of the thick part 51 and the diameter of the bottom of the groove 44 is between 90 and 100%. This ratio is preferably between 95 and 98%.

[0065] According to another aspect, a method for manufacturing a reservoir 1 as described above, comprising the following steps. In a first step, a seal 5 is placed on the periphery 43 of a base 4. This placement is preferably achieved by insertion. This placement is also preferably achieved by clipping. In a second step, the sealing sleeve 3 is attached to the base 4. This forms a sleeve + base + seal assembly, which can serve as a mold form for the next step. Advantageously, thanks to the seal 5 which ensures a smooth joint between the base 4 and the sleeve 3, the step of the prior art no longer appears between the base 4 and the sleeve 3. In a third step, the structure 2 can be produced by filament winding.

[0066] The invention has been illustrated and described in detail in the drawings and the preceding description. This description is to be considered illustrative and given by way of example and not as limiting the invention to this single description. Numerous embodiments are possible. List of reference signs

[0067] 1: reservoir,

[0068] 2: structure,

[0069] 21: cylindrical body,

[0070] 22: hemisellipsoidal cap,

[0071] 23: orifice,

[0072] 3: sealing casing,

[0073] 4: base,

[0074] 41: first part: cylindrical portion,

[0075] 42: second part: discoidal portion,

[0076] 43: periphery,

[0077] 44: groove,

[0078] 5: annular seal,

[0079] 51: thick portion,

[0080] 52: tapered portion,

[0081] 54: protrusion,

[0082] A: axis,

[0083] e: thickness of the protrusion,

[0084] E: thickness of the wing,

[0085] 1: length of the protuberance,

[0086] L: length of the wing.

Claims

Demands

1. A reservoir (1) for gases under high pressure, such as hydrogen, comprising a hollow structure (2) including a body (21) substantially cylindrical about an axis (A), terminated at each end by a cap (22) substantially hemisellipsoidal about the axis (A), at least one of the two caps (22) being pierced, substantially in its center, by an orifice (23), a sealing casing (3) adapted to conform to the internal shape of the structure (2), and for each orifice (23) a base (4), disposed in the orifice (23), having a shape substantially of revolution about the axis (A), comprising a first portion (41) substantially cylindrical passing through the orifice (23) and a second portion (42) substantially discoidal disposed inside the structure (2) and in contact with the casing (3), characterized in that it further comprises an annular seal (5) disposed at the periphery (43) of the second portion (42) of the base (4).

2. Reservoir (1) according to claim 1, wherein the seal (5) has a wing-shaped section, comprising a thick portion (51) towards the inside and a tapered portion (52) towards the outside.

3. Reservoir (1) according to claim 2, wherein the tapered portion (52) is shaped to cover the casing (3) and ensure continuity between the base (4) and the casing (3).

4. Reservoir (1) according to any one of claims 2 or 3, wherein the thick portion (51) comprises a protrusion (54) extending substantially radially and centripetally.

5. Reservoir (1) according to claim 4, wherein the protrusion (54) has a substantially circular, substantially trapezoidal or substantially rectangular cross-section.

6. Reservoir (1) according to any one of claims 4 or 5, wherein the protrusion (54) is centered relative to the thick part (51).

7. Reservoir (1) according to any one of claims 4 or 5, wherein the protrusion (54) is eccentric relative to the thick part (51).

8. Reservoir (1) according to any one of claims 4 to 7, wherein the periphery (43) comprises a groove (44) having a cross-section complementary to the cross-section of the protrusion (54), in order to be able to accommodate the protrusion (54).

9. Tank (1) according to any one of claims 4 to 8, wherein the protrusion (54) has a thickness (e) between 0.3 and 1 times the thickness (E) of the wing and preferably between 0.4 and 0.7 times the thickness (E) of the wing.

10. Reservoir (1) according to any one of claims 4 to 9, wherein the protrusion (54) has a length (1) between 0.3 and 2 times its thickness (e) and preferably between 0.9 and 1.7 times its thickness (e).

11. Reservoir (1) according to any one of claims 2 to 10, wherein the ratio between the thickness (E) of the thick part (51) and the thickness of the thinned part (52) is between 5 and 20 and preferably between 6 and 14.

12. Tank (1) according to any one of claims 2 to 11, wherein the length (L) of the wing is between 3 and 30 mm and preferably between 9 and 14 mm.

13. Reservoir (1) according to any one of claims 8 to 12, wherein the thick part (51) has an inner diameter slightly smaller than the diameter of the bottom of the throat (44).

14. Reservoir (1) according to any one of claims 8 to 13, wherein the ratio between the inner diameter of the thick part (51) and the diameter of the bottom of the throat (44) is between 90 and 100%, preferably between 95 and 98%.

15. Method of manufacturing a tank (1) according to any one of the preceding claims, comprising the following steps: - placing a seal (5) on the periphery (43) of a base (4), preferably by insertion, more preferably by clipping, - securing the sealing envelope (3) with the base (4), - making the structure (2) by filament winding.

Images