TANK WITH INTERNAL AND EXTERNAL SPACES AND AT LEAST ONE PIPE PASSING THROUGH AT LEAST ONE DEFORMABLE CLOSURE PLATE

Description

[0001] The present application relates to a tank comprising internal and external enclosures as well as at least one conduit passing through at least one deformable closing plate.

[0002] US7344045 B2 discloses such a reservoir.

[0003] According to an embodiment visible on the figure 1 , a hydrogen tank 10 comprises an external enclosure 12, an internal enclosure 14 positioned in the external enclosure 12, thermal insulation between the external and internal enclosures 12, 14 and two diametrically opposed connecting systems 16, 16' connecting the external and internal enclosures 12, 14. In operation, due to the temperature and pressure of storage of the hydrogen in the cryogenic state, the internal enclosure 14 may, depending on the situation, contract or expand more than the external enclosure 12. Consequently, at least one of the two connecting systems 16' is configured to allow movement of the internal enclosure 14 relative to the external enclosure 12 in a direction of movement. According to one arrangement, the first connecting system 16 (the one on the left in the figure 1 ) is rigid and does not allow any relative movement between the external and internal enclosures 12, 14 while a second connection system 16' (the one on the right on the figure 1 ) allows relative movement between the external and internal enclosures 12, 14.

[0004] According to an embodiment visible on the figure 2 , the first connection system 16 comprises a tubular interface 18 passing through the external and internal enclosures 12, 14 and having a first end 18.1 opening outside the external tank 12 and a second end 18.2 opening inside the internal tank 14, each of the external and internal enclosures 12, 14 comprising a through hole 12.1, 14.1 to allow the passage of the tubular interface 18. The first connection system 16 comprises a first rigid connection 20 connecting the tubular interface 18 and the external enclosure 12 as well as a second rigid connection 20' connecting the tubular interface 18 and the internal enclosure 14. According to one configuration, one of the first and second connections 20, 20' comprises at least one flange comprising a first wing pressed against the external or internal enclosure 12, 14 and connected to the latter as well as a second wing pressed against the tubular interface 18 and connected to the latter.In addition, the first connection system 16 comprises a first closure plate 22.1 closing the first end 18.1 of the tubular interface 18 as well as a second closure plate 22.2 closing the second end 18.2 of the tubular interface 18.

[0005] The hydrogen tank 10 comprises several conduits 24, 24' which pass through the first and second closure plates 22.1, 22.2 and each comprise a first end 24.1, 24.1' opening into the internal enclosure 14. All these conduits 24, 24' are rectilinear between the first and second closure plates 22.1, 22.2.

[0006] Each of the first and second closure plates 22.1, 22.2 comprises, for each conduit 24, 24', an orifice 26 to allow the conduit 24, 24' to pass through it. At each orifice 26, each conduit 24, 24' is connected to the first or second closure plate 22.1, 22.2 by a weld bead 28 which connects the conduit 24, 24' to the first or second closure plate 22.1, 22.2 in a sealed manner around the entire perimeter of the conduit 24, 24'.

[0007] In one embodiment, the materials of the different elements (enclosures, conduits, closing plates, connection systems) may be different: for example metallic / composite.

[0008] In operation, taking into account: the pressure in the internal enclosure 14, the difference in thermal expansion between the materials of the conduits 24, 24' and of the connection system 16, the very significant temperature difference between on the one hand the external enclosure 12 and the first closing plate 22.1 and on the other hand the internal enclosure 14 and the second closing plate 22.2, the conduits 24, 24', the weld beads 28 as well as the internal and external enclosures are subjected to significant stresses which can damage them. STATEMENT OF THE INVENTION:

[0009] The present invention aims to remedy all or part of the aforementioned drawbacks.

[0010] For this purpose, the invention relates to a tank comprising an external enclosure, an internal enclosure positioned in the external enclosure, first and second connecting systems connecting the external and internal enclosures, a first wall connected to the external enclosure, a second wall connected to the internal enclosure and at least one conduit passing through the first and second walls. Each of the first and second walls comprises at least one connection zone connected to the internal or external enclosure and, for each conduit, an orifice crossed by the conduit as well as a connecting zone surrounding the orifice and comprising a connection connecting the conduit and the first or second wall.

[0011] According to the invention, at least one wall among the first and second walls comprises at least one deformable zone interposed between the connection zone and the linking zone, the deformable zone being configured to allow the linking zone to move relative to the connection zone.

[0012] The deformable zone makes it possible to compensate for a dimensional variation between the first and second walls and to limit the stresses on the connections in order to reduce the risk of damage to the latter.

[0013] According to another characteristic, each deformable zone describes a circle.

[0014] According to another characteristic, each deformable zone comprises at least one undulation describing a circle.

[0015] According to another characteristic, each deformable zone comprises several concentric undulations forming a bellows.

[0016] According to another characteristic, the wall has a first thickness outside the deformable zone(s) as well as a second thickness less than the first thickness in each deformable zone.

[0017] According to another characteristic, the wall comprises, for each connection zone, a deformable zone surrounding the connection zone.

[0018] According to another characteristic, the wall comprises a deformable zone surrounding several connecting zones.

[0019] According to another feature, the connection zone is in the form of a crown. In addition, the deformable zone and the connection zone are concentric, the deformable zone surrounding all the connection zones.

[0020] According to one configuration, the first connecting system comprises: a tubular interface passing through the external and internal enclosures, connected to the latter and having a first end opening outside the external enclosure and a second end opening inside the internal enclosure, a first closing plate closing the first end of the tubular interface and comprising at least one deformable zone, a second closing plate closing the second end of the tubular interface and comprising at least one deformable zone.

[0021] According to another characteristic, each conduit comprises an intermediate section located between the first and second walls and having an excess length between said first and second walls.

[0022] According to another characteristic, each intermediate section has an axis which follows a trajectory in the form of a circular helix.

[0023] According to another characteristic, the tank comprises several conduits passing through the first and second walls, the helix-shaped trajectories of the intermediate sections of the different sections having approximately the same helix axis.

[0024] The invention also relates to an aircraft comprising at least one tank according to one of the preceding characteristics.

[0025] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which: There figure 1 is a longitudinal section of a tank illustrating an embodiment of the prior art, The figure 2 is a longitudinal section of a connection system, connecting external and internal enclosures of the tank visible on the figure 1 , illustrating an embodiment of the prior art, The figure 3 is a longitudinal section of a connecting system, connecting external and internal enclosures of a tank, illustrating an embodiment of the invention, The figure 4 is a perspective view of a connecting system, connecting external and internal enclosures of a tank, illustrating an embodiment of the invention, The figure 5 is a sectional view of a closure plate illustrating one embodiment of the invention, The figure 6 is a section of part of the closing plate visible on the figure 5 illustrating a detail of the said plate, The figure 7 is a perspective view of a connection system, connecting external and internal enclosures of a tank, illustrating another embodiment of the invention.

[0026] According to an embodiment visible on the figures 3 , 4 And 7, a tank 30 comprises an external enclosure 32, an internal enclosure 34 positioned in the external enclosure 32 as well as two diametrically opposed connection systems 36, connecting the external and internal enclosures 32, 34. According to one configuration, the tank 30 may comprise thermal insulation between the external and internal enclosures 32, 34.

[0027] According to one arrangement, the first connecting system 36 is substantially rigid while the second connecting system (not shown) allows relative movement between the external and internal enclosures 32, 34. The second connecting system is configured to allow relative movement between the external and internal enclosures 32, 34, oriented in a longitudinal direction.

[0028] According to one application, at least one aircraft comprises at least one tank 30 used to store a fluid in a cryogenic state, such as hydrogen. Of course, the invention is not limited to this application.

[0029] The first connecting system 36 comprises a tubular interface 38 passing through the external and internal enclosures 32, 34, connected to the latter and having a first end 38.1 opening outside the external enclosure 32, as well as a second end 38.2 opening inside the internal enclosure 34, each of the external and internal enclosures 32, 34 comprising a through hole 32.1, 34.1 to allow the passage of the tubular interface 38. The tubular interface 38 has an axis of revolution A38 parallel to the longitudinal direction.

[0030] According to one configuration, the first connecting system 36 comprises, for the internal enclosure 34, two L-shaped flanges 40, 40' positioned on either side of the internal enclosure 34, each flange 40, 40' comprising a first wing 40.1, 40.1' pressed against the internal enclosure 34 and connected to the latter as well as a second wing 40.2, 40.2' pressed against the tubular interface 38 and connected to the latter. The first connecting system 36 also comprises, for the external enclosure 32, a flange 40 positioned outside the external enclosure 32, comprising a first wing 40.1 pressed against the external enclosure 32 and connected to the latter, as well as a second wing 40.2 pressed against the tubular interface 38 and connected to the latter. Of course, the invention is not limited to this configuration for the connections between the tubular interface 38 and the external and internal enclosures 32, 34.

[0031] The first connecting system 36 comprises a first closing plate 42.1 closing the first end 38.1 of the tubular interface 38 and a second closing plate 42.2 closing the second end 38.2 of the tubular interface 38. According to one configuration, the tubular interface 38 comprises a first collar 44.1 at its first end 38.1 and a second collar 44.2 at its second end 38.2, each of the first and second collars 44.1, 44.2 having a contact face F44.1, F44.2, positioned in a transverse plane perpendicular to the axis of revolution A38, against which the corresponding closing plate 42.1, 42.1 is pressed. Each of the first and second closure plates 42.1, 42.2 is in the form of a disc and comprises at least one connection zone 46 connected, directly or indirectly, to the external or internal enclosure 32, 34.At the connection zones 46, each closure plate 42.1, 42.2 is pressed against the contact face F44.1, F44.2 of the corresponding first or second collar 44.1, 44.2 and connected to the latter by connecting elements. The connection zones 46 of the first and second closure plates 42.1, 42.2 are rigid. According to one configuration, each connection zone 46 is in the form of a crown.

[0032] Each of the first and second closure plates 42.1, 42.2 comprises a first face F42.1, F42.2 configured to be pressed against the contact face F44.1, F44.2 of the corresponding first or second collar 44.1, 44.2 as well as a second face F42.1', F42.2' opposite the first face F42.1, F42.2. Each of the first and second closure plates 42.1, 42.2 has an axial direction DA substantially perpendicular to the first face F42.1, F42.2.

[0033] When attached to the tubular interface 38, the first and second closure plates 42.1, 42.2 are substantially parallel to each other and perpendicular to the longitudinal direction. For each of the first and second closure plates 42.1, 42.2, the axial direction DA is parallel to the longitudinal direction.

[0034] Of course, the invention is not limited to this embodiment for the tubular interface 38.

[0035] The tank 30 comprises at least one conduit 48 which passes through the first and second closure plates 42.1, 42.2 and has a first end 48.1 opening outside the external enclosure 32 as well as a second end 48.2 opening into the internal enclosure 34.

[0036] For each conduit 48, the first closure plate 42.1 comprises a first orifice 50.1 to allow the conduit 48 to pass through said first closure plate 42.1 as well as a first connection zone 52.1 which surrounds the first orifice 50.1 and comprises a first connection 54.1 connecting the conduit 48 and the first closure plate 42.1. At the first orifice 50.1, each conduit 48 has an axis of revolution A48 parallel to the axial direction DA.

[0037] For each conduit 48, the second closure plate 42.2 comprises a second orifice 50.2 to allow the conduit 48 to pass through said second closure plate 42.2 as well as a second connection zone 52.2 which surrounds the second orifice 50.2 and comprises a second connection 54.2 connecting the conduit 48 and the second closure plate 42.2. At the second orifice 50.2, each conduit 48 has an axis of revolution A48 parallel to the axial direction DA.

[0038] The first and second connections 54.1, 54.2 are rigid connections. Consequently, the first and second connection zones 52.1, 52.2 are substantially rigid. Each of the first and second connections 54.1, 54.2 is a sealed connection ensuring a fluid seal between the conduit 48 and the first or second closure plate 42.1, 42.2. By way of example, each of the first and second connections 54.1, 54.2 comprises at least one weld bead surrounding the conduit 48 and ensuring a sealed connection between the latter and the closure plate 42.1, 42.2. Of course, the invention is not limited to this embodiment for the first and second rigid connections 54.1, 54.2. By way of example, the first or second connection 54.1, 54.2 could be in the form of a flange.

[0039] According to one feature, at least one wall 56 among the first and second closure plates 42.1, 42.2 comprises at least one deformable zone 58 interposed between the connection zone 46 and the first or second connection zone 52.1, 52.2 and configured to allow the first or second connection zone 52.1, 52.2 to move relative to the connection zone 46 in the axial direction DA. According to one configuration, the deformable zone 58 is configured to deform elastically. Outside the deformable zones 58, each of the first and second faces F42.1, F42.2, F44.1', F44.2' of the first and second closing plates 42.1, 42.2 is located in a transverse plane perpendicular to the axial direction DA while in each deformable zone, it is offset in the axial direction relative to this transverse plane.

[0040] According to one arrangement, the wall 56 comprises, for each connecting zone 52.1, 52.2, a deformable zone 58 surrounding the connecting zone 52.1, 52.2.

[0041] According to another arrangement visible on the figures 3 à 7 , the wall 56 comprises a deformable zone 58 surrounding several connecting zones 52.1, 52.2.

[0042] According to one embodiment, each deformable zone 58 describes a circle. According to one configuration, the deformable zone 58 and the connection zone 46 are concentric and the deformable zone 58 surrounds all the connection zones 52.1, 52.2.

[0043] According to one embodiment, the deformable zone 58 comprises at least one undulation which describes a circle. According to one arrangement, the deformable zone 58 comprises several concentric undulations forming a bellows.

[0044] According to an embodiment visible on the figure 6 , the wall 56 has a first thickness outside the deformable zone(s) 58 as well as a second thickness less than the first thickness in each deformable zone 58.

[0045] According to one arrangement, only one wall 56 among the first and second closing plates 42.1, 42.2 comprises at least one deformable zone 58.

[0046] According to another arrangement, each of the first and second closure plates 42.1, 42.2 comprises at least one deformable zone 58.

[0047] According to one method of operation, the first and second closing plates 42.1, 42.2 are obtained by stamping.

[0048] In operation, the outer enclosure 34 and the first closure plate 42.1 are in contact with an environment at room temperature while the inner enclosure 34, the second closure plate 42.2 and the section of the conduit 48 located in the inner enclosure 34 are in contact with a fluid at a cryogenic temperature, significantly lower than the room temperature. This temperature difference causes a deformation of at least one element, among the outer and inner enclosures 32, 34, the conduit 48 and the first and second closure plates 42.1, 42.2, which tends to modify the spacing between the first and second closure plates 42.1, 42.2 at the first and second orifices 50.1, 50.2. Because at least one of the closure plates 42.1, 42.2 comprises at least one deformable zone 58, the connecting zone 52.1, 52.2 surrounding each conduit 48 can move in the axial direction DA relative to the tubular interface 38 and compensate for the dimensional variation between the first and second closure plates 42.1, 42.2, which makes it possible to limit the stresses on the first and second connections 54.1, 54.2 and to reduce the risks of damage to said first and second connections 54.1, 54.2.

[0049] On the other hand, this temperature difference causes different deformations of the tubular interface 38 and of at least one of the first and second closure plates 42.1, 42.2. The differences in deformation are all the more significant when the materials of the tubular interface and the closure plates are different, for example when the tubular interface 38 is made of a composite material and the closure plates are metallic. The fact that a closure plate 42.1, 42.2 comprises at least one deformable zone 58 allows radial deformations of said closure plate, which makes it possible to compensate for the differences in deformation between this closure plate and the tubular interface.

[0050] According to one embodiment, the tank 30 comprises several conduits 48, 48', 48" which pass through the first and second closing plates 42.1, 42.2.

[0051] According to an embodiment visible on the figures 2 à 6 , each 48, 48', 48" conduit is straight

[0052] According to another embodiment visible on the figure 7 , each conduit 48, 48', 48" comprises an intermediate section 60 located between the first and second closure plates 42.1, 42.2. For at least one of the conduits 48, 48', 48", the intermediate section 60 has a curved axis A48 and an excess length between said first and second closure plates 42.1, 42.2. This excess length of the intermediate section 60 of the conduit 48 makes it possible to compensate for the dimensional variation between the first and second closure plates 42.1, 42.2, to limit the stresses on the first and second connections 54.1, 54.2 and to reduce the risks of damage to said first and second connections 54.1, 54.2.

[0053] According to one configuration, the axis A48 of the intermediate section 60 follows a trajectory in the form of a circular helix at least between the first and second closure plates 42.1, 42.2. According to one arrangement, the first and second closure plates 42.1, 42.2 are substantially parallel to each other and angularly offset by approximately 180°. Consequently, if the first orifice 50.1 of the first closure plate 42.1 crossed by a conduit 48 is located at 6 o'clock then the second orifice 50.2 of the second closure plate 42.1 crossed by the same conduit 48 is located at 12 o'clock.

[0054] In the presence of several conduits 48, 48', 48" passing through the first and second closure plates 42.1, 42.2, each of them comprises an intermediate section 60, 60', 60" which has a curved axis A48, A48', A48". All the intermediate sections 60, 60', 60" follow trajectories in the form of a circular helix having approximately the same helix axis, at least between the first and second closure plates 42.1, 42.2.

[0055] Of course, the invention is not limited to the embodiments previously described. The first and second closure plates 42.1, 42.2 could be positioned in line with the walls of the external and internal enclosures 32, 34 respectively. Whatever the embodiment, the tank 30 comprises a first wall 42.1 connected to the external enclosure 32 at at least one connection zone 46, a second wall 42.2 connected to the internal enclosure 34 at at least one connection zone 46 as well as at least one conduit 48 passing through the first and second walls 42.1, 42.2. For each conduit 48, the first and second walls 42.1, 42.2 respectively comprise first and second orifices 50.1, 50.2 to allow the conduit 48 to pass through the first and second walls 42.1, 42.2. In addition, the tank 30 comprises, for each conduit 48 and each of the first and second walls 42.1, 42.2, a connecting zone 52.1, 52.2 which surrounds the first or second orifice 50.1, 50.2 and comprises a connection 54.1, 54.2 connecting the conduit 48 and the first or second wall 42.1, 42.2.

Claims

1. Tank comprising an outer enclosure (32), an inner enclosure (34) positioned in the outer enclosure (32), first and second connection systems (36) connecting the outer and inner enclosures (32, 34), a first wall (42.1) connected to the outer enclosure (32), a second wall (42.2) connected to the inner enclosure (34), and at least one duct (48) passing through the first and second walls (42.1, 42.2), each of the first and second walls (42.1, 42.2) having at least one attachment zone (46) connected to the inner or outer enclosure (32, 34) and, for each duct (48), an orifice (50.1, 50.2) through which the duct (48) passes, and a connection zone (52.1, 52.2) surrounding the orifice (50.1, 50.2) and comprising a connection (54.1, 54.2) connecting the duct (48) and the first or second wall (42.1, 42.2); characterized in that at least one wall (56) of the first and second walls (42.1, 42.2) comprises at least one deformable zone (58) interposed between the attachment zone (46) and the connection zone (52.1, 52.2), the deformable zone (58) being configured to allow the connection zone (52.1, 52.2) to move with respect to the attachment zone (46).

2. Tank according to the preceding claim, characterized in that each deformable zone (58) describes a circle.

3. Tank according to the preceding claim, characterized in that each deformable zone (58) comprises at least one undulation describing a circle.

4. Tank according to the preceding claim, characterized in that each deformable zone (58) comprises a plurality of concentric undulations forming a bellows.

5. Tank according to one of the preceding claims, characterized in that the wall (56) has a first thickness outside the deformable zone(s) (58) and a second thickness, less than the first thickness, in each deformable zone (58).

6. Tank according to one of the preceding claims, characterized in that the wall (56) comprises, for each connection zone (52.1, 52.2), a deformable zone (58) surrounding the connection zone (52.1, 52.2).

7. Tank according to one of Claims 1 to 5, characterized in that the wall (56) comprises a deformable zone (58) surrounding a plurality of connection zones (52.1, 52.2).

8. Tank according to the preceding claim, characterized in that the attachment zone (46) is in the form of a ring, and in that the deformable zone (58) and the attachment zone (46) are concentric, the deformable zone (58) surrounding all the connection zones (52.1, 52.2).

9. Tank according to one of the preceding claims, characterized in that the first connection system comprises: - a tubular interface (38) passing through the outer and inner enclosures (32, 34), connected thereto and having a first end (38.1) opening out to the outside of the outer enclosure (32), and a second end (38.2) opening out to the inside of the inner enclosure (34), - a first closure plate closing the first end (38.1) of the tubular interface (38) and comprising at least one deformable zone (58), - a second closure plate closing the second end (38.2) of the tubular interface (38) and comprising at least one deformable zone (58).

10. Tank according to one of the preceding claims, characterized in that each duct (48, 48', 48") comprises an intermediate segment (60, 60', 60") situated between the first and second walls (42.1, 42.2) and having an excess length between said first and second walls (42.1, 42.2).

11. Tank according to the preceding claim, characterized in that each intermediate segment (60) has an axis (A48) which follows a trajectory in the form of a circular helix.

12. Tank according to the preceding claim, characterized in that the tank comprises a plurality of ducts (48, 48', 48") passing through the first and second walls (42.1, 42.2), the helical trajectories of the intermediate segments (60, 60', 60") of the different segments (48, 48', 48") having approximately the same helix axis.

13. Aircraft comprising at least one tank according to one of the preceding claims.