A tank comprising a shell and at least one end wall assembled in such a way as to limit deformations of said end wall

Abstract

The invention relates to a tank comprising: a shell (42) having an edge (C2) connecting the first and second inner lateral surfaces (54.1, 56.1) of the first and second sections (54, 56); at least one end wall (44), positioned at the first section (54) of the shell (42), which has a central dome-shaped portion (48), a peripheral sleeve (50) positioned around the central portion (48), and a junction zone (52) connecting the central portion (48) and the peripheral sleeve (50) and having an edge (C1); a weld (58) connecting the first section (54) and the peripheral sleeve (50); and the edges (C1, C2) of the end wall (44) and the shell (42) having shapes configured to immobilize the junction zone (52) relative to the ferrule (42) in a radial direction.Figure 5.

Description

Title of the invention: Reservoir tank comprising a shell and at least one end wall assembled so as to limit the deformations of said end wall

[0001] The present application relates to a reservoir tank comprising a shell and at least one end wall assembled so as to limit the deformations of said end wall in operation as well as to a cryogenic tank comprising at least one such tank.

[0002] According to an embodiment visible in [Fig.l], an aircraft 10 comprises several cryogenic tanks 12 configured to store hydrogen in the cryogenic state, several engines 14 operating on hydrogen as well as a supply system 16 configured to convey the hydrogen from the tanks 12 to the engines 14. Each cryogenic tank 12 comprises an internal tank, an external tank in which the internal tank is positioned as well as two diametrically opposed connection systems connecting the internal and external tanks.

[0003] According to an embodiment visible in Figures 2 and 3, each tank 18 comprises a shell 20 which extends between first and second ends 20.1, 20.2 as well as first and second end walls 22, 24 positioned respectively at the first and second ends 20.1, 20.2 of the shell 20 to close it. The shell 20 is cylindrical and has an axis of revolution A20.

[0004] For the remainder of the description, a longitudinal direction is parallel to the axis of revolution A20. A longitudinal plane is a plane containing the axis of revolution A20. A transverse plane is perpendicular to the axis of revolution A20. A radial direction is perpendicular to the axis of revolution A20.

[0005] Each of the first and second ends 20.1, 20.2 of the ferrule 20 is circular and positioned in a transverse plane. Each end wall 22, 24 has a dome shape and comprises a free edge 22.1, 24.1 positioned in a plane and connected to the ferrule 20 by at least one weld line 26 which extends over the entire circumference of the ferrule 20.

[0006] According to a first configuration visible in figures 2 and 3, for each end wall 22, 24, the free edge 22.1, 24.1 and the first or second end 20.1, 20.2 of the ferrule 20 are positioned end to end and connected by the weld line 26.

[0007] According to a second configuration visible in [Fig.4], at least one of the end walls 22, 24 comprises: a. a central portion 28 in the shape of a dome which has a free edge 28.1 positioned in a first plane PI, the center of the central portion 28 being offset in a first direction relative to the first plane PI, b. a peripheral sleeve 30, positioned around the central part 28, which extends between first and second ends 30.1, 30.2, the second end 30.2 being offset in the first direction relative to the first end 30.1, c. a junction zone 32 connecting the free edge 28.1 of the central part 28 and the first end 30.1 of the peripheral sleeve 30.

[0008] Thus, the central part 28 and the peripheral sleeve 30 form a single and same piece which has an edge C1 positioned in the first plane P1.

[0009] In addition, the ferrule 20 has a counterbore 34 which has an inner lateral surface 34.1 and a bottom 34.2 distant from the first end 20.1 of the ferrule 20. The inner lateral surface 34.1 has a diameter substantially equal to the diameter of the outer lateral surface F30 of the peripheral sleeve 30. The counterbore 34 has a depth P (distance separating the bottom 34.2 of the counterbore 34 and the first end 20.1 of the ferrule 20) substantially equal to the distance separating the first and second ends 30.1, 30.2 of the peripheral sleeve 30.

[0010] According to this second configuration, the end wall 22, 24 is positioned in the counterbore 34, the edge C1 of the end wall 22, 24 being pressed against the bottom 34.2 of the counterbore 34, the second end 30.2 of the peripheral sleeve 30 being positioned substantially in the same plane as the first end 20.1 of the ferrule 20. The end wall 22, 24 and the ferrule 20 are connected by a weld 36, positioned between the ferrule 20 and the peripheral sleeve 30, which extends over the entire circumference of the ferrule from the second end 30.2 of the peripheral sleeve 30 and / or from the first end 20.1 of the ferrule 20.

[0011] The weld 36 has a length L (dimension taken parallel to the longitudinal direction) less than half the depth P of the counterbore 34.

[0012] Compared to the first configuration, this second solution makes it possible to simplify the assembly of the tank 18 and any possible disassembly of the end walls 22, 24.

[0013] As illustrated in [Fig. 4], due to the very high pressure of the fluid stored in the tank 18, the junction zone 32 tends to deform in the radial direction and to move away from the inner lateral surface 34.1 of the counterbore 34. Thus, in operation, the weld 36 is subjected to shear forces but also to bending and tensile forces due to the deformation of the junction zone 32. To avoid this deformation, the length L of the weld 36 is increased and / or the thickness (dimension taken in a transverse plane) of the peripheral sleeve 30 is increased.

[0014] These solutions are not satisfactory because they lead to increasing the mass of the tank, complicating its assembly or even making it impossible to dismantle and reassemble the end walls.

[0015] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0016] For this purpose, the invention relates to a tank comprising a shell which extends between first and second ends as well as at least one end wall positioned at the first end; the end wall comprising a central part in the shape of a dome, a peripheral sleeve positioned around the central part as well as a junction zone connecting the central part and the peripheral sleeve and having a first edge;the shell having an axis of revolution and comprising at least first and second sections, the first section extending between the first end of the shell and the second section, the first and second sections respectively having first and second internal lateral surfaces, the second internal lateral surface having a diameter smaller than that of the first internal lateral surface, the shell having a second edge connecting the first and second internal lateral surfaces; the tank comprising a weld connecting the first section of the shell and the peripheral sleeve of the end wall.;

[0017] According to the invention, the first and second edges of the end wall and of the ferrule have shapes configured to immobilize the junction zone relative to the ferrule in a radial direction perpendicular to the axis of revolution.

[0018] Since the junction zone of the end wall no longer deviates from the first section of the shell in operation due to the pressure of the fluid stored in the tank, the weld is no longer subjected to bending and tensile forces. Consequently, it is not necessary to stiffen the peripheral sleeve and / or reinforce the weld to withstand such forces.

[0019] According to another characteristic, at least one element among the first edge of the end wall and the second edge of the ferrule comprises or has at least one projecting shape. In addition, at least one second element, different from the first element, among the first edge of the end wall and the second edge of the ferrule comprises, for each projecting shape, or partially delimits at least one housing configured to house the projecting shape in order to immobilize the junction zone relative to the ferrule in the radial direction.

[0020] According to another characteristic, the second edge of the ferrule and the first edge of the end wall are positioned in transverse planes perpendicular to the axis of revolution.

[0021] According to another characteristic, the end wall comprises a shape, projecting relative to the first edge, in the form of a rib which extends over the entire circumference of the first edge. In addition, the ferrule has a housing in the form of a groove, which extends over the entire circumference of the second edge, configured to accommodate the rib.

[0022] According to another characteristic, the groove and the rib have complementary sections.

[0023] According to another characteristic, the rib is located in the extension of the external lateral surface of the peripheral sleeve.

[0024] According to another characteristic, the first and second sections are connected by a second truncated edge which flares away from the first end of the ferrule, the first edge of the end wall being truncated and having a conicity substantially identical to that of the second edge of the ferrule.

[0025] The invention also relates to a cryogenic tank comprising a vessel according to one of the preceding characteristics.

[0026] 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:

[0027] [Fig-1] is a perspective view of an aircraft,

[0028] [Fig.2] is a perspective view of a tank being assembled illustrating a assembly method of the prior art,

[0029] [Fig.3] is a perspective view of the tank visible in [Fig.2] at the end of assembly,

[0030] [Fig.4] is a longitudinal section of a portion of a tank illustrating an embodiment of the prior art,

[0031] [Fig.5] is a longitudinal section of a part of a tank illustrating an embodiment of the invention,

[0032] [Fig.6] is a longitudinal section of a portion of a tank illustrating another embodiment of the invention.

[0033] According to embodiments visible in Figures 5 and 6, a tank 40 comprises a shell 42 which extends between first and second ends 42.1, at least one first end wall 44 positioned at the first end 42.1 of the shell 42 to close it as well as at least one first assembly 46 connecting the first end wall 44 and the first end 42.1 of the shell 42.

[0034] For the sake of simplification, only the first end 42.1 of the ferrule is shown in Figures 5 and 6. Similarly, only a portion of the first assembly 46 connecting the first end wall 44 and the ferrule 42 is visible in Figures 5 and 6.

[0035] The tank 40 comprises a second end wall connected to the second end of the shell 42 by a second assembly. According to one configuration, the second end wall and the second assembly are respectively identical to the first end wall 44 and to the first assembly 46. Alternatively, the second end wall could be different from the first end wall 44 and / or the second assembly could be different from the first assembly 46.

[0036] According to one application, the tank 40 is configured to store a fluid such as hydrogen in a cryogenic state and at high pressure. According to one arrangement, a cryogenic tank intended to store a fluid in a cryogenic state, such as hydrogen for example, and to be positioned in a vehicle, such as an aircraft for example, comprises at least one tank. According to one embodiment, the cryogenic tank comprises an internal tank as well as an external tank in which the internal tank is positioned, at least one of the tanks among the internal and external tanks being in accordance with the tank 40, a portion of which is visible in FIGS. 5 and 6.

[0037] According to one configuration, the ferrule 42 is cylindrical or slightly frustoconical and has an axis of revolution. Each of the first and second ends 42.1 of the ferrule 42 is circular and positioned in a transverse plane.

[0038] According to the embodiments visible in Figures 5 and 6, the end wall 44 comprises: a. a central portion 48 in the shape of a dome which has a free edge 48.1 positioned in a first plane PI, the central portion 48 having a center offset in a first direction relative to the first plane PI, b. a peripheral sleeve 50, positioned around the central portion 48, which extends between first and second ends 50.1, 50.2, the second end 50.2 being offset in the first direction relative to the first end 50.1, c. a junction zone 52 connecting the free edge 48.1 of the central part 48 and the first end 50.1 of the peripheral sleeve 50.

[0039] Thus, the central part 48 and the peripheral sleeve 50 form a single and same piece. The junction zone 52 has a first edge Cl.

[0040] The central part 48 has an interior surface F48 oriented towards the interior of the tank 40. The peripheral sleeve 50 has an exterior lateral surface F50 opposite the central part 48 and oriented towards the shell 42.

[0041] The ferrule 42 comprises at least first and second sections 54, 56 coaxial with each other and with the axis of revolution of the ferrule 42, the first section 54 being cylindrical and extending between the first end 42.1 of the ferrule 42 and the second section 56. The first section 54 comprises a first inner lateral surface 54.1. The second section 56 comprises a second inner lateral surface 56.1 having a diameter smaller than that of the first inner lateral surface 54.1. The first section 54 is configured to house the peripheral sleeve 50 of the end wall 44.

[0042] According to a first configuration visible in [Fig.5], the first and second inner lateral surfaces 54.1, 56.1 of the first and second sections 54, 56 are connected by a second annular edge C2 positioned in a transverse plane (perpendicular to the axis of revolution of the ferrule 42). According to this first configuration, the first inner lateral surface 54.1 and the second edge C2 form a counterbore.

[0043] According to a second configuration visible in [Fig.6], the first and second internal lateral surfaces 54.1, 56.1 of the first and second sections 54, 56 are connected by a second truncated edge C2' which flares out as it moves away from the first end 42.1 of the ferrule 42.

[0044] The first inner lateral surface 54.1 of the first section 54 has a diameter D54.1 and a longitudinal dimension L54.1 corresponding to a dimension taken parallel to the longitudinal direction between the first end 42.1 of the ferrule 42 and the second edge C2, C2'. The diameter D54.1 of the first inner lateral surface 54.1 of the first section 54 is substantially equal to or very slightly greater than the diameter of the outer lateral surface F50 of the peripheral sleeve 50. According to one arrangement, the longitudinal dimension L54.1 of the first inner lateral surface 54.1 of the first section 54 is determined so that when the end wall 44 is positioned in the first section 54 and against the second edge C2, C2' of the ferrule 42, the second end 50.2 of the peripheral sleeve 50 is positioned approximately in the same transverse plane as the first end 42.1 of the ferrule 42.

[0045] The tank (more particularly the assembly 46) comprises a weld 58 positioned between the shell 42 and the end wall 44, more particularly between the first section 54 of the shell 42 and the peripheral sleeve 50 of the end wall 44, which extends from the second end 50.2 of the peripheral sleeve 50 of the end wall 44 and / or from the first end 42.1 of the shell 42. This weld 58 has a length L which corresponds to a dimension taken parallel to the longitudinal direction. According to one configuration, the length L is less than half the longitudinal dimension L54.1 of the first inner lateral surface 54.1 of the first section 54. This weld 58 extends continuously over the entire circumference of the shell 42. It can be produced by any suitable welding method such as a friction welding method for example.

[0046] According to a characteristic of the invention, the first and second edges C1, C2, C2' of the end wall 44 and of the shell 42 have shapes configured to immobilize the junction zone 52 relative to the shell 42 in a radial direction. The junction zone 52 of the end wall 44 does not deviate from the first section 54 of the shell 42, more particularly from its first inner lateral surface 54.1, in operation due to the pressure of the fluid stored in the tank 40, the weld 58 is no longer subjected to bending and tensile forces. Consequently, it is not necessary to stiffen the peripheral sleeve 50 and / or to reinforce the weld 58 to withstand such forces.

[0047] According to the second configuration visible in [Fig. 6], the first edge C1 of the end wall 44 has a projecting shape 60 and the second edge C2' of the ferrule 42 partially delimits a housing 62 configured to house the projecting shape 60 in order to immobilize the junction zone 52 relative to the ferrule 42 in the radial direction. According to one arrangement, the first edge C1 of the end wall 44 is frustoconical and has a conicity substantially identical to that of the second edge C2' of the ferrule 42. In addition, the ferrule 42 has a front groove, delimited by the first inner lateral surface 54.1 of the first section 54 and the second edge C2', which extends over the entire circumference of the ferrule 42 and houses at least one projecting part of the junction zone 52 of the end wall 44. According to one arrangement, the first edge C1 extends without discontinuity the inner surface F48 of the central part 48 of the end wall 44..

[0048] According to the first configuration visible in [Fig. 5], the first and second edges C1, C2 of the end wall 44 and of the ferrule 42 are positioned in transverse planes. According to the first configuration, at least one element among the first edge C1 of the end wall 44 and the second edge C2 of the ferrule 42 comprises at least one projecting shape 60. In addition, at least one second element, different from the first element, among the first edge C1 of the end wall 44 and the second edge C2 of the ferrule 42 comprises, for each projecting shape 60, at least one housing 62 configured to house the projecting shape 60 in order to immobilize the junction zone 52 relative to the ferrule 42 in the radial direction.

[0049] According to one arrangement, the end wall 44 comprises several protruding shapes 60 relative to the first edge C1, disjointed and distributed over the circumference of the first edge C1. In addition, the ferrule 42 comprises, at the level of the second edge C2, a housing 62 for each protruding shape 60.

[0050] According to another arrangement visible in [Fig. 5], the end wall 44 comprises a single shape, projecting 60 relative to the first edge C1, in the form of a rib which extends over the entire circumference of the first edge C1. In addition, the ferrule 42 has a single housing 62 in the form of a groove, which extends over the entire circumference of the second edge C2, configured to house the rib. This groove and this rib have complementary sections such as U-shaped for example. Of course, the invention is not limited to this geometry for the sections of the rib and the groove. According to one configuration, the rib is located in the extension of the outer lateral surface F50 of the peripheral sleeve 50. In addition, the groove-shaped housing 62 is located in the extension of the first inner lateral surface 54.1 of the first section 54.

Claims

Claims

1. A tank comprising a shell (42) extending between first and second ends (42.1) and at least one end wall (44) positioned at the first end (42.1); the end wall (44) comprising a dome-shaped central portion (48), a peripheral sleeve (50) positioned around the central portion (48) and a junction zone (52) connecting the central portion (48) and the peripheral sleeve (50) and having a first edge (Cl); the ferrule (42) having an axis of revolution and comprising at least first and second sections (54, 56), the first section (54) extending between the first end (42.1) of the ferrule (42) and the second section (56), the first and second sections (54, 56) having respectively first and second internal lateral surfaces (54.1, 56.1), the second internal lateral surface (56.1) having a diameter smaller than that of the first inner lateral surface (54.1), the shell (42) having a second edge (C2, C2') connecting the first and second inner lateral surfaces (54.1, 56.1); the tank comprising a weld (58) connecting the first section (54) of the shell (42) and the peripheral sleeve (50) of the end wall (44); characterized in that the first and second edges (C1, C2, C2') of the end wall (44) and of the shell (42) have shapes configured to immobilize the junction zone (52) relative to the shell (42) in a radial direction perpendicular to the axis of revolution.

2. Tank according to the preceding claim, characterized in that at least one element among the first edge (Cl) of the end wall (44) and the second edge (C2) of the shell (42) comprises or has at least one projecting shape (60) and in that at least one second element, different from the first element, among the first edge (Cl) of the end wall (44) and the second edge (C2) of the shell (42) comprises, for each projecting shape (60), or partially delimits at least one housing (62) configured to house the projecting shape (60) in order to immobilize the junction zone (52) relative to the shell (42) in the radial direction.

3. Tank according to the preceding claim, characterized in that the second edge (C2) of the ferrule (42) and the first edge (Cl) of the end wall (44) are positioned in transverse planes per- pendicular to the axis of revolution.

4. Tank according to one of claims 2 to 3, characterized in that the end wall (44) comprises a shape, projecting (60) relative to the first edge (Cl), in the form of a rib which extends over the entire circumference of the first edge (Cl) and in that the ferrule (42) has a housing (62) in the form of a groove, which extends over the entire circumference of the second edge (C2), configured to house the rib.

5. Tank according to the preceding claim, characterized in that the groove and the rib have complementary sections.

6. Tank according to one of claims 4 to 5, characterized in that the peripheral sleeve (50) has an external lateral surface (F50) oriented towards the first section (54) and in that the rib is located in the extension of the external lateral surface (F50) of the peripheral sleeve (50).

7. Tank according to claim 1 or 2, characterized in that the first and second sections (54, 56) are connected by a second frustoconical edge (C2') which flares away from the first end (42.1) of the shell (42) and in that the first edge (Cl) of the end wall (44) is frustoconical and has a conicity substantially identical to that of the second edge (C2') of the shell (42).

8. Cryogenic tank comprising at least one vessel according to one of the preceding claims.

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