Tank

Abstract

To provide a technique for maintaining performance for shutting off fluid in a tank.SOLUTION: The tank body includes a fiber-reinforced plastic layer and a metal layer in contact with the fiber-reinforced plastic layer.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present specification relates to a tank. [Background technology]

[0002] Patent Document 1 discloses a tank that forms a space for containing a fluid. The tank includes a fiber-reinforced plastic layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-183753 Summary of the Invention [Problem to be solved by the invention]

[0004] The fiber-reinforced plastic layer is formed by curing a resin impregnated into fibers. The resin may peel off from the fibers due to aging or other reasons. If cracks develop at the location where the resin peels off from the fibers, the barrier performance of the tank may be reduced. This specification provides a technology for maintaining the barrier performance of the tank. [Means for solving the problem]

[0005] The present specification discloses a tank for containing a liquid, the tank including a tank body that forms a space for containing the fluid, the tank body including a fiber-reinforced plastic layer and a metal layer in contact with the fiber-reinforced plastic layer.

[0006] According to the above configuration, even if a crack develops in the fiber-reinforced plastic layer, the metal layer prevents the fluid in the tank from permeating through the fiber-reinforced plastic layer, thereby maintaining the barrier performance of the tank.

[0007] In addition, the thermal conductivity of the metal layer is higher than that of the fiber-reinforced plastic layer, and adding a metal layer can help transfer heat from inside the tank to the outside.

[0008] Furthermore, when a crack occurs in the fiber-reinforced plastic layer, a load is also placed on the metal layer that contacts the fiber-reinforced plastic layer. By diagnosing the sound caused by the load on the metal layer using the acoustic emission method (AE method), it is possible to detect signs of crack propagation in the fiber-reinforced plastic layer. In particular, while the breakage of the fibers and resin in the fiber-reinforced plastic layer is relatively instantaneous, the breakage of the metal is relatively prolonged. While it is difficult to detect signs using the AE method from instantaneous sounds, the prolonged sounds of the metal layer make it possible to detect signs using the AE method.

[0009] Details and further improvements of the technology disclosed in this specification are described in the following "Description of Embodiments of the Invention." [Brief explanation of the drawings]

[0010] [Figure 1] FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is an enlarged view of a region III in FIG. 2. [Figure 4] FIG. 10 is an enlarged view according to the second embodiment. [Figure 5] FIG. 10 is an enlarged view according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Structure of Tank 2; Figure 1, Figure 2, Figure 3) Tank 2 contains a fluid such as fuel. The fuel may be, for example, high-pressure hydrogen gas, compressed natural gas, or liquid hydrogen. Tank 2 is mounted, for example, on a vehicle. The vehicle may be, for example, an engine vehicle such as a fuel cell vehicle or a hydrogen vehicle. Note that a cylindrical coordinate system (D1, D2, D3) is depicted in the drawing. Directions D1, D2, and D3 represent the axial direction, radial direction, and circumferential direction, respectively. The axial direction D1 coincides with the axis of tank 2.

[0012] The tank 2 includes a tank body 10 that forms a fluid storage space 12 (see FIG. 2). The tank body 10 has a cylindrical portion 14 and a pair of dome portions 16 provided on both sides of the cylindrical portion 14 in the axial direction D1. A nozzle 18 is provided on one of the pair of dome portions 16. A fluid supply pipe (not shown) and a fluid discharge pipe (not shown) are connected to the nozzle 18.

[0013] As shown in FIG. 2, the tank body 10 includes a liner layer 30 and a reinforcing layer 32. The liner layer 30 is a mold for the cylindrical portion 14 and the dome portion 16. The liner layer 30 is made of, for example, resin. The reinforcing layer 32 is formed by winding a fiber-reinforced plastic filament around the liner layer 30. The filament is wound around the liner layer 30 by a so-called filament winding method.

[0014] As shown in Figures 1 and 3, the reinforcing layer 32 includes a hoop layer 20, a first helical layer 22, and a second helical layer 24. The hoop layer 20 has a structure in which fiber-reinforced plastic filaments are wound only around the cylindrical portion 14. In the hoop layer 20, the filaments are wound in a direction substantially perpendicular to the axial direction D1. "Substantially perpendicular" refers to an angle within a range of plus or minus several degrees centered on 90 degrees. In the hoop layer 20, the filaments are wound around the liner layer 30 using so-called hoop winding.

[0015] The first helical layer 22 has a structure in which the filament is wound around a pair of dome portions 16. In the first helical layer 22, the filament is wound at a relatively small angle with respect to the axial direction D1. On the other hand, in the second helical layer 24, the filament is wound at a relatively large angle with respect to the axial direction D1. The angle at which the filament is wound in the second helical layer 24 is larger than the angle at which the filament is wound in the first helical layer 22. In the second helical layer 24, the filament is wound not only around the cylindrical portion 14 but also around the dome portion 16. In the first helical layer 22 and the second helical layer 24, the filament is wound around the liner layer 30 using what is called helical winding.

[0016] In the hoop layer 20, the first helical layer 22, and the second helical layer 24, the filaments are wound without any gaps between them. As shown in FIG. 3 , the hoop layer 20, the first helical layer 22, and the second helical layer 24 are stacked along the radial direction D2. In this embodiment, the hoop layer 20 is formed on the liner layer 30, the first helical layer 22 is formed on the hoop layer 20, and the second helical layer 24 is formed on the first helical layer 22. In a modified example, the hoop layer 20 may be formed on the first helical layer 22 and the second helical layer 24, and the reinforcing layer 32 may not include the second helical layer 24.

[0017] As shown in FIG. 3 , a metal film 40 is laminated on the filaments that make up the hoop layer 20. The metal film 40 is laminated on the surface of the hoop layer 20 that faces the liner layer 30. Specifically, the metal film 40 is formed on the surface of the filament before the resin hardens by vacuum deposition, sputtering, or the like, and the filament with the metal film 40 formed thereon is wound around the liner layer 30. The resin in the filament is then hardened to form the hoop layer 20. Because the filaments are wound without gaps between them, the metal films 40 of the filaments contact each other along the axial direction D1 and form a metal layer extending along the axial direction D1. The metal layer formed by the metal film 40 is located between the hoop layer 20 and the liner layer 30. The metal film 40 includes, for example, at least one of aluminum, copper, and gold.

[0018] Furthermore, a metal film 42 is also laminated on the filaments that make up the first helical layer 22, and a metal film 44 is also laminated on the filaments that make up the second helical layer 24. The metal layer made up of the metal film 42 is located between the hoop layer 20 and the first helical layer 22, and the metal layer made up of the metal film 44 is located between the first helical layer 22 and the second helical layer 24. The manufacturing method of the metal films 42 and 44 is the same as the manufacturing method of the metal film 40.

[0019] The thickness of each of the metal films 40, 42, and 44 in the radial direction D2 is, for example, several micrometers. The total thickness of the metal films 40, 42, and 44 is preferably 500 micrometers or less.

[0020] (Effects of this embodiment) The fiber-reinforced plastic layer is formed by hardening resin impregnated into the fibers. The resin may peel off from the fibers due to aging, etc. If cracks develop at the point where the resin peels off from the fibers, the barrier performance of the tank 2 may be reduced.

[0021] According to the configuration of this embodiment, even if a crack develops in the hoop layer 20 or the like in the reinforcing layer 32, the metal film 40 or the like prevents the fluid in the tank 2 from permeating the reinforcing layer 32. This allows the barrier performance of the tank 2 to be maintained.

[0022] In order to maintain the barrier performance of the tank 2, it is conceivable to insert a polymer film instead of the metal film 40 or the like. However, to reliably block fluid permeation, a polymer film thicker than the metal film 40 or the like is required. Therefore, by employing the metal film 40 or the like, the barrier performance of the tank 2 can be maintained without increasing the size of the tank 2.

[0023] Furthermore, the thermal conductivity of the metal film 40 or the like is higher than that of fiber-reinforced plastic. The metal layer formed by the metal film 40 or the like extends along the axial direction D1. Therefore, heat inside the tank 2 is transferred to the nozzle 18 via the metal layer and then released to the outside of the tank 2. Adding a metal layer formed by the metal film 40 or the like can promote the transfer of heat inside the tank 2 to the outside of the tank 2. In particular, the metal layer formed on the first helical layer 22 extends to the vicinity of the nozzle 18 and contributes to heat dissipation from the nozzle 18. Furthermore, the metal layer formed by the metal film 40 or the like can also improve heat dissipation in the direction along the radial direction D2.

[0024] Furthermore, when a crack occurs in the hoop layer 20, etc., a load is also placed on the metal layer in contact with the hoop layer 20, etc. By diagnosing the sound caused by the load on the metal layer using the acoustic emission method (AE method), signs of crack propagation in the hoop layer 20, etc. can be detected. In particular, while breakage of the fibers and resin of the hoop layer 20, etc., is relatively instantaneous, breakage of the metal is relatively prolonged. While it is difficult to detect signs of propagation using the AE method from instantaneous sounds, the prolonged sounds of the metal layer make it possible to detect signs using the AE method.

[0025] (Correspondence) The tank 2 and the tank body 10 are examples of a "tank" and a "tank body", respectively. The storage space 12, the cylindrical portion 14, and the dome portion 16 are examples of a "storage space", a "cylindrical portion", and a "dome portion", respectively. The liner layer 30 is an example of a "liner layer". The hoop layer 20 is an example of a "fiber-reinforced plastic layer" and a "hoop layer". The metal film 40 is an example of a "metal layer". The first helical layer 22 and the second helical layer 24 are examples of a "helical layer".

[0026] (Second Example) (Structure of Tank 2; Figure 4) In this embodiment, an underlayer 41 is formed between the hoop layer 20 and the metal film 40. The underlayer 41 is made of, for example, nickel. Underlayers 43 and 45 are also formed between the first helical layer 22 and the metal film 42 and between the second helical layer 24 and the metal film 44, respectively.

[0027] (Third Example) (Structure of Tank 2; Figure 5) In this embodiment, a metal film 40 is formed on the hoop layer 20, but no metal film is formed on the first helical layer 22 and the second helical layer 24. That is, the metal layer formed by the metal film 40 is located closer to the storage space 12 than the center position in the thickness direction (i.e., the radial direction D2) of the fiber-reinforced plastic layer formed by the hoop layer 20, the first helical layer 22, and the second helical layer 24. Heat inside the tank 2 is transferred to the metal layer through the liner layer 30, and then transferred along the axial direction D1 to the nozzle 18, and then released outside the tank 2. In this embodiment, as in the first embodiment, the transfer of heat inside the tank 2 to the outside of the tank 2 can be promoted.

[0028] (Modification of the third embodiment) In a modification of this embodiment, a metal layer may not be formed on the hoop layer 20, but may be formed on at least one of the first helical layer 22 and the second helical layer 24. In another modification, the first helical layer 22 may be formed on the liner layer 30, and the hoop layer 20 may be formed on the first helical layer 22. A metal layer may then be formed between the liner layer 30 and the first helical layer 22. The metal layer formed on the first helical layer 22 extends to the vicinity of the die 18 and contributes to heat dissipation from the die 18.

[0029] Hereinafter, points to note regarding the techniques shown in the embodiments will be described. The tank body 10 does not necessarily have to include the liner layer 30.

[0030] The metal layer may be formed on the fiber-reinforced plastic layer after winding the filaments around the liner layer 30 and curing the resin. In this case, the metal layer may be formed by a method such as electroless plating. [Explanation of symbols]

[0031] 2: Tank 10: Tank body 12: Containment space 14: Cylindrical part 16: Dome section 18: nozzle 20: Hoop layer 22: First helical layer 24: Second helical layer 30: Liner layer 32: Reinforcement layer 40: Metal film 41: Base layer 42: Metal film 43: Base layer 44: Metal film 45: Base layer D1: Axial direction D2 :Radial direction D3: Circumferential direction

Claims

1. A tank for containing a fluid, a tank body that forms a storage space for the fluid; The tank body is a fiber-reinforced plastic layer; A metal layer in contact with the fiber reinforced plastic layer, tank.

2. The tank according to claim 1 , wherein the metal layer is located closer to the storage space than a center position in a thickness direction of the fiber-reinforced plastic layer.

3. The tank body further includes a liner layer positioned between the storage space and the fiber-reinforced plastic layer, 2. The tank of claim 1, wherein the metal layer is located between the liner layer and the fiber-reinforced plastic layer.

4. The tank body has a cylindrical portion and a pair of dome portions provided on both sides of the cylindrical portion, the fiber-reinforced plastic layer includes a hoop layer having a structure in which a fiber-reinforced plastic filament is wound only around the cylindrical portion, and a helical layer in which a fiber-reinforced plastic filament is wound across the pair of dome portions, 2. The tank according to claim 1, wherein the metal layer is formed of a metal film laminated on the filaments that constitute the helical layer.

5. The tank according to claim 1 , wherein the metal layer comprises at least one of aluminum, copper, and gold.

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