Pressure container and method for forming gas barrier layer

Abstract

To make the thickness of a gas barrier layer thinner.SOLUTION: A pressure container A includes: a container body 30 in the inside of which high-pressure fluid is stored; a reinforcement layer 35 surrounding the outer surface of the container body 30; and a gas barrier layer 32 coating the inner surface of the container body 30. The gas barrier layer 32 is composed of coating film 14 coated on the inner surface of the container body 30 and having gas barrier property. The gas barrier layer 32 is composed of the coating film 14 coated on the molded container body 30, and thereby mechanical strength is not necessary for the gas barrier layer 32. The gas barrier layer 32 just requires a thickness necessary for exerting a gas barrier function.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a pressure vessel and a method for forming a gas barrier layer. [Background technology]

[0002] Pressure vessels that store high-pressure gas are required to have pressure resistance that can withstand the gas pressure and gas barrier properties to prevent leakage of the stored gas. The pressure vessel disclosed in Patent Document 1 includes a liner with gas barrier properties and an outer shell as a reinforcing means that covers the outside of the liner. The liner is made of synthetic resin such as high-density polyethylene. The outer shell is made of fiber bundles including carbon fiber and glass fiber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-21099 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure vessel of Patent Document 1, the outer shell is formed by winding a fiber bundle around the outer peripheral surface of the liner by filament winding. Therefore, in order to ensure the rigidity of the liner, the liner is formed to a thickness greater than that required to ensure the barrier properties.

[0005] The present invention was completed in view of the above circumstances, and an object of the present invention is to make it possible to reduce the thickness of a gas barrier layer. [Means for solving the problem]

[0006] The first disclosure is: A container body in which a high-pressure fluid is stored; A reinforcing layer surrounding the outer surface of the container body; A gas barrier layer covering the inner surface of the container body, The gas barrier layer is made of a coating film having gas barrier properties that is applied to the inner surface of the container body.

[0007] The second disclosure is: A method for forming a gas barrier layer on an inner surface of a container body constituting a pressure container, comprising the steps of: A paint made of a synthetic resin having gas barrier properties is applied to the inner surface of the base member constituting the container body, The coating material applied to the base member is heated to a molten state, and then cooled and solidified to form a gas barrier layer. Effect of the Invention

[0008] According to the above disclosure, the gas barrier layer need only have a thickness necessary to exhibit the gas barrier function. [Brief description of the drawings]

[0009] [Figure 1] Front view of the pressure vessel of Example 1 [Diagram 2] Cross-section of a pressure vessel [Diagram 3] FIG. 1 is a partially enlarged cross-sectional view showing a connection structure between a cylindrical member and a dome-shaped member; [Figure 4] FIG. 1 is a perspective view showing a state in which a fiber-reinforced resin material is wound around a mandrel in a manufacturing process of a cylindrical base member constituting a dome-shaped member; [Diagram 5] 1 is a perspective view showing a heating step and a cooling step in a manufacturing process of a cylindrical base member; [Figure 6] FIG. 11 is a perspective view showing a state in which the formed cylindrical base member is removed from the mandrel during the manufacturing process of the cylindrical base member; [Figure 7] FIG. 11 is a perspective view showing a state in which powder paint is applied to the inner peripheral surface of a cylindrical base member; [Figure 8] 1 is a cross-sectional view showing a process of heating and a process of cooling the powder paint applied to a cylindrical base member; [Figure 9]5 is a cross-sectional view showing a process of heating and a process of cooling the powder coating material applied to the cylindrical base member in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First, embodiments of the present disclosure will be listed and described. Any combination of the following embodiments without causing any contradiction is also included in the embodiment for carrying out the present invention.

[0011] (1) The pressure vessel of the first disclosure comprises a vessel body in which a high-pressure fluid is stored, a reinforcing layer surrounding the outer surface of the vessel body, and a gas barrier layer covering the inner surface of the vessel body. The gas barrier layer is made of a coating film having gas barrier properties that is applied to the inner surface of the vessel body. According to this configuration, since the gas barrier layer is made of a coating film that is applied to the molded vessel body, the gas barrier layer does not need to have mechanical strength. Therefore, the thickness of the gas barrier layer need only be a thickness necessary to exhibit gas barrier function.

[0012] (2) The second disclosure is a method for forming a gas barrier layer on the inner surface of a container body constituting a pressure vessel, in which a paint made of a synthetic resin having gas barrier properties is applied to the inner surface of a base member constituting the container body, and the paint applied to the base member is heated to a molten state, and then cooled to solidify, thereby forming a gas barrier layer. According to this formation method, the gas barrier layer is formed by applying a paint having gas barrier properties to a molded base member, so that the gas barrier layer does not need to have mechanical strength. Therefore, the thickness of the gas barrier layer need only be a thickness necessary to exhibit the gas barrier function. Since the paint is baked onto the base member by being in a molten state, the adhesion strength of the gas barrier layer to the base member is high.

[0013] (3) In (2), it is preferable to use a powder paint as the paint, generate a voltage difference between the nozzle and the base member, and apply the powder paint discharged from the nozzle to the base member by electrostatic attraction. According to this method, the powder paint can be applied uniformly over the entire inner circumferential surface of the base member by electrostatic attraction, so that the thickness of the gas barrier layer can be made uniform.

[0014] (4) In (2) or (3), it is preferable that the base member includes a cylindrical base member having both ends open and a dome-shaped base member closing the openings of the cylindrical base member, the gas barrier layer includes a cylindrical barrier layer formed on the inner peripheral surface of the cylindrical base member and a dome-shaped barrier layer formed on the inner surface of the dome-shaped base member, and the cylindrical barrier layer is formed by applying a paint made of a synthetic resin having gas barrier properties to the inner peripheral surface of the molded cylindrical base member, heating the paint applied to the cylindrical base member to a molten state, and then cooling and solidifying it. According to this method, the base member has a divided structure consisting of a cylindrical base member and a dome-shaped base member, which makes it easier to apply the paint.

[0015] (5) In (4), in the step of melting the paint to form a coating film and the step of cooling the molten coating film, it is preferable to rotate the cylindrical base member with its axis horizontal. With this method, even if the coating film before solidification sags due to gravity, the thickness of the gas barrier layer can be made uniform.

[0016] (6) In the above (4) to (5), it is preferable that the coating material applied to the cylindrical base member is heated by a heater accommodated in the hollow of the cylindrical base member. This method suppresses heat transfer to the cylindrical base member, thereby suppressing problems caused by overheating of the cylindrical base member.

[0017] <Example 1> A first embodiment of the present invention will be described below with reference to Figs. 1 to 8. A pressure vessel A in this first embodiment is a capsule-shaped vessel for storing a high-pressure fluid (liquefied gas or vaporized gas) such as hydrogen or ammonia. Structurally, the pressure vessel A is configured to include one cylindrical member 10, a pair of dome-shaped members 20 each having a roughly hemispherical shape, and a reinforcing layer 35. The dome-shaped member 20 is assembled to the cylindrical member 10 so as to close the openings at both ends. The reinforcing layer 35 surrounds and reinforces the cylindrical member 10 and the dome-shaped member 20 in the assembled state.

[0018] As shown in Fig. 2, the tubular member 10 is composed of a cylindrical tubular base member 11 and a tubular barrier layer 13. The tubular base member 11 is made of a fiber-reinforced resin material 12 (see Fig. 4) such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). As shown enlarged in Fig. 3, the tubular barrier layer 13 is formed so as to be laminated on the entire inner peripheral surface of the tubular base member 11 and on the outer peripheral edges of the openings at both ends of the tubular base member 11. The tubular barrier layer 13 is made of a coating film 14 made of a synthetic resin having gas barrier properties. Examples of synthetic resins having gas barrier properties include ethylene-vinyl alcohol copolymer resin (EVOH) and polyamide (PA).

[0019] 2, the dome-shaped member 20 is composed of a dome-shaped base member 21 having a generally hemispherical shape, and a dome-shaped barrier layer 22. Like the cylindrical base member 11, the dome-shaped base member 21 is made of a fiber-reinforced resin material 12 such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The dome-shaped barrier layer 22 is formed so as to be laminated over the entire inner peripheral surface of the dome-shaped base member 21. Like the cylindrical barrier layer 13, the dome-shaped barrier layer 22 is made of a resin coating film 14 having gas barrier properties.

[0020] When the cylindrical member 10 and the dome-shaped member 20 are assembled, the cylindrical base member 11 and the dome-shaped base member 21 form a capsule-shaped container body 30 (see Figs. 2 and 3). The container body 30 is a member that forms a storage space 31 that stores a high-pressure fluid. When the cylindrical member 10 and the dome-shaped member 20 are assembled, the cylindrical barrier layer 13 and the dome-shaped barrier layer 22 form a gas barrier layer 32 that covers the entire inner surface of the container body 30. The gas barrier layer 32 exerts a gas barrier function that prevents the vaporized gas stored in the pressure vessel A from leaking out of the pressure vessel A through the container body 30 (the cylindrical base member 11 and the dome-shaped base member 21).

[0021] The reinforcing layer 35 is formed so as to cover the outer surface of the container body 30 (the cylindrical base member 11 and the dome-shaped base member 21). The reinforcing layer 35 is made of a fiber-reinforced resin material 12 such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP) like the cylindrical base member 11 and the dome-shaped base member 21. The reinforcing layer 35 has both a holding function of holding the cylindrical member 10 and the dome-shaped member 20 in a combined state and a reinforcing function of increasing the strength and rigidity of the container body 30.

[0022] The pressure vessel A is manufactured by the steps of manufacturing the cylindrical member 10 and the dome-shaped member 20 separately, combining the cylindrical member 10 and the dome-shaped member 20, and forming the reinforcing layer 35. The cylindrical member 10 is manufactured by the steps of manufacturing the cylindrical base member 11, and forming the cylindrical barrier layer 13 on the manufactured cylindrical base member 11.

[0023] In manufacturing the cylindrical base member 11, first, as shown in FIG. 4, a long and thin fiber reinforced resin material 12 is hoop-wound around the outer circumferential surface of a cylindrical mandrel 40 by a filament winding method. The fiber reinforced resin material 12 is a fiber bundle (not shown) made of thread-like fibers such as carbon fiber, glass fiber, and Kepler fiber, impregnated with a liquid thermosetting resin (e.g., epoxy resin), or a fiber bundle impregnated with a thermosetting resin in a semi-cured state (prepreg fiber). Next, the fiber reinforced resin material 12 is heated, for example, to 150°C to 160°C while still wound around the mandrel 40 to make it molten, and then cooled and solidified (see FIG. 5). After the fiber reinforced resin material 12 is solidified, the solidified fiber reinforced resin material 12 (cylindrical base member 11) is removed from the mandrel 40 as shown in FIG. 6. In this manner, the cylindrical base member 11 is manufactured.

[0024] Next, a cylindrical barrier layer 13 is formed on the cylindrical base member 11. The cylindrical barrier layer 13 is formed by electrostatic powder coating. Specifically, as shown in FIG. 7, a coating gun 42 connected to a high voltage generator 41 is used, and a nozzle 43 of the coating gun 42 is set so as to face the inside of the cylindrical base member 11. The cylindrical base member 11 is connected to an earth member 44. A powder coating material 45 made of a synthetic resin having gas barrier properties is discharged from the nozzle 43 of the coating gun 42, and the powder coating material 45 is applied to the entire inner peripheral surface of the cylindrical base member 11 and the outer peripheral edge portions of the openings at both ends of the cylindrical base member 11 by electrostatic attraction. When applying the powder coating material 45, a mask is applied in advance to the area of ​​the outer peripheral surface of the cylindrical base member 11 except for both ends. As the powder coating material 45, an ethylene vinyl alcohol copolymer resin (EVOH), polyamide (PA), or the like is used.

[0025] After the powder paint 45 has been applied, the cylindrical base member 11 is set in a heating device 46 as shown in Fig. 8. A heater 48 is disposed on the inner wall surface of the heating device 46. A pair of rollers 47, each with its axis oriented horizontally, are disposed in the heating device 46 so as to be aligned in a horizontal direction intersecting the axis. The cylindrical base member 11 is placed on both rollers 47. The rollers 47 are driven to rotate by a motor (not shown), so that the cylindrical base member 11 receives a rotational force from the rollers 47 and rotates.

[0026] The cylindrical base member 11 is heated to, for example, 150°C to 160°C while rotating. The powder coating material 45 applied to the cylindrical base member 11 melts due to the heat and drips due to gravity, but since the cylindrical base member 11 is rotating, the molten powder coating material 45 does not gather in one place. The molten powder coating material 45 is uniformly welded to the inner peripheral surface of the cylindrical base member 11 to form a coating film 14 with a uniform thickness over the entire circumference. After a predetermined heating time has elapsed, the heating process is terminated, and the cylindrical base member 11 and the coating film 14 are cooled. The cylindrical base member 11 continues to rotate during the cooling process. When the coating film 14 solidifies, a cylindrical barrier layer 13 integrated with the cylindrical base member 11 is formed. With the above, the manufacturing process of the cylindrical member 10 is completed.

[0027] The dome-shaped member 20 is manufactured by the following procedure: manufacturing a dome-shaped base member 21, and forming a dome-shaped barrier layer 22 on the manufactured dome-shaped base member 21. When manufacturing the dome-shaped base member 21, a fiber reinforced resin material 12 is attached to the outer peripheral surface of a substantially hemispherical jig (not shown), and the attached fiber reinforced resin material 12 is heated to a molten state. Thereafter, the fiber reinforced resin material 12 is cooled and solidified. The solidified fiber reinforced resin material 12 is removed from the jig to produce the dome-shaped base member 21.

[0028] Next, a dome-shaped barrier layer 22 is formed on the dome-shaped base member 21. The dome-shaped barrier layer 22 is formed by electrostatic powder coating, similar to the cylindrical barrier layer 13. A powder coating material 45 is applied to the inner surface of the dome-shaped base member 21, and the coating film 14 and the dome-shaped base member 21 are heated while changing the orientation of the dome-shaped base member 21 three-dimensionally. The molten coating film 14 is integrated with the dome-shaped base member 21 with a uniform thickness without collecting at a specific position. The dome-shaped base member 21 and the coating film 14 are cooled while changing the orientation of the dome-shaped base member 21 three-dimensionally, thereby forming a dome-shaped barrier layer 22 with a uniform thickness. This completes the production of the dome-shaped member 20.

[0029] The manufactured cylindrical member 10 and the pair of dome-shaped members 20 are combined. When combining, as shown in Fig. 3, the opening edges of the dome-shaped member 20 are fitted onto the openings at both ends of the cylindrical member 10, and the cylindrical barrier layer 13 and the dome-shaped barrier layer 22 are brought into close contact with each other. As a result, the cylindrical base member 11 and the dome-shaped base member 21 form the container body 30 and the storage space 31, and the cylindrical barrier layer 13 and the dome-shaped barrier layer 22 form a gas barrier layer 32 on the inner surface of the container body 30.

[0030] Next, a reinforcing layer 35 is formed on the outer surface of the container body 30. The reinforcing layer 35 is formed by the filament winding method, as in the case of the cylindrical base member 11. That is, the elongated fiber reinforced resin material 12 is hoop-wound on the outer surface of the container body 30. The fiber reinforced resin material 12 is the same material as that used for forming the cylindrical base member 11 and the dome-shaped base member 21. The cylindrical base member 11 and the dome-shaped base member 21 constituting the container body 30 have strength and rigidity that can withstand the filament winding method, so that when the fiber reinforced resin material 12 is wound on the outer surface of the container body 30, there is no problem such as deformation of the container body 30. The fiber reinforced resin material 12 wound around the container body 30 is heated to adhere to the outer surface of the container body 30. With the above, the molding of the reinforcing layer 35 and the manufacture of the pressure vessel A are completed.

[0031] The pressure vessel A of the present embodiment 1 has a capsule-shaped vessel body 30, a reinforcing layer 35, and a gas barrier layer 32. The vessel body 30 is constructed by assembling a dome-shaped base member 21 to the openings at both ends of a cylindrical base member 11. A high-pressure fluid is stored inside the vessel body 30 (storage space 31). The reinforcing layer 35 surrounds the outer surface of the vessel body 30. The gas barrier layer 32 is formed so as to cover the inner surface of the vessel body 30, and is made of a coating film 14 having gas barrier properties that is applied to the inner surface of the vessel body 30. Since the gas barrier layer 32 is made of the coating film 14 that is applied to the molded vessel body 30, the gas barrier layer 32 does not need to have mechanical strength. The thickness of the gas barrier layer 32 need only be a thickness necessary to exhibit the gas barrier function.

[0032] In this Example 1, a method for forming a gas barrier layer 32 on the inner surface of the container body 30 constituting the pressure container A is disclosed. The gas barrier layer 32 is formed through a coating process, a heating process, and a cooling process. In the coating process, a powder coating material 45 made of a synthetic resin having gas barrier properties is applied to the inner surfaces of the cylindrical base member 11 and the dome-shaped base member 21 constituting the container body 30. In the heating process, the powder coating material 45 applied to the cylindrical base member 11 and the dome-shaped base member 21 is heated to a molten state. In the cooling process, the powder coating material 45 in the molten state is cooled and solidified. Through the above processes, the gas barrier layer 32 is formed.

[0033] In this formation method, the gas barrier layer 32 is formed by applying a paint having gas barrier properties to a molded base member, so the gas barrier layer 32 does not need to have any mechanical strength. Therefore, the thickness of the gas barrier layer 32 need only be a thickness necessary to exhibit the gas barrier function. The paint is baked onto the base member by being in a molten state, so the adhesion strength of the gas barrier layer 32 to the base member is high.

[0034] The gas barrier layer 32 is formed by electrostatic powder coating. Specifically, a voltage difference is generated between the nozzle 43 and the base members 11, 21, and the powder paint 45 discharged from the nozzle 43 is applied to the cylindrical base member 11 and the dome-shaped base member 21 by electrostatic attraction. According to this method, the powder paint 45 can be applied uniformly over the entire inner circumferential surfaces of the base members 11, 21 by electrostatic attraction, so that the thickness of the gas barrier layer 32 can be made uniform.

[0035] As described above, the base members constituting the container body 30 include the cylindrical base member 11 having both open ends, and the dome-shaped base member 21 that closes the openings of the cylindrical base member 11. The gas barrier layer 32 includes a cylindrical barrier layer 13 formed on the inner peripheral surface of the cylindrical base member 11, and a dome-shaped barrier layer 22 formed on the inner surface of the dome-shaped base member 21. The cylindrical barrier layer 13 is formed through a process of applying a paint made of a synthetic resin having gas barrier properties to the inner peripheral surface of the molded cylindrical base member 11, a process of heating the powder paint 45 applied to the cylindrical base member 11 to make it molten, and a process of cooling and solidifying the molten powder paint 45 (coating film 14).

[0036] The dome-shaped barrier layer 22 is formed through a process of applying powder paint 45 made of synthetic resin with gas barrier properties to the inner peripheral surface of the molded dome-shaped base member 21, a process of heating the powder paint 45 applied to the dome-shaped base member 21 to make it molten, and a process of cooling and solidifying the molten powder paint 45 (coating film 14). According to this method, the base member has a divided structure consisting of the cylindrical base member 11 and the dome-shaped base member 21, which makes it easy to apply the powder paint 45 to the cylindrical base member 11 and the dome-shaped base member 21.

[0037] In the step of melting the powder paint 45 to form the coating film 14 and in the step of cooling the molten coating film 14, the cylindrical base member 11 is rotated with its axis oriented horizontally. With this method, even if the coating film 14 before solidification sags due to gravity, the thickness of the gas barrier layer 32 (coating film 14) can be made uniform.

[0038] <Example 2> Next, a second embodiment of the present invention will be described with reference to Fig. 9. In the second embodiment, a part of the process for forming the cylindrical barrier layer 13 is different from that in the first embodiment. As the other configurations are the same as those in the first embodiment, the same reference numerals are used for the same configurations, and the description of the structure, action and effect will be omitted.

[0039] In the process of forming the cylindrical barrier layer 13, the process up to applying the powder coating material 45 to the inner peripheral surface of the molded cylindrical base member 11 by electrostatic coating is the same as that in Example 1. In this Example 2, a rod-shaped heater 49 is disposed concentrically with the cylindrical base member 11 within the hollow of the cylindrical base member 11 as a means for heating and melting the powder coating material 45 applied to the cylindrical base member 11. The cylindrical base member 11 is placed on a pair of rollers 47 and rotated, as in Example 1. The radiant heat from the heater 49 is transmitted to the coating film 14 on the inner peripheral surface of the cylindrical base member 11, but is not directly transmitted to the cylindrical base member 11.

[0040] In the second embodiment, the powder paint 45 applied to the cylindrical base member 11 is heated by the heater 49 housed in the hollow of the cylindrical base member 11, thereby suppressing the transfer of heat to the cylindrical base member 11. This makes it possible to suppress problems caused by the cylindrical base member 11 being overheated.

[0041] <Other Examples> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention. The gas barrier layer may be formed by spraying, not just by applying a coating material. The paint may be applied to the tubular base member without using electrostatic attraction. The paint may be a liquid paint dissolved in a solvent. The paint may be a thermosetting resin. [Explanation of symbols]

[0042] A…Pressure vessel 11...Cylindrical base member (base member) 13...Cylindrical barrier layer 14...Paint film 21... Dome-shaped base member (base member) 22...Dome-shaped barrier layer 30…Container body 32...Gas barrier layer 35…Reinforcement layer 43…Nozzle 45...Powder paint 49…Heater

Claims

1. A container body in which a high-pressure fluid is stored; A reinforcing layer surrounding the outer surface of the container body; A gas barrier layer covering the inner surface of the container body, The gas barrier layer is made of a coating film having gas barrier properties that is applied to the inner surface of the container body.

2. A method for forming a gas barrier layer on an inner surface of a container body constituting a pressure container, comprising the steps of: A paint made of a synthetic resin having gas barrier properties is applied to the inner surface of the base member constituting the container body, The method for forming a gas barrier layer includes heating the coating material applied to the base member to make it molten, and then cooling and solidifying the coating material to form the gas barrier layer.

3. A powder coating is used as the coating material, creating a voltage difference between the nozzle and the base member; The method for forming a gas barrier layer according to claim 2 , wherein the powder coating material discharged from the nozzle is applied to the base member by electrostatic attraction.

4. the base member includes a cylindrical base member having both ends open, and a dome-shaped base member closing the openings of the cylindrical base member, the gas barrier layer includes a cylindrical barrier layer formed on an inner peripheral surface of the cylindrical base member and a dome-shaped barrier layer formed on an inner surface of the dome-shaped base member, A coating material made of a synthetic resin having gas barrier properties is applied to the inner peripheral surface of the molded cylindrical base member; 4. The method for forming a gas barrier layer according to claim 2 or 3, wherein the coating material applied to the cylindrical base member is heated to a molten state and then cooled to solidify, thereby forming the cylindrical barrier layer.

5. 5. The method for forming a gas barrier layer according to claim 4, wherein in the step of melting the paint to form a coating film and the step of cooling the molten coating film, the cylindrical base member is rotated with its axis horizontal.

6. 5. The method for forming a gas barrier layer according to claim 4, wherein the coating material applied to the cylindrical base member is heated by a heater accommodated in the hollow of the cylindrical base member.

Images