JP2013238319A - Pressure vessel for storing compressed gas medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite pressure vessel which excludes the danger to surrounding parts due to gas flowing out at a high rate.SOLUTION: A pressure vessel (10) for storing a compressed gas medium includes: a liner (12) which demarcates an inner space (14) for storing a gas medium; and a cover (16) which surrounds the liner (12) and stabilizes the pressure vessel (10) in form, wherein a gas-permeable intermediate layer (36) is disposed between the liner (12) and the cover (16), the intermediate layer is connected with the outside of the cover (16) on at least one portion, and gas passing through the liner (12) can leak out from the pressure vessel (10) through the intermediate layer (36).

Description

  The present invention relates to a pressure vessel for storing a pressurized gaseous medium. The invention relates in particular to such a pressure vessel according to the preamble of claim 1 or claim 5.

  Such a pressure vessel is also called a composite pressure vessel, and is known from Patent Document 1, for example. These include a liner that divides an internal space that stores the gaseous medium, and a coating that surrounds the liner and acts to stabilize the shape of the pressure vessel. The liner is usually made of a plastic material and the coating is made of a fiber composite material.

  Such a type of pressure vessel is used, for example, as a hydrogen tank in a fuel cell system and can store gaseous hydrogen at a positive pressure of several hundred bar.

  It has been confirmed that when such a composite pressure vessel is disposed of after a long period of use, gaseous hydrogen flows out of the pressure vessel coating at a relatively high rate. For this reason, a pressure vessel that reduces the risk of hydrogen flowing out is required.

  Furthermore, a multi-layer pressure vessel containing high-temperature hydrogen is known from US Pat. No. 6,057,049, in which case hydrogen passing through the innermost metal layer of the wall is caused by hydrogen erosion of the metal layer outside the vessel wall and / or In order to prevent embrittlement, it is discharged from the space between the innermost metal layers.

  Patent Document 3 describes a composite pressure vessel having an internal tank and an external tank. In order to protect the external tank from hydrogen erosion through the internal tank and thereby improve the durability of the entire pressure vessel, a catalyst layer is provided between the internal tank and the external tank. Convert to a stable compound.

European Patent Application Publication No. 0753700A1 German Patent Application Publication No. 3308276A1 JP 2007-278482 A

  The object of the present invention is to provide a composite pressure vessel of the kind mentioned at the outset, which eliminates the danger to the periphery due to the gas flowing out at a high rate.

  The problem is that the gaseous medium passing through the liner is continuously discharged from the pressure vessel to the periphery at a low rate, so that when the pressure vessel is disposed of over a long period of use, the gaseous medium is rapidly discharged at a high rate. Solved by preventing spillage. That is, the gas passing through the liner is collected in a pocket between the liner and the coating, and then the liner and the coating are separated when the pressure vessel is disposed of, and the gas is pressurized at a high rate at a stroke. Outflow from the container to the periphery is prevented.

  In accordance with a first aspect of the present invention, a pressure vessel for storing a pressurized gas medium includes a liner that limits an internal space for containing the gas medium, and a coating that surrounds the liner and stabilizes the pressure vessel in shape. And have. In accordance with the present invention, the pressure vessel coating is at least partially gas permeable so that gas passing through the liner can escape from the pressure vessel through the coating.

  The construction of such a pressure vessel, comprising at least partly a gas permeable coating, allows gas passing through the liner to be continuously discharged from the pressure vessel to the periphery at a low rate. This method prevents gas passing through the liner from being accumulated between the liner and the coating, and discharging the gas to the periphery at a high rate when the pressure vessel is disposed.

In an embodiment of the invention, the pressure vessel coating is at least partially formed porous. For example, the pressure vessel covering is formed from a fiber material that is bonded by a resin material, and the cured resin material is at least partially porous.

  As an alternative or additional method, the cover of the compression vessel is provided with holes at defined locations, which connect the inside and the outside of the cover.

  In another embodiment of the present invention, a coating (such as a lacquer coat) is applied to the outside of the pressure vessel coating, which coating is similarly gas permeable at least in the gas permeable coating. .

  In accordance with a second aspect of the present invention, a pressure vessel for storing a pressurized gas medium includes a liner that limits an internal space that houses the gas medium, and a coating that surrounds the liner and stabilizes the shape of the pressure vessel. ,have. In accordance with the present invention, a gas permeable intermediate layer is provided between the liner and the coating, and this intermediate layer is connected to the outside of the coating at least at one location, so that the gas passing through the liner is It can escape from the pressure vessel through the intermediate layer.

  Due to the construction of the pressure vessel with an at least partially gas permeable intermediate layer between the liner and the coating, the gas passing through the liner is continuously discharged from the pressure vessel to the periphery at a low rate. Will be able to. This method prevents gas passing through the liner from being collected between the liner and the coating, and when the gas is disposed of the pressure vessel, it is prevented from being discharged to the periphery at a high rate.

  In an embodiment of the present invention, the intermediate layer is formed at least partially porous.

In another embodiment of the present invention, a gas treatment means is disposed at a connection portion between the intermediate layer and the outer coating, which is formed, for example, by impregnating the intermediate layer with a corresponding gas treatment agent. Yes.
This gas treatment means can have, for example, an oxidation catalytic converter. When the gaseous medium stored in the compression vessel is hydrogen, the hydrogen that passes through the liner and flows through the intermediate layer is oxidized into water by this oxidation catalytic converter, and can be discharged to the surroundings without danger. it can.

  In another embodiment of the invention, a connecting portion connecting the intermediate layer and the outside of the coating is provided at the neck portion of the compression vessel. In this case, it is preferably the filling opening and / or the discharge opening of the compression vessel.

  The foregoing and other features and advantages of the present invention will become more readily apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings.

It is sectional drawing of the composite pressure vessel of this invention. It is an enlarged view of the partial cross section of the conventional composite pressure vessel (before disposal). It is an enlarged view of the partial cross section of the conventional composite pressure vessel (after disposal). It is an enlarged view of the partial cross section of the compound pressure vessel (before disposal) based on the 1st example of the present invention. It is an enlarged view of the partial cross section of the compound pressure vessel (after disposal) based on a 1st Example. It is sectional drawing of the composite compression container based on the 2nd Example of this invention.

  The invention is described below on the basis of, for example, a compression vessel that stores gaseous hydrogen under a pressure of 700 bar. This compression container can be used for a fuel cell system, for example. However, the present invention is not limited to this gaseous medium, this pressure inside the compression vessel and this application.

  First, the basic structure of a composite pressure vessel to which the present invention can be applied will be described in detail with reference to FIG.

  The composite pressure vessel 10 is formed from a liner 12 that defines an internal space 14 for containing gaseous hydrogen. For example, a plastic material is used for manufacturing the liner 12. The liner 12 is surrounded by a coating 16, which is formed from a fiber composite material such as a resin-impregnated carbon fiber and gives the pressure vessel 10 the necessary shape stability. The manufacturing materials for the liner 12 and the coating 16 are not, however, limited to these materials described above. Similarly, the present invention provides for a special shape of the coating 16 (eg, axial and / or tangential and / or winding direction of the fiber adjusted to an angle) and a special thickness of the liner 12 and the coating 16. It is not limited to dimensions. Since the basic structure of the pressure vessel is already known to the person skilled in the art from the prior art, the person skilled in the art can determine the embodiments corresponding to the respective requirements (for example gas type, pressure, application area, etc.) without any problems. Could be designed.

  In the embodiment of FIG. 1, the pressure vessel 10 has two neck portions (upper or lower in the figure), each provided with an opening 22, which is sealed by a neckpiece 18 or 20. Has been blocked or blocked. A valve 24 is preferably arranged in the opening 22 (upper part in the figure) that is not blocked by the neckpiece. The invention is not limited to a special embodiment of the neckpieces 18, 20. Furthermore, a cap for assisting and stabilizing the pressure vessel 10 may be provided at both neck portions of the pressure vessel 10. Alternatively, the pressure vessel 10 can optionally be formed using two openings 22 to which valves 24 are attached. Further, the shape of the pressure vessel 10 is not limited to the one having the two neck portions shown in FIG.

  Further, a coating 26 is applied to the outside of the coating 16, for example, in the form of a lacquer coat.

  Next, based on FIGS. 2 and 3, the problem of hydrogen flowing out from the conventional compression vessel will be described.

  The internal space 14 of the pressure vessel 10 stores gaseous hydrogen, for example, at a pressure of about 700 bar. Over time, a certain amount of hydrogen will be dissipated from the liner 12 (see arrow 28 in FIG. 2). Most of the gaseous hydrogen passing through the liner 12 collects in a pocket 30 between the liner 12 and the coating 16. A small amount of hydrogen probably reaches the periphery through the pores or holes 32 of the coating 16. Macroscopically, since the coating 16 is in contact with the liner 12 in the same plane, when the interior space 14 of the liner 12 is at a high pressure, the accumulated hydrogen freely enters a small hole 32 that is only slightly in the coating. That is strongly disturbed.

  When the pressure vessel 10 is used for a long period of time, hydrogen accumulates in the pocket 30 between the liner 12 and the coating 16 to increase the pressure, and in an extreme case, the liner 12 may be deformed.

  When the pressure vessel 10 is disposed of after a long period of use or when a certain amount of hydrogen is withdrawn from the interior space 14, the pressure in the interior space 14 decreases, so that the pressure between the liner 12 and the coating 16 is reduced. The positive pressure is generated by the hydrogen accumulated in the pockets 30. This positive pressure has the effect of separating the liner 12 from the inside of the coating 16 as shown in FIG. 3 and can also cause deformation of the liner 12. This separation (see the double arrow in FIG. 3) creates a gaseous hydrogen flow path from the pocket 30 to the pore / hole 32 and further to the outside of the coating 16, so that the hydrogen passing through the liner 12 is transferred to the pressure vessel 10 Can leak out.

  In this way, when the pressure vessel 10 is disposed after a long period of use, hydrogen released through the liner 12 flows out from the pressure vessel 10 at a relatively high rate.

  In order to prevent danger to the surroundings due to hydrogen flowing out of the pressure vessel 10 at a high rate, when the pressure vessel 10 is used for a long period of time according to the present invention, the above pressure increase between the liner 12 and the coating 16 is prevented. Proposed to do. For this purpose, various measures are implemented in the present invention.

  A first embodiment of a pressure vessel according to the present invention will be described with reference to FIGS.

  Like the conventional pressure vessel, the pressure vessel 10 of this embodiment is formed of a liner 12 that defines an internal space 14 that stores gaseous hydrogen, and a coating 16 that surrounds the liner 12. Even in the structure of the pressure vessel 10, when the service period is long, a small amount of hydrogen is diffused through the liner 12 (see the arrow 28 in FIG. 4) because the internal space 14 is at a high pressure. Collect in a pocket 30 between 12 and the coating 16.

  Compared to the conventional composite pressure vessel described above, in the case of the pressure vessel 10 of the present embodiment, the coating is formed at least partially gas-permeable. For this purpose, the coating 16 is formed to be porous, for example. As an additional or alternative method, holes 34 are provided at specific locations in the coating 16, and these holes are connected from the inside of the coating 16 to the outside thereof. By this method, gaseous hydrogen passing through the liner 12 is continuously discharged from the coating 16 to the outside at a low rate. Compared to when hydrogen is suddenly released at a high rate, the risk that the pressure vessel 10 brings to the surroundings due to the gaseous hydrogen coming out is clearly reduced.

  Even in this case, when the pressure vessel 10 is disposed, even if the liner 12 is somewhat peeled off from the covering 16 and a flow path is generated between the pockets 30, as shown in FIG. In addition, since the hydrogen has already flowed out of the coating 16 evenly, there is no significant increase in pressure between the liner 12 and the coating 16, so that a large amount of hydrogen is not released in this state.

  The coating 16 is at least partially formed to be gas permeable. However, in a preferred embodiment of the invention, the coating is formed to be gas permeable substantially throughout the coating.

  As shown in FIG. 1, if the coating 16 is coated with a lacquer coat 26 or the like, of course in this embodiment, the lacquer coat 26 must also be gas permeable. This corresponds at least to the portion where the coating 16 is formed to be gas permeable.

  For example, the porous coating 16 can be formed as follows. The coating 16 substantially consists of a fiber composite material formed of, for example, carbon fibers that generate the compressive strength of the coating itself and a resin for bonding the carbon fibers. This resin needs to be at least partially porous. Nevertheless, of course, the strength and pressure stability of the entire coating 16 must be guaranteed. The resin used for bonding does not contribute to the pressure stability of the pressure vessel 10, but the bonding of carbon fibers is a decisive factor.

  For the production of the porous coating 16, for example, a resin that forms a sufficient number of microcracks due to strong internal stress during curing is used. However, these microcracks must not cause complete failure of the coating 16. In addition, these microcracks are essential for expelling hydrogen to the periphery, so a connection must be made through the entire coating 16.

  Similar specifications apply to the outer lacquer coat 26 provided as necessary. This lacquer coat can also be produced according to the method described above and must meet the same conditions for hydrogen emissions.

  Installing a sufficient number of suitable holes 34 at predesignated locations does not require detailed description. In principle, any method can be used.

  Of course, the gas permeability of the coating 16 depends on the gas in the internal space 14 of the pressure vessel 10. Depending on the type of gaseous medium stored in the pressure vessel 10, it is necessary to adapt the gas permeation characteristics, ie the pores and / or the pores 34, etc.

A second embodiment of the composite pressure vessel according to the present invention will be described in detail with reference to FIG.

Like the conventional pressure vessel, the pressure vessel 10 of this embodiment is formed of a liner 12 that defines an internal space 14 that stores gaseous hydrogen, and a coating 16 that surrounds the liner 12. Even in the structure of the pressure vessel 10, due to the high pressure in the internal space 14, a small amount of hydrogen diffuses through the liner 12 when the service period is long.

  Compared to the conventional composite pressure vessel described above, in the case of the pressure vessel 10 of the embodiment according to FIG. 6, an intermediate layer 36 through which gas passes is provided between the liner 12 and the coating 16. For example, the intermediate layer 36 is connected to the outside of the coating 16, that is, the periphery of the pressure vessel 10 at the neck portion (upper and lower sides in FIG. 6) of the pressure vessel 10. By this method, gaseous hydrogen passing through the liner 12 is continuously discharged from the intermediate layer 36 to the periphery at a low rate. Compared to when hydrogen is suddenly released at a high rate, the risk that the pressure vessel 10 brings to the surroundings due to the gaseous hydrogen coming out is clearly reduced.

  The coating 16 itself can be formed as airtight as a conventional pressure vessel. Alternatively, the coating 26 can be applied, for example in the form of a lacquer coat. The intermediate layer 36 provided according to the present invention is formed, for example, at least partially porous.

  Further, the gas processing means 38 is arranged at the connection portion between the intermediate layer 36 and the periphery of the pressure vessel 10, that is, in the embodiment of FIG. 6, the neck portion of the pressure vessel 10 having the filling opening or the discharge opening 22. . The gas processing means 38 is formed, for example, by impregnating the porous intermediate layer 36 with a corresponding gas processing agent.

  In the case where gaseous hydrogen is stored in the internal space 14 of the pressure vessel 10, the gas processing means 38 preferably includes an oxidation catalytic converter that oxidizes hydrogen into water at the aforementioned connecting portion. The water generated in this way flows out in the form of liquid or vapor by the hydrogen that subsequently flows through the intermediate layer 36. In this embodiment, the danger to the periphery of the pressure vessel 10 due to the flowing hydrogen is completely prevented.

  The oxidation-catalyzed part 38 of the porous intermediate layer 36 is attached only to the outlet part of the intermediate layer 36 to the periphery of the pressure vessel 10, and in this part without this gas treatment means 38, hydrogen Is coming out. Catalytic portion 38 can be produced, for example, by impregnating porous intermediate layer 36 with a liquid containing catalyst in dissolved or suspended form. By post-treating the impregnated portion 38 with heat, the activity of the catalyst can be further enhanced. If a porous intermediate layer 36 is already mounted on the liner 12, such thermal post-treatment should only be performed in a temperature range where the liner 12 is not damaged.

  Since the oxidation catalytic converter 38 is disposed at a connection portion of a normal outlet that discharges hydrogen to the periphery, sufficient supply of oxygen necessary for catalytic oxidation is guaranteed.

  Since the hydrogen passing through the liner 12 is always discharged, even if the pressure vessel 10 is disposed of and the pressure in the internal space 14 decreases, no positive pressure is generated between the liner 12 and the coating 16. Therefore, nonuniform deformation of the liner 12 is prevented.

  At this time, in the method of attaching the porous intermediate layer 36 on the liner 12, the hydrogen passing through the liner 12 is discharged toward the gas processing means 38 in both the process and the process of attaching the coating 16 next. Thus, it must be ensured that hydrogen can pass freely through the porous intermediate layer 36 to the catalytic component 38.

  The same applies to the oxidation catalytic converter 38 manufactured by impregnation or the like, which is attached to the unsealed end of the porous intermediate layer 36, so that the water generated in the catalytic converter 38 is surrounded by the surroundings. It can be discharged without obstacles.

Claims (7)

Pressurized comprising a liner (12) defining an interior space (14) containing a gaseous medium, and a coating (16) surrounding the liner (12) and geometrically stabilizing the pressure vessel (10). A pressure vessel (10) for storing a gaseous medium,
A gas permeable intermediate layer (36) is provided between the liner (12) and the coating (16), the intermediate layer being connected to the outside of the coating (16) in at least one location; A pressure vessel characterized in that gas passing through the liner (12) can escape from the pressure vessel (10) through the intermediate layer (36).   2. Pressure vessel according to claim 1, characterized in that the intermediate layer (36) is at least partly made porous.   3. Pressure vessel according to claim 1 or 2, characterized in that a gas treatment means (38) is arranged at the connecting part between the intermediate layer (36) and the outside of the coating (16).   The pressure vessel according to claim 3, characterized in that the gas treatment means (38) comprises an oxidation catalytic converter.   The pressure vessel according to claim 3 or 4, wherein the gas processing means (38) is formed by impregnating the intermediate layer (36) with a gas processing agent.   6. Pressure according to claims 1-5, characterized in that the connecting part between the intermediate layer (36) and the outside of the covering (16) is provided at the neck part of the pressure vessel (10). container.   The connecting portion between the intermediate layer (36) and the outer side of the coating (16) is provided in the filling opening and / or the discharge opening (22) of the pressure vessel (10). The pressure vessel according to claim 1.

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