KR102598547B1 - Pressure vessel and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a pressure vessel and a method of manufacturing the same. A method of manufacturing a pressure vessel that increases the internal volume of the pressure vessel and improves its weight efficiency by removing the solid liner that conventionally served as a support during carbon fiber winding, and a manufacturing method accordingly. It is about a pressure vessel.

Description

Pressure vessel and method for manufacturing the pressure vessel {Pressure vessel and method for manufacturing the same}

The present invention relates to a pressure vessel and a manufacturing method thereof, and more specifically, to a high-pressure vessel storing high-pressure gas and a manufacturing method for manufacturing the high-pressure vessel.

Gas storage containers are needed to store various types of gas, such as hydrogen, nitrogen, and natural gas, and to discharge the stored gas as needed. In particular, gas needs to be stored at high pressure because the storage density in the container is low, and pressure containers are essential for use in such high-pressure environments.

For example, alternative fuel gas vehicles (fuel cell vehicles or compressed natural gas vehicles) have different storage system structures depending on the storage method of the fuel gas, and currently, considering the unit cost, weight, and simplicity of the storage system, the storage system is used in the form of compressed gas. The storage method is attracting attention. However, gaseous fuel has a low energy storage density, so to secure more driving distance, the storage amount must be increased or the storage pressure must be increased. In the case of automobiles, the space for mounting a gas storage system is limited, so increasing the size of the storage tank is limited, so safely storing higher pressure gas is the key to tank technology.

In the case of composite tanks among fuel gas storage tanks, the outer shell is reinforced with fiber-reinforced composite materials with high specific strength and specific rigidity to handle the internal pressure caused by compressed gas, and a liner is inserted inside to maintain gas tightness. do. Fuel gas storage tanks are divided into types depending on the material of the liner. Tanks with metal liners such as aluminum are classified as Type 3, and tanks with high-density polymer liners are classified as Type 4. . In the case of Type 3, the stability is relatively high, but it is expensive and has poor fatigue resistance, while the Type 4 tank is cheaper than Type 3 and has excellent fatigue resistance, but has hydrogen leakage and permeation resistance. There are safety issues such as poor performance. Currently, Type 4, which winds a carbon fiber composite material on a support made of a combination of an aluminum boss and a plastic liner, is the most advanced type of hydrogen tank.

Pressure containers such as Type 4 are made of expensive carbon fiber, and in order to withstand the pressure inside the container, they are manufactured by winding and stacking plastic carbon fiber composites on a plastic liner.

Meanwhile, the efficiency of a hydrogen tank is determined by the amount of hydrogen stored relative to the weight of the tank. Therefore, in order to improve hydrogen tank efficiency and vehicle fuel efficiency, it is necessary to increase the internal volume while reducing the tank weight.

Document 1: US Patent Publication No. 2002-0088806 Document 2: Japanese Patent Publication No. 2004-176898

The present invention was devised to solve the above problems. In the present invention, a pressure vessel is made of solid and increases the internal volume of the pressure vessel and improves its weight efficiency by removing the liner that functioned as a support during carbon fiber winding. The purpose is to provide a manufacturing method and a pressure vessel manufactured accordingly.

In order to achieve the above object, a preferred embodiment of the present invention includes the steps of preparing a temporary support in which the support layer is fixed by inserting a fixing pin into a fastening groove on the inner surface of the boss portion where the inlet flow path is formed; Injecting gas through the boss part inlet flow path to expand the temporary support and blocking the boss part inlet flow path to provide an expanded temporary support; forming an outer layer outside the temporary support; and removing the support layer. It provides a method of manufacturing a pressure vessel including.

In addition, the temporary support is located outside the support layer and further includes an airtight maintaining film that is fixed to the fastening groove of the boss portion together with the support layer by the fixing pin. .

In addition, the step of forming the outer layer provides a method of manufacturing a pressure vessel, characterized in that it is a step of forming a composite layer by winding a composite material on the outside of the temporary support.

In addition, in the step of removing the support layer, a method of manufacturing a pressure vessel is provided, characterized in that the support layer is removed by opening the boss portion inlet passage and pulling out the support layer through the boss portion inlet passage.

In addition, in the step of removing the support layer, a method of manufacturing a pressure vessel is provided, wherein the support layer is removed by pulling a separation ring connected to the fixing pin with a metal wire.

In addition, the step of forming the outer layer is a step of forming a composite layer by winding composite fibers impregnated with a thermosetting resin around the outside of the temporary support, and the step of removing the support layer is a step of forming the composite layer by curing the composite layer and forming the airtightness-retaining film and the A method of manufacturing a pressure vessel is provided, which is performed after integration.

In addition, in the step of preparing the temporary support, the process of positioning the airtightness-maintaining film around the fastening groove, inserting a guide member into the fastening groove, and then fixing the support layer and the airtightness-maintaining film with the fixing pin. A method for manufacturing a pressure vessel comprising:

In addition, in the step of preparing the temporary support, a fixing pin equipped with a shoulder bracket having a shape matching the shape of the inner surface of the boss is inserted into the fastening groove to fix the support layer. provides.

In addition, a method of manufacturing a pressure vessel is provided, wherein the support layer is made of a deformable material that can expand to have a preset external shape or shrink by expelling internal gas.

In addition, a pressure vessel manufactured by the pressure vessel manufacturing method described above, comprising: a boss portion in which an inlet flow path is formed; and an outer layer formed integrally with the boss portion, wherein a fastening groove is formed on the inner surface of the boss portion so that a temporary support including a fixing pin to which the support layer is fixed can be fastened. .

In addition, the support layer provides a pressure vessel, wherein the support layer can be removed through the boss portion inlet passage as the fixing pin is separated from the fastening groove.

In addition, a pressure vessel is provided, wherein the outer layer is a composite layer formed by winding a composite material.

In addition, a pressure vessel is provided, which is located inside the composite layer and further includes an airtight maintaining film formed integrally with the composite layer.

Meanwhile, according to the present invention, a temporary support used in a process for manufacturing a pressure vessel includes a fixing pin configured to be inserted into a fastening groove on the inner surface of the boss portion where the inlet flow path is formed; a support layer integrally fixed to the fixing pin; and an airtight maintaining film located on the outside of the support layer and fixed to the fastening groove of the boss portion together with the support layer by the fixing pin, wherein the support layer has a preset external shape as air is injected into the inside. It is made of a deformable material that can expand or contract by expelling internal gas, and provides a temporary support on which the support layer is removed through the inlet passage of the boss portion after the outer layer of the pressure vessel is formed.

According to the present invention, the skirt (wing) portion of the metal boss portion of the pressure vessel can be reduced and a pressure vessel without a plastic liner can be manufactured, so the hydrogen storage capacity of the pressure vessel is increased and the weight of the pressure vessel is reduced. It works.

In addition, according to the present invention, hydrogen weight efficiency can be improved by increasing the internal volume and reducing the weight of the pressure vessel, and has the effect of improving vehicle mileage and vehicle fuel efficiency per charge.

Additionally, by removing the plastic liner, there is an effect of preventing buckling of the plastic liner, which is a chronic problem of type 4 containers including conventional plastic liners.

Figure 1 shows a cross section of a typical pressure vessel,
Figure 2 shows the support structure of the fiber composite material used in the method of manufacturing a pressure vessel according to the present invention,
Figure 3 shows a pressure vessel manufactured according to the pressure vessel manufacturing method according to the present invention, before the support layer inside the vessel is removed;
Figure 4 is an enlarged view of the area around the metal boss portion of the pressure vessel of Figure 3;
Figure 5 is a pressure vessel manufactured according to the method of manufacturing a pressure vessel according to the present invention, showing the pressure vessel after the support layer inside the vessel has been removed;
Figure 6 is an enlarged view of the area around the metal boss portion of the pressure vessel of Figure 5;
Figure 7 shows an example in which a temporary support layer guide is formed on a fixing pin fastened to a metal boss part,
Figure 8 shows a method of manufacturing a pressure vessel according to a preferred embodiment of the present invention.

The present invention relates to a pressure vessel that stores high-pressure gas and a method of manufacturing the same, and to a pressure vessel that ensures airtightness so that the high-pressure gas stored in the vessel does not leak and a method of manufacturing the same. In particular, the present invention relates to a method of manufacturing a pressure vessel in which the area around the boss, which is one of the weak parts of the vessel, can be strengthened with a fiber composite material.

Regarding pressure vessels, composite materials are used as the material for pressure vessels, and pressure vessels manufactured by stacking composite materials by a winding method may be the target. However, the pressure vessel described as a preferred embodiment of the present invention is not limited to the types of vessels described above, and it is sufficient that a unique support structure capable of supporting the laminated composite material is applied when laminating the composite material. .

Therefore, in this specification, in addition to the structure in which composite materials are laminated by a winding method, structures in which composite materials are laminated in other forms are also applicable. In addition, the present invention describes a composite layer being laminated on the outside of the support layer 220, but if it is supported by the support layer 220, a layer of a material other than the composite layer may be applied.

Accordingly, the present invention is not limited to only the drawings and examples presented as preferred embodiments, and should be construed to encompass various modifications such as those mentioned above.

Hereinafter, with reference to the attached drawings, a method for manufacturing a pressure vessel according to a preferred embodiment of the present invention and a pressure vessel manufactured thereby will be described in detail.

The pressure vessel has a symmetrical structure with respect to the central axis (C) and has a structure in which a dome-shaped structure and a cylinder-shaped structure are formed as one piece. Specifically, as shown in Figure 1, the pressure vessel is composed of a dome part forming a dome shape from the boss part 10 on the central axis, a cylinder part located in the middle area of the pressure vessel, and a conversion part located between the dome part and the cylinder part.

In particular, in the case of the dome portion and the cylinder portion, fiber composite materials are laminated by winding. That is, fibers impregnated with a thermosetting resin such as an epoxy resin are repeatedly wrapped around the outer circumference of the liner 20 to form a fiber composite layer 30 on the liner 20, and the resin is then heat-cured to form the liner 20. A pressure vessel reinforced with a temporary fiber composite material is manufactured. Since the winding method of fiber composites is already a known technology, description of this winding method is omitted in this specification.

Meanwhile, a preferred embodiment of the present invention is characterized in that, unlike the pressure vessel of FIG. 1, a pressure vessel is provided in which the plastic liner coupled to the boss portion 110 is removed. For this purpose, in the present invention, a removable temporary support layer 220 is fixed to the boss portion 110 of the pressure vessel, and the temporary support layer 220 is removed after the fiber composite layer is formed on the outside.

In this regard, Figure 2 shows a support structure for this removable fiber composite layer. Additionally, FIG. 3 shows the pressure vessel before the support layer 220 is removed, and FIG. 5 shows the pressure vessel after the support layer 220 is removed.

Referring to FIG. 2, in the method of manufacturing a pressure vessel according to this embodiment, a fastening groove is formed on the inner surface of the boss portion 110, and a fixing pin 210 formed integrally with the support layer 220 is inserted into this fastening groove. It is characterized by forming a composite layer support structure.

This support layer 220 functions as a support for winding the composite material, and must be configured so that it can be removed after the composite layer manufacturing of the pressure vessel is completed. Therefore, the support layer 220 should not have a fixed outer shape, but should be configured so that its outer shape can be changed as air is injected into or taken out.

At this time, when air is injected into the support layer 220, it has an external shape corresponding to the shape of a preset pressure vessel, and when the air inside is removed, it shrinks and flows through the inlet flow path of the boss portion 110. It is desirable to be configured so that it can be taken out to the outside. Therefore, the support layer 220 may be made of a deformable material such as vinyl or cloth. In addition, the support layer 220 must be configured to substantially block the flow of gas, so that when the inlet flow path of the boss portion 110 is blocked, the external shape of the support layer 220 can be maintained as is. Therefore, according to a preferred embodiment of the present invention, a fabric whose surface is treated to make it non-breathable can be used.

Accordingly, the support layer 220 is made of a deformable material that can expand to have a preset external shape as air is injected into the inside or shrink by expelling the internal gas, and the outer layer 120 of the pressure vessel is formed on the outside. After it is formed, it can be removed through the inlet flow path of the boss portion 110.

Meanwhile, gas is injected into the temporary support to expand it, and then a stopper is installed on the inlet flow path of the boss part 110 to block gas discharge. Accordingly, internal gas emissions are blocked and the temporary support forms a certain external shape, as shown in FIG. 3, and has sufficient strength for the composite material to be wound.

Additionally, FIG. 4 is an enlarged view of the area around the metal boss portion 110 of the pressure vessel of FIG. 3.

As shown in FIG. 4, the fixing pin 210 may be provided in a form that can be press-fitted into the inner fastening groove of the boss portion 110. In addition, the fixing pin 210 may be configured to include a pin portion inserted into the fastening groove and a head portion located outside the fastening groove. Preferably, a separation ring is connected to the head portion through a wire 240. can do.

Therefore, the fixing pin 210 can be effectively removed by pulling the separation ring through the inlet passage of the boss portion 110. In this regard, a separation ring and/or a mechanism for pulling the wire 240 may be used, or a method in which the worker directly finds and pulls the wire 240 by hand may be applied.

In addition, the fastening groove of the boss part 110 may be formed on the inner surface of the boss part 110, more preferably on the inner surface bent and extending from the inlet passage, to facilitate removal of the fixing pin 210. Additionally, to make it easier to remove the fixing pin 210, the fastening groove may be formed to be inclined at a certain angle compared to the inlet passage.

As shown in Figure 4, the support layer 220 may be integrally fixed to the bottom of the head of the fixing pin 210. In this way, when the support layer 220 is integrally fixed to the bottom of the head portion, the support layer 220 can be easily removed from the boss portion 110 by pulling the fixing pin 210. To this end, the support layer 220 may be adhered to the bottom of the head of the fixing pin 210.

In addition, the temporary support is located outside the support layer 220, and the airtightness maintaining film 230 is fixed to the fastening groove of the boss portion 110 together with the support layer 220 by the fixing pin 210. ) can be configured to further include. This airtight retention film 230 functions to prevent hydrogen from being discharged to the outside, which is a function of existing plastic liners.

That is, when the outer layer 120 is formed with a single composite layer, a problem may occur in which a trace amount of hydrogen gas may periodically leak through the composite layer. In the present invention, in order to improve this problem, the airtightness maintaining film 230 including a polymer thin film is configured to be applied to the temporary support.

In general, the outer layer 120 of the pressure vessel is formed by winding composite fibers impregnated with a thermosetting resin. When the wound composite layer is cured, the airtight film 230 becomes integrated with the composite layer. Therefore, in the temporary support including the airtightness maintaining film 230, when the fixing pin 210 is removed from the fastening groove of the boss portion 110, as shown in FIG. 5, the airtightness maintaining film 230 is attached to the composite layer. While it remains attached, only the support layer 220 falls off. For reference, reference numeral 130 is a fixing device for fixing the wound composite material step by step when winding the composite material, and the fixing device may have a nut structure fastened to the inlet screw structure of the boss portion 110.

In addition, when applying this airtightness-retaining film 230, a guide member 250 is used to primarily fix the airtightness-retaining film 230, while allowing the airtightness-retaining film 230 to be sufficiently seated in the fastening groove. It can be. This guide member 250 has a hollow structure that can be accurately fitted into the fastening groove, and may preferably have a cylindrical hollow structure.

Therefore, in manufacturing the temporary support, the airtightness-retaining film 230 is positioned around the fastening groove, and then the guide member 250 is inserted into the fastening groove, and then the support layer is secured with the fixing pin 210. A process of fixing (220) and the airtightness maintaining film 230 may be performed.

In addition, a fixing pin 210 is inserted into the guide member 250 as shown in FIG. 4, and even if the fixing pin 210 is removed, the guide member 250 can be configured to remain in the fastening groove as shown in FIG. 6. You can. This can be implemented by configuring the interference fit between the fastening groove and the guide member 250 to be larger than the interference fit between the fixing pin 210 and the guide member 250.

In relation to this, Figure 6 shows after the fixing pin 210 and the support layer 220 are removed, and only the guide member 250 and the airtight maintaining film 230 remain inside the boss portion 110.

In addition, as another embodiment of the present invention, as shown in FIG. 7, the fixing pin 210 is inserted into the fastening groove of the boss portion 110 while the shoulder bracket 260 is mounted on the fixing pin 210. By doing so, the support layer 220 or the support layer 220 and the airtightness maintaining film 230 may be fixed integrally. In this case, since the shoulder bracket 260 is designed to exactly match the inner shape of the metal boss portion 110, when the support layer 220 is located between the shoulder bracket 260 and the boss portion 110, the support layer ( Since the shape of 220 completely matches the shape of the boss portion 110, the outer layer 120 can be implemented to accurately engage the shape of the boss portion 110.

In this regard, since the support layer 220 can be removed together with the fixing pin 210 only if it is formed integrally with the fixing pin 210, the shoulder bracket 260 made of metal is integrated with the bottom of the head of the fixing pin 210. It is preferably formed so that the support layer 220 is adhered to one surface.

A specific method of manufacturing a pressure vessel using a temporary support having such a configuration is shown in FIG. 8.

As shown in FIG. 8, according to a preferred embodiment of the present invention, a step of preparing a temporary support in which the support layer is fixed by inserting a fixing pin into a fastening groove on the inner surface of the boss portion where the inlet flow path is formed is performed. (Figure 8(a))

Thereafter, gas is injected through the boss portion inlet passage to expand the temporary support, and the boss portion inlet passage is blocked to provide an expanded temporary support. (Figure 8(b))

An outer layer is formed on the outside of the expanded temporary support as the composite material is wound. (FIG. 8(c)) Afterwards, the composite fixing device is installed (FIG. 8(d)) and the composite winding is repeated (FIG. 8(e)) to produce a pressure vessel with the winding completed. (Figure 8(f))

In this state, since the temporary support is still located inside, as shown in Figure 8(g), pull the wire to separate the fixing pin, then remove the temporary support through the boss inlet passage, and complete the production of the pressure vessel. do.

When manufacturing a pressure vessel using the above pressure vessel manufacturing method, the liner inside the pressure vessel can be removed, thereby increasing the internal volume of the pressure vessel and reducing the weight of the pressure vessel. In addition, when applying a gas-tight sealing film made of a polymer material, the air-tight sealing film is integrally attached to the composite layer by the resin impregnated with carbon fiber during the production of the pressure vessel, so even if physical contraction and expansion of the pressure vessel occurs, the buckling phenomenon occurs. This will not occur.

Although the present invention has been described with reference to preferred embodiments, those skilled in the art will understand that modifications and changes can be made to elements of the present invention without departing from the scope of the present invention. Additionally, many changes may be made to special circumstances or materials without departing from the essential scope of the present invention. Therefore, the present invention is not limited to the detailed description of the preferred embodiments of the present invention, but will include all embodiments within the scope of the appended claims.

110: Boss part 120: External layer (composite layer)
210: fixing pin 220: support layer
230: hermetic membrane 240: wire
241: Separation ring 250: Guide member
260: Shoulder bracket

Claims (15)

Preparing a temporary support that secures the support layer by inserting a fixing pin into a fastening groove on the inner surface of the boss portion where the inlet flow path is formed;
Injecting gas through the boss part inlet flow path to expand the temporary support and blocking the boss part inlet flow path to provide an expanded temporary support;
forming an outer layer outside the temporary support; and
Comprising: removing the support layer,
The temporary support is located outside the support layer and further includes an airtight maintaining film that is fixed to the fastening groove of the boss portion together with the support layer by the fixing pin.
delete In claim 1,
The step of forming the outer layer is a step of forming a composite layer by winding a composite material on the outside of the temporary support.
In claim 1,
In the step of removing the support layer, the boss portion inlet passage is opened, and the support layer is removed through the boss portion inlet passage.
In claim 1,
In the step of removing the support layer, a method of manufacturing a pressure vessel, characterized in that the support layer is removed by pulling a separation ring connected to the fixing pin with a metal wire.
In claim 1,
The step of forming the outer layer is a step of forming a composite layer by winding composite fibers impregnated with a thermosetting resin around the outside of the temporary support,
A method of manufacturing a pressure vessel, characterized in that the step of removing the support layer is performed after the composite layer is cured and integrated with the airtightness maintaining film.
In claim 1,
In the step of preparing the temporary support, positioning the airtightness-retaining film around the fastening groove, inserting a guide member into the fastening groove, and fixing the support layer and the airtightness-retaining film with the fixing pin. A method of manufacturing a pressure vessel, characterized in that.
In claim 1,
In the step of preparing the temporary support, a fixing pin equipped with a shoulder bracket having a shape matching the shape of the inner surface of the boss is inserted into the fastening groove to fix the support layer.
In claim 1,
A method of manufacturing a pressure vessel, characterized in that the support layer is made of a deformable material that can expand to have a preset external shape or shrink by expelling internal gas.
A pressure vessel manufactured by the method for manufacturing a pressure vessel according to any one of claims 1 and 3 to 9.
A boss portion with an inlet flow path formed;
It includes an outer layer formed integrally with the boss portion,
A fastening groove is formed on the inner surface of the boss portion so that a temporary support including a fixing pin to which the support layer is fixed can be fastened,
The outer layer is a composite layer formed by winding a composite material,
A pressure vessel located inside the composite layer and further comprising an airtight maintaining film formed integrally with the composite layer.
In claim 11,
A pressure vessel, characterized in that the support layer can be removed through the boss portion inlet passage as the fixing pin is separated from the fastening groove.
delete delete A fixing pin configured to be inserted into a fastening groove on the inner surface of the boss portion where the inlet flow path is formed; a support layer integrally fixed to the fixing pin; and an airtightness-retaining film located outside the support layer and fixed to the fastening groove of the boss portion together with the support layer by the fixing pin,
The support layer is made of a deformable material that can expand to have a preset external shape as air is injected into the interior, or shrink by expelling internal gas,
A temporary support in which the support layer is removed through the inlet passage of the boss portion after the outer layer of the pressure vessel is formed.

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