KR20200066481A - Manufacturing method of pressure vessel and pressure vessel manufactured by the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a pressure vessel, comprising the steps of: (1) manufacturing a liner comprising plastic composed of a crystalline region and an amorphous region, and having an interior receiving space in which a high pressure fluid is accommodated; (2) forming surface irregularities by removing the amorphous region of the plastic from the surface of the liner; and (3) forming a fiber reinforcement layer on the outside of the liner on which the surface irregularities are formed. The present invention also relates to a pressure vessel manufactured thereby.

Description

Manufacturing method of pressure vessel and pressure vessel manufactured accordingly{MANUFACTURING METHOD OF PRESSURE VESSEL AND PRESSURE VESSEL MANUFACTURED BY THE SAME}

The present invention relates to a method for manufacturing a pressure vessel and a pressure vessel prepared accordingly, specifically comprising removing the amorphous region of the plastic from the surface of the liner comprising the plastic composed of the crystalline region and the amorphous region. It relates to a method for manufacturing a pressure vessel equipped with a liner having and a pressure vessel prepared accordingly.

In general, pressure vessels are designed to safely store various high pressure fluids, including liquefied petroleum gas (LPG), compressed natural gas (CNG), light hydrocarbons (methane, propane, butane) and hydrogen gas.

These pressure vessels are generally composed of an outer composite layer supporting most of the inner pressure and a liner providing an inner mold, and are traditionally made of metal. However, the pressure vessel made of the conventional metallic liner has a problem that the weight of the metal is heavy due to the characteristics of the metal and is very weak to corrosion, and the manufacturing cost is high.

Accordingly, the use of pressure vessels in which reinforcing fibers such as carbon fibers or glass fibers are wound or laminated on the outside of a plastic liner is increasing.

For example, Patent Document 1 (Korean Patent Registration No. 10-0738723) discloses a pressure vessel made of a high-density polyethylene (HDPE) liner in which reinforcing fibers such as carbon fibers or glass fibers are wound. The HDPE liner has the advantage of being lightweight and excellent in corrosion resistance compared to the metallic liner. However, since the reinforcing fibers are not adhered to the liner by the winding, a gap exists between them, and a fluid passing through the liner may be introduced into the gap. The fluid introduced in this way may cause deformation of the pressure vessel. In addition, when the fluid in the gap diffuses to the outside, an unpleasant odor is caused, and an explosion possibility is inherent.

Moreover, since the HDPE is a polymer that is permeable to a fluid, such as LPG, the pressure vessel known in Patent Literature 1 is limited in maintaining the leak rate of the fluid below an allowable value. Normally, the allowable leak rate of the pressure vessel is 0.5 to 1 g/day for LPG ( ₂₄ L LPG cylinder condition at 20 bar pressure and 50°C), 6 cc/l/hr for nitrogen (N ₂ ) gas, and methane (CH ₄ ) It is about 0.25 cc/l/hr for gas and 46 cc/l/hr for hydrogen (H ₂ ) gas, and leak rates above this allowed leak rate are not allowed in terms of design, regulation and consumption.

As a method for solving this problem, Patent Document 2 (Domestic Patent Publication No. 10-1855874) is a liner of a thermoplastic resin capable of filling and discharging fluid; A reinforcing layer formed on the outside of the liner by reinforcing fibers impregnated with a first synthetic resin; And an adhesive layer provided between the liner and the reinforcing layer by a second synthetic resin. In addition, Patent Document 2, in order to improve the adhesion, the surface of the outer peripheral surface of the liner to form irregularities, the surface treatment using a processing method such as plasma treatment or sandblasting treatment. According to Patent Document 2, the adhesion between the liner and the reinforcing layer is improved, and there is almost no gap between them, so that the fluid leak rate can be maintained below the allowable value. However, such a method requires disadvantages of expensive equipment and an increase in utility cost, which is disadvantageous in economic efficiency.

Accordingly, there is a need for research on a method for manufacturing a pressure vessel having a liner having surface irregularities formed in an economical manner.

KR 100738723 B1 KR 101855874 B1

The present invention is to solve the above problems, and for the purpose of providing a method of manufacturing a pressure vessel comprising the step of removing the amorphous region of the plastic from the surface of the liner comprising a plastic consisting of a crystalline region and an amorphous region do.

Another object of the present invention is to provide a pressure vessel provided with a liner having a surface irregularity according to the above manufacturing method.

One embodiment of the present invention, (1) a high-pressure fluid is provided with an inner receiving space, a step of manufacturing a liner comprising a plastic consisting of a crystalline region and an amorphous region; (2) removing the amorphous region of plastic from the surface of the liner to form surface irregularities; And (3) forming a fiber reinforcement layer outside the liner on which the surface irregularities are formed.

Another embodiment of the present invention provides a pressure vessel manufactured according to the above manufacturing method.

According to the pressure vessel manufacturing method of the present invention, by including the step of removing the amorphous region of the plastic from the surface of the liner comprising a plastic consisting of a crystalline region and an amorphous region, it is possible to manufacture a pressure vessel provided with a liner having a surface irregularity. .

According to the present invention, since the pressure vessel provided with the liner having the surface irregularities can be manufactured by the simple method as described above, the processing method is simple, expensive equipment is unnecessary, and the utility cost can be reduced, which is very economical.

In addition, by removing the amorphous region, a layer containing only plastic made of crystalline region may be formed on the surface of the liner, and accordingly, the high pressure fluid filled inside the liner is blocked by the layer composed of only crystalline plastic to reduce the leak rate. Can be.

In addition, when an adhesive layer is further interposed between the liner and the fiber reinforcement layer, the liner and the fiber reinforcement layer may be hermetically attached by the adhesive layer. Accordingly, a gap between the liner and the fiber reinforcement layer does not occur, so that the problem of high-pressure fluid flowing into the gap may be blocked. In addition, the high-pressure fluid filled in the liner is completely blocked by the adhesive layer and the fiber reinforcement layer, so that leakage of gas may be fundamentally limited, and accordingly, a pressure vessel having excellent safety may be provided. Moreover, the adhesive layer between the liner and the fiber reinforcement layer is improved by the adhesive layer, thereby providing a pressure vessel with excellent durability, and has an effect of prolonging product life.

1 is a partial cross-sectional view of a pressure vessel according to an exemplary embodiment of the present invention.
2 is a cut-away perspective view of a pressure vessel according to an exemplary embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The present invention can be applied to various changes and can have various forms, and the embodiments are described in detail in the text. However, it is not intended to limit the present invention to a specific disclosure form, it should be understood to include all modifications, equivalents, or substitutes included in the spirit and scope of the present invention. In the present invention, terms referring to a component are used for the purpose of distinguishing one component from other components. The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

One embodiment of the present invention, (1) a high-pressure fluid is provided with an inner receiving space, a step of manufacturing a liner comprising a plastic consisting of a crystalline region and an amorphous region; (2) removing the amorphous region of plastic from the surface of the liner to form surface irregularities; And (3) forming a fiber reinforcement layer outside the liner on which the surface irregularities are formed.

In the present specification, the pressure container means a container for storing gas or liquid having a pressure exceeding atmospheric pressure therein. Such a pressure vessel can store various high pressure fluids including liquefied petroleum gas (LPG), compressed natural gas (CNG), light hydrocarbons (methane, propane, butane) and hydrogen gas, and specifically stores hydrogen as fuel. It can be a hydrogen storage tank. The liner constituting the pressure vessel may have a hollow cylindrical or non-cylindrical shape. Specifically, the liner is provided with an internal receiving space having an elliptical cross section in which a high pressure fluid is accommodated, and may be formed in a cylindrical shape.

Hereinafter, one embodiment of the present invention will be described in detail step by step.

(1) Liner manufacturing steps

This step is a step of manufacturing a liner comprising a plastic composed of an crystalline region and an amorphous region, having an interior receiving space in which a high-pressure fluid is accommodated.

As a method of manufacturing the liner, a conventionally known plastic container forming method can be used without limitation. For example, blow molding or injection molding may be used, but is not limited thereto. Specifically, when blow molding is used, the step (1) may include preparing a liner molding from a molten plastic material; And cooling the liner molding. Here, blow molding is a molding technique for obtaining a hollow plastic molded product, and is preformed into a tube by extrusion or injection, and is blown into the mold and blown into the inside to inflate and then cooled and solidified to form a solid material in a specific shape. Is to make

The degree of crystallinity of the plastic material may vary according to a cooling rate in the cooling process of the liner molding. Specifically, the cooling rate may be 15° C./min or more and 25° C./min or less, and in this case, a part of the plastic material constituting the liner molding is crystallized and the rest is not crystallized. Liners comprising plastics composed of crystalline and amorphous regions can be produced.

According to one embodiment of the present invention, the plastic may be selected from the group consisting of polyolefin-based resins, polyamide-based resins, and composite resins thereof, for example, high density polyethylene (HDPE), polyamide (PA6) may be used, but is not limited to this.Liner made of such a plastic material has advantages of being lighter and superior in corrosion resistance compared to a liner made of a metal material.

According to an exemplary embodiment of the present invention, the plastic may be high density polyethylene (HDPE). When used as a liner material, the HDPE is a material that has strong strength, is economical, and is very easy to mold.

(2) Step of forming surface irregularities

This step is a step of forming the surface irregularities by removing the amorphous region of the plastic from the surface of the liner prepared according to step (1). 1 and 2, a partial cross-sectional view and a schematic cut-away perspective view of a pressure vessel including a liner 110 having surface irregularities 113 according to an exemplary embodiment of the present invention are respectively shown.

According to an exemplary embodiment of the present invention, the step (2) may include removing an amorphous region of plastic from the surface of the liner using an acidic solution. Specifically, this step includes applying an acidic solution to the surface of the liner; And removing the amorphous region of the plastic dissolved in the acidic solution from the liner. As the coating method, a conventionally known method can be used without limitation, and for example, a spray injection method, a brush method, or the like can be used, but is not limited thereto. In addition, water, ethanol, and a mixture thereof may be used for the removal of the amorphous region, and a drying step after removal of the amorphous region may be further included. Through this process, when the amorphous region of the plastic is removed, a plurality of grooves may be formed on the surface of the liner 110, and surface irregularities may be formed on the outer peripheral surface of the liner, resulting in a rough surface.

According to an exemplary embodiment of the present invention, the acidic solution may be a metal salt-based acid solution. Specifically, the metal salt-based acid solution may be a chromic acid solution, and the concentration of the chromic acid solution may be 0.1 to 0.3M. When using such an acidic solution, only the amorphous region of the plastic can be effectively removed from the surface of the liner.

(3) Fiber reinforcement layer formation step

This step is a step of forming a fiber reinforcement layer on the outside of the liner on which surface irregularities are formed according to step (2).

According to an exemplary embodiment of the present invention, the fiber reinforcement layer may include at least one reinforcing fiber selected from the group consisting of glass fiber, carbon fiber, and aramid fiber. The fiber reinforcement layer serves to reinforce the liner, and the reinforcement fiber may be formed to surround the outside of the liner.

According to an exemplary embodiment of the present invention, the fiber reinforcement layer may be formed from reinforcing fibers in the form of filaments impregnated with or without impregnation with a thermosetting resin. Here, the filament means continuous fibers, that is, fibers having an infinitely long length compared to the cross-sectional diameter. In addition, when the fiber reinforcement layer is formed, there is no limitation in the winding direction of the fiber filament, and preferably, it can be wound along the length of the liner, and the winding process can be repeatedly performed to form a plurality of layers. 1 shows a state in which the fiber reinforcement layer is wound into one layer according to an exemplary embodiment of the present invention, but is not limited thereto.

According to one embodiment of the present invention, the thermosetting resin may include at least one selected from the group consisting of epoxy resins, polyesters, vinyl esters, phenolic compounds, polyurethanes and polydicyclopentadienes, and specifically As an epoxy resin may be used.

In addition, according to an exemplary embodiment of the present invention, the step of (2) may further include the step of forming an adhesive layer by applying an adhesive to the outer circumferential surface of the liner on which surface irregularities are formed.

According to an exemplary embodiment of the present invention, the adhesive may include at least one selected from the group consisting of epoxy resin, polyester, vinyl ester, phenolic compound, polyurethane and polydicyclopentadiene. As a specific example, the epoxy resin may include, but is not limited to, bisphenol A type epoxy, bisphenol F type epoxy, novolac epoxy, flame retardant epoxy, cyclic aliphatic epoxy and rubber modified epoxy.

The adhesive layer is applied to the outer circumferential surface of the liner where the surface is roughened, that is, the surface is formed by removing the amorphous region of the plastic from the surface of the liner, so that the adhesive force can be increased. Specifically, since an adhesive layer is formed while an adhesive is embedded in the intaglio portion of the irregularities in the application process, the surface area of the liner outer circumferential surface and the adhesive layer is increased, and accordingly, the adhesive force may be increased. Moreover, in the application process, since the adhesive layer is air-tightly adhered to the outer peripheral surface of the liner, there is no space for high-pressure fluid that has passed through the liner, and the adhesive layer blocks the outer peripheral surface of the liner, so that the high-pressure fluid goes outside the pressure vessel It can prevent leakage.

Another embodiment of the present invention provides a pressure vessel manufactured according to the above manufacturing method. Specifically, FIG. 1 is a partial cross-sectional view of a pressure container according to an exemplary embodiment of the present invention, and FIG. 2 is a cut-away perspective view of the pressure container according to an exemplary embodiment of the present invention.

The pressure vessel 100 according to an exemplary embodiment of the present invention includes a plastic material liner 110 having an inner receiving space in which a high pressure fluid is accommodated; and a fiber reinforcement layer 130 surrounding the outside of the liner; The liner 110 may include plastic composed of a crystalline region and an amorphous region, and the outer circumferential surface of the liner 110 may be removed by removing the amorphous region of plastic existing on the surface of the liner 110. The unevenness 113 may have a shape.

As described above, the unevenness 113 is formed on the outer circumferential surface of the liner 110 by the removal of the amorphous plastic present on the surface of the liner 110, and the outer portion of the liner 110 is composed of only a crystalline region A layer 112 (hereinafter referred to as “outer liner layer”) in which plastic is present may be present, and between the outer liner layer 112 and the endothelium of the liner 110 includes plastic composed of a crystalline region and an amorphous region. A layer 112 (hereinafter referred to as "inner liner layer") may be present. When the high-pressure fluid is filled inside the liner 110 having such a structure, the leak rate may be reduced by being blocked by the outer liner layer 112 made of plastic made of a crystalline region. At this time, the thickness of the outer liner layer 112 may be non-uniform.

Meanwhile, an adhesive layer 120 may be further included between the liner 110 and the fiber reinforcement layer 130. Specifically, FIGS. 1 and 2 respectively show a partial cross-sectional view and a schematic cut-away perspective view of a pressure vessel 100 including an adhesive layer 120 according to an exemplary embodiment of the present invention. The specific contents of the adhesive layer 120 include the contents described above. The pressure vessel 100 according to an exemplary embodiment of the present invention illustrated in FIGS. 1 and 2 includes an inner liner layer 111 including plastics in contact with a high-pressure fluid and composed of a crystalline region and an amorphous region; An outer liner layer 112 that is present outside the inner liner layer 111 and is made of plastic made of a crystalline region and has an unevenness 113 shape; An adhesive layer 120 applied outside the outer liner layer 112; And a fiber reinforcement layer 130 formed on the outside of the adhesive layer 120.

As described above, although the present invention has been described by a limited embodiment and drawings, the present invention is not limited by this, and the technical spirit of the present invention and the following will be described by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within an equivalent range of the claims to be described in.

100: pressure vessel
110: liner
111: inner liner layer
112: outer liner layer
113: surface irregularities
120: adhesive layer
130: fiber reinforcement layer

Claims (12)

(1) preparing a liner having an inner receiving space in which a high pressure fluid is accommodated, and comprising a plastic composed of a crystalline region and an amorphous region;
(2) removing the amorphous region of plastic from the surface of the liner to form surface irregularities; And
(3) forming a fiber reinforcement layer on the outside of the liner on which the surface irregularities are formed. The method according to claim 1,
The plastic is characterized in that it is selected from the group consisting of polyolefin-based resins, polyamide-based resins and composite resins thereof, a method for producing a pressure vessel. The method according to claim 1,
The plastic is high density polyethylene (high density polyethylene, HDPE), characterized in that, the pressure vessel manufacturing method. The method according to claim 1,
The step (2) is characterized in that it comprises the step of removing the amorphous region of the plastic from the surface of the liner using an acidic solution, the method of manufacturing a pressure vessel. The method according to claim 4,
Method for producing a pressure vessel, characterized in that the acidic solution is a metal salt-based acid solution. The method according to claim 5,
Method of producing a pressure vessel, characterized in that the metal salt-based acid solution is a chromic acid solution. The method according to claim 1,
The fiber reinforcement layer is characterized in that it comprises at least one reinforcing fiber selected from the group consisting of glass fiber, carbon fiber and aramid fiber, the manufacturing method of the pressure vessel. The method according to claim 7,
The fiber reinforcement layer is characterized in that it is formed from a reinforcing fiber in the form of a filament impregnated with or without impregnating a thermosetting resin, a method of manufacturing a pressure vessel. The method according to claim 8,
The thermosetting resin is characterized in that it comprises at least one member selected from the group consisting of epoxy resins, polyesters, vinyl esters, phenolic compounds, polyurethanes and polydicyclopentadienes, a method for producing a pressure vessel. The method according to claim 1,
The method of manufacturing a pressure vessel further comprising the step of forming an adhesive layer by applying an adhesive to the outer circumferential surface of the liner where the surface irregularities are formed according to the step (2). The method according to claim 10,
The adhesive is characterized in that it comprises at least one member selected from the group consisting of epoxy resins, polyesters, vinyl esters, phenolic compounds, polyurethanes and polydicyclopentadiene, a method for producing a pressure vessel. A pressure vessel manufactured according to the method of any one of claims 1 to 11.

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