JP2022144702A - Fluid transport pipe - Google Patents

Abstract

To provide a fluid transport pipe which is simple in structure and light in weight.SOLUTION: A fluid transport pipe 1 is mainly constituted of a flexible pipe 3, a resin layer 5, a protection layer 11, and the like. The flexible pipe 3 is located at the innermost layer of the fluid transport pipe 1, excellent in buckling resistance against the external pressure of, for example, an interlock pipe or the like, and formed of stainless steel which is favorable in corrosion resistance. The resin layer 5 is formed at an external peripheral part of the flexible pipe 3. The protection layer 11 is formed at the outermost periphery of the fluid transport pipe 1 being an external peripheral part of an inner pipe 7. The protection layer 11 is a cylindrical member in which high-strength fibers are arranged in a resin being a raw material, and the resin and the high-strength fibers are integrated with each other. Here, as the resin, for example, a polyaramid fiber and a polyurethane fiber are employable. Further, as the high-strength fiber, for example, a polyester fiber and an aramid fiber are employable.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fluid transport pipe capable of transporting fluid such as gas or liquefied gas in water.

2. Description of the Related Art Conventionally, flexible fluid transport pipes are used to transport fluids such as oil and gas between a floating structure and the seabed in water (for example, in the sea). Fluid transport pipes are required to have various properties such as internal pressure resistance to withstand the internal pressure of the fluid inside, in addition to flexibility.

FIG. 5 is a schematic diagram showing an example of use of such a fluid transport tube. An offshore floating system 100 shown in FIG. 5 mainly includes a floating facility 101, a fluid transport pipe 105 connected thereto, and the like. The floating facility 101 is moored to the seabed 109 by mooring ropes 111, and a fluid transport pipe 105 is connected to the seabed facility (not shown).

As a fluid transport pipe used in this way, for example, a steel concave reinforcing member is used on the outside of a plastic pipe, and the opening side is meshed with each other and spirally wound in two layers at a short pitch to form an internal pressure reinforcing layer. is formed, and an axial force reinforcing layer and an anti-corrosion layer are formed on the outer circumference of the flexible fluid transport pipe (Patent Document 1).

JP-A-7-156285

FIG. 6 is a diagram showing a general structure of a conventional fluid transport pipe 105. As shown in FIG. A general fluid transport pipe 105 is mainly composed of a flexible tube 117, a resin layer 121, an internal pressure reinforcing layer 125, an axial force reinforcing layer 127, a protective layer 129, and the like.

The flexible tube 117 is, for example, a flexible tubular body such as an interlock tube, and is provided with a resin layer 121 around it to ensure fluid tightness and watertightness. A floor layer 119a is provided between the flexible tube 117 and the resin layer 121 as required.

An internal pressure reinforcing layer 125 is provided on the outer peripheral portion of the resin layer 121 . The internal pressure reinforcing layer 125 is a reinforcing layer against the internal pressure of the fluid flowing inside the flexible tube 117 . The internal pressure reinforcing layer 125 is formed by winding, for example, a metal tape having a C-shaped cross section or a Z-shaped cross section at a short pitch so as to face each other and overlap each other in the axial direction.

An axial force reinforcing layer 127 is provided on the outer periphery of the internal pressure reinforcing layer 125 via the floor layer 119b. The axial force reinforcing layer 127 is a reinforcing layer mainly for suppressing deformation of the flexible tube 117 in the axial direction. The axial force reinforcing layer 127 is formed, for example, by alternately winding two layers of reinforcing strips having a flat cross section with a long pitch via the floor layer 119c.

A protective layer 129 is provided on the outer peripheral portion of the axial force reinforcing layer 127 via the floor layer 119d. The protective layer 129 is a layer for preventing, for example, seawater from entering the reinforcing layer.

Such a conventional fluid transport pipe 105 can obtain extremely high resistance to internal pressure while ensuring flexibility. However, such a configuration increases the weight of the fluid transport tube. In particular, when used in deep water, the total length of the fluid transport pipe 105 is long, and in the vicinity of the floating facility 101, tension is applied by the weight of the fluid transport pipe 105 over the entire length of the sea, so axial force reinforcement with higher strength is required. The layer 127 becomes necessary, and there is concern that the weight of the fluid transport pipe 105 will increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluid transport pipe with a simple structure and light weight.

In order to achieve the above object, the present invention provides a fluid transport pipe for underwater use, comprising a flexible inner pipe, and a protective layer provided on the outermost periphery of the inner pipe. , wherein the protective layer has high-strength fibers inside, and the high-strength fibers and resin are integrated.

An intermediate layer may be provided between the inner tube and the protective layer, the intermediate layer and the protective layer may not be integrated, and the protective layer may be slidable with respect to the intermediate layer. .

It is desirable that the hardness of the intermediate layer is higher than the hardness of the protective layer.

An uneven shape may be formed on the outer peripheral surface of the intermediate layer or the inner peripheral surface of the protective layer.

A heat insulating layer may be provided on the inner peripheral surface side of the protective layer.

According to the present invention, the internal pressure reinforcing layer and/or the axial force reinforcing layer and the protective layer are integrated, and the high-strength fibers ensure internal pressure resistance and axial tension resistance, so that the structure is simple and lightweight. be. Also, due to such light weight, the required axial force is reduced, and the axial force reinforcing layer can also be integrated with the protective layer. Therefore, it is possible to obtain a fluid transport pipe that is lighter in weight and simple in structure.

In addition, by providing an intermediate layer that is not integrated with the protective layer between the inner pipe and the protective layer, when the fluid transport pipe is bent and unevenness is formed on the inner surface of the protective layer due to wrinkles, etc., the intermediate layer The layer can suppress damage to the resin layer of the inner tube due to the unevenness of the protective layer. At this time, since the protective layer is slidable with respect to the intermediate layer, when the fluid transport pipe is bent, the protective layer and the intermediate layer slide, thereby suppressing a decrease in flexibility.

At this time, especially if the hardness of the intermediate layer is equal to or higher than the hardness of the protective layer, the protective layer suppresses deformation of the intermediate layer, thereby more reliably suppressing damage to the inner tube.

Further, if the outer peripheral surface of the intermediate layer or the inner peripheral surface of the protective layer is formed with unevenness, the contact area between the two can be reduced, and the slidability between the two can be improved.

Further, if a heat insulating layer is provided on the inner peripheral surface side of the protective layer, freezing of the outside of the fluid transport pipe can be suppressed even when a cryogenic fluid is transported inside.

According to the present invention, it is possible to provide a lightweight fluid transport pipe with a simple structure.

FIG. 2 is a cross-sectional perspective view showing the fluid transport pipe 1; FIG. 2 is an axial cross-sectional view showing the fluid transport pipe 1; FIG. 2 is an axial cross-sectional view showing a fluid transport pipe 1a; FIG. 2 is an axial cross-sectional view showing a fluid transport pipe 1b; The figure which shows the offshore floating body system 100. FIG. FIG. 4 is a cross-sectional perspective view showing a conventional fluid transport pipe 105;

(First embodiment)
A fluid transport pipe according to an embodiment of the present invention will be described below. 1 is a perspective cross-sectional view of the fluid transport pipe 1, and FIG. 2 is a circumferential cross-sectional view of the fluid transport pipe 1. As shown in FIG. The fluid transport pipe 1 is mainly used in the sea (under water), and in addition to transporting LNG, petroleum, etc. described above, the fluid transport pipe 1 can also be used for transporting liquefied carbon dioxide, etc. The fluid transport pipe 1 is mainly flexible. It is composed of a tube 3, a resin layer 5, a protective layer 11, and the like.

The flexible tube 3 is located in the innermost layer of the fluid transport tube 1, and is made of stainless steel, which has excellent buckling strength against external pressure and good corrosion resistance, such as an interlock tube. In this case, the flexible tube 3 is constructed by forming a tape into an S-shaped cross section and connecting the tapes by engaging with each other at the S-shaped portion, and has flexibility. Instead of the interlock tube, it is also possible to use another type of tube such as a bellows tube as long as it has similar flexibility and excellent buckling strength.

A resin layer 5 is provided on the outer periphery of the flexible tube 3 . The resin layer 5 shields fluid flowing through the flexible tube 3 . The resin layer 5 is made of resin such as polyethylene. A floor layer 9 may be provided between the flexible tube 3 and the resin layer 5 . The floor layer 9 is provided as necessary and is a layer for substantially flattening the uneven shape of the outer periphery of the flexible tube 3 , and is deformable following the flexibility of the flexible tube 3 . For example, the floor layer 9 is made of non-woven fabric or the like, and has a certain thickness, and functions as a cushion for the irregularities on the outer periphery of the flexible tube 3 .

The resin layer 5 provided on the outer periphery of the flexible tube 3 does not necessarily mean that the flexible tube 3 and the resin layer 5 are in contact with each other. The resin layer 5 is said to be provided "on the outer periphery" of the flexible tube 3 even if other layers are provided therebetween. Moreover, in the following description, the same applies to the case where the term "peripheral portion" is used. 2 and subsequent drawings, illustration of the floor layer 9 is omitted.

Here, the flexible tube 3 and the resin layer 5 are combined to form an inner tube 7 . If the airtightness and watertightness of the internal fluid can be ensured only by the flexible tube 3, the resin layer 5 is unnecessary. As described above, the inner tube 7 is not particularly limited as long as it is flexible, allows the fluid to flow therein, and can block the outflow to the outside.

A protective layer 11 is provided on the outer periphery of the inner tube 7 and on the outermost periphery of the fluid transport tube 1 . The protective layer 11 is a cylindrical member in which high-strength fibers are arranged inside a resin that is a base material, and the resin and the high-strength fibers are integrated. As the resin, for example, a polyaramid-based resin or a polyurethane-based resin can be applied. Moreover, as high-strength fibers, for example, polyester fibers and aramid fibers can be applied.

Here, the high-strength fibers arranged inside the resin are not arranged with their longitudinal directions directed in one direction, but are arranged in two directions, for example, the circumferential direction and the axial direction of the protective layer 11. is desirable. For example, it may be desirable to use a cloth woven with high-strength fibers in a grid.

In addition, since the protective layer 11 using such a high-strength fiber composite resin has a certain degree of rigidity, the flexibility of the fluid transport pipe 1 may decrease. For this reason, it is desirable that the protective layer 11 and the inner tube 7 are not fused or adhered over the entire length, but are at least partly slidable with respect to each other. In this manner, slippage occurs between the protective layer 11 and the inner tube 7, so that the flexibility of the fluid transport tube 1 can be improved.

Next, the outline of the manufacturing method of the fluid transport pipe 1 will be described. First, a floor tape is wound around the prefabricated flexible tube 3 as necessary to form a floor layer 9 (FIG. 1). The inner tube 7 is formed by forming the resin layer 5 by extruding and covering the outer peripheral portion of the flexible tube 3 with the resin layer 5 using an extruder.

On the other hand, a cylindrical protective layer 11 is formed by extruding and coating a resin while feeding high-strength fibers formed in a cylindrical shape. Finally, the inner tube 7 is inserted inside the protective layer 11 . As described above, the fluid transport pipe 1 is formed. That is, the inner tube 7 and the protective layer 11 are manufactured separately. The protective layer 11 may be formed by arranging high-strength fibers on the outer circumference of the inner tube 7 and directly coating the resin by extrusion.

As described above, according to the present embodiment, the conventionally used internal pressure reinforcing layer and/or axial force reinforcing layer are formed integrally with the protective layer 11, thereby achieving internal pressure resistance and axial tension resistance with a simple structure. It is possible to obtain the fluid transport pipe 1 capable of ensuring the characteristics. In particular, it is possible to obtain an extremely lightweight and compact fluid transport pipe 1 by eliminating the internal pressure reinforcing layer and the axial force reinforcing layer, which have conventionally been constructed using metal strips. In this way, even if the structure is simpler than the conventional internal pressure reinforcing layer using a steel concave member, etc., it can be used, for example, to transport liquefied carbon dioxide, which liquefies at a pressure of about 5 MPa even at room temperature. If the necessary internal pressure resistance can be ensured, it is sufficiently applicable.

In this case, the protective layer 11 has higher rigidity than the protective layer of the conventional fluid transport pipe, but the inner pipe 7 and the protective layer 11 are not completely integrated by fusion bonding or the like, and are separated from each other. By doing so, the flexibility of the fluid transport pipe 1 can be ensured.

(Second embodiment)
Next, a second embodiment will be described. FIG. 3(a) is a cross-sectional view showing a fluid transport pipe 1a according to the second embodiment. In the following description, the same reference numerals as those in FIGS. 1 and 2 are given to components having the same functions as those of the fluid transport pipe 1, and overlapping descriptions are omitted.

The fluid transport pipe 1 a has substantially the same configuration as the fluid transport pipe 1 , but differs in that an intermediate layer 13 is formed on the outer peripheral portion of the inner pipe 7 . That is, the intermediate layer 13 is provided between the inner tube 7 and the protective layer 11 in the fluid transport tube 1a. In addition, as described above, the protective layer 11 is provided on the outer peripheral portion of the inner pipe 7 also in this case.

The intermediate layer 13 may be made of metal or resin, and preferably has a hardness higher than the hardness (Shore D hardness) of the resin forming the protective layer 11, for example. For example, it is desirable that the intermediate layer 13 be made of a resin having a hardness higher than that of the resin forming the protective layer 11 . A fiber reinforcing tape or the like may be further wound between the intermediate layer 13 and the inner tube 7 for reinforcement. Also, the intermediate layer 13 itself may be made of a high-strength fiber composite resin instead of solid resin.

The intermediate layer 13 is formed by, for example, extruding the resin layer 5 of the inner tube 7 described above and then extruding the intermediate layer 13 around the outer periphery of the resin layer 5 . Alternatively, a tape-shaped intermediate layer 13 may be wound around the outer circumference of the resin layer 5 . On the other hand, as described above, the intermediate layer 13 and the protective layer 11 are not integrated, and the protective layer 11 can slide with respect to the intermediate layer 13 .

Here, as shown in FIG. 3B, an uneven shape may be formed on the outer peripheral surface of the intermediate layer 13 (the surface facing the protective layer 11). By doing so, the contact area between the intermediate layer 13 and the protective layer 11 is reduced, and the insertion resistance when the intermediate layer 13 (the inner tube 7) is inserted into the cylindrical protective layer 11 is reduced. can be done. Moreover, the slidability of both can be improved. In addition, unevenness may be formed on the inner peripheral surface of the protective layer 11 instead of the outer peripheral surface of the intermediate layer 13 . The concave-convex shape may be formed by a mold during extrusion molding, or may be processed separately after extrusion molding.

As described above, when the fluid transport pipe 1a is bent, it slides between the intermediate layer 13 and the protective layer 11, so that a decrease in flexibility can be suppressed. On the other hand, when the protective layer 11 is bent, unevenness due to wrinkles or the like may be formed on the inner surface of the protective layer 11 in some cases. In such a case, the existence of the intermediate layer 13 inside the protective layer 11 can prevent the unevenness of the protective layer 11 from coming into contact with the inner tube 7 and damaging the inner tube 7 . That is, the intermediate layer 13 functions to protect the inner tube 7 from the protective layer 11 .

As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained. In addition, by providing the intermediate layer 13 between the protective layer 11 and the inner tube 7, it is possible to suppress the inner tube 7 from being damaged by the uneven shape of the inner surface that occurs when the protective layer 11 is bent. .

At this time, by making the intermediate layer 13 harder than the protective layer 11 , the intermediate layer 13 can be prevented from being deformed by the protective layer 11 .

Further, by forming an uneven shape on either of the facing surfaces of the intermediate layer 13 and the protective layer 11, the contact area between the intermediate layer 13 and the protective layer 11 is reduced, and the slidability between the two can be improved. . Therefore, the flexibility of the fluid transport pipe 1a can be enhanced.

(Third embodiment)
Next, a third embodiment will be described. FIG. 4 is a cross-sectional view showing a fluid transport pipe 1b according to the third embodiment. The fluid transport pipe 1 b has substantially the same configuration as the fluid transport pipe 1 a , but differs in that a heat insulating layer 15 is provided between the intermediate layer 13 and the protective layer 11 . In addition, as described above, the protective layer 11 is provided on the outer peripheral portion of the inner pipe 7 also in this case.

The heat insulating layer 15 is made of foamed resin, glass wool, or the like, for example. In addition, a heat insulating material may be placed on the outer periphery of the intermediate layer 13 and inserted into the cylindrical protective layer 11, or the protective layer 11 and the heat insulating layer 15 may be integrally formed into a cylindrical shape, An intermediate layer 13 (inner tube 7) may be inserted therein.

According to the third embodiment, effects similar to those of the first embodiment can be obtained. In addition, by providing the heat insulating layer 15 on the inner peripheral side of the protective layer 11, freezing of the outer surface of the protective layer 11 can be suppressed even when a low-temperature fluid is transported.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not influenced by the above-described embodiments. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. be understood to belong to

For example, it goes without saying that each embodiment can be combined with each other. For example, in the second embodiment, the intermediate layer 13 and the protective layer 11 face each other in an uneven shape. You may form uneven|corrugated shape on one of the opposing surfaces. In a third form, the protective layer 11 and the intermediate layer 13 may be formed integrally with the heat-insulating layer 15 sandwiched therebetween, and the separate inner tube 7 may be inserted therein.
Also, the heat insulating layer 15 may be provided directly on the outer circumference of the inner pipe 7 .

Reference Signs List 1, 1a, 1b Fluid transport tube 3 Flexible tube 5 Resin layer 7 Inner tube 9 Floor layer 11 Protective layer 13 Intermediate layer 15 …… Thermal insulation layer 100 …… Ocean floating system 101 …… Floating equipment 105 …… Fluid transport pipe 109 …… Sea floor 111 …… Mooring cable 117 …… Flexible tubes 119a, 119b, 119c, 119d …… Seat layer 121 …… Resin layer 125 …… Internal pressure reinforcing layer 127 …… Axial force reinforcing layer 129 …… Protective layer

Claims (5)

A fluid transport tube for use in water, comprising:
a flexible inner tube;
a protective layer provided on the outermost periphery of the inner tube;
and
The fluid transport pipe, wherein the protective layer has high-strength fibers inside, and the high-strength fibers and resin are integrated. having an intermediate layer between the inner tube and the protective layer;
2. The fluid transport pipe according to claim 1, wherein said intermediate layer and said protective layer are not integrated, and said protective layer is slidable with respect to said intermediate layer. 3. The fluid transport pipe according to claim 2, wherein the hardness of the intermediate layer is higher than or equal to the hardness of the protective layer. 4. The fluid transport pipe according to claim 2, wherein the outer peripheral surface of the intermediate layer or the inner peripheral surface of the protective layer is uneven. 5. The fluid transport pipe according to any one of claims 1 to 4, wherein a heat insulating layer is provided on the inner peripheral surface side of said protective layer.

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