JP7518869B2 - Double-tube structure, method for forming same, and tube support member - Google Patents

Description

The present invention relates to a double-tube structure, a method for forming the same, and a tube support member.

Conventionally, for ships that use liquefied natural gas (LNG) as fuel gas and run on gas engines, the IGC Code, IGF Code, etc. stipulate that the engine room in which the gas engine is housed must be a gas safe machinery space. In engine rooms designed in accordance with these regulations, in consideration of the possibility of fuel gas leaks, the fuel line, which is the piping through which the fuel gas flows, and the equipment that comes into contact with the fuel gas, are surrounded by another structure to form a double-pipe structure, and the inside of the double-pipe structure is constantly ventilated (see, for example, Patent Document 1).

In the double-pipe structure, a fuel gas flow path is formed in the inner pipe, an annular ventilation air flow path is formed between the inner pipe and the outer pipe, and supports are arranged at predetermined locations in the longitudinal direction as pipe support members to keep the cross-sectional area of the air flow path constant.

Figure 2 is a perspective view of a support arranged in a conventional double-tube structure, and Figure 3 is a diagram for explaining the vertical assembly procedure of a conventional double-tube structure.

In the figure, Pu is a double-tube structure, 43 is an inner tube, 44 is an outer tube, 45 is a support that is arranged to surround the inner tube 43 and serves as a tube support member that supports the inner tube 43, and 46 and 47 are rings that are fitted onto the inner tube 43 at one end side and the other end side of the double-tube structure Pu, and are arranged in contact with the support 45, serving as positioning members that position the support 45 relative to the inner tube 43.

The support 45 is formed integrally by cutting a cylindrical member made of fluororesin using a molding method such as injection molding to a specified length and machining it to have an annular shape.

The rings 46 and 47 are made of stainless steel and have an inner diameter slightly larger than the outer diameter of the inner tube 43 so that they can be slidably fitted onto the inner tube 43.

The ring 46 is adhered and fixed to the inner tube 43 by a resin adhesive 48 applied to the edge eg1, and the ring 47 is adhered and fixed to the inner tube 43 by an adhesive 48 applied to the edge eg2.

The support 45 is made of an annular body and includes an annular portion 51 and protrusions 52 formed by protruding radially outward at multiple locations in the circumferential direction of the support 45 (four locations in this embodiment). The inner diameter of the annular portion 51 is made slightly larger than the outer diameter of the inner tube 43 so that the support 45 can be slidably fitted onto the inner tube 43.

When the outer tube 44 is fitted onto the support 45, a fan-shaped hole is formed between each of the protrusions 52 in the circumferential direction of the support 45, connecting the air flow paths between the inner tube 43 and the outer tube 44 and allowing air to pass through.

JP 2017-82728 A

However, in the conventional double-tube structure Pu, when fitting the outer tube 44 onto the supports 45 arranged at multiple locations on the inner tube 43, it is necessary to adjust the fit between the supports 45 and the outer tube 44, making the work of forming the double-tube structure cumbersome.

In addition, in the conventional double-tube structure Pu, rings 46 and 47 are required to position the support 45 relative to the inner tube 43, and the rings 46 and 47 must be adhered to the inner tube 43 with adhesive 48, making the work of forming the double-tube structure even more cumbersome.

The present invention aims to provide a double-tube structure, a method for forming the same, and a tube support member that can solve the problems of the conventional double-tube structure Pu and simplify the work required to form the double-tube structure.

To this end, the double-pipe structure of the present invention comprises an inner pipe and an outer pipe, in which a first flow path for passing a first fluid is formed, and between the inner pipe and the outer pipe, a second flow path for passing a second fluid is formed.

The support ring is made of an annular body integrally formed from resin and is disposed to surround the inner tube, and a holder is attached to a predetermined location on the outer tube to hold the support ring.

According to the present invention, the double-pipe structure includes an inner pipe and an outer pipe, in which a first flow path for passing a first fluid is formed within the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe.

The support ring is made of an annular body integrally formed from resin and is disposed to surround the inner tube, and a holder is attached to a predetermined location on the outer tube to hold the support ring.

In this case, a holder is attached to a specified location on the outer tube, and the support ring is held by the holder, so there is no need to fit the outer tube onto the support ring, and there is no need to adjust the fit between the support ring and the outer tube.

In addition, the support ring can be positioned relative to the inner tube simply by attaching the holder to the outer tube.

This simplifies the process of forming a double-tube structure.

1 is a perspective view of a double-tube structure according to an embodiment of the present invention. FIG. 11 is a perspective view of a support provided in a conventional double-tube structure. 1A to 1C are diagrams for explaining a vertical assembly procedure of a conventional double-tube structure. 1 is a conceptual diagram of a main portion of a ship equipped with a double pipe structure in an embodiment of the present invention. 1 is a longitudinal sectional view of a double-tube structure according to an embodiment of the present invention. 1 is a cross-sectional view of a double-tube structure according to an embodiment of the present invention. FIG. 2 is a perspective view of a support ring according to an embodiment of the present invention. FIG. 2 is a perspective view of a holder according to the embodiment of the present invention. 11A and 11B are diagrams illustrating a state in which a holder is attached to a support ring in the embodiment of the present invention. FIG. 2 is a perspective view showing a support unit according to the embodiment of the present invention. 1 is a perspective view of a double-tube structure with a support unit assembled thereto according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a double-tube structure with a support unit assembled thereto according to an embodiment of the present invention. 1 is a cross-sectional view of a double-tube structure with a support unit installed therein according to an embodiment of the present invention. 1A to 1C are first diagrams illustrating a method for forming a double-tube structure according to an embodiment of the present invention. FIG. 4 is a second diagram for explaining the method of forming the double-tube structure in the embodiment of the present invention. FIG. 11 is a third diagram for explaining the method of forming the double-tube structure in the embodiment of the present invention. FIG. 4 is a fourth diagram for explaining the method of forming a double-tube structure in the embodiment of the present invention. FIG. 5 is a fifth diagram for explaining the method of forming a double-tube structure in the embodiment of the present invention.

The following describes in detail an embodiment of the present invention with reference to the drawings. In this case, we will explain a double-tube structure in an engine room that houses a gas engine, a method for forming the double-tube structure, and a support unit as a tube support member.

Figure 4 is a conceptual diagram of the main parts of a ship equipped with a double-pipe structure according to an embodiment of the present invention.

In the figure, Aru is an machinery space formed in a specified location on the ship in accordance with the provisions of the IGF Code, and the machinery space Aru consists of a gas safety machinery space Ar1 as the first area, and an ESD (emergency shutdown device) protected machinery space Ar2 as the second area. The gas safety machinery space Ar1 is used as an engine room, with a gas engine 22 installed therein. The ESD protected machinery space Ar2 is equipped with a bunker unit 25 for supplying liquefied natural gas to the ship, a tank 26 for storing liquefied natural gas, a heat exchanger 28, a blower 31 as a ventilation device, and the like.

In addition, an air intake 33, an air exhaust 34, and an on-off valve 35 are provided outside the machinery space Aru, and a fuel line L1 connecting the tank 26 and the gas engine 22, and ventilation lines L2 and L3 connecting the air intake 33 and the air exhaust 34 are provided inside the machinery space Aru, and a double pipe structure Pu is formed by the fuel line L1 and the ventilation line L3 from the gas safety machinery space Ar1 to the ESD protection machinery space Ar2.

The liquefied natural gas supplied to the ship from outside the machinery area Aru via the bunker unit 25 is stored in the tank 26 and then sent to the heat exchanger 28 in the amount required to drive the gas engine 22, where it is heated and vaporized by hot water and turned into fuel gas at a predetermined temperature, for example, about 40°C.

The fuel gas flows as the first fluid through the fuel line L1, which is a piping for fuel gas, and is sent to the gas engine 22. After the gas engine 22 is driven, the fuel gas is discharged outside the ship through an exhaust gas line (not shown).

In the ship, in consideration of the case where fuel gas leaks outside the fuel line L1, the double-pipe structure Pu is formed by surrounding the inner pipe 43, which is the first element member formed by the fuel line L1, with the outer pipe 44, which is the second element member formed by the ventilation line L3, which is another structure, and air, which is the second fluid taken in from outside the machinery space Aru, is supplied between the inner pipe 43 and the outer pipe 44 and is discharged outside the machinery space Aru.

For this purpose, the ventilation line L2 for intake is arranged between the air intake 33 and the gas engine 22, and the ventilation line L3 for exhaust is arranged between the gas engine 22 and the air exhaust 34. The air taken in from outside the machinery space Aru by the air intake 33 flows through the ventilation line L2 and is sent to the gas engine 22, where it is heated. After that, it flows between the outer pipe 44 and the inner pipe 43 and is sent from the gas safety machinery space Ar1 to the ESD protection machinery space Ar2. After that, it is separated from the fuel line L1, flows through the ventilation line L3, is sent to the blower 31, and is discharged from the air exhaust 34 to the outside of the machinery space Aru.

Therefore, negative pressure is created in the ventilation lines L2 and L3 by the blower 31, so even if fuel gas leaks from the inner pipe 43, the fuel gas will not escape to the outer pipe 44, but will be sucked in by the blower 31 and discharged outside the machinery space Aru.

For convenience, the inner tube 43 and the outer tube 44 are shown adjacent to each other in the figure.

Next, the double-tube structure Pu will be described.

1 is a perspective view of a double-tube structure according to an embodiment of the present invention, FIG. 5 is a longitudinal cross-sectional view of a double-tube structure according to an embodiment of the present invention, FIG. 6 is a transverse cross-sectional view of a double-tube structure according to an embodiment of the present invention, FIG. 7 is a perspective view of a support ring according to an embodiment of the present invention, FIG. 8 is a perspective view of a holder according to an embodiment of the present invention, FIG. 9 is a view showing a state in which a holder is attached to a support ring according to an embodiment of the present invention, FIG. 10 is a perspective view of a support unit according to an embodiment of the present invention, FIG. 11 is a perspective view of a double-tube structure with a support unit installed according to an embodiment of the present invention, FIG. 12 is a longitudinal cross-sectional view of a double-tube structure with a support unit installed according to an embodiment of the present invention, and FIG. 13 is a transverse cross-sectional view of a double-tube structure with a support unit installed according to an embodiment of the present invention.

In the figure, Pu is a double-pipe structure, which is arranged by connecting multiple flanges (not shown) that are arranged at necessary locations in the machinery space Aru to pipe the double-pipe structure Pu, and is composed of an inner pipe 43 and an outer pipe 44 that is arranged to surround the inner pipe 43.

The inner pipe 43 and the outer pipe 44 are both made of a metal material, in this embodiment stainless steel, and are cut to a predetermined length, and are formed by bending the pipes as necessary when piping the double pipe structure Pu.

Each of the flanges is made of a metal material, in this embodiment, stainless steel, and is made of a plate member having a predetermined shape, in this embodiment, a disk shape, and has an inner pipe connecting portion and an outer pipe connecting portion formed on both sides for connecting the inner pipe 43 and the outer pipe 44.

Both ends of the inner pipe 43 are fixed to the inner pipe connection parts formed on each flange by welding so that the inside and outside of the inner pipe 43 are sealed, and both ends of the outer pipe 44 are fixed to the outer pipe connection parts formed on each flange by welding so that the inside and outside of the outer pipe 44 are sealed, and a gas flow path Rt1 having a circular cross-sectional shape is formed as a first flow path in the inner pipe 43, and an air flow path Rt2 having an annular cross-sectional shape is formed between the inner pipe 43 and the outer pipe 44. In addition, the flange has a plurality of fuel gas holes (not shown) between the inner pipe connection part and the outer pipe connection part to communicate the upstream and downstream gas flow paths Rt1 and pass fuel gas, and a plurality of air holes (not shown) are formed radially outward from the outer pipe connection part to communicate the upstream and downstream air flow paths Rt2 and pass air.

Support arrangement positions St1 are set at a number of predetermined locations in the longitudinal direction of the double-tube structure Pu, and support units 61 are arranged as tube support members at each of the support arrangement positions St1, and the inner tube 43 is supported by the support units 61.

The support unit 61 is arranged to surround the inner tube 43 and is made of a support ring 63, which acts as a tube support ring made of a resin material, in this embodiment, a fluororesin, and a pair of holders 65, 66, which are attached by welding to predetermined locations in the circumferential direction of the outer tube 44, in this embodiment, to the upper and lower ends of the outer tube 44, and serve as a pair of positioning members that hold the support ring 63 in the longitudinal direction of the double tube structure Pu and position it relative to the inner tube 43.

The support ring 63 is made of a ring-shaped body formed of a resin material, in this embodiment a fluororesin, by a molding method such as injection molding, and has an inner diameter slightly larger than the outer diameter of the inner tube 43 so that it can be fitted onto the inner tube 43. Also, as shown in FIG. 7, a groove m1 having a ring shape and a predetermined width and a predetermined depth is formed in the center of the outer peripheral surface S1 of the support ring 63 in the width direction (the longitudinal direction of the inner tube 43) so that the support ring 63 can be positioned by the retainers 65, 66.

In this embodiment, the support ring 63 is made of a fluororesin that is highly resistant to wear, heat, and weather. Therefore, even if the double-tube structure Pu is used for a long period of time, the support ring 63 will not deform, and the durability of the support unit 61 can be improved.

The holders 65, 66 are formed by pressing a metal material, in this embodiment, stainless steel, and have a "baton" shape as shown in Figure 8. The holders 65, 66 also have a cylindrical shape and include a post 68 for attaching the holders 65, 66 to the outer tube 44, and a support holder 69 that is integral with the post 68 and is formed by branching off to the left and right from one end of the post 68 and bending into a "U" shape (semicircular shape).

The radius of curvature of the inner surface of the support holder 69 is made slightly larger than the radius of curvature of the outer surface of the groove m1 so that the support holder 69 can enter the groove m1.

For example, as shown in FIG. 9, when the support holder 69 is inserted into the groove m1 of the support ring 63 and the holders 65 and 66 are attached to the support ring 63, the support unit 61 is formed as shown in FIG. 10.

At the support installation position St1, holes h1 are formed at the upper and lower ends of the outer tube 44 at a pitch angle of 180° to attach the support unit 61 to the upper and lower ends of the outer tube 44. The inner diameter of the holes h1 is made slightly larger than the outer diameter of the posts 68 so that the posts 68 can be fitted into each hole h1.

With each post 68 fitted into each hole h1, the retainers 65, 66 are moved radially outward within the outer tube 44. Next, the support ring 63 fitted onto the inner tube 43 is inserted between the retainers 65, 66, and the retainers 65, 66 are moved radially inward to insert the support retaining portion 69 into the groove m1 of the support ring 63. When the support ring 63 and the support retaining portion 69 are engaged, the support unit 61 is assembled in the double tube structure Pu as shown in FIG. 11.

Then, the outer surface of the post 68 is welded to the inner surface of the hole h1 to seal the inside and outside of the outer tube 44, and the support unit 61 is attached to the double tube structure Pu.

When the support unit 61 is attached to the double-tube structure Pu, the posts 68 of the holders 65, 66 protrude radially outward from the upper and lower ends of the outer tube 44, as shown in Figures 11 to 13.

Therefore, after the support unit 61 is assembled to the double-tube structure Pu, the other end of the post 68, which is the portion protruding from the upper end and the lower end of the outer tube 44, is cut and removed by a cutter or the like (not shown). This forms the double-tube structure Pu as shown in Figures 1, 5, and 6.

In the figure, Sb is the cut surface when the post 68 is cut, and Pt1 is the welded metal part formed between the outer peripheral surface of the post 68 and the inner peripheral surface of the hole h1.

Next, we will explain how to form the double-tube structure Pu.

Figure 14 is a first diagram for explaining a method for forming a double pipe structure in an embodiment of the present invention, Figure 15 is a second diagram for explaining a method for forming a double pipe structure in an embodiment of the present invention, Figure 16 is a third diagram for explaining a method for forming a double pipe structure in an embodiment of the present invention, Figure 17 is a fourth diagram for explaining a method for forming a double pipe structure in an embodiment of the present invention, and Figure 18 is a fifth diagram for explaining a method for forming a double pipe structure in an embodiment of the present invention.

First, as shown in FIG. 14, the inner tube 43 and the outer tube 44 are formed by cutting the tube member to a predetermined length, the support ring 63 is formed by injection molding or the like, and the holders 65, 66 are formed by pressing or the like. As described above, holes h1 are formed at the upper and lower ends of the outer tube 44 at the support arrangement position St1 to allow the posts 68 of the holders 65, 66 to pass through.

Next, as shown in FIG. 15, the holders 65 and 66 are inserted into the outer tube 44 from a predetermined end eg1 of the outer tube 44, and each post 68 is inserted into the hole h1 inside the outer tube 44.

Next, as shown in FIG. 16, the retainers 65 and 66 are moved radially outward within the outer tube 44, the post 68 is caused to protrude a sufficient amount from the hole h1, the support retainer 69 is brought close to the inner peripheral surface of the outer tube 44, and the inner tube 43 with the support ring 63 fitted thereon is advanced into the outer tube 44.

Next, the holders 65, 66 are moved radially inward, and the support holder 69 is inserted into the aforementioned groove m1 (FIG. 7) of the support ring 63, and the support ring 63 and the support holder 69 are engaged, forming a support unit 61 at the support arrangement position St1 of the double-tube structure Pu, as shown in FIG. 17. Then, the outer peripheral surface of the post 68 and the inner peripheral surface of the hole h1 are welded together by the welding device 71.

Then, the other end of the post 68, that is, the portion protruding from the upper end and the lower end of the outer tube 44, is cut and removed with a cutter or the like. This forms the double tube structure Pu as shown in FIG. 18.

In this manner, in this embodiment, the holders 65, 66 are attached to predetermined locations on the outer tube 44, and the support ring 63 is held by the holders 65, 66, so there is no need to fit the outer tube 44 onto the support ring 63, and there is no need to adjust the fit between the support ring 63 and the outer tube 44.

In addition, the support ring 63 can be positioned relative to the inner tube 43 simply by attaching the holders 65, 66 to the outer tube 44.

This simplifies the process of forming the double-tube structure Pu.

Furthermore, the support holding portion 69 of the holder 65, 66 holds the support ring 63 near the outer peripheral surface of the inner tube 43, so that a space large enough to connect the upstream and downstream sides of the air flow path Rt2 is formed between the support holding portion 69 and the inner peripheral surface of the outer tube 44. Therefore, the air flow is not obstructed by the support unit 61.

The present invention is not limited to the above-described embodiment, and various modifications are possible based on the spirit of the present invention, and are not excluded from the scope of the present invention.

43 Inner tube 44 Outer tube 63 Support ring 65, 66 Holder Pu Double tube structure Rt1 Gas flow path Rt2 Air flow path

Claims (5)

A double-pipe structure comprising an inner pipe and an outer pipe, the first flow path being formed in the inner pipe for passing a first fluid, and a second flow path being formed between the inner pipe and the outer pipe for passing a second fluid,
(a) a support ring made of an annular body integrally formed of resin and disposed so as to surround the inner tube;
(b) a holder attached to a predetermined portion of the outer tube and holding the support ring ;
(c) A double-tube structure, characterized in that the holder comprises a post attached to the outer tube and two support holders formed by branching off from one end of the post, and the support ring is held by engaging with the two support holders . (a) the support ring includes a groove ;
2. The double-tube structure according to claim 1 , wherein (b) the support holding portion is inserted into the groove to hold a support ring. (a) the outer tube has a hole formed at the predetermined location so as to penetrate the outer tube from inside to outside;
(b) The double-tube structure according to claim 1 or 2 , wherein the retainer is attached to the outer tube by welding an outer circumferential surface of the post to an inner circumferential surface of the hole. (a) inserting a holder having a post and a support holder into an outer tube;
(b) inserting a post into a hole formed in a predetermined position of the outer tube, moving the retainer radially outward, and inserting the inner tube with the support ring fitted thereon into the outer tube;
(c) A method for forming a double-tube structure, comprising: moving the holder radially inward to engage the support holder with the support ring. A pipe support member disposed in a double pipe structure having an inner pipe and an outer pipe, the first flow path for passing a first fluid being formed in the inner pipe, and a second flow path for passing a second fluid being formed between the inner pipe and the outer pipe,
(a) a support ring made of an annular body integrally formed of resin and disposed so as to surround the inner tube;
(b) A tube support member comprising: a post; and a retainer having two support holding portions formed by branching off from one end of the post, the support ring being held by engaging with the two support holding portions .

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