JP2021124097A - Double pipe structure, support and formation method for double pipe structure - Google Patents

Abstract

To downsize a double pipe structure, to reduce cost and further, to easily perform maintenance/management.SOLUTION: An inner pipe 43 and an outer pipe 44 are provided, a first flow passage is formed inside of the inner pipe 43, and a second flow passage is formed between the inner pipe 43 and the outer pipe 44. A double pipe structure comprises: a support 55 which is integrally formed from a resin and disposed so as to enclose the inner pipe 43 in the second flow passage; partition outer pipes F1 and F2 disposed at an upstream side and a downstream side of the support 55 in a flow direction of a first fluid and hold the support 55 therebetween; and a sleeve 56 which is disposed so as to enclose the support 55 and the partitioning outer pipes F1 and F2 and bonded to the partitioning outer pipes F1 and F2 by welding, thereby making a radially inward space sp airtight. The support 55 is disposed on the second flow passage, thereby reducing a cross-sectional area of the second flow passage.SELECTED DRAWING: Figure 1

Description

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

Conventionally, ships that use liquefied natural gas (LNG) as fuel gas and drive a gas engine to operate are designed based on the regulations of the IGC code, IGF code, etc., and the engine room where the gas engine is housed is a gas safe machinery. It is made into a space (Gas safety space), and in the engine room, the fuel line, which is the pipe through which the fuel gas flows, the equipment in contact with the fuel gas, etc. are surrounded by another structure in consideration of the case where the fuel gas leaks. As a result, a double-tube structure is formed, and the inside of the double-tube 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 the outer pipe is supported by the inner pipe. Supports are provided at predetermined locations in the longitudinal direction to keep the cross-sectional area of the air flow path constant.

FIG. 2 is a perspective view of a support arranged in a conventional double pipe structure.

In the figure, reference numeral 11 denotes a support, which is formed by connecting a pair of holding pieces 13 and 14 formed by molding an elastic metal plate with bolts and nuts bt1 and bt2.

The holding pieces 13 and 14 are one of a receiving portion 16 having a semi-cylindrical shape, connecting portions 17 and 18 extending radially outward from both edges of the receiving portion 16, and the connecting portions 17 and 18. A flap 19 extending in the circumferential direction from the radial outer edge of the connecting portion 17 is provided.

Each receiving portion 16 of the holding pieces 13 and 14 is arranged so as to surround an inner pipe (not shown) of the double pipe structure, and the connecting portion 17 of the holding piece 13 and the connecting portion 18 of the holding piece 14 are bolted. -The holding pieces 13 and 14 are connected by connecting with the nut bt1 and the connecting part 18 of the holding piece 13 and the connecting part 17 of the holding piece 14 are fixed with the bolts and nuts bt2 to connect the holding pieces 13 and 14 and attach the support 11 to the inner pipe. be able to.

In this state, the double pipe structure can be assembled by fitting an outer pipe (not shown) to the support 11 against the urging force of each flap 19.

In the outer pipe, the flap 19 urges the outer pipe by the urging force, so that the outer pipe is supported by the inner pipe and the cross-sectional area of the air flow path is kept constant.

JP-A-2017-82728

However, in the conventional double pipe structure, the support 11 is formed by connecting the pair of holding pieces 13 and 14 with bolts and nuts bt1 and bt2, so that the double pipe structure becomes large. It ends up.

Further, since the outer pipe is supported by the urging force of the flap 19, the double pipe structure is prevented so that the flap 19 and the inner peripheral surface of the outer pipe do not slide due to vibration of a ship or the like to generate sparks. It is necessary to ground the body sufficiently, which increases the cost of the double pipe structure.

Further, when the double pipe structure is used for a long period of time in a ship or the like, the support 11 may be corroded by rust or the like, and the maintenance and management of the double pipe structure is troublesome.

The present invention solves the problems of the conventional double pipe structure, can be miniaturized, can reduce the cost, and can be easily maintained and managed. It is an object of the present invention to provide a method for forming a structure, a support and a double pipe structure.

Therefore, the double pipe structure of the present invention includes an inner pipe and an outer pipe, and a first flow path for passing a first fluid is formed in the inner pipe, and between the inner pipe and the outer pipe. In addition, a second flow path for passing the second fluid is formed.

Then, the support is integrally formed of the resin, has an annular shape, is arranged so as to surround the inner pipe in the second flow path, and has a communication hole for passing the second fluid. , It is arranged on the upstream side and the downstream side of the support in the flow direction of the first fluid, has a tubular shape and has a tubular shape, and surrounds the support and each outer pipe. It has a sleeve that is arranged and joined to each division outer pipe by welding to make the space inward in the radial direction airtight.

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

Then, the support is integrally formed of the resin, has an annular shape, is arranged so as to surround the inner pipe in the second flow path, and has a communication hole for passing the second fluid. , It is arranged on the upstream side and the downstream side of the support in the flow direction of the first fluid, has a tubular shape and has a tubular shape, and surrounds the support and each outer pipe. It has a sleeve that is arranged and joined to each division outer pipe by welding to make the space inward in the radial direction airtight.

In this case, since the support formed integrally by the resin and forming the communication hole for passing the second fluid is arranged in the second flow path between the inner pipe and the outer pipe, the second The cross-sectional area of the flow path can be reduced. Therefore, the double pipe structure can be miniaturized.

Further, since the support is formed of resin, sparks do not occur even if the support and the outer peripheral surface of the inner pipe and the inner peripheral surface of the outer pipe slide due to vibration. Therefore, since the grounding structure of the double pipe structure can be simplified, the cost of the double pipe structure can be reduced.

Further, even if the double pipe structure is used for a long period of time, the support is not corroded by rust or the like, so that the maintenance and management of the double pipe structure can be simplified.

It is XX sectional view of the outer pipe support part of the double pipe structure in 1st Embodiment of this invention. It is a perspective view of the support arranged in the conventional double pipe structure. FIG. 5 is a conceptual diagram of a main part of a ship provided with a double pipe structure according to the first embodiment of the present invention. It is a perspective view of the double tube structure in 1st Embodiment of this invention. It is a perspective view of the support in 1st Embodiment of this invention. It is the first figure for demonstrating the assembly procedure of the outer tube support part in 1st Embodiment of this invention. It is a 2nd figure for demonstrating the assembly procedure of the outer tube support part in 1st Embodiment of this invention. It is a 3rd figure for demonstrating the assembly procedure of the outer tube support part in 1st Embodiment of this invention. It is a 1st figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 2nd figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 3rd figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 4th figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 5th figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 6th figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a 7th figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is the 8th figure for demonstrating the method of forming a double tube structure in 1st Embodiment of this invention. It is a YY cross-sectional view of the outer pipe support part of the double pipe structure in the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a double pipe structure in an engine room in which a gas engine is housed and a method for forming the double pipe structure will be described.

FIG. 3 is a conceptual diagram of a main part of a ship provided with a double pipe structure according to the first embodiment of the present invention.

In the figure, Aru is an engine area formed at a predetermined location on the ship in accordance with the provisions of the IGF Code, and the engine area Aru is a gas safety engine area Ar1 as a first area and a second area. It consists of an ESD (emergency shutoff device) protection agency area Ar2. Then, the gas safety engine area Ar1 is used as an engine room in which the gas engine 22 is arranged. A bunker unit 25, a tank 26, a heat exchanger 28, a blower 31 as a ventilation device, and the like are arranged in the ESD protection engine area Ar2.

Further, an air intake port 33, an air discharge port 34, and an on-off valve 35 are arranged outside the engine area Aru, and a fuel line L1 connecting the tank 26 and the gas engine 22 and an air intake are provided in the engine area Aru. Ventilation lines L2 and L3 connecting the port 33 and the air discharge port 34 are arranged, and a double pipe structure Pu is provided by the fuel line L1 and the ventilation line L3 from the gas safety engine area Ar1 to the ESD protection engine area Ar2. It is formed.

The liquefied natural gas supplied from outside the engine area Aru to the ship via the bunker unit 25 is stored in the tank 26 and then sent to the heat exchanger 28 in an amount necessary to drive the gas engine 22. It is heated by hot water in the heat exchanger 28 and vaporized to be a fuel gas as a first fluid at a predetermined temperature, for example, about 40 [° C.].

The fuel gas flows through the fuel line L1, which is a pipe for the fuel gas, and is sent to the gas engine 22.

By the way, in the ship, in consideration of the case where the fuel gas leaks to the outside of the fuel line L1, the inner pipe 43 as the first element member formed by the fuel line L1 is a second structure which is another structure. The double pipe structure Pu is formed by surrounding with the outer pipe 44 as an element member of the above, and air as a second fluid taken in from the outside of the engine area Aru is introduced between the inner pipe 43 and the outer pipe 44. It is supplied in between and discharged outside the engine area Aru.

Therefore, the ventilation line L2 for intake is arranged between the air intake port 33 and the gas engine 22, and the ventilation line L3 for exhaust is provided between the gas engine 22 and the air discharge port 34. Is arranged, and the air taken in from outside the engine area Aru by the air intake 33 flows through the ventilation line L2, is sent to the gas engine 22, is heated in the gas engine 22, and then is formed by the ventilation line L3. After flowing between the outer pipe 44 and the inner pipe 43 and sent from the gas safety engine area Ar1 to the ESD protection engine area Ar2, it is separated from the fuel line L1 and flows through the ventilation line L3, and the blower 31 Is sent to the outside of the engine area Aru from the air outlet 34.

Therefore, since a negative pressure is formed by the blower 31 in the ventilation lines L2 and L3, even if the fuel gas leaks from the inner pipe 43, the fuel gas is sucked by the blower 31 without going out of the outer pipe 44. And discharged out of the engine area Aru.

In the figure, for convenience, the inner pipe 43 and the outer pipe 44 are shown adjacent to each other.

Next, the double tube structure Pu will be described. In this case, for a double pipe structure Pu having a flange attached to one end, a linearly extending portion, that is, a linear portion, and a bent portion, that is, a bent portion, and having an "L" -shaped shape. explain.

FIG. 4 is a perspective view of the double tube structure according to the first embodiment of the present invention.

In the figure, Pu is a double-tube structure, Di (i = 1, 2) is a plurality of linear structural portions arranged in a linear portion of the double-tube structure Pu, and E1 is a double-tube structure. Two linear structural portions arranged adjacent to the bent portion of Pu, a curved structural portion connected to the linear structural portions D1 and D2 in the present embodiment, 51 are straight lines of the double pipe structure Pu. Two linear structural portions arranged adjacent to the shaped portion, in the present embodiment, a flange connecting the linear structural portion D1 and another linear structural portion (not shown), Srj (j = 1, 2, 3). ) Is an outer pipe support portion set at a plurality of locations in the linear structure portion Di. In the length direction of the double pipe structure Pu, the side on which the flange 51 is arranged is the flange side, and the opposite side is the non-flange side.

The double pipe structure Pu is arranged so as to surround the inner pipe 43 in the inner pipe 43, the outer pipe 44, and each of the outer pipe support portions Srj, and the compartmentalized outer pipe Fk (k = 1, 2, ... 5). ), A resin support 55 (FIG. 1) described later, and a sleeve 56 that surrounds the support 55 in each outer pipe support portion Srj, and has a circular cross-sectional shape in the inner pipe 43. A fuel gas flow path Rt1 is formed as a first flow path for passing gas, and a second flow path for passing air has an annular cross-sectional shape between the inner pipe 43 and the outer pipe 44. The air flow path Rt2 is formed.

The inner pipe 43 is integrally formed by being bent in an "L" shape in the curved structure portion E1.

The outer pipe 44 is arranged so as to surround the inner pipe 43 from the flange side to the non-flange side in the linear structure portion Di, so as to surround the inner pipe 43 in the curved outer pipe Fk and the curved structure portion E1. Two elbows Gk (k = 1, 2) are provided, and the outer pipe Fk is connected by the sleeve 56 at each outer pipe support portion Srj.

The inner pipe 43, the outer pipe 44, the flange 51, and the sleeve 56 are all made of metal, and in the present embodiment, stainless steel.

Next, the outer pipe support portion Srj will be described. In this case, since the structure of each outer pipe support portion Srj is the same, the outer pipe support portion Sr1 will be described.

FIG. 1 is an XX cross-sectional view of an outer tube support portion of a double-tube structure according to the first embodiment of the present invention, and FIG. 5 is a perspective view of a support according to the first embodiment of the present invention. 1 is for explaining the procedure for assembling the outer pipe support portion according to the first embodiment of the present invention, and FIG. 7 is for explaining the procedure for assembling the outer pipe support portion according to the first embodiment of the present invention. FIG. 8 is a third diagram for explaining the procedure for assembling the outer pipe support portion in the first embodiment of the present invention.

In the figure, Sr1 is an outer pipe support, 43 is an inner pipe, 44 is an outer pipe, Rt1 is a fuel gas flow path, Rt2 is an air flow path, F1 and F2 are classified outer pipes, 55 is a support, and 56 is a sleeve. .. The support 55 is integrally formed of a resin or, in the present embodiment, a fluororesin by a molding method such as injection molding, and has an annular shape.

Therefore, since the wear resistance, heat resistance, and weather resistance are high, the support 55 is not deformed even if the double pipe structure Pu is used for a long period of time, and the durability of the support 55 can be improved. ..

In the outer pipe support portion Sr1, the inner diameter of the sleeve 56 is outside the outer pipes F1, F2 and the support 55 so that the support 55 is surrounded by the sleeve 56 and the outer pipes F1 and F2 are held by the support 55. Slightly larger than the diameter.

Further, the support 55 serves as a second annular body formed at a predetermined distance from the inner annular portion 61 as the first annular body and the inner annular portion 61 radially outward from the inner annular portion 61. The outer annular portion 62 and the support 55 are provided with connecting portions 65 for connecting the inner annular portion 61 and the outer annular portion 62 at four locations in the circumferential direction, and in the present embodiment, the outer annular portion 62 is provided. In the present embodiment, "U" -shaped grooves 67 are formed at a plurality of locations on the outer peripheral surface of the above, and at four locations on the radial outer side of each connecting portion 65. The inner diameter of the inner annular portion 61 is slightly larger than the outer diameter of the inner pipe 43 so that the support 55 can be slid and fitted on the inner pipe 43.

A communication hole 71 having a fan-shaped shape between the connecting portions 65 in the circumferential direction of the support 55 and communicating the air flow path Rt2 on the flange side and the non-flange side with the support 55 to allow air to pass through is provided. It is formed.

Further, the width of the inner annular portion 61 and the connecting portion 65 in the axial direction of the support 55 is made larger than the width of the outer annular portion 62, and the predetermined portion of the support 55, in the present embodiment, the flange side of the connecting portion 65 and the width of the connecting portion 65. A holding portion 73 for holding the outer classification pipes F1 and F2 at predetermined positions is formed on the outer peripheral surface of the portion protruding toward the non-flange side. The dimensions of the support 55 are set so that the outer peripheral surface of the support 55 is located radially outward from the outer peripheral surfaces of the outer sections F1 and F2 while the outer sections F1 and F2 are held by the holding portion 73. ..

In the sleeve 56, the edge eg1 on the flange side is joined to the outer pipe F1 by welding, and the edge eg2 on the non-flange side is joined to the outer pipe F2 by welding to make the space sp in the radial direction airtight. The distance ε between each edge eg1 and eg2 and the outer annular portion 62 of the support 55 is set to 100 [mm] or more so that the heat generated by welding is not transferred to the support 55 and the support 55 is not damaged. .. Since the support 55 is made of fluororesin, it has high heat resistance. Therefore, even if the distance ε between each edge eg1 and eg2 and the outer annular portion 62 of the support 55 is shortened, the support 55 is not affected by heat, so that the structure of the double pipe structure Pu should be simplified. Can be done.

When assembling the outer pipe support portion Sr1, first, as shown in FIG. 6, the division outer pipe F1, the support 55 and the division outer pipe F2 are externally fitted to the inner pipe 43, and at this time, the holding portion 73 is placed on the flange side. The holding portion 73 is surrounded by the edge eg3 on the non-flange side of the outer pipe F1 and the holding portion 73 is surrounded by the edge eg4 on the flange side of the outer pipe F2, and the outer pipes F1 and F2 are held by the support 55. To do so.

Subsequently, as shown in FIGS. 7 and 8, the sleeve 56 is fitted onto the support 55 and the outer sections F1 and F2, and the edges eg1 and eg2 are fixed to the outer tubes F1 and F2 by welding.

Next, a method for forming the double tube structure Pu will be described.

FIG. 9 is a first diagram for explaining a method of forming a double-tube structure according to the first embodiment of the present invention, and FIG. 10 is a double-tube structure according to the first embodiment of the present invention. A second figure for explaining a forming method, FIG. 11 is a third figure for explaining a method for forming a double-tube structure according to the first embodiment of the present invention, and FIG. 12 is a third figure for explaining the forming method. FIG. 4 for explaining the method for forming the double-tube structure according to the first embodiment, FIG. 13 is for explaining the method for forming the double-tube structure according to the first embodiment of the present invention. FIG. 5 and FIG. 14 are a sixth diagram for explaining a method of forming a double-tube structure in the first embodiment of the present invention, and FIG. 15 is a second in the first embodiment of the present invention. A seventh figure for explaining a method for forming a heavy-duty tube structure, and FIG. 16 is an eighth view for explaining a method for forming a double-tube structure according to the first embodiment of the present invention.

First, a pipe member (not shown) made of stainless steel is cut to a predetermined length and bent to obtain an inner pipe 43 having linear portions h1, h2 and bent portions h3 as shown in FIG. It is formed. eg5 is an edge on the flange side of the inner pipe 43, and egg6 is an edge on the non-flange side of the inner pipe 43.

Next, as shown in FIGS. 10 and 11, at the edge eg5 on the flange side of the inner pipe 43, the outer pipe F2, the support 55, the sleeve 56 and the outer pipe F1 are externally fitted to the inner pipe 43, and the outer pipe F1 is fitted to the inner pipe 43. The boss portion 51a of the flange 51 is internally fitted into the inner pipe 43. Then, the support 55 is sandwiched by the outer division pipes F1 and F2 fitted on the upstream side and the downstream side of the support 55 in the flow direction of the fuel gas, and the sleeve 56 is joined to the outer division pipes F1 and F2 by welding in that state. Further, the flange 51 is joined to the inner pipe 43 by welding, and the linear structure portion D1 is formed as shown in FIG.

Subsequently, at the edge eg6 on the non-flange side of the inner pipe 43, the elbows G1 and G2 are fitted onto the inner pipe 43, and the outer pipes F2 and the elbow G1 are joined by welding, and the elbow G1 and the elbow G2 are joined by welding. Then, as shown in FIG. 13, the curved structure portion E1 is formed.

Next, as shown in FIG. 14, at the edge eg6 on the non-flange side of the inner pipe 43, the division outer pipe F3, the support 55 and the sleeve 56 are externally fitted to the inner pipe 43, and further, as shown in FIG. The outer pipe F4, the support 55, the sleeve 56, and the outer pipe F5 are fitted into the inner pipe 43.

Then, the elbow G2 and the division outer pipe F3 are joined by welding, the sleeve 56 is joined to the division outer pipes F3 and F4 by welding while the support 55 is sandwiched by the division outer pipes F3 and F4, and the support 55 is divided. The sleeve 56 is joined to the compartmentalized outer pipes F4 and F5 by welding while being sandwiched by the outer pipes F4 and F5, and a linear structural portion D2 is formed as shown in FIG.

In this way, as shown in FIG. 16, a double tube structure Pu composed of a linear structure portion Di and a curved structure portion E1 is formed.

As described above, in the present embodiment, the support 55 integrally formed of the resin and formed with the communication hole 71 for passing air is arranged in the air flow path Rt2 between the inner pipe 43 and the outer pipe 43. Since it is provided, the cross-sectional area of the air flow path Rt2 can be reduced. Therefore, the double pipe structure Pu can be miniaturized and the mountability on a ship can be improved.

Further, since the support 55 is made of resin, sparks do not occur even if the support 55 and the outer peripheral surface of the inner pipe 43 and the inner peripheral surface of the outer pipe 44 slide due to vibration. Therefore, the grounding structure of the double pipe structure Pu can be simplified, and the cost of the double pipe structure Pu can be reduced.

Further, even if the double pipe structure Pu is used for a long period of time, the support 55 is not corroded by rust or the like, so that the maintenance and management of the double pipe structure Pu can be simplified.

Next, a second embodiment of the present invention in which the inner pipe 43 includes a plurality of compartmentalized inner pipes like the outer pipe 44 will be described. The same reference numerals are given to those having the same structure as that of the first embodiment, and the effects of the same embodiment are used for the effects of the invention due to having the same structure.

FIG. 17 is a YY cross-sectional view of the outer pipe support portion of the double pipe structure according to the second embodiment of the present invention.

In the figure, Pu is a double pipe structure, Sr11 is an outer pipe support portion, 43 is an inner pipe as a first element member, 44 is an outer pipe as a second element member, and Rt1 is a first flow path. Fuel gas flow path, Rt2 is an air flow path as a second flow path, Q1 is an inner pipe joint set at a predetermined position of the inner pipe 43, 55 is a flow direction of fuel gas as a first fluid. A pair of supports arranged on the upstream side and the downstream side in the above, 56 is a sleeve, and 81 is arranged so as to surround the inner pipe 43 adjacent to the support 55 on the inner pipe joint Q1 side of each support 55. , A stopper as a positioning member for positioning the support 55. The stopper 81 has an annular shape.

The inner pipe 43 is formed by joining the inner pipes H11 and H12 arranged on the upstream side and the downstream side of the inner pipe joint portion Q1 in the flow direction of the fuel gas by welding.

The outer pipe 44 includes compartmentalized outer pipes F11 and F12 arranged on the upstream side and the downstream side of the inner pipe joint portion Q1 so as to surround the inner pipe 43 in the linear structure portion Di (FIG. 4).

The support 55 is positioned by the stopper 81 on the inner pipe joint Q1 side, movement to the inner pipe joint Q1 side is restricted, and on the opposite side, the outer division pipes F11 and F12 held by the holding portion 73. Positioned.

In the sleeve 56, one edge egg1 is joined to the outer section pipe F11 by welding, and the other edge egg2 is joined to the outer section tube F12 by welding, so that the space sp11 in the radial direction of the sleeve 56 is airtight. The distance between each edge eg1 and eg2 and the outer annular portion 62 as the second annular body of the support 55 and the inner side so that the heat generated by welding is not transferred to the support 55 and the support 55 is damaged. The distance between the pipe joint portion Q1 and the outer annular portion 62 of the support 55 is set to 100 [mm] or more.

In the outer pipe support portion Sr11, the inner diameter of the sleeve 56 is set to the outer pipes F11, F12 and each support so that each support 55 is surrounded by the sleeve 56 and the outer pipes F11 and F12 are held by the supports 55. Slightly larger than the outer diameter of 55.

Further, the inner diameter of the stopper 81 is slightly larger than the outer diameter of the inner pipe 43 so that the stopper 81 can be fitted on the inner pipe 43.

The inner pipe 43, the outer pipe 44, the flange 51, the sleeve 56, and the stopper 81 are all made of metal, and in the present embodiment, stainless steel. The stopper 81 is attached to the inner pipe 43 by an adhesive for metal, and in the present embodiment, a bond 82 for stainless steel. Further, the support 55 is integrally formed in an annular shape by a molding method such as injection molding with a resin or, in the present embodiment, a fluororesin.

When forming the double pipe structure Pu shown in FIG. 17, first, the division inner pipes H11 and H12 are joined by welding at the inner pipe joint portion Q1, and the support 55 is formed on the upstream side and the downstream side of the inner pipe joint portion Q1. Is fitted onto the inner pipe 43, and each support 55 is positioned by the stopper 81 on the inner pipe joint Q1 side of each support 55.

Subsequently, on the upstream side and the downstream side of each support 55, each support 55 is positioned by the outer division pipes F11 and F12, and the sleeve 56 is externally fitted to each support 55 and each stopper 81, and each outer division pipe F11, It is joined to F12 by welding.

The present invention is not limited to each of the above-described embodiments, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

43 Inner pipe 44 Outer pipe 55 Support 56 Sleeve 71 Communication holes F1 to F5, F11, F12 Classification Outer pipe Pu Double pipe structure Rt1 Fuel gas flow path Rt2 Air flow path sp1, sp11 Space

Claims (7)

An inner pipe and an outer pipe are provided, a first flow path for passing a first fluid is formed in the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe. In the double pipe structure in which the flow path is formed,
(A) A support integrally formed of a resin, having an annular shape, arranged so as to surround an inner pipe in the second flow path, and having a communication hole for passing a second fluid. When,
(B) An outer pipe that is arranged on the upstream side and the downstream side of the support in the flow direction of the first fluid and sandwiches the support, and
(C) It has a tubular shape, is arranged so as to surround the support and each outer pipe of each division, and is joined to each outer pipe of each division by welding to make the space inward in the radial direction airtight. A double tube structure characterized by having a sleeve. The double pipe structure according to claim 1, wherein the outer pipes on the upstream side and the downstream side of the support in the flow direction of the first fluid are held in a predetermined position by a holding portion formed on the support. The double tube structure according to claim 1 or 2, wherein the support is formed of a fluororesin. An inner pipe and an outer pipe are provided, a first flow path for passing a first fluid is formed in the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe. In the double pipe structure in which the flow path is formed,
(A) A compartmentalized inner pipe joined by welding at the inner pipe joint,
(B) A pair of supports arranged so as to surround the inner pipe on the upstream side and the downstream side of the inner pipe joint in the flow direction of the first fluid.
(C) A positioning member arranged so as to surround the inner pipe on the inner pipe joint side of each support in the second flow path and positioning each support, and a positioning member.
(D) An outer pipe for positioning each support on the upstream side and the downstream side of each support in the flow direction of the first fluid, and
(E) It has a tubular shape, is arranged so as to surround each of the supports and each outer pipe of each division, and is joined to each outer pipe of each division by welding to make the space inward in the radial direction airtight. With a sleeve to
(F) A double-tube structure characterized in that each of the supports is integrally formed of a resin, has an annular shape, and has a communication hole through which a second fluid passes. An inner pipe and an outer pipe are provided, a first flow path for passing a first fluid is formed in the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe. In the support arranged in the second flow path in the double pipe structure in which the flow path is formed and integrally formed by the resin,
(A) The first ring and
(B) A second annular body formed at a predetermined distance from the first annular body in the radial direction outward from the first annular body.
(C) It has connecting portions for connecting the first and second annular bodies at a plurality of locations in the circumferential direction, and also has
(D) A support characterized in that a holding portion for holding the outer pipe in a predetermined position is formed at a predetermined portion. An inner pipe and an outer pipe are provided, a first flow path for passing a first fluid is formed in the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe. In the method of forming a double pipe structure in which a flow path is formed,
(A) A support that is integrally formed of resin, has an annular shape, and has a communication hole for passing a second fluid is fitted onto the inner pipe.
(B) The support is sandwiched by the outer compartment pipes arranged on the upstream side and the downstream side of the support in the flow direction of the first fluid.
(C) A sleeve having a tubular shape is fitted onto the support and each outer pipe of each division by welding, and the inner space in the radial direction is made airtight. How to form a double-tube structure. An inner pipe and an outer pipe are provided, a first flow path for passing a first fluid is formed in the inner pipe, and a second flow path for passing a second fluid is formed between the inner pipe and the outer pipe. In the method of forming a double pipe structure in which a flow path is formed,
(A) At the inner pipe joint, the inner pipes are joined by welding.
(B) A pair of supports are fitted onto the inner pipe on one end side and the other end side of the inner pipe from the inner pipe joint.
(C) Each support is positioned by a positioning member on the inner pipe joint side of each support in the second flow path.
(D) Each support is positioned by the outer section pipe on one end side and the other end side of the inner pipe from each support in the second flow path.
(E) A sleeve having a tubular shape is externally fitted to each of the supports and each outer pipe of each division, and is joined to each outer pipe of each division by welding to make the space inward in the radial direction airtight.
(F) A method for forming a double-tube structure, wherein each support is integrally formed of a resin, has an annular shape, and has a communication hole through which a second fluid passes.

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