Connection structure between vacuum double piping and fluid equipment

Abstract

To provide a connection structure between a vacuum double pipe and a fluid device that allows maintenance of the fluid device connected to the vacuum double pipe to be quickly performed.SOLUTION: A connection structure between a vacuum double pipe 1 and a fluid device 100 is provided. The vacuum double pipe 1 comprises an inner pipe 10 through which a low-temperature fluid is passed, and an outer pipe 20 covering the inner pipe 10. A vacuum layer 30 is formed between the inner pipe 10 and the outer pipe 20. In the vacuum layer 30, an isolation part 33 is formed between an upstream side partition wall member 32a and a downstream side partition wall member 32b provided along a flow passage. The isolation part 33 is allowed to communicate with a portion of the vacuum layer 30 other than the isolation part 33 by bypass flow passages 34a and 34b comprising opening / closing valves 35a and 35b. In the isolation part 33, the fluid device 100 is provided in the inner pipe 10, and at least a portion of the outer pipe 20 is detachably constituted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a connection structure between a vacuum double pipe and a fluid device.

Background Art

[0002] Conventionally, a vacuum double pipe in which a vacuum layer is formed between an inner pipe through which a cryogenic fluid such as liquefied hydrogen passes and an outer pipe covering the inner pipe has been used to transport the cryogenic fluid. In some cases, fluid devices such as valves are connected to the vacuum double pipe, and Patent Document 1 discloses a vacuum-insulated valve that opens and closes the flow path of the cryogenic fluid transported by such a vacuum double pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vacuum-insulated valve disclosed in Patent Document 1 described above is connected to the vacuum double pipe by screwing, and can be removed from the vacuum double pipe during maintenance.

[0005] However, since the vacuum layer of the vacuum double pipe is opened to the atmosphere by this, there is a problem that it takes time to return the vacuum layer to the original vacuum state at the end of maintenance.

[0006] Therefore, an object of the present invention is to provide a connection structure between a vacuum double pipe and a fluid device that can perform maintenance of the fluid device connected to the vacuum double pipe quickly and easily.

Means for Solving the Problems

[0007] The object of the present invention is a connection structure between a vacuum double-walled pipe and a fluid device, wherein the vacuum double-walled pipe comprises an inner pipe through which a low-temperature fluid passes and an outer pipe covering the inner pipe, a vacuum layer is formed between the inner pipe and the outer pipe, the vacuum layer has an isolation section formed between an upstream partition member and a downstream partition member provided along the flow path, and the isolation section can communicate with the rest of the vacuum layer via a bypass flow path having an on / off valve. The outer tube comprises a cover portion that encloses the fluid device, and an upstream portion and a downstream portion that are airtightly flange-coupled to the upstream and downstream sides of the cover portion, respectively, and the fluid device is a valve, with a valve stem extending outward through the cover portion. In the isolation section, the fluid device is provided in the inner tube, 、 The outer tube The downstream portion Part of it is configured to be removable There are This is achieved through a connection structure between vacuum double piping and fluid equipment. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a connection structure between a vacuum double-walled piping and fluid equipment that allows for quick and easy maintenance of fluid equipment connected to the vacuum double-walled piping. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing a connection structure between a vacuum double-walled pipe and fluid equipment according to one embodiment of the present invention. [Figure 2] Figure 1 shows the main components of the vacuum double piping system, with (a) being a front view and (b) being a side view. [Figure 3] This is a cross-sectional view showing a portion of the vacuum double-walled piping shown in Figure 1 with a section removed. [Figure 4] Figure 1 is a cross-sectional view showing other key parts of the vacuum double-walled piping system. [Figure 5] Figure 4 is a front view of the main part. [Figure 6] This figure shows a modified version of the main part shown in Figure 1. [Figure 7] This is a cross-sectional view showing a connection structure between a vacuum double piping system and fluid equipment according to another embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Figure 1 is a cross-sectional view showing the connection structure between a vacuum double-walled pipe 1 and a fluid device 100 according to an embodiment of the present invention. As shown in Figure 1, the vacuum double-walled pipe 1 comprises an inner pipe 10 and an outer pipe 20 made of a metal material such as stainless steel, and a low-temperature fluid such as liquefied hydrogen, liquefied ammonia, liquefied helium, liquefied nitrogen, or liquefied oxygen passes through the inside of the inner pipe 10 in the direction of arrow F.

[0013] The outer tube 20 is positioned concentrically with the inner tube 10 so as to cover it, and a vacuum layer 30 is formed between the inner tube 10 and the outer tube 20. The vacuum layer 30 is evacuated by a vacuum pump (not shown) to vacuum-insulate the inner tube 10.

[0014] The fluid device 100 is a valve and comprises a valve body 102, a valve element 104 disposed within the valve body 102, and a valve stem 106 that rotatably supports the valve element 104. The upstream and downstream sides of the valve body 102 are airtightly flange-connected to the upstream portion 10a and the downstream portion 10b of the inner pipe 10 with fasteners such as bolts and nuts, and the flow path of the inner pipe 10 can be opened and closed by rotating the valve element 104 around the valve stem 106.

[0015] The upstream portion 10a and the downstream portion 10b of the inner pipe 10 are divided into first portions 11a, 11b, second portions 12a, 12b, and third portions 13a, 13b, in that order from the fluid equipment 100 side, and these are airtightly flange-connected to each other.

[0016] The outer tube 20 comprises a cover portion 29 that covers the fluid device 100, and an upstream portion 20a and a downstream portion 20b that are airtightly flange-coupled to the upstream and downstream sides of the cover portion 29, respectively. The valve stem 106 of the fluid device 100 extends outward through the cover portion 29.

[0017] The upstream portion 20a and the downstream portion 20b of the outer tube 20 are divided into a first portion 21a, 21b, a second portion 22a, 22b, and a third portion 23a, 23b in order from the cover portion 29 side. The first portion 21a, 21b, the second portion 22a, 22b, and the third portion 23a, 23b of the outer tube 20 are disposed at positions corresponding to the first portion 11a, 11b, the second portion 12a, 12b, and the third portion 13a, 13b of the inner tube 10, respectively.

[0018] On the upstream portions 10a, 20a of the inner tube 10 and the outer tube 20, an inner tube side mounting portion 14a and an outer tube side mounting portion 24a are provided, respectively. The inner tube side mounting portion 14a and the outer tube side mounting portion 24a are formed in a ring shape and are fixed by welding or the like to the outer peripheral surface of the second portion 12a and the inner peripheral surface of the second portion 22a, respectively, along the cross section of the vacuum double pipe 1.

[0019] The inner tube side mounting portion 14a and the outer tube side mounting portion 24a are arranged at intervals in the longitudinal direction of the inner tube 10 and the outer tube 20, and a bellows tube 31a that can expand and contract in the axial direction is attached between the inner tube side mounting portion 14a and the outer tube side mounting portion 24a. The inner tube side mounting portion 14a, the outer tube side mounting portion 24a, and the bellows tube 31a constitute an upstream side partition member 32a that blocks the vacuum layer 30 in the longitudinal direction of the inner tube 10 and the outer tube 20.

[0020] On the downstream portions 10b, 20b of the inner tube 10 and the outer tube 20, inner tube side mounting portions 14b and outer tube side mounting portions 24b are provided in the same manner as the upstream portions 10a, 20a, respectively. The inner tube side mounting portion 14b and the outer tube side mounting portion 24b are formed in a ring shape and are fixed by welding or the like to the outer peripheral surface of the second portion 12b and the inner peripheral surface of the second portion 22b, respectively, along the cross section of the vacuum double pipe 1.

[0021] The inner tube mounting portion 14b and the outer tube mounting portion 24b are spaced apart in the longitudinal direction of the inner tube 10 and the outer tube 20, and an axially expandable bellows tube 31b is installed between the inner tube mounting portion 14b and the outer tube mounting portion 24b. The inner tube mounting portion 14b, the outer tube mounting portion 24b and the bellows tube 31b constitute a downstream partition member 32b that blocks the vacuum layer 30 in the longitudinal direction of the inner tube 10 and the outer tube 20. An isolation portion 33 is formed between the upstream partition member 32a and the downstream partition member 32b of the vacuum layer 30, separating it from the rest of the vacuum layer 30.

[0022] A bypass channel 34a is formed in the upstream portion 20a of the outer tube 20 by piping that connects the upstream and downstream sides of the upstream partition member 32a in the vacuum layer 30. An on-off valve 35a is provided in the bypass channel 34a, and the bypass channel 34a can be opened and closed by operating the on-off valve 35a.

[0023] A bypass channel 34b is formed in the downstream portion 20b of the outer tube 20 by piping that connects the upstream and downstream sides of the downstream partition member 32b in the vacuum layer 30. An on-off valve 35b is provided in the bypass channel 34b, and the bypass channel 34b can be opened and closed by operating the on-off valve 35b.

[0024] Figure 2 shows the first portion 21b of the downstream portion 20b of the outer tube 20 shown in Figure 1, with Figure 2(a) being a front view and Figure 2(b) being a side view. As shown in Figures 2(a) and (b), the first portion 21b comprises a pair of semi-cylindrical divided bodies 25 and 26, which are combined to form a cylindrical shape. Both sides of the divided bodies 25 and 26 are provided with strip-shaped flange portions 251 and 261 extending in the axial direction. The flange portions 251 and 261 are airtightly connected to each other with fasteners such as bolts and nuts, and the divided bodies 25 and 26 can be removed in the radial direction indicated by the arrows by removing the fasteners.

[0025] The first portion 21a in the upstream portion 20a of the outer tube 20, the first portion 11a in the upstream portion 10a of the inner tube 10, and the first portion 11b in the downstream portion 10b of the inner tube 10 are also constructed by combining a pair of semi-cylindrical divided bodies 25 and 26 in a cylindrical shape, similar to the first portion 21b described above, and the divided bodies 25 and 26 can be removed radially.

[0026] The connection structure between the vacuum double piping 1 and the fluid equipment 100, which has the above configuration, allows the entire vacuum layer 30 to be connected by opening both the on-off valves 35a and 35b of the bypass passages 34a and 34b, and the entire vacuum layer 30 can be evacuated in the same way as conventional vacuum double piping.

[0027] On the other hand, during maintenance of the fluid equipment 100, closing both the on-off valves 35a and 35b isolates the isolation section 33 from the rest of the vacuum layer 30. After this, by removing the pair of divided parts 25 and 26 (see Figure 2) of the first part 21b in the downstream portion 20b of the outer tube 20 and the first part 11b in the downstream portion 10b of the inner tube 10 in the radial direction, a maintenance space M for performing maintenance on the fluid equipment 100 can be formed downstream of the fluid equipment 100, as shown in Figure 3.

[0028] The formation of the maintenance space M opens the isolation section 33 of the vacuum layer 30 to the atmosphere, but the parts of the vacuum layer 30 other than the isolation section 33 (the parts with the dot pattern) maintain a vacuum state. After maintenance is complete, the maintenance space M is returned to the state shown in Figure 1, and the on-off valves 35a and 35b of the bypass passages 34a and 34b are both opened to perform vacuuming, thereby creating a vacuum state throughout the vacuum layer 30.

[0029] According to the connection structure between the vacuum double piping 1 and the fluid equipment 100 of this embodiment, when performing maintenance on the fluid equipment 100, the release of the vacuum layer 30 into the atmosphere is limited to a partial extent, allowing the vacuum layer 30 to be returned to its original vacuum state in a short time after the maintenance is completed. Therefore, maintenance of the fluid equipment 100 connected to the vacuum double piping 1 can be performed quickly and easily.

[0030] In this embodiment, the first portion 21a in the upstream portion 20a of the outer pipe 20 and the first portion 11a in the upstream portion 10a of the inner pipe 10 are also composed of a pair of divided parts 25 and 26 as shown in Figure 2, so that a maintenance space can be formed on the upstream side of the fluid equipment 100. However, if a maintenance space on the upstream side of the fluid equipment 100 is not required, the first portions 11a and 21a may be configured to be indivisible.

[0031] The maintenance space for performing maintenance on the fluid equipment 100 can be created by making at least a portion of the outer tube 20 removable. In addition to the configuration of this embodiment, it can also be created, for example, by making an opening formed in the outer tube 20 so that it can be opened and closed with a cover.

[0032] The connection points of the bypass channels 34a and 34b to the outer tube 20 are not particularly limited as long as the isolation section 33 can communicate with other parts of the vacuum layer 30. However, in this embodiment, as shown in Figure 1, both ends of the upstream bypass channel 34a are connected to the first section 21a and the second section 22a, and both ends of the downstream bypass channel 34b are connected to the second section 22b. Instead of providing the downstream bypass channel 34b, the upstream bypass channel 34a may be branched and connected to the downstream side of the isolation section 33.

[0033] The upstream partition member 32a and the downstream partition member 32b that form the isolation section 33 only need to be configured to airtightly separate the vacuum layer 30, and may, for example, be ring-shaped partition members interposed when forming the inner tube 10 and the outer tube 20 by flange coupling. However, since the inner tube 10 expands and contracts due to temperature changes of the low-temperature fluid passing through it, the upstream partition member 32a and the downstream partition member 32b in this embodiment are supported by both the inner tube 10 and the outer tube 20 so that they can expand and contract in the longitudinal direction of the vacuum double pipe 1 by providing bellows tubes 31a and 31b, and further expand and contract in the radial direction of the vacuum double pipe 1 as will be described later.

[0034] The bellows tube 31a of the upstream partition member 32a shown in Figure 1 is equipped with a mounting ring 36a at the opening edge of one downstream end. The upstream side of the bellows tube 31a is directly attached to the inner tube mounting portion 14a, while the downstream side of the bellows tube 31a is attached to the outer tube mounting portion 24a via the mounting ring 36a.

[0035] Figure 4 is a cross-sectional view showing the main part of the upstream partition member 32a shown in Figure 1. As shown in Figure 4, the mounting ring 36a has an elongated hole 37a that extends in the radial direction, and by inserting a bolt 38 through the elongated hole 37a and screwing it into the threaded hole of the outer pipe side mounting portion 24a, the mounting ring 36a is supported so as to be radially movable relative to the outer pipe side mounting portion 24a. As shown in the front view in Figure 5, the elongated holes 37a of the mounting ring 36a are arranged in a balanced manner in the circumferential direction so that multiple holes face each other with the center in between.

[0036] The downstream partition member 32b, like the upstream partition member 32a, is equipped with a mounting ring 36b at the opening edge of one upstream end of the bellows tube 31b, and is configured to be expandable and contractible in the radial and longitudinal directions of the vacuum double piping 1.

[0037] Figure 6 shows a modified example of the main part of the upstream partition member 32a shown in Figure 1, in which mounting rings 36a, 36a are provided at the opening edges at both ends of the bellows tube 31a, respectively. Each mounting ring 36a has a plurality of elongated holes 37a extending in the radial direction, and these elongated holes 37a are used to attach it to the inner tube side mounting portion 14a and the outer tube side mounting portion 24a.

[0038] Figure 7 is a cross-sectional view showing a connection structure between a vacuum double-walled pipe 1 and a fluid device 100 according to another embodiment of the present invention, and shows other modifications of the upstream partition member 32a and the downstream partition member 32b. The upstream partition member 32a and the downstream partition member 32b shown in Figure 7 consist of a bent member formed in a ring shape, with a radial central portion 39 bent so as to protrude in the axial direction of the vacuum double-walled pipe 1. The inner and outer peripheral edges of this bent member are held between the inner pipe 10 and the outer pipe 20 when flange-connected, and are supported by the inner pipe 10 and the outer pipe 20. The upstream partition member 32a and the downstream partition member 32b configured in this way can also expand and contract in the radial and longitudinal directions of the vacuum double-walled pipe 1.

[0039] The configuration of the fluid equipment 100 to which the vacuum double piping 1 is connected is not particularly limited. For example, as shown in Figure 7, if a maintenance hole 108 for performing maintenance inside the valve body 102 is provided downstream of the valve body 102, the maintenance cover 109 of the maintenance hole 108 can be opened and closed by making at least the portion U directly above the maintenance hole 108 of the outer pipe 20 removable. Furthermore, the fluid equipment 100 is not necessarily limited to valves, as long as it is one of various fluid equipment through which low-temperature fluid passes, is supplied, or is discharged. For example, it may be a flow meter, pump, accumulator, tank, heat exchanger, etc. [Explanation of symbols]

[0040] 1 Vacuum double piping 10 Inner tube 14a, 14b Inner pipe side mounting section 20 outer tube 24a, 24b Outer tube side mounting part 25,26 split field 30 vacuum layer 31a, 31b Bellows tube 32a Upstream partition member 32b Downstream partition member 33 Isolation section 34a, 34b Bypass channel 35a, 35b Shut-off valves 36a, 36b Mounting rings 37a,37b long hole 100 Fluid equipment

Claims

1. A connection structure between a vacuum double-walled pipe and fluid equipment, The vacuum double-walled piping comprises an inner tube through which a low-temperature fluid passes and an outer tube covering the inner tube, with a vacuum layer formed between the inner tube and the outer tube. The vacuum layer has an isolation section formed between an upstream partition member and a downstream partition member provided along the flow path, and the isolation section can communicate with the rest of the vacuum layer via a bypass flow path having an on / off valve. The outer tube comprises a cover portion that covers the fluid device, and an upstream portion and a downstream portion that are airtightly flange-coupled to the upstream and downstream sides of the cover portion, respectively. The fluid device is a valve, and its valve stem extends outward through the cover portion. A connection structure between a vacuum double-walled pipe and a fluid device, wherein the fluid device is provided in the inner pipe in the isolation section, and a portion of the downstream part of the outer pipe is configured to be removable.

2. The downstream portion of the outer tube is provided with a first portion that is connected to the cover portion in the isolation portion, The connection structure between a vacuum double piping and fluid equipment according to claim 1, wherein the first portion of the downstream portion of the outer pipe is formed by combining a pair of semi-cylindrical divided bodies in a cylindrical shape, and the divided bodies can be removed in the radial direction.

3. The inner tube comprises an upstream portion and a downstream portion that are airtightly flange-coupled to the upstream and downstream sides of the valve body of the fluid device, respectively. The downstream portion of the inner tube is provided with a first portion that is connected to the fluid device at a position corresponding to the first portion of the downstream portion of the outer tube, The connection structure between a vacuum double piping and fluid equipment according to claim 2, wherein the first portion of the downstream side of the inner pipe is formed by combining a pair of semi-cylindrical divided bodies in a cylindrical shape, and the divided bodies can be removed in the radial direction.

4. The connection structure between a vacuum double piping and a fluid device according to claim 1 or 2, wherein the inner pipe is provided with a maintenance hole on the downstream side of the valve body of the fluid device for performing maintenance inside the valve body, and the maintenance cover of the maintenance hole can be opened and closed by removing a part of the downstream portion of the outer pipe.

5. The connection structure between a vacuum double pipe and a fluid device according to any one of claims 1 to 4, wherein the upstream partition member and the downstream partition member are supported on both the inner pipe and the outer pipe, respectively, so as to be expandable and contractible in the radial and longitudinal directions of the vacuum double pipe.

6. A method for maintaining a valve connected to a vacuum double piping, The vacuum double-walled piping comprises an inner tube through which a low-temperature fluid passes and an outer tube covering the inner tube, with a vacuum layer formed between the inner tube and the outer tube. The vacuum layer has an isolation section formed between an upstream partition member and a downstream partition member provided along the flow path, and the isolation section can communicate with the rest of the vacuum layer via a bypass flow path having an on / off valve. The outer tube comprises a cover portion that covers the valve, and an upstream portion and a downstream portion that are airtightly flange-coupled to the upstream and downstream sides of the cover portion, respectively. The valve has a valve stem that extends outward through the cover portion. In the isolation section, the valve is provided in the inner pipe, and a portion of the downstream part of the outer pipe is configured to be removable. A maintenance method for a valve connected to a vacuum double-walled piping system, comprising the steps of: closing the on-off valve to isolate the isolation portion from the portion of the vacuum layer other than the isolation portion; and then removing a portion of the downstream portion of the outer pipe during maintenance.

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