WO2024135420A1

WO2024135420A1 - Low-temperature fluid transport piping cover device

Info

Publication number: WO2024135420A1
Application number: PCT/JP2023/044104
Authority: WO
Inventors: 健太郎神山; 博理眞▲崎▼; 祐大塚本
Original assignee: 川崎重工業株式会社
Priority date: 2022-12-20
Filing date: 2023-12-08
Publication date: 2024-06-27
Also published as: TW202432986A

Abstract

This low-temperature fluid transport piping cover device is a cover device attached to piping for transporting a low-temperature fluid that can liquefy surrounding fluids, and comprises a cover having a cylindrical inner wall surface disposed, around a vertical piping portion extending in an up-down direction of the piping, at a predetermined distance from an outer peripheral surface of the vertical piping portion; and a support body that supports the cover. The cover includes an upper end at which an opening is formed by setting the distance between the inner wall surface and the outer peripheral surface of the vertical piping portion to a first distance, and a lower end at which an opening is formed by setting the distance to a second distance.

Description

Cover device for cryogenic fluid transport piping

This disclosure relates to a cover device that is attached to a pipe that transports a low-temperature fluid such as liquefied hydrogen.

The insulated piping disclosed in Patent Document 1 is known as an example of hydrogen piping for transporting liquefied hydrogen, which has a boiling point of -253°C at normal pressure. The piping in Patent Document 1 has a vacuum double-pipe structure with inner and outer tubes arranged concentrically and a vacuum layer between them. The insulating effect of the vacuum layer keeps the temperature of the liquefied hydrogen being transported below its boiling point.

If the degree of vacuum in the insulation layer of the above-mentioned vacuum double pipe drops for some reason, air may condense on the surface of the outer pipe, generating liquefied air. Furthermore, in plants that handle liquefied hydrogen, liquefied hydrogen may flow through piping that does not have a vacuum double pipe structure. In this case, liquefied air may also generate on the surface of the piping. For horizontal piping sections that extend horizontally in hydrogen piping, one solution is to place a tray under the horizontal piping section to receive the liquefied air. On the other hand, for vertical piping sections that extend vertically, the problem is the scattering of liquefied air from the vertical piping section. If liquefied air scatters, it can cause problems such as low-temperature embrittlement of surrounding structures.

JP 2017-20914 A

The objective of this disclosure is to provide a cover device for cryogenic fluid transport piping that can prevent liquefied gas from scattering into the surroundings even when liquefied gas is generated in the vertical piping section of a cryogenic fluid transport piping that can liquefy surrounding gas, such as a hydrogen piping.

A cover device for a low-temperature fluid transport pipe according to one aspect of the present disclosure is a cover device attached to a pipe that transports a low-temperature fluid capable of liquefying a surrounding fluid, and includes a cover having a cylindrical inner wall surface arranged around a vertical pipe section extending in the vertical direction in the pipe at a predetermined distance from the outer peripheral surface of the vertical pipe section, and a support body that supports the cover, and the cover includes an upper portion in which the distance between the inner wall surface and the outer peripheral surface of the vertical pipe section is set to a first distance, and a lower portion in which the distance is set to a second distance narrower than the first distance.

According to the present disclosure, a cover device for a cryogenic fluid transport pipe can be provided that can prevent liquefied gas from scattering into the surrounding area even if liquefied gas is generated in the vertical pipe section of the cryogenic fluid transport pipe.

FIG. 1 is a partially cutaway side view showing a hydrogen piping cover device according to one embodiment of the present disclosure. FIG. 2(A) is a schematic diagram showing the generation of liquefied air in a vertical piping section of hydrogen piping, and FIG. 2(B) is a schematic diagram showing the suppression of scattering of liquefied air by attaching the cover device of FIG. 1 to the vertical piping section. FIG. 3 is a plan view and a side view showing a specific embodiment of a cover device. FIG. 4 is a plan view and a side view of a specific embodiment of a cover device, which is rotated 90 degrees from FIG. FIG. 5 is an exploded perspective view of the cover of the cover device shown in FIGS. FIG. 6 shows plan and side views of the components of the cover assembly. FIG. 7 is a partially cutaway side view showing an embodiment in which the cover device of the present disclosure is applied to a hydrogen pipe including upper and lower horizontal pipe sections. 8A to 8C are schematic diagrams showing modified examples of the cover. FIG. 9 is a schematic diagram showing another modified example of the cover.

Below, with reference to the drawings, an embodiment of a cover device for a cryogenic fluid transport pipe according to the present disclosure will be described in detail. The pipe to which the cover device of the present disclosure is attached is a pipe that transports an extremely low temperature fluid that liquefies the surrounding gas and has a vertical pipe section. One example of such a pipe is a hydrogen pipe that may carry hydrogen gas with an extremely low temperature cold that liquefies liquefying liquefied hydrogen or air (oxygen, nitrogen), and has a vertical pipe section extending in the vertical direction. In the embodiment described below, a hydrogen pipe is exemplified. Examples of hydrogen pipes include pipes used in plants that handle liquefied hydrogen, and include pipes with a single-layer pipe structure without a vacuum insulation layer (single pipe), double pipes with a coaxial double pipe structure, and pipes with an insulation layer around a single pipe.

[Typical examples and functions of protective devices]
1 is a partially cutaway side view showing a cover device 2 for a hydrogen pipe 1 according to an embodiment of the present disclosure. As described above, the hydrogen pipe 1 is a pipe through which liquefied hydrogen or cryogenic hydrogen gas flows. The hydrogen pipe 1 has a vertical pipe section 11 extending in the vertical direction. The cover device 2 includes a cylindrical cover 3 disposed so as to surround the periphery of the vertical pipe section 11, and a support body 4 that supports the cover 3.

The cover 3 has a cylindrical inner wall surface 3S that is disposed at a predetermined distance from the outer peripheral surface 11S of the vertical piping section 11. There are no particular limitations on the material of the cover 3, but it is preferable that it be made of a metal that does not become brittle even when it comes into contact with liquefied air. In addition, it is preferable that the cover 3 be constructed as an assembly of divided pieces divided in the circumferential direction so that it can be retrofitted to the vertical piping section 11, and it can be constructed, for example, as a half piece or as in the embodiment described below, as a four-piece piece. Furthermore, the cover 3 may be constructed of a curved metal plate, but it may also be constructed of a cylinder formed of aggregate arranged around the vertical piping section 11 and a metal sheet wrapped around the outer peripheral surface of the aggregate.

The cover 3 is composed of a cylindrical upper part 31 and a lower part 32 that is connected to the lower end of the upper part 31 and has a truncated cone shape with a diameter that decreases downward. The upper end 33 of the cover 3 opens upward, and the lower end 34 opens downward. The cylindrical upper part 31 is arranged concentrically with the vertical piping section 11. In the upper part 31, the distance between the inner wall surface 3S and the outer circumferential surface 11S is set to a predetermined first distance d1. Since the upper part 31 is a cylinder, the upper end 33 forms an opening with a distance of first distance d1 between the inner wall surface 3S and the outer circumferential surface of the vertical piping section 11. The upper part 31 may be arranged slightly eccentrically with respect to the vertical piping section 11.

In the lower portion 32, the inner wall surface 3S has a tapered shape in which the distance between the inner wall surface 3S and the outer peripheral surface 11S gradually decreases toward the bottom. The lower portion 32 is also arranged concentrically with the vertical piping section 11. In the lower portion 32, the distance between the inner wall surface 3S and the outer peripheral surface 11S is generally narrower than the first distance d1, and the distance at the lower end portion 34 is set to a predetermined second distance d2 (d1>d2). In other words, the distance between the inner wall surface 3S and the outer peripheral surface 11S in the lower portion 32 gradually narrows downward from the first distance d1 to the second distance d2. At the lower end portion 34, the distance between the inner wall surface 3S and the outer peripheral surface of the vertical piping section 11 forms an opening with the second distance d2.

In FIG. 1, an example is shown in which the cylindrical cover 3 is arranged concentrically with the vertical piping section 11, but the cover 3 does not necessarily have to be cylindrical or truncated cone shaped. For example, the upper part 31 may be shaped like a polygonal prism, and the lower part 32 may be shaped like a polygonal pyramid. In this case, the first distance d1 and the second distance d2 cannot be made uniform in the circumferential direction of the outer circumferential surface 11S, but the prismatic cover 3 may be assembled so that its axis approximately coincides with the axis of the vertical piping section 11. In addition, if there is a bias in the direction in which the liquefied air scatters in the vertical piping section 11, an elliptical cover 3 may be used whose major axis is aligned with the direction in which the degree of scattering is greatest.

The support body 4 includes a clamp portion 41 and a support portion 42. The clamp portion 41 is a ring-shaped fastener attached to the outer peripheral surface 11S of the vertical pipe portion 11. The clamp portion 41 is a member that can be retrofitted to the vertical pipe portion 11, and is fixed to the outer peripheral surface 11S by applying a fastening force such as bolting. The support portion 42 is a member that directly supports the cover 3, and is formed, for example, of an arm or an annular piece. The base end side of the support portion 42 is connected to the clamp portion 41, and the tip side engages with the cover 3. There are no particular limitations on the manner of this engagement, and examples include screwing, fitting, and welding.

As a modified example, the cover 3 may be supported by another structure arranged near the hydrogen piping 1. Also, the base end of the support portion 42 may be directly welded to the outer circumferential surface 11S without using the clamp portion 41. Compared to these modified examples, the embodiment of FIG. 1 has a structure in which the vertical piping portion 11 itself supports the cover 3 via the clamp portion 41. Therefore, the support structure for the cover 3 can be simplified compared to when the cover 3 is supported by another structure. Also, because the support body 4 has a support structure by clamping, it has the advantage that it can be easily retrofitted to the vertical piping portion 11 without the need for welding or other work.

Fig. 2(A) is a schematic diagram showing the generation of liquefied air LA in hydrogen piping 1 arranged, for example, in a plant that handles liquefied hydrogen. The hydrogen piping 1 includes a vertical piping section 11 that extends vertically and a horizontal piping section 12 that extends horizontally from the lower end of the vertical piping section 11. A liquid receiving tray 13 is arranged below the horizontal piping section 12.

When liquefied hydrogen or cryogenic hydrogen gas flows through the hydrogen pipe 1 that does not have a vacuum insulation structure, the pipe surface temperature of the hydrogen pipe 1 becomes a temperature below the boiling point of air. Therefore, the air that comes into contact with the hydrogen pipe 1 is cooled and liquefied, and liquefied air LA is generated on the surface of the hydrogen pipe 1. Figure 2 (A) particularly shows the generation of liquefied air LA in the vertical pipe section 11. The liquefied air LA generated in the vertical pipe section 11 generally hangs down along the surface of the vertical pipe section 11 due to gravity and is received by the liquid receiving tray 13. Although not shown in the figure, the liquefied air LA generated in the horizontal pipe section 12 is also received by the liquid receiving tray 13. However, some of the liquefied air LA generated in the vertical pipe section 11 may behave in a manner that jumps outward in the radial direction of the vertical pipe section 11, as shown by the arrow a1 in the figure. In other words, some of the liquefied air LA may not fall along the vertical pipe section 11 and may scatter to the surroundings without being received by the liquid receiving tray 13. In this case, various problems can occur, such as low-temperature embrittlement of surrounding structures.

FIG. 2(B) is a schematic diagram showing how the scattering of liquefied air LA is suppressed when the cover device 2 of FIG. 1 is attached to the vertical piping section 11. In this case, the presence of a cover around the vertical piping section 11 suppresses the scattering of liquefied air LA. In other words, since the outer peripheral surface 11S of the vertical piping section 11 is surrounded by the cover 3, even if the liquefied air LA splashes as indicated by arrow a1, it is received by the inner wall surface 3S of the cover 3 and prevented from scattering. The liquefied air LA that hits the inner wall surface 3S is returned to the outer peripheral surface 11S as indicated by arrow a2, or hangs down along the inner wall surface 3S. In other words, the splashed liquefied air LA is trapped inside the cover 3.

The cover 3 has a lower portion 32 that tapers downward. Therefore, the liquefied air LA trapped inside the cover 3 can be directed toward the outer circumferential surface 11S at the lower portion 32. That is, the lower portion 32 has a tapered inner wall surface 3S, and the liquefied air LA present between the upper portion 31 and the outer circumferential surface 11S, or the liquefied air LA hanging down along the inner wall surface 3S of the cover 3, can be guided toward the outer circumferential surface 11S, and can be guided along the outer circumferential surface 11S at least at the lower end portion 34. Therefore, as shown by the arrow a3, the liquefied air LA generated in the vertical piping portion 11 can be caused to hang down by gravity along the outer circumferential surface 11S of the vertical piping portion 11 and can be received by the liquid receiving tray 13. This makes it possible to prevent the liquefied air LA from scattering and to recover it.

[Specific example of cover device]
A schematic example of the cover device 2 is shown in Fig. 1. Next, a specific example of the cover device 2 will be shown. Fig. 3 shows a specific embodiment of the cover device 2, with the upper figure being a plan view and the lower figure being a side view. Fig. 4 shows a plan view and a side view of the cover device 2, which are rotated 90 degrees from Fig. 3. The cover device 2 comprises a cover 3A that covers the periphery of the vertical piping section 11, and a support body 4A that supports the cover 3A. The cover 3A is composed of a combination of a first member 5 and a second member 6.

Figure 5 is an exploded perspective view of the cover 3A shown in Figures 3 and 4, and the upper part of Figure 6 is a plan view of the support body 4A, the first member 5, and the second member 6, while the lower part is a side view of these. The support body 4A includes a clamp portion 41, a support portion 42, and a fastener 43. The clamp portion 41 consists of a pair of clamp pieces, each of which has a semicircular arc piece 411 with an inner diameter that matches the outer diameter of the vertical piping section 11, and flange portions 412 extending from both end edges of the arc piece 411. Each arc piece 411 of the clamp pieces is fitted into the outer peripheral surface of the vertical piping section 11, and is assembled to the vertical piping section 11 so that the flange portions 412 face each other.

In this embodiment, a bolt and nut are used as the fastener 43. A bolt hole for passing the bolt through is drilled in the flange portion 412. A fastening force is applied by the bolt and nut at the flange portion 412, and the clamp portion 41 is attached to the vertical piping portion 11 such that the pair of arc pieces 411 clamp the vertical piping portion 11. The fastener 43 may be one that utilizes spring force or one that is fastened using a wire or the like.

The support portion 42 is a plate-like piece that protrudes radially outward from the outer circumferential surface of the arc piece 411, and is the portion that actually supports the cover 3A. The protruding position of the support portion 42 is a position shifted by 90 degrees in the circumferential direction from the opposing center of the pair of flange portions 412. The support portion 42 includes a blade portion 421 and a fixing screw 422. In this embodiment, an example is shown in which the blade portion 421 is a pair of plate materials arranged with a small gap (a gap that can accommodate the arm 52 described later). The blade portion 421 may be composed of a single plate. The blade portion 421 can be fixed to the arc piece 411 by, for example, welding. The fixing screw 422 is a fixing device for fixing the support portion 42 and the cover 3A.

The cover 3A is formed by combining a pair of cylindrical piece-shaped first members 5 directly supported by the support portion 42, and a pair of cylindrical piece-shaped second members 6 supported by the first members 5. The second members 6 are assembled to the first members 5 so as to be movable in the circumferential direction. This makes it possible to adjust the first distance d1 and the second distance d2, which are the distances between the inner wall surface 3S of the cover 3A and the outer peripheral surface 11S of the vertical piping section 11 shown in FIG. 1. Here, an example is shown in which both d1 and d2 are adjustable, but it is also possible to make only one of d1 and d2 adjustable.

The pair of first members 5 are made of a relatively rigid metal, and each includes a first cylindrical piece 51, an arm 52, an upper guide screw 53, and a lower guide screw 54 (adjustment mechanism). The first cylindrical piece 51 includes a tube portion 511 that corresponds to the upper portion 31 in the example of FIG. 1, and a tapered portion 512 that corresponds to the lower portion 32. The tube portion 511 has a constant inner diameter in the vertical direction. The tapered portion 512 is connected to the lower end of the tube portion 511, and the inner diameter gradually decreases downward. The tube portion 511 and tapered portion 512 of each of the pair of first members 5 have a circumferential length of approximately 1/3 arc length when viewed from above.

The arm 52 is a plate piece that protrudes radially inward from the circumferential center near the upper end of the tube portion 511. The first member 5 is supported by the support body 4A at the arm 52. As shown in FIG. 5, the arm 52 has a long hole 521 that is long in the radial direction. The fixing screw 422 provided on the support portion 42 of the support body 4A is inserted into the long hole 521. The arm 52 is fitted between the pair of plate materials of the blade portion 421, and the fixing screw 422 is inserted and fastened with the screw hole of the arm 52 and the long hole 521 aligned. This fastening results in a state in which the cover 3A is supported by the support body 4A. The first distance d1 and the second distance d2 described above can be adjusted by adjusting the relative positions of the long hole 521 and the fixing screw 422.

The upper guide screw 53 is attached near the upper end of the cylindrical portion 511, near both circumferential ends. A nut is attached to the upper guide screw 53. The lower guide screw 54 is attached near the lower end of the tapered portion 512, near both circumferential ends. A nut is also attached to the lower guide screw 54. The upper guide screw 53 and the lower guide screw 54 are parts for engaging the second member 6 with the first member 5 so that the second member 6 can slide freely in the circumferential direction.

The second member 6 is made of a material having a lower rigidity than the first member 5, for example, a flexible sheet metal, and includes a pair of second cylindrical pieces 61 and a pair of tapered pieces 62. In this embodiment, the second cylindrical piece 61 and the tapered piece 62 are separate bodies, but they may be one body. The second cylindrical piece 61 is a cylindrical piece having approximately the same inner diameter as the tube portion 511 of the first member 5, and is assembled so that both ends in the circumferential direction are in sliding contact with the tube portion 511. The tapered piece 62 has a truncated cone shape similar to the tapered portion 512, and is assembled so that both ends in the circumferential direction are in sliding contact with the tapered portion 512. The pair of second cylindrical pieces 61 and the tapered piece 62 each have a circumferential length of approximately 1/3 arc length when viewed from above.

A pair of upper slits 63 (adjustment mechanism) consisting of elongated holes in the circumferential direction are opened near the upper end of the second cylindrical piece 61. The pair of upper slits 63 are openings for guiding the pair of upper guide screws 53 attached to the tube portion 511 of the first cylindrical piece 51. With the upper guide screws 53 inserted into the upper slits 63, nuts are fastened to the upper guide screws 53, so that the second cylindrical piece 61 engages with the first cylindrical piece 51. In addition, a pair of lower slits 64 (adjustment mechanism) consisting of elongated holes in the circumferential direction are opened near the lower end of the tapered piece 62. The pair of lower slits 64 are openings for guiding the pair of lower guide screws 54 attached to the tapered portion 512 of the first member 5, so that the tapered piece 62 engages with the first cylindrical piece 51. With the lower guide screws 54 inserted into the lower slits 64, nuts are fastened to the lower guide screws 54, so that the tapered piece 62 engages with the first cylindrical piece 51.

The second cylindrical piece 61 is engaged with the tube portion 511 of the first cylindrical piece 51 to form a cylindrical portion with a constant inner diameter in the vertical direction. This cylindrical portion corresponds to the upper portion 31 in FIG. 1. The tapered piece 62 is engaged with the tapered portion 512 of the first cylindrical piece 51 to form a truncated cone portion whose inner diameter decreases toward the bottom. This truncated cone portion corresponds to the lower portion 32 in FIG. 1. Depending on the relative positions of the long hole 521 and the fixing screw 422 described above, the relative position of the upper guide screw 53 to the upper slit 63 and the relative position of the lower guide screw 54 to the lower slit 64 change. In other words, the fastening positions of the nuts of the guide screws 53 and 54 to the

slits

63 and 64 are adjusted depending on the set lengths of the first interval d1 and the second interval d2 described above.

According to the cover device 2 equipped with the cover 3A and support 4A described above, the first interval d1 and the second interval d2 can be adjusted to be enlarged or reduced by adjusting the positions of the long hole 521 of the arm 52 and the fixing screw 422 of the support 42, and the guide screws 53, 54 and the

slits

63, 64. Therefore, the cover 3A can be customized by adjusting the first interval d1 and the second interval d2 to suit the scattering conditions of the liquefied air LA from the vertical piping section 11 at the installation site of the hydrogen piping 1. This customization can also be achieved by simply sliding the second member 6 circumferentially relative to the first member 5, which provides excellent workability.

[Example of cover device deployment]
7 is a partially cutaway side view showing a cover device 2A applied to a hydrogen pipe 1A including upper and lower horizontal piping sections. The hydrogen pipe 1A includes a vertical pipe section 11, a first horizontal pipe section 12A that is continuous with the upper end of the vertical pipe section 11 and extends horizontally, and a second horizontal pipe section 12B that extends horizontally from the lower end of the vertical pipe section 11. The cover device 2A includes a cover 3, a support body 4, a liquid receiving tray 13, and an upper liquid receiving tray 14.

The upper liquid receiving tray 14 is disposed from below the first horizontal piping section 12A to the vertical piping section 11. As shown by the arrow b1 in FIG. 7, the upper liquid receiving tray 14 is a gutter that collects liquefied air generated in the first horizontal piping section 12A. The upper liquid receiving tray 14 has an extension 141 that extends further to the left than directly above the vertical piping section 11. The extension 141 is provided with a through hole 142 (opening) having an opening diameter larger than the outer diameter of the vertical piping section 11. A guide tube 143 consisting of a cylindrical protrusion extending downward is attached to the periphery of the through hole 142. The vertical piping section 11 is piped so as to pass through the through hole 142 and the guide tube 143. A gap is secured between the through hole 142 and the vertical piping section 11 to serve as a passage for the liquefied air. The liquid receiving tray 13 is disposed from the vertical piping section 11 to below the second horizontal piping section 12B, similar to the example shown in FIG. 2(B).

A cover 3 is attached to the vertical piping section 11 to prevent the scattering of liquefied air. The cover 3 and support 4 shown here are the same as the cover 3 and support 4 shown in Figures 1 and 2 (B), so a description is omitted. The gap G between the upper end 33 of the cover 3 and the vertical piping section 11 and the gap between the above-mentioned through hole 142 and the vertical piping section 11 are in a positional relationship facing each other in the vertical direction. The opening diameter at the lower end of the guide tube 143 is set smaller than the opening diameter at the upper end 33.

In Figure 7, arrows b1 to b5 indicate the recovery path of liquefied air when liquefied hydrogen flows through the hydrogen piping 1A and liquefied air is generated on the surface of the piping. The liquefied air generated in the first horizontal piping section 12A is recovered in the upper liquid receiving tray 14 (arrow b1). The liquefied air received in the upper liquid receiving tray 14 falls through the gap between the through hole 142 and the vertical piping section 11, as shown by arrow b2, and enters the inside of the cover 3 through gap G.

The liquefied air generated in the vertical piping section 11 hangs down along the vertical piping section 11 while being trapped inside the cover 3. Inside the cover 3, the liquefied air that has fallen from the through hole 142 joins with the liquefied air generated in the vertical piping section 11 to create a flow of liquefied air as indicated by arrow b3. This flow of liquefied air is guided toward the outer peripheral surface 11S of the vertical piping section 11 at the lower part 32 of the cover 3, which has a tapered shape. Then, as indicated by arrow b4, a flow of liquefied air is formed that flows along the outer peripheral surface 11S, and is received by the liquid receiving tray 13. The liquefied air generated in the second horizontal piping section 12B is also received by the liquid receiving tray 13 as indicated by arrow b5.

The liquefied air received by the liquid receiving tray 13 is processed in the recovery equipment (not shown). According to the embodiment of FIG. 7, not only can the cover 3 confine the liquefied air generated in the vertical piping section 11, but the liquefied air recovered in the upper liquid receiving tray 14 can be dropped into the cover 3 and transmitted to the vertical piping section 11. Therefore, it is possible to both recover the liquefied air from the upper liquid receiving tray 14 and prevent the liquefied air from scattering in the vertical piping section 11.

[Modifications of the cover]
The cover 3 of the cover device 2 can be modified in various ways as long as the above-mentioned relationship of first distance d1>second distance d2 is satisfied.

The cover 301 shown in FIG. 8(A) has an upper portion 31A that tapers downward and a lower portion 32A with a constant inner diameter. The cover 301 has a funnel shape that opens upward like a trumpet, so the generated liquefied air can be gradually directed toward the vertical piping section 11 at the upper portion 31A and along the vertical piping section 11 at the lower portion 32A. This cover 301 is useful, for example, in cases where liquefied air is scattered violently near the upper portion of the vertical piping section 11.

Cover 302 shown in FIG. 8(B) has a cylindrical upper portion 31B with a relatively large inner diameter and a cylindrical lower portion 32B with a relatively small inner diameter. In other words, cover 302 has a shape in which the inner diameter changes in a two-step type. Cover 302 may also have an inner diameter that changes in three or more steps.

The cover 303 shown in FIG. 8(C) has a shape in which an upper end tapered portion 35 is added to the cover 3 shown in FIG. 1 and FIG. 7. The upper end tapered portion 35 extends from the upper end of the upper portion 31 and has a tapered shape that widens upward. Since the cover 303 has the upper end tapered portion 35, the intake of liquefied air from the upper end opening of the cover 303 can be improved. Therefore, if the cover 303 is applied to the cover device 2A shown in FIG. 7, the liquefied air falling from the through hole 142 of the upper liquid receiving tray 14 can be taken into the cover 303 without leaking.

In the above-mentioned

covers

3, 3A, 301 to 303, the shape of the inner wall surface 3S and the outer shape are shown as examples in which they are approximately the same. However, as long as the inner wall surface 3S satisfies the above-mentioned d1>d2, the outer shape may be any shape. For example, in FIG. 1, the outer shape of the cover 3 may be cylindrical over its entire vertical length, and the shape of the inner wall surface 3S may be a shape having a cylindrical portion in the upper portion 31 and a tapered portion in the lower portion 32.

The cover 3 may be configured in such a way that the above-mentioned relationship of first distance d1 > second distance d2 is not satisfied. The cover 304 shown in FIG. 9 has an upper end 33A with a distance da from the outer peripheral surface of the vertical piping section 11, and a lower end 34A with a distance da from the outer peripheral surface of the vertical piping section 11. In other words, the cover 304 is made of a cylinder with a constant inner diameter. Such a cover 304 can also suppress the scattering of liquefied air from the vertical piping section 11 to the surroundings. Note that the relationship d1 < d2 may be satisfied as long as the difference between d1 and d2 is within a relatively small range.

[Summary of the Disclosure]
The specific embodiments described above include disclosures having the following configurations.

The cover device for a low-temperature fluid transport pipe according to the first aspect of the present disclosure is a cover device that is attached to a pipe that transports a low-temperature fluid that can liquefy the surrounding fluid, and includes a cover having a cylindrical inner wall surface that is arranged around a vertical pipe section that extends in the vertical direction in the pipe and is spaced a predetermined distance from the outer circumferential surface of the vertical pipe section, and a support body that supports the cover, and the cover includes an upper end that forms an opening in which the distance between the inner wall surface and the outer circumferential surface of the vertical pipe section is set to a first distance, and a lower end that forms an opening in which the distance is set to a second distance.

According to the first aspect, even if liquefied gas such as liquefied air (hereinafter referred to as liquefied air) is generated on the outer circumferential surface of the vertical piping section due to the flow of low-temperature fluid through the piping, the presence of a cover around the vertical piping section prevents the liquefied air from scattering.

The cover device for the low-temperature fluid transport pipe according to the second aspect is the cover device according to the first aspect, in which the second gap is narrower than the first gap.

According to the second aspect, the lower end has a narrower distance from the outer circumferential surface of the vertical piping than the upper end. This makes it easier to guide the liquefied air that is trapped inside the cover and moves downward due to gravity along the vertical piping at the lower end without scattering. In particular, the narrow width of the lower end of the cover makes it easier for the liquefied air to form a flow that travels along the surface of the vertical piping due to surface tension.

The cover device for low-temperature fluid transport piping according to the third aspect is the cover device of the second aspect, in which the inner wall surface at the lower part of the cover has a tapered shape in which the distance between the inner wall surface and the outer peripheral surface of the vertical piping section gradually decreases downward.

According to the third aspect, the inner wall surface of the lower part of the cover has a tapered shape that tapers downward. This makes it easier to direct the liquefied air trapped inside the cover toward the outer circumferential surface of the vertical piping at the lower part, and more reliably transmits the liquefied air to the vertical piping to prevent scattering.

The cover device for low-temperature fluid transport piping according to the fourth aspect is the cover device according to the first to third aspects, in which the support body has a clamp portion attached to the outer circumferential surface of the vertical piping section and a support portion that supports the cover.

According to the fourth aspect, the cover is supported by the vertical pipe section itself via the clamp section, which simplifies the support structure for the cover. In addition, because the support structure is by clamp, it has the advantage that it can be easily retrofitted to the vertical pipe section without the need for welding or other work.

The fifth aspect of the cover device for low-temperature fluid transport piping is the cover device of the first to third aspects, in which the cover is provided with an adjustment mechanism that can expand or reduce at least one of the first gap and the second gap.

According to the fifth aspect, by adjusting at least one of the first and second intervals, the cover can be customized to suit the conditions under which liquefied air is dispersed from the vertical piping at the site.

The sixth aspect of the cover device for low-temperature fluid transport piping is the cover device of the fourth aspect, in which the cover comprises a cylindrical piece-shaped first member supported by the support portion, and a cylindrical piece-shaped second member supported by the first member and movable circumferentially relative to the first member.

According to the sixth aspect, the first and second intervals can be easily adjusted by moving the second member in the circumferential direction. Therefore, the shape of the cover can be easily adjusted depending on the scattering condition of liquefied air in the vertical piping section at the site.

The seventh aspect of the cover device for low-temperature fluid transport piping is a cover device according to the first to sixth aspects, in which the piping has a horizontal piping section connected to the upper end of the vertical piping section, and further includes a liquid receiving tray arranged from below the horizontal piping section to above the vertical piping section, and the liquid receiving tray has an opening at a position facing the gap between the upper end of the cover and the vertical piping section.

According to the seventh aspect, the liquefied air received in the liquid receiving tray can be dropped into the cover and transmitted to the vertical piping section. This makes it possible to both recover the liquefied air from the liquid receiving tray and prevent the liquefied air from scattering in the vertical piping section.

[Explanation of symbols]
1 Hydrogen piping 11 Vertical piping section 11S Outer circumferential surface 12A First horizontal piping section (horizontal piping section)
14 Upper liquid receiving tray (liquid receiving tray)
142 Through hole (opening)
2,

2A Protective device

3, 3A Cover 3S Inner wall surface 31 Upper part 32 Lower part 4 Support body 41 Clamp part 42 Support part 5 First member 53 Upper guide screw (adjustment mechanism)
54 Lower guide screw (adjustment mechanism)
6 Second member 63 Upper slit (adjustment mechanism)
64 Lower slit (adjustment mechanism)
LA Liquefied air (liquefied gas)
d1 First distance d2 Second distance G Gap

Claims

A cover device to be attached to a pipe for transporting a cryogenic fluid capable of liquefying a surrounding fluid,
a cover having a cylindrical inner wall surface arranged around a vertical piping portion extending in the vertical direction of the piping and spaced a predetermined distance from an outer circumferential surface of the vertical piping portion;
A support body that supports the cover,
The cover device for a cryogenic fluid transport piping includes an upper end forming an opening where the distance between the inner wall surface and the outer peripheral surface of the vertical piping section is set to a first distance, and a lower end forming an opening where the distance is set to a second distance.
The cover device according to claim 1,
A cover device for a cryogenic fluid transport pipe, wherein the second interval is narrower than the first interval.
The cover device according to claim 2,
A cover device for a cryogenic fluid transport piping, wherein the inner wall surface at the lower part of the cover has a tapered shape in which the distance between the inner wall surface and the outer peripheral surface of the vertical piping section gradually decreases downward.
In the cover device according to any one of claims 1 to 3,
A cover device for a cryogenic fluid transport piping, wherein the support body has a clamp portion attached to an outer peripheral surface of the vertical piping portion and a support portion that supports the cover.
In the cover device according to any one of claims 1 to 3,
A cover device for a cryogenic fluid transport pipe, wherein the cover is provided with an adjustment mechanism capable of enlarging or reducing at least one of the first gap and the second gap.
The cover device according to claim 4,
The cover is
A cylindrical piece-shaped first member supported by the support portion;
A cover device for a cryogenic fluid transport pipe comprising: a second member having a cylindrical piece shape supported by the first member and movable circumferentially relative to the first member.
The cover device according to claim 1,
The piping has a horizontal piping section connected to an upper end of the vertical piping section,
The apparatus further includes a liquid receiving tray disposed from below the horizontal piping section to above the vertical piping section,
A cover device for a cryogenic fluid transport piping, wherein the liquid receiving tray has an opening at a position facing a gap between the upper end of the cover and the vertical piping section.