Pipe clamping device and pipe clamping method

Abstract

A pipe clamping implement (10) comprises: a pair of fixation members (11) that are each fixed to a side wall in an underground space, clamp a pipe, and are disposed so as to face each other; and a covering material (12) that is mounted between the pair of fixation members (11) and the pipe so as to cover the outer periphery of the pipe.

Description

Technical Field

[0001] The present disclosure relates to a pipe clamping device and a pipe clamping method.

Background Art

[0002] In recent years, aiming at decarbonization and towards the realization of carbon neutrality, in order to utilize hydrogen gas, methods for supplying hydrogen gas and safety in the supply of hydrogen gas have been studied (see Non-Patent Document 1).

[0003] Conventionally, hydrogen pipelines for supplying hydrogen gas were directly buried in the excavated ground. Therefore, when pumping hydrogen gas, due to the restraining force of the soil, no expansion or contraction occurred in the hydrogen pipes (hydrogen pipelines).

[0004] FIG. 8 is a diagram for explaining an example of a hydrogen pipeline laid via a plurality of underground spaces. Conventionally, in addition to those directly buried in the ground as described above, hydrogen pipelines laid via a plurality of underground spaces as shown in FIG. 8 have been introduced. The hydrogen pipes are laid in the empty pipeline inside an existing pipe connecting a plurality of underground spaces, and a hydrogen pipeline in which a plurality of hydrogen pipes are joined is constructed. In such a hydrogen pipeline, hydrogen gas is transported and supplied from a hydrogen tank on the supply side to a hydrogen tank on the demand side. Furthermore, in order to cope with unevenness (referring to the fact that the surface is not horizontal and has irregularities) in the pipeline of the existing pipe, curved construction inside the existing pipe or in the underground space, etc., a lightweight and highly flexible flexible pipe is adopted for the hydrogen pipe. The flexible pipe is composed of a stainless steel corrugated original pipe or the like, and is a lightweight and highly flexible pipe. In the underground space, fixtures are installed in the underground space to prevent the flexible pipe that flexibly expands and contracts from bending.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] However, in underground spaces without restraining forces such as soil, when hydrogen gas is pumped through a flexible pipe, the pressure of the hydrogen gas can cause the flexible pipe to expand, potentially leading to buckling. In the worst-case scenario, buckling of a flexible pipe can result in an explosion caused by a hole forming in the piping. Figure 9 illustrates the occurrence of buckling in a pipe after hydrogen gas is pumped. Buckling of a flexible pipe occurs because the pressure from the hydrogen gas pumping causes the flexible pipe to expand in the underground space. Buckling also occurs between the duct section and the underground space fixing section where the fixing device is installed. Buckling refers to a phenomenon where, when the load applied to a structure is increased, the deformation pattern suddenly changes at a certain load, resulting in a large deflection. Therefore, in underground spaces without restraining forces such as soil, suppressing buckling caused by the expansion of flexible pipes is a challenge.

[0007] In view of these circumstances, the object of the present invention is to suppress buckling of flexible pipes in underground spaces during gas pumping. [Means for solving the problem]

[0008] To solve the above problems, the pipe clamping device according to this embodiment is a pipe clamping device that suppresses buckling of a gas-conducting pipe in an underground space, and comprises a pair of opposing fixing members, each fixed to the side wall of the underground space and clamping the pipe, and a covering material that is attached between the pair of fixing members and the pipe and covers the outer circumference of the pipe.

[0009] To solve the above problems, the pipe clamping method according to this embodiment is a pipe clamping method that suppresses buckling of a gas-conducting pipe in an underground space, and includes the steps of: covering the outer circumference of the pipe with a covering material; clamping the covered pipe from both sides with a pair of fixing members; fixing each of the pair of fixing members to the side wall of the underground space; determining whether the gas pressure inside the pipe in the consumption tank, measured by a pressure gauge, is above a threshold; and determining that buckling of the pipe has occurred if the gas pressure falls below the threshold. [Effects of the Invention]

[0010] According to this disclosure, it is possible to prevent buckling by suppressing the elongation of the piping after gas is pumped. [Brief explanation of the drawing]

[0011] [Figure 1] This figure illustrates an example of a gas supply pipeline according to this embodiment. [Figure 2] This figure shows an example of the configuration of a pipe clamping device according to this embodiment. [Figure 3] This is a cross-sectional view of the pipe clamping device according to this embodiment. [Figure 4] This figure shows an example of the configuration of the fixing member according to this embodiment. [Figure 5] These are a front view, a top view, and a side view of the fixing member according to this embodiment. [Figure 6] This diagram shows the state of the piping before and after gas pumping. [Figure 7] This flowchart shows an example of a pipe clamping method that suppresses buckling of pipes according to this embodiment. [Figure 8] This diagram illustrates an example of a hydrogen pipeline laid through multiple underground spaces. [Figure 9] This diagram shows the buckling of the piping after hydrogen gas is pumped. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments and can be implemented in various modifications within the scope of its gist. Hereinafter, in these embodiments, hydrogen gas will be described as an example of the gas to be pumped, but the gas to be pumped is not limited to hydrogen gas.

[0013] <Gas supply pipeline> Figure 1 is a diagram illustrating an example of a gas supply pipeline 1 according to this embodiment. The gas supply pipeline 1 comprises a supply-side tank 2A, a consumption-side tank 2B, a pressure gauge 20, an underground space 3, piping 4, an existing pipe 5, a fixing device 6, and a duct section 7. The gas supply pipeline 1 transports and supplies gas (for example, hydrogen gas) stored in the supply-side tank 2A ​​installed above ground to the consumption-side tank 2B installed above ground, using the piping 4 laid via a plurality of underground spaces 3 connected by the existing pipe 5 as a transport pipeline.

[0014] The supply tank 2A ​​is a tank for storing gases such as hydrogen gas. The consumption tank 2B is a tank installed at the consumption site that stores the gas transported from the supply tank 2A ​​via the piping 4 as a transport pipeline. In this embodiment, the supply tank 2A ​​and the consumption tank 2B are described as being installed on the ground, but they are not limited to being installed on the ground.

[0015] The underground space 3 is a hollow space containing manholes, tunnel structures, handholes, etc. Duct openings 7 (hereinafter also referred to as duct sections 7) for drawing in or drawing out pipes 4 are provided on the side walls of the underground space 3, and pipe clamping devices 10 are fixed to the side walls near each duct section 7. Measures have been taken to prevent groundwater or other water from flowing into the underground space 3.

[0016] The pipe 4 is a pipeline for transporting gases such as hydrogen gas. The pipe 4 is laid between the supply-side tank 2A and the consumption-side tank 2B via the inside of a plurality of underground spaces 3 connected by an existing pipe 5. The pipe 4 is composed of, for example, a stainless steel corrugated original pipe, and a flexible pipe such as a flexible tube that is lightweight and highly flexible is used.

[0017] The existing pipe 5 is a pipeline that is installed in advance between two underground spaces 3. By accommodating the pipe 4 inside the existing pipe 5, a pipeline with a double-pipe structure is constructed.

[0018] The fixture 6 is installed at the underground space fixing part inside the underground space 3 to support and fix the pipe 4 in order to prevent the pipe 4 from sagging.

[0019] The duct part 7 is a duct opening that penetrates the wall surface of the underground space 3 for drawing in or drawing out the pipe 4.

[0020] The pressure gauges 20 (20A, 20B) measure the gas pressure inside the pipe 4 in the supply-side tank 2A and the consumption-side tank 2B. The gas pressures inside the pipe 4 in the supply-side tank 2A and the consumption-side tank 2B are compared. If the gas pressure inside the pipe 4 in the consumption-side tank 2B is equal to or higher than the threshold value, it is determined that the pipe 4 for pumping the gas is properly constructed. If the gas pressure inside the pipe 4 in the consumption-side tank 2B is below the threshold value, it is determined that buckling, which will be described later, has occurred in the pipe 4 inside the underground space 3. When it is determined that buckling has occurred in the pipe 4, the cause is investigated and the defective part is repaired.

[0021] <Pipe clamping device> Figure 2 is a diagram showing an example of the configuration of the pipe clamping device 10 according to this embodiment. Figure 3 is a cross-sectional view of the pipe clamping device 10 according to this embodiment. As shown in Figures 2 and 3, the pipe clamping device 10 comprises a pair of fixing members 11, a covering material 12, one or more bolts and nuts 13, and one or more anchor bolts 14. The pipe clamping device 10 suppresses buckling of the gas-conducting pipe 4 within the underground space 3. Hereinafter, one of the pair of fixing members 11 will be referred to as 11A and the other fixing member as 11B. When fixing members 11A and 11B are not distinguished, fixing members 11A and 11B will also be referred to as fixing member 11.

[0022] The pair of fixing members 11A and 11B are positioned opposite each other, sandwiching the pipe 4, and clamp the pipe 4 by tightening them from both sides with one or more bolts and nuts 13 (bolt 13A and nut 13B). Furthermore, by fixing the pair of fixing members 11A and 11B that clamp the pipe 4 to the side wall 3A of the underground space near the duct section 7 with one or more anchor bolts 14, it becomes possible to receive the force that the pipe 4 would try to extend over a surface area, thereby suppressing the extension of the pipe 4 within the underground space 3.

[0023] <Fixing components> Figure 4 shows an example of the configuration of the fixing member 11 according to this embodiment. Figure 5 shows a front view, a top view, and a side view of the fixing member according to this embodiment. As shown in Figures 4 and 5, the fixing member 11 (11A, 11B) comprises a pipe clamping portion 111, a fastening portion 112, and a fixing portion 113.

[0024] The pipe clamping portion 111 has a semi-cylindrical shape, formed by cutting a cylindrical body in half, and clamps half of the outer circumference of the pipe 4. The pipe clamping portion 111 has a semi-cylindrical shape (half-split structure) formed by cutting a cylindrical body in half, so that the pipe clamping device 10 can be installed even if the pipe 4 is already installed in the duct section 7 of the underground space 3.

[0025] The clamping portion 112 is formed into a flat plate shape by integral molding with the pipe clamping portion 111. The clamping portion 112 is formed at both ends of the pipe clamping portion 111 in the first direction (indicated as the X-axis direction in Figure 4), and each has one or more bolt holes 112h.

[0026] The fixing portion 113 has a flat plate shape and is joined to one end of the pipe clamping portion 111 and the fastening portion 112 in a second direction (indicated as the Y-axis direction in Figure 4) perpendicular to the first direction (X-axis direction). The fixing portion 113 is also positioned in a third direction (indicated as the Z-axis direction in Figure 4) perpendicular to the first and second directions. The fixing portion 113 also has one or more anchor bolt holes 113h. The fixing portion 113 may be joined to the pipe clamping portion 111 and the fastening portion 112 by welding, but the joining method is not limited to welding. The fixing portion 113 may be integrally molded with the pipe clamping portion 111 and the fastening portion 112 by press working or the like. In Figures 4 and 5, the fixing portion 113 is represented as a semicircular flat plate shape, but the shape of the fixing portion 113 is not limited to a semicircle. The shape of the fixing portion 113 may be a polygon such as a rectangle.

[0027] It is desirable that the pair of fixing members 11A and 11B be made of the same material as the pipe 4. In order to suppress the expansion of the pipe 4 (flexible pipe 4) during gas pumping, it is beneficial to match the thermal expansion coefficients of the pipe 4 and the pair of fixing members 11A and 11B. Furthermore, manufacturing the pair of fixing members 11A and 11B and the pipe 4 from the same material is beneficial in suppressing the occurrence of contact corrosion due to dissimilar metals. For this reason, it is desirable that the material of the pair of fixing members 11A and 11B be the same material as the flexible pipe 4 (e.g., SUS).

[0028] The covering material 12 is installed between the pair of fixing members 11A and 11B and the pipe 4, covering the outer circumference of the pipe 4. The covering material 12 is preferably made of a cushioning material such as rubber in order to suppress the occurrence of rust due to galvanic corrosion between the materials of the pair of fixing members 11A and 11B and the material of the pipe 4, and to prevent damage to the pipe 4 when it is sandwiched between the pair of fixing members 11A and 11B.

[0029] The bolts and nuts 13 are attached to one or more bolt holes 112h opened in the tightening portions 112 formed at each end of the pair of fixing members 11A and 11B, and fasten the fixing members 11A and 11B together. By fastening each tightening portion 112 with one or more bolts and nuts 13 (bolt 13A and nut 13B), the pair of fixing members 11A and 11B clamp the pipe 4 whose outer circumference is covered with the covering material 12.

[0030] The anchor bolts 14 are installed in one or more anchor bolt holes 113h drilled in the fixing portions 113 of each of the pair of fixing members 11A and 11B. The pair of fixing members 11A and 11B that clamp the pipe 4 are fixed to the side wall 3A of the underground space by anchor bolts 14. Holes for installing the anchor bolts 14 are pre-installed in the side wall 3A of the underground space in order to resist the elongation of the pipe 4 by fixing the pipe clamping device 10 with one or more anchor bolts 14. The holes drilled in the side wall 3A of the underground space do not reach the back (soil) of the underground space 3, so groundwater does not flow in. The pipe clamping device 10 is installed so as not to interfere with the duct sleeve installed in the duct section 7. The duct sleeve is a component that forms the entrance surface of the underground space 3 (manhole, etc.).

[0031] As described above, when installing the piping 4 for pressurizing gas into the underground space 3, (i) the pipe clamping device 10 clamps the outer circumference of the pipe 4 with the pipe clamping portion 111 which has a split structure of a pair of fixing members 11A and 11B, and (ii) the pipe clamping device 10 is then fixed to the side wall 3A of the underground space with the planar fixing portion 113. In this way, the pipe clamping device 10 can perform a function to prevent protrusion (elongation). Figure 6 is a diagram showing the state of the piping before and after pressurizing gas. As shown in Figure 6, after pressurizing gas, by fixing the pipe clamping device 10 near the duct portion 7, it is possible to suppress buckling of the pipe 4 in the region a between the duct portion 7 and the underground space fixing portion where the fixing device 6 is installed.

[0032] <Piping clamping method> Figure 7 is a flowchart showing an example of a pipe clamping method that suppresses buckling of pipe 4 according to this embodiment.

[0033] In step S101, the worker installs the gas transport piping 4 inside the existing pipe 5.

[0034] In step S102, workers connect the pipes 4 together. Pipes 4 have a standard length limit. Therefore, multiple pipes 4 are connected as needed to ensure the distance from the supply tank 2A ​​to the consumption tank 2B, passing through multiple underground spaces 3.

[0035] In step S103, the worker covers the outer circumference of the pipe 4 that is held between the pair of fixing members 11 with the covering material 12.

[0036] In step S104, the worker clamps the pipe 4 with a pair of fixing members 11.

[0037] In step S105, the worker secures the pair of fixing members that hold the pipe 4 to the side wall 3A of the underground space with anchor bolts 14.

[0038] In step S106, the worker pumps gas into pipe 4.

[0039] In step S107, the worker compares the measured gas pressures of the supply tank 2A ​​and the demand tank 2B using the pressure gauge 20 to determine whether the gas pressure inside the piping 4 in the consumption tank 2B is above a threshold. If the gas pressure inside the piping 4 in the consumption tank 2B falls below the threshold, the process proceeds to step S108. If the pressure is above the threshold, the piping clamping operation is terminated.

[0040] In step S108, the worker determines that buckling has occurred in pipe 4 based on the fact that the gas pressure inside pipe 4 in the consumption tank 2B has fallen below a threshold.

[0041] In step S109, the worker investigates the cause of the buckling by examining the anchor bolt 14, the pipe clamping device 10, etc. Once the cause of the buckling is determined, the worker returns to step S101 and performs the pipe clamping operation again.

[0042] The pipe clamping device 10 described herein makes it possible to prevent buckling by suppressing the elongation of the pipe after gas is pumped. Furthermore, by preventing buckling, it is possible to prevent holes from forming in the pipe 4, thereby reducing the risk of explosion accidents caused by gas leaks such as hydrogen gas. In addition, the pipe clamping device 10 makes it possible to reduce the number of times repairs and other maintenance are required, thereby increasing economic efficiency.

[0043] The following additional information is disclosed regarding the embodiments described above.

[0044] (Additional note 1) A pipe clamping device for suppressing buckling of a gas-conducting pipe in an underground space, comprising: a pair of opposing fixing members, each fixed to the side wall of the underground space and clamping the pipe; and a covering material fitted between the pair of fixing members and the pipe and covering the outer circumference of the pipe. (Additional note 2) The pipe clamping device according to Appendix 1, wherein the pair of fixing members each comprises a semi-cylindrical pipe clamping portion, which is a half-cylindrical body cut in half and clamps half the circumference of the outer circumference of the pipe; flat plate-shaped fastening portions, each having one or more bolt holes, formed at both ends of the pipe clamping portion in a first direction by integral molding with the pipe clamping portion; and a flat plate-shaped fixing portion, each having one or more bolt holes, joined to one end of the pipe clamping portion and the fastening portion in a second direction perpendicular to the first direction. (Additional note 3) The pipe clamping device according to Appendix 1 or 2, wherein the pair of fixing members clamp the pipe whose outer circumference is covered with the covering material by tightening the respective clamping portions with one or more bolts and nuts. (Additional note 4) The pipe clamping device according to any one of the appendices 1 to 3, wherein the pair of fixing members are each fixed to the side wall of the underground space by anchor bolts. (Additional note 5) The pair of fixing members are made of the same material as the piping, and the pipe clamping device is as described in any one of the appendices 1 to 4. (Additional note 6) The material of the covering material is rubber, as described in any one of the appendix items 1 to 5. (Additional note 7) A pipe clamping method for suppressing buckling of a gas-carrying pipe in an underground space, comprising: covering the outer circumference of the pipe with a covering material; clamping the covered pipe from both sides with a pair of fixing members; fixing each of the pair of fixing members to the side wall of the underground space; determining whether the gas pressure inside the pipe in the consumption tank, measured by a pressure gauge, is above a threshold; and determining that buckling of the pipe has occurred if the gas pressure falls below the threshold.

[0045] Although the embodiments described above are representative examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of this disclosure. Therefore, the present invention should not be interpreted as being limited by the embodiments described above, and various modifications or changes are possible without departing from the scope of the claims. [Explanation of symbols]

[0046] 1. Gas supply pipeline 2A Supply side tank 2B Consumption tank 3 Underground space 3A Side wall of the underground space 4. Piping (flexible pipes) 5 Existing pipes 6 Fixtures 7. Duct section (duct opening) 10 Piping clamping device 11, 11A, 11B Fixing members 12 Covering material 13 Bolts and nuts 13A volt 13B Nut 14 Anchor bolts 20, 20A, 20B pressure gauges 111 Piping clamping part 112 Fastening part 112h Bolt holes 113 Fixed part 113h Anchor bolt hole

Claims

[Claim 1] A pipe clamping method for suppressing buckling of gas-conducting pipes in underground spaces, The steps include covering the outer circumference of the aforementioned pipe with a covering material, The steps include: clamping the covered pipe from both sides with a pair of fixing members; The steps include fixing each of the pair of fixing members to the side wall of the underground space, A step of determining whether the pressure of the gas inside the piping in the consumption tank, as measured by a pressure gauge, is above a threshold, The step of determining that buckling of the piping has occurred when the pressure of the gas falls below a threshold, A pipe clamping method that performs the following.

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