Piping structure

Abstract

A piping structure is provided that can absorb axial thrust and prevent damage caused by axial thrust. [Solution] The piping structure comprises an inner pipe projection extending radially outward from the inner pipe, a thrust bearing that receives axial thrust acting on the inner pipe via the inner pipe projection, and a strength bearing member that receives axial thrust acting on the thrust bearing.

Description

Technical Field

[0001] The present invention relates to a piping structure.

Background Art

[0002] A vacuum double pipe structure for flowing cryogenic fluids such as liquid hydrogen and liquid nitrogen is known. Such a vacuum double pipe structure may include bellows in order to absorb thermal contraction caused by the temperature of the fluid (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a contraction limiting portion that limits the range of contraction movement of a pipe in order to equalize the expansion and contraction amounts of a plurality of bellows arranged in a pipe having a long length. The contraction limiting portion has a configuration that restricts the movement of the pipe by bringing a protrusion of the moving pipe into contact with restraining fittings arranged on both sides of the protrusion. However, in such a configuration, if an excessive force acts on the restraining fittings, the restraining fittings may be damaged.

[0005] Patent Document 2 discloses an internal piping structure that includes a thrust receiving member for receiving the axial thrust acting on the internal piping due to the internal pressure when a cryogenic fluid flows through it. However, in such a configuration, the axial thrust acting on the internal piping is received by the thrust receiving member connected to the internal piping. In other words, the internal piping structure has a structure that receives the axial thrust acting on the internal piping with the internal piping itself. Therefore, there is a risk that excessive axial thrust may act on the thrust receiving member.

[0006] Patent Document 2 describes a structure in which the thermal contraction of the internal piping, composed of a bellows 11, an enlarged diameter section 7a, and a pipe 9, is absorbed by the bending of the bellows 11 and the pipe 9. If the thermally contracting portion (i.e., the thermally contractible portion) is long, the amount of thermal deformation absorbed by the bending of the pipe 9 becomes large. Therefore, it is necessary to consider making the length of the thermally contractible portion as short as possible, which limits the installation position of the internal piping. Furthermore, Patent Document 2 uses a special material such as Invar alloy, which has a low thermal deformation rate, as the thrust receiving member, but using such a special material increases costs.

[0007] Therefore, the present invention aims to provide a piping structure that can absorb axial thrust and prevent damage caused by axial thrust. [Means for solving the problem]

[0008] In one embodiment, a piping structure is provided. The piping structure comprises an inner pipe through which a cryogenic fluid flows, an outer member surrounding at least a portion of the inner pipe, an expansion joint attached to the inner pipe, an inner pipe projection connected to the inner pipe and extending radially outward from the inner pipe, a thrust bearing that receives axial thrust acting on the inner pipe via the inner pipe projection, and a strength bearing member connected to the outer member and receiving the axial thrust acting on the thrust bearing.

[0009] In one embodiment, the strength-bearing member extends in the same direction as the axial thrust. In one embodiment, the strength-bearing member comprises a tie rod bolt extending parallel to the outer member and a support member attached to the outer member and supporting the tie rod bolt. In one embodiment, the tie rod bolt is a molded member integrally with the outer member.

[0010] In one embodiment, the thrust bearing has a length determined based on the temperature difference between the temperature in the installation environment of the piping structure and the temperature of the cryogenic fluid. In one embodiment, the piping structure includes a heat insulating member positioned at the contact point between the thrust receiver and the inner pipe projection. In one embodiment, the piping structure includes a heat insulating member positioned on the contact surface of the inner pipe projection with the thrust receiver.

[0011] In one embodiment, when the internal pipe projection is defined as a first internal pipe projection, the piping structure comprises the first internal pipe projection and a second internal pipe projection located on the opposite side of the first internal pipe projection with respect to the expansion joint. In one embodiment, the strength-bearing member comprises a head plate top plate to which the thrust receiver is connected, and a rigid structural part connecting the head plate top plate and the inner tube. In one embodiment, the rigid structure is a head plate vacuum chamber in which a vacuum is formed.

[0012] In one embodiment, the inner tube projection comprises a plurality of partial flanges arranged at equal intervals along the circumferential direction of the inner tube. In one embodiment, the inner tube projection is provided with an annular flange attached to the outer circumferential surface of the inner tube. In one embodiment, the piping structure is connected to the outer member and includes a vacuum bellows that allows radial deformation of the outer member. [Effects of the Invention]

[0013] The strength-bearing member connected to the outer member bears the axial thrust acting on the inner pipe. Therefore, the piping structure can divert and absorb the axial thrust acting on the inner pipe to the strength-bearing member on the outer member side. As a result, the piping structure can be prevented from being damaged due to the axial thrust.

Brief Description of the Drawings

[0014] [Figure 1] It is a figure which shows one Embodiment of a piping structure. [Figure 2] It is a figure which shows an example of the piping to which the piping structure is connected. [Figure 3] It is a figure which shows an example of the piping to which the piping structure is connected. [Figure 4A] It is a figure which shows one Embodiment of a fluid transfer facility. [Figure 4B] It is a figure which shows the piping structure connected to a suction pipe. [Figure 5] It is an enlarged view of a part of the piping structure shown in FIG. 1. [Figure 6] FIG. 6(a) is a view showing one embodiment of the inner pipe projection. FIG. 6(b) is a view showing another embodiment of the inner pipe projection. [Figure 7] FIG. 7(a) is a view showing a heat insulating member disposed at the contact portion (tip) of the thrust receiver with the inner pipe projection. FIG. 7(b) is a view showing a heat insulating member disposed on the contact surface of the inner pipe projection with the thrust receiver. [Figure 8] It is a figure which shows another embodiment of a strength-bearing member. [Figure 9] It is a figure which shows another embodiment of a piping structure. [Figure 10] It is a figure which shows another embodiment of a piping structure. [Figure 11] It is a figure which shows a state where the thrust receiver receives the axial thrust acting on the inner pipe. [Figure 12] It is a figure which shows a piping structure provided with a heat insulating member. [Figure 13A]This figure shows the combination of the piping structure described with reference to Figure 1 and the suction pot described with reference to Figure 10. [Figure 13B] This figure shows the combination of the piping structure described with reference to Figure 1 and the suction pot described with reference to Figure 10. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described below with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions are omitted. In the multiple embodiments described below, the configuration of one embodiment that is not specifically described is the same as that of the other embodiments, so redundant descriptions are omitted.

[0016] Figure 1 shows one embodiment of a piping structure. As shown in Figure 1, the piping structure 1 comprises an inner pipe 10 through which cryogenic fluids such as liquid nitrogen or liquid hydrogen flow, an outer member (outer pipe in this embodiment) 30 surrounding at least a part of the inner pipe 10, and an expansion joint 20 attached to the inner pipe 10.

[0017] The inner pipe 10, outer pipe 30, and expansion joint 20 extend along the axis AX of the piping structure 1, and a vacuum is formed between the inner pipe 10 (and expansion joint 20) and the outer pipe 30. The inner pipe 10 and outer pipe 30 constitute a double pipe. Therefore, the piping structure 1 may be called a vacuum double pipe structure.

[0018] In the embodiment shown in Figure 1, the inner pipe 10 has a first inner pipe segment 10A and a second inner pipe segment 10B arranged on both sides of the expansion joint 20. The outer pipe 30 has a first outer pipe segment 30A corresponding to the first inner pipe segment 10A, a second outer pipe segment 30C corresponding to the second inner pipe segment 10B, and an outer pipe intermediate 30B arranged between the first outer pipe segment 30A and the second outer pipe segment 30C.

[0019] The first outer pipe section 30A is located radially outward of the first inner pipe section 10A. The second outer pipe section 30C is located radially outward of the second inner pipe section 10B. The outer pipe intermediate section 30B is located radially outward of the expansion joint 20.

[0020] The piping structure 1 includes a vacuum bellows 31 connected to the first outer pipe section 30A and a vacuum bellows 32 connected to the outer pipe intermediate section 30B. These vacuum bellows 31 and 32 have the same structure.

[0021] More specifically, each of the vacuum bellows 31 and 32 is flexible and allows for radial deformation of the outer tube 30 (more specifically, each of the first outer tube segment 30A and the outer tube intermediate 30B).

[0022] Furthermore, each of the vacuum bellows 31 and 32 is vacuum-resistant. Therefore, each of the vacuum bellows 31 and 32 can minimize the leakage of the vacuum formed between the inner tube 10 and the outer tube 30. Although not shown, the piping structure 1 may also include a vacuum bellows connected to the second outer tube segment 30C.

[0023] The expansion joint 20 includes a bellows 21 that expands and contracts due to thermal deformation of the inner tube 10 caused by the temperature of the fluid (more specifically, cryogenic fluid) passing through the inner tube 10, and a reinforcing ring 22 that reinforces the bellows 21.

[0024] In the embodiment shown in Figure 1, two combinations of bellows 21 and reinforcing rings 22 are arranged, but these combinations of bellows 21 and reinforcing rings 22 are not limited to the embodiment shown in Figure 1. For example, at least one combination of bellows 21 and reinforcing rings 22 may be arranged. Furthermore, although reinforcing rings 22 are provided in the embodiment shown in Figure 1, depending on the fluid pressure, reinforcing rings 22 are not necessarily required.

[0025] Figures 2 and 3 show an example of piping to which a piping structure is connected. Figure 4A shows an embodiment of a fluid transfer system. As shown in Figures 2 and 3, generally, piping structure 1 is connected to other piping (e.g., discharge pipe DP).

[0026] As shown in Figure 4A, the piping structure 1 and the discharge pipe DP are connected to a fluid transfer device. The fluid transfer device is connected to a suction pipe SP and is configured to transfer fluid that flows in through the suction pipe SP to the outside through the discharge pipe DP and the piping structure 1.

[0027] The fluid transfer equipment comprises a submerged motor pump SMP for pressurizing and transferring fluid, and a suction pot SPT that houses the submerged motor pump SMP. The submerged motor pump SMP comprises a multistage pump 110 for pressurizing the fluid in multiple stages, and a drive unit 111 for driving the multistage pump 110. The suction pot SPT comprises a casing 107 that houses the multistage pump 110 and the drive unit 111, and an end plate 108 that closes the open end of the casing 107.

[0028] Figure 4B shows a piping structure connected to the suction pipe. As shown in Figure 4B, the piping structure 1 may be connected not only to the discharge pipe DP but also to the suction pipe SP. In one embodiment, a piping structure 1 connected to both the suction pipe SP and the discharge pipe DP may be provided.

[0029] When cryogenic fluid passes through the inner pipe 10 of the piping structure 1, the inner pipe 10 (particularly the first inner pipe segment 10A) thermally contracts in a direction away from the expansion joint 20 due to the temperature of the fluid. Furthermore, due to the pressure of the fluid passing through the inner pipe 10, the expansion joint 20 expands in the axial direction AX, and an internal pressure thrust acts on the inner pipe 10 (particularly the first inner pipe segment 10A) connected to the expansion joint 20.

[0030] Thus, a force acting on the first inner tube section 10A is a force along the axial direction AX (i.e., a force generated by thermal contraction, an internal pressure thrust). Hereafter, this force along the axial direction AX may be referred to as the axial thrust.

[0031] When axial thrust acts on the first inner pipe section 10A, the piping structure 1 may deform and be damaged. Furthermore, when axial thrust acts on the first inner pipe section 10A, the discharge pipe DP, such as an elbow pipe, may be deformed. Such deformation may damage the piping structure 1 and the discharge pipe DP, and may cause fluid leakage. Therefore, the piping structure 1 has a configuration to prevent damage caused by axial thrust. The above configuration will be explained below.

[0032] Figure 5 is an enlarged view of a part of the piping structure shown in Figure 1. As shown in Figure 5, the piping structure 1 includes an inner pipe projection 40 connected to the inner pipe 10 (more specifically, the first inner pipe segment 10A) and extending radially outward from the inner pipe 10, a thrust receiver 50 that receives axial thrust acting on the inner pipe 10 via the inner pipe projection 40, and a strength bearing member 100 connected to the outer pipe 30 and receiving axial thrust acting on the thrust receiver 50.

[0033] The inner tube projection 40 is connected to the outer circumferential surface of the first inner tube segment 10A and extends toward the outer tube intermediate 30B, which is located radially outward from the first inner tube segment 10A. The inner tube projection 40 is positioned adjacent to the thrust receiver 50, and a gap is formed between the thrust receiver 50 and the inner tube projection 40.

[0034] Figure 6(a) shows one embodiment of the internal tube projection. Figure 6(b) shows another embodiment of the internal tube projection. As shown in Figure 6(a), the internal tube projection 40 comprises a plurality of partial flanges 40a arranged at equal intervals along the circumferential direction of the internal tube 10 (more specifically, the first internal tube segment 10A). In this embodiment, four partial flanges 40a are formed, but the number of partial flanges 40a is not limited to this embodiment.

[0035] As shown in Figure 6(b), the inner tube projection 40 may include an annular flange 40b attached to the outer circumferential surface of the inner tube 10 (more specifically, the first inner tube segment 10A). The annular flange 40b extends around the entire circumference of the first inner tube segment 10A.

[0036] The thrust support 50 constitutes a part of the first outer tube segment 30A (see Figure 1). In other words, the thrust support 50 and the first outer tube segment 30A are integrally molded members. The thrust support 50 has sufficient strength to withstand axial thrust. For example, the thrust support 50 may have a greater thickness than the first outer tube segment 30A, and may be made of a material with higher strength than the first outer tube segment 30A. The thickness and material of the thrust support 50 are determined based on the magnitude of the axial thrust.

[0037] When an axial thrust acts on the first inner tube segment 10A, the inner tube projection 40 moves in a direction toward the thrust receiver 50 and eventually comes into contact with the thrust receiver 50. The axial thrust is transmitted to the outer tube 30 (more specifically, the first outer tube segment 30A) via the thrust receiver 50. The axial thrust transmitted to the first outer tube segment 30A is borne by the strength-bearing member 100 located on the first outer tube segment 30A.

[0038] According to this embodiment, the piping structure 1 can absorb axial thrust acting on the inner pipe 10 by releasing the axial thrust to the strength-bearing member 100 on the outer pipe 30 side. With this configuration, even if a large axial thrust acts on the inner pipe 10, there is no risk of the inner pipe 10 being damaged. Therefore, the piping structure 1 can be prevented from being damaged due to axial thrust.

[0039] As shown in Figure 5, the strength-bearing member 100 extends in the same direction as the axial thrust acting on the inner tube 10 (and thrust receiver 50) (i.e., the axis AX direction). With this arrangement, the strength-bearing member 100 can adequately bear the axial thrust without being affected by bending stresses and other factors caused by large axial thrusts. Even if the axis of the outer tube 30 is misaligned with the axis of the inner tube 10, the vacuum bellows 31 and 32 can each prevent damage to the outer tube 30.

[0040] In the embodiment shown in Figure 5, the strength-bearing member 100 includes a tie rod bolt 102 extending parallel to the outer pipe 30, and support members 101A and 101B attached to the outer pipe 30 and supporting the tie rod bolt 102 (see Figures 1 and 5).

[0041] In this embodiment, multiple tie rod bolts 102 are arranged at equal intervals along the circumferential direction of the outer pipe intermediate body 30B. Each of the support members 101A and 101B has the same structure. Each of the support members 101A and 101B may have an annular shape, or may be a plurality of protruding members arranged at equal intervals along the circumferential direction of the outer pipe 30.

[0042] Support member 101A extends radially outward from the first outer tube segment 30A (more specifically, the thrust receiver 50). Support member 101B extends radially outward from the second outer tube segment 30C. The outer tube intermediate 30B is positioned between support members 101A and 101B and is connected to each of them. The tie rod bolt 102 is positioned to surround the outer tube intermediate 30B.

[0043] The support member 101A, which extends from the outer tube 30, is exposed to ambient temperature and has a relatively high temperature. On the other hand, the inner tube projection 40, which extends from the inner tube 10, has a relatively low temperature due to the influence of the fluid temperature. Therefore, when the inner tube projection 40 comes into contact with the thrust receiver 50 (more specifically, the tip portion 50a), the heat from the support member 101A may be transferred to the inner tube projection 40 through the outer tube 30 and the thrust receiver 50. The heat transferred to the inner tube projection 40 is then transferred to the inner tube 10, and as a result, the temperature of the fluid passing through the inner tube 10 may rise.

[0044] Therefore, the thrust receiver 50 has a predetermined length as a temperature gradient structure, extending from the support member 101A toward the tip 50a. The length of the thrust receiver 50 corresponds to the distance DT between the connection portion 50b with the support member 101A and the tip 50a of the thrust receiver 50. The length of the thrust receiver 50 is determined based on the temperature difference between the temperature in the installation environment of the piping structure 1 (ambient temperature) and the temperature of the fluid flowing through the piping structure 1 (fluid temperature).

[0045] For example, if the temperature difference between the ambient temperature and the fluid temperature is significantly large, it is preferable to increase the length of the thrust support 50 by a considerable amount in order to create a more sufficient temperature gradient. On the other hand, it is desirable that the thrust support 50 has sufficient strength to withstand the axial thrust acting on it. Therefore, if the axial thrust acting on the thrust support 50 is large, it is desirable to determine the thickness of the thrust support 50 to be a thickness that has sufficient strength against the axial thrust. In one embodiment, it is desirable to determine the material of the thrust support 50 to be a material that has sufficient strength against the axial thrust.

[0046] With this configuration, the heat input temperature to the support member 101A gradually decreases as it moves from the connection portion 50b of the thrust receiver 50 towards the tip portion 50a. Therefore, the temperature of the tip portion 50a of the thrust receiver 50 decreases to a temperature close to the fluid temperature, and the temperature of the inner tube projection 40 in contact with the tip portion 50a hardly rises. As a result, the temperature of the fluid passing through the inner tube 10 hardly rises.

[0047] Figure 7(a) shows a thermal insulation member positioned at the contact point (tip) of the thrust receiver with the internal tube projection. Figure 7(b) shows a thermal insulation member positioned on the contact surface of the internal tube projection with the thrust receiver. As shown in Figure 7(a), the piping structure 1 is equipped with a thermal insulation member HM positioned at the tip 50a of the thrust receiver 50. The thermal insulation member HM more effectively prevents heat input caused by the contact between the internal tube projection 40 and the tip 50a of the thrust receiver 50. A resin material can be given as an example of the thermal insulation member HM.

[0048] As shown in Figure 7(b), the piping structure 1 may be provided with a heat insulating member HM positioned on the contact surface 40c of the inner pipe projection 40 with the thrust receiver 50. The heat insulating member HM more effectively prevents heat input caused by contact between the inner pipe projection 40 and the tip portion 50a of the thrust receiver 50.

[0049] For example, if the internal tube projection 40 is provided with a plurality of partial flanges 40a (see Figure 6(a)), the heat insulating member HM may be placed on each of the partial flanges 40a. For example, if the internal tube projection 40 is provided with an annular flange 40b (see Figure 6(b)), the heat insulating member HM may have an annular shape.

[0050] In one embodiment, the heat insulating member HM may be placed on both the tip 50a of the thrust receiver 50 and the contact surface 40c of the inner tube projection 40. With such placement, the heat insulating member HM can more effectively prevent heat input.

[0051] Figure 8 shows another embodiment of the strength-bearing member. In the embodiment described above, the outer pipe intermediate 30B and the tie rod bolt 102 are made of different materials (see, for example, Figure 5), but as shown in Figure 8, the tie rod bolt 102 may be integrally molded with the outer pipe intermediate 30B.

[0052] In other words, the outer tube intermediate 30B has the function of a tie rod bolt 102. In this case, for example, the outer tube intermediate 30B may have a thickness equivalent to that of the tie rod bolt 102, or it may be made of a material having equivalent strength to that of the tie rod bolt 102.

[0053] In the embodiment shown in Figure 8, the strength-bearing member 100 includes a tie rod bolt-integrated outer tube 60 that has the functions of a tie rod bolt 102 and an outer tube 30. The tie rod bolt-integrated outer tube 60 has a configuration that integrates the function of the tie rod bolt 102, which bears axial thrust, and the function of the outer tube 30. In this embodiment, not only can the number of parts of the piping structure 1 be reduced, but the size of the piping structure 1 can also be reduced.

[0054] In the embodiment shown in Figure 8, the support member 101A (and support member 101B) is made of a different material from the tie rod bolt integrated outer tube 60, but the tie rod bolt integrated outer tube 60 and the support member 101A (and support member 101B) may be integrally molded members.

[0055] Figure 9 shows another embodiment of the piping structure. As shown in Figure 9, the piping structure 1 may include not only an internal pipe projection 40 connected to the first internal pipe segment 10A (i.e., the first internal pipe projection 40A), but also an internal pipe projection 40 connected to the second internal pipe segment 10B (i.e., the second internal pipe projection 40B).

[0056] In this case, the second internal tube projection 40B is located on the opposite side of the first internal tube projection 40A with respect to the expansion joint 20. In other words, the first internal tube projection 40A and the second internal tube projection 40B are located on both sides of the expansion joint 20. Each of the internal tube projections 40A and 40B may be provided with a partial flange 40a or an annular flange 40b (see Figures 6(a) and 6(b)).

[0057] In the embodiment shown in Figure 9, the first inner tube projection 40A is positioned adjacent to the first thrust receiver 50A formed on the first inner tube segment 10A. The second inner tube projection 40B is positioned adjacent to the second thrust receiver 50B formed on the second inner tube segment 10B. With this arrangement, the first thrust receiver 50A receives the axial thrust acting on the first inner tube segment 10A via the first inner tube projection 40A, and the second thrust receiver 50B receives the axial thrust acting on the second inner tube segment 10B via the second inner tube projection 40B.

[0058] The configuration according to this embodiment is particularly effective when discharge pipes DP are connected to both sides of the piping structure 1 (see, for example, Figure 3). In this case, the second inner pipe section 10B may deform due to axial thrust, similar to the first inner pipe section 10A, but the second thrust receiver 50B can receive the axial thrust acting on the second inner pipe section 10B and prevent deformation of the second inner pipe section 10B.

[0059] Figure 10 shows another embodiment of the piping structure. In the embodiment shown in Figure 10, the piping structure 1 is integrally configured with a suction pot SPT having a vacuum insulation structure. In the embodiments shown in Figures 4A and 4B, the suction pot SPT has a single-wall structure. On the other hand, in the embodiment shown in Figure 10, the suction pot SPT has a double-wall structure.

[0060] The piping structure 1 is located on the discharge side of the fluid pressurized by the multistage pump 110 and functions as a discharge port. Therefore, in this embodiment, the piping structure 1 is located upstream of the discharge pipe DP in the direction of fluid flow.

[0061] As shown in Figure 10, the piping structure 1 comprises an inner pipe 210 through which cryogenic fluid flows, an outer member 230 surrounding at least a portion of the inner pipe 210, an expansion joint 220 attached to the inner pipe 210, an inner pipe projection 240 connected to the inner pipe 210 and extending radially outward from the inner pipe 210, a thrust receiver 250 that receives axial thrust acting on the inner pipe 210 via the inner pipe projection 240, and a strength-bearing member (i.e., a head plate) 200.

[0062] The expansion joint 220 has essentially the same configuration as the expansion joint 20. Therefore, a detailed explanation of the expansion joint 220 will be omitted. The strength-bearing member 200 comprises a head plate top 301 to which the thrust receiver 250 is connected, and a rigid structure 300 that connects the head plate top 301 and the inner tube 210.

[0063] The inner tube 210 extends through the head plate top plate 301 and extends along the axis AX direction. In this embodiment as well, the strength bearing member 200 as a whole extends in the same direction as the axial thrust acting on the thrust receiver 250 (i.e., the axis AX direction).

[0064] The head plate top plate 301 is a flange extending perpendicular to the axis AX, and the outer member 230 is connected to the head plate top plate 301 of the strength-bearing member 200. The outer member 230 constitutes the casing of the suction pot SPT and has a double-wall structure. More specifically, the outer member 230 has an inner wall (inner chamber) 230a surrounding the rigid structure part 300, and an outer wall (outer chamber) 230b surrounding the inner wall 230a. A vacuum is formed between the inner wall 230a and the outer wall 230b.

[0065] The rigid structure 300 is a head plate vacuum chamber in which a vacuum is formed in its internal space IS. The internal space IS is an annular space enclosed by the rigid structure 300 and the inner tube 210 (and expansion joint 220). Hereinafter, in this specification, the rigid structure 300 may be referred to as the head plate vacuum chamber 300.

[0066] In the embodiment shown in Figure 10, the head plate vacuum chamber 300 has a bottomed shape with a U-shaped cross-section. The head plate vacuum chamber 300 is an integrally molded member with the head plate top plate 301 and has a body portion 303 extending in the axial direction AX and an end wall 302 located at the end of the body portion 303. The end wall 302 extends perpendicular to the axial direction AX.

[0067] The end wall 302 has a through-hole 302a formed in its center, which is connected to the end of the inner pipe 210. Thus, the fluid pressurized by the multi-stage pump 110 passes through the through-hole 302a and is then transferred to the outside through the inner pipe 210 and the discharge pipe DP.

[0068] Figure 11 shows how the thrust receiver receives the axial thrust acting on the inner tube. As shown in Figure 11, when cryogenic fluid is introduced into the inner tube 210, an axial thrust acts on the inner tube 210, and the inner tube projection 240 moves in a direction toward the thrust receiver 250 (see the white arrow in Figure 11).

[0069] Although not shown in the figures, the internal tube projection 240 has the same structure as the internal tube projection 40 described with reference to the above-described embodiment. Therefore, the internal tube projection 240 has multiple partial flanges (see Figure 6(a)) or annular flanges (see Figure 6(b)).

[0070] The axial thrust is transmitted to the head plate top plate 301 via the thrust receiver 250. The axial thrust transmitted to the head plate top plate 301 is borne by the head plate vacuum chamber 300 (more specifically, the body 303 and end walls 302). In the embodiment shown in Figure 11, the end walls 302 connected to the inner tube 210 deform upward together with the inner tube 210, and the body 303 deforms in a direction approaching the inner tube 210, i.e., tapered.

[0071] In this embodiment as well, the piping structure 1 can absorb the axial thrust acting on the inner pipe 210 by dissipating it to the strength-bearing member 200. With this configuration, even if a large axial thrust acts on the inner pipe 210, there is no risk of the inner pipe 210 being damaged. Therefore, the piping structure 1 can be prevented from being damaged due to axial thrust.

[0072] Figure 12 shows a piping structure equipped with an insulating member. In the embodiment shown in Figure 12, as in the embodiments shown in Figures 7(a) and 7(b), the piping structure 1 may also be equipped with an insulating member HM. The insulating member HM may be placed on the tip portion 250a of the thrust receiver 250, or on the contact surface 240a of the inner pipe projection 240 with the thrust receiver 250. The insulating member HM more effectively prevents heat input caused by the contact of the inner pipe projection 240 with the tip portion 250a of the thrust receiver 250.

[0073] Although not shown in the diagram, the piping structure 1 described with reference to Figures 10 to 12 is also applicable to the suction pot SPT described with reference to Figure 4.

[0074] Figures 13A and 13B show combinations of the piping structure described with reference to Figure 1 and the suction pot described with reference to Figure 10. In the embodiment shown in Figure 13A, the piping structure 1 is connected to the discharge pipe DP. In the embodiment shown in Figure 13B, the piping structure 1 is connected to the suction pipe SP.

[0075] In the embodiments shown in Figures 13A and 13B, a combination of a head plate top 301 that closes the upper opening of the suction pot SPT and a head plate vacuum chamber 300 is arranged. These combinations constitute a vacuum-insulated lid. The vacuum-insulated lid creates a vacuum above the suction pot SPT. The inner wall 230a and outer wall 230b create a vacuum at the sides and bottom of the suction pot SPT. Therefore, the fluid transfer equipment can significantly reduce the amount of heat input from the top, sides, and bottom of the suction pot SPT.

[0076] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims. [Explanation of Symbols]

[0077] 1. Piping structure 10 Inner tube 10A First Inner Pipe Split Body 10B 2nd inner tube division body 20 Expansion joints 21 Bellows 22 Reinforcement rings 30 Outer pipe (outer member) 30A 1st outer tube division body 30B Outer tube intermediate 30C 2nd outer tube division body 31 Vacuum bellows 32 Vacuum bellows 40 Inner canal protrusion 40A 1st inner tube protrusion 40B 2nd inner tube protrusion 40a Partial flange 40b Annular flange 40c contact surface 50 thrust receiver 50A No. 1 thrust receiver 50B Second thrust receiver 50a Tip 50b Contact area 60 Tie rod bolt integrated outer tube 100 Strength-bearing member 101A, 101B Support members 102 Tie rod bolt 107 Casing 108 End Plate 110 Multistage pump 111 Drive unit 200 Strength-bearing member (head plate) 210 Inner tube 220 Expansion joint 230 Outer member 230a Inner wall (inner tank) 230b Outer wall (outer tank) 240 Inner canal protrusion 240a contact surface 250 thrust receiver 250a Tip 300 Rigid structure section (head plate vacuum chamber) 301 Head Plate Top 302 End wall 302a through hole 303 Torso AX axis DP discharge pipe SP suction pipe SMP Submerged Motor Pump SPT Suction Pot DT distance HM Insulating Material IS interior space

Claims

1. A piping structure, An inner tube through which cryogenic fluid flows, An outer member that surrounds at least a portion of the inner tube, An expansion joint attached to the inner pipe, An inner tube projection connected to the inner tube and extending radially outward from the inner tube, A thrust receiver that receives the axial thrust acting on the inner tube via the inner tube projection, A piping structure comprising: a strength-bearing member connected to the outer member and receiving the axial thrust acting on the thrust receiver.

2. The piping structure according to claim 1, wherein the strength-bearing member extends in the same direction as the axial thrust.

3. The aforementioned strength-bearing member is A tie rod bolt extending parallel to the outer member, The piping structure according to claim 1, further comprising a support member attached to the outer member and supporting the tie rod bolt.

4. The piping structure according to claim 3, wherein the tie rod bolt is an integrally molded member with the outer member.

5. The piping structure according to claim 1, wherein the thrust support has a length determined based on the temperature difference between the temperature in the installation environment of the piping structure and the temperature of the cryogenic fluid.

6. The piping structure according to claim 1, wherein the piping structure comprises a heat insulating member disposed at the contact portion of the thrust receiver with the inner pipe projection.

7. The piping structure according to claim 1, wherein the piping structure comprises a heat insulating member disposed on the contact surface of the inner pipe projection with the thrust receiver.

8. If the aforementioned internal pipe projection is defined as the first internal pipe projection, then the piping structure is, The first inner tube projection and, The piping structure according to claim 1, wherein the expansion joint comprises a second internal pipe projection located on the opposite side of the first internal pipe projection.

9. The aforementioned strength-bearing member is The head plate top plate to which the thrust receiver is connected, The piping structure according to claim 1, comprising a rigid structural part connecting the head plate top plate and the inner pipe.

10. The piping structure according to claim 9, wherein the rigid structure is a head plate vacuum chamber in which a vacuum is formed inside.

11. The piping structure according to claim 1, wherein the internal pipe projection comprises a plurality of partial flanges arranged at equal intervals along the circumferential direction of the internal pipe.

12. The piping structure according to claim 1, wherein the inner pipe projection is provided with an annular flange attached to the outer surface of the inner pipe.

13. The piping structure according to claim 1, wherein the piping structure is connected to the outer member and includes a vacuum bellows that allows radial deformation of the outer member.

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