Expansion joint

Abstract

To provide an expansion joint capable of easily replacing a sensor provided in an inner side thereof.SOLUTION: An expansion joint 20 includes: a bellows material 23 provided between a first flange 21 and a second flange 22, having elasticity, and preventing fluid from flowing out; a protective pipe 37 provided along a circumferential direction in an inner side relative to the bellows material 23; FBG sensors 40, 41, 42 provided in the inner side of the protective pipe 37; and an introduction portion 50 provided in at least one of the bellows material 23, the first flange 21, and the second flange 22, and introducing the protective pipe 37 and the FBG sensors 40, 41, 42 to the inner side of the bellows material 23. The introduction portion 50 secures airtightness between the inside and the outside of at least one of the bellows material 23, the first flange, and the second flange in which the introduction portion 50 is provided.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention relates to an expansion joint.

Background Art

[0002] An expansion joint is used at the connection part of a duct that transfers fluids such as high-temperature gas, which is provided in facilities such as thermal power plants and chemical plants, for the purpose of absorbing displacements, vibrations, stresses, etc. generated in the duct itself. As an example of a conventional expansion joint, for example, the expansion joint described in Patent Document 1 is known. This expansion joint is formed by connecting a pair of flanges that can be connected to a duct with a cylindrical non-metallic bellows material having expansion and contraction flexibility and a heat insulation part, and a plurality of temperature fuses are arranged in the heat insulation part. By detecting the open state of these temperature fuses, a decrease in the heat insulation function of the heat insulation part is detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the expansion joint described in Patent Document 1, when the temperature fuse provided inside the expansion joint is disconnected due to high heat, or when it is disconnected due to aging deterioration during use without damage to the expansion joint body, in order to replace the temperature fuse, it is necessary to disassemble the expansion joint, reinstall the temperature fuse, and reassemble the expansion joint. Therefore, although the expansion joint itself does not need to be disassembled and repaired, it is necessary to disassemble and repair the expansion joint body for replacing the temperature fuse, resulting in a large number of man-hours and huge costs.

[0005] The present invention has been made to solve such problems, and an object thereof is to provide an expansion joint that can easily replace sensors and the like provided inside.

Means for Solving the Problems

[0006] In order to solve the above problems, an expansion joint according to the present invention is an expansion joint that connects between a first duct and a second duct through which a fluid flows and through which the fluid flows inside, and includes a first flange connected to the first duct, a second flange connected to the second duct, an outflow prevention portion provided between the first flange and the second flange and having elasticity to prevent the outflow of the fluid, a tubular protection member provided along the circumferential direction inside the outflow prevention portion, a linear sensor provided inside the tubular protection member, and an introduction portion provided on at least one of the outflow prevention portion, the first flange, or the second flange to introduce the tubular protection member and the linear sensor into the inside of the outflow prevention portion. The introduction portion is configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention portion, the first flange, or the second flange where the introduction portion is provided.

[0007] Further, it includes a lead-out portion provided on at least one of the outflow prevention portion, the first flange, or the second flange, through which the tubular protection member and the linear sensor introduced into the inside of the outflow prevention portion from the introduction portion are led out. The lead-out portion may be configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention portion, the first flange, or the second flange where the lead-out portion is provided. Further, the tubular protection member may be formed of metal. Further, the tubular protection member may be formed of resin. Further, the tubular protection member may have a radially inner portion that contacts the linear sensor formed of resin and a radially outer portion formed of metal.

Effects of the Invention

[0008] The expansion joint according to the present invention includes a linear sensor provided inside a tubular protective member, and an introduction portion provided in at least one of the outflow prevention portion, the first flange, or the second flange, for introducing the tubular protective member and the linear sensor into the inside of the outflow prevention portion. The introduction portion is configured to ensure airtightness between the inner side and the outer side of at least one of the outflow prevention portion, the first flange, or the second flange where the introduction portion is provided. Therefore, an expansion joint that can easily replace the sensor provided inside can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0010] Embodiment 1. Hereinafter, the expansion joint according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic view of a non-metallic expansion joint in Embodiment 1. In Embodiment 1, a duct structure 1 disposed in a thermal power generation facility or the like has a cylindrical upstream duct 11 and a downstream duct 12 through which a high-temperature fluid such as exhaust gas flows inside. The expansion joint 20, which is a non-metallic expansion joint provided in the duct structure 1, is disposed between the upstream duct 11 and the downstream duct 12 to connect the two ducts and prevent the outflow of the internal fluid. Further, the expansion joint 20 absorbs fluctuations in the distance between the two ducts due to the expansion and contraction of the upstream duct 11 and the downstream duct 12, and also absorbs vibrations and the like generated in the upstream duct 11 and the downstream duct 12 due to the flow of the fluid. Note that the expansion joint 20 shown in FIG. 1 is an example of a cylindrical shape, but the actual shape is not limited to this, and it is common to adopt a structure that matches the shape of the duct structure to be connected. For example, a rectangular tube shape can also be used.

[0011] The expansion joint 20 has a first flange 21 connected to the upstream duct 11, a second flange 22 connected to the downstream duct 12, and a bellows material 23 provided between the first flange 21 and the second flange 22 for hermetically connecting these flanges. The pair of first and second flanges 21, 22 and the bellows material 23 are configured in a cylindrical shape to match the shapes of the cylindrical upstream duct 11 and downstream duct 12. A first duct flange 14 is formed on the upstream duct 11, and the first flange 21 is formed to correspond to the first duct flange 14. By connecting (for example, fastening with bolts or the like) the first flange 21 and the first duct flange 14, the expansion joint 20 and the upstream duct 11 are hermetically connected. A second duct flange 15 is formed on the downstream duct 12, and the second flange 22 is formed to correspond to the second duct flange 15. By connecting (for example, fastening with bolts or the like) the second flange 22 and the second duct flange 15, the expansion joint 20 and the downstream duct 12 are hermetically connected. Also, the first flange 21 and the second flange 22 can be formed of any metal such as stainless steel. The bellows material 23 has dimensions necessary for the distance between both ends (connection surfaces with the upstream duct 11 and the downstream duct 12) of the expansion joint 20 to be sufficiently longer than the separation distance between the connected upstream duct 11 and downstream duct 12. And by attaching the expansion joint 20 between the upstream duct 11 and the downstream duct 12 with the bellows material 23 in a relaxed state, thermal expansion, vibration, etc. of both ducts are absorbed.

[0012] FIG. 2 is a schematic cross-sectional view of the upstream duct 11, the downstream duct 12, and the expansion joint 20 shown in FIG. 1. A baffle plate 13 is provided downstream of the upstream duct 11 and is formed as a cylindrical body with a tip smaller than the inner diameter of the downstream duct 12. This baffle plate 13 can be formed of a metal such as stainless steel, for example. Due to the presence of the baffle plate 13, the expansion joint 20 is arranged so as not to be directly exposed to the fluid flowing in the direction of arrow A through the upstream duct 11.

[0013] The expansion joint 20 has a bellows material 23 disposed between a first flange 21 and a second flange 22 on the outermost side in the radial direction, for preventing the outflow of the fluid flowing through the upstream duct 11 and the downstream duct 12. The bellows material 23 is composed of four layers of laminated members, namely a first bellows member 24, a second bellows member 25, a third bellows member 26, and a fourth bellows member 27, laminated in order from the outside in the radial direction. Further, the bellows material 23 is configured to have expansion and contraction flexibility along the fluid flow direction indicated by the arrow A and the direction intersecting the fluid flow direction. Note that the bellows material 23 constitutes an expansion and contraction portion.

[0014] The first bellows member 24, the second bellows member 25, the third bellows member 26, and the fourth bellows member 27 constituting the bellows material 23 can include any layers such as a seal layer for preventing the outflow of the fluid, a reinforcing layer for reinforcing the strength of the bellows material 23, and a protective layer for protecting the bellows material 23 from the surrounding environment such as outside air, moisture, and ultraviolet rays. The bellows material 23 can be formed by combining such arbitrary layers in any suitable order. Further, the bellows material 23 is not limited to a configuration of four layers of members. For example, it can be configured with 1 to 3 layers of members, or it can be configured with 5 or more layers of members. Also, the first bellows member 24, the second bellows member 25, the third bellows member 26, and the fourth bellows member 27 can be formed by appropriately adopting any known materials such as PTFE (polytetrafluoroethylene), inorganic fiber cloth such as glass cloth, organic fiber cloth such as nylon, metal fiber cloth, and film-like resin.

[0015] Further, the expansion joint 20 has a heat insulating portion 30 on the radially inner side of the bellows material 23. The heat insulating portion 30 insulates the heat of the fluid flowing through the expansion joint 20 and prevents the heat of the fluid from being directly transmitted to the bellows material 23 provided on the radially outer side. The heat insulating portion 30 is composed of five layers of heat insulating members, namely, a first heat insulating member 31, a second heat insulating member 32, a third heat insulating member 33, a fourth heat insulating member 34, and a fifth heat insulating member 35, laminated in order from the radially outer side. The first heat insulating member 31, the second heat insulating member 32, the third heat insulating member 33, the fourth heat insulating member 34, and the fifth heat insulating member 35 constituting the heat insulating portion 30 can include any layer as a heat insulating layer to satisfy conditions such as heat insulating performance, and the heat insulating portion 30 can be formed by combining such arbitrary layers in any suitable order. Further, the heat insulating portion 30 is not limited to a configuration in which five layers of members are laminated. For example, it can be configured with 1 to 4 layers of members, or it can be configured with 6 or more layers of members. The materials of the first heat insulating member 31, the second heat insulating member 32, the third heat insulating member 33, the fourth heat insulating member 34, and the fifth heat insulating member 35 constituting the heat insulating portion 30 can be appropriately formed by adopting any known material. The first heat insulating member 31, the second heat insulating member 32, the third heat insulating member 33, the fourth heat insulating member 34, and the fifth heat insulating member 35 can be formed by wrapping inorganic fiber felts such as glass felt, ceramic felt, and alumina felt with inorganic fiber cloths such as glass cloth, ceramic cloth, and alumina cloth, and then wrapping this with a net (such as a mesh) knitted with an appropriate metal wire such as a stainless steel wire, an Inconel (registered trademark) wire, or a copper wire. Alternatively, it can be formed by wrapping with an organic fiber or an organic film such as PTFE.

[0016] On the outer side in the radial direction of the first heat insulating member 31 of the expansion joint 20, a protective tube 37 made of stainless steel is wound, and an FBG sensor 41 is inserted inside the protective tube 37. Further, on the outer side in the radial direction of the second heat insulating member 32, on the side closer to the downstream duct 12 with respect to the FBG sensor 41, the protective tube 37 is wound, and an FBG sensor 40 is inserted inside the protective tube 37. Furthermore, on the outer side in the radial direction of the second heat insulating member 32, on the side closer to the upstream duct 11 with respect to the FBG sensor 41, the protective tube 37 is wound, and an FBG sensor 42 is inserted inside the protective tube 37. That is, the protective tube 37 is wound on the outer side in the radial direction of the heat insulating portion 30. Also, the FBG sensors 40, 41, 42 are disposed on the outer side in the radial direction of the heat insulating portion 30 and on the inner side in the radial direction of the bellows material 23. The FBG sensors 40, 41, 42 are temperature sensors configured by forming a plurality of diffraction gratings by laser processing in the core portion of the optical fiber.

[0017] As will be described in detail later, the protective tube 37 and the FBG sensors 40, 41, 42 are introduced from the outside to the inside of the expansion joint 20 via the introduction portion formed in the bellows material 23. Note that the FBG sensors 40, 41, 42 constitute an optical fiber temperature sensor, and the protective tube 37 constitutes a tubular protective member.

[0018] FIG. 3 is a cross-sectional view obtained by cutting the protective tube 37 and the FBG sensors 40, 41, 42 according to the first embodiment along the radial direction. The FBG sensors 40, 41, 42 are accommodated by the protective tube 37 made of stainless steel and are wound on the outer side in the radial direction of the heat insulating portion 30 shown in FIG. 2.

[0019] FIG. 4 is a schematic diagram of the expansion joint 20 according to the first embodiment, the protective tube 37, and the FBG sensors 40, 41, and 42. For convenience of explanation, in FIG. 4, the description of some configurations of the expansion joint 20, such as the flanges 21 and 22, is omitted. The FBG sensors 40, 41, and 42 are provided in order from the downstream side with respect to the fluid flow direction indicated by the arrow A. The FBG sensors 40, 41, and 42 are wound around the outer side in the radial direction of the heat insulating portion 30 of the expansion joint 20 at intervals along the circumferential direction in a state of being housed in the protective tube 37 and parallel to each other. That is, the FBG sensors 40, 41, and 42 are wound around the inner side in the radial direction of the bellows material 23 (see FIG. 2) at intervals along the circumferential direction and parallel to each other.

[0020] The FBG sensors 40, 41, and 42 are optical fibers having a cladding portion whose surface is coated with a polyimide resin and a core portion disposed inside the cladding portion, and a plurality of diffraction gratings (not shown) formed in the core portion by laser processing are provided at predetermined intervals in the extending direction of the optical fiber. It is an optical fiber temperature sensor. In addition, diffraction gratings are also provided in the portions of the FBG sensors 40, 41, and 42 that are hidden by the expansion joint 20 and described by broken lines in FIG. 4. That is, each of the FBG sensors 40, 41, and 42 has a plurality of diffraction gratings on one optical fiber. The diffraction grating constitutes a temperature measurement unit.

[0021] One end of the protective tube 37 is inserted into the introduction portion 50 formed in the bellows material 23 on the side closer to the first flange 21 (see FIG. 2), and the FBG sensors 40, 41, and 42 are introduced from the outside to the inside of the expansion joint 20 via the introduction portion 50. The introduction portion 50 is configured to be able to maintain the airtightness and strength between the outside and the inside of the bellows material 23 when the protective tube 37 is inserted.

[0022] As the configuration of the introduction part 50 provided in the bellows material 23, for example, a protective tube 37 may be inserted between the laminated bellows materials 23, or a part of the bellows material 23 may be perforated to insert the protective tube 37, and then the perforated part may be sealed with a sealing member. Further, the introduction part 50 may be provided on the first flange 21 or the second flange 22. As the configuration of the introduction part 50 provided on the first flange 21 or the second flange 22, for example, a part of the first flange 21 or the second flange 22 may be perforated to insert the protective tube 37, and then the perforated part may be sealed with a sealing member, or a notch part into which the protective tube 37 can be inserted may be formed in advance by press forming or the like on a part of the first flange 21 or the second flange 22, and the protective tube may be inserted into this notch part.

[0023] One end of the protective tube 37 protrudes outside the introduction part 50, and the FBG sensors 40, 41, 42 are not housed in the protective tube 37 but are exposed on the distal side from the introduction part 50. The FBG sensors 40, 41, 42 are connected to an interrogator 44 provided outside the expansion joint 20. The interrogator 44 has a light source device for making light incident on the FBG sensors 40, 41, 42 and a light wavelength measuring device for measuring and analyzing the wavelength of the reflected light from each diffraction grating, and is housed and disposed in an appropriate weatherproof case.

[0024] Next, the operation of the expansion joint 20 according to the first embodiment will be described. The thermal power generation facility and the like according to the first embodiment have a duct structure 1 provided with the expansion joint 20 shown in FIG. 1. During the operation of the thermal power generation facility and the like, the interrogator 44 shown in FIG. 4 makes light incident on the FBG sensors 40, 41, 42 and measures and analyzes the wavelength of the reflected light from each diffraction grating.

[0025] During the operation of a thermal power generation facility or the like having the duct structure 1, when damage occurs to a part of the heat insulation portion 30 of the expansion joint 20 shown in FIG. 2 due to aging deterioration, abnormal operation, interference of foreign substances in the fluid, etc., the heat insulation performance of blocking (heat insulation) the heat of the fluid flowing inside is partially reduced. For this reason, the temperature of the heat insulation portion 30, the bellows material 23, and the surroundings on the radially outer side of the location where the reduction in the heat insulation performance of the heat insulation portion 30 has occurred rises compared to before the occurrence of the reduction in the heat insulation performance. As a result, the temperature of the diffraction grating (see FIG. 4) disposed near the location where the reduction in the heat insulation performance of the heat insulation portion 30 has occurred rises. Due to this rise in the temperature of the diffraction grating, the wavelength of the reflected light from the diffraction grating changes (shifts) corresponding to the rise in temperature. The interrogator 44 measures the wavelength of this reflected light, compares the change in wavelength with the wavelength before the change, and analyzes it, thereby detecting in which diffraction grating among the diffraction gratings provided in the FBG sensors 40, 41, 42 the temperature change has occurred. And it is possible to specify that the heat insulation portion 30 has deteriorated near the diffraction grating where the temperature change has occurred. That is, it is possible to specify the location where the heat insulation portion 30 of the expansion joint 20 has deteriorated.

[0026] Also, damage may occur to a part of the bellows material 23 of the expansion joint 20 shown in FIG. 2 due to heat, external force, etc., and the airtightness of the bellows material 23 may be impaired. In this case, due to the internal fluid and outside air flowing inside and outside the bellows material 23 at the location where the damage to the bellows material 23 has occurred, the temperature of the heat insulation portion 30 and its surroundings located on the radially inner side of the location where the damage has occurred may rise or fall compared to before the occurrence of the damage. As a result, the temperature of the diffraction grating (see FIG. 4) disposed near the location where the damage has occurred rises or falls. Due to this rise or fall in the temperature of the diffraction grating, the wavelength of the reflected light from the diffraction grating changes. The interrogator 44 compares the change in the wavelength of this reflected light with the wavelength before the change and analyzes it, thereby detecting in which diffraction grating of the FBG sensors 40, 41, 42 the temperature change has occurred. And it is possible to specify that the bellows material 23 has been damaged near the diffraction grating where the temperature change has occurred. That is, it is possible to specify the location where the bellows material 23 of the expansion joint 20 has been damaged.

[0027] Next, the case where the FBG sensors 40, 41, and 42 shown in FIG. 4 fail will be described. In the first embodiment, at the time of assembling the expansion joint 20, a protective tube 37 made of stainless steel is wound in advance around the heat insulating portion 30 inside the bellows material 23. For example, when the FBG sensor 40 fails due to aging deterioration or the influence of abnormal temperature, an operator pulls out the FBG sensor 40 from the outside of the introduction portion 50. Since the protective tube 37 is made of stainless steel, it has sufficient rigidity to insert the FBG sensor 40, and the friction between the FBG sensor 40 and the inside of the protective tube 37 is small. Therefore, by the operator pulling out the FBG sensor 40 from the outside of the introduction portion 50, the FBG sensor 40 can be easily removed from the inside of the expansion joint 20.

[0028] Next, after removing the failed FBG sensor 40, an operator inserts a normal FBG sensor 40 into the protective tube 37 from the outside of the introduction portion 50. Since the protective tube 37 is made of stainless steel, it has sufficient rigidity, and the friction between the FBG sensor 40 and the inside of the protective tube 37 is small, and the operator can easily introduce the FBG sensor 40 from the outside to the inside of the introduction portion 50.

[0029] As described above, since the removal and introduction of the FBG sensor 40 can be easily performed by the protective tube 37 disposed inside the bellows material 23, it is not necessary to remove the bellows material 23 of the expansion joint 20 and disassemble the expansion joint 20 when replacing the FBG sensor. Further, it is not necessary to stop the operation of the duct structure 1 provided with the expansion joint 20 and the thermal power generation facility or the like where the duct structure 1 is disposed, and the FBG sensor 40 can be replaced during the operation of the thermal power generation facility and the duct structure 1. In the example described above, the case of replacing the FBG sensor 40 has been described, but the same applies to the replacement of the FBG sensors 41 and 42.

[0030] As described above, the telescopic joint 20 of the first embodiment connects between the first duct 11 and the second duct 12 through which fluid flows, with fluid flowing inside. It includes a first flange 21 connected to the first duct 11, a second flange 22 connected to the second duct 12, a bellows material 23 provided between the first flange 21 and the second flange 22, which has elasticity and prevents fluid from flowing out, a protection tube 37 provided along the circumferential direction inside the bellows material 23, FBG sensors 40, 41, 42 provided inside the protection tube 37, and an introduction part 50 provided on at least one of the bellows material 23, the first flange 21 or the second flange 22, which introduces the protection tube 37 and the FBG sensors 40, 41, 42 into the inside of the bellows material 23. The introduction part 50 is configured to ensure airtightness between the inner and outer sides of at least one of the bellows material 23, the first flange 21 or the second flange 22 where the introduction part 50 is provided. Therefore, the FBG sensor 40 provided inside the bellows material 23 can be easily replaced.

[0031] In addition, since the protection tube 37 is made of stainless steel which is a metal, it has sufficient rigidity and the friction between the FBG sensor 40 and the protection tube 37 is reduced, so that the FBG sensor 40 can be easily inserted into or removed from the protection tube 37.

[0032] Embodiment 2. Next, the telescopic joint according to the second embodiment of the present invention will be described. In the following embodiments, the same reference numerals as those in FIGS. 1 to 4 denote the same or similar components, and thus detailed descriptions thereof are omitted. The telescopic joint according to the second embodiment is provided with a lead-out part for the FBG sensor with respect to the first embodiment. FIG. 5 is a schematic diagram of the upstream duct, downstream duct, and telescopic joint according to the second embodiment of the present invention. Inside the bellows material 23 of the telescopic joint 20 and radially outside the heat insulation part 30, a protection tube 37 made of stainless steel is spirally wound along the circumferential direction, and the FBG sensor 40 is inserted inside the protection tube 37.

[0033] One end of the protective tube 37 is inserted into the introduction part 50, and the other end is led out from the lead-out part 51 provided on the bellows material 23 on the side close to the second flange 22. The FBG sensor 40 accommodated in the protective tube 37 is led out from the inside to the outside of the expansion joint 20 via the lead-out part 51.

[0034] FIG. 6 is a schematic diagram of the expansion joint 20, the protective tube 37, and the FBG sensor 40 according to the second embodiment. For convenience of explanation, in FIG. 6, the description of some components of the expansion joint 20, such as the flanges 21 and 22, is omitted. The protective tube 37 is spirally wound along the circumferential direction on the radially outer side of the heat insulation part 30 of the expansion joint 20. The other end of the protective tube 37 is led out from the lead-out part 51 provided on the bellows material 23 on the side close to the second flange 22 (see FIG. 5). The FBG sensor 40 accommodated in the protective tube 37 is led out from the inside to the outside of the expansion joint 20 via the lead-out part 51. The lead-out part 51 is configured to be able to maintain the airtightness between the outside and the inside of the bellows material 23 when the protective tube 37 is inserted.

[0035] As the configuration of the lead-out part 51 provided on the bellows material 23, similar to the introduction part 50, for example, a structure in which the protective tube 37 is inserted between the bonded bellows materials 23, or a structure in which a part of the bellows material 23 is perforated to insert the protective tube 37 and then the perforated part is sealed with a sealing member may be used. Also, the lead-out part 51 may be provided on the bellows material 23 on the side close to the first flange 21.

[0036] As the configuration of the lead-out portion 51 provided in the bellows member 23, for example, a configuration in which a protective tube 37 is inserted between the bonded bellows members 23, a configuration in which a part of the bellows member 23 is perforated to insert the protective tube 37, and then the perforated portion is sealed with a sealing member, etc. may be used. Further, the lead-out portion 51 can also be provided on the first flange 21 or the second flange 22. As the configuration of the lead-out portion 51 provided on the first flange 21 or the second flange 22, for example, a configuration in which a part of the first flange 21 or the second flange 22 is perforated to insert the protective tube 37, and then the perforated portion is sealed with a sealing member may be used, or a configuration in which a notch portion into which the protective tube 37 can be inserted is previously formed by press forming or the like in a part of the first flange 21 or the second flange 22 may be used.

[0037] The other end of the protective tube 37 protrudes outside the lead-out portion 51, and the FBG sensor 40 is not housed in the protective tube 37 but is exposed on the distal side from the lead-out portion 51. The FBG sensor 40 is connected to an interrogator 44 provided outside the expansion joint 20. The interrogator 44 has a light source device that makes light incident on the FBG sensor 40 and an optical wavelength measurement device that measures and analyzes the wavelength of the reflected light from each diffraction grating, and is housed and disposed in an appropriate weatherproof case. Other configurations are the same as those in the first embodiment.

[0038] Thus, the expansion joint 20 according to the second embodiment is provided on at least one of the bellows member 23, the first flange 21, or the second flange 22, and includes a lead-out portion 51 from which the protective tube 37 and the FBG sensor 40 introduced into the inside of the bellows member 23 from the introduction portion 50 are led out. The lead-out portion 51 is configured to ensure airtightness between the inside and the outside of at least one of the bellows member 23, the first flange 21, or the second flange 22 where the lead-out portion 51 is provided. Therefore, the FBG sensor 40 introduced from the protective tube 37 of the introduction portion 50 can be led out from the protective tube 37 of the lead-out portion 51, and the FBG sensor 40, which is introduced from the outside of the expansion joint 20 into the inside of the bellows member 23, passes through the inside of the bellows member 23 and is led out to the outside of the expansion joint 20, can be easily provided.

[0039] In addition, in the first and second embodiments, the protective tube 37 was formed of stainless steel. However, as long as it is a metal material that can ensure sufficient rigidity and has a small frictional force with the FBG sensor 40, it may be formed using any metal material other than stainless steel.

[0040] Also, in the configuration of the expansion joint 20 of the second embodiment, a guiding wire may be used to provide the FBG sensor 40 inside the bellows material 23 of the expansion joint 20. Connect a guiding wire (not shown) for guiding the FBG sensor 40 to the FBG sensor 40, introduce this guiding wire from the protective tube 37 provided in the introduction part 50 to the inside of the bellows material 23 of the expansion joint 20, and further introduce this guiding wire from the protective tube 37 provided in the lead-out part 51 to the outside of the bellows material 23 of the expansion joint 20. By doing so, the FBG sensor 40 connected to the guiding wire can be introduced from the outside to the inside of the bellows material 23 and led out from the inside to the outside of the bellows material 23. By using such a guiding wire in this way, even when using an FBG sensor 40 with a small diameter and low rigidity, the possibility that the FBG sensor 40 is bent and cannot be introduced inside the bellows material 23 is reduced.

[0041] Embodiment 3. Next, Embodiment 3 of the present invention will be described. The expansion joint according to Embodiment 3 is obtained by changing the material of the protective tube with respect to Embodiment 1. FIG. 7 is a cross-sectional view of the protective tube 37a and the FBG sensors 40, 41, 42 according to the third embodiment, cut along the radial direction. The protective tube 37a is formed of polytetrafluoroethylene (PTFE), which is a resin. Other configurations are the same as those in the first embodiment.

[0042] PTFE has sufficient rigidity to insert the FBG sensors 40, 41, and 42 into the protective tube 37a and has a lower coefficient of friction than common metals. Therefore, by using PTFE for the protective tube 37a, when inserting or removing the FBG sensors 40, 41, and 42, the insertion or removal operation becomes easier, and there is an advantage that the possibility of damaging the FBG sensors 40, 41, and 42 during the insertion or removal operation is reduced.

[0043] Also, PTFE has a lower thermal conductivity than common metals. Therefore, the temperature change generated in the heat insulation part 30 or the bellows material 23 is less likely to be transmitted to a distant location via the protective tube 37a, and there is an advantage that it is easy to clearly identify the position on the heat insulation part 30 or the bellows material 23 where the temperature change has occurred by the FBG sensors 40, 41, and 42.

[0044] Thus, in the expansion joint according to the third embodiment, since the protective tube 37a is formed of PTFE which is a resin, the friction between the FBG sensors 40, 41, and 42 and the protective tube 37a is reduced, and the FBG sensors 40, 41, and 42 can be easily inserted or removed with respect to the protective tube 37a.

[0045] Embodiment 4. Next, Embodiment 4 of the present invention will be described. The expansion joint according to Embodiment 4 is obtained by changing the material inside the protective tube in the radial direction with respect to Embodiment 1. FIG. 8 is a cross-sectional view of the protective tube 37b and the FBG sensors 40, 41, and 42 according to Embodiment 4 cut along the radial direction. The outer member 37c on the outer side in the radial direction of the protective tube 37b is formed of stainless steel, and the inner member 37d on the inner side in the radial direction is formed of PTFE. Other configurations are the same as those in Embodiment 1.

[0046] As described above, in the expansion and contraction joint according to the fourth embodiment, since the inner member 37d of the protective tube 37b that contacts at least the FBG sensors 40, 41, and 42 is formed of PTFE, which is a resin, and the outer member 37c, which is the radially outer portion, is formed of stainless steel, which is a metal, the friction between the FBG sensors 40, 41, and 42 and the protective tube 37b is reduced, and the FBG sensors 40, 41, and 42 can be easily inserted into or removed from the protective tube 37b, and the durability and weather resistance of the protective tube 37b can be improved.

[0047] Note that the non-metallic resin material that can be used for the protective tube 37a in the third embodiment and the protective tube 37b in the fourth embodiment is not limited to PTFE, and resins other than PTFE may be used. For example, resin materials such as polyetheretherketone, polyphenylene sulfide, or heat-resistant rubber such as heat-resistant silicone rubber can be appropriately used. Also, by adopting the same material for the resin material used for the protective tubes 37a and 37b and the material of the bellows material 23, the thermal conductivity of the contact portions of the protective tubes 37a and 37b with the FBG sensors 40, 41, and 42 becomes the same as that of the bellows material 23, so that the possibility that the bellows material 23 is excessively affected by heat due to the heat conducted to the protective tubes 37a and 37b can be reduced.

[0048] Also, the protective tube 37 in the fourth embodiment can ensure sufficient rigidity, and may be formed using any metal material other than stainless steel as long as it is a metal material with a small frictional force with the FBG sensors 40, 41, and 42.

[0049] In addition, the number of FBG sensors, the number of diffraction gratings of the FBG sensors, and the positions of the diffraction gratings in Embodiments 1 to 4 may be determined corresponding to the temperature detection positions required in the expansion joint 20. For example, the FBG sensors and the diffraction gratings may be arranged so as to be able to detect the overall temperature change of the heat insulation part 30 and the bellows material 23, or the FBG sensors and the diffraction gratings may be arranged so as to be able to detect the temperature change of a part of the heat insulation part 30 or the bellows material 23. Further, the FBG sensors and the diffraction gratings may be arranged on the flanges 21, 22, etc. of the expansion joint 20. Furthermore, all the protective tubes 37 may be provided on the radially outer side of the first heat insulation member 31.

[0050] Also, the expansion joint 20 according to Embodiments 1 to 4 of the present invention was arranged in the duct structure 1 provided in the thermal power generation facility, but the facility in which the duct structure 1 is provided is not limited to this, and it may be a duct structure 1 provided in various facilities such as factory facilities.

[0051] Also, in Embodiments 1 to 4 of the present invention, the FBG sensor was arranged on the radially outer side of the heat insulation part 30 and on the radially inner side of the bellows material 23, but the position where the FBG sensor is arranged is not limited to this. For example, among the first heat insulation member 31, the second heat insulation member 32, the third heat insulation member 33, the fourth heat insulation member 34, and the fifth heat insulation member 35 that constitute the heat insulation part 30, it may be arranged between adjacent heat insulation members such as between the third heat insulation member 33 and the fourth heat insulation member 34.

[0052] Note that the components included in Embodiments 1 to 4 of the present invention and the components included in the modified examples thereof can be used in appropriate combinations.

[0053] As described above, the preferred embodiments and the like have been described in detail, but the present invention is not limited to the above-described embodiments and the like, and various modifications and substitutions can be made to the above-described embodiments and the like without departing from the scope described in the claims.

[0054] Hereinafter, the aspects of the present disclosure will be summarized and described as appended notes.

[0055] (Appendix 1) An expansion joint that connects between a first duct and a second duct through which a fluid flows and through which the fluid flows inside, a first flange connected to the first duct, a second flange connected to the second duct, an outflow prevention portion provided between the first flange and the second flange, having elasticity and preventing outflow of the fluid, a tubular protection member provided along the circumferential direction inside the outflow prevention portion, a linear sensor provided inside the tubular protection member, an introduction portion provided on at least one of the outflow prevention portion, the first flange, or the second flange, and introducing the tubular protection member and the linear sensor into the inside of the outflow prevention portion and comprising, The introduction portion is an expansion joint configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention portion, the first flange, or the second flange where the introduction portion is provided. (Appendix 2) Comprising a lead-out portion provided on at least one of the outflow prevention portion, the first flange, or the second flange, and leading out the tubular protection member and the linear sensor introduced into the inside of the outflow prevention portion from the introduction portion, The lead-out portion is the expansion joint according to Appendix 1 configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention portion, the first flange, or the second flange where the lead-out portion is provided. (Appendix 3) The tubular protection member is the expansion joint according to Appendix 1 or 2 formed of metal. (Appendix 4) The tubular protection member is the expansion joint according to Appendix 1 or 2 formed of resin. (Appendix 5) The tubular protection member is the expansion joint according to Appendix 1 or 2, wherein an inner radial portion in contact with the linear sensor is formed of resin, and an outer radial portion is formed of metal.

Explanation of Reference Numerals

[0056] 11 upstream duct (first duct), 12 downstream duct (second duct), 21 first flange, 22 second flange, 23 bellows material (outflow prevention part), 30 heat insulation part, 37 protection tube (tubular protection member), 37a protection tube (tubular protection member), 37b protection tube (tubular protection member), 40 FBG sensor (linear sensor), 41 FBG sensor (linear sensor), 42 FBG sensor (linear sensor), 50 introduction part, 51 lead-out part.

Claims

1. An expansion joint that connects between a first duct and a second duct through which a fluid flows and through which the fluid flows inside, a first flange connected to the first duct, a second flange connected to the second duct, an outflow prevention part provided between the first flange and the second flange, having elasticity and preventing the outflow of the fluid, a tubular protection member provided along the circumferential direction inside the outflow prevention part, a linear sensor provided inside the tubular protection member, and an introduction part provided in at least one of the outflow prevention part, the first flange or the second flange, and introducing the tubular protection member and the linear sensor into the inside of the outflow prevention part. The expansion joint is provided with: The introduction part is an expansion joint configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention part, the first flange or the second flange where the introduction part is provided.

2. An extraction part is provided in at least one of the outflow prevention part, the first flange or the second flange, and the tubular protection member and the linear sensor introduced into the inside of the outflow prevention part from the introduction part are extracted. The extraction part is the expansion joint according to Claim 1, configured to ensure airtightness between the inside and the outside of at least one of the outflow prevention part, the first flange or the second flange where the extraction part is provided.

3. The expansion joint according to Claim 1 or 2, wherein the tubular protection member is formed of metal.

4. The expansion joint according to Claim 1 or 2, wherein the tubular protection member is formed of resin.

5. The expansion joint according to Claim 1 or 2, wherein a radially inner part of the tubular protection member that contacts the linear sensor is formed of resin, and a radially outer part is formed of metal.

Images