Expansion joint

Abstract

To provide an expansion joint capable of introducing a sensor to an inner side of a bellows material while maintaining airtightness of the bellows material when the sensor is provided in the inner side of the bellows material of the expansion joint.SOLUTION: An expansion joint 20 for connecting an upstream side duct 11 and a downstream side duct 12 through which fluid flows so that the fluid flows therein includes: a bellows material 23 provided between the upstream side duct 11 and the downstream side duct 12, having elasticity, and preventing the fluid from flowing out; a heat insulation portion 30 provided in the inner side of the bellows material 23 and insulating heat of the fluid; and an FBG sensor 40 provided in the inner side of the bellows material 23. The bellows material 23 is cylindrically formed along a circumferential direction, and the FBG sensor 40 of the bellows material 23 is introduced into the inner side of the bellows material 23 via a junction 28 of the bellows material 23.SELECTED DRAWING: Figure 5

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 connects a pair of flanges formed to be connectable to a duct with a cylindrical non-metallic bellows material having expansion flexibility and a heat insulation part provided inside the bellows material, and a plurality of temperature fuses are arranged in the heat insulation part. Then, by detecting the open state of the temperature fuses through the conducting wires connected to 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] In the expansion joint described in Patent Document 1, in order to detect the open state of the temperature fuses arranged in the heat insulation part, it is necessary to introduce conducting wires for connecting to the temperature fuses inside the expansion joint. However, when providing through-holes for introducing the conducting wires inside the expansion joint in the bellows material, there is a problem that it becomes difficult to maintain the airtightness of the bellows material.

[0005] The present invention has been made to solve such problems, and when a sensor is provided inside the bellows material of an expansion joint, an object thereof is to provide an expansion joint capable of introducing the sensor into the inside of the bellows material while maintaining the airtightness of the bellows material.

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 is provided between the first duct and the second duct, and has an outflow prevention portion that has elasticity and prevents the outflow of the fluid, and a sensor provided inside the outflow prevention portion. The outflow prevention portion is formed in a cylindrical shape along the circumferential direction and has a joint portion between the ends. The sensor is introduced from the outside of the outflow prevention portion into the inside of the outflow prevention portion via the joint portion of the outflow prevention portion.

[0007] Further, the joint portion may be formed such that the inner surface of one end portion of the outflow prevention portion and the inner surface of the other end portion of the outflow prevention portion are joined and protrude outward in the radial direction of the outflow prevention portion. Further, the outflow prevention portion may be configured by joining a plurality of outflow prevention members, and at least two joint portions may be formed by joining the ends of the outflow prevention members adjacent to each other among the plurality of outflow prevention members. Further, the sensor may be led out from the inside of the outflow prevention portion to the outside of the outflow prevention portion via at least one of the joint portions of the outflow prevention portion. Further, a plurality of sensors may be provided adjacent to each other at the joint portion of the outflow prevention portion. Further, a plurality of sensors may be provided at intervals from each other at the joint portion of the outflow prevention portion. Further, a filling member may be filled in the gap between the joint portion and the sensor. Further, it may have a fluid pipeline through which a heat medium can flow inside, and the fluid pipeline may be introduced from the outside of the outflow prevention portion into the inside of the outflow prevention portion via the joint portion, and led out from the inside of the outflow prevention portion to the outside of the outflow prevention portion via the joint portion.

Effects of the Invention

[0008] The expansion joint according to the present invention includes an outflow prevention part having elasticity and preventing the outflow of fluid, and a sensor provided inside the outflow prevention part. The outflow prevention part is formed in a cylindrical shape along the circumferential direction and has a joint part between the ends. Since the sensor is introduced from the outside of the outflow prevention part to the inside of the outflow prevention part via the joint part of the outflow prevention part, when the sensor is provided inside the bellows material of the expansion joint, the sensor can be introduced into the inside of the bellows material while maintaining the airtightness of the bellows material.

Brief Description of the Drawings

[0009]

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Embodiments 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 diagram of a non-metallic expansion joint in Embodiment 1. In Embodiment 1, the duct structure 1 arranged 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 arranged 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 the variation 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 tubular shape can also be used.

[0011] The expansion joint 20 has a flange 21 connected to the upstream duct 11, a flange 22 connected to the downstream duct 12, and a bellows material 23 provided between the flange 21 and the flange 22 for hermetically connecting these flanges. The pair of 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 duct flange 14 is formed on the upstream duct 11, and the flange 21 is formed to correspond to the duct flange 14. By connecting (for example, fastening with bolts, etc.) the flange 21 and the duct flange 14, the expansion joint 20 and the upstream duct 11 are hermetically connected. A duct flange 15 is formed on the downstream duct 12, and the flange 22 is formed to correspond to the duct flange 15. By connecting (for example, fastening with bolts, etc.) the flange 22 and the duct flange 15, the expansion joint 20 and the downstream duct 12 are hermetically connected. Also, the flanges 21 and 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. Then, by installing 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 formed as a cylindrical body with a tip smaller than the inner diameter of the downstream duct 12 is provided downstream of the upstream duct 11. 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 the flange 21 and the flange 22 on the outermost side in the radial direction, which prevents the outflow of the fluid flowing through the upstream duct 11 and the downstream duct 12. The bellows material 23 is a cloth-like member formed by laminating four-layered laminar members of a first bellows member 24, a second bellows member 25, a third bellows member 26, and a fourth bellows member 27 in order from the outside in the radial direction. Further, the bellows material 23 is configured to have expansion and contraction flexibility along the outflow direction of the fluid indicated by the arrow A and the direction intersecting the outflow 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 arbitrary 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 by a four-layer member. For example, it can be configured by a one- to three-layer member, or can be configured by a five-layer or more member. Further, the first bellows member 24, the second bellows member 25, the third bellows member 26, and the fourth bellows member 27 can be appropriately formed by adopting any known material such as PTFE (polytetrafluoroethylene), inorganic fiber cloth such as glass cloth, metal fiber cloth, and film resin.

[0015] Further, the expansion joint 20 has a heat insulation part 30 on the radially inner side of the bellows material 23. The heat insulation part 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 insulation part 30 is composed of five layers of heat insulation members, namely, a first heat insulation member 31, a second heat insulation member 32, a third heat insulation member 33, a fourth heat insulation member 34, and a fifth heat insulation member 35, which are laminated in order from the radially outer side. 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 constituting the heat insulation part 30 can include any layer as a heat insulation layer to satisfy conditions such as heat insulation performance, and the heat insulation part 30 can be formed by combining such arbitrary layers in any suitable order. Further, the heat insulation part 30 is not limited to the 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.

[0016] In addition, the materials of 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 constituting the heat insulation part 30 can be appropriately formed by adopting any known material. 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 can be, for example, inorganic fiber felts such as glass felt, ceramic felt, and alumina felt wrapped with inorganic fiber cloth such as glass cloth, ceramic cloth, and alumina cloth, and then wrapped with a mesh (such as a mesh) knitted with an appropriate metal wire such as a steel wire such as a stainless steel wire, an Inconel (registered trademark) wire, or a copper wire. Alternatively, it can be wrapped with an organic fiber or an organic film such as PTFE.

[0017] On the radially outer sides of the first heat insulation member 31 and the second heat insulation member 32 of the expansion joint 20, a protective pipe 37 made of stainless steel is spirally wound along the circumferential direction of the expansion joint 20, and an FBG sensor 40 is inserted inside the protective pipe 37. That is, the FBG sensor 40 is disposed on the radially outer side of the heat insulation part 30 and on the radially inner side of the bellows material 23.

[0018] FIG. 3 is a cross-sectional view of the protective tube 37 and the FBG sensor 40 according to Embodiment 1, cut along the radial direction. That is, the FBG sensor 40 is housed by the protective tube 37 formed of stainless steel and is wound around the outside in the radial direction of the heat insulation part 30 shown in FIG. 2.

[0019] FIG. 4 is a schematic diagram of the FBG sensor 40 provided in the expansion joint 20 according to Embodiment 1. For convenience of explanation, in FIG. 4, the description of some components of the expansion joint 20, such as the flanges 21 and 22, the bellows material 23, and the protective tube 37, is omitted. The FBG sensor 40 is wound three times in a clockwise spiral as viewed from the downstream side in the fluid flow direction indicated by arrow A on the outside in the radial direction of the heat insulation part 30 of the expansion joint 20. That is, the FBG sensor 40 is wound three times in a spiral along the circumferential direction inside the radial direction of the bellows material 23 (see FIG. 2).

[0020] The FBG sensor 40 is an optical fiber having a clad part with its surface coated with a polyimide resin and a core part disposed inside the clad part, and a plurality of diffraction gratings 43 formed in the core part by laser processing are provided at predetermined intervals in the extending direction of the optical fiber. It is an optical fiber temperature sensor. Since the FBG sensor 40 is wound in a spiral on the outside in the radial direction of the heat insulation part 30, a plurality of diffraction gratings 43 are arranged in both the fluid flow direction indicated by arrow A and the circumferential direction of the heat insulation part 30 of the expansion joint 20. Note that diffraction gratings 43 are also arranged in the part of the FBG sensor 40 that is hidden by the expansion joint 20 and shown by a broken line in FIG. 4.

[0021] 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 a light wavelength measuring device that measures and analyzes the wavelength of the reflected light from each diffraction grating 43, and is housed and arranged in a suitable weatherproof case.

[0022] FIG. 5 is a schematic perspective view showing the bellows material 23 of the expansion joint 20 according to the first embodiment. The bellows material 23 is formed in a cylindrical shape along the circumferential direction of the expansion joint 20. This bellows material 23 is formed such that the longitudinal length at the time of cutting is longer than the circumferential length of the expansion joint 20. The first end portion 28a and the second end portion 28b of the bellows material 23 in the direction along the circumferential direction of the expansion joint 20 constitute a cloth-like joint portion 28 joined to each other and integrated. This joint portion 28 is formed by joining the surfaces that are continuous with the surfaces of the first end portion 28a and the second end portion 28b of the bellows material 23 facing the inner side in the radial direction of the expansion joint 20, and is provided protruding to the outer side in the radial direction of the expansion joint 20. Thereby, the joint portion 28 is formed to be rotatable so as to be turned along the circumferential direction of the expansion joint 20 with the base portion as a fulcrum. Between the first end portion 28a and the second end portion 28b of the joint portion 28, a protective tube 37 and an FBG sensor 40 disposed inside the protective tube 37 are provided, and the protective tube 37 and the FBG sensor 40 are introduced into the inside of the expansion joint 20 from the joint portion 28. That is, the joint portion 28 constitutes an introduction path for the protective tube 37 and the FBG sensor 40. The protective tube 37 is provided on the outside of the joint portion 28 by a predetermined length. In the first embodiment, the joint portion 28 is formed in a cloth-like shape that is rotatable so as to be turned along the circumferential direction of the expansion joint 20, but the present invention is not limited to this, and any configuration and shape that are not fixed at a certain position as a whole and are freely movable may be used.

[0023] FIG. 6 is a schematic view showing the joint surface of the first end portion 28a and the second end portion 28b of the joint portion 28 shown in FIG. 5 as viewed from the radially outer side. In the region B where the protective tube 37 is not disposed on the joint surface between the first end portion 28a and the second end portion 28b, the first end portion 28a and the second end portion 28b are integrated by heat fusion. Further, in the region C where the protective tube 37 is disposed on the joint surface between the first end portion 28a and the second end portion 28b, the first end portion 28a and the second end portion 28b are not heat-fused. Thereby, the region C of the first end portion 28a and the second end portion 28b constitutes an introduction path through which the protective tube 37 and the FBG sensor 40 can be inserted or removed. Further, in the region C, the first end portion 28a and the second end portion 28b may be provided in close contact with the protective tube 37, or may be provided in contact with the protective tube 37 to such an extent that they are not in close contact. Note that the joining means in the region B of the first end portion 28a and the second end portion 28b is not limited to integration by heat fusion, and any joining means such as adhesion using an adhesive may be used.

[0024] Next, the operation of the expansion joint 20 according to the first embodiment will be described. The thermal power generation facility or the like of the first embodiment has a duct structure 1 provided with the expansion joint 20 shown in FIG. 1. During the operation of the thermal power generation facility or the like, high-temperature gas flows inside the duct structure 1 and the expansion joint 20. The interrogator 44 shown in FIG. 4 emits light to the FBG sensor 40 and measures and analyzes the wavelength of the reflected light from each diffraction grating 43.

[0025] During the operation of a thermal power generation facility or the like, if damage occurs to a part of the heat insulation section 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 the heat of the fluid flowing inside will partially decrease. Therefore, the temperature of the heat insulation section 30, the bellows material 23, and their surroundings on the radially outer side of the location where the heat insulation performance of the heat insulation section 30 has decreased will increase compared to before the occurrence of the decrease in heat insulation performance. As a result, the temperature of the diffraction grating 43 (see Fig. 4), which is arranged near the location where the heat insulation performance of the heat insulation section 30 has decreased, will increase. Due to this increase in the temperature of the diffraction grating 43, the wavelength of the reflected light from the diffraction grating 43 changes (shifts) corresponding to the increase 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 to detect which diffraction grating 43 among the diffraction gratings 43 provided in the FBG sensor 40 has a temperature change. And near the diffraction grating 43 where the temperature change has occurred, it is possible to identify that the heat insulation section 30 has deteriorated. That is, it is possible to identify the location where the heat insulation section 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 section 30 and its surroundings located on the radially inner side of the location where the damage has occurred may increase or decrease compared to before the occurrence of the damage. As a result, the temperature of the diffraction grating 43 (see Fig. 4), which is arranged near the location where the damage has occurred, will increase or decrease. Due to this increase or decrease in the temperature of the diffraction grating 43, the wavelength of the reflected light from the diffraction grating 43 changes. The interrogator 44 measures the change in the wavelength of this reflected light, compares it with the wavelength before the change, and analyzes it to detect which diffraction grating 43 of the FBG sensor 40 has a temperature change. And near the diffraction grating 43 where the temperature change has occurred, it is possible to identify that the bellows material 23 has been damaged. That is, it is possible to identify the location where the bellows material 23 of the expansion joint 20 has been damaged.

[0027] In a conventional expansion joint, as a means of providing a sensor such as an FBG sensor inside a bellows material, a means of providing a through-hole in the bellows material and introducing the sensor itself or a conducting wire connected to the sensor into this through-hole has been used in some cases. However, when using such a means, since the length of the through-hole in the direction along the radial direction of the expansion joint 20 (that is, the length from the inlet to the outlet) of the bellows material is only the thickness of the bellows material, there has been a problem that it becomes difficult to maintain airtightness even when using a filler or the like.

[0028] On the other hand, in the first embodiment, in the assembly of the expansion joint 20 shown in FIG. 2, the protective tube 37 is wound around the heat insulating portion 30, and the first end portion 28a and the second end portion 28b of the bellows material 23 are joined in a state where the vicinity of the end portion of the protective tube 37 is sandwiched as shown in FIGS. 5 and 6, and the end portion of the protective tube 37 is provided outside the joint portion 28 by a predetermined length. Thereafter, the FBG sensor 40 is inserted into the protective tube 37 and the FBG sensor 40 is wound around the heat insulating portion 30. Thereby, from the joint portion 28, the protective tube 37 and the FBG sensor 40 are introduced into the inside of the bellows material 23. Further, in the region C of the joint surface between the first end portion 28a and the second end portion 28b of the joint portion 28, since the first end portion 28a and the second end portion 28b are in close contact with the protective tube 37 or the first end portion 28a and the second end portion 28b are in contact with the protective tube 37, there is no gap or almost no gap between the first end portion 28a and the second end portion 28b and the protective tube 37, and since the length from the inlet to the outlet of the through-hole has a length that crosses the joint portion 28, while maintaining the airtightness of the bellows material 23, the FBG sensor 40 is introduced from the outside to the inside of the bellows material 23.

[0029] Also, in a conventional expansion joint, as described above, since the length of the through-hole in the direction along the radial direction of the expansion joint 20 of the bellows material is only the thickness of the bellows material, even when using a filler or the like, it is difficult to maintain strength due to the presence of the through-hole, and there has been a problem that the possibility of damage from the vicinity of the through-hole increases when the internal pressure of the fluid is applied.

[0030] On the one hand, in the first embodiment, since the through hole formed in the region C of the joint 28 between the first end portion 28a and the second end portion 28b has a length from the inlet to the outlet that crosses the joint 28, even when the internal pressure of the fluid is applied, the strength of the through hole is maintained, and there is an advantage that the possibility of damage to the bellows material 23 from the vicinity of the through hole is reduced.

[0031] Also, in a conventional expansion joint, as a means for providing a sensor such as an FBG sensor inside the bellows material, a through hole is provided in a metal flange that holds the bellows material and the heat insulating material, and the sensor itself or a wire connected to the sensor is introduced into this through hole, or the sensor itself or the wire of the sensor is introduced into the joint surface between the flange and the bellows material. However, in this case, in order to supplement the airtightness of the location where the sensor itself or the wire of the sensor is introduced with a gasket or a sealant, etc., there is no freedom in the introduction position or angle of the sensor, etc., and also, since the metal flange becomes hot, there is a problem that the deterioration rate of the sealant and the sensor is accelerated. Furthermore, when introducing the sensor itself or the wire connected to the sensor into the expansion joint in this way, since the introduction direction and the expansion and contraction direction of the expansion joint are substantially the same direction, and the fixing of the sensor itself or the wire connected to the sensor is strong, the sensor bends due to the movement of the bellows material or the heat insulating material, etc. caused by the expansion and contraction of the expansion joint, and also, due to the operation of the facility having the pipe where the expansion joint is provided, the vibration of the duct is transmitted to the expansion joint, and the strain due to the vibration concentrates at the fixing location of the sensor of the expansion joint, so there is a problem that the deterioration rate of the sensor is accelerated.

[0032] On the one hand, in Embodiment 1, the joint 28, which is the introduction path of the protective tube 37 and the FBG sensor 40, is a part of the flexible bellows material 23 and is formed so as to be rotatable along the radial direction of the expansion joint 20 with the base as a fulcrum. Therefore, the degrees of freedom such as the insertion position and angle of the FBG sensor 40 are increased. Further, since the protective tube 37 and the FBG sensor 40 are introduced from this joint 28, the thermal conductivity to the FBG sensor 40 is reduced, and further the transmission of vibration to the FBG sensor 40 is reduced. Therefore, the possibility that the FBG sensor 40 fails due to heat or vibration can be reduced.

[0033] Also, in Embodiment 1, in region C of the joint 28 of the bellows material 23, since the first end 28a and the second end 28b are not joined, when it becomes necessary to replace the FBG sensor 40 or the protective tube 37, the FBG sensor 40 and the protective tube 37 can be easily replaced without disassembling the expansion joint 20.

[0034] As described above, the expansion joint 20 of Embodiment 1 is an expansion joint 20 that connects between the upstream duct 11 and the downstream duct 12 through which fluid flows and through which fluid flows inside. It is provided between the upstream duct 11 and the downstream duct 12 and has a bellows material 23 having elasticity to prevent fluid outflow, a heat insulating portion 30 provided inside the bellows material 23 to insulate the heat of the fluid, and an FBG sensor 40 provided inside the bellows material 23. Further, the bellows material 23 is formed in a cylindrical shape along the circumferential direction and has a joint 28 with the first end 28a and the second end 28b. The FBG sensor 40 of the bellows material 23 is introduced from the outside of the bellows material 23 to the inside of the bellows material 23 via the joint 28 of the bellows material 23. Therefore, it is possible to provide an expansion joint capable of introducing the FBG sensor 40 into the inside of the bellows material 23 while maintaining the airtightness of the bellows material 23.

[0035] Further, since the joint portion 28 is formed such that the inner surface of the first end portion 28a of the bellows material 23 and the inner surface of the second end portion 28b of the bellows material 23 are joined and project outward in the radial direction of the bellows material 23, the degree of freedom in the insertion position and angle of the FBG sensor 40 is increased, the thermal conductivity to the FBG sensor 40 is reduced, and further the transmission of vibration to the FBG sensor 40 is reduced. Therefore, the possibility that the FBG sensor 40 fails due to heat or vibration can be reduced.

[0036] Embodiment 2. Next, a telescopic joint according to Embodiment 2 of the present invention will be described. In the following embodiments, the same reference numerals as those in FIGS. 1 to 6 denote the same or similar components, and thus the detailed description thereof will be omitted. The telescopic joint according to Embodiment 2 is further provided with a joint portion provided with a lead-out path for the FBG sensor with respect to Embodiment 1. FIG. 7 is a schematic perspective view showing the bellows material of the telescopic joint 20 according to the second embodiment. The first bellows material 50 and the second bellows material 51 that constitute the bellows material are formed in a cylindrical shape along the circumferential direction of the telescopic joint 20. The longitudinal length of the first bellows material 50 at the time of cutting is formed to be longer than the longitudinal length of the second bellows material 51 at the time of cutting. Further, the total length of the longitudinal lengths of the first and second bellows materials 50 and 51 at the time of cutting is formed to be longer than the circumferential length of the telescopic joint 20.

[0037] In the direction along the circumferential direction of the telescopic joint 20, the first end portion 52a of the first bellows material 50 and the second end portion 52b of the second bellows material 51 are joined to each other to form a first joint portion 52. This first joint portion 52 is formed by joining the surfaces that are continuous with the surfaces of the first end portion 52a of the first bellows material 50 and the second end portion 52b of the second bellows material 51, which face the inner side in the radial direction of the telescopic joint 20, and is provided so as to protrude to the outer side in the radial direction of the telescopic joint 20. As a result, the first joint portion 52 is formed to be rotatable along the radial direction of the telescopic joint 20 around the base. Between the first end portion 52a of the first bellows material 50 and the second end portion 52b of the second bellows material 51 that constitute the first joint portion 52, the protective tube 37 and the FBG sensor 40 disposed inside the protective tube 37 are introduced from the outside to the inside of the telescopic joint 20. That is, the first joint portion 52 constitutes an introduction path for the FBG sensor 40. The protective tube 37 is provided on the outside of the telescopic joint 20 by a predetermined length.

[0038] In the direction along the circumferential direction of the telescopic joint 20, the second end portion 53a of the first bellows material 50 and the first end portion 53b of the second bellows material 51 are joined to each other to form a second joint portion 53. This second joint portion 53 is formed by joining the surfaces that are continuous with the surfaces of the second end portion 53a of the first bellows material 50 and the first end portion 53b of the second bellows material 51, which face the inner side in the radial direction of the telescopic joint 20, and is provided so as to protrude to the outer side in the radial direction of the telescopic joint 20. As a result, the second joint portion 53 is formed to be rotatable along the radial direction of the telescopic joint 20 around the base. Between the second end portion 53a of the first bellows material 50 and the first end portion 53b of the second bellows material 51 that constitute the second joint portion 53, the tip sides of the protective tube 37 and the FBG sensor 40, which were introduced into the inside of the telescopic joint 20 from the first joint portion 52, are led out to the outside of the telescopic joint 20. That is, the second joint portion 53 constitutes a lead-out path for the FBG sensor 40. The protective tube 37 is provided on the outside of the telescopic joint 20 by a predetermined length. Other configurations are the same as those in Embodiment 1.

[0039] In the second embodiment, in the assembly of the expansion joint 20, the protective pipe 37 is wound around the heat insulating part 30, and with the protective pipe 37 interposed therebetween, the first end 52a of the first bellows material 50 and the second end 52b of the second bellows material 51 are joined, and the end of the protective pipe 37 is provided outside the first joint part 52 by a predetermined length. Further, with the protective pipe 37 interposed therebetween, the second end 53a of the first bellows material 50 and the first end 53b of the second bellows material 51 are joined, and the end of the protective pipe 37 is provided outside the second joint part 53 by a predetermined length. Thereafter, the FBG sensor 40 is inserted into the protective pipe 37 of the first joint part 52 and the FBG sensor 40 is wound around the heat insulating part 30. Furthermore, the tip of the FBG sensor 40 can be led out from the protective pipe 37 of the second joint part 53 to the outside of the bellows materials 50 and 51.

[0040] In this way, from the first joint part 52, the protective pipe 37 and the FBG sensor 40 are introduced from the outside to the inside of the bellows material 23, and from the second joint part 53, the protective pipe 37 and the FBG sensor 40 are led out from the inside to the outside of the bellows material 23. As a result, similar to the first embodiment, the first end 52a and the second end 52b of the first joint part 52 are in a state of being in close contact with or in contact to a non-close contact degree with the protective pipe 37, and the second end 53a and the first end 53b of the second joint part 53 are in a state of being in close contact with or in contact to a non-close contact degree with the protective pipe 37. Therefore, while maintaining the airtightness of the first bellows material 50 and the second bellows material 51, the FBG sensor 40 is introduced from the outside to the inside of the first bellows material 50 and the second bellows material 51, and is led out from the inside to the outside of the first bellows material 50 and the second bellows material 51.

[0041] As described above, the bellows material of the expansion joint 20 according to the second embodiment is formed by joining the first bellows material 50 and the second bellows material 51. The first joint portion 52 and the second joint portion 53 are formed by joining the first end portions 52a and second end portions 52b of the adjacent bellows materials 50 and 51, and the first end portion 53b and the second end portion 53a. Since two such joint portions are formed, the first joint portion 52 is used as the introduction path of the FBG sensor 40, and the second joint portion 53 is used as the lead-out path of the FBG sensor 40. While maintaining the airtightness of the first bellows material 50 and the second bellows material 51, it is possible to configure the expansion joint 20 capable of introducing the FBG sensor 40 from the outside to the inside of the first bellows material 50 and the second bellows material 51.

[0042] In the second embodiment, two bellows materials of the first bellows material 50 and the second bellows material 51 are used, and two joint portions of the first joint portion 52 and the second joint portion 53 that constitute the introduction path and the lead-out path of the FBG sensor 40 are provided. However, the number of joint portions is not limited to two. Three or more bellows materials may be used to provide three or more joint portions in the bellows, and each may be appropriately used as the introduction path and the lead-out path of the FBG sensor 40.

[0043] Embodiment 3. Next, an expansion joint according to Embodiment 3 of the present invention will be described. The expansion joint according to Embodiment 3 is obtained by providing a plurality of FBG sensors adjacent to the joint portion of the bellows material with respect to Embodiment 1. FIG. 8 is a schematic perspective view showing the bellows material of the expansion joint 20 according to the third embodiment. At the joint portion 28 between the first end portion 28a and the second end portion 28b of the bellows material 23, the protective tube 37 and the FBG sensor 40 are introduced from the outside to the inside of the expansion joint 20. The leading end sides of the introduced protective tube 37 and FBG sensor 40 are led out from the inside to the outside of the expansion joint 20 adjacent to the protective tube 37 and FBG sensor 40 on the introduction side at the joint portion 28 between the first end portion 28a and the second end portion 28b.

[0044] FIG. 9 is a schematic view showing the joint surface between the first end portion 28a and the second end portion 28b of the joint portion 28 shown in FIG. 8. Among the joint surfaces of the first end portion 28a and the second end portion 28b, in the region C where heat fusion is not performed, the protective tube 37 and the FBG sensor 40 introduced from the outside to the inside of the expansion joint 20 and the protective tube 37 and the FBG sensor 40 led out from the inside to the outside of the expansion joint 20 are arranged adjacent to each other in parallel. That is, the joint portion 28 constitutes an introduction path and a lead-out path. Other configurations are the same as those in the first embodiment.

[0045] As described above, in the expansion joint 20 according to the third embodiment, since a plurality of FBG sensors 40 are provided adjacent to the joint portion 28 of the bellows material 23, a plurality of FBG sensors 40 can be collectively and compactly arranged in the region C where the joint portion is not heat-fused.

[0046] In the third embodiment, two protective tubes 37 and FBG sensors 40 are introduced and led out at the joint portion 28, but three or more protective tubes 37 and FBG sensors 40 may be introduced and led out. Further, in the third embodiment, both the protective tube 37 and the FBG sensor 40 introduced from the outside to the inside of the joint portion 28 and the protective tube 37 and the FBG sensor 40 led out from the inside to the outside are provided, but only the protective tube 37 and the FBG sensor 40 introduced from the outside to the inside of the expansion joint 20 may be provided, or only the protective tube 37 and the FBG sensor 40 led out from the inside to the outside may be provided.

[0047] Embodiment 4. Next, an expansion joint according to the fourth embodiment of the present invention will be described. The expansion joint according to the fourth embodiment is obtained by providing a plurality of FBG sensors at intervals on the joint portion of the bellows material with respect to the first embodiment. FIG. 10 is a schematic diagram of the expansion joint 20 and the FBG sensors 40, 41, and 42 according to Embodiment 4. For convenience of explanation, in FIG. 10, descriptions of some components of the expansion joint 20, such as the flanges 21 and 22, the bellows material 23, and the protective tube 37, are omitted. The FBG sensor 40, the FBG sensor 41, and the FBG sensor 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 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 in FIG. 11, which will be described in detail later, at intervals along the circumferential direction and parallel to each other.

[0048] FIG. 11 is a schematic perspective view of the bellows material 23 of the expansion joint 20 according to Embodiment 4. At the joint 28 between the first end portion 28a and the second end portion 28b of the bellows material 23, the protective tube 37 and the FBG sensor 40, the protective tube 37 and the FBG sensor 41, and the protective tube 37 and the FBG sensor 42 are introduced from the outside to the inside of the bellows material 23 at intervals.

[0049] FIG. 12 is a schematic view showing the joint surface between the first end portion 28a and the second end portion 28b of the joint 28 shown in FIG. 11. Regions C1, C2, and C3 where heat fusion is not performed are provided at equal intervals in order on the joint surface between the first end portion 28a and the second end portion 28b. Also, in the region B where the regions C1, C2, and C3 are not provided, the first end portion 28a and the second end portion 28b are integrated by heat fusion. The protective tube 37 and the FBG sensor 40 introduced from the outside to the inside of the expansion joint 20 are provided in the region C1. The protective tube 37 and the FBG sensor 41 introduced from the outside to the inside of the expansion joint 20 are provided in the region C2. The protective tube 37 and the FBG sensor 42 introduced from the outside to the inside of the expansion joint 20 are provided in the region C3. Other configurations are the same as those in Embodiment 1.

[0050] As described above, in the expansion joint 20 of the fourth embodiment, since the plurality of FBG sensors 40, 41, and 42 are provided at intervals from each other at the joint portion 28 of the bellows material 23, the wiring of each sensor when providing the plurality of FBG sensors 40, 41, and 42 to the expansion joint 20 becomes easy.

[0051] Note that, in the expansion joint according to the fourth embodiment, three protective tubes 37 and FBG sensors 40, 41, and 42 were provided at equal intervals at the joint portion 28. However, two of the protective tube 37 and FBG sensor 40 and the protective tube 37 and FBG sensor 41 may be provided at intervals from each other, or four or more protective tubes 37 and FBG sensors may be provided at intervals from each other. Also, the intervals between the respective protective tubes 37 and FBG sensors do not necessarily have to be equal intervals. Further, the protective tubes 37 and FBG sensors 40, 41, and 42 provided at the joint portion 28 may be introduced from the outside to the inside of the bellows material 23, or may be led out from the inside to the outside.

[0052] Embodiment 5. Next, the expansion joint according to the fifth embodiment of the present invention will be described. The expansion joint according to the fifth embodiment is obtained by filling a sealing member in the introduction path of the FBG sensor with respect to the first embodiment. FIG. 13 is a schematic view showing a joint surface between the first end portion 28a and the second end portion 28b of the joint portion 28 of the bellows material 23 according to the fifth embodiment. A gap is formed between the protective tube 37 inserted into the region C where the first end portion 28a and the second end portion 28b of the joint portion 28 are not heat-sealed, and the first end portion 28a and the second end portion 28b. This gap is filled with a silicon sealant 60. By filling this silicon sealant 60, the gap between the protective tube 37 accommodating the FBG sensor 40 and the first end portion 28a and the second end portion 28b can be closed, and the airtightness of the bellows material 23 at the joint portion 28 can be improved. That is, this silicon sealant 60 constitutes a sealing member for improving the airtightness of the bellows material 23. Other configurations are the same as those in the first embodiment.

[0053] As described above, in the expansion joint according to the fifth embodiment, since the silicon sealant 60 is filled between the joint portion 28 and the FBG sensor 40, the airtightness between the joint portion 28 and the FBG sensor 40 can be further improved, and the vibration transmitted to the FBG sensor 40 can be reduced.

[0054] In the fifth embodiment, a silicon sealant is used as the sealing member filled in the gap between the protective tube 37 and the first end portion 28a and the second end portion 28b, but the present invention is not limited thereto. For example, other sealing members such as silylated acrylate-based sealing materials may be used, or a cylindrical sealing member formed of heat-resistant rubber may be used.

[0055] Embodiment 6. Next, Embodiment 6 of the present invention will be described. The expansion joint according to Embodiment 6 is obtained by providing a fluid pipeline at the joint portion of the bellows material with respect to Embodiment 1. FIG. 14 is a schematic perspective view of the bellows material of the expansion joint 20 according to the sixth embodiment. Between the first end portion 28a and the second end portion 28b of the joint portion 28 of the bellows material 23, a protective tube 37 and an FBG sensor 40 disposed inside the protective tube 37 are introduced inside the expansion joint 20.

[0056] Also, between the first end portion 28a and the second end portion 28b of the joint portion 28, a refrigerant pipe 71 disposed at an interval from the protective tube 37 and the FBG sensor 40, and a refrigerant pipe 72 disposed at an interval from the refrigerant pipe 71 are provided. The refrigerant pipes 71 and 72 are connected to a heat exchanger 63 provided outside the expansion joint 20, and constitute a fluid pipeline through which cooling water, which is a fluid, circulates as a refrigerant that is a heat medium.

[0057] FIG. 15 is a schematic view showing the joint surface between the first end portion 28a and the second end portion 28b of the joint portion 28 shown in FIG. 14. In the joint surface between the first end portion 28a and the second end portion 28b, regions C1, C2, and C3 where heat fusion is not performed are provided at equal intervals in order. Also, in region B where regions C1, C2, and C3 are not provided, the first end portion 28a and the second end portion 28b are integrated by heat fusion. In region C1, a protective tube 37 and an FBG sensor 40 introduced from the outside to the inside of the expansion joint 20 are provided. In region C2, a refrigerant pipe 71 introduced from the outside to the inside of the expansion joint 20 is provided. In region C3, a refrigerant pipe 72 led out from the inside to the outside of the expansion joint 20 is provided. Other configurations are the same as those in the first embodiment.

[0058] Next, the operation of the expansion joint 20 of the sixth embodiment will be described with reference to FIGS. 14 and 15. During the operation of the expansion joint 20, cooling water as a refrigerant sent from the heat exchange device 63 flows through the refrigerant pipe 71. The cooling water flows into the inside of the expansion joint 20, flows through a cooling pipe (not shown) provided inside the expansion joint 20, and cools the bellows material 23. Thereafter, the cooling water that has flowed through the cooling pipe flows through the refrigerant pipe 72, flows out of the expansion joint 20, is radiated heat in the heat exchange device 63, and then flows through the refrigerant pipe 71 and flows into the inside of the expansion joint 20. Thereby, the bellows material 23 of the expansion joint 20 can be efficiently cooled, and deterioration of the bellows material 23 due to heat can be suppressed.

[0059] As described above, the expansion joint 20 according to the sixth embodiment has refrigerant pipes 71 and 72 through which a refrigerant can flow inside. The refrigerant pipe 71 is introduced from the outside of the bellows material 23 to the inside of the bellows material 23 via the joint portion 28, and the refrigerant pipe 72 is led out from the inside of the bellows material 23 to the outside of the bellows material 23 via the joint portion 28. Therefore, the bellows material 23 of the expansion joint 20 can be efficiently cooled by the refrigerant flowing through the refrigerant pipes 71 and 72.

[0060] In addition, in the sixth embodiment, cooling water was used as the refrigerant flowing through the refrigerant pipes 71 and 72. However, a known refrigerant gas such as hydrofluorocarbon (HFC) or other types of liquid refrigerants may also be used. Further, instead of the refrigerant pipes 71 and 72, a heat medium pipe may be provided in the expansion joint 20, and a heat medium at 150°C or higher may be circulated through the heat medium pipe to the inner lower surface portions of the bellows material 23 and the flanges 21 and 22. In this case, the generation of strongly acidic drain water due to condensation can be suppressed, and corrosion of the metal parts can be suppressed.

[0061] In addition, in the sixth embodiment, the refrigerant pipes 71 and 72 are provided, and the refrigerant flowing through the refrigerant pipe 71 and flowing into the inside of the expansion joint 20 flows through the cooling pipe inside the expansion joint 20, and the refrigerant flows out of the expansion joint 20 through the refrigerant pipe 72. However, the refrigerant pipe 71 may be introduced into the expansion joint 20, the bellows material 23 may be cooled by the refrigerant flowing through the refrigerant pipe 71, and the refrigerant pipe 71 may be led out of the expansion joint 20 from the inside of the expansion joint 20.

[0062] In addition, in the first to sixth embodiments of the present invention, an FBG sensor was used as the sensor. However, the present invention is not limited to this, and any sensor such as a thermocouple or a temperature fuse may be appropriately used. Further, in the first to sixth embodiments of the present invention, the FBG sensor constituting the sensor itself was introduced into and led out of the expansion joint from the joint portion of the bellows material. However, wires, signal lines, etc. connected to the sensor may be introduced into and led out of the expansion joint from the joint portion of the bellows material.

[0063] In Embodiments 1 to 6 of the present invention, the protective tube 37 made of stainless steel was used. However, instead of this, a protective tube made of another type of metal may be used, or a protective tube made of a resin such as PTFE, polyetheretherketone, polyphenylene sulfide, or heat-resistant silicone rubber may be used. Further, in Embodiments 1 to 6 of the present invention, the protective tube 37 made of stainless steel was used. However, if the environment inside the expansion joint 20 is an environment that can sufficiently withstand the use of the FBG sensor due to the strength and heat resistance of the FBG sensor itself, the FBG sensor may be introduced and led out from the joint portion of the bellows material without providing a protective tube.

[0064] In Embodiments 1 to 6 of the present invention, the FBG sensor was disposed on the radially outer side of the heat insulating portion 30 and on the radially inner side of the bellows material 23. However, the position where the FBG sensor is disposed is not limited to this. For example, among 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 that constitute the heat insulating portion 30, it may be disposed between adjacent heat insulating members such as between the third heat insulating member 33 and the fourth heat insulating member 34.

[0065] Note that the components included in Embodiments 1 to 6 of the present invention and the components included in the modified examples thereof can be used in appropriate combinations.

[0066] Although the preferred embodiments and the like have been described in detail above, 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.

[0067] Hereinafter, aspects of the present disclosure will be summarized and described as appendices.

[0068] (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, An outflow prevention portion that is provided between the first duct and the second duct, has elasticity, and prevents the outflow of the fluid, a sensor provided inside the outflow prevention part and comprises the outflow prevention part is formed in a cylindrical shape along the circumferential direction and has a joint part between the ends of the outflow prevention part, the sensor is a telescopic joint introduced from the outside of the outflow prevention part to the inside of the outflow prevention part via the joint part of the outflow prevention part. (Appendix 2) the joint part is formed such that the inner surface of one end of the outflow prevention part and the inner surface of the other end of the outflow prevention part are joined and project outward in the radial direction of the outflow prevention part, the telescopic joint according to Appendix 1. (Appendix 3) the outflow prevention part is configured by joining a plurality of outflow prevention members, and the joint part is formed by joining at least two ends of the outflow prevention members adjacent to each other among the plurality of outflow prevention members, the telescopic joint according to Appendix 1 or 2. (Appendix 4) the sensor is led out from the inside of the outflow prevention part to the outside of the outflow prevention part via at least one of the joint parts of the outflow prevention part, the telescopic joint according to any one of Appendices 1 to 3. (Appendix 5) a plurality of the sensors are provided adjacent to each other at the joint part of the outflow prevention part, the telescopic joint according to any one of Appendices 1 to 4. (Appendix 6) a plurality of the sensors are provided at intervals from each other at the joint part of the outflow prevention part, the telescopic joint according to any one of Appendices 1 to 4. (Appendix 7) a filling member is filled between the joint part and the sensor, the telescopic joint according to any one of Appendices 1 to 6. (Appendix 8) having a fluid pipeline through which a heat medium can flow, the fluid pipeline is introduced from the outside of the outflow prevention part to the inside of the outflow prevention part via the joint part and led out from the inside of the outflow prevention part to the outside of the outflow prevention part via the joint part, the telescopic joint according to any one of Appendices 1 to 7.

Explanation of Signs

[0069] 11 upstream duct (first duct), 12 downstream duct (second duct), 23 bellows material (outflow prevention part), 28 joint, 28a first end, 28b second end, 30 heat insulation part, 37 protection tube (tubular protection member), 40 FBG sensor (sensor), 41 FBG sensor (sensor), 42 FBG sensor (sensor), 50 first bellows material, 51 second bellows material, 52 first joint, 52a first end, 52b second end, 53 second joint, 53a second end, 53b first end, 60 silicon sealant (filling member), 71 refrigerant pipe (fluid pipeline), 72 refrigerant pipe (fluid pipeline).

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, An outflow prevention part that is provided between the first duct and the second duct, has elasticity, and prevents the outflow of the fluid, A sensor provided inside the outflow prevention part Comprising, The outflow prevention part is formed in a cylindrical shape along the circumferential direction and has a joint part between the ends, The sensor is an expansion joint that is introduced from the outside of the outflow prevention part, through the joint part of the outflow prevention part, into the inside of the outflow prevention part.

2. The joint part is formed such that the inner surface of one end of the outflow prevention part and the inner surface of the other end of the outflow prevention part are joined and project outward in the radial direction of the outflow prevention part. The expansion joint according to claim 1.

3. The outflow prevention part is configured by joining a plurality of outflow prevention members, and the joint part is formed at least in two by joining the ends of the outflow prevention members adjacent to each other among the plurality of outflow prevention members. The expansion joint according to claim 1 or 2.

4. The sensor is led out from the inside of the outflow prevention part, through at least one of the joint parts of the outflow prevention part, to the outside of the outflow prevention part. The expansion joint according to claim 1 or 2.

5. A plurality of the sensors are provided adjacent to the joint part of the outflow prevention part. The expansion joint according to claim 1 or 2.

6. A plurality of the sensors are provided at intervals from each other at the joint part of the outflow prevention part. The expansion joint according to claim 1 or 2.

7. A filling member is filled in the gap between the joint part and the sensor. The expansion joint according to claim 1 or 2.

8. It has a fluid pipeline through which a heat medium can flow inside, and the fluid pipeline is introduced from the outside of the outflow prevention part, through the joint part, into the inside of the outflow prevention part, and led out from the inside of the outflow prevention part, through the joint part, to the outside of the outflow prevention part. The expansion joint according to claim 1 or 2.

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