JP2019120468A - Heat exchanger and leak point segregation method of heat exchanger - Google Patents

Abstract

To prevent the mixture of a first fluid and a second fluid, in a heat exchanger having a first circulation part in which the first fluid circulates, and a second circulation part in which the second fluid circulates, and exchanging heat between the first fluid and the second fluid.SOLUTION: A heat exchanger 1 comprises: a first circulation part 15 which has a first heat transmission face 4s, and in which a first fluid A circulates; and a second circulation part IS which has a second heat transmission face 3s opposing the first heat transmission face 4s, and in which a clearance between the first heat transmission face 4s and itself is made as an inactive space NA, and a second fluid FG different from the first fluid A circulates.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat exchanger and a method of isolating leak points of the heat exchanger.

For example, in a gas turbine, heat exchange is performed between air for cooling a blade and a fuel gas using a heat exchanger to save energy (for example, see Patent Document 1).
As the heat exchanger, for example, a shell and tube type multi-tube type heat exchanger is known. The multi-tube type heat exchanger has a cylindrical casing and a plurality of heat transfer tubes disposed inside the casing in parallel with the axis of the casing.
In the above-described heat exchanger, heat exchange is performed by passing the high-temperature fuel gas through the heat transfer tube and passing the air between the tube sheets.

  Further, as a heat exchanger, a plate type heat exchanger is known which has a plurality of plates and which exchanges heat between high temperature fluid and low temperature fluid in a flow path formed between the respective plates for heat exchange.

JP 2001-296090 A

By the way, various structures are examined in order to prevent that a fuel gas and air mix, when a malfunction arises in a heat exchanger tube or a plate.
In addition, when operating the heat exchanger, it is an issue how to isolate the gas leak due to the deterioration of the heat transfer tube and the like.

  According to the present invention, in a heat exchanger including a first flow portion in which a first fluid flows and a second flow portion in which a second fluid different from the first fluid flows, the first fluid and the second flow portion It is an object of the present invention to provide a heat exchanger capable of preventing mixing with a fluid and a method of isolating leak points of the heat exchanger.

  According to the first aspect of the present invention, the heat exchanger has a first heat transfer surface, and a first flow portion through which a first fluid flows, and a second heat transfer surface facing the first heat transfer surface. And a second flow portion having a thermal surface, which is an inert space between the heat transfer surface and the first heat transfer surface, and in which a second fluid different from the first fluid flows.

  According to such a configuration, there is an inactive space between the first circulation portion, which is a space in which the first fluid flows, and the second circulation portion, which is a space in which the second fluid flows. , Mixing of the first fluid and the second fluid can be prevented.

  In the heat exchanger, a cylindrical casing having a first supply port to which the first fluid is supplied, and a first discharge port to which the first fluid is discharged, and passing through an inner space of the casing , And the inner pipe is accommodated inside to extend in the extension direction of the inner pipe so as to pass through the inner space through which the second fluid flows and the inner pipe. And an outer tube having an inert space between the tubes, wherein the first heat transfer surface is an inner peripheral surface of the outer tube, and the second heat transfer surface is an outer periphery of the inner tube. It may be a plane.

  According to such a configuration, the heat transfer area can be further increased. In addition, the heat exchanger can be manufactured with a simple structure including a plurality of tubes and a cylindrical casing.

  In the above-mentioned heat exchanger, it has a first tube sheet to which one end of the outer tube is connected, and a third tube sheet to which the other end of the outer tube is connected and which is formed independently from the casing. The inner tube includes a first straight portion housed inside the one outer tube, a second straight portion housed inside the other outer tube, the first straight portion, and the second straight portion. A dome portion forming a U-shape having a bend portion to be connected, accommodating the bend portion in cooperation with the third tube plate, and forming a second inert space communicating with the inert space; The third tube sheet and the dome portion may be connected to the casing by a flexible connection portion.

  According to such a configuration, the third tube sheet and the dome portion are supported by the casing via the flexible connection portion, whereby the thermal elongation difference between the third tube sheet and the dome portion and the casing is obtained. Can be absorbed.

  In the heat exchanger, the connection portion may have a sealing property, and a space between the dome portion and the casing may be an inert space.

  According to such a configuration, it is possible to reduce the pressure difference between the second inert space formed by the third tube sheet and the dome portion and the space between the dome portion and the casing.

  In the above-mentioned heat exchanger, it has a first tube sheet to which one end of the outer tube is connected, and the inner tube is provided with a first straight portion accommodated inside the one outer tube, and the other outer side. A U-shape having a second straight portion housed inside a tube, and a bend portion connecting the first straight portion and the second straight portion, the outer tube being the one outer tube In addition to connecting to the other outer tube, it may be U-shaped having an outer tube bend portion for receiving the bend portion inside.

  According to such a configuration, the possibility of mixing the first fluid and the second fluid can be further reduced.

  In the heat exchanger, the first tube sheet, the inner pipe, and the outer pipe may be formed of the same material.

  According to such a configuration, abrasion of the inner pipe and the outer pipe due to the thermal expansion difference can be reduced.

  According to a second aspect of the present invention, there is provided a leak point isolation method for a heat exchanger according to any one of the above-mentioned heat exchanger leak point isolation methods, in the case where a leak occurs in the outer pipe, An inner pipe removing step of drawing out an inner pipe disposed inside the pipe, and a flexible material formed before and after the leak point of the outer pipe in the extension direction of the outer pipe, and the inside is filled with a fluid It has the sealing member arrangement process of arranging the sealing member which expands by doing, and the sealing member expansion process which expands the said sealing member.

  According to such a configuration, even when a leak occurs in the outer tube of the heat transfer tube having a length, it is possible to limitly isolate the leak location. Moreover, workability can be improved by using the sealing member specialized for the outer pipe.

  According to a third aspect of the present invention, there is provided a method of isolating a leak point of a heat exchanger according to any one of the above-mentioned methods of isolating a leak point of a heat exchanger, wherein the leak is generated in the outer pipe. Inside the tube, before and after the leak point of the outer tube in the extension direction of the outer tube, a sealing member formed of a flexible material and expanding by filling the fluid inside is disposed And a sealing member expanding step of expanding the sealing member.

  According to such a configuration, it is possible to isolate the leak location without pulling out the inner pipe.

  In the leak point isolation method of the heat exchanger, the leak of the outer pipe may be detected by a concentration sensor which is disposed in the inert space and detects the concentration of the gas in the inert space.

  According to such a configuration, it is possible to detect the leak early by detecting the leak using the concentration sensor.

  According to the present invention, the presence of the inactive space between the first circulation portion, which is a space in which the first fluid flows, and the second circulation portion, which is a space in which the second fluid flows, It is possible to prevent the mixing of one fluid with the second fluid.

It is sectional drawing of the heat exchanger of 1st embodiment of this invention. It is sectional drawing of the heat exchanger of 2nd embodiment of this invention. It is sectional drawing of the heat exchanger of 3rd embodiment of this invention. It is sectional drawing of the heat exchanger of 4th embodiment of this invention. It is sectional drawing explaining the leak location isolation method of the heat exchanger of 5th embodiment of this invention. It is a flowchart explaining the leak location isolation method of the heat exchanger of 5th embodiment of this invention. It is sectional drawing explaining the leak location isolation method of the heat exchanger of 6th embodiment of this invention. It is sectional drawing explaining the leak location isolation method of the heat exchanger of 6th embodiment of this invention. It is sectional drawing explaining the leak location isolation method of the heat exchanger of 7th embodiment of this invention. It is sectional drawing of the heat exchanger of 8th embodiment of this invention.

First Embodiment
Hereinafter, the heat exchanger of the first embodiment of the present invention will be described in detail with reference to the drawings.
The heat exchanger of the present embodiment is a multi-tube type heat exchanger called a shell and tube type. The heat exchanger accommodates a plurality of heat transfer tubes inside a casing, and performs heat exchange by flowing fluids of different temperatures to the inside and the outside of the heat transfer tubes.
The heat exchanger of the present embodiment performs heat exchange between the fuel gas and the air used for cooling in the gas turbine to heat the fuel gas and cool the air. However, the application of the heat exchanger is not limited to this.

  As shown in FIG. 1, the heat exchanger 1 includes a casing 2, a plurality of inner pipes 3 disposed in the casing 2 and functioning as a heat transfer pipe, and a plurality of outer pipes 4 accommodating the inner pipe 3 inside. And. A part of the heat transfer tube of the heat exchanger 1 of the present embodiment is a double tube. Although only one inner pipe 3 and two outer pipes 4 are shown in FIG. 1, the heat exchanger 1 of the present embodiment has a plurality of inner pipes 3 and a plurality of outer pipes 4. There is.

  The casing 2 has a dome-shaped (hemispherical-shaped) first dome portion 5, a cylindrical tube portion 7, and a dome-shaped second dome portion 6. The first dome portion 5 is connected to the cylindrical portion 7 so as to seal one end of the cylindrical portion 7, and the second dome portion 6 is connected to the cylindrical portion 7 so as to seal the other end of the cylindrical portion 7 ing.

The first dome portion 5 and the cylindrical portion 7 are separated by a first pipe plate 9, and a fuel gas chamber 12 is formed by the first dome portion 5 and the first pipe plate 9. The fuel gas chamber 12 is partitioned by a partition plate 16 into a first fuel gas chamber 12 a and a second fuel gas chamber 12 b.
The second dome portion 6 and the cylindrical portion 7 are separated by a third pipe plate 11, and a first nitrogen gas chamber 13 is formed by the second dome portion 6 and the third pipe plate 11.

A space formed by the first tube sheet 9, the cylindrical portion 7 and the second tube sheet 10 is partitioned by the second tube sheet 10. The second tube sheet 10 is arranged such that the distance between the first tube sheet 9 and the second tube sheet 10 is smaller than the distance between the second tube sheet 10 and the third tube sheet 11.
A second nitrogen gas chamber 14 is formed by the cylindrical portion 7, the first tube plate 9 and the second tube plate 10.
An air chamber 15 (first circulation portion) into which air A (first fluid) is introduced is formed by the cylindrical portion 7, the second pipe plate 10, the third pipe plate 11, and the plurality of outer pipes 4 There is.

The first dome portion 5 includes a fuel gas supply port 18 for supplying the fuel gas FG (second fluid) to the first fuel gas chamber 12a, and a fuel gas discharge for discharging the fuel gas FG from the second fuel gas chamber 12b. An outlet 19 is formed.
An air supply port 20 (first supply port) for supplying the air A to the air chamber 15 and an air discharge port 21 (first discharge port) for discharging the air A from the air chamber 15 are formed in the cylindrical portion 7. ing. Further, a nitrogen gas discharge port 23 for discharging nitrogen gas NG from the second nitrogen gas chamber 14 is formed in the cylindrical portion 7.
A nitrogen gas supply port 22 for supplying nitrogen gas NG to the first nitrogen gas chamber 13 is formed in the second dome portion 6.

The outer pipe 4 is a pipe that extends in the axial direction D of the cylindrical portion 7 (hereinafter simply referred to as the axial direction D) in the air chamber 15 and connects the first nitrogen gas chamber 13 and the second nitrogen gas chamber 14 It is. One end of the outer pipe 4 is connected to the second pipe sheet 10, and the other end of the outer pipe 4 is connected to the third pipe sheet 11. The first nitrogen gas chamber 13 and the second nitrogen gas chamber 14 communicate with each other through the space inside the outer tube 4.
The inner circumferential surface (first heat transfer surface) of the outer tube 4 functions as a heat transfer surface of the air chamber 15.

  The inner pipe 3 is a U-shaped pipe. One end 3 a of the inner pipe 3 and the other end 3 b of the inner pipe 3 are connected to the first pipe plate 9. In the inner pipe 3, the fuel gas FG in the first fuel gas chamber 12 a flows to the inside of the inner pipe 3 through one end 3 a of the inner pipe 3, and the second fuel gas chamber through the other end 3 b of the inner pipe 3 It is arranged to be discharged to 12b.

The inner pipe 3 includes: a straight first straight portion 25 and a second straight portion 26; and an arc-shaped bend 27 connecting the first straight portion 25 and the second straight portion 26 in the first nitrogen gas chamber 13. Have. The first straight portion 25 and the second straight portion 26 extend so as to be accommodated inside the outer tube 4. Thereby, the outer peripheral surface (second heat transfer surface) of the inner pipe 3 and the inner peripheral surface (first heat transfer surface) of the outer pipe are disposed to face each other.
The bend portion 27 is disposed in the first nitrogen gas chamber 13. The outer pipe 4 accommodates the inner pipe 3 inside and extends in the axial direction D which is the extension direction of the inner pipe 3 so as to pass through the air chamber 15 (the internal space of the casing 2).
In the inner side IS (second flow portion) of the inner pipe 3, air A, which is a second fluid different from the fuel gas FG, flows, and the outer peripheral surface 3s (second heat transfer surface) of the inner pipe 3 transfers heat Act as a face.

The outer diameter of the outer tube 4 can be, for example, 1.1 to 1.2 times the outer diameter of the inner tube 3. The outer diameter of the outer pipe 4 is set such that a predetermined space is formed between the outer peripheral surface of the inner pipe 3 and the inner peripheral surface of the outer pipe 4.
The air chamber 15 is provided with a plurality of baffle plates 28 so that the flow of the air A in the air chamber 15 strikes the outer pipe 4 as equally as possible. The baffle plate 28 also functions as a support member for supporting the outer tube 4.

Next, the operation of the heat exchanger 1 of the present embodiment will be described.
Nitrogen gas NG is supplied to the first nitrogen gas chamber 13 from a nitrogen gas supply device (not shown) via the nitrogen gas supply port 22. The nitrogen gas NG supplied to the first nitrogen gas chamber 13 flows into the space between the outer peripheral surface of the inner pipe 3 and the inner peripheral surface of the outer pipe 4 and is then introduced into the second nitrogen gas chamber 14. The gas is discharged from the gas outlet 23.
Spaces in the first nitrogen gas chamber 13, the second nitrogen gas chamber 14, and the outer peripheral surface of the inner pipe 3 and the inner peripheral surface of the outer pipe 4 are filled with nitrogen gas NG which is an inert gas. It becomes inactive space NA. The first nitrogen gas chamber 13 formed by the second dome portion 6 and the third tube plate 11 is also an inert space.

When the fuel gas FG is supplied to the first fuel gas chamber 12a through the fuel gas supply port 18, the fuel gas FG flows from the one end 3a of the inner pipe 3 into the inner side of the inner pipe 3, and then the other inner end It is introduced into the second fuel gas chamber 12 b from 3 b and discharged from the fuel gas outlet 19.
When air A is supplied to the air chamber 15 via the air supply port 20, the air A collides with the baffle plate 28, flows in the air chamber 15, and then is discharged from the air outlet 21.
During this time, heat exchange is performed between the fuel gas FG and the air A via the nitrogen gas NG, the fuel gas FG is heated, and the air A is cooled.

  According to the above embodiment, the presence of the nitrogen gas space which is the inactive space NA between the space to which the fuel gas FG is supplied and the space to which the air A is supplied allows the fuel gas FG and the air A to be Mixing can be prevented. That is, even in the case where a failure occurs in one of the inner pipe 3 and the outer pipe 4 and the fluid leaks, the fuel gas FG can be obtained by setting the space between the inner pipe 3 and the outer pipe 4 as the inert space NA. It is possible to prevent problems such as the mixing of air and the air A and explosion.

  Moreover, since the bend part 27 is not fixed among the inner pipes 3, it can be set as the structure which does not generate the thermal stress which generate | occur | produces in the inner pipe 3. FIG.

In the above embodiment, the first fluid is the fuel gas FG, and the second fluid is the air A. However, the present invention is not limited thereto. For example, the first fluid may be an oxidant and the second fluid may be an oxidant. It can apply, when applicable to a reducing agent.
In the above embodiment, the space between the inner pipe 3, the inner pipe 3 and the outer pipe 4 is filled with the nitrogen gas NG, but an inert space between the inner pipe 3, the inner pipe 3 and the outer pipe 4 is inactive space For example, the vacuum may be applied between the inner pipe 3, the inner pipe 3 and the outer pipe 4.

Second Embodiment
Hereinafter, a heat exchanger 1B according to a second embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 2, the casing 2 </ b> B of the present embodiment has a third dome portion 30 (dome portion) disposed inside the second dome portion 6.

The third dome portion 30 is formed to form a space S1 with the inside of the second dome portion 6. The third tube sheet 11B of the present embodiment is not connected to the cylindrical portion 7 and the second dome portion 6, but is connected to the third dome portion 30. That is, the third tube sheet 11B of the present embodiment is formed independently of the casing 2B. A first nitrogen gas chamber 13 is formed by the third dome portion 30 and the third tube plate 11. The bend portion 27 of the inner pipe 3 is disposed in the first nitrogen gas chamber 13 formed by the third dome portion 30 and the third pipe plate 11. The third dome portion 30 accommodates the bend portion 27 in cooperation with the third tube sheet 11B.
The first nitrogen gas chamber 13 formed by the third dome portion 30 and the third tube plate 11B is also an inert space (second inert space), and the inert space NA communicates with the first nitrogen gas chamber 13 doing.

  The third dome portion 30 and the cylindrical portion 7 are connected by a bellows 31 (connection portion). That is, the third dome portion 30 is supported by the flexible bellows 31. The bellows 31 is a bellows-like member provided continuously in the circumferential direction of the axis of the cylindrical portion 7.

  According to the above embodiment, since the third tube sheet 11 and the cylindrical portion 7 are not connected, it is possible to reduce the thermal stress generated in the structure such as the third tube sheet 11 by the thermal elongation of the outer tube 4 it can.

Third Embodiment
Hereinafter, a heat exchanger 1C according to a third embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the above-described second embodiment will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 3, the third dome portion 30 and the cylindrical portion 7 of the present embodiment are connected by a plurality of thin plates 32. The thin plate 32 is made of, for example, a metal such as SUS, and is formed continuously in the circumferential direction of the axis of the cylindrical portion 7.
The thin plate 32 is formed in such a thickness as to be flexible. The number of thin plates 32 is set to have a strength capable of supporting the third dome portion 30. The thin plate 32 has a sealing property, and fluidly divides the space S2 (air chamber 15) on one side of the thin plate 32 and the space S3 on the other side of the thin plate 32.

  The nitrogen gas NG is supplied to the space S3 on the other side of the thin plate 32 through the nitrogen gas supply port 22, and the space S3 becomes an inert space NA. That is, the space S3 between the second dome portion 6 and the third dome portion 30 can be made an inert space NA by the plurality of thin plates 32.

  According to the above embodiment, both the space S4 formed by the third tube sheet 11 and the third dome portion 30 and the space S3 between the second dome portion 6 and the third dome portion 30 are inactive spaces. By setting it as NA, the pressure difference between these spaces can be made small.

Fourth Embodiment
Hereinafter, a heat exchanger 1C according to a third embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the above-described second embodiment will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 4, the outer tube 4C of this embodiment connects one straight portion 4a and the other straight portion 4a, and an outer tube bend portion that accommodates the bend portion 27 of the inner tube 3 inside. It has a U-shape with 33. That is, the heat transfer tube of the present embodiment, including the bend portions 27 and 33, is a double tube over the entire length.

The materials of the inner pipe 3, the outer pipe 4C, and the baffle plate 28 in the present embodiment are the same. The material of the inner pipe 3, the outer pipe 4 </ b> C, and the baffle plate 28 may be, for example, inconel.
Further, the nitrogen gas supply port 22C of the present embodiment is provided at a position corresponding to the second nitrogen gas chamber 14 of the casing 2.

  According to the above embodiment, the possibility of the fuel gas FG and the air A mixing can be further reduced.

Fifth Embodiment
Hereinafter, the leak point isolation method of the heat exchanger of 5th embodiment of this invention is demonstrated in detail with reference to drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and the description of the same parts will be omitted.
The leak point isolation method of the heat exchanger of the present embodiment is characterized in that, when a gas leak occurs, the seal device 35 is used to isolate the site where the gas leak has occurred.

  As shown in FIG. 5, the sealing device 35 includes a cap member 36 (sealing member) and a high pressure water supply device 37 for supplying high pressure water to the cap member 36. The cap member 36 is a hollow cylindrical member made of a flexible material that can withstand the water pressure of high-pressure water, such as stainless steel, copper or the like.

The cap member 36 has a cylindrical enlarged diameter portion 38 and a sealing portion 39 which seals one end and the other end of the enlarged diameter portion 38. In one sealing portion 39, a through hole 40 for introducing high pressure water is formed. The outer diameter of the enlarged diameter portion 38 is slightly smaller than the inner diameter of the outer tube 4.
The high pressure water supply device 37 is a device for filling the cap member 36 with high pressure water (for example, 100 MPa to 300 MPa) through the hose 41.

  As shown in FIG. 6, in the method for separating leak locations in a heat exchanger according to the present embodiment, a leak determination step S1, an inflowing gas sealing step S2, an inner pipe removing step S3 for pulling out the inner pipe 3, and a cap member arrangement It has process S4 (sealing member arrangement process) and cap member expansion process S5 (sealing member expansion process).

The leak determination step S1 is a step of determining whether or not a leak has occurred using a concentration sensor CS (see FIG. 1) such as a gas detector. The concentration sensor CS is disposed in the inert space NA and is a sensor that detects the concentration of the nitrogen gas NG. If a gas leak occurs, the concentration of the inert space NA changes.
In the leak determination step S1, when the concentration sensor CS detects a change in the concentration of nitrogen gas NG in the inert space NA, it is determined that a leak has occurred. If it is determined in the leak determination step S1 that a leak has occurred (YES), the operator carries out the inflowing gas sealing step S2.
In the inflow gas sealing step S2, the operator stops the flow of the fluid flowing into the inner pipe 3 corresponding to the outer pipe 4 in which the leak has occurred using a predetermined caulking material or the like.

  In the inner pipe removing step S3, the operator cuts the inner pipe 3 and pulls out the inner pipe 3. Thereby, as shown in FIG. 5, the inner pipe 3 is removed from the inside of the outer pipe 4.

  In the cap member disposing step S4, the operator disposes the cap member 36 of the sealing device 35 inside the outer tube 4. At this time, the position of the cap member 36 is the same as the baffle plate 28 before and after the leak point L in the axial direction D. Specifically, the cap member 36 is disposed at the position of the baffle plate 28 adjacent to one side in the axial direction D of the leak point L and the position of the baffle plate 28 adjacent to the other side in the axial direction of the leak point L.

  In the cap member expansion step S5, the operator operates the high pressure water supply device 37 to supply high pressure water to the inside of the cap member 36. As a result, the diameter-increased portion 38 of the cap member 36 is expanded in diameter and closely attached to the inner circumferential surface of the outer tube 4. Thereby, the leak point L can be isolated.

According to the above-mentioned embodiment, even when the leak occurs in the outer pipe 4 of the heat transfer pipe having the length, the leak portion can be isolated in a limited manner.
Moreover, by using the cap member 36 specialized for the outer pipe 4, the workability can be improved.
Further, by detecting the leak using the concentration sensor CS, it is possible to detect the leak early.

Sixth Embodiment
Hereinafter, the leak point isolation method of the heat exchanger of the sixth embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the above-described fifth embodiment will be mainly described, and the description of the same parts will be omitted.

As shown in FIG. 7, the sealing device 35 </ b> B of the present embodiment restrains expansion of the tube portion 43, the high pressure water supply device 37 for supplying high pressure water to the tube portion 43, and the axial direction D of the tube portion 43. And a restraint portion 44.
The tube portion 43 is a hollow cylindrical member made of, for example, nylon, urethane rubber, soft vinyl chloride, nitrile rubber or fluoro rubber. The outer diameter of the tube portion 43 is slightly smaller than the inner diameter of the inner pipe 3.

  Moreover, the position corresponding to the baffle plate 28 of the inner tube 3 of the present embodiment is formed of an extensible material.

  The leak point isolation method of the heat exchanger 1 of the present embodiment is different from the leak point isolation method of the heat exchanger of the fifth embodiment in that the inflow gas sealing step S2 and the inner pipe drawing step S3 are included. It is characterized in that the leak point is isolated without pulling out the inner pipe 3.

  As shown in FIG. 7, after the tube portion 43 of the sealing device 35B is inserted into the inner pipe 3, the high pressure water supply device 37 is operated. By supplying high pressure water to the inside of the tube portion 43, as shown in FIG. 8, the tube portion 43 is expanded to expand the diameter of the inner pipe 3 from the inside. By expanding the diameter of the inner pipe 3 until the outer peripheral surface of the inner pipe 3 and the inner peripheral surface of the outer pipe 4 are in contact with each other, it is possible to isolate the leak location.

According to the said embodiment, a leak location can be isolated, without pulling out the inner pipe | tube 3. As shown in FIG.
The structure of the sealing device 35B is not limited to the above-described structure. For example, the inner pipe 3 may be expanded in diameter by expanding a viscous substance using a rod-shaped explosive.

Seventh Embodiment
Hereinafter, the leak point isolation method of the heat exchanger of the seventh embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the above-described sixth embodiment will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 9, the heat exchanger 1 of the present embodiment has an O-ring 45 fitted on the outer peripheral surface of the inner pipe 3 at a position corresponding to the baffle plate 28. The O-ring 45 is, for example, an annular member formed of synthetic rubber. The O-ring 45 may be adhered to the inner circumferential surface of the outer tube 4.
By providing the O-ring 45, the O-ring 45 intervenes between the outer peripheral surface of the inner pipe 3 and the inner peripheral surface of the outer pipe 4 when the diameter of the inner pipe 3 is expanded.

  According to the said embodiment, when the inner pipe | tube 3 and the outer pipe | tube 4 contact directly, it can prevent that these are worn. In addition, the O-ring 45 can make sealing more reliable.

Eighth Embodiment
Hereinafter, a heat exchanger according to an eighth embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 10, the heat exchanger 1D of the present embodiment is a plate type heat exchanger. Heat exchanger 1D of this embodiment has casing 50, fuel gas distribution part 55 which fuel gas FG distributes, and air distribution part 56 which air A distributes. The fuel gas flow portion 55 and the air flow portion 56 are portions divided in the casing 2 by the plurality of plates 51, 52, 53 and 54.

  The fuel gas flow portion 55 is formed by the first plate 51 and the second plate 52 opposed to the first plate 51. The fuel gas FG is supplied to the fuel gas distribution unit 55 through the fuel gas supply port 18D, and the fuel gas FG is discharged through the fuel gas discharge port 19D.

  The air flow portion 56 is formed by the third plate 53 and the fourth plate 54 facing the third plate 53. The air A is supplied to the air circulation unit 56 through the air supply port 20D, and the air A is discharged through the air discharge port 21D.

  Each plate 51, 52, 53, 54 is shaped to absorb the thermal expansion difference. The plates 51, 52, 53, 54 of the present embodiment have a wave shape. More specifically, the plates 51, 52, 53, 54 have a sinusoidal shape. The shape of the plates 51, 52, 53 and 54 may be any shape as long as it can absorb the thermal expansion difference, and may be, for example, a rectangular wave shape.

  The second plate 52 of the fuel gas flow portion 55 and the third plate 53 of the air flow portion 56 are disposed to face each other. That is, the second plate 52 and the third plate 53 are not common plates, and the second plate 52 and the third plate 53 are disposed at an interval.

  Nitrogen gas NG is supplied between the third plate 53 of the second plate 52 and the nitrogen gas supply port 22D. That is, the space between the second plate 52 and the third plate 53 is an inert space NA. Further, nitrogen gas NG is discharged from between the second plate 52 and the third plate 53 through the nitrogen gas discharge port 23D.

According to the above embodiment, the presence of the nitrogen gas space which is the inactive space NA between the space to which the fuel gas FG is supplied and the space to which the air A is supplied allows the fuel gas FG and the air A to be Mixing can be prevented. That is, even when the plate 51, 52, 53, 54 has a defect and the fluid leaks, the space between the fuel gas passage 55 and the air passage 56 is the inactive space NA, so that the fuel It is possible to prevent such a problem that the gas FG and the air A mix and explode.
Moreover, by making the plates 51, 52, 53, 54 into a corrugated shape, not only heat transfer is promoted, but also thermal elongation difference can be absorbed.

The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within the scope of the present invention are also included. .
For example, in the heat exchanger of the fourth embodiment, the materials of the inner pipe, the outer pipe, and the baffle plate are the same, but in the heat exchangers of the other embodiments, the materials of the inner pipe, the outer pipe, and the baffle plate May be the same.

1, 1 B, 1 C, 1 D heat exchanger 2, 2 B casing 3 inner pipe 3 s outer peripheral surface of inner pipe 4 outer pipe 4 s inner peripheral surface of outer pipe (first heat transfer surface)
5 first dome portion 6 second dome portion 7 cylindrical portion 9 first pipe plate 10 second pipe plate 11, 11 B third pipe plate 12 fuel gas chamber 12a first fuel gas chamber 12b second fuel gas chamber 13 first nitrogen Gas room 14 Second nitrogen gas room 15 Air room (1st circulation department)
DESCRIPTION OF SYMBOLS 16 Partition plate 18 Fuel gas supply port 19 Fuel gas discharge port 20 Air supply port 21 Air discharge port 22 Nitrogen gas supply port 23 Nitrogen gas discharge port 25 1st straight part 26 2nd straight part 27 Bend part 28 Baffle plate 30 3rd dome Department (dome part)
31 Bellows (Connection)
32 sheet 33 outer tube bend portion 35 sealing device 36 cap member 37 high pressure water supply device 38 enlarged diameter portion 39 sealing portion 40 through hole 41 hose 43 tube portion 44 restraint portion 45 O ring 50 casing 51 first plate 52 second Plate 53 Third plate 54 Fourth plate 55 Fuel gas circulation unit 56 Air circulation unit A Air (first fluid)
CS concentration sensor FG fuel gas (second fluid)
Inner side of IS inner tube NA inert space NG nitrogen gas

Claims (9)

A first flow portion having a first heat transfer surface and in which a first fluid flows;
A second heat transfer surface opposite to the first heat transfer surface, an inert space between the first heat transfer surface and the second heat transfer surface, and a second fluid different from the first fluid flowing And a heat exchanger. A cylindrical casing having a first supply port to which the first fluid is supplied, and a first discharge port to which the first fluid is discharged;
An inner pipe extending so as to pass through the inner space of the casing and in which the second fluid flows inside;
The inner pipe is accommodated inside and extends in the extension direction of the inner pipe so as to pass through the inner space, and the outer pipe is made an inert space between the inner pipe and the inner pipe,
The first heat transfer surface is an inner circumferential surface of the outer pipe,
The heat exchanger according to claim 1, wherein the second heat transfer surface is an outer peripheral surface of the inner pipe. A first tube sheet to which one end of the outer tube is connected;
A third tube sheet connected to the other end of the outer tube and formed independently from the casing;
The inner tube includes a first straight portion housed inside the one outer tube, a second straight portion housed inside the other outer tube, the first straight portion, and the second straight portion. Forming a U-shape having bends to be connected,
And a dome portion which accommodates the bend portion in cooperation with the third tube sheet and which forms a second inert space communicating with the inert space;
The heat exchanger according to claim 2, wherein the third tube sheet, the dome portion, and the casing are connected by a flexible connection portion.   The heat exchanger according to claim 3, wherein the connection portion has a sealing property, and a space between the dome portion and the casing is an inert space. A first tube sheet to which one end of the outer tube is connected;
The inner tube includes a first straight portion housed inside the one outer tube, a second straight portion housed inside the other outer tube, the first straight portion, and the second straight portion. Forming a U-shape having bends to be connected,
The heat exchange according to claim 2, wherein the outer pipe has a U-shape having an outer pipe bend portion for connecting the one outer pipe and the other outer pipe and accommodating the bend portion inside. vessel.   The heat exchanger according to any one of claims 3 to 5, wherein the first tube sheet, the inner pipe, and the outer pipe are formed of the same material. The heat exchanger leak point isolation method according to any one of claims 2 to 6,
An inner pipe removing step of drawing out an inner pipe disposed inside the outer pipe when a leak occurs in the outer pipe;
A sealing member disposing step of arranging a sealing member which is formed of a flexible material and expands by being filled with a fluid before and after the leak point of the outer tube in the extension direction of the outer tube ,
And a sealing member expansion step of expanding the sealing member. The heat exchanger leak point isolation method according to any one of claims 2 to 6,
When a leak occurs in the outer tube, the inner tube is formed of a flexible material before and after the leak point of the outer tube in the extension direction of the outer tube, A sealing member arranging step of arranging a sealing member that expands by being filled with a fluid;
And a sealing member expansion step of expanding the sealing member.   The leak point isolation | separation method of the heat exchanger of Claim 7 or 8 which arrange | positions the leak of the said outer tube | pipe by the concentration sensor which arrange | positions in the said inert space and detects the density | concentration of the gas of the said inert space.

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