JP2001200729A - Installation structure for exterior plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior plate installing structure, capable of increasing a reliability and workability by surely preventing exterior plates from being displaced or fallen down caused by an external force, such as thermal elongation difference due to internal hot fluid and strong wind. SOLUTION: In an installation structure for a plurality of exterior plates 25 for covering the external peripheral surface of a stack 21 allowing hot gas to be flown therethrough, a plurality of flat plate rings 24 are installed on the external peripheral surface of the stack 21, the overlapped part of the exterior plats 25 adjacent to each other is disposed on the flat plate rings 24, and a band 31 having a fixing part 31a and a spring part 31b is disposed on the flat plate rings 24. Then, the overlapped part of the exterior plates 25 is fixed movably with respect to the flat plate rings 24, by connecting rivets 28 to the fixing parts 31a of the band 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a stack (chimney) of a gas turbine in a combined cycle system.
Also, the present invention relates to a mounting structure of an exterior plate that covers an exhaust duct and the like.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 8, an exhaust gas duct of a gas turbine in a combined cycle system has a cylindrical gas turbine exhaust port connection portion 1, a cylindrical first expansion joint 2, and a truncated cone-shaped expansion portion. 3, cylindrical second expansion joint 4,
A cylindrical rectangular switching joint 5, a rectangular third expansion joint 6, an exhaust gas damper 7 serving as a gas valve, a rectangular pipe 8, a rectangular fourth expansion joint 9, a rectangular enlarged pipe 10, a silencer 11, a rectangular cylindrical switching joint 12, and It is configured by joining the stacks 21 to each other.

[0003] As shown by the arrows, the exhaust gas discharged from the gas turbine flows from the gas turbine exhaust port connection portion 1 through the first expansion joint 2 to the expansion section 3 to reduce the flow velocity. Next, the exhaust gas is
After passing through the expansion joint 4, it flows into the exhaust gas damper 7 from the third expansion joint 6 switched to the rectangular pipe by the cylindrical rectangular switching joint 5.
When the exhaust gas goes straight, it is guided to an exhaust gas boiler (not shown) through the rectangular tube 8. The thermal energy of the exhaust gas generates steam in the exhaust gas boiler, and the steam is used to operate the steam turbine generator.In normal operation, the exhaust gas flows into the exhaust gas boiler. May have to be released directly to the atmosphere without inflow. At that time, damper 7
, The flow direction of the exhaust gas is switched from the exhaust gas boiler to the stack 21 made of a steel plate having a cylindrical structure. The exhaust gas whose flow has been turned upward by the damper 7 passes through the stack 21 via the fourth expansion joint 9, the rectangular expansion pipe 10, the silencer 11, and the rectangular cylindrical switching joint 12, and is discharged to the atmosphere.

[0004] Generally, except for the stack 21, the outside of the duct is covered with a heat insulating material, and further, an exterior plate is provided around the outside. As shown in FIGS. 9 to 12, the stack 21 is installed at a height of 20 m or more above the ground. Normally, it is inaccessible to humans, and there is no need to consider heat dissipation. , A plurality of exterior plates 25
It is structured to be surrounded only by. The adjacent exterior plate 25
The ends are arranged in two or three layers and overlap each other.
Is fixed by connecting with rivets 28. For this reason, the flat plate ring 24 welds the base end of the stud bolt 22 to the outer surface of the stack 21 and bolts the clip 23 to the tip of the stud bolt 22,
A ring material 24a is welded between the clips 23 to form an annular shape, and is provided at a certain interval in the vertical direction over several stages.

Further, the exhaust gas temperature of the gas turbine is at most 6
The temperature of the stack 21 is about 400 ° C., and the temperature of the outer plate 25 is about 100 ° C. This is because the cooling air passage is provided between the stack 21 and the exterior plate 25, the upper and lower portions of the exterior plate 25 are open to the atmosphere, and cool air flows due to a natural circulation effect. As a result, since there is a temperature difference of about 300 ° C. between the stack 21 and the outer plate 25 during operation, several tens mm
Is generated. As a countermeasure, a long hole 25a extending in the differential extension direction is formed at the end of the exterior plate 25 as shown in FIGS. 24 is fixed with rivets 28 so that the exterior plate 25
4 can be moved.

[0006]

However, in the above-mentioned conventional mounting structure, the washer 27 and the flat plate ring 24 are not provided.
Is fixed to the flat plate ring 24 by rivets 28 so that the axial expansion difference of the exhaust gas duct caused by the temperature difference can be absorbed only in a small range, and the external force such as strong wind As a result, there is a possibility that the position of the exterior plate 25 is shifted or the outer plate 25 is detached from the flat plate ring 24 and falls off the stack 21. As a countermeasure, in the conventional mounting structure, the stainless steel band 31 with the spring 32 is wrapped around the outer peripheral surface of the outer plate 25 to prevent falling off, but this is not a permanent measure and lacks reliability. However, it was difficult to completely eliminate the falling-off accident of the exterior plate 25. The cause of such an accident is that the overlap of the corrugated sheet and the corrugated sheet forming the exterior plate 25 is a complicated shape, so that the exterior plate 25 does not slip as originally planned, and is caused by a difference in elongation in a portion that is difficult to slip. It is considered that the stress is concentrated, the corrugated sheet is deformed, and the fixing portion of the rivet 28 is released. On the other hand, since the work of winding the band 31 around the outer peripheral surface of the exterior plate 25 is complicated, if it is performed separately from the work of joining the rivets 28, much work time is required, and it has been difficult to enhance the work efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to surely prevent displacement and falling off of an exterior plate caused by a difference in thermal expansion due to an internal high-temperature fluid or an external force such as a strong wind. Another object of the present invention is to provide a mounting structure of an exterior plate capable of improving reliability and workability.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention relates to a mounting structure of an exterior plate for covering an outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets. A plurality of plate rings are attached to the outer peripheral surface of the band, a superimposed portion of the adjacent outer plate is arranged on the plate ring, and a band having a fixed portion and a spring portion is arranged, and a stopper is attached to the band fixed portion. Is locked so that the overlapping portion of the exterior plate is movable to the flat plate ring.

Further, according to the present invention, there is provided a mounting structure of an exterior plate for covering an outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets.
By attaching a plurality of flat rings to the outer peripheral surface of the cylindrical body via a plurality of elastic members and fixing the outer plate to the flat ring, the outer plate can be moved relative to the cylindrical body. Installed.

According to the present invention, in a mounting structure of an exterior plate for covering an outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets, one end of a spring bolt is fixed to the outer peripheral surface of the cylindrical body, and By fixing the other end of the bolt to the center position of each of the outer plates, the outer plate is movably attached to the tubular body.

Further, according to the present invention, there is provided a mounting structure of an exterior plate for covering an outer peripheral surface of a cylindrical body through which a high temperature fluid flows with a plurality of sheets.
On the outer peripheral surface of the tubular body, the expandable ends of a plurality of support plates having an intermediate portion curved outward are attached, and the outer plate is fixed to the intermediate portion of the support plate, thereby forming the outer plate. It is movably attached to the cylindrical body.

Further, according to the present invention, in a mounting structure of an exterior plate for covering the outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets, a plurality of flat rings are mounted on the outer peripheral surface of the cylindrical body.
Between the upper and lower sides of the flat plate ring, the overlapping portion of the adjacent outer plates is arranged, and the end of each of the outer plates avoiding the overlapping portion is movably fixed to the flat plate ring with a stopper. I have.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. Here, FIG. 1 is a perspective view of a mounting structure of an exterior plate according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a fixing portion of the exterior plate. The same members as those of the conventional example are denoted by the same reference numerals, and the description thereof will be simplified.

As shown in FIG. 1, a stack 21 according to a first embodiment of the present invention constitutes a part of an exhaust gas duct of a gas turbine similarly to a conventional example, and has a high temperature from a gas turbine therein. It is formed in a cylindrical body through which gas (exhaust gas at 600 ° C.) flows. In addition, the outer peripheral surface of the stack 21 is covered by arranging a plurality of outer plates 25 so as to surround the stack 21, and the outer appearance of the stack 21 is improved by the outer plates 25. These exterior plates 25
Is formed by bending a stainless steel plate to form a corrugated sheet (corrugated sheet) in which irregularities having a substantially U-shaped cross section extending in the axial direction (vertical direction) of the stack 21 are alternately located along the circumferential direction. Therefore, the outer plate 25
Has a structure in which a difference in elongation due to a temperature difference with the stack 21 can be absorbed to some extent.

The exterior plate 25 is disposed on the outer peripheral surface of the stack 21 over the entire surface in the axial direction and the peripheral direction.
It is adjusted to be stacked or triple stacked. The overlapping portions of these exterior plates 25 are respectively arranged corresponding to the arrangement positions of the plurality of steel plate rings 24,
It is fixed on the flat plate ring 24 by being connected with a rivet 28 together with a band 31 described later. In addition,
As shown in FIG. 2, an elongated hole 25a similar to the conventional example is formed at the end of each of the outer plates 25, and a band 31 and a flat plate ring 24, which will be described later, are fixed with rivets 28 while adjusting the interval with a spacer 26. By doing so, the exterior plate 25 and the band 3
1 is configured to move on the flat plate ring 24.

The flat plate ring 24 is mounted on the outer peripheral surface of the stack 21 in a floating state, and forms a cooling air passage through which air flows between the stack 21 and the exterior plate 25. For this reason, a plurality of radially protruding stud bolts 22 are arranged on the outer peripheral surface of the stack 21 at intervals in the circumferential direction.
A clip 23 having a substantially U-shaped cross section and having a bent upper end piece 23 a is bolted to the tip of the “” by using a nut 29. Therefore, the flat plate ring 24 is
A belt-like ring material 24a is fixed to the upper bent portion 23a by welding to form an annular shape.
1 are provided over several stages at regular intervals in the vertical direction.

On the other hand, the stainless steel band 31 is formed in an annular shape along the circumferential direction of the outer peripheral surface of the outer plate 25 and is wound around the outer plate 25 to prevent the outer plate 25 from falling off.
The band 31 is arranged corresponding to the arrangement position of the flat plate ring 24, and has a fixing portion 31a corresponding to a washer.
And a spring portion 31b for providing elasticity. As shown in FIG. 2, the fixing portion 31 a is formed to have a concave shape corresponding to the overlapping portion of the adjacent exterior plate 25, and a through hole 30 through which the rivet 28 is inserted is formed in the center thereof. Further, the spring portion 31 b is
In order to allow the band 31 to move with the movement of the band 31, the band 31 is provided at an intermediate portion of the band 31 and extends along the circumferential direction of the stack 21.

In order to mount the required number of outer plates 25 on the outer peripheral surface of the stack 21 by the mounting structure of the present embodiment, first, the required number of plate rings 24 are attached to the outer periphery of the stack 21 by using stud bolts 22, clips 23 and the like. Attach in place on the surface. Next, while arranging the outer plates 25 on the outer peripheral surface of the stack 21, the overlapping portions of the adjacent outer plates 25 are arranged on the flat plate ring 24, and
1 is placed on the flat plate ring 24 and wound. afterwards,
When the fixing portion 31a of the band 31 and the flat plate ring 24 are fixed with the rivets 28 with the spacer 26 interposed therebetween,
The overlapping portion of the exterior plate 25 is movably attached to the flat plate ring 24 (see FIGS. 1 and 2).

In the mounting structure according to the first embodiment of the present invention, the band 31 having the fixing portion 31a and the spring portion 31b is used, and the overlapping portion of the adjacent outer plate 25 is flat-plated with the rivet 28 together with the band 31. 24, the parts corresponding to washers are not required, and the work of joining the rivets 28 and the work of winding the band 31 can be performed simultaneously, so that the construction time can be reduced and the cost can be reduced. .

FIG. 3 is a cross-sectional view of a mounting structure for an exterior plate according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line AA of FIG. The mounting structure of the exterior plate according to the second embodiment is the first
The difference from the mounting structure of the embodiment is that, as shown in FIGS. 3 and 4, a plurality of flat rings 24 are arranged in a state of floating on the outer peripheral surface of the stack 21 via a plurality of elastic members 41 which are spring members. That is, the outer plate 25 is movably attached to the stack 21 by fixing the outer plate 25 to the flat plate ring 24.
That is, in the mounting structure of the present embodiment, the flat plate ring 24 is supported by the stack 21 by the elastic member 41, and can be moved in the axial direction of the stack 21 by bending of the elastic member 41. The circumferential expansion difference between the plates 25 can also be absorbed.

The expansion and contraction member 41 may be a leaf spring or a bar spring, and may be made of a normal steel material, and the bending may be within the elastic stress of the material with respect to the maximum elongation difference. For this reason, both ends of the elastic member 41 are
And can be attached to the flat plate ring 24 by welding. In addition, the elastic member 41 is formed by folding a leaf spring material to form a waveform having a substantially Z-shaped cross section, and the elasticity is maintained. The elastic member 41 may have a shape in which a bar spring is wound in a coil shape. Other configurations are the same as those of the first embodiment.

In the mounting structure according to the second embodiment of the present invention, the flat plate ring 24 is mounted on the outer peripheral surface of the stack 21 via a plurality of elastic members 41, and the outer plate 25 is fixed to the flat plate ring 24. Since the outer plate 25 is movably attached to the stack 21, there is no need to provide a sliding mechanism on the flat plate ring 24, and the outer plate 25 can be securely fixed with the rivets 28 and the rigidity of the outer plate 25 is improved. It is possible to improve the reliability by eliminating an accident such as the falling off of the exterior plate 25.
In addition, since both ends of the elastic member 41 can be attached to the stack 21 and the flat plate ring 24 by welding, the on-site work can be simplified. Further, since it is not necessary to form a long hole which requires a large number of steps at the end of the exterior panel 25, the number of steps for attaching the exterior panel 25 can be greatly reduced. Further, in the installation of the flat plate ring 24, since a long material can be used instead of the conventional short flat steel, the number of welding steps can be significantly reduced.

FIG. 5 is a conceptual view of a structure for mounting an exterior plate according to a third embodiment of the present invention. The mounting structure of the armor plate according to the third embodiment is different from the mounting structure of the first embodiment, as shown in FIG. To be movably mounted on the vehicle. That is, in the mounting structure of the present embodiment, the outer plate 25 is directly supported by the stack 21 in a state of being floated by the spring bolt 42 without using the flat ring 24, and the shaft of the stack 21 is bent by the spring bolt 42. It can move in the direction and the circumferential direction. For this reason, the spring bolt 42 is configured by connecting a proximal shaft portion 43a and a distal screw shaft portion 43b with a coil spring 44, and the proximal shaft portion 43a is stacked by welding. The distal end side screw shaft portion 43b is fixed to the center position of each exterior plate 25 by bolting.

In the mounting structure according to the third embodiment of the present invention, spring bolts 42 are erected on the outer peripheral surface of the stack 21 so that each outer plate 25 can be moved to the outer peripheral surface of the stack 21 via the spring bolt 42. Because of the mounting, it is not necessary to provide a flat plate ring or a sliding mechanism for mounting the outer plate 25, and the outer plate 25 is
1, and a fixed band is not required. Therefore, according to the mounting structure of the present embodiment,
The number of man-hours for processing the exterior plate 25 and the number of man-hours for on-site work are reduced, and cost reduction and workability can be improved.

FIG. 6 is a sectional view of a mounting structure for an exterior plate according to a fourth embodiment of the present invention. The mounting structure of the exterior plate according to the fourth embodiment is different from the mounting structure of the first embodiment, as shown in FIG. 6, in which a plurality of exterior plates 25 are connected to a stack 21 via a plurality of support plates 45. That is, it is movably mounted on the outer peripheral surface. That is, in the mounting structure of the present embodiment, the support plate 45 in which the flat plate ring 24, the stud bolt 22, the clip 23, and the like are integrated is used, and the exterior plate 25 is supported by the stack 21 in a state of being floated by the support plate 45. The stack 21 can be moved in the axial direction and the circumferential direction by bending of the support plate 45. For this reason, the support plate 45 has an intermediate portion 45a that is curved outward, and both end portions 45b that are elastically bent.
The brackets 46 at both ends 45b are fixed to the outer peripheral surface of the stack 21 by welding. And each exterior plate 25 is a support plate 4
5 is riveted to the intermediate portion 45a. Other configurations are the same as those of the first embodiment.

In the mounting structure according to the fourth embodiment of the present invention, a support plate 45 is provided on the outer peripheral surface of the stack 21 so that each outer plate 25 can be moved to the outer peripheral surface of the stack 21 via the support plate 42. Because of the attachment, substantially the same effects as in the third embodiment can be obtained.

FIG. 7 is a conceptual diagram of a structure for mounting an exterior plate according to a fifth embodiment of the present invention. The mounting structure of the armor plate according to the fifth embodiment is different from the mounting structure of the first embodiment in that, as shown in FIG. Ring 24
Exterior plate 2 that is disposed between the upper and lower sides of the
5 is movably attached to the flat plate ring 24 with a stopper such as a stud bolt 22. That is, in the mounting structure of the present embodiment, the fixing portion of the exterior plate 25 is divided into two points to facilitate sliding of the exterior plate 25. Other configurations are the same as those of the first embodiment. In the mounting structure according to the fifth embodiment of the present invention, the fixing portions of the adjacent exterior plates 25 are installed at two points with the overlapping portion interposed therebetween, so that an external force such as a thermal expansion difference or a strong wind acts. In addition, the outer plate 25 can be largely moved without detaching from the flat plate ring 24, and the reliability can be improved.

The embodiments of the present invention have been described above.
The present invention is not limited to the embodiments described above, and various modifications and changes can be made without departing from the spirit of the present invention. For example, the exterior plate 25 according to the present embodiment may be a flat-surfaced plate instead of a corrugated one depending on the use mode.

[0029]

As described above, the outer plate mounting structure according to the present invention covers the outer peripheral surface of the cylindrical body through which the high-temperature fluid flows with a plurality of sheets, and the outer peripheral surface of the cylindrical body has a plurality of flat plates. By attaching a ring, arranging a superposed portion of the adjacent outer plate on the flat plate ring, arranging a band having a fixing portion and a spring portion, and locking a stopper to the fixing portion of the band. Since the overlapping portion of the exterior plate is movably fixed to the flat plate ring, the number of parts and the number of work steps can be reduced, the construction time can be shortened, the work efficiency can be improved, and the cost can be reduced.

Further, the mounting structure of the armor plate according to the present invention comprises:
The outer peripheral surface of the cylindrical body through which the high-temperature fluid flows is covered with a plurality of sheets, a plurality of flat plate rings are attached to the outer circumferential surface of the cylindrical body via a plurality of elastic members, and the outer plate is attached to the flat plate ring. By fixing, the outer plate is movably attached to the tubular body, so that the outer plate is reliably prevented from being displaced or dropped due to a difference in thermal expansion due to an internal high-temperature fluid or an external force such as a strong wind. And reliability and workability can be improved.

Further, in the mounting structure of the armor plate according to the present invention, the outer peripheral surface of the cylindrical body through which the high-temperature fluid flows is covered by a plurality of sheets, and one end of a spring bolt is fixed to the outer peripheral surface of the cylindrical body. In addition, since the other end of the spring bolt is fixed to the center position of each of the outer plates, the outer plate is movably attached to the tubular body.
The same effect as the above invention can be obtained, and the number of on-site work steps can be reduced.

Further, the mounting structure of the armor plate according to the present invention comprises:
The outer peripheral surface of the cylindrical body through which the high-temperature fluid flows is covered with a plurality of sheets. At the outer peripheral surface of the cylindrical body, extendable both end portions of a plurality of support plates whose intermediate portions are curved outward are attached. By fixing the exterior plate to an intermediate portion of the support plate, the exterior plate is movably attached to the tubular body.
The same effect as the above invention can be obtained.

The mounting structure of the armor plate according to the present invention covers the outer peripheral surface of the cylindrical body through which the high-temperature fluid flows with a plurality of sheets.
A plurality of flat rings are attached to the outer peripheral surface of the cylindrical body, and a superposed portion of the adjacent outer plates is disposed between upper and lower portions of the flat ring, and an end of each of the outer plates avoiding the superposed portion. Since the portion is movably fixed to the flat plate ring with a stopper, the same effect as the above invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of an exterior plate attached by an attachment structure according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a fixing portion of the exterior plate.

FIG. 3 is a cross-sectional view showing a part of an exterior plate attached by an attachment structure according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA in FIG.

FIG. 5 is a conceptual diagram showing a part of an exterior plate attached by an attachment structure according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a mounting structure of an exterior plate according to a fourth embodiment of the present invention, showing a support plate to which the exterior plate is attached.

FIG. 7 is a conceptual diagram showing a part of an exterior plate attached by an attachment structure according to a fifth embodiment of the present invention.

FIG. 8 is a conceptual perspective view showing a configuration of a conventional gas turbine exhaust gas duct.

FIG. 9 is a perspective view showing a part of an exterior plate attached by a conventional attachment structure.

FIG. 10 is a perspective view showing an arrangement of the exterior plates.

FIG. 11 is a cross-sectional view showing a conventional ring structure for mounting an exterior plate, showing a flat plate ring to which the exterior plate is attached.

FIG. 12 is a cross-sectional view showing a fixing portion of a conventional exterior plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Stack (cylindrical body) 22 Stud bolt 23 Clip 24 Plate ring 25 Outer plate 28 Rivets 31 Band 31a Fixed part 31b Spring part 41 Expandable member 42 Spring bolt 45 Support plate

Claims (7)

[Claims] 1. A mounting structure for an exterior plate that covers an outer peripheral surface of a cylindrical body through which a high-temperature fluid flows by a plurality of sheets, wherein a plurality of flat plate rings are mounted on the outer circumferential surface of the cylindrical body, and the flat plate ring is adjacent to the flat plate ring. Move the overlapping portion of the exterior plate to the flat plate ring by arranging the overlapping portion of the exterior plate, arranging a band having a fixing portion and a spring portion, and locking a stopper to the fixing portion of the band. A mounting structure for an exterior plate, which is fixed as possible. 2. The exterior plate according to claim 1, wherein the exterior plate is formed in a waveform in which irregularities extending in an axial direction of the cylindrical body are alternately located along a circumferential direction. Mounting structure. 3. A mounting structure for an exterior plate that covers an outer peripheral surface of a tubular body through which a high-temperature fluid flows with a plurality of sheets, wherein a plurality of flat rings are attached to the outer peripheral surface of the tubular body via a plurality of elastic members. A mounting structure for an exterior plate, wherein the exterior plate is fixed to the flat plate ring so that the exterior plate is movably attached to the tubular body. 4. The elastic member according to claim 3, wherein the elastic member is formed in a folded wave shape or a coil shape.
The mounting structure of the armor plate described in 1. 5. A mounting structure of an exterior plate for covering a plurality of outer peripheral surfaces of a cylindrical body through which a high-temperature fluid flows, wherein one end of a spring bolt is fixed to the outer peripheral surface of the cylindrical body and the other end of the spring bolt is provided. Wherein the outer plate is fixed to a center position of each of the outer plates, so that the outer plate is movably mounted on the tubular body. 6. An outer panel mounting structure for covering the outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets, wherein a plurality of support plates having intermediate portions curved outwardly extend and contract on the outer peripheral surface of the cylindrical body. A mounting structure for an exterior plate, wherein the exterior plate is movably attached to the tubular body by attaching possible end portions and fixing the exterior plate to an intermediate portion of the support plate. 7. An outer panel mounting structure for covering the outer peripheral surface of a cylindrical body through which a high-temperature fluid flows with a plurality of sheets, wherein a plurality of flat plate rings are mounted on the outer circumferential surface of the cylindrical body, and between the upper and lower sides of the flat plate ring. Attaching an exterior plate, wherein an overlapping portion of the adjacent exterior plates is arranged, and an end of each of the exterior plates avoiding the overlapping portion is movably fixed to the flat plate ring with a stopper. Construction.