JPH11350976A - Joint structure of exhaust gas duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damages on the bellows at the joint as well as cracking in weld portions for installing the bellows, regarding the joint structure of the inclined expansion portion of the high temperature exhaust gas duct of the gas turbine. SOLUTION: With maintaining a predetermined interval between the silencer duct blocks 23A, 23B, a bellows 30 is installed between frames 1, 2. Surfaces of the frames 1, 2 are inclined to the directions opposing to each other, bottoms of which are welded to flanges 5, 6. The flanges 5, 6 are mounted on the peripheries of the blocks 23A, 23B by means of heat insulators 35, 36. To the flanges 5, 6, one ends of suspension lugs 7, 8 are fixed, respectively. The other ends are attached to the blocks 23A, 23B, respectively. Further, to the back stays 40, 41, stoppers 15, 16 are mounted, respectively preventing deformation of the frames 1, 2. Since the suspension lugs 7, 8 prevent hanging down and swinging of the frames, the bellows 30 is free from constrained forces, and cracking is not generated in the weld portions by which the frames 1, 2 are mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure for a tilted expansion section of a high-temperature exhaust gas duct, and is mainly applied to an exhaust duct of a gas turbine. This is a structure for preventing

[0002]

2. Description of the Related Art FIG. 4 is a perspective view of an exhaust duct of a gas turbine. In the figure, reference numeral 21 denotes a gas turbine outlet duct, which is connected to an outlet of the gas turbine. 22 is a diffuser duct which is circular and gradually expands.
Reference numeral 23 denotes a silencer duct, which is a square duct, whose cross section is gradually enlarged.
3 (B), and both blocks are connected by an expansion joint 25 so as to be able to expand and contract as described later. Reference numeral 24 denotes an exhaust heat recovery side outlet. Due to such a duct structure, high-temperature exhaust gas from the gas turbine flows in from the gas turbine outlet duct 21 and the exhaust heat recovery side outlet 24.
Leaks to

FIG. 5 is a sectional view taken along line YY in FIG.
The expansion joint 25 is shown. In the figure, between the blocks 23 (A) and 23 (B) of the silencer duct 23 having a square shape, the periphery is connected by a bellows 30 having a shape that can be expanded and contracted while maintaining a predetermined gap. The bellows 30 is made of glass cloth, Teflon, or the like, and is attached in a shape having a margin so as to be deformable. Flanges 31 and 32 are attached around ends of both blocks 23 (A) and 23 (B) via heat insulating materials 35 and 36, respectively.
Reference numeral 34 is attached by being reinforced by reinforcing members 37 and 38, respectively. Bellows 3 between the flanges 33 and 34
0 is attached so that it can expand and contract, and both blocks 23 (A), 2
3 (B) are connected.

FIG. 6 is a partially enlarged view of FIG. 5, and shows a block 23 (A). The bellows 30 is attached to the flange 33 as shown in FIG.
3 is attached by welding vertically to the horizontal surface of the flange 31, the difference in thermal expansion of the duct generated during operation of the gas turbine,
Alternatively, a deformation occurs due to the shrinkage during the stop, which remains as a residual deformation during the stop, causing a deflection to cause damage to the bellows 30 and a crack in a welded portion.

That is, as shown in FIG.
Since the bellows 30 is pulled to the right side as shown by the arrow, or the bellows 30 is pulled to the left side as shown at 33b, the bellows 30 may be damaged, or the bellows 30 may be damaged. Cracks may occur in the welds to the weld. Therefore, there is a demand for a structure of the expansion joint portion 25 that prevents an unnecessary force from being applied to the bellows 30 due to such thermal stress and that does not cause welding cracks at the mounting portion of the flange 33.

[0006]

As described above, the expansion joint portion of the conventional exhaust duct of a gas turbine is deformed by thermal stress, giving an excessive tensile force to the bellows and causing the bellows to be mounted on the flange. There are problems such as cracks in the weld and damage to the bellows, and measures have been desired.

In view of the above, the present invention provides a mounting structure of a telescopic member for reducing the influence of thermal stress on an expansion joint in an exhaust duct of a gas turbine. It is an object of the present invention to provide a connection structure of an exhaust gas duct capable of preventing breakage of the exhaust gas.

[0008]

The present invention provides the following means (1) and (2) to solve the above-mentioned problems.

(1) A front duct and a rear duct for guiding the exhaust gas of a gas turbine are connected to each other, and both ducts gradually increase in cross section from an inlet side to an outlet side, and are connected to each other. In the exhaust gas duct connecting structure, a frame having opposite surfaces is attached to the outer periphery of both ends of the duct, and an elastic member is attached between the opposite surfaces of the two frames. And a support member for connecting between the outer periphery of each duct to which the both frames are attached, and a member which has one end fixed to the outside of each of the ducts and the periphery of the distal end of each frame at the other end. A connection structure for an exhaust gas duct, comprising a stopper for preventing the exhaust gas from being inclined in a pulling direction.

(2) In the invention of the above (1), the two frames are opposed to each other, and the surfaces on which the extensible members are attached are inclined toward the opposite side. .

In (1) of the present invention, since the frame on which the elastic material for connecting the front duct and the rear duct is attached is supported by the duct on both sides by the supporting members, the frame is deformed by thermal deformation. It is supported and prevented from hanging down on the surface side of. The support member also prevents the frame from being deformed by thermal stress in the front-rear direction of the duct.

Further, a stopper is attached to the fixed side, for example, a back stay, which is a structural member around the outside of the duct, and when the frame pulls the elastic member to incline to the opposite side to the member, the stopper inclines excessively. This prevents the frame from tilting, prevents an excessive force from being applied to the elastic member, and prevents damage to the member. Also, by preventing the frame from being deformed and inclined in the front-rear direction, cracks in the welded portion to which the frame is attached are not generated, and damage to the connecting portion due to thermal stress of the exhaust gas duct is prevented, thereby improving reliability.

According to (2) of the present invention, the connecting portion is formed such that the frames are attached to each other so that the surfaces facing each other are inclined, and the frame is formed so as to form a smooth curved mountain-like shape with the elastic members to be connected. Is distributed at the mounting portion of the frame, and the frame is prevented from being pulled and inclined by the member. Therefore, the deformation due to the inclination of the frame is reduced, and the effect (1) is ensured.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view of a connection structure of a high-temperature exhaust gas duct according to an embodiment of the present invention, and is a view corresponding to a sectional view taken along line YY in FIG.

In FIG. 1, the blocks 23 (A) and 23 (B) of the expansion joint 25 are kept at a predetermined interval, and flanges 5 and 6 are attached around respective ends via heat insulating materials 35 and 36. Have been. On the peripheral surfaces of the flanges 5 and 6, the surfaces facing the frames 1 and 2 are formed at a predetermined pitch so as to be inclined to each other, the lower ends thereof are attached by welding, and the upper ends of the frames 1 and 2 are
4 is bent so as to have a surface to be fitted.

A bellows 30 is attached to the inclined surfaces of the frames 1 and 2, and the upper surfaces thereof are pressed by pressing plates 3 and 4. The bellows 30 is attached with a curved surface so that the outside forms a mountain shape in consideration of the expansion width as in the conventional case.

One end of each of ribs 11 and 14 is vertically attached to the flanges 5 and 6 at a predetermined pitch on the peripheral surface by welding, and mounting members 9, 10 and 12 and 13 are provided on both sides of the ribs 11 and 14. Bolts and nuts are connected to each other, and one ends of the suspension lugs 7, 8 are sandwiched in upper gaps, and the lower ends of the suspension lugs 7, 8 are fixed by bolts and nuts. Hanging lugs 7, 8
Are attached to the surfaces of the blocks 23 (A) and 23 (B) by welding, respectively.

Back stays 40, 41 are disposed above the blocks 23 (A), 23 (B). One ends of stoppers 15, 16 are attached to the back stays 40, 41, respectively. Each prevents the frames 1 and 2 from moving outward and deforming, thereby preventing the bellows 30 from being pulled.

FIG. 2 is a partially enlarged view of FIG. 1 and shows only the block 23 (A) of the expansion joint 25. As shown, one end of the suspension lug 7 is fixed to the surface of the block 23 (A), and the other end is welded to the flange 5 to support the flange 5 so as to prevent the flange 5 from hanging down. To prevent the welded portion of the flange 5 and the frame 1 from cracking. Note that one end of the suspension lug 7 may be welded to the reinforcing member 37 depending on the location.

As shown, one end of the stopper 15 is attached to the back stay 40, and the surface 15a of the stopper 15 is
To prevent the frame 1 from tilting and deforming to the left, to prevent the frame 1 from swaying, to prevent the welded portion at the lower end of the frame 1 from cracking, and to prevent an excessive tensile force from being applied to the bellows 30. You. Further, the surface of the frame 1 is inclined rightward as shown in the figure, and is smoothly joined so as to approach the curved surface of the bellows 30.
Alternatively, consideration is given to dispersing the force on the frame 1 due to the rightward movement to reduce this effect.

FIG. 3 is a view taken along line XX in FIG.
The arrangement of the suspension lugs 7 and the stoppers 13 is shown. The suspension lugs 7 are attached at predetermined intervals around the block 23 (A) of the silencer duct 23, fix and support the flange 5 and the frame 1, and weld by deformation thereof. Prevent cracking of parts. The stopper 15 is also provided at a predetermined interval with the back stay 40.
To prevent the frame 1 from moving. The positions of the suspension lugs 7 and the stoppers 15 are shifted relative to each other, and the suspension lugs 7 and the stoppers 15 are mounted at positions where they do not interfere with each other.

According to the embodiment described above, the expansion joint 25 of the exhaust duct of the gas turbine is used.
, Frames 1 and 2 having inclined surfaces facing each other via brackets 5 and 6 are attached to the peripheral ends of the blocks 23 (A) and 23 (B).
Since the bellows 30 was attached between the two and the frames 1 and 2 were attached so as to smoothly follow the curved surface of the bellows 30,
Even when receiving the tensile force of the bellows 30, the inclination of the frames 1 and 2 is reduced, and the influence of the tensile force is reduced.

The suspension lugs 7 and 8 are
(A), 23 (B), and supports the frames 1 and 2 via the flanges 5 and 6 to prevent the frames 1 and 2 from hanging down and to prevent the frames 1 and 2 from moving due to deformation in the longitudinal direction. And cracks in the weld can be prevented.

Further, the stoppers 15 and 16 are fixed to the back stays 40 and 41 to prevent the frames 1 and 2 from moving in the longitudinal direction, to eliminate an excessive tensile force of the bellows 30 due to this deformation, and to damage the bellows 30. In addition, cracking of the mounting portion due to welding of the frames 1 and 2 can be prevented.

[0025]

The connection structure of the exhaust gas duct of (1) of the present invention connects the front duct and the rear duct for guiding the exhaust gas of the gas turbine, and both ducts are connected from the inlet side to the outlet side. Along with gradually increasing the cross section, the connecting portion of the two ducts is attached with a frame having opposing surfaces around the outer ends of both ducts, and an elastic member is attached between the opposing surfaces of the two frames. In the exhaust gas duct connection structure that is configured, a support member that connects between the two frames and the outer periphery of each duct to which the two frames are attached, and one end fixed to the outside of the two ducts, and the other end A stopper is provided to prevent the periphery of the distal end of each of the frames from inclining in the direction in which the elastic member is pulled. With such a structure, the support member prevents the frame from being excessively tilted or sagged, and the stopper prevents the frame from being tilted by pulling the stretchable member. Thus, the elastic member can be prevented from being damaged, and weld cracking of the frame mounting portion can be prevented.

According to a second aspect of the present invention, in the first aspect of the present invention, the two frames are opposed to each other, and a surface on which the extensible member is attached is inclined toward the opposite side. . With such a structure, the stretchable member is smoothly connected to the frame, the tensile force applied to the frame by the member is dispersed, and the influence of the member due to thermal stress is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a connection structure of an exhaust gas duct according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of FIG. 1 showing a front block portion.

FIG. 3 is a view taken along the line XX in FIG. 2;

FIG. 4 is a general perspective view of an exhaust duct of a gas turbine.

FIG. 5 is a sectional view taken along line YY in FIG. 4;

FIG. 6 is a partially enlarged cross-sectional view of FIG. 5, showing a front block portion.

[Explanation of symbols]

1, 2 Frame 3, 4 Pressing plate 5, 6 Flange 7, 8 Hanging lug 9, 10, 12, 13 Attachment material 11, 14 Rib 15, 16 Stopper 23 Silencer duct 23 (A), 23 (B) Block 25 Expansion Joint part 30 Bellows 40, 41 Backstay

Claims (2)

[Claims] A front duct and a rear duct for guiding exhaust gas of a gas turbine are connected, and both ducts gradually increase in cross section from an inlet side to an outlet side, and a connection portion between the two ducts. A frame having an opposing surface is attached to the outer periphery of both ends of the duct, and an exhaust gas duct connecting structure comprising an extensible member is attached between the opposing surfaces of the two frames. A support member for connecting the outer periphery of each of the ducts to which the both frames are attached, and a member having one end fixed to the outside of each of the ducts, and the periphery of the distal end of each of the frames at the other end being an elastic member. A connection structure for an exhaust gas duct, comprising a stopper for preventing the exhaust gas from being inclined in a pulling direction. 2. The exhaust gas duct connection structure according to claim 1, wherein the two frames face each other, and surfaces on which the elastic members are attached are inclined toward the opposite side.