JPH0544903A - Expansion joint of boiler - Google Patents

Abstract

PURPOSE:To make less stress working concentratedly at the end section and eliminate the generation of damage such as cracks, open breakage, etc., by providing a cover of box shape that is installed to a bend plate at its end section so as to surround it. CONSTITUTION:An expansion joint 3 is installed with its bent plate spanning a slit provided at the casings 4, 5 of a boiler like a bridge over the slit. In the casings 4 and 5, expansion and shrinkage develop in the direction shown by the arrow marks 12, 13. And, the expansion joint 3 is given a displacement that is shown by the arrow mark 14 due to the expansion and shinkage shown by the arrow marks 12, 13 in the casings 4, 5, and this displacement generates a displacement near the end section 8 of the expansion joint 3 in the direction shown by the arrow mark 15. In order to keep the expansion joint 3 from damages for those displacements a displacement baffling box 1 is installed at the end section 8 of the expansion joint 3. The corner 9 of this displacement baffling box can be a bend at right angle or can be a curve at the corner in order to disperse the forces acting on the comer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler expansion joint applied to thermal power generation and the like.

[0002]

5 and 6 are explanatory views of a conventional expansion joint of a boiler used in thermal power generation and the like. In the figure, reference numerals 4 and 5 denote boiler casings, and 101.
Is an expansion joint, 102 is an expansion joint 101 and a casing 4,
A welded portion connecting 5 and 103 is an end portion of the expansion joint 101. In this expansion joint, the slits provided in the casings 4 and 5 of the boiler are attached by a curved plate in a crotch-like manner, and the combustion gas of the boiler is sealed while allowing expansion and contraction of the casings 4 and 5 of the boiler. Sealability is required.

[0003]

In the expansion joint of the conventional boiler as described above, arrows 1 are provided on the casings 4 and 5.
Expansion and contraction occur in the directions indicated by 2 and 13. Also, expansion joint 1
01 also expands and contracts in the directions indicated by arrows 16 and 17. Therefore, a large stress acts on the end portion 103 of the expansion joint 101. Further, the expansion joint 101 is expanded and contracted in the directions shown by the arrows 12 and 13 in the casings 4 and 5 so that the arrow 14
A displacement in the direction indicated by is generated, and this displacement causes a displacement in the direction indicated by an arrow 105 in the vicinity of the end 103 of the expansion joint 101, and excessive stress acts on the end 103 of the expansion joint 101.
Further, the expansion joint 101 is displaced on the upper surface in the directions indicated by the arrows 16 and 17, and the end portion 103 of the expansion joint 101 is displaced three-dimensionally in the direction indicated by the arrow 104 to generate the end portions 103.
Stress acts on. As shown in FIG.
As shown in (3), it acts intensively on the end portion 103 of the expansion joint 101. Since recent boilers are operated according to fluctuations in power demand during the day and night, the frequency of starting and stopping is particularly high, and the expansion joint 101 is repeatedly subjected to expansion and contraction stress to cause cracks or breaks in the expansion joint 101. Is frequently damaged.

[0004]

The expansion joint of the boiler according to the present invention is intended to solve the above-mentioned problems, and a slit provided in the casing of the boiler is attached to the bending plate in a bridging manner in a crotch manner. An expansion joint of a boiler that seals combustion gas of the boiler while allowing expansion and contraction is characterized by including a box-shaped cover mounted so as to surround the end of the curved plate.

[0005]

That is, in the expansion joint of the boiler according to the present invention, the slit provided in the casing of the boiler is attached by the curved plate in a bridging manner so as to allow expansion and contraction of the casing and seal the combustion gas of the boiler. A box-shaped cover is mounted so as to surround the end portion of the curved plate in the expansion joint, and the stress concentrated on the end portion due to the displacement of the casing is dispersed and absorbed by the box-shaped cover to be reduced.

[0006]

1 and 2 are explanatory views of a boiler expansion joint according to an embodiment of the present invention, and FIGS. 3 and 4 are explanatory views of a boiler expansion joint according to an application example thereof. Figure 1
In the above, the expansion joint of the boiler according to the present embodiment is a boiler used in thermal power generation and the like, 1 is a displacement relaxation box, 2 is a flange of the relaxation box 1, 3 is an expansion joint, 4 and 5 are casings, 6 is a weld connecting the relaxation box 1 and the casings 4, 5; 7 is a weld connecting the expansion joint 3 and the casings 4, 5; 8 is an end portion of the expansion joint 3; and 9 is a corner of the relaxation box 1. .. In this expansion joint, the slits provided in the casings 4 and 5 of the boiler are attached by a bent plate in a bridging manner, and the combustion gas of the boiler is sealed while allowing expansion and contraction of the casings 4 and 5 of the boiler. Sealability is required.

The casings 4 and 5 expand and contract in the directions shown by arrows 12 and 13. In addition, the expansion joint 3 also has an arrow 1
Expansion and contraction occur in the directions indicated by 6 and 17. Also, expansion joint 3
The casings 4 and 5 are expanded and contracted in the directions indicated by the arrows 12 and 13 to cause displacement in the direction indicated by the arrow 14, and this displacement causes displacement in the direction indicated by the arrow 15 near the end 8 of the expansion joint 3. In addition, the arrow 16, on the upper surface of the expansion joint 3,
A displacement in the direction indicated by 17 occurs, and a three-dimensional displacement in the direction indicated by the arrow 18 occurs at the end 8 of the expansion joint 3. Since recent boilers are operated according to fluctuations in power demand day and night, the frequency of starting and stopping is particularly high, and such displacement is repeatedly generated and stress is concentrated on the end 8 of the expansion joint 3. In order to prevent the expansion joint 3 from being damaged by the action, a displacement relaxation box 1 is attached to the end portion 8 of the expansion joint 3 as shown in the figure. Although the corner 9 of the relaxation box 1 is bent at a right angle, the corner 10 may be curved to disperse the stress acting on the corner 10 as shown in FIG. 3, and as shown in FIG. The entire relaxation box 11 may be rounded to disperse the stress.

In this way, by mounting the displacement relaxation box 1 on the end 8 of the expansion joint 3, the casing 4,
Even if the end portion 8 of the expansion joint 3 is displaced in the direction indicated by the arrow 15 due to the displacement in the directions indicated by arrows 12 and 13 in FIG. 5, the relaxation box 1 attached to the end portion 8 of the expansion joint 3
Since this displacement is dispersed and absorbed to be suppressed, the stress acting on the end portion 8 of the expansion joint 3 can be suppressed to be small. Also,
The displacement in the direction indicated by the arrows 16 and 17 generated in the expansion joint 3 causes the displacement in the direction indicated by the arrow 18 at the end portion 8 by the displacement of the side plate of the relaxation box 1, and the stress is reduced. When these are combined, the stress acting due to the displacement at the end 8 is reduced by the width of the relaxation box 1,
By appropriately setting the height and the like, the height can be reduced to a fraction of one as shown in FIG.

In this way, this expansion joint is expanded joint 3
By mounting the displacement relaxation boxes 1 and 11 on the end portion 8 of the, the stress concentrated on the end portion 8 of the expansion joint 3 is absorbed and relaxed by the relaxation box 1 to be reduced to a fraction. Since the fatigue development at the end 8 of the expansion joint 3 can be kept very small and the strength can be improved, damages such as cracks and breaks at the end 8 of the expansion joint 3 can be eliminated.

[0010]

The expansion joint of the boiler according to the present invention is constructed as described above, and the stress concentrated on the end is reduced, so that damage such as cracks and breakages is eliminated.

[Brief description of drawings]

1 (a) is a perspective view of an expansion joint of a boiler according to an embodiment of the present invention, FIG. 1 (b) is a plan view, FIG. 1 (c),
(D) is sectional drawing.

FIG. 2 is an explanatory view of its operation.

FIG. 3 is a sectional view of an expansion joint of a boiler according to the application example.

FIG. 4 is a perspective view of an expansion joint of a boiler according to another application example.

FIG. 5 (a) is a perspective view of an expansion joint of a conventional boiler, and FIG. 5 (b) is a plan view thereof.

FIG. 6 is an explanatory diagram of its operation.

[Explanation of symbols]

 1 Displacement relaxation box 2 Flange 3 Expansion joint 4 Boiler casing 5 Boiler casing 6 Welded portion 7 Welded portion 8 Expansion joint end 9 Relaxation box corner 10 Relaxation box corner 11 Displacement relaxation box

Claims (1)

[Claims] 1. An expansion joint of a boiler for sealing a combustion gas of the boiler while permitting expansion and contraction of the casing by mounting a slit provided on the casing of the boiler in a bridging manner to allow the expansion and contraction of the casing. An expansion joint for a boiler, which is equipped with a box-shaped cover that is mounted so as to surround the ends.