JP2002361523A - Method for repairing plate-like body having flow passage inside thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a plate-like body having a flow passage inside thereof at a relatively low cost without degrading functions such as cooling. SOLUTION: The method for repairing the plate-like body 1 having the flow passage 2 inside thereof comprises (a) a groove forming step of forming a welding groove 4 by grinding a cracked part 3 of the plate-like body 1, (b) a plugging step of plugging a bottom part of the groove 4 by welding, (c) a groove forming step of cutting a groove 7 of substantially same depth as the bottom part of the flow passage 2 in the groove 4, (d) a bottom surface smoothing step of removing a weld metal 5 protruded from the bottom surface of the plate-like body 1 by the welding to the groove 4 in the plugging step, and (f) a lid fitting step of fitting a lid plate 8 to an opening part in the surface of the plate-like body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing cracks generated in a plate having a flow path therein.

[0002]

2. Description of the Related Art A plate-like body having a stripe-like flow path inside is used as a constituent material of a gas turbine combustor, a jet engine, a space-related equipment, and the like today. It is configured to exert an action such as cooling by flowing a working fluid such as steam.

As shown in FIG. 2, for example, a gas turbine combustor 20 generally includes a fuel supply unit 21 and a transition piece 22 for guiding high-temperature and high-pressure combustion gas to a turbine (not shown). I have. This fuel supply unit 21 is provided with a pilot fuel X
And a cone 23 for supplying air and forming a diffusion flame;
Nozzle 2 for ejecting premixed gas of main fuel Y and air
4 and a so-called multi-nozzle type in which a plurality of nozzles 24 are arranged around the cone 23 at substantially equal intervals.

[0004] The transition piece 22 joins a plurality of plate-like bodies 25,
It is formed in a cylindrical shape. As shown in FIG. 3, the plate 25 is generally formed by laminating one wall 26 having a striped groove and the other flat plate 27 by brazing or the like. A striped flow path 28 is defined between the walls 26 and 27 in parallel with the plate surface. During operation of the gas turbine combustor 20, a working fluid Z (FIG. 2) such as air or steam flows through the flow path 28 in the transition piece 22.
The transition piece 22 is cooled.

[0005] In the transition piece 22 of the gas turbine combustor 20 having the above structure, a linear crack 29 as shown in FIG. 4 may be generated due to thermal cycle fatigue during operation.
Conventionally, as a method for repairing such cracks 29, (1)
As shown in FIG. 5, the crack 29 of the plate-like body 25 is deleted to form a groove 30 for welding.
A method of filling the weld metal 31 by welding or the like; (2)
In the transition piece 22, the plate-like body 25 where the crack 29 has occurred
A method of cutting the whole and replacing it with a new plate-like body 25 has been adopted.

[0006]

In the repair method (1), the flow path 28 is closed by the weld metal 31 as shown in FIG. 5, and as a result, the flow path 28 passing through the repair location is closed.
However, there is an inconvenience that the cooling capacity of the zone in which is present is reduced. On the other hand, in the repairing method (2) described above, the cooling capacity does not decrease, but there is an inconvenience that the repair cost is increased because the entire plate-like body 25 in which the crack 29 has occurred is replaced.

[0007] Needless to say, the inconvenience of such a repairing method also applies to the case other than the transition piece 22 of the gas turbine combustor 20. In other words, a plate-like shape having a flow path through which a certain working fluid flows inside. This is an issue that applies to the whole body.

The present invention has been made in view of these inconveniences, and has a plate-like body having a flow path therein without causing a reduction in various functions such as cooling and having a relatively low repair cost. The purpose is to provide a repair method.

[0009]

According to a first aspect of the present invention, there is provided a method for repairing a plate having a flow path therein, comprising the steps of: Forming a groove for welding by removing the cracked portion of (a), (b) filling the bottom of the groove by welding, and (c) forming an opening in the surface of the plate-like body. And a lid attaching step of attaching a lid plate.

In the repairing method, a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow path in the groove portion after the filling step as in the present invention according to claim 2. It is preferable to have

Preferably, after the filling step, a bottom surface smoothing step of removing a weld metal protruding from the bottom surface of the plate-like body by welding to a groove as in the present invention according to claim 3 is preferable.

Further, according to the present invention described in claim 4,
It is preferable that the lid plate used in the lid attaching step is provided with a convex portion that can be inserted into an opening in the surface of the plate-like body, and the height of the convex portion is plate-like as in the present invention according to claim 5. The vertical length from the body surface to the top of the flow path is preferably substantially the same, and the same material as that of the plate-like body is used as the material of the lid plate as in the present invention according to claim 6. Is preferred.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a repair method according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. However, as will be understood from the following description, the present invention is limited to this embodiment. Instead, various modifications are possible.

FIGS. 1 (a) to 1 (f) illustrate various steps of a plate-like body having a flow path therein for explaining each step of a plate-like body repair method according to an embodiment of the present invention. It is a figure showing a state in section. The repair method shown in FIG. 1 is a repair method when a linear crack 3 penetrating a plate-like body 1 having a flow path 2 therein as shown in FIG. A filling step, a groove forming step, a bottom surface smoothing step,
And a lid attaching step in this order.

In the groove forming step, as shown in FIG. 1 (b), the periphery of the crack 3 (the portion where the crack occurs) along the crack 3 in the plate-like body 1 is removed by a grinder or the like, and the V-shape is formed. This is a step of forming the groove-shaped groove 4.

In the filling step, as shown in FIG.
In this step, the bottom of the groove 4 (the portion corresponding to the region from the bottom surface of the plate-like body 1 to the bottom of the flow path 2) is filled with a weld metal 5 by welding. As a welding method used in the filling step, for example, TIG welding, MIG welding, plasma welding, carbon dioxide arc welding, MAG welding, or the like can be applied, but is not particularly limited thereto.

The groove forming step is a step of forming a concave groove 7 in a portion including the groove 4 as shown in FIG. The depth of the concave groove 7 is substantially the same as the depth of the bottom of the flow path 2 of the plate-like body 1. The means for engraving the groove 7 in the groove forming step is not particularly limited, and a general cutting / grinding means such as a grinder is employed.

In the bottom surface smoothing step, the groove 4 is formed by the filling step.
As shown in FIG. 1D, a portion of the weld metal 5 filled at the bottom of the plate-like member protruding from the bottom surface of the plate-like body 1 (see FIG. 1C) is deleted as shown in FIG. This is the step of finishing the surface of the product. As a means for removing the protruding portion of the weld metal 5 in the bottom surface smoothing step, a general cutting / grinding means such as a grinder is employed as in the groove forming step. Note that, regardless of the order of the bottom surface smoothing step and the above-described groove forming step, both steps can be performed simultaneously.

The lid attaching step includes a detailed step of attaching the lid plate 8 and a joining step. This mounting process is shown in FIG.
(E), a cover plate 8 is attached to the surface of the plate 1 so as to cover the opening of the surface of the plate 1 formed in each of the above steps, that is, the opening of the groove 7. . In the joining step, as shown in FIG. 1F, the outer edge of the cover plate 8 is welded, and the plate-like body 1 and the cover plate
This is the step of joining The welding method used in this joining step is the same as the filling step described above, and includes, for example, TIG welding, MIG welding, plasma welding, carbon dioxide arc welding, MAG welding and the like.

The lid plate 8 used in the lid attaching step has a convex portion 9 on its back surface that can be loosely fitted into the opening of the groove 7, and the convex portion 9 is inserted into the opening of the groove 7 in the attaching step. The cover plate 8 is attached so as to perform. The height of the convex portion 9 of the cover plate 8 is
The vertical length from the surface of the plate 1 to the top of the flow path 2 is substantially the same. Therefore, when the lid plate 8 is attached in the lid attaching step, the tip end surface or lower surface of the convex portion 9 of the lid plate 8 and the top of the flow path 2 are located on substantially the same reference plane parallel to the plate 1.

The material of the cover plate 8 is not particularly limited as long as it has the strength, heat resistance, and the like required for the plate-like body 1. For example, stainless steel, heat-resistant steel, or the like can be used. . In particular, as the material of the cover plate 8,
It is preferable to use the same material as that of the above, and it is possible to reduce the falling off of the cover plate 8 under the thermal cycle due to the difference in the expansion coefficient.

By going through the groove forming step, filling step, groove forming step, bottom flattening step and lid attaching step, FIG.
The repair of the crack 3 generated in the plate-like body 1 is completed as shown in FIG. A hollow portion 11 communicating with the flow path 2 is formed between the bottom surface of the groove 7 and the tip end surface of the convex portion 9 of the cover plate 8 at the repair location where the repair method has been applied, and Road 2
However, there is no blockage at the repair location. As a result, the plate 1
Various functions such as cooling by flowing the working fluid through the flow path 2 can be maintained. In addition, since the hollow portion 11 and the flow path 2 are connected linearly when the plate-like body 1 is viewed from the side, the formation of a stream line of the working fluid flowing through the flow path 2 is promoted, and an increase in pressure loss due to a repair portion is increased. Can be reduced.

The method of repairing a plate-like body having a flow path therein is not limited to the above embodiment, and various modifications are possible. For example, (1) the groove forming step and the bottom surface smoothing step can be omitted, and the same effect can be obtained if only the bottom of the groove 4 can be filled with the weld metal 5 to some extent accurately in the filling step. Can be.

(2) As the cover plate 8 used in the cover attaching step, a cover plate 8 having no convex portion 9 can be used, and the effect of preventing the flow path 2 from being blocked at the repaired portion can be exhibited. Also, the height of the protrusion 9 is not limited to be substantially the same as the length from the surface of the plate-like body 1 to the flow path 2 and can be changed. By adjusting the height of the projection 9 in this manner, the flow rate of the working fluid flowing through the flow path 2 can be controlled.

(3) In the embodiment shown in FIG. 1, the cross-sectional shape of the groove 7 is substantially square or rectangular, and the convex portion 9 that is loosely fitted to the groove 7 has a similar shape that complements the groove 7. It is preferable to form the groove 7 in terms of processing the groove 7. However, when the groove is provided, the shape is not limited to the shape, and may be any shape as long as the cover plate 8 can be attached.

(4) The term "crack-occurring portion" used in this specification does not refer only to a portion where a crack has actually been confirmed by visual observation, but rather to a portion where a crack has actually occurred. Needless to say, it includes a portion that is highly likely to occur and a portion that is likely to be generated by the metal structure inspection.

[0027]

According to the repair method of the present invention, first, a groove is formed at a crack generating portion of the plate-like body by a groove forming step, and then the bottom of the groove is welded by a filling step. Then, a cover plate is attached to the opening on the surface of the plate-like body in the lid attaching step, whereby repair of cracks generated in the plate-like body having a flow path therein is completed. Therefore, according to the repair method, a hollow portion is formed between the bottom filled in the filling step and the lid plate attached in the lid attaching step. Therefore, it is possible to prevent the flow path inside the plate-like body from being blocked at the repair location, and as a result,
By circulating the working fluid through the flow path of the plate-like body, it is possible to prevent a reduction in various functions such as cooling. For example,
When the repair method is used to repair cracks generated in the transition piece of the gas turbine combustor, the cooling capacity of the transition piece can be maintained. Further, since it is not necessary to replace the entire cracked plate-like body as in the conventional repair method, the repair cost can be reduced.

According to the second aspect of the present invention,
After the filling step, a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow path in the groove is provided. A groove having the same depth is formed, and the bottom of the flow path of the plate-like body and the bottom of the hollow formed in the repair location can be made to substantially coincide with each other. As a result, the repair location of the working fluid flowing through the flow path Streamlines can be promoted. Further, even if the weld metal overlaps with the groove surface opening of the flow channel by welding to the groove bottom in the filling step, the overlapped portion is removed by the groove forming step. Does not need to be performed very accurately, and the workability of the filling step can be improved.

Further, after the filling step, as in the present invention according to claim 3, a bottom surface smoothing step of removing a weld metal protruding from the bottom surface of the plate-like body by welding to a groove is provided. In the bottom surface smoothing step, the bottom surface of the plate-like body is finished flush, and in a product using the plate-like body having a flow path (for example, a transition piece of a gas turbine combustor), the function of the product (for example, combustion) Adverse effects on the flow of gas, etc.) can be prevented.

Further, according to the present invention described in claim 4,
When the lid plate used in the lid attaching step is provided with a convex portion that can be inserted into the opening on the surface of the plate-like body, the lid plate is attached so that the convex portion is inserted into the opening on the surface of the plate-like body. In addition, the space above the hollow portion formed at the repair location can be reduced, and an increase in pressure loss due to the difference between the cross-sectional shape of the hollow portion and the cross-sectional shape of the flow path of the plate-like body can be reduced. Also, by adjusting the height of the convex portion of the lid plate, the flow rate of the working fluid flowing through the flow path of the plate-like body can be controlled.

According to the fifth aspect of the present invention, a cover plate having a convex portion having substantially the same height as the vertical length from the surface of the plate to the flow path is used, and the cover is attached to the surface of the plate. By being attached to the opening, the upper surface of the hollow portion formed at the repair location and the top of the flow path of the plate-like body can be positioned substantially on the same line as viewed from the plate-like body surface side, and the flow path and the repair place It is possible to further promote the formation of a stream line of the working fluid flowing through the hollow portion.

Further, according to the present invention described in claim 6,
Since the cover plate and the plate-like body are made of the same material, the expansion coefficients of the plate-like body and the cover plate can be matched, so that
It is possible to prevent the cover plate from falling off or being damaged under a heat cycle.

[Brief description of the drawings]

FIGS. 1A to 1F are cross-sectional views of a plate for explaining a method of repairing the plate according to an embodiment of the present invention. In addition, the cut surface of each cross-sectional view is a surface parallel to the plate surface of the flow path and the plate-like body.

FIG. 2 is a sectional view showing a general gas turbine combustor.

FIG. 3 is a partial cross-sectional view of a plate-like body constituting a transition piece of the gas turbine combustor of FIG. 2;

FIG. 4 is a side view showing a state in which a crack has occurred in a transition piece of the gas turbine combustor of FIG. 2;

FIG. 5 is a cross-sectional view showing a state in which cracks generated in a plate-like body constituting the transition piece are repaired by a conventional repair method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-shaped body 2 Flow path 3 Crack 4 Groove 5 Weld metal 7 Groove 8 Cover plate 9 Convex part 10 Weld metal 11 Hollow part

Claims (6)

[Claims] 1. A method for repairing a plate-like body having a flow path therein, comprising: a groove forming step of forming a groove for welding by removing a cracked portion of the plate-like body; A repairing method, comprising: a filling step of filling the bottom of the plate by welding, and a lid attaching step of attaching a lid plate to the opening of the groove that opens on the surface of the plate-like body. 2. The repair method according to claim 1, further comprising, after the filling step, a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow channel in the groove. 3. The repair method according to claim 1, further comprising a bottom surface smoothing step of removing a weld metal protruding from a bottom surface of the plate-like body by welding to the groove after the filling step. 4. The plate according to claim 1, wherein the cover plate used in the step of attaching the cover includes a convex portion that can be inserted into the opening that opens on the surface of the plate-like body. Repair method. 5. The repair method according to claim 4, wherein the height of the projection is substantially the same as the length from the surface of the plate to the top of the flow path. 6. The repair method according to claim 1, wherein the same material as that of the plate is used as a material of the cover plate.