JP3581672B2 - Method for repairing plate-like body having flow path inside - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for repairing a crack generated in a plate-like body having a flow path therein.
[0002]
[Prior art]
Today, plate-like bodies having a flow path such as a stripe shape are used as constituent materials for gas turbine combustors, jet engines, space related equipment, etc., and working fluids such as air and steam are used in the internal flow path. Is configured to exert an action such as cooling by flowing air.
[0003]
As shown in FIG. 2, for example, the gas turbine combustor 20 generally includes a fuel supply unit 21 and a transition piece 22 that guides high-temperature and high-pressure combustion gas to a turbine (not shown). The fuel supply unit 21 includes a cone 23 that supplies a pilot fuel X and air to form a diffusion flame, and a nozzle 24 that ejects a premixed gas of the main fuel Y and air. , A so-called multi-nozzle type arranged at substantially equal intervals.
[0004]
The transition piece 22 is formed by joining a plurality of plate-like bodies 25 and forming the same into a tubular shape. As shown in FIG. 3, this plate 25 is generally formed by laminating one wall 26 having a striped groove and the other plate 27 by brazing or the like. And 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, and the transition piece 22 is cooled.
[0005]
In the transition piece 22 of the gas turbine combustor 20 having the above-described structure, a linear crack 29 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, a crack 29 portion of the plate-shaped body 25 is deleted to form a groove 30 for welding, and TIG welding or the like is formed on the groove 30. And (2) cutting the entire plate-like body 25 in which the crack 29 has occurred in the transition piece 22 and replacing it with a new plate-like body 25.
[0006]
[Problems to be solved by the invention]
In the repair method (1), as shown in FIG. 5, the flow path 28 is closed by the weld metal 31, and as a result, the cooling capacity of the zone where the flow path 28 passing through the repair location exists is reduced. There is. On the other hand, in the repairing method (2), the cooling ability does not decrease, but there is an inconvenience that the repair cost is increased because the entire plate 25 having the crack 29 is replaced.
[0007]
Needless to say, the inconvenience of such a repairing method also applies to other than the transition piece 22 of the gas turbine combustor 20. In other words, the entirety of the plate-like body having a flow path for circulating some working fluid therein. This is the relevant issue.
[0008]
The present invention has been made in view of these inconveniences, and provides a method of repairing a plate-like body having a flow path therein without causing a decrease in various functions such as cooling and having a relatively low repair cost. The purpose is to provide.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention according to claim 1 is a method for repairing a plate-like body having a flow path therein, and (a) welding by removing a crack occurrence portion of the plate-like body. A groove forming step of forming a groove for use, (b) a filling step of filling the bottom of the groove by welding, and (c) a lid attaching step of attaching a lid plate to an opening on the surface of the plate-like body. And a repair method characterized by having the following.
[0010]
The repair method includes a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow passage in the groove after the filling step, as in the present invention according to claim 2. Is preferred.
[0011]
Preferably, after the filling step, a bottom surface smoothing step of removing a weld metal projecting 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.
[0012]
Furthermore, as in the present invention as set forth 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 As in the present invention as set forth in claim 5, it is preferable that the vertical length from the surface of the plate to the top of the flow path is substantially the same, and the material of the lid plate is as set forth in claim 6. As in the present invention, it is preferable to use the same material as the plate-like body.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the repair method according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate, but as will be understood from the following description, the present invention is not limited to this embodiment, and various modifications are made. Is possible.
[0014]
FIGS. 1A to 1F are cross-sectional views showing various states of a plate-shaped body having a flow path therein to explain each step of a plate-shaped body repairing method according to an embodiment of the present invention. FIG. The repair method shown in FIG. 1 is a repair method in the case where a linear crack 3 penetrating through 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.
[0015]
In the groove forming step, as shown in FIG. 1 (b), the periphery of the crack 3 (the crack occurrence portion) is removed along the crack 3 in the plate-like body 1 by a grinder or the like, and the V-shaped groove is formed. This is a step of forming the groove 4.
[0016]
In the filling step, as shown in FIG. 1C, the bottom of the groove 4 (the portion corresponding to the region from the bottom of the plate-like body 1 to the bottom of the flow path 2) is welded with a weld metal 5 by welding. This is the step of filling. 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 it is not particularly limited thereto.
[0017]
The groove forming step is a step of engraving 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. Means for engraving the groove 7 in this groove forming step is not particularly limited, and a general cutting / grinding means such as a grinder is employed.
[0018]
In the bottom surface smoothing step, a portion of the weld metal 5 filled in the bottom of the groove 4 in the filling step, which protrudes from the bottom surface of the plate-like body 1 (see FIG. 1C), is formed in FIG. In this step, the bottom surface of the plate-like body 1 is removed as shown in FIG. As a means for removing the projecting 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. In addition, regardless of the order of the bottom surface smoothing step and the above-described groove forming step, both steps can be performed simultaneously.
[0019]
The lid attaching step includes a detailed step of attaching and joining the lid plate 8. As shown in FIG. 1 (e), the mounting step covers the opening of the surface of the plate 1 formed in each of the above steps, that is, the cover of the surface of the plate 1 so as to cover the opening of the groove 7. This is a step of attaching the plate 8. The joining step is a step of welding the outer edge of the cover plate 8 and joining the plate-like body 1 and the cover plate 8 with a weld metal 10 as shown in FIG. The welding method used in this joining step is the same as in the filling step described above, and includes, for example, TIG welding, MIG welding, plasma welding, carbon dioxide arc welding, MAG welding and the like.
[0020]
The lid plate 8 used in the lid attaching step has a convex portion 9 on its back surface that can be loosely fitted in the opening of the groove 7. The lid 9 is inserted into the opening of the groove 7 in the attaching step. Attach plate 8. The height of the convex portion 9 of the cover plate 8 is substantially the same as the vertical length from the surface of the plate-like body 1 to the top of the flow channel 2. 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-like body 1.
[0021]
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, the material of the cover plate 8 is preferably the same as the material constituting the plate-like body 1, so that the drop-off of the cover plate 8 under a thermal cycle due to a difference in expansion coefficient can be reduced.
[0022]
By performing the groove forming step, the filling step, the groove forming step, the bottom surface smoothing step, and the lid attaching step, 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 is applied, and the flow of the plate-like body 1 is formed. Road 2 is not blocked at the repair location. As a result, various functions such as cooling by flowing the working fluid through the flow path 2 of the plate-like body 1 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 streamlining of the working fluid flowing through the flow path 2 is promoted, and the pressure loss due to the repair location is increased. Can be reduced.
[0023]
The method for 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 welding metal 5 to some extent accurately in the filling step. .
[0024]
(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 an effect of preventing the flow path 2 from being blocked at the repair location can be obtained. Also, the height of the projection 9 is not limited to be substantially the same as the length from the surface of the plate-shaped 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.
[0025]
(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 loosely fits into the groove 7 has a similar shape to complement the groove 7. Although it is preferable in terms of processing of the groove 7 that the groove is provided, the shape is not limited to the case where the groove is provided, and any shape can be adopted as long as the cover plate 8 can be attached.
[0026]
(4) Further, the term "crack-occurring portion" used in this specification does not refer only to a portion where a crack has actually been confirmed visually, but may possibly occur. It is needless to say that it includes a high part and a part which is likely to be generated by the metal structure inspection.
[0027]
【The invention's effect】
According to the repair method described in claim 1, first, a groove is formed in a crack generating portion of the plate-like body by a groove forming step, and then the bottom of the groove is filled with a weld metal by a filling step, and thereafter, By attaching a lid plate to the opening on the surface of the plate-shaped body in the lid mounting step, repair of cracks generated in the plate-shaped 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, the working fluid is allowed to flow through the flow path of the plate-like body to lower various functions such as cooling. Can be prevented. For example, if 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 unlike the conventional repair method, the repair cost can be reduced.
[0028]
According to the second aspect of the present invention, after the filling step, there is a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow path in the groove, so that the bottom is welded. A groove having substantially the same depth as the bottom of the flow channel is formed in the groove filled with metal, so that the bottom of the flow channel of the plate-like body and the bottom of the hollow portion formed at the repair location can be made substantially coincident with each other. As a result, it is possible to promote the streamline of the working fluid flowing through the flow path at the repair location. Further, even if the weld metal overlaps the groove surface opening of the flow channel by welding to the groove bottom in the filling step, the overlapping 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.
[0029]
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. The function of such a product (for example, the flow of combustion gas) in a product using a plate having a flow path (for example, a transition piece of a gas turbine combustor) using the plate-shaped body having a flow path whose bottom surface is flushed by the smoothing process. Etc.) can be prevented.
[0030]
Further, as in the present invention as set forth in claim 4, when the lid plate used in the lid attaching step is provided with a convex portion that can be inserted into an opening of the plate-like body surface, this convex portion is formed on the plate-like body surface. By attaching a cover plate so as to be inserted into the opening, the space above the hollow portion formed at the repair location is reduced, and the difference between the cross-sectional shape of this hollow portion and the cross-sectional shape of the flow path of the plate-like body is reduced. It is possible to reduce the increase in pressure loss due to the above. Further, 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.
[0031]
As in the present invention as set forth in claim 5, a lid 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 this lid is used as an opening in the surface of the plate. By being attached, 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 hollow portion of the flow path and the repair location Streamline of the working fluid flowing through the fluid can be further promoted.
[0032]
Further, since the cover plate and the plate-like body are made of the same material as in the present invention as set forth in claim 6, the expansion coefficients of the plate-like body and the cover plate can be made equal to each other. It is possible to prevent the lid plate from falling off or being damaged during the cycle.
[Brief description of the drawings]
FIGS. 1A to 1F are cross-sectional views of a plate-like body for explaining a plate-like body repairing method according to an embodiment of the present invention. In addition, the cut surface of each 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 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 where 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)

A method for repairing a plate-like body having a channel therein,
A groove forming step of forming a groove for welding by removing a crack occurrence portion of the plate-like body,
A filling step of filling the bottom of the groove by welding,
A step of attaching a lid plate to an opening of the groove that opens on the surface of the plate-like body. The repair method according to claim 1, further comprising a groove forming step of engraving a groove having substantially the same depth as the bottom of the flow channel in the groove after the filling step. The repair method according to claim 1 or 2, further comprising a bottom surface smoothing step of removing a weld metal projecting from a bottom surface of the plate-like body by welding to the groove after the filling step. The repair method according to any one of claims 1 to 3, wherein the lid plate used in the lid attaching step includes a convex portion that can be inserted into the opening that opens on the surface of the plate-shaped body. The repair method according to claim 4, wherein the height of the convex portion is substantially the same as the length from the surface of the plate-shaped body to the top of the flow path. The repair method according to any one of claims 1 to 5, wherein the same material as the plate is used as the material of the lid plate.

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