JP2012215339A - Tool and method for repairing seal welding of heat transfer pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repairing tool that can apply a repair welding to a seal welding part of a heat transfer pipe without causing an increase in inner pressure, thereby not causing a blowoff, and to provide a repairing method.SOLUTION: The tool 13 for repairing a seal welding part of a heat transfer pipe, joints a pipe plate 2 constituting a steam generator to the heat transfer pipe 7 mounted into a pipe hole 9 of the pipe plate 2. The tool includes: a tubular part 14 having a hollow cylindrical shape with an external diameter smaller than an inner diameter of the heat transfer pipe 9; and a flange 15 protruding radially outward from one end of the tubular part 14 while formed along a circumferential direction of the tubular part, and having an external diameter larger than that of the heat transfer pipe 7.

Description

  The present invention relates to repair of a heat transfer tube seal weld that joins a tube plate constituting a steam generator and a heat transfer tube mounted in a tube hole of the tube plate.

  As a steam generator, for example, a reactor steam generator disclosed in Patent Document 1 is known.

JP 2008-25918 A

Further, as shown in FIG. 13, in the reactor steam generator disclosed in Patent Document 1, the tube plate 2 and the heat transfer tube 7 mounted in the tube hole 9 of the tube plate 2 are connected to each other. It joins via the heat pipe seal welding part 19, and comprises the boundary between a primary system and a secondary system.
In the event that a defect such as a crack due to stress corrosion cracking has occurred in the heat transfer tube seal welded portion 19 constituting the boundary between the primary system and the secondary system, it is necessary to carry out repair welding. Arise. As one of the repair methods, a method of repairing by performing partial overlay welding after removing the defect is conceivable.

  However, when partial build-up welding is performed, heating is performed in a state where a small gap between the heat transfer tube and the tube sheet is sealed, so that the internal pressure may increase and ejection may occur during welding.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a repair tool and a repair method that can repair and weld a heat transfer tube seal welded portion without causing an increase in internal pressure and without generating an ejection. And

The present invention employs the following means in order to solve the above problems.
A repair tool for a heat transfer tube seal welded portion according to the first aspect of the present invention is a heat transfer tube seal welded portion that joins a tube plate constituting a steam generator and a heat transfer tube mounted in a tube hole of the tube plate. A hollow cylindrical tubular portion having an outer diameter smaller than the inner diameter of the heat transfer tube, and projecting radially outward from one end of the tubular portion, and along the circumferential direction And a flange portion having an outer diameter larger than the outer diameter of the heat transfer tube.

According to the repair tool for a heat transfer tube seal weld according to the first aspect of the present invention, for example, as shown in FIG. 2 or FIG. 3, the heat transfer tube seal weld having a defect such as a crack is completely removed. Then, a new seal welded portion 27 is formed on the surface 23 of the tube plate 2 located radially outward from the tube hole 9, whereby one (one side) between the primary system and the secondary system. Formed as a boundary.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 28 of the tubular portion 14 that becomes the other (other side) boundary has a gap A between the heat transfer tube 7 and the outer peripheral surface 28. Since it is in a closed state and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, it is expanded so that the outer peripheral surface 28 of the cylindrical part (sleeve part) 14 and the inner peripheral surface 29 of the heat exchanger tube 7 may closely_contact | adhere. By doing so, the boundary between the primary system and the secondary system is completed by making the mechanical seal portion effective.

  The repair tool for the heat transfer tube seal welded portion according to the second aspect of the present invention is a heat transfer tube seal welded portion that joins the tube plate constituting the steam generator and the heat transfer tube mounted in the tube hole of the tube plate. A tubular portion having an outer diameter smaller than the inner diameter of the heat transfer tube and having one end portion closed by a closed portion, and projecting radially outward from one end portion of the tubular portion. And a flange portion formed along the circumferential direction and having an outer diameter larger than the outer diameter of the heat transfer tube.

According to the repair tool for a heat transfer tube seal weld according to the second aspect of the present invention, for example, as shown in FIG. 6 or FIG. 7, the heat transfer tube seal weld 19 having a defect such as a crack is completely formed. As a new seal welded portion 27 is formed on the surface 23 of the tube plate 2 located radially outward from the tube hole 9, one boundary between the primary system and the secondary system is obtained. It is formed.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 47 of the tubular portion (sleeve portion) 45 serving as the other (other side) boundary is between the heat transfer tube 7. Since it has a gap A and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 47 of the cylindrical part (sleeve part) 45 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part (Sleeve portion) The tube is expanded so that the outer peripheral surface 47 of the 45 is in close contact with the inner peripheral surface 29 of the heat transfer tube 7.
Further, as shown in FIG. 8, the end of the heat transfer tube located on the opposite side of the end of the heat transfer tube plugged by the repair tool (blocking plug) is plugged with a mechanical plug 72, thereby providing a primary system. And the boundary between the secondary system is completed.

  In the repair tool for the heat transfer tube seal welded portion, when the inner diameter of the tubular portion and the outer diameter of the collar portion are attached to the heat transfer tube requiring repair of the heat transfer tube seal welded portion, defects are removed. It is more preferable that the dimension is set so as to cover the generated heat transfer tube seal weld.

  According to such a repair tool for the heat transfer tube seal welded part, for example, as shown in FIG. 4 or FIG. 9, the repair work is performed in a state where the heat transfer tube seal welded part 19 in which the defect has occurred is not removed. Therefore, the working efficiency can be improved and the working time can be shortened.

  In the repair tool for the heat transfer tube seal welded portion, it is more preferable that the other end portion of the tubular portion is provided with a mechanical seal portion that protrudes radially outward and is formed along the circumferential direction. It is.

  According to such a repair tool for the heat transfer tube seal welded part, for example, as shown in FIG. 3 or 5, the mechanical seal part 16 bites into and adheres to the inner peripheral surface 29 of the heat transfer tube 7. The sealing performance can be improved, and the boundary between the primary system and the secondary system can be made more reliable.

A repair method for a heat transfer tube seal weld according to the first aspect of the present invention is a repair method for a heat transfer tube seal weld performed using the repair tool for a heat transfer tube seal weld according to claim 1,
The heat transfer tube seal welded part that has caused a defect is removed, and the repair tool for the heat transfer tube seal welded part according to claim 1 or 2 is inserted inside the heat transfer tube, and the inner peripheral surface of the heat transfer tube and the tube A repair tool for the heat transfer tube seal welded portion inserted inside the heat transfer tube after joining the flange portion and the tube plate by welding with a gap between the outer peripheral surface of the tube-shaped portion Is expanded from one end to the other end to form a boundary.
A repair method for a heat transfer tube seal welded portion using the repair tool (blocking plug) for a heat transfer tube seal welded portion according to claim 2, wherein the heat transfer tube seal welded portion is positioned on the opposite side of the end of the heat transfer tube plugged by the repair tool. A boundary between the primary system and the secondary system is completed by plugging the end of the heat transfer tube with the mechanical plug 72.

According to the method for repairing a heat transfer tube seal weld according to the first aspect of the present invention, for example, as shown in FIG. 2 or FIG. 3, the heat transfer tube seal weld having a defect such as a crack is completely removed. Then, a new seal welded portion 27 is formed on the surface 23 of the tube plate 2 located radially outward from the tube hole 9, whereby one (one side) between the primary system and the secondary system. Formed as a boundary.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 28 of the tubular portion 14 that becomes the other (other side) boundary has a gap A between the heat transfer tube 7 and the outer peripheral surface 28. Since it is in a closed state and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
Then, after joining the flange portion 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 28 of the tubular portion (sleeve portion) 14 and the inner peripheral surface 29 of the heat transfer tube 7 are in close contact with each other, The boundary between the primary system and the secondary system is completed by enabling the mechanical seal portion.

Moreover, according to the repair method of the heat exchanger tube seal weld part which concerns on the 2nd aspect of this invention, as shown in FIG. 6 or FIG. 7, the heat exchanger tube seal weld part 19 which produced defects, such as a crack, is shown, for example. It is completely removed, and a new seal weld 27 is formed on the surface 23 of the tube sheet 2 located radially outward from the tube hole 9, so that one of the primary system and the secondary system is provided. Formed as a boundary.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 47 of the tubular portion (sleeve portion) 45 serving as the other (other side) boundary is between the heat transfer tube 7. Since it has a gap A and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 47 of the cylindrical part (sleeve part) 45 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part (Sleeve portion) The tube is expanded so that the outer peripheral surface 47 of the 45 is in close contact with the inner peripheral surface 29 of the heat transfer tube 7.
Further, as shown in FIG. 8, the end of the heat transfer tube located on the side opposite to the end of the heat transfer tube plugged by the repair tool is plugged with a mechanical plug 72, thereby the primary system and the secondary system. The boundary between is completed.

A repair method for a heat transfer tube seal welded portion according to the first aspect of the present invention is a repair method for a heat transfer tube seal welded portion that is performed using the repair tool for a heat transfer tube seal welded portion according to claim 1, The heat transfer tube seal welded part according to claim 1 is inserted inside the heat transfer tube, and the inner peripheral surface of the heat transfer tube and the cylindrical portion are After joining the flange portion and the tube sheet by welding with a gap between the outer peripheral surface and the outer peripheral surface, the repair tool for the heat transfer tube seal welded portion inserted inside the heat transfer tube is The pipe is expanded toward the other end.
A repair method for a heat transfer tube seal welded portion according to a second aspect of the present invention is a repair method for a heat transfer tube seal welded portion that is performed using the repair tool (blocking plug) for the heat transfer tube seal welded portion of claim 2. The end of the heat transfer tube located on the opposite side of the end of the heat transfer tube plugged by the repair tool is plugged with the mechanical plug 72, thereby completing the boundary between the primary system and the secondary system. To do.

According to the method for repairing a heat transfer tube seal weld according to the first aspect of the present invention, for example, as shown in FIG. 4 or FIG. 5, the heat transfer tube seal weld 19 having a defect such as a crack is left as it is. Thus, a new seal welded portion 27 is formed on the surface 23 of the tube plate 2 positioned radially outward from the tube hole 9, thereby forming one boundary between the primary system and the secondary system. Is done.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 28 of the tubular portion 14 that becomes the other (other side) boundary has a gap A between the heat transfer tube 7 and the outer peripheral surface 28. Since it is in a closed state and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
Then, after joining the flange portion 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 28 of the tubular portion (sleeve portion) 14 and the inner peripheral surface 29 of the heat transfer tube 7 are in close contact with each other, The boundary between the primary system and the secondary system is completed by enabling the mechanical seal portion.

Moreover, according to the repair method of the heat exchanger tube seal welded part which concerns on the 2nd aspect of this invention, as shown in FIG. 9 or FIG. 10, the heat exchanger tube seal welded part 19 which produced defects, such as a crack, is shown. As it is, a new seal welded portion 27 is formed on the surface 23 of the tube sheet 2 located radially outward from the tube hole 9 so that one boundary between the primary system and the secondary system is formed. Formed as.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 47 of the tubular portion (sleeve portion) 45 serving as the other (other side) boundary is between the heat transfer tube 7. Since it has a gap A and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 47 of the cylindrical part (sleeve part) 45 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part (Sleeve portion) The tube is expanded so that the outer peripheral surface 47 of the 45 is in close contact with the inner peripheral surface 29 of the heat transfer tube 7.
Furthermore, as shown in FIG. 11, the end of the heat transfer tube located on the side opposite to the end of the heat transfer tube plugged by this repairing tool is plugged with a mechanical plug 72, thereby the primary system and the secondary system. The boundary between is completed.

  In the repair method of the heat transfer tube seal welded part, when the repair tool for the heat transfer tube seal welded part in which one end portion of the cylindrical part is closed by the closed part is used, the tube is plugged by the repair tool of the heat transfer tube seal welded part. A boundary between the primary system and the secondary system is completed by plugging the end of the heat transfer tube located on the side opposite to the end of the heat transfer tube with a mechanical plug.

  According to such a method for repairing a heat transfer tube seal weld, a boundary between the primary system and the secondary system can be formed at both ends (inlet portion and outlet portion) of the heat transfer tube.

  According to the heat transfer tube seal weld repair tool and the heat transfer tube seal weld repair method according to the present invention, it is possible to repair and weld the heat transfer tube seal weld without causing an increase in internal pressure. There is an effect.

It is sectional drawing which shows the whole reactor steam generator provided with the repair tool of the heat exchanger tube seal welding part which concerns on this invention. It is a figure for demonstrating the repair tool of the heat exchanger tube seal weld part which concerns on 1st Embodiment of this invention, and the repair method of a heat exchanger tube seal weld part, Comprising: It is sectional drawing which expands and shows the principal part of FIG. . It is a figure for demonstrating the repair tool of the heat exchanger tube seal weld part which concerns on 1st Embodiment of this invention, and the repair method of a heat exchanger tube seal weld part, Comprising: It is sectional drawing which expands and shows the principal part of FIG. . It is a figure for demonstrating the repair tool and repair method which concern on 2nd Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 2nd Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 3rd Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 3rd Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 3rd Embodiment of this invention, Comprising: It is a figure which shows the plugging state of the other side of an inverted U-shaped heat exchanger tube. It is a figure for demonstrating the repair tool and repair method which concern on 4th Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 4th Embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the repair tool and repair method which concern on 4th Embodiment of this invention, Comprising: It is a figure which shows the plugging state of the other side of an inverted U-shaped heat exchanger tube. It is a figure for demonstrating the repair tool and repair method which concern on other embodiment of this invention, Comprising: It is a figure similar to FIG. It is a figure for demonstrating the conventional repair method, Comprising: It is a figure similar to FIG.

[First Embodiment]
Hereinafter, a repair tool for a heat transfer tube seal weld and a repair method for a heat transfer tube seal weld according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a cross-sectional view showing an entire reactor steam generator 1 equipped with a repair tool for a heat transfer tube seal weld according to the present invention, and FIGS. 2 and 3 repair a heat transfer tube seal weld according to the present embodiment. It is a figure for demonstrating the repair method of a tool and a heat exchanger tube seal welding part, Comprising: It is sectional drawing which expands and shows the principal part of FIG.

A tube plate 2 is provided on the lower side of the reactor steam generator 1, and an inlet water chamber 3 and an outlet water chamber 4 for reactor coolant are formed at the lower end of the tube plate 2. . Further, a barrel 5 is provided on the upper side of the nuclear steam generator 1 so as to surround the circumference. Inside the barrel 5, an encircling tube 6 and a plurality of inverted U-shaped heat transfer tubes (hereinafter, referred to as “reverse U-shaped heat transfer tubes”) are provided. , "Heat transfer tube") 7 is provided. A high-temperature reactor coolant flows through each heat transfer tube 7 to heat the feed water 8 that is a trunk-side fluid and generate steam.
On the other hand, both end portions of each heat transfer tube 7 are respectively inserted into tube holes 9 (see FIG. 2) of the corresponding tube plate 2. Each heat transfer tube 7 is supported in the lateral direction by a plurality of support plates 10 spaced in the vertical direction.

In the reactor steam generator 1 having such a configuration, the high-temperature coolant supplied from the reactor flows into the heat transfer tube 7 through the inlet water chamber 3 and flows through it, and heat is exchanged by heat exchange. After losing and becoming low temperature, it flows to the outlet water chamber 4 and then returns to the reactor.
On the other hand, the feed water 8 that has flowed into the reactor steam generator 1 from the feed water ring 11 flows downward between the surrounding tube 6 and the trunk 5, flows on the tube plate 2, and then flows along the heat transfer tube 7. Flowing upwards. At this time, the feed water 8 exchanges heat with the reactor coolant described above, and a part of the water becomes steam. And when the feed water 8 to be heated flows upward, the steam that has passed through the support plate 10 and separated through the steam-water separation vane 12 flows out.
The tube sheet 2 is made of, for example, a low alloy steel such as SA508, and a Ni-based alloy overlay 20 is applied on the surface thereof. The heat transfer tube 7 is made of, for example, Inconel 600 or Inconel 690.

Now, the repair tool (hereinafter referred to as “repair tool”) 13 for the heat transfer tube seal welded portion according to the present embodiment includes a cylindrical portion (sleeve portion) 14 and a flange portion 15.
The cylindrical portion (sleeve portion) 14 includes a mechanical seal portion 16 at one end portion (the upper end portion in FIG. 2) and requires repair of the heat transfer tube seal welded portion 19 (see FIG. 4 or FIG. 9). It is a hollow cylindrical member that is inserted inside the heat transfer tube 7 (inner peripheral side) and forms a new flow path inside the heat transfer tube 7.

  The mechanical seal portion 16 protrudes radially outward from the outer peripheral surface of the tubular portion (sleeve portion) 14 and is formed along the circumferential direction in a ring shape in plan view, and in a cross sectional view (substantially) equilateral triangle shape. And is provided along the longitudinal direction (vertical direction in FIG. 2) of the cylindrical portion (sleeve portion) 14.

Next, a repair method for the heat transfer tube seal welded portion according to the present embodiment (hereinafter referred to as “repair method”) will be described.
First, as shown in FIG. 2, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is removed (removed), and the outer diameter of the tubular portion (sleeve portion) 14 is larger than the inner diameter of the heat transfer tube 7. The outer diameter of the mechanical seal portion 16 is set slightly smaller (about 0.1 mm to 0.5 mm) and slightly smaller (about 0.1 mm to 0.5 mm) than the inner diameter of the heat transfer tube 7. The repair tool 13 set to become is inserted into the heat transfer tube 7.

Subsequently, the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding. In addition, the code | symbol 27 in FIG. 2 has shown the newly welded part (new seal welding part).
Next, as shown in FIG. 3, the repair tool 13 inserted into the heat transfer tube 7 is moved from one end (lower end in FIG. 3) to the other end (upper end in FIG. 3), for example, a roller-type tube expansion tool. (Not shown) to expand the tube. A roller-type tube expansion tool is a tool in which a satellite roller is mounted around a mandrel having a tapered axis so as to be capable of rotating and revolving, and is inserted into the repairing tool 13 and rotated by applying rotational torque while applying thrust to the mandrel. As the satellite roller rotates and revolves, the expansion force is transmitted and the expansion is performed. As a result, the outer peripheral surface 28 of the tubular portion (sleeve portion) 14 and the inner peripheral surface 29 of the heat transfer tube 7 are in close contact with each other, and the seal portion 16 bites into the inner peripheral surface 29 of the heat transfer tube 7. It is fixed to the heat transfer tube 7.

According to the repair tool 13 and the repair method according to the present embodiment, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is completely removed, and the new seal welded portion 27 is positioned in the radial direction from the tube hole 9. By being formed on the surface 23 of the tube sheet 2 located outside, it is formed as one (one side) boundary between the primary system and the secondary system.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the mechanical seal portion 16 serving as the other (other side) boundary has a gap A between the heat transfer tube 7. Since it is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 28 of the cylindrical part (sleeve part) 14 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part When the mechanical seal portion 16 of the (sleeve portion) 14 bites into and comes into close contact with the inner peripheral surface 29 of the heat transfer tube 7, the boundary between the primary system and the secondary system is completed by making the mechanical seal portion effective.

[Second Embodiment]
A repair tool and a repair method according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 5.
FIG. 4 is a diagram for explaining a repair tool and a repair method according to the present embodiment, and is a view similar to FIG. 2, and FIG. 5 is a diagram for explaining a repair tool and a repair method according to the present embodiment. FIG. 4 is a view similar to FIG.

The repair tool 13 according to the present embodiment is different from that of the first embodiment described above in that the repair is performed while leaving the heat transfer tube seal welded portion 19 in which a defect has occurred. Since other components are the same as those of the first embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

  As shown in FIG. 4, the flange portion 15 according to this embodiment has a heat transfer tube seal that has a defect such as a crack when attached to the heat transfer tube 7 that requires repair of the heat transfer tube seal welded portion 19. It is installed so as to cover (enclose) the welded portion 19.

Next, a repair method according to this embodiment will be described.
First, as shown in FIG. 4, the outer diameter of the cylindrical portion (sleeve portion) 14 is formed to be slightly smaller (about 0.1 mm to 0.5 mm) than the inner diameter of the heat transfer tube 7, and The repair tool 13 formed (set) so that the outer diameter of the mechanical seal portion 16 is slightly smaller (about 0.1 mm to 0.5 mm) than the inner diameter of the heat transfer tube 7 is placed inside the heat transfer tube 7. Insert it.

Subsequently, the flange portion 15 and the tube sheet 2 are joined by welding.
Next, as shown in FIG. 5, the repair tool 13 inserted into the heat transfer tube 7 is moved from one end (lower end in FIG. 5) to the other end (upper end in FIG. 5), for example, a roller-type tube expansion tool. (Not shown) to expand the tube. A roller-type tube expansion tool is a tool in which a satellite roller is mounted around a mandrel having a tapered axis so that it can rotate and revolve. As the satellite roller rotates and revolves, the expansion force is transmitted and the expansion is performed. As a result, the outer peripheral surface 28 of the tubular portion (sleeve portion) 14 and the inner peripheral surface 29 of the heat transfer tube 7 are in close contact with each other, and the seal portion 16 bites into the inner peripheral surface 29 of the heat transfer tube 7. It is fixed to the heat transfer tube 7.

According to the repair tool 13 and the repair method according to the present embodiment, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is completely covered by the flange portion 15, and a new seal welded portion 27 is formed in the tube hole. By being formed on the surface 23 of the tube sheet 2 located on the radially outer side than 9, it is formed as one (one side) boundary between the primary system and the secondary system.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the mechanical seal portion 16 serving as the other (other side) boundary has a gap A between the heat transfer tube 7. Since it is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 28 of the cylindrical part (sleeve part) 14 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part When the mechanical seal portion 16 of the (sleeve portion) 14 bites into and comes into close contact with the inner peripheral surface 29 of the heat transfer tube 7, the boundary between the primary system and the secondary system is completed by making the mechanical seal portion effective.

[Third Embodiment]
A repair tool and a repair method according to a third embodiment of the present invention will be described with reference to FIGS.
FIG. 6 is a view for explaining a repair tool and a repair method according to this embodiment, and is a view similar to FIG. 2. FIG. 7 is a view for explaining a repair tool and a repair method according to this embodiment. FIG. 8 is a view similar to FIG. 3, and FIG. 8 is a view for explaining the repair tool and the repair method according to the present embodiment, and is a view showing a plugging state on the opposite side of the inverted U-shaped heat transfer tube.

The repair tool 43 according to the present embodiment is different from that of the first embodiment described above in that it includes a tubular portion (sleeve portion) 45 and a closing portion 46 instead of the tubular portion (sleeve portion) 14. . Since other components are the same as those of the first embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

  As shown in FIG. 6, a closing portion 46 is provided continuously at one end portion (upper end portion in FIG. 4) of the cylindrical portion (sleeve portion) 45 according to the present embodiment. Further, the repair tool 43 is inserted into the inner side (inner peripheral side) of the heat transfer tube 7 that requires repair of the heat transfer tube seal welded portion 19 to close the flow path formed inside the heat transfer tube 7. It functions as a hollow cylindrical plug.

Next, a repair method according to this embodiment will be described.
First, as shown in FIG. 6, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is removed (removed), and the outer diameter of the tubular portion (sleeve portion) 45 is larger than the inner diameter of the heat transfer tube 7. The repair tool 43 formed (set) to be slightly smaller (about 0.1 mm to 0.5 mm) is inserted inside the heat transfer tube 7.

Subsequently, the flange portion 15 and the tube sheet 2 are joined by welding.
Next, as shown in FIG. 7, the repair tool 43 inserted into the heat transfer tube 7 is moved from one end (the lower end in FIG. 7) to the other end (the upper end in FIG. 7), for example, a roller-type tube expansion tool. (Not shown) to expand the tube. A roller-type tube expansion tool is a tool in which a satellite roller is rotatably and revolved around a mandrel that forms a tapered shaft, inserted into the repair tool 43, and rotated by applying rotational torque while applying thrust to the mandrel. As the satellite roller rotates and revolves, the expansion force is transmitted and the expansion is performed. As a result, the tubular portion (sleeve portion) 45 and the heat transfer tube 7 are in close contact with each other, and the repair tool 43 is fixed to the heat transfer tube 7.

  Here, the repair tool 43 needs to be removed from the service state, unlike the repair tool 13 that can bypass the seal welding portion 19 and put the heat transfer tube 7 into the service state. Therefore, as shown in FIG. 8, the inside of the low-temperature heat transfer tube 7 located on the opposite side of the heat transfer tube 7 is plugged with a mechanical plug 72.

According to the repair tool 43 and the repair method according to the present embodiment, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is completely removed, and the new seal welded portion 27 is positioned in the radial direction from the tube hole 9. By being formed on the surface 23 of the tube sheet 2 located outside, it is formed as one (one side) boundary between the primary system and the secondary system.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 47 of the tubular portion (sleeve portion) 45 serving as the other (other side) boundary is between the heat transfer tube 7. Since it has a gap A and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 47 of the cylindrical part (sleeve part) 45 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part (Sleeve portion) The outer peripheral surface 47 of the 45 is in close contact with the inner peripheral surface 29 of the heat transfer tube 7, and the inside of the low temperature heat transfer tube 7 located on the opposite side of the heat transfer tube 7 is plugged with a mechanical plug 72. The boundary between the primary system and the secondary system is completed.

[Fourth Embodiment]
A repair tool and a repair method according to a fourth embodiment of the present invention will be described with reference to FIGS.
FIG. 9 is a view for explaining a repair tool and a repair method according to this embodiment, and is a view similar to FIG. 2. FIG. 10 is a view for explaining a repair tool and a repair method according to this embodiment. FIG. 11 is a view similar to FIG. 3, and FIG. 11 is a view for explaining the repair tool and the repair method according to the present embodiment, and is a view showing a plugging state on the opposite side of the inverted U-shaped heat transfer tube.

The repair tool 43 according to the present embodiment is different from that of the third embodiment described above in that the repair is performed while leaving the heat transfer tube seal welded portion 19 in which a defect has occurred. Since other components are the same as those of the third embodiment described above, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 3rd Embodiment mentioned above.

  As shown in FIG. 9, the flange portion 15 according to this embodiment has a heat transfer tube seal that has a defect such as a crack when attached to the heat transfer tube 7 that requires repair of the heat transfer tube seal welded portion 19. It is installed so as to cover (enclose) the welded portion 19.

Next, a repair method according to this embodiment will be described.
First, as shown in FIG. 9, the outer diameter of the cylindrical portion (sleeve portion) 14 is formed (set) to be slightly smaller (about 0.1 mm to 0.5 mm) than the inner diameter of the heat transfer tube 7. The repair tool 43 is inserted inside the heat transfer tube 7.

Subsequently, the flange portion 15 and the tube sheet 2 are joined by welding.
Next, as shown in FIG. 10, the repair tool 43 inserted into the heat transfer tube 7 is moved from one end (lower end in FIG. 10) to the other end (upper end in FIG. 10), for example, a roller-type tube expansion tool. (Not shown) to expand the tube. A roller-type tube expansion tool is a tool in which a satellite roller is rotatably and revolved around a mandrel that forms a tapered shaft, inserted into the repair tool 43, and rotated by applying rotational torque while applying thrust to the mandrel. As the satellite roller rotates and revolves, the expansion force is transmitted and the expansion is performed. As a result, the tubular portion (sleeve portion) 45 and the heat transfer tube 7 are in close contact with each other, and the repair tool 43 is fixed to the heat transfer tube 7.
Here, the repair tool 43 needs to be removed from the service state, unlike the repair tool 13 that can bypass the seal welding portion 19 and put the heat transfer tube 7 into the service state. Therefore, as shown in FIG. 11, the inside of the heat transfer tube 7 on the low temperature side located on the opposite side of the heat transfer tube 7 is plugged with a mechanical plug 72.

According to the repair tool 43 and the repair method according to the present embodiment, the heat transfer tube seal welded portion 19 in which a defect such as a crack has occurred is completely covered by the flange portion 15, and a new seal welded portion 27 is formed in the tube hole. By being formed on the surface 23 of the tube sheet 2 located on the radially outer side than 9, it is formed as one (one side) boundary between the primary system and the secondary system.
When the flange portion 15 and the surface 23 of the tube sheet 2 are joined by welding, the outer peripheral surface 47 of the tubular portion (sleeve portion) 45 serving as the other (other side) boundary is between the heat transfer tube 7. Since it has a gap A and is not hermetically sealed, even if heated by welding, the internal pressure does not increase, and repair can be performed without causing ejection.
And after joining the collar part 15 and the surface 23 of the tube sheet 2 by welding, the outer peripheral surface 28 of the cylindrical part (sleeve part) 14 and the inner peripheral surface 29 of the heat exchanger tube 7 contact | connect, and a cylindrical part (Sleeve portion) The outer peripheral surface 47 of the 45 is in close contact with the inner peripheral surface 29 of the heat transfer tube 7, and the inside of the low temperature heat transfer tube 7 located on the opposite side of the heat transfer tube 7 is plugged with a mechanical plug 72. The boundary between the primary system and the secondary system is completed.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.
For example, in the above-described embodiment, the flange portion 15 protrudes (downward) from the surface 23 of the tube plate 2, but the flange portion 15 extends from the surface 23 of the tube plate 2 as shown in FIG. 12. So as not to protrude (downward) from the surface 23 of the tube plate 2, a recess for receiving the flange portion 15 (to which the flange portion 15 fits) is processed, and the surface 23 of the tube plate 2 and the flange portion 15 The surface (lower end surface) may be coplanar.

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Tube plate 3 Inlet water chamber 4 Outlet water chamber 5 Body 6 Surrounding tube 7 Inverted U-shaped heat transfer tube (heat transfer tube)
8 Water supply 9 Pipe hole 10 Support plate 11 Water supply ring 12 Air / water separation vane 13 Repair tool (Repair tool for heat transfer tube seal weld)
14 Cylindrical part (sleeve part)
15 collar 16 mechanical seal 19 heat transfer tube seal weld 23 with defect 23 surface 27 new seal weld 28 outer surface 29 inner surface 43 repair tool (plug)
45 Cylindrical part (sleeve part)
46 Closure 72 Mechanical plug A Clearance

Claims (7)

A repair tool for a heat transfer tube seal weld that joins a tube plate constituting a steam generator and a heat transfer tube mounted in a tube hole of the tube plate,
A hollow cylindrical tubular portion having an outer diameter smaller than the inner diameter of the heat transfer tube, and projecting radially outward from one end of the tubular portion, and formed along a circumferential direction, and A repair tool for a heat transfer tube seal welded portion, comprising: a flange portion having an outer diameter larger than the outer diameter of the heat transfer tube. A repair tool for a heat transfer tube seal weld that joins a tube plate constituting a steam generator and a heat transfer tube mounted in a tube hole of the tube plate,
A cylindrical portion having an outer diameter smaller than the inner diameter of the heat transfer tube, one end portion of which is closed by a closing portion, and projecting radially outward from one end portion of the cylindrical portion, and along the circumferential direction And a flange portion having an outer diameter larger than the outer diameter of the heat transfer tube, and a repair tool for a heat transfer tube seal welded portion.   When the inner diameter of the tubular portion and the outer diameter of the collar portion are attached to the heat transfer tube that requires repair of the heat transfer tube seal welded portion, the heat transfer tube seal welded portion in which a defect has occurred is obscured. The repair tool for the heat transfer tube seal welded portion according to claim 1 or 2, wherein the repairable tool is set to a dimension capable of being adjusted.   2. The heat transfer tube seal according to claim 1, wherein a mechanical seal portion is provided at the other end portion of the cylindrical portion so as to protrude outward in the radial direction and formed along the circumferential direction. Repair tool for welds. A method for repairing a heat transfer tube seal welded portion using the repair tool for a heat transfer tube seal welded portion according to claim 1 or 2,
The heat transfer tube seal welded part that has caused a defect is removed, and the repair tool for the heat transfer tube seal welded part according to claim 1 or 2 is inserted inside the heat transfer tube, and the inner peripheral surface of the heat transfer tube and the tube A repair tool for the heat transfer tube seal welded portion inserted inside the heat transfer tube after joining the flange portion and the tube plate by welding with a gap between the outer peripheral surface of the tube-shaped portion And expanding the tube from one end to the other end to form a boundary. A method for repairing a heat transfer tube seal welded part using the repair tool for a heat transfer tube seal welded part according to claim 3,
The repairing tool for the heat transfer tube seal welded portion according to claim 3 is inserted inside the heat transfer tube, leaving the defective heat transfer tube seal welded portion as it is, and the inner peripheral surface of the heat transfer tube and the tubular portion In a state where there is a gap between the outer peripheral surface of the tube and the flange portion and the tube plate are joined by welding, a repair tool for the heat transfer tube seal welded portion inserted inside the heat transfer tube, A repair method for a heat transfer tube seal weld, wherein a boundary is formed by expanding the tube from one end to the other end.   When using a repairing tool for a heat transfer tube seal welded portion in which one end of the tubular portion is closed by a closing portion, the tube is located on the side opposite to the end of the heat transfer tube plugged by the repair tool for the heat transfer tube seal welded portion. The method for repairing a heat transfer tube seal weld according to claim 5 or 6, wherein the end of the heat transfer tube is plugged with a mechanical plug.

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