JP5203653B2 - Method of water cooling inside nozzle - Google Patents

Description

The present invention relates to a nozzle stub inner surface water-cooling how.

  When there is a tensile residual stress on the inner surface of the pipe or the welded portion around the nozzle base, stress corrosion cracking (SCC) may occur depending on the material and the internal water environment. As a countermeasure, a laser irradiation residual stress improvement method is known in which a laser is irradiated on the outer surface of the nozzle and the tensile residual stress on the inner surface is improved to the compression side due to a composition strain caused by a temperature difference between the outer surface and the inner surface.

  In this laser irradiation residual stress improvement method, when the laser output is performed under a condition where the laser output is high, a temperature difference between the outer surface and the inner surface can be secured, so that an effect of improving the stress can be obtained. On the other hand, by cooling the inner surface with water, it is possible to select a condition for reducing the laser output by preventing the temperature of the inner surface from rising above the boiling point of water.

  FIG. 7 is a view showing the structure of the container with the nozzles located in the upper part. As shown in FIG. 7, the nozzle 71 is connected to the system by a normal pipe 72. If the inner surface of the nozzle 71 is to be cooled with water, the inner surface of the pipe 72 needs to be filled with water 74. For this reason, a method is conceivable in which the pipe 72 is plugged and only the nozzle base weld 73 is filled with water. Although the method for filling the pipe 72 with the water 74 and cooling it with water is not mentioned, an example of a method for plugging the pipe 72 with a wind-wire-shaped partition wall is disclosed in the following Patent Document 1.

Japanese Patent Laid-Open No. 10-24367

However, with the nozzle 71 attached to the upper part of the container 70 as shown in FIG. 7, it may be difficult to fill the water 74 only in the local portions on the inner surface of the nozzle 71 and the pipe 72.
From the above, the present invention aims at providing a locally nozzle stub and the nozzle inner surface water-cooling how that can be filled with water in the pipe inner surface.

A nozzle inner surface water cooling method according to a first aspect of the present invention for solving the above-described problems is a nozzle inner surface water cooling for cooling an inner surface of a nozzle located at an upper portion of a container and an inner surface of a pipe connected to the nozzle. In the method, a sealing material having elasticity is sandwiched between two discs on the inner surface of the nozzle, a bolt for adjusting a distance between the two discs is installed, and the two plates are tightened. A water supply hose configured to reduce the distance between the discs so that the sealing material protrudes from the inner surface of the nozzle, and supplies water to the nozzle and the pipe. Connect the water recovery hose that drains water from the pedestal and the inside of the pipe, and heat the pipe pedestal and the pipe outer surface from the laser irradiation position to improve residual stress. The range up to the minimum position where the To be filled, that the water level at the tip of the plug side of the water collection hose placed a tube to maintain a constant, locally cooling the nozzle stub and the pipe inner surface by adjusting the temperature of the water Features.
Therefore, even when it is difficult to fill the nozzle and the pipe with the water because it is attached to the upper part of the container, the laser irradiation residue remains while cooling the nozzle and the pipe inner surface with the water. The stress improvement method can be applied. Further, the stopper can be easily installed from the inner surface of the nozzle by simply tightening the bolt, and the stopper can be easily removed from the inner surface of the nozzle by simply loosening the bolt. Moreover, by confirming that water is discharged from the water recovery hose, it is understood that the water is filled up to the water level protruding from the pipe. Further, since the water heated by the laser irradiation convects and moves above the inner surface of the nozzle, warm water can be drained preferentially from the water recovery hose.

The nozzle inner surface water cooling method according to the second invention for solving the above-mentioned problems is the nozzle inner surface water cooling method according to the first invention, wherein the stopper mounting rod for attaching the stopper to the inner surface of the nozzle base; A flexible shaft for rotating the bolt is prepared, the stopper is disposed on the inner surface of the nozzle by the stopper mounting rod, and the bolt is tightened by the flexible shaft.
Therefore, the stopper can be easily attached from the outside of the container even under conditions where it is difficult for a person to enter the container (high temperature, high radiation, high place, etc.).

  According to the present invention, the nozzle and the pipe inner surface can be locally cooled with water without filling the entire inner surface of the container and the pipe with water.

  Various embodiments of the nozzle inner surface water cooling method according to the present invention will be described with reference to FIGS. FIG. 1 is a view showing a nozzle inner surface water cooling method according to the first embodiment of the present invention, and FIG. 2 shows a stopper structure in the nozzle inner surface water cooling method according to the second embodiment of the present invention. FIG. 3 is a view showing the structure of a plug in a nozzle inner surface water cooling method according to a third embodiment of the present invention, and FIG. 4 shows a nozzle inner surface water cooling method according to a fourth embodiment of the present invention. FIG. 5 is a view showing a nozzle inner surface water cooling method according to the fifth embodiment of the present invention, and FIG. 6 is a view showing a nozzle inner surface water cooling method according to the sixth embodiment of the present invention.

[First Embodiment]
Hereinafter, a first embodiment of a nozzle inner surface water cooling method according to the present invention will be described. In the nozzle inner surface water cooling method according to the present embodiment, when the container has an opening through which a person such as a manhole can enter and exit, a stopper is installed on the inner surface of the nozzle mounting part, and a water supply hose and a drain hose are connected to the stopper. Is attached so that the water on the inner surface of the nozzle does not rise excessively due to the heat at the time of laser irradiation.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. As shown in FIG. 1, there is an opening 11 in the upper part of the container 10, and this opening 11 is formed with a cylindrical protrusion upward. This protrusion is referred to as a nozzle 12. The container 10 is formed with a manhole 13 through which people can enter and exit. A cylindrical pipe 14 is disposed above the container 10, and the lower end portion of the pipe 14 is joined to the upper end portion of the nozzle 12, and the joined portion is joined by circumferential welding. This circumferentially welded portion is referred to as a circumferential welded portion 15.

  In the present embodiment, a stopper 16 is provided in the opening 11 at the top of the container 10, a water supply hose 18 for supplying water 17 into the nozzle 12 and the pipe 14 to the stopper 16, and water 17 in the nozzle 12 and the pipe 17. A water recovery hose 19 for discharging water is attached. And when irradiating a laser to the circumference welding part 15, the water 17 is supplied in the nozzle 12 and the piping 14 from the water supply hose 18, and the inner surface of the nozzle 12 and the piping 14 is cooled locally. Further, the warm water is discharged from the water recovery hose 19 and cold water is supplied from the water supply hose 18 so that the temperature of the water 17 is adjusted so as not to rise too much.

  As described above, according to the present embodiment, since it is attached to the upper part of the container 10, even when it is difficult to locally fill the water 17 in the nozzle 12 and the pipe 14, The laser irradiation residual stress improving method can be applied while locally cooling the inner surface of the pipe 14 with water 17.

[Second Embodiment]
Hereinafter, a second embodiment of the nozzle inner surface water cooling method according to the present invention will be described. The nozzle inner surface water cooling method according to the present embodiment is a method for easily installing a stopper in the first embodiment, in which a sealing material having elasticity (polyurethane or the like) is sandwiched between two discs and tightened with bolts to form a circle. By reducing the distance between the plates, the sealing material projects over the inner surface of the nozzle and serves as a stopper for collecting water.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. In addition, since structures other than a stopper, such as a container and piping, are the same as those in the first embodiment, a description thereof is omitted here. As shown in FIG. 2, the stopper 16 according to the present embodiment prepares two disks 20, 21 having a diameter smaller than the inner diameter of the nozzle 12, and between the two disks 20, 21. A sealing material 22 having elasticity is sandwiched. The upper and lower disks 20 and 21 have a hole in the center, and a bolt 23 is inserted into the hole from below.

  A nut 24 is welded to the upper disk 20 at a position corresponding to the bolt 23, and the bolt 23 is screwed to the nut 24. When the bolt 23 is tightened, the sealing material 22 protrudes from the inner surface of the nozzle 12 and the diameter increases. In FIG. 2, the water supply hose 18 and the water recovery hose 19 are not shown, but actually, the water supply hose 18 and the water recovery hose 19 are installed as in the first embodiment.

  As described above, according to the present embodiment, it is possible to easily install the plug 16 from the inner surface of the nozzle 12 just by tightening the bolt 23, and from the inner surface of the nozzle 12 only by loosening the bolt 23. The plug can be easily removed.

[Third Embodiment]
Hereinafter, a third embodiment of the nozzle inner surface water cooling method according to the present invention will be described. In the nozzle inner surface water cooling method according to the present embodiment, as an easy installation method of the stopper in the first embodiment, the balloon material is sandwiched between two discs fixed at a distance by a spacer, and air is supplied to the balloon material. By supplying, the balloon material protrudes from the inner surface of the nozzle and becomes a stopper for collecting water.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. In addition, since structures other than a stopper, such as a container and piping, are the same as those in the first embodiment, a description thereof is omitted here. As shown in FIG. 3, the stopper 16 according to the present embodiment prepares two disks 30 and 31 having a diameter smaller than the inner diameter of the nozzle 12, and sets an interval between the two disks 30 and 31. The spacer 32 to be fixed is welded.

  Between the two discs 30 and 31, a balloon member 33 that is inflated by supplying air is sandwiched. An air supply hose 34 for supplying air is connected to the balloon material 33. The air supply hose 34 is provided with a valve 35 capable of switching between an air supply state for supplying air to the balloon member 33 and an air discharge state for discharging air from the balloon member 33.

When the valve 35 is in an air supply state, air is supplied into the balloon member 33, and the balloon member 33 projects over the inner surface of the nozzle 12 so that the diameter increases. Return to the original diameter. Although illustration of the water supply hose 18 and the water recovery hose 19 is omitted in FIG. 3, the water supply hose 18 and the water recovery hose 19 are actually installed as in the first embodiment.
As described above, according to this embodiment, the stopper 16 can be easily installed on the inner surface of the nozzle 12 or removed from the inner surface of the nozzle 12 only by operating the valve 35.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the nozzle inner surface water cooling method according to the present invention will be described. The nozzle inner surface water cooling method according to the present embodiment is the nozzle inner surface water cooling method according to the first embodiment. Further, the tube protrudes from the water recovery hose to the nozzle inner surface, and the protruding length of the tube is determined by the nozzle and The water level on the inner surface of the pipe is required up to the water level that is necessary. It is characterized by becoming.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. In addition, since structures, such as a container and piping other than the pipe | tube installed in a water collection | recovery hose, are the same as that of 1st Embodiment, description here is abbreviate | omitted.

  In the present embodiment, it is necessary for the nozzle 12 and the inner surface of the pipe 14 to be filled with water in order to suppress the temperature rise of the inner surface of the welded portion. However, it cannot be confirmed from the outer surface of the nozzle 12 and the pipe 14 that water is filled in a desired water level in the nozzle 12 and the pipe 14. For this reason, as shown in FIG. 4, in this embodiment, a pipe 40 is attached to the tip of the water recovery hose 19. By this pipe 40, the water level of the water 17 inside the nozzle 12 and the pipe 14 is always kept constant. As shown by A, the water level is at least the heating range of the outer surface of the nozzle 12 and the pipe 14 heated by the laser irradiation indicated by B, and the inner surface of the nozzle 12 and the pipe 14 reaches a minimum of 100 ° C. Try to be in range.

  As described above, according to the nozzle inner surface water cooling method according to the present embodiment, the water 17 is filled up to the water level protruding from the pipe 40 by confirming that water is discharged from the water recovery hose 19. I understand that. Further, since the water heated by the laser irradiation moves convectively upward in the nozzle 12 and the pipe 14, the warm water can be drained preferentially from the water recovery hose 19.

[Fifth Embodiment]
Hereinafter, a fifth embodiment of the nozzle inner surface water cooling method according to the present invention will be described. In the nozzle inner surface water cooling method according to the present embodiment, when an opening such as a valve is present on the upper side of the nozzle and this opening can be used, a balloon is inserted into the inner surface of the root of the nozzle base from the opening and air is supplied. It is characterized by having a stopper.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. As shown in FIG. 5, there is an opening 11 in the upper part of the container 10, and this opening 11 is formed with a cylindrical protrusion upward. This protrusion is referred to as a nozzle 12. A cylindrical pipe 14 is disposed above the container 10, and the lower end portion of the pipe 14 is joined to the upper end portion of the nozzle 12, and the joined portion is joined by circumferential welding. This circumferentially welded portion is referred to as a circumferential welded portion 15. In addition, a valve 50 that is an opening is formed in the upper part of the pipe 14.

  In the present embodiment, the balloon 51 is inserted from the valve 50 into the pipe 14 and the nozzle 12. An air supply hose 52 for supplying air is connected to the balloon 51. The air supply hose 52 is provided with a valve 53 capable of switching between an air supply state for supplying air to the balloon 51 and an air discharge state for discharging air from the balloon 51.

  When the valve 53 is in the air supply state, air is supplied into the balloon 51 and the balloon 51 protrudes from the inner surface of the nozzle 12 to increase the diameter. By setting the air discharge state, the balloon 51 returns to the original state. The diameter is also restored. Air is supplied to the balloon 51 in the opening 11 at the top of the container 10 to be inflated, and a plug is placed near the opening 11 at the top of the container 10.

In addition, it is necessary to measure the distance to the installation position of the balloon 51 and the length in the pipe 14 of the air supply hose 52 when the balloon 51 is installed so that the balloon 51 is installed at a predetermined position. . It is also possible to reliably install the balloon 51 at a predetermined position by confirming whether the balloon 51 is correctly installed at a predetermined position using an optical fiber or the like.
As described above, according to the present embodiment, the balloon 51 can be installed in the opening 11 in the upper part of the container 10 without any work in the container 10.

[Sixth Embodiment]
Hereinafter, a sixth embodiment of the nozzle inner surface water cooling method according to the present invention will be described. The nozzle inner surface water cooling method according to the present embodiment is the same as the nozzle inner surface water cooling method according to the second embodiment, in which a stopper is installed from the outside of the manhole without entering the container, and the stopper main body is a nozzle nozzle The bolt is attached to the installation position, and the bolt is rotated from the outside of the manhole using a flexible shaft.

  Next, the nozzle inner surface water cooling method according to the present embodiment will be described. In addition, since the structures of the container, the piping, the stopper, and the like are the same as those in the second embodiment, description thereof is omitted here. As shown in FIG. 6A, a stopper is attached to the tip of a stopper attachment rod 60 having an angle adjusting mechanism 61. The stopper 16 can be easily installed by adjusting the bending degree of the angle adjusting mechanism 61.

  Further, as shown in FIG. 6B, the bolt holding part 63 of the flexible shaft 62 is attached to the bolt 23. A handle 64 is attached to the end of the flexible shaft 62 opposite to the bolt gripping portion 63, and the bolt 23 can be rotated by turning the handle 64.

Then, after the stopper 16 is positioned in the opening 11 at the upper part of the container 10 by the stopper attachment rod 60, the handle 64 of the flexible shaft 64 is turned in the direction in which the bolt 23 is tightened. .
As described above, according to the present embodiment, the stopper 16 can be easily attached from the outside of the container 10 even under conditions where it is difficult for a person to enter the container 10 (high temperature, high radiation, high place, etc.).

The present invention is, for example, can be applied to the nozzle inner surface water-cooling how the pressurizer nozzle stub laser irradiation residual stress improving method of the nuclear power plant.

The figure which showed the nozzle inner surface water cooling method which concerns on the 1st Embodiment of this invention The figure which showed the structure of the stopper in the nozzle inner surface water cooling method which concerns on the 2nd Embodiment of this invention. The figure which showed the structure of the stopper in the nozzle inner surface water cooling method which concerns on the 3rd Embodiment of this invention. The figure which showed the nozzle inner surface water cooling method which concerns on the 4th Embodiment of this invention. The figure which showed the nozzle inner surface water cooling method which concerns on the 5th Embodiment of this invention The figure which showed the nozzle inner surface water cooling method which concerns on the 6th Embodiment of this invention The figure which showed the structure of the container where the nozzle is located in the upper part

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Container 11 Opening 12 Tubular base 13 Manhole 14 Piping 15 Circumferential welding part 16 Plug 17 Water 18 Water supply hose 19 Water recovery hose 20, 21, 30, 31 Disc 22 Sealing material 23 Bolt 24 Nut 32 Spacer 33 Balloon material 34, 52 Air supply hose 35, 53 Valve 40 Pipe 50 Valve 51 Balloon 60 Plug mounting rod 61 Angle adjustment mechanism 62 Flexible shaft 63 Bolt gripping part 64 Handle

Claims (2)

In the nozzle inner surface water cooling method for cooling the inner surface of the nozzle located at the upper part of the container and the inner surface of the pipe connected to the nozzle,
On the inner surface of the nozzle, a sealing material having elasticity is sandwiched between two disks, a bolt for adjusting the interval between the two disks is installed, and the two disks are tightened by tightening the bolts. The stopper is configured so that the sealing material projects to the inner surface of the nozzle by reducing the distance of
A water supply hose that supplies water to the nozzle and the pipe inside the stopper, and a water recovery hose that drains water from the nozzle and the pipe inside,
A range from the laser irradiation position of the nozzle and the outer surface of the pipe that is heated to improve residual stress to the minimum position where the temperature of the inner surface of the nozzle and the inner surface of the pipe is not raised to 100 ° C. or more is filled with the water. , a tube for keeping the water level constant in the plug-side tip of the water return hose installed,
The nozzle inner surface water cooling method characterized by adjusting the temperature of the water to locally cool the nozzle and the inner surface of the pipe. In the nozzle inner surface water cooling method according to claim 1,
A plug mounting rod for mounting the plug to the inner surface of the nozzle and a flexible shaft for rotating the bolt are prepared,
The plug inner surface water-cooling method, wherein the stopper is disposed on the inner surface of the nozzle by the stopper mounting rod, and the bolt is tightened by the flexible shaft.

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