JP5357986B2 - Method of water cooling inside nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a plug for cooling the inside surface of a nozzle neck with water, by which an inside surface of the nozzle neck and piping can be locally filled with water. <P>SOLUTION: In the method for cooling the inside surface of the nozzle neck with water, including cooling the inside surface of the nozzle neck 12 located to the top portion of a vessel 10 and the inside surface of the piping 14 connected to the nozzle neck 12, a plug 16 is configured to include a balloon 33 inserted to the inside surface of the nozzle neck 12 and expanded by supply of air into a portion between two disks 30, 31, a spacer 32 for securing the interval between the two disks 30, 31 and an air supply hose 34 for supplying air to the balloon, the balloon 33 being swollen in the inside surface of the nozzle neck by the supply of the air from the air supply hose 34. The plug 16 is connected with a water supply hose 18 for supplying water 17 to the inside of the nozzle neck 12 and the piping 14, and a water recovery hose 19 for discharging the water 17 from the inside of the nozzle neck 12 and the piping 14, and the temperature of the water 17 is controlled to locally cool the inside of the nozzle neck 12 and the piping 14. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a nozzle inner surface water cooling method.

  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. 5 is a view showing the structure of the container with the nozzles located at the upper part. As shown in FIG. 5, the nozzle 71 is connected to the system by a normal pipe 72. If the inner surface of the nozzle 71 is to be water-cooled, 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, in the nozzle 71 attached to the upper part of the container 70 as shown in FIG.
In view of the above, an object of the present invention is to provide a nozzle inner surface water cooling method capable of locally filling the nozzle and the pipe inner surface with water.

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 balloon member that is inflated by supplying air between two discs is sandwiched between the inner surface of the nozzle, and a spacer that fixes a distance between the two discs is supplied, and air is supplied to the balloon member. An air supply hose is installed, and by supplying air from the air supply hose, the balloon material is stoppered so as to protrude from the inner surface of the nozzle, and water is supplied to the stopper and the pipe. A water supply hose to be supplied and a water recovery hose for draining water from the inside of the nozzle and the pipe are connected, and the nozzle and the pipe outer surface heated from the nozzle and the pipe outer surface are heated to improve residual stress. The temperature of the pipe inner surface is set to 100. As a range up to minimum position which does not rise above filled with the water, a tube for keeping the water level constant in the plug-side tip of the water return hose installed, said adjusting the temperature of the water The nozzle and the pipe inner surface are locally cooled.
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. Moreover, the plug can be easily installed on the inner surface of the nozzle or removed from the inner surface of the nozzle by simply operating the valve. 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 a second aspect of the present invention for solving the above-mentioned problem is the nozzle inner surface water cooling method according to the first invention, wherein when there is an opening on the upper side of the nozzle base, instead of the stopper. A balloon that is inflated by supplying air from the opening is inserted, and the inner surface of the nozzle is plugged by the balloon.
Accordingly, the balloon can be installed on the inner surface of the nozzle base at the top of the container without any work in the container.

  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.

It is the figure which showed the nozzle inner surface water cooling method which concerns on the 1st Embodiment of this invention. It is the figure which showed the structure of the stopper in the nozzle inner surface water cooling method which concerns on the 1st Embodiment of this invention. It is the figure which showed the nozzle inner surface water cooling method which concerns on the 2nd Embodiment of this invention. It is the figure which showed the nozzle inner surface water cooling method which concerns on the 3rd Embodiment of this invention. It is the figure which showed the structure of the container in which a nozzle is located in the upper part.

  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 diagram illustrating a nozzle inner surface water cooling method according to the first embodiment of the present invention, and FIG. 2 illustrates a stopper structure in the nozzle inner surface water cooling method according to the first embodiment of the present invention. FIGS. 3 and 3 are views showing a nozzle inner surface water cooling method according to the second embodiment of the present invention, and FIG. 4 is a diagram showing a nozzle nozzle inner surface water cooling method according to the third 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. In order to prevent the water on the inner surface of the nozzle from excessively rising due to the heat at the time of laser irradiation, it is possible to replace the supply of water inside. Then, as an easy installation method of the stopper, the balloon material is sandwiched between two discs fixed at a distance by a spacer, and air is supplied to the balloon material, so that the balloon material projects over the inner surface of the nozzle, and water is discharged. It is a stopper for storing.

  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.

  Further, as shown in FIG. 2, the stopper 16 according to the present embodiment prepares two discs 30 and 31 having a diameter smaller than the inner diameter of the nozzle 12, and the two discs 30 and 31. The spacer 32 which fixes a space | interval 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 that can switch 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. In FIG. 2, the water supply hose 18 and the water recovery hose 19 are not shown, but the water supply hose 18 and the water recovery hose 19 are actually installed as in FIG.

  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. Further, 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 by only operating the valve 35.

[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 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. 3, 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.

[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, 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. 4, 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.

  The present invention can be applied, for example, to a nozzle inner surface water cooling method in a laser irradiation residual stress improvement method for a pressurizer nozzle of a nuclear power plant.

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 collection hose 30, 31 Disc 32 Spacer 33 Balloon material 34, 52 Air supply hose 35, 53 Valve 40 Pipe 50 Valve 51 Balloon

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,
A balloon member that swells by supplying air between two discs is sandwiched between the inner surface of the nozzle and a spacer that fixes the interval between the two discs, and an air supply hose that supplies air to the balloon member And plugging the balloon material so that the balloon material projects over the inner surface of the nozzle by supplying air from the air supply hose,
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. Install a pipe to keep the water level constant at the end of the water recovery hose on the stopper side,
The nozzle inner surface water-cooling method characterized by locally cooling the nozzle stub and the pipe inner surface by adjusting the temperature of the water. In the nozzle inner surface water cooling method according to claim 1 ,
When there is an opening on the upper side of the nozzle, instead of the stopper, a balloon that is inflated by supplying air from the opening is inserted, and the inner surface of the nozzle is plugged with the balloon Internal water cooling method.

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