JP7724193B2 - Work equipment and work methods - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies. https://www.kepco.co.jp/corporate/pr/2022/pdf/20220513_1j.pdf Regarding the status of the regular inspection of Takahama Nuclear Power Plant Unit 3 (Submission of a nuclear facility failure report regarding damage to the steam generator heat transfer tube) Posted on May 13, 2022

This disclosure relates to work equipment and work methods.

Nuclear power facilities often have steam generators installed. Patent Document 1 shows an inspection device for steam generators. This inspection device inspects the inside of the steam generator by inserting and hanging down an inspection probe through a hand hole provided on the side of the upper part of the steam generator's body.

Japanese Patent Application Laid-Open No. 2021-173468

At this point, foreign matter such as scale may form inside the steam generator. Therefore, when foreign matter does form, it is necessary to take appropriate action, such as removing or collecting the foreign matter from inside the steam generator.

The purpose of this disclosure is to provide work equipment and methods that enable appropriate work to be performed on foreign objects inside a steam generator.

The work equipment disclosed herein is for a steam generator having a heat transfer tube inside a body, and includes: a hollow cable housing that extends axially and can be inserted into a handhole formed in the body; a hollow nozzle that is provided at the tip of the cable housing and has a first opening and a second opening at its tip; a work tool that includes a cable that is inserted into the cable housing and the nozzle, and a working part that is provided at the tip of the cable and exposed from the first opening; and a camera tool that includes a cable that is inserted into the cable housing and the nozzle, and a camera that is provided at the tip of the cable and exposed from the second opening.

The work method disclosed herein is a work method using the work equipment, and includes the steps of inserting the cable housing into the steam generator through the hand hole, advancing the camera of the camera tool out of the nozzle through the second opening of the nozzle, and advancing the working part of the work tool out of the nozzle through the first opening of the nozzle.

This disclosure allows appropriate action to be taken regarding foreign objects inside a steam generator.

FIG. 1 is an explanatory diagram showing the configuration of a steam generator. FIG. 2 is a schematic diagram of a work implement according to an embodiment. FIG. 3 is an explanatory diagram for explaining the work equipment. FIG. 4 is a cross-sectional view of the cable housing. FIG. 5 is an explanatory diagram for explaining the nozzle. FIG. 6 is a schematic diagram of a camera tool. FIG. 7 is a schematic diagram of a retrieval tool. FIG. 8 is a schematic diagram of a cleaning tool. FIG. 9 is a flowchart showing the procedure of the operation method. FIG. 10 is a schematic diagram for explaining the operation method. FIG. 11 is a schematic diagram for explaining the operation method. FIG. 12 is a schematic diagram for explaining the operation method.

Preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, they also include configurations that combine the respective embodiments.

<Steam generator>
FIG. 1 is an explanatory diagram showing the configuration of a steam generator. The steam generator 100 is a heat exchanger used in nuclear power facilities. Primary cooling water heated to a high temperature in the reactor pressure vessel and secondary cooling water flowing on the turbine side flow through the steam generator 100. The steam generator 100 exchanges heat between the primary cooling water and the secondary cooling water, and generates steam by evaporating the secondary cooling water.

The steam generator 100 is arranged vertically and has a body 102. The body 102 has a hollow cylindrical shape. A heat transfer tube group 104 is provided within the body 102. The heat transfer tube group 104 is composed of multiple heat transfer tubes 104A each having an inverted U-shape. The heat transfer tubes 104A are arranged so that the arc portion of the inverted U-shape at the top is convex upward. The lower ends of the heat transfer tubes 104A are supported by a tube plate 106, and their middle portions are supported by the body 102 via multiple tube support plates 108. The tube support plates 108 have multiple through-holes through which the heat transfer tubes 104A are inserted. The tube support plates 108 are arranged at approximately equal intervals vertically. The tube support plates 108 are provided with flow slots 108A through which fluid flowing within the body 102, described below, passes.

The body 102 has a water chamber 110 at its lower end. The water chamber 110 is bowl-shaped, and its interior is divided by a partition plate 112 into an inlet water chamber 114 and an outlet water chamber 116. One end of the heat transfer tube 104A is connected to the inlet water chamber 114, and the other end of the heat transfer tube 104A is connected to the outlet water chamber 116. The inlet water chamber 114 is formed with an inlet nozzle 114A that leads to the outside of the body 102, and the outlet water chamber 116 is formed with an outlet nozzle 116A that leads to the outside of the body 102. The inlet nozzle 114A is connected to a primary cooling water pipe (not shown) from the pressurized water reactor, and the outlet nozzle 116A is connected to a primary cooling water pipe (not shown) that sends heat-exchanged primary cooling water to the pressurized water reactor.

The upper half of the body 102 is provided with a steam-water separator 118 that separates feedwater into steam and hot water, and a moisture separator 120 that removes moisture from the separated steam to produce a state close to dry steam. A water supply pipe 122 is inserted between the steam-water separator 118 and the heat transfer tube bank 104 into the body 102, supplying secondary cooling water from the outside into the body 102. Furthermore, the body 102 has a steam outlet 124 at its upper end. The lower half of the body 102 is also provided with a water supply passage 128 that allows secondary cooling water supplied from the water supply pipe 122 into the body 102 to flow down between the body 102 and the tube bank outer casing 126, turn around at the tube plate 106, and rise along the heat transfer tube bank 104. The steam outlet 124 is connected to a secondary cooling water pipe (not shown) that sends steam to the turbine, and the water supply pipe 122 is connected to a secondary cooling water pipe (not shown) that supplies secondary cooling water that has been cooled in a condenser (not shown) from steam used in the turbine.

The body 102 is provided with hand holes H that connect its interior and exterior. The hand holes H are provided, for example, on the side surfaces of the upper and lower halves of the body 102. In this embodiment, they are provided at the position of the lowest tube support plate 108 and the position of the second-highest tube support plate 108. The hand holes H also penetrate the tube bundle outer casing 126, allowing access to the tube support plates 108 from outside the body 102. Note that when the steam generator 100 is in use, the hand holes H are closed with lids attached. The hand holes H are provided on both sides of the body 102, facing each other and passing through the center of the inverted U-shape of the heat transfer tube 104A.

<Work equipment>
The work equipment 10 according to this embodiment will be described with reference to Fig. 2 to Fig. 6. Fig. 2 is a schematic diagram showing the work equipment according to the embodiment. Fig. 3 is an explanatory diagram for explaining the work equipment. Fig. 4 is a cross-sectional view of a cable housing. Fig. 5 is an explanatory diagram for explaining a nozzle. Fig. 6 is a schematic diagram of a camera tool.

The work equipment 10 has a guide tray 11, a cable housing 12, a nozzle 14, a fixing tool 16, a work tool 30, and a camera tool 60. The work equipment 10 is a device that performs work on foreign matter that has occurred in the steam generator 100. In this embodiment, the foreign matter is scale S containing iron components, and is located on the tube support plate 108. However, the foreign matter targeted by the work equipment 10 is not limited to scale and may be any object. The work equipment 10 uses a collection tool 40 as the work tool 30 to collect the scale S, and uses a cleaning tool 50 as the work tool 30 to wash away the scale S from the tube support plate 108 with cleaning liquid.

(Guide tray)
As shown in Fig. 2, the guide tray 11 is a guide member for guiding the cable housing 12 into the body portion 102. The guide tray 11 is attached to the hand hole H via a guide tray attachment member (not shown). The guide tray 11 extends from the hand hole H toward the inside of the body portion 102. This allows the cable housing 12 to be introduced from the outside to the inside of the body portion 102 along the guide tray 11 through the hand hole H.

The guide tray 11 is configured to guide the cable housing 12, which is the object to be guided, so that it does not shift laterally relative to the insertion direction when it is introduced from the outside to the inside of the body 102. For example, the guide tray 11 has a generally concave cross-sectional shape that corresponds to the outer contour of the cable housing 12 in a cross section perpendicular to the extension direction, thereby preventing the cable housing 12 from shifting laterally relative to the insertion direction.

The tip 11A of the guide tray 11 is open, allowing the cable housing 12 that has been extended to the tip 11A by the guide tray 11 to be exposed from the tip 11A. In this embodiment, the guide tray 11 extends straight from the hand hole H to the vicinity of the tip 11A, with the tip 11A facing downward. As a result, the portion of the cable housing 12 that is exposed from the tip 11A, guided by the guide tray 11, deforms smoothly downward under its own weight.

In this embodiment, the tip 11A is curved downward, which allows the cable housing 12 to deform downward at the tip 11A as it is fed, allowing for smooth deformation without clogging the guide tray 11. This effectively prevents problems such as the cable housing 12 getting stuck near the tip 11A.

The guide tray 11 having the above configuration is configured so that the length from the hand hole H to the tip 11A (insertion length into the body 102) is variable. For example, the guide tray 11 is fixed to the hand hole H via a fixing structure (not shown), but by configuring the fixing position of the guide tray 11 relative to the fixing structure to be variable, the length from the hand hole H to the tip 11A can be changed. Furthermore, if the fixing structure includes a feed mechanism (not shown) for adjusting the insertion depth of the guide tray 11 from the hand hole H, the length from the hand hole H to the tip 11A can be changed by operating the feed mechanism while the guide tray 11 is fixed to the hand hole H.

(cable housing)
As shown in FIGS. 2 to 4 , the cable housing 12 is an axial member extending in the extension direction (axial direction). The cable housing 12 is insertable into a hand hole H and is inserted into the steam generator 100 from the hand hole H. The cable housing 12 can be fed out of the guide tray 11 from a feeding device 13 connected to an end of the guide tray 11 on the outside of the body 102, and is thereby fed out of the hand hole H into the steam generator 100. Specifically, by rotating a handle 13A of the feeding device 13, the cable housing 12 wound around the reel 13B can be fed into the steam generator 100. When the cable housing 12 is inserted into the steam generator 100, the portion exposed from the tip end 11A of the guide tray 11 deforms downward due to its own weight. However, the method of inserting the cable housing 12 into the steam generator 100 from the hand hole H is not limited to this and may be any method. For example, the guide tray 11 and the delivery device 13 are not essential components.

The cable housing 12 is hollow, forming a space inside through which the fixing tool 16, work tool 30, camera tool 60, etc. can be inserted. The cable housing 12 includes segments 12A that are connected to each other along the extension direction of the cable housing 12. The connection angle between adjacent segments 12A is variable, and the cable housing 12 deforms downward due to its own weight. As shown in Figure 4, the cable housing 12 is formed with an insertion hole 12B through which the work tool 30 is inserted, an insertion hole 12C through which the camera tool 60 is inserted, and an insertion hole 12D through which the fixing tool 16 is inserted.

The cable housing 12 is configured to be able to pass through the flow slots 108A provided in each of the tube support plates 108. The tube support plates 108 are provided with multiple flow slots 108A that are open to allow the medium flowing through the body 102 to pass through. The flow slots 108A are elongated openings that run along the arrangement direction of the heat transfer tubes 104A near the heat transfer tubes 104A supported by the tube support plate 108. The cable housing 12 is configured to be smaller than the flow slots 108A, allowing access to the lower part of the body 102 by passing through the flow slots 108A of the multiple tube support plates 108.

(nozzle)
3 and 5 , the nozzle 14 is a hollow member provided at the tip of the cable housing 12. The internal space of the nozzle 14 is in communication with the internal space of the cable housing 12. The nozzle 14 is made of, for example, metal, and guides the work tool 30, camera tool 60, and fixing tool 16 that are inserted through the cable housing 12. In this embodiment, the nozzle 14 is fixed to the tip of the cable housing 12 with a bolt, but any method of fixing the nozzle 14 to the cable housing 12 may be used.

The nozzle 14 has a curved shape extending from the base end 14T1 to the tip end 14T2. In the example shown in FIG. 5, the nozzle 14 extends straight from the base end 14T1 to a midpoint between the base end 14T1 and the tip end 14T2, and then curves relative to the extension direction from the base end 14T1 to the midpoint as it extends from the midpoint to the tip end 14T2. In other words, the central axis of the nozzle 14 extending from the base end 14T1 to the tip end 14T2 includes a curved portion; the central axis of the nozzle 14 is linear from the base end 14T1 to the midpoint, and curved from the midpoint to the tip end 14T2. This curvature of the nozzle 14 allows the work tool 30 and the camera tool 60 to be properly inserted between the heat transfer tubes 104A. However, the shape of the nozzle 14 is not limited to the above description and may be any shape.

The nozzle 14 has a base end 14T1 connected to the tip of the cable housing 12, and a first opening 14A and a second opening 14B formed at the tip end 14T2. As will be described in more detail below, the work tool 30 is extended from the first opening 14A, and the camera tool 60 is extended from the second opening 14B. More specifically, the nozzle 14 has a first space 14A1 and a second space 14B1 formed therein. The first space 14A1 is a space formed within the nozzle 14 that opens to the base end 14T1 side and the tip end 14T2 side. The opening of the first space 14A1 on the tip end 14T2 side forms the first opening 14A. The second space 14B1 is a space formed within the nozzle 14 that opens to the base end 14T1 side and the tip end 14T2 side of the nozzle 14. The opening of the second space 14B1 on the distal end 14T2 side is the second opening 14B. The first space 14A1 and the second space 14B1 are separated by a wall 14D. In this embodiment, when the nozzle 14 is positioned so that the extension direction from the base end 14T1 to the intermediate position faces vertically downward, the first space 14A1 is positioned vertically lower than the second space 14B1 in the curved section from the intermediate position to the distal end 14T2 (the first opening 14A is positioned vertically lower than the second opening 14B). This reduces the degree of curvature of the second space 14B1, making it easier to insert the camera tool 60. In other words, the degree of curvature is the length of the bend relative to the overall length of the nozzle 14. By positioning the second opening 14B vertically higher than the first opening 14A, the second space 14B1 becomes shorter than the first space 14A1. This allows the camera tool 60 to be easily inserted. In this embodiment, the first space 14A1 in which the first opening 14A is formed and the second space 14B1 in which the second opening 14B is formed are isolated within the nozzle 14. However, this is not limited to this, and the space in which the first opening 14A is formed and the space in which the second opening 14B is formed may be a single, unisolated space.

The nozzle 14 also has a third opening 14C. As will be described in more detail below, the fixed tool 16 is drawn out from the third opening 14C. While the third opening 14C may be formed at any position, in this embodiment, it is formed between the base end 14T1 and the tip end 14T2 in the extension direction of the nozzle 14, more specifically, in the curved section between the intermediate position and the tip end 14T2. Furthermore, in this embodiment, the third opening 14C is formed to open vertically downward when the nozzle 14 is positioned so that the extension direction from the base end 14T1 to the intermediate position faces vertically downward. This allows the fixed tool 16 to be drawn vertically downward. In this embodiment, the third opening 14C is connected to the first space 14A1, but this is not a limitation. For example, a third space isolated from the first space 14A1 and the second opening 14B may be formed within the nozzle 14, and the third opening 14C may be connected to this third space. The third opening 14C does not need to be formed, for example, if the fixed tool 16 is not provided.

The nozzle 14 also has a support member 20 formed thereon that supports the fixed tool 16 extending from the third opening 14C. The support member 20 is shaped to protrude outward from the nozzle 14 from near the location where the third opening 14C is formed (for example, within a predetermined distance from the third opening 14C). In this embodiment, the support member 20 extends vertically downward when the nozzle 14 is positioned so that the extension direction from the base end 14T1 to the intermediate position faces vertically downward. However, the support member 20 is not a required component.

(fixed tool)
The fixing tool 16 has a cable that is inserted into the cable housing 12 and the nozzle 14, and a fixing portion that is provided at the tip of the cable, exposed from the third opening 14C, and fixed to the steam generator 100. The fixing tool 16 fixes the position of the nozzle 14 relative to the steam generator 100 by fixing the fixing portion to the steam generator 100. In the present embodiment, as shown in FIG. 3 , the fixing tool 16 includes a balloon 18 as the fixing portion, and a gas supply pipe 22 as the cable.

As shown in FIG. 3, the balloon 18 is made of, for example, a stretchable elastic material (e.g., rubber). The balloon 18 has an opening 18A. When gas is supplied to the interior of the balloon 18 through the opening 18A, the volume of the balloon 18 increases and the balloon expands, and when the gas inside the balloon is discharged through the opening 18A, the volume decreases and the balloon contracts. The shape of the balloon 18 when expanded may be any shape, such as a sphere, a cylinder (column), or a three-dimensional shape such as a rectangular parallelepiped. The gas supplied to the balloon 18 is preferably, for example, air or an inert gas (e.g., nitrogen).

The gas supply pipe 22 is a pipe that conducts gas through its interior. The gas supply pipe 22 is preferably flexible and may be made of, for example, a resin material (e.g., nylon, Teflon (registered trademark), urethane, etc.). The tip of the gas supply pipe 22 is connected to the opening 18A of the balloon 18.

In this embodiment, the gas supply pipe 22 is inserted through the cable housing 12 and the nozzle 14, and the balloon 18, whose tip is provided at the tip of the gas supply pipe 22, is exposed to the outside of the nozzle 14 through the third opening 14C of the nozzle 14. Furthermore, in this embodiment, the portion of the gas supply pipe 22, including its tip, is exposed to the outside of the nozzle 14, and the exposed portion of the gas supply pipe 22 is fixed to the support member 20. The gas supply pipe 22 may be fixed to the support member 20 by any method, but may be fixed, for example, with tape.

(Camera Tool)
As shown in FIGS. 3 and 6 , the camera tool 60 includes a cable 61 and a camera 65 attached to the tip of the cable 61. The camera tool 60 is a so-called endoscope, such as a fiberscope. The camera 65 is an imaging unit capable of capturing images of the external environment and includes an imaging element such as a charge-coupled device (CCD) and an illumination element such as an LED (light-emitting diode). The cable 61 includes a power supply cable for the imaging element and the illumination element, and a signal cable for transmitting an image signal from the imaging element. The cable 61 may also include a bendable distal end and a control wire for controlling the bend. Therefore, the cable 61 may be connected to a control unit 62 at its proximal end for controlling the control wire. The camera tool 60 may also include an image processing unit 63 and a display unit 64. The image processing means 63 is connected to the base end of the cable 61 and supplies power to the imaging element and the lighting element, and processes the image signal from the imaging element as a captured image signal for display. The display means 64 is connected to the image processing means 63 and receives the captured image signal to display the captured image.

In this embodiment, the camera tool 60 has a cable 61 inserted through the cable housing 12 and the nozzle 14, and a camera 65 attached to the tip of the cable 61 exposed to the outside of the nozzle 14 through the second opening 14B of the nozzle 14. More specifically, the cable 61 passes through the cable housing 12 and is inserted into the second space 14B1 of the nozzle 14, and the camera 65 is exposed from the second space 14B1 to the outside of the nozzle 14 through the second opening 14B.

(Work tools)
The work tool 30 includes a cable and a working part provided at the tip of the cable. The cable of the work tool 30 is inserted into the cable housing 12 and the nozzle 14, and the working part is exposed to the outside of the nozzle 14 from the first opening 14A of the nozzle 14. More specifically, the cable of the work tool 30 passes through the cable housing 12 and is inserted into the first space 14A1 of the nozzle 14, and the working part is exposed from within the first space 14A1 to the outside of the nozzle 14 through the first opening 14A. The working part of the work tool 30 is a tool for performing work on the scale S.

The work tool 30 will be described using Figures 7 and 8. Figure 7 is a schematic diagram of a collection tool. Figure 8 is a schematic diagram of a cleaning tool. The work tool 30 includes a collection tool 40 shown in Figure 7 and a cleaning tool 50 shown in Figure 8. That is, when collecting scale S, the collection tool 40 is used as the work tool 30, and when removing scale S by cleaning, the cleaning tool 50 is used as the work tool 30. Note that in this embodiment, the collection tool 40 and the cleaning tool 50 are not inserted into the nozzle 14 at the same time.

(Collection tool)
7, the retrieval tool 40 has an electromagnet 42 as a working unit, and a power cord 44, a wire 46, and an elastic body 48 as cables. In this embodiment, the elastic body 48 is, for example, a coil spring.

The electromagnet 42 is mounted at the tip of the recovery tool 40. An electromagnetic coil 43 is fixed to the outer periphery of the electromagnet 42. A female thread is formed within the electromagnet 42, to which a connecting fitting (swage fitting) 45 is connected. A power cord 44 and a wire 46 are connected to the electromagnet 42. The magnetic force of the electromagnet 42 is adjusted by turning the power on and off.

One end of the power cord 44 connects to the electromagnet 42, and the other end connects to positive and negative electrodes for connection to a power source. The power cord 44 is secured in place by bundling it with the wires 46 and tape at intervals.

The wire 46 includes two types of wires, 46A (first wire) and 46B (second wire), which differ in thickness and length. The first wire 46A is inserted into the steam generator 100 from the outside together with the power cord 44. A coil spring elastic body 48 is provided at the distal end of the first wire 46A. Specifically, the proximal end of the first wire 46A is provided outside the steam generator 100, and the distal end is connected to the proximal end of the elastic body 48. In this embodiment, the distal end of the first wire 46A and the proximal end of the elastic body 48 are secured to each other by crimping with a connecting fitting 47. The second wire 46B is provided so as to protrude from the distal end of the elastic body 48 (opposite the first wire 46A). Specifically, the proximal end of the second wire 46B and the distal end of the elastic body 48 are secured to each other by crimping. An electromagnet 42 is attached to the tip of the second wire 46B. For example, the connection between the electromagnet 42 and the second wire 46B is preferably covered with tape. Furthermore, the first wire 46A is preferably thicker than the second wire 46B.

In this way, by connecting the first wire 46A, elastic body 48, second wire 46B, and electromagnet 42 in that order, the deformation of the elastic body 48 allows the retrieval tool 40 to be properly inserted into the cable housing 12 and nozzle 14.

(Cleaning tool)
8, the cleaning tool 50 has a water-discharging nozzle 52 as a working part and a cable piping 59. The piping 59 is a pipe through which the cleaning liquid flows, and the water-discharging nozzle 52 is a nozzle formed with a hole through which the cleaning liquid is discharged.

The water-discharging nozzle 52 includes a nozzle portion 54, a screw member 56, and a connecting fitting 58. The water-discharging nozzle 52 is preferably made of metal, for example, and the length of the water-discharging nozzle 52 is preferably as short as possible.

The nozzle portion 54 has a spherical tip. The nozzle portion 54 also has multiple holes 54A formed along the circumferential direction for discharging the cleaning liquid. These holes 54A preferably have the same shape and are preferably evenly spaced circumferentially. The nozzle portion 54 is connected to the piping 59 via a screw member 56 and a connecting fitting 58. The nozzle portion 54 is formed with a male thread that threads onto the screw member 56. Forming a male thread on the nozzle portion 54 in this manner allows the nozzle portion 54 to be replaced. In this embodiment, eight holes 54A are formed, evenly spaced circumferentially. The holes 54A are preferably formed so that the total area of each hole 54A is equal to the cross-sectional area of the space inside the piping 59. Two to four of the holes 54A are preferably formed to face downward. This allows the cleaning liquid discharged from the holes 54A to be directed toward the tube support plate 108 without adjusting the direction of the cleaning tool 50. Here, the "circumferential direction" refers to the direction around the axial direction of the cleaning tool 50. The shape of the nozzle portion 54 and the number of holes 54A are not limited to a spherical shape or eight holes, and the shape, number of holes, hole diameter, position, etc. can be changed as appropriate.

One end of the screw member 56 is formed with a female thread into which the nozzle portion 54 screws, and the other end passes through a connecting fitting 58 and is inserted into the pipe 59. The connecting fitting 58 is a crimping fitting. The other end of the screw member 56 passes through the connecting fitting 58 to secure the screw member 56 in place.

The piping 59 is preferably a so-called high-pressure hose that can withstand high-pressure water discharge, and is preferably constructed by covering a flexible resin material (e.g., nylon, Teflon (registered trademark), urethane, etc.) with a stainless steel wire mesh. One end of the piping 59 has a threaded portion (not shown) that connects to the outside of the handhole H, and the other end is connected to the water-discharge nozzle 52. This reduces frictional resistance and allows the piping to be inserted smoothly between the heat transfer tubes 104A without buckling.

<Work method>
Next, a working method using the working equipment described above will be described. Figure 9 is a flowchart showing the procedure of the working method. Figures 10 to 12 are schematic diagrams for explaining the working method.

In the operation method according to this embodiment, a step is performed in which a cable housing 12 having a nozzle at its tip is inserted into the steam generator 100 through the hand hole H (step S10). Specifically, by rotating the handle 13A of the feeding device 13, the cable housing 12 wound around the reel 13B is fed into the steam generator 100 via the guide tray 11. In this step, the cable housing 12 may be inserted into the steam generator 100 with the fixing tool 16, work tool 30, and camera tool 60 inserted therein, or the fixing tool 16, work tool 30, and camera tool 60 may be inserted into the cable housing 12 and nozzle 14 after the cable housing 12 is inserted into the steam generator 100.

Next, the fixing portion of the fixing tool 16 is exposed from the nozzle 14, and a process is performed in which the nozzle 14 is fixed to the steam generator 100 using this fixing portion (step S12). Specifically, gas is supplied into the balloon 18 via the gas supply pipe 22 to inflate the balloon 18, thereby fixing the balloon 18 to the steam generator 100 components. More specifically, as shown in FIG. 10 , in step S12, the balloon 18 is inserted into the flow slot 108A of the tube support plate 108 to be worked on and inflated. The balloon 18 is inserted into the flow slot 108A from above so that the nozzle 14 is positioned above the tube support plate 108. Once inserted into the flow slot 108A, gas is supplied from the gas supply pipe 22 to the balloon 18, causing it to inflate. In this manner, the position of the nozzle 14 can be determined.

Next, as shown in FIG. 11, a process is performed in which the camera 65 of the camera tool 60 is advanced from the second opening 14B of the nozzle 14 to the outside of the nozzle 14 (step S14). As a result, an image captured by the camera 65 is displayed on the display means 64, allowing the position facing the tip 14T2 of the nozzle 14 to be visually confirmed. Thereafter, as shown in FIG. 12, a process is performed in which the working portion of the work tool 30 is advanced from the first opening 14A of the nozzle 14 to the outside of the nozzle 14 (step S16). Then, with the working portion of the work tool 30 exposed from the first opening 14A of the nozzle 14, the working portion is allowed to perform work.

More specifically, in this embodiment, work is performed using a recovery tool 40 as the work tool 30, and work is performed using a cleaning tool 50 as the work tool 30. Each work is described below.

(Collection method)
As shown in FIG. 12 , in step S16, scale (foreign matter) S is collected by the collection tool 40. The collection tool 40 is exposed from the first opening 14A. The collection tool 40 is sent into the heat transfer tube 104A simultaneously (in parallel) with the camera tool 60. The collection tool 40 collects the scale S on the tube support plate 108 by magnetic force from the electromagnet 42. The collection tool 40 collects the scale S in order to inspect it. Therefore, when cleaning is also performed, it is preferable that the collection tool 40 be the work tool 30 inserted first into the nozzle 14. It is preferable that collection by the collection tool 40 be performed sequentially from the upper tube support plate 108 of the body 102 to the lower tube support plate 108.

(Cleaning method)
As shown in FIGS. 7 and 12 , in step S16, the cleaning tool 50 discharges a cleaning liquid for cleaning. In this embodiment, the cleaning liquid is high-pressure water (e.g., approximately 2 MPa to 4 MPa). Once the cleaning tool 50 and the camera tool 60 are inserted between the heat transfer tubes 104A, the discharge of high-pressure water begins. Then, while discharging water, the camera tool 60 is also sent to the heat transfer tubes 104A, with the cleaning tool 50 leading the way. In this manner, scale S that has fallen onto the tube support plate 108 can be removed by the cleaning tool 50 while monitoring with the camera tool 60. Specifically, in cleaning, the scale S on the tube support plate 108 to be cleaned is dropped through a hole in the tube support plate 108 onto the tube support plate 108 located one level below. This process is repeated for each level, up to the tube support plate 108 located at the bottom. The scale S that has fallen onto the tube plate 106 is then collected together using an existing collection method other than the collection method disclosed herein. Note that the cleaning liquid is not limited to high-pressure water and may be any suitable liquid.

The cleaning tool 50 may also be exposed from the second opening 14B. In this case, the camera tool 60 is exposed from the first opening 14A. After the recovery operation, the work tool 30 may be replaced and the cleaning operation may be performed.

<Effects>
A work device 10 according to a first aspect of the present disclosure is a work device 10 for a steam generator 100 having a heat transfer tube 104A inside a body 102, and includes: a hollow cable housing 12 extending in the axial direction and insertable into a hand hole H formed in the body 102; a hollow nozzle 14 provided at the tip of the cable housing 12 and having a first opening 14A and a second opening 14B formed at the tip; a work tool 30 having a cable to be inserted into the cable housing 12 and the nozzle 14 and a working part provided at the tip of the cable and exposed from the first opening 14A; and a camera tool 60 having a cable to be inserted into the cable housing 12 and the nozzle 14 and a camera 65 provided at the tip of the cable and exposed from the second opening 14B. According to the present disclosure, work can be performed with the work tool 30 while monitoring with the camera 65 of the camera tool 60, so that appropriate work can be performed on foreign matter inside the steam generator 100.

The work tool 10 according to the second aspect of the present disclosure is the work tool 10 according to the first aspect, except that the nozzle 14 is formed with a first space 14A1 in which a first opening 14A is formed at the tip, and a second space 14B1 isolated from the first space 14A1 in which a second opening 14B is formed at the tip, and the work tool 30 is inserted into the first space 14A1, and the camera tool 60 is inserted into the second space 14B1. According to the present disclosure, the work tool 30 and the camera tool 60 can be inserted into the nozzle 14.

The work implement 10 according to the third aspect of the present disclosure is the work implement 10 according to the first or second aspect, in which the nozzle 14 is curved from the base end 14T1 to the tip end 14T2. According to the present disclosure, the camera tool 60 and the work tool 30 can be sent to the desired location.

The work equipment 10 according to a fourth aspect of the present disclosure is the work equipment 10 according to any one of the first to third aspects, wherein the nozzle 14 has a third opening 14C formed therein, and further includes a fixing tool 16 having a cable that is inserted into the cable housing 12 and the nozzle 14, and a fixing portion that is provided at the tip of the cable, exposed from the third opening 14C, and fixed to the steam generator 100. According to the present disclosure, the position of the nozzle 14 can be fixed.

The work implement 10 according to the fifth aspect of the present disclosure is the work implement 10 according to the fourth aspect, except that the fixed part is a balloon 18, and the cable of the fixed cable is a gas supply pipe 22 that supplies gas to the balloon 18. According to the present disclosure, the expansion of the balloon 18 can be adjusted by the amount of gas supplied, and the position of the nozzle 14 can be determined.

A work tool 10 according to a sixth aspect of the present disclosure is a work tool 10 according to any one of the first to fifth aspects, in which the working unit includes an electromagnet. According to the present disclosure, scale S can be collected.

The work implement 10 according to a seventh aspect of the present disclosure is the work implement 10 according to the sixth aspect, wherein the cable of the work tool 30 has a first wire 46A, an elastic body 48 attached to the tip of the first wire 46A, and a second wire 46B protruding from the elastic body 48 on the side opposite the first wire 46A and having an electromagnet 42 attached to its tip. According to the present disclosure, the work tool 30 can be properly inserted into the nozzle 14.

The work implement 10 according to an eighth aspect of the present disclosure is the work implement 10 according to any one of the first to seventh aspects, wherein the cable of the work tool 30 is a pipe 59 through which a cleaning liquid flows, and the working part is a water-discharging nozzle 52 formed with a hole 54A through which the cleaning liquid is discharged. According to the present disclosure, cleaning can be performed using the cleaning liquid.

The work implement 10 according to the ninth aspect of the present disclosure is the work implement 10 according to the eighth aspect, except that the water-discharging nozzle 52 has a spherical tip and multiple holes 54A formed along the circumferential direction. According to the present disclosure, cleaning liquid can be efficiently discharged.

A work method according to a tenth aspect of the present disclosure is a work method using the work tool 10 according to any one of the first to ninth aspects, and includes the steps of inserting the cable housing 12 into the steam generator 100 through the hand hole H, advancing the camera 65 of the camera tool 60 out of the nozzle 14 through the second opening 14B of the nozzle 14, and advancing the working part of the work tool 30 out of the nozzle 14 through the first opening 14A of the nozzle 14. According to the present disclosure, work can be performed using the work tool 30 while being monitored by the camera 65 of the camera tool 60.

Although the embodiments of the present disclosure have been described above, the embodiments are not limited to the content of these embodiments. Furthermore, the components described above include those that would be easily conceivable to a person skilled in the art, those that are substantially identical, and those that are within the scope of what is known as equivalents. Furthermore, the components described above can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments described above.

10 Work equipment 12 Cable housing 14 Nozzle 14A First opening 14A1 First space 14T1 Base end 14T2 Tip end 14B Second opening 14B1 Second space 14C Third opening 16 Fixing tool 18 Balloon 22 Gas supply pipe 30 Work tool 42 Electromagnet 46A First wire 46B Second wire 48 Elastic body 52 Water discharge nozzle 54A Hole 59 Piping 60 Camera tool 65 Camera 100 Steam generator 102 Body 104A Heat transfer pipe H Hand hole S Scale (foreign matter)

Claims (10)

A working device for a steam generator having a heat transfer tube inside a body portion,
a hollow cable housing that can be inserted into a hand hole formed in the trunk portion and extends in the axial direction;
a hollow nozzle provided at a tip of the cable housing, the nozzle having a first opening and a second opening formed at a tip portion;
a cable inserted into the cable housing and the nozzle, and a work tool having a working portion provided at a tip of the cable and exposed from the first opening;
a camera tool including a cable inserted into the cable housing and the nozzle, and a camera provided at a tip of the cable and exposed from the second opening;
having
work equipment. a first space in which the first opening is formed at a tip end thereof, and a second space isolated from the first space in which the second opening is formed at a tip end thereof,
The work implement of claim 1 , wherein the work tool is inserted into the first space and the camera tool is inserted into the second space. The work equipment described in claim 1 or claim 2, wherein the nozzle is curved from the base end toward the tip end. The nozzle has a third opening formed therein,
3. The work equipment according to claim 1 or 2, further comprising: a fixing tool having a cable that is inserted into the cable housing and the nozzle, and a fixing portion that is provided at a tip of the cable, exposed from the third opening, and fixed to the steam generator. The work equipment described in claim 4, wherein the fixing part is a balloon, and the cable of the fixing tool is a gas supply tube that supplies gas to the balloon. The work equipment described in claim 1 or claim 2, wherein the working unit includes an electromagnet. The cable of the work tool
A first wire;
an elastic body provided at a tip of the first wire;
The work tool according to claim 6 , further comprising: a second wire that projects from the elastic body opposite to the first wire and has the electromagnet attached to a tip thereof. The work equipment described in claim 1 or 2, wherein the cable of the work tool is a pipe through which cleaning liquid flows, and the working part is a water-discharging nozzle formed with a hole for discharging the cleaning liquid. The work equipment described in claim 8, wherein the water-discharging nozzle has a spherical tip and multiple holes are formed along the circumferential direction. A work method using the work equipment according to claim 1,
inserting the cable housing into the steam generator through the hand hole;
advancing a camera of the camera tool out of the nozzle through the second opening of the nozzle;
advancing a working portion of the working tool out of the nozzle through the first opening of the nozzle;
Including,
How to work.