JP2772275B2 - Working device in steam generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working device fed into a narrow space from the outside, and more particularly to a working device fed into a heat transfer tube bundle of a shell and tube heat exchanger type steam generator.

[0002]

2. Description of the Related Art In order to feed a visual inspection device, a cleaning device, or the like into a narrow portion such as the inside of a device, the original function of the device must be maintained. For example, in a shell-and-tube heat exchanger often used in nuclear power plants, a large number of thin heat transfer tubes are arranged at small intervals to form a heat transfer tube bundle. Foreign substances such as sludge to be brought in and sludge generated by itself may accumulate in the gaps between the heat transfer tubes. Therefore, inspection and cleaning are required. This will be described for a vertical steam generator which is one of shell-and-tube heat exchangers.

FIG. 15 conceptually shows the internal structure of the vertical steam generator 1. A plurality of inverted U-shaped heat transfer tubes are provided on a tube plate 5 integrally formed with an outer shell or shell 3. 7 are inserted and joined at both ends. Then, the high-temperature heating fluid 9 flows into the water chamber 11, and the heating fluid 9 flows through the heat transfer tube 7,
As will be described later, the temperature is lowered by applying heat and flows out of the water chamber 13. The heating fluid 9 is, for example, a reactor coolant. A number of heat transfer tubes 7 having different bending radii form a heat transfer tube bundle, which is surrounded by a wrapper tube 15 and supported laterally by a number of tube support plates 17. Then, the water supply 21 flowing through the water supply nozzle 19 flows down between the wrapper cylinder 15 and the shell 3, turns over on the upper surface of the tube sheet 5, and rises along the heat transfer tube 7. At that time, heat is removed from the heating fluid 9 by heat exchange, the temperature rises, the fluid boils, and becomes steam. The steam 23 flows out of the steam nozzle 25 and goes to, for example, a steam turbine. The tube support plate 17 is provided with the heat transfer tubes 7.
Must have sufficient rigidity and mechanical strength to appropriately support the flow of the rising water 21 with low resistance. There are various shapes of holes for water supply, but a so-called cloverleaf type integrated with a hole through which the heat transfer tube 7 passes is used, and furthermore, a straight leg portion of the heat transfer tube 7 having a minimum bending radius is used. A generally rectangular flow slot 27 is formed in the portion shown in FIG. The actual size of the flow slot 27 is 45
mm × 380 mm, and the number of tube support plates 17 used is 1
The number is about 0, and the height of the steam generator 1 is considerable.

Conventionally, the feedwater 21 contains sludge made of rust or the like generated from the system, and sludge is generated inside the steam generator 1, and these sludges are formed on the tube sheet 5 at the lowest position. Was expected to accumulate. Various devices for removing sludge on the tube sheet 5 have been proposed and used. For installation of these sludge removing devices in the steam generator, for example, an internal access handhole 29 near the level of the tube support plate 17 at the lowest position was used.

[0005]

Thus, when the steam generator 1 as described above is operated for a long period of time, the surroundings of the heat transfer tubes 7 on the tube support plate 17 other than the tube plate 5 initially expected. It has been found that sludge accumulates to some extent, and it has become necessary to remove the sludge. However, in a device which is a modification of the conventional device for removing sludge on the tube sheet 3, the tube support plate 1 which is considerably higher
Removal of sludge above 7 is not possible. Although it is an idea to provide the same thing as the conventional handhole 29 for each tube support plate, it is practical because the shell is a kind of pressure-resistant container and the tube support plate is actually several meters high. In addition, it is, of course, extremely difficult to add such a handhole to a steam generator that has already been manufactured and installed. From the above background, the conventional hand hole at a relatively lower position can be used and can be inserted from there, and the flow slot of the tube support plate can be used to place the sludge on each tube support plate. There was a need for an accessible sludge removal device. For the same reason, there has been a demand for a working device applicable to a visual inspection and maintenance device or the like that can be inserted into a narrow portion of a heat transfer tube bundle on each tube support plate. Therefore, an object of the present invention is to provide a guide mechanism that can be inserted from a relatively low hole such as a steam generator, can be guided upward through a narrow hole of a tube support plate, and can reach a narrow portion on the tube support plate. To provide an internal working device equipped with the same.

[0006]

According to the present invention, there is provided a working device having a movable lifting mechanism, which is pivotally attached to an end of an elongate body of the lifting mechanism. A telescopic mechanism having a telescopic arm, a feeding mechanism attached to the distal end of the telescopic mechanism, an elastic band-shaped member movably disposed along the lifting mechanism and the telescopic mechanism, and having a tool at the distal end. Wherein the feeding mechanism includes a driving device that drives the elastic band-shaped member in a longitudinal direction, a bending mechanism, and a turning mechanism. The telescopic mechanism is pivotable between a linear position extending in the longitudinal axis direction of the lifting mechanism and a right angle position that bends substantially perpendicularly to the longitudinal axis. After passing through the flow slots in the plate and onto the target tube support plate, it is bent to a right angle position. The feed mechanism has openable and closable support legs that cooperate with the telescopic mechanism, and opens when the telescopic mechanism is extended to support the feed mechanism firmly and movably on the tube support plate. The bending mechanism of the feeding mechanism normally does not operate and holds the elastic band-like member including the tool at the tip in a straight line, enters an operating state at a predetermined position, and guides the elastic band-like member at right angles. In this state, when the elastic belt-shaped member is sent by the drive mechanism, the tip tool is sent from the extension mechanism at right angles into the gap between the heat transfer tubes of the heat transfer tube bundle. For the tip tool,
When a small camera is built-in, the situation in the direction of travel is projected on the control panel of the remote control device,
Further, when a cleaning nozzle is included, a high-pressure cleaning liquid is blown out of the nozzle to flow out sludge around the heat transfer tube. Other power tools can also be appropriately attached to the tip of the elastic band-shaped member.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 1, a working device 30 according to the present invention includes a lifting mechanism 40, a telescopic mechanism 50, a feeding mechanism 60, which is moved on a base 31, and an elastic band member 80 having a tip tool 81. It is mainly composed. The base unit 31 is, for example, a portable rail, and the steam generator 1 as described above (FIGS. 15 and 16).
The shell 3 is carried into the inside through the handhole 29 and set on the lowermost tube support plate 17. The lifting mechanism 40 has various structures and will be described later.

Next, referring to FIG. 2, the telescopic mechanism 50 includes
It is mainly formed of five slidable telescopic arms 51 to 55, and a feeding mechanism 60 is attached to the telescopic arm 55. The feeding mechanism 60 includes a driving device, a bending guide 61, a cylinder 63, a turning mechanism 65, a support leg 67 that can be freely opened and closed, a spring 69, an operation wire rope 71, and the like, which will be described later. The support leg 67 has a wheel 6 at the lower end as shown in FIG.
8, which are formed mainly of symmetrical legs 67a, 67b with their upper ends pivotally mounted. Furthermore,
The elastic band member 8 is moved along the extension mechanism 50 and the lifting mechanism 40.
0 extends, and the tip tool 81 at the front end thereof
Projecting forward. The tip tool 81 has a plurality of cleaning liquid nozzles 83 formed on a rectangular block plate and a camera 85 at the center as shown in FIG.
A high-pressure hose connected to the camera 3 and a cable and the like connected to the camera 85 are gathered in a belt shape to form an elastic belt member 80.

[0009] The working device 30 configured as described above,
When passing through the flow slot 27 of the tube support plate 17 in the steam generator 1, that is, when the telescopic mechanism 60 and the feeding mechanism 80 pass through the flow slot 27 by the lifting mechanism 40, FIG.
Take the posture shown in. That is, the extension mechanism 50 is in a retracted shape, is linear with the longitudinal axis of the lifting mechanism 40, the feeding mechanism 60 is also located at the rearmost end, and the bending guide 61
Open to maintain the elastic band member 80 in a straight line without bending. By doing so, the projected area of the portion passing through the flow slot 27 is reduced. And the support leg 67
Is flipped forward. In this way, when the lifting mechanism 40 raises the telescopic mechanism 50, the feeding mechanism 60, and the like to above the target pipe support plate 17, the telescopic mechanism 50 and the like are rotated counterclockwise by 90 degrees in FIG. Then, it is set to a position perpendicular to the longitudinal axis of the lifting mechanism 40. And
When the lower surface of the extension mechanism 50 is slightly lowered so as to reach the upper surface of the tube support plate 17, the state shown in FIG. 6 is obtained. FIG. 7 shows the state of the legs 67a and 67b of the support leg 67 in the state of FIG.

The mounting structure of the support leg 67 will be further described. The legs 67a and 67b are mounted near the distal end of the feeding mechanism 60 via a cam 65 as shown in FIGS. 8 (a) and 8 (b). FIG. 8B is a side view showing a state in which the support leg 67 is in a vertical posture, and FIGS. 8C and 8D are enlarged cross-sectional views of a pivot portion of the support leg 67. The former is the support leg 67. Is in a vertical position with the legs open and the latter is
Shows a state in which the player is leaning forward and is in a closed state. Support leg 67
Is constantly pulled forward by a spring 69 so as to be in a closed state, and while the telescopic arm is contracted and the lifting mechanism 40 is operating as shown in FIGS. 5 and 6,
Since it is kicked at the tip of the extension mechanism 50 and mechanically locked, it does not take an upright posture, and the support leg 67 maintains the closed state. Note that the support leg 67 is tilted backward by an external operation panel to which the wire rope 71 is connected.

As can be easily understood from FIG. 16, some of the multiple inverted U-shaped heat transfer tubes 7 are arranged so as to be located in the same plane to form one heat transfer tube row. The rows are arranged at predetermined intervals in parallel with each other to form a heat transfer tube bundle as a whole. This row of heat transfer tubes intersects at right angles to the longitudinal axis of the flow slot 27. To remove sludge around the heat transfer tubes 7, a tip tool is inserted into the gap between adjacent heat transfer tube rows. The cleaning liquid is ejected from the nozzle 83 by sending 81. Therefore, in order to feed the tip tool 81 into the gap between the heat transfer tube rows (hereinafter simply referred to as the heat transfer tubes 7), it is necessary to extend the extension mechanism 50 and move the tip tool 81 to a predetermined position corresponding to the target gap. For this purpose, as shown in FIG. 2, the distal end of the telescopic mechanism 50 is pushed forward to release the mechanical lock, and the wire rope 71 connected to the operation panel outside the steam generator 1 is operated. , Support leg 67
Is upright and the legs are open. In this way, even if the expansion / contraction mechanism 50 extends and the feeding mechanism 60 projects forward, the wheels 68 of the support legs 67 are located outside the flow slot 27 so that the feeding is performed without fitting into the flow slot 27. Mechanism 60
Firmly and without bending.

When the feeding mechanism 60 advances to a predetermined position corresponding to the gap into which the tip tool 81 is to be inserted with the tip tool 81 protruding forward, the cylinder 63 is extended and the bending guide 61 is moved counterclockwise. Is turned to the operating position, the state shown in FIG. 9 is obtained. As shown in the drawing, the extension mechanism 50 and the feeding mechanism 60 extend substantially horizontally, and the elastic band-shaped member 80 extends along the extension mechanism. The tip tool 81 is bent at substantially a right angle and faces downward. FIG. 10 shows a vertical section of the feeding mechanism 60 in this state. The motor 73 is for the turning mechanism 65 and is combined with a spur gear (not shown) to turn the main body of the feeding mechanism 60 around the axis by approximately 90 degrees as described later. The motor 75 is for a driving device, and drives the pair of driving rollers 77 to feed the elastic band-shaped member 80 sandwiched in the longitudinal direction. Another pair of guide rollers 79
Turns the elastic band member 80 in a predetermined direction. That is, if the bending guide 61 is in the inoperative position in FIG. 2, the band-shaped member 80 is sent out straight without bending, while if the bending guide 61 is in the operating position as shown in FIG.
The same is true).

When the motor 73 of the turning mechanism 65 is operated and the feeding mechanism 60 is turned 90 degrees from the state shown in FIG. 9, the tip tool 81 is oriented in the horizontal direction as shown in FIGS. That is, it points to the target gap between the heat transfer tubes 7 to be inserted. If the motor 75 of the driving device is driven in this state, the tip tool 81 advances toward the gap,
Get into the gap. At this time, the camera 85 displays the state in the traveling direction and displays an image on a display of an operation panel outside the steam generator. The camera 85 is used to monitor and grasp the state of the moving direction even when the feeding mechanism 60 is moved up and down by the lifting mechanism 40 and when the feeding mechanism 60 is horizontally moved by the telescopic mechanism 50 in addition to the above. Is done.

Next, using a box-link type lifting mechanism 40, the telescopic mechanism 50, feeding mechanism 60, etc.
The process of lifting up will be described with reference to FIGS. First, a handhole 2 as shown in FIG.
The base 31 is formed by setting the portable rail carried in through the hand hole 29 on the tube support plate 17 close to the base 9 (see FIG. 13B). Next, the curved guide 41 of the lifting mechanism 40 is inserted into one of the hand holes 29, and is set on the base portion 31, and is inserted through the box-shaped link 43 of the lifting mechanism 40 (FIG. 13 (c)). )). Further, the expansion / contraction mechanism 50, the feeding mechanism 60, and the elastic band member 80 are carried in through another hand hole 29, and these are attached to the tip of the box-shaped link 43 (FIG. 13D). Thereafter, the tip of the guide 41 is lifted (FIG. 13 (e)), and the guide 41 is angularly fixed by the link support 45 with the tip of the link 43 and the tip of the guide 41 being vertical (FIG. 13 (e)). f)). The link 43 is located at a predetermined position below the flow slot 27 through which the lifting mechanism 40 should pass.
Is moved on the base 31.

When the link 43 is fed through the guide 41 by the lifting drive unit 47 installed outside the steam generator 1, the distal end of the link 43 and the telescopic mechanism 5 attached thereto are sent.
0, the feeding mechanism 60 and the like rises steadily and protrudes the neck above the target pipe support plate 17 (FIG. 14A). This state corresponds to the state shown in FIG.
Is rotated by 90 degrees, as shown in FIG. 14B, which corresponds to FIG. In this way, the target tube support plate 1
7, a telescopic mechanism 50 set horizontally on the
Elastic band member 80 including feeding mechanism 60 and tip tool 81
Is operated as described above to wash and remove sludge around the heat transfer tube 7. In the above-described embodiment, the tip tool 81 is a cleaning nozzle and a camera. However, a predetermined operation can be performed by using, for example, only the camera as an inspection tool or attaching a sample collection device or the like.

[0016]

As described above, according to the present invention, the telescopic mechanism moves the feed mechanism horizontally to the position corresponding to the gap between the target heat transfer tubes, and further rotates the feed mechanism about the axis so that the distal end moves. Since the tool is directed toward the target gap and further driven in the longitudinal direction to feed the tip tool toward the target gap, a predetermined operation can be smoothly performed. Further, the openable and closable support legs provided in the feeding mechanism prevent the tube supporting plate from being fitted into the flow slot, and prevent the expansion and contraction mechanism and the feeding mechanism from bending when the expansion and contraction mechanism is extended. The tool can be inserted into a narrow gap by maintaining the tool in a predetermined posture.

[Brief description of the drawings]

FIG. 1 is a conceptual perspective view showing an embodiment of the present invention.

FIG. 2 is a partial side view showing a main part of the embodiment.

FIG. 3 is a partial front view as viewed from a direction III in FIG. 2;

FIG. 4 is a partial perspective view showing a part of the embodiment.

FIG. 5 is an operation explanatory view of a main part of the embodiment.

FIG. 6 is an operation explanatory view of a main part of the embodiment.

FIG. 7 is a conceptual front view as viewed from a direction VII of FIG. 6;

FIG. 8 is an operation explanatory view of a part of the embodiment.

FIG. 9 is an operation explanatory view of a main part of the embodiment.

FIG. 10 is a partial sectional view of a main part of the embodiment.

FIG. 11 is an operation explanatory view of a main part of the embodiment.

FIG. 12 is a partial front view as seen from the XII direction in FIG. 11;

FIG. 13 is a process diagram illustrating the operation of the lifting mechanism of the embodiment.

FIG. 14 is a process diagram illustrating the operation of the lifting mechanism of the embodiment.

FIG. 15 is a conceptual vertical sectional view showing an example of the structure of a steam generator in which the working device of the present invention is used.

FIG. 16 is a schematic plan sectional view of the steam generator of FIG. 15;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam generator 7 Heat transfer tube 17 Pipe support plate 27 Flow slot 30 Working device 31 Base part 40 Lifting mechanism 41 Guide 43 Link 45 Link support 50 Telescopic mechanism 60 Feeding mechanism 61 Bending guide 63 Cylinder 65 Rotating mechanism 67 Support leg 73 Motor 75 Motor 77 Roller 79 Roller 80 Elastic strip member 81 Tip tool 83 Nozzle 85 Camera

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 1-1106705 (JP, U) JP-A 58-51992 (JP, U) JP-A 62-172578 (JP, U) JP-A 62-172578 166403 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F22B 37/02

Claims (1)

(57) [Claims] 1. A working device having a movable lifting mechanism, comprising: a telescopic mechanism having a multi-stage telescopic arm pivotally attached to a distal end of an elongate body of the lifting mechanism; and a working device attached to a distal end of the telescopic mechanism. A feeding mechanism, and an elastic band-shaped member movably disposed along the lifting mechanism and the expansion / contraction mechanism and having a tool at a tip thereof, wherein the expansion / contraction mechanism extends in a longitudinal axis direction of the lifting mechanism. straight
A right angle position that bends at a right angle to the longitudinal axis from the line position
Pivotable between a location at the time of lifting operation of the lifting mechanism
Is in the straight position and passes through the flow slot of the tube support plate.
When it reaches the target pipe support plate,
The feeding mechanism includes a driving device for driving the elastic band-shaped member in a longitudinal direction, and a tool at the tip which is normally inoperative and is not actuated.
Holding the elastic band-shaped member in a straight line, at a predetermined position
A bending mechanism for operating the elastic band-shaped member in a right angle direction in an operating state, and rotating the main body of the feeding mechanism by 90 degrees around an axis.
A swiveling mechanism for opening and closing, cooperating with the telescopic mechanism.
When the telescopic mechanism is extended, it opens and the feed mechanism is placed on the tube support plate.
A working device in a steam generator, comprising: a supporting leg for supporting the movable member securely and movably .