KR100820236B1 - Steam generator sludge lancing system with flexible inter-tube lance - Google Patents

Abstract

A steam generator sludge lancing system with a flexible inter-tube lance is provided to improve maintenance and repair by preventing errors of servo motors through installation of the motors outside a steam generator. A steam generator sludge lancing system includes a rail guide(500), a T-rail(700), a flexible inter-tube lance(900), and a lance head. The rail guide mounts a driving unit support flange(301) and a rail guide support flange(302) on a hand hole without a fixing bar in a center and is installed inside a steam generator through the driving support flange. The T-rail is installed through a groove of the rail guide, has a high flow rate barrel spray nozzle, and is rotatable to be twisted. The lance is bent at an angle of 90 degrees by a bending guide coupled to an end of the T-rail by being inserted into the T-rail. The lance head has nozzle tips with various injection angles and is coupled to an end of the flexible inter-tube lance.

Description

Steam generator cleaning equipment with flexible plate structure {STEAM GENERATOR SLUDGE LANCING SYSTEM WITH FLEXIBLE INTER-TUBE LANCE}

1 is a perspective view of a steam generator cleaning equipment having a flexible plate structure according to an embodiment of the present invention installed in a steam generator.

Figure 2 is an enlarged perspective view of the flow of the secondary cooling water and steam generator lower portion of the heavy water reactor steam generator.

3 is a perspective view showing the entire steam generator cleaning equipment of the flexible plate-like structure.

4 is a perspective view showing a driving unit of the steam generator cleaning equipment of the flexible plate-like structure.

5 is a perspective view showing a rail guide of the steam generator cleaning equipment of the flexible plate-like structure.

6 is a perspective view of a rail guide tensioning device of the steam generator cleaning equipment of the flexible plate-like structure.

7 is a perspective view showing the T-rail of the steam generator cleaning equipment of the flexible plate-like structure.

FIG. 8 is a perspective view illustrating the T-rail tensioning device for steam generator cleaning equipment of the flexible plate structure.

9 is an enlarged perspective view illustrating the barrel spray and the flexible plate-shaped lance of the steam generator cleaning equipment of the flexible plate-type structure.

FIG. 10 is a perspective view illustrating a bending guide for inducing bending of the flexible plate-shaped lance in the steam generator cleaning equipment of the flexible plate-type structure of the present invention.

<Description of Symbols for Main Parts of Drawings>

200: steam generator 201, 202: hand hole

300: cleaning equipment 301: drive support flange

302: rail guide support flange 303: spur gear

402, 417, 412: 1st, 2nd, 3rd servo motor

404: gear 407: high pressure hose

409: motor case for roller 415: motor case for rack gear

500: rail guide 501: rail guide tensioning device

700: T-rail 701: segment

703: rack gear 900: lance

910 lance head

The present invention relates to a steam generator cleaning equipment of a flexible plate-like structure, and more particularly, to clean the sludge attached to the steam generator of the nuclear power plant using high pressure water and to remove foreign substances present in the tube sheet top plate. The present invention relates to a steam generator cleaning equipment having a plate-like structure.

In general, a steam generator of a nuclear power plant is a place where the first coolant and the second coolant meet with heat energy generated from a nuclear reactor, and are very important structures in which heat exchange occurs on the heat exchanger tube of the steam generator.

Steam generated in this process turns turbines and converts kinetic energy into electrical energy. However, as the operating history of a nuclear power plant increases, secondary system pipes wear out, causing metal components from the pipes to deposit sludge in the steam generator or from the structure due to maintenance during the nuclear plant's planned prevention period. The components enter the steam generator and exist as foreign substances.

These steam generator sludges are classified into soft sludge and relatively soft hard sludge, which is usually hard to be deposited. The sludge deposited on the tube-sheet of the lower stage of the steam generator is deposited in the form of hard sludge by the hot heat of the heat pipe.

This deposited sludge lowers the heat transfer capacity of the steam generator tubules, resulting in lower heat output efficiency and ultimately directly related to power reduction of the power plant. Overseas nuclear power plants have been reported as cases of shutdown of power plants due to declining output. In addition, premature replacement of the steam generator due to local corrosion of the steam generator causes huge economic losses.

In addition, since the foreign substances existing on the shell side of the steam generator customs are carried by this flow rate during circulation of the system water, the possibility of damage due to impacts on the structure in the steam generator remains, so the nuclear power plant periodically As a preventive maintenance plan, sludge and foreign substances are removed during this period.

Here, the method of removing the steam generator sludge includes high-pressure water injection method, chemical cleaning method, ultrasonic cleaning method, and combined cleaning method. Among these, the chemical cleaning method has the highest cleaning efficiency, but is relatively susceptible to vulnerabilities such as customs corrosion. Due to exposure, chemical cleaning has been limited to two or three times during the life of the steam generator.

In the case of ultrasonic cleaning, which has recently been intensively developed, evaluation of cleaning efficiency has not been accurately presented, but various cleaning technologies are actively being developed as technologies that can be spotlighted in the future. With no clear alternative developed yet, the realistic cleaning method is one of the most advantageous alternatives.

As a technology to remove foreign substances, it is possible to remove them by using various special tools such as tongs, trickle hooks, nooses, magnets, etc. These tools alone have limitations in removing them, so they can be removed with high-pressure water cleaning. have.

Conventionally, in the case of the device for removing the sludge and foreign substances present in the steam generator, there was a bar (invention number 10-2004-0090110) that was invented before, but it was possible to access between the heat pipes with a belt-type flexible lance, The side effects of sagging down by the band-shaped nut coupling method and the lance drive motor are placed inside the steam generator, which is exposed to high radiation, causing frequent failures due to deterioration due to material radiation.

The present invention has been made to solve the above-mentioned problems, the object of the present invention is to improve the weaknesses and enhance the convenience of the technology, the steam generator tube tube is easily passed through the narrow gap between the heat exchanger tube sheet on the steam generator tube sheet It is to provide a steam generator cleaning equipment with a flexible plate-like structure that can easily remove the sludge and foreign matter deposited on the.

In addition, the present invention provides a tool that can easily remove the steam generator sludge and foreign matter by inspecting the inside of the steam generator to easily remove the location of the foreign material and confirmed access to the foreign matter and the degree of cleaning after sludge cleaning It is to provide the steam generator cleaning equipment with flexible plate-shaped structure that provides the monitoring function for easy checking.

The main configuration of the steam generator cleaning equipment of the present invention proposed to achieve the above technical problem, relatively small hand holes (201, 202) having a heat transfer tube region formed in a rectangular shape in the center of the interior The rail guide 500 having a T-shaped groove 503 installed in the steam generator 200 to be formed, is formed in the form of a protrusion 702 having a T-shaped cross section and capable of high flow cleaning. T-rail 700 with barrel spray, endoscope camera 901, air supply line 902, debris removal tool 903, and nozzle tip for spraying high pressure water , 905, 906, 907 and the lance 900 of the flexible plate-like structure consisting of a high-pressure hose 909 connected to each nozzle tip (904, 905, 906, 907), the steam generator 200 without a fixed rod therein Steam generation of flexible plate-like structures at both sides of the hand holes 201 and 202 It characterized by comprising a rotary driving part supporting the support flange 301 and the guide rail support flange 302 for guiding the fixing of the cleaning device (300).

In addition, the two types of drive support flanges 301 and the rail guide support flanges 302 are installed in the hand holes 201 and 202 having a relatively small diameter, among which the drive support flanges 301 have a flexible plate shape. The stud bolt through-hole 419 is mounted in the hand hole 201 into which the steam generator cleaning equipment 300 of the structure is inserted. The bolt through hole 419 can be firmly fastened to the hand hole 201, and a rail guide tensioning device 501 having a gear 603 for torsional rotation of the rail guide 500 is provided with a driving support flange 301. Coupled with the bearing holder portion 406 of the rail guide 500, T-rail 700, characterized in that it can perform a smooth torsional rotation with the flexible plate-like lance (900).

In addition, six stud bolts pass through the through hole 306 by using a stud bolt (not shown) in the steam generator 200 hand hole 202 of the remaining type of rail guide support flange 302. It is firmly fixed and has a bearing holder 308 so as to support the rail guide end coupling portion 304 in rotation.

Meanwhile, the rail guide tensioning device 501 coupled to the rail guide 500 by bolts serves to transfer the rotational force received from the first servomotor 402 to the rail guide 500 while the rail guide tensioning device 501 is coupled to the rail guide 500. And a wire tensioner lever 601 that simultaneously tightens the tensioning wire 504.

In addition, the rail guide 500 is a rod-shaped cross-section having a half-moon-shaped cross section having a T-shaped groove 503, which may be further segmented as needed, and the assembly pins are formed at the segmented portion. 505, the T-shaped groove 503 is in a straight line, by tightening the tensioning wire 504 with the tensioner lever 601 is characterized in that several segments are firmly fastened like a rod do.

In addition, the T-rail 700 having the projection 702 having a T-shaped cross section also has an assembly pin 705, a tensioning wire 704, and a tensioner lever 801, like the rail guide 500. The segment 701 of the segmented T-rail 700 is firmly coupled like a rod and the rack gear 703 is machined in the protrusion 702 having a T-shaped cross section so that the rail guide 500 in the T The T-rail 700 can slide back and forth along the groove 503, and has a rectangular hole 311 through which the lance 900 of the flexible plate structure can pass. A relatively large flow rate of the high pressure water supplied from the high pressure hose 407 can be injected from the plurality of barrel spray nozzles (908).

The flexible plate-shaped lance 900 is laminated and processed with a polyurethane material so that the displacement of the upper and lower sides is very limited and the left and right displacements are relatively free, and have a structure that can be easily bent. Endoscopic camera 901, the endoscope camera 901 which can visually inspect the small high-pressure hose 909 and the nozzle tips (904, 905, 906, 907) and the steam generator 200 that can spray high-pressure water ) It is characterized in that it comprises a cleaning air injection pipe 902 to remove the foreign material of the lens to ensure a clean image, a foreign material removal tool 903 capable of removing the found foreign material.

Hereinafter, with reference to FIGS. 1 to 10 of the accompanying drawings will be described in detail the operation and preferred embodiment of the steam generator cleaning equipment of the flexible plate structure consisting of the components described above.

The steam generator 200 is where the reactor coolant and the secondary coolant heated in the nuclear power plant generate heat by exchanging heat, and FIG. 2 shows the flow of the secondary coolant of the steam generator, and the enlarged portion is relatively. It shows the upper part of the tube-sheet under the steam generator where the sludge flows relatively slowly due to the slow flow of the metal sludge. Therefore, the steam generator cleaning equipment 300 of the flexible plate-like structure is installed here to remove metallic sludge.

FIG. 1 is a view in which a steam generator cleaning equipment having a flexible plate-like structure is installed in a no-tube-lane on a tube-sheet below the steam generator of FIG. 2.

In order to install the flexible plate-type steam generator cleaning equipment 300, the steam generator 200 using the stud bolt through the through-hole 306 of the rail guide support flange 302 assembled with the bearing holder 308 first. ), An encoder 401 for firmly fixing to the handhole 202 and obtaining information of the torsional rotation, a gear head 403 for increasing the rotational torque of the motor, and a gear 404 for transmitting the rotational force of the motor. The first servomotor 402 to the drive support flange 301 with bolts and firmly fasten the drive support flange 301 to the hand hole 201 of the steam generator 200 using a stud bolt. (See FIGS. 1 to 4)

As shown in FIG. 3, the rail guide 500 end coupling portion 304 is coupled to the last segment 502 of the segmented rail guide 500 and the rail guide tensioning device 501 is connected to the first segment 502. ), And then align each segment 502 of the rail guide 500 segmented using the assembly pin 505 and the hole in a straight line, and then use the tensioner lever 601 to tighten the tensioning wire 504. By tightening, each segment 502 of the rail guide 500 becomes hard as a rod, and the rail guide support flange 302 to the end coupling portion 304 of the rail guide 500 pushed into the driving support flange 301. Is fastened and the bearing holder portion 406 of the driving support flange 301 and the rail guide tensioning device 501 are fastened, and a smooth torsional rotation is possible using the bearing.

In FIG. 4, the second servomotor 417 having the encoder 418 and the gear head 416 is mounted on the rack case motor case 415, and then the rack gear motor case 415 is mounted on the rail guide tensioning device. The rack gear motor case 415 rotates together when the rail guide 500 rotates by fastening to the 501 through the screw hole 602.

The bending guide 1000 shown in FIG. 10 is fastened to the last segment 701 of the T-rail 700 through the bolt through hole 1001 and the tensioner lever on the first segment 701 of the T-rail 700. After the T-rail tensioning device 803 equipped with the 801 is fixed through the bolt through hole 804, the segments 701 of the T-rail 700 are aligned in a straight line through the assembly pin 705. After making, tighten the tensioning wire 704 with the tensioner lever 801 to tightly couple the T-rail 700 as if it were a rod.

After the assembly of the T-rail 700, the third servo motor 412 having the encoder 410 and the gear head 413 and the roller 414, respectively, is mounted to the motor case 409 for the roller. And the motor case 409 for the roller and the roller when the T-rail 700 rotates by fixing through the screw hole 802 of the T-rail tensioning device 803 in which the motor case 409 for the roller is assembled. Join 414 to rotate together.

As shown in FIG. 9, the rectangular plate-shaped hole 311 of the T-rail 700 is inserted into the lance 900 of the flexible plate-shaped structure until the lance head 910 of the flexible plate-shaped lance 900 is visible. Inserted into the valve, where the interaxial play of the rollers 414 needs to be adjusted appropriately. The roller motor case 409 is designed to give a thread-through hole of the roller motor case 409 so as to adjust the gap between the motor shafts so that the clearance between the rollers 414 between the shafts is appropriately adjusted, and then the flexible plate shape is provided. Insert the lance 900 of the structure.

The T-rail 700 into which the lance 900 of the flexible plate structure is inserted is inserted into the T-shaped groove 503 of the rail guide 500 already installed in the steam generator 200 handhole 201. After inserting the projection 702 having a cross-sectional shape, the T-rail 700 allows the T-rail 700 to move forward and backward along the groove 503 of the rail guide 500. The rack gear 703 of 700 and the spur gear 303 fixed to the shaft of the second servomotor 417 are assembled to be well engaged.

If the steam generator cleaning equipment 300 is installed in the steam generator 200, the cleaning operation and the foreign matter removal operation of the present invention will now be described in detail.

First, the last nozzle 908 of the nozzles 908 of the barrel spray of the T-rail 700 using the second servomotor 417 is the steam generator 200 hand holes (301) in which the driving support flange 301 is installed. In view of 201), the last column of the heat pipe arrangement as the first column is located at the center of the first column and the second column, and the six barrel spray nozzles 908 are located in the middle between each heat pipe column. Done.

At this time, a large amount of high pressure water is supplied to the nozzle 908 of the barrel spray and sprayed. The nozzle 908 of the barrel spray is tilted using the first servomotor 402 and the inside of the steam generator 200 is sprayed. Push the metallic sludge out of the annulus with high pressure water. After the same operation is performed three or more times, the T-rail 700 is rotated by 180 ° using the first servomotor 402 to push the metallic sludge of the opposite heat pipe toward the outside of the annular portion.

After the barrel spraying operation between the first column and the second column is completed, the second servomotor 417 is driven, and the barrel spraying operation is repeated by moving the T-rail 700 about three columns. Repeat the barrel spray until the last column with a distance of three columns.

Since this series of tasks is a simple repetitive task, it is designed to be automated so that the operator can only supervise. Of course, you can do this manually yourself.

After the barrel spraying operation is completed, the flexible plate-shaped lance head 910 shown in FIG. 9 is moved back to the center of the first column and the second column of the steam generator 200 heat pipe and thus the flexible plate-shaped lance head ( The sludge adhering to the heat transfer pipe is removed by spraying high pressure water between the first column and the second column with the nozzle tip 904 facing forward and the nozzle tip 905 facing forward of 910.

Thereafter, when the third servomotor 412 drives the roller 414 installed side by side and pushes the flexible plate-shaped lance 900 between the T-rails 700 using the friction force of the roller 414, the T The bending guide 1000 assembled at the end of the rail 700 is bent between the heat transfer tubes by the induction of the lance passage 1002, and the lance head 910 of the flexible plate-like structure enters between the first column and the second column of the heat transfer tube.

Before the flexible plate-shaped lance head 910 enters between the heat pipes, each nozzle tip 904, 905, 906, and 907 mounted to the head portion injects high pressure water, which is a flexible plate-shaped lance head 910. In order to prevent the occurrence of a jam (jam) between the heat pipes of the flexible plate-shaped lance head 910 by removing the sludge fixed to the heat pipes to enter.

To explain the use of each nozzle tip (904, 905, 906, 907) forward nozzle tip 905 is sludge fixed to the side of the heat pipe between the columns, the nozzle tip 904 toward the diagonal direction is the heat transfer pipe The sludge existing between the diagonal lines of the array, the nozzle tip 907 facing to the left and right, the sludge existing between the rows of the heat pipe, the nozzle tip 906 facing up and down is stacked on the steam generator 200 tube sheet The purpose is to remove the sludge.

After the above operation is repeated in the heat transfer tube array, the cleaning operation is completed, and then moved between the first column and the second column of the heat transfer tube array to perform foreign material inspection and removal.

The endoscope camera 901 mounted on the flexible plate-shaped lance head 910 may inspect the heat transfer tube. In order to ensure lens integrity of the endoscope camera 901, an air supply line 902 is provided. Blow out the moisture from the lens using) to check for foreign matter between the heat exchanger tubes while ensuring a clear field of view.

When the foreign matter among inspection found, determine the location and type of foreign matter to replace it with a foreign material removing tool (903) for the type of debris to remove debris, the debris removal tool 903 is connected to the front end of the cable to the cable Move along, but can be removed and replaced with commonly used tongs, tricycle hooks, snares, magnets, etc. If it is difficult to remove the foreign matter with a removal tool, spray the high pressure water to the nozzle tip 905 facing forward steam generator (200) Push it out of the heat pipe and remove it from the annulus. This operation is repeated between the heat pipe columns.

The steam generator cleaning equipment of the flexible plate-like structure of the present invention can be installed in a very small steam generator handhole having a diameter of 63 mm or less, and a lance of a flexible plate-shaped structure between very narrow steam generator heating tubes having a thickness of 5 mm or less. It is possible to remove sludge by spraying high pressure water to enter and remove foreign substances existing between heat pipes by using various special tools mounted on the head of the lance.

In addition, since the servomotors providing the driving force of the present invention are all installed outside the steam generator, in the previous invention, the servomotors are installed inside the steam generator in the high radiation region to solve the problem of causing frequent failures, thereby improving maintenance. There is.

In addition, as the injection angle of the high-pressure water jet nozzle tip is diversified, sludge is attached to the moving passage by pre-cleaning the moving heat pipes by spraying high pressure water in a diagonal direction before the lance moves between the heat pipes. It is effective in preventing jams that occur due to narrowness.The nozzle tip is installed on the left and right sides of the flexible plate-shaped lance head to remove sludge from the rear of the heat pipe that could not be removed before. The sludge deposited on the tube sheet can also be removed by using the nozzle tip toward the top, thereby improving the cleaning efficiency.

Claims (12)

In the steam generator cleaning equipment, Rails that are installed inside the steam generator through the drive support flange and the drive support flange and the rail guide support flange are attached to the hand-hole without the fixed rod in the center in the structure that the accommodating space is elongated in the rectangular shape. Rail-guide; A T-rail installed through the groove of the rail guide and having a barrel spray nozzle having a high flow rate and having a torsional rotation thereof; A flexible plate-shaped lance inserted into the T-rail and bending in a 90 degree direction by a bending guide coupled to an end of the T-rail; And A lance head coupled to the lance end of the flexible plate-like structure and having nozzle tips of various injection angles; Steam generator cleaning equipment of the flexible plate structure characterized in that comprises a. The method of claim 1, wherein the rail guide support flange, It is attached to the opposite steam generator hand hole into which the rail guide is inserted to support the rail guide end coupling portion, and there is a bearing holder therein so that the rail guide smoothly performs the torsional rotation. Cleaning equipment. According to claim 1, The drive unit support flange, A first servomotor is attached to the steam generator hand hole into which the rail guide is inserted and provides a driving force to allow the rail guide to torsional rotation, and includes a bearing holder to support the rail guide tensioning device to rotate. Steam generator cleaning equipment with flexible plate structure. According to claim 2 or 3, wherein the rail guide, Composed of three or more segments, each segment has a T-shaped groove, and each segment is connectable by an assembly pin provided therein, and a tensioning wire and a rail guide tensioning device. (tensioning device) is included, the segments of the rail guides are firmly combined as if it is a rod to guide the T-rail to the linear reciprocating motion inside the steam generator, and the torsional rotation itself is possible Steam generator cleaning equipment in plate-shaped structure. According to claim 4, The rail guide tensioning device, The gear is machined in the cylindrical part to be coupled to the last segment of the rail guide and to receive the driving force of the first servomotor, and the groove is along the path of the tensioning wire so that the tensioning wire eliminates interference to other parts. Steam generator cleaning equipment of the flexible plate structure characterized in that the rail guide is firmly fixed by tightening the wire by the tensioner lever connected to the tensioning wire. The method of claim 5, wherein the T-rail, It consists of three or more segments like the rail guide, and can be firmly combined like a single bar using assembly pins, tensioning wires, and T-rail tensioning devices, and the rack gear has a T-shaped protrusion. Processed on the upper side, the driving force of the second servomotor mounted on the motor case for the rack gear is transmitted through the spur gear to reciprocate linearly along the T-shaped groove of the rail guide, and the flexible plate-shaped lance is roller inside. A rectangular cross-sectional groove is formed to receive a driving force by the roller of the third servomotor mounted on the motor case for linear reciprocating motion, and the first segment guides the flexible lance to bend at 90 °. Steam generator cleaning equipment of the flexible plate-like structure characterized in that it comprises a bending guide (bending guide). The method of claim 6, wherein the T-rail tensioning device, The T-rail is joined to the last segment of the T-rail and grooved along the path of the tensioning wire so that the tensioning wire does not interfere with other parts, and the T-rail is firmly tightened by tightening the wire with a tensioner lever to which the tensioning wire is connected. Steam generator cleaning equipment of the flexible plate-like structure, characterized in that fixed as a stick. The method of claim 7, wherein the bending guide, Finally, the T-rail segment is mounted through a bolt-through hole to guide the flexible plate-shaped lance coming forward from the T-rail to be bent in a 90-degree direction. A steam generator cleaning equipment having a flexible plate structure, which prevents jams when the lance head is bent while leaving a groove. According to claim 8, The rack gear motor case, A second servomotor having an encoder and a gearhead is mounted, and the spur gear fixed to the second servomotor shaft and the rack gear of the T-rail mesh with each other to convert the rotational motion into linear motion and bolt the rail guide tensioning device. Steam generator cleaning equipment of the flexible plate-like structure characterized in that the engagement of the spur gear and the rack gear is maintained by torsional rotation together when the rail guide torsional rotation by tightening. The method of claim 9, wherein the motor case for rollers, Two servomotors with encoder and gearheads can be mounted, and a bolt hole for fixing the servomotor is provided to allow adjustment of the distance between two rollers fixed to the servomotor shaft, and fixed to the T-rail tensioning device. The steam generator cleaning equipment of the flexible plate structure characterized in that it is designed to be torsional rotation with the T-rail. The method of claim 10, wherein the lance of the flexible plate-like structure, Consisting of translucent polyurethane material, the displacement of bending up and down by thin plate is limited, and the displacement of bending left and right is generous, and the bending is induced by the bending guide of T-rail, and the internal high pressure hose and washing air injection pipe, Steam generator cleaning equipment of the flexible plate-like structure characterized in that it comprises an endoscope camera , foreign matter removal tool. The method of claim 11, wherein the lance head, By using the cleaning air inlet pipe inserted into the lance of the flexible plate structure to remove the water and foreign matter of the lens to induce the endoscope camera to secure the field of view to inspect the foreign matter present in the steam generator, Of the nozzle tips connected to the high pressure hose and spraying the high pressure water, the nozzle tip facing diagonally with respect to the direction in which the lance enters removes sludge existing between the diagonal lines of the heat pipe array , and the nozzle tip facing upward and downward is a steam generator tube. The sludge existing on the sheet removes sludge, the nozzle tip facing left and right removes sludge stuck between the rows of heat pipes, and the nozzle tip facing forward is designed to remove sludge stuck to the side of the heat pipe. Flexible plate-shaped structure having a tip and containing a universal tool for removing debris Steam generator cleaning equipment.

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