KR20250043027A - Equipment for inner cutting and fixing a heat transfer tube of a heat exchanger - Google Patents

Abstract

The present invention relates to a heat transfer tube internal cutting and fixing device, which cuts a U-tube, which is a heat transfer tube, by fixing the inside thereof, a stabilizer having a first fixing portion, a second fixing portion, and a cutting portion mounted thereon, and a control portion having a first adjusting portion, a second adjusting portion, and a cutting adjusting portion which respectively adjust and control the first fixing portion, the second fixing portion, and the cutting portion, wherein the first fixing portion is fixed to the inside of the U-tube, which is a heat transfer tube, by being adjusted and controlled by the first adjusting portion, the second fixing portion is fixed to the inside of the U-tube, which is a heat transfer tube, by being adjusted and controlled by the second adjusting portion, and the cutting portion having a diamond cutter connected to a helical gear portion is adjusted and controlled by the cutting adjusting portion to cut a portion of the U-tube, which is a heat transfer tube, where the U-tube that has been cut is required to be removed, and the U-tube portion remaining after the cutting is fixed by a stabilizer so that it does not move due to flow.

Description

{Equipment for inner cutting and fixing a heat transfer tube of a heat exchanger}

The present invention relates to a fixing device for cutting and fixing the inside of a heat transfer tube of a heat exchanger, and more particularly, to a fixing device for cutting and fixing the inside of a heat transfer tube that is placed in a location that is difficult for people and equipment to approach, such as a heat transfer tube provided in a steam generator of a power plant.

A nuclear power plant's steam generator is a facility that generates steam by transferring heat from a high-temperature, high-pressure primary fluid containing radioactivity generated in a nuclear reactor to a secondary fluid supplied to the outside of the heat transfer tube while flowing inside the heat transfer tube, and then supplying this steam to the turbine of the generator.

A typical steam generator consists of a vessel having a vertically formed tubular shell and a hemispherical channel head forming the lower portion of the tubular shell, which utilizes a plurality of U-shaped heat transfer tubes forming a tube bundle to form a heat transfer surface necessary to transfer heat from a primary fluid to vaporize a secondary fluid.

A cutting device for cutting a heating tube of a steam generator is disclosed in Korean Patent Publication No. 10-1648439.

A cutting head of a cutting device for cutting a heating tube of a steam generator is configured to have a housing configured in the shape of a pipe, a support ring attached to the housing, a cutting tool movable in the diametrical direction of the housing, and an operating shaft movably arranged in the housing.

A through-hole is formed in the housing extending diametrically, and a cutting tool is configured to move diametrically along the through-hole from the inside of the housing.

An end face positioned inside the housing is formed as an inclined surface, a cutting blade is fixed to the opposite end, and the cutting blade is formed in an arc shape so that a part of the outer circumference of the cutting blade rotates while being pressed against the inner surface of the heating tube, thereby cutting the heating tube.

And the tip of the working shaft is formed as an inclined surface, so that the holder of the cutting tool is formed to contact the inclined surface, thereby forming a configuration in which the inclined surfaces move relative to each other.

Meanwhile, a cutting device for a tubular structure is disclosed in Korean Patent Publication No. 10-1812845.

A cutting device for a tubular structure is inserted into the interior of the tubular structure and includes a cutting pipe having a flexible material end, a cutting module that is provided so as to be withdrawable inside the cutting pipe and cuts the tubular structure, and a driving module that drives the cutting module and rotates the cutting pipe.

The end of the cutting device equipped with a cutter is made flexible so that the tubular structure can be inserted whether it is straight or curved, and the cutter is automatically operated so as to improve the convenience and speed of work.

Korean Patent Registration Publication KR 10-1648439 B1 Korean Patent Publication KR 10-1812845 B1

In a conventional steam generator, each of the heat transfer tubes included in the tube bundle of the steam generator is formed of a metal tube that has excellent corrosion resistance at high temperature and high pressure. However, the heat transfer tubes may be damaged by corrosion or impact during long-term operation.

The primary fluid flowing through the heat pipes contains a high level of radioactivity, so if the heat pipes are damaged and leak this primary fluid, it would be a serious accident. Therefore, the steam generators of nuclear power plants are inspected regularly or periodically, and any damaged or aged heat pipes must be cut off and removed during such inspections.

However, since the tube bundles of the heat exchanger tubes are arranged in a dense manner and the space between the tube bundles and the tubular shell surrounding the steam generator is very narrow, there is a problem in that the heat exchanger tubes cannot be removed between the tube bundles by workers or cutting equipment.

Such tube removal operations are carried out through openings in the tube sheet at the channel head, which provides a level of space where people and workers can enter, and since the channel head is an area with a very high level of radioactivity due to the flow of highly radioactive first fluid, there is a problem in that workers cannot enter, install equipment, and perform long-term tube removal operations.

Therefore, such work had to be done by a large number of workers at short intervals to fit the workers' radiation exposure limit, so it was a task that took a considerable amount of time, and the problem arose that workers inevitably had to be exposed to radiation up to the limit.

The present invention relates to a device for cutting and fixing an internal heat pipe, which is a U-tube, by fixing the inside thereof and cutting it, the device including a stabilizer having a first fixing part, a second fixing part, and a cutting part, and a control part having a first adjusting part, a second adjusting part, and a cutting adjusting part for respectively adjusting and controlling the first fixing part, the second fixing part, and the cutting part.

The first fixing part of the present invention is fixed inside a U-tube, which is a heat transfer tube, under control by the first adjusting part, the second fixing part is fixed inside a U-tube, which is a heat transfer tube, under control by the second adjusting part, and the cutting part, which has a diamond cutter connected to a helical gear part, is configured to cut the U-tube, which is a heat transfer tube, at a portion where a tube extraction is required, under control by the cutting adjusting part.

The present invention removes a cut U-tube and secures the remaining U-tube portion after cutting with a stabilizer so that it does not move due to flow.

The first fixed part of the present invention controls the first adjusting part to expand and rotate a fixed expansion tube connected to a helical gear part and contact and fix it to the inner surface of a U tube, which is a heat transfer tube.

The second fixed part of the present invention controls the second adjusting part to expand and rotate the fixed expansion tube connected to the helical gear part, thereby contacting and fixing it to the inner surface of the U tube, which is a heat transfer tube.

The cutting section of the present invention is configured such that a helical gear section rotates and expands under control of a cutting control section, and a cutter connected to the helical gear section expands and rotates to start cutting from the inner surface of a U tube.

Since the first adjusting part of the present invention is fixed by the helical gear part rotating in only one direction, the first fixing part is configured not to loosen once it is fixed by contacting the inner surface of the U tube.

The second adjusting member of the present invention is configured to rotate in both directions, and when the second fixing member is fixed by contacting the inner surface of the U tube (200), and the helical gear member is operated in the opposite direction by the control of the second adjusting member, the diameter of the helical gear member is reduced, thereby releasing the fixation.

According to the cutting control unit of the present invention, the cutting unit can rotate in both directions, and after cutting the U tube, when it is rotated in the opposite direction, the diameter of the helical gear unit is reduced, thereby reducing the outer diameter of the cutter and stopping the cutting process.

Since the first adjusting member of the present invention rotates the helical gear member in only one direction, the first fixing member is configured such that positional movement of the first fixing member is impossible when it comes into contact with the inner surface of the U tube.

Since the helical gear part can be rotated in both directions by controlling the second adjusting part and the cutting adjusting part of the present invention, the second fixing part and the cutting part are configured to be positionally movable.

The present invention is a configuration in which a device for cutting and fixing an internal heat pipe removes a welded portion of a U-tube, which is a heat pipe, and a support plate, inserts the device into the inside of the U-tube, moves a first fixing part in front of a cutting position, controls a first adjusting part, and rotates a helical gear part to fix the first fixing part to the U-tube, which is a heat pipe.

The present invention moves a second fixing member behind a cutting position, controls a second adjusting member to expand and rotate a helical gear member to fix the second fixing member to a U tube, moves the cutting member to a cutting position, controls the cutting adjusting member to expand and rotate the helical gear member to cut the U tube with a cutter mounted on the cutting member.

By controlling the cutting control unit of the present invention, the helical gear unit is rotated in the opposite direction to reduce the cutter outer diameter, and the cut heat transfer tube (U tube) in contact with the second fixing unit is removed, and then the second fixing unit is positioned at the end of the support plate, and the second control unit is controlled to rotate the helical gear unit to fix the second fixing unit to the support plate.

The present invention is a configuration in which a stabilizer on the outer part of a support plate is cut and a second fixing part and the support plate are welded and fixed.

When the present invention partially removes a heat pipe when necessary, the support plate and the heat pipe weld are removed, a cutting tool is inserted into the heat pipe to cut the heat pipe, and the heat pipe is removed. Then, the remaining part of the heat pipe is fixed with a stabilizer so that it does not move due to flow.

Therefore, it has the advantage of being able to cut the heat transfer tube section of a U-tube type heat exchanger at an accurate location and easily fix the remaining part of the heat insulating tube.

Figure 1 is a simplified diagram of a U-tube heat exchanger composed of thousands of U-tube heat transfer tubes.
Figure 2 is a right side view of the shell of the U-tube type heat exchanger illustrated in Figure 1.
Figure 3 is a simplified illustration of the process of partially extruding a U-tube, which is a heat transfer tube, by cutting it from the inside.
FIG. 4 is a simplified diagram of an embodiment according to the present invention, which schematically illustrates a heat pipe internal cutting device having two fixing parts and one cutting part mounted on a stabilizer.
Figure 5 is a simplified diagram illustrating the operating state of a heating tube internal fixing and cutting device inside a heating tube according to the present invention.
Figure 6 schematically illustrates the configuration of the first and second fixing parts and the cutting part according to an embodiment of the present invention.
Figure 7 schematically illustrates the process in which a fixed expansion tube (60) connected to a helical gear section expands and comes into contact with the inner surface of a U tube (200).
Figure 8 schematically illustrates the configuration of a diamond cutter (70) connected to a helical gear portion (80).
Figure 9 is a schematic diagram showing the process of removing a heat pipe using a heat pipe internal cutting and fixing device.

Hereinafter, the configuration and operation of a preferred embodiment of the present invention will be described with reference to the attached drawings.

Figure 1 is a simplified diagram of a U-tube heat exchanger composed of thousands of U-tube heat transfer tubes.

Inside the shell (100) of the U-tube type heat exchanger, the main components are provided: a U-tube heat exchanger (200), which is a heat transfer tube; tube supports (300); a support plate (400); and tie rods and spacers (500).

Hereinafter, “U tube heat exchanger (200)” or “U tube (200) as heat transfer tube” are collectively referred to as “U tube (200)”.

The superheated steam zone of the U-tube type heat exchanger (200) is provided with desuperheating zone baffles (610) and desuperheating zone shrouds (620) to prevent overheating.

The drain area of the U-tube type heat exchanger is provided with a drain subcooling zone enclosure (630) and drain subcooling zone baffles (640) to prevent subcooling.

Cooling water is introduced into the feedwater inlet (710) through a channel (700) and discharged to the feedwater outlet (720).

The shell (100) of the U-tube type heat exchanger is provided with a drain inlet (810), a drain outlet (820), a steam inlet (840), and a heater support.

Figure 2 is a right side view of the shell of the U-tube type heat exchanger illustrated in Figure 1.

Figure 2 is a right side view taken from “A” of Figure 1, in which U tubes (200) are welded and fixed to a support plate (400).

The U tube (200) installed inside the shell of the U tube type heat exchanger is configured such that the water inlet (710) of the U tube (200) is installed at the bottom and the water outlet (720) is installed at the top by a partition (410).

Therefore, the U-tube type heat exchanger has a configuration in which water supplied to the U-tube (200) water inlet (710) arranged at the bottom of the shell is introduced and discharged to the U-tube (200) water outlet (720) arranged at the top.

The water inlet (710) and the water outlet (720) of the U tube (200) are configured to be welded and fixed to the end of the support plate (400).

The water inlet (710) and the water outlet (720) of the U tube (200) are shown as having a configuration in which they form a weld (730) that is welded and fixed to the support plate (400).

Figure 3 is a simplified illustration of the process of partially extruding a U-tube, which is a heat transfer tube, by cutting it from the inside.

FIG. 3 is an enlarged view of part “B” showing a configuration in which a tube cutting device is installed to cut a U tube (200) installed inside a shell (100) of a U tube-type heat exchanger of FIG. 1.

The process for removing the heat transfer tube portion installed in the shell of a U-tube heat exchanger as needed is as follows.

① Remove the welded joint between the support plate and the heating tube.

② Insert a cutting tool into the U tube, which is a heat transfer tube.

Cut the heating tube into pieces.

③ Remove the cut heating tube.

④ Secure the stabilizer/support plate so that the remaining part of the heat pipe does not move due to the flow.

Figure 3 shows the process of exsanguination of ① → ② → ③ → ④.

FIG. 4 is a simplified diagram of an embodiment according to the present invention, which schematically illustrates a heat pipe internal cutting device having two fixing parts and one cutting part mounted on a stabilizer.

A heat pipe internal fixing and cutting device (900) that cuts a heat pipe by fixing it internally to a U tube (200) is composed of a first fixing part (10), a second fixing part (20), a cutting part (40), and a stabilizer (40).

The stabilizer (40) is equipped with a first fixing part (10), a second fixing part (20), and a cutting part (30).

The control unit (50) that controls the first fixed part (10), the second fixed part (20), and the cutting part (30) respectively is composed of a first adjusting part (11), a second adjusting part (21), and a cutting adjusting part (31).

The first fixed part (10) is controlled by the first adjusting part (11) and is fixed inside the U tube (200), which is a heat transfer tube.

The second fixed part (20) is controlled by the second adjusting part (21) and is fixed inside the U tube (200), which is a heat transfer tube.

The cutting section (30) is controlled by the cutting control section (31) to cut the U tube (200) in the section where the tube needs to be removed inside the U tube (200), which is a heat transfer tube.

Figure 5 is a simplified diagram illustrating the operating state of a heating tube internal fixing and cutting device inside a heating tube according to the present invention.

The support plate (400) and the welded portion (730) are removed, and a heat pipe internal fixing and cutting device (900) having a first fixing portion (10), a cutting portion (30), and a second fixing portion (20) mounted on a stabilizer (40) for tube insertion is inserted into the U tube (200), which is a heat pipe.

The first fixed part (10) is configured to be connected to a fixed expansion pipe (60) that expands by rotation of the helical gear part, controlled by the first adjusting part (11).

It is configured to control the first control unit (11) so that the fixed expansion tube (60) connected to the helical gear rotates and contacts and fixes the inner surface of the U tube (200), which is a heat transfer tube.

Since the first adjusting part (11) is fixed by the helical gear part rotating in only one direction, the first fixing part is configured to not loosen once it is fixed by contacting the inner surface of the U tube (200).

The second fixed part (20) is configured to have a fixed expansion pipe (60) connected to the rotating helical gear part and expanded under the control of the second adjusting part (21).

The second control unit (21) is controlled so that the fixed expansion tube (60) connected to the helical gear unit and expanded rotates and is fixed by contacting the inner surface of the U tube (200), which is a heat transfer tube.

The second adjusting member (21) is configured to rotate in both directions, and after the second fixing member (20) is fixed by contacting the inner surface of the U tube (200), when the helical gear member is operated in the opposite direction by the control of the second adjusting member (21), the diameter of the helical gear member is reduced, thereby releasing the fixation.

The cutting section (30) is equipped with a diamond cutter (70) connected to a helical gear section.

By controlling the cutting control unit (31), the helical gear unit rotates and expands, and the cutter (70) connected to the gear rotates and cuts the heating tube.

By controlling the cutting control unit (31) of the cutting unit (30), the diameter of the helical gear unit is expanded, and accordingly, the cutter (60) starts cutting from the inner surface of the U tube (200).

The cutting part (30) can be rotated in both directions by the cutting control part (31), and after cutting the U tube (200), when it is rotated in the opposite direction, the diameter of the helical gear part is reduced, thus reducing the outer diameter of the cutter (70), thereby stopping the cutting process.

Since the first adjusting part (11) rotates the helical gear part in only one direction, movement of the first fixed part (10) is impossible when the first fixed part (10) comes into contact with the inner surface of the U tube (200).

The helical gear part is rotated in both directions by the control of the second control part (21) and the cutting control part (31), and as a result, the second fixed part (20) and the cutting part (30) are configured to be positionally movable.

Figure 6 schematically illustrates the configuration of the first and second fixing parts and the cutting part according to an embodiment of the present invention.

Figure 6(a) is a cross-sectional view of the first fixed part (10), showing the process of expanding the fixed expansion pipe (60) connected to the helical gear part that rotates under the control of the first adjusting part (11).

The gear (60) shown on the inside of Fig. 6(a) shows the configuration before the gear is expanded, and the gear (60) shown on the outside shows a state in which the gear is expanded and the expansion tube (60) is fixed by contacting the inner surface of the U tube (200), which is a heat transfer tube.

The gear of the first fixed part (10) can only rotate in one direction.

Figure 6(b) is a cross-sectional view of the second fixed part (20), showing the process of the fixed expansion pipe (60) connected to the helical gear part that rotates under the control of the second adjusting part (21) expanding and contracting.

The gear (60) shown on the inside of Fig. 6(b) shows the configuration before the gear is expanded, and the gear (60) shown on the outside shows a state in which the gear is expanded and the expansion tube (60) is fixed by contacting the inner surface of the U tube (200), which is a heat transfer tube.

The helical gear part of the second fixed part (20) can rotate in both directions.

Fig. 6(c) is a cross-sectional view of a cutting section (30), showing the process in which a diamond cutter (70) connected to a helical gear section that rotates under the control of a cutting control section (31) expands and contracts.

The gear (60) shown on the inside of Fig. 6(c) shows the configuration before the gear is expanded, and the gear (60) shown on the outside shows a state in which the helical gear part is expanded and comes into contact with the inner surface of the U tube (200), which is a heat transfer tube of the diamond cutter (70), to start cutting.

Figure 7 schematically illustrates the process in which a fixed expansion tube (60) connected to a helical gear section expands and comes into contact with the inner surface of a U tube (200).

The first and second fixed parts are fixed by being inserted and expanded into the interior of the fixed expansion tube (60) connected to the helical gear part (80) and coming into contact with the inner surface of the U tube (200).

Figure 8 schematically illustrates the configuration of a diamond cutter (70) connected to a helical gear portion (80).

Figure 9 is a schematic diagram showing the process of removing a heat pipe using a heat pipe internal cutting and fixing device.

Remove the welded portion of the U-tube, which is a heat transfer tube, and the support plate, and insert the internal cutting and fixing device of the U-tube, which is a heat transfer tube, into the inside of the heat transfer tube.

The first fixing part (10) is moved forward of the cutting position, and the first adjusting part (11) is controlled to expand and rotate the helical gear part, thereby fixing the first fixing part (10) to the U tube (200), which is a heat transfer tube.

The second fixing part (20) is moved to the rear of the cutting position, and the second adjusting part (21) is controlled to expand and rotate the helical gear part, thereby fixing the second fixing part (21) to the U tube (200), which is a heat transfer tube.

The cutting part (30) is moved to the cutting position, and the cutting control part (31) is controlled to expand and rotate the helical gear part, thereby cutting the U tube (200) with the cutter (70) mounted on the cutting part (30).

By controlling the cutting control unit (31), the helical gear unit is rotated in the opposite direction to reduce the outer diameter of the cutter (70) and remove the U tube (200), which is a cut heat transfer tube in contact with the second fixing unit (20).

Next, the second fixed part (20) is positioned at the end of the support plate (400), and the second adjusting part (21) is controlled to rotate the helical gear part to fix the second fixed part (20) to the support plate (400).

The stabilizer (40) on the outer part of the support plate (400) is cut, and the second fixing part (20) and the support plate (400) are welded and fixed to complete the work.

Although the present invention has been described in detail through representative examples above, those skilled in the art will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention.

Therefore, the scope of the rights of the present invention should not be limited to the described embodiments, but should be determined by all changes or modifications derived from the claims described below as well as the equivalent concepts of the claims.

10: 1st fixed part
11: 1st Control Section
20: Second fixed part
21: Second Control Unit
30: Cut section
31: Cutting control section
40: Stabilizer
50: Control Unit
60: Fixed extension tube
70: Diamond Cutter
80: Helical gear section
100: Shell of U-tube type heat exchanger
200: U tube (heat conductor)
400: Support plate
730: Welding

Claims (5)

The internal cutting and fixing device (900) for cutting and fixing the internal part of the U tube (200), which is a heat pipe, is
A stabilizer (40) equipped with a first fixing part (10), a second fixing part (20) and a cutting part (30), and
It includes a control unit (50) having a first adjusting unit (11), a second adjusting unit (21), and a cutting adjusting unit (31) that control the first fixing unit (10), the second fixing unit (20), and the cutting unit (30), respectively.
The first fixed part (10) is controlled by the first adjusting part (11) and is fixed inside the U tube (200), which is a heat transfer tube.
The second fixed part (20) is controlled by the second adjusting part (21) and is fixed inside the U tube (200), which is a heat transfer tube.
The cutting section (30) equipped with a diamond cutter (70) connected to the helical gear section is controlled by the cutting control section (31) to cut the U tube (200) in the section where the tube needs to be removed inside the U tube (200), which is a heat transfer tube.
Remove the cut U tube (200),
A device for cutting and fixing the inside of a heat pipe, characterized in that the remaining U tube (200) portion after cutting is fixed with a stabilizer (40) so that it does not move due to flow.
In the first paragraph,
The first fixed part (10) controls the first adjusting part (11) so that the fixed expansion tube (60) connected to the helical gear part expands and rotates and is fixed by contacting the inner surface of the U tube (200), which is a heat transfer tube.
The second fixed part (20) controls the second adjusting part (21) so that the fixed expansion tube (60) connected to the helical gear part expands and rotates, and is fixed by contacting the inner surface of the U tube (200), which is a heat transfer tube.
A cutting and fixing device for an internal heat pipe, characterized in that the cutting unit (30) controls the cutting control unit (31) so that the cutter (70) connected to the expanding rotating helical gear unit starts cutting from the inner surface of the U tube (200).
In the second paragraph,
Since the first adjusting part (11) is fixed by the helical gear part rotating in only one direction, the first fixing part is configured not to be released when fixed by contacting the inner surface of the U tube (200).
The second adjusting part (21) is configured to rotate in both directions, and after the second fixing part (20) is fixed by contacting the inner surface of the U tube (200), when the helical gear part is operated in the opposite direction by the control of the second adjusting part (21), the diameter of the helical gear part is reduced and the fixation is released.
A cutting and fixing device inside a heat pipe characterized in that the cutting part (30) can rotate in both directions by the cutting control part (31), and after cutting the U tube (200), when it is rotated in the opposite direction, the diameter of the helical gear part is reduced, thereby reducing the outer diameter of the cutter (70) and stopping the cutting process.
In the third paragraph,
Since the first adjusting part (11) rotates the helical gear part in only one direction, when the first fixed part (10) comes into contact with the inner surface of the U tube (200), the positional movement of the first fixed part (10) is impossible.
A heat pipe internal cutting and fixing device characterized in that the second fixing part (20) and the cutting part (30) are configured to be positionally movable, so that the helical gear part can be rotated in both directions by the control of the second adjusting part (21) and the cutting adjusting part (31).
By using the policy according to any one of the clauses 1 to 4,
Cut and fix the inside of the heat pipe Remove the welded part of the heat pipe U tube and the support plate and insert it into the inside of the U tube.
Move the first fixing part (10) forward of the cutting position, control the first adjusting part (11) to expand and rotate the helical gear part, and fix the first fixing part (10) to the U tube (200), which is a heat transfer tube.
The second fixing part (20) is moved to the rear of the cutting position, and the second adjusting part (21) is controlled to expand and rotate the helical gear part to fix the second fixing part (21) to the U tube (200).
The cutting part (30) is moved to the cutting position, and the cutting control part (31) is controlled to expand and rotate the helical gear part to cut the U tube (200) with the cutter (70) mounted on the cutting part (30).
By controlling the cutting control unit (31), the helical gear unit is rotated in the opposite direction to reduce the outer diameter of the cutter (70), and the U tube (200), which is a cut heat pipe in contact with the second fixing unit (20), is removed.
Next, the second fixing part (20) is positioned at the end of the support plate (400), and the second adjusting part (21) is controlled to rotate the helical gear part to fix the second fixing part (20) to the support plate (400).
A method for cutting and fixing the inside of a heat pipe, characterized by cutting a stabilizer (40) on the outer part of a support plate (400) and fixing the second fixing part (20) and the support plate (400) by welding them.