KR100416415B1 - Non-welding sleeve expander for steem generater of nuclear generator - Google Patents

Abstract

The present invention relates to an expansion device for expanding and coupling a sleeve for a heat pipe of a nuclear power plant steam generator to a heat pipe using an expansion tool,

A high pressure water supply control device controlling a high pressure water supply with a high pressure hose;

And a display control unit for outputting the control data of the high-pressure water supply control device to the display;

The high pressure water supply control device is configured to generate water pressure in the high pressure hose connected to the expansion tool in conjunction with the expansion of the first cylinder and the cylinder rod in response to the operation of the servo valve controlling the hydraulic pump output. Two cylinders, a displacement gauge for recognizing the telescopic displacement of the cylinder rod, a pressure gauge for detecting the hydraulic pressure, and an expansion controller for controlling servo valves and converting analog data of the displacement gauge and the pressure gauge into digital data;

The display control unit is a non-contact sleeve expansion device, characterized in that coupled to the computer main body to receive the expansion data of the expansion control unit to recognize and analyze the output pressure and deformation amount to the computer monitor.

Description

Non-welding sleeve expander for steem generater of nuclear generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact sleeve expansion device for steam generators, and more particularly to a sleeve expansion device that enables precise expansion control by using expansion of the expansion tool to control displacement of the piston.

A nuclear power plant uses a steam generator that circulates secondary coolant inside a heat pipe to generate superheated steam so that there is no fear of contamination (Domestic Patent Registration No. 10-0286515). The safety of steam generator heat pipes in nuclear power plants is extremely important because the primary side water of the PWR nuclear power plant is contaminated with radioactivity while the secondary side water is contaminated. It is desirable to prevent these two sides of water from mixing with each other. Such a steam generator is composed of a plurality of heat pipes in the U-shaped form a configuration that is coupled to both ends of the tube sheet. However, if some of the heat pipes are damaged, the first leak of the nuclear power plant accident occurs to solve this problem is often checked to block the entrance of the damaged heat pipes among the heat pipes forming the steam generator (US Patent Nos. 4502511, 4513786). Clogging both ends of the heat pipes effectively removes the corresponding heat pipes from operation, and only decreases the efficiency of the remaining steam generators. Therefore, in recent years, the auxiliary sleeve is welded to the damaged heat pipe, and only the damaged part of the heat pipe is locally maintained. Such a sleeve may be welded to a heat pipe, brazed, rolled using a mechanical roll, or installed using multiple stages of hydraulic expansion.

As an example of welding the sleeve, as shown in FIG. 1, the end of the U-shaped heat pipe 1 is fixedly coupled to the tube sheet 3 (only one end of the U-shaped heat pipe is shown in the drawing), and the portion P of the damaged heat pipe 1 is shown. ) Is used to maintain the function of the damaged heat pipe 1 by welding the heat pipe 1 and the sleeve 2 by fitting the sleeve 2. However, the welding part may be broken again and the welding may be unreliable due to poor welding. In addition, the technique of repairing the damaged heat pipes by expanding the sleeves to partially expand the heat pipes and the sleeves integrally inserts a sleeve 2 having a smaller diameter than the heat pipes in the heat pipes 1 to be repaired, as shown in FIG. The expansion part 6 is inserted into the expansion tool 20 by inserting the expansion tool 20 which is also slightly smaller in diameter than the sleeve, and supplying the high pressure water 5 through the high pressure hose 4 to expand the expansion tool 20. The heat transfer pipe 1 and the sleeve 2 are partially expanded to achieve this.

Expansion pipe tool 20 is an inner tube that forms a high-pressure water passage 22 and supports a coupling 21 for coupling the high-pressure hose 4 and the nozzle groove 23 on the outer circumference. (24), a stretchable band-shaped elastic ring (25) surrounding the nozzle groove (23), and an inner tube (24) to block longitudinal movement of the inner tube (24) at both ends of the elastic ring (25). Metal bands 26 and 27 fitted to the outer periphery, and guide head 28 coupled to the distal end of the inner tube 24 to guide the insertion of the expansion pipe tool 20. A1 is a space between the expansion ring 25 and the sleeve 2, and a2 is a space between the sleeve 2 and the heat pipe 1.

When using this, the sleeve 2 is inserted into the repair part of the heat exchanger tube 1, and the expansion pipe tool 20 is fitted to the inner diameter part of the sleeve 2 as shown in FIG. Subsequently, the high pressure water 5 through the pressure generating means (not shown) is supplied to the inner tube 24 through the high pressure hose 4 to the coupling 21. Then, the high pressure water is supplied through the high pressure water passage 22 and the nozzle groove 23 of the inner tube 24, and thus the expansion ring 25 is stretched by the pressure of the high pressure water. As the elastic ring 25 is stretched, the sleeve 2 and the heat pipe 1 are simultaneously expanded to a predetermined diameter as shown in FIG. 2.

However, this method expands and expands the elastic ring 25 by providing a constant pressure and thus expands and contracts the sleeve 2 and the heat pipe 1, so that expansion is possible, but there is a limit to obtaining accurate pressure and expansion rate. have. In addition, there is a problem that it is difficult to ensure the stability of the sealing property because it is difficult to accurately expand. In other words, when a tube is expanded by unilaterally applying a constant pressure, when the material of the tube is constant as in a laboratory, the same degree of expansion can be obtained at all times. According to the change of material (deterioration) or the change of heat pipe size due to corrosion, cracking, etc., the degree of tube expansion is different. More specifically, when the sleeve 2 is mounted on the heat pipe 1, the sleeve 2 always has a certain material (strength) and dimensions because it is newly manufactured, but the steam generator has been used for a long time and has a defect. The heat exchanger tube 1 of the heat exchanger, such as a condenser, is hardened or deteriorated with a long time of use, or its dimensions change due to corrosion or cracking. When the material of the heat pipe 1 is hardened, unlike the sleeve 2 that can always maintain the same material when the pipe pressure determined in the laboratory is applied, the degree of expansion is less than that of the heat pipe 1 used in the laboratory. . If the expansion amount is smaller than expected, it becomes difficult to maintain the airtightness between the sleeve 2 and the heat exchanger tube 1. On the other hand, assuming that the heat transfer pipe (1) material is softened (when the strength drops), when the expansion pressure determined in the laboratory is applied, the heat transfer pipe (1) is expanded in the laboratory, so the residual stress of the expansion pipe portion is greatly increased Will remain. Since the residual stress in the expansion pipe causes bad corrosive properties, there is a possibility that the lifetime of the heat transfer pipe 1 is shorter than expected by the sleeve 2 provided. In general, the heat transfer pipe (1) is used in a corrosive environment, and as the use time becomes longer, its thickness becomes thin. When the expansion pressure determined in the laboratory is applied, the thickness becomes thinner, and thus the degree of expansion becomes smaller than expected. As with softened materials, the corrosive properties deteriorate. Therefore, the change in the material (strength of the use tube) or the size is different from the expected expansion amount in the laboratory when the expansion pressure determined in the laboratory, there is a problem that does not obtain a healthy fastening state.

SUMMARY OF THE INVENTION The present invention seeks to address this, and an object of the present invention is to provide a sleeve expansion device that enables precise expansion control by using expansion of the expansion tool to control the displacement of the piston.

To this end, the expansion apparatus of the present invention includes a high pressure means control device including a first cylinder for generating pressure and a second cylinder interlocked with the first cylinder, and a displacement gauge and a piston for recognizing piston displacement of the high pressure means control device. The numerical value through the pressure gauge is configured to be recognized by the display control unit.

1 is a cross-sectional view showing a sleeve installed in the heat transfer tube of a general nuclear power plant steam generator,

Figure 2 is a cross-sectional view showing a state in which the expansion tool for expansion pipe is inserted into the sleeve after the general sleeve is inserted into the heat transfer pipe,

3 is a cross-sectional view showing a state of expansion using the expansion tool shown in FIG.

4 is a block diagram of the present invention,

5 is a graph showing a correction concept of the present invention;

6 is a graph showing the relationship between the cylinder rod movement distance and the generated pressure according to the cylinder rod operation of the cylinder of the present invention.

Explanation of symbols for the main parts of the drawings

1; heat pipe 2; sleeve

4; high pressure hose 5; high pressure water

6; expansion unit 20; expansion tool

21; coupling 22; high pressure water passage

23; nozzle groove 24; inner pipe

25; expansion ring 26, 27; metal band

28; guide head 30; high pressure water supply control device

31a; hydraulic pump section 34; first cylinder

34-1; cylinder rod 35; servovalve

36; second cylinder 37; water tank

38; pressure gauge 39; displacement gauge

40; expansion controller 44; display controller

50; display

In other words, the present invention is the expansion device for expanding and coupling the sleeve for the heat pipe of the nuclear power plant steam generator using the expansion tool,

A high pressure water supply control device controlling a high pressure water supply with a high pressure hose;

And a display control unit for outputting the control data of the high-pressure water supply control device to the display;

The high pressure water supply control device is configured to generate water pressure in the high pressure hose connected to the expansion tool in conjunction with the expansion of the first cylinder and the cylinder rod in response to the operation of the servo valve controlling the hydraulic pump output. Two cylinders, a displacement gauge for recognizing the telescopic displacement of the cylinder rod, a pressure gauge for detecting hydraulic pressure, and an expansion controller for controlling servo valves and converting analog data of the displacement gauge and the pressure gauge into digital data;

The display control unit is provided with a non-contact sleeve expansion unit coupled to the computer main body to receive the expansion data of the expansion control unit to recognize and analyze the output pressure and deformation amount to the computer monitor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

4 is a configuration diagram of the present invention, in the expansion device for expanding and coupling the sleeve for the heat pipe of the nuclear power plant steam generator using the expansion tool,

A high pressure water supply control device 30 for controlling the high pressure water supply to the high pressure hose 4;

And a display control section 44 for outputting control data of the high pressure water supply control device 30 to the display 50;

The high pressure water supply control device 30 includes a first cylinder 34 which expands and contracts the cylinder rod 34-1 according to the operation of the servovalve 35 that controls the hydraulic output of the hydraulic pump unit 31a; In response to the expansion and contraction of the cylinder rod 34-1, the expansion and contraction displacement of the second cylinder 36 and the cylinder rod 34-1 generating hydraulic pressure to the high pressure hose 4 connected to the expansion tool 20 can be obtained. A displacement controller 39 for recognizing, a pressure gauge 38 for recognizing water pressure, and an expansion controller 40 for controlling the servovalve 35 and converting analog data of the displacement gauge 39 and the pressure gauge 38 into digital data. Done;

The display control unit 44 receives the expansion data of the expansion control unit 40, recognizes and analyzes the expansion data, and couples it to the computer main body 45 to output water pressure and deformation amount to the display 50, which is a computer monitor.

The hydraulic pump part 31a is cooled by a motor 31 that provides rotational force, a cooling fan 32 that cools heat generated by the rotational force of the motor 31, and a cooling fan 32. It can be exemplified as consisting of a hydraulic pump 33 for generating a hydraulic pressure by the rotational force may be used that are integrally coupled in one housing.

Numeral 37 is made to supply the hydraulic pressure of the cylinder of the second cylinder 36 to the water tank. Reference numeral 41 is a coupling for connecting the high pressure hose 4 and the hydraulic pressure output portion of the second cylinder 36 so that high pressure water can be supplied to the high pressure hose 4. Reference numeral 42 is a data line for exchanging data between the expansion control unit 40 and the display control unit 44. The cylinder rod 34-1 of the first cylinder 34 expands and contracts according to the valve action of the servovalve 35, and the cylinder rod 34-1 expands and contracts the cylinder of the second cylinder 36. The water pressure of the water 37-1 accommodated in the cylinder hole 36-2 in the housing 36-1 is adjusted. Reference numeral 36-3 is a water pressure discharge hole of water 37-1. Of course, the water tank 37 supplies the water 37-1 to the cylinder housing 36-1 to be placed above the cylinder housing 36-1 to achieve a constant water pressure.

The pressure graph appearing on the monitor 50 shows the primary pressure increasing portion 46a, which shows that the expansion capacity is increased by the space a1 of FIG. 2 when the hydraulic pressure is applied to the expansion ring 25, and the expansion ring ( 25, the primary horizontal portion which is further expanded with the sleeve (2) together with the sleeve (2) so that the inner surface of the heat transfer pipe (1) is in contact with the outer peripheral surface of the sleeve (2) of the expansion portion (6). 46b) and the continuous expansion of the expansion ring 25 simultaneously increases the pressure and the expansion amount so that the expansion ring 25, the sleeve 2 and the heat transfer pipe 1 are simultaneously expanded, and the sleeve 2 and the heat transfer pipe 1 are A graph curve of the secondary horizontal portion 46d in which the elastically expanded secondary pressure increasing portion 46c and the plastic deformation of the heat transfer pipe 1 and the sleeve 2 are made and the amount of expansion is relatively increased compared to the increase in pressure. (46). In the drawing, reference numeral 47 denotes a secondary pressure increase line forming a simultaneous expansion of the heat transfer pipe 1 and the sleeve 2, 48 denotes a plastic deformation line at the time of plastic deformation, and p1 denotes an expansion completion point.

In the present invention configured as described above, the motor 31 is driven in a state in which the high-pressure water supply control device 30 and the display control unit 44 are connected to the line 42 and power is applied (not shown in the power supply means). The cooling fan 32 and the pump 33 are driven to operate the hydraulic pump part 31a. Then, the hydraulic pressure through the pump 33 is supplied to the first cylinder 34 forming the primary booster through one output terminal T1 of the servovalve 35. The hydraulic pressure applied to the first cylinder 34 extends the cylinder rod 34-1 to push the water deposited in the cylinder hole 36-2 of the second cylinder 36 to increase the pressure. In this case, the hydraulic oil applied to the first cylinder 34 may be, for example, a product (Mobile DTE24). The fluid used for the second cylinder 36 is directly used to expand the expansion ring 25, the sleeve 2 and the heat transfer pipe 1, and uses distilled water that does not cause contamination even if leaked. Supply through the tank (37). The principle of the present invention is to control the generation of pressure and thus the expansion of the sleeve 2 by calculating the distance traveled by the cylinder rod 34-1 of the pressure generating cylinder 34,

First, the inner diameter (cylinder hole 36-2 in FIG. 4) of the second cylinder 36 for secondary boosting is represented by a letter Ri, and the distance that the cylinder rod 34-1 moves is represented by a letter L. If the extension length of a tube (for example, the heat transfer tube 1) is letter (l), the diameter of the tube after expansion is letter (df), and the diameter of the tube before expansion is letter (do), the cylinder rod ( Since the volume generated when 34-1) moves the cylinder hole 36-2 should be equal to the volume change generated by expansion, that is, the volume change caused by the movement of the piston is the volume of the tube before expansion from the volume change of the expanded volume. Can be expressed as the subtracted value. This can be represented by the following equation.

Here, the letter Ri and the letter l are constant, so think of it as a constant.

I want to know because I'm watching. In addition, in the present invention, the second cylinder 36 and the expansion tool 20 are connected to the high pressure hose 4, and since the distilled water also has a compression ratio, the volume change (expansion) and the distilled water according to the pressurization of the high pressure hose (4). The extrusion rate of and the compression rate of the expansion ring 25 used in the expansion tool 20 should also be considered as an offset value. Therefore, the expansion control unit 40 adjusts the operating time, direction, and strength of the servo valve 35 through the terminal T3. That is, before setting the value for expansion, preferred examples include the expansion of the high pressure hose 4, the compression ratio of the water 37-1, and the polyurethane expansion ring 25 used in the expansion tool 20 as shown in FIG. In order to correct the compression ratio, etc.), the expansion tool is installed inside the tube so that expansion does not occur, and the correction curve 112 is obtained (conceptually shown), and the correction curve is obtained from the expansion tube 111 of the actual tube. By subtracting the pressure displacement curve 113 in the actual expansion pipe. According to this principle, the control unit 40 stores the data in the form of a database in order to adjust the material and pressure corresponding to the values corresponding to the curves 111, 112, and 113 and analyze the obtained data. That is, the extent of expansion Since is a function of the distance L traveled by the piston, the present invention is intended to be able to know the amount of expansion based on this equation by monitoring the travel distance of the piston. In addition, in the present invention, the second cylinder 36 and the expansion tool 20 are connected to the high pressure hose 4, and since the distilled water also has a compression ratio, the volume change (expansion) and the distilled water according to the pressurization of the high pressure hose (4). The extrusion rate of and the compression rate of the expansion ring 25 used in the expansion tool 20 should also be considered as an offset value. Therefore, the expansion control unit 40 adjusts the operating time, direction, and strength of the servo valve 35 through the terminal T3. That is, before setting the value for expansion, preferred examples include the expansion of the high pressure hose 4, the compression ratio of the water 37-1, and the polyurethane expansion ring 25 used in the expansion tool 20 as shown in FIG. In order to correct the compression ratio, etc.), the expansion tool is installed inside the tube so that expansion does not occur, and the correction curve 112 is obtained (conceptually shown), and the correction curve is obtained from the expansion tube 111 of the actual tube. By subtracting the pressure displacement curve 113 in the actual expansion pipe. According to this principle, the control unit 40 stores the data in the form of a database in order to adjust the material and pressure corresponding to the values corresponding to the curves 111, 112, and 113 and analyze the obtained data.

The movement distance of the cylinder rod 34-1, which moves the cylinder hole 36-2 of the second cylinder 36, is determined by the displacement meter 39 and sent to the controller 40 and the display controller 44. To be recognized through the display 50. In addition, the water pressure generated in the second cylinder 36 is recognized by the pressure gauge 38, and also through the expansion control unit 40 and the display control unit 44 to analyze and compare the data and output it to the display 50. Therefore, it is possible to overcome the difference in the amount of expansion resulting from the change in material and tube thickness that may occur when expanding at a certain pressure. For example, the maximum pressure for expansion is 1600 so that the Inconel 690 and Inconel 800 sleeves (2) can be mounted on Inconel 600, Inconel 690, and Incolo 800 heat pipes (1) commonly used in nuclear power plant steam generators. Illustrating the generation of pressure up to a bar. In order to achieve such a high pressure, the present invention operates the first and second cylinders 34 and 36 by using the hydraulic pump part 31a, and manufactures the pressure above the required pressure (for example, 2000 bar) for safety. In addition, in the present invention, in order to accurately analyze the degree of tube expansion, the displacement value (Stroke (mm)) of the displacement gauge 39 shown in FIG. 4 and the pressure (bar) change through the pressure gauge 38 are shown on the display. It may be specifically illustrated as shown in FIG. 6.

That is, in the pressure and displacement curves appearing when the sleeve 2 and the heat transfer pipe 1 are expanded, the expansion ring 25 shown in FIGS. 2 and 3 is the space a1 as shown in the pressure increase curve of the primary pressure increasing portion 46a. It can be seen that it is a process of expanding through the) to reach the inner surface of the sleeve (2), in the primary horizontal portion (46b) it can be seen that the process of expanding the sleeve (2) by expansion of the expansion ring (25). (The inclination 122 shown by the dotted line is the line which has the same inclination as the primary horizontal part 46b, and means the inclination of the baking area of the sleeve 2). In addition, the point 129 means a point at which the outer circumferential surface of the sleeve 2 reaches the inner surface of the heat pipe 1 after passing through the space a2 with the heat pipe 1 after plastic deformation. (Slope 123 is a line having the same slope as the secondary pressure increasing portion 46c means the slope of the elastic region of the heat transfer pipe 1). In this state, as the pressure increases, the expansion ring 25, the sleeve 2 and the heat transfer pipe 1 are simultaneously expanded together with the secondary pressure increasing portion 46c (in this case, the slope 124 is the secondary pressure increasing portion 46c). It is a line having a slope parallel to the slope of, indicating the slope of the plastic inverse of the heat pipe (1). Therefore, the point 130 refers to the point where the plastic deformation of the heat transfer pipe 1 is made and the expansion pipe is completed. However, in the present invention, an accurate expansion value can be obtained by setting an offset value in consideration of the strength of the sleeve 2 or the heat pipe 1 and the expansion of the high pressure hose 4 based on the basis of the curve. That is, the distance moving from the slope 123 to the slope 124 is in fact based on the distance traveled by the cylinder rod 34-1 of the first cylinder 34. In this way, when the expansion control unit 40 sends a control signal to the terminal T2 at the curved position forming the point 130 to remove the pressure by operating the servo valve 35, the heat transfer pipe 1 is in a plastically deformed state. The sleeve 2 and the heat pipe 1 are expanded as shown in FIG. 3 (expanded from the diameter do to the diameter df) to maintain the expanded state.

The present invention described above is not limited to the above-described embodiments and drawings, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those who have

As described above, the present invention always obtains a constant expansion degree regardless of material deterioration degree or dimensional change of the heat transfer tube in the expansion operation of the sleeve and the heat transfer tube for expansion installation and repair of the heat exchanger tube forming a heat exchanger such as a steam generator, a condenser, etc. of a nuclear power plant. It becomes possible. In other words, regardless of the state of the heat pipe can obtain a constant amount of expansion always expands under the same conditions and can be installed in a stable sleeve.

Claims (1)

In the expansion device for expanding the heat pipe tube sleeve of the nuclear power plant steam generator pipe expansion tool, A high pressure water supply control device controlling a high pressure water supply with a high pressure hose; And a display control unit for outputting the control data of the high-pressure water supply control device to the display; The high pressure water supply control device is configured to generate water pressure in the high pressure hose connected to the expansion tool in conjunction with the expansion of the first cylinder and the cylinder rod in response to the operation of the servo valve controlling the hydraulic pump output. Two cylinders, a displacement gauge for recognizing the telescopic displacement of the cylinder rod, a pressure gauge for detecting the hydraulic pressure, and an expansion controller for controlling servo valves and converting analog data of the displacement gauge and the pressure gauge into digital data; And the display control unit is coupled to the computer main body to receive the expansion data of the expansion control unit, recognize and analyze the expansion data, and output water pressure and deformation amount to the computer monitor.