CN117705954A

CN117705954A - Automatic ultrasonic detection device for bent pipe of heat transfer pipe of steam generator

Info

Publication number: CN117705954A
Application number: CN202311532312.2A
Authority: CN
Inventors: 陶铸; 刘云; 滕木; 王玉倩; 吴化峰; 柯涛
Original assignee: China Nuclear Power Operation Technology Corp Ltd
Current assignee: China Nuclear Power Operation Technology Corp Ltd
Priority date: 2023-11-17
Filing date: 2023-11-17
Publication date: 2024-03-15

Abstract

The invention provides an automatic ultrasonic detection device for a heat transfer tube of a steam generator, which is characterized by comprising a motor driving assembly, a front sealing assembly, a rear sealing assembly and an ultrasonic probe assembly, wherein the motor driving assembly is provided with a sliding brush for transmitting ultrasonic signals to an ultrasonic cable fixed at the rear end by an ultrasonic probe moving at the front end and a motor assembly for providing power, the front sealing assembly is arranged in front of the motor driving assembly, the rear sealing assembly is arranged behind the motor driving assembly, and the ultrasonic probe assembly is arranged in front of a corrugated tube assembly and is used for detecting a heat transfer tube bending region. The detection device is used for detecting the bent pipe section of the heat transfer pipe, and the flexible ultrasonic probe assembly is used for guaranteeing the accessibility of equipment so as to guarantee the full coverage of ultrasonic detection of the heat transfer pipe.

Description

Automatic ultrasonic detection device for bent pipe of heat transfer pipe of steam generator

Technical Field

The invention relates to the technical field of inspection of heat transfer tubes of steam generators, in particular to an automatic ultrasonic detection device for a bent tube of a heat transfer tube of a steam generator.

Background

The steam generator heat transfer pipe is a key device for connecting a primary loop system and a secondary loop system to perform heat exchange, and is easy to generate primary side water stress corrosion cracking, intergranular corrosion, secondary side stress corrosion cracking, pitting corrosion, abrasion, dent, high cycle fatigue and abrasion under the conditions of high temperature, high pressure and high radiation for a long time.

With the increasing number of nuclear power plants in China, various problems can occur in the manufacturing stage and the operation process of the heat transfer tube of the steam generator, particularly the bent tube section of the heat transfer tube, which is a defect high-incidence area of the heat transfer tube and is also an area which is difficult to reach by a general inspection method due to the limitation of a bent structure.

For heat transfer tube detection, the traditional eddy current detection method cannot realize effective detection due to the influence of materials. The far-field eddy current and the near-field eddy current detection methods have dead zones, the ultrasonic detection method adopts a conventional ultrasonic probe to carry out detection from the inside of the heat transfer tube, and whether defects exist or not is confirmed through ultrasonic signals, so that the detection sensitivity can be effectively improved. In order to adapt to heat transfer pipes with various specifications, materials and shapes of a steam generator and a heat exchanger of a nuclear power plant so as to realize ultrasonic inspection of all pipe sections of the heat transfer pipes, a heat transfer pipe bend pipe section ultrasonic inspection technology needs to be developed so as to meet the ultrasonic inspection requirement of all pipe sections of the steam generator of the current mainstream reactor type nuclear power plant.

Disclosure of Invention

The invention aims to provide an automatic ultrasonic detection device for a heat transfer tube of a steam generator, which solves the problem of insufficient detection sensitivity of a conventional detection method on a tube bending region and fills up the blank of ultrasonic detection on the tube bending region of the heat transfer tube in China.

In order to achieve the above object, the present invention provides the following technical solutions:

the utility model provides a steam generator heat transfer pipe bend automatic ultrasonic testing device, its characterized in that, includes motor drive subassembly, preceding seal assembly, back seal assembly and ultrasonic probe subassembly, motor drive subassembly has the smooth brush of the ultrasonic cable transmission ultrasonic signal of the ultrasonic probe of front end motion to the rear end and provides the motor assembly of power, preceding seal assembly sets up motor drive subassembly's the place ahead just back seal assembly sets up motor drive subassembly's rear, ultrasonic probe subassembly sets up in bellows subassembly's the place ahead for detect heat transfer pipe bend district.

As an implementation mode, the sliding brush comprises a sliding brush shaft, sliding brush bearings and sliding brush gaskets, wherein a plurality of sliding brush bearings are sleeved on the sliding brush shaft at intervals, and the sliding brush gaskets are arranged between two adjacent sliding brush bearings.

As an embodiment, the sliding brush shaft is provided with a central main line hole and a wiring groove along the axial direction, the central main line hole is used for arranging the rotor cable, and the wiring groove is used for arranging and wiring the rotor cable.

As an implementation mode, a group of annular grooves are uniformly distributed on the outer ring of the sliding brush shaft, materials with ductility and conductivity are filled in the annular grooves, and the sliding brush shaft and the inner ring of the sliding brush bearing form interference fit.

As an implementation manner, a set of wire holes are arranged outside the sliding brush shaft and used for enabling a rotor cable to penetrate out from the inside, one end of the rotor cable is welded in the sliding brush shaft annular groove, and a material with ductility and conductivity is filled in the sliding brush shaft annular groove.

As an implementation manner, a set of rectangular grooves are formed on the outer part of the sliding brush bearing and used for welding the stator cable.

As an implementation manner, the sliding brush further comprises a sliding brush shaft buckling ring, and the sliding brush shaft buckling ring is arranged on the end face of the sliding brush bearing through the sliding brush shaft so as to prevent the sliding brush bearing from falling out.

As an implementation manner, the front sealing assembly comprises a front sealing head, a sealing ring, a sealing bearing, a corrugated pipe connecting shaft and a connecting shaft, wherein the corrugated pipe connecting shaft is connected with the connecting shaft, the front sealing head is fixed on the corrugated pipe connecting shaft, and the sealing bearing and the sealing ring are arranged inside the front sealing head.

As an implementation manner, the rear sealing assembly comprises an intermediate joint, a rear shell, a rear sealing head, a water pipe joint and a water retaining ring, wherein the rear shell is connected with the rear sealing head through the intermediate joint, the water pipe joint is installed on the intermediate joint, the interior of the intermediate joint is provided with holes, and the two water retaining rings are respectively installed on the intermediate joint and the rear shell.

As an implementation manner, the ultrasonic probe assembly comprises a probe clamp, a probe wafer, a clamp connecting piece, a corrugated pipe, a centering bearing, a centering slip ring, a front probe blocking head and a front water blocking ring, wherein the probe clamp is used for installing the probe wafer, the front end of the probe clamp is connected with the clamp connecting piece, the clamp connecting piece is connected with the corrugated pipe, the centering slip ring is enclosed outside the centering bearing, the centering bearing is installed on the corrugated pipe, the front probe blocking head is installed at the front end of the corrugated pipe, and the front water blocking ring is installed on the front probe blocking head.

Compared with the prior art, the automatic ultrasonic detection device for the heat transfer tube bend of the steam generator has the following beneficial effects:

the invention can meet the requirements of ultrasonic inspection before and during the service of the heat transfer pipe of the current reactor type steam generator and heat exchanger of the mainstream nuclear power plant.

The detection device is used for detecting the bent pipe section of the heat transfer pipe, and the flexible ultrasonic probe assembly is used for guaranteeing the accessibility of equipment so as to guarantee the full coverage of ultrasonic detection of the heat transfer pipe.

According to the special probe and the special assembly, the high-frequency narrow-pulse point focusing ultrasonic probe is arranged in the probe clamp, the heat transfer pipe is subjected to water immersion ultrasonic inspection, circumferential defects, axial defects, volume defects and wall thickness reduction changes can be found through analysis of ultrasonic automatic acquisition signals, the defects are accurately and qualitatively identified, and the defect height and the defect length are accurately quantified.

Further, the special circumferential mechanical driving device provided by the invention can carry and drive the special ultrasonic probe and the special ultrasonic assembly to move along the circumferential direction inside the heat transfer tube, and simultaneously perform spiral scanning and axial stepping circumferential scanning along the inside of the heat transfer tube under the action of the pusher; the circumferential motor is connected with the sliding brush through the coupler, an ultrasonic signal of rotary motion is transmitted to an ultrasonic cable which is fixed and stands relatively through the sliding brush, the driving device sends the probe to the bent pipe area, and rotary scanning of the flexible material part is realized through the motor and the sliding brush.

Furthermore, the water sealing device for the water immersion ultrasonic inspection provided by the invention provides couplant water required by the water immersion ultrasonic inspection, so that the probe can be completely immersed in the water, and the stable supply and recovery of the couplant and the water sealing of the whole inspection system are solved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings that are used in the technical description will be briefly described below.

FIG. 1 is a schematic diagram of a structure of an automatic ultrasonic detection device for a heat transfer tube bend of a steam generator;

FIG. 2 is a schematic diagram of a motor driving assembly according to the present invention;

FIG. 3 is a schematic view of a front seal assembly according to the present invention;

FIG. 4 is a schematic view of the rear seal assembly provided by the present invention;

fig. 5 is a schematic structural view of an ultrasonic probe assembly provided by the present invention.

Reference numerals illustrate:

1. a motor drive assembly; 2. a front seal head assembly; 3. a probe housing; 4. a rear seal head assembly; 5. a screw; 6. a bellows assembly; 7. an ultrasonic probe assembly; 8. a heat transfer tube bending tube; 9. a water pipe; 10. a motor coupling; 11. a reduction gearbox; 12. a motor; 13. a sliding brush shaft; 14. a sliding brush bearing; 15. a sliding brush gasket; 16. a sliding brush shaft snap ring; 17. a motor isolation cover; 18. a front sealing head; 19. a seal ring; 20. sealing the bearing; 21. a bellows connecting shaft; 22. a coupling shaft; 23. an intermediate joint; 24. a rear housing; 25. a rear sealing head; 26. a water pipe joint; 27. a water blocking ring; 28. a probe clamp; 29. a probe wafer; 30. a clamp connection; 31. a bellows; 32. centering the bearing; 33. centering slip ring; 34. a front baffle of the probe; 35. a front water baffle ring.

Detailed Description

Further details are provided below with reference to the specific embodiments.

As shown in fig. 1 to 5, the present invention provides an automatic ultrasonic testing device for a heat transfer tube bend of a steam generator, comprising a motor driving assembly 1, a water sealing assembly (comprising a front sealing assembly 2 and a rear sealing assembly 4), and an ultrasonic probe assembly 7. The ultrasonic detection device is mainly used for detecting the bent pipe of the heat transfer pipe. The ultrasonic probe of the bent pipe is sent to the pipe orifice of the specified heat transfer pipe through the crawler, the probe is sent to the specified position of the bent pipe section in the heat transfer pipe through the puller, coupling water is injected, the puller is used for pulling back, the ultrasonic probe of the bent pipe is driven by the rotary motor to move along the circumferential direction of the pipe, spiral scanning is formed, ultrasonic inspection is carried out in the pulling back process, inspection is completed, the coupling water is recovered, and the ultrasonic probe of the bent pipe is recovered.

The front end of the probe shell 3 is fixedly connected with the front sealing component 2 through glue, the rear end of the probe shell is fixedly connected with the rear sealing component 4 through a screw 5, and the probe shell is integrally used for packaging the motor driving component 1 and preventing water from entering the motor component. The front sealing assembly 2 is connected with the corrugated pipe assembly 6 through a coupling, the whole body enters the bent pipe tube 8 of the heat transfer pipe for detection, and the water pipe 9 is connected with a water pipe joint in the rear sealing assembly 4 and used for coupling water supply.

As shown in fig. 2, the motor drive assembly 1 includes a motor coupling 10, a motor assembly, a wiper and a motor cage 17. The motor assembly includes a reduction gearbox 11 and a motor 12, and the wiper includes a wiper shaft 13, a wiper bearing 14, a wiper pad 15, and a wiper shaft snap ring 16.

The motor 12 and the reduction gearbox 11 are connected by threads such that the motor assembly forms an integrated firmware. The reduction gearbox 11 is arranged close to the sliding brush, and the motor 12 is arranged at a position far away from the sliding brush. One end of the motor coupler 10 is connected with the shaft of the reduction gearbox 11, and the other end is connected with one end of the sliding brush shaft 13, so that the motor assembly and the sliding brush are connected together.

The wiper includes a wiper shaft 13, a wiper bearing 14, a wiper pad 15, and a wiper shaft snap ring 16. The 4 sliding brush bearings 14 are sleeved outside the sliding brush shaft 13 at intervals, sliding brush gaskets 15 are arranged between every two adjacent 2 sliding brush bearings 14, the sliding brush gaskets 15 are used for separating the sliding brush bearings 14, the sliding brush bearings are prevented from being communicated with each other, signal interference is generated, and a sliding brush shaft retaining ring 16 is arranged on the end face of the sliding brush bearing 14 closest to the motor isolation cover, so that the sliding brush bearings are prevented from falling off in rotation.

The sliding brush shaft 13 is provided with a central main line hole and a wiring groove along the axial direction, the wiring groove is arranged on the outer ring of the sliding brush shaft 13 and used for filling materials with better ductility and conductivity, and the central main line hole of the sliding brush shaft 13 is used for arranging a rotor cable. A series of annular grooves are uniformly distributed on the outer ring of the sliding brush shaft 13, and the annular grooves are arranged at intervals. The ring groove is filled with materials with better ductility and conductivity like gold wires, and the like, and forms interference fit with the inner ring of the sliding brush bearing 14, so that the relative fixation of the sliding brush shaft 13 and the inner ring of the sliding brush bearing 14 is ensured, and the conductivity of the bearing is also ensured. A series of wire holes are arranged outside the sliding brush shaft 13, a wire control is designed in each wire slot and used for enabling cables inside the central main wire hole to pass out, and rotor cables pass out from the inside and are welded on the ring groove wires.

A wiper pad 15 is disposed between the wiper bearings 14 for separately disposing the wiper bearings 14, and a wiper shaft retaining ring 16 is disposed on an end face of the wiper bearings 14 through the wiper shaft 13 to prevent the wiper bearings 14 from coming off.

A series of rectangular grooves are formed in the outer portion of the sliding brush bearing 14 and are used for welding stator cables, coaxial cables can be adopted for the stator cables and the rotor cables, reliability of signal transmission is guaranteed, interference caused by noise generated by the cables is reduced, and meanwhile, metal materials with good ductility such as gold wires are adopted, and stability of signal transmission can be guaranteed.

The brush shaft 13 may be made of a high-strength nonmetallic material (such as PEEK or similar strength nonmetallic materials are commonly used), so that the bearable torque of the brush is improved and the service life of the brush is ensured. The motor assembly is connected with the sliding brush through a motor coupler 10, and the sliding brush is used for transmitting ultrasonic signals to an ultrasonic cable fixed at the rear end through an ultrasonic probe moving at the front end.

As shown in fig. 1, the water seal assembly includes a front seal assembly 2 and a rear seal assembly 4. The front seal assembly 2 is disposed at the front of the motor drive assembly 1, and the rear seal assembly 4 is disposed at the rear of the motor drive assembly 1.

As shown in fig. 3, the front seal assembly 2 includes a front seal head 18, a seal ring 19, a seal bearing 20, a bellows coupling shaft 21, and a coupling shaft 22. The bellows connecting shaft 21 is connected with the connecting shaft 22 through screws, the front sealing head 18 is fixed on the bellows connecting shaft 21, the sealing bearing 20 and the two sealing rings 19 are arranged inside the front sealing head 18, the sealing bearing 20 is used for rotating the bellows, and the sealing rings 19 play a sealing role to prevent water from penetrating into the motor.

As shown in fig. 4, the rear seal assembly 4 includes an intermediate joint 23, a rear housing 24, a rear seal head 25, a water pipe joint 26, and a water deflector ring 27. The rear housing 24 and the rear sealing head 25 are directly connected by glue through the intermediate joint 23, and the water pipe joint 26 is screw-mounted on a screw hole inside the intermediate joint 23 for coupling the supply of water. Two crescent holes are symmetrically formed in the middle joint 23 and are used for passing cables. Two water retaining rings 27 are mounted in grooves on the intermediate head 23 and rear housing 24, respectively, for coupling with the water seal.

The water sealing assembly provided by the invention provides couplant water required by ultrasonic inspection, can enable the probe to be completely immersed in the water, and solves the problems of stable supply and recovery of the couplant and water sealing of the whole inspection system.

As shown in fig. 5, the ultrasonic probe assembly 7 includes a probe holder 28, a probe wafer 29, a holder connector 30, a bellows 31, a centering bearing 32, a centering slip ring 33, a probe front stop 34, and a front water stop ring 35. The ultrasonic probe assembly 7 is a flexible ultrasonic probe assembly to ensure accessibility of the apparatus to ensure full coverage of the heat transfer tube for ultrasonic inspection. The high-frequency narrow-pulse point focusing ultrasonic probe is arranged in the probe clamp, and can be carried with independent straight probes, circumferential probes and axial probes, and the probes are distributed in different areas so as to ensure that the ultrasonic probe has enough flexibility.

The probe holder 28 is used for mounting a probe wafer 29, the front end of the probe holder 28 is connected with a holder connector 30, and the holder connector 30 is connected with a bellows 31. The centering bearing 32 and the centering slip ring 33 together form a centering device, the centering slip ring 33 surrounds the centering bearing 32, the centering bearing 32 is mounted on the corrugated tube 31, and the centering device realizes centering and rotation of the corrugated tube 31 in the bent tube. The front baffle 34 of the probe is arranged at the front end of the corrugated pipe 31 for guiding the probe, and the front baffle ring 35 is arranged on the front baffle 34 of the probe for sealing water at the front end of the probe assembly.

The bellows 31 is preferably of a soft flexible material that facilitates passage through the bend section.

The invention provides a motor driving assembly (figure 2), a circumferential motor is connected with a sliding brush through a coupler, an ultrasonic signal of rotary motion is transmitted to an ultrasonic cable which is relatively fixed and static through the sliding brush, a driving device sends a probe to a bent pipe area, and rotary scanning of a flexible material part is realized through the motor and the sliding brush.

The ultrasonic probe moves along the axial direction of the heat transfer tube and is completed by a push-pull device, and when the ultrasonic probe reaches a designated position, the water supply system is controlled to inject water as a coupling agent; meanwhile, the circumferential motor drives the probe to move along the circumferential direction of the pipeline, so that spiral scanning is formed, the ultrasonic instrument converts the received ultrasonic probe pulse signals into digital signals, the digital signals are transmitted back to the acquisition workstation, the coded signals of the push-pull device and the rotary motor are received, and the coded signals are displayed through ultrasonic acquisition software. And providing the data analyst with signal analysis to judge whether the heat transfer tube has defects or not and qualitatively and quantitatively determining the defects. If the circumferential distribution defect exists, the circumferential position of the maximum signal generation needs to be found, and the circumferential position is axially scanned, so that the circumferential distribution defect is quantified. The ultrasonic probe assembly 7 uses a high-frequency narrow pulse point focusing probe, and is installed in a probe clamp. The longitudinal wave straight probe is used for monitoring the wall thickness and determining the defect; the longitudinal wave straight probe is obliquely incident into the workpiece at a certain angle along the axial direction and is refracted into oblique incident transverse waves, so that the circumferential defects and corrosion defects of the workpiece are inspected; in addition, the longitudinal wave straight probe is incident at a certain angle away from the axial direction, and is refracted into oblique incident transverse waves in the workpiece, so that the axial defects and corrosion defects of the workpiece are inspected.

The automatic detection of the invention is mainly characterized in that the device realizes controlled movement and track scanning (including spiral scanning, rectangular scanning and the like) of the ultrasonic probe inside the heat transfer tube by means of a series of devices such as a controller, a driver, a driving motor and the like, and is different from the conventional manual ultrasonic detection which needs to rely on manual driving of the probe for movement and detection.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a steam generator heat transfer pipe bend automatic ultrasonic testing device, its characterized in that, includes motor drive subassembly (1), preceding seal assembly (2), back seal assembly (4) and ultrasonic probe subassembly (7), motor drive subassembly (1) have with the ultrasonic probe of front end motion to the fixed smooth brush of ultrasonic cable transmission ultrasonic signal of rear end and the motor assembly that provides power, preceding seal assembly (2) set up in the place ahead of motor drive subassembly (1) just back seal assembly (4) set up the rear of motor drive subassembly (1), ultrasonic probe subassembly (7) set up in the place ahead of bellows subassembly (6) for detect the heat transfer pipe bend district.

2. The automatic ultrasonic detection device for the bent pipe of the heat transfer pipe of the steam generator according to claim 1, wherein the sliding brush comprises a sliding brush shaft (13), sliding brush bearings (14) and sliding brush gaskets (15), a plurality of sliding brush bearings (14) are sleeved on the sliding brush shaft (13) at intervals, and the sliding brush gaskets (15) are arranged between two adjacent sliding brush bearings (14).

3. The automatic ultrasonic detection device for the bent pipe of the heat transfer pipe of the steam generator according to claim 2, wherein the sliding brush shaft (13) is provided with a central main line hole and a wiring groove along the axial direction, the central main line hole is used for arranging a rotor cable, and the wiring groove is used for arranging and wiring the rotor cable.

4. A device for automatically and ultrasonically inspecting a bent tube of a heat transfer tube of a steam generator according to claim 2 or 3, wherein a group of annular grooves are uniformly distributed on the outer ring of the sliding brush shaft (13), the annular grooves are filled with a material with ductility and conductivity, and the sliding brush shaft (13) and the inner ring of the sliding brush bearing (14) form interference fit.

5. The automatic ultrasonic detection device for the bent pipe of the heat transfer pipe of the steam generator according to claim 4, wherein a group of wire holes are formed outside the sliding brush shaft (13) and used for enabling a rotor cable to pass out from the inside, and one end of the rotor cable is welded in the annular groove of the sliding brush shaft (13) and filled with a material with ductility and conductivity.

6. The automatic ultrasonic inspection device for heat transfer tube bends of steam generators according to claim 2, characterized in that said sliding brush bearing (14) is externally provided with a set of rectangular grooves for welding stator cables.

7. The automatic ultrasonic inspection device for heat transfer tube bend of steam generator according to claim 2, wherein the sliding brush further comprises a sliding brush shaft snap ring (16), the sliding brush shaft snap ring (16) being arranged on an end face of the sliding brush bearing (14) through the sliding brush shaft (13) to prevent the sliding brush bearing (14) from coming out.

8. The automatic ultrasonic detection device for a heat transfer tube bend of a steam generator according to claim 1, wherein the front sealing assembly (2) comprises a front sealing head (18), a sealing ring (19), a sealing bearing (20), a corrugated tube coupling shaft (21) and a coupling shaft (22), the corrugated tube coupling shaft (21) is connected with the coupling shaft (22), the front sealing head (18) is fixed on the corrugated tube coupling shaft (21), and the sealing bearing (20) and the sealing ring (19) are arranged inside the front sealing head (18).

9. The automatic ultrasonic detection device for the bent pipe of the heat transfer pipe of the steam generator according to claim 1, wherein the rear sealing assembly (4) comprises an intermediate joint (23), a rear shell (24), a rear sealing head (25), a water pipe joint (26) and a water retaining ring (27), the rear shell (24) and the rear sealing head (25) are connected through the intermediate joint (23), the water pipe joint (26) is installed on the intermediate joint (23), an opening is formed in the intermediate joint (23), and two water retaining rings (27) are installed on the intermediate joint (23) and the rear shell (24) respectively.

10. The automatic ultrasonic detection device for a heat transfer tube bend of a steam generator according to claim 1, wherein the ultrasonic probe assembly (7) comprises a probe clamp (28), a probe wafer (29), a clamp connector (30), a corrugated tube (31), a centering bearing (32), a centering slip ring (33), a front probe baffle (34) and a front water baffle ring (35), the probe clamp (28) is used for installing the probe wafer (29), the front end of the probe clamp (28) is connected with the clamp connector (30), the clamp connector (30) is connected with the corrugated tube (31), the centering slip ring (33) is enclosed outside the centering bearing (32), the centering bearing (32) is installed on the corrugated tube (31), the front probe baffle (34) is installed on the front end of the corrugated tube (31), and the front water baffle ring (35) is installed on the front probe baffle (34).