JP2012159471A - Inspection method and inspection device of heat-transfer pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detectability of an inspection signal which inspects heat-transfer pipes.SOLUTION: An inspection method of heat-transfer pipes includes: a step S11 of inspecting heat-transfer pipes by an eddy current flaw detector having an array type probe to be inserted into the heat-transfer pipes, before assembling the heat-transfer pipes in a steam generator; steps S13 and S14 of excluding heat-transfer pipes from which noise signals exceeding a prescribed amplitude have been detected by the inspection, from the object to be assembled, while taking heat-transfer pipes from which noise signals not exceeding the prescribed amplitude have been detected by the inspection, as the object to be assembled; and a step S15 of making a database of pre-assembling inspection results about heat-transfer pipes taken as the object to be assembled.

Description

  The present invention relates to a heat transfer tube inspection method and an inspection apparatus applied when inspecting a heat transfer tube of a heat exchanger.

  For example, in a steam generator as a heat exchanger used in a pressurized water reactor (PWR), a large number of heat transfer tubes formed in an inverted U shape are arranged in the body. The heat transfer tube is inspected for its soundness before it is assembled to the steam generator when the steam generator is manufactured, when it is assembled to the steam generator (before service), and after the steam generator is used. Such an inspection employs eddy current testing (ECT) and is performed by inserting an ECT probe into the heat transfer tube.

  The ECT probe is a probe core (bobbin) inserted into a heat transfer tube and wound with a set of coils used for generation and detection of eddy current along the circumferential direction of the heat transfer tube (hereinafter referred to as a bobbin). (Refer to Patent Document 1, for example).

  In addition, there is an ECT probe in which a plurality of coils are arranged along the circumferential direction of a heat transfer tube (hereinafter referred to as an array type probe) (see, for example, Patent Document 2).

JP 2004-257912 A JP 2008-197016 A

  Inspecting the heat transfer tube as described above, generally, before assembling to the steam generator when manufacturing the steam generator, due to deep thinning or dents made by external surface modification processing at the time of manufacturing the heat transfer tube Bobbin type probes are used for the purpose of excluding tubes with extreme deformation prior to assembly into the steam generator. On the other hand, when assembled in a steam generator (before service) or after the steam generator is serviced, an array type probe is used for the purpose of improving the detectability of circumferential damage and crack damage.

  Here, as a generation source of the ECT signal, there is a noise signal that does not affect the soundness of the heat transfer tube, such as a change in permeability and a change in electrical resistance caused by manufacturing, in addition to thinning and dents. However, since the coil characteristics of the bobbin type probe and the array type probe are different, a small amplitude signal from the bobbin type probe detected before assembly may appear as a large amplitude signal at the array type probe after assembly. is there. For this reason, in a portion where there is a large noise signal, for example, the S / N ratio may decrease as a result of a decrease in the S / N ratio with respect to a small signal such as a crack that has occurred after service, and the detectability may decrease.

  This invention solves the subject mentioned above, and aims at providing the inspection method and inspection apparatus of a heat exchanger tube which can improve the detectability of the inspection signal which inspects a heat exchanger tube.

  In order to achieve the above-mentioned object, the heat transfer tube inspection method of the present invention includes an eddy current flaw detection apparatus having an array type probe inserted into the heat transfer tube before assembling the heat transfer tube to the heat exchanger. A step of inspecting the heat transfer tube; and then, excluding the heat transfer tube in which a noise signal exceeding a predetermined amplitude is detected by the inspection from an assembly target, and the heat transfer tube in which a noise signal within a predetermined amplitude is detected And a step of creating a database of the pre-assembly inspection results relating to the heat transfer tubes as the assembly target.

  According to this heat transfer tube inspection method, in addition to deep thinning and extremely deformed tubes, large amplitude noise signals that lower the S / N ratio for small signals from cracks and the like are detected in subsequent inspections. By using the excluded heat transfer tube as an exclusion tube, it is possible to improve the detectability of an inspection signal for inspecting the heat transfer tube and improve the soundness of the heat exchanger. In addition, the heat transfer tube in which a noise signal within a predetermined amplitude is detected is to be assembled, and the pre-assembly inspection results relating to the heat transfer tube to be assembled are made into a database so that the pre-assembly inspection results can be It can be used as a reference for inspection after assembly by a current flaw detection apparatus.

  Further, the heat transfer tube inspection method of the present invention is the assembly position of the heat transfer tube to the heat exchanger after the heat transfer tube is assembled to the heat exchanger and before the heat exchanger is used, And a step of creating a database of the assembly direction of the heat transfer tubes to the heat exchanger.

  According to this heat transfer tube inspection method, after the heat transfer tube is assembled to the heat exchanger, information on the assembly position of the heat transfer tube to the heat exchanger and the assembly direction of the heat transfer tube to the heat exchanger can be obtained. In addition, the pre-assembly inspection result can be more effectively used as a reference for subsequent inspection by the same eddy current flaw inspection apparatus for the manufactured heat exchanger.

  Further, the heat transfer tube inspection method of the present invention is a method in which the heat transfer tube is inspected by the eddy current flaw inspection apparatus after the heat transfer tube is assembled to the heat exchanger and before the heat exchanger is used. And obtaining the inspection result after assembly, and then creating a database of the inspection result after assembly.

  According to this heat transfer tube inspection method, the heat transfer tube is inspected by the eddy current flaw inspection apparatus after the heat transfer tube is assembled to the heat exchanger and before the heat exchanger is used, so that heat exchange can be performed. Comparison with the heat transfer tube before assembling to the heat exchanger and the heat transfer tube after having used the heat exchanger can be performed.

  In the heat transfer tube inspection method of the present invention, after the heat exchanger in which the heat transfer tube is assembled is used, the heat transfer tube is inspected by the eddy current flaw inspection device to obtain a post-operation inspection result. And a step of reading at least the pre-assembly inspection result and comparing it with the post-service inspection result, and then forming a database of the post-service inspection result together with the comparison result. And

  Waveforms created in the database include shallow thinning, mild deformation, and mild noise signals. When a slight damage signal is generated in such a part, the S / N generally decreases. Although the detectability decreases, this heat transfer tube inspection method recognizes subtle changes by comparing pre-assembly inspection results and post-service inspection results, which were inspected by the same eddy current flaw detection equipment. It becomes easy to improve the detectability.

  Further, the heat transfer tube inspection method of the present invention can be detected by the eddy current flaw detection device in the step of inspecting the heat transfer tube by the eddy current flaw detection device before assembling the heat transfer tube to the heat exchanger. It includes a step of placing the heat transfer tube on the upper surface of the inspection plate on which the marking portion is arranged.

  According to this heat transfer tube inspection method, the marking is completed simply by placing the heat transfer tube on the inspection plate, so that it is not necessary to attach a separate marking. Moreover, the heat transfer tube shaft position of the inspection result can be calculated more accurately by the marking portion. Furthermore, since the marking part is a single contact with the outer peripheral surface of the heat transfer tube and generates a marking signal only in a specific direction of the array type probe, the position in the circumferential direction of the heat transfer tube can also be stored as an item in the database. Furthermore, by storing the direction of assembly of the heat transfer tube to the heat exchanger in the storage means together with the marking part, in the comparison of the inspection results, it is possible to use a small signal pattern for each inspection result before and after assembly. Event that occurs after the service can be used to identify the physical position of the heat exchanger by identifying the direction position, and further identifying the physical position in the circumferential direction using the marking signal from one piece It is a clue to understand more in detail.

  In order to achieve the above object, a heat transfer tube inspection device according to the present invention includes an eddy current flaw detection device having an array-type probe inserted into a heat transfer tube, before assembling the heat transfer tube into a heat exchanger, and A storage unit that stores the inspection results obtained by inspecting the heat transfer tubes by the eddy current flaw inspection apparatus after the heat transfer tubes are assembled, and a comparison unit that compares the inspection results. And

  According to this heat transfer tube inspection device, before assembling the heat transfer tube to the heat exchanger, in addition to deep thinning and extreme deformation tubes, the S / N ratio can be set for small signals such as cracks in subsequent inspections. It is possible to detect a noise signal having a large amplitude that decreases. If the heat transfer tube from which this large amplitude noise signal is detected is an excluded tube, the detectability of the inspection signal for inspecting the heat transfer tube can be improved, and the soundness of the heat exchanger can be improved. In addition, the heat transfer tube in which a noise signal within a predetermined amplitude is detected is to be assembled, and the pre-assembly inspection results relating to the heat transfer tube to be assembled are made into a database so that the pre-assembly inspection results can be It can be used as a reference for inspection after assembly by a current flaw detection apparatus.

  Further, in the heat transfer tube inspection device of the present invention, a marking portion that can be detected by the eddy current flaw inspection device is disposed on the upper surface, and the heat transfer tube is mounted on the upper surface in an inspection before being assembled to the heat exchanger. It is characterized by comprising an inspection plate to be placed.

  According to this heat transfer tube inspection apparatus, the marking is completed simply by placing the heat transfer tube on the inspection plate, so that it is not necessary to attach a separate marking. Moreover, the heat transfer tube shaft position of the inspection result can be calculated more accurately by the marking portion. Furthermore, since the marking part is a single contact with the outer peripheral surface of the heat transfer tube and generates a marking signal only in a specific direction of the array type probe, the position in the circumferential direction of the heat transfer tube can also be stored as an item in the database. Furthermore, by storing the direction of assembly of the heat transfer tube to the heat exchanger in the storage means together with the marking part, in the comparison of the inspection results, it is possible to use a small signal pattern for each inspection result before and after assembly. Event that occurs after the service can be used to identify the physical position of the heat exchanger by identifying the direction position, and further identifying the physical position in the circumferential direction using the marking signal from one piece It is a clue to understand more in detail.

  In the heat transfer tube inspection apparatus according to the present invention, the inspection plate is arranged in the same positional relationship as the tube support plate in which the marking portion supports the heat transfer tube in the heat exchanger. .

  According to this heat transfer tube inspection apparatus, since the marking is performed at the same position as the tube support plate, the heat transfer tube shaft position matches between the inspection before being assembled to the heat exchanger and the inspection after being assembled to the heat exchanger. As a result, the effect of accurately calculating the heat transfer tube shaft position can be significantly obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the detectability of the test | inspection signal which test | inspects a heat exchanger tube can be improved.

FIG. 1 is a schematic sectional side view of a steam generator. FIG. 2 is a schematic view showing the time when the steam generator is manufactured. FIG. 3 is a schematic diagram showing a heat transfer tube inspection apparatus according to an embodiment of the present invention. FIG. 4 is a perspective view showing an inspection plate. FIG. 5 is a cross-sectional view showing the inspection plate. FIG. 6 is a flowchart showing a heat transfer tube inspection method according to the embodiment of the present invention. FIG. 7 is a diagram illustrating an example of creating a database.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic sectional side view of a steam generator. The steam generator 1 as a heat exchanger is used, for example, in a pressurized water reactor (PWR). The pressurized water reactor uses light water as a reactor coolant and neutron moderator. The pressurized water reactor sends primary cooling water to the steam generator 1 as high-temperature and high-pressure water that does not boil light water over the entire core. In the steam generator 1, the heat of the primary cooling water at high temperature and high pressure is transmitted to the secondary cooling water, and water vapor is generated in the secondary cooling water. Then, the steam generator is rotated by this steam to generate electricity.

  The steam generator 1 has a hollow cylindrical shape that extends in the up-down direction and is hermetically sealed, and has a trunk portion 2 in which the lower half is slightly smaller in diameter than the upper half. The trunk portion 2 is provided with a tube group outer cylinder 3 having a cylindrical shape disposed at a predetermined distance from the inner wall surface of the trunk portion 2 in the lower half portion thereof. The lower end portion of the tube group outer tube 3 extends to the vicinity of the tube plate 4 disposed below in the lower half of the body portion 2. A heat transfer tube group 5A is provided in the tube group outer tube 3. The heat transfer tube group 5A includes a plurality of heat transfer tubes 5 having an inverted U shape. Each heat transfer tube 5 is arranged with the U-shaped arc portion facing upward, the lower end portion is inserted and supported through the tube hole of the tube plate 4, and the intermediate portion is a tube through a plurality of tube support plates 6. It is supported by the group outer cylinder 3. The tube support plate 6 is formed with a large number of heat transfer tube insertion holes, and supports each heat transfer tube 5 by inserting each heat transfer tube 5 into the heat transfer tube insertion hole.

  The body 2 is provided with a water chamber 7 at its lower end. The interior of the water chamber 7 is divided into an entrance chamber 7A and an exit chamber 7B by a partition wall 8. One end of each heat transfer tube 5 communicates with the entrance chamber 7A, and the other end of each heat transfer tube 5 communicates with the exit chamber 7B. Further, the entrance chamber 7A is formed with an inlet nozzle 7Aa that communicates with the outside of the body portion 2, and the exit chamber 7B is formed with an exit nozzle 7Ba that communicates with the outside of the body portion 2. The inlet nozzle 7Aa is connected to a cooling water pipe (not shown) through which primary cooling water is sent from the pressurized water reactor, and the outlet nozzle 7Ba sends the primary cooling water after heat exchange to the pressurized water reactor. The cooling water piping (not shown) to send is connected.

  In the upper half of the body portion 2, an air-water separator 9 that separates feed water into steam and hot water, and a moisture separator that removes the moisture of the separated steam and makes it close to dry steam. 10 is provided. Between the steam / water separator 9 and the heat transfer tube group 5A, a water supply pipe 11 for supplying secondary cooling water from the outside into the body 2 is inserted. Furthermore, the trunk | drum 2 has the vapor | steam exhaust port 12 formed in the upper end part. Further, the body 2 has a tube plate in the lower half of which the secondary cooling water supplied from the water supply pipe 11 into the body 2 flows down between the body 2 and the tube group outer tube 3. 4, a water supply passage 13 is formed that is folded back and raised along the heat transfer tube group 5A. The steam outlet 12 is connected to a cooling water pipe (not shown) for sending steam to the turbine, and the water supply pipe 11 has two steams used in the turbine cooled by a condenser (not shown). A cooling water pipe (not shown) for supplying the next cooling water is connected.

  In such a steam generator 1, the primary cooling water heated in the pressurized water reactor is sent to the entrance chamber 7 </ b> A, circulates through the numerous heat transfer tubes 5, and reaches the exit chamber 7 </ b> B. On the other hand, the secondary cooling water cooled by the condenser is sent to the water supply pipe 11 and rises along the heat transfer pipe group 5 </ b> A through the water supply path 13 in the trunk portion 2. At this time, heat exchange is performed between the high-pressure and high-temperature primary cooling water and the secondary cooling water in the trunk portion 2. Then, the cooled primary cooling water is returned from the exit chamber 7B to the pressurized water reactor. On the other hand, the secondary cooling water subjected to heat exchange with the high-pressure and high-temperature primary cooling water rises in the body portion 2 and is separated into steam and hot water by the steam separator 9. The separated steam is sent to the turbine after moisture is removed by the moisture separator 10.

  FIG. 2 is a schematic view showing the time when the steam generator is manufactured. In manufacturing the steam generator 1 described above, the heat transfer tube 5 includes an upper half portion of the body portion 2, an air / water separator 9, a moisture separator 10, and a water supply tube 11 provided in the upper half portion. Assembled to the lower half of the body 2 before As shown in FIG. 2, the tube group outer cylinder 3, the tube plate 4, and each tube support plate 6 are assembled in a state where the lower half of the body portion 2 is placed horizontally on the gantry 20. Thereafter, the heat transfer tube 5 is penetrated through the tube support plates 6 at both ends from the upper side in the lower half of the trunk portion 2 (right side for horizontal placement in FIG. 2), and is penetrated and fixed to the tube plate 4. It is arranged in a hemispherical shape on the upper side in the lower half of the part 2.

  The heat transfer tubes 5 are formed as a single heat transfer tube layer that is horizontally arranged so that the radius increases from the small arc to the outside, and is penetrated by the tube support plate 6 and the tube plate 4 for each heat transfer tube layer. The The heat transfer tube layer is in a stacked state in which the tube support plate 6 and the tube plate 4 are stacked in order, and on the upper side (the right side in FIG. 2) in the lower half of the body 2 so that it can be taken out from the top. , Placed on the lifter 21. A lifter 22 is provided between the lifter 21 and the lower half of the body 2 for a worker who performs an operation of penetrating the heat transfer tube 5 through the tube support plate 6 and the tube plate 4.

  The heat transfer tube 5 of the steam generator 1 manufactured in this way is assembled to the steam generator 1, after being assembled to the steam generator 1 and before the use of the steam generator 1, and the steam generator. Each is tested after 1 is in service.

  FIG. 3 is a schematic diagram showing a heat transfer tube inspection apparatus according to the present embodiment. As shown in FIG. 3, an eddy current flaw detection apparatus 30 that performs eddy current testing (ECT) is used as an inspection apparatus that inspects the heat transfer tube 5. The eddy current flaw detection apparatus 30 includes an array-type probe 31, a probe feeder 32, a flaw detector 33, a control means 34, a storage means 35, an input means 36, and a comparison means 37. .

  The array probe 31 is inserted into the heat transfer tube 5, and a plurality of coils are arranged along the circumferential direction of the heat transfer tube 5. In the array type probe 31, for example, a total of 24 sets of coils in which 12 sets are arranged in two stages in the direction of insertion (movement) into the heat transfer tube 5 are arranged around the probe. And the thickness reduction and dent of the heat exchanger tube 5 are detected by the difference between the signals of the two coils in each group. That is, the array-type probe 31 can perform more accurate flaw detection by locally capturing changes in eddy current at 24 locations in the circumferential direction of the heat transfer tube 5.

  The probe feeder 32 moves the array probe 31 into the heat transfer tube 5 at a predetermined speed by rotating a roller 32a that winds the cable 31a connected to the array probe 31 at a predetermined speed.

  The flaw detector 33 excites one of a pair of coils in the array type probe 31 through the cable 31a and detects a detection signal induced in the other coil.

  The control means 34 is composed of a microcomputer or the like, and processes the moving speed of the array type probe 31 in the probe feeder 32, the detection timing at the flaw detector 33, and the detection signal detected at the flaw detector 33. The control unit 34 is connected to a storage unit 35, an input unit 36, and a comparison unit 37.

  The storage means 35 stores the detection signal detected by the flaw detector 33, that is, the inspection result obtained by inspecting the heat transfer tube 5 by the array probe 31 in a database (see FIG. 7). The control means 34 performs processing for creating a database of the detection signals detected by the flaw detector 33 as inspection results.

  The input means 36 is for inputting input information, and includes, for example, a keyboard, a mouse, and an identification information (barcode etc.) reading device. As the input information input to the input means 36, the steam generator 1 is used before or after being assembled to the steam generator 1 as a management number of the heat transfer tube 5 or as an inspection type. Before or after the steam generator 1 is put into service, the date and time of inspection, and the position where the heat transfer tube 5 is assembled to the steam generator 1 as a steam generator assembly address (through the tube plate 4). And the direction in which the heat transfer tube 5 is assembled to the entrance chamber 7A or the exit chamber 7B of the steam generator 1 as the steam generator assembly direction. The control unit 34 associates the input information with the inspection result obtained by inspecting the heat transfer tube 5.

  The comparison means 37 is an inspection in which the heat transfer tube 5 after the steam generator 1 is put into service is inspected (test result after use), and at least the heat transfer tube 5 before being installed in the steam generator 1 is inspected. Compare with results (pre-assembly inspection results). The control means 34 performs processing for creating a database of the comparison results.

  FIG. 4 is a perspective view showing the inspection plate, and FIG. 5 is a cross-sectional view showing the inspection plate. As shown in FIGS. 4 and 5, the eddy current flaw inspection apparatus 30 has an inspection plate 38 used for inspection of the heat transfer tube 5 before being assembled to the steam generator 1.

  The inspection plate 38 is a plate that is sized to place the entire heat transfer tube 5, and is formed of a material that does not affect the signal detected by the coil of the array probe 31, for example, a resin material. . A plurality of marking portions 38a are provided at predetermined intervals on the surface of the inspection plate 38 on which the heat transfer tube 5 is placed. The marking portion 38a is formed of a material that can be reduced by an arithmetic process using a plurality of frequencies, for example, the same stainless alloy as the tube support plate 6. As shown in FIG. 5, the marking portion 38 a is in contact with the outer peripheral surface of the heat transfer tube 5 with a line in a state where the heat transfer tube 5 is placed on the surface of the inspection plate 38. Moreover, it is preferable that the marking part 38a is arrange | positioned in the same positional relationship as the pipe support plate 6. FIG.

  FIG. 6 is a flowchart showing a heat transfer tube inspection method according to the present embodiment, and FIG. 7 is a diagram showing an example of creating a database.

  The heat transfer tube 5 is inspected by inspecting the heat transfer tube 5 before being assembled to the steam generator 1 [inspection before assembly]. In this pre-assembly inspection, the heat transfer tube 5 is inspected by the eddy current flaw inspection apparatus 30 described above (step S11). In step S <b> 11, the heat transfer tube 5 is placed on the above-described inspection plate 38 with the end of the heat transfer tube 5 being aligned with the edge of the inspection plate 38. In this way, the distance from the edge of the inspection plate 38 to the marking portion 38a matches the distance from the end of the heat transfer tube 5 to the marking portion 38a. It is possible to recognize the axial position of the heat transfer tube 5 from the marking signal detected at the position. In the inspection in step S11, the heat sink tube 5 is thinned and the dent at the time of manufacture of the heat transfer tube 5 is inspected, but those outside the standards that affect the soundness are excluded as excluded tubes. At the same time, in the inspection in step S11, a noise signal that does not affect the soundness of the heat transfer tube 5 is detected, such as a change in magnetic permeability or a change in electrical resistance caused by the manufacture of the heat transfer tube 5. When the noise signal exceeds a predetermined amplitude (step S12: No), the heat transfer tube 5 is set as an excluded tube that is not an assembly target (step S13). Here, the noise signal exceeding a predetermined amplitude means a noise signal having a large amplitude that lowers the S / N ratio with respect to a small signal from a crack or the like in a later inspection. On the other hand, if the noise signal is within the predetermined amplitude (step S12: Yes), the heat transfer tube 5 is set to be assembled (step S14). Next, the pre-assembly inspection result relating to the heat transfer tube 5 to be assembled is stored in the storage means 35 in association with the management number of the heat transfer tube 5 of the result (step S15). In the pre-assembly inspection, the heat transfer tube 5 is placed on the above-described inspection plate 38 in the step of inspecting the heat transfer tube 5 (step S11).

  In addition, the heat transfer tube 5 is inspected after the heat exchanger tube 5 is assembled after being assembled to the steam generator 1 and before the steam generator 1 is put in service [inspection after assembly (before service)]. In this post-assembly (before service) inspection, the steam generator assembly address and the steam generator assembly direction are determined by assembling the heat transfer tube 5 to the steam generator 1, so these steam generator assembly addresses The steam generator assembly direction can be input as input information (step S21). Thus, the steam generator assembly address and the steam generator assembly direction can be stored in the storage means 35 in association with the pre-assembly inspection result. Next, the heat transfer tube 5 is inspected by the above-described eddy current flaw inspection apparatus 30 to obtain a post-assembly inspection result (step S22). Next, the post-assembly inspection results are stored in the storage means 35 in association with the above-mentioned pre-assembly inspection results together with the steam generator assembly address and the steam generator assembly direction (step S23). Note that the steps S22 and S23 may not be performed after the steam generator 1 is assembled and before the steam generator 1 is put into service.

  Moreover, the inspection method of the heat exchanger tube 5 performs the inspection of the heat exchanger tube 5 after the steam generator 1 is put into service [post-service inspection]. This inspection is performed at this time, for example, because it is necessary to periodically stop the operation of the core for fuel replacement work. In this in-service inspection, the heat transfer tube 5 is inspected by the above-described eddy current flaw inspection apparatus 30 to obtain an in-service inspection result (step S31). Next, the pre-assembly inspection result is read from the storage means 35 and compared with the post-service inspection result (step S32). Next, the in-service inspection result is stored in the storage means 35 in association with the above-mentioned pre-assembly inspection result together with the comparison result and is made into a database (step S33).

  If there is a post-service inspection result acquired before, the previous post-service inspection result may be read from the storage means 35 together with the pre-assembly inspection result, and the acquired post-service inspection result may be compared. The degree of change of the heat tube 5 can be recognized.

  And the database of the memory | storage means 35 is managed by the management number of the heat exchanger tube 5, as shown in FIG. 7, inspection classification (history of the said inspection), a steam generator assembly address, and a steam generator assembly In relation to the direction, the position in the axial direction (length direction) of the heat transfer tube 5 obtained by the feed speed of the probe feeder 32 and the detection timing of the flaw detector 33, or obtained by an encoder provided in the probe feeder 32. The coil of each group (24 groups) of the array type probe 31 at the position in the axial direction of the heat transfer tube which is the position in the axial direction of the heat transfer tube 5 (indicated by the distance [mm] from the entrance 7A side in FIG. 7) The detected waveform detected in step 1 is stored. In FIG. 7, the shaded area “3” in the axial direction of the heat transfer tube shows different results from the pre-assembly inspection results when the post-assembly inspection results are compared with the pre-assembly inspection results. Indicates that the position is In addition, the shaded portion of the waveform “heat transfer tube circumferential direction No. 04” is the heat transfer tube circumferential direction No. 04. The position 04 indicates the position of the marking portion 38a of the inspection plate 38.

  As described above, the heat transfer tube inspection method according to the present embodiment is performed by the eddy current flaw detection apparatus 30 having the array type probe 31 inserted into the heat transfer tube 5 before the heat transfer tube 5 is assembled to the steam generator 1. The step of inspecting the heat transfer tube 5 and the heat transfer tube 5 in which the noise signal exceeding the predetermined amplitude is detected by the inspection is excluded from the assembly target, while the heat transfer tube 5 in which the noise signal within the predetermined amplitude is detected. And a step of creating a database of pre-assembly inspection results relating to the heat transfer tubes 5 to be assembled.

  According to this heat transfer tube inspection method, in addition to deep thinning and extremely deformed tubes, large amplitude noise signals that lower the S / N ratio for small signals from cracks and the like are detected in subsequent inspections. By making the heat transfer tube 5 also an exclusion tube, it is possible to improve the detectability of an inspection signal for inspecting the heat transfer tube 5 and improve the soundness of the steam generator 1. In addition, the heat transfer tube 5 in which a noise signal within a predetermined amplitude is detected is an assembly target, and the pre-assembly inspection results regarding the heat transfer tube 5 that is the assembly target are compiled into a database. It can be used as a reference for inspection after assembly by the same eddy current flaw inspection apparatus 30.

  In addition, the heat transfer tube inspection method according to the present embodiment is a method of assembling the heat transfer tube 5 to the steam generator 1 after the heat transfer tube 5 is assembled to the steam generator 1 and before the steam generator 1 is used. It includes the step of creating a database of the position (steam generator assembly address) and the assembly direction of the heat transfer tubes 5 to the steam generator 1 (steam generator assembly direction).

  According to this heat transfer tube inspection method, after the heat transfer tube 5 is assembled to the steam generator 1, the assembly position of the heat transfer tube 5 to the steam generator 1 and the assembly direction of the heat transfer tube 5 to the steam generator 1 are determined. Since information is obtained, the pre-assembly inspection result can be used more effectively as a reference for subsequent inspection by the same eddy current flaw inspection apparatus for the steam generator 1 after manufacture.

  In addition, the heat transfer tube inspection method of the present embodiment is performed after the heat transfer tube 5 is assembled to the steam generator 1 and before the steam generator 1 is put into service by the eddy current flaw detection apparatus 30. A step of inspecting and obtaining an inspection result after assembly, and a step of creating a database of the inspection result after assembly.

  According to this heat transfer tube inspection method, according to this heat transfer tube inspection method, the same eddy current flaw detection inspection is performed after the heat transfer tube 5 is assembled to the steam generator 1 and before the steam generator 1 is used. By inspecting the heat transfer tube 5 with the device 30, it is possible to compare the heat transfer tube 5 before being assembled to the steam generator 1 and the heat transfer tube 5 after the steam generator 1 has been used.

  Further, the heat transfer tube inspection method of the present embodiment uses the eddy current flaw inspection device 30 to inspect the heat transfer tube 5 after the steam generator 1 assembled with the heat transfer tube 5 is used, and the post-service inspection result is obtained. A step of acquiring, and then a step of reading at least a pre-assembly inspection result and comparing it with a post-service inspection result, and a step of creating a database of the post-service inspection result together with the comparison result.

  Waveforms created in the database include shallow thinning, mild deformation, and mild noise signals. When a slight damage signal is generated in such a part, the S / N generally decreases. Although the detectability deteriorates, according to this heat transfer tube inspection method, a subtle change can be recognized by comparing the pre-assembly inspection result inspected by the same eddy current flaw detection inspection apparatus 30 with the in-service inspection result. This makes it easier to improve the detectability.

  Further, the heat transfer tube inspection method of the present embodiment uses the eddy current flaw detection apparatus 30 in the step of inspecting the heat transfer tube 5 by the eddy current flaw inspection apparatus 30 before assembling the heat transfer pipe 5 to the steam generator 1. It includes a step of placing the heat transfer tube 5 on the inspection plate 38 on which the detectable marking portion 38a is arranged.

  According to this heat transfer tube inspection method, marking is completed simply by placing the heat transfer tube 5 on the inspection plate 38, so that it is not necessary to attach a separate marking. In addition, the marking portion 38a can more accurately calculate the heat transfer tube axis position of the inspection result. Furthermore, since the marking portion 38a comes into contact with the outer peripheral surface of the heat transfer tube 5 and generates a marking signal only in a specific direction of the array probe 31, the circumferential position of the heat transfer tube 5 is also stored as a database item. Is possible. Further, the assembly direction of the heat transfer tube 5 to the steam generator 1 is stored in the storage unit 35 together with the marking portion 38a, so that in the comparison of the inspection results, the inspection results before and after the assembly are minute. By identifying the circumferential position in the signal pattern, and further identifying the physical position in the circumferential direction using the marking signal from one piece, it can also be used to grasp the physical circumferential position with respect to the steam generator 1, This is a clue to understand in detail the events that occur after in-service.

  Further, the heat transfer tube inspection device of the present embodiment includes an eddy current flaw detection device 30 having an array type probe 31 inserted into the heat transfer tube 5, before assembling the heat transfer tube 5 to the steam generator 1, and After the heat tube 5 is assembled, a storage unit 35 that stores the inspection results obtained by inspecting the heat transfer tube 5 by the eddy current flaw inspection apparatus 30 as a database and a comparison unit 37 that compares the inspection results are provided.

  According to this heat transfer tube inspection apparatus, before assembling the heat transfer tube 5 to the steam generator 1, in addition to deep thinning and extreme deformation tubes, S / N against small signals from cracks and the like in subsequent inspections. It becomes possible to detect a noise signal having a large amplitude that lowers the ratio. If the heat transfer tube 5 from which this large-amplitude noise signal has been detected is an excluded tube, it is possible to improve the detectability of the inspection signal for inspecting the heat transfer tube 5 and improve the soundness of the steam generator 1. become. In addition, the heat transfer tube 5 in which a noise signal within a predetermined amplitude is detected is an assembly target, and the pre-assembly inspection results regarding the heat transfer tube 5 that is the assembly target are compiled into a database. It can be used as a reference for inspection after assembly by the same eddy current flaw inspection apparatus 30.

  Further, in the heat transfer tube inspection device of the present embodiment, the marking portion 38a that can be detected by the eddy current flaw detection device 30 is arranged, and the heat transfer tube 5 is placed in the inspection before being assembled to the steam generator 1. The inspection plate 38 is provided.

  According to this heat transfer tube inspection device, the marking is completed simply by placing the heat transfer tube 5 on the inspection plate 38, so that it is not necessary to attach a separate marking. In addition, the marking portion 38a can more accurately calculate the heat transfer tube axis position of the inspection result. Furthermore, since the marking portion 38a comes into contact with the outer peripheral surface of the heat transfer tube 5 and generates a marking signal only in a specific direction of the array probe 31, the circumferential position of the heat transfer tube 5 is also stored as a database item. Is possible. Further, the assembly direction of the heat transfer tube 5 to the steam generator 1 is stored in the storage unit 35 together with the marking portion 38a, so that in the comparison of the inspection results, the inspection results before and after the assembly are minute. By identifying the circumferential position in the signal pattern, and further identifying the physical position in the circumferential direction using the marking signal from one piece, it can also be used to grasp the physical circumferential position with respect to the steam generator 1, This is a clue to understand in detail the events that occur after in-service.

  In the heat transfer tube inspection apparatus according to the present embodiment, the inspection plate 38 is arranged in the same positional relationship as the tube support plate 6 in which the marking portion 38 a supports the heat transfer tube 5 in the steam generator 1.

  According to this heat transfer tube inspection apparatus, since the marking is performed at the same position as the tube support plate 6, the heat transfer tube shaft position is determined by the inspection before being assembled to the steam generator 1 and the inspection after being assembled to the steam generator 1. Therefore, the effect of accurately calculating the heat transfer tube shaft position can be remarkably obtained.

DESCRIPTION OF SYMBOLS 1 Steam generator 5 Heat exchanger tube 6 Tube support plate 30 Eddy current flaw detector 31 Array type probe 31a Cable 32 Probe feeder 32a Roller 33 Flaw detector 34 Control means 35 Storage means 36 Input means 37 Comparison means 38 Inspection plate 38a Marking Part

Claims (8)

A step of inspecting the heat transfer tube by an eddy current flaw inspection apparatus having an array type probe inserted into the heat transfer tube before assembling the heat transfer tube to the heat exchanger;
Next, while excluding the heat transfer tube from which the noise signal exceeding a predetermined amplitude is detected by the inspection from the assembly target, the step of assembling the heat transfer tube from which the noise signal within the predetermined amplitude is detected;
Next, a step of creating a database of pre-assembly inspection results relating to the heat transfer tubes that are to be assembled; and
A method for inspecting a heat transfer tube, comprising: After assembling the heat transfer tube to the heat exchanger and before using the heat exchanger,
The method for inspecting a heat transfer tube according to claim 1, further comprising a step of creating a database of an assembly position of the heat transfer tube to the heat exchanger and an assembly direction of the heat transfer tube to the heat exchanger. After assembling the heat transfer tube to the heat exchanger and before using the heat exchanger, inspecting the heat transfer tube by the eddy current flaw inspection device and obtaining a post-assembly inspection result;
Next, a step of creating a database of the post-assembly inspection results,
The heat transfer tube inspection method according to claim 2, further comprising: After the heat exchanger assembled with the heat transfer tube is used, the step of inspecting the heat transfer tube by the eddy current flaw detection device and obtaining the post-service inspection results;
Next, at least reading out the pre-assembly inspection result and comparing it with the in-service inspection result;
Next, a step of creating a database of the in-service inspection results together with the comparison results;
The heat transfer tube inspection method according to any one of claims 1 to 3, wherein the heat transfer tube inspection method is included.   In the step of inspecting the heat transfer tube by the eddy current flaw inspection apparatus before assembling the heat transfer tube to the heat exchanger, the upper surface of the inspection plate on which the marking portion that can be detected by the eddy current flaw inspection apparatus is arranged The method for inspecting a heat transfer tube according to any one of claims 1 to 4, further comprising a step of placing the heat transfer tube. An eddy current flaw detection apparatus having an array type probe inserted into a heat transfer tube;
Storage means for storing the test results obtained by inspecting the heat transfer tubes by the eddy current flaw inspection apparatus before the heat transfer tubes are assembled in the heat exchanger and after the heat transfer tubes are assembled;
A comparison means for comparing each test result;
A heat transfer tube inspection device comprising:   A marking portion that can be detected by the eddy current flaw inspection apparatus is disposed on the upper surface, and includes an inspection plate on which the heat transfer tube is placed on the upper surface in an inspection before being assembled to the heat exchanger. The heat transfer tube inspection apparatus according to claim 6.   The said inspection plate is arrange | positioned in the same positional relationship as the pipe support plate which the said marking part supports the said heat exchanger tube in the said heat exchanger, The inspection apparatus of the heat exchanger tube of Claim 7 characterized by the above-mentioned.

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