Vortex detection signal acquisition method for double rotating probes in pipe expansion area of steam generator

Abstract

The invention relates to the field of nondestructive testing, in particular to a method for collecting eddy current testing signals of double rotating probes in an expansion tube area of a steam generator. The method comprises the following steps that: signal acquisition software is connected with at least two eddy current instrument hosts, and each eddy current instrument host drives one rotary probe to perform signal acquisition; message channels of the eddy current instrument host are mutually independent; signal features are manually collected and calibrated, and signal feature values are obtained; the robot carries the probe to a detection pipe position, and controls the corresponding probe to execute detection according to a detection plan made by the plan management software; when detection is executed, the probe is remotely and automatically controlled to move, eddy current signals are collected, the collected eddy current signals are measured, measured values are matched with the signal characteristic values, and the real-time movement position of the probe is obtained; according to the real-time movement position, a probe is controlled to complete all detection in a tube plate area in combination with a detection plan. According to the invention, automatic signal acquisition is realized, and the detection efficiency and precision are improved.

Description

Technical Field

[0001] The present invention relates to the field of nondestructive testing, and in particular to a method for collecting eddy current detection signals using double-rotating probes in a steam generator expansion zone. Background Art

[0002] According to the in-service inspection rules for nuclear island mechanical equipment in pressurized water reactor nuclear power plants and the in-service inspection program for nuclear power units, in addition to conducting bobbin probe eddy current inspections on steam generator heat transfer tubes during each refueling overhaul, all units must also complete a rotating eddy current inspection of 100% of the transition sections of the steam generator tube sheet expansion zone before the tenth annual overhaul. Due to the high number of rotating eddy current inspections required and the low efficiency of rotating inspection technology, rotating eddy current inspections of steam generators are often performed at the secondary critical path of refueling overhauls.

[0003] The steam generator rotating inspection system is complex to control and difficult to locate. The tube sheet expansion area inspection has always been carried out using a single-probe manual control inspection technology, which is very inefficient. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for collecting eddy current detection signals of a steam generator expansion tube area with double rotating probes, which realizes automatic signal collection and improves detection efficiency and accuracy.

[0005] The present invention provides a method for collecting eddy current detection signals of a steam generator expansion tube area using a double-rotating probe, comprising the following steps: Step 1: The signal acquisition software is connected to at least two eddy current instrument hosts. Each eddy current instrument host drives a rotating probe to collect signals. The message channels of the eddy current instrument hosts are independent of each other. Step 2: Manually collect signal features and calibrate them to obtain signal feature values; Step 3: The robot carries the probe to the inspection tube position and controls the corresponding probe to perform the inspection according to the inspection plan formulated by the planning management software; When performing the test, the probe movement is remotely and automatically controlled to collect eddy current signals, the collected eddy current signals are measured, and the measured values are matched with the signal characteristic values to obtain the real-time movement position of the probe; According to the real-time movement position, the probe is controlled to complete all inspections in the tube sheet area in combination with the inspection plan.

[0006] In a specific embodiment of the present invention, the step 1 specifically includes: The signal acquisition software creates two eddy current instrument clients in parallel, and executes the eddy current instrument link library initialization function. After the link library function initialization is completed, the eddy current instrument control interface and eddy current instrument control method are provided; Create two eddy current instrument objects through the link library, bind the two callback functions of the signal acquisition software main program to the corresponding eddy current instruments, and each callback function is based on the data returned by one eddy current instrument; The handles of the two eddy current instruments are returned to the main program; The main program establishes two independent message processing channels through two handles.

[0007] In a specific embodiment of the present invention, step 2 specifically includes: Step 2-1: Manually control the probe movement to collect eddy current signals from the entire tube sheet area, with the movement range covering the expansion zone and transition zone; Step 2-2: Select the pipe end signal of the main detection frequency channel, move the probe to the pipe end, measure the original voltage value of the signal, perform normalization processing, obtain Ve0 as the pipe end structural signal feature, and extract the signal length, phase and trend at the same time; Step 2-3: Select the expansion point signal of the tube, move the probe to the expansion point, measure the signal and perform normalization processing to obtain Vt1 as the structural signal feature of the expansion point, and extract the length and phase features of the expansion point signal at the same time; Perform steps 2-1 to 2-3 once for each probe.

[0008] In a specific embodiment of the present invention, in step 3, the measured values include normalized volt value, signal trend characteristics, signal length and phase.

[0009] In a specific embodiment of the present invention, in step 3, when performing matching, the matching is deemed to be successful when the matching redundancy is not less than 85%, and the real-time motion position of the probe can be obtained at this time.

[0010] In a specific embodiment of the present invention, step 3 specifically includes: When the probe position is detected in real time, when the probe reaches the expansion point, the probe continues to move for no less than 25.4 mm and then stops, depending on the probe speed and sampling rate. Set the pusher movement speed to the data recording speed, start recording the eddy current instrument data, start the probe rotation, and move the probe back; after the back distance is not less than 50.8mm, stop the probe movement, stop the rotating probe rotation, and stop data recording; Set the pusher movement speed to the probe movement speed, control the probe to continue to move backward, and continue to collect signals for measurement. The measured values include normalized volts, signal trend characteristics, signal length, and phase. Match the measured values with the pipe end signal characteristic values in step 2. A match is considered successful when the matching redundancy is not less than 85%. When the match is successful, it is considered that the probe has reached the pipe end. After the probe reaches the pipe end, it continues to run a certain distance and then stops moving.

[0011] In a specific embodiment of the present invention, after the probe reaches the pipe end, the distance it continues to move is not less than the distance from the probe coil to the probe top.

[0012] In a specific embodiment of the present invention, as the probe moves forward, feature matching and recognition of the signal are performed in real time. When the pipe end signal is first recognized, the data point index is recorded. As the probe continues to move forward, the distance between the current data point and the pipe end data point is calculated in real time: The distance between the current data point and the pipe end data point = (current data point index - pipe end data point index) / (eddy current instrument sampling rate / probe speed).

[0013] In a specific embodiment of the present invention, in step 3, a safe acquisition signal range is set. When the distance between the current data point and the pipe end data point exceeds the safe acquisition signal range, the forward movement of the probe is automatically stopped and the user is prompted to perform operational intervention.

[0014] The present invention provides a double-rotating probe eddy current detection signal acquisition device for a steam generator expansion tube area, comprising: The positioning robot is equipped with dual rotating probes to perform front-end inspection of the tube sheet area; Connect the positioning robot control box to the positioning robot to realize the control of the positioning robot's movement and control the robot to carry the dual rotating probe to the specified inspection plan; The pusher is connected to the double rotating probe via a cable; The off-island centralized box includes data analysis software, eddy current signal acquisition software, plan management software, and positioning robot control software; The eddy current acquisition software is connected to the dual eddy current instrument host and the pusher control box to synchronize the probe movement and signal acquisition.

[0015] Compared with the prior art, the method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to the present invention has the following beneficial effects: (1) Parallel acquisition of dual-rotating probe signals and high-precision automatic speed control of dual-rotating probe motion. Fully automatic acquisition of dual-rotating probe signals is achieved through parallel acquisition of dual-rotating probe signals and automatic control of dual-rotating probe motion. (2) Based on the comparison between the signal characteristic value and the real-time measurement value, the real-time motion position of the probe is automatically obtained, thereby automatically controlling the forward and backward movement of the probe, avoiding the errors that may occur in manual collection by the operator, relieving the pressure on the collection personnel and improving work efficiency; (3) The acquisition signal recognition is more real-time. Once the probe reaches the feature, the relevant digital signal can be converted and recognized by the computer in real time, which improves the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram showing a double-rotating probe eddy current detection signal acquisition device for a steam generator expansion tube area; Figure 2 Indicates the signal diagram of the starting point of expansion (TTS) from the tube sheet area to the tube expansion area; Figure 3 Represents the decomposition diagram of a single component signal; Figure 4 It shows the flow chart of automatic acquisition by rotating probe. DETAILED DESCRIPTION

[0017] In order to further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the present invention.

[0018] The transition section of the steam generator tube sheet expansion area refers to 25.4mm before and after the expansion point.

[0019] An embodiment of the present invention discloses a method for collecting eddy current detection signals of a steam generator expansion tube area using a dual-rotating probe, comprising the following steps: Step 1: The signal acquisition software is connected to at least two eddy current instrument hosts, and each eddy current instrument host drives a rotating probe for signal acquisition; Specifically, the signal acquisition software creates two eddy current instrument clients in parallel, and the signal acquisition software executes the eddy current instrument link library initialization function. After the link library function initialization is completed, the eddy current instrument control interface and eddy current instrument control method are provided; Create two eddy current instrument objects through the link library, bind the two callback functions of the signal acquisition software main program to the corresponding eddy current instruments, and each callback function is based on the data returned by one eddy current instrument; The handles of the two eddy current instruments are returned to the main program; The main program establishes two independent message processing channels through two handles; Step 2: Manually collect signal features and calibrate them to obtain signal feature values; Step 2-1: Manually control the probe movement to collect eddy current signals from the entire tube sheet area. The movement range covers the expansion zone and transition zone. Specifically, the movement range is not less than 25.4mm from the tube end to the tube sheet area. Refer to the signal diagram Figure 2 ; Step 2-2: Select the pipe end signal of the main detection frequency channel, move the probe to the pipe end, measure the original voltage value of the signal, perform normalization processing, obtain Ve0 as the pipe end structural signal feature, and extract the signal length, phase and trend at the same time; The trend refers to the decomposition of single component signals, see Figure 3 , after decomposition, the signal shows different combination characteristics of three trends: flat, rising and falling; Step 2-3: Select the expansion point signal of the tube, move the probe to the expansion point, measure the signal and perform normalization processing to obtain Vt1 as the structural signal feature of the expansion point, and extract the length and phase features of the expansion point signal at the same time; Perform steps 2-1 to 2-3 once for each probe.

[0020] This step collects the signal characteristics of the expansion point at the end of the heat transfer tube and the expansion area as the standard for signal comparison in subsequent automatic collection, and determines the movement mode of the probe based on this standard.

[0021] Step 3: The robot carries the probe to the inspection tube position and controls the corresponding probe to perform the inspection according to the inspection plan formulated by the planning management software; You can choose single probe detection or double probe detection; Specifically, the dual eddy current instrument host is turned on, the probe is remotely and automatically controlled to move forward, eddy current signals are collected in real time, the collected signals are measured, and the measured values are matched with the signal characteristic values in step 2. A successful match is determined when the matching redundancy is not less than 85%, and the successful match is used as the real-time movement position of the probe; See also Figure 4 When the probe reaches the expansion point, it moves for at least 25.4 mm before stopping, depending on the probe speed and sampling rate. Set the pusher movement speed to the data recording speed, start recording the eddy current instrument data, start the probe rotation, and move the probe back; after the back distance is not less than 50.8mm, stop the probe movement, stop the rotating probe rotation, and stop data recording; Set the pusher movement speed to the probe movement speed, control the probe to continue to move backward, and continue to collect signals for measurement. The measured values include normalized volts, signal trend characteristics, signal length, and phase. Match the measured values with the pipe end signal characteristic values in step 2. A match is considered successful when the matching redundancy is not less than 85%. When the match is successful, it is considered that the probe has reached the pipe end. After the probe reaches the pipe end, it continues to move for a certain distance and then stops moving; The distance is not less than the distance from the probe coil to the probe tip.

[0022] As the probe moves forward, it performs feature matching and recognition on the signal in real time. When the pipe end signal is recognized for the first time, the data point index is recorded. As the probe continues to move forward, the distance between the current data point and the pipe end data point is calculated in real time: Distance between current data point and pipe end data point = (current data point index - pipe end data point index) / (eddy current instrument sampling rate / probe speed) When the distance exceeds the set safe signal acquisition range, the probe's forward movement will automatically stop and the user will be prompted to intervene.

[0023] The embodiment of the present invention discloses a double rotating probe eddy current detection signal acquisition device for a steam generator expansion tube area, such as Figure 1 As shown, it is deployed in the evaporator water chamber, evaporator room, nuclear island corridor and off-island centralized box, including: A positioning robot is deployed in the evaporator water chamber. Equipped with dual rotating probes, the positioning robot performs front-end inspection of the tube sheet area within the steam generator water chamber. A dual-rotating probe pusher and cable are deployed in the evaporator room, and the pusher is connected to the probe through the cable; The nuclear island corridor is deployed with a positioning robot control box, fiber optic communication equipment, a dual eddy current instrument host, and a pusher and puller control box; The positioning robot control box controls the movement of the positioning robot and controls the robot to carry the probe to the specified inspection plan; The eddy current acquisition software is connected to the dual eddy current instrument host and the pusher control box to synchronize the probe movement and signal acquisition; The pusher control box is used to control the pusher; The main unit of the dual eddy current instrument is connected to the centralized box outside the island via optical fiber communication equipment to upload the pre-processed eddy current signal; The off-island centralized box includes data analysis software, signal acquisition software, planning management software, and positioning robot control software.

[0024] In order to further understand the present invention, the eddy current detection signal acquisition method of the double rotating probe in the expansion tube area of the steam generator provided by the present invention is described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0025] Example 1 Step 1: The entire detection system is deployed in the evaporator water chamber, evaporator room, nuclear island corridor, and off-island centralized cabinet. The evaporator water chamber will be equipped with a positioning robot and monitoring system; the evaporator room will be equipped with a dual-rotating probe pusher and cable; the nuclear island corridor will be equipped with a positioning robot control box, fiber optic communication equipment, and dual eddy current instruments; the off-island centralized cabinet will include data analysis software, signal acquisition software, and plan management software; The positioning robot is equipped with dual rotating probes.

[0026] The plan management software creates the inspection plan, the signal acquisition software performs fully automatic acquisition, and the signal analysis software performs defect analysis; Create two clients connected to the eddy current instrument. The main program uses two handles to establish two independent message processing channels to achieve instrument communication. Step 2: Turn on the eddy current instrument, control the probe movement, and collect eddy current signals from the entire tube sheet area. The eddy current signal of a heat transfer tube is collected, and the tube end signal voltage of 500.45V is measured as the tube end voltage feature. The data point length and change trend features are also extracted. The TTS signal feature of the starting expansion point is also extracted, and the voltage is 51.60V. Step 3: During automatic acquisition, the probe moves forward, and the acquisition software determines the characteristics of the acquired signal in real time. When the signal measurement voltage is between 450 and 550 V, and other characteristics match the pipe end signal characteristics in Step 2, it is considered to have reached the pipe end. The probe continues to move forward. When the measured voltage is between 46.44 and 56.76 V, and other characteristics match the expansion point signal characteristics in Step 2, it is considered to have reached the expansion point. The minimum acquisition range of the expansion signal is 25.4 mm before and after this point. Step 4: Control the probe to move to a position no less than 25.4mm above the expansion point. The direction away from the pipe end is defined as the upward direction. Start the probe rotation and set the probe movement speed to a low speed of 3mm / min. Execute the probe backward and record the collected data. The collection range covers 25.4mm above and below the expansion point. Step 5: After the local data is recorded, set the pusher speed to 150 mm / min, stop the probe rotation, and quickly move the probe back; Step 6: Use the same detection method as in step 3 to confirm that the probe reaches the pipe end, run the probe out of the pipe end, stop the probe movement, and complete the current pipe detection; Step 7: The positioning robot moves, and the carried probe moves to the next detection tube, and continues to perform automatic acquisition until all acquisition plans are completed.

[0027] After data recording is completed, the probe quickly retreats until it detects the tube end signal, exits the tube end, and completes the detection of this heat transfer tube. When the probe moves forward, the real-time position of the probe is calculated to prevent the probe from exceeding the collection range and causing damage.

[0028] At present, the automatic data collection system based on this method is mainly used in the eddy current detection site of Qinshan No. 2 Plant, shortening the overhaul cycle.

[0029] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0030] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator, characterized in that: The following steps are involved: Step 1: The signal acquisition software is connected to at least two eddy current instrument hosts. Each eddy current instrument host drives a rotating probe to collect signals. The message channels of the eddy current instrument hosts are independent of each other. Step 2: Manually collect signal features and calibrate them to obtain signal feature values; Step 3: The robot carries the probe to the inspection tube position and controls the corresponding probe to perform the inspection according to the inspection plan formulated by the planning management software; When performing the test, the probe movement is remotely and automatically controlled to collect eddy current signals, the collected eddy current signals are measured, and the measured values are matched with the signal characteristic values to obtain the real-time movement position of the probe; According to the real-time movement position, the probe is controlled to complete all inspections in the tube sheet area in combination with the inspection plan.

2. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 1, characterized in that: Described step 1 specifically comprises: The signal acquisition software creates two eddy current instrument clients in parallel, and executes the eddy current instrument link library initialization function. After the link library function initialization is completed, the eddy current instrument control interface and eddy current instrument control method are provided; Create two eddy current instrument objects through the link library, bind the two callback functions of the signal acquisition software main program to the corresponding eddy current instruments, and each callback function is based on the data returned by one eddy current instrument; The handles of the two eddy current instruments are returned to the main program; The main program establishes two independent message processing channels through two handles.

3. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 1, characterized in that: The step 2 specifically includes: Step 2-1: Manually control the probe movement to collect eddy current signals from the entire tube sheet area, with the movement range covering the expansion zone and transition zone; Step 2-2: Select the pipe end signal of the main detection frequency channel, move the probe to the pipe end, measure the original voltage value of the signal, perform normalization processing, obtain Ve0 as the pipe end structural signal feature, and extract the signal length, phase and trend at the same time; Step 2-3: Select the expansion point signal of the tube, move the probe to the expansion point, measure the signal and perform normalization processing to obtain Vt1 as the structural signal feature of the expansion point, and extract the length and phase features of the expansion point signal at the same time; Perform steps 2-1 to 2-3 once for each probe.

4. The method for collecting eddy current detection signals of a double rotating probe in the expansion tube area of a steam generator according to claim 1, characterized in that: In step 3, the measured values include normalized volt value, signal trend characteristics, signal length and phase.

5. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 1, characterized in that: In step 3, when matching is performed, the matching is deemed to be successful when the matching redundancy is not less than 85%, and the real-time motion position of the probe can be obtained at this time.

6. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 1, characterized in that: The step 3 specifically includes: When the probe position is detected in real time, when the probe reaches the expansion point, the probe continues to move for no less than 25.4 mm and then stops, depending on the probe speed and sampling rate. Set the pusher movement speed to the data recording speed, start recording the eddy current instrument data, start the probe rotation, and move the probe back; after the back distance is not less than 50.8mm, stop the probe movement, stop the rotating probe rotation, and stop data recording; Set the pusher movement speed to the probe movement speed, control the probe to continue to move backward, and continue to collect signals for measurement. The measured values include normalized volts, signal trend characteristics, signal length, and phase. Match the measured values with the pipe end signal characteristic values in step 2. A match is considered successful when the matching redundancy is not less than 85%. When the match is successful, it is considered that the probe has reached the pipe end. After the probe reaches the pipe end, it continues to run a certain distance and then stops moving.

7. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 6, characterized in that: After the probe reaches the pipe end, the distance it continues to run is not less than the distance from the probe coil to the probe top.

8. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 1, characterized in that: As the probe moves forward, it performs feature matching and recognition on the signal in real time. When the pipe end signal is recognized for the first time, the data point index is recorded. As the probe continues to move forward, the distance between the current data point and the pipe end data point is calculated in real time: The distance between the current data point and the pipe end data point = (current data point index - pipe end data point index) / (eddy current instrument sampling rate / probe speed).

9. The method for collecting eddy current detection signals using dual rotating probes in the expansion tube area of a steam generator according to claim 8, characterized in that: In step 3, a safe acquisition signal range is set. When the distance between the current data point and the pipe end data point exceeds the safe acquisition signal range, the forward movement of the probe is automatically stopped and the user is prompted to perform operational intervention.

10. A dual-rotating probe eddy current detection signal acquisition device for a steam generator expansion tube area, characterized in that: include: The positioning robot is equipped with dual rotating probes to perform front-end inspection of the tube sheet area; Connect the positioning robot control box to the positioning robot to realize the control of the positioning robot's movement and control the robot to carry the dual rotating probe to the specified inspection plan; The pusher is connected to the double rotating probe via a cable; The off-island centralized box includes data analysis software, eddy current signal acquisition software, plan management software, and positioning robot control software; The eddy current acquisition software is connected to the dual eddy current instrument host and the pusher control box to synchronize the probe movement and signal acquisition.

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