Internal penetrating type detection probe

Abstract

The invention relates to an internal penetrating type detection probe which comprises a probe body used for entering a pipeline, and an induction signal generation unit and an induction signal processing unit which are arranged on the probe body, the induction signal generation unit comprises a first PCB and a plurality of tunnel magnetoresistive sensors which are circumferentially arranged on the first PCB along a preset circumference, and the preset circumference is formed by taking the center of the cross section of the probe body as a circle center and a preset length as a radius; the induction signal processing unit comprises a second PCB and a signal processing circuit arranged on the second PCB. The signal processing circuit is electrically connected with the plurality of tunnel magnetoresistive sensors and is used for receiving induction signals generated by the tunnel magnetoresistive sensors and generating corresponding detection signals. According to the invention, detection of tiny defects in the pipeline can be realized through high-density component layout.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline detection, and more particularly to an internal penetration detection probe. Background Art

[0002] The steam generator heat transfer tube is a nuclear primary component of a pressurized water reactor. At present, it is mainly made of nickel-based alloys and stainless steel. It undertakes the heat exchange task between the primary and secondary sides. The heat exchange area accounts for more than 70% of the total pressure boundary area of ​​the primary circuit. It is the second barrier to prevent nuclear leakage, and its safety importance is self-evident.

[0003] As the service life of pressurized water reactor units increases, different types of degradation defects are detected during the periodic shutdown and overhaul in-service inspection stage. According to the operating experience, the degradation defects of steam generator heat transfer tubes are mainly: thinning, pitting, stress corrosion cracking, wear and impact (dent), etc., as shown in the figure below. The occurrence of these defects poses a great safety risk to the safe operation of nuclear power plants.

[0004] At present, eddy current testing is the main nondestructive testing method for monitoring the operating status of steam generator heat transfer tubes. Existing eddy current testing array probes use induction coils to obtain signals. The measurement sensitivity of the coil is proportional to its diameter, making it difficult to simultaneously obtain high sensitivity and high spatial resolution. In addition, during the quantitative defect analysis process, it is easily affected by non-ideal experimental conditions and multi-parameter coupling effects, and has insufficient ability to quantitatively characterize the location and size of tiny defects. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an internal penetration detection probe in view of the above-mentioned partial technical defects of the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is: constructing an internal penetration detection probe, comprising: a probe body for entering the interior of a pipeline, and an induction signal generating unit and an induction signal processing unit arranged on the probe body;

[0007] The sensing signal generating unit includes a first PCB board and a plurality of tunnel magnetoresistive sensors arranged circumferentially along a preset circumference on the first PCB board, wherein the preset circumference is a circumference formed with the center of the cross section of the probe body as the center and a preset length as the radius;

[0008] The sensing signal processing unit includes a second PCB board and a signal processing circuit arranged on the second PCB board;

[0009] The signal processing circuit is electrically connected to the plurality of tunnel magnetoresistive sensors and is used for receiving the sensing signals generated by the tunnel magnetoresistive sensors and generating corresponding detection signals.

[0010] Preferably, in the internal penetration detection probe described in the present invention, the plurality of tunnel magnetoresistive sensors are arranged at equal intervals on the preset circle.

[0011] Preferably, in the internal penetration detection probe of the present invention, the tunnel magnetoresistive sensor is arranged on the first PCB board by gold wire bonding;

[0012] The signal processing circuit is electrically connected to the tunnel magnetoresistive sensor via a gold wire corresponding to the tunnel magnetoresistive sensor.

[0013] Preferably, in the internal penetration detection probe of the present invention, the signal processing circuit includes a channel switching circuit including a plurality of input terminals and an output terminal, as well as a signal bias circuit, a filtering circuit and a signal amplification circuit;

[0014] Each input end of the channel switching circuit is respectively connected to a corresponding tunnel magnetoresistance sensor, and the output end of the channel switching circuit is connected to the signal bias circuit. The channel switching circuit is used to switch one of the input ends to be connected to the output end according to a switching instruction, so that the signal bias circuit receives the sensing signal of the corresponding tunnel magnetoresistance sensor;

[0015] The signal amplifying circuit is connected to the filtering circuit and the signal biasing circuit in sequence, and is used to amplify the sensing signal after being biased by the signal biasing circuit and filtered by the filtering circuit, and generate a corresponding detection signal.

[0016] Preferably, in the internal penetration detection probe of the present invention, the channel switching circuit includes a multiplexer and a controller;

[0017] The input ends of the multiplexer are respectively connected to a corresponding tunnel magnetoresistive sensor, and the output end of the multiplexer is connected to the signal bias circuit;

[0018] The control end of the multiplexer is connected to the controller and is used to receive a control signal from the controller to perform path switching.

[0019] Preferably, in the internal penetration detection probe of the present invention, the signal bias circuit includes a first operational amplifier chip, a first resistor, a second resistor and a third resistor;

[0020] The in-phase input terminal of the first operational amplifier chip is connected to the output terminal of the channel switching circuit and the first terminal of the first resistor;

[0021] The inverting input terminal of the first operational amplifier chip is connected to the first end of the second resistor and the first end of the third resistor;

[0022] The second end of the first resistor and the second end of the second resistor are connected to a power supply voltage, and the second end of the third resistor and the output end of the first operational amplifier chip are connected to the filter circuit.

[0023] Preferably, in the internal penetration detection probe of the present invention, the filtering circuit includes a first capacitor and a fourth resistor;

[0024] A first end of the first capacitor is connected to the signal bias circuit, a second end of the first capacitor is connected to a first end of the fourth resistor and the signal amplification circuit, and a second end of the fourth resistor is grounded.

[0025] Preferably, in the internal penetration detection probe of the present invention, the signal amplification circuit includes a second operational amplifier chip, a fifth resistor and a sixth resistor;

[0026] The non-inverting input terminal of the second operational amplifier chip is connected to the filter circuit, the inverting input terminal of the second operational amplifier chip is connected to the first end of the fifth resistor and the first end of the sixth resistor, the second end of the fifth resistor is grounded, and the output terminal of the second operational amplifier chip is connected to the second end of the sixth resistor and is used to output the detection signal.

[0027] Preferably, in the internal penetration detection probe described in the present invention, the probe body includes: a first cavity for accommodating the sensing signal generating unit, a second cavity for accommodating the sensing signal processing unit, a first connecting portion connecting the first cavity and the second cavity, and a second connecting portion connecting the second cavity; and

[0028] A first cable disposed in the first connection portion for electrically connecting the signal processing circuit with the plurality of tunnel magnetoresistive sensors;

[0029] A second cable is disposed in the second connection portion and is used to implement the detection signal output of the signal processing circuit.

[0030] Preferably, in the internal penetration detection probe of the present invention, the probe body further comprises: a first support structure arranged at two ends of the first cavity and / or a second support structure arranged at two ends of the second cavity;

[0031] When the first cavity is located in the pipe, the first support structure forms a fixed positional relationship with the inner wall of the pipe;

[0032] When the second cavity is located in the pipe, the second supporting structure forms a fixed positional relationship with the inner wall of the pipe.

[0033] The internal penetration detection probe implemented in the present invention has the following beneficial effects: the detection of tiny defects in the pipeline is realized through the high-density component layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0035] Figure 1 It is a structural schematic diagram of an embodiment of an internal penetration detection probe of the present invention;

[0036] Figure 2 yes Figure 1 A schematic structural diagram of an embodiment of an induction signal generating unit;

[0037] Figure 3 yes Figure 1 A logic block diagram of an embodiment of a sensing signal processing unit;

[0038] Figure 4 yes Figure 1 A circuit schematic diagram of an embodiment of an induction signal processing unit;

[0039] Figure 5 It is a structural schematic diagram of another embodiment of an internal penetration detection probe of the present invention. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0041] like Figure 1 FIG. 1 shows an embodiment of an internal penetration detection probe of the present invention. Figure 1 In one embodiment of an internal penetration detection probe of the present invention shown in FIG, the probe comprises: a probe body 100 for entering the interior of a pipeline, and an induction signal generating unit 200 and an induction signal processing unit 300 disposed on the probe body 100; Figure 2 As shown, the induction signal generating unit 200 includes a first PCB board 210 and a plurality of tunnel magnetoresistive sensors 220 arranged circumferentially along a preset circumference on the first PCB board 210, wherein the preset circumference is a circumference formed with the center of the cross section of the probe body 100 as the center and a preset length as the radius; the induction signal processing unit 300 includes a second PCB board and a signal processing circuit arranged on the second PCB board; the signal processing circuit is electrically connected to the plurality of tunnel magnetoresistive sensors 220, and is used to receive the induction signals generated by the tunnel magnetoresistive sensors 220 and generate corresponding detection signals.

[0042] Specifically, when the detection probe is working, the probe body 100 enters the interior of the pipeline. When the probe body 100 enters the interior of the pipeline and when the detection probe is working, the induction signal generating unit 200 provided on the probe body 100 generates a corresponding induction signal according to the internal environment of the pipeline. The induction signal processing unit 300 receives the induction signal and processes it to obtain a corresponding detection signal. In the actual working process, it includes but is not limited to receiving the detection signal through an eddy current meter to display the corresponding detection results, such as generating a corresponding visualized magnetic field three-dimensional image, so as to analyze the internal state of the pipeline according to the image.

[0043] The induction signal generating unit 200 is composed of a plurality of tunneling magnetic resistance sensors 220 (TMR), so as to detect the magnetic field through the tunneling magnetic resistance sensors 220 to obtain the corresponding induction signal. All the tunneling magnetic resistance sensors 220 are arranged along the circumference on the first PCB board 210. In order to ensure that the distances between all the tunneling magnetic resistance sensors 220 and the inner wall of the pipeline are equal or as equal as possible, the center of the circle formed by the tunneling magnetic resistance sensor 220 is set to coincide with the center of the probe body 100. The radius of the circle can be set as needed to be compatible with as many types of pipelines as possible. The induction signal processing unit 300 includes a signal processing circuit arranged on the second PCB board, and the signal processing circuit is electrically connected to all the tunneling magnetic resistance sensors 220 to receive the induction signal generated by the tunneling magnetic resistance sensor 220.

[0044] In one embodiment, the plurality of tunnel magnetoresistive sensors 220 are arranged at equal intervals on the preset circumference. That is, when the tunnel magnetoresistive sensors 220 form a circumference, the tunnel magnetoresistive sensors 220 are equidistant from each other. In a specific embodiment, the number of tunnel magnetoresistive sensors 220 is 48, and the 48 tunnel magnetoresistive sensors 220 are arranged at equal intervals to form a circumference.

[0045] In one embodiment, the tunnel magnetoresistive sensor 220 is disposed on the first PCB board 210 by gold wire bonding; the signal processing circuit is electrically connected to the tunnel magnetoresistive sensor 220 through the gold wire corresponding to the tunnel magnetoresistive sensor 220. Specifically, the tunnel magnetoresistive sensor 220 is connected to the first PCB by gold wire bonding, and the second PCB board is connected to the first PCB by wires, and finally the signal processing circuit is electrically connected to the tunnel magnetoresistive sensor 220 by the gold wire.

[0046] like Figure 3As shown, in one embodiment, the signal processing circuit includes a channel switching circuit 310 including a plurality of input terminals and an output terminal, as well as a signal bias circuit 320, a filter circuit 330 and a signal amplification circuit 340; each input terminal of the channel switching circuit 310 is respectively connected to a tunnel magnetoresistance sensor 220, and the output terminal of the channel switching circuit 310 is connected to the signal bias circuit 320. The channel switching circuit 310 is used to switch one of the input terminals to be connected to the output terminal according to a switching instruction, so that the signal bias circuit 320 receives the corresponding sensing signal of the tunnel magnetoresistance sensor 220; the signal amplification circuit 340 is sequentially connected to the filter circuit 330 and the signal bias circuit 320, and is used to amplify the sensing signal after being biased by the signal bias circuit 320 and filtered by the filter circuit 330, and generate a corresponding detection signal.

[0047] Specifically, in the signal processing circuit, each input end of the channel switching circuit 310 is connected to a tunnel magnetoresistance sensor 220 to receive the sensing signal generated by the tunnel magnetoresistance sensor 220, and the channel switching circuit 310 is switched so that one of the sensing signals is connected to the output end of the channel switching circuit 310, and the signal bias circuit 320 biases the received sensing signal to obtain a signal output that meets the requirements, and the filtering circuit 330 performs filtering processing and the signal circuit performs signal amplification to finally obtain a detection signal.

[0048] In one embodiment, the channel switching circuit 310 includes a multiplexer and a controller; the input end of the multiplexer is respectively connected to a tunnel magnetoresistive sensor 220, and the output end of the multiplexer is connected to the signal bias circuit 320; the control end of the multiplexer is connected to the controller to receive the control signal of the controller to switch the channel. Specifically, Figure 4 As shown, when the number of the tunnel magnetoresistive sensors 220 is 48, the multiplexer includes a 48-to-1 multiplexing chip D1, and the control end of the chip D1 is used to receive the control level of the controller, wherein the control levels A0, A1, A2, A3, A4 and A5 form different coded signals to switch to the corresponding channel through the coded signal. In one embodiment, the channel switching circuit 310 may also include multiple multiplexing chips, for example, multiple 8-to-1 multiplexing chips are connected in parallel and then cascaded through a multiplexing chip to complete the function of the 48-to-1 multiplexing chip D1.

[0049] In one embodiment, the signal bias circuit 320 includes a first operational amplifier chip, a first resistor, a second resistor and a third resistor; the in-phase input terminal of the first operational amplifier chip is connected to the output terminal of the channel switching circuit 310 and the first end of the first resistor; the inverting input terminal of the first operational amplifier chip is connected to the first end of the second resistor and the first end of the third resistor; the second end of the first resistor and the second end of the second resistor are connected to a power supply voltage, and the second end of the third resistor and the output terminal of the first operational amplifier chip are connected to the filter circuit 330. Specifically, as Figure 4 As shown, the first operational amplifier chip includes an operational amplifier chip U1, the first resistor includes a resistor R1, the second resistor includes a resistor R2, the third resistor includes a resistor R3, the second end of the resistor R1 is connected to the power supply voltage, the first end of the resistor R1 is connected to the in-phase input terminal of the operational amplifier chip U1, the second end of the resistor R2 is connected to the power supply voltage, and the first end of the resistor R2 is connected to the reverse input terminal of the operational amplifier chip U1.

[0050] Optionally, the filtering circuit 330 includes a first capacitor and a fourth resistor; the first end of the first capacitor is connected to the signal bias circuit 320, the second end of the first capacitor is connected to the first end of the fourth resistor and the signal amplification circuit 340, and the second end of the fourth resistor is grounded. Figure 3 As shown, the first capacitor includes capacitor C1, and the fourth resistor includes resistor R4. The output signal of the signal bias circuit 320 is filtered by forming a high-pass filter through capacitor C1 and resistor R4.

[0051] Optionally, the signal amplification circuit 340 includes a second operational amplifier chip, a fifth resistor and a sixth resistor; the in-phase input terminal of the second operational amplifier chip is connected to the filter circuit 330, the inverting input terminal of the second operational amplifier chip is connected to the first end of the fifth resistor and the first end of the sixth resistor, the second end of the fifth resistor is grounded, and the output terminal of the second operational amplifier chip is connected to the second end of the sixth resistor and is used to output the detection signal. Specifically, Figure 4 As shown, the second operational amplifier chip includes an operational amplifier chip U2, the fifth resistor includes a resistor R5, and the sixth resistor includes a resistor R6. The output signal of the filter circuit 330 is input to the in-phase input terminal of the operational amplifier chip U2, and is amplified by the operational amplifier chip U2 and then output.

[0052] Optional, such as Figure 5As shown, the probe body 100 includes: a first cavity 110 for accommodating the sensing signal generating unit 200, a second cavity 120 for accommodating the sensing signal processing unit 300, a first connecting portion 130 connecting the first cavity 110 and the second cavity 120, a second connecting portion 140 connecting the second cavity 120; and a first cable disposed in the first connecting portion 130 for realizing electrical connection between the signal processing circuit and the plurality of tunnel magnetoresistive sensors 220; and a second cable disposed in the second connecting portion 140 for realizing detection signal output of the signal processing circuit. Specifically, different cavities are provided on the probe body 100 to respectively accommodate the sensing signal generating unit 200 and the sensing signal processing unit 300. The cavities are connected by a first connection part 130, which includes but is not limited to a corrugated tube. The first cable passes through the first connection part 130 to form an electrical connection with the signal processing circuit and the tunnel magnetoresistive sensor 220 to transmit the sensing signal. The second connection part 140 can also be a corrugated tube. The second cable passes through the second connection part 140 to form an electrical connection with the signal processing circuit, and outputs the obtained detection signal at the second end. An aviation connector can be provided at the second end of the second cable to connect to an eddy current instrument to output the detection signal to the eddy current instrument for processing.

[0053] Optionally, the probe body 100 further includes: a first support structure 151 disposed at both ends of the first cavity 110 and / or a second support structure 152 disposed at both ends of the second cavity 120; when the first cavity 110 is located in the pipeline, the first support structure 151 forms a fixed positional relationship with the inner wall of the pipeline; when the second cavity 120 is located in the pipeline, the second support structure 152 forms a fixed positional relationship with the inner wall of the pipeline. Specifically, the first support structure 151 is disposed at both ends of the first cavity 110, and the first support structure 151 may be a petal structure, which is used to enable the probe body 100 to form a stable positional relationship with the inner wall of the pipeline inside the pipeline to ensure the accuracy of the test data. At the same time, the first support structure 151 makes the distance between the several tunnel magnetoresistive sensors 220 and the inner wall of the pipeline as equal as possible. Similarly, the second support structure 152 is disposed at both ends of the second cavity 120, and the second support structure 152 may be a petal structure, which is used to enable the probe body 100 to form a stable positional relationship with the inner wall of the pipeline inside the pipeline. The first supporting structure 151 and the second supporting structure 152 can both be made of ABS material.

[0054] Based on the present invention, a TMR die is used as a sensitive unit, and the die volume is only 0.5mm x 0.5mm x0.2mm. High-density array production can be performed to improve the spatial resolution of the probe and achieve high-resolution measurement in a narrow space. At the same time, the TMR is placed equidistantly, with an equal distance from the inner wall of the pipe. The array arrangement can directly obtain a three-dimensional image of the defect visualization magnetic field of the inner wall of the pipeline during scanning. TMR supports lower frequency measurement, so that the excited eddy currents are distributed at various positions of the pipeline. Combined with the advantage of TMR's small volume, it is beneficial to the detection of tiny defects on the inner and outer walls of the pipe. Compared with traditional sensors such as Bobbin coils or coil arrays that use extremely high frequencies for magnetic field measurement. TMR has better low-frequency characteristics, so it works better at low-frequency measurements. In a specific embodiment, the probe operating frequency is 1kHz to 100kHz, the excitation amplitude is 0V to 12V, and the output amplitude is 0V to 1V.

[0055] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. An internal penetration detection probe, characterized in that: include: A probe body for entering the interior of a pipeline, and an induction signal generating unit and an induction signal processing unit arranged on the probe body; The sensing signal generating unit includes a first PCB board and a plurality of tunnel magnetoresistive sensors arranged circumferentially along a preset circumference on the first PCB board, wherein the preset circumference is a circumference formed with the center of the cross section of the probe body as the center and a preset length as the radius; The sensing signal processing unit includes a second PCB board and a signal processing circuit arranged on the second PCB board; The signal processing circuit is electrically connected to the plurality of tunnel magnetoresistive sensors and is used for receiving the sensing signals generated by the tunnel magnetoresistive sensors and generating corresponding detection signals.

2. The internal penetration detection probe according to claim 1, characterized in that: The plurality of tunnel magnetoresistive sensors are arranged at equal intervals on the preset circumference.

3. The internal penetration detection probe according to claim 1, characterized in that: The tunnel magnetoresistive sensor is arranged on the first PCB board by gold wire bonding; The signal processing circuit is electrically connected to the tunnel magnetoresistive sensor via a gold wire corresponding to the tunnel magnetoresistive sensor.

4. The internal penetration detection probe according to claim 1, characterized in that: The signal processing circuit includes a channel switching circuit including a plurality of input terminals and an output terminal, as well as a signal bias circuit, a filtering circuit and a signal amplification circuit; Each input end of the channel switching circuit is respectively connected to a corresponding tunnel magnetoresistance sensor, and the output end of the channel switching circuit is connected to the signal bias circuit. The channel switching circuit is used to switch one of the input ends to be connected to the output end according to a switching instruction, so that the signal bias circuit receives the sensing signal of the corresponding tunnel magnetoresistance sensor; The signal amplifying circuit is connected to the filtering circuit and the signal biasing circuit in sequence, and is used to amplify the sensing signal after being biased by the signal biasing circuit and filtered by the filtering circuit, and generate a corresponding detection signal.

5. The internal penetration detection probe according to claim 4, characterized in that: The channel switching circuit includes a multiplexer and a controller; The input ends of the multiplexer are respectively connected to a corresponding tunnel magnetoresistive sensor, and the output end of the multiplexer is connected to the signal bias circuit; The control end of the multiplexer is connected to the controller and is used to receive a control signal from the controller to perform path switching.

6. The internal penetration detection probe according to claim 4, characterized in that: The signal bias circuit includes a first operational amplifier chip, a first resistor, a second resistor and a third resistor; The in-phase input terminal of the first operational amplifier chip is connected to the output terminal of the channel switching circuit and the first terminal of the first resistor; The inverting input terminal of the first operational amplifier chip is connected to the first end of the second resistor and the first end of the third resistor; The second end of the first resistor and the second end of the second resistor are connected to a power supply voltage, and the second end of the third resistor and the output end of the first operational amplifier chip are connected to the filter circuit.

7. The internal penetration detection probe according to claim 4, characterized in that: The filter circuit includes a first capacitor and a fourth resistor; A first end of the first capacitor is connected to the signal bias circuit, a second end of the first capacitor is connected to a first end of the fourth resistor and the signal amplification circuit, and a second end of the fourth resistor is grounded.

8. The internal penetration detection probe according to claim 4, characterized in that: The signal amplification circuit includes a second operational amplifier chip, a fifth resistor and a sixth resistor; The non-inverting input terminal of the second operational amplifier chip is connected to the filter circuit, the inverting input terminal of the second operational amplifier chip is connected to the first end of the fifth resistor and the first end of the sixth resistor, the second end of the fifth resistor is grounded, and the output terminal of the second operational amplifier chip is connected to the second end of the sixth resistor and is used to output the detection signal.

9. The internal penetration detection probe according to claim 1, characterized in that: The probe body comprises: a first cavity for accommodating the sensing signal generating unit, a second cavity for accommodating the sensing signal processing unit, a first connecting portion connecting the first cavity and the second cavity, and a second connecting portion connecting the second cavity; and A first cable disposed in the first connection portion for electrically connecting the signal processing circuit with the plurality of tunnel magnetoresistive sensors; A second cable is disposed in the second connection portion and is used to implement the detection signal output of the signal processing circuit.

10. The internal penetration detection probe according to claim 9, characterized in that: The probe body further comprises: a first supporting structure arranged at two ends of the first cavity and / or a second supporting structure arranged at two ends of the second cavity; When the first cavity is located in the pipe, the first support structure forms a fixed positional relationship with the inner wall of the pipe; When the second cavity is located in the pipe, the second supporting structure forms a fixed positional relationship with the inner wall of the pipe.

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