Pipeline detection probe

Abstract

The invention discloses a pipeline detection probe which comprises a supporting pipe, a metal sleeve, a TMR magnetoresistive sensor, a coil assembly, a signal processing circuit board and a pouring sealant. The open end of the metal sleeve is in butt joint with the supporting pipe. The TMR magnetoresistive sensor and the signal processing circuit board are arranged in the metal sleeve in the axial direction of the metal sleeve, and the coil assemblies are symmetrically distributed on the two opposite sides of the TMR magnetoresistive sensor. The pouring sealant is filled in the metal sleeve, and the TMR magnetoresistive sensor, the coil assembly and the signal processing circuit board are positioned and sealed in the metal sleeve; a wire of the signal processing circuit board is externally connected through the supporting pipe. The metal sleeve is used as an end shell of the probe, so that the anti-collision and anti-pollution capabilities of the probe are improved; the TMR magnetoresistive sensor with the TMR arranged in the annular shape is matched with the coil assemblies symmetrically distributed on the two sides, the sensitivity of the sensor in the low-frequency band is improved, the loss of eddy current in the metal sleeve is reduced, and the problem of signal attenuation caused by the metal sleeve is solved.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing, and in particular to a pipeline detection probe. Background Art

[0002] Nuclear fuel cladding, evaporator heat transfer tubes and other nuclear-grade thin-walled tubes are the pressure boundaries of nuclear power plants. The safety and reliability of these structures are crucial to maintaining nuclear power safety. Electromagnetic eddy current testing is the most widely used nuclear power thin-walled tube testing technology. However, due to the working principle of the induction coil, the existing eddy current array probe is difficult to improve the sensitivity and spatial resolution at the same time, and the detection ability of tiny defects is insufficient, which cannot meet the needs of nuclear power testing. Therefore, it is urgent to study new detection methods or probe structures to serve the rapid and safe development of nuclear power.

[0003] Since the inner wall of the evaporator heat transfer tube is often corroded and precipitated, which may affect the detection of the probe, the commonly used detection probe adopts a plastic shell, which has poor anti-collision and anti-fouling capabilities. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an improved pipeline detection probe.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a pipeline detection probe, including a support tube, a metal sleeve with one end closed, a plurality of TMR magnetoresistive sensors arranged in a TMR ring, a coil assembly, a signal processing circuit board and a potting glue;

[0006] The metal sleeve is butted with the support tube at an open end; the TMR magnetoresistance sensor and the signal processing circuit board are arranged along the axial direction of the metal sleeve, and the coil assembly is symmetrically distributed on opposite sides of the TMR magnetoresistance sensor; the TMR magnetoresistance sensor and the coil assembly are electrically connected to the signal processing circuit board respectively;

[0007] The potting glue is filled in the metal sleeve, and the TMR magnetoresistive sensor, coil assembly and signal processing circuit board are positioned and sealed in the metal sleeve; the wires of the signal processing circuit board are externally connected through the support tube.

[0008] In some embodiments, the TMR magnetoresistive sensor includes a sensor circuit board and a plurality of the TMRs; the plurality of the TMRs are disposed on a surface of the sensor circuit board and are arranged in a ring to form a ring array.

[0009] In some embodiments, the TMRs are at least eight.

[0010] In some embodiments, inside the metal sleeve, the TMR magnetoresistive sensor faces the closed end of the metal sleeve with a side provided with the TMR, and the signal processing circuit board is arranged perpendicular to the surface of the TMR magnetoresistive sensor on a side of the TMR magnetoresistive sensor facing the open end of the metal sleeve.

[0011] In some embodiments, the coil assembly includes a first skeleton and a second skeleton arranged on opposite sides of the TMR magnetoresistive sensor, and a first excitation coil and a second excitation coil respectively wrapped around the first skeleton and the second skeleton; the first excitation coil and the second excitation coil are symmetrically distributed on opposite sides of the TMR magnetoresistive sensor.

[0012] In some embodiments, the TMR magnetoresistive sensor is connected to the signal processing circuit board via an FPC cable.

[0013] In some embodiments, the open end of the metal sleeve is connected to one end of the support tube by laser welding or underwater welding.

[0014] In some embodiments, the support tube is a corrugated tube; and the metal sleeve is a stainless steel sleeve.

[0015] In some embodiments, the potting glue is AB glue or three-proof glue.

[0016] In some embodiments, the metal sleeve is a circular tube, and the outer circumference of the TMR magnetoresistive sensor is circular.

[0017] The beneficial effects of the present invention are as follows: the metal sleeve is used as the end shell of the probe to improve the anti-collision and anti-fouling capabilities of the probe; the TMR magnetoresistive sensor arranged in a ring shape is matched with the coil components symmetrically distributed on both sides to improve the sensitivity of the sensor in the low frequency band, reduce the loss of eddy current in the metal sleeve, and solve the problem of signal attenuation caused by the metal sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0019] Figure 1 It is a schematic diagram of the structure of a pipeline detection probe according to an embodiment of the present invention;

[0020] Figure 2 is a disassembled diagram of a pipeline detection probe according to an embodiment of the present invention;

[0021] Figure 3 This is a disassembled diagram of a metal sleeve portion of a pipeline detection probe according to an embodiment of the present invention;

[0022] Figure 4is a C-scan magnetic field image obtained after a pipeline detection probe according to an embodiment of the present invention scans a pipeline;

[0023] Figure 5 It is a C-scan magnetic field image obtained by scanning the pipeline with a pipeline detection probe with a high-strength plastic casing. DETAILED DESCRIPTION

[0024] 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.

[0025] The pipeline detection probe of the present invention is suitable for pipeline detection of heat transfer pipes of steam generators in nuclear power plants.

[0026] like Figure 1-Figure 3 As shown, a pipeline detection probe according to an embodiment of the present invention may include a support pipe 10, a metal sleeve 20, a TMR magnetoresistive sensor 30, a coil assembly 40, and a signal processing circuit board 50.

[0027] The metal sleeve 20 is a tube body with one end closed and the other end open, and the metal sleeve 20 and the support tube 10 are butted together in the axial direction to form the overall housing of the probe. The metal sleeve 20 serves as the probe end housing of the probe, and the TMR magnetoresistive sensor 30, the coil assembly 40 and the signal processing circuit board 50 are all accommodated in the metal sleeve 20. The metal sleeve 20 is also filled with potting glue to position and seal the TMR magnetoresistive sensor 30, the coil assembly 40 and the signal processing circuit board 50.

[0028] Specifically, the support tube 10 is a metal tube with certain structural strength. The support tube 10 is further preferably a corrugated tube, which has certain expansion and contraction capabilities and can bend and recover to meet the requirements of traveling in the pipeline. The corrugated tube is a stainless steel corrugated tube.

[0029] The metal sleeve 20 is connected to the support tube 10 at an open end. Since both the support tube 10 and the metal sleeve 20 are made of metal materials, the two can be fixedly connected by welding (such as laser welding) or underwater welding.

[0030] The metal sleeve 20 is further preferably a stainless steel tube, which has sufficient structural strength and corrosion resistance and is suitable for the detection environment of pipelines such as heat transfer tubes.

[0031] The TMR magnetoresistance sensor 30 and the signal processing circuit board 50 are arranged in the metal sleeve 20 along the axial direction. In the metal sleeve 20, the TMR magnetoresistance sensor 30 is close to the closed end of the metal sleeve 20, and the signal processing circuit board 50 is close to the open end of the metal sleeve 20. In addition, the TMR magnetoresistance sensor 30 is connected to the signal processing circuit board 50 through an FPC cable, so that the output signal of the TMR magnetoresistance sensor 30 is transmitted to the signal processing circuit board 50 through the FPC cable.

[0032] The TMR magnetoresistive sensor 30 may further include a sensor circuit board 31 and a plurality of TMRs (tunnel magnetoresistance) 32. The plurality of TMRs 32 are disposed on a surface of the sensor circuit board 31 and are arranged in a ring array on the surface. To ensure that the detection result has sufficient resolution, the number of TMRs 32 is at least eight.

[0033] The peripheral shape of the sensor circuit board 31 determines the peripheral shape of the TMR magnetoresistive sensor 30, and the peripheral shape of the TMR magnetoresistive sensor 30 is preferably set corresponding to the metal sleeve 20. For example, when the metal sleeve 20 is a circular tube, the peripheral shape of the TMR magnetoresistive sensor 30 is set to a circular shape.

[0034] The signal processing circuit board 50 is a polygonal structure as a whole, such as a rectangular structure, and the overall peripheral shape of the signal processing circuit board 50 is determined by the substrate of the signal processing circuit board 50 .

[0035] In the metal sleeve 20, the signal processing circuit board 50 is arranged with its length direction parallel to the axial direction of the metal sleeve 20, and the TMR magnetoresistive sensor 30 faces the closed end of the metal sleeve 20 with the side provided with the TMR 32, so that the signal processing circuit board 50 and the surface of the TMR magnetoresistive sensor 30 are perpendicular to each other, and the signal processing circuit board 50 is located on the side of the TMR magnetoresistive sensor 30 facing the open end of the metal sleeve 20.

[0036] The coil assembly 40 is symmetrically distributed on two opposite sides of the TMR magnetoresistive sensor 30 . The coil assembly 40 is electrically connected to the signal processing circuit board 50 and is used to generate a magnetic field signal through an external power supply of the signal processing circuit board 50 .

[0037] Furthermore, the coil assembly 40 includes a first skeleton 41 and a second skeleton 42 arranged on opposite sides of the TMR magnetoresistance sensor 30, and a first excitation coil (not shown) and a second excitation coil (not shown) respectively wrapped around the first skeleton 41 and the second skeleton 42; the first excitation coil and the second excitation coil are symmetrically distributed on opposite sides of the TMR magnetoresistance sensor 30, and are used to generate a magnetic field after power is supplied, and the TMR magnetoresistance sensor 30 is in the magnetic field.

[0038] Corresponding to the circular metal sleeve 20 and the circular TMR magnetoresistive sensor 30 , the first skeleton 41 and the second skeleton 42 are cylindrical structures, the first excitation coil is wound around the first skeleton 41 along the circumference thereof, and the second excitation coil is wound around the second skeleton 42 along the circumference thereof.

[0039] The two symmetrically arranged excitation coils reduce the background magnetic field, and the large current (1A in an ideal state) increases the sensitivity of the sensor, which increases the magnetic field. The two work together to improve the sensitivity when the sensor magnetic field is not saturated.

[0040] The pipeline detection probe also includes a potting glue (not shown). The potting glue is filled in the metal casing 20, and the TMR magnetoresistive sensor 30, the coil assembly 40 and the signal processing circuit board 50 are positioned and sealed in the metal casing 20 to prevent water and dirt. The wires of the signal processing circuit board 50 are connected to the external output interface (such as an aviation interface) through the support tube 10 to achieve external connection.

[0041] The potting glue can be AB glue or three-proof glue, etc.

[0042] In one embodiment, when laser welding is used to weld the metal sleeve 20 and the support tube 10, in order to avoid problems such as melting of the potting glue due to the high temperature of laser welding, the metal sleeve 20 is preferably potted with a three-proof glue. In another embodiment, when underwater welding is used to connect the metal sleeve 20 and the support tube 10, the metal sleeve 20 can be potted with AB glue or a three-proof glue.

[0043] When assembling the pipeline detection probe of the present invention, the TMR magnetoresistive sensor 30, the coil assembly 40 and the signal processing circuit board 50 are first assembled into the metal sleeve 20, and then sealed with potting glue, and finally the metal sleeve 20 and the support tube 10 are welded and connected to form a whole.

[0044] When the pipeline detection probe of one embodiment of the present invention is used, the TMR magnetoresistive sensor 30 is adapted to a ±5V to ±12V wide power supply, and the output interface of the wire external connection of the signal processing circuit board 50 is a 16-pin aviation interface. The operating frequency is 50kHz, the excitation amplitude is 12V, and the output amplitude is 0V to 1V.

[0045] Taking the scanning of the inner and outer walls of a pipeline as an example, the C-scan magnetic field image obtained by scanning is as follows: Figure 4 As shown, by adjusting the excitation amplitude and frequency, pipeline defects can be well detected.

[0046] A pipeline detection probe using a high-strength plastic sleeve as the probe end housing is used as a comparative example. Under the same scanning conditions, the C-scan magnetic field image obtained by the comparative example is shown in the figure below. Figure 5 shown.

[0047] from Figure 4 and Figure 5 By comparison, it can be seen that compared with the high-strength plastic casing, the detection results of the same pipeline using the metal casing as the probe end shell are similar, which shows that the pipeline detection probe of the present invention solves the signal attenuation problem caused by the metal casing and still has a good detection effect on 10% to 70% wall thickness thinning type defects.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A pipeline detection probe, characterized in that: It includes a support tube, a metal sleeve with one end closed, a plurality of TMR magnetoresistive sensors arranged in a TMR ring, a coil assembly, a signal processing circuit board and a potting glue; The metal sleeve is butted with the support tube at an open end; the TMR magnetoresistance sensor and the signal processing circuit board are arranged along the axial direction of the metal sleeve, and the coil assembly is symmetrically distributed on opposite sides of the TMR magnetoresistance sensor; the TMR magnetoresistance sensor and the coil assembly are electrically connected to the signal processing circuit board respectively; The potting glue is filled in the metal sleeve, and the TMR magnetoresistive sensor, coil assembly and signal processing circuit board are positioned and sealed in the metal sleeve; the wires of the signal processing circuit board are externally connected through the support tube.

2. The pipeline detection probe according to claim 1, characterized in that: The TMR magnetoresistive sensor includes a sensor circuit board and a plurality of TMRs; the plurality of TMRs are disposed on a surface of the sensor circuit board and are arranged in a ring to form a ring array.

3. The pipeline detection probe according to claim 2, characterized in that: The number of the TMRs is at least eight.

4. The pipeline detection probe according to claim 2, characterized in that: In the metal sleeve, the TMR magnetoresistive sensor faces the closed end of the metal sleeve with a side provided with the TMR, and the signal processing circuit board is arranged perpendicular to the surface of the TMR magnetoresistive sensor on a side of the TMR magnetoresistive sensor facing the open end of the metal sleeve.

5. The pipeline detection probe according to claim 1, characterized in that: The coil assembly includes a first frame and a second frame arranged on opposite sides of the TMR magnetoresistive sensor, and a first excitation coil and a second excitation coil respectively wrapped around the first frame and the second frame; the first excitation coil and the second excitation coil are symmetrically distributed on opposite sides of the TMR magnetoresistive sensor.

6. The pipeline detection probe according to any one of claims 1 to 5, characterized in that: The TMR magnetoresistive sensor is connected to the signal processing circuit board via an FPC cable.

7. The pipeline detection probe according to any one of claims 1 to 5, characterized in that: The open end of the metal sleeve is connected to one end of the support pipe by laser welding or underwater welding.

8. The pipeline detection probe according to any one of claims 1 to 5, characterized in that: The support tube is a corrugated tube; the metal sleeve is a stainless steel sleeve.

9. The pipeline detection probe according to any one of claims 1 to 5, characterized in that: The potting glue is AB glue or three-proof glue.

10. The pipeline detection probe according to any one of claims 1 to 5, characterized in that: The metal sleeve is a circular tube, and the outer periphery of the TMR magnetoresistive sensor is circular.

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