阅读说明：本技术 一种可变径涡流检测传感器设计方法及装置 (Method and device for designing variable-diameter eddy current detection sensor ) 是由 林俊明 王亚婷 李寒林 于 2020-12-15 设计创作，主要内容包括：本发明一种可变径涡流检测传感器设计方法及装置,用于金属管道(6)内部缺陷的无损检测,通过引线(11)连接于检测仪器(1),包括探头骨架(3)和阵列式检测传感器(2),其特征在于所述的探头骨架(3)设置为圆柱体结构,在探头骨架(3)的内部还设置有气囊(4),阵列式检测传感器(2)的检测线圈(21)通过可弯曲可延伸的柔性PCB板(22)围绕设置于探头骨架(3)的外围。实现能在管道的胀管部位,仍可很好地贴合管壁,不存在常规探头的间隙影响,较好地满足工业在役金属管道在役检测的灵敏度要求。(The invention discloses a method and a device for designing a variable-diameter eddy current detection sensor, which are used for nondestructive detection of internal defects of a metal pipeline (6), are connected to a detection instrument (1) through a lead (11), and comprise a probe framework (3) and an array detection sensor (2), and are characterized in that the probe framework (3) is arranged in a cylindrical structure, an air bag (4) is also arranged in the probe framework (3), and a detection coil (21) of the array detection sensor (2) is arranged on the periphery of the probe framework (3) in a surrounding manner through a bendable flexible extensible PCB (22). The pipe wall can be well attached to the pipe expansion part of the pipeline, the clearance influence of a conventional probe does not exist, and the sensitivity requirement of the in-service detection of the industrial in-service metal pipeline is well met.)

1. The utility model provides an eddy current testing sensor device of variable footpath for metal pipeline (6) internal defect's nondestructive test connects in detecting instrument (1) through lead wire (11), including probe skeleton (3) and array detection sensor (2), its characterized in that probe skeleton (3) set up to the cylinder structure, still be provided with gasbag (4) in the inside of probe skeleton (3), detection coil (21) of array detection sensor (2) are around setting up in the periphery of probe skeleton (3) through extensible flexible PCB board (22).

2. The eddy current inspection sensor device with variable diameter as claimed in claim 1, wherein the flexible PCB board (22) is a plurality of radial arrays of strip-shaped structures arranged on the periphery of the cylindrical probe frame (3).

3. The eddy current inspection sensor device with variable diameter as claimed in claim 1, wherein the flexible PCB board (22) is a plurality of strip-shaped structures axially arrayed on the periphery of the cylindrical probe frame (3).

4. The variable diameter eddy current testing sensor device according to claim 3, wherein the two ends of the flexible PCB plates (22) with the plurality of strip-shaped structures in the axial array are fixed on two head supports of the probe framework (3) with the cylindrical structure, and the probe framework (3) with the cylindrical structure is set to be a bendable structure.

5. The eddy current inspection sensor device with variable diameter as claimed in claim 1, wherein the air bag (4) is configured as a rubber cylinder or a sphere with any shape suitable for body type.

6. A variable diameter eddy current test sensor assembly as claimed in claim 1, wherein the bladder (4) is further provided with a gas pressure regulating device (5) to increase or decrease the inflation and deflation of the bladder (4) by gas tube (51).

7. A variable diameter eddy current testing method using the test sensor device of any one of claims 1 to 5, comprising the steps of:

a. detecting a coil lift-off value: starting instrument equipment, extending a detection sensor device of the calibrated detection instrument into the metal tube, and judging the lift-off state of the eddy current detection sensor through a lift-off excitation signal;

b. air pressure adjustment of the air bag: c, comparing the lift-off threshold value according to the lift-off state of the eddy current detection sensor judged in the step a, adjusting the air pressure of the air bag, repeating the step a to detect the lift-off value of the eddy current detection sensor, and adjusting the lift-off value to be within a set range value;

c. nondestructive testing of the metal tube: the eddy current detection sensor device which adjusts the air pressure of the air bag carries out mobile detection on the inner wall of the metal pipeline;

d. and (3) data screening and analyzing: and c, after the air pressure of the air bag in the step b is finally adjusted, analyzing the detection signal data of a plurality of eddy current detection sensor coils with similar lift-off values detected in the step a, and displaying the analysis result on an eddy current detection instrument.

8. The variable diameter eddy current testing method as claimed in claim 7, wherein in the data screening analysis in step d, when the eddy current testing signals with similar lift-off values are selected, when the pipeline is in a cone structure and the large diameter opening direction is extended to be tested, the series of eddy current testing signal data is selected to be the middle circle and the first half of the testing data to be analyzed.

9. The variable diameter eddy current testing method as claimed in claim 7, wherein in the data screening analysis in step d, when the eddy current testing signals with similar lift-off values are selected, and when the pipe is in a cone structure and the small diameter opening extends in the direction of the test, the series of eddy current testing signal data is selected to be the testing data of the middle circle and the latter half for analysis.

10. The variable diameter eddy current testing method according to claim 9, wherein in the case of a conical structure of the metal pipeline, when the small diameter opening is inserted for testing, the air bag is inflated after the eddy current testing sensor is inserted into the metal pipeline.

Technical Field

The invention relates to the technical field of nondestructive testing, in particular to a sensor technology of eddy current testing, and particularly relates to a method and a device for designing a variable-diameter eddy current testing sensor.

Background

In the industrial field, there are a large number of metal pipes. Various defects such as cracks, corrosion, thinning and the like can exist in the use process of the metal material. In-service testing is often required to prevent equipment failure. For example: condenser tubes for electric petrochemical systems also have tube expansion sections 61 (typically at the support plates and tube sheets) as shown in fig. 1 and 2, due to process design requirements.

Whereas conventionally used through-vortex probes (transducers) are typically designed with a minimum inner diameter. Therefore, the gap between the detection coil and the metal pipe wall is inevitably increased at the position of the tube expansion section 61, and the detection sensitivity is greatly reduced at the position due to the skin effect, so that the detection leakage caused by small defects is caused, and the leakage accident is caused.

Aiming at the problems of the defects, the invention adopts the following technical scheme to improve.

Disclosure of Invention

The invention aims to provide a method and a device for designing a variable-diameter eddy current detection sensor, and the technical scheme is as follows:

the utility model provides an eddy current testing sensor device of variable footpath for metal pipeline (6) internal defect's nondestructive test connects in detecting instrument (1) through lead wire (11), including probe skeleton (3) and array detection sensor (2), its characterized in that probe skeleton (3) set up to the cylinder structure, still be provided with gasbag (4) in the inside of probe skeleton (3), detection coil (21) of array detection sensor (2) are around setting up in the periphery of probe skeleton (3) through extensible flexible PCB board (22).

One of the conditions is that the flexible PCB (22) is a plurality of radial arrays of strip-shaped structures and is arranged on the periphery of the cylindrical probe framework (3), the best design condition is that the cylindrical probe framework (3) is radially arranged around a circle in the middle, then the flexible PCB (22) of the front part and the rear part are symmetrically arranged, when the diameter of a detected metal pipeline is large, the cylindrical probe framework (3) is widely opened, so that the array eddy current detection coils arranged in the middle of the cylinder in a circle are selected to carry out nondestructive detection on the metal pipe under the condition of a lift-off value suitable for an eddy current detection sensor. And the array eddy current coils on two adjacent flexible PCB boards (22) can be arranged in a staggered way to form a structure of a Chinese character 'pin'.

In another case, the flexible PCB (22) is a plurality of strip-shaped structures axially arrayed on the periphery of the cylindrical probe framework (3). The two ends of the flexible PCB plates (22) of the plurality of strip-shaped structures in the axial array are fixed on two head supports of the probe framework (3) in the cylindrical structure, and the probe framework (3) in the cylindrical structure is of a bendable structure. The array eddy current detection coils on the flexible PCB (22) are radially arranged around a circle in the right middle of the cylinder to divide the cylinder structure into a front part and a rear part, and the array eddy current detection coils on the front part and the rear part form a symmetrical arrangement structure. When the inner diameter of the detected metal pipeline is far larger than the diameter of the cylindrical probe framework (3), the cylindrical probe framework (3) is bent and unfolded so as to be suitable for the lifting value of the eddy current detection sensor, and the array type eddy current detection coils arranged in the middle circle of the cylinder are selected to carry out nondestructive detection on the metal pipeline.

The air bag (4) is of a rubber cylinder or a sphere and other structures with any shape suitable for body types.

The air bag (4) is also provided with an air pressure adjusting device (5), and the expansion and contraction of the air bag (4) are adjusted by increasing or decreasing air through an air pipe (51).

The invention also discloses a variable-diameter eddy current detection method, which uses the detection sensor device and comprises the following steps:

a. detecting a coil lift-off value: starting instrument equipment, extending a detection sensor device of the calibrated detection instrument into the metal tube, and judging the lift-off state of the eddy current detection sensor through a lift-off excitation signal;

b. air pressure adjustment of the air bag: c, comparing the lift-off threshold value according to the lift-off state of the eddy current detection sensor judged in the step a, adjusting the air pressure of the air bag, repeating the step a to detect the lift-off value of the eddy current detection sensor, and adjusting the lift-off value to be within a set range value;

c. nondestructive testing of the metal tube: the eddy current detection sensor device which adjusts the air pressure of the air bag carries out mobile detection on the inner wall of the metal pipeline;

d. and (3) data screening and analyzing: b, after the air pressure of the air bag in the step b is finally adjusted, analyzing the detection signal data of a plurality of eddy current detection sensor coils with similar lift-off values detected in the step a, and displaying the analysis result on an eddy current detection instrument;

in the data screening and analyzing in the step d, when the eddy current detection signals with similar lift-off values are selected, and when the pipeline is in a cone structure and the large-diameter opening direction stretches into the pipeline for detection, the eddy current detection signal data series are selected to be the first half detection data for analysis.

In the data screening analysis in the step d, when the eddy current detection signal with the similar lift-off value is selected, and when the pipeline is in a cone structure and extends into the small-diameter opening direction for detection, the selection of the eddy current detection signal data series is the detection data of the latter half for analysis.

Under the condition of the metal pipeline cone structure, when the small-diameter opening extends into the metal pipeline cone structure for detection, the air bag is inflated after the vortex detection sensor extends into the metal pipeline cone structure. Wherein the probe framework (3) is designed to be an elastically deformable structure with certain flexibility, but the flexibility is weaker than the flexibility of the flexible PCB (22).

According to the technical scheme, the invention has the following beneficial effects: .

The invention adopts array type eddy current detection coils, utilizes double rows (or more) of small coils arranged on a flexible extensible circuit board to form array detection capability, is divided into two sections (two circles) or more, are staggered with each other to form a structure in a shape like a Chinese character 'pin', and is internally supported by a cylindrical air bag, so that when the eddy current detection device works in a normal metal pipe section, the inner wall of the pipe can be better attached to the inner wall of the pipe than a conventional rigid body eddy current inner-penetrating type probe due to the elastic pressing effect of the air bag, and better detection sensitivity is achieved. Particularly, the pipe wall can be well attached to the pipe expansion part of the pipeline, the clearance influence of a conventional probe does not exist, and the sensitivity requirement of the in-service detection of the industrial in-service metal pipeline is well met;

when the detected metal pipeline is in a cone structure, the large-diameter opening direction stretches into the detection, the middle circle and the front half part of the eddy current detection sensor coil are selected to carry out nondestructive detection on the metal pipeline; when the detection sensor coil is inserted from the direction of the small-diameter opening for detection, the middle circle and the rear half eddy current detection sensor coil are selected for nondestructive detection of the metal pipeline, so that the detection sensor coil is more suitable for being attached to the pipe wall of the conical metal pipe;

when the axial array of the flexible extensible circuit board is arranged on the periphery of the cylindrical probe framework, the array eddy current detection coils are radially distributed around a circle in the middle of the cylinder to divide the cylinder structure into a front part and a rear part, the array eddy current detection coils on the front part and the rear part form a symmetrical arrangement structure, when the diameter of a detected metal pipeline is far larger than that of the cylinder structure probe framework, the frameworks on two sides are relatively close to each other, the cylinder probe framework is further outwards bent and unfolded, so that the array eddy current detection coils arranged in the middle of the cylinder in the circle are selected to perform nondestructive detection on the metal pipeline under the condition of being suitable for the lift-off value of the eddy current detection sensor, the fact that the same variable-diameter eddy current detection sensor device is suitable for inner wall detection of different metal pipelines is achieved.

Drawings

FIG. 1 is a schematic diagram illustrating a preferred embodiment of the present invention;

FIG. 2 is a schematic view of a cross-section of the inside of a metal pipeline in use in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic view of a radial arrangement of flexible circuit boards of a variable diameter eddy current test sensor assembly in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic view of the axial alignment of the flexible circuit board of the variable diameter eddy current test sensor assembly in accordance with the preferred embodiment of the present invention;

FIG. 5 is a schematic view of a balloon of the preferred embodiment of the present invention in a cylindrical configuration;

FIG. 6 is a schematic view of a balloon of the preferred embodiment of the present invention in a spherical configuration;

FIG. 7 is a schematic view of the preferred embodiment of the present invention showing the smaller expansion of the bladder when the flexible circuit boards are axially aligned;

FIG. 8 is a schematic diagram of the preferred embodiment of the present invention showing the bladder expanding more when the flexible circuit board is axially aligned and the flexible circuit board bending;

FIG. 9 is a schematic view showing the use state of the flexible printed circuit board in bending with the air bag expanded greatly when the flexible printed circuit board is arranged axially according to the preferred embodiment of the present invention;

FIG. 10 is a schematic flow chart of a method in accordance with a preferred embodiment of the present invention;

FIG. 11 is a schematic illustration of a large diameter run-in test of a tapered metal pipe in accordance with a preferred embodiment of the present invention;

FIG. 12 is a schematic view of the small diameter penetration test of the tapered metal pipe according to the preferred embodiment of the present invention.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

As shown in fig. 1 to 9, a diameter-variable eddy current testing sensor device for nondestructive testing of internal defects of a metal pipeline 6 is connected to a testing instrument 1 through a lead 11, and includes a probe skeleton 3 and an array type testing sensor 2, the probe skeleton 3 is set to be a cylindrical structure, an air bag 4 is further arranged inside the probe skeleton 3, and a detection coil 21 of the array type testing sensor 2 is surrounded on the periphery of the probe skeleton 3 through a flexible PCB 22 which can be extended in a bending manner.

As shown in fig. 3, in one of the cases, the flexible PCB 22 is a plurality of radial arrays of strip-shaped structures and is disposed on the periphery of the cylindrical probe framework 3, the best design case is that the flexible PCB 22 is radially arranged around a circle in the middle of the cylindrical probe framework 3, then the flexible PCB 22 is symmetrically arranged in the front and rear portions, when the diameter of the detected metal pipeline is large, the cylindrical probe framework 3 is widely spread, so that the array eddy current detection coils arranged in the middle circle in the middle of the cylinder are selected to perform nondestructive detection on the metal pipe under the condition of being suitable for the lift-off value of the eddy current detection sensor. And the array eddy current coils on two adjacent flexible PCB boards 22 can be arranged in a mutually staggered manner to form a structure in the shape of a Chinese character 'pin', so as to avoid the existence of a detection blind area.

As shown in fig. 4, in another case, the flexible PCB 22 is a plurality of strip-shaped structures axially arrayed on the periphery of the cylindrical probe skeleton 3. The two ends of the flexible PCB plates 22 with the plurality of strip-shaped structures in the axial array are fixed on the two head supports of the probe framework 3 with the cylindrical structure, and the probe framework 3 with the cylindrical structure is of a bendable structure. The array eddy current detection coils on the flexible PCB 22 are arranged around a circle in the radial direction in the right middle of the cylinder to divide the cylinder structure into a front part and a rear part, and the front part and the rear part of the array eddy current detection coils form a symmetrical arrangement structure. In the use state shown in fig. 9, when the diameter of the detected metal pipeline is much larger than that of the cylindrical probe skeleton 3, the cylindrical probe skeleton 3 is bent and spread to be suitable for the lift-off value of the eddy current detection sensor, and the array type eddy current detection coil arranged in the middle circle of the cylinder is selected to perform nondestructive detection on the metal pipe.

As shown in fig. 5 and 6, the airbag 4 is configured in any shape suitable for body type, such as a rubber cylinder or a sphere.

The air bag 4 is further provided with an air pressure adjusting device 5 for adjusting the expansion and contraction of the air bag 4 by increasing or decreasing air through the air tube 51.

As shown in fig. 10, the invention further discloses a variable diameter eddy current testing method, which uses the above testing sensor device and has the following steps:

a. detecting a coil lift-off value: starting instrument equipment, extending a detection sensor device of the calibrated detection instrument into the metal tube, and judging the lift-off state of the eddy current detection sensor through a lift-off excitation signal;

b. air pressure adjustment of the air bag: c, comparing the lift-off threshold value according to the lift-off state of the eddy current detection sensor judged in the step a, adjusting the air pressure of the air bag, repeating the step a to detect the lift-off value of the eddy current detection sensor, and adjusting the lift-off value to be within a set range value;

c. nondestructive testing of the metal tube: the eddy current detection sensor device which adjusts the air pressure of the air bag carries out mobile detection on the inner wall of the metal pipeline;

d. and (3) data screening and analyzing: b, after the air pressure of the air bag in the step b is finally adjusted, analyzing the detection signal data of a plurality of eddy current detection sensor coils with similar lift-off values detected in the step a, and displaying the analysis result on an eddy current detection instrument;

as shown in fig. 11, in the data screening analysis in step d, when the eddy current detection signals with similar lift-off values are selected, and when the pipeline is in a conical structure and the large-diameter opening extends into the pipeline for detection, the eddy current detection signal data series are selected as the first half detection data for analysis.

As shown in fig. 12, in the data screening analysis in step d, when the eddy current test signal with a similar lift-off value is selected, and when the pipe is in a conical structure and the pipe is inserted in the small diameter opening direction for testing, the eddy current test signal data series is selected as the test data of the latter half for analysis.

Under the condition of the metal pipeline cone structure, when the small-diameter opening extends into the metal pipeline cone structure for detection, the air bag is inflated after the vortex detection sensor extends into the metal pipeline cone structure. Wherein the probe skeleton 3 is designed as an elastically deformable structure having a certain flexibility, but the flexibility should be weaker than the softness of the flexible PCB 22.

The above is one embodiment of the present invention. Furthermore, it is to be understood that all equivalent or simple changes in the structure, features and principles described in the present patent concepts are included in the scope of the present patent.