A detection device for internal pipeline corrosion detection

Abstract

The application relates to the technical field of electromagnetic nondestructive testing, in particular to a detection device for inner-wearing pipeline corrosion detection, which comprises an array probe, a host, a DA digital-analog converter, a power amplification circuit, a current AD analog-digital converter, an AD analog-digital converter one, an AD analog-digital converter two, an AD analog-digital converter three, an AD analog-digital converter four and a sampling resistor, the outer portion of the array probe is provided with a detected metal pipeline, the array probe is inserted into the detected metal pipeline, and the pipeline wall corrosion is continuously scanned and detected from the inside of the detected metal pipeline. The detection device for inner-wearing pipeline corrosion detection can make the array probe perform small-amplitude accurate adjustment of the position, is convenient for accurate adjustment, and can adjust the array probe detection range and detection height through the setting of the adjusting device, and the adjustability is high.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic nondestructive testing technology, and in particular to a detection device for internal pipeline corrosion detection. Background Technology

[0002] In industrial sites with high safety requirements, such as those in the petroleum, chemical, natural gas, and nuclear power industries, the need for corrosion detection of metal pipelines and tanks is extremely urgent. Currently, the main non-destructive testing methods for pipelines include ultrasonic testing, magnetic flux leakage testing, and pulsed eddy current testing. Pulsed eddy current testing is an electromagnetic non-destructive testing method that can detect wall corrosion of ferromagnetic components at relatively large coil probe lift-off distances. It uses pulsed current instead of sinusoidal current excitation to induce a transient eddy current field within the conductor. The degree of wall corrosion is assessed by comparing the attenuation changes of the time-domain signal at two detection points.

[0003] However, in actual testing, when the inspected metal pipe is tens of meters long, the detection efficiency of pulsed eddy current scanning is low, and it is inconvenient to move the probe inside the pipe for inspection. Therefore, it is necessary to design an internal pipe corrosion detection device that can be easily moved inside the pipe for inspection and can be easily moved for inspection with small amplitude and precision, and the probe can be adjusted in place, thereby improving the detection efficiency of pipe corrosion scanning. Summary of the Invention

[0004] The main objective of this invention is to overcome the problem that existing detection probes are inconvenient to move inside pipes for detection, and to provide an internal pipe corrosion detection device. This device features an array probe with small-amplitude, precise position adjustments for easy and accurate adjustment, and the array probe's detection range and height are also adjustable, offering high adjustability.

[0005] The technical solution adopted by the present invention to achieve its technical objective is: a detection device for internal pipe corrosion detection, including an array probe, the array probe being mounted on a moving device, the moving device including a fixed plate, a roller being provided below the fixed plate, the roller being rotatably connected to a rod, and the moving device further including a pull bar for pulling the roller to rotate.

[0006] The array probe is mounted on an adjustment device, which includes a liftable movable plate; one end of the array probe is rotatably mounted on the movable plate, and the other end is fixed to a bending plate.

[0007] Preferably, a plurality of the rollers are connected to each other in a ring and sleeved on the rod body, wherein a group of the rollers is fixedly mounted on a fixed plate, and a first telescopic rod is connected to the rod body.

[0008] Preferably, a tie rod is provided between the fixed plate and the roller.

[0009] Preferably, a first sliding plate is fixedly installed on the horizontal section of the bending plate, and a second sliding plate is fixedly installed on one side of the first sliding plate; a first slider is slidably connected inside the first sliding plate, a rotating shaft is installed inside the first slider, a movable plate is movably connected to the rotating shaft, a second slider is movably connected to one end of the movable plate, one end of the movable plate is movably sleeved on the rotating shaft, and the other end is rotatably connected to the inside of the second slider, a pad is fixedly installed inside the second slider, and a movable plate is fixedly installed at one end of the pad.

[0010] Preferably, one end of the array probe is hinged, and the hinge is fixed to the movable plate by a pin, allowing the two array probes to move freely around the hinge.

[0011] The other end of the two array probes is connected to a bearing via a column. The bearing is fitted onto the column, and a barb is hinged to one side of the bearing. A positioning post is provided on one side of the barb and the positioning post is fixedly installed on the vertical plate of the bending plate.

[0012] The two sets of barbed rods are connected by a spring.

[0013] Preferably, the array probe consists of four sets of single-channel coils, each set of coils including a detection coil and an excitation coil connected to the detection coil;

[0014] The outermost layer of the coil is fixedly encapsulated by the array probe shell.

[0015] Preferably, a second telescopic rod is fixedly installed at one end of the horizontal plate portion of the bent plate, and the telescopic end of the second telescopic rod is fixedly connected to the rotating shaft.

[0016] Preferably, the array probe is controlled by a control system, which includes an AD analog-to-digital converter for receiving signals from the array probe, a host computer for processing the signals from the AD analog-to-digital converter, a DA digital-to-analog converter communicatively connected to the host computer, a power amplifier circuit connected to the DA digital-to-analog converter, a sampling resistor communicatively connected to the power amplifier circuit, and an AD analog-to-digital converter communicatively connected to the sampling resistor.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] (1) Extending the single-probe mode to a multi-channel array probe mode can improve the efficiency of pipeline internal corrosion scanning. The main function of the multi-channel array pulsed eddy current corrosion scanning hardware system is to generate an excitation field, realize the scanning control of the object under test and the synchronous acquisition of the signals sensed by the probe detection unit, and finally complete the display of the imaging results. The multi-channel pulsed eddy current hardware system with synchronous excitation and acquisition can excite all probes in multiple channels at the same time and realize the synchronous acquisition of multiple signals. When scanning with a single probe, multiple scans are required to obtain complete information of the corrosion area. However, after scanning the corrosion area once with a multi-channel array probe, the wall thickness information of the entire local area can be obtained, thereby improving the scanning efficiency and shortening the detection time.

[0019] (2) A multi-channel pulsed eddy current detection array probe can be used to image and detect corrosion areas, improving the spatial resolution of corrosion detection. When scanning with a single probe, only the remaining wall thickness information of one point can be obtained in one scan. However, when a multi-channel probe scans the area under inspection, each probe generates an induced voltage, and the data from each probe contains partial information about the corrosion area. By performing data fusion processing on the detection signals from each channel, imaging detection of corrosion defects can be achieved. It can effectively identify the edge of the corrosion area, the maximum corrosion depth and its location, thereby improving the detection resolution of corrosion defects.

[0020] (3) The remaining wall thickness of each channel is detected by extracting the characteristic quantity of the induced voltage signal. The signal processing is simple and fast, which can ensure the efficiency and speed of continuous pulse eddy current scanning. The time domain signal of the induced voltage detected by pulse eddy current in each channel is plotted in a semi-logarithmic coordinate system. The slope of the straight line segment of the detection signal is extracted as the detection characteristic quantity to obtain the relative change of the wall thickness of the inspected metal pipe. The straight line segment of the detection signal in the semi-logarithmic coordinate system has obvious characteristics and is easy to judge. The extraction of the characteristic quantity is easy to operate. The extraction process only requires simple straight line fitting of the signal curve. The signal processing speed is fast, which can speed up the detection speed of pulse eddy current array scanning for steel pipe corrosion. Moreover, the detection result of the relative change of steel pipe wall thickness is not affected by the lifting of the probe coil, thereby improving the reliability of the method in field application.

[0021] (4) By setting the moving device, the position of the array probe can be adjusted slightly and precisely, which is convenient for precise adjustment; by setting the adjusting device, the detection range and detection height of the array probe can be adjusted. Attached Figure Description

[0022] Figure 1 This is a structural diagram of a pipeline undergoing internal pulsed eddy current testing.

[0023] Figure 2This is a top view of the array probe structure.

[0024] Figure 3 This is a schematic diagram of the cross-sectional structure of the array probe.

[0025] Figure 4 This is a curve showing the extraction of feature quantities of a straight line segment of the induced voltage detection signal for a single channel in an array probe.

[0026] Figure 5 This is a curve showing the extraction of characteristic quantities of the induced voltage detection signal from multiple channels synchronously acquired in the array probe.

[0027] Figure 6 This is a schematic diagram of the front cross-sectional structure of the array probe and the moving device.

[0028] Figure 7 This is a side view schematic diagram of the array probe and the moving device.

[0029] Figure 8 This is a three-dimensional structural diagram of the adjustment device.

[0030] Figure 9 This is a schematic diagram of the main structure of the adjustment device.

[0031] Figure 10 This is a top view of the structure of two sets of array probes, a fixing plate, and an adjustment device.

[0032] The components are as follows: 10. Array probe; 11. Excitation coil; 12. Detection coil; 13. Array probe housing; 20. Main unit; 21. DA digital-to-analog converter; 22. Power amplifier circuit; 23. AD analog-to-digital converter; 24. AD analog-to-digital converter one; 25. AD analog-to-digital converter two; 26. AD analog-to-digital converter three; 27. AD analog-to-digital converter four; 28. Sampling resistor; 30. Metal pipe under inspection; 40. Fixing plate; 41. Pull bar; 42. Roller; 43. Rod; 44. Connecting plate; 45. First telescopic rod; 50. Bending plate; 51. First sliding plate; 52. Second sliding plate; 53. First slider; 54. Rotating shaft; 55. Moving plate; 56. Second slider; 57. Second telescopic rod; 58. Pad plate; 59. Movable plate; 510. Bearing; 511. Spring; 512. Positioning post; 513. Barrel hook rod. Detailed Implementation

[0033] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0036] Example 1:

[0037] Please see Figure 1-3 An internal pipe corrosion detection device includes an array probe 10, with a metal pipe 30 to be inspected (commonly carbon steel pipe) disposed outside the array probe 10. The array probe 10 consists of four sets of single-channel coils, each set including a detection coil 12 and an excitation coil 11; the detection coil 11 is located outside the excitation coil 12, or vice versa, and the outermost layer is fixedly encapsulated by an array probe housing 13.

[0038] The array probe 10 extends into the inspected metal pipe 30 to continuously scan and detect corrosion on the pipe wall from inside the inspected metal pipe 30. When the array probe 10 is used for continuous scanning, it simultaneously acquires time-domain signals of multiple channel induced voltages and sends them to the host 20 for storage. The host 20 can realize functions such as synchronous acquisition, processing, result display, and data storage of multiple signals. It processes the received discrete signal data to obtain the remaining wall thickness information and probe position information of the inspected metal pipe 30.

[0039] It also includes a host 20, a DA digital-to-analog converter 21, a power amplifier circuit 22, an AD analog-to-digital converter 23, an AD analog-to-digital converter I 24, an AD analog-to-digital converter II 25, an AD analog-to-digital converter III 26, an AD analog-to-digital converter IV 27, and a sampling resistor 28; the two ends of the four sets of excitation coils 11 are respectively connected to the AD analog-to-digital converter I 24, the AD analog-to-digital converter II 25, the AD analog-to-digital converter III 26, and the AD analog-to-digital converter IV 27, and the AD analog-to-digital converter 24 is connected to the host 20; the host 20 is also connected to the DA digital-to-analog converter 21 and the AD analog-to-digital converter 23; the DA digital-to-analog converter 21 is connected to the input of the power amplifier circuit 22, and the output of the power amplifier circuit 22 is connected to the sampling resistor 28 and then connected to the detection coil 11; the sampling resistor 28 is also connected to the AD analog-to-digital converter 23.

[0040] The DA digital-to-analog converter 21 is used to convert the excitation digital signal output by the computer into an analog signal; the power amplifier circuit 22 is used to amplify the signal; the AD analog-to-digital converter 23 is a current AD analog-to-digital converter; AD analog-to-digital converter one 24, AD analog-to-digital converter two 25, AD analog-to-digital converter three 26 and AD analog-to-digital converter four 27 are used to synchronously acquire the time-domain signal of the induced voltage across the detection coil 12 of multiple channels in the array probe 10; the sampling resistor 28 is a sampling resistor used for current sampling.

[0041] Example 2:

[0042] Please see Figure 1-5 Based on the above embodiments, the calculation and implementation methods of the detection device for internal pipe corrosion detection are as follows:

[0043] Step 1: Synchronous acquisition of multi-channel induced voltage signals (SSA) from the pulsed eddy current array probe.

[0044] The synchronous acquisition of the induced voltage time-domain signal using the aforementioned multi-channel pulsed eddy current detection system is called the signal acquisition step, Synchronous Signal Acquisition (SSA), as follows:

[0045] Step SSA-1: Connect all four excitation coils 1 in the array probe 10 in series and then connect them to the output of the power amplifier circuit; then connect the two ends of the four detection coils in the array probe 10 to the input terminals of four independent AD analog-to-digital converters one to four respectively.

[0046] Step SSA-2: Place the array probe 10 vertically along the radial direction of the pipe inside the inspected metal pipe 30. The lifting distance between the lower edge of the array probe 10 and the inner surface of the inspected metal pipe 30 should be as small as possible. Figure 1 As shown.

[0047] Step SSA-3: The host 20 outputs an excitation digital signal with a continuous pulse width of 10-100 ms and an amplitude of 0.2-1 V; after passing through the DA digital-to-analog converter 21, it is converted into an excitation analog signal with a continuous pulse width of 10-100 ms and an amplitude of 0.2-1 V, and output to the power amplifier circuit 22; after the power amplifier circuit amplifies the power, it outputs a pulse excitation current with a continuous pulse width of 10-100 ms and an amplitude of 1-5 A to the excitation coil 11 connected in series in the array probe 10; at the same time, the induced voltage time-domain signals u1(t), u2(t), u3(t) and u4(t) at both ends of the four detection coils 12 in the array probe 10 are synchronously acquired by four independent AD analog-to-digital converters, in V, and the synchronously acquired induced voltage time-domain signals are stored in the host 20.

[0048] Step 2: Method for extracting characteristic quantities of pulsed eddy current induced voltage signal (FEP).

[0049] In this invention, the process by which the host processes the induced voltage signal synchronously acquired by the array probe and extracts the feature vector of the pulsed eddy current detection signal is called the Feature Extraction Procedure (FEP), as follows:

[0050] After synchronously acquiring the induced voltages across the four detection coils in the array probe 10 according to the SSA procedure, the key to signal processing in pulsed eddy current detection is how to process these detection signals and quickly extract the detection feature quantities that reflect the wall thickness changes below each channel coil. Since the inspected steel pipe is a ferromagnetic pipe that is both conductive and magnetic, and ferromagnetic pipes have good magnetic permeability, the time-domain induced voltage signal will approximately decay exponentially in the later stages. If the induced voltage signal u... j Taking the logarithm of (t), we transform it into... (The subscript j represents different channels 1, 2, 3, and 4 within the array probe). Then, plotted on a linear coordinate system, the induced voltage signal in the later stage can be approximated as a straight line. Based on this variation characteristic, the signal feature extraction steps in this invention are as follows:

[0051] Step FEP-1: The time-domain signal u of the induced voltage across the j-th channel detection coil, synchronously acquired in the SSA step, is then processed. j (t) take the logarithm to the base 10, that is (The subscript j represents different channels 1, 2, 3, and 4 within the array probe), and then plotted in a coordinate system, as shown below. Figure 4 As shown in the figure, the horizontal axis represents the detection time. (Unit: seconds), with the vertical axis representing the logarithm of the induced voltage to base 10 (unit: V).

[0052] Step FEP-2, for Figure 4 Linear fitting is performed on the latter half of the induced voltage detection signal to obtain the induced voltage fitting straight line. , Figure 4 This is a schematic diagram illustrating the extraction of feature quantities of the straight line segment of the induced voltage detection signal of the j-th channel in the above array probe;

[0053] Step FEP-3: Extract the slope of the fitted straight line segment of the induced voltage. As a detection feature quantity, the detection feature quantity magnetic permeability of the inspected steel pipe Electrical conductivity and the remaining wall thickness below the corresponding j-th channel coil The relationship between them is:

[0054] (1)

[0055] The magnetic permeability of the steel pipe being inspected is expressed in H / m.

[0056] The electrical conductivity of the steel pipe being inspected is expressed in S / m.

[0057] The remaining wall thickness below the coil of the j-th channel at the inspection point of the inspected steel pipe is expressed in meters (m).

[0058] In step FEP-4, take the logarithm (base 10) of the time-domain signals u1(t), u2(t), u3(t), and u4(t) of the induced voltages across the detection coils of each channel, which were synchronously acquired in step SSA. Following steps FEP-1 to FEP-3 above, extract the signal feature quantities of each channel and form a feature vector. .

[0059] Step 3: Calibration of the proportional coefficient (CSF) of the signal characteristic quantity of the inspected metal pipe.

[0060] Generally speaking, common grades of steel pipes are ferromagnetic materials that are both electrically and magnetically conductive. Although they may have the same grade and similar microstructures, the magnetic permeability of the steel pipes varies. The magnetic permeability of steel pipes varies greatly depending on factors such as residual stress, pressure, temperature, and residual magnetism within the pipe. Therefore, it is impossible to select a steel pipe of the same specification as the one being tested as a standard test block to calibrate the characteristic quantity of the induced voltage signal, which means it is impossible to determine the proportional coefficient in equation (1) using a standard test block.

[0061] In this invention, any point can be selected within the same section of the inspected metal pipe 30 to measure the product of the permeability and conductivity preceding the signal characteristic quantity. This proportionality coefficient is used for calibration. In this invention, the host 20 senses the time-domain signal of the calibration point voltage. The process of analyzing and calibrating the product of the magnetic permeability and conductivity of the tested steel pipe using the characteristic quantities of the pulsed eddy current detection signal is called the calibration of the characteristic quantity proportionality coefficient, or CSF for short, as follows:

[0062] Step CSF-1: Select any detection point and mark it as the calibration point. The remaining wall thickness at the calibration point is measured using electromagnetic ultrasound or ultrasonic methods and recorded as follows: .

[0063] Step CSF-2: Place the array probe 10 vertically along the radial direction of the pipe inside the pipe being inspected, minimizing the lift-off distance between the lower edge of the array probe and the inner surface of the pipe, and align the coil of the first channel of the array probe 10 with the calibration point. The position can also be aligned with the calibration point using the coil of the 2nd, 3rd, or 4th channel;

[0064] Step CSF-3: Calibrate the points using a multi-channel pipe-penetrating pulsed eddy current testing system. Pulsed eddy current testing was performed, and calibration points were simultaneously acquired following the SSA procedure. Time-domain signal of induced voltage at the location It is stored in host 20;

[0065] Step CSF-4: The host 20 will set the calibration point Time-domain signal of induced voltage Take the logarithm to the base 10, that is Then, plot it on a coordinate system, and then, following the FEP procedure, extract the slope of the later straight line segment of the induced voltage at the calibration point. Detection feature quantity used as calibration point.

[0066] The slope of the straight line fitted from the later linear segment of the induced voltage described above. It can determine the product of the magnetic permeability and electrical conductivity of the tested steel pipe. for:

[0067] (2)

[0068] In the formula, The magnetic permeability of the steel pipe being inspected; The electrical conductivity of the steel pipe being inspected is expressed in S / m. The remaining wall thickness at the calibration point of the inspected steel pipe is expressed in meters (m).

[0069] Step 4: Scan the remaining wall thickness (SWT) at different locations on the inspected pipe.

[0070] The purpose of using a multi-channel pipe-penetrating pulsed eddy current testing system to inspect pipelines is to extract signal characteristic quantities by continuously acquiring the attenuation process of the induced voltage time-domain signal, thereby scanning the degree of corrosion on the pipeline wall. This invention utilizes the detection characteristic vectors of each channel of the array probe. To determine the remaining wall thickness at different locations in the inspected pipeline, the specific steps are as follows:

[0071] Step SWT-1: Place the array probe 10 vertically along the radial direction of the pipe inside the metal pipe 30 to be inspected, minimizing the lift-off distance between the lower edge of the array probe 10 and the inner surface of the metal pipe 30. Mark the current position as the detection point. ;

[0072] Step SWT-2: Use a multi-channel pipe-penetrating pulsed eddy current testing system to test the points. Pulsed eddy current detection was performed, and the detection points were acquired synchronously according to the SSA procedure. The induced voltage time-domain signals u1(t), u2(t), u3(t), and u4(t) at the location are stored in the host 20;

[0073] Step SWT-3: Following the FEP procedure, the host 20 will detect the points. The time-domain signal of the induced voltage is taken as the logarithm to base 10, plotted on a coordinate system, and then the detection point is extracted. The slope of the linear segment in the later stage of the induced voltage is used as the detection characteristic quantity of the detection point. Store this feature vector in the host memory;

[0074] Step SWT-4: Substitute the scaling factor (2) calibrated in the CSF step into equation (1) to calculate the remaining wall thickness below the j-th channel coil at the detection point. With calibration point wall thickness at the location The ratio:

[0075] (3)

[0076] This allows us to calculate the relative change in wall thickness at the test point compared to the wall thickness at the calibration point, thus obtaining the corrosion status of the wall thickness of the inspected metal pipe 30. The wall thickness test results are then correlated with the location information of the test points and saved to the host computer 20.

[0077] Step SWT-5: Move the array probe 10 to the next inspection point of the inspected metal pipe 30. Repeat steps 2 through 4 until the wall thickness of the entire inspected metal pipe relative to the calibration point is plotted. By analyzing the relative changes in wall thickness, the location of 30mm wall thickness corrosion thinning in the inspected metal pipe can be identified, and the degree of wall thickness corrosion can be quantitatively assessed.

[0078] The solution in this embodiment can be selectively combined with solutions in other embodiments.

[0079] Example 3:

[0080] Please see Figure 1-5 Based on the above embodiments, the detection device for internal pipe corrosion detection is implemented in a specific example as follows:

[0081] The following is an example of using an internally penetrating pipe corrosion detection pulsed eddy current array probe and its detection device to perform pulsed eddy current detection on a section of steel pipe.

[0082] The object of the test was a No. 20 steel pipe with an outer diameter of 160 mm, a length of 1.2 m, and a wall thickness of 7.5 mm. To verify the accuracy of the testing system in detecting changes in wall thickness, a 400 mm long step with a remaining length of 5.5 mm was machined on the sample pipe.

[0083] Calibration point The calibration point is set at a wall thickness of 7.5 mm on the pipe. Following step three, the proportional coefficient of the signal characteristic quantity of the inspected pipe is calibrated. First, pulsed eddy current testing is performed on the calibration point of the steel pipe according to the SSA procedure. The obtained induced voltage time-domain detection signal is as follows: Figure 4 The midpoint is shown by the solid line. Then, following the FEP procedure, a straight line is fitted to the second half of the detected signal to extract the signal feature quantity of the marker. =-51.0, substituting into equation (2), the product of the magnetic permeability and electrical conductivity of the tested steel pipe is thus determined as: .

[0084] The array probe 10 is placed vertically along the radial direction of the pipe inside the pipe being inspected, so that the array probe 10 exactly crosses the pipe step. The coils of channels 1 and 2 are located at the 7.5 mm wall thickness, and the coils of channels 3 and 4 are located at the 5.5 mm wall thickness. The induced voltage detection signals of the four channels in the array probe are simultaneously acquired as follows: Figure 5 As shown. Similarly, following the FEP procedure, a straight line fit is performed on the latter half of the detection signal of each channel to extract the signal feature vector. Substituting into equation (3), the relative changes in the remaining wall thickness below each channel coil and the wall thickness at the calibration point are calculated respectively:

[0085] , ,

[0086] , .

[0087] The actual wall thickness change of the processed stepped thinning section relative to the intact pipe is: As can be seen, the fourth channel is completely located above the 5.5 mm step. The absolute error between the relative change in wall thickness measured using the detection feature quantity of this invention and the actual relative change in wall thickness of the stepped sample tube is only 2.4%, which can meet the detection requirements of pipeline corrosion in industrial sites. Furthermore, since the pulsed eddy current detection signal is the result of the combined effect of eddy currents in the coil foot area, the second channel located at the edge of the step is affected by the 5.5 mm step section of the pipe, lowering the detection result; while the third channel located at the edge of the step is affected by the 7.5 mm step section of the pipe, raising the detection result. Utilizing this variation pattern of the array probe at the edge of corrosion defects, the defect edge can be located and identified.

[0088] The above test results verify the feasibility and reliability of the pulsed eddy current array probe and its detection device in this invention for internal detection of pipeline corrosion.

[0089] The solution in this embodiment can be selectively combined with solutions in other embodiments.

[0090] Example 4:

[0091] Please see Figure 6 and Figure 7 Based on the above embodiments, the detection device for internal pipe corrosion detection has a moving device below the array probe 10. The moving device includes a fixed plate 40, a roller 42 below the fixed plate 40, a rod 43 rotatably connected to one side of the roller 42, and a first telescopic rod 45 fixedly connected to one end of the rod 43. The first telescopic rod 45 is configured to be multi-stage telescopic, and the telescopic end is fixedly connected to the rod 43.

[0092] Three sets of rollers 42 are arranged in a circular array around the rod 43, with one set of rollers 42 fixedly mounted on the fixed plate 40. The three sets of rollers 42 are fixedly connected as a whole by a connecting plate 44, which is a bent plate.

[0093] A pull bar 41 is provided between the fixed plate 40 and the roller 42. One side of the pull bar 41 is slidably connected to the fixed plate 40, and the other side is attached to the roller 42. The pull bar 41 and the roller 42 are tightly attached. By pulling the pull bar 41, it drives a set of rollers 42 to roll on the rod 43.

[0094] Specifically, in use, the first telescopic rod 45 can be fixed in position first, and the array probe 10 can be placed inside the metal pipe 30 to be inspected. The detection position of the array probe 10 can be moved by the first telescopic rod 45. When a small and precise adjustment of the detection position is required, the pull bar 41 can be manually pulled. The pull bar 41 can drive a set of rollers 42 to roll on the rod body 43, so that the other two sets of rollers 42 are driven on the rod body 43, thereby allowing the array probe 10 to be adjusted in a small and precise manner.

[0095] The solution in this embodiment can be selectively combined with solutions in other embodiments.

[0096] Example 5:

[0097] Please see Figure 8-10 Based on the above embodiments, the detection device for internal pipe corrosion detection has an adjustment device between the fixed plate 40 and the array probe 10. The adjustment device includes a bending plate 50. The bottom of the horizontal plate portion of the bending plate 50 is fixedly connected to the fixed plate 40. A first sliding plate 51 is fixedly installed on the horizontal plate portion of the bending plate 50, and a second sliding plate 52 is fixedly installed on one side of the first sliding plate 51.

[0098] A first slider 53 is slidably connected inside the first slide plate 51. A rotating shaft 54 ​​is installed inside the first slider 53. A movable plate 59 is movably connected to the rotating shaft 54. A second slider 56 is movably connected to one end of the movable plate 59. One end of the movable plate 59 is movably sleeved on the rotating shaft 54, and the other end is rotatably connected to the inside of the second slider 56. A pad 58 is fixedly installed on the inside of the second slider 56. A movable plate 55 is fixedly installed on one end of the pad 58.

[0099] The array probe 10 is provided in two sets. One end of the two sets of array probe 10 is hinged, and the hinge is fixed to the moving plate 55 by a pin. The two sets of array probe 10 can move freely around the hinge.

[0100] The other end of the two array probes 10 is connected to a bearing 510 through a column. The bearing 510 is sleeved on the column. A barb rod 513 is hinged to one side of the bearing 510. The right end of the barb rod 513 can be rotated through the bearing 510. A positioning post 512 is provided on one side of the barb rod 513. The positioning post 512 is fixedly installed on the vertical plate part of the bending plate 50.

[0101] A spring 511 is provided between the two sets of barbed rods 513 for connection, and the spring 511 can make the barbed rods 513 fit against the positioning post 512.

[0102] Furthermore, a second telescopic rod 57 is fixedly installed at one end of the horizontal plate portion of the bending plate 50. The telescopic end of the second telescopic rod 57 is fixedly connected to the rotating shaft 54. The second telescopic rod 57 can drive one set of rotating shafts 54 to move.

[0103] Specifically, in use, one end of the two array probes 10 can be hinged together, and the hinge is fixed to the moving plate 55 by a pin. By extending and retracting the second telescopic rod 57, the second telescopic rod 57 drives a set of rotating shafts 54 to move, thereby driving the first slider 53 to move within the first slide plate 51.

[0104] When the first slider 53 moves to the right, the rotating shaft 54 ​​pulls one end of the movable plate 59 to move to the right. At this time, due to the tilt of the movable plate 59, the height of the second slider 56 and the movable plate 55 decreases. As the first slider 53 continues to move, the second slider 56 can slide inside the second slide plate 52, thereby pulling the movable plate 55 to the right. Consequently, the two array probes 10 also move to the right. At the same time, the array probes 10 pull the right end of the hook rod 513 to the right. Under the action of the spring 511, the left ends of the two hook rods 513 can hook onto the positioning post 512, causing the two array probes 10 to tilt, forming a "V"-shaped structure. This allows the detection range and detection height inside the inspected metal pipe 30 to be changed.

[0105] When the first slider 53 moves to the left, it slowly lifts the movable plate 59, causing the second slider 56 and the movable plate 55 to press against the vertical plate of the bending plate 50. Then, the first slider 53 continues to move to the left, causing the movable plate 59 to rise further. The left ends of the two sets of barbed rods 513 can press against the positioning post 512, and can also support the two sets of array probes 10, thereby adjusting the detection range and detection height of the array probes 10.

[0106] It should be noted that the bearing 510 allows the right end of the barb 513 to rotate, making it easy to cooperate with the array probe 10 even when the height of the moving plate 55 rises or falls.

[0107] The solution in this embodiment can be selectively combined with solutions in other embodiments.

[0108] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection of this invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this invention, or equivalent structural, procedural, or functional transformations made using the description and drawings of this invention, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this invention.

Claims

1. A detection device for corrosion detection of internally penetrating pipelines, characterized in that: The device includes an array probe (10) mounted on a moving device. The moving device includes a fixed plate (40) with a roller (42) below the fixed plate (40). The roller (42) is rotatably connected to a rod (43). The moving device also includes a pull bar (41) for pulling the roller (42) to rotate. The array probe (10) is mounted on an adjustment device, which includes a liftable movable plate (55); one end of the array probe (10) is rotatably mounted on the movable plate (55), and the other end is fixed on the bending plate (50); Multiple rollers (42) are connected to each other in a ring and sleeved on the rod body (43). One set of rollers (42) is fixedly installed on the fixing plate (40). A first telescopic rod (45) is connected to the rod body (43). The first slide plate (51) is fixedly installed on the horizontal plate portion of the bending plate (50), and the second slide plate (52) is fixedly installed on one side of the first slide plate (51). A first slider (53) is slidably connected inside the first slide plate (51). A rotating shaft (54) is installed inside the first slider (53). A movable plate (59) is movably connected on the rotating shaft (54). A second slider (56) is movably connected to one end of the movable plate (59). One end of the movable plate (59) is movably sleeved on the rotating shaft (54), and the other end is rotatably connected to the inside of the second slider (56). A pad (58) is fixedly installed on the inside of the second slider (56). A movable plate (55) is fixedly installed on one end of the pad (58).

2. The detection device for internal pipeline corrosion detection according to claim 1, characterized in that: A pull bar (41) is provided between the fixed plate (40) and the roller (42).

3. The detection device for internal pipeline corrosion detection according to claim 1, characterized in that: One end of the array probe (10) is hinged, and the hinge is fixed to the movable plate (55) by a pin. The two array probes (10) can move freely around the hinge. The other end of the two array probes (10) is connected to a bearing (510) by a column. The bearing (510) is sleeved on the column. A barb rod (513) is hinged to one side of the bearing (510). A positioning post (512) is provided on one side of the barb rod (513). The positioning post (512) is fixedly installed on the vertical plate part of the bending plate (50). The two sets of barbed rods (513) are connected by a spring (511).

4. The detection device for internal pipeline corrosion detection according to claim 1, characterized in that: The array probe (10) consists of four sets of single-channel coils, each set of coils including a detection coil (12) and an excitation coil (11) connected to the detection coil (12). The outermost layer of the coil is fixedly encapsulated by the array probe housing (13).

5. The detection device for internal pipeline corrosion detection according to claim 1, characterized in that: A second telescopic rod (57) is fixedly installed at one end of the horizontal plate portion of the bending plate (50), and the telescopic end of the second telescopic rod (57) is fixedly connected to the rotating shaft (54).

6. The detection device for internal pipeline corrosion detection according to claim 1, characterized in that: The array probe (10) is controlled by a control system, which includes an AD analog-to-digital converter for receiving signals from the array probe (10), a host (20) for processing the signals from the AD analog-to-digital converter, a DA digital-to-analog converter (21) connected in communication with the host (20), a power amplifier circuit (22) connected in communication with the DA digital-to-analog converter (21), a sampling resistor (28) connected in communication with the power amplifier circuit (22), and an AD analog-to-digital converter (23) connected in communication with the sampling resistor (28).

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