Automatic orientation method of array eddy current detection sensor and detection device thereof

Abstract

The application discloses an automatic orientation method of an array type eddy current detection sensor and a detection device thereof, which is suitable for internal scanning detection devices of pipeline defects such as heat exchangers and the like, and is characterized by the following steps: a metal orientation device with a metal gravity ball is used to induce a signal on the eddy current detection sensor; the relative position between a detection coil of an array type eddy current sensor arranged in a ring in an eddy current detection probe and a metal orientation ball which always keeps vertical gravity is accurately analyzed; and the radial position of the eddy current detection probe in a pipeline to be detected is determined.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-destructive testing, in particular to a method and device for eddy current testing of in-service heat exchanger pipes, and more particularly to an automatic orientation method of an arrayed eddy current testing sensor and a testing device thereof. BACKGROUND

[0002] Non-destructive testing of in-service heat exchanger pipes usually adopts eddy current method, and the arrayed eddy current testing method is more and more widely used in major equipment such as nuclear power field. With the progress of technology and the needs of related testing and maintenance engineering, how to accurately orient the specific position of defects (or discontinuities) in the pipe has become a problem to be solved. As shown in FIG. 1, in the longitudinal direction of the heat exchanger pipe 1, the nylon guide tube 21 is usually used to push the testing probe 22 to move inside the heat exchanger pipe 1 for eddy current scanning detection, and the surface of the nylon guide tube 21 is marked or coded to provide orientation information, which is a technical solution used in the industry. This solution can only orient in the longitudinal direction of the heat exchanger pipe, but it is not easy to achieve the orientation result for the accurate orientation of the defect position information in the radial direction of the heat exchanger pipe. Since the nylon guide tube is usually transmitted for tens of meters, it is easy to rotate during scanning and moving, and the up-down and left-right directions of each arrayed coil cannot be predicted and determined.

[0003] In view of the above problems, the present application adopts the following technical solutions. SUMMARY

[0004] The purpose of the present application is to provide an automatic orientation method of an arrayed eddy current testing sensor and a testing device thereof, and the technical solutions are as follows:

[0005] An automatic orientation method of an arrayed eddy current testing sensor is suitable for an internal scanning and testing device of pipe defects such as heat exchangers, and the radial position orientation method is characterized in that the signal sensed by the metal orientation device with a metal gravity ball on the eddy current testing sensor is accurately analyzed to determine the relative position of the detection coil of the arrayed eddy current sensor arranged in a ring in the eddy current testing probe and the metal orientation ball always kept vertically by gravity, and the radial position of the eddy current testing probe in the pipe to be tested is determined. The specific method steps are as follows:

[0006] a. Signal calibration process: since the metal gravity ball of the metal orientation device is always kept at a point in the direction of gravity during the scanning and testing in the pipe, the signal values of a plurality of detection coils close to the metal gravity ball are selected as the calibration signal values for orientation detection at a fixed working frequency of the arrayed eddy current testing sensor during the calibration process;

[0007] b. Calibration value range determination: by comparing and analyzing the detection signals of two or more detection coils with metal gravity balls, the eddy current signal value detected by the detection coil closest to the metal gravity ball is determined as the standard calibration value;

[0008] c. Actual detection process: the detection device moves in the pipeline for eddy current scanning detection, and the real-time detection signal value is extracted, including the signal of the detection coil with the calibration value range in step b, and the gravity direction position of the gravity ball is oriented, so that the specific radial position of the detection probe is oriented according to the number of detection sensors.

[0009] Further, the calibration value range in step b is set as the signal value of the corresponding detection coil when the gravity ball is directly opposite the detection coil, which is the maximum value, that is, the gravity ball directly opposite the detection coil is defined as the tangent direction perpendicular to the annular array detection coil in the vertical direction of the gravity ball. That is, the direction when the angle between the gravity ball direction and the tangent of the array circle is 90 degrees.

[0010] Further, the calibration value range in step b is set as the signal value of the corresponding detection coil when the gravity ball is directly opposite the detection coil, which is the maximum value, that is, the gravity ball directly opposite the detection coil is defined as the tangent direction perpendicular to the annular array detection coil in the vertical direction of the gravity ball. That is, the direction when the angle between the gravity ball direction and the tangent of the array circle is 90 degrees.

[0011] Further, in the calibration value range in step b, the detection signal value of the same size signal of the two detection coils is taken as the intermediate value.

[0012] Further, the equivalent value of the calibration multiple quantitative angles between the intermediate value and the maximum value is used as the calculation of the specific orientation parameter value. The quantitative value data analysis in the intensive analysis stage can be used as the orientation calculation of the specific orientation parameter value.

[0013] Further, the calculation of the specific orientation parameter value is the equivalent value of the distance difference between the two detection coils and the gravity ball in the normal position by the signal difference value ratio to the signal maximum value, which is used as the accurate orientation of the specific position of the gravity ball directly corresponding to the position.

[0014] Further, when the detection probe has a certain deviation in the horizontal plane of the moving route in the pipeline, the length ratio of the two waist sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the directly corresponding position of the array sensor, and the accurate orientation of the specific position of the gravity ball directly corresponding to the position is calculated. Because the gravity ball is always protected at a vertical point under the action of gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial circular cross section of the annular array detection coil form an angle. In the orientation calculation process, the specific numerical value of the vector decomposition is used as the calculation equivalent value.

[0015] The application also discloses an automatic orientation detection device of the arrayed eddy current detection sensor, the detection device 2 comprises a pushing conduit (21) and a detection probe (22), the pushing conduit (21) is arranged in a long strip shape and extends into the detected pipeline (1), and the detection probe (22) is arranged to move in the detected pipeline (1) to scan and detect eddy current, and the detection probe (22) comprises a probe main body (221) and an arrayed eddy current detection sensor (222), the probe main body (221) is arranged to be conformed to the internal shape of the detected pipeline (1), and the arrayed eddy current detection sensor (222) is arranged to be a plurality of eddy current detection coils (222a, 222b, 222c, …, 222n) radially arranged on the probe main body (221), and the eddy current detection coils are arranged in a uniform radial array.

[0016] The arrayed eddy current detection sensor (222) further comprises a directional pointer (23) arranged on the inner diameter of the arrayed eddy current detection sensor (222) on the probe main body (221), the directional pointer (23) comprises a metal gravity ball (231), a swing rod (232) and a rotary joint (233), the metal gravity ball (231) is rotatably and freely mounted on the rotary joint (233) through the end of the swing rod (232), and the metal gravity ball (231) is always kept at a point in the gravity direction due to the gravity.

[0017] In the detection process, the signal value of the eddy current detection coil closest to the metal gravity ball (231) is extracted, the specific radial position of each detection sensor in the detection probe is determined, and the specific position of the detected defect signal in the radial direction of the detected pipeline is determined.

[0018] Further, the probe main body (221) is arranged as a hollow body, and the directional pointer (23) is arranged on the inner diameter center circle of the arrayed eddy current detection sensor (222).

[0019] Further, the rotary joint (233) of the directional pointer (23) is fixed on the inner diameter center circle of the arrayed eddy current detection sensor (222), the metal gravity ball (231) is freely connected through the swing rod (232) and freely rotates around the inner diameter center circle of the arrayed eddy current detection sensor (222), and the directional pointer (23) is mounted on the rolling shaft (231), wherein the rotary joint (233) is arranged on the rolling shaft (231).

[0020] According to the above technical solution, the present invention has the following beneficial effects: The present invention uses a gravity metal ball that can swing freely in an array ring coil, and uses the data information of the eddy current signal generated by the array detection coil and the gravity metal ball to calculate the direction orientation, thereby solving the problem that radial position orientation cannot be achieved in the internal moving scan detection of in-service heat exchanger pipes, while not affecting the normal operation of the array eddy current detection coil. Attached Figure Description

[0021] Figure 1 This is a longitudinal view of the detection device in use according to the preferred embodiment of the present invention.

[0022] Figure 2 A schematic diagram of the array eddy current detection sensor structure of the detection device according to the preferred embodiment of the present invention;

[0023] Figure 3 This is a cross-sectional horizontal view of the detection device in use according to the preferred embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram showing the orientation of the detection device according to the preferred embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram showing the orientation of the detection device according to the preferred embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram showing the orientation of the detection device according to the preferred embodiment of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] like Figures 1 to 6 As shown, an automatic orientation method for an array-type eddy current detection sensor is applicable to internal scanning and detection devices for pipe defects, such as heat exchangers. This radial orientation method utilizes a metal orientation device with a metal gravity ball to sense the signal on the eddy current detection sensor. The relative position of the detection coils of the annular array-type eddy current sensor within the eddy current detection probe and the metal orientation ball, which remains vertically aligned under gravity, is precisely analyzed to determine the radial position of the eddy current detection probe within the pipe being inspected. The specific steps are as follows:

[0029] a. Signal calibration process: During the scanning and detection inside the pipeline, the metal gravity ball of the metal orientation device always remains at a point in the direction of gravity; therefore, during the calibration process, the array-type eddy current detection sensor selects the signal values ​​detected by several detection coils close to the metal gravity ball at a fixed operating frequency as the calibration signal values ​​for orientation detection.

[0030] b. Calibration range determination: Compare and analyze two or more detection coils that have metal gravity ball detection signals, and determine the eddy current signal value detected when a certain detection coil is closest to the position of the metal gravity ball as the standard calibration value;

[0031] c. Actual detection process: The detection device moves inside the pipeline to perform eddy current scanning detection, extracting real-time detection signal values, including the position of the detection coil with signals within the calibration range of step b, oriented to the direction of gravity of the gravity ball, thereby determining the specific radial position of the detection probe according to the detection sensor number.

[0032] In step b, the calibration value range is set to the maximum value of the signal value of the detection coil directly corresponding to the position of the gravity ball. Specifically, "the gravity ball directly corresponding to the detection coil" is defined as the vertical direction of the gravity ball perpendicular to the tangent of the circular array detection coil. In other words, it's the direction when the gravity ball's direction forms a 90-degree angle with the tangent of the array circle of the detection coil.

[0033] The calibration value range in step b is set to the minimum value of the corresponding signal value of the detection coil that is perpendicular to the detection coil when the gravity ball is directly corresponding to the position of the detection coil.

[0034] In step b, the calibration range setting is to take the detection signal value when the two detection coils have the same signal strength as the intermediate value.

[0035] like Figure 4 As shown, the equivalent values ​​of multiple quantitative angles between the intermediate and maximum values ​​are used as the calculation of specific directional parameter values. These specific directional parameter values ​​can be calculated through big data value analysis and intensive analysis of phased decomposition of quantitative data.

[0036] like Figure 5 As shown, the specific orientation parameter value is calculated by taking the ratio of the difference between the two signals to the maximum value of the signal as the equivalent value of the difference between the distances L1 and L2 between the two detection coils and the corresponding position of the gravity ball, and using this as the precise orientation to calculate the specific position corresponding to the gravity ball.

[0037] like Figure 6As shown in FIG. 1, when the detection probe moves in the pipeline with a certain deviation from the horizontal plane, the length ratio of the difference between the two sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the corresponding position of the array sensor, to calculate the accurate direction of the specific position corresponding to the gravity ball. Because the gravity ball is always protected in a vertical point by gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial cross section of the annular array detection coil form an angle. In the orientation calculation process, the L1 and L2 specific values of the vector decomposition are used as the equivalent value for calculation.

[0038] As shown in FIG. 1, when the detection probe moves in the pipeline with a certain deviation from the horizontal plane, the length ratio of the difference between the two sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the corresponding position of the array sensor, to calculate the accurate direction of the specific position corresponding to the gravity ball. Because the gravity ball is always protected in a vertical point by gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial cross section of the annular array detection coil form an angle. In the orientation calculation process, the L1 and L2 specific values of the vector decomposition are used as the equivalent value for calculation. Figure 1 、 Figure 2 and Figure 3 As shown in FIG. 1, when the detection probe moves in the pipeline with a certain deviation from the horizontal plane, the length ratio of the difference between the two sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the corresponding position of the array sensor, to calculate the accurate direction of the specific position corresponding to the gravity ball. Because the gravity ball is always protected in a vertical point by gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial cross section of the annular array detection coil form an angle. In the orientation calculation process, the L1 and L2 specific values of the vector decomposition are used as the equivalent value for calculation.

[0039] As shown in FIG. 1, when the detection probe moves in the pipeline with a certain deviation from the horizontal plane, the length ratio of the difference between the two sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the corresponding position of the array sensor, to calculate the accurate direction of the specific position corresponding to the gravity ball. Because the gravity ball is always protected in a vertical point by gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial cross section of the annular array detection coil form an angle. In the orientation calculation process, the L1 and L2 specific values of the vector decomposition are used as the equivalent value for calculation. Figure 3 As shown in FIG. 1, when the detection probe moves in the pipeline with a certain deviation from the horizontal plane, the length ratio of the difference between the two sides of the triangle formed by the gravity ball and the two detection coils is used as the equivalent value, which is converted into the vector analysis calculation method of the corresponding position of the array sensor, to calculate the accurate direction of the specific position corresponding to the gravity ball. Because the gravity ball is always protected in a vertical point by gravity, when the detected pipeline is not completely horizontal, the detection probe is not horizontal, and the gravity ball and the radial cross section of the annular array detection coil form an angle. In the orientation calculation process, the L1 and L2 specific values of the vector decomposition are used as the equivalent value for calculation.

[0040] The above is one embodiment of the present invention. Furthermore, it should be noted that any equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the scope of protection of this patent.

Claims

1. An automatic orientation method for an array-type eddy current detection sensor, characterized in that... The signal sensed by the metal orientation device with a metal gravity ball on the eddy current sensor is used to accurately analyze the relative position of the detection coil of the ring-shaped array of eddy current sensors in the eddy current detection probe and the metal orientation ball that is always kept vertical by gravity. This analysis is used to determine the radial position of the eddy current detection probe in the pipe being inspected. The specific steps are as follows: a. Signal calibration process: During the scanning and detection inside the pipeline, the metal gravity ball of the metal orientation device always remains at a point in the direction of gravity; therefore, during the calibration process, the array-type eddy current detection sensor selects the signal values ​​detected by several detection coils close to the metal gravity ball at a fixed operating frequency as the calibration signal values ​​for orientation detection. b. Calibration range determination: Compare and analyze two or more detection coils that have metal gravity ball detection signals, and determine the eddy current signal value detected when a certain detection coil is closest to the position of the metal gravity ball as the standard calibration value. In the calibration range setting, take the detection signal value of the two detection coils with the same signal as the median value. The equivalent values ​​of multiple quantitative angles between the intermediate value and the maximum value are used as the calculation of specific orientation parameter values; The calculated specific orientation parameter values ​​are used as the precise orientation for calculating the specific position corresponding to the gravity sphere; c. Actual detection process: The detection device moves inside the pipeline to perform eddy current scanning detection, extracting real-time detection signal values, including the position of the detection coil with signals within the calibration range of step b, oriented according to the gravity direction of the gravity ball, thereby determining the specific radial position of the detection probe based on the detection sensor number.

2. The automatic orientation method for an array-type eddy current detection sensor according to claim 1, characterized in that... The calibration value range in step b is set to the maximum value when the gravity ball is directly corresponding to the detection coil position. That is, the gravity ball directly corresponding to the detection coil is defined as the tangent direction of the vertical direction of the gravity ball perpendicular to the detection coil of the ring array.

3. The automatic orientation method for an array-type eddy current detection sensor according to claim 2, characterized in that... The calibration value range in step b is set to the minimum value of the corresponding signal value of the detection coil that is perpendicular to the detection coil when the gravity ball is directly corresponding to the position of the detection coil.

4. The automatic orientation method for an array-type eddy current detection sensor according to claim 1, characterized in that... It also includes a vector analysis calculation method that uses the ratio of the lengths of the two sides of the triangle formed by the gravity ball and the detection coils on both sides as the equivalent value to calculate the precise orientation of the specific position corresponding to the gravity ball when the horizontal plane of the path of the detection probe moves in the pipe.

5. An automatic orientation detection device for an array-type eddy current detection sensor, comprising a push tube (21) and a detection probe (22), wherein the push tube (21) is configured as an elongated strip extending into the pipe (1) to be detected, and pushes the detection probe (22) to move within the pipe (1) to perform eddy current scanning detection, characterized in that... The detection probe (22) includes a probe body (221) and an array-type eddy current detection sensor (222). The probe body (221) is configured to conform to the internal shape of the pipe (1) being detected. The array-type eddy current detection sensor (222) is configured as a plurality of eddy current detection coils (222a, 222b, 222c...222n) radially surrounding the probe body (221). The eddy current detection coils are arranged in a uniform radial array. The device also includes an orientation pointer (23) on the inner diameter of the array-type eddy current detection sensor (222) disposed on the probe body (221). The orientation pointer (23) includes a metal gravity ball (231), a swing arm (232), and a rotary joint (233). The metal gravity ball (231) is rotatably and freely mounted on the rotary joint (233) through the end of the swing arm (232), so that the metal gravity ball (231) is always kept at a point in the direction of gravity due to the effect of gravity. Furthermore, during the detection process, the signal value of the eddy current detection coil closest to the metal gravity ball (231) is extracted to determine the specific radial position of each detection sensor in the detection probe, so as to determine the specific position of the detected defect signal in the radial direction of the pipe being detected.

6. The automatic orientation detection device for an array-type eddy current detection sensor according to claim 5, characterized in that... The probe body (221) is configured as an internal hollow body, and the orientation pointer (23) is set on the inner diameter center circle of the array-type eddy current detection sensor (222).

7. An automatic orientation detection device for an array-type eddy current detection sensor according to claim 6, characterized in that... The rotary joint (233) of the directional pointer (23) is fixed to the center of the inner diameter of the array-type eddy current detection sensor (222). The metal gravity ball (231) is freely connected by the swing rod (232) and rotates freely around the center circumference of the inner diameter of the array-type eddy current detection sensor (222). The directional pointer (23) is mounted on the rolling shaft, wherein the rotary joint (233) is set on the rolling shaft.

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