Pressure pipeline corrosion deformation detection device and method

Abstract

The application relates to a pressure pipeline corrosion deformation detection device and method, relates to the field of pressure pipeline detection, can improve the digitalization and automation level of measurement, makes the detection result more comprehensive, and improves the detection quality. In the pressure pipeline corrosion deformation detection device, the control terminal can be used for setting the running speed of a pipe outer measurement module and a pipe inner measurement module along the pipeline axis outside or inside the pipeline, the rotating speed of a laser ranging sensor along the circumferential direction of the pipeline, the sampling interval of a laser ranging position along the pipeline axis direction, and controlling the pipe inner measurement module to automatically return to the measurement starting position after running for a certain distance or remaining a certain amount of electricity; the control terminal can be used for receiving the measurement data returned by the pipe outer measurement module or the pipe inner measurement module after the measurement task is completed, including displacement data, angle data and laser ranging data; the pipe outer measurement module and the pipe inner measurement module respectively comprise a processor, a data communication unit, a motion control assembly and a data acquisition assembly connected with the processor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure pipeline detection, and particularly relates to a pressure pipeline corrosion and deformation detection device and method. BACKGROUND

[0002] The pressure pipeline is an important equipment in industrial production and is widely used in the fields of petrochemical industry, metallurgical industry and the like. The medium transmitted in the pressure pipeline usually has the properties of high pressure, flammable, explosive, toxic, high temperature or low temperature. Therefore, the leakage and explosion of the pressure pipeline often causes serious consequences of group death and group injury, and causes huge economic losses and environmental pollution.

[0003] At present, as a kind of special equipment for public safety, the safety of the pressure pipeline is highly valued by the using units, the inspection units and the supervision units; in China, under the premise that the using units bear the main responsibility for the safety of the pressure pipeline, the pressure pipeline implements the periodic inspection and supervision inspection system, and the inspection process is performed by the special equipment inspection institutions authorized by the State Administration for Market Regulation.

[0004] Among them, the corrosion and deformation detection is an important content in the safety condition inspection process of the pressure pipeline. The corrosion is mainly caused by the corrosion of the inner wall material of the pressure pipeline by the transported medium, which causes the thinning of the pipe wall, and the deformation is usually caused by the local indentation of the inner wall of the pipeline due to the impact of the external object on the pipe wall during use.

[0005] In the prior art, the periodic inspection of the pressure pipeline generally needs to be stopped and the medium in the pipe is emptied. The traditional corrosion inspection method generally uses a thickness gauge to measure the wall thickness outside the pipeline, and the corrosion thinning condition of the pipe wall is checked. The measurement method is point measurement, and there are problems of limited coverage of the measurement position and low measurement efficiency. The traditional pipeline deformation detection generally uses a macroscopic detection method of human eye vision, which is not convenient for quantitative evaluation of the deformation degree. SUMMARY

[0006] The purpose of the present application is to provide a pressure pipeline corrosion and deformation detection device and method, which can effectively improve the digitalization level and automation level of measurement, so as to make the detection result more comprehensive, and thus improve the detection quality and ensure the safe and stable operation of the pressure pipeline.

[0007] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0008] A kind of pressure pipeline corrosion deformation detection device, comprising: control terminal, and with the control terminal respectively through wireless communication connection pipe outside measurement module and pipe inside measurement module;The control terminal can be used to set the operation speed of the pipe outside measurement module and the pipe inside measurement module along the axis of pipeline outside or inside pipe, the rotation speed of laser ranging sensor along the circumferential direction of pipeline, the sampling interval of laser ranging position along the direction of pipeline axis, and the pipe inside measurement module is automatically recalled to the measurement starting position after controlling the pipe runs for how long or remaining how much electric quantity;The control terminal can be used to receive the measurement data that the pipe outside measurement module or the pipe inside measurement module is transmitted back after executing measurement task, including displacement data, angle data, laser ranging data;

[0009] The pipe outside measurement module and the pipe inside measurement module respectively include: processor, and with the processor respectively connected data communication unit, motion control component and data acquisition component;The motion control component includes: linear motion control unit and rotary motion control unit;The data acquisition component includes: displacement data acquisition unit, angle data acquisition unit and laser ranging data acquisition unit.

[0010] In practical application, the displacement data is displacement-time sequence from motion starting point, along the axial distance of pipeline starting point;

[0011] The angle data is the angle that laser ranging sensor points to different parts of pipeline when displacement measurement is carried out, and the angle range is 0~360°;

[0012] The laser ranging data is the distance of laser ranging probe from the outer surface or inner surface of pipeline, and the distance is the distance of 360° different directions.

[0013] Wherein, the linear motion control unit controls the measurement module to move along the axial direction of pipeline by electromechanical control, when laser ranging data acquisition is needed, stop moving, then the rotary motion control unit controls the laser ranging sensor of laser ranging data acquisition unit to rotate, to realize the size measurement of different positions of the same cross section of outer surface or inner surface of pipeline.

[0014] Specifically, the laser ranging sensor points to the center of pipeline and rotates continuously for 360°, and the distance of measurement sensor from the outer surface of pipeline is L1, simultaneously the angle data acquisition unit collects the rotation angle of laser ranging sensor as θ, and obtains "L1-θ" data sequence;

[0015] D1 is the circumference of the end of laser ranging sensor rotating circular track, then the outer radius R1 of pipeline is: R1=D1 / 2-L1.

[0016] Further, the laser ranging sensor is directed to the center of the pipeline for 360° continuous rotation, and the distance between the measuring sensor and the inner surface of the pipeline is L2, and the angle data acquisition unit acquires the rotation angle of the laser ranging sensor as θ, and obtains the "L2-θ" data sequence.

[0017] D2 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the inner radius R2 of the pipeline is R2=D2 / 2+L2.

[0018] Further, the part of the end of the laser ranging sensor corresponds to the distance measured by the laser ranging sensor as 0.

[0019] Further, the wall thickness t of the pipeline is t=R1-R2.

[0020] R1 at different angles has no obvious change, R2 between θ1 and θ2 increases, it is judged that the pipeline has inner wall corrosion at the cross section, and the corrosion position is located between θ1 and θ1; the part with the minimum t has the minimum residual wall thickness of the pipeline, which is the most serious corrosion position; that is, the pipeline inner corrosion will cause R2 to increase and R1 to remain unchanged.

[0021] Further, the deformation of the pipeline does not change the wall thickness of the pipeline, that is, t=R1-R2, but affects the values of R1 and R2 at the same position, that is, R1 and R2 are both smaller in the same angle θ range.

[0022] A pressure pipeline corrosion deformation detection method, a laser ranging sensor is directed to the center of the pipeline for 360° continuous rotation, and the distance between the measuring sensor and the outer surface of the pipeline is L1, and the angle data acquisition unit acquires the rotation angle of the laser ranging sensor as θ, and obtains the "L1-θ" data sequence; D1 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the outer radius R1 of the pipeline is R1=D1 / 2-L1.

[0023] The laser ranging sensor is directed to the center of the pipeline for 360° continuous rotation, and the distance between the measuring sensor and the inner surface of the pipeline is L2, and the angle data acquisition unit acquires the rotation angle of the laser ranging sensor as θ, and obtains the "L2-θ" data sequence; D2 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the inner radius R2 of the pipeline is R2=D2 / 2+L2.

[0024] The wall thickness t of the pipeline is t=R1-R2; R1 at different angles has no obvious change, R2 between θ1 and θ2 has a change of being larger, so that it is judged that the pipeline has inner wall corrosion at the cross section, and the corrosion position is located between θ1 and θ1; the position with the minimum t has the minimum residual wall thickness of the pipeline, which is the most serious corrosion position, that is, the pipeline inner corrosion will cause R2 to be larger and R1 to be unchanged; the pipeline deformation will not change the wall thickness of the pipeline, that is, t=R1-R2, but will affect the values of R1 and R2 at the same position, that is, R1 and R2 are both smaller within the same angle θ range.

[0025] Compared with the prior art, the pressure pipeline corrosion deformation detection device and method has the following advantages:

[0026] The pressure pipeline corrosion deformation detection device and method provided by the application, since the operation control terminal can be used for setting the running speed of the pipe outside measurement module and the pipe inside measurement module along the pipeline axis outside or inside the pipeline, the rotation speed of the laser ranging sensor along the circumferential direction of the pipeline, the sampling interval of the laser ranging position along the pipeline axis direction, and controlling the pipe inside measurement module to automatically return to the measurement starting position after running for a certain distance or after the remaining power is less than a certain value; the control terminal can be used for receiving the measurement data returned by the pipe outside measurement module or the pipe inside measurement module after the measurement task is completed, including displacement data, angle data and laser ranging data; the pipe outside measurement module and the pipe inside measurement module respectively include a processor and a data communication unit, a motion control component and a data acquisition component connected with the processor; the motion control component includes a linear motion control unit and a rotary motion control unit; the data acquisition component includes a displacement data acquisition unit, an angle data acquisition unit and a laser ranging data acquisition unit; at the same time, the laser ranging sensor is directed to the pipeline center for 360° continuous rotation, and the distance between the measurement sensor and the outer surface of the pipeline is L1, at the same time, the angle data acquisition unit acquires the rotation angle of the laser ranging sensor as θ, and obtains the "L1-θ" data sequence; D1 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the outer radius R1 of the pipeline is R1=D1 / 2-L1; and the laser ranging sensor is directed to the pipeline center for 360° continuous rotation, and the distance between the measurement sensor and the inner surface of the pipeline is L2, at the same time, the angle data acquisition unit acquires the rotation angle of the laser ranging sensor as θ, and obtains the "L2-θ" data sequence; D2 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the inner radius R2 of the pipeline is R2=D2 / 2+L2; the wall thickness t of the pipeline is t=R1-R2; R1 at different angles has no obvious change, R2 between θ1 and θ2 is larger, and it is judged that the pipeline has inner wall corrosion at the cross section, and the corrosion position is located between θ1 and θ1; the pipeline with the smallest t has the smallest residual wall thickness, which is the most serious corrosion position, that is, the pipeline inner corrosion will cause R2 to become larger and R1 to remain unchanged; the pipeline deformation will not change the wall thickness of the pipeline, that is, t=R1-R2, but will affect the values of R1 and R2 at the same position, that is, R1 and R2 will become smaller within the same angle θ range; therefore, the pressure pipeline corrosion deformation detection device and method provided by the application can effectively improve the digitalization level and the automation level of measurement, so that the detection result is more comprehensive, and the detection quality is improved, and the safe and stable operation of the pressure pipeline is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The frame structure diagram of the pressure pipeline corrosion deformation detection device provided by the embodiment of the application is shown in the figure.

[0028] Figure 2This is a schematic diagram of the cross-sectional structure measured by the external pipe measurement module in the pressure pipeline corrosion and deformation detection device provided in an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the longitudinal section structure measured by the external pipe measurement module in the pressure pipeline corrosion and deformation detection device provided in an embodiment of the present invention.

[0030] Figure 4 A schematic diagram of the cross-sectional structure measured by the in-pipe measurement module in the pressure pipeline corrosion and deformation detection device provided in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the longitudinal section structure measured by the pipe-in-pipe measurement module in the pressure pipeline corrosion and deformation detection device provided in an embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram illustrating the principle of corrosion detection on the inner wall of a pipeline in a pressure pipeline corrosion deformation detection device provided in an embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram illustrating the pipeline deformation detection principle in the pressure pipeline corrosion and deformation detection device provided in this embodiment of the invention. Detailed Implementation

[0034] For ease of understanding, the pressure pipeline corrosion and deformation detection device and method provided in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] This invention provides a pressure pipeline corrosion and deformation detection device, such as... Figures 1-7 As shown, it includes: a control terminal (which can be a handheld smart terminal, such as an industrial tablet computer, laptop computer, or other module capable of computation and control functions with wireless communication), and an external pipe measurement module and an internal pipe measurement module connected to the control terminal via wireless communication; the control terminal can be used to set the running speed of the external pipe measurement module and the internal pipe measurement module along the pipe axis outside or inside the pipe, the rotation speed of the laser ranging sensor along the circumference of the pipe, the sampling interval of the laser ranging position along the pipe axis, and to control the internal pipe measurement module to automatically return to the measurement start position after running a certain distance in the pipe or after having a certain amount of power remaining; the control terminal can be used to receive the measurement data transmitted back by the external pipe measurement module or the internal pipe measurement module after completing the measurement task, including displacement data, angle data, and laser ranging data;

[0036] The outer-pipe measurement module and the inner-pipe measurement module each comprise a processor, a data communication unit, a motion control assembly and a data acquisition assembly connected to the processor respectively; the motion control assembly comprises a linear motion control unit and a rotary motion control unit; and the data acquisition assembly comprises a displacement data acquisition unit, an angle data acquisition unit and a laser ranging data acquisition unit.

[0037] The embodiment of the present application further provides a pressure pipeline corrosion deformation detection method, as shown in the figure, the laser ranging sensor is directed to the pipeline center for 360 continuous rotation, and the distance between the measurement sensor and the outer surface of the pipeline is L1, at the same time, the angle data acquisition unit collects the rotation angle of the laser ranging sensor as θ, and obtains the "L1-θ" data sequence; D1 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the outer radius R1 of the pipeline is R1=D1 / 2-L1. Figures 1-7

[0038] The laser ranging sensor is directed to the pipeline center for 360 continuous rotation, and the distance between the measurement sensor and the inner surface of the pipeline is L2, at the same time, the angle data acquisition unit collects the rotation angle of the laser ranging sensor as θ, and obtains the "L2-θ" data sequence; D2 is the circumference of the rotation circle track at the end of the laser ranging sensor, and the inner radius R2 of the pipeline is R2=D2 / 2+L2.

[0039] The wall thickness t of the pipeline is t=R1-R2; R1 at different angles has no obvious change, R2 between θ1 and θ2 is larger, so that it is judged that the pipeline has inner wall corrosion at the cross section, and the corrosion position is located between θ1 and θ1; the position with the minimum t has the minimum residual wall thickness of the pipeline, and is the most serious corrosion position, that is, the inner corrosion of the pipeline will cause R2 to be larger and R1 to be unchanged; the pipeline deformation will not change the wall thickness of the pipeline, that is, t=R1-R2, but will affect the values of R1 and R2 at the same position, that is, R1 and R2 are both smaller within the same angle θ range.

[0040] Compared with the prior art, the pressure pipeline corrosion deformation detection device and method have the following advantages:

[0041] ​In the pressure pipeline corrosion and deformation detection device and method provided in this invention embodiment, the operation control terminal can be used to set the running speed of the external and internal measurement modules along the pipeline axis, the rotation speed of the laser ranging sensor along the pipeline circumference, the sampling interval of the laser ranging position along the pipeline axis, and to control the internal measurement module to automatically return to the measurement start position after traveling a certain distance in the pipeline or having a certain amount of remaining power. The control terminal can also receive measurement data transmitted back by the external or internal measurement modules after completing the measurement task, including displacement data, angle data, and laser ranging data. The external and internal measurement modules each include a processor, and a data communication unit, a motion control component, and a data acquisition component connected to the processor. The motion control component includes a linear motion control unit and a rotary motion control unit. The data acquisition components include: a displacement data acquisition unit, an angle data acquisition unit, and a laser ranging data acquisition unit. Simultaneously, the laser ranging sensor rotates continuously 360° towards the center of the pipe, measuring the distance L1 between the sensor and the outer surface of the pipe. The angle data acquisition unit acquires the rotation angle θ of the laser ranging sensor, obtaining a data sequence "L1-θ". D1 is the circumference of the circular trajectory of the laser ranging sensor's end, so the outer radius R1 of the pipe is: R1 = D1 / 2 - L1. Furthermore, the laser ranging sensor rotates continuously 360° towards the center of the pipe, measuring the distance L2 between the sensor and the inner surface of the pipe. The angle data acquisition unit acquires the rotation angle θ of the laser ranging sensor, obtaining a data sequence "L2-θ". D2 is the circumference of the circular trajectory of the laser ranging sensor's end, so the inner radius R2 of the pipe is: R2 = D2 / 2 + L2; the pipe wall thickness t is: t = R1 - R2; R1 does not change significantly at different angles, but R2 increases between θ1 and θ2, indicating that there is internal wall corrosion in the pipe at this cross-section, and the corrosion location is between θ1 and θ2; the part with the smallest t has the smallest remaining pipe wall thickness, which is the most severely corroded location, meaning that internal corrosion in the pipe will cause R2 to increase while R1 remains unchanged; pipe deformation will not change the pipe wall thickness, i.e., t = R1 - R2, but it will affect the values ​​of R1 and R2 at the same location, i.e., R1 and R2 both decrease within the same angle θ range; therefore, the pressure pipe corrosion deformation detection device and method provided in this embodiment of the invention can effectively improve the digitalization and automation level of measurement, thereby making the detection results more comprehensive, improving the detection quality, and ensuring the safe and stable operation of pressure pipelines.

[0042] In practical applications, such as Figures 1-7 As shown, the above displacement data is a displacement-time series along the axial direction of the pipe from the starting point of the movement to the starting point of the movement.

[0043] The angle data is the angle of the laser ranging sensor when it points to different parts of the pipeline for displacement measurement, and the angle range is 0~360°.

[0044] The laser ranging data is the distance between the laser ranging probe of the laser ranging sensor and the outer surface or inner surface of the pipeline.

[0045] As shown in Figures 1-7 , the above linear motion control unit controls the movement of the measurement module along the axis of the pipeline by electromechanical control. When laser ranging data collection is needed, the movement is stopped, and then the laser ranging sensor of the laser ranging data collection unit is rotated by the rotary motion control unit to realize the size measurement of different positions on the same cross section of the outer surface or inner surface of the pipeline.

[0046] Specifically, as shown in Figures 1-7 , in particular Figure 2 and Figure 3 , the laser ranging sensor points to the center of the pipeline for 360° continuous rotation, and the distance between the measurement sensor and the outer surface of the pipeline is L1. At the same time, the angle data collection unit collects the rotation angle of the laser ranging sensor as θ, and obtains the "L1-θ" data sequence.

[0047] D1 is the circumference of the circular track of the end of the laser ranging sensor, and the outer radius R1 of the pipeline is R1=D1 / 2-L1.

[0048] Further, as shown in Figures 1-7 , in particular Figure 4 and Figure 5 , the laser ranging sensor points to the center of the pipeline for 360° continuous rotation, and the distance between the measurement sensor and the inner surface of the pipeline is L2. At the same time, the angle data collection unit collects the rotation angle of the laser ranging sensor as θ, and obtains the "L2-θ" data sequence.

[0049] D2 is the circumference of the circular track of the end of the laser ranging sensor, and the inner radius R2 of the pipeline is R2=D2 / 2+L2.

[0050] Further, as shown in Figures 1-7 , the part of the end of the laser ranging sensor corresponds to the distance measured by the laser ranging sensor being 0.

[0051] Further, as shown in Figures 1-7 , in particular Figure 6 , the wall thickness t of the pipeline is t=R1-R2.

[0052] R1 does not change at different angles, R2 increases between θ1 and θ2, it is judged that there is inner wall corrosion in the cross section of the pipeline, and the corrosion position is located between θ1 and θ2; the position with the minimum t has the minimum residual wall thickness of the pipeline, which is the most serious corrosion position; that is, the inner corrosion of the pipeline will cause R2 to increase and R1 to remain unchanged.

[0053] It should be noted here that the data analyzed above are data of the same cross section of the pipeline, that is, data when the running distance S of the outer measurement module of the pipeline Figure 3 is consistent with the running distance S of the inner measurement module of the pipeline Figure 5 .

[0054] Further, as shown in Figures 1-7 , in particular Figure 7 , the deformation of the pipeline does not change the wall thickness of the pipeline, that is, t=R1-R2, but will affect the values of R1 and R2 at the same position, that is, R1 and R2 will both decrease within the same angle θ range.

[0055] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A pressure pipeline corrosion and deformation detection device, characterized in that, It includes: a control terminal, and an external pipe measurement module and an internal pipe measurement module connected to the control terminal via wireless communication; the control terminal can be used to set the running speed of the external pipe measurement module and the internal pipe measurement module along the pipe axis outside or inside the pipe, the rotation speed of the laser ranging sensor along the pipe circumference, the sampling interval of the laser ranging position along the pipe axis, and to control the internal pipe measurement module to automatically return to the measurement start position after running a certain distance in the pipe or after having a certain amount of power remaining; the control terminal can be used to receive the measurement data transmitted back by the external pipe measurement module or the internal pipe measurement module after completing the measurement task, including displacement data, angle data, and laser ranging data; The external measurement module and the internal measurement module each include: a processor, and a data communication unit, a motion control component, and a data acquisition component respectively connected to the processor; the motion control component includes: a linear motion control unit and a rotational motion control unit; the data acquisition component includes: a displacement data acquisition unit, an angle data acquisition unit, and a laser ranging data acquisition unit; The displacement data is a displacement-time series along the axial direction of the pipe from the starting point of the movement; the angle data is the angle rotated when the laser rangefinder sensor points to different parts of the pipe to measure displacement, and the angle range is 0~360°; the laser rangefinder data is the distance between the laser rangefinder probe and the outer or inner surface of the pipe obtained by the laser rangefinder sensor, and the distance is the distance in different directions of 360°. The linear motion control unit controls the measurement module to move along the pipeline axis via electromechanical control. When laser ranging data acquisition is required, the movement stops, and then the rotary motion control unit controls the laser ranging sensor of the laser ranging data acquisition unit to rotate, so as to realize the dimensional measurement of different positions of the same cross-section on the outer or inner surface of the pipeline.

2. The pressure pipeline corrosion and deformation detection device according to claim 1, characterized in that, The laser rangefinder rotates 360° continuously towards the center of the pipe, and measures the distance L1 between the sensor and the outer surface of the pipe. At the same time, the angle data acquisition unit acquires the rotation angle θ of the laser rangefinder and obtains the "L1-θ" data sequence. D1 is the circumference of the circular trajectory of the end of the laser rangefinder sensor. Then the outer radius R1 of the pipe is: R1 = D1 / 2 - L1.

3. The pressure pipeline corrosion and deformation detection device according to claim 2, characterized in that, The laser rangefinder rotates 360° continuously towards the center of the pipe, and measures the distance L2 between the sensor and the inner surface of the pipe. At the same time, the angle data acquisition unit acquires the rotation angle θ of the laser rangefinder and obtains the "L2-θ" data sequence. D2 is the circumference of the circular trajectory of the end of the laser rangefinder sensor. Then the inner radius R2 of the pipe is: R2=D2 / 2+L2.

4. The pressure pipeline corrosion and deformation detection device according to claim 3, characterized in that, The portion at the end of the laser rangefinder corresponds to a distance of 0 measured by the laser rangefinder.

5. The pressure pipeline corrosion and deformation detection device according to claim 4, characterized in that, The pipe wall thickness t is: t = R1 - R2; If R1 does not change significantly at different angles, and R2 increases between θ1 and θ2, it can be determined that there is internal wall corrosion in the same cross-section of the pipeline, and the corrosion location is between θ1 and θ2. The part with the smallest t has the smallest remaining wall thickness and is the most severely corroded location. That is, internal corrosion in the pipeline will cause R2 to increase while R1 remains unchanged.

6. The pressure pipeline corrosion and deformation detection device according to claim 5, characterized in that, Pipe deformation does not change the pipe wall thickness, i.e., t = R1 - R2, but it will affect the values ​​of R1 and R2 at the same location, i.e., R1 and R2 both decrease within the same angle θ range.

7. A method for detecting corrosion and deformation in pressure pipelines, characterized in that, Use the pressure pipeline corrosion and deformation detection device as described in claim 6 above; The laser rangefinder rotates 360° continuously towards the center of the pipe, and measures the distance L1 between the sensor and the outer surface of the pipe. At the same time, the angle data acquisition unit acquires the rotation angle θ of the laser rangefinder and obtains the "L1-θ" data sequence. D1 is the circumference of the circular trajectory of the laser rangefinder's end. Then the outer radius R1 of the pipe is: R1=D1 / 2-L1. The laser rangefinder rotates 360° continuously towards the center of the pipe, and measures the distance L2 between the sensor and the inner surface of the pipe. At the same time, the angle data acquisition unit acquires the rotation angle θ of the laser rangefinder and obtains the "L2-θ" data sequence. D2 is the circumference of the circular trajectory of the laser rangefinder's end. Then the inner radius R2 of the pipe is: R2=D2 / 2+L2. The pipe wall thickness t is: t = R1 - R2; R1 does not change significantly at different angles, but R2 increases between θ1 and θ2, indicating that there is internal wall corrosion in the same cross-section of the pipe, and the corrosion location is between θ1 and θ2; the part with the smallest t has the smallest remaining pipe wall thickness, which is the location of the most severe corrosion, that is, internal corrosion in the pipe will cause R2 to increase while R1 remains unchanged; pipe deformation will not change the pipe wall thickness, that is, t = R1 - R2, but it will affect the values ​​of R1 and R2 at the same location, that is, R1 and R2 both decrease within the same angle θ range.

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