A sensor for measuring corrosion on the inner wall of a bent pipe

Abstract

This invention discloses a corrosion measurement sensor for the inner wall of a bend pipe, comprising a connecting ring at the end of the bend pipe, and an embedded measuring inner ring assembly between the connecting rings. The embedded measuring inner ring assembly includes a reference ring and a measuring ring. The structural shape of the measuring ring or the reference ring is the same as that of a curved ring cut according to a pre-set bend pipe structure using a curved ring cutting strategy. The reference ring and the measuring ring are provided with several marking points for resistance segmentation. The structural segments of the reference ring and the measuring ring corresponding to adjacent marking points serve as the segmented resistances to be measured. By real-time monitoring and obtaining the resistance ratio of each segmented resistance of the measuring ring and the reference ring, the average corrosion depth of the structural segment corresponding to each segmented resistance of the measuring ring is obtained. This invention solves the problem that existing dual-ring corrosion sensors have limited monitoring areas for bend pipes, failing to achieve full-area monitoring of bend pipes, thus hindering effective monitoring of the inner wall corrosion status of bend pipe sections in high-temperature and high-pressure oil and gas pipelines.

Description

Technical Field

[0001] This invention relates to the fields of corrosion monitoring systems and oil pipeline engineering, and in particular to a sensor for measuring corrosion on the inner wall of a bend pipe. Background Technology

[0002] Currently, there are many technologies for monitoring pipeline corrosion. Existing pipeline corrosion monitoring sensors, such as dual-ring corrosion sensors, have solved the problem of monitoring corrosion in straight pipelines to some extent. However, for pipelines with special shapes, such as bends, the existing dual-ring corrosion sensors have limited monitoring areas and cannot monitor the entire bend area. This results in the inability to effectively monitor the corrosion status of the inner wall of the pipe at the bend section of high-temperature and high-pressure oil and gas pipelines. Summary of the Invention

[0003] This invention provides a sensor for measuring corrosion on the inner wall of a bent pipe to overcome the above-mentioned technical problems.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A pipe bend inner wall corrosion measurement sensor includes pipe bend end connecting rings connected to straight oil pipeline sections at both ends, and a pipe embedded measurement inner ring assembly with measurement wires is provided between the pipe bend end connecting rings; The pipeline embedded measurement inner ring assembly includes a reference ring with an inner wall surface coated with insulation and anti-corrosion coating and a measurement ring with an inner wall surface not coated with insulation and anti-corrosion coating; the reference ring and the measurement ring are arranged adjacent to each other, and the shapes of the measurement ring and the reference ring are consistent with the shape of the curved ring segment cut from the pre-set bent pipe structure by the curved ring cutting strategy. The reference ring and the measuring ring are provided with several marking points for resistance segmentation, and the structural solid segments of the reference ring and the measuring ring corresponding to adjacent marking points are used as the segmented resistances to be measured. By real-time monitoring and obtaining the resistance ratio of each segmented resistance of the measuring ring and the reference ring, the average corrosion depth of the structural solid segment corresponding to each segmented resistance of the measuring ring is obtained. The average corrosion depth is used to characterize the corrosion of the inner wall of the bend.

[0005] Furthermore, the surface loop truncation strategy is specifically as follows: Obtain the pipe trajectory curve corresponding to the pre-set pipe bending structure; the pipe trajectory curve is to take the center point of the circle at different positions of the pre-set pipe bending structure as the trajectory feature point, and define the arc curve where each trajectory feature point is located as the pipe trajectory curve. Using the horizontal plane where the pipe trajectory curve is located as the reference plane, the pipe trajectory curve is divided into equal parts by a preset angle, thereby realizing the extraction of the curved ring at different positions of the pipe structure; the central angle is the angle corresponding to the arc curve.

[0006] Furthermore, the method for calibrating the marker sites is as follows: Obtain the axisymmetric plane corresponding to the reference ring or measuring ring, and the axisymmetric plane is perpendicular to the reference plane. The intersection of the axisymmetric plane and the curve of the pipe bend is defined as the segment center point. Using the center point of the segment as the tangent point, obtain the tangent line of the pipe bending trajectory curve in the reference plane; Using the tangent as a reference, several segmented circumferential tangents are obtained that are perpendicular to the axisymmetric plane and set at different intersection angles. The segmented circumferential tangents are used to intersect with the structural entity corresponding to the reference ring or measuring ring to obtain segmented sections with different cross-sectional shapes. The intersection line between the segmented section and the inner wall of the reference ring or measuring ring is used as the characteristic tangent, and the position point constituting the characteristic tangent is used as the marker point.

[0007] Furthermore, the method for obtaining the average corrosion depth of the structural entity segment corresponding to each segment resistance of the measuring ring is as follows: S1: Let the radius of the arc corresponding to the pipe bend trajectory curve be... The arc angle of the center of the trajectory curve corresponding to each measurement loop or reference loop is defined as... The inner diameter of the measuring ring or reference ring is r, and the outer diameter is R; S2: Obtain the infinitesimal area of ​​the annular cross-section of the segmented section. for:

[0008] In the formula: This represents the angle rotated along the curve of the bend, using the line connecting the center of the curve to the reference point set on the curve. ; Represents the radius of any point on the segmented cross section; Indicates the angle of intersection between the segmented cross section and the segmented circumferential tangent plane; Represents the differential symbol; S3: Based on the infinitesimal element of the annular cross-sectional area Obtain the cross-sectional area of ​​the ring The integral expression is:

[0009] S4: Obtain the annular cross-sectional area after integral solution. for:

[0010] S5: Based on the aforementioned annular cross-sectional area The segmented resistance of the corresponding structural segment of the reference loop or measurement loop is obtained as follows:

[0011] In the formula: The first reference loop or measuring loop A segmented resistor; This indicates that the area of ​​the annular cross-section is obtained by solving the integral. The solution formula obtains the reference loop or measurement loop corresponding to the first... The cross-sectional area of ​​each segment; Indicates the reference loop or measurement loop corresponding to the first The arc length of each structural segment; and the resistivity of the corresponding structural segments of the measuring ring and the reference ring. The length of the arc is equal to that of the circle. S6: When a set amount of gas or liquid flows through the pipeline and corrosion occurs on the inner wall of the pipeline, obtain the cross-sectional area of ​​the measuring ring after corrosion. for:

[0012] According to S5, the resistance change value of the segmented resistance of the corresponding structural segment of the measurement ring (4) after corrosion can be obtained. for:

[0013] In the formula: This indicates the cross-sectional area of ​​the measuring ring after corrosion. ; S7: Based on the resistance change value of the segmented resistance of the corresponding structural segment of the measuring ring. By comparing the segmented resistance of the reference ring with that of the measurement ring, the current inner diameter of the corresponding structural segment of the measurement ring can be obtained. for: In the formula: Indicates the resistance ratio; Based on the current inner diameter Calculate the first measurement ring The average corrosion depth of the structural segment corresponding to each segmented resistor for: .

[0014] Furthermore, it also includes several clamp structures and several chuck flanges; the chuck flanges are located around the reference ring and the measuring ring, as well as at the end of the bend end connecting ring that connects to the pipe embedded measuring inner ring assembly. Each clamp structure is fixedly connected to the chuck flange; The sidewall of the chuck flange is also provided with a sealing groove for accommodating a gasket.

[0015] Furthermore, it also includes a pressure chamber structure fitted onto the outside of the inner ring assembly for embedded measurement in the pipeline; Both ends of the pressure chamber structure are fixedly connected to the end connecting ring of the bend pipe connected to the straight oil pipeline section, and a connecting sealing gasket is provided between the pressure chamber structure and the pipeline embedded measurement inner ring assembly, and between the pressure chamber structure and the end connecting ring of the bend pipe.

[0016] Furthermore, the reference ring, the measuring ring, and the bend end connecting ring connected to the straight oil pipeline section are made of the same material.

[0017] Beneficial Effects: This invention provides a corrosion measurement sensor for the inner wall of a bend pipe. By setting up a pipe-embedded measurement inner ring assembly with a partitioned measurement ring and a reference ring suitable for bend pipe structures, the sensor monitors and obtains the resistance ratio of each segment of the measurement ring and the reference ring during corrosion measurement. This allows for the determination of the average corrosion depth of the corresponding structural segment, thereby achieving real-time monitoring of the corrosion state of the bend pipe's inner wall. The measurement ring uses the same bend pipe material as the actual pipe and undergoes a surface coating process to ensure its inner wall condition is completely consistent with the pipe section being measured, thus accurately reflecting the corrosion status and rate. The reference ring, with its fully coated design, only contrasts with the measurement ring at the corroded inner wall, effectively eliminating interference from environmental factors such as temperature, pressure, and media, further improving the accuracy of corrosion measurement. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a side view of the corrosion measurement sensor for the inner wall of the bent pipe of the present invention. Figure 2 This is a three-dimensional structural diagram of the corrosion measurement sensor for the inner wall of the bend in this embodiment; Figure 3 This is a schematic cross-sectional view of the corrosion measurement sensor for the inner wall of the bend in this embodiment. Figure 4 This is a three-view diagram of the measuring ring or reference ring in this embodiment; Figure 5 This is an assembly diagram of the pressure chamber structure in this embodiment; Figure 6 This is an exploded view of the pressure chamber structure and the corrosion measurement sensor on the inner wall of the bend in this embodiment; Figure 7 This is a schematic diagram of the equal division of the bent pipe in this embodiment; Figure 8This is a schematic diagram of the marking site in this embodiment; Figure 9 This is a schematic diagram of the segmented cross-section in this embodiment; Figure 10 This is a schematic diagram illustrating the measurement of the ring marker site and the segmented resistance in this embodiment; Figure 11 This is a schematic diagram of the reference ring marker site and the segmented resistor in this embodiment.

[0020] In the diagram: 1. Straight oil pipeline section; 2. Connecting ring at the end of the bend; 3. Reference ring; 4. Measuring ring; 5. Chuck flange; 6. Sealing groove; 7. Pressure chamber structure; 8. Clamp structure; 9. Connecting sealing gasket. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This embodiment provides a sensor for measuring corrosion on the inner wall of a bent pipe, such as... Figures 1 to 2 As shown, the device includes a bend end connecting ring 2 that connects to the straight oil pipeline section 1 at both ends. An embedded measuring inner ring assembly with measuring wire A is provided between the bend end connecting rings 2. By embedding the measuring inner ring assembly into the actual pipeline, it better fits the axial monitoring of the pipeline and improves measurement accuracy. In this embodiment, high-performance conductive paste is applied to copper screws to connect and tighten the measuring wires of the measuring ring 4 and the reference ring 3. Specifically, in this embodiment, the oil and gas pipeline, i.e., the oil pipeline, is used as the straight pipe section at both ends of the bend being measured. The end face of the pipeline connected to the bend is machined only to form a matching flange. Bolts and flange gaskets are used to connect and seal the oil and gas pipeline to both ends of the pressure chamber structure 7. This embodiment also includes several clamp structures 8 and several chuck flanges 5; the chuck flanges 5 are disposed around the reference ring 3 and the measuring ring 4, and at the end of the bend end connecting ring 2 connected to the pipe embedded measuring inner ring assembly, forming an integral structure; each clamp structure 8 is fixedly connected to the chuck flange 5; the clamp structure 8 is used to fix the flange assembly to realize the connection of the reference ring 3, the measuring ring 4, and the bend end connecting ring 2, the fixed flange assembly includes adjacent chuck flanges 5 between the reference ring 3 and the measuring ring 4, adjacent chuck flanges 5 between the reference ring 3 and the bend end connecting ring 2, and adjacent chuck flanges 5 between the measuring ring 4 and the bend end connecting ring 2; as Figure 3As shown, the side wall of the chuck flange 5 is also provided with a sealing groove 6 for accommodating the sealing gasket. In this embodiment, the connection structure between the measuring ring 4, the reference ring 3 and the end connecting ring is designed as a chuck flange 5, which can be directly connected to the clamp sealing gasket by the clamp structure 8 for fastening and sealing. In addition, it can also be designed as an arc bolt connection or flange connection, etc., depending on the size of the bend. This embodiment also includes a pressure chamber structure 7 fitted onto the outside of the pipe-embedded measurement inner ring assembly; such as Figures 5 to 6 As shown, the two ends of the pressure chamber structure 7 are respectively fixedly connected to the bend end connecting ring 2 connected to the straight oil pipeline section 1. Connecting sealing gaskets 9 are provided between the pressure chamber structure 7 and the pipeline embedded measurement inner ring assembly, and between the pressure chamber structure 7 and the bend end connecting ring 2. In this embodiment, the pressure chamber structure 7 serves as an outer chamber for protecting the pipeline embedded measurement inner ring assembly. The pipeline embedded measurement inner ring assembly is placed inside the pressure chamber through a two-half structure. Both the end of the pressure chamber and the end of the pipeline embedded measurement inner ring assembly are provided with threaded holes and connected by bolts. A pressure chamber and measurement inner ring connecting sealing gasket 9 is provided between the corresponding end faces of the pressure chamber and the embedded measurement inner ring assembly. The two halves of the pressure chamber are connected and sealed by the pressure chamber sealing gasket and bolts. The pressure chamber structure 7 is also equipped with a cable outlet hole and a cable outlet sealing structure. The cable outlet sealing structure can be designed with a corresponding sealing level based on empirical values ​​and the operating conditions of the environment. The cable outlet hole is used to lead out the sensor's measuring wire and collect the sensor's signal through an externally pre-installed acquisition device. The pipe-embedded measurement inner ring assembly includes a reference ring 3 with an inner wall surface coated with insulation and anti-corrosion coating, and a measurement ring 4 with an inner wall surface not coated with insulation and anti-corrosion coating. The reference ring 3 and the measurement ring 4 are arranged adjacent to each other, and the shapes of the measurement ring 4 and the reference ring 3 are consistent with the shape of the curved ring segment cut from the pre-set bend structure through a curved ring cutting strategy. The pipe-embedded measurement inner ring assembly is an assembly composed of at least one pair of reference rings 3 and measurement rings 4, end connecting rings, and their fixing and sealing connectors, including lead wires, which serve as the core sensor component for measuring the corrosion depth and corrosion of the bend's inner wall. Specifically, as shown... Figure 7 As shown, the curved ring interception strategy is as follows: Obtain the curved pipe trajectory curve corresponding to the pre-set curved pipe structure; the curved pipe trajectory curve is defined as the center point of the circle at different positions of the pre-set curved pipe structure as the trajectory feature point, and the arc curve where each trajectory feature point is located is defined as the curved pipe trajectory curve; using the horizontal plane where the curved pipe trajectory curve is located as the reference plane, the curved pipe trajectory curve is divided into equal parts at a preset angle within a 90-degree angle, thereby realizing the interception of the curved ring at different positions of the curved pipe structure; the central angle is the angle corresponding to the arc curve; in this embodiment, the curved pipe is different from a straight pipe, and the intercepted measurement ring 4 or reference ring 3 is a non-uniform, progressively changing curved ring segment. The reference ring 3 and the measuring ring 4 are provided with several marking points for resistance segmentation, and the structural segments of the reference ring 3 and the measuring ring 4 corresponding to adjacent marking points are used as the segmented resistances to be measured. Specifically, the calibration method for the marked points is as follows: Obtain the axisymmetric plane corresponding to the reference ring 3 or the measuring ring 4, wherein the axisymmetric plane is perpendicular to the reference plane, and the intersection point of the axisymmetric plane and the pipe trajectory curve is defined as the segment center point; using the segment center point as the tangent point, obtain the tangent line of the pipe trajectory curve in the reference plane; and using the tangent line as the reference, obtain several segmented circumferential sectional surfaces that are perpendicular to the axisymmetric plane and set at different intersection angles; the segmented circumferential sectional surfaces are used to intersect with the structural entity corresponding to the reference ring 3 or the measuring ring 4 to obtain segmented sections with different cross-sectional shapes, such as... Figure 9 As shown; the intersection line between the segmented cross section and the inner wall of the reference ring 3 or the measuring ring 4 is taken as the characteristic tangent line, and the position point constituting the characteristic tangent line is taken as the marker point. For example... Figure 8 As shown, Z represents the reference point; B represents the axisymmetric plane; C represents the reference plane; D represents the segment center point; E represents the bend trajectory curve; F represents the segmented circumferential section; G represents the tangent line of the bend trajectory curve; H represents the vertical plane; J represents the cross section; in this embodiment, the measuring ring 4 and the reference ring 3 are divided into resistance segments by injecting three currents in the same direction at corresponding positions of the measuring ring 4 and the reference ring 3, as shown. Figures 10 to 11 The currents in the three directions I1, I2, and I3 marked in the figure can be used to obtain the resistance ratio between the measuring ring 4 and the reference ring 3. Furthermore, points M2, M4, M6, M8, 10, and 12 in the figure are the resistance measurement connection points corresponding to the measuring ring; points M1, M3, M5, M7, M9, and 11 are the current injection connection points corresponding to the measuring ring; R1, R2, R3, R4, R5, and R6 are the segmented resistors corresponding to the measuring ring; points 14, 16, 18, 20, 22, and 24 are the resistance measurement connection points of the reference ring corresponding to points M2, M4, M6, M8, 10, and 12 of the measuring ring; points 13, 15, 17, 19, 21, and 23 are the current injection connection points corresponding to the reference ring; R1 ’ R2 ’ R3 ’ R4 ’ R5 ’ R6 ’The reference ring corresponds to the segmented resistance. In this embodiment, a set of measuring rings 4 and reference ring 3 are initially identical in size, differing only in surface coating. The inner wall of measuring ring 4 is uncoated and used to measure corrosion depth, while reference ring 3 is fully coated and will never corrode. By comparing the resistances of the two rings, the corrosion depth of measuring ring 4 is monitored, reflecting the actual corrosion of the pipeline. The function of reference ring 3 is for comparison and temperature compensation. Therefore, when measuring the resistances of measuring ring 4 and reference ring 3, the segments of measuring ring 4 and reference ring 3 must be identical and corresponding.

[0023] By real-time monitoring and obtaining the resistance ratio of each segment resistance corresponding to the measuring ring 4 and the reference ring 3, the average corrosion depth of the structural solid segment corresponding to each segment resistance of the measuring ring 4 is obtained. The average corrosion depth is used to characterize the corrosion of the inner wall of the bend. Specifically, in this embodiment, the method for obtaining the average corrosion depth of the structural solid segment corresponding to each segment resistance of the measuring ring 4 is as follows: S1: Let the radius of the arc corresponding to the pipe bend trajectory curve be... Define the arc angle of the center of the trajectory curve corresponding to each measurement ring 4 or reference ring 3 as . And the inner diameter of measuring ring 4 or reference ring 3 is r, and the outer diameter is R; S2: Obtain the infinitesimal area of ​​the annular cross-section of the segmented section. for:

[0024] In the formula: This represents the angle rotated along the curve of the bend, using the line connecting the center of the curve to the reference point set on the curve. ; Represents the radius of any point on the segmented cross section; Indicates the angle of intersection between the segmented cross section and the segmented circumferential tangent plane; Represents the differential symbol; S3: Based on the infinitesimal element of the annular cross-sectional area Obtain the cross-sectional area of ​​the ring The integral expression is:

[0025] S4: Obtain the annular cross-sectional area after integral solution. for:

[0026] S5: Based on the aforementioned annular cross-sectional area The segmented resistance of the corresponding structural segment of reference ring 3 or measurement ring 4 is obtained as follows:

[0027] In the formula: This indicates the reference ring 3 or the measuring ring 4. A segmented resistor; This indicates that the area of ​​the annular cross-section is obtained by solving the integral. The solution formula obtains the reference ring 3 or the measurement ring 4 corresponding to the first... The segmented cross-sectional area, that is, the cross-sectional area of ​​different positions of the corresponding reference ring 3 or measuring ring 4, based on the formula corresponding to S4 in this embodiment; This indicates that reference ring 3 or measurement ring 4 corresponds to the first... The arc length of each structural segment; and the resistivity of the corresponding structural segments of the measuring ring 4 and the reference ring 3. The length of the arc is equal to that of the circle. S6: When a set amount of gas or liquid flows through the pipeline and corrosion occurs on the inner wall of the pipeline, obtain the cross-sectional area of ​​the measuring ring 4 after corrosion. for:

[0028] Based on S5, the resistance change value of the segmented resistance of the corresponding structural segment of the measurement ring 4 after corrosion can be obtained. for:

[0029] In the formula: This indicates the cross-sectional area of ​​the measuring ring 4 after corrosion. ; S7: Based on the resistance change value of the segmented resistance of the corresponding structural segment of ring 4. By comparing the segmented resistance of reference ring 3, the current inner diameter of the corresponding structural segment of measurement ring 4 is obtained. for: In the formula: Indicates the resistance ratio; Based on the current inner diameter The fourth measuring ring was calculated. The average corrosion depth of the structural segment corresponding to each segmented resistor for: .

[0030] In this embodiment, after the gas and liquid flow normally through the pipe for a period of time, corrosion occurs on the inner wall of the pipe. By monitoring the changes in the resistance of each segment of the measuring ring 4, the average corrosion depth of the structural entity segment where the corresponding segment resistance of the measuring ring 4 is located can be calculated by comparing the resistance ratio with that of the reference ring 3, i.e., the corrosion condition of the inner wall of the bend.

[0031] The device described in this embodiment addresses the limitation of the original dual-ring corrosion sensor, which can only measure straight pipe sections. However, in actual oil and gas pipelines, the most severe corrosion often occurs in bends. This embodiment improves upon the design of bend connection methods, sealing methods, resistance zones, and corresponding average corrosion depth calculation algorithms to achieve a feasible structural and calculation scheme for bend corrosion monitoring. Compared to existing technologies, the beneficial effects of the device described in this embodiment are as follows: 1. Since the original pipeline corrosion sensor only measures straight pipe sections, the erosion corrosion at pipe bends is more severe in actual engineering applications and needs to be detected. The device described in this embodiment achieves corrosion monitoring of the inner wall of the bend by designing a bend section connection structure suitable for bend locations, a partitioned structure of measuring ring 4 and reference ring 3, and a corresponding average corrosion depth calculation method. 2. Improved accuracy through the selection of pipe bend materials and coating processes: The pipe-embedded measurement inner ring component of the double-ring corrosion sensor is made from the bend of the actual monitored pipe. Through coating treatment, the state of the corrosion section on the inner wall of the sensor is completely consistent with that of the actual pipe, enabling more accurate measurement of the corrosion state and corrosion rate of the measured pipe section. A reference ring 3 is set up and fully coated. The only difference between the reference ring 3 and the inner wall of the measurement ring 4 is the corrosion inner wall, which is controlled as a variable. This effectively eliminates the influence of environmental factors such as temperature, pressure, and medium, further improving the accuracy of corrosion measurement. 3. The pressure chamber enables high reliability and high application adaptability of the double-ring corrosion sensor for bent pipes: The device described in this embodiment is equipped with a pressure chamber structure 7, which effectively protects the embedded measurement inner ring component and its measurement wires in the pipeline, making the double-ring corrosion sensor for bent pipes highly reliable and highly sealed. The pressure chamber structure 7 is divided into two symmetrically arranged bent pipe structures and is equipped with flanges, outlet holes, bolt holes and other structural components to facilitate installation. The flange specifications can also be adjusted to adapt to the required sealing level according to the application environment, improving the adaptability of the double-ring corrosion sensor for bent pipes. The pressure chamber structure 7 has flange connection structures at both ends, which can be directly flange-connected to the measured pipeline and sealed, greatly improving the convenience of on-site installation.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sensor for measuring corrosion on the inner wall of a bent pipe, characterized in that, Includes a bend end connecting ring (2) that is connected to the straight oil pipeline section (1) at both ends, and a pipe embedded measuring inner ring assembly with measuring wires is provided between the bend end connecting rings (2); The pipe-embedded measurement inner ring assembly includes a reference ring (3) with an inner wall surface coated with insulation and anti-corrosion coating and a measurement ring (4) with an inner wall surface not coated with insulation and anti-corrosion coating; the reference ring (3) and the measurement ring (4) are arranged adjacent to each other, and the shapes of the measurement ring (4) and the reference ring (3) are consistent with the shape of the curved ring segment cut from the pre-set bent pipe structure by the curved ring cutting strategy; The specific strategy for extracting the curved surface loop is as follows: Obtain the pipe trajectory curve corresponding to the pre-set pipe bending structure; the pipe trajectory curve is to take the center point of the circle at different positions of the pre-set pipe bending structure as the trajectory feature point, and define the arc curve where each trajectory feature point is located as the pipe trajectory curve. Using the horizontal plane where the pipe trajectory curve is located as the reference plane, the pipe trajectory curve is divided into equal parts by a preset angle, thereby realizing the extraction of the curved ring at different positions of the pipe structure; the central angle is the angle corresponding to the arc curve. The reference ring (3) and the measuring ring (4) are provided with several marking points for resistance segmentation, and the structural solid segments of the reference ring (3) and the measuring ring (4) corresponding to adjacent marking points are used as the segmented resistances to be measured. The resistance ratio of each segmented resistance of the measuring ring (4) and the reference ring (3) is obtained by real-time monitoring, and the average corrosion depth of each segmented resistance of the measuring ring (4) corresponding to the structural solid segments is obtained. The average corrosion depth is used to characterize the corrosion of the inner wall of the bend.

2. The bend pipe inner wall corrosion measurement sensor according to claim 1, characterized in that, The specific method for calibrating the marker sites is as follows: Obtain the axisymmetric plane corresponding to the reference ring (3) or the measuring ring (4), and the axisymmetric plane is perpendicular to the reference plane. The intersection of the axisymmetric plane and the curve of the pipe bend is defined as the segment center point. Using the center point of the segment as the tangent point, obtain the tangent line of the pipe bending trajectory curve in the reference plane; And based on the tangent, obtain a number of segmented circumferential tangents that are perpendicular to the plane of axisymmetry and set at different intersection angles; the segmented circumferential tangents are used to intersect with the structural entities corresponding to the reference ring (3) or the measuring ring (4) to obtain segmented sections with different cross-sectional shapes; the intersection line of the segmented section with the inner wall of the reference ring (3) or the measuring ring (4) is used as the characteristic tangent, and the position point constituting the characteristic tangent is used as the mark point.

3. The bend pipe inner wall corrosion measuring sensor according to claim 2, characterized in that, The method for obtaining the average corrosion depth of the structural solid segment corresponding to each segment resistance of the measuring ring (4) is as follows: S1: Let the radius of the arc corresponding to the pipe bend trajectory curve be... The arc angle of the center of the trajectory curve corresponding to each measurement ring (4) or reference ring (3) is defined as follows: And the inner diameter of the measuring ring (4) or the reference ring (3) is r, and the outer diameter is R; S2: Obtain the infinitesimal area of ​​the annular cross-section of the segmented section. for: In the formula: This represents the angle rotated along the curve of the bend, using the line connecting the center of the curve to the reference point set on the curve. ; Represents the radius of any point on the segmented cross section; Indicates the angle of intersection between the segmented cross section and the segmented circumferential tangent plane; Represents the differential symbol; S3: Based on the infinitesimal element of the annular cross-sectional area Obtain the cross-sectional area of ​​the ring The integral expression is: S4: Obtain the annular cross-sectional area after integral solution. for: S5: Based on the cross-sectional area of ​​the ring section The segmented resistance of the corresponding structural segment of the reference ring (3) or measurement ring (4) is obtained as follows: In the formula: This indicates the first reference ring (3) or measuring ring (4). A segmented resistor; This indicates that the area of ​​the annular cross-section is obtained by solving the integral. The solution formula obtains the reference ring (3) or measurement ring (4) corresponding to the first... The cross-sectional area of ​​each segment; This indicates that the reference ring (3) or measurement ring (4) corresponds to the first The arc length of each structural segment; and the resistivity of the corresponding structural segments of the measuring ring (4) and the reference ring (3). The length of the arc is equal to that of the circle. S6: When a set amount of gas or liquid flows through the pipe and corrosion occurs on the inner wall of the pipe, obtain the cross-sectional area of ​​the measuring ring (4) after corrosion. for: According to S5, the resistance change value of the segmented resistance of the corresponding structural segment of the measurement ring (4) after corrosion can be obtained. for: In the formula: This indicates the cross-sectional area of ​​the corroded measuring ring (4). ; S7: Based on the resistance change value of the segmented resistance of the corresponding structural entity segment of the measuring ring (4) By comparing the segmented resistance of the reference ring (3), the current inner diameter of the corresponding structural segment of the measuring ring (4) is obtained. for: In the formula: Indicates the resistance ratio; Based on the current inner diameter The first measurement ring (4) is calculated. The average corrosion depth of the structural segment corresponding to each segmented resistor for: 。 4. A corrosion measurement sensor for the inner wall of a bent pipe according to claim 3, characterized in that, It also includes several clamp structures (8) and several chuck flanges (5); the chuck flanges (5) are located around the reference ring (3) and the measuring ring (4), and at the end of the bend end connecting ring (2) connected to the pipe embedded measuring inner ring assembly; Each of the clamp structures (8) is fixedly connected to the chuck flange (5); The side wall of the chuck flange (5) is also provided with a sealing groove (6) for accommodating the sealing gasket.

5. A corrosion measuring sensor for the inner wall of a bent pipe according to claim 4, characterized in that, It also includes a pressure chamber structure (7) fitted on the outside of the inner ring assembly for embedded measurement in the pipeline. The two ends of the pressure chamber structure (7) are respectively fixedly connected to the bend end connecting ring (2) connected to the straight oil pipeline section (1), and the pressure chamber structure (7) and the pipeline embedded measurement inner ring assembly, and the pressure chamber structure (7) and the bend end connecting ring (2) are provided with connecting sealing gaskets (9).

6. A corrosion measuring sensor for the inner wall of a bent pipe according to claim 1, characterized in that, The reference ring (3), the measuring ring (4), and the bend end connecting ring (2) connected to the straight oil pipeline section (1) are made of the same material.

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