Pipeline detection device based on long-gauge-length double-grating structure
By using the long-distance double-grating structure and sensor elastic parts in the pipeline detection device, the problems of installation damage, measurement error and narrow applicability of the pipeline detection structure in the prior art are solved, and the problem of harsh environments is realized. High sensitivity, accurate measurement and multi-size adaptability.
Patent Information
- Application Number
- CN202420759342.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-12
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-04-12
AI Technical Summary
The existing pipeline detection structure has intrusive installation, resulting in damage to the integrity and strength of the pipeline, complex wiring of the internal structure, and difficult to accurately measure under strong electromagnetic interference and strong corrosion environments, and the size is fixed and cannot be applied to multiple pipeline diameters, which poses safety hazards and Narrow applicability.
The pipeline detection device based on the long gauge double grating structure is adopted, including a detection fixture, a sensing elastic structure and a measurement structure. The long gauge double fiber grating and a fixed substrate are used to transmit the upper and lower elastic parts of the sensing upper and lower ends of the fixture are provided. The grooved, the sensing measurement structure is installed at the upper end of the upper elastic member, and the long gauge fiber grating is distributed parallel to the substrate. The fixture can be adjusted according to the pipe size, adapted to harsh environments, and the wiring is simple.
It realizes detection without damage to the pipeline, improves the applicability and sensitivity of the detection device, can accurately measure under strong electromagnetic interference and chemical corrosion environments, eliminates the impact of ambient temperature on the measurement results, and is suitable for a variety of pipe diameters.
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Figure CN222166472U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pipeline detection, in particular to a pipeline detection device based on a long gauge length double grating structure. Background Art
[0002] With the rapid development of industrial economy, the demand for resources such as oil and natural gas, which are vital to human development, is increasing. Oil and natural gas are usually transported by pipelines. Therefore, pipeline leakage monitoring is one of the focuses of pipeline operation status monitoring.
[0003] The existing pipeline leakage location and leakage degree can be reflected from the pipeline pressure measurement data. Therefore, it is necessary to measure the internal pressure of the pipeline. The existing pipeline detection structures mainly include the following: mainly resistive pressure sensors, capacitive pressure sensors, installed pressure gauge detection, installed pressure transmitter detection. The existing pipeline detection structure has the following shortcomings:
[0004] 1) The installation of existing resistive or capacitive pressure sensors is invasive and requires drilling holes in the pipeline for installation, which destroys the integrity and strength of the pipeline;
[0005] 2) The internal structure and wiring of existing resistive or capacitive pressure sensors are relatively complex, and the measurement errors in strong electromagnetic interference and strong corrosion environments make it difficult to ensure the accuracy of the measurement;
[0006] 3) To install a pressure gauge or pressure transmitter for testing, it is also necessary to open the pipeline and connect the pressure gauge or pressure transmitter to the pipeline structure through a valve to measure the internal pressure of the pipeline. This detection structure destroys the pipeline structure and poses a safety hazard to the long-term operation of the pipeline;
[0007] 4) The existing detection structure has a relatively fixed size and cannot be applied to pipes of various diameters, so its applicability is relatively narrow. Utility Model Content
[0008] The purpose of the utility model is to overcome the shortcomings of the prior art. The utility model provides a pipeline detection device that can adapt to harsh environments such as strong electromagnetic interference and strong chemical corrosion, and its installation does not damage the pipeline, the wiring method is simple, and the corresponding detection fixture can be designed according to the size of the measured pipeline. It is suitable for detecting and measuring pipelines with a variety of different diameters.
[0009] In order to solve the above technical problems, the utility model provides a pipeline detection device based on a long-gauge double-grating structure, the pipeline detection device includes a detection fixture for clamping pipeline detection, two groups of sensing elastic structures, and a sensing measurement structure, the upper and lower ends of the detection fixture are respectively provided with a first slot and a second slot, the two groups of sensing elastic structures include a sensing upper elastic member and a sensing lower elastic member, the sensing upper elastic member and the sensing lower elastic member are symmetrically distributed up and down, the sensing upper elastic member and the sensing lower elastic member are respectively installed at the first slot and the second slot at the upper and lower ends of the detection fixture, the sensing measurement structure is installed at the upper end of the sensing upper elastic member and is located at the first slot of the detection fixture, the sensing measurement structure includes a long-gauge double-grating structure and a fixed substrate, and the long-gauge double-grating structure is installed on the fixed substrate.
[0010] Furthermore, the long gauge dual grating structure includes a first long gauge fiber grating and a second long gauge fiber grating, the first long gauge fiber grating and the second long gauge fiber grating are spaced apart and distributed in parallel with each other, and the first long gauge fiber grating and the second long gauge fiber grating are fixed on the fixed substrate along the length direction of the fixed substrate.
[0011] Furthermore, the fixed substrate includes a left substrate and a right substrate, and the left substrate and the right substrate are symmetrically distributed on both sides of the upper end of the elastic member on the sensor, and the two ends of the first long gauge fiber grating and the second long gauge fiber grating are respectively fixed on the left substrate and the right substrate and located at the first groove at the upper end of the detection fixture, and the distance between the left substrate and the right substrate forms a fiber accommodating hollow area.
[0012] Furthermore, the detection clamp includes a first detection clamp and a second detection clamp, the first detection clamp and the second detection clamp are symmetrically spaced, the first slot is formed by the distance between the upper end of the first detection clamp and the upper end of the second detection clamp, the second slot is formed by the distance between the lower end of the first detection clamp and the lower end of the second detection clamp, and the distance between the first detection clamp and the second detection clamp forms a channel for clamping the pipe.
[0013] Furthermore, a first arc-shaped contact surface matching the outer shape of the pipeline is formed on the inner side of the first detection clamp, and a second arc-shaped contact surface matching the outer shape of the pipeline is formed on the inner side of the second detection clamp.
[0014] Further, the right end of the left substrate extends to the right to form a left extended fixing arm, the lower end of the left substrate extends downward to form a left extended fixing portion, the left end of the right substrate extends to the left to form a right extended fixing arm, the lower end of the right substrate extends downward to form a right extended fixing portion, the two ends of the first long gauge fiber grating are respectively fixed to the left extended fixing arm of the left substrate and the right extended fixing arm of the right substrate to achieve the fixation of the first long gauge fiber grating to the left and right substrates, and the two ends of the second long gauge fiber grating are respectively fixed to the left extended fixing portion of the left substrate and the right extended fixing portion of the right substrate to achieve the fixation of the second long gauge fiber grating to the left and right substrates.
[0015] Further, the pipeline detection device includes a first upper fastener, a second upper fastener, a first lower fastener, and a second lower fastener, the upper and lower ends of the first detection clamp are respectively provided with a first upper clamp fixing hole and a first lower caliper fixing hole, the upper and lower ends of the second detection clamp are respectively provided with a second upper clamp fixing hole and a second lower caliper fixing hole, the first upper fastener and the second upper fastener are respectively located at the first upper clamp fixing hole of the first detection clamp and the second upper clamp fixing hole of the second detection clamp, and the first lower fastener and the second lower fastener are respectively located at the first lower clamp fixing hole of the first detection clamp and the second lower clamp fixing hole of the second detection clamp.
[0016] Further, the left substrate of the fixed substrate is provided with a first substrate fastening hole matched with the first upper fastener, the position of the first substrate fastening hole corresponds to the position of the first upper clamp fixing hole at the upper end of the first detection clamp, the right substrate of the fixed substrate is provided with a second substrate fastening hole matched with the second upper fastener, and the two ends of the sensing elastic member are provided with a first upper elastic fixing hole and a second upper elastic fixing hole, the first upper fastener passes through the first substrate fastening hole of the left substrate, the first upper elastic fixing hole of the sensing elastic member, and the first upper clamp fixing hole of the first detection clamp from top to bottom in sequence so as to fix the left substrate and the sensing elastic member to the upper end of the first detection clamp, and the second upper fastener passes through the second substrate fastening hole of the right substrate, the second upper elastic fixing hole of the sensing elastic member, and the second upper clamp fixing hole of the second detection clamp in sequence from top to bottom so as to fix the right substrate and the other end of the sensing elastic member to the upper end of the second detection clamp.
[0017] Furthermore, a first lower elastic fixing hole and a second lower elastic fixing hole are provided at both ends of the lower elastic member of the sensor, the first lower fastener passes through the first lower elastic fixing hole of the lower elastic member of the sensor and the first lower clamp fixing hole at the lower end of the first detection clamp from bottom to top in sequence to fix one end of the lower elastic member of the sensor to the lower end of the first detection clamp, and the second lower fastener passes through the second lower elastic fixing hole of the lower elastic member of the sensor and the second lower clamp fixing hole at the lower end of the second detection clamp in sequence from bottom to top to fix the other end of the lower elastic member of the sensor to the lower end of the second detection clamp.
[0018] Furthermore, the first long-gauge fiber grating includes a first optical fiber, a plurality of first optical fiber gratings, and two groups of first pigtails, the plurality of first optical fiber gratings are equidistantly distributed in the middle region of the first optical fiber, and the two groups of first pigtails are distributed at both ends of the first optical fiber, and the second long-gauge fiber grating includes a second optical fiber, a plurality of second optical fiber gratings, and two groups of second pigtails, the plurality of second optical fiber gratings are equidistantly distributed in the middle region of the second optical fiber, and the two groups of second pigtails are distributed at both ends of the second optical fiber.
[0019] Compared with the prior art, the technical solution of the utility model has at least the following beneficial effects:
[0020] 1) The pipeline detection device provided by the utility model includes a detection fixture, two groups of sensing elastic structures, and a sensing measurement structure. The upper and lower ends of the detection fixture are respectively provided with a first slot and a second slot. The two groups of sensing elastic structures include a sensing upper elastic member and a sensing lower elastic member. The sensing upper elastic member and the sensing lower elastic member are symmetrically distributed in the upper and lower parts. The sensing upper elastic member and the sensing lower elastic member are respectively installed at the first slot and the second slot at the upper and lower ends of the detection fixture. The sensing measurement structure is installed at the upper end of the sensing upper elastic member and is located at the first slot of the detection fixture. The sensing measurement structure includes a long-gauge double grating structure and a fixed substrate. The long-gauge double grating structure is installed on the fixed substrate. The utility model has the sensing elastic structures at the upper and lower ends of the detection fixture with stretching and contraction effects, and can flexibly adjust the diameter size of the detection fixture according to different pipeline sizes, so that the pipeline detection device can be suitable for pipelines with different diameters, thereby improving the practicability of the pipeline detection device and having a wide range of applications. A sensing measurement structure is installed on the sensing upper elastic member at the upper end of the detection fixture, and the sensing measurement structure is provided with a long gauge length double grating structure and a fixed substrate, and can adapt to harsh environments such as strong electromagnetic interference and strong chemical corrosion, and the wiring installation method is very simple, which can reduce the operating difficulty of monitoring personnel.
[0021] 2) The long gauge length dual grating structure provided in the utility model includes a first long gauge length fiber grating and a second long gauge length fiber grating, and the first long gauge length fiber grating and the second long gauge length fiber grating are spaced apart and parallelly distributed between the left and right substrates. The pipeline detection device of the utility model can flexibly adjust the sensitivity of the sensing measurement structure by adjusting the effective length of the two long gauge length fiber gratings. Since the two long gauge length fiber gratings adopt a long gauge length structure, the radial strain of the pipeline can be significantly amplified. Compared with other types of fiber grating pipeline pressure sensors, it has a higher sensitivity. In addition, the long gauge length dual grating structure design can eliminate the influence of ambient temperature on the measurement results, so that the measurement data is not affected by the ambient temperature.
[0022] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the following is a detailed description in combination with the preferred embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0024] Figure 1 It is a schematic diagram of the overall structure of the pipeline detection device in the first embodiment of the utility model;
[0025] Figure 2 This is a schematic diagram of the connection relationship between the detection fixture, the sensing elastic structure, and the pipeline in the first embodiment of the utility model. Figure 1 ;
[0026] Figure 3 This is a schematic diagram of the connection relationship between the detection fixture, the sensing elastic structure, and the pipeline in the first embodiment of the utility model. Figure 2 ;
[0027] Figure 4 It is a schematic diagram of the relationship between the detection fixture and the sensing elastic structure in the first embodiment of the utility model;
[0028] Figure 5 It is a structural schematic diagram of the detection fixture in the first embodiment of the utility model;
[0029] Figure 6 It is a schematic diagram of the structure of the fixed substrate in the first embodiment of the utility model;
[0030] Figure 7 It is a structural schematic diagram of the upper elastic member of the sensor in the first embodiment of the utility model;
[0031] Figure 8 It is a structural schematic diagram of the lower elastic member of the sensor in the first embodiment of the utility model;
[0032] Fig. 9 It is a structural schematic diagram of the sensor measurement structure in the first embodiment of the utility model.
[0033] In the figure, a detection fixture 1, a first detection clamp 11, a second detection clamp 12, a first slot 13, a second slot 14, a sensing elastic structure 2, a sensing upper elastic member 21, a sensing lower elastic member 22, a sensing measurement structure 3, a fixed substrate 31, a left substrate 311, a left extended fixed arm 3111, a left extended fixed portion 3112, a right substrate 312, a right extended fixed arm 3121, a right extended fixed portion 3122, a long gauge double grating structure 32, a first long gauge fiber grating 321, a second long gauge fiber grating 322, a first upper fastener 4, a second upper fastener 5, a first lower fastener 6, a second lower fastener 7, and a pipe 8. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0035] Embodiment 1, as Figure 1-Figure 8 As shown, the utility model provides a pipeline 8 detection device based on a long-gauge double grating structure 32, the pipeline 8 detection device includes a detection fixture 1 for clamping the pipeline 8 for detection, two groups of sensing elastic structures 2, and a sensing measurement structure 3, the upper and lower ends of the detection fixture 1 are respectively provided with a first slot 13 and a second slot 14, the two groups of sensing elastic structures 2 include a sensing upper elastic member 21 and a sensing lower elastic member, the sensing upper elastic member 21 and the sensing lower elastic member are symmetrically distributed in the upper and lower parts, the sensing upper elastic member 21 and the sensing lower elastic member are respectively installed at the first slot 13 and the second slot 14 at the upper and lower ends of the detection fixture 1, the sensing measurement structure 3 is installed at the upper end of the sensing upper elastic member 21 and is located at the first slot 13 of the detection fixture 1, the sensing measurement structure 3 includes a long-gauge double grating structure 32 and a fixed substrate 31, and the long-gauge double grating structure 32 is installed on the fixed substrate 31.
[0036] The upper elastic sensing member 21 and the lower elastic sensing member 22 provided in the present invention are in a snake shape.
[0037] In specific implementation, the long-gauge dual-grating structure 32 of the utility model includes a first long-gauge fiber grating 321 and a second long-gauge fiber grating 322. The first long-gauge fiber grating 321 and the second long-gauge fiber grating 322 are spaced apart and distributed in parallel with each other. The first long-gauge fiber grating 321 and the second long-gauge fiber grating 322 are fixed on the fixed substrate 31 along the length direction of the fixed substrate 31, and the first long-gauge fiber grating 321 and the second long-gauge fiber grating 322 are located in the same horizontal plane. The fixed substrate 31 includes a left substrate 311 and a right substrate 312. The left substrate 311 and the right substrate 312 are symmetrically distributed on both sides of the upper end of the sensing elastic member 21. The two ends of the first long gauge fiber grating 321 and the second long gauge fiber grating 322 are respectively fixed on the left substrate 311 and the right substrate 312 and are located at the first slot 13 at the upper end of the detection fixture 1. The spacing between the left substrate 311 and the right substrate 312 forms a fiber accommodating hollow area. The pipeline 8 detection device of the utility model adjusts the effective length of the two long gauge fiber gratings to flexibly adjust the sensitivity of the sensing measurement structure 3. Since the two long gauge fiber gratings adopt a long gauge structure, the radial strain of the pipeline 8 can be significantly amplified. Compared with other types of fiber grating pipeline 8 pressure sensors, it has higher sensitivity. In addition, the pipeline 8 detection device adopts a long gauge dual grating structure 32 design, which can eliminate the influence of ambient temperature on the measurement results, so that the measurement data is not affected by the ambient temperature.
[0038] The pipeline 8 detection device provided in the utility model can achieve the effect of installation without damaging the pipeline 8. The equation relationship is established by using the change in the internal diameter of the pipeline 8 and the change measured by the fiber grating sensor. By measuring the strain value of the fiber grating sensor installed on the pipeline 8, the pressure value in the pipeline 8 can be effectively obtained, thereby monitoring the internal pressure of the pipeline 8 without damaging the structure of the pipeline 8. The corresponding detection fixture 1 can be designed according to the size of the measured pipeline 8. It is suitable for detection and measurement of pipelines 8 with various diameters, can adapt to harsh environments such as strong electromagnetic interference and strong chemical corrosion, and has a simple wiring method.
[0039] The fixed substrate 31 of the present invention is made of metal material and is integrally formed by wire cutting, which facilitates the production of the fixed substrate 31 , reduces the assembly process of the fixed substrate 31 , and improves the assembly efficiency of the fixed substrate 31 .
[0040] When the embodiment of the utility model is specifically implemented, the detection clamp 1 includes a first detection clamp 11 and a second detection clamp 12, the first detection clamp 11 and the second detection clamp 12 are symmetrically spaced, the first slot 13 is formed by the distance between the upper end of the first detection clamp 11 and the upper end of the second detection clamp 12, the second slot 14 is formed by the distance between the lower end of the first detection clamp 11 and the lower end of the second detection clamp 12, and the distance between the first detection clamp 11 and the second detection clamp 12 forms a channel for clamping the pipe 8. The distance between the first detection clamp 11 and the second detection clamp 12 of the detection clamp 1 is the gauge length of the first long gauge fiber grating 321 and the second long gauge fiber grating 322. The inner side of the first detection clamp 11 is formed with a first arc-shaped contact surface matching the outer shape of the pipe 8, and the inner side of the second detection clamp 12 is formed with a second arc-shaped contact surface matching the outer shape of the pipe 8. The first arc-shaped contact surface and the second arc-shaped contact surface are provided to facilitate the first detection clamp 11 and the second detection clamp 12 to be better sleeved on the outside of the pipe 8 and to better clamp the pipe 8 .
[0041] In a specific implementation, the right end of the left substrate 311 of the utility model extends rightward to form a left extended fixed arm 3111, the lower end of the left substrate 311 extends downward to form a left extended fixed portion 3112, the left end of the right substrate 312 extends leftward to form a right extended fixed arm 3121, the lower end of the right substrate 312 extends downward to form a right extended fixed portion 3122, the two ends of the first long gauge fiber grating 321 are respectively fixed to the left extended fixed arm 3111 of the left substrate 311 and the right extended fixed arm 3121 of the right substrate 312, and the two ends of the second long gauge fiber grating 322 are respectively fixed to the left extended fixed portion 3112 of the left substrate 311 and the right extended fixed portion 3122 of the right substrate 312. The first long gauge fiber Bragg grating 321 is applied to the left extended fixed arm 3111 of the left substrate 311 and the right extended fixed arm 3121 of the right substrate 312 by adhesive, so as to realize the fixation of the first long gauge fiber Bragg grating 321 to the left and right substrates 312; the second long gauge fiber Bragg grating 322 is applied to the left extended fixed part 3112 of the left substrate 311 and the right extended fixed part 3122 of the right substrate 312 by adhesive, so as to realize the fixation of the second long gauge fiber Bragg grating 322 to the left and right substrates 312. The first long gauge fiber Bragg grating 321 and the second long gauge fiber Bragg grating 322 are both connected to the two fixed substrates 31 by two points, so as to avoid the problems of fiber Bragg grating chirp, poor thermal stability and uneven stress caused by the wetting of adhesive.
[0042] The pipeline 8 detection device of the utility model comprises a first upper fastener 4, a second upper fastener 5, a first lower fastener 6, and a second lower fastener 7. The upper and lower ends of the first detection clamp 11 are respectively provided with a first upper clamp fixing hole and a first lower clamp fixing hole, and the upper and lower ends of the second detection clamp 12 are respectively provided with a second upper clamp fixing hole and a second lower caliper fixing hole, the first upper fastener 4 and the second upper fastener 5 are respectively located at the first upper clamp fixing hole of the first detection clamp 11 and the second upper clamp fixing hole of the second detection clamp 12, the first lower fastener 6 and the second lower fastener 7 are respectively located at the first lower clamp fixing hole of the first detection clamp 11 and the second lower clamp fixing hole of the second detection clamp 12, and the first upper fastener 4, the second upper fastener 5, the first lower fastener 6, and the second lower fastener 7 can be selected from screws.
[0043] In specific implementation, the utility model is provided with a first substrate fastening hole matched with the first upper fastener 4 on the left substrate 311 of the fixed substrate 31, and the position of the first substrate fastening hole corresponds to the position of the first upper clamp fixing hole at the upper end of the first detection clamp 11, and the right substrate 312 of the fixed substrate 31 is provided with a second substrate fastening hole matched with the second upper fastener 5, and the position of the second substrate fastening hole corresponds to the position of the second upper clamp fixing hole at the upper end of the second detection clamp 12, and the first upper elastic fixing hole and the second upper elastic fixing hole are provided at both ends of the sensing elastic member 21, and the position of the first upper elastic fixing hole corresponds to the position of the first upper clamp fixing hole at the upper end of the first detection clamp 11, and the second upper elastic fixing hole The position of the fixing hole corresponds to the position of the second upper clamp fixing hole at the upper end of the second detection clamp 12. The first upper fastener 4 passes through the first substrate fastening hole of the left substrate 311, the first upper elastic fixing hole of the sensing elastic member 21, and the first upper clamp fixing hole of the first detection clamp 11 from top to bottom in sequence so as to fix the left substrate 311 and the sensing elastic member 21 to the upper end of the first detection clamp 11. The second upper fastener 5 passes through the second substrate fastening hole of the right substrate 312, the second upper elastic fixing hole of the sensing elastic member 21, and the second upper clamp fixing hole of the second detection clamp 12 from top to bottom in sequence so as to fix the right substrate 312 and the other end of the sensing elastic member 21 to the upper end of the second detection clamp 12. A first lower elastic fixing hole and a second lower elastic fixing hole are provided at both ends of the sensing lower elastic member 22. The position of the first lower elastic fixing hole corresponds to the position of the first lower clamp fixing hole at the lower end of the first detection clamp 11, and the position of the second lower elastic fixing hole corresponds to the position of the second lower clamp fixing hole at the lower end of the second detection clamp 11. The first lower fastener 6 passes through the first lower elastic fixing hole of the sensing lower elastic member 22 and the first lower clamp fixing hole at the lower end of the first detection clamp 11 from bottom to top in sequence to fix one end of the sensing lower elastic member 22 to the lower end of the first detection clamp 11, and the second lower fastener 7 passes through the second lower elastic fixing hole of the sensing lower elastic member 22 and the second lower clamp fixing hole at the lower end of the second detection clamp 12 in sequence from bottom to top to fix the other end of the sensing lower elastic member 22 to the lower end of the second detection clamp 12.
[0044] like Fig. 9 As shown, the first long-gauge fiber grating 321 of the utility model includes a first optical fiber, a plurality of first optical fiber gratings, and two groups of first pigtails, the plurality of first optical fiber gratings are equidistantly distributed in the middle area of the first optical fiber, and the two groups of first pigtails are distributed at both ends of the first optical fiber, and the second long-gauge fiber grating 322 includes a second optical fiber, a plurality of second optical fiber gratings, and two groups of second pigtails, the plurality of second optical fiber gratings are equidistantly distributed in the middle area of the second optical fiber, and the two groups of second pigtails are distributed at both ends of the second optical fiber.
[0045] The specific operation process of the pipeline 8 detection device of the utility model to monitor the internal pressure of the pipeline 8 is as follows:
[0046] Step 1) Pipeline 8 pressure measurement: First, measure the inner diameter pressure change of pipeline 8, apply pressure p to pipeline 8 through the pressure chamber to make pipeline 8 expand evenly under the action of internal pressure p, and calculate the inner diameter change of pipeline 8, the inner diameter change is:
[0047] Wherein, d is the inner diameter of the pipe 8; υ and E are the Poisson's ratio and elastic modulus of the material of the pipe 8 respectively; δ is the wall thickness of the pipe 8;
[0048] Step 2) Measurement of the long gauge length double grating structure 32: An equation relationship is established between the change in the internal diameter of the pipeline 8 and the central wavelength offset measured by stretching the long gauge length double grating structure 32. When the inner diameter of the pipeline 8 changes, the sensing and measuring structure 3 acts on the sensing elastic structure 2, and the left and right first detection clamps 11 and the second detection clamps 12 of the sensing and measuring structure 3 can move with the deformation of the pipeline 8. According to the displacement coordination relationship, the relative displacement ΔL of the first detection clamp 11 and the second detection clamp 12 and the change in the inner diameter of the pipeline 8 Δd have the following equation relationship: Δd=ΔL;
[0049] Under the relative movement of the first detection clamp 11 and the second detection clamp 12, the first long-gauge fiber Bragg grating 321 and the second long-gauge fiber Bragg grating 322 of the long-gauge dual-grating structure 32 will be stretched, and the central wavelength offsets Δλ1 and Δλ2 of the first long-gauge fiber Bragg grating 321 and the second long-gauge fiber Bragg grating 322 can be expressed as:
[0050]
[0051] In the expression, λ1 and λ2 are the initial center wavelengths of the first long gauge fiber Bragg grating 321 and the second long gauge fiber Bragg grating 322, respectively, and |K|≠0, L1 and L2 are the initial lengths of the first long gauge fiber Bragg grating 321 and the second long gauge fiber Bragg grating 322, respectively, and p e is the elastic-optic coefficient of the fiber Bragg grating, α is the thermal expansion coefficient of the fiber Bragg grating, ξ is the thermo-optic coefficient of the fiber Bragg grating, and ΔT is the change in ambient temperature;
[0052] Combining the above expressions (1) and (2), the functional relationship between the internal pressure p of the pipeline 8 and the central wavelength offset of the first long gauge fiber Bragg grating 321 and the second long gauge fiber Bragg grating 322 can be expressed as:
[0053]
[0054] The pipeline 8 detection device of the utility model establishes an equation relationship between the change in the internal diameter of the pipeline 8 and the center wavelength offset measured by the stretching of the long gauge double grating structure 32. Under the relative movement of the first detection clamp 11 and the second detection clamp 12, the first long gauge fiber grating 321 and the second long gauge fiber grating 322 of the long gauge double grating structure 32 will be stretched. The functional relationship between the internal pressure p of the pipeline 8 and the center wavelength offset of the first long gauge fiber grating 321 and the second long gauge fiber grating 322 is obtained by stretching calculation, and the first detection clamp 11 and the second detection clamp 12 directly convert the change in the diameter of the pipeline 8 into the axial displacement of the two long gauge fiber gratings. The pipeline detection device of the utility model has a simple measurement method for measuring the internal pressure of the pipeline 8. By adopting the design of the long gauge double grating structure 32, the influence of temperature change can be eliminated, and the error caused by the structural asymmetry caused by factors such as processing can be further eliminated.
[0055] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.
Claims
1. A pipeline detection device based on a long gauge length double grating structure, characterized in that: The pipeline detection device includes a detection fixture for clamping pipeline detection, two groups of sensing elastic structures, and a sensing measurement structure. The upper and lower ends of the detection fixture are respectively provided with a first slot and a second slot. The two groups of sensing elastic structures include an upper sensing elastic member and a lower sensing elastic member. The upper sensing elastic member and the lower sensing elastic member are symmetrically distributed in the upper and lower directions. The upper sensing elastic member and the lower sensing elastic member are respectively installed at the first slot and the second slot at the upper and lower ends of the detection fixture. The sensing measurement structure is installed at the upper end of the upper sensing elastic member and is located at the first slot of the detection fixture. The sensing measurement structure includes a long-gauge double grating structure and a fixed substrate. The long-gauge double grating structure is installed on the fixed substrate.
2. The pipeline detection device based on the long gauge length double grating structure according to claim 1 is characterized in that: The long gauge dual grating structure includes a first long gauge fiber grating and a second long gauge fiber grating, the first long gauge fiber grating and the second long gauge fiber grating are spaced apart and arranged in parallel, and the first long gauge fiber grating and the second long gauge fiber grating are fixed on a fixed substrate along the length direction of the fixed substrate.
3. The pipeline detection device based on the long gauge length double grating structure according to claim 2 is characterized in that: The fixed substrate includes a left substrate and a right substrate, and the left substrate and the right substrate are symmetrically distributed on both sides of the upper end of the elastic member on the sensor. The two ends of the first long-gauge fiber grating and the second long-gauge fiber grating are respectively fixed on the left substrate and the right substrate and are located at the first groove at the upper end of the detection fixture. The distance between the left substrate and the right substrate forms a fiber accommodating hollow area.
4. The pipeline detection device based on the long gauge length double grating structure according to claim 1 is characterized in that: The detection clamp comprises a first detection clamp and a second detection clamp, the first detection clamp and the second detection clamp are symmetrically spaced, the first slot is formed by the distance between the upper end of the first detection clamp and the upper end of the second detection clamp, the second slot is formed by the distance between the lower end of the first detection clamp and the lower end of the second detection clamp, the distance between the first detection clamp and the second detection clamp forms a channel for clamping the pipeline, the pipeline detection device comprises a first upper fastener, a second upper fastener, a first lower fastener, and a second lower fastener, the upper and lower ends of the first detection clamp are respectively provided with a first upper clamp fixing hole and a first lower clamp fixing hole, the upper and lower ends of the second detection clamp are respectively provided with a second upper clamp fixing hole and a second lower caliper fixing hole, the first upper fastener and the second upper fastener are respectively located at the first upper clamp fixing hole of the first detection clamp and the second upper clamp fixing hole of the second detection clamp, the first lower fastener and the second lower fastener are respectively located at the first lower clamp fixing hole of the first detection clamp and the second lower clamp fixing hole of the second detection clamp.
5. The pipeline detection device based on the long gauge length double grating structure according to claim 4 is characterized in that: A first arc-shaped contact surface matching the outer shape of the pipeline is formed on the inner side of the first detection clamp, and a second arc-shaped contact surface matching the outer shape of the pipeline is formed on the inner side of the second detection clamp.
6. The pipeline detection device based on the long gauge length double grating structure according to claim 3 is characterized in that: The right end of the left substrate extends rightward to form a left extended fixing arm, the lower end of the left substrate extends downward to form a left extended fixing portion, the left end of the right substrate extends leftward to form a right extended fixing arm, the lower end of the right substrate extends downward to form a right extended fixing portion, the two ends of the first long gauge fiber Bragg grating are respectively fixed to the left extended fixing arm of the left substrate and the right extended fixing arm of the right substrate to achieve the fixation of the first long gauge fiber Bragg grating to the left and right substrates, and the two ends of the second long gauge fiber Bragg grating are respectively fixed to the left extended fixing portion of the left substrate and the right extended fixing portion of the right substrate to achieve the fixation of the second long gauge fiber Bragg grating to the left and right substrates.
7. The pipeline detection device based on a long gauge length double grating structure according to claim 1 is characterized in that: The left substrate of the fixed substrate is provided with a first substrate fastening hole matched with the first upper fastener, and the position of the first substrate fastening hole corresponds to the position of the first upper clamp fixing hole at the upper end of the first detection clamp, and the right substrate of the fixed substrate is provided with a second substrate fastening hole matched with the second upper fastener, and the two ends of the sensing elastic member are provided with a first upper elastic fixing hole and a second upper elastic fixing hole, and the first upper fastener passes through the first substrate fastening hole of the left substrate, the first upper elastic fixing hole of the sensing elastic member, and the first upper clamp fixing hole of the first detection clamp from top to bottom in sequence so as to fix the left substrate and the sensing elastic member to the upper end of the first detection clamp, and the second upper fastener passes through the second substrate fastening hole of the right substrate, the second upper elastic fixing hole of the sensing elastic member, and the second upper clamp fixing hole of the second detection clamp in sequence from top to bottom so as to fix the right substrate and the other end of the sensing elastic member to the upper end of the second detection clamp.
8. The pipeline detection device based on a long gauge length double grating structure according to claim 4 is characterized in that: A first lower elastic fixing hole and a second lower elastic fixing hole are provided at both ends of the lower elastic member of the sensor. The first lower fastener passes through the first lower elastic fixing hole of the lower elastic member of the sensor and the first lower clamp fixing hole at the lower end of the first detection clamp from bottom to top in sequence to fix one end of the lower elastic member of the sensor to the lower end of the first detection clamp. The second lower fastener passes through the second lower elastic fixing hole of the lower elastic member of the sensor and the second lower clamp fixing hole at the lower end of the second detection clamp in sequence from bottom to top to fix the other end of the lower elastic member of the sensor to the lower end of the second detection clamp.
9. The pipeline detection device based on a long gauge length double grating structure according to claim 2 is characterized in that: The first long-gauge fiber grating includes a first optical fiber, a plurality of first optical fiber gratings, and two groups of first pigtails, wherein the plurality of first optical fiber gratings are equidistantly distributed in the middle region of the first optical fiber, and the two groups of first pigtails are distributed at both ends of the first optical fiber. The second long-gauge fiber grating includes a second optical fiber, a plurality of second optical fiber gratings, and two groups of second pigtails, wherein the plurality of second optical fiber gratings are equidistantly distributed in the middle region of the second optical fiber, and the two groups of second pigtails are distributed at both ends of the second optical fiber.