Negative pressure pipeline leakage point detection and targeted repair system and method

Abstract

The invention discloses a negative pressure pipeline leakage point detection and targeted repair system and method, and the method achieves the confirmation of a pipeline leakage point through a detection end, and achieves the repair of the pipeline leakage point through a repair end. The detection end comprises a distributed optical fiber, an unmanned aerial vehicle and a control platform; through distributed optical fibers laid along a pipeline, pipeline vibration and temperature abnormity are monitored in real time, a leakage area is preliminarily positioned, then infrared scanning is performed on a suspicious area through an unmanned aerial vehicle carrying a high-precision thermal infrared imager, a temperature field distribution diagram is generated and uploaded to a control platform, and the control platform outputs leakage point coordinates through a data fusion algorithm; the repairing end comprises self-repairing gel and a magnetic control robot; the small cracks with the width smaller than 1 mm are externally sprayed with self-repairing gel, and laser curing is conducted after the cracks are sucked in through negative pressure; for large cracks with the width larger than or equal to 1 mm, the magnetic control robot is put into the pipeline, resin is sprayed to the inner wall of the pipeline, and ultraviolet curing is conducted. The system and the method can remarkably improve the maintenance efficiency of the negative pressure pipeline.

Description

Technical Field

[0001] The present invention relates to a negative pressure pipeline leakage point detection and targeted repair system and method, belonging to the technical field of pipeline safety maintenance. It can be widely applied to pipeline maintenance in fields such as underground gas drainage in coal mines, petroleum, natural gas, and chemical engineering. Background Art

[0002] Currently, the leakage detection and repair of negative pressure pipelines (with internal pressure lower than atmospheric pressure) face the following technical difficulties:

[0003] Weak signal: The traditional pressure decay method fails in the negative pressure environment, and the low leakage flow rate makes it difficult to capture acoustic and thermodynamic signals.

[0004] Difficult positioning: It is difficult to achieve high-precision leakage positioning for long-distance or underground pipelines.

[0005] Repair interference: In the negative pressure environment, the repair material is easily sucked into the pipeline, making it difficult to target and fill the cracks. Existing technologies such as ultrasonic detection or tracer gas method have problems such as insufficient sensitivity, high cost, and low repair efficiency.

[0006] In terms of repair materials: Most repair materials (such as epoxy resin) become brittle at low temperatures and soften at high temperatures under extreme temperatures and require high-temperature baking (such as 120°C × 2 hours), which is difficult to implement in the wild or in scenarios without power supply. Summary of the Invention

[0007] The purpose of the present invention is to provide a negative pressure pipeline leakage point detection and targeted repair system and method. This system and method can significantly improve the maintenance efficiency of negative pressure pipelines.

[0008] The technical solution of the present invention: A negative pressure pipeline leakage point detection and targeted repair system includes a detection end and a repair end. The leakage point of the pipeline is confirmed through the detection end, and the leakage point of the pipeline is repaired through the repair end;

[0009] The detection end includes a distributed optical fiber, an unmanned aerial vehicle (UAV), and a control platform; through the distributed optical fiber laid along the pipeline, the pipeline vibration and temperature anomalies are monitored in real time to initially locate the leakage area. Then, the UAV equipped with a high-precision infrared thermal imager performs an infrared scan on the suspicious area, generates a temperature field distribution map and uploads it to the control platform, and the control platform outputs the leakage point coordinates through a data fusion algorithm;

[0010] The repair end includes a self-healing gel and a magnetically controlled robot; for small cracks with a width < 1 mm, the self-healing gel is externally sprayed, and after being sucked into the cracks by negative pressure, it is laser-cured; for large cracks with a width ≥ 1 mm, the magnetically controlled robot is put into the pipeline, and resin is sprayed on the inner wall of the pipeline and ultraviolet-cured.

[0011] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the self-healing gel contains the following materials by mass percentage: terminal isocyanate polyurethane prepolymer 50-60%, nano-silica 5-10%, photothermal-responsive gold nanorods 1-3%, epoxy diluent AGE 10-15%, photoinitiator TPO-L 0.5-1%, surfactant 0.5-1%, and the balance is ethyl acetate solvent.

[0012] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the preparation process of the self-healing gel is as follows:

[0013] S1 Prepolymer synthesis: Polyether polyol with a molecular weight of 2000 and isophorone diisocyanate IPDI are mixed at an NCO / OH molar ratio of 2:1 and reacted at 70°C for 3 hours to obtain a terminal isocyanate polyurethane prepolymer;

[0014] S2 Nano-dispersion: Nano-silica and epoxy diluent are ultrasonically dispersed to form a uniform suspension;

[0015] S3 Functional doping: Photothermal-responsive gold nanorods and photoinitiator are added to the terminal isocyanate polyurethane prepolymer, and then the suspension is added, and magnetic stirring is carried out for 2 hours under dark conditions;

[0016] S4 Rheological adjustment: Surfactant and solvent are added, and the viscosity is monitored by a rotational viscometer;

[0017] S5 Encapsulation and storage: It is filled with nitrogen and sealed in a brown glass bottle, refrigerated in the dark, and the shelf life is 6 months.

[0018] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, in step S2, the particle size of nano-silica is 20 nm; the ultrasonic dispersion power is 300 W and the time is 30 minutes; in step S3, the aspect ratio of the gold nanorods is 4:1, the diameter is 10–20 nm, the concentration is 1 mg / mL, and the rotation speed during magnetic stirring is 500 rpm.

[0019] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the viscosity of the self-healing gel is 20–50 mPa·s, and the surface tension ≤25 mN / m.

[0020] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the magnetic control robot is equipped with an ultraviolet curing resin spray head and an image recognition module, uses a permanent magnet wheeled chassis, the adsorption force ≥50 N, the moving speed is 0.1–0.5 m / s, and the scattered light sources are a red light source with a wavelength of 700–750 nm and a violet light source with a wavelength of 315–400 nm.

[0021] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the resolution of the high-precision infrared thermal imager is ≤0.1°C, and the local low-temperature area with a temperature difference ≥1.5°C caused by gas inhalation at the leakage point is captured by a drone equipped with the high-precision infrared thermal imager.

[0022] In the aforementioned negative pressure pipeline leakage point detection and targeted repair system, the control platform uses a lock-in amplifier and a deep learning algorithm to filter environmental noise.

[0023] A method for detecting and targeted repairing leakage points of a negative pressure pipeline, which is realized based on the aforementioned negative pressure pipeline leakage point detection and targeted repair system, includes the following steps:

[0024] (1) Fusing a distributed optical fiber and a drone equipped with an infrared thermal imager to locate the leakage point;

[0025] (2) Selecting a negative pressure suction self-repairing gel or a magnetically controlled robot lining repair according to the crack size;

[0026] (3) Curing the repair material by photothermal or ultraviolet triggering.

[0027] The beneficial effects of the present invention: Compared with the prior art, the present invention has obtained the following beneficial technical effects after adopting the above technical solutions:

[0028] High efficiency and precision: The multi-modal detection technology controls the positioning error within 0.5 meters;

[0029] Adaptive repair: Matching the best repair plan according to different crack sizes, and the repair success rate >95%;

[0030] Low environmental interference: There is no need to shut down the pipeline, and it is applicable to complex working conditions. Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of the system of the present invention. Detailed Embodiments

[0032] The following further illustrates the present invention in conjunction with the drawings and embodiments, but it shall not be used as a basis for limiting the present invention.

[0033] Embodiment of the present invention: A negative pressure pipeline leakage point detection and targeted repair system includes a detection end and a repair end. The leakage point of the pipeline is confirmed through the detection end, and the leakage point of the pipeline is repaired through the repair end;

[0034] The detection end includes a distributed optical fiber, an unmanned aerial vehicle (UAV), and a control platform. Through the distributed optical fiber laid along the pipeline, the pipeline vibration and temperature anomalies are monitored in real time to preliminarily locate the leakage area. Then, the UAV equipped with a high-precision infrared thermal imager scans the suspicious area for infrared, generates a temperature field distribution map and uploads it to the control platform. The control platform outputs the leakage point coordinates through a data fusion algorithm.

[0035] The repair end includes a self-healing gel and a magnetically controlled robot. For small cracks with a width < 1 mm, the self-healing gel is externally sprayed, and after being sucked into the cracks by negative pressure, it is laser-cured. For large cracks with a width ≥ 1 mm, the magnetically controlled robot is put into the pipeline to spray resin on the inner wall of the pipeline and then ultraviolet-cured.

[0036] The negative pressure pipeline leakage point detection and targeted repair system of the present invention includes: a multi-modal detection module: a collaborative detection technology based on distributed optical fiber sensing and UAV infrared thermal imaging; a targeted repair module: combining a negative pressure suction type self-healing gel and a pipeline magnetically controlled robot lining repair technology; an intelligent control platform: realizing the automatic control of the leakage location and repair process through a data fusion algorithm.

[0037] Detection end: Fiber-infrared fusion detection: Lay a distributed optical fiber (DAS / DTS) along the pipeline to monitor vibration and temperature anomalies in real time and preliminarily locate the leakage area; deploy a UAV equipped with a high-precision infrared thermal imager (resolution ≤ 0.1°C) in the suspicious area to capture the local low-temperature area (temperature difference ≥ 1.5°C) caused by gas inhalation at the leakage point. Adaptive signal enhancement: Use a lock-in amplifier and a deep learning algorithm (CNN model) to filter environmental noise and improve the signal-to-noise ratio > 20 dB.

[0038] Repair end: Negative pressure-driven self-healing gel: Use a low-viscosity (< 50 mPa·s) polyurethane / nano-silica composite gel. Composition and functions of the composite gel: Terminal isocyanate polyurethane prepolymer matrix material, providing flexibility and mechanical strength, with isocyanate end groups (NCO content 6 - 8%); nano-silica enhances mechanical properties (tensile strength ≥ 5 MPa) and regulates rheology (shear thinning behavior); photothermal-responsive gold nanorod near-infrared light absorber (absorption peak wavelength is 700 - 750 nm), with a photothermal conversion efficiency ≥ 80%, triggering local curing (5 - 10 seconds); epoxy diluent (AGE) reduces viscosity (dynamic viscosity < 50 mPa·s) and improves negative pressure suction permeability; photoinitiator (TPO-L) is a UV / visible light curing trigger (response wavelength 315 - 400 nm) to ensure deep curing efficiency; surfactant fluorocarbon surfactant (such as Capstone FS-30) reduces the surface tension to ≤ 25 mN / m and quickly penetrates into the cracks through capillary action; solvent (ethyl acetate) regulates fluidity and leaves no residue after volatilization (boiling point 77°C).

[0039] Magnetically Controlled Repair Robot: Equipped with an ultraviolet curing resin spray head and an image recognition module, it uses a permanent magnet wheeled chassis with an adsorption force ≥ 50 N, a moving speed of 0.1–0.5 m / s, and the emitted light sources are a red light source with a wavelength of 700–750 nm and a violet light source with a wavelength of 315–400 nm. The magnetically controlled robot adsorbs and moves on the inner wall of the metal pipeline, carries a two-component ultraviolet curing resin spray head, locates cracks through image recognition (YOLOv5 model) and then sprays the repair material, and the ultraviolet LED (365 nm) cures it immediately.

[0040] The self-healing gel contains the following materials by mass percentage: terminal isocyanate polyurethane prepolymer 50 - 60%, nano-silica 5 - 10%, photo-thermal responsive gold nanorods 1 - 3%, epoxy diluent AGE 10 - 15%, photoinitiator TPO-L 0.5 - 1%, surfactant 0.5 - 1%, and the balance is ethyl acetate solvent.

[0041] The preparation process of the self-healing gel is as follows:

[0042] S1 Prepolymer Synthesis: Polyether polyol with a molecular weight of 2000 and isophorone diisocyanate IPDI are mixed at an NCO / OH molar ratio of 2:1 and reacted at 70°C for 3 hours to obtain the terminal isocyanate polyurethane prepolymer;

[0043] S2 Nano-dispersion: Nano-silica (particle size 20 nm) and epoxy diluent are ultrasonically dispersed (power 300 W, 30 minutes) to form a uniform suspension;

[0044] S3 Functional Doping: Add photo-thermal responsive gold nanorods (aspect ratio 4:1, concentration 1 mg / mL) and photoinitiator to the terminal isocyanate polyurethane prepolymer, and then add the suspension, and magnetically stir for 2 hours (rotation speed 500 rpm) under dark conditions;

[0045] S4 Rheology Adjustment: Add surfactant and solvent, and monitor the viscosity through a rotational viscometer;

[0046] S5 Encapsulation and Storage: Fill with nitrogen, seal in a brown glass bottle, store in the dark and refrigerate (4°C), and the shelf life is 6 months.

[0047] The viscosity of the self-healing gel is 20–50 mPa·s, and the surface tension ≤ 25 mN / m. It contains gold nanorods (diameter 10–20 nm) as the photo-thermal conversion agent.

[0048] System Working Process

[0049] Leak Detection: The distributed optical fiber sensing network detects abnormal vibration signals and marks the coordinates of the suspicious area;

[0050] The drone conducts infrared scanning on the area, generates a temperature field distribution map and uploads it to the control platform; the platform outputs the coordinates of the leakage point through a data fusion algorithm (weighted Kalman filter), and the positioning accuracy is ≤ 0.5 meters.

[0051] Targeted repair: For small cracks (width < 1 mm): externally spray self-healing gel, use negative pressure to suck it into the crack and then cure it with laser; for large cracks (width ≥ 1 mm): deploy a magnetically controlled robot into the pipeline, spray resin on the inner wall and cure it with ultraviolet light.

[0052] Specific example 1: Repair of gas pipeline leakage

[0053] Detection stage:

[0054] Single-mode optical fibers (DAS mode) are laid in a 10-km pipeline, and 3 vibration anomaly areas are detected;

[0055] Infrared scanning by the drone shows that the temperature in one area is 2.3 °C lower than that of the surrounding area, which is determined to be the leakage point (coordinate X = 2350 m).

[0056] Preparation of self-healing gel:

[0057] S1 Prepolymer synthesis: Mix polyether polyol with a molecular weight of 2000 and isophorone diisocyanate IPDI at an NCO / OH molar ratio of 2:1, react at 70 °C for 3 hours to obtain a terminal isocyanate polyurethane prepolymer; take 55 parts for standby.

[0058] S2 Nanodispersion: Ultrasonically disperse 8 parts of nanosilica (particle size 20 nm) and 12 parts of epoxy diluent (power 300 W, 30 minutes) to form a uniform suspension;

[0059] S3 Functional doping: Add 2 parts of photothermal-responsive gold nanorods (aspect ratio 4:1, concentration 1 mg / mL) and 0.5 part of photoinitiator TPO-L to 55 parts of the terminal isocyanate polyurethane prepolymer, and then add the suspension, and magnetically stir for 2 hours (rotation speed 500 rpm) under dark conditions;

[0060] S4 Rheology adjustment: Add 0.5 part of surfactant and 22 parts of ethyl acetate solvent, and monitor the viscosity with a rotational viscometer to be 45 mPa·s)

[0061] S5 Encapsulation and storage: Fill with nitrogen and seal in a brown glass bottle, store in the dark and refrigerate (4 °C).

[0062] Repair stage:

[0063] The crack width is 0.8 mm, externally spray self-healing gel (viscosity 45 mPa·s), suck it in with negative pressure and irradiate it with laser at 5 W / cm² for 8 seconds to cure;

[0064] After repair, the airtightness test shows that the leakage rate has decreased by 99.6%.

[0065] Specific Example 2: Repair of Chemical Negative Pressure Pipeline Robot

[0066] Detection stage:

[0067] Lay a single-mode optical fiber (DAS mode) in a 1-km pipeline, and 1 vibration abnormal area is detected;

[0068] The infrared scan by the drone shows that the temperature at one place is 2°C lower than that of the surrounding area, which is determined as the leakage point (coordinate X = 238 m).

[0069] Self-healing gel preparation:

[0070] S1 Prepolymer synthesis: Mix polyether polyol with a molecular weight of 2000 and isophorone diisocyanate IPDI at an NCO / OH molar ratio of 2:1, and react at 70°C for 3 hours to obtain an isocyanate-terminated polyurethane prepolymer; take 60 parts for standby.

[0071] S2 Nanodispersion: Ultrasonically disperse 10 parts of nano-silica (particle size 20 nm) and 15 parts of epoxy diluent (power 300 W, 30 minutes) to form a uniform suspension;

[0072] S3 Functional doping: Add 2 parts of photothermal-responsive gold nanorods (aspect ratio 4:1, concentration 1 mg / mL) and 0.5 part of photoinitiator TPO-L to 60 parts of the isocyanate-terminated polyurethane prepolymer, and then add the suspension, and magnetically stir for 2 hours (rotation speed 500 rpm) under dark conditions;

[0073] S4 Rheological adjustment: Add 0.5 part of surfactant and 12 parts of ethyl acetate solvent, and monitor the viscosity with a rotational viscometer (viscosity is 40 mPa·s);

[0074] S5 Encapsulation and storage: Fill with nitrogen and seal in a brown glass bottle, and store in the dark and refrigerate (4°C).

[0075] Repair stage:

[0076] The crack width is 1.2 mm. Place the magnetically controlled robot into the pipeline. After moving to the target position, spray the self-healing gel (viscosity 40 mPa·s);

[0077] After repair, the airtightness test shows that the leakage rate has decreased by 99.5%. The pipeline pressure resistance test after repair passes the ISO 14692 standard.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A negative pressure pipeline leakage point detection and targeted repair system, characterized in that: It includes a detection end and a repair end. The detection end is used to confirm the pipeline leakage point, and the repair end is used to repair the pipeline leakage point. The detection end includes a distributed optical fiber, a drone and a control platform. Through the distributed optical fiber laid along the pipeline, the pipeline vibration and temperature anomalies are monitored in real time to initially locate the leakage area. Then, the drone equipped with a high-precision infrared thermal imager conducts an infrared scan of the suspicious area, generates a temperature field distribution map and uploads it to the control platform. The control platform outputs the leakage point coordinates through a data fusion algorithm. The repair end includes a self-healing gel and a magnetically controlled robot. For small cracks with a width < 1 mm, the self-healing gel is externally sprayed, sucked into the cracks by negative pressure and then laser-cured. For large cracks with a width ≥ 1 mm, a magnetically controlled robot is put into the pipeline to spray resin on the inner wall of the pipeline and then ultraviolet-cured.

2. The leak point detection and targeted repair system for a negative pressure pipeline according to claim 1, characterized in that: The self-healing gel contains the following materials by mass percentage: terminal isocyanate polyurethane prepolymer 50 - 60%, nano-silica 5 - 10%, photo-thermal responsive gold nanorods 1 - 3%, epoxy diluent AGE 10 - 15%, photoinitiator TPO-L 0.5 - 1%, surfactant 0.5 - 1%, and the balance is ethyl acetate solvent.

3. The negative pressure pipeline leakage point detection and targeted repair system according to claim 2, characterized in that: The preparation process of the self-healing gel is as follows: S1 Prepolymer synthesis: Polyether polyol with a molecular weight of 2000 and isophorone diisocyanate IPDI are mixed at an NCO / OH molar ratio of 2:1 and reacted at 70°C for 3 hours to obtain a terminal isocyanate polyurethane prepolymer. S2 Nano-dispersion: Nano-silica and epoxy diluent are ultrasonically dispersed to form a uniform suspension. S3 Functional doping: Photo-thermal responsive gold nanorods and a photoinitiator are added to the terminal isocyanate polyurethane prepolymer, and then the suspension is added, and magnetic stirring is carried out for 2 hours under dark conditions. S4 Rheological adjustment: A surfactant and a solvent are added, and the viscosity is monitored by a rotational viscometer. S5 Encapsulation and storage: It is sealed with nitrogen in a brown glass bottle, stored in the dark and refrigerated, and the shelf life is 6 months.

4. The leak point detection and targeted repair system for a negative pressure pipeline according to claim 3, wherein: In the step S2, the particle size of nano-silica is 20 nm; the ultrasonic dispersion power is 300 W and the time is 30 minutes; in the step S3, the aspect ratio of the gold nanorods is 4:1, the diameter is 10–20 nm, the concentration is 1 mg / mL, and the rotation speed during magnetic stirring is 500 rpm.

5. The leak point detection and targeted repair system for a negative pressure pipeline according to claim 3, wherein: The viscosity of the self-healing gel is 20–50 mPa·s, and the surface tension ≤ 25 mN / m.

6. The negative pressure pipeline leakage point detection and targeted repair system according to claim 1, wherein: The magnetically controlled robot is equipped with an ultraviolet-curing resin spray head and an image recognition module, uses a permanent magnet wheeled chassis, the adsorption force ≥ 50 N, the moving speed is 0.1–0.5 m / s, and the emitted light sources are a red light source with a wavelength of 700–750 nm and a violet light source with a wavelength of 315–400 nm.

7. A negative pressure pipeline leakage point detection and targeted repair system according to claim 1, characterized in that: The resolution of the high-precision infrared thermal imager ≤ 0.1°C, and the drone equipped with the high-precision infrared thermal imager captures the local low-temperature area with a temperature difference ≥ 1.5°C caused by gas inhalation at the leakage point.

8. A negative pressure pipeline leakage point detection and targeted repair system according to claim 1, characterized in that: The control platform uses a lock-in amplifier and a deep learning algorithm to filter environmental noise.

9. A method for detecting leakage points and targeted repair of a negative pressure pipeline, characterized in that: This method is realized based on the negative pressure pipeline leakage point detection and targeted repair system described in any one of claims 1-8, and includes the following steps: (1) Fuse distributed optical fiber with a drone equipped with an infrared thermal imager to locate the leakage point; (2) Select negative pressure suction self-repairing gel or magnetic control robot lining repair according to the crack size; (3) Cure the repair material by photothermal or ultraviolet triggering.

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