Point-line combined fiber optic grating monitoring and early warning system and method for non-metallic pressure tubes

Abstract

This invention discloses a point-line combined fiber optic grating monitoring and early warning system and method for non-metallic pressure pipes. It combines point and line monitoring modules to achieve real-time monitoring of multiple parameters, including pipe strain, temperature, and vibration. Based on this, it simulates various events such as excavation, leakage, and bending to construct a signal sample library. This signal sample library and intelligent recognition algorithm are deployed at the edge and can be fed back to a local early warning device for local monitoring and early warning. Alternatively, monitoring data or event information can be wirelessly transmitted to a monitoring and early warning platform. The monitoring and early warning platform can be integrated with local video surveillance and personnel inspections for comprehensive judgment. Furthermore, it can automatically send the handling results to the automatic centralized control execution terminal of the pipeline system for early intervention or control the local early warning device for local early warning.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic grating sensor technology, specifically relating to a point-line combination fiber optic grating monitoring and early warning system and method for non-metallic pressure tubes. Background Technology

[0002] According to statistics from the State Administration for Market Regulation, the total length of non-metallic gas pipelines in urban areas nationwide that fall under the category of pressure pipelines has reached 416,000 km, accounting for 74.7% of the total mileage of gas pressure pipelines. With the widespread recognition of the superior corrosion resistance and impermeability of new non-metallic pipelines, they have replaced steel and cast iron pipes in medium and low-pressure gas pipeline networks. In recent years, pipeline aging, construction damage, and external forces such as foundation settlement and vehicle traffic have led to frequent pipeline leaks and explosions. Urban areas have large populations and dense buildings; if pipeline leaks are not detected in time, they can lead to serious accidents such as fires and explosions, causing not only huge casualties and property losses but also severe environmental pollution.

[0003] Currently, the domestic gas industry generally adopts manual and vehicle-mounted inspection methods, monitoring the operation of external pipelines at fixed intervals and using leak detection tools to ensure the normal operating condition of the pipeline network. While this type of inspection is suitable for China's national conditions, it has drawbacks such as the inability to achieve real-time monitoring and the inability to promptly grasp emergencies outside the monitoring cycle. In terms of intelligent monitoring, non-metallic gas pipelines have basically achieved monitoring of flow and pressure, but cannot comprehensively monitor the operational status of the pipeline.

[0004] Distributed fiber optic early warning technology is widely used in the field of long-distance oil and gas pipelines. It utilizes accompanying optical cables laid in the same trench as the pipeline to sense vibration signals along the pipeline route, enabling early warning of damage from third parties. Currently, two generations of fiber optic early warning technology have been developed: the first generation is DVS (conventional Rayleigh scattering, detecting changes in light intensity), and the second generation is DAS (phase-sensitive optical time-domain reflectometry). However, because Rayleigh, Brillouin, and Raman technologies use backscattered signals, the scattering intensity is relatively low, resulting in weak signals. When used in non-metallic gas pipelines, they are ineffective in environments with limited underground space and severe signal interference, such as urban areas. Domestically, Zhejiang Baishitong attempted to use optical cables running inside in-service pipelines, but the optical fibers could not be fixed to the pipe wall, making deformation and temperature monitoring impossible.

[0005] Long-life, high-stability, multi-parameter point-based monitoring and high signal-to-noise ratio intelligent non-metallic composite pipe line-based monitoring are effective means and research hotspots for solving the damage to urban gas PE pipelines caused by third-party activities and geological subsidence. Unlike long-distance pipelines, in-service gas non-metallic pipelines did not have optical cables laid in the same trench during construction. Domestic attempts at internal optical cable technology for in-service pipelines have encountered problems such as the inability to fix the optical fiber to the pipe wall, making deformation and temperature monitoring impossible. Currently, the commonly used fixed-point monitoring technologies both domestically and internationally, including leak, video, and displacement monitoring methods, suffer from isolated points and independent parameters, making them unsuitable for complex and harsh environments, and exhibiting high false alarm rates in complex urban underground environments with frequent human activity. For intelligent non-metallic composite pipes, PE-based composite pipes based on optical fiber backscattering developed by companies such as SmartPipe (USA) and Baoji Steel Pipe suffer from problems such as high joint signal loss and cross-interference of multi-parameter signals from optical fibers. The overlapping periodic grating array developed by Beijing Jiaotong University helps solve the problems of multi-parameter cross-sensitivity and long-distance loss. Therefore, there is an urgent need to develop a point-line combined fiber optic grating monitoring and early warning system for intelligent non-metallic pressure tubes. Summary of the Invention

[0006] This invention provides a point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes to solve the problems of isolated points and independent parameters in traditional fixed-point monitoring, which cannot adapt to complex and harsh environments and has a high false alarm rate in complex urban underground environments with frequent human activity. It also addresses the challenges of multi-parameter cross-sensitivity and long-distance loss in intelligent non-metallic composite tubes due to fiber backscattering in PE-based composite tubes. Ultimately, it achieves real-time, online, efficient, and high-precision monitoring of non-metallic pressure tubes across the entire area.

[0007] To solve the above problems, the technical solution provided by the present invention is as follows:

[0008] This invention provides a point-to-line combined fiber optic grating monitoring and early warning system for non-metallic pressure pipes, comprising a point monitoring module (1), a line monitoring module (2), an optical cable and sheath (3), a power supply unit (4), a demodulation and analysis system (5), a monitoring and early warning platform (6), a local early warning device (7), and an automatic centralized control execution terminal (8) for the pipeline system; the point monitoring (1) and the line monitoring (2) can be connected together to the demodulation and analysis system (5) through the optical cable and sheath (3), the demodulation and analysis system (5) is electrically connected to the monitoring and early warning platform (6) and the local early warning device (7), the monitoring and early warning platform (6) is also electrically connected to the local early warning device (7) and the automatic centralized control execution terminal (8) for the pipeline system, and the power supply unit (4) is electrically connected to the demodulation and analysis system (5);

[0009] Among them, the point monitoring (1) includes a cavity ring fixture (1-01) and a temperature sensor (1-02), an inclination sensor (1-03), a soil pressure sensor (1-04), a strain sensor (1-05), and a vibration sensor (1-06) installed in the cavity ring fixture (1-01), the cavity ring fixture (1-01) being fixed to the outer wall of the pipe; the line monitoring (2) includes an intelligent non-metallic composite pipe (2-01) and a welded protective sleeve (2-02) installed on the intelligent non-metallic composite pipe (2-01); for newly built main and branch pipelines, line monitoring is carried out based on an embedded intelligent non-metallic pressure pipe, the intelligent non-metallic pressure pipe ( In the pipeline production process, long and short period overlapping grating optical fibers (2-0102) are spirally embedded between the inner wall (2-0101) and the outer layer (2-0103) of the intelligent non-metallic pressure pipe, forming a tightly integrated whole with the intelligent non-metallic pressure pipe (2-01). A portion of the long and short period overlapping grating optical fibers (2-0102) is reserved at both ends of the intelligent non-metallic pressure pipe (2-01). A fusion splice protection sleeve (2-02) is set at the splice joint where a portion of the long and short period overlapping grating optical fibers (2-0102) is cut open at the end and spliced, which facilitates fusion splicing while protecting the optical fiber splice point and the electrofusion sleeve (2-02-01).

[0010] In an optional embodiment of the present invention, the cavity ring belt tooling (1-01) includes a flexible mounting plate (1-01-01), multiple left side brackets (1-01-02), multiple right side brackets (1-01-03), and multiple mounting guard plates (1-01-04);

[0011] The flexible mounting plate (1-01-01) is made of medium-hard polyurethane or polytetrafluoroethylene. Multiple left-side brackets (1-01-02) and multiple right-side brackets (1-01-03) are uniformly and symmetrically mounted on the long side of the flexible mounting plate (1-01-01). The left-side brackets (1-01-02) and the right-side brackets (1-01-03) are the same size and have a mirror-symmetrical structure.

[0012] The left support (1-01-02) includes a first base plate (1-01-0201), and the right support (1-01-03) includes a second base plate (1-01-0301). Both the first base plate (1-01-0201) and the second base plate (1-01-0301) are arc-shaped plates, unfolding into rectangles. A first sector plate (1-01-0202) and a second sector plate (1-01-0302) are respectively arranged perpendicular to their long sides on the first base plate (1-01-0201) and the second base plate (1-01-0301). The first sector plate (1-01-0202) and the second sector plate (1-01-0302) are respectively connected to the first top plate (1- The first top plate (1-01-0203) and the second top plate (1-01-0303) are both arc plates, which are rectangular when unfolded; the first top plate (1-01-0203) and the second top plate (1-01-0303) are respectively embedded with the first connecting plate (1-01-0204) and the second connecting plate (1-01-0304); the first top plate (1-01-0203) and the second top plate (1-01-0303) are provided with mounting guard plates (1-01-04); the mounting guard plates (1-01-04) are provided with multiple arc plate-shaped pressure plates (1-01-0402) arranged along their outer diameter.

[0013] In an optional embodiment of the present invention, the cavity-type ring belt tooling (1-01) includes multiple sensor mounting seats (1-01-05) and multiple tensioning and fixing plates (1-01-06); the multiple sensor mounting seats (1-01-05) are used for temperature sensors (1-02), tilt sensors (1-03), soil pressure sensors (1-04), strain sensors (1-05), and vibration sensors (1-06); the top shape of the multiple sensor mounting seats (1-01-05) is consistent with the bottom shape of the corresponding sensor, and the bottom shape is consistent with the arc of the flexible mounting plate (1-01-01);

[0014] The flexible mounting plate (1-01-01) has a first square hole (1-01-0101) at a preset position to attach and fix the strain sensor (1-05) to the outer wall of the pipe. The mounting guard plate (1-01-04) has a first through hole (1-04-0403) at the installation position of the soil pressure sensor (1-04). The pressure detection surface of the soil pressure sensor (1-04) is higher than the mounting guard plate (1-01-04). The tensioning and fixing plate (1-01-06) is a right-angled strip of angle iron and is used to tighten and fix the flexible mounting plate (1-01-01).

[0015] In an optional embodiment of the present invention, the first base plate (1-01-0201) and the second base plate (1-01-0301) have the same shape, the first sector plate (1-01-0202) and the second sector plate (1-01-0302) have the same shape, and the first top plate (1-01-0203) and the second top plate (1-01-0303) have the same shape.

[0016] In an optional embodiment of the present invention, the welding protective sleeve (2-02) includes an electrofusion sleeve (2-02-01), an inner thread protective sleeve (2-02-02), and an outer thread protective sleeve (2-02-03); the electrofusion sleeve (2-02-01) is fitted into the connector of the intelligent non-metallic pressure tube (2-01) for welding;

[0017] The spliced ​​long and short period overlapping grating optical fiber (2-01-02) is fixed outside the electrofusion sleeve (2-01). The outer wire protective sleeve (2-02-02) and the inner wire protective sleeve (2-02-03) are both concentric cylindrical variable diameter structures. The inner diameter of the first outer cylinder (2-02-0201) of the outer wire protective sleeve (2-02-02) and the second outer cylinder (2-02-0301) of the inner wire protective sleeve (2-02-03) is larger than the outer diameter of the intelligent non-metallic pressure tube (2-01).

[0018] In an optional embodiment of the present invention, the outer diameters of the first outer cylinder (2-02-0201) and the second outer cylinder (2-02-0301) are respectively provided with a plurality of first platforms (2-02-0204) and second platforms (2-02-0304); the first outer cylinder (2-02-0201) and the second outer cylinder (2-02-0301) are respectively connected to the first inner cylinder (2-02-0203) and the second inner cylinder (2-02-0303) through a first hollow frustum diameter reducer (2-02-0202) and a second hollow frustum diameter reducer (2-02-0302);

[0019] The first inner cylinder (2-02-0203) has a first internal thread (2-02-0205) on its inner diameter, and the second inner cylinder (2-02-0303) has a first frustum (2-02-0305) on its outer diameter. The first frustum (2-02-0305) has a first external thread (2-02-0306) on its lower side. The first internal thread (2-02-0205) and the first external thread (2-02-0306) are tightly engaged. The inner diameter of the second inner cylinder (2-02-0303) is larger than the outer diameter of the electrofusion sleeve (2-02-01). The fiber outlet can be sealed and connected to the optical cable and the sleeve (3) after the holes are opened in the first hollow frustum diameter reducer (2-02-0202) and the second hollow frustum diameter reducer (2-02-0302).

[0020] In an optional embodiment of the present invention, the linear monitoring (2) includes an outer thread protective sleeve (2-03), which is fixed to the intelligent non-metallic pressure tube (2-01).

[0021] This invention provides a method for monitoring and early warning of non-metallic pressure tubes using a point-line combined fiber optic grating, implemented through a monitoring and early warning system for non-metallic pressure tubes as described in the above embodiment. The method comprises the following steps:

[0022] Step 1, the point monitoring module (1) is implemented as follows: the temperature sensor (1-02), tilt sensor (1-03), soil pressure sensor (1-04), vibration sensor (1-06), sensor mounting base (1-01-05), and tension fixing plate (1-01-06) in the cavity ring fixture (1-01) are fixed to the flexible mounting plate (1-01-01) by standard screws and bolts; all sensor connection points and wires are connected in series and placed in the cavity ring fixture (1-01);

[0023] The flexible mounting plate (1-01-01) is wrapped around the outer wall of the pipeline to be monitored; multiple left-side brackets (1-01-02), multiple right-side brackets (1-01-03), and multiple mounting guards (1-01-04) are locked and fixed from the internal space of the cavity ring tool (1-01) by bolts. Three mounting guards (1-01-04) are reserved at the opening of the flexible mounting plate (1-01-01) and the first square hole (1-01-0101). After installing the strain sensor (1-05) and tightening the fixing plate (1-01-06) with bolts, the three mounting guards (1-01-04) are fixed. The fiber outlet position can be sealed and connected to the optical cable and the sleeve (3) after opening holes at the preset positions of the left-side bracket (1-01-02), the right-side bracket (1-01-03), and the mounting guard (1-01-04).

[0024] Step 2: In the production process of the intelligent non-metallic composite pipe (2-01), the inner wall of the intelligent non-metallic pressure pipe (1-0101) is first processed, then the pipe is reinforced, and the winding tension is precisely controlled to embed the long and short period overlapping grating optical fiber (2-0102) to ensure the survival rate of the fiber grating laying. Finally, the outer protective layer is wrapped.

[0025] Step 3, the implementation steps of the linear monitoring module (2) are as follows: Pass the inner wire protective sleeve (2-02-02), electrofusion sleeve (2-02-01), and outer wire protective sleeve (2-02-03) through the intelligent non-metallic composite tube (2-02) in sequence. Cut open the intelligent non-metallic composite tube (2-02) from the end and remove a portion of the long and short period overlapping grating fiber (2-0102). Align the connectors of the intelligent non-metallic composite tube (2-02) and electrofusion-connect the intelligent non-metallic composite tube (2-02) using the electrofusion sleeve (2-02-01). Heat-fuse the long and short period overlapping grating fiber (2-0102). The connector is fixed to the outer surface of the electrofusion sleeve (2-02-01). The inner thread protective sleeve (2-02-02) is fixed to the intelligent non-metallic composite tube (2-02) by adhesive bonding, hot melting or electrofusion at the selected preset position. The first internal thread (2-02-0205) of the inner thread protective sleeve (2-02-02) is engaged with the first external thread (2-02-0306) of the outer thread protective sleeve (2-02-03). The fiber outlet can be sealed and connected to the optical cable and the sleeve (3) after opening the first hollow frustum diameter reducer (2-02-0202) and the second hollow frustum diameter reducer (2-02-0302).

[0026] Step 4, the point monitoring module (1) and the line monitoring module (2) lead the optical cable together to the ground demodulation and analysis system (4) through the optical cable and the sleeve (3); use municipal energy AC220V or solar power DC12 / 24V as the power supply unit (4), the point monitoring module (1) and the line monitoring module (2) are combined to monitor the strain, temperature and vibration of the pipeline in service and newly built in real time, and on this basis, simulate various events such as excavation, leakage and bending, build a signal sample library, and deploy the signal sample library and intelligent recognition algorithm at the edge to directly feed back to the local early warning device (7) to realize local early warning, or wirelessly transmit the monitoring data or event information to the monitoring and early warning platform (6). The monitoring and early warning platform (5) can be combined with local video monitoring and personnel inspection to realize comprehensive judgment, and can automatically send the disposal results to the automatic centralized control execution terminal (8) of the pipeline system for early intervention, or control the local early warning device (7) for local early warning.

[0027] Compared with the prior art, the embodiments of the present invention provide a point-line combined fiber optic grating monitoring and early warning system and method for non-metallic pressure tubes, which has the following beneficial effects:

[0028] (1) For in-service pipelines, cavity-type ring-belt fixtures are installed in key areas or around the pipeline. These fixtures incorporate various new fiber optic grating sensors, enabling efficient and convenient installation. Installation is not constrained by pipeline tolerances, ensuring a tight fit and efficient and accurate transmission of parameters while effectively protecting the sensors from damage. The sensors are modularly installed, making installation convenient and efficient. Maintenance and replacement are convenient. The fixtures are reusable, and the ample internal space of the cavity-type ring-belt fixture allows for a scientifically sound fiber optic layout, effectively reducing losses.

[0029] (2) Ultra-long lifespan, corrosion resistance, and adaptability to pre-buried underground environments. Overlapping fiber optic long and short period grating arrays, core-cladding optical path transmission mode coupling and short period fiber optic grating forward-reverse optical path transmission mode coupling. Improved monitoring sensitivity of overlapping fiber optic gratings and signal-to-noise ratio, enabling the sensing of multiple parameters such as pipe vibration, temperature, deformation, and strain, while avoiding cross-sensitivity.

[0030] (3) Chinese Patent CN112230327A discloses "An all-glass encapsulation device and encapsulation method for fiber optic gratings". Based on this patented technology, this invention innovatively develops a new type of fiber optic grating sensor substrate. While possessing the characteristics of strong anti-interference capability, immunity to electromagnetic interference, high measurement accuracy, easy distributed networking, and good environmental adaptability of fiber optic grating sensors, this invention solves the problems of poor durability and stability of current sensors. Based on the new fiber optic grating sensor substrate, various novel fiber optic grating sensors have been developed, utilizing the fiber optic grating sensing principle to achieve high-precision measurement of parameters such as tilt, temperature, strain, vibration, and pressure.

[0031] (4) The point-type monitoring module and the line-type monitoring module can be connected together via optical fiber and conduit to the ground demodulation and analysis system, sharing one demodulation system. The demodulation and analysis system is a low-power product that can use municipal AC220V or solar power DC12 / 24V as its power supply unit, eliminating the need for separate wiring and meeting the requirements of on-site engineering construction. Furthermore, the demodulation and analysis system is equipped with multiple channels, which can be connected to surrounding pipelines for divergent monitoring, further reducing the space, cost, and energy consumption.

[0032] (5) The combination of point monitoring modules and line monitoring modules can realize real-time monitoring of multiple parameters such as pipeline strain, temperature, and vibration. Based on this, various events such as excavation, leakage, and bending can be simulated to build a signal sample library. The signal sample library and intelligent recognition algorithm can be deployed at the edge and directly fed back to the local early warning device to realize local early warning. Alternatively, the monitoring data or event information can be wirelessly transmitted to the monitoring and early warning platform. The monitoring and early warning platform can be combined with local video surveillance and personnel inspection to realize comprehensive judgment. The handling results can be automatically sent to the automatic centralized control execution terminal of the pipeline system for early intervention or to control the local early warning device for local early warning. The monitoring and early warning platform realizes centralized management and analysis of data, reducing the complexity and error of manual operation. Using optical monitoring, the energy consumption is low. Compared with traditional measurement methods, the system structure of this invention is simple, the cost is low, the response mode is fully adapted to China's national conditions, and it has strong operability, meets the diverse needs of users, and has practical application value.

[0033] (6) The point-type monitoring module and the line-type monitoring module can comprehensively cover the real-time online full-domain monitoring needs of in-service and newly built pipelines. Moreover, the cavity-type ring-belt tooling of the "point" type monitoring can be further modified to replace the welding protective sleeve of the "line" type monitoring to realize the integration of "point" and "line" monitoring of newly built pipelines, further improving the comprehensiveness of monitoring. The monitoring system of the present invention is simple and efficient to deploy and is not affected by construction.

[0034] (7) The cavity ring belt tooling adopts a socket design. The mounting guard plate, the left support, and the right support form a cross-reinforcement structure, which ensures the structural strength of the cavity ring belt tooling while facilitating installation.

[0035] (8) This point-line combined fiber optic grating monitoring and early warning system is suitable for non-metallic pressure pipelines in complex urban spatial environments. It can achieve accurate safety monitoring and early warning for newly built and in-service main and branch pipelines. For in-service main and branch pipelines, point monitoring is carried out based on a combination of various new silicon fiber optic grating sensors. Various new silicon fiber optic grating sensors are fixed to the outer wall of the pipeline using a cavity-type ring fixture, which protects the sensors while facilitating intelligent sensor perception. All serial connection points and wiring are placed inside the cavity-type ring fixture. For newly built main and branch pipelines, line monitoring is carried out based on embedded intelligent non-metallic pressure tubes. The intelligent non-metallic pressure tubes use long and short period overlapping grating optical fibers embedded inside the pipe body during the pipeline production process to form a tightly integrated whole with the pipeline. Fiber optic connectors are reserved at both ends, and fusion splice protection sleeves are set at the connectors to facilitate fusion splicing while protecting the fiber optic splice points.

[0036] Therefore, this invention proposes a point-line combined fiber optic grating monitoring and early warning system and method for non-metallic pressure tubes. This system addresses the problems of traditional fixed-point monitoring, which suffers from isolated points and independent parameters, making it unsuitable for complex and harsh environments, and leading to high false alarm rates in complex urban underground environments with frequent human activity. It also solves the problems of multi-parameter cross-sensitivity and long-distance loss inherent in PE-based composite tubes with fiber backscattering. Ultimately, it achieves real-time, online, efficient, and high-precision monitoring across the entire area. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a point-line combination fiber optic grating monitoring and early warning system for a non-metallic pressure tube, provided in an embodiment of this application.

[0039] Figure 2 This is a three-dimensional schematic diagram of a non-metallic pressure tube point-line combined fiber optic grating monitoring and early warning system provided in an embodiment of this application.

[0040] Figure 3 This is a schematic diagram of the point monitoring section of a point-line combined fiber optic grating monitoring and early warning system for a non-metallic pressure tube, provided as an embodiment of this application.

[0041] Figure 4 This is a schematic diagram of another part of the point monitoring structure of a point-line combined fiber optic grating monitoring and early warning system for a non-metallic pressure tube, provided in an embodiment of this application.

[0042] Figure 5 This is a schematic diagram of a linear monitoring structure for a point-line combined fiber optic grating monitoring and early warning system for a non-metallic pressure tube, provided as an embodiment of this application.

[0043] Figure 6 This is a schematic diagram of the left support of a non-metallic pressure tube point-line combined fiber optic grating monitoring and early warning system provided in an embodiment of this application.

[0044] Figure 7 This is a schematic diagram of the right support structure of a non-metallic pressure tube point-line combined fiber optic grating monitoring and early warning system provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The terms "upper," "lower," "front," "rear," "left," and "right," etc., used when describing the installation position or direction of the structure or components in this embodiment are based on the orientation shown in the accompanying drawings. They are merely for convenience of description, used to distinguish the relative positions of various components or directions, and do not represent the orientation of the system or functional components in this embodiment during use.

[0046] like Figures 1-7 As shown, this embodiment of the invention provides a point-to-line combined fiber optic grating monitoring and early warning system for non-metallic pressure pipes, including a point monitoring module 1, a line monitoring module 2, an optical cable and sheath 3, a power supply unit 4, a demodulation and analysis system 5, a monitoring and early warning platform 6, a local early warning device 7, and an automatic centralized control execution terminal 8 for the pipeline system; the point monitoring module 1 and the line monitoring module 2 can lead the optical cable together to the demodulation and analysis system 5 through the optical cable and sheath 3. The demodulation and analysis system 5 is electrically connected to the monitoring and early warning platform 6 and the local early warning device 7. The monitoring and early warning platform 6 is also electrically connected to the local early warning device 7 and the automatic centralized control execution terminal 8 for the pipeline system. The power supply unit 4 is electrically connected to the demodulation and analysis system 5.

[0047] Point monitoring module 1 and line monitoring module 02 can be connected together via optical fiber and conduit 03 to the ground demodulation and analysis system 5. The demodulation and analysis system is a low-power product and can use municipal AC220V or solar-powered DC12 / 24V as the power supply unit 4. The combination of point monitoring module 1 and line monitoring module 2 can realize real-time monitoring of multiple parameters such as pipeline strain, temperature, and vibration. Based on this, it can simulate various events such as excavation, leakage, and bending to build a signal sample library. The signal sample library and intelligent recognition algorithm can be deployed at the edge and directly fed back to the local early warning device 7 to realize local early warning. Alternatively, the monitoring data or event information can be wirelessly transmitted to the monitoring and early warning platform 6. The monitoring and early warning platform 5 can be combined with local video surveillance and personnel inspection to realize comprehensive judgment. It can also automatically send the handling results to the automatic centralized control execution terminal 8 of the pipeline system for early intervention or control the local early warning device 7 for local early warning.

[0048] Specifically, such as Figure 1 and Figure 2As shown, the point monitoring 1 includes a cavity ring fixture 1-01 and a temperature sensor 1-02, an inclination sensor 1-03, an earth pressure sensor 1-04, a strain sensor 1-05, and a vibration sensor 1-06 installed inside the cavity ring fixture 1-01. The cavity ring fixture 1-01 is used to protect the sensors. The cavity ring fixture 1-01 is fixed to the outer wall of the pipe, and all sensor connection points and wiring are placed inside the cavity ring fixture 1-01.

[0049] like Figure 2 and Figure 5 As shown, the linear monitoring system 2 includes an intelligent non-metallic composite pipe 2-01 and a fusion splice protection sleeve 2-02 installed on the intelligent non-metallic composite pipe 2-01. For newly constructed main and branch pipelines, linear monitoring is conducted based on an embedded intelligent non-metallic pressure pipe. Long-short period overlapping grating optical fibers 2-0102 are spirally embedded between the inner wall 2-0101 and the outer layer 2-0103 of the intelligent non-metallic pressure pipe during pipeline production, forming a tightly integrated whole with the intelligent non-metallic pressure pipe 2-01. A portion of the long-short period overlapping grating optical fiber 2-0102 is reserved at both ends of the intelligent non-metallic pressure pipe 2-01. A fusion splice protection sleeve 2-02 is installed at the joint where a portion of the long-short period overlapping grating optical fiber 2-0102 is cut open at the end for fusion splicing, facilitating fusion while protecting the fiber optic splice point and the electrofusion sleeve 2-02-01.

[0050] like Figure 2 , Figure 3 and Figure 4 As shown, the cavity-type ring belt fixture 1-01 includes a flexible mounting plate 1-01-01, multiple left-side supports 1-01-02, multiple right-side supports 1-01-03, and multiple mounting guard plates 1-01-04. The flexible mounting plate 1-01-01 is made of medium-hard polyurethane or polytetrafluoroethylene sheet, requiring certain strength, elasticity, corrosion resistance, and aging resistance. When unfolded, it is rectangular; when bent, it forms a single-layer open roll, with an inner diameter approximately the same as the pipe diameter. Multiple left-side supports 1-01-02 and multiple right-side supports 1-01-03 are evenly and symmetrically mounted on the long side of the flexible mounting plate 1-01-01. The left-side supports 1-01-02 and right-side supports 1-01-03 are identical in size and have a mirror-symmetrical structure.

[0051] like Figure 6 and Figure 7As shown, the left support 1-01-02 includes a first base plate 1-01-0201, and the right support 1-01-03 includes a second base plate 1-01-0301. Both the first base plate 1-01-0201 and the second base plate 1-01-0301 are arc-shaped plates, which unfold into rectangles. A first sector plate 1-01-0202 and a second sector plate 1-01-0302 are respectively arranged perpendicular to the long sides of the first base plate 1-01-0201 and the second base plate 1-01-0301. The first sector plate 1-01-0202 and the second sector plate 1-01-0302 are respectively connected to the first top plate 1-01-0203 and the second top plate 1-01. -0303, the first top plate 1-01-0203 and the second top plate 1-01-0303 are both arc plates, which are rectangular when unfolded; the first top plate 1-01-0203 and the second top plate 1-01-0303 are respectively embedded with the first connecting plate 1-01-0204 and the second connecting plate 1-01-0304; the first top plate 1-01-0203 and the second top plate 1-01-0303 are both provided with mounting guard plates 1-01-04; multiple arc plate-shaped pressure plates 1-01-0402 are arranged along the outer diameter of the mounting guard plates 1-01-04, and the multiple mounting guard plates 1-01-04 are fitted together front and back.

[0052] like Figure 2 , Figure 3 and Figure 4 As shown, the cavity-type ring belt fixture 1-01 includes multiple sensor mounting seats 1-01-05 and multiple tensioning and fixing plates 1-01-06; the multiple sensor mounting seats 1-01-05 are used for temperature sensor 1-02, tilt sensor 1-03, soil pressure sensor 1-04, strain sensor 1-05, and vibration sensor 1-06; the top shape of the multiple sensor mounting seats 1-01-05 is consistent with the bottom shape of the corresponding sensor, and the bottom shape is consistent with the arc of the flexible mounting plate 1-01-01.

[0053] The flexible mounting plate 1-01-01 has a first square hole 1-01-0101 at a preset position to attach and fix the strain sensor 1-05 to the outer wall of the tube. The mounting guard plate 1-01-04 has a first through hole 1-04-0403 at the installation position of the soil pressure sensor 1-04, and the pressure detection surface of the soil pressure sensor 1-04 is higher than the mounting guard plate 1-01-04. The tension fixing plate 1-01-06 is a right-angled strip of angle iron, used to tighten and fix the flexible mounting plate 1-01-01. All the above-mentioned sensor components and sensor mounting bases are connected by standard screws and bolts.

[0054] Preferably, the first base plate 1-01-0201 and the second base plate 1-01-0301 have the same shape, the first sector plate 1-01-0202 and the second sector plate 1-01-0302 have the same shape, and the first top plate 1-01-0203 and the second top plate 1-01-0303 have the same shape.

[0055] like Figure 2 and Figure 5 As shown, the welding protection sleeve 2-02 includes an electrofusion sleeve 2-02-01, an inner thread protection sleeve 2-02-02, and an outer thread protection sleeve 2-02-03; the electrofusion sleeve 2-02-01 is fitted into the connector of the intelligent non-metallic pressure tube 2-01 for welding.

[0056] After fusion splicing, the long and short period overlapping grating optical fiber 2-01-02 is fixed outside the electrofusion sleeve 2-01. The outer wire protective sleeve 2-02-02 and the inner wire protective sleeve 2-02-03 are both concentric cylindrical variable diameter structures. The inner diameter of the first outer cylinder 2-02-0201 of the outer wire protective sleeve 2-02-02 and the second outer cylinder 2-02-0301 of the inner wire protective sleeve 2-02-03 is larger than the outer diameter of the intelligent non-metallic pressure tube 2-01.

[0057] Multiple first platforms 2-02-0204 and second platforms 2-02-0304 are respectively opened on the outer diameter of the first outer cylinder 2-02-0201 and the second outer cylinder 2-02-0301; the first outer cylinder 2-02-0201 and the second outer cylinder 2-02-0301 are respectively connected to the first inner cylinder 2-02-0203 and the second inner cylinder 2-02-0303 through the first hollow frustum diameter changer 2-02-0202 and the second hollow frustum diameter changer 2-02-0302.

[0058] The inner diameter of the first inner cylinder 2-02-0203 of the external thread protective sleeve 2-02-02 has a first internal thread 2-02-0205, and the outer diameter of the second inner cylinder 2-02-0303 of the internal thread protective sleeve 2-02-03 has a first frustum 2-02-0305, and the first external thread 2-02-0306 is opened under the first frustum 2-02-0305; the first internal thread 2-02-0205 and the first external thread 2-02-0306 are tightly engaged; the inner diameter of the second inner cylinder 2-02-0303 is larger than the outer diameter of the electrofusion sleeve 2-02-01; the fiber outlet can be sealed and connected to the optical cable and the sleeve 3 after the holes are opened in the first hollow frustum diameter reducer 2-02-0202 and the second hollow frustum diameter reducer 2-02-0302. The linear monitoring system 2 includes an external thread protective sleeve 2-03, which is fixed to the intelligent non-metallic pressure tube 2-01.

[0059] This invention also provides a method for monitoring and early warning of a non-metallic pressure tube using a point-line combined fiber optic grating, implemented through a monitoring and early warning system for a non-metallic pressure tube as described in the above embodiments. The monitoring and early warning method includes the following steps:

[0060] Step 1, the implementation steps of point monitoring module 1 are as follows: The temperature sensor 1-02, tilt sensor 1-03, soil pressure sensor 1-04, vibration sensor 1-06, sensor mounting base 1-01-05, and tension fixing plate 1-01-06 in the cavity ring belt fixture 1-01 are fixed to the flexible mounting plate 1-01-01 by standard parts screws and bolts; after all sensor serial connection points and wiring are connected in series, they are placed in the cavity ring belt fixture 1-01.

[0061] The flexible mounting plate 1-01-01 is wrapped around the outer wall of the pipeline to be monitored. Multiple left-side brackets 1-01-02, multiple right-side brackets 1-01-03, and multiple mounting guards 1-01-04 are fixed by bolts through the internal space of the cavity-type ring tool 1-01. Three mounting guards 1-01-04 are reserved at the opening of the flexible mounting plate 1-01-01 and the first square hole 1-01-0101. After installing the strain sensor 1-05, the fixing plate 1-01-06 is tightened by bolts, and then the three mounting guards 1-01-04 are fixed. The fiber outlet can be connected to the optical cable and the sleeve 3 by making holes at the preset positions of the left-side bracket 1-01-02, the right-side bracket 1-01-03, and the mounting guard 1-01-04.

[0062] Step 2: In the production process of intelligent non-metallic composite pipe 2-01, the inner wall 1-0101 of the intelligent non-metallic pressure pipe is first processed, then the pipe is reinforced, and the winding tension is precisely controlled to embed the long and short period overlapping grating optical fiber 2-0102 in a spiral to ensure the survival rate of the fiber grating laying. Finally, the outer protective layer is applied.

[0063] Step 3, the implementation steps of the linear monitoring module 2 are as follows: Pass the inner wire protective sleeve 2-02-02, electrofusion sleeve 2-02-01, and outer wire protective sleeve 2-02-03 through the intelligent non-metallic composite tube 2-02 in sequence. Cut open the intelligent non-metallic composite tube 2-02 near the end and remove a portion of the long and short period overlapping grating fiber 2-0102. Align the connectors of the intelligent non-metallic composite tube 2-02 and electrofusion-connect the intelligent non-metallic composite tube 2-02 using the electrofusion sleeve 2-02-01. Then, heat-fuse the long and short period overlapping grating fiber 2-0102. The connector is fixed to the outer surface of the electrofusion sleeve 2-02-01. The inner thread protective sleeve 2-02-02 is fixed to the intelligent non-metallic composite tube 2-02 by adhesive, hot melting or electrofusion at the selected preset position. The first internal thread 2-02-0205 of the inner thread protective sleeve 2-02-02 is engaged with the first external thread 2-02-0306 of the outer thread protective sleeve 2-02-03. The fiber outlet can be sealed and connected to the optical cable and the sleeve 3 after the holes are opened in the first hollow frustum diameter reducer 2-02-0202 and the second hollow frustum diameter reducer 2-02-0302.

[0064] Step 4: Point monitoring module 1 and line monitoring module 2 are connected together via optical fiber and conduit 3 to the ground demodulation and analysis system 4. The power supply unit 4 is powered by municipal energy AC220V or solar power DC12 / 24V. The point monitoring module 1 and line monitoring module 2 are combined to monitor multiple parameters such as strain, temperature and vibration of in-service and newly built pipelines in real time. Based on this, various events such as excavation, leakage and bending are simulated to build a signal sample library. The signal sample library and intelligent recognition algorithm are deployed at the edge and can be directly fed back to the local early warning device 7 to realize local early warning. Alternatively, the monitoring data or event information can be wirelessly transmitted to the monitoring and early warning platform 6. The monitoring and early warning platform 5 can be combined with local video surveillance and personnel inspection to realize comprehensive judgment. The handling results can be automatically sent to the automatic centralized control execution terminal 8 of the pipeline system for early intervention or to control the local early warning device 7 for local early warning.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A point-line combined fiber optic grating monitoring and early warning system for a non-metallic pressure tube, characterized in that, The system includes a point monitoring module (1), a line monitoring module (2), an optical cable and sheath (3), a power supply unit (4), a demodulation analysis system (5), a monitoring and early warning platform (6), a local early warning device (7), and an automatic centralized control execution terminal (8) for the pipeline system. The point monitoring module (1) and the line monitoring module (2) can lead the optical cable to the demodulation analysis system (5) through the optical cable and sheath (3). The demodulation analysis system (5) is electrically connected to the monitoring and early warning platform (6) and the local early warning device (7). The monitoring and early warning platform (6) is also electrically connected to the local early warning device (7) and the automatic centralized control execution terminal (8) for the pipeline system. The power supply unit (4) is electrically connected to the demodulation analysis system (5). The point monitoring module (1) includes a cavity-type ring fixture (1-01) and a temperature sensor (1-02), an inclination sensor (1-03), an earth pressure sensor (1-04), a strain sensor (1-05), and a vibration sensor (1-06) installed inside the cavity-type ring fixture (1-01). The cavity-type ring fixture (1-01) is fixed to the outer wall of the pipeline. The line monitoring module (2) includes an intelligent non-metallic composite pipe (2-01) and a welded protective sleeve (2-02) installed on the intelligent non-metallic composite pipe (2-01). Linear monitoring is carried out on newly built main and branch pipelines based on embedded intelligent non-metallic pressure pipes. Inside the tube (2-01), long and short period overlapping grating optical fibers (2-0102) are spirally embedded between the inner wall (2-0101) and the outer layer (2-0103) of the intelligent non-metallic pressure tube during the tube production process, forming a tightly integrated whole with the intelligent non-metallic pressure tube (2-01). A portion of the long and short period overlapping grating optical fibers (2-0102) is reserved at both ends of the intelligent non-metallic pressure tube (2-01). A fusion splice protection sleeve (2-02) is set at the joint where the long and short period overlapping grating optical fibers (2-0102) are cut open at the end and fused, which facilitates fusion splicing while protecting the optical fiber fusion splice point and the electrofusion sleeve (2-02-01). The cavity ring belt tooling (1-01) includes a flexible mounting plate (1-01-01), multiple left side brackets (1-01-02), multiple right side brackets (1-01-03), and multiple mounting guard plates (1-01-04). The flexible mounting plate (1-01-01) is made of medium-hard polyurethane or polytetrafluoroethylene. Multiple left-side brackets (1-01-02) and multiple right-side brackets (1-01-03) are uniformly and symmetrically installed on the long side of the flexible mounting plate (1-01-01). The left-side brackets (1-01-02) and the right-side brackets (1-01-03) are the same size and have a mirror-symmetrical structure. The left support (1-01-02) includes a first base plate (1-01-0201), and the right support (1-01-03) includes a second base plate (1-01-0301). Both the first base plate (1-01-0201) and the second base plate (1-01-0301) are arc-shaped plates that unfold into rectangles. A first sector plate (1-01-0202) and a second sector plate (1-01-0302) are respectively arranged perpendicular to their long sides on the first base plate (1-01-0201) and the second base plate (1-01-0301). The first sector plate (1-01-0202) and the second sector plate (1-01-0302) are respectively connected to the first top plate (1... -01-0203) and the second top plate (1-01-0303), the first top plate (1-01-0203) and the second top plate (1-01-0303) are both arc plates, which are rectangular when unfolded; the first top plate (1-01-0203) and the second top plate (1-01-0303) are respectively embedded with the first connecting plate (1-01-0204) and the second connecting plate (1-01-0304); the first top plate (1-01-0203) and the second top plate (1-01-0303) are provided with mounting guard plates (1-01-04); the mounting guard plates (1-01-04) are provided with multiple arc plate-shaped pressure plates (1-01-0402) arranged along their outer diameter.

2. The point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes according to claim 1, characterized in that, The cavity-type ring-shaped tooling (1-01) includes multiple sensor mounting seats (1-01-05) and multiple tensioning and fixing plates (1-01-06); the multiple sensor mounting seats (1-01-05) are used for temperature sensors (1-02), tilt sensors (1-03), soil pressure sensors (1-04), strain sensors (1-05), and vibration sensors (1-06); the top shape of the multiple sensor mounting seats (1-01-05) is consistent with the bottom shape of the corresponding sensor, and the bottom shape is consistent with the arc shape of the flexible mounting plate (1-01-01); The flexible mounting plate (1-01-01) has a first square hole (1-01-0101) at a preset position to attach and fix the strain sensor (1-05) to the outer wall of the pipe. The mounting guard plate (1-01-04) has a first through hole (1-04-0403) at the installation position of the soil pressure sensor (1-04). The pressure detection surface of the soil pressure sensor (1-04) is higher than the mounting guard plate (1-01-04). The tensioning and fixing plate (1-01-06) is a right-angled strip of angle iron and is used to tighten and fix the flexible mounting plate (1-01-01).

3. The point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes according to claim 1, characterized in that, The first base plate (1-01-0201) and the second base plate (1-01-0301) have the same shape, the first sector plate (1-01-0202) and the second sector plate (1-01-0302) have the same shape, and the first top plate (1-01-0203) and the second top plate (1-01-0303) have the same shape.

4. The point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes according to claim 2, characterized in that, The welding protection sleeve (2-02) includes an electrofusion sleeve (2-02-01), an inner thread protective sleeve (2-02-02), and an outer thread protective sleeve (2-02-03); the electrofusion sleeve (2-02-01) is fitted into the connector of the intelligent non-metallic pressure tube (2-01) for welding; The spliced ​​long and short period overlapping grating optical fiber (2-01-02) is fixed outside the electrofusion sleeve (2-02-01). The inner wire protective sleeve (2-02-02) and the outer wire protective sleeve (2-02-03) are both concentric cylindrical variable diameter structures. The inner diameter of the first outer cylinder (2-02-0201) of the inner wire protective sleeve (2-02-02) and the second outer cylinder (2-02-0301) of the outer wire protective sleeve (2-02-03) are larger than the outer diameter of the intelligent non-metallic pressure tube (2-01).

5. The point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes according to claim 4, characterized in that, The outer diameters of the first outer cylinder (2-02-0201) and the second outer cylinder (2-02-0301) are respectively provided with multiple first platforms (2-02-0204) and second platforms (2-02-0304); the first outer cylinder (2-02-0201) and the second outer cylinder (2-02-0301) are respectively connected to the first inner cylinder (2-02-0203) and the second inner cylinder (2-02-0303) through the first hollow frustum diameter reducer (2-02-0202) and the second hollow frustum diameter reducer (2-02-0302); The inner diameter of the first inner cylinder (2-02-0203) is provided with a first internal thread (2-02-0205), and the outer diameter of the second inner cylinder (2-02-0303) is provided with a first frustum (2-02-0305). The first frustum (2-02-0305) is provided with a first external thread (2-02-0306). The first internal thread (2-02-0205) and the first external thread (2-02-0306) are tightly engaged. The inner diameter of the second inner cylinder (2-02-0303) is larger than the outer diameter of the electrofusion sleeve (2-02-01). The fiber outlet can be sealed and connected to the optical cable and the sleeve (3) after the holes are opened in the first hollow frustum diameter reducer (2-02-0202) and the second hollow frustum diameter reducer (2-02-0302).

6. The point-line combined fiber optic grating monitoring and early warning system for non-metallic pressure tubes according to claim 5, characterized in that, The linear monitoring module (2) includes an outer wire protective sleeve (2-03), which is fixed to the intelligent non-metallic pressure tube (2-01).

7. A method for monitoring and early warning of a non-metallic pressure tube using a point-line combined fiber optic grating, implemented by a point-line combined fiber optic grating monitoring and early warning system for a non-metallic pressure tube as described in claim 6, characterized in that... The monitoring and early warning method includes the following steps: Step 1, the point monitoring module (1) is implemented as follows: the temperature sensor (1-02), tilt sensor (1-03), soil pressure sensor (1-04), vibration sensor (1-06), sensor mounting base (1-01-05), and tension fixing plate (1-01-06) in the cavity ring fixture (1-01) are connected and fixed to the flexible mounting plate (1-01-01) by standard screws and bolts; all sensor connection points and wires are connected in series and placed in the cavity ring fixture (1-01); The flexible mounting plate (1-01-01) is wrapped around the outer wall of the pipeline to be monitored; multiple left-side brackets (1-01-02), multiple right-side brackets (1-01-03), and multiple mounting guards (1-01-04) are locked and fixed from the internal space of the cavity ring tool (1-01) by bolts. Three of the mounting guards (1-01-04) are reserved at the opening of the flexible mounting plate (1-01-01) and the first square hole (1-01-0101). After installing the strain sensor (1-05) and tightening the fixing plate (1-01-06) with bolts, the three mounting guards (1-01-04) are fixed. The fiber outlet can be sealed and connected to the optical cable and the sheath (3) after opening holes at the preset positions of the left-side bracket (1-01-02), the right-side bracket (1-01-03), and the mounting guard (1-01-04). Step 2: In the production process of the intelligent non-metallic composite pipe (2-01), the inner wall of the intelligent non-metallic pressure pipe (1-0101) is first processed, then the pipe is reinforced, and the winding tension is precisely controlled to embed the long and short period overlapping grating optical fiber (2-0102) to ensure the survival rate of the fiber grating laying. Finally, the outer protective layer is applied. Step 3, the implementation steps of the linear monitoring module (2) are as follows: Pass the inner wire protective sleeve (2-02-02), electrofusion sleeve (2-02-01), and outer wire protective sleeve (2-02-03) through the intelligent non-metallic composite tube (2-01) in sequence. Cut open the intelligent non-metallic composite tube (2-01) from the end and remove a portion of the long and short period overlapping grating fiber (2-0102). Align the connectors of the intelligent non-metallic composite tube (2-01) and electrofusion-connect the intelligent non-metallic composite tube (2-02) using the electrofusion sleeve (2-02-01). Heat-fuse the long and short period overlapping grating fiber (2-0102). The connector is fixed to the outer surface of the electrofusion sleeve (2-02-01). The inner thread protective sleeve (2-02-02) is fixed to the intelligent non-metallic composite tube (2-01) by adhesive, hot melting or electrofusion at the selected preset position. The first internal thread (2-02-0205) of the inner thread protective sleeve (2-02-02) is engaged with the first external thread (2-02-0306) of the outer thread protective sleeve (2-02-03). The fiber outlet can be sealed and connected to the optical cable and the sleeve (3) after the holes are opened in the first hollow frustum diameter reducer (2-02-0202) and the second hollow frustum diameter reducer (2-02-0302). Step 4, the point monitoring module (1) and the line monitoring module (2) lead the optical cable together to the ground demodulation and analysis system (5) through the optical cable and the sleeve (3); use municipal energy AC220V or solar power DC12 / 24V as the power supply unit (4), the point monitoring module (1) and the line monitoring module (2) are combined to monitor the strain, temperature and vibration of the pipeline in service and newly built in real time, and on this basis, simulate various events such as excavation, leakage and bending, build a signal sample library, and deploy the signal sample library and intelligent recognition algorithm at the edge to directly feed back to the local early warning device (7) to realize local early warning, or wirelessly transmit the monitoring data or event information to the monitoring and early warning platform (6). The monitoring and early warning platform (6) can be combined with local video monitoring and personnel inspection to realize comprehensive judgment, and can automatically send the disposal results to the automatic centralized control execution terminal (8) of the pipeline system for early intervention, or control the local early warning device (7) for local early warning.

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