Method and apparatus for bend self-reinforcement treatment

Abstract

The application relates to the field of ultrahigh-pressure container manufacturing and testing, and relates to a bend self-reinforcing treatment method and device. The method comprises the following steps: connecting a first bend and a second bend in series in a butt joint mode, so that the inner cavities of the first bend and the second bend are in communication to form a closed pressurized loop; obtaining strain data of the first bend and the second bend; based on the strain data, injecting a test medium into the closed pressurized loop until the strain data reaches a preset plastic deformation threshold. According to the application, the first bend and the second bend are connected in a butt joint mode to form a closed pressurized loop in communication, which replaces the structure of a single bend matched with a blind flange for plugging, the axial stress condition of the whole system is improved, the residual compressive stress formed on the inner wall of the bend is more uniform, and the quality and effect of the self-reinforcing treatment are improved; and the method can complete the treatment of two bends at a time, and the operation efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of ultra-high pressure vessel manufacturing and testing, and to a method and apparatus for self-reinforcing bending pipes. Background Technology

[0002] In the field of ultra-high pressure tubular reactor manufacturing, elbows are key pressure-bearing components. To improve fatigue life and load-bearing capacity, a self-reinforcing treatment technology is usually adopted, which involves applying ultra-high pressure liquid exceeding the material's yield limit to the inside of the elbow, causing plastic deformation of the inner wall while the outer wall maintains elastic deformation. After depressurization, residual compressive stress is formed on the inner wall.

[0003] Existing technical solutions typically employ a single elbow with a blind flange sealing method. This involves installing an elbow on a pressure testing frame, connecting one end to a high-pressure pump, and installing a heavy blind flange or solid plug at the other end to seal the pipeline and establish high pressure. However, this approach suffers from technical problems such as potentially causing severe pressure fluctuations leading to uneven stress distribution, excessive axial load on the blind flange, and low efficiency in single-processing. In practical applications, this structure easily results in poor pressure control stability, requiring extremely large bolts and heavy clamps for restraint, leading to low clamping efficiency and safety hazards. Summary of the Invention

[0004] To solve, or at least partially solve, the above-mentioned technical problems, this application provides a method for self-reinforcing bending of pipes, comprising: Connect the first bend and the second bend end to end in series so that the inner cavities of the first bend and the second bend are interconnected to form a closed pressurized circuit. Obtain strain data for the first and second bends; Based on strain data, test medium is injected into a closed pressurized circuit until the strain data reaches a preset plastic deformation threshold derived from the yield strength of the bent pipe material.

[0005] The technical solution of this application replaces the previous structure of a single bend with a blind flange by connecting the first and second bends end-to-end to form an interconnected closed pressurization circuit. This series structure allows the hydraulic loads within the pressurization circuit to compensate for each other and automatically balance during the self-reinforcing treatment with the injection of test medium, thus improving the axial stress of the entire system. This directly and effectively avoids the risk of displacement or ejection of the blind flange due to the enormous unidirectional pressure in traditional solutions, eliminating this safety hazard. It also eliminates the need for large bolts and heavy clamps for forced restraint, simplifying the clamping operation. Simultaneously, by removing the bulky end-sealing components, factors that easily cause pressure fluctuations and elastic deformation areas in the system are reduced, resulting in more stable pressure control during pressurization. This helps to form a more uniform residual compressive stress on the inner wall of the bend, thereby improving the quality and effect of the self-reinforcing treatment. Furthermore, this solution can process two bends at once, significantly improving work efficiency compared to processing one bend at a time.

[0006] Optionally, the step of connecting the first bend and the second bend end-to-end in series includes: A connecting component is installed between the port of the first bend and the port of the second bend; A closed pressurized circuit is constructed by sealing the port of the first bend with the port of the second bend using a connecting assembly.

[0007] By adopting the above technical solution and utilizing the cooperation of the butt joint and the seal, a closed circuit is constructed, ensuring zero leakage of the pressurized medium.

[0008] Optionally, the step of sealing the port of the first bend and the port of the second bend together by means of a connecting assembly includes: A bidirectional sealing mandrel is provided, with seals at both ends and a connecting channel in the middle; The first end of the bidirectional sealing mandrel is inserted into the port of the first bend, and a seal is formed between the sealing element located at the first end and the inner wall of the first bend. The second end of the bidirectional sealing mandrel is inserted into the port of the second bend, and a seal is formed between the sealing element located at the second end and the inner wall of the second bend. The connecting channel connects the inner cavity of the first bend and the inner cavity of the second bend.

[0009] By adopting the above technical solution, self-tightening sealing is achieved by utilizing the pressure of the medium. The higher the pressure, the tighter the seal, thus overcoming the defect of easy leakage in traditional forced sealing.

[0010] Optionally, the steps for obtaining strain data of the first bend and the second bend include: Strain monitoring modules are installed at multiple locations on the surfaces of the first and second bends. These modules are configured to monitor the strain data of the first and second bends in real time.

[0011] By adopting the above technical solution, a comprehensive perception of the stress state of the bend was achieved, providing accurate data input for closed-loop control.

[0012] Optionally, the step of installing strain monitoring modules at multiple locations on the surfaces of the first and second bends includes: At least one first monitoring section is selected on the outer wall of the first bend, and at least one second monitoring section is selected on the outer wall of the second bend. Strain monitoring module measuring points are arranged on the first and second monitoring sections respectively to collect strain signals at each measuring point.

[0013] By adopting the above technical solution, the representativeness of the monitoring data is ensured, and the deformation of key parts of the bend is reflected.

[0014] Optionally, the step of arranging stress-strain detection device measuring points on the first monitoring section and the second monitoring section respectively includes: Strain acquisition points were set at 0°, 90°, 180° and 270° along the circumference of the first and second monitoring sections, respectively. The circumferential strain data and axial strain data of the first bend and the second bend were monitored through strain acquisition points.

[0015] By adopting the above technical solutions, it is possible to identify elliptic or bending deformations that may exist in the bend, thereby improving the comprehensiveness of monitoring.

[0016] Optionally, the process of acquiring strain data for the first bend and the second bend also includes: Real-time determination of whether the rate of change of strain data exceeds a preset rate of change threshold, or determination of whether the strain data deviation between the first bend and the second bend exceeds a preset deviation threshold; If the judgment result is yes, then the pressure reduction operation is performed on the closed pressurization circuit.

[0017] By adopting the above technical solution, an active safety protection mechanism is provided to prevent workpiece failure caused by local overload or assembly misalignment.

[0018] Optionally, based on strain data, the step of injecting the test medium into the closed pressurization circuit includes: Perform multi-stage pressurization operations to gradually increase the pressure in the closed pressurization circuit to the target pressure; After the pressure reaches the target pressure, a pressure holding operation is performed to maintain the pressure at a constant value for a preset time.

[0019] By adopting the above technical solution, the stability of the plastic deformation process is ensured, and material damage caused by pressure peaks is avoided.

[0020] Optionally, during the multi-stage boost operation, the following are also included: Before the pressure rises to the target pressure point corresponding to the plastic deformation threshold of the first bend and the second bend, an intermediate pressure holding step is performed; During the intermediate pressure holding step, the strain data of the first bend and the strain data of the second bend are compared. If the strain data of the two exceed the preset consistency tolerance, adjust the pressure boosting parameters or perform a pressure reduction operation on the closed pressurization circuit.

[0021] By adopting the above technical solution, the consistency of the double-bend pipe treatment effect is ensured, and the uneven enhancement effect caused by individual differences is avoided.

[0022] Optionally, after performing the pressure holding operation, the following steps are also included: Perform a staged depressurization operation to reduce the pressure in the closed pressurization circuit from the target pressure to atmospheric pressure.

[0023] By adopting the above technical solution, the deterioration of residual stress distribution or crack initiation caused by rapid pressure relief is avoided, thus ensuring the integrity of the workpiece.

[0024] Another aspect of this application provides a self-reinforcing device for bent pipes, comprising: A connecting assembly is used to connect the first bend and the second bend, so as to connect the first bend and the second bend end to end in series, so that the inner cavity of the first bend and the inner cavity of the second bend are interconnected to form a closed pressurized circuit. The strain monitoring module is used to connect the first bend and the second bend to obtain strain data of the first bend and the second bend. The pressurization assembly, connected to the connection assembly, is used to inject the test medium into the closed pressurization circuit; The control module is connected to both the strain monitoring module and the pressurization component, and is configured to control the pressurization component to perform injection operations based on strain data until the strain data reaches the preset plastic deformation threshold.

[0025] By adopting the above technical solution, a special device is provided that can achieve stable, efficient, and safe self-reinforcing treatment of double-bend pipes, and also possesses all the advantages mentioned in the above method.

[0026] Optionally, the connection component includes: The mating joint has a first connecting end and a second connecting end, the first connecting end being connected to the port of a first bend, and the second connecting end being connected to the port of a second bend. Sealing elements are respectively disposed at the first connecting end and the second connecting end, and are used to abut against the inner walls of the first bend and the second bend to seal the connection gap; A locking component connects the first bend, the second bend, and the mating joint, and is used to fix the mating joint between the first bend and the second bend.

[0027] By adopting the above technical solution, the basic composition of the device connection components was clarified, ensuring the reliability of the physical connection.

[0028] Optionally, the mating joint includes a bidirectional sealing mandrel; the bidirectional sealing mandrel has a flow channel inside, the flow channel connecting the first connecting end and the second connecting end, so that the inner cavity of the first bend and the inner cavity of the second bend are interconnected to form a closed pressurized circuit; the outer wall of the bidirectional sealing mandrel has a first sealing groove and a second sealing groove, the first sealing groove and the second sealing groove being located at the first connecting end and the second connecting end, respectively; The sealing element includes a first sealing ring and a second sealing ring; the first sealing ring is embedded in the first sealing groove and presses against the inner wall of the first bend under the pressure of the test medium to seal the gap between the first connecting end and the first bend; the second sealing ring is embedded in the second sealing groove and presses against the inner wall of the second bend under the pressure of the test medium to seal the gap between the second connecting end and the second bend.

[0029] By adopting the above technical solution, a specific self-tightening sealing implementation structure is provided on the device side, which utilizes the sealing ring to achieve a tighter seal as the pressure increases.

[0030] Optionally, the locking element includes a first flange and a second flange; The first flange is fixedly connected to the port of the first bend, and the second flange is fixedly connected to the port of the second bend. The first and second flanges are detachably connected by pre-tightened studs.

[0031] The flange connection improves the connection strength between the double bends, providing stable test conditions for pressure testing.

[0032] Optionally, the strain monitoring module includes multiple strain sensors; Strain sensors are attached to the outer surfaces of the first and second bends to collect strain data of the outer surfaces during the pressurization process.

[0033] By adopting the above technical solution, the physical installation method of the sensor was clarified, ensuring direct measurement of surface deformation.

[0034] Optionally, strain sensors are spaced apart along the circumferential direction of the outer surfaces of the first and second bends; The strain sensor can be placed at least at the 0°, 90°, 180° and 270° positions.

[0035] By adopting the above technical solution, it is ensured that the device can capture uniformity data in the circumferential direction.

[0036] Optionally, the strain sensor includes: a circumferential strain gauge and an axial strain gauge; Circumferential strain gauges are used to monitor the circumferential expansion and deformation of the first and second bends. Axial strain gauges are used to monitor the axial elongation deformation of the first and second bends.

[0037] By adopting the above technical solution, independent acquisition of multidimensional deformation data is achieved, which helps to analyze stress state more accurately.

[0038] Optionally, the pressurization component includes: The high-pressure pump station, which communicates with the control module, is used to provide the test medium; The high-pressure pipeline connects to the high-pressure pump station at one end and to the connecting component at the other end to connect the closed pressurization circuit, and is used to replenish or recover the test medium to the closed pressurization circuit. The fluid control valve assembly, connected in series with the high-pressure pipeline and communicating with the control module, is used to regulate the flow direction and flow rate of the test medium. The pressure detection unit is connected to the connection assembly to connect the sealed pressurization circuit and is used to detect the pressure of the sealed pressurization circuit.

[0039] By adopting the above technical solution, a complete hydraulic actuation and detection circuit was constructed, ensuring the execution capability of pressure control.

[0040] Optionally, the control module includes a PID control unit; The PID control unit is connected to both the strain monitoring module and the pressurization component. The PID control unit is configured to calculate the deviation between strain data and a preset plastic deformation threshold in real time, and dynamically adjust the output power of the pressurization component based on the deviation.

[0041] By adopting the above technical solution, adaptive control based on strain feedback was achieved, which significantly improved control accuracy and response speed.

[0042] Optionally, the control module includes an anomaly protection unit; The anomaly protection unit is communicatively connected to the strain monitoring module to monitor the strain difference between the first bend and the second bend. When the strain difference exceeds the preset safety tolerance range, the abnormal protection unit generates an emergency depressurization command and sends it to the pressurization component.

[0043] By adopting the above technical solution, hardware-level safety interlock protection is provided to prevent damage to equipment or workpieces due to control failure.

[0044] In summary, this application, through its combination of technical solutions, solves the technical problems of severe pressure fluctuations, excessive axial loads, and low processing efficiency revealed in the background technology, thereby achieving comprehensive technical advantages of stable pressure, self-balancing loads, and efficient and safe processing. Attached Figure Description

[0045] To more clearly illustrate the embodiments of this application, the relevant drawings will be briefly described below. It is understood that the drawings described below are only for illustrating some embodiments of this application, and those skilled in the art can obtain many other technical features and connections not mentioned herein based on these drawings.

[0046] Figure 1 This is a flowchart illustrating the steps of the self-reinforcing pipe bending method described in this application. Figure 2 This is a schematic diagram of the self-reinforcing device for bent pipes in this application; Figure 3 This is a partial cross-sectional schematic diagram of the self-reinforcing pipe bending device of this application in its working state; Figure 4 for Figure 3 A magnified view of a portion of the image; Figure 5 This is a partial explosion diagram of the self-reinforcing pipe bending treatment device of this application; Figure 6 This is a cross-sectional schematic diagram of the butt joint of the self-reinforcing pipe bending device of this application; Figure 7 This is a side view of the butt joint of the self-reinforcing pipe bending device of this application; Figure 8 This is a schematic diagram showing the installation position of the strain monitoring module of the self-reinforcing pipe bending device of this application; Explanation of reference numerals in the attached figures: 11. First bend; 12. Second bend; 2. Connecting assembly; 21. Butt joint; 211. Bidirectional sealing mandrel; 2111. First sealing groove; 2112. Second sealing groove; 212. Flow channel; 213. Connecting port; 214. Bolt hole; 22. Seal; 221. First sealing ring; 222. Second sealing ring; 23. Locking element; 231. First flange; 232. Second flange; 233. Threaded rod; 234. Locking nut; 3. Strain monitoring module; 31. Strain sensor; 4. Pressurization components; 41. High-pressure pump station; 42. High-pressure pipeline; 43. Fluid control valve assembly; 44. Pressure detection unit; 5. Control module; 6. Test fixtures; 7. Protective cover; 71. Camera. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0048] In the manufacturing and application of ultra-high pressure tubular reactors and heat exchangers, bends or elbows are key components that withstand extreme pressures (typically 200MPa to 800MPa) and high-temperature loads. Their structural integrity and fatigue life directly determine the safe operation of the entire equipment. To improve the load-bearing capacity of bends, a self-reinforcing process is often used in industry. This involves applying hydraulic pressure exceeding the material's yield strength to the inner wall of the bend, causing plastic deformation and creating a beneficial internal stress distribution along the wall thickness direction. This significantly reduces peak working stress and delays crack initiation.

[0049] In a widely used existing technology, the self-reinforcing treatment of bends is typically performed on a single, independent bend. Specifically, this method involves sealing both ends of a single bend with blind flanges to create a closed pressurized chamber. Subsequently, a test medium is injected into this chamber using an ultra-high pressure pump station, gradually increasing the pressure until the predetermined self-reinforcing pressure is reached.

[0050] However, this single-component, independent processing approach has significant technical limitations in principle. First, due to the relatively small internal volume of a single bend, even minor changes in the medium volume during high-pressure injection can cause drastic pressure fluctuations. This pressure instability makes it difficult to maintain a stable stress loading process on the inner wall of the bend, easily leading to uneven initial internal stress distribution, which in turn affects the overall effect of the self-reinforcing treatment. Second, to withstand ultra-high pressure and prevent the blind flange from flying out, this approach must rely on high-strength bolt sets with high torque preload to balance the enormous axial thrust. This not only places extremely high demands on the rigidity of the fixture and the reliability of the seals, increasing equipment costs and assembly difficulty, but also introduces potential safety hazards. Once the seal fails or the bolt preload is insufficient, serious accidents such as high-pressure fluid ejection or component ejection can easily occur.

[0051] Furthermore, the single-piece processing mode also leads to a bottleneck in production efficiency. Since only one workpiece can be processed per pressurization cycle, and the pressurization and depressurization processes must be extremely slow to cope with the risk of pressure fluctuations, this significantly prolongs the single processing cycle, resulting in low overall processing efficiency and making it difficult to meet the needs of large-scale industrial production.

[0052] To address the aforementioned issues of severe pressure fluctuations and excessive axial loads, those skilled in the art might readily consider increasing the volume of a single bend or improving the pump station's control algorithm to attempt to smooth the pressure curve. However, increasing the workpiece volume is limited by specific product specifications and is not a universal solution; while simply improving the control algorithm is insufficient to overcome the physical characteristic of small-volume systems being overly sensitive to changes in medium volume. Therefore, how to solve the technical challenges of poor pressure stability, high axial load risk, and low processing efficiency in the self-reinforcing treatment of ultra-high pressure bends from a system architecture perspective has become a crucial area requiring breakthroughs.

[0053] In view of this, the embodiments of this application aim to provide a method and apparatus for self-reinforcing bending pipes, in order to solve or at least partially alleviate the above-mentioned technical problems.

[0054] First Implementation Method This embodiment provides a bend self-reinforcing treatment device and a bend self-reinforcing treatment method based on the device. It focuses on how to combine two independent bends (i.e. elbows) into a mutually balanced closed pressurization system through a specific mechanical connection structure, thereby eliminating the huge axial thrust in the traditional single-piece processing mode at the physical level, and improving the stability of pressure control by utilizing the volume effect.

[0055] like Figure 2 As shown, in terms of device architecture, this bend-pipe self-reinforcing treatment device mainly includes a connecting component 2, a strain monitoring module 3, a pressurizing component 4, and a control module 5. The connecting component 2 is a key component in constructing the core physical form of this system, configured to connect the first bend 11 and the second bend 12 end-to-end in series. Specifically, the connecting component 2 allows the inner cavities of the first bend 11 and the second bend 12 to communicate with each other, thus forming a closed pressurizing circuit without blind plate end caps. This "double-bend interlocking" structural design ensures that when ultra-high internal pressure is applied, the axial thrust generated by the first bend 11 and the axial thrust generated by the second bend 12 are opposite in direction and cancel each other out at the connection interface, thereby achieving macroscopic self-balancing of the axial load.

[0056] To achieve the aforementioned end-to-end series connection and construct a closed loop, the connecting component 2 can include various specific mechanical implementations. In one specific embodiment, such as... Figure 3As shown, the connecting assembly 2 includes a mating joint 21, a sealing element 22, and a locking element 23. The mating joint 21 has a first connecting end and a second connecting end. The first connecting end is connected to the port of the first bend 11, and the second connecting end is connected to the port of the second bend 12. The sealing element 22 is respectively disposed at the first connecting end and the second connecting end, and is used to abut against the inner wall or end face of the first bend 11 and the second bend 12 to seal the connection gap and prevent leakage of the test medium.

[0057] like Figure 4 and Figure 6 As shown, further, in order to achieve a reliable seal without requiring a large preload under ultra-high pressure environments up to 800 MPa, the mating joint 21 can be configured as a bidirectional sealing mandrel 211. The bidirectional sealing mandrel 211 has an internal flow channel 212 that connects the first connecting end and the second connecting end, allowing smooth communication between the inner cavity of the first bend 11 and the inner cavity of the second bend 12 through the interior of the bidirectional sealing mandrel 211. A first sealing groove 2111 and a second sealing groove 2112 can be respectively formed on the outer wall of the bidirectional sealing mandrel 211, located near both ends. The sealing element 22 includes a first sealing ring 221 and a second sealing ring 222, which are respectively embedded in the first sealing groove 2111 and the second sealing groove 2112.

[0058] like Figure 5 As shown, in this embodiment, the locking element 23 may also include a first flange 231 and a second flange 232. The first flange 231 is fixedly connected to the port of the first bend 11 by welding or threading, and the second flange 232 is fixedly connected to the port of the second bend 12. The first flange 231 and the second flange 232 are detachably connected by multiple pre-tightening studs. The pre-tightening studs include a screw 233 and a locking nut 234. The screw 233 passes through the bolt hole 214 of the mating joint 21 to connect and fix the first flange 231 and the second flange 232. In this structure, a sealing element such as a lens gasket or a spiral wound gasket can be placed between the mating surfaces of the two flanges, and the initial seal is achieved by relying on the huge pre-tightening force of the studs. Although this method requires a large pre-tightening torque, its structure is simple and easy to assemble and disassemble quickly.

[0059] like Figure 6 and Figure 7As shown, the shape of the mating joint 21 in this embodiment corresponds to that of the first flange 231 and the second flange 232. The mating joint 21 has multiple bolt holes 214 corresponding to the connection holes of the first flange 231 and the second flange 232. During installation, the mating joint 21 is clamped by the first flange 231 and the second flange 232 and locked by screws 233 and lock nuts 234. The flow channel 212 inside the mating joint 21 extends through both ends of the mating joint 21. A connection port 213 communicating with the flow channel 212 is also provided on the surface of the mating joint 21. The connection port 213 is used to connect with the pipeline of the pressurizing assembly 4, thereby realizing the filling and recovery of test media inside the first bend 11 and the second bend 12 through the pressurizing assembly 4.

[0060] like Figure 1 As shown, in terms of the method flow, the bend self-reinforcing treatment method based on the above-mentioned device includes the following main steps. First, a docking series step is performed, that is, a connecting component 2 is set between the port of the first bend 11 and the port of the second bend 12; the port of the first bend 11 and the port of the second bend 12 are sealed and abutted by the connecting component 2 to construct a closed pressurized circuit.

[0061] Specifically, the first bend 11 and the second bend 12 are connected end-to-end through the aforementioned connecting assembly 2, so that their inner cavities are connected to form a sealed pressurized circuit. During this process, a bidirectional sealing mandrel 211 is provided, with sealing elements 22 at both ends and a flow channel 212 in the middle. The first end of the bidirectional sealing mandrel 211 is inserted into the port of the first bend 11, and a seal is formed between the sealing element 22 at the first end and the inner wall of the first bend 11. The second end of the bidirectional sealing mandrel 211 is inserted into the port of the second bend 12, and a seal is formed between the sealing element 22 at the second end and the inner wall of the second bend 12. The flow channel 212 connects the inner cavities of the first bend 11 and the second bend 12. The first flange 231 and the second flange 232 are aligned and tightened using a screw 233 and a locking nut 234.

[0062] The method includes a step of acquiring strain data of the first bend 11 and the second bend 12, specifically: strain monitoring modules 3 are set at multiple locations on the surface of the first bend 11 and the second bend 12, and the strain monitoring modules 3 are configured to monitor the strain data of the first bend 11 and the second bend 12 in real time.

[0063] Subsequently, the pressurization control step is executed. A test medium (e.g., water or hydraulic oil) is injected into the formed closed pressurization circuit through the pressurization component 4. Because the first bend 11 and the second bend 12 are connected in series, the total volume of the system is doubled compared to a single bend. According to fluid mechanics principles, at the same pumping flow rate, the increased volume results in a relatively slower pressure rise rate, reducing pressure spikes and fluctuations, making the pressurization process more stable and controllable.

[0064] During pressurization, control module 5 performs feedback control based on real-time strain data acquired by strain monitoring module 3. Specifically, control module 5 continuously monitors the strain data of the first bend 11 and the second bend 12, and controls pressurization component 4 to continuously inject the medium until the strain data reaches a preset plastic deformation threshold. This threshold is usually calculated based on the yield strength of the bend material, aiming to ensure that the inner wall of the bend produces an appropriate amount of plastic deformation (e.g., circumferential permanent strain does not exceed 2%), while the outer wall remains within the elastic range, thereby forming an ideal residual compressive stress distribution after depressurization.

[0065] The technical solution described in this embodiment eliminates the reliance on large blind flanges and ultra-high strength bolt assemblies through an interlocking structure of double-bend pipes connected end-to-end. This solves the problems of fixture design difficulties and safety hazards caused by excessive axial loads in traditional single-piece processing. The series connection of the double bends doubles the system volume, reduces pressure fluctuations during the pressure increase process, and improves the stability and uniformity of pressure control, thereby ensuring the consistency of self-reinforcing processing quality. This device allows for the simultaneous processing of two bends in one pressurization cycle, theoretically doubling production efficiency compared to single-piece processing, and significantly shortening the ultra-high pressure operating time per unit workpiece, reducing energy consumption and equipment wear risks.

[0066] Second Implementation Method Based on the architecture constructed in the aforementioned implementation method, this implementation method further refines and specifies the physical implementation form and deployment strategy of the strain monitoring module 3.

[0067] This embodiment provides a strain monitoring module 3 with high tracking accuracy and anti-interference capability. Its improvement lies in the use of a non-contact or flexible-fitting sensing unit, coupled with an adaptive sliding mounting bracket structure, to ensure that the sensor can accurately capture the true strain state of the pipe wall throughout the entire process of plastic expansion of the bent pipe.

[0068] In terms of method steps, the method steps of this embodiment include the step of obtaining strain data of the first bend 11 and the second bend 12, that is, strain monitoring modules 3 are set at multiple locations on the surface of the first bend 11 and the second bend 12, and the strain monitoring modules 3 are configured to monitor the strain data of the first bend 11 and the second bend 12 in real time.

[0069] Specifically, at least one first monitoring section is selected on the outer wall of the first bend 11, and at least one second monitoring section is selected on the outer wall of the second bend 12. Strain monitoring module 3 measuring points are arranged on the first monitoring section and the second monitoring section respectively to collect strain signals at each measuring point, thereby reflecting the deformation of key parts of the bend.

[0070] like Figure 8 As shown, in one embodiment, strain acquisition points are set at positions of 0°, 90°, 180°, and 270° along the circumferential direction of the first and second monitoring sections, respectively. The circumferential and axial strain data of the first bend 11 and the second bend 12 are monitored through these strain acquisition points. This arrangement can identify possible elliptic or bending deformations in the bends, improving the comprehensiveness of the monitoring.

[0071] In terms of specific structure, the strain monitoring module 3 includes a sensing unit array, a signal transmission component, and a flexible fixing base. The sensing unit array consists of several distributed strain sensing nodes. In a preferred embodiment, the sensing unit array includes multiple strain sensors 31; the strain sensors 31 are attached to the outer surfaces of the first bend 11 and the second bend 12 to collect strain data of the outer surfaces during the pressurization process.

[0072] These strain sensors 31 can be miniature fiber optic grating (FBG) sensors. FBG sensors are characterized by their small size, light weight, resistance to electromagnetic interference, and ease of multiplexing and cascading. For example, multiple fiber optic gratings etched with different center wavelengths can be cascaded on a single optical fiber and uniformly distributed circumferentially along the outer wall of the first bend 11 and the second bend 12, forming a monitoring network covering the critical stress zone. This configuration allows for the placement of a measuring point, for example, every 45 or 90 degrees, thereby comprehensively capturing the ellipticization trend and local strain concentration phenomena of the bend cross-section during the pressurization process.

[0073] In one embodiment, see Figure 2 and Figure 8 As shown, strain sensors 31 are distributed at intervals along the circumferential direction of the outer surface of the first bend 11 and the second bend 12; preferably, the arrangement positions of strain sensors 31 include at least 0° position, 90° position, 180° position and 270° position.

[0074] The strain sensor 31 may include a circumferential strain gauge and an axial strain gauge; the circumferential strain gauge is used to monitor the circumferential expansion deformation of the first bend 11 and the second bend 12; the axial strain gauge is used to monitor the axial elongation deformation of the first bend 11 and the second bend 12.

[0075] As an alternative implementation, the sensing unit can also be a miniature resistance strain gauge based on semiconductor materials, but its surface is covered with a flexible polymer protective layer (such as polyimide or silicone). This flexible protective layer not only provides insulation and moisture protection, but more importantly, it gives the strain gauge a certain degree of ductility, allowing it to follow the plastic deformation of the bent tube surface without breaking or delaminating.

[0076] To stably attach the aforementioned sensing unit to the surface of the bend, this embodiment designs a flexible fixing base. This flexible fixing base can employ a high-strength elastic strap or a magnetic flexible patch structure. For example, the elastic strap can be made of woven aramid fiber, with its inner side coated with a high-friction coefficient anti-slip coating. During assembly, the flexible base with the attached sensing unit is wrapped around and fitted against the outer wall of the bend, and secured using the self-tightening force of the elastic strap. This fixing method allows the base to undergo synchronous radial displacement and tangential extension as the bend diameter expands due to increased internal pressure, avoiding the sensor's suspension or damage due to compression caused by the inability of traditional rigid clamps to follow deformation.

[0077] To address potential noise interference issues during long-distance signal transmission, the signal transmission assembly is configured to include a locally located signal conditioning unit. This unit can be secured to a rack position near the bend in the tube, but without significant displacement due to the bend, using either snap-fit ​​or magnetic attachment. Signal lines (such as optical fibers or shielded wires) extending from the sensing nodes on the bend are connected to the conditioning unit via a stress-relief loop structure. Specifically, after leaving the bend surface, the signal line first forms a buffer loop of appropriate radius before entering the fixed-end interface. When the bend expands, the buffer loop changes shape to absorb the displacement, ensuring that the tension transmitted to the sensing nodes is almost zero, preventing false strain readings caused by cable tension.

[0078] In terms of functionality, the strain monitoring module 3 is configured to demodulate and output the wavelength change or resistance change at each measuring point in real time, and convert it into micro-strain values ​​(με) which are then transmitted to the control module 5. Due to its distributed array design, this module not only provides the maximum strain value at a single point for safe use, but also calculates the rate of change of the roundness of the bend's cross-section by comparing data from measuring points at different orientations. For example, if the strain readings at two measuring points at approximately 180 degrees apart show a significant increase in difference, it indicates that the bend may be experiencing non-uniform plastic flow or material defects.

[0079] like Figure 2 As shown, in one embodiment, a protective cover 7 can be provided, and the first bend 11 and the second bend 12 are installed on the test fixture 6 inside the protective cover 7 to ensure the safety of the test and prevent dangers such as material splashing caused by pipe rupture and explosion. Alternatively, the test fixture 6 can be placed in a pit, which also serves a safety protection function.

[0080] Multiple cameras 71 can be installed inside the protective cover 7. The cameras 71 are electrically connected to the control system 5 to observe the experimental status in real time. They can provide information on the macroscopic changes of the first bend 11 and the second bend 12 to assist staff in making timely adjustments.

[0081] The strain monitoring module 3 described in this embodiment, through the application of fiber optic gratings or flexible strain gauges, significantly improves the sensor's survivability under extreme high pressure and plastic deformation environments, solving the problems of easy damage and difficult maintenance of traditional rigid sensors. The coordinated design of the flexible fixed base and stress relief ring eliminates the coupling interference of mechanical displacement on the measurement signal, ensuring that the acquired strain data purely reflects the material deformation of the pipe wall, thus improving the accuracy and response speed of closed-loop control. The distributed array layout provides rich spatial dimension information, enabling the system to identify local defects and monitor deformation uniformity, providing detailed data support for quality traceability and process optimization in ultra-high pressure self-reinforcing processes. This monitoring scheme forms the sensing foundation for ensuring the safe and efficient operation of the mechanical architecture in the first embodiment.

[0082] Third Implementation Method Based on the above implementation method, this implementation method further improves the control dimension of the system and provides an intelligent closed-loop control scheme based on real-time strain feedback.

[0083] The bend self-reinforcing device provided in this embodiment, based on the hardware of the first embodiment, deepens the functional integration of the strain monitoring module 3, the pressurization component 4, and the control module 5. Its improvement lies in the introduction of a multi-level dynamic pressurization strategy and a real-time strain-pressure coupling verification mechanism, replacing the traditional single pressure threshold control or open-loop time control mode.

[0084] like Figure 2 As shown, the specific device configuration includes a test fixture 6 for mounting and fixing two sets of bends. The pressurization assembly 4 includes a high-pressure pump station 41, a high-pressure pipeline 42, a fluid control valve assembly 43, and a pressure detection unit 44. The high-pressure pump station 41 is communicatively connected to the control module 5 and is used to provide the test medium. One end of the high-pressure pipeline 42 is connected to the high-pressure pump station 41, and the other end is connected to the connection port 213 of the connection assembly 2 to connect the closed pressurization circuit, used to replenish or recover the test medium into the closed pressurization circuit. The fluid control valve assembly 43 is connected in series with the high-pressure pipeline 42 and is communicatively connected to the control module 5, used to regulate the flow direction and flow rate of the test medium. The pressure detection unit 44 is connected to the connection assembly 2 to connect the closed pressurization circuit and is used to detect the pressure of the closed pressurization circuit.

[0085] The strain monitoring module 3 is configured to include at least two sets of high-precision strain sensors 31. The first set of strain sensors 31 is arranged at the point of maximum curvature on the outer wall of the first bend 11 (i.e., outside the neutral layer of the bend), and the second set of strain sensors 31 is arranged at the corresponding position on the second bend 12. Preferably, each set of strain sensors 31 may include multiple measuring points arranged circumferentially along the bend to capture the uniformity of strain distribution on the cross-section of the bend. These sensors may be resistive strain gauges, fiber optic grating sensors, or non-contact laser extensometers, and they are configured to acquire circumferential and axial strain data of the bend in real time during the pressurization process, and convert analog signals into digital signals for transmission to the control module 5.

[0086] Control module 5 internally stores the theoretical strain-pressure curve and safety envelope calculated based on the mechanical properties of the target bend material. This control module 5 is programmed to execute the following core logic: In the initial pressurization phase, the pressurization component is controlled to linearly increase the pressure at a first rate (e.g., 5 MPa / s). At this time, the material is in the elastic deformation stage. Control module 5 compares the measured strain with the theoretical elastic strain in real time. If the deviation exceeds the preset elastic tolerance (e.g., ±5%), it is determined that the bend has an initial defect or clamping eccentricity, and a pause or depressurization protection is immediately triggered.

[0087] When the measured strain reaches the critical strain value corresponding to the material's yield point, control module 5 automatically switches to the second rate (e.g., 0.5 MPa / s or lower) for slow pressure increase. This stage is the critical period for plastic deformation propagation; slow pressure increase helps allow dislocation movement within the material to proceed fully, reducing local stress concentration. During this process, control module 5 continuously monitors the ratio of the strain rate increase to the pressure rate increase (i.e., the reciprocal of the tangent modulus).

[0088] As a specific implementation example, control module 5 executes a stepped pressure holding subroutine. During the pressurization process, for each preset pressure step (e.g., 50 MPa), control module 5 instructs pressurization component 4 to stop pressurizing and hold the pressure for a preset time (e.g., 30 seconds). During the pressure holding period, if the strain reading continues to increase over time (creep phenomenon) and the rate of increase exceeds a threshold, it indicates that the material has entered an unstable plastic flow state. Control module 5 will determine that the current pressure is close to its limit and will no longer continue pressurizing, or even actively release a small amount of pressure to stabilize the state. Conversely, if the strain reading stabilizes rapidly during the pressure holding period, it instructs to continue the next stage of pressurization.

[0089] The final pressure relief trigger condition no longer depends solely on the preset pressure value, but is strictly locked to the measured strain value. The control module 5 is configured to immediately instruct the pressurization component 4 to stop pressurizing and start the controlled pressure relief procedure when the reading of any strain sensor 31 reaches the preset plastic deformation threshold (e.g., the circumferential permanent strain value corresponding to the yielding of the inner wall and the outer wall still being within the elastic range, such as 0.5% to 1.5%).

[0090] While the aforementioned embodiments have provided a double-bend interlocking structure capable of withstanding ultra-high axial loads and a monitoring module capable of acquiring deformation data in real time, simply using a method of continuous pressurization up to a threshold may be insufficient to address the asynchronous deformation issues caused by differences in the material properties of the two bends. For example, in a closed pressurization circuit where the first bend 11 and the second bend 12 are connected in series, if the yield strength of one bend is slightly lower than that of the other, during rapid pressurization, the first bend may enter the plastic deformation stage first, while the other bend remains in the elastic stage. If this asynchronous deformation is not identified and intervened in time, it may lead to excessive strain in the bend that yields first, while the other bend's reinforcement effect is insufficient, thus affecting the consistency of the overall processing quality. Furthermore, direct pressure application may also generate pressure spikes due to fluid inertia, impacting the seals.

[0091] To address the stability and consistency issues in the aforementioned process control, the control module 5 in this embodiment can be configured to perform multi-stage pressurization operations and intermediate pressure holding verification logic. Specifically, the control module 5 is communicatively connected to the pressurization component 4, controlling the pressurization component 4 to increase the pressure in the closed pressurization circuit to the target pressure in stages, rather than continuously increasing the pressure all at once. Before the pressure rises to the target pressure point corresponding to the plastic deformation threshold of the first bend 11 and the second bend 12, the control module 5 can perform an intermediate pressure holding step.

[0092] During the intermediate pressure holding step, the control module 5 acquires the strain data of the first bend 11 and the second bend 12 collected by the strain monitoring module 3, and compares the data deviations between the two. If the deviation of the strain data exceeds the preset consistency tolerance, the control module 5 can adjust the pressure increase parameters, such as reducing the pressure increase rate in the next stage, or directly depressurizing the closed pressurization circuit to wait for the slower-deforming bend to catch up. In other words, to prevent misjudgment due to sensor failure, the control module also executes redundant verification logic: if the difference in strain data between the two bends exceeds the allowable range (e.g., 10%), or if the correspondence between strain data and pressure data deviates significantly from the theoretical curve, the system will determine it as an abnormal condition and execute emergency depressurization. This process intervention mechanism ensures the synchronization of the two bends during the plastic deformation stage, avoiding uneven reinforcement effects caused by individual differences.

[0093] Furthermore, to achieve high-precision closed-loop control, the control module 5 may include a PID control unit. This PID control unit is signal-connected to both the strain monitoring module 3 and the pressurization component 4, and is configured to calculate the deviation between the strain data and a preset plastic deformation threshold in real time, and dynamically adjust the output power of the pressurization component based on this deviation. Through the PID algorithm, the system can fine-tune the pump station output according to real-time strain feedback; for example, it can automatically reduce the valve opening when the strain growth rate is too fast, thereby smoothing the pressure curve.

[0094] Meanwhile, the control module 5 may also include an anomaly protection unit, which is communicatively connected to the strain monitoring module 3 to monitor the strain difference between the first bend 11 and the second bend 12. When the strain difference exceeds the preset safety tolerance range, the anomaly protection unit generates an emergency pressure relief command and sends it to the pressurization component 4, triggering the fluid control valve group 43 to quickly open the pressure relief passage. After reaching the target pressure and completing the pressure holding process, the control module 5 can also perform a staged pressure relief operation, gradually reducing the pressure in the closed pressurization circuit from the target pressure to atmospheric pressure, rather than directly venting the system.

[0095] Compared to a simple hardware architecture, the control strategy and pressure cycling process described in this embodiment improve the intelligence and safety of the self-reinforcing processing. Through multi-stage pressure boosting and intermediate pressure holding consistency verification, the risk of asynchronous deformation due to individual differences in the bends is effectively eliminated, ensuring that both the first bend 11 and the second bend 12 achieve a uniform and expected residual stress distribution. The combination of PID closed-loop control and the anomaly protection unit not only suppresses the impact of pressure fluctuations on the sealing structure but also provides hardware-level safety interlocks to prevent workpiece failure due to control malfunction or local overload. The staged pressure relief operation avoids the deterioration of residual stress distribution or crack initiation that may be caused by rapid pressure relief. This refined process control scheme, combined with the mechanical structure and sensor network of the aforementioned embodiment, constitutes a complete, reliable, and efficient bend self-reinforcing processing system, particularly suitable for high-pressure pipeline component manufacturing scenarios with extremely high requirements for processing quality consistency.

[0096] This embodiment further provides a specific execution flow for a self-reinforcing pipe bending process. The core of this embodiment lies in transforming an abstract control strategy into a sequence of specific steps executable by the control system. Through refined process control, it ensures that the self-reinforcing process achieves a stable and consistent strengthening effect in pipe bending processes of different batches and with different material properties.

[0097] The self-reinforcing treatment method for the bent pipe is mainly executed by the control module 5 in coordination with the pressurization component 4 and the strain monitoring module 3. Its process can cover the parameter initialization stage, the elastic loading monitoring stage, the plastic deformation control stage, and the depressurization and data processing stage.

[0098] During the parameter initialization phase, control module 5 first receives operation instructions and acquires the basic material parameters of the bend to be processed. These parameters may include, for example, the material grade, nominal yield strength, elastic modulus, and target hardening coefficient. Based on this input data, control module 5 internally calls a pre-stored mechanical model to calculate and generate a theoretical strain-pressure reference curve. This curve defines the ideal range of strain that the bend should be under different pressure levels. Simultaneously, control module 5 performs zero-point calibration on strain monitoring module 3 to eliminate initial deviations in the sensor due to installation prestress or ambient temperature, ensuring the accuracy of the reference data for subsequent acquisitions.

[0099] Upon entering the elastic loading monitoring phase, control module 5 instructs pressurization component 4 to inject the test medium into the closed pressurization circuit at a first pressurization rate. In a specific embodiment, the first pressurization rate can be set to a relatively fast value, such as 5 MPa / s to 10 MPa / s, to shorten the time consumed in the non-plastic deformation stage and improve overall processing efficiency. During this process, control module 5 collects real-time strain data fed back by strain monitoring module 33 and performs correlation analysis with real-time pressure data. Control module 5 is configured to calculate the ratio of real-time strain to real-time pressure, i.e., the current structural stiffness coefficient. If this coefficient remains constant within the preset pressure range or deviates from the value derived from the theoretical elastic modulus within the allowable range, the bend is determined to be in a normal elastic deformation state. Conversely, if abnormal fluctuations in the stiffness coefficient are detected, control module 5 can determine that there is a risk of leakage or loose clamping and automatically trigger a pause or emergency depressurization procedure. This online verification mechanism effectively avoids potential safety accidents that may be caused by forcibly entering the plastic stage when the equipment is in an abnormal state.

[0100] When the real-time strain data reaches the preset plastic deformation threshold, i.e., the yield critical value based on the tube material, the processing method automatically transitions to the plastic deformation control stage. This yield critical value can be the theoretical strain value calculated based on the material's nominal yield strength, or it can be the actual yield point dynamically identified by monitoring points where the slope of the strain-pressure curve changes significantly. Once this stage is reached, the control module 5 immediately adjusts the operating state of the pressurization component 4, reducing the pressurization rate to a second pressurization rate. The second pressurization rate is significantly lower than the first pressurization rate, for example, it can be 0.5 MPa / s to 1 MPa / s. The purpose of reducing the pressurization rate is to slow down the rate of plastic flow, making the lattice slip and dislocation movement within the material more complete and uniform, preventing localized adiabatic temperature rise or deformation concentration caused by excessively rapid loading.

[0101] During the plastic deformation control stage, the processing method can also include a stepped pressure holding sub-step. Specifically, control module 5 maintains the current pressure constant for a preset period of time, such as 30 to 60 seconds, after each preset pressure increase, for a predetermined step size, such as 50 MPa. During the pressure holding period, control module 5 continuously monitors the trend of strain readings. If the strain reading continues to increase over time and the rate of increase exceeds a set threshold, it indicates that the material has undergone significant creep or entered an unstable plastic flow state. Control module 5 will then determine that the current pressure is close to the material's limit and will no longer increase the pressure. If the strain reading stabilizes rapidly during the pressure holding period, it will instruct the next stage of pressure increase. This stepped loading strategy provides a time window for stress relaxation in the material, which helps to release local peak stresses and improve the uniformity of the overall deformation of the bend.

[0102] The termination condition of the processing method is strictly locked to the measured strain value. The control module 5 is configured to continuously compare the real-time strain with a preset plastic deformation threshold. This plastic deformation threshold is typically set to a value that ensures the inner wall of the bend undergoes appropriate plastic deformation while the outer wall remains within the elastic range, for example, corresponding to a total strain value of 0.5% to 1.5% of the circumferential permanent strain. When the strain data at any monitoring point reaches this threshold, the control module 5 immediately instructs the pressurization component 4 to stop pressurizing and initiates the depressurization and data processing phase.

[0103] During the depressurization and data processing phase, control module 5 controls pressurization component 4 to release the loop pressure at a predetermined depressurization rate. Preferably, the depressurization process can be divided into two intervals: rapid depressurization and slow depressurization, to prevent water hammer effects caused by excessively rapid pressure release from impacting the pipe wall. After the pressure is completely released, control module 5 reads the residual strain data recorded by the strain monitoring module. Based on this residual strain data and the pre-input material constitutive model, control module 5 can further estimate the residual compressive stress distribution on the inner wall of the bend. For example, by calculating the elastic recovery during the unloading process, the residual stress level left by plastic deformation can be inferred. In addition, control module 5 packages and stores key data from this processing process, including the maximum pressure value, the time to reach the threshold, the strain curves at each stage, and the final residual stress estimate, into a quality traceability archive. This data can be used for subsequent process optimization or as an attachment to the product certificate of conformity.

[0104] The control execution method described in this embodiment balances processing efficiency and deformation quality through staged pressure ramp rate control, ensuring rapid passage through the elastic stage while guaranteeing uniform deformation in the plastic stage. Online stiffness verification and a stepped pressure holding mechanism provide multiple safety safeguards, enabling timely identification of material defects or equipment malfunctions and reducing the risk of pipe bursts. Precise termination control based on measured strain and residual stress estimation eliminates fluctuations in strengthening effects caused by batch-to-batch material variations, achieving the digitization and standardization of the pipe bending self-reinforcing process and providing reliable methodological support for large-scale industrial applications. This method, closely integrated with the aforementioned device embodiment, constitutes a complete pipe bending self-reinforcing technology solution.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for self-reinforcing bent pipes, characterized in that, include: The first bend and the second bend are connected end to end in series, so that the inner cavity of the first bend and the inner cavity of the second bend are interconnected to form a closed pressurized circuit. Obtain strain data for the first bend and the second bend; Based on the strain data, test medium is injected into the closed pressurization circuit until the strain data reaches a preset plastic deformation threshold derived from the yield strength of the pipe material.

2. The self-reinforcing treatment method for bent pipes according to claim 1, characterized in that, The step of connecting the first bend and the second bend end to end in series includes: A connecting component is provided between the port of the first bend and the port of the second bend; The connection assembly is used to seal and abut the ports of the first bend and the second bend to form the closed pressurized circuit.

3. The self-reinforcing treatment method for bent pipes according to claim 2, characterized in that, The step of sealing and abutting the port of the first bend and the port of the second bend through the connecting assembly includes: A bidirectional sealing mandrel is provided, wherein sealing elements are respectively provided at both ends of the bidirectional sealing mandrel, and a connecting channel is provided in the middle; The first end of the bidirectional sealing mandrel is inserted into the port of the first bend, and a seal is formed between the sealing element located at the first end and the inner wall of the first bend. The second end of the bidirectional sealing mandrel is inserted into the port of the second bend, and a seal is formed between the sealing element located at the second end and the inner wall of the second bend. The connecting channel connects the inner cavity of the first bend and the inner cavity of the second bend.

4. The self-reinforcing treatment method for bent pipes according to claim 1, characterized in that, The step of obtaining strain data for the first bend and the second bend includes: Strain monitoring modules are installed at multiple locations on the surfaces of the first bend and the second bend, and the strain monitoring modules are configured to monitor the strain data of the first bend and the second bend in real time.

5. The self-reinforcing treatment method for bent pipes according to claim 4, characterized in that, The step of installing strain monitoring modules at multiple locations on the surfaces of the first bend and the second bend includes: At least one first monitoring section is selected on the outer wall of the first bend, and at least one second monitoring section is selected on the outer wall of the second bend; The strain monitoring module is arranged at measurement points on the first and second monitoring sections respectively to collect strain signals at each measurement point.

6. The self-reinforcing treatment method for bent pipes according to claim 5, characterized in that, The step of arranging the stress-strain detection device measuring points on the first monitoring section and the second monitoring section respectively includes: Strain acquisition points are set at 0°, 90°, 180° and 270° along the circumferential direction of the first monitoring section and the second monitoring section, respectively; The circumferential strain data and axial strain data of the first bend and the second bend are monitored through the strain acquisition points, respectively.

7. The self-reinforcing treatment method for bent pipes according to claim 1, characterized in that, The process of acquiring the strain data of the first bend and the second bend also includes: In real time, it is determined whether the rate of change of the strain data exceeds a preset rate of change threshold, or whether the deviation of the strain data between the first bend and the second bend exceeds a preset deviation threshold. If the judgment result is yes, then the pressure reduction operation is performed on the sealed pressurization circuit.

8. The self-reinforcing treatment method for bent pipes according to claim 1, characterized in that, The step of injecting the test medium into the closed pressurization circuit based on the strain data includes: Perform multi-stage pressurization operations to gradually increase the pressure in the closed pressurization circuit to the target pressure. After the pressure reaches the target pressure, a pressure holding operation is performed to maintain the pressure at a constant value for a preset time.

9. The self-reinforcing treatment method for bent pipes according to claim 8, characterized in that, The process of performing the multi-stage boost operation also includes: An intermediate pressure holding step is performed before the pressure rises to the target pressure point corresponding to the plastic deformation threshold of the first bend and the second bend; During the intermediate pressure holding step, the strain data of the first bend is compared with the strain data of the second bend; If the strain data of the two exceed the preset consistency tolerance, the pressure boosting parameters are adjusted or the pressure reduction operation is performed on the sealed pressurization circuit.

10. The self-reinforcing treatment method for bent pipes according to claim 9, characterized in that, After the pressure holding operation step, the following is also included: Perform a staged depressurization operation to reduce the pressure in the closed pressurization circuit from the target pressure to atmospheric pressure.

11. A self-reinforcing device for bent pipes, characterized in that, include: A connecting component is used to connect a first bend and a second bend, so as to connect the first bend and the second bend end to end in series, so that the inner cavity of the first bend and the inner cavity of the second bend are interconnected to form a closed pressurized circuit. A strain monitoring module is used to connect the first bend and the second bend to obtain strain data of the first bend and the second bend. A pressurizing component, connected to the connecting component, is used to inject test medium into the closed pressurizing circuit; The control module is communicatively connected to both the strain monitoring module and the pressurization component, and is configured to control the pressurization component to perform an injection operation based on the strain data until the strain data reaches a preset plastic deformation threshold.

12. The self-reinforcing device for bent pipes according to claim 11, characterized in that, The connection component includes: A butt joint has a first connecting end and a second connecting end, wherein the first connecting end is connected to the port of the first bend and the second connecting end is connected to the port of the second bend; A sealing element is respectively disposed at the first connecting end and the second connecting end, and is used to abut against the inner wall of the first bend and the second bend to seal the connection gap; A locking component connects the first bend, the second bend, and the mating joint, and is used to fix the mating joint between the first bend and the second bend.

13. The self-reinforcing device for bent pipes according to claim 12, characterized in that, The mating joint includes a bidirectional sealing mandrel; the bidirectional sealing mandrel has a flow channel inside, which connects the first connecting end and the second connecting end, so that the inner cavity of the first bend and the inner cavity of the second bend are interconnected to form a closed pressurized circuit; the outer wall of the bidirectional sealing mandrel has a first sealing groove and a second sealing groove, which are located at the first connecting end and the second connecting end, respectively. The sealing element includes a first sealing ring and a second sealing ring; the first sealing ring is embedded in the first sealing groove and presses against the inner wall of the first bend under the pressure of the test medium to seal the gap between the first connecting end and the first bend; the second sealing ring is embedded in the second sealing groove and presses against the inner wall of the second bend under the pressure of the test medium to seal the gap between the second connecting end and the second bend.

14. The self-reinforcing device for bent pipes according to claim 12, characterized in that, The locking element includes a first flange and a second flange; The first flange is fixedly connected to the port of the first bend, and the second flange is fixedly connected to the port of the second bend; The first flange and the second flange are detachably connected by pre-tightening studs.

15. The self-reinforcing device for bent pipes according to any one of claims 11 to 14, characterized in that, The strain monitoring module includes multiple strain sensors; The strain sensor is attached to the outer surface of the first bend and the second bend to collect strain data of the outer surface during the pressurization process.

16. The self-reinforcing device for bent pipes according to claim 15, characterized in that, The strain sensors are distributed at intervals along the circumferential direction of the outer surface of the first bend and the second bend. The strain sensor can be positioned at least at 0°, 90°, 180° and 270°.

17. The self-reinforcing device for bent pipes according to claim 15, characterized in that, The strain sensor includes: a circumferential strain gauge and an axial strain gauge; Circumferential strain gauges are used to monitor the circumferential expansion and deformation of the first bend and the second bend; Axial strain gauges are used to monitor the axial elongation deformation of the first bend and the second bend.

18. The self-reinforcing device for bent pipes according to any one of claims 11 to 14, characterized in that, The pressurization component includes: A high-pressure pump station, which is communicatively connected to the control module, is used to provide the test medium; A high-pressure pipeline, with one end connected to the high-pressure pump station and the other end connected to the connecting assembly, is used to connect the closed pressurization circuit and to replenish or recover the test medium to the closed pressurization circuit. A fluid control valve assembly is connected in series in the high-pressure pipeline and communicates with the control module to adjust the flow direction and flow rate of the test medium. A pressure detection unit is connected to the connection assembly to connect the sealed pressurization circuit and is used to detect the pressure of the sealed pressurization circuit.

19. The self-reinforcing device for bent pipes according to any one of claims 11 to 14, characterized in that, The control module includes a PID control unit; The PID control unit is connected to the strain monitoring module and the pressurization component respectively; The PID control unit is configured to calculate the deviation between the strain data and the preset plastic deformation threshold in real time, and dynamically adjust the output power of the pressurization component based on the deviation.

20. The self-reinforcing device for bent pipes according to any one of claims 11 to 14, characterized in that, The control module includes an anomaly protection unit; The abnormal protection unit is communicatively connected to the strain monitoring module and is used to monitor the strain difference between the first bend and the second bend. When the strain difference exceeds the preset safety tolerance range, the abnormal protection unit generates an emergency depressurization command and sends it to the pressurization component.

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