Pipeline non-transmission-stopping overhauling method and device based on pressure balance regulation and control

Abstract

The invention discloses a pipeline non-transmission-stopping overhauling method and device based on pressure balance regulation and control, and relates to the technical field of pipeline maintenance. The pipeline non-transmission-stopping overhauling device comprises a plugging system, a multi-mode monitoring system, a holographic control module and a modular operation module; the plugging system comprises a liquid nitrogen freezing plugging assembly and an intelligent double-air-bag plugging assembly which are sequentially arranged in the axial direction of the two ends of a pipeline maintenance section and used for constructing multiple isolation barriers acting in sequence. Through the synergistic effect of liquid nitrogen freezing plugging and intelligent double-air-bag plugging, a multiple isolation barrier of dynamic air bag buffering and pressure stabilizing and solid ice plug main pressure bearing is constructed, and safe and efficient overhauling operation is carried out under the condition that pipeline conveying stopping and medium emptying are completely not needed; and huge production interruption loss caused by a traditional maintenance method is thoroughly avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline repair, in particular to a pipeline repair method and device based on pressure balance regulation. BACKGROUND

[0002] In the industrial fields of petroleum, chemical industry, municipal water supply and drainage, etc., pipeline system is the core infrastructure for transporting various media (such as crude oil, natural gas, chemical raw materials, water, etc.), and its long-term, safe and stable operation is crucial. However, defects will inevitably occur in the service process of the pipeline due to corrosion, wear, external force damage or material aging, and regular maintenance and emergency repair are the key links to ensure the integrity and safe operation of the pipeline system.

[0003] At present, the conventional technical means for pipeline repair mainly relies on stoppage and emptying operation. That is, before the implementation of repair, the target pipe section must be isolated from the system and the internal medium must be completely emptied. This method has the following inherent disadvantages:

[0004] Poor economy: For the petroleum, chemical and other industries with continuous production, pipeline stoppage means production interruption, which will directly lead to huge loss of production capacity and decline of economic benefits.

[0005] Complex operation and long cycle: The processes of emptying, purging, and replacing are complicated, which greatly prolongs the overall duration of the repair operation.

[0006] Therefore, the present application proposes a pipeline repair device based on pressure balance regulation. SUMMARY

[0007] The purpose of the present application is to provide a pipeline repair device based on pressure balance regulation to solve the problems of poor economy, complex operation and long cycle caused by the conventional technical means for pipeline repair mainly relying on stoppage and emptying operation as mentioned in the background.

[0008] In order to achieve the above purpose, the present application provides the following technical scheme:

[0009] A pipeline repair device based on pressure balance regulation, comprising a plugging system, a multi-modal monitoring system, a holographic control module and a modular operation module;

[0010] The plugging system comprises a liquid nitrogen freezing plugging assembly and an intelligent double air bag plugging assembly arranged axially along both ends of the pipeline repair section in sequence, for building a multi-isolation barrier acting in sequence;

[0011] The liquid nitrogen freezing plugging assembly comprises a frozen clamp for covering the outer wall of the pipeline and a liquid nitrogen tank communicating with the frozen clamp, for forming and monitoring a pressure-bearing ice plug on the inner wall of the pipeline in real time by gradient cooling process, constituting a first-stage main plugging;

[0012] The intelligent double-balloon occlusion assembly comprises an occluder support which can be positioned inside the pipeline, and a first annular sealing balloon and a second pressure regulating balloon arranged based on the support, the first annular sealing balloon is arranged around the peripheral wall of the occluder support, and is used to form an interference fit with the inner wall of the pipeline after inflation, the second pressure regulating balloon is arranged in the hollow part of the occluder support, and is communicated with the inner cavity of the pipeline through a pressure regulating hole penetrating through the end face of the occluder support, the second pressure regulating balloon is communicated with the pressure balance regulation system, and constitutes a second stage dynamic occlusion.

[0013] Optionally, the freezing clamp is a openable and closable ring structure composed of a lower ring base and a plurality of modular side ring seats, the lower ring base is symmetrically connected with the side ring seats on both sides through hinges, and adjacent side ring seats are also connected through hinges, and the abutting end faces of the lower ring base, the side ring seat and the adjacent side ring seat are all provided with V-shaped sealing elastic strips.

[0014] Optionally, the liquid nitrogen freezing occlusion assembly further comprises a base supporting the freezing clamp and a hydraulic cylinder driving the opening and closing of the freezing clamp, when the freezing clamp is driven to close by the hydraulic cylinder, the middle part of the two side ring seats abutting against each other forms a nitrogen inlet, the outside of the nitrogen inlet is sleeved with a clamping ring, and the side part of the lower ring base and the plurality of modular side ring seats contacting the peripheral wall of the pipeline is provided with a clamping block.

[0015] Optionally, the liquid nitrogen tank is communicated with the nitrogen inlets of the two side freezing clamps through a nitrogen conveying pipeline, and is connected with the outlet at the bottom of the freezing clamp through a liquid nitrogen recovery pipeline to form a cold energy recovery loop.

[0016] Optionally, the intelligent double-balloon occlusion assembly is introduced into the pipeline through a sealing pipe, the sealing pipe is integrated with a positive and negative bin and a gate valve, which are used to realize dynamic isolation and balance of the pressure inside and outside the pipeline during the insertion and extraction of the occlusion assembly, the positive and negative bin is provided with a positioning driving element, the positioning driving element is in transmission connection with the occluder support, which is used to drive the axial feeding of the intelligent double-balloon occlusion assembly in the pipeline to realize the precise control of the occlusion position, and a pressure gauge is arranged on the pressure pipeline connected with the positive and negative bin.

[0017] Optionally, the pressure balance regulation system comprises a controller and a high-pressure gas source, the controller is connected with the second pressure regulating balloon through a gas path, can sense the change of the medium pressure in the pipeline in real time through the pressure regulating hole, and dynamically adjusts the internal pressure of the second pressure regulating balloon based on the PID closed-loop control algorithm, so that the sealing pressure of the balloon always adaptively tracks and is slightly higher than the medium pressure in the pipeline, and dynamic pressure balance and sealing enhancement are realized.

[0018] Optionally, the multi-modal monitoring system is integrated with a distributed temperature sensor array located in the freeze clamp, a pipe pressure sensor arranged on the pipe wall for monitoring medium pressure, a gas bag pressure sensor built in the gas circuit of the first and second pressure regulating gas bags, and a vibration sensor arranged outside the freeze clamp and the sealing pipe, the system is configured to monitor the sealing state in real time and feed the monitoring data to the holographic control module for intelligent decision-making.

[0019] Optionally, the holographic control module is integrated with a gesture-voice dual-mode interaction interface and connected with the liquid nitrogen freeze sealing assembly, the intelligent double-gas bag sealing assembly, the pressure balance regulation system and the multi-modal monitoring system as a central processing unit, the holographic control module outputs cooperative control instructions based on the fusion data of the multi-modal monitoring system to uniformly schedule the whole process of sealing establishment, dynamic pressure regulation, maintenance operation and unsealing recovery.

[0020] Optionally, the modular operation module is a modular mechanical arm mounted on the maintenance area, and the end effector thereof adopts a quick-change interface to support automatic switching of welding, spraying and other operation tools.

[0021] A pipeline maintenance method based on pressure balance regulation, comprising:

[0022] S1: Preparation before maintenance and installation of sealing pipe

[0023] Under the condition of non-stop transportation, the section of the pipeline that needs to be maintained is determined by external thermal imaging technology; first, the sealing pipe is welded on the outer wall of the pipeline at the predetermined position on the maintenance section to ensure the strength and absolute sealing of the connection; then, the opening operation is performed on the pipe wall by a special opening device, and this process is dynamically isolated from the medium in the pipeline through the integrated gate valve on the sealing pipe to ensure the safety of the opening operation and no medium leakage;

[0024] S2: Pressure balance introduction and pre-sealing of the intelligent double-gas bag sealing assembly

[0025] After the opening is completed, the positive and negative warehouses are installed on the gate valve in butt joint, first ensure that the gate valve is in the closed state, make the positive and negative warehouses become an independent transition chamber, through the external pressure adjusting system, vacuumize or pressurize the positive and negative warehouses, observe the pressure gauge until the internal pressure of the positive and negative warehouses is basically balanced with the medium pressure in the pipeline, slowly open the gate valve, because the internal and external pressure difference is very small, the medium in the pipeline will not be violently sprayed out, start the positioning driving part, smoothly push the plugging device support and the air bag assembly through the gate valve, and axially feed in the pipeline, accurately move to the predetermined plugging position; after reaching the specified position, start the pre-plugging program, first inflate the first annular sealing air bag, make it expand and form an interference fit with the inner wall of the pipeline, and establish a preliminary mechanical seal; at the same time, the pressure balance control system starts to work, the system senses the fluctuation of the medium pressure in the pipeline in real time through the pressure regulating hole, and based on the PID closed loop control algorithm, dynamically adjusts the internal pressure of the second pressure regulating air bag, when the pipeline pressure rises, the system immediately increases the internal pressure of the second pressure regulating air bag, and through the mechanical correlation, enhances the pressing force of the first annular sealing air bag on the pipe wall; when the pipeline pressure drops, it is slightly depressurized, the target is to make the sealing pressure always dynamically and adaptively slightly higher than the medium pressure;

[0026] S3: Liquid nitrogen freezing main plugging

[0027] At the same time, install the liquid nitrogen freezing plugging assembly, and build the main plugging through the liquid nitrogen freezing plugging assembly. The hydraulic cylinder drives the modular side ring seat of the frozen clamp to rotate around the hinge, so that the lower ring base and the side ring seat close and cover the outer wall of the pipeline. The V-shaped sealing elastic strip of the butt joint surface is extruded and sealed, and the nitrogen inlet is fastened to enhance the sealing performance. Then the liquid nitrogen tank delivers liquid nitrogen to the frozen clamp through the nitrogen delivery pipeline. The holographic control module controls the liquid nitrogen flow according to the feedback data of the distributed temperature sensor array to realize gradient cooling of "precooling-phase change-cryogenic", and gradually forms a dense pressure-bearing ice plug on the inner wall of the pipeline to form the first stage main plugging.

[0028] S4: Multiple barrier safety verification and automatic maintenance operation

[0029] The holographic control module comprehensively provides all the data provided by the multi-modal monitoring system to verify the safety and sealing reliability of the "multiple isolation barriers" composed of the intelligent double air bag and the liquid nitrogen ice plug. After verification, the modular mechanical arm enters the maintenance area, automatically switches tools through the end fast switching interface, completes the repair operation in the safety space under the protection of double plugging, and the operator can remotely monitor through the gesture-voice dual-mode interaction interface.

[0030] S5: Controllable unsealing and system recovery

[0031] After the maintenance is completed, start the unsealing and recovery system.

[0032] a. Ice plug thawing: A combined heating-natural thawing method is adopted to slowly and evenly melt the ice plug under the monitoring of the monitoring system;

[0033] b. Air bag pressure relief: A stepwise pressure relief program is executed to first reduce the pressure in the second pressure regulating air bag and then release the pressure of the first annular sealing air bag;

[0034] After confirming safety, the intelligent double air bag plugging assembly is withdrawn into the positive and negative warehouses, the gate valve is closed, the entire plugging assembly is finally removed from the pipeline, the opening point is repaired, and the entire repair is completed.

[0035] The beneficial effects of the present application are:

[0036] 1. The present application builds a multiple isolation barrier of "dynamic air bag buffer pressure stabilization and solid ice plug main pressure bearing" through the synergistic effect of liquid nitrogen freezing plugging and intelligent double air bag plugging, realizes safe and efficient repair operation without pipeline shutdown and medium emptying, and completely avoids the huge production interruption loss caused by traditional repair methods. The unique pressure balance regulation system enables the plugging structure to sense and adapt to the pressure fluctuation of the pipeline in real time, fundamentally solves the problem of sealing failure caused by pressure change, and ensures the plugging reliability under high pressure working conditions.

[0037] 2. The present application realizes intelligent decision and unified scheduling of the whole process based on multi-modal monitoring data through cooperation with the holographic control module, greatly improves the repair accuracy and efficiency, and at the same time maximizes the safety of personnel. In addition, the gradient cooling process and cold energy recovery design ensure the high strength and high energy efficiency of the ice plug, and the stepwise thawing program realizes the non-destructive recovery of the plugging structure. The high integration and strong adaptability of the entire device provide a revolutionary non-stop repair solution for pipeline maintenance in the fields of petroleum, chemical industry, etc., which has very high economic benefit and popularization value. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0039] Figure 1 It is a structure schematic view of a pipeline non-stop repair device based on pressure balance regulation of the present application;

[0040] Figure 2 It is another view of a structure schematic view of a pipeline non-stop repair device based on pressure balance regulation of the present application;

[0041] Figure 3 Structure diagram of the liquid nitrogen freezing plugging assembly of the present application;

[0042] Figure 4 Structure diagram of the ice freezing clamp of the present application;

[0043] Figure 5 Structure diagram of the ice freezing clamp of the present application after opening;

[0044] Figure 6 Connection diagram between the lower ring base and the two side ring bases of the present application;

[0045] Figure 7 Connection diagram of adjacent side ring bases of the present application;

[0046] Figure 8 Structure diagram of the intelligent double air bag plugging assembly of the present application;

[0047] Figure 9 Structure diagram of the modular mechanical arm of the present application.

[0048] The figure marks are:

[0049] 1. Liquid nitrogen freezing plugging assembly; 101. Ice freezing clamp; 1011. Lower ring base; 1012. Side ring base; 1013. Sealing elastic strip; 102. Liquid nitrogen tank; 1021. Nitrogen conveying pipeline; 1022. Liquid nitrogen recovery pipe; 103. Base; 104. Hydraulic cylinder; 105. Nitrogen inlet; 106. Clamping ring; 107. Clamping block;

[0050] 2. Intelligent double air bag plugging assembly; 201. Plugging device support; 202. First annular sealing air bag; 203. Second pressure regulating air bag; 204. Hollow part; 205. Pressure regulating hole; 206. Sealing pipe fitting; 207. Positive and negative warehouses; 208. Gate valve; 209. Positioning driving part; 210. Pressure gauge;

[0051] 3. Pipeline; 4. Modular mechanical arm. DETAILED DESCRIPTION

[0052] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the present application is further described below in combination with specific embodiments.

[0053] As shown in the accompanying Figure 1 to the accompanying Figure 9 The present application provides a pipeline non-stop conveying maintenance device based on pressure balance regulation, which comprises a plugging system, a multi-modal monitoring system, a holographic control module and a modular operation module.

[0054] The plugging system comprises a liquid nitrogen freezing plugging assembly 1 and a smart double air bag plugging assembly 2 arranged axially in sequence along both ends of the pipe 3 repair section, for building a multiple isolation barrier acting in sequence; specifically, the building logic and workflow of the multiple isolation barrier are as follows: first, the smart double air bag plugging assembly 2 located at the outermost side is activated as a pilot barrier, and its core function is not to immediately bear the entire medium pressure, but to actively adapt to and preliminarily stabilize the pipe 3 pressure environment through its unique pressure balance mechanism, to create a relatively stable “pressure buffer interval” for the formation of the inner liquid nitrogen ice plug. Subsequently, the liquid nitrogen freezing plugging assembly 1 is started to form a high-strength pressure-bearing ice plug in the pipe section that has been preliminarily stabilized, and this ice plug serves as the core pressure-bearing and sealing body. Finally, the smart double air bag provides dynamic redundant sealing to compensate for the sealing pressure decay that may be caused by temperature fluctuations or microscopic changes in the ice plug in real time. This sequential and cooperative logic of “first air bag buffer and pressure stabilization, then ice plug main plugging, and finally air bag dynamic protection” is the core of the device to achieve ultra-high reliability plugging under high pressure conditions.

[0055] The liquid nitrogen freezing plugging assembly 1 comprises a freezing clamp 101 for covering the outer wall of the pipe 3 and a liquid nitrogen tank 102 in communication with the freezing clamp 101, for forming and monitoring a pressure-bearing ice plug on the inner wall of the pipe 3 through a gradient cooling process, to constitute a first-stage main plugging; specifically, the specific implementation and physical principle of the gradient cooling process are as follows: the holographic control module pre-stores or generates an optimized cooling curve in real time, which is not a linear cooling but divided into three stages of “pre-cooling, phase change and deep cooling”. In the pre-cooling stage, the control system injects liquid nitrogen into the freezing clamp 101 at a small flow rate, aiming to uniformly reduce the wall temperature of the pipe 3 to the vicinity of the freezing point at a certain rate, which aims to avoid thermal shock stress. When the distributed temperature sensor detects that the wall temperature of the pipe 3 approaches the freezing point, the system enters the phase change stage, at which time the liquid nitrogen flow rate is increased to form a “liquid nitrogen bath” environment, which uses the heat absorption of liquid nitrogen vaporization to quickly remove the huge latent heat released during the phase change of the medium, and the main goal of the control system in this stage is to maintain the temperature near the freezing point with small fluctuations to ensure the uniform and dense growth of the ice plug from the pipe wall to the center, avoiding the formation of pores or cracks in the ice plug due to rapid cooling. When the sensor feedback indicates that the ice plug has been completely formed, the system enters the deep cooling stage, and the liquid nitrogen supply is adjusted again to supercool the core temperature of the ice plug to a design value (such as -10°C to -20°C) at a controllable rate. According to the strength-temperature characteristic curve of ice, this process can significantly improve the mechanical strength and pressure-bearing capacity of the ice plug. Throughout the process, the spatial temperature field data provided by the distributed temperature sensor array is the fundamental basis for the holographic control module to judge the cooling stage and adjust the control strategy.

[0056] The intelligent double-balloon plugging assembly 2 comprises a plugging support 201 positionable inside the pipeline 3, and a first annular sealing balloon 202 and a second pressure regulating balloon 203 arranged based on the plugging support 201. The first annular sealing balloon 202 is arranged around the peripheral wall of the plugging support 201 and is used to form an interference fit with the inner wall of the pipeline 3 after inflation. The second pressure regulating balloon 203 is arranged in the hollow portion 204 of the plugging support 201 and is in communication with the inner cavity of the pipeline 3 through the pressure regulating hole 205 penetrating the end surface of the plugging support 201. The second pressure regulating balloon 203 is in communication with the pressure balance regulating system and constitutes a second-stage dynamic plugging. Specifically, the cooperative working mechanism and the dynamic sealing principle of the intelligent double-balloon are as follows: the first annular sealing balloon 202 serves as a main sealing body and provides stable basic sealing force after inflation. The second pressure regulating balloon 203 is the pressure response core of the system and is not in direct contact with the inner wall of the pipeline 3 but is in communication with the pressure field of the medium in the pipeline 3 through the pressure regulating hole 205. When the pressure (P_pipe) in the pipeline 3 rises, the pressure is sensed immediately through the pressure regulating hole 205, and the pressure balance regulating system immediately inflates the second pressure regulating balloon 203 according to a preset algorithm (such as PID) to increase the internal pressure (P_bag) thereof. Since the second pressure regulating balloon 203 and the first annular sealing balloon 202 are mechanically related to each other, the increase of P_bag will equivalently enhance the pressing force of the first annular sealing balloon 202 on the pipe wall. The system control target is to always maintain the pressing force f(P_bag)≥P_pipe+ΔP (ΔP is a safety margin). Conversely, when P_pipe decreases, the system controls the second pressure regulating balloon 203 to slightly release pressure to prevent over-pressing damage or hindered unsealing of the balloon. This design realizes the "real-time, active and self-adaptive" tracking of the sealing force to the medium pressure, upgrades the traditional static sealing to dynamic sealing and fundamentally solves the plugging failure problem caused by pressure fluctuation.

[0057] As shown in the drawings, Figures 3-7 In one embodiment of the present application, the freezing clamp 101 is a claspable ring structure composed of a lower ring base 1011 and a plurality of modular side ring bases 1012. The lower ring base 1011 is symmetrically connected with the side ring bases 1012 through hinges on both sides, and the adjacent side ring bases 1012 are also connected through hinges. The abutting end faces of the lower ring base 1011, the side ring bases 1012 and the adjacent side ring bases 1012 are each provided with a V-shaped sealing elastic strip 1013. When the hydraulic cylinder 104 drives the clamp to close, each component rotates around the hinge shaft and is finally pressed tightly at the abutting end faces. This pressing force directly acts on the top of the V-shaped sealing elastic strip, causing elastic deformation of the unique V-shaped structure of the V-shaped sealing elastic strip and fully expanding to both sides, i.e. towards the two abutting metal end faces, thereby tightly filling and blocking all micro gaps and manufacturing tolerances between the abutting end faces of the components, effectively preventing the leakage of the injected liquid nitrogen and the low-temperature gas after the gasification of the liquid nitrogen from any abutting gap, and ensuring the formation of a sealed cavity.

[0058] Further, the liquid nitrogen freezing plugging assembly 1 further comprises a base 103 supporting the frozen clamp 101, and a hydraulic cylinder 104 driving the frozen clamp 101 to open and close. When the hydraulic cylinder 104 drives the frozen clamp 101 to close, the middle part of the two side ring bases 1012 in abutment forms a nitrogen inlet 105, and the outside of the nitrogen inlet 105 is sleeved with a clamping ring 106. The clamping ring 106 further enhances the sealing performance of the abutment part of the side ring base 1012, prevents the liquid nitrogen from leaking from the abutment gap during high-pressure conveying, and strengthens the connection stability of the nitrogen inlet 105 and the nitrogen conveying pipeline 1021. The lower ring base 1011 and the side part of the plurality of modular side ring bases 1012 in contact with the circumferential wall of the pipeline 3 are provided with clamping blocks 107, which are in contact with the circumferential wall of the pipeline 3 to form axial limiting, prevent the frozen clamp 101 from being axially displaced under the vibration of the pipeline 3 or the impact of the liquid nitrogen, and ensure the accurate positioning of the ice plug forming area.

[0059] In an embodiment of the present application, the liquid nitrogen tank 102 is in communication with the nitrogen inlets 105 of the two frozen clamps 101 through the nitrogen conveying pipeline 1021, and is connected with the outlet at the bottom of the frozen clamp 101 through the liquid nitrogen recovery pipeline 1022 to form a cold energy recovery loop. Specifically, the liquid nitrogen is injected into the cavity of the frozen clamp 101 from the top nitrogen inlet 105, and is vaporized into low-temperature nitrogen gas after absorbing the heat of the pipeline 3. If these low-temperature nitrogen gas accumulates in the cavity, it will form a heat insulation layer, which will hinder the heat exchange between the subsequent liquid nitrogen and the wall of the pipeline 3. These low-temperature nitrogen gas is actively led out and recovered through the liquid nitrogen recovery pipeline 1022 at the bottom, thereby forcibly establishing the gas flow in the cavity, destroying the heat insulation gas film, and significantly improving the heat exchange efficiency.

[0060] As shown in the drawings, Figure 8 In an embodiment of the present application, the intelligent double air bag plugging assembly 2 is introduced into the pipeline 3 through a sealing pipe 206, and the sealing pipe 206 is integrated with positive and negative chambers 207 and a gate valve 208, which are used to realize the dynamic isolation and balance of the pressure inside and outside the pipeline 3 during the insertion and extraction of the plugging assembly. The positive and negative chambers 207 are provided with a positioning driving element 209, which is in transmission connection with the plugging support 201, and is used to drive the intelligent double air bag plugging assembly 2 to axially feed in the pipeline 3, so as to realize the accurate control of the plugging position. A pressure gauge 210 is arranged on the pressure pipeline connected with the positive and negative chambers 207. Specifically, during the insertion process, the gate valve 208 is first closed to isolate the positive and negative chambers 207 from the outside, and the positive and negative chambers 207 are vacuumized or pressurized by an external pump set (not shown in the drawings) until the pressure gauge 210 shows that the internal pressure is basically balanced with the pressure in the pipeline 3. At this time, the gate valve 208 is opened, and since the pressure difference between the inside and outside is very small, the medium in the pipeline 3 will not be violently sprayed out. Then, the positioning driving element 209 (such as a hydraulic cylinder) located in the positive and negative chambers 207 pushes the plugging support 201 and the air bag assembly into the pipeline 3 until the specified position.

[0061] In an embodiment of the present application, the pressure balance regulation system (not shown in the figure) comprises a controller and a high-pressure gas source. The controller is connected to the second pressure regulating air bag 203 through an air path, and senses the change of the medium pressure in the pipeline 3 in real time through the pressure regulating hole 205, and dynamically adjusts the internal pressure of the second pressure regulating air bag 203 based on the PID closed-loop control algorithm, so that the air bag sealing pressure always adaptively tracks and is slightly higher than the medium pressure in the pipeline 3, realizing dynamic pressure balance and sealing enhancement. Specifically, the core logic of the pressure balance regulation system is the closed-loop control of "real-time sensing-accurate calculation-dynamic adjustment", which maintains the pressure balance of the plugging structure. The controller, as the core processing unit, collects the medium pressure signal in the pipeline 3 through the pressure sensing element at the pressure regulating hole 205. After filtering, the signal is transmitted to the control algorithm module. The core function of the PID closed-loop control algorithm is to automatically calculate the required inflation or pressure relief according to the difference between the pressure of the pipeline 3 and the internal pressure of the second pressure regulating air bag 203. The proportional element quickly responds to the pressure deviation, the integral element eliminates the steady-state error, and the differential element predicts the pressure change trend, which ensures the rapidity and stability of pressure regulation. The high-pressure gas source provides the power source for the pressure regulation of the second pressure regulating air bag 203. Its output pressure must have enough adjustment range to adapt to the pressure working conditions of different pipelines 3. When the medium pressure in the pipeline 3 rises, the controller instructs the high-pressure gas source to inflate the second pressure regulating air bag 203, so that the internal pressure of the air bag rises synchronously and is slightly higher than the pressure of the pipeline 3, and the sealing pressure of the air bag on the inner wall of the pipeline 3 is enhanced through the elastic expansion of the air bag; when the pressure in the pipeline 3 decreases, the controller instructs the air bag to release pressure, so as to avoid damage to the inner wall of the pipeline 3 or excessive stretching of the air bag caused by excessive internal pressure of the air bag, and always maintain the dynamic balance between the sealing pressure of the air bag and the pressure of the pipeline 3. This dynamic adjustment mechanism enables the plugging structure to adapt to various fluctuations of the pressure in the pipeline 3, avoids sealing failure caused by pressure imbalance, and ensures the safety and reliability of the non-stop transportation maintenance process.

[0062] In an embodiment of the present application, the multi-modal monitoring system (not shown in the figure) is integrated with a distributed temperature sensor array located in the freeze clamp 101, a pipe pressure sensor arranged on the wall of the pipe 3 for monitoring the medium pressure, a gas bag pressure sensor built in the gas circuit of the first annular sealing gas bag 202 and the second pressure regulating gas bag 203, and a vibration sensor arranged outside the freeze clamp 101 and the sealing pipe 206. The system is configured to monitor the sealing state in real time and feed back the monitoring data to the holographic control module for intelligent decision-making. Specifically, the multi-modal monitoring system realizes comprehensive perception and abnormal early warning of the sealing state through multi-dimensional and all-around sensing collection, and provides reliable data support for intelligent decision-making of the holographic control module. The distributed temperature sensor array is arranged in the freeze clamp 101, covering the key areas in the circumferential and axial directions of the pipe 3, which can capture the temperature distribution data of the pipe 3 wall in real time, not only can judge the progress of ice plug formation, but also can identify whether there is a local weak area in the ice plug through the temperature gradient change, avoiding the sealing failure caused by uneven ice plug strength. The pipe 3 pressure sensor directly monitors the dynamic change of the medium pressure in the pipe 3, provides the original pressure signal for the pressure balance control system, and simultaneously feeds back whether the working condition of the pipe 3 is stable in real time; the gas bag pressure sensor monitors the internal pressure of the first annular sealing gas bag 202 and the second pressure regulating gas bag 203 respectively, which can judge whether the gas bag is in normal sealing state, and if the pressure abnormally decreases, it can timely alarm the gas bag leakage problem. The vibration sensor is arranged outside the freeze clamp 101 and the sealing pipe 206, and its core function is to capture the vibration signal in the running process of the equipment, and through the change of vibration frequency and amplitude, to identify whether there is displacement in the sealing assembly, whether the gas bag abnormally rubs with the inner wall of the pipe 3, or whether there is structural vibration in the pipe 3, etc. The multi-modal monitoring system is not simply superimposed with various sensor data, but through data fusion technology, it comprehensively analyzes the monitoring data in different dimensions, removes the environmental interference signal, extracts the effective feature information, and ensures that the data fed back to the holographic control module can truly reflect the running state of the sealing system, providing accurate basis for subsequent control and adjustment and fault handling.

[0063] In an embodiment of the present application, the holographic control module is integrated with a gesture-voice dual-mode interactive interface (not shown in the figure), and is connected with the liquid nitrogen freezing plugging assembly 1, the intelligent double air bag plugging assembly 2, the pressure balance regulation system and the multi-modal monitoring system as a central processing unit. The holographic control module outputs cooperative control instructions based on the fusion data of the multi-modal monitoring system, and uniformly schedules the whole process of plugging establishment, dynamic pressure regulation, maintenance operation and unblocking recovery. Specifically, the holographic control module as the “central brain” of the whole device realizes the cooperative control of multiple systems and the intelligent scheduling of the whole process. The signal connection with each system component adopts a high-speed data transmission protocol to ensure the rapid issuance of control instructions and the real-time feedback of monitoring data, and realizes the synchronous response of each system. The design of the gesture-voice dual-mode interactive interface is to adapt to the complex on-site operation environment. The operator does not need to approach the control terminal, and can issue control commands such as starting plugging, adjusting cooling rate, switching maintenance tools, etc. through preset gestures or voice instructions, which not only improves the operation convenience, but also ensures the safety of the operator. Based on the fusion data of the multi-modal monitoring system, the intelligent decision algorithm built in the holographic control module can comprehensively judge the current working condition. When the monitoring data shows that the ice plug strength is insufficient, the holographic control module will automatically instruct the liquid nitrogen freezing plugging assembly 1 to increase the liquid nitrogen supply and prolong the cooling time. When the pressure fluctuation of the pipeline 3 is detected, the holographic control module will simultaneously schedule the pressure balance regulation system to adjust the pressure in the second pressure regulating air bag 203. After the maintenance operation is completed, the holographic control module will start the unblocking recovery process according to the preset program, coordinate the defrosting operation of the liquid nitrogen freezing plugging assembly 1 and the pressure relief operation of the intelligent double air bag plugging assembly 2, and ensure the orderly connection of the whole process. In addition, the holographic control module also has fault diagnosis and emergency treatment functions. When an abnormality occurs in a system, the holographic control module can quickly locate the fault cause and automatically start emergency measures such as cutting off the liquid nitrogen supply and emergency pressure relief, thereby minimizing the risk of failure and ensuring the safe operation of the maintenance operation.

[0064] As shown in Figure 4 In an embodiment of the present application, the modular operation module is a modular mechanical arm 4 mounted in the maintenance area. The end effector of the modular mechanical arm 4 adopts a quick-change interface to support automatic switching of welding, spraying and other operation tools. Specifically, the working process of the modular mechanical arm 4 is integrated in the unified scheduling of the holographic control module. When the multiple isolation barriers are confirmed to be established and the environmental parameters of the maintenance area are safe, the holographic control module instructs the mechanical arm to start operation. The quick-change interface usually adopts a pneumatic-electricity linkage quick insertion form, allowing the mechanical arm to automatically grab the required tool (such as a welding gun) from the tool library. After completing the operation (such as welding repair), the tool is put back and switched to the next tool (such as a spraying gun for corrosion protection). The whole process does not require manual entry into the pipeline 3 maintenance area, realizing complete mechanization and automation of maintenance operation in a closed and pressurized environment, ensuring personnel safety and improving operation accuracy and efficiency.

[0065] Wherein, in one embodiment of the application, the device further comprises a thawing recovery system (not shown in the figure) that melts the pressure ice plug by using a heating-natural thawing composite method, and cooperates with the stepped pressure relief program of the intelligent double air bag plugging assembly 2 to realize the lossless unsealing and system recovery of the pipeline 3 plugging structure. Specifically, first, the ice plug area is slowly warmed by the external heating unit to break the structural stability of the ice plug, accelerate the melting of the ice plug, and cooperate with the natural thawing process to make the ice plug melt gradually from the inside to the outside, avoiding the generation of thermal stress on the inner wall of the pipeline 3 due to local rapid heating, or the medium impact caused by rapid melting of the ice plug. The heating power of the heating unit needs to be gradually increased to ensure that the temperature gradient of the pipeline 3 is gentle, and to form a synergy with the natural thawing process, so that the ice plug melting rate is uniform and controllable. The stepped pressure relief program of the intelligent double air bag plugging assembly 2 follows the "dynamic first, static later" pressure relief logic, first slowly relieves the second pressure regulating air bag 203 to gradually reduce its internal pressure to be consistent with the medium pressure of the pipeline 3, eliminating the pressure constraint of dynamic plugging, and then relieves the first annular sealing air bag 202 to gradually shrink from the interference fit state, avoiding the sudden increase of the medium flow rate in the pipeline 3 due to rapid pressure relief, impacting the inner wall of the pipeline 3 or the completed repair part. During the entire unsealing process, the multi-modal monitoring system continuously monitors the ice plug melting progress, the pipeline 3 temperature change and the air bag pressure state, and feeds back the data to the holographic control module in real time. According to the monitoring data, the module dynamically adjusts the heating power and the pressure relief rate to ensure that the ice plug is completely melted and the air bag is safely shrunk, and then the plugging assembly is slowly pulled out of the pipeline 3 through the positioning drive 209, finally realizing the lossless unsealing and normal operation recovery of the pipeline 3.

[0066] A pipeline maintenance method without stopping transportation based on pressure balance regulation:

[0067] S1: Preparation before maintenance and installation of sealing pipe

[0068] Under the condition of non-stop transportation, the section of the pipeline 3 that needs to be repaired is determined by external thermal imaging technology. First, the sealing pipe 206 is welded on the outer wall of the pipeline 3 at the predetermined position on the maintenance section to ensure the strength and absolute sealing of the connection. Then, the hole opening equipment is used to open a hole on the wall of the pipeline 3, and this process is realized by the integrated gate valve 208 on the sealing pipe 206 to dynamically isolate the medium in the pipeline 3, ensuring the safety of the hole opening operation and no medium leakage.

[0069] S2: Pressure balance introduction and pre-plugging of intelligent double air bag plugging assembly

[0070] After the opening is completed, the positive and negative warehouses 207 are installed on the gate valve 208 in butt joint, first ensure that the gate valve 208 is in the closed state, and make the positive and negative warehouses 207 become an independent transition chamber. Through the external pressure regulating system, the positive and negative warehouses 207 are vacuumized or pressurized, and the pressure gauge 210 is observed until the internal pressure of the positive and negative warehouses 207 is basically balanced with the medium pressure in the pipeline 3. Slowly open the gate valve 208, because the internal and external pressure difference is very small, the medium in the pipeline 3 will not be violently sprayed out. Start the positioning drive 209, smoothly push the plugging device support 201 and the air bag assembly through the gate valve 208, and axially feed in the pipeline 3, accurately move to the predetermined plugging position. After reaching the specified position, the pre-plugging program is started: first, inflate the first annular sealing air bag 202, so that it expands and forms an interference fit with the inner wall of the pipeline 3, and establishes a preliminary mechanical seal. At the same time, the pressure balance regulating system starts to work. The system senses the fluctuation of the medium pressure in the pipeline 3 in real time through the pressure regulating hole 205, and dynamically adjusts the internal pressure of the second pressure regulating air bag 203 based on the PID closed-loop control algorithm. When the pressure in the pipeline 3 rises, the system immediately increases the internal pressure of the second pressure regulating air bag 203, and strengthens the pressing force of the first annular sealing air bag 202 on the pipe wall through mechanical correlation; when the pressure in the pipeline 3 drops, it is slightly depressurized. The goal is to make the sealing pressure always dynamically and adaptively slightly higher than the medium pressure;

[0071] S3: Liquid nitrogen freezing main plugging

[0072] At the same time, install the liquid nitrogen freezing plugging assembly 1, and build the main plugging through the liquid nitrogen freezing plugging assembly 1. The hydraulic cylinder 104 drives the modular side ring seat 1012 of the frozen clamp 101 to rotate around the hinge, so that the lower ring base 1011 and the side ring seat 1012 close and cover the outer wall of the pipeline 3. The V-shaped sealing elastic strip 1013 at the butt joint surface is extruded and sealed, and the clamping ring 106 is tightened into the nitrogen inlet 105 to enhance the sealing performance; then the liquid nitrogen tank 102 sends liquid nitrogen to the frozen clamp 101 through the nitrogen conveying pipeline 1021. The holographic control module controls the liquid nitrogen flow according to the feedback data of the distributed temperature sensor array to realize gradient cooling of "precooling-phase change-cryogenic", and gradually forms a dense pressure-bearing ice plug on the inner wall of the pipeline 3, forming the first stage main plugging;

[0073] S4: Multiple barrier safety verification and automatic maintenance operation

[0074] The holographic control module comprehensively provides all the data provided by the multi-modal monitoring system to verify the safety and sealing reliability of the "multiple isolation barriers" composed of the intelligent double air bag and the liquid nitrogen ice plug. After the verification is passed, the modular mechanical arm 4 enters the maintenance area, automatically switches the tool through the end fast-changing interface, and completes the repair operation in the safety space under the double plugging protection. And the operator can remotely monitor through the gesture-voice dual-mode interaction interface;

[0075] S5: Controllable unsealing and system recovery

[0076] After the maintenance is completed, start the unsealing and system recovery;

[0077] a. Ice plug thawing: A heating-natural thawing composite method is adopted to slowly and evenly melt the ice plug under the monitoring of the monitoring system;

[0078] b. Air bag pressure relief: A stepwise pressure relief program is executed to first reduce the pressure in the second pressure regulating air bag 203, and then release the pressure of the first annular sealing air bag 202;

[0079] After confirming the safety, the intelligent double air bag plugging assembly 2 is withdrawn into the positive and negative warehouses 207, the gate valve 208 is closed, and finally the whole plugging assembly is removed from the pipeline 3. The opening point is repaired, and the whole maintenance is completed.

[0080] The above only describes some exemplary embodiments of the present application by way of illustration, and it is needless to say that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above drawings and descriptions are illustrative in nature and should not be understood as limiting the scope of protection of the claims of the present application.

Claims

1. A pipeline maintenance device based on pressure balance regulation, comprising a plugging system, a multi-modal monitoring system, a holographic control module and a modular operation module, characterized in that: the plugging system comprises a liquid nitrogen freezing plugging assembly (1) and an intelligent double air bag plugging assembly (2) arranged axially along the two ends of the pipeline (3) maintenance section, for building a multi-isolation barrier that acts sequentially; wherein the liquid nitrogen freezing plugging assembly (1) comprises a frozen clamp (101) for covering the outer wall of the pipeline (3) and a liquid nitrogen tank (102) in communication with the frozen clamp (101), for forming and monitoring a pressure-bearing ice plug on the inner wall of the pipeline (3) by gradient cooling process, constituting the first stage main plugging; the intelligent double air bag plugging assembly (2) comprises a plugging device support (201) which can be positioned inside the pipeline (3), and a first annular sealing air bag (202) and a second pressure regulating air bag (203) based on the support, the first annular sealing air bag (202) is arranged around the peripheral wall of the plugging device support (201), for forming an interference fit with the inner wall of the pipeline (3) after inflation, the second pressure regulating air bag (203) is arranged in the hollow part (204) of the plugging device support (201), and is in communication with the inner cavity of the pipeline (3) through the pressure regulating hole (205) penetrating the end surface of the plugging device support (201), the second pressure regulating air bag (203) is in communication with the pressure balance regulation system, constituting the second stage dynamic plugging. The frozen clamp (101) is a openable and closable ring structure composed of a lower ring base (1011) and a plurality of modular side ring bases (1012), the lower ring base (1011) is symmetrically connected with the side ring bases (1012) on both sides through hinges, and adjacent side ring bases (1012) are also connected through hinges, and the abutting end faces of the lower ring base (1011), the side ring base (1012) and the adjacent side ring base (1012) are all provided with V-shaped sealing elastic strips (1013). The liquid nitrogen freezing plugging assembly (1) further comprises a base (103) supporting the frozen clamp (101) and a hydraulic cylinder (104) driving the frozen clamp (101) to open and close, when the hydraulic cylinder (104) drives the frozen clamp (101) to close, the middle part of the two side ring bases (1012) in abutment forms a nitrogen inlet (105), the outside of the nitrogen inlet (105) is sleeved with a clamping ring (106), and the side part of the lower ring base (1011) and the plurality of modular side ring bases (1012) in contact with the peripheral wall of the pipeline (3) is provided with a clamping block (107). The liquid nitrogen tank (102) is in communication with the nitrogen inlets (105) of the two frozen clamps (101) through a nitrogen conveying pipeline (1021), and is connected with the outlet at the bottom of the frozen clamp (101) through a liquid nitrogen recovery pipeline (1022) to form a cold energy recovery circuit.

2. The device for pipeline maintenance without shutdown based on pressure balance regulation according to claim 1, characterized in that: ​ 3. The device for pipeline maintenance without stopping transportation based on pressure balance regulation according to claim 2, characterized in that: ​ 4. The device for pipeline maintenance without stopping transportation based on pressure balance regulation according to claim 3, characterized in that: ​ 5. The device for pipeline maintenance without shutdown based on pressure balance regulation according to claim 1, characterized in that: The intelligent double air bag sealing assembly (2) is introduced into the pipeline (3) through a sealing pipe (206), the sealing pipe (206) is integrated with positive and negative warehouses (207) and a gate valve (208), and is used for realizing dynamic isolation and balance of pressure inside and outside the pipeline during insertion and extraction of the sealing assembly; the positive and negative warehouses (207) are provided with a positioning driving element (209), the positioning driving element (209) is in transmission connection with the occluder support (201), and is used for driving the intelligent double air bag sealing assembly (2) to axially feed in the pipeline (3), so as to realize accurate control of a sealing position of the intelligent double air bag sealing assembly (2); and a pressure gauge (210) is arranged on a pressure pipeline connected with the positive and negative warehouses (207).

6. The device for pipeline maintenance without shutdown based on pressure balance regulation according to claim 1, characterized in that: The pressure balance regulation system comprises a controller and a high-pressure gas source, the controller is connected with the second pressure regulating air bag (203) through a gas circuit, changes of medium pressure in the pipeline (3) are sensed in real time through the pressure regulating hole (205), and the internal pressure of the second pressure regulating air bag (203) is dynamically adjusted based on a PID closed-loop control algorithm, so that the sealing pressure of the air bag is always adaptively tracked and slightly higher than the medium pressure in the pipeline (3), and dynamic pressure balance and sealing enhancement are realized.

7. The device for pipeline maintenance without shutdown based on pressure balance regulation according to claim 1, characterized in that: The multi-modal monitoring system is integrated with a distributed temperature sensor array located in the freezing clamp (101), a pipeline pressure sensor arranged on a wall of the pipeline (3) and used for monitoring medium pressure, an air bag pressure sensor built in a gas circuit of the first annular sealing air bag (202) and the second pressure regulating air bag (203), and a vibration sensor arranged outside the freezing clamp (101) and the sealing pipe (206), the system is configured to monitor a sealing state in real time and feed monitoring data to the holographic control module, so that the holographic control module makes intelligent decisions.

8. The device for hot-tap repair of a pipeline based on pressure balance regulation according to claim 1, characterized in that it further comprises: The holographic control module is integrated with a gesture-voice dual-mode interaction interface, and is connected with the liquid nitrogen freezing sealing assembly (1), the intelligent double air bag sealing assembly (2), the pressure balance regulation system and the multi-modal monitoring system as a central processing unit, the holographic control module outputs a cooperative control instruction based on fusion data of the multi-modal monitoring system, and uniformly schedules a whole process of sealing establishment, dynamic pressure regulation, maintenance operation and unsealing recovery.

9. The device for hot-tap repair of a pipeline based on pressure balance regulation according to claim 1, characterized in that it further comprises: The modular operation module is a modular mechanical arm (4) carried on a maintenance area, and an end effector of the modular mechanical arm (4) adopts a quick-change interface and supports automatic switching of operation tools such as welding and spraying.

10. A method for pressure balance regulation based on-line maintenance of pipelines, used for realizing the pressure balance regulation based on-line maintenance device of any one of claims 1-9, characterized in that, Comprising: S1: Preparation before maintenance and installation of a sealing pipe Under the condition that the pipeline (3) is not stopped, a section needing to be maintained on the pipeline (3) is determined through external thermal imaging technology; first, the sealing pipe 206 is welded on the outer wall of the pipeline (3) at a predetermined position on the maintenance section, so as to ensure the strength and absolute sealing of the connection; then, a dedicated hole opening device is used to perform hole opening operation on the wall of the pipeline (3), and the hole opening operation is dynamically isolated from the medium in the pipeline (3) through the gate valve (208) integrated on the sealing pipe (206), so as to ensure the safety of the hole opening operation and prevent medium leakage; S2: Pressure balance introduction and pre-sealing of the intelligent double air bag sealing assembly After the opening is completed, the positive and negative chambers (207) are installed on the gate valve (208). First, ensure that the gate valve (208) is closed so that the positive and negative chambers (207) become an independent transition chamber. Vacuum or pressurize the positive and negative chambers (207) through the external pressure regulation system and observe the pressure gauge (210) until the internal pressure is basically balanced with the pressure of the medium in the pipeline (3). Slowly open the gate valve (208). Since the pressure difference between the inside and outside is very small, the medium in the pipeline (3) will not violently spray out. Start the positioning drive (209) and smoothly push the plugger bracket (201) and airbag assembly through the gate valve (208) to make axial feed in the pipeline (3) and move accurately to the predetermined plugging position. After reaching the designated position, The pre-sealing procedure is initiated by first inflating the first annular sealing airbag (202) to expand it and form an interference fit with the inner wall of the pipe (3), thus establishing a preliminary mechanical seal. At the same time, the pressure balance control system starts working. The system senses the fluctuation of the medium pressure in the pipe (3) in real time through the pressure regulating hole (205) and dynamically adjusts the internal pressure of the second pressure regulating airbag (203) based on the PID closed-loop control algorithm. When the pressure in the pipe (3) increases, the system immediately increases the internal pressure of the second pressure regulating airbag (203) and strengthens the clamping force of the first annular sealing airbag (202) on the pipe wall through mechanical correlation. When the pressure in the pipe (3) decreases, a small amount of pressure is released. The goal is to keep the sealing pressure dynamically and adaptively slightly higher than the medium pressure. S3: Liquid nitrogen cryogenic main sealing Meanwhile, a liquid nitrogen freezing and plugging assembly (1) is installed, and a main plug is constructed through the liquid nitrogen freezing and plugging assembly (1). The hydraulic cylinder (104) drives the modular side ring seat (1012) of the freezing clamp (101) to rotate around the hinge, so that the lower ring base (1011) and the side ring seat (1012) close and cover the outer wall of the pipe (3). The V-shaped sealing elastic strip (1013) of the mating end face is squeezed and sealed, and the clamping ring (106) tightens the nitrogen inlet (105) to enhance the sealing performance. Subsequently, the liquid nitrogen tank (102) delivers liquid nitrogen to the freezing clamp (101) through the nitrogen delivery pipe (1021). The holographic control module controls the liquid nitrogen flow rate to achieve "pre-cooling-phase change-deep cooling" gradient cooling based on the feedback data of the distributed temperature sensor array, and gradually forms a dense pressure-bearing ice plug on the inner wall of the pipe (3), constituting the first-stage main plug. S4: Multi-barrier safety verification and automated maintenance operations The holographic control module integrates all the data provided by the multimodal monitoring system to conduct the final safety and sealing reliability verification of the "multiple isolation barriers" composed of intelligent dual airbags and liquid nitrogen ice plugs. After the verification is passed, the modular robotic arm (4) enters the maintenance area and automatically switches tools through the quick-change interface at the end. The repair work is completed in the safe space under the double sealing protection. The operator can also remotely monitor through the gesture-voice dual-mode interactive interface. S5: Controlled Unsealing and System Recovery After the repair is completed, start the unblocking and recovery system; a. Ice plug thawing: The ice plug is thawed slowly and evenly under the monitoring of the monitoring system by using a heating-natural thawing combination method; b. Air bag pressure relief: A stepwise pressure relief program is executed to first reduce the pressure in the second pressure regulating air bag (203) and then release the pressure of the first annular sealing air bag (202); After confirming safety, the intelligent double air bag plugging assembly (2) is withdrawn into the positive and negative bin (207), the gate valve (208) is closed, the entire plugging assembly is finally removed from the pipeline (3), the opening point is repaired, and the entire repair is completed.

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