Non-excavation repair method for narrow cement pipeline

Abstract

The invention discloses a non-excavation repair method for a narrow cement pipeline, belongs to the technical field of pipeline repair, and aims to solve the problems of high construction difficulty, high cost and non-uniform filling of a repair material in the narrow cement pipeline in a traditional excavation repair method. According to the method, a base matched with the inner diameter of a pipeline is customized, two parallel annular air bags are arranged in the middle of the base and connected with an inflation pump, an elastic mortar storage device is arranged between the two air bags, and through holes are circumferentially distributed in the outer side of the base and communicate with the storage device through a connecting pipe; after the base injected with repairing mortar is placed in a pipeline, the air bag is expanded through the inflation pump to extrude the storage device, the mortar is forced to be filled into gaps of the inner wall of the pipeline through the through hole, meanwhile, the base is dragged to move at a constant speed through the pull rope and dragging equipment, and it is ensured that the mortar continuously covers a damaged area. According to the method, uniform repairing is achieved through cooperative control over the pressure of the air bag and the traction speed, the method is mainly used for non-excavation repairing of the narrow cement pipeline, the construction efficiency can be effectively improved, and the influence on the surrounding environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline repair. More specifically, the present invention relates to a trenchless repair method for narrow cement pipelines. Background Art

[0002] In the field of municipal engineering, traditional cement pipeline repair methods mainly rely on excavation construction. For the repair of narrow cement pipelines (usually with an inner diameter less than 300 mm), the excavation method requires large-scale damage to the road surface and surrounding facilities. It not only has a long construction period and high cost, but also easily causes problems such as traffic interruption and secondary damage to underground pipelines in urban dense areas. In addition, due to the limited internal space of narrow pipelines, it is difficult for conventional repair equipment to enter, resulting in a high proportion of manual operations and low construction efficiency. Among the existing trenchless technologies, although the lining method or the grouting repair method can avoid excavation, there are still significant deficiencies. For example, the lining method requires the installation of prefabricated materials in the pipeline, but the bending section or local deformation area of the narrow pipeline is likely to cause uneven lining fitting and form cavities; the grouting method relies on the fluidity of the slurry to fill the damaged area. However, the diffusion range of the slurry in the narrow pipeline is limited, and local accumulation or uncovered areas are likely to occur. After repair, the strength distribution of the pipe wall is uneven, and secondary cracking may occur due to stress concentration during long-term use. The root cause of the above problems is that it is difficult to meet the refined requirements for material transportation and pressure control in the repair of narrow pipelines. First, due to size limitations, traditional equipment cannot be adapted to pipelines with different inner diameters, resulting in difficulty in stably controlling the gap between the repair material injection device and the pipe wall. Second, the flow of the slurry or repair material relies on manual experience to adjust the pressure, lacking a real-time feedback mechanism, and it is easy to cause uneven material distribution due to pressure fluctuations. For example, when the pressure is insufficient, the material cannot fully fill the cracks, and when the pressure is too high, it may cause the material to overflow or the pipe wall to be deformed by pressure. In addition, the traction speed of the repair device in the narrow pipeline and the extrusion rate of the material need to be strictly matched. However, most of the existing technologies use a fixed speed for traction and cannot dynamically respond to changes in the pipeline inner diameter or local resistance differences, resulting in fluctuations in the thickness of the repair layer and affecting the structural integrity. When attempting to optimize the above problems, the technical implementation faces multiple difficulties. First, how to design a repair device with both flexibility and rigidity within a limited space, which can not only adapt to the irregular surface of the inner wall of the pipeline but also withstand the extrusion pressure of the repair material. Second, how to achieve real-time coordinated control of the flow rate of the repair material and the traction speed. Existing control systems mostly rely on single-parameter feedback (such as pressure or speed) and lack the support of a multi-parameter coupling model, making it difficult to maintain stable output under complex working conditions. For example, when the traction speed increases, if the material extrusion rate does not increase synchronously, the repair layer will be too thin; conversely, it may cause blockage due to material accumulation. Third, the environment inside the narrow pipeline is complex (such as water accumulation, sediment, etc.), and traditional sensors are easily interfered with, resulting in insufficient data acquisition accuracy, further affecting the reliability of the control system. These problems jointly restrict the engineering applicability and long-term durability of the trenchless repair technology for narrow cement pipelines. Summary of the Invention

[0003] One object of the present invention is to provide a trenchless repair method for narrow cement pipelines, which solves the problems of traditional narrow cement pipeline repair relying on excavation construction, such as high construction difficulty, high cost, and uneven distribution of repair materials.

[0004] To achieve these objects and other advantages of the present invention, according to one aspect of the present invention, there is provided a trenchless repair method for narrow cement pipelines, including the following steps: Step 1: Customize a base that matches the inner diameter size of the cement pipeline to be repaired. Two parallel annular airbags are arranged in the middle of the base. The annular airbags are all connected with an air inflation pump. An elastic mortar reservoir is connected and arranged between the two annular airbags inside the base. Through holes are arranged on the outer surface of the base along the circumferential direction. The elastic mortar reservoir is communicated with the through holes through a connecting pipe; Step 2: Inject repair mortar into the elastic mortar reservoir, place the base into the cement pipeline to be repaired, fixedly connect a pull rope at both ends of the base, and install guide pulleys at the entrance and exit of the cement pipeline to be repaired, so that the pull rope passes through the guide pulleys and is connected with an external dragging device; Step 3: Inject compressed air into the annular airbag through the air inflation pump to expand the annular airbag to closely fit the inner wall of the pipeline, and at the same time squeeze the elastic mortar reservoir, forcing the repair mortar to flow out of the through hole through the connecting pipe and fill the gap between the base and the inner wall of the pipeline; Step 4: Start the dragging device, uniformly traction the pull rope, drive the base to move along the inner wall of the pipeline. During this process, the annular airbag maintains the extrusion of the elastic mortar reservoir to ensure that the repair mortar continuously extrudes from the through hole and covers the damaged area inside the pipeline; Step 5: After the pipeline repair is completed, conduct a water storage inspection.

[0005] Preferably, in the fourth step, the dragging device is connected to the intelligent control system, and the intelligent control system includes a speed sensor, a flow meter, and a data processor; The speed sensor is installed on the traction mechanism of the dragging device for real-time collection of traction speed data; The flow meter is installed at the outlet of the connecting pipe of the elastic mortar reservoir for real-time monitoring of the outflow of the repair mortar; The data processor receives the signals from the speed sensor and the flow meter. When it detects that the traction speed deviates from the range of 0.1 - 0.3 m / s or the mortar outflow is lower than the preset threshold, it automatically generates a control instruction and sends it to the speed regulation module of the dragging device and the pressure regulating valve of the air pump; The speed regulation module adjusts the traction speed to the set range according to the control instruction; The pressure regulating valve increases the inflation pressure of the annular airbag according to the control instruction to enhance the extrusion strength of the elastic mortar reservoir, thereby increasing the mortar outflow.

[0006] Preferably, the dragging device is an electric winch, and its traction mechanism includes a servo motor, a reducer, and an electromagnetic brake; The output shaft of the servo motor is connected to the drum through a reducer, and the surface of the drum is provided with spiral grooves to adapt to the winding track of the pulling rope; The electromagnetic brake is integrated at the output end of the reducer for locking or releasing the rotation of the drum in real time when the speed regulation module issues an instruction; The control interface of the electric winch is connected to the data processor of the intelligent control system through the CAN bus, receives the digital control signal output by the speed regulation module, and feeds back the real-time traction speed data to the data processor.

[0007] Preferably, the data processor receives the traction speed signal output by the speed sensor and the mortar outflow signal output by the flow meter in real time; When the traction speed signal continuously exceeds the range of 0.1 - 0.3 m / s for 5 seconds, the data processor sends a first control instruction to the speed regulation module. The speed regulation module adjusts the output torque of the servo motor through the reducer to control the rotation of the drum and adjusts the traction speed to the reference value of 0.2 m / s; When the mortar outflow signal is lower than the preset threshold of 0.8 L / min, the data processor sends a second control instruction to the pressure regulating valve. The pressure regulating valve increases the inflation pressure of the annular airbag by adjusting the valve opening until the mortar outflow reaches 0.8 L / min.

[0008] Preferably, a pressure sensor is also installed inside the annular airbag for real-time monitoring of the airbag pressure inside the annular airbag. The data processor has a built-in pressure-flow compensation model. When the airbag pressure reaches the upper limit value of 0.18 MPa and the mortar outflow rate is still lower than the threshold value of 0.8 L / min, a pause instruction for the dragging device is automatically triggered, and an artificial intervention alarm signal is generated.

[0009] Preferably, the construction and execution of the pressure-flow compensation model include the following steps: (a) Establish a non-linear mapping relationship between the airbag pressure P and the repair mortar flow rate Q based on experimental calibration data, and its mathematical model is: ; In the formula, k is the mortar rheological characteristic coefficient, P0 is the initial flow-starting pressure threshold, and α is the dynamic correction factor of the traction speed v on the flow rate; (b) During the repair process, the data of the pressure sensor inside the annular airbag, the data of the flowmeter, and the traction speed data are collected in real time, and the model parameters k, P0, and α are updated online by the recursive least squares method to make the model adapt to the current pipeline working conditions; (c) When it is detected that the mortar outflow rate is lower than 0.8 L / min, calculate the target compensation pressure according to the current model, and generate a pressure adjustment instruction, where Q threshold is the preset minimum threshold value of the repair mortar flow rate of 0.8 L / min; (d) If P target ≤ 0.18 MPa, control the pressure regulating valve to increase the pressure precisely according to P target ; if P target > 0.18 MPa, trigger an artificial intervention alarm.

[0010] Preferably, the diameter of the through hole is 6 - 8 mm, and one through hole is arranged every 15° along the circumferential direction of the base.

[0011] Preferably, the air inflation pump is a dual-channel linkage air pump. The two air inflation channels are respectively connected to the two annular airbags, and the air inflation pump has a built-in pressure balance module. When the air pressure of a single annular airbag exceeds 0.15 MPa, the excess gas is automatically transferred to the other annular airbag.

[0012] Preferably, the outer arc surfaces of the two annular airbags are covered with a rubber anti-slip layer with a thickness of 2 - 3 mm.

[0013] The present invention has at least the following beneficial effects: First, the trenchless repair method for narrow cement pipelines in the present invention realizes precise positioning and continuous operation of trenchless repair through the design of a customized base matching the pipe diameter combined with an annular airbag squeezing an elastic mortar reservoir, supplemented by an electric winch traction system and a uniformly distributed through-hole structure, significantly reducing the interference of construction on the environment. At the same time, through the airbag expanding and fitting the pipe wall and the mortar evenly covering, the compactness and structural strength of the repair layer are ensured.

[0014] Second, the introduction of the intelligent control system combined with the pressure-flow compensation model dynamically adjusts parameters and adapts to different working conditions by real-time monitoring of the traction speed, mortar flow rate, and airbag pressure, avoiding both material waste and repair defects, and improving the automation level and repair consistency.

[0015] Third, through the optimization of details such as a dual-channel linkage air pump and a rubber anti-slip layer, the stability and safety of equipment operation are enhanced. Through pressure balance and anti-slip design, the repair process is ensured to be stable and controllable, while the service life of key components is extended. The overall solution takes into account technical feasibility, economy, and reliability, providing a systematic solution for the trenchless repair of narrow pipelines.

[0016] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the base described in the present invention; Figure 2 is a sectional view of the base described in the present invention; Among them, 100 is the base, 101 is the annular airbag, 102 is the elastic mortar reservoir, 103 is the through-hole, 104 is the connecting pipe, and 200 is the pulling rope. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following further detailed description of the present invention is made in conjunction with the drawings and specific embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0019] It should be understood that the terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0020] It should be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0021] As Figures 1 - 2 shown, the present invention provides a trenchless repair method for narrow cement pipelines, including the following steps: Step 1: Customize a base 100 that matches the inner diameter size of the cement pipe to be repaired. Two parallel annular airbags 101 are arranged in the middle of the base 100. The annular airbags 101 are each connected to an air inflation pump. An elastic mortar reservoir 102 is connected and arranged between the two annular airbags 101 inside the base 100. Through holes 103 distributed circumferentially are provided on the outer surface of the base 100. The elastic mortar reservoir 102 is communicated with the through holes 103 through a connecting pipe 104; Step 2: Inject repair mortar into the elastic mortar reservoir 102. Place the base 100 inside the cement pipe to be repaired. Fix and connect a pulling rope 200 at both ends of the base 100. Install guiding pulleys at the inlet and outlet of the cement pipe to be repaired, and make the pulling rope 200 pass through the guiding pulleys and then be connected to an external dragging device; Step 3: Inject compressed air into the annular airbags 101 through the air inflation pump, so that the annular airbags 101 expand to closely fit the inner wall of the pipe. At the same time, squeeze the elastic mortar reservoir 102 to force the repair mortar to flow out of the through holes 103 through the connecting pipe 104 and fill the gap between the base 100 and the inner wall of the pipe; Step 4: Start the dragging device and uniformly traction the pulling rope 200 to drive the base 100 to move along the inner wall of the pipe. During this process, the annular airbags 101 maintain the extrusion of the elastic mortar reservoir 102 to ensure that the repair mortar continuously extrudes from the through holes 103 and covers the damaged area inside the pipe; Step 5: After the pipe repair is completed, conduct a water storage inspection.

[0022] In this technical solution, the customized base 100 matches the inner diameter size of the cement pipeline to be repaired. The two parallel annular airbags 101 in the middle of the base 100 can be airbags made of nitrile rubber. The air pump can be a common electric air pump on the market, and its inflation pressure and flow rate can meet the airbag inflation requirements. The elastic mortar reservoir 102 can be a soft reservoir made of polyurethane material, with good elasticity and corrosion resistance. The diameter of the through holes 103 distributed circumferentially on the outer surface of the base 100 can be selected as 6mm, 7mm or 8mm, and one is arranged every 15° along the circumference of the base 100. During assembly, the annular airbag 101 is installed in the middle of the base 100 and connected to the air pump through the connecting pipe 104; the elastic mortar reservoir 102 is installed between the two annular airbags 101; the through holes 103 are evenly distributed on the outer surface of the base 100, one end of the connecting pipe 104 is communicated with the elastic mortar reservoir 102, and the other end is connected to the through hole 103. The repair mortar injected into the elastic mortar reservoir 102 can be a common high-strength cement-based repair mortar on the market, which has good adhesion and high strength. The pull rope 200 can be made of steel wire rope, which has high strength and good wear resistance. The dragging device can be an electric winch with moderate traction capacity. The guiding pulley can be a pulley made of cast iron, with a smooth surface, which can effectively reduce the wear of the pull rope 200. During installation, first inject the repair mortar into the elastic mortar reservoir 102, and then place the base 100 into the cement pipeline to be repaired. Fix the steel wire ropes at both ends of the base 100, install the guiding pulleys at the inlet and outlet of the pipeline, and connect the steel wire ropes to the electric winch after passing through the guiding pulleys. The working process is as follows: First, complete the installation and preparation of the above components. Inject compressed air into the annular airbag 101 through the air pump, and the airbag expands and closely adheres to the inner wall of the pipeline and squeezes the elastic mortar reservoir 102, so that the repair mortar flows out from the through hole 103 through the connecting pipe 104 and fills the gap between the base 100 and the inner wall of the pipeline. Start the electric winch and evenly pull the steel wire rope to drive the base 100 to move along the inner wall of the pipeline. During the movement, the airbag continuously squeezes the reservoir to ensure that the repair mortar continuously covers the damaged area in the pipeline. After the repair is completed, conduct a water storage inspection to observe whether there is any leakage in the pipeline. This method can realize the trenchless repair of narrow cement pipelines, reduce the impact of construction on the surrounding environment, improve the construction efficiency, ensure the compactness and structural strength of the repair layer, and enable the repaired pipeline to meet the normal use requirements. In the above technical solution, by customizing the base 100 that matches the inner diameter of the pipeline, it is ensured that the repair device can closely fit the narrow cement pipeline. The annular airbag 101 made of nitrile rubber has good flexibility and sealing performance. It can not only closely adhere to the inner wall of the pipeline, but also effectively transmit the pressure of the extrusion elastic mortar reservoir 102, so that the repair mortar is evenly extruded. The elastic mortar reservoir 102 made of polyurethane has good elasticity and corrosion resistance, ensuring the storage and smooth extrusion of the mortar. The through holes 103 with a diameter of 6 - 8 mm and arranged at an interval of 15° are conducive to the even distribution of the mortar on the inner wall of the pipeline, avoiding local accumulation or uncovered areas, improving the uniformity and integrity of the repair layer, and thus enhancing the overall structural strength of the pipeline. The high-strength cement-based repair mortar has strong adhesion and high strength, and can effectively fill the damaged part of the pipeline and restore the bearing capacity of the pipeline. The steel wire rope is used as the pulling rope 200, which has high strength and good wear resistance and is not easy to break during the traction process, ensuring the stable movement of the base 100 in the pipeline. The small electric winch is used as the dragging device, and its traction capacity is moderate, and it can accurately control the moving speed of the base to match the mortar extrusion speed. The surface of the guiding pulley made of cast iron is smooth, reducing the friction between the pulling rope 200 and the pulley, reducing the wear of the pulling rope 200, extending the service life of the pulling rope 200, and ensuring the smooth progress of the entire repair process. The entire repair process is reasonably designed. By inflating the airbag through an air pump to expand and extrude the mortar reservoir, and then combining with the uniform traction of the electric winch to move the base, the continuous and uniform coverage of the damaged area of the pipeline by the mortar is realized. The water storage inspection after the repair can timely detect the leakage problem after the pipeline repair, ensure the repair quality, enable the repaired pipeline to operate normally after being put into use, reduce the subsequent maintenance cost, and ensure the long-term stable use of the pipeline.

[0023] In another technical solution, in step four, the dragging device is connected to an intelligent control system, and the intelligent control system includes a speed sensor, a flow meter, and a data processor; The speed sensor is installed on the traction mechanism of the dragging device and is used to collect the traction speed data in real time; The flow meter is installed at the outlet of the connecting pipe 104 of the elastic mortar reservoir 102 and is used to monitor the outflow volume of the repair mortar in real time; The data processor receives the signals from the speed sensor and the flow meter. When it detects that the traction speed deviates from the range of 0.1 - 0.3 m / s or the mortar outflow volume is lower than the preset threshold, it automatically generates a control instruction and sends it to the speed regulation module of the dragging device and the pressure regulating valve of the air pump; The speed regulation module adjusts the traction speed to the set range according to the control instruction; The pressure regulating valve increases the inflation pressure of the annular airbag 101 according to the control instruction to enhance the extrusion strength on the elastic mortar reservoir 102, thereby increasing the mortar outflow volume.

[0024] In this technical solution, the speed sensor of the intelligent control system can select a magnetoelectric speed sensor, which has high measurement accuracy and can accurately and real-time collect the traction speed data of the traction mechanism of the dragging device. The flowmeter can select an electromagnetic flowmeter, which has high measurement accuracy and good stability and is suitable for installation at the outlet of the connecting pipe 104 of the elastic mortar reservoir 102 to accurately and real-time monitor the outflow of the repair mortar. The data processor can use an industrial-grade single-chip microcomputer, which has a fast operation speed and high reliability and can quickly receive the signals of the speed sensor and the flowmeter. The speed regulation module can select a variable frequency speed regulator adapted to the motor of the dragging device to accurately adjust the traction speed according to the instructions of the data processor. The pressure regulating valve can be installed on the connecting pipe 104, and an electric proportional regulating valve is selected. By receiving the control instruction, it can accurately regulate the inflation pressure of the annular airbag 101. The magnetoelectric speed sensor is installed on the traction mechanism of the dragging device, the electromagnetic flowmeter is installed at the outlet of the connecting pipe 104 of the elastic mortar reservoir 102, the industrial-grade single-chip microcomputer is used as the data processor to receive the sensor signals, the variable frequency speed regulator is connected to the motor of the dragging device, and the electric proportional regulating valve is installed on the connecting pipe 104 of the air inflation pump and the annular airbag 101. The selection basis of the above-mentioned intelligent control system-related equipment lies in the performance characteristics of each equipment. The magnetoelectric speed sensor measures speed using the principle of electromagnetic induction, has a wide measurement range and an accuracy that can reach ±0.05 m / s, meeting the requirements for the acquisition accuracy of the traction speed data. The electromagnetic flowmeter measures flow based on Faraday's law of electromagnetic induction, is not affected by factors such as fluid density and viscosity, and has a measurement accuracy of up to ±0.5%, enabling reliable monitoring of the mortar outflow. The industrial-grade single-chip microcomputer has rich interface resources and powerful computing capabilities, and can quickly process and analyze the signals of multiple sensors. The variable frequency speed regulator realizes speed regulation by changing the motor power supply frequency, has a wide speed regulation range and high accuracy, and can accurately adjust the traction speed to the set range. The electric proportional regulating valve can proportionally adjust the valve opening according to the control signal, thereby accurately controlling the airbag inflation pressure. During the working process, the speed sensor real-time collects the traction speed data, the flowmeter real-time monitors the mortar outflow data, and transmits the data to the data processor. When the traction speed deviates from the range of 0.1 - 0.3 m / s or the mortar outflow is lower than the preset threshold, the data processor automatically generates a control instruction. If the traction speed is abnormal, the control instruction is sent to the variable frequency speed regulator, and the speed regulator adjusts the speed of the motor of the dragging device to make the traction speed return to the set range; if the mortar outflow is insufficient, the control instruction is sent to the electric proportional regulating valve, and the regulating valve increases the valve opening to increase the inflation pressure of the annular airbag 101, enhancing the extrusion strength of the elastic mortar reservoir 102, and further increasing the mortar outflow. This technical solution can achieve precise control of the traction speed and mortar outflow during the repair process, improve the stability and consistency of the repair quality, avoid repair defects caused by abnormal speed or flow, and ensure a more reliable repair effect for narrow cement pipelines.The magnetoelectric speed sensor is adopted to collect the traction speed data. Because of its high measurement accuracy, it can accurately obtain the real-time speed of the traction mechanism of the dragging device, provide a reliable basis for intelligent control, avoid uneven coverage of the repair mortar due to unstable speed, and ensure the uniform thickness of the repair layer. The electromagnetic flowmeter is used to monitor the outflow of the repair mortar. Its characteristics of being unaffected by various fluid properties and having high measurement accuracy can accurately feedback the mortar flow situation. Once the flow rate is abnormal, intelligent regulation can be triggered in time to ensure that the mortar fills the damaged area of the pipeline sufficiently and evenly, improving the repair effect. The industrial-grade single-chip microcomputer, as a data processor, with its powerful computing ability and rich interface resources, can quickly process the signals transmitted by the speed sensor and the flowmeter, make accurate judgments in time and issue control instructions, realizing the efficient intelligent control of the entire repair process. The variable frequency speed regulator is adapted to the motor of the dragging device and can accurately adjust the speed according to the instructions of the data processor, stably control the traction speed within a suitable range, cooperate with the mortar extrusion speed, avoid repair defects caused by speed mismatch, and improve the repair quality. The electro-hydraulic proportional regulating valve can accurately adjust the inflation pressure of the annular airbag 101. When the outflow of the mortar is insufficient, it can increase the pressure in time, enhance the extrusion of the elastic mortar reservoir 102, ensure the continuous and stable outflow of the mortar, ensure that the damaged area of the pipeline is fully repaired, and improve the overall repair effect and service life of the pipeline.

[0025] In another technical solution, the dragging device is an electric hoist, and its traction mechanism includes a servo motor, a reducer, and an electromagnetic brake; The output shaft of the servo motor is connected to the drum through the reducer, and the surface of the drum is provided with spiral grooves to adapt to the winding track of the pulling rope; The electromagnetic brake is integrated at the output end of the reducer and is used to lock or release the rotation of the drum in real time when the speed regulation module issues an instruction; The control interface of the electric hoist is connected to the data processor of the intelligent control system through the CAN bus, receives the digital control signal output by the speed regulation module, and feeds back the real-time traction speed data to the data processor.

[0026] In this technical solution, when the dragging device is an electric winch, the servo motor in its traction mechanism can be an AC servo motor, which features fast response speed and high control precision, and can accurately execute speed regulation commands. The reducer can be a gear reducer, which converts the high speed and low torque of the servo motor into the low speed and high torque required by the drum through gear meshing, meeting the power demand for the traction base to move in the pipeline. The electromagnetic brake can be a power-off electromagnetic brake, which is integrally installed at the output end of the reducer and can lock or release the rotation of the drum in real time through the on-off of electromagnetic force when the speed regulation module issues a command, realizing the fast start and stop control of the traction action. The surface of the drum is processed with spiral grooves adapted to the diameter of the pulling rope, and the pitch and depth of the spiral grooves are designed according to the winding requirements of the pulling rope to ensure that the pulling rope is neatly arranged on the drum without knotting. The control interface of the electric winch is connected to the data processor of the intelligent control system through the CAN bus. The CAN bus has the characteristics of strong anti-interference ability and fast data transmission rate, and can realize the reliable transmission of digital control signals and the feedback of real-time traction speed data. This technical solution uses an AC servo motor as the power source, and its high-precision speed and torque control characteristics can ensure that the traction speed is stable within the set range of 0.1 - 0.3 m / s, avoiding uneven coverage thickness of the repair mortar caused by speed fluctuations and improving the uniformity of the repair layer. The setting of the gear reducer can amplify the output torque of the servo motor, providing sufficient power for the traction base to move in the pipeline, adapting to the possible changes in frictional resistance on the inner wall of the pipeline, and ensuring the continuity of the repair operation. The electromagnetic brake is integrated at the output end of the reducer and can lock or release the drum instantly when the speed regulation module issues a command, ensuring timely response of the traction action, avoiding excessive movement or inaccurate positioning of the base caused by inertia, and improving the control precision during the repair process. The spiral groove design on the surface of the drum enables the pulling rope to be neatly wound along a predetermined trajectory, effectively preventing the pulling rope from getting tangled or knotted during the traction process and ensuring the smoothness of the traction process. Connecting the electric winch and the data processor through the CAN bus realizes the real-time and reliable interaction of control signals and speed data, providing a stable communication foundation for the intelligent control system to dynamically adjust traction parameters, thereby improving the automation control level and collaborative working ability of the entire repair system.

[0027] In another technical solution, the data processor receives in real time the traction speed signal output by the speed sensor and the mortar outflow signal output by the flowmeter; When the traction speed signal continuously exceeds the range of 0.1 - 0.3 m / s for 5 seconds, the data processor sends a first control command to the speed regulation module. The speed regulation module adjusts the output torque of the servo motor and controls the drum to rotate through the reducer, adjusting the traction speed to the reference value of 0.2 m / s. When the mortar outflow signal is lower than the preset threshold of 0.8 L / min, the data processor sends a second control instruction to the pressure regulating valve, and the pressure regulating valve increases the inflation pressure of the annular airbag 101 by adjusting the valve opening until the mortar outflow reaches 0.8 L / min.

[0028] In this technical solution, the data processor can use an industrial-grade PLC (programmable logic controller) or a high-performance single-chip microcomputer, which has multiple analog and digital input and output interfaces and can receive the traction speed signal output by the speed sensor and the mortar outflow signal output by the flowmeter in real time. The traction speed signal collected by the speed sensor in real time and the mortar outflow signal monitored by the flowmeter in real time are transmitted to the input port of the data processor through a shielded cable. When the traction speed signal continuously exceeds the range of 0.1 - 0.3 m / s for 5 seconds, the built-in logic control program of the data processor triggers the first control instruction and sends it to the speed regulation module through the communication interface. The speed regulation module can select a servo driver matching the servo motor. After receiving the instruction, it changes the output torque by adjusting the output current or voltage of the servo motor, which is transmitted to the reel through the gear transmission system of the reducer, thereby adjusting the reel speed and stably regulating the traction speed to the reference value of 0.2 m / s. When the mortar outflow signal is lower than the preset threshold of 0.8 L / min, the data processor generates a second control instruction and sends it to the pressure regulating valve. The pressure regulating valve can select an electro-hydraulic proportional pressure valve, which changes the air supply flow of the air inflation pump to the annular airbag 101 by adjusting the valve opening, thereby increasing the inflation pressure in the airbag and enhancing the extrusion strength on the elastic mortar reservoir 102 until the mortar outflow reaches the set value of 0.8 L / min. The data processor of this technical solution sets a judgment mechanism of "continuously exceeding the range for 5 seconds", which can effectively filter out instantaneous interference signals, avoid misoperation of the control system, and improve the stability and reliability of the control strategy; the traction speed reference value is set to 0.2 m / s, which is in the middle of the reasonable range of 0.1 - 0.3 m / s, providing a stable traction speed reference for the repair operation, ensuring that the extrusion speed of the repair mortar matches the moving speed of the base, and avoiding too thin a repair layer caused by too fast a speed or mortar accumulation caused by too slow a speed; the speed regulation module controls the traction speed by adjusting the output torque of the servo motor, which can dynamically match the power output according to the change of the friction resistance on the inner wall of the pipeline, ensuring the uniform movement of the base; the pressure regulating valve adjusts the airbag inflation pressure in real time according to the mortar flow signal, establishing a dynamic compensation mechanism between the mortar outflow and the airbag pressure, ensuring that the mortar can still be extruded at a stable flow rate when the pipeline is in different sections or the local resistance changes, avoiding insufficient filling of the damaged area caused by insufficient pressure or material waste caused by too high pressure, thereby improving the fine control level and repair quality consistency of the repair process.

[0029] In another technical solution, a pressure sensor is further installed inside the annular airbag 101 for real-time monitoring of the airbag pressure inside the annular airbag 101. The data processor has a built-in pressure-flow compensation model. When the airbag pressure reaches the upper limit value of 0.18 MPa while the mortar outflow rate is still lower than the threshold value of 0.8 L / min, a pause instruction for the dragging device is automatically triggered, and an artificial intervention alarm signal is generated. In this technical solution, the pressure sensor installed inside the annular airbag 101 can be a thin-film pressure sensor, which is small in size and high in measurement accuracy, can be installed conforming to the inner wall of the airbag, collect the air pressure data inside the airbag in real time, and transmit the signal to the data processor through a wire. The data processor can use an industrial-grade PLC or an embedded industrial control computer. The built-in pressure-flow compensation model is constructed based on experimental calibration data and can receive the signals of the pressure sensor, speed sensor, and flowmeter in real time. When the airbag pressure reaches the upper limit value of 0.18 MPa, the signal fed back by the pressure sensor triggers the logic judgment program of the data processor. If the mortar outflow rate is still lower than the threshold value of 0.8 L / min at this time, the data processor will immediately generate a pause instruction for the dragging device and send it to the electric control system of the electric hoist through the CAN bus or relay control circuit to stop the traction; at the same time, the data processor generates an artificial intervention alarm signal through the connected alarm device (such as an audible and visual alarm) to prompt the operator to check problems such as mortar mix ratio, pipeline blockage, or equipment failure on site. In this technical solution, a thin-film pressure sensor is set inside the annular airbag 101, which can monitor the airbag pressure in real time and accurately, provide real-time data support for the pressure-flow compensation model, and avoid the problem of untimely control caused by lagging pressure monitoring; the built-in pressure-flow compensation model of the data processor integrates parameters of pressure, flow rate, and traction speed to establish a dynamic adjustment mechanism of multivariable coupling, which can adaptively adjust the control strategy when the pipeline working conditions change; setting the upper limit value of the airbag pressure to 0.18 MPa can not only ensure that the airbag effectively squeezes the elastic mortar reservoir 102 but also prevent the airbag from being damaged or the inner wall of the pipeline from being extruded and deformed due to excessive pressure, ensuring the safety of the repair process; when the pressure reaches the upper limit and still cannot meet the flow rate requirement, a pause instruction and an alarm signal are automatically triggered, which can terminate the ineffective repair process in time, avoid material waste and repair defects, and at the same time provide an operation window for manual troubleshooting of equipment failures or special pipeline working conditions (such as severe blockage, deformation), improving the reliability and fault tolerance of the repair system.

[0030] In another technical solution, the construction and execution of the pressure-flow compensation model include the following steps: (a) Establish a non-linear mapping relationship between the airbag pressure P and the repair mortar flow rate Q based on experimental calibration data, and its mathematical model is: ; In the formula, k is the mortar rheological characteristic coefficient, P0 is the initial flow-starting pressure threshold, and α is the dynamic correction factor of the traction speed v on the flow rate. (b) During the repair process, the data of the pressure sensor, flowmeter, and traction speed inside the annular airbag 101 are collected in real time, and the model parameters k, P0, and α are updated online through the recursive least squares method to make the model adapt to the current pipeline conditions; (c) When the detected mortar outflow rate is lower than 0.8 L / min, calculate the target compensation pressure according to the current model , and generate a pressure regulation command, where Q threshold is the preset minimum threshold of 0.8 L / min for the repair mortar flow rate; (d) If P target ≤ 0.18 MPa, then control the pressure regulating valve to increase the pressure precisely according to P target ; if P target > 0.18 MPa, then trigger an artificial intervention alarm.

[0031] In this technical solution, the data processor can adopt an industrial-grade embedded controller or a high-performance PLC with data processing and algorithm operation capabilities. The built-in pressure-flow compensation model is realized through the following steps: First, test the repair mortar with different ratios in a laboratory environment, and use a pressure sensor, a flowmeter, and a speed sensor to collect multiple groups of data of the airbag pressure P, mortar flow rate Q, and traction speed v. Based on non-linear regression analysis, establish a mathematical model , where the initial values of k, P0, and α are determined through experimental calibration. During the repair process, the data processor receives the pressure data of the thin-film pressure sensor inside the annular airbag 101, the flow rate data of the electromagnetic flowmeter at the outlet of the connecting pipe 104, and the speed data of the magnetoelectric speed sensor on the traction mechanism in real time, and updates k, P0, and α online through the recursive least squares method to correct the model parameters to adapt to the real-time changes in pipeline inner wall roughness, mortar fluidity, etc. When the flowmeter monitors that the mortar outflow rate is lower than 0.8 L / min, the data processor calculates the target compensation pressure P target required to make the flow rate reach the threshold according to the current model. If P target ≤ 0.18 MPa, then send a command to the electro-hydraulic proportional pressure valve to precisely adjust the airbag inflation pressure; if P target>0.18 MPa, the control circuit is triggered to pause the dragging device, and an artificial intervention signal is generated by the acoustic-optic alarm. This technical solution quantifies the coupling relationship between the airbag pressure, the traction speed, and the mortar flow rate based on a non-linear mathematical model calibrated through experiments, providing a theoretical basis for dynamic compensation and solving the problem that traditional single-parameter control is difficult to adapt to complex working conditions. By updating the model parameters online through the recursive least squares method, the system can automatically adapt to actual situations such as the irregularity of the inner wall of the pipeline and the fluctuation of the rheological properties of the mortar, avoiding flow control deviations caused by changes in working conditions. A flow threshold of 0.8 L / min and a pressure upper limit of 0.18 MPa are set, which not only ensures that the repair mortar covers the damaged area with sufficient flow rate but also prevents damage to the inner wall of the pipeline caused by excessive airbag pressure, forming a closed-loop control system of "model prediction - real-time correction - safety protection". When the pressure adjustment reaches the upper limit and still cannot meet the flow rate requirement, it automatically triggers a pause and an alarm, providing a buffer mechanism for manual intervention to check for abnormal situations such as serious pipeline damage and mortar blockage, improving the working condition adaptability and fault handling ability of the repair system, and ensuring accurate material delivery and speed matching within a safe and controllable range during the repair process. The parameters (0.18 MPa, 0.8 L / min, 0.1 - 0.3 m / s) are all verified through systematic experiments, covering material properties, equipment limits, and working condition adaptability, ensuring the reliability and optimization of the technical solution.

[0032] In another technical solution, the diameter of the through hole 103 is 6 - 8 mm, and one is arranged every 15° along the circumferential direction of the base. In this technical solution, when manufacturing the base, professional drilling equipment is used to process the outer surface of the base. According to the angular interval of every 15°, through holes 103 with a diameter of 6 mm, 7 mm, or 8 mm are drilled. After drilling, the through holes 103 are polished and cleaned to ensure that their inner walls are smooth, avoiding blockage when the mortar flows out. Then, the connecting pipe 104 is hermetically connected to the elastic mortar storage 102 and the through hole 103 to prevent mortar leakage. This design of the through hole 103 enables the repair mortar to flow out evenly at an appropriate flow rate and pressure. The diameter range of 6 - 8 mm not only ensures sufficient flow space for the mortar but also avoids the problems of too fast mortar outflow and uneven distribution caused by too large an aperture. And arranging one through hole 103 every 15° along the circumferential direction can ensure that the mortar forms a continuous and uniform covering layer on the inner wall of the pipeline, effectively filling the damaged area of the pipeline, improving the quality and effect of the repair, and making the structure of the repaired pipeline more stable.

[0033] In another technical solution, the inflatable pump is a dual-channel linkage air pump. The two inflation channels are respectively connected to the two annular air bags 101, and a pressure balance module is built in the inflatable pump. When the air pressure in a single annular air bag 101 exceeds 0.15 MPa, the excess gas is automatically transferred to the other annular air bag 101. In this technical solution, a dual-channel linkage air pump with a suitable specification is selected, and its two inflation channels are respectively connected to the two annular air bags 101 through hoses with good pressure resistance and sealing performance. During the installation process, ensure that the connections are firm and there is no air leakage. The pressure balance module built in the inflatable pump uses a high-precision pressure sensor to monitor the air pressure in the two annular air bags 101 in real time. When it is detected that the air pressure in a single annular air bag 101 exceeds 0.15 MPa, the control unit in the pressure balance module will quickly control the reversing valve to act, and transfer the excess gas to the other annular air bag 101. The setting of the dual-channel linkage air pump and the pressure balance module ensures that the air pressure in the two annular air bags 101 is always balanced. This helps the base to run smoothly in the pipeline, avoiding the base from tilting or shifting due to excessive pressure on one side of the air bag, thus ensuring uniform extrusion of the elastic mortar reservoir 102, and enabling the repair mortar to be extruded stably and continuously from the through hole 103. At the same time, the balance of air pressure can also effectively protect the annular air bag 101, extend its service life, and reduce the risk of air bag damage caused by uneven air pressure.

[0034] In another technical solution, the outer arc surfaces of the two annular air bags 101 are covered with a rubber anti-slip layer with a thickness of 2-3 mm. In this technical solution, rubber materials with good wear resistance and elasticity such as nitrile rubber or neoprene are selected, and processed into rubber sheets with a thickness of 2-3 mm. Then, a professional adhesive or vulcanization process is used to closely attach the rubber sheets to the outer arc surfaces of the two annular air bags 101. During the attachment process, ensure that the rubber sheets are flat, without bubbles and wrinkles, to ensure good contact with the inner wall of the pipeline. The rubber anti-slip layer increases the friction between the annular air bag 101 and the inner wall of the pipeline, enabling the base to move more stably when being towed by the dragging device along the inner wall of the pipeline. Even if there are certain roughness differences or a small amount of accumulated water on the inner wall of the pipeline, it can effectively prevent the base from slipping or experiencing speed fluctuations. This ensures that during the entire repair process, the moving speed of the base can be accurately matched with the extrusion amount of the mortar, further improving the quality and efficiency of the repair, and ensuring the consistency and reliability of the repair effect.

[0035] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples described here.

Claims

1. A trenchless repair method for narrow cement pipelines, characterized in that, It includes the following steps: Step 1: Customize a base that matches the inner diameter size of the cement pipe to be repaired. Two parallel annular airbags are arranged in the middle of the base. Each annular airbag is connected to an air inflation pump. An elastic mortar reservoir is connected and arranged between the two annular airbags inside the base. Through holes are arranged on the outer surface of the base in a circumferential distribution. The elastic mortar reservoir is communicated with the through holes through a connecting pipe; Step 2: Inject repair mortar into the elastic mortar reservoir. Place the base into the cement pipe to be repaired. Fix and connect pulling ropes at both ends of the base. Install guiding pulleys at the inlet and outlet of the cement pipe to be repaired, and make the pulling ropes pass through the guiding pulleys and then be connected to an external dragging device; Step 3: Inject compressed air into the annular airbags through the air inflation pump, so that the annular airbags expand to tightly fit the inner wall of the pipe. At the same time, squeeze the elastic mortar reservoir, forcing the repair mortar to flow out of the through holes through the connecting pipe and fill the gap between the base and the inner wall of the pipe; Step 4: Start the dragging device, evenly traction the pulling ropes, drive the base to move along the inner wall of the pipe. During this process, the annular airbags maintain the extrusion of the elastic mortar reservoir, ensuring that the repair mortar continuously extrudes from the through holes and covers the damaged area inside the pipe; Step 5: After the pipe repair is completed, conduct a water storage inspection.

2. The trenchless repair method for narrow cement pipelines according to claim 1, characterized in that In the fourth step, the dragging device is connected to an intelligent control system. The intelligent control system includes a speed sensor, a flowmeter, and a data processor; The speed sensor is installed on the traction mechanism of the dragging device and is used to collect traction speed data in real time; The flowmeter is installed at the outlet of the connecting pipe of the elastic mortar reservoir and is used to monitor the outflow rate of the repair mortar in real time; The data processor receives the signals of the speed sensor and the flowmeter. When it detects that the traction speed deviates from the range of 0.1 - 0.3 m / s or the mortar outflow rate is lower than the preset threshold, it automatically generates a control instruction and sends it to the speed regulation module of the dragging device and the pressure regulating valve of the air inflation pump; The speed regulation module adjusts the traction speed to the set range according to the control instruction; The pressure regulating valve increases the inflation pressure of the annular airbags according to the control instruction to enhance the extrusion strength of the elastic mortar reservoir, thereby increasing the mortar outflow rate.

3. The trenchless repair method for narrow cement pipelines according to claim 2, characterized in that The dragging device is an electric hoist, and its traction mechanism includes a servo motor, a reducer, and an electromagnetic brake; The output shaft of the servo motor is connected to a drum through a reducer. The surface of the drum is provided with spiral grooves to adapt to the winding track of the pulling ropes; The electromagnetic brake is integrated at the output end of the reducer and is used to lock or release the rotation of the drum in real time when the speed regulation module issues an instruction; The control interface of the electric hoist is connected to the data processor of the intelligent control system through a CAN bus, receives the digital control signal output by the speed regulation module, and feeds back the real-time traction speed data to the data processor.

4. The trenchless repair method for narrow cement pipelines according to claim 3, characterized in that, The data processor receives the traction speed signal output by the speed sensor and the mortar outflow rate signal output by the flowmeter in real time; When the traction speed signal continuously exceeds the range of 0.1 - 0.3 m / s for 5 seconds, the data processor sends a first control instruction to the speed regulation module. The speed regulation module adjusts the output torque of the servo motor, controls the transmission of the drum through the reducer, and adjusts the traction speed to the reference value of 0.2 m / s. When the mortar outflow signal is lower than the preset threshold of 0.8 L / min, the data processor sends a second control instruction to the pressure regulating valve. The pressure regulating valve increases the inflation pressure of the annular airbag by adjusting the valve opening until the mortar outflow reaches 0.8 L / min.

5. The trenchless repair method for narrow cement pipelines according to claim 4, characterized in that A pressure sensor is also installed inside the annular airbag to continuously monitor the airbag pressure inside the annular airbag. The data processor has a built-in pressure-flow compensation model. When the airbag pressure reaches the upper limit value of 0.18 MPa and the mortar outflow is still lower than the threshold value of 0.8 L / min, it automatically triggers a pause instruction for the dragging device and generates an artificial intervention alarm signal.

6. The trenchless repair method for narrow cement pipelines according to claim 5, wherein, The construction and execution of the pressure-flow compensation model include the following steps: (a)Based on the experimental calibration data, a non-linear mapping relationship between the airbag pressure P and the repair mortar flow rate Q is established, and its mathematical model is: ; In the formula, k is the mortar rheological characteristic coefficient, P0 is the initial flow start pressure threshold, and α is the dynamic correction factor of the traction speed v on the flow rate. (b) During the repair process, continuously collect the data of the internal pressure sensor of the annular airbag, the data of the flowmeter, and the traction speed data, and online update the model parameters k, P0, and α through the recursive least squares method to make the model adapt to the current pipeline working conditions. (c) When the detected mortar outflow rate is lower than 0.8 L / min, calculate the target compensation pressure according to the current model , and generate a pressure adjustment instruction, where Q threshold is the preset minimum threshold 0.8 L / min for the flow rate of the repair mortar; (d) If P target ≤ 0.18 MPa, then control the pressure regulating valve to increase the pressure precisely according to P target ; if P target > 0.18 MPa, then trigger an artificial intervention alarm.

7. The trenchless repair method for narrow cement pipelines according to claim 1, characterized in that, The diameter of the through hole is 6 - 8 mm, and one is set every 15° along the circumferential direction of the base.

8. The trenchless repair method for narrow cement pipelines according to claim 1, characterized in that, The air inflation pump is a dual-channel linkage air pump. The two air inflation channels are respectively connected to the two annular airbags, and the air inflation pump has a built-in pressure balance module. When the air pressure of a single annular airbag exceeds 0.15 MPa, it automatically transfers the excess gas to the other annular airbag.

9. The trenchless repair method for narrow cement pipelines according to claim 1, characterized in that The outer arc surfaces of the two annular airbags are covered with a rubber anti-slip layer with a thickness of 2 - 3 mm.

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