Mud water shield constructs the pipeline of discharging mud and prevents deposit and quick method and system of unblocking broken stone of system

Abstract

The application discloses a kind of slurry shield slurry discharge pipeline anti-deposition and quick unblocking gravel method and system, belong to slurry shield construction technical field.For existing slurry discharge system relies on passive interception of grid failure, need manual shutdown disassembly pipe cleaning after blockage, low efficiency and big safety hazard problem, the application sets up centrifugal vortex gravel box in front section of slurry pump suction, constructs high-speed cyclone field by tangential inlet slurry, separates large heavy slag to bottom crushing cavity using density difference;Independent driving high-strength alloy crushing mechanism is used, combined with intelligent monitoring model based on pressure gradient, realize early warning and closed-loop automatic unblocking before blockage.The application does not need to stop and manual intervention, slurry discharge efficiency is improved by about 20%, completely eliminates slurry gushing safety hazard, adapts to a variety of complex strata, and installation transformation cost is low.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, specifically to a method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield. Background Technology

[0002] Slurry balance shield tunneling machines are core equipment for urban underground space development and the construction of tunnels across rivers and seas. Their slurry discharge system plays a crucial role in maintaining pressure balance at the excavation face and transporting cut excavated soil, and is often referred to as the "blood vessels" of the shield machine. When traversing boulders, hard rock, or complex strata, the cutterhead generates a large amount of large rocks and highly viscous mud cakes. These solid substances, once carried by the slurry flow into the slurry discharge pipeline, can easily cause pipeline blockage and slurry pump failure.

[0003] Existing technologies typically employ a primary screen in the slurry discharge system for passive interception. However, if the screen aperture is too large, it cannot effectively block large pieces of slag, while if the aperture is too small, it is easily clogged by mud cake and fine particles, leading to a significant decrease in slurry discharge efficiency. Once large pieces of slag break through the screen, they will accumulate in low-lying areas of the pipeline or become stuck at the impeller of the slurry pump, causing pump overload or even damage.

[0004] Currently, the main approach to dealing with blockages in the slurry discharge system is reactive: when a sudden drop in flow or pump overload is detected, the system must be stopped and depressurized first, followed by manual disassembly and cleaning of the pipeline. This "post-incident remedial" approach has many drawbacks: firstly, each cleaning session takes an average of more than 4 hours, severely impacting the efficiency of tunnel boring machines; secondly, there is a significant safety hazard of slurry gushing during pressurized pipeline operations; and finally, frequent shutdowns and pipeline disassembly accelerate equipment wear and increase maintenance costs.

[0005] Therefore, there is an urgent need to develop a technical solution that can achieve active separation, online crushing, and intelligent unblocking of large slag and stone, so as to fundamentally solve the clogging problem of the slurry discharge system of the slurry shield tunnel and improve construction efficiency and safety. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and system for preventing sedimentation and quickly unblocking and crushing rocks in the slurry discharge pipeline of a slurry shield tunnel. Based on the solid-liquid two-phase flow centrifugal sedimentation theory, a coupled processing mechanism of "cyclone classification-sedimentation capture-intelligent crushing" is constructed to achieve active defense and online removal of large solid phase materials in the slurry discharge pipeline without manual intervention or shutdown.

[0007] To achieve the above objectives, this invention provides a method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunnel, which is installed in front of the suction inlet of the shield tunnel slurry pump and includes the following steps: S1. Constructing a centrifugal vortex flow field: A centrifugal vortex crushing box body is set up in front of the main pump of slurry discharge. The tangential slurry feeding structure induces high-pressure slurry to form a high-speed vortex. Utilizing the density difference characteristics of solid-liquid two-phase flow, large heavy slag stones are allowed to settle against the wall and enter the crushing chamber at the bottom of the box under the action of centrifugal force. Light slag-carrying slurry flows directly to the slurry discharge pump through the central flow field. S2. Setting up an independent crushing mechanism: A crushing chamber is set up in the sedimentation and capture area at the bottom of the main body of the crushing box, with a high-strength alloy crushing component driven by an external independent high-torque motor. The crushing mechanism is decoupled from the power of the slurry pump. S3. Real-time monitoring of blockage precursors: Construct an intelligent control system to collect real-time data on the pressure before the slurry pump and the pressure difference between the inlet and outlet of the crushed stone box, calculate the pressure mutation rate and flow resistance change, and establish a blockage precursor criterion function. S4. Execute closed-loop automatic unblocking: When the value of the blockage precursor judgment function exceeds the set alarm threshold, it is determined that there is a risk of large rock deposits or mud cake retention. The PLC controller automatically starts the crushing motor to crush the sediment. After the pressure and pressure difference return to the normal range, the crushing motor is automatically stopped and the normal overcurrent state is restored.

[0008] Preferably, in step S1, for particles with a diameter of... Density is The centrifugal settling velocity of solid particles in a swirling flow field The following dynamic relationship must be satisfied: in, The density of the mud fluid. For tangential velocity, The dynamic viscosity of the mud. The swirl radius is determined; through flow field design, large heavy slag stones are ensured to be within acceptable limits. of The flow velocity is much greater than the radial velocity, so the material settles against the wall and enters the crushing chamber at the bottom of the tank under the action of centrifugal force, while the lightweight sludge carrying the slag passes directly through the pump through the central flow field.

[0009] Preferably, in step S2, the geometry of the crushing chamber follows the "biting-shearing" mechanical model, and the high-strength alloy crushing component adopts a tungsten carbide inlay structure to crush large rocks falling into the crushing chamber to below the critical particle size that the slurry pump can pass through.

[0010] Preferably, in step S3, the pressure before the pump is collected in real time. Pressure difference with the crushing box Define the congestion precursor criterion function Then the criterion function for the precursory blockage is: in, Characterizing the stress mutation rate, Normal flow resistance. , These are the weighting coefficients.

[0011] Preferably, in step S4, when the detection At that time, among them If the alarm threshold is set and a risk of large rock deposits or mud cake buildup is detected, the PLC controller will automatically execute the following logic: (1) Start the crushing motor to forcefully crush the sediment; (2) After crushing is completed, monitoring is conducted. Recovering steadily and Once the current returns to the normal range, the motor will automatically stop and the normal overcurrent condition will be restored.

[0012] A system for preventing sedimentation and rapidly unclogging debris in the slurry discharge pipeline of a slurry shield tunneling machine, the system being installed upstream of the slurry discharge pump inlet of the shield tunneling machine, comprising: The main body of the centrifugal vortex crusher adopts a tangential slurry feeding structure, forming a high-speed swirling flow field inside. It utilizes the density difference between the solid and liquid phases to separate large heavy slag stones from light slag-carrying slurry. The bottom of the box is equipped with a sedimentation capture zone and a crushing chamber. An independently driven crushing mechanism is located inside the crushing chamber and includes a high-strength alloy crushing component and an independent high-torque motor located outside the housing. The crushing mechanism is decoupled from the power of the slurry pump. The intelligent monitoring system includes a first pressure sensor installed before the slurry pump, a second pressure sensor installed at the inlet of the crushed stone box, and a third pressure sensor installed at the outlet of the crushed stone box, for real-time collection of pressure data. The PLC controller is electrically connected to the pressure sensor and the crushing motor, and has a built-in blockage precursor judgment model and closed-loop automatic unblocking control logic.

[0013] Preferably, the upper part of the centrifugal vortex crusher is a cylindrical swirling zone, the lower part is a conical sedimentation zone, the tangential slurry inlet is located at the upper part of the cylindrical swirling zone, and the central slurry outlet is located at the center of the top of the crusher.

[0014] Preferably, the high-strength alloy crushing component has a toothed jaw structure, which is made of tungsten carbide hard alloy inlaid on an alloy steel substrate, and the tooth-jaw gap can be adjusted according to the maximum particle size allowed to pass through the slurry pump.

[0015] Preferably, the PLC controller can automatically adjust the weighting coefficients of the pre-clogging criterion function according to different formation conditions and mud parameters. , and alarm threshold .

[0016] Preferably, the system also includes a human-machine interface for displaying real-time pressure curves, system operating status and alarm information, and supports manual control of the start and stop of the crushing motor.

[0017] The advantages of this invention compared to the prior art are: 1. Active sorting and anti-clogging with high interception efficiency: The centrifugal vortex flow field utilizes the density difference between the solid and liquid phases to achieve automatic sorting of slag without power, which can efficiently intercept large pieces of heavy slag and solve the shortcomings of traditional grid passive interception, such as easy clogging and low interception efficiency.

[0018] 2. Precise crushing and energy saving with low equipment wear: The independent crushing mechanism works only on the large pieces of slag after separation, avoiding energy waste caused by indiscriminate crushing; at the same time, the high-strength alloy jaw teeth with tungsten carbide inlay structure have strong wear resistance and significantly extend the service life of the equipment.

[0019] 3. Intelligent and proactive unblocking with significant efficiency improvement: The pressure gradient-based monitoring model can identify early signs of blockage and provide proactive warnings; the unblocking process requires no machine shutdown or manual intervention, achieving "millisecond-level monitoring and minute-level processing", improving slurry discharge efficiency by about 20%.

[0020] 4. Safe, reliable, and widely adaptable: It completely eliminates the safety hazards of mud slurry gushing caused by manual pressurized pipe dismantling and cleaning; it can be adapted to different diameter slurry discharge pipes and shield machine models, and is compatible with a variety of complex working conditions such as boulders, hard rock, and composite strata.

[0021] 5. Easy installation and low modification cost: The system is installed in series at the front of the slurry pump suction port, without the need for major modifications to the original slurry system. The installation and commissioning time of a single unit is short and the modification cost is low, making it easy to promote and apply in existing projects. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure and flow field simulation of the present invention; Figure 2 This is a force analysis diagram of the centrifugal settlement of large rocks in this invention; Figure 3 This is a flowchart of the intelligent unblocking control logic of the present invention. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0025] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings.

[0027] like Figure 1 As shown, this invention discloses a method and system for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunnel. The gravel box in the system utilizes a coupled processing mechanism of "cyclone classification - sedimentation capture - intelligent crushing" based on the solid-liquid two-phase flow centrifugal sedimentation theory to achieve active defense and online removal of large solid particles in the slurry discharge pipeline.

[0028] The method of the present invention includes the following steps and structure: S1. Construct a centrifugal vortex flow field structure. A centrifugal vortex crusher body is installed upstream of the main slurry pump. The body adopts a tangential slurry inlet structure to induce high-pressure slurry to form a high-speed vortex. Utilizing the density difference characteristics of the solid-liquid two-phase flow, a particle classification motion equation is established. For particles with a diameter of... Density is The centrifugal settling velocity of solid particles in a swirling flow field The following dynamic relationship must be satisfied: in, The density of the mud fluid. For tangential velocity, The dynamic viscosity of the mud. The swirl radius is used. Through flow field design, the flow of large, heavy slag stones is ensured. of The flow velocity is much greater than the radial velocity, so the material settles against the wall and enters the crushing chamber at the bottom of the tank under the action of centrifugal force, while the lightweight sludge carrying the slag passes directly through the pump through the central flow field.

[0029] S2. An independently driven high-strength alloy crushing mechanism is installed. A crushing chamber is located in the sediment capture zone at the bottom of the housing, containing built-in high-strength alloy jaws (such as a tungsten carbide inlaid structure). The crushing mechanism is driven by an independent high-torque motor outside the housing, decoupled from the slurry pump's power. The crushing chamber geometry follows a "biting-shear" mechanical model, ensuring that large pieces of rock are crushed to the critical particle size allowed by the slurry pump. the following.

[0030] S3. Establish an intelligent monitoring and triggering model based on pressure gradient. Construct an intelligent control system to collect the pressure before the pump in real time. Pressure difference with the crushing box Define the congestion precursor criterion function. : in, Characterizing the stress mutation rate, Normal flow resistance. , These are the weighting coefficients.

[0031] S4. Implement a closed-loop automatic congestion removal strategy. When the system detects... ( When the alarm threshold is set, it is determined that there is a risk of large rock deposits or mud cake retention. The PLC controller automatically executes the following logic: (1) Start the crushing motor to forcefully crush the sediment; (2) After crushing is completed, monitor the Recovering steadily and Once the current returns to the normal range, the motor will automatically stop and the normal overcurrent condition will be restored.

[0032] To more clearly illustrate the specific embodiments of the present invention, several examples are provided below: Taking the construction of a large-diameter slurry shield tunnel in a certain sea-crossing tunnel project as an example, the strata contain a large number of granite boulders.

[0033] S1. Device Installation and Parameter Setting. The cyclone crusher of this invention is installed in series at the slurry inlet pipe of the slurry pump. The slurry density is set. The maximum allowable particle size of the slurry pump .

[0034] S2, centrifugal separation operation. The mud is... The particles enter the chamber tangentially at high speed. According to the formula, the centrifugal force on rock fragments with a diameter greater than 50mm is several times that of the fluid drag force, causing them to be quickly thrown against the chamber wall and slide down to the bottom crushing chamber; while the fluid plastic clay blocks with a density close to that of mud flow directly out with the mainstream, avoiding ineffective crushing.

[0035] S3. Intelligent Monitoring and Triggering. The system monitors the tunneling process in real time. At a certain moment, it detects the pressure before the pump. The pressure abnormally increased from 0.2 MPa to 0.35 MPa within 5 seconds, and the pressure difference... Exceeding the set threshold. Calculation criteria. The "high-risk" signal is triggered, indicating that large rocks are accumulating at the pump inlet.

[0036] S4. Automatic Crushing and Unblocking. The system immediately starts the independent motor, driving the high-strength alloy jaw teeth to operate at a low speed and high torque of 60 rpm. After 15 seconds of crushing, large rocks are pulverized into stone chips and discharged.

[0037] Implementation results: The pressure curve shows that after starting the crusher... The pressure quickly returned to the 0.2MPa baseline without any pump blockage. Compared to traditional manual cleaning methods (averaging 4 hours per cycle), this invention achieves "millisecond-level monitoring and minute-level processing," eliminating the need for the tunnel boring machine to stop during the entire process. This increases slurry discharge efficiency by approximately 20% and completely avoids the safety risks associated with manual pipe dismantling.

[0038] Finally, any aspects not fully described in this invention utilize existing mature products and technologies.

[0039] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunnel, characterized in that: Installed at the front of the slurry pump suction port of the tunnel boring machine, the process includes the following steps: S1. Constructing a centrifugal vortex flow field: A centrifugal vortex crushing box body is set up in front of the main pump of slurry discharge. The tangential slurry feeding structure induces high-pressure slurry to form a high-speed vortex. Utilizing the density difference characteristics of solid-liquid two-phase flow, large heavy slag stones are allowed to settle against the wall and enter the crushing chamber at the bottom of the box under the action of centrifugal force. Light slag-carrying slurry flows directly to the slurry discharge pump through the central flow field. S2. Setting up an independent crushing mechanism: A crushing chamber is set up in the sedimentation and capture area at the bottom of the main body of the crushing box, with a high-strength alloy crushing component driven by an external independent high-torque motor. The crushing mechanism is decoupled from the power of the slurry pump. S3. Real-time monitoring of blockage precursors: Construct an intelligent control system to collect real-time data on the pressure before the slurry pump and the pressure difference between the inlet and outlet of the crushed stone box, calculate the pressure mutation rate and flow resistance change, and establish a blockage precursor criterion function. S4. Execute closed-loop automatic unblocking: When the value of the blockage precursor judgment function exceeds the set alarm threshold, it is determined that there is a risk of large rock deposits or mud cake retention. The PLC controller automatically starts the crushing motor to crush the sediment. After the pressure and pressure difference return to the normal range, the crushing motor is automatically stopped and the normal overcurrent state is restored.

2. The method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunneling machine according to claim 1, characterized in that: In step S1, for particles with a diameter of Density is The centrifugal settling velocity of solid particles in a swirling flow field The following dynamic relationship must be satisfied: in, The density of the mud fluid. For tangential velocity, The dynamic viscosity of the mud. The swirl radius is determined; through flow field design, large heavy slag stones are ensured to be within acceptable limits. of The flow velocity is much greater than the radial velocity, so the material settles against the wall and enters the crushing chamber at the bottom of the tank under the action of centrifugal force, while the lightweight sludge carrying the slag passes directly through the pump through the central flow field.

3. The method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunneling machine according to claim 1, characterized in that: In step S2, the geometry of the crushing chamber follows the "biting-shearing" mechanical model, and the high-strength alloy crushing component adopts a tungsten carbide inlay structure to crush large rocks falling into the crushing chamber to below the critical particle size that the slurry pump can pass through.

4. The method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunneling machine according to claim 1, characterized in that: In step S3, the pressure before the pump is collected in real time. Pressure difference with the crushing box Define the congestion precursor criterion function Then the criterion function for the precursory blockage is: in, Characterizing the stress mutation rate, Normal flow resistance. , These are the weighting coefficients.

5. The method for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunneling machine according to claim 1, characterized in that: In step S4, when it is detected At that time, among them If the alarm threshold is set and a risk of large rock deposits or mud cake buildup is detected, the PLC controller will automatically execute the following logic: (1) Start the crushing motor to forcefully crush the sediment; (2) After crushing is completed, monitoring is conducted. Recovering steadily and Once the current returns to the normal range, the motor will automatically stop and the normal overcurrent condition will be restored.

6. A system for preventing sedimentation and rapidly unblocking gravel in the slurry discharge pipeline of a slurry shield tunnel, characterized in that: The system is installed in front of the suction inlet of the shield tunnel grout pump and includes: The main body of the centrifugal vortex crusher adopts a tangential slurry feeding structure, forming a high-speed swirling flow field inside. It utilizes the density difference between the solid and liquid phases to separate large heavy slag stones from light slag-carrying slurry. The bottom of the box is equipped with a sedimentation capture zone and a crushing chamber. An independently driven crushing mechanism is located inside the crushing chamber and includes a high-strength alloy crushing component and an independent high-torque motor located outside the housing. The crushing mechanism is decoupled from the power of the slurry pump. The intelligent monitoring system includes a first pressure sensor installed before the slurry pump, a second pressure sensor installed at the inlet of the crushed stone box, and a third pressure sensor installed at the outlet of the crushed stone box, for real-time collection of pressure data. The PLC controller is electrically connected to the pressure sensor and the crushing motor, and has a built-in blockage precursor judgment model and closed-loop automatic unblocking control logic.

7. The anti-deposition and rapid unblocking system for slurry discharge pipelines of slurry shield tunnels according to claim 6, characterized in that: The upper part of the centrifugal vortex crusher is a cylindrical swirling zone, and the lower part is a conical sedimentation zone. The tangential slurry inlet is located at the upper part of the cylindrical swirling zone, and the central slurry outlet is located at the center of the top of the box.

8. The anti-deposition and rapid unblocking system for slurry discharge pipelines of slurry shield tunnels according to claim 6, characterized in that: The high-strength alloy crushing component has a toothed jaw structure, which is made of tungsten carbide hard alloy embedded in an alloy steel substrate. The gap between the teeth and jaws can be adjusted according to the maximum particle size allowed to pass through the slurry pump.

9. The anti-deposition and rapid unblocking system for slurry discharge pipelines of slurry shield tunnels according to claim 6, characterized in that: The PLC controller can automatically adjust the weighting coefficients of the pre-clogging criterion function according to different formation conditions and mud parameters. , and alarm threshold .

10. The anti-deposition and rapid unblocking system for slurry discharge pipelines of slurry shield tunnels according to claim 6, characterized in that: It also includes a human-machine interface for displaying real-time pressure curves, system operating status and alarm information, and supports manual control of the crushing motor to start and stop.

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