Extra-large-diameter slurry shield deslagging parameter optimization method, system and equipment and storage medium

Abstract

The invention discloses an ultra-large-diameter slurry shield deslagging parameter optimization method, system and device and a storage medium. The method comprises the following steps that a three-dimensional model is constructed; establishing a motion simulation model; the motion simulation model solves a flow process equation of a slurry fluid phase and a motion control equation of a rock slag particle phase according to the deslagging parameters, so that flow field distribution characteristics and rock slag migration behaviors in the excavation bin and the air cushion bin are obtained; obtaining an evaluation index of the deslagging performance, and judging whether the evaluation index meets a preset requirement or not. According to the method, a fluid phase flow equation and a particle phase motion control equation are solved by utilizing the simulation model, and an interaction mechanism of the slurry and the rock slag is defined, so that simulation is closer to a real situation; and dynamic adaptation of slag discharge parameters with a complex pipe network system and actual construction working conditions is realized. The probability of detention and accumulation of rock slag at the bottoms of the excavation bin and the air cushion bin is remarkably reduced, equipment abrasion is reduced, abnormal tunneling parameters are avoided, and stability and continuity of shield tunneling are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) technology, and in particular, to a method, system, equipment, and storage medium for optimizing slag discharge parameters in ultra-large diameter slurry TBMs. Background Technology

[0002] Slurry shield tunneling, with its advantages of strong adaptability to complex geological conditions and high tunneling stability, is widely used in large-scale underground projects such as river-crossing and sea-crossing tunnels and urban underground utility tunnels. During slurry shield tunneling, the rock debris generated by the cutterhead cutting the strata needs to be carried by circulating slurry and continuously discharged to the surface for treatment through a muck removal system. The smoothness of the muck removal process directly determines the stability, continuity, and construction efficiency of the shield tunneling, and is a core and critical aspect of slurry shield tunneling.

[0003] As the scale of underground engineering continues to expand, the diameter of tunnel boring machines (TBMs) is gradually developing towards ultra-large sizes. Simultaneously, construction conditions are becoming increasingly complex. To meet multiple requirements, such as cutterhead cooling and flushing, pressure balance in the excavation chamber, pressure stabilization in the air cushion chamber, and efficient transport of rock debris, TBMs are typically equipped with a complex slurry pipeline system. This system generally consists of a main slurry inlet pipeline, multi-stage branch flushing pipelines, slurry discharge pipelines, and internal circulation pipelines. These pipelines work together to achieve the circulation of slurry between the excavation chamber, air cushion chamber, and surface treatment system, thereby completing the transport and discharge of rock debris. However, in the actual construction of ultra-large diameter slurry shields, due to the complex structure of the slurry pipeline system, the large number of branch pipelines, and the uneven flow distribution among the branches, the flow field of the slurry in the excavation chamber and air cushion chamber exhibits significant spatial non-uniformity. Such flow field distribution defects easily lead to the accumulation of rock debris in areas such as the excavation chamber or the bottom of the air cushion chamber. This not only significantly reduces the efficiency of debris removal and affects the tunneling progress, but also exacerbates the wear and tear on the cutterhead, pipelines, and chamber structure. It can even cause safety hazards such as pressure fluctuations in the excavation chamber and abnormal tunneling parameters, seriously restricting the safety and efficiency of ultra-large diameter slurry shield tunneling. To solve the above-mentioned debris removal problem, some optimization schemes for slurry shield tunneling debris removal parameters have emerged in the existing technology, but these schemes still have obvious limitations. On the one hand, existing optimization methods mostly focus on the analysis and optimization of local pipelines, single chambers, or specific structural forms. They often assume that the operating conditions of each branch in the pipeline network system are relatively uniform, failing to fully consider the comprehensive impact of the complex pipeline network system as a whole on the flow field structure and rock debris migration behavior in the excavation chamber and air cushion chamber. This results in insufficient comprehensiveness and accuracy of the optimization analysis, making it difficult to fundamentally solve the problems of non-uniform flow field and rock debris accumulation. On the other hand, some optimization schemes rely on on-site construction experience parameters or are designed for specific engineering conditions. They lack adaptability to different geological conditions, different shield structures and different pipeline layouts, have poor versatility, and cannot provide reliable guidance for optimizing slag discharge parameters for various ultra-large diameter slurry shield tunneling projects. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method, system, equipment, and storage medium for optimizing the slag discharge parameters of ultra-large diameter slurry shield tunneling machines.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for optimizing slag removal parameters in ultra-large diameter slurry shield tunneling machines includes the following steps: S1, constructing a three-dimensional model including the excavation chamber, air cushion chamber, cutterhead, and slurry pipeline system; S2, based on the three-dimensional model, establishing a two-phase coupled motion simulation model of the slurry fluid phase and the rock debris particle phase to simulate the slurry flow and rock debris movement process under the action of the slurry pipeline system; S3, setting initial slag removal parameters; S4, the motion simulation model solves the flow process equation of the slurry fluid phase and the motion control equation of the rock debris particle phase according to the slag removal parameters, obtaining the interaction between the slurry fluid phase and the rock debris particle phase, thereby obtaining the flow field distribution characteristics and rock debris migration behavior in the excavation chamber and air cushion chamber; S5, obtaining the evaluation index of slag removal performance, and judging whether the evaluation index meets the preset requirements: if yes, then the current slag removal parameters are taken as the optimized slag removal parameters; if not, then the flow field distribution characteristics and rock debris migration behavior are analyzed to obtain the direction of slag removal improvement, and the slag removal parameters are adjusted according to the direction of slag removal improvement, and then returning to step S4.

[0006] Furthermore, the flow process equation is as follows: ; ; This represents the volume fraction of the mud phase. t For time, For fluid velocity, p For mud pressure, For mud density, It is the shear stress tensor; It is the interaction force between the two phases. This is the acceleration due to gravity.

[0007] Furthermore, the governing equations for the motion of the rock slag particle phase are described as follows: ; ; ; in ， and These are the contact force, damping force, and torque between rock slag particles and other particles, respectively. ， and These are the contact force, damping force, and torque between the rock slag particles and the equipment wall; It is the force exerted by the mud on the particles, and ; ， ， and These are the particle's mass, velocity, moment of inertia, and angular velocity, respectively. The density of rock slag particles, The diameter of the rock slag particles, Equivalent viscosity of mud This is the drag coefficient. It is the particle Reynolds number. This refers to the mud velocity.

[0008] Furthermore, the rock slag particle phase is modeled using a multi-size particle group, with different particle sizes set according to a preset mass ratio or volume fraction ratio.

[0009] Furthermore, the evaluation indicators for the slag discharge performance include at least one of the following: the cumulative amount of rock slag retained in the bin, the average movement speed of rock slag particles, the mass of rock slag passing through the slag discharge inlet per unit time, and the coverage ratio of rock slag in the bottom area of ​​the bin.

[0010] Furthermore, the analysis of flow field distribution characteristics and rock debris migration behavior to obtain directions for improving slag discharge includes at least: analyzing the low-speed flow region of rock debris in the bin and determining that the direction for improving slag discharge is to increase the amount of mud flushing in the low-speed flow region.

[0011] Furthermore, the slag discharge parameters include at least the tunneling parameters, the flow distribution ratio of each branch pipeline, and the operating parameters of the internal circulation pipeline.

[0012] This invention also proposes an optimization system for slag removal parameters of ultra-large diameter slurry shield tunneling machines, comprising: a three-dimensional model construction module for constructing a three-dimensional model including the excavation chamber, air cushion chamber, cutterhead, and slurry pipeline system; a motion simulation model establishment module for establishing a two-phase coupled motion simulation model of the slurry fluid phase and the rock debris particle phase based on the three-dimensional model; an initial setting module for inputting and setting initial slag removal parameters; a simulation calculation module for the motion simulation model to solve the flow process equation of the slurry fluid phase and the motion control equation of the rock debris particle phase according to the slag removal parameters, to obtain the interaction between the slurry fluid phase and the rock debris particle phase, thereby obtaining the flow field distribution characteristics and rock debris migration behavior in the excavation chamber and air cushion chamber, the interaction including at least the interaction force; and a judgment and adjustment module for obtaining evaluation indicators of slag removal performance, judging whether the evaluation indicators meet the preset requirements: if yes, then the current slag removal parameters are taken as the optimized slag removal parameters; if no, then the flow field distribution characteristics and rock debris migration behavior are analyzed to obtain the direction of slag removal improvement, and the slag removal parameters are adjusted according to the direction of slag removal improvement.

[0013] The present invention also proposes an electronic device, including a processor and a memory, wherein the memory is used to store program code and transmit the program code to the processor; the processor is used to execute a method for optimizing the slag discharge parameters of ultra-large diameter slurry shield tunneling according to the instructions in the program code.

[0014] The present invention also proposes a storage medium storing a computer program, which, when executed by a processor, implements a method for optimizing slag discharge parameters of ultra-large diameter slurry shield tunnels.

[0015] The present invention has the following beneficial effects: This method achieves accurate characterization of the flow field and rock debris migration behavior across the entire system, overcoming the limitations of localized analysis. Step S1 constructs an integrated 3D model encompassing the excavation chamber, air cushion chamber, cutterhead, and mud pipeline network system. This overcomes the shortcomings of existing technologies that only model local pipelines or single chambers, fully replicating the collaborative working scenario of complex pipeline networks such as the main slurry inlet pipeline and multi-level branch flushing pipelines. Combined with the two-phase coupled motion simulation model of mud fluid phase and rock debris particle phase established in step S2, it can realistically simulate the coupled motion process of mud and rock debris under the action of the mud pipeline network system, rather than assuming uniform operating conditions in each branch. This accurately captures the spatial distribution characteristics of the flow field and rock debris migration within the excavation chamber and air cushion chamber, providing a comprehensive and reliable data analysis foundation for parameter optimization and fundamentally solving the optimization failure problem caused by the one-sidedness of existing optimization analyses. Step S4 utilizes a simulation model to solve the fluid phase flow equations and particle phase motion control equations, clarifying the interaction mechanism between mud and rock debris, making the simulation closer to reality. Combined with the evaluation index judgment and iterative adjustment logic in step S5, the slag discharge parameters can be optimized specifically, rather than relying on empirical parameters or specific working condition data. This achieves dynamic adaptation of slag discharge parameters to complex pipeline systems and actual construction conditions. The optimized slag discharge parameters can improve the spatial non-uniformity of the flow field within the chamber, enhance the mud's ability to carry rock debris, significantly reduce the probability of rock debris accumulation at the bottom of the excavation chamber and air cushion chamber, thereby reducing equipment wear, avoiding abnormal tunneling parameters, and ensuring the stability and continuity of shield tunneling. This method achieves parameter optimization based on a three-dimensional model and two-phase coupled simulation, and is not limited to specific geological conditions, shield structures, or pipeline layouts, enhancing the versatility and adaptability of the optimization scheme and broadening the application scenarios of the technology.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall process of the method of the present invention; Figure 2 This is a schematic diagram of the CFD-DEM coupling model; Figure 3 This is the curve showing the effect of cutterhead rotation speed on slag discharge performance. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0022] Please refer to Figure 1 The present invention provides a preferred embodiment of a method for optimizing the slag discharge parameters of an ultra-large diameter slurry shield tunnel, comprising steps S1, S2, S3, S4 and S5.

[0023] S1. Construct a 3D model including the excavation chamber, air cushion chamber, cutterhead, and mud piping system. The mud piping system includes the main mud inlet pipeline, branch flushing pipelines, mud discharge pipelines, and internal circulation pipelines.

[0024] S2. Based on the aforementioned three-dimensional model, a two-phase coupled motion simulation model of the mud fluid phase and the rock debris particle phase is established to simulate the mud flow and rock debris movement process under the action of the mud pipeline system. During the simulation, rock debris particles are continuously generated at the cutterhead excavation face, and their generation rate is related to the shield tunneling parameters to simulate the continuous generation process of rock debris during actual tunneling.

[0025] S3 sets the initial slag discharge parameters.

[0026] S4, the motion simulation model solves the flow process equations of the mud fluid phase and the motion control equations of the rock debris particle phase based on the slag discharge parameters, obtaining the interaction between the mud fluid phase and the rock debris particle phase, thereby obtaining the flow field distribution characteristics and rock debris migration behavior within the excavation chamber and air cushion chamber. In the motion simulation model, the mud is treated as a continuous medium. Based on the rheological characteristics of the mud, the mud fluid model is set as either a Newtonian fluid or a non-Newtonian fluid model to adapt to changes in mud performance under different construction conditions. The rock debris in the motion simulation model is treated as a discrete particle group. Its motion process in the mud is described by the particle translational and rotational control equations, considering the contact and collision effects between particles and between particles and the equipment wall. By coupling the equations of the mud fluid phase and the motion control equations of the rock debris particle phase—two different phases—the interaction and influence between them are revealed, providing a scientific basis for motion simulation and establishing a two-phase coupled analysis framework for mud and rock debris.

[0027] S5. Obtain the evaluation index of slag discharge performance and determine whether the evaluation index meets the preset requirements: if yes, then use the current slag discharge parameters as the optimized slag discharge parameters; if no, then analyze the flow field distribution characteristics and rock slag migration behavior to obtain the direction of slag discharge improvement. Based on the direction of slag discharge improvement, adjust the slag discharge parameters and return to step S4.

[0028] This invention provides a method for optimizing slag discharge parameters in ultra-large diameter slurry shield tunneling machines, achieving accurate characterization of the flow field and slag migration behavior of the entire system and overcoming the limitations of local analysis. Step S1 constructs an integrated three-dimensional model encompassing the excavation chamber, air cushion chamber, cutterhead, and slurry pipeline system, overcoming the shortcomings of existing technologies that only model local pipelines or single chambers. This fully replicates the collaborative working scenario of complex pipeline networks such as the main slurry inlet pipeline and multi-level branch flushing pipelines. Combined with the two-phase coupled motion simulation model of the slurry fluid phase and slag particle phase established in step S2, it can realistically simulate the coupled motion process of slurry and slag under the action of the slurry pipeline system, rather than assuming uniform operating conditions in each branch. This accurately captures the spatial distribution characteristics of the flow field and slag migration within the excavation chamber and air cushion chamber, providing a comprehensive and reliable data analysis foundation for parameter optimization and fundamentally solving the optimization failure problem caused by the one-sidedness of existing optimization analyses. Step S4 utilizes a simulation model to solve the fluid phase flow equations and particle phase motion control equations, clarifying the interaction mechanism between the drilling mud and rock debris, thus making the simulation closer to reality. Combined with the evaluation index judgment and iterative adjustment logic in step S5, the slag discharge parameters can be optimized in a targeted manner, rather than relying on empirical parameters or specific working condition data. This achieves dynamic adaptation of the slag discharge parameters to complex pipeline systems and actual construction conditions. The optimized slag discharge parameters can improve the spatial non-uniformity of the flow field within the chamber, enhance the drilling mud's ability to carry rock debris, significantly reduce the probability of rock debris accumulation at the bottom of the excavation chamber and air cushion chamber, thereby reducing equipment wear, avoiding abnormal tunneling parameters, and ensuring the stability and continuity of shield tunneling.

[0029] This method optimizes parameters based on a 3D model and two-phase coupled simulation. It is not limited to specific geological conditions, shield structures, or pipeline layouts, and can adapt to the needs of different engineering scenarios by adjusting initial parameters (step S3). The iterative optimization logic (step S5) dynamically adjusts the slag discharge parameters according to the flow field characteristics and rock debris migration behavior under different working conditions. This overcomes the bottlenecks of poor universality and weak adaptability of existing solutions, providing standardized and replicable slag discharge parameter optimization guidance for various ultra-large diameter slurry shield tunneling projects. This reduces the reliance on experience and improves construction efficiency and safety. By precisely optimizing slag discharge parameters, while improving slag discharge efficiency and ensuring tunneling continuity, it can effectively control parameters such as slurry circulation flow rate and pressure, reducing slurry consumption and equipment energy consumption. Simultaneously, it reduces the risks of equipment wear and downtime caused by rock debris accumulation, reducing maintenance costs and project delays, providing technical support for the efficient and economical construction of ultra-large diameter slurry shield tunneling projects.

[0030] In some embodiments of the present invention, the flow process equation is as follows: ; ; This represents the volume fraction of the mud phase. t For time, For fluid velocity, p For mud pressure, For mud density, It is the shear stress tensor; For divergence operators, It is the interaction force between the two phases. This is the acceleration due to gravity.

[0031] The flow process equations for the mud fluid phase were clarified. Through the quantitative definitions of key physical quantities such as volume fraction, fluid velocity, pressure, density, and shear stress tensor, and combined with the coupling consideration of the two-phase interaction force and gravitational acceleration, a precise mathematical basis was provided for the flow field simulation calculation in step S4. This made the simulation results of the flow field distribution characteristics within the excavation chamber and air cushion chamber more closely resemble the actual construction scenario, providing a reliable fluid dynamics foundation for subsequent rock debris migration behavior analysis and parameter optimization, and improving the calculation accuracy and reliability of the entire optimization method.

[0032] In a specific embodiment of the present invention, the motion control equation of the rock slag particle phase is described as follows: ; ; ; in ， and These are the contact force, damping force, and torque between rock slag particles and other particles, respectively. ， and These are the contact force, damping force, and torque between the rock slag particles and the equipment wall; It is the force exerted by the mud on the particles, and ; ， ， and These are the particle's mass, velocity, moment of inertia, and angular velocity, respectively. The density of rock slag particles, The diameter of the rock slag particles, Equivalent viscosity of mud This is the drag coefficient. It is the particle Reynolds number. The equations governing the motion of the rock debris particles comprehensively cover the contact forces, damping forces, and torques between rock debris particles, the interaction between particles and the equipment wall, and the forces exerted by the mud on the particles. They also clarify the relationships between these forces and parameters such as particle mass, velocity, moment of inertia, density, diameter, and the equivalent viscosity and drag coefficient of the mud. This allows for precise capture of the complex motion states of rock debris particles in the flow field, including translation and rotation, and clearly defines the interaction mechanism between the mud and rock debris. This makes the analysis results of rock debris migration behavior in step S4 more scientific and provides a precise targeting basis for parameter adjustment in step S5, ensuring that optimization measures directly address the core causes of rock debris retention and accumulation. Understandably, during simulation calculations, the above calculations are performed for each rock debris particle at each time step, thus achieving comprehensive simulation of the motion.

[0033] Understandably, motion simulation models perform three-dimensional unstructured mesh generation on the excavation chamber, air cushion chamber, and mud pipe network system during simulation calculations and analyses. Tetrahedral meshes are used within the chamber, while a hybrid hexahedral and tetrahedral mesh is used in the pipe network area. Local mesh refinement is applied at the slag inlet, flushing pipe outlet, and bottom of the chamber to ensure the accuracy of flow field gradient and fluid-structure interaction calculations. Figure 2As shown, the numerical calculation of the motion simulation model adopts a two-way CFD-DEM coupling method, using ANSYS Fluent and EDEM software through a CFD-DEM coupling scheme. ANSYS Fluent is responsible for calculating the mud flow field, while EDEM is responsible for solving the motion of the rock cutting particles. The two software programs interact through an application programming interface (API) to achieve data transfer between the mud fluid and the rock cutting particles, completing the two-phase coupled simulation. CFD (Computational Fluid Dynamics) alone cannot accurately characterize the solid motion characteristics of rock cutting particles, such as collision and retention; DEM (Discrete Element Method) alone is insufficient to simulate the fluid dynamics behaviors of mud, such as flow and scouring. Therefore, CFD-DEM coupled simulation is a superior technical choice that balances the fluid and particle phases. The CFD solver uses a pressure-based algorithm, the pressure and velocity coupling uses the SIMPLE algorithm, the time discretization uses a second-order implicit scheme, and the spatial discretization uses a second-order upwind scheme. Fifty DEM substep calculations are performed within each CFD time step to ensure the stability of the particle motion calculation.

[0034] In a specific embodiment of the present invention, the rock slag particle phase is modeled using a multi-size particle group. Different particle sizes are set according to a preset mass ratio or volume fraction ratio to reflect the non-uniformity of rock slag particle size composition under actual construction conditions. The proposed method of modeling the rock slag particle phase using a multi-size particle group and setting different particle sizes according to a preset mass ratio or volume fraction ratio closely matches the real-world scenario of uneven rock slag particle size during actual construction. Compared to the simplified method of modeling with a single particle size in the prior art, this scheme can comprehensively characterize the movement differences of rock slag with different particle sizes. The characteristics of large-size rock slag being easily retained and small-size rock slag being easily carried by the mud are accurately captured, making the simulation results of flow field distribution and rock slag migration behavior more comprehensive. Optimizing the slag discharge parameters based on the analysis results of the multi-size particle group allows for targeted adaptation to rock slag with different particle sizes, avoiding optimization deviations caused by single-size modeling, and further improving the adaptability and efficiency of slag discharge parameters. Specifically, the preset mass ratio or volume fraction ratio can be set according to the actual engineering site environment. Rock slag samples can be taken on-site, and the rock slag particle size can be screened and analyzed using a vibrating screen to obtain the preset mass ratio or volume fraction ratio.

[0035] In a specific embodiment of the present invention, the evaluation indicators for slag discharge performance include at least one of the following: the cumulative amount of slag retained in the chamber (excavation chamber, air cushion chamber), the average movement speed of slag particles, the mass of slag passing through the slag discharge inlet per unit time, and the coverage ratio of slag in the bottom area of ​​the chamber. By clarifying the specific evaluation indicators for slag discharge performance, including the cumulative amount of slag retained, the average movement speed of particles, the mass of slag at the slag discharge inlet per unit time, and the coverage ratio of slag at the bottom of the chamber, quantitative standards are provided for the evaluation judgment in step S5. Transforming slag discharge performance into quantifiable and comparable specific indicators makes the judgment of whether slag discharge parameters meet preset requirements more objective and operational. Simultaneously, multi-dimensional evaluation indicators can comprehensively cover core slag discharge aspects such as slag retention, movement efficiency, and discharge effect, avoiding the one-sidedness caused by single-indicator evaluation, ensuring that the optimized slag discharge parameters can meet construction requirements in multiple key dimensions, and guaranteeing the stability and continuity of shield tunneling. The cumulative retention volume, the average movement speed of rock debris particles, the mass of rock debris passing through the slag discharge inlet per unit time, and the coverage ratio of rock debris in the bottom area of ​​the bin can all be obtained through motion simulation model.

[0036] In a specific embodiment of the present invention, the analysis of flow field distribution characteristics and rock debris migration behavior to obtain the direction for improving slag discharge includes at least: analyzing the low-speed flow region of rock debris within the storage bin, determining that the direction for improving slag discharge is to increase the mud flushing volume in the low-speed flow region, which can be achieved by increasing the flow distribution of the branch pipes corresponding to the low-speed flow region. This clarifies the method for obtaining the direction for improving slag discharge, namely, by analyzing the low-speed flow region of rock debris, focusing the improvement direction on increasing the mud flushing volume in that region, providing a clear and operable logical guide for parameter adjustment in step S5. This solution overcomes the blindness of parameter adjustment in the prior art. By accurately locating the low-speed weak region in the flow field, the adjustment of slag discharge parameters can specifically strengthen the mud carrying and flushing capacity of that region, effectively improving the problem of spatial non-uniformity of the flow field. Compared with parameter trial and error adjustment without a clear direction, this method significantly improves the efficiency of iterative optimization, shortens the parameter optimization cycle, and ensures that the optimization measures directly target the key areas of rock debris retention and accumulation, thereby increasing the improvement in slag discharge effect.

[0037] In a specific embodiment of the present invention, the slag discharge parameters include at least tunneling parameters, flow distribution ratios of each branch pipeline, and operating parameters of the internal circulation pipeline. The slag discharge parameters comprehensively cover the key operational parameters affecting the mud flow field and rock debris migration. Focusing the optimization on the core parameters that play a decisive role in the slag discharge effect makes the initial parameter setting in step S3 and the parameter adjustment in step S5 more targeted. Through precise control of these core parameters, the mud flow velocity, flow field distribution, and rock debris carrying capacity can be directly affected, achieving a highly efficient improvement in slag discharge performance. Tunneling parameters typically include cutterhead rotation speed, cutter penetration depth, etc. Figure 3As shown, the cutterhead rotation speed has a significant impact on slag removal performance and is a core influencing factor. The cutterhead rotation speed directly affects the mud flow field and the migration dynamics of rock debris within the excavation chamber. Excessive rotation speed will cause the mud to form a strong circulation, acting as a barrier to hinder the movement of rock debris towards the air cushion chamber, resulting in repeated stagnation of rock debris within the excavation chamber. If analysis shows that rock debris is constantly circling within the excavation chamber and has difficulty entering the air cushion chamber, the cutterhead rotation speed can be appropriately reduced to weaken the obstructive effect of the circulation, allowing the rock debris to migrate smoothly and solving the problem of rock debris stagnation. The flow distribution in the branch pipelines determines the slag flushing dynamics in critical areas. If the flow is excessively concentrated in non-core areas (such as the top of the chamber), it will lead to insufficient flushing force on critical paths such as the bottom of the chamber and the mud gate. If there is severe rock debris accumulation at the bottom of the excavation chamber, the flow distribution in the top pipeline can be reduced and transferred to the bottom flushing pipeline, enhancing the flushing force of the mud at the bottom of the chamber and pushing the accumulated rock debris along the path, thus solving the problem of slag accumulation at the bottom of the chamber. The operating parameters of the internal circulation pipeline include the jet direction of the internal circulation pipeline. If the jet direction is not aligned with the movement path of the rock debris, it will not only fail to assist in flushing the debris, but may also interfere with the migration of the rock debris. For example, when the rock debris slides at the bottom of the silo, it may lack power and easily get stuck near the mud gate. The jet direction of the circulation pipeline can be adjusted from vertical flushing of the cutter head to oblique downward flushing of the bottom of the silo, which will directly provide thrust for the sliding of the rock debris and improve the problem of path obstruction.

[0038] CFD-DEM coupled simulation analysis was conducted on the slag discharge process under different combinations of operating parameters. By statistically analyzing the distribution of rock debris within the bin, the average particle velocity, and the mass of rock debris passing through the slag discharge inlet per unit time during the simulation, slag discharge performance evaluation indicators were constructed. While keeping the total system circulation flow rate constant, the cutterhead rotation speed, the flow distribution ratio of each branch pipeline, and the operating parameters of the bin's circulation pipeline were selected as design variables. Response surface methodology was used to establish the response relationship between the design variables and the slag discharge performance evaluation indicators, and based on this, the optimal parameter combination for slag discharge performance was determined.

[0039] The optimized parameter combination effectively improves the flow field structure within the tunnel, reduces the retention of rock debris at the bottom of the tunnel, and makes the migration of rock debris towards the discharge inlet more continuous and stable. During actual construction, the tunnel boring machine operates more smoothly, the discharge efficiency is significantly improved, and abnormal operating conditions caused by rock debris retention are significantly reduced.

[0040] It is understandable that the analysis of flow field distribution characteristics and rock debris migration behavior to obtain directions for slag discharge improvement can be achieved in various ways. By analyzing rock debris migration behavior, the movement patterns and dominant migration paths of rock debris within the storage bin can be obtained.

[0041] Flow field distribution characteristics refer to the flow state and spatial distribution of drilling mud within excavation chambers, air cushion chambers, and complex drilling mud pipeline systems, directly determining the mud's ability to carry and flush away rock debris. Specific characteristics of flow field distribution include velocity distribution, pressure distribution, and flow rate distribution. Analyzing these characteristics can reveal directions for improving debris discharge, allowing for corresponding adjustments to discharge parameters. Velocity distribution characteristics, encompassing the magnitude, direction, and distribution of drilling mud velocity at different spatial locations within the chamber, are a core indicator of flow field uniformity. Based on the flow velocity, high-speed and low-speed flow regions can be identified. High-speed flow regions are typically concentrated near the main slurry inlet outlet, the internal circulation pipeline, and the area around the slag discharge inlet. In these regions, the slurry has a strong ability to carry rock debris, making it less prone to retention. Low-speed flow regions are mostly distributed in the bottom corners of the excavation / air cushion chamber, dead corners of pipeline branches, and blind spots on the back of the cutterhead. Velocity distribution reflects the degree of difference in slurry velocity within the same cross-section (e.g., high velocity at the center of the chamber, low velocity at the edges). Excessive gradients indicate poor flow field uniformity, easily leading to rock debris retention in low-speed zones. Velocity distribution allows for precise location of weak areas in the flow field, providing targeted guidance for adjusting the flow distribution in branch pipelines and internal circulation parameters, such as increasing the slurry flushing volume in low-speed zones (a direction for slag discharge improvement). Pressure distribution characteristics represent the magnitude and spatial variation of slurry pressure within the chamber and pipeline system, directly related to slurry flow resistance and slag discharge dynamics. Pressure distribution characteristics include pressure peak regions, pressure trough regions, and pressure stability. Peak pressure areas are concentrated at the main slurry inlet outlet, pipe bends, and narrow passages within the silo. Excessive pressure may lead to accelerated pipe wear or silo sealing risks. Low pressure areas are concentrated near the slag discharge inlet and in low-velocity flow regions. Insufficient pressure may result in insufficient slag carrying power or even negative pressure stagnation. Pressure stability refers to the amplitude of pressure fluctuation over time; excessive fluctuations can easily cause pressure imbalance in the excavation silo. Optimizing slag discharge parameters by adjusting pressure distribution (such as adjusting the operating parameters of the internal circulation pipeline) can balance the pressure within the silo, ensuring sufficient and stable slurry flow power (a direction for slag discharge improvement).

[0042] Flow distribution characteristics include the proportion of slurry flow, flow loss, and flow efficiency in the main slurry inlet pipeline, multi-stage branch flushing pipeline, and in-tank circulation pipeline. Analyzing whether the flow proportion of each branch pipeline matches the flushing requirements of different areas within the tank can provide a direction for future improvements; for example, areas prone to stagnation at the bottom require higher branch flow rates. Flow loss reflects the degree of flow attenuation caused by pipeline bends, valves, and the complex structure within the tank. Flow distribution is a core control method for flow field uniformity; optimizing the flow distribution ratio of each branch pipeline can improve the velocity / pressure distribution within the tank and enhance the flushing capacity of weak areas (a direction for slag discharge improvement).

[0043] Rock cuttings migration behavior includes both trajectory and movement pattern. The trajectory refers to the path of rock cuttings particles within the bin, with the common flow path of most particles being the dominant path. The effective migration path is the path along which particles originate from the cutting zone, are carried smoothly by the mud, and reach the slag inlet. The shorter and smoother the effective migration path, the higher the slag removal efficiency. The path along which particles, unable to continue migrating, settle and accumulate after entering the low-velocity flow zone is the stagnation path (such as particle settling and accumulation in the bottom corners). Generally, the trajectory of large-diameter rock cuttings (easily settling) is closer to the bin bottom, while the trajectory of small-diameter rock cuttings (easily carried by the mud) is closer to the mainstream mud flow direction. The dominant path determines slag removal efficiency, while the stagnation path reflects shortcomings. The path can be optimized by adjusting slag removal parameters, such as increasing the mud velocity on the dominant path to prevent particles from deviating from the effective path (directions for slag removal improvement).

[0044] There is a mutually influential coupling relationship between flow field distribution and rock debris migration. Flow field uniformity determines the rock debris migration path. Uniform velocity / pressure distribution ensures a smooth dominant path for rock debris, resulting in less retention and accumulation. The presence of low-velocity / low-pressure zones in the flow field causes rock debris to deviate from the effective path, leading to retention and accumulation. Rock debris migration also has a reaction effect on the flow field. Rock debris accumulation causes local channel narrowing, which alters the flow distribution and exacerbates flow field inhomogeneity. Collisions of large-diameter rock debris lead to changes in turbulence intensity, increasing mud flow resistance. The flow field distribution can be improved by adjusting the slag discharge parameters (homogenizing velocity / pressure, optimizing flow distribution), thereby guiding rock debris migration behavior (optimizing the path, increasing velocity, reducing retention), ultimately achieving optimal slag discharge performance.

[0045] Analyzing the motion patterns allows for precise identification of the root cause of the problem and determination of directions for improvement in slag removal. Rock debris at the bottom of the storage bin is acted upon by gravity, mud drag, and bin wall friction, primarily sliding along the bottom plane. This slow movement and short migration path lead to accumulation in corners or low-velocity flow areas. Dominant sliding indicates insufficient upward drag from the mud on the rock debris, or that the flow velocity at the bottom is below the critical suspension velocity of the rock debris, preventing it from being carried into the mainstream flow field. If the particles at the bottom primarily slide and remain there, increasing the mud flushing volume in the bottom area can convert some of the sliding rock debris into a suspended state, preventing accumulation (a direction for slag removal improvement).

[0046] The rotation of the cutterhead generates strong disturbances. The surrounding rock debris is suspended and flows with the mud under the drag force of the mud turbulence and the impact force of the cutterhead. The movement speed is fast and the migration path is smooth, which is an ideal form of efficient slag removal. If the rock debris around the cutterhead is still mainly sliding (rather than suspended), it means that the cutterhead speed is insufficient (the disturbance intensity is not strong enough) or the flow distribution of the surrounding branch pipes is insufficient, resulting in low turbulence intensity in the flow field, which cannot support the suspension of rock debris. It is necessary to adjust the cutterhead speed or the flow distribution ratio of the branch pipes near the cutterhead to enhance the disturbance effect around the cutterhead, maintain the suspension state of the rock debris, and improve the carrying efficiency (direction for improvement of slag removal). In low-velocity flow fields (such as dead corners at the bottom of the bin or blind spots in pipeline branches), rock debris shows almost no obvious movement (sliding velocity is less than the preset value, suspension ratio is less than the preset value), and gradually compacts and accumulates. Stagnation indicates that there are dead zones in the flow field in this area, and the mud cannot effectively cover it. It is necessary to adjust the operating parameters of the internal circulation pipeline (such as opening the dedicated flushing branch at the bottom of the bin, increasing the flow rate of local pipelines), or optimize the flow distribution ratio of branch pipelines to guide the mainstream flow field to the vicinity of the stagnant area (direction for improvement of slag discharge). Obtaining the movement pattern of rock debris migration can provide a quantitative basis for the direction of improvement of slag discharge.

[0047] This invention also proposes an optimization system for slag removal parameters of ultra-large diameter slurry shield tunneling machines, comprising: a three-dimensional model construction module for constructing a three-dimensional model including the excavation chamber, air cushion chamber, cutterhead, and slurry pipeline system; a motion simulation model establishment module for establishing a two-phase coupled motion simulation model of the slurry fluid phase and the rock debris particle phase based on the three-dimensional model; an initial setting module for inputting and setting initial slag removal parameters; a simulation calculation module for the motion simulation model to solve the flow process equation of the slurry fluid phase and the motion control equation of the rock debris particle phase according to the slag removal parameters, to obtain the interaction between the slurry fluid phase and the rock debris particle phase, thereby obtaining the flow field distribution characteristics and rock debris migration behavior in the excavation chamber and air cushion chamber; and a judgment and adjustment module for obtaining evaluation indicators of slag removal performance and judging whether the evaluation indicators meet the preset requirements: if yes, the current slag removal parameters are used as the optimized slag removal parameters; if no, the flow field distribution characteristics and rock debris migration behavior are analyzed to obtain the direction of slag removal improvement, and the slag removal parameters are adjusted according to the direction of slag removal improvement. It can adapt to the actual application needs of engineering sites and provide stable and reliable technical support for the construction of ultra-large diameter slurry shield tunnels.

[0048] The present invention also proposes an electronic device, including a processor and a memory, wherein the memory is used to store program code and transmit the program code to the processor; the processor is used to execute a method for optimizing the slag discharge parameters of ultra-large diameter slurry shield tunneling according to the instructions in the program code.

[0049] The present invention also proposes a storage medium storing a computer program, which, when executed by a processor, implements a method for optimizing slag discharge parameters of ultra-large diameter slurry shield tunnels.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing slurry discharge parameters of an ultra-large-diameter slurry shield, characterized in that, The method comprises the following steps: S1, constructing a three-dimensional model comprising an excavation chamber, an air cushion chamber, a cutter head and a slurry pipe network system; S2, based on the three-dimensional model, establishing a two-phase coupled motion simulation model of a slurry fluid phase and a rock residue particle phase, for simulating the slurry flow and rock residue movement process under the action of the slurry pipe network system; S3, setting initial sludge discharge parameters; S4, the motion simulation model solves the flow process equation of the slurry fluid phase and the motion control equation of the rock residue particle phase according to the sludge discharge parameters, obtains the interaction between the slurry fluid phase and the rock residue particle phase, and thus obtains the flow field distribution characteristics and rock residue migration behavior in the excavation chamber and the air cushion chamber; S5, obtaining an evaluation index of sludge discharge performance, and judging whether the evaluation index meets the preset requirements: If yes, the current sludge discharge parameters are used as the optimized sludge discharge parameters; If no, the flow field distribution characteristics and the rock residue migration behavior are analyzed to obtain a sludge discharge improvement direction, the sludge discharge parameters are adjusted according to the sludge discharge improvement direction, and the step S4 is returned.

2. The method according to claim 1, wherein, The flow process equation is: ； ； is the volume fraction of the mud phase, t is time, is the fluid velocity, p is the mud pressure, is the mud density, is the shear stress tensor; is the interaction force between the two phases, is the gravitational acceleration.

3. The method according to claim 1, wherein, The motion control equation of the rock residue particle phase is described as: ； ； ； where ， and are the contact force, damping force and moment between the slag particle and other particles, respectively; ， and are the contact force, damping force and moment between the slag particle and the equipment wall, respectively; is the force applied on the particle by the slurry, and ; ， ， and are the mass, velocity, moment of inertia and angular velocity of the particle, respectively, is the density of the slag particle, is the diameter of the slag particle, is the equivalent viscosity of the slurry, is the drag coefficient, is the Reynolds number of the particle, is the velocity of the slurry.

4. The method according to claim 1, wherein, The rock residue particle phase is modeled by using a plurality of particle groups with different particle sizes, and the different particle sizes are set according to a preset mass ratio or volume fraction ratio.

5. The method according to claim 1, wherein, The evaluation index of the sludge discharge performance includes at least one of the cumulative residence amount of the rock residue in the chamber, the average movement speed of the rock residue particles, the mass of the rock residue passing through the sludge discharge suction inlet per unit time, and the coverage ratio of the rock residue in the chamber bottom area.

6. The method according to claim 1, wherein, The analysis of the flow field distribution characteristics and the rock residue migration behavior to obtain the sludge discharge improvement direction at least includes: Analyzing the low-speed flow area of the rock residue in the chamber to determine that the sludge discharge improvement direction is to improve the slurry scouring amount of the low-speed flow area.

7. The method according to claim 1, wherein, The sludge discharge parameters at least include tunneling parameters, flow distribution ratios of each branch pipe, and operation parameters of the circulating pipe in the chamber.

8. A super-large-diameter slurry shield discharging parameter optimization system, characterized in that, It comprises: A three-dimensional model construction module for constructing a three-dimensional model comprising an excavation chamber, an air cushion chamber, a cutter head and a slurry pipe network system; A motion simulation model establishment module for establishing a two-phase coupled motion simulation model of a slurry fluid phase and a rock residue particle phase based on the three-dimensional model; An initial setting module for inputting and setting initial sludge discharge parameters; A simulation calculation module for the motion simulation model to solve the flow process equation of the slurry fluid phase and the motion control equation of the rock residue particle phase according to the sludge discharge parameters, to obtain the interaction between the slurry fluid phase and the rock residue particle phase, and thus to obtain the flow field distribution characteristics and rock residue migration behavior in the excavation chamber and the air cushion chamber; A judgment and adjustment module for obtaining an evaluation index of sludge discharge performance, and judging whether the evaluation index meets the preset requirements: if yes, the current sludge discharge parameters are used as the optimized sludge discharge parameters; if no, the flow field distribution characteristics and the rock residue migration behavior are analyzed to obtain a sludge discharge improvement direction, and the sludge discharge parameters are adjusted according to the sludge discharge improvement direction.

9. An electronic device, comprising: It comprises a processor and a memory, the memory is used to store program code and transmit the program code to the processor; the processor is used to execute the instructions in the program code to perform the super-large-diameter slurry shield tunnel sludge discharge parameter optimization method in any one of claims 1-7.

10. A storage medium storing a computer program, characterized by The computer program is executed by a processor to realize the large-diameter slurry shield mucking parameter optimization method according to any one of claims 1 to 7.

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