Manufacturing method of high ring rigidity large-diameter integrated molding plastic inspection well

Abstract

The application discloses a manufacturing method of a high-ring-rigidity large-diameter integrated formed plastic inspection well, relates to the technical field of plastic inspection wells, and collects environmental parameters of a service environment of the plastic inspection well, wherein the environmental parameters include geological load parameters, hydrological fluid parameters and climate environment; three-dimensional modeling software is used to establish a three-dimensional parameterized model of the plastic inspection well, and the plastic inspection well model comprises a well shaft, a well base, a flow channel, a branch pipe interface and a bionic honeycomb composite reinforcing structure. The application realizes accurate matching of design parameters and actual working conditions by collecting service environment parameters to construct a mapping matrix, and the product can stably serve under different geological, hydrological and climate conditions, thereby prolonging the service life. The bionic honeycomb composite reinforcing structure is combined with the parameterized design of the bamboo joint-shaped variable cross-section ring-shaped rib, so that the ring rigidity of the product easily reaches SN12 or above, and the anti-settling and anti-lateral pressure performance is improved.

Description

Technical Field

[0001] This invention relates to the field of plastic inspection well technology, and in particular to a method for manufacturing a high-ring stiffness, large-diameter, integrally molded plastic inspection well. Background Technology

[0002] Plastic inspection wells, due to their advantages such as light weight, corrosion resistance, and convenient construction, are gradually replacing traditional brick inspection wells and becoming an important part of municipal infrastructure. However, in the manufacturing of large-diameter (DN≥1000mm) high-ring stiffness products, existing technologies have the following key problems:

[0003] Molding process limitations: Traditional injection molding requires giant equipment and high-cost molds, and is prone to weld lines that can lead to leakage; although ordinary rotational molding has low mold costs, the product rigidity is insufficient and it is difficult to meet the ring stiffness requirements of SN12 and above.

[0004] Structural design defects: The stiffeners are mostly straight with uniform cross-sections, resulting in poor stress dispersion; the flow channel design is not optimized in accordance with actual hydrological parameters, which easily leads to turbulence and sludge deposition, affecting hydraulic performance.

[0005] The challenge of segmented assembly: After large-diameter products are segmented and formed, the joints are often connected by a single bolt or simply sealed, resulting in poor sealing and insufficient structural integrity, which can easily lead to leakage due to geological subsidence.

[0006] Poor environmental adaptability: The design does not fully consider the differences in geological load, hydrological fluid and climate parameters of the service environment. The product is prone to early damage and short service life under complex working conditions.

[0007] Therefore, there is an urgent need for a manufacturing method for large-diameter, high-ring-stiffness plastic inspection wells that takes into account cost, rigidity, sealing performance, and environmental adaptability. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method for manufacturing a high-ring stiffness, large-diameter, integrally molded plastic inspection well. The technical solution adopted is as follows:

[0009] A method for manufacturing high-ring-stiffness, large-diameter, integrally molded plastic inspection wells, including design and manufacturing steps:

[0010] The design steps include:

[0011] Step 1: Collect environmental parameters of the service environment of the plastic inspection well. Environmental parameters include geological load parameters, hydrological fluid parameters, and climate environment.

[0012] Step 2: Use 3D modeling software to create a 3D parametric model of the plastic inspection well. The plastic inspection well model includes the well casing, well seat, flow channel, branch pipe interface and biomimetic honeycomb composite reinforcement structure.

[0013] Step 3: Establish a mapping matrix between environmental parameters and design parameters, and output the stiffener size range, flow channel optimization objective, and topology optimization boundary conditions;

[0014] Step 4: Determine the size and distribution density of the bamboo-shaped variable cross-section annular reinforcement on the inner wall of the wellbore based on environmental parameters;

[0015] Step 5: Based on the hydrological fluid parameters and the flow channel optimization target output by the mapping matrix, CFD technology is used to simulate and optimize the flow channel of the well seat and the branch pipe interface.

[0016] The manufacturing steps include:

[0017] Step 6: Design and manufacture a rotational molding mold based on the three-dimensional parametric model. The mold has a built-in zoned temperature control system and a quick-release insert structure. The product adopts a segmented mold.

[0018] Step 7: Select the main material and pre-treat it by vacuum drying;

[0019] Step 8: The product is simultaneously rotated using multiple sets of segmented molds, and then pre-assembled and verified in the factory after molding.

[0020] Step 9: The segmented product is hoisted into place on a concrete foundation with positioning grooves, and fixed by a composite connection structure of mechanical locking and flange bolts. The joints are treated with a multi-stage sealing process, and after passing the water tightness test, the soil is backfilled in layers.

[0021] Optionally, in step 1, the geological load parameters include soil bearing capacity, backfill compaction degree, groundwater level depth, and lateral earth pressure; the hydrological fluid parameters include fluid velocity, medium pH value, sand content, and annual average flow rate; and the climate environment parameters include extreme temperature, ultraviolet radiation intensity, and number of freeze-thaw cycles.

[0022] Optionally, in step 2, the honeycomb secondary reinforcing ribs and the main reinforcing ribs intertwine to form a closed stress-bearing unit. The biomimetic honeycomb composite reinforcing structure is composed of bamboo-shaped variable cross-section annular main reinforcing ribs on the outside of the well shaft and axial honeycomb secondary reinforcing ribs intertwined.

[0023] Optionally, in step 3, the mapping matrix is ​​constructed using a linear weighted model, with the core formula being:

[0024] ;

[0025] in To output design parameters, the output design parameters include the stiffener size range, flow channel optimization objectives, and parameters corresponding to topology optimization boundary conditions. and These represent the minimum and maximum values ​​of each design parameter; m is the total number of input environment parameters. Let i be the i-th environmental parameter after normalization. The weight of the i-th environmental parameter and satisfying ; These are the constraint correction factors for the design parameters.

[0026] Optionally, the design parameters of the mapping matrix include stiffener height, stiffener spacing, flow channel head loss, sludge deposition rate, and stress constraint value for topology optimization.

[0027] Optionally, step 4 includes the following sub-steps:

[0028] Step 41: Extract the reinforcing rib foundation size range output from the mapping matrix in Step 3, including the height range of the main reinforcing rib foundation. Cross-sectional curvature basic interval and spacing basic interval Simultaneously extract the lateral earth pressure from the geological load parameters. and soil bearing capacity normalized value , and corresponding weights and ;

[0029] Step 42, determine the core dimensions of the bamboo-shaped variable cross-section annular reinforcement using the following formula:

[0030] Maximum height H of the bamboo-shaped variable cross-section annular main stiffener:

[0031] ;

[0032] It is the soil bearing capacity influence coefficient. It is the lateral earth pressure influence coefficient;

[0033] The maximum width B of the cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener:

[0034] ;

[0035] The radius of curvature R of the wavy cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener:

[0036] ;

[0037] Step 43: Determine the distribution density of the bamboo-shaped variable cross-section annular reinforcement using the following formula:

[0038] The axial spacing S between two adjacent bamboo-shaped variable cross-section annular main stiffeners:

[0039] ;

[0040] Distribution density of bamboo-shaped variable cross-section annular main reinforcing ribs .

[0041] Optionally, the specific steps for optimizing the flow channel using CFD technology in step 5 are as follows:

[0042] Step 51: Import the 3D parametric model into the CFD software, refine the structured mesh in the key areas, and use an unstructured mesh in the non-key areas.

[0043] Step 52: Using the design flow rate as the inlet velocity boundary and the outlet as a pressure outlet, set the fluid properties and solid particle parameters in combination with the medium pH value and sand content.

[0044] Step 53: Use the RNGk-ε turbulence model and SIMPLE solver, setting the convergence residuals to be less than or equal to the continuity equation. The momentum and energy equations are less than or equal to ;

[0045] Step 54: Simulate output velocity distribution, pressure loss, and particle trajectory data to analyze turbulence and deposition risk areas;

[0046] Step 55: With the goal of allowing head loss less than or equal to 0.15 mH2O / m and sludge deposition rate less than or equal to 10%, iteratively adjust the elliptical arc transition of the flow channel, the bottom guide ridge, and the trumpet-shaped structure of the branch pipe interface.

[0047] Step 56: When the simulation results meet the target and there are no obvious vortices in the flow channel and the bottom shear stress is greater than or equal to 0.5 Pa, determine the final flow channel model.

[0048] Optionally, in step 7, glass fiber reinforced rotational molding grade high-density polyethylene or cross-linked polyethylene is selected as the main material, compounded with ultraviolet stabilizers, antioxidants and antibacterial agents, and the main material is pretreated by vacuum drying.

[0049] Optionally, the synchronous rotational molding and pre-assembly verification of multiple sets of segmented molds in step 8 are as follows: For products with a diameter of 1 meter or more, 2-4 sets of segmented molds are simultaneously fed into the rotational molding furnace, and the heating temperature, dual-axis rotation speed and cooling rate are uniformly controlled to ensure that the molding parameters of each segment are consistent; after molding, a special positioning fixture is used for factory pre-assembly to check the gap between the joints of each segment, the coaxiality of the connecting holes and the matching degree of the sealing groove size. If the requirements are not met, the mold is finely adjusted or the segment is locally polished to correct the problem until all test items are qualified, ensuring the sealing and structural integrity of the on-site assembly.

[0050] Optionally, in step 10, the multi-seal process includes injecting polyurethane sealant into the main sealing groove, embedding a water-swellable waterstop strip into the secondary groove, and wrapping waterproof tape around the outside of the joint.

[0051] In summary, the present invention has at least one of the following beneficial technical effects: by collecting service environment parameters to construct a mapping matrix, the design parameters and actual working conditions are accurately matched, and the product can be stably used under different geological, hydrological and climatic conditions, thus extending its service life.

[0052] The biomimetic honeycomb composite reinforcement structure, combined with the parametric design of bamboo-shaped variable cross-section ring ribs, enables the product's ring stiffness to easily reach SN12 and above, improving its resistance to settlement and lateral pressure.

[0053] Based on CFD technology and iterative optimization of the flow channel, a head loss of ≤0.15mH2O / m and a sludge deposition rate of ≤10% are achieved, resulting in a significant improvement in hydraulic efficiency compared to traditional structures.

[0054] Synchronous rotational molding of the segmented molds ensures the consistency of the segments. The combination of mechanical locking and flange bolts, along with multiple sealing processes, enables the joints to achieve a water pressure of 0.1MPa for 30 minutes without leakage, significantly improving on-site assembly efficiency.

[0055] The cost of rotational molding molds has been significantly reduced, and the segmented design has reduced transportation and hoisting costs, resulting in a significant reduction in the overall manufacturing cost compared to traditional processes. Attached Figure Description

[0056] Figure 1 This is a schematic flowchart of the manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well of the present invention. Detailed Implementation

[0057] The present invention will be further described in detail below with reference to the accompanying drawings.

[0058] This invention discloses a method for manufacturing a high-ring stiffness, large-diameter, integrated molded plastic inspection well.

[0059] Reference Figure 1 Example 1: A method for manufacturing a high-ring stiffness, large-diameter, integrated molded plastic inspection well, including design steps and manufacturing steps:

[0060] The design steps include:

[0061] Step 1: Collect environmental parameters of the service environment of the plastic inspection well. Environmental parameters include geological load parameters, hydrological fluid parameters, and climate environment.

[0062] Step 2: Use 3D modeling software to create a 3D parametric model of the plastic inspection well. The plastic inspection well model includes the well casing, well seat, flow channel, branch pipe interface and biomimetic honeycomb composite reinforcement structure.

[0063] Step 3: Establish a mapping matrix between environmental parameters and design parameters, and output the stiffener size range, flow channel optimization objective, and topology optimization boundary conditions;

[0064] Step 4: Determine the size and distribution density of the bamboo-shaped variable cross-section annular reinforcement on the inner wall of the wellbore based on environmental parameters;

[0065] Step 5: Based on the hydrological fluid parameters and the flow channel optimization target output by the mapping matrix, CFD technology is used to simulate and optimize the flow channel of the well seat and the branch pipe interface.

[0066] The manufacturing steps include:

[0067] Step 6: Design and manufacture a rotational molding mold based on the three-dimensional parametric model. The mold has a built-in zoned temperature control system and a quick-release insert structure. The product adopts a segmented mold.

[0068] Step 7: Select the main material and pre-treat it by vacuum drying;

[0069] Step 8: The product is simultaneously rotated using multiple sets of segmented molds, and then pre-assembled and verified in the factory after molding.

[0070] Step 9: The segmented product is hoisted into place on a concrete foundation with positioning grooves, and fixed by a composite connection structure of mechanical locking and flange bolts. The joints are treated with a multi-stage sealing process, and after passing the water tightness test, the soil is backfilled in layers.

[0071] In Example 2, step 1, the geological load parameters include soil bearing capacity, backfill compaction degree, groundwater level depth, and lateral earth pressure; the hydrological fluid parameters include fluid velocity, medium pH value, sand content, and annual average flow rate; and the climate environment parameters include extreme temperature, ultraviolet radiation intensity, and number of freeze-thaw cycles.

[0072] In Example 3, in step 2, the honeycomb secondary reinforcing ribs and the main reinforcing ribs intertwine to form a closed stress unit. The biomimetic honeycomb composite reinforcing structure is composed of bamboo-shaped variable cross-section annular main reinforcing ribs on the outside of the well shaft and axial honeycomb secondary reinforcing ribs intertwined.

[0073] By adopting the above technical solutions, the design phase takes environmental adaptation, structural optimization and precise performance matching as the core logic, and realizes the scientific nature of product design through quantitative correlation and simulation iteration.

[0074] Environmental parameter acquisition is a prerequisite for design. By acquiring key data on geological loads, hydrological fluids, and climate, we can provide a basis for actual working conditions in subsequent designs and avoid blind design that leads to product mismatch with the service environment.

[0075] Three-dimensional parametric modeling integrates the various structural components of the inspection well with a biomimetic honeycomb composite reinforcement structure. The bamboo-shaped variable cross-section annular main reinforcing ribs and axial honeycomb secondary reinforcing ribs intertwine to form closed stress-bearing units, utilizing the mechanical advantages of natural structures to improve the overall load-bearing capacity and stress dispersion efficiency of the structure.

[0076] The mapping matrix establishes a quantitative relationship between environmental parameters and design parameters through a linear weighted model, transforming scattered environmental data into clear stiffener size ranges, flow channel optimization objectives, and topology optimization boundary conditions, thereby achieving accurate output of design parameters.

[0077] The determination of the size and distribution density of the reinforcing bars focuses on the key influencing factors in geological loads. The influence of soil bearing capacity and lateral earth pressure is transformed into specific structural parameters through quantitative formulas to ensure that the reinforced structure can specifically resist external loads and meet the requirements of high ring stiffness.

[0078] CFD technology simulation optimization is based on hydrological fluid parameters. By simulating the velocity distribution, pressure changes and particle motion trajectory in the flow channel, it can locate turbulence and deposition risk areas. By iteratively adjusting the flow channel structure, it can minimize hydraulic losses and reduce sludge deposition rate, thus ensuring fluid transport efficiency.

[0079] The manufacturing stage follows the core logic of reliable molding, assembly and sealing, and controllable quality, relying on the advantages of rotational molding technology and structural innovation to achieve efficient manufacturing of large-diameter products.

[0080] The rotational molding-specific segmented mold design is adapted to the manufacturing needs of large-diameter products. The built-in zoned temperature control system can accurately regulate the temperature of each area of ​​the mold, avoiding molding defects in complex structures. The quick-release insert structure improves the versatility of the mold and can be quickly adapted to the production of branch pipe interfaces of different specifications.

[0081] The selection of main materials and vacuum drying pretreatment take into account both the fluidity requirements of rotational molding and the weather resistance and corrosion resistance of the product for long-term service. The pretreatment process removes moisture from the material to avoid defects such as bubbles and pores after molding.

[0082] Multiple sets of segmented molds are synchronously rotated to form segments. By uniformly controlling the heating temperature, rotation speed, and cooling rate, the dimensional accuracy and performance consistency of each segment are ensured. Factory pre-assembly verification checks for matching issues of segment joints, connecting holes, and sealing grooves in advance, laying the foundation for smooth on-site assembly.

[0083] On-site assembly ensures the positioning accuracy of the well body through a concrete foundation with positioning grooves. The mechanical locking and flange bolt composite connection structure combines the advantages of rapid positioning and high-strength fixing, improving the overall structure. Multiple sealing processes form multiple seepage barriers, and water tightness tests verify the sealing effect. Layered backfilling gradually disperses soil pressure and prevents the well body from deforming due to excessive local stress.

[0084] In Example 4, step 3, the mapping matrix is ​​constructed using a linear weighted model, with the core formula being:

[0085] ;

[0086] in To output design parameters, the output design parameters include the stiffener size range, flow channel optimization objectives, and parameters corresponding to topology optimization boundary conditions. and These represent the minimum and maximum values ​​of each design parameter; m is the total number of input environment parameters. Let i be the i-th environmental parameter after normalization. The weight of the i-th environmental parameter and satisfying ; These are the constraint correction factors for the design parameters.

[0087] Example 5: The design parameters of the mapping matrix include the height of the reinforcing ribs, the spacing between the reinforcing ribs, the head loss of the flow channel, the sludge deposition rate, and the stress constraint value for topology optimization.

[0088] By adopting the above technical solution, the mapping matrix is ​​constructed using a linear weighted model, the core of which is to achieve a precise quantitative correlation between environmental parameters and design parameters. Different environmental parameters have varying degrees of impact on product performance, and the weights are used to clarify the importance proportion of each environmental parameter, ensuring that key operating conditions guide the design direction.

[0089] Normalization eliminates the dimensional differences of different environmental parameters, enabling parameters with different units and numerical ranges to be directly superimposed and calculated. This avoids the excessive influence of a single parameter on the design results due to dimensional issues, and ensures the rationality of the calculation logic.

[0090] In the core formula, the minimum and maximum values ​​of the design parameters define the feasible range of the project, preventing the design parameters from exceeding the limits of manufacturing processes or material performance. The weighted summation result reflects the comprehensive influence of environmental parameters, and the design parameters are dynamically adjusted within the feasible range accordingly, so that the design is both suitable for specific working conditions and has engineering feasibility.

[0091] The constraint correction coefficient is adjusted to meet the core performance requirements of the product, ensuring that the design parameters can meet key indicators such as ring stiffness and hydraulic efficiency even under extreme environmental combinations, thus avoiding a disconnect between quantitative calculations and actual performance requirements.

[0092] The selection of design parameters closely addresses the core performance pain points of the product. The height and spacing of the stiffeners directly determine the structural load-bearing capacity and ring stiffness. The flow channel head loss and sludge deposition rate are related to the hydraulic transport efficiency and operation and maintenance costs. The stress constraint value of topology optimization ensures the safety of the structure in long-term service. All dimensions comprehensively cover the three core performance aspects of structure, hydraulics, and durability, achieving a precise correspondence between design parameters and product performance.

[0093] Example 6, step 4 includes the following sub-steps:

[0094] Step 41: Extract the reinforcing rib foundation size range output from the mapping matrix in Step 3, including the height range of the main reinforcing rib foundation. Cross-sectional curvature basic interval and spacing basic interval Simultaneously extract the lateral earth pressure from the geological load parameters. and soil bearing capacity normalized value , and corresponding weights and ;

[0095] Step 42, determine the core dimensions of the bamboo-shaped variable cross-section annular reinforcement using the following formula:

[0096] Maximum height H of the bamboo-shaped variable cross-section annular main stiffener:

[0097] ;

[0098] It is the soil bearing capacity influence coefficient. It is the lateral earth pressure influence coefficient;

[0099] The maximum width B of the cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener:

[0100] ;

[0101] The radius of curvature R of the wavy cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener:

[0102] ;

[0103] Step 43: Determine the distribution density of the bamboo-shaped variable cross-section annular reinforcement using the following formula:

[0104] The axial spacing S between two adjacent bamboo-shaped variable cross-section annular main stiffeners:

[0105] ;

[0106] Distribution density of bamboo-shaped variable cross-section annular main reinforcing ribs .

[0107] By adopting the above technical solution, the core of step 41 is to accurately extract key design basis. The size range of the reinforcing rib foundation output by the mapping matrix defines the feasible boundary of the project, avoiding design parameters from exceeding the limits of manufacturing process or material performance. Lateral earth pressure and soil bearing capacity are the core geological load parameters affecting the stiffness of the well ring. Extracting their normalized values ​​and weights can focus on key working condition factors, ensuring that subsequent calculations respond specifically to the core load requirements.

[0108] Step 42 achieves precise design of core dimensions through quantitative formulas. The calculation of the maximum height of the main reinforcing ribs combines the comprehensive influence of soil bearing capacity and lateral earth pressure. The influence coefficient is used to distinguish the characteristics of the two types of loads, enabling the height design to specifically resist different types of geological pressure. The maximum width of the cross-section is proportional to the height, ensuring the structural stability of the reinforcing ribs themselves and avoiding stress concentration caused by an imbalance in the width-to-height ratio. The calculation of the curvature radius of the wavy cross-section is related to the core load parameters, ensuring that the cross-sectional shape can efficiently disperse stress, which aligns with the mechanical advantages of biomimetic structures.

[0109] Step 43 determines the distribution density by inversely correlated load effects. The formula for the spacing of the main stiffeners ensures that the greater the load influence, the smaller the time interval, and the higher the density, thus achieving a balance between structural strength and material usage. The distribution density is directly derived from the spacing, transforming spatial layout parameters into quantitative indicators, which facilitates dimensional control and quality verification during engineering construction, ensuring that the stiffeners are uniformly distributed and adapted to load requirements.

[0110] The entire process focuses on key geological load parameters, transforming environmental impacts into specific structural parameters through formulaic calculations. This ensures that the size and distribution density of the bamboo-shaped variable cross-section annular reinforcement are both adapted to actual service conditions and have clear engineering operability, ultimately guaranteeing that the well body meets the design annular stiffness requirements.

[0111] Example 7, the specific steps for optimizing the flow channel using CFD technology in step 5 are as follows:

[0112] Step 51: Import the 3D parametric model into the CFD software, refine the structured mesh in the key areas, and use an unstructured mesh in the non-key areas.

[0113] Step 52: Using the design flow rate as the inlet velocity boundary and the outlet as a pressure outlet, set the fluid properties and solid particle parameters in combination with the medium pH value and sand content.

[0114] Step 53: Use the RNGk-ε turbulence model and SIMPLE solver, setting the convergence residuals to be less than or equal to the continuity equation. The momentum and energy equations are less than or equal to ;

[0115] Step 54: Simulate output velocity distribution, pressure loss, and particle trajectory data to analyze turbulence and deposition risk areas;

[0116] Step 55: With the goal of allowing head loss less than or equal to 0.15 mH2O / m and sludge deposition rate less than or equal to 10%, iteratively adjust the elliptical arc transition of the flow channel, the bottom guide ridge, and the trumpet-shaped structure of the branch pipe interface.

[0117] Step 56: When the simulation results meet the target and there are no obvious vortices in the flow channel and the bottom shear stress is greater than or equal to 0.5 Pa, determine the final flow channel model.

[0118] By adopting the above technical solution, the mesh generation logic in step 51 is to balance computational accuracy and efficiency. Critical areas are sensitive to changes in the flow field, and the structured mesh refinement can improve the accuracy of the flow field simulation in these areas. Non-critical areas can use unstructured meshes to simplify calculations and shorten the simulation cycle, ensuring that the overall simulation is both accurate and efficient.

[0119] Step 52 establishes the simulation foundation by recreating the actual working conditions. The inlet velocity boundary and outlet pressure boundary conform to the actual flow state of the fluid. The pH value and sand content of the medium determine the fluid's own properties and the characteristics of solid particles. The authenticity of the parameter settings directly ensures that the simulation results can reflect the actual flow channel operation.

[0120] Step 53 selects a suitable turbulence model and solver. The RNGk-ε turbulence model can accurately capture the complex turbulence morphology in the flow channel, and the SIMPLE solver can stably solve the coupled equations of pressure and velocity. The strict convergence residual setting can filter out calculation errors and ensure the reliability of simulation data.

[0121] Step 54 locates the optimization target by outputting key flow field data. Data such as flow velocity distribution, pressure loss, and particle trajectory intuitively present the channel defects, and clearly define the turbulent region and deposition risk region, providing a precise direction for subsequent structural adjustments and avoiding blind optimization.

[0122] Step 55 is to carry out iterative optimization guided by quantitative performance targets. It allows for clear standards to define the optimization boundary for head loss and sludge deposition rate. Adjustments to the elliptical arc transition of the flow channel, the bottom guide ridge, and the trumpet-shaped structure of the branch pipe interface are all aimed at improving the smoothness of the flow field, reducing local resistance and deposition risk. The iterative process gradually approaches the optimal flow channel morphology.

[0123] Step 56 verifies the overall performance of the flow channel through multiple indicators. The absence of obvious vortices indicates a smooth flow field and low local resistance. The bottom shear stress meets the standard, which can effectively inhibit sludge adhesion. On the basis of meeting the core performance objectives, the stability of the flow channel in the long term and the convenience of operation and maintenance are further guaranteed. The final determined flow channel model achieves the unity of hydraulic performance and practical reliability.

[0124] In Example 8, step 7, glass fiber reinforced rotational molding grade high-density polyethylene or cross-linked polyethylene is selected as the main material, and ultraviolet stabilizer, antioxidant and antibacterial agent are compounded. The main material is pretreated by vacuum drying.

[0125] Example 9, the synchronous rotational molding and pre-assembly verification of multiple sets of segmented molds in step 8 are as follows: For products with a diameter of 1 meter or more, 2-4 sets of segmented molds are simultaneously fed into the rotational molding furnace, and the heating temperature, dual-axis rotation speed and cooling rate are uniformly controlled to ensure that the molding parameters of each segment are consistent; after molding, a special positioning fixture is used for factory pre-assembly to check the gap of each segment joint, the coaxiality of the connecting holes and the matching degree of the sealing groove size. If the requirements are not met, the mold is finely adjusted or the segment is locally polished to correct it until all test items are qualified, ensuring the sealing and structural integrity of the on-site assembly.

[0126] In Example 10, step 10 involves a multi-stage sealing process, including injecting polyurethane sealant into the main sealing groove, embedding a water-swellable waterstop strip into the secondary groove, and wrapping waterproof tape around the outside of the joint.

[0127] By adopting the above technical solution, the main material is selected as glass fiber reinforced rotational molding grade high-density polyethylene or cross-linked polyethylene, the core of which is to adapt to the rotational molding process and product performance requirements. Glass fiber reinforcement can significantly improve the rigidity and mechanical strength of the material, meeting the design requirements of high ring stiffness. Rotational molding grade materials have excellent thermal fluidity, which can ensure uniform adhesion and molding during mold rotation. Cross-linked polyethylene further optimizes the material's creep resistance and heat resistance.

[0128] The combination of UV stabilizers, antioxidants, and antibacterial agents enhances the functionality of inspection wells for outdoor service and fluid transport scenarios. UV stabilizers protect against material aging caused by sunlight radiation, antioxidants slow down material oxidation and degradation, and antibacterial agents inhibit the growth of microorganisms in the fluid, preventing internal wall contamination and corrosion, thus extending product lifespan.

[0129] The main material undergoes vacuum drying pretreatment, the core of which is to eliminate internal moisture. Moisture evaporates during the rotational molding heating process, forming molding defects such as bubbles and pores, which affect the product's sealing performance and structural strength. The pretreatment process ensures the quality of material molding and lays the foundation for subsequent manufacturing processes.

[0130] For large-diameter products, multiple sets of segmented molds are used for simultaneous rotational molding, the core of which is to ensure the consistency of each segment. Uniform control of heating temperature, dual-axis rotation speed and cooling rate ensures that all segments are formed under the same process conditions, ensuring dimensional accuracy, wall thickness uniformity and consistent material properties, and avoiding on-site assembly difficulties caused by differences in segments.

[0131] Factory pre-assembly verification is a crucial step in identifying and addressing compatibility issues in advance. Specialized positioning fixtures simulate on-site assembly conditions, checking joint gaps, coaxiality of connecting holes, and dimensional matching of sealing grooves. This allows for timely detection and correction of deviations through mold fine-tuning or localized grinding of individual panels, preventing substandard panels from entering the construction site.

[0132] The entire process revolves around "assembly reliability." By standardizing the process, the consistency of the petals is ensured. Pre-assembly verification eliminates potential mismatch issues, ultimately ensuring that the joints are tightly sealed and the structural connections are firm during on-site assembly, balancing assembly efficiency and overall performance.

[0133] The multi-layered sealing process employs a layered protection logic, constructing a comprehensive seepage barrier through the complementary effects of different sealing methods. Polyurethane sealant is injected into the main sealing groove, utilizing its excellent adhesion and elasticity to fill the joint gaps and form the primary sealing line, blocking the direct path of fluid penetration.

[0134] The secondary groove is embedded with a water-swellable sealing strip, which has the characteristic of expanding when exposed to water. When there is a slight leakage in the main seal, it can further seal the gap through expansion and compression, forming a secondary protection and improving the sealing redundancy.

[0135] Waterproof tape is wrapped around the outside of the joint as an external auxiliary protection to prevent moisture or impurities in the soil from penetrating the joint area, protect the internal sealing structure from corrosion, and extend the service life of the sealing system. These three methods work in a progressive and synergistic manner to ensure that the inspection well has no risk of leakage during long-term service.

[0136] The technical principles of the present invention are illustrated below using specific embodiments:

[0137] For large-diameter, high-ring-stiffness, integrated molded plastic inspection wells (DN1200mm, with a ring stiffness design requirement ≥SN12) in municipal drainage projects, the following steps should be followed:

[0138] Environmental parameters collected: Geological load parameters: soil bearing capacity 200 kPa, backfill compaction degree 95%, groundwater depth 3 m, lateral earth pressure 100 kPa; hydrological and fluid parameters: design flow velocity 1.2 m / s, medium pH value 7.0, sand content 3.0%, annual average flow rate 800 m³ / d; climatic environmental parameters: extreme minimum temperature -10℃, ultraviolet radiation intensity 1200 kJ / m², freeze-thaw cycles 30 times / year.

[0139] 3D parametric modeling: The model was built using Creo software, including a DN1200mm well shaft, well base, flow channel, DN600mm branch pipe interface, and a biomimetic honeycomb composite reinforcement structure. This structure is formed by interweaving bamboo-shaped variable cross-section annular main reinforcing ribs and axial honeycomb secondary reinforcing ribs to form a closed stress unit.

[0140] Mapping matrix construction: A linear weighted model was adopted, with environmental parameters weighted as follows: soil bearing capacity 0.25, lateral earth pressure 0.20, backfill compaction degree 0.10, design flow velocity 0.15, sand content 0.10, pH value 0.05, extreme minimum temperature 0.08, freeze-thaw cycle 0.05, and ultraviolet radiation intensity 0.02. The output design parameters are: reinforcing rib height 20-50mm, reinforcing rib spacing 150-300mm, channel head loss ≤0.15mH2O / m, sludge deposition rate ≤10%, and topology optimization stress constraint value ≤18MPa.

[0141] Determination of stiffener size and distribution density:

[0142] The normalized values ​​of lateral earth pressure and soil bearing capacity were extracted as 0.67, with corresponding weights of 0.20 and 0.25, respectively.

[0143] Calculate the core dimensions: Maximum height of the main stiffener H = 20 + (50 - 20) × (1.1 × 0.25 × 0.67 + 1.3 × 0.20 × 0.67) = 39 mm; Maximum width of the section B = 0.7 × 39 = 27.3 mm; Radius of curvature of the wavy section R = 50 + (150 - 50) × (0.25 × 0.67 + 0.20 × 0.67) = 90 mm;

[0144] Calculate the distribution density: Axial spacing S = 300 - (300 - 150) × (0.25 × 0.67 + 0.20 × 0.67) = 205 mm; Distribution density ρ = 1 / 0.205 ≈ 4.9 roots / m.

[0145] CFD flow channel optimization:

[0146] Mesh generation: Structured mesh refinement is applied to key areas, with mesh orthogonality of 0.8 and twist of 0.25;

[0147] Boundary and property settings: inlet velocity 1.2m / s, outlet pressure boundary, fluid density 1000kg / m³, viscosity 1.003×10⁻³Pa・s, sand volume fraction 3.0%, particle size 0.1-1.0mm;

[0148] Model and solver: RNG k-ε turbulence model, SIMPLE solver, convergent residual continuity equation ≤10⁻ 4 Momentum and energy equations ≤10⁻ 6 ;

[0149] Optimization and iteration: Adjust the flow channel to a 1 / 4 elliptical arc (major axis to minor axis ratio 1.3), bottom guide rib height 8mm, spacing 60mm, branch pipe interface expansion angle 20°;

[0150] Final results: head loss 0.10 mH2O / m, sludge deposition rate 8%, no obvious vortex in the flow channel, and bottom shear stress 0.6 Pa.

[0151] Mold manufacturing: Two sets of segmented rotational molding molds were designed, using stainless steel composite plate material, with built-in zoned temperature control system (temperature control accuracy ±2℃), and equipped with quick-release insert structure to adapt to DN600mm branch pipe interface.

[0152] Main material preparation: High-density polyethylene with 8% glass fiber content is selected as the main material, compounded with ultraviolet stabilizer, antioxidant and antibacterial agent, and pretreated by vacuum drying at 110℃ for 2 hours.

[0153] Synchronous rotational molding and pre-assembly:

[0154] Molding process: Two sets of segmented molds are simultaneously fed into the rotational molding furnace, with a heating temperature of 220-240℃ (60 min during the melting stage), a main speed of 8 r / min and an auxiliary speed of 3 r / min. During the cooling stage, the furnace is first air-cooled to 150℃ and then water-cooled to below 60℃.

[0155] Pre-assembly verification: Assemble using a dedicated positioning fixture, check that the joint gap is 0.2mm, the coaxiality of the connecting holes is 0.15mm, and the size matching of the sealing groove is qualified, requiring no correction.

[0156] On-site assembly:

[0157] Foundation preparation: Pour concrete foundation with positioning groove;

[0158] Hoisting and fixing: After the segmented pieces are hoisted into place, they are positioned using mechanical locking buckles, and the flange bolts are tightened to a torque of 50 N·m;

[0159] Sealing treatment: Inject polyurethane sealant into the main sealing groove, embed water-swellable waterstop strips into the secondary groove, and wrap waterproof tape around the outside of the joint.

[0160] Acceptance backfilling: Water tightness test at 0.1MPa for 30 minutes with no leakage, well verticality of 0.8mm / m, backfilling soil in layers (each layer 250mm thick, compaction degree 95%).

[0161] Table 1 compares the performance of the product of this invention with that of traditional products:

[0162] Table 1

[0163]

[0164] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a high-ring stiffness, large-diameter, integrated molded plastic inspection well, characterized in that, Includes design and manufacturing steps: The design steps include: Step 1: Collect environmental parameters of the service environment of the plastic inspection well. Environmental parameters include geological load parameters, hydrological fluid parameters, and climate environment. Step 2: Use 3D modeling software to create a 3D parametric model of the plastic inspection well. The plastic inspection well model includes the well casing, well seat, flow channel, branch pipe interface and biomimetic honeycomb composite reinforcement structure. Step 3: Establish a mapping matrix between environmental parameters and design parameters, and output the stiffener size range, flow channel optimization objective, and topology optimization boundary conditions; Step 4: Determine the size and distribution density of the bamboo-shaped variable cross-section annular reinforcement on the inner wall of the wellbore based on environmental parameters; Step 5: Based on the hydrological fluid parameters and the flow channel optimization target output by the mapping matrix, CFD technology is used to simulate and optimize the flow channel of the well seat and the branch pipe interface. The manufacturing steps include: Step 6: Design and manufacture a rotational molding mold based on the three-dimensional parametric model. The mold has a built-in zoned temperature control system and a quick-release insert structure. The product adopts a segmented mold. Step 7: Select the main material and pre-treat it by vacuum drying; Step 8: The product is simultaneously rotated using multiple sets of segmented molds, and then pre-assembled and verified in the factory after molding. Step 9: The segmented product is hoisted into place on a concrete foundation with positioning grooves, and fixed by a composite connection structure of mechanical locking and flange bolts. The joints are treated with a multi-stage sealing process, and after passing the water tightness test, the soil is backfilled in layers. In step 3, the mapping matrix is ​​constructed using a linear weighted model, with the core formula being: ； in To output design parameters, the output design parameters include the stiffener size range, flow channel optimization objectives, and parameters corresponding to topology optimization boundary conditions. and These represent the minimum and maximum values ​​of each design parameter; m is the total number of input environment parameters. Let i be the i-th environmental parameter after normalization. The weight of the i-th environmental parameter and satisfying ; These are the constraint correction factors for the design parameters; Step 4 includes the following sub-steps: Step 41: Extract the reinforcing rib foundation size range output from the mapping matrix in Step 3, including the height range of the main reinforcing rib foundation. Cross-sectional curvature basic interval and spacing basic interval Simultaneously extract the lateral earth pressure from the geological load parameters. and soil bearing capacity normalized value , and corresponding weights and ; Step 42, determine the core dimensions of the bamboo-shaped variable cross-section annular reinforcement using the following formula: Maximum height H of the bamboo-shaped variable cross-section annular main stiffener: ； It is the soil bearing capacity influence coefficient. It is the lateral earth pressure influence coefficient; The maximum width B of the cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener: ； The radius of curvature R of the wavy cross-section of the bamboo-joint-shaped variable cross-section annular main stiffener: ； Step 43: Determine the distribution density of the bamboo-shaped variable cross-section annular reinforcement using the following formula: The axial spacing S between two adjacent bamboo-shaped variable cross-section annular main stiffeners: ； Distribution density of bamboo-shaped variable cross-section annular main reinforcing ribs .

2. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 1, characterized in that: In step 1, the geological load parameters include soil bearing capacity, backfill compaction degree, groundwater level depth, and lateral earth pressure; the hydrological and fluid parameters include fluid velocity, medium pH value, sand content, and annual average flow rate; and the climate and environmental parameters include extreme temperature, ultraviolet radiation intensity, and number of freeze-thaw cycles.

3. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 2, characterized in that: In step 2, the honeycomb secondary reinforcing ribs and the main reinforcing ribs intertwine to form a closed stress unit. The biomimetic honeycomb composite reinforcing structure is composed of bamboo-shaped variable cross-section annular main reinforcing ribs on the outside of the well shaft and axial honeycomb secondary reinforcing ribs intertwined.

4. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 3, characterized in that: The design parameters of the mapping matrix include stiffener height, stiffener spacing, flow channel head loss, sludge deposition rate, and stress constraint values ​​for topology optimization.

5. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 4, characterized in that, The specific steps for optimizing the flow channel using CFD technology in step 5 are as follows: Step 51: Import the 3D parametric model into the CFD software, refine the structured mesh in the key areas, and use an unstructured mesh in the non-key areas. Step 52: Using the design flow rate as the inlet velocity boundary and the outlet as a pressure outlet, set the fluid properties and solid particle parameters in combination with the medium pH value and sand content. Step 53: Use the RNGk-ε turbulence model and SIMPLE solver, setting the convergence residuals to be less than or equal to the continuity equation. The momentum and energy equations are less than or equal to ; Step 54: Simulate output velocity distribution, pressure loss, and particle trajectory data to analyze turbulence and deposition risk areas; Step 55, to allow head loss to be less than or equal to With a sludge deposition rate of less than or equal to 10%, the elliptical arc transition of the flow channel, the bottom guide ridge, and the trumpet-shaped structure of the branch pipe interface were iteratively adjusted. Step 56: When the simulation results meet the target and there are no obvious vortices in the flow channel and the bottom shear stress is greater than or equal to 0.5 Pa, determine the final flow channel model.

6. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 5, characterized in that, In step 7, glass fiber reinforced rotational molding grade high-density polyethylene or cross-linked polyethylene is selected as the main material, and ultraviolet stabilizers, antioxidants and antibacterial agents are compounded. The main material is pretreated by vacuum drying.

7. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 6, characterized in that, Step 8 involves the synchronous rotational molding and pre-assembly verification of multiple segmented molds as follows: For products with a diameter of 1 meter or more, 2-4 sets of segmented molds are simultaneously fed into the rotational molding furnace. The heating temperature, dual-axis rotation speed, and cooling rate are uniformly controlled to ensure that the molding parameters of each segment are consistent. After molding, a special positioning fixture is used for factory pre-assembly to check the gap between the segments, the coaxiality of the connecting holes, and the matching degree of the sealing groove size. If the requirements are not met, the molds are fine-tuned or the segments are locally polished to correct the defects until all test items are qualified, ensuring the sealing performance and structural integrity of the on-site assembly.

8. The manufacturing method of the high-ring stiffness, large-diameter, integrated molded plastic inspection well according to claim 7, characterized in that, In step 10, the multi-seal process includes injecting polyurethane sealant into the main sealing groove, embedding a water-swellable waterstop strip into the secondary groove, and wrapping waterproof tape around the outside of the joint.

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