Large-diameter duct piece independent kiln flow conveying prefabricating method and large-diameter duct piece independent kiln flow conveying prefabricating system

Abstract

The invention relates to the technical field of tunnel engineering prefabricated part production, in particular to a large-diameter duct piece independent kiln assembly line conveying prefabricating method and system. S2, a reinforcement cage and an embedded part are installed; s3, concrete is precisely poured and vibrated; s4, pre-curing and surface treatment; s5, carrying out roller way type flow conveying; s6, hydration heat-driven dynamic maintenance is carried out; and S7, demolding and finished product detection. And S8, mold circulation. According to the large-diameter duct piece prefabricating production line, through technical innovation in multiple aspects of mold, conveying, maintenance, control and the like, the core technical problem in existing large-diameter duct piece prefabricating production is solved, high-precision, high-efficiency, low-energy-consumption and green production of large-diameter duct pieces is achieved, and the large-diameter duct piece prefabricating production line has remarkable technical advantages and wide application prospects and is suitable for large-diameter duct piece prefabricating production. The method can be widely applied to infrastructure construction projects such as shield tunnels, open caisson projects and underground comprehensive pipe galleries.

Description

Technical Field

[0001] This invention relates to the field of precast component production technology for tunnel engineering, specifically to a method and system for precasting large-diameter tunnel segments using an independent kiln with continuous water conveyance. Background Technology

[0002] With the rapid development of infrastructure construction such as urban rail transit, undersea tunnels, and underground integrated pipe corridors, the demand for large-diameter tunnel segments, as the core component of tunnel support, is increasing day by day. Large-diameter tunnel segments typically refer to precast concrete segments with a diameter of ≥3 meters, with a single segment weighing 30-80 tons. They are characterized by large size, heavy weight, high strength requirements (C60-C80), high impermeability grade (P12-P18), and strict dimensional accuracy requirements (roundness error ≤3mm). Their production quality is directly related to the safety, waterproofing, and service life of tunnel projects.

[0003] Currently, the prefabrication of large-diameter tunnel segments mainly adopts either a fixed mold platform + centralized curing kiln mode or a simple assembly line + independent kiln mode. However, the existing technologies have the following prominent problems: Poor mold adaptability and insufficient versatility: Existing segment molds are mostly designed with a fixed diameter. Adjustable molds for large-diameter segments can only achieve small-scale diameter adjustments, and the mold rigidity is insufficient after adjustment, making them prone to deformation during casting and causing the segment dimensional accuracy to exceed the standard. For example, the adjustable segment mold disclosed in patent CN202420219387 can only adjust the width dimension, which cannot meet the diameter adjustment requirements of large-diameter segments; although the modular mold in patent CN202420221383 can adjust the mold size, it is difficult to guarantee the rigidity and sealing performance of the splice when dealing with large-diameter segments of 3 meters or more, which easily leads to grout leakage and deformation problems.

[0004] The conveyor system suffers from insufficient load-bearing capacity and a high risk of damage during transport: Large-diameter segment molds are heavy (≥50 tons), and existing production lines mostly use ordinary roller conveyors or mother-daughter carts for transport. For example, patent CN219788786U uses mother-daughter carts to transport molds into the kiln, but the load-bearing stability of the mother-daughter carts is limited, with a positioning accuracy of only ±5mm. Moreover, vibrations are easily generated during transport, leading to micro-cracks inside the concrete. At the same time, the mother-daughter cart transport efficiency is low, with a single mold taking ≥10 minutes to enter the kiln, which restricts the turnover efficiency of the production line. In addition, the roller material and structural design of existing roller conveyor systems are unable to withstand heavy loads, and long-term use is prone to problems such as roller bending and wear, affecting the stability of the conveyor.

[0005] Inappropriate maintenance processes lead to significant hidden quality risks in tunnel segments: Large-diameter tunnel segments have a large volume, resulting in concentrated release of heat from concrete hydration, and the temperature difference between the inside and outside can easily exceed 30°C, causing temperature stress cracks in the tunnel segments. The existing curing technologies have the following defects: (1) The curing parameters are mostly preset fixed curves. For example, patent CN119635793B uses automated pouring curing, but the curing parameters are based on experience and do not take into account the uneven distribution of hydration heat of large-diameter segments, resulting in asynchronous internal and external curing; (2) The temperature and humidity uniformity of the curing kiln is poor. The temperature and humidity difference between different locations in the centralized curing kiln can reach more than 5°C. For example, the intelligent temperature control system of patent CN108818907A can only control the regional temperature and cannot achieve precise temperature and humidity control between the surface and the interior of the segments; (3) The static stopping time is not set reasonably. Existing technologies mostly use a fixed static stopping time of 1-2 hours, such as patent CN202311474160. The optimal static stopping time is not dynamically calculated in combination with parameters such as concrete mix ratio and cement characteristics, resulting in insufficient early strength development of concrete or excessively long curing cycle.

[0006] High energy consumption and poor energy efficiency: Current large-diameter tunnel segment maintenance mostly uses steam heating or electric heating, which results in high energy consumption, with energy consumption per segment reaching 120-150 kWh / m. 3 Although some patents, such as CN202311474160, have adopted waste heat recovery technology, they can only recover waste heat from a single kiln and have not achieved synergistic utilization of waste heat across kilns. At the same time, the insulation performance of centralized curing kilns is poor, and the heat loss rate can reach 20-30%, which further increases energy consumption.

[0007] Low automation and low production efficiency: In the current production process of large-diameter tunnel segments, processes such as mold debugging, steel cage installation, finishing, and demolding still rely heavily on manual operation. For example, the automated pouring and curing method of patent CN119635793B only automates pouring and finishing. Mold adjustment and demolding still require manual assistance, resulting in low production efficiency. The turnaround time of a single mold is ≥24 hours, and the annual production capacity is less than 3,000 rings. At the same time, manual operation is prone to human error, resulting in a tunnel segment qualification rate of only 95-98% and high rework costs.

[0008] Low efficiency and poor traceability in quality inspection: Existing large-diameter pipe segment size inspection and ultrasonic flaw detection are mostly offline inspections, resulting in low inspection efficiency (1 segment / hour). Furthermore, the inspection data is not linked to production process data, making it impossible to achieve full-process quality traceability. For example, the steam curing kiln in patent CN109676774A does not integrate an online inspection device, so pipe segment quality problems can only be discovered after the segments leave the kiln, affecting production efficiency.

[0009] To address the shortcomings of the existing technologies, this invention proposes a prefabrication method and system for large-diameter tube segments using an independent kiln with continuous flow transmission. Through technological innovations such as mold adaptive adjustment, heavy-duty continuous flow transmission, dynamic curing driven by hydration heat, and intelligent collaborative control, this invention solves the problems of poor mold versatility, large transfer damage, uneven curing, high energy consumption, and low automation in the existing technologies, thereby achieving high-precision, high-efficiency, and low-energy production of large-diameter tube segments. Summary of the Invention

[0010] The purpose of this invention is to provide a method and system for prefabrication of large-diameter tube segments using an independent kiln with continuous water conveyance, in order to solve the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a method for prefabrication of large-diameter segment tubes in an independent kiln with continuous flow transmission, comprising the following steps: S1. Mold self-adaptive adjustment: Move the large-diameter segment mold to the mold clearing station, drive the arc template splicing and assembly through the hydraulic adjustment mechanism according to the target segment diameter, use the laser positioning system to calibrate the roundness, start the reinforcing rib locking device to ensure the mold rigidity, and complete the mold preparation after spraying nano-level release agent. S2. Installation of steel cage and embedded parts: The precast steel cage is accurately placed into the mold cavity using intelligent hoisting equipment, and the waterproof sealing groove and grouting hole embedded parts are installed and fixed by electromagnetic adsorption positioning device. S3. Precision concrete pouring and vibration: C60-C80 high-performance concrete is poured into the mold in layers using a high-low hopper linkage material distribution system, with high-frequency vibration and ultrasonic-assisted vibration device started simultaneously, and vibration time is 30-60s / layer. S4. Pre-curing and surface treatment: After pouring, pre-curing is carried out for 4-6 hours at a normal temperature of 20-25℃ and suitable humidity. When the initial setting strength of the concrete reaches 1.2-2.5MPa, the surface is finished by an automatic troweling machine and covered with a breathable and moisturizing membrane. S5. Roller conveyor system: After pre-curing, the heavy-duty roller conveyor system is started to smoothly convey the mold carrying the tube segments to the inlet of the independent modular curing kiln. The mold is precisely positioned to the center of the kiln body by laser ranging and hydraulic jacking positioning device. S6. Hydration heat-driven dynamic curing: Close the kiln body sealing door and start the multi-dimensional sensor array to monitor data in real time and perform four-stage curing. S7. Demolding and Finished Product Inspection: Demolding is performed first, followed by ultrasonic flaw detection, dimensional accuracy inspection, and impermeability test to inspect the finished product. Qualified pipes undergo subsequent curing, while unqualified products are automatically diverted to the rework station. S8. Mold Cycle: After passing inspection, the mold is cleaned, rust removed, and re-sprayed with release agent. It is then conveyed to the casting station via the return roller conveyor to enter the next production cycle.

[0012] Preferably, the specific implementation method of step S6, hydration heat-driven dynamic curing, is as follows: After closing the kiln's sealing door, the multi-dimensional sensor array is activated. This involves embedding temperature sensors inside the tunnel segments, surface temperature sensors, kiln temperature and humidity sensors, and concrete strength sensors. Based on real-time monitoring data from the multi-dimensional sensor array, a four-stage curing process is executed, as follows: S61. Static curing stage: Maintain a temperature of 20-25℃ and humidity of ≥90%. Based on the tricalcium aluminate content and slump parameters of the concrete, calculate the optimal static curing time of 1.2-2.0h using a mathematical model. S62. Heating stage: Increase the temperature to 45-55℃ at a rate of 10-15℃ / h, monitor the temperature difference inside and outside the tube segment in real time, and when the temperature difference is ≥20℃, reduce the heating rate to 5-8℃ / h and adjust the airflow circulation direction in the kiln simultaneously to ensure that the temperature difference is ≤25℃. S63. Constant Temperature Stage: Maintain temperature at 45-55℃ and humidity at ≥90%. Dynamically adjust the constant temperature time to 8-12 hours based on real-time concrete strength data. Supplement heat energy through a waste heat recovery device, achieving an energy saving rate of ≥30%. S64. Cooling stage: Cool down at a rate of 8-12℃ / h until the temperature difference with the environment is ≤10℃, and simultaneously increase the humidity inside the kiln to above 95% to prevent the surface of the tube segments from losing water and cracking.

[0013] Preferably, the mathematical model in step S6 is a multiple linear regression model: ; in, For optimal stillness time, This refers to the tricalcium aluminate content in cement. The slump of the concrete. For the heating rate, For constant temperature, the regression coefficients are a=0.08-0.12, b=0.005-0.008, c=-0.05-0.03, and d=0.02-0.04.

[0014] Preferably, the implementation methods for step S7, demolding, and finished product inspection are as follows: After curing is completed, the mold is removed from the curing kiln through the roller conveyor system, and the automatic demolding device is started. Hydraulic pushing and vacuum adsorption are used to demold the mold in combination to avoid damage to the tube segments. After demolding, the finished product is inspected by ultrasonic flaw detection, dimensional accuracy detection and impermeability test. Qualified segments are transferred to the water immersion curing area for 7-14 days of subsequent curing, while unqualified products are automatically diverted to the rework station.

[0015] A large-diameter segment independent kiln flow conveyor prefabrication system for implementing the above-described large-diameter segment independent kiln flow conveyor prefabrication method includes: Adjustable large-diameter mold system, heavy-duty continuous conveyor system, independent modular curing kiln system, intelligent collaborative control system and auxiliary production system; Adjustable large-diameter mold system for adapting to the production of segments with diameters of 3-12 meters; Heavy-duty continuous conveyor system for heavy-duty and precise transfer; Independent modular curing kiln system is used for precise temperature and humidity control, and dynamic adjustment of curing parameters to prevent segment cracking due to temperature difference. It also features cross-kiln waste heat recovery for energy saving, modular splicing to adapt to production capacity, and ensures segment strength and impermeability. The intelligent collaborative control system uses PLC controllers and cloud platforms to collect data from multiple sensors, control each system in real time, dynamically adjust and maintain, transmit parameters, and perform remote monitoring. The auxiliary production system employs intelligent hoisting, concrete placement and vibration, surface finishing and demolding, finished product inspection and waste recycling equipment to achieve precise installation of steel cages, dense concrete pouring, and non-destructive demolding of tunnel segments.

[0016] Preferably, the adjustable large-diameter mold system includes a base, an arc-shaped template group, a hydraulic adjustment mechanism, a reinforcing rib locking device, and a laser positioning module; The arc-shaped template assembly is composed of 3-6 arc-shaped steel plates spliced ​​together, with wear-resistant lining plates on the inner side and welded reinforcing ribs on the outer side; the hydraulic adjustment mechanism includes a screw drive unit and a hydraulic locking unit, the screw drive unit adjusts the radius of the arc-shaped template assembly, and the hydraulic locking unit achieves tight fixation at the template splicing points; the laser positioning module includes 3 sets of laser ranging sensors, which monitor the roundness error in real time and feed it back to the control system.

[0017] Preferably, the heavy-duty continuous conveyor system includes a main conveyor roller conveyor, a return roller conveyor, a positioning calibration unit, and a drive unit; Both the main conveyor rollers and the return rollers adopt a modular design, with the rollers made of 40CrNiMo alloy, a spacing of 500-600mm, and a polyurethane anti-slip coating on the surface. The positioning and calibration unit includes a laser rangefinder, a hydraulic jacking device, and a pressure sensor to achieve precise positioning and anti-displacement fixation of the mold. The drive unit adopts a variable frequency motor and chain drive.

[0018] Preferably, the independent modular curing kiln system includes multiple independent kiln bodies, a temperature and humidity control module, an airflow circulation module, and a waste heat recovery module; The kiln body adopts an insulated sandwich panel structure; the temperature and humidity control module includes a heat pump heating device and a steam humidification device, with a temperature control range of 10-80℃ and a humidity control range of 60%-95%RH; the airflow circulation module adopts a symmetrical circulation structure with top air supply and bottom air return, with a wind speed of 0.2-0.3m / s to ensure the uniformity of temperature and humidity inside the kiln; the waste heat recovery module includes a heat exchanger, an energy storage tank, and a cross-kiln conveying pipeline to recover waste heat from the cooling stage for use in the heating stage of other kilns.

[0019] Preferably, the intelligent collaborative control system includes a PLC controller, a multi-dimensional sensor array, a cloud platform data processing module, and an actuator; The multi-dimensional sensor array includes a PT100 temperature sensor embedded inside the tunnel segment, a surface temperature sensor for the tunnel segment, a temperature and humidity sensor inside the kiln, a concrete compressive strength sensor, and a mold positioning sensor; the cloud platform data processing module has a built-in tunnel segment production database and a neural network prediction model, which dynamically generates curing curves based on sensor data and adjusts temperature and humidity parameters and transmission speed in real time; the actuator includes a mold adjustment hydraulic valve, a frequency converter driver for the transmission system, and a temperature and humidity control valve for the curing kiln.

[0020] Preferably, the auxiliary production system includes intelligent hoisting equipment, a high and low hopper linkage material distribution system, an auxiliary vibration device, an automatic finishing machine, a vacuum adsorption demolding device, and a finished product testing device; the rated lifting capacity of the intelligent hoisting equipment is ≥50t; the finished product testing device integrates an ultrasonic flaw detector, a laser dimension measuring instrument, and a permeability testing device.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The adjustable large-diameter mold system of the present invention can achieve precise adjustment of pipe segments with a diameter of 3-12 meters, with small roundness error, and solves the problems of fixed diameter and poor versatility of existing molds. Through the arc-shaped template group + reinforcing rib design and hydraulic locking device, the rigidity of the mold after adjustment is ensured, deformation is avoided during casting, and the dimensional accuracy of the pipe segments is significantly improved.

[0022] The heavy-duty continuous conveying system of this invention adopts high-strength alloy rollers and frequency conversion drive technology. The single roller bearing has a load capacity of ≥8 tons, which can meet the stable conveying of 80-ton large-diameter segment molds. The roller conveyor direct kiln entry design eliminates the traditional mother-daughter car transfer, with high positioning accuracy and a transfer time of less than 3 minutes, which improves efficiency compared with existing technologies. At the same time, it avoids vibration damage during the transfer process and reduces the segment transfer damage rate.

[0023] The hydration heat-driven dynamic curing technology of this invention monitors the temperature difference between the inside and outside of the pipe segment and the concrete strength in real time through a multi-dimensional sensor array. Based on a mathematical model, the curing parameters are dynamically adjusted to control the temperature difference between the inside and outside of the pipe segment to ≤25℃, thereby reducing the cracking rate. The pipe segment strength meets the standard rate and the impermeability grade reaches P15 or above, meeting the high performance requirements of large-diameter pipe segments.

[0024] The independent modular curing kiln system of this invention adopts air source heat pump heating and cross-kiln waste heat recovery technology, which has high waste heat recovery efficiency and reduces energy consumption per unit segment; at the same time, the waste recycling device realizes the recycling of concrete waste, reducing resource waste and environmental pollution.

[0025] This invention employs intelligent collaborative control throughout the entire process, automating operations such as mold debugging, rebar cage installation, pouring and vibration, curing, demolding, and testing, thereby reducing the turnaround time of a single mold; a single production line can produce ≥5000 rings of large-diameter pipe segments annually, while also reducing labor requirements, labor intensity, and human error.

[0026] The intelligent collaborative control system of this invention establishes a data traceability system for the entire process of production, maintenance, and testing. Each segment generates a unique "identity file" that records key data such as concrete mix proportions, maintenance parameters, and test results. This enables full lifecycle traceability from production to installation, effectively mitigating engineering quality risks.

[0027] This invention solves the core technical problems in the existing prefabrication production of large-diameter tunnel segments through technological innovations in molds, conveying, maintenance, and control. It achieves high-precision, high-efficiency, low-energy consumption, and green production of large-diameter tunnel segments, with significant technical advantages and broad application prospects. It can be widely used in infrastructure construction projects such as shield tunnels, caisson projects, and underground integrated pipe corridors. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the system architecture of the present invention; Figure 3 This is a schematic diagram of the system connection of the present invention. Detailed Implementation

[0029] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1-3As shown, a method for prefabrication of large-diameter segment tubes in an independent kiln with continuous flow includes the following steps: S1. Mold self-adaptive adjustment: The large-diameter segment mold is moved to the mold cleaning station. According to the target segment diameter, the initial state of the large-diameter segment mold is the minimum diameter (3 meters). According to the target segment diameter in the production plan (e.g., 8 meters), the intelligent control system sends adjustment instructions to the hydraulic adjustment mechanism. The screw drive unit drives 3-6 arc-shaped templates to expand outward synchronously. The arc-shaped templates are made of 16Mn alloy steel plates with a thickness of 20mm and H-beam reinforcing ribs welded on the outside to ensure that the templates do not deform during the adjustment process. The three sets of laser ranging sensors of the laser positioning module are respectively arranged at the front end, middle end and rear end of the mold to measure the radius and roundness of the arc template in real time, and the measurement data is fed back to the PLC controller in real time. When the laser positioning system detects a roundness error exceeding 2mm, the controller issues a fine-tuning command, which controls the hydraulic drive unit of a single arc-shaped template to achieve precise correction of the roundness error. After adjustment, the hydraulic locking unit is activated, hydraulically tightening the locking bolts at the joint of the arc-shaped template, with a locking force of 50MPa, to ensure the rigidity and sealing of the mold joint; Finally, polytetrafluoroethylene nano-release agent is uniformly sprayed using an automatic spraying device, with the spraying thickness controlled at 30-50μm. High-pressure airless spraying technology is used to ensure that the release agent adhesion reaches level 2 or above, reducing the bonding force between concrete and mold, and reducing the bubble rate on the surface of the pipe segment to below 1%.

[0031] S3. Precise pouring and vibration of concrete: The intelligent hoisting equipment uses a gantry crane with a rated lifting capacity of 50 tons, and is equipped with a laser positioning device and a gravity sensor to monitor the position of the steel cage in real time. Positioning holes are reserved during the prefabrication of the steel cage to precisely match the positioning pins at the bottom of the mold. During the hoisting process, gravity sensors monitor the hoisting force in real time to prevent deformation of the steel cage. Embedded parts include waterproof sealing grooves, grouting hole sleeves, and hoisting hole embedded parts, which are fixed by electromagnetic adsorption positioning devices with an electromagnetic adsorption force ≥5kN to ensure that the embedded parts do not shift during the pouring process. After installation, visual inspection is performed using an industrial camera to confirm that the positional deviation of the steel cage is ≤±10mm and the positional deviation of the embedded parts is ≤±5mm. Once the inspection is passed, the process proceeds to the next step.

[0032] S3. Precise pouring and vibration of concrete: The concrete used is C70 high-performance concrete with a water-cement ratio of 0.32, 20% fly ash and 15% mineral powder added, slump controlled at 80mm, and initial setting time of 7 hours to ensure the workability and strength development of the concrete. The high and low hopper linkage material distribution system includes a high-level storage hopper (5m³). 3 ) and low-level feeding hopper (1.5m³) 3 The high-level hopper transports concrete to the low-level placing hopper via a screw conveyor. The low-level placing hopper moves along the length of the mold to place the concrete at a speed of 0.5 m / s. 3 / min; A layered pouring method is adopted, with each layer being 250mm thick. The pouring sequence is continuous from one end of the mold to the other to avoid construction joints. The compaction process employs a combination of high-frequency vibration and ultrasonic-assisted compaction technology. The high-frequency vibration device is installed on the outside of the mold, with a vibration frequency of 60Hz and a vibration acceleration of 12g, ensuring the compaction of concrete aggregate. The ultrasonic-assisted compaction device is installed below the placing hopper, with a frequency of 30kHz and a power of 600W, effectively eliminating air bubbles inside the concrete. After each layer is poured, the vibration time is controlled at 45 seconds. The concrete density sensor monitors the compaction in real time. When the compaction reaches 99%, the vibration is automatically stopped to avoid over-vibration that could cause aggregate segregation.

[0033] S4. Pre-curing and surface treatment: After the casting is completed, the mold remains stationary and enters the pre-curing area. The ambient temperature in the pre-curing area is controlled at 22℃ and the relative humidity is 88%. The humidity is kept stable by steam spraying. The pre-curing time is 4-6 hours, depending on the initial setting strength of the concrete. When the concrete strength reaches 1.8MPa (detected by the pre-embedded sensor), the automatic finishing machine is started. The automatic smearing machine adopts a double smearing disc structure. The smearing disc is made of polyurethane and rotates at 40 r / min. The smearing disc can be adaptively adjusted along the arc surface of the tube sheet, and the smearing flatness error is ≤2 mm / m. After applying the face cream, immediately cover with a breathable and moisturizing film. The breathability of the moisturizing film should be controlled at 50g / (m²). 2 • 24h) This ensures that the concrete has the necessary moisture for hydration and also removes the carbon dioxide produced during hydration, thus preventing surface sanding.

[0034] S5, Roller conveyor system: The heavy-duty roller conveyor adopts a modular design. Each section of the roller conveyor is 3 meters long and consists of 6 roller shafts. The roller shafts are made of 40CrNiMo alloy, which has been quenched and tempered to achieve a hardness of HRC35-40. The diameter is 120mm, the roller shaft spacing is 550mm, and the single roller bearing has a load capacity of 8 tons, which meets the load-bearing requirements of an 80-ton mold. The roller surface is coated with a 5mm thick polyurethane anti-slip coating with a friction coefficient ≥0.8 to prevent slippage during mold conveying. The drive unit uses a variable frequency motor (15kW) + chain drive, with a transmission efficiency of 96%. The transmission speed is infinitely adjustable via frequency conversion control, ranging from 0.5-1m / min. Soft start is used for start-stop, with an acceleration ≤0.1m / s². 2 To avoid impact loads; When the mold is transferred to the independent kiln inlet, the positioning calibration unit is activated. The laser rangefinder measures the deviation between the mold and the center of the kiln body. The hydraulic jacking device (thrust ≥10kN) accurately pushes the mold to the center of the kiln body with a positioning accuracy of ±0.5mm. After positioning is completed, the kiln body sealing door automatically closes.

[0035] S6. Hydration heat-driven dynamic curing: Sensor arrangement: Three PT100 temperature sensors are pre-embedded inside the tube segment (located at the center of the tube segment, at 1 / 2 thickness, and 50mm inside the surface, respectively), two temperature sensors are arranged on the surface of the tube segment, and four temperature and humidity sensors are arranged inside the kiln (top, bottom, left and right sides). The concrete strength sensor adopts a fiber optic grating sensor and is pre-embedded in the key stress parts of the tube segment. S61. Static Stoppage Stage: After closing the kiln's sealed door, the system first enters the static stoppage stage. The intelligent control system, based on the tricalcium aluminate content of the cement, the concrete slump, the preset heating rate, and the constant temperature, uses a multiple linear regression model... Calculate the optimal resting time, temperature maintenance during the resting phase, and humidity; Among them, the multiple linear regression model: ; in, For optimal stillness time, This refers to the tricalcium aluminate content in cement. The slump of the concrete. For the heating rate, For constant temperature, the regression coefficients are a = 0.08 - 0.12, b = 0.005 - 0.008, c = -0.05 - 0.03, and d = 0.02 - 0.04. S62. Heating Phase: After the static shutdown ends, heating begins with an initial heating rate of 12℃ / h. The temperature difference between the inside and outside of the tube segment is monitored in real time (the difference between the internal center sensor and the surface sensor). When the temperature difference reaches 20℃, the control system automatically reduces the heating rate to 6℃ / h and adjusts the airflow circulation direction from "top air supply" to "side air supply" to accelerate heat dissipation from the tube segment surface and ensure that the temperature difference does not exceed 25℃. During the heating process, heat energy is provided by a heat pump heating device with a COP value of 3.8, resulting in significant energy savings. S63. Constant Temperature Stage: After the temperature rises to 50℃, the constant temperature stage begins, with humidity maintained at 92%. Fiber optic grating sensors monitor the concrete strength in real time. When the strength reaches 30MPa (approximately 10 hours), the control system begins to prepare for cooling. The heat energy in the constant temperature stage comes from the waste heat recovery device, which recovers waste heat from the cooling stage of other kilns. The heat energy is transferred to the energy storage tank through a plate heat exchanger (heat exchange efficiency 88%), and then transported to the kiln in the heating stage, realizing cross-kiln waste heat utilization. S64. Cooling stage: Cooling is carried out at a rate of 10℃ / h. When the temperature inside the kiln drops to 30℃, the cooling rate is reduced to 8℃ / h. At the same time, the humidity inside the kiln is increased to 95% to prevent the surface of the tube segments from losing water too quickly and causing shrinkage cracks. The waste heat generated during the cooling process is collected by the waste heat recovery module and stored in the energy storage tank for use by other kilns.

[0036] S7. Demolding and Finished Product Inspection: After curing is completed (the temperature inside the kiln drops to 25℃, and the temperature difference with the environment is ≤5℃), the kiln's sealed door is opened, and the roller conveyor system moves the mold out of the curing kiln and sends it to the demolding station. The automatic demolding device is activated. First, the hydraulic jacking device pushes the tube sheet from the inside of the mold (jacking force 100kN, 6 jacking points evenly distributed), while simultaneously the vacuum adsorption device adsorbs the tube sheet from the outside (adsorption pressure -0.07MPa, adsorption area 0.6m²). 2 The synergistic effect allows the segments to separate from the mold, preventing damage to the edges and corners of the segments; After demolding, the tube segments are conveyed to the finished product inspection station via roller conveyor. The inspection process is as follows: The laser dimension measuring instrument measures diameter (8000±2mm), roundness (≤2mm), and thickness (300±1mm), with a measurement time of 3 minutes per piece. Ultrasonic flaw detectors detect internal defects with a detection depth of 300mm, a sensitivity of ≥40dB, and no internal defects ≥3mm. The impermeability test was conducted using a permeability meter, with a water pressure of 1.5 MPa applied and maintained for 30 minutes without leakage. Qualified segments are transported to the immersion curing area via intelligent hoisting equipment for 10 days of subsequent curing at a water temperature of 22℃; unqualified segments are automatically diverted to the rework station to analyze the causes of defects and make repairs; all test data are uploaded to the cloud platform to form a segment "identity file" and realize quality traceability.

[0037] S8, Mold Circulation: Use a high-pressure water gun (20MPa) to clean the inside of the mold and remove residual concrete; The steel wire brush roller is subjected to rust removal treatment, and the surface roughness of the mold Ra after rust removal is ≤6.3μm; The automatic spraying device re-sprays the release agent and, after cleaning the mold, the mold is transferred to the casting station to enter the next production cycle. The turnaround time for a single mold is 16 hours.

[0038] like Figure 2-3 As shown, a large-diameter segment independent kiln flow conveyor prefabrication system includes: Adjustable large-diameter mold system, heavy-duty continuous conveyor system, independent modular curing kiln system, intelligent collaborative control system, and auxiliary production system.

[0039] Adjustable large-diameter mold system, including: Base: The base adopts a box-type steel structure, made of Q355B steel with a thickness of 30mm. The bottom is equipped with a leveling device with a leveling accuracy of ±0.2mm / m to ensure that the mold is installed horizontally. The base is 6-8 meters long and 4-5 meters wide to meet the production needs of large-diameter tube segments of different lengths. The curved formwork assembly consists of four curved steel plates spliced ​​together. Each curved steel plate has a central angle of 90°, is made of 16Mn steel, and is 20mm thick. The inner side is welded with a 3mm thick wear-resistant lining plate, and the outer side is welded with I-beam reinforcing ribs (model I20a). The reinforcing ribs are spaced 500mm apart to ensure the rigidity of the formwork at its maximum diameter (12 meters), with bending deformation ≤1mm. The splice of the curved formwork is equipped with a V-shaped sealing groove and an internal fluororubber sealing strip with a compression of 6mm to prevent grout leakage during pouring. Hydraulic adjustment mechanism: includes a lead screw drive unit and a hydraulic locking unit. The lead screw drive unit uses a ball screw (20mm lead, C7 accuracy grade), driven by a servo motor, with an adjustment speed of 5mm / s and an adjustment range of 3000-12000mm. The hydraulic locking unit uses a double-acting hydraulic cylinder with a cylinder diameter of 80mm, a stroke of 50mm, and a working pressure of 50MPa to ensure the locking force at the splicing point. Laser positioning module: It adopts 3 sets of laser range sensors (model KEYENCELK-G5000), with a measurement range of 0.1-10m and an accuracy of ±0.01mm. They are respectively arranged at the front, middle and rear of the mold to monitor the radius and roundness of the arc template in real time. The data sampling frequency is 10Hz and the data is fed back to the PLC controller for closed-loop control.

[0040] Heavy-duty continuous conveyor system, including: Main conveyor roller conveyor: 60 meters in total length, divided into 6 sections, each 10 meters long, with a modular design for easy installation and maintenance; the rollers are made of 40CrNiMo material, heat-treated (hardness HRC35-40), with a diameter of 120mm, a length of 4.5 meters, and a roller spacing of 550mm. Each section of the roller conveyor consists of 6 rollers, with a single roller bearing capacity of 8 tons, and the entire section of the roller conveyor has a load capacity of ≥48 tons, meeting the conveying requirements of an 80-ton mold; Return roller conveyor: Arranged parallel to the main conveyor roller conveyor, with a total length of 50 meters, and has the same structure as the main conveyor roller conveyor, it is used for the circulation and return of molds; Positioning and calibration unit: includes 2 sets of laser rangefinders (model SICKDME5000), 4 hydraulic jacking devices and 4 pressure sensors. The laser rangefinders measure the deviation between the mold and the center of the kiln body. The hydraulic jacking devices (cylinder diameter 63mm, stroke 100mm, thrust 10kN) push the mold to the center position. The pressure sensors monitor the jacking force to ensure stable positioning. Drive unit: It adopts a variable frequency motor (model YVP225M-4, power 15kW, speed 1480r / min) + chain drive, chain model 16A-2×60, transmission ratio 1:10, to achieve a roller speed of 0.5-1r / min, corresponding to a mold conveying speed of 0.5-1m / min; the roller ends adopt self-aligning roller bearings (model 22220CA / W33), with a fit grade of P6, to reduce eccentric wear during roller operation; Protective devices: Anti-collision guardrails (500mm high, Q235B material) are installed on both sides of the roller conveyor, and a water collection tank is installed under the roller shaft to collect wastewater generated during the casting and mold cleaning process to avoid environmental pollution.

[0041] Independent modular curing kiln system, including: Independent kiln body: Each kiln body measures 7 meters long × 4.5 meters wide × 5.5 meters high. It employs an insulated sandwich panel structure, with an outer panel of 0.8mm thick color steel plate, an inner panel of 0.6mm thick stainless steel plate, and a core material of 100mm thick polyurethane insulation board, achieving an insulation coefficient of 0.028 W / (m·K). The kiln body is modularly assembled, and a single production line can be configured with 8 independent kiln bodies, with an annual production capacity of 5000 ring segments. The kiln body sealing door uses an inflatable sealing structure with a sealing pressure of 0.4MPa and an air leakage rate ≤3%. Temperature and humidity control module: includes an air source heat pump heating unit (model KFXRS-36II, heating capacity 36kW, COP value 3.8) and a steam humidification unit (model CY-15, humidification capacity 15kg / h); temperature control range 10-80℃, accuracy ±0.5℃, controlled by proportional-integral-derivative (PID) algorithm to start / stop the heat pump and control its output power; humidity control range 60%-95%RH, accuracy ±5%, achieved by controlling the spray volume of the steam humidification unit. Airflow circulation module: Adopts a symmetrical circulation structure with top air supply and bottom air return, fan model 4-72-11, air volume 15000m³ / h 3 / h, air pressure 1200Pa; the kiln is equipped with 4 guide plates, the angle of which can be adjusted according to the diameter of the tube segment (0-30°) to ensure that the temperature and humidity difference between the outer arc surface and the inner arc surface of the tube segment is ≤2℃; Waste heat recovery module: includes a plate heat exchanger (model BR0.3-1.0, heat exchange area 3m²). 2 Heat exchange efficiency 88%), energy storage tank (8m³ / s) 3 The insulation layer is 120mm thick and made of 304 stainless steel. The cross-kiln conveying pipeline is 50mm in diameter and has an insulation layer thickness of 50mm. The waste heat recovery module monitors the temperature status of each kiln through temperature sensors. When a kiln enters the cooling stage and the temperature is ≥40℃, the waste heat recovery pump is started. The hot and humid air in the kiln is heated by exchanging heat through a plate heat exchanger to heat the water in the energy storage tank. The hot water is then transported to the kiln in the heating stage. Through heat pump auxiliary heating, cross-kiln waste heat utilization is realized, with an energy saving rate of ≥35%.

[0042] Intelligent collaborative control system, including: PLC controller: adopts Siemens S7-1500 series PLC, equipped with 16 analog input modules, 16 digital input modules, and 16 digital output modules, responsible for real-time acquisition of sensor data and control of actuator actions; communication between the PLC and each module adopts Profinet bus, communication rate 100Mbps, response time ≤0.5s; Multi-dimensional sensor array: including PT100 temperature sensor embedded inside the tunnel segment (accuracy ±0.1℃), surface temperature sensor of the tunnel segment (accuracy ±0.2℃), temperature and humidity sensor inside the kiln (model SHT30, temperature accuracy ±0.2℃, humidity accuracy ±2%RH), concrete compressive strength sensor (fiber optic grating sensor, accuracy ±0.5MPa), mold positioning sensor (laser rangefinder sensor, accuracy ±0.01mm), and concrete density sensor (model HCD-200, accuracy ±1%); sensor data acquisition frequency is 1 time / minute, and data is uploaded to the cloud platform via wireless transmission module (LoRa gateway, communication distance ≥1km); Cloud platform data processing module: It adopts Alibaba Cloud server and has a built-in segment production database (storing more than 5,000 sets of production data of different diameters and different concrete mix proportions) and neural network prediction model (based on BP neural network, with sensor data as input parameters and optimal curing curve as output parameters). The cloud platform has functions such as data storage, curve generation, parameter adjustment, fault alarm, and report generation, which can realize real-time monitoring of the production process and historical data traceability. The actuators include a mold regulating hydraulic valve (model 4WE6Y6X / EG24N9K4, response time ≤0.1s), a transmission system frequency converter (model MM440, power 15kW), a curing kiln temperature and humidity control valve (electric ball valve, model Q941F-16C, diameter DN50), an automatic finishing machine driver (servo driver, model S120), and a demolding device hydraulic pump (model PV2R12, displacement 12mL / r). The actuators operate precisely according to the instructions of the PLC controller, ensuring the stability of the production process. Remote monitoring terminal: Supports access via mobile APP (Android and iOS systems) and computer client. Managers can view production status (such as mold adjustment progress, casting status, curing parameters, and test results), equipment operating parameters (such as motor current, hydraulic pressure, and sensor data), and production reports (daily output, pass rate, and energy consumption data) in real time. They can also remotely issue production instructions to achieve remote operation and maintenance.

[0043] The auxiliary production system includes: Intelligent hoisting equipment: A gantry crane (model MG50 / 10-22.5A3, rated lifting capacity 50 tons, span 22.5 meters, lifting height 10 meters) is used, equipped with a laser positioning device (accuracy ±10mm) and a gravity sensor (accuracy ±0.1 tons) to achieve precise hoisting of steel cages and tunnel segments; High and low hopper linked material distribution system: High-level storage hopper with a volume of 5m³ 3 Equipped with a screw conveyor (model LSY315, conveying capacity 50m³). 3 / h); Low-level fabric hopper volume 1.5m³ 3 Equipped with a moving guide rail (8 meters in length) and a fabric inlet (150 mm in diameter), it can move the fabric along the length of the mold, with a fabric uniformity error of ≤5%. Auxiliary vibration devices: High-frequency vibration devices (model ZW-15, power 15kW, frequency 60Hz, vibration acceleration 12g) are installed on the outside of the mold, with 2 units for each arc-shaped template; Ultrasonic auxiliary vibration devices (model CSB-30, power 600W, frequency 30kHz) are installed below the low-level material hopper, with 4 units evenly distributed. Automatic smearing machine: It adopts a double smearing disc structure with a smearing disc diameter of 500mm and made of polyurethane. The rotation speed is 0-60r / min (infinitely adjustable). The smearing disc support can move along the arc-shaped guide rail to adapt to the arc-shaped surface of the tube sheet. The smearing flatness error is ≤2mm / m. Vacuum adsorption demolding device: includes 6 hydraulic push cylinders (model HSG80 / 55-50, thrust 100kN) and 4 vacuum adsorption plates (diameter 800mm, adsorption area 0.6m²). 2(Adsorption pressure -0.07MPa), hydraulic jacking cylinders are evenly distributed inside the mold, and vacuum adsorption disks are evenly distributed outside the tube, working together to achieve demolding; Finished product testing equipment: integrated laser dimension measuring instrument (model LeicaAT960, measuring range 3-12 meters, accuracy ±0.1mm / m), ultrasonic flaw detector (model USM35X, detection depth 300mm, sensitivity ≥40dB), and impermeability testing device (model HP-4.0, maximum test pressure 4.0MPa), with a testing efficiency of 2 pieces / hour; Waste recycling equipment includes a waste collection tank, a crusher (model PE250×400, crushing particle size ≤20mm), and a screening machine (model YK1530, screening efficiency ≥90%). It collects concrete waste generated during the pouring and formwork cleaning process, and after crushing and screening, it is used as recycled aggregate for concrete mixing, with a recycling rate of ≥30%. Specific Implementation Example 1: This embodiment focuses on the prefabrication of shield tunnel segments with a diameter of 8 meters, a thickness of 300 mm, and a width of 2 meters, using the method and system of this invention. The specific implementation process is as follows: Mold self-adaptive adjustment: The target tube segment has a diameter of 8 meters. The intelligent control system sends adjustment commands to the hydraulic adjustment mechanism. The screw drive unit drives the four arc-shaped templates to expand synchronously. The laser positioning module monitors in real time. When the roundness error reaches 1.8mm, the controller issues a fine-tuning command. After correction, the roundness error is 1.2mm. The hydraulic locking unit is activated, and the locking force reaches 50MPa. Polytetrafluoroethylene release agent is automatically sprayed with a thickness of 40μm and an adhesion level of 2.

[0045] Installation of steel reinforcement cage and embedded parts: The steel reinforcement cage weighs 8 tons and is accurately placed into the mold using intelligent hoisting equipment. The laser positioning instrument shows a positional deviation of 8mm. The embedded parts such as waterproof sealing groove and grouting hole sleeve are installed and fixed by electromagnetic adsorption device. Visual inspection shows that the positional deviation of the embedded parts is 3mm, which is qualified.

[0046] Precise concrete pouring and vibration: C70 high-performance concrete is used with a water-cement ratio of 0.32 and a slump of 80mm; a high and low hopper linkage material distribution system is used for layered pouring, with each layer being 250mm thick and the pouring time being 40 minutes; high-frequency vibration + ultrasonic-assisted vibration is used for each layer, with each layer vibrating for 45 seconds, and the density sensor shows a density of 99.2%.

[0047] Pre-curing and surface treatment: The temperature in the pre-curing area is 22℃, the humidity is 88%, the pre-curing time is 5 hours, and the concrete strength reaches 1.8MPa; the automatic troweling machine is started, and the surface flatness error is 1.5mm / m; a breathable and moisturizing membrane is covered.

[0048] Roller conveyor: The heavy-duty roller conveyor transports the mold to the independent kiln inlet at a speed of 0.8m / min. The positioning and calibration unit accurately positions the mold to the center of the kiln body with a positioning deviation of 0.3mm, and the kiln body sealing door is closed.

[0049] Hydration heat-driven dynamic curing: Static curing phase: The optimal static curing time was calculated to be 1.5 hours based on a multiple linear regression model, with a temperature of 22℃ and humidity of 90%. Heating stage: The initial heating rate is 12℃ / h. When the temperature difference between the inside and outside of the tube reaches 20℃, the heating rate is reduced to 6℃ / h. Finally, the temperature is raised to 50℃, which takes 3.5 hours. Constant temperature stage: Maintain a temperature of 50℃ and humidity of 92% for 10 hours, and the concrete strength will reach 32MPa. Cooling stage: The temperature is reduced to 30℃ at a rate of 10℃ / h, and then reduced to 25℃ at a rate of 8℃ / h, with a humidity of 95%, taking 3 hours; the waste heat recovery module collects 120kWh of waste heat for use in other kilns.

[0050] Demolding and finished product inspection: The mold is removed from the curing kiln, and the automatic demolding device works together to demold the segments smoothly without damage; the finished product inspection shows: diameter 8000.8mm, roundness 1.5mm, thickness 299.5mm, ultrasonic flaw detection shows no internal defects, and the anti-permeability test shows no leakage under 1.5MPa pressure for 30 minutes, which is qualified; the test data is uploaded to the cloud platform to form the segment's "identity file".

[0051] Mold cycle: After cleaning, rust removal and spraying of release agent, the mold is conveyed to the casting station to enter the next round of production. The turnaround time for a single mold is 16 hours.

[0052] The 8-meter diameter pipe segments produced in this embodiment meet the design requirements in terms of dimensional accuracy, strength, and impermeability. The production efficiency is 33% higher than that of the existing technology, and the energy consumption is reduced by 35%, achieving significant technical and economic benefits. Specific Implementation Example 2: This embodiment focuses on the prefabrication of caisson segments with a diameter of 10 meters, a thickness of 350 mm, and a width of 2.4 meters, using the method and system of this invention. The core parameters are adjusted as follows: Mold adjustment: The arc template group is expanded to a diameter of 10 meters. After laser positioning and calibration, the roundness error is 1.8 mm, and the hydraulic locking force is 50 MPa. Concrete: C80 high-performance concrete, water-cement ratio 0.30, slump 70mm, initial setting time 8 hours; Maintenance parameters: static curing time 1.8h, heating rate 10℃ / h, constant temperature 55℃, constant temperature time 12h, cooling rate 8℃ / h; Test results: Diameter 10001.2mm, roundness 2.0mm, thickness 349.8mm, concrete strength 35MPa, impermeability grade P18, pass rate 99.6%.

[0054] This embodiment verifies the adaptability of the system of the present invention to larger diameter segments, the stable production process, and the excellent product quality, further demonstrating the technical advancement and practicality of the present invention.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for prefabrication of large-diameter segment tubes using an independent kiln with continuous flow transmission, characterized in that, Includes the following steps: S1. Mold self-adaptive adjustment: Move the large-diameter segment mold to the mold clearing station, drive the arc template splicing and assembly through the hydraulic adjustment mechanism according to the target segment diameter, use the laser positioning system to calibrate the roundness, start the reinforcing rib locking device to ensure the mold rigidity, and complete the mold preparation after spraying nano-level release agent. S2. Installation of steel cage and embedded parts: The precast steel cage is accurately placed into the mold cavity using intelligent hoisting equipment, and the waterproof sealing groove and grouting hole embedded parts are installed and fixed by electromagnetic adsorption positioning device. S3. Precision concrete pouring and vibration: C60-C80 high-performance concrete is poured into the mold in layers using a high-low hopper linkage material distribution system, with high-frequency vibration and ultrasonic-assisted vibration device started simultaneously, and vibration time is 30-60s / layer. S4. Pre-curing and surface treatment: After pouring, pre-curing is carried out for 4-6 hours at a normal temperature of 20-25℃ and suitable humidity. When the initial setting strength of the concrete reaches 1.2-2.5MPa, the surface is finished by an automatic troweling machine and covered with a breathable and moisturizing membrane. S5. Roller conveyor system: After pre-curing, the heavy-duty roller conveyor system is started to smoothly convey the mold carrying the tube segments to the inlet of the independent modular curing kiln. The mold is precisely positioned to the center of the kiln body by laser ranging and hydraulic jacking positioning device. S6. Hydration heat-driven dynamic curing: Close the kiln body sealing door and start the multi-dimensional sensor array to monitor data in real time and perform four-stage curing. S7. Demolding and Finished Product Inspection: Demolding is performed first, followed by ultrasonic flaw detection, dimensional accuracy inspection, and impermeability test to inspect the finished product. Qualified segments are then cured, while unqualified segments are automatically diverted to the rework station. S8. Mold Cycle: After passing inspection, the mold is cleaned, rust removed, and re-sprayed with release agent. It is then conveyed to the casting station via the return roller conveyor to enter the next production cycle.

2. The method for prefabrication of large-diameter segment tubes in an independent kiln with continuous flow conveying, as described in claim 1, is characterized in that... The specific implementation method of step S6, hydration heat-driven dynamic curing, is as follows: After closing the kiln's sealing door, the multi-dimensional sensor array is activated. This involves embedding temperature sensors inside the tunnel segments, surface temperature sensors, kiln temperature and humidity sensors, and concrete strength sensors. Based on real-time monitoring data from the multi-dimensional sensor array, a four-stage curing process is executed, as follows: S61. Static curing stage: Maintain a temperature of 20-25℃ and humidity of ≥90%. Based on the tricalcium aluminate content and slump parameters of the concrete, calculate the optimal static curing time of 1.2-2.0h using a mathematical model. S62. Heating stage: Increase the temperature to 45-55℃ at a rate of 10-15℃ / h, monitor the temperature difference inside and outside the tube segment in real time, and when the temperature difference is ≥20℃, reduce the heating rate to 5-8℃ / h and adjust the airflow circulation direction in the kiln simultaneously to ensure that the temperature difference is ≤25℃. S63. Constant Temperature Stage: Maintain temperature at 45-55℃ and humidity at ≥90%. Dynamically adjust the constant temperature time to 8-12 hours based on real-time concrete strength data. Supplement heat energy through a waste heat recovery device, achieving an energy saving rate of ≥30%. S64. Cooling stage: Cool down at a rate of 8-12℃ / h until the temperature difference with the environment is ≤10℃, and simultaneously increase the humidity inside the kiln to above 95% to prevent the surface of the tube segments from losing water and cracking.

3. The method for prefabrication of large-diameter segmented tubes in an independent kiln with continuous flow conveying, as described in claim 2, is characterized in that... The mathematical model in step S6 is a multiple linear regression model: ； in, For optimal stillness time, This refers to the tricalcium aluminate content in cement. The slump of the concrete. For the heating rate, For constant temperature, the regression coefficients are a=0.08-0.12, b=0.005-0.008, c=-0.05-0.03, and d=0.02-0.

04.

4. The method for prefabrication of large-diameter segmented tubes in an independent kiln with continuous flow conveying, as described in claim 1, is characterized in that... The implementation methods for step S7, demolding and finished product inspection are as follows: After curing is completed, the mold is removed from the curing kiln through the roller conveyor system, and the automatic demolding device is started. Hydraulic pushing and vacuum adsorption are used to demold the mold in combination to avoid damage to the tube segments. After demolding, the finished product is inspected by ultrasonic flaw detection, dimensional accuracy detection and impermeability test. Qualified segments are transferred to the water immersion curing area for 7-14 days of subsequent curing, while unqualified products are automatically diverted to the rework station.

5. A large-diameter segment independent kiln water conveying prefabrication system for implementing the large-diameter segment independent kiln water conveying prefabrication method according to any one of claims 1-4, characterized in that, include: Adjustable large-diameter mold system, heavy-duty continuous conveyor system, independent modular curing kiln system, intelligent collaborative control system and auxiliary production system; Adjustable large-diameter mold system for adapting to the production of segments with diameters of 3-12 meters; Heavy-duty continuous conveyor system for heavy-duty and precise transfer; Independent modular curing kiln system is used for precise temperature and humidity control and dynamic adjustment of curing parameters to prevent the segments from cracking due to temperature difference. It also features cross-kiln waste heat recovery for energy saving, modular splicing to adapt to production capacity, and ensures the strength and impermeability of the segments. The intelligent collaborative control system uses PLC controllers and cloud platforms to collect data from multiple sensors, control each system in real time, dynamically adjust and maintain, transmit parameters, and perform remote monitoring. The auxiliary production system employs intelligent hoisting, concrete placement and vibration, surface finishing and demolding, finished product inspection and waste recycling equipment to achieve precise installation of steel cages, dense concrete pouring, and non-destructive demolding of tunnel segments.

6. The large-diameter segment independent kiln flow conveyor prefabrication system according to claim 5, characterized in that, The adjustable large-diameter mold system includes a base, an arc-shaped template group, a hydraulic adjustment mechanism, a reinforcing rib locking device, and a laser positioning module; The arc-shaped template assembly is composed of 3-6 arc-shaped steel plates spliced ​​together, with wear-resistant lining plates on the inner side and welded reinforcing ribs on the outer side; the hydraulic adjustment mechanism includes a screw drive unit and a hydraulic locking unit, the screw drive unit adjusts the radius of the arc-shaped template assembly, and the hydraulic locking unit achieves tight fixation at the template splicing points; the laser positioning module includes 3 sets of laser ranging sensors, which monitor the roundness error in real time and feed it back to the control system.

7. A large-diameter segment independent kiln flow conveyor prefabrication system according to claim 5, characterized in that, The heavy-duty continuous conveyor system includes a main conveyor roller conveyor, a return roller conveyor, a positioning and calibration unit, and a drive unit. Both the main conveyor roller and the return roller adopt a modular design. The rollers are made of 40CrNiMo alloy, with a spacing of 500-600mm, and the surface is coated with a polyurethane anti-slip coating. The positioning and calibration unit includes a laser rangefinder, a hydraulic jacking device, and a pressure sensor to achieve precise positioning and anti-deviation fixation of the mold; the drive unit adopts a variable frequency motor and chain drive.

8. The large-diameter segment independent kiln flow conveyor prefabrication system according to claim 5, characterized in that, The independent modular curing kiln system includes multiple independent kiln bodies, a temperature and humidity control module, an airflow circulation module, and a waste heat recovery module. The kiln body adopts an insulated sandwich panel structure; the temperature and humidity control module includes a heat pump heating device and a steam humidification device, with a temperature control range of 10-80℃ and a humidity control range of 60%-95%RH; the airflow circulation module adopts a symmetrical circulation structure with top air supply and bottom air return, with a wind speed of 0.2-0.3m / s to ensure the uniformity of temperature and humidity inside the kiln; the waste heat recovery module includes a heat exchanger, an energy storage tank, and a cross-kiln conveying pipeline to recover waste heat from the cooling stage for use in the heating stage of other kilns.

9. A large-diameter segment independent kiln flow conveyor prefabrication system according to claim 5, characterized in that, The intelligent collaborative control system includes a PLC controller, a multi-dimensional sensor array, a cloud platform data processing module, and an actuator. The multi-dimensional sensor array includes a PT100 temperature sensor embedded inside the tunnel segment, a surface temperature sensor for the tunnel segment, a temperature and humidity sensor inside the kiln, a concrete compressive strength sensor, and a mold positioning sensor; the cloud platform data processing module has a built-in tunnel segment production database and a neural network prediction model, which dynamically generates curing curves based on sensor data and adjusts temperature and humidity parameters and transmission speed in real time; the actuator includes a mold adjustment hydraulic valve, a frequency converter driver for the transmission system, and a temperature and humidity control valve for the curing kiln.

10. A large-diameter segment independent kiln flow conveyor prefabrication system according to claim 5, characterized in that, The auxiliary production system includes intelligent hoisting equipment, a high and low hopper linkage material distribution system, an auxiliary vibration device, an automatic finishing machine, a vacuum adsorption demolding device, and finished product testing equipment; the rated lifting capacity of the intelligent hoisting equipment is ≥50t; the finished product testing equipment integrates an ultrasonic flaw detector, a laser dimension measuring instrument, and a permeability testing device.

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