Large particle size anti-segregation packing method for fusion device tmb cladding layer layered grid

Abstract

This invention belongs to the field of nuclear fusion engineering technology and discloses a layered grid anti-segregation filling method for a TBM blanket with a large particle size ratio mixed sphere bed. This method involves layering and densely filling mixed particles into multiple filling zones within each large compartment of the TBM assembly, with water-soluble paper pads added between adjacent layers. A temporary TBM top cover is installed, and the filling quality is checked, and the water-soluble paper pads are dissolved and removed. After meeting the requirements, the temporary TBM assembly cover is removed, and the permanent TBM assembly cover is installed. This invention can completely solve the problem of gravity segregation, significantly improve filling efficiency and quality, and significantly reduce particle breakage rate.

Description

Technical Field

[0001] This invention belongs to the field of nuclear fusion engineering technology, and particularly relates to a layered grid anti-segregation filling method for a TBM blanket layer of a fusion device with a large particle size ratio mixed sphere bed. Background Technology

[0002] In the experimental blanket module (TBM) for solid-state tritium breeding in magnetic confinement fusion, beryllium titanium alloy (Be) is used. 12 The hybrid spherical bed structure, with Ti spheres as neutron multiplier materials and lithium titanate (Li2TiO3) spheres as tritium breeding materials, is the mainstream technical route for the experimental blanket module of helium-cooled ceramic breeder in the International Thermonuclear Experimental Reactor (ITER) and the future China Fusion Engineering Test Reactor (CFETR).

[0003] According to Westman's binary particle packing theory (binary bimodal particle packing model), when the particle size ratio of the two types of spherical particles is 10:1 and the volume fraction of coarse particles is 70%, the theoretical maximum filling rate can reach 75%. This design can significantly improve neutron utilization efficiency and tritium breeding ratio (TBR), and the filling rate can be increased by 15%-20% compared with traditional single-particle spherical beds.

[0004] However, traditional filling techniques suffer from the following insurmountable fatal flaws when handling mixed ball beds with such a large particle size ratio (i.e., a particle size ratio of 10:1 for the two types of spherical particles): I. Severe Gravity Segregation: According to the latest research, segregation in large-particle-size mixed spherical beds is mainly caused by three mechanisms: permeation, convection, and diffusion, with permeation being the dominant mechanism under low vibration intensity. Large-particle-size Be 12 Ti microspheres (5 mm in diameter, 2.29 g / cm³) and small-diameter Li₂TiO₃ microspheres (0.5 mm in diameter, 3.32 g / cm³) are prone to gravity separation during the filling process, resulting in a volume ratio deviation of more than 20% between the upper and lower parts of the mixed ball bed, and the Lacey mixing index is usually below 0.8.

[0005] II. Filling rate is far lower than theoretical value: Large particle size Be 12 Ti microspheres easily form stable "bridging" structures, and small-diameter Li2TiO3 microspheres cannot effectively fill the gaps, with the actual filling rate only reaching 60%-65%, resulting in a decrease in the tritium proliferation ratio.

[0006] 3. High particle breakage rate: The high-speed impact during pneumatic conveying will cause a large number of brittle Li2TiO3 particles to break, and the generated dust of <0.1mm will block the purging gas channel.

[0007] IV. Inaccurate filling quality inspection methods: The traditional overall weighing method has a large error in calculating the filling rate. Summary of the Invention

[0008] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to propose a layered grid anti-segregation filling method for a TBM blanket of a fusion device with a large particle size ratio mixed sphere bed, which can completely solve the gravity segregation problem, significantly improve filling efficiency and quality, and significantly reduce particle breakage rate.

[0009] The layered grid anti-segregation packing method for the large particle size ratio mixed sphere bed of a fusion device TBM blanket according to an embodiment of the present invention includes the following steps: S1: The TBM assembly, whose internal area has been pre-cleaned and dried, is installed with the TBM temporary top cover and placed on the vibration table; wherein, the TBM assembly is divided into multiple large sections by partition plates, and each large section is divided into multiple filling areas by cooling pipes; S2: Fill each of the large sections within the TBM module with pure water and then drain it; measure the volume of the first pure water corresponding to the large sections before filling; purge and dry the internal area of ​​the TBM module. S3: Weigh out the multiple sets of Be, each accounting for 70% of the volume, that correspond to the multiple volumes of the first pure water. 12 The mass of Ti particles and Li2TiO3 particles (30% by volume), Be 12 The particle size ratio of Ti particles to Li2TiO3 particles is 10:1; S4: Combine the Be groups... 12 Ti particles and Li2TiO3 particles are added to a three-dimensional motion mixer and mixed to obtain mixed particles, ensuring that the Lacey mixing index is ≥0.97; S5: Remove the temporary top cover of the TBM, and in a Class 10,000 clean environment, layer the mixed particles from the three-dimensional motion mixer in the same group from bottom to top and fill them densely into the multiple filling areas in the corresponding large interval of the TBM component, and add water-soluble paper pads between adjacent layers. By each mixed set of Be 12 The process of filling Ti particles and Li2TiO3 particles into one of the corresponding large intervals is repeated to complete the filling of the remaining large intervals. S6: Install the temporary top cover of the TBM, measure the filling rate of the mixed particles in each of the large intervals, dissolve and drain all the water-soluble paper pads with water, detect the residual moisture in the TBM module and verify the purging pressure drop; after the filling rate, residual moisture and purging pressure drop verification all meet the requirements, remove the temporary cover of the TBM module and install the permanent cover of the TBM module.

[0010] Compared with existing technologies, the layered grid anti-segregation packing method for the TBM blanket of the fusion device according to the embodiments of the present invention has the following significant advantages: I. A fundamental breakthrough has been achieved, completely solving the problem of gravity segregation. By setting water-soluble paper pads between layers, the long-range convection channels for segregation are physically cut off, confining the permeation mechanism to a single area and ensuring that the Lacey mixing index remains stable at 0.9 or higher.

[0011] Second, it achieves the perfect "seamless" design concept: the layering function is achieved by using a completely soluble water-soluble paper pad, and there is no foreign matter residue after filling, which ensures the purity of the cladding design and does not affect the neutronics and thermal-hydraulic performance.

[0012] Third, after filling, the combined detection method of argon pressure drop detection and residual moisture detection enables the quantitative detection of residual moisture, transforming the filling quality from "experience-based judgment" to "data-driven verification".

[0013] Fourth, after filling is completed, the filling quality is ensured to meet the requirements by measuring the filling rate, residual moisture content, and purging pressure reduction test.

[0014] V. Significantly Improved Filling Rate: By adopting a customized water-soluble paper pad with zoned and layered vibration compaction process, the overall filling rate of the mixed ball bed can be stably maintained at 75%-76%, close to the maximum value calculated by Westman theory.

[0015] VI. Significantly reduced particle breakage rate: The use of three-dimensional motion mixing particles and low-intensity vibration avoids the high-speed impact of pneumatic conveying, thus reducing the particle breakage rate after loading.

[0016] In some embodiments, step S3 further includes: measuring Be 12 The saturated water absorption coefficient of Ti particles; Step S6 specifically includes the following sub-steps: S601: Install the temporary top cover of the TBM, fill the multiple large sections inside the TBM module with pure water and then drain it, measure the second pure water volume corresponding to the multiple large sections after filling; blow and dry the internal area of ​​the TBM module. S602: Composed of each of the first pure water volume, each of the second pure water volume, and Be 12 The saturated water absorption coefficient of Ti particles and the mass of Li2TiO3 weighed in each volume of the first pure water were used to calculate the filling rate of the mixed ball bed in each of the large intervals for the first time. S603: After the initial calculation of each fill rate meets the requirements, inject pure water into the TBM module to completely dissolve all the water-soluble paper pads, drain and measure the third drainage volume of each of the large intervals, and recalculate the fill rate of the mixed ball bed in each of the large intervals. If the deviation between the two calculated fill rates of the mixed ball bed in each of the large intervals is ≤ ±0.5%, then the fill rate meets the requirements; purge and dry the internal area of ​​the TBM module; S604: Perform residual moisture detection and purging pressure drop test on the interior of the TBM module; then remove the temporary cover plate of the TBM module and install the permanent cover plate of the TBM module.

[0017] In some embodiments, step S1 specifically includes the following sub-steps: S101: The TBM assembly, whose internal area has been pre-cleaned and dried, is hoisted onto the main platform of the TBM testing and transfer integrated support platform. The temporary TBM cover of the TBM testing and transfer integrated support platform is placed on the TBM assembly and detachably fastened to the main platform to form a final assembly. S102: Hoist the assembly onto the vibration table, wherein the vibration table is a piezoelectric ceramic precision vibration table; S103: Connect the gas purging pipelines of the upper and lower parts of the TBM component, which are connected to the corresponding large intervals, to the integrated test system pipelines. The integrated test system pipelines are connected to the pure water circulation system, the argon drying and purging system, and the helium leak detection test system in the integrated test system.

[0018] In some embodiments, step S2 specifically includes the following sub-steps: S201: Switch to the pure water circulation system. The gas purging pipe at the bottom of the TBM component is connected to the inlet / outlet pipe, and the gas purging pipe at the top of the TBM component is connected to the overflow pipe. The overflow pipe has a liquid level switch. S202: Open the inlet valve of the inlet / outlet pipe until the resistivity is ≥18.2MΩ. 25°C pure water is introduced into the overflow pipe connected to the upper gas purging pipeline, triggering the liquid level switch and closing the water inlet valve; after standing for 9-12 minutes, the drain valve of the inlet / drainage pipeline is opened to discharge the pure water in each of the large intervals into the metering container, and the volume of the first pure water in each of the large intervals before filling is recorded. S203: Switch to the argon drying and purging system. The gas purging pipes at the top of the TBM assembly are connected to the inlet pipes, and the gas purging pipes at the bottom of the TBM assembly are connected to the exhaust pipes. Continuously introduce 150°C drying argon gas for 1-1.1 hours to dry the internal area of ​​the TBM assembly.

[0019] In some embodiments, step S3 specifically includes the following sub-steps: S301: Be particles with an effective particle size of 5mm are obtained through grading and sieving. 12 Ti particles were graded, sieved, and dust was removed to obtain Li2TiO3 particles with an effective particle size of 0.5 mm. S302: The graded and sieved Li2TiO3 was subjected to vacuum drying, and then the saturated water absorption coefficient of the Li2TiO3 particles was tested. S303: Be after grading and screening 12 In the Ti particles and Li2TiO3 particles, multiple sets of Be, each accounting for 70% of the volume, were precisely weighed using an electronic balance with an accuracy of ±1g, corresponding to multiple volumes of the first pure water. 12 The mass of Ti particles and Li2TiO3 particles accounting for 30% of the volume.

[0020] In some embodiments, step S4 specifically includes the following sub-steps: S401: Place the Be in the same group 12 Ti particles and Li2TiO3 particles are simultaneously added to the three-dimensional motion mixer, and the rotation speed of the three-dimensional motion mixer is controlled at 15-20 rpm, and the mixing time is controlled at 10-15 minutes to obtain mixed particles. S402: Take three parallel samples from each of the upper, middle, and lower positions in the three-dimensional motion mixer, and measure the Lacey mixing index. Ensure that the Lacey mixing index after premixing is ≥0.97 before proceeding to the next filling step.

[0021] In some embodiments, step S5 specifically includes the following sub-steps: S501: Remove the temporary top cover of the TBM. In a Class 10,000 clean environment with a temperature of 20-25℃ and a relative humidity of 30-40%, use a hopper to fill the mixed particles from the three-dimensional motion mixer, and then fill them into the multiple filling areas corresponding to the large interval. When the layer thickness reaches 48-52mm, start the piezoelectric ceramic precision vibration table and simultaneously introduce a small amount of dry argon gas to apply vertical vibration with a frequency of 20-30Hz and an amplitude of 0.1-0.2mm for 30-60 seconds, so that the mixed particles of the current layer are initially compacted. S502: Add a water-soluble paper pad to the upper surface of the initially compacted current layer, and then repeat the filling process in step S501 to complete the filling of the corresponding large interval layer by layer.

[0022] In some embodiments, step S601 further includes the step of: S6011: Install the temporary top cover of the TBM, switch to the pure water circulation system, open the inlet valve of the inlet / outlet pipe, and introduce water with a resistivity ≥18.2MΩ into the TBM assembly. Fill the container with 25°C pure water until it enters the overflow pipe connected to the gas purging pipeline at the top, triggering the liquid level switch and closing the water inlet valve; let it stand for 9-12 minutes, then open the drain valve of the inlet / drainage pipeline to discharge the pure water in each of the large sections into the metering container, and record the volume of the second pure water corresponding to each of the large sections after filling. S6012: Switch to the argon drying and purging system. The gas purging pipes at the top of the TBM assembly are connected to the inlet pipes, and the gas purging pipes at the bottom of the TBM assembly are connected to the exhaust pipes. Continuously introduce 150°C drying argon gas for 1-1.1 hours to dry the internal area of ​​the TBM assembly.

[0023] In some embodiments, in step S602, the initial fill rate of each of the large intervals is calculated as (A - B - k). m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which is the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles corresponding to each of the large intervals, A is the first pure water volume corresponding to each of the large intervals before filling, and B is the second pure water volume corresponding to each of the large intervals after filling. If the initial calculated filling rate does not meet the requirements, refilling is performed.

[0024] In some embodiments, step S603 includes: S6031: After the initial calculation of each fill rate meets the requirements, disable the liquid level switch of the TBM module, open the water inlet valve, add oxygen inhibitor to the pure water, allow water to enter through the gas purge pipe at the bottom of the TBM module, and allow water to exit through the gas purge pipe at the top of the TBM module. Then, circulate 60°C pure water into each of the large sections for 20-25 minutes at a flow rate of 0.5-1.0 m³ / h to completely dissolve all water-soluble paper partitions. Finally, close the water inlet valve. S6032: After standing for 9-12 minutes, open the drain valve to drain the water from the multiple large sections, and measure the corresponding third drainage volume of the water discharged from each of the multiple large sections. The recalculated filling rate of each large section = (A - B' - k) m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which is the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles corresponding to each of the large intervals, A is the first pure water volume corresponding to each of the large intervals before filling, and B' is the third drainage volume corresponding to each of the large intervals; if the deviation of the filling rate of the two calculations corresponding to the mixed ball bed in each of the large intervals is ≤ ±0.5%, then the filling rate meets the requirements; otherwise, refilling is required. S6033: Switch to the argon drying and purging system. The gas purging pipeline at the top of the TBM assembly is connected to the inlet pipeline, and the gas purging pipeline at the bottom of the TBM assembly is connected to the exhaust pipeline. Dry argon gas at 150°C is continuously introduced for purging. The argon gas flow rate is 0.5-1.0 m³ / h, and the purging time is 2-2.5 hours. S6034: After purging, close the inlet and outlet valves to stabilize the pressure inside the mixing ball bed at 0.1 MPa; maintain the temperature of the mixing ball bed at 150℃, let it stand for 2-2.5 hours, and record the pressure change ΔP.

[0025] In some embodiments, step S604 includes: S6041: The composition of the gas inside the TBM module was analyzed using a residual gas analyzer, confirming that the H2O partial pressure was <1×10⁻⁶. -3 Pa serves as the ultimate basis for determining whether residual moisture meets the standard. S6042: Switch to the helium leak detection test system and perform a purging pressure drop test: introduce helium into the TBM component to replace the argon, and then perform pressure drop detection to obtain the measured pressure drop value. Sauter average particle size As a characteristic particle size, a binary mixing correction coefficient of 0.92 is introduced to calculate the theoretical predicted value of pressure drop for the Ergun equation; If the deviation between the measured pressure drop and the theoretical predicted pressure drop is within ±10%, then the pressure drop acceptance is qualified. S6043: Remove the temporary cover plate of the TBM module, install the permanent cover plate of the TBM module, and finally, use helium mass spectrometry to test the sealing performance, requiring a leak rate ≤1×10⁻⁶. -9 Pa m³ / s.

[0026] In some embodiments, the water-soluble paper pad is adapted to the cross-section of the corresponding filling area, and the water-soluble paper pad is a high-purity polyvinyl alcohol pad.

[0027] In some embodiments, the chemical technical requirements for the water-soluble paper mat are as follows: high-purity polyvinyl alcohol fiber is used as the main raw material, with a degree of alcoholysis of 92%-94% and a degree of polymerization of 1700-2400; purity ≥99.99%, ash content ≤0.1%; total heavy metal content <1ppm, of which Pb <0.05ppm, Cd <0.01ppm, As <0.01ppm, Hg <0.005ppm; ionic residue: Cl... - <1ppm, SO4 2- <1ppm; Dissolved residue: <10ppm; Irradiation stability: at 10 6 Under the neutron-γ mixed field of Gy, the main degradation products of the water-soluble paper pad are H2O and CO2, and trace amounts of acetic acid will be carried away by helium purging.

[0028] In some embodiments, the physical properties of the water-soluble paper pad are required to be as follows: water solubility time: completely dissolved in water at 50°C for ≤30 seconds with no adhesive residue; temperature resistance: able to withstand short-term high temperatures without decomposition; irradiation stability: under this irradiation dose, its mechanical properties can maintain the necessary operational strength, and the irradiation degradation products do not affect the cladding function.

[0029] In some embodiments, the hot pressing process requirements for the water-soluble paper pad are as follows: mold material: 316L stainless steel, surface mirror polished Ra≤0.2μm; mold preheating temperature: 90-100℃; hot pressing pressure: 0.3-0.5MPa; holding time: 15-30 seconds; cooling and demolding: keep the pressure constant, cool with water to below 40℃ for demolding; any release agent is strictly prohibited, and smooth demolding is achieved through mold mirror polishing and slight draft angle; molding environment: Class 10,000 cleanroom, temperature 20-25℃, relative humidity 30%-40%.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the assembly of the TBM component and the integrated TBM testing and transportation platform according to an embodiment of the present invention; Figure 2 This is a top view of the TBM component in an embodiment of the present invention; Figure 3 This is a three-dimensional schematic diagram of the TBM component in an embodiment of the present invention.

[0032] Figure Labels TBM assembly 1; partition plate 101; cooling pipe 102; large section 103; filling area 1031; gas purging pipe 104; main platform 2; TBM temporary top cover 3. Detailed Implementation

[0033] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] The following is combined Figures 1 to 3 This invention describes a layered grid anti-segregation filling method for a TBM blanket layer of a fusion device according to an embodiment of the present invention.

[0035] like Figures 1 to 3 As shown, the layered grid anti-segregation packing method for the TBM blanket of a fusion device according to an embodiment of the present invention includes the following steps: S1: After the TBM assembly 1, whose internal area has been pre-cleaned and dried, is installed with the TBM temporary top cover 3, it is placed on the vibration table; wherein, the TBM assembly 1 is divided into multiple large sections 103 by partition plates 101, and each large section 103 is divided into multiple filling areas 1031 by cooling pipes 102. For example, the TBM assembly 1 is divided into three large sections 103 by two partition plates 101, and each large section 103 is divided into three filling areas 1031 by cooling pipes 102. Therefore, the TBM assembly 1 is divided into 9 filling areas 1031. The partitioned design of the filling zone 1031 within the TBM assembly 1, achieved through the partition plate 101 and cooling pipes 102, is beneficial in two ways: firstly, it improves the tritium breeding efficiency and overall tritium production capacity; secondly, it enhances heat exchange in the mixed sphere bed, achieving temperature uniformity, avoiding local hot spots, improving the thermal energy conversion efficiency of the fusion energy extraction system, and ensuring stable operation of the blanket under high heat loads; furthermore, it helps reduce inter-particle friction in the mixed sphere bed and improves structural stability.

[0036] S2: Fill each large section 103 within the TBM module 1 with pure water and then drain it. Measure the volumes of the first pure water corresponding to each large section 103 before filling. This measurement is convenient, and the first pure water volume can accurately reflect the sum of the filling volumes of the multiple filling zones 1031 of the corresponding large section 103. Purge and dry the internal area of ​​the TBM module 1 to prepare for subsequent filling of the mixing ball bed.

[0037] S3: Weigh out the multiple sets of Be, each accounting for 70% of the volume, that correspond to the multiple volumes of the first pure water. 12 The mass of Ti particles and Li2TiO3 particles accounting for 30% of the volume, of which Be 12The particle size ratio of Ti particles to Li₂TiO₃ particles is 10:1. Since the total volume of the multiple filling zones 1031 within a large interval 103 is equal to the corresponding volume of a first pure water unit, the Be content, which accounts for 70% of the total volume of the multiple filling zones 1031 within this large interval 103, can be calculated. 12 The mass of Ti particles and the mass of Li₂TiO₃ particles (30% of the volume) were then precisely weighed, meaning that one volume of pure water corresponded to a set of weighed Be particles (70% of the volume). 12 Ti particles and Li2TiO3 particles accounting for 30% of the volume.

[0038] S4: Combine the Be groups... 12 Ti particles and Li2TiO3 particles are added to a three-dimensional motion mixer and mixed to obtain mixed particles, ensuring that the Lacey mixing index is ≥0.97.

[0039] S5: Remove the temporary top cover 3 of the TBM. In a Class 10,000 clean environment, layer the mixed particles from the three-dimensional motion mixer of the same group from bottom to top and fill them densely into multiple filling areas 1031 in the corresponding large interval 103 of the TBM component 1, and add water-soluble paper pads between adjacent layers.

[0040] By each mixed set of Be 12 Repeat the process of filling Ti particles and Li2TiO3 particles into the corresponding large interval 103 to complete the filling of the remaining large intervals 103.

[0041] The vibration of the vibration table compacts each layer of the mixed ball bed, stabilizes the structure of the mixed ball bed, and flattens the top surface of the current layer to better place the water-soluble paper pad.

[0042] By placing water-soluble paper pads between the layers, the long-range convection channels for segregation are physically cut off, confining the permeation mechanism to a single-layer region. This completely solves the problem of gravity segregation, ensuring the structural stability of the mixed sphere bed and maintaining a Lacey mixing index consistently above 0.95. After filling, the water-soluble paper pads can be completely dissolved and drained using pure water, ensuring no foreign matter remains after filling and guaranteeing the purity of the cladding design, without affecting neutronics and thermo-hydraulic performance.

[0043] S6: Install the temporary top cover 3 of the TBM, measure the filling rate of the mixed particles in each large section 103. If the filling rate does not meet the requirements, refill. Dissolve and drain all water-soluble paper pads with water to ensure that there are no foreign objects left after filling, ensuring the purity of the cladding and not affecting the neutronics and thermal-hydraulic performance. Test the residual moisture in the TBM module 1. If the residual moisture does not meet the requirements, purge and dry the internal area of ​​the TBM module 1 again to ensure that there are no foreign objects left after filling, ensuring the purity of the cladding and not affecting the neutronics and thermal-hydraulic performance. Verify the purging pressure drop inside the TBM module 1 to ensure the filling quality. After the filling rate, residual moisture and purging pressure drop verification all meet the requirements, remove the temporary cover plate of the TBM module 1 and install the permanent cover plate of the TBM module 1.

[0044] Compared with existing technologies, the layered grid anti-segregation packing method for the TBM blanket of the fusion device according to the embodiments of the present invention has the following significant advantages: I. A fundamental breakthrough has been achieved, completely solving the problem of gravity segregation. By setting water-soluble paper pads between layers, the long-range convection channels for segregation are physically cut off, confining the permeation mechanism to a single area and ensuring that the Lacey mixing index remains stable at 0.9 or higher.

[0045] Second, it achieves the perfect "seamless" design concept: the layering function is achieved by using a completely soluble water-soluble paper pad, and there is no foreign matter residue after filling, which ensures the purity of the cladding design and does not affect the neutronics and thermal-hydraulic performance.

[0046] Third, after filling, the combined detection method of argon pressure drop detection and residual moisture detection enables the quantitative detection of residual moisture, transforming the filling quality from "experience-based judgment" to "data-driven verification".

[0047] Fourth, after filling is completed, the filling quality is ensured to meet the requirements by measuring the filling rate, residual moisture content, and purging pressure reduction test.

[0048] V. Significantly Improved Filling Rate: By adopting a customized water-soluble paper pad with zoned and layered vibration compaction process, the overall filling rate of the mixed ball bed can be stably maintained at 75%-76%, close to the maximum value calculated by Westman theory.

[0049] VI. Significantly reduced particle breakage rate: The use of three-dimensional motion mixing particles and low-intensity vibration avoids the high-speed impact of pneumatic conveying, thus reducing the particle breakage rate after loading.

[0050] VII. High degree of engineering: The entire process flow is clear, the parameters are specific, and all equipment used is general-purpose or easy to modify.

[0051] In some embodiments, step S3 further includes: measuring Be 12Saturated water absorption coefficient of Ti particles.

[0052] Step S6 specifically includes the following sub-steps: S601: Install the temporary top cover 3 of the TBM, fill multiple large sections 103 inside the TBM module 1 with pure water and then drain it, measure the volume of the second pure water corresponding to the multiple large sections 103 after filling; blow and dry the internal area of ​​the TBM module 1.

[0053] S602: Composed of various volumes of first pure water, various volumes of second pure water, and Be 12 The saturated water absorption coefficient of Ti particles and the mass of Li2TiO3 weighed in each first pure water volume were used to calculate the filling rate of the mixed ball bed in each large interval 103 for the first time.

[0054] S603: After the initial calculation of each filling rate meets the requirements, inject pure water into TBM module 1 to completely dissolve all water-soluble paper pads, drain and measure the third drainage volume of each large section 103, and recalculate the filling rate of the mixed ball bed in each large section 103. If the deviation between the two calculated filling rates of the mixed ball bed in each large section 103 is ≤ ±0.5%, the filling rate meets the requirements. If the filling rate does not meet the requirements, refill; purge and dry the internal area of ​​TBM module 1.

[0055] The proposed modified water volume measurement method improves the accuracy of filling rate measurement.

[0056] S604: Perform residual moisture detection and purging pressure drop test on the interior of TBM module 1; then remove the temporary cover plate of TBM module 1 and install the permanent cover plate of TBM module 1. Residual moisture detection enables quantitative detection of residual moisture, transforming filling quality from "experience-based judgment" to "data-driven verification." The purging pressure drop test ensures filling quality.

[0057] In some embodiments, step S1 specifically includes the following sub-steps: S101: Hoist the pre-cleaned and dried TBM module 1 onto the main platform 2 of the integrated TBM testing and transfer platform. Place the temporary TBM cover 3 of the integrated TBM testing and transfer platform onto the TBM module 1 and secure it detachably to the main platform 2, forming the final assembly. By integrating the TBM module 1 onto the integrated TBM testing and transfer platform to form the final assembly, the irreversible rework problem in existing technologies can be completely solved: all filling quality inspections and process treatments are completed before the official TBM cover is closed. If problems such as insufficient filling rate are found, additional particles can be added directly, avoiding the risk of scrapping or reworking the entire TBM module.

[0058] S102: Hoist the assembly onto the vibration table, which is a piezoelectric ceramic precision vibration table. The piezoelectric ceramic precision vibration table is used to compact the filling layer of the mixed ball bed by applying low-intensity vertical vibration.

[0059] S103: Connect the gas purging lines 104, which connect the upper and lower parts of TBM component 1 to the corresponding large sections 103, to the integrated test system pipeline. The integrated test system pipeline is connected to the pure water circulation system, argon drying and purging system, and helium leak detection system within the integrated test system. All of these systems—including the integrated test system's pure water circulation system, argon drying and purging system, and helium leak detection system—are general-purpose or easily modified equipment.

[0060] In some embodiments, step S2 specifically includes the following sub-steps: S201: Switch to pure water circulation system. The gas purging pipe 104 at the bottom of TBM component 1 is connected to the inlet / drainage pipe respectively. The gas purging pipe 104 at the top of TBM component 1 is connected to the overflow pipe respectively. There is a liquid level switch on the overflow pipe.

[0061] S202: Open the inlet valve of the inlet / drain pipe until the resistivity is ≥18.2MΩ. 25°C pure water is introduced into the overflow pipe connected to the upper gas purging pipeline 104, triggering the liquid level switch and closing the water inlet valve; after standing for 9-12 minutes, the drain valve of the inlet / drainage pipeline is opened to discharge the pure water in each large interval 103 into the metering container, and the first pure water volume corresponding to each large interval 103 before filling is recorded.

[0062] Through steps S201 and S202, the volume of the first pure water corresponding to each large interval 103 before filling can be accurately measured.

[0063] S203: Switch to the argon drying and purging system. The gas purging pipe 104 at the top of the TBM component 1 is connected to the inlet pipe, and the gas purging pipe 104 at the bottom of the TBM component 1 is connected to the exhaust pipe. 150°C drying argon gas is continuously introduced for 1-1.1 hours to dry the internal area of ​​the TBM component 1.

[0064] In some embodiments, step S3 specifically includes the following sub-steps: S301: Be particles with an effective particle size of 5mm are obtained through grading and sieving. 12 Ti particles are graded, sieved, and dust is removed to obtain Li2TiO3 particles with an effective particle size of 0.5 mm.

[0065] S302: The graded and sieved Li2TiO3 was subjected to vacuum drying, and then the saturated water absorption coefficient of the Li2TiO3 particles was tested.

[0066] S303: Be after grading and screening 12 In Ti particles and Li₂TiO₃ particles, multiple sets of Be, each accounting for 70% of the volume, were precisely weighed using an electronic balance with an accuracy of ±1g, corresponding to multiple volumes of first pure water. 12 The mass of Ti particles and Li2TiO3 particles accounting for 30% of the volume.

[0067] In some embodiments, step S4 specifically includes the following sub-steps: S401: Place the Be in the same group 12 Ti particles and Li₂TiO₃ particles were simultaneously added to a three-dimensional motion mixer. The speed of the three-dimensional motion mixer was controlled at 15-20 rpm, and the mixing time was controlled at 10-15 minutes to obtain mixed particles. Be was then mixed using a three-dimensional motion mixer. 12 Ti particles and Li2TiO3 particles can prevent particle breakage.

[0068] S402: Take three parallel samples from each of the upper, middle, and lower positions in the three-dimensional motion mixer and measure the Lacey mixing index. Ensure that the Lacey mixing index after premixing is ≥0.97 before proceeding to the next filling step.

[0069] In some embodiments, step S5 specifically includes the following sub-steps: S501: Remove the temporary top cover 3 of the TBM. In a Class 10,000 clean environment with a temperature of 20-25℃ and a relative humidity of 30-40%, use a hopper to fill the mixed particles from the three-dimensional motion mixer. Then, fill the multiple filling zones 1031 of the corresponding large interval 103. When the layer thickness reaches 48-52mm, start the piezoelectric ceramic precision vibration table and simultaneously introduce a small amount of dry argon gas. Apply vertical vibration with a frequency of 20-30Hz and an amplitude of 0.1-0.2mm for 30-60 seconds to initially compact the mixed particles of the current layer.

[0070] By using a hopper to fill the three-dimensional motion mixer with mixed particles, and then filling the multiple filling zones 1031 corresponding to the large interval 103, particle breakage can be avoided. During vibration of the piezoelectric ceramic precision vibration table, a small amount of dry argon gas is introduced, and vertical vibration with a frequency of 20-30Hz and an amplitude of 0.1-0.2mm is applied for 30-60 seconds. This ensures that the current layer is compacted, stabilizing the mixed ball bed structure and flattening the top surface of the current layer, while also preventing particle breakage.

[0071] S502: Add a water-soluble paper pad to the upper surface of the initially compacted current layer, and then repeat the filling process in step S501 to complete the filling of the corresponding large interval 103 layer by layer.

[0072] In some embodiments, step S601 further includes the step of: S6011: Install the TBM temporary top cover 3, switch to the pure water circulation system, open the inlet valve of the inlet / drainage pipe, and introduce water with a resistivity ≥18.2MΩ into the TBM component 1. Fill the container with 25°C pure water until it enters the overflow pipe connected to the upper gas purging line 104, triggering the level switch and closing the inlet valve. Let it stand for 9-12 minutes, then open the drain valve of the inlet / drainage line to drain the pure water in each large section 103 into the metering container, and record the second pure water volume corresponding to each large section 103 after filling.

[0073] Step S6011 allows for the precise measurement of the second pure water volume corresponding to the filling of each large interval 103.

[0074] S6012: Switch to the argon drying and purging system. The gas purging pipe 104 at the top of the TBM component 1 is connected to the inlet pipe, and the gas purging pipe 104 at the bottom of the TBM component 1 is connected to the exhaust pipe. 150°C drying argon gas is continuously introduced for 1-1.1 hours to dry the internal area of ​​the TBM component 1.

[0075] In some embodiments, in step S602, the initial fill rate of each large interval 103 is calculated as (A - B - k). m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which refers to the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles corresponding to each large interval 103, A is the first pure water volume corresponding to each large interval 103 before filling, and B is the second pure water volume corresponding to each large interval 103 after filling. If the initial calculated filling rate does not meet the requirements, refilling is performed. Through error analysis: the corrected measurement uncertainty is less than 0.2% (the deviation rate is less than 0.2% under extremely high probability, such as 95% probability), which is far better than the ±2% of the existing overall weighing method. Compared with the existing overall weighing method for measuring filling rate, this corrected water volume measurement method effectively improves the accuracy of filling rate measurement.

[0076] In some cases, step S603 includes: S6031: After the initial calculation of each fill rate meets the requirements, disable the liquid level switch of TBM component 1, open the water inlet valve, add oxygen inhibitor to the pure water, allow water to enter through the gas purge pipe 104 at the bottom of TBM component 1, and allow water to exit through the gas purge pipe 104 at the top of TBM component 1. Then, circulate 60℃ pure water into each large compartment 103 for 20-25 minutes at a flow rate of 0.5-1.0 m³ / h to completely dissolve all water-soluble paper partitions, and then close the water inlet valve.

[0077] The oxygen inhibitor added to the pure water is 0.1 ppm sodium nitrite, which avoids chemical reaction with Li2TiO3 and effectively protects Li2TiO3.

[0078] S6032: After standing for 9-12 minutes, open the drain valve to drain the water from multiple large sections 103, and measure the corresponding third drainage volume of the water drained from each of the multiple large sections 103. The recalculated filling rate of each large section 103 is calculated as follows: (A - B' - k) m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which is the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles in each large interval 103, A is the first pure water volume corresponding to each large interval 103 before filling, and B' is the third drainage volume corresponding to each large interval 103; if the deviation of the filling rate of the two calculations of the mixed ball bed in each large interval 103 is ≤±0.5%, then the corresponding filling rate meets the requirements; otherwise, the mixed ball bed in the corresponding large interval 103 is refilled.

[0079] S6033: Switch to the argon drying and purging system. The gas purging pipe 104 at the top of the TBM component 1 is connected to the inlet pipe, and the gas purging pipe 104 at the bottom of the TBM component 1 is connected to the exhaust pipe. Dry argon gas at 150℃ is continuously introduced for purging. The argon gas flow rate is 0.5-1.0 m³ / h, and the purging time is 2-2.5 hours.

[0080] S6034: After purging, close the inlet and outlet valves to stabilize the pressure inside the mixing ball bed at 0.1 MPa; maintain the temperature of the mixing ball bed at 150℃, let it stand for 2-2.5 hours, and record the pressure change ΔP. Quantitative detection of residual moisture can be achieved through argon pressure drop detection, transforming filling quality from "experience-based judgment" to "data-driven verification."

[0081] In some embodiments, step S604 includes: S6041: The composition of the gas inside TBM module 1 was analyzed using a residual gas analyzer, confirming that the H2O partial pressure is <1×10⁻⁶.-3 Pa serves as the ultimate basis for determining whether residual moisture meets standards. Quantitative detection of residual moisture is achieved through a residual gas analyzer, transforming filling quality from "experience-based judgment" to "data-driven verification."

[0082] S6042: Switch to the helium leak detection test system and perform a purging pressure drop test: Introduce helium into TBM component 1 to replace the argon gas, and then perform pressure drop detection to obtain the measured pressure drop value. Sauter average particle size As a characteristic particle size, a binary mixing correction coefficient of 0.92 is introduced to calculate the theoretical predicted value of pressure drop for the Ergun equation; If the deviation between the measured pressure drop and the theoretical predicted pressure drop is within ±10%, then the pressure drop acceptance is qualified. S6043: Remove the temporary cover plate of TBM component 1, install the permanent cover plate of TBM component 1, and finally, use helium mass spectrometry to test the sealing performance, requiring a leak rate ≤1×10⁻⁶. -9 Pa m³ / s.

[0083] In some embodiments, the water-soluble paper pad is adapted to the cross-section of the corresponding filling area 1031, and the water-soluble paper pad is a high-purity polyvinyl alcohol pad. The high-purity polyvinyl alcohol pad is a completely soluble nuclear industry-grade water-soluble paper, placed between the layers of the filled mixed ball bed. After filling, there are no foreign matter residues, ensuring the purity of the cladding design and not affecting neutronics and thermo-hydraulic performance.

[0084] In some embodiments, the chemical technical requirements for water-soluble paper mats are as follows: high-purity polyvinyl alcohol fiber is used as the main raw material; degree of alcoholysis 92%-94% (warm water soluble type); degree of polymerization 1700-2400; purity ≥99.99%; ash content ≤0.1% (800℃ ignition method, GB / T 742-2008); total heavy metal content <1ppm, of which Pb <0.05ppm, Cd <0.01ppm, As <0.01ppm, Hg <0.005ppm (ICP-MS method, GB / T 40272-2021); ion residue: Cl... - <1ppm, SO4 2- <1ppm (ion chromatography); dissolved residue: <10ppm; radiation stability: at 10 6 Under the neutron-γ mixed field of Gy, the main degradation products of water-soluble paper pads are H2O and CO2, while trace amounts of acetic acid (<0.1ppm) will be carried away by helium purging.

[0085] In some embodiments, the physical properties of the water-soluble paper pad are required to be as follows: water solubility time: complete dissolution in water at 50°C for ≤30 seconds with no adhesive residue; temperature resistance: able to withstand short-term high temperatures (e.g., 2 hours at 180°C) without decomposition; irradiation stability: at this irradiation dose, its mechanical properties can maintain the necessary operational strength, and the irradiation degradation products do not affect the cladding function.

[0086] In some embodiments, the hot pressing process requirements for water-soluble paper pads are as follows: mold material: 316L stainless steel, surface mirror polished (Ra≤0.2μm); mold preheating temperature: 90-100℃; hot pressing pressure: 0.3-0.5MPa; holding time: 15-30 seconds; cooling and demolding: keep the pressure constant, cool with water to below 40℃ for demolding; any release agent is strictly prohibited, and smooth demolding is achieved through mold mirror polishing and slight draft angle; molding environment: Class 10,000 cleanroom, temperature 20-25℃, relative humidity 30%-40%.

[0087] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preventing segregation in a layered grid of mixed spheres with a large particle size ratio for the blanket of a fusion device TBM, characterized in that, Includes the following steps: S1: The TBM assembly, whose internal area has been pre-cleaned and dried, is installed with the TBM temporary top cover and placed on the vibration table; wherein, the TBM assembly is divided into multiple large sections by partition plates, and each large section is divided into multiple filling areas by cooling pipes; S2: Fill each of the large sections within the TBM module with pure water and then drain it; measure the volume of the first pure water corresponding to the large sections before filling; purge and dry the internal area of ​​the TBM module. S3: Weigh out the multiple sets of Be, each accounting for 70% of the volume, that correspond to the multiple volumes of the first pure water. 12 The mass of Ti particles and Li2TiO3 particles (30% by volume), Be 12 The particle size ratio of Ti particles to Li2TiO3 particles is 10:1; S4: Place the Be in the same group 12 Ti particles and Li2TiO3 particles are added to a three-dimensional motion mixer and mixed to obtain mixed particles, ensuring that the Lacey mixing index is ≥0.97; S5: Remove the temporary top cover of the TBM, and in a Class 10,000 clean environment, layer the mixed particles from the three-dimensional motion mixer in the same group from bottom to top and fill them densely into the multiple filling areas in the corresponding large interval of the TBM component, and add water-soluble paper pads between adjacent layers. By each mixed set of Be 12 The process of filling Ti particles and Li2TiO3 particles into one of the corresponding large intervals is repeated to complete the filling of the remaining large intervals. S6: Install the temporary top cover of the TBM, measure the filling rate of the mixed particles in each of the large intervals, dissolve and drain all the water-soluble paper pads with water, detect the residual moisture in the TBM module and verify the purging pressure drop; after the filling rate, residual moisture and purging pressure drop verification all meet the requirements, remove the temporary cover of the TBM module and install the permanent cover of the TBM module.

2. The method for preventing segregation in a layered grid of mixed spheres with a large particle size ratio for the TBM blanket of a fusion device according to claim 1, characterized in that, Step S3 also includes: measuring Be 12 The saturated water absorption coefficient of Ti particles; Step S6 specifically includes the following sub-steps: S601: Install the temporary top cover of the TBM, fill the multiple large sections inside the TBM module with pure water and then drain it, measure the second pure water volume corresponding to the multiple large sections after filling; blow and dry the internal area of ​​the TBM module. S602: Composed of each of the first pure water volume, each of the second pure water volume, and Be 12 The saturated water absorption coefficient of Ti particles and the mass of Li2TiO3 weighed in each volume of the first pure water were used to calculate the filling rate of the mixed ball bed in each of the large intervals for the first time. S603: After the initial calculation of each fill rate meets the requirements, inject pure water into the TBM module to completely dissolve all the water-soluble paper pads, drain and measure the third drainage volume of each of the large intervals, and recalculate the fill rate of the mixed ball bed in each of the large intervals. If the deviation between the two calculated fill rates of the mixed ball bed in each of the large intervals is ≤ ±0.5%, then the fill rate meets the requirements; purge and dry the internal area of ​​the TBM module; S604: Perform residual moisture detection and purging pressure drop test on the interior of the TBM module; then remove the temporary cover plate of the TBM module and install the permanent cover plate of the TBM module.

3. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 2, characterized in that, Step S1 specifically includes the following sub-steps: S101: The TBM assembly, whose internal area has been pre-cleaned and dried, is hoisted onto the main platform of the TBM testing and transfer integrated support platform. The temporary TBM cover of the TBM testing and transfer integrated support platform is placed on the TBM assembly and detachably fastened to the main platform to form a final assembly. S102: Hoist the assembly onto the vibration table, wherein the vibration table is a piezoelectric ceramic precision vibration table; S103: Connect the gas purging pipelines of the upper and lower parts of the TBM component, which are connected to the corresponding large intervals, to the integrated test system pipelines. The integrated test system pipelines are connected to the pure water circulation system, the argon drying and purging system, and the helium leak detection test system in the integrated test system.

4. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 3, characterized in that, Step S2 specifically includes the following sub-steps: S201: Switch to the pure water circulation system. The gas purging pipe at the bottom of the TBM component is connected to the inlet / outlet pipe, and the gas purging pipe at the top of the TBM component is connected to the overflow pipe. The overflow pipe has a liquid level switch. S202: Open the inlet valve of the inlet / outlet pipe until the resistivity is ≥18.2MΩ. 25°C pure water is introduced into the overflow pipe connected to the upper gas purging pipeline, triggering the liquid level switch and closing the water inlet valve; after standing for 9-12 minutes, the drain valve of the inlet / drainage pipeline is opened to discharge the pure water in each of the large intervals into the metering container, and the volume of the first pure water in each of the large intervals before filling is recorded. S203: Switch to the argon drying and purging system. The gas purging pipes at the top of the TBM assembly are connected to the inlet pipes, and the gas purging pipes at the bottom of the TBM assembly are connected to the exhaust pipes. Continuously introduce 150°C drying argon gas for 1-1.1 hours to dry the internal area of ​​the TBM assembly.

5. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 4, characterized in that, Step S3 specifically includes the following sub-steps: S301: Be particles with an effective particle size of 5mm are obtained through grading and sieving. 12 Ti particles were graded, sieved, and dust was removed to obtain Li2TiO3 particles with an effective particle size of 0.5 mm. S302: The graded and sieved Li2TiO3 was subjected to vacuum drying, and then the saturated water absorption coefficient of the Li2TiO3 particles was tested. S303: Be after grading and screening 12 In the Ti particles and Li2TiO3 particles, multiple sets of Be, each accounting for 70% of the volume, were precisely weighed using an electronic balance with an accuracy of ±1g, corresponding to multiple volumes of the first pure water. 12 The mass of Ti particles and Li2TiO3 particles accounting for 30% of the volume.

6. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 5, characterized in that, Step S4 specifically includes the following sub-steps: S401: Place the Be in the same group 12 Ti particles and Li2TiO3 particles are simultaneously added to the three-dimensional motion mixer, and the rotation speed of the three-dimensional motion mixer is controlled at 15-20 rpm, and the mixing time is controlled at 10-15 minutes to obtain mixed particles. S402: Take three parallel samples from each of the upper, middle, and lower positions in the three-dimensional motion mixer, and measure the Lacey mixing index. Ensure that the Lacey mixing index after premixing is ≥0.97 before proceeding to the next filling step.

7. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 6, characterized in that, Step S5 specifically includes the following sub-steps: S501: Remove the temporary top cover of the TBM. In a Class 10,000 clean environment with a temperature of 20-25℃ and a relative humidity of 30-40%, use a hopper to fill the mixed particles from the three-dimensional motion mixer, and then fill them into the multiple filling areas corresponding to the large interval. When the layer thickness reaches 48-52mm, start the piezoelectric ceramic precision vibration table and simultaneously introduce a small amount of dry argon gas to apply vertical vibration with a frequency of 20-30Hz and an amplitude of 0.1-0.2mm for 30-60 seconds, so that the mixed particles of the current layer are initially compacted. S502: Add a water-soluble paper pad to the upper surface of the initially compacted current layer, and then repeat the filling process in step S501 to complete the filling of the corresponding large interval layer by layer.

8. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 6, characterized in that, Step S601 further includes the following steps: S6011: Install the temporary top cover of the TBM, switch to the pure water circulation system, open the inlet valve of the inlet / outlet pipe, and introduce water with a resistivity ≥18.2MΩ into the TBM assembly. Fill the container with 25°C pure water until it enters the overflow pipe connected to the gas purging pipeline at the top, triggering the liquid level switch and closing the water inlet valve; let it stand for 9-12 minutes, then open the drain valve of the inlet / drainage pipeline to discharge the pure water in each of the large sections into the metering container, and record the volume of the second pure water corresponding to each of the large sections after filling. S6012: Switch to the argon drying and purging system. The gas purging pipes at the top of the TBM assembly are connected to the inlet pipes, and the gas purging pipes at the bottom of the TBM assembly are connected to the exhaust pipes. Continuously introduce 150°C drying argon gas for 1-1.1 hours to dry the internal area of ​​the TBM assembly.

9. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 8, characterized in that, In step S602, the initial fill rate of each of the large intervals is calculated as (A - B - k). m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which is the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles corresponding to each of the large intervals, A is the first pure water volume corresponding to each of the large intervals before filling, and B is the second pure water volume corresponding to each of the large intervals after filling. If the initial calculated filling rate does not meet the requirements, refilling is performed.

10. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 9, characterized in that, Step S603 includes: S6031: After the initial calculation of each fill rate meets the requirements, disable the liquid level switch of the TBM module, open the water inlet valve, add oxygen inhibitor to the pure water, allow water to enter through the gas purge pipe at the bottom of the TBM module, and allow water to exit through the gas purge pipe at the top of the TBM module. Then, circulate 60°C pure water into each of the large sections for 20-25 minutes at a flow rate of 0.5-1.0 m³ / h to completely dissolve all water-soluble paper partitions. Finally, close the water inlet valve. S6032: After standing for 9-12 minutes, open the drain valve to drain the water from the multiple large sections, and measure the corresponding third drainage volume of the water discharged from each of the multiple large sections. The recalculated filling rate of each large section = (A - B' - k) m_Li) / A 100%, where k is the saturated water absorption coefficient of Li2TiO3 particles, which is the coefficient of the saturated water absorption volume of Li2TiO3 particles per unit mass, m_Li is the total mass of Li2TiO3 particles corresponding to each of the large intervals, A is the first pure water volume corresponding to each of the large intervals before filling, and B' is the third drainage volume corresponding to each of the large intervals; if the deviation of the filling rate of the two calculations corresponding to the mixed ball bed in each of the large intervals is ≤ ±0.5%, then the filling rate meets the requirements; otherwise, refilling is required. S6033: Switch to the argon drying and purging system. The gas purging pipeline at the top of the TBM assembly is connected to the inlet pipeline, and the gas purging pipeline at the bottom of the TBM assembly is connected to the exhaust pipeline. Dry argon gas at 150°C is continuously introduced for purging. The argon gas flow rate is 0.5-1.0 m³ / h, and the purging time is 2-2.5 hours. S6034: After purging, close the inlet and outlet valves to stabilize the pressure inside the mixing ball bed at 0.1 MPa; maintain the temperature of the mixing ball bed at 150℃, let it stand for 2-2.5 hours, and record the pressure change ΔP.

11. The method for preventing segregation in a layered grid of mixed spheres with a large particle size ratio for the TBM blanket of a fusion device according to claim 10, characterized in that, Step S604 includes: S6041: The composition of the gas inside the TBM module was analyzed using a residual gas analyzer, confirming that the H2O partial pressure was <1×10⁻⁶. -3 Pa serves as the final basis for determining whether residual moisture meets the standard; S6042: Switch to the helium leak detection test system and conduct a purging pressure drop test: Introduce helium into the TBM component to replace the argon gas, and then perform pressure drop detection to obtain the measured pressure drop value; Sauter average particle size As a characteristic particle size, a binary mixing correction coefficient of 0.92 is introduced to calculate the theoretical predicted value of pressure drop for the Ergun equation; If the deviation between the measured pressure drop and the theoretical predicted pressure drop is within ±10%, then the pressure drop acceptance is qualified. S6043: Remove the temporary cover plate of the TBM module, install the permanent cover plate of the TBM module, and finally, use helium mass spectrometry to test the sealing performance, requiring a leak rate ≤1×10⁻⁶. -9 Pa m³ / s.

12. The method for preventing segregation in a layered grid of large-particle-size mixed spheres for the TBM blanket of a fusion device according to any one of claims 1-11, characterized in that, The water-soluble paper pad is adapted to the cross-section of the corresponding filling area, and the water-soluble paper pad is a high-purity polyvinyl alcohol pad.

13. The layered grid anti-segregation filling method for the TBM blanket of a fusion device according to claim 12, characterized in that, The chemical technical requirements for the water-soluble paper pad are as follows: high-purity polyvinyl alcohol fiber is used as the main raw material, with a degree of alcoholysis of 92%-94% and a degree of polymerization of 1700-2400. Purity ≥ 99.99%, ash content ≤ 0.1%; total heavy metal content < 1 ppm, of which Pb < 0.05 ppm, Cd < 0.01 ppm, As < 0.01 ppm, Hg < 0.005 ppm; residual ions: Cl - <1ppm, SO4 2- <1ppm; Dissolved residue: <10ppm; Irradiation stability: at 10 6 Under the neutron-γ mixed field of Gy, the main degradation products of the water-soluble paper pad are H2O and CO2, and trace amounts of acetic acid will be carried away by helium purging.

14. The fusion device TBM blanket large particle size ratio mixed spherical bed layered lattice grid anti segregation packing method according to claim 13, characterized in that, The physical performance requirements for the water-soluble paper mat are as follows: water dissolution time: ≤30 seconds in water at 50℃ for complete dissolution with no adhesive residue; Temperature resistance: It can withstand short-term high temperatures without decomposition; Irradiation stability: Under this irradiation dose, its mechanical properties can maintain the necessary operational strength, and the irradiation degradation products do not affect the coating function.

15. The fusion device TBM blanket large particle size ratio mixed spherical bed layered lattice grid anti segregation packing method according to claim 14, characterized in that, The hot pressing process requirements for the water-soluble paper pad are as follows: mold material: 316L stainless steel, surface mirror polished Ra≤0.2μm; mold preheating temperature: 90-100℃; hot pressing pressure: 0.3-0.5MPa; holding time: 15-30 seconds; cooling and demolding: keep the pressure constant, cool with water to below 40℃ for demolding; any release agent is strictly prohibited, and smooth demolding is achieved through mold mirror polishing and slight draft angle; molding environment: Class 10,000 cleanroom, temperature 20-25℃, relative humidity 30%-40%.

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