A fusion reactor divertor tube-plate composite module and cooling target plate structure

Abstract

This invention discloses a fusion reactor divertor tube-plate composite module and cooling target plate structure, relating to the field of magnetic confinement fusion divertor technology. The composite module includes a plasma-facing component and a transition layer. The plasma-facing component is located on the periphery and is used for contact with the plasma. A through-hole matching the transition layer is provided in the plasma-facing component. The transition layer is metallurgically connected within the through-hole, and a cooling pipe is metallurgically connected within the transition layer. Coolant flows through the cooling pipe to remove heat generated by fusion. The outer side of the transition layer has a U-shaped structure with a flat top and a round bottom, while the inner side has a circular structure. This design effectively increases the weight ratio of the transition layer to the plasma-facing component, improving the overall thermal conductivity of the composite module, alleviating stress and strain concentration problems, and ensuring the safety of the divertor target plate module, preventing the target plate material from detaching and contaminating the reactor core plasma under high heat loads.

Description

Technical Field

[0001] This invention relates to the field of magnetic confinement nuclear fusion divertor technology, specifically to a fusion reactor divertor tube-plate composite module and cooling target plate structure. Background Technology

[0002] The divertor is a crucial component of a toroidal fusion reactor. It not only removes helium ash generated during the fusion reaction and shields against impurities from the reactor walls, reducing contamination of the central plasma, but also removes the energy and particle flows generated by the fusion plasma. This results in a very high heat load on the divertor target plate, damaging the divertor components and affecting its lifespan. As the plasma-facing component of the fusion reactor, the divertor needs to withstand extremely high heat loads and remove the heat. The divertor target plate employs active cooling, removing heat through cooling channels.

[0003] In the divertor target plate structure, the material directly in contact with the heat flow is the plasma-facing material. Tungsten (W) is considered the most likely plasma-facing material to be widely used in future nuclear fusion reactors due to its advantages such as high melting point (3410±20℃), high thermal conductivity, low sputtering yield, low nuclear reactivity, and low hydrogen isotope retention. Directly connected to the tungsten is an oxygen-free copper interlayer, which plays a role in mitigating the thermal stress between the plasma-facing material and the structural material. The coolant is wrapped in cooling pipes, which need to serve the dual functions of heat sink material and component structural material. Therefore, they need to have both excellent thermal conductivity and a certain strength. Connected to the cooling pipes is the structural material, which is responsible for improving the overall strength of the structure.

[0004] In summary, the divertor target plate module is a complex structure "stacked" from several materials. Due to the different thermodynamic properties of these materials, the temperature and stress distribution of the divertor module is uneven under high heat flux. How to reduce the stress level of the module and improve the fatigue life of the materials and the module is a hot research direction.

[0005] Currently, two types of divertor target modules are widely used and researched worldwide: flat plate modules and through-tube modules. The main advantages of flat plate modules are their simple structure, lower temperature compared to through-tube modules, and more uniform temperature distribution on the plasma surface. However, their disadvantage is that if the target material cracks under high heat loads, it can easily detach and contaminate the core plasma. The HL-3 divertor target module at the Southwestern Institute of Physics of the Nuclear Industry uses this structure. Through-tube modules, on the other hand, have the advantage of simple structure and can prevent target material detachment and contamination of the core plasma under high heat loads. The International Thermonuclear Experimental Reactor (ITER) has selected tungsten-copper through-tube modules as its main target structure in the high heat flux region near the divertor impact point. Experimental and simulation results show that this structure can meet the design requirements of the ITER divertor, namely, it can withstand 10 MW / m² heat flux. 2 Steady-state heat flux of 5000 cycles and able to withstand 20MW / m 2 Quasi-steady-state heat flow 300 times.

[0006] However, for future fusion reactors, the plasma heat flux will be even higher. For safety reasons, 20MW / m² is often used. 2 The steady-state heat flux is used as the thermal loading condition for evaluating the structural reliability of the divertor. Simulation and experimental results from both domestic and international sources show that at 10 MW / m²... 2 Under heat load, the target plate temperature of the ITER-like pipe-through module will reach 1000℃, while at 20MW / m 2 Under thermal load, the temperature of the target plate will exceed 1800℃, which may cause damage to the plasma-facing materials and components of the divertor. For example, the materials may undergo severe recrystallization, surface plastic deformation and local melting, and macroscopic large cracks. The components may undergo interface plastic deformation and cracking, ultimately leading to component failure, thereby affecting the service life of the divertor components and the safe operation of the device.

[0007] Therefore, developing new structural modules that can simultaneously reduce module temperature and stress, extend module fatigue life, and ensure the safety of divertor target modules is one of the key focuses and trends in the future research and development of divertor components and materials for fusion reactors. Summary of the Invention

[0008] The purpose of this invention is to provide a fusion reactor divertor tube-plate composite module and cooling target plate structure. By combining the high heat exchange capacity of the plate module and the safety of the tube module, the temperature and stress of the divertor target plate module are reduced and the fatigue life of the module is extended. At the same time, the safety of the divertor target plate module is ensured, and the target plate material is prevented from falling off under high heat load and contaminating the core plasma.

[0009] This invention is achieved through the following technical solution:

[0010] A fusion reactor divertor tube-plate composite module includes a composite module comprising a plasma-facing component and a transition layer. The plasma-facing component is located on the periphery and is used to contact the plasma. The plasma-facing component is provided with a through hole matching the transition layer. The transition layer is metallurgically connected to the through hole. A cooling pipe is metallurgically connected to the transition layer. Coolant flows through the cooling pipe to remove the heat generated by fusion.

[0011] The outer side of the transition layer has a U-shaped structure with a flat top and a round bottom, while the inner side of the transition layer has a circular structure.

[0012] In this design, the outer side of the transition layer of the composite module is a U-shaped structure with a flat top and a round bottom, and the inner side is a circular structure. The inner and outer sides of the transition layer of the ITER tube-through module are both circular structures. This design can effectively increase the proportion of the transition layer and the plasma-facing components, improve the overall thermal conductivity of the composite module, and alleviate the stress and strain concentration problems of the composite module.

[0013] As a further technical solution for the composite module, the U-shaped upper plane of the transition layer faces the fusion center, further reducing the plastic deformation generated during the heat flow loading process.

[0014] As a further technical solution of the composite module, the plasma-facing component has a cuboid structure, which effectively reduces the average heat flux on the plasma-facing surface.

[0015] As a further technical solution of the composite module, the width of the plasma-facing component is 22mm to 35mm, the height of the plasma-facing component is 25mm to 35mm, and the thickness of the plasma-facing component is 8mm to 15mm, further reducing the average heat flux on the surface of the plasma-facing component.

[0016] As a further technical solution of the composite module, the rounded corners between the U-shaped upper plane and the U-shaped lower arc surface of the transition layer, and the rounded corner structure between the transition layer and the U-shaped upper plane and the U-shaped lower arc surface of the plasma-facing component, can more uniformly and effectively export energy from the plasma, making the temperature gradient between the surface of the plasma-facing component and the cooling pipe smaller, while alleviating the thermal stress concentration phenomenon caused by the highest temperature point on the surface of the plasma-facing component.

[0017] As a further technical solution for the composite module, the radius of the rounded corner between the U-shaped upper plane and the U-shaped lower arc surface of the transition layer is 0mm to 8mm, which further alleviates the thermal stress concentration phenomenon caused by the highest temperature point on the surface of the plasma component.

[0018] As a further technical solution of the composite module, the material of the plasma-facing component is tungsten, the material of the transition layer is oxygen-free copper (OFHC), and the material of the cooling pipe is zirconium-chromium-copper alloy (CuCrZr), which improves the heat exchange capacity of the module and enhances the reliability of the module structure.

[0019] As a further technical solution of the composite module, the maximum distance between the inner wall of the through hole and the outer surface of the plasma-facing component facing the fusion center is 5mm to 8mm, which reduces the thermal stress concentration caused by uneven heat distribution.

[0020] A divertor cooling target plate structure, wherein a fusion reactor divertor tube-plate composite module as described in any of the above technical solutions is connected in series along the axial direction to form a single-channel cooling module, and multiple single-channel cooling modules are connected in parallel to form a structural whole.

[0021] As a further technical solution to the cooling target plate structure, each of the single-channel cooling modules has a baffle plate that enhances heat exchange efficiency installed inside the cooling pipe.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. This invention effectively reduces the module temperature and homogenizes the temperature distribution on the plasma-facing surface by appropriately increasing the proportion of the transition layer material and the plasma-facing component material. This achieves the purpose of reducing the stress level in the high-temperature zone of the upper part of the plasma-facing component and reducing the plastic deformation of the plasma-facing component.

[0024] 2. Because this invention adopts the concept of a tube-through module, the structure of the composite module can avoid the problem of target plate material falling off due to local welding defects. At the same time, due to the concept of a flat plate module, the temperature distribution of the plasma material is more uniform. Under the action of the fusion reactor cyclic heat load, the huge tensile stress generated in the middle of the tungsten material of the target plate during the cooling stage shifts to both sides, and the maximum value is greatly reduced. The plastic deformation generated during the heat flow loading process is reduced, thereby predicting that the fatigue life of the tungsten material can be improved. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 A three-dimensional structural diagram of a divertor cooling target plate structure provided by the present invention;

[0027] Figure 2This is a front view schematic diagram of a divertor cooling target plate structure provided by the present invention;

[0028] Figure 3 This is a schematic diagram of an ITER tube-passing module in the prior art;

[0029] Figure 4 Schematic diagrams of four composite modules with different rounded corners provided by the present invention;

[0030] Figure 5 This is a temperature distribution diagram of the ITER tube-passing module 10 seconds after the heating ends.

[0031] Figure 6 The temperature distribution of the composite module is shown 10 seconds after the heating process ends.

[0032] Figure 7 Stress distribution diagram of the ITER tube-through module in the direction perpendicular to the axial direction of the water-cooled pipe at 20 seconds after the end of cooling;

[0033] Figure 8 Stress distribution diagram of the composite module in the direction perpendicular to the axial direction of the water cooling pipe at 20 seconds after the end of cooling;

[0034] Figure 9 This is a diagram showing the plastic deformation distribution of the plasma-facing components in the ITER tube-passing module 10 seconds after the heating process ends.

[0035] Figure 10 The distribution of plastic deformation of the plasma-facing component in the composite module is shown 10 seconds after the heating ends.

[0036] Figure 11 This is a diagram showing the plastic deformation distribution of the transition layer in the ITER tube-piercing module 10 seconds after the heating process ends.

[0037] Figure 12 This is a diagram showing the plastic deformation distribution of the transition layer in the composite module 10 seconds after the heating process ends.

[0038] The attached diagram shows the markings and corresponding component names:

[0039] 1-Composite module, 11-Plasma-oriented component, 12-Transition layer, 2-Cooling pipe, 3-Coolant, 4-Break plate, 5-Gap plate. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0041] Example 1

[0042] This embodiment 1 provides a fusion reactor divertor tube-plate composite module, such as... Figure 1 , Figure 2 and Figure 4 As shown, the composite module 1 combines the high heat exchange efficiency of the flat module with the safety of the tube module. It includes a plasma-facing component 11 and a transition layer 12. The plasma-facing component 11 is located on the periphery and is used to contact the plasma. A through hole matching the transition layer 12 is provided in the plasma-facing component 11. The transition layer 12 is metallurgically connected in the through hole. A cooling pipe 2 is metallurgically connected in the transition layer 12. Coolant flows through the cooling pipe 2 to remove the heat caused by fusion. The outer shape of the transition layer 12 is a U-shaped structure with a flat top and a round bottom, and the inner shape of the transition layer 12 is a circular structure. By effectively increasing the ratio of the transition layer to the plasma-facing component, the overall thermal conductivity of the composite module is improved, and the stress and strain concentration problems of the composite module are alleviated.

[0043] Specifically, please refer to Figure 2 and Figure 4 As shown, the plasma-facing component 11 has a cuboid structure with a width of 22mm to 35mm, a height of 25mm to 35mm, and a thickness of 8mm to 15mm. The maximum distance between the inner wall of the through hole of the plasma-facing component 11 and the outer surface of the plasma-facing component 11 facing the fusion center is 5mm to 8mm, which can effectively reduce the thermal stress concentration caused by uneven heat distribution and improve the reliability of the module structure.

[0044] Meanwhile, the plasma-facing component 11 is made of tungsten, the transition layer 12 is made of oxygen-free copper OFHC, and the cooling pipe 2 is made of zirconium-chromium-copper alloy CuCrZr. A certain heat flux density acts on the surface of the divertor, and the energy from the target plate is finally carried away by the coolant 3 in the pipe after passing through the heat conduction process of the three structural materials.

[0045] For details, please refer to [link / reference]. Figure 2 and Figure 4 As shown, the upper U-shaped plane of the transition layer 12 faces the fusion center direction, and the upper U-shaped plane and the lower U-shaped arc surface of the transition layer 12 are rounded, with a rounding radius of 0mm to 8mm. In this embodiment, for example... Figure 4As shown, from left to right, the first one is the upper end rounded corner of the transition layer 12 with a radius of 5mm, the second one is the upper end rounded corner of the transition layer 12 with a radius of 3mm, the third one is the upper end rounded corner of the transition layer 12 with a radius of 1mm, and the fourth one is the structure without rounding treatment. The rounded corner structure between the transition layer 12 and the U-shaped upper plane and U-shaped lower arc surface facing the plasma component 11 can more uniformly and effectively extract energy from the plasma.

[0046] To illustrate the feasibility of this invention in detail, a comparison will be made below between a composite module with a 3mm radius rounded corner at the upper end of the transition layer 12 and a traditional ITER tube-insertion structure. Figures 3-12 As shown, transient thermo-structural coupling analysis and comparison were performed using the finite element analysis software ANSYS. A 20 MW / m² load was applied to the plasma-facing surface of plasma component 11 for 10 seconds. 2 After the heat flow, the device was cooled to room temperature for 10 seconds (simulating the heat flow loading condition inside a fusion reactor). The inner wall of the cooling tube 2 was subjected to a convective heat transfer boundary condition with a water temperature of 70℃ and a convective heat transfer coefficient of 100kW / (m²·℃) (consistent with the convective heat transfer coefficient of the ITER tube divertor). Fixed constraints (i.e., constraints on movement in the x, y, and z directions) were applied to the bottom facing the plasma component 11. Under the same thermal-structural boundary conditions, by comparing the temperature, stress, and strain of the two structures, the technical effects of the structure of this invention can be obtained:

[0047] 1) By Figure 5 and Figure 6 As shown: at the end of heating (10s), the highest temperature of the ITER tube-through module is located at the two edges facing the plasma surface, with a maximum temperature of 2108℃. The temperature at the middle position facing the plasma surface is 1845℃, and the top temperature of cooling pipe 2 is 484℃. In contrast, the highest temperature of the composite module of this invention is located at the two edges facing the plasma surface, with a maximum temperature of 1624℃. The temperature at the middle position facing the plasma surface is 1434℃, and the top temperature of cooling pipe 2 is 416℃. Therefore, the overall temperature of the composite module of this invention is lower than that of the ITER tube-through module, and the temperature gradient from the plasma surface to cooling pipe 2 is also smaller, which is beneficial to reducing thermal stress.

[0048] 2) By Figure 7 and Figure 8As shown, at the end of cooling (20s), a huge tensile stress in the x-direction will be generated near the plasma-facing surface of the module. This tensile stress can easily cause the initiation and propagation of longitudinal cracks on the top of the plasma-facing component 11. The maximum tensile stress on the plasma-facing surface of the ITER tube-through module is 884MPa, located at the edge of the middle region of the surface; while the maximum tensile stress on the plasma-facing surface of the composite module of this invention is 198MPa, and its position is moved to both outer directions compared to the ITER module, thus alleviating the stress concentration phenomenon.

[0049] 3) By Figure 9 and Figure 10 It can be seen that at the end of heating (10s), the maximum plastic deformation of the plasma-facing component 11 in the ITER tube-piercing module is 0.0048, located in the middle region of the plasma-facing surface; while the maximum plastic deformation of the composite module of this invention is 0.00067, which is an order of magnitude lower than that of the ITER tube-piercing module, and its distribution is similar to... Figure 8 The tensile stress distribution is similar, but the position is moved to the two outer directions compared to the ITER module, which alleviates plastic deformation.

[0050] 4) By Figure 11 and Figure 12 As shown: at the end of heating (10s), the maximum value of plastic deformation of the transition layer 12 in the ITER tube-passing module is 0.109, located at the top of the outer wall of the transition layer 12; while the maximum value of plastic deformation of the composite module of the present invention is 0.078, located at the top of the outer wall of the transition layer 12, and the plastic deformation of the transition layer 12 does not increase.

[0051] Based on the above calculations, when the composite module of the present invention faces the heat from the impact of the core plasma, the heat is transferred to the cooling pipe 2 through the thermal conductivity of the solid metal material, and then the heat is carried away by the convective heat transfer between the inner wall of the cooling pipe 2 and the coolant 3 inside. Since the outer shape of the transition layer 12 of the composite module of the present invention is a U-shaped structure with a flat top and a round bottom, and the inner side is a circular structure, while the inner and outer shapes of the transition layer 12 of the non-ITER tube-through module are both circular, when the thermal conductivity of copper is much higher than that of tungsten, by appropriately increasing the proportion of copper and tungsten, the maximum temperature of the module can be effectively reduced and the temperature distribution on the plasma-facing surface can be homogenized. This achieves the purpose of reducing the stress level in the high-temperature area of ​​the upper part of the plasma-facing component 11 and reducing the plastic deformation of the plasma-facing component 11, while also improving the lifespan of the module.

[0052] Example 2

[0053] This embodiment 2 provides a cooling target plate structure, such as Figure 1As shown, a fusion reactor divertor tube-plate composite module 1 from one of the multiple embodiments 1 is used. A gap is designed between adjacent composite modules 1, and a gasket 5 is placed in the gap. The composite modules 1 are then connected in series along the axial direction. Cooling pipes 2 pass through the through holes of each composite module 1 to connect the composite modules 1, so that the above composite module 1 becomes a single-channel cooling module. A baffle 4 to enhance heat exchange efficiency is installed inside the cooling pipe 2 in each single-channel cooling module. The baffle 4 has a spiral structure and its outline is circular. Finally, multiple single-channel cooling modules are connected in parallel to form a whole structure.

[0054] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fusion reactor divertor tube-plate composite module, characterized in that, The system includes a composite module (1), which includes a plasma-facing component (11) and a transition layer (12). The plasma-facing component (11) is located on the periphery and is used to contact the plasma. The plasma-facing component (11) has a through hole that matches the transition layer (12). The transition layer (12) is metallurgically connected to the through hole. A cooling pipe (2) is metallurgically connected to the transition layer (12). Coolant (3) flows through the cooling pipe (2) to remove the heat caused by fusion. The outer side of the transition layer (12) has a U-shaped structure with a flat top and a round bottom, and the inner side of the transition layer (12) has a circular structure.

2. The fusion reactor divertor tube-plate composite module according to claim 1, characterized in that, The U-shaped upper plane of the transition layer (12) faces the fusion center.

3. The fusion reactor divertor tube-plate composite module according to claim 1, characterized in that, The plasma-facing component (11) has a cuboid structure.

4. A fusion reactor divertor tube-plate composite module according to claim 3, characterized in that, The width of the plasma-facing component (11) is 22mm to 35mm, the height of the plasma-facing component (11) is 25mm to 35mm, and the thickness of the plasma-facing component (11) is 8mm to 15mm.

5. A fusion reactor divertor tube-plate composite module according to claim 1, characterized in that, The transition layer (12) has a rounded corner between its U-shaped upper surface and U-shaped lower arc surface.

6. A fusion reactor divertor tube-plate composite module according to claim 5, characterized in that, The radius of the rounded corner between the upper U-shaped surface and the lower U-shaped arc surface of the transition layer (12) is 0mm to 8mm.

7. A fusion reactor divertor tube-plate composite module according to any one of claims 1-6, characterized in that, The plasma-facing component (11) is made of tungsten, the transition layer (12) is made of oxygen-free copper (OFHC), and the cooling pipe (2) is made of zirconium-chromium-copper alloy (CuCrZr).

8. A fusion reactor divertor tube-plate composite module according to any one of claims 1-6, characterized in that, The maximum distance between the inner wall of the through hole and the outer surface of the plasma-facing component (11) facing the fusion center is 5 mm to 8 mm.

9. A divertor cooling target plate structure, characterized in that, A fusion reactor divertor tube-plate composite module, as described in any one of claims 1-6, is connected in series along the axial direction to form a single-channel cooling module, and multiple such single-channel cooling modules are connected in parallel to form a structural whole.

10. The divertor cooling target plate structure according to claim 9, characterized in that, Each of the single-channel cooling modules has a baffle plate (4) that enhances heat exchange efficiency installed inside the cooling pipe (2).

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