Shielding structure for a tokamak device and method of manufacture

Abstract

The application relates to the technical field of layered products, and discloses a protective structure for a tokamak device and a manufacturing method, the protective structure comprising a first structural member, a second structural member, a third structural member and a fourth structural member arranged in sequence, the surface roughness Ra of the side surface of the first structural member facing the plasma is less than or equal to 1.6 micrometers, the second structural member is a porous member, the third structural member is configured to change at least one of the pressure, the temperature, the phase state, the component or the flow state of a working medium, so that the working medium exhibits different effective thermal physical properties, thereby realizing the switching of the third structural member between a heat conduction mode and a heat buffering mode; in the heat conduction mode, the third structural member transfers the heat on the second structural member to the fourth structural member; in the heat buffering mode, the third structural member weakens the heat transferred thereto; and the fourth structural member is filled with a cooling medium. The protective performance of the protective structure is effectively guaranteed, and the protection effect of the protective structure on the core structure of the tokamak device is improved.

Description

Technical Field

[0001] This invention relates to the field of layered product technology, and in particular to a protective structure for a tokamak device and a method for manufacturing it. Background Technology

[0002] A tokamak device is a device that uses a strong magnetic field to confine high-temperature plasma at hundreds of millions of degrees Celsius within a toroidal vacuum chamber to achieve controlled nuclear fusion. During actual operation, the tokamak device experiences alternating periods of continuous plasma confinement and transient thermal shocks. This results in a complex thermal environment where the tokamak device is subjected to both steady-state continuous heat generation and transient high-temperature shocks. Consequently, the core structures of the tokamak device facing the plasma (such as the first wall and divertor) are susceptible to thermal damage, making them prone to thermal deformation cracking, continuous decay of load-bearing and heat dissipation capabilities, and a significant reduction in lifespan. In some cases, this can even lead to the failure of the tokamak device.

[0003] To address the aforementioned issues, a protective structure is typically installed on the exterior of the first wall, divertor, and other components, specifically on the side facing the high-temperature plasma. This protective structure is designed to withstand the fusion heat load and the bombardment of escaped electrons, thereby reducing the thermal damage to the first wall, divertor, and other components caused by the plasma.

[0004] However, the protective performance of existing protective structures is poor, resulting in inadequate protection of the core structure of the tokamak device. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a protective structure for a tokamak device, which effectively ensures the protective performance of the protective structure, improves the protective effect of the protective structure on the core structure of the tokamak device, and solves the technical problem of poor protective performance of existing protective structures.

[0006] The present invention also aims to provide a method for manufacturing a protective structure for a tokamak device.

[0007] According to an embodiment of the present invention, a protective structure for a tokamak device includes a first structural member, a second structural member, a third structural member, and a fourth structural member arranged sequentially; wherein, the first structural member is adapted to be oriented towards a plasma, and the surface roughness Ra of the side of the first structural member facing the plasma is ≤1.6μm; the second structural member is formed as a porous component; a channel is formed within the third structural member, the channel being filled with a working medium; the third structural member is configured to allow the working medium to exhibit different effective thermal properties by changing at least one of the pressure, temperature, phase, composition, or flow state of the working medium, thereby enabling the third structural member to switch between a heat conduction mode and a heat buffering mode; in the heat conduction mode, the third structural member is used to transfer heat from the second structural member to the fourth structural member; in the heat buffering mode, the third structural member is used to reduce the heat transferred thereto; a receiving cavity is formed within the fourth structural member, the receiving cavity being adapted to be filled with a cooling medium.

[0008] According to the embodiments of the present invention, the protection of a tokamak device, through the above-described arrangement, can effectively ensure the protective performance of the protective structure and improve the protective effect of the protective structure on the core structure of the tokamak device.

[0009] In some embodiments, the third structural member is provided with a plurality of channels, which are arranged at intervals; or, the plurality of channels are arranged in parallel; or, at least two of the channels intersect.

[0010] In some embodiments, the channel is a straight channel or the channel has at least one bend.

[0011] In some embodiments, the channel has an inlet adapted to connect to an external storage unit adapted to store the working medium, and a control valve is provided at the inlet for changing the pressure or flow rate of the working medium.

[0012] In some embodiments, the working medium is at least one of the following materials: supercritical fluid, near-critical fluid, phase change thermal storage material, high heat capacity liquid, liquid metal, gas-liquid two-phase working fluid, molten salt, or porous endothermic medium.

[0013] In some embodiments, the first structural component is a pure tungsten component, a tungsten alloy component, a tungsten-copper composite component, a tungsten-rhenium alloy component, or a tungsten-tantalum alloy component; and / or, a high-temperature resistant component is provided on the side of the first structural component facing the plasma, the high-temperature resistant component being a carbide component, a nitride component, or a boride component.

[0014] In some embodiments, the second structural member is a high-porosity tungsten alloy skeleton; and / or, the fourth structural member is a chromium-zirconium-copper member, the fourth structural member is provided with a plurality of cooling pipes, the receiving cavity is formed in the cooling pipes, and the cooling medium is water.

[0015] In some embodiments, the first structural member, the second structural member, and the third structural member are integrally formed parts or separate parts, and the fourth structural member is welded to the third structural member.

[0016] In some embodiments, the protective structure for the tokamak device further includes a gas generator disposed on the side of the first structure facing the plasma, the gas generator being used to emit a gas that absorbs heat; wherein the gas generator is used to emit at least one of deuterium, helium, and neon.

[0017] In some embodiments, the protective structure is provided on at least one of the first wall of the tokamak device, the divertor target plate of the tokamak device, the limiter of the tokamak device, the protective tile of the tokamak device, the diagnostic window of the tokamak device, and the inner wall of the vacuum chamber of the tokamak device.

[0018] According to an embodiment of the present invention, a method for manufacturing a protective structure for a tokamak device, wherein the protective structure for the tokamak device is the aforementioned protective structure, the manufacturing method includes the following steps: The first structural component, the second structural component, and the third structural component are integrally manufactured using additive manufacturing technology, and the fourth structural component is welded to the third structural component. or, Prepare the second structural component; Using physical vapor deposition or chemical vapor deposition, a tungsten plate is first welded onto the surface of the second structural component, and a tungsten coating is deposited on the tungsten plate. The tungsten plate and the tungsten coating together form the first structural component. The third structural component and the fourth structural component are prepared separately, and the second structural component, the third structural component and the fourth structural component are welded together in sequence.

[0019] The manufacturing method of the protective structure for a tokamak device according to embodiments of the present invention can reduce the manufacturing difficulty of the protective structure and facilitate ensuring the protective performance of the protective structure.

[0020] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a protective structure for a tokamak device according to some embodiments of the present invention; Figure 2 These are step diagrams illustrating a method for manufacturing a protective structure for a tokamak device according to some embodiments of the present invention; Figure 3 The diagram shows the steps of a method for manufacturing a protective structure for a tokamak device according to other embodiments of the present invention.

[0022] Figure label: 1000. Protective structure; 100. First structural component; 200. Second structural component; 300. Third structural component; 310. Channel; 400, Fourth structural component; 410, Receiving cavity. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] It should be noted that in the transient conditions faced by tokamak devices, escape electrons cause significant damage to the first wall material. According to the latest research, escape electrons exhibit both fast loading (approximately 1 ms) and slow loading (approximately 100 ms). Fast loading refers to the escape electrons releasing their kinetic energy to the first wall almost instantaneously within an extremely short time (one-thousandth of a second), while slow loading refers to the relatively slow energy release process of the escape electrons, lasting approximately 100 milliseconds (one-tenth of a second), before gradually transferring energy to the first wall. These two types of energy loading produce very different consequences. Fast loading causes intense vaporization cooling on the surface of the first wall material, resulting in a "non-monotonic temperature distribution" inside the first wall (the highest temperature is located at a submicron depth below the surface). This can induce extremely high internal stress, easily leading to the explosion of the first wall material and the splashing of solid debris. Slow loading, due to the long-term energy deposition, after a period of heat conduction, will cause extreme heat to be conducted to the bottom of the first wall, easily triggering an accident.

[0026] To solve the above problems, such as Figure 1 As shown, this application proposes a protective structure 1000 for a tokamak device.

[0027] The protective structure 1000 for a tokamak device according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0028] like Figure 1 As shown, a protective structure 1000 for a tokamak device according to an embodiment of the present invention includes: a first structural member 100, a second structural member 200, a third structural member 300 and a fourth structural member 400 arranged in sequence.

[0029] The first structural component 100 is adapted to be positioned facing the plasma (not shown in the figure), and the surface roughness Ra of the plasma-facing side of the first structural component 100 is ≤1.6μm. This ensures the smoothness of the plasma-facing side of the first structural component 100, making it dense and smooth. A dense and smooth surface reduces the effective specific surface area of ​​the plasma-facing side of the first structural component 100, reducing the exposure of surface defects and pores. This not only reduces the risk of hydrogen isotope retention but also reduces the risk of dust or particle shedding, preventing a decrease in the tensile strength and toughness of the first structural component 100, ensuring the structural strength of the first structural component 100, and thus preventing accelerated aging and failure of the first structural component 100, thereby extending the service life of the first structural component 100.

[0030] In some examples, the surface roughness of the side of the first structural member 100 facing the plasma can be Ra≤0.8μm.

[0031] In other examples, the surface roughness of the side of the first structural member 100 facing the plasma can be Ra≤0.4μm. Through the above settings, the side of the first structural member 100 facing the plasma is further formed into a denser and smoother surface.

[0032] like Figure 1 As shown, the second structural member 200 is formed as a porous component. When an escaped electron is generated and strikes the first structural member 100 in a fast-loading manner, the porous structure of the second structural member 200 can act as a physical pressure relief channel to absorb and buffer the vapor pressure and thermal stress generated by the escaped electron impacting the first structural member 100. This reduces the risk of material cracking, spalling, and debris ejection of the protective structure 1000, thereby preventing the first structural member 100 from being blown away due to excessive vapor pressure inside the protective structure 1000, and ensuring the protective performance of the protective structure 1000.

[0033] In summary, by setting the surface roughness of the side of the first structural member 100 facing the plasma to Ra≤1.6μm and setting the second structural member 200 to be a porous component, this application can avoid the shedding of tiny solid particles and the injection of impurities and dust caused by setting the entire protective structure to a porous material in the prior art during steady-state operation of the tokamak device. At the same time, it can also effectively absorb and buffer the vapor pressure and thermal stress generated by the rapid loading impact on the first structural member 100, preventing the first structural member 100 from being blown away.

[0034] It should be noted that steady-state operation of a tokamak device refers to the state in which the plasma is stably maintained at high temperature, high density, and high confinement for a long time (from kiloseconds to hours) during the operation of the tokamak device.

[0035] In some embodiments, the thickness of the first structural member 100 can be determined based on the deposition depth of the escape electron energy and the thermal diffusion length, and at least a portion of the second structural member 200 is connected to the side of the first structural member 100 facing away from the plasma. This utilizes the absorption and buffering capabilities of the porous second structural member 200 to reduce the vaporization pressure of the subsurface layer (at the second structural member 200) in the protective structure 1000, thereby reducing the impact of the vaporization pressure on the first structural member 100 and other components of the protective structure 1000.

[0036] like Figure 1As shown, a channel 310 is formed within the third structural member 300, and the channel 310 is filled with a working medium (not shown in the figure). The third structural member 300 is configured to allow the working medium to exhibit different effective thermal properties by changing at least one of the pressure, temperature, phase, composition, or flow state of the working medium, so as to achieve switching between a heat conduction mode and a heat buffering mode. In the heat conduction mode, the third structural member 300 is used to transfer heat from the second structural member 200 to the fourth structural member 400; in the heat buffering mode, the third structural member 300 is used to reduce the heat transferred thereto.

[0037] It should be noted that effective thermal properties refer to the equivalent thermophysical properties exhibited by the third structural component 300 as a whole on a macroscopic scale. By changing the pressure, temperature, phase, composition, or flow state of the working medium, the distribution, morphology, or movement of the medium within the channel 310 can be altered, thereby causing the third structural component 300 to exhibit different equivalent thermal conductivity, specific heat capacity, or thermal diffusivity, etc. This allows the third structural component 300 to switch between heat conduction mode and heat buffering mode.

[0038] When the third structural component 300 switches to the heat conduction mode, the working medium filled in the channel 310 has good thermal conductivity. Therefore, in the heat conduction mode, the third structural component 300 transfers heat through the metal substrate, the channel wall, and the flow of the working medium to ensure the heat conduction requirements during steady-state operation. When the third structural component 300 switches from the heat conduction mode to the heat buffer mode, it can absorb and cool down the slow-load heat wave of about 100ms to reduce the temperature of the interface transferred from the third structural component 300 to the fourth structural component 400 and prevent the fourth structural component 400 from overheating and failing.

[0039] In some embodiments, the third structural component 300 can be switched from a heat conduction mode to a heat buffer mode by increasing the specific heat capacity of the working medium. Specific heat capacity refers to the amount of heat required to raise the temperature by 1°C per unit mass of a substance. Increasing the specific heat capacity of the working medium in the third structural component 300 means that a unit mass of the medium needs to absorb more heat to raise its temperature. This improves the ability of the third structural component 300 to reduce heat, effectively reducing the temperature transferred from the third structural component 300 to the fourth structural component 400, and ensuring the structural integrity and operational effectiveness of the fourth structural component 400.

[0040] It should be noted that, compared with the traditional technology of increasing the thickness of the protective structure to improve its protective performance, this application sets the third structural component 300 to have a heat conduction mode and a heat buffer mode. This allows the heat absorption and cooling capacity of the working medium in the third structural component 300 to be improved without increasing its thickness. This makes it possible to make the protective structure 1000 thinner and reduce its volume, so as to facilitate the installation of the protective structure 1000.

[0041] like Figure 1 As shown, a receiving cavity 410 is formed within the fourth structural member 400, and the receiving cavity 410 is suitable for being filled with a cooling medium (not shown in the figure). The cooling medium of the fourth structural member 400 can exchange heat with the working medium in the third structural member 300, thereby dissipating the high heat flux of plasma fusion that the protective structure 1000 is subjected to, preventing the first structural member 100, the second structural member 200, and the third structural member 300 from melting at high temperatures, which helps to ensure the protective capability of the protective structure 1000.

[0042] As can be seen from the above structure, the protective structure 1000 for a tokamak device in this embodiment of the invention, by setting a first structural member 100 and setting the surface roughness of the side of the first structural member 100 facing the plasma to Ra≤1.6μm, forms a dense and smooth surface on the side of the first structural member 100 facing the plasma, reducing the exposure of surface defects and pores on the side of the first structural member 100 facing the plasma. This not only reduces the risk of hydrogen isotope retention but also reduces the risk of dust or particle shedding.

[0043] Meanwhile, by forming the second structural component 200 as a porous component, the porous structure of the second structural component 200 can absorb and buffer the vapor pressure and thermal stress generated by the collision of escaped electrons with the first structural component 100, preventing the first structural component 100 from being blown away due to excessive vapor pressure inside the protective structure 1000, thus effectively improving the protective performance of the protective structure 1000; by setting the third structural component 300, the switching between the heat conduction mode and the heat buffering mode of the third structural component 300 can not only ensure the heat conduction requirements of the tokamak device during steady-state operation, but also absorb and cool the slow-load heat wave of about 100ms, thereby reducing the temperature of the interface from the third structural component 300 to the fourth structural component 400, and preventing the fourth structural component 400 from overheating and failing; by setting the fourth structural component 400, the high heat flux of plasma fusion that the protective structure 1000 bears can be effectively discharged and dissipated.

[0044] Understandably, compared with the prior art, the protective structure 1000 of this application has high protective performance, can solve the heat loading problem caused by escaping electrons, and can also achieve both steady-state heat dissipation capability and thermal insulation protection of the fourth structural component 400.

[0045] In the description of this invention, features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include one or more of these features, used to distinguish and describe features, without any order or emphasis.

[0046] In some embodiments, the pressure of the working medium can be controlled by valve regulation (such as a pressurizing or venting valve), mechanical compression (such as a plunger pump), or by heating or cooling the working medium within the heating or cooling channel 310.

[0047] Optionally, the temperature of the working medium can be adjusted by an external temperature control unit, which includes at least one of a heater, cooler, heat exchanger, preheating tank, or temperature control circulation loop. By preheating, cooling, or circulating heat exchange of the working medium entering the channel 310, the temperature of the working medium in the channel 310 can be changed, allowing it to switch between a steady-state heat conduction mode and a transient heat buffer mode.

[0048] Optionally, the phase state of the working medium can be triggered by changing the pressure (inducing gas-liquid phase change by increasing or decreasing the pressure), changing the temperature (achieving solid-liquid-gas conversion by heating or cooling), or applying external fields such as electric fields or magnetic fields to trigger a controllable structural phase change.

[0049] Optionally, the composition of the working medium can be dynamically adjusted by regulating the flow ratio of different raw materials (e.g., adjusting the component ratio in a non-azeotropic working medium), or by using bypass control, physical separation, or other technologies to actively change the actual circulating composition of the medium in channel 310.

[0050] Optionally, the flow state of the working medium can be changed by at least one of a pump, compressor, pulse valve, throttle valve, diverter valve, bypass valve or pressure regulating device. By adjusting the flow rate, velocity, pressure difference, pulse frequency or flow path of the working medium, the working medium can be switched between different flow states such as static, low-speed flow, high-speed flow, pulsed flow, laminar flow, turbulent flow, single-phase flow or two-phase flow, thereby changing the thermal conductivity or thermal buffering capacity of the third structural component 300.

[0051] In specific examples, when the working medium is a near-critical or supercritical fluid, it can be brought into a near-critical or supercritical high heat capacity condition by adjusting the pressure and temperature; when the working medium is a phase change thermal storage material or a gas-liquid two-phase working fluid, it can be made to melt, solidify, vaporize, condense, or undergo gas-liquid two-phase changes by adjusting the temperature, temperature, or pressure; when the working medium is a liquid metal, molten salt, or a high heat capacity liquid, its effective heat exchange capacity can be changed by adjusting the flow rate, temperature, or external circulation state.

[0052] In summary, the third structural component 300 can switch between heat conduction mode and heat buffer mode by changing at least one of the pressure, temperature, flow rate, flow state or thermal properties of the working medium through the cooperation of external control valve, pumping unit, pressure regulating unit, temperature control unit and working medium storage unit.

[0053] In some embodiments, such as Figure 1 As shown, the third structural component 300 is provided with multiple channels 310, which are arranged at intervals. The multiple channels 310 can increase the filling volume of the working medium and ensure the thermal conductivity of the third structural component 300.

[0054] In some embodiments, such as Figure 1 As shown, multiple channels 310 are arranged in parallel. This gives the third structural component 300 advantages such as simple structure, low pressure drop, and ease of manufacturing and sealing.

[0055] In some embodiments, at least two channels 310 intersect (not shown in the example figure). That is, it is not limited to arranging multiple channels 310 in parallel, but at least two channels 310 can also be arranged to intersect, in order to increase the heat exchange area, extend the residence time of the working medium, and improve temperature uniformity.

[0056] In specific examples, multiple channels 310 are arranged at intervals, forming parallel channels; or, multiple channels 310 are arranged in parallel, forming independent channels in different zones; or, at least two channels 310 intersect, forming grid channels or tree-like branching channels.

[0057] In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0058] In some embodiments, channel 310 is a straight channel or channel 310 has at least one bend. It should be noted that channel 310 having at least one bend means that channel 310 may have one bend, or channel 310 may have two, three or more bends. Through the above configuration, the filling volume of the working medium can be increased, ensuring the thermal conductivity of the third structural component 300.

[0059] In a specific example, when the channel 310 has at least one bend, the channel 310 is formed as a serpentine channel.

[0060] It should be noted that when channel 310 is formed as a serpentine channel, a grid channel, or a tree-shaped diversion channel, it can increase the heat exchange area of ​​the working medium, extend the residence time of the working medium, and improve the temperature uniformity of the working medium.

[0061] In some examples, channel 310 is formed as a parallel straight channel. Compared with serpentine channels, grid channels, etc., the parallel straight channel does not have bends or corners, which makes the parallel straight channel not only simple in structure and with a small pressure drop, but also easier to manufacture and seal, thus making it easier to reduce the processing difficulty of the third structural component 300.

[0062] Pressure drop refers to the difference between the inlet pressure and the outlet pressure when a fluid (gas / liquid) flows through a channel, pipe, cavity, or flow path, i.e., pressure loss. Since parallel straight channels do not have bends or corners, the working medium in parallel straight channels can avoid the pressure loss due to bends, diameter changes, etc., so the difference between the inlet pressure and the outlet pressure of parallel straight channels changes little, and therefore the pressure drop of parallel straight channels is small.

[0063] In some embodiments, channel 310 has an inlet (not shown) adapted to connect to an external storage unit (not shown), the external storage unit being adapted to store the working medium, and a control valve (not shown) provided at the inlet for changing the pressure or flow rate of the working medium. By providing an inlet to channel 310 and connecting the inlet to the external storage unit, the difficulty of the working medium from the external storage unit entering channel 310 can be reduced.

[0064] Meanwhile, by setting a control valve at the inlet, the pressure or flow rate of the working medium can be changed by adjusting the opening of the control valve, thereby increasing the specific heat capacity of the working medium and facilitating the enhancement of the heat absorption and cooling capacity of the working medium in the third structural component 300.

[0065] It should be noted that, under normal circumstances, the pressure of the working medium in channel 310 is increased by controlling the valve. When the pressure approaches the critical point, and the pressure and temperature of the working medium are close to the critical value, the specific heat capacity will show a sharp peak, which can be several times or even tens of times higher than at room temperature. This increases the specific heat capacity of the working medium, which facilitates the absorption of heat transferred from the second structural component 200 to the third structural component 300 by the working medium. This weakens the slow-load heat wave that lasts up to 100ms and effectively cools it down, resulting in a low interface temperature of the fourth structural component 400 and effectively protecting the structural strength of the fourth structural component 400.

[0066] In a specific example, the control valve is formed as a high-pressure piezoelectric crystal pulse control valve. The high-pressure piezoelectric crystal pulse control valve can control the pressure of the working medium, so that the working medium in the channel 310 has the following states: entering or maintaining a near-critical or supercritical high heat capacity condition, or entering a phase change heat absorption, high heat capacity heat absorption, or a two-phase heat exchange state. All of the above states can improve the specific heat capacity of the working medium.

[0067] In some embodiments, the working medium is at least one of the following materials: supercritical fluid, near-critical fluid, phase change thermal storage material, high heat capacity liquid, liquid metal, gas-liquid two-phase working fluid, molten salt, or porous endothermic medium. This allows the third structural member 300 to be configured to switch between a heat conduction mode and a heat buffering mode by changing at least one of the pressure, temperature, flow rate, flow state, or thermal properties of the working medium.

[0068] In this specific example, the working medium is carbon dioxide.

[0069] In some embodiments, the first structural component 100 is a pure tungsten component, a tungsten alloy component, a tungsten-copper composite component, a tungsten-rhenium alloy component, or a tungsten-tantalum alloy component. Because tungsten has a high melting point, strong thermal shock resistance, good thermal conductivity, and stable chemical properties, regardless of whether the first structural component 100 is made of pure tungsten or a composite material of tungsten and other metals, it can provide extremely strong protection against plasma, fulfilling its function as the first effective barrier of the first wall, the protective structure 1000 of the divertor directly facing the plasma, reducing tritium retention and minimizing particle shedding.

[0070] In some embodiments, a high-temperature resistant component is provided on the plasma-facing side of the first structural member 100. The high-temperature resistant component is a carbide, nitride, or boride component. This gives the plasma-facing side of the first structural member 100 high-temperature resistant properties, thereby reducing the thermal damage to the first structural member 100 from the high-temperature radiation of the plasma and ensuring the protective capability of the first structural member 100.

[0071] In a specific example, the first structural component 100 is made of tungsten. Carbide, nitride or boride materials can be sprayed onto the side of the first structural component 100 facing the plasma to realize the setting of a high temperature resistant component on the side of the first structural component 100 facing the plasma, thereby enhancing the high temperature resistance of the first structural component 100.

[0072] In some embodiments, the second structural member 200 is a high-porosity tungsten alloy skeleton. This achieves the purpose of forming the second structural member 200 as a porous component, effectively absorbing and buffering the vapor pressure generated by the impact of escaping electrons on the first structural member 100, preventing an internal explosion of the protective structure 1000 from blowing the first structural member 100 away, and ensuring the effective protective capability of the protective structure 1000.

[0073] In some embodiments, the pore morphology of the second structural member 200 may be at least one of the following: interconnected pores, directional pores, gradient pores, honeycomb pores, lattice pores, mesh pores, or regular micropore structures, as long as it satisfies the function of providing pressure relief, buffering, and explosion resistance under transient thermal shock.

[0074] In other embodiments, the second structural member 200 is made of foamed tungsten, tungsten fiber felt or other refractory metal porous structures.

[0075] In some embodiments, the fourth structural member 400 is a chromium-zirconium copper component, and the fourth structural member 400 is provided with multiple cooling pipes, forming a receiving cavity 410 inside the cooling pipes, with water as the cooling medium. Because chromium-zirconium copper has characteristics such as high thermal conductivity, high mechanical strength, high temperature resistance, and creep resistance, by using a chromium-zirconium copper component for the fourth structural member 400, it is convenient for the fourth structural member 400 to quickly dissipate heat from the third structural member 300, resulting in high temperature control efficiency of the protective structure 1000.

[0076] Meanwhile, by providing multiple cooling pipes within the fourth structural component 400, forming a receiving cavity 410 within the cooling pipes, and using water as the cooling medium, the multiple cooling pipes can increase the volume of the receiving cavity 410, thereby increasing the capacity of the cooling medium and further enhancing the cooling effect of the cooling medium, thus achieving the enhanced cooling and heat dissipation capacity of the protective structure 1000.

[0077] In other embodiments, the fourth structural component 400 may be made of other copper alloys, tungsten copper composites, molybdenum copper composites, low-activation steel or other materials suitable for the cooling structure of fusion devices; the cooling method is not limited to water cooling, but may also be helium cooling, liquid metal cooling, molten salt cooling, heat pipe cooling or a combination of cooling methods.

[0078] Among them, heat pipe cooling is a passive, ultra-high thermal conductivity heat transfer element that uses internal working fluid phase change and capillary reflux circulation to quickly move heat from one end to the other. Its equivalent thermal conductivity is hundreds to thousands of times higher than that of copper. Composite cooling can be understood as the superposition and combination of multiple cooling structures to take into account high heat flux, uniform temperature, and long-term heat dissipation. Examples include heat pipes and water cooling channels embedded in chromium-zirconium-copper substrates, and liquid metal heat pipes embedded in chromium-zirconium-copper substrates with helium-assisted cooling.

[0079] In some embodiments, the first structural member 100, the second structural member 200, and the third structural member 300 are integrally formed parts or separate parts, and the fourth structural member 400 is welded to the third structural member 300. This forms the protective structure 1000, reduces the forming difficulty of the protective structure 1000, and helps to ensure the structural strength of the protective structure 1000.

[0080] When the first structural component 100, the second structural component 200, and the third structural component 300 are integrally formed, the assembly error of the first structural component 100, the second structural component 200, and the third structural component 300 can be reduced, and the absence of splicing gaps can be achieved. This results in minimal thermal resistance at the interface between the first structural component 100, the second structural component 200, and the third structural component 300, leading to smoother heat conduction and suitability for high heat load scenarios. When the first structural component 100, the second structural component 200, and the third structural component 300 are processed separately, each component can be manufactured individually. This not only simplifies the processing technology but also increases the yield rate. After the first structural component 100, the second structural component 200, and the third structural component 300 are processed separately, they can be welded together to form an integral structure, facilitating the subsequent welding connection between the fourth structural component 400 and the third structural component 300.

[0081] In some embodiments, when the first structural member 100, the second structural member 200, and the third structural member 300 are processed separately, the first structural member 100 and the second structural member 200, the second structural member 200 and the third structural member 300, and the third structural member 300 and the fourth structural member 400 can be connected by welding methods such as diffusion welding or vacuum brazing to form a protective structure 1000.

[0082] In some embodiments, the protective structure 1000 for a tokamak device further includes a gas generator (not shown) disposed on the side of the first structural member 100 facing the plasma. The gas generator emits a gas that absorbs heat. This intercepts and dissipates some of the electron beam energy of the escaping electrons, reducing the actual thermal load borne by the plasma-facing side of the first structural member 100.

[0083] In some embodiments, the gas generator is used to emit at least one of deuterium, helium, and neon. It can rapidly form a high-density gas cloud, plasma cloud, or particle cloud in a short time to absorb, scatter, or expand the energy deposition range of the escaping electron beam and transient heat flow in advance, thereby reducing the actual thermal load on the surface of the first structural member 100, and reducing the local energy density of the escaping electron beam when it reaches the first structural member 100 and consuming its kinetic energy.

[0084] In other embodiments, the gas generator may spray liquid deuterium, or it may spray argon, low-Z powder, droplets, ice pellets, aerogel particles, or other sacrificial shielding media, wherein low-Z refers to elements with low atomic numbers, such as lithium (Li), beryllium (Be), or carbon (C).

[0085] In some embodiments, the gas generator can emit heat-absorbing gas through laser triggering, electric arc, microwave, radio frequency, plasma gun, pulsed gas valve or high-speed jet to form a shielding cloud.

[0086] In some embodiments, a diagnostic system (not shown in the figure) can be used to detect precursors of rupture and escape electron beam formation. The diagnostic system can be at least one of hard X-ray signal, magnetic probe signal, infrared thermography signal, loop voltage anomaly signal, or machine learning prediction system. By using the above-mentioned diagnostic system, it is convenient to detect the parameter state of the plasma. If the parameter state of the plasma is different from the normal parameters, the diagnostic system issues an early warning signal for the formation of rupture and escape electron beam. At this time, the gas generator can receive the early warning signal and turn on, emitting at least one of deuterium, helium, and neon.

[0087] In some embodiments, the gas generators include multiple gas generators, and the diagnostic system can control all gas generators simultaneously, or it can independently control different gas generators in separate zones.

[0088] In some embodiments, this application can implement a multi-timescale collaborative protection control method for a tokamak device. This method includes a steady-state operation phase, a rupture warning phase, a fast-loading depressurization buffer phase for escape electrons, and a slow-loading heat flow cutoff phase for escape electrons. In the steady-state operation phase, the third structural component 300 is in heat-conducting mode, and the entire protective structure 1000 maintains efficient heat conduction. In the rupture warning phase, a gas generator is activated, emitting at least one of deuterium, helium, and neon gas to reduce the local energy density of the escape electron beam when it reaches the first structural component 100 and to consume its kinetic energy. In the fast-loading phase for escape electrons, the porous structure of the second structural component 200 absorbs and buffers internal vapor pressure and thermal stress. In the slow-loading phase for escape electrons, the third structural component 300 switches to a heat buffer mode, absorbing or blocking heat transfer to the fourth structural component 400. These phases form a continuous protection chain against thermal shocks at different timescales.

[0089] In some embodiments, the protective structure 1000 is disposed on at least one of the first wall of the tokamak device, the divertor target plate of the tokamak device, the limiter of the tokamak device, the protective tile of the tokamak device, the diagnostic window of the tokamak device, and the inner wall of the vacuum chamber of the tokamak device. This facilitates the protection of at least one of the first wall of the tokamak device, the divertor target plate of the tokamak device, the limiter of the tokamak device, the protective tile of the tokamak device, the diagnostic window of the tokamak device, and the inner wall of the vacuum chamber of the tokamak device using the protective structure 1000, ensuring the normal operation of at least one of the first wall of the tokamak device, the divertor target plate of the tokamak device, the limiter of the tokamak device, the protective tile of the tokamak device, the diagnostic window of the tokamak device, and the inner wall of the vacuum chamber of the tokamak device.

[0090] Of course, in other embodiments, the protective structure 1000 may also be provided on other facing components of the tokamak device that are subjected to high thermal loads or plasma impacts from escaping electrons.

[0091] The following describes a method for manufacturing a protective structure 1000 for a tokamak device according to an embodiment of the present invention, with reference to the accompanying drawings.

[0092] like Figure 2 As shown, a method for manufacturing a protective structure 1000 for a tokamak device according to an embodiment of the present invention includes: S1. The first structural component 100, the second structural component 200 and the third structural component 300 are integrally manufactured using additive manufacturing process, and the fourth structural component 400 is welded to the third structural component 300.

[0093] In the above steps, additive manufacturing can be understood as 3D printing. The first structural component 100, the second structural component 200, and the third structural component 300 are manufactured using 3D printing technology. Then, the fourth structural component 400, which has been processed and shaped, is welded to the third structural component 300 to form a protective structure 1000 for a tokamak device.

[0094] In some embodiments, a three-dimensional model including the first structural member 100, the second structural member 200, and the third structural member 300 is first established based on the heat load, protection requirements, and interface (entrance on the third structural member 300) requirements of the protective structure 1000. Then, selective laser melting (SLM), electron beam melting (EBM), or other additive manufacturing processes suitable for tungsten-based materials (pure tungsten, tungsten alloys, tungsten-copper composites, tungsten-rhenium alloys, or tungsten-tantalum alloys, etc.) are used to form the three-dimensional model of the first structural member 100, the second structural member 200, and the third structural member 300.

[0095] In a specific example, by adjusting the energy density, scanning speed, powder thickness, and scanning path of the 3D printer, the first structural component 100, the second structural component 200, and the third structural component 300 can be formed in the same component.

[0096] In some embodiments, after the first structural component 100, the second structural component 200, and the third structural component 300 are 3D printed, the first structural component 100, the second structural component 200, and the third structural component 300 are subjected to stress-relieving heat treatment, surface finishing, fluid interface processing, vacuuming to inject working medium into the channel 310, and sealing treatment. Then, pressure resistance testing, leakage rate testing, and thermal response calibration are performed to complete the integral processing and molding of the first structural component 100, the second structural component 200, and the third structural component 300.

[0097] In other embodiments, such as Figure 3 As shown, the method for manufacturing the protective structure 1000 for a tokamak device includes: S2. Prepare the second structural component 200; S3. Using physical vapor deposition or chemical vapor deposition, a tungsten plate is first welded onto the surface of the second structural component 200, and a tungsten coating is deposited on the tungsten plate. The tungsten plate and the tungsten coating together form the first structural component 100. S4. Prepare the third structural component 300 and the fourth structural component 400 respectively, and weld the second structural component 200, the third structural component 300 and the fourth structural component 400 in sequence.

[0098] The above steps can reduce the processing difficulty of each component of the first structural component 100, the second structural component 200 and the third structural component 300, and at the same time make the yield of each component of the first structural component 100, the second structural component 200 and the third structural component 300 high.

[0099] In some embodiments, the second structural member 200 may be manufactured by powder metallurgy.

[0100] In a specific example, tungsten powder or tungsten alloy powder is first mixed with a pore-forming agent, and then pressed, degreased, the pore-forming agent is removed, and sintered at high temperature to prepare a second structural component 200 with a porous structure.

[0101] In some embodiments, high-temperature sintering can be processes such as hot pressing sintering or spark plasma sintering.

[0102] In other embodiments, in addition to physical vapor deposition or chemical vapor deposition processes, a tungsten coating can be applied to a tungsten plate on the surface of the second structural member 200 by means of plasma spraying, laser cladding, etc., and the tungsten plate and the tungsten coating form the first structural member 100.

[0103] It should be noted that physical vapor deposition refers to the process of breaking down a target material into atoms / particles under vacuum through physical processes (sputtering, evaporation) to form a film on the surface of a workpiece, without any chemical reaction. Specifically, this application forms the first structural component 100 by breaking down tungsten material into atoms / particles and attaching them to a tungsten plate on the surface of the second structural component 200.

[0104] Chemical vapor deposition (CVD) refers to the process of introducing a reactive gas, causing a chemical reaction on the surface of a substrate, and depositing a solid substance to form a film. Specifically, in this application, a reactive gas is introduced into the second structural component 200 to cause a chemical reaction, resulting in the precipitation of solid tungsten, which is then deposited to form the first structural component 100.

[0105] It is worth noting that after physical vapor deposition, chemical vapor deposition, ion spraying or laser cladding, the first structural component 100 needs to be surface treated so that the surface roughness Ra of the side of the first structural component 100 facing the plasma is ≤1.6μm.

[0106] In some embodiments, the third structural component 300 may be manufactured by machining, laser processing, diffusion welding lamination or additive manufacturing, and may be provided with an inlet, an outlet and a sealing interface for the working medium.

[0107] In some embodiments, the second structural component 200, the third structural component 300 and the fourth structural component 400 are not limited to being welded sequentially (e.g., diffusion welding or vacuum brazing), but the second structural component 200, the third structural component 300 and the fourth structural component 400 can also be integrally composited and interface metallurgically bonded by thermostatic pressing.

[0108] In a specific example, after the first structural component 100, the second structural component 200, the third structural component 300, and the fourth structural component 400 are processed, they are stacked and assembled in sequence. Then, they are combined into a single unit to form a protective structure 1000 by welding, hot static pressing, or other methods. After the composite is completed, the protective structure 1000 undergoes surface processing, leak detection, pressure resistance testing, and non-destructive testing. A predetermined working medium is then introduced into the third structural component 300. Finally, the thermal conductivity and thermal buffering capacity of the third structural component 300 are calibrated through steady-state thermal conductivity testing and pulse thermal shock testing.

[0109] In summary, the first structural component 100, the second structural component 200, and the third structural component 300 can be integrally formed by additive manufacturing to create a continuous structure of the first structural component 100, the second structural component 200, and the third structural component 300; the first structural component 100, the second structural component 200, and the third structural component 300 can also be prepared by composite processes such as powder metallurgy, surface deposition, and hot isostatic pressing to achieve high-strength bonding and sealing connection between multi-layer materials.

[0110] The protective structure 1000 for the tokamak device is the same as the aforementioned protective structure 1000 for the tokamak device. The specific structure of the protective structure 1000 for the tokamak device will not be described in detail here.

[0111] As can be seen from the above method, the manufacturing method of the protective structure 1000 for a tokamak device in this embodiment of the invention can reduce the manufacturing difficulty of the protective structure 1000 and make it easier to ensure the protective performance of the protective structure 1000.

[0112] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0113] Other components of the protective structure 1000 for a tokamak device and its manufacturing method according to embodiments of the present invention, such as the specific material of the cooling medium and the specific structure of the gas generator, are known to those skilled in the art and will not be described in detail here.

[0114] In the description of this specification, references to terms such as "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0115] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A protective structure for a tokamak device, characterized in that, It includes a first structural component (100), a second structural component (200), a third structural component (300), and a fourth structural component (400) arranged in sequence. Wherein, the first structural member (100) is adapted to be disposed facing the plasma, and the surface roughness Ra of the side of the first structural member (100) facing the plasma is ≤1.6μm; The second structural member (200) is formed as a porous member; The third structural member (300) has a channel (310) formed therein, the channel (310) being filled with a working medium. The third structural member (300) is configured to allow the working medium to exhibit different effective thermal properties by changing at least one of the pressure, temperature, phase, composition, or flow state of the working medium, thereby enabling the third structural member (300) to switch between a heat conduction mode and a heat buffering mode. In the heat conduction mode, the third structural member (300) is used to transfer heat from the second structural member (200) to the fourth structural member (400); in the heat buffering mode, the third structural member (300) is used to reduce the heat transferred thereto. The fourth structural member (400) has a receiving cavity (410) formed therein, and the receiving cavity (410) is suitable for being filled with a cooling medium.

2. The protective structure for a tokamak device according to claim 1, characterized in that, The third structural member (300) is provided with a plurality of channels (310), which are arranged at intervals; or, the plurality of channels (310) are arranged in parallel; or, at least two channels (310) intersect.

3. The protective structure for a tokamak device according to claim 1, characterized in that, The channel (310) is a straight channel or the channel (310) has at least one bend.

4. The protective structure for a tokamak device according to claim 1, characterized in that, The channel (310) has an inlet adapted to connect to an external storage unit adapted to store the working medium, and a control valve is provided at the inlet for changing the pressure or flow rate of the working medium.

5. The protective structure for a tokamak device according to claim 1, characterized in that, The working medium is at least one of the following materials: supercritical fluid, near-critical fluid, phase change thermal storage material, high heat capacity liquid, liquid metal, gas-liquid two-phase working fluid, molten salt or porous endothermic medium.

6. The protective structure for a tokamak device according to claim 1, characterized in that, The first structural component (100) is a pure tungsten component, a tungsten alloy component, a tungsten-copper composite component, a tungsten-rhenium alloy component, or a tungsten-tantalum alloy component; And / or, the first structural member (100) has a high-temperature resistant component on the side facing the plasma, the high-temperature resistant component being a carbide component, a nitride component, or a boride component.

7. The protective structure for a tokamak device according to claim 1, characterized in that, The second structural component (200) is a high-porosity tungsten alloy skeleton component; And / or, the fourth structural component (400) is a chromium-zirconium-copper component, the fourth structural component (400) is provided with a plurality of cooling pipes, the receiving cavity (410) is formed in the cooling pipes, and the cooling medium is water.

8. The protective structure for a tokamak device according to claim 1, characterized in that, The first structural component (100), the second structural component (200) and the third structural component (300) are integrally formed parts or separate parts, and the fourth structural component (400) is welded to the third structural component (300).

9. The protective structure for a tokamak device according to claim 1, characterized in that, It also includes a gas generator, which is located on the side of the first structural member (100) facing the plasma, and the gas generator is used to emit a gas that absorbs heat; The gas generator is used to emit at least one of deuterium, helium, and neon.

10. The protective structure for a tokamak device according to any one of claims 1-9, characterized in that, The protective structure is provided on at least one of the following: the first wall of the tokamak device, the divertor target plate of the tokamak device, the limiter of the tokamak device, the protective tile of the tokamak device, the diagnostic window of the tokamak device, and the inner wall of the vacuum chamber of the tokamak device.

11. A method for manufacturing a protective structure for a tokamak device, characterized in that, The protective structure for the tokamak device is the protective structure according to any one of claims 1-10, and the manufacturing method includes the following steps: The first structural component (100), the second structural component (200), and the third structural component (300) are integrally manufactured using additive manufacturing technology, and the fourth structural component (400) is welded to the third structural component (300). or, Prepare the second structural component (200); A tungsten plate is first welded onto the surface of the second structural component (200) using physical vapor deposition or chemical vapor deposition, and a tungsten coating is deposited on the tungsten plate. The tungsten plate and the tungsten coating together form the first structural component (100). The third structural component (300) and the fourth structural component (400) are prepared respectively, and the second structural component (200), the third structural component (300) and the fourth structural component (400) are welded in sequence.

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