A divertor structure of a tokamak device and a design optimization method thereof

Abstract

The application discloses a divertor structure of a tokamak device and a design optimization method thereof, relates to the technical field of magnetic confinement nuclear fusion, and is based on a compact fusion reactor to carry out divertor physical structure design, and combines numerical simulation and evaluation technology to optimize the divertor physical structure, so that the optimal divertor structure is obtained, which can realize effective control of thermal load, and avoid disadvantages and limitations caused by the shape optimization technology and the external impurity injection technology; in addition, in the design optimization process, the impurity injection and impurity removal effects are considered, so that the optimal divertor structure also has good impurity removal level and impurity shielding capacity.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic confinement nuclear fusion, and in particular to a divertor structure of a tokamak device and a design optimization method thereof. Background Art

[0002] In a tokamak, the divertor, a key component, directs the interaction between plasma and the material surface to a region away from the core. Particle and energy flows from the core to the edge must be transported radially across the outermost closed magnetic field lines, into the open magnetic field lines, and then into the divertor operating space in the lower chamber.

[0003] Therefore, the primary function of the divertor is to achieve effective particle and heat flow control. Currently, for tokamaks in the field of magnetic confinement fusion with divertor components, the thermal load on the divertor target plate remains a difficult problem to overcome, especially for reactor-scale fusion devices. This refers to devices with very high fusion powers (i.e., the thermal power generated by the fusion reaction), typically in the hundreds of megawatts (MW) to gigawatts (GW) range. It is generally believed that radial transport is determined by two different physical mechanisms: drift-dominated radial transport and turbulence-dominated radial transport. For larger fusion devices, drift-dominated radial transport plays a less significant role, making turbulence-dominated radial transport more likely. In the turbulence-dominated regime, the vertical particle and energy transport systems determine the heat flow width. Research on the ITER device, the international thermonuclear fusion facility, shows that its heat flow width is very narrow, ranging from 1-3 mm. Without additional optimization measures, the heat load deposited on the target plate is sufficient to cause erosion or melting.

[0004] As the operating power of the fusion device increases, the heat load on the target plate will increase dramatically and exceed the existing engineering limit of the target plate material. At present, for low-power or medium-power fusion devices, the particle flow and energy flow flowing from the core to the edge and then deposited in the divertor area will also exceed the engineering limit of the target plate material by 10MWm -2 If the operation time is too long or the target plate is subjected to a heat load exceeding this limit, it will erode or melt the target plate. This is extremely detrimental to achieving long-term stable operation of the device. On the one hand, it will damage the target plate, reducing its service life; on the other hand, impurities generated by the target plate will be transported to the core area, causing the discharge to extinguish.

[0005] In summary, mitigating the thermal load on the target plate has become one of the greatest challenges facing divertor development. Existing solutions and implementation technologies for controlling the thermal load of divertors in fusion tokamaks primarily include:

[0006] (1) Configuration optimization technology that changes the magnetic field configuration structure of the device. This technology is to reduce the peak thermal load of the target plate by increasing the contact area between the plasma particle flow and the target plate. Its basic principle is: for fixed plasma parameters, that is, considering the same heat flux bombardment, the larger the effective area of ​​the target plate that withstands the heat load bombardment, the more conducive it is to controlling the peak thermal load of the target plate in theory. In addition, there is currently a divertor configuration with double X points, as well as snowflake and super X divertors developed in the past decade. These divertor configurations are all aimed at alleviating the thermal load of the divertor target plate as much as possible. Currently, advanced divertors are widely used, but the production of such divertor structures requires adding one or two pairs of poloidal field coils in the space under the divertor cavity to help generate additional X points. This technology faces numerous challenges, limitations, and drawbacks in practical applications, including: First, the added coils are relatively close together, preventing an unlimited increase in the divertor target plate's heat flux impact area or magnetic surface expansion; Second, the proximity of the added coils to the divertor plate results in insufficient divertor design space, particularly for tokamak-type fusion devices. This also makes it difficult to optimize operating modes or control heat loads through divertor design; Third, numerous factors must be considered in engineering design, making it difficult to implement coil layouts based on theoretical calculations. Therefore, implementing this type of divertor configuration places extremely high demands on engineering design and still faces numerous challenges and limitations in practical applications; Fourth, while this optimized divertor configuration theoretically increases the plasma deposition area on the outer target plate and alleviates heat loads to a certain extent, it is difficult to effectively alleviate heat loads on the inner divertor plate. In summary, configuration optimization technology can help mitigate the heat load on the outer divertor to a certain extent, but the heat load on the inner divertor plate cannot be addressed simultaneously. Furthermore, this technology is not only difficult to implement in engineering design and practice, but also has drawbacks that affect the design and layout of the divertor plate.

[0007] (2) Enhance the energy dissipation in the divertor region by injecting external impurities to further reduce the heat load deposited on the target plate. This method is an external means that can be used after completing the configuration optimization and divertor design. At present, nitrogen (N), neon (Ne) and argon (Ar) are mainly used. When these gases are injected into the running plasma, they will dissipate excess energy through linear radiation. At the same time, they will lose electrons and enter different charge states. This method can certainly help control the heat load of the divertor. However, there are also certain disadvantages and limitations: First, according to the introduction of this method, it is obvious that other particles (usually called impurities) besides fuel particles will be generated in the fusion device. The presence of impurities may be transported to the area above point X or even the core area where the fusion reaction occurs, which will inevitably radiate the energy generated by the core, which is extremely unfavorable for the occurrence of the fusion reaction; second, if the concentration of impurity particles exceeds a certain limit, it will cause the plasma discharge to extinguish instantly, which runs counter to the realization of long-pulse stable operation of the fusion device. In addition, the introduction of external impurities puts higher requirements on the impurity control and impurity removal in the divertor region. Moreover, in practice, external impurity injection requires embedding a complete external injection system in the device. This system not only needs to be engineered to be compatible with other engineering components, but also requires precise control. In practice, this can be said to be fraught with difficulties. Summary of the Invention

[0008] In response to the shortcomings and limitations of existing heat load control technologies such as configuration optimization and external impurity injection, this application proposes a divertor structure for a tokamak device and a design optimization method thereof. Based on the physical parameters and magnetic field topology of a compact fusion reactor, the divertor physical structure design is carried out. Combined with numerical simulation and evaluation technology, the divertor target plate heat load, neutral particle level, impurity level, etc. are comprehensively considered to optimize the divertor physical structure, thereby obtaining the optimal divertor structure.

[0009] On the one hand, the present application is implemented through the following technical solutions:

[0010] A divertor structure design optimization method for a tokamak device, the divertor structure design optimization method comprising:

[0011] Based on the geometric parameters and magnetic field topology of the compact fusion reactor, the short-legged wide-slot divertor structure and the long-legged narrow-slot divertor structure were designed, and the impact point locations of the inner and outer divertors were determined.

[0012] performing a divertor target plate heat load evaluation and a neutral particle deposition evaluation under the same input conditions for the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure, respectively, and determining the optimal divertor structure based on the evaluation results;

[0013] Under the same operating power conditions and the same upstream plasma density conditions, divertor structures with different target plate opening and closing angles are designed using the strike point of the optimal divertor structure as a starting point;

[0014] By using numerical simulation technology, the thermal load and impurity level of the divertor target plate at different target plate opening and closing angles are obtained respectively, and the optimal target plate opening and closing angle of the optimal divertor structure is determined according to the thermal load and the impurity level.

[0015] In some embodiments, the divertor structure design optimization method further includes:

[0016] The target plate edges near the coil positions in the inner divertor and the outer divertor are adjusted to be perpendicular to the coil edges.

[0017] In some embodiments, the steps of separately designing a short-legged wide-slot divertor structure and a long-legged narrow-slot divertor structure, and determining the striking point positions of the inner divertor and the outer divertor, specifically include:

[0018] Based on the magnetic field topology of the compact fusion reactor, a divertor throat is established in combination with a curved top plate designed to protect the coil structure below point X, which is compatible with the lower cavity divertor coil and the shielding blanket. The divertor throat is where the flow flows from the core region to the edge region and further into the entrance region of the divertor region.

[0019] A short-leg wide slot divertor structure and a long-leg narrow slot divertor structure are designed below the divertor throat bend, and the striking point coordinates of the inner divertor and the outer divertor are determined respectively.

[0020] In some embodiments, the step of evaluating the divertor target plate heat load and neutral particle deposition of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure under the same input conditions, and determining the optimal divertor structure based on the evaluation results, specifically includes:

[0021] The divertor upstream boundary conditions are obtained by calibrating the basic parameters of the compact fusion reactor. The divertor upstream boundary conditions include: the power flowing from the core region to the edge region is 120MW; the upstream plasma density of the edge region is (3.0-4.0)×10 19 m -3 The density of helium particles flowing into the edge region is 2.5×10 18 m -3 ;The heat flow width is 0.9169mm;

[0022] Under the same input conditions, a peak value of a heat load on an outer target plate of the long-leg narrow slot divertor structure is smaller than a peak value of a heat load on an outer target plate of the short-leg wide slot divertor structure, and a peak value of a neutral particle density on an outer target plate of the long-leg narrow slot divertor structure is greater than a peak value of a neutral particle density on an outer target plate of the short-leg wide slot divertor structure.

[0023] According to the above evaluation results, the long-legged narrow slot divertor structure is determined to be the optimal divertor structure.

[0024] In some embodiments, the design of divertor structures with different target plate opening and closing angles using the strike point of the optimal divertor structure as a starting point specifically includes:

[0025] Three different target plate opening and closing angles are designed with the striking point of the optimal divertor structure as the starting point, which are 20 degrees, 30 degrees and 40 degrees respectively.

[0026] In some embodiments, determining the optimal target plate opening and closing angle of the optimal divertor structure according to the heat load and the impurity level specifically includes:

[0027] The heat load and impurity level were both relatively low, and taking into account the off-target effect and the difficulty of engineering implementation, the optimal target plate opening and closing angle of the optimal divertor structure was determined to be 30 degrees.

[0028] On the other hand, the present application also proposes a divertor structure of a tokamak device, and the divertor structure is designed using the above-mentioned divertor structure design optimization method.

[0029] In some embodiments, the divertor structure comprises: an inner divertor target plate, an outer divertor target plate, an inner divertor baffle, and an outer divertor baffle;

[0030] The inner divertor target plate and the outer divertor target plate are both long-leg narrow slot structures, and the target plate opening and closing angles of the inner divertor target plate and the outer divertor target plate are 30 degrees.

[0031] In some embodiments, the edges of the inner divertor target plate and the outer divertor target plate near the coil are perpendicular to the coil edge;

[0032] The side walls of the inner divertor target plate and the outer divertor target plate have a certain thickness, which is about 10 to 15 cm.

[0033] In some embodiments, the divertor structure further includes: a slot structure for fitting and mounting the inner divertor target plate to the first wall, a slot structure for fitting and mounting the outer divertor target plate to the first wall, and a curved top plate compatible with the lower cavity divertor coil and shielding layer.

[0034] The application provides a divertor structure of a tokamak device and a design optimization method thereof. BRIEF DESCRIPTION OF DRAWINGS

[0035] The drawings described herein are used to provide further understanding of the embodiments of the application, form a part of the application, and do not constitute a limitation to the embodiments of the application. In the drawings:

[0036] Figure 1 The method flowchart of the embodiments of the application;

[0037] Figure 2 The magnetic field topology structure of the compact fusion reactor;

[0038] Figure 3 The divertor structure of the compact fusion reactor magnetic field topology structure shown in FIG. 1; Figure 2 The divertor structure of the compact fusion reactor magnetic field topology structure shown in FIG. 1;

[0039] Figure 4 The peak value of the outer target plate heat load of the divertor structure under a 160 MW fusion power;

[0040] Figure 5 The peak value of the neutral particle density of the outer target plate of the divertor structure under a 160 MW fusion power;

[0041] Figure 6 The long-leg narrow-slot divertor structure with different target plate included angles;

[0042] Figure 7 The trend of the peak value of the outer target plate heat load changing with the target plate opening angle;

[0043] Figure 8 The peak value of the impurity level (effective charge amount) of the inner and outer divertor regions;

[0044] Figure 9 The optimal divertor structure designed by using the design optimization method provided in the embodiments of the application;

[0045] Figure 10 The long-leg narrow-slot divertor structure designed by using the design optimization method provided in the embodiments of the application and the low-temperature pump helium exhaust efficiency comparison chart of the existing short-leg wide-slot divertor structure.

[0046] Reference signs and corresponding names of parts:

[0047] 1 - inner divertor target plate, 2 - outer divertor target plate, 3 - inner divertor baffle, 4 - outer divertor baffle, 5 - inner divertor target plate with groove structure for adaptation and mounting to the first wall, 6 - outer divertor target plate with groove structure for adaptation and mounting to the first wall, 7 - arc-shaped roof, 11 - edge of the inner divertor target plate close to the coil position, 22 - edge of the outer divertor target plate close to the coil position, 10 - core region, 20 - X-point, 30 - outer divertor region, 40 - inner divertor region, 50 - edge region. DETAILED DESCRIPTION

[0048] Hereinafter, the term "include" or "may include" used in various embodiments of the present application indicates the presence of the invented function, operation, or element, and does not limit addition of one or more functions, operations, or elements. Also, as used in various embodiments of the present application, the terms "include", "have", and their conjugates merely indicate the presence of a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be understood as excluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.

[0049] In various embodiments of the present application, the expression "or" or "at least one of A or / and B" includes any combination of the listed terms or all combinations thereof. For example, the expression "A or B" or "at least one of A or / and B" can include A, can include B, or can include both A and B.

[0050] The expressions (such as "first", "second", etc.) used in various embodiments of the present application can modify various constituent elements in various embodiments, but can not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the described elements. The above expressions are used only for the purpose of distinguishing one element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, the first element can be called the second element, and likewise, the second element can be called the first element without departing from the scope of various embodiments of the present application.

[0051] It should be noted that when a component is described as being “connected” to another component, the first component may be directly connected to the second component, and a third component may be “connected” between the first and second components. Conversely, when a component is described as being “directly connected” to another component, it can be understood that there is no third component between the first and second components.

[0052] The terms used in the various embodiments of the application are only used to describe the purpose of specific embodiments and are not intended to limit the various embodiments of the application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise limited, all terms used here (including technical terms and scientific terms) have the same meaning as the meaning generally understood by those of ordinary skill in the art of the application. The terms (such as the terms defined in the dictionary generally used) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having idealized meaning or too formal meaning, unless clearly defined in the various embodiments of the application.

[0053] In order to make the objectives, technical solutions and advantages of this application more clear, the present application is further described in detail below in conjunction with examples and drawings. The schematic implementation methods of this application and their descriptions are only used to explain this application and are not intended to limit this application.

[0054] Example:

[0055] Existing methods for mitigating the heat load deposited on the divertor primarily include configuration optimization and external impurity injection. Both methods have certain shortcomings, drawbacks, and limitations. For example, configuration optimization presents engineering challenges, namely, insufficient space to accommodate the divertor design and other diagnostic equipment. Configuration optimization is limited in increasing the heat-load-bearing area of ​​the divertor target plate, and can only increase the plasma-wetting area to a certain extent. External impurity injection, on the other hand, presents significant engineering challenges and places higher demands on the effective removal of impurities. Furthermore, neither configuration optimization nor external impurity injection considers issues such as particle removal, shielding, and potential neutron irradiation associated with the fusion device. To address this, this embodiment proposes a method for optimizing the divertor structure design for a tokamak device. By optimizing the divertor geometry, a long-legged, narrow-slot divertor structure compatible with the lower chamber of a compact fusion reactor is obtained. This divertor structure effectively controls heat loads while avoiding the drawbacks and limitations of configuration optimization and external impurity injection.

[0056] like Figure 1As shown, the divertor structure design optimization method proposed in this embodiment specifically includes the following steps:

[0057] Step 100 : Designing a short-legged wide-slot divertor structure and a long-legged narrow-slot divertor structure respectively based on geometric parameters and magnetic field topology related to the compact fusion reactor, and determining the strike point positions of the inner divertor and the outer divertor.

[0058] Among them, the geometric parameters related to the compact fusion reactor include the position data of the first wall, coil, and blanket of the compact fusion reactor; the magnetic field topology is obtained according to the fixed coil and current ratio, such as Figure 2 FIG. 1 shows a magnetic field topology of a compact fusion reactor, wherein the area covered by the blue magnetic surface on the right below the X point 20 is the outer divertor area 30 , and the area covered by the blue magnetic surface on the left below the X point 20 is the inner divertor area 40 .

[0059] The design process of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure is as follows:

[0060] First, based on the magnetic field topology of the compact fusion reactor ( Figure 2 As shown in FIG5 , in particular, the divertor operating space in the lower cavity of the device is designed to fully utilize the broadening effect of the magnetic surface at the bend of the original magnetic field topology structure, and to combine the curved top plate compatible with the divertor coil of the lower cavity and the shielding cladding designed to protect the coil structure below point X, thereby establishing a divertor throat. The divertor throat flows from the core area to the edge area and further into the inlet area of ​​the divertor area, thereby enhancing the particle circulation effect and the sealing performance of the divertor.

[0061] Then, a short-leg wide slot divertor structure and a long-leg narrow slot divertor structure are designed below the divertor throat bend, and the intersection points of the outermost closed magnetic field lines and the target plate are determined respectively, namely the impact point coordinates of the inner and outer divertors (for the long-leg narrow slot structure, the fixed point position at the small angle is the impact point position). Figure 3 Shown for Figure 2 The divertor structures of the compact fusion reactor magnetic field topology are shown in Figure 1. (a) shows a short-legged, wide-slotted divertor structure, and (b) shows a long-legged, narrow-slotted divertor structure. For the short-legged, wide-slotted divertor structure, the inner and outer divertor impact points are (2175, -4000) and (3380, -4000), respectively; for the long-legged, narrow-slotted divertor structure, the inner and outer divertor impact points are (2396, -4318) and (3104.18, -4318), respectively, (unit: mm). Compared to the short-legged, wide-slotted divertor structure, the inner and outer target plates of the long-legged, narrow-slotted divertor structure are lowered 318 mm longitudinally, forming a long-legged, narrow-slotted divertor structure.

[0062] Step 200 , performing a divertor target plate heat load evaluation and a neutral particle deposition evaluation for the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure under the same input conditions, respectively, and determining the optimal divertor structure based on the evaluation results.

[0063] In step 200, the divertor upstream boundary conditions are obtained by calibrating the basic parameters of the compact fusion reactor device to facilitate the evaluation of thermal deposition and neutral particle deposition on the divertor target plate. The corresponding boundary conditions include:

[0064] (1) The power flowing from the core region to the edge region is P CIB =120MW (meeting the first-stage steady-state design power of the compact nuclear fusion reactor, corresponding to a fusion energy of 160MW);

[0065] (2) The upstream plasma density in the edge region is n sep =(3.0~4.0)×10 19 m -3 (meeting the core plasma confinement conditions);

[0066] (3) The density of helium particles flowing into the edge region is 2.5×10 18 m -3 ;

[0067] (4) The heat flux width λ under the operating conditions is calculated using the internationally recognized heat flux width calibration formula based on the plasma current and other device dimensions. q Approximately equal to 0.9169mm.

[0068] Get as Figure 4 and Figure 5 The evaluation results shown are: Figure 4 The peak thermal load of the outer target plate of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure at 160MW fusion power is shown. Figure 5 The figure shows the peak value of neutral particle density of the outer target plate of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure at 160MW fusion power. Figure 4 and Figure 5 It can be seen that under the same input conditions, the peak thermal load of the outer target plate of the long-legged slot divertor structure (about 25MWm -2 ) is much lower than the peak thermal load of the outer target plate of the short-leg wide-slot divertor structure (about 50MWm -2 ), and the peak neutral particle density of the outer target plate of the long-legged narrow slot divertor structure (about 5×10 17 m -3 ) is much larger than the peak neutral particle density of the outer target plate of the short-leg wide-slot divertor structure (about 2.5×10 17 m -3Based on the evaluation results, this embodiment determines the long-legged narrow slot divertor structure as the optimal divertor structure. It is particularly emphasized that for current international and domestic reactor-level fusion devices, when the fusion power reaches 150MW, the heat load can be reduced to 25MWm by simply designing the divertor target plate. -2 Therefore, the long-legged narrow slot divertor structure proposed in this embodiment fully utilizes the long legs and large magnetic surface expansion width to achieve ultra-high heat load control capability. In addition, the peak density of neutral particles also fully demonstrates the scientific reliability of the long-legged narrow slot divertor structure design. It should be noted that in this embodiment, Figure 4 and Figure 5 The design optimization method proposed in this embodiment is mainly illustrated by taking the peak value of heat load and the peak value of neutral particle density as typical values, but is not limited thereto. As long as the heat load, neutral particle density, etc. are taken into consideration when designing the physical structure of the divertor, the structure with better heat load and neutral particle density conditions can be selected as the optimal divertor structure.

[0069] Step 300 : Under the same operating power conditions and the same upstream plasma density conditions, divertor structures with different target plate opening and closing angles are designed using the strike point of the optimal divertor structure as a starting point.

[0070] In step 300, this embodiment designs three different target plate opening and closing angles, which are 20 degrees, 30 degrees and 40 degrees respectively. Figure 6 As shown, the three long-legged slot divertor structures with different target plate opening and closing angles have the same strike point position coordinates but different target plate opening and closing angles. It should be noted that the above design is only an exemplary description and does not limit the target plate opening and closing angle. In other optional embodiments, other numbers and target plate opening and closing angles at other angles can also be designed for numerical simulation. In addition, according to the computing power of the hardware equipment and the corresponding accuracy requirements, a more refined design can be performed. For example, within a preset angle range, more target plate opening and closing angles can be obtained by taking values ​​according to a preset step size (e.g., 1 degree, 2 degrees, etc.). The smaller the preset step size, the higher the accuracy, the larger the corresponding numerical calculation amount, and the lower the processing efficiency; conversely, the larger the preset step size, the lower the accuracy, the smaller the corresponding numerical calculation amount, and the higher the processing efficiency.

[0071] Step 400 , using numerical simulation technology, obtains the divertor target plate heat load and impurity level at different target plate opening and closing angles, and determines the optimal target plate opening and closing angle of the optimal divertor structure based on the heat load and impurity level.

[0072] In step 400, numerical simulation calculations are performed on the long-legged narrow slot divertor structures with three different target plate opening and closing angles to obtain corresponding numerical simulation results, such as Figure 7 and Figure 8 As shown. Among them, Figure 7 The peak thermal loads of the outer target plate at three different target plate opening and closing angles are shown. Figure 7 It can be seen that the peak value of the heat load of the outer target plate increases with the increase of the target plate opening and closing angle. When the target plate opening and closing angle is 20 degrees, the peak value of the heat load of the outer target plate is about 21MW m -2 At a target plate opening and closing angle of 30 degrees, the peak heat load of the outer target plate is about 25m -2 At a target plate opening and closing angle of 40 degrees, the peak heat load of the outer target plate is about 35m -2 . Figure 8 The peak values ​​of impurity levels (peak values ​​of effective charge) in the inner and outer divertor regions at three different target plate opening and closing angles are shown. Figure 8 It can be seen that the peak values ​​of the impurity levels in the inner and outer divertor regions (i.e., taking into account the impurity levels in the inner and outer divertor regions and taking the maximum value thereof) increase as the target plate opening and closing angle increases. At a target plate opening and closing angle of 20 degrees, the peak values ​​of the impurity levels in the inner and outer divertor regions are about 1.5, at a target plate opening and closing angle of 30 degrees, the peak values ​​of the impurity levels in the inner and outer divertor regions are about 1.7, and at a target plate opening and closing angle of 40 degrees, the peak values ​​of the impurity levels in the inner and outer divertor regions are about 2. It can be seen that from the perspectives of heat load control and impurity level control, a target plate opening and closing angle of 20 degrees is optimal. However, due to the divertor structure with a target plate opening and closing angle of 20 degrees, it will cause the over-and-off effect of the divertor, and the engineering implementation is extremely difficult. Therefore, this embodiment preferably uses a long-legged narrow slot divertor structure with a target plate opening and closing angle of 30 degrees, which can effectively reduce the heat load of the target plate and effectively shield the impurities. It should be noted that in this embodiment, Figure 7 and Figure 8 The design optimization method proposed in this embodiment is mainly illustrated by using the peak heat load and the peak impurity level as typical values, but is not limited thereto. As long as the heat load, the impurity level, etc. are taken into consideration when designing the physical structure of the divertor, the angle with the better heat load and impurity level (while considering other factors such as the difficulty of engineering implementation) can be selected as the optimal divertor target plate opening and closing angle for the optimal divertor structure.

[0073] Furthermore, in order to enhance the impurity removal capability, the divertor structure design optimization method proposed in this embodiment further includes:

[0074] Step 500: Adjust the target plate edges near the coils in the inner and outer divertors to be perpendicular to the coil edges to ensure the impurity removal capability during subsequent actual operation.

[0075] In this embodiment, the impurity removal capability is enhanced by adjusting the target plate edge near the coil position in the inner divertor and the outer divertor to be perpendicular to the coil edge. Figure 9 The long-legged slot divertor structure shown.

[0076] like Figure 9 As shown, the divertor structure obtained by the above-mentioned design optimization method in this embodiment mainly includes: an inner divertor target plate 1, an outer divertor target plate 2, an inner divertor baffle 3, an outer divertor baffle 4, a slot structure 5 for fitting and mounting the inner divertor target plate 1 to the first wall, a slot structure 6 for fitting and mounting the outer divertor target plate 2 to the first wall, and a curved top plate 7 compatible with the divertor coil and shielding layer of the lower cavity.

[0077] The inner divertor target plate 1 and the outer divertor target plate 2 both have long-legged narrow slot structures. The target plate opening and closing angles of the inner divertor target plate 1 and the outer divertor target plate 2 are preferably 30 degrees, and the target plate edges (i.e., 11 and 22) of the inner divertor target plate 1 and the outer divertor target plate 2 close to the coil position are perpendicular to the coil edge.

[0078] The long-legged narrow slot divertor structure designed in this embodiment achieves a closed exit through the inner divertor target plate 1, the outer divertor target plate 2, and their corresponding baffles, enhancing neutral particle circulation and particle removal. The sidewalls of the inner and outer divertor target plates have a thickness of approximately 10 to 15 cm. Cooling ducts can be designed within these plates to dissipate excess heat and reduce component temperatures, preventing damage from high temperatures. Furthermore, the inner and outer divertor baffles 3 and 4 provide space for the subsequent installation of gas injection ports.

[0079] In addition, the long-legged narrow slot divertor structure (i.e. Figure 9 The divertor structure shown in FIG2 is compared with the short-leg wide-slot divertor structure. The two divertor structures are tested for helium impurity removal under the same conditions. The results are as follows: Figure 10 The comparison of the helium particle flow reaching the pump with the pumping rate of the two divertor structures shown in Figure 1 is shown in Figure 2. Figure 10 It can be seen that the helium particle flow reaching the pump of the two divertor structures increases first, then decreases, and then increases again with the increase of the pumping rate, indicating that the helium particle flow reaching the pump of the two divertor structures has the same trend with the pumping rate of the pump. In actual engineering design, the pumping rate that the pump can achieve is generally 200m 3 s -1 For the long-legged narrow slot divertor structure, the best pumping efficiency (i.e., the maximum particle flow) that can be achieved corresponds to a pumping rate of about 175m 3 s -1 For the short-leg wide-slot divertor structure, the best pumping efficiency (i.e., the maximum particle flow) that can be achieved corresponds to a pumping rate of about 125m 3 s -1 In addition, under the same heating power and core parameter conditions, the helium particle flow of the long-legged narrow slot divertor structure reaching the pump is 5×1019 s -1 The helium particle flow of the short-leg wide-slot divertor structure reaching the pump is 4×10 19 s -1 .

[0080] In summary, compared with the short-leg wide-slot divertor structure, the long-leg narrow-slot divertor structure has an efficiency of about 25% in removing helium impurities.

[0081] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0082] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0083] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0085] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A method for optimizing the divertor structure design of a tokamak device, characterized in that: The divertor structure design optimization method includes: Based on the geometric parameters and magnetic field topology of the compact fusion reactor, the short-legged wide-slot divertor structure and the long-legged narrow-slot divertor structure were designed, and the impact point locations of the inner and outer divertors were determined. performing a divertor target plate heat load evaluation and a neutral particle deposition evaluation under the same input conditions for the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure, respectively, and determining the optimal divertor structure based on the evaluation results; Under the same operating power conditions and the same upstream plasma density conditions, divertor structures with different target plate opening and closing angles are designed using the strike point of the optimal divertor structure as a starting point; Using numerical simulation technology, the thermal load of the divertor target plate and the impurity level at different target plate opening and closing angles are obtained, and the optimal target plate opening and closing angle of the optimal divertor structure is determined based on the thermal load and the impurity level; The aforementioned design of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure, and determination of the striking point positions of the inner divertor and the outer divertor, specifically include: Based on the magnetic field topology of the compact fusion reactor, a divertor throat is established in combination with a curved top plate designed to protect the coil structure below point X, which is compatible with the lower cavity divertor coil and the shielding blanket. The divertor throat is where the flow flows from the core region to the edge region and further into the entrance region of the divertor region. A short-leg wide slot divertor structure and a long-leg narrow slot divertor structure are designed below the divertor throat bend, and the striking point coordinates of the inner divertor and the outer divertor are determined respectively.

2. The method for designing and optimizing the divertor structure of a tokamak device according to claim 1, wherein: The divertor structure design optimization method further includes: The target plate edges near the coil positions in the inner divertor and the outer divertor are adjusted to be perpendicular to the coil edges.

3. The method for designing and optimizing the divertor structure of a tokamak device according to claim 1 or 2, characterized in that: The method of evaluating the divertor target plate heat load and neutral particle deposition of the short-leg wide slot divertor structure and the long-leg narrow slot divertor structure under the same input conditions, and determining the optimal divertor structure based on the evaluation results, specifically includes: The divertor upstream boundary conditions are obtained by calibrating the basic parameters of the compact fusion reactor. The divertor upstream boundary conditions include: the power flowing from the core region to the edge region is 120MW; the upstream plasma density of the edge region is (3.0-4.0)×10 19 m −3 The density of helium particles flowing into the edge region is 2.5×10 18 m −3 ;The heat flow width is 0.9169mm; Under the same input conditions, a peak value of a heat load on an outer target plate of the long-leg narrow slot divertor structure is smaller than a peak value of a heat load on an outer target plate of the short-leg wide slot divertor structure, and a peak value of a neutral particle density on an outer target plate of the long-leg narrow slot divertor structure is greater than a peak value of a neutral particle density on an outer target plate of the short-leg wide slot divertor structure. According to the above evaluation results, the long-legged narrow slot divertor structure is determined to be the optimal divertor structure.

4. The method for designing and optimizing the divertor structure of a tokamak device according to claim 1 or 2, wherein: The design of divertor structures with different target plate opening and closing angles using the strike point of the optimal divertor structure as a starting point specifically includes: Three different target plate opening and closing angles are designed with the striking point of the optimal divertor structure as the starting point, which are 20 degrees, 30 degrees and 40 degrees respectively.

5. The method for designing and optimizing the divertor structure of a tokamak device according to claim 4, characterized in that: Determining the optimal target plate opening and closing angle of the optimal divertor structure according to the heat load and the impurity level specifically includes: The heat load and impurity level were both relatively low, and taking into account the off-target effect and the difficulty of engineering implementation, the optimal target plate opening and closing angle of the optimal divertor structure was determined to be 30 degrees.

6. A divertor structure of a tokamak device, characterized in that: The divertor structure is designed using the divertor structure design optimization method described in any one of claims 1 to 5.

7. The divertor structure of a tokamak device according to claim 6, characterized in that: The divertor structure comprises: an inner divertor target plate, an outer divertor target plate, an inner divertor baffle and an outer divertor baffle; The inner divertor target plate and the outer divertor target plate are both long-leg narrow slot structures, and the target plate opening and closing angles of the inner divertor target plate and the outer divertor target plate are 30 degrees.

8. The divertor structure of a tokamak device according to claim 7, characterized in that: The edges of the inner divertor target plate and the outer divertor target plate close to the coil are perpendicular to the coil edge; The side walls of the inner divertor target plate and the outer divertor target plate have a certain thickness of 10 to 15 cm.

9. The divertor structure of a tokamak device according to claim 7, characterized in that: The divertor structure further includes: a slot structure for fitting and mounting the inner divertor target plate and the first wall, a slot structure for fitting and mounting the outer divertor target plate and the first wall, and an arc-shaped top plate compatible with the lower cavity divertor coil and the shielding layer.

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