A poloidal flat plate limiter structure suitable for a tokamak device

Abstract

The present invention proposes a poloidal flat plate limiter structure suitable for a tokamak device, which is composed of a plurality of flat plate structures with the same internal flow channels but different external geometric dimensions, which are arranged in series in a poloidal manner through a plurality of coaxial tubes and a plurality of pipes. The coolant flows through the internal channels through the interaction of the coaxial tubes to cool each flat plate structure. This limiter arrangement can effectively reduce the effect of excessive local heat load caused by assembly errors between the flat plates, reduce the possibility of high-energy particles bombarding the cooling pipes, and improve the heat load bearing capacity of the limiter surface, and has the advantages of simplicity, reliability, and stability.

Description

Technical Field

[0001] The invention relates to the technical field of tokamak device limiters, and mainly to a poloidal flat plate limiter structure suitable for a tokamak device. Background Art

[0002] Nuclear fusion energy has the advantages of abundant resources, zero carbon emissions, and safety. It is an important way to build a clean, low-carbon, safe and efficient energy system. At present, the tokamak is considered to be one of the ways to first realize the application of controlled nuclear fusion. In the tokamak, the limiter is a component that goes deep into the vacuum chamber and directly contacts the high-temperature plasma. Its main function is to limit the plasma configuration, carry the plasma heat flux and high-energy particles, and protect the vacuum chamber and its internal components. The limiter is mainly composed of plasma-facing components, supporting and fixing structures, etc. At present, the plasma-facing components of the limiter in the fusion device are mostly bolt-connected graphite tile structures, and their maximum steady-state heat load capacity is about 2MW / m 2 With the increase of discharge parameters in physical experiments, the cooling performance of the limiter can no longer meet the requirements of the experiment, and obvious "hot spots" appear on the limiter, which eventually leads to ablation and breakage of graphite tiles. With the development of tungsten divertor technology, the tungsten divertor of the ITER tube-through structure has the ability to withstand a steady-state heat load of 10MW / m 2 The ability of through-tube structure has been gradually introduced into the design of limiters. However, the main problems faced in the design of existing through-tube structure tungsten limiters are: 1) complex process, long manufacturing cycle and high cost; 2) the limiter is assembled from multiple circumferential strings. The magnetic field lines in the tokamak are perpendicular to each string, which requires high control of the gaps between strings and installation accuracy. When there is a radial gradient between two adjacent tungsten strings, the edge of the protruding through-tube structure will be subjected to extremely high parallel heat flow, resulting in local overheating or even material melting, which is called edge effect. Tungsten melting directly affects the service life of plasma-facing materials and components, and the molten tungsten impurities sputter into the plasma, which will increase the proportion of plasma discharge ruptures and affect the safety of plasma operation. Summary of the invention

[0003] The limiter disclosed in the present invention is mainly aimed at improving the above-mentioned problems. In terms of improving the thermal load performance, tungsten is used as the plasma-facing material, and a technically mature flat plate structure is adopted. If necessary, a super-vaporized fin structure is added in the flow channel to improve the heat exchange performance. In terms of spatial layout, the strings are arranged in the pole direction so that each string is parallel to the upward magnetic lines of force of the tokamak ring. This can effectively avoid the edge effect caused by the installation accuracy problem between the strings. At the same time, in order to simplify the layout of the pipeline and avoid the pipeline being affected by high-temperature plasma, a coaxial tube is used to arrange the pipeline in the middle of the string and realize the interconnection of the cooling channels between the strings. Through these designs, the limiter can meet the thermal load bearing capacity while effectively reducing the cost, manufacturing cycle and installation difficulty.

[0004] The present invention is achieved through the following technical solutions:

[0005] The flat plate limiter structure is composed of a plurality of flat plate structures arranged in an arrangement; the internal flow channel structures of the plurality of flat plate structures are the same but the external geometric dimensions are different; wherein a single flat plate structure comprises a tungsten sheet, a copper transition layer, a CuCrZr layer, a stainless steel layer, a coaxial tube and a cover plate; the tungsten sheet is a plasma-facing surface material; relative to the running direction of the toroidal plasma, the plurality of flat plate structures are arranged in a polar direction, and the plurality of flat plate structures are connected in series through the plurality of coaxial tubes and a plurality of connecting pipes, the connecting pipes are arranged between adjacent flat plate structures, and the upper and lower ends thereof are respectively connected to the coaxial tubes of the adjacent flat plate structures.

[0006] Furthermore, the coaxial tube in the single flat plate structure includes an inner tube and an outer tube, a cooling channel is formed between the CuCrZr layer and the stainless steel layer, and the cooling channel is respectively connected to the inner tube and the area between the outer tube and the inner tube.

[0007] Furthermore, the head end of the plurality of plate structures arranged in polar direction is a head plate structure, and the tail end is a tail plate structure, the head plate structure includes an input pipe connected to its coaxial pipe, and the tail plate structure includes an output pipe connected to its coaxial pipe;

[0008] Among them, the coolant flowing in from the input pipe flows through the inner tube of the head flat plate structure and then flows into its cooling channel, and then flows into the area between its outer tube and inner tube, and then flows into the inner tube of the coaxial tube of the adjacent flat plate structure through the connecting pipe. After multiple such cooling cycles, the coolant flows out from the output pipe of the tail flat plate structure.

[0009] Furthermore, the input pipeline is arranged on one side of the coaxial tube of the head flat plate structure;

[0010] The output pipeline is arranged on one side of the coaxial tube of the tail flat plate structure.

[0011] Furthermore, the plurality of flat plate structures is 26 flat plate structures.

[0012] In the present invention, the coaxial tube is made of stainless steel, and is fixedly connected to the cover plate and the stainless steel layer by argon arc welding; the CuCrZr layer is fixedly connected to the stainless steel layer by explosion welding; the copper transition layer is fixedly connected to the tungsten sheet by casting, and then the copper transition layer is fixedly connected to the CuCrZr layer by brazing. With respect to the possible toroidal plasma running direction, the multiple flat plate structures in the limiter are arranged in a polar direction, which can effectively avoid the local excessive heat load effect caused by the assembly error between the flat plates.

[0013] The present invention has the following beneficial effects:

[0014] 1) The multiple flat plate structures constituting the limiter are arranged in a polar direction, which can effectively avoid the excessive local heat load effect caused by assembly errors between the flat plates.

[0015] 2) Compared with arranging the cooling pipes on both sides of the back of the limiter, the inlet and outlet cooling pipes are integrated in the middle of the back of the flat plate structure using coaxial tubes, which can effectively avoid the bombardment of high-energy particles.

[0016] 3) The limiter is constructed using a flat plate structure, with its internal flow channel facing the plasma side. If a super-vaporized fin structure is used, the ability of the limiter surface facing the plasma to withstand heat load can be further improved.

[0017] 4) The limiter structure has the advantages of simplicity, reliability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the limiter structure;

[0019] Figure 2 for Figure 1 Enlarged view of middle area I;

[0020] Figure 3 for Figure 2 Schematic diagram of the middle section;

[0021] Figure 4 for Figure 3 Sectional view at AA;

[0022] Figure 5 for Figure 3 Cross-sectional view at BB in the middle.

[0023] Explanation of the serial numbers in the accompanying drawings: 1-input pipeline, 2-output pipeline, 3-tungsten sheet, 4-copper transition layer, 5-CuCrZr layer, 6-stainless steel layer, 7-coaxial tube, 7-1-inner tube, 7-2-outer tube, 8-first connecting pipeline, 9-cover plate, 10-second connecting pipeline. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0025] See attached Figure 1 and 2 A poloidal flat plate restrictor structure suitable for a tokamak device is formed by 26 flat plate structures II with the same internal flow channels but different external geometric dimensions, which are connected in series in a poloidal manner through 26 coaxial tubes 7 and a plurality of first connecting pipes 8 or second connecting pipes 10. The poloidal direction is Figure 1 In the vertical direction, the flat plate structure is a horizontal structure, and 26 flat plate structures are arranged continuously in the polar direction.

[0026] A single flat plate structure II is composed of a tungsten sheet 3 (surface material facing the plasma), a copper transition layer 4, a CuCrZr layer 5, a stainless steel layer 6, an input pipe 1, a coaxial tube 7, a first connecting pipe 8 and a cover plate. Among them, the coaxial tube 7 is made of stainless steel and is fixed to the cover plate and the stainless steel layer 6 by argon arc welding; the CuCrZr layer 5 is fixed to the stainless steel layer 6 by explosion welding; after the copper transition layer 4 is fixed to the tungsten sheet 3 by casting, the copper transition layer 4 is fixed to the CuCrZr layer 5 by brazing. The material hierarchy composition of the other 25 flat plate structures is exactly the same as that of the flat plate structure II, such as the flat plate structure adjacent to the flat plate structure II.

[0027] In a tokamak device, plasma moves in a certain direction under the action of a magnetic field, such as Figure 1-5 As shown, relative to the possible toroidal plasma running direction, the poloidal arrangement of the 26 flat plate structures in the limiter can effectively avoid the excessive local heat load effect caused by assembly errors between the flat plates.

[0028] The coaxial tube 7 includes an inner tube 7-1 and an outer tube 7-2. For the flat plate structure II, the coolant flows from the input pipe 1, passes through the inner tube 7-1 of the coaxial tube 7, flows into the cooling channel in the CuCrZr layer 5 and the stainless steel layer 6, flows into the area between the outer tube 7-2 and the inner tube 7-1 of the coaxial tube 7 after circulation, and finally flows into the inner tube of the coaxial tube 7 of the adjacent flat plate structure through the first connecting pipe 8. After the cooling cycle of the adjacent flat plate structure, it flows into the next flat plate structure through the second connecting pipe 10. In this way, after multiple cooling cycles, it finally flows out from the output pipe 2.

[0029] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, and it should be clear that the present invention is not limited to the scope of the specific embodiments, for those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A poloidal flat plate limiter structure suitable for a tokamak device, characterized in that: The flat plate limiter structure is composed of a plurality of flat plate structures arranged in an arrangement, wherein the internal flow channel structures of the plurality of flat plate structures are the same but the external geometric dimensions are different, wherein a single flat plate structure comprises a tungsten sheet, a copper transition layer, a CuCrZr layer, a stainless steel layer, a coaxial tube and a cover plate, and the tungsten sheet is a plasma-facing surface material; relative to the running direction of the toroidal plasma, the plurality of flat plate structures are arranged in a polar direction, and the plurality of flat plate structures are connected in series through a plurality of coaxial tubes and a plurality of connecting pipes, wherein the connecting pipes are arranged between adjacent flat plate structures, and the upper and lower ends thereof are respectively connected to the coaxial tubes of the adjacent flat plate structures.

2. The poloidal flat plate limiter structure suitable for a tokamak device according to claim 1, characterized in that: The coaxial tube in the single flat plate structure comprises an inner tube and an outer tube, a cooling channel is formed between the CuCrZr layer and the stainless steel layer, and the cooling channel is respectively connected to the inner tube and the area between the outer tube and the inner tube.

3. The poloidal flat plate limiter structure suitable for a tokamak device according to claim 2, characterized in that: The head end of the plurality of plate structures arranged in polar direction is a head plate structure, and the tail end is a tail plate structure, wherein the head plate structure includes an input pipe connected to the coaxial pipe, and the tail plate structure includes an output pipe connected to the coaxial pipe; Among them, the coolant flowing in from the input pipe flows through the inner tube of the head flat plate structure and then flows into its cooling channel, and then flows into the area between its outer tube and inner tube, and then flows into the inner tube of the coaxial tube of the adjacent flat plate structure through the connecting pipe. After multiple such cooling cycles, the coolant flows out from the output pipe of the tail flat plate structure.

4. The poloidal flat plate limiter structure suitable for a tokamak device according to claim 3, characterized in that: The input pipeline is arranged on one side of the coaxial tube of the head flat plate structure; The output pipeline is arranged on one side of the coaxial tube of the tail flat plate structure.

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