RU127992U1 - FIRST WALL OF THE THERMONUCLEAR REACTOR - Google Patents

Abstract

1. The first wall of the fusion reactor, consisting of an inner wall of material with high thermal conductivity, with protective blocks attached to it through an intermediate layer, and with channels formed for passage for the passage of coolant, characterized in that the inner wall has a lot of recesses over the entire area, arranged in rows at equal distances from each other, while the tops of the recesses are connected to the outer wall, which is a thin-walled shell of structural material. 2. The first wall of the fusion reactor according to claim 1, characterized in that the intermediate layer and protective blocks have a shape that is paired with the shape of the inner wall. The first wall of the fusion reactor according to claim 1, characterized in that the inner wall is made of bronze. The first wall of the fusion reactor according to claim 1, characterized in that the intermediate layer is made of copper. The first wall of the fusion reactor according to claim 1, characterized in that the protective blocks are made of beryllium or tungsten, or graphite. The first wall of the fusion reactor according to claim 1, characterized in that the channels for the passage of the coolant are formed in the space between the outer and inner walls.

Description

The utility model relates to thermonuclear technology, namely to the construction of the first wall of a thermonuclear reactor.

Known designs of the first wall of a fusion reactor [1-4], the main elements of which are:

1. Facing - a protective layer in the form of tiles (tiles) facing the fusion plasma, designed to protect the structural material of the first wall from sputtering and erosion by heat fluxes and plasma particles. The elements of the protective layer are tiles (tiles) of a certain shape made of beryllium, tungsten or graphite and are attached to the surface of the structural material of the first wall using an intermediate copper layer that performs the functions of:

- mechanically binding material,

- compensator for relative deformation of the tail and the surface of the first wall,

- a structural element providing effective heat removal from the tail to the surface of the first wall.

2. A panel or shell structure with forced internal cooling made of structural materials.

The technology of applying a copper layer to the surface of the structural material of the first wall and fixing beryllium, tungsten or graphite tiles on it has been developed as part of the ITER developments [5].

Also known is a technical solution for powerful heat fluxes [2]. This decision can be considered as a prototype to the declared one.

In the indicated solution, the first wall may consist of rows of bronze tubes with monoblocks attached to them by means of an intermediate copper layer of graphite (or from another protective material) .. This technical solution was originally proposed for divertor and limiter elements of a thermonuclear reactor facing plasma for heat fluxes 10 MW / m ² , but due to recently discovered possible significant loads on the first wall, it is adapted to its design.

However, within the framework of this design it is difficult to bypass the technological holes in the first wall intended for neutral injection channels, diagnostics, and other purposes. It is also difficult to mount such a spherical wall. In the case of a compact reactor, such as, for example, TIN-ST, the divergence of the tubes closer to the equator on the outer first wall exceeds the permissible values for significant heat fluxes, since a forced increase in the width of monoblocks relative to the diameter of the tubes at the equator of the outer first wall leads to overheating of the heat-sensitive monoblocks and tube, the occurrence of cracks in the copper intermediate layer.

The technical result that can be obtained using this design of the first wall in a fusion reactor is to provide

- long-term operability of the first wall when exposed to extremely large heat fluxes from the plasma up to the level of 10 MW / m ² characteristic of a thermonuclear reactor;

- minimum thicknesses of the shells forming the first wall, as well as the very first wall, which is required to optimize neutron fields in a thermonuclear or hybrid reactor.

For this, the first wall of a thermonuclear reactor is proposed, consisting of an inner wall of a material with high thermal conductivity, with protective blocks attached to it through an intermediate layer, and with channels formed for the passage of coolant in it, while the inner wall has many recesses located over the entire area in rows at an equal distance from each other, while the tops of the recesses are connected to the outer wall, which is a thin-walled shell of structural material.

In addition, the intermediate layer and the protective blocks have a shape that is paired with the shape of the inner wall.

Also:

- The inner wall is made of bronze.

- the intermediate layer is made of copper.

- protective blocks are made of beryllium or tungsten or graphite.

The channels for the passage of the coolant are formed in the space between the outer and inner walls.

With compact dimensions of the vacuum chamber, for example, in the case of a thermonuclear neutron source — spherical tokamak (TIN-ST) [8], in which a large installation radius is 0.5 m, the necessary requirements arise for minimizing the thickness of the first wall and the vacuum chamber. The difference from the prototypes is that the cooling system of the first wall is not a series of independent channels with a coolant, but a common channel through which the coolant flows between the outer and inner shell of the first wall, forming a single stream over the entire section of the first wall, flowing around the connecting shells of the funnel and due to this, providing more intensive mixing of the coolant and heat removal, cooling a large area. Thus, there is no need to organize independent channels or cooling tubes over the entire area of the first wall. The proposed design also allows you to install technological holes in the sections of the first wall, which are almost impossible to implement without the use of bypasses for the coolant in the case of separate cooling channels.

In the TIN-ST neutron source project, the first wall also serves as a vacuum chamber. The outer steel shell can be strengthened by toroidal and poloidal stiffeners. The thickness of the outer steel shell may vary depending on the stiffness of the vacuum chamber with respect to a particular installation, in particular at additional loads resulting from possible disruption of the discharge current.

The proposed design of the first wall is new due to the fact that the design of the tail and the molded bronze shell ensures their more reliable fastening due to the identical shape of the mating surfaces of the tile and shell. This interface surface is different from the flat surface of the tile and the first wall in existing prototypes of the first wall and the shape of the tile has no analogues among the previously proposed [1-4, 6, 7].

The invention is illustrated by figures 1-7, where the positions indicated

1- - bronze shell

2 - steel shell

3 - intermediate copper layer

4 - tiles (protective layer, for example, from beryllium)

5 - coolant

Figure 1 shows a fragment of the inner and outer shell of the first wall.

The first wall consists of two thin-walled bonded shells with a thickness of 0.5-5 mm each - steel 2 (for example, stainless steel 316L) and bronze - 1 (copper alloy CuCrZr), between which flows coolant 5 (figure 1). The bronze inner shell (from the side of the thermonuclear plasma) has many recesses (funnels / bubbles) over the entire shell area, arranged in rows at equal distances from each other.

Figure 2 shows a fragment of the first wall from the side of the plasma (top view of the bronze shell 1) with four funnels for clarity without tiles and a copper layer.

Section AA in FIG. 2 is an isometric view of FIG. 3, where 1 is a bronze shell, 2 is steel. The tops (centers) of the funnels can be connected to the steel outer shell of the first wall by diffusion welding, for which a thin layer of steel can be previously applied to the bronze shell from the side of future welding. It is also possible to connect the bronze inner shell and the steel outer with the help of pins placed in the drilled round holes of a certain diameter in the center of the funnels and further in the adjacent steel shell.

Section AA in FIG. 2, complete with an intermediate copper layer 3 and tiles 4 in isometry, is shown in FIG. 4.

The tile form is shown in FIG.

Section AA in FIG. 2 with an intermediate copper layer 3 and tiles 4 is shown in FIG. 6 and FIG. 7. Figure 6 shows: a protective layer of block tiles from, for example, beryllium - position 4, a copper intermediate layer - position 3, an inner bronze shell of CuCrZr - position 1, an outer shell of 316L steel - position 2 and a heat transfer medium - position 5.

As an example, the first wall of TIN-ST. It contains a protective layer of beryllium in the form of the same type of blocks - tiles completely covering its surface from the side of the plasma. Tiles are square 15.6 × 15.6 mm and have a variable thickness over the area of the tile, which decreases from a maximum of 9.1 mm in the middle of the tile to a minimum of 2.5 mm at the edge of the tile. The total wall thickness with tiles is 11.3 mm. The gaps between adjacent tiles to compensate for their thermal expansion are 0.4 mm. The tiles are attached to the bronze surface of the cooled wall panel through an intermediate copper layer, the thickness of which increases from the minimum in the center of the tile 0.3 mm to the maximum along the edges of 0.6 mm, which more optimally compensates for the thermal expansion of the tile from its center to the edges, without creating excessive the thickness of the copper layer over the entire surface of the inner bronze shell. An intermediate copper layer may be absent at the edges of the Thai. In this case, the boundary of the copper layer may extend along the edge of the depression-funnel. In this case, the heat sink from the thail to the coolant occurs to a greater extent through the recesses in the bronze shell, reducing the temperature of the bronze shell outside the recesses and reducing the maximum thermal stresses in it. Fig.6 and Fig.7 shows the main geometric dimensions in section AA (Fig.2) of the first wall: L1 = 16 mm, L2 = 0.6 mm, L3 = 2.5 mm, L4 = l, 9 mm , L5 = 1 mm, R1 = 7.22 mm, R2 = 7.22 mm, R3 = 1 mm, R4 = 0.7 mm, R5 = 2 mm.

Dimensions shown may vary over a wide range depending on the particular installation.

The proposed design of the first TIN-ST wall operates under stationary conditions of the influence of the heat flux from the plasma due to the specifics of the installation itself. The nominal heat flux is 1.5 MW / m ² with maximum values up to 5 MW / m ² . The protective screen protects the surface of the structural material of the first wall facing the plasma from erosion by plasma ions, and also redistributes and averages the heat flux transferred to the first wall. The cooling of the first wall is carried out with a heat carrier - water under a pressure of the order of 10 atm, circulating inside the first wall, namely between the two shells forming the first wall. The coolant velocity is about 10 m / s. In the general case, the type and parameters of the coolant can be selected depending on the operating conditions of a particular installation.

Bibliography

1. Schedler et al., First-wall component with the tube segment. Patent USA No. 7,940,880 B2 Issued on May 10, 2011.

2. Friedrich et al., First-wall component for a fusion reactor. Patent USA No. 2008/0032530 A1 Issued on Feb. 7, 2008.

3. Schedler et al., First-wall component for a fusion reactor with a heat sink of a copper alloy. Patent USA No. 2008/0100991 A1 Issued on May 1, 2008.

4. Schedler et al. First-wall component for a fusion reactor with a heat sink of a copper alloy. Patent USA No. 2009/0175400 A1 Issued on Jul. 9, 2008.

5.ITER DDD, 2002.

6. Robert F. Bourque. Composite first wall for a fusion device. Patent USA No. 4,696,781 Issued on Sep. 29, 1987.

7. Gotoh et al., Nuclear fusion reactor. Patent USA No. 5,182,075 Issued on Jan. 26, 1993.

8. B.V. Kuteev et al., Steady-state operation in compact tokamaks with copper coils, Nucl. Fusion 51 (2011) 073013.

Claims (6)

1. The first wall of the fusion reactor, consisting of an inner wall of material with high thermal conductivity, with protective blocks attached to it through an intermediate layer, and with channels formed for passage for the passage of coolant, characterized in that the inner wall has a lot of recesses over the entire area, arranged in rows at an equal distance from each other, while the tops of the recesses are connected to the outer wall, which is a thin-walled shell of structural material. 2. The first wall of the fusion reactor according to claim 1, characterized in that the intermediate layer and the protective blocks have a shape that is paired with the shape of the inner wall. 3. The first wall of the thermonuclear reactor according to claim 1, characterized in that the inner wall is made of bronze. 4. The first wall of the thermonuclear reactor according to claim 1, characterized in that the intermediate layer is made of copper. 5. The first wall of the fusion reactor according to claim 1, characterized in that the protective blocks are made of beryllium or tungsten, or graphite. 6. The first wall of the fusion reactor according to claim 1, characterized in that the channels for the passage of the coolant are formed in the space between the outer and inner walls.

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