JPH01105190A - Fusion reactor wall - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a first wall (hereinafter referred to as the reactor wall) that encloses the core plasma of a nuclear fusion reactor, and particularly relates to a protection device that constitutes the core plasma side of the reactor wall. The present invention relates to a structure of a fusion reactor wall suitable for effectively degassing tiles.

[Conventional technology]

Conventionally, regarding fusion reactor walls, Japanese Patent Application Laid-Open No. 58-24633
As described in Japanese Pat. Alternatively, it has a structure in which a conductive material such as graphite is bonded or mechanically fastened to a metal substrate via an insulating layer, and these protective tiles are electrically connected to the metal substrate, or Adjacent protective tiles were electrically insulated.

[Problem that the invention seeks to solve]

In the case of the fusion reactor wall according to the above conventional technology, when performing vacuum degassing of the protective tiles, there is a method of indirectly heating the reactor wall using radiation by heating the vacuum container, For example, methods are used to circulate high-temperature gas, or to form plasma in the reactor core and then change the confining magnetic field to apply plasma energy to the reactor wall to heat the reactor wall. Ta. However, the indirect heating method has the disadvantage that it is necessary to heat the entire vacuum container, which has a large heat capacity, and that heating takes a long time and requires a large amount of electric power. Although effective, circulating hot gas within the cooling channels subjects the cooled substrate to severe temperature cycling and is limited in the temperatures that can be reached. In the heating method using plasma itself, the heating time is as short as several tens of milliseconds, and it is difficult to freely control the incident region of plasma energy.

A feature of the present invention is that the furnace walls are efficiently heated to degas.

[Means for solving problems]

The above purpose is to directly energize multiple protective tiles that are electrically insulated from the cooling board and electrically connected to each other.
This is achieved by heating.

[Effect]

FIG. 2 is a schematic diagram showing the cross-sectional structure of a magnetic field confinement type fusion reactor. The furnace wall 1 of the present invention is installed between the vacuum vessel 2 and the plasma 3 to protect the vacuum vessel 2 from the heat load and load flowing from the plasma 3.

Plasma 3 is a toroidal coil 4. Poloidal coil 5
and is formed into a torus shape by the balanced magnetic field induced by the plasma current. Therefore, the furnace wall 1 is generally divided into two parts, protecting the inner vacuum wall and the outer vacuum wall of the torus. The side of the furnace wall facing the plasma is covered with a protective tile 6, while a cooling substrate 8 is placed on the side of the vacuum vessel 2 via an intermediate material 7 for thermal contact with the protective tile 6. heat flowing from the plasma into the protective wall surface is removed. The protective tiles on the furnace wall are sequentially electrically connected and connected to current terminals 9 provided on the end face of the furnace wall to form a resistance circuit. By supplying power to the lead wire 10 connected to the circuit made of such a protective tile, the protective wall can be heated and the surface of the protective wall can be efficiently degassed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The protective tile 6 is fastened onto a cooling substrate 8 having cooling channels 11 via an intermediate material 7 with good thermal conductivity by metallurgical or mechanical methods.

The intermediate material is carbon fiber-reinforced copper (or aluminum) material with excellent stress relaxation properties, felt made of molybdenum, vanadium, titanium and alloys based on them, copper, tungsten, or graphite fibers. , or textiles are suitable. The protective tile 6 is made of graphite, TiC,
It is composed of a protective material 13 made of SiC, a composite material thereof, or metal beryllium, and an electrical insulator 1fH4 placed on the cooling board 8 side. The electrical insulating layer is made of diamond, SiC, or BN, which has excellent thermal conductivity.

AQN, 5iaN+, etc. are suitable, especially diamond films formed by vapor phase synthesis, 1-2% by weight BeO
A SiC sintered body containing is desirable.

The insulating layer of SiC, BN, AQN, etc. is formed by directly forming the raw material powder on the graphite or ceramic material used as the protective material 13 by pressurized (or normal pressure) sintering, so that the bonding interface is It is possible to realize a laminated protective tile 6 with a small thermal contact resistance value. The angle formed by the side surface of the protective tile 6 with the bottom surface is 30' to 80°, and the cross section of the base of the protective tile is processed to be trapezoidal.

A wedge-shaped connector 12 having a wedge-shaped cross section is inserted into the gap between adjacent protective wall tiles so as to be in close contact with the side surface of the protective tile, thereby establishing electrical contact between the adjacent protective tiles. The side of the wedge-shaped connector facing the plasma is made of a good electrical conductor such as graphite.
On the other hand, the cooling board side has a two-layer structure formed of an insulating layer 14 to insulate the protective material 13 and the cooling board 8.

A connecting terminal 9 is connected to the side surface of the protective tile 6 located at the end of the row of mutually coupled protective tiles 6, and is used as a terminal for energizing the protective tile. When the protective tiles are heated with electricity, they expand, especially in the direction of the plate surface, and the spacing between the protective walls decreases as the temperature increases. By making the contact surface between the wedge-shaped connector 12 and the protective tile 6 of a material with a small coefficient of friction, such as graphite, the protective tile 12
As the wedge-shaped connector 12 is pushed upward in FIG. 2, that is, toward the plasma side, with the thermal expansion of the protective tile 6, the thermal expansion of the protective tile 6 can be absorbed.

In that case, the wedge-shaped connector 12 is preferably attached to the cooling board 8 by a mechanical fastening method using a spring. The wedge-shaped connector 12 not only electrically connects the protective material 13 of the protective tile 6 to each other, but also prevents the protective tile from falling off from the cooling board 8 if the protective tile 6 breaks or the metallurgical fastening part peels off. It has the effect of preventing this and helps improve the reliability of the furnace wall. In this embodiment, the shape of the protective tile 6 is shown as having a rectangular base surface, but the same purpose can be achieved with other shapes, such as a triangle or a hexagon. Further, it is desirable that the position where the wedge-shaped connector 12 is installed between adjacent protective tiles 6 be determined so that the electromagnetic force generated by the induced current induced in the protective material 13 is below an allowable level. 15 in the figure is a slit.

In Example 2 to which the present invention is applied, the protective material 13 has a specific resistance of 10-3Ω, a base size of 10×10a++
When a graphite material with a thickness of 10 was used, the electrical resistance measured at both ends of the protective tile was 10 -3 Ω. When 300 people energized each protective tile for 10 hours, they were able to raise the temperature of the entire furnace wall to 600°C. in this case,
A total of No. 2 protective tiles were heated, and the power supply capacity used for heating was 2000 kW.

FIG. 3 shows another embodiment of the invention. The protective tile 6 is made of carbon fiber-reinforced carbon material, carbon fiber-reinforced ceramic material, or beryllium metal. The protective tile 6 is metallurgically or mechanically fastened to the cooling substrate 8 via the insulating layer 14 and the intermediate material 7. Protective tile 6
A slit 15 is cut in, and lead wires 10 are connected to connection terminals 9 provided at both ends to form a resistance circuit as a whole. By passing an alternating current or direct current through such a protection plate 6, the protection tiles 6 can be efficiently degassed.

According to this embodiment, the adjustment of the heating temperature can be easily controlled by the amount of electricity applied to the protective tile, so by optimally controlling the wall surface temperature during furnace operation, the absorption of hydrogen fuel viscous between the plasma and the furnace wall can be improved. The re-release process can be actively controlled.

〔Effect of the invention〕

According to the present invention, it is possible to directly heat the protective tiles that need to be degassed at the highest temperature before starting up and at any time during the operation of the fusion reactor.

[Brief explanation of the drawing]

Fig. 1 is a detailed structural diagram of a fusion reactor wall according to an embodiment of the present invention, and Fig. 2 includes a rotational symmetry axis of a magnetically confined fusion reactor having a fusion reactor wall according to an embodiment of the present invention. The vertical sectional view, FIG. 3, shows a detailed view of the fusion reactor wall of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Furnace wall, 2... Vacuum vessel, 4... Toroidal coil 5... Poloidal coil, 6... Protective tile, 7... Intermediate material, 8... Cooling board.

Claims (1)

[Scope of Claims] 1. A vacuum vessel for enclosing plasma particles, a magnetic field generating coil disposed around the outer periphery of the vacuum vessel, and a furnace wall facing the plasma particles of the vacuum vessel, comprising: A fusion reactor wall characterized in that the reactor wall has a laminated structure in which a conductive protective material layer facing the plasma particles is joined to a cooling substrate via an electrically insulating layer. 2. Claims characterized in that the conductive protective material layer forms one or more sets of electrically connected resistance circuits, and connection terminals for voltage application are provided at both ends of the resistance circuits. The fusion reactor wall described in item 1.