JPS5934991B2 - Support device for poloidal magnetic field coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support device for a poloidal magnetic field coil of a tokamak-type nuclear fusion device.

A plan view of a conventional tokamak-type fusion device is shown in Figure 1.
A sectional view thereof is shown in FIG.

Next, this structure will be explained.

The vacuum container 1 is a hollow donut-shaped container that magnetically confines plasma, and the magnetic field necessary for this purpose is generated by a toroidal magnetic field coil 2.

In addition, a poloidal magnetic field coil 3 such as a current transformer coil for exciting and maintaining plasma current and a vertical magnetic field coil for generating a vertical magnetic field necessary to obtain equilibrium and stabilization of the plasma is arranged in a concentric circle with the vacuum vessel 1. It is arranged in a shape.

This poloidal magnetic field coil 3 is supported by a poloidal magnetic field coil support frame 4 arranged in the gap between the toroidal magnetic field coils 2 .

This poloidal magnetic field coil support frame 4 is fixed to a pedestal 7 via support columns 5 and toroidal magnetic field coil spacers 6.

FIG. 3 shows the relationship between the poloidal magnetic field coil 3 and the poloidal magnetic field coil support frame 4.

Let us consider the stress generated in the poloidal magnetic field coil 3 in this support structure.

Since the electromagnetic force 8 acts on the poloidal magnetic field coil 3 , a hoop stress is generated and the coil 3 receives a reaction force 9 from the support frame 4 .

Further, since the poloidal magnetic field coil 3 thermally expands due to the temperature rising due to energization, the reaction force 9 from the support frame 4 further increases.

Due to the electromagnetic force, thermal expansion, and reaction force from the support frame, a bending moment is generated in the poloidal magnetic field coil, causing it to deform as shown by the dotted line in FIG. 3.

The bending stress generated in the coil at this time reaches a maximum value σb near the support point 10, and the reaction force 9 is approximated by the following equation, where t is the distance between R1 support frames, and Z is the section modulus of the coil.

By the way, in this support structure, since the poloidal magnetic field coil support frame 4 is limited to the gap between the toroidal magnetic field coils 2, the number thereof on the entire circumference is limited to a number that does not exceed the number of installed toroidal magnetic field coils.

Therefore, the distance t between the support frames and the reaction force R generated on the support frames are
cannot be smaller than a certain value.

However, in conventional structures, local bending stress generated in the coil due to electromagnetic force due to coil energization and temperature rise tends to be excessive.

An object of the present invention is to provide a coil support device that alleviates bending stress acting on the coil by increasing the number of support points of the poloidal magnetic field coil 3 in the torus direction.

An embodiment of the present invention will be described below with reference to the drawings.

The basic configuration of the tokamak-type nuclear fusion device is the same as the conventional technology described above.

In the present invention, a new type of poloidal magnetic field coil support frame 11 is used as a support device for the poloidal magnetic field coil 3.

FIG. 4 shows a plan view of a tokamak-type nuclear fusion device using the poloidal magnetic field coil support frame 11, and FIG. 5 shows partial details thereof.

In Fig. 4, the poloidal magnetic field coils 3 are arranged at many locations (18 locations in this figure) on the entire circumference of the support frame 1, which are equally distributed radially.
Supported by 1.

The support frame 11 is fixed to a pedestal 7 (not shown) via support columns 5 and toroidal magnetic field coil spacers 6.

As shown in FIG. 5, the support frame 11 is made of a mechanically strong surface material 12 such as FRuP (reinforced plastic) or stainless steel (the one directly connected to the support column 5 is 122, and the one not directly connected is 12b) and FRP. It has a sandwich structure composed of a core material 13 of a porous insulator such as a honeycomb.

As shown in FIG. 5, a large electromagnetic force 8 acts on the poloidal magnetic field coil 3, and there is thermal expansion due to temperature rise.

For this purpose, a support frame 1 that closely supports each coil on the outer circumferential side
A large reaction force is generated in one part.

However, as shown in FIG. 5, the support frame 11 according to the present invention has more support points than the support frame 4 according to the prior art (see FIG. 3).

If this increase rate is multiplied by n, the reaction force generated on the main support frame will be Vn, and the distance between the support frames will be approximately L/n.

Here, R, 7 is the value in FIG. 3.

Therefore, the bending stress generated in the coil is reduced to 1/n2 compared to that of the prior art.

The reaction force generated in the support frame 11 is mainly received by the plane stress in the surface material 12, but the reaction force generated in the surface material 12b in the portion that is not directly connected to the support column 5 is applied to the support column 5 via the core material 13.
It is transmitted to the surface material 12a directly connected to the surface material 12a.

If the core member 13 is made of an insulating material such as FRP honeycomb, a sufficient one-turn resistance in the torus direction of the entire support structure can be ensured.

As shown in FIG. 6, the supporting frame 11 may have a structure in which all spaces between the surface materials 12 in the circumferential direction of the torus are filled with a core material 13 to improve strength.

Even with such a configuration, since the core material 13 is made of a material such as FRP honeycomb, it is possible to provide a support structure that is lightweight as a whole and has high rigidity.

The support device for the poloidal magnetic field coil is constructed of a support frame with a sandwich structure consisting of a surface material with high mechanical strength such as FRP or stainless steel and a core material of porous insulator with high mechanical strength such as FRP honeycomb, making it lightweight. A poloidal magnetic field coil that can reduce local stress acting on the coil by realizing a rigid poloidal magnetic field coil support device and increasing the number of support points for electromagnetic force and thermal expansion that act on the poloidal magnetic field coil. A support device is realized.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an example of a conventional tokamak-type nuclear fusion device, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig.
The figure is an enlarged perspective view of main parts of a conventional coil support device, FIG. 4 is a plan view showing an embodiment of the coil support device of the present invention, and FIG.
The figure is an enlarged perspective view of the main part, and FIG. 6 is a plan view of the main part showing a different embodiment of the present invention. 1... Vacuum container, 2... Toroidal magnetic field coil, 3... Poloidal magnetic field coil, 4...
... Poloidal magnetic field coil support frame (prior art),
5... Poloidal magnetic field coil support column, 6...
...Toroidal magnetic field coil spacer, 7...
Frame, 8... Direction of electromagnetic force acting on the poloidal magnetic field coil, 9... Direction of reaction force from the support frame acting on the poloidal magnetic field coil, 10...... Poloidal magnetic field coil Support points by support frame, 11... Poloidal magnetic field coil support frame (present invention), 12...
・Surface material, 13... Heartwood.

Claims (1)

[Claims] 1. In a support device for a poloidal magnetic field coil of a tokamak-shaped fusion device, multiple support frames are arranged radially evenly around the entire circumference, and each support frame is made of mechanically strong material such as FRP (reinforced plastic) or stainless steel. Large surface material and FR
A support device for a poloidal magnetic field coil constructed in a sandwich structure with a core material of porous insulator with high mechanical strength such as P honeycomb.