JPS5811035B2 - Support device for vacuum vessel for nuclear fusion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support device for a vacuum vessel for a nuclear fusion device, and particularly to a support device for a vacuum vessel for a nuclear fusion device suitable for a vacuum vessel that becomes hot and expands thermally.

In recent years, the development of nuclear fusion devices has made rapid progress, and the devices are also becoming larger and larger.

On the other hand, the temperature of the vacuum vessel that confines the plasma has come to be operated in a range from room temperature to a high temperature of several hundred degrees Celsius.

Such large, high-temperature vacuum vessels have major problems with their support systems.

In other words, in a torus-shaped fusion device, a toroidal magnetic field coil that surrounds a toroidal vacuum container that confines plasma inside, and is arranged at predetermined intervals in the circumferential direction of the torus, generates a toroidal magnetic field, and generates and controls plasma. Poloidal magnetic field coils and the like are arranged to perform this, and various measuring devices, energy injection devices, vacuum evacuation devices, etc. are also installed around the vacuum container.

These coils and various devices must maintain accurate mutual positional relationships with the plasma contained in the vacuum vessel.

Therefore, it would be extremely inconvenient if the vacuum container thermally expanded and changed in shape and dimension due to temperature changes, and the mutual positional relationship was disturbed due to this change.

For this reason, the support device that supports the vacuum vessel for a large fusion device must have a structure that allows the large thermal expansion at high temperatures to be freely released, and that also has the function of not causing misalignment of the mutual positions of the devices. Must be.

In addition, plasma is generated in the vacuum container during equipment operation.
During transient events such as annihilation, a large induced current flows, and this causes an electromagnetic force of indefinite direction and magnitude to act.

The support device must have great rigidity even against such electromagnetic force.

Conventional supporting devices of this kind are often fixed to a base using legs formed integrally with the vacuum container, or supported by a large number of arms, springs, etc. from a surrounding framework surrounding the vacuum container.

However, all of these supports lack flexibility,
It is difficult to say that it has the same functionality as a light in terms of lack of rigidity and position holding accuracy.

Therefore, with a focus on eliminating these drawbacks, support devices have been proposed that are equipped with a mechanism that detects the temperature of the vacuum container and adjusts the position of the support part in a constant relationship with the temperature. The configuration is complex and there are reliability issues.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a highly reliable vacuum container that does not restrict thermal expansion of the vacuum container and can reliably maintain the vacuum container in a predetermined position. The present invention provides a support device for a vacuum vessel for a nuclear fusion device.

The present invention provides a support member that directly supports the upper and lower sides of a vacuum container on the upper and lower pedestals, respectively, which is divided into parts, one of which is a support part that is fixed to the vacuum container, and the other part that is a support arm that is fixed to the upper and lower pedestals. The desired purpose is achieved by supporting the vacuum container by making the contact surfaces between the vacuum container and the support part inclined with respect to the horizontal direction so as to bring them into sliding contact.

Hereinafter, the present invention will be described in detail based on embodiments of the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

In the figure, 1 is a toroidal vacuum container that stores plasma inside, 2 is a support frame that supports the vacuum container 1 from the horizontal direction, 3 is a lower pedestal that supports the vacuum container 1 from below, and 4 is a support frame that supports the vacuum container 1 from below.
5 is a supporting part fixed to the outer periphery of the vacuum container 1; 6 is a supporting arm extending from the upper and lower mounts 3 and 4; the supporting arm 6 and the supporting part 5 are in contact with each other; The surfaces are inclined with respect to the horizontal direction and contact and support the vacuum vessel 1 by means of a slidable support surface 8 .

The vacuum vessel 1 is connected to the support frame 2 by pins 7 such that the position in the main radial direction of the torus and the position in the vertical direction are determined.

In addition to the components shown in FIG. 1, an actual nuclear fusion device includes the various coils and auxiliary devices described above, but these are not shown because they are unnecessary for understanding the present invention. It is.

Next, the operation of the support device of the present invention having such a configuration will be explained.

FIG. 2 is a conceptual diagram of the device to aid in understanding its operation.

In the figure, the same reference numerals as in FIG. 1 indicate the same or equivalent parts.

In the figure, point A is the connection point between the vacuum container 1 and the support frame 2, and becomes an immovable reference position in the radial direction of the torus when the temperature of the vacuum container 1 increases.

In this embodiment, the vacuum vessel 1 is constructed such that a bellows is interposed in a part of the torus in the circumferential direction so that thermal expansion in the circumferential direction of the torus is absorbed by the bellows.

Point B is the position of the support point of the support part 5 placed on the outer periphery of the vacuum vessel 1 in normal conditions.

Consider the displacement of point B when the temperature of this vacuum vessel 1 increases.

It is assumed that the temperature of the vacuum vessel 1 rises uniformly, the temperature rise is ΔT, and the coefficient of linear expansion of the material constituting the vacuum vessel 1 is α.
Then, the horizontal displacement of point B is Δl=ΔT×α×l (1), and the vertical displacement is Δb=ΔT×α×b (2) causes displacement.

As a result, point B moves to point B'.

Then, point B' exists on the extension of the line connecting points A and B.

That is, the support point B provided on the outer periphery of the vacuum container 1 is
It moves along the extension of points A and B in response to temperature changes in the vacuum container 1.

Therefore, in order for the support part 5 of the vacuum container 1 to support the vacuum container 1 without restricting its thermal expansion, A.

What is necessary is to use a support method that allows movement on an extension of point B.

In the present invention, the contact surface between the support arm 6 extending from the upper and lower frames 3 and 4 to support the vacuum container 1 and the support portion 5 provided on the outer periphery of the vacuum container 1 is indicated by A.

It is configured to have the same inclination angle θ as the extended surface of point B, and is slidably supported on this surface so that the above-mentioned function can be exhibited.

With this configuration, the position of the support part 5 on the outer periphery of the vacuum container 1 moves on the extension of points A and B from point B to point B' due to temperature rise, but at any of these positions, A supporting surface is present and does not constrain it against thermal expansion.

Next, functions for gravity and electromagnetic force acting on the vacuum container 1 will be explained.

The vacuum vessel 1 is supported at points A and B, and point A is a pin connection and is an immovable reference point.

Point B is displaced due to thermal expansion, but as mentioned above, the locus of this displacement and the inclination of the support surface match, so depending on the temperature change, a gap may occur in the support part, or the entire vacuum vessel 1 may move vertically. Therefore, the vacuum container 1 is always maintained in a constant supported state.

Note that the electromagnetic force acting on the vacuum container 1 is a large force that tends to displace the vacuum container 1 in one direction, either downward or upward, similar to gravity.

In response to this type of electromagnetic force, the vacuum container 1 is
It is directly supported by support arms 6 extending from the lower frames 3 and 4, and its movement is prevented by its compressive force.

Further, as mentioned above, the supporting state does not change even when the temperature changes, so a strong supporting state can be ensured.

With the configuration of the supporting device for a vacuum vessel for a nuclear fusion device according to this embodiment, even if the vacuum vessel 1 is large and has a high temperature,
It always satisfies the same support conditions against temperature changes, does not restrict its deformation, and does not generate thermal stress or unacceptable deformation.

As a result, it becomes possible to easily realize a high-performance device that maintains the mutual positional relationship with other components with high precision.

Next, specific examples for carrying out the present invention will be described.

FIG. 3 is a conceptual diagram illustrating a more generalized case of the present invention.

In the conceptual diagram of Fig. 2, we have explained the case where the vacuum vessel 1 has an immovable support point at point A and the temperature of the whole changes uniformly, but in actual equipment, this is not always the case. It doesn't necessarily mean it will turn out like this.

FIG. 3 explains such a case, and corresponds to a case where the temperature of the vacuum vessel 1 is substantially non-uniform in the horizontal and vertical directions.

In this example, thermal elongation also occurred in the support frame 2 of the vacuum container 1 due to heat transfer.

In such an example, the practical fixed point is A'
Point B of the support part of the vacuum vessel 1 is determined by the length l from point A', the average temperature rise ΔTl during this period, and the average linear expansion coefficient αl, Δl=ΔTl×αl×l... ...(3) A horizontal displacement is produced.

Similarly, the vertical displacement is the average temperature rise in this direction Δ
When Tb is the average linear expansion coefficient αb, a displacement of Δb=ΔTb×ab×b is generated.

Then, point B of the support section moves along a plane including A' to B to B'.

That is, when attempting to specifically apply the present invention, after considering the temperature distribution of the actual device and the combination of materials used,
It will be understood that the angle θ at which the support portion B point on the outer periphery of the vacuum vessel 1 moves is actually determined, and the contact support surfaces of the support portion 5 and the support arm 6 are configured to match this angle.

Note that the examples shown in FIGS. 1, 2, and 3 illustrate the basic concept of the present invention, and various modifications may be necessary in each embodiment. Needless to say.

For example, the first idea is to improve the contact support surface.In order to make it easier to move on the surface and to prevent damage to the surface, placing rollers, spheres, etc. on the surface and rolling it is not possible due to gravity. This is necessary when a large electromagnetic force is supported.

Further, for the same purpose, an anti-friction material or a substance with a small coefficient of friction may be interposed on the contact surface.

The second idea is to absorb some errors in thermal expansion, and it is also necessary to interpose an elastic body on the support surface to absorb minute displacement errors.

According to the supporting device for a vacuum vessel for a nuclear fusion device of the present invention as described above, the support member that directly supports the upper and lower sides of the vacuum vessel on the upper and lower pedestals, respectively, is divided, and one part is fixed to the vacuum vessel by the support part, and the other part is fixed to the vacuum vessel. are used as supporting arms to be fixed to the upper and lower frames,
In addition, since the contact surface between the support arm and the support part is inclined with respect to the horizontal direction and the vacuum container is supported by sliding contact, even if the vacuum container is large and has a high temperature, the It is possible to obtain a support device with an extremely simple structure that does not restrict thermal expansion due to temperature changes, maintains a predetermined position correctly, and has extremely high rigidity against electromagnetic force and earthquakes, and is highly reliable. Therefore, it is very effective when used as a support device for a large-sized vacuum vessel for a nuclear fusion device.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a vacuum container support device showing one embodiment of the present invention, and FIGS. 2 and 3 are conceptual diagrams of the structure for explaining the operating principle of the support device. 1... Vacuum container, 2... Support frame, 3.
...Lower stand, 4...Upper stand, 5...
...Support part, 6...Support arm, 8...
・Sliding support surface.

Claims (1)

[Scope of Claims] 1. A torus-shaped vacuum container that encloses plasma therein is supported on a support frame, and a reference mounting portion that serves as an immovable reference position in the radial direction of the torus when the vacuum container thermally expands; A support device for a vacuum vessel for a nuclear fusion device is provided with a support member that directly supports the upper and lower sides of the vessel, and a support member that directly supports the lower pedestal, respectively. , a nuclear fusion device characterized in that the vacuum vessel is supported by support arms fixed to the lower pedestal, and contact surfaces between the support arms and the support part are inclined with respect to the horizontal direction so as to be in sliding contact with each other. Support device for vacuum containers. 2. Claim 1, wherein the contact surface between the support part and the support arm is on a line connecting the immovable reference position of the reference attachment part and the support point of the support part before thermal expansion of the vacuum container.
A support device for a vacuum vessel for a nuclear fusion device as described in 1. 3 The angle of inclination of the contact surface between the support part and the support arm with respect to the horizontal direction is the angle formed by a horizontal line passing through the immovable reference position of the reference attachment part and a line connecting the immovable reference position and the support point of the support part. A support device for a vacuum vessel for a nuclear fusion device according to claim 1, wherein the support device is substantially the same.