JP3068922B2 - Superconducting magnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnet suitable for a nuclear fusion device.

[0002]

2. Description of the Related Art A conventional coil support will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the tokamak-type fusion device in a poloidal shape , showing each coil and its supporting device.
You. Fig. 5 shows other machines that make up the tokamak fusion device.
Instruments are omitted. FIGS. 6 and 7 show A in FIG.
2 shows a partially enlarged view of a part. Poloidal coil (1)
One of the supporting structures is that a poloidal coil (1) is installed on a groove-shaped support shelf (3) provided on a toroidal coil (2) installed radially with respect to the central axis of the fusion device. , Support
Bar (4) is fastened with bolts (5), and the vertical
It is a structure that supports magnetic force. Also, a poloidal coil
As another support structure (not shown) of (1), toroida
The poloidal coil (1) is installed directly on the coil (2)
And tighten the support frame with bolts to
Some structures support the force. Both have a structure that supports the electromagnetic force in the radial direction by the hoop stress of the coil itself.

FIG. 8 shows a configuration of a poloidal coil (1) .
This is a so-called cable-in-conduit type superconducting conductor in which a large number of superconducting wires (7) are housed inside a metal conduit (6) .
The conduit (6) the outer peripheral wire insulation (8) facilities of <br/> is in the, also, the entire paired locations insulating coil (11) is a coil into force is constituted.

[0004]

SUMMARY OF THE INVENTION A large fusion device and
And future fusion reactors in terms of power capacity and energy balance
Superconducting coils are used for poloidal coils and toroidal coils.
used. Superconducting coils are at room temperature during production and assembly.
However, when used, it was cooled to an extremely low temperature of about -269 ° C.
This causes a problem of heat shrinkage between devices. That is,FIG.
The coil is made of conduit (6) and insulating material as shown in
(8) The composite material of (11), which is generally an insulating material (8)
And the coefficient of linear expansion (α1) of (11) is the conduit
(6) and support on which the poloidal coil (1) is installed
Larger than the linear expansion coefficient (αs) of the material used for the shelf (3)
No. For this reason, when cooled from room temperature to -269 ° C, this linear expansion
The total thickness of the insulating material (t1)MultipliedGya
(G) occurs as shown in FIG. g = (α1−αs) · t1・ ΔT Here, ΔT indicates a temperature difference from room temperature to −269 ° C.
You.

When the apparatus is operated in such a state, the poloidal coil (1) impacts on the support cover by electromagnetic force , damaging the ground insulating portion (11) on the outer surface of the poloidal coil, and repeating such an operation. May cause dielectric breakdown . Accordingly, an object of the present invention is to provide a superconducting magnet without causing gap due to thermal shrinkage difference between the <br/> coil during cooling the members.

[0006]

According to the present invention, a distortion corresponding to a gap caused by a difference in heat shrinkage in a coil portion when a mounting bolt of a support cover is tightened is given to a bolt in advance within an elastic limit of the bolt.

[0007]

[Function] Therefore, by adopting such a configuration , the core
During yl cooling, the gap of each member between a coil portion caused by thermal contraction difference that strain previously applied to the bolt to return
Is more offset, the coil is provided without a gap in a predetermined space
Is done. Further, the electromagnetic force acting on the coil also reliably supported
Can have high because reliable superconducting magnet.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a superconducting device according to a first embodiment of the present invention.
3 shows a coil support device for a magnet . Figure 1
The poloidal coil (1) has a concave support shelf
(3) housed and supported inside, with a support cover on top
(4) is provided. This support cover (4) is a support shelf
Support shelf by long bolt (5) penetrating wall (3a)
(3) is firmly screwed. The support shelf (3) has room temperature.
When the coil (1) is stored, the coil
Out of the coil by the height g from the side support shelf wall (3a)
In other words, the support cover (4) was disposed at room temperature.
Sometimes, a gap is provided between the support shelf wall (3a) and the support cover (4).
A cap (g) is formed. Note that this gap (g)
The size of the coil in advance based on the cross-sectional shape of the coil and the shape of the support shelf.
Set to a value equal to or greater than the difference between the calculated heat shrinkage
You. Otherwise the same as the conventional coil support device
Therefore, the description is omitted.

Next, the operation will be described. At normal temperature assembly,
The bolt (5) has a gap (g) or more strain caused by a difference in heat shrinkage between the poloidal coil and the member to be used.
The support cover (4) and the support shelf (3)
Screw together. That is, the gap g becomes almost zero.
The support cover (4) and the support shelf (3)
Secure by tightening in (5). Here, Δl is
Δl is set to a value equal to or greater than g, when the amount of elastic elongation at the time of tightening is set.

[0010] In this case, σ = E · ε = E · (Δl / l) than Δl = (σ · l) / E Δl: elongation amount at the time of viewing bolt tightening σ: stress at the time of viewing bolt tightening ε: bolt tightening seen when strain l: bolt effective length E: longitudinal elastic coefficient of the bolt

In such a state, the bolt (5) is screwed.
Stored in the support cover (4) and the coil support shelf (3)
When the cooled poloidal coil (1) is cooled, a difference in heat shrinkage between the coil (1) and the support shelf (3) is caused as shown in FIG.
The gap (g) becomes almost zero. Because bolt
Almost the same as the gap (g) previously given in (5)
The amount of strain Δl is elastically based on the state (without strain)
By returning to the state, the gap (g) is offset.
That's why. For this reason, even when cooling, the support cover
(4) and the support shelf (3) remain tightly screwed.
Therefore, even when the coil (1) is cooled, it is supported by the coil (1).
Due to heat shrinkage between the shelf (3) and the support cover (4)
Can be installed without gaps.

3 and 4 show another embodiment of the present invention.
It is shown. As shown in FIGS. 3 and 4, a coil support (9) is provided discretely on the circumference of the poloidal coil (1), and the coil support (9) is directly driven .
It is a structure that is supported by a toroidal coil. Such a structure
Then, the poloidal coil (1) is a concave coil support
(9), and the upper surface of the coil support (9)
Is provided with a support cover (10). This support
Cover (10) is coiled with long bolt (5)
It is screwed to the support (9). In addition, coil support
(9a) The height of the wall (9a)
(9) formed below the top surface of the coil when installed in
ing. This difference in height is determined in advance by the cross-sectional shape and size of the coil.
A value equal to or greater than the difference between the two thermal shrinkage values calculated from the port shape
Is set to

Also in this embodiment, the bolt (5) is
Until the height difference between the il and the support wall is almost zero
No. By doing so, the bolt (5) is coiled in advance.
Strain greater than the amount of heat shrinkage generated between
Given within limits. Therefore, when cooling the coil
Even the strain applied to the bolts returns to the original
Since the heat shrinkage difference between the
(9) and the support cover (10) are screwed firmly.
Up to the gap between coil (1) and coil support (9).
It can be supported without generating a loop.

It should be noted that the present invention provides a support for a poloidal coil.
The present invention is not limited to this only, and does not depart from the gist of the present invention.
Can be used to support any coil
Yes, and it is not bound by the shape of its support.

[0015]

As described above, according to the present invention, even when the coil is cooled to -269 ° C., the coil can be installed without generating a gap due to a difference in heat shrinkage between the coil and the support. It is possible to provide a superconducting magnet that reliably supports a force.

[Brief description of the drawings]

FIG. 1 is a sectional view of a superconducting magnet according to a first embodiment of the present invention at normal temperature .

FIG. 2 shows the cooling of the superconducting magnet of the first embodiment of the present invention .
Sectional view at the time of rejection.

FIG. 3 is a plan view when the present invention is applied to a poloidal coil of a nuclear fusion device .

FIG. 4 is a sectional view taken along the line DD in FIG . 3;

FIG. 5 is an elevation view showing coils of a conventional fusion device .

FIG. 6 is a detailed sectional view of a portion A in FIG. 5 ;

FIG. 7 is a cross-sectional view of FIG . 6 when the poloidal coil is cooled.
FIG.

FIG. 8 is a partially enlarged sectional view of a conventional coil.

[Explanation of symbols]

1 ... Poloidal coil, 1b ... Center solenoid
Coil , 2 toroidal coil, 3 support shelf, 3a support shelf wall , 4 support cover, 5 bolt, 6 conduit, 7 superconducting wire, 8 wire insulation, 9 coil support , 9a coil Support wall , 10: Support cover , 11: Ground insulation , g: Gap.

Claims (3)

(57) [Claims] 1. A toroidal coil provided in a fusion device
A lid-shaped support that houses a poloidal coil in a concave support shelf
A cover is placed on the upper surface, and this support cover is
-And a superconducting magnet with a concave support shelf
At the time of assembling the bolt into the bolt beforehand.
Due to the difference in linear thermal expansion coefficient between the
Before distortion exceeding the thermal contraction difference generated during cooling of the idal coil
A superconducting magnet provided within the elastic limit of the bolt . (2) The device is placed on the periphery of the poloidal coil of the fusion device.
The concave coil support provided on the disk
A lid-shaped support cover is placed on top of the storage
On the support cover and the recess with a long bolt.
Superconducting magnet screwed with a shaped coil support
The poloidal coil was previously assembled with the bolt
Due to the difference in linear thermal expansion coefficient between the
The strain equal to or greater than the heat shrinkage difference generated during cooling of the poloidal coil
A superconducting magnet , wherein only the bolt is provided within the elastic limit of the bolt . 3. The bolt is attached to the concave member.
The poloidal coil when the poloidal coil is stored
The length of the vertical direction is longer than the length of the vertical direction.
A superconducting magnet according to claim 2.