JPS5825997B2 - Toroidal coil of torus-shaped fusion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toroidal coil for a torus-shaped nuclear fusion device in which a cooling medium is passed through the coil conductor for cooling.

A plurality of toroidal coils in a nuclear fusion device are arranged in the toroidal direction, and a large current is passed through the coils to create a strong magnetic field for plasma confinement.

Since the current density of the coil conductor is required to be several 1 OA/m4, forced cooling is usually performed using a cooling medium such as cooling water.

If the device is small, a hollow conductor is often used as the coil conductor, but if the device is large, the hollow conductor manufacturing equipment is huge, so round steel pipes are used in the copper strip with grooves to accommodate cooling pipes. Alternatively, square steel pipes brazed at low temperatures are used.

The conventional method and the present invention also apply to the latter case.

The cooling structure of a conventional toroidal coil is shown in FIG.

FIG. 1 shows a toroidal coil of the upper and lower halves, which has recently been widely adopted.

Although the number of coil turns is 3 turns for convenience, it is usually about 10 turns.

The coil is usually firmly attached to a can (not shown) made of non-magnetic material so as to withstand strong electromagnetic force.

As shown in FIG. 2, the coil 1 consisting of the upper and lower parts has cooling pipes 2a each having a coil conductor 1a within the thickness.

The accommodation grooves 1c and Id of 1b are low-temperature brazed.

In the example of FIG. 1, the flow of the cooling medium such as cooling water comes out from the inlet from A, but the opposite may be possible.

The heat generated by the coil when the coil is energized is removed by the cooling medium as follows.

Cooling water at a low temperature enters the cooling pipes 2a and 2b from one side end A, and moves in the longitudinal direction of the coil 1 while removing heat from one side of the coil conductors Ia and 1b, and flows to the other end C on one side of the coil conductor Ia and 1b. go up to

Now, change the direction in the width direction of the coil conductors 1a, 1b and move to the other end 2 of the cooling pipes 2a, 2b on the other side of the conductor, and proceed in the longitudinal direction of the coil 1 while removing heat from this side. , the water exits as high-temperature water from the other end of the cooling pipe.

The conventional structure has the following drawbacks when a large current density is required, such as recent nuclear fusion experimental equipment.

That is, due to the long cooling path in the longitudinal direction of the conductor, the large width of the conductor, etc., a large temperature gradient occurs in the width direction of the conductor.

FIG. 4 shows theoretically calculated values when the conductor cooling structure model shown in FIG. 3 is energized.

5 is a cooling water temperature increase curve, and 6 is a conductor temperature increase curve.

Because the coil 1 is firmly supported within the can due to the difference in the winding degree in the width direction, the thermal stress in the width direction of the coil conductor becomes large, making it possible to provide a large current density and large coil. was impossible.

This invention was made in view of the current situation as described above.
Accommodation grooves are provided on the widthwise side surface of the coil conductor at symmetrical positions opposite to the center in the width direction and in the longitudinal direction, and at least a pair of cooling pipes divided into an outgoing path and a return path are fixed in the accommodation groove. , a torus-shaped fusion device that allows the cooling medium to flow in opposite directions in the outward and return paths within this cooling pipe, reducing the temperature gradient in the width direction of the coil conductor and reducing thermal stress in the width direction of the coil conductor. The purpose is to provide toroidal coils.

An embodiment of the present invention will be described with reference to FIGS. 5 and 6.

A partition plate 8 is firmly fixed in advance to the inside of the cooling pipe 7 by electron beam welding or the like, and the inside of the pipe is divided into an outward path and an inward path.

In this way, a pair of cooling pipes 7 having an outward path and a backward path are arranged in accommodation grooves 1e provided in the longitudinal direction and at symmetrical positions facing the widthwise centers of the coil conductors 1a and Ib on the widthwise side surfaces thereof. However, the brazing is fixed by the low-temperature brazing 4.

The material of the partition plate 8 is preferably one with high thermal insulation resistance, such as ceramics.

Cooling water, which serves as a cooling medium, flows from one end of the cooling pipe 7 in an outward path as shown by arrow A, and at the other end of the cooling pipe 7, enters a return path as shown by arrow B, and then enters a return path as shown by arrow C. It flows in the opposite direction and flows out to the outside.

In the coil 1 of the cooling structure of the above embodiment, the coil conductor 1
By reciprocating the cooling water in the cooling pipes 7 arranged on the width side surfaces of a and 1b, they flow in opposite directions, so the heat removal effect is averaged and the temperature distribution in the width direction is equalized. Thermal stress in the width direction of the conductor caused by the strong support of the side surface of the coil by cans or the like can be significantly reduced compared to conventional ones.

FIGS. 7 and 8 show theoretically calculated values of temperature distribution based on a model of coil conductors 1a and 1b to which an embodiment of the present invention is applied.

15 is a cooling water temperature curve, and 16 is a conductor temperature curve.

Coil conductor 1a. It can be seen that the temperature in the width direction of 1b is equalized.

Other embodiments of the present invention are shown in FIGS. 9 and 10.

Two cooling pipes 9a are arranged in parallel in each of the accommodation grooves 1e of the coil conductors 1a and 1b, and the forward and return cooling pipes 9 are intercepted, a spacing piece 10 is applied, and the cooling pipes 9 are firmly fixed by brazing with low-temperature solder 4. are doing.

Note that it is preferable to use ceramics or the like with high thermal insulation resistance for the spacer piece 10.

A space is provided between the cooling pipes 9a, 9a, and the presence of air reduces mutual heat conduction in the reciprocating path of the cooling water, thereby further equalizing the temperature gradient in the width direction of the coil conductors 1a, 1b.

11 is an air communication hole. FIG. 11 shows another different embodiment of the present invention, in which spacing pieces 10 are placed above the cooling pipe 9a and spaced apart in the longitudinal direction.

FIG. 12 shows yet another embodiment of the invention, in which a spacing piece 10 is placed between both cooling pipes 9a, 9a, and is spaced apart from each other in the longitudinal direction.

Note that the embodiment shown in FIG. 12 has coil conductors 1a and 1b.
Two pairs of cooling pipes 9 are installed at symmetrical positions opposite to the center in the width direction.
is located.

In the embodiment described above, the cooling pipes 9a and 9a are provided with a spacer 10 to provide a gap, but depending on the case, the spacer may be omitted and the gap may be eliminated.

As described above, according to the present invention, accommodation grooves are provided on the widthwise side surface of the coil conductor at symmetrical positions opposite to the center in the width direction and in the longitudinal direction, and the outgoing path and the returning path are provided in the accommodation groove. fixing at least one pair of divided cooling pipes;
The cooling medium flows in the longitudinal direction from one end of the cooling pipe in the outward path, flows into the return path at the other end of the cooling pipe, flows in the opposite direction, and flows out from the one end of the cooling pipe, so that the coil conductor This has the effect of equalizing the temperature in the width direction and reducing thermal stress in the coil.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing a conventional toroidal coil divided into upper and lower parts, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a model coil conductor with the cooling structure shown in Figure 1. A perspective view of
4 is a temperature curve diagram of the conductor and cooling water in the cooling pipe shown in FIG. 3, FIG. 5 is a partial side view showing an outline of a coil conductor cooling structure according to an embodiment of the present invention, and FIG. Figure VI-V
7 is a perspective view of a model coil conductor with the type of cooling structure shown in FIG. 5, FIG. 8 is a temperature curve diagram of the conductor and cooling water in the cooling pipe shown in FIG. A partial side view corresponding to FIG. 5 showing another embodiment of the present invention, and FIG.
11 and 12 are sectional views taken along line X--X in the figure, respectively, corresponding to FIG. 10 showing other different embodiments of the present invention. 1... Coil, 1a, 1b... Coil conductor, 1e... Housing groove, 7... Cooling pipe for reciprocating path, 8...・Partition plate, 9... Reciprocating path cooling pipe, 9a... Cooling pipe, 10...
...Spacing piece. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A coil conductor provided in a longitudinal direction and at a symmetrical position opposite to the widthwise center of the accommodation groove of the cooling pipe on the widthwise side surface thereof, which is fixed in the accommodation groove and connected to the outgoing path. The cooling medium is provided with at least a pair of cooling pipes divided into a return path and a return path, and the cooling medium is passed in the longitudinal direction from one end of the cooling pipe in the outward path, and is caused to flow into the return path at the other end of the cooling pipe to flow in the reverse direction. A toroidal coil of a torus-shaped nuclear fusion device, characterized in that the coil conductor is cooled by flowing out from one end side of the cooling pipe. 2. A toroidal toroidal fusion device according to claim 1, characterized in that the cooling pipe is divided into an outgoing path and a returning path in the width direction of the coil conductor by a partition plate placed inside the coil conductor in the longitudinal direction. coil. 3. The toroidal coil of a torus-shaped nuclear fusion device according to claim 1, wherein the cooling pipe is divided into an outgoing path and a returning path by separate pipes.