JP3517554B2 - Quench protection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quench protection device using a resistor, and more specifically, in a large-sized superconducting coil device, a superconducting coil is used to protect a superconducting coil when a quench occurs. And a quench protector having a resistor that absorbs stored energy.

[0002]

2. Description of the Related Art As a prior art of a resistor for a quench protection device used in a superconducting coil device, there is, for example, Japanese Patent Laid-Open Publication No.
There is one disclosed in Japanese Unexamined Patent Publication No. 6-6401.

In this prior art, an inner steel tubular resistor 21 and an outer steel tubular resistor 22 are arranged concentrically with each other,
An electric current enters the inner steel tubular resistor 21 from the electric terminal 28, and from this inner steel tubular resistor 21 to this and the outer steel tubular resistor 22.
It is folded back through the end plate 23 that electrically connects the lower end of the and seals liquid-tightly and moves to the outer steel tubular resistor 22 and the electric terminal 29.
It is configured to reach.

When the refrigerant 33 is supplied from the upper open end of the inner steel tubular resistor 21, the refrigerant 33
Passes through the lower communication hole 24 of the inner steel tubular resistor 21 into the gap formed by the outer diameter of the inner steel tubular resistor 21 and the inner diameter of the outer steel tubular resistor 22, and within the inner diameter of the outer steel tubular resistor 22. Both the inner and outer steel tubular resistors 21 and 22 are cooled by flowing in the direction opposite to the flow direction in the inner steel tubular resistor 21.

[0005]

By the way, in the above-mentioned prior art, the inner and outer steel tubular resistors 21, 22 of the resistor are provided.
Has a concentric structure, which causes the following problems.

(1) Since the size (length) of the resistor is large and the degree of freedom of the shape is small, the installation space is restricted. (2) Since the resistors 21 and 22 are concentric with each other, a welding operation is performed. Therefore, not only the manufacturing process is complicated, but also the labor is required and the cost is increased accordingly. (3) Even if the inner steel tubular resistor 21 is housed in the outer steel tubular resistor 22 and the refrigerant 33 is forced to flow, the heat radiating action between the resistors 21 and 22 cannot be said to be sufficient. ,
Moreover, after the refrigerant 33 flows downstream in the inner steel tubular resistor 21, the inside of the outer steel tubular resistor 22 and the inner steel tubular resistor 2
1 flows upward in the gap between the
, The flow path of the refrigerant is deteriorated, so that the fluidity of the refrigerant 34 is deteriorated, and the cooling performance of the resistor is deteriorated. (4) The current flowing through the inner steel tubular resistor 21 and the current flowing through the outer steel tubular resistor 22 are in opposite directions, and the magnetic fields are canceled inside and outside to reduce the inductance of both resistors. However, the current flowing through the inner steel tubular resistor 21 changes its direction in the right angle direction by the end plate 23, and then changes its direction in the right angle direction by the outer steel tubular resistor 22, resulting in a reciprocating form. Therefore, the magnetic field cannot be canceled at the portion where the direction of the current changes, and it is difficult to realize a lower inductance.

An object of the present invention, in view of the problems of the prior art, can be omitted the installation space, by increasing the heat radiation area can be increased cooling performance, a resistor can be further reduced inductance An object of the present invention is to provide a quench protection device provided with the device.

[0008]

For the above-mentioned purpose, the present invention is provided.
In the quench protection system, the normal, the excitation power supply
Current is applied to the superconducting coil, and it is excited during quenching.
Breaking means to cut off the power supply from the power supply to the superconducting coil
And a resistor connected in parallel to the breaking means,
Support means for supporting the resistor, ventilation in one direction to the resistor
And a cooling means for cooling the resistor respectively.
When the switch is off, it absorbs the energy stored in the superconducting coil.
And a resistor for protecting the superconducting coil.
The resistor of the container is characterized in that a thin plate is folded back in a wave shape along the length direction .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a superconducting circuit diagram to which the resistor of the present invention is applied, FIG. 2 is a perspective view showing an embodiment of the resistor of the present invention, and FIG. 3 is a perspective view showing a part of a resistor used in the resistor. 4 is a vertical sectional view showing a resistor.

Before describing the resistor of the present invention, a superconducting circuit using the resistor will be described with reference to FIG. In FIG. 1, a DC circuit breaker 3 and a superconducting coil 5 are connected in the forward direction to an exciting power source 1, and a switch 2 is connected in parallel to the exciting power source 1. DC breaker 3
On the other hand, the resistors 4 are connected in parallel with each other, and a quench protection device for protecting the superconducting coil 5 is constituted by the resistors 4 and the DC breaker 3 during a quench in which superconductivity does not function.

In this superconducting circuit, energy is stored in the superconducting coil 5 when a current is applied to the superconducting coil 5 through the DC circuit breaker 3 by the exciting power source 1 in a state where the switch 2 is normally disconnected. In this case, since the resistance value of the resistor 4 is much larger than the resistance value of the DC breaker 3, almost no current flows through the resistor 4.

Then, a quench occurs in which superconductivity does not function due to some abnormality. Therefore, when the power supply from the excitation power source 1 to the superconducting coil 5 is cut off by the DC circuit breaker 3 and the switch 2 is closed, the switch is closed. 2, by forming a closed circuit between the resistor 4 and the superconducting coil 5, the energy stored in the superconducting coil 5 is absorbed by the resistor 4, and the resistor 4 absorbs energy for protecting the superconducting coil 5. Function as a protective resistor for the.

If the superconducting coil 5 becomes large,
Since the energy stored therein inevitably becomes large, it is necessary to instantly interrupt the current by the DC circuit breaker 3 during quenching and absorb the large energy stored in the superconducting coil 5 by the resistor 4. Therefore, the following is required in the resistor 4 of the quench protection device.

(1) In the test using the superconducting coil device,
The resistor absorbs energy from the superconducting coil 5 and rises in temperature during the rest period of the test, but the heat is surely radiated during the rest of the test, and the energy absorption starts before the rest period. It must be cooled enough to cool down to temperature.

(2) In order to make the breaking operation of the DC breaker 3 accurate and easy, it is necessary to make the inductance as small as possible.

(3) Make the entire space as small as possible.

Therefore, the resistor of the embodiment has the above (1) to
The condition (3) is satisfied. That is, the resistor 4 of the embodiment has a resistor 11 formed by connecting a necessary number of resistor component parts 11 'formed by bending a thin plate into a corrugated shape by welding. The resistor 11 will be specifically described. The resistor 11 has a large heat capacity to reduce the resistance value and is made of non-magnetic austenitic stainless steel to reduce the inductance.

As shown in FIG. 3, the component 11 'of the resistor 11 is such that one end side 11a of the thin plate is formed straight along the width (depth) direction of the resistor 4, and the central portion thereof is U.
It is folded back in a letter shape to form a U-shaped folded portion 11b,
After forming the parallel portion 11c by extending the tip end side of the folded-back portion 11b in parallel with the one end side 11a, the tip end portion of the parallel portion 11c is further bent at a right angle along the length direction of the resistor 4 to be reinforced. The portion 11d is formed, and the tip of the reinforcing portion 11d is folded back at a right angle along the width direction of the resistor 4 to form the connecting rib 11e.

Then, one end side 11a of the second component 11 'is attached to the connecting rib 11e of the first component 11'.
Are connected by welding, and thereafter, this is repeated until the final component part is sequentially connected to form the resistor 11 as shown in FIG. In this case, each component 1
A desired resistance value can be obtained by selecting the number of 1's and the width dimensions of the one end side 11a and the parallel portion 11c. Note that the final component is not formed with the reinforcing portion 11d and the connecting rib 11e as shown in FIG.

Further, terminals 12A and 12B are formed at both ends of the resistor 11 in the lengthwise direction. Terminal 12A
Is attached to one end side 11a of the first component, and the terminal 12B is attached to the parallel portion 11c of the last component.

Further, in each of the component parts 11 ', from the viewpoint of rigidity while maintaining a desired dimension between the one end side 11a and the parallel portion 11b, the insulating spacer 1 is provided.
3 are arranged.

The resistor 11 as described above is supported by the supporting means. The support means is inserted along the length direction of the resistor 11 between the fixing channels 14 arranged on both sides of the resistor 11 and the lower portions of the fixing channels 14 and 14 facing each other. Insulating support member 15 for supporting the bottom and fixing channels 14, 1
4 is provided between the upper part and the lower part of the resistor 4, and has a long bolt 16 which holds the upper part and the lower part of the resistor 11 by the fixing channel 14 when tightened with a nut. Therefore, the resistor 11 has a shape open to the outside as a whole.

As shown in FIG. 4, the resistor 11 thus supported by the supporting means is mounted on the cooling and ventilation means via the insulator 17. Although not shown in detail, the cooling ventilation means has a cooling fan 19 inside the fan box 18, and when the cooling fan 19 is driven by a motor, the cooling fan 19 blows upward in one direction. As a result, each component 11 'of the resistor 11 is cooled. Therefore, fan box 1
The upper surface of 8 is provided with a window (not shown) for passing the air blown from the cooling fan 19.

In this case, a fan hood 20 is attached to the lower portion of the resistor 11 as shown in FIG. 2, and the air blown from the cooling fan 19 flows out to the outside on the lower side of the resistor 11 by the fan hood 20. Of the resistance element 11 and the resistance element 11 is guided along the height direction of the resistance element 11.
The components 11 'are distributed over the whole.
The fan hood 20 is formed of a lightweight thin plate made of synthetic resin or the like.

Therefore, the resistor 4 comprises a resistor 11 formed by connecting thin plate components 11 'formed in a corrugated shape along the lengthwise direction, and a support means for supporting the resistor 11. It is configured to have a cooling ventilation unit that ventilates the resistor 11 to cool the resistor 11.

In the resistor 4 of the embodiment, as described above, the resistor 11 is formed by connecting the component parts 11 'of the thin plate formed by folding back in the corrugated shape, so that the length of the resistor 11 is long. The resistance value can be arbitrarily selected by changing the dimensions in the depth direction and the width direction. Therefore, as in the prior art, the straight pipe type inner steel tubular resistor and the outer steel tubular resistor are concentrically arranged. Unlike the arranged resistors, the resistor 11 can be downsized, so that the installation space for the resistor 11 can be omitted. Moreover, since the resistance value can be arbitrarily selected by changing the lengthwise and widthwise dimensions of the resistor 11, the degree of freedom in shape is increased.

The resistor 11 is formed by connecting a plurality of corrugated component parts 11 'by press working, and the resistor 11 is supported by the supporting means and both sides of the resistor 11 are supported. Since it is sandwiched, the structure of the resistor 4 as a whole is simplified and can be easily manufactured.

Further, since the cooling air ventilation means blows air from the lower part to the upper part in one direction to cool the resistor 11, the resistor 11 is cooled. And the cooling performance can be improved. Moreover, even if the resistor 11 is formed by folding back the thin plate, since the thin plate forms the air passage, the entire thin plate can be uniformly cooled, and by folding back the resistor 11, The heat dissipation area can be increased, and the cooling performance can be further improved. In the illustrated embodiment, the resistor 11
Since a fan hood 20 is attached to the lower part of the fan, and the fan hood 20 guides the air blown from the cooling ventilation device so as not to leak outside, the cooling performance is further improved by an extremely simple member. be able to.

Further, since the resistor 11 is formed by folding back a plurality along the length direction, the current paths are opposite to each other (reciprocating) at the adjacent positions, and the linear portion of the resistor 11 (component 11 '). One end side 11a and the parallel part 11
In addition to being able to cancel the magnetic field between c), since the folded-back portion 11b is formed in a U shape, there is no orthogonality at the position where the direction of the current changes as compared with the prior art, and therefore, The magnetic field can be canceled even in the portion where the direction of the current changes, and the lower inductance of the resistor 11 can be realized.

When the resistor 11 is used as a quench protection device, the resistor 11 absorbs energy from the superconducting coil at the time of quenching and thermally expands, or radiates heat at the time of normal operation, so that the resistor 11 undergoes thermal contraction. .

In the present embodiment, as described above, the thin plate is formed in the corrugated shape to form the resistor 11, so that the thermal contraction generated in the resistor 11 can be absorbed by the elastic force of the thin plate itself. Since the resistor 11 is supported by the supporting means and is sandwiched from both sides, the supporting means can allow the thermal contraction of the resistor, and therefore the resistor 11 is not likely to be broken by the thermal contraction.

As the supporting means, in the illustrated embodiment, the fixing channels 1 arranged on both sides of the resistor 11 respectively.
4, a support member 15 mounted between the fixing channels 14 and supporting the bottom of the resistor 11, a fixing channel 14,
Since the resistor 14 is configured to have the bolt 16 for holding the resistor 11, the resistor 11 can be easily supported with a small number of parts.

FIG. 5 shows another embodiment of the present invention, in which the same parts as those in FIG. 2 are designated by the same reference numerals. In the above-described embodiment, the resistor 11 is formed by connecting a plurality of corrugated components 11 ', but in the present embodiment, one thin plate is corrugated and continuous. It is formed by

Therefore, according to this embodiment, the resistor 11
Is formed by folding back one thin plate along the length direction, the work of welding the component parts 11 'to each other is completely unnecessary as compared with the above-mentioned embodiment, and as a result, the number of manufacturing steps can be reduced, resulting in the resistance body. Can be made easier and cheaper.

[0035]

As described above, according to the present invention, according to the present invention, click
To protect the superconducting coil when the ench
A resistor that absorbs the energy stored in the conductive coil
And from particular formed by folding the wave shape, it is possible to omit of installation space for the resistor, it is possible to increase the degree of freedom in shape, also with respect to resistance to blast in one direction Since the resistor is cooled, the fluidity of ventilation can be enhanced, the cooling performance can be improved, and the folded portion of the resistor is formed in a U shape so that it can be orthogonalized at the position where the current direction changes. There is an effect that the lower inductance of the resistor can be realized.

In particular, according to the second aspect, since the resistor is formed by one thin plate, all the welding work becomes unnecessary, and in addition to the above effects, there is an effect that the manufacturing is easy and the cost is low. Further , according to claim 3, since the support means is configured to mount the resistor and sandwich the resistor from both sides, even if the resistor contracts due to heat, it is possible to allow it and the contraction occurs. There is an effect that there is no fear of damage.

[Brief description of drawings]

FIG. 1 is a superconducting circuit diagram to which a resistor according to the present invention is applied.

FIG. 2 is a perspective view showing an embodiment of a resistor of the present invention.

FIG. 3 is a perspective view showing a part of a resistor used in a resistor.

FIG. 4 is an explanatory view of a vertical cross section showing the same resistor.

FIG. 5 is a perspective view showing another embodiment of the resistor of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Excitation power supply, 3 ... DC circuit breaker, 4 ... Energy absorption protective resistor, 11 ... Resistor, 11b ... U-shaped folded-back part, 12A, 12B ... Terminal, 14-16 ... Support means,
18, 19 ... Cooling ventilation means, 20 ... Fan guide.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 54-115440 (JP, A) JP 64-13701 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 39/04 ZAA H01C 1/08

Claims (3)

(57) [Claims] At 1. A normally energized current from the excitation power supply to the superconducting coil, and during quenching, and interrupting means for interrupting the power supply from the excitation power supply for the superconducting coils are connected in parallel to said shut-off means, and resistor Body, supporting means for supporting the resistor body, and cooling means for cooling the resistor body by ventilating the resistor body in one direction respectively, and at the time of quenching, the energy stored in the superconducting coil is absorbed and the superconducting coil body is absorbed. A quench protection device comprising a resistor for protecting the coil, and a resistor of the resistor is formed by folding a thin plate in a wave shape along a length direction. 2. An interrupting means for normally energizing a superconducting coil with a current from an exciting power source and interrupting an energizing current from the exciting power source to the superconducting coil during a quench, and a resistor connected in parallel to the interrupting means. Body, supporting means for supporting the resistor body, and cooling means for cooling the resistor body by ventilating the resistor body in one direction respectively, and at the time of quenching, the energy stored in the superconducting coil is absorbed and the superconducting coil body is absorbed. A resistor for protecting the coil, wherein the resistor body is formed by folding a thin plate of one piece along the length direction in a wave shape and forming the folded portion in a U shape. And quench protection device. 3. The contract means characterized in that the support means is configured to mount a resistor and to sandwich the resistor from both sides.
The quench protection device according to claim 1 or 2 .