JP2015176990A - Superconducting coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting coil device that is able to sufficiently cool a superconducting coil while preventing a decrease in the superconducting characteristics of the superconducting coil.SOLUTION: A superconducting coil device, which cools a superconducting coil 21 stored in a vacuum container by conducting cold heat from a refrigerator, comprises: a coil cooling plate 22 thermally directly connected to the superconducting coil 21; a solid heat insulation part 24 covering the periphery of the superconducting coil 21 and thermally directly connected to the coil cooling plate 22; a coil case 25 surrounding the periphery of the solid insulation part 24; a heat exchange plate thermally connecting the refrigerator and coil case 25; and a current introducing terminal electrically connected to the superconducting coil 21. The superconducting coil 21 and solid insulation part 24 are not in physical contact with each other and are indirectly connected via the coil cooling plate 22 directly connected to the superconducting coil 21 and solid insulation part 24.

Description

  The present invention relates to a superconducting coil device.

  The conduction cooling type superconducting coil device is easier to handle than the immersion cooling type superconducting coil device using liquid helium or the like, and has an advantage that the operating temperature can be set appropriately. However, when the refrigerator is stopped, there is a problem that heat enters the superconducting coil from the room temperature portion through the support material or the refrigerator, the coil temperature rises, and it is immediately quenched.

  Therefore, a method for suppressing the temperature rise of the superconducting coil when the refrigerator is stopped by covering the outer periphery of the superconducting coil with a resin layer and covering the periphery with a solid heat insulating part is disclosed in, for example, Japanese Patent Application Laid-Open No. 2013-207018. (Patent Document 1) and the like.

JP2013-207018A

  In the method described in Patent Document 1 and the like, it is necessary to bond the superconducting coil and the solid heat insulating portion in order to cover the outer peripheral portion of the superconducting coil with the resin layer and cover the periphery with the solid heat insulating portion.

  However, if the superconducting coil and the solid heat insulating part are bonded, a large thermal stress is locally generated during cooling, which may exceed the allowable stress of the superconducting wire. When the locally generated thermal stress exceeds the allowable stress of the superconducting wire, there is a problem that the superconducting characteristics of the superconducting coil are deteriorated.

  On the other hand, considering this problem, it is conceivable to weaken the adhesive force between the superconducting coil and the solid heat insulating portion. However, if the adhesive force between the superconducting coil and the solid heat insulating part is weakened, a heat transfer path between the superconducting coil and the solid heat insulating part is not secured, and there is a problem that the superconducting coil is not sufficiently cooled.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a superconducting coil device capable of sufficiently cooling a superconducting coil while preventing a deterioration in superconducting characteristics of the superconducting coil.

  A superconducting coil device according to an embodiment of the present invention is a superconducting coil device that cools a superconducting coil accommodated in a vacuum vessel by conducting cold heat from a refrigerator in order to solve the above-described problems, and the superconducting coil A coil cooling plate that is thermally connected directly, a solid heat insulating part that covers the periphery of the superconducting coil and that is thermally connected directly to the coil cooling plate, a coil case that covers the periphery of the solid heat insulating part, and A heat transfer plate that thermally connects the refrigerator and the coil case; and a current introduction terminal that is electrically connected to the superconducting coil, wherein the superconducting coil and the solid heat insulating portion are physically Is non-adherent and thermally connected indirectly via the coil cooling plate directly connected to each of the superconducting coil and the solid heat insulating part.

  According to the present invention, it is possible to sufficiently cool the superconducting coil while preventing deterioration of the superconducting characteristics of the superconducting coil.

The block diagram which shows schematically the superconducting coil apparatus which concerns on the 1st Embodiment of this invention. The superconducting coil in the superconducting coil apparatus which concerns on the 1st Embodiment of this invention, and the expanded partial sectional view of the periphery. The lineblock diagram showing roughly the modification of the superconducting coil device concerning a 1st embodiment of the present invention. It is explanatory drawing explaining the structure of the superconducting coil in the superconducting coil apparatus which concerns on the 2nd Embodiment of this invention, and its periphery, (A) is IV (A) -IV (A) sectional drawing, (B) is superconducting. The expanded sectional view of a coil and its periphery.

  Hereinafter, a superconducting coil device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, words indicating directions such as up, down, left, and right are based on the illustrated state or the normal use state.

[First Embodiment]
FIG. 1 is a configuration diagram schematically showing a superconducting coil device 10A which is an example of a superconducting coil device according to the first embodiment of the present invention. FIG. 2 is an enlarged partial cross-sectional view of the superconducting coil 21 and its periphery (superconducting coil unit 20A) in the superconducting coil device 10A. In FIG. 2, in consideration of the axial symmetry of the superconducting coil unit 20A, a longitudinal section of one half (left half) is shown, and the remaining half (right half) is not shown.

  The superconducting coil device 10A (FIG. 1) heats, for example, a multistage refrigerator 11a having a plurality of cooling stages such as two stages and the superconducting coil unit 20 (more specifically, the coil case 25 shown in FIG. 2). The heat transfer plate 12 to be electrically connected, the current introduction terminal 13 electrically connected to the superconducting coil unit 20A (more specifically, the superconducting coil 21 shown in FIG. 2), and the superconducting coil unit 20A (superconducting coil 21, A coil cooling plate 22, a releasing part 23, a solid heat insulating part 24, and a coil case 25).

  In the superconducting coil device 10A, the heat transfer plate 12 is made of a material having good heat conduction, such as copper (Cu), brass, aluminum (Al), gold (Au), silver (Ag), and the like. It is connected to the low temperature end of the machine 11a. The current introduction terminal 13 is electrically connected to a superconducting feeder 14 made of a material having good electrical conductivity such as a high-temperature superconductor and a lead electrode 15 attached to the superconducting coil 21.

  Superconducting coil unit 20 </ b> A (more specifically, coil case 25 shown in FIG. 2) is supported in vacuum container 17 via support member 16. The support member 16 is thermally anchored by the cooling stage of the multistage refrigerator 11a and the coil case 25. The entire support member 16 is incorporated in the vacuum vessel 17.

  The superconducting coil unit 20A is a unit including, for example, a superconducting coil 21, a coil cooling plate 22, a release part 23, a solid heat insulating part 24, and a coil case 25. The superconducting coil 21 includes a coil cooling plate 22 and a superconducting coil unit 20A. The release part 23 and the solid heat insulation part 24 are additionally provided and accommodated in a coil case 25.

  The coil cooling plate 22 is attached between the superconducting coil 21 and the superconducting coil 21 and is thermally connected directly to the superconducting coil 21. The coil cooling plate 22 is made of, for example, a high thermal conductor generally used as a heat sink material. An example of the high thermal conductor is, for example, a metal such as aluminum, copper, gold, or silver, or aluminum nitride that is an insulator but has a relatively high thermal conductivity.

  The release part 23 is a component subjected to a treatment for weakening the adhesive force with the epoxy resin. For example, in the superconducting coil unit 20 </ b> A, the release portion 23 is provided between the superconducting coil 21 and the coil cooling plate 22.

  The release part 23 is, for example, a fluororesin tape, polytetrafluoroethylene resin such as Teflon (registered trademark) resin, polyimide amide resin, paraffin, grease, It is formed by performing either one of adhesion and application using at least one selected from silicon oil as a release material.

  The solid heat insulating portion 24 mainly has a function as a heat insulating material. For example, the heat resistance including a resin such as an epoxy resin or fiber reinforced plastic (FRP) is relatively large (the heat conductivity is high). Low) material. The solid heat insulating portion 24 covers at least a part (entire outer periphery or part) of the superconducting coil 21 but is not physically in contact with the superconducting coil 21 and is physically in contact with the coil cooling plate 22. .

  Therefore, although the solid heat insulating part 24 is directly connected to the coil cooling plate 22 thermally, it is not directly connected to the superconducting coil 21. The solid heat insulation part 24 and the superconducting coil 21 are connected (indirectly connected) via a coil cooling plate 22 in which the solid heat insulation part 24 and the superconducting coil 21 are in physical contact with each other.

  The coil case 25 has a function of shielding radiation to the superconducting coil 21 in the vacuum vessel 17. For example, aluminum, stainless steel, a composite material of aluminum and stainless steel, or aluminum and fiber reinforced plastic are used in the thickness direction. The material is composed of a material having a relatively low thermal resistance (high thermal conductivity) such as a composite material.

  The coil case 25 covers the periphery of the solid heat insulating portion 24. That is, the coil case 25 covers the periphery of the superconducting coil 21 whose periphery is covered with the solid heat insulating portion 24. The coil case 25 is thermally directly connected to the solid heat insulating portion 24.

  As described above, the superconducting coil device 10A is configured without physically connecting the superconducting coil 21 and the solid heat insulating portion 24 (in an unbonded state). On the other hand, the solid heat insulating part 24 covers the periphery of the superconducting coil 21 to which the coil cooling plate 22 is attached. The superconducting coil 21 and the solid heat insulating part 24 are not thermally connected directly, and the coil cooling plate 22 is not connected directly. It is indirectly connected via

  In the superconducting coil device 10 </ b> A having the above-described configuration, the superconducting coil 21 and the solid heat insulating part 24 are thermally indirectly connected via the coil cooling plate 22, and hence the adhesion between the superconducting coil 21 and the solid heat insulating part 24. Even if the force is weakened, it is conventionally possible to secure a heat transfer path between the superconducting coil 21 and the solid heat insulating portion 24 that is not secured when the adhesive force between the superconductive coil 21 and the solid heat insulating portion 24 is weakened. it can. Therefore, even if the adhesive force between the superconducting coil 21 and the solid heat insulating portion 24 is weakened, the superconducting coil 21 can be sufficiently cooled.

  Further, by providing the release portion 23 by, for example, releasing the outer peripheral surface of the superconducting coil 21, in the superconducting coil device 10 </ b> A, the adhesive force between the superconducting coil 21 and the solid heat insulating portion 24 can be weakened. Therefore, an increase in the thermal stress of the superconducting coil 21 during cooling can be suppressed. Therefore, it is possible to prevent the superconducting characteristics of the superconducting coil 21 from being lowered, and the stability of the superconducting coil device 10A can be further improved.

  The superconducting coil device 10A described above is not limited to the example shown in FIG. 1, and various modifications such as omission, addition, and replacement can be made.

  FIG. 3 is a configuration diagram schematically showing a modification of the superconducting coil device 10A which is an example of the superconducting coil device according to the first embodiment of the present invention.

  For example, the superconducting coil device 10A shown in FIG. 1 is an example in which a multistage refrigerator 11a is used for cooling the superconducting coil 21, but like the superconducting coil device 10A shown in FIG. A single-stage refrigerator 11b having a single cooling stage can be used instead of the machine 11a.

  When the single-stage refrigerator 11b is used for cooling the superconducting coil 21, the refrigerating capacity in the vicinity of 30 Kelvin (30K) is higher than that of the multistage refrigerator 11a, and therefore there is an advantage that the superconducting coil 21 can be efficiently cooled. . Further, the single-stage refrigerator 11b has a simpler structure than the multi-stage refrigerator 11a, and therefore has an advantage that the structure of the superconducting coil device 10A as a whole can be simplified.

[Second Embodiment]
FIG. 4 is an explanatory diagram illustrating the configuration of the superconducting coil 21 and its periphery (superconducting coil unit 20B) in the superconducting coil device 10B which is an example of the superconducting coil device according to the second embodiment of the present invention. (A) is IV (A) -IV (A) sectional drawing, FIG.4 (B) is an expansion longitudinal cross-sectional view of the superconducting coil unit 20B.

  The superconducting coil device 10B is different from the superconducting coil device 10A in that it includes a superconducting coil unit 20B instead of the superconducting coil unit 20A, but is not substantially different in other points. Therefore, constituent elements that are not substantially different from the superconducting coil device 10A are denoted by the same reference numerals, and redundant description is omitted.

  The superconducting coil unit 20B further includes a reinforcing case 27 that accommodates the superconducting coil 21 with respect to the superconducting coil unit 20A. The reinforcing case 27 is made of, for example, an insulator such as fiber reinforced plastic (FRP), or a metal such as stainless steel or aluminum. In the superconducting coil unit 20B, the solid heat insulating part 24 covers the periphery of the superconducting coil 21 accommodated in the reinforcing case 27. That is, the superconducting coil 21 covers the solid heat insulating part 24 via the reinforcing case 27. It has been broken.

  The reinforcing case 27 is configured to be able to accommodate the superconducting coil 21 in a state where the coil cooling plate 22 attached to the superconducting coil 21 is pulled out of the reinforcing case 27. Therefore, in the superconducting coil unit 20 </ b> B, when the superconducting coil 21 is accommodated in the reinforcing case 27, the coil cooling plate 22 attached to the superconducting coil 21 is drawn out of the reinforcing case 27.

  Thus, in the superconducting coil unit 20B, the superconducting coil 21 can be accommodated in a state in which the coil cooling plate 22 attached to the superconducting coil 21 is pulled out of the reinforcing case 27. Therefore, as with the superconducting coil unit 20A, solid heat insulation is possible. The coil cooling plate 22 can be physically contacted without physically contacting the portion 24 with the superconducting coil 21. Therefore, the superconducting coil device 10B has the same effect as the superconducting coil device 10A.

  In addition, the inside (inner surface) of the reinforcing case 27 can be further increased in strength by being impregnated with resin. In addition, since the outer peripheral surface of the superconducting coil 21 is subjected to a release treatment, it is possible to prevent the superconducting coil 21 from being bonded to the inner surface of the reinforcing case 27 even if the inside of the reinforcing case 27 is impregnated with resin. it can.

  Further, the soaking plate made of a material having a higher thermal conductivity than that of the reinforcing case 27, such as high purity (purity 99% or more) aluminum, copper, gold, silver or the like. By attaching 29, the superconducting coil 21 can be efficiently cooled.

  In the superconducting coil device 10B configured as described above, since the superconducting coil 21 and the solid heat insulating portion 24 are thermally indirectly connected via the coil cooling plate 22 as in the superconducting coil device 10A, Even if the adhesive force between the solid heat insulating portion 24 is weakened, a heat transfer path between the superconducting coil 21 and the solid heat insulating portion 24 can be secured. Therefore, even if the adhesive force between the superconducting coil 21 and the solid heat insulating portion 24 is weakened, the superconducting coil 21 can be sufficiently cooled.

  Further, by providing the release part 23, the superconducting coil device 10B can weaken the adhesive force between the superconducting coil 21 and the solid heat insulating part 24, so that the thermal stress of the superconducting coil 21 during cooling can be increased. Can be suppressed. Therefore, it is possible to prevent the superconducting characteristics of the superconducting coil 21 from being deteriorated, and the stability of the superconducting coil device 10B can be further improved.

  Furthermore, since the superconducting coil device 10B is further provided with a reinforcing case 27 with respect to the superconducting coil device 10A, the superconducting coil 21 can be securely held, and the superconducting coil 21 (superconducting coil unit 20B) can be held. The mechanical strength can be further improved.

  Further, in the superconducting coil device 10B, since the outer peripheral surface of the superconducting coil 21 is subjected to release processing, the superconducting coil 21 is bonded to the inner surface of the reinforcing case 27 even if the inside of the reinforcing case 27 is impregnated with resin. And increase in thermal stress can be prevented.

  Furthermore, in the superconducting coil device 10B, the reinforcing case 27 that accommodates the superconducting coil 21 is easy to ensure dimensional accuracy, and therefore the solid heat insulating portion 24 that covers the periphery thereof can be arranged with high accuracy.

  The superconducting coil device 10B described above is an example (FIG. 4) in which the heat equalizing plate 29 is attached to the outer surface of the reinforcing case 27, but the mounting position of the heat equalizing plate 29 may be on the surface of the reinforcing case 27. Anywhere. The soaking plate 29 is not necessarily attached to the reinforcing case 27 and can be omitted. Furthermore, the shape and the number of the soaking plates 29 are not limited to the shape and the number illustrated in FIG. For example, the heat equalizing plate 29 can be configured by a single ring extending over the entire circumference in the circumferential direction.

  As described above, according to the superconducting coil devices 10 </ b> A and 10 </ b> B, the superconducting coil 21 and the solid heat insulating part 24 are thermally indirectly connected via the coil cooling plate 22, and therefore, between the superconducting coil 21 and the solid heat insulating part 24. Even if the adhesive force is weakened, a heat transfer path between the superconducting coil 21 and the solid heat insulating portion 24 can be secured. Therefore, even if the adhesive force between the superconducting coil 21 and the solid heat insulating portion 24 is weakened, the superconducting coil 21 can be sufficiently cooled.

  Further, according to the superconducting coil devices 10A and 10B, by providing the release part 23, the adhesive force between the superconducting coil 21 and the solid heat insulating part 24 can be weakened, so that the heat of the superconducting coil 21 during cooling can be reduced. The increase in stress can be suppressed. Therefore, it is possible to prevent the superconducting characteristics of the superconducting coil 21 from being deteriorated, and the stability of the superconducting coil devices 10A and 10B can be further improved.

  Furthermore, according to the superconducting coil devices 10A and 10B, by using the single-stage refrigerator 11b, the superconducting coil 21 can be efficiently cooled and the overall structure of the device can be simplified.

  On the other hand, according to the superconducting coil device 10B, the superconducting coil device 10A is further provided with the reinforcing case 27, so that the superconducting coil 21 can be securely held, and the superconducting coil 21 (superconducting coil unit 20B) can be retained. ) Can be further improved.

  Further, according to the superconducting coil device 10B, the soaking plate 29 having a thermal conductivity higher than that of the reinforcing case 27 is attached to the reinforcing case 27, so that the temperature of the superconducting coil 21 is locally increased. Temperature rise (bias) can be prevented, and the temperature can be made uniform. Therefore, in the superconducting coil device 10B, the occurrence of local thermal stress is prevented, and the superconducting characteristics of the superconducting coil 21 are prevented from being deteriorated, so that the stability of the superconducting coil device 10B can be further improved.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be implemented in various forms other than the above-described examples in the implementation stage. The present invention can be variously omitted, added, replaced, and changed without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10A, 10B Superconducting coil device 11a Multistage refrigerator 11b Single stage refrigerator 12 Heat transfer plate 13 Current introduction terminal 14 Superconducting feeder 15 Lead electrode 16 Support member 17 Vacuum vessel 20A, 20B Superconducting coil unit 21 Superconducting coil 22 Coil cooling plate 23 Release part 24 Solid heat insulation part 25 Coil case 27 Reinforcing case 29 Heat equalizing plate

Claims (6)

A superconducting coil device that cools a superconducting coil stored in a vacuum vessel by conducting cold heat from a refrigerator,
A coil cooling plate thermally directly connected to the superconducting coil;
A solid heat insulating portion covering the periphery of the superconducting coil and thermally directly connected to the coil cooling plate;
A coil case covering the periphery of the solid heat insulating part;
A heat transfer plate that thermally connects the refrigerator and the coil case;
A current introduction terminal electrically connected to the superconducting coil;
The superconducting coil and the solid heat insulating part are physically non-bonded and thermally connected indirectly via the coil cooling plate that is directly connected to each of the superconducting coil and the solid heat insulating part. A superconducting coil device characterized by that. 2. The superconducting coil device according to claim 1, wherein a release portion that weakens the adhesive force with an epoxy resin is provided on the outer periphery of the superconducting coil. The release part is at least one selected from a fluororesin tape, a polytetrafluoroethylene resin, a polyimide amide resin, paraffin, grease, and silicone oil as a treatment for weakening the adhesive force with the epoxy resin. 3. The superconducting coil device according to claim 2, wherein the superconducting coil device is formed by performing any one of adhesion and application as a release material. The superconducting coil device according to any one of claims 1 to 3, wherein the refrigerator is a single-stage refrigerator having a single cooling stage. A reinforcing case configured to accommodate the superconducting coil in a state where the coil cooling plate is pulled out of the reinforcing case;
The superconducting coil according to any one of claims 1 to 4, wherein the superconducting coil accommodated in the reinforcing case is covered with the solid heat insulating portion via the reinforcing case. apparatus. 6. The superconducting coil device according to claim 5, wherein a soaking plate having a thermal conductivity higher than that of the reinforcing case is attached to the reinforcing case.

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