JP5504888B2 - Superconducting coil container and superconducting equipment - Google Patents

Description

  The present invention relates to a superconducting coil container and a superconducting device, and more particularly to a superconducting coil container that holds a superconducting coil inside, and a superconducting device that uses the superconducting coil container.

  In a superconducting device such as a superconducting motor using a superconducting coil, the superconducting coil is cooled using a refrigerant such as liquid nitrogen in order to pass a current through the superconducting coil. Specifically, the refrigerant is supplied into the superconducting coil container in a state where the superconducting coil is held inside the superconducting coil container.

  The superconducting coil container is usually in the form of a vacuum heat insulating container. The vacuum heat insulating container is an inner tank (inner tank) that holds the superconducting coil inside, and an outer tank (outer tank) that is arranged to surround the inner tank. ). A certain gap exists between the inner tank and the outer tank, and the gap is set in a vacuum state. In this way, the gap between the inner tank and the outer tank (a region in a vacuum state) suppresses heat transfer from the outer tank side to the inner tank side. For this reason, the cooling efficiency of the superconducting coil by a refrigerant | coolant is improved, and it is suppressed that the temperature of the said refrigerant | coolant rises with the heat which approachs from the outer side of the apparatus for superconducting coils.

  In order to supply the refrigerant into the inner tank, a refrigerant supply pipe is installed in the inner tank. This refrigerant supply pipe is a tubular member arranged so as to reach from the outside of the superconducting coil container to the region where the superconducting coil is placed (in this case, the inside of the inner tank). The refrigerant supply pipe is also preferably provided with an outer pipe so as to surround the refrigerant supply pipe, and a vacuum is provided by providing a certain gap between the outer pipe and the refrigerant supply pipe. In this way, if the refrigerant supply pipe is also in the same manner as the vacuum heat insulating container, the refrigerant flowing through the refrigerant supply pipe is heated by the gap between the outer pipe and the refrigerant supply pipe or the outer pipe. It becomes difficult to be affected.

  In this way, the superconducting coil container is configured as a vacuum heat insulating container composed of an inner tank and an outer tank, and a superconducting device having a configuration in which a refrigerant supply pipe for supplying a refrigerant to the inner tank includes an outer pipe surrounding it. For example, the apparatus currently disclosed by Unexamined-Japanese-Patent No. 2007-5573 (patent document 1) and Unexamined-Japanese-Patent No. 2000-182821 (patent document 2) can be mentioned.

  Further, when the cryogenic refrigerant flows inside the refrigerant supply pipe, the refrigerant supply pipe expands and contracts in the extending direction. In order to absorb the thermal stress applied to the supply pipe by this expansion and contraction and suppress the breakage of the supply pipe, a piping device including a supply pipe (flexible tube) that can be freely expanded and contracted in the extending direction, for example, It is disclosed in JP-A-8-219344 (Patent Document 3).

JP 2007-5573 A JP 2000-182821 A JP-A-8-219344

  The superconducting magnet device disclosed in Patent Document 1 inserts a refrigerant injection pipe into a power lead pipe and supplies the refrigerant into the refrigerant injection pipe when supplying the refrigerant into a coil container having a superconducting coil. The refrigerant is supplied into the coil container by circulating it. When the supply of the refrigerant into the coil container is completed, the refrigerant injection pipe is extracted from the power lead pipe, and the refrigerant injection pipe is not inserted into the power lead pipe during normal use or standby of the superconducting coil. If it does in this way, it will suppress that the heat | fever by external air penetrate | invades in a coil container along the direction where a refrigerant | coolant injection pipe extends at the time of normal use etc., for example. In addition, the superconducting magnet of Patent Document 2 can adjust the superconducting coil and the housing of the radiation shield that incorporates the superconducting coil to be in contact with each other using a member such as a contact plate interposed therebetween, or to be non-contacting. And In this way, the cooling efficiency inside the radiation shield in which the superconducting coil is incorporated is improved, and the penetration of heat from the outside to the inside of the radiation shield is suppressed.

  However, in any of the devices of Patent Documents 1 and 2, no consideration is given to the difference in thermal expansion between the casing of the container that holds the superconducting coil inside and a member such as a refrigerant supply pipe that is in direct contact with the container. In each of the devices of Patent Documents 1 and 2, the refrigerant supply pipe is installed only when the refrigerant is supplied to the inside of the container, or the superconducting coil and the casing of the container are in direct contact with each other. It suppresses the heat intrusion caused by the contact between them. However, when the refrigerant is supplied, the region where the refrigerant supply pipe and the container are in contact with each other is rapidly cooled from room temperature, and the container and the refrigerant supply pipe undergo thermal contraction. At this time, if they are in contact with each other, thermal stress is generated between the two due to the difference in thermal shrinkage between the two, and there is a possibility that damage such as cracks may occur at the contact portion between the two. Patent Document 3 discloses only a pipe for supplying a refrigerant, and does not describe a relationship with a container for connecting the pipe.

  The present invention has been made in view of the above problems. The purpose is to suppress the thermal stress generated between the casing of the container that holds the superconducting coil inside and the refrigerant supply pipe connected to the container, and to supply the refrigerant stably. Is to provide a container. Moreover, it is providing the superconducting apparatus using the said container for superconducting coils.

  The superconducting coil container according to the present invention includes an inner tank, an outer tank that holds the inner tank inside, a refrigerant supply pipe that reaches from the outside of the outer tank to the inside of the inner tank, and is connected to the inner tank. And an outer tube connected to the outer tub, surrounding the refrigerant supply tube outside the outer tub. The refrigerant supply pipe has an inner tank connection part and a thermal resistance movable part, and the first thermal expansion coefficient of the material constituting the inner tank connection part is the second thermal expansion coefficient of the material constituting the inner tank. 50% or more and 200% or less. The heat resistance movable part has a larger heat resistance than the region other than the heat resistance movable part in the refrigerant supply pipe, and the heat resistance movable part includes a bent part.

  Since the refrigerant supply pipe is connected to the inner tank, a superconducting coil is mounted inside the inner tank, and cooling is performed by supplying the refrigerant into the inner tank. Here, if the housing | casing and refrigerant | coolant supply pipe | tube which comprise an inner tank are mutually connected, a housing | casing and a refrigerant | coolant supply pipe | tube will heat-shrink at the time of cooling. Here, if the thermal expansion coefficients of the two are significantly different, the difference in the amount of thermal shrinkage between the two becomes large. Then, a large thermal stress is generated between the two. For this reason, for example, a crack or the like may occur starting from a portion of the housing of the inner tank that contacts the refrigerant supply pipe.

  Here, as described above, the thermal expansion coefficient (first thermal expansion coefficient) of the material constituting the portion connected to the inner tank (inner tank connection part) in the refrigerant supply pipe is the casing that constitutes the inner tank. To the thermal expansion coefficient (second thermal expansion coefficient). As a result, the difference in heat shrinkage between the two during cooling is reduced. For this reason, for example, a large thermal stress is applied to a portion where the inner tank comes into contact with the refrigerant supply pipe, and it is possible to suppress the occurrence of problems such as generation of cracks starting from the contact portion. That is, the sealing at the contacted portion can be made more reliable.

  Of the refrigerant supply pipe, a member (second member) that includes the inner tank connecting portion and is connected to the outside (outside of the inner tank) of a member (first member) made of a material having a thermal expansion coefficient close to the inner tank. Is formed with a movable portion of thermal resistance having a relatively higher thermal resistance than other regions (for example, made of a material having a relatively low thermal conductivity or having a small cross-sectional area). If the thermal resistance in the heat resistance movable part of the refrigerant supply pipe is made larger than the thermal resistance in the region other than the heat resistance movable part of the refrigerant supply pipe, heat is generated in the extending direction of the refrigerant supply pipe in the heat resistance movable part. Can be prevented from propagating. For this reason, for example, heat is propagated in the extending direction from the outside of the refrigerant supply pipe (outside of the inner tank) to the inside (inner tank side), and the heat is prevented from entering the inside of the inner tank. Can do. Therefore, if it is set as such a structure, the heat insulation effect inside an inner tank can be heightened.

  If the heat resistance movable part includes a bent part, the length of the casing of the refrigerant supply pipe in the bent part with respect to the direction in which the refrigerant supply pipe extends substantially increases. For this reason, since the external heat propagates through the inside of the casing of the refrigerant supply pipe and enters the inside of the inner tank, the distance to be propagated becomes long. Also from this, the penetration of heat into the container can be suppressed. Further, since the heat resistance movable portion has a bent portion, its length is variable in the extending direction of the refrigerant supply pipe. For this reason, even when the refrigerant supply pipe and the inner tank are thermally contracted, even if the refrigerant supply pipe is connected to a member outside the container, the displacement of the refrigerant supply pipe due to the thermal contraction can be absorbed by the heat resistance movable portion. Therefore, it is possible to suppress an excessive stress from being applied to the connection portion between the external member and the refrigerant supply pipe.

  It is preferable that the heat resistance movable part mentioned above has a bellows structure, for example. In the bellows structure, as described above, a large number of bent portions are arranged in the direction in which the refrigerant supply pipe extends, and the length along the direction in which the casing of the refrigerant supply pipe extends in the region (the creepage length). Is substantially longer. Further, the length of the refrigerant supply pipe is variable along the direction in which the refrigerant supply pipe extends due to the large number of bent portions. Therefore, if the bellows structure is used, it is possible to suppress the external heat from being propagated into the inner tank through the refrigerant supply pipe, and to absorb the displacement due to the thermal contraction of the refrigerant supply pipe and the inner tank.

  In the superconducting coil container, it is preferable that the thickness of the refrigerant supply pipe in the bellows structure is thinner than the thickness of the region other than the bellows structure of the refrigerant supply pipe. If it does in this way, the cross-sectional area which cross | intersects the extending direction of a refrigerant | coolant supply pipe | tube of the housing | casing of the refrigerant | coolant supply pipe | tube in a bellows structure will become small. Therefore, the thermal resistance in the bellows structure portion can be further increased. In other words, the propagation of heat in the bellows structure can be further suppressed.

A container for the superconducting coil, the inner tub connections iron, nickel, preferably composed of a material containing at least one selected from cobalt. The thermal expansion coefficient of these materials is 50% or more and 200% or less of the thermal expansion coefficient of the material constituting the inner tank. Therefore, as described above, if a material including these materials is used for the inner tank connecting portion, the difference in thermal contraction between the inner tank and the refrigerant supply pipe in the inner tank connecting portion can be reduced.

  The superconducting device including the superconducting coil container described above and the superconducting coil disposed inside the superconducting coil container suppresses damage to the container at the connection portion between the container and the refrigerant supply pipe as described above. And the penetration | invasion of the heat from the exterior to the inside of a container can be suppressed. Therefore, a high-quality superconducting device with high cooling efficiency inside the inner tank can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the damage resulting from the difference in a thermal expansion coefficient can be suppressed, and the high quality superconducting coil container which can suppress the heat penetration | invasion to the inside of a container can be provided. As a result, a high-quality superconducting device using the superconducting coil container can be provided.

It is a schematic diagram which shows the state of the external appearance of the superconducting apparatus which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing in line segment II-II of FIG. FIG. 3 is a schematic perspective view of the rotor of FIGS. 1 and 2. FIG. 3 is a schematic perspective view of the stator of FIGS. 1 and 2. It is a schematic perspective view which shows the structure of the inner tank container by which a superconducting coil is hold | maintained inside. It is a schematic perspective view which shows the structure of the outer tank container which surrounds the inner tank container of FIG. It is a schematic perspective view explaining the manufacturing process of the inner tank container of FIG. It is an enlarged view of the inner tank connection part which is the principal part of FIG. It is a schematic sectional drawing in line segment IX-IX of FIG. It is a schematic perspective view explaining the manufacturing process of the outer tank container of FIG. FIG. 11 is a schematic perspective view illustrating a manufacturing process of the outer tank container of FIG. 6 following FIG. 10. It is an enlarged view of the outer tank connection part which is the principal part of FIG. It is a schematic perspective view explaining the manufacturing process of the outer tank container of FIG. 6 following FIG. It is a schematic sectional drawing in line segment XIV-XIV of FIG. FIG. 15 is an enlarged schematic diagram of a region “XV” surrounded by a round dotted line in FIG. 14. It is an expansion schematic diagram which shows the aspect of the 1st modification of the thermal resistance movable part in FIG. It is an expansion schematic diagram which shows the aspect of the 2nd modification of the thermal resistance movable part in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, elements having the same function are denoted by the same reference numerals, and the description thereof will not be repeated unless particularly necessary.

  An example of the superconducting device according to the present embodiment is a superconducting motor 100 shown in FIG. Superconducting motor 100 includes a rotor 30 used as a rotor and a stator 20 used as a stator. The superconducting motor 100 of FIG. 1 is a schematic diagram showing a schematic structure, but only a part of the members constituting the rotor 30 is shown for easy understanding of the drawing, and the members constituting the stator 20 are not shown. Yes. Each member constituting the rotor 30 and the stator 20 is specifically illustrated by the cross-sectional view of FIG. 2 and FIGS. The superconducting motor 100 will be described below with reference to FIGS. 1 to 6 as appropriate.

  The rotor 30 of the superconducting motor 100 causes a current to flow from outside to the rotor core 13 around which the superconducting wire is wound as the superconducting coil 10, and causes the rotor core 13 to be magnetized according to the direction of the current. The superconducting coil 10 is preferably in the form of a racetrack coil as shown in FIGS. 1, 3, and 4, for example. As for the stator 20, magnetism is generated in the stator core 23 according to the direction of the current flowing through the superconducting coil 10 around the stator core 23. The rotor 30 is rotated in the direction along the periphery of the rotor shaft 16 by utilizing the attraction and repulsion between the rotor core 13 and the stator core 23 due to magnetism. The rotation of the rotor 30 is propagated to the outside from the output shaft 18 connected to a load that outputs the rotation of the rotor 30. The rotation of the output shaft 18 is supported by the bearing 35.

  Here, since the superconducting coil 10 is composed of a superconducting wire, it needs to be cooled with a refrigerant 17 such as liquid nitrogen in order to operate it. Therefore, the superconducting coil 10 is held inside the container. By supplying the refrigerant 17 to the inside of the container, the superconducting coil 10 is cooled to be usable.

  The container here is a superconducting coil container that houses the superconducting coil 10. As shown in FIG. 2, the superconducting coil container includes an inner tank container 50 (inner tank) that directly holds the superconducting coil 10 inside, and an outer tank container 60 that is disposed so as to surround the outer periphery of the inner tank container 50 ( Outer tank). The inner tank container 50 and the outer tank container 60 are provided in each superconducting coil 10 of the rotor 30 and the stator 20. The inner tank container 50 and the outer tank container 60 are not shown in FIGS.

  Since the container includes the inner tank container 50, the superconducting coil 10 can be cooled and stably operated. Moreover, since the said container is provided with the outer tank container 60, it has the effect | action as a heat insulation container which suppresses that the inner tank container 50 holding a refrigerant | coolant touches the external air which is room temperature.

  Therefore, it is preferable that the inner tank container 50 and the outer tank container 60 are made of a material excellent in heat insulation. As an example, these are preferably formed of FRP (fiber reinforced plastic). Since FRP has very high strength and heat insulation properties, the temperature difference between the inside and outside of the container, the damage caused by the thermal stress due to the temperature difference inside the container between when the superconducting motor 100 is used and when it is not used, The deterioration of the cooling efficiency of the superconducting coil 10 can be suppressed. However, instead of FRP, for example, filler-containing plastics or ceramics may be used as the inner tank container 50 and the outer tank container 60.

  FIGS. 5 and 6 show an inner tank container and an outer tank container used for the stator 20 as an example. As shown in FIG. 5, the inner tank container 50 is formed of, for example, an FRP housing having a cylindrical shape. The cylindrical portion of the inner tank container 50 has two cylindrical casings, an inner tank container outer casing 51 and an inner tank container inner casing 52, whose circular centers as the bottom surfaces of these cylindrical shapes are substantially coincident with each other. Arranged in a concentric circle. A region sandwiched between the inner tank container outer casing 51 and the inner tank container inner casing 52 is an area where the superconducting coil 10 is placed. In order for the stator core 23 and the rotor core 13 to pass through the hollow region of the superconducting coil 10, an opening 53 is provided on the side surfaces (side portions having a cylindrical shape) of the inner tank container outer casing 51 and the inner tank container inner casing 52. Is formed. In other words, the hollow portion of the superconducting coil 10, the stator core 23, and the rotor core 13 are disposed in each of the plurality of openings 53, and the superconducting wire of the adjacent superconducting coil 10 is disposed in a region sandwiched between the adjacent openings 53. It becomes.

  As shown in FIG. 5, the opening 53 is formed by forming, for example, a rectangular hole on both side surfaces of the inner tank container outer casing 51 and the inner tank container inner casing 52, so that the inner tank container outer casing is formed. From the body 51 to the inner tank container inner housing | casing 52, it was formed so that it might penetrate in the direction which cross | intersects a side surface. However, for example, when a rectangular hole is formed in only one of the inner tank container outer casing 51 and the inner tank container inner casing 52, for example, when viewed from the outside (inside) of the side surface of the inner tank container 50 In addition, the opening 53 may have a concave shape.

  The edge of the opening 53 is closed by the FRP as the opening side surface 54. Further, end casings 55 and 56 made of FRP having a flange shape are also arranged near the bottom surfaces (cylindrical ends) of the inner tank container outer casing 51 and the inner tank container inner casing 52. By the above, the area | region pinched | interposed into the inner tank container outer housing | casing 51 and the inner tank container inner housing | casing 52 turns into sealed space, and makes the aspect as the inner tank container 50. FIG. Here, for example, a refrigerant supply pipe and a refrigerant discharge pipe for supplying and discharging the refrigerant 17 such as liquid nitrogen (see FIG. 2) are connected. As shown in FIG. 5, two tubular members that circulate the refrigerant protrude from the end housing 55. One of these is a refrigerant supply pipe for supplying the refrigerant 17 to the inside of the inner tank container 50, and the other one is a refrigerant supply pipe for discharging the refrigerant 17 from the inside of the inner tank container 50. . However, since both have the same structure, both are here called a refrigerant supply pipe.

  The refrigerant supply pipe 1 has an inner tank connection part 2 and a refrigerant introduction part 3. Together, the refrigerant supply pipe 1 extends from the outside of the outer tank container 60 to the inside of the inner tank container 50, that is, from the room temperature region to the cryogenic region during use. Even when the refrigerant supply pipe 1 is a member for discharging the refrigerant 17, the member connected to the outside of the inner tank connection portion 2 (as viewed from the inner tank container 50) is referred to as the refrigerant introduction portion 3 here. I will decide.

  The inner tank connecting portion 2 is disposed so as to be connected to the outer side (end housing 55 or the like) of the inner tank container 50 in particular. That is, the inner tank connection part 2 is disposed so as to reach the inside of the inner tank container 50 while being in contact with the FRP constituting the inner tank container 50. For this reason, it is preferable that the inner tank connection part 2 consists of material with a comparatively small difference of a thermal expansion coefficient with FRP of the inner tank container 50. FIG. In this way, even when the inner tank container 50 and the inner tank connection portion 2 are cooled from room temperature to a cryogenic temperature when the refrigerant 17 is supplied to the inside of the inner tank container 50, the inner tank container 50 and the inner tank that are generated by the cooling are used. The difference in the amount of thermal contraction with the tank connecting portion 2 is relatively small. For this reason, in the area | region where the inner tank container 50 and the inner tank connection part 2 contact, the big thermal stress generate | occur | produces by the difference in the amount of thermal shrinkage, Furthermore, the inner tank container 50 is damaged by the said thermal stress, etc. Can be prevented from occurring. That is, the sealing in the region where the inner tank container 50 and the inner tank connection portion 2 are connected can be made more reliable.

  Specifically, the thermal expansion coefficient of the inner tank connecting portion 2 is preferably 50% or more and 200% or less of the thermal expansion coefficient of the FRP constituting the inner tank container 50. Here, the thermal expansion coefficient refers to the value of the thermal expansion coefficient within a temperature range of 200 ° C. to 25 ° C. below freezing point. As a material satisfying the above-described thermal expansion coefficient, for example, when the inner tank container 50 is made of FRP, a material made of an alloy in which nickel and cobalt are mixed with iron is used as the material of the inner tank connection portion 2. preferable.

  An alloy in which nickel and cobalt are mixed with iron is a material having a thermal expansion coefficient close to that of FRP among metals. For this reason, the inner tank connection part 2 which consists of an alloy which mix | blended nickel and cobalt with iron can make the amount of thermal shrinkage at the time of cooling equivalent to the inner tank container 50 made from FRP, and is between the inner tank containers 50. Generation | occurrence | production of a big thermal stress can be suppressed. In addition, when the material which comprises the inner tank container 50 changes, the material of the inner tank connection part 2 can be adjusted by adjusting the content rate of nickel. This is because the thermal expansion coefficient of the alloy can be adjusted by adjusting the nickel content.

  The refrigerant introduction part 3 connected to the outside of the inner tank connection part 2 when viewed from the inner tank container 50 is closest to the inlet of the refrigerant 17 to the refrigerant supply pipe 1 or the outlet of the refrigerant 17 from the refrigerant supply pipe 1. It is a member constituting the region. For this reason, the refrigerant introduction part 3 is disposed so as to extend to a room temperature environment outside the inner tank container 50 and the outer tank container 60. In the refrigerant introduction part 3, the region on the side connected to the inner tank connection part 2 has a cross-sectional area (thickness) of the flow path of the refrigerant 17 in a cross section intersecting with the direction in which the refrigerant supply pipe 1 extends. Although it is substantially equal to the connection part 2, the region opposite to the inner tank connection part 2 has a larger cross-sectional area (thickness) of the flow path in the cross section intersecting the extending direction than the inner tank connection part 2. (Thick). This is to satisfactorily match the thickness of the outer tube connected to the outer tank container 60 described later. However, the thickness of the refrigerant introduction part 3 may be substantially equal to that of the inner tank connection part 2.

  In the refrigerant introduction part 3 of FIG. 5, the heat resistance movable part 4 is formed in a region thicker than the inner tank connection part 2. Of the refrigerant introduction part 3, the region other than the heat resistance movable part 4 extends linearly with respect to the direction in which the refrigerant 17 flows. However, the heat resistance movable part 4 is configured to include a bent part in the direction in which the refrigerant 17 flows. That is, the heat resistance movable part 4 normally includes a plurality of bent parts that bend so that the cross-sectional area of the flow path of the refrigerant 17 repeatedly increases or decreases in the direction in which the refrigerant 17 flows. In other words, for example, the heat resistance movable part 4 preferably has a bellows structure. Here, the bellows structure is a structure in which a cylindrical structure constituting the heat resistance movable portion 4 is usually formed by repeating a mountain fold and a valley fold on the surface of the cylinder a plurality of times.

  When the superconducting motor 100 is used, the inside of the inner tank container 50 is cooled to a cryogenic temperature by the refrigerant 17, whereas the superconducting motor 100 is placed in a room temperature environment. Can cause a large temperature difference between one end (the region disposed in the inner tank container 50 of the inner tank connection part 2) and the other end (the refrigerant introduction part 3) in the extending direction. . For this reason, heat propagates through the inside of the cylindrical structure of the refrigerant supply pipe 1 from the high temperature refrigerant introduction part 3 side toward the low temperature inner tank connection part 2 side. At this time, the structure has a resistance value (thermal resistance) corresponding to its shape.

  Since the heat resistance movable part 4 includes a bent part such as a bellows structure, the heat resistance of the refrigerant introduction part 3 (refrigerant supply pipe 1) is larger than that of the region extending linearly. For this reason, since the refrigerant introduction part 3 includes the thermal resistance movable part 4, for example, the thermal resistance increases compared to a case where the refrigerant resistance movable part 4 is not included. Accordingly, it is possible to suppress the occurrence of problems such as the temperature of the inside of the inner tank container 50 becoming high due to heat transmitted through the refrigerant supply pipe 1 or the evaporation of the refrigerant 17 inside the inner tank container 50.

  Moreover, since the heat resistance movable part 4 includes the bent part, the refrigerant introduction part 3 (refrigerant supply pipe 1) has a long length along the direction in which the structure extends. In other words, especially in the bent part, considering the length along the bent of the structure, the length of the refrigerant introduction part 3 (refrigerant supply pipe 1) does not include the bent part and the structure extends linearly. It becomes longer than the case where it exists. Also from this, the refrigerant introduction part 3 includes the thermal resistance movable part 4, so that the thermal resistance is increased as compared with, for example, a case where the thermal resistance movable part is not included. This is because the length along the direction in which the structure extends in the bent portion is substantially increased, and therefore the distance through which heat should propagate along the direction in which the refrigerant 17 flows is increased in the structure. Because. Propagation of heat is suppressed from the refrigerant introduction part 3 to the inner tank connection part 2 (inside the inner tank container 50) by an amount corresponding to an increase in the distance to which heat should propagate. Further, the displacement caused by the temperature change in the extending direction of the refrigerant introduction part 3 can be absorbed by the thermal resistance movable part 4.

  Since the refrigerant introduction part 3 includes the heat resistance movable part 4 such as the above-described bellows structure, it is preferable that the refrigerant introduction part 3 is made of a stainless material such as SUS316 or SUS304 in order to facilitate the processing of the bent part. If it does in this way, the connection with the inner tank connection part 2 which consists of an alloy of iron, nickel, and cobalt mentioned above will become easy. In addition, when the material which comprises the inner tank container 50 and the inner tank connection part 2 changes, the material of the refrigerant | coolant introduction part 3 can be adjusted by adjusting the content rate of nickel. This is because the thermal expansion coefficient of the alloy can be adjusted by adjusting the nickel content.

  On the other hand, the outer tank container 60 as the heat insulating container is disposed so as to surround the outer side of the inner tank container 50 as described above. Specifically, as shown in FIG. 2, an outer tub container outer casing 61 is placed outside the inner tub container outer casing 51 of the inner tub container 50 so as to face the inner tub container outer casing 51. The outer tank container inner casing 62 is placed inside the inner tank container inner casing 52 so as to face the inner tank container inner casing 52. The inner tank container 50 is placed in a region sandwiched between the outer tank container outer casing 61 and the outer tank container inner casing 62 (that is, inside the outer tank container 60). As shown in FIG. 6, a plurality of openings 63 are also formed in the outer tub container outer casing 61 and the outer tub container inner casing 62, and are arranged so as to overlap with the openings 53. In this manner, the hollow region of the superconducting coil 10, the stator core 23, and the rotor core 13 are arranged in the region where the opening 63 and the opening 53 are superimposed (see FIG. 2). An opening side surface 64 is also present at the edge of the opening 63, and the end housings 65 and 66 are arranged, whereby the inside of the outer tank container 60 forms a sealed space.

  That is, the circular diameter formed by the bottom surface of each container is the outer tub container outer casing 61, the inner tub container outer casing 51, the inner tub container inner casing 52, and the outer tub container inner casing 62 in the descending order. The part 63 is smaller than the opening 53.

  The inner tank container 50 and the outer tank container 60 are arranged so as not to contact each other with respect to the circular radial direction formed by the respective bottom surfaces. That is, as shown in FIG. 2, for example, there is a certain radial gap between the inner tank container outer casing 51 of the inner tank container 50 and the outer tank container outer casing 61 of the outer tank container 60. The same applies to the inner tank container inner casing 52 of the inner tank container 50 and the outer tank container inner casing 62 of the outer tank container 60. That is, the gap exists, for example, as the gap 21 shown in FIG. 2 and surrounds the outer periphery of the inner tank container 50. The presence of the gap 21 increases the efficiency of cooling the inside of the inner tank container 50 by the refrigerant 17 and suppresses the temperature inside the inner tank container 50 from being influenced by the room temperature outside the outer tank container 60, for example. doing. For this reason, it can be said that the outer tank container 60 acts as a heat insulating material that facilitates temperature control inside the inner tank container 50.

  And the outer pipe | tube 6 shown in FIG. 6 is arrange | positioned at the outer tank container 60 so that the outer side of the refrigerant | coolant supply pipe | tube 1 may be covered. Similarly to the refrigerant supply pipe 1, two of the outer pipes 6 protrude from the end housing 65, and one of the two pipes extends outside the refrigerant supply pipe 1 that supplies the refrigerant 17 into the inner tank container 50. The other is the one that surrounds the outside of the refrigerant supply pipe 1 that discharges the refrigerant 17 from the inside of the inner tank container 50, and both are hereinafter referred to as the outer pipe 6.

  Note that the opening 63 shown in FIG. 6 is similar to the opening 53 in that, for example, a rectangular hole is formed on both sides of the outer tub container outer casing 61 and the outer tub container inner casing 62, thereby It may be formed so as to penetrate from the tank container outer casing 61 to the outer tank container inner casing 62 in a direction intersecting the side surface. However, for example, when a rectangular hole is formed in only one of the outer tub container outer casing 61 and the outer tub container inner casing 62, for example, when viewed from the outside (inside) of the side surface of the outer tub container 60 In addition, the opening 63 may have a concave shape.

  As shown in FIG. 6, the outer tube 6 includes an outer tube body 7 and an external connection flange 9. The outer pipe main body 7 is preferably formed with a heat resistance movable part 8 similar to the refrigerant introduction part 3 (refrigerant supply pipe 1) described above. That is, similarly to the heat resistance movable part 4, the heat resistance movable part 8 has a structure including a bent portion such as a bellows structure. By including such a structure, the substantial length of the structure constituting the outer tube main body 7 in the direction in which the outer tube 6 extends increases, so that the outer tube main body 7 moves toward the inner tank container 50 side. Heat transfer is suppressed. That is, it is possible to suppress the temperature inside the inner tank container 50 from rising, and to prevent the occurrence of problems such as evaporation of the refrigerant 17 inside the inner tank container 50. Further, the displacement caused by the temperature change in the extending direction of the outer tube 6 can be absorbed by the heat resistance movable portion 8.

  Next, the outline of the manufacturing method of the inner tank container 50 and the outer tank container 60 which were described above is demonstrated. First, the manufacturing method of the inner tank container 50 will be outlined below. First, as shown in FIG. 7, a frame 57 made of, for example, FRP having a cylindrical shape is prepared. The frame body 57 is formed as a framework constituting the inner tank container 50. A plurality of superconducting coils 10 are arranged on the outer periphery of the frame body 57 so that the longitudinal direction thereof is along the longitudinal direction of the frame body 57 as shown in FIG.

  For example, an inner tank container outer casing 51 or an inner tank container inner casing 52 made of FRP is attached so as to cover the cylindrical member of the frame 57 of FIG. Further, the end side surfaces 55 and 56 and the side surface of the opening that closes the side surfaces of the opening 53 formed by overlapping the openings of the cylindrical portions of the inner tank container outer case 51 and the inner tank container inner case 52. 54 is arranged. As described above, the inner tank container 50 is provided by arranging and fixing the inner tank container outer casing 51, the inner tank container inner casing 52, the opening side surface 54, and the end casings 55 and 56 around the frame body 57. Is formed.

  The end case 55 constituting the inner tank container 50, or the inner tank container outer case 51 or the inner tank container inner case 52, and one end of the refrigerant supply pipe 1 are connected. As described above, the refrigerant supply pipe 1 includes the inner tank connecting portion 2 and the refrigerant introducing portion 3, but the inner tank connecting portion 2 is connected to the constituent members of the inner tank container 50 such as the end housing 55. It is preferable.

  As shown in the enlarged view of FIG. 8, the refrigerant supply pipe 1 (inner tank connection portion 2) is arranged so as to pass through the end housing 55. Depending on the configuration, a partial region in the longitudinal direction of the inner tank connecting portion 2 of the refrigerant supply pipe 1 reaches the inside of the inner tank container outer casing 51 or the inner tank container inner casing 52 of the inner tank container 50. May be arranged as follows. These connections include, for example, an internal thread formed inside the inner tank container outer casing 51, inner tank container inner casing 52, and end casing 55, and an external thread formed near the end of the inner tank connection section 2. It is preferable that this is done by fitting.

  Moreover, it is preferable to adhere | attach the inner tank connection part 2 and the refrigerant | coolant introducing | transducing part 3 by brazing in the connection part 2a, for example using a silver solder.

It is preferable that the heat resistance movable part 4 formed in the refrigerant introduction part 3 has, for example, a bellows structure. As shown in the cross-sectional view of FIG. 9, the refrigerant introduction portion 3 has a thickness t ₁ of the heat resistance movable portion 4 which is related to the thickness intersecting the extending direction of the structure portion constituting the refrigerant introduction portion 3. It is preferable that the thickness is smaller than the thickness t _{2 of} the region extending linearly other than the region.

  The left side in FIG. 9 is the outside of the inner tank container 50 and the like, and the right side in FIG. 9 is the side connected to the inner tank container 50. Accordingly, in use, the left side of FIG. 9 is a region at or near room temperature, and the right side of FIG. 9 is a region cooled to a very low temperature. That is, in use, heat propagates from the left side to the right side in FIG.

The thermal resistance movable part 4 includes a plurality of bent parts as described above. For this reason, when heat propagates from the left side to the right side in the structure of the refrigerant introduction part 3 (the cylindrical part hatched in FIG. 9), the length of the heat transfer path in the heat resistance movable part 4 is the other part. It will be longer. For this reason, thermal resistance becomes larger in the thermal resistance movable part 4 than in the area other than the thermal resistance movable part 4. Furthermore, if the thickness t ₁ is made thinner than the thickness t ₂ , the cross-sectional area of the wall portion of the heat resistance movable portion 4 in the cross section that intersects the direction in which heat propagates, in which the structure of the refrigerant introduction portion 3 extends, It becomes smaller than the cross-sectional area of the wall portion in the region other than the heat resistance movable portion 4. Therefore, the thermal resistance of the thermal resistance movable part 4 is larger than that of the region other than the thermal resistance movable part 4. That is, in addition to the bellows structure including the bent portion, if the cross-sectional area of the structure region (wall portion) in the bellows structure is reduced, this also increases the thermal resistance in the bellows structure, and the heat is shown in FIG. Propagation from the left side to the right side can be suppressed. That is, it is possible to suppress the occurrence of problems such as the temperature of the inside of the inner tank container 50 becoming high or the refrigerant 17 inside the inner tank container 50 evaporating due to heat transmitted through the refrigerant supply pipe 1.

In order to further enhance the effect of increasing the thermal resistance in the thermal resistance movable portion 4 described above, it is preferable to design the thickness t ₁ to be 10% or less of the thickness t ₂ .

  Next, the manufacturing method of the outer tank container 60 will be outlined below. First, each member (the outer tank container outer casing 61 and the outer tank container inner casing 62) constituting the outer tank container 60 is arranged so as to cover the cylindrical area of the inner tank container 50. The outer tub container outer casing 61 is preferably arranged to face each other with a certain distance from the inner tub container outer casing 51. Similarly, it is preferable that the outer tub container inner housing 62 is disposed so as to face each other with a certain distance from the inner tub container inner housing 52.

  However, the outer tank container outer casing 61 and the outer tank container inner casing 62 have a length constituting the cylindrical longitudinal direction of the outer tank container 60, and the inner tank container outer casing 51 and the inner tank container inner casing. It is preferable that the length is longer than 52. This is because the outer tank container 60 is preferably arranged so as to cover the entire inner tank container 50 including the end housings 55 and 56.

  Similarly to the opening side surface 54 that closes the side surface of the opening 53 of the inner tank container 50, the opening side surface 64 that connects the side surfaces of the opening 63 of the outer tank container outer casing 61 and the outer tank container inner casing 62 is provided. Form. And as shown in FIG. 10, the edge part housing | casing 65 and 66 arrange | positioned at the edge part of a longitudinal direction is attached. As described above, the outer tub container outer casing 61, the outer tub container inner casing 62, the opening side surface 64, and the end casings 65 and 66 are arranged, and these are bonded and assembled to form the outer tub container 60. The

  The outer tank container 60 is formed so as to surround the outer periphery of the inner tank container 50. For this reason, as shown in FIG. 10, the end housing 65 constituting the outer tank container 60 is for penetrating through the refrigerant supply pipe 1 of the inner tank container 50 on the ring-shaped surface which is the main surface thereof. It is preferable that a hole 67 is formed. That is, since the outer tank container 60 is provided with the through holes 67, the refrigerant supply pipe 1 penetrates not only the inner tank container 50 but also the members of the outer tank container 60, so that the outside of the outer tank container 60 (that is, room temperature). Can extend to the outside of each container).

  When members such as the outer tub container outer casing 61 constituting the outer tub container 60 are assembled, the outer tube main body 7 is attached as shown in FIG. The outer tube main body 7 is a member that forms the center of the outer tube 6. Referring to the enlarged views of FIG. 11 and FIG. 12, one of the end casing 65 constituting the outer tub container 60, or the outer tub container outer casing 61 or the outer tub container inner casing 62, and the outer tube main body 7. Connect the end of the.

  As shown in the enlarged view of FIG. 12, the outer tub connecting portion 5 is disposed at one end of the outer tube main body 7 in the longitudinal direction. For example, when the outer tub container 60 is made of FRP, it is preferable to use a material made of an alloy in which nickel and cobalt are blended in iron as the material of the outer tub connection portion 5. In addition, when the material which comprises the outer tank container 60 changes, the material of the outer tank connection part 5 can be adjusted by adjusting the content rate of nickel. This is because the thermal expansion coefficient of the alloy can be adjusted by adjusting the nickel content.

  And it is preferable that the outer tub connection part 5 and the outer pipe | tube main body 7 are adhere | attached by brazing in the connection part 5a, for example using a silver solder. In this way, the outer tube main body 7 is arranged such that the outer tub connecting portion 5 is fitted and inserted into the end casing 65 (or the outer tub container outer casing 61 or the outer tub container inner casing 62). As a result, the outer tank container 60 is connected. These connections include, for example, an external thread formed inside the outer tub container outer casing 61, outer tub container inner casing 62, and end casing 65, and an external thread formed near the end of the outer tub connection section 5. It is preferable that this is done by fitting.

  As shown in FIGS. 11 and 12, the outer tube main body 7 preferably has a heat resistance movable portion 8 similar to the heat resistance movable portion 4 of the refrigerant introduction portion 3 of the refrigerant supply tube 1. In order to form the heat resistance movable portion 8, the outer tube main body 7 is preferably made of a stainless material such as SUS316 or SUS304, as in the refrigerant introduction portion 3. If it does in this way, while the process of the bending part of the heat resistance movable part 8 of the outer pipe | tube main body 7 will become easy, the connection with the outer tank connection part 5 which consists of an iron, nickel, and cobalt alloy mentioned above will become easy. . In addition, when the material which comprises the outer tank connection part 5 changes, the material of the outer pipe | tube main body 7 can be adjusted by adjusting the content rate of nickel. This is because the thermal expansion coefficient of the alloy can be adjusted by adjusting the nickel content.

  As shown in FIG. 13, the outer tube main body 7 has an outer side of the heat resistance movable portion 8 (as viewed from the outer tank container 60) and a direction in which the outer tube main body 7 extends from the heat resistance movable portion 8. It has a flange with a large diameter in the cross section. However, it is preferable that such a configuration is arbitrarily formed according to the application. For example, the outer tube main body 7 may not include the flange.

  Further, as shown in FIG. 13, the external connection flange 9 is connected to the outer side of the outer tube main body 7 (as viewed from the outer tank container 60). As an example, in FIG. 13, the external connection flange 9 is connected to the outside of the outer tube main body 7 (on the side opposite to the outer tank container 60 with respect to the extending direction) by welding. The external connection flange 9 is preferably formed of, for example, SUS304, but may be formed of SUS316. The outer pipe 6 is formed by the external connection flange 9, the outer pipe main body 7, and the outer tub connection portion 5 described above. The external connection flange 9 is preferably provided with a vacuum port, for example. The vacuum port is provided to keep a gap between the outer tube 6 and the refrigerant supply tube 1 described later in a vacuum state. If it does in this way, it can control that heat propagates to refrigerant supply pipe 1 from the exterior, for example. The vacuum port is preferably formed of, for example, SUS316, but may be formed of SUS304.

  As described above, the outer tank container 60 to which the outer tube 6 is attached is formed as shown in FIG. The inner tank container 50 is arranged inside the outer tank container 60 of FIG. The aspect is shown in the cross-sectional view of FIG. However, although the outer tube 6 is shown in FIG. 6, it is not shown in FIG. That is, only the refrigerant supply pipe 1 is shown in FIG. 14 as the refrigerant pipe.

  FIG. 15 is a schematic diagram of the main part of the cross-sectional view of FIG. However, FIG. 15 is a schematic diagram, and details of FIG. 14 are not necessarily reflected faithfully. For example, in FIG. 14, the outer tube main body 7 is provided with a flange having a cross-sectional diameter larger than that of the tube portion, but is omitted in FIG. Further, with respect to other portions, there is a slight difference between FIG. 14 and FIG. This is because the schematic diagram of FIG. 15 is easy to see. Further, in FIG. 15, the outer tube 6 omitted in FIG. 14 is shown.

  As shown in FIG. 15, for example, the inner tank container 50 and the inner tank connecting portion 2 of the refrigerant supply pipe 1 are connected by a screw portion 101. Similarly, the outer tub container 60 and the outer tub connecting portion 5 of the outer pipe 6 are connected by a screw portion 102. As described above, since the difference in coefficient of thermal expansion between the superconducting coil container (inner tank container 50 and outer tank container 60) and the pipe connection parts (connection parts 2a, 5a) is reduced, the screw parts 101, 102 are used. It is possible to suppress the occurrence of a large thermal stress due to the difference in thermal shrinkage.

  Further, there is a gap at a constant interval between the inner tank container 50 and the outer tank container 60. This is the gap 21 shown in FIG. 2 described above, and suppresses the heat of the outside air from propagating from the outer tank container 60 to the inside of the inner tank container 50. Similarly, a gap 22 exists between the refrigerant supply pipe 1 and the outer pipe 6 (particularly between the refrigerant introduction part 3 and the external connection flange 9) in the pipe through which the refrigerant flows. The gap 22 also suppresses the heat of the outside air from propagating from the outer pipe 6 (external connection flange 9) to the inside of the refrigerant supply pipe 1 (refrigerant introduction part 3).

  The thermal resistance movable part 4 and the thermal resistance movable part 8 shown in FIG. 15 have a bellows structure as described above. However, the heat resistance movable portion may include a bent portion, and any mode having a function of increasing the heat resistance as compared with a region where the bent portion extends linearly may be used. For example, as shown in FIG. 16, a structure in which a wave-like bent portion 14 as a bent portion extends from the pipe 19 may be used. The piping 19 here corresponds to, for example, the refrigerant introduction part 3 and the outer pipe main body 7 in FIG. 14 (FIG. 15), and the wavy bent part 14 here is, for example, the heat resistance movable part 4 in FIG. 14 (FIG. 15). , 8.

  FIG. 16 shows a mode in which the wave-like bent portion 14 is cut (from the same direction) as the heat resistance movable portions 4 and 8 (bellows structure) of FIG. As shown in FIG. 16, in the wavy region of the wavy bent portion 14, the cross-sectional area intersecting with the extending direction of the pipe 19 (the left-right direction in FIG. 16) may be increased. Alternatively, as shown in FIG. 17, even in the wavy region of the wavy bent portion 14, the cross-sectional area is substantially the same as the region in which the pipe 19 extends in a straight line (the pipe 19 extends and intersects in the left-right direction in FIG. 17. The aspect which becomes the area of a cross section) may be sufficient.

  As a result of the formation of the bent portion in the wave-like bent portion 14 as compared with the linearly extending region of the pipe 19, the thermal resistance is increased. For this reason, by providing the pipe 19 with the wave-like bent portion 14, it is possible to suppress the heat of the outside air from being transmitted to the inside of the inner tank container 50 through the pipe 19. That is, by providing the wave-like bent portion 14, the distance that heat propagates along the structure constituting the pipe 19 (in the left-right direction in FIGS. 16 and 17) becomes longer. For this reason, it can suppress that the heat of external air is propagated through the piping 19 and the inside of the inner tank container 50.

  Note that, similarly to the above-described bellows structure, the thickness of the structure in the wavy bent portion 14 is thinner than the thickness of the structure in the region other than the wavy bent portion 14 (extending linearly) in the pipe 19. preferable. When heat propagates from the left side to the right side of the structure of the pipe 19 (the cylindrical part hatched in FIGS. 16 and 17), the thickness of the structure in the wavy bent portion 14 is set to the If the thickness is smaller than the thickness, the cross-sectional area of the cross section that intersects the direction in which heat propagates is smaller in the wavy bent portion 14 than in the region other than the wavy bent portion 14. Therefore, the wavy bent portion 14 has a higher thermal resistance than the region other than the wavy bent portion 14. In other words, if the cross-sectional area of the structure region of the wave-like bent portion 14 is reduced, this also increases the thermal resistance in the wave-like bent portion 14 and suppresses heat from being propagated from the left side to the right side in FIGS. can do. That is, it is possible to suppress a phenomenon that the temperature of the inside of the inner tank container 50 becomes high due to heat transmitted through the refrigerant supply pipe 1.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  The present invention suppresses heat intrusion into the inside of a container on which a superconducting coil is placed, and suppresses damage to the container due to thermal stress between the container and a pipe that supplies a refrigerant to the inside of the container. Therefore, it is particularly excellent as a technique for providing a high-quality superconducting coil.

  DESCRIPTION OF SYMBOLS 1 Refrigerant supply pipe, 2 Inner tank connection part, 2a, 5a connection part, 3 Refrigerant introduction part, 4,8 Thermal resistance movable part, 5 Outer tank connection part, 6 Outer pipe, 7 Outer pipe body, 9 Outer connection flange, DESCRIPTION OF SYMBOLS 10 Superconducting coil, 13 Rotor core, 14 Wave-like bending part, 16 Rotor shaft, 17 Refrigerant, 18 Output shaft, 19 Piping, 20 Stator, 21, 22 Gap, 23 Stator core, 30 Rotor, 35 Bearing, 50 Inner tank container, 51 Tank container outer casing, 52 Inner tank container inner casing, 53, 63 Opening, 54, 64 Opening side, 55, 56, 65, 66 End casing, 57 Frame, 60 Outer tank container, 61 Outside Tank container outer casing, 62 outer tank container inner casing, 67 penetration hole, 100 superconducting motor, 101, 102 threaded portion.

Claims (5)

An inner tank,
An outer tub that holds the inner tub inside;
Reaching from the outside of the outer tank to the inside of the inner tank, and a refrigerant supply pipe connected to the inner tank,
An outer pipe that surrounds the refrigerant supply pipe outside the outer tank and is connected to the outer tank;
The refrigerant supply pipe is
An inner tank connection,
A heat resistance movable part,
The first thermal expansion coefficient of the material constituting the inner tub connection portion is 50% or more and 200% or less of the second thermal expansion coefficient of the material constituting the inner tub,
The thermal resistance movable part has a larger thermal resistance than the region other than the thermal resistance movable part in the refrigerant supply pipe,
And the container for superconducting coils in which the said heat resistance movable part contains a bending part.   The superconducting coil container according to claim 1, wherein the heat resistance movable part has a bellows structure.   The superconducting coil container according to claim 2, wherein a thickness of the refrigerant supply pipe in the bellows structure is thinner than a thickness of a region other than the bellows structure of the refrigerant supply pipe. The inner tub connections iron, nickel, and a material containing at least one selected from cobalt, superconducting coil container according to any one of claims 1 to 3. A container for a superconducting coil according to claim 1;
A superconducting device comprising a superconducting coil disposed inside the superconducting coil container.

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