JPH11235009A - Current lead of rotor of superconducting rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a contact failure between constituting members with good cooling capability of a current lead. SOLUTION: In a current lead which supplies current from a room temperature part to a low temperature part of the rotor of a superconducting rotating machine, a multiple-layer pipe is constituted of an inner pipe 7 with fins of a conductive metal having fins 7a extending at the inside circumference side in the axial direction and protruding in the radial direction and an outer pipe 8 with fins of a conductive metal which forms coolant flowing channels in the axial direction between the outside circumferential surface of the inner pipe 7 with fins and each fin. Furthermore, passing holes 9 are each provided in the pipe wall between the fins 7a of the inner pipe 7 with fins in the axial direction with an appropriate space, so that the coolant flowing channels can be communicated with each other in the radial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current lead for a rotor of a superconducting rotary electric machine for supplying a current from a normal temperature portion to a low temperature portion.

[0002]

2. Description of the Related Art Conventionally, when a large current is supplied from a normal temperature portion to a low temperature portion, particularly a liquid helium temperature region, like a current lead of a rotor of a superconducting rotary electric machine, conduction heat from the normal temperature portion and Joule heat due to current are generated. In order to prevent intrusion into the low-temperature portion, cooling is performed using a vaporized gas of current lead helium or the like.

[0003] In this early type, the outer periphery of a cylindrical current lead was simply cooled with helium evaporating gas. However, since the cooling performance was not so good, a heat exchanger was provided inside the current lead. Are used.

FIG. 12 is a cross sectional view showing an example of a current lead of a rotor of a conventional superconducting rotary electric machine, and FIG. 13 is a longitudinal sectional view of the current lead. As shown in FIGS. 12 and 13, a large number of pipes 1 made of a conductive metal are inserted into an outer cylinder 2 made of a conductive metal, and a gap with the pipe 1 in the outer cylinder 2 is filled with a conductive filling member 3. The structure is such that the inside of the pipe is densely filled and the refrigerant channel 4 is used. A normal temperature terminal 5 and a low temperature terminal 6 are connected to both ends of the current lead.

[0005] In the current lead of the rotor of the superconducting rotary electric machine having such a configuration, current flows through the pipe 1, the outer cylinder 2, and the filling member 3 from the normal temperature side to the low temperature side, and the gas refrigerant flows through the inside of the pipe at the low temperature. Flows from the side to the room temperature side. In this case, the viscosity of the gas refrigerant flowing in the pipe, particularly gas helium, depends on the temperature. The lower the temperature, the easier it is to flow in the pipe, and the higher the temperature, the harder it is to flow in the pipe.

[0006] For this reason, in the current lead having such a structure, if there is a temperature distribution in the cross section, a pipe in which the gas refrigerant easily flows and a pipe in which the gas refrigerant hardly flows occur, and the gas refrigerant flows only in a low temperature portion on the cross section. Because it will flow unevenly,
There was a problem that the cooling efficiency was reduced. In addition, since the adhesion between the filling member 3 and the outer cylinder 2 and the adhesion between the filling member 3 and the pipe 1 are not good, the electric resistance at the contact portion increases, and the current does not flow uniformly on the same cross section, and the Joule is partially formed. There is also a problem that heat generation becomes large, and a problem that heat conduction is poor due to poor contact and cooling performance is reduced.

[0007]

As described above, the current lead of the rotor of the conventional superconducting rotary electric machine has a reduced cooling performance due to the drift of the gaseous refrigerant and an electric resistance due to poor contact between the members. The structure was liable to cause loss and poor heat conduction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a current lead for a rotor of a superconducting rotary electric machine which has good cooling performance and can prevent poor contact between constituent members. It is in.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a current lead for a rotor of a superconducting rotary electric machine by the following means. Claim 1
The present invention relates to a current lead of a rotor of a superconducting rotating electrical machine that supplies current from a normal temperature portion to a low temperature portion, wherein the conductive metal has a plurality of fins extending in an axial direction on an inner circumferential side and protruding in a radial direction. And a multi-tube integrated with an external finned tube made of a conductive metal having an axial refrigerant passage between the outer peripheral surface of the internal finned tube and each fin. A plurality of through holes are provided in the tube wall between the fins of the inner finned tube at appropriate intervals in the axial direction so that the refrigerant flow paths communicate with each other in the radial direction.

[0010] In the invention corresponding to claim 1 above,
By allowing the refrigerant flow paths to communicate in the radial direction, drift of the gas refrigerant can be prevented, and cooling performance can be improved. According to a second aspect of the present invention, there is provided a current lead of a rotor of a superconducting rotary electric machine according to the first aspect of the present invention, wherein a through hole formed in a pipe wall of a pipe disposed inside is formed by a ring-shaped groove. It is.

According to a third aspect of the present invention, there is provided a current lead for a rotor of a superconducting rotary electric machine according to the first aspect of the present invention, wherein a through hole formed in a pipe wall of a pipe disposed inside has a spiral shape in an axial direction. Formed by the groove of FIG.

In the invention corresponding to the second and third aspects, by forming a plurality of grooves in the pipe wall disposed inside, the communication cross-sectional area of the refrigerant flow path can be increased, and Since the refrigerant flow path is also communicated in the direction, the effect of preventing the gas refrigerant from drifting is improved, and as a result, the cooling performance can be improved.

According to a fourth aspect of the present invention, there is provided a current lead of a rotor of a superconducting rotary electric machine for supplying current from a normal temperature portion to a low temperature portion, wherein the spiral lead extends axially inwardly and protrudes radially. Inner finned tube made of a conductive metal having fins, and an external conductive metal made of a conductive metal having an axial refrigerant flow path between the outer peripheral surface of the inner finned tube 7 and the spiral fins. The finned tube and the finned tube are integrated into a multi-tube, and a plurality of through-holes are provided in the tube walls between the fins of the inner finned tube to connect the refrigerant flow paths in the radial direction.

[0014] In the invention corresponding to claim 4 above,
By making the fins spiral in the axial direction, the wetted area of the refrigerant increases, so that the heat exchange rate of the gas refrigerant increases and the cooling performance can be improved.

According to a fifth aspect of the present invention, in the current lead of the rotor of a superconducting rotary electric machine according to the first or fourth aspect of the present invention, a column-shaped filling is inserted into the innermost finned tube. It was done.

In the invention corresponding to the fifth aspect,
By inserting the cylindrical filler into the innermost finned tube, it is possible to prevent the gaseous refrigerant from passing unbalancedly to the innermost portion having a low tube frictional resistance, and to improve the cooling performance.

According to a sixth aspect of the present invention, there is provided a current lead for a rotor of a superconducting rotary electric machine according to the first or fourth aspect, wherein the inner finned tube and the outer finned tube are combined and drawn. To form a multiple tube.

According to a seventh aspect of the present invention, in the current lead of the rotor of the superconducting rotary electric machine according to the first or fourth aspect, the inner finned tube and the outer finned tube are joined by diffusion bonding. To form a multiple tube.

In the inventions corresponding to the sixth and seventh aspects, the electric resistance generated on the contact surface can be reduced by improving the adhesion between the tubes, and the heat conduction is also improved. The cooling performance can be improved.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a first embodiment of the present invention,
FIG. 2 is a longitudinal sectional view of the same.

In the first embodiment, as shown in FIGS. 1 and 2, an inner portion made of a conductive metal having a plurality of fins 7a extending in the axial direction toward the inner periphery and projecting in the radial direction at regular intervals. And fins 8a which extend in the axial direction to the inner peripheral side and protrude in the radial direction at equal intervals, so that the outer peripheral surface of the inner finned pipe 7 and each fin 8a A multi-tube is formed by integrating an external finned tube 8 made of a conductive metal serving as an axial refrigerant flow path 4, and a plurality of through-holes are formed in a tube wall between the fins 8 a of the internal finned tube 7. Holes 9 are provided to connect the coolant flow paths 4 in the radial direction. In this case, the through holes 9 are provided at appropriate intervals in the axial direction.

Accordingly, with the current lead having such a configuration, the through holes 9 are provided in the pipe walls between the fins 7a of the inner finned pipe 7 so that the refrigerant flow path 4 communicates in the radial direction. In addition, the drift of the gas refrigerant can be prevented, and the cooling performance can be improved.

FIG. 3 is a transverse sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a second embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of the same, which is the same as FIG. 1 and FIG. Will be described with the same reference numerals.

In the second embodiment, as shown in FIGS. 3 and 4, an inner portion made of a conductive metal having a plurality of fins 7a extending in the axial direction toward the inner periphery and projecting in the radial direction at regular intervals. And fins 8a which extend in the axial direction to the inner peripheral side and protrude in the radial direction at equal intervals, so that the outer peripheral surface of the inner finned pipe 7 and each fin 8a A multiplex pipe is formed by integrating an external finned pipe 8 made of a conductive metal as an axial refrigerant flow path 4, and a through-hole communicating with the refrigerant flow path 4 is formed in a pipe wall of the internal finned pipe 7. Ring holes 10 are provided as holes at appropriate intervals in the axial direction.

Accordingly, with the current lead having such a configuration, the communication cross-sectional area of the refrigerant flow path 4 can be increased as compared with the current lead having the through hole as in the first embodiment, and the circumferential direction can be improved. Since the refrigerant flow path 4 is also connected to the refrigerant flow, the effect of preventing the gas refrigerant from drifting is improved, and as a result, the cooling performance can be improved.

FIG. 5 is a transverse sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a third embodiment of the present invention, and FIG. 6 is a longitudinal sectional view of the same, which is the same as FIG. 1 and FIG. Will be described with the same reference numerals.

In the third embodiment, as shown in FIGS. 5 and 6, an inner portion made of a conductive metal having a plurality of fins 7a extending in the axial direction toward the inner periphery and projecting in the radial direction at regular intervals. And fins 8a which extend in the axial direction to the inner peripheral side and protrude in the radial direction at equal intervals, so that the outer peripheral surface of the inner finned pipe 7 and each fin 8a A multiplex pipe is formed by integrating an external finned pipe 8 made of a conductive metal as an axial refrigerant flow path 4, and a through-hole communicating with the refrigerant flow path 4 is formed in a pipe wall of the internal finned pipe 7. A spiral groove 11 is provided as a hole.

Therefore, even with the current lead having such a configuration, the same operation and effect as those of the second embodiment can be obtained. FIG. 7 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a fourth embodiment of the present invention, and FIG. 8 is a vertical cross-sectional view thereof. The description will be made with reference to FIG.

In the fourth embodiment, as shown in FIGS. 7 and 8, an inner finned tube made of a conductive metal and having a spiral fin 7b protruding in the radial direction on the inner peripheral side in the axial direction. 7 and a spiral fin 8b similarly protruding in the radial direction on the inner peripheral side is formed in the axial direction, and the refrigerant flow in the axial direction flows between the outer peripheral surface of the inner finned tube 7 and the spiral fin 8b. A multi-tube is formed by integrating an external finned tube 8 made of a conductive metal as the passage 4, and a plurality of through holes 9 are formed in the tube wall between the spiral fins 8 b of the internal finned tube 7. Each is provided so that the refrigerant flow path 4 communicates in the radial direction.

Therefore, with the current lead having such a structure, the heat exchange rate of the gaseous refrigerant increases because the wet area of the refrigerant is larger than that of the fins extending straight in the axial direction. The cooling performance can be improved.

FIG. 9 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a fifth embodiment of the present invention.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described here.

In the fifth embodiment, as shown in FIG. 9, a plurality of through holes 9 are provided in the pipe wall between the fins 8a of the internal finned pipe 7 to communicate the refrigerant flow path 4 in the radial direction. Then, the column-shaped filling 12 is inserted into the inside of the finned tube 7 inside.

Therefore, with the current lead having such a configuration, in addition to the same operation and effect as in the first embodiment, the column-shaped filler 12 inserted into the inside of the finned tube 7 is formed.
Thereby, it is possible to prevent the gaseous refrigerant from flowing to the inner finned pipe 7 having a small pipe frictional resistance, and to improve the cooling performance.

FIG. 10 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a sixth embodiment of the present invention. The same parts as those in FIG. In the sixth embodiment, as shown in FIG. 10, an inner finned tube 7 made of a conductive metal having a plurality of fins 7a extending in the axial direction inwardly and projecting in the radial direction at equal intervals is provided. Similarly, an outer finned tube 8 made of a conductive metal and having a fin 8a extending in the axial direction on the inner peripheral side and protruding in the radial direction at an equal interval is concentrically arranged. The gap between the finned tube 8 and the external finned tube 8 is integrated to form a multiple tube by drawing or diffusion bonding.

FIG. 11 is a cross-sectional view of a current lead in which the inner finned tube 7 and the outer finned tube 8 are integrated. By performing the matching drawing or the diffusion bonding as described above, the fin portions of the inner finned tube 7 and the outer finned tube 8 are joined, and a state in which both the fin portions are mechanically and electrically integrated. Become. Therefore, by improving the adhesion between the tubes, it is possible to reduce the electric resistance generated on the contact surface, and also to improve the heat conduction, thereby improving the cooling performance.

[0036]

As described above, according to the present invention, the drift of the gaseous refrigerant and the poor contact between the constituent members can be prevented, so that the drift of the current is small and the cooling performance of the superconducting rotary electric machine is high. A current lead can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the embodiment.

FIG. 3 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of the embodiment.

FIG. 5 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of the embodiment.

FIG. 7 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a fourth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of the embodiment.

FIG. 9 is a cross-sectional view of a current lead of a rotor of a superconducting rotary electric machine according to a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view of a current lead according to a sixth embodiment of the present invention when a finned tube is arranged.

FIG. 11 is a cross-sectional view after the finned tube is integrated in the embodiment.

FIG. 12 is a cross-sectional view showing a current lead of a rotor of a conventional superconducting rotary electric machine.

FIG. 13 is a vertical sectional view of the current lead.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pipe 2 ... Outer cylinder 3 ... Conductive filling member 4 ... Cooling channel 5 ... Room temperature side terminal 6 ... Low temperature side terminal 7 ... Internal finned tube 7a ... Fin 7b ... Spiral -Shaped fins 8 ... Tubes with external fins 8a--Fins 8b-Spiral-shaped fins 9--Through holes 10--Grooves 11-Spiral-shaped grooves 12-Column-shaped fillings

Claims (7)

[Claims] 1. A current lead for a rotor of a superconducting rotary electric machine for supplying current from a normal temperature portion to a low temperature portion, comprising a conductive metal having a plurality of fins extending in an axial direction on an inner peripheral side and protruding in a radial direction. And a finned tube made of a conductive metal integrated with an outer circumferential surface of the inner finned tube and each fin as an axial refrigerant flow path. And a plurality of through-holes provided at appropriate intervals in the axial direction in the tube wall between the fins of the inner finned tube to radially communicate the refrigerant flow paths, wherein Current lead for the rotor of a rotating electric machine. 2. The superconducting rotating electric machine according to claim 1, wherein a through hole formed in a tube wall of a tube disposed inside is formed by a ring-shaped groove. Rotor current lead. 3. A current lead for a rotor of a superconducting rotary electric machine according to claim 1, wherein a through hole formed in a tube wall of a tube disposed inside is formed by a spiral groove in an axial direction. Current lead of rotor of superconducting rotating electric machine. 4. A current lead of a rotor of a superconducting rotary electric machine for supplying a current from a normal temperature portion to a low temperature portion, a conductive metal having a spiral fin that extends in an axial direction on an inner peripheral side and protrudes in a radial direction. And an external finned tube made of a conductive metal having an axial refrigerant flow path between the outer peripheral surface of the inner finned tube 7 and the spiral fin. A superconducting rotary electric machine, wherein a plurality of through-holes are respectively provided in the pipe walls between the fins of the inner finned pipe to allow the refrigerant flow paths to communicate in the radial direction. Current lead. 5. A superconducting rotating electric machine according to claim 1, wherein a cylindrical filler is inserted into the innermost finned tube of the rotor of the rotating electric machine. Rotor current lead. 6. The current lead of a rotor of a superconducting rotary electric machine according to claim 1 or 4, wherein the inner finned tube and the outer finned tube are integrated by drawing and integrated to form a multi-tube. A current lead for a rotor of a superconducting rotating electric machine, characterized in that: 7. A multi-tube comprising a current lead of a rotor of a superconducting rotary electric machine according to claim 1 or 4, wherein an inner finned tube and an outer finned tube are integrated by diffusion bonding. A current lead for a rotor of a superconducting rotating electric machine, characterized in that: