JPS62213565A - Rotor of superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To smoothly remove the heat of a superconducting field coil by forming a groove on the surface of a wedge at the side of the coil. CONSTITUTION:The rotor of a superconductive rotary electric machine is composed of a coil mounting shaft 2 having a helium flowing hole 21, a superconducting field coil 3, a helium outer cylinder 6, a liquid helium reservoir 15, and a filler 19. In this case, a wedge 22 for fixing the coil 3 is provided, a groove 23 is formed on the surface of the wedge 22 at the coil 3 side to communicate with a gap between the hole 19a of the filler 19 and the wedge 22. Thus, the heat of the coil 3 is absorbed by helium, and fed through the hole 21 to the reservoir 15. The helium cooled by the reservoir 15 is fed from other flowing hole 21 through the periphery of the coil 3, a through hole 19a, the groove 23 of the wedge 22 and the gap to a helium passage 20. As a result, the flowing resistance of the cooling circuit of the coil 3 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a rotor of a superconducting rotating electric machine.

[Conventional technology]

Conventionally, as a rotor of this type, for example, Japanese Patent Application Laid-Open No. 57-2287
No. 2 (ζ) is disclosed, and its configuration is shown in Figure 8. In Figure 8, 11) is a torque tube,
(2) is the coil mounting shaft that forms the center of the torque tube U), (3) is the superconducting field coil fixed to the coil mounting shaft (2), and (4) is the torque tube (1) and coil mounting A room-temperature damper surrounding the shaft (2), (5) a low-temperature damper disposed between the room-temperature damper (4) and the coil mounting shaft (2), and (6) and (7) the coil mounting shaft (
Helium outer cylinder and helium end plate attached to the outer periphery and side surface of 2), (8) and (9) are drive side and non-drive side end shafts, respectively, uq is these end shafts + 8), +9
), aη is a slip ring for supplying field current, curve is the heat exchanger formed or placed on the torque tube (1), (to) is the side radiation shield, (J4 is the vacuum part It is.

In the rotor of the superconducting rotating machine having the above configuration, the electrical resistance is brought to zero by cooling the superconducting field coil (3) disposed on one coil mounting shaft (2) to an extremely low temperature. By eliminating excitation 81 loss, a strong magnetic field is generated in this superconducting field coil (3), and AC power is generated in the stator (not shown).This superconducting field coil (3) is heated to an extremely low temperature. In order to cool and maintain liquid helium, the liquid helium is introduced from the center of the non-drive side end shaft (9) through an introduction pipe (not shown), and the liquid helium formed by the helium outer cylinder (6) and the helium end plate (7) is introduced. While supplying to the container section, the inside of the rotor is maintained at a high vacuum by the vacuum section 414),
Cryogenic superconducting field coil (3) and coil mounting shaft (2)
The most common structure is to use a thin-walled cylindrical torque tube (1) that transmits rotational torque to the torque tube (υ) and a heat exchanger (2) to reduce as much as possible the heat that enters the cryogenic region through the torque tube (υ). Furthermore, side radiation shields 4 are provided to reduce heat entering from the sides.

On the other hand, the normal temperature damper (4) and the low temperature damper (5) shield the harmonic magnetic field from the stator, and the superconducting field coil (
3) and has the function of damping rotor vibrations caused by disturbances in the power system.
) generally functions as a vacuum outer cylinder, and the low-temperature damper also functions as a radiation shield for the helium container. In FIG. 8, the piping constituting the helium introduction and discharge system inside the rotor and the helium introduction and discharge device connected to the rotor are omitted.

FIG. 9 is a cross-sectional view taken along the -1 X line of FIG.

This is disclosed in Japanese Unexamined Patent Publication No. 57-202852.

(2) is the coil mounting shaft, (3) is the superconducting field coil, (
6) is a helium cylinder, a! 9 is the liquid helium reservoir, C1l is the helium vapor space, αη is the coil mounting shaft (
A slot for housing the superconducting field coil (3) formed in 2).

(Foundation) is a wedge that fixes the superconducting field coil (3),
Ql is a plug inserted between the superconducting field coil (3) and the wedge (g), and has, for example, a circular through hole (19a). ■ is a helium flow path provided between the coil mounting shaft (2) and the helium outer cylinder (6), ■
η is a coil mounting shaft helium flow hole provided in communication with the liquid gap QFj and the bottom of the slot αη. still.

Although not shown, the superconducting field coil (3) and the slot α force surface are insulated so that helium flow cannot be prevented.

Generally speaking, in superconducting rotating electric machines, there is an important technical problem in how to cool the superconducting field coil to a cryogenic temperature. In order to bring a superconducting field coil into a superconducting state, it is necessary to cool it below the superconducting transition temperature.
It is practiced to maintain the temperature between 20Kfζ and 20Kfζ. On the other hand, in such extremely low temperature conditions, the specific heat of the superconducting field coil is extremely small, so the superconducting field coil may be damaged due to minute heat generation within the superconducting field coil or a small amount of heat entering the superconducting field coil. There is always a risk that the temperature will rise and exceed the superconducting transition temperature. Therefore, in the design of superconducting rotating electric machines, it is important to suppress the temperature rise of the superconducting field coils by quickly removing the minute amount of heat generated within the superconducting field coils or the slight amount of heat entering the superconducting field coils. This is an important point.

Next, the cooling operation will be explained based on FIG.

The heat generated by slight heat generation within the superconducting field coil (3) or by slight heat intrusion into the superconducting field coil (3) exists in a quiet gap around the superconducting field coil (3). Absorbed by helium. Helium, which expands due to heat absorption and has a reduced density, exits the liquid reservoir Q5iζ through the helium flow hole η of the coil mounting shaft (2) due to the natural convection of the centrifugal force field. On the other hand, the helium shortage that occurs around the superconducting field coil (3) is caused by the helium channel 4 being connected to the wedge (
This is supplemented by helium flowing around the superconducting field coil (3) through the gap in g) and the through hole (19a) of the pawl 09. The endothermically expanded helium flows into the liquid dragon part (7
), a portion of it evaporates (1) and is thereby cooled. The cooled helium enters around the superconducting field coil (3) from another coil mounting shaft helium flow hole G11l, and further passes through the gap between the through hole (19a) and the wedge (g) of the pawl, and the helium is reduced. By performing the smooth natural circulation as described above, the superconducting field coil (3) is cooled, and the O that exits the path (7) is kept below the superconducting transition temperature. [Problems to be solved by the invention] Conventionally, the structure is as described above, and the helium passages in the wedge α and the claw parts are narrower than other parts, as shown in FIG. The flow of helium was restricted at this location.

Some of the through holes (19a) in the opening of the clamp α open into the gap between the wedges α, and the helium that exits through the through hole α that is not open is between the wedge (g) and the clamp. It will flow through the slight gap between it and Ql.

In the conventional configuration, there was a major problem in that the superconducting field coil (3) was poorly cooled, and as a result, there was a high possibility that normal conduction transition would occur and the generator would stop functioning.

This invention was made to solve the above-mentioned problems.
The objective is to obtain a rotor for a superconducting rotating electric machine that does not cause normal conduction transition.

[Means for solving problems]

The rotor of the superconducting rotating electric machine according to the present invention has grooves provided on the surface of the wedge on the FA conductive field coil side.

[Effect]

The rotor of the superconducting rotating electrical machine in this invention is:

The groove provided on one surface of the wedge on the superconducting field coil side improves the flow of helium, allowing smooth heat removal from the superconducting field coil, and improving the performance of the superconducting field coil.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In Figures to Figure 4, t2), (3), ((
1), 05~0η, and σ1~12υ are similar to the configuration of the conventional rotor described above. (2) is the wedge that fixes the superconducting field coil (3), and (2) is this wedge (A).
It is a groove provided on the surface of the superconducting field coil (3) side, and communicates with the gap between the through hole α0 of the pawl 09 and the wedge).

The figure is provided in the axial direction and the width direction as an example. Note that the through hole (19a) of the pawl (6) is shown not only at the center in the width direction but also at a position opposite to the groove in one width direction. Next, the operation will be explained. Heat generated by slight heat generation within the superconducting field coil (3) or by slight heat intrusion into the superconducting field coil (3) exists in a small gap around the superconducting field coil (3). Helium is absorbed. The helium, which expands due to heat absorption and has a reduced density, exits to the liquid reservoir (c) through the coil mounting shaft helium flow hole C2] due to the natural convection of the centrifugal force field. On the other hand, the helium shortage that occurs around the superconducting field coil (3) is caused by the helium flow path (7), the gap between the wedges (a), the wedge slope groove (2), and the through hole (19a) of the clasp. This is supplemented by helium flowing around the superconducting field coil (3) through the The endothermically expanded helium is collected in the liquid reservoir (G), and the helium, which has been cooled by evaporation, is transferred from the helium hole η of another coil mounting shaft to the superconducting field coil (3). A through-hole (19a) that goes into the surrounding area and is even more closed.
It passes through the gap between the wedge (a) and the wedge) and exits to the helium flow path (7). In this way, helium flows through the groove 4 of the wedge (a), so
The flow path resistance of the cooling circuit of the superconducting field coil (3) is reduced.

As the helium flow rate increases, the through hole of the closure Ql (
There is no imbalance in the flow rate of helium passing through the coil 19a), allowing smooth natural circulation of helium and efficient cooling of the superconducting field coil (3).

The superconducting field coil (3) is kept below the superconducting transition temperature. In other words, the high-temperature helium that absorbed heat from the superconducting field coil (3) no longer stays around the superconducting field coil (3), and the function of the generator 1 is stopped without normal conduction transition occurring. There's nothing to do.

In addition, in the above embodiment, the case where the groove (4) provided in the wedge (2) was provided in the axial direction and the width direction was described, but the fifth embodiment
As shown in Figures to Figure 7, grooves (2) may be provided in the wedge only in the width direction of (2). In this case, helium flows in the width direction through the grooves (A) as shown in Figure 7, and the helium flows along the wedge slope. and the coil mounting shaft (2), flows in the longitudinal direction of the wedge, and reaches the gap between the wedge stones. Also, wedge (2
) may be provided only in the axial direction, and the same effect as in the above embodiment can be achieved.

〔Effect of the invention〕

As explained above, this invention is achieved by forming grooves on the surface of the wedge on the side of the superconducting field coil.

The flowability of helium is improved, heat can be removed smoothly from the superconducting field coil, the performance of the superconducting field coil can be improved, and a highly reliable rotor of a superconducting rotating electric machine can be obtained.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 2 are a plan view and a front view showing a wedge in a rotor of a superconducting rotating electric machine according to an embodiment of the present invention,
FIG. 8 is a cross-sectional view showing the slot portion according to the present invention;
The figure is a sectional view showing the flow of helium related to this invention,
5 and 6 are a plan view and a front view showing a wedge in a rotor of a superconducting rotating electric machine according to another embodiment of the present invention, and FIG. 7 is a cross section showing a slot portion according to another embodiment of the present invention. 8 is a sectional view showing the overall concept of a rotor of a general superconducting rotating electric machine, FIG. 9 is a sectional view taken along line IX-[ in FIG. 8, and FIG. 10 is a rotor of a conventional superconducting rotating electric machine. FIG. 3 is a cross-sectional view showing the flow of helium in FIG. In the figure, (2) is a coil mounting shaft, (3) is a superconducting field coil, Qη is a slot, @ is a wedge, and IR is a groove. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A coil mounting shaft with multiple axial slots formed on the shaft surface, a superconducting field coil housed in the slot formed in this coil mounting shaft, and a wedge for fixing this superconducting field coil. A rotor for a superconducting rotating electrical machine, characterized in that grooves are formed on the surface of the wedge on the side of the superconducting field coil. (2) A rotor for a superconducting rotating electric machine according to claim 1, wherein the grooves are formed in the axial direction and the width direction. (3) A rotor for a superconducting rotating electrical machine according to claim 1, wherein the grooves are formed in the width direction. (4) A rotor for a superconducting rotating electric machine according to claim 1, wherein the grooves are formed in the axial direction.