JPS62250865A - Rotor of superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To smoothen the flow of helium inside a slot by introducing a first padding with oval holes between a superconducting field coil and a wedge, and by introducing a second padding with through holes between the superconducting field coil and the first padding. CONSTITUTION:A first padding 22 with oval holes 22a in the slot width direction is introduced between a superconducting coil 3 and a wedge 18. Then between the superconducting field coil 3 and the first padding 22 is introduced a second padding with through holes 23a communicating to the oval holes 22a, e.g., with the diameter larger than the width of the oval holes 22a. The shortage of helium around the superconducting field coil 3 is made up for the helium flowing from the helium passage 20 to the superconducting field coil 3 and around through the clearance between wedges 18, the oval holes 22a of the first padding 22 and through holes 23a of the second padding 23.

Description

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

[Conventional technology]

Conventionally, as this type of rotor, for example, JP-A-57-22R
There is something disclosed in the 5th 29r publication, its composition ft
Shown in Figure 1. In Fig. 1, fi+ is a torque tube, [2) i) a coil mounting shaft forming the central part of the torque tube fi+, (31 is a superconducting field coil fixed to the coil mounting shaft (2), +41fl) torque tube +
11 and the normal temperature Danno (, +
51 I/i This room temperature damper (4) and coil mounting shaft +2
), the low temperature damper is placed between (6) and (7)
are a helium outer cylinder, a helium end plate, (8) and (9) attached to the outer periphery and side surface of the coil mounting shaft (2), respectively.
Bearings that support the drive side and non-drive side end shafts, tto+#: t and straw end shafts +81 and +91, respectively, (2)
(2) is a slip ring for supplying field current, (2) is a heat exchanger shaped like a cape or placed on the torque tube +11, (Q)
3t′i side radiation shield, α◆ is a vacuum part.

In the rotor of the superconducting rotating machine having the above configuration, the superconducting field coil (
3) is cooled to an extremely low temperature to bring the electrical resistance to zero and eliminate excitation loss, thereby generating a strong magnetic field in this superconducting field coil +31 and supplying AC power to the stator (not shown). to occur. This superconducting field coil (
In order to cool and maintain the 31 at an extremely low temperature, liquid helium is passed through an inlet pipe (not shown) from the center of the anti-drive side throat shaft (91), formed by a helium outer cylinder (6) and a helium end plate (7). While supplying liquid helium to the liquid helium container section where Let be a thin cylinder,
The most common method is to use a heat exchanger Q2 to reduce as much as possible the heat that enters the cryogenic part through the torque tube fi+. Additionally, side radiation shields are provided to reduce heat entering due to radiation from the sides.

On the other hand, a normal temperature damper (41) and a low temperature damper (51) seal harmonic magnetic fields from the stator, and superconducting field coils (
31 and damps rotor vibrations caused by disturbances in the power system.
A common method is to function as a 1H vacuum outer cylinder and as a radiation shield for the helium container part in the low-temperature bath. In addition, in FIG. 1, the piping constituting the helium introduction and discharge system inside the rotor and the IJ helium introduction and discharge device connected to the rotor are omitted.

Figure 8 is a cross-sectional view taken along the line ■-■ of Figure γ, that is, JP-A No. 5
It is shown in the '7-202852 publication, (2
) is the coil mounting shaft, (3) is the superconducting field coil, (6)
is the helium outer cylinder, α5 is the liquid helium reservoir, qQ
is the helium vapor space, αη is the slot that accommodates the superconducting field coil (31) formed on the coil mounting shaft (2), and q
Q is the wedge that fixes the superconducting field coil (3), α9
is a plug inserted between the superconducting field coil (3) and the wedge αQ, for example, a circular through hole (19a
)have. (1) is a helium flow path provided between the coil mounting shaft (2) and the outer tube (6), 3N
) is a coil mounting shaft helium flow hole provided in communication with the liquid reservoir (to) and the bottom of the slot αη.

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, and currently, helium is used as a cooling medium to maintain the absolute temperature at an absolute temperature of 1 to 20 K. 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 is heated by a small amount of heat generated within the superconducting field coil or by a small amount of heat entering the superconducting field coil. There is always a risk that the temperature of the superconductor will rise and exceed the superconducting transition temperature. Therefore, it is important in the design of superconducting rotating systems how quickly the slight heat generated in the superconducting field coil can be removed and the temperature rise of the superconducting field coil can be suppressed. This is a great point.

Next, the cooling operation will be explained based on FIG. 9. Heat generated by slight heat generation within the superconducting field coil (31) or by slight heat intrusion into the superconducting field coil (3), or due to helium existing in a small gap around the superconducting field coil (31). The helium tank, which expands due to heat absorption and has a lower density, exits through the helium flow hole of the coil mounting shaft (2) to the liquid reservoir (end) 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) flows from the helium flow path (4) to the area around the superconducting field coil (31) through the gap between the wedges (to) and the through hole (19&) of the pawl a9. The helium is supplemented by helium.The helium that has expanded endothermically is
, a portion of it evaporates to cool it down. The cooled helium enters around the superconducting field coil (3) from another coil mounting shaft helium flow hole eυ, and then passes through the through hole (x9m) of the stopper 09 and the gap between the wedge (toward) and the helium flow. Exit to road (7).

By performing the smooth natural circulation as described above, the superconducting field coil (31) is cooled, and the superconducting field coil (3) is kept below the superconducting transition temperature.

[Problem that the invention seeks to solve]

Conventionally, the structure was as described above, and the helium passage at the head of the nail was narrower than other parts, and the flow of helium was restricted at this location. 0 nails
Among the through holes (19 & ) of 9, only a portion opens into the gap between the wedges (to), and the through holes (19 & ) that are not open are
The helium that exits 9 &) will flow through the small gap between Wedge Scream and Tsumemo 09. Through hole (19a
), the superconducting field coil (31 force is not maintained, so considering the strong centrifugal force, the through hole (19M)
) cannot be increased in diameter. In addition, the thickness of the clamp 09 is determined by the insulation creepage distance between the superconducting field coil (31) and the coil mounting shaft (2), and the thickness cannot be reduced. Therefore, in the conventional configuration, the superconducting field coil (31) There was a big problem that the cooling of the generator was getting worse, and as a result, there was a high possibility that a normal conduction transition would occur and the generator would stop functioning. This invention was made to solve the above-mentioned problems. The purpose of the present invention is to obtain a rotor for a superconducting rotating electrical machine that smoothly removes heat from a superconducting field coil and does not cause normal conduction transition.

[Means for solving problems]

The rotor of the superconducting rotating electrical machine according to the present invention
A first pawl having an oval hole extending in the width direction of the slot is inserted between the coil and the wedge, and a hole connected to the oval hole of the first pawl is inserted between the superconducting field coil and the first pawl. A second pawl having a through hole for communication is inserted.

[Effect]

In this invention, the first claw is provided with an oval-shaped hole in the width direction of the slot, and the second claw is provided with a through hole that communicates with the oval-shaped hole of the first claw. Facilitate distribution.

〔Example〕

Hereinafter, an embodiment fr diagram of the present invention will be described. @
In Figures 1 to 5, the foundation is inserted between the superconducting field coil (3) and the wedge (toward), and has a first pawl having an oval-shaped hole (22a) in the width direction of the slot. ,
(to) is inserted between the superconducting field coil 13 + the 7th first clamp (goods), and the oval-shaped hole in one station of the first clamp (
22 & ), and has a through hole (23M) with a diameter larger than the width of the oval hole (22&), for example, the oval hole (22 m), the through hole (23a)
) fl wedge (to) is placed at a position that matches the gap between them.

Next, the operation will be explained. FIG. 5 shows the flow state of helium in the slot αη. 3)
is absorbed by the helium that exists in the small gap around it. Helium expands due to heat absorption and its density decreases,
Due to the natural convection of the centrifugal force field, the liquid exits to the liquid reservoir 09 through the coil mounting shaft helium flow hole 2)). On the other hand, the helium shortage that occurs around the superconducting field coil (31) is caused by the gap between the helium flow path (E) and the wedge 08, the oval hole (22a) of the @1 clamp (C), and the second Tsumemono (
The superconducting field coil (31) passes through the through hole (23a) of
This is supplemented by helium flowing into the surrounding area. The endothermically expanded helium is cooled by evaporating a portion of it in the liquid reservoir. The cooled helium enters around the superconducting field coil (3:) through another coil mounting shaft helium flow hole 3υ, and then passes through the through hole (2351) of the second claw (c) and the first claw. It exits to the helium flow path through the oval hole (22 & ) of the helium (22 & ) and the gap between the wedges (to). In this way, heat is removed quickly at any position of the superconducting field coil (31), and normal conduction transition does not occur, making it possible to prevent the generator from stopping. Even if the gap between them is -t'' more than the specified value, the helium flow path can be ensured without sagging from the oval hole (22a) or the through hole (23a).Furthermore, as shown in FIG. As shown in FIG. ),
The claw (c) in @2 is a member that also serves as electrical insulation, and the insulation creepage distance tI'i is as shown in Figure 6! 4, the total thickness of the second clasp (goods), A, the dimensions of the through hole (23a) of the second clasp, and the oval hole (22a) of the first clasp (a). ) is expressed as the sum of the difference B (A+B).

In addition, as in the above embodiment, when the diameter of the through hole (23 & ) of the second claw (c) is large, the same applies to the first claw) and the second claw (). By configuring the pawl with the two sheets c), the insulation creepage distance iB can be increased without increasing the thickness A, and the dielectric strength is improved.

〔Effect of the invention〕

As explained above, the present invention includes inserting a first pawl having an oval hole in the width direction of the slot between the superconducting field coil and the wedge, and inserting the first pawl between the superconducting field coil and the first pawl. By inserting a second pawl having an H hole that communicates with the oval hole of the first pawl, it is possible to smoothly circulate helium in the slot, resulting in the effect of improving cooling performance. It will be done.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a first clamping member attached to the rotor of a superconducting rotating electrical machine according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a plan view of the invention. A plan view showing a second nail according to ':JI! J4 diagram is the third
5 is a sectional view showing the flow of helium according to the present invention, FIG. 6 is a sectional view showing the slot portion according to another example of the present invention, and FIG. 7 is a sectional view of the conventional persimmon. FIG. 8 is a longitudinal cross-sectional view showing a rotor of a general superconducting rotating electrical machine, FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 1, and FIG. hfJ9 is a cross-sectional view showing the longitudinal direction inside a conventional slot. In the figure, (2) coil mounting shaft, (31 superconducting field coils, αη slot), @i first tab, and @key second tab. In addition, in the figure, the same symbol Ji+the same minus sign or a corresponding part is shown.

Claims (2)

[Claims] (1) A superconducting field coil housed in a slot provided on the coil mounting shaft, a wedge that fixes this superconducting field coil, and a wedge inserted between this wedge and the superconducting field coil that extends in the slot width direction. a first claw having an oval-shaped hole; a second claw having a through hole that is inserted between the first claw and the superconducting field coil and communicating with the oval-shaped hole of the first claw; A rotor for a superconducting rotating electrical machine characterized by comprising: (2) A rotor for a superconducting rotating electric machine according to claim 1, wherein the diameter of the through hole of the second pawl is larger than the width of the oval-shaped hole of the first pawl.