JPS62213561A - Rotor of superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To improve the cooling performance of a superconducting rotary electric machine by inserting first lower filler having a through hole to between a superconducting field coil and the bottom of a slot, and further inserting a second lower filler having an elliptical through hole. CONSTITUTION:The rotor of a superconductive rotary electric machine is composed of a coil mounting shaft, a superconducting field coil 3, a slot 17, a side filler 18, a helium flowing hole 23 communicating with a slot bottom groove 24, or the like. In this case, a lower filler is composed of first lower filler 25 having a plurality of through holes 25a communicating with the groove 24, and second lower filler 26 having an elliptical through hole 26a of slot lateral direction communicating with the hole 25a. Thus, heat can be rapidly removed at any position of the coil 3 to eliminate a normal conductive type transition.

Description

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

[Prior art] Conventionally, as a rotor of this type, for example, Japanese Patent Application Laid-Open No. 57-2287
There is one disclosed in Publication No. 2, and its configuration is shown in FIG. In Figure 6, (1) is the torque tube, (2
) is the coil mounting shaft that forms the center of the torque tube (1), (3) is the coil mounting shaft (2), the superconducting coil fixed to I, (4) is the torque tube (1) and the coil mounting shaft (2) is a room-temperature damper/f surrounding it, (5) is a low-temperature damper disposed between this room-temperature damper (4) and the coil mounting shaft (2), and (6) and (7) are the coil mounting shafts. Helium outer cylinder and helium end plate attached to the outer periphery and side surface of (2), respectively, (8) and (9) are drive side and non-drive side end shafts, αQ is these end shafts + 8) ,
The bearing that supports (9), Q]) is a slip ring for supplying differential current.

@ is a heat exchanger formed or placed in the torque tube (1), Q3 is a side radiation shield, and σ4 is a vacuum section.

In the rotor of the superconducting rotating machine having the above configuration, the superconducting field coil (
By cooling the superconducting coil (3) to an extremely low temperature, the electrical resistance becomes zero and excitation loss is eliminated, thereby generating a strong magnetic field in the superconducting coil (3), which generates alternating current in the stator (not shown). This superconducting field coil (
3) In order to cool and maintain the liquid helium at an extremely low temperature, liquid helium is introduced from the center of the non-drive side end shaft (9) through a tube (not shown) to the helium outer cylinder (6) and the helium end plate (7). While supplying the liquid helium to the liquid helium container formed by The tube (1) is a thin-walled cylinder,
The most common structure is to provide a heat exchanger υ to minimize the amount of heat that enters the cryogenic part through the torque tube (1). Furthermore, a side radiation seal is provided to reduce the heat that enters due to radiation from the sides.

On the other hand, the normal temperature damper (4) and the low temperature damper (S) shield harmonic magnetic fields from the stator, and superconducting field coils (
3) while also having the function of damping rotor vibrations caused by disturbances in the power system.

Generally, the normal temperature damper (4) functions as a vacuum outer cylinder, and the low temperature damper functions as a radiation shield for the helium container. In addition, in FIG. 6, the piping constituting the helium introduction and discharge system inside one rotor and the helium introduction and discharge device connected to the rotor are omitted.

Figure 11K7 is a sectional view taken along the line ■--■ in Figure 6.

For example, this is shown in Japanese Patent Application Laid-Open No. 57-202862.

In the figure, (2) is the coil mounting shaft, (3) is the superconducting field coil, (6) is the helium outer cylinder, and o! J is a liquid helium reservoir, one head is a helium vapor space, α force is a slot for storing the superconducting coil (3) formed on the coil mounting shaft (2), and (to) is on both sides of slot 04. Qll is a wedge that fixes the tag conductive field coil (3), and Qll is a wedge that fixes the tag conductive field coil (3). The lower part is filled with 1, for example, a circular through hole (2
0sz) and (20b), respectively. ＠ is a helium flow path provided between the coil mounting shaft (2) and the helium outer cylinder (6), 4 is a helium flow hole provided in communication with the liquid compressor and slot αη, and CI4 is a slot. 0
This is an axial slot bottom groove provided at the bottom of the helium flow hole Q in communication with the helium flow hole Q.
1a) are communicated with.

Generally, in superconducting rotation*a, there is an important technical problem in how to cool the superconducting field coil to a cryogenic temperature. In order to make the superconducting field coil superconducting Wfζ, it is necessary to cool it below the superconducting transition temperature, and currently, helium is used as a cooling medium to reduce the absolute temperature IK.
It is practiced to maintain the temperature between 20K and 20K. on the other hand,
In such an extremely low temperature state, the specific heat of the superconducting field coil is extremely small, so the temperature of the superconducting field coil will increase due to a small amount of heat generated within the superconducting field coil or a small amount of heat entering the superconducting field coil. There is always a risk of rising and exceeding 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 coil by quickly removing the minute amount of heat generated within the superconducting field coil or the slight amount of heat entering the superconducting field coil. This is a great point.

Next, the cooling operation will be explained based on Fig. 8, item e (gtζ). It is absorbed by the helium that exists in the small fll gap around the superconducting field coil (3).The helium, which expands due to heat absorption and becomes less dense, penetrates the lower pawl 4 due to the natural convection of the centrifugal force field. passing through the hole (21a);
It exits to the liquid reservoir through the helium flow hole of the coil mounting shaft (2). - 10,000 Helium shortage around the superconducting field coil (3) flows from the helium flow path through the gap between the wedges 4 and the through hole (20a) of the upper pawl (1) to the area around the superconducting field coil (3). supplemented by helium flowing into the 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 helium flow hole through the through hole (21a) in the lower pawl (2), and then through the through hole (20a) in the upper pawl (2). The helium flow path ■l exits through the gap between the wedge and the wedge.

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

[Problem that the invention seeks to solve]

In the rotor of a conventional superconducting rotating electric machine, as shown in FIG.
) The flow of helium is poor at the corners of the superconducting field coil (
If the heat generated in 3) occurs at the corners, it will be difficult for the helium that has absorbed the heat to quickly flow out to the liquid reservoir (c) through the three through holes (21a) of the lower jaw and the helium distribution hole (4). , there was a high possibility that the temperature of the superconducting field coil (3) would rise and a normal conduction transition would occur, causing the generator to stop functioning.

This invention was made in order to solve the problems mentioned in section t.The purpose of this invention is to smoothly remove heat from a superconducting field coil and obtain a rotor for a superconducting rotating electrical machine that does not cause normal conduction transition. do.

[First Means for Solving the Problems] The rotor of the superconducting rotating electric machine according to the present invention includes a first lower jaw having a through hole communicating with the slot bottom groove between the superconducting field coil and the slot bottom. and insert a second lower claw having an oval-shaped through hole in the width direction of the slot communicating with the through hole of the first lower claw between the superconducting field coil and the first lower claw. This is what I did.

[Effect]

In this invention, the first lower pawl is provided with a through hole that communicates with the slot bottom groove, and the second lower pawl is provided with a through hole that communicates with the slot bottom groove.
Since an oval-shaped through hole is provided in the width direction of the slot that communicates with the through hole of the lower pawl of No. 1, helium can flow smoothly within the slot.

[Example 1] An example of the present invention will be explained below. 1st
In Figures 3 to 3, (7) is a superconducting field coil (
3) and the bottom of the slot ση.

A plurality of through holes (25a) communicating with the slot bottom groove (to)
The first lower pawl (to) is inserted between the superconducting field coil (3) and the first lower pawl (7), and has a through hole (into the first lower pawl). A second lower pawl having an oval-shaped through hole (26a) in the slot width direction that communicates with the first lower pawl (25a).
7) The lower claw is constituted by the second lower claw. Next, the operation will be explained. Fig. 8 shows the flow of helium in the slot ση, and the helium flowing in the radial direction in the slot Qη is collected in the oval-shaped through hole (26a) of the second lower pawl (end) and flows in the slot width direction. The liquid flows into the through hole (25a) of the first lower pawl (A). The helium that has passed through the through hole (25a) of the first lower pawl (7) flows through the slot bottom groove (to) into the helium flow hole (to) and reaches the liquid reservoir (t). on the other hand,
Helium flowing from the liquid reservoir (G) to the helium flow hole (To) flows through the slot bottom groove (F) to the through hole (258) of the first lower pawl (A), and then flows into the second lower pawl (B). It flows into the oval-shaped through hole (26a) of the upper part (to), flows in the direction of the slot P claw, flows around the superconducting field coil (3), and flows through the through hole (20a) of the upper part (a) and the wedge α. The helium flow path (branch) exits through the two gaps, and heat is removed quickly at any position of the superconducting field coil (3), and one generator is generated without causing normal conduction transition. It is possible to prevent the outage of functions. Also, the first lower part @.

The second lower pawl (to) is a member that also has the role of electrical insulation, and the insulation creepage distance is as shown in Figures 4 and 5. The total thickness A of the lower pawl (e), the dimension of the oval-shaped through hole (26a) of the second lower pawl (to) and the first lower pawl (
The sum (A+B+C) of the difference B between the dimensions of the through hole (25a) of the first lower pawl (7) and the difference C between the dimension of the through hole (25a) of the first lower pawl (7) and the width dimension of the slot bottom groove □. expressed,
First lower part (c), second lower part (to)
By configuring the lower pawl with two sheets, the insulation creepage distance can be increased by B without increasing the thickness A, and the dielectric strength is improved.

(Effects of the Invention) As explained above, the present invention includes inserting a first lower pawl having a through hole communicating with the slot bottom groove between the superconducting field mother coil and the slot bottom.

By inserting a second lower pawl having an oval-shaped through hole in the slot width direction that communicates with the through hole of the first lower pawl between the superconducting field coil and the first lower pawl, the slot Helium can flow smoothly within the chamber, resulting in improved cooling performance.

[Brief explanation of drawings]

FIG. 1 is a plan view of a rotor of a superconducting rotating electric machine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line 1-1 in FIG. 1, and FIG. 8 is a cross-sectional view of a slot portion according to the present invention. FIG. 4 is a plan view of essential parts showing the first and second lower claws according to the present invention, FIG. 5 is a cross-sectional view taken along line v-v in FIG. 4,
FIG. 6 is a longitudinal sectional view showing a rotor of a conventional general superconducting rotating electrical machine. FIG. 7 is a cross-sectional view taken along the line v-g in FIG. 6, FIG. 8 is a cross-sectional view showing the longitudinal direction inside the conventional slot, and FIG. 9 is a cross-sectional view of the conventional slot portion. In the figure, (2) is the coil mounting shaft, (3) is the superconducting field coil, αη is the slot, and c! 3 is a helium flow hole. (Goods) is the slot bottom groove, (A) is the first lower part,
QR is the lower part of the drawer 2. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A superconducting field coil housed in a slot provided on the coil mounting shaft, a helium flow hole radially penetrating from the slot to the center of the coil mounting shaft, and a helium flow hole formed at the bottom of the slot and communicating with the helium flow hole. a slot bottom groove inserted between the superconducting field coil and the slot bottom, a first lower pawl that is inserted between the superconducting field coil and the slot bottom and having a through hole communicating with the slot bottom groove; A superconducting rotating electrical machine characterized by comprising a second lower pawl that is inserted between the lower pawl and has an oval-shaped through hole in the slot width direction that communicates with the through hole of the first lower pawl. rotor.