JPS62213564A - 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 of slot 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, and a helium flowing hole 23 communicating with the slot bottom groove 23. In this case, a first lower filler 25 inserted between the coil 3 and the bottom of the slot 17 and having a plurality of through holes 25a and a second lower filler 26 inserted between the filler 25 and the bottom of the slot 17 and having an elliptical through hole 26a of slot lateral direction communicating with the slot bottom groove 24 are provided. Thus, heat can be rapidly removed at any position of the coil 3 to eliminate a normal conduction transition.

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]

As a conventional rotor of this type, for example, Japanese Patent Application Laid-Open No. 57-2237
The structure disclosed in Publication No. 2 is shown in FIG. In Figure 5, (1) is the torque tube, (2
) is the coil mounting shaft that forms the center part of the torque tube (11), (3) is the superconducting field coil fixed to the coil mounting shaft (2), and (4) is the torque tube +11 and the coil mounting shaft (2). ), (6) is a low temperature tamper disposed between this normal vA tamper (4) and the coil mounting shaft (2), (6) and (7) are the coil mounting shaft (
2) a helium outer cylinder and a helium end plate attached to the outer peripheral part and side part, respectively, (8) and (9) are the drive side,
The non-drive side end axes, (lO) are these end axes (81, +
Bearing that supports 9+, (Ri is a slip ring for supplying field current, (I2) is a heat exchanger formed or placed on the torque tube (1), ■ is a side radiation shield, θ is a vacuum Department.

In the rotor of the superconducting rotating machine having the above configuration, the superconducting field coil (
By cooling the superconducting field coil (3) to an extremely low temperature, the electric resistance becomes zero and excitation loss is eliminated, thereby generating a strong magnetic field in the superconducting field coil (3), which causes the stator (Fig. (not shown) generates AC power. This superconducting field coil (
3) is cooled to an extremely low temperature and held there.Ninth, liquid helium is introduced from the center of the non-drive side end shaft (9) through an introduction pipe (not shown) to the helium outer cylinder (6) and the helium end plate ( 7) While supplying liquid helium to the liquid helium container formed by 2) The torque tube +11 that transmits rotational torque to is made into a thin-walled cylinder,
In addition, a heat exchanger (+2) is provided, and this torque tube [1
) The most common structure is to reduce the amount of heat that enters the cryogenic area as much as possible. Furthermore, side radiation shields H are provided to reduce heat entering due to radiation from the sides.

On the other hand, the room temperature tamper (4) and the low temperature tamper (5) 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 tamper (4) functions as a vacuum outer cylinder, and the low temperature tamper functions as a radiation shield for the helium container. In FIG. 5, piping constituting a helium introduction and discharge system inside the rotor and a helium introduction and discharge device connected to the rotor are omitted.

Fig. 6 is a cross-sectional view taken along the line ■-■ in Fig. 5, that is, the one shown, for example, in JP-A-57-202852. In the figure, (2) is the coil mounting axis, and (3) is the superconducting field. Magnetic coil, [fi)ti Helium outer cylinder, 0 is liquid helium reservoir, H is helium vapor space, a7) Formed on the shaft (2) with Vi microcoil and houses the superconducting field coil (3) The slot and the bet are the side tabs placed on both sides of the slot (17), (11 is the wedge and wire that fixes the superconducting field coil (3), and (company) is the superconducting field coil (3). The upper and lower claws are arranged on the upper and lower sides, respectively, and have, for example, circular through holes (20a) and (21m), respectively.The coil mounting shaft (2) and Helium flow path provided between helium outer cylinder +81, ■ indicates liquid reservoir 0 and slot 0η
The helium flow hole (to) is an axial slot bottom groove provided at the bottom of the slot Oη to communicate with the helium flow hole (to). The helium flow hole and the through hole (21m) of the lower pawl (2) are communicated through the helium flow hole.

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 to below the superconducting transition temperature), and currently, helium is used as a cooling medium to maintain an absolute temperature of IN to 20 KlC.

On the other hand, in such an extremely low temperature state, the specific heat of the superconducting field coil is extremely small, so the superconducting field coil is reduced 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 of the coil will rise and exceed the superconducting temperature. Therefore, the design of a superconducting rotating electrical machine depends on how quickly the slight amount of heat generated in the superconducting field coil or the amount of heat that enters the superconducting field coil can be removed to suppress the temperature rise of the superconducting field coil. This is the important point above.

Next, the cooling operation will be explained based on FIGS. 7 and 8. Loss of heat occurs due to slight heat generation within the superconducting field coil (3) or slight heat intrusion into the superconducting field coil (3).
It is absorbed by helium existing in a small gap around the superconducting field coil (3). The helium, which expands due to heat absorption and has a lower density, passes through the through hole (21 m) of the lower part Tsumemo Co., Ltd. due to the natural convection of the centrifugal force field, and passes through the helium flow hole of the coil mounting shaft (2). Through the liquid reservoir part 05
). On the other hand, the helium shortage that occurs when the superconducting field coil (3) is turned is caused by passing through the helium flow path through the wedge (1-inch gap and the through hole (20 m) in the upper pawl) and turning the superconducting field coil (3). The endothermically expanded helium is cooled by evaporation of a portion in the liquid reservoir aF9.

The cooled helium enters the area around the superconducting field coil (3) through the through hole (21a) of the lower part (2) through another helium flow hole, and then flows into the upper part (2).
The helium flow path (20 m) exits through the through hole (20 m) of dl and the gap between the wedge α.

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. 7, the lower pawl c! The through hole D (21 m) is located at the center of the slot αη, and the superconducting field coil (3
) Helium flow is poor at the corners.゛If the superconducting field coil (3) generates heat at the corner, the helium that has absorbed the heat will quickly flow through the through hole (21m) of the lower part and the helium distribution hole to the liquid reservoir U5). It was difficult for the superconducting field coil (3) to leak out, but the temperature of the superconducting field coil (3) would rise and normal conductivity would occur, which would likely cause the generator to stop functioning.

This invention was made in the ninth attempt to solve the above-mentioned problems, and its purpose 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. do.

[Means for solving problems]

A rotor of a superconducting rotating electric machine according to the present invention has a first lower pawl having a plurality of through holes inserted between a superconducting field coil and a slot bottom, and a first lower pawl having a plurality of through holes. A second lower pawl having an oval-shaped through hole in the width direction of the slot communicating with the through hole of the first lower pawl and the slot bottom groove is inserted between the slots.

[Effect]

In this invention, the first lower pawl is provided with a plurality of through holes, and the second lower pawl is provided with an oval-shaped through hole in the slot width direction that communicates with the through hole of the first lower pawl and the slot bottom groove. This allows for smooth helium flow within the suction chamber.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In figures 3 to 3, 4 indicates superconducting field coil (3)
and the first lower pawl inserted between the base of the slot 9η and the first lower pawl ('8j) and having a plurality of through holes (2Sa); The second lower pawl has a through hole (25a) in the first lower pawl and an oval-shaped through hole (26a) in the slot width direction that communicates with the slot bottom g (end). The lower part is composed of the first part of the lower part and the second part of the part.

Next, the operation will be explained. Figure 3 shows the state of flow of helium in the slot (17), and the helium flowing in the radial direction in the slot (17) passes through the through hole (25 m) of the first lower part (2), and passes through the second hole (25 m). It is collected in the oval-shaped through hole (26a) of the lower pawl (support) and flows in the width direction of the slot. The oval-shaped through hole (26
The helium that has passed through a) flows into the helium flow hole through the slot bottom groove (to) and reaches the liquid reservoir portion u[9. On the other hand, helium flow hole 17 from the liquid reservoir Kasumi! The helium that has flowed into the slot l passes through the slot bottom groove □□□, flows into the oval-shaped through hole (26a) of the second lower pawl (a), flows in the slot width direction, and flows into the fourth part of the first lower pawl. Through hole (25&
) and flows around the superconducting field coil (3),
It passes through the through hole (2 oa) in the upper pawl and the gap between the wedge H and exits into the helium channel.

In this way, heat is quickly removed at any position of the superconducting field coil (3), and normal conduction transition does not occur, making it possible to prevent the generator from stopping. In addition, the first lower pawl (c) and the second lower pawl (2I1g) are members that also serve as electrical insulation, and the insulation creepage distance 1 is as shown in Figure 4. The total thickness of the second lower pawl (a) of the lower pawl (4), the oval-shaped through hole (26 m) of the second lower pawl (4)
and the dimension of the through hole (25a) of the first lower pawl. By constructing the lower pawl with two pieces (support), the insulation creepage distance can be increased by B without increasing the thickness, and the dielectric strength is improved.

〔Effect of the invention〕

The present invention has been described above] A first lower pawl having a plurality of through holes is inserted between a superconducting field coil and a slot bottom, and a first lower pawl having a plurality of through holes is inserted between the slot bottom and the first lower pawl. By inserting a second lower pawl having an oval-shaped through hole in the width direction of the slot that communicates with the through hole of the first lower pawl and the slot bottom groove, smooth helium flow within the slot is achieved. The effect of improving cooling performance can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view of a rotor of a superconducting rotating electrical machine according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line T in FIG. 1.
FIG. 3 is a cross-sectional view of the slot portion according to the present invention, FIG. 4 is a cross-sectional view of essential parts showing the first and second lower parts according to the present invention, and FIG. Fig. 6 is an N-side view taken along the line ■-■ in Fig. 5, Fig. 7 is a sectional view showing the longitudinal direction inside the conventional slot, and Fig. 8 is a cross-section of the conventional slot part. It is. In the figure, (2) is the coil mounting shaft, (3) is the superconducting field coil, αη is the slot, @ is the helium flow hole, (to) is the slot bottom groove, (to) is the first lower pawl, is the second lower pawl. 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 having a plurality of through holes, and between the slot bottom and the first lower pawl; Rotation of a superconducting rotating electric machine characterized by comprising a second lower pawl inserted into the first lower pawl and having an oval-shaped through hole in the width direction of the slot communicating with the through hole of the first lower pawl and the slot bottom groove. Child.