JPH0417561A - Superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To maintain the temperature and the pressure inside a rotor stably by curving one part of an emergency exhaust pipe into U shape in the outside diameter direction of a rotor, and connecting a branch pipe, which has branched off from a refrigerant gas exhaust pipe, to this U-shaped curve. CONSTITUTION:One end of an emergency ehaust pipe 31 is connected to a pressure discharge valve 30, and the other end is connected to a refrigerant storage 19. One part of the emergency exhaust pipe 31 is curved in U shape in the outside diameter direction of a rotor 13, and a branch pipe 32, which has branched off from the refrigerant gas exhaust pipe 20, is connected to the U-shaped curve 32. Gas helium 22, which has evaporated in the refrigerant storage 19, is discharged from a refrigerant supply and discharge device 28 to outside, and also it passes the U-shaped curve 32 and is discharged to outside from a branch pipe 33 through a refrigerant gas exhaust pipe 20.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a superconducting rotating electric machine.

(Prior Art) In recent years, so-called superconducting rotating electrical machines that utilize superconducting conductors as rotating field windings have been developed.

In order to maintain a superconducting state in this superconducting rotating electrical machine, it is necessary to cool the field winding to an extremely low temperature (about 4°C) using a coolant such as liquid helium or liquid nitrogen.

For this reason, a refrigerant storage section is provided inside the rotor, and the refrigerant stored in this refrigerant storage section is vaporized by the heat generated by the field windings and heat entering from the outside, and becomes refrigerant gas. During steady operation, the refrigerant gas vaporized in the refrigerant storage section is collected by the refrigerant supply and discharge device installed at the end of the rotating shaft while cooling the torque tube and current leads. When the refrigerant changes to a normal conducting state due to an increase in temperature, current, etc., the field winding generates heat and the refrigerant rapidly vaporizes due to its small latent heat of vaporization, causing an abnormal increase in the pressure within the refrigerant storage section.

When the pressure inside the refrigerant storage section 1 suddenly rises abnormally, it is difficult to recover the refrigerant gas in a short time using a normal recovery loop. The pressure is released through an exhaust pipe 2 to the outside from a pressure release valve 4 provided at the end of the rotating shaft 3. In the figure, 5 is a rotor, 6 is a field winding, 7 is a refrigerant, 8 is a refrigerant gas, and 9 is a refrigerant gas exhaust pipe.

However, the emergency exhaust pipe 2 has a refrigerant storage section 1 on the extremely low temperature side (about 400℃) and a pressure release valve 4 on the normal temperature side (about 300℃).
Therefore, in addition to heat intrusion due to thermal conduction, there is also heat intrusion due to natural convection, which causes a problem of large heat loss. Therefore, in order to prevent the intrusion of heat due to natural convection, conventionally the emergency exhaust pipe 2 has been constructed with a large number of thin tube elements 10 as shown in FIG. A portion of the rotor 5 is curved in a U-shape in the outer diameter direction of the rotor 5.

(Problem 8 to be solved by the invention) However, when the emergency exhaust pipe 2 is composed of a large number of thin tube elements 10, the refrigerant gas in the pipe is influenced by a high-speed rotating field, and the influence is different from that of normal gravity. It is well known both theoretically and experimentally that the centrifugal force in the field is much larger than in a tube placed perpendicular to the direction of the centrifugal force, and it is extremely difficult to prevent heat intrusion due to natural convection. Ta.

On the other hand, if a part of the emergency exhaust pipe 2 is curved in a U-shape in the direction of the outer diameter of the rotor 5, natural convection inside the pipe can be suppressed to some extent due to the relationship between the centrifugal force field and the temperature field. During steady operation, mechanical energy is generated from the temperature difference in the refrigerant gas, and the gas particles in the emergency exhaust pipe 2 cause self-excited vibrations called thermal oscillations, causing convection to occur due to the self-excited vibrations of the gas particles. .

The present invention was made in view of the above-mentioned problems, and its purpose is to prevent heat from entering the rotor even if thermal oscillation occurs in the emergency exhaust pipe during steady operation. An object of the present invention is to provide a superconducting rotating electric machine that can maintain stable temperature and pressure.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a rotor that houses a superconducting field winding therein and has a refrigerant storage section that cools the field winding. a stator provided around the rotor, a rotating shaft that drives the rotor, a refrigerant supply pipe that supplies refrigerant to the refrigerant storage section, and a refrigerant gas vaporized in the refrigerant storage section that supplies the refrigerant gas to the outside. In the superconducting rotating electrical machine, the superconducting rotating electric machine is equipped with a refrigerant gas exhaust pipe for discharging refrigerant gas to A part of the exhaust pipe is curved in a U-shape in the direction of the outer diameter of the rotor.
A branch pipe branched from the refrigerant gas exhaust pipe is connected to the letter-shaped curved part.

(Function) According to the above configuration, the refrigerant gas vaporized in the refrigerant storage section during steady operation passes through the U-shaped curved part of the emergency exhaust pipe and is discharged to the outside via the refrigerant gas exhaust pipe from the branch pipe. Even if thermal oscillation occurs in the emergency exhaust pipe between the connection point of the branch pipe and the pressure release valve, the intrusion of heat due to thermal oscillation can be prevented, and the temperature and pressure inside the rotor can be kept stable.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing a schematic configuration of a superconducting generator. A stator 12 and a rotor 13 are housed in a housing 11 of the superconducting generator. The stator 12 is arranged concentrically around the outer periphery of the rotor 13 with a space therebetween, and is fixed to the housing 11 by a support member 14.

On the other hand, the rotor 13 has an outer cylinder 15 having a damper function.
and the torque tube 1 provided inside this outer cylinder 15.
6, and a superconducting field winding 17 is housed inside the torque tube 16. Further, a refrigerant storage section 19 is provided at the center of the torque tube 16 to store liquid helium 18 as a refrigerant. One end of a refrigerant gas exhaust pipe 20 and a refrigerant supply pipe 21 are connected to this refrigerant storage section 19, so that gas helium 22 vaporized in the refrigerant storage section 19 is discharged to the outside through the refrigerant gas exhaust pipe 20. ing. In addition, the torque tube 16 and the outer cylinder 1
5, a thermal radiation shield 23 is provided to prevent heat from entering from the outside.

Rotating shafts 24A and 24B are connected to both ends of the rotor 13, and are rotatably supported by the /1 housing 11 via bearings 25, respectively. A collector ring 27 for supplying field current to the superconducting field winding 17 through a current lead 26 is provided at the end of the rotating shaft 24A, and a refrigerant supply/discharge device (helium transfer coupling) 28 is provided. ing. The other end of the refrigerant supply pipe 21 is connected to this refrigerant supply/discharge device 28, and the liquid helium 17 sent from the refrigerant supply/discharge device 28 is transferred to the refrigerant supply pipe 21.
1 and is supplied to the refrigerant storage section 19.

On the other hand, a flange 29 connected to a power generation turbine (not shown) is provided at the end of the rotating shaft 24B, and a pressure release valve 3 for emergency release of the pressure inside the refrigerant storage section 19 is provided.
0 is set. One end of an emergency exhaust pipe 31 is connected to the pressure release valve 30, and the other end of the emergency exhaust pipe 31 is connected to the refrigerant storage section 19. In addition, the above emergency exhaust pipe 3
As shown in FIG. 2, a part of the rotor 1 is curved in a U-shape in the outer diameter direction of the rotor 13, and a branch pipe 33 branched from the refrigerant gas exhaust pipe 20 is connected to the U-shaped curved part 32. is connected.

In the superconducting generator configured as described above, the gas helium 22 vaporized in the refrigerant storage section 19 during steady operation is discharged to the outside from the refrigerant supply/discharge device 28 through the refrigerant gas exhaust pipe 20, and the refrigerant gas exhaust U-shaped bend 32 of tube 20
The refrigerant gas passes through the branch pipe 33, passes through the refrigerant gas exhaust pipe 20, and is discharged to the outside.

Therefore, even if thermal oscillation occurs due to a temperature difference in the gas helium 22 in the emergency exhaust pipe 31 between the connection point of the branch pipe 33 and the pressure release valve 30, the branch pipe 33
emergency exhaust pipe 31 from the connection point to the refrigerant storage section 19
Since gas helium 22 is flowing inside, it is possible to prevent convection due to thermal isolation from reaching the refrigerant storage section 19 against the flow of gas helium 22. Therefore, heat convection due to thermal oscillation can be prevented, and the temperature and pressure inside the rotor can be kept stable.

Although liquid helium was used as the refrigerant in the above embodiment, liquid nitrogen or the like may also be used. Further, in the above embodiments, the case where the present invention is applied to a superconducting generator has been described, but the present invention is not limited to this, and can also be applied to a superconducting motor.

[Effects of the Invention] As explained above, the present invention provides a rotor that houses a superconducting field winding therein and has a refrigerant storage section that cools the field winding, and a rotor provided around the rotor. a stator, a rotating shaft that drives the rotor, a refrigerant supply pipe that supplies refrigerant to the refrigerant storage section, a refrigerant gas exhaust pipe that discharges refrigerant gas vaporized in the refrigerant storage section to the outside, and the refrigerant In a superconducting rotating electrical machine equipped with a pressure release valve that releases refrigerant gas in the refrigerant storage to the outside through an emergency exhaust pipe when the pressure in the storage rises abnormally, a part of the emergency exhaust pipe is connected to the rotor. It is curved into a U-shape in the outer diameter direction, and a branch pipe branched from the refrigerant gas exhaust pipe is connected to this U-shaped curved part. Therefore, during normal operation, the refrigerant gas vaporized in the refrigerant storage section passes through the U-shaped curved part of the emergency exhaust pipe and is discharged from the branch pipe to the outside via the refrigerant gas exhaust pipe, so that pressure is released from the connection point of the branch pipe. Even if thermal oscillation occurs in the emergency exhaust pipe leading to the valve, the intrusion of heat due to thermal oscillation can be prevented, and the temperature and pressure inside the rotor can be kept stable.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a superconducting generator, FIG. 2 is a sectional view showing a part of the rotor, and FIGS. 3 to 5 are FIG. 2 is a diagram for explaining a conventional technique. 11...Housing, 12...Stator, 13...
Rotor, 17... Superconducting field winding, 18... Liquid helium, 19... Refrigerant storage section, 20... Refrigerant gas exhaust pipe, 21... Refrigerant supply pipe, 22... Gas Helium, 24A, 24B...Rotating shaft, 27...Selector ring, 28...Refrigerant supply/discharge device, 30...Pressure release valve, 31...Emergency exhaust pipe, 32...U-shape curved part,
33... Branch pipe.

Claims (1)

[Claims] A rotor having a refrigerant storage section for storing a superconducting field winding therein and cooling the field winding, a stator provided around the rotor, and a rotating shaft for driving the rotor. a refrigerant supply pipe that supplies refrigerant to the refrigerant storage; a refrigerant gas exhaust pipe that discharges the refrigerant gas vaporized in the refrigerant storage to the outside; A superconducting rotating electric machine equipped with a pressure release valve that releases refrigerant gas to the outside through an emergency exhaust pipe,
A superconducting rotation characterized in that a part of the emergency exhaust pipe is curved in a U-shape in the outer diameter direction of the rotor, and a branch pipe branched from the refrigerant gas exhaust pipe is connected to this U-shaped curved part. Electric machine.