JPH0446070B2 - - Google Patents

Description

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

[Background of the invention]

FIG. 2 shows a conventional example of a rotor for a superconducting rotating electric machine. As shown in the figure, there is a superconducting field winding (hereinafter referred to as field winding) 2 fixed to a torque tube 1 in the center of the rotor, and the field winding 2 is cooled with liquid helium. used in the state The outer periphery of the field winding 2 is covered with a helium container wall 3, a radiation shield 4 is provided on the outside with a vacuum layer in between, and a normal temperature damper 5 is provided on the outside of the radiation shield 4 with a vacuum layer further in between. Room temperature damper 5
has the same function as the damper winding in a conventional generator. An extension shaft 7 is attached to the end of the rotating shaft 6 that supports the torque tube 1 and the room-temperature damper 5, and there is a slip ring 8 for supplying excitation current thereon, and a helium supply/discharge device 9 is installed at the end of the shaft. The rotor supplies liquid helium and discharges helium (evaporative refrigerant) that has been gasified inside the rotor.
Helium tank (refrigerant tank) in the center of the rotor
At 10, while the rotor is rotating, the liquid helium is separated from the vaporized gas helium by centrifugal force to form a free surface 11.

After liquid helium accumulates in the helium tank 10 in the rotor configured in this manner, a flow is generated through the flow hole 12 of the torque tube 1 due to the thermosiphon effect in the centrifugal force field, and the field winding 2 is Cool efficiently. Furthermore, in the heat exchanger 13 which is a part of the helium gas discharge path, a self-pumping effect occurs because the helium gas absorbs the heat conducted from the end of the torque tube 1 and becomes close to room temperature. This has the effect of reducing the pressure within the tank 10 and lowering the equilibrium temperature of the liquid helium within the tank 10, which in turn has the effect of helping to improve the performance of the field winding 2. As described above, the rotor of the conventional structure exhibits various excellent performances under steady operating conditions in which helium is accumulated.

However, the process of lowering the temperature of the entire rotor from room temperature to a temperature at which the field winding 2 can be excited in a superconducting state (referred to as precooling) has the following disadvantages. That is, since the field winding 2 is located in the deepest part of the helium tank 10, the liquid helium injected from the helium injection pipe 14 immediately evaporates during the pre-cooling process, directly cooling the field winding 2. from the first outlet 16 to the discharge pipe 1
Pass through 5 and exit the helium tank 10. As a result, the portion of the torque tube 1 that is directly cooled by the heat exchanger 13 is well cooled, and the field winding 2 is cooled by the cold heat transferred from the torque tube 1, so that the precooling time is reduced. It gets long.

[Purpose of the invention]

The present invention has been made in view of the above points,
It is an object of the present invention to provide a rotor for a superconducting rotating electrical machine that enables shortening of the precooling time of superconducting field windings.

[Summary of the invention]

That is, the present invention includes a refrigerant tank, a torque tube connected to a rotating shaft, and a superconducting field winding fixed to the torque tube, and the refrigerant tank has a free surface of liquid refrigerant therein. A rotor of a superconducting rotating electric machine, which is formed in the rotor of a superconducting rotating electric machine, and is provided with a first outlet for discharging the evaporative refrigerant on the inner diameter side of the free surface, and a discharge pipe leading to the outside is connected to the first outlet. , a second outlet for discharging the evaporative refrigerant is provided on the same diameter or outer diameter side as the field winding, and the second outlet is connected to the outlet and the end thereof is located on the inner diameter side of the free surface. In addition, the first outlet is provided with a controllable valve that closes during precooling of the rotor and opens during operation. This feature allows the evaporative refrigerant to exit from the superconducting field winding to the outside through the second outlet during precooling.

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. An embodiment of the invention is shown in FIGS. 1 and 3. FIG. Note that parts that are the same as those in the conventional system are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, a second outlet 17 for discharging the evaporative refrigerant is provided with the same diameter as the field winding 2, and the second outlet 17 is connected to the outlet 17 and its end is located on the inner diameter side of the free surface 11. An outlet pipe 18 opened into the exhaust pipe 15 is provided at the first outlet 16, and a controllable valve 19 is provided at the first outlet 16 to close during precooling of the rotor and open during operation. By doing this, during precooling, the evaporated refrigerant flows out from the field winding 2 through the second outlet 17, making it possible to shorten the precooling time of the field winding 2. A rotor for a superconducting rotating electric machine can be obtained.

That is, in addition to the first outlet 16, a second outlet 17 is provided on the side of the field winding 2 (may be on the outer diameter side of the field winding 2), and from here the outlet pipe 18 is connected to the discharge pipe 1.
5, the outlet 20 of which opened on the inner diameter side of the rotor relative to the free surface 11 of the liquid helium when the rotor was in operation. A controllable valve 19 was then provided at the outlet of the discharge pipe 15. By doing this, if the valve 19 is closed during precooling, the liquid helium injected from the helium injection pipe 14 will immediately evaporate, but the evaporated gas helium will pass through the flow hole 12 and directly connect the field winding 2. After cooling, the discharge pipe 15 is passed through the hole 20a of the discharge pipe 18 and the outlet 20.
I started going out to In this case, only the ends of the field winding 2 are cooled, but the superconducting wire that makes up the field winding 2 contains copper for stabilization in an amount more than twice the volume of the superconducting wire. In addition, since the superconducting wire is wound in a saddle shape or a race track shape to form the field winding 2, the transfer of cold and heat within the field winding 2 is very easy, and the field winding 2 is efficiently This reduces the pre-cooling time. After the liquid helium starts to accumulate after pre-cooling, the valve 19 is opened to guide the gas helium evaporated from the free surface 11 to the discharge pipe 15, but the outlet 20 is located inside the liquid level to be set in the helium tank 10. Therefore, there is no interference in setting the liquid level due to liquid helium overflowing from the outlet 20. In addition, in the same figure, 21 is a tank side wall.

By the way, superconducting generators are mainly considered to be used as turbine generators, and when starting a steam turbine, in order to warm up the turbine, it is turned at 5 to 25 rpm before starting full-scale operation. enter. Pre-cooling of the rotor of the superconducting generator is also carried out in parallel with this warm-up operation, but in the case of a two-pole turbine generator, the rotation speed is 3000 rpm.
Alternatively, it is operated steadily at 3600 rpm, or 1500 rpm or 1800 rpm in the case of a 4-pole machine. Therefore, as shown in FIG. 3, the valve 19 is composed of a valve body 22 and a spring 23, and the spring 23 is
The structure is such that the closing operation is performed by pushing 2 in the inner diameter direction. The strength of this spring 23 is set so that the valve 19 closes at a rotation speed of 5 to 25 rpm during turning, and opens at a rotation speed of 1500 rpm or more during steady operation. This is very easy considering the fact that it is proportional to the square of the number of rotations. Of course, the valve 19 having this structure can be applied not only to a generator combined with a steam turbine but also to other types of generators equipped with a turning device.

〔Effect of the invention〕

As described above, in the present invention, the superconducting field winding is directly cooled by the evaporative refrigerant during precooling, so that the precooling time of the superconducting field winding is shortened, and the precooling of the superconducting field winding is It is possible to obtain a rotor for a superconducting rotating electrical machine that enables time reduction.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional side view around the superconducting field winding of an embodiment of the rotor of the superconducting rotating electric machine of the present invention, and FIG.
The figure is a longitudinal sectional side view of the non-drive side of the rotor of a conventional superconducting rotating electric machine, and FIG. 3 is a longitudinal sectional side view of the area around the valve of an embodiment of the rotor of the superconducting rotating electric machine of the present invention. 1... Torque tube, 2... Superconducting field winding, 3
…Helium container wall, 6…Rotation shaft, 7…Extension shaft, 1
0... Helium tank (refrigerant tank), 11... Free surface, 12... Communication hole, 13... Heat exchanger, 14... Helium injection pipe, 15... Discharge pipe, 16... First outlet, 17... Second Outlet port, 18... Outlet pipe, 19...
Valve, 20... Outlet, 20a... Hole, 22... Valve body, 23
…spring.

Claims (1)

[Scope of Claims] 1. A torque tube having a refrigerant tank and connected to a rotating shaft, and a superconducting field winding fixed to the torque tube, the refrigerant tank having a liquid refrigerant therein. A superconducting rotating electrical machine in which a free surface is formed, a first outlet for discharging the evaporative refrigerant is provided on the inner diameter side of the free surface, and a discharge pipe leading to the outside is connected to the first outlet. In the rotor, a second outlet for discharging the evaporative refrigerant is provided on the same diameter or outer diameter side as the field winding, and the second outlet is connected to the outlet and has an end thereof on the inner diameter side of the free surface. an outlet pipe opened in the discharge pipe, and a controllable valve that is closed during precooling of the rotor and opened during operation is provided at the first outlet. A rotor for a superconducting rotating electric machine characterized by the following. 2. The valve is composed of a valve body and a spring that presses the valve body, and the valve body is movable in the radial direction of the rotor, and the spring is activated during the precooling when the rotor is rotating at a low speed. Claim 1, wherein the force is set to push the valve body in an inner radial direction to close the first outlet port, and to open the first outlet port during the steady operation at high speed. A rotor of the superconducting rotating electrical machine described above.