JPS63294253A - Supply and discharge device for liquid nitrogen of superconducting rotary electric machine rotor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a nitrogen supply/discharge device for a rotor of a rotating electrical machine having a superconducting field winding excited at liquid nitrogen temperature, and in particular to a nitrogen supply/discharge device for a rotor of a rotating electric machine having a superconducting field winding excited at liquid nitrogen temperature. The present invention relates to a nitrogen supply/discharge device that supplies nitrogen from outside the rotor and guides nitrogen gas evaporated inside the rotor to the outside of the rotor.

[Conventional technology]

When a superconducting field winding using helium as a refrigerant is located on the rotor, a helium supply/discharge device as shown in JP-A-60-21.01.60 was used. In other words, when using liquid helium, strict airtightness is required mainly due to the problem of scarce resources, and the seal that maintains this airtightness is between the rotating and non-rotating bodies, so a magnetic seal with a small clearance is used. A fluid seal was used.

[Problem that the invention seeks to solve]

However, in order to meet the above requirements, a helium supply/discharge device with a relatively precise seal structure and a clearance retention mechanism using ball bearings is required, and such precision is required. Even with this structure, there were problems such as vibration and contact friction between the rotating and stationary parts due to thermal deformation of the casing when operating under cold recovery gas flow.

[Means for solving problems]

In a rotor that uses liquid nitrogen as a cooling medium, there is plenty of liquid nitrogen in the air, so there is no need to collect and reuse it, and there is no need to strictly avoid leaks or foreign debris during recovery, so the sealing mechanism is simple. can be achieved. In addition, because the latent heat of vaporization of nitrogen is 199.1 kJ/kg compared to 20.9 kJ/kg of helium, the clearance between the injection pipe on the stationary side and the introduction pipe on the rotating side of the nitrogen injection part is also extremely large. There is no need to make it smaller. Therefore, the present invention eliminates the need for a ball bearing between the casing of the nitrogen supply/discharge device and the rotor, and fixes the casing of the nitrogen supply/discharge device to the installation foundation of the rotor.

[Effect]

Since there are no ball bearings and the casing is fixed to the installation foundation, vibrations are reduced, and since the clearance is large, the rotating and stationary parts do not come into contact with each other due to vibration or deformation.

〔Example〕

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a rotor of a superconducting rotating electric machine having superconducting field windings cooled with liquid nitrogen. Field winding 1 is attached to torque tube 2. There is a vessel 3 around the field winding 1, which serves as a container for liquid nitrogen 4.

The damper 5 is the main component of the rotor between the bearings 6 and 7, and functions as an electromagnetic damper at room temperature.

A radiation shield 8 is located between the damper 5 and the vessel 3 and traps radiant heat. Evaporated nitrogen gas 9 is located at the rotor axis.
The conductive heat transmitted through the torque tube is cooled by the heat exchanger 10 and is guided to the nitrogen supply/discharge device]1. A portion of the liquid nitrogen 4 is guided to the excitation current lead 12, and the nitrogen gas evaporated there is guided to the nitrogen supply/discharge device 11- through a route different from the route passing through the heat exchanger 10.

The slip ring 1-3 supplies an exciting current to the superconducting field winding 1 from the fixed side through the exciting current lead 12.

The vibration damping bearing 14 is for suppressing vibration of the nitrogen supply/discharge device 11 portion. Liquid nitrogen injection pipe 15 is connected to casing 16
It is inserted into the nitrogen introduction pipe 17 located at the rotor axis. The casing 16 is supported from the installation foundation by a support 18. The gas led from the liquid nitrogen inlet and the exit of the heat exchanger 10, the gas led from the exciting current REET]-2, and the outside air are sealed with seals 19, 20, and 21, respectively. As the seal, a gap seal such as a labyrinth seal is used.

FIG. 2 shows a conventional helium supply/discharge device, and since a precision seal is required, ball bearings 26 and 27 are required as a mechanism to maintain clearance.

FIG. 3 shows an embodiment of the invention. The gas seal 22 used as a seal performs its sealing function by supplying pressurized nitrogen gas at room temperature from the outside through pipes 23, 24, and 25. At this time, if the gas pressure applied to the pipe 23 is made slightly lower than the pressure applied from the liquid nitrogen injection pipe 15, room temperature nitrogen gas used for sealing will enter the liquid nitrogen introduction pipe 17, causing heat loss in the liquid nitrogen. Never.

FIG. 4 shows an embodiment of the invention. By fixing the casing 16 to the damping bearing 14, the casing 1 relative to the rotor is
Mounting 6 improves accuracy and further reduces the risk of contact between the seals.

〔Effect of the invention〕

As described above, according to the present invention, a simple and robust nitrogen supply/discharge device with little vibration can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the invention. FIG. 2 shows a conventional helium supply and discharge device. FIG. 3 shows another embodiment of the invention. FIG. 4 shows another embodiment of the invention. ■...Superconducting field winding, 2...Torque tube, 3
・・Vessel, 4・Liquid nitrogen, 5・Damper, 6・
・・Bearing, 7・・Bearing, 8・・Radiation shield, 9・・
Nitrogen gas, ]. 0... Heat exchanger, 11... Nitrogen supply/discharge device, 12... Excitation current lead, 13... Slip ring, 14... Vibration damping bearing, 15... Liquid nitrogen injection pipe, 1
6...Casing, 17...Nitrogen introduction pipe, 18...
・Support, 19°20.21...Seal, 22...
Gas seal, 23°24-. 25... tube, 26.2
7...Ball bearing.

Claims (1)

[Claims] 1. In a superconducting rotating electric machine rotor having a superconducting field winding excited at liquid nitrogen temperature, a superconducting rotating electric machine rotor is fixed to a non-rotating part so as to wrap around the shaft end of the rotor. A casing and a nitrogen injection pipe fixed to the casing are arranged with a small gap from the inner diameter of the nitrogen introduction pipe arranged at the rotor axis, and the part where the casing contacts the rotor is Nitrogen supply for a rotor of a superconducting rotating electric machine, which has a device for sealing recovered evaporated nitrogen gas, and is fixedly supported from the non-rotating part side with a gap between the rotor and the rotor without using a ball bearing. Exhaust device. 2. A superconducting rotating electric machine in the nitrogen supply/discharge device according to claim 1, wherein the device for sealing the recovered evaporated nitrogen gas is a gas seal that supplies nitrogen gas at room temperature from the outside. Rotor nitrogen supply and exhaust system. 3. In the nitrogen supply/drainage device according to claim 1 or 2, the casing disposed at the end of the rotor shaft has a structure of a damping bearing disposed near the end of the rotor shaft. A nitrogen supply and exhaust device for a rotor of a superconducting rotating electrical machine, characterized in that the rotor is fixed to the rotor of a superconducting rotating electric machine. 4. In the nitrogen supply/discharge device for a rotor of a superconducting rotating electric machine according to claim 2 or 3, it is provided that the gas pressure of the gas seal separating the nitrogen supply port and the discharge port is lower than the liquid nitrogen injection pressure. Features a nitrogen supply and exhaust system for superconducting rotating electric rotors.