JPS58201558A - Superconductive rotor - Google Patents

Abstract

PURPOSE:To obtain a superconductive rotor which has a liquid helium tube having small heat loss by providing a radiation heat shield around a coolant filling tube. CONSTITUTION:A radiation heat shield 16a is provided around a liquid helium filling tube 13. The shield 16a is provided with a shield cylinder 17 so as to contact with at least part of the shield cylinder 17 of good thermal conductivity and with a branch pipe 18 which branches gas helium evaporated in a liquid helium reservoir 9. In this manner, the cylinder 17 is cooled by the helium which flows through the pipe 18 to lower the temperature. Thus, the radiation heat to the tube 13 can be reduced, thereby decreasing the heat loss of the tube 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superconducting rotor, and more particularly to a superconducting rotor having a rotating shaft, a torque tube, a superconducting field winding, a refrigerant reservoir, a refrigerant injection pipe, and the like.

A conventional example of a superconducting rotor is shown in FIG.

As shown in the figure, a superconducting field winding l is fixed on a torque tube 2, and the ends of the torque tube 2 are supported by rotating shafts, that is, shafts 3 and 4. A bearing journal portion 5 is provided on the shaft 3 and the shaft 4.
and 6 are provided to form a bearing support section. A vacuum insulation layer is provided between the superconducting rotor ill and the outer cylinder 7 at normal temperature, and a radiation shield 8 is placed in between. The superconducting field winding 1 is cooled by direct current of liquid helium in a refrigerant reservoir, that is, a liquid helium reservoir 9, to a winding portion 10. In the liquid helium reservoir 9, liquid helium evaporates due to heat entering from the outside, and the evaporated gas helium cools the end of the torque tube 2 and the power lead (not shown), and then flows out as indicated by the arrow in the figure. The helium supply/discharge device 12 discharges the gas to the outside of the machine as a gas flow IL as shown in FIG. Liquid helium is supplied to the liquid helium reservoir 9 through a refrigerant injection pipe, that is, a liquid helium injection pipe 13, and liquid helium is supplied to the liquid helium injection pipe 13 from outside the machine by a helium supply/discharge device 12. The slip ring 14 supplies excitation current to the power leads from an external power source (not shown).

In the superconducting rotor 15 configured in this way, the radiation shield 8 is arranged around the liquid helium reservoir 9 as described above, and the radiation shield 8 is arranged around the liquid helium reservoir 9 to suppress the amount of heat intrusion (heat transfer amount) from the room temperature part to the cryogenic part. Although reduced, liquid helium injection tube 1
3 does not have such a shield, and the amount of heat that can withstand infiltration into the liquid helium injection tube 13 is limited to a large superconducting rotor of the size shown in FIG.
When calculated for the superconducting rotor of the O generator, the following values are obtained, and the amount of heat that can withstand infiltration into the liquid heliwam injection pipe 13 is large.

The amount of heat Q that can withstand infiltration between concentric cylinders is expressed as follows (1). Here, σ is the Stefan Polzmann constant,
L is the length of the heat transfer surface, ε1. ε is the diameter of the small diameter side and the large diameter side, D,, D is the diameter of the small diameter side and the large diameter side, T
I and T2 are the temperatures on the small diameter side and the large diameter side. This blanket vs. car ε1. Both ε2 are set to 0.2, and the temperatures T, , T
, the temperature T1 of the liquid helium injection tube 13 on the small diameter side is set to 4.2K over the entire length, and the temperature T2 of the torque tube 2 on the large diameter side is set at 4.2K at the connection part from the low temperature side to the shaft 4. It is distributed like a quadratic curve up to 300K, so 4.
Assume that the temperature distribution is quadratic from 2K to 300K,
Similarly, the temperature T2 of the shaft 4, which is on the large diameter side, is set to 300 over the entire length up to the tip of the superconducting rotor 15. As shown in the figure, the diameter DI of the liquid helium injection tube 13 on the small diameter side is 15cm, and the diameter DI of the torque tube 2. The diameters D2 of the large and small parts of the shaft 40 are 600, 200, and 20 m, respectively.
n, and the length L of the heat transfer surface of the torque tube 2. The large and small portions of shaft 4 are 700, 1500, and 1500 days, respectively. From the above equation (1), these D2 are 600 m (L
= 700 pieces), 200 fins (L = 1500 pieces), 20 m (
The total amount of heat penetration resistance ΣQ is approximately 10W by adding the obtained results together.

As described above, the amount of heat that can withstand infiltration into the liquid helium injection tube 13 is large, and therefore the liquid helium injection tube 13 has a drawback that the heat loss is large.

The present invention has been made in view of the above points, and its object is to provide a superconducting rotor having a liquid helium injection tube with low heat loss.

That is, the present invention is characterized in that a radiation heat shield is provided around the refrigerant injection pipe.

The present invention f will be explained below based on the illustrated embodiments.

FIG. 3 shows an embodiment of the invention. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted.

In this embodiment, a radiation heat shield 16at- is provided around the liquid helicum injection pipe 13. And radiation heat shield 1
6a from a shield cylinder 17 that is a good thermal conductor, and a diversion pipe 18 that is provided so that at least a part of the outer periphery of the shield cylinder 17 contacts, and that diverts the gas helicum evaporated in the liquid helium reservoir 9. Formed.

By doing this, the shield cylinder 17 is cooled by the diverted gas helium flowing through the diverter vibe 18 and its temperature is lowered, and the amount of heat that can withstand infiltration into the liquid helium injection pipe 13 can be reduced. Heat loss of the injection pipe 13 can be reduced.

Incidentally, the temperature of the radiation heat shield 16a is 4.2 on the low temperature side.
Assuming that the temperature reaches 300K on the high temperature side, and the temperature distribution from the low temperature side to the high temperature side changes like a quadratic curve, (1)
From the formula, the amount of heat resistant to infiltration into the liquid helium injection pipe 13 ΣQ
is 1.2W, and compared to the conventional liquid helium injection tube 13
heat loss can be significantly reduced.

If we set T=4.2 in equation (1), this radiation heat penetration resistance increases in proportion to the fourth power of T2 (that is, the temperature of the radiation heat shield 16a), so the temperature of the entire radiation heat shield 16a is lowered. The heat penetration resistance can be significantly reduced. For example, the radiation heat shield 16a
If the temperature on the high temperature end side is 100, and the temperature distribution in the axial direction is quadratic from 4.2K on the low temperature end side, then
The temperature of the radiation heat shield 16a as a whole decreases, and the radiation resistant infiltration heat amount ΣQ becomes very small at 0.014W.

Another embodiment of the invention is shown in FIG.

In this embodiment, the radiation heat shield 16b is formed from a shield cylinder 17 of a good thermal conductor and a branch pipe 18. Supported through. That is, the high temperature end sides of the shield cylinder 17 and the branch pipe 18, which are good thermal conductors, were connected to the rotor structure 20 via the insulator 19, respectively. In this case, the thermal resistance of the insulator 19 is very high, so the radiation heat shield 1
A large temperature difference is created between 6b and the rotor structure 20,
By lowering the temperature of the radiation heat shield 16b, it is possible to obtain a temperature distribution in the low temperature range required for the radiation heat shield 16b, and it is possible to reduce the amount of heat that can withstand infiltration of the liquid into the vryme injection pipe 13 compared to the above case. .

FIG. 5 shows yet another embodiment of the invention. In this embodiment, the radiant heat shield 16C is formed of a concentric shield cylinder 16C that is a non-thermal conductor, and between which the gas helium evaporated in the liquid helium reservoir is diverted.

In this way, since the shunt gas helium was made to flow through the shield cylinder 16C, which is a non-thermal good conductor, the shield cylinder 1
6C has poor heat conduction, radiation heat shield 16 (4-
It is possible to reduce the amount of heat permeation resistance that is conducted.

FIG. 6 shows yet another embodiment of the invention. In this embodiment, the radiation heat shield 16d is formed from a shield cylinder 17 and a branch pipe 18, which have good thermal conductivity and whose high-temperature end side is connected to the rotor structure 20 through an insulator 19, respectively. Insulators 19 were interposed at multiple locations in the axial direction of 17. In this way, the temperature of the entire radiation heat shield 16d can be lowered even more than when the insulator 19 is interposed on the high temperature end side.

In addition, in the figure, 21 is a magnetic fluid seal.

FIG. 7 shows yet another embodiment of the invention. Radiation heat shield 16e'i Shield cylinder 17 of good thermal conductor
and a branch pipe 18, and an opening A that communicates with the gas helium channel 11a inside the rotor structure 20 was provided near the axial end of the branch pipe 18. In this way, the low-temperature diverted gas helium flowing through the diverter pipe 18 mixes through the opening A into the gas flow 11 indicated by the arrow in the figure after the torque tube has been cooled. The mixed branch gas helium cools the torque tube, and the gas helium that has become the gas flow 11 and has flowed through the gas flow path 11a is in a large amount and almost at room temperature, so that the temperature becomes room temperature. Therefore, the diverted gas helium becomes gas helium at room temperature and is recovered by the helicum supply/discharge device 12, so the magnetic fluid seal 21, which is a sealing mechanism between the rotating part and the stationary part, is exposed to the low temperature diverted gas helium. Therefore, it is possible to prevent the negative influence of the low-temperature shunt gas helium on the magnetic fluid seal 21.

As described above, the present invention provides a radiation heat shield around the refrigerant injection pipe, so radiation heat to the refrigerant injection pipe is shielded, reducing the amount of heat penetration resistance and reducing heat loss. A superconducting rotor with a small liquid helium injection tube can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of a conventional superconducting rotor, Fig. 2 is a longitudinal side view of the bending of the refrigerant injection pipe for calculating the amount of heat that can withstand infiltration into the refrigerant injection pipe of a conventional superconducting rotor, and Fig. 3 7 are longitudinal sectional side views of bent refrigerant injection pipes showing different embodiments of the superconducting rotor of the present invention. 1... Superconducting field winding, 2... Torque tube, 3
...Rotating shaft, 9...Refrigerant reservoir, 11a...Gas helium channel, 13...Refrigerant injection pipe, 16a, 16b,
16C. 16d, 16e... Radiation heat shield, 17... Shield cylinder of good thermal conductor, 18... Diversion pipe, 19.
...(1 other person) $z zu imo 4 zu 2 憬! 1,000,500 shares

Claims (1)

[Claims] 1. A rotating shaft, a torque tube connected to the rotating shaft, a superconducting field winding disposed on the outer periphery of the torque tube, and a superconducting field winding disposed within the torque tube, and In a superconducting rotor having a refrigerant reservoir storing a refrigerant for cooling the superconducting rotor ll1i and a refrigerant injection pipe supplying the refrigerant to the refrigerant reservoir, a radiation heat shield is provided around the refrigerant injection pipe. A superconducting rotor characterized by: 2. The radiation heat shield is provided with a shield cylinder that is a good heat conductor, and at least a part of the shield cylinder is in contact with the outer periphery of the shield cylinder, and a diversion pipe that divides the edge of the gas evaporated in the refrigerant reservoir. A superconducting rotor according to claim 1, which is formed from. 3. The superconductor according to claim 1, wherein the radiation heat shield is formed of a concentric shield cylinder that is a non-thermal conductor and which separates the gas helium evaporated in the refrigerant reservoir. rotor. 4. The radiation heat shield is formed from the shield cylinder of the good thermal conductor and the branch pipe, and the high temperature end sides of the shield cylinder and the branch pipe are connected to the rotor structure through an insulator, respectively. A superconducting rotor according to certain claims 1 and 2. 5. The radiation heat shield is formed of the shield cylinder of the good thermal conductor and the branch pipe, each of which is connected to the rotor structure at its high-temperature end side via an insulator, and the shield cylinder of the good thermal conductor is A superconducting rotor according to claims 1 and 4, wherein insulators are interposed at a plurality of locations in the axial direction. 6. The radiation heat shield is formed of the concentric and non-thermal conductive shield cylinder, and the high temperature end side of the shield cylinder is connected to the rotor structure via an insulator. The superconducting rotor according to the range jI1 term and 93 term. 7. The radiation heat shield is formed from the shield cylinder made of a good thermal conductor and the branch pipe or the concentric shield cylinder made of a non-thermal good conductor, and from which the shield cylinder is formed from the branch pipe or the shield cylinder made of a non-thermal good conductor near an axial end thereof. To,
Claims 1 and 2 are provided with an opening that communicates with the gas helium flow path inside the rotor structure.
The superconducting rotor according to items 1 and 3.