JP2008086095A - Superconducting flywheel device for power storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superconducting flywheel device for power storage which can secure the safety by arranging magnetic bearing parts above and below a flywheel and also can improve the efficiency by separating a flywheel part and a vacuum vessel for cryogenic temperatures. <P>SOLUTION: The superconducting flywheel device for power storage, the rotating shaft of whose flywheel is supported by a magnetic bearing composed of a superconducting coil and a superconducting bulk body and which has a motor-generator, has a low vacuum vessel 11 for suppression of windage loss where the flywheel 13 is put. The rotating shaft 8 of the flywheel 13 is supported by magnetic bearings which are constituted of superconducting coils 4, 4' and superconducting bulk bodies 9, 9' being arranged pair by pair in the vacuum vessels 7, 7' for cryogenic temperatures arranged above and below across the flywheel 13. The connection between respective vacuum vessels is sealed with a magnetic seal unit which seals the circumference of the rotating shaft with an O-ring of magnetic fluid, and it also has a cooling chamber 15, which cools the motor-generator above the rotating shaft 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a superconducting power storage system that converts surplus power into kinetic energy of a flywheel and stores it, and converts kinetic energy stored in the flywheel into electrical energy and takes it out as necessary. The present invention relates to a flywheel device, and relates to an improvement of the superconducting magnetic bearing.

  As the above-described superconducting flywheel power storage device, for example, there is one disclosed in Patent Document 1 below.

  FIG. 3 is a schematic diagram of such a conventional superconducting flywheel power storage device.

  As shown in this figure, a superconducting coil 103 arranged in a fixed state, a superconducting bulk body 104 arranged in a levitating state facing the coil, and a flywheel 105 rotating integrally with the superconducting bulk body 104, , An exhaust device 109 for evacuating the inside of the cryocontainer 101, a heat conduction type cooling device 111 for cooling the superconducting coil 103 below its critical temperature, and a flywheel A rotating shaft 106 fixed to 105 and a clutch device 113 for connecting / disconnecting the generator / motor 112 are provided. In FIG. 3, reference numeral 102 denotes a cooling plate, 107 denotes a guiding superconducting coil, 108 denotes a guiding superconducting bulk body, and 110 denotes a He compressor.

  As described above, by replacing the conventional permanent magnet with the superconducting coil 103, a larger electromagnetic force can be generated between the superconducting coil 103 and the superconducting bulk body 104. That is, since the electromagnetic force increases in proportion to the square of the magnetic field, generating a large magnetic field by the superconducting coil 103 generates a larger electromagnetic force and obtains a strong levitation force on the flywheel 105. Connected.

  In addition, a uniform magnetic field can be realized in a large space.

Furthermore, the air gap (air gap) of the bearing can be increased.
JP 2003-219581 A

  However, according to the above-described superconducting flywheel power storage device, since the radial bearing is disposed only on the lower side of the flywheel, the upper end of the rotating shaft becomes a free end and shaft runout easily occurs. Even if the lower radial bearing is strengthened, it is difficult to prevent the rotation shaft from falling down in the rigid body mode, and it is not easy to rotate it stably. Furthermore, there is a problem that the cryogenic cooling area is widened and a large amount of energy is consumed for cooling, resulting in a reduction in efficiency.

  In view of the above situation, the present invention can secure the stability by arranging the magnetic bearing portions above and below the flywheel, and can improve efficiency by separating the flywheel portion and the cryogenic vacuum vessel. An object of the present invention is to provide a superconducting flywheel device for power storage.

In order to achieve the above object, the present invention provides
[1] In a superconducting flywheel device for power storage having a rotary shaft of a flywheel supported by a magnetic bearing portion and having an electric motor / generator above the rotary shaft, a fly placed in a low vacuum vessel for controlling windage loss A cryogenic vacuum vessel disposed above and below the wheel and the flywheel is provided with a magnetic bearing portion including a set of superconducting coils and a superconducting bulk body.

  [2] In the superconducting flywheel device for power storage as described in [1] above, an O-ring made of a magnetic fluid is disposed on the periphery of the rotating shaft between the cryogenic vacuum vessel and the low vacuum vessel for suppressing windage loss of the flywheel. A magnetic seal unit for sealing with is arranged.

  [3] The superconducting flywheel device for power storage as described in [1] above, wherein the motor / generator part is covered with a container and cooled by circulating low-temperature gas as a cooling chamber.

  [4] In the superconducting flywheel device for power storage described in [1] above, the periphery of the rotating shaft is sealed with an O-ring of magnetic fluid between the cryogenic vacuum vessel and the cooling chamber of the motor / generator. A magnetic seal unit is arranged.

  [5] In the superconducting flywheel device for power storage according to [2] or [3], a bellows is disposed on an outer periphery of a magnetic seal unit that seals the periphery of the rotating shaft with an O-ring of magnetic fluid. It is characterized by.

  According to the present invention, the following effects can be achieved.

  (1) Since the magnetic bearings are arranged above and below the flywheel, the rotational stability of the rotating shaft can be ensured.

  (2) Since the flywheel and the cryogenic vacuum vessel are arranged separately, the region for cryogenic temperature can be further limited, and the energy consumption for cooling can be reduced. The efficiency of the superconducting flywheel device for power storage can be improved.

  (3) Temperature rise can be suppressed in the cooling chamber of the motor / generator disposed at the upper end of the rotating shaft.

  (4) Normally, in order to improve the adhesion between the rotating shaft and the magnetic fluid, the magnetic seal requires a high degree of clearance management for the gap between the rotating shaft and the magnetic seal magnet. Therefore, the fit between the rotating shaft and the magnetic seal unit is usually managed by a ball bearing provided in the unit portion.

  When a plurality of such seal units are arranged in series, the rotation shaft is supported at a plurality of locations and becomes unstable. For this reason, great effort is required for assembly and adjustment. Further, rotational resistance is generated in the radial direction, and the efficiency is lowered. With respect to this problem, by arranging the bellows on the outer periphery of the magnetic seal unit, no shaft restraining force is generated at the magnetic seal unit portion, and therefore, no rotational resistance is generated.

  A superconducting flywheel device for power storage according to the present invention includes a flywheel disposed in a low vacuum container for suppressing windage loss, and a set of superconducting coils in a cryogenic container disposed above and below the flywheel. And a magnetic bearing part composed of a superconducting bulk body, and the motor / generator is placed in the cooling chamber.

  FIG. 1 is a schematic cross-sectional view of a superconducting flywheel device for power storage showing a first embodiment of the present invention.

  In this figure, 1 is a frame, 2 and 2 'are high-vacuum spaces, 3 and 3' are adiabatic load supporting materials, 4 and 4 'are superconducting coils, 5 and 5' are refrigerators, and 6 and 6 'are Insulation shield, 7 and 7 'are cryogenic vacuum containers, 8 is a rotating shaft, 9 and 9' are superconducting bulk bodies, 10, 10 'and 10 "are sealed around the rotating shaft with an O-ring of magnetic fluid. A magnetic seal unit, 11 is a low vacuum vessel for windage damage suppression, 12 and 12 'are O-rings for low vacuum vessel sealing, 13 is a flywheel, 14 is an electric motor / generator, and a rotor 14A is provided at the upper end of the rotary shaft 8. In addition to direct mounting, an armature 14B is disposed, and 15 is a cooling chamber for the motor / generator.

  As described above, the magnetic bearings 10 and 10 ′ are arranged above and below the flywheel 13. Further, the low vacuum vessel 11 for suppressing windage loss for the flywheel 13 and the cryogenic vacuum vessels 7 and 7 'are arranged separately.

  Therefore, since the magnetic bearings 10 and 10 ′ are arranged above and below the flywheel 13, the rotational stability of the rotating shaft 8 can be ensured.

  Further, since the flywheel 13 and the cryogenic vacuum vessels 7 and 7 'are arranged separately, the region for cryogenic temperature can be further limited, and the energy consumption for cooling can be reduced. The efficiency of the superconducting flywheel device for power storage can be improved.

  Further, the motor / generator 14 (rotor 14A / armature 14B) disposed at the upper end portion of the rotating shaft 8 is covered with a cooling chamber 15, and a low-temperature gas for cooling is circulated in the motor / generator 14 thereby. Temperature rise can be suppressed.

  FIG. 2 is a schematic cross-sectional view of a superconducting flywheel device for power storage showing a second embodiment of the present invention.

  In this embodiment, a bellows (flexible joint) 21 is added to the outer peripheral portion of the magnetic seal unit (magnetic bearing) 10, 10 ', 10 "shown in the first embodiment to suppress wind loss of the flywheel 13. Between the low vacuum vessel 11 and the cryogenic vacuum vessel 7, 7 ′ of the magnetic bearing 10, 10 ′, 10 ″, and between the cryogenic vacuum vessel 7 of the magnetic bearing 10, 10 ′, 10 ″ and the mount 1 As a result, the magnetic seal unit does not become a resistance against the driving of the rotating shaft 8. The rotating shaft penetrating portion of each vacuum vessel has a magnetic fluid O on the periphery of the rotating shaft. Seal with a ring.

  In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.

  The superconducting flywheel device for power storage of the present invention can be used as a superconducting flywheel power storage device that improves stability and efficiency.

It is a cross-sectional schematic diagram of the superconducting flywheel device for electric power storage which shows 1st Example of this invention. It is a cross-sectional schematic diagram of the superconducting flywheel device for electric power storage which shows 2nd Example of this invention. It is a cross-sectional schematic diagram of a conventional superconducting flywheel power storage device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2, 2 'High vacuum state space 3, 3' Adiabatic load support material 4, 4 'Superconducting coil 5, 5' Refrigerator 6, 6 'Thermal shield 7, 7' Cryogenic vacuum vessel 8 Rotating shaft 9 , 9 'Superconducting bulk material 10, 10', 10 "Magnetic seal unit (magnetic bearing)
DESCRIPTION OF SYMBOLS 11 Low-vacuum container for windage loss 12,12 'O-ring for low-vacuum container seal 13 Flywheel 14 Electric motor / generator 14A Rotor 14B Armature 15 Cooling chamber of electric motor / generator 21 Bellows (flexible joint)

Claims (5)

In the superconducting flywheel device for power storage having a rotary shaft of the flywheel supported by a magnetic bearing portion and having an electric motor / generator on the rotary shaft,
(A) a flywheel disposed in a low vacuum vessel for windage damage suppression;
(B) A superconducting fly for power storage, comprising a pair of superconducting coils and a superconducting bulk body in a cryogenic vacuum vessel placed above and below the flywheel. Wheel device.   2. The superconducting flywheel device for power storage according to claim 1, wherein a magnet that seals the periphery of the rotary shaft between the cryogenic vacuum vessel and the low vacuum vessel for suppressing windage loss of the flywheel with an O-ring of magnetic fluid. A superconducting flywheel device for power storage, comprising a seal unit.   2. The superconducting flywheel device for power storage according to claim 1, wherein the motor / generator portion is covered with a container and cooled by circulating low-temperature gas as a cooling chamber.   2. The superconducting flywheel device for power storage according to claim 1, wherein a magnetic seal unit for sealing the periphery of the rotating shaft with an O-ring of magnetic fluid is provided between the cryogenic vacuum vessel and the cooling chamber of the motor / generator. A superconducting flywheel device for power storage, characterized by being arranged.   The superconducting flywheel device for power storage according to claim 2 or 3, wherein a bellows is disposed on an outer periphery of a magnetic seal unit for sealing the periphery of the rotating shaft with an O-ring of magnetic fluid. Superconducting flywheel device.

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