JPH08247183A - Flywheel emergency stop device - Google Patents

Abstract

PURPOSE: To provide a device capable of emergency-stopping a large capacity flywheel for power storage device. CONSTITUTION: An injection port 25 for injecting liquid (water) for improving frictional force to flywheels 14, capable of effectively removing heat generated by the frictional force, and having high specific heat and high latent heat of vaporization into stacked casings 15 for individually housing the flywheels 14 mounted to a main shaft 1 provided on the same axis as a power generating motor 10 into plural stages, and vertically connected into the stacked state, is provided on the lowermost casing 15. Moreover, a discharging port 28 for discharging gas evaporated by frictional heat or liquid whose temperature is raised is provided on the uppermost casing 15. Large brake force can be generated by an inexpensive device in a short time, emergency stop can be performed, and damage of the device, to be generated by frictional heat can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel emergency stop device which is supported by a high temperature superconducting magnetic bearing and stores electric power by its rotating power to perform an emergency stop of a flywheel rotating at high speed. .

[0002]

2. Description of the Related Art An electric power storage device for storing electric power using a flywheel comprises a rotating body, a container, a bearing unit and a power transmission device, and stores electric power by inertia energy of a rotating flywheel. It is something that is done. During power storage, that is, when the flywheel is rotating at high speed, in order to reduce wind loss and bearing loss as much as possible,
A rotating body such as a flywheel or a generator-motor that is given a rotating force by a flywheel in order to give a rotating force to store electric power to the flywheel or to take out the stored electricity in a rotating flywheel to the outside is A high-temperature superconducting magnetic bearing, which can be operated in a vacuum state and supports these rotating bodies, consumes less electric power and can generate a large bearing force.

FIG. 2 is a longitudinal sectional view showing an example of an electric power storage device using this flywheel. A rotor 2 is attached to the upper part of the main shaft 1, and a stator 3 is arranged around the outer peripheral surface of the rotor 2 with a space therebetween. Also, a backup upper ball bearing 5 is supported above and below the rotor 2 by a cylindrical case 6 provided along the outer peripheral surface of the stator 2 at the center of a disk 7 having a fixed peripheral edge.
And a high temperature superconducting radial bearing 4 supported by a bearing stand 8 provided at the center of a base plate 9 fixed to the lower end of the case 6 and facing a permanent magnet 12 provided on the outer peripheral surface of the spindle 1.
Are attached to support the upper part of the main shaft 1 to form the generator motor 10 as a whole.

Further, the upper end of the cylindrical case 6 is sealed by an upper lid 11, and the inside of the generator motor 10 except the gap between the permanent magnet 12 and the high temperature superconducting radial bearing 4 is covered with the case. 6 and the base plate 9 completely seal it. Further, on the lower side of the main shaft 1 extending downward from the high temperature superconducting radial bearing 4 portion, hubs 13 are fitted on the outer peripheral surface of the main shaft 1 over a plurality of stages at equal intervals. A flywheel 14 is attached to the. Hereinafter, for simplicity of explanation, a combination of the hub 13 and the flywheel 14 attached to the hub 13 is referred to as a disk.

Permanent magnets 12 are attached along the bottom surface of each stage hub 14 and the attachment surface to the spindle 1. A bearing stand 16 supported by a cylindrical casing 15 that encloses the outer circumference of the disc is provided below the hub 13 of each stage. The casing 15 and the bearing stand 16 are provided. The disk rotation space is defined by. The outer circumference of the uppermost disc is the base plate 9
The casing 15 'is provided so as to extend downward from the bottom face of the disk, and the base plate 9, the casing 15', and the bearing base 16 form a disk rotation space.

The bearing base 16 is provided with a high temperature superconducting magnetic bearing 17 which is disposed to face the bottom surface of the hub 13 and the permanent magnet 12 disposed on the mounting boss for the main shaft 1 and which supports thrust force and radial force. It is set up. Therefore, except for the gap formed between the high temperature superconducting magnetic bearings 17 and the permanent magnets 12 provided above and below the rotating spaces of the discs other than the uppermost disc, the casing 15 and the bearing stand 16 are excluded.
Will be completely sealed.

The rotating space of the uppermost disk is formed between the upper permanent magnet 12 and the high temperature superconducting radial bearing 4 and communicates with the inside of the generator motor 10 and the lower permanent magnet. 12 and high temperature superconducting magnetic bearing 1
Excluding a gap formed between the base plate 9, the base plate 9, a casing 15 ′ suspended from the bottom surface of the base plate 9, and the bearing base 1.
The structure is sealed by 6.

Inside the bearing stands 8 and 16, high temperature superconducting radial bearings 4 and high temperature superconducting magnetic bearings 17 are respectively provided.
Cooling, cooling, injection for injecting liquid nitrogen, outlet 19
An enclosed space 18 is defined. Further, a lower lid 20 that closes the lower end of the casing 15 is provided below the lowermost bearing stand 16, and the main shaft 1 is provided at the center of the lower lid 20.
Is provided with a backup lower ball bearing 21 that supports the lower end of the.

As described above, the flywheel 14, which is supported by the high-temperature superconducting magnetic bearing 17 and rotates together with the main shaft, is used to store electric power or to generate electric power by the inertia energy of the flywheel 14. In the above, the generator motor 10 is used as an electric motor to rotate the flywheel 14, and as described above, the inertia energy of the flywheel 14 is used to store electric power. At the time of discharging the electric power, the inertia energy of the rotating flywheel 14 causes The generator motor 10 is operated as a generator to discharge the stored electric power. Further, at the time of an emergency stop of the flywheel 14, the flywheel 14 of the electric power storage device which is currently considered has a small capacity and is planned for discharging electric power in a short time. It is possible to make an emergency stop within a short time by braking with, and no special consideration is given to an emergency stop device.

However, when the current power storage device like a test plant is put to practical use for long-term power generation, it is necessary to increase the capacity of the flywheel 14, and therefore, for power discharge in a short time. It is considered that the current generator / motor has a small braking force and cannot be stopped for a short time. Further, in a normal mechanical brake that brakes a rotating body, the inertia energy of the flywheel 14 is too large and it is difficult to apply it for emergency stop.

[0011]

SUMMARY OF THE INVENTION As described above, the present invention stores and rotates electric power, which is expected to pose a problem when a power storage device using a flywheel is put into practical use. An object of the present invention is to provide a flywheel emergency stop device capable of stopping the rotation of a flywheel having a large amount of inertial energy in a short time.

[0012]

Therefore, the flywheel emergency stop device of the present invention has the following means. (1) In order to stop the flywheels which are mounted on the outer circumference of the main shaft and are rotating at high speed within a short time, the rotation sections of the flywheels of each stage are formed, respectively, and are connected vertically to be stacked. Inside the cylindrical casing, an inlet for injecting a liquid having high specific heat such as water and a high latent heat of vaporization is provided in the lower casing, and an outlet for discharging gas inside the casing is provided in the upper casing. Provided.

It is preferable that the casing provided with the injection port is provided along the outer periphery of the lowermost flywheel, and is provided in the lowermost casing that forms the rotation section of the flywheel. Further, it is preferable that the casing provided with the exhaust port is provided along the outer circumference of the uppermost flywheel, and is provided in the uppermost casing that forms a rotation section of the flywheel.

Further, another flywheel emergency stop device of the present invention has the following means in addition to the above (1). (2) The inlet provided in the lower casing is provided at a height near the upper end of the flywheel that rotates inside the casing.

[0015]

According to the flywheel emergency stop device of the present invention, by means of (1) above, (1) when an emergency stop of the flywheel is required, the inside of the casing below the flywheel rotates from the inlet. By injecting a liquid with high specific heat such as water and high latent heat of vaporization, the rotating flywheel is soaked, the loss of liquid and flywheel surface increases rapidly due to viscous friction, and the speed of the flywheel decreases rapidly. And can be stopped within a short time. Further, by injecting the liquid into the lower casing, the injected liquid is less likely to flow out and diffuse into the inside of the other casing in which the other flywheel is rotating, and the liquid in the state of liquid is reduced. The operation with the flywheel can be enhanced, and the braking force can be increased.

Further, the gas evaporated by the frictional heat can be made to flow into the upper casing in which the other flywheel is rotating so that a braking force can be generated by the flywheel and an inlet is provided. It is possible to suppress the pressure increase in the existing casing, increase the liquid injection amount, and increase the braking force. Also, the loss generated by viscous friction is converted to heat and absorbed by the liquid to raise the temperature of the liquid or generate steam, but since a liquid with high specific heat such as water and high latent heat of vaporization is used, It is possible to absorb a large amount of heat, reduce the temperature rise due to the emergency stop of the flywheel, and prevent local heat generation or mechanical destruction due to heat. Furthermore, as the injected liquid evaporates less and the liquid is retained, as described above,
The braking force of the flywheel can be increased.

Further, as the flywheel is urgently stopped, the generated steam is discharged from the exhaust port provided in the upper casing, so that the inside of the device does not become a high pressure, and the mechanical pressure It is possible to prevent such breakage, and it is possible to continuously inject the liquid into the casing.

In addition to the above-mentioned (1), the flywheel emergency stop device of the present invention adopts the above-mentioned means (2), and (2) at the initial stage of injecting liquid from the inlet into the casing, Since the inside of the casing has a high vacuum, the injected liquid becomes a splash and almost all is gas,
Although the frictional force with the flywheel does not become large, the injection liquid that has splashed is vaporized by installing the injection port in the casing near the top of the flywheel that rotates inside the casing that provides the injection port. Before it starts, it operates the flywheel to generate braking force. As a result, it is possible to increase the braking efficiency at the initial stage of injecting the liquid, and it is possible to shorten the time for stopping the flywheel.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an emergency stop device for a flywheel according to the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a power storage device having an embodiment of a flywheel emergency stop device according to the present invention.
Note that, in FIG. 1, the same reference numerals as those in FIG. 2 are the same members as those described in FIG.

In FIG. 1, of the casings 15 ′, 15 in which the flywheels 14 of the power storage device 50 are assembled in a plurality of stages and are vertically connected, a plurality of casings 15 ′, 15 are stacked in the lowermost casing 15. Is provided with a water injection port 25, and a water injection pipe 26 is connected to the water injection port 25. A valve 27 is provided in the middle of the water injection pipe 26.

The water injection port 25 provided in the casing 15 is attached from the upper end of the flywheel 14 rotating inside the casing 15 to the hub 13 fitted on the outer peripheral surface of the main shaft 1 and the outer periphery of the hub 13. A liquid having high specific heat and high latent heat of vaporization such as water is injected into the flywheel 14, that is, the radial direction of the disk. In addition, as in the present embodiment, the injection port 25 is the casing 15 at the bottom.
However, it is not always necessary to limit the casing 15 to the lowermost stage.

Further, the uppermost casing 15 'of the casings, that is, the lowermost case 15 of the generator-motor 10, is hung from the bottom surface of the base plate 9 for fixing the lower end of the casing 6 to form the uppermost disk rotation section. An exhaust port 28 is provided in the casing 15 ′, and an exhaust pipe 29 connected to an exhaust device (not shown) is attached to the exhaust port 28. An exhaust valve 30 is provided in the exhaust pipe 29.

The exhaust port 28 is most preferably provided in the casing 15 'in which the uppermost flywheel 14 is incorporated, but it is not necessarily limited to the casing 15'. Furthermore, as described above, in order to reduce windage loss of the rotating bodies that rotate at high speed, such as the disks of each stage and the rotor 2 of the generator motor 10, the power storage device 50.
Although the inside of the container is set to a high vacuum during operation, the exhaust port, the exhaust pipe, and the exhaust device used for creating this vacuum may be used as the exhaust port 28, the exhaust pipe 29, and an exhaust device (not shown).

Since the flywheel emergency stop device of the present invention is constructed as described above, the water injection enters in the direction of the arrow,
The inside of the casing 15 is filled up, the loss of heat is taken away to raise the temperature, evaporate or become high-temperature water, which is discharged from the exhaust port 28. That is, when an emergency stop of the flywheel 14 occurs, by opening the valve 27, the water having high specific heat and high latent heat of vaporization has a height near the upper end of the flywheel 14 that rotates internally. From the injection port 26 provided in the casing 15, it is injected into the casing 15 in the form of a splash. This water in the form of splash acts on the flywheel 14 to generate an initial braking force before being vaporized.

When water is continuously injected into the casing 15 whose high vacuum is broken by the water injection, the rotating flywheel 14 and the disk including the hub 13 are immersed in the liquid, and the viscosity of the liquid and the disk surface is increased. Due to friction
The rotation loss suddenly increases, the speed of the flywheel 14 is rapidly reduced, and the flywheel 14 can be stopped within a short time.

Further, inside the lowermost casing 15,
By injecting water, the injected water does not immediately flow out and diffuse into the inside of the upper casing 15 in which the other flywheel 14 is rotating, and the lowermost disc immediately By being immersed in water, the braking force of the flywheel 14 increases. Also, the gas evaporated by frictional heat is
The other flywheel 14 flows into the rotating upper casing 15 to generate a braking force on the flywheel, and the casing 1 having the inlet 25 is provided.
It is possible to suppress the pressure increase in 5 and to inject water smoothly, and to increase the braking force.

Further, the loss caused by friction is converted into heat and absorbed by water to raise the temperature of the water or generate steam, but the water can absorb a large amount of heat, so the flywheel 14 can be stopped in an emergency. It is possible to reduce the accompanying temperature rise and prevent local heat generation or mechanical destruction due to heat.

Also, when the flywheel 14 is urgently prevented, the generated steam or high-temperature water is discharged from the exhaust port 28 provided in the upper casing 15, so that the inside of the device becomes high in pressure. In addition, mechanical breakdown due to pressure can be prevented, and water can be continuously injected into the casing 15.

[0030]

As described above, according to the flywheel emergency stop device of the present invention, due to the structure described in the claims, it is possible to obtain a large braking force in a short time with an inexpensive device in an emergency. In addition, water can be used to stop the flywheel with high inertia energy during high-speed rotation in a short time without causing a secondary disaster due to local heat generation prevention or mechanical damage. Therefore, as the power storage device is scaled up, the effect of contributing to the improvement of safety and reliability of the required device is great.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a power storage device including an embodiment of a flywheel emergency stop device according to the present invention.

FIG. 2 is a vertical cross-sectional view of a power storage device.

[Explanation of symbols]

 1 main shaft 2 rotor 3 stator 4 high temperature superconducting magnetic bearing 5 upper ball bearing for backup 6 case 7 bearing base 8 bearing base 9 base plate 10 generator motor 11 upper lid 12 permanent magnet 13 hub 14 flywheel 15 casing 16 bearing base 17 17 high temperature Superconducting magnetic bearing 18 Space 19 Injection, outlet 20 Lower lid 21 Backup lower ball bearing 25 Water injection port 26 Water injection pipe 27 valve 28 Exhaust port 29 Exhaust pipe 30 Exhaust valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yutaka Kawashima 1-1-1, Niihama, Arai-machi, Takasago, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Works (72) Tatsuya Sato 2-1-1, Niihama, Arai-cho, Takasago, Hyogo Prefecture No. 1 Mitsubishi Heavy Industries, Ltd. Takasago Plant (72) Inventor Masaharu Minami 2-1-1 Niihama, Arai-cho, Takasago-shi, Hyogo Prefecture Mitsubishi Heavy Industries Ltd. Takasago Research Institute (72) Makoto Takenaka, Niihama, Arai-cho, Takasago-shi, Hyogo Prefecture No. 1 in Mitsubishi Heavy Industries Takasago Research Center

Claims (2)

[Claims] 1. A flywheel emergency stop for stopping in a short time the rotation of a flywheel, which is mounted in a plurality of stages on the outer periphery of a main shaft provided with a generator motor in the upper part and stores electric power by a rotational force. In the device, each of the flywheels is rotated internally, and the high specific heat is applied inside the vertically-connected and laminated cylindrical casings,
A flywheel emergency stop device characterized in that an injection port for injecting a liquid with high latent heat of vaporization is provided in the lower casing, and an exhaust port for exhausting gas in the casing is provided in the upper casing. 2. The flywheel emergency stop device according to claim 1, wherein the inlet is provided in the casing near an upper end of the flywheel which rotates inside.