JPH0530138B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling device for a rotating electrical machine, and more particularly to a cooling device for a rotating electrical machine that can control the gas pressure of hydrogen gas sealed as a cooling medium.

[Background of the invention]

BACKGROUND ART Hydrogen gas is used to cool the interior of a rotating electrical machine operated at high speed, such as a turbine generator, in order to reduce windage loss. Furthermore, in order to further reduce windage loss, a cooling gas pressure control method has been proposed in which the gas pressure is lowered during light loads when the amount of heat generated is small.

However, conventional devices require increased equipment and energy consumption for gas pressure control, and the overall improvement in efficiency is small.

That is, the conventional device shown in FIG. 3 supplies hydrogen gas from a hydrogen cylinder 2 to a generator main body 1 via a gas supply pipe 3, and discharges excess gas inside the machine into the atmosphere from a gas discharge pipe 4. It is. a gas flow control valve 5 provided in the middle of the pipes 3 and 4;
Reference numeral 6 controls the gas pressure inside the machine, and the gas flow control valve 5 opens when the gas pressure inside the machine drops below the target value to replenish hydrogen gas and maintain the gas pressure inside the machine at the target value. gas flow control valve 6
is opened when it is desired to lower the target value of gas pressure under light load to discharge excess gas inside the machine and lower the gas pressure to the target value.

The conventional device shown in FIG. 4 further includes a tank 8 connected to the generator main body 1 via a pipe 7, and a compressor 9 and a gas flow control valve 10 placed in the middle of the pipe 7 are used to remove excess gas. The gas is stored in a tank 8, and the stored gas in the tank 8 is returned to the cabin when necessary.

The conventional equipment shown in Figure 3 consumes a large amount of hydrogen gas and is uneconomical, while the equipment shown in Figure 4 requires the addition of a tank 8 and a compressor 9, making the equipment complex and complicated. The power consumption of the compressor 9 is large and uneconomical.

[Purpose of the invention]

An object of the present invention is to provide a cooling device for a rotating machine that economically controls the hydrogen gas pressure inside the machine.

[Summary of the invention]

In order to achieve this object, the present invention provides a rotating electrical machine including a fan that circulates hydrogen gas sealed as a cooling medium within the rotating electrical machine, and a hydrogen gas cooling cooler provided in the hydrogen gas circulation path. A cooling device comprising: a tank containing a hydrogen storage alloy; a gas supply passage connecting the tank and the inlet to a high-temperature/high-pressure gas region and a low-temperature/high-pressure gas region of the hydrogen gas circulation path; and an outlet of the tank. A gas return passage connected to the low-pressure gas region of the hydrogen gas circulation path and a gas flow control valve arranged in these passages are provided, and when the load is reduced, low-temperature hydrogen gas is sent into the tank to cool the hydrogen storage alloy. By doing so, it absorbs hydrogen and lowers the gas pressure inside the aircraft.
When the load increases, high-temperature hydrogen gas is pumped into the tank to heat the hydrogen storage alloy, which releases hydrogen and increases the gas pressure inside the aircraft, controlling the hydrogen gas pressure according to the load condition. It is economically viable.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG. Hydrogen gas sealed within the generator body 1 is energized by a fan 12 provided on the rotor 11 and circulates within the generator in the direction of the arrow. Hydrogen gas cooling cooler 1
3 is disposed in this hydrogen gas circulation path, cools the armature winding and the field winding, and passes the high temperature hydrogen, cools it and returns it to the back of the fan 12. As a result, in the hydrogen gas circulation path inside the machine, the outlet area 14 of the cooler 13 is a low-temperature/low-pressure gas area, the discharge area 15 of the fan 12 is a low-temperature/high-pressure gas area, and the inlet area 16 of the cooler 13 is a low-temperature/low-pressure gas area.
is a high-temperature, high-pressure gas region.

The tank 17 contains a hydrogen storage alloy 18. The hydrogen storage alloy 18 is generally a lanthanum-rich rare earth-nickel-aluminum alloy, which has the property of generating heat and absorbing hydrogen when cooled, and conversely, absorbing heat and releasing hydrogen when heated. . And this hydrogen storage alloy 18
In order to increase the contact area with the hydrogen gas in the tank, those processed into fibers or porous materials are used. The inlet 17a of the tank 17 is connected to the high temperature of the hydrogen gas circulation path via the gas supply pipe 19.
It is connected to the cooler inlet region 16 where high-pressure gas exists, and is also connected via a gas supply pipe 20 to the discharge region 15 where low-temperature, high-pressure gas exists. Further, the outlet 17b of the tank 17 is connected via a gas return pipe 21 to the cooler outlet area 14 where low temperature and low pressure gas exists. A gas flow control valve 22 is installed in the middle of these pipes 19 to 21.
~24 are provided.

The gas flow control valves 22 - 24 are controlled by sensing the generator load condition by measuring the magnitude of the generator load current or field current or the gas temperature in the cooler inlet region 16 . In a normal load state, the gas flow control valves 22 and 24 are opened and the gas flow control valve 23 is closed, and in a light load state, the gas flow control valve 2 is closed.
3 and 24 and close the gas flow control valve 22, the in-machine gas pressure is set to a target value according to the load condition of the generator.

Note that hydrogen gas is charged into the machine from a hydrogen cylinder 2 via a gas supply pipe 3, as in the conventional apparatus.

In the above configuration, hydrogen gas is filled into the machine by first evacuating the machine and the tank and then supplying hydrogen gas, or by filling the machine with carbon dioxide gas and then replacing it with hydrogen gas. The hydrogen storage alloy 18 in the tank 17 absorbs hydrogen by filling this hydrogen gas at room temperature (40° C. or lower). The hydrogen storage alloy 18 is filled in such an amount that the gas pressure inside the machine reaches the rated target value, that is, the value corresponding to the normal load state when the hydrogen storage alloy 18 releases hydrogen. Therefore, at this point, some of the hydrogen in the cabin has been absorbed by the hydrogen storage alloy 18, so the gas pressure is lower than the rated target value.

When the generator is operated, the temperature of the hydrogen gas circulating inside the machine rises. Under normal load conditions, the gas flow control valves 22 and 24 are open, so that the high-temperature, high-pressure gas in the cooler inlet region 16 flows into the tank 17 via the gas supply pipe 19 and the gas return pipe 21. Then, when the temperature reaches 60° C. to 65° C., hydrogen is released from the hydrogen storage alloy 18, and the in-flight gas pressure increases, and the in-flight gas pressure reaches the rated target value.

When the generator is under light load and the hydrogen gas pressure can be lowered, the gas flow control valve 22 is closed and the gas flow control valves 23 and 24 are opened to reduce the low temperature present in the discharge area 15. - By flowing high-pressure gas into the tank 17, the hydrogen storage alloy 18 is cooled and absorbed hydrogen, reducing windage loss by lowering the gas pressure inside the aircraft.

Furthermore, when the generator is program-controlled to be operated with a high load during the day and with a light load during the night, the in-flight gas pressure can also be program-controlled accordingly.

Further, in the case of a sudden increase in load, if the hydrogen gas pressure cannot be increased solely by releasing hydrogen from the hydrogen storage alloy 18, replenishment can be performed from the hydrogen cylinder 2.

Figure 2 shows hydrogen storage alloy 18 for the above example.
This is an example of a case where measures are taken to improve the responsiveness of the system. The heating device 25 is provided in the middle of the gas supply pipe 19 and directly heats the hydrogen gas supplied to the tank 17 to increase its temperature. The cooling device 26 is provided in the middle of the gas supply pipe 20 and directly cools the hydrogen gas supplied to the tank 17 to further lower the temperature. Further, the device 27 is for directly cooling or heating the tank 17. The addition of such devices has the effect of enhancing the absorption and release functions of the hydrogen storage alloy 18 and improving responsiveness. Furthermore, energy savings can be achieved by using the heat sources (cooling, heating) that are conventionally attached to generators.

〔Effect of the invention〕

As described above, the present invention uses a hydrogen storage alloy,
Furthermore, hydrogen is absorbed or released into the hydrogen storage alloy using the heat generated by the rotating electric machine, cooling by the cooler, and hydrogen gas circulation flow by the cooling fan, and the hydrogen gas pressure inside the machine is controlled according to the load of the generator. Therefore, there is an effect that the gas pressure can be controlled economically.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of the generator cooling device according to the present invention, Fig. 2 is a system diagram showing a modification thereof, Fig. 3,
FIG. 4 is a system diagram of a conventional generator cooling system. 1... Generator body, 12... Fan, 13...
Cooler, 14...low temperature/low pressure gas outlet area,
15... Low temperature/high pressure gas discharge area, 16...
High temperature/high pressure gas inlet area, 17...tank,
18... Hydrogen storage alloy, 19, 20... Gas supply pipe, 21... Gas return pipe, 22-24...
...Gas flow control valve.

Claims (1)

[Claims] 1. A cooling device for a rotating electrical machine that includes a fan that circulates hydrogen gas sealed as a cooling medium within the rotating electrical machine and a hydrogen gas cooling cooler provided in the hydrogen gas circulation path, which includes a built-in hydrogen storage alloy. a gas supply passage connecting an inlet of the tank to an altitude/high-pressure gas region and a low-temperature/high-pressure gas region of the hydrogen gas circulation path, respectively, and an outlet of the tank to a low-pressure gas region of the hydrogen gas circulation path. 1. A cooling device for a rotating electric machine, comprising a gas return passage connected to the passage and a gas flow control valve disposed in the passage.