JPS6037692B2 - Coolant inlet/output device for liquid-cooled rotor-type rotating electric machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid rotor type rotating electrical machine that circulates a coolant around a rotor to cool the rotor, and particularly to a coolant lead-in/out device thereof.

As is well known, in order to increase the capacity of a rotating electric machine, the problem is how to suppress temperature rise, that is, how to achieve effective cooling.

In other words, it is no exaggeration to say that the capacity of a rotating electrical machine is determined by its temperature rise, that is, its cooling performance. On the other hand, it is increasingly necessary to increase the single machine capacity of generators among rotating electric machines, especially turbine generators, from the viewpoint of improving the efficiency of power plant construction. By the way, a cooling method that circulates hydrogen gas has been used to cool turbine generators so far, and an increase in the capacity of a single unit has been achieved, but this has already reached its limit. A significant increase in capacity cannot be expected. Therefore, there is a strong desire to put another cooling method into practical use. To meet this demand,
It is conceivable to use a cooling fluid with good cooling efficiency, such as water, instead of hydrogen gas as the cooling medium. Based on this idea, it has already been proposed and realized to cool the stator by circulating the coolant, but if we can develop this and successfully circulate the coolant to the rotor. , the cooling effect can be dramatically increased. However, if we take a turbine generator as an example, the rotor usually rotates at a high speed of 3,600 revolutions per minute (60 days 2), and it is difficult to introduce coolant into such a high-speed rotating body.
And how to derive this is the biggest problem for Realization 1, and this has hindered the spread of liquid-cooled rotor type rotating electric machines.

FIG. 1 is a diagram showing a coolant inlet/output device for a liquid-cooled rotor that has been considered as a subsidiary, and 1 is an inlet pipe to which coolant, such as pure water, is supplied via a feed pump (not shown). It is.

The reason why pure water is used as a cooling liquid is as follows. The coolant is circulated within each tube and the rotor coil as described below, so if water containing impurities is used as the coolant, the impurities may cause corrosion of the tubes and rotor coil. Therefore, it is desirable to use pure water that does not contain any impurities. 2 is a cylindrical inflow pipe which has a closing part 2a and receives the cooling liquid from the inlet pipe 1 through this closing part;
The hollow interior 2b serves as an inflow path for the cooling liquid.

Reference numeral 3 denotes a circular outflow pipe provided around the inflow pipe 2 with a predetermined gap therebetween, and the gap 3b between the inflow pipe 2 and the inflow pipe 2 serves as an outflow path for the coolant.

3a is an opening □ provided at one end of this outflow pipe 3;
Coolant is discharged through this opening.

Incidentally, the outflow pipe 3 and the inflow pipe 2 are integrally connected to form a supply/discharge pipe 4 as shown in FIG. That is, in FIG. 2, 2c is a protruding piece with a plurality of axially extending strips (the figure shows a case of 6 strips) that is protruded from the outer periphery of the inflow pipe 2, and its protruding end is connected to the outflow pipe 3. is in contact with the inner circumference of That is, this protruding piece 2c serves as a spacer between the outflow pipe 3 and the inflow pipe 2.
It integrally connects the and outflow pipe 3 and also serves as reinforcement for the money exchangers 2 and 3. Inflow pipe 2 having this protruding piece 2c
and the outflow pipe 3 are firmly and integrally connected, for example, by a brazing fit or the like, to form a supply/discharge pipe 4. 4a is a flange formed at the terminal end of this supply/discharge pipe 4, and 5 is a flange 5a that closely fits this flange and is connected with, for example, bolts (not shown).
This is a rotor shaft of a rotating electric machine having a rotor shaft, and needless to say, a rotor coil (not shown) is attached to this rotor shaft.

As is clear from the figure, this rotor shaft 5 is provided with an inflow path 5b and an outflow path 5c that communicate with the inflow path 2b and outflow path 3b of the feed pipe 4, respectively. The supplied coolant circulates through the rotor coil and is then discharged to the outflow path 5c. Note that the arrows in the figure indicate the flow of the cooling liquid, and after the rotor coil is circulated and cooled as described above, it is discharged from the exit part 3a of the outflow pipe 3 via the outflows 5c and 3b. . Reference numeral 61 designates a first outlet chamber for receiving the liquid discharged from the closed portion 3a, and the chamber is always kept full of cooling liquid to prevent the cooling liquid (pure water) from coming into contact with the atmosphere and being contaminated. It is configured as follows.

71 is a first outlet chamber for discharging the cooling liquid from this first outlet chamber.
As mentioned above, the coolant drawn out from this first outlet pipe does not come into contact with the atmosphere and is not contaminated, so it is cooled by a heat exchanger (not shown) or the like before being sent. It is fed back to the inlet pipe 1 via a feed pump (not shown) and subjected to recirculation.

Reference numeral 81 denotes a first labyrinth seal for suppressing leakage of cooling liquid from inside the inlet pipe 1 to the first outlet chamber 61, and it is impossible to completely eliminate leakage between the rotating part and the fixed part. Therefore, efforts are made to minimize leakage.

This leakage is not a big problem because it is circulated again via the first outlet pipe 71 as described above, but if the leakage amount is too large, the efficiency will deteriorate, so it goes without saying that it is better to have a smaller amount. Nor. 82 is the first exit chamber 61
A second pipe is installed to prevent leakage between the pipe 4 and the rotating pipe 4.
The labyrinth seal 62 is a second outlet chamber that receives leakage from the first outlet chamber 61 that has passed through the second labyrinth seal.

This second outlet chamber 62 is different from the first outlet chamber 61 described above and is not filled with cooling liquid, so there is a risk that the cooling liquid (pure water) will come into contact with the atmosphere and be contaminated. Reference numeral 9 denotes an air supply pipe for preventing this. By constantly supplying a gas such as nitrogen or hydrogen to the second outlet chamber 62 through this air supply pipe, the second outlet chamber 62 The internal pressure is always kept slightly higher than atmospheric pressure to prevent atmospheric air from entering the second outlet chamber.

Therefore, since the liquid leaking from the second outlet chamber 62 does not come into contact with the atmosphere and is not contaminated, the coolant drawn out from the second outlet pipe 72 is similar to the coolant drawn out from the first outlet chamber 61. It is subjected to recirculation via a heat exchanger and a feed pump (none of which are shown). 83 is a third labyrinth seal for suppressing leakage between the second outlet chamber 62 and the rotating supply pipe 4, and 63 is a second outlet that has passed through the third labyrinth seal. The third chamber receives leakage from chamber 62.
73 is a third outlet pipe communicating with this third outlet chamber.

The cooling liquid reaching the third outlet chamber 63 is connected to the two-stage seal 82,
Due to the effect of
Therefore, the cooling liquid drawn out from the third outlet pipe 73 is discarded as it is without being subjected to recirculation. Of course, it is also possible to send the water to a reprocessing device, purify it, and recirculate it. By the way, in the above device,
The rotor shaft 5 is supported by a bearing (not shown), but as is clear from the figure, the supply/discharge pipe 4 cannot be provided with a bearing due to the outlet chamber, etc., and the rotor koji 5 has an overhang. It is supported in form.

For this reason, the tube E tube 4 is always exposed to the risk of wobbling. Even if the shaft runout is small, it will impair the sealing effect, and if it becomes large, it will damage the seal. Therefore, it is necessary to eliminate all causes of shaft runout. However, the above-mentioned conventional device includes the following causes of shaft vibration. That is, as described above, the gap between the inflow pipe 2 and the outflow pipe 3, which form the outflow path 3b, is separated from each other by the protruding piece 2c, as can be clearly seen from FIG. For this reason, when the outflow amount in each divided outflow path 3b becomes unbalanced, the jetting pressure when being discharged in the Z direction from the entrance portion 3a becomes non-uniform. For this reason, the force at the time of ejection is naturally unbalanced, causing the subsequent supply and discharge pipe 4 to vibrate (shake).
This invention solves the above-mentioned problem, and FIG. 3 is a sectional view showing one embodiment thereof, and FIG. 4 is a perspective view thereof.
In FIGS. 3 and 4, 2b is a long groove that cuts out a part of the protruding piece 2c and allows the adjacent outflow passages 3b on both sides of the protruding piece 2c to pass through. By aligning the adjacent outflow passages 3b divided in different directions, the difference in the pressure of the outflowing coolant due to the unbalance of the outflow amount of each outflow path is smoothed out, and the pressure between the adjacent outflow passages 3b is equalized, resulting in the overall pressure being equalized. Since it will be uniform, each outflow path 3
The ejection pressure from b can always be made uniform, and the vibration of the feed pipe 4 (
(shaft runout) can be effectively prevented. Note that it is sufficient to provide one lotus groove 2d for each protruding piece 2c, but if necessary, a plurality of grooves may be provided. In the above embodiment, the present invention is applied to a case where there are three outlet chambers, but it can be similarly applied to a case where there are two outlet chambers as shown in FIG.

That is, in FIG. 5, 612 is the outlet chamber 6 in FIG.
1 and 62 are integrated into an exit chamber, and 712 is the exit chamber 61 of the rod.
2 is a suitable outlet pipe, and 9 is an air supply pipe similar to that shown in FIG. By constantly maintaining the internal pressure at a value slightly higher than atmospheric pressure, contamination of the coolant due to contact with the atmosphere is prevented. That is, the two outlet chambers 61 and 62 in FIG. 1 are combined into one, and the cooling liquid led out from the outlet pipe 712 is provided for recirculation as in FIG. 1. Note that arrow A indicates the flow of the coolant. Further, in the above embodiment, a case is shown in which pure water is used as the coolant, but it goes without saying that other liquids than pure water may be used as long as the liquid does not corrode the tubes and the rotor coil.

Furthermore, in the above embodiments, the present invention has been explained as being applied to a generator, particularly a turbine generator, but it goes without saying that it can be applied to other generators such as a water turbine generator, as well as various rotating electric machines such as an electric motor, if necessary. do not have.

Further, in the above embodiment, a labyrinth seal is used as a seal for suppressing leakage of the coolant, but it goes without saying that other seals such as a mechanical seal may be used.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a conventional coolant inlet/output device, Fig. 2 is a cross-sectional view taken along line 01D in Fig. 1, Fig. 3 is a cross-sectional view showing an embodiment of the present invention, and Fig. 4 is a cross-sectional view showing an embodiment of the present invention. The same perspective view and FIG. 5 are diagrams for explaining another example of application of the present invention. Note that the same symbols in each figure indicate the same or equivalent parts, 1 is the inlet pipe, 2 is the inlet pipe, 2a is the opening □,
2b is an inflow path, 2c is a protruding piece, 2d is a lotus groove, 3 is an outflow pipe, 3a is its entrance, 3b is an outflow path, 4 is a supply/discharge pipe, 4a is a flanged flange, and 5 is a rotor shaft. 5a is the flange, 5b is the inflow path, 5c is the outflow path, 61, 62, 6
3,612 is an outlet chamber, 71, 72, 73, 712 are outlet pipes, 81, 82, 83, 84 are labyrinth seals, and 9 is an air supply pipe. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A circular inflow pipe whose one end is connected to the rotor shaft and which is open at the other end and introduces the cooling liquid through this opening.The inflow pipe is arranged with a gap around the outer periphery of the inflow pipe, and the cooling liquid is introduced through the gap. a circular tubular outflow pipe having one end connected to the rotor shaft and having an opening for discharging the coolant at the other end, and receiving the coolant discharged from the opening of the outflow pipe; A plurality of protruding pieces each having an outlet chamber and extending in the axial direction to protrude from the outer periphery of the inflow pipe, the tips of which are in contact with the inner periphery of the outflow pipe to partition the gap in the circumferential direction. and a communication groove is provided in a part of each of the protruding pieces by cutting out the protruding pieces, and is configured to communicate the divided adjacent gaps with each other. Coolant inlet/output device for cold rotor type rotating electric machines.