JPS6037693B2 - 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-cooled rotor-type rotating electric machine that circulates a coolant around a rotor to cool the rotor, and particularly to a coolant introduction/intake 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 (60Hz).
This is the biggest problem in realizing the derivation of this method, and this has hindered the spread of liquid-cooled rotor-type rotating electric machines.

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

The reason why pure water is used as a cooling liquid is as follows. As described below, the coolant is circulated within each tube and rotor coil, so if water containing impurities is used as the coolant, the impurities may cause each tube and rotor coil to become damaged. Therefore, it is desirable to use pure water that does not contain any impurities. 2 is a circular inflow pipe having an opening 2a and receiving the cooling liquid from the inlet pipe 1 through the entrance 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 approximate point for the outflow of the cooling liquid.

3a is a checkpoint provided at one end of this outflow pipe 3;
Coolant is discharged through this spout.

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 plurality of protruding pieces (the figure shows a case of six pieces) formed integrally with the outer periphery of the inflow pipe 2, and these protruding pieces 2c are connected to the outflow pipe 3. It serves as a spacer to integrally connect the inflow pipe 2 and the outflow pipe 3, and also serves to reinforce the exchangers 2 and 3. The inflow pipe 2 and the outflow pipe 3 having the protruding piece 2c are firmly connected together by, for example, a competitive fit, and constitute a supply pipe 4. 4a is a flange formed at the end of this supply pipe 4, and 5 is a flange 5 that is in close contact with this flange and is connected, for example, with a bolt (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.

Further, 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 the outflow path 3b of the supply/discharge 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 closed part 3a of the outflow pipe 3 via the outflow passages 5c and 3b. . Reference numeral 61 denotes an upstream outlet chamber, that is, a first outlet chamber, for receiving the discharged liquid from the barrier mouth 3a.In order to prevent the coolant (pure water) from being contaminated by contact with the atmosphere, is configured to maintain a full state.

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 labyrinth seal 62 is used to suppress leakage between the rotating supply and discharge pipe 4, and 62 is a second outlet chamber that receives liquid leakage from the first outlet chamber 61 that has passed through the second labyrinth seal. It is.

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 pressure inside the chamber 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/discharge pipe 4, and 63 is a seal from the second outlet chamber 62 that has passed through the third labyrinth seal. A downstream outlet chamber or third outlet chamber for receiving leakage liquid, 73, is a third outlet pipe adapted to be connected to 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 coolant discharged from the third outlet pipe 73 is discarded without being recirculated. Of course, it is also possible to send the water to a reprocessing device, purify it, and recirculate it. 84 is a fourth labyrinth seal for preventing the cooling liquid from leaking from the third outlet chamber to the outside of the device.

The above device can achieve the intended purpose.

By the way, 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., so it overhangs the rotor shaft 5. It will be supported in the form of Therefore, the supply/discharge pipe 4 is always exposed to the problem of wobbling. Axial runout is undesirable because it impairs the sealing effect. This axial vibration is more likely to occur as the supply/discharge pipe 4 becomes longer, so it is best to keep it short, but in the conventional device, the cooling liquid leaks from the third outlet chamber 63 to the outside of the device as described above. A fourth labyrinth seal 84 for preventing the third outlet chamber 63 from
In order to prevent the coolant from leaking to the outside when the internal pressure is the same as that of the atmosphere, it is necessary to provide a large number of protrusions on the labyrinth seal, so the axial length of the fourth labyrinth seal 84 is made large. There is a need. The greater the length of the fourth labyrinth seal 84 in the sea bream direction, the greater the amount of overhang of the shaft, so the length of the fourth labyrinth seal in the axial direction is related to the problem of shaft runout.

Therefore, it is necessary to make it as short as possible, but if it is made short, there is a risk of water leaking from the third outlet chamber 63.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional system, and the pressure around the cooling liquid lead-in/out port is made higher than the atmospheric pressure, and the fourth seal portion is located closer to the outside of the device. By allowing air to flow to the outlet chamber No. 3, simplifying the seal structure, and shortening the length of the seal in all axial directions, the amount of overhang of the rotating shaft can be reduced and the shaft runout can be reduced.

As a result, the gap between each seal and the supply pipe 4 can be set small, and the sealing effect of each seal can be increased.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 3, reference numeral 10 denotes a cover between a device installed between the rotating electric machine and the coolant lead-in/out device to flow current to the rotor coil, and this coolant lead-in/out device. This cover 10 also serves as a ventilation path for forced atmospheric cooling of the device (exciter) for flowing current to the rotor coil, and serves as the outer periphery of the third outlet chamber 63 of the coolant inlet/outlet device. The cooling gas flows through the labyrinth seal 8 so that the pressure becomes higher than atmospheric pressure.
4 and flows to the third outlet chamber side. The arrows in the figure indicate the direction of atmospheric flow.

Reference numeral 11 denotes a pipe connecting the cooling gas outlet of the third outlet chamber 63 and the outside of the cover 10.

By providing this lotus pipe 11, the air pressure on the outside of the cooling liquid introduction/input device becomes higher in the fourth labyrinth seal 84 part than in the third outlet chamber 63, so that the cooling gas flows into the third outlet chamber 63. It flows from the outside through the labyrinth seal 84 into the third outlet chamber 63 . Furthermore, since the pressure in the third outlet chamber remains at atmospheric pressure, the seal 83 between the second and third outlet chambers is not affected in any way. 84 is a fourth outlet seal in which the number of protrusions of the labyrinth seal is reduced by providing the through pipe 11.

As described above, according to the present invention, the cover is formed so that the pressure around the coolant inlet/output device is higher than atmospheric pressure, and the lotus pipe connecting the third outlet chamber and the outside of the cover is provided. Therefore, the length of the fourth labyrinth seal in all axial directions can be shortened.

In other words, the structure is simple and inexpensive.

If the length of the fourth labyrinth seal in the axial direction is short, the overhang amount of the shaft can be reduced, and the shaft runout can be significantly reduced.

Further, if the waviness is reduced, the radial gap between each seal and the supply pipe 9E can be reduced, and the sealing effect can be greatly enhanced. 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. 4, 612 is the outlet chamber 6 in FIG.
1 and 62 are integrated into an upstream outlet chamber, 712 is an outlet pipe that communicates with this upstream outlet chamber 612, and 9 is an air supply pipe similar to that shown in FIG. 1, which fills the upstream outlet chamber 612 with cooling liquid. By supplying gas from the air supply pipe 9 to maintain the pressure inside the upstream outlet chamber 612 at a value slightly higher than atmospheric pressure, contamination of the cooling liquid due to contact with the atmosphere is avoided. It is intended to prevent That is, the two outlet chambers 61 and 62 in FIG. 1 are combined into one,
The coolant discharged from the outlet pipe 712 is provided for recirculation as in FIG. 1. 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 was 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 secondary coolant lead-in/out device, FIG. 2 is a sectional view taken along the low U line in FIG. 1, and FIG. 3 is a coolant lead-in/out device according to an embodiment of the present invention. The figure is a diagram for explaining another example of application of the present invention. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is the inlet pipe, 2 is the inlet pipe, 2a is the closing part,
2b is an inflow path, 2c is a protruding piece, 3 is an outflow pipe, 3a is its closing part, 3b is an outflow path, 4 is a supply/discharge pipe, 4a is its flange, 5 is a rotor shaft, and 5a is its flange. , 5b is an inflow passage, 5c is an outflow passage, and 61 and 612 are upstream outlet chambers (
62 is a second outlet chamber, 63 is a downstream outlet chamber (third outlet chamber), 71, 72, 73, 712 are outlet pipes, 81, 82, 83, 84 are lapirin Seal, 9
10 indicates the air supply pipe, 10 indicates the cover, and 11 indicates the lotus tube. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A cylindrical supply/discharge pipe connected to the rotor shaft of a rotating electrical machine to introduce and lead out coolant to the rotor, and a coolant discharged from the supply/discharge pipe provided at intervals from the supply/discharge pipe. an upstream outlet chamber that receives the leakage cooling liquid from the upstream outlet chamber, a downstream outlet chamber adjacent to this upstream outlet chamber that receives leaked cooling liquid from the upstream outlet chamber, and a large area surrounding this downstream outlet chamber that cools the exciter of the rotating electric machine. A guide sheath that guides the cooling gas with a pressure higher than atmospheric pressure, and an exhaust that discharges the cooling gas that has leaked into the downstream outlet chamber from between the downstream outlet chamber and the supply/discharge pipe from the downstream outlet chamber to atmospheric pressure. A coolant lead-in/out device for a liquid-cooled rotor-type rotating electric machine having an outlet in the downstream outlet chamber.