JPS6038938B2 - 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, increasing the capacity of a rotating electric machine depends on 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 electric 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), and it is difficult to introduce coolant into such a high-speed rotating body and how to extract it. The biggest problem in achieving this goal is how to achieve this goal, 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). .

2 has an opening 2a, and the inlet pipe 1 is connected to the inlet pipe 1 through this entrance.
It is a circular inflow pipe that receives the coolant from the inside, and its hollow interior 2b serves as an inflow path for the coolant.

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 a closing part provided at one end of this outflow pipe 3;
Coolant is discharged through this closure.

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. This serves as a base for integrally connecting the inflow pipe 2 and the outflow pipe 3, and also serves as reinforcement for both pipes 2 and 3. The inflow pipe 2 and the outflow pipe 3 having the protruding piece 2c are firmly connected together by, for example, solid fit, and constitute a supply/discharge pipe 4. 4a is a flange formed at the end of this supply pipe 4, and 5 is a flange 5a 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 pipe 5b and an outflow pipe 5c that communicate with the inflow path 2b and the outflow path 3b of the scale feed pipe 4, respectively, and the flow is carried out from the inflow path 5b. 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 fluid, and after the rotor coil is circulated and cooled as described above, it is discharged from the opening 3a of the outflow pipe 3 via the outflow passages 5c and 3b. Ru. Reference numeral 61 designates an upstream outlet chamber, that is, a first outlet chamber, for receiving the discharged liquid from the entrance portion 3a, and is always filled with the cooling liquid to prevent the cooling liquid from coming into contact with the atmosphere and being contaminated. It is configured to keep

71 is a first outlet chamber for discharging the cooling liquid from this first outlet chamber.
The coolant drawn out from this first outlet pipe does not come into contact with the atmosphere and is not contaminated as described above, so after lowering the temperature using a heat exchanger (not shown), etc. 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 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 desirable to have a small amount. do not have. 82 is a third labyrinth seal for suppressing the amount of leakage between the first outlet chamber 61 and the rotating supply/discharge pipe 4, and 62 is a seal from the first outlet chamber 61 that has passed through this second labyrinth seal. an intermediate outlet chamber or a second outlet chamber for receiving leakage of the liquid;

Unlike the first outlet chamber 61, this second outlet chamber 62 is not filled with cooling liquid, and therefore there is a risk that the cooling liquid will come into contact with the atmosphere and become contaminated. Reference numeral 9 denotes an air supply pipe for preventing this, and 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/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 that reaches the third outlet chamber 63 has three stages of seals 82,
Due to the effect of
Therefore, the coolant discharged 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. Although the above-described arrangement allows the coolant to be recirculated in a closed loop after being discharged from the rotor, it is possible that air or other gases may become entrained in the coolant and be carried into the rotor.

Of course, water is heavier than gas and therefore has a large centrifugal force, so when some of the gas mixed with the cooling water and transported enters the inlet passage 2b, it is pushed toward the center of the rotor shaft 5 and accumulates near the center of the shaft, increasing its amount. If it does, it becomes a large bubble and flows into the rotor coil together with the cooling liquid.

This is extremely inconvenient because it narrows the waterway area of the inflow passage 2b and causes the flow of water to become unstable, and at the same time generates vibrations due to unbalanced weight of the rotor. This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the axis of the inlet passage 2b and the outlet passage 3
By providing a small discharge pipe connecting the inflow channel 2b, the gas accumulated in the axis of the inflow channel 2b can be discharged through the discharge pipe to the outflow channel 3b, thereby securing the waterway area of the inflow channel and obtaining a stable flow of water. Furthermore, air bubbles do not flow into the rotor coil, and vibration of the rotor due to air bubble inflow can be prevented.

Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 3 to 5, reference numeral 10 denotes a small discharge pipe provided in the radial direction inside the inflow pipe 2 with both ends fixed to the pipe wall of the inflow pipe 2 by means such as welding or craftsmanship, and the central part of the discharge pipe 10 is A gas discharge passage 10b is formed at both ends of which are connected to an outflow passage 3b formed by a gap between the outflow pipe 3 and the inflow pipe 2, and a gas discharge passage 10b is formed at approximately the center of the inflow pipe 2 of the discharge pipe 10. ,
A discharge row oa is formed, one end of which is closed to the inflow passage 2b of the inflow pipe 2, and the other end of which is closed to the gas discharge passage 10b. With this configuration, the discharge pipe 10, that is, the gas 9E
The fluid in the outlet passage 10b is pulled by the flow of the coolant in the outlet passage 3b and flows out into the outlet passage 3b due to the pumping action and the pressure of the coolant flowing in the inlet passage 2b. Due to the pressure difference between the pressure of the cooling liquid in the outflow path 3b and the pressure of the coolant in the outflow path 3b, which has decreased due to the resistance generated during outflow and rotor coil cooling, the gas discharge path 1 is discharged from the exhaust port 10a.
A small amount of cooling liquid flows into the outflow passage 3b through 0b approximately 2b.
It flows from near the center of , that is, near the discharge row OA.

As mentioned above, since the gas mixed in the coolant is pushed toward the center of the rotary shaft 5, this gas passes through the outlet 10a and the gas discharge path 10b, and is discharged together with a small amount of the coolant into the inflow path 2b. Become.

In addition, in the above example, the discharge pipe was a round pipe, but
It may also be streamlined as shown in FIGS. 6, 7, and 8.

This is to prevent the flow of cooling water from being disturbed. Further, the discharge port 10a is preferably provided in the opposite direction to the flow of the coolant, as shown in FIGS. 3 and 6.

This is to reduce the amount of coolant flowing out from the inflow path 2b to the outflow path 3b due to the pressure of the flow of the coolant. Further, in the above embodiment, one exhaust pipe and two inlet pipes are provided to the full length, but the length may be half as long as shown in FIG. 9.

Note that a plurality of these discharge pipes 10 may be provided. That is,
If necessary, the exhaust pipe can be installed in a part where gas mixed in the coolant tends to accumulate.If there are many parts where gas mixed in the coolant tends to accumulate, it can be installed in multiple locations along the axis, depending on the location.
The installation direction does not necessarily have to be the same direction. Further, 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. .

As described above, according to the present invention, since the discharge pipe is provided that connects the axis of the inflow and the outflow, it is possible to secure the waterway area of the inflow and obtain a stable flow of coolant, while at the same time It is possible to prevent air bubbles from flowing into the coil and to prevent vibrations of the rotor due to air bubbles flowing into the coil.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional coolant lead-in/out device, FIG. 2 is a sectional view taken along the Rolo line in FIG. 1, FIG. The figure is W in Figure 3.
5 is a sectional view taken along the line V-V in FIG. 4, FIG. The figures are a sectional view taken along the blood-skin line in FIG. 6, FIG. 8 is a sectional view taken along the field line in FIG. 7, and FIG. 9 is a diagram showing another embodiment of the present invention. Note that the same symbols in each figure indicate the same or corresponding parts, 1 is the inlet pipe, 2 is the inflow pipe, 2a is the opening thereof,
2b is an inflow channel, 2c is a projecting piece, 3 is an outflow pipe, 3a is an opening thereof, 3b is an outflow channel, 4 is a supply/discharge pipe, 4a is a flange thereof, 5 is a rotor pulp, and 5a is a flange thereof. , 5b is an inflow channel, 5c is an outflow channel, 61 is an upstream outlet chamber (first outlet chamber), 62 is an intermediate outlet chamber (second outlet chamber), 63 is a downstream outlet chamber (third outlet chamber). ), 71, 72, 73 are outlet pipes, 81, 82, 83, 84 are labyrinth seals, 9 is an air supply pipe, 1 river is a discharge pipe, 10a is a discharge port, and 10b is a gas discharge path. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Scope of Claims] 1. A circular inlet pipe having one end connected to a rotor shaft of a rotating electrical machine and having an open end to introduce cooling liquid into the rotor shaft;
an outflow pipe disposed with a gap around the outer periphery of the inflow pipe, one end of which is connected to the rotor shaft and an opening at the other end for leading out the coolant discharged from the rotor shaft through the gap; an upstream outlet chamber provided with a gap around the outer periphery of the outflow pipe and filled with a shielding gas having a pressure higher than atmospheric pressure that receives the discharged cooling liquid from the opening of the outflow pipe and discharges it to the outside; a downstream outlet chamber provided in the axial direction of the outlet chamber to receive leaked cooling liquid from the upstream outlet chamber;
A discharge pipe is provided inside the inflow pipe in the radial direction thereof, and the hollow hole is provided with a discharge pipe that opens into an outflow path consisting of a central portion of the inflow pipe and a gap between the inflow pipe and the outflow pipe. Coolant inlet/output device for liquid-cooled rotor-type rotating electric machines. 2 Cooling fluid lead-in/out of a liquid-cooled rotor-type rotating electrical machine according to claim 1, characterized in that the opening on the central side of the inflow pipe of the discharge pipe is provided on the downstream side of the inflowing cooling fluid. Device. 3. A coolant lead-in/out device for a liquid-cooled rotor-type rotating electric machine according to claim 1, wherein the discharge pipe has a streamlined cross section.