JPS6038937B2 - 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, in order to improve the efficiency of power plant construction, it is increasingly necessary to increase the capacity of generators used in rotating electric machines, especially turbine generators. 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. It is not possible to increase the capacity. 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, in the case of a turbine generator, the rotor normally rotates at a speed of 3,600 revolutions per minute (60Hz).
The biggest problem in achieving this is how to introduce and extract coolant into a high-speed rotating body, 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 rotor that has been considered as a sub-chamber, and 1 is an inlet pipe to which coolant, such as pure water, is supplied via a feed pump (not shown). be.

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 outflow path for the coolant.

3a is an opening 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. It acts as a spacer to integrally connect the inflow pipe 2 and the outflow pipe 3, and also serves to reinforce both pipes 2 and 3. This protruding piece 2c
The inflow pipe 2 and the outflow pipe 3 are firmly connected together by, for example, brazing, and form a supply/discharge pipe 4. 4a is a flange formed at the terminal end of the supply pipe 4; 5 is a rotor shaft of a rotating electric machine having a flange 5a that is in close contact with this flange and connected, for example, with a bolt (not shown);
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 passage 5b and an outflow passage 5c which communicate with the inflow passage 2b and the outflow passage 3b of the supply/discharge pipe 4, respectively. The collected coolant circulates through the rotor coil and then is discharged into the outflow passage 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 30. . 61' This is the first outlet chamber for receiving the discharged liquid from the Mako Sekiguchi 3a, and is always filled with the cooling liquid to prevent the cooling liquid (pure water) 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.
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. The inlet pipe 11 is again fed via a feed pump (not shown),
Subject to recirculation.

Reference numeral 81 designates a first labyrinth seal for preventing the cooling liquid from leaking from inside the inlet pipe 1 to the first outlet chamber 61, and it is possible to completely eliminate moat liquid between the rotating part and the fixed part. Since this is impossible, efforts are made exclusively 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 be poor, so it goes without saying that it is preferable to have a small amount. . 82 is a second labyrinth seal for suppressing 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 the second labyrinth seal. 2nd to accept leakage
This is the exit chamber of

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, and by constantly supplying gas such as nitrogen and hydrogen to the second outlet chamber 62 through this air supply pipe, the second outlet chamber 62 is heated. 62 is always kept slightly higher than atmospheric pressure to prevent atmospheric air from entering the second outlet chamber).

Therefore, the moat liquid in the second outlet chamber 62 does not come into contact with the atmosphere and is contaminated, and the coolant drawn out from the second outlet pipe 72 is the same as the coolant drawn out from the first outlet chamber 61. Similarly, it is provided for 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. 3rd place to accept leakage
outlet chamber, 73 is a third outlet pipe adapted 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. The above device can achieve the intended purpose.

Incidentally, 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 there is an overhang on the rotor shaft 5. It will be supported in form. For this reason, it is always exposed to the problem of axial runout of the feeding E pipe 4. Axial runout is undesirable because it impairs the sealing effect. This shaft vibration is caused by the supply/discharge pipe 4
The longer this occurs, the more likely it is to occur, so it is better to keep it short, but in the above-mentioned follower device, there are three outlet chambers, and the feed pipe 4 has to be made that much longer, increasing the risk of shaft runout. become. Furthermore, in the conventional device described above, the exit chamber 61
Since the outlet chamber 61 is kept full of water, the casing of the outlet chamber 61 must be tightly sealed, and since the outlet chamber 61 is full of water, the power loss due to friction between the water and the supply/discharge pipe 4 is large. In order to solve this problem, it is conceivable to have two outlet chambers as shown in FIG. 3 and not to fill either outlet chamber with water. That is, in Figure 3, 6
12 is an exit chamber formed by integrating the exit chambers 61 and 62 in FIG. 1, and 712 is an exit pipe passed through this exit chamber, and the rest is the same as in FIG. 1.The concept of this FIG. 3 is as follows. , the outlet chamber 612 is not filled with water, and therefore, in order to avoid contact with the atmosphere, a gas such as nitrogen or hydrogen is supplied from the air supply pipe 9 to the outlet chamber 612, and the pressure in the outlet chamber 612 is lowered from atmospheric pressure. The idea is to keep the value high to prevent air from entering. 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. According to FIG. 3, the drawbacks of FIG. 1 can be avoided to some extent, but the following major problems remain. That problem is cavitation. That is, the entrance part 3 of the outflow pipe 3
Since the pressure in the outlet chamber 612 that receives the drained liquid from a is not as high as when it is full of water, the coolant is discharged without resistance).
(not shown) is lower than when the outlet chamber 612 is full. The temperature of the coolant flowing through the coolant pipes such as the outflow passages 3b and 5c and the rotor coil increases due to the cooling of the rotor coil, and when the pressure of the coolant decreases, cavitation easily occurs. Eating parts quickly is promoted. In FIG. 1, the outlet chamber 61 that receives the drained liquid from the outflow pipe 3 is kept full of water in order to prevent such cavitation. Therefore, conventionally, keeping the outlet chamber full of water is an indispensable condition. Therefore, the various difficulties mentioned above were thought to be unavoidable. Now, by further developing the concept shown in FIG. 3 above, the device shown in FIG. 4 can be considered as a coolant lead-in/out device that can solve not only the various problems shown in FIG. 1 but also the problem of cavitation.

In FIG. 4, there is shown a discharge IJ having a hole 10a, which is fixed to the inlet pipe by, for example, a competitive fit so that the hole 10a faces the entrance 3a. Therefore, the cooling liquid from the outflow pipe 3 is transferred to the hole 1 of the discharge ring 10.
It will be discharged into the outlet chamber 612 via Oa. That is, the discharge ring 10 exhibits a so-called orifice action when discharging the coolant, and the pressure in the entrance portion 3a becomes higher than the pressure in the outlet chamber 612. For this reason, it is possible to reliably prevent cavitation, which became a problem in FIG. Having solved the problem of cavitation, it is no longer necessary to keep the outlet chamber 612 full of water, thus making it possible to reduce the number of outlet chambers to two. Therefore, the length of the supply/discharge pipe 4 can be made shorter than that shown in Fig. 1, which reduces the risk of wobbling, and since it is not filled with water, it is easier to seal the casing of the outlet chamber 612. It is possible to obtain a coolant introducing/extracting device that can eliminate power loss due to friction with the exhaust pipe 4. However, in the above-mentioned secondary coolant inlet/output device, the coolant circulates and cools the rotor coil, and then passes through the opening 3a of the outlet pipe 3 via the outlet passages 5c and 3b, and then passes through the hole 10a of the discharge ring. It is discharged into the outlet chamber 612 in the form of a jet.

The discharged coolant has a velocity that is a vector combination of the jetting velocity from the small hole 10a of the discharge ring 10 and the circumferential velocity of the outer periphery of the supply/discharge pipe 4. In this way, the coolant was discharged at a considerable speed and collided with the inner wall of the outlet chamber 612, making the collision sound very loud. Furthermore, the inner wall of the outlet chamber 612 may become eroded due to the collision of the coolant over many years of use. Furthermore, the sealing performance of the outlet chamber 612 was also deteriorated. This invention was made in view of the above-mentioned drawbacks, and the present invention is designed to provide cooling liquid that surrounds the discharge section of the supply pipe and is discharged from the discharge section between the discharge section of the supply 8E pipe and the outlet chamber. A storage member is provided to hold the cooling liquid in a full state and to have an outlet chamber and a suitable discharge path between the supply and drain pipes, and the cooling liquid held in a full state in the storage part is transferred to the outside. A liquid cooling system that achieves high reliability by forming an outlet passage leading to the housing member, and providing a restriction member in the outlet chamber and the outlet passage that limits the amount of coolant discharged from the outlet passage. The present invention provides a coolant inlet/output device for a rotor-type rotating electric machine.

Hereinafter, one embodiment of the present invention will be described based on FIG. 5.

The figure shows an enlarged view of the main part of the coolant discharge part, and as is clear from FIG. 5, the discharge ring 10 is not used and the end of the outflow pipe 3 is extended to the position of the discharge ring 10. The discharge hole 3 corresponds to the small hole 10a of the discharge ring 10.
c is provided. That is, by adopting such a structure, the release ring 10 can be omitted. Reference numeral 11 denotes an appropriate support member (
This is an annular housing member that is supported on the inner wall surface of the outlet chamber 612 via a hole (not shown), and one end 11 of this housing member 11.
A predetermined gap G is provided between the inner circumferential surface of a and the outer circumferential surface of the outflow pipe 3, and between the inner circumferential surface of the other end portion 11b of the housing member 11.
is provided, and this gap G forms a discharge path that communicates with the outlet chamber 612, from which a part of the cooling liquid held in the storage section 11 in a full state is discharged to the outlet chamber 612. .

Reference numeral 12 denotes a lead-out path consisting of a plurality of pipes formed around the circumference within the wall of the housing member 11, so that the cooling liquid in the housing member 11 flows out from the side toward the supply/discharge pipe 4 side. It is bent at almost a right angle.

In this way, the coolant flowing out from the outlet path 12 is made to collide with the coolant discharged from the gap G.
Reference numeral 13 denotes a restricting member disposed in the discharge passage to limit the amount of coolant discharged from the discharge passage. The case is shown below.

In this invention configured as described above, the outflow pipe 3
After keeping the cooling liquid discharged from the discharge hole 3c in the storage member 11 in a full state, a part of the cooling liquid in the storage member 11 is drained from the discharge path in the gap G between the storage member 11 and the outflow pipe 3. 13 and is discharged into an outlet chamber 612. On the other hand, the cooling liquid in the housing member 11 also flows from the outlet path 12 formed in the housing part village 11 to the supply/discharge pipe 4 side.
That is, it is led out toward the outflow pipe 3 side. The cooling liquid discharged from the discharge hole 3c of the outflow pipe 3 is held in the accommodating member 11 in a submerged state, and the accommodating member 1
A part of the cooling liquid in the gap G is discharged from the outlet chamber 612 through the discharge path of the gap G.
However, since the amount of coolant discharged is limited by the null seal 13, the discharge rate is extremely low. Furthermore, by adjusting the threaded seal 13, the coolant discharged from the outlet path 12 located at the lower side of the supply/discharge pipe 4 can be made to reach the supply/discharge pipe 4. That is, the cooling liquid in the housing member 11 is discharged to the outlet chamber 612 due to the effect of the screw seal 13.
Although the amount of discharge from the outlet passage 12 formed in 1 is larger than the amount of discharge from the gap G, since the outflow velocity from the outlet passage 12 does not include a rotational speed component, the outlet chamber 612
This has the effect of reducing the collision speed of the coolant against the inner circumferential wall of the cooling liquid. In addition, the coolant discharged from the discharge passage to the outlet chamber 612 while being restricted by the screw seal 13 is slightly affected by centrifugal force due to the rotation of the supply/discharge pipe 4 and scatters toward the inner circumferential wall of the outlet chamber 612. The liquid flows from the outlet passage 12 to the outlet chamber 6.
By colliding with the cooling liquid led out to the outlet chamber 612, the scattering speed of the discharged liquid to the inner circumferential wall of the outlet chamber 612 is significantly reduced. Therefore, the sound of the coolant colliding with the inner circumferential wall of the outlet chamber 612 can be significantly reduced, and the sound of the coolant colliding with the outlet chamber 612 can be almost completely eliminated. Furthermore, the sealing performance of the outlet chamber 612 is not deteriorated, and the inner circumferential wall of the outlet chamber 612 is also prevented from being corroded. Note that the gap G is set in consideration of the axial runout of the supply/discharge pipe 4. Further, the dimensions, shape, number, etc. of the lead-out passages 12 are set so that the inside of the housing member 11 can be maintained in a water-filled state and the pressure inside the housing member 11 is set to a value that does not cause cavitation. Further, the direction of the screw seal 13 is set in such a direction as to have a pumping effect such that the coolant discharged from the gap G into the outlet chamber 612 is sent into the housing member 11. Note that the reason why the discharge hole 3c of the outflow pipe 3 is larger than the small hole 10a of the discharge ring 10 in FIG. Since the housing member 11 is maintained in this state, it has the effect of preventing cavitation by setting the dimensions, shape, number, etc. of the outlet passage 12 described above, and the discharge hole 3c of the outflow pipe 3 does not necessarily have to be a small hole. This is because things have gotten better.

As the discharge hole 3c becomes larger, the distance of water passing through the discharge hole 3c becomes lower, and corrosion of the discharge hole 3c is reduced. Also,
As is clear from FIG. 5, the discharge hole 3c of the outflow pipe 3 is shown as having one large hole, but the discharge hole 3c of the outflow pipe 3 may be provided with a plurality of small holes. Needless to say. Further, from the above, as shown in FIG. 6, the cooling liquid from the outflow path 3b of the outflow pipe 3 may be discharged from the entrance part 3a of the outflow pipe to the housing member 11, which is similar to the above embodiment. be effective.

That is, in this case, the dimensions, shape, and number of the lead-out passages 12 must be set so that the pressure within the housing member 11 will not cause cavitation. Furthermore, in the above embodiment, a case has been described in which the limiting member 13 made of a screw seal is provided on the supply/discharge pipe 4, that is, the outflow pipe 3, or the outflow pipe 3 and the inflow pipe 2. It may also be provided.

Further, in the above embodiment, the case where the limiting member 13 is made of a screw seal is described, but the limiting member 13 is not limited to this, and may be made of a labyrinth seal or the like.

Further, in the above embodiment, a case is shown in which pure water is used as the cooling liquid, but it goes without saying that a liquid other than pure water may be used as long as it does not corrode each tube 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 if necessary, it can be applied to other generators such as a water turbine generator, as well as various secondary generators such as an electric motor.
Needless to say, it can be applied to the exit chamber of

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.

As explained above, this invention maintains the cooling liquid discharged from the discharge part of the supply pipe in a full state in the housing member, and part of the cooling liquid is discharged between the housing member and the supply/discharge pipe. The cooling liquid is discharged into the outlet chamber by being restricted by the restriction member, and collides with the flow toward the supply pipe from the outlet formed in the storage area, which significantly reduces the collision noise of the coolant. In addition to making noise, the corrosion resistance and sealing performance of the outlet chamber can be significantly improved, and a highly reliable coolant lead-in/out device can be obtained.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a conventional liquid-cooled rotor-type rotating electric machine coolant inlet/output device, Fig. 2 is a cross-sectional view taken along the Rolo line in Fig. 1, and Fig. 3 is a derivation considered before reaching this invention. FIG. 4 is a diagram showing a lead-in/out device developed from FIG. 3 and considered before reaching this invention. FIG. FIG. 6 is an enlarged view of a main part of a coolant lead-in/out device for an electric machine, and is a diagram for explaining another example of application of the present invention. Note that the same reference numerals in each figure indicate the same or equivalent parts, 4 is a supply/discharge pipe, 612 is an outlet chamber, 11 is a housing member,
12 is a lead-out path, and 13 is a limiting member. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A supply/discharge pipe coaxially connected to the rotor shaft; an outlet chamber provided surrounding the supply/discharge pipe to receive the coolant discharged from the supply/discharge pipe; and an inner wall of the outlet chamber. an annular housing member supported and arranged concentrically with the supply/discharge pipe with a gap therebetween; and a circular housing member formed within the wall of the housing member and discharged into the housing member from a discharge hole of the supply/discharge pipe. A plurality of lead-out passages for causing the discharged coolant to flow out toward the supply/discharge pipe in the outlet chamber, and a discharge passage formed in the longitudinal direction of the outer circumference of the supply/discharge pipe by the gap are arranged to limit the discharge amount. A cooling liquid lead-in/out device for a liquid-cooled rotor-type rotating electric machine, comprising: a limiting member; 2. A cooling liquid lead-in/out device for a liquid-cooled rotor-type rotating electric machine according to claim 1, wherein the limiting member is provided in a supply/discharge pipe. 3. A coolant lead-in/out device for a liquid-cooled rotor-type rotating electric machine according to claim 1 or 2, wherein the limiting member is a screw seal. 4. A coolant lead-in/out device for a liquid-cooled rotor-type rotating electric machine according to claim 1 or 2, wherein the limiting member is a labyrinth seal.