JPS6038935B2 - 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 single rotary electric machine, it is necessary to determine how to suppress the 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 circulate the stator coolant to cool it, but if this can be developed and the coolant can be successfully circulated to the rotor, The cooling effect can be dramatically increased. However, if we take a turbine generator as an example, the rotor normally 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. This is the biggest problem in realizing Kazu, 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 a diagram in which a coolant such as pure water is supplied in the direction of arrow A via a feed pump (not shown). This is the inlet pipe. The reason why pure water is used as a cooling liquid is as follows. Since the coolant is circulated within each tube and rotor coil as described below, if water containing impurities is used as the coolant, the impurities may cause the circulation of each tube and rotor coil. Therefore, it is desirable to use pure water that does not contain any impurities. Reference numeral 2 denotes a circular inflow pipe which has a closed part 2a and receives the coolant from the inlet pipe 1 through this closed part, 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.

3 is an opening provided at one end of the outflow pipe 3, and the cooling liquid is discharged through this opening.

By the way, the outflow pipe 3 and the inflow pipe 2 are integrally connected as shown in FIG. 2 to form a supply pipe E pipe 4.

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 base for integrally connecting the inflow pipe 2 and the outflow pipe 3, and also serves as reinforcement for the exchangers 2 and 3. This protruding piece 2c
The inlet pipe 2 and the outlet pipe 3 having the same diameter are firmly connected together, for example, by a competitive fit, and form a supply/discharge pipe 4. Reference numeral 4a indicates a flange formed at the end of this E-feeding pipe 4, and 5 indicates a rotor shaft of a rotating electrical machine having a flange 5a that is in close contact with this flange and is connected to the flange by, for example, a bolt (not shown). Needless to say, a rotor coil (not shown) is attached to the 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 self-feeding tube 4, respectively, and 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 coolant, and after the rotor coil is circulated and cooled as described above, it is discharged from the entrance 3a of the outflow pipe 3 via the outflow channels 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
and the rotating feed pipe E pipe 4 to prevent leakage.
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, 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 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). Reference numeral 83 indicates a third labyrinth seal for suppressing leakage between the second outlet chamber 62 and the rotating brood feeder tube 4, and reference numeral 63 indicates a third labyrinth seal for suppressing leakage between the second outlet chamber 62 and the rotating chick feeding tube 4. 3rd place to accept leakage
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 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, the supply/discharge pipe 4 is always
The problem of shaft runout has been raised. Axial runout is undesirable because it impairs the sealing effect. This shaft runout is more likely to occur as the supply/discharge pipe 4 is longer, so it is better to keep it short, but in the conventional device described above, there are three outlet chambers, and the supply/discharge pipe 4 has to be made that long. This will increase the risk of swing. Furthermore, in the conventional device described above, the outlet chamber 61 is kept full of water, so the casing of the outlet chamber 61 must be tightly sealed, and since it is a submersible device, there is no power loss due to friction between the water and the supply SE pipe 4. The problem was that it was 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
Reference numeral 12 designates an exit chamber formed by integrating the exit chambers 61 and 62 in FIG. 1, and 712 designates an exit pipe that is passed through the exit chamber, and the rest is the same as in FIG. 1. The idea behind this figure 3 is
In order to avoid filling the outlet chamber 612 with water and therefore 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 to lower the pressure inside the outlet chamber 612 below 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 opening of the outflow pipe 3 □
Since the pressure in the outlet chamber 612 that receives the BE liquid from the section 3a is not as high as when the water is full, the coolant is discharged without resistance). ) etc., the pressure in the coolant pipes is the outlet chamber 612.
is lower than when the water is full. The temperature of the coolant flowing through the coolant pipes such as the outflow passages 3b and 5c and the rotor coil is as follows:
Since the rotor coil rises due to cooling, cavitation easily occurs when the pressure becomes low, leading to erosion of surrounding members. In FIG. 1, the outlet chamber 61 that receives the discharged liquid from the outflow pipe 3 is maintained in a submerged state in order to prevent such cavitation. Therefore, it has conventionally been considered that it is an essential condition to keep the outlet chamber full of water, and for this reason, the various problems described above have been considered 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, reference numeral 10 denotes a discharge ring having a small hole 10a, which is fixed to the inlet pipe by, for example, a competitive fit so that the hole 10a faces the entrance portion 3a. Therefore, the cooling liquid from the outflow pipe 3 is transferred to the hole 10 of the discharge ring 10.
It will be discharged to the outlet chamber 612 via a. That is, when the discharge ring 10 discharges the coolant, the pressure at the entrance portion 3a becomes higher than the pressure at the outlet chamber 612 due to a so-called orifice action. Therefore, it is possible to reliably prevent cavitation, which became a problem in FIG. 3. By eliminating the cavitation problem, it is no longer necessary to keep the outlet chamber 612 full of water, and it is therefore 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 shaft vibration.Also, 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 conventional coolant lead-in/out device, the coolant circulates and cools the rotor coil, and then is injected from the small hole 10a of the discharge ring 10 through the outlet 3a of the outlet pipe 3 via the outlet passages 5c and 3b. is discharged into the outlet chamber 612.

The discharged coolant has a velocity that is a vector combination of the jetting velocity from the holes 10a of the discharge ring 10 and the circumferential velocity of the outer periphery of the supply/discharge pipe 4. In this manner, the coolant was discharged at a considerable speed and collided with the inner circumferential wall of the outlet chamber 612, making the collision sound extremely loud. Moreover, the inner circumferential wall of the outlet chamber 612 may become corroded 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 has been made in view of the above-mentioned drawbacks, and is designed to provide cooling liquid that flows through the discharge section of the supply/discharge pipe and is discharged from the discharge section between the discharge section of the supply/discharge pipe and the outlet chamber. A cooling liquid outlet for a liquid-cooled rotor-type rotating electric machine that achieves high reliability by maintaining the housing in a full liquid state and arranging a housing member between it and the supply pipe so as to have an outlet chamber and a fitting discharge passage. It provides an input device.

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 11 is an annular housing member with an open inner circumferential surface (hereinafter referred to as an annular member).
The outlet chamber 61 is surrounded by a small hole 10a, which is the coolant discharge part of the supply/discharge pipe 4, through an appropriate support member (not shown).
2 is attached to the inner wall surface and stores the cooling liquid discharged from the small hole 10a in a full state. One end 1 of this annular member 11
1a and the outer circumferential surface of the discharge ring 10, and between the inner circumferential surface of the pond end 11b of the annular member 11 and the outer circumferential surface of the outflow pipe 3, a predetermined gap G is provided, respectively. Gap G
forms a discharge path that communicates with the outlet chamber 612, and from this discharge path, the cooling liquid kept in the annular member 11 full of water flows into the outlet chamber 6.
It is designed to be discharged on the 12th. 11c is a small hole for removing air bubbles.

In the present invention configured as described above, the cooling liquid discharged from the small holes 10a of the discharge ring 10 is transferred to the annular member 1.
After the cooling liquid in the annular member 11 is kept full of water, the cooling liquid in the annular member 11 is discharged to an outlet chamber 612 from a discharge path in a gap G between the annular member 11, the discharge ring 10, and the outflow pipe 3. .

The coolant discharged from the small hole 10a of the discharge ring 10 is kept in the annular member 11 in a full state, and the coolant in the annular member 11 is passed from the discharge path in the gap G to the outlet chamber 612.
However, the discharge speed can be made extremely low by selecting the gap G. In addition, the coolant discharged from this discharge passage receives some centrifugal force due to the rotation of the supply E pipe 4 and scatters toward the inner circumferential wall of the outlet chamber 612; The collision force of the cooling liquid is also extremely low, the collision noise caused by the collision of the coolant is also extremely low, there is no deterioration in sealing performance, and the exit chamber 6
It is also possible to prevent the inner peripheral wall of No. 12 from being eroded. The gap G is set so that the inside of the housing member 11 can be kept full of water and with consideration given to the wobbling of the supply/discharge pipe 4. In the above embodiment, the small hole 1 provided in the release ring 10
0a are arranged in two rows in the circumferential direction, but they may be arranged in one row or three or more rows.

Further, although the discharge ring 1 is fixed to the inflow pipe 2 by competitive fit, it may be fixed by other means, or conversely, it may be fixed to the outflow pipe 3. Further, in the above-mentioned outflow pipe, the release ring 10 and the outflow pipe 3 are separate bodies, but they can also be formed integrally. Furthermore, according to the present invention, the annular member 11 is kept full of the coolant discharged from the holes 10a of the discharge ring 10, so that the annular member 11 has the effect of preventing cavitation. Therefore, the discharge hole of the supply pipe 4 can be made somewhat larger.

Since the discharge hole is enlarged, the speed of water passing through the discharge hole is reduced, and corrosion of the discharge hole is reduced. Also, from this, if the housing member 11 is provided with a cavitation prevention effect, the cooling liquid from the outlet passage 3b of the outlet pipe 3 can be transferred to the closed part 3a of the outlet pipe 3 without using the discharge ring 10, as shown in FIG. Alternatively, the liquid may be discharged from the storage member 11 to the storage member 11, and the same effect as in the above embodiment can be obtained. That is, in this case, it is necessary to set the gap G so that the pressure within the housing member 11 has a value that does not cause cavitation. Further, in the above embodiment, the case where the housing member 11 is annular is described, but it may be square. 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 any 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 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.

As explained above, the present invention maintains the cooling liquid discharged from the discharge part of the chick supply pipe in a full state in the storage part, and directs the cooling liquid to the outlet from the discharge path between the storage member and the supply/drainage pipe. Since the cooling liquid is discharged into the chamber, the collision sound of the coolant can be significantly reduced, and the corrosion resistance and sealing performance of the exit chamber can be significantly improved, thereby providing a highly reliable coolant inlet/output device. I can do it.

[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 showing a coolant lead-in/out device for an electric machine, and is a view of one embodiment 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,
G is the gap. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A coolant supply/discharge pipe coaxially and directly connected to the rotor shaft;
an outlet chamber that is provided surrounding the discharge part of the supply/discharge pipe and receives the cooling liquid from the discharge part; and an outlet chamber that has an annular shape with an open inner circumferential surface and is disposed in the outlet chamber surrounding the discharge part. , a storage member that accommodates and holds the cooling water discharged from the discharge part in a full liquid state, and a discharge path formed by a gap between the supply/discharge pipe and an inner circumferential end of the storage member. A coolant inlet/output device for liquid-cooled rotor-type rotating electric machines.