JPS6038936B2 - 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 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 coolant through the stator to cool it, but if we can develop this and successfully circulate the coolant all the way 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 (60Hz), and the question of how to introduce and extract the coolant into such a high-speed rotating body is a major challenge to achieve this goal. This problem has hindered the spread of liquid rotor type rotating electric machines.

FIG. 1 is a diagram showing a conventionally considered coolant inlet/output device for a liquid 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 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 a closing part provided at one end of this outflow pipe 3;
Coolant 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 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. The inflow pipe 2
It connects the outflow pipe 3 and the outflow pipe 3 together, and also serves to reinforce both the pipes 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 solid fit or the like, and constitute a supply/discharge pipe 4. 4a is a flange formed at the end of this supply/discharge 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 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 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. . 61 is this opening □
This is the first outlet chamber for receiving the discharged liquid from the section 3a, and is configured to always remain full of the cooling liquid to prevent the cooling liquid (pure water) from coming into contact with the atmosphere and being contaminated. ing.

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 moat liquid is circulated again through the first outlet pipe 71 as described above, so it is not a big problem, but if the leakage amount is too large, the efficiency will be poor, so it is preferable to have a small amount. Needless to say. 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, 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. The third outlet chamber, 73, receiving the liquid is a third outlet pipe connected to this third outlet chamber.

The cooling liquid reaching the third outlet chamber 63 is transported through two-stage seals 82 and 8.
Due to the effect of No. 3, since it is a small amount, it is not exposed to the atmosphere, and therefore the coolant drawn out from the third outlet pipe 73 is discarded as 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. 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 feed 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 axial runout of the feed 8F pipe 4 is always a problem. Axial runout is undesirable because it impairs the sealing effect. This shaft runout is caused by the feed pipe 4.
The longer this occurs, the more likely it is to occur, so a shorter length is better, but the conventional device described above has three outlet chambers, which necessitates making the supply/discharge pipe 4 that much longer, which increases the risk of shaft vibration. Become. Furthermore, in the conventional device described above, the exit chamber 61
Since the casing of the outlet chamber 61 must be kept tightly sealed, there is a problem in that there is a large power loss due to friction between the water and the chick feeding pipe 4 because the casing is full of water. 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 denotes an outlet chamber formed by integrating the outlet chambers 61 and 62 in FIG. 1, and 712 denotes an outlet pipe that is passed through the outlet 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 to the outlet chamber 612 from the air supply pipe 9 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. The problem is cavitation. In other words, the pressure in the outlet chamber 612 that receives the pseudo liquid from the closed part 3a of the outflow pipe 3 is not as high as when it is full of water, so the coolant is discharged without resistance). The pressure in the coolant tubes, such as the child coil (not shown), is lower than when the outlet chamber 612 is full of water. The temperature of the coolant flowing through the outflow passages 3b and 5c and the coolant pipes such as the rotor coil increases as a result of cooling the rotor coil, and when the pressure decreases, cavitation easily occurs and the surrounding area It ends up eating away at the wall. In FIG. 1, the purpose of keeping the outlet chamber 61 that receives the discharged liquid from the outflow pipe 3 in a full water state is to prevent the occurrence of such cavitation. was considered to be an indispensable condition, and for this reason, the various difficulties mentioned above were considered 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, reference numeral 10 denotes a discharge ring having a small hole 10a, which is fixed to the inflow pipe by, for example, a tight fit so that the small hole 10a faces the opening 3a. Therefore, the cooling liquid from the outlet pipe 3 is discharged into the outlet chamber 612 through the hole 10a of the discharge ring 10. That is, the discharge ring 10 exhibits a so-called orifice action when discharging the coolant, and the pressure in the closed 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. By solving the problem of cavitation, it is no longer necessary to use the exit chamber 6.
12 does not have to be kept full of water, thus a reduction of the outlet chambers to two can be achieved. For this reason, the salary is 9E.
Since the length of the pipe 4 can be made shorter than that shown in Fig. 1, the risk of shaft vibration can be reduced, and since the casing of the outlet chamber 612 is not filled with water, it is easier to seal the casing of the outlet chamber 612. It is possible to obtain a coolant lead-in/out device that can eliminate power loss due to friction with the coolant. 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 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 circumferential wall of the outlet chamber 612, making the collision sound very 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 fluid discharged from the discharge part by directly feeding the discharge part of the supply pipe E between the discharge part of the supply pipe E and the outlet chamber. A storage member is arranged so as to hold the cooling liquid in a liquid state and to have an outlet chamber and a fitting discharge path between the storage member and the supply/discharge pipe, and the cooling liquid held in a liquid state in the storage member is led out to the outside. The present invention provides a coolant lead-in/out device for a liquid-cooled rotor-type rotating electrical machine that achieves high reliability by forming a lead-out path in a housing member.

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 inside, which surrounds the small hole 10a which is the coolant discharge part of the supply/discharge pipe 4. It is attached to the wall of the outlet chamber 612 by a support member (not shown).
There are predetermined gaps between the inner peripheral surface of the one end 11a of the housing member 11 and the outer peripheral surface of the discharge ring 10, and between the inner peripheral surface of the pond end 11b of the housing member 11 and the outer peripheral surface of the outflow pipe 3. A gap G is provided, and this gap G forms a discharge path that is connected to the outlet chamber 612, from which a portion of the cooling liquid held in the storage member 11 in a water-filled state is discharged to the outlet chamber 612. Further, a lead-out path 12 consisting of a plurality of pipes is formed along the circumference within the wall of the housing member 11, and one end of this lead-out path 12 opens into the inside of the housing part village 11, and a right angle is formed inside the housing member 11. The other end, which is bent at 1, opens toward the vicinity of the outlet of the discharge path within the outlet chamber 612. With this configuration, the coolant kept in the storage part 11 in a full state is discharged to the outlet chamber 612 from both the discharger and the outlet path 12 through the gap G. In this invention configured as described above, the release ring 10
After keeping the cooling liquid discharged from the small hole 10a in the housing member 11 in a full state, cooling inside the housing member 11 is carried out from the discharge path in the gap G between the housing member il, the discharge ring 10, and the outflow pipe 3. A portion of the liquid is discharged into the outlet chamber 612.

On the other hand, the cooling liquid in the housing member 11 is also led out toward the supply/discharge pipe 4 side from the outlet path 12 formed in the housing member 11 . In this way, the small hole 10 of the release ring 10
The cooling liquid discharged from a is kept in the storage member 11 in a full state, and a part of the cooling liquid in the storage member 11 is discharged from the discharge path in the gap G to the outlet chamber 612, but the discharge speed is It can be made extremely low by adjusting the dimensions of the gap G and the lead-out path 12. On the other hand, by appropriately setting the gap G, the coolant discharged from the lower part of the supply pipe E pipe 4 among the discharge passages 12 can reach the outlet of the discharge passage of the supply pipe E pipe 4. . In this way, the coolant discharged from the discharge path is subjected to centrifugal force due to the rotation of the supply/discharge pipe 4 and scatters toward the inner circumferential wall of the outlet chamber 612, but the coolant discharged from the discharge path is It collides with the coolant flowing out from No. 12 toward the exit of the discharge channel, and the scattering speed is significantly reduced.
It is now prevented from dispersing. Therefore, the sound of the coolant hitting the inner circumferential wall of the outlet chamber 612 can be minimized. Furthermore, the sealing performance of the outlet chamber 2 is not deteriorated, and the inner circumferential wall of the outlet chamber 612 is prevented from being eroded. 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 as to maintain the inside of the accommodating member 11 in a water-filled state. In the above embodiment, the small holes 10a provided in the release ring 10' are arranged in two rows in the circumferential direction, but they may be arranged in one row or in three or more rows.

Further, although the discharge ring 1 is fixed to the inflow pipe 2 by a tight fit, it may be fixed by other means, or conversely, it may be fixed to the outflow pipe 3. Further, in the above embodiment, the discharge ring 10 and the outflow pipe 3 are separate bodies, but they can also be formed integrally. Further, according to the present invention, since the cooling liquid discharged from the small hole 10a of the discharge ring 10 is kept in the housing member 11 in a full state, the housing member 11 has the effect of preventing cavitation. Therefore, the discharge hole of the supply/discharge pipe 4 can be made somewhat larger.

The larger vent holes reduce the velocity of water passing through the vents, reducing corrosion of the vents. Also, from this, if the storage part village 11 is made to have a cavitation prevention effect, as shown in FIG. The liquid may be discharged from the portion 3a to the housing member 11, and the same effects as in the above embodiment can be achieved. 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. Further, in the above embodiment, a case has been described in which a plurality of lead-out passages 12 formed in the housing member 11 are provided in the circumferential direction, but it goes without saying that the number of lead-out passages 12 may be provided as required.

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.

Further, in the above embodiments, the present invention has been described 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 a rotating electrical machine such as an electric motor, if necessary.

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 supply/discharge pipe in the housing member in a full state, and transfers the cooling liquid between the discharge passage between the housing member and the supply/discharge pipe, and the housing member. Since the discharge passages formed in the member are discharged into the outlet chamber, the collision sound of the coolant can be significantly reduced, and the corrosion resistance and sealing performance of the outlet chamber can be significantly improved. A reliable coolant inlet/output device can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a coolant inlet/output device for a conventional liquid-cooled rotor-type rotating electrical machine, Fig. 2 is a cross-sectional view taken along the Rho 0 line in Fig. 1, and Fig. 3 is a diagram that was conceived before reaching this invention. FIG. 4 is a diagram showing a lead-in/out device, which is a further development of FIG. FIG. 6 is an enlarged view of a main part showing a coolant inlet/output device for a rotating electrical machine, and is a diagram for explaining another example of application of the present invention. In addition, 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 storage part village,
12 is a lead-out path. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A cooling fluid supply/discharge pipe coaxially connected to the rotor shaft, an outlet chamber provided surrounding the supply/discharge pipe and receiving the cooling fluid from the discharge portion of the supply/discharge pipe, and an annular shape with an inner opening. a housing member disposed in the outlet chamber surrounding the discharge portion; a discharge passage formed by a gap between the supply/discharge pipe and an inner circumferential end of the housing member; and a circle within the wall of the housing member. Cooling of a liquid-cooled rotor-type rotating electrical machine, comprising: a plurality of outlet passages formed along the circumference and configured as pipes for causing the cooling liquid in the accommodation member to flow out toward the vicinity of the outlet of the discharge passage. Liquid lead-in/out device.