JPS6038934B2 - 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 electrical machine that circulates a coolant around a rotor to cool the rotor, and particularly to a coolant inlet/output 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, until now, a cooling method that circulates hydrogen gas has been used to cool turbine generators.
Increases in single machine capacity have been achieved, but they are already at their limits, and hydrogen gas cooling cannot be expected to dramatically increase capacity beyond the current level. 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 normally rotates at a high speed of 3,600 revolutions per minute (60 days 2), and how to introduce and extract coolant into such a high-speed rotating body. This is the biggest problem and 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. The coolant is circulated within each tube and rotor coil as described below, so if water containing impurities is used as the coolant, the impurities may cause each tube and rotor coil to Therefore, it is desirable to use pure water that does not contain any impurities. 2 is a circular inflow pipe which has a closed part 2a and receives the cooling liquid from the inlet pipe 1 through this closed part;
The hollow interior 2b serves as an inflow path for the cooling liquid.

Reference numeral 3 designates a circular tubular outflow pipe provided around the inflow path 2 with a predetermined gap therebetween, and the gap 3b between the inflow pipe 2 and the inflow path 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 opening.

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 (the figure shows a case of 6) protruding 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 base 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, for example, by competitive fit, to form a supply/discharge pipe 4. 4a is a flange formed at the end of this supply/discharge pipe 4, and 5 is a rotor shaft of a rotating electric machine having a flange 5a that is in close contact with this flange and connected with, for example, a bolt (not shown). Needless to say, a rotor coil (not shown) is attached to the child shaft.

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 outflow path 3b of the feed 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 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 closed portion 3a, and in order to prevent the coolant (pure water) from coming into contact with the atmosphere and being contaminated, 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/discharge pipe 4 and the rotating supply/discharge pipe 4; This is the second exit chamber.

Unlike the first outlet chamber 61, this second outlet chamber 62 is not filled with cooling fluid, and therefore there is a risk that the cooling fluid (water) may come into contact with the atmosphere and be contaminated. Reference numeral 9 denotes a supply pipe for preventing kneading, and by constantly supplying drying gas such as nitrogen or hydrogen to the second outlet chamber 62 through this 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 the same as 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). A shelter inside the second exit chamber 62;
In order to seal the gas, the sealing liquid is passed from the sealing liquid supply pipe 84 to the second outlet chamber 62 , and the sealing liquid, which has a pressure slightly higher than that of the gas, is transferred to the third outlet chamber of the labyrinth seal 83 , that is, the downstream outlet chamber 63 . Supplied at the end. Although the sealing liquid slips through the labyrinth seal 83 and leaks into the second outlet chamber 62,
As described above, since the cooling liquid drawn out from the second outlet chamber 62 is recirculated without being purified, the sealing liquid must be the same pure water as the cooling liquid. In addition, since the sealing liquid flows toward the second outlet chamber 62 in the gap between the labyrinth seal 83 and the supply/discharge pipe 4, the cooling liquid passes through the labyrinth seal 83 and enters the downstream outlet chamber, that is, the third outlet. It is impossible for the liquid to flow out to room 63. On the other hand, since the air enters the third outlet chamber 63, which is the downstream outlet chamber, the sealing liquid leaking into the third outlet chamber 63 becomes contaminated with the air and must be discarded. Of course, it is possible to purify the water and reuse it, but whether it is discarded or reused, in order to prevent the size of the water purification equipment or water purification treatment equipment, it is necessary to It is necessary to suppress leakage into the outlet chamber 63 as much as possible. 4b is a sealing liquid supply pipe 84 on the outer periphery of the supply/discharge pipe
The screw is machined in the opposite direction to the rotating direction on the third outlet chamber 63 side, and during high-speed rotation, the pumping effect created by the opposing stationary surface prevents sealing fluid from leaking into the third outlet chamber 63. The amount can be kept to an extremely small value.

Further, 86 is the supply/discharge pipe 4 on the third outlet chamber 63 side from the screw 4b.
An annular rubber provided to surround the annular rubber 86, and when it is stationary, compressed gas is supplied from the air supply pipe 87 to the outer peripheral side of the annular rubber 86 to press the annular rubber 86 to the outer peripheral surface of the supply/discharge pipe. Accordingly, leakage of the sealing liquid to the third outlet chamber 63 can be prevented. If the shape of the annular rubber 86 is as shown in Fig. 1, the rubber thickness is much smaller than the inside of the rubber, and therefore the air pressure required to deform the annular rubber is extremely small, the pressure of the sealing fluid will be In FIG. 1, the left side of the annular rubber 86 is shown, and the pressure of the compressed air supplied by the air supply pipe 87 acts to spread the annular rubber 86 outward. Therefore, even if the pressure of the compressed air is slightly lower than the pressure of the sealing fluid, it is possible to press the annular rubber 86 onto the outer peripheral surface of the supply/discharge pipe 4. Furthermore, since there is a slight gap between the annular rubber 86 and its retaining ring 88, compressed air leaks little by little, so it is necessary to constantly replenish the compressed air.

FIG. 3 is a system diagram of an air supply pipe line that supplies compressed air to the annular rubber 86 that has been considered in the past.

87a is an air supply pipe leading to a compressed air source; 87b is an exhaust pipe open to the atmosphere for removing compressed air from the annular rubber 86; and 90 is an air supply valve provided in the middle of the air supply pipe 87a. The supply 9E is opened while the pipe 4 is stationary, closed before rotating, and kept closed during rotation.

Reference numeral 91 denotes an exhaust valve provided in the middle of the exhaust pipe 87b, which is closed while the supply/discharge pipe 4 is stationary, opened before rotation, and kept open during rotation.

In the above system, if the compressed air source fails and the pressure of the compressed air decreases while the supply/discharge pipe 4 is stationary, the annular rubber 86 will be pushed by the pressure of the sealing fluid and spread outward, causing the annular rubber 86 and the supply/discharge pipe 9E to expand. A gap is created between the pipe 4 and the outer circumferential surface of the pipe 4, and the sealing liquid supplied to seal the gas passes through the gap and flows into the third outlet chamber 63.

Of course, since the supply pipe 4 is stationary, the screw 4b provided on the outer circumferential surface of the supply/discharge pipe 4 has no pumping effect, and therefore the amount of sealing fluid flowing into the third outlet chamber 63 is reduced during rotation. The third outlet pipe 73 needs to be made several tens of times larger than the amount of sealing liquid flowing into the outlet chamber 63. If the size of the third outlet pipe 73 is planned according to the amount of sealing liquid flowing out into the third outlet chamber 63 during rotation, the sealing liquid flowing into the third outlet chamber 63 will be transferred to the third outlet. It accumulates in the chamber and eventually leaks to the outside through the gap between the labyrinth seal 84 and the staff E pipe 4.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and in the unlikely event that the compressed air source malfunctions for some reason while the supply/exhaust pipe is stationary, the compressed air pressure drops. Instead of this compressed air, a sealant is sealed in the second outlet chamber to prevent contamination of the coolant, and by supplying gas to the annular rubber, the sealing liquid is transferred to the third outlet chamber. The aim is to provide a safe device that can prevent spills.

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

In FIG. 4, 87c is the second outlet chamber 62 and the air supply pipe 87.
92 is a check valve installed in the middle of the air supply pipe 87a to prevent backflow to the air supply source; 93 is a check valve installed in the middle of the pressure pipe 87c to the second outlet chamber 62. This is a check valve installed in a direction that prevents backflow.

Reference numeral 94 denotes an air supply valve provided in the middle of the pressure impulse pipe 87c, which is opened at the same time as the exhaust valve 91 is closed when the supply pipe 4 is stationary and the air supply valve 90 is opened.

With this configuration, the supply/discharge pipe 4 is stationary and the 8E air valve 9
1 is closed, the air supply valves 90 and 94 are opened, compressed air is supplied to the annular rubber 86, and the annular rubber 86 is crimped onto the outer peripheral surface of the supply/discharge pipe 4, thereby creating a space between the second pressure chamber and the third pressure chamber. Even if some kind of failure occurs in the air supply source and the pressure of the compressed air decreases while the air supply is sealed, the gas will still flow through the second outlet chamber 62 and into the annular rubber 86 via the air supply pipe 87c. Since the annular rubber 86 is supplied, the state in which the annular rubber 86 is crimped to the outer peripheral surface of the supply BE pipe 4 can be maintained.

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. 5, 612 is the outlet chamber 6 in FIG.
1 and 62 are integrated into an upstream side outlet chamber, 712 is an outlet pipe that fits into this upstream side outlet chamber 612, and 9 is an air supply pipe similar to that shown in FIG. 1, which fills the upstream side 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.

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 various rotating electric machines such as electric motors, if necessary. .

In this way, according to the present invention, a pressure pipe is provided that connects the upstream outlet chamber filled with gas and the air supply pipe to the annular rubber, and the pressure pipe is provided in the middle of the pressure pipe to prevent the gas from flowing back to the outlet chamber. Since a check valve is provided in the air supply pipe to the annular rubber to prevent backflow to the compressed air source, compressed air can be supplied to the annular rubber 86 while the supply/discharge pipe 4 is stationary. By pressing the annular rubber 86 onto the supply BE pipe 4, the second outlet chamber 62 and the third outlet chamber 63 are formed.
Even if the pressure of the compressed air drops for some reason, the pressure of the sealing gas sealed in the second outlet chamber 62 will be applied to the annular rubber 86 and the sealing liquid will be released. This has the effect of providing a safe device that can prevent leakage into the third outlet chamber 63.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the coolant inlet/output device, Fig. 2 is a cross-sectional view taken along the low-0 line in Fig. 1, Fig. 3 is a system diagram of the secondary air supply pipe, and Fig. 4 is a diagram showing one example of this invention. FIG. 5, a system diagram of the air supply pipe line according to the embodiment, 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, 5a is its flange, 5b is an inflow path, 5c is an outflow path, 61, 612 is an upstream outlet chamber, 6
2 is an intermediate outlet chamber, 63 is a downstream outlet chamber, 71, 72, 7
3,712 is an outlet pipe, 81, 82, 83, 84 are labyrinth seals, 9, 87 are air supply pipes, 84 is a sealing liquid supply pipe,
85 is a stationary surface, 86 is an annular rubber, 4b is a screw provided on the outer periphery of the supply pipe 8E in the opposite direction of rotation, 87a is a supply pipe, 87b is an exhaust pipe, 90, 91, 94 are valves, 92, 9
3 is a check valve, 87c is a pressure conduit, and 88 is a retaining ring. Figure 2 Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A supply/discharge pipe directly connected to the rotor shaft that supplies and discharges the coolant that cools the rotor of the rotating electric machine, and a supply/discharge pipe that is provided surrounding the supply/discharge pipe to receive and cool the above-mentioned coolant discharged from the supply/discharge pipe. There is an upstream outlet chamber filled with a coolant gas at a pressure higher than atmospheric pressure to prevent contamination of the liquid by the atmosphere, and a chamber provided in the axial direction of this upstream outlet chamber to prevent leakage of cooling liquid from the upstream outlet chamber. a downstream outlet chamber for receiving the cooling liquid, an annular expandable body that prevents passage of the cooling liquid between one end of the downstream outlet chamber and the supply/discharge pipe;
An air supply pipe that supplies compressed air to press the annular expandable body against the outer circumferential surface of the supply/discharge pipe, and a pressure pipe that connects the air supply pipe and the above-mentioned upstream outlet chamber, and the pressure pipe connects the upstream side 1. A cooling liquid lead-in/out device for a liquid-cooled rotor-type rotating electric machine, characterized in that the coolant gas in the outlet chamber is guided to the annular expandable body.