JP3387941B2 - Multi-stage hydraulic machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage hydraulic machine applied to a pump turbine or the like, and more particularly to a multi-stage hydraulic machine that carries out a water surface depression operation at the time of starting the pump or performing a phase adjusting operation.

[0002]

2. Description of the Related Art Generally, in turbines and pump turbines, the movable guide vanes and the inlet valve are fully closed when the pump operation is started, in order to perform a phasing operation for the purpose of improving the power factor of the electric system and adjusting the system frequency. The so-called idling operation is performed by pressing down the water surface around the runner with compressed air to reduce the load.

In a two-stage pump turbine in which the high-pressure stage to the low-pressure stage are connected by return passages and movable guide vanes are installed on the outer circumference of each stage runner, when performing the above-mentioned water surface pushing operation, each stage It is necessary to provide an exhaust path that opens to the innermost side of the runner flow path for each case, and to smoothly perform the return operation from the water surface depression operation to the power generation / pumping operation.

The conventional 2 which performs such a water surface pushing operation
An example of the multi-stage pump turbine will be described with reference to FIG.

FIG. 11 shows a cross section of a main part of a two-stage pump turbine, and shows a state when returning from the water surface pushing operation to the normal operation. In the figure, a main shaft 1 is provided with a high pressure stage runner 2 and a low pressure stage runner 3. A movable guide vane 4 is attached to the outer periphery of the high pressure stage runner 2, and a space 6 behind the high pressure stage runner 2 is provided between the outer peripheral surface of the main shaft 1 and the inner peripheral portion of the upper cover 5 which faces the outer peripheral surface. Pressure water is the main spindle 1
A spindle water seal device 7 is provided to prevent leakage from the outer peripheral surface.

Further, the high pressure stage runner 2 is provided with a communication passage 9 for connecting the runner chamber 11 and the space 6 at the back of the runner, and one end of the upper cover 5 is opened in the space 6 at the back of the runner. An exhaust pipe 10 having the other end reaching the outside is provided. A control valve (not shown) is interposed in the middle of the exhaust pipe 10, and is opened when returning from the water-pushing operation to the normal operation to form an exhaust passage for exhausting the compressed air in the high-pressure stage runner chamber 11. There is.

The low pressure stage runner 3 and the high pressure stage runner 2 are communicated with each other by a return flow passage 12, and a movable guide vane 13 is also provided on the outer periphery of the low pressure stage runner 3 of the return flow passage 12. The low-pressure stage runner 3 has a low-pressure stage runner chamber 1
4 and the runner back space 15 are provided to communicate with each other, and the upper cover 17 is provided with an exhaust pipe 18 having one end open to the runner back space 15 and the other end to the outside. A control valve (not shown) is provided in the middle of the exhaust pipe 18, and the compressed air in the low pressure stage runner chamber is exhausted by opening the control valve when returning from the water surface pushing operation to the normal operation. It forms an exhaust path.

In the conventional two-stage pump configured as described above, when the water surface rises in each stage runner chamber as the compressed air is exhausted in order to return from the water surface pushing operation to the normal operation. Since the stage runners 2 and 3 attached to the main shaft 1 are rotating, the water reaching the stage runners is repelled to the outer peripheral side, and the water is filled from the outer peripheral side of the respective stage runner chambers. At this time, since the exhaust passages provided in each stage are opened to the inner peripheral side passages of each runner, the compressed air does not remain in each stage runner chamber, and the exhaust passages shown by the arrows in FIG. Since it is exhausted to the outside through the, the operation of returning from the water surface pushing operation to the normal operation can be performed without any problem.

However, once the normal operation is restored, the high pressure stage runner chamber 11 and the space 6 behind the high pressure stage runner 6
Are connected by a communication passage 9 to the space 6 at the back of the runner, that is, at the outlet pressure of the high-pressure stage runner 2, that is, half of the head during power generation operation, half of the head during pumping operation, or the head of pumping operation. High pressure of about half is applied. Therefore, the spindle water sealer 7 must seal the high pressure water filling the space 6 at the back of the runner, and is exposed to extremely severe usage conditions. As a result, the packing of the spindle water seal device 7 is severely worn, and in a significant case, there is a risk of burning the packing and further damaging the spindle 1.

Further, the resultant force of water pressure acting before and after the runner of the hydraulic machine is different, and the difference in water pressure acts as an axial thrust on the main shaft. In order to adjust the axial thrust, the front and rear of the runner are connected by a balance pipe or a balance hole to reduce the axial thrust. Similarly, in the case of a two-stage pump turbine, a balance pipe is connected between the front and rear of each runner for adjusting the thrust.

FIG. 12 shows another conventional example. In this example, a pipe line 19a that communicates the inner back pressure chamber 6 of the high pressure stage with the suction pipe 19 is provided to eliminate the intermediate seal on the back side of the low pressure stage runner and shift the position of the intermediate seal 6a on the back side of the high pressure stage runner to the inside. At the time of shifting from idling operation to refilling operation, the water pressure is established from the high pressure stage runner, and then effective thrust control can be performed on condition that the low pressure stage runner is replenished with water. .

However, regarding the exhaust, only the condition that the water pressure from the high pressure stage runner chamber is established is established, and no particular consideration is given to the exhaust method.

In the two-stage pump turbine having the simple structure shown in FIG. 12 and capable of controlling the thrust, the high-pressure stage runner chamber 11 is surely provided.
It is an absolute condition to establish the exhaust water pressure from the above, and if the water pressure is established first from the low pressure stage runner chamber 14,
As shown in the pressure distribution diagram around the runner in FIG. 13, only the thrusts e, f, g, h acting on the low-pressure stage runner 3 are generated, so that an excessive downward axial thrust is generated. On the other hand, when the water pressure is established from the high pressure stage runner chamber 11, the thrusts a and b acting on the high pressure stage runner 2 are always balanced as shown in FIG. Since the pressure is substantially the same as the pressure of the suction pipe 19, by balancing c and d as well, the overall thrust balance is maintained. Therefore, it is necessary to reliably establish the water pressure from the high pressure stage runner chamber 9.

[0014]

In the conventional multistage hydraulic machine, once the normal operation is restored, the high pressure stage runner chamber 1
Since 1 and the space 6 behind the high-pressure stage runner are connected by the communication passage 9, the outlet pressure of the high-pressure stage runner 2, that is, half of the drop during power generation operation or the drop during pumping operation, is connected to the space 6 behind the runner. A high pressure of about half of the above or about half of the head during pumping operation is applied. Therefore, the spindle water sealer 7 must seal the high pressure water filling the space 6 at the back of the runner, and is exposed to extremely severe usage conditions.
As a result, the packing of the spindle water seal device 7 is heavily worn, and in a significant case, there is a risk of burning the packing and further damaging the spindle 1, which is a serious problem.

Further, regarding the exhaust, only the condition that the water pressure from the high pressure stage runner chamber is established is required, and although no particular exhaust method is known, it is necessary to surely establish the water pressure first from the high pressure stage runner chamber 11. Is.

The present invention has been made in view of the above circumstances. A first object of the present invention is to smoothly perform a returning operation from a water-pushing operation to a normal operation, and to keep the main shaft always operating even if the operating state changes. An object of the present invention is to provide a multi-stage hydraulic machine that can reduce the water pressure applied to the water sealing device. That is,
Secure an exhaust path for exhausting compressed air when returning to normal operation from the water surface depression operation through the water filling operation (exhaust operation), and from the water surface depression operation through the water filling operation (exhaust operation) to the normal operation At the time of restoration, the compressed air in the high and low pressure stage runner passages can be completely exhausted without causing exhaust congestion, and the water pressure applied to the main shaft water sealer can be constantly reduced even after restoration in normal operation. To provide a multi-stage hydraulic machine.

The second purpose is to establish the water pressure in the low-pressure stage runner chamber after the high-pressure stage runner chamber has established the water pressure when returning from the water-pushing operation to the normal operation through the water filling operation (exhaust operation). It is intended to provide a multi-stage hydraulic machine in which compressed air is secured so as to perform a smooth operation of returning from the water surface pushing operation to the water filling operation (exhaust operation) to the normal operation.

[0018]

The invention according to claim 1 is the first
In order to achieve the purpose of, the high pressure stage to the low pressure stage are connected by a series of return flow paths, and the main shaft sealing device is provided between the outer periphery of the main shaft above the high pressure stage runner and the stationary part, and the main shaft sucks out. In a multi-stage hydraulic machine having a high-pressure runner chamber and a low-pressure runner chamber that are provided through the pipe and have a supply / discharge section for pressurized air for pushing down the water surface, in the main shaft, from the low-pressure runner chamber to the outside. An exhaust passage leading to the low pressure stage runner chamber is provided in the main shaft separately from the exhaust passage.
A return pipe that forms an exhaust path from the high pressure stage runner chamber to the outside and connects the high pressure stage runner chamber and the low pressure stage runner chamber to each other and a suction pipe that connects the suction pipe connected to the low pressure stage runner chamber are provided. It is characterized by being provided.

According to the second aspect of the present invention, the exhaust passage extending from the high pressure stage runner chamber to the outside is provided in the center of the main shaft, while the exhaust passage extending from the low pressure stage runner chamber to the outside is located around the exhaust passage in the center. It is provided at a concentric position or an eccentric position.

In order to achieve the second object, the invention according to claim 3 is connected by a series of return flow passages from the high pressure stage to the low pressure stage, and between the outer periphery of the main shaft above the high pressure stage runner and the stationary part. In the multi-stage hydraulic machine, which has a main shaft water sealing device, a main shaft is provided through the suction pipe, and which has a high pressure stage runner chamber and a low pressure stage runner chamber having a supply / discharge unit of pressurized air for pressing down the water surface, In the main shaft that penetrates the inside of the suction pipe,
An exhaust passage extending from the low-pressure stage runner chamber to the outside is provided, and an exhaust passage communicating from the high-pressure stage runner chamber to the low-pressure stage runner chamber is formed in the main shaft, apart from the exhaust passage from the low-pressure stage runner chamber. , And a return pipe that connects the high-pressure stage runner chamber and the low-pressure stage runner chamber to each other and a suction pipe that connects the suction pipe that connects to the low-pressure stage runner chamber. Is also equipped with a water supply pipe that guides high-pressure water from the outside.

[0021]

According to the invention of claim 1, an exhaust passage extending from the low pressure stage runner chamber to the outside is provided in the main shaft, and an exhaust passage extending from the high pressure stage runner chamber to the outside is formed from the low pressure stage runner chamber. Separately formed in the spindle, high pressure water is not loaded on the spindle water seal device during normal operation,
In addition, the compressed air in the runner passage of each stage after the water surface pressing operation at the time of starting the pump or the phase adjusting operation can be reliably and completely exhausted. In other words, high pressure is not applied to the spindle water sealer during normal operation, and compressed air in the runner passages at each stage after the water surface pressing operation during pump startup or phase adjustment operation must be reliably exhausted. You can

Particularly, since the exhaust passage of the high-pressure stage runner chamber and the exhaust passage of the low-pressure stage runner chamber are separated, after the water filling operation (exhaust operation) of one runner chamber is completed, the other runner chamber is connected to the other runner chamber. Since water (filled water) does not flow in, exhaust congestion can be prevented, and exhaust in both runner chambers can be performed quickly and reliably.

According to the third aspect of the invention, an exhaust passage extending from the low pressure stage runner outlet to the outside is provided in the main shaft, and an exhaust passage extending from the high pressure stage runner outlet to the outside is exhausted from the low pressure stage runner outlet. By forming it in the main shaft separately from the passage, it is possible to secure an exhaust passage for exhausting compressed air when shifting from water-pushing operation to normal operation, and to establish the water pressure in the high-pressure stage runner chamber first. Thrust imbalance does not occur and the return operation to normal operation can be performed smoothly. Further, since the high-pressure stage runner chamber and the main shaft water sealing device section are not in communication with each other, the high pressure water is not loaded on the main shaft water sealing device during normal operation, and safe operation is possible.

Furthermore, since the exhaust passage of the high-pressure stage runner chamber and the exhaust passage of the low-pressure stage runner chamber are separate, it is possible to surely and quickly terminate the exhaust without causing exhaust congestion. Furthermore, a water supply pipe for supplying water having a pressure higher than that of the suction pipe is provided in the return flow passage, and the air stagnant in the return flow passage is discharged by overcoming the flow passage resistance, so that the exhaust can be finished earlier.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals are used for the same components as the conventional one.

1 to 4 show the first embodiment.

This embodiment relates to a two-stage pump turbine having movable guide vanes at both the high pressure stage and the low pressure stage.

A high-pressure stage runner 2 and a low-pressure stage runner 3 are fixed on the shaft of the water turbine main shaft 1 at a fixed distance in the axial direction. The high pressure stage runner 2 includes an upper cover 5 and a lower cover 2.
It is housed in a high pressure stage runner chamber 11 surrounded by 0. Further, between the outer peripheral surface of the main shaft 1 and the upper cover 5 which faces the outer peripheral surface of the main shaft 1, a main shaft water seal device 7 is attached to prevent the back pressure water of the high pressure stage runner 2 from leaking from the outer peripheral surface of the main shaft 1. Has been. The low-pressure stage runner 3 is housed in a low-pressure stage runner chamber 14 which is surrounded by the upper cover 17 and the lower cover 21.

High pressure stage runner chamber 11 and low pressure stage runner chamber 14
Are connected by the return passage 12, and a plurality of return blades 22 are arranged in this passage. Further, a casing 44 is arranged outside the high pressure stage runner chamber 11,
The vortex chamber and the high pressure stage runner chamber 11 communicate with each other.

Further, outside the high pressure stage runner chamber 11,
While the movable guide vanes 4 are provided, similar movable guide vanes 13 are also provided outside the low pressure stage runner chamber 14, and these movable guide vanes can be controlled to open and close by independent operating mechanisms. .

Furthermore, an elbow type suction pipe 19 is connected to the low pressure stage runner chamber 14, and the downstream side thereof communicates with a water discharge passage (not shown).

The exhaust passage of the high pressure stage runner chamber 11 is provided in the main shaft 1, and the outer exhaust passage 24 from the exhaust port 23 communicating with the high pressure stage runner chamber 11 to the G / M coupling.
And an upper exhaust chamber 25 provided in the G / M coupling section,
Inner exhaust passage 2 from upper exhaust chamber 25 to lower exhaust chamber 27
An exhaust pipe 40 is connected to the lower exhaust chamber 27 by incorporating an exhaust valve 42 in the pipeline. For the inner exhaust passage 26, a pipe is inserted in the center of the main shaft 1 and the upper end (G
/ M coupling part) and fixed by seal welding.

Similarly, the exhaust passage of the low pressure stage runner chamber 14 is also provided inside the main shaft 1, and has a radial exhaust passage 29 extending from the exhaust receiving port 28 communicating with the low pressure stage runner chamber 14 to the main shaft center direction. It is composed of an exhaust passage 26 inside the high-pressure stage runner, an axial exhaust passage 30 having a double pipe structure, and an exhaust chamber 31 provided at the lower end of the main shaft. In the exhaust chamber 31, an exhaust pipe 41 is exhausted on the pipeline. The valve 43 is incorporated and connected.

Each exhaust chamber 2 provided at the lower end of the main shaft 1
7 and 31 are sealed by the water sealing device 33, respectively, and have a structure in which the high pressure water from the high pressure stage runner chamber 11 does not circulate during normal operation. The exhaust valves 42 and 43 are controlled by the output signals of the pressure relays 34 and 35 which detect the establishment of the priming water pressure at the outer peripheral portions of the runners in the high pressure stage runner chamber 11 and the low pressure stage runner chamber 14, respectively.

Further, in the upper part of the suction pipe 19 and in the middle of the return flow path 12, as shown by a broken line in FIG.
6 of the branch pipes 36A and 36B are connected to each other, and air supply valves 37A and 37B are incorporated in the pipelines of the branch pipes 36A and 36B.

Further, the water in the return passage 12 is sucked out of the pipe 1.
A water distribution pipe 38 directly leading to the water distribution pipe 9 is provided, and a water distribution valve 39 provided in this water distribution pipe is normally closed.

When the two-stage pump turbine having the above structure is operated by the turbine, the pressure water from the penstock flows into the casing 44, and this water flow causes the movable guide vanes 4 in the high-pressure stage and the high-pressure runner chamber 11 to flow. After passing through, the return flow passage 12 flows into the low pressure stage runner chamber 14 through the movable guide vanes 13 of the low pressure stage portion, and flows into the suction pipe 19.

On the other hand, when the pump is operating, the low pressure stage runner 3
The water flow pumped by the water flows from the suction pipe 19 to the penstock by way of a route opposite to that in the operation of the water turbine.

Next, the procedure of pushing down the water surface of the two-stage pump turbine according to this embodiment and the exhaust operation will be described.

First, after closing the movable guide vanes 4 of the high pressure stage and the movable guide vanes 13 of the low pressure stage, the air supply valve 3 is closed.
7A and 37B are opened, and compressed air is blown into the return passage 12 and the upper suction pipe 19. In this state, the exhaust valve 4
2, 43 are closed and the water distribution valve 39 is opened.

Then, the water in the return passage 12 is distributed to the water distribution pipe 38.
Through the suction pipe 19 and is pushed down through the suction pipe 1.
The water in the upper part of the inside of 9 is also pushed down, and the state after pushing down the water surface becomes the state shown in FIG. 2. At this point, the air supply valve 37
Close A and 37B.

The high-pressure stage runner 2 and the low-pressure stage runner 3 are idly started in the pump direction, and when the rated number of revolutions is reached and they are in parallel with the system, the exhaust valves 42 and 43 are opened.

As a result, the air in the high pressure stage runner chamber 11 and the low pressure stage runner chamber 14 is exhausted through the exhaust passages provided in the main shaft 1, the water levels in the return passage 12 and the suction pipe 19 rise, and eventually. When the blades of the high-pressure stage runner 2 and the low-pressure stage runner are flooded, the water is blown to the outer periphery of the runner by centrifugal force, and as shown in FIG.
1, 14 are filled with water from the outer peripheral side. Further, the pressure relay 3 indicates that exhaust has progressed, the runner chamber has been completely filled with water, and the priming pressure at the outer peripheral portions of the runners 2 and 3 has been established.
4, 35 are used for detection, and the exhaust valves 42, 43 and the water distribution valve 39 are closed.

After confirming that these valves are closed,
First, the movable guide vane 13 in the low pressure stage is opened, then the movable guide vane 4 in the high pressure stage is opened, and the pump operation is started.

At the final stage of the above-described exhaust process, compressed air tends to remain in the central portions of the runner chambers 11 and 14 of each stage as shown in FIG. 4, but according to this embodiment, each runner is The compressed air remaining in the chambers 11 and 14 enters the exhaust passage penetrating the inside of the main shaft 1 via the exhaust receiving ports 23 and 28 provided in the main shaft 1, and the exhaust chambers 27 and 31 are further exhausted.
After being guided to, the exhaust pipes 40, 41 enter and are discharged through the open exhaust valves 42, 43.

Therefore, according to this embodiment, the compressed air of the high-pressure stage runner 2 and the low-pressure stage runner 3 can be exhausted smoothly and surely, and the main shaft water seal device portion of the main shaft 1 is normally operated. Sometimes high pressure water is not applied.

5 to 8 show a second embodiment of the present invention.

In this embodiment, the upper end of the high-pressure stage exhaust passage provided in the main shaft 1 is at the same height as the high-pressure stage runner chamber exhaust receiving port, and the exhaust from the high-pressure stage runner chamber exhaust receiving port is guided directly downward. It is like this.

Further, the low pressure stage exhaust passage is composed of a plurality of independent holes formed at eccentric positions of the main shaft.

Since the other structure is substantially the same as that of the first embodiment, the corresponding parts in the drawing are designated by the same reference numerals as those in FIG. 1 and their explanations are omitted.

According to the second embodiment as described above, the same effect as that of the first embodiment can be obtained.

FIG. 9 shows a third embodiment of the present invention.

In this embodiment, from the high pressure stage to the low pressure stage are connected by a series of return flow passages 12, movable guide vanes 4 and 13 are provided at each stage, and an outer spine is provided around the high pressure stage runner 2. A pressure chamber 47, an inner back pressure chamber 6 and a side pressure chamber 48 are provided.

Further, a pipe line 55 for connecting the inner back pressure chamber 6 of the high pressure stage and the suction pipe 19 is provided, and the low pressure stage runner 3 is provided.
There is no intermediate seal on the back, and the intermediate seal 46 on the back of the high-pressure stage runner 2 is provided at a shifted position so that effective thrust control can be performed with a simple structure.

When the idling operation is changed to the water filling operation, the water pressure is established from the high pressure stage runner chamber 11 and then the low pressure stage runner chamber 14 is filled with water.

That is, the exhaust passage of the high pressure stage runner chamber 11 is provided inside the main shaft 1, and the exhaust passage 26 from the exhaust receiving port 23 communicating with the high pressure stage runner chamber 11 to the lower exhaust chamber 27, and the lower exhaust passage. Exhaust pipe 4 for low pressure stage exhaust passage from chamber 27
The exhaust pipe 40 communicating with 1 is connected by incorporating an exhaust valve 42 on the pipe line.

Similarly, the exhaust passage of the low pressure stage runner chamber 14 is provided inside the main shaft 1, and the exhaust passage 30 from the exhaust port 28 communicating with the low pressure stage runner chamber 14 to the low pressure stage exhaust chamber 31 is provided. An exhaust pipe 41 is connected to the exhaust chamber 27 by incorporating an exhaust valve 43 on the conduit.

Further, the low pressure stage runner chamber 14 is provided with an exhaust pipe 50 for discharging the compressed air discharged from the high pressure stage runner chamber 11 to the outside, and an exhaust valve 51 provided in the exhaust pipe 50 is provided with an exhaust valve 51. It is controlled by a pressure relay 52 which detects the establishment of water pressure on the outer peripheral portion of the runner.

Further, in the return flow passage 12, a water supply valve 54 is installed on the pipe line in order to fill the high pressure stage runner chamber 11 with water, and a water supply pipe 53 for supplying water of a pressure higher than that of the suction pipe 19 is provided. ing.

Since the other construction is substantially the same as that of the second embodiment, the corresponding portions in the drawing are designated by the same reference numerals as those in FIG. 5 and their explanations are omitted.

With respect to the two-stage pump turbine of the third embodiment having the above-mentioned structure, the operation method from the water surface pushing operation to the exhaust operation and the normal operation will be described.

When shifting from the stopped state to pushing down the water surface, the movable guide vanes 4 and the low pressure step guide vanes 13 are closed,
Air is supplied from the air supply pipe 36 opened to the high-pressure stage part and the low-pressure stage part, and the water levels of the high-pressure stage runner chamber 11 and the low-pressure stage runner chamber 14 are simultaneously pushed down. At this time, the water in the high-pressure step portion is drained through the water distribution pipe 38.

Next, when the air in the flow passage is exhausted as a transition from the water surface pushing operation to the water filling operation (exhaust operation) to the normal operation, first, it is connected to the lower exhaust chamber 27. The exhaust valve 42 is opened, the exhaust valve 43 connected to the lower exhaust chamber 31 is closed, and high-pressure water is guided from the water supply pipe 53 provided in the return passage 12. As a result, the air in the high pressure stage portion overcomes the flow passage resistance of the return flow passage and the exhaust port 23 and the high pressure stage exhaust passage 2 provided in the main shaft 1.
Enter the lower exhaust chamber 27 through 6.

The air from the lower exhaust chamber 27 is supplied to the exhaust pipe 4
The exhaust gas is exhausted into the low pressure stage runner chamber 14 through the exhaust passages 0, 41 and the low pressure stage exhaust passage 30, and is exhausted to the outside by the exhaust pipe 50.

During the exhaust stroke, the high pressure water is supplied from the return passage by the main shaft 1 on the rotating side and the return passage portion 12 on the fixed side.
Is provided with a gap 57 for contact prevention, and when water is supplied by the discharge channel water pressure, compressed air in the lower runner chamber 14 leaks to the high pressure runner chamber 11 through this gap 57,
This is because the water level in the low pressure stage runner chamber 14 may rise during the exhaust stroke of the high pressure stage runner chamber 11, the water surface may interfere with the low pressure stage runner 3, and the water pressure in the low pressure stage runner chamber 14 may be established first.

Next, when the exhaust of the high pressure stage is completed, the exhaust valves 42 and 51 and the water supply valve 54 are closed, and the exhaust valve 43 of the lower exhaust pipe is opened. The exhaust gas is discharged to the outside through the exhaust receiving port 28, the exhaust passage 30, and the lower exhaust chamber 31.

As described above, when the water pressure pushing operation is changed to the normal operation after the water filling operation (exhaust operation), the high pressure stage runner chamber can establish the water pressure before thrust control. The thrust unbalanced state as shown does not occur, and reliable exhaust operation can be performed while maintaining a safe thrust balance.

FIG. 10 shows a fourth embodiment of the present invention.

In this embodiment, the balance pipe 55 and the balance valve 56 in the third embodiment are omitted, and the other structure is substantially the same as that of the third embodiment.

In this embodiment as well, as in the third embodiment, a reliable exhaust operation can be performed while maintaining a safe thrust balance.

[0071]

As described above, according to the present invention, the exhaust passage for exhausting compressed air when returning from the water surface pushing operation to the normal operation through the water filling operation (exhaust operation) serves as a high pressure stage runner chamber. Separately secured in the low-pressure stage runner chamber, when returning from water pressure operation to normal operation, the compressed air in the upper low-pressure stage runner flow path can exhaust completely without causing exhaust congestion, and also returns to normal operation However, the water pressure applied to the main shaft water seal device can always be reduced.

Further, according to the present invention, when the water pressure is established in the high pressure stage runner chamber, the water pressure is established in the low pressure stage runner chamber when returning from the water surface pushing operation to the normal operation through the water filling operation (exhaust operation). The compressed air is secured so as to perform the operation, and the return operation from the water surface pushing operation to the normal operation can be smoothly performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a push-down operation state according to the embodiment.

FIG. 3 is an explanatory view showing an exhaust action according to the embodiment.

FIG. 4 is an explanatory diagram showing a normal operation state according to the embodiment.

FIG. 5 is a configuration diagram showing a second embodiment of the present invention.

FIG. 6 is an explanatory view showing a push-down operation state according to the embodiment.

FIG. 7 is an explanatory diagram showing an exhaust action according to the embodiment.

FIG. 8 is an explanatory diagram showing a normal operation state according to the embodiment.

FIG. 9 is a configuration diagram showing a third embodiment of the present invention.

FIG. 10 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a conventional example.

FIG. 12 is a diagram showing another conventional example.

FIG. 13 is an operation explanatory view of a conventional example.

[Explanation of symbols]

1 spindle 2 High pressure stage runner 7 Spindle water seal device 11 High pressure stage runner room 12 Return flow path 14 Low pressure runner chamber 19 Suction tube 24, 26, 30 exhaust path 53 Water pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teiichi Umeda 1824 Koshidaue, Osu character, Kajio-mura, Motosu-gun, Gifu Prefecture, Chuo Electric Power Co., Inc. Okuminomizu Power Plant (72) Inventor Masaharu Nonaka Tsurumi, Yokohama, Kanagawa Prefecture 2 Suehiro-cho, 2-share company Toshiba Keihin Office (72) Inventor Sadao Kurosawa 2-4 share company, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa Prefecture In-house Toshiba Keihin Office (72) Inventor Yozo Kawase Tsurumi Yokohama, Kanagawa Prefecture 4 Suehiro-cho, ward, Toshiba Corporation Keihin Works (56) References JP-A-57-176364 (JP, A) JP-A-54-142436 (JP, A) JP-A-57-81164 (JP, A) ) JP-A-57-59070 (JP, A) Actual development 2-48667 (JP, U) Actual development 57-73378 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F03B 1/00-11/08

Claims (3)

(57) [Claims] 1. A high pressure stage low pressure stage is connected by a series of return flow passages, and a main shaft sealing device is provided between the outer periphery of the main shaft above the high pressure stage runner and a stationary part, and the main shaft penetrates the suction pipe. In a multi-stage hydraulic machine having a high-pressure runner chamber and a low-pressure runner chamber, each having a supply / discharge section for pressurized air for pushing down the water surface, an exhaust passage extending from the low-pressure runner chamber to the outside in the main shaft. In addition to the exhaust passage from the low pressure stage runner chamber, an exhaust passage from the high pressure stage runner chamber to the outside is formed in the main shaft, and the high pressure stage runner chamber and the low pressure stage runner chamber are connected to each other. A multi-stage hydraulic machine comprising a water distribution pipe that connects the return flow passage and a suction pipe connected to the low-pressure stage runner chamber. 2. An exhaust passage extending from the high pressure stage runner chamber to the outside is provided in a central portion of a main shaft, and an exhaust passage extending from the low pressure stage runner chamber to the outside is a concentric position or an eccentric position around the exhaust passage in the central portion. The multi-stage hydraulic machine according to claim 1, wherein the multi-stage hydraulic machine is provided. 3. A high-pressure stage to a low-pressure stage are connected by a series of return flow passages, and a main shaft sealing device is provided between the outer periphery of the main shaft above the high-pressure stage runner and a stationary part, and the main shaft penetrates the suction pipe. In a multi-stage hydraulic machine that is provided with a high pressure stage runner chamber and a low pressure stage runner chamber, and has a supply / discharge section for pressurized air for pushing down the water surface, a low pressure stage runner chamber is installed in the main shaft that penetrates through the suction pipe. From the low pressure stage runner chamber to an exhaust passage communicating with the low pressure stage runner chamber from the high pressure stage runner chamber. A return pipe that connects the runner chamber and the low-pressure stage runner chamber to each other and a suction pipe that connects the suction pipe that connects to the low-pressure stage runner chamber are provided. Water supply leading from outside A multi-stage hydraulic machine characterized by having a pipe.