JP3497574B2 - Hydraulic machinery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic machine such as a water turbine or a pump turbine that performs a runner idling operation during a phase-shifting operation or a start-up operation , and particularly to a runner during idling operation.
The present invention relates to a hydraulic machine that can effectively prevent air leakage from a room .

[0002]

2. Description of the Related Art For example, when a large-capacity large-capacity pump is started up, or when a power generation pump turbine or the like is subjected to a phase-matching operation to stabilize the power system, the flow of water into the pump or the pump turbine or the like is prevented. It is common to shut off and perform idling operation.

When performing such idling operation, the guide vanes arranged on the outer periphery of the runner are fully closed and high-pressure air is supplied to the runner chamber to push down the water surface of the upper suction pipe, The runner is rotating inside. By this idling operation, the starting torque of the runner and the driving torque at the time of acceleration are significantly reduced, and the shift to low speed operation is facilitated.

[0004]

FIG . 11 is a schematic illustration of the flow of a runner and a turbine chamber in a pump turbine. A runner 2 and a main shaft 3 are provided on the center side of the spiral casing 1, and guide vanes 4 are arranged on the outer peripheral portion of the runner 2 so as to be openable and closable. A curved pipe-shaped suction pipe 5 is connected to the outlet of the runner chamber 6a via an upper suction pipe 6b, and a water discharge passage 8 is connected to the outlet pipe. In such idling operation of the pump turbine, the runner 2 is in a shut-off operation state in which air is the working fluid.

That is, in the shutoff operation, the air is runner 2
Flows into the runner chamber 6a from the band side with a very strong turning force in the same rotation direction as the runner 2 from the band side. A similar circulating flow is also generated in the outer peripheral portion of the runner 2. Therefore, a swirling flow of air is generated in the runner chamber 6a and exerts a force on the pushing-down water surface 7.

When the suction height is low and the air pressure required for pushing down is about atmospheric pressure, the density difference between air and water is so large that the force acting on the pushing down water surface 7 is small and the pushing down water surface 7 is 2 shows sloshing-like oscillation accompanied by rotation in the same direction as 2, and the turbulence of water in the upper suction pipe 6b is small.

However, in a large-capacity pump turbine, the suction height is increased in order to avoid cavitation generated in the runner 2 during pump operation, and the air pressure required to push down the water surface reaches several to several tens of atmospheres.

For this reason, the increase in the density of air has a great influence on the push-down water surface 7, and at an air pressure of 2 to 3 atmospheres or more, the push-down water surface is crushed and the water in the upper suction pipe 6b is also greatly disturbed. In this case, conventionally, since the entire upper suction pipe 6b has a circular sectional shape, the resistance to the swirling flow is relatively small, and the air swirls violently.

Along with this, air bubbles are entrained in the pushed water. A part of the air entrained in the water flows out into the water discharge passage 8 downstream of the suction pipe 5, and the air in the runner chamber 6a decreases with the lapse of operating time.
That is, since the movement of the push-down water surface 7 increases due to the increase in the push-down air pressure and the outlet peripheral speed of the runner 2,
It is caught in water and flows out to the discharge channel 8.

As a result, the push-down water surface 7 below the runner chamber 6a gradually rises, and due to the interference between the runner 2 and the push-down water surface 7, vibration, torque fluctuation, temperature rise of the runner 2, etc. occur.

It is necessary to constantly supply a large amount of high-pressure air to the runner chamber 6a in order to maintain the push-down water surface 7 properly, avoid the interference between the runner 2 and the push-down water surface 7, and continue the idling operation. Becomes As a measure to reduce the leakage of air to the downstream side of the suction pipe 5, the upper suction pipe 6b is lengthened so that the distance between the lower end of the runner 2 and the pushing water surface 7 and the upper edge of the bent portion of the suction pipe 5 from the pushing water surface 7 It is known to increase the distance to.

However, in the above method, the amount of excavation work for burying the suction pipe is large, and the height of the suction pipe is also increased, so that the construction cost of the power plant is inevitably increased. Also, as the capacity and speed of pump turbines increase, the pushing air pressure and the peripheral speed at the runner outlet increase, so that the suction pipe will be increasingly used to prevent air leakage to the downstream side of the suction pipe during idling operation. It is necessary to increase the height.

The present invention has been made in view of the above circumstances, and it is possible to effectively prevent air leakage from the runner chamber during runner idle operation of a hydraulic machine such as a water turbine or a pump turbine, and to reduce the construction cost. Providing a hydraulic machine that enables stable and reliable idling operation without increasing
An object of the present invention is to today.

[0014]

In order to achieve the above-mentioned object, the invention according to claim 1 is a hydraulic machine in which a runner chamber is filled with air during a phase-shifting operation or a start-up operation and the runner runs idle. in between a position higher than the pressing surface of the water which definitive in depressed water surface near the position of the upper draft tube in the circumferential direction
Multiple flow restrictions that are installed separately and regulate the air flow
During the idling operation, the blade is connected to the flow regulation blade.
In the upper suction pipe, the facing angles of the plurality of flow regulating vanes are
Regulation to control the swirl flow generated inside
A blade control device is provided .

According to a second aspect of the present invention, during the phase-matching operation or
Fill the runner room with air during start-up operation, etc.
In hydraulic machinery to drive, spacing manner to the pressing surface of the water bottom to definitive the depressed water surface near the position of the upper draft tube in the circumferential direction
A plurality of flow regulation blades that are provided in the and regulate the flow of water
And is connected to the flow restricting blades,
Note that the facing angles of a plurality of flow restriction blades should be in the upper suction pipe.
Control blades that control the swirling flow to be positive
A root controller is provided.

[0016]

According to the first aspect of the invention, the flow restricting blade is provided.
It is arranged above the surface of the water to be pushed down, and its flow regulation
The angle of attack of the control blades with respect to the swirling flow along the direction of rotation of the runner
Since it was controlled to be negative,
The swirling flow of air causes water to flow along the negative angle of attack of the flow regulation blade.
It is controlled as a flow that is higher than the surface, and the swirling flow is pushed.
Since it is blocked against the surface of the lowered water, it suppresses the rocking of the pressed water surface.
Can be controlled. Therefore, it is possible to prevent a large turbulence of the air flow, a vibration of the flow regulating blade, a rocking of the water surface, and the like.

It is not preferable that the angle at which the swirling flow of the flow regulating blade reaches (the angle of attack) is too large, because a large turbulence of the air flow is generated and the flow regulating blade also vibrates. Further, when the angle of attack is made positive, the air flow pushes down and accelerates the water surface swing.

According to the second aspect of the invention, the flow restricting blade
The roots are pushed down and placed below the water surface.
The angle of attack of the control blade is changed to a swirling flow along the direction of rotation of the runner.
Since I tried to control it positively,
The swirling flow of the generated water follows the positive angle of attack of the flow control blade.
Pressed because the flow is controlled to go below the water surface
It is possible to suppress rocking of the water surface. Therefore, it is possible to prevent a large turbulence of the air flow, a vibration of the flow regulating blade, a rocking of the water surface, and the like.

[0019]

EXAMPLE An example of a hydraulic machine according to the present invention will be described below with reference to FIG.
~ It demonstrates with reference to FIG . Note that this embodiment is applied to a pump turbine, and the same reference numerals are used for parts common to or corresponding to those in FIG. 11 .

1 to 10 show an embodiment of the present invention. 1 and 2 are cross-sectional views of a main part, FIG. 3 is an overall cross-sectional view, and FIGS. 4 to 10 are operation explanatory views.

In the pump turbine of this embodiment, as shown in FIG. 3, a runner 2 and a main shaft 3 are provided on the center side of a spiral casing 1, and guide vanes 4 are arranged on the outer peripheral portion of the runner 2 so as to be openable and closable. There is. A curved pipe-shaped suction pipe 5 is connected to the outlet of the runner chamber 6a via an upper suction pipe 6b, and a water discharge passage 8 is connected to the outlet pipe.

In this case, as shown in FIGS. 1 and 2, the upper suction pipe 6b is provided at a position in the vicinity of the pressing water surface 7.
A plurality of flow regulation blades 9 that regulate the flow of air or water are provided at intervals in the circumferential direction. These flow restricting blades 9 are supported so that they can form an arbitrary angle with respect to the flow direction of water or air in the suction pipe 5. A restricting blade control device 10 for attitude control is connected to each of the flow restricting blades 9 and is located on the outer peripheral side of the upper suction pipe 5.

The operation of this embodiment having such a configuration will be described below.

The guide vane 4 is closed and the runner chamber 6a is closed.
When the water surface inside is pushed down, a control signal is sent from the computer in the central control room (not shown) to the regulation blade control device 10, and the attitude of the flow regulation blade 9 is controlled.

The attitude of the flow restricting blade 9 is controlled according to the rotation direction of the runner 2, and as shown in FIGS. 4 and 5, the flow restricting blade 9 reaches the swirling flow of air generated by the runner 2. The attitude is controlled so that the angle α becomes negative, and the rotation of the runner 2 is started.

As the rotation speed of the runner 2 increases, a swirling flow of air is generated and flows out along the outer circumference of the suction pipe 5. In this case, in this embodiment, the swirling flow is blocked by the flow restricting blade 9, so that the push-down water surface 7 does not swing.

The fact that the angle of attack α rises too much is shown in FIG.
As shown in (1), a large turbulence of the air flow is generated, and vibration is also generated in the flow regulating blade 9, which is not preferable. Further, if the angle of attack α is made positive, as shown in FIG. 7, the air flow promotes the rocking of the water surface toward the pushed-down water surface 7.

When the idling operation is completed and the pump operation or the water turbine operation is started, the flow restricting blade 9 is changed to a posture along the water flow as shown in FIG. In this case, since the flow restricting blade 9 is along the direction of the water flow, the efficiency is not significantly reduced.

According to the above-described embodiment, when the hydraulic machine such as a pump turbine having a large capacity and a high head has idle operation, the pushing water surface is prevented from rocking. The suction pipe 5 is designed not only to prevent leakage but also to reduce the capacity of the compressor for supplying air for pushing down the water surface, and also to prevent leakage of air.
It is not necessary to take the height of the
It will also be possible to effectively reduce the construction cost of the power plant.

In the above embodiment, the flow restricting blade 9 is set at a position higher than the push-down water surface 7. However, as shown in FIG. 9, the flow restricting blade 9 is provided in the water close to the push-down water surface 7. Is also possible. In this case, although the water surface slightly fluctuates, the angle of attack α becomes positive with respect to the swirling water flow in the upper suction pipe 6b caused by the swirling flow of air, contrary to the case where the flow restricting blade 9 is in air. It is desirable to control as follows. As a result, for example, as shown in FIG. 10, the water on the surface is not scattered, and the scattered water does not interfere with the runner, and the water surface fluctuation can be reduced.

[0031]

As described above in detail, according to the present invention, it is possible to suppress the rocking of the pushing down water surface during idling operation of a hydraulic machine such as a large capacity high head pump or a pump turbine. It is possible to prevent or reduce the leakage of the pushing air due to the swing of the pushing water surface. Moreover, it is possible to reduce the capacity of the compressor for supplying the water-pushing air, and it is not necessary to increase the height of the suction pipe only for the purpose of preventing air leakage, which reduces the cost of construction of a power plant such as the amount of excavated civil engineering. The reduction can be effectively achieved. Therefore, according to the present invention, it is possible to prevent leakage of air from the runner chamber during a runner idle operation such as a phase-changing operation or a start-up operation of a hydraulic machine, and to perform a stable and highly reliable operation, while reducing the construction cost. It has excellent effects such as

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of a slipping operation device for a hydraulic machine according to the present invention.

FIG. 2 is a vertical cross-sectional view of the central portion of FIG.

FIG. 3 is a sectional view showing the overall configuration of the embodiment.

FIG. 4 is an explanatory view of the operation of the above embodiment.

FIG. 5 is an explanatory view of the operation of the above embodiment.

FIG. 6 is an explanatory view of the operation of the above embodiment.

FIG. 7 is an explanatory view of the operation of the above embodiment.

FIG. 8 is an explanatory view of the operation of the above embodiment.

FIG. 9 is an explanatory diagram showing a modified example of the embodiment.

10 is a comparative explanatory diagram corresponding to FIG. 9. FIG.

FIG. 11 The whole block diagram which shows a prior art example.

[Explanation of symbols]

1 spiral casing 2 runners 3 spindles 4 guide vanes 5 Suction tube 6a runner room 6b Upper suction pipe 7 Depressed water surface 8 spillway 9 Flow control blade 10 Restriction blade control device α angle of attack

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F03B 15/04 F03B 11/00 F03B 15/14

Claims (2)

(57) [Claims] 1. In a hydraulic machine in which the runner chamber is filled with air and the runner runs idle during phase-shifting operation or start-up operation, etc., at a position higher than the pressing surface of water in the vicinity of the pressing surface of the upper suction pipe. A plurality of flow restricting blades that are provided at intervals in the circumferential direction and that restrict the flow of air, and are connected to the flow restricting blades, and the heading angle of the plurality of flow restricting blades in the upper suction pipe during the idling operation. A hydraulic machine, comprising: a regulating blade control device that controls the swirling flow to be negative. 2. A runner during phase-shifting operation or start-up operation
In a hydraulic machine where the chamber is filled with air and the runner runs idle, the upper suction pipe
Around the push-down water surface
, Which are provided at intervals in the direction to regulate the flow of water.
Control blade and the flow control blade,
During operation, the heading angle of the plurality of flow restriction blades is adjusted to the upper suction
Control to be positive with respect to the swirling flow generated in the outlet pipe
Regulating blade control device for
machine.