JPS6225877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for idling a multistage hydraulic machine, and in particular, each stage from the highest pressure stage to the lowest pressure stage is connected by a return passage, and only the highest pressure stage The present invention relates to a method of operating a multistage hydraulic machine equipped with movable guide vanes when switching from power generation operation or pumping operation to idling operation in the power generation direction or pumping direction, respectively.

In general, in hydraulic machinery, water turbine power generation operation or
When switching from pump pumping operation to turbine control phase operation or pump pumping standby operation, in order to reduce the runner drive torque, the flow path is is driving the runner in the air by pushing down the water.

Among hydraulic machines, runner chambers of each stage are connected by return passages, and in the case of multi-stage hydraulic machines with complicated flow path shapes, when switching from power generation operation or pumping operation to respective idling operation, air supply,
Drainage tends to be accompanied by various problems.

In particular, in multi-stage hydraulic machines in which a movable guide vane is installed only in the highest pressure stage to safely control operating conditions during transient times, the flow paths of each stage from the highest pressure stage to the lowest pressure stage are constantly connected. Therefore, when high-pressure air is supplied to the flow path section, each step section tends to interfere with each other, making it difficult to smoothly supply and drain the air, and the air supply method has become a problem.

However, since there are many technologically unexplored fields in the multistage hydraulic machine itself, which has a movable guide vane only in the highest pressure stage, it is easy to use when switching from power generation operation or pumping operation to the required idling operation. The reality is that no accurate method for idling has yet been proposed.

Therefore, an object of the present invention is to make it possible to safely and reliably drain air supply and drain when switching from power generation operation or pumping operation to idling operation, and to enable a smooth transition to idling operation in a short time. The object of the present invention is to provide a method for operating a multi-stage hydraulic machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the first invention of the method for operating a multistage hydraulic machine of the present invention will be described with reference to the drawings.
Figure 1 shows a Francis type two-stage pump turbine as an example of a multi-stage hydraulic machine. Single pump turbine main shaft 1
A high-pressure stage runner 2 and a low-pressure stage runner 3 are fixedly spaced apart from each other on the axis. The high pressure stage runner 2 is surrounded by an upper cover 4 and a lower cover 5, while the low pressure stage runner 3 is surrounded by an upper cover 6.
and a lower cover 7, and a high pressure stage runner chamber 8
and a low pressure stage runner chamber 9. The high-pressure stage runner chamber 8 and the low-pressure stage runner 9 are connected by a return passage 10, and a return vane 11 and a stay vane 12 are provided on the passage.

Further, a spiral casing 13 is disposed outside the high-pressure stage runner chamber 8, and the inlet of the spiral chamber 14 is connected to a penstock 17 via an inlet valve 16. A movable guide vane 15 is provided on the outside of the high-pressure stage runner 2, and the opening degree of the guide vane can be adjusted by a guide vane operating mechanism (not shown). An elbow-shaped suction pipe 18 is connected to the low-pressure stage runner chamber 9, and its downstream side communicates with a discharge channel 20 via a suction pipe outlet valve 19.

A drain pipe 21 is provided on the outer periphery of the high pressure stage runner chamber 8.
On the other hand, a drain pipe 22 is connected to the outer periphery of the low pressure stage runner chamber 9, and drain valves 23 and 24 are installed on each pipe, and each drain pipe communicates with the suction pipe 18. ing. Further, an air supply pipe 25 is connected to the upper part of the suction pipe 18, an air supply valve 26 is installed on the pipe, and an air supply pipe 27 is connected to the return passage near the outlet of the high pressure stage runner 2. An air supply valve 28 is installed on the pipe. Furthermore, a water level detector 29 is installed above the suction pipe 18 to detect the water level in the suction pipe, and a pressure detector 30 is installed in the high pressure stage runner chamber 8 to detect the pressure inside the runner.

When operating the two-stage pump turbine configured as described above, the pressure sent from the penstock 17 through the opened inlet valve 16 flows into the spiral chamber 14 of the spiral casing 13, and this water flow The water passes through the movable guide vane 15 of the high-pressure stage section, flows through the high-pressure stage runner 2, the return passage 10, the low-pressure stage runner 3, passes through the suction pipe 18, and flows into the discharge channel 20.

On the other hand, during pump operation in which the runner rotates in the opposite direction at the same rotational speed as the water turbine, the water flow pumped up by the low-pressure stage runner 3 flows from the penstock through the penstock through the reverse route of the water turbine operation described above. 17
It will be distributed to.

Next, we will discuss an operation control method when applying the embodiment of the first invention of the present application to the above-mentioned two-stage pump turbine to shift from the turbine power generation operation or pump pumping operation to idling operation in the direction of the turbine or in the direction of the pump. state To shift from water turbine power generation operation or pump pumping operation to idling operation in the power generation direction or pumping direction, first fully close the high pressure stage movable guide vane 15 and the inlet valve 16 simultaneously or sequentially, and then When the vane 15 is fully closed or close to a small opening degree, the air supply valve 26 on the air supply pipe 25 connected to the upper part of the suction pipe 18 communicating with the lower part of the low pressure stage is opened, and air is supplied above the suction pipe part. and push the water level down to the specified position in the suction pipe (see Figure 1).

Next, when the water level has fallen to the specified position in the suction pipe section, the air supply valve 26 is closed to terminate the supply of air to the upper part of the suction pipe 18, and then it is connected to the return passage 10 near the outlet of the high-pressure stage runner 2. The air supply valve 28 on the air supply pipe 27 is opened to start supplying air to the return passage, and at the same time, the drain valve 24 is opened to drain the water remaining in the outer periphery of the low pressure stage runner chamber 9 and the return passage 10 to the low pressure stage drainage pipe. 22 into the suction pipe 18 (see FIG. 2).

Note that when the water level in the suction pipe reaches the specified position, it means that the water level in the suction pipe 18 is connected to the low pressure stage runner chamber 9.
The air supply valve 26 is closed based on this detection signal, and the air supply valve 28 and the drain valve are also closed. It is sufficient to open the valves of 24 respectively.

After that, when the pressure inside the high-pressure stage runner chamber 8 falls below the specified value, the drain valve 23 is opened and the water remaining in the outer periphery of the high-pressure stage runner chamber 8 is sucked out via the high-pressure stage drain pipe 21. 18, and the water surface in the suction pipe 18 is stabilized at the specified position by the force pushing down the water surface due to the high pressure air supplied to the return passage 10, and then the air supply valve 28 of the air supply pipe 27 is closed.
The supply of air into the return passage 10 is stopped and each runner is put into idle operation (see FIG. 3).

Note that the fact that the pressure in the high-pressure stage runner chamber 8 has reached a specified state can be detected by a pressure detector 28 provided in the runner chamber, and a detection signal from this pressure detector is transmitted to the drain valve 23. All you have to do is open the valve. Further, whether the water in the suction pipe 18 has stabilized at a specified water level is detected via a water level detector 29 provided at the upper part of the suction pipe, and the air supply valve 26 is closed based on this detection signal.

As is clear from the above description, according to the embodiment of the first invention of the present application, when first pushing down the water level in the inner flow path section of the high-pressure stepped movable guide vane, the high-pressure stepped movable guide vane is fully closed. Since air is supplied to the suction pipe section of the flow path of the two-stage pump-turbine, which is at the lowest pressure, an economical air supply device such as a compressor with a small pressure capacity can be used to cope with the problem, and air supply control is extremely efficient. It can be simplified, and in addition, since the supply air pressure is not applied directly to the runner, it is safe because it does not induce axial thrust that pushes the rotating part in the axial direction.

In addition, by supplying the compressed air, first, the water in the runner chamber of the low-pressure side stage is pushed down, and then air is supplied to the return passage, which is the high-pressure side stage above, where water still remains, and air is supplied to the high-pressure stage section. Since the outer periphery of the runner chamber, excluding the outer periphery of the runner chamber, is communicated with the suction pipe section via the drain pipe, the water remaining in the outer periphery of the low-pressure side step runner chamber and in the return passage connected upwards is absorbed by the centrifugal action of the runner. In addition to the drainage effect caused by force, the above-mentioned effect of pushing down the water surface by the air supply action from above allows water to be drained accurately from the runner room drain pipe in a very short period of time.

Note that the air supply to the return passage is carried out after the water in the runner chamber of the low-pressure side stage is pushed down to lower the pressure as described above, so the pressure capacity is small as in the case of air supply to the suction pipe section described above. Only one air supply device is needed,
Furthermore, since air supply pressure is not applied directly to the runner, no axial thrust is induced, as in the case of air supply to the suction pipe section.

Since the drainage area by compressed air is expanded from the low-pressure stage to the high-pressure side stage,
Unstable phenomena caused by mutual interference of water in each step during drainage can be avoided, allowing smooth drainage.

After supplying and draining air in this way, for the high-pressure stage runner chamber that is under the highest pressure among each flow path, the pressure in the high-pressure stage runner chamber is reduced to a safe specified pressure, and then the outer periphery of the runner chamber is Since the water stagnant in the runner chamber is discharged from the runner chamber drain pipe to the suction pipe section, water can be drained smoothly and accurately by the centrifugal force of the runner that is regulated to a safe pressure.

Next, the second method of operating a multi-stage hydraulic machine of the present invention will be described.
Examples of the invention will be described with reference to the drawings. In FIG. 1, which is the same as the embodiment of the first invention of the present application, a vent pipe 31 communicating with the atmosphere is installed above the swirl chamber 14 of the spiral casing 13, and a vent valve 32 is installed on the pipe. is incorporated. Furthermore, the casing swirl chamber 14 and the suction pipe 18
A casing drain pipe 33 is installed with a drain valve 34 installed on the pipe. The suction pipe 18 is provided with an external drain pipe 35 that communicates with a drainage pit (not shown) disposed outside and below the suction pipe 18 and communicating with the atmosphere, and a drain valve 36 is installed on the pipe. Other configurations are in the first part of this application.
This is the same as the embodiment of the invention.

The water turbine of the two-stage pump turbine configured in this way,
The movement of the water flow during pump operation is the same as in the above-described embodiment of the first invention of the present application.

Next, a method will be described in which the embodiment of the second invention of the present application is applied to this two-stage pump water turbine to shift from water turbine power generation operation or pump pumping operation to idling operation in the water wheel direction or pump direction.
First high pressure stage movable guide vane 15, inlet valve 1
The method from the closing operation of 6 to the state corresponding to FIG. 3 is the same as the embodiment of the first invention of the present application. That is, for the inner flow path portion of the fully closed guide vane 15, the water surface is pushed down by the air supply/drainage control according to the embodiment of the first invention of the present application, and then the vortex, which is the outer flow path portion of the movable guide vane 15, is pushed down. The water surface of the rolled casing 13 is pushed down as follows.

That is, in the idling operation state shown in FIG. At the same time, the casing drain valve 34 and the casing vent valve 32 are opened to allow the inside of the spiral casing 13 to communicate with the atmosphere through the ventilation pipe 31, and the water inside the spiral casing 13 is drained from the casing. The water is discharged by gravity flowing down into the suction pipe 18 through the drain pipe 33, thereby lowering the water level inside the spiral casing 13 (see FIG. 4).

The water remaining in one sealed space is first communicated with the lower atmospheric pressure part by opening the external drain valve 36, and then communicated with the lower atmospheric pressure part as the other end of the casing vent valve 32. Due to the opening,
These remaining waters are communicated with the upper atmospheric pressure area,
Due to the height difference between the atmospheric pressure water level at the end of the lower external drain pipe 35 and the position where the remaining water is located, the remaining water is discharged under atmospheric pressure.

The control valves of the casing drain valve 34, the casing vent valve 32, and the external drain valve 36 are as follows:
It is detected through a limit switch (not shown) that the suction pipe outlet valve 19 is fully closed, or a timer device (not shown) is preset to operate after the suction pipe outlet valve 19 is fully closed. )
The detection signal may be used to open each of the control valves simultaneously or sequentially.

As described above, according to the embodiment of the second invention of the present application, when pushing down the water surface of the spiral casing, which is the outer flow path section of the high-pressure step guide vane,
With the spiral casing ventilated with the atmosphere and no discharge channel pressure acting on the suction pipe, the water in the spiral casing is allowed to naturally flow down to the suction pipe through the casing drain pipe, so it is compressed into the spiral casing. A phenomenon in which water in the spiral casing is safely pushed down without any risk of air action, and water in the spiral casing leaks into the runners through the gaps in the movable guide vanes of the high-pressure step. As a result, economical idling operation with significantly reduced idling loss can be performed.

In addition, although the above-mentioned embodiments of the first and second inventions of the present application are applied to a two-stage pump turbine, the present invention can of course be applied to a multi-stage hydraulic machine with three or more stages. .

As described above, a runner is provided in each stage from the highest pressure stage to the lowest pressure stage, the runner chambers of each stage are connected by a return passage, and a movable guide vane is installed only in the highest pressure stage. According to the present invention, there is provided a method of idling operation that can be performed simply, quickly, accurately, and smoothly when a multi-stage hydraulic machine equipped with the above-mentioned system is shifted from power generation operation or pumping operation to idling operation in the direction of generation or pumping, respectively. This can be said to be extremely reasonable.

[Brief explanation of the drawing]

Figures 1 and 2 show air supply, drainage, and
A vertical cross-sectional view showing a state in the middle of operation, and FIGS. 3 and 4 are vertical cross-sectional views showing the pump-turbine in an idling operating state. 2... High pressure stage runner, 3... Low pressure stage runner, 8... High pressure stage runner chamber, 9... Low pressure stage runner chamber, 10... Return passage, 13... Spiral casing, 15... Movable guide vane, 16... Inlet valve, 18... Suction pipe, 19
... Suction pipe outlet valve, 21, 22, 33, 35... Drain pipe, 23, 24, 34, 36... Drain valve, 25,
27... Air supply pipe, 26, 28... Air supply valve, 31... Ventilation pipe, 32... Ventilation valve.

Claims (1)

[Claims] 1. A runner is provided in each stage from the highest pressure stage to the lowest pressure stage, the runner chambers of each stage are connected by a return passage, and a movable guide vane is provided only in the highest pressure stage. In the operating method of a multi-stage hydraulic machine equipped with a multi-stage hydraulic machine, when transitioning from water turbine power generation operation or pump pumping operation to power generation phase adjustment or pumping standby idle operation, the highest pressure stage is connected to the lowest pressure stage in a state where the highest pressure stage is connected to the lowest pressure stage. When the highest pressure stage guide vane is fully closed or close to a small opening, air is supplied to the upper part of the suction pipe connected to the lower part of the lowest pressure stage, and the suction pipe is closed. When the water level is pushed down to the specified position in the section, air supply to the upper part of the suction pipe section is terminated, and then air is sequentially supplied from the low pressure section side to the return passage section near the outlet of the high pressure stage runner, excluding the lowest pressure section. At the same time, the pressure in the highest pressure stage runner chamber is regulated while draining the water in the outer circumference of the low pressure stage runner chamber, excluding the highest pressure stage, from the low pressure stage side to the suction pipe section via the low pressure stage runner chamber outer circumference drain pipe. When the water level in the suction pipe section is stabilized at the specified position by draining the water in the outer peripheral part of the highest pressure stage runner chamber to the suction pipe section through the highest pressure stage runner chamber outer peripheral drain pipe, the water level is stabilized at the specified position. A method of operating a multi-stage hydraulic machine characterized by idling operation by terminating air supply to a return passage and pushing down water in a flow path from a highest pressure stage to a lowest pressure stage. 2 A multi-stage hydraulic machine equipped with a runner in each stage from the highest pressure stage to the lowest pressure stage, with the runner chambers of each stage connected by a return passage, and with a movable guide vane only in the highest pressure stage. In this operating method, when transitioning from turbine power generation operation or pump pumping operation to generation phase adjustment or pumping standby idle operation, the highest pressure stage side guide vane and inlet valve are connected to each other from the highest pressure stage section to the lowest pressure stage section. When the highest pressure stage guide vane is fully closed or close to a small opening, air is supplied to the upper part of the suction pipe connected to the lower part of the lowest pressure stage, and the water level is increased to the specified position of the suction pipe. The air supply to the upper part of the suction pipe is stopped when the pump is pressed down, and then air is sequentially supplied from the low pressure stage side to the return passage near the outlet of the high pressure stage runner, excluding the lowest pressure stage part, and the highest pressure stage part is The water in the outer periphery of the low pressure stage runner chamber, excluding the water, is sequentially discharged from the low pressure stage side through the drain pipe of the outer peripheral part of the low pressure stage runner chamber to the suction pipe section, and the pressure in the highest pressure stage runner chamber is brought to below the specified value. After the water on the outer periphery of the high pressure stage runner chamber is discharged to the suction pipe section through the drain pipe on the outer periphery of the highest pressure stage runner chamber and the water level in the suction pipe section is stabilized at the specified position, air is supplied to the return passage section as described above. completely close the suction pipe outlet valve provided in the suction pipe section or the draft tunnel section downstream thereof,
After that, the drain valve of the external drain pipe that connects the suction pipe and the drain pit arranged below the outside of the suction pipe and communicating with the atmosphere is opened to discharge the water in the suction pipe to the drain pit, and the water is opened at the top of the casing. While the vent valve of the vent pipe is opened and communicated with the atmosphere, the water in the casing between the fully closed inlet valve and the guide vane of the highest pressure stage is sucked out through the casing drain pipe and released by gravity to the pipe. A method of operating a multi-stage hydraulic machine characterized by idling operation by discharging the machine.