JPS6147311B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic machine guide vane control device, and more particularly to a guide vane control device for a water turbine or a pump water turbine.

[Conventional technology]

In general, the closing time of the guide vanes of hydraulic machines is determined to suppress the increase in rotation to prevent damage to the rotating parts of the water turbine when the water turbine or pop-up water turbine is loaded or disconnected, and also to prevent damage to the water pipe. It is set to suppress the increase in water pressure as much as possible. However, in recent hydroelectric power plants, the water conductive pipes and water discharge pipes are relatively long due to location conditions, and closing control of the guide vanes becomes a problem. In other words, when the load on the water turbine or pump turbine is interrupted,
Since the rotational speed of the generator and water turbine rapidly increases and exceeds the permissible rotational speed, it is necessary to close the guide vanes in a short period of time. However, when the guide vane is suddenly closed, the water pressure inside the water pipe increases significantly, and in order to keep this water pressure below the allowable value,
The guide vanes must be closed slowly. Therefore, in order to satisfy these conflicting demands as much as possible, conventionally, a guide vane control device as shown in Figure 1 has been used to rapidly close the guide vanes to a certain opening to prevent the rotation of the generator and water turbine from increasing. At the same time, the guide vanes are closed at a slower closing speed midway through, controlling the water pressure inside the water pipe to below the allowable value.

In FIG. 1, when the pump-turbine is unloaded or unloaded, a close signal is input to the actuator solenoid 1 in response to the load unloading signal, and the valve spool 2 of the hydraulic distribution valve 3 is moved downward. Valve spool 2
When the servomotor hydraulic distribution valve 4 is moved downward, the pressure oil supplied to the servo motor hydraulic distribution valve 4 is drained to the hydraulic distribution valve 3 side through the pipe _l1 , and the hydraulic distribution valve 4 continues to flow until it comes into contact with the stopper 6. Valve spool 5 moves downward. When the valve spool 5 moves downward, the pressure oil P ₀ acting on the hydraulic distribution valve 4 is supplied to the guide vane operating servo motor 7 through the pipe l ₂ . As a result, the servo motor 7 is moved to the right in FIG. 1 by the pressure oil P ₀ supplied from the pipe l ₂ and operates to close the guide vane (not shown). When the guide vane closes to the specified position, the position detection switching valve 9 is switched by the molded cam 8. As a result, the pressure oil P ₀ being supplied to the position detection switching valve 9 is guided to the hydraulic switching valve 10 through the pipe l ₃ . The hydraulic switching valve 10 includes
Pressure oil P ₀ different from the pressure oil from pipe l ₃ is supplied, and when the hydraulic switching valve ₁₀ is operated by the pressure oil P 0 from pipe l ₃ , it is supplied to the hydraulic switching valve 10. The pressure oil P ₀ drives the throttle valve 11 to reduce the cross-sectional area of the oil drain pipe l 4 of the hydraulic distribution valve ₄ shown by the broken line, and adjust the closing speed of the guide vane servo motor 7 to a slower speed.

The opening degree of the guide vane that changes the closing speed and each closing speed of the guide vane are determined in consideration of the allowable rotation speed of the generator and water turbine and the allowable water pressure in the water pipe, as described above, and are determined by each power plant. It's different.

[Problem that the invention seeks to solve]

However, in the conventional guide vane control device for hydraulic machinery, in order to throttle the oil drain pipe l4 of the hydraulic distribution valve ₄ , a throttle valve 11 corresponding to the diameter of the oil drain pipe _l4 is required, and it is comparable to the hydraulic distribution valve 4. A large valve body is required. Moreover, when operating the throttle valve 11 with pressure oil from the position detection switching valve 9, the cylinder volume of the throttle valve 11 is large and the desired operating time cannot be obtained, so the hydraulic switching valve 10 is provided. The pressure oil P ₀ must be guided to the throttle valve 11 from another system, which makes the device expensive.

In addition, in pumped storage power plants equipped with pump turbines, the closing characteristics of the guide vanes are different during power generation operation and pumping operation, and a throttle valve corresponding to each must be installed in the drain pipe l of the hydraulic distribution valve 4. It was impossible.

The present invention has been made in order to eliminate the drawbacks of the prior art, and provides a guide vane control device for a hydraulic machine that can reduce costs by eliminating a throttle valve that throttles the drain pipe of a hydraulic distribution valve. The purpose is to

[Means for solving problems]

The present invention relates to a servo motor that operates a guide vane of a hydraulic machine, a hydraulic distribution valve that supplies driving pressure oil to the servo motor and controls the closing speed of the guide vane, and a pulse spool of the hydraulic distribution valve. and a stopper for controlling the amount of pressure oil supplied to the servo motor by changing the stop position of the servo motor. a first operating cylinder for controlling the spool via the stopper in a position to obtain a closing speed; and a first operating cylinder for controlling the spool through the stopper; Guide vane in position to obtain closing speed,
A second operating cylinder that controls the spool via the stopper, and a hydraulic circuit switching mechanism that selectively supplies pressurized oil to the first operating cylinder and the second operating cylinder. This is a guide vane control device for hydraulic machinery.

[Effect]

In the present invention configured as described above, the closing characteristic of the guide vane is controlled by operating the position of the valve spool of the hydraulic distribution valve that drives the servo motor that operates the guide vane, that is, by operating the hydraulic distribution valve itself. , the throttle valve installed in the oil drain pipe of the hydraulic distribution valve has been removed to reduce costs.

〔Example〕

Embodiments of a guide vane control device for a hydraulic machine according to the present invention will be described below with reference to FIGS. 2 and 3. The actuator solenoid 1 is a converter that converts an electric signal corresponding to the rotational speed of a water wheel or a pump water wheel into a mechanical signal, and opens and closes the hydraulic distribution valve 3. The hydraulic distribution valve 4 for the servo motor is
It has a valve spool 5 and an engaging piece 12, and the valve spool 5 and the engaging piece 12 are integrally constructed. Further, the hydraulic distribution valve 3 and the hydraulic distribution valve 4 are communicated with each other by a pipe _l1 , and when the valve spool 2 of the hydraulic distribution valve 3 is moved down, the hydraulic pressure distribution valve 4 is communicated with the hydraulic distributing valve 4 through the pipe _l1 . Pressure oil is drained to the hydraulic distribution valve 3 side. The hydraulic distribution valve 4 includes an oil drain pipe _l4 shown by a broken line. The hydraulic distribution valve 4 and the guide vane operating servo motor 7 are communicated by a pipe _l2 and a pipe _l3 . When pressure oil is supplied to the servo motor 7 from the pipe l ₂ , the servo motor 7 operates in the upper _right side of FIG. When supplied, the servo motor 7 operates on the left side in FIG. 2, that is, in the opening direction of the guide vane (not shown).

The molded cam 8 is for power generation operation, and the molded cam 1
4 is for pumping operation, and these molded cams 8,
14 performs an operation corresponding to the movement of the servo motor 7. The position detection switching valve 9 is for power generation operation and is communicated with the first operating cylinder 16 through a pipe _l5 . The position detection switching valve 15 is for pumping operation, and is communicated with the second operating cylinder 18 through a pipe _l6 . The position detection switching valve 9 moves the rod of the operating cylinder 16 upward or downward by supplying and discharging pressure oil to the pipe _l5 . On the other hand, position detection switching valve 1
5 moves the rod of the operating cylinder 18 upward or downward by supplying and discharging pressure oil to the pipe _l6 .

The solenoid valve 13 constitutes a hydraulic circuit switching mechanism, in which electromagnet A is energized during pumping operation, electromagnet B is energized during power generation operation, and the operation cylinder 17 connects the Ioki detection switching valve 9 and the position detection switching valve 15. It is connected by l ₇ l ₈ . This solenoid valve 13 is connected to pipe l ₇ and
By alternately supplying and discharging pressure oil to _l8 , the rod of the operating cylinder 17 is moved up or down.

The rods of the first and second operating cylinders 16 and 18 rotatably support points P ₁ and P ₃ at both ends of the lever 19, respectively. Point in the middle of lever 19
One end of the connecting member 20 is rotatably connected to P ₂ , and the other end of this continuous member 20 is rotated to point P ₄ at the tip of the lever 21 with point P ₅ as a rotation fulcrum. freely connected. A stopper 25 is formed on the lever 21 to restrict the amount of downward movement of the engaging piece 12 provided at the end of the valve spool 5.

The operation of the embodiment configured as described above is as follows.

In FIG. 2, during power generation operation, electromagnet B is excited and pressure oil P ₀ supplied to solenoid valve 13 is
l ₇ to the position detection switching valve 9, and is also guided to the operating cylinder 17, and the operating cylinder 1
It is pushing down the rod of 7. The rods of the operating cylinders 16 and 18 are also lowered,
The levers 19, 20 are in the positions shown by solid lines. During this power generation operation, when a load breakage signal is applied to the actuator solenoid 1, the valve spool 2 of the hydraulic distribution valve 3 moves downward. As a result, the pressure oil that was pushing up the valve spool 5 of the servo motor hydraulic distribution valve 4 is drained to the hydraulic distribution valve 3 side through the pipe _l1 . When the pressure oil acting on the hydraulic distribution valve 4 is drained, the valve spool 5 moves downward until the engaging piece 12 comes into contact with the stopper 25 provided on the lever 21 located at the position shown by the solid line, that is. , moves downward until the amount of movement reaches L ₁ . When the movement amount of the valve spool 5 reaches _L1 , the pressure oil _P0 supplied to the hydraulic distribution valve 4 is transferred to the servo motor ₇ via the pipe L2.
, the spool of the servo motor 7 is moved to the right in FIG. As a result, the guide vane (not shown) is closed at a predetermined closing speed, as shown by curve a in FIG. 4. In addition, the horizontal axis T in FIG. 4 is the elapsed time since the guide vane started closing, and the vertical axis GV is the opening degree of the guide vane.

When the guide vane reaches the bending point shown in curve a in FIG. Pressure oil P ₀
is supplied to the first operating cylinder 16 via pipe _l5 . As a result, the rod of the first operating cylinder 16 moves upward, and the lever 19 is rotated to the position shown by the two-dot chain line using the point _P3 as a pivot point. Therefore, point P ₄ at the end of lever 21 is
As it rotates in the counterclockwise direction, it is pushed up via the connecting member 20, and rotates counterclockwise about point _P5 as the rotation center, as shown by the two-dot chain line. When the lever 21 reaches the position shown by the two-dot chain line, the engagement piece 12 in contact with the stopper 25 is pushed up by the stopper 25 to a position lowered by _L2 from the normal operation. Therefore, the valve spool 5 integrated with the stopper 25 moves upward, reducing the amount of pressure oil P ₀ being supplied to the servo motor 7 via the pipe l ₂ . As a result, the movement of the spool of the servo motor 7 becomes gradual, and the closing speed of the guide vane reaches the fourth speed.
As shown in the figure, the curve becomes gentler than before the bending point of the curve a, and it is possible to prevent the water pressure in the water conduit from exceeding a permissible value. Note that the closing speed and bending point (opening degree of the guide vane) of these guide vanes are appropriately determined depending on the characteristics of the generator, the water turbine, the length of the water pipe, etc., as described above, and vary depending on the power generation plant.

On the other hand, during pumping operation, as shown in Figure 3,
The electromagnet A of the solenoid valve 13 is energized, and the pressure oil _P0 supplied to the solenoid valve 13 is supplied to the position detection switching valve 15 via the pipe _l8 , and is also supplied to the operating cylinder 17. Operation: Push up the rod of cylinder 17. The rod of the operation cylinder 17 pushes up the point _P2 of the lever 19 slightly, rotates the lever 19 slightly clockwise, and then releases the lever 19.
is held in the position shown by the solid line in FIG. and,
The lever 21 is connected to the lever 19 via the connecting member 20.
It has been rotated slightly counterclockwise and is at the position shown by the solid line. Therefore, the stopper 25 is located at a slightly higher position than during power generation operation, and the distance from the engagement piece 12 during steady operation is _L3 .

In such a state, when the pumping operation input/disconnection signal is input to the actuator solenoid 1, the pressure oil P ₀ that was pushing up the valve spool 5 of the hydraulic distribution valve 4 becomes hydraulic It is discharged to the distribution valve 3 side, the valve spool 5 moves down by _L3 , and the engagement piece 12 comes into contact with the stopper 25. Therefore, the servo motor 7 is supplied with pressure oil P ₀ from the hydraulic distribution valve 4 via the pipe l ₂ . However, since the amount of downward movement L ₃ of the valve spool 5 is smaller than the amount of downward movement L ₁ when the load is interrupted during power generation operation, the amount of pressure oil supplied to the servo motor 7 per unit time is Less than time. Therefore, the closing speed of the guide vane (not shown) is smaller than the closing speed of the unloaded guide vane, as shown by curve b in FIG. 4. This is different from water turbine operation (power generation operation) in the case of pumped storage operation.
No need to control rotation speed. This is based on the fact that it is only necessary to prevent pressure fluctuations that occur when water is turned on or off.

When the guide vane is closed along the curve b up to the bending point, the forming cam 14 actuated in response to the spool of the servo motor 7 switches the position detection switching valve 15 so that the pressure guided to the position detection switching valve 15 is reduced. Oil is supplied to the second operating cylinder 18. The pressure oil supplied to the second operating cylinder 18 pushes up the rod of this cylinder and rotates the lever 19 clockwise to the position shown by the two-dot chain line. This rotation of the lever 19 causes the lever 21 to rotate counterclockwise and reach the position shown by the two-dot chain line, causing the stopper 21 to rotate counterclockwise.
5 pushes up the engagement piece 12 to a position lowered by L ₄ than during normal operation. As a result, the valve spool 5 is pulled up slightly, reducing the amount of pressure oil being supplied to the servo motor 7 via the pipe _l2 . Therefore, the opening speed of the guide vane is determined by curve b in FIG.
It becomes more relaxed before the waist bends. The closing speed and bending point during these pumping operations are also appropriately determined depending on the characteristics of the pump-turbine.

As explained above, according to the present embodiment, the guide vane is closed by operating the pressure distribution valve 4 itself, so that the conventionally required expensive oil drain pipe for power generation operation and pumping operation is required. This eliminates the need for a restrictor valve, reducing equipment costs. In addition, since the closing speed of the guide vane is controlled by the pressure distribution valve 4, the closing speed can be easily adjusted.
A guide vane control device with high control accuracy can be obtained.

Furthermore, with the exception of the solenoid valve 13 that switches modes between power generation and pumping operation, everything is operated by hydraulic pressure, so even if a power loss accident occurs during power generation or pumping operation, the specified The guide vane closing feature allows the guide vane to be safely closed. In addition, when the bending points shown in FIG. 4 are set to two or three stages, this can be accommodated by adding a position detection switching valve and an operation cylinder, respectively.

Pumped storage power plants equipped with pump turbines utilize surplus electricity from thermal power during light loads such as late at night.
Water is pumped from the lower reservoir to the upper reservoir and stored, and the water stored in the upper reservoir is used to generate power during times of high load, so the water level in the upper reservoir fluctuates significantly. In addition, the runner of a pump-turbine has both the characteristics of a water turbine and a pump, and when the guide vane suddenly closes due to load interruption or sudden load reduction during power generation operation, the characteristics of the runner are affected. inducing abnormal water pressure pulsations. It is known that this water pressure pulsation is related to the water level (head) of the upper reservoir, and in order to suppress the water pressure pulsation, it is necessary to set the guide vane closing speed according to the water level of the upper reservoir. That is, the bending point of the guide vane closing speed needs to be set closer to the smaller opening as the head becomes larger. Therefore, in the case of power generation operation in a pumped storage power plant, the water level of the upper reservoir may be detected using a water level detection member, and the position detection switching valve 9 may be operated instead of the molded cam 8.

〔Effect of the invention〕

As explained above, according to the present invention, since the guide vane is closed by operating the hydraulic distribution valve itself, it is possible to eliminate the expensive throttle valve for restricting the oil drain pipe of the hydraulic distribution valve, which was required in the past. can.

[Brief explanation of the drawing]

FIG. 1 is a piping diagram showing a conventional guide vane control device for a hydraulic machine, FIGS. 2 and 3 are piping diagrams showing an embodiment of the guide vane control device for a hydraulic machine according to the present invention, and FIG. FIG. 3 is a diagram showing the closing characteristics of a guide vane servo motor according to an embodiment of the invention. 4... Hydraulic distribution valve for servo motor, 5... Valve spool, 7... Servo motor, 8... Molded cam for power generation operation, 13... Solenoid valve (hydraulic circuit switching mechanism), 14... Molded for pumping operation Cam, 16...first operating cylinder, 18...second operating cylinder, 19, 21...lever, 25...stopper.

Claims (1)

[Claims] 1: A servo motor that operates a guide vane of a hydraulic machine: A hydraulic distribution valve that supplies driving pressure oil to the servo motor and controls the closing speed of the guide vane: This hydraulic distribution valve a stopper for controlling the amount of pressure oil supplied to the servo motor by changing the stop position of the valve spool; and a stopper for controlling the amount of pressure oil supplied to the servo motor. a first operating cylinder for controlling the spool via the stopper to a position to obtain a predetermined guide vane closing speed; and: when the guide vane closes to a predetermined opening degree during pumping operation of the hydraulic machine. To,
a second operating cylinder for controlling the spool via the stopper to a position to obtain a predetermined guide vane closing speed; selectively supplying pressurized oil to the first operating cylinder and the second operating cylinder; A hydraulic machine guide vane control device comprising: a hydraulic circuit switching mechanism; and a hydraulic circuit switching mechanism.