JP3299766B2 - Electric control device for water turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric control device for a water turbine in which a flow control valve such as a guide vane and a needle of a water turbine and an open / close control of a pressure suppressor are controlled by using an electric servomotor. The present invention relates to a water turbine electric control device that utilizes a self-closing force of a flow control valve as a part of a large control force required during operation.

[0002]

2. Description of the Related Art Generally, in a hydroelectric power plant, when an accident occurs in a power system to which output power of a generator is supplied,
The flow control valve of the turbine is rapidly closed to suppress an increase in the rotation speed of the turbine when the generator is disconnected from the power system. Then, since the flow of the pressurized water flowing into the hydraulic turbine from the flow control valve through the hydraulic pressure line is rapidly stopped, the water pressure in the hydraulic pressure line rapidly rises, and there is a fear that the hydraulic pressure line may be destroyed. . In order to prevent this, a pressure suppressor is installed in parallel with the inlet of the water turbine casing, and when the flow control valve is suddenly closed, it is opened and the pressure water in the hydraulic line is rapidly discharged, and the water pressure in the hydraulic line rises. Try to prevent.

[0003] In a conventional hydroelectric power plant, control of main components such as a flow control valve and a pressure suppressor of a water turbine has been performed by a hydraulic servomotor. Although not shown, the conventional pressure suppressor is provided in parallel with an inlet of a water turbine casing of a hydraulic line. A hydraulic servomotor for controlling the opening and closing of the flow control valve is built in, and a valve body is fitted and fixed to the opposite side of the piston rod to which the piston is fitted and fixed. Thus, the opening direction force acting on the valve body is supported and closed by hydraulic pressure acting on the closing side of the piston.

However, when the flow control valve of the water turbine is rapidly closed due to the above-described system accident, the operation rod mechanically connected to the flow control valve rapidly moves in the closing direction due to the closing operation, and the dashpot is closed. The pressure distribution valve of the hydraulic servomotor connected via the switch is switched to the open side. When the pressure distribution valve is switched to the open side, the closing pressure oil of the piston of the hydraulic servomotor is discharged, the piston rod moves in the opening direction due to the water pressure applied to the valve body of the pressure suppressor, and the valve body opens, and the pressure is released. Drainage of water is performed to suppress an increase in water pressure in the hydraulic pipeline. The cam mounted on the piston rod also moves in accordance with the movement of the valve body (piston rod) in the opening direction, and the movement of the cam lever following the movement of the cam causes the pressure distribution valve to be switched to the closed side and to be returned. Pressure oil is again supplied to the closed side of the piston, the valve body is closed against the pressure of the pressure water acting on the valve body, and the discharge of the pressure water is stopped. However, when the flow control valve is slowly closed, the operation of the pressure distribution valve is not performed by the action of the dashpot, the pressure suppressor does not operate, and the valve body does not open. As described above, since the pressure control device is controlled to be opened and closed by the hydraulic servomotor that is linked to the rapid closing of the flow control valve that is controlled to be opened and closed by the hydraulic servomotor, it functions as a safety valve for the hydraulic line of the hydroelectric power plant.

By the way, in recent hydroelectric power plants,
In consideration of river environment problems caused by leakage of pressurized oil, maintenance of equipment, etc., there is a tendency to eliminate all hydraulic oil equipment and hydraulic equipment and to use electric turbine-related control equipment. However, in terms of the function of the pressure suppressor, (1) the dead time generated between its own operation and the operation of the flow control valve of the water turbine is extremely small, and (2) the operation speed is equivalent to that of the electric servomotor. It is quick and (3) the required operating force itself is quite large. The three requirements are required, and it is difficult to satisfy the above three conditions simply by providing an electric servo motor dedicated to the pressure suppressor. However, it has been considered difficult to electrify the suppressor.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric motor of a water turbine capable of electrically controlling the opening and closing of a flow control valve including the control of a water pressure control device. It is to provide a control device.

[0007]

To achieve the above object, an electric control device for a water turbine according to the present invention comprises a first opening / closing mechanism connected to an operation rod of an electric servomotor, and
A self-closing type flow control valve for controlling the flow rate of pressurized water that is introduced into the water turbine through a hydraulic pressure line and rotates the water turbine runner, and is connected to the first opening / closing mechanism. a second opening and closing mechanism, a damper coupled to the second opening and closing mechanism provided in the penstock, this
A valve body with a built- in shock absorber.
A self-closing force is applied to the flow control valve, and when the flow control valve is rapidly closed, the valve body is rapidly opened to bypass the pressure water and discharge the pressure water.

[0008]

According to the present invention, a self-closing force applied to a flow control valve of a water turbine is utilized as a part of an operation force required for opening the water turbine of the water turbine provided with the pressure suppressor. Opening operation force can be greatly reduced,
It is possible to obtain a water turbine electric control device capable of controlling opening and closing of a flow control valve including a pressure control device with one electric servomotor.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of one embodiment in which the present invention is applied to a Pelton turbine, and a part is shown in a longitudinal sectional view. As shown in FIG. 1, the electric control device for a water turbine according to the present invention includes a Pelton water turbine 10, a pressure suppressor 11, an electric servomotor 12, and an opening / closing mechanism 13.

The Pelton turbine 10 is covered with a water turbine cover (not shown) and a disk 10c fitted and fixed to a horizontal shaft 10b.
Buckets 1 distributed evenly around the periphery of
0d constitutes the runner 10a, and jets into a plurality of buckets 10d as a jet from a nozzle (injection pipe) 10f formed at the tip of a tubular nozzle pipe 10e connected to a hydraulic line and curved in an inverted V-shape. Water is caused to collide, and a rotational force is applied to the runner 10a. Injection from the nozzle 10f is provided at the center of the nozzle pipe 10e, one end (right end in the figure) penetrates a curved portion of the nozzle pipe 10e, is connected to an opening / closing mechanism 13 described later, and a needle ( Needle valve) Needle rod 10h with 10g screwed forward / backward by opening / closing mechanism 13 (needle 10g forward / backward)
By doing so, the pressure water in the nozzle pipe 10e becomes a jet to increase or decrease the flow rate injected from the nozzle 10f, and the input to the Pelton turbine 10 is adjusted.

[0011] Suppression machine 11, Suppression machine cylinder 11b through the bypass pipe 11a is connected to the nozzle pipe 10e, the illustration below the Suppression machine cylinder 11b is connected the drain pipe 11c, drainage Suppression machine cylinder 11b Toko A valve seat 11d is formed on a side of the pressure suppressor body at a connection portion with the pipe 11c. In this valve seat 11d,
An opening / closing mechanism 13 to be described later penetrates through the pressure suppressor body 11b, and a lower end periphery of the pressure suppressor valve body 11e driven in the vertical direction in the drawing comes into contact with the opening / closing mechanism 13 and the self-closing by the water pressure of the pressurized water in the nozzle pipe 10e. Suppressor body 11b by force
Watertightness is maintained. The valve element 11e is a valve itself and is configured as a dashpot (buffer). Therefore, the valve element 11e has a buffer inside.
Cage, inside of its is divided into upper and lower chambers by a partition wall 11f, the lower chamber 11g constitute a dashpot cylinder,
A piston rod 11k is screwed into the piston 11h,
It is connected to the opening / closing mechanism 13 through the partition wall 11f and the upper wall 11m. The upper chamber 11n and the lower chamber 11g are filled with oil as shown in the drawing, the partition wall 11f is provided with a through hole 11o communicating between the chambers 11g and 11n, and the side wall of the valve body 11e is provided with the upper chamber 11n and the lower chamber 11n. A through hole 11p communicating with the lower part of the piston 11h in the chamber 11g is provided.

The electric servomotor 12 is a motor which operates as a prime mover, a reduction gear portion 12b for accommodating a reduction gear for reducing the rotation speed of the motor 12a, and a rotational movement of an output shaft of the reduction gear. A converter 12c for accommodating a converter for converting the motion is provided, and the whole is rotatably mounted on a fixed portion by a shaft 12e.

An opening / closing mechanism 13 is rotatably mounted on shafts 13a and 13b, respectively, and has first and second opening / closing mechanisms mainly composed of crank arms 13d and 13e each having one end connected by a connecting rod 13c. 13f and 13g. One end of the crank arm 13d is further connected to an operation rod 12d of the electric servomotor 12, and the other end is connected to one end of a needle rod 10h of the Pelton water turbine 10. One end of a piston rod 11k of the pressure suppressor 11 is connected to the other end of the crank arm 13e.

Next, the operation of this embodiment will be described.
FIG. 1 shows a stopped state of the Pelton turbine. However, during operation of the Pelton turbine, the needle rod 10h
Is driven in the upper right direction in the figure by the clockwise rotation of the crank arm 13d by driving the operation rod 12d rightward in the figure by the electric servomotor 12, and the nozzle 10f formed at the tip of the nozzle pipe 10e is opened. The pressure water in the nozzle pipe 10e is jetted as a jet, collides with the bucket 10d, rotates the runner 10a, and drives a generator (not shown).

In this state, for example, if any accident occurs in the power system to which the output power of the generator is supplied and the generator is disconnected from the power system, this is detected by a detector (not shown), In order to suppress an increase in the rotation speed, the electric servomotor 12 is provided with a needle 10 g of the Pelton turbine 10.
Is issued (rapid closing command). The electric servomotor 12 immediately responds to this, and its operating rod 12
d is rapidly driven in the direction of arrow 20 to rotate the crank arm 13d counterclockwise, and the needle 10g is driven in the lower left direction in the figure via the needle rod 10h to rapidly close the nozzle 10f, Block the jet of pressure water. Thus, the overspeed of the Pelton turbine 10 is prevented.

On the other hand, the operating rod 12d is rapidly moved by the arrow 20.
, The crank arm 13e also rotates counterclockwise via the connecting rod 13c, and rapidly moves the piston 11h together with the piston rod 11k of the pressure suppressor 11 as indicated by the arrow 2.
Drive in the direction of 1. Each of the upper and lower chambers 11n and 11g separated by the partition wall 11f of the pressure suppressor valve body 11e has a through hole 1
Although they are communicated by 1o and 11p, the upward movement of the piston rod 11k (piston 11h) is rapid, and the through holes 11o and 11p communicate between the upper and lower chambers.
Has a small cross-sectional area, the oil hardly moves between the upper and lower two chambers through the through holes 11o and 11p, and the oil is an incompressible fluid. Substantially one-piece. Accordingly, the pressure suppressor valve body 11e also moves upward following the upward movement of the piston rod 11k and opens the valve seat 11d.
Almost simultaneously with the closing of the nozzle 10f by 0 g, the pressure water in the nozzle pipe 10e starts to be discharged via the pressure control drainage pipe 11c. In other words, the pressurized water that has been jetted from the nozzle 10f as a jet is discharged from the pressure suppressor drainage pipe 11c almost simultaneously with the stop of the jet.
The water pressure in the nozzle pipe 10e does not rise rapidly,
There is no adverse effect on the hydraulic line such as the nozzle pipe 10e due to the sudden closing of the needle 10g.

As described above, when the pressure suppressor valve 11e moves upward and the pressure suppressor 11 is opened, the nozzle pipe 10
The pressure water in e passes through an annular gap formed between the lower outer peripheral surface of the pressure suppressor valve body 11e and the valve seat 11d and is discharged to the pressure suppressor drain pipe 11c. By the way, since a projection that performs a valve action by contacting the valve seat 11d is formed on the lower outer peripheral edge of the valve body 11e, the pressure water is discharged from the pressure suppressor body 11b to the drain pipe 11c. A force acting downward in the figure is always applied to the valve body 11e. And since the valve element 11e is a valve itself and is configured as a dashpot, when a downward force is applied to the valve element 11e, the oil in the lower chamber 11g passes through the through hole 11o by the action of the piston 11h. After moving to the upper chamber 11n, the same amount of oil as the oil that has moved to the upper chamber 11n passes through the through hole 11p and the piston 11 of the lower chamber 11g.
As the oil moves, the valve body 11e starts to descend, gradually descends and comes into contact with the valve seat 11d. During this time, the pressure suppressor 11 is gradually closed, the amount of discharged water gradually decreases, and finally stops, and a series of water turbine sudden stop control is completed. Therefore, even when the pressure suppressor 11 is automatically closed by the dashpot function of the pressure suppressor valve body 11e, there is no adverse effect on the hydraulic line.

Next, the nozzle 10f by the needle 10g
The operation output of the electric servomotor 12 required at the time of the quick closing control will be described with reference to FIG. In this case, since the needle 10g performs a quick closing operation, as described above,
It is considered that the built-in dashpot does not exist in the valve body 11e of the pressure suppressor 11, and the piston rod 11k is connected to the valve body 11e.
Description will be made assuming that it is fixed to e. FIG. 2 is a curve diagram showing a relationship between the opening degree (horizontal axis) of the needle 10g and the operation output (vertical axis) of the electric servomotor 12 required to open and close the needle 10g. Here, the curve (a) shows a value obtained by converting the self-closing force given from the pressure water of the needle 10g into the operation output of the electric servomotor 12, and the curve (b) opens the valve body 11e of the pressure suppressor 11. This shows a value obtained by converting the operation force required for the operation into the operation output of the electric servomotor 12. The direction of the operation output of the electric servomotor 12 when the needle 10g is rapidly closed via the opening / closing mechanism 13 having the configuration shown in FIG. 1 is in the direction of the arrow 20 and the self-closing force of the needle 10g. Of the valve body 11 of the pressure suppressor 11
The operating force when opening e is a force that opposes the self-closing force applied to the valve body 11e, the weight of the valve body 11e itself, and the sum of the frictional force between the valve body 11e and the pressure suppressor body 11b. ,
The magnitude of the operation output of the electric servomotor 12 required for rapidly closing the needle 10g is the difference between the curve (a) and the curve (b), and the value is a curve (c). That is, the curve (c) shows the opening of the needle 10g and the electric servomotor 12 when the needle 10g is closed rapidly.
Is a curve showing the relationship with the operation output.

The above is an explanation of the operation when a quick closing command is given to the needle 10g.
The normal closing operation (slow closing operation) of g will be described.
In this case, the operation rod 12d is gradually pulled in the direction of the arrow 20 by the gentle operation of the electric servomotor 12, so that the crank arm 13d slowly rotates counterclockwise, and the needle 10g also gradually lowers in the lower left of the figure. , The nozzle 10f is gradually closed to stop the jet flow to be injected. Similarly, the crank arm 13e also slowly rotates counterclockwise, and gradually pulls up the piston rod 11k (piston 11h) in the direction of the arrow 21. However, the lifting operation of the piston 11h is slow, and a downward force is applied to the valve body 11e by the pressure water in the pressure suppressor body 11b.
The oil above the piston 11h in the lower chamber 11g of the valve element 11e gradually moves to the upper chamber 11n through the through hole 11o in accordance with the upward movement of the valve body 11e, and the same amount of oil is transferred from the upper chamber 11n to the upper chamber 11n. Only by moving to the lower part of the piston 11h in the lower chamber 11g through the through hole 11p, the valve body 11e remains stationary and does not open the valve seat 11d. Needless to say, the magnitude of the downward force applied to the valve element 11e by the pressurized water can be adjusted by changing the shape of the valve element 11e.

The embodiment described above is the case where the present invention is applied to a Pelton turbine. However, the present invention is naturally applicable to not only the Pelton turbine but also various other turbines such as a Francis turbine. is there.

[0021]

As described above, according to the present invention,
Using the self-closing force applied to the flow control valve of the turbine as part of the operating force required when opening the pressure suppressor of a water turbine equipped with a pressure reducer, the opening operation force of the pressure reducer is significantly reduced So that one electric servomotor can control the opening and closing of the flow control valve including the pressure suppressor ,
Also, a valve body including a shock absorber connected to the second opening / closing mechanism.
Is installed in the hydraulic line, so that emergency water discharge response is quick.
Further, it is possible to provide a water turbine electric control device having a compact structure .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a curve diagram showing a relationship between an opening degree of a needle and an operation output of an electric servomotor required to open and close the needle.

[Explanation of symbols]

Reference Signs List 10: Pelton turbine, 10a: Turbine runner, 10g: Needle (flow control valve), 11: Suppressor, 11a: Side pipe, 11e: Valve body (buffer), 12: Electric servomotor, 12d: Operating rod, 13f 1st opening and closing mechanism, 1
3g: Second opening / closing mechanism.

Claims (1)

(57) [Claims] A first opening / closing mechanism connected to an operation rod of an electric servomotor; and a first opening / closing mechanism connected to the first opening / closing mechanism, the opening / closing of which is controlled, and introduced into a water turbine through a hydraulic line to rotate a water turbine runner. A self-closing type flow control valve for controlling the flow rate of pressurized water, a second opening / closing mechanism connected to the first opening / closing mechanism, and a buffer provided in the hydraulic line and connected to the second opening / closing mechanism And a valve body with the shock absorber inside, and the valve body always has a self-closing force with pressure water.
And a pressure control device for rapidly opening and closing the valve body when the flow control valve is rapidly closed to bypass and discharge the pressurized water.