JPH0792044B2 - Guide vane control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide vane control device for a hydraulic machine equipped with a discharge valve, and more particularly to detecting a malfunction of the discharge valve and slowly closing the guide vane of the hydraulic machine. The present invention relates to a guide vane control device.

[Conventional technology]

The main function of the discharge valve is to bypass the flow regulating means of the water turbine such as the guide vane so that the water on the upstream side flows to the downstream side, but mainly when it is operated in conjunction with the hydroelectric power generation facility. Has the following purposes: (1) Use as a pressure suppressor to relieve the water hammer water pressure in the iron pipe by the water hammer phenomenon when the water turbine stops due to an accident (when the guide vane of the water turbine is suddenly closed). .

(2) Secure the amount of water discharged to the downstream side (the sum of the amount of water discharged from the turbine and the amount of water discharged from the discharge valve).

[Problems to be Solved by the Invention]

However, in a hydropower plant equipped with a discharge valve,
If the discharge valve cannot be opened while the guide vane is closed rapidly, the iron pipe connected to the turbine and the discharge valve will be damaged due to an abnormal increase in water pressure, and it will not be possible to secure the responsible discharge of water that should be flowed to the downstream side. The problem occurs. As a known example of this type of technique, the contents of Japanese Patent Laid-Open No. 52-134949 can be mentioned.

An object of the present invention is to provide a guide vane control device that can prevent an abnormal water pressure from being applied to the iron pipe and the guide vane even when the discharge valve is inoperative and that can secure the water discharge amount on the downstream side.

[Means for Solving the Problems]

The present invention relates to a guide vane control device including a discharge valve that adjusts the amount of water to a water turbine, a discharge valve servomotor that controls the discharge operation of the discharge valve, and a guide vane servomotor that controls the guide vane operation of the water turbine. , A simulated servo motor that moves up and down according to the opening / closing signal input to the discharge valve servo motor, a pressure distribution valve device that controls the operation of the guide vane servo motor, the simulated servo motor operation amount, and the discharge valve servo motor operation amount And a switching device that changes the pressure state of the pressure distribution valve device when the operation amount is different, and the guide vane servo motor when the operation amount of the simulated servo motor and the operation amount of the discharge valve servo motor are different. The movement of is switched from the sudden closing mode to the slowly closing mode.

[Action]

In this way, when the discharge valve does not open, by gently closing the guide vanes that are being closed rapidly, water is sequentially discharged from the guide vanes, so the water hammer phenomenon to the iron pipe and the guide vanes is gradually mitigated. The steel pipe and the guide vanes are less likely to be damaged by the water hammer due to the slow closing, and the mechanical strength of these can be lowered, so that not only is it economical, but the responsible water discharge to the downstream side can be secured. .

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a mechanism diagram in a neutral state of the release valve malfunction detection device, and FIG. 2 is a mechanism diagram in a state in which this device detects a malfunction error operation.

This embodiment includes a part for simulating the operation of an actual discharge valve servomotor (not shown), and a part for comparing the simulation result with the operation of the actual discharge valve servomotor, and using this comparison result. The state in which the guide vane is rapidly closed when the discharge valve is not opened is changed to the slowly closed state.

The part to be simulated is that the operating time of the lever 1 and the simulated servomotor 5 that transmits the same signal as the opening / closing signal to the actual release valve servomotor (hereinafter referred to as the main servo) is the actual operating time of the release valve servomotor. Adjustable diaphragms 2, 3 to make them the same
It is composed of a pilot valve 4 that opens and closes the simulated servomotor 5, and a simulated servomotor 5 that simulates the operation of the actual discharge valve main servomotor.

Although referred to herein as a simulated servomotor, its role is to provide a mechanism for simulating the operation of the normal release valve servomotor in response to the release valve servomotor opening / closing signal.

Further, for a mechanism that gives a discharge valve opening / closing signal, for example, when there is a large difference between the actual operating speed of the guide vane servomotor and the operating speed of the discharge valve servomotor (the signal input speed is higher than the response speed), When the discharge valve opening / closing signal and the feedback signal indicating the actual operation of the discharge valve main servo motor are directly compared, there is a possibility that the state in which the deviation signal amount is excessive is erroneously detected as a malfunction. . For this reason, in the embodiment of the present invention, a simulated servo motor is installed and the signal from this is used to prevent the deviation signal amount from becoming excessive.

When the discharge valve opening signal is input, the discharge valve signal lever 1 descends with the connection point immediately above the simulated servomotor 5 as a support. By this lowering operation, the plunger 4A of the pilot valve 4 is lowered, and the pressure oil P ₀ from the pressure oil tank is adjusted by the adjusting throttle 2
Is supplied to the pilot valve 4 through the pilot plunger 4A, the pressure oil P ₀ is injected into the lower side and the upper side of the simulated servomotor 5 from the pilot valve 4, and the pressure of the lower side having a large pressure oil area is supplied. As a result, the simulated piston 5A moves upward. As a result, when the simulated servomotor 5 reaches the opening required by the discharge valve opening signal, the pilot plunger 4A is returned to the neutral position and the opening operation of the simulated servomotor 5 is stopped.

Further, the portion comparing the simulation result with the operation of the discharge valve main servomotor includes a feedback shaft 9 that rotates according to the operation amount of the discharge valve main servomotor, a cam 8 that converts the rotation angle thereof into an up / down motion signal, and a discharge It is composed of a valve lever 7, a simulated servomotor 5, and a switching valve 6 having a switching valve plunger 6A that is moved by the discharge valve lever 7.

The operation of this mechanism is configured such that the operation amount of the simulated servo motor 5 and the amount of the open feedback signal from the discharge valve main servo motor are compared by the operation of the switching valve plunger 6A of the switching valve 6, so that the operation is normal. At this time, the switching valve plunger 6A always maintains the neutral position, so that the oil drain hole provided in the switching valve 6
6B is closed.

FIG. 2 shows a state in which this mechanism detects an erroneous non-opening operation. In this state, the switching valve plunger 6A is operated by the above-described operation of the simulated servomotor 5 (the feedback shaft 9, the cam 8, and the discharge valve lever). Since the open feedback signal from the main servomotor transmitted via 7 is not normal), it is moved upward from the neutral position and the oil drain hole 6B is opened. The pressure oil P ₀ is passed through the system and supplied to the pressure oil piston cylinder 13 shown in FIG.

FIG. 3 is a mechanism diagram showing an embodiment of the guide vane gradual closing switching mechanism.

The purpose of this mechanism is that if the discharge valve has the same iron pipe as the turbine, and if the discharge valve erroneously opens when the guide vane 17 of the turbine suddenly closes, it cannot function as a pressure suppressor. As indicated by the broken line, the iron pipe water pressure rises abnormally (the solid line indicates the case where the discharge valve is properly opened as a pressure suppressor). In order to prevent this abnormal rise, the guide vane 17 is configured to be slowly closed as shown by the alternate long and short dash line after the erroneous non-opening action is detected at point A in the figure.

That is, in FIG. 3, the solenoid valve for stopping the turbine operation during normal operation is shown.
Since the 65S side of 11 is energized and the pressure oil P ₀ from the pressure oil tank acts on the upper port of the hydraulic pressure switching valve 12, the hydraulic pressure switching valve 12 presses the lower spring as shown in the upper block in the figure. , The control pressure oil from, to the lower side of the pressure distribution valve piston 16 of the secondary pressure distribution valve 15 for the guide vane servomotor 17,
The guide vane servomotor 17 is operated by the control pressure oil from.

When the turbine sudden stop command is input, the 65T side of the solenoid valve is energized, resulting in the state shown in the figure, and the pressure oil above the switching valve 12 is
The oil is discharged through the block on the 65T side, and the pressure oil acting on the lower side of the pressure distribution valve piston 16 of the secondary pressure distribution valve 15 is discharged through the switching valve 12.

Therefore, the pressure distribution valve piston 16 descends to a position determined by the closing speed control mechanism 14 of the guide vane servomotor 17, and limits the oil passage area of the oil opening passage 18 and the oil closing passage 18A of the secondary pressure distributing valve 15. To do.

That is, if the erroneous non-opening operation is detected by the detector of the present invention at point a in FIG. 4, pressure oil will flow to the system in FIG. 2 (the same system in FIG. 3). Pressure oil acts on the lower chamber of the oil piston cylinder 13, and the pressure distribution valve piston 16 of the secondary pressure distribution valve 15 is pulled up, and the oil passage area of the oil passage 18 and the oil passage 18A is narrowed, and as a result, The operation time of the servo motor 7 is alleviated, and the mode shown by the alternate long and short dash line in FIG. 4 is achieved.

Reference numeral 13 in the drawing denotes a hydraulic piston cylinder, which houses the hydraulic piston therein, and when pressure oil is supplied, pushes up the hydraulic piston to raise the pressure distribution valve piston 16 to move both oil passages.
It serves to squeeze 18,18A.

〔The invention's effect〕

As described above, in the present invention, when the simulated plunger 5A is left open, the switching plunger 6A is raised and the oil drain hole
6B supplies pressure oil to the hydraulic piston cylinder 13, pushes up the pressure distribution valve piston 16 to reduce the oil passage area of the oil passages 18A, and the pressure oil in the oil passages is supplied to the guide vane servomotor 17. Therefore, the opening time of the guide vane servomotor 17 is switched from the sudden closing mode to the slow closing mode indicated by the alternate long and short dash line at the point a shown in FIG. For this reason, water is sequentially discharged, the water pressure of the iron pipe also becomes a one-dot chain line characteristic, and the water hammer phenomenon of the iron pipe can be prevented. As a result, it is possible not only to prevent damage but also to reduce the withstand voltage of these parts for designing, and to construct an economical power plant.

In addition, since the guide vanes are sequentially opened, water can be discharged downstream during this time, and the required amount of water can be secured.

[Brief description of drawings]

FIG. 1 is a mechanism diagram of an erroneous non-opening motion detector according to an embodiment of the present invention, FIG. 2 is a mechanism diagram showing the detection time of FIG. 1, FIG. 3 is a guide vane servomotor operating mechanism diagram, and FIG. The figure is a time chart of the present invention. 1 …… Release valve opening / closing signal lever, 2, 3 …… Adjusting diaphragm, 4 ……
Pilot valve, 5 ... Simulated servo motor, 6 ... Comparison switching valve, 7 ... Discharge valve lever, 8 ... Return signal cam, 9 ... Return shaft.

Claims (1)

[Claims] 1. A guide vane control device comprising a discharge valve for adjusting the amount of water to be supplied to a water turbine, a discharge valve servomotor for controlling the discharge valve, and a guide vane servomotor for controlling a guide vane of the water turbine. A simulated servo motor that moves up and down according to an opening / closing signal input to the discharge valve servo motor, a pressure distribution valve device that controls the operation of the guide vane servo motor, an operation amount of the simulated servo motor, and an operation of the discharge valve servo motor. And a switching device that changes the pressure state of the pressure distribution valve device when the operation amounts are different, and guides when the operation amount of the simulated servo motor and the operation amount of the discharge valve servo motor are different. A guide vane control device characterized in that the movement of a vane servomotor is shifted from a sudden closing mode to a slowly closing mode.