JPH0138190B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention provides a pressure suppressor whose opening is controlled via a link mechanism by a dart pot servo motor that is inserted into a bypass path for water turbine flow and whose position can be controlled hydraulically. A guide vane servo motor that controls the flow of water to the water turbine is linked to the intermediate point of the link mechanism, and the water turbine is normally operated while keeping the suppressor closed, and when the water turbine is in governor-free operation, the guide vane servo motor is linked to the intermediate point of the link mechanism. The present invention relates to a water turbine control device that can control the opening of a pressure suppressor by controlling the position of a shovel pot servo motor.

[Prior art and its problems]

In a water turbine power plant, a normal water penstock is installed to guide a large amount of pressurized water, which is an energy medium, and a pressure suppressor is inserted into the bypass path of the penstock, and when the guide vane suddenly closes the water inlet, it opens suddenly to reduce the water pressure. This prevents pressure from rising inside the iron pipe. However, if the guide vane suddenly closes when there is a problem with the opening operation of the pressure suppressor, water hammer action will induce an unacceptable increase in water pressure inside the penstock, so the guide vane should be closed for a longer time to increase the water pressure. It is desired to prevent this.

[Purpose of the invention]

In view of the above points, the present invention is a water turbine that enables load-restricted operation and governor-free operation, and that can prevent water pressure from increasing in the penstock with a simple control device when a problem occurs in the opening operation of the pressure regulator. The purpose is to provide a control device for.

[Key points of the invention]

According to the present invention, the above-mentioned object is provided with a pressure suppressor whose opening degree is controlled via a link mechanism by a dart pot servo motor that is inserted into a bypass path for water turbine flow and whose position can be controlled by hydraulic pressure, A guide vane servo motor that drives a guide vane that controls the flow of water to the water turbine is linked to the intermediate point, and the suppressor is normally closed, and the opening of the suppressor is adjusted during governor free operation. a hydraulic control circuit for controlling the hydraulic pressure supplied to the dart pot servo motor so as to control the hydraulic pressure supplied to the dart pot servo motor, and a pressure control circuit for driving the suppressor in the opening direction in conjunction with the closing operation of the guide vane by the guide vane servo motor when the load is cut off. a dartpot servo motor locking means for locking the dartpot servo motor in that position by blocking its opening/closing hydraulic ports; and an abnormality detection means for monitoring the opening operation of the pressure suppressor and generating a detection output in the event of an abnormality; This can be achieved by providing operation speed suppressing means that switches the operating speed of the guide vane servo motor based on the detection output of the abnormality detecting means and suppresses the speed of the closing operation of the guide vane to a low speed.

[Embodiments of the invention]

The present invention will be described in detail below based on drawings showing embodiments. The figure is a system diagram of the main parts of a water turbine showing an embodiment of the present invention. When the pressure suppressor does not operate due to an abnormality during operation of the water turbine, a pressure detector as an abnormality detection means detects the pressure increase of the dumppot servo motor. This system detects an abnormality and instructs the guide vane servo motor to change its operating time, increasing the operating time of the guide vane servo motor to gradually close the guide vane and prevent water pressure from rising inside the penstock. This is what I did. First, the configuration of the water turbine operation control system will be explained based on the drawings. In the figure, 1 indicates the water conduit to the water turbine, 1a indicates the runner, and the control system of the guide vane servo motor 20 that operates the opening and closing of the guide vane 2, and the control system of the dart pot servo motor 40 that operates the opening and closing of the suppressor 4. The guide vane 2 is pin-coupled to a guide vane servo motor 20 via a link mechanism 3, and the suppressor 4 is pin-coupled to a dart pot servo motor 40 via one link 5. Further, the dart pot servo motor 40 is pin-coupled to the guide vane servo motor 20 via a link mechanism 6 at an approximately intermediate position of the link 5.

The control system of the guide vane servo motor 20 includes:
A governor 21, a pressure distribution valve 22, and an attached pressure oil pipeline are provided, and pressure oil is supplied to the pressure distribution valve 22 through the supply pipeline 2.
Supplied from 3. This pressure distribution valve 22 is connected to the governor 21
When the pressure oil flows through the pipe 23 in the direction of arrow A, the piston 20a of the guide vane servo motor 20 moves in the direction of arrow B, operating the guide vane 2 in the opening direction, and opening the pipe 24 side. The pressure oil that flows through the pressure distribution valve 22 is collected into the oil collection tank 25. Also, contrary to the above, when pressure oil flows from the pressure distribution valve 22 into the pipe line 24 as shown by arrow C, the piston 20a of the guide vane servo motor 20 moves as shown by arrow D to operate the guide vane 2 in the closing direction. However, the pressure oil flowing through the pipe line 23 is collected into an oil collection tank 26 via a pressure distribution valve 22. A throttle valve 27 is provided in a conduit 26a between the oil collection tank 26 and the pressure distribution valve 22. It is controlled so that it can move forward and backward.

The control system of the dart pot servo motor 40 is provided with solenoid valves 41, 42, 43 and an attached pressure oil pipeline. When pressure oil flows through the pipe 44 in the direction of arrow E, the piston 40 of the dart pot servo motor 40 is controlled by the valve.
a moves in the direction of arrow G to open the suppressor 4,
When the pressure oil flows through the pipe 45 in the direction of arrow F, the piston 40a of the dart pot servo motor 40 moves to H.
direction, and the suppressor 4 is operated in the closing direction. Reference numeral 46 denotes a pressure oil supply conduit, and a solenoid valve 42 is provided in this pressure oil supply conduit 46 . Further, 47 is a pressure oil discharge pipe, and this discharge pipe 47
A solenoid valve 43 is provided inside. In addition, 31 is a slow return valve, 32 is a safety valve, 33 is an oil bed tank, 34 is a filter, 35 is a check valve,
Reference numeral 36 indicates an operating valve, 44a a pressure gauge for the pipe line 44, 44b a pressure detector for the pipe line 44, 45a a pressure gauge for the pipe line 45, and 48 an operating valve.

Next, the operation of the control device configured as above will be explained.

During load limiting operation, the guide vane 2 gradually opens and closes in accordance with the operation of a load limiting operation device (not shown), and the pressure suppressor 4 remains fully closed to suppress ineffective discharge. In this case, all of the solenoid valves 41, 42, and 43 are in a non-excited state as shown in the figure. The pressure oil supplied from the pressure oil supply pipe 46 is supplied to the solenoid valves 42 and 41.
The piston 40a of the dart pot servo motor moves as shown by the arrow H, and the pressure suppressor 4 connects the link 5 and the link mechanism 6. It is held closed using the pin 50 at the connection point as a fulcrum. When the guide vane servo motor 20 is operated with a limited load and the guide vane 2 gradually opens and closes, the link 6a of the link mechanism 6 moves, and in the case of opening, the link 6a moves in the direction of arrow 51. That is, the hydraulic force on the guide vane servo motor 20 side is slightly larger than the hydraulic force on the dartspot servo motor 40 side, and
The piston 40a moves together with the link 5 in the direction of the arrow G to open the guide vane 2, but the pressure suppressor 4 remains fully closed.

When the load is interrupted, the solenoid valves 42 and 43 are energized.
The opening/closing ports of the dart-pot servo motor 40 are locked by electromagnetic valves 42 and 43, and the piston 40a of the dart-pot servo motor 40 is at an intermediate position corresponding to the opening degree of the guide vane 2 when the load is cut off. is retained. Then, when the guide vane 2 suddenly closes, the pressure suppressor 4 is opened by the hydraulic force of the guide vane servo motor 20.

When the pressure suppressor 4 is not operating, the solenoid valve 42 is excited in the direction of the arrow 52, so that the pressure of the hydraulic pressure operating the pressure suppressor 4 of the dart pot servo motor 40 in the opening direction, that is, the pipe line 44 The internal pressure rises due to the addition of hydraulic force that causes the guide vane servo motor 20 to move in the direction of arrow D. The pressure detector 44b detects a pressure increase value exceeding this predetermined value and is activated, and the solenoid valve 29 of the control system on the guide vane servo motor 20 side is energized and enters the state shown in the figure, and the pressure oil flows from the solenoid valve 29 to the arrow 53. It flows in the direction of the view, and the throttle valve 27 operates in the direction of the arrow 54. at the same time,
The solenoid valves 42 and 43 of the control system of the dart pot servo motor 40 are in a non-excited state, and the piston 40a of the dart pot servo motor 40 is connected to the pressure regulator 4.
is controlled in the closing direction. On the other hand, the pressure oil in the pressure distribution valve 22 flows through the pipe line 24 as shown by arrow C, and the piston 20a of the guide vane servo motor 20 moves as shown by arrow D to operate the guide vane 2 in the closing direction.
The pressure oil flowing through the pipe line 23 side passes through the pressure distribution valve 22 and flows through the pipe line 26a, and the outflow flow rate in the pipe line 26a is controlled by the throttle valve 27, so the operating time of the guide vane servo motor 20 is shortened. The guide vane 2 can be gently closed to prevent water pressure from rising inside the penstock.

During governor free operation, the solenoid valves 41, 42, 43 are controlled by an opening setting device (not shown), and the solenoid valves 42, 43 are excited. The dart pot servo motor 40 has opening/closing ports connected to solenoid valves 42 and 4.
3, and the piston 40a of the dart pot servo motor 40 is held at the intermediate position set by the opening setting device. Guide vane 2
With the sudden closing and opening of the pressure suppressor 4, the pressure suppressor 4 suddenly opens and closes using the pin 50 as a fulcrum, and the guide vane 2 and the pressure suppressor 4 are in a synchronous operation state, and the pressure from the guide vane 2 and the pressure suppressor 4 is The sum of the discharged water is kept constant.

When the controller 4 is not operating, the solenoid valve 42 is energized in the direction of arrow 52, as shown in the above embodiment, so the pressure regulator 4 of the dart pot servo motor 40 is operated in the opening direction. It is activated when the hydraulic pressure, that is, the pressure in the pipe line 44 increases, and the pressure detector 44b detects a pressure value exceeding this predetermined value,
The solenoid valve 29 of the control system of the guide vane servo motor 20 is excited. The throttle valve 37 operates in the direction of arrow 54 to control the outflow flow rate in the pipe line 26a, and the operating time of the guide vane servo motor 20 becomes longer, causing the guide vane 2 to operate slowly and increase the water pressure in the penstock. It can be prevented.

When the water turbine operation is stopped and the pressure suppressor 4 is opened and closed to secure the flow rate downstream of the power plant, a pressure suppressor bypass operation can be performed. In this case, the guide vane 2 is locked in the fully closed state. Excite the solenoid valve 41 of the control system of the dart pot servo motor 40,
When the solenoid valves 42 and 43 are de-energized, pressure oil flows through the pipe 44 as shown by arrow E and enters the dart pot servo motor 40, and the piston 40a of the dart pot servo motor moves as shown by arrow G. The suppressor 4 opens using the pin 50 as a fulcrum. Furthermore, when all the solenoid valves 41, 42, and 43 are de-energized, the pressure oil flows through the pipe 45 as shown by the arrow F and enters the dart pot servo motor 40, and the piston 40a of the dart pot servo motor moves as shown by the arrow F. It moves like H and the suppressor closes.

〔Effect of the invention〕

As described above, the present invention includes a pressure suppressor that is inserted into a bypass path for water turbine flow and whose opening is controlled via a link mechanism by a dart pot servo motor whose hydraulic position can be controlled. By linking the guide vane servo motor controlled by the servo motor and installing a pressure detector in the hydraulic control system of the dart pot servo motor, load limiting operation, governor free operation, and pressure regulator bypass operation are possible. Therefore, it is possible to provide a control device for a water turbine that can prevent an increase in water pressure in a penstock by detecting inoperability due to some kind of abnormality in a pressure suppressor during operation of a water turbine using a simple control device.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention and is a system diagram of the main parts of a water turbine. 4... Pressure machine, 5, 6... Link mechanism, 20... Guide vane servo motor, 40... Dash pot servo motor.

Claims (1)

[Claims] 1 Equipped with a pressure suppressor whose opening degree is controlled via a link mechanism by a doss pot servo motor that is inserted into the bypass path for the water turbine flow and whose position can be controlled by hydraulic pressure, and a pressure suppressor is installed at the intermediate point of the link mechanism to control the water flow to the water turbine. The guide vane servo motor that drives the guide vane that controls the governor is linked to the guide vane servo motor, and the dart pot servo is connected so that the suppressor is normally closed and the opening degree of the suppressor is adjusted during governor free operation. a hydraulic control circuit for controlling the hydraulic pressure supplied to the motor; and the dart pot servo motor for driving the pressure suppressor in the opening direction in conjunction with the closing operation of the guide vane by the guide vane servo motor when a load is cut off. A dart pot servo motor lock means that blocks the opening/closing hydraulic port and locks it in that position, an abnormality detection means that monitors the opening operation of this pressure suppressor and generates a detection output in the event of an abnormality, and a detection output of this abnormality detection means. A control device for a water turbine, comprising: operation speed suppressing means for switching the operating speed of the guide vane servo motor to suppress the closing operation speed of the guide vane to a low speed.