JP3767918B2 - Inlet valve control device for pump turbine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an inlet valve control device for a pump turbine, and more particularly to an inlet valve control device for a pump turbine that can partially close the inlet valve in accordance with a drop.
[0002]
[Prior art]
A typical pump turbine has a pump characteristic as shown in FIG. 2, and the upper and lower limits of the operation range of the pump turbine are determined by fluctuations in the water levels of the upper pond and the lower pond. Designed to have excellent pump characteristics. Generally, the operating range of the pump turbine is a head fluctuation range as shown in FIG.
[0003]
By the way, since the capacity of the generator motor is determined by the shaft input at the time of the minimum head that becomes the maximum in the operating range, if the lower limit head is reduced in order to widen the operating range, it is necessary to increase the capacity of the generator motor. In addition, the operation exceeding the operation range of the lower limit-upper limit head determined at the time of design adversely affects the pump characteristics of the pump-turbine and becomes a severe operation, and is difficult due to the input / output relationship of the generator motor.
[0004]
On the other hand, it is obliged to install the inlet valve of the pump turbine according to Article 37 No. 3 of the "Ministerial Ordinance for Establishing Technical Standards for Power Generation Hydropower Equipment" as a facility to safely shut off the inflow water to the turbine. Generally, it is installed for the following purposes.
[0005]
(1) In the event of an accident that makes it impossible to stop the pump turbine itself, the water is safely shut off to minimize the accident.
(2) Reduce the amount of water leakage from the pump turbine during a normal stop, reduce power loss, and prevent harmful wear of guide vanes or needles.
(3) Reduce the downtime by omitting water from the water channel during the internal inspection or disassembly work of the water turbine.
(4) When there are other pump turbines or irrigation branch waterways that share the same water channel, stop water from the pump turbines from affecting other pump turbines or irrigation branch circuits.
[0006]
The inlet valve of the pump turbine is installed at the end of the hydraulic iron pipe and immediately before the turbine casing, and is a stop valve that opens and closes when the pump turbine is started and stopped. When the pump turbine is stopped in advance, the guide vanes are fully closed after the load is lowered and no load is applied, and then the water is stopped by fully closing.
[0007]
FIG. 4 shows a conventional inlet valve control device for this type of pump turbine. In the figure, reference numeral 1 denotes a pump turbine, and the pump turbine 1 is driven by a servo motor 3 immediately before the turbine casing 1a. An inlet valve 2 and a side valve 5 are provided at the end of the hydraulic iron pipe 4, respectively. The servo motor 3 and the side valve 5 are controlled by a control mechanism 6.
[0008]
As shown in FIG. 4, the control mechanism 6 supplies pressure oil to the inlet valve electromagnetic pilot switching valve 8 that drives the servo motor 3 by supplying and discharging pressure oil via the operation tube 7 and the side valve 5. A check valve throttle valve 10 for setting the operating speed of the servo motor 3 is provided on the operation pipe 7. .
[0009]
[Problems to be solved by the invention]
The inlet valve 2 of the pump turbine 1 is a water stop valve that is opened and closed as the turbine is operated and stopped as described above. A conventional inlet valve control device for a pump turbine has only a function of fully opening and closing the inlet valve 2, and does not have a function of holding the inlet valve 2 at an intermediate opening.
[0010]
However, in a pumped storage power plant with a drastic fluctuation of water level depending on the season, operation at a low head may be necessary due to the operation of upper dams such as low water levels in preparation for drought or flood. Because of the low head required for this very short period of time, the generator motor of the nagaku pumped-storage power station must have a capacity suitable for it, and the power generation equipment is expensive. There is.
[0011]
The present invention has been made in consideration of the above-described circumstances, and provides a pump turbine inlet valve control device capable of pumping a pump turbine at a low head without increasing the capacity of a generator motor. Objective.
[0012]
Another object of the present invention is to provide an inlet valve control device for a pump turbine that can set each operation speed of the inlet valve at the time of starting the pump turbine and at the time of partial closing control of the inlet valve.
[0015]
[Means for Solving the Problems]
In order to achieve the above-described problems, an inlet valve control device for a pump turbine according to the present invention requires a servo motor that drives the inlet valve of the pump turbine and the servo motor to control the inlet valve at an arbitrary opening degree. And a control means for holding the time. The control means includes a pilot switching valve for an inlet valve for supplying and discharging pressure oil for opening and closing the servo motor via the operation pipe, and a first electromagnetic valve provided on the operation pipe. A first pilot operated check valve controlled by a valve and a first pilot operation check valve which is provided in series with the first pilot operated check valve on the operating pipe and sets an operating speed of the servo motor at the time of partial closing control of the inlet valve A throttle valve with a check valve, and a second pilot operated check valve that is provided on a bypass pipe that bypasses the throttle valve with the first check valve and that releases the check valve function when the pump turbine is started by control of the second solenoid valve; In which and a second with a check valve restrictor valve to set the operating speed of the servo motor when the reversible pump-turbine starter is provided in series with respect to the second pilot-operated check valve on the bypass pipe.
[0018]
[Action]
In the present invention, the control means is provided with an inlet valve pilot switching valve, a first pilot operation check valve, a throttle valve with a first check valve, a second pilot operation check valve and a throttle valve with a second check valve. In the second pilot operated check valve, the check valve function is canceled by the control of the second electromagnetic valve when the pump turbine is started. Therefore, the servo motor operating speed set by the first check valve throttle valve during the inlet valve partial closing control is the servo motor operating speed set by the second check valve throttle valve when the pump turbine is started. Thus, it is possible to switch the operation speed with a simple structure. Further, the control of the first pilot operated check valve by the first electromagnetic valve stops the movement of the servo motor, and the inlet valve can be reliably fixed at an arbitrary opening degree.
[0019]
【Example】
The present invention will be described below with reference to the drawings.
[0020]
FIG. 1 shows an inlet valve control device for a pump turbine according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a pump turbine, and a servo motor is provided immediately before a turbine casing 1a of the pump turbine 1. The inlet valve 2 and the side valve 5 driven by 3 are respectively provided on the end side of the iron pipe 4. The servo motor 3 and the side valve 5 are controlled by a control mechanism 15.
[0021]
As shown in FIG. 1, the control mechanism 15 includes an inlet valve electromagnetic pilot switching valve 16 that drives the servo motor 3 by supplying and discharging pressure oil via the operation pipes 17 a and 17 b, and pressure oil to the side valve 5. And a side-valve electromagnetic pilot switching valve 18 for driving the side valve 5. On the operation pipes 17a and 17b, first pilot operation check valves 19a and 19b and first throttle valves 20a and 20b with check valves are respectively provided in series. The first pilot operation check valves 19a and 19b are controlled by a signal from the first electromagnetic valve 21 to stop the operation of the servo motor 3 at a certain opening degree. Each of the first check valve-equipped throttle valves 20a and 20b sets the operating speed of the servo motor 3 during the inlet valve partial closing control.
[0022]
Further, as shown in FIG. 1, bypass pipes 22a and 22b that bypass the first check valve-equipped throttle valves 20a and 20b are connected to the operation pipes 17a and 17b, respectively. The second pilot operated check valves 23a and 23b and the second check valve-equipped throttle valves 24a and 24b are respectively provided in series on 22b. Each of the second pilot operation check valves 23a and 23b is controlled by a signal from the second electromagnetic valve 25 for switching between “high speed” and “low speed”, and the check valve is started when the pump turbine 1 is started. The function is released. Each of the throttle valves 24a, 24b with the second check valve sets the operating speed of the servo motor 3 when the pump turbine 1 is started.
[0023]
Next, the operation of this embodiment will be described.
[0024]
When the pump turbine 1 is started, first, the second solenoid valve 25 is switched to the “high speed” side. Then, pressure oil is supplied to the second pilot operation valves 23a and 23b, the check valve function of each of the second pilot operation valves 23a and 23b is released, and backflow is enabled. Therefore, the pipes A and B can be used, and the servo motor 3 can operate at a high speed set by the second check valve-equipped throttle valves 24a and 24b.
[0025]
In this state, when the solenoid pilot switching valve 16 for the inlet valve and the first solenoid valve 21 are switched to the “open” side, the pressure oil is servoed through the pipe line D-B (which can also pass through F) -H. It is supplied to the open cylinder of the motor 3. The pressure oil in the cylinder on the closed side of the servo motor 3 flows through the line GA (E), and the first solenoid valve 21 supplies the pressure oil to the first pilot operated check valve 19a to cancel the check valve function. Therefore, the pressure oil further flows through the pipes A-C and is discharged through the inlet valve electromagnetic pilot switching valve 16.
[0026]
When the operation of the pump turbine 1 is stopped , the solenoid pilot switching valve 16 for the inlet valve and the first solenoid valve 21 are switched to the “closed” side, and the pressure oil is supplied to the pipe C-A (E) -G. It flows and is supplied to the closed cylinder of the servo motor 3. The pressure oil in the open cylinder of the servo motor 3 flows through the pipe H-B (F), and the first solenoid valve 21 supplies the pressure oil to the first pilot operated check valve 19b to cancel the check valve function. Therefore, the pressure oil further flows through the pipe BD and is discharged through the inlet valve side electromagnetic pilot switching valve 16.
[0027]
On the other hand, at the time of partial closing control of the inlet valve 2 in the pumping operation at the low head, first, the second electromagnetic valve 25 is switched to the “low speed” side. Then, the check valve functions of the second pilot operation check valves 23a and 23b are restored, and the pipes A and B are closed. For this reason, the servo motor 3 operates at a low speed by the first check valve throttle valves 20a and 20b set for the partial opening operation of the inlet valve 2 on the pipes E and F.
[0028]
In this state, when the inlet valve 2 is opened, the inlet valve side electromagnetic pilot switching valve 16 and the first electromagnetic valve 21 are switched to the “open” side. Then, the pressure oil flows to the open side cylinder of the pipe DFH-servo motor 3. Since the pressure oil in the closed cylinder of the servo motor 3 is supplied to the first pilot operated check valve 19a by the first solenoid valve 21 and the check valve function is released, the line GE- C flows and is discharged through the inlet valve side electromagnetic pilot switching valve 16.
[0029]
The inlet valve 2 has a predetermined opening degree (actually, the opening degree has a width of ±, and if the speed of the inlet valve 2 is too high, racing will occur outside this region. The first solenoid valve 21 is switched to the “closed” side. Then, the pressure oil of the first pilot operation check valve 19a is discharged, and the check valve function of the first pilot operation check valve 19a is restored. For this reason, the flow of the pipe E-C is closed, the movement of the servo motor 3 is stopped, and the inlet valve 2 is fixed at the valve opening degree at that time.
[0030]
【The invention's effect】
As described above, the present invention controls the servo motor by the control means so that the inlet valve can be held for a required time at an arbitrary opening, so that the inlet valve can be partially closed according to the head, By raising the operating head of the pump turbine, the occurrence of excessive shaft input can be suppressed, and the pumping operation can be performed at a low head without increasing the capacity of the generator motor.
[0031]
The present invention also enables the operation speed of the inlet valve to be switched between when the pump turbine is started and when the inlet valve is partially closed. Therefore, when the inlet valve is partially closed, the inlet valve is operated so as not to cause racing. Even if the speed is reduced, the pumped storage power plant can be operated at the same start time as before when the pump is started.
[0032]
The present invention further includes an inlet valve pilot switching valve , a first pilot operated check valve, a throttle valve with a first check valve, a second pilot operated check valve, and a throttle valve with a second check valve in the control means. Therefore, the operation speed can be switched reliably with a simple structure, and the inlet valve can be reliably fixed at an arbitrary valve opening.
[Brief description of the drawings]
FIG. 1 is a piping system diagram showing an inlet valve control device for a pump turbine according to an embodiment of the present invention.
FIG. 2 is a graph showing pump characteristics of a pump turbine.
FIG. 3 is a graph showing a head fluctuation range of a pump turbine.
FIG. 4 is a piping system diagram showing a conventional inlet valve control device for a pump turbine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pump turbine 2 Inlet valve 3 Servo motor 15 Control mechanism 16 Inlet valve electromagnetic pilot switching valve 17a, 17b Operation pipe 19a, 19b 1st pilot operation check valve 20a, 20b 1st check valve throttle valve 21 1st solenoid valve 22a, 22b Bypass pipes 23a, 23b Second pilot operated check valves 24a, 24b Throttle valve with second check valve 25 Second electromagnetic valve

Claims (1)

A servo motor for driving the inlet valve of the pump turbine, and a control means for controlling the servo motor to hold the inlet valve at an arbitrary opening for a required time;
The control means includes an inlet valve pilot switching valve for supplying and discharging pressure oil that opens and closes the servo motor through the operation pipe, and a first pilot operation reverse control provided on the operation pipe and controlled by the first electromagnetic valve. A stop valve, a throttle valve with a first check valve, which is provided in series with the first pilot operation check valve on the operation pipe and sets an operating speed of the servo motor during the inlet valve partial closing control; and a first check A second pilot operated check valve that is provided on a bypass pipe that bypasses the throttle valve with a valve and that releases the check valve function when the pump turbine is started by control of the second solenoid valve; and a second pilot operated on the bypass pipe An inlet valve control device for a pump turbine, comprising a throttle valve with a second check valve, which is provided in series with the check valve and sets the operating speed of the servo motor when the pump turbine is started

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