JPH06117203A - Team valve drive device for steam turbine - Google Patents

Abstract

PURPOSE:To confirm the quick close function soundness of a steam valve without closing it fully by driving a test solenoid valve in a valve test to make a quick operation solenoid valve to output a quick close test signal according to a specified opening condition of a pilot control valve for lock-out and also make it to stop outputting the quick close test signal according to a specified opening condition of the steam valve. CONSTITUTION:When a test solenoid valve 14 is energized, a port (o) of a pilot control valve 15 for lock-out is closed by the hydraulic pressure of emergency oil, a quick operation solenoid valve 10 is energized by the operation of a limit switch 19, a pilot control valve 16 of stop construction is operated, hydraulic pressure at the lower part of a piston 6 is discharged slowly into ports (m) and (n) through an orifice 17, and a steam valve is closed gradually by a needle 2. Since a limit switch 13 de-energizes the quick operation solenoid valve 10 midway during the stroke of the piston 6 to close the pilot control valve 16, hydraulic pressure is supplied again to the lower part of the piston 6 to open the steam valve. Thus the soundness of the steam valve is confirmed by a half-open test without closing it fully.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam valve drive device for a steam turbine used in a steam turbine of a power plant.

[0002]

2. Description of the Related Art A steam valve attached to a steam turbine adjusts the amount of steam passing through the steam turbine in full operation during normal operation or depending on the rotation speed or load of the steam turbine. In order to prevent the rotation speed of the steam turbine from rising, the control device is required to have a strict operation speed, such as a rapid closing operation of its drive device to shut off the steam flowing into the steam turbine.

A typical example of a technique for opening and closing a steam valve used in a conventional large-capacity steam turbine power generator is shown in FIG.
Shown in 1.

The steam valve has a valve body 2 housed in a valve casing 1 and is opened and closed by a force of a valve rod 4 which slides vertically inside a guide piece 3 provided at a lower portion of the valve casing 1. There is. The valve rod 4 is a piston 6 incorporated in an oil cylinder 5.
It is integrally connected to the lot 7 of FIG. 1 and moves in a coordinated manner with the vertical movement of the piston 6. Lot 7 of oil cylinder 5
Is provided with a spring 7a, which constantly applies a force to the lot 7 in the closing direction. Further, a disk dump valve 9 which is guided by a guide pin 8 and which is held by receiving the elastic force of a spring 8a is disposed below the oil cylinder 5.

Next, the valve opening operation will be described.

Now, when the steam turbine is reset, the emergency oil is established, and the emergency oil is supplied to the lower portion of the disk dump valve 9 through the ports a and b of the non-excited quick-acting solenoid valve 10, and the disk is discharged. The dump valve 9 is pushed upward by hydraulic pressure. At the same time, since the emergency oil is also supplied to the shutoff valve 11, the shutoff valve 11 operates in the reverse direction of the built-in spring to open the ports c and d. The control oil is supplied to the port c, and the control oil that has passed through the ports c and d passes through the ports e and f of the test solenoid valve 12 in the non-excited state and flows into the oil cylinder 5. The control oil thus flowing into the oil cylinder 5 pushes up the piston 6 of the oil cylinder 5 and moves the lot 7, the valve rod 4 and the valve body 2 connected to the piston 6 in the opening direction.

Next, the sudden valve closing operation will be described.

When an emergency valve closing command is input to the steam valve, the quick-acting solenoid valve 10 is excited, the ports a and b are closed, and the ports b and j are opened. The emergency oil accumulated in the lower portion of the disc dump valve 9 is released via the ports b and j. In this case, since control oil is supplied to the upper portion of the disc dump valve 9, the disc dump valve 9 moves downward and the lower chamber of the piston 6 communicates with the oil cylinder drain port k. The control oil accumulated in the lower portion of the piston 6 is rapidly discharged from the oil cylinder drain port k, and the piston 6 is rapidly closed by the force of the spring 7a. Since the port b of the quick-acting solenoid valve 10 is also connected to the shut-off valve 11, when the quick-acting solenoid valve 10 operates, the shut-off valve 1 operates simultaneously with the above operation.
The piston 1a of No. 1 operates by a spring to close the port c and shut off the supply of control oil.

Next, the valve test operation will be described.

The steam valve used in the steam turbine is a valve body 2
Is exposed to high temperature and high pressure all the time, it is expected that the valve rod 4 will be deformed due to excessive thermal stress during a long period of use, and that oxidized scale in the steam will cause the valve rod 4 and the guide piece 3 to deform.
May enter the gap as foreign matter. Further, a so-called galling phenomenon of the valve rod 4 occurs due to a decrease in the gap between the valve rod 4 and the guide piece 3 due to the oxide scale generated on the valve rod 4,
Because it is expected that the valve body 2 will not close normally,
A so-called valve test is performed to open and close the steam valve during operation of the steam turbine. It should be noted that this valve test is carried out at the same time for the purpose of confirming that the oil cylinder 5, which is the drive mechanism, operates normally.

First, referring to FIG. 12, the valve test is started at time t1, the test solenoid valve 12 is excited, and the ports f and i are opened. The control oil supplied to the lower portion of the piston 6 of the oil cylinder 5 is discharged to the drain through the ports f and i of the test solenoid valve 12 via the orifice 18, and the piston 6 gradually operates in the closing direction. When the piston 6 operates about 90% of the entire stroke, the position detection limit switch 13 attached to the lot 7 is activated, and the actuation signal of this position detection limit switch 13 causes the rapid operation solenoid valve to operate at time t2. 10 is excited, the disk dump valve 9 operates in the same manner as the valve rapid closing operation described above, and moves downward, so that the piston 6 is rapidly closed during 10% of the total stroke. The rapid-acting solenoid valve 10 is de-energized at time t3, and then the test solenoid valve 12 is de-energized. by this,
The steam valve is fully opened again, and the valve test ends at time t4. In the above valve test, normally, the valve closing speed is adjusted so as to be fully closed in 10 to 20 seconds, the soundness of the steam valve is confirmed in 90% of the entire stroke, and the soundness of the drive unit is checked in the remaining 10%. Have confirmed. This is done by rapidly closing the steam valve for a valve test during steam turbine operation, causing a sudden change in the amount of steam flowing into the steam turbine, resulting in a sudden change in steam turbine output or a sudden increase in main steam pressure. This will adversely affect the balance of.

[0012]

However, in a steam turbine power generation facility having a plurality of steam stop valves, a steam control valve, a reheat steam stop valve, and an intercept valve for one steam turbine, driving with a conventional configuration is required. Although the equipment was performing well, as the technology for increasing the size of steam valves progressed, a plant was constructed with one main steam stop valve and one reheat steam valve for each steam turbine. It came to be developed. The use of each steam valve will greatly reduce the cost of the steam turbine equipment, but the following problems arise during the valve test.

That is, in the valve test of the steam valve in this case, a method of operating only about 20 to 30% of the stroke without fully closing the valve is adopted. This is a so-called semi-closed test because the steam that flows into the steam turbine is completely shut off when the valve is fully closed as described in the related art. By this semi-closed test, it is possible to confirm that the operation of the valve stem of the steam valve and the guide piece is smooth, and prevent so-called valve stem stick. However, in the configuration of the disk dump valve 9 described in the related art, if the quick-acting electromagnetic valve 10 is operated and a valve test is performed, the steam valve is fully closed, so another confirmation item, that is, the quick closing function of the oil cylinder. There is a problem that it cannot be confirmed.

When the oil cylinder 5 is suddenly closed, the quick-acting solenoid valve 10 is excited and the disc dump valve 9 is operated as described above, but a series of confirmation tests cannot be performed in the valve test.
For example, it cannot be confirmed unless the steam turbine is actually stopped. For example, the quick-acting solenoid valve 10 is stuck and causes a malfunction, or the quick-acting solenoid valve 10 and the excitation sequence are defective. Normally, some steam turbines are continuously operated for one to two years once the operation is started. During this period, the soundness of these drive devices cannot be confirmed at all, and the load on the steam turbine is cut off. There is a problem that the steam turbine may still run away in the event of an emergency.

Another problem is that when the valve test of a steam turbine such as a nuclear power turbine plant is to be fully closed for each valve, a slight fluctuation of the main steam pressure occurs.
Since it becomes a disturbance of the nuclear power plant, a method of slightly moving the steam valve (about 10% of the total stroke) is used without performing the full-closed test. Even in this case, the sticking of the steam valve body is prevented as in the above case, but there is a problem that the operation of the oil cylinder cannot be confirmed.

Therefore, according to the present invention, during the steam valve valve test of the steam turbine, it is possible to confirm the soundness of the rapid closing function of the drive device without adopting a means for fully closing the steam valve. The purpose is to provide.

[0017]

According to a first aspect of the present invention, a steam valve which is opened and closed by driving a valve body and a piston which is connected to the valve body are housed, and the piston is driven by the supply of emergency oil to open the steam valve. While operating, the oil cylinder that drives the piston to close the steam valve by discharging the emergency oil, the supply passage provided to supply the emergency oil to this oil cylinder, and discharge the emergency oil from the oil cylinder The discharge flow path provided for this purpose, the pilot control valve of the check valve structure that is provided in this discharge flow path and opens during operation to discharge the emergency oil to the outside, and the steam valve quick close signal or quick close test signal. A quick-acting solenoid valve that operates a pilot control valve with a check valve structure, and a lockout that is installed in the discharge flow path upstream of the pilot control valve with a check valve structure and that closes when operating to prevent discharge of emergency oil. Pilot control And a test solenoid valve that operates this lockout pilot control valve during a valve test, and an orifice provided in a bypass discharge flow path that bypasses the lockout pilot control valve, and drives the test solenoid valve during a valve test. When the lockout pilot control valve is closed for a predetermined period, the quick-action solenoid valve outputs a quick-close test signal, while the steam valve opens for a predetermined period to stop outputting the quick-close test signal. is there.

According to a second aspect of the present invention, a steam valve that is opened and closed by driving the valve body and a piston that is connected to the valve body are accommodated, and the piston is driven by the supply of emergency oil to open the steam valve while the emergency operation is performed. An oil cylinder that drives a piston to close the steam valve by discharging oil, a supply flow path that is provided to supply emergency oil to the oil cylinder, and a discharge flow path that is provided to discharge emergency oil from the oil cylinder And a pilot control valve with a check valve structure that is provided in this discharge flow path and opens during operation to discharge emergency oil to the outside, and a pilot valve with a check valve structure by a steam valve quick close signal or a quick close test signal. A quick-acting solenoid valve that operates the control valve, a pilot control valve for lockout that is provided in the discharge flow path downstream of the pilot control valve with a check valve structure and closes during operation to prevent the discharge of emergency oil. Lock The test solenoid valve that activates the auto pilot control valve during the valve test, and the exhaust flow path that branches off from the exhaust flow path between the check valve structure pilot control valve and the lockout pilot control valve are connected to the outside. The test solenoid valve is driven during the valve test, and a quick closing test signal is output to the quick-acting solenoid valve according to the predetermined closed state of the lockout pilot control valve, while the steam valve has the predetermined open state. The output of the quick closing test signal is stopped by.

[0019]

In the first aspect of the invention, the pilot control valve of the check valve structure opens due to the operation of the quick-acting solenoid valve when the steam valve is rapidly closed. In this case, the lock-out pilot control valve is open because the test solenoid valve is not driven. Therefore, the emergency oil in the oil cylinder is discharged to the outside and closes rapidly.
Also, during the valve test, the test solenoid valve is driven to set the lockout pilot control valve to the closing direction, and when the predetermined closing is reached, the quick-acting solenoid valve is actuated to close the check valve structure pilot control valve. Therefore, the emergency oil is gradually discharged to the outside through the orifice. This allows
Since the emergency oil in the oil cylinder is discharged, the steam valve is slowly opened, and when the predetermined opening is reached, the quick-acting solenoid valve is deactivated and stopped.

According to the second aspect of the present invention, when the steam valve is rapidly closed, the quick-acting solenoid valve operates, the pilot control valve of the check valve structure opens, and the test solenoid valve is not driven either. , The emergency oil in the oil cylinder is discharged to the outside, and the steam valve is closed rapidly. Also, during the valve test,
When the test solenoid valve is driven to set the lockout pilot control valve in the closing direction and a predetermined opening is reached, the quick-acting solenoid valve 10 is operated to open the pilot control valve having the check valve structure. In this case, since the lockout pilot control valve is closed, the emergency oil is throttled by the orifice and discharged slowly.
The steam valve is slowly closed, and when it reaches a predetermined opening, the quick-acting solenoid valve is deactivated and stopped.

Therefore, according to the invention of claim 1 and the invention of claim 2, the operation of the quick-acting solenoid valve and the operation of the pilot control valve of the check valve structure can be confirmed at the time of the valve test, and the closing operation of the steam valve can be performed. It is possible to confirm the soundness of the steam valve drive device by a so-called half-open test in which the steam valve is slowly closed and the steam valve is not fully closed but returned from an intermediate opening.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a steam valve drive system for a steam turbine showing a first embodiment of the present invention. In the figure,
The upper part of the steam valve and the piston 6 of the oil cylinder 5 is the same as that described in FIG. 11. The lower part of the piston 6 of the oil cylinder 5
The pilot control valve 15 driven by the test solenoid valve 14 is connected to a port o, and the oil drain port 1 is connected to a port m of a pilot control valve 16 having a check valve structure.
The port o and the port 1 of the pilot control valve 15 are connected by a bypass orifice 17 provided side by side. Emergency oil is supplied to the pilot control valve 16 of the check valve structure via the ports a and b of the quick-acting solenoid valve 10,
The port m of the pilot control valve 16 is closed. In addition, the emergency oil passes through the orifice 18 and the oil cylinder 5
Is being supplied to the lower part of the piston 6, and the lower part pressure of the piston 6 is constantly maintained at a high value. During normal operation, the test solenoid valve 14 is not excited, so that the pilot control valve 15 has the ports o and l in the open state due to the force of the spring and the hydraulic force of the emergency oil.

Next, the operation of this embodiment when the steam valve is rapidly closed will be described with reference to FIG.

First, when an emergency closing command is input to the steam valve,
The quick-acting solenoid valve 10 is excited to close the ports a and b and open the ports b and j. As a result, the hydraulic pressure in the lower portion of the piston of the pilot control valve 16 having the check valve structure is discharged to the drain through the ports b and j of the quick-acting solenoid valve 10, and the inlet port m of the pilot control valve 16 is connected to the oil cylinder 5 The hydraulic pressure under the piston 6 is the pilot control valve 1 for lockout
5, the piston of the pilot control valve 16 is actuated, and the ports m and n are opened. Therefore, the oil below the piston 6 of the oil cylinder 5 is rapidly discharged to the drain, and the oil cylinder 5 is rapidly closed. During this time, the emergency oil is supplied to the lower portion of the piston 6 via the orifice 18, but the orifice diameter is set so that the amount of oil flowing through the orifice 18 is a slight amount. It does not affect the closing action of.

The above rapid closing operation has been described for the case where the quick-acting solenoid valve 10 is excited, but the emergency oil supplied to the quick-acting solenoid valve 10 by the operation of the emergency speed governor (not shown) of the steam turbine. When the oil pressure is lost, the pilot control valve 16 operates similarly and the piston 6 of the steam valve oil cylinder 5 is rapidly closed.

Next, the operation during the valve test will be described with reference to FIG.

When the test solenoid valve 14 is excited, the ports e and f of the test solenoid valve 14 are opened, and the emergency oil is supplied to the pilot control valve 15 for lockout, and the pilot control valve 15 for lockout is supplied. Close the port o.
The movement of the piston of the pilot control valve 15 for lockout is detected by the limit switch 19, and the rapid actuation solenoid valve 10 is excited.

When the rapid-acting solenoid valve 10 is excited, the ports a and b are closed and the ports b and j are opened, so that the pilot control valve 16 having the check valve structure operates and the ports m and
n open, but pilot control valve for lockout 1
Because the port o of 5 is closed, the piston 6 of the oil cylinder 5
The hydraulic pressure in the lower part of is discharged to the drain through the bypass orifice 17 only. This bypass orifice 17 is
Because the diameter is slightly larger than the orifice 18,
The lower oil of the piston 6 of the oil cylinder 5 is slowly discharged, and the steam valve is gradually closed. The position of the operation of the piston 6 is detected by the position detecting limit switch 13 installed in the lot 7. And 80 ~ of all strokes
When the stroke reaches 70%, the position detection limit switch 13 operates to release the excitation of the rapid operation solenoid valve 10.

By releasing the excitation of the quick-acting solenoid valve 10, the pilot control valve 16 of the check valve structure closes its port m, the hydraulic pressure is supplied again to the lower portion of the piston 6 of the oil cylinder 5, and the steam valve is opened. Take action. When the steam valve is fully opened or the position detection limit switch 13 is reset, the test solenoid valve 14 is deenergized, and the lockout pilot control valve 15 controls the spring force and the pressure at the bottom of the piston 6 of the oil cylinder 5. It returns to its original position due to the force of oil.
This series of operations completes the half-closed test of the steam valve.

FIG. 4 shows another embodiment in which a servo valve 20 is installed between the emergency oil and the piston 6 of the oil cylinder 5 instead of the orifice 18 of the embodiment shown in FIG. According to this embodiment, the intermediate opening degree of the oil cylinder 5 can be controlled, and the oil cylinder can be used as an oil cylinder such as a steam control valve and an intercept valve.

FIG. 5 shows an embodiment in which a port for switching the emergency oil to be supplied to the lower portion of the piston 6 of the oil cylinder 5 is built in the rapid operation solenoid valve 10. According to this embodiment, the rapid operation solenoid valve 10 is provided. During the operation of 1, the emergency oil supplied to the oil cylinder 5 is shut off, and unnecessary emergency oil is prevented from flowing out.

FIG. 6 shows an embodiment in which the bypass orifice 17 provided in parallel with the lockout pilot control valve 15 is installed inside the lockout pilot control valve 15, and the same operation is performed. In the present embodiment, the quick-acting solenoid valve 10, the test solenoid valve 14, the orifice 18
Alternatively, the same emergency oil is supplied to the servo valve 20, but needless to say, the same effect can be obtained by separating the emergency oil supplied to the above-mentioned constituent elements other than the rapid operation solenoid valve 10.

As described above, during the half-closed test of the steam valve, it is possible to confirm not only the operation of the steam valve but also the operation of the quick-acting solenoid valve and the operation of the pilot control valve, and the steam valve of the reliable steam turbine. A drive device can be provided.
Further, by adopting the above-described highly reliable steam valve drive device for a steam turbine, it becomes possible to make one steam valve in a state where a plurality of steam valves are conventionally installed, which greatly contributes to the cost. it can. Further, even in a plant such as a nuclear power plant where the disturbance to the main steam system is remarkably disliked, the reliability can be improved by adopting the steam valve drive device of the steam turbine according to the configuration of the present invention.

FIG. 7 is a block diagram of a steam valve drive system for a steam turbine showing a second embodiment of the present invention.

In the figure, the portion above the steam valve and the piston 6 of the oil cylinder 5 is the same as that described in FIG. Oil cylinder 5
The lower part of the piston 6 is connected to the port m of the pilot control valve 16 of the check valve structure. The pilot control valve 16 of the check valve structure is connected to the ports a and b of the quick-acting solenoid valve 10. Emergency oil is supplied. Therefore, the port m of the pilot control valve 16 is closed. In addition, the emergency oil passes through the orifice 18 and the oil cylinder 5
The piston 6 is communicated with the lower part of the piston 6, and the lower part pressure of the piston 6 is always kept high.

On the other hand, a pilot control valve 1 having a check valve structure
The drain port n of 6 is connected to the port o of the pilot control valve 15 driven by the test solenoid valve 14, and the drain port n is discharged to the drain through the bypass orifice 17. ing. During normal operation, the lock-out test solenoid valve 14 is not excited, so that the pilot control valve 15 has the ports o and l opened due to the force of the spring.

Next, the operation of this embodiment when the steam valve is rapidly closed will be described with reference to FIG.

First, when a valve closing command is input to the steam valve at the time of rapid closing,
The quick-acting solenoid valve 10 is excited, the ports a and b are closed, and the ports b and j are opened. The lower hydraulic pressure of the piston 6 of the pilot control valve 16 having the check valve structure is discharged to the drain through the ports b and j of the quick operation solenoid valve 10. Since the hydraulic pressure below the piston 6 of the oil cylinder 5 is applied to the inlet port m of the pilot control valve 15, the pilot control valve 1
The piston 6 of No. 6 is operated, and the ports m and n of the pilot control valve 16 are opened. The oil pressure that has passed through the oil discharge port n of the pilot control valve 16 is
The oil is rapidly discharged to the drain through 1 and the piston 6 of the oil cylinder 5 is rapidly closed.

During this time, the emergency oil is supplied to the lower portion of the piston 6 through the orifice 18, and the orifice 1
Since the orifice is set so that the amount of oil flowing through 8 is small, it does not affect the closing operation of the piston 6 of the oil cylinder 5 so much. Note that the above rapid closing operation has been described in the case where the quick-acting solenoid valve 10 is excited, but the pilot control valve 16 is used even when the emergency oil is lost due to the operation of the emergency speed governor (not shown) of the steam turbine. Performs the same operation as the oil cylinder 5
Piston 6 closes rapidly.

Next, the operation during the valve test will be described with reference to FIG.

First, when the test solenoid valve 14 is excited,
The ports e and f of the test solenoid valve 14 are opened, the emergency oil is supplied to the lockout pilot control valve 15, and the port o of the lockout pilot control valve 15 is closed. The operation of the piston of the lockout pilot control valve 15 is detected by the limit switch 19, and the rapid operation solenoid valve 1
0 is excited. When the quick-acting solenoid valve 10 is excited,
Since ports a and b are closed and ports b and j are open,
The pilot control valve 16 having the check valve structure is operated, and the ports m and n are opened. Lockout pilot control valve 1
Since the port o of 5 is closed, the lower hydraulic pressure of the piston 6 of the oil cylinder 5 is discharged to the drain through only the bypass orifice 17. Since the bypass orifice 17 has a diameter slightly larger than that of the orifice 18, the oil cylinder 5
The lower hydraulic pressure of the piston 6 is slowly discharged, and the steam valve is gradually closed.

The operation of the piston 6 is detected by the position detecting limit switch 13 installed in the lot 7, and the position detecting limit switch 13 detects the position and reaches 80 to 70% of the total stroke. Works,
The excitation of the rapid operation solenoid valve 10 is released. When the rapid-acting solenoid valve 10 is de-energized, the pilot control valve 16 having a check valve structure closes its port m, hydraulic pressure is supplied to the lower portion of the piston 6 of the oil cylinder 5, and the steam valve opens. When the steam valve is fully opened or the position detection limit switch 13 is reset, the excitation of the test solenoid valve 14 is released, and the pilot control valve 15 for lockout returns to the original position. This series of operations completes the steam valve half-closed test.

As described above, during the half-closed test of the steam valve, it is possible to confirm not only the operation of the steam valve but also the operation of the quick-acting solenoid valve and the operation of the pilot control valve, and it is possible to reliably drive the steam valve of the steam turbine. A device can be provided. In addition, by adopting a reliable steam valve drive device for a steam turbine, it becomes possible to use a single steam valve for a steam turbine, which has been conventionally installed in plural numbers, and to greatly contribute to the cost. it can. Further, even in a plant such as a nuclear power plant that reluctantly disturbs the main steam system, the reliability can be improved by adopting the steam valve drive device of the steam turbine having the configuration of the present embodiment.

Here, another embodiment of the present invention in which a servo valve 20 is installed between the emergency oil and the piston 6 of the oil cylinder 5 instead of the orifice 18 of the embodiment shown in FIGS. As shown in FIG. In this embodiment as well, it is possible to control the intermediate opening degree of the oil cylinder 5, and it can be used as an oil cylinder such as a steam control valve and an intercept valve. In the description of the present embodiment, only the emergency oil is supplied to the quick-acting solenoid valve 10, the test solenoid valve 14 or the orifice 18, and the servo valve 20, but each component other than the quick-acting solenoid valve 10 is described. The same effect can be obtained by separating the oil supplied to the oil from the emergency oil and using it as the control oil.

[0046]

As described above, according to the present invention, the operation of the quick-acting solenoid valve and the operation of the pilot control valve having the check valve structure can be confirmed during the valve test, and the closing operation of the steam valve is slowed down. Since the operation is performed at a speed, the soundness of the drive device including the rapid closing function of the steam valve can be confirmed by a so-called half-open test in which the steam valve is not fully closed but is returned from an intermediate opening. As a result, the steam valve drive device of the steam turbine is reliable, and by adopting the steam valve drive device of the reliable steam turbine, it is possible to reduce the number of steam valves of the steam turbine which has been conventionally set to one. It becomes possible to make it a valve, and it can contribute greatly to the cost. Further, the reliability can be improved by adopting it to a nuclear power plant that reluctantly disturbs the main steam system.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a steam valve drive device of a steam turbine showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a first action of the steam valve drive system of the steam turbine of FIG.

FIG. 3 is an explanatory view showing a second action of the steam valve driving device of the steam turbine of FIG.

FIG. 4 is a configuration diagram showing another configuration of the present invention shown in FIG.

5 is a configuration diagram showing another configuration of the present invention shown in FIG. 1. FIG.

6 is a configuration diagram showing another configuration of the present invention shown in FIG.

FIG. 7 is a configuration diagram of a steam valve drive device of a steam turbine showing a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a first action of the steam valve drive system of the steam turbine of FIG. 7.

FIG. 9 is an explanatory diagram showing a second action of the steam valve driving device of the steam turbine of FIG. 7.

FIG. 10 is a configuration diagram showing another configuration of the present invention shown in FIG. 7.

FIG. 11 is a configuration diagram of a conventional steam valve drive device for a steam turbine.

FIG. 12 is a time chart showing the operation of a conventional steam valve drive device for a steam turbine.

[Explanation of symbols]

 1 Valve casing 2 Valve body 5 Oil cylinder 6 Piston 7 Lot 10 Rapid actuation solenoid valve 12 Test solenoid valve 13 Position detection limit switch 14 Test solenoid valve 15 Pilot control valve 16 Pilot control valve 17 Bypass orifice 18 Orifice 19 Limit switch

Claims (2)

[Claims] 1. A steam valve that opens and closes when driven by a valve body, and a piston that is connected to the valve body are housed, and the piston is driven by the supply of emergency oil to open the steam valve while the emergency oil An oil cylinder for driving the piston to close the steam valve by discharging, a supply passage provided for supplying the emergency oil to the oil cylinder, and a discharge passage for discharging the emergency oil from the oil cylinder A discharge flow path, a pilot control valve with a check valve structure that is provided in this discharge flow path and opens during operation to discharge the emergency oil to the outside, and a reverse valve by a steam valve quick close signal or a quick close test signal. A quick-acting solenoid valve that operates a pilot control valve with a stop valve structure, and a lock that is provided in the discharge flow path upstream of the pilot control valve with a check valve structure and that closes during operation to prevent discharge of the emergency oil A pilot control valve for lockout, a test solenoid valve for operating this lockout pilot control valve during a valve test, and an orifice provided in a bypass discharge flow path that bypasses the lockout pilot control valve. Sometimes, the test solenoid valve is driven to output the quick-close test signal to the quick-acting solenoid valve according to a predetermined closed state of the lockout pilot control valve, while the quick close is performed due to a predetermined open state of the steam valve. A steam valve drive device for a steam turbine, wherein output of a test signal is stopped. 2. A steam valve that opens and closes when driven by a valve body, and a piston that is connected to the valve body are housed, and the piston is driven by the supply of emergency oil to open the steam valve while the emergency oil An oil cylinder for driving the piston to close the steam valve by discharging, a supply passage provided for supplying the emergency oil to the oil cylinder, and a discharge passage for discharging the emergency oil from the oil cylinder A discharge flow path, a pilot control valve with a check valve structure that is provided in this discharge flow path and opens during operation to discharge the emergency oil to the outside, and a reverse valve by a steam valve quick close signal or a quick close test signal. A quick-acting solenoid valve that operates a pilot control valve with a stop valve structure, and a lock that is provided in the discharge flow path downstream of the pilot control valve with a check valve structure and that closes when operating to prevent discharge of the emergency oil. Out pilot control valve, a test solenoid valve for operating this lockout pilot control valve during a valve test, and the discharge flow path between the pilot control valve of the check valve structure and the lockout pilot control valve. Has an orifice that is provided in a discharge flow path that branches from the outside and communicates with the outside, drives the test solenoid valve at the time of a valve test, and causes the rapid operation solenoid valve to operate by the predetermined closed state of the lockout pilot control valve. A steam valve drive device for a steam turbine, wherein while outputting a rapid closing test signal, the output of the rapid closing test signal is stopped by a predetermined opening state of the steam valve.