JP2019031941A - Steam valve driving device and steam valve - Google Patents

Abstract

To provide a steam valve driving device and a steam valve capable of being continuously operated even in occurrence of incompatibility in a control valve.SOLUTION: A steam valve driving device for controlling an amount of steam includes a control device, a first control valve for controlling an amount of working fluid, a second control valve disposed in parallel with the first control valve, first and third cutoff valves for cutting supply of the working fluid to the control valve and discharge of the working fluid from the control valve, second and fourth cutoff valves for cutting supply of the working fluid to a hydraulic cylinder device from the control valve and discharge to the control valve from the hydraulic cylinder device, and a bypass flow channel. The steam valve driving device continuously operates the steam valve by the second control valve on the basis of a signal from the control device, closes the first and second cutoff valves, and discharges the working fluid in the first control valve between the first and second cutoff valves and the first control valve through the bypass flow channel, when incompatibility occurs in the first control valve.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a steam valve driving device and a steam valve.

  The rotation speed and output of the steam turbine are adjusted by the flow rate of the steam introduced into the steam turbine. The steam flow rate is adjusted by controlling the opening of the steam valves (main steam stop valve, steam control valve, etc.) mounted at the inlet of the steam turbine with the steam valve drive unit connected to each steam valve. Is called. The steam valve driving device has a control valve (servo valve, electromagnetic valve) that introduces or drains hydraulic fluid into a flow path and a cylinder that houses a piston that opens and closes the steam valve. The servo valve adjusts the amount of hydraulic oil supplied to the cylinder by a control signal. That is, the opening degree of the steam valve is controlled by adjusting the amount of hydraulic oil with the servo valve. On the other hand, the solenoid valve is used as a main steam stop valve, and permits or shuts off the hydraulic oil supplied to the cylinder by a control signal, and fully opens (permits) or fully closes (shuts down) the opening of the main steam stop valve. Therefore, when the opening degree of the steam valve cannot be controlled via the control valve, the flow rate of the steam introduced into the steam turbine cannot be adjusted, and the continuous operation of the steam turbine cannot be performed.

  In response to the above-mentioned concerns, the conventional steam valve driving device is provided in each of a plurality of steam valves, and the hydraulic oil is discharged after closing the steam valve controlled by the control valve of the steam valve driving device in which an abnormality has occurred. Then, replace the control valve. In the meantime, since the adjustment of the flow rate of the steam is continued by another steam valve, the steam turbine can be continuously operated even when an abnormality occurs in one control valve. However, when an abnormality occurs due to the nonconformity of the control valve, it is necessary to fully close the steam valve, and it takes a long time to recover after replacement. Further, when there is only one steam valve, it is necessary to stop the operation of the steam turbine itself. Therefore, there is a need for a steam valve drive device and a steam valve that can continue operation even when an abnormality occurs in the control valve.

JP2015-78618A Japanese Examined Patent Publication No. 3-3042

  The problem to be solved by the present invention is to provide a steam valve driving device and a steam valve that can be continuously operated even when a nonconformity occurs in a control valve.

In order to solve the above-described problems, according to the steam valve driving device of the embodiment, the steam valve driving device for controlling the amount of steam introduced into the steam turbine, the steam valve includes: a valve body; A hydraulic cylinder device for adjusting the opening degree of the valve body, and adjusting the steam amount by adjusting the opening degree of the valve body according to the amount of hydraulic oil supplied to the hydraulic cylinder device In the valve drive device, a control device for controlling the amount of the hydraulic oil supplied to the hydraulic cylinder device;
A first control valve that controls the amount of the hydraulic fluid supplied to the hydraulic cylinder device by a signal from the control device, and a first control valve that are provided in parallel with the first control valve, are supplied to the hydraulic cylinder device. A second control valve that controls the amount of the hydraulic oil, and a first control valve that blocks supply of the hydraulic oil to the first control valve and discharge of the hydraulic oil from the first control valve. And a second shut-off valve that shuts off the supply of the hydraulic oil from the first control valve to the hydraulic cylinder device and the discharge of the hydraulic oil from the hydraulic cylinder device to the first control valve. A third shut-off valve that shuts off the supply of the hydraulic oil to the second control valve and the discharge of the hydraulic oil from the second control valve, and the hydraulic cylinder from the second control valve Supply of the hydraulic oil to a device and the second control from the hydraulic cylinder device A fourth shut-off valve that shuts off the discharge of the hydraulic oil to the first pipe, and a branch from between the first control valve and the first and second shut-off valves, and the second control valve and the A bypass flow path that branches off from between the third and fourth shut-off valves and discharges the hydraulic oil, and the steam valve drive device is configured when the first control valve is incompatible. , By controlling the amount of the hydraulic oil supplied to the hydraulic cylinder device using the second control valve according to a signal from the control device, the steam valve is continuously operated, and the first and second The shut-off valve is closed, passes through the bypass flow path, and discharges hydraulic oil between the first and second shut-off valves and the first control valve and in the first control valve.

It is a figure showing an example of the steam turbine power generation equipment provided with the steam valve drive device which concerns on 1st and 2nd embodiment. It is a figure showing the structure of the steam valve drive device which concerns on 1st embodiment. In the steam valve drive device concerning a first embodiment, it is a flow showing the operation procedure at the time of nonconformity generating to one servo valve. It is a figure showing the structure of the conventional steam valve drive device. It is the systematic diagram of the servo valve 90 of the conventional steam valve drive device, Comprising: (a) When a servo valve exists in an initial position, (b) The case where a servo valve opens and supplies hydraulic fluid to a steam valve is each shown.

  Hereinafter, the steam valve drive device according to the embodiment will be described.

  Drawing 1 is a figure showing an example of the steam turbine power generation equipment provided with the steam valve drive device concerning a 1st and 2nd embodiment. This steam turbine power generation facility is equipped with at least one steam valve driving device according to each embodiment described later. A steam turbine power generation facility 1 shown in FIG. 1 represents, for example, a thermal power plant. The steam turbine power generation facility 1 includes a boiler 2, a high pressure turbine 3, a reheater 4, a low pressure turbine 5, a condenser 6, and a feed water pump 7.

  The boiler 2 heats water and generates steam. This steam is introduced into the high-pressure turbine 3 through the main steam stop valve 11 and the steam control valve 12 in order. The high-pressure turbine 3 is a turbo machine and is rotated by the introduced steam. The high-pressure turbine 3 is connected to the reheater 4, and sends the expanded steam after work to the reheater 4. The reheater 4 removes the moisture of the steam that has worked in the high-pressure turbine 3 and heats it. The steam that has passed through the reheater 4 is introduced into the low-pressure turbine 5. The low-pressure turbine 5 is a turbo machine having a rotating shaft directly connected to the high-pressure turbine 3, and is rotated by steam introduced from the reheater 4. The rotation of the high-pressure turbine 3 and the low-pressure turbine 5 is transmitted to a generator (not shown) via a rotating shaft, and contributes to power generation by the generator. On the other hand, the low-pressure turbine 5 is connected to the condenser 6, and sends the expanded steam after finishing work to the condenser 6. The condenser 6 condenses the steam worked in the low-pressure turbine 5 and returns it to water. The feed water pump 7 pressurizes this water and sends it to the boiler 2.

  Here, the main steam stop valve 11 fully closes or fully opens the valve body by the steam valve driving device, and interrupts or permits the supply of steam to the high pressure turbine 3 and the low pressure turbine 5. On the other hand, the steam control valve 12 controls the amount of steam supplied to the high-pressure turbine 3 and the low-pressure turbine 5 by adjusting the opening of the valve body by the steam valve driving device.

(Comparative example)
Next, in describing the steam valve driving device according to the embodiment, a conventional steam valve driving device will be described with reference to FIG. 4 as a comparative example. FIG. 4 is a diagram illustrating a configuration of a conventional steam valve driving device. A conventional steam valve driving device 80 is connected to the steam valve 70 and includes a servo valve 90 as a control valve and a control device 100. The steam valve driving device 80 is provided in each of the plurality of steam valves 70. When non-conformance occurs in the servo valve 90, the steam valve 70 connected to the servo valve 90 is fully closed, the hydraulic oil is discharged, and the servo valve 90 in which the non-conformance has occurred is replaced.

  The opening and closing of the valve body 71 is adjusted by introducing hydraulic oil 81 from the steam valve driving device 80 to the hydraulic cylinder device 72. The hydraulic cylinder device 72 is divided into a working chamber 72 a into which the working oil 81 is introduced and a non-working chamber 72 b by a piston 73 connected to the valve body 71. Further, the hydraulic cylinder device 72 is provided with a spring 74 so as to cover the axis of the piston 73 spirally. The spring 74 applies a restoring force to the piston 73 and operates to close the valve body 71. The piston 73 moves upward by the hydraulic pressure of the hydraulic oil 81 against the restoring force of the spring 74 and the pressure of the steam applied to the valve body 71, and operates to open the valve body 71 of the steam valve 70.

  The opening detector 75 is connected to the piston 73 of the hydraulic cylinder device 72 and transmits the opening of the valve body 71 following the movement of the piston 73 to the control device 100 as an electrical signal.

  The steam valve driving device 80 is discharged from a hydraulic pressure generator (not shown) to the hydraulic cylinder device 72 and to the hydraulic cylinder device 72 and from the hydraulic cylinder device 72 toward a tank (not shown). And a flow path for the discharged oil 82 (discharged hydraulic oil). When exchanging the servo valve 90, the steam valve 70 is operated to be fully closed by a signal from the control device 100. That is, the oil filled in the working chamber 72 a is discharged as drain oil 82 through the servo valve 90. When a turbine trip occurs, the oil filled in the working chamber 72a is directly discharged as drain oil 82 via a trip circuit (not shown).

  The control device 100 receives the opening degree of the valve body 71 from the opening degree detector 75 as an electric signal. In addition, the control device 100 generates a signal for controlling the flow of the hydraulic oil 81 supplied from the steam valve driving device 80 to the working chamber 72a and the flow of the exhaust oil 82 discharged from the working chamber 72a to the steam valve driving device 80. Transmit to servo valve 90. In particular, during rated operation, the servo valve 90 is in an open state, and the control device 100 controls the servo valve 90 so that the opening degree of the valve body 71 received from the opening degree detector 75 is constant.

  Here, the configuration of the servo valve 90 and the method of supplying the hydraulic oil 81 to the steam valve 70 will be described with reference to FIGS. 4 and 5. FIG. 5 is a system diagram of a servo valve 90 of a conventional steam valve driving device, where (a) the servo valve is in the initial position, (b) the servo valve is opened, and hydraulic oil is supplied to the steam valve. Respectively.

  The servo valve 90 is a conventionally used nozzle flapper type servo valve, and includes a flow path 92aa, an orifice 92b, a spool 93, a pilot port 94a, a supply port 94b, a control port 94c, and a return port 94d. A control port 94e, an armature 95, a flapper 96, a spring 97, a coil 98, and a magnetic pole 99. The spool 93 is connected to the lower end of the flapper 96 via a spring 97. It controls the flow of hydraulic oil 81 introduced into the working chamber 72a from a hydraulic pressure generator (not shown) and the flow of exhaust oil 82 discharged from the working chamber 72a. In the comparative example, the control port 94c is a port for supplying the working oil 81 to the working chamber 72a, and the control port 94e is a port for introducing the drain oil 82 discharged from the working chamber 72a.

  Specifically, the hydraulic oil 81 is introduced into the flow path 92a from the hydraulic pressure generator (not shown) through the pilot port 94a. The flow rate of the hydraulic oil 81 introduced from the left and right pilot ports 94a into the flow path 92a is reduced by the orifices 92b provided on the left and right sides of the flow path 92a. This state in which the spool 93, the armature 95, and the flapper 96 are not biased is defined as an initial position (the state shown in FIG. 5A). When a signal (current) is transmitted from the control device 100 to the coil 98 with respect to the initial position, the armature 95 is excited by the magnetic field generated by the coil 98. The excited armature 95 receives a force from the magnetic field generated by the magnetic pole 99 and moves the flapper 96 connected to the lower side of the armature 95. The flapper 96 is movable together with the armature 95 and closes the right side of the flow path 92a that is developed left and right. At this time, the hydraulic pressure on the downstream side of the orifice 92b changes on the left and right. That is, the hydraulic pressure on the right side where the flapper 96 approaches increases, and the hydraulic pressure on the left side where the flapper 96 moves away decreases. As a result, the spool 93 is displaced to the left by the hydraulic pressure against the restoring force of the spring 97 (the state shown in FIG. 5B). When the spool 93 is displaced to the left, the supply port 94b and the control port 94c are opened, and a flow path is formed between the supply port 94b and the control port 94c. The hydraulic oil 81 sequentially passes through a hydraulic pressure generator (not shown) and the servo valve 90 through this flow path, and is introduced into the working chamber 72a. At the same time, when the return port 94d and the control port 94e are opened, a flow path is formed between the return port 94d and the control port 94e. The drained oil 82 sequentially passes through the working chamber 72a and the servo valve 90 through this flow path, and is returned to a hydraulic pressure generator (not shown).

  On the other hand, when a signal for instructing the coil 98 to return to the initial position is transmitted from the control signal 100, the armature 95 and the flapper 96 move in a direction of decreasing the inclination. As a result, the blocked left channel 92a is opened again, and the hydraulic pressure acting on the spool 93 is reduced. When the restoring force of the spring 97 becomes larger than the hydraulic pressure, the spool 93 moves to return to the initial position by the restoring force, and closes each port.

  In this series of flows, the servo valve 90 receives the signal from the control device 100 and displaces the spool 93 to change the opening degree of each port. As a result, the servo valve 90 adjusts the balance between the flow rate of the hydraulic oil 81 introduced into the working chamber 72a and the flow rate of the drained oil 82 discharged from the working chamber 72a, and controls the opening degree of the valve body 71.

(First embodiment)
Next, the steam valve driving device according to the first embodiment will be described. In addition, description is abbreviate | omitted about the location similar to a comparative example. FIG. 2 is a diagram illustrating the configuration of the steam valve driving device according to the first embodiment. The steam valve drive device 30 according to the first embodiment is connected to the steam valve 20 and includes a servo valve 40 (control valve), a servo valve 50 (control valve), and a control device 60. The steam valve 20 is a general term for the main steam stop valve 11 and the steam control valve 12. In the steam valve drive device 30 according to the first embodiment, the steam valve 20 is provided with a plurality of servo valves in parallel, and the steam turbine is continuously operated even if any of the servo valves is found to be incompatible. Servo valve can be repaired or replaced.

  The steam valve 20 is provided at the steam inlet of at least one of the high-pressure turbine 3 and the low-pressure turbine 5 in the flow path through which the steam flows. When the steam valve 20 is the steam control valve 12, the opening degree is adjusted by opening and closing the valve body 21 to adjust the amount of steam introduced into the turbine. When the steam valve 20 is the main steam stop valve 11, Fully open or fully closed to permit (full open) or shut off (fully closed) steam introduction.

  The steam valve driving device 30 can replace the servo valve 40 or the servo valve 50 with the valve body 21 open. The steam valve driving device 30 is connected to the hydraulic cylinder device 22 and has a flow path of hydraulic oil 31 that drives the hydraulic cylinder device 22 from a hydraulic pressure generator (not shown), and a tank (not shown) from the hydraulic cylinder device 22. In addition to the flow path of the drained oil 32 (discharged hydraulic oil) discharged toward (no), a bypass flow path 33 branched from the flow path of the drained oil 32 is provided. The connection of the steam valve drive device 30 to the hydraulic cylinder device 22 is preferably connected via a flow path, but is not limited by the connection method. The bypass flow path 33 branches from between the servo valve 40 and the shutoff valves 41a to 41e and between the servo valve 50 and the shutoff valves 51a to 51e and is connected to the flow path of the drained oil 32. 36, a check valve (not shown) and a stop valve (not shown) are installed. A check valve (not shown) is provided to prevent the backflow of the drained oil 32. A stop valve (not shown) is provided for sequentially venting air from the new servo valve 40 or 50 after replacement through the flow path of the drained oil 32.

  During the rated operation, the throttle valves 34 and 36 are in a fully closed state. When the servo valve 40 is replaced, the throttle valve 34 is opened by a signal from the control device 60 and the servo valve 50 is replaced. Is operated to open the throttle valve 36 in response to a signal from the control device 60. By opening the throttle valve 34 or 36, the oil filled in the servo valve 40 or the servo valve 50 is discharged. During this time, the opening degree of the valve body 21 is controlled via the other servo valve. When a turbine trip occurs, the hydraulic oil 31 is discharged as exhaust oil 32 from the working chamber 22a via a trip circuit (not shown).

  The servo valve 40 and the servo valve 50 are provided in parallel to the hydraulic cylinder device 22 through the flow path of the hydraulic oil 31 and the flow path of the drain oil 32, and the hydraulic cylinder apparatus 22 is supplied from a hydraulic pressure generator (not shown). It controls the flow of the hydraulic oil 31 to be driven and the flow of the exhaust oil 32 discharged from the working chamber 22a. Of the servo valve 40 and the servo valve 50, the servo valve in which incompatibility has occurred is the first control valve, and the other servo valve is the second control valve. The configuration of the servo valve 40 and the servo valve 50 and the method of supplying the hydraulic oil 31 to the steam valve 20 are the same as those of the servo valve 90.

  The shutoff valves 41 a to 41 e and the shutoff valves 51 a to 51 e are connected to the servo valve 40 and the servo valve 50. The connection here includes not only the case of being directly connected to the servo valve 40 and the servo valve 50 but also the case of being connected via the flow path of the hydraulic oil 31 and the flow path of the exhaust oil 32. Of the shut-off valves 41a to 41c and the shut-off valves 51a to 51c, the first shut-off valve is connected to the servo valve in which incompatibility has occurred, and the other is the third shut-off valve. The shut-off valves 41d and 41e and the shut-off valves Of 51d and 51e, the second shut-off valve is connected to the servo valve in which the nonconformity occurs, and the other is the fourth shut-off valve. Of the first to fourth shut-off valves, the flow path connected to the hydraulic cylinder device 22 side is indicated by a bold line. When a non-conformance occurs in either one of the servo valve 40 or the servo valve 50, the shut-off valves 41a to 41e or the shut-off valves 51a to 51e operate to fully close the valve body, and the servo valve in which the non-conformance has occurred is hydraulically operated. Shut off from the cylinder device 22. This fully closing operation is performed after a signal is transmitted from the control device 60 to the shutoff valves 41a to 41e or the shutoff valves 51a to 51e.

  The control device 60 receives the opening degree of the valve body 21 from the opening degree detector 25 as an electrical signal. In addition, the control device 60 provides signals for controlling the flow of the hydraulic oil 31 introduced from the steam valve driving device 30 to the working chamber 22a and the flow of the exhaust oil 32 discharged from the working chamber 22a to the steam valve driving device 30. It transmits to the steam valve drive device 30. In particular, during rated operation, the servo valve 40 and the servo valve 50 are both open, and the controller 60 controls the servo valve 40 so that the opening degree of the valve body 21 received from the opening degree detector 25 is constant. And the servo valve 50 is controlled.

  Next, an operation method of the steam valve driving device when a nonconformity occurs in one servo valve will be described with reference to FIG. FIG. 3 is a flow showing an operation procedure when a nonconformity occurs in one of the servo valves in the steam valve driving device according to the first embodiment. The steam valve driving device 30 confirms the soundness of the operation of the servo valve 40 and the servo valve 50 in a valve test that is periodically performed during steady operation. In this valve test, the control device 60 instructs the servo valve 40 or the servo valve 50 to move the other servo valve while keeping the one servo valve at the initial position. When the valve body 21 moves following this instruction, it is determined that the servo valve instructed to move is not incompatible. If the valve body 21 does not follow this instruction, it is determined that the servo valve instructed to move is incompatible (S1). Immediately after determining the nonconformity of the servo valve, the control device 60 instructs to cancel the operation of the servo valve maintained at the initial position.

(1) When nonconformity occurs in the servo valve 40 (when the first control valve is the servo valve 40)
When non-conformity occurs in the servo valve 40, after the operation for maintaining the servo valve 50 at the initial position is canceled, the shutoff valves 41a to 41e are fully closed from the control device 60 to the shutoff valves 41a to 41e. A signal to be operated is transmitted, and the fully closed operation is performed (S2). Until the servo valve 40 is restored, the opening degree of the valve body 21 of the steam valve 20 is adjusted using only the servo valve 50. Further, the control device 60 transmits a signal for opening the throttle valve 34 to the throttle valve 34 of the bypass flow path 33, and the operation of opening the throttle valve 34 is performed. Then, the oil filled between the servo valve 40 and the shutoff valves 41a to 41e passes through the bypass flow path 33 from each port and is discharged as the drained oil 32 (S3). At this time, the pressure in the bypass channel 33 is displayed by the pressure gauge 35. Based on the pressure displayed by the pressure gauge 35, it is confirmed that there is no outflow or ejection of the hydraulic oil 31. After this confirmation, a signal for fully closing the throttle valve 34 is transmitted from the control device 60 to the throttle valve 34, and the throttle valve 34 is fully closed. After performing the above-described process, the servo valve 40 in which the nonconformity has occurred is repaired or replaced with a normal servo valve 40 (S4). After repair or replacement, a signal for operating the shut-off valves 41a to 41e to be fully opened is transmitted again from the control device 60 to the shut-off valves 41a to 41e, and the full-close operation of the shut-off valves 41a to 41e is released (S5). ). As a result, the hydraulic oil 31 is supplied to the servo valve 40 and the servo valve 40 is restored.

  On the other hand, when the nonconformity does not occur in the servo valve 40, the valve test of the servo valve 50 is performed or the valve test is terminated. When ending the valve test, the servo valve is not replaced and the operation is continued (S6).

(2) When non-conformance occurs in the servo valve 50 When non-conformance occurs in the servo valve 50, the signal from the control device 60 when the inconvenience occurs in the servo valve 40 is a signal to the shut-off valves 41a to 41e. May be transmitted to the shutoff valves 51a to 51e and a signal to the throttle valve 34 may be transmitted to the throttle valve 36, respectively. Further, the pressure in the bypass channel 33 may be confirmed with a pressure gauge 37. Thereby, the servo valve 50 is restored in the same manner as the servo valve 40.

  According to the first embodiment described above, even when an abnormality occurs in the servo valve 40 or the servo valve 50, repair or replacement can be performed without fully closing the steam valve 20, and the steam turbine can be continuously operated. Since the servo valve can be repaired or replaced without fully closing the steam valve 20, maintenance time and cost can be reduced. Moreover, since it is not necessary to fully close the steam valve 20, it is applicable not only when the steam valves are multiplexed but also when there is a single steam valve.

(Second embodiment)
Next, the steam valve driving device according to the second embodiment will be described. A description of parts similar to those in the first embodiment is omitted. The difference from the steam valve drive device according to the first embodiment is that an electromagnetic valve is used as a control valve instead of a servo valve. The solenoid valve permits or shuts off the supply of hydraulic oil to the working chamber according to a signal from the control device, and controls the opening of the valve body to be in a fully open (permitted) or fully closed (shut off) state. Other configurations of the steam valve driving device according to the second embodiment are the same as those of the first embodiment.

  According to the second embodiment described above, the electromagnetic valve has the same effect as the first embodiment.

  In the first and second embodiments, the case where there are two servo valves or solenoid valves is described, but the number of servo valves or solenoid valves is not limited.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1. 1. Steam turbine power generation equipment, Boiler, 3. High pressure turbine, 4. 4. Reheater, Low pressure turbine, 6. Condenser, 7. Water pump, 11. Main steam stop valve, 12. Steam control valve, 20. Steam valve, 21. Valve body, 22. Hydraulic cylinder device, 22a. Working chamber, 22b. Non-working chamber, 23. Piston, 24. Spring, 25. Opening detector 30. Steam valve driving device 31. Hydraulic oil, 32. Oil drain, 33. Bypass channel, 34. Throttle valve, 35. Pressure gauge, 36. Throttle valve, 37. Pressure gauge, 40. Servo valves, 41a-41e. Shut-off valve, 44a. Pilot port, 44b. Supply port, 44c. Control port, 44d. Return port, 44e. Control port, 50. Servo valves 51a-51e. Shut-off valve, 54a. Pilot port, 54b. Supply port, 54c. Control port, 54d. Return port, 54e. Control port, 60. Control device, 70. Steam valve, 71. Valve body, 72. Hydraulic cylinder device, 72a. Working chamber, 72b. Non-working chamber, 73. Piston, 74. Spring, 75. Opening detector, 80. 81. steam valve drive device, Hydraulic oil, 82. Oil draining, 90. Servo valve, 92. Flow path, 93. Spool, 94a. Pilot port, 94b. Supply port, 94c. Control port, 94d. Return port, 94e. Control port, 95. Armature, 96. Flapper, 97. Spring, 98. Coil, 99. Magnetic pole, 100. Control device

Claims (4)

A steam valve drive device for controlling the amount of steam introduced into the steam turbine, the steam valve having a valve body and a hydraulic cylinder device for adjusting the opening of the valve body, In the steam valve driving device that controls the amount of steam by adjusting the opening of the valve body by the amount of hydraulic oil supplied to the hydraulic cylinder device,
A control device for controlling the amount of the hydraulic oil supplied to the hydraulic cylinder device;
A first control valve for controlling the amount of the hydraulic oil supplied to the hydraulic cylinder device by a signal from the control device;
A second control valve which is provided in parallel with the first control valve and controls the amount of the hydraulic oil supplied to the hydraulic cylinder device;
A first shut-off valve that shuts off the supply of the hydraulic oil to the first control valve and the discharge of the hydraulic oil from the first control valve;
A second shut-off valve that shuts off the supply of the hydraulic oil from the first control valve to the hydraulic cylinder device and the discharge of the hydraulic oil from the hydraulic cylinder device to the first control valve;
A third shut-off valve that shuts off the supply of the hydraulic oil to the second control valve and the discharge of the hydraulic oil from the second control valve;
A fourth shut-off valve that shuts off the supply of the hydraulic oil from the second control valve to the hydraulic cylinder device and the discharge of the hydraulic oil from the hydraulic cylinder device to the second control valve;
The hydraulic fluid is branched from between the first control valve and the first and second cutoff valves, and is branched from between the second control valve and the third and fourth cutoff valves. A bypass flow path for discharging
Comprising
The steam valve driving device is configured to supply the hydraulic oil supplied to the hydraulic cylinder device using the second control valve in response to a signal from the control device when a nonconformity occurs in the first control valve. Control the amount and continue operation of the steam valve,
Close the first and second shut-off valves, pass hydraulic fluid between the first and second shut-off valves and the first control valve and in the first control valve through the bypass flow path. Steam valve drive device to discharge. The steam valve is a steam stop valve or a steam control valve,
2. The steam valve drive device according to claim 1, wherein the first and second control valves are servo valves that control an amount of the hydraulic oil to adjust an opening degree of the steam valve. The steam valve is a steam stop valve;
2. The steam valve driving device according to claim 1, wherein the first and second control valves are electromagnetic valves that permit or block the supply of the hydraulic oil to a hydraulic cylinder device of the steam stop valve. In order to control the amount of steam introduced into the steam turbine, a valve body that moves and adjusts the opening of the steam inlet;
A piston connected to the valve body;
A spring which is arranged so as to spirally cover the axis of the piston and which moves the valve body in a closing direction;
A hydraulic cylinder device that houses the piston, introduces hydraulic oil into a working chamber, and moves the piston by hydraulic pressure of the hydraulic oil against a restoring force of the spring;
The said hydraulic cylinder apparatus is a steam valve connected with the steam valve drive device in any one of Claim 1 to 3.

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