Steam valve drive device

Abstract

To provide a steam valve drive device that can improve the stability of the trip function. [Solution] In the steam valve drive device according to this embodiment, the first accumulator is connected to a second line branched from a first line supplying hydraulic fluid to the control valve, and is filled with hydraulic fluid under pressure. A closed-side dump valve is connected to a third line branched from the second line, and blocks or allows the flow of hydraulic fluid from the first accumulator to the closed-direction chamber of the cylinder. An accumulator check valve is located in the second line between the branching point of the second line from the first line and the branching point of the third line from the second line. The accumulator check valve blocks the flow of hydraulic fluid from the first accumulator to the first line.

Description

Technical Field

[0001] Embodiments of the present invention relate to a steam valve drive device.

Background Art

[0002] A steam valve that controls the supply of steam to a steam turbine is driven to open and close by a steam valve drive device. Such a steam valve drive device is applied with a fail-safe mechanism that uses a closing spring that constantly applies a spring force in the closing direction of the steam valve. However, problems with adopting a closing spring include deterioration of overspeed characteristics due to an increase in cylinder volume to counteract the closing spring. To improve this point, a fail-safe mechanism that applies a spring force to the cylinder only during an emergency (or trip) is known. Also, a fail-safe mechanism that does not adopt a closing spring is known. When a closing spring is not adopted, the cylinder volume can be reduced, and miniaturization of the steam valve drive device is expected. In a steam valve drive device that does not adopt a closing spring, a double-acting type cylinder that can drive a piston in both the opening direction and the closing direction by hydraulic pressure is adopted.

[0003] An example of such a steam valve drive device is shown in Figure 10. In the example of the steam valve drive device 100 shown in Figure 10, when a trip occurs, the trip solenoid valve 101 discharges emergency oil. As a result, the X ports of the pilot check valves 102 to 104 are released from the pressure of the emergency oil, and the pilot check valves 102 to 104 each function as check valves. Pilot check valve 102 blocks the flow of control oil from the open chamber 106 of the cylinder 105 to the servo valve 107, and pilot check valve 103 blocks the flow of control oil from the closed chamber 108 of the cylinder 105 to the servo valve 107. Pilot check valve 104 blocks the flow of control oil from the servo valve 107 to the open chamber 106. In addition, as the emergency oil is discharged, the dump valve 109 opens, and the control oil in the open chamber 106 is rapidly discharged. When the pilot port of the shut-off valve 110 is released from the pressure of the emergency oil, control oil is rapidly supplied from the accumulator 111 to the closing chamber 108, causing the piston 112 of the cylinder 105 to move in the closing direction. As a result, the steam valve 1 can be rapidly closed. In this way, a fail-safe mechanism that does not employ a closing spring is established.

[0004] In addition to its operation during tripping, the accumulator 111 also has the function of preventing the control oil line formed within the steam valve drive unit 100 from being affected by pulsation or a drop in hydraulic pressure in the control oil supply system during normal operation or when the supply of control oil is interrupted. However, if the pressure of the control oil filled in the accumulator 111 decreases, the amount of control oil filled in the accumulator 111 may decrease. This could lead to a decrease in the tripping function, potentially preventing the tripping operation from being performed correctly. Alternatively, if the servo valve 107 sticks and becomes stiff in the reset position during tripping, it may become difficult to shut off the supply of control oil to the open chamber 106. In this case, the flow of control oil from the servo valve 107 to the open chamber 106 is permitted, and the discharge of control oil from the open chamber 106 to the dump valve 109 is delayed. This can cause delays in the discharge of control oil from the open chamber 106, potentially impairing the tripping function.

[0005] Therefore, the steam valve drive system is required to reliably perform the trip function. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-148196 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] This invention has been made with these points in mind, and aims to provide a steam valve drive device that can improve the stability of the trip function. [Means for solving the problem]

[0008] The steam valve drive device according to this embodiment is a device for opening and closing a steam valve. The steam valve drive device includes a cylinder, a control valve, a first accumulator, a closed-side dump valve, and an accumulator check valve. The cylinder includes an open-direction chamber to which hydraulic fluid is supplied when reset and a closed-direction chamber to which hydraulic fluid is supplied when tripped. The control valve allows or blocks the flow of hydraulic fluid to the open-direction chamber and allows or blocks the discharge of hydraulic fluid from the closed-direction chamber. The first accumulator is connected to a second line branched from a first line supplying hydraulic fluid to the control valve and fills with hydraulic fluid under pressure. The closed-side dump valve is connected to a third line branched from the second line and blocks or allows the flow of hydraulic fluid from the first accumulator to the closed-direction chamber. The accumulator check valve is located in the second line between the branching point of the second line from the first line and the branching point of the third line from the second line. The accumulator check valve blocks the flow of hydraulic fluid from the first accumulator to the first line.

[0009] The steam valve drive device according to this embodiment is a device for opening and closing a steam valve. The steam valve drive device includes a cylinder, a control valve, a first accumulator, a closed-side dump valve, a trip solenoid valve, an open-side pilot check valve, and an open-side dump valve. The cylinder includes an open-direction chamber to which hydraulic fluid is supplied when reset and a closed-direction chamber to which hydraulic fluid is supplied when tripped. The control valve allows or blocks the flow of hydraulic fluid to the open-direction chamber and allows or blocks the discharge of hydraulic fluid from the closed-direction chamber. The first accumulator is connected to a second line branched from a first line supplying hydraulic fluid to the control valve and fills with hydraulic fluid under pressure. The closed-side dump valve is connected to a third line branched from the second line and blocks or allows the flow of hydraulic fluid from the first accumulator to the closed-direction chamber. The trip solenoid valve is connected to a fourth line branched from the second line and controls the closed-side dump valve. The open-side pilot check valve is located in the fifth line connecting the control valve and the open chamber, and is controlled by a trip solenoid valve. The open-side dump valve is connected to the sixth line, which branches off from the portion of the fifth line between the open-side pilot check valve and the open chamber. The open-side dump valve is controlled by a trip solenoid valve to shut off or allow the discharge of hydraulic fluid from the open chamber. The open-side pilot check valve allows the flow of hydraulic fluid from the control valve to the open chamber when reset, and shuts off the flow of hydraulic fluid from the control valve to the open chamber when tripped. [Effects of the Invention]

[0010] According to the present invention, the stability of the trip function can be improved. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a diagram showing the reset state of the steam valve drive device according to the first embodiment. [Figure 2] Figure 2 is a system diagram showing the tripped state of the steam valve drive unit in Figure 1. [Figure 3] Figure 3 is a diagram showing the reset state of the steam valve drive device according to the second embodiment. [Figure 4]Figure 4 is a diagram showing the tripped state of the steam valve drive unit in Figure 3. [Figure 5] Figure 5 is a system diagram showing a steam valve drive device according to the third embodiment. [Figure 6] Figure 6 is a diagram showing a steam valve drive device according to the fourth embodiment. [Figure 7] Figure 7 is a system diagram showing a steam valve drive device according to the fifth embodiment. [Figure 8] Figure 8 is a diagram showing a steam valve drive device according to the sixth embodiment. [Figure 9] Figure 9 is a system diagram showing a steam valve drive device according to the seventh embodiment. [Figure 10] Figure 10 is a diagram showing the reset state of a typical steam valve drive system. [Modes for carrying out the invention]

[0012] The steam valve drive device according to an embodiment of the present invention will be described below with reference to the drawings.

[0013] (First Embodiment) The steam valve drive device 10 in the first embodiment will be described with reference to Figures 1 and 2. The steam valve drive device 10 shown here is a hydraulic drive device for opening and closing the steam valve 1.

[0014] The steam valve 1 is configured to control the flow rate of steam supplied to a steam turbine (not shown). The steam valve 1 includes a valve body 2 and a valve stem 3 (not shown). The valve body 2 is connected to a piston 21 of the steam valve drive unit 10 via the valve stem 3 and is movable toward and toward a valve seat formed in a casing (not shown). While the steam valve 1 is open, the valve body 2 is separated from the valve seat, and while the steam valve 1 is closed, the valve body 2 is in contact with the valve seat. The configuration of the steam valve 1 to which the steam valve drive unit 10 according to this embodiment can be applied is not limited to the configuration shown in Figure 1, etc., and is arbitrary.

[0015] As shown in FIG. 1, the steam valve drive device 10 according to the present embodiment includes a cylinder 20 that operates in response to the pressure of control oil, and a manifold block 30 that supplies the control oil to the cylinder 20. The control oil is an example of hydraulic oil.

[0016] The cylinder 20 according to the present embodiment is a double-acting type cylinder that can drive the piston 21 in both the opening direction and the closing direction by hydraulic pressure. The cylinder 20 includes a piston 21, an opening direction chamber 22, and a closing direction chamber 23. The piston 21 is configured to be slidable within the internal space of the cylinder 20 and is connected to the valve body 2 of the steam valve 1. The opening direction chamber 22 is configured such that control oil is supplied thereto during resetting to apply the pressure of the control oil to the piston 21. Resetting means opening the steam valve 1. The opening direction chamber 22 includes an a-port, to which a fifth line 55 described later is connected. The closing direction chamber 23 is configured such that control oil is supplied thereto during tripping to apply the pressure of the control oil to the piston 21. Tripping means rapidly closing the steam valve 1. The closing direction chamber 23 includes a b-port, to which a seventh line 57 described later is connected.

[0017] The manifold block 30 may include a supply port 31, a discharge port 32, a servo valve 33, a first accumulator 34, a closing side dump valve 35, an accumulator check valve 36, a trip solenoid valve 37, a flow rate limiting section 38 for emergency oil, an opening side pilot check valve 39, an opening side dump valve 40, and a closing side pilot check valve 41.

[0018] The supply port 31 is connected to the control oil supply system, and the control oil is supplied from the control oil supply system. The discharge port 32 is connected to the drain system and is configured to discharge the control oil and emergency oil (described later) to the drain system.

[0019] The servo valve 33 is configured to allow or block the flow of control oil to the open-direction chamber 22. The servo valve 33 is an example of a control valve. The first line 51 is connected to the P port of the servo valve 33. The first line 51, like each of the lines described later, is a flow path for oil. The first line 51 connects the supply port 31 to the P port of the servo valve 33, and control oil is supplied from the supply port 31 to the P port of the servo valve 33 through the first line 51. The A port of the servo valve 33 is connected to the a port of the open-direction chamber 22 via the fifth line 55, which will be described later. The B port of the servo valve 33 is connected to the b port of the closed-direction chamber 23 via the seventh line 57, which will be described later.

[0020] The servo valve 33 is also configured to allow or block the discharge of control oil from the closing chamber 23. As shown in Figure 1, the servo valve 33 allows the discharge of control oil from the closing chamber 23 when it allows the flow of control oil to the opening chamber 22. As shown in Figure 2, the servo valve 33 blocks the discharge of control oil from the closing chamber 23 when it blocks the flow of control oil to the opening chamber 22. A first drain line 61 is connected to the T port of the servo valve 33. The first drain line 61 may also connect the T port of the servo valve 33 to the B port of the open-side dump valve 40, which will be described later. A first drain check valve 42 is located on the first drain line 61 to prevent pressure from the drain oil (described later) from being applied to the T port of the servo valve 33.

[0021] The servo valve 33 is configured to allow or block the flow of control oil to the open chamber 22 based on a command from a control device (not shown). More specifically, when a reset command signal is input to the servo valve 33, as shown in Figure 1, the P port and the A port communicate with each other, and the T port and the B port communicate with each other. In this case, the servo valve 33 allows the flow of control oil to the open chamber 22 and also allows the discharge of control oil from the closed chamber 23. On the other hand, when a trip command signal is input to the servo valve 33, as shown in Figure 2, the P port and the B port communicate with each other, and the T port and the A port communicate with each other. In this case, the servo valve 33 blocks the flow of control oil to the open chamber 22 and also blocks the discharge of control oil from the closed chamber 23. During a trip, the servo valve 33 allows the discharge of control oil from the open chamber 22 and also allows the flow of control oil to the closed chamber 23.

[0022] The first accumulator 34 is configured to be filled with control oil under pressure. The second line 52, which branches off from the first line 51, is connected to the first accumulator 34. The second line 52 connects the first accumulator 34 to the branching point P1 of the second line 52 from the first line 51. Control oil is supplied to the first accumulator 34 from the supply port 31 through the first line 51 and the second line 52. The first accumulator 34 may be a piston-type accumulator (see reference numeral 75 in Figure 6) that includes an accumulator piston that separates the control oil from the gas. Alternatively, the first accumulator 34 may be a bladder-type accumulator (see reference numeral 77 in Figure 7) that includes a bladder that separates the control oil from the gas.

[0023] The closed-side dump valve 35 is configured to block or allow the flow of control oil from the first accumulator 34 to the closing-direction chamber 23. A third line 53, which branches off from the second line 52, is connected to port A of the closed-side dump valve 35. The third line 53 connects port A of the closed-side dump valve 35 to the branching point P2 of the third line 53 from the second line 52. An eighth line 58, described later, is connected to port B of the closed-side dump valve 35. The eighth line 58 merges with the seventh line 57, described later, and is connected to port b of the closing-direction chamber 23 via the seventh line 57.

[0024] The closed-side dump valve 35 is controlled by a trip solenoid valve 37, which will be described later. An emergency oil line 59 is connected to the X port of the closed-side dump valve 35. The closed-side dump valve 35, under the control of the trip solenoid valve 37, blocks or allows the flow of control oil from the first accumulator 34 to the closing-direction chamber 23. When reset, as shown in Figure 1, emergency oil is supplied from the trip solenoid valve 37 to the X port of the closed-side dump valve 35, and the X port is subjected to the pressure of the emergency oil. As a result, the closed-side dump valve 35 closes, blocking the flow of control oil from the first accumulator 34 to the closing-direction chamber 23. When tripped, as shown in Figure 2, the emergency oil is discharged into the drain system, and the X port of the closed-side dump valve 35 is released from the pressure of the emergency oil. As a result, when tripped, the closed-side dump valve 35 opens, allowing the flow of control oil from the first accumulator 34 to the closing-direction chamber 23.

[0025] The accumulator check valve 36 is configured as a check valve that blocks the flow of control oil from the first accumulator 34 to the first line 51. The accumulator check valve 36 is located in the second line 52. In the second line 52, the accumulator check valve 36 is located between the branching point P1 of the second line 52 from the first line 51 and the branching point P2 of the third line 53 (described later) from the second line 52. The accumulator check valve 36 is configured to allow the flow of control oil from the first line 51 to the first accumulator 34.

[0026] The trip solenoid valve 37 is configured to control the closed-side dump valve 35, the open-side pilot check valve 39, the open-side dump valve 40, and the closed-side pilot check valve 41. A fourth line 54, which branches off from the second line 52, is connected to the P port of the trip solenoid valve 37. The fourth line 54 branches off from the portion between the branching point P2 of the third line 53 from the second line 52 and the first accumulator 34. The fourth line 54 connects the P port of the trip solenoid valve 37 to the branching point P3 of the fourth line 54 from the second line 52. Control oil is supplied to the P port of the trip solenoid valve 37 from the supply port 31 through the first line 51, the second line 52, and the fourth line 54.

[0027] An emergency oil line 59 is connected to port A of the trip solenoid valve 37, and port A of the trip solenoid valve 37 is connected to port X of the closed dump valve 35, port X of the open pilot check valve 39, port X of the open dump valve 40, and port X of the closed pilot check valve 41. The emergency oil line 59 includes three branching points and branches into three lines. The control oil supplied from port A of the trip solenoid valve 37 to the emergency oil line 59 is called emergency oil. The emergency oil is supplied to port X of the closed dump valve 35, port X of the open pilot check valve 39, port X of the open dump valve 40, and port X of the closed pilot check valve 41, respectively.

[0028] A second drain line 62 is connected to the T port of the trip solenoid valve 37. The second drain line 62 may also connect the T port of the trip solenoid valve 37 to the B port of the open-side dump valve 40, which will be described later. A second drain check valve 43 is located in the second drain line 62 to prevent pressure from the drain oil (described later) from being applied to the T port of the trip solenoid valve 37.

[0029] The trip solenoid valve 37 is configured to control the closed-side dump valve 35, the open-side pilot check valve 39, the open-side dump valve 40, and the closed-side pilot check valve 41 based on commands from a control device (not shown). More specifically, when a reset command signal is input to the trip solenoid valve 37, the trip solenoid valve 37 is energized, and as shown in Figure 1, the P port and the A port communicate. In this case, the trip solenoid valve 37 allows the flow of emergency oil to the emergency oil line 59. This applies emergency oil pressure to the X port of the closed-side dump valve 35, the X port of the open-side pilot check valve 39, the X port of the open-side dump valve 40, and the X port of the closed-side pilot check valve 41. On the other hand, when a trip command signal is input to the trip solenoid valve 37, the trip solenoid valve 37 is de-energized, and as shown in Figure 2, the A port and the T port communicate. In this case, the flow of emergency oil to the emergency oil line 59 is shut off, and the discharge of emergency oil from the emergency oil line 59 is permitted. As a result, the X port of the closed-side dump valve 35, the X port of the open-side pilot check valve 39, the X port of the open-side dump valve 40, and the X port of the closed-side pilot check valve 41 are released from the pressure of the emergency oil.

[0030] The emergency oil flow limiting unit 38 may be located in the fourth line 54. The emergency oil flow limiting unit 38 is located between the branching point P3 of the fourth line 54 from the second line 52 and the trip solenoid valve 37. The emergency oil flow limiting unit 38 is configured to limit the flow rate of control oil through the fourth line 54. The emergency oil flow limiting unit 38 has the function of reducing surge pressure caused by the closure of the emergency oil line 59 when reset. The emergency oil flow limiting unit 38 may be composed of an orifice or a flow control valve.

[0031] The open-side pilot check valve 39 is configured to allow or block the flow of control oil from the servo valve 33 to the open-direction chamber 22. The open-side pilot check valve 39 is located in a fifth line 55 that connects the servo valve 33 and the open-direction chamber 22. The fifth line 55 connects port A of the servo valve 33 to port a of the open-direction chamber 22.

[0032] The open-side pilot check valve 39 is controlled by the trip solenoid valve 37. An emergency oil line 59 is connected to the X port of the open-side pilot check valve 39. When reset, as shown in Figure 1, emergency oil is supplied from the trip solenoid valve 37 to the X port of the open-side pilot check valve 39, and the X port is subjected to the pressure of the emergency oil. This allows the open-side pilot check valve 39 to allow the flow of control oil from the servo valve 33 to the open-direction chamber 22. When tripped, as shown in Figure 2, the emergency oil is discharged into the drain system, and the X port of the open-side pilot check valve 39 is released from the pressure of the emergency oil. As a result, when tripped, the open-side pilot check valve 39 functions as a check valve and blocks the flow of control oil from the servo valve 33 to the open-direction chamber 22. When tripped, the open-side pilot check valve 39 allows the flow of control oil from the open-direction chamber 22 to the servo valve 33.

[0033] Each port of the open-side pilot check valve 39 is closed when reset, which helps to equalize the pressure at each port of the open-side pilot check valve 39. For this reason, the third drain line 63 may be connected to the Y port of the open-side pilot check valve 39. The third drain line 63 may connect the Y port of the open-side pilot check valve 39 to the B port of the open-side dump valve 40, which will be described later.

[0034] The open-side dump valve 40 is configured to shut off or allow the discharge of control oil from the open-direction chamber 22. A sixth line 56, which branches off from the fifth line 55, is connected to port A of the open-side dump valve 40. The sixth line 56 branches off from the portion of the fifth line 55 between the open-side pilot check valve 39 and the open-direction chamber 22. The sixth line 56 connects port A of the open-side dump valve 40 to the branching point P4 of the sixth line 56 from the fifth line 55. A fourth drain line 64 is connected to port B of the open-side dump valve 40. The fourth drain line 64 connects port B of the open-side dump valve 40 to the outlet 32, and control oil is discharged from the open-side dump valve 40 to the outlet 32 ​​through the fourth drain line 64. The first drain line 61, second drain line 62, and third drain line 63 described above may merge with the fourth drain line 64 at an intermediate position. The control oil and emergency oil discharged to the outlet 32 ​​are collectively referred to as drain oil.

[0035] The open-side dump valve 40 is controlled by a trip solenoid valve 37. An emergency oil line 59 is connected to the X port of the open-side dump valve 40. The open-side dump valve 40 shuts off or allows the discharge of control oil from the open-direction chamber 22 under the control of the trip solenoid valve 37. When reset, as shown in Figure 1, emergency oil is supplied from the trip solenoid valve 37 to the X port of the open-side dump valve 40, and the X port is subjected to the pressure of the emergency oil. As a result, the open-side dump valve 40 closes, shutting off the discharge of control oil from the open-direction chamber 22. When tripped, as shown in Figure 2, the emergency oil is discharged into the drain system, and the X port of the open-side dump valve 40 is released from the pressure of the emergency oil. As a result, when tripped, the open-side dump valve 40 opens, allowing the discharge of control oil from the open-direction chamber 22.

[0036] The closed-side pilot check valve 41 is configured to allow or block the flow of control oil from the closing direction chamber 23 to the servo valve 33. The closed-side pilot check valve 41 is located in the seventh line 57, which connects the servo valve 33 and the closing direction chamber 23. The seventh line 57 connects the B port of the servo valve 33 to the b port of the closing direction chamber 23. The eighth line 58, which is connected to the closed-side dump valve 35 described above, joins the seventh line 57. The eighth line 58 connects the B port of the closed-side dump valve 35 to the portion of the seventh line 57 between the closed-side pilot check valve 41 and the b port of the closing direction chamber 23. The junction of the seventh line 57 and the eighth line 58 is indicated by P5.

[0037] The closed-side pilot check valve 41 is controlled by the trip solenoid valve 37. The emergency oil line 59 is connected to the X port of the closed-side pilot check valve 41. When reset, as shown in Figure 1, emergency oil is supplied from the trip solenoid valve 37 to the X port of the closed-side pilot check valve 41, and the X port is subjected to the pressure of the emergency oil. This allows the closed-side pilot check valve 41 to allow the flow of control oil from the closing direction chamber 23 to the servo valve 33. When tripped, as shown in Figure 2, the emergency oil is discharged into the drain system, and the X port of the closed-side pilot check valve 41 is released from the pressure of the emergency oil. As a result, when tripped, the closed-side pilot check valve 41 functions as a check valve, blocking the flow of control oil from the closing direction chamber 23 to the servo valve 33. When reset, the closed-side pilot check valve 41 allows the flow of control oil from the servo valve 33 to the closing direction chamber 23.

[0038] Next, a method for driving the steam valve 1 in the steam valve drive device 10 according to this embodiment, which has the above configuration, will be explained with reference to Figures 1 and 2.

[0039] When resetting, as shown in Figure 1, a reset command signal is input to the trip solenoid valve 37, which is energized, and the P port and A port are connected. As a result, the control oil supplied to the P port of the trip solenoid valve 37 becomes emergency oil and is supplied to the emergency oil line 59. Emergency oil pressure is applied to the X port of the closed-side dump valve 35, the X port of the open-side pilot check valve 39, the X port of the open-side dump valve 40, and the X port of the closed-side pilot check valve 41. Meanwhile, a reset command signal is also input to the servo valve 33, and the P port and A port are connected, as well as the T port and B port.

[0040] During reset, the open-side pilot check valve 39 allows the flow of control oil from the servo valve 33 to the open-direction chamber 22. As a result, the control oil supplied to the servo valve 33 from the supply port 31 is supplied to the open-direction chamber 22 through the fifth line 55. Consequently, the pressure of the control oil in the open-direction chamber 22 increases.

[0041] On the other hand, the closed-side pilot check valve 41 allows the flow of control oil from the closing-direction chamber 23 to the servo valve 33. As a result, control oil is discharged from the closing-direction chamber 23 to the servo valve 33. The control oil discharged to the servo valve 33 is then discharged through the first drain line 61 to the outlet 32, and the control oil in the closing-direction chamber 23 is discharged.

[0042] In this way, the piston 21 slides under the pressure of the control oil in the opening chamber 22, opening the steam valve 1.

[0043] Incidentally, an accumulator check valve 36 is located in the second line 52, and the accumulator check valve 36 blocks the flow of control oil from the first accumulator 34 to the first line 51. This prevents the control oil that was filled in the first accumulator 34 from being discharged into the first line 51, even if the pressure of the control oil in the first line 51 drops during a reset. Therefore, it is possible to prevent the pressure of the control oil in the first accumulator 34 from dropping and to maintain the trip function of the first accumulator 34.

[0044] Next, we will explain the case where steam valve 1 trips (closes suddenly).

[0045] When tripping occurs, as shown in Figure 2, a trip command signal is input to the trip solenoid valve 37, causing it to become de-energized, and ports A and T connect. This allows the emergency oil in the emergency oil line 59 to be discharged. Port X of the closed-side dump valve 35, port X of the open-side pilot check valve 39, port X of the open-side dump valve 40, and port X of the closed-side pilot check valve 41 are released from the pressure of the emergency oil. Meanwhile, a trip command signal is also input to the servo valve 33, causing ports P and B to connect, and ports T and A to connect.

[0046] During a trip, the closed-side dump valve 35 opens, allowing control oil to flow from the first accumulator 34 to the closing-direction chamber 23. This rapidly supplies the control oil that was filling the first accumulator 34 to the closing-direction chamber 23 through the closed-side dump valve 35, the eighth line 58, and the seventh line 57. As a result, the pressure of the control oil in the closing-direction chamber 23 rapidly increases. The closed-side pilot check valve 41 blocks the flow of control oil from the closing-direction chamber 23 to the servo valve 33. This prevents the control oil supplied from the first accumulator 34 to the seventh line 57 from flowing to the servo valve 33.

[0047] Meanwhile, the open-side dump valve 40 opens, allowing the control oil to be discharged from the open-direction chamber 22. As a result, the control oil is rapidly discharged from the open-direction chamber 22 through the open-side dump valve 40 and the fourth drain line 64 to the outlet 32.

[0048] In this way, the piston 21 receives pressure from the control oil in the closing direction chamber 23 and rapidly closes the steam valve 1.

[0049] Incidentally, the open-side pilot check valve 39 blocks the flow of control oil from the servo valve 33 to the open-direction chamber 22 when it trips. Now, consider the case where the servo valve 33 is stuck in the reset position and the P port is still in communication with the A port even when reset. In this case, the flow of control oil from the A port of the servo valve 33 to the fifth line 55 is permitted. However, the open-side pilot check valve 39 blocks the flow of control oil from the servo valve 33 to the open-direction chamber 22. This prevents control oil from flowing from the servo valve 33 to the branching point P4 of the sixth line 56, and prevents stagnation in the discharge of control oil from the open-direction chamber 22 to the open-side dump valve 40.

[0050] As described above, according to this embodiment, the first accumulator 34 is connected to the second line 52, which branches off from the first line 51 that supplies control oil to the servo valve 33. A closed-side dump valve 35 is connected to the third line 53, which branches off from the second line 52, to block or allow the flow of control oil from the first accumulator 34 to the closed-direction chamber 23. In the second line 52, an accumulator check valve 36 is positioned between the branching point P1 of the second line 52 from the first line 51 and the branching point P2 of the third line 53 from the second line 52. The accumulator check valve 36 blocks the flow of control oil from the first accumulator 34 to the first line 51. As a result, the first accumulator 34 does not need to have a function to prevent pulsation or a drop in oil pressure of the control oil in the control oil supply system. Therefore, a decrease in the pressure of the control oil filled in the first accumulator 34 can be prevented, and the first accumulator 34 can be specialized for the purpose of supplying control oil to the closing chamber 23 during tripping. As a result, the stability of the tripping function can be improved. In addition, since the first accumulator 34 only needs to ensure the amount of control oil supplied to the closing chamber 23, the first accumulator 34 can be made smaller. These effects can be achieved independently of the open-side pilot check valve 39.

[0051] Furthermore, according to this embodiment, an open-side pilot check valve 39 is located on a fifth line 55 connecting the servo valve 33 and the open-direction chamber 22. An open-side dump valve 40 is connected to a sixth line 56 that branches off from the portion of the fifth line 55 between the open-side pilot check valve 39 and the open-direction chamber 22, which either shuts off or allows the discharge of control oil from the open-direction chamber 22. The open-side pilot check valve 39 allows the flow of control oil from the servo valve 33 to the open-direction chamber 22 during reset and shuts off the flow of control oil from the servo valve 33 to the open-direction chamber 22 during trip. This prevents control oil from being supplied from the servo valve 33 to the open-direction chamber 22 even if the servo valve 33 is stuck in the open-direction position and the P port is in communication with the A port during reset. As a result, stagnation of the discharge of control oil from the open-direction chamber 22 to the open-side dump valve 40 can be prevented, and the control oil from the open-direction chamber 22 can be rapidly discharged. This improves the stability of the trip function. Furthermore, these effects can be achieved independently of the accumulator check valve 36 mentioned above.

[0052] (Second Embodiment) Next, a steam valve drive device in a second embodiment of the present invention will be described with reference to Figures 3 and 4.

[0053] In the second embodiment shown in Figures 3 and 4, the control valve is composed of a control solenoid valve, and the main difference is that in the first line, a control oil flow limiting unit capable of limiting the flow rate of control oil is positioned between the branching point of the second line and the control solenoid valve. Other configurations are substantially the same as those of the first embodiment shown in Figures 1 and 2. In Figures 3 and 4, the same reference numerals are used for parts that are the same as those in the first embodiment shown in Figures 1 and 2, and detailed descriptions are omitted.

[0054] As shown in Figures 3 and 4, the control valve according to this embodiment is composed of a control solenoid valve 70. More specifically, the servo valve 33 shown in Figures 1 and 2 is replaced by the control solenoid valve 70. The control solenoid valve 70 is an example of a control valve and is an on / off valve.

[0055] The control solenoid valve 70, like the servo valve 33 shown in Figures 1 and 2, is configured to allow or block the flow of control oil to the open chamber 22. The first line 51 is connected to the P port of the control solenoid valve 70. The A port of the control solenoid valve 70 is connected to the a port of the open chamber 22 via the fifth line 55. The B port of the control solenoid valve 70 is connected to the b port of the closed chamber 23 via the seventh line 57.

[0056] The control solenoid valve 70 is also configured to allow or block the discharge of control oil from the closed-direction chamber 23. The T port of the control solenoid valve 70 is connected to the first drain line 61.

[0057] The control solenoid valve 70 is configured to allow or block the flow of control oil to the open chamber 22 based on a command from a control device (not shown). More specifically, when a reset command signal is input to the control solenoid valve 70, the control solenoid valve 70 is energized, and the P port and A port and the T port and B port are connected. In this case, the control solenoid valve 70 allows the flow of control oil to the open chamber 22 and also allows the discharge of control oil from the closed chamber 23. On the other hand, when a trip command signal is input to the servo valve 33, the control solenoid valve 70 is de-energized, and the P port and B port and the T port and A port are connected. In this case, the servo valve 33 blocks the flow of control oil to the open chamber 22 and also blocks the discharge of control oil from the closed chamber 23. During a trip, the control solenoid valve 70 allows the discharge of control oil from the open chamber 22 and also allows the flow of control oil to the closed chamber 23.

[0058] The flow rate of the control oil supplied to the control solenoid valve 70 is limited by a control oil flow rate limiting unit 71 located in the first line 51. The control oil flow rate limiting unit 71 is located in the first line 51. More specifically, the control oil flow rate limiting unit 71 is located in the first line 51 between the branching point P1 of the second line 52 and the control solenoid valve 70. The control oil flow rate limiting unit 71 may be composed of an orifice or a flow control valve.

[0059] As described above, according to this embodiment, the control oil flow rate limiting unit 71 can limit the flow rate of control oil supplied to the control solenoid valve 70. This allows the flow rate of control oil supplied from the control solenoid valve 70 to the opening chamber 22 to be limited during reset, thereby adjusting the opening time of the steam valve 1.

[0060] (Third embodiment) Next, a steam valve drive device in a third embodiment of the present invention will be described with reference to Figure 5.

[0061] In the third embodiment shown in Figure 5, the main difference is that the steam valve drive device includes a first test solenoid valve that controls the supply and discharge of control oil to the first accumulator, and a first gas pressure measuring instrument that measures the gas pressure in the first accumulator. The other components are substantially the same as those in the first embodiment shown in Figures 1 and 2. In Figure 5, the same reference numerals are used for parts that are the same as those in the first embodiment shown in Figures 1 and 2, and detailed descriptions are omitted.

[0062] As shown in Figure 5, the steam valve drive device 10 according to this embodiment includes a first test solenoid valve 72 and a first gas pressure measuring device 73. The first test solenoid valve 72 and the first gas pressure measuring device 73 constitute a gas filling amount monitoring mechanism.

[0063] The first test solenoid valve 72 is located in the second line 52. More specifically, the first test solenoid valve 72 is located in the second line 52 between the branch point P3 of the fourth line 54 and the first accumulator 34. The first test solenoid valve 72 is configured to control the supply and discharge of control oil to and from the first accumulator 34. The first test solenoid valve 72 is configured to switch between a state in which the first accumulator 34 is in communication with the branch point P3 and a state in which the communication between the first accumulator 34 and the branch point P3 is blocked. The fifth drain line 74 is connected to the first test solenoid valve 72. When the first accumulator 34 is in communication with the branch point P3, the first test solenoid valve 72 is configured to block the communication between the first accumulator 34 and the fifth drain line 74. When the communication between the first accumulator 34 and the branch point P3 is interrupted, the first test solenoid valve 72 is configured to allow communication between the first accumulator 34 and the fifth drain line 74. The fifth drain line 74 may also be connected to the first test solenoid valve 72 and port B of the open-side dump valve 40.

[0064] The first gas pressure measuring instrument 73 is configured to measure the pressure of the gas filled in the first accumulator 34. The configuration of the first gas pressure measuring instrument 73 is arbitrary, as long as it is capable of measuring the pressure of the gas filled in the first accumulator 34.

[0065] When measuring the gas pressure in the first accumulator 34, the first test solenoid valve 72, upon receiving a command from a control device (not shown), shuts off communication between the first accumulator 34 and the branch point P3. In this case, the first accumulator 34 communicates with the fifth drain line 74, and the control oil filled in the first accumulator 34 is discharged to the outlet 32 ​​through the fifth drain line 74.

[0066] After the control oil is discharged from the first accumulator 34, the first gas pressure measuring instrument 73 measures the pressure of the gas filled in the first accumulator 34. When the first accumulator 34 is filled with control oil, the volume of the gas is compressed until the pressure of the control oil and the pressure of the gas balance out, making it difficult to measure the gas pressure. In contrast, in this embodiment, as described above, the pressure of the gas filled in the first accumulator 34 is measured with the control oil discharged from the first accumulator 34. This makes it possible to accurately measure the pressure of the gas inside the first accumulator 34.

[0067] The measured gas pressure may be compared with the initial value of the gas pressure similarly measured in the initial state of the steam valve drive device 10. This allows for confirmation of whether or not there is a gas leak and whether or not sufficient gas pressure is maintained to activate the trip function. As a result, a decrease in the pressure of the control oil filled in the first accumulator 34 can be prevented, and the trip function of the first accumulator 34 can be maintained.

[0068] After the measurement, the first test solenoid valve 72 receives a command from a control device (not shown) and connects the first accumulator 34 to the branch point P3. In this case, control oil is supplied to the first accumulator 34 from the supply port 31 through the first line 51 and the second line 52 and filled. This ensures the trip function of the first accumulator 34.

[0069] As described above, according to this embodiment, in the second line 52, the first test solenoid valve 72, positioned between the branching point P3 of the fourth line 54 and the first accumulator 34, controls the supply and discharge of control oil to the first accumulator 34. This allows the first test solenoid valve 72 to discharge the control oil filled in the first accumulator 34, and the first gas pressure measuring instrument 73 to measure the pressure of the gas filled in the first accumulator 34 while the control oil is discharged. This prevents a drop in the gas pressure in the first accumulator 34, which would impair the trip function of the first accumulator 34. As a result, the amount of gas filled in the first accumulator 34 can be monitored, and the stability of the trip function can be improved. In this case, the steam valve 1 can be kept in a reset state, and the amount of gas filled in the first accumulator 34 can be monitored while the operating state of the steam valve 1 continues.

[0070] Furthermore, according to this embodiment, the amount of gas filled in the first accumulator 34 can be monitored as described above by using the first test solenoid valve 72 and the first gas pressure measuring instrument 73. Therefore, the amount of gas filled can be monitored remotely, and the gas level can be easily and quickly confirmed.

[0071] (Fourth embodiment) Next, a steam valve drive device in the fourth embodiment of the present invention will be described with reference to Figure 6.

[0072] In the fourth embodiment shown in Figure 6, the main difference is that the steam valve drive device includes a piston position measuring device for measuring the position of the accumulator piston of the first accumulator; other configurations are substantially the same as those of the first embodiment shown in Figures 1 and 2. In Figure 6, the same reference numerals are used for parts identical to those of the first embodiment shown in Figures 1 and 2, and detailed descriptions are omitted.

[0073] As shown in Figure 6, the first accumulator 34 in this embodiment is a piston-type accumulator. The first accumulator 34 includes an accumulator piston 75 that separates the control oil from the gas. The position of the accumulator piston 75 indicates the gas volume within the first accumulator 34.

[0074] The steam valve drive device 10 according to this embodiment includes a piston position measuring device 76. The piston position measuring device 76 is configured to measure the position of the accumulator piston 75 of the first accumulator 34. The configuration of the piston position measuring device 76 is arbitrary as long as it can measure the position of the accumulator piston 75. The piston position measuring device 76 constitutes the gas filling amount monitoring mechanism.

[0075] As described above, according to this embodiment, the position of the accumulator piston 75 of the first accumulator 34 can be measured by the piston position measuring instrument 76. The position of the accumulator piston 75 indicates the volume of gas filled in the first accumulator 34. For example, if the pressure of the gas filled in the first accumulator 34 decreases due to a gas leak or the like, the accumulator piston 75 is pushed up by the pressure of the control oil filled in. In this way, the position of the accumulator piston 75 can be measured and the pressure of the gas filled in the first accumulator 34 can be confirmed. Therefore, it is possible to prevent the trip function of the first accumulator 34 from being impaired due to a decrease in the gas pressure inside the first accumulator 34. As a result, the stability of the trip function can be improved by monitoring the amount of gas filled in the first accumulator 34.

[0076] Furthermore, according to this embodiment, the piston position measuring device 76 can measure the position of the accumulator piston 75 of the first accumulator 34. This allows the position of the accumulator piston 75 to be measured even when the first accumulator 34 is filled with control oil. Therefore, it becomes unnecessary to drain the control oil from the first accumulator 34, and the amount of gas filled in the first accumulator 34 can be monitored. In this case, the steam valve 1 can be kept in a reset state, and the amount of gas filled in the first accumulator 34 can be monitored while the operation of the steam valve 1 continues.

[0077] (Fifth embodiment) Next, a steam valve drive device in a fifth embodiment of the present invention will be described with reference to Figure 7.

[0078] In the fifth embodiment shown in Figure 7, the main difference is that the bladder strain measuring instrument measures the strain of the bladder of the first accumulator; the other configurations are substantially the same as those of the first embodiment shown in Figures 1 and 2. In Figure 7, the same reference numerals are used for parts that are the same as those in the first embodiment shown in Figures 1 and 2, and detailed descriptions are omitted.

[0079] As shown in Figure 7, the first accumulator 34 in this embodiment is a bladder-type accumulator. The first accumulator 34 includes a bladder 77 that separates the control oil from the gas. The bladder 77 expands and contracts in response to the pressure of the gas and the control oil filled in the first accumulator 34. When control oil is supplied to the first accumulator 34, the bladder 77 contracts until the gas pressure and the control oil pressure are in equilibrium. If the pressure of the gas filled in the first accumulator 34 decreases due to a gas leak or the like, the bladder 77 contracts.

[0080] The steam valve drive device 10 according to this embodiment includes a bladder strain measuring device 78. The bladder strain measuring device 78 is configured to measure the strain of the bladder 77 of the first accumulator 34. The bladder strain measuring device 78 is capable of measuring the strain of the bladder 77 of the first accumulator 34 when it is filled with control oil. The configuration of the bladder strain measuring device 78 is arbitrary as long as it can measure the strain of the bladder 77. The bladder strain measuring device 78 constitutes a gas filling amount monitoring mechanism.

[0081] As described above, according to this embodiment, the strain of the bladder 77 of the first accumulator 34 can be measured by the bladder strain measuring instrument 78. The strain of the bladder 77 indicates the volume of gas filled in the first accumulator 34. For example, if the pressure of the gas filled in the first accumulator 34 decreases due to a gas leak or the like, the bladder 77 will shrink, and the strain of the bladder 77 will decrease. By comparing the measured strain with the strain when the gas pressure is normal, the pressure of the gas filled in the first accumulator 34 can be confirmed. This prevents the trip function of the first accumulator 34 from being impaired due to a decrease in the gas pressure inside the first accumulator 34. As a result, the stability of the trip function can be improved by monitoring the amount of gas filled in the first accumulator 34.

[0082] Furthermore, according to this embodiment, the bladder strain measuring instrument 78 can measure the strain of the bladder 77 of the first accumulator 34. This allows the strain of the bladder 77 to be measured even when the first accumulator 34 is filled with control oil. Therefore, it is not necessary to drain the control oil from the first accumulator 34, and the amount of gas filled in the first accumulator 34 can be monitored. In this case, the steam valve 1 can be kept in a reset state, and the amount of gas filled in the first accumulator 34 can be monitored while the operation of the steam valve 1 continues.

[0083] (Sixth embodiment) Next, a steam valve drive device in the sixth embodiment of the present invention will be described with reference to Figure 8.

[0084] In the sixth embodiment shown in Figure 8, the main difference is that the steam valve drive device further includes a second accumulator, and a test solenoid valve and a gas pressure measuring instrument are provided on the first and second accumulators, respectively. The other configurations are substantially the same as those of the third embodiment shown in Figure 5. In Figure 8, the same reference numerals are used for parts identical to those in the third embodiment shown in Figure 5, and detailed descriptions are omitted.

[0085] As shown in Figure 7, the steam valve drive device 10 according to this embodiment includes a second accumulator 79, a first test solenoid valve 72, a first gas pressure measuring device 73, a second test solenoid valve 80, and a second gas pressure measuring device 81. The first accumulator 34 and the second accumulator 79 each have their own trip function, and the steam valve 1 can be tripped using either accumulator. In the steam valve drive device 10 according to this embodiment, the trip function is duplicated, and the gas filling amount monitoring mechanism is also duplicated.

[0086] The second accumulator 79 is configured to be filled with control oil under pressure. The second accumulator 79 is connected to an accumulator line 82 that branches off from the second line 52. The accumulator line 82 connects the second accumulator 79 to the branching point of the accumulator line 82 from the second line 52. The branching point of the accumulator line 82 may be the branching point P3 of the fourth line 54 from the second line 52, or it may branch off from a branching point (not shown) located closer to the first accumulator 34 than branching point P3. Control oil is supplied to the second accumulator 79 from the supply port 31 through the first line 51, the second line 52, and the accumulator line 82. The second accumulator 79 may be configured similarly to the first accumulator 34.

[0087] The second test solenoid valve 80 is located in the accumulator line 82. More specifically, the second test solenoid valve 80 is located in the accumulator line 82 between the branching point P3 and the second accumulator 79. The second test solenoid valve 80 is configured to control the supply and discharge of control oil to and from the second accumulator 79. The second test solenoid valve 80 is configured to switch between a state in which the second accumulator 79 is in communication with the branching point P3 and a state in which the communication between the second accumulator 79 and the branching point P3 is blocked. The sixth drain line 83 is connected to the second test solenoid valve. When the second accumulator 79 is in communication with the branching point P3, the second test solenoid valve 80 is configured to block the communication between the second accumulator 79 and the sixth drain line 83. When the communication between the second accumulator 79 and the branching point P3 is interrupted, the second test solenoid valve 80 is configured to allow communication between the second accumulator 79 and the sixth drain line 83. The sixth drain line 83 is connected to the second test solenoid valve 80 and may merge with the fifth drain line 74 at an intermediate position.

[0088] The second gas pressure measuring instrument 81 is configured to measure the pressure of the gas filled in the second accumulator 79. The configuration of the second gas pressure measuring instrument 81 is arbitrary, as long as it is capable of measuring the pressure of the gas filled in the second accumulator 79.

[0089] By using the second test solenoid valve 80 and the second gas pressure measuring device 81 in the same manner as the first test solenoid valve 72 and the first gas pressure measuring device 73, the pressure of the gas filled in the second accumulator 79 can be measured. In this embodiment, a test solenoid valve and a gas pressure measuring device are assigned to each of the first accumulator 34 and the second accumulator 79. This makes it possible to monitor the amount of gas filled in the first accumulator 34 and the amount of gas filled in the second accumulator 79 separately.

[0090] For example, the gas pressure of the second accumulator 79 may be measured with the first accumulator 34 filled with control oil. In this case, the first test solenoid valve 72 connects the first accumulator 34 to the branch point P3. This maintains the trip function of the first accumulator 34. On the other hand, the second test solenoid valve 80 disconnects the second accumulator 79 from the branch point P3. In this case, the second accumulator 79 connects to the sixth drain line 83, and the control oil filled in the second accumulator 79 is discharged to the outlet 32 ​​through the sixth drain line 83. After that, the pressure of the gas filled in the second accumulator 79 can be measured by the second gas pressure measuring instrument 81.

[0091] The first accumulator 34 can also be filled with gas using a gas filling device 84, as shown in Figure 9.

[0092] Similarly, the trip function of the second accumulator 79 can be maintained while the pressure of the gas filled in the first accumulator 34 is being measured by the first gas pressure measuring instrument 73. The second accumulator 79 can also be filled with gas using a gas filling device 84, as shown in Figure 9.

[0093] Thus, according to this embodiment, it is possible to maintain the trip function of the other accumulator while monitoring the gas filling amount of one of the accumulators, the first accumulator 34 and the second accumulator 79. Therefore, the stability of the trip function of the steam valve drive device 10 can be improved.

[0094] (Seventh Embodiment) Next, the steam valve drive device in the seventh embodiment of the present invention will be described with reference to Figure 9.

[0095] In the seventh embodiment shown in Figure 9, the main difference is that the first accumulator is filled with gas from a gas filling device; the other configurations are substantially the same as those of the third embodiment shown in Figure 5. In Figure 9, the same reference numerals are used for parts identical to those in the third embodiment shown in Figure 5, and detailed descriptions are omitted.

[0096] As shown in Figure 9, the steam valve drive device 10 according to this embodiment includes a gas filling device 84. The gas filling device 84 is an example of a gas filling unit and is configured to fill the first accumulator 34 with gas. The gas filling device 84 may also include a gas filling line 85, a gas filling solenoid valve 86, and a gas cylinder 87. The gas filling line 85 connects the gas filling port (not shown) in the first accumulator 34 to the gas cylinder 87. The gas filling solenoid valve 86 is located in the gas filling line 85. The gas filling solenoid valve 86 is configured to allow or shut off the flow of gas in the gas filling line 85 in response to a command from a control device (not shown).

[0097] During gas filling, the gas pressure inside the first accumulator 34 is measured by the first gas pressure measuring instrument 73. Therefore, the gas can be filled into the first accumulator 34 according to the gas pressure inside the first accumulator 34.

[0098] As described above, according to this embodiment, the gas filling device 84 can fill the first accumulator 34 with gas. This allows the gas pressure in the first accumulator 34 to be adjusted to a pressure that maintains the trip function, thereby maintaining the trip function of the first accumulator 34. Therefore, it is possible to prevent the gas pressure in the first accumulator 34 from dropping and impairing the trip function of the first accumulator 34. As a result, the stability of the trip function can be improved. Furthermore, gas filling can be performed remotely using the gas filling solenoid valve 86 and the first gas pressure measuring instrument 73. Therefore, gas filling can be performed easily and quickly.

[0099] According to the embodiments described above, the stability of the trip function can be improved.

[0100] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Naturally, these embodiments can also be combined in part as appropriate within the scope of the spirit of the invention. [Explanation of Symbols]

[0101] 1: Steam valve, 10: Steam valve drive unit, 20: Cylinder, 22: Open chamber, 23: Closed chamber, 33: Servo valve, 34: First accumulator, 35: Closed-side dump valve, 36: Accumulator check valve, 37: Trip solenoid valve, 39: Open-side pilot check valve, 40: Open-side dump valve, 51: First line, 52: Second line, 53: Third line, 54: Fourth line, 55: Fifth line 56: Line 6, 70: Control Solenoid Valve, 71: Flow Limiter for Control Oil, 72: First Test Solenoid Valve, 73: First Gas Pressure Gauge, 75: Accumulator Piston, 76: Piston Position Gauge, 77: Bladder, 78: Bladder Strain Gauge, 79: Second Accumulator, 80: Second Test Solenoid Valve, 81: Second Gas Pressure Gauge, 82: Accumulator Line, 84: Gas Filling Device

Claims

1. A steam valve drive device that drives the steam valve to open and close, A cylinder including an open chamber to which hydraulic fluid is supplied when reset, and a closed chamber to which the hydraulic fluid is supplied when tripped, A control valve that allows or blocks the flow of the hydraulic fluid to the opening chamber and allows or blocks the discharge of the hydraulic fluid from the closing chamber, A first accumulator is connected to a second line branched from a first line that supplies the hydraulic fluid to the control valve, and fills the hydraulic fluid under pressure. A closed-side dump valve connected to a third line branched from the second line, which shuts off or allows the flow of the hydraulic fluid from the first accumulator to the closing chamber, In the second line, an accumulator check valve is positioned between the branching point of the second line from the first line and the branching point of the third line from the second line, Equipped with, The accumulator check valve blocks the flow of the hydraulic fluid from the first accumulator to the first line. Steam valve drive mechanism.

2. A trip solenoid valve is connected to a fourth line branched from the second line, which controls the closed-side dump valve, An open-side pilot check valve is located in a fifth line connecting the control valve and the opening chamber, and is controlled by the trip solenoid valve. An open-side dump valve connected to a sixth line that branches off from the portion of the fifth line between the open-side pilot check valve and the opening chamber, the open-side dump valve controlled by the trip solenoid valve, which shuts off or allows the discharge of the hydraulic fluid from the opening chamber, Equipped with, The open-side pilot check valve allows the flow of hydraulic fluid from the control valve to the open-direction chamber when reset, and blocks the flow of hydraulic fluid from the control valve to the open-direction chamber when tripped. The steam valve drive device according to claim 1.

3. The control valve is composed of a control solenoid valve. In the first line, a flow limiting unit capable of limiting the flow rate of the hydraulic fluid is positioned between the branching point of the second line and the control solenoid valve. The steam valve drive device according to claim 1 or 2.

4. In the second line, a first test solenoid valve is positioned between the branching point of the fourth line and the first accumulator, and controls the supply and discharge of the hydraulic fluid to and from the first accumulator. A first gas pressure measuring instrument for measuring the pressure of the gas filled in the first accumulator, A steam valve drive device according to claim 1 or 2, further comprising the above.

5. It is further equipped with a piston position measuring device, The first accumulator includes an accumulator piston that separates the hydraulic fluid and the gas. The piston position measuring device measures the position of the accumulator piston. The steam valve drive device according to claim 1 or 2.

6. Furthermore, equipped with a bladder distortion measuring instrument, The first accumulator includes a bladder that separates the hydraulic fluid and the gas. The bladder strain measuring device measures the strain of the bladder. The steam valve drive device according to claim 1.

7. A second accumulator is connected to an accumulator line branched from the second line and fills the hydraulic fluid under pressure, In the second line, a first test solenoid valve is positioned between the branching point of the accumulator line and the first accumulator, and controls the supply and discharge of the hydraulic fluid to and from the first accumulator. A first gas pressure measuring instrument for measuring the pressure of the gas filled in the first accumulator, A second test solenoid valve is positioned in the accumulator line and controls the supply and discharge of the hydraulic fluid to the second accumulator, A second gas pressure measuring instrument for measuring the pressure of the gas filled in the second accumulator, A steam valve drive device according to claim 1 or 2, further comprising the above.

8. A gas filling unit that fills the first accumulator with gas, It also has the following features: The steam valve drive device according to claim 4.

9. A steam valve drive device that drives the steam valve to open and close, A cylinder including an open chamber to which hydraulic fluid is supplied when reset, and a closed chamber to which the hydraulic fluid is supplied when tripped, A control valve that allows or blocks the flow of the hydraulic fluid to the opening chamber and allows or blocks the discharge of the hydraulic fluid from the closing chamber, A first accumulator is connected to a second line branched from a first line that supplies the hydraulic fluid to the control valve, and fills the hydraulic fluid under pressure. A closed-side dump valve connected to a third line branched from the second line, which shuts off or allows the flow of the hydraulic fluid from the first accumulator to the closing chamber, A trip solenoid valve is connected to a fourth line branched from the second line, which controls the closed-side dump valve, An open-side pilot check valve is located in a fifth line connecting the control valve and the opening chamber, and is controlled by the trip solenoid valve. An open-side dump valve connected to a sixth line that branches off from the portion of the fifth line between the open-side pilot check valve and the opening chamber, the open-side dump valve controlled by the trip solenoid valve, which shuts off or allows the discharge of the hydraulic fluid from the opening chamber, Equipped with, The open-side pilot check valve allows the flow of hydraulic fluid from the control valve to the open-direction chamber when reset, and blocks the flow of hydraulic fluid from the control valve to the open-direction chamber when tripped. Steam valve drive mechanism.

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