STEAM VALVE MEASURING METHOD AND STEAM VALVE MEASURING DEVICE

Abstract

A measuring method for a steam valve (14), comprising: a valve body (41) comprising a steam flow path (52) through which steam flows, and a valve seat (48) arranged in the center of the steam flow path (52) and having an opening portion; a stop valve (45) comprising a valve stem (61) extending in an axial direction where an axis extends and can be moved back and forth in the axial direction, a sub-valve (62) arranged at a distal end of the valve stem (61) in a distal end portion (61A) of the valve stem (61), and a main valve (64) comprising a through portion (71A) where a part of the distal end portion (61A) of the valve stem (61) that is closer to a proximal end side of the valve stem (61) than the distal end is inserted, closes the steam flow path (52) by being brought into contact with the valve seat (48), and is formed with a through hole (71B) where steam flows in when the sub-valve (62) is opened; and an actuator (46A, 46B) for driving the valve stem (61), wherein the measuring method for the steam valve (14) comprises: a step of measuring an acceleration of the valve stem (61) when the sub-valve (62) is opened by driving the valve stem (61) with the actuator (46A, 46B) from a fully closed state of the main valve (64) and the sub-valve (62); a step of detecting a time at which the sub-valve (62) is fully opened based on the measured acceleration of the valve stem (61); and a step of calculating a movement amount of the valve stem (61) from a reference position to a position where the sub-valve (62) is fully opened.

Description

TECHNICAL FIELD

[0001] The present invention relates to a measuring method for a steam valve and a measuring device for the steam valve. BACKGROUND

[0002] For example, in a power generation system using a steam turbine, a steam valve is used, which is configured to adjust the amount of steam supplied to drive a steam turbine according to a load change and to stop the steam supply to the steam turbine when an abnormality occurs. The steam valve typically includes a valve seat having an opening portion, a valve stem for moving a valve body disposed facing the opening portion of the valve seat in a direction toward and away from the valve seat, and a cylindrical support member for slidably supporting the valve stem (see, for example, Patent Document 1).

[0003] Patent Document 2 discloses a steam valve having a first inclined surface formed at the distal end portion of a valve rod, in which the outer diameter of the valve rod increases from the distal end to the base end of the valve rod, and a second inclined surface formed on the inner side of a portion of a main valve positioned on the base end side of the valve rod, which is inclined at the same inclination angle as the first inclined surface. In a state where a sub-valve and the main valve are closed, the first inclined surface and the second inclined surface are separated from each other, and when the sub-valve and the main valve are fully opened, the first inclined surface and the second inclined surface are in contact with each other.

[0004] Patent Document 3 discloses an apparatus and method for characterizing fluid valves. An example apparatus includes a fluid valve having a valve seat and a flow control element for sealing engagement with the valve seat. The apparatus includes a sensor for detecting a position change of the flow control element. The apparatus includes a processor for determining at least one of a touchdown point and a breakthrough point corresponding to the flow control element based on the position change. Citation listPatent literature Patent Document 1: JP 2014-70513 A Patent specification 2: US 2022 / 0082169 A1 Patent specification 3: US 2018 / 0335790 A1 SUMMARYTechnical problem

[0005] In the steam valve with such a configuration, wear is caused by rotation, chatter, etc. of the valve body due to steam. However, in the steam valve of the steam turbine, a wear occurrence section is often located in a high-temperature and high-pressure boiler, which makes it difficult to measure the wear progress while continuing operation of the steam turbine or without disassembling the steam valve.

[0006] In view of the foregoing, an object of at least one embodiment of the present invention is to provide a measuring method for a steam valve and a measuring device for the steam valve that are capable of checking the wear progress on the steam valve relatively easily. Solution to the problem

[0007] (1) A measuring method for a steam valve according to at least one embodiment of the present invention is a measuring method for a steam valve comprising: a valve body including a steam flow path through which steam flows, and a valve seat arranged in the center of the steam flow path and having an opening portion;a stop valve including a valve stem extending in an axial direction where an axis extends and can be moved back and forth in the axial direction, a sub-valve disposed at a distal end of the valve stem in a distal end portion of the valve stem, and a main valve including a through portion where a part of the distal end portion of the valve stem, which is located closer to a proximal end side of the valve stem than the distal end, is inserted, closes the steam flow path by being brought into contact with the valve seat, and is formed with a through hole where steam flows in when the sub-valve is opened;and an actuator for driving the valve stem, wherein the measuring method for the steam valve comprises: a step of measuring an acceleration of the valve stem when the sub-valve is opened by driving the valve stem with the actuator from a fully closed state of the main valve and the sub-valve; a step of detecting a time point at which the sub-valve is fully opened based on the measured acceleration of the valve stem; and a step of calculating a movement amount of the valve stem from a reference position to a position where the sub-valve is fully opened.

[0008] (2) A measuring device for a steam valve according to at least one embodiment of the present invention is a measuring device for a steam valve comprising: a valve body including a steam flow path through which steam flows and a valve seat arranged in the center of the steam flow path and having an opening portion;a stop valve including a valve stem extending in an axial direction where an axis extends and capable of being moved back and forth in the axial direction, a sub-valve disposed at a distal end of the valve stem in a distal end portion of the valve stem, and a main valve including a through portion where a part of the distal end portion of the valve stem, which is located closer to a proximal end side of the valve stem than the distal end, is inserted, closes the steam flow path by being brought into contact with the valve seat, and is formed with a through hole where steam flows in when the sub-valve is opened; and an actuator for driving the valve stem, wherein the measuring device for the steam valve comprises: an acceleration sensor for measuring an acceleration of the valve stem;a first detection unit for detecting a time at which the sub-valve is fully opened based on the acceleration of the valve stem measured by the acceleration sensor; and a calculation unit for calculating a movement amount of the valve stem from a reference position to a position where the sub-valve is fully opened. Beneficial effects

[0009] According to at least one embodiment of the present invention, it is possible to provide a measuring method for a steam valve and a measuring device for the steam valve that are capable of checking the wear progress on a steam valve relatively easily. SHORT DESCRIPTION OF DRAWINGS Fig. 1 is a schematic configuration diagram of a power generation system according to an embodiment. Fig. 2 is a cross-sectional view showing the configuration of a steam valve in a state where both a sub-valve and a main valve are closed according to an embodiment. Fig. Figure 3A is an enlarged view of an area A in Fig. 2. Fig. 3B is a schematic view showing a state in which the sub-valve is initially opened while the main valve is in the closed state in the Fig. steam valve shown in Figure 3A. Fig. 4 is a functional block diagram of a controller according to some embodiments. Fig. 5 is a flowchart showing a processing procedure in a measuring method for the steam valve according to the first embodiment. Fig. 6 is a graph showing a measurement result of a valve stem strain by a strain sensor and a measurement result of a valve stem acceleration by an acceleration sensor, wherein the horizontal axis represents the movement amount of a valve stem. Fig. 7 is a diagram showing an example of an estimated sub-valve lift transition. Fig. 8 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the second embodiment. Fig. 9 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the second embodiment. Fig. 10A is an enlarged view of an area B in Fig. 2. Fig. 10B is an enlarged view of the area B in Fig. 2. Fig. 11 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the third embodiment. Fig. 12 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the third embodiment. Fig. 13 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the fourth embodiment. Fig. 14 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the fourth embodiment. DETAILED DESCRIPTION

[0010] Embodiments of the present invention will be described below with reference to the accompanying drawings. However, dimensions, materials, shapes, relative positions, and the like of components described or shown in the drawings as the embodiments are intended to be interpreted as merely illustrative, and are not intended to limit the scope of the present invention unless specifically identified.

[0011] For example, an expression for a relative or absolute arrangement, such as "in one direction", "along one direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" should not be understood to indicate only the arrangement in a strict literal sense, but also to include a state in which the arrangement is relatively shifted by a tolerance or by an angle or a distance, whereby it is possible to achieve the same function.

[0012] For example, the expressions "the same", "equal" and "uniform" should not be understood to indicate only the state in which the characteristic is strictly the same, but also to include a state in which there is a tolerance or a difference that can still achieve the same function.

[0013] Furthermore, for example, an expression of a shape such as a rectangular shape or a tubular shape should not be understood to mean only the geometrically strict shape, but also to include a shape with bumps or bevelled corners within the range in which the same effect can be achieved.

[0014] On the other hand, the terms “comprising”, “including”, “with”, “containing” and “consisting of” for a constituent component are not exclusionary terms that exclude the presence of other constituent components. (Overall configuration of power generation system)

[0015] A power generation system 1 using a steam valve 14 to which a steam valve measuring method and a steam valve measuring device according to at least one embodiment of the present invention are applied will be described. Fig. 1 is a schematic configuration diagram of the power generation system 1 according to an embodiment. The power generation system 1 includes a steam turbine 10, a boiler 11, and a generator 26.

[0016] The steam turbine 10 is a turbine driven by steam generated in the boiler 11. The steam turbine 10 is connected to the boiler 11 via a first steam supply line 12 and is driven by being supplied with high-pressure steam generated by burning fuel in the boiler 11. The first steam supply line 12 is provided with the steam valve 14 for controlling the flow rate of steam supplied to the steam turbine 10. The steam valve 14 includes a control valve 43 and a stop valve 45, and the configuration of the steam valve 14 will be described in detail below.

[0017] In the present embodiment, a multi-stage turbine is exemplified as the steam turbine 10, and the steam turbine 10 includes a high-pressure steam turbine 31, an intermediate-pressure steam turbine 32, and a low-pressure steam turbine 33 from an upstream side with respect to a steam flow path. The high-pressure steam turbine 31 is driven by the steam supplied from the first steam supply line 12 (the high-pressure steam generated in the boiler 11). The steam that has completed work in the high-pressure steam turbine 31 is supplied to the intermediate-pressure steam turbine 32 via a second steam supply line 16. The second steam supply line 16 is provided with a reheater 18.

[0018] The intermediate-pressure steam turbine 32 is driven by the steam supplied from the second steam supply line 16 (the steam that has completed work in the high-pressure steam turbine 31). The steam that has completed work in the intermediate-pressure steam turbine 32 is supplied to the low-pressure steam turbine 33 via a third steam supply line 25. The low-pressure steam turbine 33 is driven by the steam supplied from the third steam supply line 25 (the steam that has completed work in the intermediate-pressure steam turbine 32).

[0019] The respective turbines (the high-pressure steam turbine 31, the intermediate-pressure steam turbine 32, and the low-pressure steam turbine 33) constituting the steam turbine 10 include a common rotating shaft 35. The rotating shaft 35 is coupled to the generator 26, and the generator 26 is driven by rotating the respective turbines, thereby generating power. (Configuration of steam valve 14 according to the first embodiment)

[0020] In the following, the configuration of the steam valve 14 according to an embodiment will be described with reference to Fig. 2 to 4B. Fig. 2 is a cross-sectional view showing the configuration of the steam valve 14 in a state where both a sub-valve 62 and a main valve 64 are closed according to an embodiment, Fig. Figure 3A is an enlarged view of an area A in Fig. 2, and Fig. 3B is a schematic view showing a state in which the sub-valve 62 is initially opened while the main valve 64 is in the closed state in the Fig. 3A shown steam valve 14.

[0021] In Fig. 2 to 3B, O1 is an axis of a valve stem 61 constituting the stop valve 45, and O2 is an axis of a valve stem 55 constituting the control valve 43. An extending direction of the axis O1, O2 (hereinafter referred to as an "axial direction Z") is, for example, a substantially vertical direction.

[0022] As in Fig. 2, the steam valve 14 according to one embodiment includes a valve body 41, the control valve 43, the stop valve 45, and actuators 46A, 46B. The valve body 41 includes a flow path dividing portion 47 and a valve seat 48. The flow path dividing portion 47 divides a steam flow path 52 and accommodates a part (distal end side) of the control valve 43 and a part (distal end side) of the stop valve 45. The steam flow path 52 has an inlet portion 52A and an outlet portion 52B. The inlet portion 52A is connected to the boiler 11 via one side of the first steam supply line 12, and the high-pressure steam generated in the boiler 11 is introduced. The outlet portion 52B is connected to the high-pressure steam turbine 31 via another side of the first steam supply line 12.The amount of steam supplied from the boiler 11 to the high-pressure steam turbine 31 via the first steam supply line 12 can be adjusted by controlling the opening degree of the control valve 43 in the state where the stop valve 45 in the steam valve 14 arranged in the first steam supply line 12 is opened.

[0023] In the steam valve 14 according to one embodiment, the actuator 46A, 46B is a hydraulic actuator that can be driven by pressurized oil.

[0024] The flow path dividing portion 47 includes a first guide member 47A and a second guide member 47B. The first guide member 47A is arranged to cover an outer peripheral surface of a portion of the valve stem 55 forming the control valve 43 that is not exposed to the steam flow path 52. The first guide member 47A functions as a guide for guiding the valve stem 55 in the axial direction Z. The second guide member 47B is arranged to cover an outer peripheral surface of a rod-shaped portion 61B forming the stop valve 45. The second guide member 47B functions as a guide for guiding the valve stem 61 in the axial direction Z.

[0025] The valve seat 48 is disposed in the flow path dividing portion 47 located at the center of the steam flow path 52. The valve seat 48 has an annular shape centered on the axis O1 and is configured such that the axis of the valve seat 48 coincides with the axis O1. The valve seat 48 has a valve seat surface 48a exposed to the steam flow path 52. The valve seat surface 48a is, for example, a curved surface. The main valve 64, which forms the stop valve 45, and a distal end 56A of a control valve body 56, which forms the control valve 43, can contact the valve seat surface 48a. (Control valve 43)

[0026] The control valve 43 is arranged upstream of a position where the stop valve 45 is arranged in a steam flow direction. The control valve 43 includes the valve stem 55 and the control valve body 56. The valve stem 55 extends in the axial direction Z, and a distal end side of the valve stem 55 is arranged in the steam flow path 52. The axis O1 of the valve stem 55 is configured to coincide with the axis O2 of the valve stem 55 of the stop valve 45. The valve stem 55 can be moved in the axial direction Z.

[0027] The control valve body 56 is arranged on the distal end side of the valve stem 55. A portion of the control valve body 56 arranged on the valve seat 48 side has a cylindrical shape and includes the distal end 56A that can contact the valve seat surface 48a of the valve seat 48. The control valve 43 with such a configuration controls an interval between the valve seat 48 and the distal end 56A of the control valve body 56 by moving the valve stem 55 along the axial direction Z with the actuator 46A, thereby having a function of controlling the flow rate of high-pressure steam supplied to the high-pressure steam turbine 31 according to a load of the steam turbine 10. (Stop valve 45)

[0028] The stop valve 45 is arranged on an inner side of the control valve 43. The stop valve 45 includes the valve stem 61, the sub-valve 62, and the main valve 64.

[0029] The valve stem 61 extends in the axial direction Z and has a distal end portion 61A and a rod-shaped portion 61B. The distal end portion 61A has a shape that can engage with the sub-valve 62 to fix the sub-valve 62. The rod-shaped portion 61B extends along the axial direction Z. The rod-shaped portion 61B has a proximal end portion connected to the actuator 46B via an actuator crosshead 49. Thus, the valve stem 61, which has the distal end portion 61A and the rod-shaped portion 61B, is integrally formed and is moved back and forth in the axial direction Z.

[0030] As in Fig. 3A, the sub-valve 62 has a contact portion 621. In the steam valve 14 according to an embodiment, the sub-valve 62 is fixed to the distal end portion 61A of the valve stem 61.

[0031] The contact portion 621 forms an outer peripheral portion of the sub-valve 62. The contact portion 621 extends obliquely downward and is formed in a ring shape when viewed from the axial direction Z. In a state in which the sub-valve 62 is closed (the state shown in Fig. 2 and Fig. 3A), the contact portion 621 is brought into contact with a valve seat surface 71a formed in a main valve body 71 constituting the main valve 64. In this state, since a state is entered in which an inlet 71Ba of a through hole 71B is separated from the steam flow path 52 through which high-pressure steam flows, no high-pressure steam flows through the through hole 71B.

[0032] In the steam valve 14, the stop valve 45 is opened before the control valve 43 is opened when the flow rate of steam is controlled by the control valve 43. At this time, in the stop valve 45, the sub-valve 62 is opened before the main valve 64 (the main valve 64 remains closed), as shown in Fig. 3B, from the state in which both the sub-valve 62 and the main valve 64, as shown in Fig. 2 and Fig. 3A are closed. At this time, since the contact portion 621 of the sub-valve 62 is separated from the valve seat surface 71a, thereby forming a gap between the sub-valve 62 and the main valve 64, high-pressure steam flows into the inlet 71Ba of the through-hole 71B. The high-pressure steam flowing into the inlet 71Ba of the through-hole 71B is led out from an outlet 71Bb of the through-hole 71B to the steam flow path 52. Consequently, a differential pressure between upstream and downstream sides of the main valve 64 is reduced, thereby facilitating a subsequent opening operation of the main valve 64.

[0033] The main valve 64 is disposed between the sub-valve 62 and the rod-shaped portion 61B while being inserted into the valve stem 61. The main valve 64 includes the main valve body 71. The main valve body 71 has a substantially V-shaped configuration in a vertical cross-sectional view. The main valve body 71 includes a through portion 71A, the valve seat surface 71a, a contact surface 71b, and the plurality of through holes 71B.

[0034] The through portion 71A is formed to pass through a central portion of the main valve body 71 in the axial direction Z. The through portion 71A is, for example, a columnar hole and is defined by an inner peripheral surface 71c. The distal end portion 61A of the valve stem 61 is inserted through the through portion 71A. A bushing (not shown) may be disposed in the through portion 71A.

[0035] The inner peripheral surface 71c is in contact with an outer peripheral surface of the valve stem 61 in a state where the distal end portion 61A of the valve stem 61 can be moved in the axial direction Z.

[0036] The valve stem 61 has an inclined valve stem surface 619 that extends an outer diameter of the valve stem 61 from the distal end side to a proximal end side of the valve stem 61 in a region where the outer peripheral surface is covered with the inner peripheral surface 71c of the main valve body 71. The inclined valve stem surface 619 is a conically inclined surface.

[0037] The main valve body 71 has a contact surface 711 which contacts the inclined valve stem surface 619 of the valve stem 61, as shown in Fig. 3B. The contact surface 711 is a conical surface formed to expand an inner diameter of the contact surface 711 from the distal end side to the proximal end side.

[0038] The valve seat surface 71a is a curved surface located on the side of the sub-valve 62 (the distal end side of the valve stem 61). The contact portion 621 of the sub-valve 62 is brought into contact with a surface of the valve seat surface 71a located on a radially outer side centered on the axis O1 of the valve stem 60 relative to the inlets 71Ba of the plurality of through holes 71B when the sub-valve 62 is closed (see FIG. Fig. 2 and Fig. 3A).

[0039] The contact surface 71b is a curved surface located on the proximal end side of the valve stem 61. An outer peripheral portion of the contact surface 71b is brought into contact with the valve seat surface 48a of the valve seat 48 in a state where the main valve 64 is fully closed. In this state, no high-pressure steam flows downstream of the valve seat 48. On the other hand, since the contact surface 71b and the valve seat surface 48a are separated from each other and a gap is formed between the contact surface 71b and the valve seat surface 48a, high-pressure steam corresponding to the opening degree of the control valve 43 flows downstream of the valve seat 48.

[0040] The plurality of through holes 71B are formed to pass through the main valve body 71 so as to reach the contact surface 71b from the valve seat surface 71a. The plurality of through holes 71B are arranged in the circumferential direction of the main valve body 71. Each of the through holes 71B has the inlet 71Ba and the outlet 71Bb. The inlet 71Ba is formed in the valve seat surface 71a, which is located on a radially inner side centered on the axis O1 of the valve stem 60 relative to the contact position between the contact portion 62B and the valve seat surface 71a. If the sub-valve 62 is located in front of the main valve 64, as shown in Fig. 3B, and a gap is formed between the sub-valve 62 and the main valve 64, a high-pressure steam flows into the through-hole 71B via the inlet 71Ba.

[0041] The outlet 71Bb is formed in the contact surface 71b located radially outside the axis O1 relative to the formation position of the inlet 71Ba. The outlet 71Bb communicates with the steam flow path 52 located downstream of the valve seat 48. The through hole 71B of the present embodiment is inclined in the direction from the inlet 71Ba to the outlet 71Bb. (Regarding operation of stop valve 45 of steam valve 14)

[0042] In the steam valve 14 according to an embodiment, the stop valve 45 is operated as follows.

[0043] In the steam valve 14, the stop valve 45 is opened before the control valve 43 is opened when the flow rate of steam is controlled by the control valve 43. (When fully closed)

[0044] If the stop valve 45, as in Fig. 2 and Fig. 3A, is fully closed, the valve stem 61 is biased toward the proximal end side by a biasing force from a closing spring (not shown). Therefore, the contact portion 621 of the sub-valve 62 fixed to the valve stem 61 presses the valve seat surface 71a toward the proximal end side. Consequently, the main valve 64 is in a state of being interposed between the contact portion 621 of the sub-valve 62 and the valve seat surface 48a of the valve seat 48. Thus, when the stop valve 45 is fully closed, the main valve 64 and the sub-valve 62 are in the closed state.

[0045] Since, in the state where the sub-valve is closed, the state is entered where the inlet 71Ba of the through-hole 71B is separated from the steam flow path 52 through which a high-pressure steam flows as described above, no high-pressure steam flows through the through-hole 71B.

[0046] If the stop valve 45, as in Fig. 3A, is fully closed, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 are separated from each other in the axial direction Z. (Case where stop valve 45 starts to open from fully closed state)

[0047] In the state where the valve stem 61 starts to move to the distal end side by the actuator 46B from the fully closed state of the Fig. 2 and Fig. 3A, the valve seat surface 71a of the main valve body 71 and the contact portion 621 of the sub-valve 62 are driven as shown in Fig. 3B, separated from each other, while the main valve 64 remains closed. Consequently, high-pressure steam flows into the inlet 71Ba of the through-hole 71B from the gap between the valve seat surface 71a and the contact portion 621. As described above, the high-pressure steam flowing into the inlet 71Ba of the through-hole 71B is led out from the outlet 71Bb of the through-hole 71B to the steam flow path 52. Consequently, a differential pressure between upstream and downstream sides of the main valve 64 is reduced, thereby facilitating a subsequent opening operation of the main valve 64. (From the beginning of an opening to a fully open state of stop valve 45)

[0048] If the valve stem 61 is further driven to the distal end side by the actuator 46B from the state where the stop valve 45 starts to open as described above, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 contact each other as shown in Fig. 3B. Consequently, if the valve stem 61 is further driven toward the distal end side by the actuator 46B, the main valve body 71 moves toward the distal end side and is separated from the valve seat surface 48a of the valve seat 48.

[0049] If the second valve stem 162 is further driven to the distal end side by the actuator 46B, the stop valve 45 enters a fully open state. (During closing operation)

[0050] When the stop valve 45 is closed, if the valve stem 61 is driven to the proximal end side by the actuator 46B, the main valve 64 and the sub-valve 62 move to the proximal end side together with the valve stem 61.

[0051] Then, the main valve body 71 contacts the valve seat surface 48a of the valve seat 48, thereby closing the main valve 64.

[0052] By driving the valve stem 61 toward the proximal end side with the actuator 46B, even after the main valve 64 has been closed, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 are separated from each other. Then, the valve seat surface 71a of the main valve body 71 and the contact portion 621 of the sub-valve 62 contact each other, as shown in Fig. 3A, whereby the secondary valve 62 is closed.

[0053] The steam valve 14, to which the steam valve measurement method according to some embodiments described below is applied, includes the valve body 41, the stop valve 45, and the actuator 46B for driving the valve stem 61, as described above. The valve body 41 includes the steam flow path 52 through which steam flows, and the valve seat 48 located in the center of the steam flow path 52 and having the opening portion.The stop valve 45 includes: the valve stem 61 extending in the axial direction Z in which the axis O1, O2 extends and can be moved back and forth in the axial direction Z; the sub-valve 62 disposed at the distal end of the valve stem 61 in the distal end portion 61A of the valve stem 61; and the main valve 64 including the through portion 71A in which a part of the distal end portion 61A of the valve stem 61, which is located closer to the proximal end side of the valve stem 61 than the distal end, is inserted, closes the steam flow path 52 by being brought into contact with the valve seat 48, and is formed with the through hole 71B into which steam flows when the sub-valve 62 is opened. (Regarding wear on steam valve 14)

[0054] In the steam valve 14 of one embodiment, for example, in the stop valve 45, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 repeatedly contact and separate from each other each time the stop valve 45 is opened and closed. Consequently, wear between the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 progresses as the frequency of opening and closing the stop valve 45 increases.

[0055] However, since, for example, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 are housed in the valve casing (valve body 41) which is the high-pressure boiler, it is conventionally impossible to detect the progress of wear unless the steam turbine 10 is stopped and the steam valve 14 is disassembled.

[0056] Here, for example, if the above-described wear between the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 progresses, a distance in the axial direction Z between the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 increases when the stop valve 45 is fully closed. Consequently, if the wear between the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 progresses, the movement amount of the valve stem 61 increases from the time when the stop valve 45 is fully closed, as shown in Fig. 3A, at a time when the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 contact each other, and the sub-valve 62, as shown in Fig. 3B, is fully open.

[0057] Therefore, in the measuring method for the steam valve according to some embodiments, the wear on the steam valve 14 is detected by calculating the amount of movement of the valve stem 61 from a reference position of the valve stem 61 to a position where the sub-valve 62 is fully opened as follows. (First embodiment)

[0058] Fig. 2 shows an apparatus configuration for implementing the measuring method for the steam valve according to the first embodiment.

[0059] That is, a measuring device 100 for the steam valve according to the first embodiment includes an acceleration sensor 101, a strain sensor 103, a displacement measuring device 105, and a controller 110.

[0060] The acceleration sensor 101 is an acceleration sensor for measuring an acceleration of the valve stem 61. The acceleration sensor 101 is attached, for example, to a proximal end portion 61C of the valve stem 61, which protrudes outward from the valve housing (valve body 41).

[0061] The strain sensor 103 is, for example, a strain gauge for measuring the strain on the valve stem 61. The strain sensor 103 is, for example, attached to the proximal end portion 61C of the valve stem 61.

[0062] The displacement gauge 105 is a displacement sensor for measuring the movement amount (displacement) of the valve stem 61. The displacement gauge 105 is arranged outside the valve housing (valve body 41) and configured to measure, for example, a distance to a displacement gauge target 105a attached to the proximal end portion 61C of the valve stem 61.

[0063] The controller 110 includes a processor 111 for performing various types of arithmetic processing, and a memory 113 for non-temporarily or temporarily storing various data processed by the processor 111. The processor 111 is implemented by a CPU, GPU, MPU, DSP, various types of other computing devices, a combination of these, or the like. The memory 113 is implemented by a ROM, a RAM, a flash memory, a combination of these, or the like.

[0064] Fig. 4 is a functional block diagram of the controller 110 according to some embodiments.

[0065] The controller 110 according to some embodiments includes a first detection unit 121, a second detection unit 122, a calculation unit 123, and an evaluation unit 124 as functional blocks. These functional blocks are implemented by the processor 111, which executes the programs stored in the memory 113.

[0066] Fig. 5 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the first embodiment. Fig. The process shown in Figure 5 is implemented by the processor 111, which executes the programs stored in the memory 113.

[0067] In the measuring method for the steam valve according to the first embodiment, the reference position of the valve stem 61 is a position of the valve stem 61 at the start of opening of the sub-valve 62 when the contact portion 621 of the sub-valve 62 and the valve seat surface 48a of the valve seat 48 start to separate when the sub-valve 62 is opened.

[0068] In the measuring method for the steam valve according to the first embodiment, a timing at which the sub-valve 62 starts to open is detected from a measurement result of the strain on the valve stem 61.

[0069] In the measuring method for the steam valve according to the first embodiment, a time point at which the sub-valve 62 is fully opened is detected from a measurement result of the acceleration of the valve stem 61.

[0070] In the measuring method for the steam valve according to the first embodiment, the movement amount of the valve stem 61 is measured by the displacement measuring device 105.

[0071] The controller 110 starts measuring the valve stem strain by the strain sensor 103 (step S1) and starts measuring the valve stem acceleration by the acceleration sensor 101 (step S2).

[0072] In addition, the controller 110 starts measuring the distance to the displacement measuring device target 105a, that is, the movement amount of the valve stem 61 by the displacement measuring device 105 (step S3).

[0073] Fig. 6 is a graph showing the measurement result of valve stem strain by the strain sensor 103 and the measurement result of valve stem acceleration by the acceleration sensor 101, wherein the horizontal axis represents the movement amount of the valve stem 61.

[0074] The second detection unit 122 of the controller 110 detects the timing at which the sub-valve 62 starts to open based on the measurement result of the valve stem extension by the displacement measuring device 105 (step S4).

[0075] Immediately before the sub-valve 62 starts to open, the sub-valve 62 is to be opened against the pressure of the high-pressure steam acting on the sub-valve 62, and thus a relatively large pressure force acts on the valve stem 61. Consequently, a relatively large pressure strain is generated on the valve stem 61.

[0076] When the sub-valve 62 begins to open, the high-pressure steam flows into the inlet 71Ba of the through-hole 71B from the gap between the valve seat surface 71a and the contact portion 621 and is discharged from the outlet 71Bb of the through-hole 71B to the steam flow path 52 as described above, thereby reducing the pressure of the steam acting on the sub-valve 62. Consequently, the pressure strain on the valve stem 61 gradually decreases.

[0077] Therefore, on a diagram line g1, which represents the expansion on the valve stem 61 in Fig. 6, a point S1, where the pressure strain on the valve stem 61 suddenly begins to decrease, represents the beginning of opening of the sub-valve 62.

[0078] The first detection unit 121 of the controller 110 detects the time at which the sub-valve 62 is fully opened based on the measurement result of the valve stem acceleration by the acceleration sensor 101 (step S5).

[0079] At the time when the sub-valve 62 is fully opened as described above, the inclined valve stem surface 619 of the valve stem 61 and the contact surface 711 of the main valve body 71 contact each other as shown in Fig. 3B. Therefore, a relatively clear peak value P1 appears on a graph line g2, which represents the acceleration of the valve stem 61 in Fig. 6. A point where this peak value P1 occurs is a point where the sub-valve 62 is fully open.

[0080] The calculation unit 123 of the controller 110 calculates a difference between a lift amount (position) of the valve stem 61 corresponding to the point S1 on the graph line g1 representing the strain on the valve stem 61 in Fig. 6, and a lift size (position) of the valve stem 61 corresponding to the peak value P1 on the diagram line g2 representing the acceleration of the valve stem 61 in Fig. 6, as the amount of movement of the valve stem (sub-valve lift) from the reference position (the position where the sub-valve 62 starts to open) to the position where the sub-valve 62 is fully opened.

[0081] Fig. 7 is an example showing how the sub-valve lift (estimated sub-valve lift) calculated as described above changes each time the steam turbine 10 is started. As in Fig. 7, the estimated bypass valve lift increases gradually each time the steam turbine 10 is started.

[0082] The evaluation unit 124 of the controller 110 evaluates the amount of wear on the steam valve 14 from the estimated sub-valve lift. Specifically, for example, the evaluation unit 124 may determine whether the estimated sub-valve lift exceeds a predetermined threshold, and if it is determined that the estimated sub-valve lift exceeds the threshold, a notification signal is output to notify the outside that the estimated sub-valve lift exceeds the threshold. (Second embodiment)

[0083] Fig. 8 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the second embodiment.

[0084] The steam valve measuring device 100 according to the second embodiment includes the acceleration sensor 101, the displacement measuring device 105, and the controller 110.

[0085] In the following description, the same components as those of the measuring device 100 for the steam valve according to the first embodiment are given the same reference numerals as those of the measuring device 100 for the steam valve according to the first embodiment, and a detailed description thereof will be omitted.

[0086] In the measuring method for the steam valve according to the second embodiment, the reference position of the valve stem 61 is the position of the valve stem 61 at the beginning of opening of the sub-valve 62, at which the contact portion 621 of the sub-valve 62 and the valve seat surface 48a of the valve seat 48 start to separate when the sub-valve 62 is opened.

[0087] In the measuring method for the steam valve according to the second embodiment, the timing at which the sub-valve 62 starts to open is detected not from the measurement result of the strain on the valve stem 61, but from the measurement result of the acceleration of the valve stem 61.

[0088] In the measuring method for the steam valve according to the second embodiment, the time at which the sub-valve 62 is fully opened is detected from the measurement result of the acceleration of the valve stem 61 as in the first embodiment.

[0089] In the measuring method for the steam valve according to the first embodiment, the movement amount of the valve stem 61 is measured by the displacement measuring device 105 as in the first embodiment.

[0090] Fig. 9 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the second embodiment. Fig. The process shown in Figure 9 is implemented by the processor 111, which executes the programs stored in the memory 113.

[0091] The controller 110 starts measuring a valve stem acceleration by the acceleration sensor 101 (step S2).

[0092] In addition, the controller 110 starts measuring the distance to the displacement measuring device target 105a, that is, the movement amount of the valve stem 61 by the displacement measuring device 105 (step S3).

[0093] The second detection unit 122 of the controller 110 detects the timing at which the sub-valve 62 starts to open based on the measurement result of the valve stem acceleration by the acceleration sensor 101 (step S4).

[0094] Fig. 10A is an enlarged view of an area B in Fig. 2, and is a view showing the vicinity of the actuator crosshead 49 and the proximal end portion 61C of the valve stem 61 when the stop valve 45 is fully closed.

[0095] Fig. 10B is an enlarged view of the area B in Fig. 2, and is a view showing the vicinity of the actuator crosshead 49 and the proximal end portion 61C of the valve stem 61 immediately after the actuator 46B has started to be driven from a time point when the stop valve 45 is fully closed.

[0096] As in Fig. 10A and Fig. 10B, there is a slight gap in the axial direction Z in a fitting portion between the proximal end portion 61C of the valve stem 61 and the actuator crosshead 49. Therefore, if the actuator 46B starts to be driven from a time when the stop valve 45 is fully closed, a distal end side surface 49a of the actuator crosshead 49 collides with the proximal end portion 61C of the valve stem 61. At this time, the valve stem 61 experiences an impact due to the collision. Consequently, a peak value P2 appears on the graph line g2, which represents the acceleration of the valve stem 61 in Fig. 6. The point at which this peak value P2 appears is the beginning of an opening of the secondary valve 62.

[0097] The first detection unit 121 of the controller 110 detects the time at which the sub-valve 62 is fully opened based on the measurement result of the valve stem acceleration by the acceleration sensor 101 (step S5).

[0098] The calculation unit 123 of the controller 110 calculates a difference between a lift amount (position) of the valve stem 61 corresponding to the peak value P2 on the graph line g2 and the lift amount (position) of the valve stem 61 corresponding to the peak value P1 on the graph line g2 as the movement amount of the valve stem (sub-valve lift) from the reference position (the position where the sub-valve 62 starts to open) to the position where the sub-valve 62 is fully opened.

[0099] The evaluation unit 124 of the controller 110 evaluates the amount of wear on the steam valve 14 from the estimated sub-valve lift as described above (step S6). (Third embodiment)

[0100] Fig. 11 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the third embodiment.

[0101] The steam valve measuring device 100 according to the third embodiment includes the acceleration sensor 101, the strain sensor 103, and the controller 110.

[0102] In the following description, the same components as those of the measuring device 100 for the steam valve according to the first embodiment are given the same reference numerals as those of the measuring device 100 for the steam valve according to the first embodiment, and a detailed description thereof will be omitted.

[0103] In the measuring method for the steam valve according to the third embodiment, the reference position of the valve stem 61 is the position of the valve stem 61 at the start of opening of the sub-valve 62, at which the contact portion 621 of the sub-valve 62 and the valve seat surface 48a of the valve seat 48 start to separate when the sub-valve 62 is opened.

[0104] In the measuring method for the steam valve according to the third embodiment, the timing at which the sub-valve 62 starts to open is detected from the measurement result of the strain on the valve stem 61 as in the first embodiment.

[0105] In the measuring method for the steam valve according to the third embodiment, the time at which the sub-valve 62 is fully opened is detected from the measurement result of the acceleration of the valve stem 61 as in the first embodiment.

[0106] In the measuring method for the steam valve according to the third embodiment, the movement amount of the valve stem 61 is not measured by the displacement measuring device 105, but the movement amount of the valve stem 61 is calculated from previously acquired valve opening speed information (a movement speed of the valve stem 61) and an elapsed time. That is, in the measuring method for the steam valve according to the third embodiment, for example, the movement amount of the valve stem 61 is calculated based on the previously acquired valve opening speed information, such as the movement speed of the valve stem 61 obtained in advance by actual measurement, the movement speed of the valve stem 61 obtained in advance based on the drive speed of the actuator 46B estimated from the specifications of the actuator 46B, and the amount of pressurized oil supplied to the actuator 46B, or the like.

[0107] Fig. 12 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the third embodiment. Fig. The process shown in Figure 12 is implemented by the processor 111, which executes the programs stored in the memory 113.

[0108] The controller 110 starts measuring a valve stem strain by the strain sensor 103 (step S1) and starts measuring a valve strain acceleration by the acceleration sensor 101 (step S2).

[0109] In addition, the controller 110 reads the valve opening speed information stored in the memory 113 and measures, for example, the elapsed time from the start of driving by the actuator 46B (step S7).

[0110] The second detection unit 122 of the controller 110 detects the timing at which the sub-valve 62 starts to open based on the measurement result of the valve stem extension by the displacement measuring device 105 (step S4).

[0111] The first detection unit 121 of the controller 110 detects the time at which the sub-valve 62 is fully opened based on the measurement result of the valve stem acceleration by the acceleration sensor 101 (step S5).

[0112] The calculation unit 123 of the controller 110 calculates the lift amount (position) of the valve stem 61 corresponding to the point S1 on the diagram line g1 representing the strain on the valve stem 61 in Fig. 6, from the valve opening speed information acquired in advance and the elapsed time from the start of driving by the actuator 46B to the detection of the point S1 on the graph line g1.

[0113] The calculation unit 123 of the controller 110 calculates the lift amount (position) of the valve stem 61 corresponding to the peak value P1 on the graph line g2 representing the acceleration of the valve stem 61 in Fig. 6, from the valve opening speed information acquired in advance and the elapsed time from the start of driving by the actuator 46B to the detection of the peak value P1 on the graph line g2.

[0114] Then, the calculation unit 123 of the controller 110 calculates the difference between the lift amount (position) of the valve stem 61 corresponding to the point S1 on the graph line g1 and the lift amount (position) of the valve stem 61 corresponding to the peak value P1 on the graph line g2 as the movement amount of the valve stem (sub-valve lift) from the reference position (the position where the sub-valve 62 starts to open) to the position where the sub-valve 62 is fully opened.

[0115] The evaluation unit 124 of the controller 110 evaluates the wear amount on the steam valve 14 from the estimated sub-valve lift as described above (step S6). (Fourth embodiment)

[0116] Fig. 13 is a diagram showing an apparatus configuration for implementing the measuring method for the steam valve according to the fourth embodiment.

[0117] The measuring device 100 for the steam valve according to the first embodiment includes the acceleration sensor 101, the strain sensor 103, a pressure sensor 107 and the controller 110.

[0118] The pressure sensor 107 is a pressure sensor for measuring the pressure of pressurized oil supplied to the actuator 46B (actuator oil pressure).

[0119] In the following description, the same components as those of the measuring device 100 for the steam valve according to the first embodiment are given the same reference numerals as those of the measuring device 100 for the steam valve according to the first embodiment, and a detailed description thereof will be omitted.

[0120] In the measuring method for the steam valve according to the fourth embodiment, the reference position of the valve stem 61 is the position of the valve stem 61 at the start of opening of the sub-valve 62, wherein the contact portion 621 of the sub-valve 62 and the valve seat surface 48a of the valve seat 48 start to separate when the sub-valve 62 is opened.

[0121] In the measuring method for the steam valve according to the first embodiment, the timing at which the sub-valve 62 starts to open is detected not from the measurement result of the strain on the valve stem 61, but from the pressure of pressurized oil supplied to the actuator 46B (actuator oil pressure).

[0122] In the measuring method for the steam valve according to the first embodiment, the timing at which the sub-valve 62 is fully opened is detected from the measurement result of the acceleration of the valve stem 61.

[0123] In the measuring method for the steam valve according to the first embodiment, the movement amount of the valve stem 61 is measured by the displacement measuring device 105.

[0124] Fig. Fig. 14 is a flowchart showing a processing procedure in the measuring method for the steam valve according to the fourth embodiment. Fig. The process shown in Figure 14 is implemented by the processor 111, which executes the programs stored in the memory 113.

[0125] The controller 110 starts measuring the actuator oil pressure by the pressure sensor 107 (step S8) and starts measuring the valve stem acceleration by the acceleration sensor 101 (step S2).

[0126] In addition, the controller 110 starts measuring the distance to the displacement measuring device target 105a, that is, the movement amount of the valve stem 61 by the displacement measuring device 105 (step S3).

[0127] The second detection unit 122 of the controller 110 detects the timing at which the sub-valve 62 starts to open based on the measurement result of the actuator oil pressure by the pressure sensor 107 (step S4).

[0128] Immediately before the secondary valve 62 begins to open, the secondary valve 62 should be opened against the pressure of the high-pressure steam acting on the secondary valve 62, and thus the actuator oil pressure increases.

[0129] When the sub-valve 62 starts to open, the high-pressure steam flows into the inlet 71Ba of the through-hole 71B from the gap between the valve seat surface 71a and the contact portion 621 and is led out of the outlet 71Bb of the through-hole 71B to the steam flow path 52 as described above, thereby reducing the pressure of the steam acting on the sub-valve 62. Consequently, the actuator oil pressure gradually decreases. That is, the actuator oil pressure shows a pressure change similar to the graph line g1 representing the strain on the valve stem 61 in Fig. 6 represents.

[0130] Therefore, the point at which the actuator oil pressure suddenly begins to decrease is the beginning of an opening of the sub-valve 62, as the point S1 on the diagram line g1 representing the expansion on the valve stem 61 in Fig. 6, using the measurement result of the actuator oil pressure.

[0131] The first detection unit 121 of the controller 110 detects the time at which the sub-valve 62 is fully opened based on the measurement result of the valve stem acceleration by the acceleration sensor 101 (step S5).

[0132] The calculation unit 123 of the controller 110 calculates a difference between the lift amount (position) of the valve stem 61 corresponding to the above-described point at which the actuator oil pressure suddenly starts to decrease and the lift amount (position) of the valve stem 61 corresponding to the peak value P1 on the graph line g2 representing the acceleration of the valve stem 61 in Fig. 6, as the amount of movement of the valve stem (sub-valve lift) from the reference position (the position where the sub-valve 62 starts to open) to the position where the sub-valve 62 is fully opened.

[0133] The evaluation unit 124 of the controller 110 evaluates the amount of wear on the steam valve 14 from the estimated sub-valve lift as described above (step S6).

[0134] As described above, the measuring method for the steam valve according to some embodiments includes: step S2 of measuring the acceleration of the valve stem 61 when the sub-valve 62 is opened by driving the valve stem 61 with the actuator 46B from the fully closed state of the main valve 64 and the sub-valve 62; step S5 of detecting the time point at which the sub-valve 62 is fully opened based on the measured acceleration of the valve stem 61; and step S6 of calculating the movement amount of the valve stem from the reference position to the position where the sub-valve 62 is fully opened.

[0135] In the measuring method for the steam valve according to some embodiments, by detecting the acceleration of the valve stem 61, it is possible to detect the time at which the sub-valve 62 is fully opened without disassembling the steam valve 14 while continuing the operation of the steam turbine 10. Furthermore, in the measuring method for the steam valve according to some embodiments, the time at which the sub-valve 62 is fully opened can be accurately detected by detecting the acceleration of the valve stem 61. This improves the accuracy of calculating the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, and improves the accuracy of measuring the wear on the valve stem 61.

[0136] The steam valve measuring device 100 according to some embodiments includes: the acceleration sensor 101 for measuring the acceleration of the valve stem 61; the first detection unit 121 for detecting the time at which the sub-valve 62 is fully opened based on the acceleration of the valve stem 61 measured by the acceleration sensor 101; and the calculation unit 123 for calculating the movement amount of the valve stem 61 from the reference position to the position at which the sub-valve 62 is fully opened.

[0137] In the steam valve measuring device 100 according to some embodiments, by measuring the acceleration of the valve stem 61, it is possible to detect the time at which the sub-valve 62 is fully opened without disassembling the steam valve 14 while continuing the operation of the steam turbine 10. Furthermore, in the steam valve measuring device 100 according to some embodiments, the time at which the sub-valve 62 is fully opened can be accurately detected by measuring the acceleration of the valve stem 61. This improves the accuracy of calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, and improves the accuracy of measuring the wear on the steam valve 14.

[0138] In the measuring method for the steam valve according to some embodiments, the above-described reference position is the position of the valve stem 61 when the sub-valve 62 starts to open.

[0139] Similarly, the steam valve measuring device 100 according to some embodiments includes the second detection unit 122 for detecting the timing at which the sub-valve 62 starts to open. The calculation unit 123 calculates the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened at the timing when the sub-valve 62 starts to open, which is detected by the second detection unit 122, as the reference position.

[0140] By setting the reference position to the position of the valve stem 61 when the sub-valve 62 starts to open, it is possible to relatively accurately specify the reference position to be referred to when calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, thereby improving the accuracy of the amount of movement of the valve stem 61 from the calculated reference position to the position where the sub-valve 62 is fully opened.

[0141] The measuring method for the steam valve according to some in Fig. 5 and Fig. 12 includes: step S1 of measuring the strain on the valve stem 61 when the sub-valve 62 is opened by driving the valve stem 61 with the actuator 46B from the fully closed state of the main valve 64 and the sub-valve 62; and step S4 of detecting the timing at which the sub-valve 62 starts to open based on the measured strain on the valve stem 61.

[0142] Since a relatively large force is required to open the sub-valve 62, the strain on the valve stem 61 when the sub-valve 62 is open can be measured relatively easily. Therefore, the timing at which the sub-valve 62 starts to open is easily detected. Furthermore, the accuracy of detecting the timing at which the sub-valve 62 starts to open can be improved by measuring the strain on the valve stem 61 when the sub-valve 62 is open.

[0143] The Fig. The steam valve measuring method shown in Fig. 9 includes step S4 for detecting the time at which the sub-valve 62 starts to open based on the measured acceleration of the valve stem 61.

[0144] Since it is in the Fig. 9, for example, it is possible to detect the time at which the sub-valve 62 starts to open and the time at which the sub-valve 62 is fully opened based on the measurement result of the same acceleration sensor 101, it is possible to simplify the device configuration for detecting these times. In the method shown in Fig. 9, it is possible to omit the difficulty in measuring the strain on the valve stem 61 compared with a case where the timing at which the sub-valve 62 starts to open is detected based on the strain, for example.

[0145] The Fig. The measuring method for the steam valve shown in Fig. 14 includes: step S8 of measuring the pressure of the pressurized oil supplied to the actuator 46B when the sub-valve 62 is opened by driving the valve stem with the actuator 46B from the fully closed state of the main valve 64 and the sub-valve 62; and step S4 of detecting the timing at which the sub-valve 62 starts to open based on the measured pressure of the pressurized oil.

[0146] Since in the Fig. 14, the pressure of the pressure oil supplied to the actuator 46B serving as the hydraulic actuator is measured relatively easily, it is possible to relatively easily detect the time at which the sub-valve 62 begins to open. In addition, in the Fig. 14, it is possible to omit the difficulties for measuring the strain on the valve stem 61 compared with the case where the timing at which the sub-valve 62 starts to open is detected based on the strain, for example.

[0147] In the measuring method for the steam valve according to some embodiments, the above-described reference position does not have to be the position of the valve stem 61 when the sub-valve 62 starts to open, but may be, for example, a position of the valve stem 61 when the main valve 64 and the sub-valve 62 are in the fully closed state.

[0148] This makes it easy to set and record the reference position.

[0149] In the measuring method for the steam valve according to some in Fig. 5, Fig. 9 and Fig. 14, step S6 for calculating the movement amount of the valve stem 61 includes calculating the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened based on a change in a position of the valve stem 61 detected by the displacement measuring device 105.

[0150] Thereby, the accuracy for detecting the position of the valve stem 61 relatively increases, making it possible to improve the accuracy for calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened.

[0151] In the Fig. 12, step S6 for calculating the movement amount of the valve stem 61 includes calculating the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened based on the known movement speed information (valve opening speed information) of the valve stem 61.

[0152] Thus, it is possible to omit the displacement measuring device 105 for detecting the position of the valve stem 61.

[0153] The present invention is not limited to the above-described embodiments, and also includes an embodiment obtained by modifying the above-described embodiments or an embodiment obtained by combining these embodiments as needed.

[0154] For example, in the measuring method for the steam valve according to some embodiments described above, the Fig. 5, Fig. 9, Fig. 12 and Fig. 14 are performed by the processor 111, which executes the programs stored in the memory 113. However, in the steam valve measuring method according to some embodiments, at least some of the steps shown in Fig. 5, Fig. 9, Fig. 12 and Fig. 14 shown respective steps are carried out by a worker.

[0155] The contents described in the above embodiments would be understood, for example, as follows.

[0156] (1) A measuring method for a steam valve according to at least one embodiment of the present invention is a measuring method for a steam valve 14 comprising: a valve body 41 including a steam flow path 52 through which steam flows, and a valve seat 48 disposed in the center of the steam flow path 52 and having an opening portion;a stop valve 45 including a valve stem 61 extending in an axial direction Z where an axis O1, O2 extends and can be moved back and forth in the axial direction Z, a sub-valve 62 disposed at a distal end of the valve stem 61 in a distal end portion 61A of the valve stem 61, and a main valve 64 including a through portion 71A where a part of the distal end portion 61A of the valve stem 61, which is located closer to a proximal end side of the valve stem 61 than the distal end, is inserted, closes the steam flow path 52 by being brought into contact with the valve seat 48, and is formed with a through hole 71B where steam flows in when the sub-valve 62 is opened;and an actuator 46B for driving the valve stem 61. The measuring method for the steam valve according to at least one embodiment of the present invention includes: a step S2 for measuring an acceleration of the valve stem 61 when the sub-valve 62 is opened by driving the valve stem 61 with the actuator 46B from a fully closed state of the main valve 64 and the sub-valve 62; a step S5 for detecting a time point at which the sub-valve 62 is fully opened based on the measured acceleration of the valve stem 61; and a step S6 for calculating a movement amount of the valve stem 61 from a reference position to a position where the sub-valve 62 is fully opened.

[0157] With the above method (1), by detecting the acceleration of the valve stem 61, it is possible to detect the time at which the sub-valve 62 is fully opened without disassembling the steam valve 14 while continuing the operation of the steam turbine 10. Furthermore, with the above method (1), the time at which the sub-valve 62 is fully opened can be accurately detected by detecting the acceleration of the valve stem 61. This improves the accuracy of calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, and improves the accuracy of measuring the wear on the steam valve 14.

[0158] (2) In some embodiments according to the above method (1), the reference position is preferably a position of the valve stem 61 when the sub-valve 62 starts to open.

[0159] With the above method (2), by setting the reference position to the position of the valve stem 61 when the sub-valve 62 starts to open, it is possible to relatively accurately specify the reference position to be referred to when calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, thereby improving the accuracy of the amount of movement of the valve stem 61 from the calculated reference position to the position where the sub-valve 62 is fully opened.

[0160] (3) In some embodiments according to the above method (2), the measuring method for the steam valve preferably includes: a step S1 of measuring a strain on the valve stem 61 when the sub-valve 62 is opened by driving the valve stem 61 with the actuator 46B from the fully closed state of the main valve 64 and the sub-valve 62; and a step S4 of detecting a timing at which the sub-valve 62 starts to open based on the measured strain on the valve stem 61.

[0161] Since a relatively large force is required to open the sub-valve 62 with the above method (3), the strain on the valve stem 61 can be measured relatively easily when the sub-valve 62 is open. Therefore, the timing at which the sub-valve 62 starts to open is easily detected. In addition, the accuracy of detecting the timing at which the sub-valve 62 starts to open can be improved by measuring the strain on the valve stem 61 when the sub-valve 62 is open.

[0162] (4) In some embodiments according to the above method (2), the measuring method for the steam valve preferably includes: a step S4 of detecting a time point at which the sub-valve 62 starts to open based on the measured acceleration of the valve stem 61.

[0163] Since, for example, with the above method (4), it is possible to detect the timing at which the sub-valve 62 starts to open and the timing at which the sub-valve 62 is fully opened based on the measurement result of the same acceleration sensor 101, it is possible to simplify the device configuration for detecting these timings. With the above method (4), it is possible to omit the difficulty in measuring the strain on the valve stem 61 compared to the case where the timing at which the sub-valve 62 starts to open is detected based on the strain, for example.

[0164] (5) In some embodiments according to the above method (2), the actuator 46B is preferably a hydraulic actuator. The measuring method for the steam valve may include: a step S8 of measuring a pressure of pressurized oil supplied to the hydraulic actuator (actuator 46B) when the sub-valve 62 is opened by driving the valve stem 61 with the actuator 46B from the fully closed state of the main valve 64 and the sub-valve 62; and a step S4 of detecting a timing at which the sub-valve 62 starts to open based on the measured pressure of the pressurized oil.

[0165] Since the above method (5) relatively easily measures the pressure of the pressurized oil supplied to the hydraulic actuator (actuator 46B), it is possible to relatively easily detect the timing at which the sub-valve 62 starts to open. Furthermore, the above method (5) makes it possible to omit the difficulty in measuring the strain on the valve stem 61 compared to the case where the timing at which the sub-valve 62 starts to open is detected based on the strain, for example.

[0166] (6) In some embodiments according to the above method (1), the reference position may be a position of the valve stem 61 when the main valve 64 and the sub-valve 62 are in the fully closed state.

[0167] With the above method (6), the reference position is easily set and detected.

[0168] (7) In some embodiments according to any one of the above methods (1) to (6), the step S6 of calculating the movement amount of the valve stem 61 preferably includes calculating the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened based on a change in the position of the valve stem 61 detected by a displacement measuring device 105.

[0169] With the above method (7), the accuracy for detecting the position of the valve stem 61 relatively increases, thereby making it possible to improve the accuracy for calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened.

[0170] (8) In some embodiments according to any one of the above methods (1) to (6), the step S8 for calculating the movement amount of the valve stem 61 may include calculating the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened based on known movement speed information (valve opening speed information) of the valve stem 61.

[0171] With the above method (8), it is possible to omit the displacement measuring device 105 for detecting the position of the valve stem 61.

[0172] (9) A measuring device 100 for a steam valve according to at least one embodiment of the present invention is a measuring device for a steam valve 14, comprising: a valve body 41 having a steam flow path 52 through which steam flows, and a valve seat 48 arranged in the center of the steam flow path 52 and having an opening portion;a stop valve 45 including a valve stem 61 extending in an axial direction Z where an axis O1, O2 extends and can be moved back and forth in the axial direction Z, a sub-valve 62 disposed at a distal end of the valve stem 61 in a distal end portion 61A of the valve stem 61, and a main valve 64 including a through portion 71A where a part of the distal end portion 61A of the valve stem 61, which is located closer to a proximal end side of the valve stem 61 than the distal end, is inserted, closes the steam flow path 52 by being brought into contact with the valve seat 48, and is formed with a through hole 71B where steam flows in when the sub-valve 62 is opened;and an actuator 46B for driving the valve stem 61. The steam valve measuring device 100 according to at least one embodiment of the present invention includes: an acceleration sensor 101 for measuring an acceleration of the valve stem 61; a first detection unit 121 for detecting a time at which the sub-valve 62 is fully opened based on the acceleration of the valve stem 61 measured by the acceleration sensor 101; and a calculation unit 123 for calculating a movement amount of the valve stem 61 from a reference position to a position where the sub-valve 62 is fully opened.

[0173] With the above configuration (9), by detecting the acceleration of the valve stem 61, it is possible to detect the time at which the sub-valve 62 is fully opened without disassembling the steam valve 14 while continuing the operation of the steam turbine 10. Furthermore, with the above configuration (9), the time at which the sub-valve 62 is fully opened can be accurately detected by detecting the acceleration of the valve stem 61. This improves the accuracy of calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, and improves the accuracy of measuring the wear on the steam valve 14.

[0174] (10) In some embodiments according to the above configuration (9), the measuring device for the steam valve preferably includes: a second detection unit 122 for detecting a timing at which the sub-valve 62 starts to open. The calculation unit 123 is preferably configured to calculate the movement amount of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, with the timing at which the sub-valve 62 starts to open detected by the second detection unit 122 serving as the reference position.

[0175] With the above configuration (10), by setting the reference position to the position of the valve stem 61 when the sub-valve 62 starts to open, it is possible to relatively accurately specify the reference position to be referred to when calculating the amount of movement of the valve stem 61 from the reference position to the position where the sub-valve 62 is fully opened, thereby improving the accuracy of the amount of movement of the valve stem 61 from the calculated reference position to the position where the sub-valve 62 is fully opened. List of reference symbols 10 steam turbine 11 boilers 14 Steam valve 41 Valve body 43 Control valve 45 Stop valve 46A, 46B Actuator 48 Valve seat 52 Steam flow path 61 Valve stem 61A Distal end section 62 secondary valve 64 Main valve 71A through section 71B Through hole 100 measuring device 101 Accelerometer 103 Strain sensor 105 Displacement measuring device 110 Control 121 First registration unit 122 Second recording unit 123 Calculation unit 124 valuation unit

Claims

[1] A measuring method for a steam valve (14), comprising: a valve body (41) comprising a steam flow path (52) through which steam flows, and a valve seat (48) arranged in the center of the steam flow path (52) and having an opening portion; a stop valve (45) comprising a valve stem (61) extending in an axial direction where an axis extends and can be moved back and forth in the axial direction, a sub-valve (62) arranged at a distal end of the valve stem (61) in a distal end portion (61A) of the valve stem (61), and a main valve (64) comprising a through portion (71A) where a part of the distal end portion (61A) of the valve stem (61) that is closer to a proximal end side of the valve stem (61) than the distal end is inserted, closes the steam flow path (52) by being brought into contact with the valve seat (48), and is formed with a through hole (71B) where steam flows in when the sub-valve (62) is opened; and an actuator (46A, 46B) for driving the valve stem (61), wherein the measuring method for the steam valve (14) comprises: a step of measuring an acceleration of the valve stem (61) when the sub-valve (62) is opened by driving the valve stem (61) with the actuator (46A, 46B) from a fully closed state of the main valve (64) and the sub-valve (62); a step of detecting a time at which the sub-valve (62) is fully opened based on the measured acceleration of the valve stem (61); and a step of calculating a movement amount of the valve stem (61) from a reference position to a position where the sub-valve (62) is fully opened. [2] The measuring method for the steam valve (14) according to claim 1, wherein the reference position is a position of the valve stem (61) when the sub-valve (62) starts to open. [3] The measuring method for the steam valve (14) according to claim 2, comprising: a step of measuring a strain on the valve stem (61) when the sub-valve (62) is opened by driving the valve stem (61) with the actuator (46A, 46B) from the fully closed state of the main valve (64) and the sub-valve (62); and a step of detecting a time at which the sub-valve (62) starts to open based on the measured strain on the valve stem (61). [4] The measuring method for the steam valve (14) according to claim 2, comprising: a step of detecting a time at which the sub-valve (62) starts to open based on the measured acceleration of the valve stem (61). [5] The measuring method for the steam valve (14) according to claim 2, wherein the actuator (46A, 46B) is a hydraulic actuator, and wherein the measuring method for the steam valve (14) comprises: a step of measuring a pressure of pressurized oil supplied to the hydraulic actuator when the sub-valve (62) is opened by driving the valve stem (61) with the actuator (46A, 46B) from the fully closed state of the main valve (64) and the sub-valve (62); and a step of detecting a timing at which the sub-valve (62) starts to open based on the measured pressure of the pressure oil. [6] The measuring method for the steam valve (14) according to claim 1, wherein the reference position is a position of the valve stem (61) when the main valve (64) and the sub-valve (62) are in the fully closed state. [7] The measuring method for the steam valve (14) according to any one of claims 1 to 6, wherein the step of calculating the amount of movement of the valve stem (61) comprises calculating the amount of movement of the valve stem (61) from the reference position to the position where the sub-valve (62) is fully opened based on a change in the position of the valve stem (61) detected by a displacement measuring device (105). [8] The measuring method for the steam valve (14) according to any one of claims 1 to 6, wherein the step of calculating the movement amount of the valve stem (61) comprises calculating the movement amount of the valve stem (61) from the reference position to the position where the sub-valve (62) is fully opened based on known movement speed information of the valve stem (61). [9] A measuring device (100) for a steam valve (14), comprising: a valve body (41) comprising a steam flow path (52) through which steam flows, and a valve seat (48) arranged in the center of the steam flow path (52) and having an opening portion; a stop valve (45) comprising a valve stem (61) extending in an axial direction where an axis extends and can be moved back and forth in the axial direction, a sub-valve (62) arranged at a distal end of the valve stem (61) in a distal end portion (61A) of the valve stem (61), and a main valve (64) comprising a through portion (71A) where a part of the distal end portion (61A) of the valve stem (61) that is closer to a proximal end side of the valve stem (61) than the distal end is inserted, closes the steam flow path (52) by being brought into contact with the valve seat (48), and is formed with a through hole (71B) where steam flows in when the sub-valve (62) is opened; and an actuator (46A, 46B) for driving the valve stem (61), wherein the measuring device (100) for the steam valve (14) comprises: an acceleration sensor (101) for measuring an acceleration of the valve stem (61); a first detection unit (121) for detecting a time at which the sub-valve (62) is fully opened based on the acceleration of the valve stem (61) measured by the acceleration sensor (101); and a calculation unit (123) for calculating a movement amount of the valve stem (61) from a reference position to a position where the sub-valve (62) is fully opened. [10] The measuring device (100) for the steam valve (14) according to claim 9, comprising: a second detection unit (122) for detecting a time at which the sub-valve (62) starts to open, wherein the calculation unit (123) is configured to calculate the movement amount with the timing at which the sub-valve (62) starts to open detected by the second detection unit (122) serving as the reference position.

Images