Steam valves and power generation systems

Abstract

A steam valve according to at least one embodiment of the present disclosure comprises: a valve body including a steam passage for passing steam and a valve seat that is provided at a midpoint of the steam passage and has an opening; a valve stem that extends in an axial direction along which the axis of the valve stem extends and can move forward and backward in the axial direction; and a stop valve including a first valve body that is fixed at the distal end portion of the valve stem and is brought into contact with the valve seat to close the steam passage. The valve stem is divided into two valve stems: a first valve stem on which the first valve body is fixed and a second valve stem different from the first valve stem. The positions of division of the first valve stem and the second valve stem in the axial direction are located outside a pressure boundary separated from the steam passage in terms of pressure.

Description

[Technical field]

[0001] The present disclosure relates to a steam valve and a power generation system. This application claims priority based on Patent Application No. 2022-014352, filed with the Japan Patent Office on February 1, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] For example, in a power generation system using a steam turbine, a steam valve is used to adjust the amount of steam supplied to drive the steam turbine in response to load changes and to stop the supply of steam to the steam turbine in the event of an abnormality. A steam valve is typically configured to include a valve seat having an opening, a valve stem that moves a valve element provided opposite the opening of the valve seat in a direction toward and away from the valve seat, and a cylindrical support member that slidably supports the valve stem. In a steam valve configured in this way, it is important to suppress wear due to rotation of the valve element caused by steam, rattling, etc.

[0003] An example of the structure of this type of steam valve is found in Patent Document 1. This document discloses a steam valve (main steam stop valve) for a steam turbine in which the plane of the valve disc (plane parallel to the axial direction of the valve rod) and the plane of the valve rod (plane parallel to the axial direction of the valve rod) are in surface contact with each other at the fitting portion between the valve disc and the valve rod. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-70513 A Summary of the Invention [Problem to be solved by the invention]

[0005] Some steam valves have a stop valve equipped with a valve stem, a child valve arranged at the tip of the valve stem, and a parent valve having a through hole through which steam flows when the child valve is opened (a configuration corresponding to the valve body disclosed in Patent Document 1). In such steam valves, the child valve connected to an actuator opens before the parent valve, thereby opening the through hole provided in the parent valve, thereby reducing the pressure difference between the upstream and downstream of the parent valve and facilitating the opening operation of the parent valve.

[0006] In a steam valve having the above configuration, from the viewpoint of suppressing wear of the stop valve, it is important to support the parent valve so that it does not rotate or rattle relative to the valve stem when the child valve and parent valve are open. However, in the valve structure disclosed in the above Patent Document 1, the valve stem and the valve body are engaged so that their flat surfaces come into contact with each other at the fitting portion, so that it is difficult to support the parent valve so that it does not rotate or rattle relative to the valve stem when the child valve and parent valve are fully open. Therefore, when the child valve and parent valve are fully open, the parent valve comes into contact with the valve stem, which may cause wear of the stop valve.

[0007] In view of the above circumstances, at least one embodiment of the present disclosure has an object to provide a steam valve and a power generation system that can suppress wear of a stop valve when the stop valve is in a fully open state. [Means for solving the problem]

[0008] (1) At least one embodiment of the steam valve according to the present disclosure comprises: a valve body including a steam flow passage through which steam flows and a valve seat provided midway along the steam flow passage and having an opening; a stop valve including a valve stem extending in an axial direction along which an axis extends and capable of moving forward and backward in the axial direction, and a first valve body fixed to a tip portion of the valve stem and abutting against the valve seat to close the steam flow path; Equipped with The valve rod is divided into a first valve rod to which the first valve body is fixed and a second valve rod different from the first valve rod, The position where the first valve rod and the second valve rod are divided in the axial direction is located outside a pressure boundary that is pressure-separated from the steam flow path.

[0009] (2) A power generation system according to at least one embodiment of the present disclosure, A steam valve having the configuration of (1) above; A boiler for generating steam; a steam turbine driven by the steam; a steam supply pipe connecting the boiler and the steam turbine and supplying the steam to the steam turbine; Equipped with The steam valve is provided on the steam supply pipe. Effect of the Invention

[0010] According to at least one embodiment of the present disclosure, wear of the stop valve can be suppressed when the stop valve is in a fully open state. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a power generation system according to an embodiment; [Diagram 2] 1 is a cross-sectional view showing the configuration of a steam valve according to a first embodiment, with a first valve body in a closed state. [Figure 3A] FIG. 3 is an enlarged view of area A in FIG. [Figure 3B] FIG. 3 is an enlarged view of area A in FIG. [Figure 3C] FIG. 3 is an enlarged view of area A in FIG. [Figure 4A] FIG. 3 is an enlarged view of region B in FIG. [Figure 4B] FIG. 3 is an enlarged view of region B in FIG. [Diagram 5] FIG. 6 is a cross-sectional view showing the configuration of a steam valve according to a second embodiment, with both the first valve body and the second valve body in a closed state. [Figure 6A] FIG. 6 is an enlarged view of region C in FIG. 5. [Figure 6B] FIG. 6 is an enlarged view of region C in FIG. 5. [Figure 7A] FIG. 6 is an enlarged view of region D in FIG. 5. [Figure 7B] FIG. 6 is an enlarged view of region D in FIG. 5. [Figure 8A] FIG. 6 is an enlarged view of region E in FIG. 5. [Figure 8B] FIG. 6 is an enlarged view of region E in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions excluding the presence of other elements.

[0013] (Overall configuration of power generation system) First, a power generation system 1 to which a steam valve 14 according to at least one embodiment of the present disclosure is applied will be described. Fig. 1 is a schematic configuration diagram of the power generation system 1 according to one embodiment. The power generation system 1 includes a steam turbine 10, a boiler 11, and a generator 26.

[0014] The steam turbine 10 is a turbine driven by steam generated in a boiler 11. The steam turbine 10 is connected to the boiler 11 via a first steam supply pipe 12, and is driven by being supplied with high-pressure steam generated by burning fuel in the boiler 11. A steam valve 14 for adjusting the flow rate of steam supplied to the steam turbine 10 is provided on the first steam supply pipe 12. The configuration of the steam valve 14 will be described in detail later, and includes a regulator valve 43 and a stop valve 45.

[0015] In this embodiment, a multi-stage turbine is exemplified as the steam turbine 10, and the steam turbine 10 includes, from the upstream side of the steam flow path, a high-pressure steam turbine 31, an intermediate-pressure steam turbine 32, and a low-pressure steam turbine 33. The high-pressure steam turbine 31 is driven by steam (high-pressure steam generated in the boiler 11) supplied from a first steam supply pipe 12. The steam that has completed its work in the high-pressure steam turbine 31 is supplied to the intermediate-pressure steam turbine 32 via a second steam supply pipe 16. A reheater 18 is provided in the second steam supply pipe 16.

[0016] The intermediate-pressure steam turbine 32 is driven by steam supplied from the second steam supply piping 16 (steam that has completed its work in the high-pressure steam turbine 31). The steam that has completed its work in the intermediate-pressure steam turbine 32 is supplied to the low-pressure steam turbine 33 via the third steam supply piping 25. The low-pressure steam turbine 33 is driven by steam supplied from the third steam supply piping 25 (steam that has completed its work in the intermediate-pressure steam turbine 32).

[0017] Each turbine (high-pressure steam turbine 31, intermediate-pressure steam turbine 32, and low-pressure steam turbine 33) that constitutes the steam turbine 10 has a common rotating shaft 35. A generator 26 is connected to the rotating shaft 35, and the generator 26 is driven by the rotation of each turbine to generate electricity.

[0018] (Configuration of the steam valve 14 according to the first embodiment) Next, the configuration of the steam valve 14 according to the first embodiment will be described with reference to Fig. 2 to Fig. 4B. Fig. 2 is a cross-sectional view showing the configuration of the steam valve 14 according to the first embodiment when the first valve body 71 is in a closed state, Figs. 3A, 3B, and 3C are enlarged views of area A in Fig. 2, and Figs. 4A and 4B are enlarged views of area B in Fig. 2. Fig. 3A shows a state when the stop valve 45 starts to open from a fully closed state, Figs. 3B and 4A show a state when the stop valve 45 is fully closed, and Figs. 3C and 4B show a state when the stop valve 45 is fully open.

[0019] 2 to 4B and 5 to 8B showing a steam valve 14 according to a second embodiment described later, O1 is the axis of the valve stem 60 constituting the stop valve 45, and O2 is the axis of the valve stem 55 constituting the regulating valve 43. The direction in which the axes O1 and O2 extend (hereinafter referred to as the "axial direction Z") is, for example, a substantially vertical direction.

[0020] As shown in Fig. 2, the steam valve 14 according to the first embodiment includes a valve body 41, a regulating valve 43, a stop valve 45, and actuators 46A and 46B. The valve body 41 has a flow path partitioning section 47 and a valve seat 48. The flow path partitioning section 47 partitions a steam flow path 52 and accommodates a part (tip side) of the regulating valve 43 and a part (tip side) of the stop valve 45. The steam flow path 52 has an inlet section 52A and an outlet section 52B. The inlet section 52A is connected to the boiler 11 via one side of the first steam supply pipe 12, and high-pressure steam generated in the boiler 11 is introduced therein. The outlet section 52B is connected to the high-pressure steam turbine 31 via the other side of the first steam supply pipe 12. The amount of steam supplied from the boiler 11 to the high-pressure steam turbine 31 via the first steam supply pipe 12 can be adjusted by controlling the opening degree of the regulating valve 43 in the steam valve 14 provided in the first steam supply pipe 12 while the stop valve 45 is open.

[0021] The flow passage partition portion 47 includes a first guide member 47A and a second guide member 47B. The first guide member 47A is provided so as to cover the outer peripheral surface of a portion of the valve rod 55 constituting the regulating valve 43 that is not exposed to the steam flow passage 52. The first guide member 47A functions as a guide that guides the valve rod 55 in the axial direction Z. The second guide member 47B is provided so as to cover the outer peripheral surface of the rod-shaped portion 60B constituting the stop valve 45. The second guide member 47B functions as a guide that guides the valve rod 60 in the axial direction Z. In the steam valve 14 according to the first embodiment, the second guide member 47B protrudes into the steam flow passage 52.

[0022] The valve seat 48 is provided in a flow path partition section 47 located midway through the steam flow path 52. The valve seat 48 has a ring shape centered on the axis O1, and is configured so that the axis of the valve seat 48 coincides with the axis O1. That is, the valve seat 48 has an opening centered on 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 first valve body 71 constituting the stop valve 45 and the tip 56A of the regulating valve main body 56 constituting the regulating valve 43 can each abut against the valve seat surface 48a.

[0023] (Control valve 43) The control valve 43 is disposed upstream of the position where the stop valve 45 is disposed in the steam flow direction. The control valve 43 has a valve rod 55 and a control valve body 56. The valve rod 55 extends in the axial direction Z, and the tip side is disposed in the steam flow path 52. The axis O1 of the valve rod 55 is configured to coincide with the axis O2 of the valve rod 55 of the stop valve 45. The valve rod 55 is movable in the axial direction Z.

[0024] The regulating valve body 56 is provided on the tip side of the valve stem 55. The portion of the regulating valve body 56 located on the valve seat 48 side has a cylindrical shape, and has a tip 56A that can abut against the valve seat surface 48a of the valve seat 48. The regulating valve 43 having this configuration has the function of adjusting the flow rate of high-pressure steam supplied to the high-pressure steam turbine 31 in accordance with the load of the steam turbine 10 by controlling the distance between the tip 56A of the regulating valve body 56 and the valve seat 48 by moving the valve stem 55 along the axial direction Z using the actuator 46A.

[0025] (Stop valve 45) The stop valve 45 is disposed inside the regulator valve 43. The stop valve 45 includes a valve stem 60 and a first valve body 71.

[0026] (Stem 60) The valve rod 60 extends in the axial direction Z and has a tip portion 60A and a rod-shaped portion 60B that is closer to the base end than the tip portion 60A. The tip portion 60A has a shape that can engage with the first valve body 71 to fix the first valve body 71. The rod-shaped portion 60B extends along the axial direction Z. The base end of the rod-shaped portion 60B is connected to the actuator 46B. The valve rod 60 having the tip portion 60A and the rod-shaped portion 60B is thus divided into a first valve rod 61 and a second valve rod 62, as will be described in detail later, and the first valve rod 61 and the second valve rod 62 can advance and retreat in the axial direction Z. In the following description, the upper side in the axial direction Z in FIG. 2 is referred to as the tip side, and the lower side in FIG. 2 is referred to as the base side.

[0027] In the steam valve 14 according to the first embodiment, the first valve rod 61 is located on the tip side of the valve rod 60 which is divided into two parts, and the first valve body 71 is fixed to the tip portion 61A. In the steam valve 14 according to the first embodiment, the second valve rod 62 is located on the base end side of the valve rod 60 which is divided into two parts, and an actuator 46B is connected to the base end part 62B.

[0028] As shown clearly in FIGS. 3A to 3C, a base end 61B of the first valve stem 61 is connected to a tip end 62A of the second valve stem 62. The base end 61B of the first valve rod 61 and the tip end 62A of the second valve rod 62 overlap in the axial direction Z. In the steam valve 14 according to the first embodiment, the base end 61B of the first valve rod 61 has a small diameter portion 611 formed so that the outer diameter is smaller in a region near the end on the base end side than in a region on the tip side. Also, in the steam valve 14 according to the first embodiment, the base end 62B of the second valve rod 62 has a cylindrical portion 621 formed in a cylindrical shape so as to surround the outer periphery of the small diameter portion 611 of the first valve rod 61. In the steam valve 14 according to the first embodiment, the small diameter portion 611 of the first valve rod 61 and the cylindrical portion 621 of the second valve rod 62 are configured to be relatively movable in the axial direction Z. In addition, a gap is provided between the outer circumferential surface of the small diameter portion 611 of the first valve rod 61 and the inner circumferential surface of the cylindrical portion 621 of the second valve rod 62, allowing steam to flow through the steam flow passage 52 as described below.

[0029] In the steam valve 14 of the first embodiment, the first valve rod 61 has a first opening pressure surface 613 that is pressed in the axial direction Z by the second valve rod 62 when the second valve rod 62 moves from the base end side to the tip end side of the valve rod 60. In the steam valve 14 of the first embodiment, the second valve rod 62 has a second opening pressure surface 623 that presses the first opening pressure surface 613 in the axial direction Z when the second valve rod 62 moves from the base end side to the tip end side of the valve rod 60.

[0030] In the steam valve 14 of the first embodiment, the first opening pressure surface 613 is formed at a position extending from the small diameter portion 611 to a region extending from the small diameter portion 611 to the tip side, and is, for example, a conical inclined surface that expands the outer diameter of the first valve rod 61 as it moves from the base end side of the valve rod 60 toward the tip side. In the steam valve 14 of the first embodiment, the second opening pressure surface 623 is formed at the tip of the tubular portion 621 and is, for example, a conical inclined surface that expands the inner diameter of the inner surface of the tubular portion 621 as it moves from the base end side to the tip end side of the valve rod 60. The first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 are formed to be able to come into contact with each other without any gap. Note that the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 may be inclined surfaces having a spherical shape instead of a conical inclined surface.

[0031] In the steam valve 14 according to the first embodiment, the first valve rod 61 has a first closing-time pressing surface 615 that is pressed in the axial direction Z by the second valve rod 62 when the stop valve 45 is fully closed. The second valve rod 62 has a second closing-time pressing surface 625 that presses the first closing-time pressing surface 615 in the axial direction Z when the stop valve 45 is fully closed. In the steam valve 14 of the first embodiment, the first closing pressure surface 615 is formed at the base end side end of the small diameter portion 611, and is, for example, a conical inclined surface that expands the outer diameter of the first valve rod 61 (small diameter portion 611) as it moves from the tip side to the base end side of the valve rod 60. In the steam valve 14 of the first embodiment, the second closing pressure surface 625 is formed on the base end side of the tubular portion 621, and is, for example, a conical inclined surface that expands the inner diameter of the inner surface of the tubular portion 621 as it moves from the tip side of the valve rod 60 toward the base end side. The first valve-closing pressing surface 615 and the second valve-closing pressing surface 625 are formed to be able to come into contact with each other without any gap. Note that the first valve-closing pressing surface 615 and the second valve-closing pressing surface 625 may be inclined surfaces having a spherical shape instead of conical inclined surfaces. In the steam valve 14 of the first embodiment, the dividing position Pz in the axial direction Z of the first valve rod 61 and the second valve rod 62 is the abutment position between the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623, or the abutment position between the first valve-closing pressing surface 615 and the second valve-closing pressing surface 625.

[0032] For example, when the second valve rod 62 is driven toward the tip side by the actuator 46B and the second valve rod 62 presses the first valve rod 61 toward the tip side, or when the stop valve 45 is fully open as shown in Figure 3C, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z so as to approach each other, so that the first open-valve pressing surface 613 and the second open-valve pressing surface 623 abut and come into close contact, and the first closed-valve pressing surface 615 and the second closed-valve pressing surface 625 move away from each other.

[0033] For example, when the second valve rod 62 is driven toward the base end by the actuator 46B so that the second valve rod 62 pulls the first valve rod 61 toward the base end, or when the stop valve 45 is fully closed as shown in FIG. 3B, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z away from each other, causing the first valve-open pressing surface 613 and the second valve-open pressing surface 623 to separate, and the first valve-closed pressing surface 615 and the second valve-closed pressing surface 625 to come into contact and be in close contact with each other.

[0034] For example, when the stop valve 45 is in a fully closed state and the actuator 46B begins to drive the second valve rod 62 toward the tip side, as shown in FIG. 3A, the first open-valve pressing surface 613 and the second open-valve pressing surface 623 are separated, and the first closed-valve pressing surface 615 and the second closed-valve pressing surface 625 are separated.

[0035] (Through hole 617 of first valve stem 61) In the steam valve 14 according to the first embodiment, the first valve rod 61 has a through hole 617 penetrating from the tip 610a to the base end 610b of the first valve rod 61. An end opening 617a on the tip side of the through hole 617 faces the steam flow path 52 upstream of the stop valve 45. An end opening 617b on the base end side of the through hole 617 faces an inner periphery 621a of the cylindrical portion 621 of the second valve rod 62.

[0036] (First inclined surface 619 of first valve stem 61) 4A and 4B, in the steam valve 14 according to the first embodiment, the first valve rod 61 has a first inclined surface 619 on the tip side in the region whose outer circumferential surface is covered by the second guide member 47B, which increases the outer diameter of the valve rod 60 (first valve rod 61) from the tip side toward the base end side of the valve rod 60. The first inclined surface 619 is a conical inclined surface. In the steam valve 14 according to the first embodiment, the second guide member 47B has a first abutment surface 471 that abuts against the first inclined surface 619 of the first valve rod 61 when the stop valve 45 is fully open, as shown in Fig. 4B. The first abutment surface 471 is a conical inclined surface formed so that the inner diameter of the first abutment surface 471 increases from the tip side toward the base end side. The first inclined surface 619 and the first abutment surface 471 are formed to be able to abut against each other without any gap. Note that the first inclined surface 619 and the first abutment surface 471 may be inclined surfaces having a spherical shape instead of conical inclined surfaces.

[0037] (Regarding the operation of the stop valve 45 of the steam valve 14 according to the first embodiment) In the steam valve 14 according to the first embodiment, the stop valve 45 operates as follows. When adjusting the flow rate of steam with the regulating valve 43 in the steam valve 14, the stop valve 45 is opened before the regulating valve 43 is opened.

[0038] (When fully closed) As shown in FIG. 2, when the stop valve 45 is fully closed, the first valve body 71 abuts against the valve seat surface 48a of the valve seat 48. Therefore, the first valve rod 61 to which the first valve body 71 is fixed is restricted from moving toward the base end. The second valve rod 62 is biased toward the base end by the biasing force of a closing spring (not shown). Therefore, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z so as to move away from each other, and as shown in FIG. 3B, the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 are separated, and the first valve-closing pressing surface 615 and the second valve-closing pressing surface 625 abut against each other and come into close contact with each other. As described above, the end opening 617a on the tip side of the through hole 617 faces the steam flow path 52, so steam in the steam flow path 52 upstream of the first valve body 71 can flow from the end opening 617b on the base end side through the through hole 617 into the inner periphery 621a of the tubular portion 621 of the second valve rod 62. However, when the stop valve 45 is fully closed, as described above, the first valve-closing-time pressing surface 615 and the second valve-closing-time pressing surface 625 are in contact and in close contact with each other, so that steam does not flow out to the tip side of the first valve-closing-time pressing surface 615 and the second valve-closing-time pressing surface 625.

[0039] (When the stop valve 45 starts to open from a fully closed state) 2, 3B, and 4A, when the second valve rod 62 starts to be driven toward the tip side by the actuator 46B, the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 are separated, and the first valve-closing pressing surface 615 and the second valve-closing pressing surface 625 are separated, as shown in FIG. 3A. Therefore, the steam that has flowed into the inner periphery 621a of the cylindrical portion 621 of the second valve rod 62 through the through hole 617 is led to, for example, the high-pressure stem leak system 81 through the gap between the small diameter portion 611 of the first valve rod 61 and the inner periphery of the cylindrical portion 621 of the second valve rod 62, and the gap between the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623. This reduces the pressure difference between the upstream and downstream sides of the first valve body 71, facilitating the subsequent opening operation of the first valve body 71.

[0040] (From when the stop valve 45 begins to open until it is fully open) When the second valve rod 62 is further driven toward the tip side by the actuator 46B from the state in which the stop valve 45 begins to open as described above, the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 come into contact with each other as shown in Fig. 3C. Therefore, when the second valve rod 62 is further driven toward the tip side by the actuator 46B, the first valve rod 61 is driven toward the tip side by the driving force of the actuator 46B transmitted via the second valve rod 62. As a result, the first valve body 71 fixed to the first valve rod 61 moves toward the tip side and separates from the valve seat surface 48a of the valve seat 48.

[0041] (When fully open) When the second valve rod 62 is further driven toward the tip side by the actuator 46B, the stop valve 45 becomes fully open. When the stop valve 45 is in a fully open state, as shown in FIG. 4B, the first inclined surface 619 of the first valve rod 61 abuts against the first abutment surface 471 of the second guide member 47B without any gap. This restricts the movement of the first valve rod 61 and the first valve body 71 toward the tip side. The first valve rod 61 is also urged toward the tip side by the driving force of the actuator 46B. Therefore, the first inclined surface 619 and the first abutment surface 471 are pressed against each other without any gap. Therefore, a pressure boundary 49 is formed by the first inclined surface 619 and the first abutment surface 471. This pressure boundary 49 pressure-wise separates the steam flow path 52 and the inner periphery 473 of the second guide member 47B.

[0042] (during closing operation) When the stop valve 45 is closed, when the second valve rod 62 is driven toward the base end by the actuator 46B, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z away from each other, causing the first valve-opening pressing surface 613 and the second valve-opening pressing surface 623 to separate, and the first valve-closed pressing surface 615 and the second valve-closed pressing surface 625 to come into contact. Therefore, when the second valve rod 62 is further driven toward the base end side by the actuator 46B, the first valve rod 61 and the first valve body 71 start to move toward the base end side. Thereafter, the first valve rod 61 and the first valve body 71 move toward the base end side until the first valve body 71 abuts against the valve seat surface 48a of the valve seat 48.

[0043] Thus, in the steam valve 14 of the first embodiment, the dividing position Pz in the axial direction Z of the first valve rod 61 and the second valve rod 62 is located outside the pressure boundary 49 which is pressure-separated from the steam flow path 52. In the steam valve 14 of the first embodiment, the first valve body 71 is fixed to the first valve rod 61, so that no wear occurs between the first valve body 71 and the first valve rod 61, and since the axial division position Pz of the first valve rod 61 and the second valve rod 62 is located outside the pressure boundary 49, the division position Pz is not exposed to the steam flow path 52 through which high-pressure steam may flow at high speed, so that wear at the division position Pz is effectively suppressed.

[0044] In the steam valve 14 according to the first embodiment, the pressure boundary 49 is formed by the first inclined surface 619 and the first contact surface 471. This allows the pressure boundary 49 to be formed by utilizing a configuration for limiting the range of movement of the valve stem 60 towards the tip side, thereby simplifying the configuration of the steam valve 14.

[0045] In the steam valve 14 according to the first embodiment, the first contact surface 471 is formed on the second guide member 47B, which is a cylindrical support member that supports the valve rod 60 so that it can slide freely. This allows a pressure boundary 49 to be formed by the second guide member 47B, which is a support member for the valve rod, and the valve rod 60 (first valve rod 61).

[0046] In the steam valve 14 according to the first embodiment, the first valve rod 61 has a first valve-opening pressing surface 613, and the second valve rod 62 has a second valve-opening pressing surface 623. As a result, even if the valve stem 60 is divided into the first valve stem 61 and the second valve stem 62, the first valve stem 61 can be moved by the second valve stem 62 from the base end side of the valve stem 60 towards the tip end side.

[0047] In the steam valve 14 of the first embodiment, when the stop valve 45 is fully open, the first valve rod 61 is clamped between the first abutment surface 471 of the second guide member 47B and the second open valve pressing surface 623 of the second valve rod 62 and fixed to the second guide member 47B. As a result, when the stop valve 45 is fully open, the first valve rod 61 and the first valve body 71 fixed to the first valve rod 61 are fixed to the second guide member 47B, thereby suppressing vibration of the first valve rod 61 and the first valve body 71. In addition, since the first valve rod 61 is fixed to the second guide member 47B, wear at the contact portion between the first valve rod 61 and the second guide member 47B can be effectively suppressed.

[0048] In the steam valve 14 of the first embodiment, when the stop valve 45 is fully open, the first open valve pressing surface 613 and the second open valve pressing surface 623 abut each other, thereby preventing steam in the steam flow path 52 from flowing out to the outside through the through hole 617.

[0049] In the steam valve 14 according to the first embodiment, the first valve stem 61 has a first closing-time pressing surface 615 , and the second valve stem 62 has a second closing-time pressing surface 625 . As a result, even if the valve stem 60 is divided into the first valve stem 61 and the second valve stem 62, the first valve stem 61 can be moved from the tip side of the valve stem 60 towards the base end side by the second valve stem 62.

[0050] In the steam valve 14 of the first embodiment, when the stop valve 45 is fully closed, the first closed-valve pressing surface 615 and the second closed-valve pressing surface 625 abut and tightly contact each other, thereby preventing steam in the steam flow path 52 from flowing out to the outside through the through hole 617.

[0051] In the steam valve 14 of the first embodiment, when the stop valve 45 begins to open from a fully closed state, the first closed valve pressing surface 615 and the second closed valve pressing surface 625 separate, and the first open valve pressing surface 613 and the second open valve pressing surface 623 separate, allowing steam in the steam flow path 52 to flow to the outside through the through hole 617. As a result, when the stop valve 45 starts to open from a fully closed state, the steam acting on the stop valve 45 can be released to the outside via the through hole 617, thereby reducing the steam pressure acting on the stop valve 45. In other words, the pressure difference between the upstream and downstream sides of the first valve body 71 is reduced, making it easier to open the first valve body 71.

[0052] (Configuration of the steam valve 14 according to the second embodiment) Next, the configuration of the steam valve 14 according to the second embodiment will be described with reference to Figs. 5 to 8B. Fig. 5 is a cross-sectional view showing the configuration of the steam valve 14 according to the second embodiment in a state in which both the first valve body 171 and the second valve body 172 are in a closed state. Figs. 6A and 6B are enlarged views of region C in Fig. 5. Figs. 7A and 7B are enlarged views of region D in Fig. 5. Figs. 8A and 8B are enlarged views of region E in Fig. 5. Figs. 6A, 7A, and 8A show a state in which the stop valve 45 is fully closed. Fig. 6B shows a state in which the second valve body 172 is open. Fig. 7B shows a state in which the stop valve 45 starts to open from a fully closed state and the second valve rod 162 starts to drive the first valve rod 161. Fig. 8B shows a state in which the stop valve 45 is fully open. In the following description, the same components as those of the steam valve 14 according to the first embodiment are denoted by the same reference numerals as those of the steam valve 14 according to the first embodiment, and detailed description thereof may be omitted.

[0053] In the steam valve 14 according to the second embodiment, the first valve body 171 constituting the stop valve 45 and the tip 56A of the regulating valve main body 56 constituting the regulating valve 43 can each abut against the valve seat surface 48a. In addition, in the steam valve 14 according to the second embodiment, the configuration relating to the regulator valve 43 is the same as that of the steam valve 14 according to the first embodiment.

[0054] (Stop valve 45) The stop valve 45 is disposed inside the regulating valve 43, similar to the steam valve 14 according to the first embodiment. The stop valve 45 includes a valve rod 60, a first valve body 171, and a second valve body 172.

[0055] (Stem 60) The valve rod 60 extends in the axial direction Z and has a tip portion 60A and a rod-shaped portion 60B that is closer to the base end than the tip portion 60A. The tip portion 60A has a shape that can engage with the first valve body 171 to fix the first valve body 171. The rod-shaped portion 60B extends along the axial direction Z. The base end of the rod-shaped portion 60B is connected to the actuator 46B. The valve rod 60 having the tip portion 60A and the rod-shaped portion 60B is thus divided into a first valve rod 161 and a second valve rod 162, as will be described in detail later, and the first valve rod 161 and the second valve rod 162 can advance and retreat in the axial direction Z.

[0056] In the steam valve 14 of the second embodiment, the first valve rod 161 is a hollow valve rod located at the tip side of the split position in the axial direction Z of the two-part valve rod 60, and a first valve body 171 is fixed to the tip portion 161A. The first valve rod 161 has a valve rod insertion hole 614 that penetrates the first valve rod 161 from its base end to its tip, and through which a small diameter portion 162S of the second valve rod 162, which will be described later, is inserted. In the examples shown in Figures 5, 6A, and 6B, the tip of the first valve rod 161 and the base end surface of the first valve body 171 are connected, but the first valve rod 161 may also penetrate the first valve body 171 in the axial direction Z.

[0057] In the steam valve 14 of the second embodiment, the second valve rod 162 has, within the two-part valve rod 60, a large diameter portion 162L located on the base end side of the dividing position in the axial direction Z, and a small diameter portion 162S located on the tip end side of the dividing position in the axial direction Z and having a smaller diameter than the large diameter portion 162L. The small diameter portion 162S is inserted into the valve stem insertion hole 614 of the first valve stem 161. A tip end 162a of the small diameter portion 162S protrudes toward the tip end beyond the tip side surfaces of the first valve rod 161 and the first valve body 171, and the second valve body 172 is fixed thereto. The base end 62B of the second valve rod 162 is connected to an actuator 46B.

[0058] In the steam valve 14 according to the second embodiment, the first valve rod 161 and the second valve rod 162 are configured to be relatively movable in the axial direction Z. That is, the small diameter portion 162S of the second valve rod 162 is inserted slidably in the axial direction Z into the valve rod insertion hole 614 of the first valve rod 161 that covers the outer periphery of the small diameter portion 162S.

[0059] As shown in FIG. 7A, in the steam valve 14 of the second embodiment, the first valve rod 161 has a first open valve pressing surface 616 that is pressed in the axial direction Z by the second valve rod 162 when the second valve rod 162 moves from the base end side toward the tip end side of the valve rod 60. In the steam valve 14 of the second embodiment, the second valve rod 162 has a second opening pressure surface 626 that presses the first opening pressure surface 616 in the axial direction Z when the second valve rod 162 moves from the base end side to the tip end side of the valve rod 60. In the steam valve 14 of the second embodiment, the first open valve pressure surface 616 is formed on the base end 61B of the first valve rod 161, and is, for example, a conical inclined surface that widens the inner diameter of the inner surface of the first valve rod 161 as it moves from the tip side to the base end side of the valve rod 60. In the steam valve 14 of the second embodiment, the second opening pressure surface 626 is formed at the tip of the large diameter portion 162L and is, for example, a conical inclined surface whose outer diameter decreases as it moves from the base end side of the valve rod 60 toward the tip end side. 7B, the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are formed to be able to come into contact with each other. Note that the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 may be inclined surfaces having a spherical shape instead of a conical inclined surface. In the steam valve 14 according to the second embodiment, the dividing position Pz in the axial direction Z of the first valve rod 161 and the second valve rod 162 is the abutting position of the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626.

[0060] (First valve body 171 and second valve body 172) In the steam valve 14 according to the second embodiment, the first valve rod 161 and the second valve rod 162 are configured to be relatively movable in the axial direction Z. Therefore, the first valve body 171 fixed to the first valve rod 161 and the second valve body 172 fixed to the second valve body 172 are configured to be relatively movable in the axial direction Z.

[0061] As shown in Figures 6A and 6B, in the steam valve 14 of the second embodiment, the first valve body 171 has a valve seat surface 74 formed on the tip side surface of the first valve body 171 against which the second valve body 172 can abut. In the steam valve 14 according to the second embodiment, the first valve body 171 has a first valve body through hole 75 that penetrates the first valve body 171 in the axial direction Z. An opening 75a on the tip side of the first valve body through hole 75 faces the steam flow path 52 upstream of the first valve body 171. An opening 75b on the base side of the first valve body through hole 75 faces the steam flow path 52 downstream of the first valve body 171.

[0062] 6A and 6B, in the steam valve 14 according to the second embodiment, the second valve body 172 has an abutment portion 77 that can abut against the valve seat surface 74 of the first valve body 171. The abutment portion 77 is configured in a ring shape when viewed from the axial direction Z. An opening 75a on the tip side of the first valve body through hole 75 is formed radially inward about the axis O1 of the valve rod 60 than the abutment portion 77. Therefore, when the second valve body 172 is in a closed state, that is, when the abutment portion 77 abuts and tightly contacts the valve seat surface 74 of the first valve body 171, the opening 75a on the tip side of the first valve body through hole 75 is isolated from the steam flow path 52 through which high-pressure steam flows, and therefore high-pressure steam does not flow through the first valve body through hole 75.

[0063] For example, when the actuator 46B drives the second valve rod 162 toward the tip side and the second valve rod 162 presses the first valve rod 161 toward the tip side, or when the stop valve 45 is fully open, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z so as to approach each other, so that the first open-state pressing surface 616 and the second open-state pressing surface 626 come into contact as shown in FIG. 7B, and the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 move away from each other as shown in FIG. 6B.

[0064] For example, when the second valve rod 162 is driven toward the base end by the actuator 46B, or when the stop valve 45 is fully closed as shown in Figures 6A, 7A, and 8A, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z away from each other, the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are separated, and the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 abut and come into close contact with each other. The driving force applied by the actuator 46B to drive the second valve rod 162 toward the base end is transmitted to the first valve body 171 and the first valve rod 161 by the abutment portion 77 of the second valve body 172 pressing the valve seat surface 74 of the first valve body 171 toward the base end.

[0065] For example, when the stop valve 45 is in a fully closed state and the actuator 46B begins to drive the second valve rod 162 toward the tip side, as shown in FIG. 6B, the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 separate from each other.

[0066] (First inclined surface 619 of first valve stem 61) 8A and 8B, in the steam valve 14 according to the second embodiment, the first valve rod 161 has a first inclined surface 619 on the tip side in the region whose outer circumferential surface is covered by the second guide member 47B, which increases the outer diameter of the valve rod 60 (first valve rod 161) from the tip side toward the base end side of the valve rod 60. The first inclined surface 619 is a conical inclined surface. In the steam valve 14 according to the second embodiment, the second guide member 47B has a first abutment surface 471 that abuts against the first inclined surface 619 of the first valve rod 161 when the stop valve 45 is fully open, as shown in Fig. 8B. The first abutment surface 471 is a conical inclined surface formed so that the inner diameter of the first abutment surface 471 increases from the tip side toward the base end side. The first inclined surface 619 and the first abutment surface 471 are formed to be able to abut against each other without any gap. Note that the first inclined surface 619 and the first abutment surface 471 may be inclined surfaces having a spherical shape instead of conical inclined surfaces.

[0067] (Regarding the operation of the stop valve 45 of the steam valve 14 according to the second embodiment) In the steam valve 14 according to the second embodiment, the stop valve 45 operates as follows. When adjusting the flow rate of steam with the regulating valve 43 in the steam valve 14, the stop valve 45 is opened before the regulating valve 43 is opened.

[0068] (When fully closed) As shown in FIG. 5, when the stop valve 45 is fully closed, the first valve body 71 abuts against the valve seat surface 48a of the valve seat 48. Therefore, the first valve rod 61 to which the first valve body 71 is fixed is restricted from moving toward the base end. The second valve rod 62 is biased toward the base end by the biasing force of a closing spring (not shown). Therefore, the first valve rod 61 and the second valve rod 62 move relatively in the axial direction Z so as to move away from each other, and the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are separated from each other as shown in FIG. 3B, and the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 abut against each other and come into close contact with each other. When the second valve body 172 is closed, that is, when the abutment portion 77 abuts and is in tight contact with the valve seat surface 74 of the first valve body 171, as described above, the opening 75a at the tip side of the first valve body through hole 75 is isolated from the steam flow path 52 through which high-pressure steam flows, and therefore high-pressure steam does not flow through the first valve body through hole 75.

[0069] (When the stop valve 45 starts to open from a fully closed state) When the actuator 46B starts to drive the second valve rod 162 toward the tip side from the fully closed state of the stop valve 45 shown in FIG. 6A, FIG. 7A, and FIG. 8A, the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 are separated from each other while the first valve body 171 is kept closed, as shown in FIG. 6B. Therefore, high-pressure steam flows into the opening 75a on the tip side of the first valve body through hole 75 from the gap between the valve seat surface 74 and the abutment portion 77. The high-pressure steam that flows into the opening 75a on the tip side of the first valve body through hole 75 is led out to the steam flow passage 52 from the opening 75b on the base end side of the first valve body through hole 75. This reduces the pressure difference between the upstream and downstream sides of the first valve body 171, making it easier to open the first valve body 171.

[0070] (From when the stop valve 45 begins to open until it is fully open) When the second valve rod 162 is further driven toward the tip side by the actuator 46B from the state in which the stop valve 45 begins to open as described above, the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 come into contact with each other as shown in Fig. 7B. Therefore, when the second valve rod 162 is further driven toward the tip side by the actuator 46B, the first valve rod 161 is driven toward the tip side by the driving force of the actuator 46B transmitted via the second valve rod 162. As a result, the first valve body 171 fixed to the first valve rod 161 moves toward the tip side and separates from the valve seat surface 48a of the valve seat 48.

[0071] (When fully open) When the second valve rod 162 is further driven toward the tip side by the actuator 46B, the stop valve 45 becomes fully open. When the stop valve 45 is in a fully open state, as shown in FIG. 8B, the first inclined surface 619 of the first valve rod 161 abuts against the first abutment surface 471 of the second guide member 47B without any gap. This restricts the movement of the first valve rod 161 and the first valve body 171 toward the tip side. In addition, the first valve rod 161 is urged toward the tip side by the driving force of the actuator 46B. Therefore, the first inclined surface 619 and the first abutment surface 471 are pressed against each other without any gap. Therefore, a pressure boundary 49 is formed by the first inclined surface 619 and the first abutment surface 471. This pressure boundary 49 pressure-wise separates the steam flow path 52 and the inner periphery 473 of the second guide member 47B.

[0072] (during closing operation) When the stop valve 45 is closed, when the second valve rod 162 is driven toward the base end by the actuator 46B, the first valve rod 161 and the second valve rod 162 move relatively in the axial direction Z away from each other, the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are separated, and the valve seat surface 74 of the first valve body 171 and the abutment portion 77 of the second valve body 172 abut against each other. Therefore, when the second valve rod 62 is further driven toward the base end side by the actuator 46B, the first valve rod 61 and the first valve body 71 start to move toward the base end side. Thereafter, the first valve rod 161 and the first valve body 171 move toward the base end side until the first valve body 171 abuts against the valve seat surface 48a of the valve seat 48.

[0073] Thus, in the steam valve 14 of the second embodiment, the dividing position Pz in the axial direction Z of the first valve rod 161 and the second valve rod 162 is located outside the pressure boundary 49 which is pressure-separated from the steam flow path 52. In the steam valve 14 of the second embodiment, the first valve body 171 is fixed to the first valve rod 161, so that no wear occurs between the first valve body 171 and the first valve rod 161, and since the axial division position Pz of the first valve rod 161 and the second valve rod 162 is located outside the pressure boundary 49, the division position Pz is not exposed to the steam flow path 52 through which high-pressure steam may flow at high speed, so that wear at the division position Pz is effectively suppressed.

[0074] In the steam valve 14 according to the second embodiment, the pressure boundary 49 is formed by the first inclined surface 619 and the first contact surface 471. This allows the pressure boundary 49 to be formed by utilizing a configuration for limiting the range of movement of the valve stem 60 towards the tip side, thereby simplifying the configuration of the steam valve 14.

[0075] In the steam valve 14 according to the second embodiment, the first contact surface 471 is formed on a second guide member 47B which is a cylindrical support member that supports the valve rod 60 so that it can slide freely. This allows the pressure boundary 49 to be formed by the second guide member 47B, which is a support member for the valve rod, and the valve rod 60 (first valve rod 161).

[0076] In the steam valve 14 according to the second embodiment, the first valve stem 161 has a first valve-opening pressing surface 616 , and the second valve stem 162 has a second valve-opening pressing surface 626 . As a result, even if the valve rod 60 is divided into the first valve rod 161 and the second valve rod 162, the first valve rod 161 can be moved from the base end side of the valve rod 60 towards the tip end side by the second valve rod 162.

[0077] In the steam valve 14 of the second embodiment, when the stop valve 45 is fully open, the first valve rod 161 is clamped between the first abutment surface 471 of the second guide member 47B and the second open valve pressing surface 626 of the second valve rod 162 and fixed to the second guide member 47B. As a result, when the stop valve 45 is fully open, the first valve rod 161 and the first valve body 171 fixed to the first valve rod 161 are fixed to the second guide member 47B, thereby suppressing vibration of the first valve rod 161 and the first valve body 171. In addition, since the first valve rod 161 is fixed to the second guide member 47B, wear at the contact portion between the first valve rod 161 and the second guide member 47B can be effectively suppressed.

[0078] In the steam valve 14 according to the second embodiment, the stop valve 45 has a second valve body 172 fixed to a tip portion 162a of a second valve rod 162. The first valve body 171 functions as a valve seat for the second valve body 172, and has a first valve body through hole 75 formed therein through which steam flows when the second valve body 172 is opened. As a result, by opening the second valve body 172, the steam acting on the stop valve 45 can be released to the outside via the first valve body through-hole 75, thereby reducing the pressure of the steam acting on the stop valve 45. In other words, the pressure difference between the upstream and downstream sides of the first valve body 171 is reduced, making it easier to open the first valve body 71. Furthermore, in the steam valve 14 according to the second embodiment, the second valve rod 162 and the second valve body 172 are fixed, so that no wear occurs between the second valve body 172 and the second valve rod 162.

[0079] In the steam valve 14 of the second embodiment, a first valve body through hole 75 is formed in the first valve body 171, so that the pressure difference between the upstream and downstream sides of the first valve body 171 can be effectively reduced even if the amount of steam leaking from the gap between the regulating valve 43 and the valve seat 48 is relatively large.

[0080] In the steam valve 14 of the second embodiment, when the second valve rod 162 moves from the tip side to the base end side of the valve rod 60, the first valve body 171 is configured to be pressed from the tip side to the base end side of the valve rod 60 by the second valve body 172, and to move from the tip side to the base end side of the valve rod 60 together with the first valve rod 161. As a result, the first valve body 171 and the first valve rod 161 are able to move from the tip side to the base end side of the valve rod 60 by the second valve body 172. Furthermore, in the steam valve 14 of the second embodiment, when the stop valve 45 is fully closed, the first valve body 171 is clamped and fixed between the valve seat 48 of the valve body 41 and the second valve body 172, thereby effectively preventing steam leakage from between the first valve body 171 and the valve seat 48 of the valve body 41.

[0081] In the steam valve 14 of the second embodiment, the length by which the first valve rod 161 and the small diameter portion 162S of the second valve rod 162 overlap in the axial direction Z has a relatively wide range of options from a functional point of view, and therefore it is easy to optimize the length from the standpoints of the wear soundness of the stop valve 45, the vibration soundness of the stop valve 45, and the drive soundness of the stop valve 45. The position in the axial direction Z where the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are provided does not necessarily have to be near a system for recovering leaked steam, such as the high-pressure stem leak system 81. For example, as long as the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are configured so that steam does not leak from between the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 to the outside of the steam valve 14, the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 may be located in the atmosphere opening portion. In other words, as long as the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 are configured so that steam does not leak from between the first valve-opening pressing surface 616 and the second valve-opening pressing surface 626 to the outside of the steam valve 14, the overlap length of the first valve rod 161 and the small diameter portion 162S of the second valve rod 162 in the axial direction Z may be any length.

[0082] In the steam valve 14 according to the second embodiment, a pressure boundary 49 is formed by the first inclined surface 619 and the first abutment surface 471. Therefore, the gap between the inner diameter of the valve stem insertion hole 614 of the first valve stem 161 and the outer diameter of the small diameter portion 162S of the second valve stem 162 can be made relatively large, making it easier to maintain drive soundness, such as suppressing stick-slip.

[0083] The steam valve 14 in some of the embodiments described above has a control valve 43 arranged opposite the stop valve 45 in the axial direction Z and capable of abutting against the valve seat 48 at a position outer than the position of the valve seat 48 where the first valve body 71, 171 abuts. This makes it possible to effectively suppress wear of the steam valve 14 in which the regulator valve 43 is disposed outside the stop valve 45 .

[0084] The power generation system 1 according to one embodiment includes the steam valve 14 according to some of the above-described embodiments, a boiler 11 that generates steam, a steam turbine 10 driven by the steam, and a steam supply pipe (first steam supply pipe 12) that connects the boiler 11 and the steam turbine 10 and supplies steam to the steam turbine 10. The steam valve 14 according to some of the embodiments is provided in the steam supply pipe (first steam supply pipe 12). As a result, by providing the power generation system 1 with the steam valve 14 that can suppress wear on the stop valve 45, it is possible to reduce the frequency of maintenance of the steam valve 14, thereby improving the operating efficiency of the power generation system 1.

[0085] The present disclosure is not limited to the above-described embodiments, and includes modifications to the above-described embodiments and appropriate combinations of these modifications. For example, in some of the embodiments described above, the second guide member 47B does not have to protrude into the steam flow passage 52. In addition, in some of the embodiments described above, the first abutment surface 471 that abuts against the first inclined surface 619 of the first valve rod 61, 161 when the stop valve 45 is fully open may be provided on a member other than the second guide member 47B, such as the flow path partition 47 (valve casing) or a through bush attached to the flow path partition 47.

[0086] The contents described in each of the above embodiments can be understood, for example, as follows. (1) A steam valve 14 according to at least one embodiment of the present disclosure includes a steam flow path 52 through which steam flows, a valve body 41 having a valve seat 48 provided midway through the steam flow path 52 and having an opening, a valve rod 60 extending in an axial direction Z along which axes O1 and O2 extend and movable forward and backward in the axial direction Z, and a stop valve 45 having a first valve body 71, 171 fixed to a tip end 60A of the valve rod 60 and abutting against the valve seat 48 to close the steam flow path 52. The valve rod 60 is divided into two parts, a first valve rod 61, 161 to which the first valve body 71, 171 is fixed, and a second valve rod 62, 162 different from the first valve rod 61, 161. A division position Pz in the axial direction Z between the first valve rod 61, 161 and the second valve rod 62, 162 is located outside a pressure boundary 49 that is pressure-separated from the steam flow path 52.

[0087] According to the above configuration (1), the first valve body 71, 171 is fixed to the first valve rod 61, 161, so that no wear occurs between the first valve body 71, 171 and the first valve rod 61, 161, and the division position Pz in the axial direction Z of the first valve rod 61, 161 and the second valve rod 62, 162 is located outside the pressure boundary 49. Therefore, the division position Pz is not exposed to the steam flow path 52, through which high-pressure steam may flow at high speed, and wear at the division position Pz is effectively suppressed.

[0088] (2) In some embodiments, in the configuration of (1) above, the valve rod 60 may have a first inclined surface 619 that increases the outer diameter of the valve rod 60 from the tip side toward the base end side. The steam valve 14 according to at least one embodiment of the present disclosure may include a mating member (second guide member 47B) having a first abutment surface 471 that abuts against the first inclined surface 619 when the stop valve 45 is fully open. The pressure boundary 49 may be formed by the first inclined surface 619 and the first abutment surface 471.

[0089] According to the above configuration (2), the pressure boundary 49 can be formed by utilizing the configuration for limiting the range of movement of the valve stem 60 toward the tip side, so that the configuration of the steam valve 14 can be simplified.

[0090] (3) In some embodiments, in the configuration of (2) above, the mating member (second guide member 47B) may be a cylindrical support member (second guide member 47B) that supports the valve rod 60 so that it can slide freely.

[0091] According to the above configuration (3), the pressure boundary 49 can be formed by the support member for the valve rod 60 (the second guide member 47B) and the valve rod 60.

[0092] (4) In some embodiments, in the configuration of (2) or (3) above, the first valve stem 61, 161 may have a first valve-opening pressing surface 613, 616 that is pressed in the axial direction Z by the second valve stem 62, 162 when the second valve stem 62, 162 moves from the base end side toward the tip end side of the valve stem 60. The second valve stem 62, 162 may have a second valve-opening pressing surface 623, 626 that presses the first valve-opening pressing surface 613, 616 in the axial direction when the second valve stem 62, 162 moves from the base end side toward the tip end side of the valve stem 60.

[0093] According to the above configuration (4), even if the valve rod 60 is divided into the first valve rod 61, 161 and the second valve rod 62, 162, the first valve rod 61, 161 can be moved from the base end side of the valve rod 60 toward the tip end side by the second valve rod 62, 162.

[0094] (5) In some embodiments, in the configuration of (4) above, the first valve rod 61, 161 may be clamped between the first abutment surface 471 and the second open-valve pressing surfaces 623, 626 when the stop valve 45 is fully open, and fixed to the opposing member (the second guide member 47B).

[0095] According to the configuration (5) above, since the first valve rod 61, 161 and the first valve body 71, 171 fixed to the first valve rod 61, 161 are fixed to the mating member (second guide member 47B) when the stop valve 45 is fully open, it is possible to suppress vibration of the first valve rod 61, 161 and the first valve body 71, 171. Furthermore, since the first valve rod 61, 161 is fixed to the mating member (second guide member 47B), it is possible to effectively suppress wear at the contact portion between the first valve rod 61, 161 and the mating member (second guide member 47B).

[0096] (6) In some embodiments, in the configuration of (4) or (5) above, the first valve rod 61 may have a through hole 617 penetrating from the tip to the base end of the first valve rod 61. When the stop valve 45 is fully open, the first valve-open pressing surface 613 and the second valve-open pressing surface 623 may come into contact with each other, thereby preventing steam in the steam flow passage 52 from flowing out to the outside via the through hole 617.

[0097] According to the above configuration (6), by configuring so that steam in the through hole 617 can be released to the outside when the stop valve 45 starts to open from a fully closed state, it is possible to release the steam acting on the stop valve 45 to the outside via the through hole 617, thereby reducing the steam pressure acting on the stop valve 45. Furthermore, according to the above configuration (6), it is possible to prohibit the steam from leaking to the outside via the through hole 617 when the stop valve 45 is fully open.

[0098] (7) In some embodiments, in any of the configurations (4) to (6) above, the first valve rod 61 may have a first closing-time pressing surface 615 that is pressed in the axial direction Z by the second valve rod 62 when the stop valve 45 is fully closed. The second valve rod 62 may have a second closing-time pressing surface 625 that presses the first closing-time pressing surface 615 in the axial direction when the stop valve 45 is fully closed.

[0099] According to the above configuration (7), even if the valve rod 60 is divided into the first valve rod 61 and the second valve rod 62, the first valve rod 61 can be moved from the tip side to the base end side of the valve rod 60 by the second valve rod 62.

[0100] (8) In some embodiments, in the configuration of (7) above, the first valve rod 61 may have a through hole 617 penetrating from the tip to the base end of the first valve rod 61. When the stop valve 45 is fully closed, the first valve-closing-time pressing surface 615 and the second valve-closing-time pressing surface 625 may come into contact with each other, thereby preventing steam in the steam flow passage 52 from flowing out to the outside via the through hole 617.

[0101] According to the above configuration (8), by configuring so that the steam in the through hole 617 can be released to the outside when the stop valve 45 starts to open from a fully closed state, it is possible to release the steam acting on the stop valve 45 to the outside via the through hole 617 and reduce the steam pressure acting on the stop valve 45. Furthermore, according to the above configuration (8), it is possible to prohibit the outflow of steam to the outside via the through hole 617 when the stop valve 45 is fully closed.

[0102] (9) In some embodiments, in the configuration of (8) above, when the stop valve 45 is fully open, the first open-state pressing surface 613 and the second open-state pressing surface 623 may come into contact with each other to prohibit steam in the steam flow path 52 from flowing out to the outside via the through-hole 617. When the stop valve 45 begins to open from a fully closed state, the first closed-state pressing surface 615 and the second closed-state pressing surface 625 may move away from each other, and the first open-state pressing surface 613 and the second open-state pressing surface 623 may move away from each other to allow steam in the steam flow path 52 to flow out to the outside via the through-hole 617.

[0103] According to the above configuration (9), when the stop valve 45 starts to open from a fully closed state, the steam acting on the stop valve 45 is released to the outside via the through hole 617, thereby reducing the pressure of the steam acting on the stop valve 45. Furthermore, according to the above configuration (9), when the stop valve 45 is fully open, the outflow of steam to the outside via the through hole 617 can be prevented.

[0104] (10) In some embodiments, in any of the configurations (1) to (5) above, the first valve rod 161 may have a valve rod insertion hole 614 that penetrates the first valve rod 161 from the base end to the tip, and through which the second valve rod 162 (small diameter portion 162S) is inserted. The second valve rod 162 (small diameter portion 162S) may be inserted through the valve rod insertion hole 614. The stop valve 45 may have a second valve body 172 fixed to the tip portion 162a of the second valve rod 162. The first valve body 171 may function as a valve seat for the second valve body 172, and may have a first valve body through hole 75 formed therein through which steam flows when the second valve body 172 is opened.

[0105] According to the above configuration (10), by opening the second valve body 172, the steam acting on the stop valve 45 can be released to the outside via the first valve body through-hole 75, thereby reducing the steam pressure acting on the stop valve 45. Furthermore, according to the above configuration (10), since the second valve rod 162 and the second valve body 172 are fixed, no wear occurs between the second valve body 172 and the second valve rod 162.

[0106] (11) In some embodiments, in the configuration of (10) above, when the second valve rod 162 moves from the tip side to the base end side of the valve rod 60, the first valve body 171 is configured to be pressed from the tip side to the base end side of the valve rod 60 by the second valve body 172, and to move from the tip side to the base end side of the valve rod 60 together with the first valve rod 161.

[0107] According to the above configuration (11), the first valve body 171 and the first valve rod 161 can be moved from the tip end side to the base end side of the valve rod 60 by the second valve body 172. Furthermore, according to the above configuration (11), when the stop valve 45 is fully closed, the first valve body 171 is sandwiched and fixed between the valve seat 48 of the valve body 41 and the second valve body 172, so that leakage of steam from between the first valve body 171 and the valve seat 48 of the valve body 41 can be effectively prevented.

[0108] (12) In some embodiments, in any of the configurations (1) to (11) above, it is preferable to have a regulating valve 43 that is arranged opposite the stop valve 45 in the axial direction Z and can abut against the valve seat 48 at a position outside the position of the valve seat 48 where the first valve body 71, 171 abuts.

[0109] According to the above configuration (12), in the steam valve 14 in which the regulator valve 43 is disposed outside the stop valve 45, wear of the steam valve 14 can be effectively suppressed.

[0110] (13) A power generation system 1 according to at least one embodiment of the present disclosure includes a steam valve 14 having any of the configurations (1) to (12) above, a boiler 11 that generates steam, a steam turbine 10 driven by the steam, and a steam supply pipe (first steam supply pipe 12) that connects the boiler 11 and the steam turbine 10 and supplies steam to the steam turbine 10. The steam valve 14 is provided in the steam supply pipe (first steam supply pipe 12).

[0111] According to the above configuration (13), the power generation system 1 is provided with a steam valve 14 that can suppress wear of the stop valve 45, thereby making it possible to reduce the frequency of maintenance of the steam valve 14, thereby improving the operating efficiency of the power generation system 1. [Explanation of symbols]

[0112] 1. Power generation system 10. Steam Turbine 11 Boiler 12 First steam supply pipe 14 Steam valve 41 Valve body 43 Regulating valve 45 Stop valve 47A First guide member 47B Second guide member 48 Valve seat 52 Steam flow path 60 Valve stem 61,161 First valve stem 62,162 Second valve stem 71,171 First valve body 75 First valve body through hole 172 Second valve body 471 1st contact surface 610a Tip 610b proximal end 613,616 First opening pressure surface 614 Valve stem insertion hole 615 First closing valve pressing surface 617 Through hole 619 1st slope 623,626 Second valve opening pressure surface 625 Second closing valve pressing surface

Claims

1. a valve body including a steam flow passage through which steam flows and a valve seat provided midway along the steam flow passage and having an opening; a stop valve including a valve rod extending in an axial direction along which an axis extends and movable forward and backward in the axial direction, and a first valve body fixed to a tip end of the valve rod and abutting against the valve seat when the valve rod moves from a tip end side toward a base end side of the valve rod to close the steam flow path; Equipped with The valve rod has a first inclined surface that increases an outer diameter of the valve rod from the tip side toward the base end side of the valve rod, a mating member having a first contact surface that contacts the first inclined surface when the stop valve is fully open, the mating member being immovable with respect to a flow path partition portion that partitions the steam flow path, a pressure boundary formed by the first inclined surface and the first contact surface contacting each other, the pressure boundary separating the steam flow path from an outside of the steam flow path in terms of pressure; The valve rod is divided into a first valve rod to which the first valve body is fixed and a second valve rod different from the first valve rod, The first valve rod has a through hole that penetrates from the tip end to the base end of the first valve rod, A surface where the first valve rod and the second valve rod contact each other when the valve is opened and is inclined with respect to the axis, or a surface where the first valve rod and the second valve rod contact each other when the valve is closed and is inclined with respect to the axis is located outside the pressure boundary. Steam valve.

2. The mating member is a cylindrical support member that slidably supports the valve stem. The steam valve of claim 1 .

3. The first valve rod has a first valve-opening pressing surface that is pressed in the axial direction by the second valve rod when the second valve rod moves from the base end side to the tip end side of the valve rod, The second valve rod has a second valve-opening pressing surface that presses the first valve-opening pressing surface in the axial direction when the second valve rod moves from the base end side to the tip end side of the valve rod. A steam valve according to claim 1 or 2.

4. The first valve rod is clamped between the first abutment surface and the second valve-opening pressing surface when the stop valve is fully opened and fixed to the mating member. The steam valve of claim 3 .

5. The first valve rod has a through hole penetrating from the tip end to the base end of the first valve rod, having When the stop valve is fully opened, the first valve-opening pressing surface and the second valve-opening pressing surface come into contact with each other to inhibit the steam in the steam flow path from flowing out to the outside through the through hole. The steam valve of claim 3.

6. The first valve rod has a first valve closing pressing surface that is pressed in the axial direction by the second valve rod when the stop valve is fully closed, The second valve rod has a second valve closing pressing surface that presses the first valve closing pressing surface in the axial direction when the stop valve is fully closed. The steam valve of claim 3.

7. The first valve rod has a through hole penetrating from the tip end to the base end of the first valve rod, having When the stop valve is fully closed, the first valve-closing pressing surface and the second valve-closing pressing surface come into contact with each other, thereby preventing the steam in the steam flow path from flowing out to the outside through the through hole. The steam valve of claim 6.

8. When the stop valve is fully opened, the first valve-opening pressing surface and the second valve-opening pressing surface come into contact with each other, thereby preventing the steam in the steam flow path from flowing out to the outside through the through hole, when the stop valve begins to open from a fully closed state, the first closing-state pressing surface and the second closing-state pressing surface are separated from each other, and the first opening-state pressing surface and the second opening-state pressing surface are separated from each other, thereby allowing the steam in the steam flow path to flow out through the through hole. The steam valve of claim 7.

9. a valve body including a steam flow passage through which steam flows and a valve seat provided midway along the steam flow passage and having an opening; a stop valve including a valve rod extending in an axial direction along which an axis extends and movable forward and backward in the axial direction, and a first valve body fixed to a tip end of the valve rod and abutting against the valve seat when the valve rod moves from a tip end side toward a base end side of the valve rod to close the steam flow path; Equipped with The valve rod has a first inclined surface that increases an outer diameter of the valve rod from the tip side toward the base end side of the valve rod, a mating member having a first contact surface that contacts the first inclined surface when the stop valve is fully open, the mating member being immovable with respect to a flow path partition portion that partitions the steam flow path, a pressure boundary formed by the first inclined surface and the first contact surface contacting each other, the pressure boundary separating the steam flow path from an outside of the steam flow path in terms of pressure; The valve rod is divided into a first valve rod to which the first valve body is fixed and a second valve rod different from the first valve rod, A surface where the first valve rod and the second valve rod contact each other when the valve is open and is inclined with respect to the axis is located outside the pressure boundary, The first valve rod has a valve rod insertion hole that penetrates the first valve rod from a base end to a tip end and through which the second valve rod is inserted, The second valve stem is inserted into the valve stem insertion hole, The stop valve has a second valve body fixed to a tip portion of the second valve rod, The first valve body functions as a valve seat for the second valve body, and has a first valve body through hole through which the steam flows when the second valve body is opened. Steam valve.

10. When the second valve rod moves from the tip side to the base end side of the valve rod, the first valve body is pressed from the tip side to the base end side of the valve rod by the second valve body and moves from the tip side to the base end side of the valve rod together with the first valve rod. The steam valve of claim 9.

11. a valve body including a steam flow passage through which steam flows and a valve seat provided midway along the steam flow passage and having an opening; a stop valve including a valve stem extending in an axial direction along which an axis extends and capable of moving forward and backward in the axial direction, and a first valve body fixed to a tip portion of the valve stem and abutting against the valve seat to close the steam flow path; Equipped with The valve rod has a first inclined surface that increases the outer diameter of the valve rod from the tip end side toward the base end side of the valve rod, a mating member having a first abutment surface that abuts against the first inclined surface when the stop valve is fully open, a pressure boundary formed by the first inclined surface and the first contact surface contacting each other, the pressure boundary separating the steam flow path from an outside of the steam flow path in terms of pressure; The valve rod is divided into a first valve rod to which the first valve body is fixed and a second valve rod different from the first valve rod, A surface where the first valve rod and the second valve rod contact each other when the valve is opened and is inclined with respect to the axis, or a surface where the first valve rod and the second valve rod contact each other when the valve is closed and is inclined with respect to the axis is located outside the pressure boundary, The surface where the first valve rod and the second valve rod contact each other when the valve is opened and is inclined with respect to the axis line is a first valve-opening pressing surface that is provided in the first valve rod and is pressed in the axial direction by the second valve rod when the second valve rod moves from the base end side to the tip end side of the valve rod; a second valve-opening pressing surface that is provided on the second valve rod and presses the first valve-opening pressing surface in the axial direction when the second valve rod moves from the base end side to the tip end side of the valve rod; Including, The first valve rod has a through hole penetrating from the tip end to the base end of the first valve rod, having When the stop valve is fully opened, the first valve-opening pressing surface and the second valve-opening pressing surface come into contact with each other to inhibit the steam in the steam flow path from flowing out to the outside through the through hole. Steam valve.

12. a valve body including a steam flow passage through which steam flows and a valve seat provided midway along the steam flow passage and having an opening; a stop valve including a valve stem extending in an axial direction along which an axis extends and capable of moving forward and backward in the axial direction, and a first valve body fixed to a tip portion of the valve stem and abutting against the valve seat to close the steam flow path; Equipped with The valve rod has a first inclined surface that increases the outer diameter of the valve rod from the tip end side toward the base end side of the valve rod, a mating member having a first abutment surface that abuts against the first inclined surface when the stop valve is fully open, a pressure boundary formed by the first inclined surface and the first contact surface contacting each other, the pressure boundary separating the steam flow path from an outside of the steam flow path in terms of pressure; The valve rod is divided into a first valve rod to which the first valve body is fixed and a second valve rod different from the first valve rod, A surface where the first valve rod and the second valve rod contact each other when the valve is opened and is inclined with respect to the axis, or a surface where the first valve rod and the second valve rod contact each other when the valve is closed and is inclined with respect to the axis is located outside the pressure boundary, The surface where the first valve rod and the second valve rod contact each other when the valve is opened and is inclined with respect to the axis line is a first valve-opening pressing surface that is provided in the first valve rod and is pressed in the axial direction by the second valve rod when the second valve rod moves from the base end side to the tip end side of the valve rod; a second valve-opening pressing surface that is provided on the second valve rod and presses the first valve-opening pressing surface in the axial direction when the second valve rod moves from the base end side to the tip end side of the valve rod; Including, The surface where the first valve rod and the second valve rod contact each other when the valve is closed and is inclined with respect to the axis line is a first valve closing pressing surface that is provided on the first valve rod and is pressed in the axial direction by the second valve rod when the stop valve is fully closed; A second valve closing pressing surface that is provided on the second valve rod and presses the first valve closing pressing surface in the axial direction when the stop valve is fully closed; Including, The first valve rod has a through hole penetrating from the tip end to the base end of the first valve rod, having When the stop valve is fully closed, the first valve-closing pressing surface and the second valve-closing pressing surface come into contact with each other to inhibit the steam in the steam flow path from flowing out to the outside through the through hole. Steam valve.

13. When the stop valve is fully opened, the first valve-opening pressing surface and the second valve-opening pressing surface come into contact with each other, thereby preventing the steam in the steam flow path from flowing out to the outside through the through hole, when the stop valve begins to open from a fully closed state, the first closing-state pressing surface and the second closing-state pressing surface are separated from each other, and the first opening-state pressing surface and the second opening-state pressing surface are separated from each other, thereby allowing the steam in the steam flow path to flow out through the through hole. The steam valve of claim 12.

14. a regulator valve disposed opposite the stop valve in the axial direction and capable of contacting the valve seat at a position outside the valve seat at which the first valve body contacts; A steam valve according to any one of claims 1, 2, 9, 10 to 13.

15. A steam valve according to any one of claims 1, 2, 9, 10 to 13; A boiler for generating steam; a steam turbine driven by the steam; a steam supply pipe connecting the boiler and the steam turbine and supplying the steam to the steam turbine; Equipped with The steam valve is provided in the steam supply pipe.

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