Steam turbine blade, steam turbine, and method for manufacturing steam turbine blade

Abstract

A steam turbine blade according to at least one embodiment of the present disclosure comprises: a recess part formed in the surface of the blade; a liquid-phase guiding member that is inserted in and fixed to the recess part, and that either has a hydrophilic coating provided thereon or has, on the surface thereof, projections and recesses for guiding liquid-phase water to the rear edge side of the blade; and a through-hole for taking, into an internal space of the blade, the liquid-phase water guided by the liquid-phase guiding member.

Description

[Technical Field]

[0001] The present disclosure relates to a steam turbine blade, a steam turbine, and a method for manufacturing a steam turbine blade. This application claims priority based on Japanese Patent Application No. 2022-181285, filed with the Japan Patent Office on November 11, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Steam passing through a steam turbine loses energy as it travels from upstream to downstream, resulting in a drop in temperature and pressure. As a result, in the downstream stages of the steam turbine, some of the steam condenses into tiny water droplets that exist in the airflow. Some of these droplets adhere to the surface of the turbine stator blades and quickly grow on the blade surface to form a liquid film. As this liquid film grows further and thickens, some of it is torn off by the steam flow and scattered as coarse droplets. When these scattered droplets collide with the turbine rotor blades, their rotation is hindered, which can cause braking loss or erosion.

[0003] For this reason, for example, a minute slit is formed in the blade surface of a hollow stator vane, connecting the internal space inside the stator vane with the outside of the stator vane, and moisture (liquid phase) adhering to the surface of the stator vane is sucked into the internal space through this slit by a pressure difference, thereby suppressing the scattering of droplets (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-181773 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, droplets are generated in relatively downstream stages of a steam turbine. In relatively downstream stages of a steam turbine, the size of the turbine blades is relatively large. Therefore, forming fine slits in relatively large turbine blades is difficult to process, and there are concerns about increased costs.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to efficiently remove liquid water adhering to the surface of a blade while suppressing an increase in cost. [Means for solving the problem]

[0007] (1) A steam turbine blade according to at least one embodiment of the present disclosure includes: a recess formed on the surface of the wing; a liquid guide member that is inserted into and fixed to the recess, and has a surface on which irregularities for guiding liquid water to the trailing edge side of the blade are formed or on which a hydrophilic coating is applied; a through hole for taking the liquid-phase water guided by the liquid-phase guide member into the internal space of the blade; Equipped with.

[0008] (2) A steam turbine according to at least one embodiment of the present disclosure includes: The steam turbine blade has the configuration described in (1) above.

[0009] (3) A method for manufacturing a steam turbine blade according to at least one embodiment of the present disclosure includes: A method for manufacturing a steam turbine blade, comprising: forming a recess in a surface of the airfoil; forming a through hole communicating with an internal space of the blade at a position closer to the trailing edge of the blade than the recess; a step of inserting and fixing a liquid phase guide member, the liquid phase guide member having a surface formed with irregularities for guiding liquid phase water to the trailing edge side of the blade or having a hydrophilic coating, into the recess; Equipped with. [Effects of the Invention]

[0010] According to at least one embodiment of the present disclosure, liquid adhering to the surface of the wing can be efficiently removed while suppressing increases in cost. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view of a steam turbine according to an embodiment of the present invention, taken along an axial direction; [Figure 2A] FIG. 2 is a schematic diagram showing the blade surface on the pressure side of the airfoil portion of a stator vane in a downstream stage among multiple stages of stator vanes. [Figure 2B] FIG. 2 is a schematic diagram showing the blade surface on the pressure side of the airfoil portion of a stator vane in a downstream stage among multiple stages of stator vanes. [Figure 3A] FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. [Figure 3B] FIG. 2B is a cross-sectional view taken along the arrow BB in FIG. 2A. [Figure 3C] FIG. 2B is a cross-sectional view taken along the arrow CC in FIG. 2A. [Figure 4] FIG. 3D is an exploded view of FIG. 3C. [Figure 5A] FIG. 5 is a view corresponding to FIG. 4, showing a case where a liquid phase guide member according to another embodiment is used. [Figure 5B] FIG. 5 is a view corresponding to FIG. 4, showing a case where a liquid phase guide member according to still another embodiment is used. [Figure 6A] FIG. 2 is a schematic diagram illustrating an example of a liquid phase guide member. [Figure 6B] FIG. 10 is a schematic diagram showing another example of a liquid phase guide member. [Figure 6C] FIG. 6C is an exploded cross-sectional view taken along the arrow DD in FIG. 6B. [Figure 7] FIG. 10 is a schematic diagram showing yet another example of a liquid phase guide member. [Figure 8] FIG. 10 is a schematic diagram showing yet another example of a liquid phase guide member. [Figure 9] FIG. 10 is a schematic diagram showing yet another example of a liquid phase guide member. [Figure 10] 1 is a flowchart illustrating steps in a method for manufacturing a vane according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several 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 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 arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, 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 such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state 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 representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0013] First, the overall configuration of a steam turbine according to some embodiments will be described. Fig. 1 is a schematic cross-sectional view along the axial direction of a steam turbine according to an embodiment of the present disclosure. As shown in Fig. 1, the steam turbine 1 includes a rotor 2 supported by bearings 6 for rotation about a central axis O, multiple stages of moving blades 8 attached to the rotor 2, an inner casing 10 that houses the rotor 2 and the moving blades 8, and multiple stages of stator blades 9 attached to the inner casing 10 so as to face the moving blades 8. An outer casing 12 is provided outside the inner casing 10. In this steam turbine 1, when steam is introduced into the inner casing 10 from a steam inlet 3, the steam expands and accelerates as it passes through the stator blades 9, and performs work on the moving blades 8 to rotate the rotor 2.

[0014] The steam turbine 1 also includes an exhaust chamber 14. As shown in FIG. 1 , the exhaust chamber 14 is located downstream of the rotor blades 8 and the stator blades 9. Steam (steam flow Fs) that has passed through the rotor blades 8 and the stator blades 9 in the inner casing 10 flows into the exhaust chamber 14 from an exhaust chamber inlet 11, passes through the inside of the exhaust chamber 14, and is discharged to the outside of the steam turbine 1 from an exhaust chamber outlet 13 provided on the lower side of the exhaust chamber 14. In some embodiments, a condenser (not shown) is provided below the exhaust chamber 14. In this case, the steam that has finished working on the rotor blades 8 in the steam turbine 1 flows from the exhaust chamber 14 to the condenser via the exhaust chamber outlet 13.

[0015] FIG. 2A is a schematic diagram showing a blade surface 22a of the pressure side 22 of the airfoil portion 21 of a stator vane 9 at a downstream stage among multiple stages of stator vanes 9, and shows an example of the arrangement of a liquid phase guide member 30 according to an embodiment described later. FIG. 2B is a schematic diagram showing the blade surface 22a of the pressure side 22 of the airfoil portion 21 of the stator vane 9 at the downstream stage among the multiple stages of stator vanes 9, and shows another example of the arrangement of the liquid phase guide member 30 according to an embodiment described later. FIG. 3A is a cross-sectional view taken along the line AA in FIG. 2A. FIG. 3B is a cross-sectional view taken along the arrow BB in FIG. 2A. FIG. 3C is a cross-sectional view taken along the line CC in FIG. 2A. FIG. 4 is a view equivalent to the exploded view of FIG. 3C. FIG. 5A is a view corresponding to FIG. 4, and shows a case where a liquid phase guide member 30 according to another embodiment is used. FIG. 5B is a view corresponding to FIG. 4, and shows a case where a liquid phase guide member 30 according to still another embodiment is used.

[0016] In the following description, unless otherwise specified, the stator blade 9 refers to the stator blade 9 in the downstream stage among the stator blades 9 in multiple stages. The stator vane 9 in some embodiments comprises a recess 23 formed on the surface of the blade (airfoil portion 21), a liquid phase guide member 30 inserted and fixed into the recess 23 for guiding liquid phase water toward the trailing edge 21T of the blade, a through hole 27 for taking in the liquid phase water guided by the liquid phase guide member 30 into the internal space 25 of the airfoil portion 21, and a guide groove 28. The airfoil portion 21 of the stator vane 9 according to some embodiments has a hollow structure. The stator vane 9 according to some embodiments is configured to be able to discharge liquid-phase water taken into the internal space 25 to the outside of the airfoil portion 21 as will be described later.

[0017] (recess 23) In the stator vane 9 according to some embodiments, the recess 23 is a recess formed in the blade surface 22a of the pressure side 22 for attaching the liquid phase guide member 30. The depth of the recess 23 is preferably set so that a protrusion 31 (described later) of the liquid phase guide member 30 attached to the recess 23 has the same height in the blade thickness direction as the blade surface 22a around the recess 23 of the airfoil portion 21, i.e., so that the protrusion 31 of the liquid phase guide member 30 does not protrude from the blade surface 22a around the recess 23 of the airfoil portion 21.

[0018] (Overview of the liquid phase guide member 30) In the stator blade 9 according to some embodiments, the liquid phase guide member 30 is a member for efficiently guiding liquid phase water on the surface of the liquid phase guide member 30 to the through holes 27 described later. In the examples shown in FIGS. 2A, 2B, 3C, and 4, the liquid phase guide member 30 is formed with a plurality of grooves 33 extending from the leading edge 21L of the airfoil portion 21 toward the trailing edge 21T. In the example shown in FIG. 5A, the liquid phase guide member 30 is a member having fine irregularities formed on the surface 30a to provide hydrophilicity. In the example shown in FIG. 5B, the liquid phase guiding member 30 is a member having a hydrophilic coating applied to the surface 30a to make it hydrophilic. The liquid phase guide member 30 will be described in detail later.

[0019] In the stator blade 9 according to some embodiments, the liquid phase guide member 30 is fixed to the recess 23 by welding or using an adhesive.

[0020] (Through hole 27 and guide groove 28) As shown in Figures 2A, 2B, and 3B, the stator vane 9 according to some embodiments has a plurality of through holes 27 formed therein for taking in liquid-phase water guided by the liquid-phase guide member 30 into the internal space 25 of the airfoil portion 21. In the stator vane 9 according to some embodiments, the through holes 27 are holes that penetrate the blade wall 24 on the pressure side 22 of the airfoil portion 21, and are arranged at intervals in the blade height direction at positions relatively close to the trailing edge 21T of the airfoil portion 21. The through holes 27 are relatively fine holes. Therefore, in order to efficiently guide the liquid water guided by the liquid-phase guide member 30 to these relatively fine through holes 27, guide grooves 28 are formed in the blade wall 24 on the pressure side 22 of the airfoil portion 21 so as to trace the through holes 27 arranged at intervals in the blade height direction. The plurality of through holes 27 are provided so as to open to the bottom 28a of the guide groove 28.

[0021] (Advantages of providing the liquid phase guide member 30) In the stator vane 9 according to some embodiments, liquid water that has adhered to the blade surface 22a on the pressure side 22 of the airfoil portion 21 within the range R for collecting liquid water flows along the direction of arrow a in Figures 2A and 2B under the influence of the steam flow Fs. Then, the liquid water is guided to the through hole 27 by the liquid phase guide member 30 and the guide groove 28 provided within the range R, and is taken into the internal space 25.

[0022] For example, in a conventional stator vane 9 that does not have a liquid-phase guide member 30, in addition to the guide groove 28 of FIG. 2A, for example, by forming a guide groove 28 shown by a two-dot chain line in FIG. 2A, a relatively long guide groove 28 corresponding to the above-mentioned range R needs to be formed, and more through holes 27 need to be provided. However, the vanes 9 in the downstream stages are relatively large in size, and therefore, forming minute through holes 27 and guide grooves 28 in the relatively large vanes 9 is difficult to process, raising concerns about increased costs.

[0023] In this regard, according to the stator vane 9 according to some embodiments, liquid water can be guided to the through holes by the liquid guide member 30, so that the area where the through holes 27 are provided can be narrowed, the number of the through holes 27 can be reduced, and the length of the guide groove 28 can be shortened. This makes it possible to efficiently remove liquid water adhering to the surface of the airfoil portion 21 while suppressing the cost of providing the through holes 27 and the guide groove 28 in the relatively large stator vane 9.

[0024] In a steam turbine 1 equipped with a stator vane 9 according to some embodiments, the cost of providing a through hole 27 in a relatively large stator vane 9 can be reduced while efficiently removing liquid water adhering to the surfaces of the stator vane 9 and the liquid phase guide member 30.

[0025] (Details of the liquid phase guide member 30) 2A, 2B, 3C, and 4, the liquid phase guide member 30A (30) may be formed by bending a plate-like member so as to form a plurality of grooves 33 extending from the leading edge 21L to the trailing edge 21T. For example, by pressing a plate-like member, the liquid phase guide member 30A having such a shape can be obtained as a press-molded product. This makes it possible to reduce the manufacturing cost of the liquid phase guide member. The liquid phase guide member 30A formed in this manner has a plurality of grooves 33 and protrusions 31 formed between adjacent grooves 33 to separate the adjacent grooves 33. That is, the liquid phase guide member 30A shown in Figures 2A, 2B, 3C, and 4 has projections and recesses formed on the surface to guide liquid water toward the trailing edge 21T of the airfoil portion 21.

[0026] As shown in Fig. 5A, the liquid guide member 30B (30) may be a member having a hydrophilic surface 34 in which fine irregularities are formed on the surface 30a to provide hydrophilicity. The hydrophilic surface 34 can be obtained by drawing a fine pattern on the surface 30a of the liquid guide member 30B by, for example, laser etching. That is, the liquid guide member 30B shown in Fig. 5A has irregularities formed on the surface to guide liquid water toward the trailing edge 21T of the airfoil portion 21.

[0027] 5B, the liquid phase guide member 30C (30) may be a member having a hydrophilic coating 35 applied to the surface 30a to provide hydrophilicity. The hydrophilic coating 35 can be obtained by forming a thin film of, for example, SiO2 or TiO2 on the surface 30a.

[0028] In the following description, when there is no need to distinguish between the liquid phase guide member 30A shown in Figures 2A, 2B, 3C, and 4, the liquid phase guide member 30B shown in Figure 5A, and the liquid phase guide member 30C shown in Figure 5B, or when these liquid phase guide members 30A, 30B, and 30C are referred to collectively, the alphabet at the end of the reference numeral will be omitted and they will simply be referred to as the liquid phase guide member 30.

[0029] In the stator vane 9 according to some embodiments, for example as shown in FIG. 2A, the liquid phase guide member 30 shown in any one of FIG. 4, FIG. 5A, or FIG. 5B may be arranged in one recess 23 formed in the blade surface 22a on the pressure side 22.

[0030] 2B , the recess 23 may include a first recess 23A and a second recess 23B formed at a position in the blade height direction different from the first recess 23A. The liquid phase guide member 30 may include a first liquid phase guide member 301 inserted into and fixed in the first recess 23A, and a second liquid phase guide member 302 inserted into and fixed in the second recess 23B. As a result, even when the liquid phase guide member 30 is provided over a relatively wide range in the blade height direction, the range in which the through holes 27 are provided can be made relatively narrow.

[0031] The liquid phase guide member 30 shown in any one of FIG. 4, FIG. 5A, and FIG. 5B may be arranged in the first recess 23A and the second recess 23B. In addition, the liquid phase guide member 30 placed in the first recess 23A and the liquid phase guide member 30 placed in the second recess 23B may be the same type of liquid phase guide member 30, for example, both being liquid phase guide member 30A. Furthermore, the liquid phase guide member 30 placed in the first recess 23A and the liquid phase guide member 30 placed in the second recess 23B may be different types of liquid phase guide member 30, for example, the liquid phase guide member 30A is placed in the first recess 23A and the liquid phase guide member 30B is placed in the second recess 23B.

[0032] In the stator vane 9 according to some embodiments, as described above, the height in the blade thickness direction of the convex portion 31 of the liquid phase guide member 30A, the height in the blade thickness direction of the convex portion of the hydrophilic treated surface 34 of the liquid phase guide member 30B, or the height in the blade thickness direction of the surface of the hydrophilic coating 35 of the liquid phase guide member 30C may be the same as the height in the blade thickness direction of the blade surface 22a of the pressure side 22 of the airfoil portion 21. This allows the liquid water to be guided efficiently.

[0033] FIG. 6A is a schematic diagram showing an example of a liquid phase guide member 30A. FIG. 6B is a schematic diagram showing another example of the liquid phase guide member 30A. FIG. 6C is an exploded cross-sectional view taken along the line DD in FIG. 6B. FIG. 7 is a schematic diagram showing still another example of the liquid phase guide member 30A. FIG. 8 is a schematic diagram showing still another example of the liquid phase guide member 30A. FIG. 9 is a schematic diagram showing still another example of the liquid phase guide member 30A.

[0034] In the stator vane 9 according to some embodiments, as shown in FIGS. 6A, 7, 8, and 9, the grooves 33 may be formed over the entire area of ​​the liquid phase guide member 30A in the blade height direction. Similarly, in the stator blade 9 according to some embodiments, the region where the hydrophilic surface 34 is formed and the region where the hydrophilic coating 35 is applied may be the entire region in the blade height direction of the liquid phase guide members 30B and 30C. That is, the regions where the concaves and convexes are formed in the liquid guide member 30A and the liquid guide member 30B, or the regions where the hydrophilic coating 35 is applied, may be the entire region of the liquid guide member 30 in the blade height direction. This allows liquid water to be efficiently guided to the through-holes 27 over the entire region of the liquid guide member 30A in the blade height direction.

[0035] In the stator vane 9 according to some embodiments, as shown in FIGS. 6B and 6C, the formation region of the grooves 33 may be a partial region in the blade height direction in the liquid phase guide member 30. Similarly, in the stator blade 9 according to some embodiments, the region where the hydrophilic surface 34 is formed and the region where the hydrophilic coating 35 is applied may be a partial region in the blade height direction of the liquid phase guide members 30B and 30C. That is, the regions where the concaves and convexes are formed in the liquid guide member 30A and the liquid guide member 30B, or the regions where the hydrophilic coating 35 is applied, may be a partial region in the blade height direction in the liquid guide member 30. This allows the range in which liquid water is collected to be changed as needed, making it easier to accommodate differences in the distribution conditions of liquid water in the airfoil portion 21.

[0036] In the stator vane 9 according to some embodiments, as shown in FIG. 2B, a partial area of ​​the first liquid phase guide member 301 and a partial area of ​​the second liquid phase guide member 302 may overlap in the blade height direction. For example, in Figure 2B, a portion of the radially inner region of the first liquid phase guide member 301 and a portion of the radially outer region of the second liquid phase guide member 302 overlap in the blade height direction by the radial distance (blade height direction) sandwiched between two dotted lines. This allows liquid water to be collected efficiently over a relatively wide range in the blade height direction.

[0037] In the stator vane 9 according to some embodiments, as shown in Figures 3C and 4, the irregularities for guiding liquid water toward the trailing edge 21T of the airfoil portion 21 are formed by a plurality of grooves 33 extending from the leading edge 21L of the airfoil portion 21 toward the trailing edge 21T. This allows the plurality of grooves to efficiently collect liquid water in the through-holes.

[0038] In the stator vane 9 according to some embodiments, as shown in FIG. 6A, at least one of the plurality of grooves 33 in the liquid phase guide member 30A may be formed linearly when viewed in the blade thickness direction. This simplifies the configuration of the liquid phase guide member 30A.

[0039] In the stator vane 9 according to some embodiments, as shown in FIG. 7, at least one of the plurality of grooves 33 in the liquid phase guide member 30A may be formed in a curved shape in at least a portion of the region when viewed in the blade thickness direction. This allows the grooves 33 to be formed in the direction in which liquid water tends to flow under the influence of the flow of steam flowing through the steam turbine 1, for example, so that the liquid water can be collected efficiently.

[0040] In the stator vane 9 according to some embodiments, among the plurality of grooves 33 in the liquid phase guide member 30A, the distance L between two adjacent grooves 33 in the blade height direction may be the same in the region on the leading edge 21L side and the region on the trailing edge 21T side of the airfoil portion 21, for example, as shown in FIG. 6A.

[0041] In some embodiments of the stator vane 9, the distance L between two adjacent grooves 33 in the blade height direction among the multiple grooves 33 in the liquid phase guide member 30A may be different between the region on the leading edge 21L side of the airfoil portion 21 and the region on the trailing edge 21T side, for example, as shown in Figure 8. This allows the range in which liquid water is collected to be changed as needed by adjusting the spacing between the grooves 33 as needed, making it easier to accommodate differences in the distribution conditions of liquid water in the airfoil portion 21.

[0042] In some embodiments of the stator vane 9, the width W of the multiple grooves 33 in the liquid phase guide member 30A may be the same in the region on the leading edge 21L side of the airfoil portion 21 and the region on the trailing edge 21T side, as shown in FIG. 6A, for example.

[0043] In the stator vane 9 according to some embodiments, the width W of at least one of the plurality of grooves 33 in the liquid phase guide member 30A may be different between the region on the leading edge 21L side of the airfoil portion 21 and the region on the trailing edge 21T side, as shown in FIG. 9, for example. This allows the range in which liquid water is collected to be changed appropriately by appropriately adjusting the width W of the groove 33, making it easier to accommodate differences in the distribution conditions of liquid water in the airfoil portion 21.

[0044] (Regarding the manufacturing method of the stationary blade 9) FIG. 10 is a flowchart showing the steps of a method for manufacturing the stator blade 9 according to some of the above-described embodiments. A manufacturing method of the stator blade 9 according to some embodiments includes step S10 of forming the through hole 27, step S20 of forming the recess 23, and step S30 of inserting and fixing the liquid phase guide member 30 into the recess 23.

[0045] Step S10 of forming through hole 27 is a step of forming through hole 27 that communicates with internal space 25 of airfoil portion 21 at a position closer to trailing edge 21T of airfoil portion 21 than recess 23, which will be formed later, in airfoil wall 24 on pressure side 22 of airfoil portion 21. In step S10 of forming through hole 27, for example, guide groove 28 is formed by cutting or electric discharge machining, and then through hole 27 is formed also by cutting or electric discharge machining.

[0046] Step S20 of forming the recess 23 is a step of forming the recess 23 in the blade surface 22a of the pressure side 22 of the airfoil portion 21. In step S20 of forming the recess 23, the recess 23 is formed in the blade surface 22a of the pressure side 22 of the airfoil portion 21 by, for example, cutting or electric discharge machining. It should be noted that either step S10 of forming the through holes 27 or step S20 of forming the recesses 23 may be performed first.

[0047] Step S30 of inserting and fixing the liquid phase guide member 30 in the recess 23 is a step of inserting and fixing the liquid phase guide member 30 in the recess 23 formed in step S20 of forming the recess 23. In step S30 of inserting and fixing the liquid phase guide member 30 in the recess 23, the liquid phase guide member 30 is inserted into the recess 23 and fixed to the recess 23 by welding or using an adhesive.

[0048] According to the manufacturing method of the stator vane 9 according to some embodiments, it is possible to provide a stator vane 9 that can efficiently remove liquid water adhering to the surfaces of the airfoil portion 21 and the liquid phase guide member 30 while suppressing the cost of providing through holes 27 in a relatively large stator vane 9.

[0049] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications. For example, in the stator vane 9 according to some embodiments, the recess 23, the guide groove 28, and the through hole 27 are provided in the blade wall 24 on the pressure side 22, and the liquid phase guide member 30 is arranged therein. However, the recess 23, the guide groove 28, and the through hole 27 may be provided in the blade wall 24 on the suction side 29, and the liquid phase guide member 30 may be arranged therein.

[0050] The contents described in each of the above embodiments can be understood, for example, as follows. (1) A steam turbine blade (stator blade 9) according to at least one embodiment of the present disclosure comprises a recess 23 formed on the surface of the blade (airfoil portion 21), a liquid phase guide member 30 inserted into and fixed in the recess 23, and having irregularities (protrusions 31 and grooves 33, or a hydrophilic surface 34) formed on the surface for guiding liquid phase water toward the trailing edge 21T of the blade (airfoil portion 21) or having a hydrophilic coating 35 applied thereto, and a through hole 27 for taking in the liquid phase water guided by the liquid phase guide member 30 into the internal space 25 of the blade (airfoil portion 21).

[0051] According to the configuration (1) above, liquid water can be guided to the through holes 27 by the liquid-phase guide members 30, thereby narrowing the area in which the through holes 27 are provided. This makes it possible to efficiently remove liquid water adhering to the surfaces of the blades (stator blades 9) and the liquid-phase guide members 30 while suppressing the cost of providing the through holes 27 in the relatively large blades (stator blades 9).

[0052] (2) In some embodiments, in the configuration of (1) above, the height in the blade thickness direction of the convex portions (convex portions 31 or hydrophilic surface 34) of the unevenness (convex portions 31 and grooves 33, or hydrophilic surface 34), or the height in the blade thickness direction of the surface 30a of the liquid phase guide member 30 to which the hydrophilic coating 35 is applied, may be the same as the height in the blade thickness direction of the blade surface 22a of the blade (airfoil portion 21).

[0053] According to the above configuration (2), liquid water can be efficiently guided.

[0054] (3) In some embodiments, in the configuration of (1) or (2) above, the liquid phase guiding member 30A may be a press-molded product.

[0055] According to the above configuration (3), the manufacturing cost of the liquid phase guide member 30A can be reduced.

[0056] (4) In some embodiments, in any of the configurations (1) to (3) above, the formation area of ​​the unevenness (the convex portion 31 and the groove 33, or the hydrophilic surface 34) or the application area of ​​the hydrophilic coating 35 may be a partial area in the blade height direction in the liquid phase guide member 30.

[0057] According to the configuration (4) above, the range in which liquid water is collected can be changed as needed, making it easier to accommodate differences in the distribution conditions of liquid water in the blade (airfoil portion 21).

[0058] (5) In some embodiments, in any of the configurations (1) to (4) above, the recess 23 may include a first recess 23A and a second recess 23B formed at a position in the blade height direction different from the first recess 23A. The liquid guide member 30 may include a first liquid guide member 301 inserted into and fixed to the first recess 23A, and a second liquid guide member 302 inserted into and fixed to the second recess 23B.

[0059] According to the above configuration (5), even when the liquid phase guide member 30 is provided over a relatively wide range in the blade height direction, the range in which the through holes 27 are provided can be made relatively narrow.

[0060] (6) In some embodiments, in the configuration of (5) above, a partial area of ​​the first liquid phase guide member 301 and a partial area of ​​the second liquid phase guide member 302 may overlap in the blade height direction.

[0061] According to the above configuration (6), liquid water can be efficiently collected over a relatively wide range in the blade height direction.

[0062] (7) In some embodiments, in any of the configurations (1) to (6) above, the unevenness (the convex portions 31 and the grooves 33, or the hydrophilic surface 34) may be formed by a plurality of grooves 33 extending from the leading edge 21L of the wing (airfoil portion 21) toward the trailing edge 21T.

[0063] According to the above configuration (7), the plurality of grooves 33 can efficiently collect liquid water in the through-holes 27.

[0064] (8) In some embodiments, in the configuration of (7) above, at least one of the plurality of grooves 33 may be formed linearly when viewed in the blade thickness direction.

[0065] According to the above configuration (8), the configuration of the liquid phase guide member 30A can be simplified.

[0066] (9) In some embodiments, in the configuration of (7) or (8) above, at least one of the plurality of grooves 33 may be formed in a curved shape in at least a portion of the area when viewed in the blade thickness direction.

[0067] According to the configuration (9) above, the grooves 33 can be formed in the direction in which the liquid water tends to flow due to the influence of the steam flowing through the steam turbine 1, for example, so that the liquid water can be efficiently collected.

[0068] (10) In some embodiments, in any of the configurations (7) to (9) above, the distance L between two adjacent grooves 33 in the blade height direction among the multiple grooves 33 may be different between the region on the leading edge 21L side of the blade (airfoil portion 21) and the region on the trailing edge 21T side.

[0069] According to the configuration (10) above, the range in which liquid water is collected can be changed appropriately by appropriately adjusting the spacing L between the grooves 33, making it easier to accommodate differences in the distribution conditions of liquid water in the blade (airfoil portion 21).

[0070] (11) In some embodiments, in any of the configurations (7) to (10) above, the width W of at least one of the multiple grooves 33 may be different between the region of the leading edge 21L of the wing (airfoil portion 21) and the region on the trailing edge 21T side.

[0071] According to the configuration (11) above, the range in which liquid water is collected can be changed appropriately by appropriately adjusting the width W of the groove 33, making it easier to accommodate differences in the distribution conditions of liquid water in the blade (airfoil portion 21).

[0072] (12) A steam turbine 1 according to at least one embodiment of the present disclosure includes a steam turbine blade (stator blade 9) having any one of the configurations described above in (1) to (11).

[0073] According to the configuration (12) above, it is possible to efficiently remove liquid water adhering to the surfaces of the blade (stator blade 9) and the liquid phase guide member 30 while suppressing the cost of providing a through hole 27 in a relatively large blade (stator blade 9).

[0074] (13) A method for manufacturing a steam turbine blade according to at least one embodiment of the present disclosure is a method for manufacturing a steam turbine blade, and includes step S20 of forming a recess 23 on the surface of the blade (airfoil portion 21), step S10 of forming a through hole 27 communicating with the internal space 25 of the blade (airfoil portion 21) at a position closer to the trailing edge 21T of the blade (airfoil portion 21) than the recess 23, and step S30 of inserting and fixing a liquid phase guide member 30 having irregularities (protrusions 31 and grooves 33, or a hydrophilic surface 34) on its surface for guiding liquid phase water toward the trailing edge 21T of the blade or having a hydrophilic coating 35 applied thereto, into the recess 23.

[0075] According to the method (13) above, liquid water can be guided to the through holes 27 by the liquid-phase guide member 30, thereby narrowing the area in which the through holes 27 are provided. This makes it possible to provide a blade (stationary blade 9) that can efficiently remove liquid water adhering to the surfaces of the blade (stationary blade 9) and the liquid-phase guide member 30, while suppressing the cost of providing the through holes 27 in a relatively large blade (stationary blade 9). [Explanation of symbols]

[0076] 1. Steam turbine 9 Stator blades 21 Airfoil 21L leading edge 21T trailing edge 23 Recess 23A First recess 23B Second recess 24 Wing wall 25 Interior Space 27 Through hole 28 Guide groove 30, 30A, 30B, 30C liquid phase guide member 31 Convex part 33 Groove 34 Hydrophilic surface 35 Hydrophilic Coating 301 First liquid phase guide member 302 Second liquid phase guide member

Claims

1. a recess formed on the surface of the wing and separated from an internal space of the wing by a wing wall of the wing; a liquid guide member that is inserted into and fixed to the recess, and has a surface on which irregularities for guiding liquid water to the trailing edge side of the blade are formed or on which a hydrophilic coating is applied; a through hole for taking the liquid water guided by the liquid guide member into the internal space; A steam turbine blade comprising:

2. a height in the blade thickness direction of the convex portions of the concave-convex portions or a height in the blade thickness direction of the surface of the liquid phase guiding member on which the hydrophilic coating is applied is the same as a height in the blade thickness direction of the blade surface of the blade. The steam turbine blade according to claim 1 .

3. The liquid phase guide member is a press-molded product. The steam turbine blade according to claim 1 or 2.

4. The region where the irregularities are formed or the region where the hydrophilic coating is applied is a part of the region in the blade height direction of the liquid phase guide member. The steam turbine blade according to claim 1 or 2.

5. The recessed portion includes a first recessed portion and a second recessed portion formed at a position different from the first recessed portion in the blade height direction, The liquid guide member includes a first liquid guide member inserted into and fixed to the first recess, and a second liquid guide member inserted into and fixed to the second recess. The steam turbine blade according to claim 1 or 2.

6. a partial region of the first liquid phase guide member and a partial region of the second liquid phase guide member overlap in the blade height direction; The steam turbine blade according to claim 5 .

7. The irregularities are formed by a plurality of grooves extending from the leading edge to the trailing edge of the wing. The steam turbine blade according to claim 1 or 2.

8. At least one of the plurality of grooves is formed linearly when viewed from the blade thickness direction. The steam turbine blade according to claim 7.

9. At least one of the plurality of grooves is formed in a curved shape in at least a portion thereof when viewed in the blade thickness direction. The steam turbine blade according to claim 7.

10. Among the plurality of grooves, a distance between two adjacent grooves in the blade height direction is different between a leading edge region and a trailing edge region of the blade. The steam turbine blade according to claim 7.

11. At least one of the plurality of grooves has a groove width that differs between a leading edge region and a trailing edge region of the blade. The steam turbine blade according to claim 7.

12. A steam turbine comprising the steam turbine blade according to claim 1 or 2.

13. A method for manufacturing a steam turbine blade, comprising: forming a recess in a surface of the wing, the recess being separated from an interior space of the wing by a wing wall of the wing; forming a through hole communicating with the internal space at a position closer to the trailing edge of the blade than the recess; a step of inserting and fixing a liquid phase guide member, the liquid phase guide member having a surface formed with irregularities for guiding liquid phase water to the trailing edge side of the blade or having a hydrophilic coating, into the recess; A method for manufacturing a steam turbine blade comprising:

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