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

Abstract

A steam turbine blade according to at least one embodiment of the present invention is provided with: a recess formed in the surface of the blade; a liquid-phase guide member which is inserted and fixed in the recess, and on the surface of which recesses and protrusions for guiding liquid-phase water to the trailing edge side of the blade are formed or which is coated with a hydrophilic coating layer; and a through hole for introducing the liquid phase water guided by the liquid phase guide member into the inner space of the blade.

Description

Technical Field

[0001] The present invention relates to a steam turbine blade, a steam turbine, and a method for manufacturing the steam turbine blade.

[0002] This application claims priority based on Japanese Patent Application No. 2022-181285 filed in Japan on November 11, 2022, and the contents are incorporated herein by reference. Background Art

[0003] Steam passing through a steam turbine loses energy as it moves from the upstream side to the downstream side, causing the temperature and pressure to drop. Therefore, in the downstream stage of the steam turbine, part of the steam condenses and exists in the airflow as fine water droplets, and part of the water droplets adhere to the surface of the turbine fixed blades and immediately grow on the blade surface to form a liquid film. If the liquid film grows further and becomes thicker, part of it is torn apart by the steam flow and dispersed in the form of coarse droplets. If the dispersed droplets collide with the turbine blades, the rotation of the turbine blades may be hindered, causing brake loss or corrosion.

[0004] Therefore, for example, the following is also performed: a fine slit is formed in the blade surface of a hollow fixed blade to connect the internal space inside the fixed blade with the outside of the fixed blade, and the moisture (liquid phase) attached to the surface of the fixed blade is sucked into the internal space by the pressure difference using the slit, thereby suppressing the dispersion of droplets (for example, refer to Patent Document 1).

[0005] Previous technical literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2021-181773 Summary of the invention

[0006] Technical issues to be solved by the invention

[0007] As described above, the droplets are generated in the relatively downstream stage of the steam turbine. In the relatively downstream stage of the steam turbine, the size of the turbine blades is relatively large. Therefore, it is difficult to form fine slits in relatively large turbine blades, and there is a problem of increased cost.

[0008] In view of the above circumstances, an object of at least one embodiment of the present invention is to effectively remove liquid-phase water adhering to the surface of a blade while suppressing an increase in cost.

[0009] Means for solving technical problems

[0010] (1) A steam turbine blade according to at least one embodiment of the present invention includes: A concave portion, formed on the surface of the blade; a liquid phase guide member, which is inserted into and fixed to the recessed portion and has a surface formed with recesses and projections for guiding liquid phase water to the trailing edge side of the blade or is coated with a hydrophilic coating; and The through hole is used to introduce the liquid phase water guided by the liquid phase guide member into the inner space of the blade.

[0011] (2) A steam turbine according to at least one embodiment of the present invention includes a steam turbine blade having the structure of (1) above.

[0012] (3) A method for manufacturing a steam turbine blade according to at least one embodiment of the present invention is a method for manufacturing a steam turbine blade, comprising the following steps: The step of forming a recess on the surface of the blade; A step of 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 recessed portion; and A step of inserting and fixing a liquid phase guide member having concavities and convexities formed on the surface for guiding liquid phase water to the trailing edge side of the blade or coated with a hydrophilic coating into the concave portion.

[0013] Effects of the Invention

[0014] According to at least one embodiment of the present invention, it is possible to effectively remove liquid adhering to the surface of a blade while suppressing an increase in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic cross-sectional view along the axial direction of a steam turbine according to one embodiment. Figure 2A This is a schematic diagram showing the airfoil surface on the ventral side of the airfoil portion of the stationary blade in the downstream stage among the multiple stages of stationary blades. Figure 2B This is a schematic diagram showing the airfoil surface on the ventral side of the airfoil portion of the stationary blade in the downstream stage among the multiple stages of stationary blades. Figure 3A yes Figure 2A Cross-sectional view along AA direction. Figure 3B yes Figure 2A Cross-sectional view along direction BB. Figure 3C yes Figure 2A Cross-sectional view along CC direction. Figure 4 is equivalent to Figure 3C Figure 1. Exploded view of the diagram. Figure 5A is equivalent to Figure 4 , and is a diagram when a liquid phase guide component involved in another embodiment is used. Figure 5B is equivalent to Figure 4 , and is a diagram of another embodiment in which a liquid phase guide component is used. Fig. 6A It is a schematic diagram showing an example of a liquid phase guide member. Figure 6B It is a schematic diagram showing another example of the liquid phase guide member. Figure 6C yes Figure 6B Exploded view of the cross section along the DD direction. Figure 7 It is a schematic diagram showing still another example of the liquid phase guide member. Figure 8 It is a schematic diagram showing still another example of the liquid phase guide member. Fig. 9 It is a schematic diagram showing still another example of the liquid phase guide member. Fig.10 It is a flowchart showing the procedure of a method for manufacturing a stationary blade according to some embodiments. DETAILED DESCRIPTION

[0016] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. The dimensions, materials, shapes, and relative arrangements of the components described as embodiments or shown in the accompanying drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0017] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" indicating relative or absolute configuration strictly speaking not only indicate such configuration, but also indicate the state of relative displacement at an angle or distance to the extent that there is a tolerance or the same function can be obtained.

[0018] For example, expressions such as “same”, “equal” and “uniform” that indicate that things are in an equal state not only indicate an equal state in a strict sense, but also indicate a state in which there is a tolerance or a difference in degree to which the same function can be obtained.

[0019] For example, expressions indicating shapes such as a quadrilateral or a cylinder not only indicate shapes such as a quadrilateral or a cylinder in a strict geometric sense, but also indicate shapes including concave-convex portions or chamfered portions as long as the same effect can be obtained.

[0020] On the other hand, the expression “having”, “configured”, “including”, “comprising” or “having” for a constituent element is not an exclusive expression which excludes the existence of other constituent elements.

[0021] First, the overall structure of a steam turbine according to some embodiments will be described.

[0022] Figure 1 1 is a schematic cross-sectional view along the axial direction of a steam turbine according to an embodiment of the present invention. Figure 1 As shown, the steam turbine 1 includes: a rotor 2 rotatably supported by a bearing 6 about a central axis O; a plurality of moving blades 8 mounted on the rotor 2; an inner casing 10 accommodating the rotor 2 and the moving blades 8; and a plurality of stationary blades 9 mounted on the inner casing 10 in a manner opposed to the moving blades 8. In addition, an outer casing 12 is provided on the outer side of the inner casing 10. In such a steam turbine 1, when steam is introduced from the steam inlet 3 to the inner casing 10, the steam expands and accelerates when passing through the stationary blades 9, thereby operating the moving blades 8 and rotating the rotor 2.

[0023] Furthermore, the steam turbine 1 includes an exhaust chamber 14. Figure 1 As shown, the exhaust chamber 14 is located on the downstream side of the moving blades 8 and the fixed blades 9. The steam (steam flow Fs) passing through the moving blades 8 and the fixed blades 9 in the inner casing 10 flows into the exhaust chamber 14 from the 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 the 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 completed the work on the moving blades 8 in the steam turbine 1 flows from the exhaust chamber 14 to the condenser via the exhaust chamber outlet 13.

[0024] Figure 2A The schematic diagram shows the blade surface 22 a of the ventral side 22 of the airfoil portion 21 of the stationary blade 9 in the downstream stage among the multiple stages of stationary blades 9 , and shows an example of the arrangement of a liquid phase guide member 30 according to an embodiment described later.

[0025] Figure 2B The schematic diagram shows the blade surface 22 a of the ventral side 22 of the airfoil portion 21 of the stationary blade 9 in the downstream stage among the multiple stages of stationary blades 9 , and shows another example of the arrangement of the liquid phase guide member 30 according to an embodiment described later.

[0026] Figure 3A yes Figure 2A Cross-sectional view along AA direction.

[0027] Figure 3B yes Figure 2A Cross-sectional view along direction BB.

[0028] Figure 3C yes Figure 2A Cross-sectional view along CC direction.

[0029] Figure 4 is equivalent to Figure 3C Figure 1. Exploded view of the diagram.

[0030] Figure 5A is equivalent to Figure 4 , and is a diagram when a liquid phase guide component 30 involved in another embodiment is used.

[0031] Figure 5B is equivalent to Figure 4 , and is a diagram of a case where a liquid phase guide component 30 is used according to yet another embodiment.

[0032] In the following description, unless otherwise specified, the stationary blades 9 are stationary blades 9 in a downstream stage among the multiple stages of stationary blades 9 .

[0033] The fixed blade 9 involved in some embodiments includes: a recess 23 formed on the surface of the blade (airfoil portion 21); a liquid phase guide component 30 inserted and fixed in the recess 23 and used to guide liquid phase water to the trailing edge 21T side of the blade; a through hole 27 for introducing the liquid phase water guided by the liquid phase guide component 30 into the internal space 25 of the airfoil portion 21; and a guide groove 28.

[0034] The airfoil portion 21 of the stationary blade 9 according to some embodiments has a hollow structure. As described later, the stationary blade 9 according to some embodiments is configured to be able to discharge liquid phase water introduced into the internal space 25 to the outside of the airfoil portion 21 .

[0035] (recess 23)

[0036] In the stationary blade 9 according to some embodiments, the recessed portion 23 is a recessed portion formed on the airfoil 22a of the ventral side 22 for mounting the liquid-phase guiding member 30. The depth of the recessed portion 23 may be set so that the height of the convex portion 31 (described later) of the liquid-phase guiding member 30 mounted on the recessed portion 23 is the same as the height of the airfoil 22a around the recessed portion 23 of the airfoil 21 in the blade thickness direction, that is, so that the convex portion 31 of the liquid-phase guiding member 30 does not protrude from the airfoil 22a around the recessed portion 23 of the airfoil 21.

[0037] (Overview of Liquid Phase Guide Member 30)

[0038] In the stationary blade 9 according to some embodiments, the liquid-phase guide member 30 is a member for effectively guiding the liquid-phase water on the surface of the liquid-phase guide member 30 to the through-hole 27 described later.

[0039] exist Figure 2A , Figure 2B , Figure 3C and Figure 4In the illustrated example, a plurality of grooves 33 extending from the leading edge 21L toward the trailing edge 21T of the airfoil 21 are formed in the liquid-phase guide member 30 .

[0040] exist Figure 5A In the example shown, the liquid phase guide member 30 is a member having fine concavities and convexities formed on the surface 30 a for obtaining hydrophilicity.

[0041] exist Figure 5B In the illustrated example, the liquid phase guide member 30 is a member having a surface 30 a coated with a hydrophilic coating for imparting hydrophilicity.

[0042] In addition, the details of the liquid phase guide member 30 will be described later.

[0043] In the stationary blade 9 according to some embodiments, the liquid-phase guide member 30 is fixed to the recessed portion 23 by welding or using an adhesive.

[0044] (Through hole 27 and guide groove 28)

[0045] like Figure 2A , Figure 2B and Figure 3B As shown, a plurality of through holes 27 for introducing liquid phase water guided by the liquid phase guide member 30 into the internal space 25 of the airfoil portion 21 are formed in the stationary blade 9 according to some embodiments.

[0046] In the stationary blade 9 according to some embodiments, the through holes 27 are holes penetrating the wing wall 24 on the ventral 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 .

[0047] The through holes 27 are relatively fine holes. Therefore, in order to effectively guide the liquid phase water guided by the liquid phase guide member 30 to the relatively fine multiple through holes 27, a guide groove 28 is formed on the wing wall 24 on the ventral side 22 of the airfoil portion 21 in the form of multiple through holes 27 arranged at intervals in the blade height direction.

[0048] A plurality of through holes 27 are provided so as to open at the bottom 28 a of the guide groove 28 .

[0049] (Advantages of Providing the Liquid Phase Guide Component 30)

[0050] In the stationary blade 9 according to some embodiments, the liquid phase water adhering to the airfoil 22a of the ventral side 22 of the airfoil portion 21 within the range R of collecting the liquid phase water is affected by the steam flow Fs and flows along the Figure 2A and Figure 2BThe liquid phase water flows in the direction of the arrow a. The liquid phase water is guided to the through hole 27 by the liquid phase guide member 30 and the guide groove 28 provided in the above-mentioned range R, and is introduced into the internal space 25.

[0051] For example, in the conventional fixed blade 9 which does not include the liquid phase guide member 30, in addition to Figure 2A In addition to the guide groove 28, it is also necessary to form, for example, Figure 2A The guide groove 28 shown by the two-dot chain line is formed so as to form a relatively long guide groove 28 to correspond to the above-mentioned range R, and more through holes 27 are provided.

[0052] However, the blade size of the stationary blades 9 in the downstream stage is relatively large. Therefore, forming the fine through-holes 27 or the guide grooves 28 in the relatively large stationary blades 9 is difficult to process and there is a problem of increased cost.

[0053] In this regard, according to the stationary blade 9 involved in some embodiments, the liquid phase water can be guided to the through hole by the liquid phase guide member 30, so the range of setting the through hole 27 can be narrowed, and the number of the through holes 27 can be reduced, thereby shortening the length of the guide groove 28. As a result, the cost for providing the through hole 27 or the guide groove 28 on the relatively large stationary blade 9 can be suppressed, and the liquid phase water attached to the surface of the airfoil portion 21 can be effectively removed.

[0054] In the steam turbine 1 including the stationary blades 9 according to some embodiments, the cost for providing the through holes 27 in the relatively large stationary blades 9 can be reduced, and liquid phase water adhering to the surfaces of the stationary blades 9 or the liquid phase guide members 30 can be effectively removed.

[0055] (Details of the Liquid Phase Guide Component 30)

[0056] exist Figure 2A , Figure 2B , Figure 3C and Figure 4 In the example shown, the liquid phase guide member 30A (30) can be formed, for example, by bending a plate-like member to form a plurality of grooves 33 extending from the front edge 21L toward the rear edge 21T. For example, by stamping the plate-like member, the liquid phase guide member 30A of such a shape can be obtained as a stamped product.

[0057] Thereby, the manufacturing cost of the liquid phase guide member can be suppressed.

[0058] The liquid phase guide member 30A formed in this way has a plurality of grooves 33 and convex portions 31 formed between adjacent grooves 33 and separating adjacent grooves 33. That is, Figure 2A , Figure 2B , Figure 3C and Figure 4 The illustrated liquid phase guide member 30A has projections and depressions formed on the surface thereof for guiding liquid phase water to the trailing edge 21T side of the airfoil portion 21 .

[0059] like Figure 5A As shown, the liquid phase guiding member 30B (30) may be a member having a hydrophilic surface 34 formed with fine concavo-convex patterns on the surface 30a for obtaining hydrophilicity. The hydrophilic surface 34 is obtained by drawing a fine pattern on the surface 30a of the liquid phase guiding member 30B by laser etching or the like. That is, Figure 5A The illustrated liquid phase guide member 30B has concavities and convexities formed on the surface for guiding liquid phase water to the trailing edge 21T side of the airfoil portion 21 .

[0060] like Figure 5B As shown, the liquid phase guide member 30C (30) may be a member having a hydrophilic coating 35 coated on the surface 30a for obtaining hydrophilicity. The hydrophilic coating 35 is obtained by, for example, forming a thin film made of SiO2 or TiO2 on the surface 30a.

[0061] In addition, in the following description, it is not necessary to distinguish Figure 2A , Figure 2B , Figure 3C and Figure 4 The liquid phase guiding member 30A shown, Figure 5A The liquid phase guide member 30B and Figure 5B In the case of the liquid phase guide member 30C shown, or in the case of unifying the names of the liquid phase guide members 30A, 30B, and 30C, the letters at the end of the symbols are omitted and the liquid phase guide member 30 is simply referred to as the liquid phase guide member 30.

[0062] In some embodiments of the present invention, for example, the fixed blade 9 is Figure 2A As shown, the concave portion 23 formed at one location on the blade surface 22a of the ventral side 22 may be configured Figure 4 , Figure 5A or Figure 5B The liquid phase guiding component 30 shown in any of the figures.

[0063] Furthermore, in some embodiments of the fixed blade 9, for example, Figure 2B As shown, the recess 23 may include a first recess 23A and a second recess 23B, wherein the second recess 23B is formed at a position different from the first recess 23A in the blade height direction. The liquid phase guide member 30 may include a first liquid phase guide member 301 inserted and fixed to the first recess 23A and a second liquid phase guide member 302 inserted and fixed to the second recess 23B.

[0064] Thus, even when the liquid-phase guide member 30 is provided in a relatively wide range in the blade height direction, the range in which the through-holes 27 are provided can be relatively narrowed.

[0065] In the first recess 23A and the second recess 23B, Figure 4 , Figure 5A or Figure 5B The liquid phase guiding component 30 shown in any of the figures.

[0066] In addition, the liquid phase guiding member 30 arranged in the first recess 23A and the liquid phase guiding member 30 arranged in the second recess 23B may be the same type of liquid phase guiding members 30 such as the liquid phase guiding member 30A.

[0067] Furthermore, the liquid phase guiding component 30 arranged in the first recess 23A and the liquid phase guiding component 30 arranged in the second recess 23B may be different types of liquid phase guiding components 30, for example, the liquid phase guiding component 30A is arranged in the first recess 23A and the liquid phase guiding component 30B is arranged in the second recess 23B.

[0068] As described above, in the fixed blade 9 involved in some embodiments, the height of the protrusion 31 of the liquid phase guiding component 30A in the blade thickness direction, the height of the protrusion of the hydrophilic processed surface 34 of the liquid phase guiding component 30B in the blade thickness direction, or the height of the surface of the hydrophilic coating 35 of the liquid phase guiding component 30C in the blade thickness direction only needs to be the same as the height of the airfoil 22a of the ventral side 22 of the airfoil portion 21 in the blade thickness direction.

[0069] Thereby, liquid phase water can be efficiently guided.

[0070] Fig. 6A It is a schematic diagram showing an example of the liquid phase guide member 30A.

[0071] Figure 6B It is a schematic diagram showing another example of the liquid phase guide member 30A.

[0072] Figure 6C yes Figure 6B Exploded view of the cross section along the DD direction.

[0073] Figure 7 It is a schematic diagram showing still another example of the liquid phase guide member 30A.

[0074] Figure 8 It is a schematic diagram showing still another example of the liquid phase guide member 30A.

[0075] Fig. 9 It is a schematic diagram showing still another example of the liquid phase guide member 30A.

[0076] In some embodiments of the present invention, the fixed blade 9 is Fig. 6A , Figure 7 , Figure 8 and Fig. 9 As shown, the region where the groove 33 is formed may be the entire region in the blade height direction in the liquid phase guide member 30A.

[0077] Similarly, in the stationary blade 9 according to some embodiments, the region where the hydrophilic processed 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.

[0078] That is, the region where the projections and recesses are formed or the region where the hydrophilic coating 35 is applied in the liquid phase guide member 30A and the liquid phase guide member 30B may be the entire region in the blade height direction in the liquid phase guide member 30 .

[0079] Thus, the liquid phase water can be effectively guided to the through-holes 27 over the entire region in the blade height direction in the liquid phase guide member 30A.

[0080] In some embodiments of the present invention, the fixed blade 9 is Figure 6B and Figure 6C As shown, the region where the groove 33 is formed may be a portion of the region in the liquid phase guide member 30 in the blade height direction.

[0081] Similarly, in the stationary blade 9 according to some embodiments, the region where the hydrophilic processed surface 34 is formed and the region where the hydrophilic coating 35 is applied may be a partial region in the liquid phase guide member 30B, 30C in the blade height direction.

[0082] That is, the region where the projections and recesses are formed or the region where the hydrophilic coating 35 is applied in the liquid phase guide member 30A and the liquid phase guide member 30B may be a partial region in the blade height direction of the liquid phase guide member 30 .

[0083] As a result, the range for collecting the liquid phase water can be appropriately changed, and thus it is easy to cope with differences in the distribution conditions of the liquid phase water in the airfoil portion 21 .

[0084] In some embodiments of the present invention, the fixed blade 9 is Figure 2B As shown, a part of the first liquid phase guiding member 301 and a part of the second liquid phase guiding member 302 only need to overlap in the blade height direction.

[0085] For example, in Figure 2BIn the figure, a portion of the radially inner region of the first liquid phase guiding member 301 and a portion of the radially outer region of the second liquid phase guiding member 302 overlap in the blade height direction by the radial distance (blade height direction) sandwiched between the two dashed lines.

[0086] Thus, liquid phase water can be efficiently collected over a relatively wide range in the blade height direction.

[0087] In some embodiments of the present invention, the fixed blade 9 is Figure 3C and Figure 4 As shown, the concavities and convexities for guiding the liquid phase water to the trailing edge 21T side of the airfoil portion 21 are formed by a plurality of grooves 33 extending from the leading edge 21L toward the trailing edge 21T of the airfoil portion 21 .

[0088] Thus, liquid phase water can be effectively collected in the through-holes through the plurality of grooves.

[0089] In some embodiments of the present invention, the fixed blade 9 is Fig. 6A As shown, at least one of the plurality of grooves 33 in the liquid phase guide member 30A may be formed in a straight line shape when viewed in the blade thickness direction.

[0090] Thereby, the structure of the liquid phase guide member 30A can be simplified.

[0091] In some embodiments of the present invention, the fixed blade 9 is Figure 7 As shown, 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 partial region when viewed in the blade thickness direction.

[0092] Thus, for example, the grooves 33 can be formed to be aligned with the direction in which the liquid phase water attempts to flow under the influence of the flow of the steam flowing in the steam turbine 1 , and thus the liquid phase water can be efficiently collected.

[0093] In the fixed blade 9 according to some embodiments, among the plurality of grooves 33 in the liquid phase guide member 30A, the interval L between two adjacent grooves 33 in the blade height direction is, for example, Fig. 6A As shown, the region on the leading edge 21L side and the region on the trailing edge 21T side of the airfoil portion 21 may be the same.

[0094] In the fixed blade 9 according to some embodiments, among the plurality of grooves 33 in the liquid phase guide member 30A, the interval L between two adjacent grooves 33 in the blade height direction is, for example, Figure 8 As shown, the region on the leading edge 21L side and the region on the trailing edge 21T side of the airfoil portion 21 may be different.

[0095] Thus, by appropriately adjusting the intervals between the grooves 33 , the range in which the liquid phase water is collected can be appropriately changed, so that it is easy to cope with differences in the distribution conditions of the liquid phase water in the airfoil portion 21 .

[0096] In the fixed blade 9 according to some embodiments, the width W of the plurality of grooves 33 in the liquid phase guide member 30A is, for example, Fig. 6A As shown, the region on the leading edge 21L side and the region on the trailing edge 21T side of the airfoil portion 21 may be the same.

[0097] In the fixed blade 9 according to some embodiments, at least one of the plurality of grooves 33 in the liquid phase guide member 30A is formed, for example, Fig. 9 As shown, the width W of the groove 33 may be different between the region on the leading edge 21L side and the region on the trailing edge 21T side of the airfoil 21 .

[0098] Thus, by appropriately adjusting the width W of the groove 33 , the range in which the liquid phase water is collected can be appropriately changed, and thus it is easy to cope with differences in the distribution conditions of the liquid phase water in the airfoil portion 21 .

[0099] (Regarding the Manufacturing Method of the Stationary Blade 9)

[0100] Fig.10 It is a flowchart showing the procedure of the method for manufacturing the stationary blade 9 according to some of the above-mentioned embodiments.

[0101] The method for manufacturing the stationary blade 9 according to some embodiments includes a step S10 of forming the through hole 27 , a step S20 of forming the recess 23 , and a step S30 of inserting and fixing the liquid phase guide member 30 into the recess 23 .

[0102] The step S10 of forming the through hole 27 is a step of forming the through hole 27 communicating with the internal space 25 of the airfoil 21 at a position closer to the trailing edge 21T of the airfoil 21 than the recess 23 of the wing wall 24 formed later on the ventral side 22 of the airfoil 21. In the step S10 of forming the through hole 27, for example, the guide groove 28 is formed by cutting or electric discharge machining, and then the through hole 27 is formed by the same cutting or electric discharge machining.

[0103] Step S20 of forming recess 23 is a step of forming recess 23 in airfoil 22a of ventral side 22 of airfoil 21. In step S20 of forming recess 23, recess 23 is formed in airfoil 22a of ventral side 22 of airfoil 21 by cutting or electric discharge machining, for example.

[0104] Alternatively, either step S10 of forming the through hole 27 or step S20 of forming the recessed portion 23 may be performed first.

[0105] The step S30 of inserting and fixing the liquid phase guiding member 30 into the recess 23 is a step of inserting and fixing the liquid phase guiding member 30 into the recess 23 formed in the step S20 of forming the recess 23. In the step S30 of inserting and fixing the liquid phase guiding member 30 into the recess 23, the liquid phase guiding member 30 is inserted into the recess 23 and fixed to the recess 23 by welding or using an adhesive.

[0106] According to the manufacturing method of the fixed blade 9 involved in some embodiments, a fixed blade 9 can be provided, which can suppress the cost for setting the through hole 27 on the relatively large fixed blade 9 and effectively remove liquid water attached to the surface of the airfoil portion 21 or the liquid phase guide component 30.

[0107] The present invention is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment or an appropriate combination of these forms.

[0108] For example, in some embodiments of the fixed blade 9, a recess 23, a guide groove 28 and a through hole 27 are provided on the wing wall 24 on the ventral side 22, and a liquid phase guide component 30 is configured, but a recess 23, a guide groove 28 and a through hole 27 may also be provided on the wing wall 24 on the dorsal side 29, and a liquid phase guide component 30 may be configured.

[0109] For example, the contents described in each of the above-mentioned embodiments can be understood as follows.

[0110] (1) A steam turbine blade (stationary blade 9) according to at least one embodiment of the present invention includes: a recessed portion 23 formed on the surface of the blade (airfoil portion 21); a liquid phase guide member 30 inserted into and fixed to the recessed portion 23 and having recesses and projections (convex portions 31 and grooves 33 or hydrophilic processed surfaces 34) formed on the surface for guiding liquid phase water to the trailing edge 21T side of the blade (airfoil portion 21), or coated with a hydrophilic coating 35; and a through hole 27 for introducing the liquid phase water guided by the liquid phase guide member 30 into the internal space 25 of the blade (airfoil portion 21).

[0111] According to the configuration of (1) above, liquid phase water can be guided to the through hole 27 by the liquid phase guide member 30, thereby reducing the range in which the through hole 27 is provided. As a result, the cost for providing the through hole 27 in the relatively large blade (stationary blade 9) can be reduced, and liquid phase water adhering to the surface of the blade (stationary blade 9) or the liquid phase guide member 30 can be effectively removed.

[0112] (2) In some embodiments, in the structure of (1) above, the height of the convex portion (convex portion 31 or hydrophilic processed surface 34) of the above-mentioned concavo-convex portion (convex portion 31 and groove 33 or hydrophilic processed surface 34) in the blade thickness direction or the height of the surface 30a of the liquid phase guide component 30 coated with the hydrophilic coating 35 in the blade thickness direction only needs to be the same as the height of the airfoil 22a of the blade (airfoil portion 21) in the blade thickness direction.

[0113] According to the above-mentioned structure (2), liquid phase water can be efficiently guided.

[0114] (3) In some embodiments, in the configuration of (1) or (2) above, the liquid phase guide member 30A may be a press-molded product.

[0115] According to the above-mentioned configuration (3), the manufacturing cost of the liquid phase guide member 30A can be reduced.

[0116] (4) In some embodiments, in any of the structures described in (1) to (3) above, the region where the above-mentioned concavo-convex portion (convex portion 31 and groove 33 or hydrophilic processed surface 34) is formed or the region where the hydrophilic coating 35 is applied may be a portion of the region in the liquid phase guide member 30 in the blade height direction.

[0117] According to the configuration of (4) above, the range for collecting liquid phase water can be appropriately changed, so that it is easy to cope with differences in the distribution conditions of liquid phase water in the blade (airfoil portion 21 ).

[0118] (5) In some embodiments, in any of the structures described in (1) to (4), the recess 23 may include a first recess 23A and a second recess 23B, wherein the second recess 23B is formed at a position different from the first recess 23A in the blade height direction. The liquid phase guide member 30 may include a first liquid phase guide member 301 inserted into and fixed to the first recess 23A, and a second liquid phase guide member 302 inserted into and fixed to the second recess 23B.

[0119] According to the configuration of (5) above, even when the liquid phase guide member 30 is provided in a relatively wide range in the blade height direction, the range in which the through hole 27 is provided can be relatively narrowed.

[0120] (6) In some embodiments, in the configuration of (5) above, a portion of the first liquid phase guiding member 301 and a portion of the second liquid phase guiding member 302 may overlap in the blade height direction.

[0121] According to the above-mentioned structure (6), liquid phase water can be efficiently collected in a relatively wide range in the blade height direction.

[0122] (7) In some embodiments, in any of the structures (1) to (6) above, the above-mentioned concavo-convex (convex portion 31 and groove 33 or hydrophilic surface 34) only needs to be formed by a plurality of grooves 33 extending from the leading edge 21L toward the trailing edge 21T of the blade (airfoil portion 21).

[0123] According to the above-mentioned structure (7), liquid phase water can be effectively collected in the through-hole 27 by the plurality of grooves 33 .

[0124] (8) In some embodiments, in the structure of (7) above, at least one of the plurality of grooves 33 may be formed in a straight line shape when viewed in the blade thickness direction.

[0125] According to the above-mentioned structure of (8), the structure of the liquid phase guide member 30A can be simplified.

[0126] (9) In some embodiments, in the structure 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 region when viewed in the blade thickness direction.

[0127] According to the configuration of (9) above, for example, the grooves 33 can be formed to be aligned with the direction in which the liquid phase water attempts to flow under the influence of the flow of steam flowing in the steam turbine 1 , so that the liquid phase water can be efficiently collected.

[0128] (10) In some embodiments, in any of the structures described in (7) to (9) above, among the plurality of grooves 33 , the interval L between two adjacent grooves 33 in the blade height direction may be different in a region on the leading edge 21L side and a region on the trailing edge 21T side of the blade (airfoil portion 21 ).

[0129] According to the configuration of (10), by appropriately adjusting the interval L between the grooves 33 , the range of collecting liquid phase water can be appropriately changed, so that it is easy to cope with differences in the distribution conditions of liquid phase water in the blade (airfoil portion 21 ).

[0130] (11) In some embodiments, in any of the structures (7) to (10) above, in at least one of the plurality of grooves 33 , the width W of the groove 33 may be different between the leading edge 21L region and the trailing edge 21T region of the blade (airfoil portion 21 ).

[0131] According to the configuration of (11) above, by appropriately adjusting the width W of the groove 33 , the range of collecting liquid phase water can be appropriately changed, so that it is easy to cope with differences in the distribution conditions of liquid phase water in the blade (airfoil portion 21 ).

[0132] (12) A steam turbine 1 according to at least one embodiment of the present invention includes a steam turbine blade (stationary blade 9 ) having any one of the structures described in (1) to (11).

[0133] According to the configuration of (12), the cost for providing the through-holes 27 in the relatively large blades (stationary blades 9 ) can be reduced, and liquid phase water adhering to the surfaces of the blades (stationary blades 9 ) or the liquid phase guide members 30 can be effectively removed.

[0134] (13) A method for manufacturing a steam turbine blade according to at least one embodiment of the present invention is a method for manufacturing a steam turbine blade, comprising the following steps: a step S20 of forming a recess 23 on the surface of the blade (airfoil 21); a step S10 of forming a through hole 27 connected to the internal space 25 of the blade (airfoil 21) at a position closer to the trailing edge 21T side of the blade (airfoil 21) than the recess 23; and a step S30 of inserting and fixing a liquid phase guide component 30 having a surface having recesses and projections (convex portions 31 and grooves 33 or hydrophilic processed surfaces 34) for guiding liquid phase water to the trailing edge 21T side of the blade or coated with a hydrophilic coating 35, into the recess 23.

[0135] According to the method of (13), liquid phase water can be guided to the through hole 27 by the liquid phase guide member 30, so the range for providing the through hole 27 can be reduced. Thus, it is possible to provide a blade (stationary blade 9) that can effectively remove liquid phase water adhering to the surface of the blade (stationary blade 9) or the liquid phase guide member 30 while suppressing the cost for providing the through hole 27 on a relatively large blade (stationary blade 9).

[0136] Explanation of symbols

[0137] 1-steam turbine, 9-fixed blade, 21-airfoil, 21L-leading edge, 21T-trailing edge, 23-recess, 23A-first recess, 23B-second recess, 24-wing wall, 25-inner space, 27-through hole, 28-guide groove, 30, 30A, 30B, 30C-liquid phase guide component, 31-convex portion, 33-groove, 34-hydrophilic processed surface, 35-hydrophilic coating, 301-first liquid phase guide component, 302-second liquid phase guide component.

Claims

1. A steam turbine blade, comprising: A concave portion, formed on the surface of the blade; a liquid phase guide member, which is inserted into and fixed to the recessed portion and has a surface formed with recesses and projections for guiding liquid phase water to the trailing edge side of the blade or is coated with a hydrophilic coating; and The through hole is used to introduce the liquid phase water guided by the liquid phase guide member into the inner space of the blade.

2. The steam turbine blade according to claim 1, wherein: The height of the convex portion of the concavoconvex in the blade thickness direction or the height of the surface of the liquid phase guide member coated with the hydrophilic coating in the blade thickness direction is the same as the height of the blade surface in the blade thickness direction.

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

4. The steam turbine blade according to claim 1 or 2, wherein: The region where the projections and recesses are formed or the region where the hydrophilic coating is applied is a partial region in the blade height direction of the liquid phase guide member.

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

6. The steam turbine blade according to claim 5, wherein: A partial region of the first liquid-phase guide member overlaps a partial region of the second liquid-phase guide member in the blade height direction.

7. The steam turbine blade according to claim 1 or 2, wherein: The projections and depressions are formed by a plurality of grooves extending from the leading edge toward the trailing edge of the blade.

8. The steam turbine blade according to claim 7, wherein: At least one of the plurality of grooves is formed in a straight line shape when viewed in the blade thickness direction.

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

10. The steam turbine blade according to claim 7, wherein: Among the plurality of grooves, intervals between two adjacent grooves in the blade height direction are different between a region on the leading edge side and a region on the trailing edge side of the blade.

11. The steam turbine blade according to claim 7, wherein: In at least one of the plurality of grooves, a width of the groove is different between a region on the leading edge side and a region on the trailing edge side of the blade. 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 the following steps: The step of forming a recess on the surface of the blade; A step of 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 recessed portion; and A step of inserting and fixing a liquid phase guide member having concavities and convexities formed on the surface for guiding liquid phase water to the trailing edge side of the blade or coated with a hydrophilic coating into the concave portion.

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