Patent Grant
11840938
The present disclosure relates to a steam turbine stator vane, a steam turbine including the steam turbine stator vane, and a production method for the steam turbine stator vane.
In the vicinity of a last stage of a steam turbine, the wetness of a steam flow is not less than 8%. Water droplets generated from the wet steam flow cause a moisture loss, decreasing turbine efficiency. Further, the water droplets generated from the wet steam flow adhere to the surface of the stator vane, forming a water film. The above-described water film becomes a water film flow on the surface of the stator vane, flows to a trailing edge side of the stator vane, and is scattered at the trailing edge of the stator vane, forming coarse water droplets. Collision of the above-described coarse water droplets against a rotor blade rotating at high speed is one of major causes of triggering erosion of the rotor blade.
In order to prevent the erosion and the moisture loss of the steam turbine, removing a liquid (water droplets) adhering to the surface of the stator vane is effective. Conventionally, in order to remove a liquid adhering to the surface of a stator vane, a groove and a slit are formed in the surface of the stator vane (see Patent Documents 1, 2). The liquid adhering to the surface of the stator vane is sent in the groove and the slit, and is discharged from the groove and the slit to the outside of a system. Patent Document 1 discloses forming one or a plurality of grooves in the surface of the stator vane. The groove described in Patent Document 1 extends toward the radial direction of a steam turbine over one end portion to another end portion of the stator vane in the longitudinal direction. Patent Document 2 discloses forming, in the surface of a hollow stator vane internally including a cavity, one or a plurality of slits communicating with the cavity.
In order to improve removal efficiency of the liquid adhering to the surface of the stator vane, it is considered that two of the grooves described in Patent Document 1 are disposed in parallel in the surface of the stator vane along the height direction. However, due to low removal efficiency of the above-described grooves themselves, a removal amount of the liquid is small even if the above-described two grooves are disposed in parallel, which may be unable to improve removal efficiency of the liquid.
Further, in order to improve removal efficiency of the above-described liquid, it is considered that two of the slits described in Patent Document 2 are disposed in parallel in the surface of the stator vane along the height direction. In this case, due to a pressure difference between the first slit disposed upstream in the above-described axial direction and the second slit disposed downstream in the above-described axial direction, the liquid sucked from the first slit to the cavity may spout (flow back) from the second slit having a lower pressure than the first slit. Thus, it is impossible to increase the removal amount of the liquid, which may be unable to improve removal efficiency of the liquid. In order to prevent the backflow of the liquid, if the width of the slit is increased to improve a suction pressure of the slit, the amount of drive steam leaking to the cavity through the slit increases, which may decrease performance of the steam turbine.
In view of the above issues, an object of at least one embodiment of the present invention is to provide a steam turbine stator vane capable of preventing the decrease in performance of the steam turbine as well as improving removal efficiency of the liquid adhering to the surface of the stator vane, and a steam turbine including the steam turbine stator vane.
(1) A steam turbine stator vane according to at least one embodiment of the present invention includes a vane body portion which has a vane surface including a pressure surface and a suction surface, a moisture removal channel disposed in the above-described vane body portion, at least one slit opening to the above-described vane surface to communicate with the above-described moisture removal channel, and extending along a height direction from a base end portion toward a tip end portion of the above-described vane body portion, and at least one groove portion disposed in the above-described vane surface and extending from the above-described base end portion along the above-described height direction, at least a part of the at least one groove portion overlapping the above-described at least one slit along the above-described height direction.
With the above configuration (1), the steam turbine stator vane includes the slit and the groove portion disposed in the vane surface which is the surface of the stator vane, and the slit and the groove portion overlap at least partially along the height direction. Thus, it is possible to remove a liquid collected in the vane surface by a section (upstream drainage section) of the slit and the groove portion disposed upstream of the vane surface. Further, it is possible to remove a liquid collected downstream of the upstream drainage section in the vane surface, by a section (downstream drainage section) of the slit and the groove portion disposed downstream of the vane surface. That is, the above-described steam turbine stator vane can remove the liquid adhering to the vane surface, by the groove portion and the slit having higher removal efficiency of the liquid than the groove portion. Thus, it is possible to improve the removal efficiency of the liquid adhering to the vane surface.
Further, since one of the upstream drainage section or the downstream drainage section is the groove portion that does not communicate with the moisture removal channel, the above-described steam turbine stator vane can reduce the amount of drive steam leaking to the moisture removal channel through the slit, as compared with a configuration, where two slits overlapping each other along the height direction are disposed in the vane surface, as in a steam turbine stator vane according to a comparative example. Further, unlike the configuration, where the two slits overlapping each other along the height direction are disposed in the vane surface, as in the steam turbine stator vane according to the comparative example, the above-described steam turbine stator vane is free from the risk that the liquid flows back from the moisture removal channel via the slit, and thus a slit width need not be increased to improve a suction pressure of the slit. By suppressing the suction pressure of the slit, it is possible to further reduce the amount of the drive steam leaking to the moisture removal channel through the slit. Thus, the above-described steam turbine stator vane can reduce the amount of the drive steam leaking to the moisture removal channel through the slit, making it possible to prevent a decrease in performance of the steam turbine.
(2) In some embodiments, in the steam turbine stator vane according to the above configuration (1), the above-described at least one groove portion is configured to be inclined to a side of a trailing edge from the above-described tip end portion toward the above-described base end portion.
With the above configuration (2), since the at least one groove portion is configured to be inclined to the side of the trailing edge from the tip end portion toward the base end portion, the liquid stored in the groove portion is pushed by the flow of the steam flowing through in the steam turbine and flows toward the base end portion which is a discharge side of the liquid. Thus, the above-described groove portion can improve removal efficiency of the liquid stored in the groove portion.
(3) In some embodiments, in the steam turbine stator vane according to the above configuration (1) or (2), the above-described at least one slit includes a plurality of slits disposed separately from each other in the above-described height direction.
With the above configuration (3), since the plurality of slits are disposed separately from each other in the height direction, as compared with a case where the single slit extends along the height direction, it is possible to improve strength of the steam turbine stator vane in the vicinity of the slit. Improving the strength of the steam turbine stator vane in the vicinity of the slit, it is possible to reduce the thickness of the steam turbine stator vane, and thus to reduce a production cost of the steam turbine stator vane.
(4) In some embodiments, the steam turbine stator vane according to the above configuration (3) further includes a recess which is disposed in the above-described vane surface and to which the above-described plurality of slits open.
With the above configuration (4), since the plurality of slits disposed separately from each other open to the recess disposed in the vane surface, the liquid adhering to the vane surface is stored in the recess. Thus, the steam turbine stator vane including the above-described recess can prevent the liquid adhering to the vane surface from flowing downstream of the slits in the vane surface through the slits. Thus, the steam turbine stator vane including the above-described recess can improve removal efficiency of the liquid adhering to the vane surface.
(5) In some embodiments, in the steam turbine stator vane according to anyone of the above configurations (1) to (4), the above-described at least one slit is disposed between the above-described at least one groove portion and a leading edge.
With the above configuration (5), it is possible to remove the liquid that cannot be removed from the vane surface by the slit or the liquid adhering between the slit and the trailing edge on the vane surface, by the groove portion disposed between the slit and the trailing edge on the vane surface.
(6) In some embodiments, in the steam turbine stator vane according to anyone of the above configurations (1) to (4), the above-described at least one slit is disposed between the above-described at least one groove portion and a trailing edge.
With the above configuration (6), it is possible to remove the liquid that cannot be removed from the vane surface by the groove portion or the liquid adhering between the groove portion and the trailing edge on the vane surface, by the slit disposed between the groove portion and the trailing edge on the vane surface. The groove portion can reduce the amount of the liquid reaching the slit, and the slit has higher removal efficiency of the liquid adhering to the vane surface than the groove portion, making it possible to remove the liquid reaching the slit. Thus, with the above configuration, by disposing the slit between the groove portion and the trailing edge, it is possible to effectively remove the liquid adhering to the vane surface.
(7) In some embodiments, in the steam turbine stator vane according to any one of the above configurations (1) to (6), the above-described vane body portion includes a curved plate encompassing the above-described moisture removal channel and configured such that a difference between a maximum value and a minimum value of a thickness of the above-described curved plate falls within 40% of an average value of the above-described thickness.
With the above configuration (7), by equalizing the thickness of the curved plate, it is possible to reduce a material cost of the curved plate by cutting wasteful consumption of a material forming the curved plate, and thus to reduce the production cost of the stator vane.
(8) In some embodiments, in the steam turbine stator vane according to the above configuration (7), the above-described curved plate includes a pressure surface-side curved plate which has a surface including at least a part of the above-described pressure surface, and a suction surface-side curved plate which has a surface including at least a part of the above-described suction surface, and one of the above-described at least one slit or the above-described at least one groove portion is configured to include a joint where one end portion of the above-described pressure surface-side curved plate and one end portion of the above-described suction surface-side curved plate are joined by welding.
With the above configuration (8), one of the slit or the groove portion includes the joint where the one end portion of the pressure surface-side curved plate and the one end portion of the suction surface-side curved plate are joined by welding. That is, the shape of one of the slit or the groove portion is formed, when the curved plate is formed by welding the one end portion of the pressure surface-side curved plate and the one end portion of the suction surface-side curved plate. With the above configuration, since additional processing such as cutting is not needed to form one of the slit or the groove portion, it is possible to reduce a processing cost, and thus to reduce the production cost of the stator vane. Further, with the above configuration, since one of the slit or the groove portion can be formed without processing such as cutting, it is possible to prevent a decrease in strength in the vicinity of one of the slit or the groove portion.
(9) In some embodiments, in the steam turbine stator vane according to the above configuration (8), the above-described vane body portion further includes a trailing edge portion disposed between the above-described joint and a trailing edge, the trailing edge portion having a trailing edge-side pressure surface connected to the above-described trailing edge and a trailing edge-side wall surface extending from a front end portion on the above-described trailing edge-side pressure surface along a direction intersecting with the above-described trailing edge-side pressure surface, and the above-described at least one groove portion includes the above-described joint, and a part of the above-described at least one groove portion is defined by the above-described trailing edge-side wall surface.
With the above configuration (9), the at least one groove portion includes the joint, and a part of the at least one groove portion is defined by the trailing edge-side wall surface. That is, the shape of the groove portion is formed as a part of the trailing edge-side wall surface of the trailing edge portion, when the curved plate is formed by welding. Since a part of the above-described groove portion is defined by the trailing edge-side wall surface extending along the direction intersecting with the trailing edge-side pressure surface, it is possible to effectively prevent the liquid adhering to the vane surface from flowing toward the trailing edge-side pressure surface from the trailing edge-side wall surface.
(10) In some embodiments, in the steam turbine stator vane according to the above configuration (8), the above-described vane body portion further includes a trailing edge portion disposed between the above-described joint and a trailing edge, the trailing edge portion having a trailing edge-side pressure surface connected to the above-described trailing edge and a trailing edge-side wall surface extending from a front end portion on the above-described trailing edge-side pressure surface along a direction intersecting with the above-described trailing edge-side pressure surface, and the above-described at least one slit includes the above-described joint, and a part of the above-described at least one slit is defined by the above-described trailing edge-side wall surface.
With the above configuration (10), the at least one slit includes the joint, and apart of the slit is defined by the trailing edge-side wall surface. That is, the shape of the slit is formed as a part of the trailing edge-side wall surface of the trailing edge portion, when the curved plate is formed by welding. Since a part of the above-described slit is defined by the trailing edge-side wall surface extending along the direction intersecting with the trailing edge-side pressure surface, the liquid adhering to the vane surface is removed from the vane surface by the slit in the trailing edge-side wall surface. Thus, with the above configuration, it is possible to effectively prevent the liquid adhering to the vane surface from flowing toward the trailing edge-side pressure surface from the trailing edge-side wall surface.
(11) In some embodiments, in the steam turbine stator vane according to the above configuration (8), the above-described suction surface-side curved plate includes an extension portion extending from a trailing edge toward a leading edge, the extension portion having a surface including at least a part of the above-described pressure surface, the above-described one end portion of the above-described suction surface-side curved plate includes a front end portion of the above-described extension portion located on a side of the leading edge, and the above-described at least one groove portion includes the above-described joint, and a part of the above-described at least one groove portion is defined by an end surface at the above-described front end portion of the above-described extension portion.
With the above configuration (11), the at least one groove portion includes the joint, and a part of the at least one groove portion is defined by the end surface at the front end portion of the extension portion. That is, the shape of the groove portion is formed as a part of the end surface at the front end portion of the extension portion, when the curved plate is formed by welding the one end portion of the pressure surface-side curved plate and the above-described front end portion. Since a part of the above-described groove portion is defined by the end surface at the front end portion of the extension portion located on the side of the leading edge, it is possible to effectively prevent the liquid adhering to the end surface from flowing toward the pressure surface of the extension portion.
(12) A steam turbine according to at least one embodiment of the present invention includes the steam turbine stator vane according to any one of the above configurations (1) to (11), an annular member for supporting the above-described steam turbine stator vane, and a cavity disposed in the above-described annular member and configured to receive a liquid from each of the above-described moisture removal channel and the above-described at least one groove portion in the above-described vane body portion.
With the above configuration (12), since the steam turbine includes the cavity disposed in the annular member and configured to receive the liquid from each of the moisture removal channel and the at least one groove portion in the vane body portion, it is possible to store, in the cavity, the liquid removed from the vane surface by the slit and the groove portion. Storing, in the cavity, the liquid removed from the vane surface by the slit and the groove portion, it is possible to prevent that the liquid accumulates in the slit and the moisture removal channel in the vane body portion, and removal efficiency of the liquid adhering to the vane surface by the slit and the groove portion is decreased. Thus, the above-described steam turbine can effectively remove the liquid adhering to the vane surface by the slit and the groove portion.
(13) A production method for a steam turbine stator vane according to at least one embodiment of the present invention includes a slit forming step of forming at least one slit that opens to a vane surface of a vane body portion, which has the above-described vane surface including a pressure surface and a suction surface, to communicate with a moisture removal channel disposed in the above-described vane body portion, and extends along a height direction from a base end portion toward a tip end portion of the above-described vane body portion, and a groove portion forming step of forming at least one groove portion extending from the above-described base end portion in the above-described vane surface along the above-described height direction, at least a part of the at least one groove portion overlapping the above-described at least one slit along the above-described height direction.
With the above method (13), the production method for the steam turbine stator vane includes the slit forming step of forming the at least one slit, and the groove portion forming step of forming the at least one groove portion. The steam turbine stator vane produced by the production method for the steam turbine stator vane includes the slit and the groove portion disposed in the vane surface which is the surface of the stator vane, and the slit and the groove portion overlap at least partially along the height direction. Thus, the steam turbine stator vane produced by the production method for the steam turbine stator vane can improve removal efficiency of the liquid adhering to the vane surface and can prevent the decrease in performance of the steam turbine.
According to at least one embodiment of the present invention, provided are a steam turbine stator vane capable of preventing a decrease in performance of a steam turbine as well as improving removal efficiency of a liquid adhering to the surface of a stator vane, and a steam turbine including the steam turbine stator vane.
Some embodiments of the present invention will be described below with reference to the accompanying drawings. It is intended, however, that unless particularly identified, dimensions, materials, shapes, relative positions and the like of components described or shown in the drawings as the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention.
For instance, an expression of relative or absolute arrangement such as“in a direction”, “along a direction”, “parallel”, “orthogonal”, “centered”, “concentric” and “coaxial” shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function.
For instance, an expression of an equal state such as “same”, “equal”, and “uniform” shall not be construed as indicating only the state in which the feature is strictly equal, but also includes a state in which there is a tolerance or a difference that can still achieve the same function.
Further, for instance, an expression of a shape such as a rectangular shape or a tubular shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved.
On the other hand, the expressions “comprising”, “including” or “having” one constitutional element is not an exclusive expression that excludes the presence of other constitutional elements.
The same configurations are indicated by the same reference characters and may not be described again in detail.
As shown in
The annular member 13 defines an inner space 15 with the rotor 11. The annular member 13 and the stator vane 3 remain still without being linked to rotations of the rotor 11 and the rotor blade 12. The stator vane 3 extends along the radial direction (a direction orthogonal to the axis LA of the steam turbine 1) so as to traverse the inner space 15 from the annular member 13 toward the rotor 11. The rotor blade 12 extends along the radial direction so as to traverse the inner space 15 from the rotor 11 toward the annular member 13.
As shown in
In the illustrated embodiment, as shown in
The steam introduced to the inner space 15 mainly flows along the axial direction (a direction in which the axis LA of the steam turbine 1 extends). Hereinafter, upstream of the steam flow direction may simply be referred to as “upstream”, and downstream of the steam flow direction may simply be referred to as “downstream”.
With the steam flowing through the inner space 15 along the axial direction being a working fluid, the steam turbine 1 is configured to convert energy of the working fluid into rotational energy of the rotor 11. In the illustrated embodiment, provided that the combination of a vane row of the stator vanes 3 and a blade row of the rotor blades 12 is one stage, the steam turbine 1 includes a plurality of stages. The stator vanes 3 of each stage are disposed at predetermined intervals along the circumferential direction. The rotor blades 12 of each stage are disposed at predetermined intervals along the circumferential direction of the rotor 11. The stator vanes 3 of each stage rectify steam when the steam passes between the stator vanes 3 of each stage, and upon reception of the steam rectified by the stator vanes 3, the rotor blades 12 of each stage convert a force received from the steam into a rotational force to rotate the rotor 11. By the rotation of the rotor 11, a generator (not shown) mechanically connected to the rotor 11 is driven.
As shown in
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The stator vane 3 is disposed in a region 15A of the inner space 15 where a wet steam flow flows. In a certain embodiment, the region 15A is a region that satisfies a condition where the wetness of the steam flow is not less than 5% during the operation of the steam turbine 1. The vane body portion 4 is disposed such that the leading edge 43 is located upstream and the trailing edge 44 is located downstream in the steam flow direction. The pressure surface 45 is disposed to intersect with the steam flow direction so as to receive steam. Moisture in the wet steam flow adheres to the vane surface 47 (the pressure surface 45 and the suction surface 46) as water droplets (liquid).
As shown in
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The liquid W adhering between the leading edge 43 and the slit 7 in the vane surface 47 is sucked to the moisture removal channel 5 via the slit 7 by a differential pressure between the moisture removal channel 5 and the section 15B of the region 15A facing the vane surface 47. The liquid W sucked to the moisture removal channel 5 is sucked to the cavity 24 via the first communication hole 131 by a differential pressure between the moisture removal channel 5 and the cavity 24.
The liquid W adhering between the leading edge 43 and the groove portion 8 in the vane surface 47 is pushed by the flow of the steam flowing through the region 15A and enters the groove portion 8. The liquid W entering the groove portion 8 is sucked to the cavity 24 via the second communication hole 132 by a differential pressure between the groove portion 8 and the cavity 24.
The liquid W stored in the cavity 24 is discharged to the exhaust hood 17 via the third communication hole 133 by a differential pressure between the cavity 24 and the exhaust hood 17. In some other embodiments, the liquid W may be discharged to the outside of the steam turbine 1, or it may be configured such that the liquid W is sucked by a suction device (not shown) such as a suction pump.
In the embodiment shown in
In the embodiment shown in
In some other embodiments, each of the slit 7 and the groove portion 8 may be disposed between the leading edge 43 and the center of the pressure surface 45 or in the suction surface 46. However, since liquid (water film flow) is collected on the side of the trailing edge 44 in the pressure surface 45, each of the slit 7 and the groove portion 8 is preferably disposed in the pressure surface 45 relative to the suction surface 46 and is preferably disposed near the trailing edge 44 in the pressure surface 45. Further, the groove portion 8 may be disposed between the slit 7 and the trailing edge 44.
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As described above, for example, as shown in
In the illustrated embodiment, as shown in
With the above configuration, the stator vane 3 includes the slit 7 and the groove portion 8 disposed in the vane surface 47 which is the surface of the stator vane 3, and the slit 7 and the groove portion 8 overlap at least partially along the height direction. Thus, it is possible to remove the liquid W collected in the vane surface 47 by a section (upstream drainage section) of the slit 7 and the groove portion 8 disposed upstream (the side of the leading edge 43) of the vane surface 47. Further, it is possible to remove the liquid W collected downstream of the above-described upstream drainage section in the vane surface 47, by a section (downstream drainage section) of the slit 7 and the groove portion 8 disposed downstream (the side of the trailing edge 44) of the vane surface 47. That is, the stator vane 3 can remove the liquid W adhering to the vane surface 47, by the groove portion 8 and the slit 7 having higher removal efficiency of the liquid W than the groove portion 8. Thus, it is possible to improve the removal efficiency of the liquid W adhering to the vane surface 47.
Further, since one of the above-described upstream drainage section or the above-described downstream drainage section is the groove portion 8 that does not communicate with the moisture removal channel 5, the stator vane 3 can reduce the amount of the drive steam leaking to the moisture removal channel 5 through the slit, as compared with the configuration, where the two slits (the slit 7, the second slit 70) overlapping each other along the height direction are disposed in the vane surface 47, as in the stator vane 30 according to the comparative example. Further, unlike the configuration, where the two slits overlapping each other along the height direction are disposed in the vane surface 47, as in the stator vane 30 according to the comparative example, the stator vane 3 is free from the risk that the liquid W flows back from the moisture removal channel 5 via the slit 7, and thus the slit width need not be increased to improve a suction pressure of the slit 7. By suppressing the suction pressure of the slit 7, it is possible to further reduce the amount of the drive steam leaking to the moisture removal channel 5 through the slit 7. Thus, the stator vane 3 can reduce the amount of the drive steam leaking to the moisture removal channel 5 through the slit 7, making it possible to prevent the decrease in performance of the steam turbine 1.
In some embodiments, for example, as shown in
In some embodiments, for example, as shown in
With the above configuration, since the plurality of slits 7B are disposed separately from each other in the height direction, as compared with a case where the single slit 7A extends along the height direction, it is possible to improve strength of the stator vane 3 in the vicinity of the slit 7. Improving the strength of the stator vane 3 in the vicinity of the slit 7, it is possible to reduce the thickness of the stator vane 3, and thus to reduce a production cost of the stator vane 3.
In some embodiments, for example, as shown in
In the embodiment shown in
With the above configuration, since the plurality of slits 7B disposed separately from each other open to the recess 9 disposed in the vane surface 47, the liquid W adhering to the vane surface 47 is pushed by the flow of the steam flowing through the region 15A, enters the recess 9, and is stored in the recess 9. Thus, the stator vane 3 including the recess 9 can prevent the liquid W adhering to the vane surface 47 from flowing downstream of the slits 7B in the vane surface 47 through the slits 7B. Thus, the stator vane 3 including the recess 9 can improve removal efficiency of the liquid W adhering to the vane surface 47.
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, as shown in
In some embodiments, the vane body portion 4 including the curved plate 6 described above is a sheet-metal part where the shape of the vane body portion 4 is formed by performing sheet-metal processing on at least one sheet metal. In this case, it is possible to form the vane body portion 4 including the curved plate 6 by performing sheet-metal processing (such as cutting, bending, and welding) on one or a plurality of sheet metals (such as metal plate materials each formed into a thin flat shape by rolling or the like). Thus, it is possible to reduce the material cost and a processing cost of the vane body portion 4. Thus, with the above configuration, since it is possible to reduce the material cost and the processing cost of the vane body portion 4, it is possible to reduce the production cost of the stator vane 3.
In some embodiments, as shown in
In the illustrated embodiment, as shown in
With the above configuration, one of the slit 7 or the groove portion 8 includes the joint WP where the one end portion 622 of the pressure surface-side curved plate 62 and the one end portion 632 of the suction surface-side curved plate 63 are joined by welding. That is, the shape of one of the slit 7 or the groove portion 8 is formed, when the curved plate 6 is formed by welding the one end portion 622 of the pressure surface-side curved plate 62 and the one end portion 632 of the suction surface-side curved plate 63. With the above configuration, since additional processing such as cutting is not needed to form one of the slit 7 or the groove portion 8, it is possible to reduce the processing cost, and thus to reduce the production cost of the stator vane 3. Further, with the above configuration, since one of the slit 7 or the groove portion 8 can be formed without processing such as cutting, it is possible to prevent a decrease in strength in the vicinity of one of the slit 7 or the groove portion 8.
In some embodiments, as shown in
In the embodiment shown in
In the embodiment shown in
In the embodiment shown in
In the embodiment shown in
With the above configuration, the at least one groove portion 8 includes the joint WP, and a part of the groove portion 8 is defined by the trailing edge-side wall surface 644. That is, the shape of the groove portion 8 is formed as a part of the trailing edge-side wall surface 644 of the trailing edge portion 64, when the curved plate 6 is formed by welding. Since a part of the above-described groove portion 8 is defined by the trailing edge-side wall surface 644 extending along the direction intersecting with the trailing edge-side pressure surface 642, it is possible to effectively prevent the liquid W adhering to the vane surface 47 from flowing toward the trailing edge-side pressure surface 642 from the trailing edge-side wall surface 644.
In some embodiments, as shown in
In the embodiment shown in
The shape of the slit 7 is defined by the end surface 623 at the one end portion 622 of the pressure surface-side curved plate 62, the trailing edge-side wall surface 644, and the joint WP joining a section between the end surface 623 and the trailing edge-side wall surface 644. The groove portion 8 is disposed in the trailing edge-side pressure surface 642 of the thick portion 64A (trailing edge portion 64) located between the slit 7 and the trailing edge 44, and has a U-shaped cross-sectional shape. By thus disposing the groove portion 8 in the trailing edge portion 64 located between the slit 7 and the trailing edge 44, as compared with a case where the groove portion 8 is disposed in the pressure surface-side curved plate 62 located between the slit 7 and the leading edge 43, it is possible to improve removal efficiency of the liquid adhering to the vane surface 47. Further, the process of forming the groove portion 8 in the trailing edge portion 64 can be performed more easily than the process of forming the groove portion 8 in the pressure surface-side curved plate 62. Furthermore, with the configuration where the groove portion 8 is not disposed in the pressure surface-side curved plate 62, it is possible to reduce the thickness of the pressure surface-side curved plate 62 (curved plate 6).
Moreover, setting the joint WP on the trailing edge-side wall surface 644 to a section 644A spaced apart from the front end portion 643 toward the side of the suction surface 46, it is possible to form the above-described recess 9 by a section 644B of the trailing edge-side wall surface 644 between the above-described section 644A and the front end portion 643, and the surface 621 of the pressure surface-side curved plate 62. That is, the shape of the recess 9 is formed as a part of the trailing edge-side wall surface 644 of the trailing edge portion 64, when the curved plate 6 is formed by welding.
With the above configuration, the at least one slit 7 includes the joint WP, and a part of the slit 7 is defined by the trailing edge-side wall surface 644. That is, the shape of the slit 7 is formed as a part of the trailing edge-side wall surface 644 of the trailing edge portion 64, when the curved plate 6 is formed by welding. Since a part of the above-described slit 7 is defined by the trailing edge-side wall surface 644 extending along the direction intersecting with the trailing edge-side pressure surface 642, the liquid W adhering to the vane surface 47 is removed from the vane surface 47 by the slit 7 in the trailing edge-side wall surface 644. Thus, with the above configuration, it is possible to effectively prevent the liquid W adhering to the vane surface 47 from flowing toward the trailing edge-side pressure surface 642 from the trailing edge-side wall surface 644.
In some embodiments, as shown in
In the embodiment shown in
With the above configuration, the at least one groove portion 8 includes the joint WP and a part of the groove portion 8 is defined by the end surface 653 at the front end portion 652 of the extension portion 65. That is, the shape of the groove portion 8 is formed as a part of the end surface 653 at the front end portion 652 of the extension portion 65, when the curved plate 6 is formed by welding the one end portion 622 of the pressure surface-side curved plate 62 and the front end portion 652. Since a part of the above-described groove portion 8 is defined by the end surface 653 at the front end portion 652 of the extension portion 65 located on the side of the leading edge 43, it is possible to effectively prevent the liquid W adhering to the end surface 653 from flowing toward the surface 651 (pressure surface) of the extension portion 65.
As shown in
With the above configuration, since the steam turbine 1 includes the cavity 24 disposed in the annular member 13 and configured to receive the liquid from each of the moisture removal channel 5 and the at least one groove portion 8 in the vane body portion 4, it is possible to store, in the cavity 24, the liquid W removed from the vane surface 47 by the slit 7 and the groove portion 8. Storing, in the cavity 24, the liquid W removed from the vane surface 47 by the slit 7 and the groove portion 8, it is possible to prevent that the liquid W accumulates in the slit 7 and the moisture removal channel 5 in the vane body portion 4, and removal efficiency of the liquid W adhering to the vane surface 47 by the slit 7 and the groove portion 8 is decreased. Thus, the above-described steam turbine 1 can effectively remove the liquid W adhering to the vane surface 47 by the slit 7 and the groove portion 8.
As shown in
The slit forming step S102 includes forming the at least one slit 7 (7A, 7B) that opens to the vane surface 47 of the vane body portion 4, which has the vane surface 47 including the pressure surface 45 and the suction surface 46, to communicate with the moisture removal channel 5 disposed in the vane body portion 4, and extends along the height direction from the base end portion 41 toward the tip end portion 42 of the vane body portion 4.
The groove portion forming step S103 includes forming the at least one groove portion 8 which extends from the base end portion 41 along the height direction in the vane surface 47 and at least a part of which overlaps the at least one slit 7 along the height direction.
Each of the slit 7 and the groove portion 8 may be formed by cutting, or the shape of each of the slit 7 and the groove portion 8 may be formed when the curved plate 6 is formed as described above.
With the above method, the production method 100 for the steam turbine stator vane includes the slit forming step S102 of forming the at least one slit 7, and the groove portion forming step S103 of forming the at least one groove portion 8. The stator vane 3 produced by the production method 100 for the steam turbine stator vane includes the slit 7 and the groove portion 8 disposed in the vane surface 47 which is the surface of the stator vane 3, and the slit 7 and the groove portion 8 overlap at least partially along the height direction. Thus, the stator vane 3 produced by the production method 100 for the steam turbine stator vane can improve removal efficiency of the liquid W adhering to the vane surface 47 and can prevent the decrease in performance of the steam turbine 1.
The present invention is not limited to the above-described embodiments, and also includes an embodiment obtained by modifying the above-described embodiments and an embodiment obtained by combining these embodiments as appropriate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-108080 | Jun 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/018395 | 5/1/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/250596 | 12/17/2020 | WO | A |
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| 20110135447 | Guo | Jun 2011 | A1 |
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| 20140079556 | Ishibashi | Mar 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| S63-117104 | May 1988 | JP |
| S63-280801 | Nov 1988 | JP |
| H02-064702 | May 1990 | JP |
| H03-026802 | Feb 1991 | JP |
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| Entry |
|---|
| International Search Report dated Jul. 14, 2020, counterpart Application No. PCT/JP2020/018395. |
| Notification of Transmittal of Translation of the International Preliminary Report on Patentability (Form PCT/IB/338) issued in counterpart International Application No. PCT/JP2020/018395 dated Dec. 23, 2021, with Forms PCT/IB/373 and PCT/ISA/237. (14 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20220228510 A1 | Jul 2022 | US |
