JP5851876B2 - Turbine runner and turbine - Google Patents

Description

  The present invention relates to a turbine runner and a turbine used for a Francis type turbine, a pump turbine, and the like.

  Conventionally, a crown connected to a rotating shaft, a shroud (also referred to as a band) disposed away from the crown and coaxially with the crown, and a plurality of circumferentially disposed sheets between the crown and the shroud 2. Description of the Related Art A runner for a water turbine having a runner blade is known (see, for example, Patent Document 1). This kind of water turbine runner is rotated by the flow of working fluid acting on each runner blade. Therefore, in order to maximize the turbine efficiency, it is preferable that no rotational direction component is generated in the flow of the working fluid flowing out from the runner.

JP 2007-2783 A

  The direction of the working fluid flowing out of the runner depends on the shape of the runner blade. Therefore, at the design point, in order to prevent a rotational direction component from occurring in the flow of the working fluid flowing out from the runner, the accuracy of the shape of the runner blade, particularly the shape of the runner blade in the vicinity of the outlet in the flow direction of the working fluid, should be increased. Need to increase. However, increasing the shape accuracy of the runner blades increases the manufacturing cost.

  An object of the present invention is to provide a turbine runner and a turbine capable of maximizing the turbine efficiency with an inexpensive configuration.

  A runner for a turbine according to an aspect of the present invention is a runner for a turbine having a plurality of runner blades on which a working fluid acts, and the runner blades extend in the flow direction of the working fluid and a suction surface. A leading edge connecting the pressure surface and the suction surface at the upstream end of the working fluid, a trailing edge connecting the pressure surface and the suction surface at the downstream end of the working fluid, and a pressure surface side It has the 1st uneven | corrugated part provided in the uneven | corrugated shape in the vicinity of the rear edge part, and the 2nd uneven | corrugated part provided in the uneven | corrugated form in the vicinity of the rear edge part on the suction surface side.

  According to this configuration, the flow of the water along the pressure surface and the negative pressure surface is separated at the first uneven portion and the second uneven portion, respectively, and the pressure surface side and the negative surface are downstream of the first uneven portion and the second uneven portion. The peeling side is almost symmetrical on the pressure side. For this reason, even when the shape of the trailing edge portion is deviated from the design value, the flow of the service water that has passed through the runner can be made to flow with only the axial component having no rotational direction component, and the turbine efficiency Can be increased. Therefore, it is not necessary to accurately match the shape of the trailing edge with the design value, and the manufacturing cost of the runner can be suppressed. That is, the turbine efficiency can be maximized with an inexpensive configuration.

  In the water turbine runner according to another aspect of the present invention, the first uneven portion and the second uneven portion are provided symmetrically with respect to the camber line passing through the center of the runner blade.

  According to this configuration, the starting points of the flow separation on the pressure surface side and the suction surface side are the same, and the flow direction of the irrigation water at the runner blade outlet can be accurately matched to the design relative speed direction. .

  In the water turbine runner according to another aspect of the present invention, the first uneven portion and the second uneven portion may be provided in an asymmetric relationship with a camber line passing through the center of the runner blade.

  The asymmetric relationship with respect to the camber line is that the first uneven portion and the second uneven portion are provided at an asymmetric position with respect to the camber line, or the first uneven portion and the second uneven portion are the camber line. Even in this configuration including the asymmetric shape with respect to the pressure surface, the flow of water along the pressure surface and the suction surface peels off at the first uneven portion and the second uneven portion, respectively, and the first uneven portion and the first uneven portion 2 On the downstream side of the concavo-convex portion, the pressure surface side and the negative pressure surface side are in a state of starting peeling that is stable to each other (not easily affected by the downstream side). For this reason, even if the shape of the trailing edge portion is deviated from the design value, it is easy in terms of specifications to make the flow of the water that has passed through the runner only the axial component that does not have the rotational component. Therefore, the turbine efficiency can be improved. Therefore, it is not necessary to accurately match the shape of the trailing edge with the design value, and the manufacturing cost of the runner can be suppressed. That is, the turbine efficiency can be maximized with an inexpensive configuration.

  In the water turbine runner according to another aspect of the present invention, the rear edge is formed in a curved surface shape from the first starting point on the pressure surface side to the second starting point on the negative pressure surface side.

  According to this configuration, the flow loss downstream of the trailing edge is small. In addition, when the first concavo-convex portion and the second concavo-convex portion are provided on the runner blade having the curved rear edge, the effect of reducing the manufacturing cost is high.

  In the water turbine runner according to another aspect of the present invention, the first uneven portion and the second uneven portion are provided at the first start point and the second start point, respectively.

  According to this configuration, the force for rotating the runner due to the flow of the irrigation water efficiently acts on the pressure surface and the suction surface, and the separation of the flow due to the provision of the first uneven portion and the second uneven portion causes rotation of the runner. Can prevent adverse effects. In addition, since the starting point of the trailing edge is a point where the blade surface shape suddenly changes and the flow along the blade surface starts to be disturbed, the pressure surface can be obtained by providing the first uneven portion and the second uneven portion at the starting point. The flow on the side and the suction surface side can be in a favorable symmetrical peeling state.

  In the water turbine runner according to another aspect of the present invention, the first uneven portion and the second uneven portion are provided over the height direction of the runner blade.

  According to this configuration, the pressure surface side and the suction surface side can be almost symmetrically separated from each other at the entire outlet of the runner blade, and the turbine efficiency can be maximized.

  A water turbine according to an aspect of the present invention includes a rotating shaft and the turbine runner connected to the rotating shaft.

  According to this configuration, the turbine efficiency can be maximized with an inexpensive configuration.

  According to the present invention, the turbine efficiency can be maximized with an inexpensive configuration.

FIG. 1 is a schematic configuration diagram of a pump turbine having a turbine runner according to an embodiment of the present invention. FIG. 2 is a plan view of the runner as seen from the outlet channel side of FIG. FIG. 3 is a cross-sectional view showing the shape of the runner vane of FIG. 1 along the flow direction of the water. 4 is an enlarged view of the vicinity of the rear edge of FIG. FIG. 5 is a diagram for explaining the flow of water at the outlet of the runner vane. FIG. 6 is an enlarged view showing the configuration of the main part of the runner vane according to the first embodiment of the present invention, and shows the configuration in the vicinity of the rear edge along the length direction of the runner vane. FIG. 7 is an enlarged view showing the configuration of the main part of the runner vane according to the first embodiment of the present invention, and showing the configuration in the vicinity of the rear edge along the height direction of the runner vane. FIG. 8 is a perspective view showing a main configuration of a runner vane according to the second embodiment of the present invention. FIG. 9 is a diagram showing a modification of the present invention. 10 is a cross-sectional view of the groove of FIG. FIG. 11 is a diagram showing another modification of the present invention.

(First embodiment)
Hereinafter, a runner for a turbine according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a pump turbine having a turbine runner according to the present embodiment.

  The pump turbine according to the present embodiment is a so-called Francis-type pump turbine, and has a function as a pump that performs pumping and a function as a turbine that generates power. That is, the pump turbine 11 of FIG. 1 includes a rotating shaft 12 having a base end connected to a generator (not shown), and a runner (impeller) 13 that is fixed to the distal end of the rotating shaft 12 and rotates integrally. Have. In the following, for convenience, the direction of the axis L0 passing through the center of the rotating shaft 12 is defined as the vertical direction as shown in the figure, and the configuration of each part will be described according to this definition. The upper side is the base end side of the rotating shaft 12, and the lower side is the front end side.

  The pump turbine 11 can generate electric power with the generator by rotating the rotating shaft 12 with the rotation of the runner 13 by water. On the other hand, pumping can be performed by rotating the runner 13 via the rotating shaft 12 by this generator at night, for example. Hereinafter, the case where the pump turbine 11 is mainly used as a turbine will be described.

  The rotating shaft 12 is disposed along the vertical direction (up and down direction) and is rotatably supported by the casing 14 via a bearing 15. The runner 13 is fixed to the lower end portion of the rotating shaft 12 integrally with the rotating shaft 12, and rotates around the axis L 0 together with the rotating shaft 12.

  The runner 13 includes a crown 16, a shroud 17, a plurality of runner vanes 18, and a cone 19. The crown 16 has a disk shape centered on the axis L 0, and the center portion 16 a is fixed to the distal end portion of the rotating shaft 12 by the key 12 a. The shroud 17 has a curved ring shape centered on the axis L0. The end portions of the plurality of runner vanes 18 are fixed to both end surfaces so as to be sandwiched between the crown 16 and the shroud 17 and are arranged at equal intervals in the circumferential direction. The cone 19 has a conical shape in which the tip is narrowed about the axis L0, and is fixed to the center 16a of the crown 16 by a plurality of bolts 20. A rotation gap S1 is provided between the outer peripheral surface of the shroud 17 and the inner peripheral surface of the casing 14, and a rotation gap S2 is provided between the upper end surface of the crown 16 and the inner peripheral surface of the casing 14. Yes.

  The casing 14 forms an inlet channel 21 along the horizontal direction on the side of the runner 13, that is, in a direction perpendicular to the axis L 0, and exits along the vertical direction below the runner 13, ie, in the direction of the axis L 0. A flow path 22 is formed. Further, the casing 14 forms an internal flow path 23 between the runner vanes 18 from the inlet flow path 21 to the outlet flow path 22. Here, the inlet channel 21 functions as a water inlet into which the water flows into the runner 13, and the outlet channel 22 functions as a water outlet from which the water flows out from the runner 13.

  Although not shown, a spiral spiral casing is provided around the runner 13 so as to surround the runner 13. The water that has flowed through the spiral casing flows into the inlet flow channel 21 and then flows into the internal flow channel 23 from the entire outer periphery of the runner 13 in the radial direction. When this water passes through the internal flow path 23, a rotational force is applied to the runner vane 18 to rotate the runner 13. Thereby, the rotating shaft 12 rotates and can generate electric power. The water for rotating the runner 13 flows out from the internal flow path 23 to the outlet flow path 22.

  FIG. 2 is a plan view of the runner 13 as viewed from the outlet flow path 22 side, that is, a view of the runner 13 projected onto a plane perpendicular to the axis L0. FIG. 3 is a cross-sectional view of the runner vane 18 along the flow direction of the irrigation water. For example, the cross-sectional shape of the runner vane 18 near the intersection of the shroud 17 and the runner vane 18 (18a in FIG. 2). The runner vane 18 of the present embodiment has a characteristic configuration in the vicinity of the end (rear edge) on the outlet flow path 22 side, but is not shown in FIGS.

  As shown in FIG. 2, the runner 13 has six runner vanes 18 arranged at equal intervals in the circumferential direction, and rotates in the direction of arrow A due to the pressure of water flowing from the inlet channel 21 to the outlet channel 22. To do. As shown in FIG. 3, the runner vane 18 is provided at a pressure surface 31 and a negative pressure surface 32 extending in the flow direction of the irrigation water, and an inflow side end of the irrigation water, and a leading edge that connects the pressure surface 31 and the negative pressure surface 32. And a rear edge portion 34 that is provided at an end portion on the outflow side of the water and connects the pressure surface 31 and the negative pressure surface 32. The pressure surface 31 is a surface on which the pressure of the service water flowing in from the inlet channel 21 acts.

  The pressure surface 31 and the suction surface 32 are positioned symmetrically with respect to the camber line CL that passes through the center of the thickness t of the runner vane 18. Hereinafter, the direction along the camber line CL of the runner vane 18 is referred to as a length direction L (FIG. 3), and the direction from the inner surface of the crown 16 to the inner surface of the shroud 17 is referred to as a height direction H (FIG. 2). The front edge portion 33 and the rear edge portion 34 have a curved shape such as an arc or an ellipse, and the curvature of the surface of the runner vane 18 at the front edge portion 33 and the rear edge portion 34 increases rapidly, and the thickness t of the runner vane 18 increases. Decreases rapidly.

  4 is an enlarged view of the vicinity of the rear edge 34 of FIG. The boundary between the pressure surface 31 and the suction surface 32 and the trailing edge 34 is a starting point 35 where the arc or ellipse of the trailing edge 34 starts, and the trailing edge 34 starts from the starting point 35 on the pressure surface 31 side. A curved surface (in the figure, an ellipse) is formed from the side starting point 35. In FIG. 4, the rotational speed of the rotating runner 13 is represented by U, the relative speed of the water flowing out of the runner vane 18 as viewed from the rotating runner 13 is represented by V, and the absolute speed of the water flowing out of the runner vane 18 is represented by W.

  The relative speed V of the water flowing out of the runner vane 18 depends on the blade shape of the runner vane 18. In the present embodiment, at a design point where a predetermined flow rate flows from the inlet channel 21 to the outlet channel 22, the rotational speed component V1 of the rotational speed U of the runner 13 and the relative speed V of the water flowing out of the runner vane 18 (dotted line). The runner vanes 18 are configured so as to match the size of (). As a result, as shown in FIG. 4, the absolute speed W of the water that has passed through the runner 13 at the design point flows only in the axial direction (vertical direction) component without the rotational direction (horizontal direction) component. For this reason, the angular momentum of the water flowing in from the radially outer side of the runner 13 can be efficiently recovered as the rotational energy of the runner 13, and the turbine efficiency is maximized.

  By the way, the flow of irrigation water along the runner vanes 18 is greatly affected by the actual shape of the trailing edge 34. That is, as shown in FIG. 5B, if the trailing edge 34 is accurately formed as designed, the flows of water on the pressure surface 31 side and the suction surface 32 side of the trailing edge 34 are mutually Since it becomes substantially symmetrical, a desired relative velocity V along the blade shape of the runner vane 18 is obtained. The angle formed by the relative velocity V with respect to the horizontal line at this time is θb.

  However, due to manufacturing errors of the runner vanes 18 and the like, for example, as shown in FIG. 5A or 5C, the negative pressure surface 32 side or the pressure surface 31 side of the rear edge 34 is smaller than the design value indicated by the dotted line. If it is formed, or if it is formed larger than the design value (not shown), the flow of water on the pressure surface 31 side and the negative pressure surface 32 side of the rear edge 34 becomes strongly asymmetric with respect to each other. As a result, the relative speed becomes V ′ or V ″, and the flow is biased toward the pressure surface 31 side or the suction surface 32 side with respect to the design relative speed V, and a deviation occurs with respect to the design relative speed V. The angle θa formed by the relative speed V ′ with respect to the horizontal line is smaller than θb, and the angle θc formed by the relative speed V ″ with respect to the horizontal line is larger than θb. As a result, the irrigation water at the outlet of the runner vane 18 becomes a swirling flow having a rotational direction component, and the turbine efficiency decreases. Considering this point, in the first embodiment, the runner vane 18 is configured as follows.

  6 and 7 are enlarged views showing the main configuration of the runner vane 18 according to the first embodiment. 6 shows a configuration in the vicinity of the trailing edge portion along the length direction L of the runner vane 18, and FIG. 7 shows a configuration in the vicinity of the trailing edge portion in the height direction H. 7A shows the configuration on the pressure surface 31 side, and FIG. 7B shows the configuration on the suction surface 32 side. In FIG. 7, a straight line obtained by connecting the starting point 35 of the trailing edge 34 in the height direction H is defined as a starting point line 35a.

  As shown in FIGS. 6 and 7, a circular recess 40 having a predetermined depth is formed at the start point 35 of the rear edge 34 on the pressure surface 31 side of the runner vane 18 and the start point 35 of the rear edge 34 on the negative pressure surface 32 side. , 41 are provided at equal intervals over the height direction H. The concave portion 40 on the pressure surface 31 side and the concave portion 41 on the negative pressure surface 32 side have the same shape, and the concave portions 40 and 41 are provided symmetrically with respect to the camber line CL. Therefore, the surface shapes in the vicinity of the rear edge portion on the pressure surface 31 side and the suction surface 32 side are the same (symmetric). The recesses 40 and 41 may have a shape other than a circle such as an ellipse or a rectangle, and may be provided at unequal intervals in the height direction H. The areas of the recesses 40 and 41 may be constant over the thickness direction of the runner vanes 18 or may gradually decrease.

  By providing the recesses 40 and 41 at the starting point 35 of the trailing edge 34, the water flows S 1 and S 2 along the pressure surface 31 and the negative pressure surface 32 are separated at the recesses 40 and 41. That is, the turbulent flow is promoted by the recesses 40 and 41, and the water flows S1 and S2 on the pressure surface 31 side and the negative pressure surface 32 side are similarly disturbed. Thereby, on the downstream side of the recesses 40 and 41, a separation start state (turbulent flow) that is substantially symmetrical with each other on the pressure surface 31 side and the suction surface 32 side is obtained, and the deviation of the flow with respect to the flow of the design relative velocity V can be suppressed. . That is, the angle θ of the outlet of the runner vane 18 with respect to the horizontal line in the relative flow direction can be brought close to the designed angle θb (FIG. 5). As a result, even when the shape of the trailing edge portion 34 is deviated from the design value, it is possible to reduce the uneven flow of the flow toward the pressure surface 31 side and the suction surface 32 side of the water at the outlet of the runner vane 18, The turbine efficiency can be increased.

According to 1st Embodiment, there can exist the following effects.
(1) In the runner 13 having a plurality of runner vanes 18 on which the irrigation water acts, the pressure surface 31 and the negative pressure surface 32 in which the irrigation water extends in the flow direction, and the pressure surface 31 and the negative pressure surface 32 at the upstream end of the irrigation water. For the runner vane 18 having a front edge 33 for connecting the pressure surface 31 and a rear edge 34 for connecting the pressure surface 31 and the negative pressure surface 32 at the downstream end of the water supply, A recess 40 is provided at the start point 35, and a recess 41 is provided at the start point 35 of the trailing edge 34 on the suction surface 32 side. As a result, the water flows S1 and S2 along the pressure surface 31 and the suction surface 32 are separated at the recesses 40 and 41, respectively, and are substantially symmetrical with each other on the pressure surface 31 side and the suction surface 32 side downstream of the recesses 40 and 41. It will be in a peeling start state. For this reason, even if the shape of the trailing edge portion 34 is deviated from the design value, only the axial component that does not have the rotational direction component is used for the flow of the water that has passed through the runner 13 (the absolute velocity W in FIG. 4). The turbine efficiency can be improved. Therefore, it is not necessary to accurately match the shape of the trailing edge 34 to the design value, and the manufacturing cost of the runner 13 can be suppressed.

(2) The recess 40 and the recess 41 are provided at the starting point 35 of the rear edge 34 on the pressure surface 31 side and the suction surface 32 side, respectively. In other words, the recesses 40 and 41 are provided at substantially symmetrical positions with respect to the camber line CL. As a result, the starting points of separation of the flows S1 and S2 on the pressure surface 31 side and the suction surface 32 side are the same, and the flow direction of the water at the outlet of the runner vane 18 is made to coincide with the direction of the design relative speed V with high accuracy. be able to.

(3) Since the trailing edge 34 is formed in a curved surface from the starting point 35 on the pressure surface 31 side to the starting point 35 on the negative pressure surface 32 side, the flow loss downstream of the trailing edge 34 is small. Moreover, since the structure of the recessed parts 40 and 41 was applied to the runner vane 18 having the curved rear edge part 34, the effect of reducing the manufacturing cost is high. That is, if the trailing edge 34 has a curved surface shape, it is difficult to accurately match the shape of the trailing edge 34 with the design value, resulting in a significant increase in manufacturing cost. On the other hand, if the recesses 40 and 41 are provided at the starting point 35 of the rear edge portion 34, the influence of the shape of the rear edge portion 34 on the flow is reduced. In other words, the sensitivity of the rear edge portion 34 is reduced. It is not necessary to form the edge 34 with high accuracy.

(4) Concave portions 40 and 41 are provided at the start point 35 of the trailing edge 34 on the pressure surface 31 side and the negative pressure surface 32 side, and the pressure surface 31 and the negative pressure surface 32 have a smooth shape without irregularities. For this reason, the force which rotates runner 13 by flow of water S1 and S2 with respect to pressure surface 31 and negative pressure surface 32 acts efficiently, and exfoliation of flows S1 and S2 by providing crevice 40 and 41 is runner 13 Can be prevented from adversely affecting the rotation. In addition, since the start point 35 of the trailing edge 34 is a point where the blade surface shape suddenly changes and the flow along the blade surface starts to be disturbed, by providing the recesses 40 and 41 at the start point 35, the pressure surface 31 side And the flows S1 and S2 on the suction surface 32 side can be in a favorable symmetric peeling state.

(5) The plurality of recesses 40 and 41 are provided along the starting point line 35a where the starting point 35 of the rear edge 34 is provided. That is, since the plurality of recesses 40 and 41 are provided over the runner vane 18 in the height direction, the pressure surface 31 side and the suction surface 32 side are brought into a substantially symmetrical peeling start state in the entire outlet of the runner vane 18. Can improve the turbine efficiency to the maximum.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment in the shape near the rear edge of the runner vane 18. In the following, differences from the first embodiment will be mainly described.

  FIG. 8 is a perspective view showing a main configuration of the runner vane 18 according to the second embodiment. As shown in FIG. 8, at the start point 35 of the trailing edge 34 on the pressure surface 31 side and the negative pressure surface 32 side, convex portions 42 and 43 are extended in the height direction, respectively. The height of the protrusions 42 and 43 (the length of the runner vane 18 in the thickness direction) is constant over the height direction H of the runner vane 18. These convex portions 42 and 43 can be configured, for example, by welding a wire having a constant cross-sectional shape in the longitudinal direction to the starting point 35 on the pressure surface 31 side and the negative pressure surface 32 side.

  As described above, when the convex portions 42 and 43 are provided at the start points 35 on the pressure surface 31 side and the negative pressure surface 32 side, the water flows S1 and S2 are disturbed starting from the convex portions 42 and 43, and the convex portions 42 and 43 The downstream water flows S1 and S2 on the pressure surface 31 side and the negative pressure surface 32 side are in a peeling start state that is substantially symmetrical with each other. For this reason, as in the first embodiment, the flow of the water (absolute speed W) that has passed through the runner 13 does not have a rotational direction component even if the shape of the trailing edge 34 is not accurately matched to the design value. Only the direction component can be flowed, and the manufacturing cost of the runner 13 can be suppressed. If the convex portions 42 and 43 are provided by welding a wire, the convex portions 42 and 43 can be configured at low cost.

(Modification)
In the above embodiment, the concave portions 40 and 41 or the convex portions 42 and 43 are provided at the starting point 35 on the pressure surface 31 side and the negative pressure surface 32 side of the rear edge portion 34. An uneven portion may be provided in addition to the starting point 35. For example, you may make it provide an uneven | corrugated | grooved part in the flow direction upstream of the water from the starting point 35, or downstream. In this way, even if the uneven portion is deviated from the starting point 35, if the uneven portion is provided in the vicinity of the rear edge portion 34, the runner flow is caused to act on the pressure surface 31 and the negative pressure surface 32, so that the runner While applying a rotational force to 13, a peeling start state that is substantially symmetric can be generated at the outlet of the runner vane 18 on the pressure surface 31 side and the negative pressure surface 32 side. That is, when the uneven portion is separated from the vicinity of the start point 35 to the upstream side of the flow, the range in which the water is applied so as to apply the rotational force to the runner vane 18 is narrowed, and a sufficient rotational force cannot be applied to the runner 13. If the concavo-convex portion is in the vicinity of the starting point 35, the runner 13 can be provided with a sufficient rotational force. In this case, the concavo-convex portion is a portion in which the surface shape on the pressure surface 31 side and the negative pressure surface 32 side is formed in a concavo-convex shape by providing only a concave portion, only a convex portion, or both concave and convex portions. Say.

  In the above embodiment, the concave portions 40 and 41 or the convex portions 42 and 43 are provided at the starting point 35 (first starting point) on the pressure surface 31 side and the starting point 35 (second starting point) on the negative pressure surface 32 side of the trailing edge 34, respectively. However, the configuration of the first uneven portion provided in an uneven shape on the pressure surface 31 side of the runner vane 18 and the configuration of the second uneven portion provided in an uneven shape on the negative pressure surface 32 side are not limited to those described above. For example, in the above embodiment (FIG. 7), the plurality of recesses 40, 41 are provided over the height direction H of the runner vane 18, but these recesses 40, 41 are connected over a predetermined range (for example, the entire height direction H). It is good also as a groove. In the above-described embodiment (FIG. 8), one convex portion 42, 43 is provided on each of the pressure surface 31 side and the negative pressure surface 32 side. You may divide into parts. Not only the recesses 40 and 41 or the protrusions 42 and 43 but also the recesses 40 and 41 and the protrusions 42 and 43 may be provided on the pressure surface 31 side and the negative pressure surface 32 side, respectively. If it is possible to positively cause separation of the flow of water in the concavo-convex portion, the concavo-convex portion may be configured by increasing the surface roughness in the vicinity of the rear edge portion 34. That is, as long as the separation (turbulent flow) of the water flow S1 at the rear edge 34 on the pressure surface 31 side is promoted, the first uneven portion may have any configuration, and the water at the rear edge 34 on the negative pressure surface 32 side. As long as the separation (turbulent flow) of the flow S2 is promoted, the second uneven portion may have any configuration.

  As shown in FIG. 9, starting from a starting point 35 (starting point line 35a) on the pressure surface 31 side and a starting point 35 (starting line 35a) on the negative pressure surface 32 side of the trailing edge 34, grooves are respectively formed on the downstream side in the water flow direction. 44 and 45 may be provided. A plurality of grooves 44 and 45 are preferably provided at predetermined intervals in the height direction H of the runner vanes 18. The groove 44 and the groove 45 may be connected along the blade surface of the runner vane 18 as shown in FIG. 9, or may be divided from each other. Although not shown, the groove 44 and the groove 45 may be connected so as to penetrate the runner vane 18 in the thickness direction. FIG. 10 is a diagram illustrating an example of a cross-sectional shape of the grooves 44 and 45. As shown in FIG. 10A, the grooves 44 and 45 may be provided perpendicular to the surface of the rear edge 34 of the runner vane 18, and as shown in FIG. 10B, the rear edge 34. You may provide diagonally with respect to the surface. In the example of FIG. 10A, the grooves 44 and 45 can be easily formed. In the example of FIG. 10B, turbulence is likely to occur at the trailing edge 34.

  In the above embodiment (FIGS. 6 to 8), the recesses 40 and 41 and the protrusions 42 and 43 are provided in only one row over the height direction H of the runner vane 18, but a plurality of rows may be provided. For example, as shown in FIG. 11, the recesses 40 and 41 are provided along the starting point line 35a, and the recesses 40 and 41 are also provided on the rear edge 34 on the downstream side of the starting point line 35a. Also good. In this case, the recesses 40 and 41 in each row may be arranged on the same straight line in the length direction L, but the recesses 40 and 41 in each row are alternately shifted in the height direction H as shown in FIG. In other words, they may be arranged in a staggered manner.

  In the said embodiment (FIGS. 6-8), while providing the recessed part 40, the recessed part 41, the convex part 42, and the convex part 43 in the mutually symmetrical position with respect to the camber line CL, it was set as the mutually symmetrical shape, As long as the forms of peeling are equal to each other, they may not be in a symmetrical position or may not have a symmetrical shape. That is, if the relative speed of the water at the outlet of the runner vane 18 approaches the designed relative speed V (FIG. 5) by providing the uneven portions on the pressure surface 31 side and the negative pressure surface 32 side, the position of the uneven portion May be offset from each other and asymmetric with respect to the camber line CL, and the shape of the concavo-convex portions may be different from each other. And when making the position of an uneven part into an asymmetric position with respect to the camber line CL and providing this uneven part at the start point 35 of the rear edge part 34, the start point 35 on the pressure surface 31 side and the start point 35 on the negative pressure surface 32 side are: There is an asymmetric relationship with the camber line CL.

  In the above embodiment, the rear edge portion 34 has a curved shape such as an arc or an ellipse. However, by providing the uneven portion, the flow of water on the pressure surface 31 side and the negative pressure surface 32 side downstream of the uneven portion. Since S1 and S2 are in a peeling start state that is substantially symmetrical with each other, the trailing edge 34 may not be curved. In this case, for example, the rear edge portion 34 is formed in a flat surface at the tip, or formed at a pointed tip by each flat surface inclined from the start point 35 on the pressure surface 31 side and the negative pressure surface 32 side. (However, the tip may be rounded.)

  In the above embodiment, the concavo-convex portions (concave portions 40, 41, convex portions 42, 43) are provided over the entire height direction H of the runner vane 18, but the concavo-convex portions are provided only in a part of the height direction H. It may be. For example, an uneven portion may be provided only on the shroud 17 side, only on the crown 16 side, or only on the central portion in the height direction H of the runner vane 18.

  In the above embodiment, the number of runner vanes (runner blades) 18 is six. However, the number of runner vanes 18 and the vicinity of the rear edge can be used if they have a pressure surface, a suction surface, a front edge portion, and a rear edge portion. The blade shape of the entire runner vane 18 excluding the above is not limited to that described above. Although the above embodiment was applied to the pump turbine, the present invention can be similarly applied to other turbines having a rotating shaft and a runner connected to the rotating shaft.

  The above description is merely an example, and the present invention is not limited to the above-described embodiments and modifications unless the characteristics of the present invention are impaired. The constituent elements of the embodiment and the modified examples include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. That is, other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. Moreover, it is also possible to arbitrarily combine one or more of the above-described embodiments and modified examples.

11 Pump turbine 12 Rotating shaft 13 Runner 18 Runner vane (runner blade)
31 Pressure surface 32 Negative pressure surface 33 Front edge portion 34 Rear edge portion 35 Start point (first start point, second start point)
40 Concave portion (first uneven portion)
41 Concave portion (second uneven portion)
42 Convex part (first uneven part)
43 Convex part (second uneven part)
44 Groove (first uneven part)
45 Groove (second uneven part)
CL Camber line

Claims (7)

A disc-shaped crown fixed to the rotating shaft about the axis of the rotating shaft, a ring-shaped shroud centered on the axis of the rotating shaft, and fixed so as to be sandwiched between the crown and the shroud. A plurality of runner blades arranged in a circumferential direction centering on the axis of the rotating shaft, and flowing from the radially outer side between the crown and the shroud and from the ring-shaped center of the shroud A hydraulic turbine runner in which working fluid flowing out acts on a plurality of the runner blades and rotates about the axis integrally with the rotary shaft ,
The runner wing is
A pressure surface and a suction surface extending in the flow direction of the working fluid;
A leading edge connecting the pressure surface and the suction surface at the upstream end of the working fluid;
A trailing edge connecting the pressure surface and the suction surface at the downstream end of the working fluid;
A first concavo-convex portion provided in a concavo-convex shape in the vicinity of the rear edge portion on the pressure surface side;
A runner for a water turbine, comprising: a second uneven portion provided in an uneven shape in the vicinity of the rear edge portion on the suction surface side. A turbine runner having a plurality of runner blades on which a working fluid acts,
The runner wing is
A pressure surface and a suction surface extending in the flow direction of the working fluid;
A leading edge connecting the pressure surface and the suction surface at the upstream end of the working fluid;
A trailing edge connecting the pressure surface and the suction surface at the downstream end of the working fluid;
A first concavo-convex portion provided in a concavo-convex shape in the vicinity of the rear edge portion on the pressure surface side;
In a water turbine runner having a second concavo-convex portion provided in a concavo-convex shape in the vicinity of the trailing edge on the suction surface side,
The trailing edge is formed in a curved shape from a first starting point on the pressure surface side to a second starting point on the suction surface side,
The runner for a water turbine, wherein the first uneven portion and the second uneven portion are provided at the first start point and the second start point, respectively. The water turbine runner according to claim 1 ,
The runner for a turbine according to claim 1, wherein the rear edge is formed in a curved shape from a first starting point on the pressure surface side to a second starting point on the suction surface side. In the runner for water turbines according to any one of claims 1 to 3 ,
The runner for a water turbine, wherein the first uneven portion and the second uneven portion are provided symmetrically with respect to a camber line passing through a center of the runner blade. In the runner for water turbines according to any one of claims 1 to 3 ,
The runner for a water turbine, wherein the first uneven portion and the second uneven portion are provided in an asymmetric relationship with respect to a camber line passing through a center of the runner blade. In the runner for water turbines according to any one of claims 1 to 5,
The runner for a water turbine, wherein the first uneven portion and the second uneven portion are provided over a height direction of the runner blade. A rotation axis;
A water turbine comprising: the runner for water turbines according to any one of claims 1 to 6 coupled to the rotating shaft.

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