JP2016205248A - Guide vane and hydraulic machine provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend an operational range in which a hydraulic machine can be suitably operated.SOLUTION: A guide vane 4 includes a blade main body 41 and a guide vane rotation shaft 42 which is connected to the blade main body 41 and rotates the whole of the blade main body 41 with the rotation thereof. The blade main body 41 has at least two split blade parts 43A to 43C which are split in the axial direction of a guide vane rotation shaft 42. Each of the split blade parts 43A to 43C contains a part of an outlet side end part 41A of the blade main body 41. At least one split blade part 43A to 43C rotates around an axial line parallel to the guide vane rotation shaft 42 as a center, independent of the rotation of the whole of the blade main body 41.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a guide vane and a hydraulic machine including the guide vane.

  There are various types of hydraulic machines including Francis turbines and axial flow turbines. For example, in a typical Francis turbine installed in a power plant, the pressure water led to the casing through the iron pipe from the upper pond flows into the runner through the stay vanes and guide vanes arranged on the inner peripheral side of the casing. To do. The pressure energy of the pressure water flowing into the runner is converted into rotational energy in the runner. Electric power is generated by rotating the generator coupled to the runner rotation shaft of the runner by this rotational energy. The pressure water flowing out of the runner is discharged downstream (lower pond) through the suction pipe.

  Further, in a general Francis turbine, a plurality of the above-described guide vanes are arranged at an equal pitch around the runner rotation axis, and each guide vane has a guide vane rotation axis and rotates around the rotation axis. It is possible. Each guide vane rotating shaft is connected to a link mechanism, and this link mechanism is configured to simultaneously and uniformly adjust the angle of each guide vane by rotating each guide vane rotating shaft. As a result, by adjusting the angle of the guide vane from the fully closed state to the fully open state determined according to the maximum stroke of the link mechanism, it is possible to supply the runner with a flow rate of pressure water corresponding to the required output. it can.

  In such a Francis turbine, there is a head range and an output range that are unique to each installed power plant. In the head range, a design head that can operate the turbine with high efficiency is set. However, at operating points that deviate from this design head, vortices due to cavitation and separation may occur near the runner entrance. This will be described with reference to FIGS.

  FIG. 9 shows a velocity triangle of the flow on the runner inlet side at an operating point near the design head of a general Francis turbine. FIG. 10 shows a velocity triangle of the flow on the runner inlet side when the operating point on the high head side is reached from the state shown in FIG. FIG. 11 shows a flow velocity triangle on the runner inlet side when the operating point on the low head side is reached from the state shown in FIG. 9 to 11, reference numeral 100 indicates a guide vane, and reference numeral 101 indicates a runner blade of the runner. Further, the angles of the guide vanes 100 shown in FIGS. 9 to 11 are the same.

  In FIG. 9, the symbol β represents the runner inlet angle, the symbol Cu represents the peripheral velocity coefficient, the symbol Cv represents the absolute flow velocity coefficient of the pressure water flowing from the guide vane 100 to the runner blade 101, and the symbol Cw is The relative speed coefficient obtained from the peripheral speed coefficient Cu and the absolute flow coefficient Cv is shown. The symbol α indicates a relative inflow angle obtained from the relative speed coefficient Cw and the peripheral speed coefficient Cu.

  At the operating point in the vicinity of the design head shown in FIG. 9, the runner inlet angle β and the relative inflow angle α are substantially the same angle. In such operating conditions, vortices due to cavitation and separation are unlikely to occur.

  On the other hand, as shown in FIG. 10, at the operating point on the high head side, the peripheral velocity coefficient indicated by the symbol Cu ′ is relatively smaller than the absolute flow velocity coefficient indicated by the symbol Cv ′. The relative inflow angle α ′ obtained from the relative speed coefficient indicated by the symbol Cw ′ and the peripheral speed coefficient Cu ′ becomes larger than the runner inlet angle β. As a result, cavitation X tends to occur on the suction surface on the inlet side of the runner blade 101.

  Further, as shown in FIG. 11, at the operating point on the low head side, the peripheral speed coefficient indicated by the symbol Cu ″ is relatively larger than the absolute flow velocity coefficient indicated by the symbol Cv ″. The relative inflow angle α ″ obtained from the relative speed coefficient indicated by the symbol Cw ″ and the peripheral speed coefficient Cu ″ is smaller than the runner inlet angle β. As a result, the vortex Y due to separation tends to occur on the pressure surface on the inlet side of the runner blade 101.

  As described above, in a general Francis turbine, when the difference between the relative inflow angle and the runner inlet angle increases due to deviation from the design head, vortices due to cavitation and separation tend to occur. Such vortices due to cavitation and separation rarely occur as a whole from the crown at the inlet end of the runner blade 101 to the band, and often occur from the band side or part of the crown side.

  If the operation is performed for a long time in a state where cavitation has occurred, the runner surface of the runner may be eroded in the region where the cavitation has occurred, and the life of the equipment may be shortened. In addition, when a vortex due to separation accompanied by vibration or noise occurs, the operation may be hindered in addition to the decrease in efficiency, and thus an operation that avoids such an operation state may be necessary. Therefore, the initial point of the vortex due to cavitation and separation is generally used as a guideline for limiting the operation range of the water turbine.

  FIG. 12 shows an example of a turbine performance diagram of a general Francis turbine. In this diagram, the horizontal axis indicates a drop and the vertical axis indicates a flow rate. An alternate long and short dash line L11 indicates an initial line of cavitation on the runner inlet pressure surface, and an alternate long and short dash line L12 indicates an initial line of separation (separation vortex) on the runner inlet pressure surface. A plurality of broken lines indicate isoefficiency lines. In the diagram shown in FIG. 12, the hatched portion in the drawing includes a range indicated by two primary lines L11 and L12, and cavitation and separation may occur at such an operating point. Driving may be limited.

JP 2000-120521 A

  As described above, the occurrence of cavitation and separation limits the operating range in which the water turbine can be suitably operated. If it is possible to suppress the occurrence of such cavitation and separation, the limited operation range can be expanded. Expansion of the operating range is beneficial because it expands the installation conditions that allow the water turbine to be suitably driven.

  This invention is made | formed in view of such a situation, and it aims at providing a guide vane which can expand the driving | running | working range which can operate a hydraulic machine suitably, and a hydraulic machine provided with the same.

  The guide vane according to the embodiment includes a blade main body and a guide vane rotation shaft that is connected to the blade main body and rotates the entire blade main body by the rotation thereof. The blade body includes at least two divided blade portions divided in the axial direction of the guide vane rotation shaft. Each of the divided blade portions includes a part of the outlet side end portion of the blade body. At least one of the divided blade portions rotates about an axis parallel to the guide vane rotation axis independently of the entire rotation of the blade body.

  Moreover, the hydraulic machine by embodiment is provided with said guide vane.

  ADVANTAGE OF THE INVENTION According to this invention, the driving | operation range which can drive | operate a hydraulic machine suitably can be expanded.

It is a schematic diagram of a Francis turbine concerning a 1st embodiment. It is a figure explaining the effect | action of 1st Embodiment. It is a figure explaining the effect | action of 1st Embodiment. It is the figure which showed the turbine performance diagram explaining the effect of 1st Embodiment. (A) is the schematic of the Francis turbine which concerns on 2nd Embodiment, (B) is a figure explaining the effect | action of the Francis turbine which concerns on 2nd Embodiment. (A) is the schematic of the Francis turbine which concerns on 3rd Embodiment, (B) is the figure which looked at the guide vane of the Francis turbine which concerns on 3rd Embodiment in the axial direction. It is the schematic of the Francis turbine which concerns on 4th Embodiment. It is the schematic of the Francis turbine which concerns on 5th Embodiment. It is the figure which showed the velocity triangle of the flow on the runner inlet side in the operating point of the design head vicinity of a general Francis turbine. FIG. 10 is a diagram showing a velocity triangle of the flow on the runner inlet side when the operating point on the high head side is reached from the state shown in FIG. 9. FIG. 10 is a diagram showing a velocity triangle of the flow on the runner inlet side when the operating point on the low head side is reached from the state shown in FIG. 9. It is the figure which showed an example of the water turbine performance diagram of a general water wheel.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 shows a Francis turbine 1 as a hydraulic machine according to a first embodiment of the present invention. The Francis turbine 1 includes a casing 2 into which pressure water flows from an upper pond (not shown) through an iron pipe, a plurality of stay vanes 3, a plurality of guide vanes 4, and a runner 5. The casing 2 supplies the pressure water flowing from the upper pond to the stay vane 3 in the circumferential direction. The plurality of stay vanes 3 are for guiding water flowing out from the casing 2 to the guide vanes 4, and are arranged at predetermined intervals in the circumferential direction on the inner peripheral side of the casing 2.

  The plurality of guide vanes 4 are for guiding the inflowing water to the runner 5, and are arranged at predetermined intervals in the circumferential direction on the inner peripheral side of the stay vanes 3. Each of the guide vanes 4 includes a blade main body 41 disposed in a flow path formed between an upper cover and a lower cover (not shown), and is connected to the blade main body 41 and rotates the entire blade main body 41 by rotation thereof. And a guide vane rotating shaft 42 to be rotated. L1 in the figure indicates a rotation axis passing through the center of the guide vane rotation shaft 42.

  In the illustrated example, the guide vane rotating shaft 42 extends upward in the drawing, and is connected to the driving device 6 having a link mechanism outside the upper cover (not shown). Each guide vane rotation shaft 42 is connected to a link mechanism of the drive device 6, and the drive device 6 rotates each guide vane rotation shaft 42 via the link mechanism, thereby the entire angle of each blade body 41. Can be adjusted simultaneously and uniformly. Thereby, the pressure water of a desired flow rate can be supplied from the guide vane 4 to the runner 5.

  The runner 5 is configured to be rotatable about the rotation axis C <b> 1 with respect to the casing 2, and is rotated by water flowing out from the guide vane 4. The runner 5 includes a crown 51, a band 52, and a plurality of runner blades 53 provided between the crown 51 and the band 52. The plurality of runner blades 53 are arranged at predetermined intervals in the circumferential direction.

  A generator 8 is connected to the runner 5 via a main shaft 7, and the generator 8 generates power by being rotated by the runner 5. A suction pipe 9 is provided on the downstream side of the runner 5. The pressure water flowing out of the runner 5 is discharged to the lower pond through the suction pipe 9.

  As shown in FIG. 1, in the present embodiment, the blade body 41 includes a first divided blade portion 43A, a second divided blade portion 43B, which are divided in the axial direction of the guide vane rotation shaft 42 (the direction of the rotation axis L1). And each of the divided blade portions 43A to 43C includes a part of the outlet side end portion 41A of the blade body 41. In this example, each of the blade bodies 41 of the plurality of guide vanes 4 includes a first divided blade portion 43A, a second divided blade portion 43B, and a third divided blade portion 43C.

  The first divided blade portion 43A is disposed on the crown 51 side, the third divided blade portion 43C is disposed on the band 52 side, and the second divided blade portion 43B includes the first divided blade portion 43A and the third divided blade portion. 43C. In the present embodiment, the first divided blade portion 43A and the second divided blade portion 43B are divided lines extending from the outlet side end portion 41A of the blade body 41 to the inlet side end portion 41B perpendicular to the rotation axis L1 ( It is divided according to the division position. Similarly, the second divided blade portion 43B and the third divided blade portion 43C are divided by a dividing line that is orthogonal to the rotation axis L1 and extends from the outlet side end portion 41A to the inlet side end portion 41B.

  Each of the divided blade portions 43 </ b> A to 43 </ b> C is configured to rotate independently of the entire rotation of the blade body 41 around an axis parallel to the guide vane rotation shaft 42. In the present embodiment, each of the divided blade portions 43 </ b> A to 43 </ b> C is rotatable around an axis that is coaxial with the rotation axis L <b> 1 of the guide vane rotation shaft 42.

  Various mechanisms may be applied as a mechanism for rotating each of the divided blade portions 43A to 43C independently of the entire rotation of the blade body 41. For example, each between the guide vane rotating shaft 41 and the first divided blade portion 43A, between the first divided blade portion 43A and the second divided blade portion 43B, and between the second divided blade portion 43B and the third divided blade portion 43C. A clutch that enables or disables relative rotation between the two members, a drive shaft that rotates the first divided blade portion 43A, a drive shaft that rotates the second divided blade portion 43B, and a third divided blade portion Even if a drive shaft for rotating 43C is arranged in triplicate, and a mechanism for rotating the desired split blade portions 43A to 43C by rotating the desired drive shaft by appropriately switching the clutch is adopted. Good.

  Next, the operation of the present embodiment will be described.

  In the Francis turbine 1 according to the present embodiment, the pressure water guided from the upper pond is guided to the casing 2 through the iron pipe. The pressure water is made uniform in the circumferential direction by the casing 2, and flows into the runner 5 through the stay vane 3 and the guide vane 4 arranged on the inner peripheral side of the casing 2. The runner 5 is rotated by the pressure energy of the passing pressure water and drives the generator 8 connected via the main shaft 7. As a result, the generator 8 generates power. The pressurized water flowing out of the runner 5 is discharged to the lower pond through the suction pipe 9.

  The guide vane 4 determines the angle of the flow flowing into the runner 5 at an arbitrary height position (a position in the axial direction of the guide vane rotation shaft 42) facing the region from the crown 51 to the band 52 of the runner 5 in the radial direction. It can be changed according to various operating points. Specifically, in the present embodiment, by selectively independently rotating the divided blade portions 43A to 43C corresponding to arbitrary height positions, the angle of the flow flowing into the runner 5 is set according to various operating points. Can be changed.

  The manner in which the angle of the flow of the guide vane 4 flowing into the runner 5 is changed according to the operating point will be specifically described with reference to FIGS.

  FIG. 2 shows the velocity triangle of the flow on the inlet side of the runner 5 when the Francis turbine 1 becomes the operating point on the high head side while maintaining the guide vane 4 at a predetermined angle from the operating point of the design head. Is shown as a solid line. At such a high head operating point, as described in FIG. 10, the relative inflow angle α ′ from the guide vane 4 becomes larger than the runner inlet angle β. As a result, cavitation X tends to occur on the inlet suction surface side of the runner blade 53 of the runner 5.

  In such a state, the guide vane 4 according to the present embodiment selectively separates the divided blade portions 43A to 43C corresponding to the position where the cavitation X is generated, as indicated by the broken line in FIG. By rotating, the angles (openings) of the divided blade portions 43A to 43C corresponding to the position where the cavitation X is generated can be reduced. As a result, the relative inflow angle to the runner 5 can be reduced from α ′ to α1 ′, so that the relative inflow angle α1 ′ can be brought close to the runner inlet angle β by local change. As a result, it is possible to suppress cavitation X that has occurred on the inlet suction surface side of the runner blade 53.

  On the other hand, FIG. 3 shows the flow of the flow on the inlet side of the runner 5 when the guide vane 4 is kept at the predetermined operating point while maintaining the predetermined operating angle from the operating point of the design head of the Francis turbine 1. The speed triangle is shown as a solid line. In such an operating range on the low head side, as described in FIG. 11, the relative inflow angle α ″ from the guide vane 4 becomes smaller than the runner inlet angle β. As a result, the vortex Y due to separation tends to occur on the inlet pressure surface side of the runner blade 53 of the runner 5.

  In such a state, the guide vane 4 according to the present embodiment selectively selects the divided blade portions 43A to 43C corresponding to the positions where the separation (vortex Y) is generated, as shown by the broken lines in FIG. By rotating independently, the angles (openings) of the divided blade portions 43A to 43C corresponding to the positions where the separation is generated can be increased. Thereby, the relative inflow angle to the runner 5 can be increased from α ″ to α1 ″, and α1 ″ can be brought close to the runner inlet angle β by local change. As a result, it is possible to suppress peeling that has occurred on the pressure surface side of the runner blade 53.

  Thus, according to the present embodiment, the blade body 41 of the guide vane 4 is rotated independently of the whole at an arbitrary height position, and the angle of the flow flowing from the guide vane 4 to the runner 5 is optimized. By doing so, the flow flowing into the runner 5 can be optimized. In particular, as described with reference to FIGS. 2 and 3, it is possible to suppress phenomena such as cavitation and separation that cause various obstacles to the operation of the water turbine that occurs on the inlet side of the runner 5. As a result, the operating range in which the water turbine can be suitably driven can be expanded.

  FIG. 4 is a diagram showing a water turbine performance diagram for explaining the effect of the first embodiment. In the same figure, an example of the performance chart of the general turbine shown in FIG. 12 and its operating range are shown. In addition, the description about the matter similar to the matter demonstrated using FIG. 12 is abbreviate | omitted.

  That is, according to the present embodiment, as described above, the phenomenon indicated by the arrow D1 in FIG. 4 is suppressed by suppressing the phenomenon that causes various obstacles to the operation of the water turbine that occurs on the inlet side of the runner 5, such as cavitation and separation. Thus, it is possible to move the initial line L21 to the high head side rather than the initial line L11 of cavitation on the inlet side of the runner of a general Francis turbine. Further, as shown by an arrow D2 in FIG. 4, the initial line L22 can be moved to the lower head side than the peeled initial line L12 on the inlet side of the runner of a typical Francis turbine.

  As described above, according to the present embodiment, it is possible to suppress the occurrence of these phenomena at an operating point where cavitation or separation has occurred in a general Francis turbine. As in the range indicated by the two-dot chain line, it is possible to expand the operating range in which driving can be suitably performed.

(Second Embodiment)
Next, FIG. 5 shows a diagram for explaining the Francis turbine according to the second embodiment. The same components as those of the first embodiment described above in the present embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 5A, in the present embodiment, the guide vane 4 is divided into the first divided blade portion 44A and the second divided blade portion 44B divided in the axial direction of the guide vane rotating shaft 42, and the guide vane. And an elastic body 60 that connects between the flowing water surfaces of the two divided blade portions 44A and 44B adjacent in the axial direction of the rotating shaft 42. Each of the divided blade portions 43 </ b> A and 43 </ b> B includes a part of the outlet side end portion 41 </ b> A of the blade body 41. In FIG. 5, for convenience of explanation, the elastic body 60 is shown with dots.

  Each of the first divided blade portion 44 </ b> A and the second divided blade portion 44 </ b> B rotates around an axis parallel to the guide vane rotation shaft 42 independently of the entire rotation of the blade body 41. In the present embodiment, each of the first divided blade portion 44 </ b> A and the second divided blade portion 44 </ b> B is rotatable around an axis line coaxial with the rotation axis L <b> 1 of the guide vane rotation shaft 42. The first divided blade portion 44A and the second divided blade portion 44B are divided by a dividing line that is orthogonal to the rotation axis L1 and extends from the outlet side end 41A to the inlet side end 41B. Accordingly, the first divided blade portion 44A is disposed on the crown 51 side, and the second divided blade portion 44B is disposed on the band 52 side.

  The elastic body 60 is disposed in a gap in the axial direction of the guide vane rotation shaft 42 formed between the first divided blade portion 44A and the second divided blade portion 44B, and is a direction orthogonal to the guide vane rotation shaft 42. The cross-sectional shape of the elastic body 60 is the same as the cross-sectional shape of the first divided blade portion 44A and the second divided blade portion 44B. The elastic body 60 has a pressure surface and a suction surface. The pressure surface of the elastic body 60 connects between the pressure surface of the first divided blade portion 44A and the pressure surface of the second divided blade portion 44B. The negative pressure surface of the elastic body 60 is connected to the pressure surface of the first divided blade portion 44A. The negative pressure surface and the negative pressure surface of the second divided blade portion 44B are connected. The elastic body 60 is elastically deformed around the center of rotation when the first divided blade portion 44A rotates relative to the second divided blade portion 44B.

  According to the present embodiment, as shown in FIG. 5 (B), when the first divided blade portion 44A rotates relative to the second divided blade portion 44B, the elastic body 60 moves to the first divided blade portion 44A. Are smoothly connected to the water surface of the second divided blade portion 44B. Thereby, it becomes possible to eliminate the discontinuous gap between the first divided blade portion 44A and the second divided blade portion 44B.

  As a result, it is possible to effectively expand the operating range in which the Francis turbine 1 can be suitably operated.

(Third embodiment)
Next, FIG. 6 shows a diagram for explaining the Francis turbine according to the third embodiment. Constituent parts similar to those of the first and second embodiments described above in the present embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 6A, in the present embodiment, the guide vane 4 includes a first divided blade portion 45A and a second divided blade portion 45B that are divided in the axial direction of the guide vane rotation shaft 42. Yes. Each of the divided blade portions 45 </ b> A and 45 </ b> B includes a part of the outlet side end portion 41 </ b> A of the blade body 41.

  In the present embodiment, the second divided blade portion 45B of the first divided blade portion 45A and the second divided blade portion 45B rotates the entire blade body 41 around an axis parallel to the guide vane rotation shaft 42. It is designed to rotate independently. Specifically, the second divided blade portion 45B is rotatable around an axis line that is coaxial with the rotation axis L1 of the guide vane rotation shaft 42.

  The first divided blade portion 45A and the second divided blade portion 45B are orthogonal to the rotation axis L1 and extend from the outlet side end 41A toward the inlet side end 41B, and are closer to the inlet side end 41B than the rotation axis L1. It is divided by a dividing line that is bent at a position and extends toward the band 52 along the rotation axis L1. Thereby, in this Embodiment, the whole inlet side edge part 41B of the blade | wing main body 41 is provided in 45 A of 1st division | segmentation blade | wing parts. Therefore, the inlet side end portion 41 </ b> B of the blade body 41 extends continuously in the axial direction without being divided in the axial direction of the guide vane rotation shaft 42.

  According to the present embodiment, the inlet side end portion 41B of the guide vane 4 has the same shape in the whole height direction (the axial direction of the guide vane rotating shaft 42), so as shown in FIG. While maintaining the relative relationship with, for example, the stay vane 3 of the two-dimensional blade located upstream, the second divided blade 45B is rotated independently of the whole so that the flow flowing into the runner 5 from the guide vane 4 The angle can be optimized.

  As a result, it is possible to expand the operation range that can be suitably operated while maintaining the characteristics determined by the positional relationship between the guide vanes 4 and the stay vanes 3.

(Fourth embodiment)
Next, FIG. 7 shows a diagram for explaining the Francis turbine according to the fourth embodiment. The same components as those of the first to third embodiments described above in the present embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, in the present embodiment, the guide vane 4 has a first divided blade portion 46 </ b> A and a second divided blade portion 46 </ b> B that are divided in the axial direction of the guide vane rotation shaft 42. Each of the divided blade portions 46 </ b> A and 46 </ b> B includes a part of the outlet side end portion 41 </ b> A of the blade body 41.

  In the present embodiment, the second divided blade portion 46B of the first divided blade portion 46A and the second divided blade portion 46B rotates the entire blade body 41 around an axis parallel to the guide vane rotation shaft 42. It is designed to rotate independently. The second divided blade portion 46B is rotatable around an axis located coaxially with the rotation axis L1 of the guide vane rotation shaft 42.

  46 A of 1st division | segmentation blade | wing parts and the 2nd division | segmentation blade | wing part 46B are divided | segmented by the division line orthogonal to the rotating shaft L1 and extending from 41 A of exit side edge parts to 41 A of edge parts by the side of entrance. The first divided blade portion 46A is disposed on the crown 51 side, and the second divided blade portion 46B is disposed on the band 52 side.

  The dividing line between the first divided blade portion 46A and the second divided blade portion 46B is set on the band 52 side of the blade body 41. More specifically, the first divided blade portion 46 </ b> A and the second divided blade portion 46 </ b> B are divided on the band 52 side from the intermediate position in the height direction of the blade body 41. More specifically, the first divided blade portion 46A and the second divided blade portion 46B are closer to the band 52 side than the intermediate position between the intermediate position in the height direction of the blade body 41 and the end portion on the band 52 side. It is divided by.

  According to the present embodiment, only a limited portion of the blade body 41 on the band 52 side can be rotated independently of the entire rotation. As shown in FIG. 7, generally, cavitation X and separation Y rarely occur uniformly on the entire inlet side of the runner 5. Therefore, according to the present embodiment, when cavitation X and separation Y are likely to occur on the band 52 side, the cavitation X and separation Y can be suppressed with a relatively simple structure.

(Fifth embodiment)
Next, FIG. 8 shows a diagram for explaining the Francis turbine according to the fifth embodiment. Constituent parts similar to those of the first to fourth embodiments described above in the present embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 8, in the present embodiment, the guide vane 4 has a first divided blade portion 47 </ b> A and a second divided blade portion 47 </ b> B that are divided in the axial direction of the guide vane rotation shaft 42. Each of the divided blade portions 47 </ b> A and 47 </ b> B includes a part of the outlet side end portion 41 </ b> A of the blade body 41.

  In the present embodiment, of the first divided blade portion 47A and the second divided blade portion 47B, the first divided blade portion 47A rotates the entire blade body 41 around an axis parallel to the guide vane rotation shaft 42. It is designed to rotate independently. 47 A of 1st division | segmentation blade | wing parts are rotatable centering on the axis line located coaxially with the rotating shaft L1 of the guide vane rotating shaft 42. As shown in FIG.

  47 A of 1st division | segmentation blade | wing parts and the 2nd division | segmentation blade | wing part 47B are divided | segmented by the division line orthogonal to the rotating shaft L1 and extending from 41 A of exit side edge parts to 41 A of edge parts by the side of entrance. The first divided blade portion 47A is disposed on the crown 51 side, and the second divided blade portion 47B is disposed on the band 52 side.

  The dividing line between the first divided blade portion 47A and the second divided blade portion 47B is set on the crown 51 side of the blade body 41. More specifically, the first divided blade portion 47A and the second divided blade portion 47B are divided on the crown 51 side with respect to the intermediate position in the height direction of the blade body 41. More specifically, the first divided blade portion 47A and the second divided blade portion 47B are closer to the crown 51 side than the intermediate position between the intermediate position in the height direction of the blade body 41 and the end portion on the crown 51 side. It is divided by.

  According to the present embodiment, only a limited portion of the blade body 41 on the crown 51 side can be rotated independently of the entire rotation. As shown in FIG. 8, cavitation X and separation Y generally do not occur uniformly over the entire inlet side of the runner 5. Therefore, according to the present embodiment, when cavitation X and separation Y are likely to occur on the crown 51 side, the cavitation X and separation Y can be suppressed with a relatively simple structure.

  Although the embodiment of the present invention has been described above, the above embodiment is presented as an example, and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, in each of the above-described embodiments, the example in which the guide vane 4 is divided into three or two divided blade portions has been described, but the guide vane 4 may be divided into four or more. The axis parallel to the guide vane rotation axis described in the present embodiment means an axis coaxial with the rotation axis of the guide vane rotation axis, or an axis extending away from the rotation axis and parallel to the rotation axis. To do.

DESCRIPTION OF SYMBOLS 1 Francis turbine (hydraulic machine), 2 casing, 3 stay vane, 4 guide vane, 5 runner, 6 drive device, 7 spindle, 8 generator, 9 suction pipe, 41 blade body, 41A outlet side end, 41B inlet side end Part, 42 guide vane rotating shaft, 43A, 44A, 45A, 46A, 47A first divided blade part, 43B, 44B, 45B, 46B, 47B second divided blade part, 43C third divided blade part, 51 crown, 52 band 53 runner blades, 60 elastic bodies.

Claims (6)

A guide vane comprising: a blade body; and a guide vane rotating shaft coupled to the blade body and rotating the entire blade body by rotation thereof,
The blade body has at least two divided blade portions divided in the axial direction of the guide vane rotation shaft,
Each of the divided blade portions includes a part of the outlet side end portion of the blade body,
The guide vane is characterized in that at least one of the divided blade portions rotates about an axis parallel to the guide vane rotation axis independently of the entire rotation of the blade body.   2. The guide vane according to claim 1, wherein the blade body further includes an elastic body that connects between the water flow surfaces of the two divided blade portions adjacent in the axial direction of the guide vane rotation axis.   The guide vane according to claim 1, wherein an inlet side end portion of the blade main body extends continuously in the axial direction without being divided in the axial direction of the guide vane rotation shaft. The guide vane is arranged upstream of the inlet side of the runner in which a runner blade is provided between the crown and the band,
The blade body has two divided blade portions,
Of the two divided blade portions, the divided blade portion whose outlet side end portion is located on the band side is configured to rotate independently of the entire rotation of the blade body. The guide vane according to any one of claims 1 to 3. The guide vane is arranged upstream of the inlet side of the runner in which a runner blade is provided between the crown and the band,
The blade body has two divided blade portions,
Of the two divided blade portions, the divided blade portion whose outlet side end portion is located on the crown side is configured to rotate independently of the entire rotation of the blade body. The guide vane according to any one of claims 1 to 3.   A hydraulic machine provided with the guide vane in any one of Claims 1 thru | or 5.

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