Runners and hydraulic machinery

Abstract

The problem that this invention aims to solve is to ensure the strength of the exit end of the runner blade. The objective is to provide a hydraulic machine runner that can reduce runner losses. [Solution] In order to achieve the above objective, the runner of the hydraulic machine of this embodiment has a crown and The water flowing into the runner vanes provided between the band, the runner vanes located on the downstream side in the flow direction The exit end of the fin blade is provided to protrude from the band side toward the downstream side in the flow direction. The extended outlet end band side portion, and the flow from the crown side of the outlet end It comprises an outlet end crown-side extension portion provided to protrude downstream, and the outlet end The negative pressure surface of the extension on the band side and the extension on the crown side of the outlet end has the following characteristics downstream in the flow direction: It is characterized by having a sloping section that becomes thinner towards the side.

Description

Technical Field

[0001] Embodiments of the present invention relate to a runner of a hydraulic machine and a hydraulic machine.

Background Art

[0002] During the operation of a Francis turbine, which is a type of hydraulic machine, the water that flows from the upper pond through the penstock and into the casing flows from the casing through the stay vanes and guide vanes and into the runner. When the runner is rotationally driven by the water flowing into the runner, a generator connected to the runner via a main shaft is driven to generate electricity. Thereafter, the water that has rotationally driven the runner flows out from the runner through the draft tube and into the lower pond or a discharge channel.

[0003] Such a runner of a Francis turbine includes a disk-shaped crown connected to the main shaft to transmit the rotational force of the runner to the generator motor via the main shaft, an annular band provided outside and opposite the crown, and a plurality of runner blades provided at a constant circumferential interval between the crown and the band. Water flow paths are formed between adjacent runner blades. The runner blades are rotationally driven by receiving pressure from the water flowing into these flow paths during the operation of the Francis turbine.

[0004]

[0005] In this case, the runner blades are subjected to loads such as bending moment by the water pressure. In particular, the end portion on the outlet side (draft tube side) of the runner blade is known to receive an impact load during turbine startup. Therefore, the end portion on the outlet side of the runner blade needs to have a thickness that can withstand this load.

[0006] ​Furthermore, if Karman vortices are generated in the wake on the exit side of the runner blade, alternating vortices will occur due to this vortex street. An excitation force is generated. In particular, the frequency of the excitation force of the Karman vortex approaches the natural frequency of the runner vane. This can lead to vibrations with large amplitudes, which are known to cause fatigue failure of the runner. To suppress the generation of this vibration, the shape of the exit side of the runner blade is gradually made thinner. Therefore, the shape of the exit side of the runner blade needs to be asymmetrical. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] US2022 / 0120253A1 publication [Overview of the project] [Problems that the invention aims to solve]

[0007] As described above, the strength of the exit end of the runner blade is ensured, and the generation of Karman vortices is also controlled. To mitigate this, the outlet end needs to be thickened to withstand the load from the water. On the other hand, it is also necessary to thin the outlet end to reduce runner losses. To solve these problems together, we are exploring the optimal shape for the exit end of the runner blade. That was necessary. The problem that this invention aims to solve is to ensure the strength of the exit end of the runner blade while The objective is to provide a hydraulic machine runner that can reduce runner losses. [Means for solving the problem]

[0008] The runner of the hydraulic machine according to this embodiment has runner blades provided between the crown and the band. Of the outlet ends of the runner blades located on the downstream side in the direction of water flow into the roots, the An outlet end band side extension provided so as to project from the Indian side toward the downstream side in the flow direction, and Of the outlet end portion, an outlet end crown side extension provided so as to project from the crown side toward the downstream side in the flow direction And, the outlet end band side extension and the outlet end On the negative pressure surfaces of the crown side extensions, there are inclined portions formed so that the thickness becomes thinner toward the downstream side in the flow direction It is characterized by being formed.

Brief Description of the Drawings

[0009] [Figure 1] Vertical sectional view of a Francis turbine. [Figure 2] View taken along the A-A arrow in FIG. 1. [Figure 3] Enlarged view of region P in FIG. 2. [Figure 4] Enlarged view of region Q in FIG. 3. [Figure 5] Enlarged view of region R in FIG. 3. [Figure 6] Schematic diagram created based on the flow analysis results. [Figure 7] Comparison table created based on the flow analysis results.

Modes for Carrying Out the Invention

[0010] Hereinafter, the runner and the hydraulic machine according to the embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are examples of the embodiments of the present invention, and are not intended to limit the scope of the invention. Also, in the drawings referred to in the embodiments, the same parts or parts having the same function are denoted by the same reference numerals or similar reference numerals, and the description thereof may be omitted. Also, there are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings. And, the runner and the hydraulic machine according to the embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are examples of the embodiments of the present invention, and are not intended to limit the scope of the invention. Also, in the drawings referred to in the embodiments, the same parts or parts having the same function are denoted by the same reference numerals or similar reference numerals, and the description thereof may be omitted. Also, there are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings. The embodiments shown below are examples of the embodiments of the present invention, and are not intended to limit the scope of the invention. Also, in the drawings referred to in the embodiments, the same parts or parts having the same function are denoted by the same reference numerals or similar reference numerals, and the description thereof may be omitted. Also, there are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings. In the drawings referred to in the embodiments, the same parts or parts having the same function are denoted by the same reference numerals or similar reference numerals, and the description thereof may be omitted. Also, there are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings. And, the runner and the hydraulic machine according to the embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are examples of the embodiments of the present invention, and are not intended to limit the scope of the invention. Also, in the drawings referred to in the embodiments, the same parts or parts having the same function are denoted by the same reference numerals or similar reference numerals, and the description thereof may be omitted. Also, there are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings. There are cases where the dimensional ratios in the drawings are different from the actual ratios, or a part of the configuration is omitted from the drawings.

[0011] (First embodiment) Using Figure 1, we will explain the Francis turbine 1, a type of hydraulic machine. Figure 1 is This is a cross-sectional view of a Francis turbine 1. As shown in Figure 1, the Francis turbine 1 is a k Thing 2, stay vane 3, guide vane 4, runner 5, main shaft 6, generator 7 It is equipped with a draft tube 8 and a main Francis turbine 1. Let the axis direction of axis 6 be axis direction X, and the upper side of axis direction X be simply referred to as the upper side, and the lower side of axis direction X be simply referred to as the lower side. Furthermore, in the following explanation, the radially outward direction centered on the axial direction X will simply be referred to as the radially outward direction. The area inside the radial direction centered on the axial direction X is simply referred to as the radially inside.

[0012] Casing 2 receives water from the upper reservoir through the penstock (neither of which is shown in the diagram) when the turbine is in operation. It is a spiral-shaped component that enters. Casing 2 is a sieve that holds the water that flows into casing 2. Lead to step 3.

[0013] The stay vane 3 is a component provided on the radially inward side of the casing 2. 3 consists of multiple units spaced at regular intervals in the circumferential direction (hereinafter referred to as the circumferential direction) centered on the axial direction X. They are arranged such that the stay vanes 3 form a water channel between adjacent stay vanes 3. It is working. Stay vane 3 guides the water that flows into stay vane 3 to guide vane 4.

[0014] Guide vane 4 is a member provided radially inward of stay vane 3. Multiple guide vanes 4 are arranged at regular intervals in the circumferential direction. A water channel is formed between the intersecting guide vanes 4. The guide vanes 4 are The water flowing into 4 is guided to runner 5. Also, guide vane 4 is connected to guide ring (not shown). The opening degree can be changed by this configuration. As a result, the guide vane 4 changes the opening degree. This configuration allows for adjustment of the water flow rate directed to Runner 5.

[0015] Runner 5 is a component located radially inward of guide vane 4. Runner 5 is the main shaft It is connected to the lower end of 6 and is configured to rotate about the rotation axis X. Runner 5 is The water flowing into the 5 creates pressure, causing it to rotate around the rotation axis X. Runner 5 converts the pressure energy of the water acting on it into rotational energy. Runner 5 comprises a crown 10, a band 11, and a runner blade 12.

[0016] The crown 10 is a disc-shaped member connected to the main shaft 6. The crown 10 is connected to the runner 5 This component transmits the rotational energy of the runner 5, generated by the water flowing into it, to the main shaft 6. .

[0017] Band 11 is connected to the upper end of the suction tube 8 and to the radially outer side of the crown 10. Furthermore, it is an annular member positioned opposite the crown 10.

[0018] The runner blades 12 are positioned between the crown 10 and the band 11 at a constant distance in the circumferential direction. It is a component with multiple parts. The runner blades 12 have water between them. It forms a flow path. The runner blade 12 has an end that is on the inlet side or outlet side of the water flow path. It possesses. Specifically, the direction of water flow into the runner blade 12 (hereinafter simply referred to as "flow direction"). The upstream end becomes the inlet end, and the downstream end in the flow direction becomes the outlet end. During the operation of the Francis turbine 1, the guide vane 4 side of the runner blade 12 (flow The end on the upstream side in the direction of flow becomes the inlet end 13, and the suction pipe 8 side of the runner blade 12 (flow direction) The downstream end becomes the outlet end 14. The runner blades 12 are subjected to pressure by the incoming water. It is configured to be rotatable.

[0019] The main shaft 6 is the rotation axis of the runner 5. The main shaft 6 connects the runner 5 and the generator 7. The main shaft 6 transmits the rotational energy of the runner 5 to the generator 7.

[0020] The generator 7 is a device that generates electricity when the turbine is in operation. The generator 7 is connected to the runner via the main shaft 6. It is connected to 5. The generator 7 receives the rotational energy of the runner 5 transmitted through the main shaft 6. It is driven by rotation and generates electricity.

[0021] Furthermore, the generator 7 also functions as an electric motor, supplying power to rotate the runner 5. It may be made drivable. That is, the Francis turbine 1 drives the water in the lower pond (not shown). It may be possible to make it possible to pump up the water and release it into the upper reservoir (pumping operation). During pumping operation of the N-type turbine 1, the suction pipe 8 side of the runner blades 12 (upstream in the flow direction) The end of the side becomes the inlet end, and the guide vane 4 side (downstream side in the flow direction) of the runner blade 12 The end becomes the exit end.

[0022] The suction pipe 8 is a component located on the lower side of the runner 5. The suction pipe 8 is located in the lower pond or discharge It is connected to a waterway (not shown in the diagram) and discharges the water flowing out of Runner 5 into the lower reservoir or discharge channel.

[0023] Next, using Figures 2 to 5, the outlet end 14 of the runner blade 12 according to the first embodiment Let's explain the structure. Figure 2 is a view from arrow AA in Figure 1. Figure 3 is in Figure 2. Figure 4 is an enlarged view of region P in Figure 3. Figure 4 is an enlarged view of region Q in Figure 2. This is an enlarged view of region R.

[0024] As shown in Figure 2, during the operation of the water turbine of the runner 5 according to the first embodiment, the guide beam Water flowing into runner 5 from the inlet end 13 on the runner 4 side flows along the flow direction B towards the suction pipe 8 side It flows out from the outlet end 14. Specifically, when the runner 5 is operating according to the first embodiment. In this case, the water flowing into runner 5 forms a vortex along the flow direction B with the rotation axis X as the center. The water flows radially inward in this manner. In the following explanation, the turbine operation of Francis turbine 1 With the transition time in mind, the details of the exit end 14 of the runner blade 12 will be described.

[0025] As shown in Figures 3 to 5, the outlet end 14 of the runner blade 12 is oriented toward the downstream side in the flow direction. Therefore, the thickness of the outlet end 14 decreases from the inlet end 13 side toward the outlet end 14 side. The inclined portion θ is formed in such a way. The thickness referred to here is the pressure from the water on the runner blade 12. This refers to the thickness between the receiving surface and its opposite surface. The exit end 14 of the runner blade 12 is The surface (pressure surface 12P) that receives pressure from the inflowing water during the operation of the Lancis-type turbine 1. On the negative pressure surface (negative pressure surface 12S) opposite to the flow direction, the outlet end The inclined portion θ is formed so that the thickness of 14 becomes thinner. For example, the exit of the runner blade 12 The end portion 14 is connected to the band-side inclination start point KB, which is defined on the negative pressure surface 12S of the runner blade 12. From the slope start reference line KL, which connects the slope start point KC on the downhill side, toward the outlet end in the flow direction downstream The inclined portion θ is formed so that the thickness of portion 14 becomes thinner. The starting point of the band-side inclination KB is, At the point where the band 11 and the runner blade 12 connect, the inclination begins toward the downstream side in the flow direction. This refers to the point where the crown-side inclination start point KC is where the crown 10 and the runner blade 12 are connected. This refers to the point where the lines converge and begin to slope downstream in the direction of flow. The slope start reference line KL, which connects the band-side slope start point KB and the crown-side slope start point KC, is At the outlet end 14 of the runner blade 12, the formation of an inclined portion θ toward the downstream side in the flow direction begins. This is a reference line, and it may be a straight line or a curved line. Furthermore, the inclined portion θ referred to here may be a straight line or a curved line. It may also be a slope.

[0026] Furthermore, the outlet end 14 of the runner blade 12 according to the first embodiment is the outlet end intermediate portion 14A It has an outlet end band-side thickened portion 14B and an outlet end crown-side thickened portion 14C. ru.

[0027] The outlet end intermediate portion 14A is the intermediate part of the outlet end 14, and is on the outlet end band side. This is the portion located between the thick-walled portion 14B and the thick-walled portion 14C on the crown side of the outlet end. The intermediate section 14A, when its exit end is defined as the exit end reference line 14L, is the starting point of the incline. This is the area defined by line KL and the exit end reference line 14L. The exit end intermediate section 14A is From the starting reference line KL towards the exit end reference line 14L (towards the downstream side in the flow direction) A sloping section θ is formed so that the thickness of 14A in the middle of the mouth end becomes thinner. The exit end reference line 14L may be a straight line or a curve. That's fine.

[0028] The thickened portion 14B on the band side of the outlet end is located on the band 11 side of the outlet end 14, This is the part that connects to section 11. The thickened section 14B on the exit end band side is connected to the inclination start reference line KL. This is the area defined by the exit end reference line 14L. The thickness is formed to be greater than the middle section 14A of the outlet end. Outlet end band side The thickened section 14B extends from the inclination start reference line KL toward the outlet end reference line 14L (downstream in the flow direction). (Facing the side) The thickness of the thickened portion 14B on the exit end band side is reduced by forming an inclined portion θ. The thickened portion 14B on the outlet end band side is provided with an extension portion 20 on the outlet end band side.

[0029] The exit end band-side extension 20 is located on the side of the exit end 14 that is on the band 11 side. This is a portion that is provided to protrude downstream in the flow direction from the thickened portion 14B on the band side. In other words, the exit end band-side extension 20 is located on the side of the exit end 14 that is on the band 11 side. The portion is provided to protrude downstream in the flow direction relative to the outlet end reference line 14L. That is the case.

[0030] Furthermore, the exit end band side extension 20 has an exit end band side connection point 21 and an exit end band At the location defined by the side thickness inflection point 22 and the exit end band side extension connection point 23 Yes. The exit end band-side connection point 21 is located on the band 11 defined on the exit end reference line 14L. This refers to the point where the runner blade 12 is joined. The exit end band-side thickness inflection point 22 is The outlet end intermediate section 14A and the outlet end band side thickened section 14 are defined on the mouth end reference line 14L This refers to the point where the thickness changes between B and the other end. The exit end band-side extension joint point 23 is the exit The band 11 and the runner blade 12 are connected, with the band 11 located downstream in the flow direction from the end reference line 14L. It refers to the endpoints that meet. That is, the exit end band side extension 20 is the exit end band side Joint point 21 and the thickness inflection point 22 on the outlet end band side to the extension joint point 2 on the outlet end band side This is a part that is designed to protrude downstream in the direction of flow, so as to connect to point 3.

[0031] Furthermore, the exit end band-side extension 20 extends from the exit end reference line 14 to the exit end band-side extension Thickness of the outlet end band-side extension 20 toward the long joint point 23 (towards the downstream side in the flow direction) A sloping portion θ is formed so that it becomes thinner. This sloping portion θ is the thicker portion on the exit end band side. It is formed to match the inclined portion θ formed in 14B. That is, the thickness on the exit end band side. The flesh section 14B and the exit end band-side extension 20 extend from the inclination start reference line KL to the exit end band. Outlet end band side thickened portion 14 towards the extension joint point 23 (towards the downstream side in the flow direction) The inclined portion θ is formed such that the thickness of B and the extension portion 20 on the exit end band side becomes thinner. .

[0032] The thickened portion 14C on the crown side of the outlet end is located on the crown 10 side of the outlet end 14. This is the part that connects to the crown 10. The thickened portion 14C on the crown side of the outlet end is based on the inclination start reference. This area is defined by line KL and the exit end reference line 14L. The thickness of section 14C is formed to be thicker than the intermediate section 14A at the exit end. The thickened section 14C on the crown side extends from the inclination start reference line KL toward the exit end reference line 14L. (Facing downstream in the flow direction) The thickness of the thickened section 14C on the crown side of the outlet end is reduced by inclination. A section θ is formed. The thickened section 14C on the crown side of the exit end is the extended section on the crown side of the exit end 30 is provided.

[0033] The exit end crown-side extension 30 is located on the crown 10 side of the exit end 14. A portion provided to protrude downstream in the flow direction from the thickened portion 14C on the crown side of the mouth end. That is, the extension portion 30 on the crown side of the outlet end is the crown 10 of the outlet end 14. On that side, it is provided to protrude downstream in the flow direction relative to the outlet end reference line 14L. This is the part that was treated.

[0034] Furthermore, the exit end crown-side extension 30 has an exit end crown-side connection point 31, and an exit end crown The boundary is defined by the thickness inflection point 32 on the round side and the connection point 33 on the crown side extension of the exit end. This is the part. The outlet end crown side joint point 31 is defined on the outlet end reference line 14L. This refers to the point where the crown 10 and the runner blade 12 are joined. The thickness change on the crown side of the exit end. The turning point 32 is defined on the exit end reference line 14L, between the exit end intermediate section 14A and the exit end clamp. This refers to the point where the thickness changes between the thickened section 14C on the fin side and the exit end crown side extension. The coupling point 33 is located downstream of the outlet end reference line 14L in the flow direction from the crown 10. This refers to the endpoint where the runner blade 12 connects. In other words, the exit end crown side extension 3. 0 is from the exit end crown side joint point 31 and the exit end crown side thickness inflection point 32 to the exit The end crown-side extension joint point 33 is connected to the flow direction, and the extension protrudes toward the downstream side in the flow direction. It is a designated part.

[0035] Furthermore, the exit end crown-side extension 30 extends from the exit end reference line 14 to the exit end crown. Outlet end crown side extension 30 towards side extension joint point 33 (towards the downstream side in the flow direction) A sloping portion θ is formed so that the thickness becomes thinner. This sloping portion θ is the exit end crown. It is formed to match the inclined portion θ formed in the thickened side portion 14C. That is, the outlet end The thickened section 14C on the round side and the extended section 30 on the crown side of the exit end are from the inclination start reference line KL. Outlet end crown side extension joint point 33 (towards the downstream side in the flow direction) The thickness of the thickened section 14C on the wing side and the extended section 30 on the crown side of the outlet end are reduced by the inclined section. θ is formed.

[0036] Next, using Figure 4, the thickened portion 14B on the exit end band side and the extended portion 2 on the exit end band side are shown. Let's explain 0 further.

[0037] As shown in Figure 4, the thickened portion 14B on the band side of the exit end is on the inclination start reference line KL. The point where the thickness changes between the intermediate section 14A and the thickened section 14B on the exit end band side is the inclined opening. The starting reference line band-side thickness inflection points 24S and 24P are defined. The exit end band-side thickened section. 14B is the line segment connecting the thickness inflection points 24S and 24P on the band side of the slope start reference line, with a thickness of 2 From 4T, the line segment connecting the band-side inclination start point KBS and KBP is the thickness KBT, leading to the exit. The thickness of the thickened portion 14B on the end band side is formed to gradually increase. The thickness KBT at the starting point of the slope on the band side is the thickness at the thickness inflection point on the band side of the slope start reference line. It is formed to be thicker than 24T. Also, the exit end band side extension 20 is The line segment connecting the thickness inflection points 22S and 22P on the exit end band side is thickness 22T to the exit end The line segment connecting the band-side bonding points 21S and 21P forms the thickness 21T, which is the exit end band side. The thickness of the extension 20 is formed to gradually increase. That is, the exit end band side The thickness 21T at the joint is thicker than the thickness 22T at the thickness inflection point on the exit end band side. It is formed in such a way that it becomes like that.

[0038] Furthermore, the thickened portion 14B on the exit end band side has a negative pressure surface 12S with a reference line for the start of the inclination. From the end band thickness inflection point 24S toward the exit end band thickness inflection point 22S An inclined portion θ is formed such that the thickness of the side thickened portion 14B becomes thinner. That is, the outlet end The band-side thickened portion 14B extends from the thickness 24T at the band-side thickness inflection point of the inclination start reference line. The thickness 22T at the thickness inflection point on the band side of the mouth end is directed toward the thickened portion 14B on the band side of the outlet end. The inclined portion θ is formed so that the thickness gradually decreases. At this time, the thickness on the exit end band side The wall portion 14B has an inclined portion θ formed at an inclination angle θ1. Furthermore, the outlet end band side is thicker. Section 14B and the exit end band-side extension 20 have a band-side inclined opening on the negative pressure surface 12S. Starting point KBS, passing through exit end band side connection point 21S to exit end band side extension connection point 2 Towards 3S, the thickness of the thickened portion 14B on the outlet end band side and the extension portion 20 on the outlet end band side A sloping portion θ is formed so that it becomes thinner. That is, the thickened portion 14B on the exit end band side The extension 20 on the band side of the exit end extends from the thickness 24T at the band-side inclination start point to the exit end The thickness of the thickened portion 14B on the exit end band side gradually increases toward the thickness 21T at the joint point on the band side. A sloping section θ is formed so that it becomes thinner at each step, and the thickness at the exit end band-side connection point is 21T. The extension 2 on the exit end band side is directed toward the thickness 23T at the connection point of the extension on the exit end band side The inclined portion θ is formed so that the thickness of 0 gradually decreases. At this time, the exit end band The thickened side portion 14B and the extension portion 20 on the exit end band side are formed with an inclined portion θ at an inclination angle θ2. It is being done.

[0039] Note that the thickness inflection points 22S and 22P on the exit end band side and the connection of the extension portion on the exit end band side are also included. Thickness at the end face 20M of the exit end band-side extension 20 defined by points 23S and 23P The connection point is between the thickness 22T at the thickness inflection point on the exit end band side and the extension on the exit end band side. Even if the thickness 23T at the point is the same, it may also be different. It's okay if they match.

[0040] Furthermore, the inclination angles θ1 and θ2 are the thickness inflection points 22S and 22P on the exit end band side. From the plane defined by the inclination start reference line band-side thickness inflection points 24S and 24P to the exit end The band-side extension connection points 23S and 23P and the band-side inclination start points KBS and KBP define the boundaries. The angles may be the same across the defined surface, or they may be different angles. That's good too.

[0041] Furthermore, for example, the connection points 23S, 23P of the exit end band-side extension and the start of the band-side inclination. In the plane defined by points KBS and KBP, the thickened portion 14B on the exit end band side and the exit end The band-side extension 20 has the same inclination angle, but this is not limited to this case. The extension joint points 23S, 23P on the end side and the band-side joint points 21S, 21P on the exit end The defined surface, the exit end band-side connection points 21S, 21P, and the band-side inclination start point KB. The inclination angles may differ for each of the surfaces defined by S and KBP. In other words, the exit end band-side thickened portion 14B and the exit end band-side extended portion 20 are different It may also be an angle of inclination.

[0042] Thus, the extension portion 20 on the exit end band side is located at the position of the thickness inflection point 22 on the exit end band side. The shape is determined by the magnitude of the inclination angle.

[0043] Next, using Figure 5, the thickened portion 14C on the crown side of the exit end and the extension on the crown side of the exit end are shown. Let me explain section 30 further.

[0044] As shown in Figure 5, the thickened portion 14C on the crown side of the exit end is above the inclination start reference line KL. The point where the thickness changes between the end intermediate portion 14A and the exit end crown-side thickened portion 14C is the slope. The inflection points 34S and 34P of the crown-side thickness along the oblique start reference line are defined. The exit end crown. The thickened side portion 14C is formed by the line segment connecting the inclination start reference line crown side thickness inflection points 34S and 34P. The thickness KCT is the line segment connecting the crown-side inclination start points KCS and KCP, starting from the thickness 34T. The thickness of the thickened portion 14C on the crown side of the exit end gradually increases towards the exit end. In other words, the thickness KCT at the crown-side inclination start point is equal to the crown-side thickness of the inclination start reference line. It is formed to be thicker than the thickness 34T at the inflection point. Also, the exit end cl The extension 30 on the downside is the line segment connecting the thickness inflection points 32S and 32P on the crown side of the exit end. The line segment connecting the exit end crown-side joint points 31S and 31P from the thickness 32T is the thickness 31T. The thickness of the crown-side extension 30 at the exit end gradually increases towards the exit. In other words, the thickness 31T at the crown-side connection point of the exit end is the thickness change on the crown-side of the exit end. It is formed to be thicker than the 32T thickness at the curved point.

[0045] Furthermore, the thickened portion 14C on the crown side of the outlet end is located on the negative pressure surface 12S, along the inclination start reference line. From crown side thickness inflection point 34S toward exit end crown side thickness inflection point 32S The inclined portion θ is formed such that the thickness of the thickened portion 14C on the crown side becomes thinner. That is, The thickness of the crown-side thickened portion 14C at the exit end is determined by the thickness at the inflection point of the crown-side thickness of the reference line for the start of the inclination. From 34T towards the exit end crown side thickness inflection point of 32T, the exit end crown The inclined portion θ is formed so that the thickness of the thickened side portion 14C gradually decreases. The thickened portion 14C on the crown side of the mouth end has an inclined portion θ formed at an inclination angle θ3. The thickened portion 14C on the crown side of the mouth end and the extended portion 30 on the crown side of the outlet end are on the negative pressure surface 12S. Then, from the crown-side inclination starting point KCS, through the exit end crown-side connection point 31S to the exit End crown side extension joint point 33S and exit end crown side thickened portion 14C and exit An inclined portion θ is formed such that the thickness of the end crown-side extension portion 30 becomes thinner. The thickened portion 14C on the crown side of the outlet end and the extended portion 30 on the crown side of the outlet end are on the crown side From a thickness of 34T at the inclination start point to a thickness of 31T at the crown-side joint point at the exit end. A sloped portion θ is formed such that the thickness of the thickened portion 14C on the crown side of the exit end gradually decreases. From the thickness 31T at the crown-side joint point of the exit end to the extension joint point of the crown-side joint point of the exit end The thickness of the extension portion 30 on the crown side of the exit end gradually decreases towards the thickness 33T. A slanted portion θ is formed. At this time, the thickened portion 14C on the crown side of the outlet end and the outlet end The round-side extension 30 has an inclined portion θ formed at an inclination angle θ4.

[0046] Note that the thickness inflection points 32S, 32P on the crown side of the exit end and the extension portion on the crown side of the exit end The end face 30M of the exit end crown-side extension 30 is defined by the connection points 33S and 33P. The thickness is calculated from the thickness 32T at the thickness inflection point on the crown side of the exit end to the crown side of the exit end Even if the thickness 33T at the extension joint is the same, different thicknesses may be different. It may also be the case that it is a single unit.

[0047] Furthermore, the inclination angles θ3 and θ4 correspond to the thickness inflection points 32S and 32P on the crown side of the exit end. And from the surface defined by the inclination start reference line crown-side thickness inflection points 34S and 34P to the exit End crown-side extension connection points 33S, 33P and crown-side inclination start points KCS, KCP The angles may be the same across the plane defined by the same angle, or they may be different angles. That's fine.

[0048] Furthermore, for example, the connection points 33S, 33P of the exit end crown-side extension and the crown-side inclination In the plane defined by the starting points KCS and KCP, the thickened portion 14C on the crown side of the exit end and The exit end crown-side extension 30 has the same inclination angle, but this is not limited to this case. Joint points 33S, 33P on the crown side extension of the mouth end and joint point 31S on the crown side of the outlet end, The surface defined by 31P, and the exit end crown-side joint points 31S, 31P, and the crown When the planes defined by the lateral inclination start points KCS and KCP have different inclination angles. It may also be the case that the outlet end band-side thickened portion 14B and the outlet end band-side extended portion 2 The inclination angle may be different for each of the zeros.

[0049] Thus, the extension portion 30 on the crown side of the exit end is at the thickness inflection point 32 on the crown side of the exit end. The shape is determined by the position and the magnitude of the inclination angle.

[0050] As described above, according to the runner blade 12 of the first embodiment, the exit end 14 of the runner blade 12 The above-mentioned outlet end band-side extension 20 and outlet end crown-side extension 30 are formed therein. This reduces the load on each runner blade due to water pressure. As a result, This ensures the strength of the exit end 14 of the runner blade 12 and reduces the risk of damage to the runner 5. It can reduce the amount of noise.

[0051] Furthermore, according to the runner blade 12 of the first embodiment, the exit end 14 of the runner blade 12 By forming the aforementioned inclined portion θ, the exit end 14 of the runner blade 12 gradually becomes thinner. , resulting in an asymmetrical shape. As a result, karma occurs in the wake of the outlet end 14 of the runner blade 12. This can suppress the generation of Karman vortices and reduce the loss of runner 5 associated with the generation of Karman vortices. It is possible.

[0052] In other words, according to the runner blade 12 of the first embodiment, the exit end of the runner blade 12 This allows for maintaining strength 14 while reducing runner 5 losses.

[0053] In the first embodiment, the exit end band-side extension 20 is integrated with the runner blade 12. The explanation uses examples of when it can be done, but it is not limited to these cases. For example, the exit end van The extension portion 20 on the side is added to the existing runner blade by bolts, welding, etc. They may be combined. The same shall apply to subsequent embodiments.

[0054] Furthermore, in the first embodiment, the exit end crown-side extension 30 is integrated with the runner blade 12. The example given illustrates the case in which it is formed, but it is not limited to this case. For example, the outlet end The runner-side extension 30 is additionally provided to the existing runner blade by bolts, welding, etc. This may also be the case. The same shall apply to subsequent embodiments.

[0055] Furthermore, in the first embodiment, the runner blades 1 during the operation of the Francis turbine 1 At the exit end 14 of 2, there is an exit end band-side extension 20 and an exit end crown-side extension 30 The following example illustrates the case in which these are provided and an inclined portion θ is formed on the negative pressure surface side. However, not only when the turbine is in operation, but also at the end of the runner blade 12 on the downstream side in the direction of flow Furthermore, an extension portion on the band side of the outlet end and an extension portion on the crown side of the outlet end are provided, and these Any configuration in which an inclined portion is formed on the negative pressure side is acceptable. For example, the Francis turbine 1 Outlet end of runner blade 12 during pumping operation (Inlet end of runner blade 12 during turbine operation) The mouth end 13) is provided with an outlet end band-side extension and an outlet end crown-side extension. In addition, these configurations may include inclined sections on the negative pressure side.

[0056] (Second Embodiment) Next, we will further explain the inclination angles θ1 to θ4 using Figure 6. This is a schematic diagram created based on the flow analysis results. The following sections describe the differences from the first embodiment. This will be explained, and parts similar to those in the first embodiment will be given the same figure numbers and explained accordingly. Omitted.

[0057] In Figure 6, the horizontal axis shows the angle values ​​from tilt angle θ1 to tilt angle θ4, and the vertical axis shows the angle. This shows the relative number of runner blades 12 that generate Luman vortices.

[0058] As shown in Figure 6, when the inclination angle is 0 degrees (when no inclined portion θ is formed), The relative number of runner blades that generate Luman vortices is 1.0. That is, the inclination angle is 0. If the temperature is such that a large number of Karman vortices are generated in the wake of the runner blade 12.

[0059] On the other hand, as the inclination angle increases, the relative position of the runner vane from which Karman vortices are generated The number of layers decreases. For example, if the tilt angle is 6 degrees, the runner that generates Karman vortices... The relative number of feathers is 0.33. Also, when the inclination angle is 30 degrees, Karma The relative number of runner blades that generate vortices approaches 0.0. That is, the larger the inclination angle, As the temperature decreases, the generation of Karman vortices in the wake of the runner blade 12 is suppressed.

[0060] Here, the inventor determined that the relative number of runner vanes from which Karman vortices are generated is 0.33 or less. In this case, the inclined portion θ formed at the outlet end 14 of the runner blade 12 suppresses the generation of Karman vortices. It was determined that this contributes to the effect of tilting from the tilt angle θ1. It was determined that it is desirable for the angle θ4 to be set in the range of 6 to 30 degrees. (See Figure 6) As shown, when the angle from inclination angle θ1 to inclination angle θ4 exceeds 6 degrees, the inclination angle and karma This is because the slope of the line showing the relationship with the vortex is gentle. That is, the inclination angle θ1 It is thought that when the inclination angle θ4 exceeds 6 degrees, the generation of Karman vortices is stably suppressed. It is a treasure. Note that the angles from inclination angle θ1 to inclination angle θ4 are 6 degrees to 30 degrees. Even if the angles are the same within the range of degrees, they may be different angles within the range of 6 to 30 degrees. It may be acceptable in some cases.

[0061] As described above, according to the runner blade 12 of the second embodiment, the exit end 14 of the runner blade 12 A sloping portion θ is formed in the range of 6 to 30 degrees relative to it. As a result, the same as in the first embodiment. In addition to exhibiting various effects, the Karman effect occurs in the flow downstream of the outlet end 14 of the runner blade 12. This can more effectively suppress the generation of vortices and reduce the loss of runner 5 associated with the generation of Karman vortices. It can be reduced more effectively.

[0062] (Third embodiment) Next, using Figure 7, the thickness inflection point on the band side of the slope start reference line at the slope start reference line KL. The positions of 24 and the crown-side thickness inflection point 34 of the inclination start reference line will be explained further. Also, using Figure 7, the thickness 22T at the thickness inflection point on the exit end band side and the exit end band The thickness 23T at the joint point of the extension on the do side, and at the thickness inflection point on the crown side of the exit end Regarding the thickness 32T and the thickness 33T at the joint point of the extension on the crown side of the exit end, further Let me explain. Figure 7 is a comparison table created based on the flow analysis results. From here on, the first implementation will be described. The form and differences from the second embodiment will be described, and the first and second embodiments will be described. For parts that are similar in appearance to the installation form, the same drawing number is used, and the explanation is omitted.

[0063] In Figure 7, for each sample, the inclination angle, the relative position of the thickness inflection point, the thickness ratio at the end, The cumulative damage rate and observation results of Karman vortices are shown.

[0064] The relative position of the thickness inflection point is defined as the band-side inclination start point KB being 0.0, and the crown-side inclination start point When point KC is set to 1.0 (with the band-side slope start point KB as the origin), the slope start base The relative position of the thickness inflection point 24 on the band side of the reference line for the start of the slope in the direct line KL, or the cloud When the starting point of the inclination on the crown side KC is 0.0 and the starting point of the inclination on the band side KB is 1.0 (crown side) (When the starting point of the slope KC is taken as the origin) The starting point of the slope reference line KL This refers to the relative position of the thickness inflection point 34 on the Un side. In other words, the relative position of the thickness inflection point and This is the exit end when the band-side slope start point KB is taken as the origin at the slope start reference line KL. The area in which the thickened portion 14B on the band side and the extended portion 20 on the exit end band side are provided is defined. Position, or the thickness of the crown side at the exit end when the crown side inclination start point KC is taken as the origin. The position that defines the range in which part 14C and the exit end crown-side extension 30 are provided. say.

[0065] The thickness ratio at the end refers to the ratio of the thickness of the middle section 14A at the exit end to the thickness on the slope start reference line KL. , the end face 20M of the exit end band-side extension 20 or the end face of the exit end crown-side extension 30 This refers to the ratio of the thickness to 30M. Specifically, in the third embodiment, the slope start reference line... The thickness 24T of the thickness inflection point 24 on the band side, and the thickness 2 of the thickness inflection point 22 on the exit end band side. The ratio of the thickness 23T of 2T and the extension joint point 23 on the exit end band side, or the inclined starting base The thickness inflection point 34T of the crown side thickness inflection point 34 of the direct line, and the thickness inflection point 3 of the crown side thickness at the exit end This refers to the ratio of the thickness 32T of part 2 to the thickness 33T of the joint point 33 on the crown side extension of the exit end. In other words, the thickness ratio at the end is the thickness 24 of the thickness inflection point 24 on the band side of the inclination start reference line. The ratio of the thickness of the end face 20M of the exit end band-side extension 20 to T, or the start of the inclination. The extension portion 30 on the crown side of the exit end relative to the thickness 34T of the reference line crown side thickness inflection point 34 This refers to the ratio of the thickness of the 30M end face.

[0066] The cumulative damage rate is determined by the bending moment and other loads received by the runner blades 12 from the water that flows into them. This refers to the cumulative damage rate of the exit end 14. Here, the cumulative damage rate must be 1.0 or less. That is preferable.

[0067] Sample 1 shows the case where the tilt angle is 0 degrees as a comparative example, and Sample 2 and beyond The example below shows a case where the inclination angle is 6 degrees. The details described later are as follows: This applies not only when the inclination angle is 6 degrees, but also when the inclination angle is in the range of 6 to 30 degrees. In the second embodiment (in Figure 6), the inclination angle is 6 degrees to 3 degrees. This is because we have already shown that the generation of Karman vortices is suppressed as the temperature approaches 0 degrees.

[0068] In Sample 1, the inclination angle is 0 degrees, and the relative position of the thickness inflection point is 0.0 (no inflection point). Under the condition that the thickness ratio at the edge is 1.0 (no slope θ), a large number of Karman vortices are generated. Furthermore, due to the large number of Karman vortices generated, there is no data on the cumulative damage rate.

[0069] In Sample 2, the inclination angle is 6 degrees, the relative position of the thickness inflection point is 0.2, and the thickness ratio at the end is Under the condition of 0.33, the cumulative damage rate is 3.39, and a small number of Karman vortices are generated. there was.

[0070] In Sample 3, the inclination angle is 6 degrees, the relative position of the thickness inflection point is 0.3, and the thickness ratio at the end is Under the condition of 0.33, the cumulative damage rate is 2.31, and a small number of Karman vortices are generated. there was.

[0071] In Sample 4, the inclination angle is 6 degrees, the relative position of the thickness inflection point is 0.3, and the thickness ratio at the end is Under the condition of 0.5, the cumulative damage rate was 0.64, and hardly any Karman vortices were generated. It wasn't there.

[0072] When comparing Sample 2 and Sample 3 here, the relative position of the thickness inflection point is 0.2 By setting it to 0.3, the cumulative damage rate decreased from 3.39 to 2.31. Also, Sun When comparing pull 3 and sample 4, assuming the relative position of the thickness inflection point is 0.3, the end is By changing the thickness ratio from 0.33 to 0.5, the cumulative damage rate decreased from 2.31 to 0.64. This cumulative injury rate of 0.64 meets the target value for cumulative injury rate (less than 1.0). Furthermore, in this case, it has been found that the generation of Karman vortices can be effectively suppressed. ru.

[0073] Therefore, the inventors hope that the relative position of the thickness inflection point will be set to 0.3 or greater. The inventor determined that the band-side inclination start line KL is correct. From point KB to a point that is 30% or more away, the thickened portion 14B on the exit end band side and It was determined that it is desirable to provide an extension 20 on the exit end band side. Furthermore, the inventors stated that A point on the slope start reference line KL that is located at a position of 30% or more from the crown-side slope start point KC. The thickened portion 14C on the crown side of the outlet end and the extended portion 30 on the crown side of the outlet end are provided within the specified range. We determined that it would be desirable to be kicked.

[0074] Furthermore, the inventor stated that it is desirable for the thickness ratio of the edges to be set to 0.5 or more and less than 1.0. The inventor determined that the thickened portion 14B on the outlet end band side and the outlet end band side The extension 20 has an exit end relative to the thickness 24T of the thickness inflection point 24 on the band side of the inclination start reference line. The ratio of the thickness of the end face 20M of the band-side extension 20 is in the range of 0.5 or more and less than 1.0. It was determined that it is desirable for an inclined portion θ to be formed at the outlet end. The thickened section 14C on the inner side and the extension 30 on the crown side of the exit end have a reference line for the start of the inclination on the crown side. The thickness of the end face 30M of the exit end crown-side extension 30 relative to the thickness 34T of the thickness inflection point 34. It is desirable that the inclined portion θ be formed such that the ratio is in the range of 0.5 or more and less than 1.0. I made that judgment.

[0075] Note that the thickness inflection point 24 on the band side of the slope start reference line and the thickness inflection point on the crown side of the slope start reference line The relative positions of each of the 34 thickness inflection points are the same value within the range of 0.3 or greater. It may be 0.3 or higher, and it may also be a different value within the range of 0.3 or higher.

[0076] Furthermore, the thickness 22T of the thickness inflection point 22 on the exit end band side and the connection point of the extension on the exit end band side The thickness ratio at each end of the 23T thickness is the same, within the range of 0.5 to less than 1.0. It may also be a value, and if it is a different value within the range of 0.5 or more and less than 1.0 It may be. Also, the thickness 32T of the inflection point 32 on the crown side of the exit end and the exit end crown The thickness ratio of each end of the thickness 33T of the extension joint point 33 on the n side is 0.5 or more and less than 1.0 It is also acceptable for the values ​​to be the same within the range where this occurs, and for the values ​​to be different within the range of 0.5 or more and less than 1.0. It may also be a value.

[0077] As described above, according to the runner blade 12 of the third embodiment, the exit end 14 of the runner blade 12 In this case, the thickness inflection point 24 on the band side of the slope start reference line and the thickness inflection point on the crown side of the slope start reference line The relative positions of the thickness inflection points at point 34 are set to be 0.3 or greater. Furthermore, the thickness of the band on the exit end side relative to the thickness 24T of the thickness inflection point 24 on the band side of the reference line for the start of the slope The thickness 22T at the inflection point 22 and the thickness 23T at the connection point 23 of the extension part on the exit end band side, respectively The thickness ratio at the end is set to be between 0.5 and less than 1.0. Furthermore, the inclination starts The thickness inflection point 34T of the crown side thickness inflection point 34 of the reference line crown side, relative to the thickness 34T of the exit end crown side thickness inflection point 3 The thickness 32T of part 2 and the thickness 33T of the joint point 33 on the crown side extension of the exit end, at each end The thickness ratio is set to be between 0.5 and less than 1.0. As a result, the first embodiment And exhibits the same effects as in the second embodiment, and the outlet end 1 of the runner blade 12 While ensuring strength 4, Karman vortices are generated in the wake behind the outlet end 14 of the runner blade 12. This can more effectively suppress the generation of Karman vortices and more effectively reduce the loss of runner 5 associated with the generation of Karman vortices. It can be reduced effectively.

[0078] Although several embodiments of the present invention have been described, these embodiments are presented as examples only. Therefore, it is not intended to limit the scope of the invention. These novel embodiments are It can be implemented in various other forms, and without departing from the spirit of the invention, various ministries These embodiments and their variations can be roughly replaced, modified, and combined. The scope and gist of the invention, as well as the scope of the claims, of the invention and its equivalents. It is included in. [Explanation of Symbols]

[0079] 1...Francis turbine, 2...Casing, 3...Stay vane, 4...Guide vane, 5...L 6... Main shaft, 7... Generator, 8... Suction tube, 10... Crown, 11... Band, 12... Nna blade, 12P...pressure side, 12S...negative pressure side, 13...inlet end, 14...outlet end, 14A ...Middle section of the exit end, 14B...Thickened section on the band side of the exit end, 14C...Thickened section on the crown side of the exit end Section, 14L... Exit end reference line, 20... Exit end band side extension, 20M... End face, 21... Exit End band side connection point, 21T...thickness, 22...end band side thickness inflection point, 22T...thickness , 23... Connection point of the extension on the exit end band side, 23T... Thickness, 24... Inclined start reference line band Side thickness inflection point, 24T...thickness, 30...exit end crown side extension, 30M...end face, 31... Exit end crown side joint point, 31T...thickness, 32...exit end crown side thickness inflection point, 32 T...thickness, 33...connection point of the crown-side extension at the exit end, 33T...thickness, 34...inclination start reference point Line crown side thickness inflection point, 34T...thickness, KB...band side slope start point, KBT...thickness, K C...Crown-side inclination start point, KCT...Thickness, KL...Inclination start reference line

Claims

1. The water flowing into the runner vanes located between the crown and the band is positioned on the downstream side in the direction of flow. Of the outlet ends of the runner blades, the one protruding from the band side toward the downstream side in the flow direction. An extension portion on the exit end band side is provided for this purpose, Of the aforementioned outlet ends, one is provided to protrude from the crown side toward the downstream side in the flow direction. The extended portion on the crown side of the exit end, Equipped with, The negative pressure surface of the extension on the band side of the outlet end and the extension on the crown side of the outlet end is Water is characterized by having a sloped section that becomes thinner towards the downstream side in the direction of flow. A runner for a power machine.

2. The aforementioned outlet end is, The intermediate part of the outlet end, The intermediate portion of the outlet end and the band are connected, and the direction from the intermediate portion of the outlet end toward the band The thickened portion on the exit end band side is formed to increase in thickness, The outlet end intermediate portion and the crown are connected, and the outlet end intermediate portion to the crown The thickened portion on the crown side of the exit end is formed to increase in thickness towards the end, Includes, The thickened portion on the outlet end band side has an outlet end band that protrudes downstream in the flow direction. Side extensions are provided, The thickened portion on the crown side of the outlet end is configured to protrude downstream in the flow direction. An extension section is provided on the side. The outlet end intermediate portion, the outlet end band side thickened portion, the outlet end crown side thickened portion, The negative pressure surface of the extension on the band side of the outlet end and the extension on the crown side of the outlet end is A feature of this product is that it has a sloped section that becomes thinner towards the downstream side in the direction of flow. A runner for the hydraulic machine described in item 1.

3. The inclined portion is characterized by being formed at an inclination angle of either 6 degrees or 30 degrees. A runner for a hydraulic machine according to claim 1 or claim 2.

4. The inclined portion is the point where the band and the runner blade are joined, on the downstream side in the flow direction. The point at which the inclination begins toward and the point at which the crown and the runner blades are joined From the reference line for the start of the inclination, which connects the point where the inclination begins toward the downstream side in the flow direction, It is formed so that the thickness decreases towards the downstream side. The thickness on the inclination start reference line at the middle portion of the outlet end, the outlet end van The thickness ratio at the end face of the extension on the side is in the range of 0.5 or more and less than 1.

0. The thickness on the slope start reference line at the middle portion of the outlet end, The thickness ratio at the end face of the extension on the left side is in the range of 0.5 or more and less than 1.

0. A runner for a hydraulic machine as described in claim 3.

5. The inclined portion is the point where the band and the runner blade are joined, on the downstream side in the flow direction. The band-side inclination start point where the inclination begins toward the crown and the runner blades are coupled. The point connecting the crown-side inclination start point, which begins to incline toward the downstream side in the flow direction, is It is formed such that the thickness decreases towards the downstream side in the flow direction from the reference line where the slope begins. The extension portion on the band side of the exit end starts to slope on the band side along the slope start reference line. The range extends to points that are more than 30% away from the point. The extension portion on the crown side of the exit end is inclined on the crown side along the inclination start reference line. The feature is that it is provided up to a point that is 30% or more from the starting point. Runner for the hydraulic machine described in 3.

6. A hydraulic machine characterized by comprising a runner for a hydraulic machine as described in claim 1 or claim 2.

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