JP5341782B2 - Hydraulic machine and its runner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic machine capable of suppressing the generation of a cavity region even upon low-output operation, reducing a loss increase in a runner and the vibration by whirl to achieve high efficiency and low vibration, and suppressing the increase of a production cost to contribute to the improvement of economical efficiency, and to provide the runner. <P>SOLUTION: A rib 21 mounted on an inner surface of a runner cone 1 is provided inclining in an opposite direction to a rotating direction of runner 15 from bottom up. A pumping action is generated in the runner cone 1 when the rib 21 rotates along with the rotation of runner 15 since the rib 21 inclines in the radial direction of runner 15, and a suction flow is caused from a lower end of runner cone 1 upward. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a hydraulic machine such as a Francis turbine, and more particularly, to a hydraulic machine and a runner thereof for reducing hydraulic pulsation.

  In recent years, environmental awareness has increased, and hydroelectric power generation systems with low environmental impact have attracted widespread attention. Moreover, hydroelectric power generation systems are more economical and stable than other power generation systems that use clean and renewable energy. Such hydroelectric power generation systems have different requirements (flow rate and head) depending on the topographic conditions of the construction site. Therefore, various types of hydraulic machines incorporated in the system have been developed according to the requirements.

  Hereinafter, the configuration of a Francis turbine, which is a representative hydraulic machine, will be described with reference to FIGS. 24 and 25. The longitudinal sectional view of FIG. 24 shows a general structure of a Francis turbine. As shown in FIG. 24, the Francis turbine is provided with a spiral casing 12 or the like.

  A stay vane 13 is integrally fixed inside the casing 12, and a guide vane 14 whose opening degree can be adjusted is provided. A runner 15 that receives a water flow is rotatably disposed inside the guide vane 14. A main shaft 16 is attached to the upper center of the runner 15, and a generator 17 is connected to the main shaft 16. Further, below the runner 15, a suction pipe 18 is provided for sucking out the water that has passed through the runner 15 to the discharge channel side.

  The runner 15 is a main member of the Francis turbine, and a disc-shaped runner crown 3 is provided at the upper portion and a runner band 5 is provided at the lower portion. A plurality of runner blades 4 are arranged in a row in the circumferential direction between the runner crown 3 and the runner band 5.

  In the Francis turbine as described above, during the power generation operation, water flows from the casing 12, passes through the stay vane 13 and the guide vane 14, and flows into the runner 15. The runner 15 is rotationally driven in response to this water flow. The rotational force of the runner 15 is transmitted to the generator 17 via the main shaft 16, and the generator 17 is driven. On the other hand, the water that has driven the runner 15 flows out to the water discharge channel through the suction pipe 18. During the actual operation of the Francis turbine, the amount of power generated by the generator 17 is controlled by adjusting the rotational force of the runner 15 by adjusting the opening of the guide vane 14.

  In the Francis turbine, increased loss and water pressure pulsation are known as problems occurring on the exit side of the runner 15. First, the loss increase will be described. When the water that has passed through the runner 15 flows from the outlet of the runner 15 to the suction pipe 18, the flow path suddenly expands as soon as it flows into the suction pipe 18. Loss increases due to this rapid expansion of the flow path.

  As a countermeasure against such an increase in loss, a conical runner cone 1 protruding in the direction of the suction pipe 18 (downward in FIG. 24) is formed at the lower end of the rotation shaft center of the runner crown 3. Since the runner cone 1 has a curved surface that curves in the center direction of the runner 15, the water inside the runner 15 flows out while being squeezed in the center direction, and when the water flows into the suction pipe 18, the rapid expansion of the flow path can be suppressed. it can. A rib 2 is attached to the inner peripheral side of the runner cone 1 so as to increase the strength in the circumferential direction so that the runner cone 1 is not deformed by receiving a strong water pressure.

  Next, water pressure pulsation, which is another problem that occurs on the exit side of the runner 15, will be described. On the outlet side of the runner 15, a swirling flow having a rotation component in the same direction as the rotation direction of the runner 15 is generated. The swirling flow generates vortices called whirls 19. The whirl 19 swings with the central axis of the suction pipe 18 as a vortex core, and the suction pipe 18 undergoes water pressure fluctuation, that is, water pressure pulsation.

  In particular, as shown in FIG. 25, when the dead water region 20 where water does not flow is formed near the center of the runner 15, the whirl 19 sways around the dead water region 20, which occurred in the suction pipe 18. Water pressure pulsation increases. As a result, in some cases, the vibration may be so large that the entire water wheel is shaken.

  As a measure for reducing the water pressure pulsation by the whirl 19, there is a method of stabilizing the whirl 19 by injecting air from the upper portion of the suction pipe 18 or the main shaft 16. In addition, a method of suppressing the whirl 19 by preventing the swirling flow from occurring by providing fins on the inner wall of the suction pipe 18 has been proposed.

  By the way, if the dead water area | region 20 is large, the flow of the water in the runner blade | wing 4 will be biased by that much. That is, the dead water region 20 not only increases the vibration caused by the whirl 19 but also causes an increase in loss inside the runner 15. Here, the principle of generation of the dead water region 20 will be described with reference to FIG.

  As shown in FIG. 25, the flow of water inside the runner 15 is biased toward the inner periphery of the runner 15 at the time of high output of the Francis turbine, based on the flow of water at the design point indicated by the solid arrow (one point). Chain line arrow). For this reason, there is a low possibility that water flows near the center of the runner 15 and the dead water region 20 is formed below the center of the runner 15.

  On the other hand, at the time of low output of the Francis turbine, it is biased toward the outer peripheral side of the runner 15 with reference to the flow of water at the design point (dotted arrow). For this reason, at the time of low output, water hardly flows near the center of the runner 15, and a dead water region 20 is formed below the center of the runner 15.

  Francis turbines are not only operated on the high output side, but also play a large role in load adjustment and are frequently operated on the low output side. Therefore, there is a possibility that the dead water region is frequently generated in proportion to the frequency of operation on the low output side. Therefore, in Francis turbines, it is important to prevent the occurrence of dead water areas and improve the efficiency on the low output side.

  For example, Patent Document 1 has been proposed as a conventional technique for improving the efficiency on the low output side. In the Francis turbine of Patent Document 1, auxiliary vanes having a shape on the extended line of the runner vanes are provided inside the runner cone. The runner cone is configured to move up and down according to the driving state.

  In such a conventional technique, at the time of low output of the Francis turbine, auxiliary blades are taken out from the runner cone and exposed to the water surface side. It has been proposed to prevent a biased flow toward the outer peripheral side because the auxiliary vane exposed on the water surface side draws the water flow in the inner peripheral direction of the runner.

JP-A-4-72468

  However, the following problems are pointed out in the technique of the above-mentioned Patent Document 1. That is, Patent Document 1 is characterized in that an auxiliary blade that moves up and down is newly attached as a member that supplements the runner blade. At this time, the auxiliary blade is a member that plays a role as a blade even if it is auxiliary, and must exhibit the effect as the water wheel blade at the time of low output. Therefore, the shape of the auxiliary blade needs to be exactly on the extended line of the runner blade, and high accuracy is required in manufacturing. As a result, with the technique of the above-mentioned Patent Document 1, the production cost is likely to increase, and the economic efficiency, which is the merit of the hydroelectric power generation system, is reduced.

  The present invention has been proposed in view of such conventional circumstances, and the purpose thereof is to suppress the occurrence of a dead water region even during low-power operation, and due to increased loss inside the runner and the whirl. Provided are a hydraulic machine and its runner that reduce vibrations and achieve high efficiency and low vibration, and suppress an increase in production cost and contribute to improvement in economic efficiency.

  In order to achieve the above object, the present invention is a runner rotatably incorporated in a hydraulic machine, wherein a runner crown is provided at the upper portion and a runner band is provided at the lower portion, and between the runner crown and the runner band, In a runner of a hydraulic machine in which a plurality of runner blades are arranged in a row in the circumferential direction, a conical runner cone protruding downward is formed on the central axis of the runner crown, and a rib is installed inside the runner cone. The rib is inclined in the counter-rotating direction of the runner from the lower end side toward the upper end side, from the inner side toward the outer side, or from the lower end side toward the upper end side, while moving from the inner side toward the outer side. To do.

  According to the hydraulic machine and its runner of the present invention, it is possible to suppress the generation of dead water area even during low-power operation, and to achieve high efficiency and low vibration, and without adding new members. Costs can be suppressed and the economy can be improved.

1 is a partially enlarged longitudinal sectional view of a first embodiment according to the present invention. (A) is a view on arrow R in FIG. 1, and (b) is a view on arrow Z in FIG. The schematic diagram of the water flow inside the runner of 1st Embodiment. It is a figure of the prior art example for comparing with 1st Embodiment, Comprising: (a) is R arrow directional view of FIG. 25, (b) is Z arrow directional view of FIG. It is the figure of the runner in the modification of 1st Embodiment, Comprising: The partially expanded front view which looked at the part containing a rib from the rotation center axis | shaft of a runner to the radial direction. It is a figure of the runner in the modification of 1st Embodiment, Comprising: The partially expanded plan view of the part containing a rib. The partially expanded longitudinal cross-sectional view of 2nd Embodiment which concerns on this invention. (A) is a view on arrow R in FIG. 6, and (b) is a view on arrow Z in FIG. The schematic diagram of the water flow inside the runner of 2nd Embodiment. It is the figure of the runner in the modification of 2nd Embodiment, Comprising: The partially expanded front view which looked at the part containing a rib from the rotation center axis | shaft of a runner to the radial direction. It is a figure of the runner in the modification of 2nd Embodiment, Comprising: The partial enlarged plan view of the part containing a rib. It is a figure of the runner in the modification of 2nd Embodiment, Comprising: The partial enlarged plan view of the part containing a rib. The partially expanded longitudinal cross-sectional view of 3rd Embodiment which concerns on this invention. The schematic diagram of the water flow inside the runner of 3rd Embodiment. The partially expanded longitudinal cross-sectional view (at the time of a low output driving | operation) of 4th Embodiment which concerns on this invention. The schematic diagram of the water flow inside the runner of 4th Embodiment. The partially expanded longitudinal cross-sectional view (at the time of a high output driving | operation) of 4th Embodiment which concerns on this invention. The partially expanded longitudinal cross-sectional view of 5th Embodiment which concerns on this invention. The Z arrow line view of FIG. The schematic diagram of the water flow inside the runner of 5th Embodiment (at the time of low output driving | operation). The Z arrow line view of FIG. The schematic diagram of the water flow inside the runner of the fifth embodiment (during high-power operation). The Z arrow line view of FIG. A sectional view of a general Francis turbine. The partially expanded longitudinal cross-sectional view of the runner in a common Francis turbine.

(1) First Embodiment [Configuration]
Hereinafter, a first embodiment to which a hydraulic machine liner according to the present invention is applied will be described with reference to FIGS. 1 is a partially enlarged longitudinal sectional view of the first embodiment, FIG. 2 is a partial sectional view of a runner for showing the shape of a rib 21, and (a) in the upper stage is a view taken in the direction of arrow R in FIG. 1. The lower part (b) is a view in the direction of arrow Z in FIG. In addition, as a hydraulic machine in 1st Embodiment, the Francis turbine is employ | adopted similarly to the prior art example shown in FIG.24, FIG.25, About the same member as a prior art example, the same code | symbol is attached | subjected and description is carried out. Omitted.

  The structural feature of the first embodiment is the configuration of the rib 21 attached to the inner peripheral surface of the runner cone 1. The rib 21 is provided so as to incline in the direction opposite to the rotation direction of the runner 15 from the lower side to the upper side in the arrow R in the radial direction from the rotation center axis of the runner 15 (FIG. 2A). reference).

  Further, the rib 21 has a shape extending radially in the radial direction of the runner 15 in the arrow Z from the upper end of the runner cone 1 (see FIG. 2B). The rib 21 plays a role as a strength member of the runner cone 1 like the conventional rib 2.

[Function and effect]
In the runner 15 having the ribs 21 as described above, since the ribs 21 are inclined in the radial direction of the runner 15, when the ribs 21 are rotated along with the rotation of the runner 15, a pump action is generated inside the runner cone 1. That is, as shown in FIG. 3, a suction flow (solid arrow A) is generated from the lower end of the runner cone 1 upward.

  As a result, the water flow along the outer periphery of the runner cone 1 out of the water flow passing through the runner blades 4 is affected by the suction flow inside the runner cone 1, gets over the runner cone 1 and is drawn to the vicinity of the center of the lower portion of the runner 15 ( (Indicated by solid arrow B). For this reason, the water flow that has passed through the runner blades 4 is not biased toward the outer peripheral side of the runner 15, and the size of the dead water region 20 can be suppressed.

  Here, as a comparative example of the first embodiment, the shape of the conventional rib 2 will be described with reference to FIGS. 4A is a view as viewed from the arrow R in FIG. 25, and FIG. 4B is a view as viewed from the arrow Z in FIG. As shown in FIGS. 4 (a) and 4 (b), the conventional rib 2 does not have a shape inclined in both the radial direction and the height direction of the runner 15.

  For this reason, the rib 2 does not affect the water flow inside the runner cone 1. That is, the rib 2 does not cause a pumping action inside the runner cone 1, and only a swirl flow is generated by the rotation of the runner 15, and no water flow upward from the lower end of the runner cone 1 is generated.

  On the other hand, according to the runner 15 according to the first embodiment, the rotating rib 21 draws the water flow into the runner cone 1 and passes through the runner blade 4 even when the Francis turbine is at low output. The water flow is not biased toward the outer peripheral side of the runner 15. Therefore, it flows also to the center side of the runner 15, and generation | occurrence | production of the dead water area | region 20 can be suppressed. As a result, the moving width of the whirl 19 that swings around the dead water region 20 is reduced, the hydraulic pulsation is reduced, and there is no fear that the whirl 19 collides with the inner wall of the suction pipe 18 to generate a large vibration.

  Further, by suppressing the generation of the dead water region 20, the uneven flow inside the runner blade 4 is reduced, and an increase in loss inside the runner 15 can be avoided. Thus, according to the first embodiment, even when the Francis turbine is at a low output, water can flow under the center of the runner 15 and the generation of the dead water region 20 can be suppressed. It is possible to realize a water wheel.

  Furthermore, in the first embodiment, a special member is unnecessary because only the structure of the rib 21 that is a strength member is improved. That is, the configuration of attaching the auxiliary blade to the runner cone 1 so as to be freely inserted and removed as in the above-mentioned Patent Document 1 is unnecessary, and the number of members and the number of assembly steps can be reduced. In addition, the rib 21 does not need to have the effect of a blade as an auxiliary to the turbine blade. For this reason, even if the rib 21 is provided, there is no fear that the production cost will rise, and excellent economic efficiency can be ensured.

[Modification of First Embodiment]
As a modified example of the first embodiment, the rib 22 (see FIG. 5) inclined in the direction opposite to the rotation of the runner 15 from the inner peripheral side toward the outer peripheral side, and the features of the shape of the rib 21 and the rib 22 are combined. There are ribs 23 (see FIG. 6). The rib 23 inclines in the opposite direction to the runner 15 rotation from the lower side to the upper side, and inclines in the direction opposite to the rotation direction of the runner 15 from the inner peripheral side to the outer peripheral side.

  These ribs 22 and 23 can provide the same effects as those of the first embodiment. In particular, since the rib 23 is inclined both in the vertical direction and in the horizontal direction (direction from the inner peripheral side toward the outer peripheral side), a good pumping action can be obtained and the effect of reducing the dead water region 20 is high.

(2) Second embodiment
[Constitution]
Next, a second embodiment according to the present invention will be described with reference to FIGS. As shown in FIGS. 7 and 8, in the second embodiment, the runner cone 1 is provided with a communication hole 6 that communicates the inside and outside of the runner cone 1 in proximity to the rib 21. These communication holes 6 are disposed above the lower end of the runner cone 1 and are provided horizontally with respect to the runner cone 1.

[Function and effect]
As shown in FIG. 9, the runner 15 having the rib 21 generates a suction flow into the runner cone 1 by the action of the rib 21 that causes a pumping action, as in the first embodiment. Under this influence, the water flow that has passed through the runner blades 4 is directed from the outside of the runner cone 1 toward the center, but flows toward the inside through the communication holes 6 (solid arrow C in FIG. 9). That is, before going to the lower end of the runner cone 1, it is sucked into the runner cone 1.

  That is, in the second embodiment, the water flow is sucked into the inner peripheral side of the runner cone 1 from the lower end of the runner cone 1 by the rib 21, and at the same time, the water flow is also introduced to the inner peripheral side of the runner cone 1 by the communication hole 6 provided in the runner cone 1. Inhaled. For this reason, it is possible to prevent the biased flow toward the outer periphery of the runner 15 more reliably.

  According to the second embodiment as described above, the communication hole 6 is formed in the runner cone 1, so that the swirl of the whirl 19 can be reduced while the dead water region 20 is further reduced to suppress an increase in loss. As a result, as in the first embodiment, it is possible to realize a hydraulic machine having high efficiency and low vibration on the low output side while ensuring excellent economic efficiency.

[Modification of Second Embodiment]
As a modification of the second embodiment, which is characterized in that the communication hole 6 is provided, there is the following. As shown in FIG. 10, FIG. 11, the thing provided with the communicating hole 61 inclined downward from the outer side of the runner cone 1 to the inner side is also included. According to such an embodiment, the communication hole 61 is opened toward the absolute speed direction during low-power operation. Accordingly, the effect of sucking the water flow into the runner cone 1 becomes larger, and the dead water region 20 can be reliably suppressed.

  In addition, the communication hole 62 shown in FIG. 12 is inclined in the rotational direction of the runner 15 from the outside toward the inside. In this embodiment, the communication hole 62 opens in the direction of the turning speed in the low output operation. Therefore, as in the above modification, the effect of sucking the water flow into the runner cone 1 is increased, and the dead water region 20 can be reliably suppressed.

  In addition, although the modification of 2nd Embodiment shown in FIGS. 10-12 is all provided with the communicating holes 6, 61, 62 in the said 1st Embodiment, it has the ribs 22 and 23. FIG. A combination of the modified example of the first embodiment and the modified example of the second embodiment can be selected as appropriate.

(3) Third embodiment
[Constitution]
Next, a third embodiment according to the present invention will be described with reference to FIGS. As shown in FIGS. 13 and 14, the third embodiment is characterized in that a hollow pipe 7 is provided with respect to the first embodiment having the ribs 21. The pipe 7 is arranged at the center of the rotation axis inside the runner cone 1 and is fixed to the runner cone 1. An annular mounting plate 30 is disposed around the pipe 7, and the mounting plate 30 is fixed to the pipe 7 and the rib 21. The upper portion of the runner cone 1 is partitioned from the runner cone 1 by the mounting plate 30 to form a communication portion 8. The upper part of the pipe 7 communicates with the communication part 8 through a plurality of holes 31 formed in the circumferential direction.

[Function and effect]
The third embodiment as described above has the following unique operational effects. FIG. 14 shows the state of water flow during low-power operation of the Francis turbine. The rib 21 inside the runner cone 1 causes a flow of water upward from the lower end of the runner cone 1 inside the runner cone 1. This water flow flows into the pipe 7 through the communication part 8, and flows out downward from the pipe 7 (solid arrow D in FIG. 14).

  According to the third embodiment as described above, by providing the pipe 7 inside the runner cone 1, the water flow flowing downward from the runner cone 1 and the water flow flowing downward through the pipe 7 are separated. Can do. That is, the water flow outside the runner cone 1 can be sucked more efficiently, and the biased flow can be suppressed to further reduce the dead water region 20. Therefore, as the dead water region 20 becomes smaller, the range in which the whirl 19 swings becomes smaller, and the water pressure pulsation is reduced. This can contribute to the realization of a Francis turbine with high efficiency and low vibration on the low output side.

[Modification of Third Embodiment]
Although not particularly illustrated as a modification of the third embodiment, the pipe 7 may be installed in each modification of the first embodiment, the second embodiment, or a modification thereof. The dimensions and shape of the pipe 7 can be changed as appropriate.

(4) Fourth embodiment
[Constitution]
A fourth embodiment according to the present invention will be described with reference to FIGS. As shown in these drawings, the fourth embodiment is characterized in that a movable lid 9 is provided inside the runner cone 1 as compared with the first embodiment having the rib 21.

  The movable lid 9 is movably installed in the vertical direction, and has a structure in which the vertical direction moves according to the operating state of the Francis turbine. The central axis 9a of the movable lid 9 is hollow, and a hole 9b communicating with the interior of the runner cone 1 is provided above the central axis 9a.

[Function and effect]
FIG. 16 shows the state of water flow during low output operation of the Francis turbine. During low output operation of the Francis turbine, the movable lid 9 is in the lower position, and the lower end of the runner cone 1 communicates with the inner side. For this reason, a water flow is sucked into the runner cone 1 and passes through the hole 9b to generate a suction flow passing through the center shaft 9a of the movable lid 9 (solid arrow E in FIG. 16).

  The bias flow toward the outer periphery of the runner 15 can be suppressed by the influence of the suction flow, and the dead water region 20 can be reduced to prevent an increase in loss. Further, by reducing the dead water region 20, the whirling 19 can be reduced, and the water pressure pulsation can be reduced.

  On the other hand, at the time of high output operation of the Francis turbine, the movable lid 9 moves upward as shown in FIG. For this reason, the movable lid 9 closes the lower end portion of the runner cone 1. Therefore, the large output side is not affected by the suction inside the runner cone 1.

  Further, since the hole 9b of the central shaft 9a is located above the inside of the runner cone 1, the inside of the runner cone 1 is a closed chamber. For this reason, the water flow is not sucked into the runner cone 1 from the outside of the runner cone 1. As already described, at the time of high output of the Francis turbine, the water flow tends to be biased toward the center side of the runner 15 (see FIG. 25).

  Therefore, if there is a suction effect into the runner cone 1 at the time of high output, the biased flow becomes larger and the efficiency may be lowered. Therefore, in the fourth embodiment, by increasing the inside of the runner cone 1 with the movable lid 9, it is possible to prevent an increase in the bias flow toward the center side of the runner 15.

  As a result, there is no uneven flow even when the Francis turbine is operated at a high output, and a reduction in efficiency can be prevented. As described above, according to the fourth embodiment, it is possible to realize a Francis turbine that has high efficiency and low vibration on the low output side, and that does not have a decrease in performance on the high output side.

  Further, the movable lid 9 only needs to be a member capable of sealing the inside of the runner cone 1, and unlike the auxiliary blade of Patent Document 1, it is not necessary to have the effect of the blade as an auxiliary to the turbine blade. For this reason, compared with the auxiliary | assistant blade | wing which must be on the extended line of a runner blade | wing, production cost can be suppressed markedly and it is possible to maintain the outstanding economical efficiency.

[Modification of Fourth Embodiment]
As a modification of the fourth embodiment, the dimensions and shape of the movable lid 9 can be changed as appropriate. Also, the combination of the first to third embodiments and the fourth embodiment can be selected as appropriate.

(5) Fifth embodiment
[Constitution]
Furthermore, a fifth embodiment according to the present invention will be described with reference to FIGS. As shown in these drawings, in the fifth embodiment, a movable rib 10 that is movable in the radial direction is provided inside the runner cone 1. A pressure chamber 11 is provided on the back surface of the rib 10, and the radial position of the movable rib 10 is adjusted by high-pressure water or hydraulic pressure supplied to the pressure chamber 11.

  As shown in FIGS. 20 and 21, the movable rib 10 moves toward the center of the runner 15 and protrudes into the runner cone 1 during low-power operation of the Francis turbine. On the other hand, as shown in FIGS. 22 and 23, during the high-power operation of the Francis turbine, the movable rib 10 is configured to move in the outward direction of the runner 15 so that the amount of protrusion is reduced.

[Function and effect]
As shown in FIGS. 20 and 21, the movable rib 10 inside the runner cone 1 protrudes toward the inner peripheral side of the runner 15 during low-power operation of the Francis turbine. Therefore, as shown in FIG. 20, a flow of water from the lower end to the upper end direction is generated inside the runner cone 1 due to the influence of the movable rib 10 (solid arrow F in FIG. 20).

  Due to the influence of this flow, a biased flow toward the outer periphery of the runner 15 can be suppressed, the dead water region 20 becomes smaller, and a decrease in efficiency is suppressed. Moreover, since the dead water area | region 20 becomes small, the whirling of the whirl 19 also becomes small and a water pressure pulsation can be reduced.

  On the other hand, when the Francis turbine is operated at a high output, as shown in FIGS. 21 and 22, the movable rib 10 moves to the outer peripheral side of the runner 15, and the movable rib 10 does not protrude from the inner surface of the runner 15. For this reason, the effect of the suction flow is reduced inside the runner cone 1.

  On the large output side, the water flow is biased toward the center of the runner 15. For this reason, if there is a suction effect into the runner cone 1, the biased flow becomes larger and the efficiency may decrease. Therefore, in the fifth embodiment, it is possible to minimize the decrease in efficiency by making the movable rib 10 movable in the radial direction and reducing the influence of the movable rib 10. As a result, as in the fourth embodiment, it is possible to realize a Francis turbine having high efficiency and low vibration on the low output side and no deterioration in performance on the high output side.

  In addition, the movable rib 10 should just be provided so that a movement in the radial direction of the runner cone 1 is carried out, and it is not necessary to have the effect of a blade | wing as an assistance of a turbine blade like the auxiliary blade of patent document 1. FIG. For this reason, like the movable lid 9 in the fourth embodiment, the production cost is lower than that of the auxiliary blade that is a turbine blade, and it is possible to exhibit excellent economic efficiency.

DESCRIPTION OF SYMBOLS 1 ... Runner cone 2, 21, 22, 23 ... Rib 3 ... Runner crown 4 ... Runner blade 5 ... Runner band 6, 61, 62 ... Communication hole 7 ... Pipe 8 ... Communication part 9 ... Movable lid 10 ... Movable rib 11 ... Pressure Chamber 12 ... Casing 13 ... Stay vane 14 ... Guide vane 15 ... Runner 16 ... Main shaft 17 ... Generator 18 ... Suction pipe 19 ... Whirl 20 ... Dead water area

Claims (7)

A runner rotatably incorporated in a hydraulic machine, with a runner crown at the top and a runner band at the bottom. In a runner of a hydraulic machine in which a conical runner cone protruding downward is formed on the central axis of the runner crown, and a rib is installed inside the runner cone.
The rib is inclined in the counter-rotating direction of the runner from the lower end side toward the upper end side, from the inner side toward the outer side, or from the lower end side toward the upper end side, while moving from the inner side toward the outer side. Hydraulic machine runner to play.   The runner for a hydraulic machine according to claim 1, wherein a communication hole is provided in the runner cone to allow communication between an outer peripheral side and an inner peripheral side. The communication hole, from the outside to the inside of the runner cone , from above to below, or the runner rotation direction, or from the outside to the inside of the runner cone, from the top to the bottom, in the runner rotation direction, The runner of a hydraulic machine according to claim 2, wherein the runner is inclined.   The hydraulic machine runner according to any one of claims 1 to 3, wherein a pipe is attached to a center of a rotation shaft inside the runner cone, and the pipe communicates with an inner surface of the runner cone at an upper portion of the runner cone.   The hydraulic machine runner according to any one of claims 1 to 4, wherein a movable lid that is movable in the vertical direction is provided inside the runner cone.   The hydraulic machine runner according to any one of claims 1 to 5, wherein at least one of the ribs is provided so as to be movable in a radial direction of the runner cone according to an operating state. A hydraulic machine comprising the runner according to any one of claims 1 to 6 rotatably.

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