JP2019007374A - Runner of movable blade water turbine, discharge ring of movable blade water turbine, and movable blade water turbine - Google Patents

Abstract

To provide a movable blade water turbine capable of preventing leakage flow formed around a runner vane to improve its performance.SOLUTION: A runner 5 of a movable blade water turbine is configured such that on an upstream side outer peripheral surface 12 and downstream side outer peripheral surface 13 of a runner boss 10, concave parts 14, 15 are provided respectively; a runner vane 20 has a central inner peripheral end surface 21 formed in a spherical shape so as to face a central outer peripheral surface 11 of the runner boss 10, and vane extension parts 22, 23 respectively entering the concave parts 14, 15 in a case where an angle of the runner vane 20 becomes a maximum angle; and inner peripheral end surfaces of the vane extension parts 22, 23 are formed on an extension surface of the central inner peripheral end surface 21.SELECTED DRAWING: Figure 2A

Description

  Embodiments of the present invention relate to a runner of a movable blade turbine, a discharge ring of the movable blade turbine, and a movable blade turbine.

  Hydropower machines used in hydropower generation can be broadly divided into impulse turbines and reaction turbines. Examples of the reaction water turbine include a centrifugal water turbine represented by a Francis turbine, a diagonal water turbine represented by a Delia turbine, and an axial flow turbine such as a Kaplan turbine, a propeller turbine, or a valve turbine.

  The runner of the axial flow turbine includes a runner boss and a runner vane provided on the runner boss. In movable vane turbines such as Kaplan turbines and valve turbines, the entire runner vane is rotatable relative to the runner boss. On the other hand, in the propeller turbine, the runner vane is fixed to the runner boss by welding or bolt fastening.

  In the movable impeller turbine, it is possible to control the runner vane angle and the guide vane opening to optimum states according to the required load and operating head. For this reason, the movable impeller turbine can be operated with high efficiency in a wider operation range compared to a turbine in which a runner vane is fixed like a Francis turbine or a propeller turbine.

  However, in order to rotate the runner vanes according to the operating state, a gap is provided between the outer peripheral end face (chip side end face) of the runner vane and the stationary part (discharge ring). In this gap, a water flow is formed as a leakage flow. Since this leakage flow does not give energy to the runner, it simply causes a loss. Further, a gap is also provided between the inner peripheral end surface (boss side end surface) of the runner vane and the runner boss, and a leakage flow is also formed in this gap, resulting in a loss.

JP 2011-102564 A

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a movable impeller turbine capable of suppressing the leakage flow formed around the runner vane and improving the performance.

  The runner of the movable impeller turbine according to the embodiment includes a runner boss and a runner vane that is rotatably provided on the runner boss. The runner boss has a central outer peripheral surface formed in a spherical shape, an upstream outer peripheral surface provided upstream from the central outer peripheral surface, and a downstream outer peripheral surface provided downstream from the central outer peripheral surface. doing. The upstream outer peripheral surface and the downstream outer peripheral surface are formed on the outer peripheral side with respect to the extended surface of the central outer peripheral surface. A recess is provided on the upstream outer peripheral surface or the downstream outer peripheral surface. The runner vane has a central inner peripheral end surface formed in a spherical shape that faces the central outer peripheral surface of the runner boss, and a vane extension that enters the recess when the runner vane angle reaches the maximum angle. The inner peripheral end surface of the vane extension is formed on the extended surface of the central inner peripheral end surface.

  The runner of the movable vane turbine according to the embodiment is a runner of a movable vane turbine provided on the inner peripheral side of a discharge ring having a spherical inner peripheral surface formed in a spherical shape. The runner of the movable impeller turbine includes a runner boss and a runner vane that is rotatably provided on the runner boss. The runner vane has a spherical outer peripheral end surface facing the spherical inner peripheral surface of the discharge ring, and a vane groove provided on the outer peripheral end surface. The vane groove extends in a direction intersecting with the flow direction of the leakage flow formed in the gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring.

  The movable vane turbine according to the embodiment includes the above-described runner of the movable vane turbine and a discharge ring provided on the outer peripheral side of the runner of the movable vane turbine.

  The discharge ring of the movable impeller turbine according to the embodiment is a movable impeller turbine provided on the outer peripheral side of a runner having a runner boss and a runner vane including a peripheral end surface formed in a spherical shape and rotatably provided on the runner boss. It is a discharge ring. The discharge ring of the movable impeller water turbine includes a spherical inner peripheral surface formed in a spherical shape facing the outer peripheral end surface of the runner vane, and a ring groove provided in the spherical inner peripheral surface. The ring groove extends in a direction crossing the flow direction of the leakage flow formed in the gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring.

  The movable vane turbine according to the embodiment includes the discharge ring of the movable vane turbine described above and a runner provided on the inner peripheral side of the discharge ring.

  According to the present invention, the leakage flow formed around the runner vanes can be suppressed, and the performance can be improved.

FIG. 1 is a cross-sectional view showing a schematic configuration of a Kaplan turbine according to the first embodiment. FIG. 2A is a front view of the runner of FIG. 1 when the runner vane has a maximum angle, and is a front view mainly showing the runner vane disposed in front. FIG. 2B is a front view of the runner of FIG. 2A, showing a runner vane disposed mainly laterally. FIG. 2C is a schematic plan view showing the runner of FIG. 2A. 3A is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. 2A. FIG. 4A is a front view showing the runner of FIG. 1 when the angle of the runner vane is the minimum angle, and is a front view showing the runner vane arranged mainly in the front. FIG. 4B is a front view of the runner of FIG. 4A, showing a runner vane disposed mainly laterally. FIG. 4C is a schematic plan view showing the runner of FIG. 4A. FIG. 5A is a front view showing a runner of a general Kaplan turbine as a comparative example when the runner vane has a maximum angle. FIG. 5B is a schematic plan view showing the runner of FIG. 5A. FIG. 6A is a front view showing a runner of a general Kaplan turbine as a comparative example when the runner vane has a minimum angle. FIG. 6B is a schematic plan view showing the runner of FIG. 6A. FIG. 7 is a view showing a flow around the runner vane shown in FIG. 6 as a comparative example. FIG. 8 is a diagram showing a flow around the runner vane shown in FIG. 4 as the first embodiment. FIG. 9A is a front view showing the runner when the runner vane angle is the minimum angle in the Kaplan turbine in the second embodiment. FIG. 9B is a plan view of FIG. It is CC sectional view taken on the line, FIG.9 (c) is DD sectional view taken on the line of Fig.9 (a). FIG. 10A is a front view showing a runner when the angle of the runner vane is the minimum angle in the Kaplan turbine in the third embodiment, and FIG. 10B is a plan view of FIG. It is EE sectional view taken on the line. FIG. 11 is a front view showing the runner when the runner vane angle reaches the maximum angle in the Kaplan turbine according to the fourth embodiment. FIG. 12 is a plan sectional view showing a leakage flow formed in a gap between a runner vane and a discharge ring shown as a comparative example shown in FIGS. 5A to 6B. FIG. 13 is a plan sectional view showing a leakage flow formed in a gap between the runner vane and the discharge ring shown in FIG. FIG. 14 is an enlarged front view showing a modification of the vane groove shown in FIG. 11. FIG. 15 is an enlarged front view showing another modification of the vane groove shown in FIG. FIG. 16 is a front view showing the runner when the runner vane angle reaches the maximum angle in the Kaplan turbine according to the fifth embodiment. FIG. 17 is a plan sectional view showing a leakage flow formed in a gap between the runner vane and the discharge ring shown in FIG. FIG. 18 is a front view showing a modification of the runner shown in FIG.

  Hereinafter, a runner of a movable impeller turbine, a discharge ring of a movable impeller turbine, and a movable impeller turbine in an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
First, the runner of the movable blade turbine, the discharge ring of the movable blade turbine, and the movable blade turbine according to the first embodiment will be described with reference to FIGS. Here, first, a Kaplan turbine, which is an example of a movable vane turbine, will be described with reference to FIG.

  As shown in FIG. 1, a Kaplan water turbine 1 flows from a casing 2 into which water flows from an unillustrated upper pond and a casing 2 rotatably provided to the casing 2 through a stay vane 3 and a guide vane 4. And a discharge ring 60 provided on the outer peripheral side of the runner 5.

  The stay vane 3 is for forming a flow path from the casing 2 to the runner 5, and is disposed on the inner peripheral side from the casing 2. The guide vane 4 is for adjusting the flow rate of water flowing into the runner 5, and is arranged on the inner peripheral side from the stay vane 3. By changing the opening degree of the guide vane 4, the amount of water flowing from the casing 2 into the runner 5 is adjusted, and the power generation amount is changed.

  The runner 5 is disposed on the inner peripheral side and on the downstream side of the guide vane 4. The main flow direction of the water flowing in from the casing 2 is substantially in the radial direction in the stay vanes 3 and the guide vanes 4, but in the runner 5 is in the direction of the runner rotation axis X (vertical direction).

  A generator 7 is connected to the runner 5 via a rotating main shaft 6. When the runner 5 is rotationally driven by the inflowing water, the generator 7 generates power.

  A suction pipe 8 is provided on the downstream side of the runner 5. The suction pipe 8 is connected to a lower pond (not shown), and water in which the runner 5 is rotationally driven is discharged to the lower pond.

  The discharge ring 60 described above is provided on the outer peripheral side of the runner vane 20. The discharge ring 60 defines a flow path of water that passes through the runner 5.

  Next, the runner 5 according to the present embodiment will be described in more detail.

  As shown in FIG. 1, the runner 5 includes a runner boss 10 that can rotate about the runner rotation axis X, and a plurality of runner vanes 20 that are rotatably provided on the runner boss 10. Of these, the runner vane 20 is rotatable about the vane rotation axis Y. The runner vanes 20 are arranged at predetermined intervals in the circumferential direction, and the angle of the runner vanes 20 is adjusted according to a required load (flow rate of water) and an operating difference by rotating each runner vane 20. Therefore, highly efficient operation is possible over a wide operation range. The runner boss 10 is connected to the rotary main shaft 6 described above, and the rotation of the runner boss 10 is transmitted to the generator 7 via the rotary main shaft 6.

  As shown in FIGS. 2A and 2B, the runner boss 10 includes a central outer peripheral surface 11 formed in a spherical shape, an upstream outer peripheral surface 12 provided upstream of the central outer peripheral surface 11, and a central outer peripheral surface 11. And the downstream outer peripheral surface 13 provided on the downstream side. The upstream outer peripheral surface 12 and the downstream outer peripheral surface 13 are formed in an aspherical shape (for example, a conical shape or a cylindrical shape) so as to be disposed on the outer peripheral side with respect to the extended surface 11 a of the central outer peripheral surface 11.

  The runner vane 20 has a central inner peripheral end surface 21 formed in a spherical shape facing the central outer peripheral surface 11 of the runner boss 10, and an upstream vane extension 22 and a downstream vane extension 23. Among these, a gap is formed between the central inner peripheral end surface 21 of the runner vane 20 and the central outer peripheral surface 11 of the runner boss 10, so that the runner vane 20 can be smoothly rotated with respect to the runner boss 10.

  The upstream vane extension 22 is formed on the upstream side of the central inner peripheral end surface 21, and the downstream vane extension 23 is formed on the downstream side of the central inner peripheral end surface 21. Each of the vane extension portions 22 and 23 includes inner peripheral end surfaces 22 a and 23 a formed in a spherical shape on the extension surface of the central inner peripheral end surface 21. That is, the upstream vane extension portion 22 includes an upstream inner peripheral end surface 22 a formed in a spherical shape on the extension surface of the central inner peripheral end surface 21, and the downstream vane extension portion 23 includes the central inner peripheral end surface 21. A downstream inner peripheral end surface 23a formed in a spherical shape on the extended surface. The upstream inner peripheral end surface 22a and the downstream inner peripheral end surface 23a have the same spherical surface as the central inner peripheral end surface 21, and the upstream inner peripheral end surface 22a, the central inner peripheral end surface 21 and the downstream inner peripheral end surface 23a are continuous. It is formed in a spherical shape.

  As shown in FIGS. 2A to 2C and FIG. 3A, the same number of upstream recesses 14 as the runner vanes 9 are provided on the upstream outer peripheral surface 12 of the runner boss 10. When the angle of the corresponding runner vane 20 reaches the maximum angle, the upstream vane extension 22 of the runner vane 20 enters each upstream recess 14. The upstream recess 14 includes an upstream bottom surface 14 a formed in a spherical shape on the extended surface 11 a of the central outer peripheral surface 11 of the runner boss 10. The upstream side bottom surface 14a has the same spherical surface as the central outer peripheral surface 11, and the upstream side bottom surface 14a and the central outer peripheral surface 11 are formed in a continuous spherical shape. The upstream recess 14 extends to the central outer peripheral surface 11.

  As shown in FIGS. 2A to 2C, in the present embodiment, the upstream recess 14 is formed so that the upstream vane extension 22 of the runner vane 20 enters from the maximum angle to a predetermined angle. ing. And the upstream recessed part 14 is formed so that it may become shallow as the angle of the runner vane 20 becomes small in the direction along the rotation locus of the upstream vane extension part 22 of the runner vane 20. As shown in FIG. 4A to FIG. 4C, in the present embodiment, the upstream recess 14 enters the upstream vane extension 22 of the runner vane 20 even when the angle of the runner vane 20 becomes the minimum angle. ing. That is, the upstream vane extension 22 enters the upstream recess 14 in the entire angle range of the runner vane 20.

  As shown in FIGS. 2A to 2C and FIG. 3B, the same number of downstream recesses 15 as the runner vanes 20 are provided on the downstream outer peripheral surface 13 of the runner boss 10. When the angle of the corresponding runner vane 20 reaches the maximum angle, the downstream vane extension 23 of the runner vane 20 enters each downstream recess 15. The downstream recess 15 includes a downstream bottom surface 15 a formed in a spherical shape on the extended surface 11 a of the central outer peripheral surface 11 of the runner boss 10. The downstream side bottom surface 15a has the same spherical surface as the central outer peripheral surface 11, and the downstream side bottom surface 15a and the central outer peripheral surface 11 are formed in a continuous spherical shape. The downstream recess 15 extends to the central outer peripheral surface 11.

  As shown in FIGS. 2A to 2C, in the present embodiment, the downstream recess 15 is formed such that the downstream vane extension 23 of the runner vane 20 enters from the maximum angle to a predetermined angle. ing. And the downstream recessed part 15 is formed so that it may become shallow as the angle of the runner vane 20 becomes small in the direction along the rotation locus of the downstream vane extension part 23 of the runner vane 20. As shown in FIG. 4A to FIG. 4C, in the present embodiment, the downstream recess 15 is adapted to receive the downstream vane extension 23 of the runner vane 20 even when the angle of the runner vane 20 becomes the minimum angle. ing. That is, the downstream vane extension 23 enters the downstream recess 15 in the entire angle range of the runner vane 20.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, a general Kaplan turbine runner as a comparative example will be described with reference to FIGS. 5A to 6B.

  Generally, a gap is provided between the runner vane 20 and the runner boss 10 in order to rotate the runner vane 20 according to the operating state. Since this gap forms a leakage flow that becomes a loss, it is preferable that the gap is small.

  In order to reduce such a gap, it is preferable to form both the inner peripheral end surface of the runner vane 20 and the outer peripheral surface of the runner boss 10 into a spherical shape. However, since a link mechanism (not shown) for rotating the runner vane 20 is provided inside the runner boss 10, the innermost runner vane 20 of the runner boss 10 has the maximum angle. It is difficult to form a portion facing the peripheral end surface in a spherical shape. Thus, the upstream outer peripheral surface 12 and the downstream outer peripheral surface 13 of the runner boss 10 are arranged on the outer peripheral side with respect to the extended surface 11a of the central outer peripheral surface 11, and are formed in a conical shape or a cylindrical shape. Therefore, as shown in FIGS. 5A and 5B, the upstream inner peripheral end and the downstream inner peripheral end of the runner vane 20 are arranged so as not to interfere with the runner boss 10 even when the runner vane 20 has the maximum angle. However, it is shaved and the notch CU is formed. However, by forming such a notch CU, as shown in FIGS. 6A and 6B, when the angle of the runner vane 20 is small, the notch CU is formed between the notch CU and the runner boss 10. The gap becomes larger.

  As shown in FIG. 7, a leakage flow as shown by a broken line is formed in a gap formed between the cutout portion CU on the upstream side formed in the runner vane 20 and the runner boss 10. Since this leakage flow does not pass through the pressure surface of the runner vane 20, the torque of the runner 5 is reduced. Further, when this leakage flow passes through the gap, the main flow flowing between the adjacent runner vanes 20 may be disturbed, resulting in an increase in loss. In some cases, cavitation may occur.

  In the gap formed between the cutout CU on the downstream side of the runner vane 20 and the runner boss 10, the flow of water that has flowed along the central outer peripheral surface 11 of the runner boss 10 on the pressure surface of the runner vane 20 easily flows. Become. This generates a biased flow on the pressure surface, leading to an increase in loss.

  On the other hand, in the present embodiment, the upstream vane extension 22 and the downstream vane extension 23 shown in FIGS. 2A to 2C and FIGS. 4A to 4C are provided at the positions of the notches CU shown in FIGS. 5A to 6B. Are provided. The upstream inner peripheral end surface 22a of the upstream vane extension 22 is formed in a spherical shape on the extension surface of the central inner peripheral end surface 21, and the downstream inner peripheral end surface 23a of the downstream vane extension 23 is A spherical surface is formed on the extended surface of the central inner peripheral end surface 21. Thus, even when the angle of the runner vane 20 becomes the minimum angle, the gap between the upstream inner peripheral end surface 22a of the runner vane 20 and the upstream outer peripheral surface 12 of the runner boss 10 is small. Similarly, the clearance gap between the downstream inner peripheral end surface 23a of the runner vane 20 and the downstream outer peripheral surface 13 of the runner boss 10 is reduced. For this reason, as shown in FIG. 8, it is suppressed that the leak flow which does not pass through a pressure surface is formed, and the torque of the runner 5 can be increased. Further, in this case, since the leakage flow passing through the gap is suppressed, the main flow flowing between the adjacent runner vanes 20 is suppressed from being disturbed.

  Thus, according to the present embodiment, even when the angle of the runner vane 20 becomes the minimum angle, the leakage flow formed in the gap between the runner vane 20 and the runner boss 10 can be suppressed. For this reason, generation | occurrence | production of a loss can be suppressed and generation | occurrence | production of cavitation can be suppressed, As a result, performance can be improved. On the other hand, when the angle of the runner vane 20 reaches the maximum angle, the upstream vane extension 22 of the runner vane 20 enters the corresponding upstream recess 14 of the runner boss 10, and the downstream vane extension 23 of the runner vane 20 The runner boss 10 enters the corresponding downstream recess 15. Thus, the runner vane 20 can be prevented from interfering with the runner boss 10, and the runner vane 20 can be smoothly rotated.

  Further, according to the present embodiment, the upstream recess 14 includes the upstream bottom surface 14 a formed in a spherical shape on the extended surface 11 a of the central outer peripheral surface 11. Thereby, the clearance gap between the upstream inner peripheral end surface 22a of the upstream vane extension part 22 and the upstream bottom face 14a can be made small. For this reason, it can suppress that a leak flow is formed in this clearance gap, and can suppress generation | occurrence | production of a loss. Similarly, the downstream recess 15 includes a downstream bottom surface 15 a formed in a spherical shape on the extended surface 11 a of the central outer peripheral surface 11. Thereby, the clearance gap between the downstream inner peripheral end surface 23a of the downstream vane extension part 23 and the downstream outer peripheral surface 13 can be made small. For this reason, it can suppress that a leak flow is formed in this clearance gap, and can suppress generation | occurrence | production of a loss.

  In the present embodiment described above, the upstream concave portion 14 is provided on the upstream outer peripheral surface 12 of the runner boss 10, and the downstream concave portion 15 is provided on the downstream outer peripheral surface 13. The example which has the upstream vane extension part 22 and the downstream vane extension part 23 was demonstrated. However, the present invention is not limited to this, and the runner vane 20 may not have one of the upstream vane extension 22 and the downstream vane extension 23. For example, the runner vane 20 does not have the upstream vane extension 22 and the upstream recess 14 may not be provided in the upstream outer peripheral surface 12. Alternatively, the runner vane 20 does not have the downstream vane extension 23, and the downstream recess 15 may not be provided on the downstream outer peripheral surface 13. Even in this case, the leakage flow formed in the gap between the runner vane 20 and the runner boss 10 can be suppressed.

(Second Embodiment)
Next, the runner of the movable vane turbine, the discharge ring of the movable vane turbine, and the movable vane turbine according to the second embodiment of the present invention will be described with reference to FIG.

  The second embodiment shown in FIG. 9 is mainly different in that a movable wall is provided in the upstream recess and the movable recess so as to be able to advance and retreat. This is substantially the same as the first embodiment shown in FIG. In FIG. 9, the same parts as those in the first embodiment shown in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, as shown in FIGS. 9A and 9B, the upstream movable wall 30 is provided in each upstream recess 14 so as to be able to advance and retract. The upstream movable wall 30 is provided so as to be movable in the circumferential direction around the runner rotation axis X (in the left-right direction in FIG. 9A). In general, the upstream movable wall 30 can advance in the direction in which the angle of the runner vane 20 decreases in the upstream recess 14. The upstream movable wall 30 is positioned inside the runner boss 10 when retreating. An opening (not shown) through which the upstream movable wall 30 passes is provided on the wall surface of the upstream recess 14. In this opening, a seal member (not shown) is provided around the upstream movable wall 30 to prevent water from entering the runner boss 10.

  Inside the runner boss 10, an upstream movable wall drive unit 32 that moves the upstream movable wall 30 into and out of the upstream recess 14 is provided. The plurality of upstream movable walls 30 may be advanced and retracted by one upstream movable wall drive unit 32. The upstream movable wall drive unit 32 is preferably interlocked with a vane drive unit (not shown) that rotates the runner vane 20 by a control device (not shown). By interlocking in this way, the upstream movable wall 30 can be automatically advanced and retracted with the rotation of the runner vane 20. The upstream movable wall drive unit 32 can be configured by a motor, for example.

  Similarly, as shown in FIGS. 9A and 9C, a downstream movable wall 31 is provided in each downstream recess 15 so as to be able to advance and retract. The downstream movable wall 31 is provided so as to be movable in the circumferential direction around the runner rotation axis X. The downstream movable wall 31 can be advanced in the direction in which the angle of the runner vane 20 decreases in the downstream recess 15. The downstream movable wall 31 is positioned inside the runner boss 10 when retreating. The wall surface of the downstream recess 15 is provided with an opening (not shown) through which the downstream movable wall 31 passes. In this opening, a seal member (not shown) is provided around the downstream side movable wall 31 to prevent water from entering the runner boss 10.

  Inside the runner boss 10, a downstream movable wall drive unit 33 that moves the downstream movable wall 31 into and out of the downstream recess 15 is provided. The plurality of downstream movable walls 31 may be advanced and retracted by one downstream movable wall drive unit 33. The downstream movable wall drive unit 33 is preferably interlocked with a vane drive unit (not shown) that rotates the runner vane 20 by a control device (not shown). By interlocking in this way, the downstream movable wall 31 can be automatically advanced and retracted with the rotation of the runner vane 20. The downstream side movable wall drive unit 33 can be configured by a motor, for example.

  When the angle of the runner vane 20 reaches the maximum angle, the upstream movable wall 30 retreats from the upstream recess 14 and the upstream recess 14 is entirely opened. Similarly, the downstream side movable wall 31 is retracted from the downstream side recessed part 15, and the downstream side recessed part 15 is entirely opened.

  On the other hand, when the angle of the runner vane 20 becomes the minimum angle, as shown in FIG. 9A, the upstream movable wall 30 advances into the upstream recess 14 and the upstream vane extension portion of the runner vane 20 is reached. The upstream recess 14 is closed to the extent that it does not interfere with the contact 22. The downstream movable wall 31 advances into the downstream recess 15 and closes the downstream recess 15 to the extent that it does not interfere with the downstream vane extension 23 of the runner vane 20.

  Thus, according to the present embodiment, the upstream movable wall 30 can partially close the upstream recess 14. Thereby, it is possible to suppress the main flow from being disturbed by the upstream recess 14. Similarly, the downstream movable wall 31 can partially close the downstream recess 15, and the mainstream can be prevented from being disturbed by the downstream recess 15. For this reason, loss can be further reduced and performance can be further improved.

(Third embodiment)
Next, the runner of the movable blade turbine, the discharge ring of the movable blade turbine, and the movable blade turbine according to the third embodiment of the present invention will be described with reference to FIG.

  The third embodiment shown in FIG. 10 is mainly different in that the elastic body is filled in the upstream concave portion and the downstream concave portion, and other configurations are the same as those shown in FIGS. This is substantially the same as the first embodiment. In FIG. 10, the same parts as those in the first embodiment shown in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, as shown in FIGS. 10 (a) and 10 (b), the upstream concave portion 14 and the downstream concave portion 15 are filled with elastic bodies 40 made of, for example, rubber or the like. ing. When the upstream vane extension 22 enters the upstream recess 14, the elastic body 40 filled in the upstream recess 14 is elastically deformed into a concave shape and receives the upstream vane extension 22, and the upstream vane extension When the portion 22 does not enter the upstream concave portion 14, it is preferable that the low friction member 41 described later has elasticity that can be restored to a state in which the extended surface of the upstream outer peripheral surface 12 is formed. It is. Similarly, when the downstream vane extension 23 enters the downstream recess 15, the elastic body 40 filled in the downstream recess 15 is elastically deformed into a concave shape and receives the downstream vane extension 23. When the side vane extension 23 does not enter the downstream recess 15, the low-friction member 41 described later has elasticity that can be restored to a state in which the extension surface of the downstream outer peripheral surface 13 is formed. Is preferred.

  As shown in FIG. 10B, a low friction member 41 is provided on the surface (outer peripheral side surface) of the elastic body 40. The low friction member 41 has a relatively small coefficient of friction. That is, the friction coefficient between the runner vane 20 and the low friction member 41 is smaller than the friction coefficient between the runner vane 20 and the elastic body 40. The low friction member 41 is preferably formed over the entire surface of the elastic body 40.

  As described above, according to the present embodiment, since the upstream concave portion 14 and the downstream concave portion 15 are filled with the elastic body 40, respectively, the main stream is prevented from being disturbed by the upstream concave portion 14 and the downstream concave portion 15. Can do. On the other hand, the upstream vane extension 22 and the downstream vane extension 23 can enter the corresponding recesses 14 and 15 by elastically deforming the elastic body 40. And the low friction member 41 is provided in the surface of the elastic body 40, and the runner vane 20 can be smoothly rotated.

(Fourth embodiment)
Next, the runner of the movable blade turbine, the discharge ring of the movable blade turbine, and the movable blade turbine according to the fourth embodiment of the present invention will be described with reference to FIGS.

  The fourth embodiment shown in FIGS. 11 to 15 is mainly different in that a vane groove is provided on the outer peripheral end surface of the runner vane formed in a spherical shape facing the spherical inner peripheral surface of the discharge ring, Other configurations are substantially the same as those of the first embodiment shown in FIGS. 11 to 15, the same parts as those of the first embodiment shown in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, as shown in FIG. 11, the discharge ring 60 has a spherical inner peripheral surface 61 formed in a spherical shape. The runner 5 is disposed on the inner peripheral side of the discharge ring 60. The runner vane 20 has an outer peripheral end surface 50 formed in a spherical shape facing the spherical inner peripheral surface 61 of the discharge ring 60, and a vane groove 51 provided in the outer peripheral end surface 50. In the embodiment shown in FIG. 11, the runner vane 20 is not provided with the upstream vane extension 22 and the downstream vane extension 23, and the runner boss 10 is provided with neither the upstream recess 14 nor the downstream recess 15. .

  The vane groove 51 extends in a direction intersecting the flow direction of the leakage flow formed in the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. Here, the flow direction of the leakage flow on the outer peripheral end face 50 of the runner vane 20 changes according to the angle of the runner vane 20. For this reason, when the runner vane 20 is positioned at a desired angle (the angle at which the runner vane 20 should most reduce the loss), the vane groove 51 may intersect at the largest intersecting angle with respect to the flow direction of the leakage flow. Is preferred.

  In the present embodiment, the vane groove 51 is formed so as to extend along the camber line C on the outer peripheral end surface 50 of the runner vane 20. In the form shown in FIG. 11, one vane groove 51 is formed on the outer peripheral end face 50, and this vane groove 51 is formed so as to extend along the camber line C as a whole.

The vane groove 51 is disposed at a height position between the upstream end of the spherical inner peripheral surface 61 of the discharge ring 60 and the downstream end of the spherical inner peripheral surface 61 in the direction along the runner rotation axis X of the runner 5. Yes. More specifically, as shown in FIG.
LR1 <LD1, LR2 <LD2
Is satisfied. Here, LR1 is a dimension from the vane rotation axis Y to the upstream end of the vane groove 51, and LR2 is a dimension from the vane rotation axis Y to the downstream end of the vane groove 51. LD1 is a dimension from the vane rotation axis Y to the upstream end of the spherical inner peripheral surface 61 of the discharge ring 60, and LD2 is a dimension from the vane rotation axis Y to the downstream end of the spherical inner peripheral surface 61 of the discharge ring 60. Dimensions.

  Such an arrangement of the vane grooves 51 is preferably satisfied in at least a part of the entire angle range of the runner vanes 20. More preferably, it is preferable that the runner vane 20 is satisfied even when the angle reaches the maximum angle. In this case, the vane groove 51 can be entirely opposed to the spherical inner peripheral surface 61 of the discharge ring 60 regardless of the angle of the runner vane 20.

  Here, in general, a gap is provided between the runner vane 20 and the discharge ring 60 in order to rotate the runner vane 20 according to the operating state. Since this gap forms a leakage flow that becomes a loss, it is preferable that the gap is small.

  In order to reduce such a gap, it is preferable to form both the outer peripheral end face 50 of the runner vane 20 and the inner peripheral face of the discharge ring 60 in a spherical shape. However, a portion of the inner peripheral surface of the discharge ring 60 that faces the outer peripheral end surface 50 of the runner vane 20 having the maximum angle for assembling the runner and connecting the upstream flow channel and the downstream flow channel. Is difficult to form in a spherical shape. For this reason, when the angle of the runner vane 20 is large, a gap formed between the outer peripheral end surface 50 of the runner vane 20 and the inner peripheral surface of the discharge ring 60 at the upstream end is increased. Further, a gap formed between the outer peripheral end surface 50 of the runner vane 20 and the inner peripheral surface of the discharge ring 60 at the downstream end is also increased.

  As shown in FIG. 12, a leakage flow as shown by a broken line is formed in a gap formed between the outer peripheral end face 50 and the inner peripheral face of the discharge ring 60 at the upstream end of the runner vane 20. Since this leakage flow does not pass through the pressure surface, the torque of the runner 5 is reduced. Further, when this leakage flow passes through the gap, the main flow flowing between the adjacent runner vanes 20 may be disturbed, resulting in an increase in loss. In some cases, cavitation may occur.

  The gap formed between the outer peripheral end face 50 and the inner peripheral face of the discharge ring 60 at the downstream end of the runner vane 20 was flowing along the inner peripheral face of the discharge ring 60 on the pressure face of the runner vane 20. Water flow becomes easy to flow in. This generates a biased flow on the pressure surface, leading to an increase in loss.

  In contrast, in the present embodiment, as shown in FIG. 11, a vane groove 51 is provided on the outer peripheral end surface 50 of the runner vane 20. The extending direction of the vane groove 51 intersects the direction of the leakage flow formed in the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. That is, as indicated by arrows in FIG. 11, the leakage flow formed in the gap flows from the pressure surface of the runner vane 20 toward the negative pressure surface, but toward the downstream side of the direction perpendicular to the camber line C. Become. As a result, the leakage flow flows across the vane groove 51. For this reason, as shown in FIG. 13, part of the leakage flow enters the vane groove 51, and a vortex is formed in the vane groove 51. This vortex acts as a loss for the leakage flow that flows through this gap, and the leakage flow that passes through the gap is suppressed.

  As described above, according to the present embodiment, since the vane groove 51 is provided in the outer peripheral end surface 50 of the runner vane 20, the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. It is possible to suppress the formation of a leak flow at. Thereby, generation | occurrence | production of the loss with respect to a mainstream can be suppressed. Further, it is possible to suppress the occurrence of a biased flow (secondary flow) from the pressure surface of the runner vane 20 toward the gap, and it is possible to reduce the secondary flow loss. For this reason, generation | occurrence | production of a loss can be suppressed and generation | occurrence | production of cavitation can be suppressed, As a result, performance can be improved.

  Further, according to the present embodiment, the vane groove 51 includes the upstream end of the spherical inner peripheral surface 61 of the discharge ring 60 and the downstream end of the spherical inner peripheral surface 61 in the direction along the runner rotation axis X of the runner 5. It is arranged at the height position between. Thus, the vane groove 51 can be opposed to the spherical inner peripheral surface 61 of the discharge ring 60. That is, the vane groove 51 faces a large gap between the runner vane 20 and the discharge ring 60 when facing the surface upstream or downstream of the spherical inner peripheral surface 61 of the discharge ring 60. End up. In this case, a flow passing through the vane groove 51 is likely to occur, and leakage loss may increase. On the other hand, according to the present embodiment, since the vane groove 51 faces the spherical inner peripheral surface 61 of the discharge ring 60, the facing gap is reduced. For this reason, generation | occurrence | production of a flow through can be suppressed and a leakage loss can be suppressed.

  In the above-described embodiment, the example in which the vane groove 51 is formed along the camber line C on the outer peripheral end surface 50 of the runner vane 20 has been described. However, the present invention is not limited to this, and it is optional as long as the vane groove 51 extends in a direction crossing the flow direction of the leakage flow.

  For example, as shown in FIG. 14, the vane groove 51 may be formed so as to extend in a direction (horizontal direction) orthogonal to the runner rotation axis X when the runner vane 20 is positioned at a desired angle. Good. FIG. 14 shows an example in which a plurality of vane grooves 51 are provided on the outer peripheral end face 50 of the runner vane 20, and each vane groove 51 extends in a direction orthogonal to the runner rotation axis X. . The plurality of vane grooves 51 are spaced apart from each other in the direction along the runner rotation axis X.

  Further, for example, a plurality of vane grooves 51 a, 51 b, 51 c extending in different directions may be provided on the outer peripheral end surface 50 of the runner vane 20. In the form shown in FIG. 15, a first vane groove 51 a, a plurality of second vane grooves 51 b, and a plurality of third vane grooves 51 c are provided on the outer peripheral end surface 50 of the runner vane 20. Among these, the 1st vane groove | channel 51a is formed so that it may extend along the camber line C similarly to the vane groove | channel 51 shown in FIG. The second vane groove 51b is formed to extend in a direction orthogonal to the runner rotation axis X, similarly to the vane groove 51 shown in FIG. The third vane groove 51c is formed to extend in a direction along the runner rotation axis X. The second vane groove 51b and the third vane groove 51c communicate with the first vane groove 51a. In this way, by providing a plurality of vane grooves 51a, 51b, 51c extending in different directions, the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60 are not affected by the angle of the runner vane 20. The leakage flow passing through the gap between them can cross at least a part of the vane grooves 51a, 51b, 51c, and the formation of the leakage flow can be suppressed.

(Fifth embodiment)
Next, the runner of the movable blade turbine, the discharge ring of the movable blade turbine, and the movable blade turbine according to the fifth embodiment of the present invention will be described with reference to FIGS.

  The fourth embodiment shown in FIGS. 16 to 18 is mainly different in that a vane groove is provided on the spherical inner peripheral surface of the discharge ring formed in a spherical shape facing the outer peripheral end surface of the runner vane. Other configurations are substantially the same as those of the fourth embodiment shown in FIGS. 16 to 18, the same parts as those of the fourth embodiment shown in FIGS. 11 to 15 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, as shown in FIG. 16, a ring groove 62 is provided on the spherical inner peripheral surface 61 of the discharge ring 60. In the present embodiment, the runner vane 20 is not provided with the vane groove 51.

  The ring groove 62 extends in a direction crossing the flow direction of the leakage flow formed in the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. Here, when the runner vane 20 is positioned at an angle at which the loss should be reduced most, it is preferable that the ring groove 62 intersects with the largest crossing angle with respect to the flow direction of the leakage flow.

  In the present embodiment, a plurality of ring grooves 62 are provided on the spherical inner peripheral surface 61, and each ring groove 62 extends in a direction (horizontal direction) orthogonal to the runner rotation axis X. Each ring groove 62 is formed in an annular shape, that is, over the entire circumference around the runner rotation axis X. The plurality of ring grooves 62 are spaced apart from each other in the direction along the runner rotation axis X. In FIG. 16, the ring groove 62 formed on the front side of the drawing is indicated by a two-dot chain line.

  As described above, according to the present embodiment, the ring groove 62 is provided on the spherical inner peripheral surface 61 of the discharge ring 60, and the ring groove 62 includes the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. It extends in a direction crossing the flow direction of the leakage flow formed in the gap between them. In this case, as shown in FIG. 17, part of the leakage flow enters the ring groove 62, and a vortex is formed in the ring groove 62. The vortex acts as a loss on the leakage flow, and the leakage flow can be suppressed. This can suppress the formation of a leak flow in the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60. For this reason, generation | occurrence | production of the loss with respect to a mainstream can be suppressed. Further, it is possible to suppress the occurrence of a biased flow (secondary flow) from the pressure surface of the runner vane 20 toward the gap, and it is possible to reduce the secondary flow loss. Therefore, generation | occurrence | production of a loss can be suppressed and generation | occurrence | production of cavitation can be suppressed, As a result, performance can be improved.

  Further, according to the present embodiment, the ring groove 62 extends in a direction orthogonal to the runner rotation axis X. As a result, while the runner 5 is rotating, a leakage flow is formed in the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60 without being related to the position of the runner vane 20. This can be suppressed.

  In the above-described embodiment, the example in which the ring groove 62 extends in the direction orthogonal to the runner rotation axis X has been described. However, the present invention is not limited to this, and the ring groove 62 may extend in a direction perpendicular to the camber line C on the outer peripheral end face 50 of the runner vane 20 as shown in FIG. Even in this case, the leakage flow that passes through the gap between the outer peripheral end surface 50 of the runner vane 20 and the spherical inner peripheral surface 61 of the discharge ring 60 can intersect the ring groove 62, thereby forming a leakage flow. Can be suppressed. In FIG. 18, the ring groove 62 formed on the front side of the drawing is indicated by a two-dot chain line.

  According to the embodiment described above, the leakage flow formed around the runner vanes can be suppressed and the performance can be improved.

    Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof. Moreover, as a matter of course, these embodiments can be partially combined as appropriate within the scope of the present invention.

  For example, the first embodiment and the second embodiment may be combined, or the first embodiment and the third embodiment may be combined. In this case, it is possible to suppress a leakage flow from being formed in the gap between the runner vane 20 and the runner boss 10, and to form a leakage flow in the gap between the runner vane 20 and the discharge ring 60. Can be suppressed, and the performance can be further improved.

1: Kaplan water wheel, 5: Runner, 10: Runner boss, 11: Center outer peripheral surface, 11a: Extension surface, 12: Upstream outer peripheral surface, 13: Downstream outer peripheral surface, 14: Upstream concave portion, 14a: Upstream bottom surface, 15: Downstream concave portion, 15a: Downstream bottom surface, 20: Runner vane, 21: Central inner peripheral end surface, 22: Upstream vane extension, 22a: Upstream inner peripheral end surface, 23: Downstream vane extension, 23a: Downstream Side inner peripheral end surface, 30: upstream movable wall, 31: downstream movable wall, 32: upstream movable wall drive unit, 33: downstream movable wall drive unit, 40: elastic body, 50: outer peripheral end surface, 51: vane Groove, 60: discharge ring, 61: spherical inner peripheral surface, 62: ring groove, C: camber line, X: runner rotation axis

Claims (11)

With Lanna Boss,
A runner vane rotatably provided on the runner boss,
The runner boss includes a spherical outer peripheral surface, an upstream outer peripheral surface provided upstream of the central outer peripheral surface, and a downstream outer peripheral surface provided downstream of the central outer peripheral surface. Have
The upstream outer peripheral surface and the downstream outer peripheral surface are formed on the outer peripheral side than the extended surface of the central outer peripheral surface,
A concave portion is provided on the upstream outer peripheral surface or the downstream outer peripheral surface,
The runner vane has a central inner peripheral end surface formed in a spherical shape facing the central outer peripheral surface of the runner boss, and a vane extension portion that enters the recess when the angle of the runner vane reaches a maximum angle. Have
An inner peripheral end surface of the vane extension portion is a runner of a movable vane turbine, which is formed on an extended surface of the central inner peripheral end surface. The runner of the movable vane turbine according to claim 1, wherein the concave portion includes a bottom surface formed in a spherical shape on an extended surface of the central outer peripheral surface. A movable wall provided in the recess so as to be capable of advancing and retracting;
The runner of the movable vane turbine according to claim 1, further comprising: a movable wall driving unit that moves the movable wall into and out of the recessed portion.   The runner of the movable vane turbine according to claim 1 or 2, further comprising an elastic body filled in the recess. The runner vane further includes a spherical outer peripheral end surface facing a spherical inner peripheral surface of a discharge ring provided on the outer peripheral side of the runner, and a vane groove provided on the outer peripheral end surface,
The vane groove extends in a direction intersecting with a flow direction of a leakage flow formed in a gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring. The runner of the movable impeller water wheel as described in any one of Claims. The runner of the movable impeller turbine according to any one of claims 1 to 4,
A discharge ring provided on the outer peripheral side of the runner of the movable impeller, and
The discharge ring has a spherical inner peripheral surface formed in a spherical shape facing the outer peripheral end surface of the runner vane, and a ring groove provided in the spherical inner peripheral surface,
The ring groove is a movable impeller turbine that extends in a direction intersecting a flow direction of a leakage flow formed in a gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring. A runner of a movable vane turbine provided on the inner peripheral side of a discharge ring having a spherical inner peripheral surface formed in a spherical shape,
With Lanna Boss,
A runner vane rotatably provided on the runner boss,
The runner vane has a spherical outer peripheral end surface facing the spherical inner peripheral surface of the discharge ring, and a vane groove provided in the outer peripheral end surface,
The vane groove is a runner of a movable vane turbine that extends in a direction intersecting a flow direction of a leakage flow formed in a gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring.   The vane groove is disposed between an upstream end of the spherical inner peripheral surface of the discharge ring and a downstream end of the spherical inner peripheral surface in a direction along the rotation axis of the runner. The runner of the movable vane turbine described. A runner of the movable impeller water wheel according to any one of claims 1 to 5, 7 and 8,
A movable impeller turbine comprising: a discharge ring provided on an outer peripheral side of a runner of the movable impeller turbine. A discharge ring of a movable impeller turbine provided on the outer peripheral side of a runner having a runner boss and a runner vane including a runner vane formed in a spherical shape and rotatably provided on the runner boss,
A spherical inner peripheral surface formed in a spherical shape opposite to the outer peripheral end surface of the runner vane;
A ring groove provided on the spherical inner peripheral surface,
The ring groove extends in a direction intersecting a flow direction of a leakage flow formed in a gap between the outer peripheral end surface of the runner vane and the spherical inner peripheral surface of the discharge ring. . A discharge ring of the movable impeller turbine according to claim 10;
A movable impeller turbine comprising: the runner provided on an inner peripheral side of a discharge ring of the movable impeller turbine.

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