JP2012172556A - Axial-flow hydraulic turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial-flow hydraulic turbine capable of making the flow of pressurized water in runner vanes proper to suppress deterioration in efficiency.SOLUTION: The axial-flow hydraulic turbine 10 includes: a guide vane 24 provided in such a manner as to make its opening degree changeable; a tubular runner boss 40 coupled to a hydraulic turbine shaft 20; a plurality of runner vanes 50 provided at given intervals over a circumferential direction on a periphery of the runner boss 40; a runner 30 turned and driven by running water passing through the guide vane 24; and a suction pipe 26 provided at a downstream side of the runner 30. Each of the runner vanes 50 is divided into upper and lower portions. The upper runner vane 51 is fixed immovably on the periphery of the runner boss 40, while the lower runner vane 52 is turnably provided.

Description

  Embodiments of the present invention relate to an axial-flow turbine such as a propeller turbine including a runner vane fixed to a runner boss.

  Axial water turbines include propeller turbines, Kaplan turbines, and valve turbines. In the propeller turbine, the pressure water flowing into the casing through the iron pipe from the upper pond passes through the stay vane and the guide vane having an opening / closing function for adjusting the flow rate, and is rotatable and connected to the generator by the main shaft. It flows into the runner. The pressure water flowing into the runner rotates the runner to rotate the generator, passes through the suction pipe, and is discharged downstream or into the lower pond.

  Here, the runner includes a runner vane and a runner boss that supports the runner vane. The Kaplan turbine can move the entire runner vane. On the other hand, a runner vane in a propeller turbine is fixed to a runner boss by welding or bolt fastening.

  As an axial flow turbine, there are many applications such as a Kaplan turbine that can control the runner vane angle and the guide vane opening degree in an optimum state in accordance with the required load and operating head. However, when the water levels in the upper and lower ponds do not change much throughout the year and there is no change in the head or when there is no demand for load fluctuation, a propeller water turbine with a simple structure is used.

  As described above, the propeller turbine does not need to change the angle of the runner vanes according to the operating state, so that the outer shape of the runner boss need not be a spherical shape, and can be configured in a cylindrical shape. Further, since the operation mechanism for operating the entire runner vane is not provided inside the runner boss, the structure can be simplified and the runner boss can be downsized.

  On the other hand, the propeller turbine shows the same characteristics as the Francis turbine because the runner vanes are fixed hydraulically. For example, with the design condition (design point) as a boundary, the reduction in efficiency becomes remarkable under partial load conditions and overload conditions, and the runner vane outlet flow becomes uneven. It is known that a swirl flow called a whirl is generated in the central portion on the downstream side of the runner due to the non-uniform flow at the outlet of the runner vane.

  Under partial load conditions and overload conditions that deviate from the design point, the balance between the rotational speed of the runner and the speed of the pressure water in the runner is lost, and the swirling speed component at the outlet of the runner becomes dominant. Therefore, a spiral cavity having a pressure lower than the atmospheric pressure is generated in the central portion on the downstream side of the runner. This is a whirl. This whirl swings violently like a tornado with the central axis in the suction pipe as the vortex core, increasing the water pressure pulsation of the suction pipe. In addition, abnormal noise and vibration generated when this whirl collides with the inner wall of the pipe and collapses become a factor that hinders stable operation of the hydraulic machine.

Hydro Turbine, Turbomachinery Association, Nippon Kogyo Publishing, June 9, 2007 (revised edition), p.81-p.83

  As described above, an axial water turbine such as a propeller turbine with a fixed runner vane has problems such as occurrence of a whirl in a partial load condition or an overload condition to reduce efficiency and increase water pressure pulsation. ing.

  The problem to be solved by the present invention is to provide an axial-flow water turbine capable of optimizing the flow of pressure water in the runner vane and suppressing a decrease in efficiency.

  The axial water turbine according to the embodiment includes a guide vane provided with a variable opening degree, a cylindrical runner boss connected to one end of the rotating main shaft, and a predetermined interval in the circumferential direction on the outer periphery of the runner boss. And a runner that is rotationally driven by running water that has passed through the guide vane, and a suction pipe that is provided downstream of the runner. And each said runner vane is divided into 2 parts up and down, the upper side runner vane is fixed so that it may not move to the outer periphery of the said runner boss | hub, and the lower side runner vane is provided rotatably.

It is the figure which showed a part of axial flow water turbine of a 1st embodiment concerning the present invention by meridional section. It is a top view when the runner of the axial flow water turbine of a 1st embodiment concerning the present invention is seen from the ventral side of a runner vane. It is a figure which shows the AA cross section of FIG. 2 which showed the runner of the axial flow water turbine of 1st Embodiment which concerns on this invention. It is a figure which shows the cross section equivalent to the AA cross section of FIG. 2 for demonstrating operation | movement of the lower side runner vane in the runner of the axial flow water turbine of 1st Embodiment which concerns on this invention. In the axial turbine according to the first embodiment of the present invention, the relationship between the opening of the guide vane and the angle between the extension line of the camber line at the trailing edge of the lower runner vane and the vertical straight line is shown. FIG. It is a flowchart for demonstrating the control process for operating the lower side runner vane in the axial-flow water turbine of 1st Embodiment which concerns on this invention. It is the figure which showed the speed component (speed triangle) of each direction in the exit of a runner vane when the angle in the exit of a runner vane was made constant. It is a top view when the runner of the axial flow water turbine of a 2nd embodiment concerning the present invention is seen from the ventral side of a runner vane. It is a figure which shows the BB cross section of FIG. 8 which showed the runner of the axial-flow water turbine of 2nd Embodiment which concerns on this invention. It is a figure which shows the side surface of the runner boss | hub of the axial flow water turbine of 2nd Embodiment which concerns on this invention. It is a figure which shows the cross section equivalent to the BB cross section of FIG. 8 for demonstrating operation | movement of the lower side runner vane in the runner of the axial flow water turbine of 2nd Embodiment which concerns on this invention.

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

(First embodiment)
FIG. 1 is a diagram showing a part of an axial-flow water turbine 10 according to the first embodiment of the present invention in a meridional section. Here, a propeller turbine will be described as an example of the axial flow turbine 10. In the embodiments described below, the same components are denoted by the same reference numerals, and redundant description is omitted or simplified.

  As shown in FIG. 1, the axial-flow turbine 10 includes a turbine shaft 20 that functions as a rotary main shaft that extends directly downward and is directly connected to an upright generator (not shown). A runner 30 is attached to the tip of the water wheel shaft 20, and the runner 30 includes a runner boss 40 and a runner vane 50.

  A casing 22 is disposed on the outer periphery of the runner 30, and a plurality of stay vanes 23 are provided in the circumferential direction on the inner peripheral portion of the casing 22. A plurality of guide vanes 24 are arranged between the stay vanes 23 and the runner 30 in the circumferential direction. The guide vane 24 is provided so that the opening degree can be changed, and adjusts the flow rate of the pressure water led to the runner 30.

  On the outer periphery of the runner 30, a flow path pipe 25 that guides the pressure water that has passed through the guide vane 24 to the runner 30 is configured. A suction pipe 26 is provided at a lower end portion of the flow path pipe 25 and also on a downstream side of the runner 30.

  In the axial water turbine 10 having such a configuration, the pressure water introduced through the iron pipe from the upper pond passes through the casing 22 and the stay vane 23, passes through the guide vane 24 where the flow rate is adjusted, and goes to the runner 30. Led. In the runner 30, the pressure energy of the introduced pressure water is converted into rotational energy, and the runner 30 rotates about the water wheel shaft 20 as a rotation shaft, and rotates a generator (not shown) connected to the water wheel shaft 20. Generate electricity. Then, the pressure water that has passed through the runner 30 is discharged to the downstream basin through the suction pipe 26.

  Next, the structure of the runner 30 will be described in detail.

  FIG. 2 is a plan view when the runner 30 of the axial water turbine 10 according to the first embodiment of the present invention is viewed from the ventral side of the runner vane 50. In FIG. 2, in order to explain the structure inside the runner boss 40, a part is shown in cross section. Although a plurality of runner vanes 50 are provided, for convenience, FIG. 2 shows a single runner vane 50. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 showing the runner 30 of the axial water turbine 10 according to the first embodiment of the present invention.

  As shown in FIG. 2, the runner boss 40 includes a columnar runner boss main body 41 connected to the water wheel shaft 20 and a conical runner cone 42 connected to the lower end of the runner boss main body 41.

  A plurality of runner vanes 50 are provided on the outer periphery of the runner boss 40 at predetermined intervals in the circumferential direction. The runner vane 50 is divided into two parts in the vertical direction, and includes an upper runner vane 51 on the upper side and a lower runner vane 52 on the lower side. Here, one of the plurality of runner vanes 50 will be described, but the other runner vanes 50 have the same configuration.

  The upper runner vane 51 is fixed to the outer periphery of the runner boss main body 41 so as not to move by welding or bolt fastening. On the other hand, the lower runner vane 52 is rotatably provided so that the angle can be changed.

  Here, the structure which rotates the lower side runner vane 52 is demonstrated.

  As shown in FIG. 2, a rotation transmitting member 44 is disposed so as to penetrate through an opening 43 provided on the outer wall of the runner boss main body 41. One end side of the rotation transmitting member 44 is connected to the upper part of the side surface of the lower runner vane 52 on the runner boss main body 41 side. The other end side of the rotation transmission member 44 is connected to a rotation device 45 provided inside the runner boss 40. The lower runner vane 52 rotates about the central axis of the rotation transmission member 44 as the rotation axis M.

  As shown in FIGS. 2 and 3, a slight gap is provided between the upper runner vane 51 and the lower runner vane 52 so that the lower runner vane 52 can rotate. In order to suppress the increase of the gap and the protrusion of the upper portion of the lower runner vane 52 toward the blade surface when the lower runner vane 52 is rotated, the rotation shaft M is provided with the upper runner vane 51 and the lower runner vane 52. It is preferably configured at a position close to the center line L in the runner vane width direction at the center between them (the direction of the runner vane 50 from the inner peripheral side to the outer peripheral side in FIG. 2).

  For example, as shown in FIG. 2, one end side of the rotation transmission member 44 can be connected to the upper part of the side surface of the lower runner vane 52 so that the rotation axis M is close to the center line L. Further, for example, the rotation axis M may be provided in the runner vane width direction on the upper end surface (divided surface) of the lower runner vane 52. The rotation transmission member 44 is configured by, for example, a cylindrical member made of a metal material such as stainless cast steel.

  A slight gap is provided between the lower runner vane 52 and the runner boss body 41 so that the lower runner vane 52 can rotate. Since the runner 30 rotates in the flow path pipe 25, a slight gap is also provided between the runner vane 50 and the flow path pipe 25.

  The position where the runner vane 50 is divided into two in the vertical direction is a camber from the front edge 53 to the rear edge 54 in the runner vane 50 as shown in FIG. 3 because the flow angle of the pressure water flowing out from the runner 30 is easy to control. It is preferable that the line N is located closer to the trailing edge 54 than the center in the length direction. Further, the leading edge 53 of the lower runner vane 52 is configured so that even if a slight deviation occurs in the geometric angle of the inlet of the runner vane 50 with respect to the flow angle of the pressure water that flows in, there is no significant effect. Therefore, it is preferable to use a blunt head having a large radius of the inscribed circle at the front edge in the cross section shown in FIG.

  Here, the operation of the lower runner vane 52 will be described.

  FIG. 4 is a diagram showing a cross section corresponding to the AA cross section of FIG. 2 for explaining the operation of the lower runner vane 52 in the runner 30 of the axial water turbine 10 according to the first embodiment of the present invention. is there. In FIG. 4, the state where the lower runner vane 52 is not rotationally driven is indicated by the lower runner vane 52a, and the state where the lower runner vane 52 is rotationally driven is indicated by the lower runner vanes 52b and 52c. In addition, a camber line in a state where the lower runner vane 52 is not rotationally driven is indicated by Na, and a camber line in a state where the lower runner vane 52 is rotationally driven is indicated by Nb and Nc. Furthermore, the angles formed by the extended lines of the camber lines Na, Nb, and Nc and the straight lines in the vertical direction at the trailing edge of the lower runner vane 52 are indicated by θa, θb, and θc.

  As shown in FIG. 4, by driving the rotation device 45, the state of the lower runner vane 52a can be changed from the state of the lower runner vane 52a, for example. In this case, the angle θb becomes larger than the angle θa, and the velocity component in the circumferential direction of the pressure water increases.

  Further, by driving the rotation device 45, for example, the state of the lower runner vane 52a can be changed from the state of the lower runner vane 52a. In this case, the angle θc becomes smaller than the angle θa, and the velocity component in the axial direction (vertically downward direction) of the pressure water increases.

  For example, based on the flow rate of the pressure water guided to the runner 30, in other words, the opening degree of the guide vane 24, the lower runner vane can be changed to an optimum angle as described above.

  Next, an example in which a control device (not shown) for controlling the rotation device 45 is provided and this control device controls the rotation device 45 based on the opening degree of the guide vane 24 will be described. The control device is connected to the guide vane control device that controls the guide vane 24 and the guide vane 24 so as to be electrically communicable (communication possible), and is set to be able to input at least information related to the opening degree of the guide vane 24. ing. The control device is connected to the rotation device 45 so as to be electrically communicable (communication possible), and is set to be able to control at least the drive of the rotation device 45 based on information on the opening degree of the guide vane 24. ing. The control device may be configured integrally with the guide vane control device.

  FIG. 5 shows the opening of the guide vane 24, the extension line of the camber line N at the rear edge of the lower runner vane 52, and the straight line in the vertical direction in the axial flow turbine 10 of the first embodiment according to the present invention. It is the figure which showed the relationship with the angle | corner (theta) made. FIG. 6 is a flowchart for explaining a control process for operating the lower runner vane 52 in the axial water turbine 10 according to the first embodiment of the present invention.

  As shown in FIG. 5 as a database, the control device has a relationship between the opening of the guide vane 24 and the angle θ formed by the extension line of the camber line N and the vertical straight line at the trailing edge of the lower runner vane 52. Such information is stored in, for example, storage means. Furthermore, information relating to an output signal to the rotation device 45 for setting the predetermined angle θ is also stored in, for example, the storage means.

  The control device inputs information related to the opening degree of the guide vane 24 (step S60).

  Subsequently, the control device determines a corresponding angle of the lower runner vane 52 based on the information related to the opening degree of the guide vane 24 (step S61).

  Here, for example, when it is determined that the opening degree of the guide vane 24 is the design point based on the information related to the opening degree of the guide vane 24, the corresponding angle is determined as θa (FIGS. 4 and 5). reference). For example, when it is determined that the opening degree of the guide vane 24 is larger than the design point based on the information related to the opening degree of the guide vane 24, the corresponding angle is determined to be, for example, θc (see FIGS. 4 and 5). ). For example, when it is determined that the opening degree of the guide vane 24 is smaller than the design point based on the information related to the opening degree of the guide vane 24, the corresponding angle is determined to be, for example, θb (see FIGS. 4 and 5). ).

  Subsequently, the control device drives the rotation device 45 to set the lower runner vane 52 at the determined angle (step S62).

  Here, FIG. 7 is a diagram showing velocity components (velocity triangles) in each direction at the runner vane outlet when the angle at the runner vane outlet is constant.

  The relative flow angle α that is an angle from the circumferential direction at the outlet of the runner vane is constant because the flow flows out along the runner vane. The relative velocity component in this direction is indicated by W. That is, the angle formed by the circumferential speed component U and the relative speed component W is α.

  From the above, the magnitude of the relative velocity component W (the length of the arrow of the relative velocity component W in FIG. 7) changes with the change in the opening degree of the guide vane 24, that is, the change in the flow rate of the pressure water. The flow angle α is constant.

  Here, when the opening degree of the guide vane 24 is the design point, the relative speed component is represented by Wa, and the absolute speed component is represented by Va for closing the vector of the circumferential speed component U and the relative speed component Wa. At this set point, the angle formed by the absolute speed component Va and the circumferential speed component U is 90 degrees.

  The increase / decrease in the output of the water turbine is accompanied by the flow rate of the pressure water. For example, at the time of overload, the flow rate of the pressure water increases, so that the relative speed component becomes Wc and becomes the absolute speed component Vc. For example, when the load is low, the flow rate of the pressure water decreases, so the relative speed component becomes Wb and the absolute speed component Vb. Thus, when the opening degree of the guide vane 24 deviates from the rated condition as the design point, the angle formed by the absolute speed component and the circumferential speed component deviates from 90 degrees, and the direction of the absolute speed component is inclined. As a result, the speed component in the turning direction increases, turning loss increases, and efficiency decreases.

  Thus, when the angle at the runner vane outlet is constant, the flow at the runner vane outlet becomes non-uniform due to deviation from the design point, resulting in increased loss and reduced efficiency. Furthermore, water pressure pulsation increases as the velocity component in the turning direction increases.

  However, in the runner vane 50 in the axial water turbine 10 of the first embodiment, as described above, the lower runner vane 52 can be changed to an optimum angle, so that the absolute speed component and the circumferential speed component are formed. The angle can be set to an optimum angle such as 90 degrees. Thereby, the fall of efficiency and the increase in water pressure pulsation can be suppressed.

  As described above, according to the axial flow turbine 10 of the first embodiment, the runner vane 50 can be divided into two parts in the vertical direction, and the lower runner vane 52 can be changed to an optimum angle. An increase in water pressure pulsation can be suppressed.

(Second Embodiment)
Since the axial water turbine 10 of the second embodiment according to the present invention is different from the configuration of the axial water turbine 10 of the first embodiment only in the configuration for rotating the lower runner vane 52, here, The different configurations will be mainly described.

  FIG. 8 is a plan view when the runner 31 of the axial flow turbine 10 according to the second embodiment of the present invention is viewed from the ventral side of the runner vane 50. In FIG. 8, in order to explain the structure inside the runner boss 40, a part thereof is shown in cross section. Further, although a plurality of runner vanes 50 are provided, for convenience, FIG. 8 shows a single runner vane 50. FIG. 9 is a cross-sectional view taken along the line B-B of FIG. 8 showing the runner 31 of the axial water turbine 10 according to the second embodiment of the present invention. FIG. 10 is a diagram illustrating a side surface of the runner boss 40 of the axial-flow water turbine 10 according to the second embodiment of the present invention.

  A plurality of runner vanes 50 are provided on the outer periphery of the runner boss 40 at predetermined intervals in the circumferential direction. As shown in FIG. 8, the runner vane 50 is vertically divided into two parts, and is composed of an upper upper runner vane 51 and a lower lower runner vane 52. Here, one of the plurality of runner vanes 50 will be described, but the other runner vanes 50 have the same configuration.

  The upper runner vane 51 is fixed to the outer periphery of the runner boss main body 41 so as not to move by welding or bolt fastening. On the other hand, the lower runner vane 52 is rotatably provided so that the angle can be changed.

  As shown in FIG. 9, at the lower end portion of the upper runner vane 51 and the upper end portion of the lower runner vane 52, a stepped portion 70a that is concave in the width direction of the respective runner vanes on the abdominal side and the back side. , 70b are formed. Therefore, the lower end portion of the upper runner vane 51 and the upper end portion of the lower runner vane 52 are located at the center in the thickness direction of the respective runner vanes and along the width direction of each runner vane 71a. , 71b.

  As shown in FIG. 9, the upper side runner vane 52 and the lower side runner vane 52 of the upper side runner vane 51 and the lower side runner vane 52 can be rotated on the upper side runner vane 52 as shown in FIG. A plate-like elastic member 80 that functions as a support member supported by 51 is provided. The elastic member 80 is provided so as to fill the stepped portions 70 a and 70 b in the width direction of the runner vane 50. The ventral elastic member 80 is fixed from the ventral side to the ventral side surfaces of the protrusions 71a and 71b by, for example, bolt fastening. The back-side elastic member 80 is fixed from the back side to the back-side side surfaces of the protruding strip portions 71a and 71b by, for example, bolt fastening.

  As shown in FIG. 9, the lower runner vane 52 is supported by the upper runner vane 51 with a slight gap so that it can rotate. A slight gap is also provided between the lower runner vane 52 and the runner boss body 41 so that the lower runner vane 52 can rotate.

  The thickness of the elastic member 80 is set so that the outer outer surface of the elastic member 80 does not protrude from the abdomen and back wing surfaces of the runner vane 50 or is recessed. Here, the elastic member 80 is made of a material that can be deformed following the rotation of the lower runner vane 52 with the lower runner vane 52 supported by the upper runner vane 51 when the lower runner vane 52 is rotated. Is done. As the elastic member 80, for example, hard rubber or the like can be used.

  Here, the structure which rotates the lower side runner vane 52 is demonstrated.

  As shown in FIGS. 8 and 10, a rotation transmission member 47 is disposed so as to penetrate through an arc-shaped opening 46 provided on the outer wall of the runner boss main body 41. One end of the rotation transmitting member 47 is connected to the side surface of the lower runner vane 52 on the runner boss main body 41 side. The other end side of the rotation transmission member 47 is provided inside the runner boss 40 and is connected to a rotation device 48 that rotationally drives the rotation transmission member 47.

  The rotation transmission member 47 is constituted by a cylindrical member made of a metal material such as stainless cast steel, for example. The rotation device 48 is a device that moves the rotation transmission member 47 along the opening 46 provided on the outer wall of the runner boss body 41.

  For example, when the rotation transmitting member 47 moves the rotation transmitting member 47 along the opening 46, the lower runner vane 52 rotates about the support portion in the runner vane width direction supported by the elastic member 80.

  FIG. 11 is a diagram showing a cross-section corresponding to the BB cross section of FIG. 8 for explaining the operation of the lower runner vane 52 in the runner 31 of the axial water turbine 10 according to the second embodiment of the present invention. is there. In FIG. 11, the state where the lower runner vane 52 is not rotationally driven is indicated by the lower runner vane 52a, and the state where the lower runner vane 52 is rotationally driven is indicated by the lower runner vanes 52b and 52c.

  For example, when the rotation transmitting member 47 is moved upward along the opening 46 (above the opening 46 in FIG. 10), the lower runner vane 52b shown in FIG. On the other hand, when the rotation transmitting member 47 is moved downward along the opening 46 (below the opening 46 in FIG. 10), the lower runner vane 52c shown in FIG. In addition, the effect at the time of the lower side runner vane 52 becoming each state shown in FIG. 11 is the same as the effect demonstrated with reference to FIG. 4 in 1st Embodiment.

  The lower runner vane can be changed to an optimum angle as described above based on, for example, the flow rate of the pressure water guided to the runner 30, in other words, the opening degree of the guide vane 24.

  Moreover, the control apparatus which controls the rotation apparatus 48 is provided, and this control apparatus can also control the rotation apparatus 48 based on the opening degree of the guide vane 24. The control device is connected to the guide vane control device that controls the guide vane 24 and the guide vane 24 so as to be electrically communicable (communication possible), and is set to be able to input at least information related to the opening degree of the guide vane 24. ing. Further, the control device is connected to the rotation device 48 so as to be electrically communicable (communication possible), and is set so as to be able to control at least the drive of the rotation device 48 based on information on the opening degree of the guide vane 24. ing. The control device may be configured integrally with the guide vane control device.

  The operation of the control device is the same as the operation of the control device described in the first embodiment, and the same operational effects as the operational effects in the first embodiment can be obtained.

  As described above, according to the axial water turbine 10 of the second embodiment, the runner vane 50 can be divided into two parts up and down, and the lower runner vane 52 can be changed to an optimum angle, resulting in a decrease in efficiency, An increase in water pressure pulsation can be suppressed.

  According to the embodiment described above, it is possible to optimize the flow of pressure water in the runner vanes and suppress a decrease in efficiency.

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.

  DESCRIPTION OF SYMBOLS 10 ... Axial water wheel, 20 ... Water wheel shaft, 22 ... Casing, 23 ... Stay vane, 24 ... Guide vane, 25 ... Channel piping, 26 ... Drain pipe, 30, 31 ... Runner, 40 ... Runner boss, 41 ... Runner boss main body, 42 ... runner cones, 43, 46 ... openings, 44, 47 ... rotation transmission members, 45, 48 ... rotation devices, 50 ... runner vanes, 51 ... upper runner vanes, 52, 52a, 52b, 52c ... lower runner vanes, 53 ... Front edge, 54 ... Rear edge, 70a ... Step portion, 71a ... Round portion, 71b ... Round portion, 80 ... Elastic member, L ... Center line, M ... Rotary shaft, N, Na, Nb, Nc ... Camber line.

Claims (5)

A guide vane provided so that the opening can be changed;
A cylindrical runner boss connected to one end of the rotation main shaft, and a plurality of runner vanes provided on the outer periphery of the runner boss at predetermined intervals in the circumferential direction. A driven runner,
A suction pipe provided downstream of the runner,
Each of the runner vanes is vertically divided into two, the upper runner vanes are fixed so as not to be movable on the outer periphery of the runner boss, and the lower runner vanes are rotatably provided. A rotating device provided inside the runner boss;
A rotation transmission member disposed through the opening provided on the outer wall of the runner boss, having one end connected to the lower runner vane and the other end connected to the rotation device;
The axial-flow water turbine according to claim 1, wherein the rotation transmission member is rotated by the rotation device to rotate the lower runner vane. A support member that rotatably supports the lower runner vane, and supports an upper end of the lower runner vane on a lower end of the upper runner vane;
A rotating device provided inside the runner boss;
A rotation transmission member disposed through an arc-shaped opening provided on the outer wall of the runner boss, having one end connected to the lower runner vane and the other end connected to the rotation device;
The axial-flow water turbine according to claim 1, wherein the rotation transmission member is moved along the opening by the rotation device to rotate the lower runner vane.   The axial flow water turbine according to claim 3, wherein the support member is made of an elastic member. It is possible to input information relating to the opening degree of the guide vane, and includes a control means for controlling the rotating device,
The said control means drives the said rotation apparatus based on the information which concerns on the opening degree of the said guide vane, The angle of the said lower side runner vane is changed, The any one of Claim 2 thru | or 4 characterized by the above-mentioned. The described axial-flow turbine.

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