JP6670736B2 - Hydraulic machine and its operation method - Google Patents

Description

  Embodiments of the present invention relate to a hydraulic machine and a method of operating the same.

  As an example of a hydraulic machine, a Francis type pump turbine is known. In the Francis type pump-turbine, water from the casing flows into the runner through the stay vanes and the guide vanes during operation of the turbine. The runner is rotationally driven by the water flow from the guide vanes, and thereby the generator motor is driven via the main shaft. And the water which rotated the runner is guided to a drainage channel or a lower pond via a suction pipe. On the other hand, during the pump operation (during the pumping operation), the generator motor rotates the runner in a direction opposite to that during the operation of the water wheel. Thereby, the water from the suction pipe is pumped to the upper pond via the runner, the guide vanes, the stay vanes, and the casing.

  During the pumping operation of such a Francis type pump-turbine, a backflow phenomenon may occur on the high head side as in the case of the centrifugal pump. When operating in the flow rate range where the backflow phenomenon can occur, the hump phenomenon, that is, the phenomenon that the flow rate fluctuates, may occur due to the presence of a plurality of operating points on the same head, and abnormal water hammer and abnormal vibration may occur. It is easy to occur. Therefore, in order to avoid such a hump phenomenon, a method of narrowing the opening degree of the guide vane is generally used.

  FIG. 15 is a performance diagram showing the relationship between the flow rate and the head during the pumping operation of a general Francis pump-turbine. In FIG. 15, reference numeral X indicates a performance curve of a general Francis type pump-turbine when the guide vane is operated at the on-cam point and operated. In the performance curve X, a backflow occurrence point where a backflow phenomenon can occur exists in a range on the high-lift side indicated by reference numeral A1 surrounded by a dashed line. A solid-line rectangular range indicated by reference numeral Au in the drawing indicates an operation range. This operation range Au is a range defined with a predetermined amount of operation margin with respect to the backflow occurrence point, and defines a range in which a proper pumping operation can be performed. The upper limit of the head permitted in the operation range Au is called a maximum head, and the lower limit is called a minimum head. The upper limit of the flow rate allowed in the operation range Au is called a maximum flow, and the lower limit is called the minimum flow.

  In order to avoid the hump phenomenon, when the above-described method of reducing the guide vane opening is used, the performance curve X may be changed to a performance curve Xc located on the lower flow rate side and higher head side. it can. Thereby, as shown by the arrow in the figure, the backflow occurrence point can be shifted to the high head side. As a result, in the state after the opening degree of the guide vane is reduced, even when the operation is performed at the backflow generation point on the performance diagram X or at the operation point in the vicinity thereof, it is possible to suppress the occurrence of the hump phenomenon. It becomes possible.

  However, in the technique of reducing the opening degree of the guide vane as described above, the operation of the guide vane deviating from the on-cam point causes a problem that the operation efficiency and the pumping amount during the pumping operation are reduced.

JP 2013-092156 A

  The present invention has been made in consideration of the above-described circumstances, and in pumping operation, while maintaining the guide vanes at the on-cam point, only the backflow occurrence point is partially moved away from the high head side or the backflow occurrence point is eliminated. An object of the present invention is to provide a hydraulic machine and a method for operating the hydraulic machine, which can improve the problem of the backflow point while suppressing a decrease in operation efficiency.

  In the hydraulic machine according to the embodiment, a guide vane and a stay vane are arranged between a runner and a casing, and by rotating the runner, water flows from the runner side to the casing side via the guide vane and the stay vane. And a flow rate adjusting mechanism for selectively increasing the flow rate of water flowing radially outside the outer diameter side wing surface of the guide vane.

  Further, in the operation method of the hydraulic machine according to the embodiment, a guide vane and a stay vane are arranged between a runner and a casing, and by rotating the runner, the guide vane and the stay vane pass through the guide vane and the stay vane from the runner side. This is a method of operating a hydraulic machine that pumps water to the casing side. This operation method includes a flow rate adjusting step for selectively increasing the flow rate of water flowing radially outside the outer diameter side blade surface of the guide vane.

  ADVANTAGE OF THE INVENTION According to this invention, in pumping operation, while maintaining a guide vane at an on-cam point, only a backflow generation point can be partially moved away to the high head side, or a backflow generation point can be eliminated, thereby reducing operating efficiency. And the problem of the backflow point can be improved while suppressing the occurrence of the backflow.

It is a meridional sectional view of the Francis type pump turbine according to the first embodiment. It is a figure explaining the flow control mechanism of the Francis type pump turbine shown in Drawing 1, (A) is a figure showing the state before flow control by the flow control mechanism, and (B) is the state after flow control. FIG. FIG. 2 is a diagram showing a performance diagram showing a relationship between a flow rate and a head during a pumping operation of the Francis pump-turbine shown in FIG. 1. It is a meridional sectional view of the Francis type pump turbine according to the second embodiment. It is the figure which looked at the guide vane and lower cover of the Francis type pump turbine shown in Drawing 4 along the runner axis of rotation, and is a figure explaining the flow control mechanism concerning a 2nd embodiment. It is a meridional sectional view of the Francis type pump-turbine according to the third embodiment. It is the figure which looked at the guide vane and lower cover of the Francis type pump turbine shown in Drawing 6 along the runner rotation axis downward, and is a figure explaining the flow control mechanism concerning a 3rd embodiment. It is a meridional sectional view of a Francis type pump turbine according to a fourth embodiment. It is the figure which looked at the guide vane and lower cover of the Francis type pump-turbine shown in FIG. 8 below along the runner rotation axis, and is a figure explaining the flow control mechanism which concerns on 4th Embodiment. It is a meridional sectional view of the Francis type pump turbine according to the fifth embodiment. It is the figure which looked at the guide vane and lower cover of the Francis type pump-turbine shown in FIG. 10 below along the runner rotation axis, and is a figure explaining the flow control mechanism which concerns on 5th Embodiment. It is a figure which shows the guide vane and flow control mechanism of the Francis type pump-turbine which concerns on 6th Embodiment, (A) is a figure which shows the state before the flow control by a flow control mechanism, (B) is a figure. FIG. 7 is a diagram showing a state after flow rate adjustment. (A) is a meridional sectional view of a Francis type pump turbine according to a seventh embodiment, and (B) is a diagram showing a guide vane and a lower cover of the Francis type pump turbine shown in (A) along a runner rotation axis. FIG. It is a meridional sectional view of a Francis type pump turbine according to an eighth embodiment. FIG. 4 is a diagram showing a performance diagram illustrating a relationship between a flow rate and a head during a pumping operation of a general Francis type pump-turbine.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, description of the same items as those described with reference to FIG. 15 may be omitted.

(First Embodiment)
FIG. 1 shows a Francis-type pump-turbine 1 as an example of a hydraulic machine according to a first embodiment of the present invention. In the following description, the Francis pump-turbine 1 will be simply referred to as the turbine 1. The water turbine 1 includes a casing 10 into which water flows from an upper pond (not shown) through an iron pipe during operation of the water turbine, a plurality of guide vanes 12 and stay vanes 13, and a runner 14.

  In the water turbine 1, water from the casing 10 flows into the runner 14 through the stationary cascade flow path constituted by the guide vanes 12 and the stay vanes 13 during operation of the water turbine. Thus, the runner 14 rotates around the runner rotation axis C1. In the following description, when simply referred to as an axial direction, the direction means a direction on the runner rotation axis C1 or a direction along the runner rotation axis C1. In this example, the axial direction extends along the up-down direction. Further, the term circumferential direction means a direction along the direction in which the runner 14 rotates about the runner rotation axis C1, and the term radial direction means a direction orthogonal to the runner rotation axis C1. .

  The casing 10 is formed in a spiral shape, and supplies water supplied from the upper pond to the runner 14 through the stay vanes 13 and the guide vanes 12 during operation of the water turbine. The plurality of stay vanes 13 are members that allow the water supplied from the casing 10 to flow into the guide vanes 12, and are arranged at predetermined intervals in the circumferential direction inside the casing 10 in the radial direction. The plurality of guide vanes 12 are members that allow the water flowing from the stay vanes 13 to flow into the runners 14, are arranged at predetermined intervals in the circumferential direction inside the stay vanes 13 in the radial direction, and are disposed radially outside the runners 14. Are located. That is, the guide vane 12 and the stay vane 13 are arranged between the runner 14 and the casing 10 in the radial direction.

  Reference numeral 18U in FIG. 1 indicates an upper cover 18U disposed above the guide vane 12, and reference numeral 18D indicates a lower cover 18D disposed below the guide vane 12. In the present embodiment, the upper cover 18U has an outer diameter side cover 18U1 that covers the upper part of the guide vane 12, and an inner diameter side cover 18U2 that covers the upper part (crown) of the runner 14. The lower cover 18D has an outer diameter side cover 18D1 that covers the lower part of the guide vane 12, and an inner diameter side cover 18D2 that covers the lower part (band) of the runner 14. Of these, the outer diameter side cover portion 18U1 and the outer diameter side cover portion 18D1 are respectively connected to ring bodies located above and below the stay vane 13, so that a flow path between the runner 14 and the casing 10 is formed. The guide vane 12 and the stay vane 13 are located in the road.

  The runner 14 is configured to rotate about the runner rotation axis C1 with respect to the casing 10, and the runner rotation axis C1 is connected to a generator motor (not shown) via a main shaft 15 passing through the center. In the water wheel operation, the generator motor generates electric power by being rotated by the runner 14. Here, a guide vane spindle 22 is connected to the guide vane 12, and in the illustrated example, the guide vane spindle 22 penetrates the outer diameter side cover portion 18U1 of the upper cover 18U. The guide vane 12 is rotatable around a guide vane rotation axis L1 extending on the central axis of the guide vane spindle 22, and by changing its angle by rotation, a flow path formed between the adjacent guide vanes 12 Can be changed. This makes it possible to adjust the power generation output by changing the amount of water to the runner 14.

  On the other hand, the pumping operation (pump operation) is performed by rotating the runner 14 by the generator motor. In the pumping operation, the generator motor rotates the runner 14 in a direction opposite to that in the operation of the turbine. As a result, water from a suction pipe (not shown) provided below the runner 14 is pumped from the runner 14 to the casing 10 via the guide vanes 12 and the stay vanes 13.

  FIG. 2 is a diagram illustrating a flow rate adjusting mechanism 30 provided in the water turbine 1 according to the present embodiment. The flow rate adjustment mechanism 30 can selectively increase the flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12. FIG. 2A is a diagram illustrating a state before the flow rate adjustment by the flow rate adjusting mechanism 30, and FIG. 2B is a diagram illustrating a state after the flow rate adjustment. Note that the outer diameter side wing surface 12 </ b> A of the guide vane 12 means a wing surface facing a radially outer side of a pair of wing surfaces reaching a leading edge and a trailing edge of the guide vane 12.

  In the present embodiment, the outer diameter side cover 18U1 of the upper cover 18U is held so as to be movable along the axial direction of the guide vane rotation axis L1, and the outer diameter side cover 18D1 of the lower cover 18D is rotated by the guide vane. It is held movably along the axial direction of the axis L1. The flow rate adjusting mechanism 30 can selectively move the outer diameter side cover portion 18U1 and the outer diameter side cover portion 18D1 toward and away from the guide vane 12 in the axial direction of the guide vane rotation axis L1. I have. Thereby, the flow rate adjusting mechanism 30 can selectively increase the flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 during the pumping operation.

  More specifically, in FIG. 2A, each of the gap between the upper cover 18U and the guide vane 12 and the gap between the lower cover 18D and the guide vane 12 is a distance G1 suitable for normal pumping operation. , G1 '. From the state shown in FIG. 2 (A), the outer diameter side cover 18U1 and the outer diameter side cover 18D1 are separated from the guide vane 12 by the flow rate adjusting mechanism 30, as shown in FIG. 2 (B). The gap between the upper cover 18U and the guide vane 12 can be increased to a distance G2 greater than the distance G1, and the gap between the lower cover 18D and the guide vane 12 can be increased to a distance G2 'greater than the distance G1'. it can. This makes it possible to increase the flow rate of water flowing from the inside to the outside in the radial direction through the gap between the guide vanes 12 at the distances G2 and G2 'than before adjustment.

  The flow rate adjusting mechanism 30 in the present embodiment is configured such that, when the flow rate during the pumping operation is equal to or more than a predetermined flow rate, or when the pressure of water flowing radially outside the outer wing surface 12A of the guide vane 12 is equal to the predetermined pressure. In the following cases, the upper cover 18U and the lower cover 18D are configured to be separated from the guide vane 12. Specifically, the water pressure as a reference when the upper cover 18U and the lower cover 18D are separated from the guide vane 12 flows at a position radially outside the outer diameter side blade surface 12A in the cascade of the guide vanes 12. Water pressure. The reference water pressure is preferably the pressure of the water flowing near the runner 14 among the water flowing radially outside the outer diameter side blade surface 12A.

  Further, the flow rate adjusting mechanism 30 in the present embodiment has an actuator 31 for moving the upper cover 18U and an actuator 31 for moving the lower cover 18D. These actuators 31 may be constituted by a pneumatic device, may be constituted by a hydraulic device, may be constituted by a ball screw, an electric motor, or the like.

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

  When the pumping operation is performed, the generator motor rotates the runner 14, so that water from a suction pipe provided below the runner 14 is pumped from the runner 14 side to the casing 10 side via the guide vane 12 and the stay vane 13. You. Thereafter, the water flowing into the casing 10 is led to the upper pond through an iron pipe (not shown).

  FIG. 3 is a performance diagram showing the relationship between the flow rate and the head during the pumping operation of the water turbine 1. In FIG. 3, symbol Y indicates a performance curve of the water turbine 1 when the pump vane operation is performed while the guide vane 12 is maintained at the on-cam point and the flow rate adjusting mechanism 30 is not operated. In the performance curve Y, a backflow occurrence point exists in a range on the high-lift side indicated by reference numeral B1 surrounded by a dashed line. Further, the range of the solid-line rectangle indicated by the symbol Bu in the drawing indicates the operation range. The operation range Bu is defined with a predetermined amount of operation margin with respect to the backflow occurrence point.

  In the present embodiment, when the operation state of the water turbine 1 becomes the backflow generation point or the operation point in the vicinity thereof, the flow rate adjusting mechanism 30 causes the outer diameter side cover portion 18U1 and the outer diameter side cover portion 18D1 to guide the vane. By separating the guide vanes 12 from each other, it is possible to increase the flow rate of water flowing radially outside the outer-side blade surface 12A of the guide vane 12. As a result, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to a position on the curve of the two-dot chain line on the high head side, and can be further separated from the operation range Bu.

  This is because the backflow phenomenon at the time of the pumping operation is caused by the separation of the outer wing surface 12A of the guide vane 12 on the radially outer side, which occurs when the inlet angle of the guide vane 12 does not coincide with the inflow angle of water. Therefore, by increasing the amount of water in the low-pressure region, which is a cause of the separation, the separation can be suppressed and the occurrence of the backflow phenomenon can be delayed or eliminated. Note that the flow point may be used as a reference for operating the flow rate adjusting mechanism 30 at the backflow generation point or in the vicinity thereof, which is a reference for operating the flow adjustment mechanism 30. Specifically, a predetermined flow rate as a reference when operating the flow rate adjusting mechanism 30 may be set between the inflection point downward of the performance curve Y and the minimum flow rate in the operation range Bu.

  Further, in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, according to the water turbine 1 according to the present embodiment, in the pumping operation, while maintaining the guide vane 12 at the on-cam point, only the backflow occurrence point is partially moved away to the high head side or the backflow occurrence point is eliminated. Thus, the problem of the backflow point can be improved while suppressing a decrease in the operating efficiency. In the present embodiment, by increasing the flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12, the backflow generation point is shifted to the high head side as shown in FIG. However, depending on the conditions, the backflow point may be eliminated. Eliminating the backflow occurrence point means that there is no inflection point where the slope changes downward and no inflection point where the inclination changes upward on the performance curve.

  Further, in the present embodiment, the outer diameter side cover portion 18U1 of the upper cover 18U and the outer diameter side cover portion 18D1 of the lower cover 18D are moved toward and away from the guide vane 12. The entirety and the entirety of the lower cover 18D may be moved. In the present embodiment, both the outer diameter side cover portion 18U1 of the upper cover 18U and the outer diameter side cover portion 18D1 of the lower cover 18D are movable, but one of them is movable. Is also good.

(Second embodiment)
Next, a second embodiment will be described. FIG. 4 is a meridional sectional view of the Francis pump turbine according to the second embodiment, and FIG. 5 is a diagram illustrating the guide vanes and the lower cover of the Francis pump turbine shown in FIG. It is the figure which saw, and is a figure explaining the flow control mechanism concerning a 2nd embodiment. The same components as those of the above-described first embodiment in the present embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, the flow rate adjusting mechanism 30 has a water supply hole 41 opened on the outer diameter side wing surface 12A of the guide vane 12, and selectively supplies water from the water supply hole 41 to the outside. Is configured to selectively increase the flow rate of water flowing radially outside the outer diameter side wing surface 12A.

  Specifically, as shown in FIG. 4, the water supply hole 41 includes an upstream channel portion 41 </ b> A that extends along the guide vane rotation axis L <b> 1 over the guide vane spindle 22 and the guide vane 12, and an upstream channel portion. 41A, a plurality of downstream flow passage portions 41B branched from a portion inside the guide vane 12 in 41A. The upstream flow path portion 41A is connected to a water supply source (not shown). The water supply source may be the casing 10 or an iron pipe. In the illustrated example, each of the downstream flow passage portions 41B is open at a portion of the outer diameter side wing surface 12A near the runner 14, and is arranged vertically. The shape of the opening edge of the downstream flow path portion 41B is circular, but may be a slit shape or the like.

  The water supply holes 41 are preferably provided in half or all of the plurality of guide vanes 12 arranged in the circumferential direction. In the present embodiment, water supply holes 41 are provided in all of the plurality of guide vanes 12. When the water supply holes 41 are provided in half of the plurality of guide vanes 12, it is preferable that the plurality of guide vanes 12 having the water supply holes 41 and those not having the water supply holes 41 be alternately arranged.

  Further, as shown in FIG. 5, in the present embodiment, an on-off valve 42 is provided near the opening edge of the downstream flow path portion 41B. Thereby, in the flow rate adjusting mechanism 30 in the present embodiment, by opening the on-off valve 42, water can be selectively supplied from the water supply hole 41 to the radially outer side of the outer blade side 12A of the guide vane 12 in the radial direction. The flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 can be selectively increased. Here, the on-off valve 42 may be opened by a pressure drop of water flowing radially outside the outer blade surface 12A of the guide vane 12, or may be opened by an external input. Good. Further, the on-off valve 42 may be configured to be capable of adjusting the flow rate of the water to be passed.

  In the present embodiment as described above, when the operating state of the water turbine 1 at the time of pumping operation becomes the operating point at or near the backflow generation point, the on-off valve 42 of the flow rate adjusting mechanism 30 is opened to open the water supply hole. By supplying water from the outside 41 to the radially outer side of the outer diameter side wing surface 12A, it is possible to increase the flow rate of water flowing on the outer side of the outer diameter side wing surface 12A of the guide vane 12 in the radial direction. Thereby, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to the high head side or eliminated. In a normal operation state such as an operation in the operation range Bu shown in FIG. 3, by closing the on-off valve 42, it is possible to avoid an undesirable decrease in efficiency due to water supply.

  Also in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, also in the present embodiment, in the pumping operation, it is possible to partially move only the backflow generation point to the high head side or eliminate the backflow generation point while maintaining the guide vane 12 at the on-cam point, and thereby, The problem of the backflow generation point can be improved while suppressing a decrease in the operation efficiency.

(Third embodiment)
Next, a third embodiment will be described. FIG. 6 is a meridional sectional view of a Francis type pump turbine according to the third embodiment. FIG. 7 is a diagram showing a guide vane and a lower cover of the Francis type pump turbine shown in FIG. FIG. 14 is a view illustrating a flow rate adjusting mechanism according to a third embodiment. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the present embodiment, the flow rate adjusting mechanism 30 has the water supply holes 41 opened in the upper cover 18U and the lower cover 18D, and selectively supplies water from the water supply holes 41 to the outside. Is configured to selectively increase the flow rate of water flowing radially outside the outer diameter side wing surface 12A.

  Specifically, as shown in FIG. 6, the water supply hole 41 provided in the upper cover 18U penetrates the upper cover 18U along the guide vane rotation axis L1, and the water supply hole 41 provided in the lower cover 18D , The lower cover 18D penetrates along the guide vane rotation axis L1. Each of the upper and lower water supply holes 41 is connected to a water supply source (not shown). The water supply source may be the casing 10 or an iron pipe.

  FIG. 7 shows a state where the guide vane 12 is at the on-cam point. More specifically, this on-cam point is an on-cam point corresponding to the operating point at which the operation range Bu has the highest head in the operation according to the performance curve Y in FIG. Here, as shown in FIG. 7, when the guide vane 12 is at the above-described on-cam point, the lower water supply hole 41 faces the end face of the guide vane 12 on the side of the lower cover 18D. The shape of the opening edge of the water supply hole 41 is circular, but may be a slit shape or the like. Although not shown, the upper water supply hole 41 faces the end surface of the guide vane 12 on the side of the upper cover 18U when the guide vane 12 is at the above-described on-cam point.

  Further, it is preferable that the water supply holes 41 are provided corresponding to half or all of the plurality of guide vanes 12 arranged side by side in the circumferential direction. In the present embodiment, water supply holes 41 are provided corresponding to all of the plurality of guide vanes 12. Further, in the present embodiment, as shown in FIG. 7, two water supply holes 41 are provided in each of the upper cover 18U and the lower cover 18D for one guide vane 12, but such a number is particularly limited. It is not something that can be done. 6, one of the two water supply holes 41 provided in each of the upper cover 18U and the lower cover 18D corresponding to one guide vane 12 is omitted for convenience of description.

  As shown in FIGS. 6 and 7, in the present embodiment, an on-off valve 42 is provided near the opening edge of the water supply hole 41. Thereby, in the flow rate adjusting mechanism 30 in the present embodiment, by opening the on-off valve 42, water can be selectively supplied from the water supply hole 41 to the radially outer side of the outer blade side 12A of the guide vane 12 in the radial direction. The flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 can be selectively increased. Here, the on-off valve 42 may be opened by a pressure drop of water flowing radially outside the outer blade surface 12A of the guide vane 12, or may be opened by an external input. Good. Further, the on-off valve 42 may be configured to be capable of adjusting the flow rate of the water to be passed.

  In the present embodiment as described above, when the operating state of the water turbine 1 at the time of pumping operation becomes the operating point at or near the backflow generation point, the on-off valve 42 of the flow rate adjusting mechanism 30 is opened to open the water supply hole. By supplying water from the outside 41 to the radially outer side of the outer diameter side wing surface 12A, it is possible to increase the flow rate of water flowing on the outer side of the outer diameter side wing surface 12A of the guide vane 12 in the radial direction. Thereby, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to the high head side or eliminated. In a normal operation state such as an operation in the operation range Bu shown in FIG. 3, by closing the on-off valve 42, it is possible to avoid an undesirable decrease in efficiency due to water supply.

  Also in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, also in the present embodiment, in the pumping operation, it is possible to partially move only the backflow generation point to the high head side or eliminate the backflow generation point while maintaining the guide vane 12 at the on-cam point, and thereby, The problem of the backflow generation point can be improved while suppressing a decrease in the operation efficiency.

  In the present embodiment, the water supply hole 41 faces the end surface of the guide vane 12 on the upper cover 18U side or the lower cover 18D side when the guide vane 12 is at the on-cam point. The hole 41 may be opened at a position radially outside the outer blade surface 12A of the guide vane 12 when the guide vane 12 is at the on-cam point. Further, in the present embodiment, the water supply holes 41 are provided in both the upper cover 18U and the lower cover 18D, but a configuration in which the water supply holes 41 are provided in one of the upper cover 18U and the lower cover 18D may be employed. Good.

(Fourth embodiment)
Next, a fourth embodiment will be described. FIG. 8 is a meridional sectional view of a Francis type pump turbine according to the fourth embodiment. FIG. 9 is a diagram illustrating a guide vane and a lower cover of the Francis type pump turbine shown in FIG. It is the figure which saw and is a figure explaining the flow control mechanism concerning a 4th embodiment. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  In the present embodiment, the flow rate adjusting mechanism 30 has a water supply hole 41 penetrating from the inner diameter side wing surface 12B of the guide vane 12 to the outer diameter side wing surface 12A, and an on-off valve 42 provided in the water supply hole 41. By opening the on-off valve 42 and selectively supplying water radially outward from the water supply hole 41, the flow rate of water flowing radially outward of the outer-side blade surface 12A of the guide vane 12 is selectively increased. It is configured as follows.

  Specifically, as shown in FIG. 9, the water supply hole 41 penetrates from a portion of the inner diameter side blade surface 12B closer to the runner 14 to a portion of the outer diameter side blade surface 12A closer to the runner 14. Further, as shown in FIG. 8, the water supply holes 41 are arranged in a vertical direction. The cross-sectional shape of the water supply hole 41 is circular, but may be a slit shape or the like (rectangular shape).

  Further, it is preferable that the water supply holes 41 are provided in half or all of the plurality of guide vanes 12 arranged in the circumferential direction. In the present embodiment, water supply holes 41 are provided in all of the plurality of guide vanes 12. In the present embodiment, as shown in FIG. 8, four water supply holes 41 are provided for one guide vane 12, but such a number is not particularly limited.

  In the flow rate adjusting mechanism 30 according to the present embodiment, by opening the on-off valve 42, the water flowing inside the radially inner wing surface 12 </ b> B of the guide vane 12 to the radially outer side of the outer blade side 12 </ b> A of the guide vane 12. It can be selectively supplied, and the flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 can be selectively increased. Here, the on-off valve 42 may be opened by a pressure drop of water flowing radially outside the outer blade surface 12A of the guide vane 12, or may be opened by an external input. Good. Further, the on-off valve 42 may be configured to be capable of adjusting the flow rate of the water to be passed.

  In the present embodiment as described above, when the operating state of the water turbine 1 at the time of pumping operation becomes the operating point at or near the backflow generation point, the on-off valve 42 of the flow rate adjusting mechanism 30 is opened to open the water supply hole. By supplying water from the outside 41 to the radially outer side of the outer diameter side wing surface 12A, it is possible to increase the flow rate of water flowing on the outer side of the outer diameter side wing surface 12A of the guide vane 12 in the radial direction. Thereby, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to the high head side or eliminated. In a normal operation state such as an operation in the operation range Bu shown in FIG. 3, by closing the on-off valve 42, it is possible to avoid an undesirable decrease in efficiency due to water supply.

  Also in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, also in the present embodiment, in the pumping operation, it is possible to partially move only the backflow generation point to the high head side or eliminate the backflow generation point while maintaining the guide vane 12 at the on-cam point, and thereby, The problem of the backflow generation point can be improved while suppressing a decrease in the operation efficiency.

(Fifth embodiment)
Next, a fifth embodiment will be described. FIG. 10 is a meridional sectional view of a Francis pump turbine according to a fifth embodiment, and FIG. 11 is a diagram illustrating a guide vane and a lower cover of the Francis pump turbine shown in FIG. FIG. 14 is a view illustrating a flow rate adjusting mechanism according to a fifth embodiment. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIGS. 10 and 11, in the present embodiment, the flow rate adjusting mechanism 30 includes a water supply hole 41 provided in each of the upper cover 18 </ b> U and the lower cover 18 </ b> D, and an on-off valve provided in the water supply hole 41. 42. When the guide vane 12 is at the on-cam point, one end of each water supply hole 41 is opened at a position radially inward of the inner-side blade surface 12B of the guide vane 12 and the diameter of the outer-side blade surface 12A of the guide vane 12 is increased. The other end is opened at a position outside the direction. Then, the flow rate adjusting mechanism 30 opens the on-off valve 42 and selectively supplies water flowing radially inside the inner diameter side wing surface 12B of the guide vane 12 to the radially outer side of the outer diameter side wing surface 12A. It is configured to selectively increase the flow rate of water flowing radially outside the outer diameter side wing surface 12A of the wing 12.

  The above-mentioned on-cam point is an on-cam point corresponding to the operating point at which the operation range Bu has the highest head in the operation according to the performance curve Y in FIG. As shown in FIG. 11, a water supply hole 41 provided in the lower cover 18 </ b> D is provided so as to straddle the guide vane 12 at a portion of the guide vane 12 near the runner 14. Although not shown, a water supply hole 41 provided in the upper cover 18U is also provided so as to straddle the guide vane 12 at a portion of the guide vane 12 near the runner 14. The water supply holes 41 are preferably provided corresponding to half or all of the plurality of guide vanes 12 arranged in the circumferential direction. In the present embodiment, water supply holes 41 are provided corresponding to all of the plurality of guide vanes 12. Further, in the present embodiment, as shown in FIG. 11, two water supply holes 41 are provided in each of the upper cover 18U and the lower cover 18D for one guide vane 12, but such a number is particularly limited. It is not something that can be done. In FIG. 10, one of two water supply holes 41 provided in each of the upper cover 18U and the lower cover 18D corresponding to one guide vane 12 is omitted for convenience of description.

  As shown in FIGS. 10 and 11, in the present embodiment, an on-off valve 42 is provided near the opening edge of the water supply hole 41 on the outer diameter side wing surface 12A side. Thus, in the flow rate adjusting mechanism 30 according to the present embodiment, by opening the on-off valve 42, the water flowing radially inside the inner diameter side blade surface 12B of the guide vane 12 is reduced in diameter by the outer diameter side blade surface 12A of the guide vane 12. It can be selectively supplied to the outside in the direction, and the flow rate of water flowing radially outside the outer-side blade surface 12A of the guide vane 12 can be selectively increased. Here, the on-off valve 42 may be opened by a pressure drop of water flowing radially outside the outer blade surface 12A of the guide vane 12, or may be opened by an external input. Good. Further, the on-off valve 42 may be configured to be capable of adjusting the flow rate of the water to be passed.

  In the present embodiment as described above, when the operating state of the water turbine 1 at the time of pumping operation becomes the operating point at or near the backflow generation point, the on-off valve 42 of the flow rate adjusting mechanism 30 is opened to open the water supply hole. By supplying water from the outside 41 to the radially outer side of the outer diameter side wing surface 12A, it is possible to increase the flow rate of water flowing on the outer side of the outer diameter side wing surface 12A of the guide vane 12 in the radial direction. Thereby, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to the high head side or eliminated. In a normal operation state such as an operation in the operation range Bu shown in FIG. 3, by closing the on-off valve 42, it is possible to avoid an undesirable decrease in efficiency due to water supply.

  Also in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, also in the present embodiment, in the pumping operation, it is possible to partially move only the backflow generation point to the high head side or eliminate the backflow generation point while maintaining the guide vane 12 at the on-cam point, and thereby, The problem of the backflow generation point can be improved while suppressing a decrease in the operation efficiency.

  In the present embodiment, the water supply holes 41 are provided in both the upper cover 18U and the lower cover 18D, but a configuration in which the water supply holes 41 are provided in one of the upper cover 18U and the lower cover 18D is adopted. Is also good.

(Sixth embodiment)
Next, a sixth embodiment will be described. FIG. 12 is a view showing a guide vane and a flow rate adjusting mechanism of the Francis type pump-turbine according to the sixth embodiment, and FIG. (B) is a figure which shows the state after flow volume adjustment. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIG. 12, in the present embodiment, the flow rate adjusting mechanism 30 is configured such that at least one of the end face of the guide vane 12 on the upper cover 18U side and the end face of the guide vane 12 on the lower cover 18D side The guide vane 12 has a fillet portion 44 that protrudes toward at least one of the outside of the outer diameter side blade surface 12A and the outside of the inner diameter side blade surface 12B. As shown in FIGS. 12A and 12B, the fillet portion 44 has an extended position (FIG. 12A) projecting with respect to the end surface of the guide vane 12, and the guide vane 12 has a larger position than the extended position. It can be moved between a storage position (FIG. 12B) near the end face. Then, the flow rate adjusting mechanism 30 can selectively increase the flow rate of water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 by selectively switching between the overhang position and the storage position. Has become.

  In the present embodiment, when the operating state of the water turbine 1 at the time of pumping operation becomes a backflow occurrence point or an operating point in the vicinity thereof, the flow rate adjusting mechanism 30 moves the fillet portion 44 from the overhang position to the storage position. By doing so, the pressure loss with respect to the water passing through the gap between the end face of the guide vane 12 and the cover is reduced. Thereby, the flow rate of the water flowing radially outside the outer diameter side blade surface 12A of the guide vane 12 can be increased. As a result, as shown by the arrow in FIG. 3, the backflow occurrence point can be shifted to the high head side or eliminated.

  Further, in a normal operation state such as an operation in the operation range Bu shown in FIG. 3, by holding the fillet portion 44 at the extended position, the pressure loss in the gap is increased, thereby increasing the sealing effect. In addition, a reduction in efficiency due to water leakage from the gap can be suppressed.

  Also in the present embodiment, when increasing the flow rate of water as described above, it is not necessary to adjust the angle of the guide vane 12, and the guide vane 12 can be maintained at the on-cam point. Therefore, a decrease in the operating efficiency and the amount of pumped water during the pumping operation due to the opening degree of the guide vane 12 is suppressed.

  Therefore, also in the present embodiment, in the pumping operation, it is possible to partially move only the backflow generation point to the high head side or eliminate the backflow generation point while maintaining the guide vane 12 at the on-cam point, and thereby, The problem of the backflow generation point can be improved while suppressing a decrease in the operation efficiency.

(Seventh embodiment)
Next, a seventh embodiment will be described. FIG. 13A is a meridional sectional view of a Francis type pump turbine according to the seventh embodiment, and FIG. 13B is a diagram showing a guide vane and a lower cover of a Francis type pump turbine shown in FIG. FIG. 4 is a diagram viewed downward along a rotation axis. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  The flow rate adjusting mechanism 30 according to the present embodiment has a configuration similar to that of the first embodiment, and further includes a pressure gauge 46. The pressure gauge 46 is provided on each of the upper cover 18U and the lower cover 18D. More specifically, FIG. 13B shows a state in which the guide vane 12 is at the on-cam point corresponding to the operating point at which the operating range Bu has the highest head in the operation according to the performance curve Y in FIG. I have. As shown in the figure, when the guide vane 12 is at the above-mentioned on-cam point, the lower pressure gauge 46 is located radially outside the outer-side blade surface 12A of the guide vane 12. More specifically, the lower pressure gauge 46 is located near the outside of a portion near the runner 14 on the outer diameter side blade surface 12A. The upper pressure gauge 46 is configured similarly to the lower pressure gauge 46.

  Then, the flow rate adjusting mechanism 30 flows outside the radially outer wing surface 12A of the guide vane 12 in accordance with the pressure of the water flowing outside the radially outer wing surface 12A of the guide vane 12 detected by the pressure gauge 46. The flow rate of water is selectively increased. Specifically, the pressure gauge 46 is connected to a control device 48 that controls the operation of the flow adjustment mechanism 30. In the present embodiment, when the pressure gauge 46 detects a pressure that is equal to or lower than a predetermined pressure that is estimated to cause a backflow phenomenon in the pumping operation, the control device 48 controls the flow rate adjusting mechanism 30 The upper cover 18U and the lower cover 18D are separated from the guide vane 12.

  According to the present embodiment, even if the operation state is unexpectedly changed to the backflow generation point due to disturbance such as system disturbance, the sign of separation is detected by the pressure gauge 46, so that separation is performed. Can be suppressed. As a result, operation in an unstable state can be avoided. Note that the pressure gauge 46 and the control device 48 according to the present embodiment may be applied to the second to sixth embodiments.

(Eighth embodiment)
Next, an eighth embodiment will be described. FIG. 14 is a meridional sectional view of a Francis type pump-turbine according to the eighth embodiment. In the present embodiment, the same components as those of the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIG. 14, in the present embodiment, a pressure gauge 46 is provided on the outer diameter side blade surface 12A of the guide vane. The pressure gauge 46 according to the present embodiment may be applied in the second to sixth embodiments.

  Although the embodiments of the present invention have been described above, the above embodiments are presented as examples and are not intended to limit the scope of the invention. This new embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Francis type pump-turbine, 10 ... Casing, 12 ... Guide vane, 12A ... Outer diameter side wing surface, 12B ... Inner diameter side wing surface, 13 ... Stay vane, 14 ... Runner, 18U ... Upper cover, 18U1 ... Outer diameter side cover part, 18U2 ... inner diameter side cover part, 18D ... lower cover, 18D1 ... outer diameter side cover part, 18D2 ... inner diameter side cover part, 22 ... guide vane spindle, 30 ... flow rate adjustment mechanism, 31 ... actuator, 41 ... water supply hole, 41A ... Upstream flow path, 41B Downstream flow path, 42 On-off valve, 44 Fillet, 46 Pressure gauge, 48 Control device, C1 Runner rotation axis L1 Guide vane rotation axis

Claims (4)

A guide vane and a stay vane are arranged between the runner and the casing, and by rotating the runner, a hydraulic machine that pumps water from the runner side to the casing side via the guide vane and the stay vane,
It has a water supply hole opened on the outer diameter side wing surface of the guide vane, and by selectively supplying water from the water supply hole, selects a flow rate of water flowing radially outside the outer diameter side wing surface of the guide vane. Ru with a flow rate adjusting mechanism for incrementally, hydraulic machine. A guide vane and a stay vane are arranged between the runner and the casing, and by rotating the runner, a hydraulic machine that pumps water from the runner side to the casing side via the guide vane and the stay vane,
A water supply hole penetrating from the inner diameter side wing surface to the outer diameter side wing surface of the guide vane, and an on-off valve provided in the water supply hole, and by opening the on-off valve, the outer diameter side wing of the guide vane Ru with a flow rate adjusting mechanism for selectively increasing the flow rate of the water flowing through the radially outer surface, the hydraulic machine. A guide vane and a stay vane are disposed between the runner and the casing, and by rotating the runner, a hydraulic machine operating method for pumping water from the runner side to the casing side via the guide vane and the stay vane is provided. So,
A flow rate adjusting mechanism having a water supply hole that opens at the outer diameter side wing surface of the guide vane is used. It comprises a flow rate adjusting step of Ru selectively increasing the flow rate of the water, the hydraulic machine operating method. A guide vane and a stay vane are disposed between the runner and the casing, and by rotating the runner, a hydraulic machine operating method that pumps water from the runner side to the casing side via the guide vane and the stay vane. So,
A flow control mechanism having a water supply hole penetrating from the inner diameter side wing surface to the outer diameter side wing surface of the guide vane, and an on-off valve provided in the water supply hole is used. A method for operating a hydraulic machine, comprising: a flow rate adjusting step of selectively increasing a flow rate of water flowing radially outside a vane outer wing surface.

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