JP2020002785A - Bulb turbine - Google Patents

Abstract

To provide a bulb turbine capable of suppressing contact between a runner vane and a discharge ring.SOLUTION: A bulb turbine is equipped with a bulb including a generator; a casing which is provided on an outer periphery while keeping a predetermined gap from the bulb, and forms a channel between the outer periphery and the bulb; a runner coupled to a downstream side of the bulb; a discharge ring which surrounds an outer periphery of the runner; a fixing portion which fixes the bulb and the discharge ring through the channel; and a coupling portion provided between the casing and the discharge ring. The discharge ring is coupled to the casing through the coupling portion, thereby being configured to follow the bulb.SELECTED DRAWING: Figure 1

Description

  An embodiment of the present invention relates to a valve turbine.

  Valve turbines include axial flow turbines such as mixed flow turbines, Kaplan turbines, and valve turbines. For example, in the case of a valve turbine, a valve, which is a casing of a generator, is provided inside a casing, which is a flowing water channel. A runner is provided downstream of the valve, and the runner and the generator are connected via a rotating shaft.

  The valve is fixed to a foundation cast on the outer periphery of the casing via a stay vane. That is, one end of the stay vane is fixed to the outer peripheral surface of the valve, and the other end penetrates the inner peripheral surface of the casing, and is embedded and fixed in the foundation. Thereby, the valve is held inside the water channel via the stay vane.

  The outer periphery of the runner is surrounded by a discharge ring. A predetermined gap is provided between the outer peripheral surface of the runner and the inner peripheral surface of the discharge ring. The larger this gap is, the more the leakage flow not contributing to the rotational drive of the runner and the generator. Therefore, this gap is generally designed to be small.

JP-A-62-41972 Japanese Utility Model Publication No. 62-169266

  However, in the valve turbine, the valve may be displaced from the fixed position due to insufficient support rigidity of the valve, unevenness in the pressure distribution of flowing water, or hydraulic pulsation. When the valve is displaced, the generator housed in the valve and the runner connected to the generator are displaced following the valve, which may cause a contact accident between the runner and the discharge ring.

  Therefore, an object to be solved by the present invention is to provide a valve turbine that can suppress contact between the runner vane and the discharge ring.

  In order to solve the above-described problems, according to the valve turbine of the embodiment, a valve having a built-in generator and an outer periphery provided with a predetermined gap from the valve are provided, and a flow is provided between the outer periphery and the valve. A casing forming a path, a runner connected to the downstream side of the valve, a discharge ring surrounding an outer periphery of the runner, a fixing portion fixing the valve and the discharge ring via the flow path, and the casing And a connection part provided between the discharge ring and the discharge ring. The discharge ring is connected to the casing via the connection part, so that the discharge ring can follow the valve.

It is a schematic diagram of the valve turbine according to the first embodiment. It is a schematic diagram of a valve turbine according to a modification of the first embodiment. It is a schematic diagram of a valve turbine according to a second embodiment. It is sectional drawing which looked at the guide vane which concerns on 2nd embodiment from the AA direction. It is a sectional view of a guide vane concerning a modification of a second embodiment. It is a schematic diagram of a valve turbine according to a third embodiment. It is sectional drawing which looked at the guide vane which concerns on 3rd Embodiment from BB direction.

  First to third embodiments of the present invention will be described. In each embodiment, a discharge ring to be described later is fixed to the valve via the fixing portion, and moves following the displacement and vibration of the valve. Thereby, contact between the discharge ring and the runner vane can be suppressed. In each embodiment, there is a difference in the type of the fixing part and the fixing method. Hereinafter, each embodiment will be described in detail. In the following description, the upstream side during the operation of the turbine is simply referred to as the upstream side, and the downstream side during the operation of the turbine is simply referred to as the downstream side.

(First embodiment)
The valve turbine according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram of a valve turbine according to the first embodiment. The arrow drawn in FIG. 1 represents the flow direction of flowing water. The valve wheel 1 according to the present embodiment includes a casing 2, a valve 3, a first stay vane 4, a second stay vane 5 (fixed portion), a guide vane 6, a runner 7, a discharge ring 8, and a suction pipe. It comprises a tube 9 and flexible joints 10a and 10b. That is, the second stay vane 5 is provided as a fixing portion of the discharge ring 8.

  The casing 2 is a water channel for introducing flowing water from an upper pond (not shown), and is formed by, for example, an iron pipe. The casing 2 in the present embodiment refers to a portion of the flowing water channel upstream of the discharge ring 8 described later, and does not include a guide vane outer cylinder provided in a general water turbine. A foundation is cast on the outer peripheral side of the casing 2.

  The valve 3 is a housing that houses a generator (not shown), and is disposed inside the casing 2. Here, the arrangement inside the casing 2 means that at least the upstream end of the valve 3 is surrounded by the casing 2, and is not necessarily limited to the entire valve 3 being housed inside the casing 2. Not something.

  The first stay vane 4 is a fixed blade of the valve wheel 1. One end of the first stay vane 4 is fixed to the outer peripheral surface of the valve 3, and the other end penetrates the inner peripheral surface of the casing 2 and is fixed to the foundation. Thus, the valve 3 is connected to the casing 2 via the first stay vane 4. Here, the first stay vane 4 only needs to be able to hold the valve 3 on the inner peripheral surface of the casing 2, and does not need to be fixed to the extent that displacement and vibration of the valve are suppressed unlike the conventional stay vane.

  The second stay vane 5 is a fixed blade of the valve wheel 1 and a fixed portion for fixing the valve 3 to a discharge ring 8 described later. One end of the second stay vane 5 is fixed to the outer peripheral surface of the valve 3, and the other end is fixed to the inner peripheral surface of the discharge ring 8. Further, the second stay vane 5 may be designed to have a blade length and a thickness sufficient to fix the valve 3 and the discharge ring 8, for example, from 10% to half of the blade length and the thickness of the first stay vane 4. The design value is not limited to a specific value.

  The guide vane 6 is provided on the downstream side of the first stay vane 4 and the second stay vane 5 and on the upstream side of a runner vane 7 b described later, and the flow rate of flowing water from the casing 2 to the runner 7 by changing the opening degree. To adjust.

  The runner 7 has a runner boss 7a and a runner vane 7b. The runner boss 7a is connected to a generator (not shown) via a rotating main shaft AX, and a runner vane 7b is provided on an outer periphery thereof.

  The discharge ring 8 is a stationary part that does not rotate due to running water, and surrounds the outer periphery of the discharge ring 8 with a small space between the discharge ring 8 and the runner vane 7b. The discharge ring 8 in the present embodiment indicates a portion provided between the casing 2 and the suction pipe 9. In other words, the discharge ring 8 includes a guide vane outer cylinder and the like in addition to a discharge ring of a general valve turbine. However, the discharge ring 8 only needs to surround the outer periphery of the runner vane 7b and have a fixed portion that is fixed to the second stay vane 5 (fixed portion). Does not need to be included as a part. A space 11 is provided outside the outer peripheral surface of the discharge ring 8 in the circumferential direction so that the discharge ring 8 can be displaced. As the space 11, an existing space for installing a conventional discharge ring may be used, and it is not always necessary to provide a new space.

  The discharge ring 8 is connected to the casing 2 and the suction pipe 9 via flexible joints 10a and 10b described later, respectively, and is fixed to the valve 3 via the second stay vane 5 (fixing portion). That is, although the discharge ring 8 does not rotate depending on the rotational force received from the flowing water, it is fixed to the extent that it can move when it receives a force via the second stay vane 5 due to the displacement or vibration of the valve 3.

  The flexible joints 10a and 10b are connecting portions that connect the discharge ring 8 to the casing 2 and the suction pipe 9 to such an extent that the discharge ring 8 can move following the valve 3. In the present embodiment, both ends thereof are connected. It consists of bellows on the flange surface. Note that the flexible joints 10a and 10b in the present embodiment may be any configuration as long as the discharge ring can be connected to the valve so as to be able to follow the valve and can maintain water tightness on the inner peripheral side. Is also good. Further, in the present embodiment, the case where the discharge rings 8 are connected using the flexible joints 10a and 10b is illustrated, but only one side of the discharge ring 8 is connected using the flexible joints 10a or 10b. It may be configured.

That is, the flexible joint 10 a is coupled to the downstream end surface of the casing 2 and the upstream end surface of the discharge ring 8 at the flange surfaces provided at both ends thereof. Similarly, the flexible joint 10 b is connected to the downstream end surface of the discharge ring 8 and the upstream end surface of the suction pipe 9 at the flange surface thereof.

  Next, the operation of the present embodiment will be described. The running water supplied from the upper pond (not shown) is supplied to the runner 7 through the casing 2, the first stay vane 4, the second stay vane 5 (fixed portion), and the guide vane 6 in order, and the runner boss 7a and The runner vane 7b (that is, the runner 10) is rotated. The rotation of the runner boss 7a causes the generator to rotate with the runner boss 7a. The running water flowing out of the runner 7 is discharged to a lower pond (not shown) via the suction pipe 9.

  Generally, in such a valve turbine, a vortex tends to be generated during a partial load operation in which the flow rate is smaller than that in the constant load operation, and the vortex core of the vortex tends to be spiral as the flow rate of the flowing water is smaller. When a vortex is generated in which the vortex has a helical shape, a region having a relatively high water pressure and a region having a relatively low water pressure are generated in the rotation direction of the runner, and these regions periodically change according to the whirling of the vortex (water pressure pulsation) ).

  In a state where the hydraulic pulsation occurs, the valve 3 is displaced (vibrated) under the influence of the hydraulic pulsation. When the valve 3 is displaced, the runner 7 is displaced following the valve 3. At this time, since the discharge ring 8 is connected to the valve 3 via the second stay vane 5 (fixed portion), the discharge ring 8 is also displaced following the valve 3. Therefore, since both the runner 7 and the discharge ring 8 are displaced following the valve 3, even when the valve 3 is displaced, the gap between the runner vane 7b and the discharge ring 8 can be maintained, and their contact can be prevented.

  That is, in the present embodiment, the valve 3 and the discharge ring 3 are fixed via the second stay vane 5 (fixed portion), and the discharge ring 8 moves so as to follow the displacement of the valve 3. Generally, since the valve 3 and the runner 7 are connected via a generator (not shown) and the rotating main shaft AX, when the valve 3 moves, the runner 7 and the discharge ring 8 move similarly. Therefore, even when the valve 3 is displaced, the gap between the runner vane 7b of the runner 7 and the discharge ring 8 can be maintained, and the contact therebetween can be prevented.

  According to the above-described first embodiment, the valve 3 and the discharge ring 8 are fixed via the second stay vane 5 which is a fixing portion, and the discharge ring 8 moves according to the displacement of the valve 3. Thus, even when the valve 3 is displaced, the contact between the runner 7 and the discharge ring 8 can be prevented, and the gap between the runner 7 and the discharge ring 8 can be designed smaller. Further, since the contact between the runner 7 and the discharge ring 8 can be prevented, the first stay vane 4 only needs to have enough strength to hold the valve 3 on the inner peripheral surface of the casing 2. Length and thickness can be designed smaller than before. Therefore, the loss due to the drag of the first stay vane 4 and the like can be suppressed.

  In the present embodiment, the case where the second stay vane 5 (fixed portion) is installed upstream of the runner vane 7b and downstream of the first stay vane 4 has been described as an example. The position of the stay vane 5 is not limited as long as the valve 3 and the discharge ring 8 can be fixed.

  Further, as a modified example of the present embodiment, for example, the discharge ring 8 and the suction pipe 9 may have an integral structure. Further, as another modified example of the present embodiment, a displacement damping device 11 may be provided on the discharge ring 8 as shown in FIG. 2, for example. With such a configuration, in addition to the same effects as in the first embodiment, the displacement of the valve 3 can be suppressed more quickly via the discharge ring 8. Therefore, the first stay vane 4 can be designed to be smaller, and the flow loss occurring in the first stay vane 4 can be further suppressed.

(Second embodiment)
A runner vane and a valve turbine according to the second embodiment will be described with reference to FIGS. FIG. 3 is an enlarged view of the runner vane according to the second embodiment, and FIG. 4 is a cross-sectional view of the runner vane according to the second embodiment as viewed from the AA direction. Hereinafter, portions different from the first embodiment will be described, and other portions are the same as those in the first embodiment, and description thereof will be omitted. As shown in FIG. 3, the valve wheel 1 according to this embodiment includes a casing 2, a valve 3, a first stay vane 4, a runner 7, a discharge ring 8, a suction pipe 9, and flexible joints 10a and 10b. And a guide vane 16. In the present embodiment, a guide vane inner shaft 16 a of a guide vane 16 described below is provided as a fixing portion of the discharge ring 8.

  The guide vane 16 includes a guide vane inner shaft 16a and a guide vane outer shaft 16b in addition to the guide vane main body which is a wing, and is provided downstream of the first stay vane 4 and upstream of the runner vane 7b. The guide vane body adjusts the flow rate of the flowing water flowing from the casing 2 to the runner 7 by changing its opening.

  The guide vane inner shaft 16a is a fixed shaft of the guide vane 16 and a fixing portion for fixing the valve 3 to a discharge ring 8 described later. One end of the guide vane inner shaft 16 a is fixed to the outer peripheral surface of the valve 3, and the other end is fixed to the inner peripheral surface of the discharge ring 8. That is, the guide vane inner shaft 16a not only can withstand the rotating force from flowing water like the conventional guide vane shaft, but also has a strength enough to support the discharge ring 8 by fixing the valve 3 and the discharge ring 8. Have. The diameter and length of the guide vane inner shaft 16a may be designed to fix the valve 3 and the discharge ring 8, and the design value is not limited to a specific range. The installation position of the guide vane inner shaft 16a is not limited to the location shown in the drawing.

  The guide vane outer shaft 16b is a hollow rotary shaft surrounding the outer peripheral surface of the guide vane inner shaft 16a. The guide vane outer shaft 16b is formed integrally with the guide vane main body, and adjusts the opening degree of the guide vane main body of the guide vane 16 via the guide vane outer shaft 16b. In the present embodiment, a case where the inner peripheral surface of the guide vane outer shaft 16b is separated from the outer peripheral surface of the guide vane inner shaft 16a by a predetermined gap will be described as an example. It may be in contact with the outer peripheral surface of the inner shaft 16a so as to be able to rotate and slide.

  That is, as shown in FIG. 4, the guide vane 16 in the present embodiment has a guide vane outer shaft 16 b which is a hollow shaft as a guide vane shaft, and the hollow portion includes a fixing portion of the valve 3 and the discharge ring 8. A certain guide vane inner shaft 16a is provided. With such a configuration, the discharge ring 8 can be made to move following the displacement of the valve 3 while maintaining the function of adjusting the flow rate of the flowing water as the guide vane.

  According to the second embodiment described above, the same effect as the first embodiment can be obtained by providing the guide vane 16 with the guide vane inner shaft 16a which is a fixing portion of the valve 3 and the discharge ring 8. . In addition, by using the shaft of the guide vane 16 as a fixing portion, it is not necessary to provide a new fixing portion in the flow path, and it is possible to further suppress a loss such as a drag due to the provision of the fixing portion.

  Although the guide vane 16 in the present embodiment has been described by exemplifying a case in which the guide vane main body and the guide vane outer shaft 16b are integrally formed, the structure is provided via the guide vane outer shaft 16b. It is only necessary that the opening degree of the guide vane body of the guide vane 16 can be adjusted. For example, the guide vane outer shaft 16b may be fitted into a fitting portion provided on the guide vane main body, or, as shown in FIG. 5, an upstream side 18a of the guide vane having a semicircular concave portion 17a and a semicircular The guide vane 16 having the recess 17b may be joined to the downstream side 18b by welding or the like, and the guide vane inner shaft 16a may be surrounded by the recesses 17a and 17b.

  Further, as another modified example of the present embodiment, a hole constituting the guide vane outer shaft may be provided in the existing guide vane main body.

(Third embodiment)
A runner vane and a valve turbine according to the third embodiment will be described with reference to FIGS. FIG. 6 is an enlarged view of the runner vane according to the third embodiment, and FIG. 7 is a cross-sectional view of the runner vane according to the second embodiment as viewed from the BB direction. Hereinafter, portions different from the first and second embodiments will be described, and the other portions are the same as those in the first or second embodiment, and description thereof will be omitted here. As shown in FIG. 6, the valve wheel 1 according to this embodiment includes a casing 2, a valve 3, a first stay vane 4, a runner 7, a discharge ring 8, a suction pipe 9, and flexible joints 10a and 10b. And a guide vane 26. In the present embodiment, a fixing portion 26 a of a guide vane 26 described later is provided as a fixing portion of the discharge ring 8.

  The guide vane 26 includes a rotating portion 26b and a fixed portion 26a, and is provided downstream of the first stay vane 4 and upstream of the runner vane 7b.

  The fixed portion 26a is a fixed blade that is located downstream of the guide vane shaft of the guide vane 26, and is a fixed portion that fixes the valve 3 to a discharge ring 8 described later. The fixing portion 26 a has one end fixed to the outer peripheral surface of the valve 3 and the other end fixed to the inner peripheral surface of the discharge ring 8.

  The rotating portion 26b is a rotating blade constituting the downstream side of the guide vane 26 including the guide vane shaft, and adjusts the flow rate of the flowing water flowing from the casing 2 to the runner 7 by changing the opening of the guide vane blade.

  That is, as shown in FIG. 7, in the guide vane 26 in the present embodiment, only the rotating portion 26b rotates around the guide vane axis. By having such a structure, the discharge ring 8 can be moved following the displacement of the valve 3 while maintaining the function of adjusting the flow rate of the flowing water as the guide vane.

  According to the above-described third embodiment, the upstream side of the guide vane 26 is provided as the fixing portion 26a, and the valve 3 and the discharge ring 8 are fixed via the fixing portion 26a, whereby the first embodiment or the second embodiment is described. The same effect as in the second embodiment can be obtained.

  While some embodiments of the invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

1. 1. Valve turbine, Casing, 3. Valve, 4. 4. first stay vane; 5. second stay vane, Guide vanes, 7. Runner, 7a. Runner boss, 7b. 7. Lanna vane, 8. Discharge ring, Suction tubes, 10a, 10b. Flexible joint, 16. Guide vanes, 16a. Guide vane inner shaft, 16b. Guide vane outer shaft, 17a, 17b. Recess, 18a. Upstream of the guide vane, 18b. 25. Downstream of the guide vanes, 26. Guide vanes, 26a. Fixing part, 26b. Rotating part

Claims (6)

A valve with a built-in generator,
A casing provided on the outer periphery of the valve with a predetermined gap therebetween, and forming a flow path between the outer periphery and the valve;
A runner connected downstream of the valve;
A discharge ring surrounding the outer periphery of the runner,
A fixing portion for fixing the valve and the discharge ring via the flow path,
A connecting portion provided between the casing and the discharge ring,
With
The discharge wheel is connected to the casing via the connection portion so that the discharge ring can follow the valve. A valve with a built-in generator,
A casing provided on the outer periphery of the valve with a predetermined gap therebetween, and forming a flow path between the outer periphery and the valve;
A runner connected downstream of the valve;
A discharge ring connected to the casing and surrounding an outer periphery of the runner;
A suction pipe for discharging running water that has passed through the runner,
A fixing portion for fixing the valve and the discharge ring via the flow path,
A connecting portion provided between the casing and the suction pipe,
With
The valve wheel is configured such that the discharge ring is connected to the suction pipe via the connection portion so that the discharge ring can follow the valve.   The valve turbine according to claim 1, wherein the fixing portion is provided between the connection portion and the runner.   4. The valve wheel turbine according to claim 1, wherein the fixing portion is provided downstream of the guide vane. 5.   The valve wheel turbine according to any one of claims 1 to 3, wherein the fixed portion is provided upstream of the guide vane. The fixing portion is an inner shaft of the guide vane,
4. The guide vane according to claim 1, wherein the guide vane has an outer shaft rotatably provided on an outer periphery of the guide vane via a predetermined gap from the fixed portion and forming a rotation center of the guide vane. 5. Valve waterwheel.

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