JP2016031049A - Pump reversing water wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump reversing water wheel having a structure capable of adjusting the performance to enhance the turbine efficiency while suppressing a cost increase.SOLUTION: A pump reversing water wheel comprises: a runner 12 having a main plate 30 and a plurality of blades 14; and a casing for housing the runner 12 therein, and is enabled to run in both a withdrawal and an electric power generation by switching the rotation direction of the runner 12. The flow passage area of an introduction passage 28 in the water wheel operation of the runner 12 is set by the head drop and the flow rate at a water wheel running time.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a hydroelectric power generation pump reversing water turbine that uses a head of water in a dam, a water channel, a water purification plant, a sewage treatment plant, a river or the like.

  Conventionally, hydropower turbines have been optimally designed according to the water drop and flow rate at the installation site. However, it is expensive because it has a special structure and is designed according to the installation location each time.

In order to reduce the cost, there is generally a method called “pump reverse turbine” that uses a pump to generate power by reversing the water flow.
In general, a pump used for a pump reversing water turbine has an impeller fixed on a rotating shaft that rotates as a motor is driven (an impeller. In a water turbine, an impeller is referred to as a “runner”) rotatably disposed inside a casing. By rotating the impeller by a driving source such as an electric motor, the liquid sucked from the axial direction of the casing is boosted by the rotation of the impeller and discharged to the outside of the casing.

  In addition to being used as a pump, this type of pump may be used as a pump reversing turbine that converts a liquid flow into power as needed. For example, the pump reversing water turbine is operated as a pump when water is pumped into a water storage tank upstream of a river, and is operated as a water wheel when energy used for flowing down the pumped water is taken out as electric power.

  In the pump reversing turbine of Patent Document 1, in order to provide a pump reversing turbine that can increase the turbine efficiency with a simple configuration without causing an increase in product cost, the impeller is changed, and the radially outer side of each blade is changed. Is formed in a curved surface shape with a radius of curvature gradually decreasing toward the tip side.

Although patent document 2 is not a pump reverse rotation turbine, the turbine performance is adjusted using another part called an adjustment liner.
Patent Document 3 discloses a pump that is not a pump reversing water turbine, and is located between the blades adjacent to each other between the blades adjacent to each other to adjust the performance at a low cost, from one blade to the other blade. Disclosed is a partition blade extending toward the surface.

  In Patent Document 4, in a pump that is not a pump reversing turbine, in order to adjust its performance at low cost, a guide plate arranged concentrically with the impeller is placed in the casing, and the guide plate is arranged between the impeller side and the casing side. Disclosed is performance adjustment by having a plurality of passages penetrating and one passage in the plurality of passages communicating with a discharge port.

JP 2012-184699 A JP 2008-248762 A JP 2007-51592 A JP 2012-82778 A

The advantage of the pump reversing turbine is that it can be used for both pump and turbine applications, so that pumping can be performed during pump operation, and the water flow can be reversed to generate turbine power.
However, a pump reversing turbine is not within the performance line because the relationship between the head and flow rate (called the “performance line”) that gives the highest efficiency is uniquely determined by the size of the opening area of the flow path inside each pump. At the operating point under the above conditions (the relationship between the head and the flow rate is out of the performance line), the power generation efficiency is poor.

  As a countermeasure, it is sufficient to produce a pump reversing turbine of a size that provides the maximum efficiency in terms of the head and flow rate (operating point) where the pump reversing turbine is used, but this method has the following disadvantages.

If the optimum design is carried out each time according to the drop and flow rate of the place where it is used, the existing pump cannot be used, resulting in high costs.
There is a method to increase the number of existing pumps, but the number of necessary pump-making working molds also increases, and the management cost increases, so the cost for one unit also increases.

  There is also a method of remodeling to a structure in which a movable guide vane is provided on the outer periphery of the pump impeller (water flow inlet side) during reverse water turbine operation so as to correspond to the drop and flow rate at the place of use. For example, conventional methods for exclusive use of water turbines such as cross-flow turbines and Francis turbines adopt this method and cope with performance changes with movable guide vanes. However, since the structure becomes complicated and the cost is increased, the cost merit of the pump reverse turbine is lost.

  Then, an object of this invention is to provide the pump reverse rotation water turbine which has a structure which can adjust a performance so that a turbine efficiency may be improved, suppressing a cost increase.

  In order to achieve the above object, in the present invention, a runner having a main plate and a plurality of blades, and a casing for accommodating the runner therein, both modes of pumping and power generation by switching the rotation direction of the runner. In the pump reverse rotation turbine that can be operated in step 1, the flow passage area of the introduction path on the suction side of the runner during the turbine operation is set by the drop and the flow rate during the turbine operation.

The flow path area of the introduction path is set, for example, by the area of the opening that is the start part of the introduction path.
At this time, it is preferable to set the flow passage area of the opening on the suction side of the runner when the water turbine is operating by changing the blade height of the runner when the water turbine is operating.

  In addition, the intake path on the suction side of the runner during the water turbine operation is constituted by the main plate, the blades, and a side plate or casing portion facing the blades, and the blade height on the suction side of the runner during the water turbine operation is The side plate or the casing portion can be adjusted to the shape corresponding to the processing amount by adjusting the processing amount of the outer peripheral end of the blade.

The runner is an open impeller.
A pump reversing turbine comprising a main plate, a runner having a plurality of blades, and a casing for accommodating the runner therein, and capable of operating in both pumping and power generation modes by switching the rotation direction of the runner. In the method, it is preferable that the flow path area of the introduction path on the suction side of the runner during the water turbine operation is manufactured to a size set by a drop and a flow rate during the water turbine operation.

According to the present invention, in a pump reversing turbine having an open impeller, modification for performance adjustment in which the maximum efficiency of the turbine is adapted to various operating points (head and flow rate of the installation location) determined by the installation location. Can be realized at low cost. This is because the height of the blade on the inlet side of the blade as a water wheel can be changed by machining and the shape can be changed only by changing the shape of one component (a casing portion or a side plate facing the blade).

  For example, a pump having the highest blade height than the required blade height is selected from a plurality of standard size pumps in advance, and a pump having the blade height larger than the required blade height is selected. The height of the blade can be adjusted by cutting, and the performance can be adjusted so that the maximum efficiency of the turbine is obtained at the operating point.

  The pump reversing turbine equipped with an open impeller has no side plate, so it has the advantage of being able to suppress clogging of dust and easy to process. By changing only the blade height on the outer periphery of the runner, The performance can be adjusted at low cost so that the highest efficiency can be obtained at the operating point of the head and flow rate.

  The change in the height of the blade on the outer periphery of the runner uses the characteristics of the open impeller shape that does not have a side plate, and when the runner is manufactured, the open side end of the blade (the side plate (or casing part) facing the blade) Because it can be handled only by changing the processing amount of the end part) and changing the shape of the fixed part (side plate or casing part) corresponding to the processing amount, without significantly increasing the cost, Performance adjustment can be performed.

  When machining is performed to change the height of the blade on the outer periphery of the runner, the vane on the outer periphery of the runner and the flow path of the stationary casing during the pump operation (in the case of a spiral pump, the volute passage that surrounds the outer periphery of the impeller) A large step is formed between the flow path and the flow during pump operation (flow in the direction opposite to that during water turbine operation), and the flow path rapidly expands, resulting in flow loss and a significant decrease in pump operation efficiency. is expected. However, since the flow at the time of the water turbine operation is reduced at the step portion, the influence on the water turbine operation efficiency is small.

It is sectional drawing which cut | disconnected the whole pump reverse rotation turbine 10 by the perpendicular direction. FIG. 2A is a cross-sectional view of one blade 14 projected in the circumferential direction. 2B corresponds to the AA cross section of FIG. FIG. 3 shows the shape of the side plate 24, and FIG. 3A shows a CC cross section of FIG. 3B. It is a graph which shows an example of a performance line notionally. FIG. 5 is an enlarged view of the side plate 24 portion of FIG. It is a figure explaining the feature of an open type impeller and a closed type impeller. It is a figure explaining the feature of "both suction impeller" and "single suction impeller".

  Embodiments of a spiral pump turbine according to the present invention will now be described in detail with reference to the accompanying drawings. 1 to 3 are diagrams showing a schematic configuration of a pump reversing turbine 10 according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of the entire pump reverse turbine 10 cut in the vertical direction. FIG. 2A is a cross-sectional view of one blade 14 projected in the circumferential direction. FIG. 2B shows the runner 12 corresponding to the AA cross section of FIG. FIG. 3 shows the shape of the side plate 24, and FIG. 3A shows a CC cross section of FIG. 3B.

In this embodiment, the pump reversing turbine 10 is a centrifugal pump 10 and has an open-type impeller (runner) 12 having a plurality of blades 14 extending toward an outer peripheral portion, and a first casing that accommodates the runner 12 therein. 16. The runner 12 has a rotating shaft 1
The rotary shaft 18 and the runner 12 are rotatably supported on the axial center portion of the first casing 16. The rotating shaft 18 is connected to a generator motor (not shown) having both functions of a generator and a motor. The bearing portion of the pump reverse turbine 10 is accommodated in a bearing casing 19.

  The runner 12 includes a disk-shaped main plate 30 and a plurality of blades 14 connected to the rotary shaft 18. A portion near the axis of the main plate is provided with a boss portion 20, and the boss portion 20 is provided with a curved guide surface 20 a that protrudes while being curved radially outward from the shaft.

   A side plate 24 is installed on the side facing the blades 14. As shown in FIG. 3, the side plate 24 is open at the center so that the introduced liquid flows along the axial direction, and is an outlet 26 in the axial direction of the runner 12. A second casing 34 is provided at the outlet 26 of the side plate 24.

  As shown in FIG. 2B, the gap between adjacent blades 14 is an introduction path 28 into which liquid (water) is introduced from the radially outer peripheral side of the runner 12, and the introduction path 28 includes the main plate 30, the blades 14, and , And a side plate 24 on the open side of the blade 14 (the side having the axial outlet 26 is generally referred to as “open side”).

  Note that a notch 32 may be provided in a part of the outer peripheral portion of the main plate 30 as shown in FIG. 2B. The purpose of providing the notch 32 is to allow the dust to be removed from the notch 32 when the dust is caught on the back side of the main plate 30.

  Each blade 14 disposed on the main plate 30 extends from the boss portion 20 in an arc shape whose diameter changes. Therefore, when the impeller (runner) 12 rotates in the P direction during the pump operation, each blade 14 turns around the rotation center and is introduced in the axial direction from the opening of the second casing 34 (the outlet 26 during the water turbine operation). The discharged liquid is discharged radially outward by centrifugal force.

  During the water turbine operation, each blade 14 is rotated in the W direction opposite to that during the pump operation by the liquid introduced from the radially outer side of the runner 12 via the first casing 16, and the liquid is discharged from the outlet 26 in the axial direction. . Thus, during pump operation, the liquid sucked from the axial direction by the rotation of the impeller (runner) is discharged to the outer peripheral side of the impeller (runner), and during runner operation, the runner is rotated by the liquid introduced from the outer peripheral side of the runner. .

  As shown in FIG. 1, the first casing 16 includes a volute-shaped passage 36 that surrounds the outer peripheral side of the runner 12, and a passage 38 that extends tangentially from the passage 36. 12, the end of the passage 38 is connected to an external pipe (not shown) on the discharge side during pump operation. In addition, a passage communicating with the axial outlet 26 in the center of the runner 12 is provided in the center of the second casing 34, and the passage is connected to an external pipe (not shown) that serves as a suction side during pump operation.

  The passage 36 is joined to the passage 38, and the inner diameter of the passage 36 is not constant, the inner diameter of the region to which the passage 38 is connected is the largest, and the inner diameter increases from the region along the periphery of the impeller 12. It has a smaller volute shape.

In the case where the pump reverse turbine 10 configured as described above is operated as a pump, the impeller (runner) 12 is driven to rotate in the direction P in FIG. 2B by the power of the generator motor. Thus, when the impeller (runner) 12 rotates, the liquid sucked up from the outlet 26 by the rotation of the blades 14 on the impeller (runner) 12 is discharged to the passage 38 via the passage 36.

  On the other hand, when this pump reverse rotation turbine 10 is operated as a turbine, the liquid introduced into the passage 38 is caused to flow into the outer peripheral side (introduction passage 28) of the runner 12 through the passage 36. Thus, when the liquid swirls and flows into the runner 12 from the outer peripheral side, the liquid presses each blade 14 on the runner 12 in the W direction, and from the radially outer side to the inner side along the outer surface shape of each blade 14. Inflow. At this time, the liquid flowing into the center side of the runner 12 is discharged to the outlet 26, and the runner 12 rotates in the W direction by the pressing force acting on each blade 14. As a result, the generator motor is driven through the rotary shaft 18 and generates electric power by the driving force.

  By the way, the relationship between the head and the flow rate (the `` performance line '') that gives the highest efficiency as a turbine is uniquely determined by the shape of the runner and casing, so the power generation efficiency at operating points outside the performance line There is a problem that is bad. An example of the performance line is conceptually shown in FIG.

  The horizontal axis of FIG. 4 indicates the flow rate, the vertical axis indicates the drop, and the curves S1 to S6 indicate the performance line of the pump reverse turbine 10 when the pump size is S1 to S6. As for the size of the pump, S1 is the smallest, S6 is the largest, and S1 <S2 <S3 <S4 <S5 <S6.

The operation point M1 will be described as an example. When considering operation of a water turbine with M1 point having a head of 1.5 meters and a flow rate of 0.25 m ³ / s as an installation location, the pump reverse turbine of S6 is selected. In this case, the drop is 1.5 meters and 2 kW of power generation can be expected, but the pump reverse turbine S6 can use only a drop of 0.8 meters (M2 points) due to the performance of the turbine, and can generate only 1 kW.

  Therefore, in the present invention, as shown in FIG. 2A, the height (runner inlet width) 42 a, 42 b, 42 c of the blade 14 on the radially outer peripheral side of the runner 12 is set to a drop and a flow rate during water turbine operation. Thus, for example, one of 57 mm, 43 mm, and 29 mm is set. The heights 42a, 42b, and 42c shown in FIG. 2A are 57 mm, 43 mm, and 29 mm, respectively. The area of the opening 45 of the introduction path 28 is the product of the blade heights 42 a, 42 b, 42 c in the opening 45 and the width 46 in the opening 45 of the flow path formed by the adjacent blades 14.

  When the height is changed, the amount of change in the opening area is 43 ÷ 57 = 0.754 when the height is 57 mm, and 43 ÷ 57 = 0.754 when the height is 43 mm, and 29 ÷ 57 = 0. 508, and the opening area of the flow path decreases by 25% and 50%, respectively. The set amount of the opening area of the flow path corresponding to the performance adjustment amount is determined by changing the height of the blade 14 in the rotation axis direction and performing a turbine performance test.

  The external shape of the open side end face of the blade at that time is processed as external lines 40a, 40b, and 40c. Processing such as cutting is performed so that the processing amount is 43 mm or 29 mm with reference to the time of 57 mm. The outlines 40b and 40c are obtained by translating the outline 40a. The opening area for the outer shape line 40a corresponds to S6 in FIG. 4, and the opening area for the outer shape line 40b corresponds to S6a in FIG.

At the same time as adjusting the open side end face of the blade 14 as the outer shape lines 40a, 40b, 40c, the side plate 24 has a shape corresponding to the processing amount (outer shape lines 40a, 40b, 40c) of the open side end surface of the blade 14. To do. This will be described with reference to FIG. FIG. 5 is an enlarged view of the side plate 24 portion of FIG. The side plate 24 shown by a solid line corresponds to the outline 40a in FIG. 2, and the side plate 24a shown by a hatched line corresponds to the outline 40b in FIG. Accordingly, the length 44a is 57 mm, and the length 44b is 43 mm. The side plate 24 corresponding to the outline 40c is not shown. The side plate 24a is generally made of metal and may be manufactured in advance, or the end of the outlet side 26 may be processed.

  In the present invention, processing or modification is performed like the side plate 24 or the side plate 24a, but the shape and size of each part of the pump reverse rotation turbine 10 other than the blade 14 and the side plate 24 are not changed. By changing only the blade and the side plate, it is possible to cope with the drop and flow rate at various installation locations.

  In the method of manufacturing a pump reverse turbine according to the present invention, as described above, the height of the blade 14 on the outer peripheral side of the runner 12 is processed to an optimum value so that a head and a flow rate can be effectively used during operation of the turbine. To do.

  As described above, in the present invention, the height of the blade is adjusted by the processing amount of the open side end portion of the blade, and the side plate has a shape corresponding to the processing amount. That is, the maximum efficiency can be obtained at various operating points by changing the processing amount of the hatched portion in FIGS.

  In the present embodiment, the side plate 24 and the second casing 34 are separate members, but the side plate 24 and the second casing 34 may be integrated into a single member. In this case, the side plates 24 and 24a shown in FIG. 5 correspond to the casing part, and the casing part has a shape that matches the outlines 40a, 40b, and 40c.

  Further, in this embodiment, an open type impeller is employed, but the open type impeller is an impeller having only a main plate (shroud) 30 as shown in FIG. 6B. An impeller having a main plate and a side plate 44 is referred to as a closed type impeller and is shown in FIG. 6A. In the case of a closed type impeller, there is a side plate at the impeller axial outlet (discharge side during water turbine operation), so when changing the impeller inlet width by machining, it is necessary to change the shape including the side plate during manufacturing Therefore, it is not easy and increases the cost.

  The pump reverse turbine of the above embodiment is of a volute casing type, but the present invention can also be applied to a diffuser pump provided with a diffuser on the casing side in the outer peripheral direction of the impeller.

  The present embodiment is a centrifugal pump, but the present invention is an axial flow type pump turbine in which the flow passing through the impeller is in the same direction as the impeller shaft, and the flow passing through the impeller is oblique to the impeller shaft. It can also be applied to a mixed flow pump turbine. By applying the open type impeller structure of the present invention to these pumps, it is possible to cope with the drop and flow rate of various installation locations by changing only the blades and the side plates.

  In this embodiment, the suction type is called “single suction”. As shown in FIG. 7B, “single suction” has an outlet 26 (discharge port during water turbine operation) in the impeller axial direction, and discharges liquid in the impeller axial direction during water turbine operation. “Both suction”, as shown in FIG. 7A, has outlets 26a (discharge ports during water turbine operation) on both sides in the impeller axial direction, and discharges liquid from both sides in the impeller axial direction during water turbine operation. It is. The present invention can be applied to both “double suction” and “single suction” as long as it is an open impeller type.

In the present invention, the height of the blades on the outer peripheral side of the runner is set by the drop and flow rate during the water turbine operation, but the opening of the introduction path on the outer periphery side of the runner of the pump reverse rotation water turbine (the suction side during the water turbine operation) You may set the area of a part so that the maximum efficiency as a turbine may be acquired with respect to the head and the flow volume of the installation place of a pump reverse rotation turbine. As a method of changing the area of the opening, either or both of “the height of the impeller (blade)” and “the width of the flow path between adjacent blades (the space between the blades or the gap between the blades)” Can be changed.

  Moreover, when adjusting the height of the blade | wing on the outer peripheral side of a runner, in the Example of FIG. 1, the edge part of the open side of the blade | wing on the inlet side of the blade | wing as a water wheel is changed by a process, and side plate 24 However, apart from this, the base plate 22 side on the inlet side of the blade as a water wheel is manufactured thicker, the thickness is changed by processing, and the structure corresponding to the adjustment of the height of the blade It is good. Moreover, it is good also as a structure corresponding to adjustment of the height of a blade | wing by combining the shape change of the side plate 24 and the thickness change of the baseplate 22. FIG.

  In the above description, the case of water has been described as the liquid. However, the present invention can be applied to a liquid other than water as long as it is a liquid.

Claims (6)

A runner with a main plate and a plurality of blades;
A casing that houses the runner therein,
In the pump reverse rotation turbine that can be operated in both pumping and power generation modes by switching the rotation direction of the runner,
A reverse pump turbine according to claim 1, characterized in that the flow passage area of the introduction path on the suction side of the runner during the water turbine operation is set by a drop and a flow rate during the water turbine operation. In the pump reverse turbine according to claim 1,
A reverse pump turbine according to claim 1, wherein the flow passage area of the introduction path on the suction side when the runner is in operation is set by changing the blade height on the suction side when the runner is in operation. In the pump reverse turbine according to claim 1 or 2,
The intake path on the suction side of the runner during the water turbine operation is constituted by the main plate, the blade, and a side plate or a casing portion facing the blade,
The blade height on the suction side during the water turbine operation of the runner is adjusted by the processing amount of the outer peripheral end of the blade,
The side plate or the casing portion has a shape corresponding to the machining amount, and the pump reverse rotation turbine is characterized in that The pump reverse turbine according to claim 1 or 2,
The runner is an open type impeller. A runner having a main plate and a plurality of blades, and a casing for accommodating the runner therein,
In the manufacturing method of the pump reverse rotation water turbine that can be operated in both pumping and power generation modes by switching the rotation direction of the runner,
A method of manufacturing a pump reversing turbine, characterized in that the flow passage area of the intake path on the suction side of the runner is operated to a size set by a drop and a flow rate during the operation of the turbine. In the manufacturing method of the pump reverse rotation water turbine according to claim 5,
A pump reversing turbine characterized in that the flow passage area of the introduction path on the suction side of the runner during the water turbine operation is set to a set size by changing the blade height on the suction side of the runner during the water turbine operation. Manufacturing method.

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