JPH0426700Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Industrial application field The present invention relates to once-through water turbines. Specifically, the invention makes it possible to change the flow path area upstream of the runner depending on the flow rate, and prevents a decrease in efficiency regardless of changes in flow rate. This allows you to drive without causing any damage.

B. Summary of the invention The present invention relates to a once-through water turbine that can suppress a drop in efficiency even when the flow rate changes. is provided with a pair of guide vanes close to the runner so as to be able to open and close in the horizontal direction on the upstream side of the runner, and a guide vane operating mechanism that drives the guide vanes to open and close by applying an opening and closing force to the tips of these guide vanes. By opening and closing the guide vane according to changes in flow rate and changing the flow path area upstream of the runner,
This allows the energy of the water to effectively act on the runner regardless of changes in flow rate.

C. Conventional technology In once-through water turbines, such as cross-flow water turbines, in order to operate efficiently according to the amount of water, the guide vane on the upstream side of the runner is divided.
A system has been proposed in which when the flow rate decreases, water can be supplied only to a portion of the runner by operating guide vanes.

An example of a guide vane split type cross flow turbine as described above is shown in FIG. As shown in the figure,
In this cross-flow turbine, a runner 4 is horizontally and rotatably supported by its shaft (runner shaft) 5 in a casing 3 to which an inlet pipe 1 is connected to the upstream side and an outlet pipe 2 is connected to the downstream side. This runner 4
Guide vanes 6a and 6b divided into two on the upstream side of
The structure supports this. In the figure, 7 is a housing that covers between the casing 3 and the outlet pipe 2;
is a partition plate provided between two guide vanes 6a and 6b, and 9a and 9b are each guide vane 6a and 6b.
These are operating levers that operate the , and each is connected to an actuator.

In the cross-flow turbine having the above structure, efficient operation of the water turbine is possible by operating the two guide vanes 6a and 6b according to the flow rate. For example, when the flow rate decreases, one guide vane 6a or 6b is closed so that the water flow acts on a part of the runner 4.
The energy of the water acts effectively on the runner 4, thereby preventing a decrease in efficiency.

D. Problems that the invention aims to solve By the way, there are two design requirements for the runner, which is one of the constituent elements of a cross-flow turbine: runner diameter and runner length. You can't make it bigger.

Water turbines where the runner length cannot be increased as shown above,
In other words, in a water turbine with a short runner length, if split guide vanes are adopted as described above to improve efficiency when the flow rate is low, the split guide vanes will become extremely short, which will cause water leakage from the outer periphery of the runner side and water leakage from both sides of the waterway. A situation arises in which efficiency decreases due to turbulence in the flow.

The ratio of the runner outer diameter to the runner length is called the aspect ratio, and if this aspect ratio is less than 0.1, the efficiency will decrease by about 3%, so it is practically desirable to have an aspect ratio of 0.25 or more. Generally, in a split guide vane, the width is divided into 1:2 ratios, so if the overall aspect ratio is 0.75, the smaller aspect ratio will be 0.25, which is not preferable for efficiency.

The present invention was developed in view of the above-mentioned conventional technical situation, and its purpose is to prevent a decrease in efficiency even when the flow rate changes in a once-through water turbine without using split guide vanes. The goal is to allow you to drive without having to worry about it.

E. Means for Solving the Problems The configuration of the present invention to achieve the above object is that in a once-through water turbine in which the runners are installed perpendicularly to the water flow direction, a pair of guides whose tips are close to the runners are provided. Each rear end of the vane is rotatably supported around a support shaft on the upstream side of the runner, so that the guide vane can be opened and closed in the horizontal direction, and a link mechanism is connected to the tip of each guide vane. A guide vane operating mechanism is provided that drives the guide vane to open and close by applying an opening/closing force, and the guide vane operating mechanism can open and close the guide vane to change the flow path area on the upstream side of the runner. do.

F Effect In the above-mentioned once-through water turbine, the flow path area upstream of the runner can be changed by opening and closing the guide vane using the guide vane operating mechanism.Even when the flow rate changes, the area upstream of the runner can be changed by opening and closing the guide vane. By changing the side channel area, the water's energy (velocity energy, pressure energy, potential energy, etc.) can be effectively applied to the runner regardless of changes in flow rate, and a drop in the efficiency of the water turbine can be prevented. It is.

G. Embodiment Fig. 1 shows a cross-section along a substantially plane of a cross-flow turbine, which is an embodiment of a once-through water turbine according to the present invention, and Fig. 2 shows a perspective appearance of its guide vanes, etc. . The figure shows a perspective appearance of one guide vane, and FIGS. 4 and 5 show cross-sections of the cross-flow turbine according to the embodiment in different states along a plane.

The structure of this cross-flow water turbine other than the guide vane section is similar to the conventional one shown in FIG. In other words, a runner 4 is horizontally and rotatably supported by its runner shaft 5 at right angles to the water flow direction within a casing 3 to which an inlet pipe 1 is connected to the upstream side and an outlet pipe 2 is connected to the downstream side. There is. In addition, the casing 3 and the outlet pipe 2
The space between them is covered by a housing 7 (see FIG. 5).

A pair of guide vane support shafts 10 are provided nearer to the inlet pipe 1 side of the casing 3 and are opposed to each other in a direction parallel to the axial direction of the runner 4 and are oriented in the vertical direction.
a and 10b are rotatably provided as pivots. Each guide vane support shaft 10a, 10b includes
Guide vanes 11a and 11b whose tips extend close to the circumferential surface of the runner 4 and are curved along the shape of the runner 4 are attached. Guide vane upper plates 12a, 12b are attached to the upper edges of the guide vanes 11a, 11b, and are curved along the inner surface of the upper plate of the casing 3 and have the same curved shape as the casing upper plate.
Guide vane lower plates 13a and 13b are attached to the lower edge of b along the inner surface of the lower plate of the casing 3 and have the same shape as the casing lower plate. The guide vane upper plates 12a, 12b and the guide vane lower plates 13a, 13b have a rectangular shape when viewed from above, and the tips (downstream side) of each guide vane upper plate 12a, 12b and guide vane lower plate 13a, 13b
The tips of the guide vanes 11a and 11b are located on the inside, and the rear ends of the guide vanes 11a and 11b are located on the outside of the rear ends (upstream side) of each guide vane upper plate 12a and 12b and guide vane lower plate 13a and 13b, It is attached to guide vanes 11a and 11b. In other words, the guide vane upper plates 12a, 12
b. The guide vane lower plates 13a, 13b are arranged so that one diagonal line of the guide vanes 11a, 13b is along the upper or lower edge of the guide vanes 11a, 11b.
11b. In addition, the guide vane upper plates 12a and 12b, the guide vane lower plate 1
The tips of 3a and 13b are connected to the casing support shaft 10.
It is an arc centered on a and 10b. or,
The shapes of the upper and lower plates of the casing 3 are shaped to match the curved surfaces of the guide vane upper plates 12a, 12b and the guide vane lower plates 13a, 13b, which open and close around the guide vane support shafts 10a, 10b. There is. In addition, since the guide vanes 11a and 11b receive a large force in the direction of opening due to the water flow, reinforcing bones 14 are provided on the outer surfaces of the guide vanes 11a and 11b.
a, 14b are provided.

Pin seats 15a, 15b are provided on the outer surface of the tip side of each guide vane 11a, 11b, and pin seats 16a,
One end portions of intermediate links 17a and 17b are rotatably connected by 16b. On the other hand, guide vane operating shafts 18a and 18b are provided on both sides of the casing 3 to protrude from the upper plate of the casing.
Lever 19a, 19b is provided integrally with 8a, 18b, and the lever 19a, 19b and the other end of the intermediate link 17a, 17b are connected to pins 20a, 2
They are rotatably connected by 0b. The ends of the guide vane operating shafts 18a and 18b projecting upward from the casing are connected to actuators and the like that rotate them in opposite directions. Therefore, due to the operation of the actuator, etc.,
The guide vane operating shafts 18a and 18b are rotated in opposite directions, and accordingly, the lever 19
a, 19b, intermediate links 17a, 17b, etc., the guide vanes 11a, 11b are rotated in opposite directions, that is, opened and closed, about the guide vane support shafts 10a, 10b. In this way, in this embodiment, the pin seats 15a, 15b, the intermediate links 17a, 17b, the levers 19a, 19b,
The guide vane operating mechanism is constituted by the guide vane operating shafts 18a, 18b, actuator, etc. In the figure, arrow W indicates the flow of water, and arrows a and b indicate the opening and closing directions of guide vanes 11a and 11b.

In the above-described cross-flow turbine, when the flow rate of water supplied to the turbine changes, the guide vane operating mechanism opens and closes the guide vanes 11a and 11b to control the runner 4.
By changing the upstream passage area, the energy of water (velocity energy, pressure energy, potential energy, etc.) can effectively act on the runner 4. For example, when the flow rate decreases, the guide vanes 11a and 11b are closed and the guide vane 11
By narrowing the opening to the runner 4 formed by a and 11b, water can be applied to the runner 4 without impairing the flow rate, and a drop in efficiency is prevented. Further, since guide vane upper plates 12a, 12b and guide vane lower plates 13a, 13b are provided above and below the guide vanes 11a, 11b, the water guided by the guide vanes 11a, 11b flows through the guide vanes 11a, 11b. This prevents leakage to the outside, and this also helps prevent a decrease in efficiency. Furthermore, since the guide vane operating mechanism employs a structure in which an opening/closing force is applied to the tips of the guide vanes 11a and 11b, the guide vanes 11
Only a small amount of force is required to operate a and 11b.
Incidentally, since the force received by the guide vane operating shafts 18a and 18b is relatively small, it becomes easy to prevent water from leaking through the casing penetrating portion, and the reliability of the shaft penetrating portion also increases.

FIGS. 3 and 4 show a substantially planar cross-section and a vertical cross-section of a cross-flow turbine according to another embodiment of the present invention. Note that the cross section taken along the - arrow in FIG. 4 corresponds to FIG. 3.

In this embodiment, the direction of the water flow is gentle in order to prevent a drop in efficiency due to flow and separation caused by a sudden change in the direction of the water flow, and to prevent corrosion of components due to cavitation or impingement attack. The present invention is applied to a cross-flow water turbine that is designed to change. In other words, in this embodiment, the water channel area is made to change gradually from the base end side to the distal end side of the guide vanes 11a, 11b. The waterway area at points A, B, and C in the figure is h ₁ ×
By setting l ₁ , h ₂ ×l ₂ , and h ₃ ×l ₃ , these are made to change (shrink) equally. As shown in the figure, the specific shape is S-shaped when viewed from above. In the figure, the heights h ₁ , h ₂ , and h ₃ of the waterway are set at right angles to the streamlines.

The other configurations of this embodiment are the same as those of the previous embodiment, so their explanation will be omitted.
In addition, in FIG. 4, 3a is the casing upper plate, and 3b is the casing lower plate.

Also, according to this embodiment, the guide vane operating mechanism opens and closes the guide vanes 11a and 11b according to the flow rate, as in the previous embodiment, to change the flow path area, thereby achieving an efficient water turbine. operation, as well as sudden changes in flow (direction, flow velocity)
This improves efficiency and prevents corrosion of components due to cavitation, impingement attack, etc.

The guide vane operating mechanism according to the present invention is not limited to one using a link mechanism as in the above embodiment, and various other mechanisms can be adopted.

H. Effects of the invention According to the once-through water turbine according to the invention, the flow path area on the upstream side of the runner can be changed according to changes in water volume, so efficient operation is possible over a wide range of water volume. Furthermore, since there is no guide vane that would create resistance in the middle of the waterway, there is no turbulence in the water, and the overall efficiency can be improved. Furthermore, since force is applied to the tip of the guide vane to open and close the guide vane, only a small amount of force is required to operate the guide vane, thereby simplifying and downsizing the structure of the guide vane operating mechanism. This makes it possible to downsize the water turbine itself.
In addition, the rigidity of the guide vane operating mechanism is increased and the support shaft of the guide vane can be made thinner, so the overall degree of freedom is increased and an inexpensive and practical water turbine can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a part of a cross-flow water turbine according to an embodiment of the present invention taken along a substantially plane surface, FIG. 2 is a perspective view of guide vanes, etc., and FIG. 3 is a cross-flow water turbine according to another embodiment of the present invention. A cross-sectional view along a partial plane of
FIG. 4 is a longitudinal cross-sectional view of the cross-flow water turbine shown in FIG. 3, and its cross-section in the direction of the - arrow corresponds to FIG.
FIG. 5 is a partially broken perspective view showing the inside of a conventional cross-flow water turbine. In the drawing, 1 is an inlet pipe, 2 is an outlet pipe, 3 is a casing, 4 is a runner, 10a, 10b are guide vane support shafts, 11a, 11b are guide vanes, 14
a, 14b are reinforcing bones, 17a, 17b are intermediate links, 18a, 18b are guide vane operating shafts, 19
a and 19b are levers.

Claims (1)

[Scope of utility model registration request] In a once-through water turbine in which a runner is provided perpendicular to the water flow direction, each rear end portion of a pair of guide vanes whose tips are close to the runner can be rotated about a support shaft on the upstream side of the runner. The guide vane is supported so that the guide vane can be opened and closed in the horizontal direction, and is provided with a guide vane operating mechanism that applies an opening and closing force to the tips of the guide vanes via a link mechanism to drive the guide vanes to open and close. Once-through water turbine.