JPS6311337Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the guide vane of a cross-flow water turbine so that the angle of water flowing into the runner is uniform.

As shown in FIG. 1, which shows a typical structure of a cross-flow water turbine, a runner 2 in which curved plate-shaped runner vanes 1 are arranged in a cylindrical shape is housed in a casing 3, and its rotating shaft 4 is connected to the casing. An inlet pipe 5 is connected to the upstream side of the casing 3, a water discharge pipe 6 is connected to the downstream side of the casing 3, and a cross-sectional blade is connected to the upstream side of the runner 2 to guide water and adjust the amount of water. A shaped guide vane 7 is provided, and the flow of water flowing in from the inlet pipe 5 is adjusted by the guide vane 7, and guided by both sides of the guide vane 7, entering the inside of the runner 2 from diagonally above and flowing diagonally downward. Rotate runner 2 with .

However, in a cross-flow turbine, there is only one guide vane 7 that guides water, and the water enters from a part of the outer periphery of the runner 2. Unlike the Kaplan turbine, it has the advantage of an extremely simple structure, but as shown in an enlarged view in FIG. The inflow angle α _A of water B flowing on the outside (upper surface) into the runner 2 is different from the inflow angle α _B of water B flowing into the runner 2, and the flowing water collides with the runner vane 1, resulting in a decrease in the efficiency of the cross-flow turbine.

That is, since water A flowing inside the guide vane 7 flows inside the lower surface of the guide vane 7, its inflow angle α _A (the tangential line L of the runner 2 at that point)
The angle α l of the extension line l of the inner wing surface of the guide vane 7 (the angle it forms with the tangential line L) is smaller than the angle α _l (the angle formed with the tangential line L). On the other hand, the water B flowing on the outside of the guide vane 7 is larger than the designed inflow angle (not shown) due to the need to increase the thickness in view of the strength required of the guide vane.

Therefore, the shape of the inner tip of the guide vane 7 needs to be such that the inflow angle is large, while the outer side needs to have a small inflow angle, which are contradictory requirements.

The object of the present invention is to provide a guide vane for a cross-flow turbine that satisfies such requirements and can improve the efficiency of the cross-flow turbine. The configuration of the present invention that achieves this objective is such that the downstream end of the guide vane, which is provided upstream of the runner housed in the casing and has an airfoil-shaped cross-section and which guides water to the runner and adjusts the amount of water, has the inner side of the downstream end facing outward. It is characterized in that it is formed into a plate shape that approximates the shape, and that reinforcing ribs are provided inside the tip portion along the water flow direction.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

The requirements for the shape based on the inflow angle of the water guided by the guide vane are that the inflow angle of the water flowing inside the tip of the guide vane should be large, and the inflow angle should be small on the outside.
Therefore, in the guide vane of the present invention, as shown in the perspective appearance in Fig. 3, the inner side of the downstream tip 7a of the guide vane 7 is shaved to make it thin so that it forms a plate shape with the outer wing shape. .

By carving the inner side into a plate shape in this way, the inflow angle of the water flowing on the inside can be increased while maintaining the inflow angle of the water flowing on the outside, and the difference between the two inflow angles can be extremely reduced. Therefore, after making the inflow angle smaller than before so that the outer side of the tip 7a of the guide vane 7 has a shape that provides an optimal inflow angle, the inner side of the downstream tip is shaved into a plate shape that approximates this outer shape. If the guide vane 7 is narrow,
It is possible to obtain an optimum inflow angle without any variation in the inflow angle. On the other hand, the tip 7
Since a is formed into a plate shape, the strength is reduced,
When the guide vane 7 is fully closed as shown in Fig. 4, there is a risk of deformation or damage due to water pressure, so a reinforcing rib 8 is installed inside the tip 7a of the guide vane 7 along the flow direction for reinforcement. Attach by welding, etc. at three locations: at both ends in the width direction and at the center.
By providing the reinforcing rib 8 inside the tip portion 7a in this way, even when the guide vane 7 is in the fully closed state, it does not get in the way and there is no problem.

By making the downstream tip 7a of the guide vane 7 plate-shaped and providing the reinforcing ribs 8 on the inside, the inflow angle of the water guided by the guide vane 7 can be made uniform, and the strength and total weight can be improved. There is no problem in keeping it in the closed state. In addition, the water entering the runner 2 includes water C and D that flow while being guided by the upper water guide 3a and the side water guide 3b of the casing 3.
Only the surfaces of these water guides 3a and 3b have a water guiding function, and the shape can be easily changed to optimize the inflow angle. Therefore, the inflow angle of water entering the runner 2 can be made uniform. can.

As described above in detail with the embodiments, according to the present invention, the inflow angle of water flowing into the runner can be made uniform, and the efficiency of the cross-flow water turbine can be improved.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a typical structure of a cross-flow turbine, Figure 2 is an explanatory diagram illustrating the angle of inflow into the runner by a guide vane, and Figure 3 is an implementation of the guide vane of the cross-flow turbine of the present invention. The external perspective view according to the example, and FIG. 4 is a cross-sectional view of the cross-flow water turbine. In the drawing, 1 is a runner vane, 2 is a runner, 3 is a casing, 4 is a rotating shaft, 5 is an inlet pipe, 6 is a water discharge pipe, 7 is a guide vane, 7a is a downstream end, 8
are reinforcing ribs.

Claims (1)

[Scope of utility model registration request] The inner side of the downstream tip of the guide vane, which is provided on the upstream side of the runner housed in the casing and has an airfoil-shaped cross section and which guides water to the runner and adjusts the amount of water, is formed into a plate shape that approximates the outer shape. A guide vane for a cross-flow water turbine, characterized in that a reinforcing rib along the water flow direction is provided inside the tip part.