JPH0426695Y2 - - Google Patents

Description

[Detailed description of the invention] <Field of industrial application> This invention is a cross-flow water turbine that prevents noise and vibration by alleviating pressure changes that occur between the runner blades and the water flow guide as the runner rotates. Regarding.

<Prior Art> Cross-flow water turbines in which a water flow flows through a runner are widely used to generate electricity using water flow such as wastewater from a plant. As shown in Fig. 4, which shows a typical structure of a cross-flow turbine, a runner 2 is formed into a cylindrical cage-like shape by radially arranging a large number of runner blades 1 having airfoil-shaped cross-sections. Casing 4 with runner shaft 3
At the outlet end of the inlet pipe 5 which is rotatably supported by the casing 4 and is connected to the casing 4 and provided on the upstream side of the runner 2, there is a curved plate-shaped water flow guide 6 that guides the water flow from the inlet pipe 5 into the runner 2. is provided. On the other hand, a water discharge pipe 7 connected to the casing 4 is provided on the downstream side of the runner 2, and the water flow flowing in from the inlet pipe 5 is guided by a water flow guide 6 and flows through the inside of the runner 2, causing the runner 2 to rotate. After that, the water is drained from the water discharge pipe 7. Note that 8 is a movable vane that adjusts the amount of water.

Here, as shown in FIGS. 5a and 5b, the tip side 6a of the water flow guide 6 is set to be extremely close to the outer peripheral surface of the runner 2 while maintaining a certain distance, and the outer peripheral surface of the runner 2 and the water flow guide 6 This prevents leakage of water flow from the gap A between the tip of the pipe and the tip of the pipe, thereby making efficient use of hydraulic power.

<Problem to be solved by the invention> In the conventional water flow guide 6 as described above, the tip side 6a of the water flow guide 6 is parallel to and close to the outer edge 1a of the runner blade 1 while maintaining a constant distance. Therefore, when the runner 2 rotates in the direction of the arrow in the figure and the outer edge 1a of the runner blade 1 passes near the water flow guide tip edge 6a, a sudden pressure change occurs, which induces noise and vibration and also releases hydraulic energy. This resulted in a loss of .

The present invention was developed in view of the above-mentioned conventional problems, and efficiently guides water flow to the runner to alleviate pressure changes caused by the rotation of the runner, thereby preventing the generation of noise and vibration and loss of hydraulic energy. The purpose of the present invention is to provide a cross-flow water turbine equipped with a water flow guide.

<Means for Solving the Problems> The cross-flow turbine according to the present invention includes a runner that is rotationally driven by a water flow, and a runner that is located upstream with respect to the runner and whose tip side maintains a certain distance from the outer peripheral surface of the runner. A cross-flow turbine comprising water flow guides formed in adjacent plate shapes and guiding the water flow into the runner, wherein the runner blades constituting the runner have a tip side of the water flow guide inclined with respect to an outer edge. It is characterized by:

<Operation> A water flow flowing along a water flow guide provided on the upstream side of the runner is guided to the runner blades constituting the runner and hits the runner blades, thereby rotating the runner of the cross-flow water turbine. At this time, the tip of the water flow guide is provided at an angle and at a certain distance from the outer edge of the runner blade, so that when the runner blade passes near the water flow guide, the inflowing water flow is blocked at once. The water is gradually pressed against the runner blade, suppressing sudden pressure fluctuations in the water flow.

An embodiment of a cross-flow water turbine according to the present invention will be described with reference to the drawings. Note that the same parts as those in the conventional cross-flow water turbine described above are designated by the same reference numerals and detailed description thereof will be omitted.

Figures 1a, b, and c relate to the first embodiment of the present invention, and Figures 1a and b are sectional views and perspective views, respectively, showing the relationship between the water flow guide and the runner according to the present embodiment.
FIG. 1c is a plan view of the tip of the water flow guide according to this embodiment.

As shown in the figure, the water flow guide 6 of this embodiment is formed by continuously changing the curvature of its tip so that the radius of curvature R ₁ on one side is larger than the radius of curvature R ₂ on the other side. In addition, the tip side 6a of the water flow guide is formed obliquely with respect to the longitudinal direction, and the tip side 6a of the water flow guide 6 is close to the outer circumferential surface of the runner 2 with a certain gap and is located close to the runner 2. It is inclined with respect to the outer edge 1a of the blade 1.

Therefore, when the runner 2 rotates, the outer edge 1a of the runner blade 1 is at one time connected to the water flow guide 6.
Rather than passing close to the tip side 6a, the water flow gradually passes across the tip side 6a, so that no sudden pressure change occurs between the runner blade 1 and the water flow guide 6. For this reason, the tip side 6a of the water flow guide 6 is brought close to the outer circumferential surface of the runner 2 at a constant distance, so that efficient use of hydraulic power can be achieved without causing noise vibration or loss of hydraulic energy. The illustrated water flow guide 6 is provided with a band-shaped covering portion 6b that closely follows the outer peripheral surface of the runner 2 at its tip, and this covering portion 6b prevents the water flow from scattering and allows the water flow to flow efficiently into the runner 2. In such a water flow guide 6, it is preferable that both the tip side 6a and the covering part 6b be inclined with respect to the outer edge 1a of the runner blade. Further, in this embodiment, the skew amount S of the water flow guide tip end side 6a is set to approximately 1 pitch of the runner blade 1, but a particularly large effect can be expected if at least 1/2 pitch is secured.

Figures 2a and b relate to the second embodiment of the present invention, Figure 2a is a perspective view showing the relationship between the water flow guide and the runner according to this embodiment, and Figure 2b is the water flow according to this embodiment. FIG. 3 is a plan view of the tip of the guide.

As shown in the figure, the water flow guide 6 of this embodiment is formed so that the curvature of its tip portion changes continuously, and the radius of curvature _R1 of the center portion is larger than the radius of curvature _R2 of both sides.
The water flow guide 6 has a tip edge 6a that is close to the outer peripheral surface of the runner 2 with a certain interval and is aligned with the outer edge 1a of the runner blade 1.
is inclined relative to

Therefore, in this embodiment, as in the above-described embodiments, pressure changes between the runner blade 1 and the water flow guide 6 can be alleviated, and hydraulic power can be used efficiently without generating noise or vibration.

Figures 3a, b, and c relate to the third embodiment of the present invention, Figure 3a is a perspective view of the tip of the water flow guide of the present invention, and Figure 3b is viewed from the - arrow in Figure 3a. The sectional view, FIG. 3c, is a sectional view taken along the - arrow in FIG. 3a.

As shown in the figure, the water flow guide 6 of this embodiment has a tip side 6a shaped like two chevrons arranged side by side in the same manner as in the above embodiment, and this tip side 6a is aligned with the outer peripheral surface of the runner 2. They are arranged close to each other at a constant interval and are inclined with respect to the outer edge 1a of the runner blade 1, and as in the above embodiments, efficient use of hydraulic power can be achieved without producing noise or vibration. In addition, this water flow guide 6 has a covering portion 6b provided with a portion having a large radius of curvature, and a recess 6c facing the outer circumferential surface of the runner 2 is formed in the covering portion 6b. The cross-sectional area of the flow path B formed by the and covering part 6b is expanded, and a relatively high static pressure upstream is introduced into the flow path B, thereby preventing the occurrence of cavitation due to a decrease in the pressure of the water flow in the flow path B. are doing.

Note that the water flow guide for the cross-flow turbine of the present invention is not limited to the above-mentioned embodiments, and may have any shape as long as the tip side is inclined with respect to the outer edge of the runner blade. Also good.

<Effects of the invention> As explained above, according to the invention, since the tip side of the water flow guide of the cross-flow turbine is inclined with respect to the outer edge of the runner blade, the contact between the runner blade and the water flow guide is reduced as the runner rotates. By alleviating the pressure changes that occur between the runners, it is possible to prevent the generation of noise and vibration and loss of hydraulic energy, and by keeping the tip of the water flow guide close to the outer circumferential surface of the runner while maintaining a certain distance, efficient use of hydraulic power can be achieved. This can be achieved without any problems.

[Brief explanation of the drawing]

Figures 1a, b, and c relate to the first embodiment of the present invention; Figure 1a is a sectional view of the tip of the water flow guide;
Figure b is a perspective view showing the relationship between the water flow guide and the runner, Figure 1 c is a plan view of the tip of the water flow guide, and Figure 2
Figures a and b relate to the second embodiment of the present invention;
is a perspective view showing the relationship between the water flow guide and the runner, Figure 2b is a plan view of the tip of the water flow guide, and Figure 3a,
Figures b and c relate to the third embodiment of the present invention; Figure 3a is a perspective view showing the relationship between the water flow guide and the runner;
Figure b is a sectional view taken along the - arrow in Figure 3a, Figure 3c
is a sectional view taken along the - arrow in Fig. 3a, Fig. 4 is a partially cutaway overall perspective view showing the structure of a typical cross-flow turbine, and Figs. 5a and 5b are respectively conventional water flow guides. FIG. 3 is a cross-sectional view and a perspective view showing the relationship between the runner and the runner. In the drawing, 1 is the runner blade, 1a is the tip side,
2 is a runner, 6 is a water flow guide, and 6a is an outer edge.

Claims (1)

[Scope of utility model registration request] A runner that is rotationally driven by a water flow, and a plate-shaped runner that is located upstream of the runner and whose tip side is close to the outer peripheral surface of the runner at a constant distance to guide the water flow into the runner. A cross-flow water turbine comprising a water flow guide, characterized in that a tip side of the water flow guide is inclined with respect to an outer edge of a runner blade constituting the runner.