JPS6328985Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a device that deenergizes high-energy water discharged from a water discharge pipe provided deep in a water storage dam.

[Prior art and its problems]

A jet flow gate or hollow jet valve is installed at the downstream opening of the water discharge pipe installed in the deep part of the water storage dam, and after the discharged water with high energy is adjusted in flow rate by the gate or valve, As shown in the figure, the water is discharged into a deenergization tank composed of a side wall and an end sill, where it is subjected to diffusion effects due to underwater jet diffusion and collision with the end sill, and after being deenergized, it is discharged over the end sill. It's becoming like that. However, in the energy reducing tank as shown in FIG. 1, when the water head becomes high, the energy reducing tank becomes long and the water surface fluctuates violently, so that the desired energy reducing effect cannot actually be obtained. In order to solve this problem, several types of devices as shown in FIGS. 2 to 7 have been disclosed. Note that in these devices, 1 is a water discharge pipe, 2 is a flow rate regulating device consisting of a gate or a valve, 3 is an energy reducing tank, 4 is a side wall forming the energy reducing tank 3, and 5 is an end sill.

By the way, what is shown in FIGS. 2 and 3 is intended to suppress water level fluctuations caused by the upward flow of the jet after it collides with the end sill 5. A flat plate 6 is disposed on top of the water tank 5 to forcibly suppress water level fluctuations. However, with this method, when the water head becomes high, the flat plate 6 needs to be quite large, and it is extremely difficult to construct it as a civil engineering structure.
In addition, in Fig. 3, a projecting edge 7 is provided on the front surface of the upper end of the end sill 5, and the rising water is forcibly reflected forward by the wave-returning effect caused by this, aiming at a force-reducing effect by the formation of a so-called vortex. In the case of high water head, it does not function well and it is not possible to avoid rising fluctuations in the water level upstream of the energy reduction tank.

Next, the systems shown in FIGS. 4 and 5 are both aimed at reducing energy by dispersing the jet flow.
In other words, in FIG. 4, a plurality of rod-like members 8 are arranged upright on the downstream side of the opening at the end of the water discharge pipe, and as the jet water passes through these rod-like members 8, a vortex row is formed on the downstream side. However, it is difficult to install a rod-shaped member that can withstand the vibrations promoted by the high-speed jet and the generation of the vortex street, and furthermore, the high energy of the discharged water is reduced by the Karman vortex street. There are limits to how much power can be reduced solely by

Furthermore, the structure shown in FIG. 5 is a structure in which jet flow dividing members 9 are installed upright and their top ends are connected by a canopy material 10. Although this is intended to reduce the force, there is a limit to its force reduction effect, similar to the one shown in FIG.

Furthermore, in the one shown in FIG. 6, a deflector 11 with a large number of holes is installed, and a part of the water jet is ejected from the holes and diffused, and the remaining water is turned into a vortex at the front of the deflector 11. After that, the upper part was made to overflow, but with this device it was difficult to construct holes, and simply allowing the flow to flow through the holes did not have a sufficient energy-reducing effect, and with small holes, most of the jet water As the water has no choice but to overflow the deflector, it is inevitable that the water level will rise rapidly.

Further, in the device shown in FIG. 7, a plurality of vertical piers 12 are arranged in parallel at regular intervals in the width direction of the tank, and a concave deflector 13 is formed on the front surface of the end sill 5, so that a part of the jet water is applied to the vertical piers 12. The flow is changed upward to form a vortex, and the water that has passed between the baffle piers 12 is deflected downward by a deflector 13 and rotated to reduce energy. However, with this device, unless sufficient consideration is given to the relative positions and dimensions of the buffer pier 12, the energy reducing tank 3, and the water discharge pipe, it is not possible to obtain the desired energy reducing effect.

To summarize the various conventional devices mentioned above, none of them can be expected to have a force-reducing effect, especially at times of high water head, and there are concerns that the water surface will fluctuate violently and generate noise. No concrete structure with dimensional values, which are considered as technical conditions for implementation, is shown at all, and the invention merely discloses the energy-reducing tank and the concept required for it.

[Purpose of invention]

This device has the simplest structure possible, and is the most effective energy reducing device with limited numerical values.It can sufficiently reduce energy even in particularly high water heads, and can suppress ripples on the water surface and noise. The purpose of this invention is to provide a device and solve the above-mentioned conventional problems.

[Structure of the idea]

This idea is based on the idea that a vertical pier is installed approximately in the center of a deenergization tank connected to a dam water pipe, facing the opening at the end of the water pipe, and having a width of 1 to 3 times the diameter of the water pipe. It is characterized by the fact that it has been established.

〔Example〕

This invention will be explained below based on an embodiment shown in FIGS. 8 and 9. In the drawings, parts that are the same as those of the conventional device are designated by the same reference numerals.

That is, 14 is a vertical pier installed approximately in the center of the energy reducing tank 3, which faces the opening at the end of the water discharge pipe 1, and its width is determined within a range of 1 to 3 times the diameter of this water discharge pipe. be done.

Therefore, the water flow that has passed through the water discharge pipe 1 is discharged into the energy reduction tank 3 via the flow rate adjustment equipment 2, and while the discharged water containing high energy is diffused in the water, the high-speed flow in the center is The off-center jet flows between the pier 14 and the side wall 4 and interferes with the flow deflected by colliding with the pier 14, causing agitation. It flows rearward while being attenuated by the action, further collides with the end sill 5, forms a vortex, and is diffused and attenuated.

〔Concrete example〕

Specific examples based on the dimensional values of this invention are as follows.

That is, based on the water discharge pipe diameter D, the width of the energy reducing tank B = 3 to 5D, the length of the energy reducing tank L = 8 to 15D, and the height of the end sill (distance above the center of the water discharge pipe) H
= 3 to 5D, step depth y ₁ = 1.5D or more, width of the vertical pier b = 1 to 3D, position of the vertical pier x = 3D to 8D (standard is approximately the center of the length of the energy reducing tank),
The height of the full pier is set to y ₂ =1D to 2D.

[Effect of idea]

According to this invention, the jet energy discharged into the energy reducing tank is diffused underwater up to the buttful pier, is deflected by colliding with the buttful pier, is mixed with the water flow flowing between the side wall and the buttful pier, and is diffused to the end sill. collision, mixing and diffusion between the end sill and the back of the buttful pier, and force is effectively reduced over the entire tank area, thereby preventing local water level rise and achieving a uniform water surface.

[Brief explanation of the drawing]

Figures 1 to 7 are explanatory diagrams showing the structure of a conventional energy reducing tank, Figure 8 is a plan view showing an embodiment of this invention, and Figures 9a and b are cross sections taken along line X-X in Figure 8. It is a diagram. 1 is a water discharge pipe, 2 is a flow rate adjustment equipment, 3 is a deenergization tank,
4 is the side wall, 5 is the end sill, and 14 is the buttful pier.

Claims (1)

[Scope of utility model registration request] A vertical pier is erected approximately in the center of the energy reducing tank connected to the dam water discharge pipe, facing the end opening of the water discharge pipe and having a width of 1 to 3 times the diameter of the water discharge pipe. A dam water discharge energy reducing device featuring: