JPH0677756B2 - Flow control equipment in the reservoir area - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for controlling flow in a reservoir or lake, and more particularly, by introducing inflow water at the time of flood containing a lot of nutrients for algae to a deep layer. , Which can reduce the mixing of the nutritional component into the surface layer.

[0002]

2. Description of the Related Art The cause of water bloom and mold odor caused by eutrophication in reservoirs is due to abnormal growth of undesired algae such as cyanobacteria. In order to suppress the growth of such undesired algae, conventionally, by installing an intermittent pumping cylinder in the reservoir and supplying cold water in the deep part of the reservoir to the surface layer, the surface layer where the algae exists. It was expected that the temperature of the water would be lowered, the activity of algae would be reduced, and a large circulation to the whole reservoir would occur.

It has been recognized that a circulating mixing layer is formed in the surface layer of a reservoir by installing such an intermittent pumping cylinder.

[0004]

However, since the circulating mixing layer formed by the intermittent pumping cylinder is thin,
Water that flows in large amounts during a flood and that contains a high concentration of algae nutrients and has a lower temperature than the surface water of the reservoir will be mixed with the surface water at the upstream end of the reservoir. As a result, a large amount of algae nutritional components may be mixed in the circulating water layer.

The present invention has been made by paying attention to such conventional problems, and by introducing inflow water containing a nutrient component of algae at a high concentration to a deep layer, the above-mentioned problem to the surface layer can be obtained. It is an object of the present invention to provide a flow control facility that can reduce the mixing of nutrients.

[0006]

In order to achieve the above object, the flow control equipment of the present invention is provided with a circulating means for circulating water above a predetermined water level in a water storage area in the depth direction, and It is characterized by the introduction of an inflow channel at the upstream end of the area that directs the inflow water to the deep layers within this reservoir.

[0007]

According to the equipment of the present invention, the circulation means forms the circulation mixing layer above the predetermined water level and maintains the same water temperature. When water containing a high concentration of algae nutrients flows in, such as during a flood, the circulation means is stopped and the inflow water is introduced from the inlet of the introduction channel into the reservoir area. It is guided and enters a layer at the same temperature as the temperature below the circulating mixing layer. As a result, water containing a high concentration of algae nutrients does not mix into the surface layer of the water storage area.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing the inside of a reservoir to which an embodiment of the present invention is applied, FIG. 2 is a sectional view showing an introduction water channel in this embodiment, and FIG. 3 is a portion of FIG. 2 viewed from the A side. FIG. 4 is a front view, and FIG. 4 is a plan view of FIG. 2.

As can be seen from FIGS. 1 and 2, a secondary dam 2 is provided at the upstream end of the reservoir 1, and the secondary dam 2 is provided.
Along the bottom surface 1a of the reservoir 1 from the slope 2a of the overflow section of
A first introduction water channel 3 having a predetermined width is provided. As shown in FIG. 4, this first introduction water channel 3 has a concrete wall 3a.
Are opposed to each other at a predetermined interval, and the upper part is open.

Further, inside the sub dam 2, a second introduction water channel 31 is provided from the dam 2b side toward the first introduction water channel 3. The second introducing water channel 31 is formed in a tunnel shape by embedding a water guiding pipe, and a tip portion 31 a thereof joins with the first introducing water channel 3. Further, the second introduction water channel 31 is connected to the switch 4
It is designed to be opened and closed by. An aeration device 5 is embedded in the sub dam 2, and the water flowing into the reservoir 1 is mixed with the water at the upstream end during normal times.

On the other hand, as can be seen from FIG. 1, an air diffuser 6 is installed slightly to the outlet side of the center of the reservoir 1.
The air diffuser 6 is provided with a large number of small air diffusers at the upper part, and has a structure in which it can be easily moved up and down to set the position of the air diffuser. According to this air diffuser 6, FIG.
As shown in the graph, the circulation mixing layer J can be formed thicker than in the conventional intermittent pumping cylinder system device 61.

A selective water intake equipment 7b is installed on the downstream side of the reservoir 1, and a pipe 7a is connected between the selective water intake equipment 7b and the discharged water purification equipment 7. As a result, water at an arbitrary water level in the reservoir 1 can be discharged downstream of the dam via the discharge water purification facility 7. Also, on the downstream side,
A selective discharge facility 8a connected to the discharge port 8 at the time of flood is installed.

Therefore, in normal times, when water that does not contain much algae nutrients flows in, the switch 4 closes the second introduction channel 31, and the overflow water from the sub-dam 2 is introduced into the reservoir 1. In addition, the air diffuser 6 is installed and operated so that the position of the air diffuser is at the lower limit water level of the clear water, and the circulation is of a sufficient thickness (for example, about four times that of the light layer). The mixed layer J is formed.

During normal times and when water containing a lot of nutrients of algae flows in, or during a small flood (when the water level of the reservoir in the sub-dam is about S2), the switch 4 opens the second introducing water channel 31. Open the inflowing water from here and introduce the first inflow channel 3
To the deep layer portion H without being mixed with the circulating mixing layer J. At the time of a large flood (when the water level of the reservoir in the sub dam exceeds S1), the air diffuser 6 is stopped and the inflow water is directed to the first introduction water channel 3 to mix it with the circulation mixing layer J as much as possible. Without leading to the deep layer H.

The high muddy water at the time of flood contains a large amount of bed load and suspended load, but the bed load is removed by the secondary dam 2.
Only suspended sediment passes through the first introduction water channel 3 and the second introduction water channel 31. In addition, since this suspended sediment is removed by flash, the maintenance of each introduction canal can be done easily. Then, after the end of the flood, the diffuser 6 is installed at the diffuser port position at the lower limit water level of the clear water to start diffuse the surface water. After that, the circulating mixing layer J having a sufficient thickness than the luminescent layer is re-formed by lowering the installation position of the air diffuser as the lower limit level of the clear water is lowered.

[0016] In normal times, the clear water is discharged from an arbitrary water level in the surface layer by the selective water intake equipment 7a and is directed to the downstream of the dam through the discharge water purification equipment 7.
With the selective water discharge facility 8a, highly turbid water at an arbitrary water level in the deep part can be discharged from the discharge port 8 at the time of flood. Furthermore, in the reservoir 1 in FIG. 1, deep DO (dissolved oxygen) is present at the bottom of the lake.
An aeration device 9A for improvement, an inflow water purification facility 9B, and a surface water purification facility 9C are also installed, and comprehensive water quality conservation measures are taken. As the aeration device 9A, a small-capacity aeration pipe system is used, and its aeration port is fixed at a height of several meters above the lake bottom so that air bubbles due to aeration are almost absorbed during the ascent of the deep layer. Prevent bubbles from reaching the circulating mixing layer J.

[0017]

As described above, according to the equipment of the present invention, inflow water containing a high concentration of algae nutrients can be introduced to the deep layer, so that the nutrients to the surface layer can be introduced. It is possible to reduce the activity of algae present in the surface water by reducing the contamination of the algae. As a result, abnormal growth of algae in the water storage area can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an introduction water channel in this embodiment.

FIG. 3 is a partial front view of FIG. 2 viewed from the A side.

FIG. 4 is a plan view of FIG.

FIG. 5 is a graph for explaining the action of the circulation means in the present invention.

[Explanation of symbols]

 1 Reservoir 3 1st introduction water channel 31 2nd introduction water channel 6 Air diffuser (circulation means)

Claims (1)

[Claims] 1. A circulation means for circulating water above a predetermined water level in a water storage area in a depth direction is provided, and an inlet water channel for directing inflow water to a deep layer in the water storage area is provided at an upstream end of the water storage area. Flow control equipment in the water storage area characterized by being provided.