JP2642862B2 - Water temperature control method of dam lake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a water temperature of a dam lake.

[0002]

2. Description of the Related Art In a dam lake, there is a problem that a gorgeous odor of water is generated due to eutrophication due to abnormal growth of undesired algae such as cyanobacteria. Therefore, in order to suppress the growth of algae and solve such problems, the water temperature control method of the dam lake was conventionally adopted.As the water temperature control method of the dam lake, an intermittent pumping cylinder was installed in the dam lake. By supplying cold water in the deep part of the reservoir to the surface part and forming a circulating mixed layer in the surface part of the dam lake, the temperature of the surface water in which algae are present is lowered, and the activity of the algae is reduced. And the creation of large circulations throughout the reservoir.

[0003] However, since the circulating mixed layer formed by the above-mentioned intermittent pumping cylinder is thin, a large amount of nutrients of algae, which flow in large quantities during floods and have a lower temperature than the surface water of the reservoir, are contained. Will be mixed with surface water at the upstream end of the reservoir. Thus, there is a problem that a large amount of nutrient components of algae may be mixed into the circulating water layer.

[0004]

Therefore, in order to solve the problems of the conventional water temperature control method for dam lakes,
The inventors of the present application have proposed a flow control method in a reservoir area as disclosed in Japanese Patent Application No. 4-92164. This method controls the supply of light to suspended algae by flowing the lake water of the dam lake using an acid-type aeration device and thickening the circulating mixed layer, and at the same time, inflowing river water into the lower layer. Thus, nutrients to suspended algae inhabiting the euphotic layer are suppressed.

However, such a method of controlling the flow in a dam lake makes the vertical distribution of the water temperature of the dam lake uniform during spring or large-scale flooding where the temperature of the inflowing river water is higher than the surface temperature of the dam lake. If the heat supply to the dam lake is small due to abnormal weather, etc., the temperature of the inflowing river water is high and the formation of a circulating mixed layer deeper than the luminous layer and the inflow of the inflowing river water into the deep layer However, there is a problem that it is difficult to suppress the growth of floating algae.

Accordingly, an object of the present invention is to solve the problems of the conventional flow control method in a dam lake as described above, and to provide a spring or large-scale flooding where the temperature is higher than the water temperature of the dam lake and the radiant heat is large. Even if the vertical distribution of the water temperature of the dam lake becomes uniform due to the above, or even if the amount of heat supplied to the dam is small due to abnormal weather, etc., the temperature of the inflowing river water is higher than the water temperature of the circulating mixed layer deeper than the luminous layer. It is an object of the present invention to provide a method for controlling the temperature of water in a dam lake, which can be easily formed and flow into the deep water of an inflowing river and can suppress the growth of suspended algae.

[0007]

According to the present invention, in order to achieve the above-mentioned object, the invention of claim 1 is characterized in that the inflow water temperature control section 4 includes a first high-temperature cold water pipe from the inflow river 2 to the heat radiation side. After taking in high-temperature cold water by 13 and storing heat in the first heat pump 11, low-temperature cold water is discharged to the inflow river 2 by the first low-temperature cold water pipe 14 on the heat radiation side, while the outlet and outlet of the inflow water channel 3 are discharged. The low-temperature hot water is taken from the circulating mixing layer 7 on the upper side of the thermocline 8 extending between the water-cooling layer 5 and the second low-temperature hot water pipe 17 on the heat receiving side, and after the heat is radiated by the first heat pump 11,
It is discharged as high-temperature hot water to the circulating mixing layer 7 by the second high-temperature hot water pipe 16 on the heat receiving side to raise the water temperature of the circulating mixing layer 7 and to lower the temperature of the river water flowing into the dam lake 1. It is assumed that. The invention of claim 2 is
In the all-layer water temperature control section 6, high-temperature cold water is taken from the deep layer 9 below the water temperature step 8 extending between the outlet of the inflow water channel 3 and the outlet 5 by the fourth high-temperature cold water pipe 21 on the radiation side. Then, after storing the heat in the second heat pump 12, low-temperature cold water is discharged to the deep layer 9 by the fourth low-temperature cold water pipe 22 on the heat radiation side, while low-temperature hot water is discharged from the circulation mixing layer 7 by the third low-temperature hot water pipe 18 on the heat receiving side. After water is taken out and radiated by the second heat pump 12, it is heated as high-temperature hot water by a third high-temperature hot-water pipe 19 on the heat-receiving side, on the upper side of the thermocline 8 extending between the outlet of the inflow channel 3 and the outlet 5. The effluent is discharged to the circulating mixing layer 7,
And the water temperature of the deep layer 9 is lowered. According to a third aspect of the present invention, in the first or second aspect, the first and second heat pumps 11 and 12 utilize waste heat generated by the cooling means 24 around the dam lake. It is.

[0008]

In the above-mentioned method, when implementing the inflow water temperature control method, high-temperature cold water is taken from the inflow river and discharged to the inflow river as low-temperature cold water cooled by the water temperature lowering means. In the dam lake, hot water having a low temperature is taken from a lake above a predetermined altitude, and discharged as high-temperature hot water heated by a water temperature raising means into lake water above a predetermined altitude in the dam lake. In this way, the temperature of the lake water above the predetermined altitude in the dam lake is raised, the temperature of the river water flowing into the dam lake is lowered, and the temperature of the incoming river water is lower than the natural state. Flows into the dam lake at a depth lower than the case where only the temperature of the lake water above the predetermined altitude is raised. Simultaneously with such an inflow water temperature control method, a full-layer water temperature control method is carried out. In this full-layer water temperature control method, high-temperature cold water is taken from lake water below a predetermined altitude of a dam lake, and a water temperature lowering means is provided. While discharging as low-temperature cold water to the lake water below the predetermined altitude of the dam lake, taking low-temperature hot water from the lake water above the predetermined altitude in the dam lake, and As a warm water, the water is released into the lake above the specified altitude in the dam lake, raising the temperature of the lake above the specified altitude in the dam lake and lowering the temperature of the lake below the specified altitude in the dam lake . The amount of heat supplied to the lake water above the predetermined altitude in the dam lake in this way, together with the amount of heat generated by the inflow water temperature control method,
The water diffuses into all the lake water above the predetermined altitude in the dam lake to increase the water temperature there, and the water temperature lowering means lowers the water temperature of the lake water below the predetermined altitude of the dam lake. At that time, the waste heat generated by the cooling means during the period when the district cooling is being performed around the dam lake is used, and thus the improvement of the lake water quality of the dam lake and the district cooling are both achieved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in FIG. 1, 1 is a dam lake, 2 is an inflow river, 3 is an inflow channel extending from a river to the middle bottom of the dam lake 1, and 4 is an outside of the inflow side of the dam lake 1. The inflow water temperature control unit provided in the 5 is the outlet of dam lake 1,
6 is a full-layer water temperature control unit provided outside the outflow side of the dam lake 1, 7 is a circulating mixed layer above the dam lake 1, and 8 is an outlet of the inflow channel 3 formed below the circulating mixed layer 7. An intermediate thermocline extending between the outlet and the outlet 5, and 9 represents a deep layer below the thermocline. The inflow water temperature control unit 4 has a first heat pump 11 provided on the inflow side, and the first heat pump 11
And the first high-temperature cold water pipe 13 and the first low-temperature cold water pipe 14, while the circulating mixing layer 7, the second high-temperature hot water pipe 16, and the second low-temperature hot water pipe
Connected at 17.

The full-layer water temperature control section 6 has a second heat pump 12 provided on the outflow side, and the second heat pump 12 is connected to the circulation mixing layer 7 by a third low-temperature hot water pipe 18 and a third high-temperature hot water pipe 19. On the other hand, the deep layer 9, the fourth high temperature cold water pipe 21, the fourth low temperature cold water pipe 22
The fourth low-temperature chilled water pipe 22 is supplied with air via an air supply pipe (not shown), and a bowl-shaped lid member is provided in the deep layer 9 above the fourth low-temperature chilled water pipe 22. 23, the first and second heat pumps 11 and 12 are connected to cooling means 24 in the area around the dam lake by pipes 25 and 26, and the top is open to the circulation mixing layer 7. A diffuser member 27 supplied through an air supply pipe (not shown) is installed at the bottom of the lake. Reference numerals 28, 29; 31, 32 denote first and second circulation flows in the circulating mixed layer 7 and the deep layer 9, respectively, and 33 denotes inflowing river water, respectively.

When the inflow water temperature control method is performed in the above-described manner, the inflow water temperature control section 4 draws high-temperature cold water from the inflow river 2 by a first high-temperature cold water pipe 13 and supplies the first heat pump 11 After storing the heat, the first low-temperature cold water pipe 14 discharges low-temperature cold water to the inflowing river 2, while the second low-temperature hot water pipe 17 draws low-temperature hot water from the circulating mixed layer 7, and releases heat by the first heat pump 11. ,
The water is discharged as high-temperature hot water to the circulating mixing layer 7 through the second high-temperature hot-water pipe 16 to raise the water temperature of the circulating mixing layer 7 above a predetermined altitude in the dam lake 1 and to flow into the dam lake 1 from the inflow channel 3. Reduce the temperature of river water. In this way, the temperature of the inflowing river water is lower than the temperature of the circulating mixing layer 7. Therefore, the inflowing river water has a lower water depth than the case where the water temperature of the circulating mixing layer 7 in the dam lake 1 is merely increased. Flows into the place.

Simultaneously with such an inflow water temperature control method, a full-layer water temperature control method is carried out. In this full-layer water temperature control method, high-temperature cold water is taken from the deep layer 9 by a fourth high-temperature cold water pipe 21, 2 After storing heat in the heat pump 12, low-temperature cold water is discharged to the deep layer 9 by the fourth low-temperature cold water pipe 22.
Low-temperature hot water is taken from the circulating mixing layer 7 by the third low-temperature hot water pipe 18, heat is radiated by the second heat pump 12, and then discharged as high-temperature hot water to the circulating mixing layer 7 by the third high-temperature hot water pipe 19. While raising the water temperature of the circulation mixing layer 7 inside, the water temperature of the deep layer 9 is lowered. The amount of heat supplied to the circulating mixing layer 7 in this manner is supplied to the circulating mixing layer 7 generated by the inflow water temperature control method by the first circulating flow 28 generated by the air diffusing from the opening of the diffusing member 27 installed at the lake bottom. With the amount of heat supplied to the dam lake 1, the water diffuses into the whole circulation mixed layer 7 and raises the water temperature there.

The water temperature difference generated by this full-layer water temperature control method plays a role in increasing the flow capacity in the deep layer 9 as well as in the circulation mixing layer 7. Fourth low-temperature cold water pipe as described above
The low-temperature cold water discharged from 22 is mixed with air bubbles, is entrained by this, rises and reaches the water depth of the lid member 23, and a water temperature difference occurs between the low-temperature cold water and the second circulation flow 32 at the upper end of the deep layer 9. , Deep 9
In this case, the second circulation flow 32 can have an efficient flow capacity. Further, the discharge of the bubbles in the deep layer 9 is performed for the purpose of improving the dissolved oxygen in the deep layer 9, but the low-temperature cold water discharged from the fourth low-temperature cold water pipe 22 has a low water temperature even in the deep layer. After arriving at the member 23, a part thereof is separated from the first circulating flow 31 and becomes the second circulating flow 32, and diffuses in the deep layer 9 over the lake bottom because of the low water temperature. Then, the water is released from the fourth low-temperature cold water pipe 22 to form an underwater surface on the lower surface of the lid member 23 due to the bubbles when released from the fourth low-temperature cold water pipe 22, and the aeration on the surface of the water surface also improves the dissolved oxygen. It is possible to efficiently improve the dissolved oxygen in the deep layer 9, particularly just above the bottom mud.

The first and second heat pumps 11 and 12 are:
In the inflow and all-layer water temperature control method, the waste heat generated by the cooling means 24 during the district cooling around the dam lake 1 is used. It will be compatible with cooling.

FIGS. 2 to 7 show the results of a simulation of the vertical distribution of the water temperature of the dam lake and the inflow depth of the river water. C shows the state at the time of no countermeasure when the flow control method according to the already proposed method is implemented. From now on, in each season from spring to summer, the vertical temperature distribution of water temperature in the circulating mixed layer 7 rises by the A and B methods, and the inflow water depth of the inflowing river 2 is the deepest in the A method, and this tendency is continuous in summer. It can be confirmed even in the case of small- and medium-scale floods that have occurred. As can be seen from FIGS. 2 to 6, in the case of the method C, the clear surface layer exists as deep as 10 m deeper than in the case of the other methods. You can see that.

[0016]

As described above, the present invention relates to claims 1 and 2.
According to the invention, the temperature of the lake water above the predetermined altitude in the dam lake is raised by the water temperature raising means, and the temperature of the river water flowing into the dam lake or the temperature of the lake water below the predetermined altitude of the dam lake is lowered by the water temperature lowering means. Since the temperature is higher than the water temperature of the dam lake and the vertical distribution of the water temperature of the dam lake becomes uniform due to spring or large-scale flooding with large radiant heat, or heat supply to the dam lake due to abnormal weather, etc. Even if the amount is small, the temperature of the inflowing river water is high and the formation of a circulating mixed layer deeper than the euphotic layer and the inflow of the inflowing river water into the deep layer are easy, and the growth of floating algae can be suppressed. This has the effect. According to a third aspect of the present invention, in the first or second aspect of the present invention, the heat generated by the cooling in the area around the dam lake is absorbed by the heat absorbing means. By utilizing the waste heat generated by this, there is an effect that it is possible to achieve both the improvement of the water quality of the dam lake and the district cooling in this way.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a result of a simulation of a vertical distribution of a water temperature of a dam lake in spring and a depth of inflow of river water according to this embodiment.

FIG. 3 is a diagram showing the results of a simulation of the vertical distribution of the dam lake water temperature and the inflow depth of river water in the early summer.

FIG. 4 is a drawing showing a result of a simulation of a vertical distribution of a water temperature of a dam lake in the rainy season and an inflow depth of river water.

FIG. 5 is a drawing showing a result of a simulation of a vertical distribution of a water temperature of a dam lake water and a depth of inflow of river water after the middle flood.

FIG. 7 is a drawing showing the results of a simulation of the vertical distribution of the water temperature of the dam lake water and the inflow depth of river water after the small flood.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dam lake 2 Inflow river 3 Inflow waterway 4 Inflow water temperature control part 5 Outlet part 6 Full layer water temperature control part 7 Circulation mixing layer 8 Water temperature steep layer 9 Deep layer 11 1st heat pump 12 2nd heat pump 13 1st high temperature cold water pipe 14 1 Low-temperature cold water pipe 16 Second high-temperature hot water pipe 17 Second low-temperature hot water pipe 18 Third low-temperature hot water pipe 19 Third high-temperature hot water pipe 21 Fourth high-temperature cold water pipe 22 Fourth low-temperature cold water pipe 23 Cover member 24 Cooling means 25 Pipe 26 Pipe 27 Air diffuser 28 First circulation flow 29 Second circulation flow 31 First circulation flow 32 Second circulation flow 33 Inflowing river water

Claims (3)

(57) [Claims] In an inflow water temperature control unit, an inflow river 2 is provided.
After the high-temperature cold water is taken in by the first high-temperature cold water pipe 13 on the radiating side and stored in the first heat pump 11, low-temperature cold water is discharged to the inflowing river 2 by the first low-temperature cold water pipe 14 on the radiating side, while Low-temperature hot water is taken from the circulating mixing layer 7 above the thermocline 8 extending between the outlet part of the water channel 3 and the outlet part 5 by the second low-temperature hot water pipe 17 on the heat receiving side, and the first heat pump 11 After the heat is released, the second heat receiving side
A water temperature control method for a dam lake, comprising: discharging water to a circulating mixing layer by a high-temperature hot water pipe; raising a water temperature of the circulating mixing layer; and lowering a temperature of river water flowing into the dam lake. 2. The inflow water channel 3 in the all-layer water temperature control unit 6.
The high-temperature cold water is taken from the deep layer 9 below the thermocline 8 extending between the outlet part and the outlet part 5 by the heat-radiating fourth high-temperature cold water pipe 21, and stored in the second heat pump 12. The low-temperature cold water is discharged to the deep layer 9 by the fourth low-temperature cold water pipe 22 on the heat radiation side, while the third low-temperature hot water pipe 18 on the heat receiving side is discharged from the circulation mixing layer 7.
After the low-temperature hot water is taken in, the second heat pump 12 releases the heat, and the third high-temperature hot water pipe 19 on the heat receiving side as the high-temperature hot water causes a water thermocline extending between the outlet of the inflow water channel 3 and the outlet 5. 8. A method for controlling the water temperature of a dam lake, comprising: discharging water to the circulating mixing layer 7 on the upper side of 8 and increasing the water temperature of the circulating mixing layer 7 and lowering the water temperature of the deep layer 9. 3. The dam lake water temperature control method according to claim 1, wherein the first and second heat pumps 11 and 12 utilize waste heat generated by cooling means 24 around the dam lake. .