JPS5911823B2 - solar pond - Google Patents

Description

[Detailed description of the invention] The present invention relates to solar ponds.

A solar pond is a device that stores solar heat in, for example, pond water.

Conventionally, measures have been taken to reduce heat radiation by, for example, utilizing the concentration (density) of salt solutions in order to maintain a high solar heat collection temperature.

The structure of a conventional general solar pond will be explained based on FIG.

A solar pond is generally divided into two layers, upper and lower, by a transparent diaphragm 1, as shown in the figure.

The upper layer is called the non-convective layer 2 and the lower layer is called the convective layer 3. Sunlight passes through the upper non-convective layer 2 and is stored in the lower convective layer 3.
Low-temperature water A is heat-stored in this convection layer 3 and leaves as high-temperature water B.

In the non-convection layer 2, a concentrated solution C of salts flows in from the lower part, and fresh water flows in from the upper part, and these are mixed to reduce the concentration (dilute solution → E is the solution C in the non-convection layer 2). It is discharged from the middle part.

By forcing the salt to flow in this way, a continuous salt concentration gradient is formed from the bottom to the top, as shown in the concentration gradient line shown in FIG.

By appropriately selecting the type of salt in the non-convection layer 2 and the concentration of the concentrated solution C to be supplied, a density gradient is formed in accordance with the concentration gradient.

By creating this density gradient, it is possible to prevent a density difference from occurring due to a temperature difference, thereby preventing the occurrence of convection due to buoyancy, thereby forming a non-convection layer 2.

Therefore, even if the temperature in the lower part rises, convection is prevented in the non-convection layer 2 due to the concentration gradient, which in turn can prevent heat radiation, and can store heat for a long time.

However, according to the structure of this solar pond, although fresh water flows from the top, it is directly affected by weather and external factors such as wind and rain, so there is a large amount of heat dissipated by convection, making it difficult to maintain the concentration gradient. requires considerable effort.

The present invention overcomes the drawbacks of the solar pond and provides an effective and economical solar pond by simple means.

An embodiment of the present invention will be described below based on the drawings.

Figure 3 shows the structure of the solar pond of the present invention, in which a translucent transparent diaphragm 1 is provided at two locations, at the top and bottom of the water tank, to separate it into three layers, and the top layer is a convective layer 4 consisting of fresh water and rainwater. In the middle layer, fresh water is introduced from directly below the upper diaphragm 1a, and concentrated salt solution C is introduced from directly above the lower corner Jlb, and these are mixed to form a solution whose concentration has decreased (the diluted solution E is the The non-convection layer 2 has a structure that drains water from the center of the intermediate layer, and the bottom layer has a convection layer 3 that collects solar heat.

As in the case of FIG. 1 described above, low temperature water A is heat-stored in this convection layer 3 and leaves as high temperature water B.

With this structure, the upper diaphragm 1a prevents external conditions such as rain and wind from affecting the non-convection layer 2, so as shown in FIG.
By always creating a stable concentration gradient, radiation of solar heat stored in the convective layer 3 can be effectively suppressed.

In this embodiment, the concentration of the salt solution 5 in the non-convection layer 2 was set so as to gradually decrease from top to bottom. In place of No. 5, transparent oil that can reduce thermal conductivity may be used.

As described above, according to the present invention, there are two translucent transparent diaphragms at the upper and lower parts of the aquarium, and the solution has a higher thermal conductivity than directly below the upper diaphragm, and a solution having a lower thermal conductivity than directly above the lower diaphragm. The solution is passed through, the mixed solution is drained from the central area between the diaphragms, and the lower side of the lower diaphragm is used as a convection layer, eliminating external influences from weather such as rain and wind and reducing the concentration in the non-convective layer. It is possible to reliably maintain the gradient (thermal conductivity gradient) in a constant state at all times, and the effect of storing solar heat more stably than conventional solar ponds and suppressing the amount of heat radiation is very large.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the structure of a conventional solar pond, FIG. 2 is a diagram showing the concentration gradient of salts in the solar pond of FIG. 1, and FIG. 3 is a vertical sectional view showing the structure of the solar pond of the present invention. FIG. 4 is a diagram showing the concentration gradient of salts in the solar pond shown in FIG. 1...Transparent diaphragm, 2...Non-convection layer, 3
... Convective layer, C ... Concentrated solution of salts,
D: Fresh water, E: Diluted solution.

Claims (1)

[Claims] 1 A water tank has two translucent transparent diaphragms at the top and bottom, and a solution with higher thermal conductivity is passed directly below the upper diaphragm, and a solution with lower thermal conductivity is passed directly above the lower diaphragm. A solar pond that drains the mixed solution from the central area and uses the area under the lower diaphragm as a convection layer.