JPS62102884A - Fresh water generator - Google Patents

Abstract

PURPOSE:To generate fresh water at a low cost by blowing dry air dehumidified by cooling against a light receiving surface covering a pond to prevent the frosting on the light receiving surface, and utilizing solar energy with high efficiency. CONSTITUTION:The upper structure 10 for hermetically sealing a shallow pond 1 is separated by a partition wall 11 into an air chamber 12 and a cooling chamber 13. The front, side, and ceiling surfaces of the air chamber 12 are formed with a transparent light receiving surface 20. A heat exchanger obtained by connecting the upper header 14 and the lower header 15 with a cooling pipe 16 is provided in the cooling chamber 13. The lower header 15 is immersed in the water in a water collecting tray 3, and the lower header 15 is communicated with the pond 1 by piping. Namely, seawater, etc., in the pond 1 is evaporated by solar energy, the steam is efficiently cooled by the heat exchanger with the makeup seawater, and fresh water is obtained in the water collecting tray 3. The frosting on the light receiving surface covering the pond is prevented by blowing dry air dehumidified by cooling against the light receiving surface.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a water generation device, and more particularly to a simple and energy-saving water generation device for obtaining fresh water from seawater or the like using solar energy. .

[Conventional technology]

Conventionally, methods for producing fresh water from highly concentrated salt water such as seawater (Blackish water, hereinafter referred to as seawater, etc.) include evaporation method, reverse osmosis method, and electrodialysis method, which are known as devices for obtaining high-quality fresh water on a large scale. It is being However, water production using these methods requires extremely large initial investment capital, and energy costs (steam and electricity costs) as running costs.
Because of the large amount of oil produced, commercial plants are currently operating only in some oil-producing countries. It is hoped that a simple and inexpensive launching device will emerge that will be economically viable even on remote islands in Japan and in non-oil producing countries.

In order to reduce energy costs, it is a good idea to use natural energy as an energy source. A simple water generating device using solar energy as shown in FIG. 4 is known.

This device surrounds a shallow pond 1 with a transparent tent 2 made of vinyl or the like, and fills the pond 1 with seawater or the like. The water in the pond 1 absorbs sunlight and becomes high temperature, and the air inside the tent 2 is also heated to a high temperature. The water in the pond 1 evaporates, is cooled on the surface of the tent 2, condenses on the surface of the tent 2, and accumulates in the water collection tray 3. In this case, if seawater or the like is sprinkled on the outer surface of the tent 2 from the water sprinkler pipe 4, dew condensation on the surface of the tent 2 will be promoted, which is efficient.

[Problem that the invention seeks to solve]

However, the disadvantage of this method is that condensation inside the tent 2 obstructs the transmission of sunlight, and when water is sprinkled on the surface, the loss of solar energy increases due to reflection, etc. At the same time, salt crystals form on the surface. As a result, sunlight transmission through the tent 2 becomes worse. Therefore, although this method is extremely simple, it cannot be expected to produce much water.

An object of the present invention is to improve this conventional device and provide a low-cost water generation device using solar energy that is simple but highly efficient and suitable for large-scale water generation.

Means for Solving Problem C] In order to achieve the above object, the freshwater generating device according to the present invention includes a pond filled with seawater, etc., this pond is covered with a transparent enclosure, the inside of which is partitioned with a partition wall, and air It is characterized by comprising an upper structure forming a chamber and a cooling chamber, a heat exchanger provided in the cooling chamber, and a water collecting tray for collecting water condensed in the heat exchanger.

[For production]

That is, in short, the present invention evaporates seawater in a pond using solar energy, cools it while efficiently exchanging heat with supplementary seawater, and obtains fresh water. This is a water-generating device that blows dry air that has been cooled and has lost moisture to prevent dew condensation from forming on the light-receiving surface.

〔Example〕

FIG. 1 shows an embodiment of a freshwater generating apparatus according to the present invention. The shallow pond 1 is surrounded by a superstructure 10 and is formed to keep the internal air in a sealed or semi-closed state. Upper structure 1
0 is divided into an air chamber 12 and a cooling chamber 13 by a partition wall 11. The air chamber 12 has a transparent light-receiving surface 20 on the front, side, and ceiling. In addition, a heat exchanger configured by connecting an upper header section 14 and a lower header section 15 with a cooling pipe 16 is installed in the cooling chamber 13, and the lower header section 15 has water in the water collection tray 3. It is placed so that it is immersed in the water. The lower header section 15 is piped to communicate with the pond 1.

Seawater and the like are supplied from the supply water pipe 17 to the apparatus configured in this manner. Seawater or the like fills the cooling pipe 16 from the upper header 14 and reaches the pond 1 from the lower header 15. Sunlight is on the light receiving surface 2
0 to warm the water in the pond 1 and maintain the air in the air chamber 12 at a high temperature. The high temperature water in the pond 1 evaporates and is carried by the high temperature air and rises to the cooling chamber 13. Cooling room 13
Because it is cut off from sunlight by the bulkhead 11 and cooled by low-temperature make-up seawater from the make-up water pipe 17, a pressure difference is created between it and the air chamber 12, and the pressure is always lower than that on the air chamber 12 side. There is. Therefore, the high-temperature, high-humidity air on the surface of the pond 1 always flows to the cooling chamber 13 side, condenses on the surface of the heat exchanger centered on the cooling pipe I6, releases moisture, and then returns to the air chamber 12. . This air receives solar energy in the air chamber 12 and is heated, so the relative humidity decreases, that is, it becomes dry air and flows over the surface of the light receiving surface 20, so even when the outside temperature is low, condensation on the light receiving surface 20 will not occur. do not have.

In this way, the driving force for recirculating the air in the upper structure 10 is the pressure difference between the air chamber 12 and the cooling chamber 13.
In principle, no special external power is required, but if the temperature of the make-up seawater is high, it may not be possible to obtain the pressure difference necessary for reflux, so it is more effective to provide a small fan 18. Since this fan 18 is used to direct the circulation, it requires only a very small amount of power.

The water cooled and condensed in the cooling chamber 13 flows on the surface of the cooling pipe 16, is collected in the water collecting tray 3, and is taken out to the outside.

Further, the supplementary seawater is sufficiently preheated by exchanging heat with the high temperature and high humidity air in the cooling chamber 13, and is then supplied to the pond 1. Because of this sufficient residual heat, it is important that the lower header 15 of the heat exchanger is immersed in the water in the water collection tray 3.

If the surface of the partition wall 11 is coated with a black absorption film, the air chamber 1
2. Contributes to the rise in air temperature. However, if the partition wall 11 is made of a reflective surface such as a mirror or aluminum, and attention is paid to the increase in water temperature of the pond 1 so that as much sunlight as possible is absorbed by the water of the pond 1, efficiency can be further improved.

It is effective to paste a black sheet 19 or the like on the bottom of the pond 1, but it is not always necessary. The depth of pond 1 is
Due to the underwater penetration characteristics of sunlight, it is meaningless to make the depth too deep, for example, 2 m or less is sufficient. Since the water in the pond 1 is evaporated to concentrate its salt content, it is continuously or intermittently blown to the outside and discarded. Since this blow water is highly concentrated salt water (brine), it can also be used as a raw material for salt production.

It is desirable that the pH (hydrogen ion index) of the water in the pond 1 be maintained at about 5 to 6 using hydrochloric acid, copper sulfate, etc. to prevent the transparency from being impaired due to the growth of bacteria.

The light-receiving surface 20 may be made of any transparent material such as vinyl or tent, but glass is most preferable in consideration of sunlight transmittance and deterioration.

Furthermore, the heat exchanger placed in the cooling chamber 13 is not necessarily limited to the configuration shown in the drawings. Any generally known form of heat exchanger is applicable. Of course, it can be made of multiple layers instead of just one layer.

In high latitude regions, the light receiving surface 20 is installed facing south, but in low latitude regions, the light receiving surface 20 is installed on both sides as shown in Figure 2.
A configuration in which 0 is provided is also effective. In this case as well, the light receiving surface 20
should face south and north respectively (with the longitudinal direction facing east-west).

Figure 3 adds some power to the basic plan of Figure 1.

By forcedly circulating the air within the upper structure 10,
This is another example in which the water production capacity was improved.

That is, as shown in FIG. 3(c), the fan 18
By forcibly circulating air from the air chamber 12 to the cooling chamber 13, evaporation by forced convection on the surface of the pond 1 is promoted.

With this structure, the air inside the upper structure 10 and the surface of the pond 1 reach a high temperature of 60 to 90°C,
It becomes possible to realize a water production system that utilizes solar heat with a heat collection efficiency of over 50%.

〔Effect of the invention〕

With the configuration of the present invention, there is no adhesion of water droplets on the light receiving surface on either the inner or outer surface that would obstruct the transmission of sunlight, and solar energy can be used with high efficiency to heat seawater, etc. to extremely high temperatures. Since the air is circulated using natural convection due to the pressure difference created between the air chamber and the cooling chamber, no power is required at all, but even if it is, it requires very little power and requires almost no maintenance. It is possible to provide a water generation device that is extremely lightweight, low cost, and has a simple structure that requires almost no running cost because it is unnecessary, and that can produce inexpensive water.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are a side view and a front view showing one embodiment of the freshwater generating device according to the present invention, and FIG. 2 is a side view showing another embodiment of the freshwater generating device according to the present invention. , FIGS. 3(a), 3(b), and 3(c) are a side view, a front view, and a plan view showing still another embodiment of the water launching device according to the present invention, and FIG. 4 shows a conventional water generating device. FIG. 1...Pond, 2...Tent, 3...Water collection tray, 1
0. Upper structure, 11... Partition wall, 12... Air chamber,
13...Cooling chamber, 18...Fan, 2o...Light receiving surface. Agent Patent Attorney Noriyuki Chika Yudo Hirofumi Mimata Figure 4

Claims (3)

[Claims] (1) A pond filled with seawater, etc., an upper structure that covers the pond with a transparent enclosure and partitions the interior with partition walls to form an air chamber and a cooling chamber, and a heat exchanger installed in the cooling chamber. A water production device consisting of an exchanger and a water collection tray for collecting water condensed by the heat exchanger. (2) The fresh water generating device according to claim (1), further comprising a fan for circulating air inside the upper structure. (3) The water generating device according to claim (1), wherein a part of the heat exchanger is immersed in the water collection tray.