JP2003080239A - Method for producing fresh water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing fresh water from seawater environmentally friendly by utilizing both the sunlight energy in coastal areas of the sea or salt lakes and the cooling capacity of the sea or the salt lakes. SOLUTION: This method uses a fresh water producing apparatus. The apparatus consists mainly of a steam generating unit 2 which is provided with a shell unit 2a constituting a body and a sunlight receiving unit 2b and in which the outer peripheral part of the shell unit 2a is covered by a thermally insulating material 8 and which internally has a salt water storage section and a steam generating space, a dew condensation generating unit 3 which is immersed into the water for moving and cooling the steam to cause dew condensation, and a communicative connection unit 4 which has a communicate connection cavity for moving the steam between the steam generating unit 2 and the dew condensation generating unit 3 and the outer peripheral part is covered with the thermally insulating material 8. The apparatus is also provided with a salt water feeder 5 to the steam generating unit 2 and a fresh water recovering device 6 from the dew condemnation generating unit 3, and also with a member 7 for suppressing convection and waving of the salt water near the water surface of the salt water storage section of the steam generating unit 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the use of sunlight to generate steam from salt water on the coast or on the water such as the sea or salt lakes, and the amount of water vapor allowed in the air changes depending on the temperature. In the low temperature environment of water such as the sea or salt lake, by utilizing the characteristic that steam exceeding the allowable amount condenses and liquefies and the characteristic that the steam independently moves from the high pressure side to the low pressure side according to the partial pressure of steam in the air The present invention relates to a fresh water production method for producing fresh water not only by collecting water vapor as dew condensation water but by moving water vapor from a water vapor generation site to a dew condensation generation site without using power as much as possible.

[0002]

2. Description of the Related Art In daily life in coastal areas such as the sea or salt lakes where there is little rainfall, a large amount of salt water exists in the vicinity, but it is not easy to separate salt from salt water.
In many cases, it is difficult to secure fresh water for drinking water, etc., except for areas where it is possible to receive fresh water. There are roughly classified methods for desalinizing salt water, such as evaporation method, reverse osmosis method, and electrodialysis method. Currently, the evaporation method is boiling salt water to generate steam and cool it. A relatively large number of methods are used to produce fresh water, or a reverse osmosis method, in which a reverse osmosis membrane is used to apply pressure to separate fresh water from salt water. But,
These methods require a large amount of combustion energy or electric power, and not only increase the cause of deterioration of the global environment due to useless atmospheric heating and exhaust of combustion gas into the atmosphere in the combustion process including power generation. There is also a research report that the reserve energy resources such as oil and natural gas will be exhausted during the 21st century, and waste is not preferable from the aspect of exhaustion of reserve energy resources.

For this reason, some methods have already been attempted to produce fresh water from salt water using sunlight in consideration of energy saving and environment. These methods are almost the same in generating water vapor using sunlight, but a method for cooling the generated water vapor using a mechanical cooling device and a mechanical device for generating the water vapor are provided. There are a method of using it to bring the inside closer to a vacuum to increase the generation efficiency of water vapor, and a method of cooling the water vapor generated by utilizing the vaporization action when water is sprayed without using much electric power. However, the method of cooling using a mechanical device and the method of increasing the efficiency of generating steam by bringing the inside closer to a vacuum increase the amount of fresh water that can be obtained, but require a large amount of electric power or the like. On the other hand, in the method of cooling the steam generated by using the vaporization effect when water is sprayed, the air is cooled at the same time as the steam. The newly supplied outside air needs to be warmed, and the use of solar energy is wasted, which is not efficient. From this, it seems that many problems still remain in the method for producing these fresh waters. Therefore, it is desired to propose a method for obtaining fresh water from environmentally friendly salt water without wasting the limited energy resources such as oil and natural gas.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned conventional techniques, and reserves of oil and natural gas in the coastal areas such as the sea or salt lakes where the rainfall is small. Uses solar energy, which is a natural energy that is kind to the environment, and the cooling capacity of water such as the sea or salt lake, without wasting energy resources, and at the same time wastes the use of solar energy in the cooling process from steam generation. It is an object of the present invention to provide a fresh water production method for producing fresh water from salt water that is not allowed to do so.

[0005]

In order to achieve the above-mentioned object, a method for producing fresh water according to the present invention is such that a main part is a part which generates water vapor and a shell part which constitutes the body of the part and the reception of sunlight. And a steam generating part having an outer peripheral portion of the shell part covered with a heat insulating material and having a salt water storage part and a steam generating space inside, and moving and cooling the steam generated in the steam generating part. Condensation generation part penetrated into water to cause condensation phenomenon and a communication cavity for moving water vapor between the steam generation part and the condensation generation part, and the outer peripheral part up to near the water surface is a heat insulating material. It consists of a covered communication part, and a salt water supply device for supplementing salt water to the steam generation part and a fresh water recovery device for collecting dew condensation water from the dew condensation generation part are attached. By using a fresh water production device characterized by the above, on the coast or on the water of the sea or salt lake, etc., the water vapor is generated from the salt water by utilizing the solar energy, and the amount of water vapor allowed in the air changes depending on the temperature. In a low-temperature environment in water such as the sea or salt lakes, the characteristics of steam condensing and liquefying steam exceeding the allowable amount and the characteristics of steam moving independently from the high pressure side to the low pressure side according to the partial pressure of steam in the air are used. In addition to collecting water vapor as condensed water, the water vapor is moved from the water vapor generation site to the dew condensation generation site without using power as much as possible to produce fresh water. It suppresses wasteful emission and suppresses wasteful energy transfer between it and the outside air by containing the internal air. A fresh water producing apparatus characterized in that a convection and ripple suppression member of a mat-like or sponge-like shape for suppressing convection and ripple of salt water is arranged near the water surface of the salt water reservoir at It is used.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a fresh water producing apparatus used in the fresh water producing method of the present invention will be described below with reference to the drawings. The fresh water producing apparatus used in the present invention will be described below unless the gist thereof is exceeded. It is not limited to. FIG. 1 is a schematic cross-sectional view showing an example in which a water vapor generation site of a fresh water production apparatus used in the fresh water production method of the present invention is installed on a land portion, and FIG. 2 is a view showing a communication site and a dew formation site of the example of FIG. 3 is a schematic cross-sectional view showing a cross section of FIG. FIG. 3 is a schematic cross-sectional view showing an example in which the steam generation part of the fresh water producing apparatus of the present invention is floated on water, and FIG. 4 is a schematic cross-sectional view showing another cross section of the example of FIG. Further, FIG. 5 is a schematic cross-sectional view showing an example in which a convection and ripple suppressing member near the water surface is arranged near the water surface in the salt water storage portion of the steam generation portion of the example shown in FIG. 1, and FIG. FIG. 4 is a schematic cross-sectional view showing an example in which a convection and ripple suppression member near the water surface is arranged near the water surface of a salt water reservoir of the steam generation site of the example shown in FIG. 3. FIG. 7 is a cross-sectional view showing an example in which a protrusion portion for promoting heat exchange is attached to the inner surface and the outer surface of the shell portion where the dew condensation occurs.

As shown in FIGS. 1 to 4, in the fresh water producing apparatus 1 used in the fresh water producing method of the present invention, a main part is a part for generating water vapor, and a shell part 2a which constitutes the body of the part and solar light. A water vapor generating portion 2 having a light receiving portion 2b, an outer peripheral portion of the shell portion 2a covered with a heat insulating material 8 and a salt water storing portion and a water vapor generating space inside, and water vapor generated in the water vapor generating portion 2. A water surface having a dew condensation generating part 3 penetrating into water for moving and cooling to generate a dew condensation phenomenon, and a communication cavity for moving water vapor between the water vapor generating part 2 and the dew condensation generating part 3. In order to collect the dew condensation water from the salt water supply device 5 for supplying salt water to the steam generation part 2 and the dew condensation generation part 3 and the communication part 4 whose outer peripheral portion is covered with the heat insulating material 8 Is characterized in that fresh water recovery device 6 is attached. The water vapor generation site 2 is shown in FIG.
It can be installed on the land as shown in FIGS. 2 to 2, or on the water as shown in FIGS. Moreover, when installing on the water, the fresh water producing apparatus 1 can be incorporated in a part of the ship. As an added feature, a convection and ripple suppressing member 7 having a mat-like or spongy body-like shape for suppressing the convection and ripple of the salt water is disposed near the water surface of the salt water reservoir of the steam generation site 2. It is characterized by being set up. In addition, 9 in FIGS. 1-2 and 5 is a land part. The details of each part will be described below.

The scale of the steam generating portion 2 is appropriately set in consideration of the conditions and is not limited. The shell portion 2a such as the bottom portion and the side wall portion is made of a material having high shape retention strength, watertightness, and weather resistance, such as metal, hard plastic, or a composite material thereof. Further, it is preferable that the inner surface has a color tone that suppresses light reflection in order to enhance the light receiving efficiency. And, the material of the sunlight receiving portion 2b is
For example, it is made of a material such as glass or an acrylic plate that is capable of transmitting hard and transparent sunlight and has high shape retention strength, watertightness, and weather resistance, and has a sunlight-transmitting performance similar to that of glass. Used. Further, the water depth of the salt water storage portion is appropriately set in consideration of the efficiency of steam generation and control of the stored water amount from the received heat and the stored water amount, and is approximately 20 mm to 50 mm.
The size is appropriately set with a dimension in the range of about 0 mm. The height of the water vapor generation space is appropriately set in consideration of the balance between the water vapor generation capacity of the water vapor generation portion 2 and the water vapor condensation capacity of the dew condensation generation portion 3, but is approximately 200 mm to 2000 mm.
The size is appropriately set with a size in the range of about mm.

In the dew condensation-generating part 3, the shell part 3a is made of material,
For example, it is made of a material such as iron, stainless steel, aluminum, or copper, which has good thermal conductivity and has high shape retention strength, weather resistance, and water pressure resistance, such as metal or metal composite material. Regarding the internal space dimension and the thickness of the shell portion, it is preferable that the internal space dimension is large and the thickness of the shell portion is thin in order to enhance the dew condensation generating ability of the dew condensation generating portion 3. The shape is not limited as long as it is related to the generating ability and the water pressure resistance and the efficiency of heat exchange with external salt water in the condensation of steam are taken into consideration, and the shape of the invention can be achieved. In addition, when there is a possibility that a floating phenomenon due to the buoyancy of the internal space of the dew condensation occurrence part 3 may occur and cause inconvenience, it is preferable to attach a weight or an anchor or the like as appropriate to solve the problem. It is not limited as long as the purpose can be achieved. Then, as shown in FIG. 7, a thin flat plate-like projection portion 3b is formed on the inner surface and the outer surface of the shell portion 3a for promoting heat exchange in condensation of water vapor.
It is preferable to add the above because it is effective and contributes to the improvement of the water pressure resistance performance of the shell portion 3a. The material of the protruding portion 3b is preferably a material having good thermal conductivity similar to that of the shell portion 3a, and the shape and the number of attachments and the method of fixing to the shell portion 3a depend on the nature of the material used and the effect of heat exchange. It is appropriately set in consideration and is not limited.

The internal space dimension of the communicating portion 4 is appropriately set in consideration of the setting of the specifications of the steam generating portion 2 and the condensation generating portion 3 and the required length of the communicating portion 4, and the shell portion 4a is The material is made of a material having high shape retention strength, airtightness and weather resistance such as metal or hard plastic or a composite material thereof, and the thickness thereof is set to a dimension capable of ensuring the shape retention strength. Further, in order to suppress the air convection between the steam generation part 2 and the dew condensation generation part 3 in the communication part 4, a cloth-like or cotton-like member capable of suppressing the air convection without inhibiting the movement of the steam may be arranged. However, the moisture permeability of the member is preferably a member having a numerical value of at least 20 as a moisture permeability coefficient.

The salt water supply device 5 is for supplying water.
It is equipped with a water supply pump, a connecting pipe, a power source, etc., and additionally, a water supply control mechanism, a water supply tank, etc. are appropriately added and incorporated. The equipment and members used in the salt water supply device 5 can be selected from products currently used for similar purposes in consideration of requirements such as weather resistance, and the specifications thereof can be appropriately changed according to requirements. Is set.

The fresh water recovery device 6 is provided for absorbing water.
It is equipped with a water absorption pump, a connecting pipe, a water storage tank, a power source, and the like, and additionally, a water supply control mechanism, a water supply tank, and the like are appropriately added and incorporated. The equipment and members used in the fresh water recovery device 6 can be selected from products currently used for similar applications in consideration of requirements such as weather resistance, and their specifications are appropriately set according to requirements. It

The convection and ripple suppressing member 7 is shown in FIGS.
As shown in, the upper surface is disposed in a wet state in the vicinity of the water surface of the salt water storage part, and the mat-shaped material is, for example, glass fiber, plastic fiber, mineral fiber, carbon fiber, or the like processed from a fiber-based material and For the sponge body, for example, a foamed material of open cells of plastic or a mineral material processed into a sponge body is considered, but a metal plate processed into a fine lattice shape can also be used, near the water surface of salt water. And convection between the lower part and the lower part can be suppressed, and a function such as a capillary phenomenon can be exerted to move the salt water from the lower part to the upper surface of the suppressing member 7 so that the upper surface can be kept in a wet state and deteriorated to salt water. Any material that is difficult and has weather resistance can be used, and its shape and arrangement method are not limited.

As the material of the heat insulating material 8, for example, resin foamed heat insulating material such as polyethylene, polystyrene, polypropylene, polyurethane, etc. and fiber type heat insulating material such as glass wool, rock wool, etc. can be considered, but it is also used near the water surface. Therefore, the resin-based foamed heat insulating material having closed cells is preferable, and the thickness of the heat insulating material 8 is determined in consideration of the heat insulating performance required for each portion arranged to achieve the object of the present invention and the heat insulating performance of the heat insulating material to be used. And set appropriately. Further, it is preferable to coat the outer surface with a metal or a hard plastic material or the like in consideration of maintaining the heat insulating performance of the heat insulating material 8 and weather resistance.

[0015]

According to the present invention, in the coastal area such as the sea or salt lake in a region where the amount of rainfall is small, the reserve energy resources such as oil and natural gas are not wasted, and the exhaust gas such as carbon dioxide gas is generated. It is possible to provide a fresh water production method for producing fresh water from salt water by using natural energy that is also environmentally friendly, which utilizes the unprecedented solar energy and the cooling capacity in water such as the sea or salt lake, Not only can it contribute as a means to secure fresh water, which is indispensable for daily life, but it can also contribute to the conservation of the global environment. Further, the simplified fresh water producing apparatus used in the present invention can be used for securing fresh water at leisure on a yacht or on an uninhabited island, and salt water that has generated steam has a high salt content. If it is used, natural salt can be easily produced, which can contribute to the possibility of establishing a low-cost salt production business as well.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example in which a steam generation portion of a fresh water producing apparatus used in the fresh water producing method of the present invention is installed on a land portion.

FIG. 2 is a schematic cross-sectional view showing another cross-section of the communication part and the dew condensation generation part of the example of FIG.

FIG. 3 is a schematic cross-sectional view showing an example in which a steam generation site of a fresh water producing apparatus used in the present invention is floated on water.

4 is a schematic cross-sectional view showing another cross-section of the example of FIG.

FIG. 5 is a schematic cross-sectional view showing an example in which a convection and ripple suppression member near the water surface is arranged near the water surface in the salt water reservoir of the steam generation site in the example shown in FIG.

FIG. 6 is a schematic cross-sectional view showing an example in which a convection and ripple suppression member near the water surface is arranged near the water surface in the salt water reservoir of the steam generation site in the example shown in FIG.

FIG. 7 is a cross-sectional view showing an example in which a protrusion portion for promoting heat exchange is attached to the inner surface and the outer surface of the shell portion where the dew condensation occurs.

[Explanation of symbols]

1; Fresh water producing apparatus used in the fresh water producing method of the present invention 2; Water vapor generation site 2a; shell part 2b: sunlight receiving area 3; Condensation occurrence site 3a; shell part 3b; thin flat plate-like protrusions for promoting heat exchange 4; Communication site 4a; shell part 5; Salt water supply system 6; Fresh water recovery device 7; Convection and ripple suppression member 8; heat insulating material 9; Land area

Claims (2)

[Claims] 1. An apparatus for producing fresh water from salt water by utilizing sunlight on the coast or on the water of a sea, a salt lake, or the like, the main part of which is a shell that constitutes a skeleton at the site where steam is generated. A steam generating part having a part and a light receiving part of sunlight and an outer peripheral part of the shell part is covered with a heat insulating material and has a salt water storage part and a steam generating space inside,
Condensation occurrence site penetrated into water for moving and cooling the steam generated at the water vapor generation site to generate a dew condensation phenomenon, and for causing water vapor to move between the water vapor generation site and the dew condensation occurrence site It consists of a communication part that has a communication cavity and the outer periphery up to the vicinity of the water surface is covered with a heat insulating material, and a salt water supply device for replenishing salt water to the steam generation part and a condensed water recovery part from the condensation generation part. A fresh water production method characterized in that a fresh water production apparatus is used, which is equipped with a fresh water recovery apparatus. 2. A convection and ripple suppression member having a mat-like or spongy body-like shape for suppressing convection and ripple of salt water near the water surface of the salt water reservoir of the steam generation site according to claim 1. A fresh water producing method characterized in that a fresh water producing apparatus characterized by being provided is used.