JP2010269212A - Seawater desalination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seawater desalination apparatus which effectively heats seawater by solar light to obtain a large amount of steam. <P>SOLUTION: A synthetic oil H in a heating vessel 2 is heated by solar light L, the heated synthetic oil H is circulated to a heating part 14, seawater A in a steam generation part 16 is heated by the heating part 14, and therefore the seawater A is effectively heated and a large amount of steam B is obtained. Then, as the heating part 14 circulating the synthetic oil H is arranged on the ground, a steam generation part 16 and a condenser 19 are also arranged at lower positions and the circulation of the seawater A is easy. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seawater desalination apparatus using solar energy.

  An evaporation method is known as a method for desalinating seawater. In the past, boilers that burned heavy oil were used as the heat source for evaporation, but in recent years solar energy has been used because of the high fuel cost and the large amount of carbon dioxide that causes global warming. A proposed seawater desalination system has been proposed.

  This type of seawater desalination device has a structure in which seawater is stored inside a transparent evaporation tank, a hollow part is formed in the upper part of the seawater, and sunlight is concentrated on a core rod held in the hollow part. It has become. Sunlight is reflected by a mirror and applied to the core rod, and the core rod heated by sunlight warms the air in the hollow portion, thereby evaporating from the seawater surface. Water vapor from the surface of the seawater is cooled to become fresh water and stored in a water storage tank (see, for example, Patent Document 1).

JP 2008-86907 A

  However, in such a conventional technique, the core rod is heated by sunlight, the air is heated by the heated core rod, and the structure promotes evaporation from the seawater surface through the heated air. The amount of steam obtained is not sufficient.

  The present invention has been made paying attention to such a conventional technique, and provides a seawater desalination apparatus that can effectively heat seawater with sunlight and obtain a large amount of steam. .

  The invention according to claim 1 is a plurality of heating containers installed at a predetermined height and holding a heating liquid, and a plurality of heating containers installed on the ground around the heating container and reflecting sunlight toward at least the bottom surface of the heating container. A heliostat, a heating part in which the heating liquid from the heating container is circulated at a position close to the ground, a steam generation part for heating the seawater from the heat of the heating part to generate steam, and the cooling liquid is circulated to form the steam It is characterized by comprising a condenser for condensing the steam from the generator and a fresh water tank for storing fresh water condensed by the condenser.

  The invention according to claim 2 is characterized in that the heating liquid is a synthetic oil excellent in heat resistance.

  The invention described in claim 3 is characterized in that the cooling liquid is seawater circulated from the sea.

  The invention described in claim 4 is characterized in that the cooling liquid is cold water circulated from a cold water circulator.

  The invention according to claim 5 is characterized in that the seawater that has passed through the condenser is injected into the steam generating section.

  According to the first aspect of the present invention, the heating liquid in the heating container is heated by sunlight, the heated heating liquid is circulated to the heating unit, and the seawater is heated by the heating unit, so that heating is performed via air. Compared with the case, seawater can be heated effectively and a large amount of steam can be obtained. If a large amount of steam is generated, it can be cooled to obtain a large amount of fresh water. Moreover, since the heating part which circulates a heating liquid can be set to arbitrary positions, the seawater can be drawn easily by setting the heating part at a position convenient for heating seawater.

  According to invention of Claim 2, since a heating liquid is a synthetic oil excellent in heat resistance, the circulation to a heating part is smooth.

  According to the third aspect of the invention, since cold seawater circulated from the sea is used as the cooling liquid, less energy is required to condense the steam.

  According to the invention described in claim 4, since the cold water circulated from the cold water circulator is used as the cooling liquid, it is possible to condense the steam effectively, compared with the case where seawater is used as the cooling liquid. Even with the amount of steam, a larger amount of fresh water can be obtained.

  According to invention of Claim 5, in order to inject | pour the seawater which passed the capacitor | condenser into a steam generation part, the temperature of the inject | poured seawater is raised to some extent by heat exchange with a steam, and the thermal efficiency of the seawater desalination apparatus whole Can be increased.

Schematic which shows the seawater desalination apparatus which concerns on 1st Embodiment of this invention. The top view which shows a seawater desalination apparatus. The perspective view which shows a heliostat. Schematic which shows the seawater desalination apparatus which concerns on 2nd Embodiment of this invention.

(First embodiment)
1-3 is a figure which shows 1st Embodiment of this invention. In the center of the seawater desalination apparatus according to this embodiment, four towers 1 having a predetermined height (about 10 m) are erected. A metal heating container 2 is installed on the top of the tower 1.

  The heating container 2 basically has a square hollow structure, and the bottom surface 3 has a curved surface that protrudes inward. The bottom surface 3 may be a flat surface or a curved surface convex outward. A heat-resistant black paint is applied to the bottom surface 3.

  A plurality of heliostats 4 that always reflect the sunlight L toward the bottom surface 3 of the heating container 2 while tracking the sun S are installed on the ground around the heating container 2. As shown in FIG. 2, a plurality of heliostats 4 are installed in a radial pattern centering on the heating container 2 except for the south side of the heating container 2.

  As shown in FIG. 3, each heliostat 4 has a structure in which a reflecting mirror 7 is provided on the top of a column 6 erected on a base portion 5. The reflection mirror 7 is composed of a large number of small mirrors, and has a concave shape as a whole. Therefore, the sunlight L that is substantially parallel light is reflected by the reflection mirror 7 to become sunlight L that is condensed toward the target (bottom surface 3). The reflection mirror 7 is rotatable with respect to the top of the column 6 in an altitude direction and an azimuth direction. The reflection mirror 7 tracks the sun S, rotates approximately by half of the moving angle of the sunlight L, and always reflects the sunlight L in the same direction. Such a control of the reflection mirror 7 may be performed by a feedback method using an optical sensor, or may be performed by a computer control method.

  A synthetic oil H as a heating medium is held inside the heating container 2. Synthetic oil H is a liquid medium having heat resistance whose viscosity does not change up to about 400 degrees. The synthetic oil H in the heating container 2 is circulated to the heating unit 14 installed on the ground by a pump 42 provided on one side through two circulation pipes 40 and 41 on the outlet side and the inlet side. The heating unit 14 has a square flat container shape and has a certain size.

  On the heating unit 14, a steam generation unit 16 having the same area as the heating unit 14 is formed in order to ensure an evaporation area in an adjacent state. The steam generation part 16 is basically a sealed box shape, and seawater A is held inside. The steam generation unit 16 includes an injection pipe 8 and a drain pipe 9, both of which are provided with valves 10 and 11. The valve 11 on the drain pipe 9 side is normally closed, and when the seawater A reaches the valve 11, the seawater A is forcibly discharged to the height of the valve 11.

  A salinity sensor 12 is provided above the drain side valve 11. The salinity sensor 12 floats on the surface of the seawater A. Since the position on the surface of the seawater A changes depending on the salinity concentration of the seawater A, the buoyancy ( It is determined that the salt concentration is high), and a signal is output to the valve 10 on the injection side, and the seawater A is forcibly injected into the heating vessel 2 from the injection pipe 8.

  A space 13 is formed in the upper part of the seawater A inside the steam generator 16. This space portion 13 is a space in which the steam B obtained by evaporating the water of the seawater A is accumulated.

  In this space portion 13, a meandering tube-shaped capacitor 19 is formed vertically and horizontally almost over the range of the space portion 13. On the lower side of the condenser 19, a saucer-like fresh water tank 15 for storing fresh water C is formed with the steam B introduction port 43 left. The bottom surface of the fresh water tank 15 is inclined, and a water intake port 44 that can be opened and closed is formed at a low position thereof.

  An exhaust pipe 17 is formed on the wall portion of the space portion 13 opposite to the introduction port 43. A fan 18 is provided at the tip of the exhaust pipe 17 so that the air in the space 13 is discharged to the outside.

  An inlet pipe 20 is connected to one end of the capacitor 19, and a discharge pipe 21 is connected to the other end. The leading end of the introduction pipe 20 is installed in the sea 22, and the seawater A can be introduced into the condenser 19 through the filter 24 by the pump 23. The tip of the discharge pipe 21 also protrudes toward the sea 22, and the seawater A that has passed through the condenser 19 can be returned to the sea 22.

  A confluence pipe 25 is provided in the middle of the discharge pipe 21, and the drain pipe 9 of the steam generation section 16 is connected. Seawater a having a high salinity concentration discharged from the steam generation section 16 is passed through the condenser 19. You can return to sea 22 with A.

  Furthermore, the end on the opposite side of the injection pipe 8 that injects the seawater A into the steam generation section 16 is connected to a position before the junction pipe 25 of the discharge pipe 21. Therefore, the seawater A injected into the steam generation unit 16 has passed through the condenser 19.

  In addition, although the heating part 14, the steam generation part 16, etc. are illustrated in FIG.1 and FIG.2 as being installed in the position near the south side of the heating container 2, in reality, the heliostat 4 is connected to the heliostat 4. In order not to disturb the incident light of the sunlight L, it is installed to some extent on the south side. Accordingly, the circulation pipes 40 and 41 are also formed longer than the illustrated state.

  Next, the operation of this embodiment will be described.

  Seawater A is introduced into the condenser 19 from the introduction pipe 20 and circulated. The seawater A that has passed through the condenser 19 is continuously returned from the discharge pipe 21 to the sea 22, and the condenser 19 is always filled with the cold seawater A.

  Part of the seawater A that passes through the condenser 19 and flows in the discharge pipe 21 is introduced into the steam generation section 16 through the injection pipe 8. First, seawater A is introduced to the position of the valve 11 on the discharge side.

  Next, since the synthetic oil H is held in the heating container 2 and the heating unit 14 while being circulated between them, the sunlight L is condensed toward the bottom surface 3 of the heating container 2 by the heliostat 4. Sunlight L from the heliostat 4 is dispersed so as to strike the bottom surface 3 evenly. This is because the thermal efficiency is better when the entire bottom surface 3 is heated than when a part of the bottom surface 3 is partially heated. Since the bottom surface 3 is curved, the angle between the bottom surface 3 and the sunlight L is increased, and the sunlight L is reliably absorbed by the bottom surface 3. Further, the black coating on the bottom surface 3 improves the absorption of sunlight L. Thus, the sunlight L is efficiently converted into heat at the bottom surface 3 of the heating container 2.

  Since the bottom surface 3 becomes high temperature, the synthetic oil H in contact with the bottom surface 3 is also heated, and all the synthetic oil H in the heating container 2 and the heating unit 14 becomes high temperature. Since the viscosity of the synthetic oil H does not change even when the temperature becomes high (about 400 degrees), the circulation from the heating container 2 to the heating unit 14 is smooth.

  When the synthetic oil H reaches a high temperature, the seawater A in the steam generation unit 16 in contact with the heating unit 14 is heated from the bottom surface. When the temperature of the heating unit 14 is high, the seawater A boils and steam B is generated not only from the surface of the seawater A but also from the entire seawater A. Since the bottom surface of the steam generator 16 is heated, heat is easily transmitted to the entire seawater A by convection, and a large amount of steam B can be generated.

  Further, since the space portion 13 of the steam generating portion 16 is sucked by the fan 18 of the exhaust pipe 17, the air pressure in the space portion 13 is slightly lower than the atmospheric pressure. Therefore, the water of the seawater A in the steam generation part 16 is in a state where it tends to evaporate.

  The generated steam B is guided from the inlet 43 to the condenser 19 side. As described above, since the air is sucked by the fan 18 of the exhaust pipe 17 from the opposite side of the introduction port 43, the movement of the steam B from the introduction port 43 toward the condenser 19 side is promoted.

  When the steam B comes into contact with the condenser 19, it is heat-exchanged there and condensed to become fresh water (distilled water) C. The fresh water C condensed by the contact with the condenser 19 falls and is stored in the fresh water tank 15 as it is.

  The seawater A in the steam generating unit 16 has a salt concentration that is increased by evaporating water. However, when the salt concentration is higher than a preset concentration, the salt sensor 12 detects and the valve 10 of the injection pipe 8 is detected. , And fresh seawater A just passed through the condenser 19 from the discharge pipe 21 is injected into the steam generating section 16. Since the seawater A injected into the steam generator 16 is relatively warm by heat exchange with the steam B in the condenser 19, the seawater A is evaporated with less heat energy even after being introduced into the steam generator 16. And heat efficiency is good.

  The introduction of fresh seawater A into the steam generator 16 is performed until the salt concentration of the seawater A in the steam generator 16 reaches a predetermined concentration. In this process, high-concentration seawater a that overflows the height of the discharge-side valve 11 is forcibly discharged from the drain pipe 9 by the valve 11. The forcedly discharged high-concentration sea water a joins the drain pipe 21 via the junction pipe 25 and the discharge pipe 21, and is returned to the sea 22 together with the sea water A that has passed through the condenser 19.

  As described above, according to this embodiment, the synthetic oil H in the heating container 2 is heated by the sunlight L, the heated synthetic oil H is circulated to the heating unit 14, and the steam generating unit is heated by the heating unit 14. Since the seawater A in 16 is heated, the seawater A can be effectively heated and a large amount of steam B can be obtained. If a large amount of steam B is generated, it can be cooled to obtain a large amount of fresh water C. Further, since the heating unit 14 that circulates the synthetic oil H is installed on the ground, the steam generation unit 16 and the condenser 19 are also in a low position, and the seawater A can be easily routed.

  Moreover, since the heat energy for generating the steam B is obtained from the sunlight L and the cooling energy for condensing the steam B is obtained from the seawater A from the sea 22, it can be almost covered by natural energy. The use of energy resulting from fossil fuels requires very little, such as the power used by the pumps 23, 42, the fan 18, and the like.

(Second Embodiment)
FIG. 4 is a diagram showing a second embodiment of the present invention. This embodiment includes the same components as those in the first embodiment. Therefore, the same constituent elements are denoted by common reference numerals, and redundant description is omitted.

  In this embodiment, seawater A from the sea 22 can be directly injected into the injection pipe 26 of the steam generator 16. Further, the high-concentration seawater a from the drainage pipe 27 can also be returned directly to the sea 22.

  The introduction pipe 29 and the discharge pipe 30 of the condenser 28 are connected to a cold water circulator 31 installed on the ground. The cold water circulator 31 includes a refrigerator inside and can circulate the cold water D. Therefore, the inside of the condenser 28 is always in a state where the cold water D is circulated. The cold water D may be cooled fresh water or a liquid such as antifreeze.

  Electric power used in the cold water circulator 31 is supplied by a separately installed solar battery panel 32. A plurality of solar cell panels 32 are installed, and by receiving sunlight L, the cold water circulator 31 can generate electric power as necessary.

  According to this embodiment, since the cold water D circulated from the cold water circulator 31 is used as the cooling liquid, the steam B can be effectively condensed. That is, compared with the case where seawater A is used as a cooling liquid, a larger amount of fresh water C can be obtained with the same amount of steam. Moreover, if the electric power for the cold water circulator 31 is supplied by the solar cell panel 32, the fresh water C can be produced only by natural energy.

  In each of the above-described embodiments, the structure in which the vapor B is brought into contact with the meandering tubular condenser 19 is exemplified. The capacitor may be formed.

2 Heating vessel 3 Bottom surface 4 Heliostat 13 Space part 14 Heating part 15 Fresh water tank 16 Steam generating part 19, 28 Condenser 31 Cold water circulator 32 Solar panel A Sea water a Concentrated sea water B Steam C Fresh water D Cold water H Synthetic oil ( Heated liquid)
L Sunlight S Sun

Claims (5)

A heating container installed at a predetermined height from the ground and holding a heated liquid;
A plurality of heliostats installed on the ground around the heating container and reflecting sunlight toward at least the bottom surface of the heating container;
A heating unit in which the heating liquid from the heating container is circulated at a position close to the ground;
A steam generating section for generating steam by heating seawater from the heat of the heating section;
A condenser in which a cooling liquid is circulated to condense the vapor from the vapor generation unit;
A seawater desalination apparatus comprising: a fresh water tank for storing fresh water condensed by a condenser.   The seawater desalination apparatus according to claim 1, wherein the heating liquid is a synthetic oil having excellent heat resistance.   The seawater desalination apparatus according to claim 1 or 2, wherein the cooling liquid is seawater circulated from the sea.   The seawater desalination apparatus according to claim 1 or 2, wherein the cooling liquid is cold water circulated from a cold water circulator.   The seawater desalination apparatus according to claim 3, wherein seawater that has passed through the condenser is injected into the steam generation unit.

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