JP2000279944A - Desalting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desalting apparatus which is capable of suppressing the temperature rise of the raw water in a raw water tank and improving distillation performance. SOLUTION: The desalting apparatus which utilizes solar energy includes a solar thermal collector 10 which heats a heat medium 13 by the solar energy 11, an evaporator 20 of a pressure reduction system which includes a heat exchanger 22 and generates steam 23 from the raw water Q1 by effecting a heat exchange between the heat exchanger 22 and the raw water Q1 housed therein by using the heat medium 13 heated by the solar thermal collector 10 as a heating source, a condenser 32 which is arranged in the raw water tank 31 housing the raw water Q2, accepts the steam 23 generated in the evaporator 20 and obtains distilled water by effecting the heat exchange with the raw water Q2 and a radiator 40 which cools the raw water Q2 in the raw water tank 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desalination apparatus that obtains fresh water from raw water such as seawater, groundwater (brine) containing salt and industrial wastewater by distillation using solar energy.

[0002]

2. Description of the Related Art Recently, interest in desalination technology for seawater using solar energy has been increasing. The present applicant has also previously developed a "desalination apparatus and its operating method" using solar energy, and filed a patent application (97JP9700209).
8) The desalination apparatus includes a solar heat collector including a heat collector that collects solar energy, and raw water housed inside the heat exchanger using a heat medium heated by the solar heat collector as a heating source. A decompression evaporator for performing heat exchange between the raw water and generating water vapor from the raw water, and a raw water tank for storing the raw water, and using the heat medium heated by the solar heat collector as a heat source to exchange heat between the evaporators. The steam generated in the evaporator is supplied to a condenser in a raw water tank to obtain distilled water. This raw water tank is covered with an air barrier with good heat transfer performance with the outer surface as a heat radiator and the inner surface as a condensing portion, recovering condensed water by night heat radiation and improving the recovery efficiency of distilled water. ing.

[0003] The above desalination plant was prototyped to check its performance.
In Japan and in low-latitude dry areas with high solar radiation (Middle East)
Was tested. As a result, a predetermined capacity is obtained stably, and the unit yield (per heat collecting area) is also 1 unit.
It was confirmed that the performance was 2.5 kg / m ² or more, far exceeding the performance of a conventionally proposed solar water desalination apparatus.

[0004]

In an experiment for confirming the performance of the desalination apparatus, when the obtained operation data was analyzed, the temperature rise of the raw water in the raw water tank was as designed, but the condensing capacity ( It has been found that the improvement of the cooling capacity is important for further improving the distillation performance. In other words, it is important to improve the performance to minimize the temperature rise of the raw water in the raw water tank that is the cooling source.

[0005] The present invention has been made in view of the above points, and has as its object to provide a desalination apparatus capable of suppressing a rise in the temperature of raw water in a raw water tank and improving distillation performance.

[0006]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 is a desalination apparatus using solar energy, comprising: a solar heat collector for heating a heating medium by solar energy; A depressurization type in which a heat exchanger equipped with a heat medium heated by a solar heat collector is used as a heating source to perform heat exchange with raw water housed therein to generate steam from the raw water. An evaporator, a condenser placed in a raw water tank containing raw water, receiving a steam generated by the evaporator and performing heat exchange with the raw water to obtain distilled water, and directly or indirectly supplying raw water in the raw water tank. And a radiator for cooling.

By providing the radiator for cooling the raw water in the raw water tank as described above, the rise in the temperature of the raw water in the raw water tank is suppressed, and the distillation performance is improved.

[0008] The invention described in claim 2 is the first invention.
In the desalination apparatus according to the above, the radiator for indirectly cooling the raw water includes a heat exchanger and an external radiator arranged in the raw water tank, and the heat exchanger and the external radiator are connected by a medium passage. It is a thermosiphon type radiator that cools raw water by repeating evaporation and condensation of a medium.

As described above, the heat radiator is of the thermosiphon type which cools the raw water by repeating evaporation and condensation of the medium, thereby releasing the heat of the raw water without requiring any special power for heat radiation. be able to.

[0010] Further, the invention described in claim 3 is based on claim 2.
Wherein the medium that repeats evaporation and condensation between the heat exchanger and the radiator is water.

As described above, by providing an external radiator (using a thermosiphon), a pipe (such as seawater) connecting the external radiator and the heat exchanger disposed in the raw water tank can be provided. The use of inexpensive materials to reduce the price without using corrosion-resistant materials (when not in contact with salt water), as well as efficient and efficient selection of external radiator materials without restrictions A material having good heat conductivity such as aluminum or aluminum can be selected, and an external radiator having good heat radiation efficiency can be constructed. Here, it is of course possible to use a heat pipe in consideration of the material of the portion in contact with seawater.

The invention described in claim 4 is the first invention.
In the desalination apparatus according to any one of the above items 3 to 3, the raw water tank is disposed inside or outside the desalination apparatus in a shaded area or a place where heat input to the raw water tank is small.

The invention described in claim 5 is the first invention.
In the desalination apparatus according to any one of the above items 3 to 3, the radiator or the external radiator is installed in a shade portion inside or outside the desalination apparatus or in a place optimal for heat radiation.

As described above, since the raw water tank and the radiator are arranged in a place where sunlight does not directly hit, a place where heat input is small, and an optimal place for heat radiation, the temperature rise of the raw water in the raw water tank can be suppressed. Since the heat radiation efficiency of the radiator is improved, the temperature rise of the raw water can be further suppressed.

Further, as described above, the radiator or the external radiator is installed in the shaded area inside or outside the desalination apparatus or in a place where heat can be efficiently radiated by utilizing the sky heat radiation at night in a place optimal for heat radiation. Efficient cooling of the raw water in the raw water tank becomes possible.

The invention described in claim 6 is the first invention.
The desalination apparatus according to any one of claims 1 to 5, wherein an open / close valve is provided in a raw water passage connecting the raw water tank and the radiator or a medium passage connecting the heat exchanger and the external radiator, When the temperature of the raw water inside is lower than the temperature of the outside air, the on-off valve is closed.

As described above, the open / close valve is provided in the raw water passage connecting the raw water tank and the radiator or in the medium passage connecting the heat exchanger and the external radiator so that the temperature of the raw water in the raw water tank is lower than the outside air temperature. If the temperature is too low, closing the on-off valve can prevent heat from entering the raw water in the raw water tank from outside due to an increase in daytime temperature.

[0018] The invention according to claim 7 is a desalination apparatus utilizing solar energy, comprising a solar heat collector for heating a heat medium by solar energy, and a solar heat collector comprising a heat exchanger. The heat medium heated in the above step is used as a heat source to perform heat exchange between raw water contained in the heat exchanger and generate steam from the raw water, and a reduced pressure evaporator, which is generated in the evaporator. A condenser for condensing steam to obtain distilled water;
A heat exchanger that is disposed in a raw water tank containing raw water and exchanges heat with the raw water by passing a heat medium through a heat exchanger in an evaporator; The heat of the heat medium heated by the raw water through the exchanger is radiated outside through the heat collecting plate of the solar heat collector.

As described above, the heat of the raw water in the raw water tank is radiated through the heat collector plate of the solar heat collector at night, so that the heat of the raw water heated day and day is efficiently passed through the heat collector plate at night. Heat can be dissipated.

The invention described in claim 8 is the same as the invention described in claim 7.
In the desalination apparatus described in (1), a bypass means for bypassing the heat exchanger of the evaporator is provided, and the heat medium heated by the raw water through the heat exchanger in the raw water tank is sent to the heat collecting plate of the solar heat collector at night. It is characterized by the following.

By providing the bypass means as described above, the heat medium heated by the raw water is passed through the heat exchanger in the raw water tank at night to bypass the heat exchanger of the evaporator to the heat collecting plate of the solar heat collector. Since the heat is sent through the heat collector plate of the solar collector at night, the heat is completely reversed from the daytime heat collection cycle, and the temperature of the raw water in the raw water tank can be effectively lowered. it can.

The invention according to claim 9 is the same as the invention according to claim 7.
Alternatively, in the desalination apparatus according to claim 8, a radiator for directly or indirectly cooling the raw water in the raw water tank is provided.

As described above, the desalination apparatus according to claim 7 or 8 is provided with a radiator for directly or indirectly cooling the raw water, so that the temperature of the raw water in the raw water tank can be further effectively reduced. Can be lowered.

According to a tenth aspect of the present invention, there is provided a desalination apparatus utilizing solar energy, comprising a solar heat collector for heating a heat medium by solar energy, and a solar heat collector comprising a heat exchanger. The heat medium heated in the above step is used as a heat source to perform heat exchange between raw water contained in the heat exchanger and generate steam from the raw water, and a reduced pressure evaporator, which is generated in the evaporator. A condenser for condensing steam, the condenser being housed in a small-capacity tank, supplying a predetermined flow rate of raw water necessary for condensation of the steam as cooling water into the tank, and heating the condenser. It is characterized by discharging a quantity of raw water.

As described above, the condenser for condensing the water vapor generated in the evaporator is accommodated in the small-capacity tank, and a predetermined flow rate of raw water required for the condensation of the water vapor is supplied into the tank as cooling water. Since the same amount of heated raw water is discharged, the temperature of raw water in the raw water tank can be kept substantially constant during operation with a small supply raw water flow rate.

The invention according to claim 11 is characterized in that, in the desalination apparatus according to claim 10, the combination of the condenser and the small-capacity tank is a heat exchanger.

As described above, the combination of the condenser and the small-capacity tank is, for example, a shell-tube type heat exchanger or a plate type heat exchanger, so that the temperature of the raw water can be controlled with a smaller flow rate of the raw water. It can be kept almost constant.

According to a twelfth aspect of the present invention, in the desalination apparatus according to any one of the first to eleventh aspects, raw water heated by a condenser for condensing steam generated in the evaporator is separately separated. Means for storing the stored raw water in the provided storage tank and supplying the stored raw water to the evaporator as raw water for evaporation.

The raw water heated by the condenser that condenses the water vapor generated in the evaporator has a high water temperature. By supplying this raw water to the evaporator as raw water for evaporation, the raw water heated by the condenser is removed. Since it can be effectively used, the distillation capacity of the desalination apparatus is further improved.

According to a thirteenth aspect of the present invention, in the desalination apparatus according to any one of the first to twelfth aspects, the desalination apparatus further includes a water tank having a shallow depth of water and an open upper portion, and the opening of the water tank is closed. A basin-type solar still having a configuration covered with a translucent cover is provided, and raw water heated by a condenser that condenses water vapor generated in an evaporator in a water tank of the solar still is obtained to obtain distilled water. It is characterized by having such a configuration.

By providing a basin-type solar still as described above and storing the raw water heated by the condenser in a water tank of the solar still, to obtain distilled water,
The distillation capacity as a whole is further improved.

According to a fourteenth aspect of the present invention, in the desalination apparatus according to any one of the first to thirteenth aspects, a pool having a large area with a shallow water depth is provided, and the pool is provided with the evaporator. Raw water heated by a condenser that condenses the generated water vapor and / or raw water discharged from a water tank of the solar still is stored, and the solar water is used from the raw water to produce salt and other raw water (for example, seawater). It is characterized by recovering useful salts.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a desalination apparatus according to the first aspect of the present invention. The present desalination apparatus is configured to include a solar heat collector 10, an evaporator 20, and a radiator 40.

The solar heat collector 10 includes a heat collecting plate 12 for collecting solar energy 11 and heating a heat medium 13. Evaporator 20 comprises a can body 21, the raw water Q ₁ is housed in the can body 21. Furthermore, the heat exchanger 22 is disposed so as to can body 21 is immersed in the raw water Q _1. 31 is a raw water tank containing raw water Q ₂ therein, the opening portion of the raw water tank 31 is covered with an air shield 34, further upper surface is covered by an air shield 34 that transmits sunlight '.
Further, the condenser 32 so as to dip into the raw water Q ₂ is disposed in the raw water tank 31. In addition, the condenser 32 is arranged at the bottom of the raw water tank 31.

In the desalination apparatus having the above structure, the solar energy 11 collected by the heat collecting plate 12 of the solar heat collector 10 is used.
Heats the heat medium 13 and vaporizes the heat medium. The vaporized heat medium 13 flows into the heat exchanger 22, exchanges heat with the raw water Q ₁ in the heat exchanger 22, is condensed, and returns to the heat collecting plate 12 as a liquid heat medium.

Steam 23 is generated from the raw water Q ₁ heated by the heat medium 13 in the heat exchanger 22. In addition, can body 2
The pressure in the chamber 1 is reduced by a vacuum pump or the like (not shown), and the generation of water vapor 23 is actively performed. The steam 23 is supplied to the pipe 2
4 flows into a condenser 32 arranged in a raw water tank 31. With steam heat exchange is performed is recovered as condensed distilled water W between the condenser 32 in the steam 23 and the raw water Q _2, raw water Q ₂ is being warmed.

When the raw water Q ₂ is heated and the water temperature rises, the condensation function of the condenser 32 deteriorates. Therefore, a radiator 40 is provided here, and the raw water Q ₂ in the raw water tank 31 is circulated through the radiator 40 so that the raw water Q ₂ is circulated. releasing heat Q ₂ has the outside. Also,
The solar energy 11 that has passed through the air shield 34 ′ heats the upper layer of the raw water Q ₂ and generates water vapor 33. The water vapor 33 is condensed on the back surface of the air shield 34 ′ to become distilled water, flows down the back surface of the air shield 34 ′, is collected by the collection gutter 35, and is collected as distilled water W. The collection of the distilled water W by the collection gutter 35 is also performed during the night when much heat is dissipated from the surface of the air shield 34 '.

As described above, the raw water Q ₂ in the raw water tank 31
By providing the radiator 40 for cooling a heat of the raw water Q ₂ is the temperature rise is suppressed, condensation capacity decrease in the condenser 32 is suppressed. Especially at night by the heat released from the heat dissipation and the radiator 40 from the surface of the air shield 34 ', the raw water Q ₂ is more effectively cooled, it contributes to the daytime distillation recovery performance of the desalination apparatus. Incidentally, since the upper layer of the raw water Q ₂ of the raw water tank 31 water temperature is high, by supplying the evaporator 20 the raw water Q ₂ in this highly water temperature upper as raw water to Q ₁ for evaporation, the evaporation in evaporator 20 is efficiently Well done.

In the above example, the evaporator 20 has one stage, but may have two or more stages as shown in FIG.
In this case, the distilled water in the final stage evaporator 20-3 is supplied to the condenser 32.
To lead.

FIG. 2 is a diagram showing a configuration example of a desalination apparatus according to the second aspect of the present invention. In the figure, the parts denoted by the same reference numerals as those in FIG.
The same applies to other drawings). Fig. 1
Is different from the desalination apparatus in that the radiator includes a heat exchanger 41 disposed in the raw water tank 31 and an external radiator 42 disposed outside the raw water tank 31. The heat exchanger 41 and the external radiator 42 connected by the medium passage 43, a point is a radiator of the thermo-siphon cooling the repeated raw water Q ₂ the evaporation and condensation of the medium, the other is the same as the desalination apparatus of FIG.

As described above, the heat radiator is connected to the heat exchanger 41 and the external radiator 42 through the medium passage 43 to form a thermosiphon radiator that cools raw water by repeating evaporation and condensation of the medium. without the need for special power for heat radiation, it can release heat of the raw water Q _2.

The desalination apparatus according to the third aspect of the present invention has the same structure as the desalination apparatus shown in FIG.
The medium passing through the medium passage 43 is water. As described above,
By providing an external radiator (using a thermosiphon), the material can be used inexpensively without using a corrosion-resistant material in the pipe of the external radiator 42 and the medium passage 43 (when not in contact with salt water such as seawater). As a result, the price can be reduced. Further, the material of the external radiator 42 can be selected without restriction,
An efficient heat radiator such as copper or aluminum can be selected, and the external radiator 42 having high heat radiation efficiency can be configured. It is needless to say that a heat pipe may be used as the external radiator 42.

FIG. 3 is a diagram showing a configuration example of a desalination apparatus according to the fourth aspect of the present invention. In the present desalination apparatus, the heat collecting plate 12 of the solar heat collector 10 and the solar cell 50 are arranged at the upper part. Evaporator 20, raw water tank 31, and radiator 40
Is a place where the solar energy (sunlight) 11 does not directly hit (such as a shade generated by the heat collecting plate 12 and the solar cell 50), that is, the raw water tank 31 is placed in a place where heat input from outside is small, and the radiator 40 is provided. Is placed in a place suitable for heat dissipation. In addition, it is desirable that the solar cell 50 can cover the power required by the desalination apparatus with the obtained power.

As described above, by disposing the raw water tank 31 and the radiator 40 in a place where heat input is small such as a shade where sunlight does not directly hit or a place suitable for heat radiation, the raw water Q ₂ in the raw water tank 31 is reduced. Is suppressed, and the heat radiation efficiency of the radiator 40 is improved. 1 and 2, the raw water tank 31, the radiator 40, and the external radiator 42 are arranged in a place with little shading, little heat input, or a place suitable for heat radiation. with increasing temperature Q ₂ 'is suppressed, it is appreciated that it is possible to improve the heat radiation efficiency of the radiator 40.

FIG. 4 is a diagram showing a configuration example of a desalination apparatus according to the fifth aspect of the present invention. External radiator 42 of radiator
Is installed in the shade area inside or outside of the desalination apparatus or in a place optimal for heat radiation. Thus, the external radiator 42 inside and outside the desalination apparatus, for example by placing in a location that is efficiently radiated at night sky radiator etc., to be an efficient cooling of the raw water Q ₂ in the raw water tank 31 it can. Incidentally, as shown in FIG. 1, by setting the optimal location inside or outside the shaded portion or radiator of the radiator 40 also the desalination apparatus of the type for circulating raw water Q ₂ in the raw water tank 31 directly, for example at night Raw water Q ₂ in the raw water tank 31 using the sky heat radiation
Can be efficiently cooled.

FIG. 5 is a diagram showing a configuration example of a desalination apparatus according to the sixth aspect of the present invention. The desalination apparatus includes a medium passage 43 connecting a heat exchanger 41 of a radiator and an external radiator 42.
An open / close valve 44 is provided at night, and the open / close valve 44 is opened at night to radiate the heat of the raw water Q ₂ in the raw water tank 31 through the external radiator 42, so that the daytime outside air temperature rises and the raw water Q in the raw water tank 31 rises. _When the temperature of the valve 2 becomes lower than the outside air temperature, the on-off valve 4
Close 4

As described above, the heat exchanger 41 and the external radiator 4
An opening / closing valve 44 is provided in the medium passage 43 connecting the raw water tank 31 and the raw water tank 31 when the raw water temperature in the raw water tank 31 is lower than the outside air temperature. it is possible to prevent the heat from entering the raw water Q _2. It is also easy to automatically open and close the on-off valve 44. For example a sensor is provided for measuring the sensor and the outside air temperature to measure the temperature of the raw water Q _2, when the water temperature of the raw water Q ₂ is higher than the outside air temperature opens the on-off valve 44, when the water temperature of the raw water Q ₂ is lower than the outside air temperature What is necessary is just to control automatically so that the on-off valve 44 may be closed.

Note that, as shown in FIG.
Off valve to the radiator 40, even circulation path of the raw water in the form of circulating the raw water Q ₂ direct inner provided, if the raw water temperature of the raw water tank 31 is lower than the outside air temperature, by closing the on-off valve 44, day it is possible to prevent heat from entering the raw water Q ₂ of the raw water tank 31 from the outside by the temperature rise during.

FIG. 6 is a diagram showing the structure of a desalination apparatus according to the seventh aspect of the present invention. The desalination apparatus includes a plurality of (three in the figure) evaporators 20-1, 20-2, and 20-3.
Is disposed, and the steam 2 generated in the first evaporator 20-1
3 flows into the heat exchanger 22 disposed in the second evaporator 20-2, is condensed and collected as distilled water W, and the steam 23 generated in the second evaporator 20-2 is condensed in the third evaporator 20-2. The water flows into the heat exchanger 22 disposed in the pipe 20-3, is condensed, and is recovered as distilled water W.

In the desalination apparatus having the above structure, when the sun is shining in the daytime, the heat medium 13 heated by the heat collecting plate 12 of the solar heat collector 10 is heated by the first evaporator 20-1. The raw water Q ₁ is heated through the exchanger 22, and then returns to the heat collecting plate 12 of the solar heat collector 10 through the heat exchanger 37 disposed in the upper part of the raw water tank 31 (near the surface of the raw water Q ₂ ). It has become.

In the desalination apparatus having the above-described structure, since the heat collecting plate 12 of the solar heat collector 10 has a heat radiation function at night, heat is radiated in the raw water tank 31 using the night heat radiation function. That is, in the cycle of recovering the distilled water W in the daytime, the heat medium 13 is the heat collector plate 12 of the solar heat collector 10 → the first heat collector.
Flows through the heat exchanger 22 of the evaporator 20-1 → the heat exchanger 37 of the raw water tank 31 → the heat collecting plate 12, but at night, the heat exchanger of the raw water tank 31 is reversed, as shown by the arrow A. 37
→ heat exchanger 22 of first evaporator 20-1 → heat collecting plate 12 →
Flow heat exchanger 37, radiates heat to the raw water Q _2's.

The heat exchanger 37 has the heat collecting plate 12 at night.
Between heat release and raw water Q in raw water tank 31 _TwoRequired cooling heat
By giving the necessary heat transfer area in consideration of
Raw water Q_TwoCan be cooled by the required amount of cooling heat.

FIG. 7 is a diagram showing an example of the configuration of a desalination apparatus according to the eighth aspect of the present invention. This desalination apparatus is different from the desalination apparatus shown in FIG. 6 in that a bypass line 27 having switching valves 25 and 26 for bypassing the heat exchanger 22 of the first evaporator 20-1 is provided. It is. During the night, the switching valves 25 and 26 are switched, and the heat medium 13 is caused to flow by bypassing the heat exchanger 22 as shown by the arrow A, so that it is surely reverse to the daytime distilled water recovery cycle (heat collection cycle). The heat collecting plate 1 of the solar heat collector 10
The water temperature of the raw water Q2 can be effectively reduced by the night heat radiation to the sky of No. ₂ .

FIG. 8 is a diagram showing a configuration example of a desalination apparatus according to the ninth aspect of the present invention. The desalination apparatus for cooling the raw water Q ₂ of the raw water tank 31 to the desalination apparatus shown in FIG. 7, the arranging heat exchanger 41 into the raw water tank 31, external heat to the outer raw water tank 31 The heat exchanger 41 and the external radiator 42 are connected to each other by an on-off valve and a medium passage.

As described above, by providing the heat exchanger 41 and the external radiator 42 and cooling the raw water Q ₂ in the raw water tank 31 by heat radiation, the water temperature of the raw water Q ₂ can be more effectively lowered. . In this example provided a heat exchanger 41 and the external radiator 42, but are cooled indirectly raw water Q ₂ through a medium, raw water Q ₂ as shown in FIG. 1
The flow to the radiator 40 may be configured to directly cool the raw water Q ₂ by the radiation.

FIG. 9 is a diagram showing a configuration example of a desalination apparatus according to the tenth aspect of the present invention. The desalination apparatus includes a solar heat collector 10 that heats a heat medium 13 with solar energy.
And a condenser 32 accommodated in a small-capacity raw water tank 31. Further, a predetermined flow rate of raw water required for condensation of steam is supplied as cooling water into the small-capacity raw water tank 31 by the pump 51 during operation of the apparatus,
The same flow of raw water is flowing out.

In the desalination apparatus having the above structure, the heat medium 13 heated by the heat collecting plate 12 of the solar heat collector 10 is supplied to the evaporator 2.
The raw water Q ₁ flows into the heat exchanger 22, and returns to the heat collecting plate 12. In addition, the water vapor 2 generated in the evaporator 20
3 is condensed in a condenser 32 disposed in a raw water tank 31 and recovered as distilled water W. The outlet temperature of the raw water Q ₃ flowing around the condenser 32 to flow from the inlet temperature, the raw water Q ₃ flow rate no higher eg 5 ° C. or more operating time during the day. To use the raw water Q ₃ as a cooling source, the inlet (feed) temperature is kept to be lower, during the cooling source temperature device driver can keep substantially constant.

Further, in such a desalination apparatus using solar energy, the operation is performed only when the sun is climbing, and the amount of heat is 1 kW per unit area in the solar radiation on the ground plane.
/ M ² or less, so that the flow rate of the cooling source can be very small. This means that the supply of cooling
Even if the operation is performed in a small size, the power consumption is small. Therefore, it is possible to install a small-capacity solar cell and cover the generated power.

FIG. 10 is a view showing the structure of a desalination apparatus according to the eleventh aspect of the present invention. The present desalination apparatus differs from the desalination apparatus in FIG. 9 in that a heat exchanger 29 is used in place of the combination of the raw water tank 31 and the condenser 32 in FIG. The heat medium 13 heated by the heat collecting plate 12 of the solar heat collector 10 is supplied to the heat exchanger 22 of the evaporator 20 and returns the discharged heat medium 13 to the heat collecting plate 12.

When a shell-tube type heat exchanger is used as the heat exchanger 29, steam from the raw water generated in the evaporator 20 is supplied into the tube of the shell-tube type heat exchanger 29, and is pumped by the pump 51. is raw water Q ₃ and the heat exchanger is supplied to the tube, is condensed water W becomes recovered.
Thus the heat exchanger 29 using the steam generated from the raw water Q ₁ in evaporator 20 within a condenser for condensing a cooling source in the tube when, for example, using a shell-tube heat exchanger raw water Q By supplying ₃ and making the shell side steam and condensing side, the flow rate in the tube can be secured and the heat transfer performance can be improved, and at the same time, the shell side material is not seawater-resistant but uses general-purpose stainless steel etc. And the price can be reduced.

In the above example, the shell-tube type heat exchanger 2 is replaced with the raw water tank 31 and the condenser 32 in combination.
Although 9 was used, the invention is not limited to the shell-tube type heat exchanger, but may be, for example, a plate type heat exchanger, and the type of the heat exchanger is not limited.

[0062] Further, in the desalination apparatus shown in FIGS. 9 and 10, although the raw water flow rate Q ₄ are less discharged from the raw water tank 31 and the heat exchanger 29, the temperature from higher than the inlet temperature, is the discharge Raw water Q ₄ is stored in a separately provided tank 52 as shown in FIG.
By supplying the evaporator ₄ as raw water for evaporation to the evaporator 20, efficient distillation capacity, that is, distilled water can be recovered as an apparatus. This is a configuration example of the desalination apparatus according to the twelfth aspect of the present invention.

In the above example, the tank 52 is configured to store the raw water heated from the raw water tank 31 and the heat exchanger 29 of the desalination apparatus shown in FIGS. 9 and 10. Instead, in the desalination apparatus shown in FIGS. 1 to 8, the raw water heated by the condenser 32 that condenses the steam generated in the evaporator 20 is stored and supplied to each evaporator 20 from here. It may be.

As shown in FIG. 12, a water tank 61 having a shallow depth and an open top is provided, and a basin-type solar still 60 having a structure in which the opening of the water tank 61 is covered with a translucent cover 62. The raw water tank 31 stores the raw water Q ₄ discharged from the evaporator 20 and the heat exchanger 29 shown in FIGS. 9 and 10 in the water tank 61, and the water vapor evaporated from the stored raw water Q ₄ is covered by the cover 62. It is also possible to adopt a configuration in which the water is condensed on the back surface, collected by the collecting trough 63, and the distilled water W is collected. This is a configuration example of the desalination apparatus according to the invention of claim 13. By providing the basin-type solar still 60 in this manner, the distillation capacity of the entire apparatus is further improved.

In the above example, the tank 52 is configured to store the raw water heated from the raw water tank 31 and the heat exchanger 29 of the desalination apparatus shown in FIGS. 9 and 10, but the invention is not limited to this. Instead, the raw water heated by the condenser 32 that condenses the steam generated in the evaporator 20 of the desalination apparatus shown in FIGS. 1 to 8 may be stored in the water tank 61.

As shown in FIG. 13, a pool 70 having a large area with a shallow depth is provided.
And the raw water tank 31, evaporator 20 and heat exchanger 2 of FIG.
9. The raw water Q ₄ discharged from the basin-type solar still 60 shown in FIG. 12 and further heated by the condenser 32 for condensing the steam generated in the evaporator 20 of the desalination apparatus shown in FIGS. and storing the raw water, by evaporating the water vapor 71 from the raw water Q ₄ which is the stored solar energy, it can be precipitated sodium chloride 72 to the pool 70.

Thus, in addition to the recovery of distilled water, it is possible to recover salt and other useful salts contained in the raw water from concentrated raw water (eg, seawater). This is a configuration example of the desalination apparatus according to the invention described in claim 14.

[0068]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first aspect of the present invention, since the radiator for cooling the raw water in the raw water tank is provided, the temperature rise of the raw water in the raw water tank is suppressed, and the distillation performance is improved.

According to the second aspect of the present invention, the heat radiator is connected to the heat exchanger disposed in the raw water tank and the external radiator through the medium passage, and the thermo-water cools the raw water by repeating evaporation and condensation of the medium. Since the siphon type radiator is used, the heat of the raw water can be released without requiring any special power for heat release.

According to the third aspect of the present invention, since the medium that repeats evaporation and condensation between the heat exchanger and the radiator is water, the external radiator and the heat exchanger disposed in the raw water tank can be used. Not only can corrosion-resistant materials be used for pipes (portions that do not come in contact with salt water such as seawater) connecting pipes, but inexpensive materials can be used to reduce the price, and the material of the external radiator can be selected without restriction It is possible to select an efficient and highly heat-conductive material such as copper or aluminum and to configure an external radiator having high heat radiation efficiency.

According to the fourth aspect of the present invention, since the raw water tank and the radiator are arranged in a place where sunlight does not directly hit, a place where heat input is small, or a place suitable for heat radiation, the temperature of the raw water in the raw water tank is kept low. Since the rise is suppressed and the heat radiation efficiency of the radiator is improved, the rise in the temperature of the raw water can be further suppressed.

According to the fifth aspect of the present invention, the radiator and the external radiator can be efficiently radiated by using the sky heat radiation at night in the shade area inside or outside the desalination apparatus or in a place optimal for heat radiation. , The raw water in the raw water tank can be efficiently cooled.

According to the sixth aspect of the present invention, the open / close valve is provided in the raw water passage connecting the raw water tank and the radiator or the medium passage connecting the heat exchanger and the external radiator. When the raw water temperature is lower than the outside air temperature, the on-off valve is closed, so that heat can be prevented from entering the raw water in the raw water tank from the outside due to a rise in daytime temperature.

According to the present invention, the heat of the heat medium heated by the raw water through the heat exchanger in the raw water tank at night can be radiated to the outside through the heat collecting plate of the solar heat collector. Therefore, the heat of the raw water heated during the day can be efficiently radiated through the heat collecting plate at night.

According to the eighth aspect of the present invention, the heat medium heated by the raw water through the heat exchanger in the raw water tank at night is bypassed to the heat exchanger of the evaporator to collect heat of the solar heat collector. Since the bypass means is provided to send heat to the heat collector, the heat radiation through the heat collector plate of the solar collector at night is a completely reverse cycle to the daytime heat collection cycle, effectively reducing the temperature of the raw water in the raw water tank. Can be lowered.

According to the ninth aspect of the present invention, since the radiator for directly or indirectly cooling the raw water in the raw water tank is provided, the temperature of the raw water in the raw water tank can be further effectively reduced. .

According to the tenth aspect of the present invention, the condenser for condensing the steam from the evaporator is accommodated in a small-capacity tank, and the tank cools a predetermined flow rate of raw water necessary for the condensation of the steam. Since the same amount of raw water heated and discharged as water is discharged, the temperature of raw water in the raw water tank can be maintained substantially constant during operation with a small flow rate of supplied raw water.

According to the eleventh aspect of the present invention, since the condenser for condensing the water vapor generated in the evaporator is used as the heat exchanger, the temperature of the raw water in the raw water tank is kept substantially constant during operation with a smaller raw water flow rate. Can be kept.

According to the twelfth aspect of the present invention, raw water heated by a condenser for condensing water vapor generated in the evaporator is stored in a separately provided storage tank, and the stored raw water is evaporated in the evaporator. Since the means for supplying the raw water is provided, the raw water heated by the condenser can be effectively used, so that the distillation performance of the desalination apparatus is further improved.

According to the invention of claim 13, a basin-type solar still is provided, and raw water heated by a condenser for condensing water vapor generated in an evaporator in a water tank of the solar still is stored, Since the apparatus is configured to obtain distilled water, the distillation performance of the apparatus as a whole is further improved.

According to the fourteenth aspect of the present invention, there is provided a pool having a large area with a shallow depth, and the pool is provided with raw water and / or a solar still which is heated by a condenser for condensing steam generated in an evaporator. Since the raw water discharged from the water tank is stored, the raw water can be evaporated by using solar heat to recover salt and other useful salts in seawater.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a desalination apparatus according to the first aspect of the present invention.

FIG. 2 is a diagram showing a configuration example of a desalination apparatus according to the second aspect of the present invention.

FIG. 3 is a diagram showing a configuration example of a desalination apparatus according to the invention described in claim 4;

FIG. 4 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 5.

FIG. 5 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 6.

FIG. 6 is a diagram showing a configuration example of a desalination apparatus according to the invention described in claim 7;

FIG. 7 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 8;

FIG. 8 is a view showing a configuration example of a desalination apparatus according to the ninth aspect of the present invention.

FIG. 9 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 10.

FIG. 10 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 11;

FIG. 11 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 12;

FIG. 12 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 13.

FIG. 13 is a diagram showing a configuration example of a desalination apparatus according to the invention of claim 14.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Solar heat collector 11 Solar energy 12 Heat collecting plate 13 Heat medium 20 Evaporator 20-1 Evaporator 20-2 Evaporator 20-3 Evaporator 21 Can body 22 Heat exchanger 23 Steam 24 Piping 25 Switching valve 26 Switching valve 27 bypass line 29 heat exchanger 31 raw water tank 32 condenser 33 water vapor 34 air shield 34 'air shield 35 collecting gutter 37 heat exchanger 40 radiator 41 heat exchanger 42 external radiator 43 medium passage 44 on-off valve 50 Solar cell 51 Pump 52 Tank 60 Solar still 61 Water tank 62 Cover 63 Collection gutter 70 Pool 71 Water vapor 72 Salt

Claims (14)

[Claims] 1. A desalination apparatus using solar energy, comprising: a solar heat collector for heating a heat medium by solar energy;
A depressurization method that includes a heat exchanger and uses a heat medium heated by the solar heat collector as a heating source to perform heat exchange with raw water housed therein to generate steam from the raw water. An evaporator, a condenser disposed in a raw water tank containing raw water, receiving a steam generated in the evaporator and exchanging heat with the raw water to obtain distilled water, and directly converting the raw water in the raw water tank. Or a radiator for indirect cooling. 2. The desalination apparatus according to claim 1, wherein the radiator for indirectly cooling the raw water includes a heat exchanger disposed in the raw water tank and an external radiator. A desalination apparatus characterized in that the desalination apparatus is a thermosiphon-type radiator that cools raw water by repeating evaporation and condensation of the medium by connecting the radiator and an external radiator with a medium passage. 3. The desalination apparatus according to claim 2, wherein the medium that repeats evaporation and condensation between the heat exchanger and the radiator is water. 4. The desalination apparatus according to claim 1, wherein the raw water tank is disposed in a shade portion inside or outside the desalination apparatus or in a place where heat input to the raw water tank is small. A desalination apparatus characterized by the above-mentioned. 5. The desalination apparatus according to claim 1, wherein the radiator or the external radiator is installed inside or outside the desalination apparatus or in a location optimal for heat radiation. A desalination apparatus characterized by the above-mentioned. 6. The desalination apparatus according to claim 1, wherein a raw water passage connecting the raw water tank and the radiator or a water passage between the heat exchanger and the external radiator. A desalination apparatus, wherein an on-off valve is provided in a medium passage connecting the two, and when the raw water temperature in the raw water tank is lower than the outside air temperature, the on-off valve is closed. 7. A desalination device using solar energy, comprising: a solar heat collector for heating a heat medium by solar energy;
A depressurization method that includes a heat exchanger and uses a heat medium heated by the solar heat collector as a heating source to perform heat exchange with raw water housed therein to generate steam from the raw water. Evaporator, a condenser for condensing water vapor generated in the evaporator to obtain distilled water, and passing a heat medium disposed in a raw water tank containing raw water and passing through a heat exchanger in the evaporator. A heat exchanger for exchanging heat with the raw water, and heats the heat medium heated by the raw water through the heat exchanger in the raw water tank at night through the heat collecting plate of the solar heat collector. A desalination apparatus characterized by radiating heat to the water. 8. The desalination apparatus according to claim 7, further comprising: bypass means for bypassing a heat exchanger of the evaporator, wherein a heat medium heated by the raw water through a heat exchanger in the raw water tank at night is provided. A desalination apparatus, wherein the water is sent to a heat collecting plate of the solar heat collector. 9. The desalination apparatus according to claim 7, further comprising a radiator for directly or indirectly cooling the raw water in the raw water tank. 10. A desalination apparatus using solar energy, comprising: a solar heat collector for heating a heating medium by solar energy;
A depressurization method that includes a heat exchanger and uses a heat medium heated by the solar heat collector as a heating source to perform heat exchange with raw water housed therein to generate steam from the raw water. Evaporator, and a condenser for condensing water vapor generated in the evaporator, the condenser is housed in a small-capacity tank,
A desalination apparatus characterized in that a predetermined flow rate of raw water required for condensation of the water vapor is supplied into the tank as cooling water and the same amount of heated raw water is discharged. 11. The desalination apparatus according to claim 10, wherein a combination of the condenser and a small-capacity tank is a heat exchanger. 12. The desalination apparatus according to claim 1, wherein raw water heated by a condenser that condenses steam generated in the evaporator is stored in a storage tank provided separately, A desalination apparatus comprising means for supplying the stored raw water to the evaporator as raw water for evaporation. 13. The desalination apparatus according to claim 1, further comprising a water tank having a shallow depth of water and an open upper part, wherein the opening of the water tank is covered with a translucent cover. A basin-type solar still is provided, and raw water heated by a condenser that condenses water vapor generated in the evaporator in a water tank of the solar still is stored to obtain distilled water. Desalination equipment. 14. The desalination apparatus according to claim 1, further comprising a pool having a large area with a shallow water depth, wherein the pool is provided with a condenser for condensing steam generated in the evaporator. A desalination apparatus for storing heated raw water and / or raw water discharged from a tank of the solar still, and recovering salt and other useful salts in the raw water from the raw water using solar heat. .