JP2002350026A - Planar structure and space-cooling method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wet the surface of an outer wall uniformly and supply the water discharged from a conduit without splashing it at the time of supplying water to the outer wall having hydrophilic properties to cool down a space and structure by latent heat of vaporization. SOLUTION: This is a planar structure comprising a planar body (outer wall) having a hydrophilic surface having a water contact angle of 10 deg. or less and conduits 3, 3, etc., attached to this planar body (outer wall) with spouts 3a formed at proper intervals along the lengthwise direction of a member to supply water to the surface of the planar body. The interval in the lengthwise direction of the member of the spout 3a formed in the conduit 3 is 5 cm or shorter, and the distance L from the spout to the surface for the planar body (outer wall) having the hydrophilic surface is 3 cm or shorter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar structure integrally provided with a water pipe for cooling a space by latent heat of evaporation of water supplied to a wall surface, and a space cooling method using the same.

[0002]

2. Description of the Related Art Due to the recent increase in reinforced concrete structures and the like, in a city or an area where buildings are densely packed, a heat island phenomenon occurs in which the temperature rises due to heat radiated from the structures in summer. As a result, the pedestrian suffers considerable bodily sensation and pain, and the cooling device is excessively used, and the heat released to the outside causes a vicious cycle in which the ambient temperature further rises.

[0003] In order to solve this problem, for example,
In Japanese Patent No. 32503 (conventional example 1), as shown in FIG. 6, a device for attaching a watering pipe 52 to a structure 50 with a stopper 51 to supply water to the structure 50 is proposed. No. 159866 (conventional example 2)
Then, as shown in FIG.
Further, a device has been proposed in which a temperature sensor 62 is attached, and when it is detected that the temperature sensor 62 has risen above a certain temperature, water is supplied from the nozzle 61 to the surface of the structure 60.

However, when water is simply sprayed on the surface of an existing structure as in the above-described cooling device, the water supplied to the wall surface of the structure due to the water repellency of the surface material of the structure causes water droplets to form. Then, the wind hits the wall surface of the building, the wind of the building flowing along the wall surface, and the like scatters around, and water drops come down to passers-by. Further, due to the water repellency of the surface material of the structure, unevenness such as discontinuity of the water film occurs, and problems such as inability to efficiently evaporate occur. Furthermore, there is a problem that water moss is generated by water supplied to the wall surface, and the wall surface becomes dirty.

Accordingly, the present inventors have proposed the above-mentioned Japanese Patent Application No. 2000-40011.
In No. 4, in a predetermined area of the structure wall or roof surface,
We proposed a method for cooling urban space by forming a hydrophilic layer capable of holding a water film, supplying water to the hydrophilic layer forming area, and cooling the surrounding air and structures by the latent heat associated with evaporation. .

[0006]

DISCLOSURE OF THE INVENTION The present inventors have filed a prior patent application.
After 2000-400114, repeated tests were carried out for implementation, and it was found that it was necessary to satisfy the specified water supply conditions to uniformly wet the wall, and that if the distance from the water outlet to the wall was long, the wind Problems have been identified, such as being blown away.

On the other hand, when impurities such as calcium, magnesium and iron existing in the used water are evaporated to dryness by the heat of sunlight in flowing water on the wall surface, carbonates, sulfates or silicates are removed. It was also found that the chlorides were precipitated on the wall surface and scaled, causing problems such as inhibiting hydrophilicity and inhibiting uniform wettability.

Therefore, a first object of the present invention is to supply water to a planar body such as a wall surface having hydrophilicity and to cool the space and the structure by the latent heat of evaporation. An object of the present invention is to provide a planar structure that uniformly wets and supplies water discharged from a water pipe without scattering.

Next, the second problem is that chlorides such as carbonates, sulfates and silicates precipitate on the surface of the planar body,
An object of the present invention is to provide a space cooling method that does not scale.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the first problem. First, when water is discharged from the water pipe to the planar body through the water discharge port, the interval between the water discharge ports is reduced. It was found that the water film was not evenly arranged on the surface even if the amount of water was adjusted when the distance was more than a certain distance. At the time of filing, the present inventors predicted that if the wall surface was made super-hydrophilic, the water supplied to the wall surface would spread uniformly along the wall surface, and would spread uniformly. According to the experiment described above, it has been found that even if the surface is a superhydrophilic surface, the water existing on the surface is affected by gravity and a force in a falling direction acts thereon, so that the wetting spread width is balanced at a width of about 5 cm. In addition, it was found from experiments described below that when the water contact angle (the tangent angle at the end of the water droplet) of the hydrophilic surface is 10 ° or less, the water wettability (wet spreadability) becomes good.

Therefore, as a first aspect of the present invention for solving the first problem, a planar body having a hydrophilic surface having a water contact angle of 10 ° or less, and a planar body attached to the planar body are provided. A planar structure comprising a water pipe formed at appropriate intervals along the longitudinal direction of the member and a water pipe for supplying water to the surface of the planar body, wherein a water outlet formed in the water pipe; A planar structure is provided, wherein a member longitudinal interval is 5 cm or less.

Next, according to a second aspect of the present invention, the distance from the water discharge port to the surface of the planar body having a hydrophilic surface is 3 mm.
The planar structure according to claim 1, which is not more than cm.
According to experiments by the present inventors, when the distance from the water discharge port to the surface of the planar body having a hydrophilic surface exceeds 3 cm, the supplied water easily reaches the planar body and becomes mist-like. Since this phenomenon becomes remarkable when the wind is strong, the distance is set to 3 cm or less.

According to a third aspect of the present invention, there is provided the planar structure according to any one of the first and second aspects, wherein the hydrophilic surface is provided by a photocatalytic layer. The hydrophilicity can be formed by a material having a high degree of hydrophilicity such as porous silica (SiO ₂ ) or water glass, but preferably TiO ₂ , ZnO, SrTiO ₃ , WO ₃ , Bi ₂
It is preferably formed by a photocatalyst such as O ₃ , Fe ₂ O ₃ , and SnO ₂ .

According to a fourth aspect of the present invention, there is provided the planar structure according to any one of the first to third aspects, wherein the planar body is an outer wall material or a glass plate.

Next, according to a fifth aspect of the present invention to solve the second problem, in the planar structure according to any one of the first to fourth aspects, water is sprayed from the water outlet onto the surface of the planar body. Supplying and cooling the surrounding air and the planar structure by the latent heat associated with evaporation, the supply water is characterized by using water that has been subjected to a physical treatment for removing impurities such as calcium, magnesium and iron. A space cooling method is provided.

According to a sixth aspect of the present invention, there is provided a space cooling method according to the fifth aspect, wherein a chemical cleaning agent is further added to the water subjected to the physical treatment to promote a cleaning effect. .

According to a seventh aspect of the present invention, there is provided the space cooling method according to any one of the fifth and sixth aspects, wherein the content of iron ions in the feed water is 0.005 mg / l or less. If the spouted water contains a large amount of iron ions, iron adheres to the hydrophilic surface and is colored brown. This is because the photocatalyst is photoexcited to cause a reduction reaction, and iron ions in water are deposited and adhered to the surface. For this reason, the outer wall surface that emphasizes aesthetics will be stained, but as a result of an experiment described below, if the iron ion content is 0.005 mg / l or less,
It has been found that such a coloring phenomenon does not occur.

According to an eighth aspect of the present invention, there is provided a space cooling method according to any one of the fifth and seventh aspects, wherein water flushing is periodically performed with the water subjected to the physical treatment.

According to a ninth aspect of the present invention, there is provided a space cooling method according to any one of the sixth and seventh aspects, wherein the physical treatment is performed and water flushing is performed with water to which a chemical cleaning agent is added. .

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall perspective view of a building 1 to which the present invention is applied. As shown in FIG.
On one or a plurality of wall surfaces on the east, west, and south sides of the building 1, a plurality of, in the illustrated example, three-stage water pipes 3, 3,. Are piped, and discharge ports 3a provided at predetermined intervals in the longitudinal direction of the members of the water conduits 3, 3,...
Is supplied with water.

The photocatalyst films 5, 5,... Are formed in advance on the wall surface region including the water spray region.
When the water supplied to the formation region of the evaporates, the heat of the surrounding air is taken away to cool the atmosphere and cool the structure. The photocatalyst film 5 may be formed on the entire wall surface of the building.

Photocatalyst is a general term for an optical semiconductor substance represented by titanium oxide, which has been used in many fields in recent years as a material having excellent performance in purifying action such as antifouling, sterilization and deodorization. In the invention, the second function of the photocatalyst, that is, super hydrophilicity is mainly used.

When water is supplied to the wall surface of the structure on which the photocatalyst film 5 is formed, the water does not form water droplets but flows down as a uniform film due to the superhydrophilicity of the photocatalyst. As a result, it is not scattered by the wind and the water film does not have unevenness, so that it evaporates uniformly and efficiently,
The latent heat associated with the evaporation effectively cools the surrounding air and structures. In addition, the generation of water moss can be suppressed by the photocatalytic effect. The photocatalyst film 5 can be formed on glass other than the outer wall material made of a cement-based material, ceramic, or the like. As the glass,
Heat ray absorbing glass and heat ray reflecting glass having the effect of promoting evaporation are effective.

In the illustrated example, even if water is supplied to the building wall, evaporation is not promoted if the amount of solar radiation is insufficient, so that the pyranometer 2 for measuring the amount of solar radiation hitting the building wall is used.
0 and a valve controller 21, and a control valve 22 is provided in the middle of the water supply main pipe 2, and based on a value measured by the pyranometer 20, the valve controller 21 is provided.
Thus, the opening degree of the control valve 22 is adjusted to control the supply amount of water.

More specifically, including the water supply equipment, a water storage tank 10 is installed on the roof of the building 1 and water is supplied from the water storage tank 10 through the water supply pipe 2 and the water supply pipes 3, 3,. Is supplied to the wall surface. As the water stored in the water storage tank 10, rainwater, tap water, well water, industrial water, and the like can be used, but it is preferable to use rainwater or the like from the viewpoint of resource reuse.

When rainwater is used, rainwater storage equipment is separately provided as shown in FIG. In the figure, a rainwater storage tank 12 is provided on the ground surface or underground, and rainwater that has fallen on the roof of the building 1 is guided by the downspouts 11 and 11, and reused water such as intermediate water is guided by the makeup water pipe 13. Water is purified by the water treatment device 14,
The water is pumped by the pump 15 to the water storage tank 10 arranged on the roof.

The water stored in the water storage tank 10 is supplied from the discharge ports 3a of the water pipes 3, 3,. As the water conduit 3, a water outlet 3a formed at an appropriate interval along the longitudinal direction of the member and having an interval of 5 cm or less is used, and the water outlet 3a extends from the water outlet 3a to the surface of the planar body having a hydrophilic surface. It is arranged so that the distance L is 3 cm or less.

By setting the interval between the water outlets 3a in the longitudinal direction of the member to 5 cm or less, water films formed by water supplied from the adjacent water outlets 3a overlap each other, and a uniform water film is formed. .

In this case, increasing the number of water outlets 3a and reducing the interval does not hinder the spreadability of the water, but the cost of perforation is undesirably high, so that the interval is preferably at least 1 cm or more. Although the present invention also considered using a sponge-shaped discharge pipe having a large number of discharge ports in the course of the experiment, it was found that if the distance between the discharge ports was too close, the material strength was reduced, which was undesirable. Was.

On the other hand, if the diameter of the water outlet 3a is too large, the water film becomes uneven, and if it is too small, clogging occurs. Therefore, the diameter of the water outlet 3a is desirably about 0.1 mmφ to about 10 mmφ.

The distance L from the water outlet 3a to the surface having a hydrophilic surface (hereinafter referred to as water reach distance) is 3 cm.
The reason why the following is desirable is that, as shown in an experimental example described later, when the water reaching distance L exceeds 3 cm, mist or the like is generated in a range of daily wind speed.
There is no problem if the water reaching distance L is 3 cm or less, but it is desirable to arrange the outlet 3a as close as possible to the wall surface. In addition, since the hydrophilic surface portion directly receiving water discharge is susceptible to erosion, in order to prevent erosion of this portion, it is particularly desirable to increase the thickness of the photocatalyst or to configure the photocatalyst with a material such as metal.

On the other hand, it is desirable that the amount of water flowing out from the water outlet 3a is approximately 100 to 300 ml / (min · m). If the amount of water supplied is less than 100 ml / (min · m), the hydrophilic surface cannot be uniformly wetted.

In the photocatalyst film 5 formed on the wall surface of the building, the electron-hole pairs generated by absorbing light and exciting the semiconductor migrate to oxygen and water on the semiconductor surface to generate active oxygen. It is an energy conversion material. Among various semiconductors, there are those which recognize that the hole is not transferred to water, but is consumed by the structural change of the surface to remarkably enhance water wettability.

Such a superhydrophilic action does not always coincide with the photocatalyst group having a high active oxygen generation efficiency. Some of them have excellent hydrophilicity but low activity, and some have high activity but poor hydrophilicity. In the present invention, it is desirable to select and use a photocatalyst having excellent hydrophilicity among various photocatalysts. Specifically, TiO ₂ , ZnO, SrTiO ₃ , WO ₃ , B
Examples include photocatalytic semiconductor materials such as i ₂ O ₃ , Fe ₂ O ₃ , and SnO ₂ . In addition, as a material for imparting hydrophilicity other than the photocatalyst, a material such as porous silica (SiO ₂ ) or water glass can be used.

In this case, the degree of hydrophilicity needs to be such that the supplied water flow completely wets and spreads.
As shown in, approximately the water contact angle (the tangent angle at the end of a water drop)
Is 10 ° or less. Further, when the water contact angle is 5 ° or less, the wet-spreadability is significantly improved.

By the way, impurities existing in water (rainwater, well water, tap water, industrial water, etc.) sprinkled on the wall surface, especially ions of calcium, magnesium, iron, etc., evaporate on the wall surface by the heat of sunlight into flowing water. When dried, carbonates, sulfates or silicates precipitate on the walls, which are scaled and impede hydrophilicity or even wettability. There is a problem that contaminants such as dust adhere and cause dirt.

Therefore, in the water treatment device 14, it is desirable to carry out physical water treatment for removing ions such as calcium, magnesium and iron. As such a device, it is desirable to use a water treatment device comprising a water softening device, a filtration device and an activated carbon adsorption device. The water softening device is a device which passes raw water through a layer of a Na-type cation exchange resin to exchange polyvalent cations, such as calcium and magnesium, which are hardness components, with Na to soften the water. Hardness is 0.05-0.2 (CaCO
₃ ppm) will be the management target for water management. Further, the filtration device is used for removing impurities such as dust mixed from the atmosphere, and the activated carbon adsorption device is used for removing iron in water. It is clear from experiments and the like described later that if the iron content is 0.005 mg / l or less, no color change occurs on the surface.

[0038] A chemical cleaning agent may be added to the water after the physical treatment to remove scaled dirt on the wall surface. In this case, examples of the chemical detergent include EDTA and its derivatives, organic acid detergents such as citric acid, sulfamic acid, tartaric acid, formic acid, glycolic acid and oxalic acid, or hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, hydrofluoric acid and peroxide. An inorganic acid-based cleaning agent such as hydrogen oxide can be used.

However, even if the treated water and the treated water to which the chemical cleaning agent is added are used, dirt on the wall surface and scale adhesion cannot be completely avoided. Therefore, water flushing is periodically performed using the treated water. It is desirable to carry out. It is desirable that the water flushing is periodically performed every night at night when water is not supplied to the wall surface. For the purpose of strong scale-adhesion peeling cleaning and shortening of cleaning time, the chemical cleaning agent can be added during water flushing. This chemical cleaning agent is added by adjusting the type and concentration of the chemical according to the degree of contamination and the frequency of cleaning.

[0040]

[Embodiment 1] In this embodiment 1, the relationship between the water contact angle (°) and the flowing water width (cm) was examined. In the experiment, the plate having hydrophilicity was set upright (90 °),
Water is dropped at a flow rate of 2 ml / mi from the end of the mm Pasteur,
After the flow reached a steady state (after 3 to 5 minutes), the width of the water flow at 1.5 cm, 4 cm, and 6.5 cm below the dropping point was measured for each water contact angle. As a result, as shown in FIG. 3, it was found that the width of flowing water was extremely improved with a water contact angle of 10 ° as a boundary value.

[Embodiment 2] In this embodiment 2, hoses or pipes commercially available from various manufacturers are used as water conduits, and the discharge port pitch is changed and the amount of flowing water is changed so that the uniformity of the water film is improved. , Water discharge, outdoor life, etc. were evaluated. The experiment was conducted using the watering method A shown in FIG.
And water spraying method B shown in FIG. In the former water spraying method A, a hood 7 also serving as a running water guide is attached to an upper part of a plate material 6 having a photocatalyst layer formed on the surface, and water is discharged from a discharge port 8a formed on a lower surface of a water guide pipe 8 provided in the hood 7. The water spraying method B is a water spraying method in which water is sprayed from a water guide pipe 8 in which a discharge port 8a is arranged at an upper position of a plate material 6 having a photocatalyst layer formed on the surface thereof so as to face the plate material surface. . Table 1 shows the results of these tests.

[0042]

[Table 1] From Table 1, the flow rate from the spout is approximately 100-300 ml.
/ (min · m) was found to be desirable.

[Embodiment 3] In this embodiment 3, an experiment was conducted with respect to a preferable interval in the longitudinal direction of the water outlet 3a formed in the water conduit 3. The experiment was performed by Sekisui Chemical's PVC pipe (VP).
Water outlets of various diameters are formed in the longitudinal direction,
Was supplied to the surface of the plate material having a hydrophilic surface according to the method described in (1), and the flowing water width (mm) when flowing down the surface was measured. Table 2 shows the results.

[0044]

[Table 2] As shown in Table 2, even when the amount of water supplied to the wall surface was changed, the width of the flowing water was balanced at a maximum width of approximately 50 mm. Therefore, it has been found that it is desirable that the interval between the water outlets 3a in the longitudinal direction of the member be 5 cm or less.

Example 4 In Example 4, the relationship between the distance L (water reaching distance) from the water outlet to the surface of the planar body having a hydrophilic surface and the degree of mist generation was examined. In the experiment, the discharge amount was set to 25 for each of the watering method A and the watering method B.
Water was supplied to the wall surface while changing the water reaching distance L while keeping the water constant at 0 ml / (min · m), and the presence or absence of mist was examined in relation to the changing wind speed. Table 3 shows the results.

[0046]

[Table 3] Example 5 In Example 5, an experiment was conducted on the allowable content of iron ions in the water supplied to the wall surface. The experiments showed that the iron ion content was 0.005 mg / l, 0.025 mg / l, 0.05 mg / l and
For four cases of water of 0.15 mg / l, a running water test was conducted for 600 hours, and the color change of the surface was observed. Table 4 shows the results.

[0047]

[Table 4] From Table 4, it was found that if the iron ion content in the feed water was 0.005 mg / l or less, no color change occurred.

[0048]

As described above, according to the first to third aspects of the present invention, water is supplied to a planar body having a hydrophilic surface, and the space and the structure are cooled by the latent heat of evaporation. It is possible to uniformly wet the surface of the planar body and to supply the water discharged from the water pipe without scattering.

According to the present invention, since crystals such as carbonates, sulfates or silicates are prevented from depositing on the hydrophilic surface and being scaled, favorable characteristics can be obtained over a long period of time. The hydrophilic surface can be maintained, and the surface of the planar body can be prevented from being stained.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a building 1 to which the present invention is applied.

FIG. 2 is a longitudinal sectional view of a water pipe 3 part.

FIG. 3 is a diagram showing a relationship between a water contact angle and a flowing water width.

FIG. 4 is a cross-sectional view showing a watering method A in the embodiment.

FIG. 5 is a cross-sectional view showing a watering method B in the embodiment.

FIG. 6 is a diagram showing a cooling device according to Conventional Example 1.

FIG. 7 is a diagram showing a cooling device according to Conventional Example 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Building, 2 ... Water pipe, 3 ... Water pipe, 5 ... Photocatalytic film, 1
0: water storage tank, 11: downspout, 12: rainwater storage tank,
Reference numeral 13: makeup water pipe, 14: water treatment device, 15: pump, 20: pyranometer, 21: valve controller, 22: control valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Ishida 4-4-2, Nihonbashi Honishicho, Chuo-ku, Tokyo Mitsui Second Annex Shin Nippon Air Conditioning Co., Ltd. (72) Inventor Kunio Yokoyama Nihonbashimoto, Chuo-ku, Tokyo Mitsui No. 2 Annex, Shin Nippon Air Conditioning Co., Ltd. (72) Inventor Haruhisa Shuto 4-4-2, Nihonbashi Honishicho, Chuo-ku, Tokyo Mitsui No. 2 Annex Shin Nihon Air Conditioning Co., Ltd. (72) Inventor Takashi Kimura 4-4-2, Nihonbashi-Honishi-cho, Chuo-ku, Tokyo Mitsui 2nd Annex Shin Nippon Air Conditioning Co., Ltd. (72) Inventor Nobuo Onishi 2-8-1 Motomura Chigasaki-shi, Kanagawa Japan Advanced Technology Incubation Co., Ltd. Inside Systems Laboratories (72) Inventor Kazuhito Hashimoto 2073-2 Iijima-cho, Sakae-ku, Yokohama-shi, Kanagawa-ken, New City Hongodai D Building 213 (72) inventor IsoKazu Toshio Nihonbashi, Chuo-ku, Tokyo Motoishi-cho 3-chome No. 3 No. 8 Co., Ltd. Eco Global Institute in the F-term (reference) 2E001 DD04 EA01 FA04 HE10 3L044 AA00 CA18 DB01 DD03

Claims (9)

[Claims] 1. A planar body having a hydrophilic surface having a water contact angle of 10 ° or less, and a water outlet formed at an appropriate interval along the longitudinal direction of the planar body while being attached to the planar body. A planar structure comprising a water pipe for supplying water to the surface of the body, wherein a member longitudinal interval of a water outlet formed in the water pipe is 5 cm.
A planar structure characterized by the following. 2. The planar structure according to claim 1, wherein the distance from the water outlet to the surface of the planar body having a hydrophilic surface is 3 cm or less. 3. The planar structure according to claim 1, wherein the hydrophilic surface is provided by a photocatalyst layer. 4. The planar structure according to claim 1, wherein the planar body is an outer wall material or a glass plate. 5. The planar structure according to any one of claims 1 to 4, wherein water is supplied from the water outlet to the surface of the planar body,
In cooling the surrounding air and the planar structure by latent heat due to evaporation, space cooling characterized by using, as the supply water, water that has been subjected to a physical treatment for removing impurities such as calcium, magnesium, and iron. Method. 6. The space cooling method according to claim 5, wherein a chemical cleaning agent is further added to the water subjected to the physical treatment so as to promote a cleaning effect. 7. The iron content of the feed water is 0.005 mg.
7. The space cooling method according to claim 5, wherein the ratio is not more than / l. 8. The space cooling method according to claim 5, wherein water flushing is periodically performed with the water subjected to the physical treatment. 9. The space cooling method according to claim 6, wherein the water is flushed with water to which a chemical cleaning agent is added while performing the physical treatment.