JPH08312018A - Improving method for surface temperature and its system - Google Patents

Abstract

PURPOSE: To easily improve urban surface temperature by utilizing the evaporation latent heat of water. CONSTITUTION: A water retention body 10 consisting of porous ceramics is arrangedly provided on the whole surface of a roof floor of a building. The water retention body 10 holds rain water brought by a rain fall, and the heat of the sunlight evaporates moisture kept in the body 10, and the quantity of heat given by the sunlight is replaced with the evaporation latent heat. A rise of the surface temperature of the water retention body 10 is therefore restrained so much as the quantity of heat replaced with the evaporation latent heat of the water, and the rise of the surface temperature on the roof floor is thereby restrained. In addition, the quantity of the water decreased by the evaporation is supplied to the water retention body 10 by supplying rain water collectedly stored in a water reservoir 21 through a supply pipe 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface temperature improving method and system for improving urban surface temperature by utilizing latent heat of vaporization of water.

[0002]

2. Description of the Related Art In modern cities, a peculiar climate, a so-called urban climate, is created by concrete structures, pavement of road surfaces or artificially radiated heat. . This deterioration of the thermal environment further causes an increase in the amount of energy used for cooling the building, which causes a vicious cycle of increasing waste heat.

Such an increase in the surface temperature of the city causes further problems at the global environment level such as global warming and abnormal weather phenomenon.

As a method of solving this, there has been proposed a method of planting and cultivating a plant on the roof or the road of a building. However, this method has a problem that plant management is troublesome.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to make it possible to easily improve the surface temperature of a city by utilizing latent heat of vaporization of water. It is to provide an improvement method and system.

[0006]

The surface temperature improving method according to claim 1 is a method for suppressing a temperature rise at a portion where the surface temperature rises upon receiving sunlight, and While disposing a porous water retainer capable of retaining water at a location where the surface temperature rises, replenishing water to the water retainer, and vaporizing the water retained in the water retainer by heat from sunlight, The amount of heat generated by sunlight is replaced with the latent heat of vaporization of water to suppress an increase in the surface temperature at the temperature rising portion.

In this surface temperature improving method, a porous water retaining body containing water is arranged at a portion of the roof or side wall of a building or on the road where the surface temperature of the building rises due to sunlight. The water retained in the water retainer is vaporized by the heat of the sunlight and replaces the amount of heat of the sunlight with the latent heat of vaporization of water. Therefore, an increase in the surface temperature of the water retainer is suppressed by the amount of the latent heat of vaporization of water, and an increase in the surface temperature of a city or the like is suppressed.

The surface temperature improving system according to claim 2 is
It is formed by a porous body that is placed in a place where its surface temperature rises in response to sunlight and is capable of retaining water, and the heat of sunlight evaporates its water content to convert the heat of sunlight into latent heat of vaporization of water. The water retaining body to be replaced and water supply means for replenishing the water retaining body with water and maintaining the water retaining body in a water-containing state are provided.

In this surface temperature improving system, when the water retaining body arranged on the roof or the side wall of the building or on the road where the surface temperature rises due to the sunlight, the water retaining body holds the water retaining body. The generated water vaporizes and replaces the amount of heat generated by sunlight with the latent heat of vaporization of water. The amount of water reduced from the water retaining body by this vaporization is replenished by the water supply means. Therefore, the water retention body is always maintained in a state containing water,
The rise in surface temperature is stably suppressed.

The surface temperature improvement system according to claim 3 is
The surface temperature improving system according to claim 2, wherein the water retaining body is arranged on a roof or a side wall of a building or on a road.

The surface temperature improving system according to claim 4 is
The surface temperature improvement system according to claim 2 or 3, wherein the water retainer is formed of ceramic into a predetermined shape, and at least the upper surface thereof is in a bisque-fired state.

The surface temperature improving system according to claim 5 is
The surface temperature improving system according to any one of claims 2 to 4, wherein the water supply means includes a water tank for collecting and storing rainwater, and a supply means for supplying rainwater from the water tank to the water retaining body. It consists of

In this surface temperature improving system, rainwater is collected and stored by the water tank and is supplied to the water retainer by the supply means. Therefore, rainwater can be used as a water source, and the surface temperature of a city or the like can be improved only by the natural circulation system without using artificial energy for cooling.

The surface temperature improving system according to claim 6 is
The surface temperature improving system according to any one of claims 2 to 5, wherein the water supply means automatically replenishes the water retainer with water at predetermined time intervals.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows the overall structure of a surface temperature improving system according to an embodiment of the present invention. In this surface temperature improvement system, a plurality of water retainers 10 are provided on the entire rooftop of the building.
Water is supplied from the water supply means 20 to these water retaining bodies 10.

As shown in FIG. 2, the water retaining body 10 is made of a porous ceramic made of zeolite or the like. The central pore diameter of the water retainer 10 is, for example, about 3.2 μm.
The porosity is appropriately determined within the range of about 5% to 40%. The water retainer 10 can hold water by a large number of holes formed in the water retainer 10, and is brought into a water-containing state by rainfall or replenishment from the water supply device 20. The water retained in the water retainer 10 is vaporized by receiving the heat of the sun.

The water supply means 20 includes a water tank 21 for collecting and storing rainwater, and a plurality of supply pipes 2 as a supply means.
2 and. The water storage tank 21 has an upper opening and is arranged on the roof of a building so that rain water can be naturally collected and stored in the water storage tank 21 during rainfall. The supply pipe 22 is provided below the water storage tank 21, and the rainwater in the water storage tank 21 is supplied to the water retaining body 10 via the supply pipe 22. The supply pipe 22 is provided with a valve (not shown), and by adjusting the valve, water can be supplied to the water retaining body 10 as needed.

In the surface temperature improving system having such a structure, rainwater is supplied to the water retaining body 10 by rainfall, and at the same time, rainwater is stored in the water tank 21.

After that, when the rain stops and the water retainer 10 is warmed by the heat of the sunlight, the water retained in the water retainer 10 begins to vaporize from the surface of the water retainer 10. That is, the amount of heat of sunlight is replaced by latent heat of vaporization, and the rise in the surface temperature of the water retaining body 10 is suppressed by the amount of latent heat of vaporization.

When the weather continues to be fine, the rainwater retained in the water retaining body 10 decreases. Therefore, the valve of the water supply means 20 is adjusted to replenish the rainwater in the water tank 21 to the water retaining body 10 through the supply pipe 22. . As a result, the water retaining body 10 holds a sufficient amount of rainwater again, and the rainwater retained in the water retaining body 10 is vaporized by the heat of the sunlight as described above. By repeating such an action, an increase in the surface temperature of the water retaining body 10 is suppressed, that is, an increase in the surface temperature of the building roof where the water retaining body 10 is arranged is suppressed.

As described above, according to the surface temperature improving system of this embodiment and the improving method using the same, it is possible to easily suppress the rise of the surface temperature of the building only by the natural energy of the latent heat of vaporization of water. Therefore, if many water retention bodies are installed throughout the city, it is possible to suppress an increase in daytime temperature and improve the global environment, particularly in the summer of the city.

Further, since rainwater is used as a water source, the urban surface temperature can be improved only by the natural circulation system without using artificial energy for cooling.

Further, the effects of this embodiment will be specifically described with reference to experimental examples.

As the specimens, a rooftop concrete plate (rooftop of Kyushu University Faculty of Agriculture No. 2 Building), two concrete plates, plant leaves (sinking flower pots), soil (sand loam soil) and porous ceramic water retainer (Novocerax; Koransha Shoji) 4) were prepared.

The main component of the porous ceramic water retaining body was zeolite, and the central pore diameter was 3.2 μm and the porosity was 28.5%. The front surface was coated with glaze, while the back surface was not coated with glaze and was in an unglazed state. The size of one porous ceramic water retaining body is 29.5 cm x
It was set to 29.5 cm × 2.5 cm.

Three of the porous ceramic water retaining bodies had the front surface (the surface coated with the glaze) as the upper surface, and the other one had the back surface (the unglazed surface) as the upper surface. One of the ones with the surface on top is dry without water and the other one
One is soaked in a water tank containing water to expose the surface from the water, and the other one is soaked in a water tank containing water and then taken out from the water tank to contain water. It was in a state that The one having the back surface as the upper surface was immersed in a water tank filled with water and then taken out from the water tank to contain water. In addition, one of the concrete plates has a front surface as an upper surface, and the other has a back surface as an upper surface.

After that, these test pieces were arranged horizontally on a concrete roof as shown in FIG. 3, and the surface temperature and the water content of the porous ceramic water retaining body which was taken out from the water tank after being immersed in the water tank The amount of reduction was measured.

The surface temperature of each sample was measured with a thermotracer (6T62 type), and the amount of water loss was measured with an electronic balance.
Each measurement was made at 20 minute intervals. Further, the solar radiation amount was measured by a solar radiation sensor and a Cadek data logger, the temperature and humidity were measured by a thermocouple thermometer, and the pure (net) radiation amount was measured by a CN-11 type pen recorder.

On the day of the experiment (July 21, 1994), the weather conditions were clear in the morning and clouds in the afternoon, and the amount of cloud change was large.

FIG. 4 shows changes with time in the surface temperature of each test piece. As is clear from FIG. 4, the rooftop concrete plate shows the highest temperature, and the porous ceramic water retainer (containing water;
The one with the unglazed surface as the top) showed the lowest temperature. The difference was large during the day and small in the evening. Further, the maximum surface temperature of each test piece was as shown in Table 1.

[0032]

[Table 1]

The air temperature at the time when the maximum surface temperature of each sample was measured was 36.7 ° C, and the wet bulb temperature was 27.4 ° C. As is clear from Table 1, the porous ceramic water retaining body showed a lower temperature than the concrete plate. Also, even with a porous ceramic water retainer, the one that has been hydrated shows a lower temperature than the one that is dry, and the one that has been hydrated is better when taken out from the water tank than when in the water tank. It showed a low temperature. Further, regarding the one taken out from the water tank, the one having the unglazed surface as the upper surface showed a lower temperature than the one having the surface coated with the glaze as the upper surface. The one with this unglazed surface as the top showed a lower temperature than plant leaves and soil.

FIG. 5 shows changes with time in the temperature difference between the surface temperature and the air temperature of each specimen shown in FIG. As is clear from FIG. 5, the rooftop concrete plate exhibited an excessively high temperature of about 20 ° C. from 12:00 to 14:00. On the other hand, the porous ceramic water retainer (containing water; the unglazed surface being the upper surface) showed a maximum value of 9 ° C during the day, and an average value of 5 ° C lower. Both the plant leaf and soil became cooler than the air temperature, but the temperature difference between them was a porous ceramic water retaining body (water containing;
The one with the unglazed surface as the top) did not reach.

FIG. 6 shows the changes over time in the temperature difference between the surface temperature of the rooftop concrete plate and the surface temperature of other samples for each of the specimens shown in FIG. As is clear from FIG. 6, it is understood that the surface temperature of the porous ceramic water retainer (containing water; with the unglazed surface as the upper surface) is significantly lower than the rooftop concrete plate.

FIG. 7 shows the relationship between the surface temperature of the rooftop concrete plate and the surface temperature of other samples for each of the specimens shown in FIG. As is clear from FIG.
It can be seen that there is a linear correspondence between the surface temperature of each specimen and the surface temperature of the rooftop concrete plate.

FIG. 8 shows the change over time in the weight of the porous ceramic water retainer that was immersed in the water tank and then taken out from the water tank. FIG. 9 shows the change in the amount of water evaporation obtained with reference to FIG. It represents a change. As is clear from FIG. 9, the porous ceramic water retainer (containing water; with the unglazed surface as the upper surface) showed evaporation of 0.94 mm / hr for 1 hour before and after the maximum temperature, and the net radiation amount 37
155% of cal / hr is converted to latent heat of vaporization. This is due to the oasis effect due to the small experimental scale. However, since the surface temperature at that time is higher than the wet-bulb temperature (27.5 ° C.), it means that the evaporation of water was being resisted.

On the other hand, the porous ceramic water retaining body (containing water; the surface on which the glaze was applied is the upper surface) shows evaporation of 0.3 mm / hr for 1 hour before and after the maximum temperature, and the net radiation amount is 37 cal / 52% of the hr is converted to latent heat of vaporization. That is, the low surface temperature of the porous ceramic water retainer (containing water; the unglazed surface as the upper surface) is due to the large amount of conversion of heat received by water (net radiation) into latent heat of vaporization. Recognize.

The difference in surface temperature between the concrete plate (rear surface), the concrete plate (front surface), and the porous ceramic water retainer (dry) is due to the difference in the contact state of the bottom surface of each sample. This is because of the difference between heat transfer and ventilation.

As is clear from the above experimental results, according to the porous ceramic water retainer containing water, the rise of the surface temperature of the sample is suppressed by the latent heat of vaporization of water. Therefore,
By arranging this porous ceramic water retaining body containing water on the surface of the building or the road, it is possible to easily suppress the rise in the surface temperature of the building or the road only by the natural energy of vaporization latent heat of water. That is, especially in the summer
It is possible to suppress the daytime temperature rise in the city and improve the global environment.

Further, according to the porous ceramic water retainer whose upper surface is unglazed, the retained water can be easily vaporized, and the rise of the surface temperature can be suppressed more efficiently.

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above-described embodiment, the rainwater in the water tank 21 is supplied to the water retaining body 10 as the water supply means 20 through the supply pipe 22, but instead of the supply pipe 22, a sprinkler or the like may be used for spraying. You may

Further, in the above embodiment, the valve of the supply pipe 22 is adjusted as necessary, but the valve may be opened and closed at a predetermined time interval or the water retention of the water retention body 10 may be performed. The situation may be detected by a sensor or the like to adjust the valve.

Further, in the above embodiment, the water tank 21
Is placed on the roof of the building, but the water tank is placed on the floor below the roof (that is, inside the building), and a groove for collecting rainwater is formed on the roof and The rainwater may be guided to the water tank and stored by connecting the water tank with a connecting pipe. In this case, the rainwater is supplied to the water retaining body 10 through the supply pipe 22 by pumping up the rainwater in the water tank. According to this, it is possible to obtain the same effect as that of the above-described embodiment without impairing the aesthetics of the building. Further, since the rainwater can be collected from the entire rooftop using the groove formed on the rooftop, the rainwater can be efficiently collected.

In addition, in the above embodiment, the water tank 2
Although the rainwater is replenished from 1 to the water retaining body 10 directly via the supply pipe 22, a filter may be provided in the water tank 21 or the supply pipe 22 to remove dust. According to this, it is possible to prevent the holes formed in the water retaining body 10 from being clogged with dust in rainwater supplied from the water supplying means 20, and it is possible to maintain the water retaining function of the water retaining body 10.

Furthermore, in the above embodiment, the water retainer 10 is formed of porous ceramics, but as is clear from the above experimental example, at least the upper surface (that is, the surface which is not in contact with a building) is formed. It is preferable that the glaze is not applied to the unglazed state. With this configuration, the water retained in the water retaining body 10 can be easily vaporized, and the increase in the surface temperature of the water retaining body 10 can be suppressed more efficiently.

In addition, in the above-described embodiment, only the case where the water retaining body 10 is provided on the entire rooftop of the building has been described, but the present invention provides the water retaining body 10 on a part of the rooftop of the building. May be. Further, the present invention can be applied not only to the roof of a building but also to a part or the whole of the side wall of the building or a part or the whole of the road.

[0048]

As described above, according to the surface temperature improving method of the first aspect of the present invention, the porous water retainer capable of retaining water is arranged at the location where the surface temperature rises upon receiving sunlight. Since water is replenished to the water retainer, the water retained in the water retainer is vaporized by the heat of the sunlight, and the heat amount of the sunlight is replaced by the latent heat of vaporization of the water, so that the amount of latent heat of vaporization of the water is replaced. Only, the rise of the surface temperature of the water retaining body can be suppressed. Therefore, the rise of the surface temperature of the city can be easily suppressed only by the natural energy of vaporization latent heat of water. Furthermore, by applying this method to the entire city, it is possible to suppress an increase in daytime temperature of the city, especially in summer, and to improve the global environment.

According to the surface temperature improving system of any one of claims 2 to 6, a water retainer made of a porous material capable of retaining water is disposed at a location where the surface temperature of the surface rises upon receiving sunlight. Since the water supply means is configured to replenish water to the water retaining body, the water retaining body is always kept in a state of containing water, and the heat quantity by sunlight can be replaced by the latent heat of vaporization of water, It is possible to suppress an increase in the surface temperature of the. Therefore, it is possible to easily suppress an increase in the surface temperature of the city.

Particularly, according to the surface temperature improving system of any one of claims 3 to 6, since the water retention body is arranged on the roof or side wall of the building or on the road, it is called latent heat of vaporization of water. The effect that the rise in the surface temperature of the city can be easily suppressed only by natural energy is exerted.

Further, according to the surface temperature improving system of any one of claims 4 to 6, since the water retainer is made of ceramic, at least the upper surface of which is unglazed, the moisture retained in the water retainer is not changed. Evaporation is facilitated, and the rise in the surface temperature of the city can be suppressed more efficiently.

Further, according to the surface temperature improving system of the fifth or sixth aspect, the rainwater is collected and stored in the water tank, and the rainwater is supplied from the water tank to the water retaining body by the supply means. Therefore, rainwater can be used as a water source, and there is an effect that the surface temperature of a city can be improved only by the natural circulation system without using artificial energy.

Further, according to the surface temperature improving system of the sixth aspect, the water supply means is configured to automatically replenish the water retaining body with water at a predetermined time interval. There is an effect that it is possible to keep the water in a good condition at all times and to effectively suppress the rise of the surface temperature of the city.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a surface temperature improving system according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing a water retaining body of the surface temperature improving system shown in FIG.

FIG. 3 is a layout diagram for explaining a test piece used in an experimental example.

FIG. 4 is a characteristic diagram showing a change over time in the surface temperature of each sample.

FIG. 5 is a characteristic diagram showing changes over time in the temperature difference between the surface temperature and the air temperature of each sample.

FIG. 6 is a characteristic diagram showing a change over time in the temperature difference between the surface temperature of the rooftop concrete plate and the surface temperature of each of the other specimens.

FIG. 7 is a characteristic diagram showing the relationship between the surface temperature of the rooftop concrete plate and the surface temperature of each of the other specimens.

FIG. 8 is a characteristic diagram showing changes over time in weight change of a porous ceramic water retaining body (containing water).

FIG. 9 is a characteristic diagram showing a change with time of a water evaporation amount of a porous ceramic water retaining body (containing water).

[Explanation of symbols]

 10 Water retaining body 20 Water supply means 21 Water storage tank 22 Supply pipe (supply means)

Claims (6)

[Claims] 1. A method for suppressing an increase in temperature of a portion whose surface temperature rises upon receiving sunlight, the method being a porous water retention capable of retaining water in a portion whose surface temperature rises upon receipt of sunlight. By arranging a body, replenishing the water retainer with water, and vaporizing the water retained in the water retainer by the heat of the sunlight, the heat amount of the sunlight is replaced with the latent heat of vaporization of water to the temperature. A method for improving surface temperature, which comprises suppressing an increase in surface temperature at an ascending location. 2. The heat amount of sunlight is formed by a porous body which is arranged at a location where the surface temperature of the sun rises and which can retain water, and which is vaporized by the heat of the sunlight. A surface temperature improvement system comprising: a water retainer that replaces latent heat of vaporization of water; and water supply means that replenishes the water retainer with water and maintains the water retainer in a water-containing state. 3. The surface temperature improving system according to claim 2, wherein the water retaining body is arranged on a roof or a side wall of a building or on a road. 4. The surface temperature improving system according to claim 2, wherein the water retainer is made of ceramic in a predetermined shape, and at least the upper surface thereof is in an unglazed state. 5. The water supply means comprises a water tank for collecting and storing rainwater, and a supply means for supplying rainwater from the water tank to the water retaining body. The surface temperature improving system according to any one of claims 1. 6. The surface according to claim 2, wherein the water supply means automatically replenishes the water retaining body with water at a predetermined time interval. Temperature improvement system.