JP2008086284A - Material for natural lighting for agricultural and horticultural hot house, and agricultural and horticultural hot house - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for natural lighting for an agricultural hot house, which prevents abnormal increase in temperature in a hot house even under strong sunshine so that the temperature in the hot house is prevented from being affected by change of outside temperature as slight as possible. <P>SOLUTION: The material for natural lighting for an agricultural and horticultural hot house is structured as follows: a transparent panel 20 is provided at the roof part 3b of a house 1; a heat-shielding layer 21 is formed on the inner surface of the transparent panel 20; and a hydrophilic layer 22 is formed on the outer surface. The heat-shielding layer 21 is set in order to reflect infrared light included in solar light into the house 1 through the roof part 3b so as to transmit visible light and ultraviolet light, and is composed of a dielectric multi-layer film composed of alternate layers of Ta205 (tantalum oxide) thin film and SiO2 (silica) thin film. The hydrophilic layer 22 is provided in order to impart hydrophilic property to the surface of the transparent panel 20, and is formed by directly applying the coating material consisting mainly of TiO2 to the surface of the transparent panel 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a daylighting material mounted on a house used for agriculture, horticulture, and the like, and an agricultural and horticultural house using the daylighting material.

  Greenhouses and plant cultivation rooms used for the cultivation of agricultural products and gardening of flowering trees and foliage plants have a framework structure made of aluminum pipes, steel frames, wood, etc. In addition, an opening / closing door and an opening / closing type window are provided at appropriate portions. Here, in order to promote the growth of plants, sunlight is required together with temperature and humidity. Therefore, the outer wall and the roof covering the framework structure are provided with a daylighting material on almost the whole. As this daylighting material, a transparent sheet material made of vinyl chloride, polyolefin or the like, a panel material made of a transparent resin such as polycarbonate, or a transparent plate made of a glass plate is generally used.

  By the way, as in the fine weather in summer, the internal temperature of the greenhouse may become extremely high due to strong sunshine, and on the contrary, the growth of the plant is inhibited, and in severe cases, it may wither. By providing a window that can be opened and closed in the greenhouse and opening this window, the internal heat can be released. However, the temperature inside the greenhouse does not fall below the outside air temperature simply by opening the window. For this reason, air conditioning facilities installed in greenhouses have also been put into practical use so that when the temperature inside the greenhouse rises extremely, the inside temperature can be lowered by cooling the inside. Become. However, when an air conditioning facility is attached to a greenhouse, there are problems such as high manufacturing cost of the greenhouse facility, large size, and high running cost.

From the above, Patent Literature 1 discloses a plant cultivation room that has a simplified configuration and enables energy-saving operation. In this known plant cultivation room, a skylight in a building is configured as a transparent double layer in which a heat ray absorbing liquid is enclosed, and flowing water is supplied to the outer surface thereof. Then, the heat absorbed by the heat ray absorbing liquid is released to the outside together with the latent heat of vaporization of running water.
JP 58-107122 A

  By the way, as mentioned above, if the heat ray irradiated from sunlight is absorbed in the heat ray absorbing liquid, the heat ray absorbing liquid is heated, and the skylight is stored. Due to this influence, the temperature in the plant cultivation room rises. For example, under the hot weather in summer, there may be a case where sufficient temperature control cannot be performed only by heat of vaporization. In addition, in order to release the heat absorbed by the heat ray absorbing liquid to the outside as latent heat of vaporization, it is necessary to sufficiently spread water over the entire skylight and slow down the flow speed. The water thus deposited does not stay on the surface of the skylight, but quickly flows down along the slope, and hardly evaporates on the surface of the skylight, so that a sufficient heat radiation effect may not be obtained. Furthermore, even in the winter when the irradiation energy of sunlight is extremely small and the plant cultivation room does not rise to the desired temperature, heat rays are absorbed, and the room temperature cannot be raised to the extent necessary for growing a specific plant. In some cases.

  The present invention has been made in view of the above points, and the object of the present invention is to prevent the temperature inside the house from becoming abnormally high even under intense sunlight, and the inside temperature of the house can be changed to the outside temperature. It is to be able to suppress the influence as much as possible.

  In order to achieve the above-described object, the present invention provides a daylighting material used in an agricultural and horticultural house in which internal temperature control is performed, and a redlighting material main body made of a transparent sheet or a transparent plate is provided on one side surface. It is characterized in that a heat shielding layer that reflects external light and transmits visible light and ultraviolet light is formed.

  Sunlight contains visible light, ultraviolet light, and infrared light, and visible light, especially from the green and blue wavelength regions to the ultraviolet light region, is required for pollination by insects such as bees and butterflies. In addition, from the viewpoint of plant photosynthesis, light having a wavelength of 400 to 700 nm is required. Accordingly, light in these wavelength regions is transmitted through the daylighting material. On the other hand, since the infrared light heats the inside of the house, the daylighting material should not be transmitted. Moreover, in order to prevent the daylighting material itself from accumulating heat, infrared light is not absorbed but reflected. That is, the daylighting material has a characteristic of transmitting visible light from ultraviolet light and reflecting infrared light. In order to exert this characteristic, a heat insulating layer is formed on the surface of the lighting material body made of a transparent plate made of a transparent resin sheet such as vinyl chloride or polyolefin, a transparent resin plate such as polycarbonate or a glass plate, or a glass plate. To do. The heat shielding layer can be attached to the daylighting material in the form of a film, or can be formed by film forming means such as vacuum deposition.

  The heat shielding layer can be composed of a dielectric multilayer film in order to have a function of transmitting light in a desired wavelength region and reflecting light of other wavelengths. Specifically, the heat shield layer is composed of a dielectric multilayer film in which Ta2O5 thin films and SiO2 thin films are alternately formed, and has a wavelength selectivity that reflects infrared light in sunlight and transmits visible light and ultraviolet light. That is, an IR cut mirror film that reflects infrared light is formed. This heat shielding layer is laminated on one side surface of the lighting material body.

  In general, the dielectric multilayer film changes its transmission characteristics according to the incident angle of light. In the case of constituting as a daylighting material, it is advantageous to use a dielectric multilayer film having an angle dependency as the heat shielding layer. In other words, the sunlight in the summer is vertical or close to it, and in the winter the sun is radiated from a more horizontal angle, so the characteristics of the dielectric multilayer film and the roof of the roof when assembled as an agricultural and horticultural house From the angle, the incident angle of sunlight in the hot summer season reflects infrared light as much as almost 100%, but actively captures infrared light in the winter when the temperature in the house does not rise so much For this reason, it is desirable to have a characteristic of actively transmitting infrared light with respect to the incident direction of sunlight in winter.

  The daylighting material is used at least as a roofing material in an agricultural and horticultural house. The heat shield layer in this daylighting material may be provided on either side of the daylighting material body, but in order to protect it from deterioration or damage, it should be directed to the inside of the house with good environmental conditions. It is desirable to install. And it can be set as the structure which forms a hydrophilic layer in the other side of this lighting material main body, ie, the outer surface of a house. This hydrophilic layer can be composed of TiO2 or hydrophilic silicone as a main component, and can be formed on the outer surface of the daylighting material body by means such as coating including film formation or attaching a film. In addition, even if the hydrophilic layer is provided on the same surface as the heat shielding layer in a laminated state, there is no optical problem.

  The daylighting material having the above configuration is configured as at least a roof that constitutes an agricultural and horticultural house. On the other hand, the side surface, the window, and the opening / closing door are also made of a transparent daylighting material. However, since these side portions, windows, and doors are also irradiated with sunlight containing infrared light, it is desirable to laminate a thermal barrier layer that reflects at least infrared light on these lighting materials.

  Although the roof can be arranged in a flat state, it is desirable that the roof is mounted so as to be inclined at a predetermined angle. In particular, when a hydrophilic layer is formed on the surface of the daylighting material and this daylighting material is used as a roof, the house should be allowed to flow water along this slope, and the flowing water should be vaporized. In addition to the cut by reflection of infrared light by the heat shield layer, it exhibits a cooling effect by heat of vaporization. Note that it is not always necessary to form a hydrophilic layer on the daylighting material body because the peripheral wall portion on the side surface does not have sufficient water retention when flowing, and the effect of vaporization heat cannot be expected to be large. However, since water droplets can be adhered to this side surface, it exerts some action of heat of vaporization (latent heat of vaporization), and the hydrophilic layer is formed on the side surface portion from the viewpoint of preventing surface fouling. Can also be formed.

  Infrared light, which is heat rays from sunlight radiated in the sun, is reflected by at least a heat-shielding layer provided on the roof, and transmits visible light and ultraviolet light so that the temperature in the house does not become abnormally high. It is possible to create an optimal environment for plant growth, and it can be suitably used as a greenhouse for growing seasonal vegetables that do not like heat, and for growing plants such as orchids that require constant temperature. . And, by forming the heat shield layer with a dielectric multilayer film, it can have the desired transmission / reflection characteristics, so that the fluctuation range of the internal temperature of the house with respect to the change of the outside temperature can be reduced, and cultivation A good environment can be given by the growth of plants.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the external appearance of the agricultural and horticultural house 1 is shown in FIG. In the figure, a house 1 is composed of a building 2 with a building structure 3 installed on a foundation 2, and the building structure 3 has a peripheral wall 3a and a roof 3b, and is a pillar formed of a steel frame, an aluminum pipe, or the like. It has a skeleton structure composed of a frame or the like on which a window or a door is mounted. A side plate made of a transparent plate (or transparent sheet) is attached to this framework structure, and an opening / closing window 4 and an opening / closing door 5 are provided at appropriate locations. Further, a roof plate (or sheet) made of a transparent plate (or transparent sheet) is mounted on the roof portion 3b. Further, the opening / closing window 4 and the opening / closing door 5 of the peripheral wall portion 3a are both fitted with a window plate and a door plate made of a transparent member, whereby the inside can be closed. The interior of the house 1 is a field for growing crops. In addition, when comprising as a greenhouse for growing a flowering tree and a houseplant, the cultivation shelf in which a flower pot etc. are mounted is provided.

  As shown in FIG. 2, an irrigation facility is provided inside the house 1. The irrigation facility includes a water storage tank (not shown) provided in the basement, a pumping pump unit 10 connected to the water storage tank, and a water spray tube connected to the pumping pump unit 10 and extending along the ridge 11. 12. In addition, a supply pipe 13 is connected to the pumping pump unit 10, and this supply pipe 13 is connected to a water supply pipe 14 disposed in an extending direction of the top portion at an upper position of the top portion of the roof portion 3 b. Is provided. As is apparent from FIG. 3, the water supply pipe 14 has a plurality of outflow small holes 14a formed in the longitudinal direction, so that water can flow down from the outflow small holes 14a over the entire roof portion 3b. ing.

  In the present embodiment, the daylighting material for the peripheral wall portion 3a and the roof portion 3b is made of a transparent plate, and the window plate and the door plate are also daylighting materials through which light passes. As shown in FIG. 3, the roof portion 3 b has a transparent panel 20 made of a transparent synthetic resin plate such as transparent glass or polycarbonate as a daylighting material body, and on one side of the transparent panel 20. A heat shield layer 21 is formed, and a hydrophilic layer 22 is formed on the other side surface. The transparent panel 20 is mounted on the roof portion 3b so that the hydrophilic layer 22 faces the outer surface and the heat shield layer 21 faces the inner side.

  In FIG. 3, the heat shielding layer 21 reflects the infrared light IR (shown by a solid line) included in the sunlight SL from the roof portion 3 b into the house 1, and visible light VL and ultraviolet light shown by a one-dot chain line. UV is for transmitting, and is composed of alternating layers of Ta 2 O 5 (tantalum oxide) thin film and SiO 2 (silicon dioxide) thin film, that is, a dielectric multilayer film, and is formed by film forming means such as vacuum deposition. The transmission wavelength characteristics by the heat shielding layer 21 are as shown in FIG. In the figure, the solid line indicates transmitted light and the reflected light is indicated by a dotted line. Therefore, the heat shielding layer 21 has a transmittance of 90% or more for visible light and ultraviolet light, that is, light having a wavelength of 350 to 700 nm, and most of light having a wavelength exceeding the wavelength of the dotted line 750 nm is reflected, and particularly, the wavelength of 850 nm. Then, it exhibits the characteristic of reflecting almost 100%. As a result, sufficient transmittance is obtained for wavelength light necessary for plant pollination and photosynthesis, and infrared light as heat rays, particularly light having a wavelength of 850 nm or more is reflected and is not taken into the house 1. .

  Thus, by providing the heat shielding layer 21, in the roof portion 3b of the house 1, when sunlight rays enter from the direction of the arrow SL in FIG. 3, visible light VL and ultraviolet light UV are transmitted, but infrared light is transmitted. The light IR will be reflected. Here, as the internal temperature of the house 1, the infrared light IR is reflected so as not to become an abnormally high temperature in summer when strong sunlight is irradiated. On the other hand, in order to keep the internal temperature of the house 1 higher than the outside air temperature at night in winter, as shown by a dotted line in FIG. Contain and prevent heat from being released into the atmosphere. In other words, the inside of the house 1 is thermally shielded from the atmosphere as much as possible to reduce the influence of changes in the external temperature of the house 1 and to suppress the fluctuation of the internal temperature of the house 1 as much as possible. . The heat shield layer 21 has substantially the same characteristics in the range where the transmittance / reflectance is about 90 ° to ± 30 °, and a smaller angle, that is, the incident direction of sunlight in winter (FIG. 3). The direction indicated by the phantom line arrow) has a characteristic that transmits infrared light to some extent, that is, a characteristic that shifts the wavelength at which the ratio of transmission and reflection changes to the short wavelength side. it can.

  Moreover, the hydrophilic layer 22 provided in the transparent panel 20 imparts hydrophilicity to the surface of the transparent panel 20 so that when water is attached, it forms a water film and diffuses widely. That is, it is a layer that exhibits the function of reducing the contact angle. Specifically, it can be formed by directly applying a coating material mainly composed of TiO2 to the surface of the transparent panel 20. And if water is made to flow out from the small hole 14a for the outflow of the water supply pipe 14 installed in the top part of the roof part 3b, while flowing down the roof part 3b, the water film covering the whole surface will be formed. In this way, the supplied water is diffused along the roof portion 3b, so that the water holding capability is increased, and the substantially entire surface of the roof portion 3b is kept wet. Therefore, water vapor is generated according to the surrounding humidity conditions, humidifying the air, and the roof portion 3b is cooled by the action of the latent heat required to humidify the air to the saturated state. And even if external air is a high humidity condition, the temperature fall of about 1 to 2 degree | times is obtained, and if it is a low humidity state, a cooling effect will become still higher.

  By comprising as mentioned above, it can suppress that the internal temperature of the house 1 raises abnormally under the strong sunlight in the summer. That is, the temperature change in one day between one part of the roof formed with a vinyl chloride sheet and the other part formed with a dielectric multilayer film exhibiting the characteristics of FIG. 4 on the vinyl chloride sheet. An example is shown in FIG. In the figure, a curve p indicated by a thin line is a temperature change of a vinyl chloride sheet without a heat shield layer, and a curve q indicated by a thick line is a temperature change of the vinyl chloride sheet with a heat shield layer. FIG. 6 shows a temperature difference between the curve p and the curve q.

  As is clear from these figures, the temperature change curve of the sheet that has been treated to reflect the infrared light IR during the sunshine hours (6: 00 to 19:00) in which the sunlight including the infrared light IR is irradiated. q is held at a temperature lower than the temperature change curve p of the sheet not subjected to the infrared light IR reflection treatment. In particular, in the time zone in which the sunshine is the strongest and the house temperature is the highest, that is, from 9:00:00 to 16:00, the temperature difference is 3-4 degrees.

  Accordingly, like the house 1, by forming the heat shield layer 21 made of a dielectric multilayer film on the transparent panel 20 constituting the entire roof portion 3b, the same processing is performed on the transparent panel constituting the side surface portion. By applying, the maximum temperature in the house can be remarkably lowered as compared with the case where the house is formed of a transparent member that does not have a function as a heat shield layer. In particular, the temperature reduction effect is exerted during the daytime in summer when the sun rays containing a large amount of infrared light IR are irradiated, and the temperature does not become abnormally high. Further, a hydrophilic film 22 is formed on the roof portion 3b, and water is supplied from the water supply pipe 14 onto the hydrophilic film 22 to form a water film so as to cover almost the entire surface. Therefore, a further temperature reduction is achieved by the action of the heat of vaporization of water. Moreover, the internal temperature of the house 1 can be adjusted by performing ON / OFF control on the supply of water from the water supply pipe 14.

  As a result, the internal temperature of the house 1 can be accurately managed without providing an air conditioning facility or the like. In particular, the maximum temperature in the house 1 in the summer is lowered, so that it is not possible to cultivate in the summer, or is inappropriate for cultivation, such as strawberries, tomatoes, etc., and crops that require proper cultivation temperature management, such as Can grow melons. Moreover, since visible light and ultraviolet light are transmitted, there is no problem with respect to crop growth, ie, photosynthesis and pollination.

  Here, the heat shielding layer 21 laminated on the transparent panel 20 is directed to the inside of the house 1, and therefore is not exposed to wind and rain, and is not damaged by flying objects, etc., and has a stable function over a long period of time. Protected to demonstrate. On the other hand, since the hydrophilic film 22 is formed on the outer surface of the house 1, damage or deterioration may occur, and the hydrophilic function may be deteriorated for a long period. In such a case, the hydrophilicity can be given again by spraying a hydrophilic chemical solution or the like.

  By forming the heat-insulating layer 21 on the inner surface of the roof portion 3b and the inner surface of the transparent panel constituting the peripheral wall portion 3a in the house 1, it is possible to exhibit the heat-retaining function in the house 1 at night in cold weather. . That is, as shown in FIG. 3, geothermal heat TH is radiated from the ground inside the house 1, but the geothermal TH is composed of heat rays, and the heat shield layer 21 has a function of reflecting the heat rays. . Therefore, it is possible to prevent the geothermal TH from being radiated by the action of the heat shielding layer 21, and to confine this heat inside the house 1. As a result, the heat insulating layer 21 exhibits a heat retaining function in the house 1. Further, by forming the heat shield layer 21 of the transparent panel 20 in the roof portion 3b with a dielectric multilayer film, the transmission / reflection characteristics of the infrared light IR are changed according to the incident angle of the sunlight to the roof portion 3b. be able to. In the summer, the roof portion 3b is irradiated with sunlight from almost above, and in the winter, the sunlight is incident on the roof portion 3b from an oblique direction. Therefore, the heat shielding layer 21 has the transmission / reflection characteristics shown in FIG. 4 with respect to the direction of the sunlight in the summer, and with respect to the direction of the sunlight in the winter indicated by an imaginary line arrow in FIG. Can actively transmit infrared light. Thereby, the interior of the house 1 is kept in a constant temperature state to some extent regardless of the season.

It is an external view of the agricultural and horticultural house showing an embodiment of the present invention. It is sectional drawing of the agricultural and horticultural house of FIG. FIG. 3 is an enlarged view of the roof portion of FIG. 2 and an explanatory diagram showing light transmission / reflection characteristics. It is a diagram which shows the permeation | transmission / reflection characteristic of the light by a heat shielding layer. It is a diagram which shows the temperature change of what formed a part of roof part with the sheet | seat of vinyl chloride, and what formed the dielectric multilayer film in the vinyl chloride sheet. It is a diagram which shows the temperature difference of a vinyl chloride sheet and the vinyl chloride sheet in which the dielectric multilayer film was formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 House 3 Building structure 3a Perimeter wall part 3b Roof part 14 Water supply pipe 20 Transparent board 21 Heat insulation layer 22 Hydrophilic layer

Claims (6)

Daylighting material used in agricultural and horticultural houses where internal temperature control is performed,
An agricultural and horticultural house characterized in that a heat shielding layer that reflects infrared light and transmits visible light and ultraviolet light is formed on one side of a daylighting material body made of a transparent sheet or a transparent plate. Daylighting material. 2. The daylighting material for an agricultural / horticultural house according to claim 1, wherein the heat shielding layer is composed of a dielectric multilayer film composed of alternating layers of Ta2O5 thin films and SiO2 thin films. The daylighting material for an agricultural or horticultural house according to claim 1 or 2, wherein a hydrophilic layer is formed on the other side surface of the daylighting material main body. The hydrophilic layer is composed mainly of TiO2 or hydrophilic silicone, and is formed on the outer surface of the lighting material body by any means of coating or pasting. Daylighting materials for the described agricultural and horticultural house. An agricultural and horticultural house using the daylighting material according to any one of claims 1 to 4 as at least a roof and mounting the heat shielding layer of the daylighting material toward an inner side. 6. The agricultural and horticultural house according to claim 5, wherein the roof is provided with watering means.

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