JPH0777527B2 - Plant cultivation equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant cultivation device,
It is an object of the present invention to provide a complete control type plant cultivation device using a high pressure metal vapor discharge lamp as an artificial light source and having high cultivation efficiency.

[0002]

2. Description of the Related Art A fully-controlled plant cultivation device (hereinafter referred to as a cultivation device) is a plant that cuts natural (sun) light and uses only artificial light to optimize temperature, CO ₂ concentration, air volume, and light intensity for plants.・ Plants are cultivated as a factory by adjusting environmental conditions such as nutrient solution temperature and nutrient solution composition.

In a conventional cultivation apparatus, a high pressure metal vapor discharge lamp such as a high pressure sodium lamp or a metal halide lamp or a fluorescent lamp is used for growing a plant using an artificial light source. In general, the higher the wattage of a high-pressure metal vapor discharge lamp, the better the luminous efficiency. Therefore, a high wattage lamp of 700 W to 1 KW is usually used, and the distance between the upper surface of the cultivation panel and the lamp is set to about 1.5 to 2 m. The use of an umbrella enhances the uniformity of the illuminance distribution on the cultivation panel. In the case of using a fluorescent lamp, unlike the case of using a high-pressure metal vapor discharge lamp, the light output per unit surface area of the light source is significantly small, and since the luminous efficiency is low, a fluorescent lamp is provided almost all over the cultivation panel. It is installed. As for the distance between the cultivation panel and the fluorescent lamp, the heat from the fluorescent lamp is dispersed like the light output, and even if it is brought close to the plant, it is less likely to be adversely affected by the heat. Therefore, it is common practice to provide cultivation panels and artificial light sources in multiple stages to effectively utilize the cultivation space.

In a conventional plant cultivating apparatus using an artificial light source, the artificial light source is located in the same space as the cultivating space, and about 200 W per 1 m ² of cultivated surface is required to obtain an illuminance of, for example, 15 to 20 Klx necessary for plant growth. It requires lamp power. Of the energy emitted by artificial light sources, the energy used for photosynthesis in plants is small, and most of it is eventually converted to heat. Therefore, various methods for reducing the heat from the artificial light source have been tried.

FIG. 4 shows an example of a conventional method of exhausting heat from an artificial light source. A high-pressure metal vapor discharge lamp 2 is installed as an artificial light source in the reflection shade 21 so that light is emitted downward. Air outlet 22 for the reflector 21
Further, an exhaust port 23 is provided, and a transparent glass plate 23 is airtightly attached to the lower opening, and the artificial light source is exhausted by sending air from the blower hole 22.

[0006]

In a conventional plant cultivation device using an artificial light source, in order to adjust the temperature inside the cultivation chamber to a constant temperature suitable for plant cultivation, a large amount of heat is released from the artificial light source into the cultivation chamber. There is a problem that it is necessary to perform air conditioning with a large-capacity air conditioner, and the initial facility cost and maintenance power cost are large. In a plant cultivation device using a high-pressure metal vapor discharge lamp, a relatively high distance is provided between the high-pressure metal vapor discharge lamp and the cultivation panel surface in order to prevent an adverse effect of heat from the light source on the plant although the energy utilization efficiency is high. Therefore, there are drawbacks that the cultivation space becomes large, the efficiency of plant cultivation is poor, the air-conditioning cost, the construction cost of the cultivation device, etc. are high.

Further, in the conventional heat exhausting method as shown in FIG. 4, the space in the reflecting shade is relatively large, and if an attempt is made to obtain a sufficient heat exhausting effect, the amount of power consumption for increasing the amount of blast air is large. Needed a large capacity blower. Further, when a glass plate is provided on the front surface of the reflection shade, a light component having a small incident angle with respect to the glass plate out of the light reflected on the inner surface of the reflector is reflected on the glass surface and the light is not emitted to the outside. Therefore, the glass plate is not provided. Compared with the case, the transmission loss of the light emitted from the reflector is 10 ~
Since it is 20%, it is necessary to increase the number of lights of the artificial light source or increase the lamp power by that amount, and these are not effective methods.

[0008]

The present invention uses a high pressure metal vapor discharge lamp as an artificial light source in a plant cultivation device,
It is obtained by the high-pressure metal vapor discharge lamp substantially concentrically covered in between outer bulb and the transparent glass cylinder with transparent tube to the outer sphere of the channeling air, external surface area of the outer sphere of the high-pressure metal-vapor discharge lamp The lamp power is 1 W / cm ² or more and the air flow rate is 0.3 L / min · W or more per lamp power, and the temperature of the exhaust air is preferably 1 than the temperature of the blown air.
The temperature is raised in the range of 5 to 30 ° C.

[0009]

The plant cultivating apparatus according to the present invention uses a high pressure metal vapor discharge lamp capable of considerably reducing the appearance of the lamp per power consumption of the lamp as compared with a fluorescent lamp. The heat from the light source can be easily removed by covering the transparent cylinder with a substantially concentric circle and flowing air between them. The outer surface temperature of the outer bulb is increased by setting the lamp power per outer surface area of the outer bulb of this high-pressure metal vapor discharge lamp to 1 W / cm ² or more, and the air flow rate is 0.3 L / min per lamp power. By setting the temperature of W or higher or the temperature of the exhaust air to be higher than the temperature of the blown air in the range of 15 to 30 ° C., it is possible to effectively exhaust heat (heat exchange) with a small amount of blown air.

Further, the high-pressure metal vapor discharge lamp and the transparent tube are substantially concentric with each other, and the light emitted from the high-pressure metal vapor discharge lamp has a large incident angle to the transparent tube and is hardly reflected on the surface of the transparent tube, and the transparent tube is Since it is small and the thickness of the tube can be reduced, the transmission loss of light due to the transparent tube can be reduced.
In addition, since the heat from the high-pressure metal vapor discharge lamp can be effectively removed significantly, it is easy to reduce the size of the high-pressure metal vapor discharge lamp, the reflector, etc. The distance can be shortened.

[0011]

EXAMPLES The present invention will be described below with reference to preferred examples.

FIG. 1 is a schematic sectional view of a cultivation room using the plant cultivation device according to the present invention. A high-pressure metal vapor discharge lamp 2 composed of a high-pressure sodium lamp is mounted in a transparent glass tube 4 via a lamp holder 3 on the ceiling of the plant cultivation device 1.

The inside of the cultivation room is shut off from the outside air with the transparent glass tube 4 as a boundary, and the outside air can be easily exhausted by blowing the outside air between the transparent glass tube 4 and the high-pressure metal vapor discharge lamp 2 with a 20 W blower 5. It is like this. Vegetables such as salad vegetables and lettuce planted with radiant light from the high-pressure metal vapor discharge lamp 2 on the cultivation panel 7 by the reflection shade 6 provided on the ceiling of the cultivation room and the high-light reflecting material attached to the side surface of the cultivation room. 8 is efficiently irradiated. The distance between the high-pressure metal vapor discharge lamp 2 and the upper surface of the cultivation panel 7 is as short as about 1 m, and the average illuminance on the upper surface of the cultivation panel 7 is 22 Klx.

In addition to the light components of the artificial light source, the type of artificial light source used is a major factor in the light conditions for economically growing the plant. In order to improve the utilization efficiency of the plant cultivation space, if the distance between the ceiling surface and the upper surface of the cultivation panel 7 is shortened, the distance between the high pressure metal vapor discharge lamp 2 and the upper surface of the cultivation panel 7 is naturally shortened. One of the light irradiation methods in this state is to use a large number of small, low-wattage lamps of about 70 W or 100 W to disperse heat and light from the lamps. In this method, there is a method of using a fluorescent lamp as an artificial light source. Similarly, this is not a preferable method because the facility cost increases due to the increase in the number of installed lights and the lighting power cost increases due to the decrease in luminous efficiency, which increases the production cost of the plant to be cultivated. Therefore, it is preferable to use a high-wattage, high-pressure metal vapor discharge lamp having a high luminous efficiency as much as possible, and a 660 W high-pressure sodium lamp is used in this embodiment.

FIG. 2 is a schematic enlarged view of the high pressure metal vapor discharge lamp 2, the transparent glass tube 4 and the like shown in FIG. The outer diameter of the outer bulb 9 of the high-pressure metal vapor discharge lamp 2 is about 55 mm, and the lamp power per outer surface of the outer bulb 9 is about 1.6 W / cm ² , which is more than that used in conventional general lighting. It is more than double and the volume ratio of the outer sphere is about 1/4 or less. The larger the lamp power value per surface area of the outer bulb, the higher the surface temperature of the outer bulb 9,
The temperature difference from the outside air becomes large and it becomes easy to exhaust heat. Also,
Since the outer bulb 9 can be made small, the thickness of the glass of the transparent glass tube 4 is thin at 1.5 mm and the inner diameter is thin at about 85 mm. The transparent glass tube 4 is attached so as to be substantially concentric with the high-pressure metal vapor discharge lamp 2, and since the transparent glass tube 4 may be thin, about 95% of the light from the high-pressure metal vapor discharge lamp 2 is emitted. To Penetrate. The outside air is blown into the gap between the outer bulb 9 and the transparent glass tube 4 from the blow-out port 10 by the fan 5, and is discharged to the atmosphere from the exhaust port 11. A filter to prevent dust and insects from entering the air supply and exhaust parts.
Is provided.

Next, as the high-pressure metal vapor discharge lamp 2, 660 W
Table 1 and FIG. 3 show the experimental results showing the relationship between the amount of air blown from the outside air and the amount of exhaust heat with respect to the combination of the outer diameter of the outer bulb 9 and the inner diameter of the transparent glass tube 4 using the high pressure sodium lamp of FIG.
In Table 1 and FIG. 3, the same numbers indicate the results under the same conditions.

[0017]

[Table 1] As can be seen from this result, the smaller the outer diameter of the outer sphere 9,
In addition, the outer glass 9 becomes thin, so that the transparent glass tube 4
The smaller the inner diameter of, the greater the heat removal effect can be obtained with a smaller air flow rate. As the amount of blown air increases, the power cost required for the blower increases, and the equipment cost for air cooling increases as compared to the method that does not perform air cooling, and the effect only decreases as the size of the device increases. Therefore, it is necessary to suppress the amount of blown air as much as possible, and in the method and apparatus according to the present invention, the outer bulb 9 is forcibly blown with the outer air so that the outer bulb has a lamp power value per surface area exceeding that of the conventional design. No problem occurs in the heat resistance of the glass of No. 9. However, if the outer diameter of the outer sphere 9 is made too small, the surface area of the outer sphere is reduced, so that the heat exchange with the air is deteriorated and the exhaust heat effect is not improved so much. In order to obtain an efficient exhaust heat effect with a small air flow rate, it is preferable to set the lamp power per outer surface area of the outer bulb at which the exhaust heat amount tends to be saturated with respect to the air flow rate to 1 W / cm ² or more. There is at least 50% or more exhaust heat effect with respect to the substantially saturated value of exhaust heat under this load. Unless the air flow rate is 0.3 L / min · W or more, the outer bulb and glass tube are small and compact, which is abnormal. In addition, the temperature of the outer bulb and the glass tube itself rises, causing a problem in heat resistance, and the temperature of the glass tube rises and heat radiation increases, which adversely affects plants. Moreover, these things appear in the rise value of the temperature of the exhaust air, and the air flow rate is 0.3 L / min.W.
At this time, the temperature rise value of the exhaust air with respect to the blown air is about 30
Blow rate 1.2L / when the exhaust heat amount is about 90% of the saturation value
It was about 20 ° C. at min.W, and about 15 ° C. at an air flow rate of 1.8 L / min.W when the exhaust heat amount was substantially saturated. If the temperature rise value of the exhaust air is 15 ° C. or less, the amount of air blown is excessive and it is wasteful. Therefore, the temperature rise value of the exhaust air with respect to the blown air in the efficient exhaust heat method needs to be in the range of 15 to 30 ° C. For these measurements, combinations other than those shown in Table 1 were used, and other lamps having different sizes such as 360 W and 940 W, or a transparent glass tube having openings at both ends were used to blow air from one opening and exhaust from the other opening. Was almost the same result. In this embodiment, glass is used as the transparent cylinder, but since it is forcibly cooled,
For heat resistance, translucent acrylic or the like can be applied. In order to further enhance the heat exhaustion effect, a transparent tube may be provided with an infrared reflection / absorption film, or a material for reflecting / absorbing infrared rays from a lamp may be added to the material of the transparent tube itself, and similarly, the growth of plants may be increased. Ultraviolet rays from the metal vapor discharge lamp, which has a suppressing effect, may be reflected and absorbed by providing a film of, for example, zinc oxide on the surface of the transparent cylinder. In the method of reflecting and absorbing infrared rays and ultraviolet rays by this transparent tube, the temperature of the transparent tube can be lowered, so that the margin of material selection with respect to the heat resistance of the reflection and absorption materials is increased, and the life characteristics of reflection and absorption performance are also improved. Can be excellent.

[0018]

As described in detail above, the plant cultivation apparatus according to the present invention can remove much of the heat from the artificial light source easily and economically, so that the initial equipment cost required for air conditioning,
Maintenance power costs can be reduced significantly.

Further, since the heat of the high-pressure metal vapor discharge lamp on the plants is small and the distance between the plants can be shortened, the height per stage can be reduced in the multi-stage cultivation apparatus, and the space utilization efficiency of plant cultivation can be further improved. This has the advantage that the initial plant cost related to the building, or the electric power cost required for air conditioning can be further reduced with respect to the increased plant cultivation capacity. In addition, since it is possible to use a high-wattage high-pressure metal vapor discharge lamp as an artificial light source, it is easy to obtain the illuminance required for plant growth, and it has high efficiency and high output characteristics and excellent life characteristics. Therefore, the number of lights installed with artificial light sources can be reduced.

In addition, the transparent cylinder reflects infrared rays and ultraviolet rays,
By adding the absorbing function, it becomes easy to use a high pressure mercury vapor lamp with a lot of ultraviolet rays as a high pressure metal vapor discharge lamp, a metal halide lamp, or a high color rendering high pressure sodium lamp with a lot of infrared rays as a lamp for plant cultivation, for example, a metal halide lamp. In, the photosynthetic efficiency can be improved by several tenths by lowering the ultraviolet rays.

As described above, according to the present invention, it is possible to reduce operating costs such as air-conditioning costs, initial equipment costs, and lighting costs. Therefore, it is possible to widely spread the plant-cultivating apparatus using artificial light sources, in particular, for the widespread use. Is big.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a cultivation room using a plant cultivation device according to the present invention.

FIG. 2 is a schematic enlarged view of the high-pressure metal vapor discharge lamp, water-cooled tube and the like shown in FIG.

FIG. 3 shows experimental results on the relationship between the amount of outside air blown and the amount of exhaust heat with respect to the combination of the outer diameter of the outer bulb 9 and the inner diameter of the transparent glass tube 4 using a 660 W high-pressure sodium lamp as the high-pressure metal vapor discharge lamp 2. The figure shown.

FIG. 4 is an example of a conventional heat exhausting method using a metal vapor discharge lamp as an artificial light source.

[Explanation of symbols]

 1 Plant cultivation device 2 High pressure metal vapor discharge lamp 3 Lamp holder-4 Transparent glass tube 5 Blower 6 Reflector 9 Outer bulb

Claims (1)

[Claims] 1. A high-pressure metal vapor discharge lamp is used as an artificial light source, and a transparent tube is substantially concentrically covered on the outer bulb portion of the high-pressure metal vapor discharge lamp so that air flows between the outer bulb portion and the transparent tube.
The outer surface area of the outer bulb of a high pressure metal vapor discharge lamp.
Power is 1 W / cm ² or more, and the flow rate of air is
A plant cultivating device characterized by a force of 0.3 L / min · W or more .