JPH0728613B2 - Plant growing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plant growing apparatus, and in particular, it is suitable for a wall structure having excellent heat insulating properties, heat collecting properties, and heat shielding properties. The present invention relates to a plant growing device.

[Conventional technology]

A plant growing device that constitutes a plant growing space region by a wall body panel relating to a wall body, for example, in a greenhouse, etc., in general, most of the wall bodies are made of the same material for all wall surfaces, and more than one When using different kinds of wall bodies, there are at most two types of wall body panel configurations. The latter example is a so-called concentrating greenhouse in which a reflective wall panel is installed on the north side wall of the greenhouse.

The basic structure of the wall of the plant growing device is, for example, the technique described in Japanese Patent Laid-Open No. 59-55129, or the Proceedings of the 1984 Conference on Agricultural Facilities, p.53-56, Kazuhiko Abe, Nara. Makoto, "Study of transparent heat insulation wall", technology announced on July 31, 1984 is known.

[Problems to be Solved by the Invention]

Greenhouses are required to be warm in winter, cool in summer, convenient, maintenance-free and clean. However, in the above-mentioned conventional technology, if one requirement is satisfied, the other requirement is not satisfied, and the requirement as a whole cannot be met. For example, a light-shielding device is required in summer and a heat-retaining curtain is required in winter. Therefore, the functions of daylighting, heat insulation, heat shielding, and heat collection can be strengthened or added depending on the time. Therefore, there is a problem that it is extremely complicated and is easily soiled.

By the way, generally, when sunlight (hereinafter referred to as "sunlight") shines into the room during the day and hits the plant body with near-infrared rays, the plant is forced to perform extra evapotranspiration, causing fatigue and impeding growth. It It also wastes water. Also,
This near-infrared ray will eventually accumulate in the room as heat,
There is a problem that the cooling means for eliminating this is forced to be added.

The present invention has been made to solve the above-mentioned problems of the prior art, and maximizes the heat collection efficiency in winter, and therefore has excellent heat insulation, and maximizes the heat shield efficiency in summer, and is inexpensive and simple. It is an object of the present invention to provide a plant growing device having a wall structure.

Another object of the present invention is to maintain good growth without excessive heat stress on the plant body during the daytime, and during the daytime, because there is no accumulation of extra heat in the room, and cooling is achieved. It is to provide a plant growing device that can reduce the load.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the configuration of the plant growing device according to the present invention is a plant growing device in which a plurality of types of wall bodies are combined to form a plant growing space, and the plurality of types of wall bodies are plant growing plants. In the north-south cross section of the device, it is assumed that it is divided into a south surface wall body, a roof surface wall body, and a north surface wall body, and the south surface wall body is a complete transmission type wall body or a sunlight transmitting / infrared reflection type wall body, A visible light transmitting / near infrared reflecting wall is used for the face wall, and a perfect reflection wall is used for the north face wall.

[Action]

With the above wall structure, in the winter, the solar energy is sufficiently incident from the south wall, and the indoor light quantity is increased by the reflection on the north wall, and the roof wall and the north wall are also increased. Since the heat insulation by the body is great, the heat collection efficiency as a greenhouse is great, and at the night, the heat insulation effect of each wall is great, so that the heat retention is good.

On the other hand, during the daytime in summer, the inside of the room gets cooler due to the heat shielding effect of the roof wall.

By the way, the sun's rays are roughly made up of visible rays and near-infrared rays, and each has a ratio of 50%. Visible light is essential for the photosynthetic activity of plants.

Due to the high altitude of the sun in summer, the incidence on the greenhouse is mainly from the roof.

At this time, since there is excess heat energy, the near infrared rays are unnecessary. Therefore, if a visible light transmission / near infrared reflection type wall is installed on the roof surface, the visible light necessary for plant growth will be transmitted, giving extra heat stress to the plants during the daytime and generating extra heat in the room. Since the accumulated near infrared rays are reflected, it is possible to reduce the cooling load without using any other light shielding means or any power. Also, it has a great heat retaining effect in winter.

Moreover, according to the above wall structure, maintenance-free, clean,
An inexpensive and long-life plant growing device can be provided.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

First, FIG. 1 is a diagram showing the shape of a model greenhouse for testing the characteristics of the wall structure of a greenhouse according to an embodiment of the present invention, where (a) is a cross-sectional view and (b) is ( FIG. 2A is a side cross-sectional view, and FIG. 2 is an explanatory view showing seven types of wall body configurations in the model greenhouse of FIG.

As shown in Fig. 1, the model greenhouse for testing the characteristics of the panel structure related to the wall body is equivalent to the plant growing space area by the test wall panel 1, the heat insulating wall 2a made of heat insulating material, and the heat insulating floor 2b. Is a greenhouse, and the floor has a heat absorbing plate 3,
It has a small fan 4. 5 is a temperature sensor for testing the characteristics of this model greenhouse.

The side cross-sectional view of FIG. 1 (b) corresponds to the north-south cross-section of the greenhouse, 1a is the south side wall of the south wall of the sample wall panel 1, and 1b is the roof of the sample wall panel 1. The face wall body, 1c shows the north face side wall of the north face wall body of the sample wall body panel 1.

FIG. 2 shows the wall structure of seven types of model greenhouses, and the wall structure is shown by symbols for each type No. of model greenhouse.

Each drawing of FIG. 2 shows the same side surface as the side view in the north-south cross section shown in FIG. 1 (b), and the right side of the drawing shows the north side wall and the left side shows the south side wall.

The names of the materials of the wall and the symbols related to the type of wall are as follows.

The following commercially available films are used as materials.

S: Perfectly transparent film, for example polyester film.

R _NIR : Visible light transmission / near infrared reflection type heat ray reflection film,
For example, a polyester film with silver, copper, nickel, etc. allotted. It has a good visible light transmittance and a high reflectance for the near infrared wavelength.

R _IR : A heat ray reflection film of sunlight transmission / infrared reflection type, for example, a film in which titanium oxide, silver, etc. are distributed based on a polyester film. It has good transmittance over all sunlight and high reflectivity for infrared wavelengths.

A: Perfect reflection type film, opaque, and has high reflection characteristics for all wavelengths. For example, a double-sided reflection aluminum film.

As the type of wall body, a wall body panel having the following structure is used.

S ² : A double-layered single-layer wall panel of the completely transmissive film S,
The distance between layers is about 30 mm.

S ³ : A triple-layer wall panel of the completely transmissive film S.

S ² · A: A triple-layer wall panel in which a completely reflective aluminum film A is provided between the completely transmissive films S and S.

S ² · R _NIR : A triple-layer double-layered wall panel in which a visible light transmitting / near infrared reflective heat ray reflective film is provided between the completely transmissive films S and S.

S ² · R _IR : A triple-layered double-walled panel in which a positive light transmission / infrared reflection type heat ray reflection film is provided between the perfect transmission type films S and S.

The model greenhouse of type No. 1 shown in FIG. 2 uses a wall panel (S) whose walls are completely transparent. Type No.
, Uses a wall panel in which completely transmissive films S are sequentially multiplexed. Type No. uses a visible light transmission / near infrared reflection type wall panel (S ² · R _NIR ) on each wall surface. Type No. uses a wall panel (S ² A) of which only the north side wall is a perfect reflection type. Type No. is a wall panel (S ³ ) with a completely transparent side wall on the south side, a fully reflective type panel (S ² · A) on the north side wall, and a visible light transmitting / near infrared reflective type wall with a roof side wall. Body panel (S ² R _NIR ) is used. Type No. uses a positive-transmissive / infrared-reflecting wall panel (S ² R _IR ) only on the south side wall for the configuration of.

Such seven types of model greenhouses shown in Fig. 2 are installed in the field and operated, and the solar radiation I (kcal / m ² · h) and the internal / external temperature difference ΔT _i θ (° C) are the data showing the characteristics. , Measure the effective transmittance of solar radiation τ _e . Note that the effective transmittance τ _e is the amount τ that directly reaches the floor surface at the incident angle i = 0 of the sunlight from the roof surface.
_It consists of ₀ and the amount τρ that reaches the floor after being reflected on the north side wall. Once these data are known, the heat collection characteristics of the model greenhouse can be uniquely determined.

FIG. 3 is a heat collection diagram showing heat collection characteristics of each model greenhouse shown in FIG.

In Fig. 3, the origin is O, and the x-axis (horizontal axis) is the difference in temperature between the inside and outside of the amount of solar radiation X = ΔT _i θ / I (° C / kcal · m- ² · h- ¹ ) and y The heat collection efficiency η is taken on the axis (vertical axis), the optical heat collection efficiency τ _e · α at X = 0 is taken on the y axis, and the measured values are entered.
The heat collection curves of model greenhouse type Nos. ~ Are obtained.

Here, τ _e is the effective transmittance, and α is the absorptance of the floor surface.

The y-axis shows summer and winter separately on the left and right. In winter, the incident angle of sunlight is i = 30 °, the greenhouse is in a closed state, and the intersection of each heat collection curve and the y-axis (black circles) ) Is the optical heat collection efficiency τ
_{It is e} · α.

In the summer, assuming that the sun shines directly on the roof,
The incident angle i = 0 ° of the sunlight, the greenhouse is in an open state such as opening a window, and the intersection (black circle) of each heat collection curve and the y axis is the optical heat collection efficiency τ ₀ · α.

The heat collection curve shown in Fig. 3 is η = τ _e · α-K _t · X (1) X = ΔT _i θ / I (2) where K _t is the effective heat transmission coefficient (kcal / m ² · h · ° C).

If X is the limit value X _c when η = 0, this corresponds to the intersection (black circle) of the x-axis and each heat collection curve.

That is, the equation (3) holds.

X _c = τ _t · α / K _t = ΔT _i θ (max) / I (3) In winter, the effective transmittance τ _e of solar radiation is large and the limit value of the temperature difference between the inside and outside of the solar radiation A large X _c is required.

As is clear from Fig. 3, the model greenhouse type No.
Has the largest ΔT _i θ / I. That is, under the same conditions,
This is a wall panel configuration that can maximize the inside-outside temperature difference ΔT _i θ.

Type No. does not have a large optical heat collection efficiency τ _e · α, but the effective heat transmission coefficient K _t is the smallest among the seven model greenhouses as shown in Fig. 4 (a) described later. , As a result, X _e is the largest.

By the way, a phenomenon of reflective opacity occurs in a film or glass wall having a heat reflection property. In the daytime, only visible rays of sunlight are transmitted through these walls, but near-infrared rays are reflected here and leave the outdoors. That is, the near infrared rays disappear to the outside of the room without any energy conversion and without any time. Therefore, heat does not accumulate in the room. Therefore, no cooling means is required, and fatigue of the plant does not occur. It also saves water. This is called a heat shield effect.

Regarding the heat shield effect in the summer, the characteristics of the roof wall should be examined. The transmission efficiency r is used as an index of the heat shield effect. That is, r = visible light transmittance / total light transmittance (4) r> 1 means that the proportion of heat rays (near infrared rays) is small and the proportion of visible rays is large. It means that it is a cool wall for plants.

Since r> 1 can only occur when the heat ray reflective film R (R _NIR , R _IR ) is used, type No. ,,
, Corresponds to this.

These types of wall panels do not significantly reduce visible light and have an energy cutoff rate (reciprocal of heat collection efficiency) of 50%.
It has some characteristics.

On the other hand, the transmission efficiency r of the type No., is r1 as shown in FIG. 4 (c) described below, and the energy cut-off rates are 10, 20 and 30%, respectively. However, it cannot be used in midsummer unless a light-shielding means, such as a gauze, is added.

Fig. 4 is a diagram that comprehensively evaluates the test data of each model greenhouse, and Fig. 4 (a) shows the effective heat transmission coefficient K _T (kcal / m ² · h · ℃) that shows the adiabatic effect in winter. Figure, (b) is a diagram of the effective transmittance τ _e of solar radiation showing the heat collection effect in the winter and the limit value X _c of the temperature difference between the inside and outside temperature per amount of solar radiation, and (c) is the summer interception. The diagram of the transmission efficiency r showing the heat effect, particularly the heat shield effect of the roof part, and the diagram (d) are diagrams comparing the material costs of the wall panels.

The horizontal axis is common to Figures (a) to (d), and is the type of wall structure, that is, the seven types of model greenhouse type Nos., Arranged from left to right in order from the type No. Shows.

As shown in FIG. 4 (a), the effective heat transmission coefficient K _t decreased from the type No. to the film multiplex, but suddenly showed a large decrease. This is due to the high thermal insulation properties of the wall panels (S ² · R _NIR , S ² · R _IR ). In addition, type No.,
The decrease in ， is due to the addition of the high heat insulating property of the wall panel S ² · A.

As for the effective transmittance τ _e shown in FIG.
From o. to, it decreases with the multiplexing of the film, but the types No. and No. tend to increase on the contrary. This increase is due to the reflection of the wall panel S ² · A on the north side wall. The limit value X _c of the inner and outer temperature difference per insolation, has become larger in the order from the type No., which is largely due to the effect of reducing the effective heat transmission coefficient K _t.

Regarding the transmission efficiency r shown in FIG. 4 (c), as described above, the type No. or those with r> 1 are
Depending on the plant, it will become a cool wall panel.

Regarding the material cost shown in FIG. 4 (d), the most expensive one among the wall materials is the heat ray reflective film,
Type No. using heat ray reflection film R _NIR of visible light transmission / near infrared reflection type on each of the south face, north face side wall and roof face wall.
It is a comparison with other types of costs with the standard (1.0).

Type J.,
It can be understood that has the best performance / cost. The difference from the type No. is due to the importance of heat collection during the day and the importance of heat insulation during the day and night. Therefore, type N
o. is most suitable as a wall structure especially for cold regions,
Type No. is most suitable for areas with relatively high solar radiation even in cold regions.

According to the present embodiment, as shown in the model greenhouse type No., the means for constructing the wall of the greenhouse is composed of three or more kinds of wall panels having greatly different characteristics in terms of light and heat.
In particular, on the south side wall, a completely transmissive wall panel (S ² ) or a sunlight transmissive / near infrared reflective wall panel (S ² · R ^IR )
, A visible light transmitting / near infrared reflecting type wall panel (S ² · R _NIR ) is used for the roof side wall, and the north side wall is
Since the structure uses the completely reflective type wall panel (S ² · A), it is possible to realize a greenhouse that maximizes the heat collection characteristics and heat insulation characteristics in the winter season and maximizes the heat shield characteristics in the summer season.

In particular, by arranging a visible light transmitting / near infrared reflecting wall on the roof surface, extra heat stress is not generated in the plant during the day, and the growth is maintained well. Further, during the daytime, since excess heat is not accumulated in the room, the cooling load can be reduced.

Therefore, the annual operating rate of the greenhouse is good, and it is excellent in all aspects such as maintenance-free, clean, and long life, and it has the effect of significantly improving the management efficiency of the greenhouse.

Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 5 is an explanatory view showing a greenhouse according to another embodiment of the present invention in which the wall has a curved cross section.

As shown in FIG. 5, since the greenhouse wall 1A has a smooth curved surface, the south surface, the north surface, and the roof surface cannot be clearly distinguished.

In this case, it is advisable to consider the winter solstice and summer solstice as the reference. That is, if the intersections between the north end N point of the greenhouse floor and the sun in the middle of the south and the greenhouse wall 1A are γ winter solstice) and δ (summer solstice), the parts below γ are the south side wall, It is rational to regard the wall between γ and δ as the roof wall and the portion below δ as the north side wall. Also, these 3
The ratio of people's division is as follows:
Approximately (1/4 to 1/3): (2/4 to 1/3): (1/4 to 1/3).

In some cases, it may be difficult to distinguish between the south and north faces, so
It may be "south or southeast" as well as "north or northwest". Considering that photosynthetic activity is most active in the morning, the wall panel configuration that maximizes the light transmittance of the southeast side wall is extremely effective.

In the description of each of the above-mentioned embodiments, an example of a greenhouse was taken and described, but the present invention is within a range in which the same effect is expected,
It goes without saying that the wall panel is generally applied to a plant growing device that constitutes a plant growing space region.

〔The invention's effect〕

As described in detail above, according to the present invention, a plant that maximizes the heat collection efficiency in the winter season and therefore has excellent heat insulation, maximizes the heat shield efficiency in the summer season, and has a cheap and simple wall body configuration. A training device can be provided.

Further, according to the present invention, during the day, without excessive heat stress on the plant body, while maintaining good growth, during the day, there is no accumulation of extra heat in the room, cooling load It is possible to provide a plant growing device that can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing the shape of a model greenhouse for testing the characteristics of a greenhouse wall structure according to an embodiment of the present invention.
(A) is a cross-sectional view, (b) is a side cross-sectional view of (a), second
FIG. 4 is an explanatory view showing seven types of wall body configurations in the model greenhouse of FIG. 1, FIG. 3 is a heat collection diagram showing heat collection characteristics of each model greenhouse shown in FIG. 2, and FIG. Is a diagram that comprehensively evaluates the test data of each model greenhouse, and Fig. 5 is
It is explanatory drawing which shows the greenhouse which the cross section of the wall body which consists of curved lines based on the other Example of this invention. 1 ... Test wall panel, 1a ... South side wall, 1b ... Roof side wall, 1c ... North side wall.

Claims (1)

[Claims] 1. A plant growing device in which a plurality of types of wall bodies are combined to form a plant growing space, wherein the plurality of types of wall bodies are a south face wall, a roof face wall and a north face in a north-south cross section of the plant growing device. The south wall is a completely transmissive wall or a positive light transmitting / infrared reflective wall, and the roof wall is a visible light transmitting / near infrared reflective wall. Body, the north face wall body is a perfect reflection type wall body,
A plant growing device characterized by being used respectively.