JP4858239B2 - Air conditioning method for multi-stage plant cultivation equipment - Google Patents

Description

  The present invention relates to an air conditioning method in a multi-stage plant cultivation apparatus that can efficiently grow plants in a stable closed space that is not affected by an external environment equipped with an artificial lighting device or an air conditioning apparatus.

As a multi-stage plant cultivation apparatus in which a multi-stage plant cultivation shelf is installed in a closed space and equipped with an artificial lighting device and an air conditioner, there is a seedling raising apparatus as proposed in Patent Document 1. 1 and 2, this seedling raising apparatus has a light-shielding closed structure 1 surrounded by a heat-insulating wall surface, and a front surface is opened inside the closed structure 1. Box-shaped growing modules 2, 3, 4, 5 are arranged. Inside the breeding module, a plurality of seedling racks 6 are arranged in multiple stages in the vertical direction to form a seedling space between the upper and lower seedling racks, and each seedling rack 6 has a plurality of cell trays 7 into which a plant growth medium is placed. And an irrigation device (not shown) for irrigating each cell tray 7. An artificial lighting device 8 is provided on the rear surface of each seedling shelf 6 so that the cell tray below it is irradiated with light. Furthermore, inside the closed structure 1, air conditioners 9, 10, 11, and 12 for adjusting the temperature of the air in the closed structure are installed, and on the rear wall of each seedling shelf 6 of the growing module, A fan 13 is attached.
By setting it as such a structure, the air temperature-controlled and humidity-controlled by the air conditioners 9-12 is attracted | sucked by the fan 13 from the growth module 2-5 open front surface, and is discharged | emitted to the rear wall of the growth module 2-5 back. A circulating flow as shown by the arrows in FIG. 2 blown to the air conditioners 9 to 12 is formed in the closed structure 1, and the internal space of the closed structure 1 is brought to a temperature and humidity environment optimal for plant growth. Can keep. In addition, although patent document 1 calls such an apparatus as a seedling raising apparatus, it can be used not only for raising seedlings but also for cultivation of the whole plant body.

In the multistage plant cultivation apparatus in the closed space as described above, the artificial lighting device is turned on and off, so that the light period (the time during which the plant performs photosynthesis) and the dark period (the time during which the plant performs photosynthesis) and the dark period ( The plant is breathing). In the light period, since it is necessary to remove heat generated from the lighting device, the cooling operation of the air conditioner is performed.
Further, due to the dehumidifying effect during the cooling operation, it is possible to effectively prevent an increase in humidity in the enclosed space. However, due to long-term cooling operation, condensed water adheres to the fins inside the air conditioner, which tends to cause mold and decrease cooling capacity. In order to remove condensation during cooling operation, the cooling operation is temporarily stopped and only the air blowing operation is performed, or sometimes the heating operation is switched to dry the condensation in the fin portion inside the air conditioner. .

  On the other hand, in the dark period, there is no heat generated from the lighting device, and the heat generated in the enclosed space is negligible, such as fans, so the cooling load is smaller than in the light period and the cooling operation of the air conditioner stops. Or, the cooling operation and the stop are repeatedly performed. As a result, dehumidification, which is a secondary action during the cooling operation of the air conditioner, is not performed effectively, and the humidity in the enclosed space is likely to increase. Sometimes. In addition, the increase in humidity in the enclosed space also causes a problem that it leads to plant heads.

  Even in the light period, there are cases where only a part of the lighting device is used because the light amount of the lighting device is reduced or there is an empty shelf. Furthermore, as a result of a significant decrease in the outside air temperature, the temperature in the enclosed space may also decrease. In these cases, the cooling load in the enclosed space is lower than that in the light period, so the cooling operation of the air conditioner is stopped or the cooling operation and the stop are repeated, and as a result, the same as in the dark period. In addition, the humidity in the enclosed space is likely to rise, and dew condensation inside the air conditioner may cause mold generation or lead to plant heads.

  In order to solve the problem that the cooling operation of the air conditioner stops and the humidity in the enclosed space rises due to the dark period when the lighting device is turned off or due to a decrease in the outside air temperature, etc. In order to increase the cooling load and to increase the frequency of the cooling operation of the air conditioner, auxiliary heating of the closed space is installed. However, in this case, since a heating device is required in addition to the air conditioning device, not only the device configuration becomes complicated, but there is a problem that heating unevenness occurs in the closed space depending on the installation location of the heating device.

JP 2002-291349 A

There is a case where air conditioning in the light period and dark period is performed using one commercial large-scale air conditioner as a method of air conditioning to regulate the humidity of the internal space of a closed structure, but the air conditioner fails. When this happens, there is a fundamental problem that plant growth stops.
Therefore, an air conditioning method as shown in FIG. 1 in which a plurality of relatively small household air conditioners are installed has been proposed. The cooling capacity of the entire air conditioner required when using a plurality of small air conditioners is determined by the cooling load that can remove the heat generated by the entire lighting fixture that is lit during the light period.
However, even when a plurality of air conditioners (four in FIG. 1) are used, the switching between the cooling operation and the heating operation of each air conditioner and the instruction of the target temperature are performed collectively from the control device. Is the actual situation.

  Therefore, the present invention is a multistage plant cultivation apparatus provided with an artificial lighting device and a plurality of air conditioners in a closed structure, and by controlling the operation of each air conditioner independently and finely, The object of the present invention is to provide an air-conditioning method that can suppress an increase in the humidity of the internal space of the closed structure throughout the dark period and suppress the occurrence of mold inside the air-conditioning apparatus.

That is, the present invention arranges a box-shaped growth module whose front is open inside a light-shielding closed structure surrounded by a heat insulating wall surface, and a plurality of plant cultivation shelves are arranged inside the growth module. A plant growing space is formed between upper and lower cultivation shelves by arranging in multiple stages in the vertical direction, and each cell tray is provided with a irrigation device for placing a plurality of cell trays for storing plant growth medium and irrigating each cell tray. Provided on the back of each cultivation shelf is an artificial lighting device that irradiates light to the cell tray below it, and a plurality of air conditioners that regulate the temperature of the air in the closed structure inside the closed structure It is an air conditioning method in a multi-stage plant cultivation apparatus that is installed and has a fan attached to the rear wall of each cultivation shelf of the cultivation module, and when the cooling load inside the closed structure is reduced, the plurality of units Air conditioning Perform heating operation in one of the location, it is characterized in performing the cooling operation in the rest of the air conditioner.
In the present invention described above, it is desirable to sequentially switch one air conditioner that performs the heating operation in a plurality of air conditioners.

According to the present invention, in the light period of plant growth in which all of the artificial lighting devices are turned on, the heat generated from the lighting devices can be effectively removed by performing cooling operation of all of the plurality of air conditioning devices. In addition, an increase in humidity in the closed space can be suppressed. On the other hand, the dark period of plant growth that turns off all of the lighting devices, when only a part of the lighting device is turned on, or when the outside air temperature drops significantly and the temperature in the internal space of the closed structure decreases, When the cooling load in the closed space decreases, only one of the plurality of air conditioners is heated and the remaining air conditioners are cooled, thereby stably preventing the cooling load in the closed space from decreasing. The cooling operation can be continued. As a result, the dehumidifying effect during the cooling operation can effectively suppress an increase in humidity in the closed space, thereby preventing condensation and mold in the closed space, and further preventing the plant from growing.
Further, when the cooling load is reduced, the heating operation is performed with one air conditioner, so that it is not necessary to install a dedicated heating device, and the device configuration can be simplified.

  Furthermore, the dark period is usually about 8 to 12 hours per day. For example, by operating the air conditioner that performs heating operation every several hours in order, the dark period can be changed during the dark period of the day. Heating operation can be performed in turn in any of a plurality of air conditioners. During this heating operation, the condensation generated in the air conditioner can be evaporated and dried, and condensation and mold can be effectively prevented in all the air conditioners.

With reference to FIG. 1 and FIG. 2, preferable embodiment of the multistage plant cultivation apparatus used by this invention is described.
The multistage plant cultivation apparatus used in the present invention has a plurality of box-shaped (four in the illustrated example) growth modules 2 in the inner space of the light-shielding closed structure 1 surrounded by a heat insulating wall surface, 3, 4, and 5 are arranged. A typical closed structure includes a box-shaped hexahedron in which a reinforcing bar, a slate plate, and a heat insulating material are combined. The outer shape of the structure is not particularly limited to a box shape, and may be a bowl shape, a semi-cylindrical shape, a hemispherical shape, or the like.
The size of the internal space of the closed structure 1 may be set to an appropriate size according to the number of growing modules arranged inside the closed structure 1. In the example shown in FIG. 1, two seedling modules 2 and 3 are arranged in a row so that their open front faces in the same direction, and the two seedling modules 4 and 5 also have the same open front. The rows are arranged in the direction so as to form one row, and two rows are arranged in the internal space of the closed structure 1 so that the open front faces each other. In addition, a work space that allows one or more workers to work is provided between these two rows. In order to increase the area utilization factor and the space utilization factor of the internal space of the closed structure 1, it is preferable to make the work space as small and narrow as possible. When arranging the growth modules 2 to 5 inside the closed structure 1, a gap with a width of about 5 to 30 cm is provided between the wall surface of the closed structure and the rear wall of the growth module, and the growth is performed. A passage for the air passing through the module and exhausted to the back of the growing module is formed.

  The closed structure 1 is equipped with a plurality of air conditioners having a function of adjusting the temperature of the air in the internal space and circulating the adjusted air under the set conditions. The indoor units 9, 10, 11, and 12 of the air conditioner are attached to the upper part of the inner surface of the side wall of the closed structure 1 behind the rear of each breeding module, and the outdoor unit (not shown) is installed outside the closed structure 1. .

  As shown in FIGS. 3 and 4, the seedling raising module 2 disposed in the internal space of the closed structure 1 is provided with a side wall 2a and a back wall 2b on the side and the back, and a box shape in which the front is opened. The inside has a plurality of cultivation shelves 6 arranged in multiple stages at regular intervals in the vertical direction, thereby increasing the area utilization efficiency of the cultivation space. The height of each growing module 2 is about 200 cm, which is a height at which an operator can work, and the width of the cultivation shelf 6 is a tens to hundreds of cells (small bowls) arranged in a grid. It is preferable that a plurality of resin cell trays 7 can be placed side by side and the temperature and humidity of each shelf can be adjusted to be constant, for example, about 100 cm to 200 cm, and the depth of the cultivation shelf 6 is 50 cm to 100 cm.

  A plurality of cultivation shelves 6 arranged in multiple stages (four stages in the embodiment of FIG. 3) in the growing module 2 are substantially horizontal, and a plant cultivation space is formed between the cultivation shelves 6. The space utilization rate can be increased by reducing the interval between adjacent cultivation shelves and increasing the number of shelves. However, if the interval between the cultivation shelves is too small, workability such as taking in and out of the cell tray 7 deteriorates, Since there is a drawback that the maximum length cannot be secured, it is preferable that the length is at least about 30 cm. The cultivation shelf 6 can be formed of a metal plate, a metal net, a metal bar, or the like.

  Each cultivation shelf 6 is provided with an automatic bottom irrigation device or a manual irrigation device (not shown), and a plurality of cell trays 7 are placed thereon. Further, an artificial lighting device 8 is attached to the rear surface of each cultivation shelf 6 to irradiate light on plants growing on the cell tray of the cultivation shelf immediately below. The uppermost cultivation shelf is irradiated by the artificial lighting device 8 attached to the back surface of the top wall 2c of the seedling module.

  The light source of the artificial lighting device 8 is preferably a fluorescent lamp, and the candle light, length, etc. of the fluorescent lamp can be appropriately selected according to the width and length of one cultivation shelf 6 and the interval between the cultivation shelves 6. For example, if the cultivation shelf has a width of 120 cm and a length of 60 cm and the interval between the cultivation shelves is 35 cm, 4 to 8 fluorescent lamps with a length of 120 cm and 45 W are installed in parallel to the back of each cultivation shelf. Good.

As can be seen from FIG. 3, a plurality of fans 13 are attached to each stage back wall 2 b of the cultivation shelf 6. By operating the fan 13, it is possible to generate a circulating air flow as indicated by an arrow in FIG. 2 in the internal space of the closed structure 1. That is, the air whose temperature is controlled by the indoor units 9 to 12 of the air conditioner is sucked by the fan 13 into the cultivation space of each stage of the cultivation shelf 6 from the open front side of the cultivation modules 2 to 5, and the rear wall of the cultivation module 2b is discharged backward. The air discharged to the rear of the rear surface of the growing module is sucked into the indoor units 9 to 12 of the air conditioner, temperature-controlled, and then blown again to the front side of the growing module 2 to 5. When the two rows of growing modules 2, 3, 4, and 5 are arranged so that a working space is formed between them as in the embodiment shown in FIGS. 1 and 2, this working space is air. Since it also functions as a circulation path, an effective circulation flow can be brought about.
When the circulating flow passes through the respective cultivation shelves 6 of the growing modules 2 to 5, water vapor evaporated from the irrigation device, the soil, the plant body, and the heat released from the artificial lighting device 8 are accompanied by the circulating flow. By controlling the temperature of the flow by the indoor units 9 to 12 of the air conditioner and continuously circulating the flow, the internal space of the closed structure 1 can be maintained in a temperature and humidity environment optimal for plant growth.

  As shown in FIG. 1, the closed structure is provided with an entrance 14 so that an operator and various devices can be taken in and out. Moreover, since the internal space of the closed structure 1 is highly sealed, it is necessary to artificially supply the carbon dioxide that the growing plant consumes in photosynthesis under normal ventilation conditions. A liquefied carbon dioxide cylinder 15 is installed outside the structure, and a carbon dioxide concentration sensor (not shown) is provided inside the closed structure.

An embodiment of the air conditioning method of the present invention in the multi-stage plant cultivation apparatus having the above-described structure will be described in detail below.
However, the multi-stage plant cultivation apparatus used in this example is grown in a closed structure in which a bottom floor having a long side of 450 cm and a short side of 360 cm is surrounded by a heat-insulating and light-shielding wall having a height of 240 cm. A device in which six modules were arranged was used. Each of the growing modules has a height of 180 cm, a width of 128 cm, and a depth of 70 cm, and four cultivation shelves are provided in the vertical direction. Three growth modules were connected to each other and arranged in two rows so that the open front faces each other. The gap between the rear wall of the growth module and the side wall of the closed structure was about 20 cm.

  On each cultivation shelf, the plant body was stored and placed in a cell tray together with the culture medium, and automatic bottom irrigation was performed. On the back of each cultivation shelf, six fluorescent lamps (HF32 type, power consumption 45 W) were installed as artificial lighting devices, and the cultivation shelf underneath was irradiated. Moreover, four fans (DC24V, power consumption 6W) were installed in the back wall of each cultivation shelf, the air in the cultivation space of each shelf step was attracted | sucked, and it was made to discharge | emit to the rear surface of a cultivation module. The airflow discharged to the back of each cultivation shelf rises through a narrow gap between the rear wall of the growing module and the side wall of the closed structure, and is sucked into the air conditioner to adjust the temperature and humidity.

  A total of four air conditioners (air conditioners having a cooling capacity of 2.8 kW) were attached to the side walls of the closed structure above the growth modules in each row. The capacity and the number of installed air conditioners are determined by the cooling load in the enclosed space, and the cooling load is mainly caused by the lighting device and the fan. In the present embodiment, the cooling load of the lighting device is 45 W × 6 (lines) × 4 (stage) × 6 (number of breeding modules) = about 6.5 kW, and the cooling load of the fan is 6 W × 4 (pieces). ) × 4 (stage) × 6 (number of growing modules) = about 0.6 kW, which is about 7.1 kW in total. On the other hand, for example, stable cooling operation of the air conditioner at a room temperature of 20 ° C. is performed at about 70% of the rating, and the maximum cooling capacity of the four air conditioners is 2.8 kW. × 4 (units) × 70% = 7.84 kW, which is almost equal to the maximum cooling load caused by the lighting device and the fan.

In the light period when photosynthesis of plants is performed, since all of the lighting device and the fan are operated, the cooling operation of the air conditioner is simultaneously performed. Although the temperature setting of an air conditioner changes with plants to grow, it is normally between 20-28 degreeC. At that time, the relative humidity in the enclosed space is maintained at 85% or less due to the dehumidifying effect by the cooling operation of the air conditioner against the water evaporation from the plants and the culture medium.
During the light period, since the cooling operation of all the air conditioners is performed, condensed water adheres to the heat exchange fins inside the air conditioner. Most of the condensed water is discharged to the outside through the piping, but the fin portion is always in a condensed state during the cooling operation. For this reason, the interior of the air conditioner becomes wet due to long-term cooling operation, and it tends to cause a decrease in cooling capacity due to the occurrence of mold. Therefore, the cooling operation of all the air conditioners is temporarily stopped from time to time, and the operation of only blowing or switching to the heating operation is performed to evaporate and dry the dew condensation on the fin portion and the surrounding area.

  In the dark period when the plant breathes, the lighting device is turned off, so that the cooling load in the closed space is reduced to about 0.6 kW of the fan alone. The amount of water evaporation from the plants and culture medium that occurs during the dark period seems to be about 1/2 to 1/5 that of the light period. If all four air conditioners are in cooling operation in this state, Since the cooling load is low, the cooling operation is not sufficiently performed. As a result, the dehumidification is not sufficiently performed, and the relative humidity in the closed space may be 90 to 100%. At such high humidity, the growth of the plant is suppressed, and it is easy to cause a decrease in the lifetime of the indoor equipment and failure.

  Therefore, in the present invention, one of the four air conditioners is operated for heating. As a result, the cooling load in the enclosed space can be increased by about 0.5 to 1 kW. As a result, it is possible to enhance the cooling operation of the remaining three air conditioners and to perform sufficient dehumidification. Even in the period, the relative humidity in the enclosed space can be suppressed to about 85%.

When only one air conditioner is operated for heating, the dew condensation inside the air conditioner can be evaporated and dried for one of them, and mold generation and the like can be effectively prevented. However, the remaining three air conditioners are kept in a state where condensation is caused by continuing the cooling operation, which causes mold and the like. In order to prevent such a situation from occurring, it is desirable to sequentially switch one air conditioner that performs the heating operation to four air conditioners. As a result, it is possible to give time for heating operation to all four air conditioners, and the condensation generated inside during cooling operation can be evaporated and dried during the time of heating operation. It is possible to eliminate the state in which dew condensation has occurred inside the apparatus, and to effectively prevent mold generation and the like.
Specifically, for example, if the heating operation is performed with the first air conditioner for one hour during the dark period and the heating operation is performed with the second air conditioner for the next one hour, the heating operation is performed for four hours. In addition, all four air conditioners can always perform the heating operation for one hour, so that the condensation inside all the air conditioners can be evaporated and dried.

  Note that not only in the dark period but also in the light period, there is a case where only a part of the illumination apparatus is lit because the light amount of the illumination apparatus is reduced or there is an empty shelf. In this case, since the cooling load in the closed space is reduced even in the light period, there is a possibility that dehumidification by the cooling operation of the air conditioner may not be performed appropriately. In addition, although the closed type structure is blocked by the heat insulating wall, the temperature inside the closed type structure may decrease when the outside air temperature decreases significantly. In this case, the cooling load in the closed space also decreases. Therefore, the room temperature falls below the target set temperature of the air conditioner, and there is a possibility that the cooling operation of the air conditioner will not be sufficiently performed. In this way, when the cooling load in the enclosed space is reduced in addition to the dark period, the cooling load can be prevented from being lowered by heating only one of the air conditioners as an auxiliary heat source. Thus, it is possible to appropriately perform the cooling operation in the remaining air conditioners.

  Each air conditioner is controlled by a control signal from the control device. The control signal has an operation mode and a set temperature, and the control signal is sent to each air conditioner for each light period and dark period based on a control program created in advance. When it is necessary to perform heating operation for only one air conditioner, an air conditioner targeted by the control program is selected, and only one of them is set for heating operation. The control signal can be transmitted to the air conditioner through a cable, by an infrared remote controller, or by pseudo-creating an infrared remote controller signal from an LED.

  A temperature sensor for monitoring the temperature in the closed structure is connected to the control device of the air conditioner. Multiple temperature sensors may be installed at multiple locations in a closed structure, and the average value of each temperature sensor may be calculated. However, if one temperature sensor is installed at one location, it will be closed. It is necessary to provide an installation place where the air flow in the mold structure is mixed and uniformed so that the average temperature in the closed structure can be measured.

It is a schematic plan view which shows preferable embodiment of the multistage type plant cultivation apparatus used by this invention. It is a schematic longitudinal cross-sectional view which shows the flow of the air in the internal space of the multistage plant cultivation apparatus shown in FIG. It is a front view which shows the Example of the growth module used for the multistage plant cultivation apparatus shown in FIG. FIG. 4 is a side view of the growing module shown in FIG. 3.

Explanation of symbols

1: Closed structure 2-5: Growing module 6: Cultivation shelf 7: Cell tray 8: Artificial lighting device 9-12: Air conditioner 13: Fan

Claims (2)

  A box-shaped growth module with an open front surface is placed inside a light-shielding closed structure surrounded by a heat insulating wall, and a plurality of plant cultivation shelves are vertically arranged in the inside of the growth module. A plant growth space is formed between the upper and lower cultivation shelves by arranging, and each cultivation shelf is provided with a irrigation device for placing a plurality of cell trays for storing plant growth medium and irrigating each cell tray. The rear surface is provided with an artificial lighting device that irradiates light to the cell tray below it, and a plurality of air conditioners that regulate the temperature of the air in the closed structure are installed inside the closed structure, and the cultivation is performed An air conditioning method in a multi-stage plant cultivation device in which a fan is attached to the back wall of each cultivation shelf of the module, and when the cooling load inside the closed structure is reduced, of the plurality of air conditioning devices Warm with one It performs the operation, the air conditioning method in multistage plant cultivation apparatus which is characterized in that the cooling operation in the rest of the air conditioner.   The air conditioning method according to claim 1, wherein one air conditioner that performs the heating operation is sequentially switched in a plurality of air conditioners.

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