Air conditioning system, plant factory, and air conditioning method

Abstract

Efficiently maintaining an environment suitable for growth of a target plant in a growth chamber SOLUTION: An air-conditioning system applied to a plant factory includes a plurality of devices and a path formation unit that forms an air path through which air sucked from a plant placement area in a growth chamber of the plant factory is air-conditioned by the plurality of devices and supplied to the plant placement area. The plurality of devices include a dehumidifier that dehumidifies air passing through the path, a heat recovery machine that recovers heat of the air passing through the path, and an air conditioner that adjusts a temperature of the air passing through the path. The path is provided so that air sucked from the arrangement area passes through the dehumidifier, the heat recovery machine, and the air conditioner in this order.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air conditioning system, a plant factory, and an air conditioning method. [Background technology]

[0002] A known plant factory is attached to a factory and includes a growth chamber in which plants are grown, and a cold energy supply device that supplies cold energy of 90°C or less from the factory to the growth chamber (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 043381 Summary of the Invention [Problem to be solved by the invention]

[0004] In a plant factory, it is desirable to efficiently maintain an environment inside the growth chamber that is suitable for plant growth in order to reduce production costs.

[0005] The present invention provides a technology for efficiently maintaining an environment in a growth chamber suitable for the growth of a target plant. [Means for solving the problem]

[0006] The present invention includes the following aspects. [Aspect 1] An air conditioning system applied to a plant factory, Multiple devices and a path forming unit that forms an air path for air-conditioning the air sucked from a plant arrangement area in the growth room of the plant factory by the plurality of devices and supplying the air to the plant arrangement area; Equipped with The plurality of devices include: a dehumidifier that dehumidifies the air passing through the path; a heat recovery machine that recovers heat from the air passing through the path; an air conditioner that adjusts the temperature of air passing through the path; Including, The path is provided so that air drawn from the placement area passes through the dehumidifier, the heat recovery machine, and the air conditioner in this order. Air conditioning system. [Aspect 2] 2. The air conditioning system of claim 1, Further provided is a carbon dioxide gas supply unit that supplies carbon dioxide gas to the air supplied to the placement area in the path. Air conditioning system. [Aspect 3] 3. The air conditioning system according to claim 2, Operates in conjunction with the operation of a light source that supplies light to plants in the growth chamber; Air conditioning system. [Aspect 4] The air conditioning system according to any one of aspects 2 and 3, a first measurement unit that measures a first concentration, which is a carbon dioxide concentration of air before carbon dioxide is supplied by the carbon dioxide supply unit; a second measurement unit that measures a second concentration, which is a carbon dioxide concentration after the carbon dioxide gas is supplied by the carbon dioxide gas supply unit; Furthermore, The supply amount of the carbon dioxide gas from the carbon dioxide gas supply unit is set based on the first concentration and the second concentration. Air conditioning system. [Aspect 5] The air conditioning system according to any one of aspects 2 to 4, The plurality of devices further include a carbon dioxide vaporizer that vaporizes liquefied carbon dioxide gas by utilizing heat recovered from air passing through the path, The carbon dioxide gas supply unit supplies liquefied carbon dioxide gas vaporized by the carbon dioxide gas vaporizer. Air conditioning system. [Aspect 6] 6. The air conditioning system of claim 5, The path is configured so that air drawn from the placement area passes through the dehumidifier, the heat recovery machine, the carbon dioxide vaporizer, and the air conditioner in this order. Air conditioning system. [Aspect 7] The air conditioning system according to any one of aspects 1 to 6, The path forming portion is a shroud covering the air inlets and outlets of the plurality of devices; a duct connecting the plurality of devices; Including, Air conditioning system. [Aspect 8] A plant factory equipped with the air conditioning system according to any one of aspects 1 to 7. [Aspect 9] 9. The plant factory according to claim 8, a collection unit provided in each of the plurality of devices and configured to collect condensed water for use in growing plants; plant factory. [Aspect 10] An air conditioning method for a plant factory, comprising: Suctioning from a plant placement area in a growth chamber of the plant factory; The air sucked by the suction is air-conditioned by a plurality of devices; supplying conditioned air to the placement area by the air conditioning; Including, The plurality of devices include: a dehumidifier that dehumidifies the air passing through the path; a heat recovery machine that recovers heat from the air passing through the path; an air conditioner that adjusts the temperature of air passing through the path; Including, In the air conditioning, the sucked air passes through the dehumidifier, the heat recovery machine, and the air conditioner in this order. Air conditioning method. [Effects of the Invention]

[0007] The present invention provides a technology for efficiently maintaining an environment inside a growth chamber that is suitable for the growth of a target plant. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an overview of a plant factory according to an embodiment. [Figure 2] A diagram showing an example of the layout area [Figure 3] Diagram showing an example of a plant factory layout DETAILED DESCRIPTION OF THE INVENTION

[0009] [Plant factory] FIG. 1 is a schematic diagram of a plant factory 1 according to one embodiment. FIG. 2 is a diagram illustrating an example of the configuration of the placement area A. The plant factory 1 includes a growth chamber R and a machine room M. The plant factory 1 also includes an air conditioning system 10, which will be described later, and the air in the growth chamber R is conditioned by the air conditioning system 10 to be suitable for plants. The growth chamber R is provided with a plant placement area A. The placement area A is provided with, for example, a growth shelf 40 on which plants are placed. While FIG. 2 illustrates a configuration with a single top plate on which plants can be placed, the growth shelf 40 may be configured with multiple top plates so that plants can be arranged vertically. A plurality of devices 11 included in the air conditioning system 10 are placed in the machine room M. As will be described in more detail later, the air conditioning system 10 includes a path forming unit 15 that forms an air movement path (path 15a) spanning between the growth chamber R and the machine room M. The air from the growth chamber R introduced into this movement path is air-conditioned by the plurality of devices 11 and then supplied back to the growth chamber R.

[0010] The plant factory 1 also includes a recovery unit 20 that is provided in each of the multiple devices 11 and recovers condensed water for use in growing plants. For example, in the plant factory 1 of this embodiment, plants are grown using a hydroponic cultivation method. The water recovered by the recovery unit 20 is pumped to a location (such as a tank) where the solution is adjusted. The water after the solution adjustment (adjusted solution) is supplied to the plants by a supply unit (not shown) for use in growing the plants.

[0011] [Air conditioning system] <Summary> The air conditioning system 10 is applied to a plant factory 1. The air conditioning system 10 of this embodiment includes a plurality of devices 11 and a path forming unit 15. The plurality of devices 11 are arranged along a path 15a formed by the path forming unit 15.

[0012] <Multiple devices and path forming units> The plurality of devices 11 include a dehumidifier 111 , a heat recovery machine 112 , and an air conditioner 113 .

[0013] The dehumidifier 111 dehumidifies the air passing through the path 15a. The dehumidifier 111 does not necessarily have to be capable of humidifying as well as dehumidifying, but may instead be a dehumidifier that only dehumidifies. In the plant factory 1, the humidity of the air in the arrangement area A tends to increase due to transpiration by the plants. If the humidity in the arrangement area A is high, transpiration may be suppressed, which may affect the growth of the plants, so the dehumidifier 111 dehumidifies the air sucked from the arrangement area A. Generally, to maintain a constant temperature and humidity indoors, not only dehumidification but also humidification is required, but in this embodiment, the system can be simplified by employing equipment that only dehumidifies.

[0014] The heat recovery machine 112 recovers heat from the air passing through the path 15a. For example, the heat recovery machine 112 may be a heat pump water heater, which may supply hot water by utilizing the heat of the air passing through the path 15a. In other words, the heat recovery machine 112 may be a device that can utilize the heat recovered from the air passing through the path 15a. Furthermore, for example, the heat recovery machine 112 may be a device that has the function of recovering heat from the air passing through the path 15a but does not have the function of imparting heat to the air passing through the path 15a.

[0015] The air conditioner 113 adjusts the temperature of the air passing through the path 15a. Here, the air conditioner 113 may be an indoor unit of a heater / cooler.

[0016] The path forming unit 15 forms a path 15a through which air drawn from an area A where plants are arranged in the growth chamber R of the plant factory 1 is air-conditioned by a plurality of devices 11 and supplied to the area A.

[0017] In this embodiment, the path 15a is provided so that the air drawn in from the placement area A passes through the dehumidifier 111, the heat recovery unit 112, and the air conditioner 113 in that order. In the plant factory 1, the temperature inside the growth chamber R may be adjusted to lower the temperature due to heat generated by light sources and the like provided for photosynthesis by plants. In this embodiment, the path 15a is provided so that the arrangement order of the multiple devices 11 is such that the air drawn in from the placement area A passes through the dehumidifier 111, the heat recovery unit 112, and the air conditioner 113 in that order, thereby enabling efficient air conditioning.

[0018] Specifically, by first dehumidifying the air drawn in from the arrangement area A with the dehumidifier 111, the specific heat of the air is reduced, making it easier to lower the temperature of the air with subsequent equipment. Next, by recovering heat with the heat recovery machine 112, the recovered heat can be utilized while lowering the temperature of the air. Finally, the temperature of the air after the heat recovery machine 112 recovers the heat is adjusted with the air conditioner 113, so that the operation of the air conditioner 113 can be suppressed.

[0019] Furthermore, in this embodiment, the plurality of devices 11 are connected in series along the path 15a of the air collected from the arrangement area A. This allows for more efficient air conditioning than when the plurality of devices 11 independently collect and condition air.

[0020] The plurality of devices 11 may further include a carbon dioxide vaporizer 114 that vaporizes liquefied carbon dioxide by utilizing heat recovered from air passing through path 15a. In this case, path 15a may be configured so that air drawn in from installation area A passes through dehumidifier 111, heat recovery machine 112, carbon dioxide vaporizer 114, and air conditioner 113 in that order. The carbon dioxide vaporizer 114 can also recover heat from the air passing through path 15a when vaporizing the liquefied carbon dioxide. This makes it possible to suppress the operation of the air conditioner 113. The vaporized carbon dioxide is supplied to installation area A by a carbon dioxide supply unit 12, which will be described later.

[0021] The path forming unit 15 includes a shroud 151 that covers the air inlets and outlets of the multiple devices 11 and ducts 152 that connect the multiple devices 11. This allows the multiple devices 11 to be connected in series with respect to the air flow. A duct 152 may also be provided between the placement area A and the multiple devices 11. The duct 152 may be, for example, a pipe made of metal or resin, or a tube made of a flexible material. The path forming unit 15 also includes an intake unit 153 at its upstream end in the air flow direction that draws in air from the placement area A, and a supply unit 154 at its downstream end that supplies air to the placement area A. As shown in FIG. 2 , the intake unit 153 draws in water vapor and air 153a with high oxygen concentration, high temperature, and high humidity from above the plant. The supply unit 154 supplies air 154a with high carbon dioxide concentration and low temperature and humidity from below the plant to the stomata on the underside of the leaves.

[0022] In addition, a blower is appropriately provided in the path 15a to form an air flow in the path 15a. A known blower can be appropriately used as the blower. In this embodiment, an intake-side blower 161 and a supply-side blower 162 are provided. The blowers 161 and 162 may be configured to blow the same amount of air. For example, the fans of the blowers 161 and 162 may be driven by the same rotating shaft, or each may be controlled to blow the same amount of air. In addition, the blowers 161 and 162 may be linked to the operation of the LED light source 19 described below and may operate only when the LED light source 19 is turned on.

[0023] <Carbon dioxide gas supply unit and measurement unit> The air conditioning system 10 also includes a carbon dioxide gas supply unit 12, a measurement unit 13, and a measurement unit 14.

[0024] The carbon dioxide gas supply unit 12 supplies carbon dioxide gas to the air supplied to the arrangement area A through a path 15a. The carbon dioxide gas supply unit 12 includes a path forming member 121, an adjustment valve 122, and a control unit 123. The path forming unit 121 is composed of members such as pipes and tubes that form a path 121a that guides carbon dioxide gas vaporized in the carbon dioxide gas vaporizer 114 to the path 15a. The adjustment valve 122 is a valve for adjusting the amount of carbon dioxide gas introduced from the path 121a to the path 15a. The control unit 123 controls the aperture of the adjustment valve 122. The control unit 123 is, for example, a control circuit including one or more processors such as a CPU (Central Processing Unit) and a memory. The function of the control unit 123 may be realized by the processor operating in accordance with a program (software) readably stored in the memory. The control unit 123 may control the aperture of two or more adjustment valves 122.

[0025] The measurement unit 13 measures a carbon dioxide concentration C1 of the air before carbon dioxide is supplied by the carbon dioxide supply unit 12. The measurement unit 14 measures a carbon dioxide concentration C2 after carbon dioxide is supplied by the carbon dioxide supply unit 12. For example, the measurement unit 13 is provided in the arrangement area A or on the path 15a upstream in the air flow direction from the position where carbon dioxide is supplied by the carbon dioxide supply unit 12. Alternatively, for example, the measurement unit 14 is provided on the path 15a downstream in the air flow direction from the position where carbon dioxide is supplied by the carbon dioxide supply unit 12.

[0026] The amount of carbon dioxide supplied by the carbon dioxide supply unit 12 can be set based on the difference between the carbon dioxide concentrations C1 and C2. For example, if the difference (C2 - C1) between the carbon dioxide concentrations C1 and C2 is relatively large, it is considered that the plants can absorb more carbon dioxide, so the amount of carbon dioxide supplied may be increased. Alternatively, if the difference (C2 - C1) between the carbon dioxide concentrations C1 and C2 is relatively small, it is considered that the plants performing photosynthesis cannot absorb any more carbon dioxide even if the amount of carbon dioxide supplied is increased, so the amount of carbon dioxide supplied may be maintained or decreased. The control unit 123 receives sensor values ​​S1 and S2, which are the values ​​of the carbon dioxide concentrations C1 and C2, from the measurement units 13 and 14, respectively, determines the opening degree of the adjustment valve 122 based on the received values, and transmits a control signal S3 to the adjustment valve 122.

[0027] The values ​​of carbon dioxide concentrations C1 and C2 are determined based on the amount of carbon dioxide absorbed by plants and the temperature of the growing room. The carbon dioxide concentration C2 may be set taking into consideration safety within the area A (or the growth chamber R, such as its impact on the human body). For example, the measurement unit 13 may be arranged to measure the carbon dioxide concentration C1 of the atmosphere within the area A (or the growth chamber R). In this case, the upper limit of the carbon dioxide concentration C1 may be 3000 ppm, 2500 ppm, 2000 ppm, 1500 ppm, or 1000 ppm, taking safety into consideration. The carbon dioxide concentration C2 may also be set according to the amount that can be absorbed by plants. When an artificial light source such as the LED light source 19 is used, plants may absorb more carbon dioxide than when photosynthesizing using natural light. Therefore, the upper limit of the carbon dioxide concentration C2 may be 6000 ppm, 5500 ppm, 5000 ppm, 4500 ppm, 4000 ppm, 3500 ppm, 3000 ppm, 2500 ppm, or 2000 ppm. When the upper limit of the carbon dioxide concentration C1 is set to 3000 ppm and the upper limit of the carbon dioxide concentration C2 is set to 5000 ppm, the amount of carbon dioxide supplied by the carbon dioxide supply unit 12 may be adjusted so that the difference (C2-C1) between the carbon dioxide concentrations C1 and C2 is maintained at 2000 ppm. Alternatively, the amount of carbon dioxide supplied by the carbon dioxide supply unit 12 may be adjusted in accordance with fluctuations in the difference (C2-C1) while maintaining the difference (C2-C1) at 2000 ppm.

[0028] The air supplied with carbon dioxide by the carbon dioxide supply unit 12 is supplied to the placement area A by the supply unit (not shown) of the path forming unit 15. At this time, the supply unit may supply air toward the plants (especially the back of the leaves) placed on the growth shelf 40. Thereby, air with a high carbon dioxide concentration can be guided to the back side of the leaves. Also, for example, the supply unit may be provided at the lower part of the growth shelf 40, and the intake unit may be provided at the upper part of the growth shelf 40. In the present embodiment, since the air containing water vapor evaporated by transpiration is heated by the LED light source 19 and stays at the upper part of the growth shelf 40, by providing the intake unit at the upper part, the air containing water vapor can be effectively recovered and heat can be dissipated. Also, for example, the supply unit may be provided on each shelf board of the growth shelf 40 and configured to blow air upward from the shelf board. According to these, plants that perform photosynthesis can efficiently absorb carbon dioxide. Here, the air supplied by the supply unit is dehumidified by the dehumidifier 111 and has a lower humidity than the air existing in the placement area A (that is, the air taken in by the intake unit). Therefore, transpiration of the plants can be promoted.

[0029] <LED light source> Further, the environment control system 10 includes the LED light source 19. The LED light source 19 supplies light for photosynthesis to the plants in the growth chamber R. In the present embodiment, the air conditioning system 10 operates to supply carbon dioxide in conjunction with the operation of the LED light source 19. For example, the carbon dioxide supply unit 123 receives a lighting signal S4 indicating whether the LED light source 19 is lit from the LED light source 19, and adjusts the opening degree of the adjustment valve 122 of the carbon dioxide supply unit 12 according to the value of the lighting signal S4. In the plant factory 1, in order to reproduce day and night, the LED light source 19 may be lit only during a predetermined time period of the day. Even if carbon dioxide is supplied to the placement area A during the time period when the LED light source 19 is not lit, the plants do not perform photosynthesis. Therefore, by operating the air conditioning system 10 so that the supply of carbon dioxide by the carbon dioxide supply unit 12 is performed in conjunction with the on / off of the LED light source 19, specifically, in accordance with the lighting of the LED light source 19, the supply of carbon dioxide can be efficiently performed.

[0030] Furthermore, the amount of carbon dioxide gas absorbed by plants during photosynthesis increases as the light received by the plants from the LED light source 19 becomes stronger. Therefore, the air conditioning system 10 may be operated so that the carbon dioxide gas supply unit 12 supplies carbon dioxide gas in conjunction with the output of the LED light source 19. Specifically, the amount of carbon dioxide gas supplied by the carbon dioxide gas supply unit 12 may be controlled so that the amount of carbon dioxide gas supplied increases as the output of the LED light source 19 increases. Furthermore, by supplying an appropriate amount of carbon dioxide gas in conjunction with the operation of the LED light source 19, it is possible to prevent the carbon dioxide gas concentration in the growth chamber from increasing more than necessary.

[0031] Furthermore, linking this type of carbon dioxide supply with an LED light source is more effective when supplying air to plants (especially the undersides of leaves). This is because it allows for more appropriate local changes in the carbon dioxide concentration near the plants than adjusting the carbon dioxide concentration throughout the growth chamber R.

[0032] FIG. 3 is a diagram showing an example layout of the plant factory 1. The plant factory 1 includes three growth chambers R1 to R3 and two machine rooms M1 to M2. The multiple devices 11 provided in the machine room M1 are configured to be able to air-condition any of the growth chambers R1 to R2. The multiple devices 11 provided in the machine room M2 are configured to be able to air-condition any of the growth chambers R2 to R3. In the growth chamber R2, a switching mechanism may be provided in the duct 152 of the path formation unit 15 so that it is possible to switch between the multiple devices 11 in the machine room M1 and the multiple devices 11 in the machine room M2 that perform air-conditioning.

[0033] For example, in each of the growth chambers R1 to R3, the LED light sources 19 are turned on for 16 hours a day to simulate day and night, and the LED light sources 19 are turned off for the remaining 8 hours. As shown in Table 1, by staggering the lighting times of the LED light sources 19 in each of the growth chambers R1 to R3, the number of mechanical rooms can be made less than the number of growth rooms. Note that the number of cultivation rooms R and mechanical rooms M is an example and can be changed as appropriate.

[0034] [Table 1]

[0035] Note that even in a growth room where the LED light sources 19 are off and air conditioning is not being performed by the equipment in the mechanical room, ventilation alone may be performed. While the LED light sources 19 are off, plants do not perform photosynthesis but do respire, resulting in transpiration. Therefore, air conditioning, including the supply of carbon dioxide gas, by the equipment in the mechanical room is not necessary, but by configuring the growth room so that ventilation alone is performed, the environment in the growth room can be maintained more appropriately. In another embodiment, the number of growth chambers and the number of mechanical rooms may be the same, and carbon dioxide gas may not be supplied by the carbon dioxide gas supply unit 12 to growth rooms where the LED light sources 19 are not turned on. Furthermore, a single growth room may be divided into multiple areas, and the lighting of the LED light sources 19 and air conditioning by the equipment in the mechanical room may be performed for each area. [Explanation of symbols]

[0036] 1 Plant factory, 10 Environmental adjustment system, 11 Multiple devices, 15 Path formation section, 111 Dehumidifier, 112 Heat recovery machine, 113 Air conditioner

Claims

1. An air conditioning system applied to a plant factory, Multiple devices and a path forming unit that forms an air path for air-conditioning the air sucked from a plant arrangement area in the growth room of the plant factory by the plurality of devices and supplying the air to the plant arrangement area; Equipped with The plurality of devices include: a dehumidifier that dehumidifies the air passing through the path; a heat recovery machine that recovers heat from the air passing through the path; an air conditioner that adjusts the temperature of air passing through the path; Including, The path is provided so that air drawn from the placement area passes through the dehumidifier, the heat recovery machine, and the air conditioner in this order. Air conditioning system.

2. 2. The air conditioning system according to claim 1, Further provided is a carbon dioxide gas supply unit that supplies carbon dioxide gas to the air supplied to the placement area in the path. Air conditioning system.

3. 3. The air conditioning system according to claim 2, Operates in conjunction with the operation of a light source that supplies light to plants in the growth chamber; Air conditioning system.

4. 3. The air conditioning system according to claim 2, a first measurement unit that measures a first concentration, which is a carbon dioxide concentration of air before carbon dioxide is supplied by the carbon dioxide supply unit; a second measurement unit that measures a second concentration, which is a carbon dioxide concentration after the carbon dioxide gas is supplied by the carbon dioxide gas supply unit; Furthermore, a supply amount of the carbon dioxide gas from the carbon dioxide gas supply unit is set based on the first concentration and the second concentration; Air conditioning system.

5. 3. The air conditioning system according to claim 2, The plurality of devices further include a carbon dioxide vaporizer that vaporizes liquefied carbon dioxide gas by utilizing heat recovered from air passing through the path, The carbon dioxide gas supply unit supplies liquefied carbon dioxide gas vaporized by the carbon dioxide gas vaporizer. Air conditioning system.

6. 6. The air conditioning system according to claim 5, The path is configured so that air drawn from the placement area passes through the dehumidifier, the heat recovery machine, the carbon dioxide vaporizer, and the air conditioner in this order. Air conditioning system.

7. 2. The air conditioning system according to claim 1, The path forming portion is a shroud covering the air inlets and outlets of the plurality of devices; a duct connecting the plurality of devices; Including, Air conditioning system.

8. A plant factory equipped with the air conditioning system according to any one of claims 1 to 7.

9. The plant factory according to claim 8, a collection unit provided in each of the plurality of devices and configured to collect condensed water for use in growing plants; plant factory.

10. An air conditioning method for a plant factory, comprising: Suctioning from a plant placement area in a growth chamber of the plant factory; The air sucked by the suction is air-conditioned by a plurality of devices; supplying conditioned air to the placement area by the air conditioning; Including, The plurality of devices include: a dehumidifier that dehumidifies the air passing through the path; a heat recovery machine that recovers heat from the air passing through the path; an air conditioner that adjusts the temperature of air passing through the path; Including, In the air conditioning, the sucked air passes through the dehumidifier, the heat recovery machine, and the air conditioner in this order. Air conditioning method.

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