Control device, cultivation house, and control method

Abstract

Provided is a control method for controlling the temperature in a cultivation house to a target temperature. This control device comprises: an acquisition unit that acquires a cultivation shelf temperature, which is the temperature around a cultivation shelf in a cultivation house; an air conditioning intensity converter that converts the temperature difference between the cultivation shelf temperature and a prescribed target temperature into an air conditioning intensity of an air conditioner that performs air conditioning of the cultivation house; and an air conditioning control unit that calculates the air conditioning intensity for controlling the cultivation shelf temperature to the target temperature on the basis of the cultivation shelf temperature acquired by the acquisition unit and the target temperature, calculates a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity, and commands the calculated set temperature to the air conditioner.

Description

Control Device, Cultivation House, and Control Method

[0001] This disclosure relates to a control device for a cultivation house, a cultivation house, and a control method. This disclosure claims priority based on Japanese Patent Application No. 2025-5168 filed in Japan on January 15, 2025, the content of which is incorporated herein by reference.

[0002] Patent Document 1 discloses a plant cultivation house including an openable and closable skylight, a skylight fan for guiding the air inside the house to the skylight, and curtains provided on the outdoor and indoor sides of the house. A temperature adjustment method is disclosed in which the temperature inside the house is adjusted to a desired temperature by controlling the opening and closing of the skylight, the operation of the skylight fan, and the opening and closing of the curtains based on thresholds provided stepwise between the allowable maximum temperature and the minimum temperature. Patent Document 1 does not disclose a method of controlling the temperature inside the house by controlling an air conditioner.

[0003] Japanese Unexamined Patent Application Publication No. 2024-62928

[0004] In order to adjust the temperature inside the cultivation house to a desired temperature, it is preferable to perform air conditioning control by an air conditioner in addition to opening and closing the curtains, etc.

[0005] This disclosure provides a control device, a cultivation house, and a control method capable of solving the above problems.

[0006] According to one aspect of this disclosure, a control device includes an acquisition unit that acquires a cultivation shelf temperature, which is the temperature around a cultivation shelf inside a cultivation house; an air conditioning intensity converter that converts a temperature difference between the cultivation shelf temperature and a predetermined target temperature into an air conditioning intensity of an air conditioner that performs air conditioning in the cultivation house; and an air conditioning control unit that calculates an air conditioning intensity for controlling the cultivation shelf temperature to the target temperature based on the cultivation shelf temperature acquired by the acquisition unit and the target temperature, calculates a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity, and commands the calculated set temperature to the air conditioner.

[0007] According to one aspect of this disclosure, a cultivation house includes a building that houses a cultivation shelf, a temperature sensor that measures the temperature around the cultivation shelf, an air conditioner that performs air conditioning in the building, and the above control device.

[0008] According to one aspect of the present disclosure, the control method includes the steps of: acquiring the cultivation shelf temperature, which is the temperature around the cultivation shelves in a cultivation greenhouse; converting the temperature difference between the cultivation shelf temperature and a predetermined target temperature into the air conditioning intensity of an air conditioner that provides air conditioning for the cultivation greenhouse; calculating the air conditioning intensity for controlling the cultivation shelf temperature to the target temperature based on the cultivation shelf temperature and the target temperature acquired in the acquisition step; calculating the set temperature to be commanded to the air conditioner from the calculated air conditioning intensity; and commanding the air conditioner to the set temperature.

[0009] According to the control device, cultivation greenhouse, and control method described above, the temperature inside the cultivation greenhouse can be controlled to a desired target temperature.

[0010] This is a front view showing an example of a cultivation house according to the embodiment. This is a top view showing an example of a cultivation house according to the embodiment. This is a block diagram showing an example of a control device according to the embodiment. This is a diagram illustrating a method for calculating command values ​​for an air conditioner according to the embodiment. This is the first diagram illustrating the control of the operating mode of an air conditioner according to the embodiment. This is the second diagram illustrating the control of the operating mode of an air conditioner according to the embodiment. This is the third diagram illustrating the control of the operating mode of an air conditioner according to the embodiment. This is a diagram illustrating curtain control according to the embodiment. This is a flowchart showing an example of air conditioner control according to the embodiment. This is a flowchart showing an example of air conditioner and ventilation fan control according to the embodiment. This is a flowchart showing an example of curtain control according to the embodiment. This is a flowchart showing an example of dehumidification control according to the embodiment. This is a diagram showing an example of the hardware configuration of a control device according to the embodiment.

[0011] (Summary) The temperature control of the cultivation greenhouse according to this disclosure will be described below with reference to the drawings. Figure 1 is a front view showing an example of a cultivation greenhouse according to the embodiment. Figure 2 is a plan view showing an example of a cultivation greenhouse according to the embodiment. The cultivation greenhouse 100 is a facility for cultivating plants P such as strawberries by taking in sunlight. The cultivation greenhouse 100 includes a building 1, a plurality of cultivation shelves 10, plants P planted on the cultivation shelves 10, an air conditioner 30, an air conditioner 31, a curtain 40, a curtain 41, a fan 42, a ventilation fan 43, and a control device 50. The building 1 houses the cultivation shelves 10 and the plants P. The building 1 is made of transparent material such as vinyl or glass and transmits light of a wavelength (for example, visible light) that allows plants P to perform photosynthesis. The building 1 has a double-layered structure of an inner lining 44 and an outer lining 45, and an indoor space 46 enclosed by the inner lining 44 is formed inside the building 1. The double-layered structure makes it easy to maintain the temperature inside the indoor space 46. The cultivation shelves 10 are arranged inside the indoor space 46. The cultivation shelves 10 are formed such that, for example, the length is in the depth direction (Y-axis direction) of the paper in Figure 1, and multiple cultivation shelves 10 are arranged in parallel inside the indoor space 46 (Figure 2). The ventilation fan 43 is installed so as to connect the outside of the building 1 and the inside of the indoor space 46, enabling ventilation between the inside and outside. This allows for the direct intake of low-temperature, low-humidity outside air, and a cooling effect can be expected. On the other hand, depending on the installation location, ductwork may be required, which can be time-consuming to install, and there is a risk of pests entering because it is in direct contact with the outside. In another embodiment, the ventilation fan 43 may be installed so as to connect the space between the outer lining 45 and the inner lining 44 with the inside of the indoor space 46. When installed in this manner, construction is relatively easy, pests are less likely to enter, and during the daytime in winter, air warmed by sunlight is drawn in between the inner lining 44 and the outer lining 45, so there is no extreme temperature drop, which is advantageous for heating. On the other hand, because relatively high-temperature air is drawn into the indoor space 46 between the inner lining 44 and the outer lining 45, the load is high during cooling operation in summer, which may increase power consumption. Outside the cultivation greenhouse 100, a temperature sensor C6 for measuring the outdoor temperature and a humidity sensor C7 for measuring the outdoor humidity are provided. The temperature sensor C6 and humidity sensor C7 are connected to the control device 50.The temperature sensor C6 outputs the measured ambient temperature to the control device 50. The humidity sensor C7 outputs the measured ambient humidity to the control device 50. The cultivation shelf 10 has a cold air enclosure 11, a shelf section 12, and a support section 13.

[0012] A cool air enclosure 11 is provided for each cultivation shelf 10, enclosing the bottom and sides of the cultivation shelf 10 so that the top of the plants P are open to the inside of the building 1. Inside the cool air enclosure 11, the plants P are placed, and a temperature sensor C1 for measuring the temperature is installed. Preferably, the temperature sensor C1 is installed under the leaves of the plants P, but the installation position of the temperature sensor C1 is not limited to this, and it can be placed at any position inside the cool air enclosure 11. For example, the temperature sensor C1 may be installed above the leaves of the plants P, or it may be installed on the inside of the side of the cool air enclosure 11. For example, one temperature sensor C1 is provided for each cultivation shelf 10, but multiple temperature sensors C1 may be provided for each cultivation shelf 10. A humidity sensor C5 is provided in the indoor space 46. A humidity sensor C5 may be provided for each cultivation shelf 10, or one or more may be installed at any location in the indoor space 46. The humidity measured by the humidity sensor C5 is transmitted to the control device 50. The temperature around the cultivation shelf 10, measured by the temperature sensor C1, is transmitted to the control device 50. The shelf section 12 contains plants P and soil for planting the plants P. The support section 13 supports the shelf section 12.

[0013] Two air conditioners 30 and 31 regulate the temperature inside building 1 (indoor space 46). Air conditioner 30 includes an indoor unit 30a and an outdoor unit 30b, and air conditioner 31 includes an indoor unit 31a and an outdoor unit 31b. The indoor units 30a and 31a are installed inside building 1, and the outdoor units 30b and 31b are installed outside building 1 (outdoors). The following explanation will use the case where air conditioners 30 and 31 cool the inside of building 1 (indoor space 46) as an example. Air conditioners 30 and 31 supply the cooled air after conditioned air to each of the multiple cultivation shelves 10 through ducts 20 and 21. A duct 21 is provided for each cultivation shelf 10 and extends in the longitudinal direction of the cultivation shelf 10 (Figure 2). The duct 20 connects the outlets of air conditioners 30 and 31 to each of the multiple ducts 21. Duct 21 is laid inside the cold air enclosure 11 (below the shelf section 12). Duct 21 is provided with a gas outlet (not shown), from which cold air (arrow 22 in Figure 1) is released. For example, air conditioner 30 has better operating efficiency at low heat loads compared to air conditioner 31, and air conditioner 31 can cool the room to a lower temperature compared to air conditioner 30. The air conditioner consists of two units, but the one with higher efficiency between air conditioner 30 and air conditioner 31 is operated preferentially (described later). Power monitor C4 (Figure 2) is installed on the power supply of air conditioners 30 and 31. Power monitor C4 measures the power consumed by air conditioners 30 and 31 and transmits the measured value to control device 50.

[0014] For use in a plant factory, curtains can be ordinary blackout curtains that evenly cut all light from visible light to infrared rays, or infrared-cutting films that transmit visible light but significantly block infrared rays. In this example, two curtains, curtain 40 and curtain 41, are used, but they can be either blackout curtains or infrared-cutting films, and may be of different types. Curtain 40 is placed on the inside of the ceiling of building 1 and is opened and closed by the control device 50. The open / closed state of curtain 40 can be any degree from fully closed to fully open. Curtain 41 is placed on the inside of curtain 40 on the ceiling of building 1 and is opened and closed by the control device 50. The open / closed state of curtain 41 can be any degree from fully closed to fully open. Fan 42 ventilates the inside and outside of building 1.

[0015] As shown in Figure 2, the air conditioners 30 and 31 are positioned, for example, near the wall surface of the building 1 perpendicular to the longitudinal direction of the cultivation shelves 10 (in Figure 1, for convenience, they are shown near the wall surface along the longitudinal direction of the cultivation shelves 10). Temperature sensors C2 and C3 are positioned on the cultivation shelves 10 that are closest to the air conditioners 30 and 31. Temperature sensor C2 is a temperature sensor provided as part of the air conditioner 30 at the intake port of the air conditioner 30. The air conditioner 30 performs cooling or heating so that the temperature measured by temperature sensor C2 becomes the set temperature commanded to the air conditioner 30. In this embodiment, this temperature sensor C2 is extended to the cultivation shelves 10 and positioned on the cultivation shelves 10. Temperature sensor C3 is a temperature sensor provided as part of the air conditioner 31 at the intake port of the air conditioner 31. The air conditioner 31 performs cooling or heating so that the temperature measured by temperature sensor C3 becomes the set temperature commanded to the air conditioner 31. In this embodiment, the temperature sensor C3 is extended to the cultivation shelf 10 and placed on the cultivation shelf 10.

[0016] (Control device) Figure 3 is a block diagram showing an example of a control device according to the embodiment. The control device 50 includes an acquisition unit 51, an air conditioning control unit 52, a curtain control unit 53, and a storage unit 54. The acquisition unit 51 acquires measured values ​​measured by temperature sensors C1 to C3 and C6, measured values ​​measured by power monitor C4, and measured values ​​measured by humidity sensors C5 and C7. The air conditioning control unit 52 controls the air conditioners 30 and 31. For example, the air conditioning control unit 52 controls the start and stop of the air conditioners 30 and 31, and when operating the air conditioners 30 and 31, controls the operating mode (cooling, heating, fan, etc.) and air conditioning intensity (for example, cooling intensity). The air conditioning control unit 52 controls the start and stop and rotation speed of the fan 42 and the ventilation fan 43. The curtain control unit 53 controls the opening and closing of the curtains 40 and 41. As will be explained later, in order to take in as much natural light as possible during the day, if the temperature of the cultivation shelf 10 (temperature measured by temperature sensor C1) is controlled to the target temperature, one curtain 40 is fully opened and the other curtain 41 is opened and closed as needed. The memory unit 54 stores the measured values ​​of temperature sensors C1 to C3 and power monitor C4 acquired by the acquisition unit 51, as well as threshold values ​​used for control.

[0017] (Control of air conditioners) Next, the control of air conditioners 30 and 31 will be explained. Figure 4 is a diagram illustrating the method for calculating the command value (set temperature) of the air conditioner according to the embodiment. The air conditioning control unit 52 is equipped with a cooling intensity calculator 521. The cooling intensity calculator 521 is a function, table, trained model, etc. that takes a value obtained by subtracting a predetermined target temperature (target temperature around the plant P) from the temperature of the cultivation shelf 10 measured by the temperature sensor C1 (referred to as the cultivation shelf temperature) as input and outputs the cooling intensity (a value obtained by subtracting the temperature of the air conditioner intake from the temperature command value to the air conditioner 30). For example, if the target temperature of the cultivation shelf 10 is 20 degrees and the average value of the temperatures measured by multiple temperature sensors C2 is 23 degrees, the temperature of the cultivation shelf 10 will be about 3 degrees higher than the target temperature. In order to reduce this temperature difference and make the temperature of the cultivation shelf 10 measured by the temperature sensor C2 the target temperature of 20 degrees, it is necessary to increase the cooling intensity of the air conditioner 30, etc. The cooling intensity calculator 521 converts the temperature difference between the cultivation shelf 10 and the target temperature into a cooling intensity to be commanded to the air conditioner 30, etc., and outputs it. The cooling intensity is given by the temperature difference between the temperature currently recognized by the air conditioner 30, etc. (i.e., the temperature measured by temperature sensors C2 and C3) and the command value. For example, suppose that in order to bridge a temperature difference of 3 degrees on the cultivation shelf 10, the temperature of the cold air supplied by the air conditioner 30, etc. needs to be lowered by a certain amount, and in order to do so, the set temperature commanded to the air conditioner 30, etc. needs to be lowered by 2 degrees. In this case, when a temperature difference of 3 on the cultivation shelf 10 is input, the cooling intensity calculator 521 outputs -2. The air conditioning control unit 52 acquires the -2 output by the cooling intensity calculator 521, adds -2 to the temperature measured by temperature sensor C2, and calculates the set temperature to be commanded to the air conditioner 30. The air conditioning control unit 52 commands the air conditioner 30 to the calculated set temperature. Similarly, for the air conditioner 31, the air conditioning control unit 52 adds -2 to the temperature measured by the temperature sensor C3 to calculate the set temperature to command the air conditioner 31. The air conditioning control unit 52 then commands the air conditioner 31 to the calculated set temperature. A cooling intensity calculator 521 is provided for each air conditioner. In other words, a cooling intensity calculator 521 for air conditioner 30 and a cooling intensity calculator 521 for air conditioner 31 are provided according to the capacity and usage environment of each air conditioner 30 and 31, and the air conditioning control unit 52 is equipped with these two cooling intensity calculators 521.In this way, the air conditioning control unit 52 controls the difference between the temperature measured by the temperature sensors (temperature sensors C2, C3) of the air conditioners 30, 31 and the command value (set temperature) to the air conditioners, according to the difference between the average value (or median or mode) of the temperatures measured by the multiple temperature sensors C1 and the target temperature, and adjusts the air conditioning intensity of the air conditioners. If the air conditioners 30, 31 can receive the cooling intensity as a command value, the cooling intensity calculator 521 may output a value to the air conditioners 30, 31 as a command. In this case, for example, air conditioner 30 operates with the set temperature being the temperature obtained by adding the temperature measured by temperature sensor C2 to the received cooling intensity.

[0018] Next, we will explain the operation mode control. Figure 5A is a diagram illustrating the control of the operation mode of the air conditioner according to the embodiment. As described above, in this embodiment, the air conditioner 30, which has good operating efficiency when the heat load is low, is operated preferentially, and when the cooling capacity is insufficient, the air conditioner 31, which has high operating efficiency when the heat load is high, is operated. For example, the air conditioning control unit 52 has a control table 522 as illustrated in Figure 5A. The air conditioning control unit 52 determines the operation mode of the air conditioners 30 and 31 based on the control table 522. Here, T is (cultivation shelf temperature - target temperature of cultivation shelf 10). First, let's assume that T5 ≤ T ≤ T2 at the start of operation. The air conditioning control unit 52 causes the air conditioner 30 to perform cooling operation and the air conditioner 31 to perform fan operation (item 1 in Figure 5A). The air conditioning control unit 52 calculates the set temperature of the air conditioner 30 using the cooling intensity calculator 521 for the air conditioner 30 in the manner described with reference to Figure 4, and commands the air conditioner 30 to the calculated set temperature. As long as the condition T5 ≤ T ≤ T2 is met, the air conditioner 30 continues cooling operation and the air conditioner 31 continues fan operation. When T > T2, the air conditioning control unit 52 switches the air conditioner 31 from fan operation to cooling operation (item 2 in Figure 5A). The air conditioning control unit 52 further calculates the set temperature of the air conditioner 31 using the cooling intensity calculator 521 for the air conditioner 31 in the manner described with reference to Figure 4, and commands the air conditioner 31 to the calculated set temperature. When the temperature of the cultivation shelves decreases due to the cooling operation of the two air conditioners 30 and 31, and T < T3, the air conditioning control unit 52 switches air conditioner 30 from cooling operation to fan operation and switches to standalone cooling operation of air conditioner 31, which is more efficient under high heat load (item 3 in Figure 5A). When the temperature of the cultivation shelves decreases further to T < T4, the air conditioning control unit 52 switches air conditioner 30, which is more efficient under low heat load, from fan operation to cooling operation, and switches air conditioner 31 from cooling operation to fan operation (item 4 in Figure 5A). Air conditioner 30 continues to operate in cooling mode. When the temperature decreases further to T < T5, the air conditioning control unit 52 stops both air conditioners 30 and 31 (item 5 in Figure 5A). When the temperature of the cultivation shelves rises due to the stopping of air conditioners 30 and 31, and T > T1, the air conditioning control unit 52 starts air conditioner 30 to operate in cooling mode and air conditioner 31 to operate in fan mode (item 6 in Figure 5A).Here, T1 to T5 are temperatures such that T2 > T1 > T3 > T4 > T5 holds true, and are arbitrarily set according to the capacity of the air conditioners 30 and 31 and the operating environment. For example, the values ​​of T1 to T5 are determined by experiments and simulation calculations so that the temperature of the cultivation shelf falls within ±2°C of the target temperature of the cultivation shelf 10. The temperature difference between T3, T4, and T5 is set with a certain range (e.g., 0.2°C) so that the period during which one of the air conditioners 30 or 31 operates in cooling mode is not excessively short. T1 to T5 depend on the type of plant P and the environment, but as an example, T5 = -1.0 ± 0.2°C, T4 = -0.8 ± 0.2°C, T3 = -0.6 ± 0.2°C, T1 = -0.5 ± 0.2°C, T2 = +0.5 ± 0.2°C, etc. When T5 ≤ T ≤ T2, cooling is performed using only one air conditioner 30. When T < T3 (which may be lower than T5 ≤ T ≤ T2), cooling is performed using only one air conditioner 31. This is because, compared to the start of operation or when the temperature rises after T < T5 and becomes T5 ≤ T ≤ T2, the situation where T decreases as a result of cooling with both air conditioners 30 and 31, resulting in T < T3, is considered to be an environment with a higher operating load (even though T is lower). In this case, cooling is performed using air conditioner 31, which has higher operating efficiency under relatively high heat load conditions. Furthermore, if T decreases further, the system switches to air conditioner 30, which has higher operating efficiency under relatively low heat load conditions, for cooling. This improves operating efficiency and saves energy.

[0019] Another example of the operating mode control shown in Figure 5B is shown. For example, the air conditioning control unit 52 has a control table 523 illustrated in Figure 5B. First, at the start of operation, the air conditioning control unit 52 causes the air conditioner 30 to perform cooling operation and the air conditioner 31 to perform fan operation (item 1 in Figure 5B). The air conditioning control unit 52 uses a cooling intensity calculator 521 for the air conditioner 30 to calculate the set temperature of the air conditioner 30 in the manner described with reference to Figure 4, and commands the air conditioner 30 to the calculated set temperature. As long as the condition T4 ≤ T ≤ T2 is met, the air conditioner 30 continues cooling operation and the air conditioner 31 continues fan operation. Next, when T > T2, the air conditioning control unit 52 switches the air conditioner 31 from fan operation to cooling operation (item 2 in Figure 5B). The air conditioning control unit 52 further uses the cooling intensity calculator 521 for the air conditioner 31 to calculate the set temperature of the air conditioner 31 in the manner described with reference to Figure 4, and commands the air conditioner 31 to the calculated set temperature. When the temperature of the cultivation shelves decreases due to the cooling operation of the two air conditioners 30 and 31 and T < T3, the air conditioning control unit 52 switches air conditioner 31 from cooling operation to fan operation (item 3 in Figure 5B). Air conditioner 30 continues cooling operation. When the temperature drops further and T < T4, the air conditioning control unit 52 stops both air conditioners 30 and 31 (item 4 in Figure 5B). When the temperature of the cultivation shelves rises due to the stopping of air conditioners 30 and 31 and T > T1, the air conditioning control unit 52 starts air conditioner 30 and operates it in cooling operation, and starts air conditioner 31 and operates it in fan operation (item 5 in Figure 5B). Here, T1 to T4 may be different values ​​from T1 to T4 in Figure 5A, and are temperatures such that T2 > T1 > T3 > T4 holds true, and are determined so that the temperature of the cultivation shelf falls within ±2°C of the target temperature of the cultivation shelf 10. The control described with reference to Figures 4, 5A, and 5B is performed during the day (for example, from sunrise to sunset) with a predetermined control cycle, and a different control is performed at night. For example, at night, the air conditioner 31 is used to control the temperature of the indoor space 46 to a lower temperature than during the day (for example, 10°C).

[0020] Furthermore, another example of the operating mode control shown in Figure 5C is presented. In this control, a ventilation fan 43 is used in addition to the air conditioners 30 and 31. The control device 50 operates the air conditioners 30 and 31 and the ventilation fan 43 in coordination to control the temperature of the cultivation shelves to the target temperature. Specifically, when the outside air temperature is lower than the target temperature, the ventilation fan 43 is activated to draw outside air into the indoor space 46, thereby cooling the plants P, and the operating intensity of the air conditioners 30 and 31 is reduced or stopped accordingly, thereby reducing the power required for temperature control. The control device 50 adjusts the number of circuits of the ventilation fan 43 according to the difference between the cultivation shelf temperature and the target temperature, and uses the ventilation fan 43 as a pseudo-air conditioner. From the viewpoint of controlling the cultivation shelf temperature with high precision, it is desirable that the rotation speed of the ventilation fan 43 can be continuously changed from low to high. The following explanation assumes that the rotation speed of the ventilation fan 43 can be switched in multiple stages or that the rotation speed can be continuously controlled. However, if the rotation speed cannot be controlled and only ON / OFF switching is possible, the system may simulate "high" and "low" ventilation speeds by varying the number of operating fans. The number of ventilation fans 43 may be more than two (especially when controlling by varying the number of operating fans).

[0021] Even in the control example shown in Figure 5C, of ​​the two air conditioners 30 and 31, air conditioner 30 is operated preferentially, and if the cooling capacity is insufficient, air conditioner 31, which has higher operating efficiency under high heat load conditions, is operated. For example, the air conditioning control unit 52 has a control table 524 as illustrated in Figure 5C. Based on the control table 524, the air conditioning control unit 52 determines the operating modes of the air conditioners 30 and 31 and the ventilation fan 43. Here, (cultivation shelf temperature - target temperature of cultivation shelf 10) is denoted as T, and (outside air temperature measured by temperature sensor C6 - target temperature of cultivation shelf 10) is denoted as OT. The condition for operating the ventilation fan 43 (referred to as the ventilation fan operating condition) is that "OT ≤ X°C and / or outside air humidity measured by humidity sensor C7 ≤ Y%". X°C is a threshold set to determine that the outside air temperature is lower than the target temperature of cultivation shelf 10, and Y% is a threshold set to determine that the outside air humidity is sufficiently low. First, it is assumed that T5 ≤ T ≤ T2 at the start of operation. If the ventilation fan operating conditions are not met, the air conditioning control unit 52 causes the air conditioner 30 to perform cooling operation, the air conditioner 31 to perform fan operation, and the ventilation fan 43 to stop (item 1 in Figure 5C). For the air conditioner 30 that is performing cooling operation, the air conditioning control unit 52 uses the cooling intensity calculator 521 for the air conditioner 30 to calculate the set temperature of the air conditioner 30 in the manner described with reference to Figure 4, and commands the air conditioner 30 to the calculated set temperature. If the ventilation fan operating conditions are met, the air conditioning control unit 52 causes the air conditioner 30 to perform cooling operation, stops the air conditioner 31, and operates the ventilation fan 43 (item 2 in Figure 5C). At this time, if T is close to T5, the air conditioning control unit 52 sets the rotation speed of the ventilation fan 43 to a low setting, and if T is close to T2, it sets the rotation speed of the ventilation fan 43 to a high setting and operates it. If the temperature of the cultivation shelves rises and T > T2, and the conditions for ventilation fan operation are not met, the air conditioning control unit 52 switches the air conditioner 31 from fan operation to cooling operation and stops the ventilation fan 43 (item 3 in Figure 5C). The air conditioning control unit 52 uses the cooling intensity calculator 521 for the air conditioner 31 to calculate the set temperature of the air conditioner 31 in the manner described with reference to Figure 4, and commands the air conditioner 31 to set the calculated set temperature. If the conditions for ventilation fan operation are met, the air conditioning control unit 52 has the air conditioner 30 perform cooling operation, the air conditioner 31 perform fan operation, and the ventilation fan 43 operate (item 4 in Figure 5C). At this time, the air conditioning control unit 52 operates the ventilation fan 43 at a high rotation speed.If these controls cause the temperature of the cultivation shelves to drop and T < T3, and the conditions for ventilation fan operation are not met, the air conditioning control unit 52 switches the air conditioner 30 from cooling operation to fan operation, switches the air conditioner 31 to cooling operation, and stops the ventilation fan 43 (item 5 in Figure 5C). If the conditions for ventilation fan operation are met, the air conditioning control unit 52 either makes the air conditioner 30 perform cooling operation or stops it, stops the air conditioner 31, and operates the ventilation fan 43 at a high rotation speed (item 6 in Figure 5C). Whether to make the air conditioner 30 perform cooling operation or stop it may be predetermined, or it may be switched according to T, OT, and outside humidity. If the temperature of the cultivation shelves drops further and T < T4, and the ventilation fan operating conditions are not met, the air conditioning control unit 52 switches the air conditioner 30 from fan operation to cooling operation, switches the air conditioner 31 from cooling operation to fan operation, and stops the ventilation fan 43 (item 7 in Figure 5C). If the ventilation fan operating conditions are met, the air conditioning control unit 52 stops the air conditioners 30 and 31 and operates the ventilation fan 43 at a higher rotation speed (item 8 in Figure 5C). If the temperature drops further and T < T5, regardless of whether the ventilation fan operating conditions are met or not, the air conditioning control unit 52 stops the air conditioners 30 and 31 and the ventilation fan 43 (item 9 in Figure 5C). When the temperature of the cultivation shelves rises due to the stopping of air conditioners 30, 31 and ventilation fan 43, and T > T1, if the ventilation fan operating conditions are not met, the air conditioning control unit 52 starts air conditioner 30 and operates it in cooling mode, starts air conditioner 31 and operates it in fan mode, and stops ventilation fan 43 (item 10 in Figure 5C). If the ventilation fan operating conditions are met, the air conditioning control unit 52 stops air conditioners 30 and 31 and operates ventilation fan 43 (item 11 in Figure 5C). At this time, if T is close to T1, the air conditioning control unit 52 sets the rotation speed of ventilation fan 43 to a low setting, and if T is close to T2, it sets the rotation speed of ventilation fan 43 to a high setting. In this way, by using ventilation fan 43 to take in cool outside air, it is possible to further improve operating efficiency and save energy compared to the control shown in Figures 5A and 5B.

[0022] In this embodiment, the explanation assumes the use of two air conditioners, but if the indoor space 46 is small or the temperature control load is low, one air conditioner may be sufficient. In that case, an air conditioner with performance that meets the requirements will be selected according to the temperature range required for plant P cultivation and the size of the indoor space 46.

[0023] In the control illustrated in Figures 5A and 5B, both air conditioners 30 and 31 are stopped when T < T5 (Figure 5A) or T < T4 (Figure 5B). However, if T < T5 (Figure 5A), etc., and the humidity measured by the humidity sensor C5 is higher than a predetermined threshold, the air conditioning control unit 52 may operate the air conditioners 30 and 31 in fan mode instead of stopping them. In this case, the air conditioning control unit 52 operates the fan 42 and the ventilation fan 43 at a predetermined rotation speed to bring outside air into the indoor space 46. By operating the ventilation fan 43, etc., to ventilate with the outside air, and operating the air conditioners 30 and 31 in fan mode to circulate the air in the indoor space 46, the humidity in the indoor space 46 can be reduced to a level appropriate for the cultivation of plants P. When ventilating with the outside air, windows may be opened, and other fans or the like may be used to bring in outside air. You may operate only one of the air conditioners 30 and 31 in fan mode and stop the other.

[0024] Even if the target temperature of the cultivation shelf 10 is achieved and the temperature drops further, it is conceivable to keep the air conditioner 30 running in fan mode. However, in this embodiment, when T < T5 (Figure 5A) or T < T4 (Figure 5B) occurs (or when T < T5 etc. and humidity is low), both air conditioners 30 and 31 are stopped. This makes it possible to save power. For example, in the morning or on rainy days, the temperature inside the indoor space 46 may become sufficiently low. In such situations, instead of running the air conditioners 30 and 31 in fan mode, completely stopping them reduces power consumption compared to when the air conditioners 30 and 31 are operated day and night.

[0025] For plant P to grow, in addition to temperature, humidity must be controlled within an appropriate range. High humidity increases the likelihood of disease, hinders nutrient absorption from the roots, and reduces photosynthesis. In plant factories, many seedlings are planted to increase productivity, but in such cases, the amount of water transpired from the leaves increases. Even in such cases, it is necessary to maintain an appropriate humidity level inside the cultivation greenhouse 100. To achieve this, it is necessary to remove moisture by cooling with an air conditioner or by mechanical means such as a dehumidifier in the cultivation greenhouse 100, which is designed to increase CO2 concentration and prevent the introduction of pests and diseases. However, in situations where the temperature inside the greenhouse is low, such as in autumn and winter, the required cooling intensity is reduced, and the amount of dehumidification that can be achieved by cooling decreases, resulting in high humidity inside the cultivation greenhouse 100. Therefore, the air conditioning control unit 52 may adjust the temperature and humidity inside the indoor space 46 by operating one of the air conditioners 30 and 31 in heating mode and the other in cooling mode under predetermined conditions. For example, during the autumn and winter seasons, or when conditions such as high daytime humidity or weak daytime cooling intensity are met, one unit is operated in heating mode and the other in cooling mode to dehumidify the indoor space 46. In other words, to ensure sufficient dehumidification during low-temperature periods, one of the two units is used to raise the temperature inside the greenhouse, and the increased temperature is then cooled by cooling to perform dehumidification by cooling. At this time, the air conditioning control unit 52 may calculate the vapor pressure deficit from the outside air humidity measured by the humidity sensor C7, and if the vapor pressure deficit is below the target value, it may operate the heating operation at a constant intensity, and if the vapor pressure deficit is above the target value, it may operate the fan operation. As another control method to reduce humidity, dehumidification of the indoor space 46 may be performed by operating one unit in cooling mode and the other in fan mode. Moisture removal by cooling depends on moisture removal from the cooling liquid pipe in the refrigerant circuit. Since the amount of moisture removed from the cooling liquid pipe is greater at higher cooling intensity, instead of operating both air conditioners at low cooling intensity, one unit is operated at high cooling intensity. When dehumidifying using this control method, it is acceptable not to switch the two units to cooling operation even if the temperature rises. Furthermore, as another control method, dehumidification may be performed in the following way, provided that the outside air humidity is low. That is, one of the two ventilation fans 43 is used as an exhaust fan and the other as an intake fan, and both ventilation fans 43 are operated. This creates convection within the indoor space 46.This convection is used to dehumidify the indoor space 46 by using a ventilation fan 43 installed at the top of the indoor space 46 to replace only the air at the top in one direction. Here, the specific gravity of water vapor relative to air is 0.6, and the specific gravity of CO2 is 1.5. Because the evaporated water vapor is lighter, it moves to the top of the indoor space 46, mixes with the dry air (outside air) taken in by the intake ventilation fan 43 installed at the top through natural convection, and is discharged to the outside of the indoor space 46 by the exhaust ventilation fan 43. On the other hand, because the CO2 that we want to maintain at a high concentration is heavier, it accumulates at the bottom of the indoor space 46 and does not circulate, so it is not discharged into the indoor space 46. With this mechanism, when the humidity outside the greenhouse is low and there are few pests, it is possible to efficiently dehumidify without lowering the CO2 inside the greenhouse and without letting pests in. With this method, dehumidification can be performed without relying on dehumidification by air conditioning, so the cooling intensity of the air conditioner 30 etc. can be reduced, and power consumption can be reduced. In this method, the two ventilation fans 43 need to be placed at a high position. Insect filters may be attached to the ventilation fans 43.

[0026] (Control of the Curtains) Next, the control of the curtain 41 will be explained. For the cultivation of plants P, it is desirable that as much visible light as possible reaches the plants P. From this perspective, basically the curtain 40 is kept fully open, and the opening degree of the curtain 41 is controlled in the manner described below, thereby bringing the temperature of the cultivation shelf 10 closer to the target temperature together with the air conditioners 30 and 31. If the target temperature still cannot be achieved, the target temperature is achieved by opening and closing the curtain 40 in the same manner.

[0027] Figure 6 is a diagram illustrating curtain control according to an embodiment. The curtain control unit 53 includes an opening / closing control value calculator 531. The opening / closing control value calculator 531 is a function, table, or trained model that outputs the opening / closing speed and direction of the curtain when it receives a value obtained by subtracting the target temperature from the cultivation shelf temperature measured by the temperature sensor C1. For example, if the cultivation shelf temperature is higher than the target temperature, closing the curtain 41 can block infrared rays that cause the temperature inside the greenhouse to rise, thereby reducing the load on the air conditioners 30 and 31. Therefore, when a positive value is input to the opening / closing control value calculator 531, the opening / closing control value calculator 531 outputs "closed" as the opening / closing direction of the curtain and outputs a predetermined curtain closing speed (speed at which the curtain closes). Regarding the curtain closing speed, a faster value may be output if (cultivation shelf temperature - target temperature) is large. For example, if the cultivation shelf temperature is lower than the target temperature, the opening / closing control value calculator 531 outputs "open" as the opening / closing direction of the curtain and outputs a predetermined curtain opening speed (speed at which the curtain opens). The smaller the (cultivation shelf temperature - target temperature), the faster the output value may be. In order to capture as much sunlight as possible without excessive heat load, for example, if the difference between the cultivation shelf temperature and the target temperature is within a predetermined range (for example, if cultivation shelf temperature - target temperature is positive and sufficiently small), the opening / closing control value calculator 531 may output 0 as the curtain opening / closing speed. In this case, the opening and closing of the curtain stops and is maintained at the current opening degree. If the difference between the cultivation shelf temperature and the target temperature is 0, the opening / closing control value calculator 531 may output "open" as the curtain opening / closing direction and output a predetermined curtain opening speed.

[0028] The curtain opening and closing control, as explained with reference to Figure 6, is performed during the day with a predetermined control cycle and is fully closed at night. During the day, the curtain control unit 53 starts closing the curtain when the heat load (temperature difference T) inside the greenhouse is excessive, and stops opening and closing when the heat load becomes appropriate. By opening and closing the curtain based on the heat load inside the greenhouse, the maximum amount of solar radiation can be taken in according to the environmental conditions. For example, during the day, when the temperature difference T (cultivation shelf temperature - target temperature) becomes positive and the opening / closing control value calculator 531 outputs a command value instructing the curtain to be closed, the opening / closing control value calculator 531 closes the curtain at a speed based on this command value. Even during this operation, the temperature measured by the temperature sensor C2 is transmitted to the control device 50, and the curtain control unit 53 calculates the temperature difference T and inputs it to the opening / closing control value calculator 531. The curtain control unit 53 controls the opening and closing of the curtain according to the newly output command value (curtain opening / closing speed, opening / closing direction) from the opening / closing control value calculator 531. If the output command value is the same as the command value output in the previous control cycle, the curtain control unit 53 continues the opening and closing control of the curtain up to that point. When the newly output curtain opening and closing speed becomes 0, the curtain control unit 53 stops opening and closing the curtain and maintains the current opening degree. In this embodiment, the control of the air conditioners 30 and 31 and the control of the curtains (curtains 40 and 41) are performed in parallel and independently based on the heat load inside the greenhouse (temperature difference T: cultivation shelf temperature - target temperature).

[0029] (Operation) Next, the temperature control of the cultivation shelves will be explained with reference to Figures 7A, 7B, and 8. Figure 7A is a flowchart showing an example of air conditioner control according to the embodiment. The control device 50 repeatedly performs the following processes during the day at a predetermined control cycle. The acquisition unit 51 acquires the cultivation shelf temperature from a plurality of temperature sensors C1 (step S1). The acquisition unit 51 acquires the intake port temperature of the air conditioners 30 and 31 from temperature sensors C2 and C3. The acquisition unit 51 outputs the acquired plurality of cultivation shelf temperatures and the intake port temperatures of the air conditioners 30 and 31 to the air conditioning control unit 52. The air conditioning control unit 52 calculates the average value of the plurality of cultivation shelf temperatures.

[0030] Next, the air conditioning control unit 52 subtracts the target temperature of the cultivation shelf 10 from the calculated average temperature of the cultivation shelf. Let this temperature difference be T (T = average temperature of cultivation shelf - target temperature of cultivation shelf 10). Based on the temperature difference T and the control table 522 in Figure 5A or Figure 5B, the air conditioning control unit 52 determines the operating mode of the air conditioners 30 and 31 (step S2).

[0031] Next, the air conditioning control unit 52 calculates the command value for the air conditioner (step S3). Specifically, the air conditioning control unit 52 inputs the temperature difference T to the cooling intensity calculator 521 for the air conditioner 30 and obtains the cooling intensity to be imposed on the air conditioner 30 (command value - air conditioner intake temperature). The air conditioning control unit 52 adds the intake temperature of the air conditioner 30 (temperature measured by the temperature sensor C2) to the value output by the cooling intensity calculator 521 to calculate the set temperature to be commanded to the air conditioner 30. When operating the air conditioner 31 in cooling mode, the air conditioning control unit 52 inputs the temperature difference T to the cooling intensity calculator 521 for the air conditioner 31 and obtains the cooling intensity to be imposed on the air conditioner 31 (command value - air conditioner intake temperature). The air conditioning control unit 52 adds the air intake temperature of the air conditioner 31 (temperature measured by the temperature sensor C3) to the value output by the cooling intensity calculator 521 for the air conditioner 31 to calculate the set temperature to command to the air conditioner 31.

[0032] Next, the air conditioning control unit 52 outputs command values ​​to the air conditioners 30 and 31 and controls the air conditioners 30 and 31 (step S4). The air conditioning control unit 52 operates (cools or blows) or stops the air conditioners 30 and 31 in the operating mode determined in step S2. The air conditioning control unit 52 commands the air conditioner 30 or 31 that is operating in cooling mode to the set temperature calculated in step S3. Even if the temperature conditions for stopping the air conditioners 30 and 31 are met, if the humidity is high, the air conditioners 30 and 31 may be operated in blower mode.

[0033] Next, the air conditioning control unit 52 determines whether or not to terminate the air conditioning control (step S5). For example, if it is during the time period from sunrise to sunset, the air conditioning control unit 52 determines to continue the air conditioning control; otherwise, it determines to terminate the air conditioning control shown in Figure 7A. If it is determined to continue the air conditioning control (step S5; No), the process from step S1 is repeated. If it is determined to terminate the air conditioning control (step S5; Yes), the air conditioning control shown in Figure 7A is terminated.

[0034] Figure 7B is a flowchart showing an example of air conditioner and ventilation fan control according to the embodiment. The control device 50 repeatedly performs the following processes during the day at a predetermined control cycle. The acquisition unit 51 acquires the cultivation shelf temperature from a plurality of temperature sensors C1, the outside air temperature from temperature sensor C6, and the outside air humidity from humidity sensor C7 (step S1'). The acquisition unit 51 acquires the intake port temperatures of the air conditioners 30 and 31 from temperature sensors C2 and C3. The acquisition unit 51 outputs the acquired plurality of cultivation shelf temperatures, outside air temperature, outside air humidity, and intake port temperatures of the air conditioners 30 and 31 to the air conditioning control unit 52. The air conditioning control unit 52 calculates the average value of the plurality of cultivation shelf temperatures.

[0035] Next, the air conditioning control unit 52 subtracts the target temperature of the cultivation shelf 10 from the calculated average temperature of the cultivation shelf to calculate the temperature difference T. The air conditioning control unit 52 subtracts the target temperature of the cultivation shelf 10 from the outside air temperature to calculate the temperature difference OT. Based on the temperature difference T, temperature difference OT, outside air humidity, and the control table 524 in Figure 5C, the air conditioning control unit 52 determines the operating modes of the air conditioners 30, 31 and the ventilation fan 43 (step S2').

[0036] Next, the air conditioning control unit 52 calculates command values ​​for the air conditioners and the ventilation fans (step S3'). For the air conditioners 30 and 31, the procedure is the same as in step S2 in Figure 7A. For the ventilation fan 43, for example, if the rotation speed of the ventilation fan 43 can be switched between low speed, medium speed, and high speed, the air conditioning control unit 52 operates the ventilation fan 43 at high speed based on the control table 524 in Figure 5C. For item 2 of the control table 524, for example, a temperature range divided into three parts from T5 to T2 is prepared in advance, and the command value is set to low speed when the temperature difference T is in the lowest temperature range, medium speed when it is in the middle temperature range, and high speed when it is in the high temperature range. The same applies to item 11 of the control table 524. If the rotation speed of the ventilation fan 43 can be continuously changed, for items 2 and 11 of the control table 524, a table or function that associates the value of the temperature difference T with the rotation speed of the ventilation fan 43 may be prepared, and the rotation speed corresponding to the temperature difference T may be obtained by referring to this table, etc., and the obtained rotation speed may be used as the command value for the ventilation fan 43. Next, the air conditioning control unit 52 outputs command values ​​to the air conditioners 30 and 31 and the ventilation fan 43, and controls the air conditioners 30 and 31 and the ventilation fan 43 (step S4'). Next, the air conditioning control unit 52 determines whether or not to terminate the control of the air conditioners and the ventilation fan (step S5'). If it is determined to continue the control (step S5'; No), the process from step S1' is repeated. If it is determined to terminate the control (step S5'; Yes), the control shown in Figure 7B is terminated.

[0037] Figure 8 is a flowchart showing an example of curtain control according to the embodiment. The control device 50 repeatedly performs the following processes at a predetermined control cycle during the daytime. The acquisition unit 51 acquires the cultivation shelf temperature from a plurality of temperature sensors C1 (step S11). The acquisition unit 51 outputs the acquired plurality of cultivation shelf temperatures to the curtain control unit 53. The curtain control unit 53 calculates the average value of the plurality of cultivation shelf temperatures.

[0038] Next, the curtain control unit 53 subtracts the target temperature of the cultivation shelf 10 from the calculated average temperature of the cultivation shelf. Let this temperature be T. Based on the temperature difference T and the opening / closing control value calculator 531, the curtain control unit 53 determines the opening / closing direction and opening / closing speed of the curtain (step S12). Specifically, the curtain control unit 53 inputs the temperature difference T to the opening / closing control value calculator 531 for the curtain 41 to obtain the curtain opening / closing direction and curtain opening / closing speed for the curtain 41. Based on the value output by the opening / closing control value calculator 531, the curtain control unit 53 controls the opening / closing or stopping of the curtain 41 (step S13).

[0039] Next, the curtain control unit 53 determines whether or not to terminate the curtain control (step S14). For example, if it is during the time period from sunrise to sunset, the curtain control unit 53 determines to continue the curtain control; otherwise, it determines to continue the curtain control. If it determines to continue the curtain control (step S14; No), the process from step S11 is repeated. If it determines to terminate the curtain control (step S14; Yes), the curtain control shown in Figure 8 is terminated.

[0040] Here, the curtain 41 is opened and closed according to the temperature difference T. However, if the temperature difference T is large even when the curtain 41 is fully closed (or closed to a predetermined degree or more), the curtain control unit 53 keeps the curtain 41 fully closed (or closed to a predetermined degree or more) and controls the opening and closing of the curtain 40 according to the temperature difference T. At this time, the curtain control unit 53 controls the opening and closing of the curtain 40 according to the flowchart in Figure 8.

[0041] As described above, infrared-cutting films and blackout curtains can be used for curtains 40 and 41. For example, both curtains 40 and 41 may be infrared-cutting films, or both may be blackout curtains. When using different types of curtains, in order to capture as much sunlight as possible, curtain 40 can be a blackout curtain and curtain 41 can be an infrared-cutting film, as explained using Figures 6 and 8.

[0042] Next, an example of humidity control for cultivation shelves will be described with reference to Figure 9. Figure 9 is a flowchart showing an example of humidity control according to the embodiment. The control device 50 repeatedly performs the following processes at a predetermined control cycle during the daytime (from sunrise to sunset). The time period during which dehumidification control can be performed is limited to "daytime (from sunrise to sunset)", and dehumidification control is not performed at night even if the humidity is high. The air conditioning control unit 52 determines whether the conditions for performing dehumidification operation are met (step S21). For example, the air conditioning control unit 52 determines to perform dehumidification operation if any of the following conditions (a) to (d) are met. (a) The humidity measured by the humidity sensor C5 is above a predetermined level. (b) For the past few days, there have been many periods of high humidity during the daytime (from sunrise to sunset). For example, the average humidity from sunrise to sunset for the last three days is above a predetermined value, or there have been periods of a predetermined length of time or longer where the humidity is above a predetermined value. (c) For the past few days, the cooling utilization rate (cooling power consumption) of the air conditioners 30 and 31 has been low. (Cooling intensity is low) For example, the amount of power consumed over three days as measured by the power monitor C4 is below a predetermined value. (d) It is a season when sunlight is weak and the heat load is low, such as in autumn or winter, and cooling is not used as much. Such a season can be determined based on the built-in calendar of the control device 50, for example, if it is from October to March, or if it is a season in which dehumidification operation is performed when the temperature outside the building 1 is within a predetermined range.

[0043] When the execution conditions for the dehumidification operation are not satisfied (step S21; No), the process of FIG. 9 ends. When the execution conditions for the dehumidification operation are satisfied (step S21; Yes), the air conditioning control unit 52 operates one unit in the heating operation and the other unit in the cooling operation (step S22). In order to ensure the dehumidification amount during the low temperature period, one of the two units is used to increase the temperature of the indoor space 46, and the increased temperature is cooled by the cooling to perform dehumidification by the cooling. For the heating operation, the operation is performed by setting a predetermined set temperature. When the saturation difference is below the target value, this heating operation is continued, and when the saturation difference becomes above the target value, it may be switched from the heating operation to the blowing operation. For the cooling operation, the operation may be performed at the cooling intensity described with reference to FIGS. 5A and 5B, or when the humidity does not sufficiently decrease with such an operation, the cooling intensity may be temporarily increased to prioritize dehumidification. The heating operation is executed for the purpose of continuously supplying a certain amount of heat, and the control to keep the humidity and temperature within the target range is achieved by the cooling operation. Therefore, it is desirable to use an air conditioner with good response (for example, the air conditioner 30) for the cooling that performs fine control and an air conditioner with relatively poor response (for example, the air conditioner 31) for the heating. This dehumidification operation may be performed while controlling the humidity to be within a predetermined range, or the dehumidification operation may be performed only for a predetermined time within one hour.

[0044] Next, the control device 50 determines whether the end condition for the dehumidification operation is satisfied (step S23). For example, when the time zone becomes nighttime, the humidity drops below a predetermined value, or the temperature rises above a predetermined value, it is determined to end the dehumidification operation. When the end condition is satisfied (step S23; Yes), the dehumidification operation ends. Otherwise (step S23; No), the process from step S22 is repeated. According to the process of FIG. 9, in seasons when the humidity is high, etc., the temperature and humidity in the indoor space 46 can be controlled within a range appropriate for the cultivation of the plant P.

[0045] The air conditioning control unit 52 may dehumidify the indoor space 46 by having one of the air conditioners 30 and 31 perform cooling operation and the other perform fan operation when any of conditions (a) to (d) are met. The air conditioning control unit 52 may also dehumidify the indoor space 46 by operating the exhaust fan 43 and the intake fan 43 when any of conditions (a) to (d) are met.

[0046] (Effects) As described above, according to this embodiment, the operating mode and cooling intensity of the air conditioners 30 and 31 are determined based on the temperature difference T between the cultivation shelf temperature and the target temperature, and the air conditioners 30 and 31 are controlled based on these. This makes it possible to control the temperature of the cultivation shelf 10 to a target temperature suitable for the cultivation of plants P. The opening and closing direction and opening and closing speed of the curtains 40 and 41 are determined based on the temperature difference T between the cultivation shelf temperature and the target temperature, and the opening and closing of the curtains 40 and 41 are controlled based on these. This reduces the load on the air conditioners 30 and 31, and makes it possible to more effectively control the temperature of the cultivation shelf 10 to a target temperature suitable for the cultivation of plants P. The yield of plants P can be improved by always taking in maximum sunlight while maintaining the leaf temperature of the cultivation shelf 10 at the target temperature.

[0047] Regarding the installation of temperature sensors C2 and C3 extending from air conditioners 30 and 31 to the cultivation shelf 10, if temperature sensor C1 malfunctions, the temperatures measured by temperature sensors C2 and C3 can be used instead. For example, the air conditioning control unit 52 inputs the average value of the temperatures measured by temperature sensors C2 and C3 into the cooling intensity calculator 521 for air conditioner 30 to obtain the cooling intensity for air conditioner 30. Then, the air conditioning control unit 52 adds the temperature measured by temperature sensor C2 (the intake temperature of air conditioner 30) to the output cooling intensity to calculate the set temperature to command to air conditioner 30. The air conditioning control unit 52 inputs the average value of the temperatures measured by temperature sensors C2 and C3 into the cooling intensity calculator 521 for air conditioner 31 to obtain the cooling intensity for air conditioner 31. The air conditioning control unit 52 then adds the temperature measured by the temperature sensor C3 (the intake temperature of the air conditioner 31) to the output cooling intensity to calculate the set temperature to command the air conditioner 31. This allows the temperature of the cultivation shelves to be controlled to the desired target temperature even when the temperature sensor C1 is unavailable due to malfunction or maintenance.

[0048] In the above-described embodiment, the case of cooling the inside of the cultivation house has been described as an example. However, the same control can also be applied when heating the inside of the cultivation house. For example, when the air-conditioning control unit 52 inputs the cultivation shelf temperature - target temperature, it calculates the set temperature to be commanded to the air conditioners 30 and 31 based on a heating intensity calculator that outputs the heating intensity. For example, the heating intensity calculator outputs, as the heating intensity, the temperature difference between the temperature measured by the temperature sensor provided in the air conditioner and the set temperature to be commanded to the air conditioner according to the temperature difference between the cultivation shelf temperature and the target temperature. For example, if the temperature measured by the temperature sensor C1 is 20 degrees and the target temperature is 25 degrees, for example, 3 is output as the heating intensity corresponding to this temperature difference of 5. The air-conditioning control unit 52 acquires the 3 output by the heating intensity calculator, adds 3 to the temperature measured by the temperature sensor C2, and calculates the set temperature to be commanded to the air conditioner 30. If the temperature difference becomes higher than a predetermined value (if the cultivation shelf temperature becomes higher than the target temperature by a predetermined value), the air-conditioning control unit 52 stops the air conditioners 30 and 31. At this time, if the humidity is higher than the threshold value, the air conditioners 30 and 31 may be operated in a blowing mode. When setting so that both the cooling operation and the heating operation can be performed depending on the temperature, it is necessary to set the temperature difference T5 (cultivation shelf temperature - target temperature) for the heating operation to stop heating to a value smaller than the temperature difference T1 for the cooling operation to start cooling, so that the execution of the cooling operation and the heating operation is not determined simultaneously. When the curtain control unit 53 inputs the cultivation shelf temperature - target temperature, it controls the opening and closing of the curtains (curtains 40 and 41) based on an opening / closing control value calculator that outputs the opening / closing direction and the opening / closing speed of the curtain (open the curtain when the heat load is high).

[0049] Figure 10 shows an example of the hardware configuration of the control device according to each embodiment. The computer 900 includes a CPU 901, main memory 902, auxiliary storage 903, input / output interface 904, and communication interface 905. The control device 50 described above is implemented in the computer 900. The functions described above are stored in the auxiliary storage 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage 903, expands it in the main memory 902, and executes the above processing according to the program. The CPU 901 allocates a storage area in the main memory 902 according to the program. The CPU 901 allocates a storage area in the auxiliary storage 903 to store the data being processed according to the program.

[0050] A program for realizing all or part of the functions of the control device 50 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed to perform processing by each functional unit. Here, "computer system" includes hardware such as the OS and peripheral devices. If a WWW system is used, "computer system" also includes the homepage provisioning environment (or display environment). "Computer-readable recording medium" refers to portable media such as CDs, DVDs, USBs, and storage devices such as hard disks built into the computer system. If this program is distributed to the computer 900 via a communication line, the computer 900 that receives the distribution may load the program into the main memory 902 and execute the above processing. The above program may be for realizing part of the functions described above, and may also be for realizing the above functions in combination with a program already recorded in the computer system.

[0051] As described above, several embodiments relating to this disclosure have been explained, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0052] <Note> The control device, cultivation house, and control method described in each embodiment can be understood, for example, as follows.

[0053] (1) The control device according to the first embodiment includes: an acquisition unit that acquires the temperature around the cultivation shelves in the cultivation greenhouse, which is the temperature of the cultivation shelves; an air conditioning intensity converter that converts the temperature difference between the cultivation shelves temperature and a predetermined target temperature into the air conditioning intensity of an air conditioner that provides air conditioning for the cultivation greenhouse; and an air conditioning control unit that calculates the air conditioning intensity for controlling the cultivation shelves temperature to the target temperature based on the cultivation shelves temperature acquired by the acquisition unit and the target temperature, calculates a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity, and commands the calculated set temperature to the air conditioner. This makes it possible to control the cultivation shelves temperature to the target temperature.

[0054] (2) The control device according to the second embodiment is the control device of (1), wherein the air conditioning intensity converter outputs the temperature difference between the temperature measured by the temperature sensor provided in the air conditioner and the set temperature to be commanded to the air conditioner as the air conditioning intensity. This makes it possible to calculate the set temperature to be commanded to the air conditioner.

[0055] (3) The control device according to the third embodiment is the control device according to (1) to (2), further comprising an operating mode determination unit that determines whether the air conditioner will perform cooling operation, heating operation, or fan operation based on the temperature difference between the cultivation shelf temperature and the target temperature, and the air conditioning control unit calculates the air conditioning intensity when the operating mode determination unit determines to perform cooling operation or heating operation. This makes it possible to have only the minimum necessary air conditioners perform cooling or heating operation, thereby saving energy.

[0056] (4) The control device according to the fourth embodiment is the control device according to (1) to (3), further comprising an operating mode determination unit that determines whether the air conditioner will perform cooling operation, heating operation, fan operation, or stop operation based on the temperature difference obtained by subtracting the target temperature from the cultivation shelf temperature, wherein the operating mode determination unit decides to stop the air conditioner when the temperature difference falls below a predetermined negative threshold when the air conditioner is performing cooling operation, and decides to stop the air conditioner when the temperature difference falls above a predetermined positive threshold when the air conditioner is performing heating operation. This makes it possible to suppress the power consumption of the air conditioner.

[0057] (5) The control device according to the fifth embodiment is the control device according to (1) to (3), wherein when the outside air temperature is below a predetermined temperature and / or the outside air humidity is below a predetermined humidity, the air conditioning control unit reduces the operating intensity of the air conditioner and operates a ventilation fan provided to ventilate the air inside the cultivation greenhouse with the outside air. This makes it possible to suppress the power consumption of the air conditioner.

[0058] (6) The control device according to the sixth embodiment is the control device according to (4), wherein the operating mode determination unit decides to operate the air conditioner in fan mode instead of stopping the air conditioner when the humidity inside the cultivation greenhouse exceeds a predetermined threshold. This makes it possible to reduce the humidity inside the cultivation greenhouse.

[0059] (7) The control device according to the seventh embodiment is the control device according to (1) to (6), wherein the air conditioning control unit controls two air conditioners, and when the humidity inside the cultivation greenhouse exceeds a predetermined threshold or the cooling load by the air conditioners falls below a predetermined value, the air conditioning control unit operates one of the air conditioners in heating mode and the remaining air conditioner in cooling mode to reduce the humidity inside the cultivation greenhouse. This reduces the humidity inside the cultivation greenhouse.

[0060] (8) The control device according to the eighth aspect is the control device according to (1) to (7), wherein the air conditioning control unit controls two air conditioners, and when the humidity inside the cultivation greenhouse exceeds a predetermined threshold, the air conditioning control unit operates one of the air conditioners in cooling mode and the remaining air conditioner in fan mode to reduce the humidity inside the cultivation greenhouse. This reduces the humidity inside the cultivation greenhouse.

[0061] (9) The control device according to the ninth embodiment is the control device according to (1) to (8), wherein when the humidity inside the cultivation house exceeds a predetermined threshold, the air conditioning control unit operates the exhaust fan and intake fan installed in the cultivation house. This makes it possible to reduce the humidity inside the cultivation house.

[0062] (10) The control device according to the tenth embodiment is the control device according to (1) to (9), further comprising: an opening / closing control value calculator that outputs the opening / closing direction and opening / closing speed of a curtain provided on the ceiling of the cultivation house based on the temperature difference between the cultivation shelf temperature and the target temperature; and a curtain control unit that calculates the opening / closing direction and opening / closing speed of the curtain based on the cultivation shelf temperature acquired by the acquisition unit, and controls the opening / closing operation of the curtain based on the calculated opening / closing direction and opening / closing speed. By controlling the degree of curtain opening according to the heat load in the cultivation house, the cultivation shelf temperature can be controlled to the target temperature more efficiently.

[0063] (11) The control device according to the 11th embodiment is the control device according to (1) to (10), wherein the control of the air conditioner by the air conditioning control unit and the control of the curtain by the curtain control unit are performed in parallel at a predetermined control cycle. By combining air conditioning control and curtain control, the temperature of the cultivation shelves can be controlled to the target temperature more efficiently.

[0064] (12) The cultivation greenhouse according to the twelfth embodiment comprises a building for housing cultivation shelves, a temperature sensor for measuring the temperature around the cultivation shelves, an air conditioner for air conditioning the building, and a control device as described in any of (1) to (11).

[0065] (13) The cultivation greenhouse according to the 13th embodiment comprises a building for housing cultivation shelves, a temperature sensor for measuring the temperature around the cultivation shelves, an air conditioner for air conditioning the building, a curtain installed on the ceiling of the building, and the control device described in (10) to (11).

[0066] (14) A control method according to the 14th embodiment includes the steps of: acquiring the cultivation shelf temperature, which is the temperature around the cultivation shelves in the cultivation greenhouse; an air conditioning intensity converter that converts the temperature difference between the cultivation shelf temperature and a predetermined target temperature into the air conditioning intensity of an air conditioner that provides air conditioning for the cultivation greenhouse; calculating the air conditioning intensity for controlling the cultivation shelf temperature to the target temperature based on the cultivation shelf temperature acquired in the acquisition step and the target temperature; calculating a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity; and commanding the air conditioner to the set temperature.

[0067] According to the control device, cultivation greenhouse, and control method described above, the temperature inside the cultivation greenhouse can be controlled to a desired target temperature.

[0068] 1...Building 10...Cultivation shelves 11...Cold air enclosure 12...Shelf section 13...Support section 20, 21...Duct 30, 31...Air conditioner 40...Curtain 41...Curtain 42...Fan 43...Ventilation fan 50...Control device 51...Acquisition unit 52...Air conditioning control unit 53...Curtain control unit 54...Memory unit 100...Cultivation house P...Plants C1, C2, C3, C6...Temperature sensors C4...Power monitor C5, C7...Humidity sensors

Claims

1. A control device comprising: an acquisition unit that acquires the temperature around the cultivation shelves in a cultivation greenhouse, which is the temperature of the cultivation shelves; an air conditioning intensity converter that converts the temperature difference between the cultivation shelves temperature and a predetermined target temperature into the air conditioning intensity of an air conditioner that provides air conditioning for the cultivation greenhouse; and an air conditioning control unit that calculates the air conditioning intensity for controlling the cultivation shelves temperature to the target temperature based on the cultivation shelves temperature acquired by the acquisition unit and the target temperature, calculates a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity, and commands the calculated set temperature to the air conditioner.

2. The control device according to claim 1, wherein the air conditioning intensity converter outputs, as the air conditioning intensity, the temperature difference between the temperature measured by the temperature sensor provided in the air conditioner and the set temperature to be commanded to the air conditioner.

3. The control device according to claim 1 or 2, further comprising: an operating mode determination unit that determines whether the air conditioner will perform cooling operation, heating operation, or fan operation based on the temperature difference between the cultivation shelf temperature and the target temperature, wherein the air conditioning control unit calculates the air conditioning intensity when the operating mode determination unit determines to perform cooling operation or heating operation.

4. The control device according to claim 1 or 2, further comprising: an operating mode determination unit that determines whether the air conditioner will perform cooling operation, heating operation, fan operation, or stop operation based on the temperature difference obtained by subtracting the target temperature from the cultivation shelf temperature, wherein the operating mode determination unit determines to stop the air conditioner when the temperature difference falls below a predetermined negative threshold when the air conditioner is performing cooling operation, and determines to stop the air conditioner when the temperature difference falls above a predetermined positive threshold when the air conditioner is performing heating operation.

5. The control device according to claim 1 or 2, wherein when the outside air temperature is below a predetermined temperature and / or the outside air humidity is below a predetermined humidity, the air conditioning control unit reduces the operating intensity of the air conditioner and operates a ventilation fan provided for ventilating the air inside the cultivation greenhouse with the outside air.

6. The control device according to claim 4, wherein when the humidity inside the cultivation greenhouse exceeds a predetermined threshold, the air conditioning control unit operates the air conditioner in fan mode instead of stopping the air conditioner.

7. The control device according to claim 1 or 2, wherein the air conditioning control unit controls two air conditioners, and when the humidity inside the cultivation greenhouse exceeds a predetermined threshold or the cooling load from the air conditioners falls below a predetermined value, the air conditioning control unit operates one of the air conditioners in heating mode and the remaining air conditioner in cooling mode to reduce the humidity inside the cultivation greenhouse.

8. The control device according to claim 1 or 2, wherein the air conditioning control unit controls two air conditioners, and when the humidity inside the cultivation greenhouse exceeds a predetermined threshold, the air conditioning control unit operates one of the air conditioners in cooling mode and the remaining air conditioner in fan mode to reduce the humidity inside the cultivation greenhouse.

9. When the humidity inside the cultivation greenhouse exceeds a predetermined threshold, the air conditioning control unit operates the exhaust fan and intake fan installed in the cultivation greenhouse, as described in claim 1 or 2.

10. The control device according to claim 1 or claim 2, further comprising: an opening / closing control value calculator that outputs the opening / closing direction and opening / closing speed of a curtain provided on the ceiling of the cultivation greenhouse based on the temperature difference between the cultivation shelf temperature and the target temperature; and a curtain control unit that calculates the opening / closing direction and opening / closing speed of the curtain based on the cultivation shelf temperature acquired by the acquisition unit, and controls the opening / closing operation of the curtain based on the calculated opening / closing direction and opening / closing speed.

11. The control device according to claim 10, wherein the control of the air conditioner by the air conditioning control unit and the control of the curtain by the curtain control unit are performed in parallel at a predetermined control cycle.

12. A cultivation greenhouse comprising: a building for housing cultivation shelves; a temperature sensor for measuring the temperature around the cultivation shelves; an air conditioner for providing air conditioning for the building; and the control device according to claim 1 or claim 2.

13. A cultivation house comprising: a building for housing cultivation shelves; a temperature sensor for measuring the temperature around the cultivation shelves; an air conditioner for providing air conditioning for the building; a curtain provided on the ceiling of the building; and the control device described in claim 10.

14. A control method comprising: a step of acquiring the cultivation shelf temperature, which is the temperature around the cultivation shelves in a cultivation greenhouse; an air conditioning intensity converter that converts the temperature difference between the cultivation shelf temperature and a predetermined target temperature into the air conditioning intensity of an air conditioner that provides air conditioning for the cultivation greenhouse; a step of calculating the air conditioning intensity for controlling the cultivation shelf temperature to the target temperature based on the cultivation shelf temperature acquired in the acquisition step and the target temperature; a step of calculating a set temperature to be commanded to the air conditioner from the calculated air conditioning intensity; and a step of commanding the air conditioner to the set temperature.

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